socket编程学习之UDP模式

Love The Way You Lie 2021-10-15 07:36 368阅读 0赞

1、目的：根据[UDP编程模式][UDP]，编写一个可以进行通信的进程。

2、编写文件主要包括：

*  公共头文件：utili.h
 *  客户端进程：cli.c
 *  服务器进程：ser.c
 *  Makefile文件：Makefile

3、各个文件详细代码如下：

公共头文件：utili.h

#include<string.h>
    #include<stdlib.h>
    
    #include<sys/socket.h>
    #include<netinet/in.h>
    #include<arpa/inet.h>
    
    #define BUFFER_MAX_SIZE 256
    char sendbuf[BUFFER_MAX_SIZE];
    char recvbuf[BUFFER_MAX_SIZE];
    
    #define LISTEN_PORT 8080
    #define LISTEN_IP "127.0.0.1"
    
    #define LISTEN_BACKLOG 5
    
    int Socket(int domain, int type, int protocol)
    {
        int fd = socket(domain, type, protocol);
        if(fd == -1)
        {
            perror("socket.");
            exit(1);
        }
        return fd;
    }
    
    int Bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
    {
        int ret = bind(sockfd, addr, addrlen);
        if(ret == -1)
        {
            perror("bind.");
            exit(1);
        }
        return ret;
    }

服务器进程代码：ser.c

#include "utili.h"
    
    int main(int argc, char *argv[])
    {
        int sockSer = socket(AF_INET, SOCK_DGRAM, 0);
        if(sockSer == -1)
        {
            perror("socket.");
            exit(1);
        }
    
        struct sockaddr_in addrSer;
        addrSer.sin_family = AF_INET;
        addrSer.sin_port = htons(7070);
        addrSer.sin_addr.s_addr = INADDR_ANY;
    
        socklen_t addrlen = sizeof(struct sockaddr);
        bind(sockSer, (struct sockaddr*)&addrSer, addrlen);
    
        struct sockaddr_in addrCli;
    
        while(1)
        {
            recvfrom(sockSer, recvbuf, BUFFER_MAX_SIZE, 0, (struct sockaddr*)&addrCli, &addrlen);
            printf("Cli:>%s\n", recvbuf);
            printf("Ser:>");
            scanf("%s", sendbuf);
            sendto(sockSer, sendbuf, strlen(sendbuf)+1, 0, (struct sockaddr*)&addrCli, addrlen);
        }
        close(sockSer);
    
        return 0;
    }

客户端代码：cli.c

#include "utili.h"
    
    int main()
    {
        int sockCli = socket(AF_INET, SOCK_DGRAM, 0);
        if(sockCli == -1)
        {
            perror("socket.");
            exit(1);
        }
    
        struct sockaddr_in addrSer;
        addrSer.sin_family = AF_INET;
        addrSer.sin_port = htons(7070);
        addrSer.sin_addr.s_addr = inet_addr("127.0.0.1");
    
        socklen_t addrlen = sizeof(struct sockaddr);
        while(1)
        {
            printf("Cli:>");
            scanf("%s", sendbuf);
            sendto(sockCli, sendbuf, strlen(sendbuf)+1, 0, (struct sockaddr*)&addrSer, addrlen);
            recvfrom(sockCli, recvbuf, BUFFER_MAX_SIZE, 0, (struct sockaddr*)&addrSer, &addrlen);
            printf("Ser:>%s\n",recvbuf);
        }
    
        close(sockCli);
        return 0;
    }

Makefile代码：

all:ser cli
    
    ser:ser.c
    	gcc -o ser ser.c
    cli:cli.c
    	gcc -o cli cli.c
    
    .PHONY:clean
    clean:
    	rm ser cli

4、make：生成文件ser和cli

![20190813153833590.png][]

5、分别执行ser和cli进行通信(借助putty)：

服务器：

![20190813153916623.png][]

客户端：

![20190813153938295.png][]

[UDP]: https://blog.csdn.net/qq_26079093/article/details/99318145
[20190813153833590.png]: /images/20211015/c3895057796d402f8cd6946b69a3b7fd.png
[20190813153916623.png]: /images/20211015/a900186ea1a04c4496a0c479b49731fc.png
[20190813153938295.png]: /images/20211015/e2e5b8d2b5c94b4690e78533657874ee.png