xref: /freebsd/contrib/less/version.c (revision 0bf48626aaa33768078f5872b922b1487b3a9296)
1 /*
2  * Copyright (C) 1984-2019  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 /*
12 ----------------------- CHANGE HISTORY --------------------------
13 
14        1/29/84  Allowed use on standard input
15        2/1/84   Added E, N, P commands
16        4/17/84  Added '=' command, 'stop' signal handling
17        4/20/84  Added line folding
18 v2     4/27/84  Fixed '=' command to use BOTTOM_PLUS_ONE,
19                 instead of TOP, added 'p' & 'v' commands
20 v3     5/3/84   Added -m and -t options, '-' command
21 v4     5/3/84   Added LESS environment variable
22 v5     5/3/84   New comments, fixed '-' command slightly
23 v6     5/15/84  Added -Q, visual bell
24 v7     5/24/84  Fixed jump_back(n) bug: n should count real
25                 lines, not folded lines.  Also allow number on G command.
26 v8     5/30/84  Re-do -q and -Q commands
27 v9     9/25/84  Added "+<cmd>" argument
28 v10    10/10/84 Fixed bug in -b<n> argument processing
29 v11    10/18/84 Made error() ring bell if \n not entered.
30 -----------------------------------------------------------------
31 v12    2/13/85  Reorganized signal handling and made portable to 4.2bsd.
32 v13    2/16/85  Reword error message for '-' command.
33 v14    2/22/85  Added -bf and -bp variants of -b.
34 v15    2/25/85  Miscellaneous changes.
35 v16    3/13/85  Added -u flag for backspace processing.
36 v17    4/13/85  Added j and k commands, changed -t default.
37 v18    4/20/85  Rewrote signal handling code.
38 v19    5/2/85   Got rid of "verbose" eq_message().
39                 Made search() scroll in some cases.
40 v20    5/21/85  Fixed screen.c ioctls for System V.
41 v21    5/23/85  Fixed some first_cmd bugs.
42 v22    5/24/85  Added support for no RECOMP nor REGCMP.
43 v23    5/25/85  Miscellanous changes and prettying up.
44                 Posted to USENET.
45 -----------------------------------------------------------------
46 v24    6/3/85   Added ti,te terminal init & de-init.
47                 (Thanks to Mike Kersenbrock)
48 v25    6/8/85   Added -U flag, standout mode underlining.
49 v26    6/9/85   Added -M flag.
50                 Use underline termcap (us) if it exists.
51 v27    6/15/85  Renamed some variables to make unique in
52                 6 chars.  Minor fix to -m.
53 v28    6/28/85  Fixed right margin bug.
54 v29    6/28/85  Incorporated M.Rose's changes to signal.c
55 v30    6/29/85  Fixed stupid bug in argument processing.
56 v31    7/15/85  Added -p flag, changed repaint algorithm.
57                 Added kludge for magic cookie terminals.
58 v32    7/16/85  Added cat_file if output not a tty.
59 v33    7/23/85  Added -e flag and EDITOR.
60 v34    7/26/85  Added -s flag.
61 v35    7/27/85  Rewrote option handling; added option.c.
62 v36    7/29/85  Fixed -e flag to work if not last file.
63 v37    8/10/85  Added -x flag.
64 v38    8/19/85  Changed prompting; created prompt.c.
65 v39    8/24/85  (Not -p) does not initially clear screen.
66 v40    8/26/85  Added "skipping" indicator in forw().
67                 Posted to USENET.
68 -----------------------------------------------------------------
69 v41    9/17/85  ONLY_RETURN, control char commands,
70                 faster search, other minor fixes.
71 v42    9/25/85  Added ++ command line syntax;
72                 ch_fsize for pipes.
73 v43    10/15/85 Added -h flag, changed prim.c algorithms.
74 v44    10/16/85 Made END print in all cases of eof;
75                 ignore SIGTTOU after receiv ing SIGTSTP.
76 v45    10/16/85 Never print backspaces unless -u.
77 v46    10/24/85 Backwards scroll in jump_loc.
78 v47    10/30/85 Fixed bug in edit(): *first_cmd==0
79 v48    11/16/85 Use TIOCSETN instead of TIOCSETP.
80                 Added marks (m and ' commands).
81                 Posted to USENET.
82 -----------------------------------------------------------------
83 v49    1/9/86   Fixed bug: signal didn't clear mcc.
84 v50    1/15/86  Added ' (quote) to gomark.
85 v51    1/16/86  Added + cmd, fixed problem if first_cmd
86                 fails, made g cmd sort of "work" on pipes
87                 ev en if bof is no longer buffered.
88 v52    1/17/86  Made short files work better.
89 v53    1/20/86  Added -P option.
90 v54    1/20/86  Changed help to use HELPFILE.
91 v55    1/23/86  Messages work better if not tty output.
92 v56    1/24/86  Added -l option.
93 v57    1/31/86  Fixed -l to get confirmation before
94                 ov erwriting an existing file.
95 v58    8/28/86  Added filename globbing.
96 v59    9/15/86  Fixed some bugs with very long filenames.
97 v60    9/26/86  Incorporated changes from Leith (Casey)
98                 Leedom for boldface and -z option.
99 v61    9/26/86  Got rid of annoying repaints after ! cmd.
100                 Posted to USENET.
101 -----------------------------------------------------------------
102 v62    12/23/86 Added is_directory(); change -z default to
103                 -1 instead of 24; cat-and-exit if -e and
104                 file is less than a screenful.
105 v63    1/8/87   Fixed bug in cat-and-exit if > 1 file.
106 v64    1/12/87  Changed puts/putstr, putc/putchr,
107                 getc/getchr to av oid name conflict with
108                 stdio functions.
109 v65    1/26/87  Allowed '-' command to change NUMBER
110                 v alued options (thanks to Gary Puckering)
111 v66    2/13/87  Fixed bug: prepaint should use force=1.
112 v67    2/24/87  Added !! and % expansion to ! command.
113 v68    2/25/87  Added SIGWINCH and TIOCGWINSZ support;
114                 changed is_directory to bad_file.
115                 (thanks to J. Robert Ward)
116 v69    2/25/87  Added SIGWIND and WIOCGETD (for Unix PC).
117 v70    3/13/87  Changed help cmd from 'h' to 'H'; better
118                 error msgs in bad_file, errno_message.
119 v71    5/11/87  Changed -p to -c, made triple -c/-C
120                 for clear-eol like more's -c.
121 v72    6/26/87  Added -E, -L, use $SHELL in lsystem().
122                 (thanks to Stev e Spearman)
123 v73    6/26/87  Allow Examine "#" for previous file.
124                 Posted to USENET 8/25/87.
125 -----------------------------------------------------------------
126 v74    9/18/87  Fix conflict in EOF symbol with stdio.h,
127                 Make os.c more portable to BSD.
128 v75    9/23/87  Fix problems in get_term (thanks to
129                 Paul Eggert); new backwards scrolling in
130                 jump_loc (thanks to Marion Hakanson).
131 v76    9/23/87  Added -i flag; allow single "!" to
132                 inv oke a shell (thanks to Franco Barber).
133 v77    9/24/87  Added -n flag and line number support.
134 v78    9/25/87  Fixed problem with prompts longer than
135                 the screen width.
136 v79    9/29/87  Added the _ command.
137 v80    10/6/87  Allow signal to break out of linenum scan.
138 v81    10/6/87  Allow -b to be changed from within less.
139 v82    10/7/87  Add cmd_decode to use a table for key
140                 binding (thanks to Dav id Nason).
141 v83    10/9/87  Allow .less file for user-defined keys.
142 v84    10/11/87 Fix -e/-E problems (thanks to Felix Lee).
143 v85    10/15/87 Search now keeps track of line numbers.
144 v86    10/20/87 Added -B option and autobuf; fixed
145                 "pipe error" bug.
146 v87    3/1/88   Fix bug re BSD signals while reading file.
147 v88    3/12/88  Use new format for -P option (thanks to
148                 der Mouse), allow "+-c" without message,
149                 fix bug re BSD hangup.
150 v89    3/18/88  Turn off line numbers if linenum scan
151                 is interrupted.
152 v90    3/30/88  Allow -P from within less.
153 v91    3/30/88  Added tags file support (new -t option)
154                 (thanks to Brian Campbell).
155 v92    4/4/88   Added -+option syntax.
156 v93    4/11/88  Add support for slow input (thanks to
157                 Joe Orost & apologies for taking almost
158                 3 years to get this in!)
159 v94    4/11/88  Redo reading/signal stuff.
160 v95    4/20/88  Repaint screen better after signal.
161 v96    4/21/88  Add /! and ?! commands.
162 v97    5/17/88  Allow -l/-L from within less.
163                 Eliminate some static arrays (use calloc).
164                 Posted to USENET.
165 -----------------------------------------------------------------
166 v98    10/14/88 Fix incorrect calloc call; uninitialized
167                 var in exec_mca; core dump on unknown TERM.
168                 Make v cmd work if past last line of file.
169                 Fix some signal bugs.
170 v99    10/29/88 Allow space between -X and string,
171                 when X is a string-valued option.
172 v100   1/5/89   Fix globbing bug when $SHELL not set;
173                 allow spaces after -t command.
174 v101   1/6/89   Fix problem with long (truncated) lines
175                 in tags file (thanks to Neil Dixon).
176 v102   1/6/89   Fix bug with E# when no prev file;
177                 allow spaces after -l command.
178 v103   3/14/89  Add -N, -f and -? options.  Add z and w
179                 commands.  Add %L for prompt strings.
180 v104   3/16/89  Added EDITPROTO.
181 v105   3/20/89  Fix bug in find_linenum which cached
182                 incorrectly on long lines.
183 v106   3/31/89  Added -k option and multiple lesskey
184                 files.
185 v107   4/27/89  Add 8-bit char support and -g option.
186                 Split option code into 3 files.
187 v108   5/5/89   Allocate position table dynamically
188                 (thanks to Paul Eggert); change % command
189                 from "percent" to vi-style brace finder.
190 v109   5/10/89  Added ESC-% command, split prim.c.
191 v110   5/24/89  Fixed bug in + option; fixed repaint bug
192                 under Sun windows (thanks to Paul Eggert).
193 v111   5/25/89  Generalized # and % expansion; use
194                 calloc for some error messages.
195 v112   5/30/89  Get rid of ESC-%, add {}()[] commands.
196 v113   5/31/89  Optimize lseeks (thanks to Paul Eggert).
197 v114   7/25/89  Added ESC-/ and ESC-/! commands.
198 v115   7/26/89  Added ESC-n command.
199 v116   7/31/89  Added find_pos to optimize g command.
200 v117   8/1/89   Change -f option to -r.
201 v118   8/2/89   Save positions for all previous files,
202                 not just the immediately previous one.
203 v119   8/7/89   Save marks across file boundaries.
204                 Add file handle stuff.
205 v120   8/11/89  Add :ta command.
206 v121   8/16/89  Add -f option.
207 v122   8/30/89  Fix performance with many buffers.
208 v123   8/31/89  Verbose prompts for string options.
209                 Posted beta to USENET.
210 -----------------------------------------------------------------
211 v124   9/18/89  Reorganize search commands,
212                 N = rev, ESC-n = span, add ESC-N.
213 v125   9/18/89  Fix tab bug (thanks to Alex Liu).
214                 Fix EOF bug when both -w and -c.
215 v126   10/25/89 Add -j option.
216 v127   10/27/89 Fix problems with blank lines before BOF.
217 v128   10/27/89 Add %bj, etc. to prompt strings.
218 v129   11/3/89  Add -+,-- commands; add set-option and
219                 unset-option to lesskey.
220 v130   11/6/89  Generalize A_EXTRA to string, remove
221                 set-option, unset-option from lesskey.
222 v131   11/7/89  Changed name of EDITPROTO to LESSEDIT.
223 v132   11/8/89  Allow editing of command prefix.
224 v133   11/16/89 Add -y option (thanks to Jeff Sullivan).
225 v134   12/1/89  Glob filenames in the -l command.
226 v135   12/5/89  Combined {}()[] commands into one, and
227                 added ESC-^F and ESC-^B commands.
228 v136   1/20/90  Added -S, -R flags.  Added | command.
229                 Added warning for binary files. (thanks
230                 to Richard Brittain and J. Sullivan).
231 v137   1/21/90  Rewrote horrible pappend code.
232                 Added * notation for hi-bit chars.
233 v138   1/24/90  Fix magic cookie terminal handling.
234                 Get rid of "cleanup" loop in ch_get.
235 v139   1/27/90  Added MSDOS support.  (many thanks
236                 to Richard Brittain).
237 v140   2/7/90   Editing a new file adds it to the
238                 command line list.
239 v141   2/8/90   Add edit_list for editing >1 file.
240 v142   2/10/90  Add :x command.
241 v143   2/11/90  Add * and @ modifies to search cmds.
242                 Change ESC-/ cmd from /@* to / *.
243 v144   3/1/90   Messed around with ch_zero;
244                 no real change.
245 v145   3/2/90   Added -R and -v/-V for MSDOS;
246                 renamed FILENAME to avoid conflict.
247 v146   3/5/90   Pull cmdbuf functions out of command.c
248 v147   3/7/90   Implement ?@; fix multi-file edit bugs.
249 v148   3/29/90  Fixed bug in :e<file> then :e#.
250 v149   4/3/90   Change error,ierror,query to use PARG.
251 v150   4/6/90   Add LESS_CHARSET, LESS_CHARDEF.
252 v151   4/13/90  Remove -g option; clean up ispipe.
253 v152   4/14/90  lsystem() closes input file, for
254                 editors which require exclusive open.
255 v153   4/18/90  Fix bug if SHELL unset;
256                 fix bug in overstrike control char.
257 v154   4/25/90  Output to fd 2 via buffer.
258 v155   4/30/90  Ignore -i if uppercase in pattern
259                 (thanks to Michael Rendell.)
260 v156   5/3/90   Remove scroll limits in forw() & back();
261                 causes problems with -c.
262 v157   5/4/90   Forward search starts at next real line
263                 (not screen line) after jump target.
264 v158   6/14/90  Added F command.
265 v159   7/29/90  Fix bug in exiting: output not flushed.
266 v160   7/29/90  Clear screen before initial output w/ -c.
267 v161   7/29/90  Add -T flag.
268 v162   8/14/90  Fix bug with +F on command line.
269 v163   8/21/90  Added LESSBINFMT variable.
270 v164   9/5/90   Added -p, LINES, COLUMNS and
271                 unset mark ' == BOF, for 1003.2 D5.
272 v165   9/6/90   At EOF with -c set, don't display empty
273                 screen when try to page forward.
274 v166   9/6/90   Fix G when final line in file wraps.
275 v167   9/11/90  Translate CR/LF -> LF for 1003.2.
276 v168   9/13/90  Return to curr file if "tag not found".
277 v169   12/12/90 G goes to EOF even if file has grown.
278 v170   1/17/91  Add optimization for BSD _setjmp;
279                 fix #include ioctl.h TERMIO problem.
280                 (thanks to Paul Eggert)
281                 Posted to USENET.
282 -----------------------------------------------------------------
283 v171   3/6/91   Fix -? bug in get_filename.
284 v172   3/15/91  Fix G bug in empty file.
285                 Fix bug with ?\n and -i and uppercase
286                 pattern at EOF!
287                 (thanks to Paul Eggert)
288 v173   3/17/91  Change N cmd to not permanently change
289                 direction. (thanks to Brian Matthews)
290 v174   3/18/91  Fix bug with namelogfile not getting
291                 cleared when change files.
292 v175   3/18/91  Fix bug with ++cmd on command line.
293                 (thanks to Jim Meyering)
294 v176   4/2/91   Change | to not force current screen,
295                 include marked line, start/end from
296                 top of screen.  Improve search speed.
297                 (thanks to Don Mears)
298 v177   4/2/91   Add LESSHELP variable.
299                 Fix bug with F command with -e.
300                 Try /dev/tty for input before using fd 2.
301                 Patches posted to USENET  4/2/91.
302 -----------------------------------------------------------------
303 v178   4/8/91   Fixed bug in globbing logfile name.
304                 (thanks to Jim Meyering)
305 v179   4/9/91   Allow negative -z for screen-relative.
306 v180   4/9/91   Clear to eos rather than eol if "db";
307                 don't use "sr" if "da".
308                 (thanks to Tor Lillqvist)
309 v181   4/18/91  Fixed bug with "negative" chars 80 - FF.
310                 (thanks to Benny Sander Hofmann)
311 v182   5/16/91  Fixed bug with attribute at EOL.
312                 (thanks to Brian Matthews)
313 v183   6/1/91   Rewrite linstall to do smart config.
314 v184   7/11/91  Process \b in searches based on -u
315                 rather than -i.
316 v185   7/11/91  -Pxxx sets short prompt; assume SIGWINCH
317                 after a SIGSTOP. (thanks to Ken Laprade)
318 -----------------------------------------------------------------
319 v186   4/20/92  Port to MS-DOS (Microsoft C).
320 v187   4/23/92  Added -D option & TAB_COMPLETE_FILENAME.
321 v188   4/28/92  Added command line editing features.
322 v189   12/8/92  Fix mem overrun in anscreen.c:init;
323                 fix edit_list to recover from bin file.
324 v190   2/13/93  Make TAB enter one filename at a time;
325                 create ^L with old TAB functionality.
326 v191   3/10/93  Defer creating "flash" page for MS-DOS.
327 v192   9/6/93   Add BACK-TAB.
328 v193   9/17/93  Simplify binary_file handling.
329 v194   1/4/94   Add rudiments of alt_filename handling.
330 v195   1/11/94  Port back to Unix; support keypad.
331 -----------------------------------------------------------------
332 v196   6/7/94   Fix bug with bad filename; fix IFILE
333                 type problem. (thanks to David MacKenzie)
334 v197   6/7/94   Fix bug with .less tables inserted wrong.
335 v198   6/23/94  Use autoconf installation technology.
336                 (thanks to David MacKenzie)
337 v199   6/29/94  Fix MS-DOS build (thanks to Tim Wiegman).
338 v200   7/25/94  Clean up copyright, minor fixes.
339         Posted to prep.ai.mit.edu
340 -----------------------------------------------------------------
341 v201   7/27/94  Check for no memcpy; add casts to calloc;
342                 look for regcmp in libgen.a.
343                 (thanks to Kaveh Ghazi).
344 v202   7/28/94  Fix bug in edit_next/edit_prev with
345                 non-existent files.
346 v203   8/2/94   Fix a variety of configuration bugs on
347                 various systems. (thanks to Sakai
348                 Kiyotaka, Harald Koenig, Bjorn Brox,
349                 Teemu Rantanen, and Thorsten Lockert)
350 v204   8/3/94   Use strerror if available.
351                 (thanks to J.T. Conklin)
352 v205   8/5/94   Fix bug in finding "me" termcap entry.
353                 (thanks to Andreas Stolcke)
354 8/10/94         v205+: Change BUFSIZ to LBUFSIZE to avoid name
355                 conflict with stdio.h.
356                 Posted to prep.ai.mit.edu
357 -----------------------------------------------------------------
358 v206   8/10/94  Use initial_scrpos for -t to avoid
359                 displaying first page before init().
360                 (thanks to Dominique Petitpierre)
361 v207   8/12/94  Fix bug if stdout is not tty.
362 v208   8/16/94  Fix bug in close_altfile if goto err1
363                 in edit_ifile. (Thanks to M.J. Hewitt)
364 v209   8/16/94  Change scroll to wscroll to avoid
365                 conflict with library function.
366 v210   8/16/94  Fix bug with bold on 8 bit chars.
367                 (thanks to Vitor Duarte)
368 v211   8/16/94  Don't quit on EOI in jump_loc / forw.
369 v212   8/18/94  Use time_t if available.
370 v213   8/20/94  Allow ospeed to be defined in termcap.h.
371 v214   8/20/94  Added HILITE_SEARCH, -F, ESC-u cmd.
372                 (thanks to Paul Lew and Bob Byrnes)
373 v215   8/23/94  Fix -i toggle behavior.
374 v216   8/23/94  Process BS in all searches, not only -u.
375 v217   8/24/94  Added -X flag.
376 v218   8/24/94  Reimplement undo_search.
377 v219   8/24/94  Find tags marked with line number
378                 instead of pattern.
379 v220   8/24/94  Stay at same position after SIG_WINCH.
380 v221   8/24/94  Fix bug in file percentage in big file.
381 v222   8/25/94  Do better if can't reopen current file.
382 v223   8/27/94  Support setlocale.
383                 (thanks to Robert Joop)
384 v224   8/29/94  Revert v216: process BS in search
385                 only if -u.
386 v225   9/6/94   Rewrite undo_search again: toggle.
387 v226   9/15/94  Configuration fixes.
388                 (thanks to David MacKenzie)
389 v227   9/19/94  Fixed strerror config problem.
390                 Posted to prep.ai.mit.edu
391 -----------------------------------------------------------------
392 v228   9/21/94  Fix bug in signals: repeated calls to
393                 get_editkeys overflowed st_edittable.
394 v229   9/21/94  Fix "Nothing to search" error if -a
395                 and SRCH_PAST_EOF.
396 v230   9/21/94  Don't print extra error msg in search
397                 after regerror().
398 v231   9/22/94  Fix hilite bug if search matches 0 chars.
399                 (thanks to John Polstra)
400 v232   9/23/94  Deal with weird systems that have
401                 termios.h but not tcgetattr().
402                 Posted to prep.ai.mit.edu
403 -----------------------------------------------------------------
404 v233   9/26/94  Use get_term() instead of pos_init() in
405                 psignals to re-get lower_left termcap.
406                 (Thanks to John Malecki)
407 v234   9/26/94  Make MIDDLE closer to middle of screen.
408 v235   9/27/94  Use local strchr if system doesn't have.
409 v236   9/28/94  Don't use libucb; use libterm if
410                 libtermcap & libcurses doesn't work.
411                 (Fix for Solaris; thanks to Frank Kaefer)
412 v237   9/30/94  Use system isupper() etc if provided.
413                 Posted to prep.ai.mit.edu
414 -----------------------------------------------------------------
415 v238   10/6/94  Make binary non-blinking if LESSBINFMT
416                 is set to a string without a *.
417 v239   10/7/94  Don't let delimit_word run back past
418                 beginning of cmdbuf.
419 v240   10/10/94 Don't write into termcap buffer.
420                 (Thanks to Benoit Speckel)
421 v241   10/13/94 New lesskey file format.
422                 Don't expand filenames in search command.
423 v242   10/14/94 Allow lesskey specification of "literal".
424 v243   10/14/94 Add #stop command to lesskey.
425 v244   10/16/94 Add -f flag to lesskey.
426 v245   10/25/94 Allow TAB_COMPLETE_FILENAME to be undefd.
427 v246   10/27/94 Move help file to /usr/local/share.
428 v247   10/27/94 Add -V option.
429 v248   11/5/94  Add -V option to lesskey.
430 v249   11/5/94  Remove -f flag from lesskey; default
431                 input file is ~/.lesskey.in, not stdin.
432 v250   11/7/94  Lesskey input file "-" means stdin.
433 v251   11/9/94  Convert cfgetospeed result to ospeed.
434                 (Thanks to Andrew Chernov)
435 v252   11/16/94 Change default lesskey input file from
436                 .lesskey.in to .lesskey.
437                 Posted to prep.ai.mit.edu
438 -----------------------------------------------------------------
439 v253   11/21/94 Fix bug when tags file has a backslash.
440 v254   12/6/94  Fix -k option.
441 v255   12/8/94  Add #define EXAMINE to disable :e etc.
442 v256   12/10/94 Change highlighting: only highlite search
443                 results (but now it is reliable).
444 v257   12/10/94 Add goto_line and repaint_highlight
445                 to optimize highlight repaints.
446 v258   12/12/94 Fixup in hilite_line if BS_SPECIAL.
447 v259   12/12/94 Convert to autoconf 2.0.
448 v260   12/13/94 Add SECURE define.
449 v261   12/14/94 Use system WERASE char as EC_W_BACKSPACE.
450 v262   12/16/94 Add -g/-G flag and screen_hilite.
451 v263   12/20/94 Reimplement/optimize -G flag behavior.
452 v264   12/23/94 Allow EXTRA string after line-edit cmd
453                 in lesskey file.
454 v265   12/24/94 Add LESSOPEN=|cmd syntax.
455 v266   12/26/94 Add -I flag.
456 v267   12/28/94 Formalize the four-byte header emitted
457                 by a LESSOPEN pipe.
458 v268   12/28/94 Get rid of four-byte header.
459 v269   1/2/95   Close alt file before open new one.
460                 Avoids multiple popen().
461 v270   1/3/95   Use VISUAL; use S_ISDIR/S_ISREG; fix
462                 config problem with Solaris POSIX regcomp.
463 v271   1/4/95   Don't quit on read error.
464 v272   1/5/95   Get rid of -L.
465 v273   1/6/95   Fix ch_ungetchar bug; don't call
466                 LESSOPEN on a pipe.
467 v274   1/6/95   Ported to OS/2 (thanks to Kai Uwe Rommel)
468 v275   1/18/95  Fix bug if toggle -G at EOF.
469 v276   1/30/95  Fix OS/2 version.
470 v277   1/31/95  Add "next" charset; don't display ^X
471                 for X > 128.
472 v278   2/14/95  Change default for -G.
473                 Posted to prep.ai.mit.edu
474 -----------------------------------------------------------------
475 v279   2/22/95  Add GNU options --help, --version.
476                 Minor config fixes.
477 v280   2/24/95  Clean up calls to glob(); don't set #
478                 if we can't open the new file.
479 v281   2/24/95  Repeat search should turn on hilites.
480 v282   3/2/95   Minor fixes.
481 v283   3/2/95   Fix homefile; make OS2 look in $HOME.
482 v284   3/2/95   Error if "v" on LESSOPENed file;
483                 "%" figures out file size on pipe.
484 v285   3/7/95   Don't set # in lsystem;
485                 lesskey try $HOME first.
486 v286   3/7/95   Reformat change history (too much free time?).
487 v287   3/8/95   Fix hilite bug if overstrike multiple chars.
488 v288   3/8/95   Allow lesskey to override get_editkey keys.
489 v289   3/9/95   Fix adj_hilite bug when line gets processed by
490                 hilite_line more than once.
491 v290   3/9/95   Make configure automatically.  Fix Sequent problem
492                 with incompatible sigsetmask().
493                 Posted to prep.ai.mit.edu
494 -----------------------------------------------------------------
495 v291   3/21/95  Add #env to lesskey.  Fix MS-DOS build.
496                 Posted to simtel.
497 -----------------------------------------------------------------
498 v292   4/24/95  Add MS-DOS support for Borland C.
499                 Fix arrow keys in MS-DOS versions.
500 v293   4/28/95  Add auto-versioning stuff to make dist.
501 v294   5/12/95  Fix Borland build.
502 v295   1/20/96  Fix search on squished file; add /@@.
503 v296   1/23/96  Allow cmdbuf larger than screen width.
504 v297   1/24/96  Don't call termcap if tgetent fails;
505                 add #defines for buffers.
506 v298   1/24/96  Change @@ to ^K.
507                 Add alternate search modifiers ^N, ^F, ^E.
508 v299   1/25/96  Fix percent overflow in jump_percent (thanks to Brent Wiese);
509                 don't send "ti" after shell command till RETURN pressed.
510 v300   1/25/96  Change -U to print tabs as ^I.
511 v301   1/30/96  Make hilites work in cmd F output.
512 v302   1/31/96  Fix cmd F to notice window-change signals.
513 v303   1/31/96  Add ESC-SPACE command.
514 v304   2/1/96   Add ^R search modifier; add LESSSECURE.
515 v305   2/2/96   Workaround Linux /proc kernel bug; add LESSKEY.
516 v306   3/16/96  Minor fixes.
517 v307   3/25/96  Allow cmd line arg "--"; fix DOS & OS/2 defines.h.
518 v308   4/4/96   Port to OS-9 (thanks to Boisy Pitre); fix -d.
519 v309   4/9/96   Fix OS-9 version; fix tags bug with "$".
520 v310   4/10/96  Get rid of HELPFILE.
521 v311   4/22/96  Add Windows32 support; merge doscreen.c into screen.c.
522 v312   4/24/96  Don't quit after "cannot reopen" error.
523 v313   4/25/96  Added horizontal scrolling.
524 v314   4/26/96  Modified -e to quit on reaching end of a squished file.
525 v315   4/26/96  Fix "!;TAB" bug.
526 v316   5/2/96   Make "|a" when (a < curr screen) go to end of curr screen.
527 v317   5/14/96  Various fixes for the MS-DOS and OS/2 builds.
528                 Added ## and %% handling for filenames
529 v318   5/29/96  Port to OS-9 Microware compiler; minor fixes
530                 (thanks to Martin Gregorie).
531 v319   7/8/96   Fix Windows port (thanks to Jeff Paquette).
532 v320   7/11/96  Final fixes for Windows port.
533 v321   7/18/96  Minor fixes.
534                 Posted to Web page.
535 -----------------------------------------------------------------
536 v322   8/13/96  Fix bug in shell escape from help file; add support for
537                 Microsoft Visual C under Windows; numerous small fixes.
538 v323   8/19/96  Fixes for Windows version (thanks to Simon Munton);
539                 fix for Linux library weirdness (thanks to Jim Diamond);
540                 port to DJGPP (thanks to Eli Zaretskii).
541 v324   8/21/96  Add support for spaces in filenames (thanks to Simon Munton).
542 v325   8/21/96  Add lessecho, for spaces in filenames under Unix.
543 v326   8/27/96  Fix DJGPP version.
544 v327   9/1/96   Reorganize lglob, make spaces in filenames work better in Unix.
545 v328   10/7/96  Append / to directory name in filename completion.
546                 Fix MS-DOS and OS-9 versions.
547 v329   10/11/96 Fix more MS-DOS bugs; add LESSSEPARATOR; add -" option.
548                 Add LESSMETACHARS, LESSMETAESCAPE.
549 v330   10/21/96 Minor fixes.
550                 Posted to Web page.
551 -----------------------------------------------------------------
552 v331   4/22/97  Various Windows fixes (thanks to Gurusamy Sarathy).
553 v332   4/22/97  Enter filenames from cmd line into edit history.
554                 Posted to Web page.
555 -----------------------------------------------------------------
556 v333    3/4/99  Changed -w to highlite new line after forward movement.
557 v334    3/9/99  Avoid overflowing prompt buffer; add %d and %D.
558 v335   3/20/99  Add EBCDIC support (thanks to Thomas Dorner).
559                 Use HOMEDRIVE/HOMEPATH on Windows (thanks to Preston Bannister).
560                 Posted to Web page.
561 -----------------------------------------------------------------
562 v336    4/8/99  Fix installation bugs.
563 v337    4/9/99  Fix another installation bug.
564                 Posted to Web page.
565 -----------------------------------------------------------------
566 v338   4/13/99  Add support for long option names.
567 v339   4/18/99  Add \k, long option names to lesskey.  Add -^P.  Add :d.
568 v340   4/21/99  Add regexec2.  Fix Windows build.
569                 Posted to Web page.
570 -----------------------------------------------------------------
571 v341    5/6/99  Add -F option; %c & ?c prompt escapes.
572                 (Thanks to Michele Maltoni)
573 v342   7/22/99  Add system-wide lesskey file; allow GPL or Less License.
574 v343   9/23/99  Support UTF-8 (Thanks to Robert Brady).
575                 Add %P and ?P in prompts.
576 v344  10/27/99  -w highlights target line of g and p commands.
577 v345  10/29/99  Make -R pass thru ESC but not other control chars.
578                 Posted to Web page.
579 -----------------------------------------------------------------
580 v346   11/4/99  Fix bugs in long option processing; R cmd should clear hilites.
581                 Posted to Web page.
582 -----------------------------------------------------------------
583 v347  12/13/99  Fixes for DJGPP version (thanks to Eli Zaretskii).
584 v348  12/28/99  Fix deleting file with marks (thanks to Dimitar Jekov).
585                 Fix color problem in DJGPP version (thanks to Eli Zaretskii).
586 v349   1/24/00  Fix minor DJGPP bugs; check environment vars for UTF-8;
587                 add --with-editor (thanks to Eli, Markus Kuhn, Thomas Schoepf).
588 v350   3/1/00   Fix clear-while-standout bug.
589 v351   3/5/00   Change -M and = prompts to show top & bottom line number.
590                 Posted to Web page.
591 -----------------------------------------------------------------
592 v352   3/8/00   Fix scan_option NULL dereference.
593 -----------------------------------------------------------------
594 v353   3/20/00  Fix SECURE compile bug, allow space after numeric option.
595 v354   3/23/00  Add support for PCRE; add --with-regex configure option.
596 -----------------------------------------------------------------
597 v355   6/28/00  Add -# option (thanks to Andy Levinson).
598 v356   7/5/00   Add -J option.
599 v357   7/6/00   Support sigprocmask.
600 -----------------------------------------------------------------
601 v358   7/8/00   Fix problems with #stop in lesskey file.
602                 Posted to Web page.
603 -----------------------------------------------------------------
604 v359  9/10/00   Fixes for Win32 display problems (thanks to Maurizio Vairani).
605 v360  1/17/01   Move sysless to etc.
606 v361  12/4/01   Add IBM-1047 charset & EBCDIC fixes (thanks to Thomas Dorner).
607                 Fix 32 bit dependencies (thanks to Paul Eggert).
608                 Fix UTF-8 overstriking (thanks to Robert Brady).
609 v362  12/4/01   Make status column show search targets.
610 v363  12/6/01   Add --no-keypad option.
611                 Add variable width tabstops (thanks to Peter Samuelson).
612 v364 12/10/01   Better handling of very long lines in input;
613                 Fix horizontal shifting of colored text.
614 v365 12/11/01   Fix overstriking of tabs;
615                 Add support for global(1) and multiple tag matches
616                 (thanks to Shigio Yamaguchi and Tim Vanderhoek).
617 v366 12/11/01   Fixes for OS/2 (thanks to Kyosuke Tokoro).
618 v367 12/13/01   Allow -D and -x options to terminate without dollar sign;
619                 Right/left arrow when entering N are shift cmds, not line edit.
620 v368 12/18/01   Update lesskey commands.
621 v370 12/23/01   Fix tags error messages.
622                 Posted to Web page.
623 -----------------------------------------------------------------
624 v371 12/26/01   Fix new_file bug; use popen in Windows version;
625                 fix some compiler warnings.
626 v372 12/29/01   Make -b be in units of 1K.
627 v373  1/14/02   Improve handling of filenames containing shell metachars.
628 v374   2/7/02   Fix memory leak; fix bug in -x argument parsing.
629 v375   4/7/02   Fix searching for SGR sequences; fix SECURE build;
630                 add SGR support to DJGPP version (thanks to Eli Zaretskii).
631 v376  6/10/02   Fix bug in overstriking mulitbyte UTF-8 characters
632                 (thanks to Jungshik Shin).
633                 Posted to Web page.
634 -----------------------------------------------------------------
635 v377  9/10/02   Fix bug in Windows version when file contains CR;
636                 fix bug in search highlights with -R;
637                 make initial buffer limit really be 64K not unlimited.
638 v378  9/30/02   Misc bug fixes and compiler warning cleanup.
639                 Posted to Web page.
640 -----------------------------------------------------------------
641 v379 11/23/02   Add -L option; fix bug with ctrl-K in lesskey files;
642                 improve UTF-8 overstriking and underscore overstriking;
643                 fix minor man page problems; change to autoconf 2.54.
644 v380 11/24/02   Make LINENUM same as POSITION.
645 v381 11/28/02   Make -N use 7 columns for line number if possible.
646 -----------------------------------------------------------------
647 v382   2/3/04   Remove copyrighted code.
648 -----------------------------------------------------------------
649 v383  2/16/04   Add history file; add -K option; improve UTF-8 handling;
650                 fix some signed char bugs (thanks to Christian Biere);
651                 fix some upper/lower case bugs (thanks to Bjoern Jacke);
652                 add erase2 char (thanks to David Lawrence);
653                 add windows charset (thanks to Dimitar Zhekov).
654 v384  2/20/04   Improvements in UTF-8 handling.
655 v385  2/23/04   Fix UTF-8 output bug.
656 -----------------------------------------------------------------
657 v386  9/13/05   Improvements to UTF-8 shift & color (thanks to Charles Levert);
658                 protect against invalid LESSOPEN and LESSCLOSE values.
659 v387  9/14/05   Update Charles Levert's UTF-8 patch.
660 v388  9/14/05   Change history behavior; change most sprintf calls to snprintf.
661 v389  9/14/05   Fix copy & paste with long lines; improve performance of
662                 expand_linebuf; fix crash in init_mlist;
663 v390  9/15/05   Show search matches in status column even if -G is set.
664 -----------------------------------------------------------------
665 v391  9/17/05   Fix bugs.
666 v392  10/14/05  Fix line wrapping bug.
667 v393  10/19/05  Allow multiple attributes per char; fix bold+underline bug
668                 (thanks again to Charles Levert).
669 v394  11/8/05   Fix prompt bug; fix compile problem in Windows build.
670 -----------------------------------------------------------------
671 v395  1/12/07   Update Unicode tables (thanks to Charles Levert);
672                 don't chmod if LESSHISTFILE = /dev/null;
673                 make -f work for directories; support DESTDIR in Makefile;
674                 fix sigset_t detection in configure;
675                 make "t" cmd traverse tags in correct order
676 v396  1/13/07   Add compatibility with POSIX more.
677 v397  3/21/07   Allow decimal point in number for % command;
678                 Allow decimal point in number for -j option;
679                 Allow n command to fetch last search pattern from history
680                 (thanks to arno).
681 v398  3/22/07   Don't rewrite history file if not necessary;
682                 fix bug when filenames contain "$".
683 v399  3/22/07   Don't move to bottom of screen at startup;
684                 don't output extraneous newlines.
685 v400  3/23/07   Allow search to find pattern after null byte (PCRE and no-regex)
686                 (thanks to Michael Constant).
687 -----------------------------------------------------------------
688 v401  3/24/07   Minor documentation fixes.
689 v402  3/30/07   Fix autoconf bug when memcpy etc are inline;
690                 fix bug in terminating number following -j option.
691 v403  5/25/07   Fix Windows build.
692 v404  6/5/07    Fix display bug with F command and long lines.
693 v405  6/17/07   Fix display bug when using -w option.
694 v406  6/17/07   Fix secure build.
695 v407  8/16/07   Fix bugs; support CSI chars.
696 v408  10/1/07   Fix bug in -i with non-ASCII chars.
697 v409  10/12/07  Fix crash when viewing text with invalid UTF-8 sequences.
698 v411  11/6/07   Fix case-insensitive searching with non-ASCII text.
699 v412  11/6/07   Use symbolic SEEK constants.
700 v413  11/6/07   Fix search highlight bug with non-ASCII text.
701 v414  11/6/07   Fix display bug with no-wrap terminals.
702 v415  11/14/07  Add --follow-name option.
703 v416  11/22/07  Fix crash when searching text with invalid UTF-8 sequences.
704 v417  12/31/07  Don't support single-char CSI in UTF-8 mode;
705                 fix bug with -R and invalid CSI sequences;
706                 fix bug searching text with SGR sequences with -r;
707                 emulate SGR sequences in WIN32 build.
708 v418  12/31/07  Clean up.
709 -----------------------------------------------------------------
710 v419  1/16/08   Make CSI char 0x9B work in UTF-8 mode (thanks to Colin Watson).
711 v420  2/24/08   Add & command; fix -F option; fix '' after G.
712 v421  2/24/08   Ignore filtered lines when searching.
713 v422  3/2/08    Output CR at startup.
714 v423  5/27/08   Clean up.
715 v424  6/16/08   Fix compile bug with pcre; don't filter help file.
716 v425  7/14/08   Fix non-ANSI code in list handling in ch.c.
717 v426  10/27/08  Fix ignaw terminal handling (thanks to Per Hedeland);
718                 fix binary file detection in UTF-8 mode.
719 v427  3/16/09   A few Win32 fixes (thanks to Jason Hood).
720 v428  3/30/09   Add "|-" syntax to LESSOPEN.
721 v429  4/10/09   Fix search highlighting bug with underlined text.
722 -----------------------------------------------------------------
723 v430  4/22/09   Don't pass "-" to non-pipe LESSOPEN unless it starts with "-".
724 v431  4/29/09   Fix highlight bug when match is at end of line.
725 v432  6/27/09   Better fix for highlight bugs;
726                 fix new problems with ignaw terminals.
727 v433  6/28/09   Cleanup search code.
728 v434  6/29/09   More cleanup.
729 v435  7/04/09   Fix bugs with non-regex filtering.
730 v436  7/05/09   Fix memory leak.
731 -----------------------------------------------------------------
732 v437  7/14/09   Fix bug in handling some long option names;
733                 make percentage calculation more accurate.
734 v438  12/29/10  Fix bugs with -i/-I and & filtering;
735                 exit with status 2 on ctrl-C with -K.
736 v439  12/31/10  Add -A option.
737 v440  1/5/11    Fix bug displaying prompt after = command.
738 v441  1/21/11   Fix semi-infinite loop if no newlines in file;
739                 make new -A behavior the default.
740 -----------------------------------------------------------------
741 v442  3/2/11    Fix search bug.
742                 Add ctrl-G line edit command.
743 v443  4/9/11    Fix Windows build.
744 v444  6/8/11    Fix ungetc bug; remove vestiges of obsolete -l option.
745 -----------------------------------------------------------------
746 v445  10/19/11  Fix hilite bug in backwards scroll with -J.
747                 Fix hilite bug with backspaces.
748                 Fix bugs handling SGR sequences in Win32 (thanks to Eric Lee).
749                 Add support for GNU regex (thanks to Reuben Thomas).
750 v446  5/15/12   Up/down arrows in cmd editing search for matching cmd.
751 v447  5/21/12   Add ESC-F command, two-pipe LESSOPEN syntax.
752 v448  6/15/12   Print name of regex library in version message.
753 v449  6/23/12   Allow config option --with-regex=none.
754 v450  7/4/12    Fix EOF bug with ESC-F.
755 v451  7/20/12   Fix typo.
756 -----------------------------------------------------------------
757 v452  10/19/12  Fix --with-regex=none, fix "stty 0", fix Win32.
758                 Don't quit if errors in cmd line options.
759 v453  10/27/12  Increase buffer sizes.
760 v454  11/5/12   Fix typo.
761 v455  11/5/12   Fix typo.
762 v456  11/8/12   Fix option string incompatibility.
763 v457  12/8/12   Use new option string syntax only after --use-backslash.
764 v458  4/4/13    Fix display bug in using up/down in cmd buffer.
765 -----------------------------------------------------------------
766 v459  5/6/13    Fix ++ bug.
767 v460  6/19/13   Automate construction of Unicode tables.
768 v461  6/21/13   Collapse multiple CRs before LF.
769 v462  11/26/13  Don't overwrite history file, just append to it.
770 v463  7/13/14   Misc. fixes.
771 v464  7/19/14   Fix bugs & improve performance in & filtering
772                 (thanks to John Sullivan).
773 v465  8/9/14    More fixes from John Sullivan.
774 v466  8/23/14   Add colon to LESSANSIMIDCHARS.
775 v467  9/18/14   Misc. fixes.
776 v468  9/18/14   Fix typo
777 v469  10/2/14   Allow extra string in command to append to a multichar
778                 cmd without executing it; fix bug using GNU regex.
779 v470  10/5/14   Fix some compiler warnings.
780 v471  12/14/14  Fix unget issues with prompt. Allow disabling history
781                 when compiled value of LESSHISTFILE = "-".
782 v473  12/19/14  Fix prompt bug with stdin and -^P in lesskey extra string.
783 v474  1/30/15   Fix bug in backwards search with match on bottom line.
784                 Make follow mode reopen file if file shrinks.
785 v475  3/2/15    Fix possible buffer overrun with invalid UTF-8;
786                 fix bug when compiled with no regex; fix non-match search.
787 v476  5/3/15    Update man pages.
788 v477  5/19/15   Fix off-by-one in jump_forw_buffered;
789                 don't add FAKE_* files to cmd history.
790 v478  5/21/15   Fix nonportable pointer usage in hilite tree.
791 v479  7/6/15    Allow %% escapes in LESSOPEN variable.
792 v480  7/24/15   Fix bug in no-regex searches; support MSVC v1900.
793 v481  8/20/15   Fix broken -g option.
794 -----------------------------------------------------------------
795 v482  2/25/16   Update Unicode database to "2015-06-16, 20:24:00 GMT [KW]".
796 v483  2/27/16   Regenerate hilite when change search caselessness.
797                 (Thanks to Jason Hood)
798                 Fix bug when terminal has no "cm". (Thanks to Noel Cragg)
799 v484  9/20/16   Update to Unicode 9.0.0 database.
800 v485  10/21/16  Fix "nothing to search" bug when top/bottom line is empty;
801                 Display line numbers in bold. (thanks to Jason Hood);
802                 Fix incorrect display when entering double-width chars in
803                 search string.
804 v486  10/22/16  New commands ESC-{ and ESC-} to shift to start/end of
805                 displayed lines; new option -Da in Windows version to
806                 enable SGR mode (thanks to Jason Hood).
807 v487  10/23/16  configure --help formatting.
808 -----------------------------------------------------------------
809 v488  2/23/17   Fix memory leaks in search (thanks to John Brooks).
810 v489  3/30/17   Make -F not do init/deinit if file fits on one screen
811                 (thanks to Jindrich Novy).
812 v490  4/5/17    Switch to ANSI prototypes in funcs.h; remove "register".
813 v491  4/7/17    Fix signed char bug.
814 v492  4/21/17   Handle SIGTERM.
815 v493  6/22/17   Fix bug initializing charset in MSDOS build.
816 v494  6/26/17   Update Unicode tables; make Cf chars composing not binary.
817 v495  7/3/17    Improve binary file detection (thanks to Bela Lubkin);
818                 do -R filter when matching tags (thanks to Matthew Malcomson).
819 v496  7/5/17    Add LESSRSCROLL marker.
820 v497  7/5/17    Sync.
821 v498  7/7/17    Fix early truncation of text if last char is double-width.
822 v499  7/10/17   Misc fixes.
823 v500  7/11/17   Fix bug where certain env variables couldn't be set in lesskey.
824 v501  7/12/17   Make sure rscroll char is standout by default.
825 v502  7/13/17   Control rscroll char via command line option not env variable.
826 v503  7/13/17   Switch to git.
827 v504  7/13/17   Call opt_rscroll at startup; change mkhelp.c to mkhelp.pl.
828 v505  7/17/17   Add M and ESC-M commands;
829                 fix buffer handling with stdin and LESSOPEN.
830 v506  7/17/17   On Windows, convert UTF-8 to multibyte if console is not UTF-8;
831                 handle extended chars on input (thanks to Jason Hood).
832 v507  7/18/17   Fix some bugs handling filenames containing shell metachars.
833 v508  7/19/17   Fix bugs when using LESSOPEN to read stdin.
834 v509  7/19/17   Fix another stdin bug.
835 v510  7/20/17   Fix bug in determining when to reopen a file.
836 v511  7/25/17   Fix bugs in recent MSDOS changes (thanks to Jason Hood).
837 v512  7/26/17   Fix MSDOS build.
838 v513  7/26/17   Fix switch to normal attr at end of line with -R and rscroll.
839 v514  7/27/17   Fix bug in fcomplete when pattern does not match a file.
840 v515  7/28/17   Allow 'u' in -D option on Windows.
841 v516  7/29/17   Fix bug using LESSOPEN with filename containing metachars.
842 v517  7/30/17   Status column shows matches even if hiliting is disabled via -G.
843 v518  8/1/17    Use underline in sgr mode in MSDOS (thanks to Jason Hood).
844 v519  8/10/17   Fix rscroll bug when last char of line starts coloration.
845 v520  9/3/17    Fix compiler warning.
846 v521  10/20/17  Fix binary file warning in UTF-8 files with SGI sequences.
847 v522  10/20/17  Handle keypad ENTER key properly.
848 v523  10/23/17  Cleanup.
849 v524  10/24/17  Fix getcc bug.
850 v525  10/24/17  Change M command to mark last displayed line.
851 v526  10/25/17  Fix search hilite bug introduced in v517.
852 v527  10/30/17  Fix search hilite bug on last page with -a.
853 v528  11/3/17   Make second ESC-u clear status column.
854 v529  11/12/17  Display Unicode formatting chars in hex if -U is set.
855 v530  12/2/17   Minor doc change and add missing VOID_PARAM.
856 -----------------------------------------------------------------
857 v531  5/13/18   Fix bug with v on empty file; fix bug with v on file with
858                 metachars in name; add --nohistdups option.
859 v532  7/27/18   Redraw screen on SIGWINCH even if screen size doesn't change.
860 v533  8/1/18    Shell escape filenames in history; use PCRE_UTF8 flag;
861                 use wide-chars for Windows console title (thanks to Jason Hood).
862 v534  8/9/18    Support PCRE2.
863 v535  8/16/18   Don't count lines of initial screen if using -X with -F
864                 (thanks to Linus Torvalds).
865 v536  8/31/18   Use descriptive error messages for PCRE2.
866 v537  8/31/18   Support mingw build system (thanks to Mike Soyka).
867 v538  9/3/18    Clean up some WIN32 code.
868 v539  9/13/18   Fix spurious input on Windows with CAPSLOCK.
869 v540  10/29/18  Add --mouse option.
870 v541  10/30/18  Add --MOUSE option.
871 v542  11/6/18   Add mouse support for WIN32; add --wheel-lines option.
872                 (thanks to Jason Hood).
873 v543  11/12/18  Code cleanup.
874 v544  11/16/18  Don't init/deinit keyboard/mouse if quit due to -F.
875 v545  11/22/18  Fix Windows build, memory leaks.
876 v546  11/29/18  Add --save-marks option.
877 v547  11/30/18  Fix some bugs with saved marks.
878 v548  12/14/18  Ignore mouse input when line editing.
879 v549  2/10/19   Support X11 mouse extension 1006;
880                 Win32 fixes (thanks to Jason Hood).
881 v550  2/16/19   Fix Win32 build; don't enable mouse unless --mouse is set.
882 v551  6/10/19   Doc changes.
883 */
884 
885 char version[] = "551";
886