#!/usr/bin/perl -w
 
use strict;
 
my @data = qw|pa0002Yeadon.2(5091)
              pa0003Presidential.1(2664)
              pa0014Haverford.1(2589)|;
 
my @numbers = map { /\((\d+)\)/ } @data;
 
print "@numbers\n";
[download]

Dang, beat me to it =) I note, for the record, that killinrax's solution which is elegant, assumes you know that the first thing in your lines of data that are going to be wrapped in parentheses are the numbers you seek, AND that every line will contain a number (which may or may not be a problem; but if you want to do 1:1 matching of numbers onto lines, you'd like to know which line is missing a number if the sizes of @numbers and @data don't match up.)

In other words: it's a great basic technique, but be careful how you implement it!

Philosophy can be made out of anything. Or less -- Jerry A. Fodor

substr($string, -5, 4);
[download]

$idx = index($string, '(') + 1;
$num = substr($string, $idx, length($string) - $idx - 1);
[download]

($num) = $string =~ /\((\d+)\)/;

# Plus the year

($year, $num) = $string =~ /(\d+)[^(]*\((\d+)\)/;
[download]

($number)=$string=~/\(([^)]*)\)/;

If that assumption is false, reverse it:

$string = reverse $string; 
($number)=$string=~/\(([^)]*)\)/;
$number = reverse $number;
[download]

Even if there are other parens, reversing the string twice is a very weird way to get the data. Just use $ to anchor the match to the end of the string:

  ($number) = ($string =~ /\( (\d+) \)  # number in parentheses
                           [^()]* $/x);   # at the end of the string
[download]

Oops, you're right. I tend to overuse reversing ever since I found it to be such a nice solution to the comma-fying a number FAQ.

The key is the regular expression, which grabs the numbers out of the line (assuming your data is sane)

while (<FILE>) {
    # $number will only get set if the current line contains one or mo
+re digits in between parentheses

    my ($number) = /\((\d+))/;
    # do something with $number
}
[download]

I'd suggest reading perlre (but check your own system's docs) and poke around for phrases like "regular expression memory", which is the technique being employed here.

Philosophy can be made out of anything. Or less -- Jerry A. Fodor