Help Parsing a URL

This is a skeleton of something I am currently using.  I got it from bejee's socket programming tutorial.  Google it.  anyways, this should pretty much compile and run (if I didn't miss any errors.  I don't have a compiler here), at least is linux eviroment.  If you are using windows, google that tutorial and you can learn the differences.  Hope this helps.



Here is the basic layout:

#define FILESIZE 100000  /* size of download -- change as needed */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>  /* Important to gethostname */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>



int main(int argc, char **argv)
{
  int sockfd;
  struct sockaddr_in dest_addr;
  struct hostent *host;

  char *stream;

  /* Don't forget to check the args */
 
  /* Build the GET command for the download */

  b_send = (char *)malloc(31*sizeof(char));
  strcpy(b_send, "GET file.html\r\n");  /* file.html is the your file.html */

  /* Resolve the Hostname */

  if((host = gethostbyname(argv[1])) == NULL )
  {
    herror("gethostbyname()");
    exit(1);
  }

  /* Open the socket */

  sockfd = socket(host->h_addrtype, SOCK_STREAM, 0);
  if (sockfd == -1)
  {
    printf("socket() failed.\n");
    exit(1);
  }


  /* Build the Destination Address Struct */

  memset(&(dest_addr.sin_family), '\0', sizeof(struct sockaddr_in));
  dest_addr.sin_family = AF_INET;
  dest_addr.sin_port = htons(DEST_PORT);
  memcpy(&dest_addr.sin_addr.s_addr, host->h_addr, host->h_length);


  /* Connect to destination Address */

  if ((connect(sockfd, (struct sockaddr *)&dest_addr, sizeof(dest_addr))) == -1)
  {
      perror("connect()");
        printf("      %s : %d\n", sys_errlist[errno], errno);
      exit(1);
  }


  /* Send GET /..... */

  if((bytes_sent = send(sockfd, b_send, strlen(b_send), 0)) == -1)
  {
    perror("send()");
  }


  /* Allocate the receive memory and open the out file */

  b_recv = malloc(1500);
  stream = malloc(FILESIZE);
  strcpy(stream, "");
 
  /* Receive the information in blocks of 1500 bytes */

  while((bytes_recv = recv(sockfd, b_recv, 1500, 0)) > 0)
  {
    strcat(b_recv, sizeof(char), bytes_recv, ofp);
  }

  if(bytes_recv == -1)
  {
    perror("recv()");
  }

  close(sockfd);
  free(b_send);
  free(b_recv);
  free(stream);

  return 0;
}

oops, guess you did't want all that.  i should read the question more carefully.  good job kdo.

Hi Kent...thanks for the reply.....I tried implementing the following simple program but it does not seem to work.  Do you have any more suggestions:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (int argc, char **argv)
(

char *p1;
char *p2;
char *p3;
char *String;

if (argc != 2)
{
    printf("usage: <URL containing IP address and Path>
    exit(1);
}

String = argv[1];


p1 = strtok (String, "/");
p2 = strtok (NULL, "/");
p3 = strtok (NULL, "/");

printf("P1 is %s\n", p1);
printf("P2 is %s\n", p2);
printf("P3 is %s\n", p3);

exit(0);
)

String = argv[0];

Try it, I'm not 100% sure though....

Also :

printf("usage: <URL containing IP address and Path>

should be :

printf("usage: <URL containing IP address and Path>");

btw : you should know that the strtok() function modifies its first argument (in this case argv[1]). If you don't want that to happen, do this :

int length = strlen(argv[1]) + 1;
String = (char*) malloc(length*sizeof(char));
strncpy(String, argv[1],length);

instead of :

String = argv[1];

>>btw ...
Yes! I came across this one a while ago. On Windoze 32 the 'argv' array passed to main is actually in protected memory space so its better to copy it. However, 'strdup' might be a tidier function to use:

char * string = strdup(argv[1]);

Paul