5 Entering Emacs
The usual way to invoke Emacs is with the shell command
emacs. From a terminal window running a Unix shell on a GUI
terminal, you can run Emacs in the background with emacs &; this
way, Emacs won’t tie up the terminal window, so you can use it to run
other shell commands. (For comparable methods of starting Emacs on
MS-Windows, see How to Start Emacs on MS-Windows.)
When Emacs starts up, the initial frame displays a special buffer
named ‘ *GNU Emacs*’. This startup screen contains
information about Emacs and links to common tasks that are
useful for beginning users. For instance, activating the ‘ Emacs Tutorial’ link opens the Emacs tutorial; this does the same thing as
the command C-h t ( help-with-tutorial). To activate a
link, either move point onto it and type RET, or click on
it with mouse-1 (the left mouse button).
Using a command line argument, you can tell Emacs to visit one or
more files as soon as it starts up. For example, emacs foo.txt starts Emacs with a buffer displaying the contents of the
file ‘ foo.txt’. This feature exists mainly for compatibility
with other editors, which are designed to be launched from the shell
for short editing sessions. If you call Emacs this way, the initial
frame is split into two windows—one showing the specified file, and
the other showing the startup screen. See Multiple Windows.
Generally, it is unnecessary and wasteful to start Emacs afresh each time you want to edit a file. The recommended way to use Emacs is to start it just once, just after you log in, and do all your editing in the same Emacs session. See File Handling, for information on visiting more than one file. If you use Emacs this way, the Emacs session accumulates valuable context, such as the kill ring, registers, undo history, and mark ring data, which together make editing more convenient. These features are described later in the manual.
To edit a file from another program while Emacs is running, you can
use the emacsclient helper program to open a file in the
existing Emacs session. See Using Emacs as a Server.
Emacs accepts other command line arguments that tell it to load certain Lisp files, where to put the initial frame, and so forth. See Command Line Arguments for Emacs Invocation.
If the variable inhibit-startup-screen is non- nil,
Emacs does not display the startup screen. In that case, if one or
more files were specified on the command line, Emacs simply displays
those files; otherwise, it displays a buffer named *scratch*,
which can be used to evaluate Emacs Lisp expressions interactively.
See Lisp Interaction Buffers. You can set the variable
inhibit-startup-screen using the Customize facility
(see Easy Customization Interface), or by editing your initialization file
(see The Emacs Initialization File). 4
You can also force Emacs to display a file or directory at startup
by setting the variable initial-buffer-choice to a string
naming that file or directory. The value of
initial-buffer-choice may also be a function (of no arguments)
that should return a buffer which is then displayed.
If initial-buffer-choice is non- nil, then if you specify
any files on the command line, Emacs still visits them, but does not
display them initially.
Footnotes
(4)
Setting inhibit-startup-screen in
site-start.el doesn’t work, because the startup screen is set
up before reading site-start.el. See The Emacs Initialization File, for
information about site-start.el.