# Module mod_autoindex

The module mod_autoindex generates directory indexes, automatically, similar to the Unix ls command or the Win32 dir shell command.

Automatic index generation must be enabled with by the `Options` directive's `[+]Indexes` option. See the `Options` directive for more details.

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 the `FancyIndexing` option is given with 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. These column header links are suppressed with IndexOptions directive's `SuppressColumnSorting` option.

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
- HeaderName
- IndexIgnore
- IndexOptions
- IndexOrderDefault
- ReadmeName

See also: Options and DirectoryIndex.

## Autoindex Request Query Arguments

Apache 2.0.23 reorganized the Query Arguments for Column Sorting, and introduced an entire group of new query options. To effectively eliminate all client control over the output, the `IndexOptions IgnoreClient` option was introduced.

The column sorting headers themselves are self-referencing hyperlinks that add the sort query options shown below. Any option below may be added to any request for the directory resource.

- `C=N` sorts the directory by file name
- `C=M` sorts the directory by last-modified date, then file name
- `C=S` sorts the directory by size, then file name
- `C=D` sorts the directory by description, then file name
- `O=A` sorts the listing in Ascending Order
- `O=D` sorts the listing in Descending Order
- `F=0` formats the listing as a simple list (not FancyIndexed)
- `F=1` formats the listing as a FancyIndexed list
- `F=2` formats the listing as an HTMLTable FancyIndexed list
- `V=0` disables version sorting
- `V=1` enables version sorting
- `P=pattern` lists only files matching the given pattern

Note that the 'P'attern query argument is tested after the usual IndexIgnore directives are processed, and all file names are still subjected to the same criteria as any other autoindex listing. The Query Arguments parser in mod_autoindex will stop abruptly when an unrecognized option is encountered. The Query Arguments must be well formed, according to the table above.

The simple example below, which can be clipped and saved in a header.html file, illustrates these query options. Note that the unknown "X" argument, for the submit button, is listed last to assure the arguments are all parsed before mod_autoindex encounters the X=Go input.

    <FORM METHOD="GET">
        Show me a <SELECT NAME="F">
          <OPTION VALUE="0"> Plain list
          <OPTION VALUE="1" SELECTED> Fancy list
          <OPTION VALUE="2"> Table list
        </SELECT>
        Sorted by <SELECT NAME="C">
          <OPTION VALUE="N" SELECTED> Name
          <OPTION VALUE="M"> Date Modified
          <OPTION VALUE="S"> Size
          <OPTION VALUE="D"> Description
        </SELECT>
        <SELECT NAME="O">
          <OPTION VALUE="A" SELECTED> Ascending
          <OPTION VALUE="D"> Descending
        </SELECT>
        <SELECT NAME="V">
          <OPTION VALUE="0" SELECTED> in Normal order
          <OPTION VALUE="1"> in Version order
        </SELECT>
        Matching <INPUT TYPE="text" NAME="P" VALUE="*">
        <INPUT TYPE="submit" NAME="X" VALUE="Go">
    </FORM>

## AddAlt directive

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

AddAlt provides 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, has image loading disabled, or fails to retrieve the icon.

## AddAltByEncoding directive

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

AddAltByEncoding provides 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, has image loading disabled, or fails to retrieve the icon.

## AddAltByType directive

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

AddAltByType 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, has image loading disabled, or fails to retrieve the icon.

## 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 typical, default description field is 23 bytes wide. 6 more bytes are added by the `IndexOptions SuppressIcon` option, 7 bytes are added by the `IndexOptions SuppressSize` option, and 19 bytes are added by the `IndexOptions SuppressLastModified` option. Therefore, the widest default the description column is ever assigned is 55 bytes.

See the DescriptionWidth `IndexOptions` keyword for details on overriding the size of this column, or allowing descriptions of unlimited length.

> 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/image.xbm) .gif .jpg .xbm
> AddIcon /icons/dir.xbm ^^DIRECTORY^^
> AddIcon /icons/backup.xbm *~`

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 `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/compress.xbm 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/image.xbm) 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

Deprecated: See IndexOptions `FancyIndexing`

The FancyIndexing directive was replaced by the `FancyIndexing` option to the IndexOptions directive, and is no longer supported in Apache 2.0.

## HeaderName directive

Syntax: HeaderName filename
Context: server config, virtual host, directory, .htaccess
Override: Indexes
Status: Base
Module: mod_autoindex
Compatibility: behavior changed in version 1.3.7; 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.

> Changes with Apache 1.3.7: Both HeaderName and ReadmeName now treat Filename as a URI path relative to the one used to access the directory being indexed. Filename 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 the replacing the list of ignored files. By default, the list contains ``.`'. Example:

> `IndexIgnore README .htaccess *~`

## IndexOptions directive

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; specific options are listed below.

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

DescriptionWidth=[n | *] (Apache 1.3.10 or 2.0.23 and later)
  The `DescriptionWidth` keyword allows you to specify the width of the description column in characters.
  `-DescriptionWidth` (or unset) allows mod_autoindex to calculate the best width.
  `DescriptionWidth=n` fixes the column width to n bytes wide.
  `DescriptionWidth=*` grows the column to the width necessary to accomodate the longest description string.
  See the section on `AddDescription` for dangers inherent in truncating descriptions.
FancyIndexing
  This turns on fancy indexing of directories.
FoldersFirst (Apache 1.3.10 or 2.0.23 and later)
  If this option is enabled, subdirectory listings 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.
HTMLTable (Experimental, Apache 2.0.23 and later)
  This experimental option with FancyIndexing constructs a simple table for the fancy directory listing. Note this will confuse older browsers. It is particularly necessary if file names or description text will alternate between left-to-right and right-to-left reading order, as can happen on WinNT or other utf-8 enabled platforms.
IconsAreLinks
  This makes the icons part of the anchor for the filename, for fancy indexing.
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.
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.
IgnoreClient
  This option causes mod_autoindex to ignore all query variables from the client, including sort order (implies `SuppressColumnSorting`.)
NameWidth=[n | *] (Apache 1.3.2 and later)
  The NameWidth keyword allows you to specify the width of the filename column in bytes.
  `-NameWidth` (or unset) allows mod_autoindex to calculate the best width.
  `NameWidth=n` fixes the column width to n bytes wide.
  `NameWidth=*` grows the column to the necessary width.
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 (Apache 1.3 and later)
  If specified, Apache will not make the column headings in a FancyIndexed directory listing into links for sorting. The default behaviour is for them to be links; selecting the column heading will sort the directory listing by the values in that column. Prior to Apache 2.0.23, this also disabled parsing the Query Arguments for the sort string. That behavior is now controled by IndexOptions IgnoreClient in Apache 2.0.23.
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 behaviour, 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.
SuppressIcon (Apache 2.0.23 and later)
  This will suppress the icon in fancy indexing listings. Combining both SuppressIcon and SuppressRules yields proper HTML 3.2 output, which by the final specification prohibits IMG and HR tags from the PRE block (used to format FancyIndexed listings.)
SuppressLastModified
  This will suppress the display of the last modification date, in fancy indexing listings.
SuppressRules (Apache 2.0.23 and later)
  This will suppress the horizontal rule lines (HR tags) in directory listings. Combining both SuppressIcon and SuppressRules yeilds proper HTML 3.2 output, which by the final specification prohibits IMG and HR tags from the PRE block (used to format FancyIndexed listings.)
SuppressSize
  This will suppress the file size in fancy indexing listings.
TrackModified (Apache 1.3.15 or 2.0.23 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 appropriate stat() results. Some 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. Changes to the size or date stamp of an existing file will not update the Last-Modified header on all Unix platforms. If this is a concern, leave this option disabled.
VersionSort (Apache 2.0a3 and later)
  The VersionSort keyword causes files containing version numbers to sort in a natural way. Strings are sorted as usual, except that substrings of digits in the name and description are compared according to their numeric value. For example:

  >     foo-1.7
  >     foo-1.7.2
  >     foo-1.7.12
  >     foo-1.8.2
  >     foo-1.8.2a
  >     foo-1.12

  If the number starts with a zero, then it is considered to be a fraction:

  >     foo-1.001
  >     foo-1.002
  >     foo-1.030
  >     foo-1.04

### Incremental IndexOptions

  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 any '+' 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 HeaderName

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.

See also HeaderName, where this behavior is described in greater detail.