Extract a portion of text

Gargouil

what type of command should i use to extract a part of text in a string

exemple:
bla bla bla bla [tag] i want this text extracted[/tag] bla bla bla

how could i extract the part between the 2 tag ?

swr

Something like this:

$string = 'bla bla bla bla [tag] i want this text extracted[/tag] bla bla bla';
preg_match('|\[tag\](.*?)\[/tag\]|i', $string, $matches);
echo $matches[1];

For more info check the [man]PCRE[/man] manual page. You may want to read a tutorial on "regular expressions" first though (even if it's not a PHP tutorial; most languages have regular expression functions).

Gargouil

i've tryed this:

preg_match("/[tag].*[\/tag]/", $string, $matches);

this work for a single line string
if i try that on a block of text with multiple ligne this don't work
i don'T know how to include the new line in the pattern

any idea ?

Weedpacket

The Manual
s
If this modifier is set, a dot metacharacter in the pattern matches all characters, including newlines. Without it, newlines are excluded.

Hence

preg_match("/\\[tag\\].*\\[\\/tag\\]/s", $string, $matches);

swr

Originally posted by Gargouil
i've tryed this:

preg_match("/[tag].*[\/tag]/", $string, $matches);

As Weedpacket said, use the s modifier.

Also... Using .* will give you problems if you have something like this:

[tag]foo[/tag] blah blah [tag]bar[/tag]

Using [tag].*[\/tag] will match this:

foo[/tag] blah blah [tag]bar

The reason being, the . is greedy and will match as much as it can. If you use .? instead, the ? makes it non-greedy. It will match as little as possible, meaning everything up to the first [/tag].