cookies.c

this gives details of the network programming

#include <stdio.h>
#include <stdlib.h>	/* for getenv */
#include <string.h>

/* extract a list of cookies from the HTTP_COOKIE environment variable.
   fills in 2 arrays with the names and values of each cookie found.

   cookies are seperated by the ';'.

   returns the number of cookies found.

   the cookie names are put in the array names, the 
   values in vals - this function assumes both exist and
   have room for maxcookies elements (each element is a (char *).

   I have a hard time with a variable named maxcookies, since
   there is no such thing as a maximum number of cookies. 
   There are never enough cookies for me...
*/


int get_cookies(char **names, char **vals, int maxcookies) {
  int n=0;

  char *cookies;
  char *ptr;
  char *eqs;


  cookies = getenv("HTTP_COOKIE");
  if (! cookies) 
    return(0);	/* no cookies found (sigh...) */
  
  ptr = strtok(cookies,";");
  while (ptr) {		/* while cookies remain */
    /* find the = sign everything before it is the name
       and everything after it is the value */
    eqs = strchr(ptr,'=');
    if (!eqs) break;  /* not found - give up */
    *eqs=0;
    if (*ptr==' ') ptr++;
    names[n]=strdup(ptr);	/* make a copy of the cookie name */
    vals[n] = strdup(eqs+1);	/* make a copy of the cookie value */
    
    /* if everything worked - move on 
       otherwise give up looking any furthur
    */

    if (names[n] && vals[n]) {
      n++;
    } else {
      break;  /* some problem, give up and return what we now have */
    }
    ptr = strtok(NULL,";");

  }

  return(n);
}



/* given a pair of arrays containing pointers to cookie names
   and values, extract a named cookie and return it's value */

char *cookie_lookup(char **names, char **vals, int num, char *cookiename) {
  int i;
  int len = strlen(cookiename);

  for (i=0;i<num;i++) {
    if (strncmp(names[i],cookiename,len)==0 ) {
      /* found it - return the value */
      return(vals[i]);
    }
  }
  return(NULL);
}