3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php echo file_get_contents(system('whoami')); ?>
Output for 5.2.9 - 7.2.0
Warning: file_get_contents(): Filename cannot be empty in /in/kLLug on line 2
Output for 4.3.0 - 5.2.8