client_udp.c

#include "common.h"

int main(int argc, char * argv[])
{
  FILE *fp;
  struct hostent *hp;
  struct sockaddr_in sin;
  char *host;
  char *fname;
  char buf[MAX_LINE];
  int s;
  int slen;

  if (argc==3) {
    host = argv[1];
    fname= argv[2];
  }
  else {
    fprintf(stderr, "Usage: ./client_udp host filename\n");
    exit(1);
  }
  /* translate host name into peer’s IP address */
  if (!hp) {
    fprintf(stderr, "Unknown host: %s\n", host);
    exit(1);
  }

  fp = fopen(fname, "r");
  if (fp==NULL){
    fprintf(stderr, "Can't open file: %s\n", fname);
    exit(1);
  }

  hp = gethostbyname(host);
  /* build address data structure */
  bzero((char *)&sin, sizeof(sin));
  sin.sin_family = AF_INET;
  bcopy(hp->h_addr, (char *)&sin.sin_addr, hp->h_length);
  sin.sin_port = htons(SERVER_PORT);

  /* active open */
  if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
    perror("Socket");
    exit(1);
  }

  socklen_t sock_len= sizeof sin;

  printf("Sending file\r\n");
  SendFile(fp,s,&sin);
  
  *buf = 0x02;  
    if(sendto(s, buf, 1, 0, (struct sockaddr *)&sin, sock_len)<0){
    perror("SendTo Error\n");
    exit(1);
  }
  fclose(fp);
}