Hi,

This should give you a starting point:

#!/usr/bin/perl
use strict;
use warnings;
use 5.010;

use Carp;
use Data::Dumper;

use strict;
use Data::Dumper;

my %hash;

while(my $line = <DATA>) {
    chomp $line;
    next if $line =~ m/^\s*#/;
    next if $line =~ m/^\s*$/;
    my ($number, $user, $comment) = split /\s+/, $line, 3;

    $hash{$number} = {
        number => $number,
        user => $user,
        comment => $comment,
    }
}

say Dumper(\%hash), "\n";

__DATA__
#Number    User    Comments
1234567   sam    changed abc in the file.
5646542   john   deleted asds in the file.

45656     me     what a use name
535353    McA    Supermonk *grin*
[download]

UPDATE: MidLifeXis had a very good question at Re: Hash of Array references. If you want to allow more than one entry per number you can collect them in an array. So change the lines

    $hash{$number} = {
        number => $number,
        user => $user,
        comment => $comment,
    }
[download]

to

    push @{$hash{$number}}, {
        number => $number,
        user => $user,
        comment => $comment,
    };
[download]

Regards
McA