Question about parentheses in regex

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

Oh wise seekers of the Perl Wisdom, I come seeking help. This is, I am sure, a novice question and most likely a stupid one... But I've tried everything I can think of and can't seem to get this to work. I ran into an issue where words in parentheses are not being removed from a regex as wanted... The goal is to have anything inside of the curly braces (including the curly braces themselves) to disappear from the string. This works for all circumstances except for when there is a set of parentheses in the text.. I tried escaping the parentheses "$ and $", but it was to no avail.. I understand that the parentheses are grouping tools in regex, but I figured escaping them would fix that problem, and it did not...

my $text = "to { (This Word) }";
my $remove = "{ (This Word) }";

$text =~ s/\R//g;
$text =~ s/$remove//;
print $remove, $/, $/;
print $text;
[download]

Output:

{ (This Word) }

to { (This Word) }
[download]

Looking for someone to shed some light on the situation, as it's holding up my production. Again, I'm sorry for I'm sure this is a simple thing to fix..

Comment on Question about parentheses in regex Select or Download Code

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Re: Question about parentheses in regex by toolic (Bishop) on May 27, 2015 at 19:14 UTC
quotemeta `use warnings; use strict; my $text = "to { (This Word) }"; my $remove = quotemeta "{ (This Word) }"; $text =~ s/\R//g; $text =~ s/$remove//; print $remove, $/, $/; print $text; print "\n"; __END__ \{\ $This\ Word$\ \} to` [download]	[reply] [d/l]
Re^2: Question about parentheses in regex by Von_Halen (Novice) on May 27, 2015 at 19:17 UTC
Oh my god, I love you. Thank you very much. What does the quotemeta do in this case?	[reply]
Re^3: Question about parentheses in regex by choroba (Cardinal) on May 27, 2015 at 19:23 UTC
`my $remove = quotemeta "{ (This Word) }"; print $remove; # See what happened.` [download] You can also shorten it to `my $text = 'to { (This Word) }'; my $remove = '{ (This Word) }'; $text =~ s/\R//g; $text =~ s/\Q$remove//; # <-- the \Q means quotemeta` [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l] [select]
Re^3: Question about parentheses in regex by ww (Archbishop) on May 27, 2015 at 19:41 UTC
"What does the quotemeta do...?" That's thoroughly explained in the docs. Ask ~~your Teddy Bear~~ ... uh, no, I mean, ask your machine's command line interface (`using perldoc perlop` [look for "Quote and Quote-like Operators"] or ask your browser using a search engine for http://perldoc.perl.org/functions/quotemeta.html which will tell you all about it. We value ~~sell-help~~ self-help very highly here in the Monastery. You'll also find interesting (and helpful) information about site's expectations of those asking questions at PerlMonks FAQ section. Edited: Typo fixed. TY soonix for catching what I should have. Spirit of the Monastery check Ln42!	[reply]
Re^3: Question about parentheses in regex by Anonymous Monk on May 28, 2015 at 02:54 UTC
Von_Halen: What does the quotemeta do in this case? The quotemeta link says click me and read me	[reply]
Re: Question about parentheses in regex by Sathishkumar (Scribe) on May 28, 2015 at 06:39 UTC
Hi, check with below code. `my $text = "to { (This Word) }"; my $remove = "{ (This Word) }"; $text =~ s/\Q$remove\E//; print $remove, $/, $/; print $text;` [download] Regards, Sathishkumar S	[reply] [d/l]