A simple OS class that helps PHP run commands on the command line.

OS.php

<?php

/**
 *  The `OS` class helps run 
 *  commands on the command line.
 *
 *  @author JT Paasch
 */
class OS {

    /**
     *  Run a command on the command line.
     *
     *  @access public
     *  @param String $command The command to run (include param/options).
     *  @param String $input The input to give to the command (if any).
     *  @return Array The results with 'output', 'error', and 'code'.
     */
    public static function run($command, $input=null) {

        // Let's identify the streams/pipes we want to use. 
        // We want STDIN (0), STDOUT (1), and STDERR (2).
        $interface = array(
            0 => array('pipe', 'r'), // STDIN reads what we give it.
            1 => array('pipe', 'w'), // STDOUT writes to the stream.
            2 => array('pipe', 'w'), // STDERR writes to the stream.
        ); 

        // Open the process. After this, We'll be able to access 
        // the pipes/streams through the $pipe array.
        // That is, $pipe[0] will access $interface[0], 
        // $pipe[1] will access $interface[1], and so on.
        $process = proc_open($command, $interface, $pipe);
 
        // If we need to give the command some input, do so now:
        if (!empty($input)) {
            fwrite($pipe[0], $input);
        }

        // Close the input stream, so the command knows it can go ahead.
        fclose($pipe[0]);

        // Read the STDOUT and STDERR pipes.
        $output = @stream_get_contents($pipe[1]);
        $error = @stream_get_contents($pipe[2]);

        // Close the STDOUT and STDERR pipes.
        fclose($pipe[1]);
        fclose($pipe[2]);

        // Close the process.
        $exit_code = proc_close($process);

        // Return the results.
        return array(
            'output' => $output,
            'error' => $error,
            'code' => $exit_code,
        );

    }

}