Re: [checks/scripts] [PATCH 3/4] shell script wrapper detection

["Adam D. Barratt" <adam@adam-barratt.org.uk>]

On Sat, 2008-06-14 at 05:08 +0200, Frank Lichtenheld wrote:
> On Fri, Jun 13, 2008 at 03:09:00PM +0100, Adam D. Barratt wrote:
> > +	last if (++$i > 55);
> > +	if (/(^\s*|\beval\s*[\'\"]|(;|&&)\s*)exec\s*.+\s*.?\$$var.?\s*(--\s*)?.?(\${1:?\+.?)?(\$(\@|\*))?/) {
> 
> I guess that regex could really use a little /x treatment.

It's certainly not the nicest expression; it's grown somewhat over time.

My first attempt at splitting it up results in:

       if (m~
            # the exec should either be "eval"ed or a new statement
            (^\s*|\beval\s*[\'\"]|(;|&&)\s*)

            # eat anything between the exec and $0
            exec\s*.+\s*

            # optionally quoted executable name (via $0)
            .?\$$var.?\s*

            # optional "end of options" indicator
            (--\s*)?

            # Match expressions of the form '${1+$@}', '${1:+"$@"',
            # '"${1+$@', "$@", etc where the quotes (before the dollar       
            # sign(s)) are optional and the second (or only if the $1
            # clause is omitted) parameter may be $@ or $*.
            #
            # Finally the whole subexpression may be omitted for scripts
            # which do not pass on their parameters (i.e. after re-execing
            # they take their parameters (and potentially data) from stdin
            .?(\${1:?\+.?)?(\$(\@|\*))?~x) {

which is (at least imho) a significant improvement on the original.
Suggestions for better wording welcome. :)

Adam