Re: Regex: Extracting the case insensitive string and printing on the output

I recommend to use ${^MATCH}. It is much faster than capturing to $1

Benchmark: timing 2222234 iterations of code_1, code_2...
    code_1:  4 wallclock secs ( 4.03 usr +  0.00 sys =  4.03 CPU) @ 55
+1422.83/s (n=2222234)
    code_2:  2 wallclock secs ( 2.27 usr + -0.01 sys =  2.26 CPU) @ 98
+3289.38/s (n=2222234)
           Rate code_1 code_2
code_1 551423/s     --   -44%
code_2 983289/s    78%     --
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... and don't forget about quotemeta or \Q \E when matching $strings.

$mytarget = "I am a perl program";
$mystring = "Perl";
if ($mytarget =~ m/\Q$mystring\E/i)
     {       
         print "It matches: ${^MATCH}\n";   
     }   
  else {       
         print "It doesn't match\n";    
    }
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Re^2: Regex: Extracting the case insensitive string and printing on the output by AnomalousMonk (Archbishop) on Nov 29, 2011 at 08:16 UTC
I recommend to use ${^MATCH}. Always use the /p regex modifier when using `${^MATCH}` and friends. The use of `${^MATCH}` may appear to work without the /p modifier, but this is only fortuitous. Quoth perlvar (emphasis added): ${^MATCH} This is similar to $& ($MATCH) except that it does not incur the performance penalty associated with that variable, and is only guaranteed to return a defined value when the pattern was compiled or executed with the "/p" modifier.	[reply] [d/l] [select]

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Re^2: Regex: Extracting the case insensitive string and printing on the output
by AnomalousMonk (Archbishop) on Nov 29, 2011 at 08:16 UTC

I recommend to use ${^MATCH}.

Always use the /p regex modifier when using ${^MATCH} and friends. The use of ${^MATCH} may appear to work without the /p modifier, but this is only fortuitous.

Quoth perlvar (emphasis added):

${^MATCH}
This is similar to $& ($MATCH) except that it does not incur the performance penalty associated with that variable, and is only guaranteed to return a defined value when the pattern was compiled or executed with the "/p" modifier.

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