Distributed programming: Difference between revisions

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server.ads:
<langsyntaxhighlight Adalang="ada">package Server is
pragma Remote_Call_Interface;
procedure Foo;
function Bar return Natural;
end Server;</langsyntaxhighlight>
 
server.adb:
<langsyntaxhighlight Adalang="ada">package body Server is
Count : Natural := 0;
 
Line 35:
return Count;
end Bar;
end Server;</langsyntaxhighlight>
 
client.adb:
<langsyntaxhighlight Adalang="ada">with Server;
with Ada.Text_IO;
 
Line 46:
Server.Foo;
Ada.Text_IO.Put_Line ("Calling Bar: " & Integer'Image (Server.Bar));
end Client;</langsyntaxhighlight>
 
required config (dsa.cfg):
<langsyntaxhighlight Adalang="ada">configuration DSA is
pragma Starter (None);
 
Line 61:
procedure Client;
for Client_Partition'Main use Client;
end DSA;</langsyntaxhighlight>
 
compilation:
Line 118:
 
=={{header|C}}==
Using PVM [[http://www.csm.ornl.gov/pvm/pvm_home.html]
This program is in a sense both a server and a client, depending on if its task is spawned with a command-line argument: if yes, it spawns another task of the same executible on the parallel virtual machine and waits for it to transmit data; if no, it transmits data and is done.
<langsyntaxhighlight Clang="c">#include <stdio.h>
#include <stdlib.h>
#include <pvm3.h>
Line 169:
pvm_exit();
return 0;
}</langsyntaxhighlight>Running{{out}}(running it: (on PVM console, exe is /tmp/a.out)<syntaxhighlight lang="text">pvm> spawn -> /tmp/a.out 1
spawn -> /tmp/a.out 1
[2]
Line 179:
[2:t40028] got msg type 1: 1804289383 0.394383
[2:t40028] EOF
[2] finished</langsyntaxhighlight>
 
=={{header|C sharp|C#}}==
Start the program with "server" parameter to start the server, and "client" to start the client. The client will send data to the server and receive a response. The server will wait for data, display the data received, and send a response.
{{incorrect|C sharp|The protocol used is not sufficiently general-purpose.}}
The example server can handle one client at any one time. It will read what the client writes, and respond with "Hello World!". The client will write "Hello World!" and read the response from the server.
 
<syntaxhighlight lang="csharp">
===Server===
using System;
<lang csharp>
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading.Tasks;
 
using static System.Console;
 
class ProgramDistributedProgramming
{
const int Port = 555;
static void Main(string[] args)
{
TcpListener server = new TcpListener(8000);
server.Start();
 
async static Task RunClient()
Console.WriteLine("Listening, port 8000");
{
WriteLine("Connecting");
var client = new TcpClient();
await client.ConnectAsync("localhost", Port);
 
using (var stream = client.GetStream())
TcpClient client;
{
do
WriteLine("Sending loot");
{
var data = Serialize(new SampleData());
// Accept client
await stream.WriteAsync(data, 0, data.Length);
client = server.AcceptTcpClient();
Console.WriteLine("Recieved client: " + client.Client.AddressFamily.ToString());
 
WriteLine("Receiving thanks");
// Recieve
var buffer = new byte[80000];
string tRecieve = "";
var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
char t;
var thanks = (string)Deserialize(buffer, bytesRead);
do
WriteLine(thanks);
{
}
if (client.Available > 0)
{
t = (char)client.GetStream().ReadByte();
 
client.Close();
if (t == 0)
}
break;
 
async static Task RunServer()
tRecieve += t;
{
}
WriteLine("Listening");
} while (true);
var listener = new TcpListener(IPAddress.Any, Port);
listener.Start();
var client = await listener.AcceptTcpClientAsync();
 
using (var stream = client.GetStream())
Console.WriteLine("Recieved: " + tRecieve);
{
WriteLine("Receiving loot");
var buffer = new byte[80000];
var bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
var data = (SampleData)Deserialize(buffer, bytesRead);
WriteLine($"{data.Loot} at {data.Latitude}, {data.Longitude}");
 
WriteLine("Sending thanks");
// Send
var thanks = Serialize("Thanks!");
byte[] tSend = Encoding.ASCII.GetBytes("Hello World!");
client.GetStream() await stream.WriteWriteAsync(tSendthanks, 0, tSendthanks.Length);
}
client.GetStream().WriteByte(0);
 
client.Close();
Console.WriteLine("Sent: " + Encoding.ASCII.GetString(tSend));
listener.Stop();
Write("Press a key");
ReadKey();
}
 
static byte[] Serialize(object data)
// Close
{
client.Close();
using (var mem = new MemoryStream())
} while (true);
{
new BinaryFormatter().Serialize(mem, data);
return mem.ToArray();
}
}
 
static object Deserialize(byte[] data, int length)
}
{
}
using (var mem = new MemoryStream(data, 0, length))
</lang>
{
return new BinaryFormatter().Deserialize(mem);
}
}
 
static void Main(string[] args)
===Client===
{
<lang csharp>
if (args.Length == 0) return;
using System.Net.Sockets;
 
switch (args[0])
class Program
{
{
case "client": RunClient().Wait(); break;
static void Main(string[] args)
case "server": RunServer().Wait(); break;
{
}
TcpClient client;
}
 
}
// Connect
do
{
client = new TcpClient();
client.Connect(new System.Net.IPEndPoint(System.Net.IPAddress.Parse("127.0.0.1"), 8000));
 
Console.WriteLine("Connected");
 
[Serializable]
// Send
class SampleData
byte[] tSend = Encoding.ASCII.GetBytes("Hello World!");
{
client.GetStream().Write(tSend, 0, tSend.Length);
public decimal Latitude = 44.33190m;
client.GetStream().WriteByte(0);
public decimal Longitude = 114.84129m;
 
public string Loot = "140 tonnes of jade";
Console.WriteLine("Sent: " + Encoding.ASCII.GetString(tSend));
 
// Read
string tRecieve = "";
char t;
do
{
if (client.Available > 0)
{
t = (char)client.GetStream().ReadByte();
 
if (t == 0)
break;
 
tRecieve += t;
}
} while (true);
 
Console.WriteLine("Recieved: " + tRecieve);
 
client.Close();
 
Console.Read();
} while (true);
}
}
</syntaxhighlight>
</lang>
 
=={{header|D}}==
Line 294 ⟶ 289:
 
This library is not standard, so this code (by Adam D. Ruppe) could and should be rewritten using more standard means.
<langsyntaxhighlight lang="d">import arsd.rpc;
 
struct S1 {
Line 360 ⟶ 355:
server.eventLoop;
}
}</langsyntaxhighlight>
 
=={{header|E}}==
Line 371 ⟶ 366:
(The protocol is symmetric; this program is the server only in that it is the one which is started first and exports an object.)
 
<langsyntaxhighlight Elang="e">def storage := [].diverge()
 
def logService {
Line 389 ⟶ 384:
def sturdyRef := makeSturdyRef.temp(logService)
println(<captp>.sturdyToURI(sturdyRef))
interp.blockAtTop()</langsyntaxhighlight>
 
This will print the URL of the service and run it until aborted.
Line 397 ⟶ 392:
The URL provided by the server is given as the argument to this program.
 
<langsyntaxhighlight Elang="e">def [uri] := interp.getArgs()
introducer.onTheAir()
def sturdyRef := <captp>.sturdyFromURI(uri)
Line 410 ⟶ 405:
println(`At $time: $line`)
}
}</langsyntaxhighlight>
 
=={{header|Erlang}}==
Line 417 ⟶ 412:
srv.erl
 
<langsyntaxhighlight lang="erlang">-module(srv).
-export([start/0, wait/0]).
 
Line 435 ⟶ 430:
wait();
Any -> io:fwrite("Error ~p~n", [Any])
end.</langsyntaxhighlight>
 
=== Client ===
client.erl
 
<langsyntaxhighlight lang="erlang">-module(client).
-export([start/0, wait/0]).
 
Line 456 ⟶ 451:
{hello, Any} -> io:fwrite("Received ~p~n", [Any]);
Any -> io:fwrite("Error ~p~n", [Any])
end.</langsyntaxhighlight>
 
running it (*comes later)
Line 479 ⟶ 474:
 
===Server===
<langsyntaxhighlight lang="factor">USING: concurrency.distributed concurrency.messaging threads io.sockets io.servers ;
QUALIFIED: concurrency.messaging
: prettyprint-message ( -- ) concurrency.messaging:receive . flush prettyprint-message ;
[ prettyprint-message ] "logger" spawn dup name>> register-remote-thread
"127.0.0.1" 9000 <inet4> <node-server> start-server</langsyntaxhighlight>
 
Note: we are using QUALIFIED: with the concurrency.messaging vocabulary because the "receive" word is defined in io.sockets vocabulary too. If someone have a cleaner way to handle this.
 
===Client===
<langsyntaxhighlight lang="factor">USING: concurrency.distributed io.sockets ;
QUALIFIED: concurrency.messaging
{ "Hello Remote Factor!" H{ { "key1" "value1" } } }
"127.0.0.1" 9000 <inet4> "logger" <remote-thread> concurrency.messaging:send</langsyntaxhighlight>
 
How to Run:
Line 502 ⟶ 497:
 
=={{header|Go}}==
===Standard library net/rpc===
Package net/rpc in the Go standard library serializes data with the Go-native "gob" type. The example here sends only a single floating point number, but the package will send any user-defined data type, including of course structs with multiple fields.
 
===Server===
'''Server:'''
<lang go>package main
<syntaxhighlight lang="go">package main
 
import (
Line 533 ⟶ 530:
}
http.Serve(listener, nil)
}</langsyntaxhighlight>
==='''Client===:'''
<langsyntaxhighlight lang="go">package main
 
import (
Line 557 ⟶ 554:
}
fmt.Printf("Tax on %.2f: %.2f\n", amount, tax)
}</langsyntaxhighlight>
{{out | Client output:}}
<pre>
Tax on 3.00: 0.15
</pre>
===gRPC===
See http://www.grpc.io/
 
The default serialization for gRPC is "protocol buffers." gRPC uses a .proto file to define an interface for the client and server. The .proto has its own syntax, independent of client and server implementation languages. Server and client programs here are Go however.
 
'''.proto:'''
<syntaxhighlight lang="proto">syntax = "proto3";
 
service TaxComputer {
rpc Tax(Amount) returns (Amount) {}
}
 
message Amount {
int32 cents = 1;
}</syntaxhighlight>
'''Server:'''
<syntaxhighlight lang="go">package main
 
import (
"errors"
"net"
 
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/grpclog"
 
"taxcomputer"
)
 
type taxServer struct {
rate float64
}
 
func (s *taxServer) Tax(ctx context.Context,
amt *taxcomputer.Amount) (*taxcomputer.Amount, error) {
if amt.Cents < 0 {
return nil, errors.New("Negative amounts not allowed")
}
return &taxcomputer.Amount{int32(float64(amt.Cents)*s.rate + .5)}, nil
}
 
func main() {
listener, err := net.Listen("tcp", ":1234")
if err != nil {
grpclog.Fatalf(err.Error())
}
grpcServer := grpc.NewServer()
taxcomputer.RegisterTaxComputerServer(grpcServer, &taxServer{.05})
grpcServer.Serve(listener)
}</syntaxhighlight>
'''Client:'''
<syntaxhighlight lang="go">package main
 
import (
"fmt"
 
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/grpclog"
 
"taxcomputer"
)
 
func main() {
conn, err := grpc.Dial("localhost:1234", grpc.WithInsecure())
if err != nil {
grpclog.Fatalf(err.Error())
}
defer conn.Close()
client := taxcomputer.NewTaxComputerClient(conn)
amt := &taxcomputer.Amount{300}
tax, err := client.Tax(context.Background(), amt)
if err != nil {
grpclog.Fatalf(err.Error())
}
fmt.Println("Tax on", amt.Cents, "cents is", tax.Cents, "cents")
}</syntaxhighlight>
{{out | Client output}}
<pre>
Tax on 300 cents is 15 cents
</pre>
 
===Apache Thrift===
See https://thrift.apache.org/
 
'''.thrift'''
 
Like gRPC, Thrift requires a language independent interface definition file:
<syntaxhighlight lang="thrift">service TaxService {
i32 tax(1: i32 amt)
}</syntaxhighlight>
'''Server:'''
<syntaxhighlight lang="go">package main
 
import (
"errors"
"log"
 
"git.apache.org/thrift.git/lib/go/thrift"
 
"gen-go/tax"
)
 
type taxHandler float64
 
func (r taxHandler) Tax(amt int32) (int32, error) {
if amt < 0 {
return 0, errors.New("Negative amounts not allowed")
}
return int32(float64(amt)*float64(r) + .5), nil
}
 
func main() {
transport, err := thrift.NewTServerSocket("localhost:3141")
if err != nil {
log.Fatal(err)
}
transFac := thrift.NewTTransportFactory()
protoFac := thrift.NewTCompactProtocolFactory()
proc := tax.NewTaxServiceProcessor(taxHandler(.05))
s := thrift.NewTSimpleServer4(proc, transport, transFac, protoFac)
if err := s.Serve(); err != nil {
log.Fatal(err)
}
}</syntaxhighlight>
'''Client:'''
<syntaxhighlight lang="go">package main
 
import (
"fmt"
"log"
 
"git.apache.org/thrift.git/lib/go/thrift"
 
"gen-go/tax"
)
 
func main() {
transport, err := thrift.NewTSocket("localhost:3141")
if err != nil {
log.Fatal(err)
}
if err := transport.Open(); err != nil {
log.Fatal(err)
}
protoFac := thrift.NewTCompactProtocolFactory()
client := tax.NewTaxServiceClientFactory(transport, protoFac)
amt := int32(300)
t, err := client.Tax(amt)
if err != nil {
log.Print(err)
} else {
fmt.Println("tax on", amt, "is", t)
}
transport.Close()
}</syntaxhighlight>
{{out | Client output}}
<pre>
tax on 300 is 15
</pre>
 
Line 578 ⟶ 735:
===Server===
 
<langsyntaxhighlight lang="javascript">var net = require('net')
 
var server = net.createServer(function (c){
Line 586 ⟶ 743:
 
server.listen(3000, 'localhost')
</syntaxhighlight>
</lang>
 
===Client===
<langsyntaxhighlight lang="javascript">var net = require('net')
 
conn = net.createConnection(3000, '192.168.1.x')
Line 600 ⟶ 757:
conn.on('data', function(msg){
console.log(msg.toString())
})</langsyntaxhighlight>
 
=={{header|Julia}}==
Julia was designed with distributed conmputing. in particular cluster computing, as a primary use target.
If a group of CPUs, including multiple cores on a single machine or a cluster running with paswordless ssh login, is used,
the following can be set up as an example:
<syntaxhighlight lang="julia"># From Julia 1.0's online docs. File countheads.jl available to all machines:
 
function count_heads(n)
c::Int = 0
for i = 1:n
c += rand(Bool)
end
c
end</syntaxhighlight>
We then run the following on the primary client:
<syntaxhighlight lang="julia">
using Distributed
@everywhere include_string(Main, $(read("count_heads.jl", String)), "count_heads.jl")
 
a = @spawn count_heads(100000000) # runs on an available processor
b = @spawn count_heads(100000000) # runs on another available processor
 
println(fetch(a)+fetch(b)) # total heads of 200 million coin flips, half on each CPU
</syntaxhighlight> {{output}} <pre>
100001564
</pre>
 
=={{header|LFE}}==
Line 612 ⟶ 795:
In one terminal window, start up the REPL
 
<langsyntaxhighlight lang="bash">
$ ./bin/lfe
Erlang/OTP 17 [erts-6.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
Line 618 ⟶ 801:
LFE Shell V6.2 (abort with ^G)
>
</syntaxhighlight>
</lang>
 
And then enter the following code
 
<langsyntaxhighlight lang="lisp">
> (defun get-server-name ()
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname)))))
Line 642 ⟶ 825:
(x
(io:format "Unexpected pattern: ~p~n" `(,x)))))
</syntaxhighlight>
</lang>
 
===Client===
Line 648 ⟶ 831:
In another terminal window, start up another LFE REPL and ender the following code:
 
<langsyntaxhighlight lang="lisp">
> (defun get-server-name ()
(list_to_atom (++ "exampleserver@" (element 2 (inet:gethostname)))))
Line 663 ⟶ 846:
(io:format "Unexpected pattern: ~p~n" (list x))))
'ok)
</syntaxhighlight>
</lang>
 
To use this code, simply start the server in the server terminal:
 
<langsyntaxhighlight lang="lisp">
> (start)
exampleserver@yourhostname ready
ok
(exampleserver@yourhostname)>
</syntaxhighlight>
</lang>
 
Send some messages from the client terminal:
 
<langsyntaxhighlight lang="lisp">
> (send "hi there")
connecting to exampleserver@yourhostname
Line 690 ⟶ 873:
ok
(exampleclient@yourhostname)>
</syntaxhighlight>
</lang>
 
And check out the results back in the server terminal window:
 
<langsyntaxhighlight lang="lisp">
Got "hi there" from exampleclient@yourhostname
Got 42 from exampleclient@yourhostname
Got {key,value} from exampleclient@yourhostname
</syntaxhighlight>
</lang>
 
=={{header|Mathematica}} / {{header|Wolfram Language}}==
The following sends a request for a random number to be generated on each of two nodes, these are then transmitted back to be assembled into an array with two elements. Omitting the first line, will cause the program to be run on all configured remote computers.
<langsyntaxhighlight Mathematicalang="mathematica">LaunchKernels[2];
ParallelEvaluate[RandomReal[]]
</syntaxhighlight>
</lang>
 
=={{header|Nim}}==
{{libheader|nanomsg}}
<langsyntaxhighlight lang="nim">import os, nanomsg
 
proc sendMsg(s: cint, msg: string) =
echo "SENDING \"",msg,"\""
let bytes = s.send(msg.cstring, msg.len + 1, 0)
assert bytes == msg.len + 1
 
proc recvMsg(s: cint) =
var buf: cstring
let bytes = s.recv(addr buf, MSG, 0)
Line 722 ⟶ 905:
discard freemsg buf
 
proc sendRecv(s: cint, msg: string) =
var to: cint = 100
discard s.setSockOpt(SOL_SOCKET, RCVTIMEO, addr to, sizeof to)
Line 749 ⟶ 932:
node0 paramStr(2)
elif paramStr(1) == "node1":
node1 paramStr(2)</langsyntaxhighlight>
Usage:
<pre>./pair node0 tcp://127.0.0.1:25000
Line 762 ⟶ 945:
 
<tt>ActionObjectProtocol.h</tt>
<langsyntaxhighlight lang="objc">#import <Foundation/Foundation.h>
// our protocol allows "sending" "strings", but we can implement
// everything we could for a "local" object
@protocol ActionObjectProtocol
- (NSString *)sendMessage: (NSString *)msg;
@end</langsyntaxhighlight>
 
<tt>ActionObject.h</tt>
<langsyntaxhighlight lang="objc">#import <Foundation/Foundation.h>
#import "ActionObjectProtocol.h"
 
@interface ActionObject : NSObject <ActionObjectProtocol>
// we do not have much for this example!
@end</langsyntaxhighlight>
 
<tt>ActionObject.m</tt>
<langsyntaxhighlight lang="objc">#import <Foundation/Foundation.h>
#import "ActionObject.h"
 
Line 787 ⟶ 970:
return @"server answers ...";
}
@end</langsyntaxhighlight>
 
<tt>server.m</tt>
<langsyntaxhighlight lang="objc">#import <Foundation/Foundation.h>
#import "ActionObject.h"
 
Line 824 ⟶ 1,007:
}
return 0;
}</langsyntaxhighlight>
 
===Client===
<tt>client.m</tt>
<langsyntaxhighlight lang="objc">#import <Foundation/Foundation.h>
#import "ActionObjectProtocol.h"
 
Line 865 ⟶ 1,048:
}
return 0;
}</langsyntaxhighlight>
 
=={{header|OCaml}}==
Line 873 ⟶ 1,056:
 
=== Server ===
<langsyntaxhighlight lang="ocaml">open Printf
let create_logger () =
Line 895 ⟶ 1,078:
register "search" search;
Join.Site.listen (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345));
wait ()</langsyntaxhighlight>
 
=== Client ===
 
<langsyntaxhighlight lang="ocaml">open Printf
let ns_there = Join.Ns.there (Unix.ADDR_INET (Join.Site.get_local_addr(), 12345))
Line 919 ⟶ 1,102:
log "foo";
log "shoe";
find "foo"</langsyntaxhighlight>
 
=={{header|Oz}}==
We show a program that starts a server on a remote machine, exchanges two messages with that server and finally shuts it down.
 
<langsyntaxhighlight lang="oz">declare
functor ServerCode
export
Line 963 ⟶ 1,146:
 
%% shut down server
{RM close}</langsyntaxhighlight>
 
=={{header|Perl}}==
Using Data::Dumper and Safe to transmit arbitrary data structures as serialized text between hosts. Same code works as both sender and receiver.
<syntaxhighlight lang="perl">use strict;
<lang Perl>use Data::Dumper;
use warnings;
use Data::Dumper;
use IO::Socket::INET;
use Safe;
 
sub get_data {
my $sock = new IO::Socket::INET->new(
LocalHost => "localhost",
LocalPort => "10000",
Proto => "tcp",
Listen => 1,
Reuse => 1);
unless ($sock) { die "Socket creation failure" }
my $cli = $sock->accept();
Line 983 ⟶ 1,168:
# of course someone may be tempted to send you 'system("rm -rf /")',
# to be safe(r), use Safe::
my $safe = new Safe->new;
my $x = $safe->reval(join("", <$cli>));
close $cli;
Line 993 ⟶ 1,178:
my $host = shift;
my $data = shift;
my $sock = new IO::Socket::INET->new(
PeerAddr => "$host:10000",
Proto => "tcp",
Reuse => 1);
 
unless ($sock) { die "Socket creation failure" }
Line 1,009 ⟶ 1,194:
} else {
send_data('some_host', { a=>100, b=>[1 .. 10] });
}</langsyntaxhighlight>
 
=={{header|Phix}}==
From/using [http://phix.x10.mx/pmwiki/pmwiki.php?n=Main.Libzmq the ZeroMQ wrapper from PCAN], a suitable simple publish/subscriber pair.
There is also a server/client/broker example.
Obviously you can trivially serialize() and deserialize() any Phix data to and from a string.
<!--<syntaxhighlight lang="phix">(notonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (zmq dll/so)</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"durapub:\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">zmq</span><span style="color: #0000FF;">/</span><span style="color: #000000;">zmq</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">context</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_assert</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"zmq_init"</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// subscriber tells us when it's ready here</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">sync</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PULL</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_bind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://*:5564"</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// send update via this socket</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">publisher</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PUB</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_bind</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://*:5565"</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// broadcast 10 updates, with pause</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">update_nbr</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">10</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Update %d"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">update_nbr</span> <span style="color: #0000FF;">})</span>
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"END"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">sleep</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">publisher</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_term</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->
 
<!--<syntaxhighlight lang="phix">(notonline)-->
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (zmq dll/so)</span>
<span style="color: #7060A8;">puts</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"durasub:\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">zmq</span><span style="color: #0000FF;">/</span><span style="color: #000000;">zmq</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">context</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_init</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_assert</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"zmq_init"</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// connect our subscriber socket</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">subscriber</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_SUB</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">id</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">allocate_string</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"Hello"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_setsockopt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_IDENTITY</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">id</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_setsockopt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_SUBSCRIBE</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_connect</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://localhost:5565"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">free</span><span style="color: #0000FF;">(</span><span style="color: #000000;">id</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// synchronise with publisher</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">sync</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_socket</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ZMQ_PUSH</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_connect</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"tcp://localhost:5564"</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_s_send</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">""</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--// get updates, Ctrl-C break</span>
<span style="color: #008080;">while</span> <span style="color: #004600;">true</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">zmq_s_recv</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"%s\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">s</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">==</span><span style="color: #008000;">"END"</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sync</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_close</span><span style="color: #0000FF;">(</span><span style="color: #000000;">subscriber</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">zmq_term</span><span style="color: #0000FF;">(</span><span style="color: #000000;">context</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->
 
=={{header|PicoLisp}}==
===Server===
<langsyntaxhighlight PicoLisplang="picolisp">(task (port 12321) # Background server task
(let? Sock (accept @)
(unless (fork) # Handle request in child process
Line 1,020 ⟶ 1,274:
(pr (eval @)) ) ) ) # Evaluate and send reply
(bye) ) # Exit child process
(close Sock) ) ) # Close socket in parent process</langsyntaxhighlight>
===Client===
<langsyntaxhighlight PicoLisplang="picolisp">(let? Sock (connect "localhost" 12321)
(out Sock (pr '*Pid)) # Query PID from server
(println 'PID (in Sock (rd))) # Receive and print reply
(out Sock (pr '(* 3 4))) # Request some calculation
(println 'Result (in Sock (rd))) # Print result
(close Sock) ) # Close connection to server</langsyntaxhighlight>
Output:
<pre>PID 18372
Line 1,039 ⟶ 1,293:
 
==== Server ====
<langsyntaxhighlight lang="python">#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
Line 1,076 ⟶ 1,330:
except KeyboardInterrupt:
print 'Exiting...'
server.server_close()</langsyntaxhighlight>
 
==== Client ====
<langsyntaxhighlight lang="python">#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
Line 1,101 ⟶ 1,355:
# control if foo_function returns True
if rpc.foo_function():
print 'Server says: foo_function returned True'</langsyntaxhighlight>
 
===HTTP===
Line 1,107 ⟶ 1,361:
 
==== Server ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,136 ⟶ 1,390:
except KeyboardInterrupt:
print 'Exiting...'
server.server_close()</langsyntaxhighlight>
 
==== Client ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,153 ⟶ 1,407:
print 'Server Status: %d' % response.status
 
print 'Server Message: %s' % response.read()</langsyntaxhighlight>
 
===Socket, Pickle format===
Line 1,162 ⟶ 1,416:
 
==== Server ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
Line 1,219 ⟶ 1,473:
print 'Exiting...'
rpcserver.server_close()
</syntaxhighlight>
</lang>
 
==== Client ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
Line 1,276 ⟶ 1,530:
print '42/2 is:', rpcclient.div(divisor=2, dividend=42)
rpcclient._close()
del rpcclient</langsyntaxhighlight>
 
===Pyro===
Line 1,282 ⟶ 1,536:
 
==== Server ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,307 ⟶ 1,561:
except KeyboardInterrupt:
print 'Exiting...'
server.shutdown()</langsyntaxhighlight>
 
==== Client ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,326 ⟶ 1,580:
 
print 'We sent two numbers to divide: %d and %d' % (NUM1, NUM2)
print 'Server responded the result: %s' % math.div(NUM1, NUM2)</langsyntaxhighlight>
 
=== Spread ===
Line 1,337 ⟶ 1,591:
 
==== Client (Listener) ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,354 ⟶ 1,608:
if hasattr(recv, 'sender') and hasattr(recv, 'message'):
print 'Sender: %s' % recv.sender
print 'Message: %s' % recv.message</langsyntaxhighlight>
 
==== Client (Sender) ====
<langsyntaxhighlight lang="python">#!/usr/bin/python
# -*- coding: utf-8 -*-
 
Line 1,368 ⟶ 1,622:
 
conn.multicast(spread.RELIABLE_MESS, 'test', 'hello, this is message sent from python')
conn.disconnect()</langsyntaxhighlight>
 
=={{header|Racket}}==
Server and client in the same piece of code, running a useless (fib 42) computation, four times, on four hosts (which all happen to be "localhost", but that can change, of course).
 
<langsyntaxhighlight lang="racket">
#lang racket/base
(require racket/place/distributed racket/place)
Line 1,398 ⟶ 1,652:
(printf "Results: ~s\n" (map *channel-get places))
(exit))))
</syntaxhighlight>
</lang>
 
=={{header|Raku}}==
(formerly Perl 6)
 
Server listens for JSON encoded messages. It processes requests for set|get|dump. 'set' stores a message, 'get' returns message, 'dump' returns all stored messages. Optional parameters for ip address and port.
 
Server.raku:
<pre>./server.raku --usage
Usage:
server.p6 [--server=<Any>] [--port=<Any>]</pre>
<syntaxhighlight lang="raku" line>#!/usr/bin/env raku
use JSON::Fast ;
sub MAIN( :$server='0.0.0.0' , :$port=3333 ) {
my %db ;
react {
whenever IO::Socket::Async.listen( $server , $port ) -> $conn {
whenever $conn.Supply.lines -> $line {
my %response = 'status' => '' ;
my $msg = from-json $line ;
say $msg.raku;
given $msg{"function"} {
when 'set' {
%db{ $msg<topic> } = $msg<message> ;
%response<status> = 'ok' ;
}
when 'get' {
%response<topic> = $msg<topic> ;
%response<message> = %db{ $msg<topic> } ;
%response<status> = 'ok' ;
}
when 'dump' {
%response = %db ;
}
when 'delete' {
%db{ $msg<topic> }:delete;
%response<status> = 'ok' ;
}
}
$conn.print( to-json(%response, :!pretty) ~ "\n" ) ;
LAST { $conn.close ; }
QUIT { default { $conn.close ; say "oh no, $_";}}
CATCH { default { say .^name, ': ', .Str , " handled in $?LINE";}}
}
}
}
}</syntaxhighlight>
client.raku:
<pre>Usage:
client.raku [--server=<Any>] [--port=<Any>] [--json=<Any>] set <topic> [<message>]
client.raku [--server=<Any>] [--port=<Any>] get <topic>
client.raku [--server=<Any>] [--port=<Any>] dump</pre>
<syntaxhighlight lang="raku" line>#!/usr/bin/env raku
use JSON::Fast ;
multi MAIN('set', $topic, $message='', :$server='localhost', :$port='3333', :$json='') {
my %msg = function => 'set' , topic=> $topic , message=> $message ;
%msg{"message"} = from-json( $json ) if $json ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('get', $topic, :$server='localhost', :$port='3333') {
my %msg = function => 'get' , topic=> $topic ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('delete', $topic, :$server='localhost', :$port='3333') {
my %msg = function => 'delete' , topic=> $topic ;
sendmsg( %msg , $server, $port) ;
}
multi MAIN('dump', :$server='localhost', :$port='3333') {
my %msg = function => 'dump' ;
sendmsg( %msg , $server, $port) ;
}
sub sendmsg( %msg , $server, $port){
my $conn = await IO::Socket::Async.connect( $server , $port );
$conn.print: to-json( %msg,:!pretty)~"\n";
react {
whenever $conn.Supply -> $data {
print $data;
$conn.close;
}
}
}</syntaxhighlight>
examples:
<pre>echo '{"function":"set","topic":"push","message":["perl5","raku","rakudo"]}' | nc localhost 3333
 
./client.raku set version raku
{"status": "ok"}
./client.raku get version
{"status": "ok","topic": "version","message": "raku"}
./client.raku --json='["one","two","three"]' set mylist
{"status": "ok"}
./client.raku dump
{"push": ["perl5","raku","rakudo"],"version": "raku","mylist": ["one","two","three"]}
./client.raku delete version
{"status": "ok"}
 
server output:
${:function("set"), :message($["perl5", "raku", "rakudo"]), :topic("push")}
${:function("set"), :message("raku"), :topic("version")}
${:function("get"), :topic("version")}
${:function("set"), :message($["one", "two", "three"]), :topic("mylist")}
${:function("dump")}
${:function("delete"), :topic("version")}</pre>
 
=={{header|Ruby}}==
Line 1,404 ⟶ 1,759:
 
'''Server'''
<langsyntaxhighlight lang="ruby">require 'drb/drb'
 
# The URI for the server to connect to
Line 1,424 ⟶ 1,779:
DRb.start_service(URI, FRONT_OBJECT)
# Wait for the drb server thread to finish before exiting.
DRb.thread.join</langsyntaxhighlight>
 
'''Client'''
<langsyntaxhighlight lang="ruby">require 'drb/drb'
 
# The URI to connect to
Line 1,440 ⟶ 1,795:
 
timeserver = DRbObject.new_with_uri(SERVER_URI)
puts timeserver.get_current_time</langsyntaxhighlight>
 
=={{header|Tcl}}==
A rudimentary IRC Server
<langsyntaxhighlight lang="tcl">proc main {} {
global connections
set connections [dict create]
Line 1,506 ⟶ 1,861:
}
 
main</langsyntaxhighlight>
Client
<langsyntaxhighlight lang="tcl">proc main {} {
global argv argc
if {$argc != 2} {
Line 1,543 ⟶ 1,898:
}
 
main</langsyntaxhighlight>
 
=={{header|UnixPipes}}==
Line 1,552 ⟶ 1,907:
{{alertbox|yellow|'''Security risk!''' Anything, able to reach 127.0.0.1 port 1234, can run shell commands as the user who runs the server. This allows other users to gain privileges.}}
 
<langsyntaxhighlight lang="bash">: >/tmp/buffer
tail -f /tmp/buffer | nc -l 127.0.0.1 1234 | sh >/tmp/buffer 2>&1</langsyntaxhighlight>
 
Limitations:
Line 1,561 ⟶ 1,916:
 
===Client===
<langsyntaxhighlight lang="bash">nc 127.0.0.1 1234</langsyntaxhighlight>
 
Now you can enter commands in the client terminal and get the output back through the same connection.
 
=={{header|Wren}}==
{{trans|Go}}
{{libheader|WrenGo}}
{{libheader|Wren-fmt}}
As Wren has no networking support at present, we use embedded programs for both the server and client with a Go host using the net/rpc package in its standard library.
 
Moreover, as Wren's VM is not re-entrant, we need to run two VMs from the server side, one to call Go from Wren and the other to call Wren from Go.
 
'''Server:'''
<br>
We need two Wren scripts one for each VM:
<syntaxhighlight lang="wren">/* Distributed_programming_server.wren */
 
class Rpc {
foreign static register()
 
foreign static handleHTTP()
}
 
foreign class Listener {
construct listen(network, address) {}
}
 
class HTTP {
foreign static serve(listener)
}
 
Rpc.register()
Rpc.handleHTTP()
var listener = Listener.listen("tcp", ":1234")
HTTP.serve(listener)</syntaxhighlight>
<br>
<syntaxhighlight lang="wren">/* Distributed_programming_server_2.wren */
 
class TaxComputer {
static tax(amount, rate) {
if (amount < 0) Fiber.abort("Negative values not allowed.")
return amount * rate
}
}</syntaxhighlight>
<br>
We now embed these scripts in the following Go program and run it on one terminal.
<syntaxhighlight lang="go">/* go run Distributed_programming_server.go */
 
package main
 
import(
wren "github.com/crazyinfin8/WrenGo"
"log"
"net"
"net/http"
"net/rpc"
)
 
type any = interface{}
 
type TaxComputer float64
 
var vm2 *wren.VM
 
var fileName = "Distributed_programming_server.wren"
var fileName2 = "Distributed_programming_server_2.wren"
 
func (taxRate TaxComputer) Tax(x float64, r *float64) error {
wrenVar, _ := vm2.GetVariable(fileName2, "TaxComputer")
wrenClass, _ := wrenVar.(*wren.Handle)
defer wrenClass.Free()
wrenMethod, _ := wrenClass.Func("tax(_,_)")
defer wrenMethod.Free()
ret, _ := wrenMethod.Call(x, float64(taxRate))
*r = ret.(float64)
return nil
}
 
func register(vm *wren.VM, parameters []any) (any, error) {
c := TaxComputer(0.05) // 5% tax rate
rpc.Register(c)
return nil, nil
}
 
func handleHTTP(vm *wren.VM, parameters []any) (any, error) {
rpc.HandleHTTP()
return nil, nil
}
 
func serve(vm *wren.VM, parameters []any) (any, error) {
handle := parameters[1].(*wren.ForeignHandle)
ifc, _ := handle.Get()
listener := ifc.(*net.Listener)
http.Serve(*listener, nil)
return nil, nil
}
 
func listen(vm *wren.VM, parameters []any) (any, error) {
network := parameters[1].(string)
address := parameters[2].(string)
listener, err := net.Listen(network, address)
if err != nil {
log.Fatal(err)
}
return &listener, nil
}
 
func main() {
vm := wren.NewVM()
vm2 = wren.NewVM()
vm2.InterpretFile(fileName2)
 
rpcMethodMap := wren.MethodMap {
"static register()": register,
"static handleHTTP()": handleHTTP,
}
 
httpMethodMap := wren.MethodMap { "static serve(_)":serve }
 
classMap := wren.ClassMap {
"Listener": wren.NewClass(listen, nil, nil),
"Rpc" : wren.NewClass(nil, nil, rpcMethodMap),
"HTTP" : wren.NewClass(nil, nil, httpMethodMap),
}
 
module := wren.NewModule(classMap)
vm.SetModule(fileName, module)
vm.InterpretFile(fileName)
vm.Free()
vm2.Free()
}</syntaxhighlight>
<br>
'''Client:'''
<br>
Just one Wren script needed here:
<syntaxhighlight lang="wren">/* Distributed_programming_client.wren */
 
import "./fmt" for Fmt
 
foreign class Client {
construct dialHTTP(network, address) {}
 
foreign call(serviceMethod, arg)
}
 
var client = Client.dialHTTP("tcp", "localhost:1234")
var amounts = [3, 5.6]
for (amount in amounts) {
var tax = client.call("TaxComputer.Tax", amount)
Fmt.print("Tax on $0.2f = $0.2f", amount, tax)
}</syntaxhighlight>
<br>
which we embed in the following Go program and run it on a different terminal.
<syntaxhighlight lang="go">/* go run Distributed_programming_client.go */
 
package main
 
import(
wren "github.com/crazyinfin8/WrenGo"
"log"
"net/rpc"
"strings"
)
 
type any = interface{}
 
func dialHTTP(vm *wren.VM, parameters []any) (any, error) {
network := parameters[1].(string)
address := parameters[2].(string)
client, err := rpc.DialHTTP(network, address)
if err != nil {
log.Fatal(err)
}
return &client, nil
}
 
func call(vm *wren.VM, parameters []any) (any, error) {
handle := parameters[0].(*wren.ForeignHandle)
ifc, _ := handle.Get()
client := ifc.(**rpc.Client)
serviceMethod := parameters[1].(string)
amount := parameters[2].(float64)
var tax float64
err := (*client).Call(serviceMethod, amount, &tax)
if err != nil {
log.Fatal(err)
}
return tax, nil
}
 
func moduleFn(vm *wren.VM, name string) (string, bool) {
if name != "meta" && name != "random" && !strings.HasSuffix(name, ".wren") {
name += ".wren"
}
return wren.DefaultModuleLoader(vm, name)
}
 
func main() {
cfg := wren.NewConfig()
cfg.LoadModuleFn = moduleFn
vm := cfg.NewVM()
fileName := "Distributed_programming_client.wren"
clientMethodMap := wren.MethodMap { "call(_,_)": call }
classMap := wren.ClassMap { "Client": wren.NewClass(dialHTTP, nil, clientMethodMap) }
module := wren.NewModule(classMap)
vm.SetModule(fileName, module)
vm.InterpretFile(fileName)
vm.Free()
}</syntaxhighlight>
 
{{out}}
Output on the client terminal:
<pre>
Tax on 3.00 = 0.15
Tax on 5.60 = 0.28
</pre>
 
{{omit from|Lotus 123 Macro Scripting}}
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