preg_match(); - Unknown modifier '+'

Question

Alright, so I'm currently working on parsing an RSS feed. I've gotten the data I need no problem, and all I have left is parsing the game title.

Here is the code I currently have (ignore the sloppiness, it is just a proof of concept):

<?php
$url = 'http://raptr.com/conexion/rss';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
$result = curl_exec($ch); 
curl_close($ch);

$xml = new SimpleXMLElement($result);

$lastgame = $xml->channel->item[0]->description;
preg_match('[a-zA-Z]+</a>.$', $lastgame, $match);

echo $match;
?>

Everything was working great, but then I started getting this error:

Warning: preg_match() [function.preg-match]: 
Unknown modifier '+' in raptr.php on line 14

The only thing I have left is to strip out the closing anchor tag and the period, but I can't seem to figure out why it isn't liking the '+'. Any ideas?

Edit: This should not be marked as a duplicate as it was asked two years before the other question.

Inspecting the rss feed, you don't want to use the `$` there. — mario, Apr 08 '11 at 02:48
When I remove the $ it only matches "Conexion", I appreciate the help though! — David Bradbury, Apr 08 '11 at 02:54
What did you intend to match? All links by any chance? Then try `preg_match_all`. Otherwise try an RSS parser. — mario, Apr 08 '11 at 02:57
I just want the most recent game played. It is always the text within the second link. I wish they organized the feed better. — David Bradbury, Apr 08 '11 at 02:59
@mario - It sort of works, but for some reason it is returning an array inside of an array - `Array ( [0] => Array ( [0] => Conexion [1] => Minecraft ) ) ` — David Bradbury, Apr 08 '11 at 03:06
Yes, that's the difference to the normal preg_match which would just return one result. — mario, Apr 08 '11 at 03:08

score 70 · Accepted Answer · answered Apr 08 '11 at 02:38

70

You need to use delimiters with regexes in PHP. You can use the often used /, but PHP lets you use any matching characters, so @ and # are popular.

Further Reading.

If you are interpolating variables inside your regex, be sure to pass the delimiter you chose as the second argument to preg_quote().

answered Apr 08 '11 at 02:38

alex

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Well, that was a surprise. `string preg_quote ( string $str [, string $delimiter = NULL ] )` -> function signature forces nothing as default, thus kicked me in the balls when least expected. Default should be `/`. – stamster Aug 08 '18 at 15:14

Khez · Answer 2 · 2011-04-08T03:06:43.223

29

Try this code:

preg_match('/[a-zA-Z]+<\/a>.$/', $lastgame, $match);
print_r($match);

Using / as a delimiter means you also need to escape it here, like so: <\/a>.

UPDATE

preg_match('/<a.*<a.*>(.*)</', $lastgame, $match);
echo'['.$match[1].']';

Might not be the best way...

edited Apr 08 '11 at 03:06

answered Apr 08 '11 at 02:38

Khez

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print_r($match); returns "Array ( )"I'm pretty sure my expression is correct. – David Bradbury Apr 08 '11 at 02:44
I don't know what you tried to say with your comment... – Khez Apr 08 '11 at 02:47
@Conexion, checked your other comments, what is it you are trying to pull from that rss feed into your match ? The games ? – Khez Apr 08 '11 at 02:55
Yup, just trying to pull the most recent game :) – David Bradbury Apr 08 '11 at 02:56
It works, but the problem is, the feed doesn't always being with "played some". Sorry I'm being difficult! – David Bradbury Apr 08 '11 at 03:04
Updated my code yet again, considered this time you always have USER Game in that order. – Khez Apr 08 '11 at 03:07

score 6 · Answer 3 · edited Jul 26 '16 at 06:52

6

This happened to me because I put a variable in the regex and sometimes its string value included a slash. Solution: preg_quote.

edited Jul 26 '16 at 06:52

XtraSimplicity

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answered Nov 20 '14 at 00:03

David Winiecki

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Thank you for letting me know about preg_quote - very useful function! – Shane N Jul 09 '15 at 21:40

score 1 · Answer 4 · edited Nov 10 '17 at 19:55

1

May be this will be usefull for u: ReGExp on-line editor

edited Nov 10 '17 at 19:55

Funk Forty Niner

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answered Apr 08 '11 at 02:46

Light

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preg_match(); - Unknown modifier '+'

4 Answers4

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