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

chomp (my @data_lines = <DATA>);

# Sort the data lines according to the "Company Name" field and then the "Invoice ID" field.
@data_lines = sort {
    my ($company_name_a, $invoice_ID_a) = (split /~/, $a)[0, 1];
    my ($company_name_b, $invoice_ID_b) = (split /~/, $b)[0, 1];
    ($company_name_a) cmp ($company_name_b)
        or $invoice_ID_a <=> $invoice_ID_b
} @data_lines;

print "$_\n" for @data_lines;

__DATA__
SEALEVEL SYSTEMS~1
SEALEVEL SYSTEMS, INC.~2
SEBASTIAN COMMUNICATIONS~3
MASQUE SOUND~4
MASSTECH, INC~5
MASTERBILT~6
SE INTERNATIONAL~7

##</code><code>##

MASQUE SOUND~4
MASSTECH, INC~5
MASTERBILT~6
SE INTERNATIONAL~7
SEALEVEL SYSTEMS~1
SEALEVEL SYSTEMS, INC.~2
SEBASTIAN COMMUNICATIONS~3