client.p6

#!/usr/bin/env perl6

use Readline;

use v6.c;

my $readline = Readline.new;

sub MAIN(Int $port) {
    await IO::Socket::Async.connect('127.0.0.1', $port).then( -> $p {
        if $p.status {
            given $p.result {
                say "CONNECT OK => ", $p.result;
                sub read-from-user() {
                    while $readline.readline("==>") -> $line {
                        $p.result.print($line ~ "\n");
                        { $p.result.close(); return } if $line eq 'exit';
                    }
                }
                supply {
                    whenever .Supply() -> $v {
                        printf("\r%s==>", $v);
                    }
                }.tap;
                &read-from-user();
                .close;
            }
        }
    });
}

server

#!/usr/bin/env perl6

class Shell {
	has Proc::Async $.proc handles <say print write stdout stderr started ready>;
	has Promise $.promise handles <Supply>;

	method new($bash = 'zsh', :$enc = 'utf8') {
		self.bless(proc => Proc::Async.new($bash, :w, :$enc));
	}

	method start() {
		unless $!promise {
			$!promise = $!proc.start;
		}
		$!promise;
	}
}

multi sub await(Shell:D $shell) {
	await $shell.promise;
}

sub processOutput(Supply $supply, $conn) {
	supply {
		whenever $supply -> $msg {
			emit $msg;
		}
	}
}

sub start-server($port) {
	react {
		whenever IO::Socket::Async.listen('0.0.0.0', $port) -> $conn {
			my $shell = Shell.new;
			
			sub tapOutput($v) { print "GOT => \n|", $v, "|\n"; $conn.print: $v; }	

			&processOutput($shell.stdout, $conn).tap(&tapOutput);
			&processOutput($shell.stderr, $conn).tap(&tapOutput);

			"GOT A CONNECTION ".say;
			$shell.start;
			whenever $conn.Supply(:bin) -> $buf {
				await $shell.write($buf);
				LAST {
					default {
                        $conn.close();
						"CONNECT CLOSED".say;
					}
				}
			}
		}
	}
}

sub MAIN(Int $port) {
	start-server($port);
}

under bash on win10:

GOT A CONNECTION
Tried to get the result of a broken Promise
in sub start-server at ./shell-server.p6 line 32
in sub MAIN at ./shell-server.p6 line 56
in block <unit> at ./shell-server.p6 line 56

Original exception:
    Tried to get the result of a broken Promise
    in block  at ./shell-server.p6 line 44

    Original exception:
        broken pipe
        in block  at ./shell-server.p6 line 44