<!--#echo var="$env" -->

When you try to echo something that is invalid you get the following error message: (none)

<!--#echo var="DOCUMENT_NAME" -->

This is the name of the document the echo command is in: ssi3.shtml

<!--#echo var="DOCUMENT_uri" -->
The path to this file is /pub/doc/linux/ssi3.shtml.
<!--#echo var="DATE_LOCAL" -->
The current local time is Tuesday, 23-Apr-2024 13:43:35 CEST.
<!--#echo var="DATE_GMT" -->
The Greenwich Mean Time is Tuesday, 23-Apr-2024 11:43:35 GMT.
<!--#echo var="last_modified" -->
This file was last modified on Sunday, 12-May-2002 11:10:09 CEST.
If you include a file that has the echo commands in it, all of the echo commands refer to the main file.