Module mod_mime

This module provides for determining the types of files from the filename and for association of handlers with files.

Status: Base
Source File: mod_mime.c
Module Identifier: mime_module

Summary

The directives AddCharset, AddEncoding, AddHandler, 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, handler, 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. The directives ForceType and SetHandler are used to associated all the files in a given location (e.g., a particular directory) onto a particular MIME type or handler.

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.

Directives

• AddCharset
• AddEncoding
• AddHandler
• AddLanguage
• AddType
• DefaultLanguage
• ForceType
• RemoveEncoding
• RemoveHandler
• RemoveType
• SetHandler
• TypesConfig

See also: MimeMagicFile.

Files with Multiple Extensions

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.

AddCharset directive

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.

See also: mod_negotiation

AddEncoding directive

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

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.

See also: Files with multiple extensions

AddHandler directive

AddHandler maps the filename extensions extension to the handler 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 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.

See also: Files with multiple extensions, SetHandler

AddLanguage directive

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-uk .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.

See also: Files with multiple extensions, DefaultLanguage
See also: mod_negotiation

AddType directive

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

Note that, unlike the NCSA httpd, this directive cannot be used to set the type of particular files.

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

See also: Files with multiple extensions

DefaultLanguage directive

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.

For example:

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.

See also: mod_negotiation
See also: Files with multiple extensions

ForceType directive

When placed into an .htaccess file or a <Directory> or <Location> section, this directive forces all matching files to be served as the content type given by media type. For example, if you had a directory full of GIF files, but did not want to label them all with ".gif", you might want to use:

    ForceType image/gif

Note that this will override any filename extensions that might determine the media type.

You can override any ForceType setting by using the value of none:

    # force all files to be image/gif:
    <Location /images>
      ForceType image/gif
    </Location>

    # but normal mime-type associations here:
    <Location /images/mixed>
      ForceType none
    </Location>

See also: AddType

RemoveEncoding directive

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 mark 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 directive

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.

RemoveType directive

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 default type.

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.

SetHandler directive

When placed into an .htaccess file or a <Directory> or <Location> section, this directive forces all matching files to be parsed through the handler given by handler-name. For example, if you had a directory you wanted to be parsed entirely as imagemap rule files, regardless of extension, you might put the following into an .htaccess file in that directory:

    SetHandler imap-file

Another example: if you wanted to have the server display a status report whenever a URL of http://servername/status was called, you might put the following into access.conf: (See mod_status for more details.)

    <Location /status>
    SetHandler server-status
    </Location>

You can override an earlier defined SetHandler directive by using the value None.

See also: AddHandler

TypesConfig directive

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:

MIME-type extension extension ...