NAME

     ssi — Server-Side-Includes CGI program

SYNOPSIS

     ssi

DESCRIPTION

     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) and merecat(8), but should be easy to
     adapt to other systems.

     There are two ways to use this; the modern way of using a .shtml pattern in merecat.conf(5) to trigger the
     SSI script, which requires enabling the SSI module.  Then there is the traditional thttpd(8) approach.  We
     start with the relevant settings needed in merecat.conf:

           ssi {
               enabled = true
               pattern = "**.shtml"        # default
               cgi-path = "cgi-bin/ssi"    # default, web server root is used
           }

     The traditional thttpd 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:

         http://www.acme.com/cgi-bin/ssi

     and the url for the document is:

         http://www.acme.com/users/wecoyote/doc.html

     then the compound URL would be:

         http://www.acme.com/cgi-bin/ssi/users/wecoyote/doc.html

INCLUDE FORMAT

     The format description below is adapted from ⟨http://hoohoo.ncsa.uiuc.edu/docs/tutorials/includes.html⟩.

     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" -->

     Note: 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:

     config  The config directive controls various aspects of the file parsing.  There are two valid tags:

             timefmt
                     gives the server a new format to use when providing dates.  This is a string compatible
                     with the strftime(3) library call.

             sizefmt
                     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.

             errmsg  overrides the default; "[an error occurred while processing this directive]"

     include
             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:

             virtual
                     Gives a virtual path to a document on the server.

             file    Gives a pathname relative to the current directory. ../ cannot be used in this pathname,
                     nor can absolute paths be used.

     echo    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.

     fsize   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 command.

     flastmod
             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.

VARIABLES

     A number of variables are made available to parsed documents.  In addition to the CGI variable set, the
     following variables are made available:

     DOCUMENT_NAME
             The current filename.

     DOCUMENT_URI
             The virtual path to this document (such as /~robm/foo.shtml).

     QUERY_STRING_UNESCAPED
             The unescaped version of any search query the client sent.

     DATE_LOCAL
             The current date, local time zone.  Subject to the timefmt parameter to the config command.

     DATE_GMT
             Same as DATE_LOCAL but in Greenwich mean time (GMT).

     LAST_MODIFIED
             The last modification date of the current document.  Subject to timefmt like the others.

SEE ALSO

     merecat(8), merecat.conf(5), strftime(3)

AUTHORS

     Jef Poskanzer <jef@mail.acme.com> wrote the original for use with thttpd.
     Joachim Wiberg <troglobit@gmail.com> added minor features and a trigger in merecat for .shtml pages.

BUGS

     Does not implement all "modern" SSI directives are supported. E.g., exec cgi and exec cmd or any control
     directives like if, elif, else, endif, etc.  Patches and pull-requests are welcome :)