1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
| | @c This is part of the Emacs manual.
@c Copyright (C) 1985-1987, 1993-1995, 1997, 2001-2016 Free Software
@c Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Emacs Invocation
@appendix Command Line Arguments for Emacs Invocation
@cindex command line arguments
@cindex arguments (command line)
@cindex options (command line)
@cindex switches (command line)
@cindex startup (command line arguments)
@cindex invocation (command line arguments)
@c FIXME: Document '--smid'? --xfq
Emacs supports command line arguments to request various actions
when invoking Emacs. These are for compatibility with other editors
and for sophisticated activities. We don't recommend using them for
ordinary editing (@xref{Emacs Server}, for a way to access an existing
Emacs job from the command line).
Arguments starting with @samp{-} are @dfn{options}, and so is
@samp{+@var{linenum}}. All other arguments specify files to visit.
Emacs visits the specified files while it starts up. The last file
specified on the command line becomes the current buffer; the other
files are also visited in other buffers. As with most programs, the
special argument @samp{--} says that all subsequent arguments are file
names, not options, even if they start with @samp{-}.
Emacs command options can specify many things, such as the size and
position of the X window Emacs uses, its colors, and so on. A few
options support advanced usage, such as running Lisp functions on files
in batch mode. The sections of this chapter describe the available
options, arranged according to their purpose.
There are two ways of writing options: the short forms that start with
a single @samp{-}, and the long forms that start with @samp{--}. For
example, @samp{-d} is a short form and @samp{--display} is the
corresponding long form.
The long forms with @samp{--} are easier to remember, but longer to
type. However, you don't have to spell out the whole option name; any
unambiguous abbreviation is enough. When a long option takes an
argument, you can use either a space or an equal sign to separate the
option name and the argument. Thus, you can write either
@samp{--display sugar-bombs:0.0} or @samp{--display=sugar-bombs:0.0}.
We recommend an equal sign because it makes the relationship clearer,
and the tables below always show an equal sign.
@cindex initial options (command line)
@cindex action options (command line)
@vindex command-line-args
Most options specify how to initialize Emacs, or set parameters for
the Emacs session. We call them @dfn{initial options}. A few options
specify things to do, such as loading libraries or calling Lisp
functions. These are called @dfn{action options}. These and file
names together are called @dfn{action arguments}. The action
arguments are stored as a list of strings in the variable
@code{command-line-args}. (Actually, when Emacs starts up,
@code{command-line-args} contains all the arguments passed from the
command line; during initialization, the initial arguments are removed
from this list when they are processed, leaving only the action
arguments.)
@menu
* Action Arguments:: Arguments to visit files, load libraries,
and call functions.
* Initial Options:: Arguments that take effect while starting Emacs.
* Command Example:: Examples of using command line arguments.
* Environment:: Environment variables that Emacs uses.
* Display X:: Changing the default display and using remote login.
* Font X:: Choosing a font for text, under X.
* Colors X:: Choosing display colors.
* Window Size X:: Start-up window size, under X.
* Borders X:: Internal and external borders, under X.
* Title X:: Specifying the initial frame's title.
* Icons X:: Choosing what sort of icon to use, under X.
* Misc X:: Other display options.
@end menu
@node Action Arguments
@appendixsec Action Arguments
Here is a table of action arguments:
@table @samp
@item @var{file}
@opindex --file
@itemx --file=@var{file}
@opindex --find-file
@itemx --find-file=@var{file}
@opindex --visit
@itemx --visit=@var{file}
@cindex visiting files, command-line argument
@vindex inhibit-startup-buffer-menu
Visit @var{file} using @code{find-file}. @xref{Visiting}.
When Emacs starts up, it displays the startup buffer in one window,
and the buffer visiting @var{file} in another window
(@pxref{Windows}). If you supply more than one file argument, the
displayed file is the last one specified on the command line; the
other files are visited but their buffers are not shown.
If the startup buffer is disabled (@pxref{Entering Emacs}), then
@var{file} is visited in a single window if one file argument was
supplied; with two file arguments, Emacs displays the files in two
different windows; with more than two file argument, Emacs displays
the last file specified in one window, plus a Buffer Menu in a
different window (@pxref{Several Buffers}). To inhibit using the
Buffer Menu for this, change the variable
@code{inhibit-startup-buffer-menu} to @code{t}.
@item +@var{linenum} @var{file}
@opindex +@var{linenum}
Visit @var{file} using @code{find-file}, then go to line number
@var{linenum} in it.
@item +@var{linenum}:@var{columnnum} @var{file}
Visit @var{file} using @code{find-file}, then go to line number
@var{linenum} and put point at column number @var{columnnum}.
@item -l @var{file}
@opindex -l
@itemx --load=@var{file}
@opindex --load
@cindex loading Lisp libraries, command-line argument
Load a Lisp library named @var{file} with the function @code{load}.
If @var{file} is not an absolute file name, Emacs first looks for it
in the current directory, then in the directories listed in
@code{load-path} (@pxref{Lisp Libraries}).
@strong{Warning:} If previous command-line arguments have visited
files, the current directory is the directory of the last file
visited.
@item -L @var{dir}
@opindex -L
@itemx --directory=@var{dir}
@opindex --directory
Prepend directory @var{dir} to the variable @code{load-path}.
If you specify multiple @samp{-L} options, Emacs preserves the
relative order; i.e., using @samp{-L /foo -L /bar} results in
a @code{load-path} of the form @code{("/foo" "/bar" @dots{})}.
If @var{dir} begins with @samp{:}, Emacs removes the @samp{:} and
appends (rather than prepends) the remainder to @code{load-path}.
(On MS Windows, use @samp{;} instead of @samp{:}; i.e., use
the value of @code{path-separator}.)
@item -f @var{function}
@opindex -f
@itemx --funcall=@var{function}
@opindex --funcall
@cindex call Lisp functions, command-line argument
Call Lisp function @var{function}. If it is an interactive function
(a command), it reads the arguments interactively just as if you had
called the same function with a key sequence. Otherwise, it calls the
function with no arguments.
@item --eval=@var{expression}
@opindex --eval
@itemx --execute=@var{expression}
@opindex --execute
@cindex evaluate expression, command-line argument
Evaluate Lisp expression @var{expression}.
@item --insert=@var{file}
@opindex --insert
@cindex insert file contents, command-line argument
Insert the contents of @var{file} into the buffer that is current when
this command-line argument is processed. Usually, this is the
@file{*scratch*} buffer (@pxref{Lisp Interaction}), but if arguments
earlier on the command line visit files or switch buffers, that might
be a different buffer. The effect of this command-line argument is
like what @kbd{M-x insert-file} does (@pxref{Misc File Ops}).
@item --kill
@opindex --kill
Exit from Emacs without asking for confirmation.
@item --help
@opindex --help
Print a usage message listing all available options, then exit
successfully.
@item --version
@opindex --version
Print Emacs version, then exit successfully.
@end table
@node Initial Options
@appendixsec Initial Options
The initial options specify parameters for the Emacs session. This
section describes the more general initial options; some other options
specifically related to the X Window System appear in the following
sections.
Some initial options affect the loading of the initialization file.
Normally, Emacs first loads @file{site-start.el} if it exists, then
your own initialization file if it exists, and finally the default
initialization file @file{default.el} if it exists (@pxref{Init
File}). Certain options prevent loading of some of these files or
substitute other files for them.
@table @samp
@item -chdir @var{directory}
@opindex -chdir
@itemx --chdir=@var{directory}
@opindex --chdir
@cindex change Emacs directory
Change to @var{directory} before doing anything else. This is mainly used
by session management in X so that Emacs starts in the same directory as it
stopped. This makes desktop saving and restoring easier.
@item -t @var{device}
@opindex -t
@itemx --terminal=@var{device}
@opindex --terminal
@cindex device for Emacs terminal I/O
Use @var{device} as the device for terminal input and output. This
option implies @samp{--no-window-system}.
@item -d @var{display}
@opindex -d
@itemx --display=@var{display}
@opindex --display
@cindex display for Emacs frame
Use the X Window System and use the display named @var{display} to open
the initial Emacs frame. @xref{Display X}, for more details.
@item -nw
@opindex -nw
@itemx --no-window-system
@opindex --no-window-system
@cindex disable window system
Don't communicate directly with the window system, disregarding the
@env{DISPLAY} environment variable even if it is set. This means that
Emacs uses the terminal from which it was launched for all its display
and input.
@cindex batch mode
@item -batch
@opindex --batch
@itemx --batch
Run Emacs in @dfn{batch mode}. Batch mode is used for running
programs written in Emacs Lisp from shell scripts, makefiles, and so
on. To invoke a Lisp program, use the @samp{-batch} option in
conjunction with one or more of @samp{-l}, @samp{-f} or @samp{--eval}
(@pxref{Action Arguments}). @xref{Command Example}, for an example.
In batch mode, Emacs does not display the text being edited, and the
standard terminal interrupt characters such as @kbd{C-z} and @kbd{C-c}
have their usual effect. Emacs functions that normally print a
message in the echo area will print to either the standard output
stream (@code{stdout}) or the standard error stream (@code{stderr})
instead. (To be precise, functions like @code{prin1}, @code{princ}
and @code{print} print to @code{stdout}, while @code{message} and
@code{error} print to @code{stderr}.) Functions that normally read
keyboard input from the minibuffer take their input from the
terminal's standard input stream (@code{stdin}) instead.
@samp{--batch} implies @samp{-q} (do not load an initialization file),
but @file{site-start.el} is loaded nonetheless. It also causes Emacs
to exit after processing all the command options. In addition, it
disables auto-saving except in buffers for which auto-saving is
explicitly requested, and when saving files it omits the @code{fsync}
system call unless otherwise requested.
@item --script @var{file}
@opindex --script
@cindex script mode
Run Emacs in batch mode, like @samp{--batch}, and then read and
execute the Lisp code in @var{file}.
The normal use of this option is in executable script files that run
Emacs. They can start with this text on the first line
@example
#!/usr/bin/emacs --script
@end example
@noindent
which will invoke Emacs with @samp{--script} and supply the name of
the script file as @var{file}. Emacs Lisp then treats the @samp{#!}
on this first line as a comment delimiter.
@item --no-build-details
@opindex --no-build-details
@cindex build details
@cindex deterministic build
Omit details like system name and build time from the Emacs executable,
so that builds are more deterministic.
@item -q
@opindex -q
@itemx --no-init-file
@opindex --no-init-file
@cindex bypassing init and @file{default.el} file
@cindex init file, not loading
@cindex @file{default.el} file, not loading
Do not load any initialization file (@pxref{Init File}). When Emacs
is invoked with this option, the Customize facility does not allow
options to be saved (@pxref{Easy Customization}). This option does
not disable loading @file{site-start.el}.
@item --no-site-file
@opindex --no-site-file
@cindex @file{site-start.el} file, not loading
Do not load @file{site-start.el} (@pxref{Init File}). The @samp{-Q}
option does this too, but other options like @samp{-q} do not.
@item --no-site-lisp
@opindex --no-site-lisp
@cindex @file{site-start.el} file, not loading
Do not include the @file{site-lisp} directories in @code{load-path}
(@pxref{Init File}). The @samp{-Q} option does this too.
@item --no-splash
@opindex --no-splash
@vindex inhibit-startup-screen
@cindex splash screen
@cindex startup message
Do not display a startup screen. You can also achieve this effect by
setting the variable @code{inhibit-startup-screen} to non-@code{nil}
in your initialization file (@pxref{Entering Emacs}).
@item -Q
@opindex -Q
@itemx --quick
@opindex --quick
Start emacs with minimum customizations. This is similar to using @samp{-q},
@samp{--no-site-file}, @samp{--no-site-lisp}, and @samp{--no-splash}
together. This also stops Emacs from processing X resources by
setting @code{inhibit-x-resources} to @code{t} (@pxref{Resources}).
@item -daemon
@opindex -daemon
@itemx --daemon[=@var{name}]
@opindex --daemon
@itemx --old-daemon[=@var{name}]
@itemx --new-daemon[=@var{name}]
Start Emacs as a daemon---after Emacs starts up, it starts the Emacs
server without opening any frames.
(Optionally, you can specify an explicit @var{name} for the server.)
You can then use the @command{emacsclient} command to connect to Emacs
for editing. @xref{Emacs Server}, for information about using Emacs
as a daemon. An ``old-style'' daemon disconnects from the terminal
and runs in the background (@samp{--daemon} is an alias for
@samp{--old-daemon}).
@item --no-desktop
@opindex --no-desktop
Do not reload any saved desktop. @xref{Saving Emacs Sessions}.
@item -u @var{user}
@opindex -u
@itemx --user=@var{user}
@opindex --user
@cindex load init file of another user
Load @var{user}'s initialization file instead of your
own@footnote{This option has no effect on MS-Windows.}.
@item --debug-init
@opindex --debug-init
@cindex errors in init file
Enable the Emacs Lisp debugger for errors in the init file.
@xref{Error Debugging,, Entering the Debugger on an Error, elisp, The
GNU Emacs Lisp Reference Manual}.
@end table
@node Command Example
@appendixsec Command Argument Example
Here is an example of using Emacs with arguments and options. It
assumes you have a Lisp program file called @file{hack-c.el} which, when
loaded, performs some useful operation on the current buffer, expected
to be a C program.
@example
emacs --batch foo.c -l hack-c -f save-buffer >& log
@end example
@noindent
This says to visit @file{foo.c}, load @file{hack-c.el} (which makes
changes in the visited file), save @file{foo.c} (note that
@code{save-buffer} is the function that @kbd{C-x C-s} is bound to), and
then exit back to the shell (because of @samp{--batch}). @samp{--batch}
also guarantees there will be no problem redirecting output to
@file{log}, because Emacs will not assume that it has a display terminal
to work with.
@node Environment
@appendixsec Environment Variables
@cindex environment variables
The @dfn{environment} is a feature of the operating system; it
consists of a collection of variables with names and values. Each
variable is called an @dfn{environment variable}; environment variable
names are case-sensitive, and it is conventional to use upper case
letters only. The values are all text strings.
What makes the environment useful is that subprocesses inherit the
environment automatically from their parent process. This means you
can set up an environment variable in your login shell, and all the
programs you run (including Emacs) will automatically see it.
Subprocesses of Emacs (such as shells, compilers, and version control
programs) inherit the environment from Emacs, too.
@findex setenv
@findex getenv
@vindex initial-environment
Inside Emacs, the command @kbd{M-x getenv} reads the name of an
environment variable, and prints its value in the echo area. @kbd{M-x
setenv} sets a variable in the Emacs environment, and @kbd{C-u M-x
setenv} removes a variable. (Environment variable substitutions with
@samp{$} work in the value just as in file names; see @ref{File Names
with $}.) The variable @code{initial-environment} stores the initial
environment inherited by Emacs.
The way to set environment variables outside of Emacs depends on the
operating system, and especially the shell that you are using. For
example, here's how to set the environment variable @env{ORGANIZATION}
to @samp{not very much} using Bash:
@example
export ORGANIZATION="not very much"
@end example
@noindent
and here's how to do it in csh or tcsh:
@example
setenv ORGANIZATION "not very much"
@end example
When Emacs is using the X Window System, various environment
variables that control X work for Emacs as well. See the X
documentation for more information.
@menu
* General Variables:: Environment variables that all versions of Emacs use.
* Misc Variables:: Certain system-specific variables.
* MS-Windows Registry:: An alternative to the environment on MS-Windows.
@end menu
@node General Variables
@appendixsubsec General Variables
Here is an alphabetical list of environment variables that have
special meanings in Emacs. Most of these variables are also used by
some other programs. Emacs does not require any of these environment
variables to be set, but it uses their values if they are set.
@c This used to be @vtable, but that enters the variables alone into
@c the Variable Index, which in some cases, like HOME, might be
@c confused with keys by that name, and other cases, like NAME,
@c might be confused with general-purpose phrases.
@table @env
@item CDPATH
@vindex CDPATH, environment variable
Used by the @code{cd} command to search for the directory you specify,
when you specify a relative directory name.
@item DBUS_SESSION_BUS_ADDRESS
@vindex DBUS_SESSION_BUS_ADDRESS, environment variable
Used by D-Bus when Emacs is compiled with it. Usually, there is no
need to change it. Setting it to a dummy address, like
@samp{unix:path=/dev/null}, suppresses connections to the D-Bus session
bus as well as autolaunching the D-Bus session bus if not running yet.
@item EMACSDATA
@vindex EMACSDATA, environment variable
Directory for the architecture-independent files that come with Emacs.
This is used to initialize the variable @code{data-directory}.
@item EMACSDOC
#vindex EMACSDOC, environment variable
Directory for the documentation string file, which is used to
initialize the Lisp variable @code{doc-directory}.
@item EMACSLOADPATH
#vindex EMACSLOADPATH, environment variable
A colon-separated list of directories@footnote{Here and below,
whenever we say ``colon-separated list of directories'', it pertains
to Unix and GNU/Linux systems. On MS-DOS and MS-Windows, the
directories are separated by semi-colons instead, since DOS/Windows
file names might include a colon after a drive letter.} to search for
Emacs Lisp files. If set, it modifies the usual initial value of the
@code{load-path} variable (@pxref{Lisp Libraries}). An empty element
stands for the default value of @code{load-path}; e.g., using
@samp{EMACSLOADPATH="/tmp:"} adds @file{/tmp} to the front of
the default @code{load-path}. To specify an empty element in the
middle of the list, use 2 colons in a row, as in
@samp{EMACSLOADPATH="/tmp::/foo"}.
@item EMACSPATH
@vindex EMACSPATH, environment variable
A colon-separated list of directories to search for executable files.
If set, Emacs uses this in addition to @env{PATH} (see below) when
initializing the variable @code{exec-path} (@pxref{Shell}).
@item EMAIL
@vindex EMAIL, environment variable
@vindex user-mail-address@r{, initialization}
Your email address; used to initialize the Lisp variable
@code{user-mail-address}, which the Emacs mail interface puts into the
@samp{From} header of outgoing messages (@pxref{Mail Headers}).
@item ESHELL
@vindex ESHELL, environment variable
Used for shell-mode to override the @env{SHELL} environment variable
(@pxref{Interactive Shell}).
@item HISTFILE
@vindex HISTFILE, environment variable
The name of the file that shell commands are saved in between logins.
This variable defaults to @file{~/.bash_history} if you use Bash, to
@file{~/.sh_history} if you use ksh, and to @file{~/.history}
otherwise.
@item HOME
@vindex HOME, environment variable
The location of your files in the directory tree; used for
expansion of file names starting with a tilde (@file{~}). On MS-DOS,
it defaults to the directory from which Emacs was started, with
@samp{/bin} removed from the end if it was present. On Windows, the
default value of @env{HOME} is the @file{Application Data}
subdirectory of the user profile directory (normally, this is
@file{C:/Documents and Settings/@var{username}/Application Data},
where @var{username} is your user name), though for backwards
compatibility @file{C:/} will be used instead if a @file{.emacs} file
is found there.
@item HOSTNAME
@vindex HOSTNAME, environment variable
The name of the machine that Emacs is running on.
@c complete.el is obsolete since 24.1.
@ignore
@item INCPATH
A colon-separated list of directories. Used by the @code{complete} package
to search for files.
@end ignore
@item INFOPATH
@vindex INFOPATH, environment variable
A colon-separated list of directories in which to search for Info files.
@item LC_ALL
@vindex LC_ALL, environment variable
@itemx LC_COLLATE
@vindex LC_COLLATE, environment variable
@itemx LC_CTYPE
@vindex LC_CTYPE, environment variable
@itemx LC_MESSAGES
@vindex LC_MESSAGES, environment variable
@itemx LC_MONETARY
@vindex LC_MONETARY, environment variable
@itemx LC_NUMERIC
@vindex LC_NUMERIC, environment variable
@itemx LC_TIME
@vindex LC_TIME, environment variable
@itemx LANG
@vindex LANG, environment variable
The user's preferred locale. The locale has six categories, specified
by the environment variables @env{LC_COLLATE} for sorting,
@env{LC_CTYPE} for character encoding, @env{LC_MESSAGES} for system
messages, @env{LC_MONETARY} for monetary formats, @env{LC_NUMERIC} for
numbers, and @env{LC_TIME} for dates and times. If one of these
variables is not set, the category defaults to the value of the
@env{LANG} environment variable, or to the default @samp{C} locale if
@env{LANG} is not set. But if @env{LC_ALL} is specified, it overrides
the settings of all the other locale environment variables.
On MS-Windows and OS X, if @env{LANG} is not already set in the
environment, Emacs sets it based on the system-wide default. You can
set this in the ``Regional Settings'' Control Panel on some versions
of MS-Windows, and in the ``Language and Region'' System Preference on
OS X.
The value of the @env{LC_CTYPE} category is
matched against entries in @code{locale-language-names},
@code{locale-charset-language-names}, and
@code{locale-preferred-coding-systems}, to select a default language
environment and coding system. @xref{Language Environments}.
@item LOGNAME
@vindex LOGNAME, environment variable
The user's login name. See also @env{USER}.
@item MAIL
@vindex MAIL, environment variable
The name of your system mail inbox.
@ifnottex
@item MH
@vindex MH, environment variable
Name of setup file for the mh system. @xref{Top,,MH-E,mh-e, The Emacs
Interface to MH}.
@end ifnottex
@item NAME
@vindex NAME, environment variable
Your real-world name. This is used to initialize the variable
@code{user-full-name} (@pxref{Mail Headers}).
@item NNTPSERVER
@vindex NNTPSERVER, environment variable
The name of the news server. Used by the mh and Gnus packages.
@item ORGANIZATION
@vindex ORGANIZATION, environment variable
The name of the organization to which you belong. Used for setting the
@samp{Organization:} header in your posts from the Gnus package.
@item PATH
@vindex PATH, environment variable
A colon-separated list of directories containing executable files.
This is used to initialize the variable @code{exec-path}
(@pxref{Shell}).
@item PWD
@vindex PWD, environment variable
If set, this should be the default directory when Emacs was started.
@item REPLYTO
@vindex REPLYTO, environment variable
If set, this specifies an initial value for the variable
@code{mail-default-reply-to} (@pxref{Mail Headers}).
@item SAVEDIR
@vindex SAVEDIR, environment variable
The name of a directory in which news articles are saved by default.
Used by the Gnus package.
@item SHELL
@vindex SHELL, environment variable
The name of an interpreter used to parse and execute programs run from
inside Emacs.
@item SMTPSERVER
@vindex SMTPSERVER, environment variable
The name of the outgoing mail server. This is used to initialize the
variable @code{smtpmail-smtp-server} (@pxref{Mail Sending}).
@cindex background mode, on @command{xterm}
@item TERM
@vindex TERM, environment variable
The type of the terminal that Emacs is using. This variable must be
set unless Emacs is run in batch mode. On MS-DOS, it defaults to
@samp{internal}, which specifies a built-in terminal emulation that
handles the machine's own display.
@item TERMCAP
@vindex TERMCAP, environment variable
The name of the termcap library file describing how to program the
terminal specified by @env{TERM}. This defaults to
@file{/etc/termcap}.
@item TMPDIR
@vindex TMPDIR, environment variable
@itemx TMP
@vindex TMP, environment variable
@itemx TEMP
@vindex TEMP, environment variable
These environment variables are used to initialize the variable
@code{temporary-file-directory}, which specifies a directory in which
to put temporary files (@pxref{Backup}). Emacs tries to use
@env{TMPDIR} first. If that is unset, Emacs normally falls back on
@file{/tmp}, but on MS-Windows and MS-DOS it instead falls back on
@env{TMP}, then @env{TEMP}, and finally @file{c:/temp}.
@item TZ
@vindex TZ, environment variable
This specifies the default time zone and possibly also daylight
saving time information. @xref{Time Zone Rules,,, elisp, The GNU
Emacs Lisp Reference Manual}. On MS-DOS, if @env{TZ} is not set in the
environment when Emacs starts, Emacs defines a default value as
appropriate for the country code returned by DOS@. On MS-Windows, Emacs
does not use @env{TZ} at all.
@item USER
@vindex USER, environment variable
The user's login name. See also @env{LOGNAME}. On MS-DOS, this
defaults to @samp{root}.
@item VERSION_CONTROL
@vindex VERSION_CONTROL, environment variable
Used to initialize the @code{version-control} variable (@pxref{Backup
Names}).
@end table
@node Misc Variables
@appendixsubsec Miscellaneous Variables
These variables are used only on particular configurations:
@vtable @env
@item COMSPEC
On MS-DOS and MS-Windows, the name of the command interpreter to use
when invoking batch files and commands internal to the shell. On MS-DOS
this is also used to make a default value for the @env{SHELL} environment
variable.
@item NAME
On MS-DOS, this variable defaults to the value of the @env{USER}
variable.
@item EMACSTEST
On MS-DOS, this specifies a file to use to log the operation of the
internal terminal emulator. This feature is useful for submitting bug
reports.
@item EMACSCOLORS
On MS-DOS, this specifies the screen colors. It is useful to set them
this way, since otherwise Emacs would display the default colors
momentarily when it starts up.
The value of this variable should be the two-character encoding of the
foreground (the first character) and the background (the second
character) colors of the default face. Each character should be the
hexadecimal code for the desired color on a standard PC text-mode
display. For example, to get blue text on a light gray background,
specify @samp{EMACSCOLORS=17}, since 1 is the code of the blue color and
7 is the code of the light gray color.
The PC display usually supports only eight background colors. However,
Emacs switches the DOS display to a mode where all 16 colors can be used
for the background, so all four bits of the background color are
actually used.
@item PRELOAD_WINSOCK
On MS-Windows, if you set this variable, Emacs will load and initialize
the network library at startup, instead of waiting until the first
time it is required.
@item emacs_dir
On MS-Windows, @env{emacs_dir} is a special environment variable, which
indicates the full path of the directory in which Emacs is installed.
If Emacs is installed in the standard directory structure, it
calculates this value automatically. It is not much use setting this
variable yourself unless your installation is non-standard, since
unlike other environment variables, it will be overridden by Emacs at
startup. When setting other environment variables, such as
@env{EMACSLOADPATH}, you may find it useful to use @env{emacs_dir}
rather than hard-coding an absolute path. This allows multiple
versions of Emacs to share the same environment variable settings, and
it allows you to move the Emacs installation directory, without
changing any environment or registry settings.
@end vtable
@node MS-Windows Registry
@appendixsubsec The MS-Windows System Registry
@pindex addpm, MS-Windows installation program
@cindex registry, setting environment variables (MS-Windows)
On MS-Windows, the installation program @command{addpm.exe} adds
values for @env{emacs_dir}, @env{EMACSLOADPATH}, @env{EMACSDATA},
@env{EMACSPATH}, @env{EMACSDOC}, @env{SHELL} and @env{TERM} to the
@file{HKEY_LOCAL_MACHINE} section of the system registry, under
@file{/Software/GNU/Emacs}. It does this because there is no standard
place to set environment variables across different versions of
Windows. Running @command{addpm.exe} is no longer strictly necessary
in recent versions of Emacs, but if you are upgrading from an older
version, running @command{addpm.exe} ensures that you do not have
older registry entries from a previous installation, which may not be
compatible with the latest version of Emacs.
When Emacs starts, as well as checking the environment, it also checks
the System Registry for those variables and for @env{HOME}, @env{LANG}
and @env{PRELOAD_WINSOCK}.
To determine the value of those variables, Emacs goes through the
following procedure. First, the environment is checked. If the
variable is not found there, Emacs looks for registry keys by that
name under @file{/Software/GNU/Emacs}; first in the
@file{HKEY_CURRENT_USER} section of the registry, and if not found
there, in the @file{HKEY_LOCAL_MACHINE} section. Finally, if Emacs
still cannot determine the values, compiled-in defaults are used.
In addition to the environment variables above, you can also add many
of the settings which on X belong in the @file{.Xdefaults} file
(@pxref{X Resources}) to the @file{/Software/GNU/Emacs} registry key.
@node Display X
@appendixsec Specifying the Display Name
@cindex display name (X Window System)
@cindex @env{DISPLAY} environment variable
The environment variable @env{DISPLAY} tells all X clients,
including Emacs, where to display their windows. Its value is set by
default in ordinary circumstances, when you start an X server and run
jobs locally. You can specify the display yourself; one reason to do
this is if you want to log into another system and run Emacs there,
and have the window displayed at your local terminal.
@env{DISPLAY} has the syntax
@samp{@var{host}:@var{display}.@var{screen}}, where @var{host} is the
host name of the X Window System server machine, @var{display} is an
arbitrarily-assigned number that distinguishes your server (X
terminal) from other servers on the same machine, and @var{screen} is
a field that allows an X server to control multiple terminal screens.
The period and the @var{screen} field are optional. If included,
@var{screen} is usually zero.
For example, if your host is named @samp{glasperle} and your server is
the first (or perhaps the only) server listed in the configuration, your
@env{DISPLAY} is @samp{glasperle:0.0}.
You can specify the display name explicitly when you run Emacs, either
by changing the @env{DISPLAY} variable, or with the option @samp{-d
@var{display}} or @samp{--display=@var{display}}. Here is an example:
@smallexample
emacs --display=glasperle:0 &
@end smallexample
You can inhibit the use of the X window system with the @samp{-nw}
option. Then Emacs uses its controlling text terminal for display.
@xref{Initial Options}.
Sometimes, security arrangements prevent a program on a remote system
from displaying on your local system. In this case, trying to run Emacs
produces messages like this:
@smallexample
Xlib: connection to "glasperle:0.0" refused by server
@end smallexample
@noindent
You might be able to overcome this problem by using the @command{xhost}
command on the local system to give permission for access from your
remote machine.
@node Font X
@appendixsec Font Specification Options
@cindex font name (X Window System)
You can use the command line option @samp{-fn @var{font}} (or
@samp{--font}, which is an alias for @samp{-fn}) to specify a default
font:
@table @samp
@item -fn @var{font}
@opindex -fn
@itemx --font=@var{font}
@opindex --font
@cindex specify default font from the command line
Use @var{font} as the default font.
@end table
When passing a font name to Emacs on the command line, you may need to
quote it, by enclosing it in quotation marks, if it contains
characters that the shell treats specially (e.g., spaces). For
example:
@smallexample
emacs -fn "DejaVu Sans Mono-12"
@end smallexample
@xref{Fonts}, for details about font names and other ways to specify
the default font.
@node Colors X
@appendixsec Window Color Options
@cindex color of window, from command line
@cindex text colors, from command line
You can use the following command-line options to specify the colors
to use for various parts of the Emacs display. Colors may be
specified using either color names or RGB triplets (@pxref{Colors}).
@table @samp
@item -fg @var{color}
@opindex -fg
@itemx --foreground-color=@var{color}
@opindex --foreground-color
@cindex foreground color, command-line argument
Specify the foreground color, overriding the color specified by the
@code{default} face (@pxref{Faces}).
@item -bg @var{color}
@opindex -bg
@itemx --background-color=@var{color}
@opindex --background-color
@cindex background color, command-line argument
Specify the background color, overriding the color specified by the
@code{default} face.
@item -bd @var{color}
@opindex -bd
@itemx --border-color=@var{color}
@opindex --border-color
@cindex border color, command-line argument
Specify the color of the border of the X window. This has no effect
if Emacs is compiled with GTK+ support.
@item -cr @var{color}
@opindex -cr
@itemx --cursor-color=@var{color}
@opindex --cursor-color
@cindex cursor color, command-line argument
Specify the color of the Emacs cursor which indicates where point is.
@item -ms @var{color}
@opindex -ms
@itemx --mouse-color=@var{color}
@opindex --mouse-color
@cindex mouse pointer color, command-line argument
Specify the color for the mouse cursor when the mouse is in the Emacs window.
@item -r
@opindex -r
@itemx -rv
@opindex -rv
@itemx --reverse-video
@opindex --reverse-video
@cindex reverse video, command-line argument
Reverse video---swap the foreground and background colors.
@item --color=@var{mode}
@opindex --color
@cindex standard colors on a character terminal
@cindex override character terminal color support
Set the @dfn{color support mode} when Emacs is run on a text terminal.
This option overrides the number of supported colors that the
character terminal advertises in its @code{termcap} or @code{terminfo}
database. The parameter @var{mode} can be one of the following:
@table @samp
@item never
@itemx no
Don't use colors even if the terminal's capabilities specify color
support.
@item default
@itemx auto
Same as when @option{--color} is not used at all: Emacs detects at
startup whether the terminal supports colors, and if it does, turns on
colored display.
@item always
@itemx yes
@itemx ansi8
Turn on the color support unconditionally, and use color commands
specified by the ANSI escape sequences for the 8 standard colors.
@item @var{num}
Use color mode for @var{num} colors. If @var{num} is -1, turn off
color support (equivalent to @samp{never}); if it is 0, use the
default color support for this terminal (equivalent to @samp{auto});
otherwise use an appropriate standard mode for @var{num} colors.
Depending on your terminal's capabilities, Emacs might be able to turn
on a color mode for 8, 16, 88, or 256 as the value of @var{num}. If
there is no mode that supports @var{num} colors, Emacs acts as if
@var{num} were 0, i.e., it uses the terminal's default color support
mode.
@end table
If @var{mode} is omitted, it defaults to @var{ansi8}.
@end table
For example, to use a coral mouse cursor and a slate blue text cursor,
enter:
@example
emacs -ms coral -cr 'slate blue' &
@end example
You can reverse the foreground and background colors through the
@samp{-rv} option or with the X resource @samp{reverseVideo}.
The @samp{-fg}, @samp{-bg}, and @samp{-rv} options function on text
terminals as well as on graphical displays.
@node Window Size X
@appendixsec Options for Window Size and Position
@cindex geometry of Emacs window
@cindex position and size of Emacs frame
@cindex width and height of Emacs frame
@cindex specifying fullscreen for Emacs frame
Here is a list of the command-line options for specifying size and
position of the initial Emacs frame:
@table @samp
@item -g @var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
@opindex -g
@itemx --geometry=@var{width}x@var{height}@r{[@{}+-@r{@}}@var{xoffset}@r{@{}+-@r{@}}@var{yoffset}@r{]]}
@opindex --geometry
@cindex geometry, command-line argument
Specify the size @var{width} and @var{height} (measured in character
columns and lines), and positions @var{xoffset} and @var{yoffset}
(measured in pixels). The @var{width} and @var{height} parameters
apply to all frames, whereas @var{xoffset} and @var{yoffset} only to
the initial frame.
@item -fs
@opindex -fs
@itemx --fullscreen
@opindex --fullscreen
@cindex fullscreen, command-line argument
Specify that width and height should be that of the screen. Normally
no window manager decorations are shown. (After starting Emacs,
you can toggle this state using @key{F11}, @code{toggle-frame-fullscreen}.)
@item -mm
@opindex -mm
@itemx --maximized
@opindex --maximized
@cindex maximized, command-line argument
Specify that the Emacs frame should be maximized. This normally
means that the frame has window manager decorations.
(After starting Emacs, you can toggle this state using @kbd{M-F10},
@code{toggle-frame-maximized}.)
@item -fh
@opindex -fh
@itemx --fullheight
@opindex --fullheight
@cindex fullheight, command-line argument
Specify that the height should be the height of the screen.
@item -fw
@opindex -fw
@itemx --fullwidth
@opindex --fullwidth
@cindex fullwidth, command-line argument
Specify that the width should be the width of the screen.
@end table
@noindent
In the @samp{--geometry} option, @code{@r{@{}+-@r{@}}} means either a plus
sign or a minus sign. A plus
sign before @var{xoffset} means it is the distance from the left side of
the screen; a minus sign means it counts from the right side. A plus
sign before @var{yoffset} means it is the distance from the top of the
screen, and a minus sign there indicates the distance from the bottom.
The values @var{xoffset} and @var{yoffset} may themselves be positive or
negative, but that doesn't change their meaning, only their direction.
Emacs uses the same units as @command{xterm} does to interpret the geometry.
The @var{width} and @var{height} are measured in characters, so a large font
creates a larger frame than a small font. (If you specify a proportional
font, Emacs uses its maximum bounds width as the width unit.) The
@var{xoffset} and @var{yoffset} are measured in pixels.
You do not have to specify all of the fields in the geometry
specification. If you omit both @var{xoffset} and @var{yoffset}, the
window manager decides where to put the Emacs frame, possibly by
letting you place it with the mouse. For example, @samp{164x55}
specifies a window 164 columns wide, enough for two ordinary width
windows side by side, and 55 lines tall.
The default frame width is 80 characters and the default height is
40 lines. You can omit either the width or the height or both. If
you start the geometry with an integer, Emacs interprets it as the
width. If you start with an @samp{x} followed by an integer, Emacs
interprets it as the height. Thus, @samp{81} specifies just the
width; @samp{x45} specifies just the height.
If you start with @samp{+} or @samp{-}, that introduces an offset,
which means both sizes are omitted. Thus, @samp{-3} specifies the
@var{xoffset} only. (If you give just one offset, it is always
@var{xoffset}.) @samp{+3-3} specifies both the @var{xoffset} and the
@var{yoffset}, placing the frame near the bottom left of the screen.
You can specify a default for any or all of the fields in your X
resource file (@pxref{Resources}), and then override selected fields
with a @samp{--geometry} option.
Since the mode line and the echo area occupy the last 2 lines of the
frame, the height of the initial text window is 2 less than the height
specified in your geometry. In non-X-toolkit versions of Emacs, the
menu bar also takes one line of the specified number. But in the X
toolkit version, the menu bar is additional and does not count against
the specified height. The tool bar, if present, is also additional.
Enabling or disabling the menu bar or tool bar alters the amount of
space available for ordinary text. Therefore, if Emacs starts up with
a tool bar (which is the default), and handles the geometry
specification assuming there is a tool bar, and then your
initialization file disables the tool bar, you will end up with a
frame geometry different from what you asked for. To get the intended
size with no tool bar, use an X resource to specify ``no tool bar''
(@pxref{Table of Resources}); then Emacs will already know there's no
tool bar when it processes the specified geometry.
When using one of @samp{--fullscreen}, @samp{--maximized},
@samp{--fullwidth} or @samp{--fullheight}, some window managers require
you to set the variable @code{frame-resize-pixelwise} to a non-@code{nil}
value to make a frame appear truly maximized or full-screen.
Some window managers have options that can make them ignore both
program-specified and user-specified positions. If these are set,
Emacs fails to position the window correctly.
@node Borders X
@appendixsec Internal and External Borders
@cindex borders (X Window System)
An Emacs frame has an internal border and an external border. The
internal border is an extra strip of the background color around the
text portion of the frame. Emacs itself draws the internal border.
The external border is added by the window manager outside the frame;
depending on the window manager you use, it may contain various boxes
you can click on to move or iconify the window.
@table @samp
@item -ib @var{width}
@opindex -ib
@itemx --internal-border=@var{width}
@opindex --internal-border
@cindex internal border width, command-line argument
Specify @var{width} as the width of the internal border (between the text
and the main border), in pixels.
@item -bw @var{width}
@opindex -bw
@itemx --border-width=@var{width}
@opindex --border-width
@cindex main border width, command-line argument
Specify @var{width} as the width of the main border, in pixels.
@end table
When you specify the size of the frame, that does not count the
borders. The frame's position is measured from the outside edge of the
external border.
Use the @samp{-ib @var{n}} option to specify an internal border
@var{n} pixels wide. The default is 1. Use @samp{-bw @var{n}} to
specify the width of the external border (though the window manager may
not pay attention to what you specify). The default width of the
external border is 2.
@node Title X
@appendixsec Frame Titles
An Emacs frame may or may not have a specified title. The frame
title, if specified, appears in window decorations and icons as the
name of the frame. If an Emacs frame has no specified title, the
default title has the form @samp{@var{invocation-name}@@@var{machine}}
(if there is only one frame) or the selected window's buffer name (if
there is more than one frame).
You can specify a title for the initial Emacs frame with a command
line option:
@table @samp
@item -T @var{title}
@opindex -T
@itemx --title=@var{title}
@opindex --title
@cindex frame title, command-line argument
Specify @var{title} as the title for the initial Emacs frame.
@end table
The @samp{--name} option (@pxref{Resources}) also specifies the title
for the initial Emacs frame.
@node Icons X
@appendixsec Icons
@cindex icons (X Window System)
@cindex minimizing a frame at startup
@table @samp
@item -iconic
@opindex --iconic
@itemx --iconic
@cindex start iconified, command-line argument
Start Emacs in an iconified state.
@item -nbi
@opindex -nbi
@itemx --no-bitmap-icon
@opindex --no-bitmap-icon
@cindex Emacs icon, a gnu
Disable the use of the Emacs icon.
@end table
Most window managers allow you to iconify (or ``minimize'') an
Emacs frame, hiding it from sight. Some window managers replace
iconified windows with tiny icons, while others remove them
entirely from sight. The @samp{-iconic} option tells Emacs to begin
running in an iconified state, rather than showing a frame right away.
The text frame doesn't appear until you deiconify (or ``un-minimize'')
it.
By default, Emacs uses an icon containing the Emacs logo. On
desktop environments such as Gnome, this icon is also displayed in
other contexts, e.g., when switching into an Emacs frame. The
@samp{-nbi} or @samp{--no-bitmap-icon} option tells Emacs to let the
window manager choose what sort of icon to use---usually just a small
rectangle containing the frame's title.
@node Misc X
@appendixsec Other Display Options
@table @samp
@c @item -hb
@c @opindex -hb
@c @itemx --horizontal-scroll-bars
@c @opindex --horizontal-scroll-bars
@c @c @cindex horizontal scroll bars, command-line argument
@c Enable horizontal scroll bars. Since horizontal scroll bars
@c are not yet implemented, this actually does nothing.
@item --parent-id @var{id}
Open Emacs as a client X window via the XEmbed protocol, with @var{id}
as the parent X window id. Currently, this option is mainly useful
for developers.
@item -vb
@opindex -vb
@itemx --vertical-scroll-bars
@opindex --vertical-scroll-bars
@cindex vertical scroll bars, command-line argument
Enable vertical scroll bars.
@item -lsp @var{pixels}
@opindex -lsp
@itemx --line-spacing=@var{pixels}
@opindex --line-spacing
@cindex line spacing, command-line argument
Specify @var{pixels} as additional space to put between lines, in pixels.
@item -nbc
@opindex -nbc
@itemx --no-blinking-cursor
@opindex --no-blinking-cursor
@cindex blinking cursor disable, command-line argument
Disable the blinking cursor on graphical displays.
@item -D
@opindex -D
@itemx --basic-display
@opindex --basic-display
Disable the menu-bar, the tool-bar, the scroll-bars, and tool tips,
and turn off the blinking cursor. This can be useful for making a
test case that simplifies debugging of display problems.
@end table
The @samp{--xrm} option (@pxref{Resources}) specifies additional
X resource values.
|