#!/usr/bin/perl
$oldFile1 = $ARGV[0];
$newFile1 = $ARGV[1];
$oldFile2 = "unchanged.txt";
$changes1 = "changed.txt";


if (!$oldFile1) {
printf("Error: No old file is provided\n");
exit(1);
}
if (!$newFile1) {
printf("Error: No new file is provided\n");
exit(1);
}

open(OLDFILE1, $oldFile1) or die("Can't open $oldFile1 for input: $!");
open(NEWFILE1, $newFile1) or die("Can't open $newFile1 for input: $!");
open(OLDFILE2, ">$oldFile2") or die("Can't open $oldFile2 for output: $!");
open(CHANGES1, ">$changes1") or die("Can't open $changes1 for output: $!");

foreach (<OLDFILE1>) {
$line1 = $_;
chomp $line1;
($x,$y,$z,$a,$b,$c)=split(/\|/,$line1);
foreach  (<NEWFILE1>) {
$line2 = $_;
chomp $line2;
($x1,$y1,$z1,$a1,$b1,$c1)=split(/\|/,$line2);


if ($x eq $x1) {
    print OLDFILE2 "$line1\n";
		}
	else {
		print CHANGES1 "$line2\n";
	}
 }
}
close(OLDFILE1);
close(NEWFILE1);
close(OLDFILE2);
close(CHANGES1);