Linux下搭建一个简单的UDP通信

基础知识
UDP和TCP的区别：
1、TCP是面向连接的，而UDP是非面向连接的，因此TCP更可靠

2、UDP的server端的socket不需要监听
3、二者的server端都需要绑定

代码实现：
Server端：

/*************************************************************************
> File Name: server.c
> Author: HonestFox
> Mail: zhweizhi@foxmail.com
> Created Time: Sun 24 Jul 2016 09:23:45 PM CST
************************************************************************/

#include<stdio.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<string.h>
#include<unistd.h>
#include<netinet/in.h>
#include<stdlib.h>

static void usage(const char *proc)
{
printf("usage : %s  IP : %s\n", proc, proc);
}

int main(int argc, char *argv[])
{
if( argc != 3)
{
usage(argv[0]);
return 1;
}

int sock = socket(AF_INET, SOCK_DGRAM, 0);
if( sock < 0)
{
perror("socket");
exit(1);
}

//1.Create a Socket
struct sockaddr_in local;
local.sin_family = AF_INET;
local.sin_port = htons(atoi(argv[2]) );
local.sin_addr.s_addr = inet_addr(argv[1]);

//2.Bind
if(bind(sock, (struct sockaddr*)&local, sizeof(local) ) < 0)
{
perror("bind error");
return 2;
}

//3.Receive & Send
int done = 0;
struct sockaddr_in peer;
socklen_t len = sizeof(peer);
char buf[1024];
while(!done)
{
memset(buf, '\0', sizeof(buf));
recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr*)&peer, &len);
printf("client: %s\n", buf);
}

return 0;
}

Client端：

/*************************************************************************
> File Name: client.c
> Author: HonestFox
> Mail: zhweizhi@foxmail.com
> Created Time: Sun 24 Jul 2016 09:23:41 PM CST
************************************************************************/
#include<stdio.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<string.h>
#include<netinet/in.h>
#include<unistd.h>
#include<stdlib.h>
static void usage(const char *proc)
{
printf("usage : %s  IP : %s\n", proc, proc);
}

int main(int argc, char *argv[])
{
if( argc != 3)
{
usage(argv[0]);
return 1;
}

int sock = socket(AF_INET, SOCK_DGRAM, 0);
if( sock < 0)
{
perror("socket");
exit(1);
}

//1.Create a Socket
struct sockaddr_in remote;
remote.sin_family = AF_INET;
remote.sin_port = htons(atoi(argv[2]) );
remote.sin_addr.s_addr = inet_addr(argv[1]);

//2.No Need to Bind

//3 Send & Receive
int done = 0;
struct sockaddr_in peer;
socklen_t len = sizeof(peer);
char buf[1024];
while(!done)
{
memset(buf, '\0', sizeof(buf));
printf("plz enter: ");
fflush(stdout);
ssize_t _s = read(0, buf, sizeof(buf) - 1);
if(_s > 0)
{
buf[_s - 1] = '\0';
sendto(sock, buf, sizeof(buf), 0, (struct sockaddr*)&remote, sizeof(remote));
memset(buf, '\0', sizeof(buf));
}
}

return 0;
}

目前这段代码 仅仅是 一端能不断地向另一端发送数据，另一端会不断接收。
要想像即时通讯软件那样实现聊天的功能，还在研究ing