Server-Side-Includes CGI program
This is an external CGI program that provides the same functionality as the
built-in server-side-includes feature in many HTTP daemons. It is written for
use with thttpd(8)
, but should be easy to adapt to other
There are two ways to use this; the modern way of using a
to trigger the SSI script, which
requires enabling the SSI module. Then there is the traditional
approach. We start with the relevant
settings needed in
enabled = true
pattern = "**.shtml" # default
cgi-path = "cgi-bin/ssi" # default, web server root is used
way runs ssi as a
simple CGI script, which requires placing the ssi binary in the web server CGI
area, and enabling CGI. Then set up URLs with the path to the document to
parse as the "pathinfo". That's the part of the URL that comes after
the CGI program name. For example, if the URL to this program is:
and the url for the document is:
then the compound URL would be:
The format description below is adapted from
All directives are formatted as SGML comments within the document. This is in
case the document should ever find itself in the client's hands unparsed. Each
directive has the following format:
<!--#command tag1="value1" tag2="value2" -->
the lack of space between the initial HTML
comment start and the #command. This is explicitly stated in the standard and
strictly enforced by all web servers implementing SSI.
Each command takes different arguments, most only accept one tag at a time. Here
is a breakdown of the commands and their associated tags:
- The config directive controls various aspects of the file parsing. There
are two valid tags:
- gives the server a new format to use when providing dates. This is a
string compatible with the strftime(3)
- determines the formatting to be used when displaying the size of a
file. Valid choices are bytes, for a formatted byte count (formatted
as 1,234,567), or abbrev for an abbreviated version displaying the
number of kilobytes or megabytes the file occupies.
- overrides the default; “[an error occurred while processing
- Inserts the text of another document into the parsed document. The
inserted file is parsed recursively, so it can contain server-side-include
directives too. This command accepts two tags:
- Gives a virtual path to a document on the server.
- Gives a pathname relative to the current directory. ../ cannot be used
in this pathname, nor can absolute paths be used.
- Prints the value of one of the include variables (defined below). Any
dates are printed subject to the currently configured timefmt. The only
valid tag to this command is var, whose value is the name of the variable
you wish to echo.
- prints the size of the specified file, subject to the sizefmt parameter to
the config command. Valid tags are the same as with the include
- prints the last modification date of the specified file, subject to the
formatting preference given by the timefmt parameter to config. Valid tags
are the same as with the include command.
A number of variables are made available to parsed documents. In addition to the
CGI variable set, the following variables are made available:
- The current filename.
- The virtual path to this document (such as /~robm/foo.shtml).
- The unescaped version of any search query the client sent.
- The current date, local time zone. Subject to the timefmt parameter to the
- Same as
DATE_LOCAL but in Greenwich
mean time (GMT).
- The last modification date of the current document. Subject to timefmt
like the others.
⟨firstname.lastname@example.org⟩ wrote the original for use with
⟨email@example.com⟩ added minor features and a trigger in
Does not implement all "modern" SSI directives are supported. E.g.,
or any control directives like
if, elif, else, endif,
etc. Patches and
pull-requests are welcome :)