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 ======================================================================
15 Major changes between "less" versions 443 and 444
17 * Fix bug in unget handling that can cause strange effects on the
20 * Remove vestiges of obsolete -l option that can cause a crash.
22 ======================================================================
24 Major changes between "less" versions 436 and 443
26 * Change search behavior such that when a search is given an explicit
27 pattern, the entire displayed screen is included in the search and
28 not just the portion after the target line.
30 * Add -A option to change search behavior to the old way: only
31 the portion of the screen after the target line is searched.
33 * Add %F formatting to prompt strings, replaced by the last component
36 * Control-G while editing a command exits the command.
38 * Less now exits with status 2 if control-C is pressed and -K is in effect.
40 * Fix "ungetc overflow" when passing long commands via the -p option.
42 * Fix bug in using line filtering via the & command
43 in combination with -i and -I.
45 * Fix bug in handling negative arguments to the -j option.
47 * Fix bug in handling %t in prompt strings.
49 * Improve handling of long option names.
51 * Improve percentage calculation for very large files.
53 ======================================================================
55 Major changes between "less" versions 429 and 436
57 * Don't pass "-" to non-pipe LESSOPEN unless it starts with "-".
59 * Allow a fraction as the argument to the -# (--shift) option.
61 * Fix highlight bug when underlined/overstruck text matches at end of line.
63 * Fix non-regex searches with ctrl-R.
65 ======================================================================
67 Major changes between "less" versions 424 and 429
69 * LESSOPEN pipe will now be used on standard input, if the LESSOPEN
70 environment variable begins with "|-".
72 * The -D option with one number now means use the normal background color.
74 * Don't change permissions on history file if it is not a regular file.
76 * Fix non-ANSI-compliant code that caused problems with some compilers.
78 * Fix binary file detection in UTF-8 mode.
80 * Fix display problems with long lines on "ignaw" terminals.
82 * Fix problem interrupting the line number calculation for initial prompt.
84 * Fix SGR emulation when dealing with multiple attributes (eg. bold+underline).
86 * Fix highlight bug when searching for underlined/overstruck text.
88 ======================================================================
90 Major changes between "less" versions 418 and 424
92 * New "&" command allows filtering of lines based on a pattern.
94 * Status column now displays a search match, even if the matched
95 string is scrolled off screen because -S is in effect.
97 * Improve behavior of -F option.
99 * Allow CSI character (0x9B) to work in UTF-8 mode.
101 * Output carriage return at startup in case terminal doesn't default
104 * Fix bug in '' (quote, quote) command after G command.
106 ======================================================================
108 Major changes between "less" versions 416 and 418
110 * Color escape sequences are now supported in WIN32 build.
112 * Makefile now uses EXEEXT feature of autoconf.
114 * Fix search bug when using -R and text contains ANSI color escape sequences.
116 * Fix crash when using -r with UTF-8 text containing 0x9B bytes.
118 * Fix display bug when using ' command to move less than one page forward.
120 * Update GPL to version 3.
122 ======================================================================
124 Major changes between "less" versions 409 and 416
126 * New --follow-name option makes F command follow the name of a file
127 rather than the file descriptor if an open file is renamed.
129 * Make searching with -i/-I work correctly with non-ASCII text.
133 ======================================================================
135 Major changes between "less" versions 406 and 409
137 * Support CSI escape sequences, like SGR escape sequences.
139 * Fix bug which caused screen to fail to repaint when window is resized.
141 * Fix bug in using -i and -I flags with non-ASCII text.
143 * Fix configure bug on systems which don't support langinfo.h.
145 * Fix crash when searching text containing certain invalid UTF-8 sequences.
147 ======================================================================
149 Major changes between "less" versions 394 and 406
151 * Allow decimal point in number for % (percent) command.
153 * Allow decimal point in number for -j option (fraction of screen height).
155 * Make n command fetch previous pattern from history file on first search.
157 * Don't rewrite history file if it has not changed.
159 * Don't move to bottom of screen on first page.
161 * Don't output extraneous newlines, so copy & pasting lines from the
164 * The -c option has been made identical with the -C option.
166 * Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate
167 that no history file should be used.
169 * Search can now find text which follows a null byte, if the PCRE
170 library is used, or if no-regex searching (ctrl-R) is used.
172 * Better compatibility with POSIX more specification.
174 * Make -f work for directories.
176 * Make "t" cmd traverse tags in the correct order.
178 * Allow a few binary characters in the input file before warning
179 that the file is binary.
181 * Don't warn that file is binary if it merely contains ANSI color sequences
184 * Update Unicode character tables.
186 * Support DESTDIR in Makefile.
188 * Fix bug when filename contains certain shell metacharacters such as "$".
190 * Fix bug when resizing the window while waiting for input from a pipe.
192 * Fix configure bugs.
194 ======================================================================
196 Major changes between "less" versions 382 and 394
198 * Add history file to save search and shell command history between
201 * Improve behavior of history list for search and shell commands.
203 * Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C.
205 * Improve handling of UTF-8 files and commands, including better
206 line wrapping and handling double-width chars.
208 * Added LESSUTFBINFMT environment variable to control display of
209 non-printable characters in a UTF-8 file.
211 * Add --with-secure option to configure, to make it easier to
212 build a secure version of less.
214 * Show search matches in the status column even if search highlights
215 are disabled via the -G option or the ESC-u command.
217 * Improve performance when the file contains very long lines.
219 * Add "windows" charset.
221 * Add man page for lessecho.
223 * Add support for erase2 character, treated same as erase.
225 * Use ASCII lowercase/uppercase logic when operating on the command line.
227 * Update makefile for Borland C++ 5.5.1.
229 * Fix bug in calculating number of pages for %D prompt.
231 * Fix bug in handling tag file error.
233 * Fix obscure bug if input file is deleted while viewing help.
235 * Fix bug handling filenames which include square brackets.
237 * Fix possible buffer overflow in "global" tag search.
239 * Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE.
241 * Fix buffer overflow in reverse search.
243 ======================================================================
245 Major changes between "less" versions 381 and 382
247 * Removed some old copyrighted code.
248 This probably breaks OS/9 support.
250 ======================================================================
252 Major changes between "less" versions 378 and 381
254 * New -L option to disable LESSOPEN processing.
256 * Further support for large (64 bit) file addressing.
257 Large file support is now set up by the configure script.
260 Replace configure.in, acconfig.h, defines.h.top with configure.ac.
262 * Overstriking underscore with underscore is now bold or underlined
263 depending on context.
265 * Use only 7 spaces for line numbers in -N mode, if possible.
267 * Fix some bugs in handling overstriking in UTF-8 files.
269 * Fix some nroff issues in the man page.
271 ======================================================================
273 Major changes between "less" versions 376 and 378
276 Default buffer space is now 64K as documented.
277 Search highlighting works properly when used with -R.
278 Windows version works properly when input file contains carriage returns.
279 Clean up some compiler warnings.
281 ======================================================================
283 Major changes between "less" versions 358 and 376
285 * -x option can now specify multiple variable-width tab stops.
287 * -X option no longer disables keypad initialization.
288 New option --no-keypad disables keypad initialization.
290 * New commands t and T step through multiple tag matches.
291 Added support for "global(1)" tags
292 (see http://www.gnu.org/software/global/global.html).
294 * New prompt style set by option -Pw defines the message printed
295 while waiting for data in the F command.
297 * System-wide lesskey file now defaults to sysless in etc directory
298 instead of .sysless in bin directory.
299 Use "configure --sysconfdir=..." to change it.
300 (For backwards compatibility, .sysless in bin is still recognized.)
302 * Pressing RightArrow or LeftArrow while entering a number now shifts
303 the display N columns rather than editing the number itself.
305 * Status column (enabled with -J) now shows search results.
307 * Windows version sets window title.
309 * Default LESSCHARSET for MS-DOS versions is now "dos".
311 * Searching works better with ANSI (SGR) escape sequences.
312 ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version.
314 * Improved performance in reading very large pipes.
316 * Eliminated some dependencies on file offets being 32 bits.
318 * Fixed problems when viewing files with very long lines.
320 * Fixed overstriking in UTF-8 mode, and overstriking tabs.
322 * Improved horizontal shifting of text using -R option with ANSI color.
324 * Improved handling of filenames containing shell metacharacters.
326 * Some fixes for EBCDIC systems.
328 * Some fixes for OS/2 systems.
330 ======================================================================
332 Major changes between "less" versions 354 and 358
334 * Add -J (--status-column) option to display a status column.
336 * Add -# (--shift) option to set default horizontal shift distance.
337 Default horizontal shift distance is now one-half screen width.
339 * Horizontal shifting does not shift line numbers if -N is in effect.
341 * Horizontal shifting acts as though -S were set, to avoid confusion.
343 ======================================================================
346 Major changes between "less" versions 352 and 354
348 * Allow space after numeric-valued command line options.
350 * Fix problem with configuring terminal libraries on some systems.
352 * Add support for PCRE regular expression library.
354 * Add --with-regex option to configure to allow manually selecting
355 a regular expression library.
357 * Fix bug compiling with SECURE = 1.
359 ======================================================================
362 Major changes between "less" versions 346 and 352
364 * Enable UTF-8 if "UTF-8" appears in locale-related environment variables.
366 * Add --with-editor option to configure script.
368 * The -M prompt and = message now show the top and bottom line number.
370 * Fix bug in running the editor on a file whose name contains quotes, etc.
372 * Fix bug in horizontal scrolling of long lines.
374 * Fix bug in doing :d on a file which contains marks.
376 * Fix bug causing cleared lines to sometimes be filled with standout,
377 bold, underline, etc. on certain terminals.
379 * Fixes for MS-DOS (DJGPP) version.
381 ======================================================================
384 Major changes between "less" versions 340 and 346
386 * The UTF-8 character set is now supported.
388 * The default character set is now latin1 rather than ascii.
390 * New option -R (--RAW-CONTROL-CHARS) is like -r but handles
391 long (wrapped) lines correctly, as long as the input contains only
392 normal text and ANSI color escape sequences.
394 * New option -F (--quit-if-one-screen) quits if the text fits on
397 * The -w option now highlights the target line of a g or p command.
399 * A system-wide lesskey file is supported (LESSKEY_SYSTEM).
401 * New escape for prompt strings: %c is replaced by column number.
403 * New escape for prompt strings: %P is replaced by percentage into
404 file, based on line number rather than byte offset.
406 * HOME and END keys now jump to beginning of file or end of file.
408 ======================================================================
411 Major changes between "less" versions 337 and 340
413 * Command line options for less may now be given in either the old
414 single-letter form, or a new long name form (--option-name).
415 See the less man page or "less --help" for the list of long option names.
417 * Command line options for lesskey may now be given in a new long name
418 form. See the lesskey man page for the list of long option names.
420 * New command -- toggles an option using the long option name.
422 * New command __ queries an option using the long option name.
424 * The old -- command is renamed as -!.
426 * If a ^P is entered between the dash and the option letter of the -
427 command, the message describing the new setting is suppressed.
429 * Lesskey files may now contain \k escape sequences to represent the
430 "special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE).
432 * New command :d removes the current file from the list of files.
434 * New option -~ (like -w before version 335)
435 suppresses tildes after end-of-file.
437 * Less is now released under the GNU General Public License.
439 ======================================================================
442 Major changes between "less" versions 335 and 337
444 * Fixed bugs in "make install".
446 ======================================================================
449 Major changes between "less" versions 332 and 335
451 * The old -w flag (suppress tildes after end-of-file) has been removed.
453 * New -w flag highlights the first new line after a forward-screen.
455 * New -W flag highlights the first new line after any forward movement.
457 * Window resize works even if LINES and/or COLUMNS environment
458 variables are incorrect.
460 * New percent escapes for prompt strings:
461 %d is replaced by the page number, and
462 %D is replaced by the number of pages in the file.
464 * Added charsets "iso8859" and "ebcdic".
466 * In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined.
468 * Fixed some bugs causing incorrect display on DOS/Windows.
470 ======================================================================
473 Major changes between "less" versions 330 and 332
475 * Filenames from the command line are entered into the command history,
476 so UPARROW/DOWNARROW can be used to retrieve them from the :e command.
478 * Now works correctly on Windows when using a scrolling terminal
479 window (buffer larger than display window).
481 * On Windows, now restores the console screen on exit.
482 Use -X to get the old behavior.
484 * Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed.
486 * Fixed bug on Windows when piping output of an interactive program.
488 * Fixed bug in tags file processing when tags file has DOS-style
489 line terminators (CR/LF).
491 * Fixed compilation problem on OS/2.
493 ======================================================================
496 Major changes between "less" versions 321 and 330
498 * Now supports filenames containing spaces (in double quotes).
499 New option -" can be used to change the quoting characters.
501 * In filename completion, a slash is appended to a directory name.
502 If the environment variable LESSSEPARATOR is set, the value of
503 that variable, rather than a slash, is appended.
505 * LeftArrow and RightArrow are same as ESC-[ and ESC-].
507 * Added commands ESC-( and ESC-), same as ESC-[ and ESC-].
509 * A "quit" command defined in a lesskey file may now have an "extra"
510 string, which is used to return an exit code from less when it quits.
512 * New environment variables LESSMETACHARS and LESSMETAESCAPE provide
513 more control over how less interfaces to the shell.
515 * Ported to Microsoft Visual C compiler for Windows.
517 * Ported to DJGPP compiler for MS-DOS.
521 ======================================================================
524 Major changes between "less" versions 291 and 321
526 * Command line at bottom of screen now scrolls, so it can be longer
527 than the screen width.
529 * New commands ESC-] and ESC-[ scroll the display horizontally.
531 * New command ESC-SPACE scrolls forward a full screen, even if it
534 * Alternate modifiers for search commands: ^N is same as !,
535 ^F is same as @, and ^E is same as *.
537 * New modifier for search commands: ^K means highlight the matches
538 currently on-screen, but don't move to the first match.
540 * New modifier for search commands: ^R means don't use regular
541 expressions in the search.
543 * Environment variable LESSKEY gives name of default lesskey file.
545 * Environment variable LESSSECURE will force less to run in
548 * Command line argument "--" signals that the rest of the arguments
549 are files (not option flags).
551 * Help file (less.hlp) is no longer installed. Help text is now
552 embedded in the less executable itself.
554 * Added -Ph to change the prompt for the help text.
555 Added -Ps to change the default short prompt (same as plain -P).
557 * Ported to the Borland C compiler for MS-DOS.
559 * Ported to Windows 95 & Windows NT.
563 * Ported to GNU Hurd.
565 ======================================================================
568 Major changes between "less" versions 290 and 291
570 * Less environment variables can be specified in lesskey files.
572 * Fixed MS-DOS build.
574 ======================================================================
577 Major changes between "less" versions 278 and 290
579 * Accepts GNU-style options "--help" and "--version".
581 * OS/2 version looks for less.ini in $HOME before $INIT and $PATH.
585 ======================================================================
588 Major changes between "less" versions 252 and 278
590 * A LESSOPEN preprocessor may now pipe the converted file data to less,
591 rather than writing it to a temporary file.
593 * Search pattern highlighting has been fixed. It now highlights
594 reliably, even if a string is split across two screen lines,
597 * The -F flag (which suppress search highlighting) has been changed
598 to -G. A new flag, -g, changes search highlighting to highlight
599 only the string found by the last search command, instead of all
600 strings which match the last search command.
602 * New flag -I acts like -i, but ignores case even if the search
603 pattern contains uppercase letters.
605 * Less now checks for the environment variable VISUAL before EDITOR.
609 ======================================================================
612 Major changes between "less" versions 237 and 252
614 * Changes in line-editing keys:
615 The literal key is now ^V or ^A rather than \ (backslash).
616 Filename completion commands (TAB and ^L) are disabled
617 when typing a search pattern.
619 * Line-editing command keys can be redefined using lesskey.
621 * Lesskey with no input file defaults to $HOME/.lesskey
622 rather than standard input.
624 * New option -V displays version number of less.
626 * New option -V displays version number of lesskey.
628 * Help file less.hlp is now installed by default in /usr/local/share
629 rather than /usr/local/lib.
632 ======================================================================
635 Major changes between "less" versions 170 and 237
637 * By popular demand, text which matches the current search pattern
638 is highlighted. New -F flag disables this feature.
640 * Henry Spencer's regexp.c is now included, for systems which do not
641 have a regular expression library.
642 regexp.c is Copyright (c) 1986 by University of Toronto.
644 * New line-editing keys, including command history (arrow keys) and
645 filename completion (TAB).
647 * Input preprocessor allows modification of input files (e.g. uncompress)
648 via LESSOPEN/LESSCLOSE environment variables.
650 * New -X flag disables sending termcap "ti" and "te" (initialize and
651 deinitialize) strings to the terminal.
653 * Changing -i from within less now correctly affects a subsequent
656 * Searching for underlined or overstruck text now works when the -u
657 flag is in effect, rather than the -i flag.
659 * Use setlocale (LANG and LC_CTYPE environment variables) to determine
660 the character set if LESSCHARSET/LESSCHARDEF are not set.
662 * The default format for displaying binary characters is now standout
663 (reverse video) rather than blinking. This can still be changed by
664 setting the LESSBINFMT environment variable.
666 * Use autoconf installation technology.
670 ********************************
671 Things that may surprise you
672 ********************************
674 * When you enter text at the bottom of the screen (search string,
675 filename, etc.), some keys act different than previously.
676 Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L
677 now have line editing functions.
679 * Some previous unofficial versions of less were able to display
680 compressed files. The new LESSOPEN/LESSCLOSE feature now provides
681 this functionality in a different way.
683 * Some previous unofficial versions of less provided a -Z flag to
684 set the number of lines of text to retain between full screen scrolls.
685 The -z-n flag (that is, -z with a negative number) provides this
689 ======================================================================
692 Major changes between "less" versions 123 and 170
694 * New option -j allows target lines to be positioned anywhere on screen.
696 * New option -S truncates displayed line at the screen width,
697 rather than wrapping onto the next line.
699 * New option -y limits amount of forward scroll.
701 * New option -T specifies a "tags" file.
703 * Non-printable, non-control characters are displayed in octal.
704 Such characters, as well as control characters, are displayed
707 * New command -+ sets an option to its default.
708 * New command -- sets an option to the opposite of its default.
710 * Lesskey file may have a string appended to a key's action,
711 which acts as though typed in after the command.
713 * New commands ESC-^F and ESC-^B match arbitrary types of brackets.
715 * New command F monitors a growing file (like "tail -f").
717 * New command | pipes a section of the input file into a shell command.
719 * New command :x directly jumps to a file in the command line list.
721 * Search commands have been enhanced and reorganized:
722 n Repeat search, same direction.
723 N Repeat search, opposite direction.
724 ESC-/ Search forward thru file boundaries
725 ESC-? Search backward thru file boundaries
726 ESC-n Repeat search thru file boundaries, same direction.
727 ESC-N Repeat search thru file boundaries, opposite direction.
728 Special character * causes search to search thru file boundaries.
729 Special character @ causes search to begin at start/end of file list.
731 * Examining a new file adds it to the command line list.
732 A list of files, or an expression which matches more than one file,
733 may be examined; all of them are added to the command line list.
735 * Environment variables LESSCHARSET and LESSCHARDEF can define
736 a non-ASCII character set.
738 * Partial support for MSDOS, including options -R for repainting screen
739 on quit, -v/-V to select video mode, and -W to change window size.
742 ======================================================================
745 Major changes between "less" versions 97 and 123
747 * New option (-N) causes line numbers to be displayed in the
748 text of the file (like vi "set nu").
750 * New option (-?) prints help message immediately.
752 * New option (-r) displays "raw" control characters, without
753 mapping them to ^X notation.
755 * New option (-f) forces less to open non-regular files
758 * New option (-k) can be used to specify lesskey files by name.
760 * New option (-y) can be used to set a forward scroll limit
761 (like -h sets a backward scroll limit).
763 * File marks (set by the m command) are now preserved when a new
764 file is edited. The ' command can thus be used to switch files.
766 * New command ESC-/ searches all files (on the command line)
769 * New command ESC-n repeats previous search, spanning files.
771 * The N command has been changed to repeat the previous search
772 in the reverse direction. The old N command is still available
775 * New command ESC-N repeats previous search in the reverse
776 direction and spanning files.
778 * 8 bit characters are now supported. A new option (-g) can be
779 used to strip off the eighth bit (the previous behavior).
781 * Options which take a following string (like -t) may now
782 optionally have a space between the option letter and the string.
784 * Six new commands { } ( ) [ and ] can be used to match
785 brackets of specific types, similar to vi % command.
787 * New commands z and w move forward/backward one window and
788 simultaneously set the window size.
790 * Prompt string expansion now has %L for line number of the last
791 line in the file, and %E for the name of the editor.
792 Also, % escapes which refer to a line (b=bottom, t=top, etc.)
793 can use j for the jump target line.
795 * New environment variable LESSEDIT can be used to tailor the
796 command string passed to the editor by the v command.
798 * Examining a file which was previously examined will return
799 to the same position in the file.
801 * A "%" is expanded to the current filename and a "#" to the
802 previous filename, in both shell commands and the E command.
803 (Previously % worked only in shell commands and # worked
804 only in the E command.)
806 * New command ":ta" is equivalent to "-t".
808 * New command "s" is equivalent to "-l".
810 * The - command may be followed by "+X" to revert to the default
811 for option X, or "-X" to get the opposite of the default.
813 * Lesskey files may now include characters after the action as
814 extra input to be parsed after the action; for example:
815 "toggle-option X" to toggle a specific option X.