elisp: Startup Summary
38.1.1 Summary: Sequence of Actions at Startup
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When Emacs is started up, it performs the following operations (see
‘normal-top-level’ in ‘startup.el’):
1. It adds subdirectories to ‘load-path’, by running the file named
‘subdirs.el’ in each directory in the list. Normally, this file
adds the directory’s subdirectories to the list, and those are
scanned in their turn. The files ‘subdirs.el’ are normally
generated automatically when Emacs is installed.
2. It loads any ‘leim-list.el’ that it finds in the ‘load-path’
directories. This file is intended for registering input methods.
The search is only for any personal ‘leim-list.el’ files that you
may have created; it skips the directories containing the standard
Emacs libraries (these should contain only a single ‘leim-list.el’
file, which is compiled into the Emacs executable).
3. It sets the variable ‘before-init-time’ to the value of
‘current-time’ (
Time of Day). It also sets
‘after-init-time’ to ‘nil’, which signals to Lisp programs that
Emacs is being initialized.
4. It sets the language environment and the terminal coding system, if
requested by environment variables such as ‘LANG’.
5. It does some basic parsing of the command-line arguments.
6. If not running in batch mode, it initializes the window system that
the variable ‘initial-window-system’ specifies (
initial-window-system Window Systems.). The initialization
function for each supported window system is specified by
‘window-system-initialization-alist’. If the value of
‘initial-window-system’ is WINDOWSYSTEM, then the appropriate
initialization function is defined in the file
‘term/WINDOWSYSTEM-win.el’. This file should have been compiled
into the Emacs executable when it was built.
7. It runs the normal hook ‘before-init-hook’.
8. If appropriate, it creates a graphical frame. This is not done if
the options ‘--batch’ or ‘--daemon’ were specified.
9. It initializes the initial frame’s faces, and sets up the menu bar
and tool bar if needed. If graphical frames are supported, it sets
up the tool bar even if the current frame is not a graphical one,
since a graphical frame may be created later on.
10. It use ‘custom-reevaluate-setting’ to re-initialize the members of
the list ‘custom-delayed-init-variables’. These are any pre-loaded
user options whose default value depends on the run-time, rather
than build-time, context. custom-initialize-delay Building
Emacs.
11. It loads the library ‘site-start’, if it exists. This is not done
if the options ‘-Q’ or ‘--no-site-file’ were specified.
12. It loads your init file (Init File). This is not done if
the options ‘-q’, ‘-Q’, or ‘--batch’ were specified. If the ‘-u’
option was specified, Emacs looks for the init file in that user’s
home directory instead.
13. It loads the library ‘default’, if it exists. This is not done if
‘inhibit-default-init’ is non-‘nil’, nor if the options ‘-q’, ‘-Q’,
or ‘--batch’ were specified.
14. It loads your abbrevs from the file specified by
‘abbrev-file-name’, if that file exists and can be read (
abbrev-file-name Abbrev Files.). This is not done if the option
‘--batch’ was specified.
15. It calls the function ‘package-initialize’ to activate any
optional Emacs Lisp package that has been installed.
Packaging Basics. However, Emacs doesn’t initialize packages
when ‘package-enable-at-startup’ is ‘nil’ or when it’s started with
one of the options ‘-q’, ‘-Q’, or ‘--batch’. To initialize
packages in the latter case, ‘package-initialize’ should be called
explicitly (e.g., via the ‘--funcall’ option).
16. It sets the variable ‘after-init-time’ to the value of
‘current-time’. This variable was set to ‘nil’ earlier; setting it
to the current time signals that the initialization phase is over,
and, together with ‘before-init-time’, provides the measurement of
how long it took.
17. It runs the normal hook ‘after-init-hook’.
18. If the buffer ‘*scratch*’ exists and is still in Fundamental mode
(as it should be by default), it sets its major mode according to
‘initial-major-mode’.
19. If started on a text terminal, it loads the terminal-specific Lisp
library (Terminal-Specific), and runs the hook
‘tty-setup-hook’. This is not done in ‘--batch’ mode, nor if
‘term-file-prefix’ is ‘nil’.
20. It displays the initial echo area message, unless you have
suppressed that with ‘inhibit-startup-echo-area-message’.
21. It processes any command-line options that were not handled
earlier.
22. It now exits if the option ‘--batch’ was specified.
23. If the ‘*scratch*’ buffer exists and is empty, it inserts
‘(substitute-command-keys initial-scratch-message)’ into that
buffer.
24. If ‘initial-buffer-choice’ is a string, it visits the file (or
directory) with that name. If it is a function, it calls the
function with no arguments and selects the buffer that it returns.
If one file is given as a command line argument, that file is
visited and its buffer displayed alongside ‘initial-buffer-choice’.
If more than one file is given, all of the files are visited and
the ‘*Buffer List*’ buffer is displayed alongside
‘initial-buffer-choice’.
25. It runs ‘emacs-startup-hook’.
26. It calls ‘frame-notice-user-settings’, which modifies the
parameters of the selected frame according to whatever the init
files specify.
27. It runs ‘window-setup-hook’. The only difference between this
hook and ‘emacs-startup-hook’ is that this one runs after the
previously mentioned modifications to the frame parameters.
28. It displays the “startup screen”, which is a special buffer that
contains information about copyleft and basic Emacs usage. This is
not done if ‘inhibit-startup-screen’ or ‘initial-buffer-choice’ are
non-‘nil’, or if the ‘--no-splash’ or ‘-Q’ command-line options
were specified.
29. If the option ‘--daemon’ was specified, it calls ‘server-start’,
and on Posix systems also detaches from the controlling terminal.
(emacs)Emacs Server.
30. If started by the X session manager, it calls
‘emacs-session-restore’ passing it as argument the ID of the
previous session. Session Management.
The following options affect some aspects of the startup sequence.
-- User Option: inhibit-startup-screen
This variable, if non-‘nil’, inhibits the startup screen. In that
case, Emacs typically displays the ‘*scratch*’ buffer; but see
‘initial-buffer-choice’, below.
Do not set this variable in the init file of a new user, or in a
way that affects more than one user, as that would prevent new
users from receiving information about copyleft and basic Emacs
usage.
‘inhibit-startup-message’ and ‘inhibit-splash-screen’ are aliases
for this variable.
-- User Option: initial-buffer-choice
If non-‘nil’, this variable is a string that specifies a file or
directory for Emacs to display after starting up, instead of the
startup screen. If its value is a function, Emacs calls that
function which must return a buffer which is then displayed. If
its value is ‘t’, Emacs displays the ‘*scratch*’ buffer.
-- User Option: inhibit-startup-echo-area-message
This variable controls the display of the startup echo area
message. You can suppress the startup echo area message by adding
text with this form to your init file:
(setq inhibit-startup-echo-area-message
"YOUR-LOGIN-NAME")
Emacs explicitly checks for an expression as shown above in your
init file; your login name must appear in the expression as a Lisp
string constant. You can also use the Customize interface. Other
methods of setting ‘inhibit-startup-echo-area-message’ to the same
value do not inhibit the startup message. This way, you can easily
inhibit the message for yourself if you wish, but thoughtless
copying of your init file will not inhibit the message for someone
else.
-- User Option: initial-scratch-message
This variable, if non-‘nil’, should be a string, which is treated
as documentation to be inserted into the ‘*scratch*’ buffer when
Emacs starts up. If it is ‘nil’, the ‘*scratch*’ buffer is empty.
The following command-line options affect some aspects of the startup
sequence. (emacs)Initial Options.
‘--no-splash’
Do not display a splash screen.
‘--batch’
Run without an interactive terminal. Batch Mode.
‘--daemon’
Do not initialize any display; just start a server in the
background.
‘--no-init-file’
‘-q’
Do not load either the init file, or the ‘default’ library.
‘--no-site-file’
Do not load the ‘site-start’ library.
‘--quick’
‘-Q’
Equivalent to ‘-q --no-site-file --no-splash’.
Info Catalog
elisp: Starting Up
elisp: Init File