This isn't a code writing service and you seem to be ignoring advice you've been given about acquainting yourself with the basics of perl. Once again open.

Update: See also How do I write to a file? or better still, as previously advised spend time learning the basics in the tutorials section or http://learn.perl.org.

marto-

I apologize for being lazy with my posting and not thoroughly reviewing my code before putting it on here. I realize also that I was not very clear with my question. I know how to use the open function, but don't know how I would use it here. If my code looks like this:

foreach (@input2) {
        open (STDOUT, ">$outputfile");
        print $_ if m#$criterion#;
}
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Then the output file will only contain the matched result of the final iteration of the foreach loop. My question, then, is where in the code I could place the open function so that the result of every iteration is printed in the output file.

Sorry to keep bothering you with this, and I will not ask any more questions regarding this code

Thanks, shravnk

"I know how to use the open function, but don't know how I would use it here."

Clearly you don't because you still maing the same mistakes. You aren't checking for errors opening files, I've mentioned this three times already:

Re: XML::Twig Help Re^3: XML::Twig Help Re^5: Parsing Large XML

The open documentation explains the difference between opening for writing and appending. You also shouldn't be opening the file for each print. See also How come when I open a file read-write it wipes it out? from perlfaq5. A short example:

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

my @input = qw( a b c d );

open(my $fh, '>', "output.txt") or die "cannot open input file $!";

foreach(@input){
    print $fh "$_ \n";
}

close($fh);
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