Well ... It doesn't use strict, it doesn't use warnings, it doesn't have anything to populate $line, it tries to assign a regular expression (that looks like it tries to capture two bits of whitespace seperated by more whitespace) to $line when I suspect the goal is to apply it (hint =~). You then throw a couple of variables after the line (without doing anything sensible with them), possibly (judging from the names) in some attempt to capture data from the regular expression.

It also looks like another attempt at this question which seems to have some answers on how you should go about this.

I'd rather strongly suggest starting with perldoc perlintro though.

You should also use code tags. You should also ready the very first few {paraghraphs,chapters} of any introductory perl tutorial.

However here's an 'I'm-doing-it-for-you' solution:

#!/usr/bin/perl -l

my (@a1, @a2);
while (<>) {
    my ($a1, $a2) = split or next;
    next unless $a1 and $a2;
    push @a1, $a1;
    push @a2, $a2;
}
print for "@a1", "@a2";

__END__
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You may also be interested in -lan, see perlrun.

Can anyone tell me what is the error in this script

Actually, taking into account how short it is, it could easily score a very high rating for the density of errors it exhibits. Both in logic and in syntax. It doesn't even compile. Maybe it's valid code. Just not perl code. Period.

That's at least one issue with the code snippet you might like to look at..

You need to start all your homework assignments with these lines in your file:

#!/usr/bin/perl
use warnings;
use strict;
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#!/usr/bin/perl
use warnings;
use strict;

print "This is a test\n";
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If a piece of code compiles under warnings and strict but doesn't do what you want try adding print statments liberally in your code to check the values of your variables.