C/S Mode programming _c language under Linux

The

is known by the title, this article is mainly about how to implement a C/S mode of the program with the language
Main function: Time loopback. The
client makes a request, server response time, and returns the server time to synchronize with the client.
Nonsense not much said, the following directly posted source code. The
code is as follows:

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <e rrno.h> #include <time.h> #include <sys/types.h> #include <sys/socket.h> #include <arpa/inet 
 
.h> void client_process (int connfd); 
  int main (int argc, char *argv[]) {int ret; 
  int LISTENFD; 
  int CONNFD; 
  struct sockaddr_in srvaddr; 
  struct sockaddr_in cliaddr; 
 
  Socklen_t Addrlen; 
  LISTENFD = socket (af_inet, sock_stream, 0); 
    if (LISTENFD = = 1) {perror ("socket"); 
  Exit (Exit_failure); 
  } srvaddr.sin_family = Af_inet; 
  Srvaddr.sin_port = htons (8888); 
  SRVADDR.SIN_ADDR.S_ADDR = htonl (Inaddr_any); 
  ret = bind (LISTENFD, (struct sockaddr *) &srvaddr, sizeof (SRVADDR)); 
    if (ret = = 1) {perror ("bind"); 
  Exit (Exit_failure); 
  RET = Listen (LISTENFD, 5); 
    if (ret = = 1) {perror ("listen"); 
  Exit (Exit_failure); while (1) {memset (&cliaddr, 0, sizeOf (CLIADDR)); 
    Addrlen = sizeof (CLIADDR); 
    CONNFD = Accept (LISTENFD, (struct sockaddr *) &cliaddr, &addrlen); 
      if (CONNFD!=-1) {printf ("A new client is comming\n"); 
      Client_process (CONNFD); 
      printf ("disconnect\n"); 
    Close (CONNFD); 
  else Perror ("accept"); 
Close (LISTENFD); 
  } void client_process (int connfd) {int ret; 
 
  Char buf[4096]; 
    while (1) {memset (buf, 0, sizeof (BUF)); 
    strcpy (buf, "Kevin@timeserver $"); 
    ret = Write (CONNFD, buf, strlen (BUF) + 1); 
      if (ret = = 1) {perror ("write"); 
    Return 
    } memset (buf, 0, sizeof (BUF)); 
    ret = Read (CONNFD, buf, sizeof (BUF)); 
 
        if (Ret > 0) {if (strcmp (buf, "time\r\n") = = 0) {time_t t; 
        memset (buf, 0, sizeof (BUF)); 
        strcpy (buf, "Kevin@timeserver $"); 
        ret = Write (CONNFD, buf, strlen (BUF) + 1); 
          if (ret = = 1) {perror ("write"); 
   Return     } time (&t); 
 
        strcpy (buf, CTime (&t)); 
        ret = Write (CONNFD, buf, strlen (BUF) + 1); 
          if (ret = = 1) {perror ("write"); 
        Return 
      }} else if (ret = 1) {perror ("read"); 
    Return 
  else return; 
 } 
}

Main process
1. Set up source program, input source code.
2. Open a terminal, compile and run the program. Compiler: GCC cs.c Run Program:./a.out
3. Open a new terminal, input: telnet localhost 8888
The main window effects are as follows:

4. Enter in child window: Time
The child window appears as follows:

5. Close the child window, the main window shows: The connection is disconnected.
The effect is as follows:

OK, the program is about here, I hope you like it, for everyone's learning help.