Sample applications

Sample applications include (but are certainly not limited to):

• Counters
• Random picture selectors
• Random quotation (fortune) generators

File inclusion

Variable and functions expansion

Certain variables and functions can be expanded inline without running any external programs. Some examples -- tags paired with their output -- follow.

Server-side includes may also run other programs. These programs will be run as whichever user the web server runs as, often guest or nobody. For example, the server-side tag:
<!--#exec cmd="/bin/ls -l /home/webman/public_html/readme/ssi.shtml" -->
produces the following output:
-r--r--r-- 1 webman webstaff 9755 Jan 20 2002 /home/webman/public_html/readme/ssi.shtml

Here is another server-side tag:
<!--#exec cmd="/usr/cs/contrib/bin/fortune" -->
This generates a random quotation/fortune. Like this:

This SSI is a simple counter. The external executable counts the number of hits the page has received and prints it into the page.
<!--#exec cgi="/cgi-bin/counter" -->
[1]

This SSI is a Roman-numeral counter. The external executable counts the number of hits and converts it to a Roman numeral.
<!--#exec cgi="/cgi-bin/romcount" -->
[DXLV]

Note that there are three different forms used for calling an external executable:

• <!--#exec cmd="path" --> takes an absolute path runs any executable.
• <!--#exec cgi="path" --> takes a relative path (like a URL) and runs CGI-style executables. The executable is responsible for returning a content-type header. This method is preferred over "exec cmd" because it uses relative paths and allows redirection.
• <!--#include virtual="path" --> takes also takes a relative path, but unlike "exec cgi", it detects whether the specified file is a script to run or a file to include. This is the best method to use.

References