Question

I found this regex on a forum:

"/\+?\)\)(=.+?,.+?)?\](.+?)\[\/quote\](?!((.*?)\[\/quote\]))/s"

The regex should be able to extract data from a string. I will give you an example:

<?php
$string = ‘[quote=username]bla bla bla bla[/quote]’;

preg_match("/\+?\)\)(=.+?,.+?)?\](.+?)\[\/quote\](?!((.*?)\[\/quote\]))/s", $string, $match, null, 0);

print_r($match);

… However, nothing is returned to $match. I am guessing that there is something wrong with the regex, since it should return both ‘username’ and ‘bla bla bla bla’.
I am going to use the function for a quote function in a forum.

Thanks in advance,
fischer

Answer 1

I would use something a little easier to read…

$string = '[quote=username]bla bla bla bla[/quote]';

preg_match('/\[quote=(.*?)\](.*?)\[\/quote\]/', $string, $matches);

print_r($matches);

Output

Array
(
    [0] => [quote=username]bla bla bla bla[/quote]
    [1] => username
    [2] => bla bla bla bla
)

See it on IDEone.

I assume your string will contain more than that – hence lazy quantifiers and no beginning and end anchors.

Also, make sure your string is delimited by single (') or double quotes ("), not backticks. Backticks are syntactic sugar for a shell_exec() call.

Update

I’ll try and decipher your original regex for you…

/\+?\)\)(=.+?,.+?)?\](.+?)\[\/quote\](?!((.*?)\[\/quote\]))/s


/  -> start delimiter
\+? -> optional '+'
\) -> literal ')'
\) -> literal ')'
(=.+?,.+?)? -> not sure the reason for this (enlighten me?)
\] -> match literal ']'
(.+?) -> match one or more characters ungreedy
\[\/quote\] -> match ending '[/quote]'
(?! -> negative lookahead
((.*?) -> match 0 or more characters ungreedy
\[\/quote\] -> match ending '[/quote]'
))
/ -> ending delimiter
s -> case insensitive flag