Re: [bug-gawk] Strange matching behavior

[Aharon Robbins]

Hi.  Re this:

> However, if I add some other characters to the list ("." and "*" here), gawk
> fails:
>
> $ printf '%s\n' '[' ']' '.' '*' '$' | awk '/[][.*]/ { print "<" $0 ">" }'
> awk: cmd. line:1: error: Unmatched [ or [^: /[][.*]/

I traced this through in a debugger.

The "[." is seen as the opening characters in a POSIX collating sequence.
If you remove the "." or swap the order of the "." and the "*", it
works as expected.

So, it's not really a bug after all.  The error message is not as helpful
as it could/should be, but that's from the GLIBC regex code, and the
error of unmatched [ or [^ is returned in a lot of cases.

Thanks,

Arnold