Perl Extracting matches

So /\d+/ and /(\d+) will still match as many digits as possible. but in the latter case they will be remembered in a special variable to be back referenced later.

Programming Perl


Extracting matches

The grouping metacharacters () also allow the extraction of the parts of a string that matched. For each grouping, the part that matched inside goes into the special variables $1 , $2 , etc. They can be used just as ordinary variables:

    # extract hours, minutes, seconds
    $time =~ /(\d\d):(\d\d):(\d\d)/; # match hh:mm:ss format
    $hours = $1;
    $minutes = $2;
    $seconds = $3;

http://perldoc.perl.org/perlrequick.html