#/usr/bin/perl
open(FILE1,"a.txt");
open(FILE2,"b.txt");
foreach $line (<FILE1>) {
chomp $line;
($a, $b, $c, $d, $e, $f, $g)=split(",",$line);
$array{$a}{$c}=$f;
}
foreach $line (<FILE2>) {
chomp $line;
($a, $b, $c, $d, $e, $f, $g)=split(",",$line);
if ($array{$a}{$c}!=$f) {
print "$line, [differs from: $array{$a}{$c}]\n";
}
}