Re: [bug-gawk] Regex problem with gawk 4.1.2

[Andrew J. Schorr]

Hi Henrik,

On Wed, May 13, 2015 at 08:38:31PM +0200, Henrik Levkowetz wrote:
> One of my venerable awk programs, which I've tried to keep compatible with 
> awk,
> nawk, and gawk for close to 15 years, suddenly broke when run with gawk 4.1.2.
> 
> I've reduced the problem to the following little snippet.  The problem seems
> to be with inclusion of an unquoted '[' character within the regex bracket
> expression, but not as the first character.  According to the manual this 
> should
> work [1], and it has indeed worked for me as long as I've worked with awk, but
> doesn't do so any more in 4.1.2:
> 
> #!/opt/local/bin/gawk -f
> BEGIN {
>   ref = ",";
>   if (ref ~ /[,[]/) { print "whoo"; }
> }
> 
> My copy of gawk 4.1.2 is running on OS X, version 10.9.5, installed with 
> macports,
> and gives its version number as "GNU Awk 4.1.2, API: 1.1"

There is a regexp bracket parsing bug in gawk 4.1.2.  It will be fixed in gawk
4.1.3.  You can fetch a working version from the git repository gawk-4.1-stable
branch.

https://www.gnu.org/software/gawk/manual/html_node/Accessing-The-Source.html

Something like (off the top of my head):
   git clone git://git.savannah.gnu.org/gawk.git gawk
   cd gawk
   git checkout gawk-4.1-stable
   ./bootstrap.sh && ./configure && make && make check && make install

Sorry for the trouble.

Regards,
Andy