proc_open() is similar to popen() but provides a much greater degree of control over the program execution.
The command to execute
An indexed array where the key represents the descriptor number and the value represents how PHP will pass that descriptor to the child process. 0 is stdin, 1 is stdout, while 2 is stderr.
The currently supported pipe types are file and pipe .
The file descriptor numbers 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 auxiliary file descriptors.
Will be set to an indexed array of file pointers that correspond to PHP's end of any pipes that are created.
The initial working dir for the command. This must be an absolute directory path, or NULL if you want to use the default value (the working dir of the current PHP process)
An array with the environment variables for the command that will be run, or NULL to use the same environment as the current PHP process
Allows you to specify additional options. Currently supported options include:
|suppress_errors (windows only): suppresses errors generated by this function when it's set to TRUE|
|bypass_shell (windows only): bypass cmd.exe shell when set to TRUE|
|context: stream context used when opening files (created with stream_context_create())|
|binary_pipes: open pipes in binary mode, instead of using the usual stream_encoding|
Returns a resource representing the process, which should be freed using proc_close() when you are finished with it. On failure returns FALSE.
Example 1. A proc_open() example
The above example will output something similar to:
Note: 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.
Note: If you only need a uni-directional (one-way) process pipe, use popen() instead, as it is much easier to use.