Linux Programming Example-Simple multi-process server

The main use of fork in advance to create a number of processes, concurrent processing of multiple client connections, return the current system time. The specific code is as follows:

Server.c

# include <sys/types.h># include <sys/socket.h># include <netinet/in.h># include <time.h># Include <string.h># include <stdio.h># include <signal.h># include <errno.h># include < unistd.h> #define Bufflen 1024#define server_port 3333#define BACKLOG 5#define pidnum 3static void handle_connect (int s    ERV_FD) {int client_fd;    struct sockaddr_in client_addr;        int len=sizeof (CLIENT_ADDR); while (1) {if (Client_fd=accept (serv_fd, (struct sockaddr*) &client_addr,&len) <0) {PE        Rror ("accept");        Exit (errno);           } printf ("Accept done,the process id=%d\n", getpid ());        time_t now;        Char buff[bufflen]={0};        int n=0;        memset (Buff,0,bufflen);        N=RECV (client_fd,buff,bufflen,0);                        if (n>0&&!strncmp (Buff, "time", 4)) {memset (Buff,0,bufflen);            Now=time (NULL); sprintf (Buff, "%24s\r\n", CTime (&noW));        Send (Client_fd,buff,strlen (buff), 0);    } close (CLIENT_FD); }}void sig_int (int num) {exit (1);}    int main (int argc, char* argv[]) {int servfd;    unsigned int lisnum=3;    struct sockaddr_in serv_addr;    Signal (Sigint,sig_int);    Servfd=socket (af_inet,sock_stream,0);    memset (&serv_addr,0,sizeof (SERV_ADDR));    Serv_addr.sin_family=af_inet;    Serv_addr.sin_addr.s_addr=htonl (Inaddr_any);    Serv_addr.sin_port=htons (Server_port);    int Err=bind (servfd, (struct sockaddr*) &serv_addr,sizeof (SERV_ADDR));        if (listen (servfd,lisnum) = =-1) {perror ("listen");        Exit (errno);    }else printf ("The server is listening!\n");    pid_t Pid[pidnum];    int i=0;        for (i=0;i<pidnum;i++) {pid[i]=fork ();        if (pid[i]==0) {handle_connect (SERVFD);    }} while (1);    Close (SERVFD); return 0;}

client.c

#include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <time.h># include<string.h> #include <stdio.h> #include <errno.h> #define Bufflen 1024#define Server_port    3333int Main (int argc,char*argv[]) {int clientfd;    struct sockaddr_in serv_addr;    time_t now;    Char buff[bufflen]={0};    int n=0,err;    Clientfd=socket (af_inet,sock_stream,0);    memset (&serv_addr,0,sizeof (SERV_ADDR));    Serv_addr.sin_family=af_inet;    Serv_addr.sin_addr.s_addr=htonl (Inaddr_any);    Serv_addr.sin_port=htons (Server_port);        if ((Err=connect (CLIENTFD, (struct sockaddr*) &serv_addr,sizeof (SERV_ADDR))) (<0) {perror ("connect");    Exit (errno); } printf ("Connected done!!    \ n ");    memset (Buff,0,bufflen);    strcpy (Buff, "time");    Send (Clientfd,buff,strlen (buff), 0);    memset (Buff,0,bufflen);    N=RECV (clientfd,buff,bufflen,0);    if (n>0) {printf ("time:%s\n", buff);    } close (CLIENTFD); return 0;}