$re = '/(.+?)([0-9]+)\s\[m.+/m';
$str = '2019 May 22 03:32:17.952296 france1v4 sh[4937]: 190522-03:32:17.951792 [mod=REC, lvl=INFO] [tid=26130] Recording A8602096210405800406L200218680503121519 size is 4145956224 bytes
2019 May 22 03:32:17.952387 france1v4 sh[4937]: 190522-03:32:17.951895 [mod=REC, lvl=INFO] [tid=26130] RecordingInfo = fffocap://0x401e
2019 May 22 03:32:17.952466 france1v4 sh[4937]: 190522-03:32:17.951934 [mod=REC, lvl=INFO] [tid=26130] recording_dvr_from_recording_info:physicalSegmentCount=10
';
$subst = "$2";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php