| 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 | @end menu |
| 64 | |
| 65 | @node Action Arguments |
| 66 | @appendixsec Action Arguments |
| 67 | |
| 68 | Here is a table of the action arguments and options: |
| 69 | |
| 70 | @table @samp |
| 71 | @item @var{file} |
| 72 | @opindex --visit |
| 73 | @itemx --visit=@var{file} |
| 74 | @opindex --file |
| 75 | @itemx --file=@var{file} |
| 76 | @cindex visiting files, command-line argument |
| 77 | Visit @var{file} using @code{find-file}. @xref{Visiting}. |
| 78 | |
| 79 | @item +@var{linenum} @var{file} |
| 80 | @opindex +@var{linenum} |
| 81 | Visit @var{file} using @code{find-file}, then go to line number |
| 82 | @var{linenum} in it. |
| 83 | |
| 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}. |
| 87 | |
| 88 | @need 3000 |
| 89 | @item -l @var{file} |
| 90 | @opindex -l |
| 91 | @itemx --load=@var{file} |
| 92 | @opindex --load |
| 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}). |
| 98 | |
| 99 | @item -f @var{function} |
| 100 | @opindex -f |
| 101 | @itemx --funcall=@var{function} |
| 102 | @opindex --funcall |
| 103 | @cindex call Lisp functions, command-line argument |
| 104 | Call Lisp function @var{function} with no arguments. |
| 105 | |
| 106 | @item --eval=@var{expression} |
| 107 | @opindex --eval |
| 108 | @itemx --execute=@var{expression} |
| 109 | @opindex --execute |
| 110 | @cindex evaluate expression, command-line argument |
| 111 | Evaluate Lisp expression @var{expression}. |
| 112 | |
| 113 | @item --insert=@var{file} |
| 114 | @opindex --insert |
| 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}. |
| 118 | |
| 119 | @item --kill |
| 120 | @opindex --kill |
| 121 | Exit from Emacs without asking for confirmation. |
| 122 | @end table |
| 123 | |
| 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. |
| 129 | |
| 130 | @node Initial Options |
| 131 | @appendixsec Initial Options |
| 132 | |
| 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 |
| 136 | sections. |
| 137 | |
| 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. |
| 143 | |
| 144 | @table @samp |
| 145 | @item -t @var{device} |
| 146 | @opindex -t |
| 147 | @itemx --terminal=@var{device} |
| 148 | @opindex --terminal |
| 149 | @cindex device for Emacs terminal I/O |
| 150 | Use @var{device} as the device for terminal input and output. |
| 151 | |
| 152 | @item -d @var{display} |
| 153 | @opindex -d |
| 154 | @itemx --display=@var{display} |
| 155 | @opindex --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. |
| 159 | |
| 160 | @item -nw |
| 161 | @opindex -nw |
| 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 |
| 168 | and input. |
| 169 | |
| 170 | @need 3000 |
| 171 | @cindex batch mode |
| 172 | @item -batch |
| 173 | @opindex --batch |
| 174 | @itemx --batch |
| 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}. |
| 181 | |
| 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. |
| 186 | |
| 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. |
| 191 | |
| 192 | @item -q |
| 193 | @opindex -q |
| 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}. |
| 203 | |
| 204 | @item --no-site-file |
| 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. |
| 210 | |
| 211 | @item -u @var{user} |
| 212 | @opindex -u |
| 213 | @itemx --user=@var{user} |
| 214 | @opindex --user |
| 215 | @cindex load init file of another user |
| 216 | Load @var{user}'s Emacs init file @file{~@var{user}/.emacs} instead of |
| 217 | your own. |
| 218 | |
| 219 | @item --debug-init |
| 220 | @opindex --debug-init |
| 221 | @cindex errors in init file |
| 222 | Enable the Emacs Lisp debugger for errors in the init file. |
| 223 | |
| 224 | @item --unibyte |
| 225 | @opindex --unibyte |
| 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. |
| 233 | |
| 234 | @item --multibyte |
| 235 | @opindex --multibyte |
| 236 | Inhibit the effect of @env{EMACS_UNIBYTE}, so that Emacs |
| 237 | uses multibyte characters by default, as usual. |
| 238 | @end table |
| 239 | |
| 240 | @node Command Example |
| 241 | @appendixsec Command Argument Example |
| 242 | |
| 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 |
| 246 | to be a C program. |
| 247 | |
| 248 | @example |
| 249 | emacs -batch foo.c -l hack-c -f save-buffer >& log |
| 250 | @end example |
| 251 | |
| 252 | @noindent |
| 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 |
| 259 | to work with. |
| 260 | |
| 261 | @node Resume Arguments |
| 262 | @appendixsec Resuming Emacs with Arguments |
| 263 | |
| 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}): |
| 267 | |
| 268 | @c `resume-suspend-hook' is correct. It is the name of a function. |
| 269 | @example |
| 270 | (add-hook 'suspend-hook 'resume-suspend-hook) |
| 271 | (add-hook 'suspend-resume-hook 'resume-process-args) |
| 272 | @end example |
| 273 | |
| 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. |
| 280 | |
| 281 | Only action arguments work properly when you resume Emacs. Initial |
| 282 | arguments are not recognized---it's too late to execute them anyway. |
| 283 | |
| 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 |
| 291 | Server}). |
| 292 | |
| 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 |
| 298 | file and delete it. |
| 299 | |
| 300 | @node Environment |
| 301 | @appendixsec Environment Variables |
| 302 | @cindex environment variables |
| 303 | |
| 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. |
| 309 | |
| 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. |
| 316 | |
| 317 | @findex setenv |
| 318 | @findex getenv |
| 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: |
| 325 | |
| 326 | @example |
| 327 | export ORGANIZATION="not very much" |
| 328 | @end example |
| 329 | |
| 330 | @noindent |
| 331 | and here's how to do it in csh or tcsh: |
| 332 | |
| 333 | @example |
| 334 | setenv ORGANIZATION "not very much" |
| 335 | @end example |
| 336 | |
| 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. |
| 340 | |
| 341 | @menu |
| 342 | * General Variables:: Environment variables that all versions of Emacs use. |
| 343 | * Misc Variables:: Certain system-specific variables. |
| 344 | @end menu |
| 345 | |
| 346 | @node General Variables |
| 347 | @appendixsubsec General Variables |
| 348 | |
| 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. |
| 354 | |
| 355 | @table @env |
| 356 | @item CDPATH |
| 357 | Used by the @code{cd} command to search for the directory you specify, |
| 358 | when you specify a relative directory name. |
| 359 | @item EMACS_UNIBYTE |
| 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}. |
| 365 | @item EMACSDATA |
| 366 | Directory for the architecture-independent files that come with Emacs. |
| 367 | This is used to initialize the Lisp variable @code{data-directory}. |
| 368 | @item EMACSDOC |
| 369 | Directory for the documentation string file, |
| 370 | @file{DOC-@var{emacsversion}}. This is used to initialize the Lisp |
| 371 | variable @code{doc-directory}. |
| 372 | @item EMACSLOADPATH |
| 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}. |
| 379 | @item EMACSPATH |
| 380 | A colon-separated list of directories to search for executable |
| 381 | files---used to initialize @code{exec-path}. |
| 382 | @item ESHELL |
| 383 | Used for shell-mode to override the @env{SHELL} environment variable. |
| 384 | @item HISTFILE |
| 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} |
| 388 | otherwise. |
| 389 | @item HOME |
| 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:}. |
| 395 | @item HOSTNAME |
| 396 | The name of the machine that Emacs is running on. |
| 397 | @item INCPATH |
| 398 | A colon-separated list of directories. Used by the @code{complete} package |
| 399 | to search for files. |
| 400 | @item INFOPATH |
| 401 | A colon-separated list of directories in which to search for Info files. |
| 402 | @item LC_ALL |
| 403 | @itemx LC_COLLATE |
| 404 | @itemx LC_CTYPE |
| 405 | @itemx LC_MESSAGES |
| 406 | @itemx LC_MONETARY |
| 407 | @itemx LC_NUMERIC |
| 408 | @itemx LC_TIME |
| 409 | @itemx LANG |
| 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. |
| 419 | |
| 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}. |
| 425 | @item LOGNAME |
| 426 | The user's login name. See also @env{USER}. |
| 427 | @item MAIL |
| 428 | The name of the user's system mail inbox. |
| 429 | @item MAILRC |
| 430 | Name of file containing mail aliases. (The default is |
| 431 | @file{~/.mailrc}.) |
| 432 | @item MH |
| 433 | Name of setup file for the mh system. (The default is @file{~/.mh_profile}.) |
| 434 | @item NAME |
| 435 | The real-world name of the user. |
| 436 | @item NNTPSERVER |
| 437 | The name of the news server. Used by the mh and Gnus packages. |
| 438 | @item ORGANIZATION |
| 439 | The name of the organization to which you belong. Used for setting the |
| 440 | `Organization:' header in your posts from the Gnus package. |
| 441 | @item PATH |
| 442 | A colon-separated list of directories in which executables reside. This |
| 443 | is used to initialize the Emacs Lisp variable @code{exec-path}. |
| 444 | @item PWD |
| 445 | If set, this should be the default directory when Emacs was started. |
| 446 | @item REPLYTO |
| 447 | If set, this specifies an initial value for the variable |
| 448 | @code{mail-default-reply-to}. @xref{Mail Headers}. |
| 449 | @item SAVEDIR |
| 450 | The name of a directory in which news articles are saved by default. |
| 451 | Used by the Gnus package. |
| 452 | @item SHELL |
| 453 | The name of an interpreter used to parse and execute programs run from |
| 454 | inside Emacs. |
| 455 | @cindex background mode, on @code{xterm} |
| 456 | @item TERM |
| 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. |
| 464 | @item TERMCAP |
| 465 | The name of the termcap library file describing how to program the |
| 466 | terminal specified by the @env{TERM} variable. This defaults to |
| 467 | @file{/etc/termcap}. |
| 468 | @item TMPDIR |
| 469 | Used by the Emerge package as a prefix for temporary files. |
| 470 | @item TZ |
| 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. |
| 476 | @item USER |
| 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 |
| 481 | Names}). |
| 482 | @end table |
| 483 | |
| 484 | @node Misc Variables |
| 485 | @appendixsubsec Miscellaneous Variables |
| 486 | |
| 487 | These variables are used only on particular configurations: |
| 488 | |
| 489 | @table @env |
| 490 | @item COMSPEC |
| 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 |
| 494 | variable. |
| 495 | |
| 496 | @item NAME |
| 497 | On MS-DOS, this variable defaults to the value of the @env{USER} |
| 498 | variable. |
| 499 | |
| 500 | @item TEMP |
| 501 | @itemx TMP |
| 502 | On MS-DOS and MS-Windows, these specify the name of the directory for |
| 503 | storing temporary files in. |
| 504 | |
| 505 | @item EMACSTEST |
| 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 |
| 508 | reports. |
| 509 | |
| 510 | @item EMACSCOLORS |
| 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. |
| 514 | |
| 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. |
| 522 | |
| 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 |
| 526 | actually used. |
| 527 | |
| 528 | @item WINDOW_GFX |
| 529 | Used when initializing the Sun windows system. |
| 530 | @end table |