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Editing: popen-c.yaml
--- !ruby/object:RI::MethodDescription aliases: [] block_params: comment: - !ruby/struct:SM::Flow::P body: Runs the specified command string as a subprocess; the subprocess's standard input and output will be connected to the returned <tt>IO</tt> object. If <em>cmd_string</em> starts with a ``<tt>-</tt>'', then a new instance of Ruby is started as the subprocess. The default mode for the new file object is ``r'', but <em>mode</em> may be set to any of the modes listed in the description for class IO. - !ruby/struct:SM::Flow::P body: If a block is given, Ruby will run the command as a child connected to Ruby with a pipe. Ruby's end of the pipe will be passed as a parameter to the block. At the end of block, Ruby close the pipe and sets <tt>$?</tt>. In this case <tt>IO::popen</tt> returns the value of the block. - !ruby/struct:SM::Flow::P body: "If a block is given with a <em>cmd_string</em> of ``<tt>-</tt>'', the block will be run in two separate processes: once in the parent, and once in a child. The parent process will be passed the pipe object as a parameter to the block, the child version of the block will be passed <tt>nil</tt>, and the child's standard in and standard out will be connected to the parent through the pipe. Not available on all platforms." - !ruby/struct:SM::Flow::VERB body: " f = IO.popen("uname")\n p f.readlines\n puts "Parent is #{Process.pid}"\n IO.popen ("date") { |f| puts f.gets }\n IO.popen("-") {|f| $stderr.puts "#{Process.pid} is here, f is #{f}"}\n p $?\n" - !ruby/struct:SM::Flow::P body: <em>produces:</em> - !ruby/struct:SM::Flow::VERB body: " ["Linux\\n"]\n Parent is 26166\n Wed Apr 9 08:53:52 CDT 2003\n 26169 is here, f is\n 26166 is here, f is #<IO:0x401b3d44>\n #<Process::Status: pid=26166,exited(0)>\n" full_name: IO::popen is_singleton: true name: popen params: | IO.popen(cmd_string, mode="r" ) => io IO.popen(cmd_string, mode="r" ) {|io| block } => obj visibility: public
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