Enhanced documentation of variable substitution, and moved out (2c7e0ba7) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

docs/manual/mod/mod_include.html

+61 −43

Original line number	Diff line number	Diff line
		@@ -52,11 +52,14 @@ The document is parsed as an HTML document, with special commands embedded
		as SGML comments. A command has the syntax:

		<blockquote><code>
		<!--#</code><em>element attribute=value attribute=value ...</em> <code>-->
		<!--#</code><em>element attribute=value attribute=value ...</em>
		<code> -->
		</code></blockquote>

		The value will often be enclosed in double quotes; many commands only allow
		a single attribute-value pair.
		a single attribute-value pair. Note that the comment terminator
		(<SAMP>--></SAMP>) should be preceded by whitespace to ensure that it
		isn't considered part of an SSI token.
		<p>
		The allowed elements are:<p>

		@@ -189,9 +192,11 @@ For example:

		</dl>

		<h2>Include variables</h2>
		<h2>Include Variables</h2>

		In addition to the variables in the standard CGI environment, these are available for the <code>echo</code> command, for <code>if</code> and <code>elif</code>, and to any program invoked by the document.
		In addition to the variables in the standard CGI environment, these are
		available for the <code>echo</code> command, for <code>if</code> and
		<code>elif</code>, and to any program invoked by the document.

		<dl>
		<dt>DATE_GMT
		@@ -210,6 +215,51 @@ current document.
		</dl>
		<p>

		<H2>Variable Substitution</H2>
		<P> 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
		<SAMP>config</SAMP>,
		<SAMP>exec</SAMP>,
		<SAMP>flastmod</SAMP>,
		<SAMP>fsize</SAMP>,
		<SAMP>include</SAMP>, and
		<SAMP>set</SAMP>
		directives, as well as the arguments to conditional operators.
		You can insert a literal dollar sign into the string using backslash
		quoting:

		<PRE>
		<!--#if expr="$a = \$test" -->
		</PRE>

		<P> 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, <EM>à la</EM> shell substitution:

		<PRE>
		<!--#set var="Zed" value="${REMOTE_HOST}_${REQUEST_METHOD}" -->
		</PRE>

		<P> This will result in the <SAMP>Zed</SAMP> variable being set to
		"<SAMP>X_Y</SAMP>" if <SAMP>REMOTE_HOST</SAMP> is
		"<SAMP>X</SAMP>" and <SAMP>REQUEST_METHOD</SAMP> is
		"<SAMP>Y</SAMP>".

		<P> 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:
		<PRE>
		<!--#if expr="\"$DOCUMENT_URI\" = \"/foo/file.html\"" -->
		in foo
		<!--#elif expr="\"$DOCUMENT_URI\" = \"/bar/file.html\"" -->
		in bar
		<!--#else -->
		in neither
		<!--#endif -->
		</PRE>

		<H2>Flow Control Elements</H2>

		These are available in Apache 1.2 and above. The basic flow control
		@@ -256,12 +306,15 @@ elements are:
		<DT>! <I>test_condition</I>
		<DD>true if <I>test_condition</I> is false
		<DT><I>test_condition1</I> && <I>test_condition2</I>
		<DD>true if both <I>test_condition1</I> and <I>test_condition2</I> are true
		<DD>true if both <I>test_condition1</I> and
		<I>test_condition2</I> are true
		<DT><I>test_condition1</I> \|\| <I>test_condition2</I>
		<DD>true if either <I>test_condition1</I> or <I>test_condition2</I> is true
		<DD>true if either <I>test_condition1</I> or
		<I>test_condition2</I> is true
		</DL>

		<P> "<I>=</I>" and "<I>!=</I>" bind more tightly than "<I>&&</I>" and "<I>\|\|</I>".
		<P> "<I>=</I>" and "<I>!=</I>" bind more tightly than "<I>&&</I>" and
		"<I>\|\|</I>".
		"<I>!</I>" binds most tightly. Thus, the following are equivalent:

		<PRE>
		@@ -281,40 +334,6 @@ elements are:
		<I>'string1 string2'</I> results in <I>string1 string2</I>
		</PRE>

		<P> Variable substitution is done within quoted strings. You can put
		a dollar sign into the string using backslash quoting:

		<PRE>
		<!--#if expr="$a = \$test" -->
		</PRE>

		<P> If a variable reference needs to be substituted in the middle of a
		string, it can be done by enclosing the reference in braces,
		<EM>á la</EM> shell substitution:

		<PRE>
		<!--#set var="Zed" value="${REMOTE_HOST}_${REQUEST_METHOD}" -->
		</PRE>

		<P> will result in the <SAMP>Zed</SAMP> variable being set to
		"<SAMP>X_Y</SAMP>" if <SAMP>REMOTE_HOST</SAMP> is
		"<SAMP>X</SAMP>" and <SAMP>REQUEST_METHOD</SAMP> is
		"<SAMP>Y</SAMP>".

		<P> 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:
		<PRE>
		<!--#if expr="\"$DOCUMENT_URI\" = \"/foo/file.html\""-->
		in foo
		<!--#elif expr="\"$DOCUMENT_URI\" = \"/bar/file.html\""-->
		in bar
		<!--#else -->
		in neither
		<!--#endif -->
		</PRE>


		<hr>
		<h2>Directives</h2>
		<ul>
		@@ -357,4 +376,3 @@ the request.
		<!--#include virtual="footer.html" -->
		</BODY>
		</HTML>