Linux 基于UDP（C/S）双向通信

源码如下

“client.c”

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
int main(int argc,char *argv[])
{
    unsigned short port = 8888;
    if(argc>1)//服务器端口号
    {
        port=atoi(argv[1]);
        puts(argv[1]);
        printf("%d\n",port);
    }
    int sfd;
    sfd=socket(AF_INET,SOCK_DGRAM,0);
    if(sfd<0)
    {
        perror("socket");
        exit(-1);
    }
    struct sockaddr_in dest_addr;
    memset(&dest_addr,0,sizeof(dest_addr));
    dest_addr.sin_family=inet_addr("0.0.0.0");
    dest_addr.sin_family=AF_INET;
    dest_addr.sin_port=htons(port);
    printf("%d\n",dest_addr.sin_port);

    while(1)
    {
        printf("发送数据\n");
        char send_buf[512]="";
        fgets(send_buf,sizeof(send_buf),stdin);
        send_buf[strlen(send_buf)-1]='\0';
        sendto(sfd,send_buf,strlen(send_buf),0,(struct sockaddr *)&dest_addr,sizeof(dest_addr));

        printf("开始接受数据\n");
        int rec_len;
        char recv_buf[512]="";
        char cli_ip[INET_ADDRSTRLEN]="";
        struct sockaddr_in sever_addr;
        socklen_t sever_len = sizeof(sever_addr);

        rec_len=recvfrom(sfd,recv_buf,sizeof(recv_buf),0,(struct sockaddr *)&sever_addr,&sever_len);
        printf("rec_len is %d\n",rec_len);
        inet_ntop(AF_INET,&sever_addr.sin_addr,cli_ip,INET_ADDRSTRLEN);
        printf("ip:%s,port:%d\n",cli_ip,ntohs(sever_addr.sin_port));
        printf("data(%d):%s\n",rec_len,recv_buf);


    }

    close(sfd);
    return 0;
}


"server.c"

#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <arpa/inet.h>
#include<string.h>
int main()
{
    int sfd;
    unsigned short port=8888;//监听端口
    sfd=socket(AF_INET,SOCK_DGRAM,0);
    struct sockaddr_in addr;
    memset(&addr,0,sizeof(addr));
    addr.sin_addr.s_addr=htons(INADDR_ANY);//本机地址
    addr.sin_family=AF_INET;
    addr.sin_port=htons(port);
    printf("Binding server to port is %d\n",port);
    int log;
    log=bind(sfd,(const struct sockaddr *)&addr,sizeof(addr));
    if(log!=0)
    {
        perror("bind");
        close(sfd);
        exit(-1);
    }
    printf("seceive data !\n");
    while(1)
    {
        int rec_len;
        int send;
        char buf[1024];
        char cli_ip[INET_ADDRSTRLEN]="";
        struct sockaddr_in client_addr;
        socklen_t cliaddr_len=sizeof(client_addr);
        rec_len=recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr *)&client_addr,&cliaddr_len);
        printf("reclen is %d\n",rec_len);
        inet_ntop(AF_INET,&client_addr.sin_addr,cli_ip,INET_ADDRSTRLEN);
        printf("ip:%s,port:%d\n",cli_ip,ntohs(client_addr.sin_port));
        printf("data(%d):%s\n",rec_len,buf);
        printf("发送数据\n");
        char send_buf[524]="";
        printf("server send\n");
        fgets(send_buf,sizeof(send_buf),stdin);
        printf("this is send buf\n");
        send_buf[strlen(send_buf)-1]='\0';
        send=sendto(sfd,send_buf,strlen(send_buf),0,(struct sockaddr *)&client_addr,sizeof(client_addr));
        printf("%d\n",send);
    }
    close(sfd);
    return 0;
}