The simplest mechanism is a shell pipe.

Producer: perl -e"$|++;for(1..10){ printf qq[%05d\n], $_; sleep 1 }"

Consumer: perl -E"$|++; while(<>){ print; }"

Communications:

>perl -e"$|++;for(1..10){ printf qq[%05d\n], $_; sleep 1 }" | perl -E"
+$|++; while(<>){ print; }"
00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
[download]

What have you tried thus far?

The perl IPC (inter-process communication) document describes various methods of interprocess communication in perl, including the use of signals, fifos, pipes, sockets, and semaphores. It also includes examples of bi-directional communications. After reviewing that document, all that should remain is just a small matter of programming. :)

Hope that helps.

I would use one of the many approaches outlined in perlipc.

#!/usr/bin/perl
# code by pg
use IO::Handle;
use strict;
use warnings;

$| ++;

pipe(PARENT_RDR, CHILD_WTR);


if (fork()) {
   if (fork()) {
       close CHILD_WTR;
       while (my $line = <PARENT_RDR>) {
           print "parent got $line";
       }
   } else {
       close PARENT_RDR;
       for (100..110) {
           print CHILD_WTR "$_\n";
       }
   }
} else {
   close PARENT_RDR;
   for (0..10) {
       print CHILD_WTR "$_\n";
   }
}
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