3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php system("cat /proc/version"); ?>
Output for 5.5.24 - 7.1.0
Output for 4.3.2 - 5.4.45
Warning: system(): Unable to fork [cat /proc/version] in /in/miX5H on line 2
Output for 4.3.0 - 4.3.1
Warning: system() [http://www.php.net/function.system]: Unable to fork [cat /proc/version] in /in/miX5H on line 2