Split on every character inside square brackets

I have a problem with a regex, I have the following string

[date|Y-m-d]


which is a Token extracted from a text and I need to extract 'date' and 'Y-m-d', but I haven't been able to achieve my goal with the following regex, can someone help me

(?:[)([^|]+)(?:])


The tokens can be like:

[date|Y-m-d] should extract 'date' and 'Y-m-d'
[date|Y-m-d|today] should extract 'date', 'Y-m-d' and 'today'


Use: $tok = preg_split('/[|]/', $str, -1, PREG_SPLIT_NO_EMPTY) and then use $tok[0] and $tok[1]
– anubhava
Jun 29 at 9:21

$tok = preg_split('/[|]/', $str, -1, PREG_SPLIT_NO_EMPTY)

$tok[0]

$tok[1]

@claudio See this demo. It is for scenarios where only 1 match per string is expected.
– Wiktor Stribiżew
Jun 29 at 9:53

3 Answers
3

Use a regex pattern

(?<=^[||)[^|[]]*(?=||]$)


Test this regex solution here and a related PHP code here.

Thanks, that's what I was trying to achieve
– claudio
Jun 29 at 13:27

You can also achieve this by removing bracket with ltrim() & rtrim(). Then you can use explode with ":".

$str = explode(':', ltrim( rtrim($str, ']'), '['));
print_r( $str );


Output:

Array
(
[0] => date
[1] => Y-m-d
)


I assume you may have strings containing those substrings inside brackets and you want to extract them.

You may use

$str = '[date|Y-m-d] [date|Y-m-d|today]';
preg_match_all('/[([^]+)]/', $str, $matches);
$res = ;
foreach ($matches[1] as $m) {
array_push($res,explode("|", $m));
}
print_r($res);


See the PHP demo

Also, see the identical solution for scenarios where only 1 match per string is expected (PHP demo):

$str = 'A single match example [date|Y-m-d|today] here.';
if (preg_match('/[([^]+)]/', $str, $matches)) {
print_r(explode("|", $matches[1]));
}


Details

'/[([^]+)]/'

[

]

|

If you just have a string equal to [...|...|...|etc.] you may either use Shivrudra's approach, or a very simple preg_match_all:

[...|...|...|etc.]

preg_match_all

$str = '[date|Y-m-d]';
preg_match_all('/[^][|]+/', $str, $matches);
print_r($matches[0]);


See another PHP demo.

The [^][|]+ pattern matches 1 or more chars other than [, ] and |. See the regex demo.

[^][|]+

[

]

|

Thanks, it helped. But my real problem is capturing an undetermined number of strings
– claudio
Jun 29 at 9:19

@claudio please update your question to clarify your actual problem then.
– Gordon
Jun 29 at 9:20

@claudio See this demo. It is for scenarios where only 1 match per string is expected.
– Wiktor Stribiżew
Jun 29 at 9:54

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