Server Side Include pages
FPSTART
Server Side Include pages
REF
FPBODY
CrossLink supports an extended Apache 1.3 Server Side Include language, including a hit counter.
The first thing you have to do is adjust the filename extension of your web page so that the server recognizes it as containing server-side includes. Just change the extension to .shtml. So, for instance, if your web page was named "index.html" or "index.htm", your new web page should be named "index.shtml".
The document is parsed as an HTML document, with special commands embedded as SGML comments. A command has the syntax:
element attribute=value attribute=value ...
<!--#
-->
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.
The allowed elements are:
<!--#config errmsg="oops" sizefmt="bytes|abbrev"
timefmt="" -->
bytes
for a count in bytes, or abbrev
for a count in Kb or
Mb as appropriate.strftime(3)
library routine when
printing dates.<!--#coutnter -->
<!--#echo var="LAST_MODIFIED"
-->
(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.<!--#exec cgi="runme.cgi" -->
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.
For example:
<!--#exec cgi="/cgi-bin/example.cgi" -->
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
. In particular, if you need to pass additional
arguments to a CGI program, using the query string, this cannot be done with exec
cgi
, but can be done with include virtual
, as shown here:
<!--#include virtual="/cgi-bin/example.cgi?argument=value" -->
<!--#fsize file="index.html" -->
sizefmt
format specification. Attributes: <!--#flastmod file="index.html" -->
timefmt
format specification. The attributes are the same as for the fsize
command.<!--#include virtual="index.html" -->
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. Therefore, you
cannot include files that are outside of the document root, or above the current document
in the directory structure. The virtual
attribute should always be used in
preference to this one.A URL is constructed from the attribute, and the output the server would return if the URL were accessed by the client is included in the parsed output. Thus included files can be nested.
If the specified URL is a CGI program, the program will be executed and its output inserted in place of the directive in the parsed file. You may include a query string in a CGI url:
<!--#include virtual="/cgi-bin/example.cgi?argument=value" -->
include virtual
should be used in preference to exec cgi
to
include the output of CGI programs into an HTML document.
<!--#printenv -->
echo
element for details) before being output. There are no attributes.For example:
<!--#printenv -->
The printenv element is available only in Apache 1.2 and above.
<!--#set var="foo" value="bar" -->
For example: <!--#set var="category" value="help" -->
You may also substitute environment variables in the value, such as:
<!--#set var="Zed"
value="${REMOTE_ADDR}_${REQUEST_METHOD}" -->
See Variable Substition for more details.
Set may also be used capture a CGI variable if the Server Side Include page is accessed as if it were a GET method CGI program. For example, if you used the URL:
http://www.examplecompany.com/ssi.shtml?foo=bar&i=am
Then you can capture the CGI variable "foo" with:
<!--#set var="ssifoo" query="foo" -->
The variable "ssifoo" will be set to "bar".
In addition to the variables in the standard CGI environment, these are available for
the 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="\"$DOCUMENT_URI\" = \"/bar/file.html\"" --> in bar <!--#else --> in neither <!--#endif -->
The basic flow control elements are:
<!--#if expr="test_condition" --> <!--#elif expr="test_condition" --> <!--#else --> <!--#endif -->
The if
element works like an if statement in a
programming language. The test condition is evaluated and if the result is true, then the
text until the next elif
, else
.
or endif
element is included in the output stream.
The elif
or else
statements
are be used the put text into the output stream if the original test_condition was false.
These elements are optional.
The endif
element ends the if
element and is required.
test_condition is one of the following:
"=" and "!=" bind more tightly than "&&" and "||". "!" binds most tightly. Thus, the following are equivalent:
<!--#if expr="$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
There is a document which describes how to use the features of mod_include to offer internationalized customized server error documents.
FPEND