Re: Removing only the first instance with RegEx

#!/usr/bin/perl

use strict;
use warnings;
           
my $bal;

$bal = qr /[^()]*
           (?: [(] (??{ $bal }) [)] )*
           [^()]*/x;
 
while (<DATA>) {
    chomp;
    print $& while /$bal/g;
    print "\n";
}


__DATA__   
(1.3.56.84 
56.38.m.26)
(56.2.3.59)
((one)(two))
((one(two))  
((one)(two)
(one)(two))
((one)two))
[download]

Running this gives:

1.3.56.84
56.38.m.26
(56.2.3.59)
((one)(two))
(one(two))
(one)(two)
(one)(two)
((one)two)
[download]

Abigail

Comment on Re: Removing only the first instance with RegEx Select or Download Code

Replies are listed 'Best First'.
Re: Re: Removing only the first instance with RegEx by Anonymous Monk on Nov 06, 2003 at 14:22 UTC
For the most part I understand what it's doing, but could you explain the '*' in the RegEx? Thanks	[reply]
Re: Removing only the first instance with RegEx by Abigail-II (Bishop) on Nov 06, 2003 at 14:29 UTC
For the most part I understand what it's doing, but could you explain the '' in the RegEx? Fascinating. You understand compiled regular expressions, delayed regular expressions, $&, but not '', one of the most used special tokens in a regular expression? Anyway, as 'man perlre' could have told you, '*' means that the thing in front of it can be matched zero or more times. Abigail	[reply]
Re: Re: Removing only the first instance with RegEx by Anonymous Monk on Nov 06, 2003 at 14:33 UTC
Wow...it's too early in the AM. I did know what'*' (zero or more) and '+' (one or more) mean. sorry!	[reply]