I read your problem differently than merlyn does. It seems to me that you want to match only if there is gonk at the end of the string, and you only care for up to the first five letters of the word between foobar: and gonk:

use strict;
use Test::More tests => 4;

sub ungonk {
  local $_ = $_[0];
  if (/^(foobar:.{1,5}).*gonk$/) {
    return $1
  } else {
    return undef
  };
};

is ungonk('foobar:hellogonk'), 'foobar:hello';
is ungonk('foobar:gonk'), undef;
is ungonk('foobar:higonk'), 'foobar:hi';
is ungonk('foobar:helloworldgonk'), 'foobar:hello';

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In reply to Re: RegEx - match !foo followed by foo by Corion
in thread RegEx - match !foo followed by foo by Melly

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