moddir

mod_dir is a module of the Apache HTTP Server that handles requests for directory URLs. It provides directory index resolution and optional trailing-slash redirection, enabling a predictable way to serve default documents from a directory.

Key directives include DirectoryIndex, which specifies one or more filenames to check inside a directory when a request maps to that directory. The first existing file in the list is served, for example index.html or index.php. DirectorySlash controls whether Apache automatically redirects a directory request that lacks a trailing slash to the same URL with a trailing slash.

Behavior includes serving an index file when one exists in the requested directory. If no index file is found and Options Indexes is enabled, Apache can generate a directory listing via mod_autoindex. If directory listings are disabled, Apache returns a forbidden error. mod_dir does not by itself supply content listings; it coordinates with other modules to determine the final response.

Usage and compatibility: mod_dir is part of Apache since early versions and is typically loaded by default. It can be disabled with the LoadModule directive (for example, LoadModule dir_module modules/mod_dir.so). Directives are allowed in server config, virtual hosts, or directory sections, allowing administrators to tailor index behavior per path.

Example:

DirectoryIndex index.html index.htm

DirectorySlash On