Pollinimini.net

PHP offers multiple methods to execute external applications, for simple things they are more than enough but sometimes we need more flexibility. The following class acts as a wrapper around proc_open.

It implements a fluent interface to ease its configuration and non-blocking pipes for stdout and stderr. The output can be obtained at the end of the program execution or incrementally by using a callback function.

<?php
$cmd = Command::factory('/usr/bin/svn');
$cmd->option('--username', 'drslump')
    ->option('-r', 'HEAD')
    ->option('log')
    ->argument('http://code.google.com/drslump/trunk');
    ->run();
if ($cmd->getExitCode() === 0) {
    echo $cmd->getStdOut();
} else {
    echo $cmd->getStdErr();
}

Incremental updates can be accomplished with a callback function, like in the following example (PHP 5.3+):

<?php
$cmd = Command::factory('ls');
$cmd->setCallback(function($pipe, $data){
        if ($pipe === Command::STDOUT) echo 'STDOUT: ';
        if ($pipe === Command::STDERR) echo 'STDERR: ';
        echo $data === NULL ? "EOF\n" : "$data\n";
        // If we return "false" all pipes will be closed
        // return false;
    })
    ->setDirectory('/tmp')
    ->option('-l')
    ->run();
if ($cmd->getExitCode() === 0) {
    echo $cmd->getStdOut();
} else {
    echo $cmd->getStdErr();
}

Some more features:

• StdIn data can be provided to the process as a parameter to run()
• Set environment variables for the process with setEnv()
• Second argument to option() and argument to argument() are automatically escaped.
• Options separator is white space by default, it can be changed by manually setting it as third argument to option() or setting a new default with setOptionSeparator().
• The proc_open wrapper is exposed as a static method for your convenience Command::exec()

And finally the class which makes all that possible :)