Apache module mod_autoindex

### Apache HTTP Server Version 1.3

# Module mod_autoindex

This module provides for automatic directory indexing.

Status: Base
Source File: mod_autoindex.c
Module Identifier: autoindex_module

## Summary

The index of a directory can come from one of two sources:

- A file written by the user, typically called `index.html`. The DirectoryIndex directive sets the name of this file. This is controlled by `mod_dir`.
- Otherwise, a listing generated by the server. The other directives control the format of this listing. The AddIcon, AddIconByEncoding and AddIconByType are used to set a list of icons to display for various file types; for each file listed, the first icon listed that matches the file is displayed. These are controlled by `mod_autoindex`.

The two functions are separated so that you can completely remove (or replace) automatic index generation should you want to.

Automatic index generation is enabled with using `Options +Indexes`. See the `Options` directive for more details.

If `FancyIndexing` is enabled, or the `FancyIndexing` keyword is present on the `IndexOptions` directive, the column headers are links that control the order of the display. If you select a header link, the listing will be regenerated, sorted by the values in that column. Selecting the same header repeatedly toggles between ascending and descending order.

Note that when the display is sorted by "Size", it's the actual size of the files that's used, not the displayed value - so a 1010-byte file will always be displayed before a 1011-byte file (if in ascending order) even though they both are shown as "1K".

## Directives

- AddAlt
- AddAltByEncoding
- AddAltByType
- AddDescription
- AddIcon
- AddIconByEncoding
- AddIconByType
- DefaultIcon
- FancyIndexing
- HeaderName
- IndexIgnore
- IndexOptions
- IndexOrderDefault
- ReadmeName

See also: Options and DirectoryIndex.

## Autoindex Request Query Arguments

The column sorting headers themselves are self-referencing hyperlinks that add the sort query options to reorder the directory listing. The query options are of the form `X=Y`, where `X` is one of `N` (file Name), `M` (file last Modified date), `S` (file Size, or `D` (file Description), and `Y` is one of `A` (Ascending) or `D` (Descending).

When options other than the file name are used as the sorting key, the secondary key is always the file name. (When the file name is used to sort by, there is no need of a secondary sort key, since file names are guaranteed to be unique, and so the sort order is unambiguous.)

Example:

If the URL `http://your.server.name/foo/` produces a directory index, then the following URLs will produce different sort orders:

- `http://your.server.name/foo/?M=D` sorts the directory by last modified date, descending.
- `http://your.server.name/foo/?D=A` sorts the directory by file description, ascending.
- `http://your.server.name/foo/?S=A` sorts the directory by file size, ascending.

See `IndexOrderDefault` to set the default directory ordering.

Note also that when the directory listing is ordered in one direction (ascending or descending) by a particular column, the link at the top of that column then reverses, to allow sorting in the opposite direction by that same column.

## AddAlt directive

Syntax: AddAlt string file [file] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the alternate text to display for a file, instead of an icon, for FancyIndexing. File is a file extension, partial filename, wild-card expression or full filename for files to describe. String is enclosed in double quotes (`"`). This alternate text is displayed if the client is image-incapable or has image loading disabled.

Examples:

        AddAlt "PDF" *.pdf
        AddAlt "Compressed" *.gz *.zip *.Z

## AddAltByEncoding directive

Syntax: AddAltByEncoding string MIME-encoding [MIME-encoding] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the alternate text to display for a file, instead of an icon, for FancyIndexing. MIME-encoding is a valid content-encoding, such as `x-compress`. String is enclosed in double quotes (`"`). This alternate text is displayed if the client is image-incapable or has image loading disabled.

Example:

        AddAltByEncoding "gzip" x-gzip

## AddAltByType directive

Syntax: AddAltByType string MIME-type [MIME-type] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the alternate text to display for a file, instead of an icon, for FancyIndexing. MIME-type is a valid content-type, such as `text/html`. String is enclosed in double quotes (`"`). This alternate text is displayed if the client is image-incapable or has image loading disabled.

Example:

        AddAltByType "TXT" text/plain

## AddDescription directive

Syntax: AddDescription string file [file] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the description to display for a file, for FancyIndexing. File is a file extension, partial filename, wild-card expression or full filename for files to describe. String is enclosed in double quotes (`"`). Example:

> `AddDescription "The planet Mars" /web/pics/mars.gif`

The description field is 23 bytes wide. 7 more bytes may be added if the directory is covered by an `IndexOptions SuppressSize`, and 19 bytes may be added if `IndexOptions SuppressLastModified` is in effect. The widest this column can be is therefore 49 bytes.

> As of Apache 1.3.10, the DescriptionWidth `IndexOptions` keyword allows you to adjust this width to any arbitrary size.

Caution: Descriptive text defined with `AddDescription` may contain HTML markup, such as tags and character entities. If the width of the description column should happen to truncate a tagged element (such as cutting off the end of a bolded phrase), the results may affect the rest of the directory listing.

## AddIcon directive

Syntax: AddIcon icon name [name] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the icon to display next to a file ending in name for FancyIndexing. Icon is either a (%-escaped) relative URL to the icon, or of the format (alttext,url) where alttext is the text tag given for an icon for non-graphical browsers.

Name is either ^^DIRECTORY^^ for directories, ^^BLANKICON^^ for blank lines (to format the list correctly), a file extension, a wildcard expression, a partial filename or a complete filename. Examples:

> `AddIcon (IMG,/icons/image2.gif) .gif .jpg .png
> AddIcon /icons/dir.gif ^^DIRECTORY^^
> AddIcon /icons/backup.gif *~`

AddIconByType should be used in preference to AddIcon, when possible.

## AddIconByEncoding directive

Syntax: AddIconByEncoding icon MIME-encoding [MIME-encoding] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the icon to display next to files with MIME-encoding for FancyIndexing. Icon is either a (%-escaped) relative URL to the icon, or of the format (alttext,url) where alttext is the text tag given for an icon for non-graphical browsers.

Mime-encoding is a wildcard expression matching required the content-encoding. Examples:

> `AddIconByEncoding /icons/compressed.gif x-compress`

## AddIconByType directive

Syntax: AddIconByType icon MIME-type [MIME-type] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

This sets the icon to display next to files of type MIME-type for FancyIndexing. Icon is either a (%-escaped) relative URL to the icon, or of the format (alttext,url) where alttext is the text tag given for an icon for non-graphical browsers.

Mime-type is a wildcard expression matching required the mime types. Examples:

> `AddIconByType (IMG,/icons/image3.gif) image/*`

## DefaultIcon directive

Syntax: DefaultIcon url
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

The DefaultIcon directive sets the icon to display for files when no specific icon is known, for FancyIndexing. Url is a (%-escaped) relative URL to the icon. Examples:

> `DefaultIcon /icon/unknown.xbm`

## FancyIndexing directive

Syntax: FancyIndexing on|off
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

The FancyIndexing directive sets the FancyIndexing option for a directory. The IndexOptions directive should be used in preference.

> Note that in versions of Apache prior to 1.3.2, the `FancyIndexing` and `IndexOptions` directives will override each other. You should use `IndexOptions FancyIndexing` in preference to the standalone `FancyIndexing` directive. As of Apache 1.3.2, a standalone `FancyIndexing` directive is combined with any `IndexOptions` directive already specified for the current scope.

## HeaderName directive

Syntax: HeaderName filename
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex
Compatibility: some features only available after 1.3.6; see text

The HeaderName directive sets the name of the file that will be inserted at the top of the index listing. Filename is the name of the file to include.

> Apache 1.3.6 and earlier: The module first attempts to include filename`.html` as an HTML document, otherwise it will try to include filename as plain text. Filename is treated as a filesystem path relative to the directory being indexed. In no case is SSI processing done. Example:

> > `HeaderName HEADER`

> when indexing the directory `/web`, the server will first look for the HTML file `/web/HEADER.html` and include it if found, otherwise it will include the plain text file `/web/HEADER`, if it exists.

> Apache versions after 1.3.6: Filename is treated as a URI path relative to the one used to access the directory being indexed, and must resolve to a document with a major content type of "`text`" (e.g., `text/html`, `text/plain`, etc.). This means that filename may refer to a CGI script if the script's actual file type (as opposed to its output) is marked as `text/html` such as with a directive like:

>         AddType text/html .cgi

> Content negotiation will be performed if the `MultiViews` option is enabled. If filename resolves to a static `text/html` document (not a CGI script) and the `Includes` option is enabled, the file will be processed for server-side includes (see the `mod_include` documentation).

If the file specified by `HeaderName` contains the beginnings of an HTML document (<HTML>, <HEAD>, etc) then you will probably want to set `IndexOptions +SuppressHTMLPreamble`, so that these tags are not repeated.

See also ReadmeName.

## IndexIgnore directive

Syntax: IndexIgnore file [file] ...
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex

The IndexIgnore directive adds to the list of files to hide when listing a directory. File is a file extension, partial filename, wildcard expression or full filename for files to ignore. Multiple IndexIgnore directives add to the list, rather than replacing the list of ignored files. By default, the list contains ``.`'. Example:

> `IndexIgnore README .htaccess *~`

## IndexOptions directive

Syntax: IndexOptions option [option] ... (Apache 1.3.2 and earlier)
Syntax: IndexOptions [+|-]option [[+|-]option] ... (Apache 1.3.3 and later)
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex
Compatibility: '+/-' syntax and merging of multiple `IndexOptions` directives is only available with Apache 1.3.3 and later; the `FoldersFirst` and `DescriptionWidth` options are only available with Apache 1.3.10 and later; the `TrackModified` option is only available with Apache 1.3.15 and later

The IndexOptions directive specifies the behavior of the directory indexing. Option can be one of

DescriptionWidth=[n | *] (Apache 1.3.10 and later)
  The `DescriptionWidth` keyword allows you to specify the width of the description column in characters. If the keyword value is '`*`', then the column is automatically sized to the length of the longest filename in the display. See the section on `AddDescription` for dangers inherent in truncating descriptions.
FancyIndexing
  This turns on fancy indexing of directories.

  > Note that in versions of Apache prior to 1.3.2, the `FancyIndexing` and `IndexOptions` directives will override each other. You should use `IndexOptions FancyIndexing` in preference to the standalone `FancyIndexing` directive. As of Apache 1.3.2, a standalone `FancyIndexing` directive is combined with any `IndexOptions` directive already specified for the current scope.

FoldersFirst (Apache 1.3.10 and later)
  If this option is enabled, subdirectories in a FancyIndexed listing will always appear first, followed by normal files in the directory. The listing is basically broken into two components, the files and the subdirectories, and each is sorted separately and then displayed subdirectories-first. For instance, if the sort order is descending by name, and `FoldersFirst` is enabled, subdirectory `Zed` will be listed before subdirectory `Beta`, which will be listed before normal files `Gamma` and `Alpha`. This option only has an effect if `FancyIndexing` is also enabled.
IconHeight[=pixels] (Apache 1.3 and later)
  Presence of this option, when used with IconWidth, will cause the server to include `HEIGHT` and `WIDTH` attributes in the `IMG` tag for the file icon. This allows browser to precalculate the page layout without having to wait until all the images have been loaded. If no value is given for the option, it defaults to the standard height of the icons supplied with the Apache software.
IconsAreLinks
  This makes the icons part of the anchor for the filename, for fancy indexing.
IconWidth[=pixels] (Apache 1.3 and later)
  Presence of this option, when used with IconHeight, will cause the server to include `HEIGHT` and `WIDTH` attributes in the `IMG` tag for the file icon. This allows browser to precalculate the page layout without having to wait until all the images have been loaded. If no value is given for the option, it defaults to the standard width of the icons supplied with the Apache software.
NameWidth=[n | *] (Apache 1.3.2 and later)
  The NameWidth keyword allows you to specify the width of the filename column in bytes. If the keyword value is '`*`', then the column is automatically sized to the length of the longest filename in the display.
ScanHTMLTitles
  This enables the extraction of the title from HTML documents for fancy indexing. If the file does not have a description given by AddDescription then httpd will read the document for the value of the TITLE tag. This is CPU and disk intensive.
SuppressColumnSorting
  If specified, Apache will not make the column headings in a FancyIndexed directory listing into links for sorting. The default behavior is for them to be links; selecting the column heading will sort the directory listing by the values in that column. Only available in Apache 1.3 and later.
SuppressDescription
  This will suppress the file description in fancy indexing listings. By default, no file descriptions are defined, and so the use of this option will regain 23 characters of screen space to use for something else. See `AddDescription` for information about setting the file description. See also the `DescriptionWidth` index option to limit the size of the description column.
SuppressHTMLPreamble (Apache 1.3 and later)
  If the directory actually contains a file specified by the HeaderName directive, the module usually includes the contents of the file after a standard HTML preamble (<HTML>, <HEAD>, et cetera). The SuppressHTMLPreamble option disables this behavior, causing the module to start the display with the header file contents. The header file must contain appropriate HTML instructions in this case. If there is no header file, the preamble is generated as usual.
SuppressLastModified
  This will suppress the display of the last modification date, in fancy indexing listings.
SuppressSize
  This will suppress the file size in fancy indexing listings.
TrackModified (Apache 1.3.15 and later)
  This returns the Last-Modified and ETag values for the listed directory in the HTTP header. It is only valid if the operating system and file system return legitimate stat() results. Most Unix systems do so, as do OS2's JFS and Win32's NTFS volumes. OS2 and Win32 FAT volumes, for example, do not. Once this feature is enabled, the client or proxy can track changes to the list of files when they perform a HEAD request. Note some operating systems correctly track new and removed files, but do not track changes for sizes or dates of the files within the directory.

There are some noticeable differences in the behavior of this directive in recent (post-1.3.0) versions of Apache.

Apache 1.3.2 and earlier:

  The default is that no options are enabled. If multiple IndexOptions could apply to a directory, then the most specific one is taken complete; the options are not merged. For example:

  >     <Directory /web/docs>
  >         IndexOptions FancyIndexing
  >     </Directory>
  >     <Directory /web/docs/spec>
  >         IndexOptions ScanHTMLTitles
  >     </Directory>

  then only `ScanHTMLTitles` will be set for the /web/docs/spec directory.
Apache 1.3.3 and later:

  Apache 1.3.3 introduced some significant changes in the handling of `IndexOptions` directives. In particular,

  - Multiple `IndexOptions` directives for a single directory are now merged together. The result of the example above will now be the equivalent of `IndexOptions FancyIndexing ScanHTMLTitles`.
  - The addition of the incremental syntax (i.e., prefixing keywords with '+' or '-').

  Whenever a '+' or '-' prefixed keyword is encountered, it is applied to the current `IndexOptions` settings (which may have been inherited from an upper-level directory). However, whenever an unprefixed keyword is processed, it clears all inherited options and any incremental settings encountered so far. Consider the following example:

  > `IndexOptions +ScanHTMLTitles -IconsAreLinks FancyIndexing
  > IndexOptions +SuppressSize
  > `

  The net effect is equivalent to `IndexOptions FancyIndexing +SuppressSize`, because the unprefixed `FancyIndexing` discarded the incremental keywords before it, but allowed them to start accumulating again afterward.

  To unconditionally set the `IndexOptions` for a particular directory, clearing the inherited settings, specify keywords without either '+' or '-' prefixes.

## IndexOrderDefault directive

Syntax: IndexOrderDefault Ascending|Descending Name|Date|Size|Description
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex
Compatibility: IndexOrderDefault is only available in Apache 1.3.4 and later.

The `IndexOrderDefault` directive is used in combination with the `FancyIndexing` index option. By default, fancyindexed directory listings are displayed in ascending order by filename; the `IndexOrderDefault` allows you to change this initial display order.

`IndexOrderDefault` takes two arguments. The first must be either `Ascending` or `Descending`, indicating the direction of the sort. The second argument must be one of the keywords `Name`, `Date`, `Size`, or `Description`, and identifies the primary key. The secondary key is always the ascending filename.

You can force a directory listing to only be displayed in a particular order by combining this directive with the `SuppressColumnSorting` index option; this will prevent the client from requesting the directory listing in a different order.

## ReadmeName directive

Syntax: ReadmeName filename
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex
Compatibility: some features only available after 1.3.6; see text

The ReadmeName directive sets the name of the file that will be appended to the end of the index listing. Filename is the name of the file to include, and is taken to be relative to the location being indexed.

> The filename argument is treated as a stub filename in Apache 1.3.6 and earlier, and as a relative URI in later versions. Details of how it is handled may be found under the description of the HeaderName directive, which uses the same mechanism and changed at the same time as ReadmeName.

See also HeaderName.

### Apache HTTP Server Version 1.3