use of built-in function in regex...

pkumar.pr has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

Is it possible to use built-in function like "reverse" inside regex.

for example: If there is a string "isasdffdsakk" I want to capture "asdffdsa" by using reverse function inside regex.

$string = 'isasdffdsakk';
if($string =~ /(.*?)(reverse\1)/s){
  print $1,$2;
}
[download]

Thank you.

Comment on use of built-in function in regex... Download Code

Replies are listed 'Best First'.
Re: use of built-in function in regex... by ikegami (Patriarch) on Aug 06, 2010 at 05:03 UTC
`/(.?)(??{ quotemeta reverse $1 })/s` [download] Of course, `(.?)` can match a zero-length string. And since it's not anchored, it will always match "". Remove the "?".	[reply] [d/l] [select]
Re: use of built-in function in regex... by murugu (Curate) on Aug 06, 2010 at 05:04 UTC
Yes. You can use `(?{CODE})` inside your regular expression. For more on this please look in to http://perldoc.perl.org/perlretut.html#A-bit-of-magic:-executing-Perl-code-in-a-regular-expression. Regards, Murugesan Kandasamy use perl for(;;);	[reply] [d/l]
Re: use of built-in function in regex... by suhailck (Friar) on Aug 06, 2010 at 06:02 UTC
`perl -le '$string = "isasdffdsakk"; if($string =~ /((.+?)(??{quotemeta reverse $2}))/s){ print $1; } ' asdffdsa` [download] ~suhail	[reply] [d/l]