IIS: Notes on Server-Side Includes (SSI) syntax

29. October 1998 Bob IIS Comments (0)

A few years ago I put together a bunch of notes about using Server-Side-Include (SSI) files with IIS 4. These notes eventually became Microsoft KB article Q203064, and I updated that information a couple of years later to incorporate IIS 5. This information is no longer available from Microsoft's support website, so I thought that it would make a good blog post.

SUMMARY

This article details some features that are available in the Microsoft implementation of Server-Side Include (SSI) files for Internet Information Server (IIS) and provides general syntax and examples for SSI directives.

APPLIES TO

  • Microsoft Internet Information Services 5.0
  • Microsoft Internet Information Server 4.0

MORE INFORMATION

SSI files are most commonly used with IIS to allow content authors to include the contents of one file inside another file, allowing the easy creation of script libraries or page headers and footers.

SSI files, like Active Server Pages (ASP) and Internet Data Connector (IDC) files, are script-mapped by file extension to a preprocessor dynamic-link library (DLL). In the case of SSI, the handler is Ssiinc.dll. SSI files are usually named with .stm file extensions, although extensions of .shtm and .shtml are also supported.

SSI is employed by the use of special preprocessing directives in SSI documents. These directives are parsed by the SSI DLL and processed. All directives are contained in HTML comment tokens and take the following general form: 

<!--#<DIRECTIVE> [<ADDITIONAL DATA>]-->

Supported Directives

The following directives are supported in the IIS implementation of SSI:
  • #config - Configures how variables and commands are displayed.
    • The general syntax for the #config directive is as follows: 
      <!-- #CONFIG <ERRMSG/TIMEFMT/SIZEFMT>="<format>" -->
    • The following is an example of a simple page that uses the #config directive: 
      <html>
<body>
<!-- #CONFIG TIMEFMT="%m/%d/%y" -->
<p>Today's Date = <!--#ECHO VAR = "DATE_LOCAL" --></p>
<!-- #CONFIG TIMEFMT="%A, %B %d, %Y" -->
<p>Today's Date = <!--#ECHO VAR = "DATE_LOCAL" --></p>
</body>
</html>
  • #echo - Inserts the value of various Common Gateway Interface (CGI) system environment variables.
    • The general syntax for the #echo directive is as follows: 
      <!--#ECHO VAR = "<CGI_VARIABLE_NAME>"-->
    • The following is an example of a simple page that uses the #echo directive: 
      <html>
<body>
<p>Server Name = <!--#ECHO VAR = "SERVER_NAME"--></p>
<p>Date = <!--#ECHO VAR = "DATE_LOCAL" --></p>
<p>Page URL = <!--#ECHO VAR = "URL" --></p>
</body>
</html>
  • #exec - Executes CGI or Internet Server API (ISAPI) command scripts and inserts output into an HTML document.
    • The general syntax for the #exec directive is as follows: 
      <!-- #EXEC <CGI/CMD>="<command>" -->
    • The CMD command for the #exec directive is disabled by default on IIS 5.0. For more information, see the following Microsoft Knowledge Base article:

      233969 SSIEnableCmdDirective is set to FALSE by default

    • The following is an example of a simple page that uses the #exec directive: 
      <html>
<body>
<p>Root Directory of C:</p>
<pre><!--#EXEC CMD="cmd /c dir c:\ /b"--></pre>
</body>
</html>
  • #flastmod - Retrieves the last modification time of a specified file.
    • The general syntax for the #flastmod directive is as follows: 
      <!--#FLASTMOD <FILE/VIRTUAL> = "filename.ext"-->
    • The following is an example of a simple page that uses the #flastmod and #config directives: 
      <html>
<body>
<!-- #CONFIG TIMEFMT="%m/%d/%y" -->
<p>Modified Date = <!--#FLASTMOD FILE="filename.ext"--></p>
<!-- #CONFIG TIMEFMT="%B %d, %Y" -->
<p>Modified Date = <!--#FLASTMOD FILE="filename.ext"--></p>
</body>
</html>
  • #fsize - Retrieves the size of a specified file.
    • The general syntax for the #fsize directive is as follows: 
      <!--#FSIZE <FILE/VIRTUAL> = "filename.ext"-->
    • The following is an example of a simple page that uses the #fsize and #config directives: 
      <html>
<body>
<!-- #CONFIG SIZEFMT="BYTES" -->
<p>File Size = <!--#FSIZE FILE="filename.ext"--> bytes</p>
<!-- #CONFIG SIZEFMT="ABBREV" -->
<p>File Size = <!--#FSIZE FILE="filename.ext"--> KB</p>
</body>
</html>
  • #include - Includes the contents of one specified file inside another.
    • The general syntax for the #include directive is as follows: 
      <!--#INCLUDE <FILE/VIRTUAL> = "filename.ext"-->
    • The following is an example of a simple page that uses the #include directive: 
      <html>
<body>
<!--#INCLUDE FILE = "header.inc"-->
<p>Hello World!</p>
<!--#INCLUDE VIRTUAL = "/includes/footer.inc"-->
</body>
</html>

More Information on File and Virtual Syntax

SSI directives that use file paths can reference files by using a file or virtual path.
  • The file element is used with files that are relative to the folder of the current document. The following example includes a file in the current folder: 
    <!--#include file="myfile.txt"-->
  • The virtual element represents paths that are relative to the base folder of the Web server. The following example includes a file in the /scripts virtual folder: 
    <!--#include virtual="/scripts/myfile.txt"-->

REFERENCES

For additional information on using SSI with IIS, click the following article numbers to view the articles in the Microsoft Knowledge Base:

  • 169996 To run an ISAPI DLL with #exec, use the CGI statement
  • 166491 Secure batch files return access denied error message
  • 195291 How to disable #exec in Server-Side Include files