pcregrep Error -46 while using simple recursive regex

[michaeltyson]

Hi!

This regex:

(((?>[^()]+)|(?R))*)

Causes pcregrep/pcre2grep to bail immediately with error -46:

> pcre2grep '(((?>[^()]+)|(?R))*)' test.txt
pcre2grep: pcre2_match() gave error -46 while matching this text:
...

[zherczeg]

I cannot check it without a some kind of input. Anyway, #22 might fix this. Could you check it?

[michaeltyson]

It seems to occur on any input at all:

> echo hello world > test.txt
> pcre2grep '(((?>[^()]+)|(?R))*)'  test.txt
pcre2grep: pcre2_match() gave error -46 while matching this text:

hello world

pcre2grep: Error -46, -47, -53 or -63 means that a resource limit was exceeded.
pcre2grep: Check your regex for nested unlimited loops.

I'm afraid I don't have the time right now to get a build working (I just installed the homebrew version).

[zherczeg]

Hm, this pattern looks really like an unbound regex, since it recursively call itself without matching anything.

Regex101 also complains: https://regex101.com/r/qqLt6Z/1
The match was halted because your expression contains a recursive loop. This means either that the whole pattern, or a subpattern, has been called recursively for the second time at the same position in the subject string.

[michaeltyson]

Ah, okay, fair enough. I was just using it as I found it Out There On The Internet and it seemed to be being presented as an accepted technique for recursively matching bracket pairs. Guess I need to keep digging.