#!/usr/bin/perl
use warnings;
use strict;
use IPC::Open3;

my $pid = open3(\*WRITE, \*READ, 0,"success.pl");
            #if \*ERROR is false, STDERR is sent to STDOUT 

#get the answer 
chomp(my $answer = <READ>);
print "query = $answer\n";

waitpid($pid, 1);
# It is important to waitpid on your child process,  
# otherwise zombies could be created.
[download]

....or run a command interpreter like bash, and print commands to it

#!/usr/bin/perl 
use warnings;
use strict;
use IPC::Open3;

$|=1;

#my $pid=open3(\*IN,\*OUT,\*ERR,'/bin/bash');
my $pid=open3(\*IN,\*OUT,0,'/bin/bash');
# set \*ERR to 0 to send STDERR to STDOUT

my $cmd = 'date';

#send cmd to bash
print IN "$cmd\n";

my $result = <OUT>;
print $result;
[download]