doc/emacs/entering.texi

   1 @c This is part of the Emacs manual.
   2 @c Copyright (C) 1985-1987, 1993-1995, 2001-2012
   3 @c   Free Software Foundation, Inc.
   4 @c See file emacs.texi for copying conditions.
   5 @iftex
   6 @chapter Entering and Exiting Emacs
   7
   8   This chapter explains how to enter Emacs, and how to exit it.
   9 @end iftex
  10
  11 @ifnottex
  12 @raisesections
  13 @end ifnottex
  14
  15 @node Entering Emacs, Exiting, Commands, Top
  16 @section Entering Emacs
  17 @cindex entering Emacs
  18 @cindex starting Emacs
  19
  20   The usual way to invoke Emacs is with the shell command
  21 @command{emacs}.  From a terminal window running in the X Window
  22 System, you can run Emacs in the background with @command{emacs &};
  23 this way, Emacs won't tie up the terminal window, so you can use it to
  24 run other shell commands.
  25
  26 @cindex startup screen
  27   When Emacs starts up, the initial frame displays a special buffer
  28 named @samp{*GNU Emacs*}.  This @dfn{startup screen} contains
  29 information about Emacs and @dfn{links} to common tasks that are
  30 useful for beginning users.  For instance, activating the @samp{Emacs
  31 Tutorial} link opens the Emacs tutorial; this does the same thing as
  32 the command @kbd{C-h t} (@code{help-with-tutorial}).  To activate a
  33 link, either move point onto it and type @kbd{@key{RET}}, or click on
  34 it with @kbd{mouse-1} (the left mouse button).
  35
  36   Using a command line argument, you can tell Emacs to visit one or
  37 more files as soon as it starts up.  For example, @command{emacs
  38 foo.txt} starts Emacs with a buffer displaying the contents of the
  39 file @samp{foo.txt}.  This feature exists mainly for compatibility
  40 with other editors, which are designed to be launched from the shell
  41 for short editing sessions.  If you call Emacs this way, the initial
  42 frame is split into two windows---one showing the specified file, and
  43 the other showing the startup screen.  @xref{Windows}.
  44
  45   Generally, it is unnecessary and wasteful to start Emacs afresh each
  46 time you want to edit a file.  The recommended way to use Emacs is to
  47 start it just once, just after you log in, and do all your editing in
  48 the same Emacs session.  @xref{Files}, for information on visiting
  49 more than one file.  If you use Emacs this way, the Emacs session
  50 accumulates valuable context, such as the kill ring, registers, undo
  51 history, and mark ring data, which together make editing more
  52 convenient.  These features are described later in the manual.
  53
  54   To edit a file from another program while Emacs is running, you can
  55 use the @command{emacsclient} helper program to open a file in the
  56 existing Emacs session.  @xref{Emacs Server}.
  57
  58   Emacs accepts other command line arguments that tell it to load
  59 certain Lisp files, where to put the initial frame, and so forth.
  60 @xref{Emacs Invocation}.
  61
  62 @vindex inhibit-startup-screen
  63   If the variable @code{inhibit-startup-screen} is non-@code{nil},
  64 Emacs does not display the startup screen.  In that case, if one or
  65 more files were specified on the command line, Emacs simply displays
  66 those files; otherwise, it displays a buffer named @samp{*scratch*},
  67 which can be used to evaluate Emacs Lisp expressions interactively.
  68 @xref{Lisp Interaction}.  You can set the variable
  69 @code{inhibit-startup-screen} using the Customize facility
  70 (@pxref{Easy Customization}), or by editing your initialization file
  71 (@pxref{Init File}).@footnote{Setting @code{inhibit-startup-screen} in
  72 @file{site-start.el} doesn't work, because the startup screen is set
  73 up before reading @file{site-start.el}.  @xref{Init File}, for
  74 information about @file{site-start.el}.}
  75
  76   You can also force Emacs to display a file or directory at startup
  77 by setting the variable @code{initial-buffer-choice} to a
  78 non-@code{nil} value.  (In that case, even if you specify one or more
  79 files on the command line, Emacs opens but does not display them.)
  80 The value of @code{initial-buffer-choice} can be either the name of
  81 the desired file or directory, or @code{t}, which means to display the
  82 @samp{*scratch*} buffer.
  83
  84 @node Exiting, Basic, Entering Emacs, Top
  85 @section Exiting Emacs
  86 @cindex exiting
  87 @cindex killing Emacs
  88 @cindex leaving Emacs
  89 @cindex quitting Emacs
  90
  91 @table @kbd
  92 @item C-x C-c
  93 Kill Emacs (@code{save-buffers-kill-terminal}).
  94 @item C-z
  95 On a text terminal, suspend Emacs; on a graphical display,
  96 ``minimize'' the selected frame (@code{suspend-emacs}).
  97 @end table
  98
  99 @kindex C-x C-c
 100 @findex save-buffers-kill-terminal
 101   @dfn{Killing} Emacs means terminating the Emacs program.  To do
 102 this, type @kbd{C-x C-c} (@code{save-buffers-kill-terminal}).  A
 103 two-character key sequence is used to make it harder to type by
 104 accident.  If there are any modified file-visiting buffers when you
 105 type @kbd{C-x C-c}, Emacs first offers to save these buffers.  If you
 106 do not save them all, it asks for confirmation again, since the
 107 unsaved changes will be lost.  Emacs also asks for confirmation if any
 108 subprocesses are still running, since killing Emacs will also kill the
 109 subprocesses (@pxref{Shell}).
 110
 111   @kbd{C-x C-c} behaves specially if you are using Emacs as a server.
 112 If you type it from a ``client frame'', it closes the client
 113 connection.  @xref{Emacs Server}.
 114
 115   Emacs can, optionally, record certain session information when you
 116 kill it, such as the files you were visiting at the time.  This
 117 information is then available the next time you start Emacs.
 118 @xref{Saving Emacs Sessions}.
 119
 120 @vindex confirm-kill-emacs
 121   If the value of the variable @code{confirm-kill-emacs} is
 122 non-@code{nil}, @kbd{C-x C-c} assumes that its value is a predicate
 123 function, and calls that function.  If the result of the function call
 124 is non-@code{nil}, the session is killed, otherwise Emacs continues to
 125 run.  One convenient function to use as the value of
 126 @code{confirm-kill-emacs} is the function @code{yes-or-no-p}.  The
 127 default value of @code{confirm-kill-emacs} is @code{nil}.
 128
 129 @findex kill-emacs
 130   To kill Emacs without being prompted about saving, type @kbd{M-x
 131 kill-emacs}.
 132
 133 @kindex C-z
 134 @findex suspend-frame
 135 @cindex minimizing
 136 @cindex iconifying
 137 @cindex suspending
 138   @kbd{C-z} runs the command @code{suspend-frame}.  On a graphical
 139 display, this command @dfn{minimizes} (or @dfn{iconifies}) the
 140 selected Emacs frame, hiding it in a way that lets you bring it back
 141 later (exactly how this hiding occurs depends on the window system).
 142 On a text terminal, the @kbd{C-z} command @dfn{suspends} Emacs,
 143 stopping the program temporarily and returning control to the parent
 144 process (usually a shell); in most shells, you can resume Emacs after
 145 suspending it with the shell command @command{%emacs}.
 146
 147   Text-only terminals usually listen for certain special characters
 148 whose meaning is to kill or suspend the program you are running.
 149 @b{This terminal feature is turned off while you are in Emacs.}  The
 150 meanings of @kbd{C-z} and @kbd{C-x C-c} as keys in Emacs were inspired
 151 by the use of @kbd{C-z} and @kbd{C-c} on several operating systems as
 152 the characters for stopping or killing a program, but that is their
 153 only relationship with the operating system.  You can customize these
 154 keys to run any commands of your choice (@pxref{Keymaps}).
 155
 156 @ifnottex
 157 @lowersections
 158 @end ifnottex