Apache HTTP Server Version 2.2
Apache Module mod_dir
Description: | Provides for "trailing slash" redirects and serving directory index files |
---|---|
Status: | Base |
Module Identifier: | dir_module |
Source File: | mod_dir.c |
Summary
The index of a directory can come from one of two sources:
- A file written by the user, typically called
index.html
. TheDirectoryIndex
directive sets the name of this file. This is controlled bymod_dir
. - Otherwise, a listing generated by the server. This is
provided by
mod_autoindex
.
The two functions are separated so that you can completely remove (or replace) automatic index generation should you want to.
A "trailing slash" redirect is issued when the server
receives a request for a URL
http://servername/foo/dirname
where
dirname
is a directory. Directories require a
trailing slash, so mod_dir
issues a redirect to
http://servername/foo/dirname/
.
DirectoryIndex Directive
Description: | List of resources to look for when the client requests a directory |
---|---|
Syntax: | DirectoryIndex
local-url [local-url] ... |
Default: | DirectoryIndex index.html |
Context: | server config, virtual host, directory, .htaccess |
Override: | Indexes |
Status: | Base |
Module: | mod_dir |
The DirectoryIndex
directive sets the
list of resources to look for, when the client requests an index
of the directory by specifying a / at the end of the directory
name. Local-url is the (%-encoded) URL of a document on
the server relative to the requested directory; it is usually the
name of a file in the directory. Several URLs may be given, in
which case the server will return the first one that it finds. If
none of the resources exist and the Indexes
option is
set, the server will generate its own listing of the
directory.
Example
DirectoryIndex index.html
then a request for http://example.com/docs/
would
return http://example.com/docs/index.html
if it
exists, or would list the directory if it did not.
Note that the documents do not need to be relative to the directory;
DirectoryIndex index.html index.txt /cgi-bin/index.pl
would cause the CGI script /cgi-bin/index.pl
to be
executed if neither index.html
or index.txt
existed in a directory.
Note: Multiple DirectoryIndex
directives within the same context will add
to the list of resources to look for rather than replace:
# Example A: Set index.html as an index page, then add index.php to that list as well. <Directory /foo> DirectoryIndex index.html DirectoryIndex index.php </Directory> # Example B: This is identical to example A, except it's done with a single directive. <Directory /foo> DirectoryIndex index.html index.php </Directory>
DirectorySlash Directive
Description: | Toggle trailing slash redirects on or off |
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Syntax: | DirectorySlash On|Off |
Default: | DirectorySlash On |
Context: | server config, virtual host, directory, .htaccess |
Override: | Indexes |
Status: | Base |
Module: | mod_dir |
Compatibility: | Available in version 2.0.51 and later |
The DirectorySlash
directive determines whether
mod_dir
should fixup URLs pointing to a directory or
not.
Typically if a user requests a resource without a trailing slash, which
points to a directory, mod_dir
redirects him to the same
resource, but with trailing slash for some good reasons:
- The user is finally requesting the canonical URL of the resource
mod_autoindex
works correctly. Since it doesn't emit the path in the link, it would point to the wrong path.DirectoryIndex
will be evaluated only for directories requested with trailing slash.- Relative URL references inside html pages will work correctly.
If you don't want this effect and the reasons above don't apply to you, you can turn off the redirect as shown below. However, be aware that there are possible security implications to doing this.
# see security warning below!
<Location /some/path>
DirectorySlash Off
SetHandler some-handler
</Location>
Security Warning
Turning off the trailing slash redirect may result in an information
disclosure. Consider a situation where mod_autoindex
is
active (Options +Indexes
) and DirectoryIndex
is set to a valid resource (say,
index.html
) and there's no other special handler defined for
that URL. In this case a request with a trailing slash would show the
index.html
file. But a request without trailing slash
would list the directory contents.
FallbackResource Directive
Description: | Define a default URL for requests that don't map to a file |
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Syntax: | FallbackResource disabled | local-url |
Default: | None - httpd will return 404 (Not Found) |
Context: | server config, virtual host, directory, .htaccess |
Override: | Indexes |
Status: | Base |
Module: | mod_dir |
Compatibility: | Apache HTTP Server 2.2.16 and later - The disabled argument
is supported since 2.2.24 |
Use this to set a handler for any URL that doesn't map to anything in your filesystem, and would otherwise return HTTP 404 (Not Found). For example
FallbackResource /not-404.php
will cause requests for non-existent files to be handled by
not-404.php
, while requests for files that exist
are unaffected.
It is frequently desirable to have a single file or resource handle all requests to a particular directory, except those requests that correspond to an existing file or script. This is often referred to as a 'front controller.'
In earlier versions of httpd, this effect typically required
mod_rewrite
, and the use of the -f
and
-d
tests for file and directory existence. This now
requires only one line of configuration.
FallbackResource /index.php
Existing files, such as images, css files, and so on, will be served normally.
Use the disabled
argument to disable that feature
if inheritance from a parent directory is not desired.
In a sub-URI, such as http://example.com/blog/ this sub-URI has to be supplied as local-url:
<Directory /web/example.com/htdocs/blog>
FallbackResource /blog/index.php
</Directory>
<Directory /web/example.com/htdocs/blog/images>
FallbackResource disabled
</Directory>