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)
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
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{-}.
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.
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.
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.
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.
57 * Action Arguments:: Arguments to visit files, load libraries,
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.
65 @node Action Arguments
66 @appendixsec Action Arguments
68 Here is a table of the action arguments and options:
73 @itemx --visit=@var{file}
75 @itemx --file=@var{file}
76 @cindex visiting files, command-line argument
77 Visit @var{file} using @code{find-file}. @xref{Visiting}.
79 @item +@var{linenum} @var{file}
80 @opindex +@var{linenum}
81 Visit @var{file} using @code{find-file}, then go to line number
84 @item +@var{linenum}:@var{columnnum} @var{file}
85 Visit @var{file} using @code{find-file}, then go to line number
86 @var{linenum} and put point at column number @var{columnnum}.
91 @itemx --load=@var{file}
93 @cindex loading Lisp libraries, command-line argument
94 Load a Lisp library named @var{file} with the function @code{load}.
95 @xref{Lisp Libraries}. The library can be found either in the current
96 directory, or in the Emacs library search path as specified
97 with @env{EMACSLOADPATH} (@pxref{General Variables}).
99 @item -f @var{function}
101 @itemx --funcall=@var{function}
103 @cindex call Lisp functions, command-line argument
104 Call Lisp function @var{function} with no arguments.
106 @item --eval=@var{expression}
108 @itemx --execute=@var{expression}
110 @cindex evaluate expression, command-line argument
111 Evaluate Lisp expression @var{expression}.
113 @item --insert=@var{file}
115 @cindex insert file contents, command-line argument
116 Insert the contents of @var{file} into the current buffer. This is like
117 what @kbd{M-x insert-file} does. @xref{Misc File Ops}.
121 Exit from Emacs without asking for confirmation.
124 @vindex command-line-args
125 The init file can access the values of the action arguments as the
126 elements of a list in the variable @code{command-line-args}. The init
127 file can override the normal processing of the action arguments, or
128 define new ones, by reading and setting this variable.
130 @node Initial Options
131 @appendixsec Initial Options
133 The initial options specify parameters for the Emacs session. This
134 section describes the more general initial options; some other options
135 specifically related to the X Window System appear in the following
138 Some initial options affect the loading of init files. The normal
139 actions of Emacs are to first load @file{site-start.el} if it exists,
140 then your own init file @file{~/.emacs} if it exists, and finally
141 @file{default.el} if it exists; certain options prevent loading of some
142 of these files or substitute other files for them.
145 @item -t @var{device}
147 @itemx --terminal=@var{device}
149 @cindex device for Emacs terminal I/O
150 Use @var{device} as the device for terminal input and output.
152 @item -d @var{display}
154 @itemx --display=@var{display}
156 @cindex display for Emacs frame
157 Use the X Window System and use the display named @var{display} to open
158 the initial Emacs frame. @xref{Display X}, for more details.
162 @itemx --no-window-system
163 @opindex --no-window-system
164 @cindex disable window system
165 Don't communicate directly with the window system, disregarding the
166 @env{DISPLAY} environment variable even if it is set. This means that
167 Emacs uses the terminal from which it was launched for all its display
175 Run Emacs in @dfn{batch mode}, which means that the text being edited is
176 not displayed and the standard terminal interrupt characters such as
177 @kbd{C-z} and @kbd{C-c} continue to have their normal effect. Emacs in
178 batch mode outputs to @code{stderr} only what would normally be displayed
179 in the echo area under program control, and functions which would
180 normally read from the minibuffer take their input from @code{stdin}.
182 Batch mode is used for running programs written in Emacs Lisp from
183 shell scripts, makefiles, and so on. Normally the @samp{-l} option
184 or @samp{-f} option will be used as well, to invoke a Lisp program
185 to do the batch processing.
187 @samp{-batch} implies @samp{-q} (do not load an init file). It also
188 causes Emacs to exit after processing all the command options. In
189 addition, it disables auto-saving except in buffers for which it has
190 been explicitly requested.
194 @itemx --no-init-file
195 @opindex --no-init-file
196 @cindex bypassing init and site-start file
197 @cindex init file, not loading
198 @cindex @file{default.el} file, not loading
199 Do not load your Emacs init file @file{~/.emacs}, or @file{default.el}
200 either. When invoked like this, Emacs does not allow saving options
201 changed with the @kbd{M-x customize} command and its variants.
202 @xref{Easy Customization}.
205 @opindex --no-site-file
206 @cindex @file{site-start.el} file, not loading
207 Do not load @file{site-start.el}. The options @samp{-q}, @samp{-u}
208 and @samp{-batch} have no effect on the loading of this file---this is
209 the only option that blocks it.
213 @itemx --user=@var{user}
215 @cindex load init file of another user
216 Load @var{user}'s Emacs init file @file{~@var{user}/.emacs} instead of
220 @opindex --debug-init
221 @cindex errors in init file
222 Enable the Emacs Lisp debugger for errors in the init file.
226 @cindex unibyte operation, command-line argument
227 Do almost everything with single-byte buffers and strings.
228 All buffers and strings are unibyte unless you (or a Lisp program)
229 explicitly ask for a multibyte buffer or string. (Note that Emacs
230 always loads Lisp files in multibyte mode, even if @samp{--unibyte} is
231 specified; see @ref{Enabling Multibyte}.) Setting the environment
232 variable @env{EMACS_UNIBYTE} has the same effect.
236 Inhibit the effect of @env{EMACS_UNIBYTE}, so that Emacs
237 uses multibyte characters by default, as usual.
240 @node Command Example
241 @appendixsec Command Argument Example
243 Here is an example of using Emacs with arguments and options. It
244 assumes you have a Lisp program file called @file{hack-c.el} which, when
245 loaded, performs some useful operation on the current buffer, expected
249 emacs -batch foo.c -l hack-c -f save-buffer >& log
253 This says to visit @file{foo.c}, load @file{hack-c.el} (which makes
254 changes in the visited file), save @file{foo.c} (note that
255 @code{save-buffer} is the function that @kbd{C-x C-s} is bound to), and
256 then exit back to the shell (because of @samp{-batch}). @samp{-batch}
257 also guarantees there will be no problem redirecting output to
258 @file{log}, because Emacs will not assume that it has a display terminal
261 @node Resume Arguments
262 @appendixsec Resuming Emacs with Arguments
264 You can specify action arguments for Emacs when you resume it after
265 a suspension. To prepare for this, put the following code in your
266 @file{.emacs} file (@pxref{Hooks}):
268 @c `resume-suspend-hook' is correct. It is the name of a function.
270 (add-hook 'suspend-hook 'resume-suspend-hook)
271 (add-hook 'suspend-resume-hook 'resume-process-args)
274 As further preparation, you must execute the shell script
275 @file{emacs.csh} (if you use csh as your shell) or @file{emacs.bash}
276 (if you use bash as your shell). These scripts define an alias named
277 @code{edit}, which will resume Emacs giving it new command line
278 arguments such as files to visit. The scripts are found in the
279 @file{etc} subdirectory of the Emacs distribution.
281 Only action arguments work properly when you resume Emacs. Initial
282 arguments are not recognized---it's too late to execute them anyway.
284 Note that resuming Emacs (with or without arguments) must be done from
285 within the shell that is the parent of the Emacs job. This is why
286 @code{edit} is an alias rather than a program or a shell script. It is
287 not possible to implement a resumption command that could be run from
288 other subjobs of the shell; there is no way to define a command that could
289 be made the value of @env{EDITOR}, for example. Therefore, this feature
290 does not take the place of the Emacs Server feature (@pxref{Emacs
293 The aliases use the Emacs Server feature if you appear to have a
294 server Emacs running. However, they cannot determine this with complete
295 accuracy. They may think that a server is still running when in
296 actuality you have killed that Emacs, because the file
297 @file{/tmp/esrv@dots{}} still exists. If this happens, find that
301 @appendixsec Environment Variables
302 @cindex environment variables
304 The @dfn{environment} is a feature of the operating system; it
305 consists of a collection of variables with names and values. Each
306 variable is called an @dfn{environment variable}; environment variable
307 names are case-sensitive, and it is conventional to use upper case
308 letters only. The values are all text strings.
310 What makes the environment useful is that subprocesses inherit the
311 environment automatically from their parent process. This means you
312 can set up an environment variable in your login shell, and all the
313 programs you run (including Emacs) will automatically see it.
314 Subprocesses of Emacs (such as shells, compilers, and version-control
315 software) inherit the environment from Emacs, too.
319 Inside Emacs, the command @kbd{M-x getenv} gets the value of an
320 environment variable. @kbd{M-x setenv} sets a variable in the Emacs
321 environment. The way to set environment variables outside of Emacs
322 depends on the operating system, and especially the shell that you are
323 using. For example, here's how to set the environment variable
324 @env{ORGANIZATION} to @samp{not very much} using Bash:
327 export ORGANIZATION="not very much"
331 and here's how to do it in csh or tcsh:
334 setenv ORGANIZATION "not very much"
337 When Emacs is uses the X Window System, it inherits the use
338 of a large number of environment variables from the X libraries. See
339 the X documentation for more information.
342 * General Variables:: Environment variables that all versions of Emacs use.
343 * Misc Variables:: Certain system-specific variables.
346 @node General Variables
347 @appendixsubsec General Variables
349 Here is an alphabetical list of specific environment variables that
350 have special meanings in Emacs, giving the name of each variable and
351 its meaning. Most of these variables are also used by some other
352 programs. Emacs does not require any of these environment variables
353 to be set, but it uses their values if they are set.
357 Used by the @code{cd} command to search for the directory you specify,
358 when you specify a relative directory name.
360 @cindex unibyte operation, environment variable
361 Defining this environment variable with a nonempty value directs Emacs
362 to do almost everything with single-byte buffers and strings. It is
363 equivalent to using the @samp{--unibyte} command-line option on each
364 invocation. @xref{Initial Options}.
366 Directory for the architecture-independent files that come with Emacs.
367 This is used to initialize the Lisp variable @code{data-directory}.
369 Directory for the documentation string file,
370 @file{DOC-@var{emacsversion}}. This is used to initialize the Lisp
371 variable @code{doc-directory}.
373 A colon-separated list of directories@footnote{
374 Here and below, whenever we say ``colon-separated list of directories'',
375 it pertains to Unix and GNU/Linux systems. On MS-DOS and MS-Windows,
376 the directories are separated by semi-colons instead, since DOS/Windows
377 file names might include a colon after a drive letter.}
378 to search for Emacs Lisp files---used to initialize @code{load-path}.
380 A colon-separated list of directories to search for executable
381 files---used to initialize @code{exec-path}.
383 Used for shell-mode to override the @env{SHELL} environment variable.
385 The name of the file that shell commands are saved in between logins.
386 This variable defaults to @file{~/.bash_history} if you use Bash, to
387 @file{~/.sh_history} if you use ksh, and to @file{~/.history}
390 The location of the user's files in the directory tree; used for
391 expansion of file names starting with a tilde (@file{~}). On MS-DOS, it
392 defaults to the directory from which Emacs was started, with @samp{/bin}
393 removed from the end if it was present. On Windows, the default value
394 of @code{HOME} is @file{C:/}, the root directory of drive @file{C:}.
396 The name of the machine that Emacs is running on.
398 A colon-separated list of directories. Used by the @code{complete} package
401 A colon-separated list of directories in which to search for Info files.
410 The user's preferred locale. The locale has six categories, specified
411 by the environment variables @env{LC_COLLATE} for sorting,
412 @env{LC_CTYPE} for character encoding, @env{LC_MESSAGES} for system
413 messages, @env{LC_MONETARY} for monetary formats, @env{LC_NUMERIC} for
414 numbers, and @env{LC_TIME} for dates and times. If one of these
415 variables is not set, the category defaults to the value of the
416 @env{LANG} environment variable, or to the default @samp{C} locale if
417 @env{LANG} is not set. But if @env{LC_ALL} is specified, it overrides
418 the settings of all the other locale environment variables.
420 The value of the LC_CTYPE category is
421 matched against entries in @code{locale-language-names},
422 @code{locale-charset-language-names}, and
423 @code{locale-preferred-coding-systems}, to select a default language
424 environment and coding system. @xref{Language Environments}.
426 The user's login name. See also @env{USER}.
428 The name of the user's system mail inbox.
430 Name of file containing mail aliases. (The default is
433 Name of setup file for the mh system. (The default is @file{~/.mh_profile}.)
435 The real-world name of the user.
437 The name of the news server. Used by the mh and Gnus packages.
439 The name of the organization to which you belong. Used for setting the
440 `Organization:' header in your posts from the Gnus package.
442 A colon-separated list of directories in which executables reside. This
443 is used to initialize the Emacs Lisp variable @code{exec-path}.
445 If set, this should be the default directory when Emacs was started.
447 If set, this specifies an initial value for the variable
448 @code{mail-default-reply-to}. @xref{Mail Headers}.
450 The name of a directory in which news articles are saved by default.
451 Used by the Gnus package.
453 The name of an interpreter used to parse and execute programs run from
455 @cindex background mode, on @code{xterm}
457 The type of the terminal that Emacs is using. This variable must be
458 set unless Emacs is run in batch mode. On MS-DOS, it defaults to
459 @samp{internal}, which specifies a built-in terminal emulation that
460 handles the machine's own display. If the value of @env{TERM} indicates
461 that Emacs runs in non-windowed mode from @code{xterm} or a similar
462 terminal emulator, the background mode defaults to @samp{light}, and
463 Emacs will choose colors that are appropriate for a light background.
465 The name of the termcap library file describing how to program the
466 terminal specified by the @env{TERM} variable. This defaults to
469 Used by the Emerge package as a prefix for temporary files.
471 This specifies the current time zone and possibly also daylight
472 saving time information. On MS-DOS, if @code{TZ} is not set in the
473 environment when Emacs starts, Emacs defines a default value as
474 appropriate for the country code returned by DOS. On MS-Windows, Emacs
475 does not use @code{TZ} at all.
477 The user's login name. See also @env{LOGNAME}. On MS-DOS, this
478 defaults to @samp{root}.
479 @item VERSION_CONTROL
480 Used to initialize the @code{version-control} variable (@pxref{Backup
485 @appendixsubsec Miscellaneous Variables
487 These variables are used only on particular configurations:
491 On MS-DOS and MS-Windows, the name of the command interpreter to use
492 when invoking batch files and commands internal to the shell. On MS-DOS
493 this is also used to make a default value for the @env{SHELL} environment
497 On MS-DOS, this variable defaults to the value of the @env{USER}
502 On MS-DOS and MS-Windows, these specify the name of the directory for
503 storing temporary files in.
506 On MS-DOS, this specifies a file to use to log the operation of the
507 internal terminal emulator. This feature is useful for submitting bug
511 On MS-DOS, this specifies the screen colors. It is useful to set them
512 this way, since otherwise Emacs would display the default colors
513 momentarily when it starts up.
515 The value of this variable should be the two-character encoding of the
516 foreground (the first character) and the background (the second
517 character) colors of the default face. Each character should be the
518 hexadecimal code for the desired color on a standard PC text-mode
519 display. For example, to get blue text on a light gray background,
520 specify @samp{EMACSCOLORS=17}, since 1 is the code of the blue color and
521 7 is the code of the light gray color.
523 The PC display usually supports only eight background colors. However,
524 Emacs switches the DOS display to a mode where all 16 colors can be used
525 for the background, so all four bits of the background color are
529 Used when initializing the Sun windows system.