I have a pattern like this
absint\(\s?(\$[A-Za-z0-9_]+)\s?\)\s?={2,3}\s?\g<1>|(\$[A-Za-z0-9_]+)\s?==\s?absint\(\s?\g<2>\s?\)
which findes code like $id == absint($id) or $id == absint($id). It works fine with preg_match function, in https://regex101.com but PHPStorm doesn't support this syntax. How can I do exactly the same thing in PHPStorm search ?
It appears you cannot use recursion in PHP Storm. You may repeat the pattern though:
absint\(\s?\$\w+\s?\)\s?={2,3}\s?\$\w+|\$\w+\s?={2,3}\s?absint\(\s?\$\w+\s?\)
^^^^^ ^^^^^ ^^^^^ ^^^^^
See the regex demo (JS flavor chosen that does not support pattern recursion).
The \w matches letters, digits or underscores, and in case of a non-Unicode-aware regex, is equal to [A-Za-z0-9_].
Now, if you mean to only match the same variables on both ends, you may use backreferences (instead of the recursion constructs):
absint\(\s?(\$\w+)\s?\)\s?={2,3}\s?\1|(\$\w+)\s?={2,3}\s?absint\(\s?\2\s?\)
xxxxxxx xx yyyyyyy yy
Backreferences do not repeat (reuse) the group patterns (as is the case with \g<1> or (?1)), but they are placeholders for the text captured with the corresponding groups.
See Using Backreferences To Match The Same Text Again vs. Regular Expression Subroutines.