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1 | @c -*-texinfo-*- |
2 | @c This is part of the GNU Emacs Lisp Reference Manual. | |
651f374c | 3 | @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 2002, 2003, 2004, |
ceb4c4d3 | 4 | @c 2005, 2006 Free Software Foundation, Inc. |
83ac6b45 RS |
5 | @c See the file elisp.texi for copying conditions. |
6 | @setfilename ../info/intro | |
7 | ||
e4a29e5a | 8 | @node Introduction, Lisp Data Types, Top, Top |
83ac6b45 | 9 | @comment node-name, next, previous, up |
83ac6b45 RS |
10 | @chapter Introduction |
11 | ||
12 | Most of the GNU Emacs text editor is written in the programming | |
13 | language called Emacs Lisp. You can write new code in Emacs Lisp and | |
14 | install it as an extension to the editor. However, Emacs Lisp is more | |
15 | than a mere ``extension language''; it is a full computer programming | |
16 | language in its own right. You can use it as you would any other | |
17 | programming language. | |
18 | ||
19 | Because Emacs Lisp is designed for use in an editor, it has special | |
20 | features for scanning and parsing text as well as features for handling | |
21 | files, buffers, displays, subprocesses, and so on. Emacs Lisp is | |
22 | closely integrated with the editing facilities; thus, editing commands | |
23 | are functions that can also conveniently be called from Lisp programs, | |
24 | and parameters for customization are ordinary Lisp variables. | |
25 | ||
a9f0a989 RS |
26 | This manual attempts to be a full description of Emacs Lisp. For a |
27 | beginner's introduction to Emacs Lisp, see @cite{An Introduction to | |
28 | Emacs Lisp Programming}, by Bob Chassell, also published by the Free | |
29 | Software Foundation. This manual presumes considerable familiarity with | |
30 | the use of Emacs for editing; see @cite{The GNU Emacs Manual} for this | |
31 | basic information. | |
32 | ||
33 | Generally speaking, the earlier chapters describe features of Emacs | |
34 | Lisp that have counterparts in many programming languages, and later | |
35 | chapters describe features that are peculiar to Emacs Lisp or relate | |
36 | specifically to editing. | |
83ac6b45 | 37 | |
4435c8d4 LK |
38 | This is edition @value{VERSION} of the GNU Emacs Lisp Reference |
39 | Manual, corresponding to Emacs version @value{EMACSVER}. | |
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40 | |
41 | @menu | |
42 | * Caveats:: Flaws and a request for help. | |
43 | * Lisp History:: Emacs Lisp is descended from Maclisp. | |
44 | * Conventions:: How the manual is formatted. | |
a9f0a989 | 45 | * Version Info:: Which Emacs version is running? |
83ac6b45 RS |
46 | * Acknowledgements:: The authors, editors, and sponsors of this manual. |
47 | @end menu | |
48 | ||
49 | @node Caveats | |
50 | @section Caveats | |
30db19b9 | 51 | @cindex bugs in this manual |
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52 | |
53 | This manual has gone through numerous drafts. It is nearly complete | |
7791402e RS |
54 | but not flawless. There are a few topics that are not covered, either |
55 | because we consider them secondary (such as most of the individual | |
56 | modes) or because they are yet to be written. Because we are not able | |
57 | to deal with them completely, we have left out several parts | |
58 | intentionally. This includes most information about usage on VMS. | |
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59 | |
60 | The manual should be fully correct in what it does cover, and it is | |
61 | therefore open to criticism on anything it says---from specific examples | |
62 | and descriptive text, to the ordering of chapters and sections. If | |
63 | something is confusing, or you find that you have to look at the sources | |
64 | or experiment to learn something not covered in the manual, then perhaps | |
65 | the manual should be fixed. Please let us know. | |
66 | ||
67 | @iftex | |
a40d4712 PR |
68 | As you use this manual, we ask that you mark pages with corrections so |
69 | you can later look them up and send them to us. If you think of a simple, | |
7791402e | 70 | real-life example for a function or group of functions, please make an |
83ac6b45 RS |
71 | effort to write it up and send it in. Please reference any comments to |
72 | the chapter name, section name, and function name, as appropriate, since | |
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73 | page numbers and chapter and section numbers will change and we may have |
74 | trouble finding the text you are talking about. Also state the number | |
75 | of the edition you are criticizing. | |
83ac6b45 | 76 | @end iftex |
37680279 | 77 | @ifnottex |
83ac6b45 RS |
78 | |
79 | As you use this manual, we ask that you send corrections as soon as you | |
80 | find them. If you think of a simple, real life example for a function | |
81 | or group of functions, please make an effort to write it up and send it | |
82 | in. Please reference any comments to the node name and function or | |
83 | variable name, as appropriate. Also state the number of the edition | |
a40d4712 | 84 | you are criticizing. |
37680279 | 85 | @end ifnottex |
83ac6b45 | 86 | |
5a6f4c95 RS |
87 | @cindex bugs |
88 | @cindex suggestions | |
83ac6b45 RS |
89 | Please mail comments and corrections to |
90 | ||
91 | @example | |
a9f0a989 | 92 | bug-lisp-manual@@gnu.org |
83ac6b45 RS |
93 | @end example |
94 | ||
95 | @noindent | |
96 | We let mail to this list accumulate unread until someone decides to | |
97 | apply the corrections. Months, and sometimes years, go by between | |
98 | updates. So please attach no significance to the lack of a reply---your | |
99 | mail @emph{will} be acted on in due time. If you want to contact the | |
100 | Emacs maintainers more quickly, send mail to | |
a9f0a989 | 101 | @code{bug-gnu-emacs@@gnu.org}. |
83ac6b45 | 102 | |
83ac6b45 RS |
103 | @node Lisp History |
104 | @section Lisp History | |
105 | @cindex Lisp history | |
106 | ||
a9f0a989 | 107 | Lisp (LISt Processing language) was first developed in the late 1950s |
83ac6b45 | 108 | at the Massachusetts Institute of Technology for research in artificial |
a9f0a989 | 109 | intelligence. The great power of the Lisp language makes it ideal |
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110 | for other purposes as well, such as writing editing commands. |
111 | ||
112 | @cindex Maclisp | |
113 | @cindex Common Lisp | |
114 | Dozens of Lisp implementations have been built over the years, each | |
115 | with its own idiosyncrasies. Many of them were inspired by Maclisp, | |
a9f0a989 | 116 | which was written in the 1960s at MIT's Project MAC. Eventually the |
7791402e | 117 | implementors of the descendants of Maclisp came together and developed a |
a9f0a989 | 118 | standard for Lisp systems, called Common Lisp. In the meantime, Gerry |
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119 | Sussman and Guy Steele at MIT developed a simplified but very powerful |
120 | dialect of Lisp, called Scheme. | |
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121 | |
122 | GNU Emacs Lisp is largely inspired by Maclisp, and a little by Common | |
123 | Lisp. If you know Common Lisp, you will notice many similarities. | |
a9f0a989 | 124 | However, many features of Common Lisp have been omitted or |
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125 | simplified in order to reduce the memory requirements of GNU Emacs. |
126 | Sometimes the simplifications are so drastic that a Common Lisp user | |
127 | might be very confused. We will occasionally point out how GNU Emacs | |
128 | Lisp differs from Common Lisp. If you don't know Common Lisp, don't | |
129 | worry about it; this manual is self-contained. | |
130 | ||
a9f0a989 RS |
131 | @pindex cl |
132 | A certain amount of Common Lisp emulation is available via the | |
0eeca3c1 | 133 | @file{cl} library. @inforef{Top, Overview, cl}. |
a9f0a989 | 134 | |
969fe9b5 | 135 | Emacs Lisp is not at all influenced by Scheme; but the GNU project has |
a9f0a989 RS |
136 | an implementation of Scheme, called Guile. We use Guile in all new GNU |
137 | software that calls for extensibility. | |
969fe9b5 | 138 | |
83ac6b45 RS |
139 | @node Conventions |
140 | @section Conventions | |
141 | ||
142 | This section explains the notational conventions that are used in this | |
143 | manual. You may want to skip this section and refer back to it later. | |
144 | ||
145 | @menu | |
146 | * Some Terms:: Explanation of terms we use in this manual. | |
147 | * nil and t:: How the symbols @code{nil} and @code{t} are used. | |
148 | * Evaluation Notation:: The format we use for examples of evaluation. | |
a9f0a989 | 149 | * Printing Notation:: The format we use when examples print text. |
83ac6b45 RS |
150 | * Error Messages:: The format we use for examples of errors. |
151 | * Buffer Text Notation:: The format we use for buffer contents in examples. | |
152 | * Format of Descriptions:: Notation for describing functions, variables, etc. | |
153 | @end menu | |
154 | ||
155 | @node Some Terms | |
156 | @subsection Some Terms | |
157 | ||
158 | Throughout this manual, the phrases ``the Lisp reader'' and ``the Lisp | |
a9f0a989 RS |
159 | printer'' refer to those routines in Lisp that convert textual |
160 | representations of Lisp objects into actual Lisp objects, and vice | |
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161 | versa. @xref{Printed Representation}, for more details. You, the |
162 | person reading this manual, are thought of as ``the programmer'' and are | |
827b7ee7 | 163 | addressed as ``you.'' ``The user'' is the person who uses Lisp |
a9f0a989 | 164 | programs, including those you write. |
83ac6b45 | 165 | |
d0789de9 | 166 | @cindex fonts in this manual |
8241495d RS |
167 | Examples of Lisp code are formatted like this: @code{(list 1 2 3)}. |
168 | Names that represent metasyntactic variables, or arguments to a function | |
169 | being described, are formatted like this: @var{first-number}. | |
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170 | |
171 | @node nil and t | |
172 | @subsection @code{nil} and @code{t} | |
173 | @cindex @code{nil}, uses of | |
174 | @cindex truth value | |
175 | @cindex boolean | |
176 | @cindex false | |
177 | ||
bfe721d1 | 178 | In Lisp, the symbol @code{nil} has three separate meanings: it |
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179 | is a symbol with the name @samp{nil}; it is the logical truth value |
180 | @var{false}; and it is the empty list---the list of zero elements. | |
181 | When used as a variable, @code{nil} always has the value @code{nil}. | |
182 | ||
183 | As far as the Lisp reader is concerned, @samp{()} and @samp{nil} are | |
184 | identical: they stand for the same object, the symbol @code{nil}. The | |
185 | different ways of writing the symbol are intended entirely for human | |
186 | readers. After the Lisp reader has read either @samp{()} or @samp{nil}, | |
187 | there is no way to determine which representation was actually written | |
188 | by the programmer. | |
189 | ||
d0789de9 RS |
190 | In this manual, we write @code{()} when we wish to emphasize that it |
191 | means the empty list, and we write @code{nil} when we wish to emphasize | |
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192 | that it means the truth value @var{false}. That is a good convention to use |
193 | in Lisp programs also. | |
194 | ||
195 | @example | |
196 | (cons 'foo ()) ; @r{Emphasize the empty list} | |
d0789de9 | 197 | (setq foo-flag nil) ; @r{Emphasize the truth value @var{false}} |
83ac6b45 RS |
198 | @end example |
199 | ||
0c6087a6 | 200 | @cindex @code{t}, uses of |
83ac6b45 RS |
201 | @cindex true |
202 | In contexts where a truth value is expected, any non-@code{nil} value | |
203 | is considered to be @var{true}. However, @code{t} is the preferred way | |
204 | to represent the truth value @var{true}. When you need to choose a | |
205 | value which represents @var{true}, and there is no other basis for | |
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206 | choosing, use @code{t}. The symbol @code{t} always has the value |
207 | @code{t}. | |
83ac6b45 RS |
208 | |
209 | In Emacs Lisp, @code{nil} and @code{t} are special symbols that always | |
210 | evaluate to themselves. This is so that you do not need to quote them | |
211 | to use them as constants in a program. An attempt to change their | |
0c6087a6 | 212 | values results in a @code{setting-constant} error. @xref{Constant |
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213 | Variables}. |
214 | ||
0ccc83d9 SM |
215 | @defun booleanp object |
216 | Return non-nil iff @var{object} is one of the two canonical boolean | |
217 | values: @code{t} or @code{nil}. | |
218 | @end defun | |
219 | ||
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220 | @node Evaluation Notation |
221 | @subsection Evaluation Notation | |
222 | @cindex evaluation notation | |
223 | @cindex documentation notation | |
0c6087a6 | 224 | @cindex notation |
83ac6b45 RS |
225 | |
226 | A Lisp expression that you can evaluate is called a @dfn{form}. | |
227 | Evaluating a form always produces a result, which is a Lisp object. In | |
228 | the examples in this manual, this is indicated with @samp{@result{}}: | |
229 | ||
230 | @example | |
231 | (car '(1 2)) | |
232 | @result{} 1 | |
233 | @end example | |
234 | ||
235 | @noindent | |
827b7ee7 | 236 | You can read this as ``@code{(car '(1 2))} evaluates to 1.'' |
83ac6b45 RS |
237 | |
238 | When a form is a macro call, it expands into a new form for Lisp to | |
239 | evaluate. We show the result of the expansion with | |
a9f0a989 | 240 | @samp{@expansion{}}. We may or may not show the result of the |
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241 | evaluation of the expanded form. |
242 | ||
243 | @example | |
244 | (third '(a b c)) | |
245 | @expansion{} (car (cdr (cdr '(a b c)))) | |
246 | @result{} c | |
247 | @end example | |
248 | ||
7791402e | 249 | Sometimes to help describe one form we show another form that |
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250 | produces identical results. The exact equivalence of two forms is |
251 | indicated with @samp{@equiv{}}. | |
252 | ||
253 | @example | |
254 | (make-sparse-keymap) @equiv{} (list 'keymap) | |
255 | @end example | |
256 | ||
257 | @node Printing Notation | |
258 | @subsection Printing Notation | |
259 | @cindex printing notation | |
260 | ||
261 | Many of the examples in this manual print text when they are | |
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262 | evaluated. If you execute example code in a Lisp Interaction buffer |
263 | (such as the buffer @samp{*scratch*}), the printed text is inserted into | |
264 | the buffer. If you execute the example by other means (such as by | |
265 | evaluating the function @code{eval-region}), the printed text is | |
79ddc9c9 | 266 | displayed in the echo area. |
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267 | |
268 | Examples in this manual indicate printed text with @samp{@print{}}, | |
8f40a868 RS |
269 | irrespective of where that text goes. The value returned by |
270 | evaluating the form (here @code{bar}) follows on a separate line with | |
271 | @samp{@result{}}. | |
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272 | |
273 | @example | |
274 | @group | |
5bacf5b6 | 275 | (progn (prin1 'foo) (princ "\n") (prin1 'bar)) |
83ac6b45 RS |
276 | @print{} foo |
277 | @print{} bar | |
278 | @result{} bar | |
279 | @end group | |
280 | @end example | |
281 | ||
282 | @node Error Messages | |
283 | @subsection Error Messages | |
284 | @cindex error message notation | |
285 | ||
286 | Some examples signal errors. This normally displays an error message | |
287 | in the echo area. We show the error message on a line starting with | |
288 | @samp{@error{}}. Note that @samp{@error{}} itself does not appear in | |
289 | the echo area. | |
290 | ||
291 | @example | |
292 | (+ 23 'x) | |
f9f59935 | 293 | @error{} Wrong type argument: number-or-marker-p, x |
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294 | @end example |
295 | ||
296 | @node Buffer Text Notation | |
297 | @subsection Buffer Text Notation | |
298 | @cindex buffer text notation | |
299 | ||
8241495d RS |
300 | Some examples describe modifications to the contents of a buffer, by |
301 | showing the ``before'' and ``after'' versions of the text. These | |
302 | examples show the contents of the buffer in question between two lines | |
303 | of dashes containing the buffer name. In addition, @samp{@point{}} | |
304 | indicates the location of point. (The symbol for point, of course, is | |
305 | not part of the text in the buffer; it indicates the place | |
306 | @emph{between} two characters where point is currently located.) | |
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307 | |
308 | @example | |
309 | ---------- Buffer: foo ---------- | |
310 | This is the @point{}contents of foo. | |
311 | ---------- Buffer: foo ---------- | |
312 | ||
313 | (insert "changed ") | |
314 | @result{} nil | |
315 | ---------- Buffer: foo ---------- | |
316 | This is the changed @point{}contents of foo. | |
317 | ---------- Buffer: foo ---------- | |
318 | @end example | |
319 | ||
320 | @node Format of Descriptions | |
321 | @subsection Format of Descriptions | |
322 | @cindex description format | |
323 | ||
324 | Functions, variables, macros, commands, user options, and special | |
325 | forms are described in this manual in a uniform format. The first | |
326 | line of a description contains the name of the item followed by its | |
327 | arguments, if any. | |
37680279 | 328 | @ifnottex |
83ac6b45 RS |
329 | The category---function, variable, or whatever---appears at the |
330 | beginning of the line. | |
37680279 | 331 | @end ifnottex |
83ac6b45 RS |
332 | @iftex |
333 | The category---function, variable, or whatever---is printed next to the | |
334 | right margin. | |
335 | @end iftex | |
336 | The description follows on succeeding lines, sometimes with examples. | |
337 | ||
338 | @menu | |
339 | * A Sample Function Description:: A description of an imaginary | |
340 | function, @code{foo}. | |
341 | * A Sample Variable Description:: A description of an imaginary | |
342 | variable, | |
177c0ea7 | 343 | @code{electric-future-map}. |
83ac6b45 RS |
344 | @end menu |
345 | ||
346 | @node A Sample Function Description | |
347 | @subsubsection A Sample Function Description | |
348 | @cindex function descriptions | |
349 | @cindex command descriptions | |
350 | @cindex macro descriptions | |
351 | @cindex special form descriptions | |
352 | ||
353 | In a function description, the name of the function being described | |
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354 | appears first. It is followed on the same line by a list of argument |
355 | names. These names are also used in the body of the description, to | |
356 | stand for the values of the arguments. | |
83ac6b45 | 357 | |
969fe9b5 RS |
358 | The appearance of the keyword @code{&optional} in the argument list |
359 | indicates that the subsequent arguments may be omitted (omitted | |
360 | arguments default to @code{nil}). Do not write @code{&optional} when | |
361 | you call the function. | |
83ac6b45 | 362 | |
0c6087a6 RS |
363 | The keyword @code{&rest} (which must be followed by a single |
364 | argument name) indicates that any number of arguments can follow. The | |
365 | single argument name following @code{&rest} will receive, as its | |
366 | value, a list of all the remaining arguments passed to the function. | |
367 | Do not write @code{&rest} when you call the function. | |
83ac6b45 RS |
368 | |
369 | Here is a description of an imaginary function @code{foo}: | |
370 | ||
371 | @defun foo integer1 &optional integer2 &rest integers | |
372 | The function @code{foo} subtracts @var{integer1} from @var{integer2}, | |
373 | then adds all the rest of the arguments to the result. If @var{integer2} | |
374 | is not supplied, then the number 19 is used by default. | |
375 | ||
376 | @example | |
377 | (foo 1 5 3 9) | |
378 | @result{} 16 | |
379 | (foo 5) | |
380 | @result{} 14 | |
381 | @end example | |
382 | ||
7dd3d99f | 383 | @need 1500 |
83ac6b45 RS |
384 | More generally, |
385 | ||
386 | @example | |
387 | (foo @var{w} @var{x} @var{y}@dots{}) | |
388 | @equiv{} | |
389 | (+ (- @var{x} @var{w}) @var{y}@dots{}) | |
390 | @end example | |
391 | @end defun | |
392 | ||
969fe9b5 | 393 | Any argument whose name contains the name of a type (e.g., |
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394 | @var{integer}, @var{integer1} or @var{buffer}) is expected to be of that |
395 | type. A plural of a type (such as @var{buffers}) often means a list of | |
969fe9b5 RS |
396 | objects of that type. Arguments named @var{object} may be of any type. |
397 | (@xref{Lisp Data Types}, for a list of Emacs object types.) Arguments | |
398 | with other sorts of names (e.g., @var{new-file}) are discussed | |
399 | specifically in the description of the function. In some sections, | |
400 | features common to the arguments of several functions are described at | |
401 | the beginning. | |
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402 | |
403 | @xref{Lambda Expressions}, for a more complete description of optional | |
404 | and rest arguments. | |
405 | ||
406 | Command, macro, and special form descriptions have the same format, | |
407 | but the word `Function' is replaced by `Command', `Macro', or `Special | |
408 | Form', respectively. Commands are simply functions that may be called | |
409 | interactively; macros process their arguments differently from functions | |
410 | (the arguments are not evaluated), but are presented the same way. | |
411 | ||
412 | Special form descriptions use a more complex notation to specify | |
969fe9b5 | 413 | optional and repeated arguments because they can break the argument |
83ac6b45 | 414 | list down into separate arguments in more complicated ways. |
a9f0a989 | 415 | @samp{@r{[}@var{optional-arg}@r{]}} means that @var{optional-arg} is |
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416 | optional and @samp{@var{repeated-args}@dots{}} stands for zero or more |
417 | arguments. Parentheses are used when several arguments are grouped into | |
418 | additional levels of list structure. Here is an example: | |
419 | ||
420 | @defspec count-loop (@var{var} [@var{from} @var{to} [@var{inc}]]) @var{body}@dots{} | |
421 | This imaginary special form implements a loop that executes the | |
422 | @var{body} forms and then increments the variable @var{var} on each | |
423 | iteration. On the first iteration, the variable has the value | |
a9f0a989 | 424 | @var{from}; on subsequent iterations, it is incremented by one (or by |
83ac6b45 RS |
425 | @var{inc} if that is given). The loop exits before executing @var{body} |
426 | if @var{var} equals @var{to}. Here is an example: | |
427 | ||
428 | @example | |
429 | (count-loop (i 0 10) | |
430 | (prin1 i) (princ " ") | |
969fe9b5 RS |
431 | (prin1 (aref vector i)) |
432 | (terpri)) | |
83ac6b45 RS |
433 | @end example |
434 | ||
a9f0a989 | 435 | If @var{from} and @var{to} are omitted, @var{var} is bound to |
83ac6b45 RS |
436 | @code{nil} before the loop begins, and the loop exits if @var{var} is |
437 | non-@code{nil} at the beginning of an iteration. Here is an example: | |
438 | ||
439 | @example | |
440 | (count-loop (done) | |
441 | (if (pending) | |
442 | (fixit) | |
443 | (setq done t))) | |
444 | @end example | |
445 | ||
446 | In this special form, the arguments @var{from} and @var{to} are | |
447 | optional, but must both be present or both absent. If they are present, | |
448 | @var{inc} may optionally be specified as well. These arguments are | |
449 | grouped with the argument @var{var} into a list, to distinguish them | |
450 | from @var{body}, which includes all remaining elements of the form. | |
451 | @end defspec | |
452 | ||
453 | @node A Sample Variable Description | |
454 | @subsubsection A Sample Variable Description | |
455 | @cindex variable descriptions | |
456 | @cindex option descriptions | |
457 | ||
0c6087a6 RS |
458 | A @dfn{variable} is a name that can hold a value. Although nearly |
459 | all variables can be set by the user, certain variables exist | |
460 | specifically so that users can change them; these are called @dfn{user | |
83ac6b45 RS |
461 | options}. Ordinary variables and user options are described using a |
462 | format like that for functions except that there are no arguments. | |
463 | ||
464 | Here is a description of the imaginary @code{electric-future-map} | |
465 | variable.@refill | |
466 | ||
467 | @defvar electric-future-map | |
468 | The value of this variable is a full keymap used by Electric Command | |
469 | Future mode. The functions in this map allow you to edit commands you | |
470 | have not yet thought about executing. | |
471 | @end defvar | |
472 | ||
473 | User option descriptions have the same format, but `Variable' is | |
474 | replaced by `User Option'. | |
475 | ||
969fe9b5 RS |
476 | @node Version Info |
477 | @section Version Information | |
478 | ||
a9f0a989 RS |
479 | These facilities provide information about which version of Emacs is |
480 | in use. | |
969fe9b5 | 481 | |
8bbf587d | 482 | @deffn Command emacs-version &optional here |
969fe9b5 RS |
483 | This function returns a string describing the version of Emacs that is |
484 | running. It is useful to include this string in bug reports. | |
485 | ||
a9f0a989 | 486 | @smallexample |
969fe9b5 RS |
487 | @group |
488 | (emacs-version) | |
489 | @result{} "GNU Emacs 20.3.5 (i486-pc-linux-gnulibc1, X toolkit) | |
490 | of Sat Feb 14 1998 on psilocin.gnu.org" | |
491 | @end group | |
a9f0a989 | 492 | @end smallexample |
969fe9b5 | 493 | |
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494 | If @var{here} is non-@code{nil}, it inserts the text in the buffer |
495 | before point, and returns @code{nil}. Called interactively, the | |
496 | function prints the same information in the echo area, but giving a | |
497 | prefix argument makes @var{here} non-@code{nil}. | |
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498 | @end deffn |
499 | ||
500 | @defvar emacs-build-time | |
a9f0a989 RS |
501 | The value of this variable indicates the time at which Emacs was built |
502 | at the local site. It is a list of three integers, like the value | |
503 | of @code{current-time} (@pxref{Time of Day}). | |
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504 | |
505 | @example | |
506 | @group | |
507 | emacs-build-time | |
a9f0a989 | 508 | @result{} (13623 62065 344633) |
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509 | @end group |
510 | @end example | |
511 | @end defvar | |
512 | ||
513 | @defvar emacs-version | |
514 | The value of this variable is the version of Emacs being run. It is a | |
515 | string such as @code{"20.3.1"}. The last number in this string is not | |
516 | really part of the Emacs release version number; it is incremented each | |
aab28c42 | 517 | time you build Emacs in any given directory. A value with four numeric |
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518 | components, such as @code{"20.3.9.1"}, indicates an unreleased test |
519 | version. | |
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520 | @end defvar |
521 | ||
a9f0a989 | 522 | The following two variables have existed since Emacs version 19.23: |
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523 | |
524 | @defvar emacs-major-version | |
525 | The major version number of Emacs, as an integer. For Emacs version | |
526 | 20.3, the value is 20. | |
527 | @end defvar | |
528 | ||
529 | @defvar emacs-minor-version | |
530 | The minor version number of Emacs, as an integer. For Emacs version | |
531 | 20.3, the value is 3. | |
532 | @end defvar | |
533 | ||
83ac6b45 RS |
534 | @node Acknowledgements |
535 | @section Acknowledgements | |
536 | ||
537 | This manual was written by Robert Krawitz, Bil Lewis, Dan LaLiberte, | |
538 | Richard M. Stallman and Chris Welty, the volunteers of the GNU manual | |
539 | group, in an effort extending over several years. Robert J. Chassell | |
540 | helped to review and edit the manual, with the support of the Defense | |
541 | Advanced Research Projects Agency, ARPA Order 6082, arranged by Warren | |
a40d4712 | 542 | A. Hunt, Jr.@: of Computational Logic, Inc. |
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543 | |
544 | Corrections were supplied by Karl Berry, Jim Blandy, Bard Bloom, | |
545 | Stephane Boucher, David Boyes, Alan Carroll, Richard Davis, Lawrence | |
546 | R. Dodd, Peter Doornbosch, David A. Duff, Chris Eich, Beverly | |
547 | Erlebacher, David Eckelkamp, Ralf Fassel, Eirik Fuller, Stephen Gildea, | |
548 | Bob Glickstein, Eric Hanchrow, George Hartzell, Nathan Hess, Masayuki | |
549 | Ida, Dan Jacobson, Jak Kirman, Bob Knighten, Frederick M. Korz, Joe | |
550 | Lammens, Glenn M. Lewis, K. Richard Magill, Brian Marick, Roland | |
551 | McGrath, Skip Montanaro, John Gardiner Myers, Thomas A. Peterson, | |
552 | Francesco Potorti, Friedrich Pukelsheim, Arnold D. Robbins, Raul | |
a40d4712 | 553 | Rockwell, Per Starb@"ack, Shinichirou Sugou, Kimmo Suominen, Edward Tharp, |
83ac6b45 RS |
554 | Bill Trost, Rickard Westman, Jean White, Matthew Wilding, Carl Witty, |
555 | Dale Worley, Rusty Wright, and David D. Zuhn. | |
ab5796a9 MB |
556 | |
557 | @ignore | |
558 | arch-tag: d156593f-82f8-4708-a844-204e48f7f2aa | |
559 | @end ignore |