38.1.2 The Init File

When you start Emacs, it normally attempts to load your init file. This is either a file named .emacs or .emacs.el in your home directory, or a file named init.el in a subdirectory named .emacs.d in your home directory.

The command-line switches ‘-q’, ‘-Q’, and ‘-u’ control whether and where to find the init file; ‘-q’ (and the stronger ‘-Q’) says not to load an init file, while ‘-u user’ says to load user’s init file instead of yours. See Entering Emacs in The GNU Emacs Manual. If neither option is specified, Emacs uses the LOGNAME environment variable, or the USER (most systems) or USERNAME (MS systems) variable, to find your home directory and thus your init file; this way, even if you have su’d, Emacs still loads your own init file. If those environment variables are absent, though, Emacs uses your user-id to find your home directory.

An Emacs installation may have a default init file, which is a Lisp library named default.el. Emacs finds this file through the standard search path for libraries (see How Programs Do Loading). The Emacs distribution does not come with this file; it is intended for local customizations. If the default init file exists, it is loaded whenever you start Emacs. But your own personal init file, if any, is loaded first; if it sets inhibit-default-init to a non-nil value, then Emacs does not subsequently load the default.el file. In batch mode, or if you specify ‘-q’ (or ‘-Q’), Emacs loads neither your personal init file nor the default init file.

Another file for site-customization is site-start.el. Emacs loads this before the user’s init file. You can inhibit the loading of this file with the option ‘--no-site-file’.

User Option: site-run-file

This variable specifies the site-customization file to load before the user’s init file. Its normal value is "site-start". The only way you can change it with real effect is to do so before dumping Emacs.

See Init File Examples in The GNU Emacs Manual, for examples of how to make various commonly desired customizations in your .emacs file.

User Option: inhibit-default-init

If this variable is non-nil, it prevents Emacs from loading the default initialization library file. The default value is nil.

Variable: before-init-hook

This normal hook is run, once, just before loading all the init files (site-start.el, your init file, and default.el). (The only way to change it with real effect is before dumping Emacs.)

Variable: after-init-hook

This normal hook is run, once, just after loading all the init files (site-start.el, your init file, and default.el), before loading the terminal-specific library (if started on a text terminal) and processing the command-line action arguments.

Variable: emacs-startup-hook

This normal hook is run, once, just after handling the command line arguments. In batch mode, Emacs does not run this hook.

Variable: window-setup-hook

This normal hook is very similar to emacs-startup-hook. The only difference is that it runs slightly later, after setting of the frame parameters. See window-setup-hook.

Variable: user-init-file

This variable holds the absolute file name of the user’s init file. If the actual init file loaded is a compiled file, such as .emacs.elc, the value refers to the corresponding source file.

Variable: user-emacs-directory

This variable holds the name of the .emacs.d directory. It is ~/.emacs.d on all platforms but MS-DOS.