#!/usr/bin/perl
use strict;
open (PIPE,"| yourFile.txt") or die "Can't open pipe: $!";
select PIPE;
$|=1;
select STDOUT;
my $count = 0;
for (1..10) {
print PIPE "line number $_\n" and $count++;
sleep 1;
}
close PIPE or die "Can't close pipe: $!";
print "Wrote $count lines of text\n";