shell.php

<?php
$cmd = 'date';
$desc = array(
    0 => array('pipe', 'r'),
    1 => array('pipe', 'w'),
    2 => array('pipe', 'w')
);
$pwd = '~';
$env = array();

$proc = @proc_open($cmd, $desc, $pipes, $pwd, $env);
if ( is_resource($proc)) {
    #fwrite($pipes[0], 'stdin');
    fclose($pipes[0]);
    $p1 = stream_get_contents($pipes[1]);
    fclose($pipes[1]);
    $p2 = stream_get_contents($pipes[2]);
    fclose($pipes[2]);
    proc_close($proc);
    print 'stdout: ' . $p1;
    print 'stderr: ' . $p2 . "\n";
} else {
    print "error.";
}
?>