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<?xml version="1.0" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>BIO_s_fd</title> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <link rev="made" href="mailto:root@localhost" /> </head> <body> <ul id="index"> <li><a href="#NAME">NAME</a></li> <li><a href="#SYNOPSIS">SYNOPSIS</a></li> <li><a href="#DESCRIPTION">DESCRIPTION</a></li> <li><a href="#NOTES">NOTES</a></li> <li><a href="#RETURN-VALUES">RETURN VALUES</a></li> <li><a href="#EXAMPLES">EXAMPLES</a></li> <li><a href="#SEE-ALSO">SEE ALSO</a></li> <li><a href="#COPYRIGHT">COPYRIGHT</a></li> </ul> <h1 id="NAME">NAME</h1> <p>BIO_s_fd, BIO_set_fd, BIO_get_fd, BIO_new_fd - file descriptor BIO</p> <h1 id="SYNOPSIS">SYNOPSIS</h1> <pre><code> #include <openssl/bio.h> const BIO_METHOD *BIO_s_fd(void); int BIO_set_fd(BIO *b, int fd, int c); int BIO_get_fd(BIO *b, int *c); BIO *BIO_new_fd(int fd, int close_flag);</code></pre> <h1 id="DESCRIPTION">DESCRIPTION</h1> <p>BIO_s_fd() returns the file descriptor BIO method. This is a wrapper round the platforms file descriptor routines such as read() and write().</p> <p>BIO_read_ex() and BIO_write_ex() read or write the underlying descriptor. BIO_puts() is supported but BIO_gets() is not.</p> <p>If the close flag is set then close() is called on the underlying file descriptor when the BIO is freed.</p> <p>BIO_reset() attempts to change the file pointer to the start of file such as by using <b>lseek(fd, 0, 0)</b>.</p> <p>BIO_seek() sets the file pointer to position <b>ofs</b> from start of file such as by using <b>lseek(fd, ofs, 0)</b>.</p> <p>BIO_tell() returns the current file position such as by calling <b>lseek(fd, 0, 1)</b>.</p> <p>BIO_set_fd() sets the file descriptor of BIO <b>b</b> to <b>fd</b> and the close flag to <b>c</b>.</p> <p>BIO_get_fd() places the file descriptor in <b>c</b> if it is not NULL, it also returns the file descriptor.</p> <p>BIO_new_fd() returns a file descriptor BIO using <b>fd</b> and <b>close_flag</b>.</p> <h1 id="NOTES">NOTES</h1> <p>The behaviour of BIO_read_ex() and BIO_write_ex() depends on the behavior of the platforms read() and write() calls on the descriptor. If the underlying file descriptor is in a non blocking mode then the BIO will behave in the manner described in the <a href="../man3/BIO_read_ex.html">BIO_read_ex(3)</a> and <a href="../man3/BIO_should_retry.html">BIO_should_retry(3)</a> manual pages.</p> <p>File descriptor BIOs should not be used for socket I/O. Use socket BIOs instead.</p> <p>BIO_set_fd() and BIO_get_fd() are implemented as macros.</p> <h1 id="RETURN-VALUES">RETURN VALUES</h1> <p>BIO_s_fd() returns the file descriptor BIO method.</p> <p>BIO_set_fd() always returns 1.</p> <p>BIO_get_fd() returns the file descriptor or -1 if the BIO has not been initialized.</p> <p>BIO_new_fd() returns the newly allocated BIO or NULL is an error occurred.</p> <h1 id="EXAMPLES">EXAMPLES</h1> <p>This is a file descriptor BIO version of "Hello World":</p> <pre><code> BIO *out; out = BIO_new_fd(fileno(stdout), BIO_NOCLOSE); BIO_printf(out, "Hello World\n"); BIO_free(out);</code></pre> <h1 id="SEE-ALSO">SEE ALSO</h1> <p><a href="../man3/BIO_seek.html">BIO_seek(3)</a>, <a href="../man3/BIO_tell.html">BIO_tell(3)</a>, <a href="../man3/BIO_reset.html">BIO_reset(3)</a>, <a href="../man3/BIO_read_ex.html">BIO_read_ex(3)</a>, <a href="../man3/BIO_write_ex.html">BIO_write_ex(3)</a>, <a href="../man3/BIO_puts.html">BIO_puts(3)</a>, <a href="../man3/BIO_gets.html">BIO_gets(3)</a>, <a href="../man3/BIO_printf.html">BIO_printf(3)</a>, <a href="../man3/BIO_set_close.html">BIO_set_close(3)</a>, <a href="../man3/BIO_get_close.html">BIO_get_close(3)</a></p> <h1 id="COPYRIGHT">COPYRIGHT</h1> <p>Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.</p> <p>Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p> </body> </html>
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