Shell Programming and Scripting

12345,john,london,9000
12345,Tom,london,9000

12345,Keath,london,9000
12345,Tom,london,9000

line1, column 2,File 1, john, File 2 ,Keath.

#!/usr/bin/perl

use strict;
use warnings;

my ($filename1, $filename2, @FILE1, @FILE2, $line, $linenumber, @file1, @file2);
$filename1 = "file1.txt";
$filename2 = "file2.txt";

open(file1,"<",$filename1) or die "Cannot open $filename1";
open(file2,"<",$filename2) or die "Cannot open $filename2";
@FILE1 = <file1>;
@FILE2 = <file2>;

if (scalar(@FILE1) !~ scalar(@FILE2)) {
print "One of the files have extra lines\n $filename1 has ", scalar(@FILE1), " lines\n $filename2 has ", scalar(@FILE2)," lines\n";
exit 1;
}
$line = 1;
$linenumber = 0;

foreach(@FILE2) {
@file1 = split(/,/,$FILE1[$linenumber]);
@file2 = split(/,/,$FILE2[$linenumber]);

if ( $file1[0] !~ $file2[0] ){print "Line $line, Column 1, $filename1, $file1[0], $file2[0], $filename2\n"}
if ( $file1[1] !~ $file2[1] ){print "Line $line, Column 2, $filename1, $file1[1], $file2[1], $filename2\n"}
if ( $file1[2] !~ $file2[2] ){print "Line $line, Column 3, $filename1, $file1[2], $file2[2], $filename2\n"}
if ( $file1[3] !~ $file2[3] ){print "Line $line, Column 4, $filename1, $file1[3], $file2[3], $filename2\n"}
$line = $line + 1;
$linenumber = $linenumber + 1;
}
close(file1);
close(file2);