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1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985,86,87,93,94,95,1997,2001 Free Software Foundation, Inc.
3 @c See file emacs.texi for copying conditions.
4 @node Command Arguments, X Resources, Service, Top
5 @appendix Command Line Arguments
6 @cindex command line arguments
7 @cindex arguments (command line)
8 @cindex options (command line)
9 @cindex switches (command line)
10 @cindex startup (command line arguments)
11
12 GNU Emacs supports command line arguments to request various actions
13 when invoking Emacs. These are for compatibility with other editors and
14 for sophisticated activities. We don't recommend using them for
15 ordinary editing.
16
17 Arguments starting with @samp{-} are @dfn{options}. Other arguments
18 specify files to visit. Emacs visits the specified files while it
19 starts up. The last file name on your command line becomes the
20 current buffer; the other files are also visited in other buffers. If
21 there are two files, they are both displayed; otherwise the last file
22 is displayed along with a buffer list that shows what other buffers
23 there are. As with most programs, the special argument @samp{--} says
24 that all subsequent arguments are file names, not options, even if
25 they start with @samp{-}.
26
27 Emacs command options can specify many things, such as the size and
28 position of the X window Emacs uses, its colors, and so on. A few
29 options support advanced usage, such as running Lisp functions on files
30 in batch mode. The sections of this chapter describe the available
31 options, arranged according to their purpose.
32
33 There are two ways of writing options: the short forms that start with
34 a single @samp{-}, and the long forms that start with @samp{--}. For
35 example, @samp{-d} is a short form and @samp{--display} is the
36 corresponding long form.
37
38 The long forms with @samp{--} are easier to remember, but longer to
39 type. However, you don't have to spell out the whole option name; any
40 unambiguous abbreviation is enough. When a long option takes an
41 argument, you can use either a space or an equal sign to separate the
42 option name and the argument. Thus, you can write either
43 @samp{--display sugar-bombs:0.0} or @samp{--display=sugar-bombs:0.0}.
44 We recommend an equal sign because it makes the relationship clearer,
45 and the tables below always show an equal sign.
46
47 @cindex initial options (command line)
48 @cindex action options (command line)
49 Most options specify how to initialize Emacs, or set parameters for
50 the Emacs session. We call them @dfn{initial options}. A few options
51 specify things to do: for example, load libraries, call functions, or
52 terminate Emacs. These are called @dfn{action options}. These and file
53 names together are called @dfn{action arguments}. Emacs processes all
54 the action arguments in the order they are written.
55
56 @menu
57 * Action Arguments:: Arguments to visit files, load libraries,
58 and call functions.
59 * Initial Options:: Arguments that take effect while starting Emacs.
60 * Command Example:: Examples of using command line arguments.
61 * Resume Arguments:: Specifying arguments when you resume a running Emacs.
62 * Environment:: Environment variables that Emacs uses.
63 * Display X:: Changing the default display and using remote login.
64 * Font X:: Choosing a font for text, under X.
65 * Colors:: Choosing display colors.
66 * Window Size X:: Start-up window size, under X.
67 * Borders X:: Internal and external borders, under X.
68 * Title X:: Specifying the initial frame's title.
69 * Icons X:: Choosing what sort of icon to use, under X.
70 @end menu
71
72 @node Action Arguments
73 @appendixsec Action Arguments
74
75 Here is a table of the action arguments and options:
76
77 @table @samp
78 @item @var{file}
79 @opindex --visit
80 @itemx --visit=@var{file}
81 @opindex --file
82 @itemx --file=@var{file}
83 @cindex visiting files, command-line argument
84 @vindex inhibit-startup-buffer-menu
85 Visit @var{file} using @code{find-file}. @xref{Visiting}.
86 If you visit several files at startup in this way, Emacs
87 also displays a Buffer Menu buffer to show you what files it
88 has visited. You can inhibit that by setting @code{inhibit-startup-buffer-menu} to @code{t}.
89
90 @item +@var{linenum} @var{file}
91 @opindex +@var{linenum}
92 Visit @var{file} using @code{find-file}, then go to line number
93 @var{linenum} in it.
94
95 @item +@var{linenum}:@var{columnnum} @var{file}
96 Visit @var{file} using @code{find-file}, then go to line number
97 @var{linenum} and put point at column number @var{columnnum}.
98
99 @need 3000
100 @item -l @var{file}
101 @opindex -l
102 @itemx --load=@var{file}
103 @opindex --load
104 @cindex loading Lisp libraries, command-line argument
105 Load a Lisp library named @var{file} with the function @code{load}.
106 @xref{Lisp Libraries}. The library can be found either in the current
107 directory, or in the Emacs library search path as specified
108 with @env{EMACSLOADPATH} (@pxref{General Variables}).
109
110 @item -f @var{function}
111 @opindex -f
112 @itemx --funcall=@var{function}
113 @opindex --funcall
114 @cindex call Lisp functions, command-line argument
115 Call Lisp function @var{function} with no arguments.
116
117 @item --eval=@var{expression}
118 @opindex --eval
119 @itemx --execute=@var{expression}
120 @opindex --execute
121 @cindex evaluate expression, command-line argument
122 Evaluate Lisp expression @var{expression}.
123
124 @item --insert=@var{file}
125 @opindex --insert
126 @cindex insert file contents, command-line argument
127 Insert the contents of @var{file} into the current buffer. This is like
128 what @kbd{M-x insert-file} does. @xref{Misc File Ops}.
129
130 @item --kill
131 @opindex --kill
132 Exit from Emacs without asking for confirmation.
133 @end table
134
135 @vindex command-line-args
136 The init file can access the values of the action arguments as the
137 elements of a list in the variable @code{command-line-args}. The init
138 file can override the normal processing of the action arguments, or
139 define new ones, by reading and setting this variable.
140
141 @node Initial Options
142 @appendixsec Initial Options
143
144 The initial options specify parameters for the Emacs session. This
145 section describes the more general initial options; some other options
146 specifically related to the X Window System appear in the following
147 sections.
148
149 Some initial options affect the loading of init files. The normal
150 actions of Emacs are to first load @file{site-start.el} if it exists,
151 then your own init file @file{~/.emacs} if it exists, and finally
152 @file{default.el} if it exists; certain options prevent loading of some
153 of these files or substitute other files for them.
154
155 @table @samp
156 @item -t @var{device}
157 @opindex -t
158 @itemx --terminal=@var{device}
159 @opindex --terminal
160 @cindex device for Emacs terminal I/O
161 Use @var{device} as the device for terminal input and output.
162
163 @item -d @var{display}
164 @opindex -d
165 @itemx --display=@var{display}
166 @opindex --display
167 @cindex display for Emacs frame
168 Use the X Window System and use the display named @var{display} to open
169 the initial Emacs frame. @xref{Display X}, for more details.
170
171 @item -nw
172 @opindex -nw
173 @itemx --no-window-system
174 @opindex --no-window-system
175 @cindex disable window system
176 Don't communicate directly with the window system, disregarding the
177 @env{DISPLAY} environment variable even if it is set. This means that
178 Emacs uses the terminal from which it was launched for all its display
179 and input.
180
181 @need 3000
182 @cindex batch mode
183 @item -batch
184 @opindex --batch
185 @itemx --batch
186 Run Emacs in @dfn{batch mode}, which means that the text being edited is
187 not displayed and the standard terminal interrupt characters such as
188 @kbd{C-z} and @kbd{C-c} continue to have their normal effect. Emacs in
189 batch mode outputs to @code{stderr} only what would normally be displayed
190 in the echo area under program control, and functions which would
191 normally read from the minibuffer take their input from @code{stdin}.
192
193 Batch mode is used for running programs written in Emacs Lisp from
194 shell scripts, makefiles, and so on. Normally the @samp{-l} option
195 or @samp{-f} option will be used as well, to invoke a Lisp program
196 to do the batch processing.
197
198 @samp{--batch} implies @samp{-q} (do not load an init file). It also
199 causes Emacs to exit after processing all the command options. In
200 addition, it disables auto-saving except in buffers for which it has
201 been explicitly requested.
202
203 @item --script @var{file}
204 @opindex --script
205 Run Emacs in batch mode, like @samp{--batch}, and then read and
206 execute the Lisp code in @var{file}.
207
208 The normal use of this option is in executable script files that run
209 Emacs. They can start with this text on the first line
210
211 @example
212 #!/usr/bin/emacs --script
213 @end example
214
215 @noindent
216 which will invoke Emacs with @samp{--script} and supply the name of
217 the script file as @var{file}. Emacs Lisp then treats @samp{#!} as a
218 comment delimiter.
219
220 @item -q
221 @opindex -q
222 @itemx --no-init-file
223 @opindex --no-init-file
224 @cindex bypassing init and site-start file
225 @cindex init file, not loading
226 @cindex @file{default.el} file, not loading
227 Do not load your Emacs init file @file{~/.emacs}, or @file{default.el}
228 either. When invoked like this, Emacs does not allow saving options
229 changed with the @kbd{M-x customize} command and its variants.
230 @xref{Easy Customization}.
231
232 @item --no-site-file
233 @opindex --no-site-file
234 @cindex @file{site-start.el} file, not loading
235 Do not load @file{site-start.el}. The options @samp{-q}, @samp{-u}
236 and @samp{-batch} have no effect on the loading of this file---this is
237 the only option that blocks it.
238
239 @item --no-splash
240 @opindex --no-splash
241 @vindex inhibit-startup-message
242 Do not display a splash screen on startup; this is equivalent to
243 setting the variable @code{inhibit-startup-message} to non-@code{nil}.
244
245 @item -u @var{user}
246 @opindex -u
247 @itemx --user=@var{user}
248 @opindex --user
249 @cindex load init file of another user
250 Load @var{user}'s Emacs init file @file{~@var{user}/.emacs} instead of
251 your own.
252
253 @item --debug-init
254 @opindex --debug-init
255 @cindex errors in init file
256 Enable the Emacs Lisp debugger for errors in the init file.
257
258 @item --unibyte
259 @opindex --unibyte
260 @cindex unibyte operation, command-line argument
261 Do almost everything with single-byte buffers and strings.
262 All buffers and strings are unibyte unless you (or a Lisp program)
263 explicitly ask for a multibyte buffer or string. (Note that Emacs
264 always loads Lisp files in multibyte mode, even if @samp{--unibyte} is
265 specified; see @ref{Enabling Multibyte}.) Setting the environment
266 variable @env{EMACS_UNIBYTE} has the same effect.
267
268 @item --multibyte
269 @opindex --multibyte
270 Inhibit the effect of @env{EMACS_UNIBYTE}, so that Emacs
271 uses multibyte characters by default, as usual.
272 @end table
273
274 @node Command Example
275 @appendixsec Command Argument Example
276
277 Here is an example of using Emacs with arguments and options. It
278 assumes you have a Lisp program file called @file{hack-c.el} which, when
279 loaded, performs some useful operation on the current buffer, expected
280 to be a C program.
281
282 @example
283 emacs -batch foo.c -l hack-c -f save-buffer >& log
284 @end example
285
286 @noindent
287 This says to visit @file{foo.c}, load @file{hack-c.el} (which makes
288 changes in the visited file), save @file{foo.c} (note that
289 @code{save-buffer} is the function that @kbd{C-x C-s} is bound to), and
290 then exit back to the shell (because of @samp{-batch}). @samp{-batch}
291 also guarantees there will be no problem redirecting output to
292 @file{log}, because Emacs will not assume that it has a display terminal
293 to work with.
294
295 @node Resume Arguments
296 @appendixsec Resuming Emacs with Arguments
297
298 You can specify action arguments for Emacs when you resume it after
299 a suspension. To prepare for this, put the following code in your
300 @file{.emacs} file (@pxref{Hooks}):
301
302 @c `resume-suspend-hook' is correct. It is the name of a function.
303 @example
304 (add-hook 'suspend-hook 'resume-suspend-hook)
305 (add-hook 'suspend-resume-hook 'resume-process-args)
306 @end example
307
308 As further preparation, you must execute the shell script
309 @file{emacs.csh} (if you use csh as your shell) or @file{emacs.bash}
310 (if you use bash as your shell). These scripts define an alias named
311 @code{edit}, which will resume Emacs giving it new command line
312 arguments such as files to visit. The scripts are found in the
313 @file{etc} subdirectory of the Emacs distribution.
314
315 Only action arguments work properly when you resume Emacs. Initial
316 arguments are not recognized---it's too late to execute them anyway.
317
318 Note that resuming Emacs (with or without arguments) must be done from
319 within the shell that is the parent of the Emacs job. This is why
320 @code{edit} is an alias rather than a program or a shell script. It is
321 not possible to implement a resumption command that could be run from
322 other subjobs of the shell; there is no way to define a command that could
323 be made the value of @env{EDITOR}, for example. Therefore, this feature
324 does not take the place of the Emacs Server feature (@pxref{Emacs
325 Server}).
326
327 The aliases use the Emacs Server feature if you appear to have a
328 server Emacs running. However, they cannot determine this with complete
329 accuracy. They may think that a server is still running when in
330 actuality you have killed that Emacs, because the file
331 @file{/tmp/esrv@dots{}} still exists. If this happens, find that
332 file and delete it.
333
334 @node Environment
335 @appendixsec Environment Variables
336 @cindex environment variables
337
338 The @dfn{environment} is a feature of the operating system; it
339 consists of a collection of variables with names and values. Each
340 variable is called an @dfn{environment variable}; environment variable
341 names are case-sensitive, and it is conventional to use upper case
342 letters only. The values are all text strings.
343
344 What makes the environment useful is that subprocesses inherit the
345 environment automatically from their parent process. This means you
346 can set up an environment variable in your login shell, and all the
347 programs you run (including Emacs) will automatically see it.
348 Subprocesses of Emacs (such as shells, compilers, and version-control
349 software) inherit the environment from Emacs, too.
350
351 @findex setenv
352 @findex getenv
353 Inside Emacs, the command @kbd{M-x getenv} gets the value of an
354 environment variable. @kbd{M-x setenv} sets a variable in the Emacs
355 environment. (Environment variable substitutions with @samp{$} work
356 in the value just as in file names; see @ref{File Names with $}.)
357
358 The way to set environment variables outside of Emacs depends on the
359 operating system, and especially the shell that you are using. For
360 example, here's how to set the environment variable @env{ORGANIZATION}
361 to @samp{not very much} using Bash:
362
363 @example
364 export ORGANIZATION="not very much"
365 @end example
366
367 @noindent
368 and here's how to do it in csh or tcsh:
369
370 @example
371 setenv ORGANIZATION "not very much"
372 @end example
373
374 When Emacs is using the X Window System, various environment
375 variables that control X work for Emacs as well. See the X
376 documentation for more information.
377
378 @menu
379 * General Variables:: Environment variables that all versions of Emacs use.
380 * Misc Variables:: Certain system-specific variables.
381 * MS-Windows Registry:: An alternative to the environment on MS-Windows.
382 @end menu
383
384 @node General Variables
385 @appendixsubsec General Variables
386
387 Here is an alphabetical list of specific environment variables that
388 have special meanings in Emacs, giving the name of each variable and
389 its meaning. Most of these variables are also used by some other
390 programs. Emacs does not require any of these environment variables
391 to be set, but it uses their values if they are set.
392
393 @table @env
394 @item CDPATH
395 Used by the @code{cd} command to search for the directory you specify,
396 when you specify a relative directory name.
397 @item EMACS_UNIBYTE
398 @cindex unibyte operation, environment variable
399 Defining this environment variable with a nonempty value directs Emacs
400 to do almost everything with single-byte buffers and strings. It is
401 equivalent to using the @samp{--unibyte} command-line option on each
402 invocation. @xref{Initial Options}.
403 @item EMACSDATA
404 Directory for the architecture-independent files that come with Emacs.
405 This is used to initialize the Lisp variable @code{data-directory}.
406 @item EMACSDOC
407 Directory for the documentation string file,
408 @file{DOC-@var{emacsversion}}. This is used to initialize the Lisp
409 variable @code{doc-directory}.
410 @item EMACSLOADPATH
411 A colon-separated list of directories@footnote{
412 Here and below, whenever we say ``colon-separated list of directories'',
413 it pertains to Unix and GNU/Linux systems. On MS-DOS and MS-Windows,
414 the directories are separated by semi-colons instead, since DOS/Windows
415 file names might include a colon after a drive letter.}
416 to search for Emacs Lisp files---used to initialize @code{load-path}.
417 @item EMACSPATH
418 A colon-separated list of directories to search for executable
419 files---used to initialize @code{exec-path}.
420 @item ESHELL
421 Used for shell-mode to override the @env{SHELL} environment variable.
422 @item HISTFILE
423 The name of the file that shell commands are saved in between logins.
424 This variable defaults to @file{~/.bash_history} if you use Bash, to
425 @file{~/.sh_history} if you use ksh, and to @file{~/.history}
426 otherwise.
427 @item HOME
428 The location of the user's files in the directory tree; used for
429 expansion of file names starting with a tilde (@file{~}). On MS-DOS, it
430 defaults to the directory from which Emacs was started, with @samp{/bin}
431 removed from the end if it was present. On Windows, the default value
432 of @env{HOME} is @file{C:/}, the root directory of drive @file{C:}.
433 @item HOSTNAME
434 The name of the machine that Emacs is running on.
435 @item INCPATH
436 A colon-separated list of directories. Used by the @code{complete} package
437 to search for files.
438 @item INFOPATH
439 A colon-separated list of directories in which to search for Info files.
440 @item LC_ALL
441 @itemx LC_COLLATE
442 @itemx LC_CTYPE
443 @itemx LC_MESSAGES
444 @itemx LC_MONETARY
445 @itemx LC_NUMERIC
446 @itemx LC_TIME
447 @itemx LANG
448 The user's preferred locale. The locale has six categories, specified
449 by the environment variables @env{LC_COLLATE} for sorting,
450 @env{LC_CTYPE} for character encoding, @env{LC_MESSAGES} for system
451 messages, @env{LC_MONETARY} for monetary formats, @env{LC_NUMERIC} for
452 numbers, and @env{LC_TIME} for dates and times. If one of these
453 variables is not set, the category defaults to the value of the
454 @env{LANG} environment variable, or to the default @samp{C} locale if
455 @env{LANG} is not set. But if @env{LC_ALL} is specified, it overrides
456 the settings of all the other locale environment variables.
457
458 On MS-Windows, if @env{LANG} is not already set in the environment
459 when Emacs starts, Emacs sets it based on the system-wide default
460 language, which you can set in the @samp{Regional Settings} Control Panel
461 on some versions of MS-Windows.
462
463 The value of the @env{LC_CTYPE} category is
464 matched against entries in @code{locale-language-names},
465 @code{locale-charset-language-names}, and
466 @code{locale-preferred-coding-systems}, to select a default language
467 environment and coding system. @xref{Language Environments}.
468 @item LOGNAME
469 The user's login name. See also @env{USER}.
470 @item MAIL
471 The name of the user's system mail inbox.
472 @item MAILRC
473 Name of file containing mail aliases. (The default is
474 @file{~/.mailrc}.)
475 @item MH
476 Name of setup file for the mh system. (The default is @file{~/.mh_profile}.)
477 @item NAME
478 The real-world name of the user.
479 @item NNTPSERVER
480 The name of the news server. Used by the mh and Gnus packages.
481 @item ORGANIZATION
482 The name of the organization to which you belong. Used for setting the
483 `Organization:' header in your posts from the Gnus package.
484 @item PATH
485 A colon-separated list of directories in which executables reside. This
486 is used to initialize the Emacs Lisp variable @code{exec-path}.
487 @item PWD
488 If set, this should be the default directory when Emacs was started.
489 @item REPLYTO
490 If set, this specifies an initial value for the variable
491 @code{mail-default-reply-to}. @xref{Mail Headers}.
492 @item SAVEDIR
493 The name of a directory in which news articles are saved by default.
494 Used by the Gnus package.
495 @item SHELL
496 The name of an interpreter used to parse and execute programs run from
497 inside Emacs.
498 @cindex background mode, on @command{xterm}
499 @item TERM
500 The type of the terminal that Emacs is using. This variable must be
501 set unless Emacs is run in batch mode. On MS-DOS, it defaults to
502 @samp{internal}, which specifies a built-in terminal emulation that
503 handles the machine's own display. If the value of @env{TERM} indicates
504 that Emacs runs in non-windowed mode from @command{xterm} or a similar
505 terminal emulator, the background mode defaults to @samp{light}, and
506 Emacs will choose colors that are appropriate for a light background.
507 @item TERMCAP
508 The name of the termcap library file describing how to program the
509 terminal specified by the @env{TERM} variable. This defaults to
510 @file{/etc/termcap}.
511 @item TMPDIR
512 Used by the Emerge package as a prefix for temporary files.
513 @item TZ
514 This specifies the current time zone and possibly also daylight
515 saving time information. On MS-DOS, if @env{TZ} is not set in the
516 environment when Emacs starts, Emacs defines a default value as
517 appropriate for the country code returned by DOS. On MS-Windows, Emacs
518 does not use @env{TZ} at all.
519 @item USER
520 The user's login name. See also @env{LOGNAME}. On MS-DOS, this
521 defaults to @samp{root}.
522 @item VERSION_CONTROL
523 Used to initialize the @code{version-control} variable (@pxref{Backup
524 Names}).
525 @end table
526
527 @node Misc Variables
528 @appendixsubsec Miscellaneous Variables
529
530 These variables are used only on particular configurations:
531
532 @table @env
533 @item COMSPEC
534 On MS-DOS and MS-Windows, the name of the command interpreter to use
535 when invoking batch files and commands internal to the shell. On MS-DOS
536 this is also used to make a default value for the @env{SHELL} environment
537 variable.
538
539 @item NAME
540 On MS-DOS, this variable defaults to the value of the @env{USER}
541 variable.
542
543 @item TEMP
544 @itemx TMP
545 On MS-DOS and MS-Windows, these specify the name of the directory for
546 storing temporary files in.
547
548 @item EMACSTEST
549 On MS-DOS, this specifies a file to use to log the operation of the
550 internal terminal emulator. This feature is useful for submitting bug
551 reports.
552
553 @item EMACSCOLORS
554 On MS-DOS, this specifies the screen colors. It is useful to set them
555 this way, since otherwise Emacs would display the default colors
556 momentarily when it starts up.
557
558 The value of this variable should be the two-character encoding of the
559 foreground (the first character) and the background (the second
560 character) colors of the default face. Each character should be the
561 hexadecimal code for the desired color on a standard PC text-mode
562 display. For example, to get blue text on a light gray background,
563 specify @samp{EMACSCOLORS=17}, since 1 is the code of the blue color and
564 7 is the code of the light gray color.
565
566 The PC display usually supports only eight background colors. However,
567 Emacs switches the DOS display to a mode where all 16 colors can be used
568 for the background, so all four bits of the background color are
569 actually used.
570
571 @item WINDOW_GFX
572 Used when initializing the Sun windows system.
573
574 @item PRELOAD_WINSOCK
575 On MS-Windows, if you set this variable, Emacs will load and initialize
576 the network library at startup, instead of waiting until the first
577 time it is required.
578
579 @item emacs_dir
580 On MS-Windows, @env{emacs_dir} is a special environment variable, which
581 indicates the full path of the directory in which Emacs is installed.
582 If Emacs is installed in the standard directory structure, it
583 calculates this value automatically. It is not much use setting this
584 variable yourself unless your installation is non-standard, since
585 unlike other environment variables, it will be overridden by Emacs at
586 startup. When setting other environment variables, such as
587 @env{EMACSLOADPATH}, you may find it useful to use @env{emacs_dir}
588 rather than hard-coding an absolute path. This allows multiple
589 versions of Emacs to share the same environment variable settings, and
590 it allows you to move the Emacs installation directory, without
591 changing any environment or registry settings.
592 @end table
593
594 @node MS-Windows Registry
595 @appendixsubsec The MS-Windows System Registry
596 @pindex addpm, MS-Windows installation program
597 @cindex registry, setting environment variables and resources on MS-Windows
598
599 On MS-Windows, the installation program @command{addpm.exe} adds values
600 for @env{emacs_dir}, @env{EMACSLOADPATH}, @env{EMACSDATA},
601 @env{EMACSPATH}, @env{EMACSDOC}, @env{SHELL} and @env{TERM} to the
602 @file{HKEY_LOCAL_MACHINE} section of the system registry, under
603 @file{/Software/GNU/Emacs}. It does this because there is no standard
604 place to set environment variables across different versions of
605 Windows. Running @command{addpm.exe} is no longer strictly
606 necessary in recent versions of Emacs, but if you are upgrading from
607 an older version, running @command{addpm.exe} ensures that you do not have
608 older registry entries from a previous installation, which may not be
609 compatible with the latest version of Emacs.
610
611 When Emacs starts, as well as checking the environment, it also checks
612 the System Registry for those variables and for @env{HOME}, @env{LANG}
613 and @env{PRELOAD_WINSOCK}.
614
615 To determine the value of those variables, Emacs goes through the
616 following procedure. First, the environment is checked. If the
617 variable is not found there, Emacs looks for registry keys by that
618 name under @file{/Software/GNU/Emacs}; first in the
619 @file{HKEY_CURRENT_USER} section of the registry, and if not found
620 there, in the @file{HKEY_LOCAL_MACHINE} section. Finally, if Emacs
621 still cannot determine the values, compiled-in defaults are used.
622
623 In addition to the environment variables above, you can also add many
624 of the settings which on X belong in the @file{.Xdefaults} file
625 (@pxref{X Resources}) to the @file{/Software/GNU/Emacs} registry key.
626 Settings you add to the @file{HKEY_LOCAL_MACHINE} section will affect
627 all users of the machine. Settings you add to the
628 @file{HKEY_CURRENT_USER} section will only affect you, and will
629 override machine wide settings.
630
631 @node Display X
632 @appendixsec Specifying the Display Name
633 @cindex display name (X Window System)
634 @cindex @env{DISPLAY} environment variable
635
636 The environment variable @env{DISPLAY} tells all X clients, including
637 Emacs, where to display their windows. Its value is set by default
638 in ordinary circumstances, when you start an X server and run jobs
639 locally. Occasionally you may need to specify the display yourself; for
640 example, if you do a remote login and want to run a client program
641 remotely, displaying on your local screen.
642
643 With Emacs, the main reason people change the default display is to
644 let them log into another system, run Emacs on that system, but have the
645 window displayed at their local terminal. You might need to log in
646 to another system because the files you want to edit are there, or
647 because the Emacs executable file you want to run is there.
648
649 The syntax of the @env{DISPLAY} environment variable is
650 @samp{@var{host}:@var{display}.@var{screen}}, where @var{host} is the
651 host name of the X Window System server machine, @var{display} is an
652 arbitrarily-assigned number that distinguishes your server (X terminal)
653 from other servers on the same machine, and @var{screen} is a
654 rarely-used field that allows an X server to control multiple terminal
655 screens. The period and the @var{screen} field are optional. If
656 included, @var{screen} is usually zero.
657
658 For example, if your host is named @samp{glasperle} and your server is
659 the first (or perhaps the only) server listed in the configuration, your
660 @env{DISPLAY} is @samp{glasperle:0.0}.
661
662 You can specify the display name explicitly when you run Emacs, either
663 by changing the @env{DISPLAY} variable, or with the option @samp{-d
664 @var{display}} or @samp{--display=@var{display}}. Here is an example:
665
666 @smallexample
667 emacs --display=glasperle:0 &
668 @end smallexample
669
670 You can inhibit the direct use of the window system and GUI with the
671 @samp{-nw} option. It tells Emacs to display using ordinary ASCII on
672 its controlling terminal. This is also an initial option.
673
674 Sometimes, security arrangements prevent a program on a remote system
675 from displaying on your local system. In this case, trying to run Emacs
676 produces messages like this:
677
678 @smallexample
679 Xlib: connection to "glasperle:0.0" refused by server
680 @end smallexample
681
682 @noindent
683 You might be able to overcome this problem by using the @command{xhost}
684 command on the local system to give permission for access from your
685 remote machine.
686
687 @node Font X
688 @appendixsec Font Specification Options
689 @cindex font name (X Window System)
690
691 By default, Emacs displays text in the font named @samp{9x15}, which
692 makes each character nine pixels wide and fifteen pixels high. You can
693 specify a different font on your command line through the option
694 @samp{-fn @var{name}} (or @samp{--font}, which is an alias for
695 @samp{-fn}).
696
697 @table @samp
698 @item -fn @var{name}
699 @opindex -fn
700 @itemx --font=@var{name}
701 @opindex --font
702 @cindex specify default font from the command line
703 Use font @var{name} as the default font.
704 @end table
705
706 Under X, each font has a long name which consists of eleven words or
707 numbers, separated by dashes. Some fonts also have shorter
708 nicknames---@samp{9x15} is such a nickname. You can use either kind of
709 name. You can use wildcard patterns for the font name; then Emacs lets
710 X choose one of the fonts that match the pattern. Here is an example,
711 which happens to specify the font whose nickname is @samp{6x13}:
712
713 @smallexample
714 emacs -fn \
715 "-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1" &
716 @end smallexample
717
718 @noindent
719 You can also specify the font in your @file{.Xdefaults} file:
720
721 @smallexample
722 emacs.font: -misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1
723 @end smallexample
724
725 A long font name has the following form:
726
727 @smallexample
728 -@var{maker}-@var{family}-@var{weight}-@var{slant}-@var{widthtype}-@var{style}@dots{}
729 @dots{}-@var{pixels}-@var{height}-@var{horiz}-@var{vert}-@var{spacing}-@var{width}-@var{charset}
730 @end smallexample
731
732 @table @var
733 @item maker
734 This is the name of the font manufacturer.
735 @item family
736 This is the name of the font family---for example, @samp{courier}.
737 @item weight
738 This is normally @samp{bold}, @samp{medium} or @samp{light}. Other
739 words may appear here in some font names.
740 @item slant
741 This is @samp{r} (roman), @samp{i} (italic), @samp{o} (oblique),
742 @samp{ri} (reverse italic), or @samp{ot} (other).
743 @item widthtype
744 This is normally @samp{condensed}, @samp{extended}, @samp{semicondensed}
745 or @samp{normal}. Other words may appear here in some font names.
746 @item style
747 This is an optional additional style name. Usually it is empty---most
748 long font names have two hyphens in a row at this point.
749 @item pixels
750 This is the font height, in pixels.
751 @item height
752 This is the font height on the screen, measured in tenths of a printer's
753 point---approximately 1/720 of an inch. In other words, it is the point
754 size of the font, times ten. For a given vertical resolution,
755 @var{height} and @var{pixels} are proportional; therefore, it is common
756 to specify just one of them and use @samp{*} for the other.
757 @item horiz
758 This is the horizontal resolution, in pixels per inch, of the screen for
759 which the font is intended.
760 @item vert
761 This is the vertical resolution, in pixels per inch, of the screen for
762 which the font is intended. Normally the resolution of the fonts on
763 your system is the right value for your screen; therefore, you normally
764 specify @samp{*} for this and @var{horiz}.
765 @item spacing
766 This is @samp{m} (monospace), @samp{p} (proportional) or @samp{c}
767 (character cell).
768 @item width
769 This is the average character width, in pixels, multiplied by ten.
770 @item charset
771 This is the character set that the font depicts.
772 Normally you should use @samp{iso8859-1}.
773 @end table
774
775 @cindex listing system fonts
776 You will probably want to use a fixed-width default font---that is,
777 a font in which all characters have the same width. Any font with
778 @samp{m} or @samp{c} in the @var{spacing} field of the long name is a
779 fixed-width font. Here's how to use the @command{xlsfonts} program to
780 list all the fixed-width fonts available on your system:
781
782 @example
783 xlsfonts -fn '*x*' | egrep "^[0-9]+x[0-9]+"
784 xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-m*'
785 xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-c*'
786 @end example
787
788 @noindent
789 To see what a particular font looks like, use the @command{xfd} command.
790 For example:
791
792 @example
793 xfd -fn 6x13
794 @end example
795
796 @noindent
797 displays the entire font @samp{6x13}.
798
799 While running Emacs, you can set the font of the current frame
800 (@pxref{Frame Parameters}) or for a specific kind of text
801 (@pxref{Faces}).
802
803 @node Colors
804 @appendixsec Window Color Options
805 @cindex color of window
806 @cindex text colors, from command line
807
808 @findex list-colors-display
809 @cindex available colors
810 On a color display, you can specify which color to use for various
811 parts of the Emacs display. To find out what colors are available on
812 your system, type @kbd{M-x list-colors-display}, or press
813 @kbd{C-Mouse-2} and select @samp{Display Colors} from the pop-up menu.
814 If you do not specify colors, on windowed displays the default for the
815 background is white and the default for all other colors is black. On a
816 monochrome display, the foreground is black, the background is white,
817 and the border is gray if the display supports that. On terminals, the
818 background is usually black and the foreground is white.
819
820 Here is a list of the command-line options for specifying colors:
821
822 @table @samp
823 @item -fg @var{color}
824 @opindex -fg
825 @itemx --foreground-color=@var{color}
826 @opindex --foreground-color
827 @cindex foreground color, command-line argument
828 Specify the foreground color. @var{color} should be a standard color
829 name, or a numeric specification of the color's red, green, and blue
830 components as in @samp{#4682B4} or @samp{RGB:46/82/B4}.
831 @item -bg @var{color}
832 @opindex -bg
833 @itemx --background-color=@var{color}
834 @opindex --background-color
835 @cindex background color, command-line argument
836 Specify the background color.
837 @item -bd @var{color}
838 @opindex -bd
839 @itemx --border-color=@var{color}
840 @opindex --border-color
841 @cindex border color, command-line argument
842 Specify the color of the border of the X window.
843 @item -cr @var{color}
844 @opindex -cr
845 @itemx --cursor-color=@var{color}
846 @opindex --cursor-color
847 @cindex cursor color, command-line argument
848 Specify the color of the Emacs cursor which indicates where point is.
849 @item -ms @var{color}
850 @opindex -ms
851 @itemx --mouse-color=@var{color}
852 @opindex --mouse-color
853 @cindex mouse pointer color, command-line argument
854 Specify the color for the mouse cursor when the mouse is in the Emacs window.
855 @item -r
856 @opindex -r
857 @itemx -rv
858 @opindex -rv
859 @itemx --reverse-video
860 @opindex --reverse-video
861 @cindex reverse video, command-line argument
862 Reverse video---swap the foreground and background colors.
863 @item --color=@var{mode}
864 @opindex --color
865 @cindex standard colors on a character terminal
866 For a character terminal only, specify the mode of color support. The
867 parameter @var{mode} can be one of the following:
868 @table @samp
869 @item never
870 @itemx no
871 Don't use colors even if the terminal's capabilities specify color
872 support.
873 @item default
874 @itemx auto
875 Same as when @option{--color} is not used at all: Emacs detects at
876 startup whether the terminal supports colors, and if it does, turns on
877 colored display.
878 @item always
879 @itemx yes
880 @itemx ansi8
881 Turn on the color support unconditionally, and use color commands
882 specified by the ANSI escape sequences for the 8 standard colors.
883 @item @var{num}
884 Use color mode for @var{num} colors. If @var{num} is -1, turn off
885 color support (equivalent to @samp{never}); if it is 0, use the
886 default color support for this terminal (equivalent to @samp{auto});
887 otherwise use an appropriate standard mode for @var{num} colors. If
888 there is no mode that supports @var{num} colors, Emacs acts as if
889 @var{num} were 0, i.e.@: it uses the terminal's default color support
890 mode.
891 @end table
892 If @var{mode} is omitted, it defaults to @var{ansi8}.
893 @end table
894
895 For example, to use a coral mouse cursor and a slate blue text cursor,
896 enter:
897
898 @example
899 emacs -ms coral -cr 'slate blue' &
900 @end example
901
902 You can reverse the foreground and background colors through the
903 @samp{-rv} option or with the X resource @samp{reverseVideo}.
904
905 The @samp{-fg}, @samp{-bg}, and @samp{-rv} options function on
906 text-only terminals as well as on window systems.
907
908 @node Window Size X
909 @appendixsec Options for Window Size and Position
910 @cindex geometry of Emacs window
911 @cindex position and size of Emacs frame
912 @cindex width and height of Emacs frame
913 @cindex specifying fullscreen for Emacs frame
914
915 Here is a list of the command-line options for specifying size and
916 position of the initial Emacs frame:
917
918 @table @samp
919 @item -g @var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
920 @opindex -g
921 Specify the size @var{width} and @var{height} (measured in character
922 columns and lines), and positions @var{xoffset} and @var{yoffset}
923 (measured in pixels). This applies to all frames.
924
925 @item --geometry=@var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
926 @opindex --geometry
927 This is another way of writing the same thing.
928
929 @item -fs
930 @opindex -fs
931 @itemx --fullscreen
932 @opindex --fullscreen
933 @cindex fullscreen, command-line argument
934 Specify that width and height shall be the size of the screen.
935
936 @item -fh
937 @opindex -fh
938 @itemx --fullheight
939 @opindex --fullheight
940 @cindex fullheight, command-line argument
941 Specify that the height shall be the height of the screen.
942
943 @item -fw
944 @opindex -fw
945 @itemx --fullwidth
946 @opindex --fullwidth
947 @cindex fullwidth, command-line argument
948 Specify that the width shall be the width of the screen.
949 @end table
950
951
952 @noindent
953 In the @samp{--geometry} option, @code{@r{@{}+-@r{@}}} means either a plus
954 sign or a minus sign. A plus
955 sign before @var{xoffset} means it is the distance from the left side of
956 the screen; a minus sign means it counts from the right side. A plus
957 sign before @var{yoffset} means it is the distance from the top of the
958 screen, and a minus sign there indicates the distance from the bottom.
959 The values @var{xoffset} and @var{yoffset} may themselves be positive or
960 negative, but that doesn't change their meaning, only their direction.
961
962 Emacs uses the same units as @command{xterm} does to interpret the geometry.
963 The @var{width} and @var{height} are measured in characters, so a large font
964 creates a larger frame than a small font. (If you specify a proportional
965 font, Emacs uses its maximum bounds width as the width unit.) The
966 @var{xoffset} and @var{yoffset} are measured in pixels.
967
968 You do not have to specify all of the fields in the geometry
969 specification. If you omit both @var{xoffset} and @var{yoffset}, the
970 window manager decides where to put the Emacs frame, possibly by
971 letting you place it with the mouse. For example, @samp{164x55}
972 specifies a window 164 columns wide, enough for two ordinary width
973 windows side by side, and 55 lines tall.
974
975 The default width for Emacs is 80 characters and the default height is
976 40 lines. You can omit either the width or the height or both. If
977 you start the geometry with an integer, Emacs interprets it as the
978 width. If you start with an @samp{x} followed by an integer, Emacs
979 interprets it as the height. Thus, @samp{81} specifies just the width;
980 @samp{x45} specifies just the height.
981
982 If you start with @samp{+} or @samp{-}, that introduces an offset,
983 which means both sizes are omitted. Thus, @samp{-3} specifies the
984 @var{xoffset} only. (If you give just one offset, it is always
985 @var{xoffset}.) @samp{+3-3} specifies both the @var{xoffset} and the
986 @var{yoffset}, placing the frame near the bottom left of the screen.
987
988 You can specify a default for any or all of the fields in
989 @file{.Xdefaults} file, and then override selected fields with a
990 @samp{--geometry} option.
991
992 Since the mode line and the echo area occupy the last 2 lines of the
993 frame, the height of the initial text window is 2 less than the height
994 specified in your geometry. In non-X-toolkit versions of Emacs, the
995 menu bar also takes one line of the specified number. But in the X
996 toolkit version, the menu bar is additional and does not count against
997 the specified height. The tool bar, if present, is also additional.
998
999 Enabling or disabling the menu bar or tool bar alters the amount of
1000 space available for ordinary text. Therefore, if Emacs starts up with
1001 a tool bar (which is the default), and handles the geometry
1002 specification assuming there is a tool bar, and then your
1003 @file{~/.emacs} file disables the tool bar, you will end up with a
1004 frame geometry different from what you asked for. To get the intended
1005 size with no tool bar, use an X resource to specify ``no tool bar''
1006 (@pxref{Table of Resources});then Emacs will already know there's no
1007 tool bar when it processes the specified geometry.
1008
1009 When using one of @samp{--fullscreen}, @samp{--fullwidth} or
1010 @samp{--fullheight} there may be some space around the frame
1011 anyway. That is because Emacs rounds the sizes so they are an
1012 even number of character heights and widths.
1013
1014 Some window managers have options that can make them ignore both
1015 program-specified and user-specified positions (sawfish is one).
1016 If these are set, Emacs fails to position the window correctly.
1017
1018 @node Borders X
1019 @appendixsec Internal and External Borders
1020 @cindex borders (X Window System)
1021
1022 An Emacs frame has an internal border and an external border. The
1023 internal border is an extra strip of the background color around the
1024 text portion of the frame. Emacs itself draws the internal border.
1025 The external border is added by the window manager outside the frame;
1026 depending on the window manager you use, it may contain various boxes
1027 you can click on to move or iconify the window.
1028
1029 @table @samp
1030 @item -ib @var{width}
1031 @opindex -ib
1032 @itemx --internal-border=@var{width}
1033 @opindex --internal-border
1034 @cindex border width, command-line argument
1035 Specify @var{width} as the width of the internal border, in pixels.
1036
1037 @item -bw @var{width}
1038 @opindex -bw
1039 @itemx --border-width=@var{width}
1040 @opindex --border-width
1041 Specify @var{width} as the width of the main border, in pixels.
1042 @end table
1043
1044 When you specify the size of the frame, that does not count the
1045 borders. The frame's position is measured from the outside edge of the
1046 external border.
1047
1048 Use the @samp{-ib @var{n}} option to specify an internal border
1049 @var{n} pixels wide. The default is 1. Use @samp{-bw @var{n}} to
1050 specify the width of the external border (though the window manager may
1051 not pay attention to what you specify). The default width of the
1052 external border is 2.
1053
1054 @node Title X
1055 @appendixsec Frame Titles
1056
1057 An Emacs frame may or may not have a specified title. The frame
1058 title, if specified, appears in window decorations and icons as the
1059 name of the frame. If an Emacs frame has no specified title, the
1060 default title has the form @samp{@var{invocation-name}@@@var{machine}}
1061 (if there is only one frame) or the selected window's buffer name (if
1062 there is more than one frame).
1063
1064 You can specify a title for the initial Emacs frame with a command
1065 line option:
1066
1067 @table @samp
1068 @item -title @var{title}
1069 @opindex --title
1070 @itemx --title=@var{title}
1071 @itemx -T @var{title}
1072 @opindex -T
1073 @cindex frame title, command-line argument
1074 Specify @var{title} as the title for the initial Emacs frame.
1075 @end table
1076
1077 The @samp{--name} option (@pxref{Resources}) also specifies the title
1078 for the initial Emacs frame.
1079
1080 @node Icons X
1081 @appendixsec Icons
1082 @cindex icons (X Window System)
1083
1084 Most window managers allow the user to ``iconify'' a frame, removing
1085 it from sight, and leaving a small, distinctive ``icon'' window in its
1086 place. Clicking on the icon window makes the frame itself appear again.
1087 If you have many clients running at once, you can avoid cluttering up
1088 the screen by iconifying most of the clients.
1089
1090 @table @samp
1091 @item -i
1092 @opindex -i
1093 @itemx --icon-type
1094 @opindex --icon-type
1095 @cindex Emacs icon, a gnu
1096 Use a picture of a gnu as the Emacs icon.
1097
1098 @item -iconic
1099 @opindex --iconic
1100 @itemx --iconic
1101 @cindex start iconified, command-line argument
1102 Start Emacs in iconified state.
1103 @end table
1104
1105 The @samp{-i} or @samp{--icon-type} option tells Emacs to use an icon
1106 window containing a picture of the GNU gnu. If omitted, Emacs lets the
1107 window manager choose what sort of icon to use---usually just a small
1108 rectangle containing the frame's title.
1109
1110 The @samp{-iconic} option tells Emacs to begin running as an icon,
1111 rather than showing a frame right away. In this situation, the icon
1112 is the only indication that Emacs has started; the text frame doesn't
1113 appear until you deiconify it.