server.c

   1 /* A simple server in the internet domain using TCP
   2    The port number is passed as an argument */
   3 #include <stdio.h>
   4 #include <sys/types.h>
   5 #include <sys/socket.h>
   6 #include <netinet/in.h>
   7
   8 void error(char *msg)
   9 {
  10     perror(msg);
  11     exit(1);
  12 }
  13
  14 int main(int argc, char *argv[])
  15 {
  16      int sockfd, newsockfd, portno, clilen;
  17      char buffer[256];
  18      struct sockaddr_in serv_addr, cli_addr;
  19      int n;
  20      portno = 4949;
  21      serv_addr.sin_family = AF_INET;
  22      serv_addr.sin_addr.s_addr = INADDR_ANY;
  23      serv_addr.sin_port = htons(portno);
  24
  25      sockfd = socket(AF_INET, SOCK_STREAM, 0);
  26
  27      if (sockfd < 0)
  28         error("ERROR opening socket");
  29
  30      bzero((char *) &serv_addr, sizeof(serv_addr));
  31
  32      if (bind(sockfd, (struct sockaddr *) &serv_addr,
  33               sizeof(serv_addr)) < 0)
  34               error("ERROR on binding");
  35
  36      listen(sockfd,5);
  37      clilen = sizeof(cli_addr);
  38
  39      newsockfd = accept(sockfd,
  40                  (struct sockaddr *) &cli_addr,
  41                  &clilen);
  42
  43      if (newsockfd < 0)
  44           error("ERROR on accept");
  45
  46      bzero(buffer,256);
  47      n = read(newsockfd,buffer,255);
  48
  49      if (n < 0) error("ERROR reading from socket");
  50
  51      printf("Here is the message: %s\n",buffer);
  52
  53      n = write(newsockfd,"I got your message",18);
  54
  55      if (n < 0) error("ERROR writing to socket");
  56
  57      return 0;
  58 }