in reply to compare two files line by line and perform a diff on each coressponding line

If you only want to compare each line of tst1 to the corresponding line in tst2 you don't need two loops. Use something like this:

while (@tst1)
{
  $i= shift @tst1;
  $j= shift @tst2;
  chomp($i);
  chomp($j);
 `diff $i $j > /dev/null`;
 `echo $?`;
}

[download]

You thought you needed two loops because you wanted to step through two arrays, but you need only one loop that makes a simultaneous step through both arrays.

  • Comment on Re: compare two files line by line and perform a diff on each coressponding line
  • Download Code

Replies are listed 'Best First'.
Re^2: compare two files line by line and perform a diff on each coressponding line
by dilip_val (Acolyte) on Jun 01, 2010 at 15:33 UTC
    Thanks jethro and all , this seemed to work 
    #! /usr/bin/perl
use File::Compare;
open (IF,"<tst1");
open (IF2,"<tst2");
my(@tst1) = <IF>;
my(@tst2) = <IF2>;
my ($i);
my ($j);
while (@tst1)
{
 $i=shift @tst1;
 $j= shift @tst2;
 chomp($i);
 chomp($j);
 #print "$i\n";
 #print "$j\n";
 if (compare("$i","$j") == 0) {
 print "$i $j are equal\n";
 }
 else
 {
 print "$i $j are not equal\n";
 }
}
close(IF);
close(IF2);

    [download]
[reply]
[d/l]

In Section Seekers of Perl Wisdom