#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say fc };

*ARGV = *DATA{IO};

my $column_line = "";
$column_line = <> while $column_line !~ /Invoice ID/i;
chomp( my @columns = split /\t/, $column_line );

chomp( my @data_lines = <> );

# Sort the data lines according to the "Company Name" field, and then 
+the "Invoice ID" field.
my ($company_name_index) = grep { $columns[$_] eq "Company Name" } 0 .
+. $#columns;
my ($invoice_ID_index) = grep { $columns[$_] eq "Invoice ID" } 0 .. $#
+columns;
@data_lines = sort {
    my ($company_name_a, $invoice_ID_a) = (split /\t/, $a)[$company_na
+me_index, $invoice_ID_index];
    my ($company_name_b, $invoice_ID_b) = (split /\t/, $b)[$company_na
+me_index, $invoice_ID_index];
    fc($company_name_a) cmp fc($company_name_b) or
    $invoice_ID_a <=> $invoice_ID_b
} @data_lines;

print "Replacement Header Text Here\n\n$column_line";
say for @data_lines;

__DATA__
Original Header Text    
    
Invoice ID    Company Name
1    SEBASTIAN COMMUNICATIONS
2    MASQUE SOUND
3    SEALEVEL SYSTEMS
4    MASSTECH, INC
5    SE INTERNATIONAL
6    SOUTHEAST SERVO, LLC
7    SEALEVEL SYSTEMS, INC.
8    MASTERBILT
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