Server-Side Includes¶

• Table of contents
• Server-Side Includes
  • Description
  • Configuration
  • Supported Options
  • Expression Handling
  • Flow Control
  • Unsupported Features

Module: mod_ssi

Description¶

SSI is a very old and cheap way to generate content dynamically on server-side.

The use of this module is strongly discouraged:

• the execution of a SSI script is done in the server-core
• a long-running SSI script blocks the handling of ALL connections
• as soon as you use #exec the performance gets worse than using CGI scripts directly

You should only use SSI for two reason:

• content assembling with #include
• legacy applications

Configuration¶

You have to load the mod_ssi module and set the ssi-extension:

server.modules = ( ..., "mod_ssi", ... ) #Note that if you use mod_compress mod_ssi must come first to function.
ssi.extension = ( ".shtml" )

Supported Options¶

 <!--#echo var="..." -->
  <!--#echo var="DOCUMENT_ROOT"-->
 <!--#include file="..."\|virtual="..." -->
 <!--#flastmod file="..."\|virtual="..." -->
 <!--#fsize file="..."\|virtual="..." -->
 <!--#config timefmt="..." sizefmt="(bytes|abbrev)" -->
 <!--#printenv -->
 <!--#set var="..." value="..." -->
 <!--#if expr="..." -->
 <!--#elif expr="..." -->
 <!--#else -->
 <!--#endif -->
 <!--#exec cmd="..." -->
 <!--#exec cmd="date"-->

Expression Handling¶

Every "expr" is interpreted:

• logical: AND, OR, !
• compare: =, <, <=, >, =>, !=
• precedence: (, )
• quoted strings: 'string with a dollar: $FOO'
• variable substitution: $REMOTE_ADDR
• unquoted strings: string

Flow Control¶

if, elif, else and endif can only be used to insert content under special conditions.

Unsupported Features¶

The original SSI module from NCSA and Apache provided some more options which are not supported by this module for various reasons:

• nested requests with `include virtual`: use exec to execute scripts or apply the patch at http://trac.lighttpd.net/trac/ticket/536
• `echo var` for SSI variables: it only works for environment variables if you don't apply patch at http://trac.lighttpd.net/trac/ticket/795
• config.errmsg
• echo.encoding