CODEWITHSUNDEEP
phpregexpreg-match-all
Skylude
Skylude

Reputation: 504

PHP preg_match_all not finding first match

I am trying to find all matches in a string. For some reason if my match is at the start of the string it is not returning that particular match. Does it have something to do with index 0? I am also using PREG_OFFSET_CAPTURE to get the indexes vs. the matches. Below is the code of working an non-working.

$text = '[QUOTE]I wonder why[QUOTE]PHP[IMG]hates me[/IMG][/QUOTE][/QUOTE][URL="http://www.bing.com"]Click me![QUOTE]........[/QUOTE]Ok Bai![/URL]';
preg_match_all('#\[QUOTE\]#', $text, $matches, PREG_OFFSET_CAPTURE, PREG_PATTERN_ORDER);
print_r($matches);

The result of which is:

Array ( [0] => Array ( [0] => Array ( [0] => [QUOTE] [1] => 19 ) [1] => Array ( [0] => [QUOTE] [1] => 100 ) ) )

As you can see it only found two matches. If I add a character to the start of the string it will then find all three.

$text = 'a[QUOTE]I wonder why[QUOTE]PHP[IMG]hates me[/IMG][/QUOTE][/QUOTE][URL="http://www.bing.com"]Click me![QUOTE]........[/QUOTE]Ok Bai![/URL]';
preg_match_all('#\[QUOTE\]#', $text, $matches, PREG_OFFSET_CAPTURE, PREG_PATTERN_ORDER);
print_r($matches);

The result of which is:

Array ( [0] => Array ( [0] => Array ( [0] => [QUOTE] [1] => 1 ) [1] => Array ( [0] => [QUOTE] [1] => 20 ) [2] => Array ( [0] => [QUOTE] [1] => 101 ) ) )

All three matches. If anyone can help me figure out if my REGEX needs to be modified or if there is some quirk I'm unaware of it would be much appreciated. I've tried this same thing utilizing Python and the re library and it returns all my matches. I also utilized this http://www.regextester.com/ and it reports it as working in both scenarios and matching everything as it should. My only guess is something to do with the PREG_OFFSET_CAPTURE finding a match at position 0 and the 0 causing some issue.

Thanks in advance for any assistance!

Upvotes: 0

Views: 548

Answers (2)

jeroen
jeroen

Reputation: 91734

The problem is in your function call:

preg_match_all('#\[QUOTE\]#', $text, $matches, PREG_OFFSET_CAPTURE, PREG_PATTERN_ORDER);

The fifth parameter is the offset, not another flag.

Upvotes: 0

Wrikken
Wrikken

Reputation: 70460

The correct way to add multiple flags is with a pipe |, so:

preg_match_all('#\[QUOTE\]#', $text, $matches, PREG_OFFSET_CAPTURE | PREG_PATTERN_ORDER);

Your , before PREG_PATTERN_ORDER means it becomes the 'offset' parameter (at which point in the string to start), and as PREG_PATTERN_ORDER==1, it starts at the second character.

Upvotes: 3

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