socket中udp的简单实现

服务器源代码：

#include<stdio.h>
#include<unistd.h>
#include<string.h>
#include<sys/socket.h>
#include<netinet/in.h>

int main()
{
    int sockSer = socket(AF_INET, SOCK_DGRAM, 0);
    if(sockSer == -1)
    {
        perror("socket");
        return -1;
    }

    struct sockaddr_in addrSer, addrCli;
    addrSer.sin_family = AF_INET;
    addrSer.sin_port = htons(7070);
    addrSer.sin_addr.s_addr = inet_addr("127.0.0.1");//绑定ip地址，此处采用本地环回地址

    socklen_t addrlen = sizeof(struct sockaddr);
    bind(sockSer, (struct sockaddr*)&addrSer, addrlen);

    char sendbuf[256];
    char recvbuf[256];
    while(1)
    {
        recvfrom(sockSer, recvbuf, 256, 0, (struct sockaddr*)&addrCli, &addrlen);
        printf("Cli[%d]:> %s\n",ntohs(addrCli.sin_port), recvbuf);
        printf("Ser:>");
        scanf("%s",sendbuf);
        sendto(sockSer, sendbuf, strlen(sendbuf)+1, 0, (struct sockaddr*)&addrCli, addrlen);
    }

    close(sockSer);
    return 0;
}

客户端的源代码

#include<stdio.h>
#include<unistd.h>
#include<string.h>
#include<sys/socket.h>
#include<netinet/in.h>

int main()
{
    int sockCli = socket(AF_INET, SOCK_DGRAM, 0);
    if(sockCli == -1)
    {
        perror("socket");
        return -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"); //绑定ip地址，此处采用本地环回地址

    socklen_t addrlen = sizeof(struct sockaddr);

    char sendbuf[256];
    char recvbuf[256];
    while(1)
    {
        printf("Cli:>");
        scanf("%s",sendbuf);
        sendto(sockCli, sendbuf, strlen(sendbuf)+1, 0, (struct sockaddr*)&addrSer, addrlen);
        recvfrom(sockCli, recvbuf, 256, 0, (struct sockaddr*)&addrSer, &addrlen);
        printf("Ser:> %s\n", recvbuf);
    }

    close(sockCli);
    return 0;
}

总结：上述代码UDP的实现通信的优点是可以有多个客户端同时和服务器进行通信，缺点是服务器和客户端通信时，只能采用一问一答的方式，同时缺少退出机制。