Apache HTTP Server Version 2.0
.htaccess
files provide a way to make configuration
changes on a per-directory basis.
Related Modules | Related Directives |
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.htaccess
files (or "distributed configuration files")
provide a way to make configuration changes on a per-directory basis. A
file, containing one or more configuration directives, is placed in a
particular document directory, and the directives apply to that
directory, and all subdirectories thereof.
Note: If you want to call your .htaccess
file something
else, you can change the name of the file using the AccessFileName
directive. For example, if you would rather call the file
.config
then you can put the following in your server
configuration file:
AccessFileName .config
What you can put in these files is determined by the AllowOverride
directive. This directive specifies, in categories, what directives
will be honored if they are found in a .htaccess
file. If
a directive is permitted in a .htaccess
file, the
documentation for that directive will contain an Override section,
specifying what value must be in AllowOverride
in order
for that directive to be permitted.
For example, if you look at the documentation for the AddDefaultCharset
directive, you will find that it is permitted in .htaccess
files. (See the Context line in the directive summary.) The Override line reads
"FileInfo
". Thus, you must have at least
"AllowOverride FileInfo
" in order for this directive to be
honored in .htaccess
files.
If you are unsure whether a particular directive is permitted in a
.htaccess
file, look at the documentation for that
directive, and check the Context line for ".htaccess."
In general, you should never use .htaccess
files unless
you don't have access to the main server configuration file. There is,
for example, a prevailing misconception that user authentication should
always be done in .htaccess
files. This is simply not the
case. You can put user authentication configurations in the main server
configuration, and this is, in fact, the preferred way to do
things.
.htaccess
files should be used in a case where the
content providers need to make configuration changes to the server on a
per-directory basis, but do not have root access on the server system.
In the event that the server administrator is not willing to make
frequent configuration changes, it might be desirable to permit
individual users to make these changes in .htaccess
files
for themselves. This is particularly true, for example, in cases where
ISPs are hosting multiple user sites on a single machine, and want
their users to be able to alter their configuration.
However, in general, use of .htaccess
files should be
avoided when possible. Any configuration that you would consider
putting in a .htaccess
file, can just as effectively be
made in a <Directory>
section in your main server
configuration file.
There are two main reasons to avoid the use of
.htaccess
files.
The first of these is performance. When AllowOverride
is set to allow the use of .htaccess
files, Apache will
look in every directory for .htaccess
files. Thus,
permitting .htaccess
files causes a performance hit,
whether or not you actually even use them! Also, the
.htaccess
file is loaded every time a document is
requested.
Further note that Apache must look for .htaccess
files
in all higher-level directories, in order to have a full complement of
directives that it must apply. (See section on how
directives are applied.) Thus, if a file is requested out of a
directory /www/htdocs/example
, Apache must look for the
following files:
/.htaccess
/www/.htaccess
/www/htdocs/.htaccess
/www/htdocs/example/.htaccess
And so, for each file access out of that directory, there are 4 additional file-system accesses, even if none of those files are present. (Note that this would only be the case if .htaccess files were enabled for /, which is not usually the case.)
The second consideration is one of security. You are permitting
users to modify server configuration, which may result in changes over
which you have no control. Carefully consider whether you want to give
your users this privilege. Note also that giving users less
privileges than they need will lead to additional technical support
requests. Make sure you clearly tell your users what level of
privileges you have given them. Specifying exactly what you have set
AllowOverride
to, and pointing them to the relevant
documentation, will save yourself a lot of confusion later.
Note that it is completely equivalent to put a .htaccess file in a
directory /www/htdocs/example
containing a directive, and
to put that same directive in a Directory section <Directory
/www/htdocs/example>
in your main server configuration:
.htaccess
file in /www/htdocs/example
:
/www/htdocs/example
AddType text/example .exm
httpd.conf
file
<Directory /www/htdocs/example>
AddType text/example .exm
</Directory>
However, putting this configuration in your server configuration file will result in less of a performance hit, as the configuration is loaded once when Apache starts, rather than every time a file is requested.
The use of .htaccess
files can be disabled completely
by setting the AllowOverride
directive to "none"
AllowOverride None
The configuration directives found in a .htaccess
file
are applied to the directory in which the .htaccess
file
is found, and to all subdirectories thereof. However, it is important
to also remember that there may have been .htaccess
files
in directories higher up. Directives are applied in the order that they
are found. Therefore, a .htaccess
file in a particular
directory may override directives found in .htaccess
files
found higher up in the directory tree. And those, in turn, may have
overridden directives found yet higher up, or in the main server
configuration file itself.
Example:
In the directory /www/htdocs/example1
we have a
.htaccess
file containing the following:
Options +ExecCGI
(Note: you must have "AllowOverride Options
" in effect
to permit the use of the "Options
" directive in
.htaccess
files.)
In the directory /www/htdocs/example1/example2
we have
a .htaccess
file containing:
Options Includes
Because of this second .htaccess
file, in the directory
/www/htdocs/example1/example2
, CGI execution is not
permitted, as only Options Includes
is in effect, which
completely overrides any earlier setting that may have been in
place.
If you jumped directly to this part of the document to find out how
to do authentication, it is important to note one thing. There is a
common misconception that you are required to use
.htaccess
files in order to implement password
authentication. This is not the case. Putting authentication directives
in a <Directory>
section, in your main server
configuration file, is the preferred way to implement this, and
.htaccess
files should be used only if you don't have
access to the main server configuration file. See above for a discussion of when you should and should
not use .htaccess
files.
Having said that, if you still think you need to use a
.htaccess
file, you may find that a configuration such as
what follows may work for you.
You must have "AllowOverride AuthConfig
" in effect for
these directives to be honored.
.htaccess
file contents:
AuthType Basic
AuthName "Password Required"
AuthUserFile /www/passwords/password.file
AuthGroupFile /www/passwords/group.file
Require Group admins
Note that AllowOverride AuthConfig
must be in effect
for these directives to have any effect.
Please sHTTP/1.1 200 OK Date: Mon, 07 Jul 2025 04:57:01 GMT Server: Apache/2.0.42 (Win32) PHP/5.2.10 Content-Location: htaccess.html.en Vary: negotiate TCN: choice Accept-Ranges: bytes Content-Length: 19499 Keep-Alive: timeout=15, max=100 Connection: Keep-Alive Content-Type: text/html; charset=ISO-8859-1 Content-Language: en
Apache HTTP Server Version 2.0
.htaccess
files provide a way to make configuration
changes on a per-directory basis.
Related Modules | Related Directives |
---|---|