Thread: QUERY_STRING in CGI with a C/C++ Program

I am writing a CGI program in C++. When my web server passes environment variables on to the program it send them seperated, eg: If the query string (following the '?') said paul+rules, my program is passed the variables 'paul' and 'rules'. I have no way of knowing if it was a plus or a = sign that was joing the variables.

Also, if I write a perl script in CGI I am able to access variables like PATH_INFO, and one that carries the users IP Address. I seem unable to access those.

If anyone has any idea's on this subject or know's a place with a lot of people who do, could you please reply?

Thanks for listening to me ramble, Paul.

Nah Like you I expected to get the whole thing, and I wanted to as well, but all I get is

paulscript.ps?username=freddy

Code:

argv[0]=program.exe
argv[1]=paulscript.ps
argv[2]=username
argv[3]=freddy

Ahhh CGI. I wrote a C/C++ library to use CGI sometime last year. Was going to incorporate ODBC tools into it, but I never go around to it.

Two things, you have POST and GET methods to worry about.

When you POST (fill out a from and click submit) you are using the standard input stream...you guessed it "cin". My suggestion (and it's what I did) is to write a loop to loop until you stop getting data from cin.

When you GET (click on a link...you can also GET forms) you need to get your query string. The method getenv("QUERY_STRING") will get it for you. It is not passed as a parameter to the main program...at least not from what I've seen.

Here's a list of enviromental variables you can get:
getenv ("SERVER_SOFTWARE");
getenv ("SERVER_NAME");
getenv ("GATEWAY_INTERFACE");
getenv ("SERVER_PROTOCOL");
getenv ("SERVER_PORT");
getenv ("REQUEST_METHOD");
getenv ("PATH_INFO");
getenv ("PATH_TRANSLATED");
getenv ("SCRIPT_NAME");
getenv ("QUERY_STRING");
getenv ("REMOTE_HOST");
getenv ("REMOTE_ADDR");
getenv ("AUTH_TYPE");
getenv ("REMOTE_USER");
getenv ("REMOTE_IDENT");
getenv ("CONTENT_TYPE");
getenv ("HTTP_ACCEPT");
getenv ("HTTP_USER_AGENT");
getenv ("HTTP_REFERER");

Now with the query string, you WILL have to parse it. What you will have to parse out are, special characters, convert hex values to characters (such as &, =, +, etc...), all your variable names and appropriate values. If the variable name doesn't exist in the query string, there was no data assigned to it.

If you'd like, I have no problem sending you my code to browse through it.