Lihtsaid cgi programminäiteid

proov.sh on shelli skript, mis trükib välja serverile saadetud info:

#!/bin/sh
echo 'Content-type: text/html'
echo
echo
echo 'tere tali'
echo '<p>'
echo $QUERY_STRING

proov.py on pythoni programm, mis parsib serverile saadetud info (cgi protokolli järgi), trükib argumendid ja liidab nende väärtused kokku:

#!/usr/bin/python

import string, os, cgi, sys, tempfile, traceback
import cgitb; 


def main():
  print 'content-type: text/html\n\n' 
  print '<h2>Väike näide</h2>' 
  cgitb.enable()
  form = cgi.FieldStorage() 
  sum=0 
  for key in form.keys():  
    val=form[key].value
    print key,' võrdub ',val
    print '<br>'
    sum=sum+int(val) 
  print '<p>'  
  print '<b>summa on: ',sum,'</b>' 
  return

main()

järgmine C-keelne rakendus kuvab serverile saadetud info

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


void getquery_str();

int main(int argc, char **argv) {
  printf("content-type: text/plain\n\n");
  printf("Hello!\n");
  
  getquery_str();
}  


void getquery_str() {
  char* result;
  char* tmp1;
  char* tmp2;
  
  tmp1=getenv("QUERY_STRING");
  tmp2=getenv("SCRIPT_NAME");
  
  printf("QUERY_STRING: %s\n",tmp1);
  printf("SCRIPT_NAME: %s\n",tmp2);
}  

adder.c on C-s kirjutatud rakendus, mis parsib kaks argumenti (eeldades ampersandi eraldajaks ja nimede puudumist!) ja liidab nad kokku. Mingeid teeke peale standardse ei kasutata.

/*
 * adder.c - a minimal CGI program that adds two numbers together
 */
/* $begin adder */
#include "csapp.h"

int main(void) {
    char *buf, *p;
    char arg1[MAXLINE], arg2[MAXLINE], content[MAXLINE];
    int n1=0, n2=0;

    /* Extract the two arguments */
    if ((buf = getenv("QUERY_STRING")) != NULL) {
        p = strchr(buf, '&');
        *p = '\0';
        strcpy(arg1, buf);
        strcpy(arg2, p+1);
        n1 = atoi(arg1);
        n2 = atoi(arg2);
    }

    /* Make the response body */
    sprintf(content, "Welcome to add.com: ");
    sprintf(content, "%sTHE Internet addition portal.\r\n<p>", content);
    sprintf(content, "%sThe answer is: %d + %d = %d\r\n<p>", 
            content, n1, n2, n1 + n2);
    sprintf(content, "%sThanks for visiting!\r\n", content);
  
    /* Generate the HTTP response */
    printf("Content-length: %d\r\n", strlen(content));
    printf("Content-type: text/html\r\n\r\n");
    printf("%s", content);
    fflush(stdout);
    exit(0);
}
/* $end adder */