Client-Server Data Read Problem

Hi All,

I'm trying to reading in data from a file and send that data to a server, but I'm getting a data read error. Here's the following error:

$ gcc *Client* -o *Client*
udpClient.c: In function `main':
udpClient.c:76: warning: comparison between pointer and integer
Undefined first referenced
symbol in file
socket /var/tmp/cc05IzIT1.o
gethostbyname /var/tmp/cc05IzIT1.o
bind /var/tmp/cc05IzIT1.o
sendto /var/tmp/cc05IzIT1.o
inet_ntoa /var/tmp/cc05IzIT1.o
ld: fatal: Symbol referencing errors. No output written to udpClient.c
$

No output written to the client file.

Here's the code for the client file. It's a little lengthy. Any help would be appreciated:

Code:

#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 REMOTE_SERVER_PORT 4500
#define MAX_MSG 100

// ----------------------------------
// --------- MAIN -------------------
// ----------------------------------

int main (int argc, char *argv[])
{
   int sd, rc, i;
   struct sockaddr_in cliAddr, remoteServAddr;
   struct hostent *h;
   
    // Get Data
    FILE *data;
    char c;
	
    data = fopen("data.txt", "t");

   // check command line arguments
   if (argc < 3)
   {
      printf("usage : %s <server> <data1> ... <dataN> \n", argv[0]);
      exit(1);
   }

   // get server IP address (no check if input is IP address or DNS name)
   h = gethostbyname(argv[1]);
   if (h == NULL)
   {
      printf("%s: unkown host '%s' \n", argv[0], argv[1]);
      exit(1);
   }

   printf("%s: sending data to '%s' (IP: %s) \n", argv[0], h->h_name, inet_ntoa(*(struct in_addr *)h->h_addr_list[0]));

  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("%s: cannot open socket \n", argv[0]);
      exit(1);
  }

  // bind any port
  cliAddr.sin_family = AF_INET;
  cliAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  cliAddr.sin_port = htons(4502);

  rc = bind(sd, (struct sockaddr *) &cliAddr, sizeof(cliAddr));
  if (rc < 0)
  {
      printf("%s: cannot bind port \n", argv[0]);
      exit(1);
  }
  
  // send data
  for (i = 2; 1 < argv[i]; i++)
  {
     if (data == NULL) printf("File doesn't exist\n");
   	 else {
      do {
         c = getc(data);    /* get one character from the file */
         putchar(c);         /* display it on the monitor       */
	     rc = sendto(sd, argv[i], strlen(argv[i]) + 1, 0, (struct sockaddr *) &remoteServAddr, sizeof(remoteServAddr));		 
      } while (c != EOF);    /* repeat until EOF (end of file)  */
   }	  
   
      if (rc < 0)
      {
         printf("%s: cannot send data \n", argv[0]);
         close(sd);
         exit(1);
      }

  }

  return 1;

}

Thanks

mind telling me which one is line 76?

Here's line 76:

for (i = 2; 1 < argv[i]; i++)

Thank you for the advice. I entered what you suggested and got the following:

$ gcc *Client* -o Client
udpClient.c: In function `main':
udpClient.c:87: warning: comparison between pointer and integer
udpClient.c: At top level:
udpClient.c:101: parse error before `return'
$

Still can't get this file to compile

OK, I fixed the argument, it was a typeo.

Still getting one error in which I can't figure out.


$ gcc *Client* -o Client
udpClient.c:101: parse error before `return'

Any ideas?

Thanks for helping.

Wow -- another typeo problem. Well, all typeos fix. Now when I compile I get this.

$ gcc *Client* -o Client
Undefined first referenced
symbol in file
socket /var/tmp/ccZPnO__1.o
gethostbyname /var/tmp/ccZPnO__1.o
bind /var/tmp/ccZPnO__1.o
sendto /var/tmp/ccZPnO__1.o
inet_ntoa /var/tmp/ccZPnO__1.o
ld: fatal: Symbol referencing errors. No output written to Client
$

Here's the revised code:

Code:

/* fpont 12/99  */
/* pont.net     */
/* udpClient.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 REMOTE_SERVER_PORT 4500
#define MAX_MSG 100

// ----------------------------------
// --------- MAIN -------------------
// ----------------------------------

int main (int argc, char *argv[])
{
   int sd, rc, i;
   struct sockaddr_in cliAddr, remoteServAddr;
   struct hostent *h;
   
    // Get Data
	FILE *fp1;
	char oneword[100], filename[25];
	char *c;

   	printf("Enter filename -> ");
	scanf("%s", filename);            /* read the desired filename  */
   	fp1 = fopen(filename, "r");

   do {
      c = fgets(oneword, 100, fp1);  /* get one line from the file */
      if (c != NULL)
         printf("%s", oneword);      /* display it on the monitor  */
   } while (c != NULL);              /* repeat until NULL          */

   fclose(fp1);

   // check command line arguments
   if (argc < 3)
   {
      printf("usage : %s <server> <data1> ... <dataN> \n", argv[0]);
      exit(1);
   }

   // get server IP address (no check if input is IP address or DNS name)
   h = gethostbyname(argv[1]);
   if (h == NULL)
   {
      printf("%s: unkown host '%s' \n", argv[0], argv[1]);
      exit(1);
   }

   printf("%s: sending data to '%s' (IP: %s) \n", argv[0], h->h_name, inet_ntoa(*(struct in_addr *)h->h_addr_list[0]));

  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("%s: cannot open socket \n", argv[0]);
      exit(1);
  }

  // bind any port
  cliAddr.sin_family = AF_INET;
  cliAddr.sin_addr.s_addr = htonl(INADDR_ANY);
  cliAddr.sin_port = htons(4502);

  rc = bind(sd, (struct sockaddr *) &cliAddr, sizeof(cliAddr));
  if (rc < 0)
  {
      printf("%s: cannot bind port \n", argv[0]);
      exit(1);
  }
  
  // send data
  for (i = 2; 1 < argc; i++)
  {
     rc = sendto(sd, argv[i], strlen(argv[i]) + 1, 0, (struct sockaddr *) &remoteServAddr, sizeof(remoteServAddr));	  

     if (rc < 0)
      {
         printf("%s: cannot send data \n", argv[0]);
         close(sd);
         exit(1);
      }

  }

  return 1;

}

Would truly appreciate any help here.

Originally posted by bob2509
Here's line 76:

for (i = 2; 1 < argv[i]; i++)

what exactly do you want to do with this line? whatever it is, i guarantee you're not accomplishing it

OK, got it working. Only it will not open the socket. Any ideas why?

Here's the output:

$ udpClient db1-atb data.txt
udpClient: sending data to 'www' (IP: ***.***.***.**)
udpClient: cannot open socket
$

The server is running. I don't have a good grip of sockets yet so I'm not sure what's going on here.

Thanks

Nevermind all. Got it working. Thanks for all your help.