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1 GNU Emacs NEWS -- history of user-visible changes. 17-Aug-1988
2 Copyright (C) 1988 Free Software Foundation, Inc.
3 See the end for copying conditions.
4
5 For older news, see the file ONEWS.2.
6 \f
7 Changes in version 18.52.
8
9 * X windows version 10 is supported under system V.
10
11 * Pop-up menus are now supported with the same Lisp interface in
12 both version 10 and 11 of X windows.
13
14 * C-x 4 a is a new command to edit a change-log entry in another window.
15
16 * The emacs client program now allows an option +NNN to specify the
17 line number to go to in the file whose name follows. Thus,
18 emacsclient foo.c +45 bar.c
19 will find the files `foo.c' and `bar.c', going to line 45 in `bar.c'.
20
21 * Dired allows empty directories to be deleted like files.
22
23 * When the terminal type is used to find a terminal-specific file to
24 run, Emacs now tries the entire terminal type first. If that doesn't
25 yield a file that exists, the last hyphen and what follows it is
26 stripped. If that doesn't yield a file that exists, the previous
27 hyphen is stripped, and so on until all hyphens are gone. For
28 example, if the terminal type is `aaa-48-foo', Emacs will try first
29 `term/aaa-48-foo.el', then `term/aaa-48.el' and finally `term/aaa.el'.
30
31 Underscores now receive the same treatment as hyphens.
32
33 * Texinfo features: @defun, etc. texinfo-show-structure.
34 New template commands. texinfo-format-region.
35
36 * The special "local variable" `eval' is now ignored if you are running
37 as root.
38
39 * New command `c-macro-expand' shows the result of C macro expansion
40 in the region. It works using the C preprocessor, so its results
41 are completely accurate.
42
43 * Errors in trying to auto save now flash error messages for a few seconds.
44
45 * Killing a buffer now sends SIGHUP to the buffer's process.
46
47 * New hooks.
48
49 ** `spell-region' now allows you to filter the text before spelling-checking.
50 If the value of `spell-filter' is non-nil, it is called, with no arguments,
51 looking at a temporary buffer containing a copy of the text to be checked.
52 It can alter the text freely before the spell program sees it.
53
54 ** The variable `lpr-command' now specifies the command to be used when
55 you use the commands to print text (such as M-x print-buffer).
56
57 ** Posting netnews now calls the value of `news-inews-hook' (if not nil)
58 as a function of no arguments before the actual posting.
59
60 ** Rmail now calls the value of `rmail-show-message-hook' (if not nil)
61 as a function of no arguments, each time a new message is selected.
62
63 ** `kill-emacs' calls the value of `kill-emacs-hook' as a function of no args.
64
65 * New libraries.
66 See the source code of each library for more information.
67
68 ** icon.el: a major mode for editing programs written in Icon.
69
70 ** life.el: a simulator for the cellular automaton "life". Load the
71 library and run M-x life.
72
73 ** doctex.el: a library for converting the Emacs `etc/DOC' file of
74 documentation strings into TeX input.
75
76 ** saveconf.el: a library which records the arrangement of windows and
77 buffers when you exit Emacs, and automatically recreates the same
78 setup the next time you start Emacs.
79
80 ** uncompress.el: a library that automatically uncompresses files
81 when you visit them.
82
83 ** c-fill.el: a mode for editing filled comments in C.
84
85 ** kermit.el: an extended version of shell-mode designed for running kermit.
86
87 ** spook.el: a library for adding some "distract the NSA" keywords to every
88 message you send.
89
90 ** hideif.el: a library for hiding parts of a C program based on preprocessor
91 conditionals.
92
93 ** autoinsert.el: a library to put in some initial text when you visit
94 a nonexistent file. The text used depends on the major mode, and
95 comes from a directory of files created by you.
96
97 * New programming features.
98
99 ** The variable `window-system-version' now contains the version number
100 of the window system you are using (if appropriate). When using X windows,
101 its value is either 10 or 11.
102
103 ** (interactive "N") uses the prefix argument if any; otherwise, it reads
104 a number using the minibuffer.
105
106 ** VMS: there are two new functions `vms-system-info' and `shrink-to-icon'.
107 The former allows you to get many kinds of system status information.
108 See its self-documentation for full details.
109 The second is used with the window system: it iconifies the Emacs window.
110
111 ** VMS: the new function `define-logical-name' allows you to create
112 job-wide logical names. The old function `define-dcl-symbol' has been
113 removed.
114 \f
115 Changes in version 18.50.
116
117 * X windows version 11 is supported.
118
119 Define X11 in config.h if you want X version 11 instead of version 10.
120
121 * The command M-x gdb runs the GDB debugger as an inferior.
122 It asks for the filename of the executable you want to debug.
123
124 GDB runs as an inferior with I/O through an Emacs buffer. All the
125 facilities of Shell mode are available. In addition, each time your
126 program stops, and each time you select a new stack frame, the source
127 code is displayed in another window with an arrow added to the line
128 where the program is executing.
129
130 Special GDB-mode commands include M-s, M-n, M-i, M-u, M-d, and C-c C-f
131 which send the GDB commands `step', `next', `stepi', `up', `down'
132 and `finish'.
133
134 In any source file, the commands C-x SPC tells GDB to set a breakpoint
135 on the current line.
136
137 * M-x calendar displays a three-month calendar.
138
139 * C-u 0 C-x C-s never makes a backup file.
140
141 This is a way you can explicitly request not to make a backup.
142
143 * `term-setup-hook' is for users only.
144
145 Emacs never uses this variable for internal purposes, so you can freely
146 set it in your `.emacs' file to make Emacs do something special after
147 loading any terminal-specific setup file from `lisp/term'.
148
149 * `copy-keymap' now copies recursive submaps.
150
151 * New overlay-arrow feature.
152
153 If you set the variable `overlay-arrow-string' to a string
154 and `overlay-arrow-position' to a marker, that string is displayed on
155 the screen at the position of that marker, hiding whatever text would
156 have appeared there. If that position isn't on the screen, or if
157 the buffer the marker points into isn't displayed, there is no effect.
158
159 * -batch mode can read from the terminal.
160
161 It now works to use `read-char' to do terminal input in a noninteractive
162 Emacs run. End of file causes Emacs to exit.
163
164 * Variables `data-bytes-used' and `data-bytes-free' removed.
165
166 These variables cannot really work because the 24-bit range of an
167 integer in (most ports of) GNU Emacs is not large enough to hold their
168 values on many systems.
169 \f
170 Changes in version 18.45, since version 18.41.
171
172 * C indentation parameter `c-continued-brace-offset'.
173
174 This parameter's value is added to the indentation of any
175 line that is in a continuation context and starts with an open-brace.
176 For example, it applies to the open brace shown here:
177
178 if (x)
179 {
180
181 The default value is zero.
182
183 * Dabbrev expansion (Meta-/) preserves case.
184
185 When you use Meta-/ to search the buffer for an expansion of an
186 abbreviation, if the expansion found is all lower case except perhaps
187 for its first letter, then the case pattern of the abbreviation
188 is carried over to the expansion that replaces it.
189
190 * TeX-mode syntax.
191
192 \ is no longer given "escape character" syntax in TeX mode. It now
193 has the syntax of an ordinary punctuation character. As a result,
194 \[...\] and such like are considered to balance each other.
195
196 * Mail-mode automatic Reply-to field.
197
198 If the variable `mail-default-reply-to' is non-`nil', then each time
199 you start to compose a message, a Reply-to field is inserted with
200 its contents taken from the value of `mail-default-reply-to'.
201
202 * Where is your .emacs file?
203
204 If you run Emacs under `su', so your real and effective uids are
205 different, Emacs uses the home directory associated with the real uid
206 (the name you actually logged in under) to find the .emacs file.
207
208 Otherwise, Emacs uses the environment variable HOME to find the .emacs
209 file.
210
211 The .emacs file is not loaded at all if -batch is specified.
212
213 * Prolog mode is the default for ".pl" files.
214
215 * File names are not case-sensitive on VMS.
216
217 On VMS systems, all file names that you specify are converted to upper
218 case. You can use either upper or lower case indiscriminately.
219
220 * VMS-only function 'define-dcl-symbol'.
221
222 This is a new name for the function formerly called
223 `define-logical-name'.
224 \f
225 Editing Changes in Emacs 18
226
227 * Additional systems and machines are supported.
228
229 GNU Emacs now runs on Vax VMS. However, many facilities that are normally
230 implemented by running subprocesses do not work yet. This includes listing
231 a directory and sending mail. There are features for running subprocesses
232 but they are incompatible with those on Unix. I hope that some of
233 the VMS users can reimplement these features for VMS (compatibly for
234 the user, if possible).
235
236 VMS wizards are also asked to work on making the subprocess facilities
237 more upward compatible with those on Unix, and also to rewrite their
238 internals to use the same Lisp objects that are used on Unix to
239 represent processes.
240
241 In addition, the TI Nu machine running Unix system V, the AT&T 3b, and
242 the Wicat, Masscomp, Integrated Solutions, Alliant, Amdahl uts, Mips,
243 Altos 3068 and Gould Unix systems are now supported. The IBM PC-RT is
244 supported under 4.2, but not yet under system V. The GEC 93 is close
245 to working. The port for the Elxsi is partly merged. See the file
246 MACHINES for full status information and machine-specific installation
247 advice.
248
249 * Searching is faster.
250
251 Forward search for a text string, or for a regexp that is equivalent
252 to a text string, is now several times faster. Motion by lines and
253 counting lines is also faster.
254
255 * Memory usage improvements.
256
257 It is no longer possible to run out of memory during garbage
258 collection. As a result, running out of memory is never fatal. This
259 is due to a new garbage collection algorithm which compactifies
260 strings in place rather than copying them. Another consequence of the
261 change is a reduction in total memory usage and a slight increase in
262 garbage collection speed.
263
264 * Display changes.
265
266 ** Editing above top of screen.
267
268 When you delete or kill or alter text that reaches to the top of the
269 screen or above it, so that display would start in the middle of a
270 line, Emacs will usually attempt to scroll the text so that display
271 starts at the beginning of a line again.
272
273 ** Yanking in the minibuffer.
274
275 The message "Mark Set" is no longer printed when the minibuffer is
276 active. This is convenient with many commands, including C-y, that
277 normally print such a message.
278
279 ** Cursor appears in last line during y-or-n questions.
280
281 Questions that want a `y' or `n' answer now move the cursor
282 to the last line, following the question.
283
284 * Library loading changes.
285
286 `load' now considers all possible suffixes (`.elc', `.el' and none)
287 for each directory in `load-path' before going on to the next directory.
288 It now accepts an optional fourth argument which, if non-nil, says to
289 use no suffixes; then the file name must be given in full. The search
290 of the directories in `load-path' goes on as usual in this case, but
291 it too can be prevented by passing an absolute file name.
292
293 The value of `load-path' no longer by default includes nil (meaning to
294 look in the current default directory). The idea is that `load' should
295 be used to search the path only for libraries to be found in the standard
296 places. If you want to override system libraries with your own, place
297 your own libraries in one special directory and add that directory to the
298 front of `load-path'.
299
300 The function `load' is no longer a command; that is to say, `M-x load'
301 is no longer allowed. Instead, there are two commands for loading files.
302 `M-x load-library' is equivalent to the old meaning of `M-x load'.
303 `M-x load-file' reads a file name with completion and defaulting
304 and then loads exactly that file, with no searching and no suffixes.
305
306 * Emulation of other editors.
307
308 ** `edt-emulation-on' starts emulating DEC's EDT editor.
309
310 Do `edt-emulation-off' to return Emacs to normal.
311
312 ** `vi-mode' and `vip-mode' starts emulating vi.
313
314 These are two different vi emulations provided by GNU Emacs users.
315 We are interested in feedback as to which emulation is preferable.
316
317 See the documentation and source code for these functions
318 for more information.
319
320 ** `set-gosmacs-bindings' emulates Gosling Emacs.
321
322 This command changes many global bindings to resemble those of
323 Gosling Emacs. The previous bindings are saved and can be restored using
324 `set-gnu-bindings'.
325
326 * Emulation of a display terminal.
327
328 Within Emacs it is now possible to run programs (such as emacs or
329 supdup) which expect to do output to a visual display terminal.
330
331 See the function `terminal-emulator' for more information.
332
333 * New support for keypads and function keys.
334
335 There is now a first attempt at terminal-independent support for
336 keypad and function keys.
337
338 Emacs now defines a standard set of key-names for function and keypad
339 keys, and provides standard hooks for defining them. Most of the
340 standard key-names have default definitions built into Emacs; you can
341 override these in a terminal-independent manner. The default definitions
342 and the conventions for redefining them are in the file `lisp/keypad.el'.
343
344 These keys on the terminal normally work by sending sequences of
345 characters starting with ESC. The exact sequences used vary from
346 terminal to terminal. Emacs interprets them in two stages:
347 in the first stage, terminal-dependent sequences are mapped into
348 the standard key-names; then second stage maps the standard key-names
349 into their definitions in a terminal-independent fashion.
350
351 The terminal-specific file `term/$TERM.el' now is responsible only for
352 establishing the mapping from the terminal's escape sequences into
353 standard key-names. It no longer knows what Emacs commands are
354 assigned to the standard key-names.
355
356 One other change in terminal-specific files: if the value of the TERM
357 variable contains a hyphen, only the part before the first hyphen is
358 used in forming the name of the terminal-specific file. Thus, for
359 terminal type `aaa-48', the file loaded is now `term/aaa.el' rather
360 than `term/aaa-48.el'.
361
362 * New startup command line options.
363
364 `-i FILE' or `-insert FILE' in the command line to Emacs tells Emacs to
365 insert the contents of FILE into the current buffer at that point in
366 command line processing. This is like using the command M-x insert-file.
367
368 `-funcall', `-load', `-user' and `-no-init-file' are new synonyms for
369 `-f', `-l', `-u' and `-q'.
370
371 `-nw' means don't use a window system. If you are using a terminal
372 emulator on the X window system and you want to run Emacs to work through
373 the terminal emulator instead of working directly with the window system,
374 use this switch.
375
376 * Buffer-sorting commands.
377
378 Various M-x commands whose names start with `sort-' sort parts of
379 the region:
380
381 sort-lines divides the region into lines and sorts them alphabetically.
382 sort-pages divides into pages and sorts them alphabetically.
383 sort-paragraphs divides into paragraphs and sorts them alphabetically.
384 sort-fields divides into lines and sorts them alphabetically
385 according to one field in the line.
386 The numeric argument specifies which field (counting
387 from field 1 at the beginning of the line). Fields in a line
388 are separated by whitespace.
389 sort-numeric-fields
390 is similar but converts the specified fields to numbers
391 and sorts them numerically.
392 sort-columns divides into lines and sorts them according to the contents
393 of a specified range of columns.
394
395 Refer to the self-documentation of these commands for full usage information.
396
397 * Changes in various commands.
398
399 ** `tags-query-replace' and `tags-search' change.
400
401 These functions now display the name of the file being searched at the moment.
402
403 ** `occur' output now serves as a menu. `occur-menu' command deleted.
404
405 `M-x occur' now allows you to move quickly to any of the occurrences
406 listed. Select the `*Occur*' buffer that contains the output of `occur',
407 move point to the occurrence you want, and type C-c C-c.
408 This will move point to the same occurrence in the buffer that the
409 occurrences were found in.
410
411 The command `occur-menu' is thus obsolete, and has been deleted.
412
413 One way to get a list of matching lines without line numbers is to
414 copy the text to another buffer and use the command `keep-lines'.
415
416 ** Incremental search changes.
417
418 Ordinary and regexp incremental searches now have distinct default
419 search strings. Thus, regexp searches recall only previous regexp
420 searches.
421
422 If you exit an incremental search when the search string is empty,
423 the old default search string is kept. The default does not become
424 empty.
425
426 Reversing the direction of an incremental search with C-s or C-r
427 when the search string is empty now does not get the default search
428 string. It leaves the search string empty. A second C-s or C-r
429 will get the default search string. As a result, you can do a reverse
430 incremental regexp search with C-M-s C-r.
431
432 If you add a `*', `?' or `\|' to an incremental search regexp,
433 point will back up if that is appropriate. For example, if
434 you have searched for `ab' and add a `*', point moves to the
435 first match for `ab*', which may be before the match for `ab'
436 that was previously found.
437
438 If an incremental search is failing and you ask to repeat it,
439 it will start again from the beginning of the buffer (or the end,
440 if it is a backward search).
441
442 The search-controlling parameters `isearch-slow-speed' and
443 `isearch-slow-window-lines' have now been renamed to start with
444 `search' instead of `isearch'. Now all the parameters' names start
445 with `search'.
446
447 If `search-slow-window-lines' is negative, the slow search window
448 is put at the top of the screen, and the absolute value or the
449 negative number specifies the height of it.
450
451 ** Undo changes
452
453 The undo command now will mark the buffer as unmodified only when it is
454 identical to the contents of the visited file.
455
456 ** C-M-v in minibuffer.
457
458 If while in the minibuffer you request help in a way that uses a
459 window to display something, then until you exit the minibuffer C-M-v
460 in the minibuffer window scrolls the window of help.
461
462 For example, if you request a list of possible completions, C-M-v can
463 be used reliably to scroll the completion list.
464
465 ** M-TAB command.
466
467 Meta-TAB performs completion on the Emacs Lisp symbol names. The sexp
468 in the buffer before point is compared against all existing nontrivial
469 Lisp symbols and completed as far as is uniquely determined by them.
470 Nontrivial symbols are those with either function definitions, values
471 or properties.
472
473 If there are multiple possibilities for the very next character, a
474 list of possible completions is displayed.
475
476 ** Dynamic abbreviation package.
477
478 The new command Meta-/ expands an abbreviation in the buffer before point
479 by searching the buffer for words that start with the abbreviation.
480
481 ** Changes in saving kbd macros.
482
483 The commands `write-kbd-macro' and `append-kbd-macro' have been
484 deleted. The way to save a keyboard macro is to use the new command
485 `insert-kbd-macro', which inserts Lisp code to define the macro as
486 it is currently defined into the buffer before point. Visit a Lisp
487 file such as your Emacs init file `~/.emacs', insert the macro
488 definition (perhaps deleting an old definition for the same macro)
489 and then save the file.
490
491 ** C-x ' command.
492
493 The new command C-x ' (expand-abbrev) expands the word before point as
494 an abbrev, even if abbrev-mode is not turned on.
495
496 ** Sending to inferior Lisp.
497
498 The command C-M-x in Lisp mode, which sends the current defun to
499 an inferior Lisp process, now works by writing the text into a temporary
500 file and actually sending only a `load'-form to load the file.
501 As a result, it avoids the Unix bugs that used to strike when the
502 text was above a certain length.
503
504 With a prefix argument, this command now makes the inferior Lisp buffer
505 appear on the screen and scrolls it so that the bottom is showing.
506
507 Two variables `inferior-lisp-load-command' and `inferior-lisp-prompt',
508 exist to customize these feature for different Lisp implementations.
509
510 ** C-x p now disabled.
511
512 The command C-x p, a nonrecomended command which narrows to the current
513 page, is now initially disabled like C-x n.
514
515 * Dealing with files.
516
517 ** C-x C-v generalized
518
519 This command is now allowed even if the current buffer is not visiting
520 a file. As usual, it kills the current buffer and replaces it with a
521 newly found file.
522
523 ** M-x recover-file improved; auto save file names changed.
524
525 M-x recover-file now checks whether the last auto-save file is more
526 recent than the real visited file before offering to read in the
527 auto-save file. If the auto-save file is newer, a directory listing
528 containing the two files is displayed while you are asked whether you
529 want the auto save file.
530
531 Visiting a file also makes this check. If the auto-save file is more recent,
532 a message is printed suggesting that you consider using M-x recover file.
533
534 Auto save file names now by default have a `#' at the end as well
535 as at the beginning. This is so that `*.c' in a shell command
536 will never match auto save files.
537
538 On VMS, auto save file names are made by appending `_$' at the front
539 and `$' at the end.
540
541 When you change the visited file name of a buffer, the auto save file
542 is now renamed to belong to the new visited file name.
543
544 You can customize the way auto save file names are made by redefining
545 the two functions `make-auto-save-file-name' and `auto-save-file-name-p',
546 both of which are defined in `files.el'.
547
548 ** Modifying a buffer whose file is changed on disk is detected instantly.
549
550 On systems where clash detection (locking of files being edited) is
551 implemented, Emacs also checks the first time you modify a buffer
552 whether the file has changed on disk since it was last visited or saved.
553 If it has, you are asked to confirm that you want to change the buffer.
554
555 ** Exiting Emacs offers to save `*mail*'.
556
557 Emacs can now know about buffers that it should offer to save on exit
558 even though they are not visiting files. This is done for any buffer
559 which has a non-nil local value of `buffer-offer-save'. By default,
560 Mail mode provides such a local value.
561
562 ** Backup file changes.
563
564 If a backup file cannot be written in the directory of the visited file
565 due to fascist file protection, a backup file is now written in your home
566 directory as `~/%backup%~'. Only one such file is made, ever, so only
567 the most recently made such backup is available.
568
569 When backup files are made by copying, the last-modification time of the
570 original file is now preserved in the backup copy.
571
572 ** Visiting remote files.
573
574 On an internet host, you can now visit and save files on any other
575 internet host directly from Emacs with the commands M-x ftp-find-file
576 and M-x ftp-write-file. Specify an argument of the form HOST:FILENAME.
577 Since standard internet FTP is used, the other host may be any kind
578 of machine and is not required to have any special facilities.
579
580 The first time any one remote host is accessed, you will be asked to
581 give the user name and password for use on that host. FTP is reinvoked
582 each time you ask to use it, but previously specified user names and
583 passwords are remembered automatically.
584
585 ** Dired `g' command.
586
587 `g' in Dired mode is equivalent to M-x revert-buffer; it causes the
588 current contents of the same directory to be read in.
589
590 * Changes in major modes.
591
592 ** C mode indentation change.
593
594 The binding of Linefeed is no longer changed by C mode. It once again
595 has its normal meaning, which is to insert a newline and then indent
596 afterward.
597
598 The old definition did one additional thing: it reindented the line
599 before the new newline. This has been removed because it made the
600 command twice as slow. The only time it was really useful was after the
601 insertion of an `else', since the fact of starting with `else' may change
602 the way that line is indented. Now you will have to type TAB again
603 yourself to reindent the `else' properly.
604
605 If the variable `c-tab-always-indent' is set to `nil', the TAB command
606 in C mode, with no argument, will just insert a tab character if there
607 is non-whitespace preceding point on the current line. Giving it a
608 prefix argument will force reindentation of the line (as well as
609 of the compound statement that begins after point, if any).
610
611 ** Fortran mode now exists.
612
613 This mode provides commands for motion and indentation of Fortran code,
614 plus built-in abbrevs for Fortran keywords. For details, see the manual
615 or the on-line documentation of the command `fortran-mode'.
616
617 ** Scribe mode now exists.
618
619 This mode does something useful for editing files of Scribe input.
620 It is used automatically for files with names ending in ".mss".
621
622 ** Modula2 and Prolog modes now exist.
623
624 These modes are for editing programs in the languages of the same names.
625 They can be selected with M-x modula-2-mode and M-x prolog-mode.
626
627 ** Telnet mode changes.
628
629 The telnet mode special commands have now been assigned to C-c keys.
630 Most of them are the same as in Shell mode.
631
632 ** Picture mode changes.
633
634 The special picture-mode commands to specify the direction of cursor
635 motion after insertion have been moved to C-c keys. The commands to
636 specify diagonal motion were already C-c keys; they are unchanged.
637 The keys to specify horizontal or vertical motion are now
638 C-c < (left), C-c > (right), C-c ^ (up) and C-c . (down).
639
640 ** Nroff mode comments.
641
642 Comments are now supported in Nroff mode. The standard comment commands
643 such as M-; and C-x ; know how to insert, align and delete comments
644 that start with backslash-doublequote.
645
646 ** LaTeX mode.
647
648 LaTeX mode now exists. Use M-x latex-mode to select this mode, and
649 M-x plain-tex-mode to select the previously existing mode for Plain
650 TeX. M-x tex-mode attempts to examine the contents of the buffer and
651 choose between latex-mode and plain-tex-mode accordingly; if the
652 buffer is empty or it cannot tell, the variable `TeX-default-mode'
653 controls the choice. Its value should be the symbol for the mode to
654 be used.
655
656 The facilities for running TeX on all or part of the buffer
657 work with LaTeX as well.
658
659 Some new commands available in both modes:
660
661 C-c C-l recenter the window showing the TeX output buffer
662 so most recent line of output can be seen.
663 C-c C-k kill the TeX subprocess.
664 C-c C-q show the printer queue.
665 C-c C-f close a block (appropriate for LaTeX only).
666 If the current line contains a \begin{...},
667 this inserts an \end{...} on the following line
668 and puts point on a blank line between them.
669
670 ** Outline mode changes.
671
672 Invisible lines in outline mode are now indicated by `...' at the
673 end of the previous visible line.
674
675 The special outline heading motion commands are now all on C-c keys.
676 A few new ones have been added. Here is a full list:
677
678 C-c C-n Move to next visible heading (formerly M-})
679 C-c C-p Move to previous visible heading (formerly M-{)
680 C-c C-f Move to next visible heading at the same level.
681 Thus, if point is on a level-2 heading line,
682 this command moves to the next visible level-2 heading.
683 C-c C-b Move to previous visible heading at the same level.
684 C-c C-u Move up to previous visible heading at a higher level.
685
686 The variable `outline-regexp' now controls recognition of heading lines.
687 Any line whose beginning matches this regexp is a heading line.
688 The depth in outline structure is determined by the length of
689 the string that matches.
690
691 A line starting with a ^L (formfeed) is now by default considered
692 a header line.
693
694 * Mail reading and sending.
695
696 ** MH-E changes.
697
698 MH-E has been extensively modified and improved since the v17 release.
699 It contains many new features, including commands to: extracted failed
700 messages, kill a draft message, undo changes to a mail folder, monitor
701 delivery of a letter, print multiple messages, page digests backwards,
702 insert signatures, and burst digests. Also, many commands have been
703 made to able to deal with named sequences of messages, instead of
704 single messages. MH-E also has had numerous bugs fixed and commands
705 made to run faster. Furthermore, its keybindings have been changed to
706 be compatible with Rmail and the rest of GNU Emacs.
707
708 ** Mail mode changes.
709
710 The C-c commands of mail mode have been rearranged:
711
712 C-c s, C-c c, C-c t and C-c b (move point to various header fields)
713 have been reassigned as C-c C-f C-s, C-c C-f C-c, C-c C-f C-t and C-c
714 C-f C-b. C-c C-f is for "field".
715
716 C-c y, C-c w and C-c q have been changed to C-c C-y, C-c C-w and C-c C-q.
717
718 Thus, C-c LETTER is always unassigned.
719
720 ** Rmail C-r command changed to w.
721
722 The Rmail command to edit the current message is now `w'. This change
723 has been made because people frequently type C-r while in Rmail hoping
724 to do a reverse incremental search. That now works.
725
726 * Rnews changes.
727
728 ** Caesar rotation added.
729
730 The function news-caesar-buffer-body performs encryption and
731 decryption of the body of a news message. It defaults to the USENET
732 standard of 13, and accepts any numeric arg between 1 to 25 and -25 to -1.
733 The function is bound to C-c C-r in both news-mode and news-reply-mode.
734
735 ** rmail-output command added.
736
737 The C-o command has been bound to rmail-output in news-mode.
738 This allows one to append an article to a file which is in either Unix
739 mail or RMAIL format.
740
741 ** news-reply-mode changes.
742
743 The C-c commands of news reply mode have been rearranged and changed,
744 so that C-c LETTER is always unassigned:
745
746 C-c y, C-c w and C-c q have been changed to C-c C-y, C-c C-w and C-c C-q.
747
748 C-c c, C-c t, and C-c b (move to various mail header fields) have been
749 deleted (they make no sense for posting and replying to USENET).
750
751 C-c s (move to Subject: header field) has been reassigned as C-c C-f
752 C-s. C-c C-f is for "field". Several additional move to news header
753 field commands have been added.
754
755 The local news-reply-mode bindings now look like this:
756
757 C-c C-s news-inews (post the message) C-c C-c news-inews
758 C-c C-f move to a header field (and create it if there isn't):
759 C-c C-f C-n move to Newsgroups: C-c C-f C-s move to Subj:
760 C-c C-f C-f move to Followup-To: C-c C-f C-k move to Keywords:
761 C-c C-f C-d move to Distribution: C-c C-f C-a move to Summary:
762 C-c C-y news-reply-yank-original (insert current message, in NEWS).
763 C-c C-q mail-fill-yanked-message (fill what was yanked).
764 C-c C-r caesar rotate all letters by 13 places in the article's body (rot13).
765
766 * Existing Emacs usable as a server.
767
768 Programs such as mailers that invoke "the editor" as an inferior
769 to edit some text can now be told to use an existing Emacs process
770 instead of creating a new editor.
771
772 To do this, you must have an Emacs process running and capable of
773 doing terminal I/O at the time you want to invoke it. This means that
774 either you are using a window system and give Emacs a separate window
775 or you run the other programs as inferiors of Emacs (such as, using
776 M-x shell).
777
778 First prepare the existing Emacs process by loading the `server'
779 library and executing M-x server-start. (Your .emacs can do this
780 automatically.)
781
782 Now tell the other programs to use, as "the editor", the Emacs client
783 program (etc/emacsclient, located in the same directory as this file).
784 This can be done by setting the environment variable EDITOR.
785
786 When another program invokes the emacsclient as "the editor", the
787 client actually transfers the file names to be edited to the existing
788 Emacs, which automatically visits the files.
789
790 When you are done editing a buffer for a client, do C-x # (server-edit).
791 This marks that buffer as done, and selects the next buffer that the client
792 asked for. When all the buffers requested by a client are marked in this
793 way, Emacs tells the client program to exit, so that the program that
794 invoked "the editor" will resume execution.
795
796 You can only have one server Emacs at a time, but multiple client programs
797 can put in requests at the same time.
798
799 The client/server work only on Berkeley Unix, since they use the Berkeley
800 sockets mechanism for their communication.
801 \f
802 Changes in Lisp programming in Emacs version 18.
803
804 * Init file changes.
805
806 ** Suffixes no longer accepted on `.emacs'.
807
808 Emacs will no longer load a file named `.emacs.el' or `emacs.elc'
809 in place of `.emacs'. This is so that it will take less time to
810 find `.emacs'. If you want to compile your init file, give it another
811 name and make `.emacs' a link to the `.elc' file, or make it contain
812 a call to `load' to load the `.elc' file.
813
814 ** `default-profile' renamed to `default', and loaded after `.emacs'.
815
816 It used to be the case that the file `default-profile' was loaded if
817 and only if `.emacs' was not found.
818
819 Now the name `default-profile' is not used at all. Instead, a library
820 named `default' is loaded after the `.emacs' file. `default' is loaded
821 whether the `.emacs' file exists or not. However, loading of `default'
822 can be prevented if the `.emacs' file sets `inhibit-default-init' to non-nil.
823
824 In fact, you would call the default file `default.el' and probably would
825 byte-compile it to speed execution.
826
827 Note that for most purposes you are better off using a `site-init' library
828 since that will be loaded before the runnable Emacs is dumped. By using
829 a `site-init' library, you avoid taking up time each time Emacs is started.
830
831 ** inhibit-command-line has been eliminated.
832
833 This variable used to exist for .emacs files to set. It has been
834 eliminated because you can get the same effect by setting
835 command-line-args to nil and setting inhibit-startup-message to t.
836
837 * `apply' is more general.
838
839 `apply' now accepts any number of arguments. The first one is a function;
840 the rest are individual arguments to pass to that function, except for the
841 last, which is a list of arguments to pass.
842
843 Previously, `apply' required exactly two arguments. Its old behavior
844 follows as a special case of the new definition.
845
846 * New code-letter for `interactive'.
847
848 (interactive "NFoo: ") is like (interactive "nFoo: ") in reading
849 a number using the minibuffer to serve as the argument; however,
850 if a prefix argument was specified, it uses the prefix argument
851 value as the argument, and does not use the minibuffer at all.
852
853 This is used by the `goto-line' and `goto-char' commands.
854
855 * Semantics of variables.
856
857 ** Built-in per-buffer variables improved.
858
859 Several built-in variables which in the past had a different value in
860 each buffer now behave exactly as if `make-variable-buffer-local' had
861 been done to them.
862
863 These variables are `tab-width', `ctl-arrow', `truncate-lines',
864 `fill-column', `left-margin', `mode-line-format', `abbrev-mode',
865 `overwrite-mode', `case-fold-search', `auto-fill-hook',
866 `selective-display', `selective-display-ellipses'.
867
868 To be precise, each variable has a default value which shows through
869 in most buffers and can be accessed with `default-value' and set with
870 `set-default'. Setting the variable with `setq' makes the variable
871 local to the current buffer. Changing the default value has retroactive
872 effect on all buffers in which the variable is not local.
873
874 The variables `default-case-fold-search', etc., are now obsolete.
875 They now refer to the default value of the variable, which is not
876 quite the same behavior as before, but it should enable old init files
877 to continue to work.
878
879 ** New per-buffer variables.
880
881 The variables `fill-prefix', `comment-column' and `indent-tabs-mode'
882 are now per-buffer. They work just like `fill-column', etc.
883
884 ** New function `setq-default'.
885
886 `setq-default' sets the default value of a variable, and uses the
887 same syntax that `setq' accepts: the variable name is not evaluated
888 and need not be quoted.
889
890 `(setq-default case-fold-search nil)' would make searches case-sensitive
891 in all buffers that do not have local values for `case-fold-search'.
892
893 ** Functions `global-set' and `global-value' deleted.
894
895 These functions were never used except by mistake by users expecting
896 the functionality of `set-default' and `default-value'.
897
898 * Changes in defaulting of major modes.
899
900 When `default-major-mode' is `nil', new buffers are supposed to
901 get their major mode from the buffer that is current. However,
902 certain major modes (such as Dired mode, Rmail mode, Rmail Summary mode,
903 and others) are not reasonable to use in this way.
904
905 Now such modes' names have been given non-`nil' `mode-class' properties.
906 If the current buffer's mode has such a property, Fundamental mode is
907 used as the default for newly created buffers.
908
909 * `where-is-internal' requires additional arguments.
910
911 This function now accepts three arguments, two of them required:
912 DEFINITION, the definition to search for; LOCAL-KEYMAP, the keymap
913 to use as the local map when doing the searching, and FIRST-ONLY,
914 which is nonzero to return only the first key found.
915
916 This function returns a list of keys (strings) whose definitions
917 (in the LOCAL-KEYMAP or the current global map) are DEFINITION.
918
919 If FIRST-ONLY is non-nil, it returns a single key (string).
920
921 This function has changed incompatibly in that now two arguments
922 are required when previously only one argument was allowed. To get
923 the old behavior of this function, write `(current-local-map)' as
924 the expression for the second argument.
925
926 The incompatibility is sad, but `nil' is a legitimate value for the
927 second argument (it means there is no local keymap), so it cannot also
928 serve as a default meaning to use the current local keymap.
929
930 * Abbrevs with hooks.
931
932 When an abbrev defined with a hook is expanded, it now performs the
933 usual replacement of the abbrev with the expansion before running the
934 hook. Previously the abbrev itself was deleted but the expansion was
935 not inserted.
936
937 * Function `scan-buffer' deleted.
938
939 Use `search-forward' or `search-backward' in place of `scan-buffer'.
940 You will have to rearrange the arguments.
941
942 * X window interface improvements.
943
944 ** Detect release of mouse buttons.
945
946 Button-up events can now be detected. See the file `lisp/x-mouse.el'
947 for details.
948
949 ** New pop-up menu facility.
950
951 The new function `x-popup-menu' pops up a menu (in a X window)
952 and returns an indication of which selection the user made.
953 For more information, see its self-documentation.
954
955 * M-x disassemble.
956
957 This command prints the disassembly of a byte-compiled Emacs Lisp function.
958
959 Would anyone like to interface this to the debugger?
960
961 * `insert-buffer-substring' can insert part of the current buffer.
962
963 The old restriction that the text being inserted had to come from
964 a different buffer is now lifted.
965
966 When inserting text from the current buffer, the text to be inserted
967 is determined from the specified bounds before any copying takes place.
968
969 * New function `substitute-key-definition'.
970
971 This is a new way to replace one command with another command as the
972 binding of whatever keys may happen to refer to it.
973
974 (substitute-key-definition OLDDEF NEWDEF KEYMAP) looks through KEYMAP
975 for keys defined to run OLDDEF, and rebinds those keys to run NEWDEF
976 instead.
977
978 * New function `insert-char'.
979
980 Insert a specified character, a specified number of times.
981
982 * `mark-marker' changed.
983
984 When there is no mark, this now returns a marker that points
985 nowhere, rather than `nil'.
986
987 * `ding' accepts argument.
988
989 When given an argument, the function `ding' does not terminate
990 execution of a keyboard macro. Normally, `ding' does terminate
991 all macros that are currently executing.
992
993 * New function `minibuffer-depth'.
994
995 This function returns the current depth in minibuffer activations.
996 The value is zero when the minibuffer is not in use.
997 Values greater than one are possible if the user has entered the
998 minibuffer recursively.
999
1000 * New function `documentation-property'.
1001
1002 (documentation-property SYMBOL PROPNAME) is like (get SYMBOL PROPNAME),
1003 except that if the property value is a number `documentation-property'
1004 will take that number (or its absolute value) as a character position
1005 in the DOC file and return the string found there.
1006
1007 (documentation-property VAR 'variable-documentation) is the proper
1008 way for a Lisp program to get the documentation of variable VAR.
1009
1010 * New documentation-string expansion feature.
1011
1012 If a documentation string (for a variable or function) contains text
1013 of the form `\<FOO>', it means that all command names specified in
1014 `\[COMMAND]' construct from that point on should be turned into keys
1015 using the value of the variable FOO as the local keymap. Thus, for example,
1016
1017 `\<emacs-lisp-mode-map>\[eval-defun] evaluates the defun containing point.'
1018
1019 will expand into
1020
1021 "ESC C-x evaluates the defun containing point."
1022
1023 regardless of the current major mode, because ESC C-x is defined to
1024 run `eval-defun' in the keymap `emacs-lisp-mode-map'. The effect is
1025 to show the key for `eval-defun' in Emacs Lisp mode regardless of the
1026 current major mode.
1027
1028 The `\<...>' construct applies to all `\[...]' constructs that follow it,
1029 up to the end of the documentation string or the next `\<...>'.
1030
1031 Without `\<...>', the keys for commands specified in `\[...]' are found
1032 in the current buffer's local map.
1033
1034 The current global keymap is always searched second, whether `\<...>'
1035 has been used or not.
1036
1037 * Multiple hooks allowed in certain contexts.
1038
1039 The old hook variables `find-file-hook', `find-file-not-found-hook' and
1040 `write-file-hook' have been replaced.
1041
1042 The replacements are `find-file-hooks', `find-file-not-found-hooks'
1043 and `write-file-hooks'. Each holds a list of functions to be called;
1044 by default, `nil', for no functions. The functions are called in
1045 order of appearance in the list.
1046
1047 In the case of `find-file-hooks', all the functions are executed.
1048
1049 In the case of `find-file-not-found-hooks', if any of the functions
1050 returns non-`nil', the rest of the functions are not called.
1051
1052 In the case of `write-file-hooks', if any of the functions returns
1053 non-`nil', the rest of the functions are not called, and the file is
1054 considered to have been written already; so actual writing in the
1055 usual way is not done. If `write-file-hooks' is local to a buffer,
1056 it is set to its global value if `set-visited-file-name' is called
1057 (and thus by C-x C-w as well).
1058
1059 `find-file-not-found-hooks' and `write-file-hooks' can be used
1060 together to implement editing of files that are not stored as Unix
1061 files: stored in archives, or inside version control systems, or on
1062 other machines running other operating systems and accessible via ftp.
1063
1064 * New hooks for suspending Emacs.
1065
1066 Suspending Emacs runs the hook `suspend-hook' before suspending
1067 and the hook `suspend-resume-hook' if the suspended Emacs is resumed.
1068 Running a hook is done by applying the variable's value to no arguments
1069 if the variable has a non-`nil' value. If `suspend-hook' returns
1070 non-`nil', then suspending is inhibited and so is running the
1071 `suspend-resume-hook'. The non-`nil' value means that the `suspend-hook'
1072 has done whatever suspending is required.
1073
1074 * Disabling commands can print a special message.
1075
1076 A command is disabled by giving it a non-`nil' `disabled' property.
1077 Now, if this property is a string, it is included in the message
1078 printed when the user tries to run the command.
1079
1080 * Emacs can open TCP connections.
1081
1082 The function `open-network-stream' opens a TCP connection to
1083 a specified host and service. Its value is a Lisp object that represents
1084 the connection. The object is a kind of "subprocess", and I/O are
1085 done like I/O to subprocesses.
1086
1087 * Display-related changes.
1088
1089 ** New mode-line control features.
1090
1091 The display of the mode line used to be controlled by a format-string
1092 that was the value of the variable `mode-line-format'.
1093
1094 This variable still exists, but it now allows more general values,
1095 not just strings. Lists, cons cells and symbols are also meaningful.
1096
1097 The mode line contents are created by outputting various mode elements
1098 one after the other. Here are the kinds of objects that can be
1099 used as mode elements, and what they do in the display:
1100
1101 string the contents of the string are output to the mode line,
1102 and %-constructs are replaced by other text.
1103
1104 t or nil ignored; no output results.
1105
1106 symbol the symbol's value is used. If the value is a string,
1107 the string is output verbatim to the mode line
1108 (so %-constructs are not interpreted). Otherwise,
1109 the symbol's value is processed as a mode element.
1110
1111 list (whose first element is a string or list or cons cell)
1112 the elements of the list are treated as as mode elements,
1113 so that the output they generate is concatenated,
1114
1115 list (whose car is a symbol)
1116 if the symbol's value is non-nil, the second element of the
1117 list is treated as a mode element. Otherwise, the third
1118 element (if any) of the list is treated as a mode element.
1119
1120 cons (whose car is a positive integer)
1121 the cdr of the cons is used as a mode element, but
1122 the text it produces is padded, if necessary, to have
1123 at least the width specified by the integer.
1124
1125 cons (whose car is a negative integer)
1126 the cdr of the cons is used as a mode element, but
1127 the text it produces is truncated, if necessary, to have
1128 at most the width specified by the integer.
1129
1130 There is always one mode element to start with, that being the value of
1131 `mode-line-format', but if this value is a list then it leads to several
1132 more mode elements, which can lead to more, and so on.
1133
1134 There is one new %-construct for mode elements that are strings:
1135 `%n' displays ` Narrow' for a buffer that is narrowed.
1136
1137 The default value of `mode-line-format' refers to several other variables.
1138 These variables are `mode-name', `mode-line-buffer-identification',
1139 `mode-line-process', `mode-line-modified', `global-mode-string' and
1140 `minor-mode-alist'. The first four are local in every buffer in which they
1141 are changed from the default.
1142
1143 mode-name Name of buffer's major mode. Local in every buffer.
1144
1145 mode-line-buffer-identification
1146 Normally the list ("Emacs: %17b"), it is responsible
1147 for displaying text to indicate what buffer is being shown
1148 and what kind of editing it is doing. `Emacs' means
1149 that a file of characters is being edited. Major modes
1150 such as Info and Dired which edit or view other kinds
1151 of data often change this value. This variables becomes
1152 local to the current buffer if it is setq'd.
1153
1154 mode-line-process
1155 Normally nil, this variable is responsible for displaying
1156 information about the process running in the current buffer.
1157 M-x shell-mode and M-x compile alter this variable.
1158
1159 mode-line-modified
1160 This variable is responsible for displaying the indication
1161 of whether the current buffer is modified or read-only.
1162 By default its value is `("--%*%*-")'.
1163
1164 minor-mode-alist
1165 This variable is responsible for displaying text for those
1166 minor modes that are currently enabled. Its value
1167 is a list of elements of the form (VARIABLE STRING),
1168 where STRING is to be displayed if VARIABLE's value
1169 (in the buffer whose mode line is being displayed)
1170 is non-nil. This variable is not made local to particular
1171 buffers, but loading some libraries may add elements to it.
1172
1173 global-mode-string
1174 This variable is used to display the time, if you ask
1175 for that.
1176
1177 The idea of these variables is to eliminate the need for major modes
1178 to alter mode-line-format itself.
1179
1180 ** `window-point' valid for selected window.
1181
1182 The value returned by `window-point' used to be incorrect when its
1183 argument was the selected window. Now the value is correct.
1184
1185 ** Window configurations may be saved as Lisp objects.
1186
1187 The function `current-window-configuration' returns a special type of
1188 Lisp object that represents the current layout of windows: the
1189 sizes and positions of windows, which buffers appear in them, and
1190 which parts of the buffers appear on the screen.
1191
1192 The function `set-window-configuration' takes one argument, which must
1193 be a window configuration object, and restores that configuration.
1194
1195 ** New hook `temp-output-buffer-show-hook'.
1196
1197 This hook allows you to control how help buffers are displayed.
1198 Whenever `with-output-to-temp-buffer' has executed its body and wants
1199 to display the temp buffer, if this variable is bound and non-`nil'
1200 then its value is called with one argument, the temp buffer.
1201 The hook function is solely responsible for displaying the buffer.
1202 The standard manner of display--making the buffer appear in a window--is
1203 used only if there is no hook function.
1204
1205 ** New function `minibuffer-window'.
1206
1207 This function returns the window used (sometimes) for displaying
1208 the minibuffer. It can be used even when the minibuffer is not active.
1209
1210 ** New feature to `next-window'.
1211
1212 If the optional second argument is neither `nil' nor `t', the minibuffer
1213 window is omitted from consideration even when active; if the starting
1214 window was the last non-minibuffer window, the value will be the first
1215 non-minibuffer window.
1216
1217 ** New variable `minibuffer-scroll-window'.
1218
1219 When this variable is non-`nil', the command `scroll-other-window'
1220 uses it as the window to be scrolled. Displays of completion-lists
1221 set this variable to the window containing the display.
1222
1223 ** New argument to `sit-for'.
1224
1225 A non-nil second argument to `sit-for' means do not redisplay;
1226 just wait for the specified time or until input is available.
1227
1228 ** Deleted function `set-minor-mode'; minor modes must be changed.
1229
1230 The function `set-minor-mode' has been eliminated. The display
1231 of minor mode names in the mode line is now controlled by the
1232 variable `minor-mode-alist'. To specify display of a new minor
1233 mode, it is sufficient to add an element to this list. Once that
1234 is done, you can turn the mode on and off just by setting a variable,
1235 and the display will show its status automatically.
1236
1237 ** New variable `cursor-in-echo-area'.
1238
1239 If this variable is non-nil, the screen cursor appears on the
1240 last line of the screen, at the end of the text displayed there.
1241
1242 Binding this variable to t is useful at times when reading single
1243 characters of input with `read-char'.
1244
1245 ** New per-buffer variable `selective-display-ellipses'.
1246
1247 If this variable is non-nil, an ellipsis (`...') appears on the screen
1248 at the end of each text line that is followed by invisible text.
1249
1250 If this variable is nil, no ellipses appear. Then there is no sign
1251 on the screen that invisible text is present.
1252
1253 Text is made invisible under the control of the variable
1254 `selective-display'; this is how Outline mode and C-x $ work.
1255
1256 ** New variable `no-redraw-on-reenter'.
1257
1258 If you set this variable non-nil, Emacs will not clear the screen when
1259 you resume it after suspending it. This is for the sake of terminals
1260 with multiple screens of memory, where the termcap entry has been set
1261 up to switch between screens when Emacs is suspended and resumed.
1262
1263 ** New argument to `set-screen-height' or `set-screen-width'.
1264
1265 These functions now take an optional second argument which says
1266 what significance the newly specified height or width has.
1267
1268 If the argument is nil, or absent, it means that Emacs should
1269 believe that the terminal height or width really is as just specified.
1270
1271 If the argument is t, it means Emacs should not believe that the
1272 terminal really is this high or wide, but it should use the
1273 specific height or width as the number of lines or columns to display.
1274 Thus, you could display only 24 lines on a screen known to have 48 lines.
1275
1276 What practical difference is there between using only 24 lines for display
1277 and really believing that the terminal has 24 lines?
1278
1279 1. The ``real'' height of the terminal says what the terminal command
1280 to move the cursor to the last line will do.
1281
1282 2. The ``real'' height of the terminal determines how much padding is
1283 needed.
1284
1285 * File-related changes.
1286
1287 ** New parameter `backup-by-copying-when-mismatch'.
1288
1289 If this variable is non-`nil', then when Emacs is about to save a
1290 file, it will create the backup file by copying if that would avoid
1291 changing the file's uid or gid.
1292
1293 The default value of this variable is `nil', because usually it is
1294 useful to have the uid of a file change according to who edited it
1295 last. I recommend thet this variable be left normally `nil' and
1296 changed with a local variables list in those particular files where
1297 the uid needs to be preserved.
1298
1299 ** New parameter `file-precious-flag'.
1300
1301 If this variable is non-`nil', saving the buffer tries to avoid
1302 leaving an incomplete file due to disk full or other I/O errors.
1303 It renames the old file before saving. If saving is successful,
1304 the renamed file is deleted; if saving gets an error, the renamed
1305 file is renamed back to the name you visited.
1306
1307 Backups are always made by copying for such files.
1308
1309 ** New variable `buffer-offer-save'.
1310
1311 If the value of this variable is non-`nil' in a buffer then exiting
1312 Emacs will offer to save the buffer (if it is modified and nonempty)
1313 even if the buffer is not visiting a file. This variable is
1314 automatically made local to the current buffer whenever it is set.
1315
1316 ** `rename-file', `copy-file', `add-name-to-file' and `make-symbolic-link'.
1317
1318 The third argument to these functions used to be `t' or `nil'; `t'
1319 meaning go ahead even if the specified new file name already has a file,
1320 and `nil' meaning to get an error.
1321
1322 Now if the third argument is a number it means to ask the user for
1323 confirmation in this case.
1324
1325 ** New optional argument to `copy-file'.
1326
1327 If `copy-file' receives a non-nil fourth argument, it attempts
1328 to give the new copy the same time-of-last-modification that the
1329 original file has.
1330
1331 ** New function `file-newer-than-file-p'.
1332
1333 (file-newer-than-file-p FILE1 FILE2) returns non-nil if FILE1 has been
1334 modified more recently than FILE2. If FILE1 does not exist, the value
1335 is always nil; otherwise, if FILE2 does not exist, the value is t.
1336 This is meant for use when FILE2 depends on FILE1, to see if changes
1337 in FILE1 make it necessary to recompute FILE2 from it.
1338
1339 ** Changed function `file-exists-p'.
1340
1341 This function is no longer the same as `file-readable-p'.
1342 `file-exists-p' can now return t for a file that exists but which
1343 the fascists won't allow you to read.
1344
1345 ** New function `file-locked-p'.
1346
1347 This function receives a file name as argument and returns `nil'
1348 if the file is not locked, `t' if locked by this Emacs, or a
1349 string giving the name of the user who has locked it.
1350
1351 ** New function `file-name-sans-versions'.
1352
1353 (file-name-sans-versions NAME) returns a substring of NAME, with any
1354 version numbers or other backup suffixes deleted from the end.
1355
1356 ** New functions for directory names.
1357
1358 Although a directory is really a kind of file, specifying a directory
1359 uses a somewhat different syntax from specifying a file.
1360 In Emacs, a directory name is used as part of a file name.
1361
1362 On Unix, the difference is small: a directory name ends in a slash,
1363 while a file name does not: thus, `/usr/rms/' to name a directory,
1364 while `/usr/rms' names the file which holds that directory.
1365
1366 On VMS, the difference is considerable: `du:[rms.foo]' specifies a
1367 directory, but the name of the file that holds that directory is
1368 `du:[rms]foo.dir'.
1369
1370 There are two new functions for converting between directory names
1371 and file names. `directory-file-name' takes a directory name and
1372 returns the name of the file in which that directory's data is stored.
1373 `file-name-as-directory' takes the name of a file and returns
1374 the corresponding directory name. These always understand Unix file name
1375 syntax; on VMS, they understand VMS syntax as well.
1376
1377 For example, (file-name-as-directory "/usr/rms") returns "/usr/rms/"
1378 and (directory-file-name "/usr/rms/") returns "/usr/rms".
1379 On VMS, (file-name-as-directory "du:[rms]foo.dir") returns "du:[rms.foo]"
1380 and (directory-file-name "du:[rms.foo]") returns "du:[rms]foo.dir".
1381
1382 ** Value of `file-attributes' changed.
1383
1384 The function file-attributes returns a list containing many kinds of
1385 information about a file. Now the list has eleven elements.
1386
1387 The tenth element is `t' if deleting the file and creating another
1388 file of the same name would result in a change in the file's group;
1389 `nil' if there would be no change. You can also think of this as
1390 comparing the file's group with the default group for files created in
1391 the same directory by you.
1392
1393 The eleventh element is the inode number of the file.
1394
1395 ** VMS-only function `file-name-all-versions'.
1396
1397 This function returns a list of all the completions, including version
1398 number, of a specified version-number-less file name. This is like
1399 `file-name-all-completions', except that the latter returns values
1400 that do not include version numbers.
1401
1402 ** VMS-only variable `vms-stmlf-recfm'.
1403
1404 On a VMS system, if this variable is non-nil, Emacs will give newly
1405 created files the record format `stmlf'. This is necessary for files
1406 that must contain lines of arbitrary length, such as compiled Emacs
1407 Lisp.
1408
1409 When writing a new version of an existing file, Emacs always keeps
1410 the same record format as the previous version; so this variable has
1411 no effect.
1412
1413 This variable has no effect on Unix systems.
1414
1415 ** `insert-file-contents' on an empty file.
1416
1417 This no longer sets the buffer's "modified" flag.
1418
1419 ** New function (VMS only) `define-logical-name':
1420
1421 (define-logical-name LOGICAL TRANSLATION) defines a VMS logical name
1422 LOGICAL whose translation is TRANSLATION. The new name applies to
1423 the current process only.
1424
1425 ** Deleted variable `ask-about-buffer-names'.
1426
1427 If you want buffer names for files to be generated in a special way,
1428 you must redefine `create-file-buffer'.
1429
1430 * Subprocess-related changes.
1431
1432 ** New function `process-list'.
1433
1434 This function takes no arguments and returns a list of all
1435 of Emacs's asynchronous subprocesses.
1436
1437 ** New function `process-exit-status'.
1438
1439 This function, given a process, process name or buffer as argument,
1440 returns the exit status code or signal number of the process.
1441 If the process has not yet exited or died, this function returns 0.
1442
1443 ** Process output ignores `buffer-read-only'.
1444
1445 Output from a process will go into the process's buffer even if the
1446 buffer is read only.
1447
1448 ** Switching buffers in filter functions and sentinels.
1449
1450 Emacs no longer saves and restore the current buffer around calling
1451 the filter and sentinel functions, so these functions can now
1452 permanently alter the selected buffer in a straightforward manner.
1453
1454 ** Specifying environment variables for subprocesses.
1455
1456 When a subprocess is started with `start-process' or `call-process',
1457 the value of the variable `process-environment' is taken to
1458 specify the environment variables to give the subprocess. The
1459 value should be a list of strings, each of the form "VAR=VALUE".
1460
1461 `process-environment' is initialized when Emacs starts up
1462 based on Emacs's environment.
1463
1464 ** New variable `process-connection-type'.
1465
1466 If this variable is `nil', when a subprocess is created, Emacs uses
1467 a pipe rather than a pty to communicate with it. Normally this
1468 variable is `t', telling Emacs to use a pty if ptys are supported
1469 and one is available.
1470
1471 ** New function `waiting-for-user-input-p'.
1472
1473 This function, given a subprocess as argument, returns `t' if that
1474 subprocess appears to be waiting for input sent from Emacs,
1475 or `nil' otherwise.
1476
1477 ** New hook `shell-set-directory-error-hook'.
1478
1479 The value of this variable is called, with no arguments, whenever
1480 Shell mode gets an error trying to keep track of directory-setting
1481 commands (such as `cd' and `pushd') used in the shell buffer.
1482
1483 * New functions `user-uid' and `user-real-uid'.
1484
1485 These functions take no arguments and return, respectively,
1486 the effective uid and the real uid of the Emacs process.
1487 The value in each case is an integer.
1488
1489 * New variable `print-escape-newlines' controls string printing.
1490
1491 If this variable is non-`nil', then when a Lisp string is printed
1492 by the Lisp printing function `prin1' or `print', newline characters
1493 are printed as `\n' rather than as a literal newline.
1494
1495 * New function `sysnetunam' on HPUX.
1496
1497 This function takes two arguments, a network address PATH and a
1498 login string LOGIN, and executes the system call `netunam'.
1499 It returns `t' if the call succeeds, otherwise `nil'.
1500 \f
1501 News regarding installation:
1502
1503 * Many `s-...' file names changed.
1504
1505 Many `s-...' files have been renamed. All periods in such names,
1506 except the ones just before the final `h', have been changed to
1507 hyphens. Thus, `s-bsd4.2.h' has been renamed to `s-bsd4-2.h'.
1508
1509 This is so a Unix distribution can be moved mechanically to VMS.
1510
1511 * `DOCSTR...' file now called `DOC-...'.
1512
1513 The file of on-line documentation strings, that used to be
1514 `DOCSTR.mm.nn.oo' in this directory, is now called `DOC-mm.nn.oo'.
1515 This is so that it can port to VMS using the standard conventions
1516 for translating filenames for VMS.
1517
1518 This file also now contains the doc strings for variables as
1519 well as functions.
1520
1521 * Emacs no longer uses floating point arithmetic.
1522
1523 This may make it easier to port to some machines.
1524
1525 * Macros `XPNTR' and `XSETPNTR'; flag `DATA_SEG_BITS'.
1526
1527 These macros exclusively are used to unpack a pointer from a Lisp_Object
1528 and to insert a pointer into a Lisp_Object. Redefining them may help
1529 port Emacs to machines in which all pointers to data objects have
1530 certain high bits set.
1531
1532 If `DATA_SEG_BITS' is defined, it should be a number which contains
1533 the high bits to be inclusive or'ed with pointers that are unpacked.
1534
1535 * New flag `HAVE_X_MENU'.
1536
1537 Define this flag in `config.h' in addition to `HAVE_X_WINDOWS'
1538 to enable use of the Emacs interface to X Menus. On some operating
1539 systems, the rest of the X interface works properly but X Menus
1540 do not work; hence this separate flag. See the file `src/xmenu.c'
1541 for more information.
1542
1543 * Macros `ARRAY_MARK_FLAG' and `DONT_COPY_FLAG'.
1544
1545 * `HAVE_ALLOCA' prevents assembly of `alloca.s'.
1546
1547 * `SYSTEM_MALLOC' prevents use of GNU `malloc.c'.
1548
1549 SYSTEM_MALLOC, if defined, means use the system's own `malloc' routines
1550 rather than those that come with Emacs.
1551
1552 Use this only if absolutely necessary, because if it is used you do
1553 not get warnings when space is getting low.
1554
1555 * New flags to control unexec.
1556
1557 See the file `unexec.c' for a long comment on the compilation
1558 switches that suffice to make it work on many machines.
1559
1560 * `PNTR_COMPARISON_TYPE'
1561
1562 Pointers that need to be compared for ordering are converted to this type
1563 first. Normally this is `unsigned int'.
1564
1565 * `HAVE_VFORK', `HAVE_DUP2' and `HAVE_GETTIMEOFDAY'.
1566
1567 These flags just say whether certain system calls are available.
1568
1569 * New macros control compiler switches, linker switches and libraries.
1570
1571 The m- and s- files can now control in a modular fashion the precise
1572 arguments passed to `cc' and `ld'.
1573
1574 LIBS_STANDARD defines the standard C libraries. Default is `-lc'.
1575 LIBS_DEBUG defines the extra libraries to use when debugging. Default `-lg'.
1576 LIBS_SYSTEM can be defined by the s- file to specify extra libraries.
1577 LIBS_MACHINE can be defined by the m- file to specify extra libraries.
1578 LIBS_TERMCAP defines the libraries for Termcap or Terminfo.
1579 It is defined by default in a complicated fashion but the m- or s- file
1580 can override it.
1581
1582 LD_SWITCH_SYSTEM can be defined by the s- file to specify extra `ld' switches.
1583 The default is `-X' on BSD systems except those few that use COFF object files.
1584 LD_SWITCH_MACHINE can be defined by the m- file to specify extra `ld' switches.
1585
1586 C_DEBUG_SWITCH defines the switches to give `cc' when debugging. Default `-g'.
1587 C_OPTIMIZE_SWITCH defines the switches to give `cc' to optimize. Default `-O'.
1588 C_SWITCH_MACHINE can be defined by the m- file to specify extra `cc' switches.
1589 \f
1590 For older news, see the file ONEWS.2.
1591
1592 ----------------------------------------------------------------------
1593 Copyright information:
1594
1595 Copyright (C) 1988 Free Software Foundation, Inc.
1596
1597 Permission is granted to anyone to make or distribute verbatim copies
1598 of this document as received, in any medium, provided that the
1599 copyright notice and this permission notice are preserved,
1600 thus giving the recipient permission to redistribute in turn.
1601
1602 Permission is granted to distribute modified versions
1603 of this document, or of portions of it,
1604 under the above conditions, provided also that they
1605 carry prominent notices stating who last changed them.
1606 \f
1607 Local variables:
1608 mode: text
1609 end:
1610
1611 arch-tag: 8fed393b-c9c5-47d1-afbb-c0e7a135094a