3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php system("echo $_"); ?>
Output for 5.6.28, 7.0.14 - 7.1.0
Notice: Undefined variable: _ in /in/hliNE on line 1
Output for 5.0.4 - 5.6.25, 7.0.0 - 7.0.10
Notice: Undefined variable: _ in /in/hliNE on line 1 Warning: system(): Unable to fork [echo ] in /in/hliNE on line 1
Output for hhvm-3.10.0 - 3.12.0
Notice: Undefined variable: _ in /in/hliNE on line 1 Failed to exec: `echo '
Output for 4.3.2 - 5.0.3
Notice: Undefined variable: _ in /in/hliNE on line 1 Warning: system(): Unable to fork [echo ] in /in/hliNE on line 1
Output for 4.3.0 - 4.3.1
Notice: Undefined variable: _ in /in/hliNE on line 1 Warning: system() [http://www.php.net/function.system]: Unable to fork [echo ] in /in/hliNE on line 1