Hi Rambo Welcome to Perlmonks;

To have the output of your process available inside your perl script you would need to open a pipe then read from that pipe. Like this:

use warnings;
use strict;

my $file= "capture.txt";
my $command= "ls";

open ( FILE, ">$file") or die "Can't open $file, stopped";
open ( PIPE, "$command |") or die "Can't open pipe, stopped";
while (<PIPE>) {
    print ;
    print FILE;
}
[download]

Of course, this just opens $command as a child of your script. Giving you access to the output only. If you need to start a fully interactive process this is much harder. You might read perlipc.

ammended

See 'tee' with pipes for a command-line filter using this technique.