Bug #67235 [Fbk->Opn]: Possessive quantifier problem with preg_match()

Edit report at https://bugs.php.net/bug.php?id=67235&edit=1 ID: 67235 User updated by: david dot a dot schmitt at verizon dot com Reported by: david dot a dot schmitt at verizon dot com Summary: Possessive quantifier problem with preg_match() -Status: Feedback +Status: Open Type: Bug Package: PCRE related Operating System: Linux (Fedora 20) PHP Version: 5.5.12 Block user comment: N Private report: N New Comment: One example pattern that works differently is the POSSESSIVE pattern in the test script. i.e.: \A(?:[^"]++|"(?:[^"]*+|"")*+")++ (Obviously, you must surround that pattern with // for PHP, but not for pcregrep). Use the following text string to observe the difference: NON QUOTED "QUOT""ED" AFTER "NOT MATCHED echo "$TEXT" | pcregrep -o -e "$PATTERN" will display: NON QUOTED "QUOT""ED" AFTER but after preg_match($pattern, $text, $matches) $matches[0] only includes: NON QUOTED I originally observed the problem with a longer, more complex pattern, so this must be a more general problem than the single example pattern I am providing here. Previous Comments: ------------------------------------------------------------------------ [2014-05-11 12:52:54] felipe@php.net Well, could you clarify what is wrong here? Just give us the pattern which works differently from pcretest. ------------------------------------------------------------------------ [2014-05-09 13:39:57] david dot a dot schmitt at verizon dot com FYI, to clarify the script results you could change the TEXT setting in the script as follows: export TEXT='NON QUOTED "QUOT""ED""NOT MATCHED' Even with that change the expected and actual results remain the same. ------------------------------------------------------------------------ [2014-05-08 20:41:24] david dot a dot schmitt at verizon dot com Description: ------------ 1. preg_match() behaviour does not match pcregrep behaviour for some patterns involving possessive quantifiers. 2. preg_match() behaviour also appears internally inconsistent when switching from greedy to possessive quantifiers in those cases (+ to ++). Below is my environment (Fedora 20): $ php -V PHP 5.5.12 (cli) (built: May 3 2014 07:10:11) Copyright (c) 1997-2014 The PHP Group Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies $ pcregrep -V pcregrep version 8.33 2013-05-28 $ php -r "phpinfo();" | grep PCRE PCRE (Perl Compatible Regular Expressions) Support => enabled PCRE Library Version => 8.33 2013-05-28 Test script: --------------- #!/bin/sh export GREEDY='\A(?:[^"]++|"(?:[^"]*+|"")*+")+' export POSSESSIVE="$GREEDY+" export TEXT='NON QUOTED "QUOT""ED"' export PATTERN SCRIPT=' $t = getenv("TEXT"); $p = getenv("PATTERN"); preg_match("/$p/", $t, $m); print "$m[0]\n"; ' for PATTERN in "$GREEDY" "$POSSESSIVE" do echo "$TEXT" | pcregrep -o -e "$PATTERN" php -r "$SCRIPT" done Expected result: ---------------- NON QUOTED "QUOT""ED" NON QUOTED "QUOT""ED" NON QUOTED "QUOT""ED" NON QUOTED "QUOT""ED" Actual result: -------------- NON QUOTED "QUOT""ED" NON QUOTED "QUOT""ED" NON QUOTED "QUOT""ED" NON QUOTED ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=67235&edit=1