You mean like this? 


#!/usr/bin/perl -w
use strict;
my %seen = ();
while (<DATA>) {
    my ($one, $two) = split;
    $seen{$one} = [$two, exists $seen{$one} ? @{$seen{$one}} : () ];
}
for my $key (keys %seen) {
    print $key, " ", join(", ", @{$seen{$key}}), "\n";
}
__DATA__
a 1
a 2
a 3
a 4
b 1
c 1
d 1

[download]

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com

In reply to Re: A Not so Simple Append by clemburg
in thread A Not so Simple Append by Limo

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