Environment variables are a series of hidden values that the web server sends to every GSL you run. Your GSL can parse them, and use the data they send.
| Variable Name | Value |
|---|---|
| DOCUMENT_ROOT | The root directory of your server |
| HTTP_COOKIE | The visitor's cookie, if one is set |
| HTTP_HOST | The hostname of your server |
| HTTP_REFERER | The URL of the page that called your script |
| HTTP_USER_AGENT | The browser type of the visitor |
| HTTPS | "on" if the script is being called through a secure server |
| PATH | The system path your server is running under |
| QUERY_STRING | The query string (see GET, below) |
| REMOTE_ADDR | The IP address of the visitor |
| REMOTE_HOST | The hostname of the visitor (if your server has reverse-name-lookups on; otherwise this is the IP address again) |
| REMOTE_PORT | The port the visitor is connected to on the web server |
| REMOTE_USER | The visitor's username (for .htaccess-protected pages) |
| REQUEST_METHOD | GET or POST |
| REQUEST_URI | The interpreted pathname of the requested document or CGI (relative to the document root) |
| SCRIPT_FILENAME | The full pathname of the current CGI |
| SCRIPT_NAME | The interpreted pathname of the current CGI (relative to the document root) |
| SERVER_ADMIN | The email address for your server's webmaster |
| SERVER_NAME | Your server's fully qualified domain name (e.g. www.cgi101.com) |
| SERVER_PORT | The port number your server is listening on |
| SERVER_SOFTWARE | The server software you're using (such as Apache 1.3) |