Programming

#!/usr/bin/perl
$ot1=$ARGV[2];
$ot2=$ARGV[3];
open(mfileot1, ">$ot1");
open(mfileot2, ">$ot2");
use strict;
#----------------
# Hash Definition
#----------------
my %HashArray;
my @file1Line;
my @file2Line;
#--------------------
# Subroutine
#--------------------
sub comp_file{
   my ($FILE1, $FILE2) = @_;
   open (R, $FILE1) or die ("Can't open file $FILE1");
     foreach my $FP1(<R>){
        chomp($FP1);
        my ($k, $l) = split(/\s+/,$FP1);
        push @{$HashArray{'$FP1'}{$k}},$l;
     }
   close (R);
   open (P, $FILE2) or die ("Can't open file $FILE2");
     foreach my $FP2(<P>){
        chomp($FP2);
        my ($k, $l) = split(/\s+/,$FP2);
        push @{$HashArray{'$FP2'}{$k}},$l;
     }
   close (P);
   foreach my $key(keys %{$HashArray{'$FP1'}}){
     if (!exists $HashArray{'$FP2'}{$key}){
         foreach my $last(@{$HashArray{'$FP1'}{$key}}){
           push (@file1Line,"$key$last");
         }
     }
   }
   print mfileot1 "$_\n" for (sort @file1Line);
   close(mfileot1);
   foreach my $key(keys %{$HashArray{'$FP2'}}){
     if (!exists $HashArray{'$FP1'}{$key}){
         foreach my $last(@{$HashArray{'$FP2'}{$key}}){
           push (@file2Line,"$key$last");
         }
     }
   }
   print mfileot2 "$_\n" for (sort @file2Line);
   close(mfileot2);
}
############MAIN MENU####################################
# Pre-check Condition
# if the input doesn't contain two(2) files, return help
# USAGE: hash2files.pl FILE1 FILE2 FILE3 FILE4
#########################################################

if ($#ARGV != 3){
    print "USAGE: $0 <FILE1> <FILE2> <FILE3> <FILE4>\n";
    exit;
}
else {
    my ($FILE1, $FILE2, $OT1, $OT2)= @ARGV;
    &comp_file($FILE1, $FILE2);
}