Shell Programming and Scripting

awk 'NR==FNR {a[$3]; next} $3 in a' file1 file2 > exist_in_both.file

awk 'NR==FNR {a[$3]; next} !($3 in a)' file1 file2 > does_not_exist_in_both.file

#!/usr/bin/perl

use strict;
use warnings;

my $first_file = 1;
my %record;

my $hits = "match.txt";
my $misses = "unmatch.txt";

open my $fh1, '>', "$hits" or die "Could not open $hits: !$\n";
open my $fh2, '>', "$misses" or die "Could not open $misses: !$\n";

while(<>) {
    chomp;
    my @fields = split;
    if ( $first_file == 1 ) {
        $record{$fields[2]} = 1;
        next;
    }
    if (exists $record{$fields[2]}) {
        print $fh1 "$_\n";
    } else {
        print $fh2 "$_\n";
    }
}

continue {
    if (eof) {++$first_file};
}

close $fh1;
close $fh2;

awk '
FNR == NR {
	f1[++n1] = $3
	var[$3]
	next
}
{	if($3 in var) {	print $3 > "in_both"
			delete var[$3]
	} else		print $3 > "in_f2_only"
}
END {	for(i = 1; i <= n1; i++)
		if(f1[i] in var)
			print f1[i] > "in_f1_only"
}' file1 file2