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   <H1 ALIGN="CENTER">Module mod_setenvif</H1>
   <P>
   This module is contained in the <SAMP>mod_setenvif.c</SAMP> file, and
   <STRONG>is</STRONG> compiled in by default. It provides for
   the ability to set environment variables based upon attributes of the
   request.
   </P>
   <H2>Summary</H2>
   <P>
   The <SAMP>mod_setenvif</SAMP> module allows you to set environment
   variables according to whether different aspects of the request match
   regular expressions you specify.  These envariables can be used by
   other parts of the server to make decisions about actions to be taken.
   </P>
   <H2>Directives</H2>
   <UL>
    <LI><A HREF="#BrowserMatch">BrowserMatch</A>
    </LI>
    <LI><A HREF="#BrowserMatchNoCase">BrowserMatchNoCase</A>
    </LI>
    <LI><A HREF="#SetEnvIf">SetEnvIf</A>
    </LI>
    <LI><A HREF="#SetEnvIfNoCase">SetEnvIfNoCase</A>
    </LI>
   </UL>

   <HR> <!-- the HR is part of the directive description -->
   <H2><A NAME="BrowserMatch">The <SAMP>BrowserMatch</SAMP> Directive</A></H2>
   <P>
   <STRONG>Syntax:</STRONG> BrowserMatch <EM>regex envar[=value] [...]</EM>
   <BR>
   <STRONG>Default:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Context:</STRONG> server config
   <BR>
   <STRONG>Override:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Status:</STRONG> Base
   <BR>
   <STRONG>Module:</STRONG> mod_setenvif
   <BR>
   <STRONG>Compatibility:</STRONG> Apache 1.2 and above
   </P>
   <P>
   The BrowserMatch directive defines environment variables based on the
   <SAMP>User-Agent</SAMP> HTTP request header field. The first argument
   should be a POSIX.2 extended regular expression (similar to an
   <SAMP>egrep</SAMP>-style regex).  The rest of the arguments give the
   names of variables to set, and optionally values to which they should
   be set. These take the form of
   </P>
   <OL>
    <LI><SAMP><EM>varname</EM></SAMP>, or
    </LI>
    <LI><SAMP>!<EM>varname</EM></SAMP>, or
    </LI>
    <LI><SAMP><EM>varname</EM>=<EM>value</EM></SAMP>
    </LI>
   </OL>
   <P>
   In the first form, the value will be set to &quot;1&quot;. The second
   will remove the given variable if already defined, and the third will
   set the variable to the value given by <SAMP><EM>value</EM></SAMP>. If a
   <SAMP>User-Agent</SAMP> string matches more than one entry, they will
   be merged.  Entries are processed in the order in which they appear,
   and later entries can override earlier ones.
   </P>
   <P>
   For example:
   </P>
   <PRE>
     BrowserMatch ^Mozilla forms jpeg=yes browser=netscape
     BrowserMatch "^Mozilla/[2-3]" tables agif frames javascript
     BrowserMatch MSIE !javascript
   </PRE>
   <P>
   Note that the regular expression string is
   <STRONG>case-sensitive</STRONG>.  For cane-INsensitive matching, see
   the
   <A
    HREF="#BrowserMatchNoCase"
   ><SAMP>BrowserMatchNoCase</SAMP></A>
   directive.
   </P>
   <P>
   The <SAMP>BrowserMatch</SAMP> and <SAMP>BrowserMatchNoCase</SAMP>
   directives are special cases of the
   <A
    HREF="#SetEnvIf"
   ><SAMP>SetEnvIf</SAMP></A>
   and
   <A
    HREF="#SetEnvIfNoCase"
   ><SAMP>SetEnvIfNoCase</SAMP></A>
   directives.  The following two lines have the same effect:
   </P>
   <PRE>
    BrowserMatchNoCase Robot is_a_robot
    SetEnvIfNoCase User-Agent Robot is_a_robot
   </PRE>

   <HR> <!-- the HR is part of the directive description -->
   <H2>
    <A NAME="BrowserMatchNoCase">
     The <SAMP>BrowserMatchNoCase</SAMP> Directive
    </A>
   </H2>
   <P>
   <STRONG>Syntax:</STRONG> BrowserMatchNoCase <EM>regex envar[=value] [...]</EM>
   <BR>
   <STRONG>Default:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Context:</STRONG> server config
   <BR>
   <STRONG>Override:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Status:</STRONG> Base
   <BR>
   <STRONG>Module:</STRONG> mod_setenvif
   <BR>
   <STRONG>Compatibility:</STRONG> Apache 1.2 and above
   </P>
   <P>
   The <SAMP>BrowserMatchNoCase</SAMP> directive is semantically identical to
   the
   <A
    HREF="#BrowserMatch"
   ><SAMP>BrowserMatch</SAMP></A>
   directive. However, it provides for case-insensitive matching. For
   example:
   </P>
   <PRE>
     BrowserMatchNoCase mac platform=macintosh
     BrowserMatchNoCase win platform=windows
   </PRE>
   <P>
   The <SAMP>BrowserMatch</SAMP> and <SAMP>BrowserMatchNoCase</SAMP>
   directives are special cases of the
   <A
    HREF="#SetEnvIf"
   ><SAMP>SetEnvIf</SAMP></A>
   and
   <A
    HREF="#SetEnvIfNoCase"
   ><SAMP>SetEnvIfNoCase</SAMP></A>
   directives.  The following two lines have the same effect:
   </P>
   <PRE>
    BrowserMatchNoCase Robot is_a_robot
    SetEnvIfNoCase User-Agent Robot is_a_robot
   </PRE>

   <HR> <!-- the HR is part of the directive description -->
   <H2>
    <A NAME="SetEnvIf">
     The <SAMP>SetEnvIf</SAMP> Directive
    </A>
   </H2>
   <P>
   <STRONG>Syntax:</STRONG> SetEnvIf <EM> attribute regex envar[=value] [...]</EM>
   <BR>
   <STRONG>Default:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Context:</STRONG> server config
   <BR>
   <STRONG>Override:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Status:</STRONG> Base
   <BR>
   <STRONG>Module:</STRONG> mod_setenvif
   <BR>
   <STRONG>Compatibility:</STRONG> Apache 1.3 and above
   </P>
   <P>
   The <SAMP>SetEnvIf</SAMP> directive defines environment variables
   based on attributes of the request.  These attributes can be the
   values of various HTTP request header fields (see
   <A
    HREF="http://ds.internic.net/rfc/rfc2068.txt"
   >RFC2068</A>
   for more information about these), or of other aspects of the request,
   including the following:
   </P>
   <UL>
    <LI><SAMP>Remote_Host</SAMP> - the hostname (if available) of the
     client making the request
    </LI>
    <LI><SAMP>Remote_Addr</SAMP> - the IP address of the client making
     the request
    </LI>
    <LI><SAMP>Remote_User</SAMP> - the authenticated username (if
     available)
    </LI>
    <LI><SAMP>Request_Method</SAMP> - the name of the method being used
     (<SAMP>GET</SAMP>, <SAMP>POST</SAMP>, <EM>et cetera</EM>)
    </LI>
    <LI><SAMP>Request_URI</SAMP> - the portion of the URL following the
     scheme and host portion
    </LI>
   </UL>
   <P>
   Some of the more commonly used request header field names include
   <SAMP>Host</SAMP>, <SAMP>User-Agent</SAMP>, and <SAMP>Referer</SAMP>.
   </P>
   <P>
   Example:
   </P>
   <PRE>
    SetEnvIf Request_URI "\.(gif)|(jpg)|(xbm)$" object_is_image
    SetEnvIf Referer www\.mydomain\.com intra_site_referral
   </PRE>
   <P>
   The first will set the envariable <SAMP>object_is_image</SAMP> if the
   request was for an image file, and the second sets
   <SAMP>intra_site_referral</SAMP> if the referring page was somewhere
   on the <SAMP>www.mydomain.com</SAMP> Web site.
   </P>

   <HR> <!-- the HR is part of the directive description -->
   <H2>
    <A NAME="SetEnvIfNoCase">
     The <SAMP>SetEnvIfNoCase</SAMP> Directive
    </A>
   </H2>
   <P>
   <STRONG>Syntax:</STRONG> SetEnvIfNoCase
    <EM> attribute regex envar[=value] [...]</EM>
   <BR>
   <STRONG>Default:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Context:</STRONG> server config
   <BR>
   <STRONG>Override:</STRONG> <EM>none</EM>
   <BR>
   <STRONG>Status:</STRONG> Base
   <BR>
   <STRONG>Module:</STRONG> mod_setenvif
   <BR>
   <STRONG>Compatibility:</STRONG> Apache 1.3 and above
   </P>
   <P>
   The <SAMP>SetEnvIfNoCase</SAMP> is semantically identical to the
   <A
    HREF="#SetEnvIf"
   ><SAMP>SetEnvIf</SAMP></A>
   directive, and differs only in that the regular expression matching is
   performed in a case-insensitive manner. For example:
   </P>
   <PRE>
    SetEnvIfNoCase Host Apache\.Org site=apache
   </PRE>
   <P>
   This will cause the <SAMP>site</SAMP> envariable to be set to
   &quot;<SAMP>apache</SAMP>&quot; if the HTTP request header field
   <SAMP>Host:</SAMP> was included and contained <SAMP>Apache.Org</SAMP>,
   <SAMP>apache.org</SAMP>, or any other combination.
   </P>

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	<H1 ALIGN="CENTER">Module mod_setenvif</H1>
	<P>
	This module is contained in the <SAMP>mod_setenvif.c</SAMP> file, and
	<STRONG>is</STRONG> compiled in by default. It provides for
	the ability to set environment variables based upon attributes of the
	request.
	</P>
	<H2>Summary</H2>
	<P>
	The <SAMP>mod_setenvif</SAMP> module allows you to set environment
	variables according to whether different aspects of the request match
	regular expressions you specify. These envariables can be used by
	other parts of the server to make decisions about actions to be taken.
	</P>
	<H2>Directives</H2>
	<UL>
	<LI><A HREF="#BrowserMatch">BrowserMatch</A>
	</LI>
	<LI><A HREF="#BrowserMatchNoCase">BrowserMatchNoCase</A>
	</LI>
	<LI><A HREF="#SetEnvIf">SetEnvIf</A>
	</LI>
	<LI><A HREF="#SetEnvIfNoCase">SetEnvIfNoCase</A>
	</LI>
	</UL>

	<HR> <!-- the HR is part of the directive description -->
	<H2><A NAME="BrowserMatch">The <SAMP>BrowserMatch</SAMP> Directive</A></H2>
	<P>
	<STRONG>Syntax:</STRONG> BrowserMatch <EM>regex envar[=value] [...]</EM>
	<BR>
	<STRONG>Default:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Context:</STRONG> server config
	<BR>
	<STRONG>Override:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Status:</STRONG> Base
	<BR>
	<STRONG>Module:</STRONG> mod_setenvif
	<BR>
	<STRONG>Compatibility:</STRONG> Apache 1.2 and above
	</P>
	<P>
	The BrowserMatch directive defines environment variables based on the
	<SAMP>User-Agent</SAMP> HTTP request header field. The first argument
	should be a POSIX.2 extended regular expression (similar to an
	<SAMP>egrep</SAMP>-style regex). The rest of the arguments give the
	names of variables to set, and optionally values to which they should
	be set. These take the form of
	</P>
	<OL>
	<LI><SAMP><EM>varname</EM></SAMP>, or
	</LI>
	<LI><SAMP>!<EM>varname</EM></SAMP>, or
	</LI>
	<LI><SAMP><EM>varname</EM>=<EM>value</EM></SAMP>
	</LI>
	</OL>
	<P>
	In the first form, the value will be set to "1". The second
	will remove the given variable if already defined, and the third will
	set the variable to the value given by <SAMP><EM>value</EM></SAMP>. If a
	<SAMP>User-Agent</SAMP> string matches more than one entry, they will
	be merged. Entries are processed in the order in which they appear,
	and later entries can override earlier ones.
	</P>
	<P>
	For example:
	</P>
	<PRE>
	BrowserMatch ^Mozilla forms jpeg=yes browser=netscape
	BrowserMatch "^Mozilla/[2-3]" tables agif frames javascript
	BrowserMatch MSIE !javascript
	</PRE>
	<P>
	Note that the regular expression string is
	<STRONG>case-sensitive</STRONG>. For cane-INsensitive matching, see
	the
	<A
	HREF="#BrowserMatchNoCase"
	><SAMP>BrowserMatchNoCase</SAMP></A>
	directive.
	</P>
	<P>
	The <SAMP>BrowserMatch</SAMP> and <SAMP>BrowserMatchNoCase</SAMP>
	directives are special cases of the
	<A
	HREF="#SetEnvIf"
	><SAMP>SetEnvIf</SAMP></A>
	and
	<A
	HREF="#SetEnvIfNoCase"
	><SAMP>SetEnvIfNoCase</SAMP></A>
	directives. The following two lines have the same effect:
	</P>
	<PRE>
	BrowserMatchNoCase Robot is_a_robot
	SetEnvIfNoCase User-Agent Robot is_a_robot
	</PRE>

	<HR> <!-- the HR is part of the directive description -->
	<H2>
	<A NAME="BrowserMatchNoCase">
	The <SAMP>BrowserMatchNoCase</SAMP> Directive
	</A>
	</H2>
	<P>
	<STRONG>Syntax:</STRONG> BrowserMatchNoCase <EM>regex envar[=value] [...]</EM>
	<BR>
	<STRONG>Default:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Context:</STRONG> server config
	<BR>
	<STRONG>Override:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Status:</STRONG> Base
	<BR>
	<STRONG>Module:</STRONG> mod_setenvif
	<BR>
	<STRONG>Compatibility:</STRONG> Apache 1.2 and above
	</P>
	<P>
	The <SAMP>BrowserMatchNoCase</SAMP> directive is semantically identical to
	the
	<A
	HREF="#BrowserMatch"
	><SAMP>BrowserMatch</SAMP></A>
	directive. However, it provides for case-insensitive matching. For
	example:
	</P>
	<PRE>
	BrowserMatchNoCase mac platform=macintosh
	BrowserMatchNoCase win platform=windows
	</PRE>
	<P>
	The <SAMP>BrowserMatch</SAMP> and <SAMP>BrowserMatchNoCase</SAMP>
	directives are special cases of the
	<A
	HREF="#SetEnvIf"
	><SAMP>SetEnvIf</SAMP></A>
	and
	<A
	HREF="#SetEnvIfNoCase"
	><SAMP>SetEnvIfNoCase</SAMP></A>
	directives. The following two lines have the same effect:
	</P>
	<PRE>
	BrowserMatchNoCase Robot is_a_robot
	SetEnvIfNoCase User-Agent Robot is_a_robot
	</PRE>

	<HR> <!-- the HR is part of the directive description -->
	<H2>
	<A NAME="SetEnvIf">
	The <SAMP>SetEnvIf</SAMP> Directive
	</A>
	</H2>
	<P>
	<STRONG>Syntax:</STRONG> SetEnvIf <EM> attribute regex envar[=value] [...]</EM>
	<BR>
	<STRONG>Default:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Context:</STRONG> server config
	<BR>
	<STRONG>Override:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Status:</STRONG> Base
	<BR>
	<STRONG>Module:</STRONG> mod_setenvif
	<BR>
	<STRONG>Compatibility:</STRONG> Apache 1.3 and above
	</P>
	<P>
	The <SAMP>SetEnvIf</SAMP> directive defines environment variables
	based on attributes of the request. These attributes can be the
	values of various HTTP request header fields (see
	<A
	HREF="http://ds.internic.net/rfc/rfc2068.txt"
	>RFC2068</A>
	for more information about these), or of other aspects of the request,
	including the following:
	</P>
	<UL>
	<LI><SAMP>Remote_Host</SAMP> - the hostname (if available) of the
	client making the request
	</LI>
	<LI><SAMP>Remote_Addr</SAMP> - the IP address of the client making
	the request
	</LI>
	<LI><SAMP>Remote_User</SAMP> - the authenticated username (if
	available)
	</LI>
	<LI><SAMP>Request_Method</SAMP> - the name of the method being used
	(<SAMP>GET</SAMP>, <SAMP>POST</SAMP>, <EM>et cetera</EM>)
	</LI>
	<LI><SAMP>Request_URI</SAMP> - the portion of the URL following the
	scheme and host portion
	</LI>
	</UL>
	<P>
	Some of the more commonly used request header field names include
	<SAMP>Host</SAMP>, <SAMP>User-Agent</SAMP>, and <SAMP>Referer</SAMP>.
	</P>
	<P>
	Example:
	</P>
	<PRE>
	SetEnvIf Request_URI "\.(gif)\|(jpg)\|(xbm)$" object_is_image
	SetEnvIf Referer www\.mydomain\.com intra_site_referral
	</PRE>
	<P>
	The first will set the envariable <SAMP>object_is_image</SAMP> if the
	request was for an image file, and the second sets
	<SAMP>intra_site_referral</SAMP> if the referring page was somewhere
	on the <SAMP>www.mydomain.com</SAMP> Web site.
	</P>

	<HR> <!-- the HR is part of the directive description -->
	<H2>
	<A NAME="SetEnvIfNoCase">
	The <SAMP>SetEnvIfNoCase</SAMP> Directive
	</A>
	</H2>
	<P>
	<STRONG>Syntax:</STRONG> SetEnvIfNoCase
	<EM> attribute regex envar[=value] [...]</EM>
	<BR>
	<STRONG>Default:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Context:</STRONG> server config
	<BR>
	<STRONG>Override:</STRONG> <EM>none</EM>
	<BR>
	<STRONG>Status:</STRONG> Base
	<BR>
	<STRONG>Module:</STRONG> mod_setenvif
	<BR>
	<STRONG>Compatibility:</STRONG> Apache 1.3 and above
	</P>
	<P>
	The <SAMP>SetEnvIfNoCase</SAMP> is semantically identical to the
	<A
	HREF="#SetEnvIf"
	><SAMP>SetEnvIf</SAMP></A>
	directive, and differs only in that the regular expression matching is
	performed in a case-insensitive manner. For example:
	</P>
	<PRE>
	SetEnvIfNoCase Host Apache\.Org site=apache
	</PRE>
	<P>
	This will cause the <SAMP>site</SAMP> envariable to be set to
	"<SAMP>apache</SAMP>" if the HTTP request header field
	<SAMP>Host:</SAMP> was included and contained <SAMP>Apache.Org</SAMP>,
	<SAMP>apache.org</SAMP>, or any other combination.
	</P>

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