/* sockclnt.c*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h> /*for struct sockaddr_in*/
#include <signal.h>

#define SVR_IP      "12.12.12.221"
#define SVR_PORT    1234
#define BUFSIZE        255

int sockfd  = 0;
void mysigint(int sig)
{
    printf("close fd = %d\n",sockfd);
    close(sockfd);

}

int main()
{
    signal(5,mysigint);
    int ret     = 0;
    struct sockaddr_in svr_addr;
    memset(&svr_addr, 0, sizeof(struct sockaddr_in));

char * msg = "'path:/home/dongshen/media_file/b_1.ts'";

// create client socket fd
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd == -1) {
        perror("socket failed");
        exit(1);
    }

// connet to server
    svr_addr.sin_family         = AF_INET;                 
    svr_addr.sin_port           = htons(SVR_PORT);          
    svr_addr.sin_addr.s_addr    = inet_addr(SVR_IP);
 
printf("before connect\n");
    ret = connect(sockfd, (struct sockaddr *)&svr_addr, sizeof(struct sockaddr_in));
    if (ret == -1) {
        perror("connect failediiiii");
        exit(1);
    }
printf("after connect\n");
    int i = 0;
    for (i = 0; i < 500; i++)
    {
        char * msg = "hello server....";
        printf("client send msg: %s\n", msg);
        if((send(sockfd, msg,    strlen(msg), 0))<0)
        {
            perror("send()");
        }

char recv_buf[BUFSIZE] = {0};
        int recv_len = recv(sockfd, recv_buf, sizeof(recv_buf), 0);
        printf("client recv msg: %s%d\n", recv_buf, recv_len);

sleep(100);
    }   
    close(sockfd);

}

服务端

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h> /* for struct sockaddr_in*/
#include <sys/errno.h>
#include <signal.h>

#define SVR_IP   "12.12.12.221"
#define SVR_PORT  1234
#define BACKLOG   10

#define MAX_BUF_LEN 1024

int connfd      = 0;
void mysigint(int sig)
{
        printf("sigint   i will close connfd = %d\n",connfd);
        close(connfd);
}

void chld_handle(int sig)
{
    pid_t   pid;
    int     stat;

while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
    {
        printf("child %d terminated\n", pid);
    }
    return;    
}

int main()
{
    
        struct sigaction act;
    act.sa_handler = chld_handle;
    sigemptyset(&act.sa_mask);
    act.sa_flags = SA_RESTART;

sigaction(SIGCHLD, &act, 0);
    int listenfd    = 0;
    int ret         = 0;
    struct sockaddr_in svr_addr, cli_addr;
    memset(&svr_addr, 0, sizeof(struct sockaddr_in));
    memset(&cli_addr, 0, sizeof(struct sockaddr_in));
 
    // create listen socket fd
    listenfd = socket(AF_INET, SOCK_STREAM, 0);        
        if (listenfd == -1) {
                perror("socket failed");
        exit(1);
        }

// bind svr ip and port
        svr_addr.sin_family = AF_INET;                
        svr_addr.sin_port = htons(SVR_PORT);            
        svr_addr.sin_addr.s_addr = inet_addr(SVR_IP);
        ret = bind(listenfd, (struct sockaddr*)&svr_addr, sizeof(struct sockaddr));
        if (ret == -1) {
                perror("binad failed");
                exit(1);
        }

// listen client
        ret = listen(listenfd, BACKLOG);
        if (ret == -1) {
                perror("listen failed");
                exit(1);
        }

printf("server is on...\n");

while(1)
    {
        int sin_size = sizeof(struct sockaddr_in);
        if((connfd = accept(listenfd, (struct sockaddr *)&cli_addr, &sin_size)) < 0)
        {
            perror("accept failed");
            if (errno == EINTR)
            {
                perror("child process cause it\n");
                continue;
            }
            else
            {
                break;
            }
        }

pid_t child_pid = fork();
        if (0 == child_pid) // this is child process
        {
            close(listenfd);
            printf("one socket(%d) client come\n", connfd);
           
    signal(SIGINT,mysigint);

char recv_buf[MAX_BUF_LEN] = {0};
            int recv_len = 0;
            while((recv_len = recv(connfd, recv_buf, sizeof(recv_buf), 0)) > 0)
            {
                printf("svr %d recv %s recv_len %d\n", connfd, recv_buf, recv_len);
                ret = send(connfd, recv_buf, strlen(recv_buf), 0);
                if (ret < 0)
                {
                    perror("send failed");
                    exit(1);
                }
                memset(recv_buf, 0, sizeof(recv_buf));
            }

if (recv_len < 0)
            {
                perror("recv failed");
                exit(1);
            }
            printf("one socket(%d) client go\n", connfd);
            close(connfd);
            exit(0);
        }

close(connfd);
    }
    close(listenfd);
        return 0;
}