C:\>type cat.pl
$|++;
print while <>;

C:\>type ipc.pl
use strict;
use IPC::Open2;
$|++;

my $EOF  = chr(0x1a);  # inline use "\x1a"
my $perl = "H:\\perl\\bin\\perl.exe";
my $cat  = "C:\\cat.pl";
my $data = "first line\nsecond line";

my $pid = open2(my $rdr, my $wtr, $perl, $cat );

print "Sending:\n$data\n----\n";
print $wtr $data .$EOF;

print "Going for read!\n";
print while <$rdr>;

C:\>perl ipc.pl
Sending:
first line
second line
----
Going for read!
first line
second line
C:\>