There are simple commandline pipes which you can set up, but here is a better example. If you need many scripts communicating, you probably want to use sockets.

The master script to run:

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


my $pid = open3(\*WRITE, \*READ,0, './myslave1');
            #if \*ERROR is false, STDERR is sent to STDOUT 

while (1){
#send something to slave
my $test = time;
my $str = $test x 50;
print WRITE "$str\n\n\n\n";

#get the answer from slave
my $buf;
sysread(READ,$buf,1024);

print "$test = $buf\n";

sleep 1;
}
waitpid($pid, 1);
# It is important to waitpid on your child process,  
# otherwise zombies could be created.
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and the myslave1 script

#!/usr/bin/perl
use warnings;
use strict;
use IO::Select;

my $timeout = 1;

my $s = IO::Select->new();
$s->add( \*STDIN );

while (1) {
    if ( my @ready = $s->can_read($timeout) ) {

        # we got input
        for my $fh (@ready) {
               my $input;
               sysread( $fh, $input, 1024);
                                          
           #do some processing, for example
           syswrite(STDOUT, "processed: $input");
        }
    }
}
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