This module is used to associate various bits of "meta
information" with files by their filename extensions. This
information relates the filename of the document to it's
mime-type, language, character set and encoding. This
information is sent to the browser, and participates in content
negotiation, so the user's preferences are respected when
choosing one of several possible files to serve. See
The directives
In addition, mod_mime may define the "handler" for a document, which controls which module or script will serve the document. With the introduction of "filters" in Apache 2.0, mod_mime can also define the filters that the the content should be processed through (e.g. the Includes output filter for server side scripting) and what filters the client request and POST content should be processed through (the input filters.)
The directives
The directive http://www.isi.edu/in-notes/iana/assignments/media-types/media-types
although it may be mirrored elsewhere). This simplifies the
httpd.conf file by providing the majority of media-type
definitions, and they may be overridden by
The core directives
Note that changing the type or encoding of a file does not
change the value of the Last-Modified header.
Thus, previously cached copies may still be used by a client or
proxy, with the previous headers. If you change the
meta-information (language, content type, character set or
encoding) you may need to 'touch' affected files (updating
their last modified date) to ensure that all visitors are
receive the corrected content headers.
Files can have more than one extension, and the order of the
extensions is normally irrelevant. For example, if the
file welcome.html.fr maps onto content type
text/html and language French then the file welcome.fr.html
will map onto exactly the same information. If more than one
extension is given which maps onto the same
type of meta-information, then the one to the right will be
used. For example, if ".gif" maps to the MIME-type image/gif
and ".html" maps to the MIME-type text/html, then the file
welcome.gif.html will be associated with the
MIME-type "text/html".
Care should be taken when a file with multiple extensions
gets associated with both a MIME-type and a handler. This will
usually result in the request being by the module associated
with the handler. For example, if the .imap
extension is mapped to the handler "imap-file" (from mod_imap)
and the .html extension is mapped to the MIME-type
"text/html", then the file world.imap.html will be
associated with both the "imap-file" handler and "text/html"
MIME-type. When it is processed, the "imap-file" handler will
be used, and so it will be treated as a mod_imap imagemap
file.
A file of a particular MIME type can additionally be encoded a
particular way to simplify transmission over the Internet.
While this usually will refer to compression, such as
gzip, it can also refer to encryption, such a
pgp or to an encoding such as UUencoding, which is
designed for transmitting a binary file in an ASCII (text)
format.
The MIME RFC puts it this way:
By using more than one file extension (see section above about multiple file extensions), you can indicate that a file is of a particular type, and also has a particular encoding.
For example, you may have a file which is a Microsoft Word
document, which is pkzipped to reduce its size. If the
.doc extension is associated with the Microsoft
Word file type, and the .zip extension is
associated with the pkzip file encoding, then the file
Resume.doc.zipwould be known to be a pkzip'ed Word
document.
Apache send a Content-encoding header with the
resource, in order to tell the client browser about the
encoding method.
In addition to file type and the file encoding, another important piece of information is what language a particular document is in, and in what character set the file should be displayed. For example, the document might be written in the Vietnamese alphabet, or in Cyrillic, and should be displayed as such. This information, also, is transmitted in HTTP headers.
The character set, language encoding and mime type are all
used in the process of content negotiation (See
To convey this further information, Apache optionally sends
a Content-Language header, to specify the language
that the document is in, and can append additional information
onto the Content-Type header to indicate the
particular character set that should be used to correctly
render the information.
The language specification is the two-letter abbreviation
for the language. The charset is the name of the
particular character set which should be used.
The AddCharset directive maps the given filename extensions to the specified content charset. charset is the MIME charset parameter of filenames containing extension. This mapping is added to any already in force, overriding any mappings that already exist for the same extension.
Example:
Then the document xxxx.ja.jis will be treated
as being a Japanese document whose charset is ISO-2022-JP (as
will the document xxxx.jis.ja). The AddCharset
directive is useful for both to inform the client about the
character encoding of the document so that the document can be
interpreted and displayed appropriately, and for content negotiation,
where the server returns one from several documents based on
the client's charset preference.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The AddEncoding directive maps the given filename extensions to the specified encoding type. MIME-enc is the MIME encoding to use for documents containing the extension. This mapping is added to any already in force, overriding any mappings that already exist for the same extension. Example:
This will cause filenames containing the .gz extension to be marked as encoded using the x-gzip encoding, and filenames containing the .Z extension to be marked as encoded with x-compress.
Old clients expect x-gzip and
x-compress, however the standard dictates that
they're equivalent to gzip and
compress respectively. Apache does content
encoding comparisons by ignoring any leading x-.
When responding with an encoding Apache will use whatever form
(i.e., x-foo or foo) the
client requested. If the client didn't specifically request a
particular form Apache will use the form given by the
AddEncoding directive. To make this long story
short, you should always use x-gzip and
x-compress for these two specific encodings. More
recent encodings, such as deflate should be
specified without the x-.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
This mapping is added to any already in
force, overriding any mappings that already exist for the same
extension. For example, to activate CGI scripts with
the file extension ".cgi", you might use:
Once that has been put into your srm.conf or httpd.conf
file, any file containing the ".cgi" extension
will be treated as a CGI program.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
AddInputFilter maps the filename extensions extension to the filter or filters which will process client requests and POST input when they are received by the server. This is in addition to any filters defined elsewhere, including the SetInputFilter directive. This mapping is merged over any already in force, overriding any mappings that already exist for the same extension.
If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content. Both the filter and extension arguments are case-insensitive, and the extension may be specified with or without a leading dot.
The AddLanguage directive maps the given filename extension to the specified content language. MIME-lang is the MIME language of filenames containing extension. This mapping is added to any already in force, overriding any mappings that already exist for the same extension.
Example:
Then the document xxxx.en.Z will be treated as
being a compressed English document (as will the document
xxxx.Z.en). Although the content language is
reported to the client, the browser is unlikely to use this
information. The AddLanguage directive is more useful for content negotiation,
where the server returns one from several documents based on
the client's language preference.
If multiple language assignments are made for the same extension, the last one encountered is the one that is used. That is, for the case of:
documents with the extension ".en" would be
treated as being "en-us".
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The
For example, the following configuration will process all .shtml files for server-side includes.
If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content. Both the filter and extension arguments are case-insensitive, and the extension may be specified with or without a leading dot.
The AddType directive maps the given filename extensions
onto the specified content type. MIME-type is the MIME
type to use for filenames containing extension. This
mapping is added to any already in force, overriding any
mappings that already exist for the same extension.
This directive can be used to add mappings not listed in the
MIME types file (see the
Example:
The extension argument is case-insensitive, and can be specified with or without a leading dot.
MultiviewsMatch permits three different behaviors for mod_negotiation's Multiviews feature. Multiviews allows a request for a file, e.g. index.html, to match any negotiated extensions following the base request, e.g. index.html.en, index.html,fr, or index.html.gz.
The NegotiatedOnly option provides that every extension following the base name must correlate to a recognized mod_mime extension for content negotation, e.g. Charset, Content-Type, Language, or Encoding. This is the strictest implementation with the fewest unexpected side effects, and is the default behavior.
To include extensions associated with Handlers and/or Filters, set the MultiviewsMatch directive to either Handlers, Filters, or both option keywords. If all other factors are equal, the smallest file will be served, e.g. in deciding between index.html.cgi of 500 characters and index.html.pl of 1000 bytes, the .cgi file would win in this example. Users of .asis files might prefer to use the Handler option, if .asis files are associated with the asis-handler.
You may finally allow Any extensions to match, even if mod_mime doesn't recognize the extension. This was the behavior in Apache 1.3, and can cause unpredicatable results, such as serving .old or .bak files the webmaster never expected to be served.
The DefaultLanguage directive tells Apache that all files in
the directive's scope (e.g., all files covered by the
current <Directory> container) that don't
have an explicit language extension (such as .fr
or .de as configured by AddLanguage)
should be considered to be in the specified MIME-lang
language. This allows entire directories to be marked as
containing Dutch content, for instance, without having to
rename each file. Note that unlike using extensions to specify
languages, DefaultLanguage can only specify a
single language.
If no DefaultLanguage directive is in force,
and a file does not have any language extensions as configured
by AddLanguage, then that file will be considered
to have no language attribute.
The RemoveCharset directive removes any
character set associations for files with the given extensions.
This allows .htaccess files in subdirectories to
undo any associations inherited from parent directories or the
server config files.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The RemoveEncoding directive removes any
encoding associations for files with the given extensions. This
allows .htaccess files in subdirectories to undo
any associations inherited from parent directories or the
server config files. An example of its use might be:
/foo/.htaccess:AddEncoding x-gzip .gzAddType text/plain .asc<Files *.gz.asc> RemoveEncoding
.gz</Files>This will cause foo.gz to be marked as being
encoded with the gzip method, but foo.gz.asc as an
unencoded plaintext file.
Note:RemoveEncoding directives are processed after any AddEncoding directives, so it is possible they may undo the effects of the latter if both occur within the same directory configuration.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The RemoveHandler directive removes any handler
associations for files with the given extensions. This allows
.htaccess files in subdirectories to undo any
associations inherited from parent directories or the server
config files. An example of its use might be:
/foo/.htaccess:AddHandler server-parsed .html/foo/bar/.htaccess:RemoveHandler .htmlThis has the effect of returning .html files in
the /foo/bar directory to being treated as normal
files, rather than as candidates for parsing (see the mod_include
module).
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The RemoveInputFilter directive removes any
input filter associations for files with the given extensions.
This allows .htaccess files in subdirectories to
undo any associations inherited from parent directories or the
server config files.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The RemoveLanguage directive removes any
language associations for files with the given extensions. This
allows .htaccess files in subdirectories to undo
any associations inherited from parent directories or the
server config files.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The RemoveOutputFilter directive removes any
output filter associations for files with the given extensions.
This allows .htaccess files in subdirectories to
undo any associations inherited from parent directories or the
server config files.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The .htaccess files in subdirectories to undo any
associations inherited from parent directories or the server
config files. An example of its use might be:
/foo/.htaccess:RemoveType .cgiThis will remove any special handling of .cgi
files in the /foo/ directory and any beneath it,
causing the files to be treated as being of the default type.
The extension argument is case-insensitive, and can be specified with or without a leading dot.
The TypesConfig directive sets the location of the MIME types configuration file. Filename is relative to the ServerRoot. This file sets the default list of mappings from filename extensions to content types; changing this file is not recommended. Use the AddType directive instead. The file contains lines in the format of the arguments to an AddType command:
The extensions are lower-cased. Blank lines, and lines beginning with a hash character (`#') are ignored.