server.c

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>



int main()
{
  int sockfd,rec_sock,sockfd1, len,i;
  struct sockaddr_in addr, recaddr;
   char buf[100],buf1[100];
   int port;
   FILE* fichier = NULL;



  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    perror(": Can't get socket");
    exit(1);
  }

  addr.sin_addr.s_addr = INADDR_ANY;
  addr.sin_family = AF_INET;
  addr.sin_port = htons(4450);

  if (bind(sockfd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
    perror(": bind");
    exit(1);
  }

  printf("ip = %s, port = %d\n", inet_ntoa(addr.sin_addr), addr.sin_port);

  if (listen(sockfd, 5) < 0) {
    perror(": bind");
    exit(1);
  }


   while (1)
{
       rec_sock = accept(sockfd, (struct sockaddr *)(&recaddr), &len);

  if (rec_sock < 0) {
    perror(": accept");
    exit(1);
  }

  /* print the remote socket information */

  printf("remote machine = %s, port = %x, %x.\n", inet_ntoa(recaddr.sin_addr), recaddr.sin_port, ntohs(recaddr.sin_port));



  write(rec_sock, "connecter", 20);

  for (i=0; i<100; i++)
  buf[i] = '\0';
  read(rec_sock, buf, 99);
  printf("port aleatoire : %s\n", buf);

  // put client info in a txt file

  fichier = fopen("tmp.txt", "w");
  if (fichier != NULL)
    {
    fprintf(fichier,"Remote machine ip = %s  Port = %s \n",inet_ntoa(recaddr.sin_addr),buf);
    fclose(fichier);
    }
    printf("\n \n")

    port=atoi(buf);

  recaddr.sin_family = AF_INET;
  recaddr.sin_port = htons(port);

  if ((sockfd1 = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    perror(": Can't get socket");
    exit(1);
  }

  if (connect(sockfd1, (struct sockaddr *)&recaddr, sizeof(recaddr)) < 0) {
    printconnerror();
    perror(": connect");
    exit(1);
  }

  for (i=0; i<100; i++)
  buf[i] = '\0';
  read(sockfd, buf, 99);
  printf("Chaine = %s\n", buf);
  printf("Commande a executer chez le client \n");
  scanf("%s",&buf1);
  write(sockfd1,buf1,20);


}

  sleep(20);
  exit(1);

}