How to ignore special characters in a variable ?

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

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Re: How to ignore special characters in a variable ? by Fletch (Bishop) on Feb 15, 2011 at 18:23 UTC
Put your hands over your ears, stomp your feet, and say loudly "LA LA LA I'M IGNORING YOU SPECIAL CHARACTERS!" Or check out quotemeta and/or `\Q\E`. Whichever. The cake is a lie. The cake is a lie. The cake is a lie.	[reply] [d/l]
Re^2: How to ignore special characters in a variable ? by Anonymous Monk on Feb 15, 2011 at 18:42 UTC
Thank you very much	[reply]
Re: How to ignore special characters in a variable ? by toolic (Bishop) on Feb 15, 2011 at 18:23 UTC
quotemeta `use warnings; use strict; my $line = "CCCC--CCCC--CCC(--CC(O"; my $string = quotemeta "CCC("; if ($line =~ m/$string/) {print "match";}` [download]	[reply] [d/l]
Re^2: How to ignore special characters in a variable ? by Anonymous Monk on Feb 15, 2011 at 18:43 UTC
Thanks. It works !!	[reply]
Re: How to ignore special characters in a variable ? by wind (Priest) on Feb 15, 2011 at 18:51 UTC
quotemeta or \Q...\E `my $line = "CCCC--CCCC--CCC(--CC(O"; my $string = "CCC("; if ($line =~ m/\Q$string\E/) {print "match";}` [download]	[reply] [d/l]
Re^2: How to ignore special characters in a variable ? by Anonymous Monk on Feb 17, 2011 at 05:21 UTC
/Q.../E turns out to be better option than quotemeta. Just in case a beginner happens to read this node - remember - quotemeta modifies your string by adding "\" before special characters. If your string is a variable (like $string in above example), it becomes unusable. Having fun with perl... :-)	[reply]
Re^3: How to ignore special characters in a variable ? by ikegami (Patriarch) on Feb 17, 2011 at 06:54 UTC
\Q is quotemeta, so I don't see how it could be better. `>perl -MO=Concise,-exec -e"qq{\Q$x}" 1 <0> enter 2 <;> nextstate(main 1 -e:1) v:{ 3 <#> gvsv[x] s 4 <1> quotemeta[t2] sK/1 5 <@> stringify[t3] vK/1 6 <@> leave[1 ref] vKP/REFC -e syntax OK >perl -MO=Concise,-exec -e"quotemeta($x)" 1 <0> enter 2 <;> nextstate(main 1 -e:1) v:{ 3 <#> gvsv[x] s 4 <1> quotemeta[t2] vK/1 5 <@> leave[1 ref] vKP/REFC -e syntax OK` [download] If you're just talking about how it looks in the code, ok.	[reply] [d/l]
Re^3: How to ignore special characters in a variable ? by Anonymous Monk on Feb 17, 2011 at 05:24 UTC
/Q /E isn't real syntax, but \Q \E is :)	[reply]
Re^4: How to ignore special characters in a variable ? by Anonymous Monk on Feb 17, 2011 at 06:45 UTC
Re: How to ignore special characters in a variable ? by TomDLux (Vicar) on Feb 16, 2011 at 16:31 UTC
You want to know whether `$string` appears in `$line`, and possibly, where within the line it appears. This exactly matches the specification of the `index()` builtin routine. Try typing `perldoc -f index` into an xterm window, or check out CPAN's search facility. As Occam said: Entia non sunt multiplicanda praeter necessitatem.	[reply] [d/l] [select]
Re^2: How to ignore special characters in a variable ? by Anonymous Monk on Feb 17, 2011 at 05:34 UTC
Thanks. btw I loved the quote "Entia non sunt multiplicanda praeter necessitatem".	[reply]