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Generated by the curl project managen man page generator. .\" .TH curl 1 "2026-05-15" "curl 8.20.0" "curl Manual" .SH NAME curl \- transfer a URL .SH SYNOPSIS \fBcurl [options / URLs]\fP .SH DESCRIPTION \fBcurl\fP is a tool for transferring data from or to a server using URLs. It supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, MQTTS, POP3, POP3S, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS. curl is powered by libcurl for all transfer\-related features. See \fIlibcurl(3)\fP for details. .SH URL The URL syntax is protocol\-dependent. You can find a detailed description in RFC 3986. If you provide a URL without a leading \fBprotocol://\fP scheme, curl guesses what protocol you want. It then defaults to HTTP but assumes others based on often\-used hostname prefixes. For example, for hostnames starting with "ftp." curl assumes you want FTP. You can specify any amount of URLs on the command line. They are fetched in a sequential manner in the specified order unless you use \fI\-\-parallel\fP. You can specify command line options and URLs mixed and in any order on the command line. curl attempts to reuse connections when doing multiple transfers, so that getting many files from the same server do not use multiple connects and setup handshakes. This improves speed. Connection reuse can only be done for URLs specified for a single command line invocation and cannot be performed between separate curl runs. Provide an IPv6 zone id in the URL with an escaped percentage sign. Like in .nf http://[fe80::3%25eth0]/ .fi Everything provided on the command line that is not a command line option or its argument, curl assumes is a URL and treats it as such. .SH GLOBBING You can specify multiple URLs or parts of URLs by writing lists within braces or ranges within brackets. We call this "globbing". Provide a list with three different names like this: .nf https://fun.example/{one,two,three}.jpg sftp://{one,two,three}.example/README .fi Do sequences of alphanumeric series by using [] as in: .nf ftp://ftp.example.com/file[1\-100].txt .fi With leading zeroes: .nf ftp://ftp.example.com/file[001\-100].txt .fi With letters through the alphabet: .nf ftp://ftp.example.com/file[a\-z].txt .fi Nested sequences are not supported, but you can use several ones next to each other: .nf https://example.com/archive[1996\-1999]/vol[1\-4]/part{a,b,c}.html .fi You can specify a step counter for the ranges to get every Nth number or letter: .nf https://example.com/file[1\-100:10].txt https://example.com/file[a\-z:2].txt .fi When using [] or {} sequences when invoked from a command line prompt, you probably have to put the full URL within double quotes to avoid the shell from interfering with it. This also goes for other characters treated special, like for example \(aq&\(aq, \(aq?\(aq and \(aq*\(aq. Switch off globbing with \fI\-\-globoff\fP. .SH VARIABLES curl supports command line variables (added in 8.3.0). Set variables with \fI\-\-variable\fP name=content or \fI\-\-variable\fP name@file (where "file" can be stdin if set to a single dash (\-)). Variable contents can be expanded in option parameters using "{{name}}" if the option name is prefixed with "\fI\-\-expand\-\fP". This gets the contents of the variable "name" inserted, or a blank if the name does not exist as a variable. Insert "{{" verbatim in the string by prefixing it with a backslash, like "\\{{". You can access and expand environment variables by importing them with \&"\fI\-\-variable\fP %name". This imports the variable called "name" but exits with an error if that environment variable is not already set. To provide a default value in case it is not already set, use "\fI\-\-variable\fP %name=content" or \&"\fI\-\-variable\fP %name@content". Example: get the USER environment variable and expand into the URL, fail if USER is not set: .nf -\-variable \(aq%USER\(aq -\-expand\-url = "https://example.com/api/{{USER}}/method" .fi When expanding variables, curl supports a set of functions that can make the variable contents more convenient to use. It can trim leading and trailing white space with "trim", output the contents as a JSON quoted string with \&"json", URL encode the string with "url", base64 encode it with "b64" and base64 decode it with "64dec". To apply functions to a variable expansion, add them colon separated to the right side of the variable. Variable content holding null bytes that are not encoded when expanded causes an error. Example: get the contents of a file called $HOME/.secret into a variable called "fix". Make sure that the content is trimmed and percent\-encoded when sent as POST data: .nf -\-variable %HOME -\-expand\-variable fix@{{HOME}}/.secret -\-expand\-data "{{fix:trim:url}}" https://example.com/ .fi Command line variables and expansions were added in 8.3.0. .SH OUTPUT If not told otherwise, curl writes the received data to stdout. It can be instructed to instead save that data into a local file, using the \fI\-\-output\fP or \fI\-\-remote\-name\fP options. If curl is given multiple URLs to transfer on the command line, it similarly needs multiple options for where to save them. curl does not parse or otherwise "understand" the content it gets or writes as output. It does no encoding or decoding, unless explicitly asked to with dedicated command line options. .SH PROTOCOLS curl supports numerous protocols, or put in URL terms: schemes. Your particular build may not support them all. .IP DICT Lets you lookup words using online dictionaries. .IP FILE Read or write local files. curl does not support accessing file:// URL remotely, but when running on Microsoft Windows using the native UNC approach works. Only absolute paths. .IP FTP(S) curl supports the File Transfer Protocol with a lot of tweaks and levers. With or without using TLS. .IP GOPHER(S) Retrieve files. .IP HTTP(S) curl supports HTTP with numerous options and variations. It can speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build options and the correct command line options. .IP IMAP(S) Using the mail reading protocol, curl can download emails for you. With or without using TLS. .IP LDAP(S) curl can do directory lookups for you, with or without TLS. .IP MQTT curl supports MQTT version 3. Downloading over MQTT equals subscribing to a topic while uploading/posting equals publishing on a topic. MQTT over TLS is not supported (yet). .IP POP3(S) Downloading from a pop3 server means getting an email. With or without using TLS. .IP RTSP curl supports RTSP 1.0 downloads. .IP SCP curl supports SSH version 2 scp transfers. .IP SFTP curl supports SFTP (draft 5) done over SSH version 2. .IP SMB(S) curl supports SMB version 1 for upload and download. .IP SMTP(S) Uploading contents to an SMTP server means sending an email. With or without TLS. .IP TELNET Fetching a telnet URL starts an interactive session where it sends what it reads on stdin and outputs what the server sends it. .IP TFTP curl can do TFTP downloads and uploads. .IP WS(S) WebSocket done over HTTP/1. WSS implies that it works over HTTPS. .SH PROGRESS METER curl normally displays a progress meter during operations, indicating the amount of transferred data, transfer speeds and estimated time left, etc. The progress meter displays the transfer rate in bytes per second. The used suffixes ("k" for kilo, "M" for mega, "G" for giga, "T" for tera, "P" for peta and "E" for exa) are 1024 based. For example 1k is 1024 bytes. 1M is 1048576 bytes. Strictly speaking this makes the units kibibyte and mebibyte etc. curl displays this data to the terminal by default, so if you invoke curl to do an operation and it is about to write data to the terminal, it \fIdisables\fP the progress meter as otherwise it would mess up the output mixing progress meter and response data. If you want a progress meter for HTTP POST or PUT requests, you need to redirect the response output to a file, using shell redirect (>), \fI\-\-output\fP or similar. This does not apply to FTP upload as that operation does not spit out any response data to the terminal. If you prefer a progress bar instead of the regular meter, \fI\-\-progress\-bar\fP is your friend. You can also disable the progress meter completely with the \fI\-\-silent\fP option. .SH VERSION This man page describes curl 8.20.0. If you use a later version, chances are this man page does not fully document it. If you use an earlier version, this document tries to include version information about which specific version that introduced changes. You can always learn which the latest curl version is by running .nf curl https://curl.se/info .fi The online version of this man page is always showing the latest incarnation: https://curl.se/docs/manpage.html .SH OPTIONS Options start with one or two dashes. Many of the options require an additional value next to them. If provided text does not start with a dash, it is presumed to be and treated as a URL. The short "single\-dash" form of the options, \-d for example, may be used with or without a space between it and its value, although a space is a recommended separator. The long double\-dash form, \fI\-\-data\fP for example, requires a space between it and its value. Short version options that do not need any additional values can be used immediately next to each other, like for example you can specify all the options \fI\-O\fP, \fI\-L\fP and \fI\-v\fP at once as \fI\-OLv\fP. In general, all boolean options are enabled with \--\fBoption\fP and yet again disabled with \--\fBno\-\fPoption. That is, you use the same option name but prefix it with "no\-". In this list we mostly show the \--\fBoption\fP version of them. When \fI\-\-next\fP is used, it resets the parser state and you start again with a clean option state, except for the options that are global. Global options retain their values and meaning even after \fI\-\-next\fP. If the long option name ends with an equals sign ("="), the argument is the text following on its right side. (Added in 8.16.0) The first argument that is exactly two dashes ("\--"), marks the end of options; any argument after the end of options is interpreted as a URL argument even if it starts with a dash. curl does little to no verification of the contents of command line arguments. Passing in "creative octets" like newlines might trigger unexpected results. The following options are global: \fI\-\-fail\-early\fP, \fI\-\-libcurl\fP, \fI\-\-parallel\-immediate\fP, \fI\-\-parallel\-max\-host\fP, \fI\-\-parallel\-max\fP, \fI\-\-parallel\fP, \fI\-\-progress\-bar\fP, \fI\-\-rate\fP, \fI\-\-show\-error\fP, \fI\-\-stderr\fP, \fI\-\-styled\-output\fP, \fI\-\-trace\-ascii\fP, \fI\-\-trace\-config\fP, \fI\-\-trace\-ids\fP, \fI\-\-trace\-time\fP, \fI\-\-trace\fP and \fI\-\-verbose\fP. .SH ALL OPTIONS .IP "\-\-abstract\-unix\-socket <path>" (HTTP) Connect to the server through an abstract Unix domain socket, instead of using the network. Note: netstat shows the path of an abstract socket prefixed with \&"@", however the <path> argument should not have this leading character. If \fI\-\-abstract\-unix\-socket\fP is provided several times, the last set value is used. Example: .nf curl --abstract-unix-socket socketpath https://example.com .fi See also \fI\-\-unix\-socket\fP. .IP "\-\-alt\-svc <filename>" (HTTPS) Enable the alt\-svc parser. If the filename points to an existing alt\-svc cache file, that gets used. After a completed transfer, the cache is saved to the filename again if it has been modified. Specify a "" filename (zero length) to avoid loading/saving and make curl handle the cache in memory. You may want to restrict your umask to prevent other users on the same system to access the created file. If this option is used several times, curl loads contents from all the files but the last one is used for saving. \fI\-\-alt\-svc\fP can be used several times in a command line Example: .nf curl --alt-svc svc.txt https://example.com .fi See also \fI\-\-resolve\fP and \fI\-\-connect\-to\fP. .IP "\-\-anyauth" (HTTP) Figure out authentication method automatically, and use the most secure one the remote site claims to support. This is done by first doing a request and checking the response\-headers, thus possibly inducing an extra network round\-trip. This option is used instead of setting a specific authentication method, which you can do with \fI\-\-basic\fP, \fI\-\-digest\fP, \fI\-\-ntlm\fP, and \fI\-\-negotiate\fP. Using \fI\-\-anyauth\fP is not recommended if you do uploads from stdin, since it may require data to be sent twice and then the client must be able to rewind. If the need should arise when uploading from stdin, the upload operation fails. Used together with \fI\-\-user\fP. Example: .nf curl --anyauth --user me:pwd https://example.com .fi See also \fI\-\-proxy\-anyauth\fP, \fI\-\-basic\fP and \fI\-\-digest\fP. .IP "\-a, \-\-append" (FTP SFTP) When used in an upload, this option makes curl append to the target file instead of overwriting it. If the remote file does not exist, it is created. Note that this flag is ignored by some SFTP servers (including OpenSSH). Providing \fI\-\-append\fP multiple times has no extra effect. Disable it again with \-\-no-append. Example: .nf curl --upload-file local --append ftp://example.com/ .fi See also \fI\-\-range\fP and \fI\-\-continue\-at\fP. .IP "\-\-aws\-sigv4 <provider1[:prvdr2[:reg[:srv]]]>" (HTTP) Use AWS V4 signature authentication in the transfer. The provider argument is a string that is used by the algorithm when creating outgoing authentication headers. The region argument is a string that points to a geographic area of a resources collection (region\-code) when the region name is omitted from the endpoint. The service argument is a string that points to a function provided by a cloud (service\-code) when the service name is omitted from the endpoint. If \fI\-\-aws\-sigv4\fP is provided several times, the last set value is used. Example: .nf curl --aws-sigv4 "aws:amz:us-east-2:es" --user "key:secret" https://example.com .fi Added in 7.75.0. See also \fI\-\-basic\fP and \fI\-\-user\fP. .IP "\-\-basic" (HTTP) Use HTTP Basic authentication with the remote host. This method is the default and this option is usually pointless, unless you use it to override a previously set option that sets a different authentication method (such as \fI\-\-ntlm\fP, \fI\-\-digest\fP, or \fI\-\-negotiate\fP). Used together with \fI\-\-user\fP. Providing \fI\-\-basic\fP multiple times has no extra effect. Disable it again with \-\-no-basic. Example: .nf curl -u name:password --basic https://example.com .fi See also \fI\-\-proxy\-basic\fP. .IP "\-\-ca\-native" (TLS) Use the operating system\(aqs native CA store for certificate verification. This option is independent of other CA certificate locations set at run time or build time. Those locations are searched in addition to the native CA store. This option works with OpenSSL and its forks (LibreSSL, BoringSSL, etc) on Windows (Added in 7.71.0) and on Apple OS when libcurl is built with Apple SecTrust enabled. (Added in 8.17.0) This option works with wolfSSL on Windows, Linux (Debian, Ubuntu, Gentoo, Fedora, RHEL), macOS, Android and iOS. (Added in 8.3.0) This option works with GnuTLS (Added in 8.5.0) and also uses Apple SecTrust when libcurl is built with it. (Added in 8.17.0) This option works with Rustls on Windows, macOS, Android and iOS. On Linux it is equivalent to using the Mozilla CA certificate bundle. When used with Rustls _only_ the native CA store is consulted, not other locations set at run time or build time. (Added in 8.13.0) This option currently has no effect for Schannel. This is the native TLS library from Microsoft, that by default uses the native CA store for verification unless overridden by a CA certificate location setting. Providing \fI\-\-ca\-native\fP multiple times has no extra effect. Disable it again with \-\-no-ca-native. Example: .nf curl --ca-native https://example.com .fi Added in 8.2.0. See also \fI\-\-cacert\fP, \fI\-\-capath\fP, \fI\-\-dump\-ca\-embed\fP, \fI\-\-insecure\fP and \fI\-\-proxy\-ca\-native\fP. .IP "\-\-cacert <file>" (TLS) Use the specified certificate file to verify the peer. The file may contain multiple CA certificates. The certificate(s) must be in PEM format. Normally curl is built to use a default file for this, so this option is typically used to alter that default file. curl recognizes the environment variable named \(aqCURL_CA_BUNDLE\(aq if it is set and the TLS backend is not Schannel, and uses the given path as a path to a CA cert bundle. This option overrides that variable. (Windows) curl automatically looks for a CA certs file named \(aqcurl\-ca\-bundle.crt\(aq, either in the same directory as curl.exe, or in the Current Working Directory, or in any folder along your PATH. curl 8.11.0 added a build\-time option to disable this search behavior, and another option to restrict search to the application\(aqs directory. (Schannel) This option is supported for Schannel in Windows 7 or later (added in 7.60.0). This option is supported for backward compatibility with other SSL engines; instead it is recommended to use Windows\(aq store of root certificates (the default for Schannel). If \fI\-\-cacert\fP is provided several times, the last set value is used. Example: .nf curl --cacert CA-file.txt https://example.com .fi See also \fI\-\-capath\fP, \fI\-\-dump\-ca\-embed\fP and \fI\-\-insecure\fP. .IP "\-\-capath <dir>" (TLS) Use the specified certificate directory to verify the peer. If curl is built against OpenSSL, multiple paths can be provided by separating them with the appropriate platform\-specific separator (e.g. "path1:path2:path3" on Unix\-style platforms for "path1;path2;path3" on Windows). The certificates must be in PEM format, and if curl is built against OpenSSL, the directory must have been processed using the c_rehash utility supplied with OpenSSL. Using \fI\-\-capath\fP can allow OpenSSL\-powered curl to make SSL\-connections much more efficiently than using \fI\-\-cacert\fP if the \fI\-\-cacert\fP file contains many CA certificates. If this option is set, the default capath value is ignored. If \fI\-\-capath\fP is provided several times, the last set value is used. Example: .nf curl --capath /local/directory https://example.com .fi See also \fI\-\-cacert\fP, \fI\-\-dump\-ca\-embed\fP and \fI\-\-insecure\fP. .IP "\-E, \-\-cert <certificate[:password]>" (TLS) Use the specified client certificate file when getting a file with HTTPS, FTPS or another SSL\-based protocol. The certificate must be PEM format. If the optional password is not specified, it is queried for on the terminal. Note that this option assumes a certificate file that is the private key and the client certificate concatenated. See \fI\-\-cert\fP and \fI\-\-key\fP to specify them independently. In the <certificate> portion of the argument, you must escape the character \&":" as "\\:" so that it is not recognized as the password delimiter. Similarly, you must escape the double quote character as \\" so that it is not recognized as an escape character. If curl is built against OpenSSL, and the engine pkcs11 or pkcs11 provider is available, then a PKCS#11 URI (RFC 7512) can be used to specify a certificate located in a PKCS#11 device. A string beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the \fI\-\-engine\fP option is set as "pkcs11" if none was provided and the \fI\-\-cert\-type\fP option is set as "ENG" or "PROV" if none was provided (depending on OpenSSL version). If curl is built against GnuTLS, a PKCS#11 URI can be used to specify a certificate located in a PKCS#11 device. A string beginning with "pkcs11:" is interpreted as a PKCS#11 URI. (Schannel) Client certificates must be specified by a path expression to a certificate store. (Loading \fIPFX\fP is not supported; you can import it to a store first). You can use "<store location>\\<store name>\\<thumbprint>" to refer to a certificate in the system certificates store, for example, \fI"CurrentUser\\MY\\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a"\fP. Thumbprint is usually a SHA\-1 hex string which you can see in certificate details. Following store locations are supported: \fICurrentUser\fP, \fILocalMachine\fP, \fICurrentService\fP, \fIServices\fP, \fICurrentUserGroupPolicy\fP, \fILocalMachineGroupPolicy\fP and \fILocalMachineEnterprise\fP. If \fI\-\-cert\fP is provided several times, the last set value is used. Example: .nf curl --cert certfile --key keyfile https://example.com .fi See also \fI\-\-cert\-type\fP, \fI\-\-key\fP and \fI\-\-key\-type\fP. .IP "\-\-cert\-status" (TLS) Verify the status of the server certificate by using the Certificate Status Request (aka. OCSP stapling) TLS extension. If this option is enabled and the server sends an invalid (e.g. expired) response, if the response suggests that the server certificate has been revoked, or no response at all is received, the verification fails. This support is currently only implemented in the OpenSSL and GnuTLS backends. Providing \fI\-\-cert\-status\fP multiple times has no extra effect. Disable it again with \-\-no-cert-status. Example: .nf curl --cert-status https://example.com .fi See also \fI\-\-pinnedpubkey\fP. .IP "\-\-cert\-type <type>" (TLS) Set type of the provided client certificate. PEM, DER, ENG, PROV and P12 are recognized types. The default type depends on the TLS backend and is usually PEM. For Schannel it is P12. If \fI\-\-cert\fP is a pkcs11: URI then ENG or PROV is the default type (depending on OpenSSL version). If \fI\-\-cert\-type\fP is provided several times, the last set value is used. Example: .nf curl --cert-type PEM --cert file https://example.com .fi See also \fI\-\-cert\fP, \fI\-\-key\fP and \fI\-\-key\-type\fP. .IP "\-\-ciphers <list>" (TLS) Specify which cipher suites to use in the connection if it negotiates TLS 1.2 (1.1, 1.0). The list of ciphers suites must specify valid ciphers. Read up on cipher suite details on this URL: https://curl.se/docs/ssl\-ciphers.html If \fI\-\-ciphers\fP is provided several times, the last set value is used. Example: .nf curl --ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256 https://example.com .fi See also \fI\-\-tls13\-ciphers\fP, \fI\-\-proxy\-ciphers\fP and \fI\-\-curves\fP. .IP "\-\-compressed" (HTTP) Request a compressed response using one of the algorithms curl supports, and automatically decompress the content. Response headers are not modified when saved, so if they are "interpreted" separately again at a later point they might appear to be saying that the content is (still) compressed; while in fact it has already been decompressed. If this option is used and the server sends an unsupported encoding, curl reports an error. This is a request, not an order; the server may or may not deliver data compressed. \fBWARNING\fP: when decompressing data, even tiny transfers might be expanded and generate a huge amount of bytes. You might want to limit using this option to only known and trusted sites using secure protocols, perhaps in combination with \fI\-\-max\-filesize\fP. Providing \fI\-\-compressed\fP multiple times has no extra effect. Disable it again with \-\-no-compressed. Example: .nf curl --compressed https://example.com .fi See also \fI\-\-compressed\-ssh\fP. .IP "\-\-compressed\-ssh" (SCP SFTP) Enable SSH compression. This is a request, not an order; the server may or may not do it. This allows the data to be sent compressed over the wire, and automatically decompressed in the receiving end, to save bandwidth. Providing \fI\-\-compressed\-ssh\fP multiple times has no extra effect. Disable it again with \-\-no-compressed-ssh. Example: .nf curl --compressed-ssh sftp://example.com/ .fi See also \fI\-\-compressed\fP. .IP "\-K, \-\-config <file>" Specify a text file to read curl arguments from. The command line arguments found in the text file are used as if they were provided on the command line. Options and their parameters must be specified on the same line in the file, separated by whitespace, colon, or the equals sign. Long option names can optionally be given in the config file without the initial double dashes and if so, the colon or equals characters can be used as separators. If the option is specified with one or two dashes, there can be no colon or equals character between the option and its parameter. If the parameter contains whitespace or starts with a colon (:) or equals sign (=), it must be specified enclosed within double quotes ("like this"). Within double quotes the following escape sequences are available: \\\\, \\", \\t, \\n, \\r and \\v. A backslash preceding any other letter is ignored. If the first non\-blank column of a config line is a \(aq#\(aq character, that line is treated as a comment. Only write one option per physical line in the config file. A single line is required to be no more than 10 megabytes (since 8.2.0). Specify the filename to \fI\-\-config\fP as minus "\-" to make curl read the file from stdin. Note that to be able to specify a URL in the config file, you need to specify it using the \fI\-\-url\fP option, and not by writing the URL on its own line. It could look similar to this: .nf url = "https://curl.se/docs/" # \--\- Example file \--\- # this is a comment url = "example.com" output = "curlhere.html" user\-agent = "superagent/1.0" # and fetch another URL too url = "example.com/docs/manpage.html" -O referer = "http://nowhereatall.example.com/" # \--\- End of example file \--\- .fi When curl is invoked, it (unless \fI\-\-disable\fP is used) checks for a default config file and uses it if found, even when \fI\-\-config\fP is used. The default config file is checked for in the following places in this order: 1) \fB"$CURL_HOME/.curlrc"\fP 2) \fB"$XDG_CONFIG_HOME/curlrc"\fP (Added in 7.73.0) 3) \fB"$HOME/.curlrc"\fP 4) Windows: \fB"%USERPROFILE%\\.curlrc"\fP 5) Windows: \fB"%APPDATA%\\.curlrc"\fP 6) Windows: \fB"%USERPROFILE%\\Application Data\\.curlrc"\fP 7) Non\-Windows: use getpwuid to find the home directory 8) On Windows, if it finds no \fI.curlrc\fP file in the sequence described above, it checks for one in the same directory the curl executable is placed. On Windows two filenames are checked per location: \fI.curlrc\fP and \fI_curlrc\fP, preferring the former. Older versions on Windows checked for \fI_curlrc\fP only. \fI\-\-config\fP can be used several times in a command line Example: .nf curl --config file.txt https://example.com .fi See also \fI\-\-disable\fP. .IP "\-\-connect\-timeout <seconds>" Maximum time in seconds that you allow curl\(aqs connection to take. This only limits the connection phase, so if curl connects within the given period it continues \- if not it exits. This option accepts decimal values. The decimal value needs to be provided using a dot (.) as decimal separator \- not the local version even if it might be using another separator. The connection phase is considered complete when the DNS lookup and requested TCP, TLS or QUIC handshakes are done. If \fI\-\-connect\-timeout\fP is provided several times, the last set value is used. Examples: .nf curl --connect-timeout 20 https://example.com curl --connect-timeout 3.14 https://example.com .fi See also \fI\-\-max\-time\fP. .IP "\-\-connect\-to <HOST1:PORT1:HOST2:PORT2>" For a request intended for the "HOST1:PORT1" pair, connect to "HOST2:PORT2" instead. This option is only used to establish the network connection. It does NOT affect the hostname/port number that is used for TLS/SSL (e.g. SNI, certificate verification) or for the application protocols. \&"HOST1" and "PORT1" may be empty strings, meaning any host or any port number. \&"HOST2" and "PORT2" may also be empty strings, meaning use the request\(aqs original hostname and port number. A hostname specified to this option is compared as a string, so it needs to match the name used in the request URL. It can be either numerical such as \&"127.0.0.1" or the full hostname such as "example.org". Example: redirect connects from the example.com hostname to 127.0.0.1 independently of port number: .nf curl \--connect\-to example.com::127.0.0.1: https://example.com/ .fi Example: redirect connects from all hostnames to 127.0.0.1 independently of port number: .nf curl \--connect\-to ::127.0.0.1: http://example.com/ .fi \fI\-\-connect\-to\fP can be used several times in a command line Example: .nf curl --connect-to example.com:443:example.net:8443 https://example.com .fi See also \fI\-\-resolve\fP and \fI\-\-header\fP. .IP "\-C, \-\-continue\-at <offset>" Resume a previous transfer from the given byte offset. The given offset is the exact number of bytes that are skipped, counting from the beginning of the source file before it is transferred to the destination. If used with uploads, the FTP server command SIZE is not used by curl. Use "\-C \-" to instruct curl to automatically find out where/how to resume the transfer. It then uses the given output/input files to figure that out. When using this option for HTTP uploads using POST or PUT, functionality is not guaranteed. The HTTP protocol has no standard interoperable resume upload and curl uses a set of headers for this purpose that once proved working for some servers and have been left for those who find that useful. This command line option is mutually exclusive with \fI\-\-range\fP: you can only use one of them for a single transfer. The \fI\-\-no\-clobber\fP and \fI\-\-remove\-on\-error\fP options cannot be used together with \fI\-\-continue\-at\fP. If \fI\-\-continue\-at\fP is provided several times, the last set value is used. Examples: .nf curl -C - https://example.com curl -C 400 https://example.com .fi See also \fI\-\-range\fP. .IP "\-b, \-\-cookie <data|filename>" (HTTP) This option has two slightly separate cookie sending functions. Either: pass the exact data to send to the HTTP server in the Cookie header. It is supposedly data previously received from the server in a "Set\-Cookie:" line. The data should be in the format "NAME1=VALUE1; NAME2=VALUE2". When given a set of specific cookies, curl populates its cookie header with this content explicitly in all outgoing request(s). If multiple requests are done due to authentication, followed redirects or similar, they all get this cookie header passed on. Or: If no "=" symbol is used in the argument, it is instead treated as a filename to read previously stored cookie from. This option also activates the cookie engine which makes curl record incoming cookies, which may be handy if you are using this in combination with the \fI\-\-location\fP option or do multiple URL transfers on the same invoke. If the filename is a single minus ("\-"), curl reads the contents from stdin. If the filename is an empty string ("") and is the only cookie input, curl activates the cookie engine without any cookies. The file format of the file to read cookies from should be plain HTTP headers (Set\-Cookie style) or the Netscape/Mozilla cookie file format. The file specified with \fI\-\-cookie\fP is only used as input. No cookies are written to that file. To store cookies, use the \fI\-\-cookie\-jar\fP option. If you use the Set\-Cookie file format and do not specify a domain then the cookie is not sent since the domain never matches. To address this, set a domain in Set\-Cookie line (doing that includes subdomains) or preferably: use the Netscape format. Users often want to both read cookies from a file and write updated cookies back to a file, so using both \fI\-\-cookie\fP and \fI\-\-cookie\-jar\fP in the same command line is common. curl ignores filenames specified with \fI\-\-cookie\fP which do not exist or point to a directory. If curl is built with PSL (\fBPublic Suffix List\fP) support, it detects and discards cookies that are specified for such suffix domains that should not be allowed to have cookies. If curl is \fInot\fP built with PSL support, it has no ability to stop super cookies. \fI\-\-cookie\fP can be used several times in a command line Examples: .nf curl -b "" https://example.com curl -b cookiefile https://example.com curl -b cookiefile -c cookiefile https://example.com curl -b name=Jane https://example.com .fi See also \fI\-\-cookie\-jar\fP and \fI\-\-junk\-session\-cookies\fP. .IP "\-c, \-\-cookie\-jar <filename>" (HTTP) Specify to which file you want curl to write all cookies after a completed operation. curl writes all cookies from its in\-memory cookie storage to the given file at the end of operations. Even if no cookies are known, a file is created so that it removes any formerly existing cookies from the file. The file uses the Netscape cookie file format. If you set the filename to a single minus, "\-", the cookies are written to stdout. The file specified with \fI\-\-cookie\-jar\fP is only used for output. No cookies are read from the file. To read cookies, use the \fI\-\-cookie\fP option. Both options can specify the same file. This command line option activates the cookie engine that makes curl record and use cookies. The \fI\-\-cookie\fP option also activates it. If the cookie jar cannot be created or written to, the whole curl operation does not fail or even report an error clearly. Using \fI\-\-verbose\fP gets a warning displayed, but that is the only visible feedback you get about this possibly lethal situation. You may want to restrict your umask to prevent other users on the same system to access the created file. If \fI\-\-cookie\-jar\fP is provided several times, the last set value is used. Examples: .nf curl -c store-here.txt https://example.com curl -c store-here.txt -b read-these https://example.com .fi See also \fI\-\-cookie\fP and \fI\-\-junk\-session\-cookies\fP. .IP "\-\-create\-dirs" When used in conjunction with the \fI\-\-output\fP option, curl creates the necessary local directory hierarchy as needed. This option creates the directories mentioned with the \fI\-\-output\fP option combined with the path possibly set with \fI\-\-output\-dir\fP. If the combined output filename uses no directory, or if the directories it mentions already exist, no directories are created. Created directories are made with mode 0750 on Unix\-style file systems. To create remote directories when using FTP or SFTP, try \fI\-\-ftp\-create\-dirs\fP. Providing \fI\-\-create\-dirs\fP multiple times has no extra effect. Disable it again with \-\-no-create-dirs. Example: .nf curl --create-dirs --output local/dir/file https://example.com .fi See also \fI\-\-ftp\-create\-dirs\fP and \fI\-\-output\-dir\fP. .IP "\-\-create\-file\-mode <mode>" (SFTP SCP FILE) When curl is used to create files remotely using one of the supported protocols, this option allows the user to set which \(aqmode\(aq to set on the file at creation time, instead of the default 0644. This option takes an octal number as argument. If \fI\-\-create\-file\-mode\fP is provided several times, the last set value is used. Example: .nf curl --create-file-mode 0777 -T localfile sftp://example.com/new .fi Added in 7.75.0. See also \fI\-\-ftp\-create\-dirs\fP. .IP "\-\-crlf" (FTP SMTP) Convert line feeds to carriage return plus line feeds in upload. Useful for \fBMVS (OS/390)\fP. Providing \fI\-\-crlf\fP multiple times has no extra effect. Disable it again with \-\-no-crlf. Example: .nf curl --crlf -T file ftp://example.com/ .fi See also \fI\-\-use\-ascii\fP. .IP "\-\-crlfile <file>" (TLS) Provide a file using PEM format with a Certificate Revocation List that may specify peer certificates that are to be considered revoked. If \fI\-\-crlfile\fP is provided several times, the last set value is used. Example: .nf curl --crlfile rejects.txt https://example.com .fi See also \fI\-\-cacert\fP and \fI\-\-capath\fP. .IP "\-\-curves <list>" (TLS) Set specific curves to use during SSL session establishment according to RFC 8422, 5.1. Multiple algorithms can be provided by separating them with ":" (e.g. "X25519:P\-521"). The parameter is available identically in the OpenSSL \&"s_client" and "s_server" utilities. \fI\-\-curves\fP allows a OpenSSL powered curl to make SSL\-connections with exactly the (EC) curve requested by the client, avoiding nontransparent client/server negotiations. If this option is set, the default curves list built into OpenSSL are ignored. If \fI\-\-curves\fP is provided several times, the last set value is used. Example: .nf curl --curves X25519 https://example.com .fi Added in 7.73.0. See also \fI\-\-ciphers\fP. .IP "\-d, \-\-data <data>" (HTTP MQTT) Send the specified data in a POST request to the HTTP server, in the same way that a browser does when a user has filled in an HTML form and presses the submit button. This option makes curl pass the data to the server using the content\-type application/x\-www\-form\-urlencoded. Compared to \fI\-\-form\fP. \fI\-\-data\-raw\fP is almost the same but does not have a special interpretation of the @ character. To post data purely binary, you should instead use the \fI\-\-data\-binary\fP option. To URL\-encode the value of a form field you may use \fI\-\-data\-urlencode\fP. If any of these options is used more than once on the same command line, the data pieces specified are merged with a separating &\-symbol. Thus, using \(aq\-d name=daniel \-d skill=lousy\(aq would generate a post chunk that looks like \(aqname=daniel&skill=lousy\(aq. If you start the data with the letter @, the rest should be a filename to read the data from, or \- if you want curl to read the data from stdin. Posting data from a file named \(aqfoobar\(aq would thus be done with \fI\-\-data\fP @foobar. When \fI\-\-data\fP is told to read from a file like that, carriage returns, newlines and null bytes are stripped out. If you do not want the @ character to have a special interpretation use \fI\-\-data\-raw\fP instead. The data for this option is passed on to the server exactly as provided on the command line. curl does not convert, change or improve it. It is up to the user to provide the data in the correct form. \fI\-\-data\fP can be used several times in a command line Examples: .nf curl -d "name=curl" https://example.com curl -d "name=curl" -d "tool=cmdline" https://example.com curl -d @filename https://example.com .fi This option is mutually exclusive with \fI\-\-form\fP, \fI\-\-head\fP and \fI\-\-upload\-file\fP. See also \fI\-\-data\-binary\fP, \fI\-\-data\-urlencode\fP and \fI\-\-data\-raw\fP. .IP "\-\-data\-ascii <data>" (HTTP) This option is an alias for \fI\-\-data\fP. \fI\-\-data\-ascii\fP can be used several times in a command line Example: .nf curl --data-ascii @file https://example.com .fi See also \fI\-\-data\-binary\fP, \fI\-\-data\-raw\fP and \fI\-\-data\-urlencode\fP. .IP "\-\-data\-binary <data>" (HTTP) Post data exactly as specified with no extra processing whatsoever. If you start the data with the letter @, the rest should be a filename. \&"@\-" makes curl read the data from stdin. Data is posted in a similar manner as \fI\-\-data\fP does, except that newlines and carriage returns are preserved and conversions are never done. Like \fI\-\-data\fP the default content\-type sent to the server is application/x\-www\-form\-urlencoded. If you want the data to be treated as arbitrary binary data by the server then set the content\-type to octet\-stream: -H "Content\-Type: application/octet\-stream". If this option is used several times, the ones following the first append data as described in \fI\-\-data\fP. \fI\-\-data\-binary\fP can be used several times in a command line Example: .nf curl --data-binary @filename https://example.com .fi See also \fI\-\-data\-ascii\fP. .IP "\-\-data\-raw <data>" (HTTP) Post data similarly to \fI\-\-data\fP but without the special interpretation of the @ character. \fI\-\-data\-raw\fP can be used several times in a command line Examples: .nf curl --data-raw "hello" https://example.com curl --data-raw "@at@at@" https://example.com .fi See also \fI\-\-data\fP. .IP "\-\-data\-urlencode <data>" (HTTP) Post data, similar to the other \fI\-\-data\fP options with the exception that this performs URL\-encoding. To be CGI\-compliant, the <data> part should begin with a \fIname\fP followed by a separator and a content specification. The <data> part can be passed to curl using one of the following syntaxes: .RS .IP content URL\-encode the content and pass that on. Be careful so that the content does not contain any "=" or "@" symbols, as that makes the syntax match one of the other cases below. .IP =content URL\-encode the content and pass that on. The preceding "=" symbol is not included in the data. .IP name=content URL\-encode the content part and pass that on. Note that the name part is expected to be URL\-encoded already. .IP @filename load data from the given file (including any newlines), URL\-encode that data and pass it on in the POST. Using "@\-" makes curl read the data from stdin. .IP name@filename load data from the given file (including any newlines), URL\-encode that data and pass it on in the POST. The name part gets an equal sign appended, resulting in \fIname=urlencoded\-file\-content\fP. Note that the name is expected to be URL\-encoded already. .RE .IP \fI\-\-data\-urlencode\fP can be used several times in a command line Examples: .nf curl --data-urlencode name=val https://example.com curl --data-urlencode =encodethis https://example.com curl --data-urlencode name@file https://example.com curl --data-urlencode @fileonly https://example.com .fi See also \fI\-\-data\fP and \fI\-\-data\-raw\fP. .IP "\-\-delegation <LEVEL>" (GSS/kerberos) Set LEVEL what curl is allowed to delegate when it comes to user credentials. .RS .IP none Do not allow any delegation. .IP policy Delegates if and only if the OK\-AS\-DELEGATE flag is set in the Kerberos service ticket, which is a matter of realm policy. .IP always Unconditionally allow the server to delegate. .RE .IP If \fI\-\-delegation\fP is provided several times, the last set value is used. Example: .nf curl --delegation "none" https://example.com .fi See also \fI\-\-insecure\fP and \fI\-\-ssl\fP. .IP "\-\-digest" (HTTP) Enable HTTP Digest authentication. This authentication scheme avoids sending the password over the wire in clear text. Use this in combination with the normal \fI\-\-user\fP option to set username and password. Providing \fI\-\-digest\fP multiple times has no extra effect. Disable it again with \-\-no-digest. Example: .nf curl -u name:password --digest https://example.com .fi See also \fI\-\-user\fP, \fI\-\-proxy\-digest\fP and \fI\-\-anyauth\fP. .IP "\-q, \-\-disable" If used as the \fBfirst\fP parameter on the command line, the \fIcurlrc\fP config file is not read or used. See the \fI\-\-config\fP for details on the default config file search path. Providing \fI\-\-disable\fP multiple times has no extra effect. Disable it again with \-\-no-disable. Example: .nf curl -q https://example.com .fi See also \fI\-\-config\fP. .IP "\-\-disable\-eprt" (FTP) Disable the use of the EPRT and LPRT commands when doing active FTP transfers. curl normally first attempts to use EPRT before using PORT, but with this option, it uses PORT right away. EPRT is an extension to the original FTP protocol, and does not work on all servers, but enables more functionality in a better way than the traditional PORT command. \fI\-\-eprt\fP can be used to explicitly enable EPRT again and \fI\-\-no\-eprt\fP is an alias for \fI\-\-disable\-eprt\fP. If the server is accessed using IPv6, this option has no effect as EPRT is necessary then. Disabling EPRT only changes the active behavior. If you want to switch to passive mode you need to not use \fI\-\-ftp\-port\fP or force it with \fI\-\-ftp\-pasv\fP. Providing \fI\-\-disable\-eprt\fP multiple times has no extra effect. Disable it again with \-\-no-disable-eprt. Example: .nf curl --disable-eprt ftp://example.com/ .fi See also \fI\-\-disable\-epsv\fP and \fI\-\-ftp\-port\fP. .IP "\-\-disable\-epsv" (FTP) Disable the use of the EPSV command when doing passive FTP transfers. curl normally first attempts to use EPSV before PASV, but with this option, it does not try EPSV. \fI\-\-epsv\fP can be used to explicitly enable EPSV again and \fI\-\-no\-epsv\fP is an alias for \fI\-\-disable\-epsv\fP. If the server is an IPv6 host, this option has no effect as EPSV is necessary then. Disabling EPSV only changes the passive behavior. If you want to switch to active mode you need to use \fI\-\-ftp\-port\fP. Providing \fI\-\-disable\-epsv\fP multiple times has no extra effect. Disable it again with \-\-no-disable-epsv. Example: .nf curl --disable-epsv ftp://example.com/ .fi See also \fI\-\-disable\-eprt\fP and \fI\-\-ftp\-port\fP. .IP "\-\-disallow\-username\-in\-url" Exit with error if passed a URL containing a username. Probably most useful when the URL is being provided at runtime or similar. Accepting and using credentials in a URL is normally considered a security hazard as they are easily leaked that way. Providing \fI\-\-disallow\-username\-in\-url\fP multiple times has no extra effect. Disable it again with \-\-no-disallow-username-in-url. Example: .nf curl --disallow-username-in-url https://example.com .fi See also \fI\-\-proto\fP. .IP "\-\-dns\-interface <interface>" (DNS) Send outgoing DNS requests through the given interface. This option is a counterpart to \fI\-\-interface\fP (which does not affect DNS). The supplied string must be an interface name (not an address). If \fI\-\-dns\-interface\fP is provided several times, the last set value is used. Example: .nf curl --dns-interface eth0 https://example.com .fi For \fI\-\-dns\-interface\fP to work, it requires that the underlying libcurl is built to support c-ares. See also \fI\-\-dns\-ipv4\-addr\fP and \fI\-\-dns\-ipv6\-addr\fP. .IP "\-\-dns\-ipv4\-addr <address>" (DNS) Bind to a specific IP address when making IPv4 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv4 address. If \fI\-\-dns\-ipv4\-addr\fP is provided several times, the last set value is used. Example: .nf curl --dns-ipv4-addr 10.1.2.3 https://example.com .fi For \fI\-\-dns\-ipv4\-addr\fP to work, it requires that the underlying libcurl is built to support c-ares. See also \fI\-\-dns\-interface\fP and \fI\-\-dns\-ipv6\-addr\fP. .IP "\-\-dns\-ipv6\-addr <address>" (DNS) Bind to a specific IP address when making IPv6 DNS requests, so that the DNS requests originate from this address. The argument should be a single IPv6 address. If \fI\-\-dns\-ipv6\-addr\fP is provided several times, the last set value is used. Example: .nf curl --dns-ipv6-addr 2a04:4e42::561 https://example.com .fi For \fI\-\-dns\-ipv6\-addr\fP to work, it requires that the underlying libcurl is built to support c-ares. See also \fI\-\-dns\-interface\fP and \fI\-\-dns\-ipv4\-addr\fP. .IP "\-\-dns\-servers <addresses>" (DNS) Set the list of DNS servers to be used instead of the system default. The list of IP addresses should be separated with commas. Port numbers may also optionally be given, appended to the IP address separated with a colon. If \fI\-\-dns\-servers\fP is provided several times, the last set value is used. Examples: .nf curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com curl --dns-servers 10.0.0.1:53 https://example.com .fi For \fI\-\-dns\-servers\fP to work, it requires that the underlying libcurl is built to support c-ares. See also \fI\-\-dns\-interface\fP and \fI\-\-dns\-ipv4\-addr\fP. .IP "\-\-doh\-cert\-status" (DNS) Same as \fI\-\-cert\-status\fP but used for DoH (DNS\-over\-HTTPS). Verify the status of the DoH servers\(aq certificate by using the Certificate Status Request (aka. OCSP stapling) TLS extension. If this option is enabled and the DoH server sends an invalid (e.g. expired) response, if the response suggests that the server certificate has been revoked, or no response at all is received, the verification fails. This support is currently only implemented in the OpenSSL and GnuTLS backends. Providing \fI\-\-doh\-cert\-status\fP multiple times has no extra effect. Disable it again with \-\-no-doh-cert-status. Example: .nf curl --doh-cert-status --doh-url https://doh.example https://example.com .fi Added in 7.76.0. See also \fI\-\-doh\-insecure\fP. .IP "\-\-doh\-insecure" (DNS) By default, every connection curl makes to a DoH server is verified to be secure before the transfer takes place. This option tells curl to skip the verification step and proceed without checking. \fBWARNING\fP: using this option makes the DoH transfer and name resolution insecure. This option is equivalent to \fI\-\-insecure\fP and \fI\-\-proxy\-insecure\fP but used for DoH (DNS\-over\-HTTPS) only. Providing \fI\-\-doh\-insecure\fP multiple times has no extra effect. Disable it again with \-\-no-doh-insecure. Example: .nf curl --doh-insecure --doh-url https://doh.example https://example.com .fi Added in 7.76.0. See also \fI\-\-doh\-url\fP, \fI\-\-insecure\fP and \fI\-\-proxy\-insecure\fP. .IP "\-\-doh\-url <URL>" (DNS) Specify which DNS\-over\-HTTPS (DoH) server to use to resolve hostnames, instead of using the default name resolver mechanism. The URL must be HTTPS. Some SSL options that you set for your transfer also apply to DoH since the name lookups take place over SSL. The certificate verification settings are not inherited but are controlled separately via \fI\-\-doh\-insecure\fP and \fI\-\-doh\-cert\-status\fP. By default, DoH is bypassed when initially looking up DNS records of the DoH server. You can specify the IP address(es) of the DoH server with \fI\-\-resolve\fP to avoid this. This option is unset if an empty string "" is used as the URL. (Added in 7.85.0) If \fI\-\-doh\-url\fP is provided several times, the last set value is used. Examples: .nf curl --doh-url https://doh.example https://example.com curl --doh-url https://doh.example --resolve doh.example:443:192.0.2.1 https://example.com .fi See also \fI\-\-doh\-insecure\fP. .IP "\-\-dump\-ca\-embed" (TLS) Write the CA bundle embedded in curl to standard output, then quit. If curl was not built with a default CA bundle embedded, the output is empty. Providing \fI\-\-dump\-ca\-embed\fP multiple times has no extra effect. Disable it again with \-\-no-dump-ca-embed. Example: .nf curl --dump-ca-embed .fi Added in 8.10.0. See also \fI\-\-ca\-native\fP, \fI\-\-cacert\fP, \fI\-\-capath\fP, \fI\-\-proxy\-ca\-native\fP, \fI\-\-proxy\-cacert\fP and \fI\-\-proxy\-capath\fP. .IP "\-D, \-\-dump\-header <filename>" (HTTP FTP) Write the received protocol headers to the specified file. If no headers are received, the use of this option creates an empty file. Specify "\-" as filename (a single minus) to have it written to stdout. Starting in curl 8.10.0, specify "%" (a single percent sign) as filename writes the output to stderr. When used in FTP, the FTP server response lines are considered being "headers" and thus are saved there. Starting in curl 8.11.0, using the \fI\-\-create\-dirs\fP option can also create missing directory components for the path provided in \fI\-\-dump\-header\fP. Having multiple transfers in one set of operations (i.e. the URLs in one \fI\-\-next\fP clause), appends them to the same file, separated by a blank line. If \fI\-\-dump\-header\fP is provided several times, the last set value is used. Examples: .nf curl --dump-header store.txt https://example.com curl --dump-header - https://example.com -o save .fi See also \fI\-\-output\fP. .IP "\-\-ech <config>" (HTTPS) Specify how to do ECH (Encrypted Client Hello). The values allowed for <config> can be: .RS .IP false Do not attempt ECH. The is the default. .IP grease Send a GREASE ECH extension .IP true Attempt ECH if possible, but do not fail if ECH is not attempted. (The connection fails if ECH is attempted but fails.) .IP hard Attempt ECH and fail if that is not possible. ECH only works with TLS 1.3 and also requires using DoH or providing an ECHConfigList on the command line. .IP ecl:<b64val> A base64 encoded ECHConfigList that is used for ECH. .IP pn:<name> A name to use to over\-ride the "public_name" field of an ECHConfigList (only available with OpenSSL TLS support) .RE .IP Most ECH related errors cause error \fICURLE_ECH_REQUIRED\fP (101). If \fI\-\-ech\fP is provided several times, the last set value is used. Example: .nf curl --ech true https://example.com .fi Added in 8.8.0. See also \fI\-\-doh\-url\fP. .IP "\-\-egd\-file <file>" (TLS) Deprecated option (added in 7.84.0). Prior to that it only had an effect on curl if built to use old versions of OpenSSL. Specify the path name to the Entropy Gathering Daemon socket. The socket is used to seed the random engine for SSL connections. If \fI\-\-egd\-file\fP is provided several times, the last set value is used. Example: .nf curl --egd-file /random/here https://example.com .fi See also \fI\-\-random\-file\fP. .IP "\-\-engine <name>" (TLS) Select the OpenSSL crypto engine to use for cipher operations. Use "\fI\-\-engine\fP list" to print a list of build\-time supported engines. Note that not all (and possibly none) of the engines may be available at runtime. The OpenSSL concept "engines" has been superseded by "providers" in OpenSSL 3, and this option should work fine to specify such as well. If \fI\-\-engine\fP is provided several times, the last set value is used. Example: .nf curl --engine flavor https://example.com .fi See also \fI\-\-ciphers\fP and \fI\-\-curves\fP. .IP "\-\-etag\-compare <file>" (HTTP) Make a conditional HTTP request for the specific ETag read from the given file by sending a custom If\-None\-Match header using the stored ETag. For correct results, make sure that the specified file contains only a single line with the desired ETag. A non\-existing or empty file is treated as an empty ETag. Use the option \fI\-\-etag\-save\fP to first save the ETag from a response, and then use this option to compare against the saved ETag in a subsequent request. Use this option with a single URL only. If \fI\-\-etag\-compare\fP is provided several times, the last set value is used. Example: .nf curl --etag-compare etag.txt https://example.com .fi Added in 7.68.0. See also \fI\-\-etag\-save\fP and \fI\-\-time\-cond\fP. .IP "\-\-etag\-save <file>" (HTTP) Save an HTTP ETag to the specified file. An ETag is a caching related header, usually returned in a response. Use this option with a single URL only. If no ETag is sent by the server, an empty file is created. In many situations you want to use an existing etag in the request to avoid downloading the same resource again but also save the new etag if it has indeed changed, by using both etag options \fI\-\-etag\-save\fP and \fI\-\-etag\-compare\fP with the same filename, in the same command line. Starting in curl 8.12.0, using the \fI\-\-create\-dirs\fP option can also create missing directory components for the path provided in \fI\-\-etag\-save\fP. If \fI\-\-etag\-save\fP is provided several times, the last set value is used. Example: .nf curl --etag-save storetag.txt https://example.com .fi Added in 7.68.0. See also \fI\-\-etag\-compare\fP. .IP "\-\-expect100\-timeout <seconds>" (HTTP) Maximum time in seconds that you allow curl to wait for a 100\-continue response when curl emits an Expects: 100\-continue header in its request. By default curl waits one second. This option accepts decimal values. When curl stops waiting, it continues as if a response was received. The decimal value needs to be provided using a dot (".") as decimal separator \- not the local version even if it might be using another separator. If \fI\-\-expect100\-timeout\fP is provided several times, the last set value is used. Example: .nf curl --expect100-timeout 2.5 -T file https://example.com .fi See also \fI\-\-connect\-timeout\fP. .IP "\-f, \-\-fail" (HTTP) Fail with error code 22 and with no response body output at all for HTTP transfers returning HTTP response codes at 400 or greater. In normal cases when an HTTP server fails to deliver a document, it returns a body of text stating so (which often also describes why and more) and a 4xx HTTP response code. This command line option prevents curl from outputting that data and instead returns error 22 early. By default, curl does not consider HTTP response codes to indicate failure. To get both the error code and also save the content, use \fI\-\-fail\-with\-body\fP instead. This method is not fail\-safe and there are occasions where non\-successful response codes slip through, especially when authentication is involved (response codes 401 and 407). Providing \fI\-\-fail\fP multiple times has no extra effect. Disable it again with \-\-no-fail. Example: .nf curl --fail https://example.com .fi This option is mutually exclusive with \fI\-\-fail\-with\-body\fP. See also \fI\-\-fail\-with\-body\fP and \fI\-\-fail\-early\fP. .IP "\-\-fail\-early" Fail and exit on the first detected transfer error. When curl is used to do multiple transfers on the command line, it attempts to operate on each given URL, one by one. By default, it ignores errors if there are more URLs given and the last URL\(aqs success determines the error code curl returns. Early failures are "hidden" by subsequent successful transfers. Using this option, curl instead returns an error on the first transfer that fails, independent of the amount of URLs that are given on the command line. This way, no transfer failures go undetected by scripts and similar. This option does not imply \fI\-\-fail\fP, which causes transfers to fail due to the server\(aqs HTTP status code. You can combine the two options, however note \fI\-\-fail\fP is not global and is therefore contained by \fI\-\-next\fP. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-fail\-early\fP multiple times has no extra effect. Disable it again with \-\-no-fail-early. Example: .nf curl --fail-early https://example.com https://two.example .fi See also \fI\-\-fail\fP and \fI\-\-fail\-with\-body\fP. .IP "\-\-fail\-with\-body" (HTTP) Return an error on server errors where the HTTP response code is 400 or greater). In normal cases when an HTTP server fails to deliver a document, it returns an HTML document stating so (which often also describes why and more). This option allows curl to output and save that content but also to return error 22. This is an alternative option to \fI\-\-fail\fP which makes curl fail for the same circumstances but without saving the content. Providing \fI\-\-fail\-with\-body\fP multiple times has no extra effect. Disable it again with \-\-no-fail-with-body. Example: .nf curl --fail-with-body https://example.com .fi This option is mutually exclusive with \fI\-\-fail\fP. Added in 7.76.0. See also \fI\-\-fail\fP and \fI\-\-fail\-early\fP. .IP "\-\-false\-start" (TLS) No TLS backend currently supports this feature. Use false start during the TLS handshake. False start is a mode where a TLS client starts sending application data before verifying the server\(aqs Finished message, thus saving a round trip when performing a full handshake. Providing \fI\-\-false\-start\fP multiple times has no extra effect. Disable it again with \-\-no-false-start. Example: .nf curl --false-start https://example.com .fi See also \fI\-\-tcp\-fastopen\fP. .IP "\-\-follow" (HTTP) Instructs curl to follow HTTP redirects and to do the custom request method set with \fI\-\-request\fP when following redirects as the HTTP specification says. The method string set with \fI\-\-request\fP is used in subsequent requests for the status codes 307 or 308, but may be reset to GET for 301, 302 and 303. This is subtly different than \fI\-\-location\fP, as that option always set the custom method in all subsequent requests independent of response code. Restrict which protocols a redirect is accepted to follow with \fI\-\-proto\-redir\fP. When \fI\-\-netrc\fP is used in combination with this option, credentials for the followed\-to hosts may also be selected from that file. Providing \fI\-\-follow\fP multiple times has no extra effect. Disable it again with \-\-no-follow. Example: .nf curl -X POST --follow https://example.com .fi Added in 8.16.0. See also \fI\-\-request\fP, \fI\-\-location\fP, \fI\-\-proto\-redir\fP and \fI\-\-max\-redirs\fP. .IP "\-F, \-\-form <name=content>" (HTTP SMTP IMAP) For the HTTP protocol family, emulate a filled\-in form in which a user has pressed the submit button. This makes curl POST data using the Content\-Type multipart/form\-data according to RFC 2388. For SMTP and IMAP protocols, this composes a multipart mail message to transmit. This enables uploading of binary files etc. To force the \(aqcontent\(aq part to be a file, prefix the filename with an @ sign. To get the content part from a file, prefix the filename with the symbol <. The difference between @ and < is then that @ makes a file get attached in the post as a file upload, while the < makes a text field and gets the contents for that text field from a file. Read content from stdin instead of a file by using a single "\-" as filename. This goes for both @ and < constructs. When stdin is used, the contents is buffered in memory first by curl to determine its size and allow a possible resend. Defining a part\(aqs data from a named non\-regular file (such as a named pipe or similar) is not subject to buffering and is instead read at transmission time; since the full size is unknown before the transfer starts, such data is sent as chunks by HTTP and rejected by IMAP. Example: send an image to an HTTP server, where \(aqprofile\(aq is the name of the form\-field to which the file \fBportrait.jpg\fP is the input: .nf curl \-F profile=@portrait.jpg https://example.com/upload.cgi .fi Example: send your name and shoe size in two text fields to the server: .nf curl \-F name=John \-F shoesize=11 https://example.com/ .fi Example: send your essay in a text field to the server. Send it as a plain text field, but get the contents for it from a local file: .nf curl \-F "story=<hugefile.txt" https://example.com/ .fi You can also instruct curl what Content\-Type to use by using "type=", in a manner similar to: .nf curl \-F "web=@index.html;type=text/html" example.com .fi or .nf curl \-F "name=daniel;type=text/foo" example.com .fi You can also explicitly change the name field of a file upload part by setting filename=, like this: .nf curl \-F "file=@localfile;filename=nameinpost" example.com .fi If filename/path contains \(aq,\(aq or \(aq;\(aq, it must be quoted by double\-quotes like: .nf curl \-F "file=@\\"local,file\\";filename=\\"name;in;post\\"" \\ https://example.com .fi or .nf curl \-F \(aqfile=@"local,file";filename="name;in;post"\(aq \\ https://example.com .fi Note that if a filename/path is quoted by double\-quotes, any double\-quote or backslash within the filename must be escaped by backslash. Quoting must also be applied to non\-file data if it contains semicolons, leading/trailing spaces or leading double quotes: .nf curl \-F \(aqcolors="red; green; blue";type=text/x\-myapp\(aq \\ https://example.com .fi You can add custom headers to the field by setting headers=, like .nf curl \-F "submit=OK;headers=\\"X\-submit\-type: OK\\"" example.com .fi or .nf curl \-F "submit=OK;headers=@headerfile" example.com .fi The headers= keyword may appear more than once and above notes about quoting apply. When headers are read from a file, empty lines and lines starting with \(aq#\(aq are ignored; each header can be folded by splitting between two words and starting the continuation line with a space; embedded carriage\-returns and trailing spaces are stripped. Here is an example of a header file contents: .nf # This file contains two headers. X\-header\-1: this is a header # The following header is folded. X\-header\-2: this is another header .fi To support sending multipart mail messages, the syntax is extended as follows: - name can be omitted: the equal sign is the first character of the argument, - if data starts with \(aq(\(aq, this signals to start a new multipart: it can be followed by a content type specification. - a multipart can be terminated with a \(aq=)\(aq argument. Example: the following command sends an SMTP mime email consisting in an inline part in two alternative formats: plain text and HTML. It attaches a text file: .nf curl \-F \(aq=(;type=multipart/alternative\(aq \\ \-F \(aq=plain text message\(aq \\ \-F \(aq= <body>HTML message</body>;type=text/html\(aq \\ \-F \(aq=)\(aq \-F \(aq=@textfile.txt\(aq ... smtp://example.com .fi Data can be encoded for transfer using encoder=. Available encodings are \fIbinary\fP and \fI8bit\fP that do nothing else than adding the corresponding Content\-Transfer\-Encoding header, \fI7bit\fP that only rejects 8\-bit characters with a transfer error, \fIquoted\-printable\fP and \fIbase64\fP that encodes data according to the corresponding schemes, limiting lines length to 76 characters. Example: send multipart mail with a quoted\-printable text message and a base64 attached file: .nf curl \-F \(aq=text message;encoder=quoted\-printable\(aq \\ \-F \(aq=@localfile;encoder=base64\(aq ... smtp://example.com .fi \fI\-\-form\fP can be used several times in a command line Example: .nf curl --form "name=curl" --form "file=@loadthis" https://example.com .fi This option is mutually exclusive with \fI\-\-data\fP, \fI\-\-head\fP and \fI\-\-upload\-file\fP. See also \fI\-\-data\fP, \fI\-\-form\-string\fP and \fI\-\-form\-escape\fP. .IP "\-\-form\-escape" (HTTP IMAP SMTP) Pass on names of multipart form fields and files using backslash\-escaping instead of percent\-encoding. If \fI\-\-form\-escape\fP is provided several times, the last set value is used. Example: .nf curl --form-escape -F 'field\\name=curl' -F 'file=@load"this' https://example.com .fi Added in 7.81.0. See also \fI\-\-form\fP. .IP "\-\-form\-string <name=string>" (HTTP SMTP IMAP) Similar to \fI\-\-form\fP except that the value string for the named parameter is used literally. Leading @ and < characters, and the ";type=" string in the value have no special meaning. Use this in preference to \fI\-\-form\fP if there is any possibility that the string value may accidentally trigger the @ or < features of \fI\-\-form\fP. \fI\-\-form\-string\fP can be used several times in a command line Example: .nf curl --form-string "name=data" https://example.com .fi See also \fI\-\-form\fP. .IP "\-\-ftp\-account <data>" (FTP) When an FTP server asks for "account data" after username and password has been provided, this data is sent off using the ACCT command. If \fI\-\-ftp\-account\fP is provided several times, the last set value is used. Example: .nf curl --ftp-account "mr.robot" ftp://example.com/ .fi See also \fI\-\-user\fP. .IP "\-\-ftp\-alternative\-to\-user <command>" (FTP) If authenticating with the USER and PASS commands fails, send this command. When connecting to Tumbleweed\(aqs Secure Transport server over FTPS using a client certificate, using "SITE AUTH" tells the server to retrieve the username from the certificate. If \fI\-\-ftp\-alternative\-to\-user\fP is provided several times, the last set value is used. Example: .nf curl --ftp-alternative-to-user "U53r" ftp://example.com .fi See also \fI\-\-ftp\-account\fP and \fI\-\-user\fP. .IP "\-\-ftp\-create\-dirs" (FTP SFTP) When an FTP or SFTP URL/operation uses a path that does not currently exist on the server, the standard behavior of curl is to fail. Using this option, curl instead attempts to create missing directories. Providing \fI\-\-ftp\-create\-dirs\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-create-dirs. Example: .nf curl --ftp-create-dirs -T file ftp://example.com/remote/path/file .fi See also \fI\-\-create\-dirs\fP. .IP "\-\-ftp\-method <method>" (FTP) Control what method curl should use to reach a file on an FTP(S) server. The method argument should be one of the following alternatives: .RS .IP multicwd Do a single CWD operation for each path part in the given URL. For deep hierarchies this means many commands. This is how RFC 1738 says it should be done. This is the default but the slowest behavior. .IP nocwd Do no CWD at all. curl does SIZE, RETR, STOR etc and gives the full path to the server for each of these commands. This is the fastest behavior. .IP singlecwd Do one CWD with the full target directory and then operate on the file \&"normally" (like in the multicwd case). This is somewhat more standards compliant than "nocwd" but without the full penalty of "multicwd". .RE .IP If \fI\-\-ftp\-method\fP is provided several times, the last set value is used. Examples: .nf curl --ftp-method multicwd ftp://example.com/dir1/dir2/file curl --ftp-method nocwd ftp://example.com/dir1/dir2/file curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file .fi See also \fI\-\-list\-only\fP. .IP "\-\-ftp\-pasv" (FTP) Use passive mode for the data connection. Passive is the internal default behavior, but using this option can be used to override a previous \fI\-\-ftp\-port\fP option. Reversing an enforced passive really is not doable but you must then instead enforce the correct \fI\-\-ftp\-port\fP again. Passive mode means that curl tries the EPSV command first and then PASV, unless \fI\-\-disable\-epsv\fP is used. Providing \fI\-\-ftp\-pasv\fP multiple times has no extra effect. Example: .nf curl --ftp-pasv ftp://example.com/ .fi This option is mutually exclusive with \fI\-\-ftp\-port\fP. See also \fI\-\-disable\-epsv\fP. .IP "\-P, \-\-ftp\-port <address>" (FTP) Reverse the default initiator/listener roles when connecting with FTP. This option makes curl use active mode. curl then commands the server to connect back to the client\(aqs specified address and port, while passive mode asks the server to setup an IP address and port for it to connect to. <address> should be one of: .RS .IP interface e.g. \fBeth0\fP to specify which interface\(aqs IP address you want to use (Unix only) .IP "IP address" e.g. \fB192.168.10.1\fP to specify the exact IP address .IP hostname e.g. \fBmy.host.domain\fP to specify the machine .IP - make curl pick the same IP address that is already used for the control connection. This is the recommended choice. .RE .IP Disable the use of PORT with \fI\-\-ftp\-pasv\fP. Disable the attempt to use the EPRT command instead of PORT by using \fI\-\-disable\-eprt\fP. EPRT is really PORT++. You can also append ":[start]\-[end]" to the right of the address, to tell curl what TCP port range to use. That means you specify a port range, from a lower to a higher number. A single number works as well, but do note that it increases the risk of failure since the port may not be available. If \fI\-\-ftp\-port\fP is provided several times, the last set value is used. Examples: .nf curl -P - ftp:/example.com curl -P eth0 ftp:/example.com curl -P 192.168.0.2 ftp:/example.com .fi See also \fI\-\-ftp\-pasv\fP and \fI\-\-disable\-eprt\fP. .IP "\-\-ftp\-pret" (FTP) Send a PRET command before PASV (and EPSV). Certain FTP servers, mainly drftpd, require this non\-standard command for directory listings as well as up and downloads in PASV mode. Providing \fI\-\-ftp\-pret\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-pret. Example: .nf curl --ftp-pret ftp://example.com/ .fi See also \fI\-\-ftp\-port\fP and \fI\-\-ftp\-pasv\fP. .IP "\-\-ftp\-skip\-pasv\-ip" (FTP) Do not use the IP address the server suggests in its response to curl\(aqs PASV command when curl connects the data connection. Instead curl reuses the same IP address it already uses for the control connection. This option is enabled by default (added in 7.74.0). This option has no effect if PORT, EPRT or EPSV is used instead of PASV. Providing \fI\-\-ftp\-skip\-pasv\-ip\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-skip-pasv-ip. Example: .nf curl --ftp-skip-pasv-ip ftp://example.com/ .fi See also \fI\-\-ftp\-pasv\fP. .IP "\-\-ftp\-ssl\-ccc" (FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS layer after authenticating. The rest of the control channel communication is unencrypted. This allows NAT routers to follow the FTP transaction. The default mode is passive. Providing \fI\-\-ftp\-ssl\-ccc\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-ssl-ccc. Example: .nf curl --ftp-ssl-ccc ftps://example.com/ .fi See also \fI\-\-ssl\fP and \fI\-\-ftp\-ssl\-ccc\-mode\fP. .IP "\-\-ftp\-ssl\-ccc\-mode <active/passive>" (FTP) Set the CCC mode. The passive mode does not initiate the shutdown, but instead waits for the server to do it, and does not reply to the shutdown from the server. The active mode initiates the shutdown and waits for a reply from the server. Providing \fI\-\-ftp\-ssl\-ccc\-mode\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-ssl-ccc-mode. Example: .nf curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/ .fi See also \fI\-\-ftp\-ssl\-ccc\fP. .IP "\-\-ftp\-ssl\-control" (FTP) Require SSL/TLS for the FTP login, clear for transfer. Allows secure authentication, but non\-encrypted data transfers for efficiency. Fails the transfer if the server does not support SSL/TLS. Providing \fI\-\-ftp\-ssl\-control\fP multiple times has no extra effect. Disable it again with \-\-no-ftp-ssl-control. Example: .nf curl --ftp-ssl-control ftp://example.com .fi See also \fI\-\-ssl\fP. .IP "\-G, \-\-get" (HTTP) When used, this option makes all data specified with \fI\-\-data\fP, \fI\-\-data\-binary\fP or \fI\-\-data\-urlencode\fP to be used in an HTTP GET request instead of the POST request that otherwise would be used. curl appends the provided data to the URL as a query string. If used in combination with \fI\-\-head\fP, the POST data is instead appended to the URL with a HEAD request. Providing \fI\-\-get\fP multiple times has no extra effect. Disable it again with \-\-no-get. Examples: .nf curl --get https://example.com curl --get -d "tool=curl" -d "age=old" https://example.com curl --get -I -d "tool=curl" https://example.com .fi See also \fI\-\-data\fP and \fI\-\-request\fP. .IP "\-g, \-\-globoff" Switch off the URL globbing function. When you set this option, you can specify URLs that contain the letters {}[] without having curl itself interpret them. Note that these letters are not normal legal URL contents but they should be encoded according to the URI standard. curl detects numerical IPv6 addresses when used in URLs and excludes them from the treatment, so they can still be used without having to disable globbing. Providing \fI\-\-globoff\fP multiple times has no extra effect. Disable it again with \-\-no-globoff. Example: .nf curl -g "https://example.com/{[]}}}}" .fi See also \fI\-\-config\fP and \fI\-\-disable\fP. .IP "\-\-happy\-eyeballs\-timeout\-ms <ms>" Set the timeout for Happy Eyeballs. Happy Eyeballs is an algorithm that attempts to connect to both IPv4 and IPv6 addresses for dual\-stack hosts, giving IPv6 a head\-start of the specified number of milliseconds. If the IPv6 address cannot be connected to within that time, then a connection attempt is made to the IPv4 address in parallel. The first connection to be established is the one that is used. The range of suggested useful values is limited. Happy Eyeballs RFC 6555 says \&"It is RECOMMENDED that connection attempts be paced 150\-250 ms apart to balance human factors against network load." libcurl currently defaults to 200 ms. Firefox and Chrome currently default to 300 ms. If \fI\-\-happy\-eyeballs\-timeout\-ms\fP is provided several times, the last set value is used. Example: .nf curl --happy-eyeballs-timeout-ms 500 https://example.com .fi See also \fI\-\-max\-time\fP and \fI\-\-connect\-timeout\fP. .IP "\-\-haproxy\-clientip <ip>" (HTTP) Set a client IP in HAProxy PROXY protocol v1 header at the beginning of the connection. For valid requests, IPv4 addresses must be indicated as a series of exactly 4 integers in the range [0..255] inclusive written in decimal representation separated by exactly one dot between each other. Heading zeroes are not permitted in front of numbers in order to avoid any possible confusion with octal numbers. IPv6 addresses must be indicated as series of 4 hexadecimal digits (upper or lower case) delimited by colons between each other, with the acceptance of one double colon sequence to replace the largest acceptable range of consecutive zeroes. The total number of decoded bits must be exactly 128. Otherwise, any string can be accepted for the client IP and get sent. It replaces \fI\-\-haproxy\-protocol\fP if used, it is not necessary to specify both flags. If \fI\-\-haproxy\-clientip\fP is provided several times, the last set value is used. Example: .nf curl --haproxy-clientip $IP .fi Added in 8.2.0. See also \fI\-\-proxy\fP. .IP "\-\-haproxy\-protocol" (HTTP) Send a HAProxy PROXY protocol v1 header at the beginning of the connection. This is used by some load balancers and reverse proxies to indicate the client\(aqs true IP address and port. This option is primarily useful when sending test requests to a service that expects this header. Providing \fI\-\-haproxy\-protocol\fP multiple times has no extra effect. Disable it again with \-\-no-haproxy-protocol. Example: .nf curl --haproxy-protocol https://example.com .fi See also \fI\-\-proxy\fP. .IP "\-I, \-\-head" (HTTP FTP FILE) Fetch the headers only. HTTP\-servers feature the command HEAD which this uses to get nothing but the header of a document. When used on an FTP or FILE URL, curl displays the file size and last modification time only. Providing \fI\-\-head\fP multiple times has no extra effect. Disable it again with \-\-no-head. Example: .nf curl -I https://example.com .fi See also \fI\-\-get\fP, \fI\-\-verbose\fP and \fI\-\-trace\-ascii\fP. .IP "\-H, \-\-header <header/@file>" (HTTP IMAP SMTP) Extra header to include in information sent. When used within an HTTP request, it is added to the regular request headers. For an IMAP or SMTP MIME uploaded mail built with \fI\-\-form\fP options, it is prepended to the resulting MIME document, effectively including it at the mail global level. It does not affect raw uploaded mails. You may specify any number of extra headers. Note that if you should add a custom header that has the same name as one of the internal ones curl would use, your externally set header is used instead of the internal one. This allows you to make even trickier stuff than curl would normally do. You should not replace internally set headers without knowing perfectly well what you are doing. Remove an internal header by giving a replacement without content on the right side of the colon, as in: \-H "Host:". If you send the custom header with no\-value then its header must be terminated with a semicolon, such as \-H \&"X\-Custom\-Header;" to send "X\-Custom\-Header:". curl makes sure that each header you add/replace is sent with the proper end\-of\-line marker, you should thus \fBnot\fP add that as a part of the header content: do not add newlines or carriage returns, they only mess things up for you. curl passes on the verbatim string you give it without any filter or other safe guards. That includes white space and control characters. This option can take an argument in @filename style, which then adds a header for each line in the input file. Using @\- makes curl read the header file from stdin. Please note that most anti\-spam utilities check the presence and value of several MIME mail headers: these are "From:", "To:", "Date:" and "Subject:" among others and should be added with this option. You need \fI\-\-proxy\-header\fP to send custom headers intended for an HTTP proxy. Passing on a "Transfer\-Encoding: chunked" header when doing an HTTP request with a request body, makes curl send the data using chunked encoding. \fBWARNING\fP: headers set with this option are set in all HTTP requests \- even after redirects are followed, like when told with \fI\-\-location\fP. This can lead to the header being sent to other hosts than the original host, so sensitive headers should be used with caution combined with following redirects. \&"Authorization:" and "Cookie:" headers are explicitly \fInot\fP passed on in HTTP requests when following redirects to other origins, unless \fI\-\-location\-trusted\fP is used. \fI\-\-header\fP can be used several times in a command line Examples: .nf curl -H "X-First-Name: Joe" https://example.com curl -H "User-Agent: yes-please/2000" https://example.com curl -H "Host:" https://example.com curl -H @headers.txt https://example.com .fi See also \fI\-\-user\-agent\fP, \fI\-\-referer\fP and \fI\-\-proxy\-header\fP. .IP "\-h, \-\-help <subject>" Usage help. Provide help for the subject given as an optional argument. If no argument is provided, curl displays the most important command line arguments. The argument can either be a \fBcategory\fP or a \fBcommand line option\fP. When a category is provided, curl shows all command line options within the given category. Specify category "all" to list all available options. If "category" is specified, curl displays all available help categories. If the provided subject is instead an existing command line option, specified either in its short form with a single dash and a single letter, or in the long form with two dashes and a longer name, curl displays a help text for that option in the terminal. The help output is extensive for some options. If the provided command line option is not known, curl says so. Examples: .nf curl --help all curl --help --insecure curl --help -f .fi See also \fI\-\-verbose\fP. .IP "\-\-hostpubmd5 <md5>" (SFTP SCP) Pass a string containing 32 hexadecimal digits. The string should be the 128 bit \fBMD5\fP checksum of the remote host\(aqs public key, curl refuses the connection with the host unless the checksums match. If \fI\-\-hostpubmd5\fP is provided several times, the last set value is used. Example: .nf curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/ .fi See also \fI\-\-hostpubsha256\fP. .IP "\-\-hostpubsha256 <sha256>" (SFTP SCP) Pass a string containing a Base64\-encoded SHA256 hash of the remote host\(aqs public key. curl refuses the connection with the host unless the hashes match. This feature requires libcurl to be built with libssh2 and does not work with other SSH backends. If \fI\-\-hostpubsha256\fP is provided several times, the last set value is used. Example: .nf curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/ .fi Added in 7.80.0. See also \fI\-\-hostpubmd5\fP. .IP "\-\-hsts <filename>" (HTTPS) Enable HSTS for the transfer. If the filename points to an existing HSTS cache file, that is used. After a completed transfer, the cache is saved to the filename again if it has been modified. If curl is told to use HTTP:// for a transfer involving a hostname that exists in the HSTS cache, it upgrades the transfer to use HTTPS. Each HSTS cache entry has an individual lifetime after which the upgrade is no longer performed. Specify a "" filename (zero length) to avoid loading/saving and make curl handle HSTS in memory. You may want to restrict your umask to prevent other users on the same system to access the created file. If this option is used several times, curl loads contents from all the files but the last one is used for saving. Since curl 8.20.0, curl keeps no more than the most recently added 10,000 unique HSTS hostnames. \fI\-\-hsts\fP can be used several times in a command line Example: .nf curl --hsts cache.txt https://example.com .fi Added in 7.74.0. See also \fI\-\-proto\fP. .IP "\-\-http0.9" (HTTP) Accept an HTTP version 0.9 response. HTTP/0.9 is a response without headers and therefore you can also connect with this to non\-HTTP servers and still get a response since curl transparently downgrades \- if allowed. HTTP/0.9 is disabled by default (added in 7.66.0) Providing \fI\-\-http0.9\fP multiple times has no extra effect. Disable it again with \-\-no-http0.9. Example: .nf curl --http0.9 https://example.com .fi See also \fI\-\-http1.1\fP, \fI\-\-http2\fP and \fI\-\-http3\fP. .IP "\-0, \-\-http1.0" (HTTP) Use HTTP version 1.0 instead of using its internally preferred HTTP version. Providing \fI\-\-http1.0\fP multiple times has no extra effect. Example: .nf curl --http1.0 https://example.com .fi This option is mutually exclusive with \fI\-\-http1.1\fP, \fI\-\-http2\fP, \fI\-\-http2\-prior\-knowledge\fP and \fI\-\-http3\fP. See also \fI\-\-http0.9\fP and \fI\-\-http1.1\fP. .IP "\-\-http1.1" (HTTP) Use HTTP version 1.1. This is the default with HTTP:// URLs. Providing \fI\-\-http1.1\fP multiple times has no extra effect. Example: .nf curl --http1.1 https://example.com .fi This option is mutually exclusive with \fI\-\-http1.0\fP, \fI\-\-http2\fP, \fI\-\-http2\-prior\-knowledge\fP and \fI\-\-http3\fP. See also \fI\-\-http1.0\fP and \fI\-\-http0.9\fP. .IP "\-\-http2" (HTTP) Use HTTP/2. For HTTPS, this means curl negotiates HTTP/2 in the TLS handshake. curl does this by default. For HTTP, this means curl attempts to upgrade the request to HTTP/2 using the Upgrade: request header. When curl uses HTTP/2 over HTTPS, it does not itself insist on TLS 1.2 or higher even though that is required by the specification. A user can add this version requirement with \fI\-\-tlsv1.2\fP. Providing \fI\-\-http2\fP multiple times has no extra effect. Example: .nf curl --http2 https://example.com .fi For \fI\-\-http2\fP to work, it requires that the underlying libcurl is built to support HTTP/2. This option is mutually exclusive with \fI\-\-http1.1\fP, \fI\-\-http1.0\fP, \fI\-\-http2\-prior\-knowledge\fP and \fI\-\-http3\fP. See also \fI\-\-http1.1\fP, \fI\-\-http3\fP, \fI\-\-no\-alpn\fP and \fI\-\-proxy\-http2\fP. .IP "\-\-http2\-prior\-knowledge" (HTTP) Issue a non\-TLS HTTP request using HTTP/2 directly without HTTP/1.1 Upgrade. It requires prior knowledge that the server supports HTTP/2 straight away. HTTPS requests still do HTTP/2 the standard way with negotiated protocol versions in the TLS handshake. Since 8.10.0 if this option is set for an HTTPS request then the application layer protocol version (ALPN) offered to the server is only HTTP/2. Prior to that both HTTP/1.1 and HTTP/2 were offered. Providing \fI\-\-http2\-prior\-knowledge\fP multiple times has no extra effect. Disable it again with \-\-no-http2-prior-knowledge. Example: .nf curl --http2-prior-knowledge https://example.com .fi For \fI\-\-http2\-prior\-knowledge\fP to work, it requires that the underlying libcurl is built to support HTTP/2. This option is mutually exclusive with \fI\-\-http1.1\fP, \fI\-\-http1.0\fP, \fI\-\-http2\fP and \fI\-\-http3\fP. See also \fI\-\-http2\fP and \fI\-\-http3\fP. .IP "\-\-http3" (HTTP) Attempt HTTP/3 to the host in the URL, but fallback to earlier HTTP versions if the HTTP/3 connection establishment fails or is slow. HTTP/3 is only available for HTTPS and not for HTTP URLs. This option allows a user to avoid using the Alt\-Svc method of upgrading to HTTP/3 when you know or suspect that the target speaks HTTP/3 on the given host and port. When asked to use HTTP/3, curl issues a separate attempt to use older HTTP versions with a slight delay, so if the HTTP/3 transfer fails or is slow, curl still tries to proceed with an older HTTP version. The fallback performs the regular negotiation between HTTP/1 and HTTP/2. Use \fI\-\-http3\-only\fP for similar functionality \fIwithout\fP a fallback. curl cannot do HTTP/3 over any proxy. Providing \fI\-\-http3\fP multiple times has no extra effect. Example: .nf curl --http3 https://example.com .fi For \fI\-\-http3\fP to work, it requires that the underlying libcurl is built to support HTTP/3. This option is mutually exclusive with \fI\-\-http1.1\fP, \fI\-\-http1.0\fP, \fI\-\-http2\fP, \fI\-\-http2\-prior\-knowledge\fP and \fI\-\-http3\-only\fP. Added in 7.66.0. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-\-http3\-only" (HTTP) Instruct curl to use HTTP/3 to the host in the URL, with no fallback to earlier HTTP versions. HTTP/3 can only be used for HTTPS and not for HTTP URLs. For HTTP, this option triggers an error. This option allows a user to avoid using the Alt\-Svc method of upgrading to HTTP/3 when you know that the target speaks HTTP/3 on the given host and port. This option makes curl fail if a QUIC connection cannot be established, it does not attempt any other HTTP versions on its own. Use \fI\-\-http3\fP for similar functionality \fIwith\fP a fallback. Providing \fI\-\-http3\-only\fP multiple times has no extra effect. Example: .nf curl --http3-only https://example.com .fi For \fI\-\-http3\-only\fP to work, it requires that the underlying libcurl is built to support HTTP/3. This option is mutually exclusive with \fI\-\-http1.1\fP, \fI\-\-http1.0\fP, \fI\-\-http2\fP, \fI\-\-http2\-prior\-knowledge\fP and \fI\-\-http3\fP. Added in 7.88.0. See also \fI\-\-http1.1\fP, \fI\-\-http2\fP and \fI\-\-http3\fP. .IP "\-\-ignore\-content\-length" (FTP HTTP) For HTTP, ignore the Content\-Length header. This is particularly useful for servers running Apache 1.x, which reports incorrect Content\-Length for files larger than 2 gigabytes. For FTP, this makes curl skip the SIZE command to figure out the size before downloading a file. Providing \fI\-\-ignore\-content\-length\fP multiple times has no extra effect. Disable it again with \-\-no-ignore-content-length. Example: .nf curl --ignore-content-length https://example.com .fi See also \fI\-\-ftp\-skip\-pasv\-ip\fP. .IP "\-k, \-\-insecure" (TLS SFTP SCP) By default, every secure connection curl makes is verified to be secure before the transfer takes place. This option makes curl skip the verification step and proceed without checking. When this option is not used for protocols using TLS, curl verifies the server\(aqs TLS certificate before it continues: that the certificate contains the right name which matches the hostname used in the URL and that the certificate has been signed by a CA certificate present in the cert store. See this online resource for further details: \fBhttps://curl.se/docs/sslcerts.html\fP For SFTP and SCP, this option makes curl skip the \fIknown_hosts\fP verification. \fIknown_hosts\fP is a file normally stored in the user\(aqs home directory in the \&".ssh" subdirectory, which contains hostnames and their public keys. \fBWARNING\fP: using this option makes the transfer insecure. When curl uses secure protocols it trusts responses and allows for example HSTS and Alt\-Svc information to be stored and used subsequently. Using \fI\-\-insecure\fP can make curl trust and use such information from malicious servers. Providing \fI\-\-insecure\fP multiple times has no extra effect. Disable it again with \-\-no-insecure. Example: .nf curl --insecure https://example.com .fi See also \fI\-\-proxy\-insecure\fP, \fI\-\-cacert\fP and \fI\-\-capath\fP. .IP "\-\-interface <name>" Perform the operation using a specified interface. You can enter interface name, IP address or hostname. If you prefer to be specific, you can use the following special syntax: .RS .IP if!<name> Interface name. If the provided name does not match an existing interface, curl returns with error 45. .IP host!<name> IP address or hostname. .IP ifhost!<interface>!<host> Interface name and IP address or hostname. This syntax requires libcurl 8.9.0 or later. If the provided name does not match an existing interface, curl returns with error 45. .RE .IP curl does not support using network interface names for this option on Windows. That name resolve operation if a hostname is provided does \fBnot\fP use DNS\-over\-HTTPS even if \fI\-\-doh\-url\fP is set. On Linux this option can be used to specify a \fBVRF\fP (Virtual Routing and Forwarding) device, but the binary then needs to either have the \fBCAP_NET_RAW\fP capability set or to be run as root. If \fI\-\-interface\fP is provided several times, the last set value is used. Examples: .nf curl --interface eth0 https://example.com curl --interface "host!10.0.0.1" https://example.com curl --interface "if!enp3s0" https://example.com .fi See also \fI\-\-dns\-interface\fP. .IP "\-\-ip\-tos <string>" Set Type of Service (TOS) for IPv4 or Traffic Class for IPv6. The values allowed for <string> can be a numeric value between 1 and 255 or one of the following: CS0, CS1, CS2, CS3, CS4, CS5, CS6, CS7, AF11, AF12, AF13, AF21, AF22, AF23, AF31, AF32, AF33, AF41, AF42, AF43, EF, VOICE\-ADMIT, ECT1, ECT0, CE, LE, LOWCOST, LOWDELAY, THROUGHPUT, RELIABILITY, MINCOST If \fI\-\-ip\-tos\fP is provided several times, the last set value is used. Example: .nf curl --ip-tos CS5 https://example.com .fi Added in 8.9.0. See also \fI\-\-tcp\-nodelay\fP and \fI\-\-vlan\-priority\fP. .IP "\-\-ipfs\-gateway <URL>" (IPFS) Specify which gateway to use for IPFS and IPNS URLs. Not specifying this instead makes curl check if the IPFS_GATEWAY environment variable is set, or if a "~/.ipfs/gateway" file holding the gateway URL exists. If you run a local IPFS node, this gateway is by default available under \&"http://localhost:8080". A full example URL would look like: .nf curl \--ipfs\-gateway http://localhost:8080 \\ ipfs://bafybeigagd5nmnn2iys2f3 .fi There are many public IPFS gateways. See for example: https://ipfs.github.io/public\-gateway\-checker/ If you opt to go for a remote gateway you need to be aware that you completely trust the gateway. This might be fine in local gateways that you host yourself. With remote gateways there could potentially be malicious actors returning you data that does not match the request you made, inspect or even interfere with the request. You may not notice this when using curl. A mitigation could be to go for a "trustless" gateway. This means you locally verify the data. Consult the docs page on trusted vs trustless: https://docs.ipfs.tech/reference/http/gateway/#trusted\-vs\-trustless If \fI\-\-ipfs\-gateway\fP is provided several times, the last set value is used. Example: .nf curl --ipfs-gateway https://example.com ipfs:// .fi Added in 8.4.0. See also \fI\-\-help\fP and \fI\-\-manual\fP. .IP "\-4, \-\-ipv4" Request only IPv4 addresses when resolving hostnames, and not for example any IPv6. Providing \fI\-\-ipv4\fP multiple times has no extra effect. Example: .nf curl --ipv4 https://example.com .fi This option is mutually exclusive with \fI\-\-ipv6\fP. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-6, \-\-ipv6" Request only IPv6 addresses when resolving hostnames, and not for example any IPv4. Your resolver may still respond to an IPv6\-only resolve request by returning IPv6 addresses that contain "mapped" IPv4 addresses for compatibility purposes. macOS is known to do this. Providing \fI\-\-ipv6\fP multiple times has no extra effect. Example: .nf curl --ipv6 https://example.com .fi This option is mutually exclusive with \fI\-\-ipv4\fP. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-\-json <data>" (HTTP) Send the specified JSON data in a POST request to the HTTP server. \fI\-\-json\fP works as a shortcut for passing on these three options: .nf -\-data\-binary [arg] -\-header "Content\-Type: application/json" -\-header "Accept: application/json" .fi There is \fBno verification\fP that the passed in data is actual JSON or that the syntax is correct. If you start the data with the letter @, the rest should be a filename to read the data from, or a single dash (\-) if you want curl to read the data from stdin. Posting data from a file named \(aqfoobar\(aq would thus be done with \fI\-\-json\fP @foobar and to instead read the data from stdin, use \fI\-\-json\fP @\-. If this option is used more than once on the same command line, the additional data pieces are concatenated to the previous before sending. The headers this option sets can be overridden with \fI\-\-header\fP as usual. \fI\-\-json\fP can be used several times in a command line Examples: .nf curl --json '{ "drink": "coffee" }' https://example.com curl --json '{ "drink":' --json ' "coffee" }' https://example.com curl --json @prepared https://example.com curl --json @- https://example.com < json.txt .fi This option is mutually exclusive with \fI\-\-form\fP, \fI\-\-head\fP and \fI\-\-upload\-file\fP. Added in 7.82.0. See also \fI\-\-data\-binary\fP and \fI\-\-data\-raw\fP. .IP "\-j, \-\-junk\-session\-cookies" (HTTP) When curl is told to read cookies from a given file, this option makes it discard all session cookies. This has the same effect as if a new session is started. Typical browsers discard session cookies when they are closed down. Session cookies are cookies without a set expiry time. They are meant to only last for "a session". Providing \fI\-\-junk\-session\-cookies\fP multiple times has no extra effect. Disable it again with \-\-no-junk-session-cookies. Example: .nf curl --junk-session-cookies -b cookies.txt https://example.com .fi See also \fI\-\-cookie\fP and \fI\-\-cookie\-jar\fP. .IP "\-\-keepalive\-cnt <integer>" Set the maximum number of keepalive probes TCP should send but get no response before dropping the connection. This option is usually used in conjunction with \fI\-\-keepalive\-time\fP. This option is supported on Linux, *BSD/macOS, Windows >=10.0.16299, Solaris 11.4, and recent AIX, HP\-UX and more. This option has no effect if \fI\-\-no\-keepalive\fP is used. If unspecified, the option defaults to 9. If \fI\-\-keepalive\-cnt\fP is provided several times, the last set value is used. Example: .nf curl --keepalive-cnt 3 https://example.com .fi Added in 8.9.0. See also \fI\-\-keepalive\-time\fP and \fI\-\-no\-keepalive\fP. .IP "\-\-keepalive\-time <seconds>" Set the time a connection needs to remain idle before sending keepalive probes and the time between individual keepalive probes. It is currently effective on operating systems offering the "TCP_KEEPIDLE" and "TCP_KEEPINTVL" socket options (meaning Linux, *BSD/macOS, Windows, Solaris, and recent AIX, HP\-UX and more). Keepalive is used by the TCP stack to detect broken networks on idle connections. The number of missed keepalive probes before declaring the connection down is OS dependent and is commonly 8 (*BSD/macOS/AIX), 9 (Linux/AIX) or 5/10 (Windows), and this number can be changed by specifying the curl option "keepalive\-cnt". Note that this option has no effect if \fI\-\-no\-keepalive\fP is used. If unspecified, the option defaults to 60 seconds. If \fI\-\-keepalive\-time\fP is provided several times, the last set value is used. Example: .nf curl --keepalive-time 20 https://example.com .fi See also \fI\-\-no\-keepalive\fP, \fI\-\-keepalive\-cnt\fP and \fI\-\-max\-time\fP. .IP "\-\-key <key>" (TLS SCP SFTP) Private key filename. Allows you to provide your private key in this separate file. For SSH, if not specified, curl tries the following candidates in order: \&"~/.ssh/id_rsa", "~/.ssh/id_dsa", "./id_rsa", "./id_dsa". If curl is built against OpenSSL library, and the engine pkcs11 or pkcs11 provider is available, then a PKCS#11 URI (RFC 7512) can be used to specify a private key located in a PKCS#11 device. A string beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a PKCS#11 URI is provided, then the \fI\-\-engine\fP option is set as "pkcs11" if none was provided and the \fI\-\-key\-type\fP option is set as "ENG" or "PROV" if none was provided (depending on OpenSSL version). If curl is built against Schannel then this option is ignored for TLS protocols (HTTPS, etc). That backend expects the private key to be already present in the keychain or PKCS#12 file containing the certificate. If \fI\-\-key\fP is provided several times, the last set value is used. Example: .nf curl --cert certificate --key here https://example.com .fi See also \fI\-\-key\-type\fP and \fI\-\-cert\fP. .IP "\-\-key\-type <type>" (TLS) Private key file type. Specify which type your \fI\-\-key\fP provided private key is. DER, PEM, and ENG are supported. If not specified, PEM is assumed. If \fI\-\-key\-type\fP is provided several times, the last set value is used. Example: .nf curl --key-type DER --key here https://example.com .fi See also \fI\-\-key\fP. .IP "\-\-knownhosts <file>" (SCP SFTP) When doing SCP and SFTP transfers, curl automatically checks a database containing identification for all hosts it has ever been used with to verify that the host it connects to is the same as previously. Host keys are stored in such a known hosts file. curl uses the ~/.ssh/known_hosts in the user\(aqs home directory by default. This option lets a user specify a specific file to check the host against. The known hosts check can be disabled with \fI\-\-insecure\fP, but that makes the transfer insecure and is strongly discouraged. If \fI\-\-knownhosts\fP is provided several times, the last set value is used. Example: .nf curl --knownhosts filename --key here https://example.com .fi Added in 8.17.0. See also \fI\-\-hostpubsha256\fP, \fI\-\-hostpubmd5\fP, \fI\-\-insecure\fP and \fI\-\-key\fP. .IP "\-\-krb <level>" (FTP) Deprecated option (added in 8.17.0). It has no function anymore. Enable Kerberos authentication and use. The level must be entered and should be one of "clear", "safe", "confidential", or "private". Should you use a level that is not one of these, "private" is used. If \fI\-\-krb\fP is provided several times, the last set value is used. Example: .nf curl --krb clear ftp://example.com/ .fi For \fI\-\-krb\fP to work, it requires that the underlying libcurl is built to support Kerberos. See also \fI\-\-delegation\fP and \fI\-\-ssl\fP. .IP "\-\-libcurl <file>" Append this option to any ordinary curl command line, and you get libcurl\-using C source code written to the file that does the equivalent of what your command\-line operation does. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-libcurl\fP is provided several times, the last set value is used. Example: .nf curl --libcurl client.c https://example.com .fi See also \fI\-\-verbose\fP. .IP "\-\-limit\-rate <speed>" Specify the maximum transfer rate you want curl to use \- for both downloads and uploads. This feature is useful if you have a limited pipe and you would like your transfer not to use your entire bandwidth. To make it slower than it otherwise would be. The given speed is measured in bytes/second, unless a suffix is appended. Appending \(aqk\(aq or \(aqK\(aq counts the number as kilobytes, \(aqm\(aq or \(aqM\(aq makes it megabytes etc. The supported suffixes (k, M, G, T, P) are 1024\-based. For example 1k is 1024. Examples: 200K, 3m and 1G. The rate limiting logic works on averaging the transfer speed to no more than the set threshold over a period of multiple seconds. If you also use the \fI\-\-speed\-limit\fP option, that option takes precedence and might cripple the rate\-limiting slightly, to help keep the speed\-limit logic working. Starting in curl 8.19.0, the rate can be specified using a fraction as in \&"2.5M" for two and a half megabytes per second. It only works with a period (".") delimiter, independent of what your locale might prefer. If \fI\-\-limit\-rate\fP is provided several times, the last set value is used. Examples: .nf curl --limit-rate 123.45K https://example.com curl --limit-rate 1000 https://example.com curl --limit-rate 10M https://example.com curl --limit-rate 200K --max-time 60 https://example.com .fi See also \fI\-\-rate\fP, \fI\-\-speed\-limit\fP and \fI\-\-speed\-time\fP. .IP "\-l, \-\-list\-only" (FTP POP3 SFTP FILE) When listing an FTP directory, force a name\-only view. Maybe particularly useful if the user wants to machine\-parse the contents of an FTP directory since the normal directory view does not use a standard look or format. When used like this, the option causes an NLST command to be sent to the server instead of LIST. Note: Some FTP servers list only files in their response to NLST; they do not include subdirectories and symbolic links. When listing an SFTP directory, this switch forces a name\-only view, one per line. This is especially useful if the user wants to machine\-parse the contents of an SFTP directory since the normal directory view provides more information than filenames. When retrieving a specific email from POP3, this switch forces a LIST command to be performed instead of RETR. This is particularly useful if the user wants to see if a specific message\-id exists on the server and what size it is. For FILE, this option has no effect yet as directories are always listed in this mode. Note: When combined with \fI\-\-request\fP, this option can be used to send a UIDL command instead, so the user may use the email\(aqs unique identifier rather than its message\-id to make the request. Providing \fI\-\-list\-only\fP multiple times has no extra effect. Disable it again with \-\-no-list-only. Example: .nf curl --list-only ftp://example.com/dir/ .fi See also \fI\-\-quote\fP and \fI\-\-request\fP. .IP "\-\-local\-port <range>" Set a preferred single number or range (FROM\-TO) of local port numbers to use for the connection(s). Note that port numbers by nature are a scarce resource so setting this range to something too narrow might cause unnecessary connection setup failures. If \fI\-\-local\-port\fP is provided several times, the last set value is used. Example: .nf curl --local-port 1000-3000 https://example.com .fi See also \fI\-\-globoff\fP. .IP "\-L, \-\-location" (HTTP) If the server reports that the requested page has moved to a different location (indicated with a Location: header and a 3XX response code), this option makes curl redo the request to the new place. If used together with \fI\-\-show\-headers\fP or \fI\-\-head\fP, headers from all requested pages are shown. When authentication is provided on the command line (for example \fI\-\-user\fP or \fI\-\-oauth2\-bearer\fP), or when sending a cookie with "\-H Cookie:", curl only sends its credentials to the initial host. If a redirect takes curl to a different host, it does not get the credentials passed on. See \fI\-\-location\-trusted\fP on how to change this. When \fI\-\-netrc\fP is used in combination with this option, credentials for the followed\-to hosts may also be selected from that file. Limit the amount of redirects to follow by using the \fI\-\-max\-redirs\fP option. When curl follows a redirect and if the request is a POST, it sends the following request with a GET if the HTTP response was 301, 302, or 303. If the response code was any other 3xx code, curl resends the following request using the same unmodified method. You can tell curl to not change POST requests to GET after a 30x response by using the dedicated options for that: \fI\-\-post301\fP, \fI\-\-post302\fP and \fI\-\-post303\fP. The method set with \fI\-\-request\fP overrides the method curl would otherwise select to use. Restrict which protocols a redirect is accepted to follow with \fI\-\-proto\-redir\fP. Providing \fI\-\-location\fP multiple times has no extra effect. Disable it again with \-\-no-location. Example: .nf curl -L https://example.com .fi See also \fI\-\-resolve\fP, \fI\-\-alt\-svc\fP, \fI\-\-follow\fP, \fI\-\-proto\-redir\fP and \fI\-\-max\-redirs\fP. .IP "\-\-location\-trusted" (HTTP) Instruct curl to follow HTTP redirects like \fI\-\-location\fP, but permit curl to send credentials and other secrets along to other hosts than the initial one. This may or may not introduce a security breach if the site redirects you to a site to which you send this sensitive data to. Another host means that one or more of hostname, protocol scheme or port number changed. This option also allows curl to pass long cookies set explicitly with \fI\-\-header\fP. Providing \fI\-\-location\-trusted\fP multiple times has no extra effect. Disable it again with \-\-no-location-trusted. Examples: .nf curl --location-trusted -u user:password https://example.com curl --location-trusted -H "Cookie: session=abc" https://example.com .fi See also \fI\-\-user\fP and \fI\-\-follow\fP. .IP "\-\-login\-options <options>" (IMAP LDAP POP3 SMTP) Specify the login options to use during server authentication. You can use login options to specify protocol specific options that may be used during authentication. At present only IMAP, POP3 and SMTP support login options. For more information about login options please see RFC 2384, RFC 5092 and the IETF draft https://datatracker.ietf.org/doc/html/draft\-earhart\-url\-smtp\-00 Since 8.2.0, IMAP supports the login option "AUTH=+LOGIN". With this option, curl uses the plain (not SASL) "LOGIN IMAP" command even if the server advertises SASL authentication. Care should be taken in using this option, as it sends your password over the network in plain text. This does not work if the IMAP server disables the plain "LOGIN" (e.g. to prevent password snooping). If \fI\-\-login\-options\fP is provided several times, the last set value is used. Example: .nf curl --login-options 'AUTH=*' imap://example.com .fi See also \fI\-\-user\fP. .IP "\-\-mail\-auth <address>" (SMTP) Specify a single address. This is used to specify the authentication address (identity) of a submitted message that is being relayed to another server. If \fI\-\-mail\-auth\fP is provided several times, the last set value is used. Example: .nf curl --mail-auth user@example.com -T mail smtp://example.com/ .fi See also \fI\-\-mail\-rcpt\fP and \fI\-\-mail\-from\fP. .IP "\-\-mail\-from <address>" (SMTP) Specify a single address that the given mail should get sent from. If \fI\-\-mail\-from\fP is provided several times, the last set value is used. Example: .nf curl --mail-from user@example.com -T mail smtp://example.com/ .fi See also \fI\-\-mail\-rcpt\fP and \fI\-\-mail\-auth\fP. .IP "\-\-mail\-rcpt <address>" (SMTP) Specify a single email address, username or mailing list name. Repeat this option several times to send to multiple recipients. When performing an address verification (\fBVRFY\fP command), the recipient should be specified as the username or username and domain (as per Section 3.5 of RFC 5321). When performing a mailing list expand (EXPN command), the recipient should be specified using the mailing list name, such as "Friends" or "London\-Office". \fI\-\-mail\-rcpt\fP can be used several times in a command line Example: .nf curl --mail-rcpt user@example.net smtp://example.com .fi See also \fI\-\-mail\-rcpt\-allowfails\fP. .IP "\-\-mail\-rcpt\-allowfails" (SMTP) When sending data to multiple recipients, by default curl aborts SMTP conversation if at least one of the recipients causes RCPT TO command to return an error. The default behavior can be changed by passing \fI\-\-mail\-rcpt\-allowfails\fP command\-line option which makes curl ignore errors and proceed with the remaining valid recipients. If all recipients trigger RCPT TO failures and this flag is specified, curl still aborts the SMTP conversation and returns the error received from to the last RCPT TO command. Providing \fI\-\-mail\-rcpt\-allowfails\fP multiple times has no extra effect. Disable it again with \-\-no-mail-rcpt-allowfails. Example: .nf curl --mail-rcpt-allowfails --mail-rcpt dest@example.com smtp://example.com .fi Added in 7.69.0. See also \fI\-\-mail\-rcpt\fP. .IP "\-M, \-\-manual" Manual. Display the huge help text. Example: .nf curl --manual .fi See also \fI\-\-verbose\fP, \fI\-\-libcurl\fP and \fI\-\-trace\fP. .IP "\-\-max\-filesize <bytes>" (FTP HTTP MQTT) When set to a non\-zero value, it specifies the maximum size (in bytes) of a file to download. If the file requested is larger than this value, the transfer does not start and curl returns with exit code 63. Setting the maximum value to zero disables the limit. A unit suffix letter can be used. Appending \(aqk\(aq or \(aqK\(aq counts the number as kilobytes, \(aqm\(aq or \(aqM\(aq makes it megabytes etc. The supported suffixes (k, M, G, T, P) are 1024\-based. Examples: 200K, 3m and 1G. \fBNOTE\fP: before curl 8.4.0, when the file size is not known prior to download, for such files this option has no effect even if the file transfer ends up being larger than this given limit. Starting with curl 8.4.0, this option aborts the transfer if it reaches the threshold during transfer. Starting in curl 8.19.0, the maximum size can be specified using a fraction as in "2.5M" for two and a half megabytes. It only works with a period (".") delimiter, independent of what your locale might prefer. Since 8.20.0, this option also stops ongoing transfers that would reach this threshold due to automatic decompression using \fI\-\-compressed\fP. If \fI\-\-max\-filesize\fP is provided several times, the last set value is used. Examples: .nf curl --max-filesize 100K https://example.com curl --max-filesize 2.6M https://example.com .fi See also \fI\-\-limit\-rate\fP. .IP "\-\-max\-redirs <num>" (HTTP) Set the maximum number of redirections to follow. When \fI\-\-location\fP or \fI\-\-follow\fP are used, this option prevents curl from following too many redirects. By default the limit is set to 50 redirects. Set this option to \-1 to make it unlimited. If \fI\-\-max\-redirs\fP is provided several times, the last set value is used. Example: .nf curl --max-redirs 3 --location https://example.com .fi See also \fI\-\-location\fP and \fI\-\-follow\fP. .IP "\-m, \-\-max\-time <seconds>" Set the maximum time in seconds that you allow each transfer to take. Prevents your batch jobs from hanging for hours due to slow networks or links going down. This option accepts decimal values. If you enable retrying the transfer (\fI\-\-retry\fP) then the maximum time counter is reset each time the transfer is retried. You can use \fI\-\-retry\-max\-time\fP to limit the retry time. The decimal value needs to be provided using a dot (.) as decimal separator \- not the local version even if it might be using another separator. If \fI\-\-max\-time\fP is provided several times, the last set value is used. Examples: .nf curl --max-time 10 https://example.com curl --max-time 2.92 https://example.com .fi See also \fI\-\-connect\-timeout\fP and \fI\-\-retry\-max\-time\fP. .IP "\-\-metalink" This option was previously used to specify a Metalink resource. Metalink support is disabled in curl for security reasons (added in 7.78.0). If \fI\-\-metalink\fP is provided several times, the last set value is used. Example: .nf curl --metalink file https://example.com .fi See also \fI\-\-parallel\fP. .IP "\-\-mptcp" Enable the use of Multipath TCP (MPTCP) for connections. MPTCP is an extension to the standard TCP that allows multiple TCP streams over different network paths between the same source and destination. This can enhance bandwidth and improve reliability by using multiple paths simultaneously. MPTCP is beneficial in networks where multiple paths exist between clients and servers, such as mobile networks where a device may switch between WiFi and cellular data or in wired networks with multiple Internet Service Providers. This option is currently only supported on Linux starting from kernel 5.6. Only TCP connections are modified, hence this option does not affect HTTP/3 (QUIC) or UDP connections. The server curl connects to must also support MPTCP. If not, the connection seamlessly falls back to TCP. Providing \fI\-\-mptcp\fP multiple times has no extra effect. Disable it again with \-\-no-mptcp. Example: .nf curl --mptcp https://example.com .fi Added in 8.9.0. See also \fI\-\-tcp\-fastopen\fP. .IP "\-\-negotiate" (HTTP) Enable Negotiate (SPNEGO) authentication. This option requires a library built with GSS\-API or SSPI support. Use \fI\-\-version\fP to see if your curl supports GSS\-API/SSPI or SPNEGO. When using this option, you must also provide a fake \fI\-\-user\fP option to activate the authentication code properly. Sending a \(aq\-u :\(aq is enough as the username and password from the \fI\-\-user\fP option are not actually used. Providing \fI\-\-negotiate\fP multiple times has no extra effect. Disable it again with \-\-no-negotiate. Example: .nf curl --negotiate -u : https://example.com .fi See also \fI\-\-basic\fP, \fI\-\-ntlm\fP, \fI\-\-anyauth\fP and \fI\-\-proxy\-negotiate\fP. .IP "\-n, \-\-netrc" Make curl scan the \fI.netrc\fP file in the user\(aqs home directory for login name and password. This is typically used for FTP on Unix. If used with HTTP, curl enables user authentication. See \fInetrc(5)\fP and \fIftp(1)\fP for details on the file format. curl does not complain if that file does not have the right permissions (it should be neither world\- nor group\-readable). The environment variable "HOME" is used to find the home directory. If the "NETRC" environment variable is set, that filename is used as the netrc file. (Added in 8.16.0) If \fI\-\-netrc\-file\fP is used, that overrides all other ways to figure out the file. The netrc file provides credentials for a hostname independent of which protocol and port number that are used. On Windows two filenames in the home directory are checked: \fI.netrc\fP and \fI_netrc\fP, preferring the former. Older versions on Windows checked for \fI_netrc\fP only. A quick and simple example of how to setup a \fI.netrc\fP to allow curl to access the machine host.example.com with username "myself" and password "secret" could look similar to: .nf machine host.example.com login myself password secret .fi curl also supports the "default" keyword. This is the same as machine name except that default matches any name. There can be only one "default" token, and it must be after all machine tokens. When providing a username in the URL and a \fI.netrc\fP file, curl looks for the password for that specific user for the given host if such an entry appears in the file before a "generic" "machine" entry without "login" specified. Providing \fI\-\-netrc\fP multiple times has no extra effect. Disable it again with \-\-no-netrc. Example: .nf curl --netrc https://example.com .fi This option is mutually exclusive with \fI\-\-netrc\-file\fP and \fI\-\-netrc\-optional\fP. See also \fI\-\-netrc\-file\fP, \fI\-\-config\fP and \fI\-\-user\fP. .IP "\-\-netrc\-file <filename>" Set the netrc file to use. Similar to \fI\-\-netrc\fP, except that you also provide the path (absolute or relative). It abides by \fI\-\-netrc\-optional\fP if specified. If \fI\-\-netrc\-file\fP is provided several times, the last set value is used. Example: .nf curl --netrc-file netrc https://example.com .fi This option is mutually exclusive with \fI\-\-netrc\fP. See also \fI\-\-netrc\fP, \fI\-\-user\fP and \fI\-\-config\fP. .IP "\-\-netrc\-optional" Similar to \fI\-\-netrc\fP, but this option makes the .netrc usage \fBoptional\fP and not mandatory as the \fI\-\-netrc\fP option does. Providing \fI\-\-netrc\-optional\fP multiple times has no extra effect. Disable it again with \-\-no-netrc-optional. Example: .nf curl --netrc-optional https://example.com .fi This option is mutually exclusive with \fI\-\-netrc\fP. See also \fI\-\-netrc\-file\fP. .IP "\-:, \-\-next" Use a separate operation for the following URL and associated options. This allows you to send several URL requests, each with their own specific options, for example, such as different usernames or custom requests for each. \fI\-\-next\fP resets all local options and only global ones have their values survive over to the operation following the \fI\-\-next\fP instruction. Global options include \fI\-\-verbose\fP, \fI\-\-trace\fP, \fI\-\-trace\-ascii\fP and \fI\-\-fail\-early\fP. For example, you can do both a GET and a POST in a single command line: .nf curl www1.example.com \--next \-d postthis www2.example.com .fi \fI\-\-next\fP can be used several times in a command line Examples: .nf curl https://example.com --next -d postthis www2.example.com curl -I https://example.com --next https://example.net/ .fi See also \fI\-\-parallel\fP and \fI\-\-config\fP. .IP "\-\-no\-alpn" (HTTPS) Disable the ALPN TLS extension. ALPN is enabled by default if libcurl was built with an SSL library that supports ALPN. ALPN is used by a libcurl that supports HTTP/2 to negotiate HTTP/2 support with the server during https sessions. Note that this is the negated option name documented. You can use \fI\-\-alpn\fP to enable ALPN. Providing \fI\-\-no\-alpn\fP multiple times has no extra effect. Disable it again with \-\-alpn. Example: .nf curl --no-alpn https://example.com .fi For \fI\-\-no\-alpn\fP to work, it requires that the underlying libcurl is built to support TLS. See also \fI\-\-no\-npn\fP and \fI\-\-http2\fP. .IP "\-N, \-\-no\-buffer" Disable the buffering of the output stream. In normal work situations, curl uses a standard buffered output stream that has the effect that it outputs the data in chunks, not necessarily exactly when the data arrives. Using this option disables that buffering. Note that this is the negated option name documented. You can use \fI\-\-buffer\fP to enable buffering again. Providing \fI\-\-no\-buffer\fP multiple times has no extra effect. Disable it again with \-\-buffer. Example: .nf curl --no-buffer https://example.com .fi See also \fI\-\-progress\-bar\fP. .IP "\-\-no\-clobber" When used in conjunction with the \fI\-\-output\fP, \fI\-\-remote\-header\-name\fP, \fI\-\-remote\-name\fP, or \fI\-\-remote\-name\-all\fP options, curl avoids overwriting files that already exist. Instead, a dot and a number gets appended to the name of the file that would be created, up to filename.100 after which it does not create any file. Note that this is the negated option name documented. You can thus use \fI\-\-clobber\fP to enforce the clobbering, even if \fI\-\-remote\-header\-name\fP is specified. The \fI\-\-continue\-at\fP option cannot be used together with \fI\-\-no\-clobber\fP. Providing \fI\-\-no\-clobber\fP multiple times has no extra effect. Disable it again with \-\-clobber. Example: .nf curl --no-clobber --output local/dir/file https://example.com .fi Added in 7.83.0. See also \fI\-\-output\fP and \fI\-\-remote\-name\fP. .IP "\-\-no\-keepalive" Disable the use of keepalive messages on the TCP connection. curl otherwise enables them by default. Note that this is the negated option name documented. You can thus use \fI\-\-keepalive\fP to enforce keepalive. Providing \fI\-\-no\-keepalive\fP multiple times has no extra effect. Disable it again with \-\-keepalive. Example: .nf curl --no-keepalive https://example.com .fi See also \fI\-\-keepalive\-time\fP and \fI\-\-keepalive\-cnt\fP. .IP "\-\-no\-npn" (HTTPS) curl never uses NPN, this option has no effect (added in 7.86.0). Disable the NPN TLS extension. NPN is enabled by default if libcurl was built with an SSL library that supports NPN. NPN is used by a libcurl that supports HTTP/2 to negotiate HTTP/2 support with the server during https sessions. Providing \fI\-\-no\-npn\fP multiple times has no extra effect. Disable it again with \-\-npn. Example: .nf curl --no-npn https://example.com .fi For \fI\-\-no\-npn\fP to work, it requires that the underlying libcurl is built to support TLS. See also \fI\-\-no\-alpn\fP and \fI\-\-http2\fP. .IP "\-\-no\-progress\-meter" Option to switch off the progress meter output without muting or otherwise affecting warning and informational messages like \fI\-\-silent\fP does. Note that this is the negated option name documented. You can thus use \fI\-\-progress\-meter\fP to enable the progress meter again. Providing \fI\-\-no\-progress\-meter\fP multiple times has no extra effect. Disable it again with \-\-progress-meter. Example: .nf curl --no-progress-meter -o store https://example.com .fi Added in 7.67.0. See also \fI\-\-verbose\fP and \fI\-\-silent\fP. .IP "\-\-no\-sessionid" (TLS) Disable curl\(aqs use of SSL session\-ID caching. By default all transfers are done using the cache. Note that while nothing should ever get hurt by attempting to reuse SSL session\-IDs, there seem to be broken SSL implementations in the wild that may require you to disable this in order for you to succeed. Note that this is the negated option name documented. You can thus use \fI\-\-sessionid\fP to enforce session\-ID caching. Providing \fI\-\-no\-sessionid\fP multiple times has no extra effect. Disable it again with \-\-sessionid. Example: .nf curl --no-sessionid https://example.com .fi See also \fI\-\-insecure\fP. .IP "\-\-noproxy <no\-proxy\-list>" Comma\-separated list of hosts for which not to use a proxy, if one is specified. The only wildcard is a single "*" character, which matches all hosts, and effectively disables the proxy. Each name in this list is matched as either a domain which contains the hostname, or the hostname itself. For example, "local.com" would match "local.com", "local.com:80", and \&"www.local.com", but not "www.notlocal.com". To use international hostnames in this list, add the punycode version of the hostname. This option overrides the environment variables that disable the proxy ("no_proxy" and "NO_PROXY"). If there is an environment variable disabling a proxy, you can set the no proxy list to "" to override it. IP addresses specified to this option can be provided using CIDR notation (added in 7.86.0): an appended slash and number specifies the number of network bits out of the address to use in the comparison. For example \&"192.168.0.0/16" would match all addresses starting with "192.168". If \fI\-\-noproxy\fP is provided several times, the last set value is used. Example: .nf curl --noproxy "www.example" https://example.com .fi See also \fI\-\-proxy\fP. .IP "\-\-ntlm" (HTTP) Use NTLM authentication. The NTLM authentication method was designed by Microsoft and is used by IIS web servers. It is a proprietary protocol, reverse\-engineered by clever people and implemented in curl based on their efforts. This kind of behavior should not be endorsed, you should encourage everyone who uses NTLM to switch to a public and documented authentication method instead, such as Digest. If you want to enable NTLM for your proxy authentication, then use \fI\-\-proxy\-ntlm\fP. Providing \fI\-\-ntlm\fP multiple times has no extra effect. Disable it again with \-\-no-ntlm. Example: .nf curl --ntlm -u user:password https://example.com .fi For \fI\-\-ntlm\fP to work, it requires that the underlying libcurl is built to support TLS. See also \fI\-\-proxy\-ntlm\fP. .IP "\-\-ntlm\-wb" (HTTP) Deprecated option (added in 8.8.0). Enabled NTLM much in the style \fI\-\-ntlm\fP does, but handed over the authentication to a separate executable that was executed when needed. Providing \fI\-\-ntlm\-wb\fP multiple times has no extra effect. Example: .nf curl --ntlm-wb -u user:password https://example.com .fi See also \fI\-\-ntlm\fP and \fI\-\-proxy\-ntlm\fP. .IP "\-\-oauth2\-bearer <token>" (IMAP LDAP POP3 SMTP HTTP) Specify the Bearer Token for OAUTH 2.0 server authentication. The Bearer Token is used in conjunction with the username which can be specified as part of the \fI\-\-url\fP or \fI\-\-user\fP options. The Bearer Token and username are formatted according to RFC 6750. If \fI\-\-oauth2\-bearer\fP is provided several times, the last set value is used. Example: .nf curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com .fi See also \fI\-\-basic\fP, \fI\-\-ntlm\fP and \fI\-\-digest\fP. .IP "\-\-out\-null" Discard all response output of a transfer silently. This is the more efficient and portable version of .nf curl https://host.example \-o /dev/null .fi The transfer is done in full, all data is received and checked, but the bytes are not written anywhere. \fI\-\-out\-null\fP is associated with a single URL. Use it once per URL when you use several URLs in a command line. Example: .nf curl "https://example.com" --out-null .fi Added in 8.16.0. See also \fI\-\-output\fP, \fI\-\-remote\-name\fP, \fI\-\-remote\-name\-all\fP and \fI\-\-remote\-header\-name\fP. .IP "\-o, \-\-output <file>" Write output to the given file instead of stdout. If you are using globbing to fetch multiple documents, you should quote the URL and you can use "#" followed by a number in the filename. That variable is then replaced with the current string for the URL being fetched. Like in: .nf curl "http://{one,two}.example.com" \-o "file_#1.txt" .fi or use several variables like: .nf curl "http://{site,host}.host[1\-5].example" \-o "#1_#2" .fi You may use this option as many times as the number of URLs you have. For example, if you specify two URLs on the same command line, you can use it like this: .nf curl \-o aa example.com \-o bb example.net .fi and the order of the \-o options and the URLs does not matter, only that the first \-o is for the first URL and so on, so the above command line can also be written as .nf curl example.com example.net \-o aa \-o bb .fi See also the \fI\-\-create\-dirs\fP option to create the local directories dynamically. Specifying the output as \(aq\-\(aq (a single dash) passes the output to stdout. To suppress response bodies, you can redirect output to /dev/null: .nf curl example.com \-o /dev/null .fi Or for Windows: .nf curl example.com \-o nul .fi Or, even more efficient and portable, use .nf curl example.com \--out\-null .fi Specify the filename as single minus to force the output to stdout, to override curl\(aqs internal binary output in terminal prevention: .nf curl https://example.com/jpeg \-o \- .fi Note that the binary output may be caused by the response being compressed, in which case you may want to use the \fI\-\-compressed\fP option. \fI\-\-output\fP is associated with a single URL. Use it once per URL when you use several URLs in a command line. Examples: .nf curl -o file https://example.com curl "http://{one,two}.example.com" -o "file_#1.txt" curl "http://{site,host}.host[1-5].example" -o "#1_#2" curl -o file https://example.com -o file2 https://example.net .fi See also \fI\-\-out\-null\fP, \fI\-\-remote\-name\fP, \fI\-\-remote\-name\-all\fP, \fI\-\-remote\-header\-name\fP and \fI\-\-compressed\fP. .IP "\-\-output\-dir <dir>" Specify the directory in which files should be stored, when \fI\-\-remote\-name\fP or \fI\-\-output\fP are used. The given output directory is used for all URLs and output options on the command line, up until the first \fI\-\-next\fP. If the specified target directory does not exist, the operation fails unless \fI\-\-create\-dirs\fP is also used. If \fI\-\-output\-dir\fP is provided several times, the last set value is used. Example: .nf curl --output-dir "tmp" -O https://example.com .fi Added in 7.73.0. See also \fI\-\-remote\-name\fP and \fI\-\-remote\-header\-name\fP. .IP "\-Z, \-\-parallel" Make curl perform all transfers in parallel as compared to the regular serial manner. Parallel transfer means that curl runs up to N concurrent transfers simultaneously and if there are more than N transfers to handle, it starts new ones when earlier transfers finish. With parallel transfers, the progress meter output is different from when doing serial transfers, as it then displays the transfer status for multiple transfers in a single line. The maximum amount of concurrent transfers is set with \fI\-\-parallel\-max\fP and it defaults to 50. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-parallel\fP multiple times has no extra effect. Disable it again with \-\-no-parallel. Example: .nf curl --parallel https://example.com -o file1 https://example.com -o file2 .fi Added in 7.66.0. See also \fI\-\-next\fP, \fI\-\-verbose\fP, \fI\-\-parallel\-max\fP and \fI\-\-parallel\-immediate\fP. .IP "\-\-parallel\-immediate" When doing parallel transfers, this option instructs curl to prefer opening up more connections in parallel at once rather than waiting to see if new transfers can be added as multiplexed streams on another connection. By default, without this option set, curl prefers to wait a little and multiplex new transfers over existing connections. It keeps the number of connections low at the expense of risking a slightly slower transfer startup. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-parallel\-immediate\fP multiple times has no extra effect. Disable it again with \-\-no-parallel-immediate. Example: .nf curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2 .fi Added in 7.68.0. See also \fI\-\-parallel\fP and \fI\-\-parallel\-max\fP. .IP "\-\-parallel\-max <num>" When asked to do parallel transfers, using \fI\-\-parallel\fP, this option controls the maximum amount of transfers to do simultaneously. The default is 50. 65535 is the largest supported value. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-parallel\-max\fP is provided several times, the last set value is used. Example: .nf curl --parallel-max 100 -Z https://example.com ftp://example.com/ .fi Added in 7.66.0. See also \fI\-\-parallel\fP and \fI\-\-parallel\-max\-host\fP. .IP "\-\-parallel\-max\-host <num>" When asked to do parallel transfers, using \fI\-\-parallel\fP, this option controls the maximum amount of concurrent connections curl is allowed to do to the same protocol + hostname + port number target. The limit is enforced by libcurl and queued "internally", which means that transfers that are waiting for an available connection still look like started transfers in the progress meter. The default is 0 (unlimited). 65535 is the largest supported value. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-parallel\-max\-host\fP is provided several times, the last set value is used. Example: .nf curl --parallel-max-host 5 -Z https://example.com ftp://example.com/ .fi Added in 8.16.0. See also \fI\-\-parallel\fP and \fI\-\-parallel\-max\fP. .IP "\-\-pass <phrase>" (TLS SCP SFTP) Passphrase for the private key used for SSH or TLS. If \fI\-\-pass\fP is provided several times, the last set value is used. Example: .nf curl --pass secret --key file https://example.com .fi See also \fI\-\-key\fP and \fI\-\-user\fP. .IP "\-\-path\-as\-is" Do not handle sequences of /../ or /./ in the given URL path. Normally curl squashes or merges them according to standards but with this option set you tell it not to do that. Providing \fI\-\-path\-as\-is\fP multiple times has no extra effect. Disable it again with \-\-no-path-as-is. Example: .nf curl --path-as-is https://example.com/../../etc/passwd .fi See also \fI\-\-request\-target\fP. .IP "\-\-pinnedpubkey <hashes>" (TLS) Use the specified public key file (or hashes) to verify the peer. This can be a path to a file which contains a single public key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by \(aqsha256//\(aq and separated by \(aq;\(aq. When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this certificate and if it does not exactly match the public key provided to this option, curl aborts the connection before sending or receiving any data. This option is independent of option \fI\-\-insecure\fP. If you use both options together then the peer is still verified by public key. PEM/DER support: OpenSSL and GnuTLS, wolfSSL, mbedTLS, Schannel sha256 support: OpenSSL, GnuTLS and wolfSSL, mbedTLS, Schannel Other SSL backends not supported. If \fI\-\-pinnedpubkey\fP is provided several times, the last set value is used. Examples: .nf curl --pinnedpubkey keyfile https://example.com curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com .fi See also \fI\-\-hostpubsha256\fP. .IP "\-\-post301" (HTTP) Respect RFC 7231/6.4.2 and do not convert POST requests into GET requests when following a 301 redirect. The non\-RFC behavior is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. A server may require a POST to remain a POST after such a redirection. This option is meaningful only when using \fI\-\-location\fP. Providing \fI\-\-post301\fP multiple times has no extra effect. Disable it again with \-\-no-post301. Example: .nf curl --post301 --location -d "data" https://example.com .fi See also \fI\-\-post302\fP, \fI\-\-post303\fP and \fI\-\-location\fP. .IP "\-\-post302" (HTTP) Respect RFC 7231/6.4.3 and do not convert POST requests into GET requests when following a 302 redirect. The non\-RFC behavior is ubiquitous in web browsers, so curl does the conversion by default to maintain consistency. A server may require a POST to remain a POST after such a redirection. This option is meaningful only when using \fI\-\-location\fP. Providing \fI\-\-post302\fP multiple times has no extra effect. Disable it again with \-\-no-post302. Example: .nf curl --post302 --location -d "data" https://example.com .fi See also \fI\-\-post301\fP, \fI\-\-post303\fP and \fI\-\-location\fP. .IP "\-\-post303" (HTTP) Violate RFC 7231/6.4.4 and do not convert POST requests into GET requests when following 303 redirect. A server may require a POST to remain a POST after a 303 redirection. This option is meaningful only when using \fI\-\-location\fP. Providing \fI\-\-post303\fP multiple times has no extra effect. Disable it again with \-\-no-post303. Example: .nf curl --post303 --location -d "data" https://example.com .fi See also \fI\-\-post302\fP, \fI\-\-post301\fP and \fI\-\-location\fP. .IP "\-\-preproxy <[protocol://]host[:port]>" Use the specified SOCKS proxy before connecting to an HTTP or HTTPS \fI\-\-proxy\fP. In such a case curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. Hence pre proxy. The pre proxy string should be specified with a protocol:// prefix to specify alternative proxy protocols. Use socks4://, socks4a://, socks5:// or socks5h:// to request the specific SOCKS version to be used. No protocol specified makes curl default to SOCKS4. If the port number is not specified in the proxy string, it is assumed to be 1080. User and password that might be provided in the proxy string are URL decoded by curl. This allows you to pass in special characters such as @ by using %40 or pass in a colon with %3a. If \fI\-\-preproxy\fP is provided several times, the last set value is used. Example: .nf curl --preproxy socks5://proxy.example -x http://http.example https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-socks5\fP. .IP "\-#, \-\-progress\-bar" Make curl display transfer progress as a simple progress bar instead of the standard, more informational, meter. This progress bar draws a single line of \(aq#\(aq characters across the screen and shows a percentage if the transfer size is known. For transfers without a known size, there is a space ship (\-=o=\-) that moves back and forth but only while data is being transferred, with a set of flying hash sign symbols on top. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-progress\-bar\fP multiple times has no extra effect. Disable it again with \-\-no-progress-bar. Example: .nf curl -# -O https://example.com .fi See also \fI\-\-styled\-output\fP. .IP "\-\-proto <protocols>" Limit what protocols to allow for transfers. Protocols are evaluated left to right, are comma separated, and are each a protocol name or \(aqall\(aq, optionally prefixed by zero or more modifiers. Available modifiers are: .RS .IP + Permit this protocol in addition to protocols already permitted (this is the default if no modifier is used). .IP - Deny this protocol, removing it from the list of protocols already permitted. .IP = Permit only this protocol (ignoring the list already permitted), though subject to later modification by subsequent entries in the comma separated list. .RE .IP For example: \fI\-\-proto\fP \-ftps uses the default protocols, but disables ftps \fI\-\-proto\fP \-all,https,+http only enables http and https \fI\-\-proto\fP =http,https also only enables http and https Unknown and disabled protocols produce a warning. This allows scripts to safely rely on being able to disable potentially dangerous protocols, without relying upon support for that protocol being built into curl to avoid an error. This option can be used multiple times, in which case the effect is the same as concatenating the protocols into one instance of the option. If \fI\-\-proto\fP is provided several times, the last set value is used. Example: .nf curl --proto =http,https,sftp https://example.com .fi See also \fI\-\-proto\-redir\fP and \fI\-\-proto\-default\fP. .IP "\-\-proto\-default <protocol>" Use \fIprotocol\fP for any provided URL missing a scheme. An unknown or unsupported protocol causes error \fICURLE_UNSUPPORTED_PROTOCOL\fP. This option does not change the default proxy protocol (http). Without this option set, curl guesses protocol based on the hostname, see \fI\-\-url\fP for details. If \fI\-\-proto\-default\fP is provided several times, the last set value is used. Example: .nf curl --proto-default https ftp.example.com .fi See also \fI\-\-proto\fP and \fI\-\-proto\-redir\fP. .IP "\-\-proto\-redir <protocols>" Limit what protocols to allow on redirects. Protocols denied by \fI\-\-proto\fP are not overridden by this option. See \fI\-\-proto\fP for how protocols are represented. Example, allow only HTTP and HTTPS on redirect: .nf curl \--proto\-redir \-all,http,https \--follow http://example.com .fi By default curl only allows HTTP, HTTPS, FTP and FTPS on redirects \&. Specifying \fIall\fP or \fI+all\fP enables all protocols on redirects, which is not good for security. If \fI\-\-proto\-redir\fP is provided several times, the last set value is used. Example: .nf curl --proto-redir =http,https --follow https://example.com .fi See also \fI\-\-proto\fP and \fI\-\-follow\fP. .IP "\-x, \-\-proxy <[protocol://]host[:port]>" Use the specified proxy. The proxy string can be specified with a protocol:// prefix. No protocol specified or http:// it is treated as an HTTP proxy. Use socks4://, socks4a://, socks5:// or socks5h:// to request a specific SOCKS version to be used. Unix domain sockets are supported for socks proxy. Set localhost for the host part. e.g. socks5h://localhost/path/to/socket.sock HTTPS proxy support works with the https:// protocol prefix for OpenSSL and GnuTLS. It also works for mbedTLS, Rustls, Schannel and wolfSSL (added in 7.87.0). Unrecognized and unsupported proxy protocol schemes cause an error. If the port number is not specified in the proxy string, it is assumed to be 1080. This option overrides existing environment variables that set the proxy to use. If there is an environment variable setting a proxy, you can set proxy to \&"" to override it. All operations that are performed over an HTTP proxy are transparently converted to HTTP. It means that certain protocol specific operations might not be available. This is not the case if you can tunnel through the proxy, as one with the \fI\-\-proxytunnel\fP option. User and password that might be provided in the proxy string are URL decoded by curl. This allows you to pass in special characters such as @ by using %40 or pass in a colon with %3a. The proxy host can be specified the same way as the proxy environment variables, including the protocol prefix (http://) and the embedded user + password. When a proxy is used, the active FTP mode as set with \fI\-\-ftp\-port\fP, cannot be used. Doing FTP over an HTTP proxy without \fI\-\-proxytunnel\fP makes curl do HTTP with an FTP URL over the proxy. For such transfers, common FTP specific options do not work, including \fI\-\-ssl\-reqd\fP and \fI\-\-ftp\-ssl\-control\fP. If \fI\-\-proxy\fP is provided several times, the last set value is used. Example: .nf curl --proxy http://proxy.example https://example.com .fi See also \fI\-\-socks5\fP and \fI\-\-proxy\-basic\fP. .IP "\-\-proxy\-anyauth" Automatically pick a suitable authentication method when communicating with the given HTTP proxy. This might cause an extra request/response round\-trip. Example: .nf curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-proxy\-basic\fP and \fI\-\-proxy\-digest\fP. .IP "\-\-proxy\-basic" Use HTTP Basic authentication when communicating with the given proxy. Use \fI\-\-basic\fP for enabling HTTP Basic with a remote host. Basic is the default authentication method curl uses with proxies. Providing \fI\-\-proxy\-basic\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-basic. Example: .nf curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-proxy\-anyauth\fP and \fI\-\-proxy\-digest\fP. .IP "\-\-proxy\-ca\-native" (TLS) Use the operating system\(aqs native CA store for certificate verification of the HTTPS proxy. This option is independent of other HTTPS proxy CA certificate locations set at run time or build time. Those locations are searched in addition to the native CA store. Equivalent to \fI\-\-ca\-native\fP but used in HTTPS proxy context. Refer to \fI\-\-ca\-native\fP for TLS backend limitations. Providing \fI\-\-proxy\-ca\-native\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-ca-native. Example: .nf curl --proxy-ca-native https://example.com .fi Added in 8.2.0. See also \fI\-\-ca\-native\fP, \fI\-\-cacert\fP, \fI\-\-capath\fP, \fI\-\-dump\-ca\-embed\fP and \fI\-\-insecure\fP. .IP "\-\-proxy\-cacert <file>" Use the specified certificate file to verify the HTTPS proxy. The file may contain multiple CA certificates. The certificate(s) must be in PEM format. This allows you to use a different trust for the proxy compared to the remote server connected to via the proxy. Equivalent to \fI\-\-cacert\fP but used in HTTPS proxy context. If \fI\-\-proxy\-cacert\fP is provided several times, the last set value is used. Example: .nf curl --proxy-cacert CA-file.txt -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-capath\fP, \fI\-\-cacert\fP, \fI\-\-capath\fP, \fI\-\-dump\-ca\-embed\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-capath <dir>" Same as \fI\-\-capath\fP but used in HTTPS proxy context. Use the specified certificate directory to verify the proxy. Multiple paths can be provided by separating them with colon (":") (e.g. "path1:path2:path3"). The certificates must be in PEM format, and if curl is built against OpenSSL, the directory must have been processed using the c_rehash utility supplied with OpenSSL. Using \fI\-\-proxy\-capath\fP can allow OpenSSL\-powered curl to make SSL\-connections much more efficiently than using \fI\-\-proxy\-cacert\fP if the \fI\-\-proxy\-cacert\fP file contains many CA certificates. If this option is set, the default capath value is ignored. If \fI\-\-proxy\-capath\fP is provided several times, the last set value is used. Example: .nf curl --proxy-capath /local/directory -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-cacert\fP, \fI\-\-proxy\fP, \fI\-\-capath\fP and \fI\-\-dump\-ca\-embed\fP. .IP "\-\-proxy\-cert <cert[:passwd]>" Use the specified client certificate file when communicating with an HTTPS proxy. The certificate must be PEM format. If the optional password is not specified, it is queried for on the terminal. Use \fI\-\-proxy\-key\fP to provide the private key. This option is the equivalent to \fI\-\-cert\fP but used in HTTPS proxy context. If \fI\-\-proxy\-cert\fP is provided several times, the last set value is used. Example: .nf curl --proxy-cert file -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-proxy\-key\fP and \fI\-\-proxy\-cert\-type\fP. .IP "\-\-proxy\-cert\-type <type>" Set type of the provided client certificate when using HTTPS proxy. PEM, DER, ENG, PROV and P12 are recognized types. The default type depends on the TLS backend and is usually PEM. For Schannel it is P12. If \fI\-\-proxy\-cert\fP is a pkcs11: URI then ENG or PROV is the default type (depending on OpenSSL version). Equivalent to \fI\-\-cert\-type\fP but used in HTTPS proxy context. If \fI\-\-proxy\-cert\-type\fP is provided several times, the last set value is used. Example: .nf curl --proxy-cert-type PEM --proxy-cert file -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-cert\fP and \fI\-\-proxy\-key\fP. .IP "\-\-proxy\-ciphers <list>" (TLS) Same as \fI\-\-ciphers\fP but used in HTTPS proxy context. Specify which cipher suites to use in the connection to your HTTPS proxy when it negotiates TLS 1.2 (1.1, 1.0). The list of ciphers suites must specify valid ciphers. Read up on cipher suite details on this URL: https://curl.se/docs/ssl\-ciphers.html If \fI\-\-proxy\-ciphers\fP is provided several times, the last set value is used. Example: .nf curl --proxy-ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256 -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-tls13\-ciphers\fP, \fI\-\-ciphers\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-crlfile <file>" Provide filename for a PEM formatted file with a Certificate Revocation List that specifies peer certificates that are considered revoked when communicating with an HTTPS proxy. Equivalent to \fI\-\-crlfile\fP but only used in HTTPS proxy context. If \fI\-\-proxy\-crlfile\fP is provided several times, the last set value is used. Example: .nf curl --proxy-crlfile rejects.txt -x https://proxy.example https://example.com .fi See also \fI\-\-crlfile\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-digest" Use HTTP Digest authentication when communicating with the given proxy. Use \fI\-\-digest\fP for enabling HTTP Digest with a remote host. Providing \fI\-\-proxy\-digest\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-digest. Example: .nf curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-proxy\-anyauth\fP and \fI\-\-proxy\-basic\fP. .IP "\-\-proxy\-header <header/@file>" (HTTP) Extra header to include in the request when sending HTTP to a proxy. You may specify any number of extra headers. This is the equivalent option to \fI\-\-header\fP but is for proxy communication only like in CONNECT requests when you want a separate header sent to the proxy to what is sent to the actual remote host. curl makes sure that each header you add/replace is sent with the proper end\-of\-line marker, you should thus \fBnot\fP add that as a part of the header content: do not add newlines or carriage returns, they only mess things up for you. Headers specified with this option are not included in requests that curl knows are not to be sent to a proxy. This option can take an argument in @filename style, which then adds a header for each line in the input file. Using @\- makes curl read the headers from stdin. This option can be used multiple times to add/replace/remove multiple headers. \fI\-\-proxy\-header\fP can be used several times in a command line Examples: .nf curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com curl --proxy-header "User-Agent: surprise" -x http://proxy https://example.com curl --proxy-header "Host:" -x http://proxy https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-header\fP. .IP "\-\-proxy\-http2" (HTTP) Negotiate HTTP/2 with an HTTPS proxy. The proxy might still only offer HTTP/1 and then curl sticks to using that version. This has no effect for any other kinds of proxies. Providing \fI\-\-proxy\-http2\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-http2. Example: .nf curl --proxy-http2 -x proxy https://example.com .fi For \fI\-\-proxy\-http2\fP to work, it requires that the underlying libcurl is built to support HTTP/2. Added in 8.1.0. See also \fI\-\-proxy\fP. .IP "\-\-proxy\-insecure" Same as \fI\-\-insecure\fP but used in HTTPS proxy context. Every secure connection curl makes is verified to be secure before the transfer takes place. This option makes curl skip the verification step with a proxy and proceed without checking. When this option is not used for a proxy using HTTPS, curl verifies the proxy\(aqs TLS certificate before it continues: that the certificate contains the right name which matches the hostname and that the certificate has been signed by a CA certificate present in the cert store. See this online resource for further details: \fBhttps://curl.se/docs/sslcerts.html\fP \fBWARNING\fP: using this option makes the transfer to the proxy insecure. Providing \fI\-\-proxy\-insecure\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-insecure. Example: .nf curl --proxy-insecure -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-insecure\fP. .IP "\-\-proxy\-key <key>" Specify the filename for your private key when using client certificates with your HTTPS proxy. This option is the equivalent to \fI\-\-key\fP but used in HTTPS proxy context. If \fI\-\-proxy\-key\fP is provided several times, the last set value is used. Example: .nf curl --proxy-key here -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-key\-type\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-key\-type <type>" Specify the private key file type your \fI\-\-proxy\-key\fP provided private key uses. DER, PEM, and ENG are supported. If not specified, PEM is assumed. Equivalent to \fI\-\-key\-type\fP but used in HTTPS proxy context. If \fI\-\-proxy\-key\-type\fP is provided several times, the last set value is used. Example: .nf curl --proxy-key-type DER --proxy-key here -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\-key\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-negotiate" Use HTTP Negotiate (SPNEGO) authentication when communicating with the given proxy. Use \fI\-\-negotiate\fP for enabling HTTP Negotiate (SPNEGO) with a remote host. Providing \fI\-\-proxy\-negotiate\fP multiple times has no extra effect. Example: .nf curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com .fi See also \fI\-\-proxy\-anyauth\fP, \fI\-\-proxy\-basic\fP and \fI\-\-proxy\-service\-name\fP. .IP "\-\-proxy\-ntlm" Use HTTP NTLM authentication when communicating with the given proxy. Use \fI\-\-ntlm\fP for enabling NTLM with a remote host. Providing \fI\-\-proxy\-ntlm\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-ntlm. Example: .nf curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com .fi See also \fI\-\-proxy\-negotiate\fP, \fI\-\-proxy\-anyauth\fP and \fI\-\-proxy\-user\fP. .IP "\-\-proxy\-pass <phrase>" Passphrase for the private key for HTTPS proxy client certificate. Equivalent to \fI\-\-pass\fP but used in HTTPS proxy context. If \fI\-\-proxy\-pass\fP is provided several times, the last set value is used. Example: .nf curl --proxy-pass secret --proxy-key here -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-proxy\-key\fP. .IP "\-\-proxy\-pinnedpubkey <hashes>" (TLS) Use the specified public key file (or hashes) to verify the proxy. This can be a path to a file which contains a single public key in PEM or DER format, or any number of base64 encoded sha256 hashes preceded by \(aqsha256//\(aq and separated by \(aq;\(aq. When negotiating a TLS or SSL connection, the server sends a certificate indicating its identity. A public key is extracted from this certificate and if it does not exactly match the public key provided to this option, curl aborts the connection before sending or receiving any data. Before curl 8.10.0 this option did not work due to a bug. If \fI\-\-proxy\-pinnedpubkey\fP is provided several times, the last set value is used. Examples: .nf curl --proxy-pinnedpubkey keyfile https://example.com curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com .fi See also \fI\-\-pinnedpubkey\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-service\-name <name>" Set the service name for SPNEGO when doing proxy authentication. If \fI\-\-proxy\-service\-name\fP is provided several times, the last set value is used. Example: .nf curl --proxy-service-name "shrubbery" -x proxy https://example.com .fi See also \fI\-\-service\-name\fP, \fI\-\-proxy\fP and \fI\-\-proxy\-negotiate\fP. .IP "\-\-proxy\-ssl\-allow\-beast" Do not work around a security flaw in the TLS1.0 protocol known as BEAST when communicating to an HTTPS proxy. If this option is not used, the TLS layer may use workarounds known to cause interoperability problems with some older server implementations. This option only changes how curl does TLS 1.0 with an HTTPS proxy and has no effect on later TLS versions. \fBWARNING\fP: this option loosens the TLS security, and by using this flag you ask for exactly that. Equivalent to \fI\-\-ssl\-allow\-beast\fP but used in HTTPS proxy context. Providing \fI\-\-proxy\-ssl\-allow\-beast\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-ssl-allow-beast. Example: .nf curl --proxy-ssl-allow-beast -x https://proxy.example https://example.com .fi See also \fI\-\-ssl\-allow\-beast\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-ssl\-auto\-client\-cert" Same as \fI\-\-ssl\-auto\-client\-cert\fP but used in HTTPS proxy context. This is only supported by Schannel. Providing \fI\-\-proxy\-ssl\-auto\-client\-cert\fP multiple times has no extra effect. Disable it again with \-\-no-proxy-ssl-auto-client-cert. Example: .nf curl --proxy-ssl-auto-client-cert -x https://proxy.example https://example.com .fi Added in 7.77.0. See also \fI\-\-ssl\-auto\-client\-cert\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-tls13\-ciphers <list>" (TLS) Same as \fI\-\-tls13\-ciphers\fP but used in HTTPS proxy context. Specify which cipher suites to use in the connection to your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers suites must specify valid ciphers. Read up on TLS 1.3 cipher suite details on this URL: https://curl.se/docs/ssl\-ciphers.html This option is used when curl is built to use OpenSSL 1.1.1 or later, Schannel, wolfSSL, or mbedTLS 3.6.0 or later. Before curl 8.10.0 with mbedTLS or wolfSSL, TLS 1.3 cipher suites were set by using the \fI\-\-proxy\-ciphers\fP option. If \fI\-\-proxy\-tls13\-ciphers\fP is provided several times, the last set value is used. Example: .nf curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com .fi See also \fI\-\-proxy\-ciphers\fP, \fI\-\-tls13\-ciphers\fP and \fI\-\-proxy\fP. .IP "\-\-proxy\-tlsauthtype <type>" Set TLS authentication type with HTTPS proxy. The only supported option is \&"SRP", for TLS\-SRP (RFC 5054). This option works only if the underlying libcurl is built with TLS\-SRP support. Equivalent to \fI\-\-tlsauthtype\fP but used in HTTPS proxy context. If \fI\-\-proxy\-tlsauthtype\fP is provided several times, the last set value is used. Example: .nf curl --proxy-tlsauthtype SRP -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-proxy\-tlsuser\fP and \fI\-\-proxy\-tlspassword\fP. .IP "\-\-proxy\-tlspassword <string>" Set password to use with the TLS authentication method specified with \fI\-\-proxy\-tlsauthtype\fP when using HTTPS proxy. Requires that \fI\-\-proxy\-tlsuser\fP is set. This option does not work with TLS 1.3. Equivalent to \fI\-\-tlspassword\fP but used in HTTPS proxy context. If \fI\-\-proxy\-tlspassword\fP is provided several times, the last set value is used. Example: .nf curl --proxy-tlspassword passwd -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-proxy\-tlsuser\fP. .IP "\-\-proxy\-tlsuser <name>" Set username for use for HTTPS proxy with the TLS authentication method specified with \fI\-\-proxy\-tlsauthtype\fP. Requires that \fI\-\-proxy\-tlspassword\fP also is set. This option does not work with TLS 1.3. If \fI\-\-proxy\-tlsuser\fP is provided several times, the last set value is used. Example: .nf curl --proxy-tlsuser smith -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP and \fI\-\-proxy\-tlspassword\fP. .IP "\-\-proxy\-tlsv1" Use at least TLS version 1.x when negotiating with an HTTPS proxy. That means TLS version 1.0 or higher Equivalent to \fI\-\-tlsv1\fP but for an HTTPS proxy context. Providing \fI\-\-proxy\-tlsv1\fP multiple times has no extra effect. Example: .nf curl --proxy-tlsv1 -x https://proxy.example https://example.com .fi See also \fI\-\-proxy\fP. .IP "\-U, \-\-proxy\-user <user:password>" Specify the username and password to use for proxy authentication. If you use a Windows SSPI\-enabled curl binary and do either Negotiate or NTLM authentication then you can tell curl to select the username and password from your environment by specifying a single colon with this option: "\-U :". On systems where it works, curl hides the given option argument from process listings. This is not enough to protect credentials from possibly getting seen by other users on the same system as they still are visible for a moment before being cleared. Such sensitive data should be retrieved from a file instead or similar and never used in clear text in a command line. If \fI\-\-proxy\-user\fP is provided several times, the last set value is used. Example: .nf curl --proxy-user smith:secret -x proxy https://example.com .fi See also \fI\-\-proxy\-pass\fP. .IP "\-\-proxy1.0 <host[:port]>" Use the specified HTTP 1.0 proxy. If the port number is not specified, it is assumed at port 1080. The only difference between this and the HTTP proxy option \fI\-\-proxy\fP, is that attempts to use CONNECT through the proxy specifies an HTTP 1.0 protocol instead of the default HTTP 1.1. Providing \fI\-\-proxy1.0\fP multiple times has no extra effect. Example: .nf curl --proxy1.0 http://proxy https://example.com .fi See also \fI\-\-proxy\fP, \fI\-\-socks5\fP and \fI\-\-preproxy\fP. .IP "\-p, \-\-proxytunnel" When an HTTP proxy is used \fI\-\-proxy\fP, this option makes curl tunnel the traffic through the proxy. The tunnel approach is made with the HTTP proxy CONNECT request and requires that the proxy allows direct connection to the remote port number curl wants to tunnel through to. To suppress proxy CONNECT response headers when curl is set to output headers use \fI\-\-suppress\-connect\-headers\fP. Providing \fI\-\-proxytunnel\fP multiple times has no extra effect. Disable it again with \-\-no-proxytunnel. Example: .nf curl --proxytunnel -x http://proxy https://example.com .fi See also \fI\-\-proxy\fP. .IP "\-\-pubkey <key>" (SFTP SCP) Public key filename. Allows you to provide your public key in this separate file. curl attempts to automatically extract the public key from the private key file, so passing this option is generally not required. Note that this public key extraction requires libcurl to be linked against a copy of libssh2 1.2.8 or higher that is itself linked against OpenSSL. If \fI\-\-pubkey\fP is provided several times, the last set value is used. Example: .nf curl --pubkey file.pub sftp://example.com/ .fi See also \fI\-\-pass\fP. .IP "\-Q, \-\-quote <command>" (FTP SFTP) Send an arbitrary command to the remote FTP or SFTP server. Quote commands are sent BEFORE the transfer takes place (immediately after the initial \fBPWD\fP command in an FTP transfer, to be exact). To make commands take place after a successful transfer, prefix them with a dash \(aq\-\(aq. (FTP only) To make commands be sent after curl has changed the working directory, immediately before the file transfer command(s), prefix the command with a \(aq+\(aq. You may specify any number of commands. By default curl stops at first failure. To make curl continue even if the command fails, prefix the command with an asterisk (*). Otherwise, if the server returns failure for one of the commands, the entire operation is aborted. You must send syntactically correct FTP commands as RFC 959 defines to FTP servers, or one of the commands listed below to SFTP servers. SFTP is a binary protocol. Unlike for FTP, curl interprets SFTP quote commands itself before sending them to the server. Filenames must be provided within double quotes to embed spaces, backslashes, quotes or double quotes. Within double quotes the following escape sequences are available for that purpose: \\\\, \\", and \\\(aq. Following is the list of all supported SFTP quote commands: .RS .IP "atime date file" The atime command sets the last access time of the file named by the file operand. The date expression can be all sorts of date strings, see the \fIcurl_getdate(3)\fP man page for date expression details. (Added in 7.73.0) .IP "chgrp group file" The chgrp command sets the group ID of the file named by the file operand to the group ID specified by the group operand. The group operand is a decimal integer group ID. .IP "chmod mode file" The chmod command modifies the file mode bits of the specified file. The mode operand is an octal integer mode number. .IP "chown user file" The chown command sets the owner of the file named by the file operand to the user ID specified by the user operand. The user operand is a decimal integer user ID. .IP "ln source_file target_file" The ln and symlink commands create a symbolic link at the target_file location pointing to the source_file location. .IP "mkdir directory_name" The mkdir command creates the directory named by the directory_name operand. .IP "mtime date file" The mtime command sets the last modification time of the file named by the file operand. The date expression can be all sorts of date strings, see the \fIcurl_getdate(3)\fP man page for date expression details. (Added in 7.73.0) .IP pwd The pwd command returns the absolute path name of the current working directory. .IP "rename source target" The rename command renames the file or directory named by the source operand to the destination path named by the target operand. .IP "rm file" The rm command removes the file specified by the file operand. .IP "rmdir directory" The rmdir command removes the directory entry specified by the directory operand, provided it is empty. .IP "symlink source_file target_file" See ln. .RE .IP \fI\-\-quote\fP can be used several times in a command line Example: .nf curl --quote "DELE file" ftp://example.com/foo .fi See also \fI\-\-request\fP. .IP "\-\-random\-file <file>" Deprecated option. This option is ignored (added in 7.84.0). Prior to that it only had an effect on curl if built to use old versions of OpenSSL. Specify the path name to file containing random data. The data may be used to seed the random engine for SSL connections. If \fI\-\-random\-file\fP is provided several times, the last set value is used. Example: .nf curl --random-file rubbish https://example.com .fi See also \fI\-\-egd\-file\fP. .IP "\-r, \-\-range <range>" (HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial document) from an HTTP/1.1, FTP or SFTP server or a local FILE. Ranges can be specified in a number of ways. .RS .IP 0-499 specifies the first 500 bytes .IP 500-999 specifies the second 500 bytes .IP -500 specifies the last 500 bytes .IP 9500- specifies the bytes from offset 9500 and forward .IP 0-0,-1 specifies the first and last byte only(*)(HTTP) .IP 100-199,500-599 specifies two separate 100\-byte ranges(*) (HTTP) .RE .IP (*) = NOTE that if specifying multiple ranges and the server supports it then it replies with a multiple part response that curl returns as\-is. It contains meta information in addition to the requested bytes. Parsing or otherwise transforming this response is the responsibility of the caller. Only digit characters (0\-9) are valid in the \(aqstart\(aq and \(aqstop\(aq fields of the \(aqstart\-stop\(aq range syntax. If a non\-digit character is given in the range, the server\(aqs response is unspecified, depending on the server\(aqs configuration. Many HTTP/1.1 servers do not have this feature enabled, so that when you attempt to get a range, curl instead gets the whole document. FTP and SFTP range downloads only support the simple \(aqstart\-stop\(aq syntax (optionally with one of the numbers omitted). FTP use depends on the extended FTP command SIZE. When using this option for HTTP uploads using POST or PUT, functionality is not guaranteed. The HTTP protocol has no standard interoperable resume upload and curl uses a set of headers for this purpose that once proved working for some servers and have been left for those who find that useful. This command line option is mutually exclusive with \fI\-\-continue\-at\fP: you can only use one of them for a single transfer. If \fI\-\-range\fP is provided several times, the last set value is used. Example: .nf curl --range 22-44 https://example.com .fi See also \fI\-\-continue\-at\fP and \fI\-\-append\fP. .IP "\-\-rate <max request rate>" Specify the maximum transfer frequency you allow curl to use \- in number of transfer starts per time unit (sometimes called request rate). Without this option, curl starts the next transfer as fast as possible. If given several URLs and a transfer completes faster than the allowed rate, curl waits until the next transfer is started to maintain the requested rate. This option has no effect when \fI\-\-parallel\fP is used. The request rate is provided as "N/U" where N is an integer number and U is a time unit. Supported units are \(aqs\(aq (second), \(aqm\(aq (minute), \(aqh\(aq (hour) and \(aqd\(aq /(day, as in a 24 hour unit). The default time unit, if no "/U" is provided, is number of transfers per hour. If curl is told to allow 10 requests per minute, it does not start the next request until 6 seconds have elapsed since the previous transfer was started. This function uses millisecond resolution. If the allowed frequency is set more than 1000 per second, it instead runs unrestricted. When retrying transfers, enabled with \fI\-\-retry\fP, the separate retry delay logic is used and not this setting. Starting in version 8.10.0, you can specify the number of time units in the rate expression. Make curl do no more than 5 transfers per 15 seconds with "5/15s" or limit it to 3 transfers per 4 hours with "3/4h". No spaces allowed. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-rate\fP is provided several times, the last set value is used. Examples: .nf curl --rate 2/s https://example.com ... curl --rate 3/h https://example.com ... curl --rate 14/m https://example.com ... .fi Added in 7.84.0. See also \fI\-\-limit\-rate\fP and \fI\-\-retry\-delay\fP. .IP "\-\-raw" (HTTP) When used, it disables all internal HTTP decoding of content or transfer encodings and instead makes them passed on unaltered, raw. Providing \fI\-\-raw\fP multiple times has no extra effect. Disable it again with \-\-no-raw. Example: .nf curl --raw https://example.com .fi See also \fI\-\-tr\-encoding\fP. .IP "\-e, \-\-referer <URL>" (HTTP) Set the referrer URL in the HTTP request. This can also be set with the \fI\-\-header\fP flag of course. When used with \fI\-\-location\fP you can append ";auto"" to the \fI\-\-referer\fP URL to make curl automatically set the previous URL when it follows a Location: header. The ";auto" string can be used alone, even if you do not set an initial \fI\-\-referer\fP. If \fI\-\-referer\fP is provided several times, the last set value is used. Examples: .nf curl --referer "https://fake.example" https://example.com curl --referer "https://fake.example;auto" -L https://example.com curl --referer ";auto" -L https://example.com .fi See also \fI\-\-user\-agent\fP and \fI\-\-header\fP. .IP "\-J, \-\-remote\-header\-name" (HTTP) Tell the \fI\-\-remote\-name\fP option to use the server\-specified Content\-Disposition filename instead of extracting a filename from the URL. If the server\-provided filename contains a path, that is stripped off before the filename is used. The file is saved in the current directory, or in the directory specified with \fI\-\-output\-dir\fP. If the server specifies a filename and a file with that name already exists in the destination directory, it is not overwritten and an error occurs \- unless you allow it by using the \fI\-\-clobber\fP option. If the server does not specify a filename then this option has no effect. There is no attempt to decode %\-sequences (yet) in the provided filename, so this option may provide you with rather unexpected filenames. This feature uses the name from the "filename" field, it does not yet support the "filename*" field (filenames with explicit character sets). Starting in 8.19.0, curl falls back and uses the filename extracted from the last redirect header if no "Content\-Disposition:" header provides a filename. \fBWARNING\fP: Exercise judicious use of this option, especially on Windows. A rogue server could send you the name of a DLL or other file that could be loaded automatically by Windows or some third party software. Providing \fI\-\-remote\-header\-name\fP multiple times has no extra effect. Disable it again with \-\-no-remote-header-name. Example: .nf curl -OJ https://example.com/file .fi See also \fI\-\-remote\-name\fP. .IP "\-O, \-\-remote\-name" Write output to a local file named like the remote file we get. (Only the file part of the remote file is used, the path is cut off.) The file is saved in the current working directory. If you want the file saved in a different directory, make sure you change the current working directory before invoking curl with this option or use \fI\-\-output\-dir\fP. The remote filename to use for saving is extracted from the given URL, nothing else, and if it already exists it is overwritten. If you want the server to be able to choose the filename refer to \fI\-\-remote\-header\-name\fP which can be used in addition to this option. If the server chooses a filename and that name already exists it is not overwritten. There is no URL decoding done on the filename. If it has %20 or other URL encoded parts of the name, they end up as\-is as filename. You may use this option as many times as the number of URLs you have. Before curl 8.10.0, curl returned an error if the URL ended with a slash, which means that there is no filename part in the URL. Starting in 8.10.0, curl sets the filename to the last directory part of the URL or if that also is missing to "curl_response" (without extension) for this situation. \fI\-\-remote\-name\fP is associated with a single URL. Use it once per URL when you use several URLs in a command line. Examples: .nf curl -O https://example.com/filename curl -O https://example.com/filename -O https://example.com/file2 .fi See also \fI\-\-remote\-name\-all\fP, \fI\-\-output\-dir\fP and \fI\-\-remote\-header\-name\fP. .IP "\-\-remote\-name\-all" Change the default action for all given URLs to be dealt with as if \fI\-\-remote\-name\fP were used for each one. If you want to disable that for a specific URL after \fI\-\-remote\-name\-all\fP has been used, you must use "\-o \-" or \fI\-\-no\-remote\-name\fP. Providing \fI\-\-remote\-name\-all\fP multiple times has no extra effect. Disable it again with \-\-no-remote-name-all. Example: .nf curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2 .fi See also \fI\-\-remote\-name\fP. .IP "\-R, \-\-remote\-time" Make curl attempt to figure out the timestamp of the remote file that is getting downloaded, and if that is available make the local file get that same timestamp. Providing \fI\-\-remote\-time\fP multiple times has no extra effect. Disable it again with \-\-no-remote-time. Example: .nf curl --remote-time -o foo https://example.com .fi See also \fI\-\-remote\-name\fP and \fI\-\-time\-cond\fP. .IP "\-\-remove\-on\-error" Remove the output file if an error occurs. If curl returns an error when told to save output in a local file. This prevents curl from leaving a partial file in the case of an error during transfer. If the output is not a regular file, this option has no effect. The \fI\-\-continue\-at\fP option cannot be used together with \fI\-\-remove\-on\-error\fP. Providing \fI\-\-remove\-on\-error\fP multiple times has no extra effect. Disable it again with \-\-no-remove-on-error. Example: .nf curl --remove-on-error -o output https://example.com .fi Added in 7.83.0. See also \fI\-\-fail\fP. .IP "\-X, \-\-request <method>" Change the method to use when starting the transfer. curl passes on the verbatim string you give it in the request without any filter or other safe guards. That includes white space and control characters. .RS .IP HTTP Specifies a custom request method to use when communicating with the HTTP server. The specified request method is used instead of the method otherwise used (which defaults to \fIGET\fP). Read the HTTP 1.1 specification for details and explanations. Common additional HTTP requests include \fIPUT\fP and \fIDELETE\fP, while related technologies like WebDAV offers \fIPROPFIND\fP, \fICOPY\fP, \fIMOVE\fP and more. Normally you do not need this option. All sorts of \fIGET\fP, \fIHEAD\fP, \fIPOST\fP and \fIPUT\fP requests are rather invoked by using dedicated command line options. This option only changes the actual word used in the HTTP request, it does not alter the way curl behaves. For example if you want to make a proper HEAD request, using \-X HEAD does not suffice. You need to use the \fI\-\-head\fP option. If \fI\-\-location\fP is used, the method string you set with \fI\-\-request\fP is used for all requests, which may cause unintended side\-effects when curl does not change request method according to the HTTP 30x response codes \- and similar. Consider using \fI\-\-follow\fP instead in combination with \fI\-\-request\fP. .IP FTP Specifies a custom FTP command to use instead of \fILIST\fP when doing file lists with FTP. .IP POP3 Specifies a custom POP3 command to use instead of \fILIST\fP or \fIRETR\fP. .IP IMAP Specifies a custom IMAP command to use instead of \fILIST\fP. .IP SMTP Specifies a custom SMTP command to use instead of \fIHELP\fP or \fBVRFY\fP. .RE .IP If \fI\-\-request\fP is provided several times, the last set value is used. Examples: .nf curl --request "DELETE" https://example.com curl -X NLST ftp://example.com/ .fi See also \fI\-\-request\-target\fP and \fI\-\-follow\fP. .IP "\-\-request\-target <path>" (HTTP) Use an alternative target (path) instead of using the path as provided in the URL. Particularly useful when wanting to issue HTTP requests without leading slash or other data that does not follow the regular URL pattern, like \&"OPTIONS *". curl passes on the verbatim string you give it in the request without any filter or other safe guards. That includes white space and control characters. If \fI\-\-request\-target\fP is provided several times, the last set value is used. Example: .nf curl --request-target "*" -X OPTIONS https://example.com .fi See also \fI\-\-request\fP. .IP "\-\-resolve <[+]host:port:addr[,addr]...>" Provide a custom address for a specific host and port pair. Using this, you can make the curl requests(s) use a specified address and prevent the otherwise normally resolved address to be used. Consider it a sort of /etc/hosts alternative provided on the command line. The port number should be the number used for the specific protocol the host is used for. It means you need several entries if you want to provide addresses for the same host but different ports. By specifying "*" as host you can tell curl to resolve any host and specific port pair to the specified address. Wildcard is resolved last so any \fI\-\-resolve\fP with a specific host and port is used first. The provided address set by this option is used even if \fI\-\-ipv4\fP or \fI\-\-ipv6\fP is set to make curl use another IP version. By prefixing the host with a \(aq+\(aq you can make the entry time out after curl\(aqs default timeout (1 minute). Note that this only makes sense for long running parallel transfers with a lot of files. In such cases, if this option is used curl tries to resolve the host as it normally would once the timeout has expired. Provide IPv6 addresses within [brackets]. To redirect connects from a specific hostname or any hostname, independently of port number, consider the \fI\-\-connect\-to\fP option. Support for resolving with wildcard was added in 7.64.0. Support for the \(aq+\(aq prefix was added in 7.75.0. Support for specifying the host component as an IPv6 address was added in 8.13.0. \fI\-\-resolve\fP can be used several times in a command line Examples: .nf curl --resolve example.com:443:127.0.0.1 https://example.com curl --resolve example.com:443:[2001:db8::252f:efd6] https://example.com .fi See also \fI\-\-connect\-to\fP and \fI\-\-alt\-svc\fP. .IP "\-\-retry <num>" If a transient error is returned when curl tries to perform a transfer, it retries this number of times before giving up. Setting the number to 0 makes curl do no retries (which is the default). Transient error means either: a timeout, an FTP 4xx response code or an HTTP 408, 429, 500, 502, 503, 504, 522 or 524 response code. When curl is about to retry a transfer, it first waits one second and then for all forthcoming retries it doubles the waiting time until it reaches 10 minutes, which then remains the set fixed delay time between the rest of the retries. By using \fI\-\-retry\-delay\fP you disable this exponential backoff algorithm. See also \fI\-\-retry\-max\-time\fP to limit the total time allowed for retries. curl complies with the Retry\-After: response header if one was present to know when to issue the next retry (added in 7.66.0). If \fI\-\-retry\fP is provided several times, the last set value is used. Example: .nf curl --retry 7 https://example.com .fi See also \fI\-\-retry\-max\-time\fP, \fI\-\-retry\-connrefused\fP and \fI\-\-retry\-delay\fP. .IP "\-\-retry\-all\-errors" Retry on any error. This option is used together with \fI\-\-retry\fP. This option is the "sledgehammer" of retrying. Do not use this option by default (for example in your \fBcurlrc\fP), there may be unintended consequences such as sending or receiving duplicate data. Do not use with redirected input or output. You might be better off handling your unique problems in a shell script. Please read the example below. \fBWARNING\fP: For server compatibility curl attempts to retry failed flaky transfers as close as possible to how they were started, but this is not possible with redirected input or output. For example, before retrying it removes output data from a failed partial transfer that was written to an output file. However this is not true of data redirected to a | pipe or > file, which are not reset. We strongly suggest you do not parse or record output via redirect in combination with this option, since you may receive duplicate data. By default curl does not return an error for transfers with an HTTP response code that indicates an HTTP error, if the transfer was successful. For example, if a server replies 404 Not Found and the reply is fully received then that is not an error. When \fI\-\-retry\fP is used then curl retries on some HTTP response codes that indicate transient HTTP errors, but that does not include most 4xx response codes such as 404. If you want to retry on all response codes that indicate HTTP errors (4xx and 5xx) then combine with \fI\-\-fail\fP. Providing \fI\-\-retry\-all\-errors\fP multiple times has no extra effect. Disable it again with \-\-no-retry-all-errors. Example: .nf curl --retry 5 --retry-all-errors https://example.com .fi Added in 7.71.0. See also \fI\-\-retry\fP. .IP "\-\-retry\-connrefused" In addition to the other conditions, also consider ECONNREFUSED as a transient error for \fI\-\-retry\fP. This option is used together with \fI\-\-retry\fP. Normally, a refused connection is not considered a transient error and therefore would not otherwise trigger a retry. Providing \fI\-\-retry\-connrefused\fP multiple times has no extra effect. Disable it again with \-\-no-retry-connrefused. Example: .nf curl --retry-connrefused --retry 7 https://example.com .fi See also \fI\-\-retry\fP and \fI\-\-retry\-all\-errors\fP. .IP "\-\-retry\-delay <seconds>" Make curl sleep this amount of time before each retry when a transfer has failed with a transient error (it changes the default backoff time algorithm between retries). This option is only interesting if \fI\-\-retry\fP is also used. Setting this delay to zero makes curl use the default backoff time. By default, curl uses an exponentially increasing timeout between retries. Starting in curl 8.16.0, this option accepts a time as decimal number for parts of seconds. The decimal value needs to be provided using a dot (.) as decimal separator \- not the local version even if it might be using another separator. If \fI\-\-retry\-delay\fP is provided several times, the last set value is used. Example: .nf curl --retry-delay 5 --retry 7 https://example.com .fi See also \fI\-\-retry\fP and \fI\-\-retry\-max\-time\fP. .IP "\-\-retry\-max\-time <seconds>" The retry timer is reset before the first transfer attempt. Retries are done as usual (see \fI\-\-retry\fP) as long as the timer has not reached this given limit. Notice that if the timer has not reached the limit, the request is made and while performing, it may take longer than this given time period. To limit a single request\(aqs maximum time, use \fI\-\-max\-time\fP. Set this option to zero to not timeout retries. The retry timer starts immediately before the first transfer attempt and includes time spent sleeping between retries (such as delays defined by \fI\-\-retry\-delay\fP). Before each new retry is started, curl checks whether the elapsed time has reached the specified limit. If it has, no further retries are performed. A transfer that has already started is allowed to run to completion even if this makes the total wall clock time exceed the limit. Use \fI\-\-max\-time\fP to also cap the duration of each individual transfer attempt. Starting in curl 8.16.0, this option accepts a time as decimal number for parts of seconds. The decimal value needs to be provided using a dot (.) as decimal separator \- not the local version even if it might be using another separator. If \fI\-\-retry\-max\-time\fP is provided several times, the last set value is used. Example: .nf curl --retry-max-time 30 --retry 10 https://example.com .fi See also \fI\-\-retry\fP and \fI\-\-retry\-delay\fP. .IP "\-\-sasl\-authzid <identity>" (LDAP IMAP POP3 SMTP) Use this authorization identity (\fBauthzid\fP), during SASL PLAIN authentication, in addition to the authentication identity (\fBauthcid\fP) as specified by \fI\-\-user\fP. If the option is not specified, the server derives the \fBauthzid\fP from the \fBauthcid\fP, but if specified, and depending on the server implementation, it may be used to access another user\(aqs inbox, that the user has been granted access to, or a shared mailbox for example. If \fI\-\-sasl\-authzid\fP is provided several times, the last set value is used. Example: .nf curl --sasl-authzid zid imap://example.com/ .fi Added in 7.66.0. See also \fI\-\-login\-options\fP. .IP "\-\-sasl\-ir" (LDAP IMAP POP3 SMTP) Enable initial response in SASL authentication. Such an "initial response" is a message sent by the client to the server after the client selects an authentication mechanism. Providing \fI\-\-sasl\-ir\fP multiple times has no extra effect. Disable it again with \-\-no-sasl-ir. Example: .nf curl --sasl-ir imap://example.com/ .fi See also \fI\-\-sasl\-authzid\fP. .IP "\-\-service\-name <name>" Set the service name for SPNEGO. If \fI\-\-service\-name\fP is provided several times, the last set value is used. Example: .nf curl --service-name sockd/server https://example.com .fi See also \fI\-\-negotiate\fP and \fI\-\-proxy\-service\-name\fP. .IP "\-S, \-\-show\-error" When used with \fI\-\-silent\fP, it makes curl show an error message if it fails. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-show\-error\fP multiple times has no extra effect. Disable it again with \-\-no-show-error. Example: .nf curl --show-error --silent https://example.com .fi See also \fI\-\-no\-progress\-meter\fP. .IP "\-i, \-\-show\-headers" (HTTP FTP) Show response headers in the output. HTTP response headers can include things like server name, cookies, date of the document, HTTP version and more. With non\-HTTP protocols, the "headers" are other server communication. This option makes the response headers get saved in the same stream/output as the data. \fI\-\-dump\-header\fP exists to save headers in a separate stream. To view the request headers, consider the \fI\-\-verbose\fP option. Prior to 7.75.0 curl did not print the headers if \fI\-\-fail\fP was used in combination with this option and there was an error reported by the server. This option was called \fI\-\-include\fP before 8.10.0. The previous name remains functional. Providing \fI\-\-show\-headers\fP multiple times has no extra effect. Disable it again with \-\-no-show-headers. Example: .nf curl -i https://example.com .fi See also \fI\-\-verbose\fP and \fI\-\-dump\-header\fP. .IP "\-\-sigalgs <list>" (TLS) Set specific signature algorithms to use during SSL session establishment according to RFC 5246, 7.4.1.4.1. An algorithm can use either a signature algorithm and a hash algorithm pair separated by a \&"+" (e.g. "ECDSA+SHA224"), or its TLS 1.3 signature scheme name (e.g. "ed25519"). Multiple algorithms can be provided by separating them with ":" (e.g. "DSA+SHA256:rsa_pss_pss_sha256"). The parameter is available as "\-sigalgs" in the OpenSSL "s_client" and "s_server" utilities. \&"\fI\-\-sigalgs\fP" allows a OpenSSL powered curl to make SSL\-connections with exactly the signature algorithms requested by the client, avoiding nontransparent client/server negotiations. If this option is set, the default signature algorithm list built into OpenSSL are ignored. If \fI\-\-sigalgs\fP is provided several times, the last set value is used. Example: .nf curl --sigalgs ecdsa_secp256r1_sha256 https://example.com .fi Added in 8.14.0. See also \fI\-\-ciphers\fP. .IP "\-s, \-\-silent" Silent or quiet mode. Do not show progress meter, warning messages or error messages. Makes curl mute. It still outputs the data you ask for, potentially even to the terminal/stdout unless you redirect it. Use \fI\-\-show\-error\fP in addition to this option to disable progress meter but still show error messages. Providing \fI\-\-silent\fP multiple times has no extra effect. Disable it again with \-\-no-silent. Example: .nf curl -s https://example.com .fi See also \fI\-\-verbose\fP, \fI\-\-stderr\fP and \fI\-\-no\-progress\-meter\fP. .IP "\-\-skip\-existing" If there is a local file present when a download is requested, the operation is skipped. Note that curl cannot know if the local file was previously downloaded fine, or if it is incomplete etc, it knows if there is a filename present in the file system or not and it skips the transfer if it is. Providing \fI\-\-skip\-existing\fP multiple times has no extra effect. Disable it again with \-\-no-skip-existing. Example: .nf curl --skip-existing --output local/dir/file https://example.com .fi Added in 8.10.0. See also \fI\-\-output\fP, \fI\-\-remote\-name\fP and \fI\-\-no\-clobber\fP. .IP "\-\-socks4 <host[:port]>" Use the specified SOCKS4 proxy. If the port number is not specified, it is assumed at port 1080. Using this socket type makes curl resolve the hostname and pass the address on to the proxy. To specify the proxy on a Unix domain socket, use localhost for host and append the absolute path to the domain socket. For example: \&"socks4://localhost/path/to/socket.sock" (the scheme may be omitted). This option overrides any previous use of \fI\-\-proxy\fP, as they are mutually exclusive. This option is superfluous since you can specify a socks4 proxy with \fI\-\-proxy\fP using a socks4:// protocol prefix. \fI\-\-preproxy\fP can be used to specify a SOCKS proxy at the same time proxy is used with an HTTP/HTTPS proxy. In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If \fI\-\-socks4\fP is provided several times, the last set value is used. Example: .nf curl --socks4 hostname:4096 https://example.com .fi This option is mutually exclusive with \fI\-\-proxy\fP, \fI\-\-socks4a\fP, \fI\-\-socks5\fP and \fI\-\-socks5\-hostname\fP. See also \fI\-\-socks4a\fP, \fI\-\-socks5\fP and \fI\-\-socks5\-hostname\fP. .IP "\-\-socks4a <host[:port]>" Use the specified SOCKS4a proxy. If the port number is not specified, it is assumed at port 1080. This asks the proxy to resolve the hostname. To specify the proxy on a Unix domain socket, use localhost for host and append the absolute path to the domain socket. For example: \&"socks4a://localhost/path/to/socket.sock" (the scheme may be omitted). This option overrides any previous use of \fI\-\-proxy\fP, as they are mutually exclusive. This option is superfluous since you can specify a socks4a proxy with \fI\-\-proxy\fP using a socks4a:// protocol prefix. \fI\-\-preproxy\fP can be used to specify a SOCKS proxy at the same time \fI\-\-proxy\fP is used with an HTTP/HTTPS proxy. In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If \fI\-\-socks4a\fP is provided several times, the last set value is used. Example: .nf curl --socks4a hostname:4096 https://example.com .fi This option is mutually exclusive with \fI\-\-proxy\fP, \fI\-\-socks4\fP, \fI\-\-socks5\fP and \fI\-\-socks5\-hostname\fP. See also \fI\-\-socks4\fP, \fI\-\-socks5\fP and \fI\-\-socks5\-hostname\fP. .IP "\-\-socks5 <host[:port]>" Use the specified SOCKS5 proxy \- but resolve the hostname locally. If the port number is not specified, it is assumed at port 1080. To specify the proxy on a Unix domain socket, use localhost for host and append the absolute path to the domain socket. For example: \&"socks5://localhost/path/to/socket.sock" (the scheme may be omitted). This option overrides any previous use of \fI\-\-proxy\fP, as they are mutually exclusive. This option is superfluous since you can specify a socks5 proxy with \fI\-\-proxy\fP using a socks5:// protocol prefix. \fI\-\-preproxy\fP can be used to specify a SOCKS proxy at the same time \fI\-\-proxy\fP is used with an HTTP/HTTPS proxy. In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. This option does not work with FTPS or LDAP. If \fI\-\-socks5\fP is provided several times, the last set value is used. Examples: .nf curl --socks5 proxy.example:7000 https://example.com curl --socks5 localhost/path/unix-domain https://example.com .fi This option is mutually exclusive with \fI\-\-proxy\fP, \fI\-\-socks4\fP, \fI\-\-socks4a\fP and \fI\-\-socks5\-hostname\fP. See also \fI\-\-socks5\-hostname\fP and \fI\-\-socks4a\fP. .IP "\-\-socks5\-basic" Use username/password authentication when connecting to a SOCKS5 proxy. The username/password authentication is enabled by default. Use \fI\-\-socks5\-gssapi\fP to force GSS\-API authentication to SOCKS5 proxies. Providing \fI\-\-socks5\-basic\fP multiple times has no extra effect. Example: .nf curl --socks5-basic --socks5 hostname:4096 https://example.com .fi See also \fI\-\-socks5\fP. .IP "\-\-socks5\-gssapi" (GSS/kerberos) Use GSS\-API authentication when connecting to a SOCKS5 proxy. The GSS\-API authentication is enabled by default (if curl is compiled with GSS\-API support). Use \fI\-\-socks5\-basic\fP to force username/password authentication to SOCKS5 proxies. Providing \fI\-\-socks5\-gssapi\fP multiple times has no extra effect. Disable it again with \-\-no-socks5-gssapi. Example: .nf curl --socks5-gssapi --socks5 hostname:4096 https://example.com .fi See also \fI\-\-socks5\fP. .IP "\-\-socks5\-gssapi\-nec" (GSS/kerberos) As part of the GSS\-API negotiation a protection mode is negotiated. RFC 1961 says in section 4.3/4.4 it should be protected, but the NEC reference implementation does not. The option \fI\-\-socks5\-gssapi\-nec\fP allows the unprotected exchange of the protection mode negotiation. Providing \fI\-\-socks5\-gssapi\-nec\fP multiple times has no extra effect. Disable it again with \-\-no-socks5-gssapi-nec. Example: .nf curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com .fi See also \fI\-\-socks5\fP. .IP "\-\-socks5\-gssapi\-service <name>" Set the service name for a socks server. Default is \fBrcmd/server\-fqdn\fP. If \fI\-\-socks5\-gssapi\-service\fP is provided several times, the last set value is used. Example: .nf curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com .fi See also \fI\-\-socks5\fP. .IP "\-\-socks5\-hostname <host[:port]>" Use the specified SOCKS5 proxy (and let the proxy resolve the hostname). If the port number is not specified, it is assumed at port 1080. To specify the proxy on a Unix domain socket, use localhost for host and append the absolute path to the domain socket. For example: \&"socks5h://localhost/path/to/socket.sock" (the scheme may be omitted). This option overrides any previous use of \fI\-\-proxy\fP, as they are mutually exclusive. This option is superfluous since you can specify a socks5 hostname proxy with \fI\-\-proxy\fP using a socks5h:// protocol prefix. \fI\-\-preproxy\fP can be used to specify a SOCKS proxy at the same time \fI\-\-proxy\fP is used with an HTTP/HTTPS proxy. In such a case, curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. If \fI\-\-socks5\-hostname\fP is provided several times, the last set value is used. Example: .nf curl --socks5-hostname proxy.example:7000 https://example.com .fi This option is mutually exclusive with \fI\-\-proxy\fP, \fI\-\-socks4\fP, \fI\-\-socks4a\fP and \fI\-\-socks5\fP. See also \fI\-\-socks5\fP and \fI\-\-socks4a\fP. .IP "\-Y, \-\-speed\-limit <speed>" If a transfer is slower than this set speed (in bytes per second) for a given number of seconds, it gets aborted. The time period is set with \fI\-\-speed\-time\fP and is 30 seconds by default. If \fI\-\-speed\-limit\fP is provided several times, the last set value is used. Example: .nf curl --speed-limit 300 --speed-time 10 https://example.com .fi See also \fI\-\-speed\-time\fP, \fI\-\-limit\-rate\fP and \fI\-\-max\-time\fP. .IP "\-y, \-\-speed\-time <seconds>" If a transfer runs slower than speed\-limit bytes per second during a speed\-time period, the transfer is aborted. If speed\-time is used, the default speed\-limit is 1 unless set with \fI\-\-speed\-limit\fP. This option controls transfers (in both directions) but does not affect slow connects etc. If this is a concern for you, try the \fI\-\-connect\-timeout\fP option. If \fI\-\-speed\-time\fP is provided several times, the last set value is used. Example: .nf curl --speed-limit 300 --speed-time 10 https://example.com .fi See also \fI\-\-speed\-limit\fP and \fI\-\-limit\-rate\fP. .IP "\-\-ssl" (FTP IMAP POP3 SMTP LDAP) Warning: this is considered an insecure option. Consider using \fI\-\-ssl\-reqd\fP instead to be sure curl upgrades to a secure connection. Try to use SSL/TLS for the connection \- often referred to as STARTTLS or STLS because of the involved commands. Reverts to a non\-secure connection if the server does not support SSL/TLS. See also \fI\-\-ftp\-ssl\-control\fP and \fI\-\-ssl\-reqd\fP for different levels of encryption required. This option is handled in LDAP (added in 7.81.0). It is fully supported by the OpenLDAP backend and ignored by the generic ldap backend. Please note that a server may close the connection if the negotiation fails. This option was formerly known as \fI\-\-ftp\-ssl\fP. That option name can still be used but might be removed in a future version. Providing \fI\-\-ssl\fP multiple times has no extra effect. Disable it again with \-\-no-ssl. Example: .nf curl --ssl pop3://example.com/ .fi See also \fI\-\-ssl\-reqd\fP, \fI\-\-insecure\fP and \fI\-\-ciphers\fP. .IP "\-\-ssl\-allow\-beast" (TLS) Do not work around a security flaw in the TLS1.0 protocol known as BEAST. If this option is not used, the TLS layer may use workarounds known to cause interoperability problems with some older server implementations. This option only changes how curl does TLS 1.0 and has no effect on later TLS versions. \fBWARNING\fP: this option loosens the TLS security, and by using this flag you ask for exactly that. Providing \fI\-\-ssl\-allow\-beast\fP multiple times has no extra effect. Disable it again with \-\-no-ssl-allow-beast. Example: .nf curl --ssl-allow-beast https://example.com .fi See also \fI\-\-proxy\-ssl\-allow\-beast\fP and \fI\-\-insecure\fP. .IP "\-\-ssl\-auto\-client\-cert" (TLS) (Schannel) Automatically locate and use a client certificate for authentication, when requested by the server. Since the server can request any certificate that supports client authentication in the OS certificate store it could be a privacy violation and unexpected. Providing \fI\-\-ssl\-auto\-client\-cert\fP multiple times has no extra effect. Disable it again with \-\-no-ssl-auto-client-cert. Example: .nf curl --ssl-auto-client-cert https://example.com .fi Added in 7.77.0. See also \fI\-\-proxy\-ssl\-auto\-client\-cert\fP. .IP "\-\-ssl\-no\-revoke" (TLS) (Schannel) Disable certificate revocation checks. WARNING: this option loosens the SSL security, and by using this flag you ask for exactly that. Providing \fI\-\-ssl\-no\-revoke\fP multiple times has no extra effect. Disable it again with \-\-no-ssl-no-revoke. Example: .nf curl --ssl-no-revoke https://example.com .fi See also \fI\-\-crlfile\fP. .IP "\-\-ssl\-reqd" (FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection \- often referred to as STARTTLS or STLS because of the involved commands. Terminates the connection if the transfer cannot be upgraded to use SSL/TLS. This option is handled in LDAP (added in 7.81.0). It is fully supported by the OpenLDAP backend and rejected by the generic ldap backend if explicit TLS is required. This option is unnecessary if you use a URL scheme that in itself implies immediate and implicit use of TLS, like for FTPS, IMAPS, POP3S, SMTPS and LDAPS. Such a transfer always fails if the TLS handshake does not work. This option was formerly known as \fI\-\-ftp\-ssl\-reqd\fP. Providing \fI\-\-ssl\-reqd\fP multiple times has no extra effect. Disable it again with \-\-no-ssl-reqd. Example: .nf curl --ssl-reqd ftp://example.com .fi See also \fI\-\-ssl\fP and \fI\-\-insecure\fP. .IP "\-\-ssl\-revoke\-best\-effort" (TLS) (Schannel) Ignore certificate revocation checks when they failed due to missing/offline distribution points for the revocation check lists. Providing \fI\-\-ssl\-revoke\-best\-effort\fP multiple times has no extra effect. Disable it again with \-\-no-ssl-revoke-best-effort. Example: .nf curl --ssl-revoke-best-effort https://example.com .fi Added in 7.70.0. See also \fI\-\-crlfile\fP and \fI\-\-insecure\fP. .IP "\-\-ssl\-sessions <filename>" (TLS) **WARNING**: this option is experimental. Do not use in production. Use the given file to load SSL session tickets into curl\(aqs cache before starting any transfers. At the end of a successful curl run, the cached SSL sessions tickets are saved to the file, replacing any previous content. The file does not have to exist, but curl reports an error if it is unable to create it. Unused loaded tickets are saved again, unless they get replaced or purged from the cache for space reasons. Using a session file allows "\fI\-\-tls\-earlydata\fP" to send the first request in "0\-RTT" mode, should an SSL session with the feature be found. Note that a server may not support early data. Also note that early data does not provide forward secrecy, e.g. is not as secure. The SSL session tickets are stored as base64 encoded text, each ticket on its own line. The hostnames are cryptographically salted and hashed. While this prevents someone from easily seeing the hosts you contacted, they could still check if a specific hostname matches one of the values. This feature requires that the underlying libcurl was built with the experimental SSL session import/export feature (SSLS\-EXPORT) enabled. If \fI\-\-ssl\-sessions\fP is provided several times, the last set value is used. Example: .nf curl --ssl-sessions sessions.txt https://example.com .fi Added in 8.12.0. See also \fI\-\-tls\-earlydata\fP. .IP "\-2, \-\-sslv2" (SSL) This option previously asked curl to use SSLv2, but is now ignored (added in 7.77.0). SSLv2 is widely considered insecure (see RFC 6176). Providing \fI\-\-sslv2\fP multiple times has no extra effect. Example: .nf curl --sslv2 https://example.com .fi For \fI\-\-sslv2\fP to work, it requires that the underlying libcurl is built to support TLS. This option is mutually exclusive with \fI\-\-sslv3\fP, \fI\-\-tlsv1\fP, \fI\-\-tlsv1.1\fP and \fI\-\-tlsv1.2\fP. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-3, \-\-sslv3" (SSL) This option previously asked curl to use SSLv3, but is now ignored (added in 7.77.0). SSLv3 is widely considered insecure (see RFC 7568). Providing \fI\-\-sslv3\fP multiple times has no extra effect. Example: .nf curl --sslv3 https://example.com .fi For \fI\-\-sslv3\fP to work, it requires that the underlying libcurl is built to support TLS. This option is mutually exclusive with \fI\-\-sslv2\fP, \fI\-\-tlsv1\fP, \fI\-\-tlsv1.1\fP and \fI\-\-tlsv1.2\fP. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-\-stderr <file>" Redirect all writes to stderr to the specified file instead. If the filename is a plain \(aq\-\(aq, it is instead written to stdout. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-stderr\fP is provided several times, the last set value is used. Example: .nf curl --stderr output.txt https://example.com .fi See also \fI\-\-verbose\fP and \fI\-\-silent\fP. .IP "\-\-styled\-output" Enable automatic use of bold font styles when writing HTTP headers to the terminal. Use \fI\-\-no\-styled\-output\fP to switch them off. Styled output requires a terminal that supports bold fonts. This feature is not present on curl for Windows due to lack of this capability. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-styled\-output\fP multiple times has no extra effect. Disable it again with \-\-no-styled-output. Example: .nf curl --styled-output -I https://example.com .fi See also \fI\-\-head\fP and \fI\-\-verbose\fP. .IP "\-\-suppress\-connect\-headers" When \fI\-\-proxytunnel\fP is used and a CONNECT request is made, do not output proxy CONNECT response headers. This option is meant to be used with \fI\-\-dump\-header\fP or \fI\-\-show\-headers\fP which are used to show protocol headers in the output. It has no effect on debug options such as \fI\-\-verbose\fP or \fI\-\-trace\fP, or any statistics. Providing \fI\-\-suppress\-connect\-headers\fP multiple times has no extra effect. Disable it again with \-\-no-suppress-connect-headers. Example: .nf curl --suppress-connect-headers --show-headers -x proxy https://example.com .fi See also \fI\-\-dump\-header\fP, \fI\-\-show\-headers\fP and \fI\-\-proxytunnel\fP. .IP "\-\-tcp\-fastopen" Enable use of TCP Fast Open (RFC 7413). TCP Fast Open is a TCP extension that allows data to be sent earlier over the connection (before the final handshake ACK) if the client and server have been connected previously. Providing \fI\-\-tcp\-fastopen\fP multiple times has no extra effect. Disable it again with \-\-no-tcp-fastopen. Example: .nf curl --tcp-fastopen https://example.com .fi See also \fI\-\-false\-start\fP. .IP "\-\-tcp\-nodelay" Turn on the TCP_NODELAY option. This option disables the Nagle algorithm on TCP connections. The purpose of this algorithm is to minimize the number of small packets on the network (where "small packets" means TCP segments less than the Maximum Segment Size for the network). Maximizing the amount of data sent per TCP segment is good because it amortizes the overhead of the send. In some cases small segments may need to be sent without delay. This is less efficient than sending larger amounts of data at a time, and can contribute to congestion on the network if overdone. curl sets this option by default and you need to explicitly switch it off if you do not want it on. Providing \fI\-\-tcp\-nodelay\fP multiple times has no extra effect. Disable it again with \-\-no-tcp-nodelay. Example: .nf curl --tcp-nodelay https://example.com .fi See also \fI\-\-no\-buffer\fP. .IP "\-t, \-\-telnet\-option <opt=val>" (TELNET) Pass options to the telnet protocol. Supported options are: .RS .IP TTYPE=<term> Sets the terminal type. .IP "XDISPLOC=<X display>" Sets the X display location. .IP NEW_ENV=<var,val> Sets an environment variable. .RE .IP \fI\-\-telnet\-option\fP can be used several times in a command line Example: .nf curl -t TTYPE=vt100 telnet://example.com/ .fi See also \fI\-\-config\fP. .IP "\-\-tftp\-blksize <value>" (TFTP) Set the TFTP \fBBLKSIZE\fP option (must be 512 or larger). This is the block size that curl tries to use when transferring data to or from a TFTP server. By default 512 bytes are used. If \fI\-\-tftp\-blksize\fP is provided several times, the last set value is used. Example: .nf curl --tftp-blksize 1024 tftp://example.com/file .fi See also \fI\-\-tftp\-no\-options\fP. .IP "\-\-tftp\-no\-options" (TFTP) Do not send TFTP options requests. This improves interop with some legacy servers that do not acknowledge or properly implement TFTP options. When this option is used \fI\-\-tftp\-blksize\fP is ignored. Providing \fI\-\-tftp\-no\-options\fP multiple times has no extra effect. Disable it again with \-\-no-tftp-no-options. Example: .nf curl --tftp-no-options tftp://192.168.0.1/ .fi See also \fI\-\-tftp\-blksize\fP. .IP "\-z, \-\-time\-cond <time>" (HTTP FTP) Request a file that has been modified later than the given time and date, or one that has been modified before that time. The date expression can be all sorts of date strings or if it does not match any internal ones, it is treated as a filename and curl tries to get the modification date (mtime) from that file instead. See the \fIcurl_getdate(3)\fP man page for date expression details. Start the date expression with a dash (\-) to make it request for a document that is older than the given date/time, default is a document that is newer than the specified date/time. If provided a non\-existing file, curl outputs a warning about that fact and proceeds to do the transfer without a time condition. If \fI\-\-time\-cond\fP is provided several times, the last set value is used. Examples: .nf curl -z "Wed 01 Sep 2021 12:18:00" https://example.com curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com curl -z file https://example.com .fi See also \fI\-\-etag\-compare\fP and \fI\-\-remote\-time\fP. .IP "\-\-tls\-earlydata" (TLS) Enable the use of TLSv1.3 early data, also known as \(aq0RTT\(aq where possible. This has security implications for the requests sent that way. This option can be used when curl is built to use GnuTLS, wolfSSL, quictls and OpenSSL as a TLS provider (but not BoringSSL, AWS\-LC, or Rustls). If a server supports this TLSv1.3 feature, and to what extent, is announced as part of the TLS "session" sent back to curl. Until curl has seen such a session in a previous request, early data cannot be used. When a new connection is initiated with a known TLSv1.3 session, and that session announced early data support, the first request on this connection is sent \fIbefore\fP the TLS handshake is complete. While the early data is also encrypted, it is not protected against replays. An attacker can send your early data to the server again and the server would accept it. If your request contacts a public server and only retrieves a file, there may be no harm in that. If the first request orders a refrigerator for you, it is probably not a good idea to use early data for it. curl cannot deduce what the security implications of your requests actually are and make this decision for you. The amount of early data sent can be inspected by using the "\fI\-\-write\-out\fP" variable "tls_earlydata". \fBWARNING\fP: this option has security implications. See above for more details. Providing \fI\-\-tls\-earlydata\fP multiple times has no extra effect. Disable it again with \-\-no-tls-earlydata. Example: .nf curl --tls-earlydata https://example.com .fi Added in 8.11.0. See also \fI\-\-tlsv1.3\fP, \fI\-\-tls\-max\fP and \fI\-\-ssl\-sessions\fP. .IP "\-\-tls\-max <VERSION>" (TLS) Set the maximum allowed TLS version. The minimum acceptable version is set by tlsv1.0, tlsv1.1, tlsv1.2 or tlsv1.3. If the connection is done without TLS, this option has no effect. This includes QUIC\-using (HTTP/3) transfers. .RS .IP default Use up to the recommended TLS version. .IP 1.0 Use up to TLSv1.0. .IP 1.1 Use up to TLSv1.1. .IP 1.2 Use up to TLSv1.2. .IP 1.3 Use up to TLSv1.3. .RE .IP If \fI\-\-tls\-max\fP is provided several times, the last set value is used. Examples: .nf curl --tls-max 1.2 https://example.com curl --tls-max 1.3 --tlsv1.2 https://example.com .fi For \fI\-\-tls\-max\fP to work, it requires that the underlying libcurl is built to support TLS. See also \fI\-\-tlsv1.0\fP, \fI\-\-tlsv1.1\fP, \fI\-\-tlsv1.2\fP and \fI\-\-tlsv1.3\fP. .IP "\-\-tls13\-ciphers <list>" (TLS) Set which cipher suites to use in the connection if it negotiates TLS 1.3. The list of ciphers suites must specify valid ciphers. Read up on TLS 1.3 cipher suite details on this URL: https://curl.se/docs/ssl\-ciphers.html This option is used when curl is built to use OpenSSL 1.1.1 or later, wolfSSL, or mbedTLS 3.6.0 or later. Before curl 8.10.0 with mbedTLS or wolfSSL, TLS 1.3 cipher suites were set by using the \fI\-\-ciphers\fP option. If \fI\-\-tls13\-ciphers\fP is provided several times, the last set value is used. Example: .nf curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com .fi See also \fI\-\-ciphers\fP, \fI\-\-proxy\-tls13\-ciphers\fP and \fI\-\-curves\fP. .IP "\-\-tlsauthtype <type>" (TLS) Set TLS authentication type. Currently, the only supported option is "SRP", for TLS\-SRP (RFC 5054). If \fI\-\-tlsuser\fP and \fI\-\-tlspassword\fP are specified but \fI\-\-tlsauthtype\fP is not, then this option defaults to "SRP". This option works only if the underlying libcurl is built with TLS\-SRP support, which requires OpenSSL or GnuTLS with TLS\-SRP support. If \fI\-\-tlsauthtype\fP is provided several times, the last set value is used. Example: .nf curl --tlsauthtype SRP https://example.com .fi See also \fI\-\-tlsuser\fP. .IP "\-\-tlspassword <string>" (TLS) Set password to use with the TLS authentication method specified with \fI\-\-tlsauthtype\fP. Requires that \fI\-\-tlsuser\fP is set. This option does not work with TLS 1.3. If \fI\-\-tlspassword\fP is provided several times, the last set value is used. Example: .nf curl --tlspassword pwd --tlsuser user https://example.com .fi See also \fI\-\-tlsuser\fP. .IP "\-\-tlsuser <name>" (TLS) Set username for use with the TLS authentication method specified with \fI\-\-tlsauthtype\fP. Requires that \fI\-\-tlspassword\fP also is set. This option does not work with TLS 1.3. If \fI\-\-tlsuser\fP is provided several times, the last set value is used. Example: .nf curl --tlspassword pwd --tlsuser user https://example.com .fi See also \fI\-\-tlspassword\fP. .IP "\-1, \-\-tlsv1" (TLS) Use at least TLS version 1.x when negotiating with a remote TLS server. That means TLS version 1.0 or higher Providing \fI\-\-tlsv1\fP multiple times has no extra effect. Example: .nf curl --tlsv1 https://example.com .fi For \fI\-\-tlsv1\fP to work, it requires that the underlying libcurl is built to support TLS. This option is mutually exclusive with \fI\-\-tlsv1.1\fP, \fI\-\-tlsv1.2\fP and \fI\-\-tlsv1.3\fP. See also \fI\-\-http1.1\fP and \fI\-\-http2\fP. .IP "\-\-tlsv1.0" (TLS) Force curl to use TLS version 1.0 or later when connecting to a remote TLS server. In old versions of curl this option was documented to allow _only_ TLS 1.0. That behavior was inconsistent depending on the TLS library. Use \fI\-\-tls\-max\fP if you want to set a maximum TLS version. Providing \fI\-\-tlsv1.0\fP multiple times has no extra effect. Example: .nf curl --tlsv1.0 https://example.com .fi See also \fI\-\-tlsv1.3\fP. .IP "\-\-tlsv1.1" (TLS) Force curl to use TLS version 1.1 or later when connecting to a remote TLS server. In old versions of curl this option was documented to allow _only_ TLS 1.1. That behavior was inconsistent depending on the TLS library. Use \fI\-\-tls\-max\fP if you want to set a maximum TLS version. Providing \fI\-\-tlsv1.1\fP multiple times has no extra effect. Example: .nf curl --tlsv1.1 https://example.com .fi See also \fI\-\-tlsv1.3\fP and \fI\-\-tls\-max\fP. .IP "\-\-tlsv1.2" (TLS) Force curl to use TLS version 1.2 or later when connecting to a remote TLS server. In old versions of curl this option was documented to allow _only_ TLS 1.2. That behavior was inconsistent depending on the TLS library. Use \fI\-\-tls\-max\fP if you want to set a maximum TLS version. Providing \fI\-\-tlsv1.2\fP multiple times has no extra effect. Example: .nf curl --tlsv1.2 https://example.com .fi See also \fI\-\-tlsv1.3\fP and \fI\-\-tls\-max\fP. .IP "\-\-tlsv1.3" (TLS) Force curl to use TLS version 1.3 or later when connecting to a remote TLS server. If the connection is done without TLS, this option has no effect. This includes QUIC\-using (HTTP/3) transfers. Note that TLS 1.3 is not supported by all TLS backends. Providing \fI\-\-tlsv1.3\fP multiple times has no extra effect. Example: .nf curl --tlsv1.3 https://example.com .fi See also \fI\-\-tlsv1.2\fP and \fI\-\-tls\-max\fP. .IP "\-\-tr\-encoding" (HTTP) Request a compressed Transfer\-Encoding response using one of the algorithms curl supports, and uncompress the data while receiving it. This method was once intended to be the way to do automatic data compression for HTTP but for all practical purposes using Content\-Encoding as done with \fI\-\-compressed\fP has superseded transfer encoding. The \fI\-\-tr\-encoding\fP option is therefore often not be one you want. Providing \fI\-\-tr\-encoding\fP multiple times has no extra effect. Disable it again with \-\-no-tr-encoding. Example: .nf curl --tr-encoding https://example.com .fi See also \fI\-\-compressed\fP. .IP "\-\-trace <file>" Save a full trace dump of all incoming and outgoing data, including descriptive information, in the given output file. Use "\-" as filename to have the output sent to stdout. Use "%" as filename to have the output sent to stderr. Note that verbose output of curl activities and network traffic might contain sensitive data, including usernames, credentials or secret data content. Be aware and be careful when sharing trace logs with others. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-trace\fP is provided several times, the last set value is used. Example: .nf curl --trace log.txt https://example.com .fi This option is mutually exclusive with \fI\-\-verbose\fP and \fI\-\-trace\-ascii\fP. See also \fI\-\-trace\-ascii\fP, \fI\-\-trace\-config\fP, \fI\-\-trace\-ids\fP and \fI\-\-trace\-time\fP. .IP "\-\-trace\-ascii <file>" Save a full trace dump of all incoming and outgoing data, including descriptive information, in the given output file. Use "\-" as filename to have the output sent to stdout. Use "%" as filename to send the output to stderr. This is similar to \fI\-\-trace\fP, but leaves out the hex part and only shows the ASCII part of the dump. It makes smaller output that might be easier to read for untrained humans. Note that verbose output of curl activities and network traffic might contain sensitive data, including usernames, credentials or secret data content. Be aware and be careful when sharing trace logs with others. This option is global and does not need to be specified for each use of \fI\-\-next\fP. If \fI\-\-trace\-ascii\fP is provided several times, the last set value is used. Example: .nf curl --trace-ascii log.txt https://example.com .fi This option is mutually exclusive with \fI\-\-trace\fP and \fI\-\-verbose\fP. See also \fI\-\-verbose\fP and \fI\-\-trace\fP. .IP "\-\-trace\-config <string>" Set configuration for trace output. A comma\-separated list of components where detailed output can be made available from. Names are case\-insensitive. Specify \(aqall\(aq to enable all trace components. In addition to trace component names, specify "ids" and "time" to avoid extra \fI\-\-trace\-ids\fP or \fI\-\-trace\-time\fP parameters. See the \fIcurl_global_trace(3)\fP man page for more details. This option is global and does not need to be specified for each use of \fI\-\-next\fP. \fI\-\-trace\-config\fP can be used several times in a command line Example: .nf curl --trace-config ids,http/2 https://example.com .fi Added in 8.3.0. See also \fI\-\-verbose\fP and \fI\-\-trace\fP. .IP "\-\-trace\-ids" Prepend the transfer and connection identifiers to each trace or verbose line that curl displays. The identifiers are unique numbers assigned to each connection and transfer to allow a user to better understand which transfer and connection each verbose output line refers to. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-trace\-ids\fP multiple times has no extra effect. Disable it again with \-\-no-trace-ids. Example: .nf curl --trace-ids --trace-ascii output https://example.com .fi Added in 8.2.0. See also \fI\-\-trace\fP and \fI\-\-verbose\fP. .IP "\-\-trace\-time" Prepend a time stamp to each trace or verbose line that curl displays. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-trace\-time\fP multiple times has no extra effect. Disable it again with \-\-no-trace-time. Example: .nf curl --trace-time --trace-ascii output https://example.com .fi See also \fI\-\-trace\fP and \fI\-\-verbose\fP. .IP "\-\-unix\-socket <path>" (HTTP) Connect to the server through this Unix domain socket, instead of using the network. To connect to a proxy over Unix domain socket, see \fI\-\-proxy\fP. If \fI\-\-unix\-socket\fP is provided several times, the last set value is used. Example: .nf curl --unix-socket socket-path https://example.com .fi See also \fI\-\-abstract\-unix\-socket\fP. .IP "\-T, \-\-upload\-file <file>" Upload the specified local file to the remote URL. If there is no file part in the specified URL, curl appends the local file name to the end of the URL before the operation starts. You must use a trailing slash (/) on the last directory to prove to curl that there is no filename or curl thinks that your last directory name is the remote filename to use. When putting the local filename at the end of the URL, curl ignores what is on the left side of any slash (/) or backslash (\\\\) used in the filename and only appends what is on the right side of the rightmost such character. Use the filename "\-" (a single dash) to use stdin instead of a given file. Alternately, the filename "." (a single period) may be specified instead of \&"\-" to use stdin in non\-blocking mode to allow reading server output while stdin is being uploaded. If this option is used with an HTTP(S) URL, the PUT method is used. You can specify one \fI\-\-upload\-file\fP for each URL on the command line. Each \fI\-\-upload\-file\fP + URL pair specifies what to upload and to where. curl also supports globbing of the \fI\-\-upload\-file\fP argument, meaning that you can upload multiple files to a single URL by using the same URL globbing style supported in the URL. When uploading to an SMTP server: the uploaded data is assumed to be RFC 5322 formatted. It has to feature the necessary set of headers and mail body formatted correctly by the user as curl does not transcode nor encode it further in any way. \fI\-\-upload\-file\fP is associated with a single URL. Use it once per URL when you use several URLs in a command line. Examples: .nf curl -T file https://example.com curl -T "img[1-1000].png" ftp://ftp.example.com/ curl --upload-file "{file1,file2}" https://example.com curl -T file -T file2 https://example.com https://example.com .fi See also \fI\-\-get\fP, \fI\-\-head\fP, \fI\-\-request\fP and \fI\-\-data\fP. .IP "\-\-upload\-flags <flags>" (IMAP) Specify additional behavior to apply to uploaded files. Flags are specified as either a single flag value or a comma\-separated list of flag values. These values are case\-sensitive and may be negated by prepending them with a \(aq\-\(aq character. Currently the following flag values are accepted: answered, deleted, draft, flagged, and seen. The currently accepted flag values are used to set flags on IMAP uploads. If \fI\-\-upload\-flags\fP is provided several times, the last set value is used. Example: .nf curl --upload-flags Flagged,!Seen --upload-file local/dir/file https://example.com .fi Added in 8.13.0. See also \fI\-\-upload\-file\fP. .IP "\-\-url <url/file>" Specify a URL to fetch or send data to. If the given URL is missing a scheme (such as "http://" or "ftp://" etc) curl guesses which scheme to use based on the hostname. If the outermost subdomain name matches DICT, FTP, IMAP, LDAP, POP3 or SMTP case insensitively, then that protocol is used, otherwise it assumes HTTP. Scheme guessing can be avoided by providing a full URL including the scheme, or disabled by setting a default protocol, see \fI\-\-proto\-default\fP for details. To control where the contents of a retrieved URL is written instead of the default stdout, use the \fI\-\-output\fP or the \fI\-\-remote\-name\fP options. When retrieving multiple URLs in a single invoke, each provided URL needs its own dedicated destination option unless \fI\-\-remote\-name\-all\fP is used. On Windows, "file://" accesses can be converted to network accesses by the operating system. Starting in curl 8.13.0, curl can be told to download URLs provided in a text file, one URL per line. It is done with "\fI\-\-url\fP @filename": so instead of a URL, you specify a filename prefixed with the "@" symbol. It can be told to load the list of URLs from stdin by providing an argument like "@\-". When downloading URLs given in a file, it implies using \fI\-\-remote\-name\fP for each provided URL. The URLs are full, there is no globbing applied or done on these. Features such as \fI\-\-skip\-existing\fP work fine in combination with this. Lines in the URL file that start with "#" are treated as comments and are skipped. \fI\-\-url\fP can be used several times in a command line Examples: .nf curl --url https://example.com curl --url @file .fi See also \fI\-\-next\fP, \fI\-\-config\fP, \fI\-\-path\-as\-is\fP and \fI\-\-disallow\-username\-in\-url\fP. .IP "\-\-url\-query <data>" Add a piece of data, usually a name + value pair, to the end of the URL query part. The syntax is identical to that used for \fI\-\-data\-urlencode\fP with one extension: If the argument starts with a \(aq+\(aq (plus), the rest of the string is provided as\-is unencoded. The query part of a URL is the one following the question mark on the right end. \fI\-\-url\-query\fP can be used several times in a command line Examples: .nf curl --url-query name=val https://example.com curl --url-query =encodethis http://example.net/foo curl --url-query name@file https://example.com curl --url-query @fileonly https://example.com curl --url-query "+name=%20foo" https://example.com .fi Added in 7.87.0. See also \fI\-\-data\-urlencode\fP and \fI\-\-get\fP. .IP "\-B, \-\-use\-ascii" (FTP LDAP TFTP) Enable ASCII transfer mode. For FTP, this can also be enforced by using a URL that ends with ";type=A". For TFTP, this can also be enforced by using a URL that ends with ";mode=netascii". This option causes data sent to stdout to be in text mode for Win32 systems. Providing \fI\-\-use\-ascii\fP multiple times has no extra effect. Disable it again with \-\-no-use-ascii. Example: .nf curl -B ftp://example.com/README .fi See also \fI\-\-crlf\fP and \fI\-\-data\-ascii\fP. .IP "\-u, \-\-user <user:password>" Specify the username and password to use for server authentication. Overrides \fI\-\-netrc\fP and \fI\-\-netrc\-optional\fP. If you specify only the username, curl prompts for a password. The username and passwords are split up on the first colon, which makes it impossible to use a colon in the username with this option. The password can, still. On systems where it works, curl hides the given option argument from process listings. This is not enough to protect credentials from possibly getting seen by other users on the same system as they still are visible for a moment before being cleared. Such sensitive data should be retrieved from a file instead or similar and never used in clear text in a command line. When using Kerberos V5 with a Windows based server you should include the Windows domain name in the username, in order for the server to successfully obtain a Kerberos Ticket. If you do not, then the initial authentication handshake may fail. When using NTLM, the username can be specified without the domain, if there is a single domain and forest in your setup for example. To specify the domain name use either Down\-Level Logon Name or UPN (User Principal Name) formats. For example, EXAMPLE\\user and user@example.com respectively. If you use a Windows SSPI\-enabled curl binary and perform Kerberos V5, Negotiate, NTLM or Digest authentication then you can tell curl to select the username and password from your environment by specifying a single colon with this option: "\-u :". If \fI\-\-user\fP is provided several times, the last set value is used. Example: .nf curl -u user:secret https://example.com .fi See also \fI\-\-netrc\fP and \fI\-\-config\fP. .IP "\-A, \-\-user\-agent <name>" (HTTP) Specify the User\-Agent string to send to the HTTP server. To encode blanks in the string, surround the string with single quote marks. This header can also be set with the \fI\-\-header\fP or the \fI\-\-proxy\-header\fP options. If you give an empty argument to \fI\-\-user\-agent\fP (""), it removes the header completely from the request. If you prefer a blank header, you can set it to a single space (" "). By default, curl uses curl/VERSION, such as User\-Agent: curl/8.20.0. If \fI\-\-user\-agent\fP is provided several times, the last set value is used. Example: .nf curl -A "Agent 007" https://example.com .fi See also \fI\-\-header\fP and \fI\-\-proxy\-header\fP. .IP "\-\-variable <[%]name=text/@file>" Set a variable with "name=content" or "name@file" (where "file" can be stdin if set to a single dash ("\-")). The name is a case sensitive identifier that must consist of no other letters than a\-z, A\-Z, 0\-9 or underscore. The specified content is then associated with this identifier. Setting the same variable name again overwrites the old contents with the new. The contents of a variable can be referenced in a later command line option when that option name is prefixed with "\fI\-\-expand\-\fP", and the name is used as \&"{{name}}". \fI\-\-variable\fP can import environment variables into the name space. Opt to either require the environment variable to be set or provide a default value for the variable in case it is not already set. \fI\-\-variable\fP %name imports the variable called "name" but exits with an error if that environment variable is not already set. To provide a default value if the environment variable is not set, use \fI\-\-variable\fP %name=content or \fI\-\-variable\fP %name@content. Note that on some systems \- but not all \- environment variables are case insensitive. Added in curl 8.12.0: you can get a byte range from the source by appending \&"[start\-end]" to the variable name, where \fIstart\fP and \fIend\fP are byte offsets to include from the contents. For example, asking for offset "2\-10" means offset two to offset ten, inclusive, resulting in 9 bytes in total. "2\-2" means a single byte at offset 2. Not providing a second number implies to the end of data. The start offset cannot be larger than the end offset. Asking for a range that is outside of the file size makes the variable contents empty. For example, getting the first one hundred bytes from a given file: .nf curl \--variable "fraction[0\-99]@filename" .fi Given a byte range that has no data results in an empty string. Asking for a range that is larger than the content makes curl use the piece of the data that exists. To assign a variable using contents from another variable, use \fI\-\-expand\-variable\fP. Like for example assigning a new variable using contents from two other: .nf curl \--expand\-variable "user={{firstname}} {{lastname}}" .fi When expanding variables, curl supports a set of functions that can make the variable contents more convenient to use. You apply a function to a variable expansion by adding a colon and then list the desired functions in a comma\-separated list that is evaluated in a left\-to\-right order. Variable content holding null bytes that are not encoded when expanded causes an error. Available functions: .RS .IP trim removes all leading and trailing white space. Example: .nf curl \--expand\-url https://example.com/{{var:trim}} .fi .IP json outputs the content using JSON string quoting rules. Example: .nf curl \--expand\-data {{data:json}} https://example.com .fi .IP url shows the content URL (percent) encoded. Example: .nf curl \--expand\-url https://example.com/{{path:url}} .fi .IP b64 expands the variable base64 encoded Example: .nf curl \--expand\-url https://example.com/{{var:b64}} .fi .IP 64dec decodes a base64 encoded character sequence. If the sequence is not possible to decode, it instead outputs "[64dec\-fail]" Example: .nf curl \--expand\-url https://example.com/{{var:64dec}} .fi (Added in 8.13.0) .RE .IP \fI\-\-variable\fP can be used several times in a command line Example: .nf curl --variable name=smith --expand-url "https://example.com/{{name}}" .fi Added in 8.3.0. See also \fI\-\-config\fP. .IP "\-v, \-\-verbose" Make curl output verbose information during the operation. Useful for debugging and seeing what\(aqs going on under the hood. Verbose output lines are prefixed with letters: .RS .IP > header sent by curl .IP < header received by curl .IP } data sent by curl .IP { data received by curl .IP * additional info provided by curl. Text that adds explanations what goes on and about choices curl does. .RE .IP If you only want HTTP headers in the output, \fI\-\-show\-headers\fP or \fI\-\-dump\-header\fP might be more suitable options. Since curl 8.10, mentioning this option several times in the same argument increases the level of the trace output. As before, a single \fI\-\-verbose\fP or \fI\-\-no\-verbose\fP reverts any additions by previous "\-vv" again. This means that \&"\-vv \-v" is equivalent to a single \-v. This avoids unwanted verbosity when the option is mentioned in the command line \fIand\fP curl config files. Using it twice, e.g. "\-vv", outputs time (\fI\-\-trace\-time\fP) and transfer ids (\fI\-\-trace\-ids\fP), as well as enabling tracing for all protocols (\fI\-\-trace\-config\fP protocol). Adding a third verbose outputs transfer content (\fI\-\-trace\-ascii\fP %) and enables tracing of more components (\fI\-\-trace\-config\fP read,write,ssl). A fourth time adds tracing of all network components. (\fI\-\-trace\-config\fP network). Any addition of the verbose option after that has no effect. If you think this option does not give you the right details, consider using \fI\-\-trace\fP or \fI\-\-trace\-ascii\fP instead. Or use it only once and use \fI\-\-trace\-config\fP to trace the specific components you wish to see. Note that verbose output of curl activities and network traffic might contain sensitive data, including usernames, credentials or secret data content. Be aware and be careful when sharing trace logs with others. When the output contains protocol headers, those lines might include carriage return (ASCII code 13) characters, even on platforms that otherwise normally only use linefeed to signify line separations \- as curl shows the exact contents arriving from the server. This option is global and does not need to be specified for each use of \fI\-\-next\fP. Providing \fI\-\-verbose\fP multiple times has no extra effect. Disable it again with \-\-no-verbose. Example: .nf curl --verbose https://example.com .fi This option is mutually exclusive with \fI\-\-trace\fP and \fI\-\-trace\-ascii\fP. See also \fI\-\-show\-headers\fP, \fI\-\-silent\fP, \fI\-\-trace\fP and \fI\-\-trace\-ascii\fP. .IP "\-V, \-\-version" Display information about curl and the libcurl version it uses. The first line includes the full version of curl, libcurl and other 3rd party libraries linked with the executable. This line may contain one or more TLS libraries. curl can be built to support more than one TLS library which then makes curl \- at start\-up \- select which particular backend to use for this invocation. If curl supports more than one TLS library like this, the ones that are \fInot\fP selected by default are listed within parentheses. Thus, if you do not specify which backend to use (with the "CURL_SSL_BACKEND" environment variable) the one listed without parentheses is used. Such builds also have "MultiSSL" set as a feature. The second line (starts with "Release\-Date:") shows the release date. The third line (starts with "Protocols:") shows all protocols that libcurl reports to support. The fourth line (starts with "Features:") shows specific features libcurl reports to offer. Available features include: .RS .IP alt-svc Support for the Alt\-Svc: header is provided. .IP AsynchDNS This curl uses asynchronous name resolves. Asynchronous name resolves can be done using either the c\-ares or the threaded resolver backends. .IP brotli Support for automatic brotli compression over HTTP(S). .IP CharConv curl was built with support for character set conversions (like EBCDIC) .IP Debug This curl uses a libcurl built with Debug. This enables more error\-tracking and memory debugging etc. For curl\-developers only. .IP ECH ECH support is present. .IP gsasl The built\-in SASL authentication includes extensions to support SCRAM because libcurl was built with libgsasl. .IP GSS-API GSS\-API is supported. .IP HSTS HSTS support is present. .IP HTTP2 HTTP/2 support has been built\-in. .IP HTTP3 HTTP/3 support has been built\-in. .IP HTTPS-proxy This curl is built to support HTTPS proxy. .IP IDN This curl supports IDN \- international domain names. .IP IPv6 You can use IPv6 with this. .IP Kerberos Kerberos V5 authentication is supported. .IP Largefile This curl supports transfers of large files, files larger than 2GB. .IP libz Automatic decompression (via gzip, deflate) of compressed files over HTTP is supported. .IP MultiSSL This curl supports multiple TLS backends. .IP NTLM NTLM authentication is supported. .IP NTLM_WB NTLM delegation to winbind helper is supported. This feature was removed from curl in 8.8.0. .IP PSL PSL is short for Public Suffix List and means that this curl has been built with knowledge about "public suffixes". .IP SPNEGO SPNEGO authentication is supported. .IP SSL SSL versions of various protocols are supported, such as HTTPS, FTPS, POP3S and so on. .IP SSLS-EXPORT This build supports TLS session export/import, like with the \fI\-\-ssl\-sessions\fP. .IP SSPI SSPI is supported. .IP TLS-SRP SRP (Secure Remote Password) authentication is supported for TLS. .IP Unicode Unicode support on Windows. .IP UnixSockets Unix sockets support is provided. .IP zstd Automatic decompression (via zstd) of compressed files over HTTP is supported. .RE .IP Example: .nf curl --version .fi See also \fI\-\-help\fP and \fI\-\-manual\fP. .IP "\-\-vlan\-priority <priority>" Set VLAN priority as defined in IEEE 802.1Q. This field is set on Ethernet level, and only works within a local network. The valid range for <priority> is 0 to 7. If \fI\-\-vlan\-priority\fP is provided several times, the last set value is used. Example: .nf curl --vlan-priority 4 https://example.com .fi Added in 8.9.0. See also \fI\-\-ip\-tos\fP. .IP "\-w, \-\-write\-out <format>" Make curl display information on stdout after a completed transfer. The format is a string that may contain plain text mixed with any number of variables. The format can be specified as a literal "string", or you can have curl read the format from a file with "@filename" and to tell curl to read the format from stdin you write "@\-". The variables present in the output format are substituted by the value or text that curl thinks fit, as described below. All variables are specified as %{variable_name} and to output a normal % you write them as %%. You can output a newline by using \\n, a carriage return with \\r and a tab space with \\t. The output is by default written to standard output, but can be changed with %{stderr} and %output{}. Output HTTP header values from the transfer\(aqs most recent server response by using \fI%header{name}\fP where \fIname\fP is the case insensitive name of the header (without the trailing colon). The header contents are exactly as delivered over the network but with leading and trailing whitespace and newlines stripped off (added in 7.84.0). Select a specific target destination file to write the output to, by using \fI%output{name}\fP (added in curl 8.3.0) where \fIname\fP is the full filename. The output following that instruction is then written to that file. More than one \fI%output{}\fP instruction can be specified in the same write\-out argument. If the filename cannot be created, curl leaves the output destination to the one used prior to the \fI%output{}\fP instruction. Use \fI%output{>>name}\fP to append data to an existing file. This output is done independently of if the file transfer was successful or not. If the specified action or output specified with this option fails in any way, it does not make curl return a (different) error. \fBNOTE:\fP On Windows, the %\-symbol is a special symbol used to expand environment variables. In batch files, all occurrences of % must be doubled when using this option to properly escape. If this option is used at the command prompt then the % cannot be escaped and unintended expansion is possible. The variables available are: .RS .IP certs Output the certificate chain with details. Supported only by the OpenSSL, GnuTLS, Schannel and Rustls backends. (Added in 7.88.0) .IP conn_id The connection identifier last used by the transfer. The connection id is unique number among all connections using the same connection cache. (Added in 8.2.0) .IP content_type The Content\-Type of the requested document, if there was any. .IP errormsg The error message. (Added in 7.75.0) .IP exitcode The numerical exit code of the transfer. (Added in 7.75.0) .IP filename_effective The ultimate filename that curl writes out to. This is only meaningful if curl is told to write to a file with the \fI\-\-remote\-name\fP or \fI\-\-output\fP option. It is most useful in combination with the \fI\-\-remote\-header\-name\fP option. .IP ftp_entry_path The initial path curl ended up in when logging on to the remote FTP server. .IP header{name} The value of header "name" from the transfer\(aqs most recent server response. Unlike other variables, the variable name "header" is not in braces. For example "%header{date}". Refer to \fI\-\-write\-out\fP remarks. (Added in 7.84.0) Starting with 8.17.0, output the contents of \fIall\fP header fields using a specific name \- even for a whole redirect "chain" by appending \&":all:[separator]" to the header name. The "[separator]" string (if not blank) is output between the headers if there are more than one. When more than one header is shown, they are output in the chronological order of appearance over the wire. To include a close brace ("}") in the separator, escape it with a backslash: "\\}". .IP header_json A JSON object with all HTTP response headers from the recent transfer. Values are provided as arrays, since in the case of multiple headers there can be multiple values. (Added in 7.83.0) The header names provided in lowercase, listed in order of appearance over the wire. Except for duplicated headers. They are grouped on the first occurrence of that header, each value is presented in the JSON array. .IP http_code The numerical response code that was found in the last retrieved HTTP(S) or FTP(s) transfer. .IP http_connect The numerical code that was found in the last response (from a proxy) to a curl CONNECT request. .IP http_version The http version that was effectively used. .IP json A JSON object with all available keys except "header_json". (Added in 7.70.0) .IP local_ip The IP address of the local end of the most recently done connection \- can be either IPv4 or IPv6. .IP local_port The local port number of the most recently done connection. .IP method The http method used in the most recent HTTP request. (Added in 7.72.0) .IP num_certs Number of server certificates received in the TLS handshake. Supported only by the OpenSSL, GnuTLS, Schannel and Rustls backends. (Added in 7.88.0) .IP num_connects Number of new connects made in the recent transfer. .IP num_headers The number of response headers in the most recent request (restarted at each redirect). Note that the status line IS NOT a header. (Added in 7.73.0) .IP num_redirects Number of redirects that were followed in the request. .IP num_retries Number of retries actually performed when "\fI\-\-retry\fP" has been used. (Added in 8.9.0) .IP onerror The rest of the output is only shown if the transfer returned a non\-zero error. (Added in 7.75.0) .IP output{filename} From this point on, the \fI\-\-write\-out\fP output is written to the filename specified in braces. The filename can be prefixed with ">>" to append to the file. Unlike other variables, the variable name "output" is not in braces. For example \&"%output{>>stats.txt}". Refer to \fI\-\-write\-out\fP remarks. (Added in 8.3.0) .IP proxy_ssl_verify_result The result of the HTTPS proxy\(aqs SSL peer certificate verification that was requested. 0 means the verification was successful. .IP proxy_used Returns 1 if the previous transfer used a proxy, otherwise 0. Useful for example to determine if a "NOPROXY" pattern matched the hostname or not. (Added in 8.7.0) .IP redirect_url When an HTTP request was made without \fI\-\-location\fP to follow redirects (or when \fI\-\-max\-redirs\fP is met), this variable shows the actual URL a redirect \fIwould\fP have gone to. .IP referer The Referer: header, if there was any. (Added in 7.76.0) .IP remote_ip The remote IP address of the most recently done connection \- can be either IPv4 or IPv6. .IP remote_port The remote port number of the most recently done connection. .IP response_code The numerical response code that was found in the last transfer (formerly known as "http_code"). .IP scheme The URL scheme (sometimes called protocol) that was effectively used. .IP size_delivered The total amount of data that were saved or written to stdout. When \fI\-\-compressed\fP is used, this is likely different than "size_download". Includes the headers in the count if \fI\-\-include\fP is used. .IP size_download The total amount of bytes that were downloaded. This is the size of the body/data that was transferred, excluding headers. .IP size_header The total amount of bytes of the downloaded headers. .IP size_request The total amount of bytes that were sent in the HTTP request. .IP size_upload The total amount of bytes that were uploaded. This is the size of the body/data that was transferred, excluding headers. .IP speed_download The average download speed that curl measured for the complete download. Bytes per second. .IP speed_upload The average upload speed that curl measured for the complete upload. Bytes per second. .IP ssl_verify_result The result of the SSL peer certificate verification that was requested. 0 means the verification was successful. .IP stderr From this point on, the \fI\-\-write\-out\fP output is written to standard error. .IP stdout From this point on, the \fI\-\-write\-out\fP output is written to standard output. This is the default, but can be used to switch back after switching to stderr. .IP time{format} Output the current UTC time using "strftime()" format. See TIME OUTPUT FORMAT below for details. (Added in 8.16.0) .IP time_appconnect The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed. .IP time_connect The time, in seconds, it took from the start until the TCP connect to the remote host (or proxy) was completed. .IP time_namelookup The time, in seconds, it took from the start until the name resolving was completed. .IP time_posttransfer The time, in seconds, it took from the start until the last byte is sent by libcurl. (Added in 8.10.0) .IP time_pretransfer The time, in seconds, it took from the start until immediately before the file transfer was about to begin. This includes all pre\-transfer commands and negotiations that are specific to the particular protocol(s) involved. .IP time_queue The time, in seconds, the transfer was queued during its run. This adds the queue time for each redirect step that may have happened. Transfers may be queued for significant amounts of time when connection or parallel limits are in place. (Added in 8.12.0) .IP time_redirect The time, in seconds, it took for all redirection steps including name lookup, connect, pretransfer and transfer before the final transaction was started. "time_redirect" shows the complete execution time for multiple redirections. .IP time_starttransfer The time, in seconds, it took from the start until the first byte was received. This includes time_pretransfer and also the time the server needed to calculate the result. .IP time_total The total time, in seconds, that the full operation lasted. .IP tls_earlydata The amount of bytes that were sent as TLSv1.3 early data. This is 0 if this TLS feature was not used and negative if the data sent had been rejected by the server. The use of early data is enabled via the command line option "\fI\-\-tls\-earlydata\fP". (Added in 8.13.0) .IP url The URL that was fetched. (Added in 7.75.0) .IP url.scheme The scheme part of the URL that was fetched. (Added in 8.1.0) .IP url.user The user part of the URL that was fetched. (Added in 8.1.0) .IP url.password The password part of the URL that was fetched. (Added in 8.1.0) .IP url.options The options part of the URL that was fetched. (Added in 8.1.0) .IP url.host The host part of the URL that was fetched. (Added in 8.1.0) .IP url.port The port number of the URL that was fetched. If no port number was specified and the URL scheme is known, that scheme\(aqs default port number is shown. (Added in 8.1.0) .IP url.path The path part of the URL that was fetched. (Added in 8.1.0) .IP url.query The query part of the URL that was fetched. (Added in 8.1.0) .IP url.fragment The fragment part of the URL that was fetched. (Added in 8.1.0) .IP url.zoneid The zone id part of the URL that was fetched. (Added in 8.1.0) .IP urle.scheme The scheme part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.user The user part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.password The password part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.options The options part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.host The host part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.port The port number of the effective (last) URL that was fetched. If no port number was specified, but the URL scheme is known, that scheme\(aqs default port number is shown. (Added in 8.1.0) .IP urle.path The path part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.query The query part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.fragment The fragment part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urle.zoneid The zone id part of the effective (last) URL that was fetched. (Added in 8.1.0) .IP urlnum The URL index number of this transfer, 0\-indexed. Unglobbed URLs share the same index number as the origin globbed URL. (Added in 7.75.0) .IP url_effective The URL that was fetched last. This is most meaningful if you have told curl to follow location: headers. .IP xfer_id The numerical identifier of the last transfer done. \-1 if no transfer has been started yet for the handle. The transfer id is unique among all transfers performed using the same connection cache. (Added in 8.2.0) .RE .IP TIME OUTPUT FORMAT To show time with "%time{}" the characters within "{}" create a special format string that may contain special character sequences called conversion specifications. Each conversion specification starts with "%" and is followed by a character that instructs curl to output a particular time detail. All other characters used are displayed as\-is. The following conversion specification are available: .RS .IP %a The abbreviated name of the day of the week according to the current locale. .IP %A The full name of the day of the week according to the current locale. .IP %b The abbreviated month name according to the current locale. .IP %B The full month name according to the current locale. .IP %c The preferred date and time representation for the current locale. (In the POSIX locale this is equivalent to "%a %b %e %H:%M:%S %Y".) .IP %C The century number (year/100) as a 2\-digit integer. .IP %d The day of the month as a decimal number (range 01 to 31). .IP %D Equivalent to "%m/%d/%y". In international contexts, this format is ambiguous and should be avoided.) .IP %e Like "%d", the day of the month as a decimal number, but a leading zero is replaced by a space. .IP %f The number of microseconds elapsed of the current second. (This a curl special code and not a standard one.) .IP %F Equivalent to "%Y\-%m\-%d" (the ISO 8601 date format). .IP %G The ISO 8601 week\-based year with century as a decimal number. The 4\-digit year corresponding to the ISO week number (see "%V"). This has the same format and value as "%Y", except that if the ISO week number belongs to the previous or next year, that year is used instead. .IP %g Like "%G", but without century, that is, with a 2\-digit year (00\-99). .IP %h Equivalent to "%b". .IP %H The hour as a decimal number using a 24\-hour clock (range 00 to 23). .IP %I The hour as a decimal number using a 12\-hour clock (range 01 to 12). .IP %j The day of the year as a decimal number (range 001 to 366). .IP %k The hour (24\-hour clock) as a decimal number (range 0 to 23); single digits are preceded by a blank. .IP %l The hour (12\-hour clock) as a decimal number (range 1 to 12); single digits are preceded by a blank. .IP %m The month as a decimal number (range 01 to 12). .IP %M The minute as a decimal number (range 00 to 59). .IP %p Either "AM" or "PM" according to the given time value, or the corresponding strings for the current locale. Noon is treated as "PM" and midnight as "AM". .IP %P Like "%p" but in lowercase: "am" or "pm" or a corresponding string for the current locale. .IP %r The time in am or pm notation. .IP %R The time in 24\-hour notation ("%H:%M"). For a version including the seconds, see "%T" below. .IP %s The number of seconds since the Epoch, 1970\-01\-01 00:00:00 +0000 (UTC). .IP %S The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds.) See "%f" for microseconds. .IP %T The time in 24\-hour notation ("%H:%M:%S"). .IP %u The day of the week as a decimal, range 1 to 7, Monday being 1. .IP %U The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01. See also "%V" and \&"%W". .IP %V The ISO 8601 week number (see NOTES) of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the new year. See also "%U" and "%W". .IP %w The day of the week as a decimal, range 0 to 6, Sunday being 0. See also "%u". .IP %W The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01. .IP %x The preferred date representation for the current locale without the time. .IP %X The preferred time representation for the current locale without the date. .IP %y The year as a decimal number without a century (range 00 to 99). .IP %Y The year as a decimal number including the century. .IP %z The "+hhmm" or "\-hhmm" numeric timezone (that is, the hour and minute offset from UTC). As time is always UTC, this outputs "+0000". .IP %Z The timezone name. For some reason "GMT". .IP %% A literal "%" character. .RE .IP If \fI\-\-write\-out\fP is provided several times, the last set value is used. Example: .nf curl -w '%{response_code}\\n' https://example.com .fi See also \fI\-\-verbose\fP and \fI\-\-head\fP. .IP "\-\-xattr" Store metadata in the extended file attributes. When saving output to a file, tell curl to store file metadata in extended file attributes. Currently, "curl" is stored in the "creator" attribute, the URL is stored in the "xdg.origin.url" attribute and, for HTTP, the content type is stored in the "mime_type" attribute. If the file system does not support extended attributes, a warning is issued. Providing \fI\-\-xattr\fP multiple times has no extra effect. Disable it again with \-\-no-xattr. Example: .nf curl --xattr -o storage https://example.com .fi See also \fI\-\-remote\-time\fP, \fI\-\-write\-out\fP and \fI\-\-verbose\fP. .SH FILES \fI~/.curlrc\fP Default config file, see \fI\-\-config\fP for details. .SH ENVIRONMENT The environment variables can be specified in lower case or upper case. The lower case version has precedence. "http_proxy" is an exception as it is only available in lower case. Using an environment variable to set the proxy has the same effect as using the \fI\-\-proxy\fP option. .IP "http_proxy [protocol://]<host>[:port]" Sets the proxy server to use for HTTP. .IP "HTTPS_PROXY [protocol://]<host>[:port]" Sets the proxy server to use for HTTPS. .IP "[url-protocol]_PROXY [protocol://]<host>[:port]" Sets the proxy server to use for [url\-protocol], where the protocol is a protocol that curl supports and as specified in a URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP, etc. .IP "ALL_PROXY [protocol://]<host>[:port]" Sets the proxy server to use if no protocol\-specific proxy is set. .IP "NO_PROXY <comma-separated list of hosts/domains>" list of hostnames that should not go through any proxy. If set to an asterisk \(aq*\(aq only, it matches all hosts. Each name in this list is matched as either a domain name which contains the hostname, or the hostname itself. This environment variable disables use of the proxy even when specified with the \fI\-\-proxy\fP option. That is .nf NO_PROXY=direct.example.com curl \-x http://proxy.example.com https://direct.example.com .fi accesses the target URL directly, and .nf NO_PROXY=direct.example.com curl \-x http://proxy.example.com https://somewhere.example.com .fi accesses the target URL through the proxy. The list of hostnames can also include numerical IP addresses, and IPv6 versions should then be given without enclosing brackets. IP addresses can be specified using CIDR notation: an appended slash and number specifies the number of "network bits" out of the address to use in the comparison (added in 7.86.0). For example "192.168.0.0/16" would match all addresses starting with "192.168". .IP "APPDATA <directory>" On Windows, this variable is used when trying to find the home directory. If the primary home variables are all unset. .IP "COLUMNS <terminal width>" If set, the specified number of characters is used as the terminal width when the alternative progress\-bar is shown. If not set, curl tries to figure it out using other ways. .IP "CURL_CA_BUNDLE <file>" If set, it is used as the \fI\-\-cacert\fP value. This environment variable is ignored if Schannel is used as the TLS backend. .IP "CURL_HOME <directory>" If set, is the first variable curl checks when trying to find its home directory. If not set, it continues to check \fIXDG_CONFIG_HOME\fP .IP "CURL_SSL_BACKEND <TLS backend>" If curl was built with support for "MultiSSL", meaning that it has built\-in support for more than one TLS backend, this environment variable can be set to the case insensitive name of the particular backend to use when curl is invoked. Setting a name that is not a built\-in alternative makes curl stay with the default. SSL backend names (case\-insensitive): \fBgnutls\fP, \fBmbedtls\fP, \fBopenssl\fP, \fBrustls\fP, \fBschannel\fP, \fBwolfssl\fP .IP "HOME <directory>" If set, this is used to find the home directory when that is needed. Like when looking for the default .curlrc. \fICURL_HOME\fP and \fIXDG_CONFIG_HOME\fP have preference. .IP "NETRC <path>" If set, this is used to find the ".netrc" file. It overrides all other netrc file location mechanisms and should be set to the full file path. (Added in curl 8.16.0) .IP "QLOGDIR <directory>" If curl was built with HTTP/3 support, setting this environment variable to a local directory makes curl produce \fBqlogs\fP in that directory, using file names named after the destination connection id (in hex). Do note that these files can become rather large. Works with the ngtcp2 and quiche QUIC backends. .IP SHELL Used on VMS when trying to detect if using a \fBDCL\fP or a \fBUnix\fP shell. .IP "SSL_CERT_DIR <directory>" If set, it is used as the \fI\-\-capath\fP value. This environment variable is ignored if Schannel is used as the TLS backend. .IP "SSL_CERT_FILE <path>" If set, it is used as the \fI\-\-cacert\fP value. This environment variable is ignored if Schannel is used as the TLS backend. .IP "SSLKEYLOGFILE <path>" If you set this environment variable to a filename, curl stores TLS secrets from its connections in that file when invoked to enable you to analyze the TLS traffic in real time using network analyzing tools such as Wireshark. This works with the following TLS backends: OpenSSL, LibreSSL (TLS 1.2 max), BoringSSL, GnuTLS, wolfSSL and Rustls. .IP "USERPROFILE <directory>" On Windows, this variable is used when trying to find the home directory. If the other, primary, variables are all unset. If set, curl uses the path \fB"$USERPROFILE\\Application Data"\fP. .IP "XDG_CONFIG_HOME <directory>" If \fICURL_HOME\fP is not set, this variable is checked when looking for a default .curlrc file. .SH PROXY PROTOCOL PREFIXES The proxy string may be specified with a protocol:// prefix to specify alternative proxy protocols. If no protocol is specified in the proxy string or if the string does not match a supported one, the proxy is treated as an HTTP proxy. The supported proxy protocol prefixes are as follows: .IP http:// Makes it use it as an HTTP proxy. The default if no scheme prefix is used. .IP https:// Makes it treated as an \fBHTTPS\fP proxy. .IP socks4:// Makes it the equivalent of \fI\-\-socks4\fP .IP socks4a:// Makes it the equivalent of \fI\-\-socks4a\fP .IP socks5:// Makes it the equivalent of \fI\-\-socks5\fP .IP socks5h:// Makes it the equivalent of \fI\-\-socks5\-hostname\fP .SH EXIT CODES There are a bunch of different error codes and their corresponding error messages that may appear under error conditions. At the time of this writing, the exit codes are: .IP 0 Success. The operation completed successfully according to the instructions. .IP 1 Unsupported protocol. This build of curl has no support for this protocol. .IP 2 Failed to initialize. .IP 3 URL malformed. The syntax was not correct. .IP 4 A feature or option that was needed to perform the desired request was not enabled or was explicitly disabled at build\-time. To make curl able to do this, you probably need another build of libcurl. .IP 5 Could not resolve proxy. The given proxy host could not be resolved. .IP 6 Could not resolve host. The given remote host could not be resolved. .IP 7 Failed to connect to host. .IP 8 Weird server reply. The server sent data curl could not parse. .IP 9 FTP access denied. The server denied login or denied access to the particular resource or directory you wanted to reach. Most often you tried to change to a directory that does not exist on the server. .IP 10 FTP accept failed. While waiting for the server to connect back when an active FTP session is used, an error code was sent over the control connection or similar. .IP 11 FTP weird PASS reply. curl could not parse the reply sent to the PASS request. .IP 12 During an active FTP session while waiting for the server to connect back to curl, the timeout expired. .IP 13 FTP weird PASV reply, curl could not parse the reply sent to the PASV request. .IP 14 FTP weird 227 format. curl could not parse the 227\-line the server sent. .IP 15 FTP cannot use host. Could not resolve the host IP we got in the 227\-line. .IP 16 HTTP/2 error. A problem was detected in the HTTP2 framing layer. This is somewhat generic and can be one out of several problems, see the error message for details. .IP 17 FTP could not set binary. Could not change transfer method to binary. .IP 18 Partial file. Only a part of the file was transferred. .IP 19 FTP could not download/access the given file, the RETR (or similar) command failed. .IP 21 FTP quote error. A quote command returned error from the server. .IP 22 HTTP page not retrieved. The requested URL was not found or returned another error with the HTTP error code being 400 or above. This return code only appears if \fI\-\-fail\fP is used. .IP 23 Write error. curl could not write data to a local file system or similar. .IP 25 Failed starting the upload. For FTP, the server typically denied the STOR command. .IP 26 Read error. Various reading problems. .IP 27 Out of memory. A memory allocation request failed. .IP 28 Operation timeout. The specified time\-out period was reached according to the conditions. .IP 30 FTP PORT failed. The PORT command failed. Not all FTP servers support the PORT command, try doing a transfer using PASV instead. .IP 31 FTP could not use REST. The REST command failed. This command is used for resumed FTP transfers. .IP 33 HTTP range error. The range "command" did not work. .IP 34 HTTP post error. Internal post\-request generation error. .IP 35 SSL connect error. The SSL handshaking failed. .IP 36 Bad download resume. Could not continue an earlier aborted download. .IP 37 FILE could not read file. Failed to open the file. Permissions? .IP 38 LDAP cannot bind. LDAP bind operation failed. .IP 39 LDAP search failed. .IP 41 Function not found. A required LDAP function was not found. .IP 42 Aborted by callback. An application told curl to abort the operation. .IP 43 Internal error. A function was called with a bad parameter. .IP 45 Interface error. A specified outgoing interface could not be used. .IP 47 Too many redirects. When following redirects, curl hit the maximum amount. .IP 48 Unknown option specified to libcurl. This indicates that you passed a weird option to curl that was passed on to libcurl and rejected. Read up in the manual. .IP 49 Malformed telnet option. .IP 52 The server did not reply anything, which here is considered an error. .IP 53 SSL crypto engine not found. .IP 54 Cannot set SSL crypto engine as default. .IP 55 Failed sending network data. .IP 56 Failure in receiving network data. .IP 58 Problem with the local certificate. .IP 59 Could not use specified SSL cipher. .IP 60 Peer certificate cannot be authenticated with known CA certificates. .IP 61 Unrecognized transfer encoding. .IP 63 Maximum file size exceeded. .IP 64 Requested FTP SSL level failed. .IP 65 Sending the data requires a rewind that failed. .IP 66 Failed to initialize SSL Engine. .IP 67 The username, password, or similar was not accepted and curl failed to log in. .IP 68 File not found on TFTP server. .IP 69 Permission problem on TFTP server. .IP 70 Out of disk space on TFTP server. .IP 71 Illegal TFTP operation. .IP 72 Unknown TFTP transfer ID. .IP 73 File already exists (TFTP). .IP 74 No such user (TFTP). .IP 77 Problem reading the SSL CA cert (path? access rights?). .IP 78 The resource referenced in the URL does not exist. .IP 79 An unspecified error occurred during the SSH session. .IP 80 Failed to shut down the SSL connection. .IP 82 Could not load CRL file, missing or wrong format. .IP 83 Issuer check failed. .IP 84 The FTP PRET command failed. .IP 85 Mismatch of RTSP CSeq numbers. .IP 86 Mismatch of RTSP Session Identifiers. .IP 87 Unable to parse FTP file list. .IP 88 FTP chunk callback reported error. .IP 89 No connection available, the session is queued. .IP 90 SSL public key does not match pinned public key. .IP 91 Invalid SSL certificate status. .IP 92 Stream error in HTTP/2 framing layer. .IP 93 An API function was called from inside a callback. .IP 94 An authentication function returned an error. .IP 95 A problem was detected in the HTTP/3 layer. This is somewhat generic and can be one out of several problems, see the error message for details. .IP 96 QUIC connection error. This error may be caused by an SSL library error. QUIC is the protocol used for HTTP/3 transfers. .IP 97 Proxy handshake error. .IP 98 A client\-side certificate is required to complete the TLS handshake. .IP 99 Poll or select returned fatal error. .IP 100 A value or data field grew larger than allowed. .IP XX More error codes might appear here in future releases. The existing ones are meant to never change. .SH BUGS If you experience any problems with curl, submit an issue in the project\(aqs bug tracker on GitHub: https://github.com/curl/curl/issues .SH AUTHORS Daniel Stenberg is the main author, but the whole list of contributors is found in the separate THANKS file. .SH WWW https://curl.se/ .SH SEE ALSO \fBftp(1)\fP, \fBwget(1)\fP
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