Merge pull request #503 from luoliwoshang/c/socket/client

llgo/c/socket:client demo

_demo/socket/client/client.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"unsafe"
+
+	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/os"
+	"github.com/goplus/llgo/c/socket"
+)
+
+func main() {
+	sockfd := socket.Socket(socket.AF_INET, socket.SOCK_STREAM, 0)
+	msg := c.Str("Hello, World!")
+	defer os.Close(sockfd)
+
+	server := socket.GetHostByName(c.Str("localhost"))
+	if server == nil {
+		c.Perror(c.Str("hostname get error"))
+		return
+	}
+
+	servAddr := &socket.SockaddrIn{}
+	servAddr.Family = socket.AF_INET
+	servAddr.Port = socket.Htons(uint16(1234))
+	c.Memcpy(unsafe.Pointer(&servAddr.Addr.Addr), unsafe.Pointer(*server.AddrList), uintptr(server.Length))
+
+	if res := socket.Connect(sockfd, (*socket.SockAddr)(unsafe.Pointer(servAddr)), c.Uint(16)); res < 0 {
+		c.Perror(c.Str("connect error"))
+		return
+	}
+	os.Write(sockfd, unsafe.Pointer(msg), c.Strlen(msg))
+}