3v4l.org

run code in 300+ PHP versions simultaneously
<?php $str = "127.0.0.1 domain.com #this is a comment"; preg_match('/^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})[ \t]+([^ #]+).+$/',$str,$arr); print_R($arr);

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37.52 ms | 402 KiB | 5 Q