Update cgo-libzmq/README.md

cgo-libzmq/README.md

@@ -82,4 +82,94 @@ func main(){
 		fmt.Printf("Received World %d\n", request_nbr)
 	}
 }
+```
+
+# multipart
+
+```go
+package main
+
+/*
+#cgo pkg-config: libzmq
+#include <zmq.h>
+#include <string.h>
+#include <stdlib.h>
+*/
+import "C"
+import (
+    "fmt"
+    "unsafe"
+    "time"
+)
+
+func sender(context unsafe.Pointer) {
+    socket, _ := C.zmq_socket(context, C.ZMQ_PUSH)
+    defer C.zmq_close(socket)
+
+    C.zmq_connect(socket, C.CString("tcp://localhost:5555"))
+
+    // Sending a multi-part message
+    var message C.zmq_msg_t
+
+    // First part
+    C.zmq_msg_init_size(&message, C.size_t(5))
+    C.memcpy(C.zmq_msg_data(&message), unsafe.Pointer(C.CString("Hello")), C.size_t(5))
+    C.zmq_msg_send(&message, socket, C.ZMQ_SNDMORE)
+    C.zmq_msg_close(&message)
+
+    // Second part
+    C.zmq_msg_init_size(&message, C.size_t(6))
+    C.memcpy(C.zmq_msg_data(&message), unsafe.Pointer(C.CString("World!")), C.size_t(6))
+    C.zmq_msg_send(&message, socket, C.ZMQ_SNDMORE)
+    C.zmq_msg_close(&message)
+
+    // Last part
+    C.zmq_msg_init_size(&message, C.size_t(3))
+    C.memcpy(C.zmq_msg_data(&message), unsafe.Pointer(C.CString("End")), C.size_t(3))
+    C.zmq_msg_send(&message, socket, 0)
+    C.zmq_msg_close(&message)
+}
+
+func receiver(context unsafe.Pointer) {
+    socket, _ := C.zmq_socket(context, C.ZMQ_PULL)
+    defer C.zmq_close(socket)
+
+    C.zmq_bind(socket, C.CString("tcp://*:5555"))
+
+    for {
+        var message C.zmq_msg_t
+        C.zmq_msg_init(&message)
+
+        more := C.int(1)
+        moreSize := C.size_t(unsafe.Sizeof(more))
+        part := 0
+
+        for more != 0 {
+            C.zmq_msg_recv(&message, socket, 0)
+
+            size := C.zmq_msg_size(&message)
+            data := C.GoBytes(C.zmq_msg_data(&message), C.int(size))
+
+            part++
+            fmt.Printf("Received part %d: %s\n", part, string(data))
+
+            C.zmq_getsockopt(socket, C.ZMQ_RCVMORE, unsafe.Pointer(&more), &moreSize)
+            C.zmq_msg_close(&message)
+
+            if more != 0 {
+                C.zmq_msg_init(&message)
+            }
+        }
+        fmt.Println("End of multipart message\n")
+    }
+}
+
+func main() {
+    context, _ := C.zmq_ctx_new()
+    defer C.zmq_ctx_destroy(context)
+
+    go sender(context)
+    time.Sleep(time.Second) // Give some time for the sender to connect
+    receiver(context)
+}
 ```