From: Chris Devers <[EMAIL PROTECTED]>
> On Mon, 2 Aug 2004, Bob Showalter wrote:
> > sudhindra k s wrote:
> >> Hi
> >>
> >> Can someone please tell me what the following code is trying to do
> >>
> >>
> >> if ( /CR List/ .. /\(2\)/ ) {
> >> if ( /CR List/ ) { print " $'\n"; }
> >> elsif ( /\(2\)/ ) {print " $` \n" ;}
> >> else { print " $_\n";}
> >> }
> >>
> >> I know that it is trying to print whatever is there between CR List
> >> and (2). But i am not able guess more than that.
> >
> The whys and hows of this are complicated -- it's worth reading _MRE_.
> The short version is that you should almost always replace code that
> uses $`, $&, or $' with functionally equivalent code that gets the
> same result without using these variables. For example, this code
> could be:
>
> if ( /CR List(.*)/ .. /(.*)\(2\)/ ) {
> if ( /CR List/ ) { print " $1\n"; }
> elsif ( /\(2\)/ ) { print " $1 \n" ;}
> else { print " $_\n";}
> }
>
> ...or something to that effect.
There should be
if ( /CR List(.*)/ .. /(.*?)\(2\)/ ) {
Otherwise you might get different results.
The original finds the first (2) in the line, your version the last
one.
> Of course, it could be that more recent versions of Perl have fixed
> this problem and I'm not aware of it. If so, please correct me :-)
I believe the penalty is still there.
Of course in a one-off script that contains no other regexps it may
not matter, but I'd still recommend forgetting these variables even
exist.
Jenda
===== [EMAIL PROTECTED] === http://Jenda.Krynicky.cz =====
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