This module provides for server-parsed html documents.
Status: Base
Source File:
mod_include.c
Module Identifier:
includes_module
This module provides a filter which will process files before they are sent to the client. The processing is controlled by specially formated SGML comments, referred to as elements. These elements allow conditional text, the inclusion other files or programs, as well as the setting and printing of environment variables.
See also: Options and SetOutputFilter.
Server Side Includes are implemented by the
INCLUDES filter. If
documents containing server-side include directives are given
the extension .shtml, the following directives will make Apache
parse them and assign the resulting document the mime type of
text/html:
AddType text/html .shtml
<FilesMatch "\.shtml(\..+)?$">
SetOutputFilter INCLUDES
</FilesMatch>
Be careful to properly scope the INCLUDES filter to process
only the correct files. The filter is not
restricted to processing only HTML files. So, for example, if
the INCLUDES filter is activated using a
<Directory> section and that directory
includes GIF files, mod_include will process the GIF files.
This can have two adverse consequences: 1. there will be extra
overhead in serving these files, and 2. these files could
become corrupted if they happen to contain something that looks
like an SSI element.
The following directive must be given for the directories
containing the shtml files (typically in a
<Directory> section, but this directive is
also valid .htaccess files if AllowOverride
Options is set):
Options +Includes
For backwards compatibility, the server-parsed
handler also activates the
INCLUDES filter. As well, Apache will activate the INCLUDES
filter for any document with mime type
text/x-server-parsed-html or
text/x-server-parsed-html3 (and the resulting
output will have the mime type text/html).
For more information, see our Tutorial on Server Side Includes.
The value will often be enclosed in double quotes; many commands only allow a single attribute-value pair. Note that the comment terminator (-->) should be preceded by whitespace to ensure that it isn't considered part of an SSI token.<!--#element attribute=value attribute=value ...-->
The allowed elements are:
bytes
for a count in bytes, or abbrev for a count
in Kb or Mb as appropriate.strftime(3) library routine when printing
dates.(none). Any dates printed are subject to the
currently configured timefmt. Attributes:
echo element,
the default is set to "entity", resulting in entity
encoding (which is appropriate in the context of a
block-level HTML element, eg. a paragraph of text). This
can be changed by adding an encoding
attribute, which will remain in effect until the next
encoding attribute is encountered or the
element ends, whichever comes first. Note that the
encoding attribute must precede the
corresponding var attribute to be effective,
and that only special characters as defined in the
ISO-8859-1 character encoding will be encoded. This
encoding process may not have the desired result if a
different character encoding is in use. Apache 1.3.12 and
above; previous versions do no encoding.The CGI script is given the PATH_INFO and query string (QUERY_STRING) of the original request from the client; these cannot be specified in the URL path. The include variables will be available to the script in addition to the standard CGI environment.
If the script returns a Location: header instead of output, then this will be translated into an HTML anchor.
The include virtual element should be
used in preference to exec cgi.
/bin/sh. The include variables are available
to the command.sizefmt format specification.
Attributes:
timefmt format
specification. The attributes are the same as for the
fsize command.An attribute defines the location of the document; the inclusion is done for each attribute given to the include command. The valid attributes are:
../, nor can it be an absolute path.
The virtual attribute should always be used
in preference to this one.echo element for details)
before being output. No attributes.<!--#printenv --><!--#set var="category" value="help"
-->
echo command, for
if and elif, and to any program
invoked by the document.
Variable substitution is done within quoted strings in most cases where they may reasonably occur as an argument to an SSI directive. This includes the config, exec, flastmod, fsize, include, and set directives, as well as the arguments to conditional operators. You can insert a literal dollar sign into the string using backslash quoting:
<!--#if expr="$a = \$test" -->
If a variable reference needs to be substituted in the middle of a character sequence that might otherwise be considered a valid identifier in its own right, it can be disambiguated by enclosing the reference in braces, à la shell substitution:
<!--#set var="Zed" value="${REMOTE_HOST}_${REQUEST_METHOD}" -->
This will result in the Zed variable being set to "X_Y" if REMOTE_HOST is "X" and REQUEST_METHOD is "Y".
EXAMPLE: the below example will print "in foo" if the DOCUMENT_URI is /foo/file.html, "in bar" if it is /bar/file.html and "in neither" otherwise:
<!--#if expr="\"$DOCUMENT_URI\" = \"/foo/file.html\"" -->
in foo
<!--#elif expr="\"$DOCUMENT_URI\" = \"/bar/file.html\"" -->
in bar
<!--#else -->
in neither
<!--#endif -->
<!--#if expr="test_condition" -->
<!--#elif expr="test_condition" -->
<!--#else -->
<!--#endif -->
The if element works like an
if statement in a programming language. The test condition is
evaluated and if the result is true, then the text until the
next elif,
else. or
endif element is included in the
output stream.
The elif or
else statements are be used the
put text into the output stream if the original test_condition
was false. These elements are optional.
The endif element ends the
if element and is required.
test_condition is one of the following:
"=" and "!=" bind more tightly than "&&" and "||". "!" binds most tightly. Thus, the following are equivalent:
<!--#if expr="$a = test1 && $b = test2" -->
<!--#if expr="($a = test1) && ($b = test2)" -->
Anything that's not recognized as a variable or an operator is treated as a string. Strings can also be quoted: 'string'. Unquoted strings can't contain whitespace (blanks and tabs) because it is used to separate tokens such as variables. If multiple strings are found in a row, they are concatenated using blanks. So,
string1 string2 results in string1 string2
'string1 string2' results in string1 string2
XBitHack
offThe XBitHack directives controls the parsing of ordinary
html documents. This directive only affects files associated
with the MIME type text/html. XBitHack can take on
the following values:
on but also test the group-execute bit.
If it is set, then set the Last-modified date of the
returned file to be the last modified time of the file. If
it is not set, then no last-modified date is sent. Setting
this bit allows clients and proxies to cache the result of
the request.
Note: you would not want to use this,
for example, when you #include a CGI that
produces different output on each hit (or potentially
depends on the hit).