3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php var_dump(`$`);
Output for 5.0.0 - 7.1.7, 7.2.0
NULL
Output for 7.1.10

Process exited with code 137.
Output for 4.3.0 - 4.4.9
string(0) ""