What is SSI?

Server Side Includes allow users to create documents which provide simple information to clients on the fly. Such information can include the current date, the file's last modification date, and the size or last modification of other files. In its more advanced usage, it can provide a powerful interface to CGI and shell programs.
When using a UNIX system it is sometimes necessary to enable certain HTML files executable for the purpose of using SSI. Server Side Includes are often used to run a cgi script. An include is called with an example such as this: After you insert your include, you must mark the HTML file as executable so the server will parse the file. This is done using one of two options.

1.) Renaming the file to .shtml: On our server any file name .shtml will be parsed. So instead of having an index.html file, you would name it index.shtml. This is the easiest way of enabling includes.

2.) CHMODing the file to 777: With CHMOD 777 you can also mark a file as executable. It is important to only make the files which you want parsed executable. This poses certain security issues, as well as a strain on our resources, as the processor has to work harder to
parse a file.