#!/usr/bin/perl
use strict;
use warnings;
$ENV{ODMDIR} = '/etc/objrepos/'; # needed for external program
my $user = 'testuser';
my $password = 'testpass';
my $cmd = "/usr/es/sbin/cluster/sbin/cl_chpasswd -cspoc -f -k $user";
#print $cmd, $/x2; # verified - OK

use IPC::Open2;
my $pid = open2(*Reader, *Writer, $cmd);

# No success with following variations:
#my $pid = open2(*Reader, *Writer, "$cmd </dev/tty");
#my $pid = open2(*Reader, *Writer, "$cmd </dev/tty >/dev/tty");
$| = 1;

# Verify device:
#use POSIX;
#my $tty = POSIX::ctermid();
#print "\nTTY: '$tty'\n\n"; # prints: TTY: '/dev/tty'

local *STDOUT;
open( STDOUT, ">>/dev/tty" );

# wait until external program is ready
sleep 5; 

# Enter password:
#print Writer "$password\n"; # neither displayed nor accepted as input
print "$password\n"; # will be displayed but not accepted as input
sleep 2;

# Repeat password:
#print Writer "$password\n";
print "$password\n";

waitpid $pid, 0;
close Reader;
close Writer;