You can use SSI directives to output the values of environment variables in an otherwise static HTML document. These might be standard CGI variables (listed in Chapter 11, CGI Environment Variables) or they might be:
The current file
You are reading a document called: <!--#echo var="DOCUMENT_NAME"-->
Virtual path to the file
You can access this document again by pointing to the URL: <!--#echo var="DOCUMENT_URL"-->
Undecoded query string with all shell metacharacters escaped with a backslash ( \ )
Current date and time in the local time zone
The time is now <!--#echo var="DATE_LOCAL"-->
Current date and time in Greenwich Mean Time
The Greenwich Mean Time is <!--#echo var="DATE_GMT"-->
Last modification date and time for current file
The current document was last modified on: <!--#echo var="LAST_MODIFIED"-->