gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#define BUFFER_SIZE 128

const int TAILLE_FILE = 3;

/** Fonction permettant l'initialisation d'une struct du type sockaddr */
void init_sockaddr(struct sockaddr_in *name, char* hostname, int port)
{
  struct hostent *hostinfo;

  name->sin_family = AF_INET;
  name->sin_port = htons(port);

  hostinfo = gethostbyname(hostname);

  if(hostinfo == NULL)
  {
    fprintf(stderr,"Erreur, l'host %s est inconnu", hostname);
    exit(1);
  }

  name->sin_addr = *(struct in_addr *) hostinfo->h_addr_list[0];
}

int bindSocket(char* hostname, int port, int fd)
{
  struct sockaddr_in addr;

  /* Initialisation de la structure */
  init_sockaddr(&addr, hostname, port);

  if(bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1 )
    return -1;

  return 0;
}

int listenSocket(unsigned int taille, int fd)
{
  if(listen(fd , taille) == -1)
    return -1;

  return 0;
}

int acceptSocket(int fd)
{
  int fd_socket;

  if( (fd_socket = accept(fd, NULL, NULL)) == -1)
    perror("accept"), exit(1);

  return fd_socket;
}


void tcp(char* hostname,int port)
{
  char buffer[BUFFER_SIZE];
  int numRead;
  int clientFD;
  int sockService;

  /* Mise en place de la socket de service. */
  if((sockService = socket(PF_INET,SOCK_STREAM, 0)) == -1)
    perror("socket Service"),exit(1);

  if(bindSocket(hostname,port,sockService))
    perror("bindSocket"),exit(1);

  if(listenSocket(TAILLE_FILE, sockService))
    perror("listenSocket"), exit(1);

  /* On attend un client. */
  clientFD = acceptSocket(sockService);

  /* Lecture des données envoyées sur la socket, puis écriture de celle-ci sur
   * stdout.
   */
  while((numRead = read(clientFD, buffer, BUFFER_SIZE - 1)) > 0)
  {
    buffer[numRead] = 0;
    puts(buffer);
  }

  close(sockService);
}

void usage(char* name)
{
  fprintf(stderr,"Usage: %s [port] \n",name);
  exit(1);
}

int main(int argc,char** argv)
{
  int port;

  if(argc != 3)
    usage("name");

  if(sscanf(argv[2], "%d" ,&port) != 1)
    usage(argv[0]);

  tcp(argv[1], port);

  return 0;
}