@node Entering Emacs, Exiting, Pull-down Menus, Top
@chapter Entering and Exiting Emacs
@cindex entering Emacs
@cindex entering XEmacs

  The usual way to invoke Emacs is to type @kbd{emacs @key{RET}} at the
shell (for XEmacs, type @kbd{xemacs @key{RET}}).  Emacs clears the
screen and then displays an initial advisory message and copyright
notice.  You can begin typing Emacs commands immediately afterward.

  Some operating systems insist on discarding all type-ahead when Emacs
starts up; they give Emacs no way to prevent this.  Therefore, it is
wise to wait until Emacs clears the screen before typing the first
editing command.

@vindex initial-major-mode
  Before Emacs reads the first command, you have not had a chance to
give a command to specify a file to edit.  Since Emacs must always have a
current buffer for editing, it presents a buffer, by default, a buffer named
@samp{*scratch*}.  The buffer is in Lisp Interaction
mode; you can use it to type Lisp expressions and evaluate them, or you
can ignore that capability and simply doodle.  You can specify a
different major mode for this buffer by setting the variable
@code{initial-major-mode} in your init file.  @xref{Init File}.

  It is possible to give Emacs arguments in the shell command line to
specify files to visit, Lisp files to load, and functions to call.

@node Exiting, Command Switches, Entering Emacs, Top
@section Exiting Emacs
@cindex exiting
@cindex killing Emacs
@cindex suspending
@cindex shrinking XEmacs frame

  There are two commands for exiting Emacs because there are two kinds
of exiting: @dfn{suspending} Emacs and @dfn{killing} Emacs.
@dfn{Suspending} means stopping Emacs temporarily and returning control
to its superior (usually the shell), allowing you to resume editing
later in the same Emacs job, with the same files, same kill ring, same
undo history, and so on.  This is the usual way to exit.  @dfn{Killing}
Emacs means destroying the Emacs job.  You can run Emacs again later,
but you will get a fresh Emacs; there is no way to resume the same
editing session after it has been killed.

@table @kbd
@item C-z
Suspend Emacs (@code{suspend-emacs}).  If used under the X window system,
shrink the X window containing the Emacs frame to an icon (see below).
@item C-x C-c
Kill Emacs (@code{save-buffers-kill-emacs}).
@end table

If you use XEmacs under the X window system, @kbd{C-z} shrinks
the X window containing the Emacs frame to an icon.  The Emacs process
is stopped temporarily, and control is returned to the window manager.
If more than one frame is associated with the Emacs process, only the
frame from which you used @kbd{C-z} is retained.  The X windows
containing the other Emacs frames are closed. 

To activate the "suspended" Emacs, use the appropriate window manager
mouse gestures.  Usually left-clicking on the icon reactivates and
reopens the X window containing the Emacs frame, but the window manager
you use determines what exactly happens.  To actually kill the Emacs
process, use @kbd{C-x C-c} or the @b{Exit Emacs} item on the @b{File}
menu.

@kindex C-z
@findex suspend-emacs
  On systems that do not permit programs to be suspended, @kbd{C-z} runs
an inferior shell that communicates directly with the terminal, and
Emacs waits until you exit the subshell.  On these systems, the only way
to return to the shell from which Emacs was started (to log out, for
example) is to kill Emacs.  @kbd{C-d} or @code{exit} are typical
commands to exit a subshell.

@kindex C-x C-c
@findex save-buffers-kill-emacs
  To kill Emacs, type @kbd{C-x C-c} (@code{save-buffers-kill-emacs}).  A
two-character key is used for this to make it harder to type.  In
XEmacs, selecting the @b{Exit Emacs} option of the @b{File} menu is an
alternate way of issuing the command.

Unless a numeric argument is used, this command first offers to save any
modified buffers.  If you do not save all buffers, you are asked for
reconfirmation with @kbd{yes} before killing Emacs, since any changes
not saved will be lost.  If any subprocesses are still running, @kbd{C-x
C-c} asks you to confirm killing them, since killing Emacs kills the
subprocesses simultaneously.

  In most programs running on Unix, certain characters may instantly
suspend or kill the program.  (In Berkeley Unix these characters are
normally @kbd{C-z} and @kbd{C-c}.)  @i{This Unix feature is turned off
while you are in Emacs.} The meanings of @kbd{C-z} and @kbd{C-x C-c} as
keys in Emacs were inspired by the standard Berkeley Unix meanings of
@kbd{C-z} and @kbd{C-c}, but that is their only relationship with Unix.
You could customize these keys to do anything (@pxref{Keymaps}).

@c ??? What about system V here?