1--TEST-- 2preg_match() flags 3 3--FILE-- 4<?php 5 6var_dump(preg_match('', '', $match, 0xfff)); 7 8var_dump(preg_match('/\d+/', '123 456 789 012', $match, 0, -8)); 9var_dump($match); 10 11var_dump(preg_match('/\d+/', '123 456 789 012', $match, 0, -500)); 12var_dump($match); 13 14var_dump(preg_match_all('/\d+/', '123 456 789 012', $match, 0, -8)); 15var_dump($match); 16 17var_dump(preg_match('/(?P<3>)/', '')); 18 19?> 20--EXPECTF-- 21 22Warning: preg_match(): Empty regular expression in %smatch_flags3.php on line 3 23bool(false) 24int(1) 25array(1) { 26 [0]=> 27 string(3) "789" 28} 29int(1) 30array(1) { 31 [0]=> 32 string(3) "123" 33} 34int(2) 35array(1) { 36 [0]=> 37 array(2) { 38 [0]=> 39 string(3) "789" 40 [1]=> 41 string(3) "012" 42 } 43} 44 45Warning: preg_match(): Compilation failed: group name must start with a non-digit at offset %d in %smatch_flags3.php on line %d 46bool(false) 47