| <?xml version="1.0"?> |
| <?xml-stylesheet type="text/xsl" href="../style/manual.xsl"?> |
| <modulesynopsis> |
| |
| <name>mod_setenvif</name> |
| <status>Base</status> |
| <identifier>setenvif_module</identifier> |
| <sourcefile>mod_setenvif.c</sourcefile> |
| <compatibility>Available in Apache 1.3 and later</compatibility> |
| |
| <description>Allows the setting of environment variables based |
| on characteristics of the request</description> |
| |
| <summary> |
| |
| <p>The <module>mod_setenvif</module> module allows you to set |
| environment variables according to whether different aspects of |
| the request match regular expressions you specify. These |
| environment variables can be used by other parts of the server |
| to make decisions about actions to be taken.</p> |
| |
| <p>The directives are considered in the order they appear in |
| the configuration files. So more complex sequences can be used, |
| such as this example, which sets <code>netscape</code> if the |
| browser is mozilla but not MSIE.</p> |
| |
| <example> |
| BrowserMatch ^Mozilla netscape<br /> |
| BrowserMatch MSIE !netscape<br /> |
| </example> |
| </summary> |
| |
| <seealso><a href="../env.html">Environment Variables in Apache</a></seealso> |
| |
| <directivesynopsis> |
| <name>BrowserMatch</name> |
| <description>Sets environment variables conditional on HTTP User-Agent |
| </description> |
| <syntax>BrowserMatch <em>regex env-variable</em>[=<em>value</em>] |
| [<em>env-variable</em>[=<em>value</em>]] ...</syntax> |
| <default><i>none</i></default> |
| <context>server config, virtual host, directory, .htaccess</context> |
| <override>FileInfo</override> |
| <compatibility>Apache 1.2 and |
| above (in Apache 1.2 this directive was found in the |
| now-obsolete mod_browser module)</compatibility> |
| |
| <usage> |
| <p>The <directive>BrowserMatch</directive> directive defines |
| environment variables based on the <code>User-Agent</code> HTTP |
| request header field. The first argument should be a POSIX.2 |
| extended regular expression (similar to an |
| <code>egrep</code>-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><code><em>varname</em></code>, or</li> |
| |
| <li><code>!<em>varname</em></code>, or</li> |
| |
| <li><code><em>varname</em>=<em>value</em></code></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 |
| <code><em>value</em></code>. If a <code>User-Agent</code> |
| 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> |
| <example> |
| BrowserMatch ^Mozilla forms jpeg=yes browser=netscape<br /> |
| BrowserMatch "^Mozilla/[2-3]" tables agif frames javascript<br /> |
| BrowserMatch MSIE !javascript<br /> |
| </example> |
| |
| <p>Note that the regular expression string is |
| <strong>case-sensitive</strong>. For case-INsensitive matching, |
| see the <directive |
| module="mod_setenvif">BrowserMatchNoCase</directive> |
| directive.</p> |
| |
| <p>The <directive>BrowserMatch</directive> and |
| <directive>BrowserMatchNoCase</directive> directives are special cases of |
| the <directive module="mod_setenvif">SetEnvIf</directive> and <directive |
| module="mod_setenvif">SetEnvIfNoCase</directive> |
| directives. The following two lines have the same effect:</p> |
| <example> |
| BrowserMatchNoCase Robot is_a_robot<br /> |
| SetEnvIfNoCase User-Agent Robot is_a_robot<br /> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>BrowserMatchNoCase</name> |
| <description>Sets environment variables conditional on User-Agent without |
| respect to case</description> |
| <syntax>BrowserMatchNoCase <em>regex env-variable</em>[=<em>value</em>] |
| [<em>env-variable</em>[=<em>value</em>]] ...</syntax> |
| <default><em>none</em></default> |
| <context>server config, virtual host, directory, .htaccess</context> |
| <override>FileInfo</override> |
| <compatibility>Apache 1.2 and |
| above (in Apache 1.2 this directive was found in the |
| now-obsolete mod_browser module)</compatibility> |
| |
| <usage> |
| |
| <p>The <directive>BrowserMatchNoCase</directive> directive is |
| semantically identical to the <directive |
| module="mod_setenvif">BrowserMatch</directive> directive. |
| However, it provides for case-insensitive matching. For |
| example:</p> |
| <example> |
| BrowserMatchNoCase mac platform=macintosh<br /> |
| BrowserMatchNoCase win platform=windows<br /> |
| </example> |
| |
| <p>The <directive>BrowserMatch</directive> and |
| <directive>BrowserMatchNoCase</directive> directives are special cases of |
| the <directive module="mod_setenvif">SetEnvIf</directive> and <directive |
| module="mod_setenvif">SetEnvIfNoCase</directive> |
| directives. The following two lines have the same effect:</p> |
| <example> |
| BrowserMatchNoCase Robot is_a_robot<br /> |
| SetEnvIfNoCase User-Agent Robot is_a_robot<br /> |
| </example> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>SetEnvIf</name> |
| <description>Sets environment variables based on attributes of the request |
| </description> |
| <syntax>SetEnvIf <em>attribute |
| regex env-variable</em>[=<em>value</em>] |
| [<em>env-variable</em>[=<em>value</em>]] ...</syntax> |
| <default><em>none</em></default> |
| <context> server config, virtual host, directory, .htaccess</context> |
| <override>FileInfo</override> |
| <compatibility>Apache 1.3 and |
| above; the Request_Protocol keyword and environment-variable |
| matching are only available with 1.3.7 and later</compatibility> |
| |
| <usage> |
| <p>The <directive>SetEnvIf</directive> 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://www.rfc-editor.org/rfc/rfc2616.txt">RFC2616</a> |
| for more information about these), or of other aspects of the |
| request, including the following:</p> |
| |
| <ul> |
| <li><code>Remote_Host</code> - the hostname (if available) of |
| the client making the request</li> |
| |
| <li><code>Remote_Addr</code> - the IP address of the client |
| making the request</li> |
| |
| <li><code>Remote_User</code> - the authenticated username (if |
| available)</li> |
| |
| <li><code>Request_Method</code> - the name of the method |
| being used (<code>GET</code>, <code>POST</code>, <em>et |
| cetera</em>)</li> |
| |
| <li><code>Request_Protocol</code> - the name and version of |
| the protocol with which the request was made (<em>e.g.</em>, |
| "HTTP/0.9", "HTTP/1.1", <em>etc.</em>)</li> |
| |
| <li><code>Request_URI</code> - 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 <code>Host</code>, <code>User-Agent</code>, and |
| <code>Referer</code>.</p> |
| |
| <p>If the <em>attribute</em> name doesn't match any of the |
| special keywords, nor any of the request's header field names, |
| it is tested as the name of an environment variable in the list |
| of those associated with the request. This allows |
| <directive>SetEnvIf</directive> directives to test against the result of |
| prior matches.</p> |
| |
| <note> |
| <strong>Only those environment variables defined by earlier |
| <code>SetEnvIf[NoCase]</code> directives are available for |
| testing in this manner. 'Earlier' means that they were |
| defined at a broader scope (such as server-wide) or |
| previously in the current directive's scope.</strong> |
| </note> |
| |
| <p><em>attribute</em> may be a regular expression when used to |
| match a request header. If <em>attribute</em> is a regular |
| expression and it doesn't match any of the request's header |
| names, then <em>attribute</em> is not tested against the |
| request's environment variable list.</p> |
| |
| <example> |
| <title>Example:</title> |
| SetEnvIf Request_URI "\.gif$" object_is_image=gif<br /> |
| SetEnvIf Request_URI "\.jpg$" object_is_image=jpg<br /> |
| SetEnvIf Request_URI "\.xbm$" object_is_image=xbm<br /> |
| :<br /> |
| SetEnvIf Referer www\.mydomain\.com intra_site_referral<br /> |
| :<br /> |
| SetEnvIf object_is_image xbm XBIT_PROCESSING=1<br /> |
| :<br /> |
| SetEnvIf ^TS* ^[a-z].* HAVE_TS<br /> |
| </example> |
| |
| <p>The first three will set the environment variable |
| <code>object_is_image</code> if the request was for an image |
| file, and the fourth sets <code>intra_site_referral</code> if |
| the referring page was somewhere on the |
| <code>www.mydomain.com</code> Web site.</p> |
| |
| <p>The last example will set environment variable |
| <code>HAVE_TS</code> if the request contains any headers that |
| begin with "TS" whose values begins with any character in the |
| set [a-z].</p> |
| </usage> |
| </directivesynopsis> |
| |
| <directivesynopsis> |
| <name>SetEnvIfNoCase</name> |
| <description>Sets environment variables based on attributes of the request |
| without respect to case</description> |
| <syntax>SetEnvIfNoCase <em>attribute regex env-variable</em>[=<em>value</em>] |
| [<em>env-variable</em>[=<em>value</em>]] ...</syntax> |
| <default><em>none</em></default> |
| <context>server config, virtual host, directory, .htaccess</context> |
| <override>FileInfo</override> |
| <compatibility>Apache 1.3 and above</compatibility> |
| |
| <usage> |
| |
| <p>The <directive>SetEnvIfNoCase</directive> is semantically identical to |
| the <directive module="mod_setenvif">SetEnvIf</directive> directive, |
| and differs only in that the regular expression matching is |
| performed in a case-insensitive manner. For example:</p> |
| <example> |
| SetEnvIfNoCase Host Apache\.Org site=apache |
| </example> |
| |
| <p>This will cause the <code>site</code> environment variable |
| to be set to "<code>apache</code>" if the HTTP request header |
| field <code>Host:</code> was included and contained |
| <code>Apache.Org</code>, <code>apache.org</code>, or any other |
| combination.</p> |
| </usage> |
| </directivesynopsis> |
| </modulesynopsis> |