in reply to Re^3: Regular Expression - pattern matching
in thread Regular Expression - pattern matching

Hi Darren,
I'm looking for the pattern like "xxxxx" if it's "xxxx_sssss" and also if it's "xx_ssss" then i need "xx_ssss" .
I have reuse your code 
 if (/^([^_]{2}_[^_]+)_/) {
        print $1;
    }

[download]
and it looks like 
for(@str) {
             my $temp;
             if (/^([^_]{2}_[^_]+)_/) {
               $temp=$1;
               print $temp."\n";  
         } else {
           ($temp)=$_=~/^([a-z0-9]+)\_/xi;
           print $temp."\n"; 
        }
  }

[download]

Unfortunately i didn't get the exact pattern which i showed in my output earlier.
Can you please correct me if i'm wrong ??
Thank you in advance.
-kulls

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Re^5: Regular Expression - pattern matching
by McDarren (Abbot) on Feb 22, 2006 at 17:55 UTC
    Okay, after scratching my head for about 20 minutes, I think I've worked out what you want.

    • If the first two characters are not underscores, but the third character is - then keep everything up to (but not including) the second underscore. Otherwise...
    • Keep everything up to (but not including) the first underscore.
    Is that correct?
    If yes, then the following should do it: 
    for (@strings) {
    my $temp = "";
    if (($temp) = $_ =~ m/^([^_]{2}_[^_]+)_?/) {
        print $temp;
    }
    elsif (($temp) = $_ =~ m/^([^_]+)/) {
        print $temp;
    }
}

    [download]
    Update: Oh, one thing I forgot to point out, was that there was an error in the code in my earlier reply. I hadn't accounted for the fact that there may not be any underscores at all. That's been fixed in the above snippet.
[reply]
[d/l]

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