Util_Process

General PHP process management utility

What it does

Util_Process ("UP") provides a flexible process wrapper around command execution. It's used extensively in our control panel, apnscp, to provide a coherent process execution interface. UP includes support for variadic arguments, named arguments (%(name)s), and back references (%1$s).

Components

UP consists of:

• a basic process driver (Util_Process)
• chroot driver (Util_Process_Chroot)
• forking processes (Util_Process_Fork)
• untrusted argument input (Util_Process_Safe)
• scheduled background tasks via at (Util_Process_Schedule)
• sudo execution (Util_Process_Sudo)
• teed output + persistence - will need some hacking to adapt, part of apnscp - (Util_Process_Tee)

Examples

Standard program

<?php
  include("Util/Process.php");
  $proc = Util_Process::exec("echo %s", "Hello World!");
?>

Escaping unsafe arguments

<?php  
	include("Util/Process.php");
	include("Util/Process/Safe.php");
	$proc = Util_Process_Safe::exec("echo %s %s", '"Hello World\\!(;', ':(){ :|: & };:');
	print $proc['stdout'];
?>

Using named arguments

<?php
	include("Util/Process.php");
	$proc = Util_Process::exec(
		"ls %(flags)s %(path)s",
		array(
			'flags' => '-latr',
		    'path' => '/'
		)
	);
	print $proc['stdout'];
?>

Sending a program to background

<?php
	include("Util/Process.php");
	include("Util/Process/Fork.php");
	$proc = Util_Process_Fork::exec(
		"/bin/touch %s",
		tempnam(sys_get_temp_dir(), 'util-process')
	);
	
	print $proc['stdout'];
	print $proc['success'] === true; 
?>

Scheduling a task

In this example, at is used to handle program execution.

<?php
	include("Util/Process.php");
	include("Util/Process/Safe.php");
	include("Util/Process/Schedule.php");
	$proc = new Util_Process_Schedule("5 minutes");
	$ret = $proc->run(
		"/bin/touch %s",
		tempnam(sys_get_temp_dir(), 'util-process')
	);

	print $ret['stdout'];
?>

Todo

• Fully implement pipe support (not working yet)
• Refactor stream implementation, ~25%-40% slower than shell execution