Though I am sure that the better approach is to change the first script, here is a (very) simple solution to feed the two filenames to the script.

I assume your first script looks something like this:

use strict;

my ($filename_in, $filename_out);

while ($filename_in eq "") {
  print "IN file: ";
  $filename_in = <>;
  chomp $filename_in;
}

while ($filename_out eq "") {
  print "OUT file: ";
  $filename_out = <>;
  chomp $filename_out;
}

print "IN:  [$filename_in]\n";
print "OUT: [$filename_out]\n";
[download]

Then you could use this script to execute the first script and feed the two filenames to it:

use strict;

my $command = "./script1.pl";
my ($filename_in, $filename_out) = qw(infile outfile);
system ("echo \"$filename_in\n$filename_out\n\" | $command");
[download]

Assuming, of course, you are on a Un*x machine, echo is in your path,the first script is called "script1.pl", etc.

------ kurt