bfishchat_client

gistfile1.c

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h> /* memset() */
#include <sys/time.h> /* select() */

#define CHARPERLINE     512
#define REMOTE_SERVER_PORT 1500
#define MAX_MSG 100

void senddata (char tosend[1024], char destaddr[21]) {
  int sd, rc;
  struct sockaddr_in cliAddr, remoteServAddr;
  struct hostent *h;

  h = gethostbyname(destaddr);
  if(h==NULL) {
    printf("unknown host '%s' \n", destaddr);
    exit(1);
  }
  remoteServAddr.sin_family = h->h_addrtype;
  memcpy((char *) &remoteServAddr.sin_addr.s_addr,
         h->h_addr_list[0], h->h_length);
  remoteServAddr.sin_port = htons(REMOTE_SERVER_PORT);
  /* socket creation */
  sd = socket(AF_INET,SOCK_DGRAM,0);
  if(sd<0) {
    printf("cannot open socket \n");
    exit(1);
  }
  /* bind any port */
  cliAddr.sin_family = AF_INET;
  cliAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  cliAddr.sin_port = htons(0);

  rc = bind(sd, (struct sockaddr *) &cliAddr, sizeof(cliAddr));
  if(rc<0) {
    printf("cannot bind port\n");
    exit(1);
  }
  rc = sendto(sd, tosend, strlen(tosend)+1, 0,
             (struct sockaddr *) &remoteServAddr,
             sizeof(remoteServAddr));
}

int main (int argc, char *argv[]) {
  char text[CHARPERLINE];
  char key[81], tmpkey[81];
  char sendbuf[1024];

  /* check command line args */
  if(argc<2) {
    printf("\nusage : %s <peer> || <peer2> \n", argv[0]);
    exit(1);
  }

  if(argc>3) {
    printf("\nusage : %s <peer> || <peer2> \n", argv[0]);
    exit(1);
  }
  
  printf("\nPlease input the seed for the desired key ==> ");
  fgets(key,81,stdin);
  printf("\nPlease re-input the seed for the desired key ==> ");
  fgets(tmpkey,81,stdin);

  if (strcmp(key,tmpkey) != 0) {
	printf("\nThose keys do not match...\nexiting.");
	exit(1);
  }

  printf("\nOk, listening for input...type \"/quit\" to exit\n"); 
   

for (;;) {
    FILE *fp=stdin;
    fd_set readset;
    FD_ZERO(&readset);
    FD_SET(0, &readset); //FDSET IS VERY NECESSARY, otherwise the test cases below dont work!!!
    /* Check for data on stdin */
    if (FD_ISSET(fileno(fp), &readset)) {
      memset(text, 0, sizeof(text));
      if (!read(0, text, sizeof(text) - 1)) {
        printf ("\n Exiting...\n");
        return 0;
      }
      else {  
       //---------CONDITIONAL BLOCK FOR COMMANDS! 
        if(text[0] == '/') {
          if(!strncmp(text,"/quit", 5)) {
            printf("\n*** Exiting... ***\n");
            return 0;
          }
        }
        //encrypt data text[] --> sendbuf[];
	strncpy(sendbuf,encrypt_string(key,text),sizeof(sendbuf)-1);
        //new data send routine
   	senddata(sendbuf, argv[1]);  
	if (argc==3) { //IF ANOTHER IP WAS Specified, then send to it.
		senddata(sendbuf, argv[2]);
	}	 
	}
    } 
  }
  return 0;
}