simple.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include "cgi.h"

/* A simple CGI program.  It grabs the form data from the environment variable
 * QUERY_STRING and prints it as an html list if QUERY_STRING is not empty
 *
 * It first prints a header line to indicate the content type.  Note that
 * header lines are terminated with crlf (carriage return, line feed)
 * characters, and there must be a blank line between the end of the
 * headers and the beginning of the body of the http message 
 */

int main() {
    char *name, *qstr = NULL;
    Fdata *f = NULL;

  printf("Content-type: text/html\r\n\r\n");
  printf("<html><head>\n");
  printf("<title>Hello World</title>\n");
  printf("<link rel=\"icon\" href=\"data:,\"></head>\n");
  printf("<body>\n");
  printf("<h2>Hello, world!</h2>\n");
  if((name = getenv("QUERY_STRING")) != NULL) {
      printf("<p>QUERY_STRING = %s</p>\n", name);
        /* We aren't allowed to modify the string returned from getenv, 
         * so make a copy */
        if(strlen(name) > 0) {
            qstr = malloc(strlen(name) + 1);
            strncpy(qstr, name, strlen(name) + 1);

            f = parse_query(qstr);
            printf("%s", fdata2html(f));
        }
    }
    printf("</body></html>\n");
    fflush(stdout);

    if(f != NULL) {
        fdata_free(f);
    }
    if(qstr != NULL) {
        free(qstr);
    }
    return 0;
}