mod_mime Associates the requested filename's extensions with the file's behavior (handlers and filters) and content (mime-type, language, character set and encoding) Base mod_mime.c mime_module

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 mod_negotiation for more information about content negotiation.

The directives AddCharset, AddEncoding, AddLanguage and AddType are all used to map file extensions onto the meta-information for that file. Respectively they set the character set, content-encoding, content-language, and MIME-type (content-type) of documents. The directive TypesConfig is used to specify a file which also maps extensions onto MIME types.

In addition, mod_mime may define the handler and filters that originate and process content. The directives AddHandler, AddOutputFilter, and AddInputFilter control the modules or scripts that serve the document. The MultiviewsMatch directive allows mod_negotiation to consider these file extensions to be included when testing Multiviews matches.

While mod_mime associates meta-information with filename extensions, the core server provides directives that are used to associate all the files in a given container (e.g., Location, Directory, or Files) with particular meta-information. These directives include ForceType, SetHandler, SetInputFilter, and SetOutputFilter. The core directives override any filename extension mappings defined in mod_mime.

Note that changing the meta-information for 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.

 MimeMagicFile AddDefaultCharset ForceType DefaultType SetHandler SetInputFilter SetOutputFilter
Files with Multiple Extensions

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, except for languages and content encodings. 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.

Languages and content encodings are treated accumulative, because one can assign more than one language or encoding to a particular ressource. For example, the file welcome.html.en.de will be delivered with Content-Language: en, de and Content-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.

Content encoding

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 HTTP/1.1 RFC, section 14.11 puts it this way:

The Content-Encoding entity-header field is used as a modifier to the media-type. When present, its value indicates what additional content codings have been applied to the entity-body, and thus what decoding mechanisms must be applied in order to obtain the media-type referenced by the Content-Type header field. Content-Encoding is primarily used to allow a document to be compressed without losing the identity of its underlying media type.

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.zip would be known to be a pkzip'ed Word document.

Apache sends a Content-encoding header with the resource, in order to tell the client browser about the encoding method.

Content-encoding: pkzip
Character sets and languages

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 mod_negotiation) to determine which document to give to the client, when there are alternative documents in more than one character set, language, encoding or mime type. All filename extensions associations created with AddCharset, AddEncoding, AddLanguage and AddType directives (and extensions listed in the MimeMagicFile) participate in this select process. Filename extensions that are only associated using the AddHandler, AddInputFilter or AddOutputFilter directives may be included or excluded from matching by using the MultiviewsMatch directive.

Charset

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.

Content-Language: en, fr
Content-Type: text/plain; charset=ISO-8859-1

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.

AddCharset Maps the given filename extensions to the specified content charset AddCharset charset extension [extension] ... server configvirtual host directory.htaccess FileInfo

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 AddLanguage ja .ja
AddCharset EUC-JP .euc
AddCharset ISO-2022-JP .jis
AddCharset SHIFT_JIS .sjis

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.

 mod_negotiation AddDefaultCharset AddEncoding Maps the given filename extensions to the specified encoding type AddEncoding MIME-enc extension [extension] ... server configvirtual host directory.htaccess FileInfo

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 AddEncoding x-gzip .gz
AddEncoding x-compress .Z

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.

 AddHandler Maps the filename extensions to the specified handler AddHandler handler-name extension [extension] ... server configvirtual host directory.htaccess FileInfo

Files having the name extension will be served by the specified handler-name. 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:

AddHandler cgi-script .cgi

Once that has been put into your 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.

 SetHandler AddInputFilter Maps filename extensions to the filters that will process client requests AddInputFilter filter[;filter...] extension [extension] ... server configvirtual host directory.htaccess FileInfo AddInputFilter is only available in Apache 2.0.26 and later.

AddInputFilter maps the filename extension extension to the 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.

 RemoveInputFilter SetInputFilter AddLanguage Maps the given filename extension to the specified content language AddLanguage MIME-lang extension [extension] ... server configvirtual host directory.htaccess FileInfo

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 AddEncoding x-compress .Z
AddLanguage en .en
AddLanguage fr .fr

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:

AddLanguage en .en
AddLanguage en-gb .en
AddLanguage en-us .en

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.

 mod_negotiation AddOutputFilter Maps filename extensions to the filters that will process responses from the server AddOutputFilter filter[;filter...] extension [extension] ... server configvirtual host directory.htaccess FileInfo AddOutputFilter is only available in Apache 2.0.26 and later.

The AddOutputFilter directive maps the filename extension extension to the filters which will process responses from the server before they are sent to the client. This is in addition to any filters defined elsewhere, including SetOutputFilter and AddOutputFilterByType directive. This mapping is merged over any already in force, overriding any mappings that already exist for the same extension.

For example, the following configuration will process all .shtml files for server-side includes and will then compress the output using mod_deflate.

AddOutputFilter INCLUDES;DEFLATE shtml

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.

 RemoveOutputFilter SetOutputFilter AddType Maps the given filename extensions onto the specified content type AddType MIME-type extension [extension] ... server configvirtual host directory.htaccess FileInfo

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 TypesConfig directive).

Example AddType image/gif .gif It is recommended that new MIME types be added using the AddType directive rather than changing the TypesConfig file.

The extension argument is case-insensitive, and can be specified with or without a leading dot.

 DefaultType ForceType MultiviewsMatch The types of files that will be included when searching for a matching file with MultiViews MultiviewsMatch Any|NegotiatedOnly|Filters|Handlers [Handlers|Filters] MultiviewsMatch NegotiatedOnly server configvirtual host directory.htaccess FileInfo Available in Apache 2.0.26 and later.

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 bytes 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.

For example, the following configuration will allow handlers and filters to participate in Multviews, but will exclude unknown files:

MultiviewsMatch Handlers Filters Options mod_negotiation DefaultLanguage Sets all files in the given scope to the specified language DefaultLanguage MIME-lang server configvirtual host directory.htaccess FileInfo

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.

Example DefaultLanguage en mod_negotiation ModMimeUsePathInfo Tells mod_mime to treat path_info components as part of the filename ModMimeUsePathInfo On|Off ModMimeUsePathInfo Off directory Available in Apache 2.0.41 and later

The ModMimeUsePathInfo directive is used to combine the filename with the path_info URL component to apply mod_mime's directives to the request. The default value is Off - therefore, the path_info component is ignored.

This directive is recommended when you have a virtual filesystem.

Example ModMimeUsePathInfo On

If you have a request for /bar/foo.shtml where /bar is a Location and ModMimeUsePathInfo is On, mod_mime will treat the incoming request as /bar/foo.shtml and directives like AddOutputFilter INCLUDES .shtml will add the INCLUDES filter to the request. If ModMimeUsePathInfo is not set, the INCLUDES filter will not be added.

 AcceptPathInfo RemoveCharset Removes any character set associations for a set of file extensions RemoveCharset extension [extension] ... virtual hostdirectory .htaccess FileInfo RemoveCharset is only available in Apache 2.0.24 and later.

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.

Example RemoveCharset .html .shtml RemoveEncoding Removes any content encoding associations for a set of file extensions RemoveEncoding extension [extension] ... virtual hostdirectory .htaccess FileInfo

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 .gz
AddType 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.

 RemoveHandler Removes any handler associations for a set of file extensions RemoveHandler extension [extension] ... virtual hostdirectory .htaccess FileInfo

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 .html

This 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.

 RemoveInputFilter Removes any input filter associations for a set of file extensions RemoveInputFilter extension [extension] ... virtual hostdirectory .htaccess FileInfo RemoveInputFilter is only available in Apache 2.0.26 and later.

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.

 AddInputFilter SetInputFilter RemoveLanguage Removes any language associations for a set of file extensions RemoveLanguage extension [extension] ... virtual hostdirectory .htaccess FileInfo RemoveLanguage is only available in Apache 2.0.24 and later.

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.

 RemoveOutputFilter Removes any output filter associations for a set of file extensions RemoveOutputFilter extension [extension] ... virtual hostdirectory .htaccess FileInfo RemoveOutputFilter is only available in Apache 2.0.26 and later.

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.

Example RemoveOutputFilter shtml AddOutputFilter RemoveType Removes any content type associations for a set of file extensions RemoveType extension [extension] ... virtual hostdirectory .htaccess FileInfo

The RemoveType directive removes any MIME type 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: RemoveType .cgi

This 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 DefaultType.

Note

RemoveType directives are processed after any AddType 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.

 TypesConfig The location of the mime.types file TypesConfig file-path TypesConfig conf/mime.types server config

The TypesConfig directive sets the location of the MIME types configuration file. File-path is relative to the ServerRoot. This file sets the default list of mappings from filename extensions to content types. Most administrators use the provided mime.types file, which associates common filename extensions with IANA registered content types. The current list is maintained at http://www.isi.edu/in-notes/iana/assignments/media-types/media-types. This simplifies the httpd.conf file by providing the majority of media-type definitions, and may be overridden by AddType directives as needed. You should not edit the mime.types file, because it may be replaced when you upgrade your server.

The file contains lines in the format of the arguments to an AddType directive:

MIME-type [extension] ...

The case of the extension does not matter. Blank lines, and lines beginning with a hash character (#) are ignored.

Please do not send requests to the Apache HTTP Server Project to add any new entries in the distributed mime.types file unless (1) they are already registered with IANA, and (2) they use widely accepted, non-conflicting filename extensions across platforms. category/x-subtype requests will be automatically rejected, as will any new two-letter extensions as they will likely conflict later with the already crowded language and character set namespace. mod_mime_magic