There are SSI directives that allow you to retrieve certain information about files located on your server. For example, say you have a hypertext link in one of your documents that points to a manual describing your software that users can download. In such a case, you should include the size and modification date of that manual so users can decide whether it's worth their effort to download a document; it could be outdated or just too large for them to download. Here's an example:
Here is the latest reference guide on CGI. You can download it by clicking <A HREF="/cgi-refguide.ps">here</A>. The size of the file is <!--#fsize file="/cgi-refguide.ps"--> bytes and was last modified on <!--#flastmod file="/cgi-refguide.ps"-->.
The fsize command, along with its lone parameter, file, displays the size of the specified file (relative to the document root) in bytes. You can use the flastmod command to insert the modification date for a certain file. The difference between the SSI variable LAST_MODIFIED and this command is that flastmod allows you to choose any file, while LAST_MODIFIED displays the information for the current file. You have the option of tailoring the output from these commands with the config command. We will look at this later in the chapter.