Validate url parameters with preg_match - php

Question

Valid example
12[red,green],13[xs,xl,xxl,some other text with chars like _&-##%]
number[anythingBut ()[]{},anythingBut ()[]{}](,number[anythingBut ()[]{},anythingBut ()[]{}]) or nothing
Full match 12[red,green]
Group 1 12
Group 2 red,green
Full match 13[xs,xl,xxl,some other text with chars like _&-##%]
Group 1 13
Group 2 xs,xl,xxl,some other text with chars like _&-##%
Not valid example
13[xs,xl,xxl 9974-?ds12[dfgd,dfgd]]
What I tried is this: (\d+(?=\[))\[([^\(\[\{\}\]\)]+)\], regex101 link with what I tried, but this also matches wrong input like given in the example.

Answer 1

If you just need to validate the input, you can add some anchors:
^(?:\d+\[[^\(\[\{\}\]\)]+\](?:,|$))+$
Regex101
If you also need to get all the matching parts, you can use another regex. Using only one will not work well.

Answer 2

$in = '12[red,green],13[xs,xl,xxl,some other text with chars like _&-##%],13[xs,xl,xxl 9974-?ds12[dfgd,dfgd]]';
preg_match_all('/(\d+)\[([^][{}()]+)(?=\](?:,|$))/', $in, $matches);
print_r($matches);
Output:
Array
(
[0] => Array
(
[0] => 12[red,green
[1] => 13[xs,xl,xxl,some other text with chars like _&-##%
)
[1] => Array
(
[0] => 12
[1] => 13
)
[2] => Array
(
[0] => red,green
[1] => xs,xl,xxl,some other text with chars like _&-##%
)
)
Explanation:
/ : regex delimiter
(\d+) : group 1, 1 or more digits
\[ : open square bracket
( : start group 2
[^][{}()]+ : 1 or more any character that is not open or close parenthesis, brackets or square brackets
) : end group 2
(?= : positive lookahead, make sure we have after
\] : a close square bracket
(?:,|$) : non capture group, a comma or end of string
) : end group 2
/ : regex delimiter