1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985-1987, 1993-1995, 1997, 2001-2016 Free Software
4 @c See file emacs.texi for copying conditions.
6 @appendix Command Line Arguments for Emacs Invocation
7 @cindex command line arguments
8 @cindex arguments (command line)
9 @cindex options (command line)
10 @cindex switches (command line)
11 @cindex startup (command line arguments)
12 @cindex invocation (command line arguments)
13 @c FIXME: Document '--smid'? --xfq
15 Emacs supports command line arguments to request various actions
16 when invoking Emacs. These are for compatibility with other editors
17 and for sophisticated activities. We don't recommend using them for
18 ordinary editing (@xref{Emacs Server}, for a way to access an existing
19 Emacs job from the command line).
21 Arguments starting with @samp{-} are @dfn{options}, and so is
22 @samp{+@var{linenum}}. All other arguments specify files to visit.
23 Emacs visits the specified files while it starts up. The last file
24 specified on the command line becomes the current buffer; the other
25 files are also visited in other buffers. As with most programs, the
26 special argument @samp{--} says that all subsequent arguments are file
27 names, not options, even if they start with @samp{-}.
29 Emacs command options can specify many things, such as the size and
30 position of the X window Emacs uses, its colors, and so on. A few
31 options support advanced usage, such as running Lisp functions on files
32 in batch mode. The sections of this chapter describe the available
33 options, arranged according to their purpose.
35 There are two ways of writing options: the short forms that start with
36 a single @samp{-}, and the long forms that start with @samp{--}. For
37 example, @samp{-d} is a short form and @samp{--display} is the
38 corresponding long form.
40 The long forms with @samp{--} are easier to remember, but longer to
41 type. However, you don't have to spell out the whole option name; any
42 unambiguous abbreviation is enough. When a long option takes an
43 argument, you can use either a space or an equal sign to separate the
44 option name and the argument. Thus, you can write either
45 @samp{--display sugar-bombs:0.0} or @samp{--display=sugar-bombs:0.0}.
46 We recommend an equal sign because it makes the relationship clearer,
47 and the tables below always show an equal sign.
49 @cindex initial options (command line)
50 @cindex action options (command line)
51 @vindex command-line-args
52 Most options specify how to initialize Emacs, or set parameters for
53 the Emacs session. We call them @dfn{initial options}. A few options
54 specify things to do, such as loading libraries or calling Lisp
55 functions. These are called @dfn{action options}. These and file
56 names together are called @dfn{action arguments}. The action
57 arguments are stored as a list of strings in the variable
58 @code{command-line-args}. (Actually, when Emacs starts up,
59 @code{command-line-args} contains all the arguments passed from the
60 command line; during initialization, the initial arguments are removed
61 from this list when they are processed, leaving only the action
65 * Action Arguments:: Arguments to visit files, load libraries,
67 * Initial Options:: Arguments that take effect while starting Emacs.
68 * Command Example:: Examples of using command line arguments.
69 * Environment:: Environment variables that Emacs uses.
70 * Display X:: Changing the default display and using remote login.
71 * Font X:: Choosing a font for text, under X.
72 * Colors X:: Choosing display colors.
73 * Window Size X:: Start-up window size, under X.
74 * Borders X:: Internal and external borders, under X.
75 * Title X:: Specifying the initial frame's title.
76 * Icons X:: Choosing what sort of icon to use, under X.
77 * Misc X:: Other display options.
80 @node Action Arguments
81 @appendixsec Action Arguments
83 Here is a table of action arguments:
88 @itemx --file=@var{file}
90 @itemx --find-file=@var{file}
92 @itemx --visit=@var{file}
93 @cindex visiting files, command-line argument
94 @vindex inhibit-startup-buffer-menu
95 Visit @var{file} using @code{find-file}. @xref{Visiting}.
97 When Emacs starts up, it displays the startup buffer in one window,
98 and the buffer visiting @var{file} in another window
99 (@pxref{Windows}). If you supply more than one file argument, the
100 displayed file is the last one specified on the command line; the
101 other files are visited but their buffers are not shown.
103 If the startup buffer is disabled (@pxref{Entering Emacs}), then
104 @var{file} is visited in a single window if one file argument was
105 supplied; with two file arguments, Emacs displays the files in two
106 different windows; with more than two file argument, Emacs displays
107 the last file specified in one window, plus a Buffer Menu in a
108 different window (@pxref{Several Buffers}). To inhibit using the
109 Buffer Menu for this, change the variable
110 @code{inhibit-startup-buffer-menu} to @code{t}.
112 @item +@var{linenum} @var{file}
113 @opindex +@var{linenum}
114 Visit @var{file} using @code{find-file}, then go to line number
117 @item +@var{linenum}:@var{columnnum} @var{file}
118 Visit @var{file} using @code{find-file}, then go to line number
119 @var{linenum} and put point at column number @var{columnnum}.
123 @itemx --load=@var{file}
125 @cindex loading Lisp libraries, command-line argument
126 Load a Lisp library named @var{file} with the function @code{load}.
127 If @var{file} is not an absolute file name, Emacs first looks for it
128 in the current directory, then in the directories listed in
129 @code{load-path} (@pxref{Lisp Libraries}).
131 @strong{Warning:} If previous command-line arguments have visited
132 files, the current directory is the directory of the last file
137 @itemx --directory=@var{dir}
139 Prepend directory @var{dir} to the variable @code{load-path}.
140 If you specify multiple @samp{-L} options, Emacs preserves the
141 relative order; i.e., using @samp{-L /foo -L /bar} results in
142 a @code{load-path} of the form @code{("/foo" "/bar" @dots{})}.
143 If @var{dir} begins with @samp{:}, Emacs removes the @samp{:} and
144 appends (rather than prepends) the remainder to @code{load-path}.
145 (On MS Windows, use @samp{;} instead of @samp{:}; i.e., use
146 the value of @code{path-separator}.)
148 @item -f @var{function}
150 @itemx --funcall=@var{function}
152 @cindex call Lisp functions, command-line argument
153 Call Lisp function @var{function}. If it is an interactive function
154 (a command), it reads the arguments interactively just as if you had
155 called the same function with a key sequence. Otherwise, it calls the
156 function with no arguments.
158 @item --eval=@var{expression}
160 @itemx --execute=@var{expression}
162 @cindex evaluate expression, command-line argument
163 Evaluate Lisp expression @var{expression}.
165 @item --insert=@var{file}
167 @cindex insert file contents, command-line argument
168 Insert the contents of @var{file} into the buffer that is current when
169 this command-line argument is processed. Usually, this is the
170 @file{*scratch*} buffer (@pxref{Lisp Interaction}), but if arguments
171 earlier on the command line visit files or switch buffers, that might
172 be a different buffer. The effect of this command-line argument is
173 like what @kbd{M-x insert-file} does (@pxref{Misc File Ops}).
177 Exit from Emacs without asking for confirmation.
181 Print a usage message listing all available options, then exit
186 Print Emacs version, then exit successfully.
189 @node Initial Options
190 @appendixsec Initial Options
192 The initial options specify parameters for the Emacs session. This
193 section describes the more general initial options; some other options
194 specifically related to the X Window System appear in the following
197 Some initial options affect the loading of the initialization file.
198 Normally, Emacs first loads @file{site-start.el} if it exists, then
199 your own initialization file if it exists, and finally the default
200 initialization file @file{default.el} if it exists (@pxref{Init
201 File}). Certain options prevent loading of some of these files or
202 substitute other files for them.
205 @item -chdir @var{directory}
207 @itemx --chdir=@var{directory}
209 @cindex change Emacs directory
210 Change to @var{directory} before doing anything else. This is mainly used
211 by session management in X so that Emacs starts in the same directory as it
212 stopped. This makes desktop saving and restoring easier.
214 @item -t @var{device}
216 @itemx --terminal=@var{device}
218 @cindex device for Emacs terminal I/O
219 Use @var{device} as the device for terminal input and output. This
220 option implies @samp{--no-window-system}.
222 @item -d @var{display}
224 @itemx --display=@var{display}
226 @cindex display for Emacs frame
227 Use the X Window System and use the display named @var{display} to open
228 the initial Emacs frame. @xref{Display X}, for more details.
232 @itemx --no-window-system
233 @opindex --no-window-system
234 @cindex disable window system
235 Don't communicate directly with the window system, disregarding the
236 @env{DISPLAY} environment variable even if it is set. This means that
237 Emacs uses the terminal from which it was launched for all its display
244 Run Emacs in @dfn{batch mode}. Batch mode is used for running
245 programs written in Emacs Lisp from shell scripts, makefiles, and so
246 on. To invoke a Lisp program, use the @samp{-batch} option in
247 conjunction with one or more of @samp{-l}, @samp{-f} or @samp{--eval}
248 (@pxref{Action Arguments}). @xref{Command Example}, for an example.
250 In batch mode, Emacs does not display the text being edited, and the
251 standard terminal interrupt characters such as @kbd{C-z} and @kbd{C-c}
252 have their usual effect. Emacs functions that normally print a
253 message in the echo area will print to either the standard output
254 stream (@code{stdout}) or the standard error stream (@code{stderr})
255 instead. (To be precise, functions like @code{prin1}, @code{princ}
256 and @code{print} print to @code{stdout}, while @code{message} and
257 @code{error} print to @code{stderr}.) Functions that normally read
258 keyboard input from the minibuffer take their input from the
259 terminal's standard input stream (@code{stdin}) instead.
261 @samp{--batch} implies @samp{-q} (do not load an initialization file),
262 but @file{site-start.el} is loaded nonetheless. It also causes Emacs
263 to exit after processing all the command options. In addition, it
264 disables auto-saving except in buffers for which auto-saving is
265 explicitly requested, and when saving files it omits the @code{fsync}
266 system call unless otherwise requested.
268 @item --script @var{file}
271 Run Emacs in batch mode, like @samp{--batch}, and then read and
272 execute the Lisp code in @var{file}.
274 The normal use of this option is in executable script files that run
275 Emacs. They can start with this text on the first line
278 #!/usr/bin/emacs --script
282 which will invoke Emacs with @samp{--script} and supply the name of
283 the script file as @var{file}. Emacs Lisp then treats the @samp{#!}
284 on this first line as a comment delimiter.
286 @item --no-build-details
287 @opindex --no-build-details
288 @cindex build details
289 @cindex deterministic build
290 Omit details like system name and build time from the Emacs executable,
291 so that builds are more deterministic.
295 @itemx --no-init-file
296 @opindex --no-init-file
297 @cindex bypassing init and @file{default.el} file
298 @cindex init file, not loading
299 @cindex @file{default.el} file, not loading
300 Do not load any initialization file (@pxref{Init File}). When Emacs
301 is invoked with this option, the Customize facility does not allow
302 options to be saved (@pxref{Easy Customization}). This option does
303 not disable loading @file{site-start.el}.
306 @opindex --no-site-file
307 @cindex @file{site-start.el} file, not loading
308 Do not load @file{site-start.el} (@pxref{Init File}). The @samp{-Q}
309 option does this too, but other options like @samp{-q} do not.
312 @opindex --no-site-lisp
313 @cindex @file{site-start.el} file, not loading
314 Do not include the @file{site-lisp} directories in @code{load-path}
315 (@pxref{Init File}). The @samp{-Q} option does this too.
319 @vindex inhibit-startup-screen
320 @cindex splash screen
321 @cindex startup message
322 Do not display a startup screen. You can also achieve this effect by
323 setting the variable @code{inhibit-startup-screen} to non-@code{nil}
324 in your initialization file (@pxref{Entering Emacs}).
330 Start emacs with minimum customizations. This is similar to using @samp{-q},
331 @samp{--no-site-file}, @samp{--no-site-lisp}, and @samp{--no-splash}
332 together. This also stops Emacs from processing X resources by
333 setting @code{inhibit-x-resources} to @code{t} (@pxref{Resources}).
339 Start Emacs as a daemon---after Emacs starts up, it starts the Emacs
340 server and disconnects from the terminal without opening any frames.
341 You can then use the @command{emacsclient} command to connect to Emacs
342 for editing. @xref{Emacs Server}, for information about using Emacs
345 @item -daemon=@var{SERVER-NAME}
346 Start emacs in background as a daemon, and use @var{SERVER-NAME} as
350 @opindex --no-desktop
351 Do not reload any saved desktop. @xref{Saving Emacs Sessions}.
355 @itemx --user=@var{user}
357 @cindex load init file of another user
358 Load @var{user}'s initialization file instead of your
359 own@footnote{This option has no effect on MS-Windows.}.
362 @opindex --debug-init
363 @cindex errors in init file
364 Enable the Emacs Lisp debugger for errors in the init file.
365 @xref{Error Debugging,, Entering the Debugger on an Error, elisp, The
366 GNU Emacs Lisp Reference Manual}.
369 @node Command Example
370 @appendixsec Command Argument Example
372 Here is an example of using Emacs with arguments and options. It
373 assumes you have a Lisp program file called @file{hack-c.el} which, when
374 loaded, performs some useful operation on the current buffer, expected
378 emacs --batch foo.c -l hack-c -f save-buffer >& log
382 This says to visit @file{foo.c}, load @file{hack-c.el} (which makes
383 changes in the visited file), save @file{foo.c} (note that
384 @code{save-buffer} is the function that @kbd{C-x C-s} is bound to), and
385 then exit back to the shell (because of @samp{--batch}). @samp{--batch}
386 also guarantees there will be no problem redirecting output to
387 @file{log}, because Emacs will not assume that it has a display terminal
391 @appendixsec Environment Variables
392 @cindex environment variables
394 The @dfn{environment} is a feature of the operating system; it
395 consists of a collection of variables with names and values. Each
396 variable is called an @dfn{environment variable}; environment variable
397 names are case-sensitive, and it is conventional to use upper case
398 letters only. The values are all text strings.
400 What makes the environment useful is that subprocesses inherit the
401 environment automatically from their parent process. This means you
402 can set up an environment variable in your login shell, and all the
403 programs you run (including Emacs) will automatically see it.
404 Subprocesses of Emacs (such as shells, compilers, and version control
405 programs) inherit the environment from Emacs, too.
409 @vindex initial-environment
410 Inside Emacs, the command @kbd{M-x getenv} reads the name of an
411 environment variable, and prints its value in the echo area. @kbd{M-x
412 setenv} sets a variable in the Emacs environment, and @kbd{C-u M-x
413 setenv} removes a variable. (Environment variable substitutions with
414 @samp{$} work in the value just as in file names; see @ref{File Names
415 with $}.) The variable @code{initial-environment} stores the initial
416 environment inherited by Emacs.
418 The way to set environment variables outside of Emacs depends on the
419 operating system, and especially the shell that you are using. For
420 example, here's how to set the environment variable @env{ORGANIZATION}
421 to @samp{not very much} using Bash:
424 export ORGANIZATION="not very much"
428 and here's how to do it in csh or tcsh:
431 setenv ORGANIZATION "not very much"
434 When Emacs is using the X Window System, various environment
435 variables that control X work for Emacs as well. See the X
436 documentation for more information.
439 * General Variables:: Environment variables that all versions of Emacs use.
440 * Misc Variables:: Certain system-specific variables.
441 * MS-Windows Registry:: An alternative to the environment on MS-Windows.
444 @node General Variables
445 @appendixsubsec General Variables
447 Here is an alphabetical list of environment variables that have
448 special meanings in Emacs. Most of these variables are also used by
449 some other programs. Emacs does not require any of these environment
450 variables to be set, but it uses their values if they are set.
452 @c This used to be @vtable, but that enters the variables alone into
453 @c the Variable Index, which in some cases, like HOME, might be
454 @c confused with keys by that name, and other cases, like NAME,
455 @c might be confused with general-purpose phrases.
458 @vindex CDPATH, environment variable
459 Used by the @code{cd} command to search for the directory you specify,
460 when you specify a relative directory name.
461 @item DBUS_SESSION_BUS_ADDRESS
462 @vindex DBUS_SESSION_BUS_ADDRESS, environment variable
463 Used by D-Bus when Emacs is compiled with it. Usually, there is no
464 need to change it. Setting it to a dummy address, like
465 @samp{unix:path=/dev/null}, suppresses connections to the D-Bus session
466 bus as well as autolaunching the D-Bus session bus if not running yet.
468 @vindex EMACSDATA, environment variable
469 Directory for the architecture-independent files that come with Emacs.
470 This is used to initialize the variable @code{data-directory}.
472 #vindex EMACSDOC, environment variable
473 Directory for the documentation string file, which is used to
474 initialize the Lisp variable @code{doc-directory}.
476 #vindex EMACSLOADPATH, environment variable
477 A colon-separated list of directories@footnote{Here and below,
478 whenever we say ``colon-separated list of directories'', it pertains
479 to Unix and GNU/Linux systems. On MS-DOS and MS-Windows, the
480 directories are separated by semi-colons instead, since DOS/Windows
481 file names might include a colon after a drive letter.} to search for
482 Emacs Lisp files. If set, it modifies the usual initial value of the
483 @code{load-path} variable (@pxref{Lisp Libraries}). An empty element
484 stands for the default value of @code{load-path}; e.g., using
485 @samp{EMACSLOADPATH="/tmp:"} adds @file{/tmp} to the front of
486 the default @code{load-path}. To specify an empty element in the
487 middle of the list, use 2 colons in a row, as in
488 @samp{EMACSLOADPATH="/tmp::/foo"}.
490 @vindex EMACSPATH, environment variable
491 A colon-separated list of directories to search for executable files.
492 If set, Emacs uses this in addition to @env{PATH} (see below) when
493 initializing the variable @code{exec-path} (@pxref{Shell}).
495 @vindex EMAIL, environment variable
496 @vindex user-mail-address@r{, initialization}
497 Your email address; used to initialize the Lisp variable
498 @code{user-mail-address}, which the Emacs mail interface puts into the
499 @samp{From} header of outgoing messages (@pxref{Mail Headers}).
501 @vindex ESHELL, environment variable
502 Used for shell-mode to override the @env{SHELL} environment variable
503 (@pxref{Interactive Shell}).
505 @vindex HISTFILE, environment variable
506 The name of the file that shell commands are saved in between logins.
507 This variable defaults to @file{~/.bash_history} if you use Bash, to
508 @file{~/.sh_history} if you use ksh, and to @file{~/.history}
511 @vindex HOME, environment variable
512 The location of your files in the directory tree; used for
513 expansion of file names starting with a tilde (@file{~}). On MS-DOS,
514 it defaults to the directory from which Emacs was started, with
515 @samp{/bin} removed from the end if it was present. On Windows, the
516 default value of @env{HOME} is the @file{Application Data}
517 subdirectory of the user profile directory (normally, this is
518 @file{C:/Documents and Settings/@var{username}/Application Data},
519 where @var{username} is your user name), though for backwards
520 compatibility @file{C:/} will be used instead if a @file{.emacs} file
523 @vindex HOSTNAME, environment variable
524 The name of the machine that Emacs is running on.
525 @c complete.el is obsolete since 24.1.
528 A colon-separated list of directories. Used by the @code{complete} package
532 @vindex INFOPATH, environment variable
533 A colon-separated list of directories in which to search for Info files.
535 @vindex LC_ALL, environment variable
537 @vindex LC_COLLATE, environment variable
539 @vindex LC_CTYPE, environment variable
541 @vindex LC_MESSAGES, environment variable
543 @vindex LC_MONETARY, environment variable
545 @vindex LC_NUMERIC, environment variable
547 @vindex LC_TIME, environment variable
549 @vindex LANG, environment variable
550 The user's preferred locale. The locale has six categories, specified
551 by the environment variables @env{LC_COLLATE} for sorting,
552 @env{LC_CTYPE} for character encoding, @env{LC_MESSAGES} for system
553 messages, @env{LC_MONETARY} for monetary formats, @env{LC_NUMERIC} for
554 numbers, and @env{LC_TIME} for dates and times. If one of these
555 variables is not set, the category defaults to the value of the
556 @env{LANG} environment variable, or to the default @samp{C} locale if
557 @env{LANG} is not set. But if @env{LC_ALL} is specified, it overrides
558 the settings of all the other locale environment variables.
560 On MS-Windows and OS X, if @env{LANG} is not already set in the
561 environment, Emacs sets it based on the system-wide default. You can
562 set this in the ``Regional Settings'' Control Panel on some versions
563 of MS-Windows, and in the ``Language and Region'' System Preference on
566 The value of the @env{LC_CTYPE} category is
567 matched against entries in @code{locale-language-names},
568 @code{locale-charset-language-names}, and
569 @code{locale-preferred-coding-systems}, to select a default language
570 environment and coding system. @xref{Language Environments}.
572 @vindex LOGNAME, environment variable
573 The user's login name. See also @env{USER}.
575 @vindex MAIL, environment variable
576 The name of your system mail inbox.
579 @vindex MH, environment variable
580 Name of setup file for the mh system. @xref{Top,,MH-E,mh-e, The Emacs
584 @vindex NAME, environment variable
585 Your real-world name. This is used to initialize the variable
586 @code{user-full-name} (@pxref{Mail Headers}).
588 @vindex NNTPSERVER, environment variable
589 The name of the news server. Used by the mh and Gnus packages.
591 @vindex ORGANIZATION, environment variable
592 The name of the organization to which you belong. Used for setting the
593 @samp{Organization:} header in your posts from the Gnus package.
595 @vindex PATH, environment variable
596 A colon-separated list of directories containing executable files.
597 This is used to initialize the variable @code{exec-path}
600 @vindex PWD, environment variable
601 If set, this should be the default directory when Emacs was started.
603 @vindex REPLYTO, environment variable
604 If set, this specifies an initial value for the variable
605 @code{mail-default-reply-to} (@pxref{Mail Headers}).
607 @vindex SAVEDIR, environment variable
608 The name of a directory in which news articles are saved by default.
609 Used by the Gnus package.
611 @vindex SHELL, environment variable
612 The name of an interpreter used to parse and execute programs run from
615 @vindex SMTPSERVER, environment variable
616 The name of the outgoing mail server. This is used to initialize the
617 variable @code{smtpmail-smtp-server} (@pxref{Mail Sending}).
618 @cindex background mode, on @command{xterm}
620 @vindex TERM, environment variable
621 The type of the terminal that Emacs is using. This variable must be
622 set unless Emacs is run in batch mode. On MS-DOS, it defaults to
623 @samp{internal}, which specifies a built-in terminal emulation that
624 handles the machine's own display.
626 @vindex TERMCAP, environment variable
627 The name of the termcap library file describing how to program the
628 terminal specified by @env{TERM}. This defaults to
631 @vindex TMPDIR, environment variable
633 @vindex TMP, environment variable
635 @vindex TEMP, environment variable
636 These environment variables are used to initialize the variable
637 @code{temporary-file-directory}, which specifies a directory in which
638 to put temporary files (@pxref{Backup}). Emacs tries to use
639 @env{TMPDIR} first. If that is unset, Emacs normally falls back on
640 @file{/tmp}, but on MS-Windows and MS-DOS it instead falls back on
641 @env{TMP}, then @env{TEMP}, and finally @file{c:/temp}.
643 @vindex TZ, environment variable
644 This specifies the current time zone and possibly also daylight
645 saving time information. On MS-DOS, if @env{TZ} is not set in the
646 environment when Emacs starts, Emacs defines a default value as
647 appropriate for the country code returned by DOS@. On MS-Windows, Emacs
648 does not use @env{TZ} at all.
650 @vindex USER, environment variable
651 The user's login name. See also @env{LOGNAME}. On MS-DOS, this
652 defaults to @samp{root}.
653 @item VERSION_CONTROL
654 @vindex VERSION_CONTROL, environment variable
655 Used to initialize the @code{version-control} variable (@pxref{Backup
660 @appendixsubsec Miscellaneous Variables
662 These variables are used only on particular configurations:
666 On MS-DOS and MS-Windows, the name of the command interpreter to use
667 when invoking batch files and commands internal to the shell. On MS-DOS
668 this is also used to make a default value for the @env{SHELL} environment
672 On MS-DOS, this variable defaults to the value of the @env{USER}
676 On MS-DOS, this specifies a file to use to log the operation of the
677 internal terminal emulator. This feature is useful for submitting bug
681 On MS-DOS, this specifies the screen colors. It is useful to set them
682 this way, since otherwise Emacs would display the default colors
683 momentarily when it starts up.
685 The value of this variable should be the two-character encoding of the
686 foreground (the first character) and the background (the second
687 character) colors of the default face. Each character should be the
688 hexadecimal code for the desired color on a standard PC text-mode
689 display. For example, to get blue text on a light gray background,
690 specify @samp{EMACSCOLORS=17}, since 1 is the code of the blue color and
691 7 is the code of the light gray color.
693 The PC display usually supports only eight background colors. However,
694 Emacs switches the DOS display to a mode where all 16 colors can be used
695 for the background, so all four bits of the background color are
698 @item PRELOAD_WINSOCK
699 On MS-Windows, if you set this variable, Emacs will load and initialize
700 the network library at startup, instead of waiting until the first
704 On MS-Windows, @env{emacs_dir} is a special environment variable, which
705 indicates the full path of the directory in which Emacs is installed.
706 If Emacs is installed in the standard directory structure, it
707 calculates this value automatically. It is not much use setting this
708 variable yourself unless your installation is non-standard, since
709 unlike other environment variables, it will be overridden by Emacs at
710 startup. When setting other environment variables, such as
711 @env{EMACSLOADPATH}, you may find it useful to use @env{emacs_dir}
712 rather than hard-coding an absolute path. This allows multiple
713 versions of Emacs to share the same environment variable settings, and
714 it allows you to move the Emacs installation directory, without
715 changing any environment or registry settings.
718 @node MS-Windows Registry
719 @appendixsubsec The MS-Windows System Registry
720 @pindex addpm, MS-Windows installation program
721 @cindex registry, setting environment variables (MS-Windows)
723 On MS-Windows, the installation program @command{addpm.exe} adds
724 values for @env{emacs_dir}, @env{EMACSLOADPATH}, @env{EMACSDATA},
725 @env{EMACSPATH}, @env{EMACSDOC}, @env{SHELL} and @env{TERM} to the
726 @file{HKEY_LOCAL_MACHINE} section of the system registry, under
727 @file{/Software/GNU/Emacs}. It does this because there is no standard
728 place to set environment variables across different versions of
729 Windows. Running @command{addpm.exe} is no longer strictly necessary
730 in recent versions of Emacs, but if you are upgrading from an older
731 version, running @command{addpm.exe} ensures that you do not have
732 older registry entries from a previous installation, which may not be
733 compatible with the latest version of Emacs.
735 When Emacs starts, as well as checking the environment, it also checks
736 the System Registry for those variables and for @env{HOME}, @env{LANG}
737 and @env{PRELOAD_WINSOCK}.
739 To determine the value of those variables, Emacs goes through the
740 following procedure. First, the environment is checked. If the
741 variable is not found there, Emacs looks for registry keys by that
742 name under @file{/Software/GNU/Emacs}; first in the
743 @file{HKEY_CURRENT_USER} section of the registry, and if not found
744 there, in the @file{HKEY_LOCAL_MACHINE} section. Finally, if Emacs
745 still cannot determine the values, compiled-in defaults are used.
747 In addition to the environment variables above, you can also add many
748 of the settings which on X belong in the @file{.Xdefaults} file
749 (@pxref{X Resources}) to the @file{/Software/GNU/Emacs} registry key.
752 @appendixsec Specifying the Display Name
753 @cindex display name (X Window System)
754 @cindex @env{DISPLAY} environment variable
756 The environment variable @env{DISPLAY} tells all X clients,
757 including Emacs, where to display their windows. Its value is set by
758 default in ordinary circumstances, when you start an X server and run
759 jobs locally. You can specify the display yourself; one reason to do
760 this is if you want to log into another system and run Emacs there,
761 and have the window displayed at your local terminal.
763 @env{DISPLAY} has the syntax
764 @samp{@var{host}:@var{display}.@var{screen}}, where @var{host} is the
765 host name of the X Window System server machine, @var{display} is an
766 arbitrarily-assigned number that distinguishes your server (X
767 terminal) from other servers on the same machine, and @var{screen} is
768 a field that allows an X server to control multiple terminal screens.
769 The period and the @var{screen} field are optional. If included,
770 @var{screen} is usually zero.
772 For example, if your host is named @samp{glasperle} and your server is
773 the first (or perhaps the only) server listed in the configuration, your
774 @env{DISPLAY} is @samp{glasperle:0.0}.
776 You can specify the display name explicitly when you run Emacs, either
777 by changing the @env{DISPLAY} variable, or with the option @samp{-d
778 @var{display}} or @samp{--display=@var{display}}. Here is an example:
781 emacs --display=glasperle:0 &
784 You can inhibit the use of the X window system with the @samp{-nw}
785 option. Then Emacs uses its controlling text terminal for display.
786 @xref{Initial Options}.
788 Sometimes, security arrangements prevent a program on a remote system
789 from displaying on your local system. In this case, trying to run Emacs
790 produces messages like this:
793 Xlib: connection to "glasperle:0.0" refused by server
797 You might be able to overcome this problem by using the @command{xhost}
798 command on the local system to give permission for access from your
802 @appendixsec Font Specification Options
803 @cindex font name (X Window System)
805 You can use the command line option @samp{-fn @var{font}} (or
806 @samp{--font}, which is an alias for @samp{-fn}) to specify a default
812 @itemx --font=@var{font}
814 @cindex specify default font from the command line
815 Use @var{font} as the default font.
818 When passing a font name to Emacs on the command line, you may need to
819 quote it, by enclosing it in quotation marks, if it contains
820 characters that the shell treats specially (e.g., spaces). For
824 emacs -fn "DejaVu Sans Mono-12"
827 @xref{Fonts}, for details about font names and other ways to specify
831 @appendixsec Window Color Options
832 @cindex color of window, from command line
833 @cindex text colors, from command line
835 You can use the following command-line options to specify the colors
836 to use for various parts of the Emacs display. Colors may be
837 specified using either color names or RGB triplets (@pxref{Colors}).
840 @item -fg @var{color}
842 @itemx --foreground-color=@var{color}
843 @opindex --foreground-color
844 @cindex foreground color, command-line argument
845 Specify the foreground color, overriding the color specified by the
846 @code{default} face (@pxref{Faces}).
847 @item -bg @var{color}
849 @itemx --background-color=@var{color}
850 @opindex --background-color
851 @cindex background color, command-line argument
852 Specify the background color, overriding the color specified by the
854 @item -bd @var{color}
856 @itemx --border-color=@var{color}
857 @opindex --border-color
858 @cindex border color, command-line argument
859 Specify the color of the border of the X window. This has no effect
860 if Emacs is compiled with GTK+ support.
861 @item -cr @var{color}
863 @itemx --cursor-color=@var{color}
864 @opindex --cursor-color
865 @cindex cursor color, command-line argument
866 Specify the color of the Emacs cursor which indicates where point is.
867 @item -ms @var{color}
869 @itemx --mouse-color=@var{color}
870 @opindex --mouse-color
871 @cindex mouse pointer color, command-line argument
872 Specify the color for the mouse cursor when the mouse is in the Emacs window.
877 @itemx --reverse-video
878 @opindex --reverse-video
879 @cindex reverse video, command-line argument
880 Reverse video---swap the foreground and background colors.
881 @item --color=@var{mode}
883 @cindex standard colors on a character terminal
884 @cindex override character terminal color support
885 Set the @dfn{color support mode} when Emacs is run on a text terminal.
886 This option overrides the number of supported colors that the
887 character terminal advertises in its @code{termcap} or @code{terminfo}
888 database. The parameter @var{mode} can be one of the following:
892 Don't use colors even if the terminal's capabilities specify color
896 Same as when @option{--color} is not used at all: Emacs detects at
897 startup whether the terminal supports colors, and if it does, turns on
902 Turn on the color support unconditionally, and use color commands
903 specified by the ANSI escape sequences for the 8 standard colors.
905 Use color mode for @var{num} colors. If @var{num} is -1, turn off
906 color support (equivalent to @samp{never}); if it is 0, use the
907 default color support for this terminal (equivalent to @samp{auto});
908 otherwise use an appropriate standard mode for @var{num} colors.
909 Depending on your terminal's capabilities, Emacs might be able to turn
910 on a color mode for 8, 16, 88, or 256 as the value of @var{num}. If
911 there is no mode that supports @var{num} colors, Emacs acts as if
912 @var{num} were 0, i.e., it uses the terminal's default color support
915 If @var{mode} is omitted, it defaults to @var{ansi8}.
918 For example, to use a coral mouse cursor and a slate blue text cursor,
922 emacs -ms coral -cr 'slate blue' &
925 You can reverse the foreground and background colors through the
926 @samp{-rv} option or with the X resource @samp{reverseVideo}.
928 The @samp{-fg}, @samp{-bg}, and @samp{-rv} options function on text
929 terminals as well as on graphical displays.
932 @appendixsec Options for Window Size and Position
933 @cindex geometry of Emacs window
934 @cindex position and size of Emacs frame
935 @cindex width and height of Emacs frame
936 @cindex specifying fullscreen for Emacs frame
938 Here is a list of the command-line options for specifying size and
939 position of the initial Emacs frame:
942 @item -g @var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
944 @itemx --geometry=@var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
946 @cindex geometry, command-line argument
947 Specify the size @var{width} and @var{height} (measured in character
948 columns and lines), and positions @var{xoffset} and @var{yoffset}
949 (measured in pixels). The @var{width} and @var{height} parameters
950 apply to all frames, whereas @var{xoffset} and @var{yoffset} only to
956 @opindex --fullscreen
957 @cindex fullscreen, command-line argument
958 Specify that width and height should be that of the screen. Normally
959 no window manager decorations are shown. (After starting Emacs,
960 you can toggle this state using @key{F11}, @code{toggle-frame-fullscreen}.)
966 @cindex maximized, command-line argument
967 Specify that the Emacs frame should be maximized. This normally
968 means that the frame has window manager decorations.
969 (After starting Emacs, you can toggle this state using @kbd{M-F10},
970 @code{toggle-frame-maximized}.)
975 @opindex --fullheight
976 @cindex fullheight, command-line argument
977 Specify that the height should be the height of the screen.
983 @cindex fullwidth, command-line argument
984 Specify that the width should be the width of the screen.
988 In the @samp{--geometry} option, @code{@r{@{}+-@r{@}}} means either a plus
989 sign or a minus sign. A plus
990 sign before @var{xoffset} means it is the distance from the left side of
991 the screen; a minus sign means it counts from the right side. A plus
992 sign before @var{yoffset} means it is the distance from the top of the
993 screen, and a minus sign there indicates the distance from the bottom.
994 The values @var{xoffset} and @var{yoffset} may themselves be positive or
995 negative, but that doesn't change their meaning, only their direction.
997 Emacs uses the same units as @command{xterm} does to interpret the geometry.
998 The @var{width} and @var{height} are measured in characters, so a large font
999 creates a larger frame than a small font. (If you specify a proportional
1000 font, Emacs uses its maximum bounds width as the width unit.) The
1001 @var{xoffset} and @var{yoffset} are measured in pixels.
1003 You do not have to specify all of the fields in the geometry
1004 specification. If you omit both @var{xoffset} and @var{yoffset}, the
1005 window manager decides where to put the Emacs frame, possibly by
1006 letting you place it with the mouse. For example, @samp{164x55}
1007 specifies a window 164 columns wide, enough for two ordinary width
1008 windows side by side, and 55 lines tall.
1010 The default frame width is 80 characters and the default height is
1011 40 lines. You can omit either the width or the height or both. If
1012 you start the geometry with an integer, Emacs interprets it as the
1013 width. If you start with an @samp{x} followed by an integer, Emacs
1014 interprets it as the height. Thus, @samp{81} specifies just the
1015 width; @samp{x45} specifies just the height.
1017 If you start with @samp{+} or @samp{-}, that introduces an offset,
1018 which means both sizes are omitted. Thus, @samp{-3} specifies the
1019 @var{xoffset} only. (If you give just one offset, it is always
1020 @var{xoffset}.) @samp{+3-3} specifies both the @var{xoffset} and the
1021 @var{yoffset}, placing the frame near the bottom left of the screen.
1023 You can specify a default for any or all of the fields in your X
1024 resource file (@pxref{Resources}), and then override selected fields
1025 with a @samp{--geometry} option.
1027 Since the mode line and the echo area occupy the last 2 lines of the
1028 frame, the height of the initial text window is 2 less than the height
1029 specified in your geometry. In non-X-toolkit versions of Emacs, the
1030 menu bar also takes one line of the specified number. But in the X
1031 toolkit version, the menu bar is additional and does not count against
1032 the specified height. The tool bar, if present, is also additional.
1034 Enabling or disabling the menu bar or tool bar alters the amount of
1035 space available for ordinary text. Therefore, if Emacs starts up with
1036 a tool bar (which is the default), and handles the geometry
1037 specification assuming there is a tool bar, and then your
1038 initialization file disables the tool bar, you will end up with a
1039 frame geometry different from what you asked for. To get the intended
1040 size with no tool bar, use an X resource to specify ``no tool bar''
1041 (@pxref{Table of Resources}); then Emacs will already know there's no
1042 tool bar when it processes the specified geometry.
1044 When using one of @samp{--fullscreen}, @samp{--maximized},
1045 @samp{--fullwidth} or @samp{--fullheight}, some window managers require
1046 you to set the variable @code{frame-resize-pixelwise} to a non-@code{nil}
1047 value to make a frame appear truly maximized or full-screen.
1049 Some window managers have options that can make them ignore both
1050 program-specified and user-specified positions. If these are set,
1051 Emacs fails to position the window correctly.
1054 @appendixsec Internal and External Borders
1055 @cindex borders (X Window System)
1057 An Emacs frame has an internal border and an external border. The
1058 internal border is an extra strip of the background color around the
1059 text portion of the frame. Emacs itself draws the internal border.
1060 The external border is added by the window manager outside the frame;
1061 depending on the window manager you use, it may contain various boxes
1062 you can click on to move or iconify the window.
1065 @item -ib @var{width}
1067 @itemx --internal-border=@var{width}
1068 @opindex --internal-border
1069 @cindex internal border width, command-line argument
1070 Specify @var{width} as the width of the internal border (between the text
1071 and the main border), in pixels.
1073 @item -bw @var{width}
1075 @itemx --border-width=@var{width}
1076 @opindex --border-width
1077 @cindex main border width, command-line argument
1078 Specify @var{width} as the width of the main border, in pixels.
1081 When you specify the size of the frame, that does not count the
1082 borders. The frame's position is measured from the outside edge of the
1085 Use the @samp{-ib @var{n}} option to specify an internal border
1086 @var{n} pixels wide. The default is 1. Use @samp{-bw @var{n}} to
1087 specify the width of the external border (though the window manager may
1088 not pay attention to what you specify). The default width of the
1089 external border is 2.
1092 @appendixsec Frame Titles
1094 An Emacs frame may or may not have a specified title. The frame
1095 title, if specified, appears in window decorations and icons as the
1096 name of the frame. If an Emacs frame has no specified title, the
1097 default title has the form @samp{@var{invocation-name}@@@var{machine}}
1098 (if there is only one frame) or the selected window's buffer name (if
1099 there is more than one frame).
1101 You can specify a title for the initial Emacs frame with a command
1105 @item -T @var{title}
1107 @itemx --title=@var{title}
1109 @cindex frame title, command-line argument
1110 Specify @var{title} as the title for the initial Emacs frame.
1113 The @samp{--name} option (@pxref{Resources}) also specifies the title
1114 for the initial Emacs frame.
1118 @cindex icons (X Window System)
1119 @cindex minimizing a frame at startup
1125 @cindex start iconified, command-line argument
1126 Start Emacs in an iconified state.
1130 @itemx --no-bitmap-icon
1131 @opindex --no-bitmap-icon
1132 @cindex Emacs icon, a gnu
1133 Disable the use of the Emacs icon.
1136 Most window managers allow you to iconify (or ``minimize'') an
1137 Emacs frame, hiding it from sight. Some window managers replace
1138 iconified windows with tiny icons, while others remove them
1139 entirely from sight. The @samp{-iconic} option tells Emacs to begin
1140 running in an iconified state, rather than showing a frame right away.
1141 The text frame doesn't appear until you deiconify (or ``un-minimize'')
1144 By default, Emacs uses an icon containing the Emacs logo. On
1145 desktop environments such as Gnome, this icon is also displayed in
1146 other contexts, e.g., when switching into an Emacs frame. The
1147 @samp{-nbi} or @samp{--no-bitmap-icon} option tells Emacs to let the
1148 window manager choose what sort of icon to use---usually just a small
1149 rectangle containing the frame's title.
1152 @appendixsec Other Display Options
1157 @c @itemx --horizontal-scroll-bars
1158 @c @opindex --horizontal-scroll-bars
1159 @c @c @cindex horizontal scroll bars, command-line argument
1160 @c Enable horizontal scroll bars. Since horizontal scroll bars
1161 @c are not yet implemented, this actually does nothing.
1163 @item --parent-id @var{id}
1164 Open Emacs as a client X window via the XEmbed protocol, with @var{id}
1165 as the parent X window id. Currently, this option is mainly useful
1170 @itemx --vertical-scroll-bars
1171 @opindex --vertical-scroll-bars
1172 @cindex vertical scroll bars, command-line argument
1173 Enable vertical scroll bars.
1175 @item -lsp @var{pixels}
1177 @itemx --line-spacing=@var{pixels}
1178 @opindex --line-spacing
1179 @cindex line spacing, command-line argument
1180 Specify @var{pixels} as additional space to put between lines, in pixels.
1184 @itemx --no-blinking-cursor
1185 @opindex --no-blinking-cursor
1186 @cindex blinking cursor disable, command-line argument
1187 Disable the blinking cursor on graphical displays.
1191 @itemx --basic-display
1192 @opindex --basic-display
1193 Disable the menu-bar, the tool-bar, the scroll-bars, and tool tips,
1194 and turn off the blinking cursor. This can be useful for making a
1195 test case that simplifies debugging of display problems.
1198 The @samp{--xrm} option (@pxref{Resources}) specifies additional