3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(`which php`);
Output for 5.4.44 - 7.2.0
NULL
Output for 5.4.39 - 5.4.43
NULL /usr/bin/which: 3: exec: echo: not found
Output for 5.0.0 - 5.4.38
NULL sh: 1: which: not found
Output for 4.3.1 - 4.4.9
string(0) "" sh: 1: which: not found
Output for 4.3.0
string(0) ""