/* gcc socket_server.c -lnsl -lsocket -o socket_server */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
main(argc,argv) int argc; char **argv;
{
  int sock,fd,len,n;
  struct sockaddr_in server;
  char buff[1024];

  /* Create a socket */
  sock=socket(AF_INET, SOCK_STREAM, 0);
  if (sock < 0) { perror("opening socket"); exit(1);}

  /* Set server address family */
  server.sin_family=AF_INET;
  /* Set the requesting client's address to INADDRR_ANY, no limitations */
  server.sin_addr.s_addr=INADDR_ANY;
  /* Port 6500 */
  server.sin_port=ntohs(6500);

  len = sizeof(server);
  /* bind a server to a socket */
  if (bind(sock,(struct sockaddr *) &server, len) < 0) {
    perror("binding"); exit(1); }

  /* If systems decides the ports to be used then getsockname can be used */
  if (getsockname(sock,(struct sockaddr *) &server, &len) < 0) {
    perror("getting name"); exit(1); }
  /* Print port number and tell it to a client */
  /* ntohs()  function converts the short integer netshort */
  /* from network byte order to host byte order. */
  printf("Client can send now the data to port #%d\n",
      ntohs(server.sin_port));

  /* Start listening a socket, create a queue of 5 requests */
  listen(sock,5);
  do{
    /* Accept a request, and create socket for it */
       fd=accept(sock,(struct sockaddr *)0,(int *)0);
       if (fd == -1) {perror("accept fd");exit(1);}
       else do {
	   /* read a socket, n is number of bytes succesfully read */
           n=read(fd,buff,1024);
           if (n < 0) perror("read socket");
           else if (n==0) printf("EOF received.\n");
           else printf("> %s\n",buff);
       }while(n > 0);
       /* close a socket and wait for a new request */
       close(fd);
  }while(1);
}