mod_alias.xml revision 7db9f691a00ead175b03335457ca296a33ddf31b
<?xml version="1.0"?>
<!DOCTYPE modulesynopsis SYSTEM "/style/modulesynopsis.dtd">
<?xml-stylesheet type="text/xsl" href="/style/manual.en.xsl"?>
<modulesynopsis metafile="mod_alias.xml.meta">
<name>mod_alias</name>
<description>Provides for mapping different parts of the host
filesystem in the document tree and for URL redirection</description>
<status>Base</status>
<sourcefile>mod_alias.c</sourcefile>
<identifier>alias_module</identifier>
<summary>
<p>The directives contained in this module allow for manipulation
and control of URLs as requests arrive at the server. The
<directive module="mod_alias">Alias</directive> and <directive
module="mod_alias">ScriptAlias</directive> directives are used to
map between URLs and filesystem paths. This allows for content
which is not directly under the <directive
module="core">DocumentRoot</directive> served as part of the web
document tree. The <directive
module="mod_alias">ScriptAlias</directive> directive has the
additional effect of marking the target directory as containing
only CGI scripts.</p>
<p>The <directive module="mod_alias">Redirect</directive>
directives are used to instruct clients to make a new request with
a different URL. They are often used when a resource has moved to
a new location.</p>
</summary>
<seealso><module>mod_rewrite</module></seealso> <seealso><a
href="/urlmapping.html">Mapping URLs to the filesystem</a></seealso>
<directivesynopsis>
<name>Alias</name>
<description>Maps URLs to filesystem locations</description>
<syntax>Alias <var>URL-path</var>
<var>file-path</var>|<var>directory-path</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
</contextlist>
<usage>
<p>The <directive>Alias</directive> directive allows documents to
be stored in the local filesystem other than under the
<directive module="core">DocumentRoot</directive>. URLs with a
(%-decoded) path beginning with <var>url-path</var> will be mapped
to local files beginning with <var>directory-path</var>.</p>
<example><title>Example:</title>
Alias /image /ftp/pub/image
</example>
<p>A request for http://myserver/image/foo.gif would cause the
server to return the file /ftp/pub/image/foo.gif.</p>
<p>Note that if you include a trailing / on the
<var>url-path</var> then the server will require a trailing / in
order to expand the alias. That is, if you use <code>Alias
/icons/ /usr/local/apache/icons/</code> then the url
<code>/icons</code> will not be aliased.</p>
<p>Note that you may need to specify additional <directive
type="section" module="core">Directory</directive> sections which
cover the <em>destination</em> of aliases. Aliasing occurs before
<directive type="section" module="core">Directory</directive> sections
are checked, so only the destination of aliases are affected.
(Note however <directive type="section" module="core">Location</directive>
sections are run through once before aliases are performed, so
they will apply.)</p>
<p>In particular, if you are creating an <code>Alias</code> to a
directory outside of your <directive
module="code">DocumentRoot</directive>, you may need to explicitly
permit access to the target directory.</p>
<example><title>Example:</title>
Alias /image /ftp/pub/image<br />
&lt;Directory /ftp/pub/image&gt;<br />
<indent>
Order allow,deny<br />
Allow from all<br />
</indent>
&lt;/Directory&gt;
</example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>AliasMatch</name>
<description>Maps URLs to filesystem locations using regular
expressions</description>
<syntax>AliasMatch <var>regex</var>
<var>file-path</var>|<var>directory-path</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
</contextlist>
<usage>
<p>This directive is equivalent to <directive
module="mod_alias">Alias</directive>, but makes use of standard
regular expressions, instead of simple prefix matching. The
supplied regular expression is matched against the URL-path, and
if it matches, the server will substitute any parenthesized
matches into the given string and use it as a filename. For
example, to activate the <code>/icons</code> directory, one might
use:</p>
<example>
AliasMatch ^/icons(.*) /usr/local/apache/icons$1
</example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>Redirect</name>
<description>Sends an external redirect asking the client to fetch
a different URL</description>
<syntax>Redirect [<var>status</var>] <var>URL-path</var>
<var>URL</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>The Redirect directive maps an old URL into a new one. The
new URL is returned to the client which attempts to fetch it
again with the new address. <var>URL-path</var> a (%-decoded)
path; any requests for documents beginning with this path will
be returned a redirect error to a new (%-encoded) URL beginning
with <var>URL</var>.</p>
<example><title>Example:</title>
Redirect /service http://foo2.bar.com/service
</example>
<p>If the client requests http://myserver/service/foo.txt, it
will be told to access http://foo2.bar.com/service/foo.txt
instead.</p>
<note><title>Note</title> <p>Redirect directives take precedence over
Alias and ScriptAlias directives, irrespective of their ordering in
the configuration file. Also, <var>URL-path</var> must be an absolute
path, not a relative path, even when used with .htaccess files or
inside of <directive type="section" module="core">Directory</directive>
sections.</p></note>
<p>If no <var>status</var> argument is given, the redirect will
be "temporary" (HTTP status 302). This indicates to the client
that the resource has moved temporarily. The <var>status</var>
argument can be used to return other HTTP status codes:</p>
<dl>
<dt>permanent</dt>
<dd>Returns a permanent redirect status (301) indicating that
the resource has moved permanently.</dd>
<dt>temp</dt>
<dd>Returns a temporary redirect status (302). This is the
default.</dd>
<dt>seeother</dt>
<dd>Returns a "See Other" status (303) indicating that the
resource has been replaced.</dd>
<dt>gone</dt>
<dd>Returns a "Gone" status (410) indicating that the
resource has been permanently removed. When this status is
used the <var>URL</var> argument should be omitted.</dd>
</dl>
<p>Other status codes can be returned by giving the numeric
status code as the value of <var>status</var>. If the status is
between 300 and 399, the <var>URL</var> argument must be present,
otherwise it must be omitted. Note that the status must be
known to the Apache code (see the function
<code>send_error_response</code> in http_protocol.c).</p>
<example><title>Example:</title>
Redirect permanent /one http://example.com/two<br />
Redirect 303 /three http://example.com/other
</example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>RedirectMatch</name>
<description>Sends an external redirect based on a regular expression match
of the current URL</description>
<syntax>RedirectMatch [<var>status</var>] <var>regex</var>
<var>URL</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>This directive is equivalent to <directive
module="mod_alias">Redirect</directive>, but makes use of standard
regular expressions, instead of simple prefix matching. The
supplied regular expression is matched against the URL-path, and
if it matches, the server will substitute any parenthesized
matches into the given string and use it as a filename. For
example, to redirect all GIF files to like-named JPEG files on
another server, one might use:</p>
<example>
RedirectMatch (.*)\.gif$ http://www.anotherserver.com$1.jpg
</example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>RedirectTemp</name>
<description>Sends an external temporary redirect asking the client to fetch
a different URL</description>
<syntax>RedirectTemp <var>URL-path</var> <var>URL</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>This directive makes the client know that the Redirect is
only temporary (status 302). Exactly equivalent to
<code>Redirect temp</code>.</p>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>RedirectPermanent</name>
<description>Sends an external permanent redirect asking the client to fetch
a different URL</description>
<syntax>RedirectPermanent <var>URL-path</var> <var>URL</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>This directive makes the client know that the Redirect is
permanent (status 301). Exactly equivalent to <code>Redirect
permanent</code>.</p>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>ScriptAlias</name>
<description>Maps a URL to a filesystem location and designates the
target as a CGI script</description>
<syntax>ScriptAlias <var>URL-path</var>
<var>file-path</var>|<var>directory-path</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
</contextlist>
<usage>
<p>The <directive>ScriptAlias</directive> directive has the same
behavior as the <directive module="mod_alias">Alias</directive>
directive, except that in addition it marks the target directory
as containing CGI scripts that will be processed by <module
>mod_cgi</module>'s cgi-script handler. URLs with a
(%-decoded) path beginning with <var>URL-path</var> will be mapped
to scripts beginning with the second argument which is a full
pathname in the local filesystem.</p>
<example><title>Example:</title>
ScriptAlias /cgi-bin/ /web/cgi-bin/
</example>
<p>A request for <code>http://myserver/cgi-bin/foo</code> would cause the
server to run the script <code>/web/cgi-bin/foo</code>.</p>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>ScriptAliasMatch</name>
<description>Maps a URL to a filesystem location using a regular expression
and designates the target as a CGI script</description>
<syntax>ScriptAliasMatch <var>regex</var>
<var>file-path</var>|<var>directory-path</var></syntax>
<contextlist><context>server config</context><context>virtual host</context>
</contextlist>
<usage>
<p>This directive is equivalent to <directive module="mod_alias"
>ScriptAlias</directive>, but makes use of standard
regular expressions, instead of simple prefix matching. The
supplied regular expression is matched against the URL-path,
and if it matches, the server will substitute any parenthesized
matches into the given string and use it as a filename. For
example, to activate the standard <code>/cgi-bin</code>, one
might use:</p>
<example>
ScriptAliasMatch ^/cgi-bin(.*) /usr/local/apache/cgi-bin$1
</example>
</usage>
</directivesynopsis>
</modulesynopsis>