It should be possible for you to set a few environment variables to simulate the environment that your CGI script is executed in by the server responding to client request (via browser). What I normally do is set these variables:

• QUERY_STRING (set this to standard URL query string -- whatever comes after the ? character)
• HTTP_COOKIE (if you deal with cookies)
• SERVER_NAME (optional)

After that simply run your script from command line as you'd normally do. Normally any methods you use in your script to process CGI data (parameters etc) should work fine.

"There is no system but GNU, and Linux is one of its kernels." -- Confession of Faith