#!/usr/bin/perl -w

use strict;

my $data = get_data_from_somewhere;

# First split the data up into a 2D structure
my @struct;
for (split /\n/, $data) { 
    push @struct, [ split /:/ ]
}

# Now we sort the struct on the second element of the nested arrays
@struct = sort { $a->[1] cmp $b->[1] } @struct;