Shell Programming and Scripting

a1.txt
a2.txt
a3.txt
a4.txt
a5.txt
a6.txt
a7.txt
a8.txt
a_index.txt

a1.txt
a3.txt
a7.txt

a2.txt
a4.txt
a5.txt
a6.txt
a8.txt
a_index.txt

grep -vxFf file2 file1

ls | grep -vxFf file.txt

#!/usr/bin/perl

use strict;

#----------------
# Hash Definition
#----------------
my %HoA;
my @name;

#--------------------
# 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 @{$HoA{'$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 @{$HoA{'$FP2'}{$k}},$l;
     }
   close (P);
    
   foreach my $key(keys %{$HoA{'$FP1'}}){
     if (!exists $HoA{'$FP2'}{$key}){
         foreach my $last(@{$HoA{'$FP1'}{$key}}){
           push (@name,"$key$last");       
         }    
     }    

   }
  
   print "$_\n" for (sort @name);
}

############MAIN MENU####################################
# Pre-check Condition
# if the input doesn't contain two(2) files, return help 
# USAGE: check.pl FILE1 FILE2
#########################################################


if ($#ARGV != 1){ 
    print "USAGE: $0 <FILE1> <FILE2> \n"; 
    exit;
} 
else {
    my ($FILE1, $FILE2)= @ARGV;
    &comp_file($FILE1, $FILE2);
}

##RESULT DATA#####
#a2.txt
#a4.txt
#a5.txt
#a6.txt
#a8.txt
#a_index.txt