Update: I misread the assignment. A single pipe-pair is all that's needed for the assignment, not two. The assignment asks for message(s) to come from the user, likely from STDIN. The demonstration is left intact and not changed in order to demonstrate bi-directional communication via pipes.

Greetings grjoe21, and welcome to the monastery.

A pipe is uni-directional whereas a socket is bi-directional. Therefore, the demonstration below requires two pipe pairs for bi-directional communication between the parent and child processes.

#!/usr/bin/env perl

use strict;
use warnings;

# Also, see Interactive Client with IO::Socket for another
# demonstration at: http://perldoc.perl.org/perlipc.html

pipe( my $p_rdr, my $c_wtr );
pipe( my $c_rdr, my $p_wtr );

autoflush $c_wtr, 1;
autoflush $p_wtr, 1;

my $pid = fork() // die "can't fork: $!";

if ( $pid ) {
   # parent process
   my $reply;
   while ( defined ( $reply = <$p_rdr> ) ) {
      last if ( length $reply == 1 );
      print $p_wtr "Hello, $reply";
   }
   waitpid $pid, 0;
}
else {
   # child process
   my $reply;
   my @names = qw/ Sun Moon Wind Air /;
   for my $name ( @names ) {
      print $c_wtr "$name\n";
      $reply = <$c_rdr>;
      print $reply;
   }
   print $c_wtr "\n";
   exit 0;
}

[download]

Output.

Hello, Sun
Hello, Moon
Hello, Wind
Hello, Air

[download]

Regards, Mario

In reply to Re: Creating a Pipe by marioroy
in thread Creating a Pipe by grjoe21

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