3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $c = " total used free shared buffers cached\nMem: 494 383 111 0 29 200\n-/+ buffers/cache: 153 341\nSwap: 255 0 255"; preg_match("/Mem:\s+(?<total>\d+)/", $c ,$r); print_r($r);
Output for 4.4.6 - 4.4.9, 5.2.2 - 7.1.0
Array ( [0] => Mem: 494 [total] => 494 [1] => 494 )
Output for 5.2.0 - 5.2.1
Warning: preg_match(): Compilation failed: unrecognized character after (?< at offset 10 in /in/K7eFo on line 4
Output for 4.3.11 - 4.4.5, 5.0.0 - 5.1.6
Warning: preg_match(): Compilation failed: unrecognized character after (?< at offset 10 in /in/K7eFo on line 4 Array ( )
Output for 4.3.0 - 4.3.10
Warning: Compilation failed: unrecognized character after (?< at offset 10 in /in/K7eFo on line 4 Array ( )