[perlre] grouping parenthesis capture whole string instead of proper subset... why?

princepawn has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: [perlre] grouping parenthesis capture whole string instead of proper subset... why? by lestrrat (Deacon) on Oct 25, 2002 at 21:28 UTC
`if($setstr =~ /(.*)\\|\\|$/) { ... }` [download] works for me ;)	[reply] [d/l]
Re: [perlre] grouping parenthesis capture whole string instead of proper subset... why? by Tanalis (Curate) on Oct 25, 2002 at 21:29 UTC
\| is used by Perl to mean OR - you probably need to escape it, like this: `$setstr =~ /(.*)\\|\\|$/` If you always want to remove two pipes from the end of a line, you could also use the substitute function: `$setstr =~ s/\\|\\|$//;` Hope this helps --Foxcub	[reply] [d/l] [select]
Re: [perlre] grouping parenthesis capture whole string instead of proper subset... why? by VSarkiss (Monsignor) on Oct 25, 2002 at 21:32 UTC
lestrat's answer is correct, but you can also do: `$setstr =~ s/\\|\\|$//;`if your sole intent is to remove two vertical bar characters at the end.	[reply] [d/l]
Re: [perlre] grouping parenthesis capture whole string instead of proper subset... why? by robartes (Priest) on Oct 25, 2002 at 21:31 UTC
Pipes are special in regexpen, therefore you need to escape them, for example using the \Q trick: `use strict; my $string="altcategory=\|\|"; $string =~ /(.)\Q\|\|\E$/; print $1;` [download] or by introducing leaning toothpick (or cross-eyed plumbing in the case of pipes) syndrome: `$string=~/(.)\\|\\|$/;` [download] CU Robartes-	[reply] [d/l] [select]
Re: [perlre] grouping parenthesis capture whole string instead of proper subset... why? by DaveH (Monk) on Oct 27, 2002 at 18:39 UTC
You could make use of chomp and Perl's "Input Record Separator": `my $setstr = 'altcategory=\|\|'; warn $setstr; { $/='\|\|'; chomp $setstr } warn $setstr;` [download] Cheers, -- Dave :-)	[reply] [d/l]