proc_open() is similar to
popen() but provides a much greater degree of control
over the program execution.
cmd is the command to be executed by the shell. descriptorspec is an indexed
array where the key represents the descriptor number and the
value represents how PHP will pass that descriptor to the
child process. pipes will
be set to an indexed array of file pointers that correspond
to PHP's end of any pipes that are created. The return value
is a resource representing the process; you should free it
using
proc_close() when you are finished with it.
$descriptorspec = array( 0 = array("pipe", "r"), // stdin is a pipe that the child will read from 1 = array("pipe", "w"), // stdout is a pipe that the child will write to 2 = array("file", "/tmp/error-output.txt", "a"), // stderr is a file to write to ); $process = proc_open("php", $descriptorspec, $pipes); if (is_resource($process)) { // $pipes now looks like this: // 0 = writeable handle connected to child stdin // 1 = readable handle connected to child stdout // Any error output will be appended to /tmp/error-output.txt fwrite($pipes[0], " ?php echo \"Hello World!\"; ? "); fclose($pipes[0]); while(!feof($pipes[1])) { echo fgets($pipes[1], 1024); } fclose($pipes[1]); // It is important that you close any pipes before calling // proc_close in order to avoid a deadlock $return_value = proc_close($process); echo "command returned $return_value\n"; } |
The file descriptor numbers in
descriptorspec are not limited to 0, 1 and 2 - you
may specify any valid file descriptor number and it will be
passed to the child process. This allows your script to
interoperate with other scripts that run as "co-processes".
In particular, this is useful for passing passphrases to
programs like PGP, GPG and openssl in a more secure manner.
It is also useful for reading status information provided by
those programs on auxillary file descriptors.
注: Windows compatibility: Descriptors beyond 2 (stderr) are made available to the child process as inheritable handles, but since the Windows architecture does not associate file descriptor numbers with low-level handles, the child process does not (yet) have a means of accessing those handles. Stdin, stdout and stderr work as expected.
注: This function was introduced in PHP 4.3.0.
注: If you only need a uni-directional (one-way) process pipe, use popen() instead, as it is much easier to use.
See also exec(), system(),
passthru(), popen(),
escapeshellcmd(), and the backtick
operator.