linux系统中 c语言实现tcp Server并发接收

linux系统中 c语言实现tcp Server并发接收

#include "stdio.h"
#include "stdlib.h"
#include "unistd.h"
#include "signal.h"
#include "wait.h"
#include "errno.h"
#include "sys/socket.h"
#include "netinet/in.h"
#include "arpa/inet.h"

void sigchld(int signum)
{
    for(;;)
    {
        pid_t  pid =  waitpid(-1,NULL,WNOHANG);
        if(pid == -1)
        {
            if(errno != ECHILD)
            {
                perror("waitpid");
                exit(-1);
            }
            printf("exit");
            break;
        }

        if(pid)
        {
            printf("server pid;%d",pid);
        }
        else{
                    printf("服务器："
                     "暂时没有子进程退出n");
                     break;
        }
    }
}

int client(int connfd)
{
    for(;;)
    {
                printf("%d：接收请求n", getpid());

                char buf[1024];

                ssize_t rb  = recv(connfd,buf,sizeof(buf),0);
	
                if (rb == -1)
                {
                      perror("recv");
                      return -1;
                }
			  
                if (rb == 0)
                {
                             printf("%d：客户机已关闭n",
                             getpid());
                              break;
                }
                  printf("%d：发送响应n", getpid());
            
                 send(connfd,buf,rb,0);
    }
    return 0;
}

int main(int  argc, char * argv[])
{
    if(argc < 2)
    {
                fprintf(stderr, "用法：%s <端口号>n",  argv[0]);
                return -1;
    }

    //子进程退出信号
    if(signal(SIGCHLD,sigchld) == SIG_ERR)
    {
        perror("signal");
        return -1;
    }

    printf("服务器：创建网络套接字n");

    int  sockfd = socket(PF_INET,SOCK_STREAM,0);

    if (sockfd == -1) {
        perror("socket");
        return -1;
    }

     printf("服务器：准备地址并绑定n");
     struct sockaddr_in addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(atoi(argv[1]));

    if(bind(sockfd,(struct sockaddr *)&addr,sizeof(addr) )== -1)
    {
        perror("bind");
        return -1;
    }

    //服务器：侦听套接字
    if(listen(sockfd,1024) == -1)
    {
        perror("listen");
        return -1;
    }

    for (;;)
    {
            struct  sockaddr_in addrcli = {};
            socklen_t addrlen = sizeof(addrcli);
            int connfd = accept(sockfd,(struct sockaddr *)&addrcli,&addrlen);

            if(connfd == -1)
            {
                perror("accept");
                return -1;
            }
            
             printf("服务器：客户机%s:%un",inet_ntoa(addrcli.sin_addr),ntohs(addrcli.sin_port));

             pid_t pid = fork();
            if (pid == -1) 
            {
                perror("fork");
                return -1;
            }

            if(pid == 0)
            {
                if(close(sockfd) == -1)
                {
                    perror("close");
                    return -1;
                }
                client(connfd);
                close(connfd);
                printf("%d：完成n", getpid());
                return 0;
            }
        
        close(connfd);
        return 0;
    }
}