4 ======================================================================
6 For the latest news about less, see the "less" Web page:
7 http://www.greenwoodsoftware.com/less
8 You can also download the latest version of less from there.
10 To report bugs, suggestions or comments, send email to
11 bug-less@gnu.org or markn@greenwoodsoftware.com.
13 ======================================================================
16 Major changes between "less" versions 406 and 409
18 * Support CSI escape sequences, like SGR escape sequences.
20 * Fix bug which caused screen to fail to repaint when window is resized.
22 * Fix bug in using -i and -I flags with non-ASCII text.
24 * Fix configure bug on systems which don't support langinfo.h.
26 * Fix crash when searching text containing certain invalid UTF-8 sequences.
28 ======================================================================
30 Major changes between "less" versions 394 and 406
32 * Allow decimal point in number for % (percent) command.
34 * Allow decimal point in number for -j option (fraction of screen height).
36 * Make n command fetch previous pattern from history file on first search.
38 * Don't rewrite history file if it has not changed.
40 * Don't move to bottom of screen on first page.
42 * Don't output extraneous newlines, so copy & pasting lines from the
45 * The -c option has been made identical with the -C option.
47 * Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate
48 that no history file should be used.
50 * Search can now find text which follows a null byte, if the PCRE
51 library is used, or if no-regex searching (ctrl-R) is used.
53 * Better compatibility with POSIX more specification.
55 * Make -f work for directories.
57 * Make "t" cmd traverse tags in the correct order.
59 * Allow a few binary characters in the input file before warning
60 that the file is binary.
62 * Don't warn that file is binary if it merely contains ANSI color sequences
65 * Update Unicode character tables.
67 * Support DESTDIR in Makefile.
69 * Fix bug when filename contains certain shell metacharacters such as "$".
71 * Fix bug when resizing the window while waiting for input from a pipe.
75 ======================================================================
77 Major changes between "less" versions 382 and 394
79 * Add history file to save search and shell command history between
82 * Improve behavior of history list for search and shell commands.
84 * Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C.
86 * Improve handling of UTF-8 files and commands, including better
87 line wrapping and handling double-width chars.
89 * Added LESSUTFBINFMT environment variable to control display of
90 non-printable characters in a UTF-8 file.
92 * Add --with-secure option to configure, to make it easier to
93 build a secure version of less.
95 * Show search matches in the status column even if search highlights
96 are disabled via the -G option or the ESC-u command.
98 * Improve performance when the file contains very long lines.
100 * Add "windows" charset.
102 * Add man page for lessecho.
104 * Add support for erase2 character, treated same as erase.
106 * Use ASCII lowercase/uppercase logic when operating on the command line.
108 * Update makefile for Borland C++ 5.5.1.
110 * Fix bug in calculating number of pages for %D prompt.
112 * Fix bug in handling tag file error.
114 * Fix obscure bug if input file is deleted while viewing help.
116 * Fix bug handling filenames which include square brackets.
118 * Fix possible buffer overflow in "global" tag search.
120 * Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE.
122 * Fix buffer overflow in reverse search.
124 ======================================================================
126 Major changes between "less" versions 381 and 382
128 * Removed some old copyrighted code.
129 This probably breaks OS/9 support.
131 ======================================================================
133 Major changes between "less" versions 378 and 381
135 * New -L option to disable LESSOPEN processing.
137 * Further support for large (64 bit) file addressing.
138 Large file support is now set up by the configure script.
141 Replace configure.in, acconfig.h, defines.h.top with configure.ac.
143 * Overstriking underscore with underscore is now bold or underlined
144 depending on context.
146 * Use only 7 spaces for line numbers in -N mode, if possible.
148 * Fix some bugs in handling overstriking in UTF-8 files.
150 * Fix some nroff issues in the man page.
152 ======================================================================
154 Major changes between "less" versions 376 and 378
157 Default buffer space is now 64K as documented.
158 Search highlighting works properly when used with -R.
159 Windows version works properly when input file contains carriage returns.
160 Clean up some compiler warnings.
162 ======================================================================
164 Major changes between "less" versions 358 and 376
166 * -x option can now specify multiple variable-width tab stops.
168 * -X option no longer disables keypad initialization.
169 New option --no-keypad disables keypad initialization.
171 * New commands t and T step through multiple tag matches.
172 Added support for "global(1)" tags
173 (see http://www.gnu.org/software/global/global.html).
175 * New prompt style set by option -Pw defines the message printed
176 while waiting for data in the F command.
178 * System-wide lesskey file now defaults to sysless in etc directory
179 instead of .sysless in bin directory.
180 Use "configure --sysconfdir=..." to change it.
181 (For backwards compatibility, .sysless in bin is still recognized.)
183 * Pressing RightArrow or LeftArrow while entering a number now shifts
184 the display N columns rather than editing the number itself.
186 * Status column (enabled with -J) now shows search results.
188 * Windows version sets window title.
190 * Default LESSCHARSET for MS-DOS versions is now "dos".
192 * Searching works better with ANSI (SGR) escape sequences.
193 ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version.
195 * Improved performance in reading very large pipes.
197 * Eliminated some dependencies on file offets being 32 bits.
199 * Fixed problems when viewing files with very long lines.
201 * Fixed overstriking in UTF-8 mode, and overstriking tabs.
203 * Improved horizontal shifting of text using -R option with ANSI color.
205 * Improved handling of filenames containing shell metacharacters.
207 * Some fixes for EBCDIC systems.
209 * Some fixes for OS/2 systems.
211 ======================================================================
213 Major changes between "less" versions 354 and 358
215 * Add -J (--status-column) option to display a status column.
217 * Add -# (--shift) option to set default horizontal shift distance.
218 Default horizontal shift distance is now one-half screen width.
220 * Horizontal shifting does not shift line numbers if -N is in effect.
222 * Horizontal shifting acts as though -S were set, to avoid confusion.
224 ======================================================================
227 Major changes between "less" versions 352 and 354
229 * Allow space after numeric-valued command line options.
231 * Fix problem with configuring terminal libraries on some systems.
233 * Add support for PCRE regular expression library.
235 * Add --with-regex option to configure to allow manually selecting
236 a regular expression library.
238 * Fix bug compiling with SECURE = 1.
240 ======================================================================
243 Major changes between "less" versions 346 and 352
245 * Enable UTF-8 if "UTF-8" appears in locale-related environment variables.
247 * Add --with-editor option to configure script.
249 * The -M prompt and = message now show the top and bottom line number.
251 * Fix bug in running the editor on a file whose name contains quotes, etc.
253 * Fix bug in horizontal scrolling of long lines.
255 * Fix bug in doing :d on a file which contains marks.
257 * Fix bug causing cleared lines to sometimes be filled with standout,
258 bold, underline, etc. on certain terminals.
260 * Fixes for MS-DOS (DJGPP) version.
262 ======================================================================
265 Major changes between "less" versions 340 and 346
267 * The UTF-8 character set is now supported.
269 * The default character set is now latin1 rather than ascii.
271 * New option -R (--RAW-CONTROL-CHARS) is like -r but handles
272 long (wrapped) lines correctly, as long as the input contains only
273 normal text and ANSI color escape sequences.
275 * New option -F (--quit-if-one-screen) quits if the text fits on
278 * The -w option now highlights the target line of a g or p command.
280 * A system-wide lesskey file is supported (LESSKEY_SYSTEM).
282 * New escape for prompt strings: %c is replaced by column number.
284 * New escape for prompt strings: %P is replaced by percentage into
285 file, based on line number rather than byte offset.
287 * HOME and END keys now jump to beginning of file or end of file.
289 ======================================================================
292 Major changes between "less" versions 337 and 340
294 * Command line options for less may now be given in either the old
295 single-letter form, or a new long name form (--option-name).
296 See the less man page or "less --help" for the list of long option names.
298 * Command line options for lesskey may now be given in a new long name
299 form. See the lesskey man page for the list of long option names.
301 * New command -- toggles an option using the long option name.
303 * New command __ queries an option using the long option name.
305 * The old -- command is renamed as -!.
307 * If a ^P is entered between the dash and the option letter of the -
308 command, the message describing the new setting is suppressed.
310 * Lesskey files may now contain \k escape sequences to represent the
311 "special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE).
313 * New command :d removes the current file from the list of files.
315 * New option -~ (like -w before version 335)
316 suppresses tildes after end-of-file.
318 * Less is now released under the GNU General Public License.
320 ======================================================================
323 Major changes between "less" versions 335 and 337
325 * Fixed bugs in "make install".
327 ======================================================================
330 Major changes between "less" versions 332 and 335
332 * The old -w flag (suppress tildes after end-of-file) has been removed.
334 * New -w flag highlights the first new line after a forward-screen.
336 * New -W flag highlights the first new line after any forward movement.
338 * Window resize works even if LINES and/or COLUMNS environment
339 variables are incorrect.
341 * New percent escapes for prompt strings:
342 %d is replaced by the page number, and
343 %D is replaced by the number of pages in the file.
345 * Added charsets "iso8859" and "ebcdic".
347 * In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined.
349 * Fixed some bugs causing incorrect display on DOS/Windows.
351 ======================================================================
354 Major changes between "less" versions 330 and 332
356 * Filenames from the command line are entered into the command history,
357 so UPARROW/DOWNARROW can be used to retrieve them from the :e command.
359 * Now works correctly on Windows when using a scrolling terminal
360 window (buffer larger than display window).
362 * On Windows, now restores the console screen on exit.
363 Use -X to get the old behavior.
365 * Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed.
367 * Fixed bug on Windows when piping output of an interactive program.
369 * Fixed bug in tags file processing when tags file has DOS-style
370 line terminators (CR/LF).
372 * Fixed compilation problem on OS/2.
374 ======================================================================
377 Major changes between "less" versions 321 and 330
379 * Now supports filenames containing spaces (in double quotes).
380 New option -" can be used to change the quoting characters.
382 * In filename completion, a slash is appended to a directory name.
383 If the environment variable LESSSEPARATOR is set, the value of
384 that variable, rather than a slash, is appended.
386 * LeftArrow and RightArrow are same as ESC-[ and ESC-].
388 * Added commands ESC-( and ESC-), same as ESC-[ and ESC-].
390 * A "quit" command defined in a lesskey file may now have an "extra"
391 string, which is used to return an exit code from less when it quits.
393 * New environment variables LESSMETACHARS and LESSMETAESCAPE provide
394 more control over how less interfaces to the shell.
396 * Ported to Microsoft Visual C compiler for Windows.
398 * Ported to DJGPP compiler for MS-DOS.
402 ======================================================================
405 Major changes between "less" versions 291 and 321
407 * Command line at bottom of screen now scrolls, so it can be longer
408 than the screen width.
410 * New commands ESC-] and ESC-[ scroll the display horizontally.
412 * New command ESC-SPACE scrolls forward a full screen, even if it
415 * Alternate modifiers for search commands: ^N is same as !,
416 ^F is same as @, and ^E is same as *.
418 * New modifier for search commands: ^K means highlight the matches
419 currently on-screen, but don't move to the first match.
421 * New modifier for search commands: ^R means don't use regular
422 expressions in the search.
424 * Environment variable LESSKEY gives name of default lesskey file.
426 * Environment variable LESSSECURE will force less to run in
429 * Command line argument "--" signals that the rest of the arguments
430 are files (not option flags).
432 * Help file (less.hlp) is no longer installed. Help text is now
433 embedded in the less executable itself.
435 * Added -Ph to change the prompt for the help text.
436 Added -Ps to change the default short prompt (same as plain -P).
438 * Ported to the Borland C compiler for MS-DOS.
440 * Ported to Windows 95 & Windows NT.
444 * Ported to GNU Hurd.
446 ======================================================================
449 Major changes between "less" versions 290 and 291
451 * Less environment variables can be specified in lesskey files.
453 * Fixed MS-DOS build.
455 ======================================================================
458 Major changes between "less" versions 278 and 290
460 * Accepts GNU-style options "--help" and "--version".
462 * OS/2 version looks for less.ini in $HOME before $INIT and $PATH.
466 ======================================================================
469 Major changes between "less" versions 252 and 278
471 * A LESSOPEN preprocessor may now pipe the converted file data to less,
472 rather than writing it to a temporary file.
474 * Search pattern highlighting has been fixed. It now highlights
475 reliably, even if a string is split across two screen lines,
478 * The -F flag (which suppress search highlighting) has been changed
479 to -G. A new flag, -g, changes search highlighting to highlight
480 only the string found by the last search command, instead of all
481 strings which match the last search command.
483 * New flag -I acts like -i, but ignores case even if the search
484 pattern contains uppercase letters.
486 * Less now checks for the environment variable VISUAL before EDITOR.
490 ======================================================================
493 Major changes between "less" versions 237 and 252
495 * Changes in line-editing keys:
496 The literal key is now ^V or ^A rather than \ (backslash).
497 Filename completion commands (TAB and ^L) are disabled
498 when typing a search pattern.
500 * Line-editing command keys can be redefined using lesskey.
502 * Lesskey with no input file defaults to $HOME/.lesskey
503 rather than standard input.
505 * New option -V displays version number of less.
507 * New option -V displays version number of lesskey.
509 * Help file less.hlp is now installed by default in /usr/local/share
510 rather than /usr/local/lib.
513 ======================================================================
516 Major changes between "less" versions 170 and 237
518 * By popular demand, text which matches the current search pattern
519 is highlighted. New -F flag disables this feature.
521 * Henry Spencer's regexp.c is now included, for systems which do not
522 have a regular expression library.
523 regexp.c is Copyright (c) 1986 by University of Toronto.
525 * New line-editing keys, including command history (arrow keys) and
526 filename completion (TAB).
528 * Input preprocessor allows modification of input files (e.g. uncompress)
529 via LESSOPEN/LESSCLOSE environment variables.
531 * New -X flag disables sending termcap "ti" and "te" (initialize and
532 deinitialize) strings to the terminal.
534 * Changing -i from within less now correctly affects a subsequent
537 * Searching for underlined or overstruck text now works when the -u
538 flag is in effect, rather than the -i flag.
540 * Use setlocale (LANG and LC_CTYPE environment variables) to determine
541 the character set if LESSCHARSET/LESSCHARDEF are not set.
543 * The default format for displaying binary characters is now standout
544 (reverse video) rather than blinking. This can still be changed by
545 setting the LESSBINFMT environment variable.
547 * Use autoconf installation technology.
551 ********************************
552 Things that may surprise you
553 ********************************
555 * When you enter text at the bottom of the screen (search string,
556 filename, etc.), some keys act different than previously.
557 Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L
558 now have line editing functions.
560 * Some previous unofficial versions of less were able to display
561 compressed files. The new LESSOPEN/LESSCLOSE feature now provides
562 this functionality in a different way.
564 * Some previous unofficial versions of less provided a -Z flag to
565 set the number of lines of text to retain between full screen scrolls.
566 The -z-n flag (that is, -z with a negative number) provides this
570 ======================================================================
573 Major changes between "less" versions 123 and 170
575 * New option -j allows target lines to be positioned anywhere on screen.
577 * New option -S truncates displayed line at the screen width,
578 rather than wrapping onto the next line.
580 * New option -y limits amount of forward scroll.
582 * New option -T specifies a "tags" file.
584 * Non-printable, non-control characters are displayed in octal.
585 Such characters, as well as control characters, are displayed
588 * New command -+ sets an option to its default.
589 * New command -- sets an option to the opposite of its default.
591 * Lesskey file may have a string appended to a key's action,
592 which acts as though typed in after the command.
594 * New commands ESC-^F and ESC-^B match arbitrary types of brackets.
596 * New command F monitors a growing file (like "tail -f").
598 * New command | pipes a section of the input file into a shell command.
600 * New command :x directly jumps to a file in the command line list.
602 * Search commands have been enhanced and reorganized:
603 n Repeat search, same direction.
604 N Repeat search, opposite direction.
605 ESC-/ Search forward thru file boundaries
606 ESC-? Search backward thru file boundaries
607 ESC-n Repeat search thru file boundaries, same direction.
608 ESC-N Repeat search thru file boundaries, opposite direction.
609 Special character * causes search to search thru file boundaries.
610 Special character @ causes search to begin at start/end of file list.
612 * Examining a new file adds it to the command line list.
613 A list of files, or an expression which matches more than one file,
614 may be examined; all of them are added to the command line list.
616 * Environment variables LESSCHARSET and LESSCHARDEF can define
617 a non-ASCII character set.
619 * Partial support for MSDOS, including options -R for repainting screen
620 on quit, -v/-V to select video mode, and -W to change window size.
623 ======================================================================
626 Major changes between "less" versions 97 and 123
628 * New option (-N) causes line numbers to be displayed in the
629 text of the file (like vi "set nu").
631 * New option (-?) prints help message immediately.
633 * New option (-r) displays "raw" control characters, without
634 mapping them to ^X notation.
636 * New option (-f) forces less to open non-regular files
639 * New option (-k) can be used to specify lesskey files by name.
641 * New option (-y) can be used to set a forward scroll limit
642 (like -h sets a backward scroll limit).
644 * File marks (set by the m command) are now preserved when a new
645 file is edited. The ' command can thus be used to switch files.
647 * New command ESC-/ searches all files (on the command line)
650 * New command ESC-n repeats previous search, spanning files.
652 * The N command has been changed to repeat the previous search
653 in the reverse direction. The old N command is still available
656 * New command ESC-N repeats previous search in the reverse
657 direction and spanning files.
659 * 8 bit characters are now supported. A new option (-g) can be
660 used to strip off the eighth bit (the previous behavior).
662 * Options which take a following string (like -t) may now
663 optionally have a space between the option letter and the string.
665 * Six new commands { } ( ) [ and ] can be used to match
666 brackets of specific types, similar to vi % command.
668 * New commands z and w move forward/backward one window and
669 simultaneously set the window size.
671 * Prompt string expansion now has %L for line number of the last
672 line in the file, and %E for the name of the editor.
673 Also, % escapes which refer to a line (b=bottom, t=top, etc.)
674 can use j for the jump target line.
676 * New environment variable LESSEDIT can be used to tailor the
677 command string passed to the editor by the v command.
679 * Examining a file which was previously examined will return
680 to the same position in the file.
682 * A "%" is expanded to the current filename and a "#" to the
683 previous filename, in both shell commands and the E command.
684 (Previously % worked only in shell commands and # worked
685 only in the E command.)
687 * New command ":ta" is equivalent to "-t".
689 * New command "s" is equivalent to "-l".
691 * The - command may be followed by "+X" to revert to the default
692 for option X, or "-X" to get the opposite of the default.
694 * Lesskey files may now include characters after the action as
695 extra input to be parsed after the action; for example:
696 "toggle-option X" to toggle a specific option X.