#! /usr/bin/perl -w

#Written by CSR on 11.7.08
#Input: list1 and list2 (two files).
#Output: union, intersection, unique to list1, and unique to list2.

use strict;
use List::Compare;
use Getopt::Std;

#command line arguments: import list1 and list2 using "-a" and "-b".
my $usage = "Warning, missing information!\nUsage is: ./two_list_comparison1.0.pl -a [list1 filename] -b [list2 filename]\n";
my %args;
getopts('a:b:', \%args);
my $file1;
my $file2;

if ($args{a}) {
    $file1 = $args{a};
} else {
    die "$usage";
}
if ($args{b}) {
    $file2 = $args{b};
} else {
    die "$usage";
}

#one array for each list
my @list1 = ();
my @list2 = ();

#generate an array of items from list1
open (LIST1 , $file1) or die "COULD NOT OPEN FILE";
while (my $line1 = <LIST1>) {
    chomp $line1;
    push @list1 , $line1;
}
close (LIST1);

#generate an array of items from list2
open (LIST2 , $file2) or die "COULD NOT OPEN FILE";
while (my $line2 = <LIST2>) {
    chomp $line2;
    push @list2 , $line2;

}
close (LIST2);

my $lc = List::Compare->new(\@list1, \@list2);

#get the union
my @union = $lc->get_union;

#create a filename and print the union list to a file.
my $unionfile = $file1."_and_".$file2.".union";
open (UNION_FH , "> $unionfile") or die "COULD NOT OPEN UNION FILE"; 
foreach my $union(@union) {
    print UNION_FH "$union\n";
}
close(UNION_FH);

#get the intersection
my @intersection = $lc->get_intersection;

#create a filename and print the intersection list to a file.
my $intersectionfile = $file1."_and_".$file2.".intersection";
open (INTERSECTION_FH , "> $intersectionfile") or die "COULD NOT INTERSECTION OPEN FILE";
foreach my $intersection(@intersection) {
    print INTERSECTION_FH "$intersection\n";
}
close (INTERSECTION_FH);

#get the items unique to list1
my @Lonly = $lc->get_Lonly;

#create a filename and print the unique2list1 to a file. 
my $Lonlyfile = $file1."_and_".$file2.".unique_to_$file1";
open (Lonly_FH , "> $Lonlyfile") or die "COULD NOT OPEN Lonly FILE";
foreach my $Lonly(@Lonly) {
    print Lonly_FH "$Lonly\n";
}
close (Lonly_FH);

#get the items unique to list2
my @Ronly = $lc->get_Ronly;

#create a filename and print the unique2list2 to a file.                                                                                                                                                                              
my $Ronlyfile = $file1."_and_".$file2.".unique_to_$file2";
open (Ronly_FH , "> $Ronlyfile") or die "COULD NOT OPEN Ronly FILE";
foreach my $Ronly(@Ronly) {
    print Ronly_FH "$Ronly\n";
}
close (Ronly_FH);