Submitting HTML GET/POST Requests to a CGI Program

Submitting a CGI GET or POST query is made simple using ToolsPro's RWIHttpClient and RWIHttpAgent classes.

The first and most important step is to constuct a valid query string to send to the CGI program. Data is sent as key/value pairs, where the same key may be used multiple times. Keys are seperated from values with the '=' character, and key/value pairs are separated by the '&'. The ' ' is rewritten to a '+', and most other special characters are recoded as a '%' character followed by the hexadecimal value of the character.

To send a greeting Hello World, and a farewell Goodbye All as a POST request, we will send the following query string to the server.

   greeting=Hello+World&farewell=Goodbye+All 

Once we have encoded our data, we can GET/POST it.

Sending the data is simple. All that we need to do is create a RWIHttpClient (or RWIHttpAgent) instance, connect to the server, and then submit the request.

   RWCString url;  // path to CGI script on HTTP server   RWCString data; // contains CGI query string described above 
     // create client and connect   RWIHttpClient client(RWIHttpVersion_1_0());   if(!client.connect('www.somewhere.org')) { cerr     <<  'connect failed...' <<  endl;     exit(1);   } 
     // create a POST request and append query string   RWIHttpPost post(url);   post.append(data); 
   /* Here is the code when using GET     // create a GET request   url.append('?' + data);   RWIHttpGet get(url); 
     // send GET request   RWIHttpReply reply = client.execute(get);   */ 
     // send POST request   RWIHttpReply reply = client.execute(post);   if(!reply.is2XX()) { cerr     <<  'bad reply code: ' << reply.code()  <<  endl;   } 
   RWNetBuf  buffer;   RWCString result;   RWPortal  portal = reply.portal(); 
     // read reply from server   while(buffer = portal.recv())     result += buffer;          // and display it   cout << result <<   endl;