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 424 and 429
17 * LESSOPEN pipe will now be used on standard input, if the LESSOPEN
18 environment variable begins with "|-".
20 * The -D option with one number now means use the normal background color.
22 * Don't change permissions on history file if it is not a regular file.
24 * Fix non-ANSI-compliant code that caused problems with some compilers.
26 * Fix binary file detection in UTF-8 mode.
28 * Fix display problems with long lines on "ignaw" terminals.
30 * Fix problem interrupting the line number calculation for initial prompt.
32 * Fix SGR emulation when dealing with multiple attributes (eg. bold+underline).
34 * Fix highlight bug when searching for underlined/overstruck text.
36 ======================================================================
38 Major changes between "less" versions 418 and 424
40 * New "&" command allows filtering of lines based on a pattern.
42 * Status column now displays a search match, even if the matched
43 string is scrolled off screen because -S is in effect.
45 * Improve behavior of -F option.
47 * Allow CSI character (0x9B) to work in UTF-8 mode.
49 * Output carriage return at startup in case terminal doesn't default
52 * Fix bug in '' (quote, quote) command after G command.
54 ======================================================================
56 Major changes between "less" versions 416 and 418
58 * Color escape sequences are now supported in WIN32 build.
60 * Makefile now uses EXEEXT feature of autoconf.
62 * Fix search bug when using -R and text contains ANSI color escape sequences.
64 * Fix crash when using -r with UTF-8 text containing 0x9B bytes.
66 * Fix display bug when using ' command to move less than one page forward.
68 * Update GPL to version 3.
70 ======================================================================
72 Major changes between "less" versions 409 and 416
74 * New --follow-name option makes F command follow the name of a file
75 rather than the file descriptor if an open file is renamed.
77 * Make searching with -i/-I work correctly with non-ASCII text.
81 ======================================================================
83 Major changes between "less" versions 406 and 409
85 * Support CSI escape sequences, like SGR escape sequences.
87 * Fix bug which caused screen to fail to repaint when window is resized.
89 * Fix bug in using -i and -I flags with non-ASCII text.
91 * Fix configure bug on systems which don't support langinfo.h.
93 * Fix crash when searching text containing certain invalid UTF-8 sequences.
95 ======================================================================
97 Major changes between "less" versions 394 and 406
99 * Allow decimal point in number for % (percent) command.
101 * Allow decimal point in number for -j option (fraction of screen height).
103 * Make n command fetch previous pattern from history file on first search.
105 * Don't rewrite history file if it has not changed.
107 * Don't move to bottom of screen on first page.
109 * Don't output extraneous newlines, so copy & pasting lines from the
112 * The -c option has been made identical with the -C option.
114 * Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate
115 that no history file should be used.
117 * Search can now find text which follows a null byte, if the PCRE
118 library is used, or if no-regex searching (ctrl-R) is used.
120 * Better compatibility with POSIX more specification.
122 * Make -f work for directories.
124 * Make "t" cmd traverse tags in the correct order.
126 * Allow a few binary characters in the input file before warning
127 that the file is binary.
129 * Don't warn that file is binary if it merely contains ANSI color sequences
132 * Update Unicode character tables.
134 * Support DESTDIR in Makefile.
136 * Fix bug when filename contains certain shell metacharacters such as "$".
138 * Fix bug when resizing the window while waiting for input from a pipe.
140 * Fix configure bugs.
142 ======================================================================
144 Major changes between "less" versions 382 and 394
146 * Add history file to save search and shell command history between
149 * Improve behavior of history list for search and shell commands.
151 * Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C.
153 * Improve handling of UTF-8 files and commands, including better
154 line wrapping and handling double-width chars.
156 * Added LESSUTFBINFMT environment variable to control display of
157 non-printable characters in a UTF-8 file.
159 * Add --with-secure option to configure, to make it easier to
160 build a secure version of less.
162 * Show search matches in the status column even if search highlights
163 are disabled via the -G option or the ESC-u command.
165 * Improve performance when the file contains very long lines.
167 * Add "windows" charset.
169 * Add man page for lessecho.
171 * Add support for erase2 character, treated same as erase.
173 * Use ASCII lowercase/uppercase logic when operating on the command line.
175 * Update makefile for Borland C++ 5.5.1.
177 * Fix bug in calculating number of pages for %D prompt.
179 * Fix bug in handling tag file error.
181 * Fix obscure bug if input file is deleted while viewing help.
183 * Fix bug handling filenames which include square brackets.
185 * Fix possible buffer overflow in "global" tag search.
187 * Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE.
189 * Fix buffer overflow in reverse search.
191 ======================================================================
193 Major changes between "less" versions 381 and 382
195 * Removed some old copyrighted code.
196 This probably breaks OS/9 support.
198 ======================================================================
200 Major changes between "less" versions 378 and 381
202 * New -L option to disable LESSOPEN processing.
204 * Further support for large (64 bit) file addressing.
205 Large file support is now set up by the configure script.
208 Replace configure.in, acconfig.h, defines.h.top with configure.ac.
210 * Overstriking underscore with underscore is now bold or underlined
211 depending on context.
213 * Use only 7 spaces for line numbers in -N mode, if possible.
215 * Fix some bugs in handling overstriking in UTF-8 files.
217 * Fix some nroff issues in the man page.
219 ======================================================================
221 Major changes between "less" versions 376 and 378
224 Default buffer space is now 64K as documented.
225 Search highlighting works properly when used with -R.
226 Windows version works properly when input file contains carriage returns.
227 Clean up some compiler warnings.
229 ======================================================================
231 Major changes between "less" versions 358 and 376
233 * -x option can now specify multiple variable-width tab stops.
235 * -X option no longer disables keypad initialization.
236 New option --no-keypad disables keypad initialization.
238 * New commands t and T step through multiple tag matches.
239 Added support for "global(1)" tags
240 (see http://www.gnu.org/software/global/global.html).
242 * New prompt style set by option -Pw defines the message printed
243 while waiting for data in the F command.
245 * System-wide lesskey file now defaults to sysless in etc directory
246 instead of .sysless in bin directory.
247 Use "configure --sysconfdir=..." to change it.
248 (For backwards compatibility, .sysless in bin is still recognized.)
250 * Pressing RightArrow or LeftArrow while entering a number now shifts
251 the display N columns rather than editing the number itself.
253 * Status column (enabled with -J) now shows search results.
255 * Windows version sets window title.
257 * Default LESSCHARSET for MS-DOS versions is now "dos".
259 * Searching works better with ANSI (SGR) escape sequences.
260 ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version.
262 * Improved performance in reading very large pipes.
264 * Eliminated some dependencies on file offets being 32 bits.
266 * Fixed problems when viewing files with very long lines.
268 * Fixed overstriking in UTF-8 mode, and overstriking tabs.
270 * Improved horizontal shifting of text using -R option with ANSI color.
272 * Improved handling of filenames containing shell metacharacters.
274 * Some fixes for EBCDIC systems.
276 * Some fixes for OS/2 systems.
278 ======================================================================
280 Major changes between "less" versions 354 and 358
282 * Add -J (--status-column) option to display a status column.
284 * Add -# (--shift) option to set default horizontal shift distance.
285 Default horizontal shift distance is now one-half screen width.
287 * Horizontal shifting does not shift line numbers if -N is in effect.
289 * Horizontal shifting acts as though -S were set, to avoid confusion.
291 ======================================================================
294 Major changes between "less" versions 352 and 354
296 * Allow space after numeric-valued command line options.
298 * Fix problem with configuring terminal libraries on some systems.
300 * Add support for PCRE regular expression library.
302 * Add --with-regex option to configure to allow manually selecting
303 a regular expression library.
305 * Fix bug compiling with SECURE = 1.
307 ======================================================================
310 Major changes between "less" versions 346 and 352
312 * Enable UTF-8 if "UTF-8" appears in locale-related environment variables.
314 * Add --with-editor option to configure script.
316 * The -M prompt and = message now show the top and bottom line number.
318 * Fix bug in running the editor on a file whose name contains quotes, etc.
320 * Fix bug in horizontal scrolling of long lines.
322 * Fix bug in doing :d on a file which contains marks.
324 * Fix bug causing cleared lines to sometimes be filled with standout,
325 bold, underline, etc. on certain terminals.
327 * Fixes for MS-DOS (DJGPP) version.
329 ======================================================================
332 Major changes between "less" versions 340 and 346
334 * The UTF-8 character set is now supported.
336 * The default character set is now latin1 rather than ascii.
338 * New option -R (--RAW-CONTROL-CHARS) is like -r but handles
339 long (wrapped) lines correctly, as long as the input contains only
340 normal text and ANSI color escape sequences.
342 * New option -F (--quit-if-one-screen) quits if the text fits on
345 * The -w option now highlights the target line of a g or p command.
347 * A system-wide lesskey file is supported (LESSKEY_SYSTEM).
349 * New escape for prompt strings: %c is replaced by column number.
351 * New escape for prompt strings: %P is replaced by percentage into
352 file, based on line number rather than byte offset.
354 * HOME and END keys now jump to beginning of file or end of file.
356 ======================================================================
359 Major changes between "less" versions 337 and 340
361 * Command line options for less may now be given in either the old
362 single-letter form, or a new long name form (--option-name).
363 See the less man page or "less --help" for the list of long option names.
365 * Command line options for lesskey may now be given in a new long name
366 form. See the lesskey man page for the list of long option names.
368 * New command -- toggles an option using the long option name.
370 * New command __ queries an option using the long option name.
372 * The old -- command is renamed as -!.
374 * If a ^P is entered between the dash and the option letter of the -
375 command, the message describing the new setting is suppressed.
377 * Lesskey files may now contain \k escape sequences to represent the
378 "special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE).
380 * New command :d removes the current file from the list of files.
382 * New option -~ (like -w before version 335)
383 suppresses tildes after end-of-file.
385 * Less is now released under the GNU General Public License.
387 ======================================================================
390 Major changes between "less" versions 335 and 337
392 * Fixed bugs in "make install".
394 ======================================================================
397 Major changes between "less" versions 332 and 335
399 * The old -w flag (suppress tildes after end-of-file) has been removed.
401 * New -w flag highlights the first new line after a forward-screen.
403 * New -W flag highlights the first new line after any forward movement.
405 * Window resize works even if LINES and/or COLUMNS environment
406 variables are incorrect.
408 * New percent escapes for prompt strings:
409 %d is replaced by the page number, and
410 %D is replaced by the number of pages in the file.
412 * Added charsets "iso8859" and "ebcdic".
414 * In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined.
416 * Fixed some bugs causing incorrect display on DOS/Windows.
418 ======================================================================
421 Major changes between "less" versions 330 and 332
423 * Filenames from the command line are entered into the command history,
424 so UPARROW/DOWNARROW can be used to retrieve them from the :e command.
426 * Now works correctly on Windows when using a scrolling terminal
427 window (buffer larger than display window).
429 * On Windows, now restores the console screen on exit.
430 Use -X to get the old behavior.
432 * Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed.
434 * Fixed bug on Windows when piping output of an interactive program.
436 * Fixed bug in tags file processing when tags file has DOS-style
437 line terminators (CR/LF).
439 * Fixed compilation problem on OS/2.
441 ======================================================================
444 Major changes between "less" versions 321 and 330
446 * Now supports filenames containing spaces (in double quotes).
447 New option -" can be used to change the quoting characters.
449 * In filename completion, a slash is appended to a directory name.
450 If the environment variable LESSSEPARATOR is set, the value of
451 that variable, rather than a slash, is appended.
453 * LeftArrow and RightArrow are same as ESC-[ and ESC-].
455 * Added commands ESC-( and ESC-), same as ESC-[ and ESC-].
457 * A "quit" command defined in a lesskey file may now have an "extra"
458 string, which is used to return an exit code from less when it quits.
460 * New environment variables LESSMETACHARS and LESSMETAESCAPE provide
461 more control over how less interfaces to the shell.
463 * Ported to Microsoft Visual C compiler for Windows.
465 * Ported to DJGPP compiler for MS-DOS.
469 ======================================================================
472 Major changes between "less" versions 291 and 321
474 * Command line at bottom of screen now scrolls, so it can be longer
475 than the screen width.
477 * New commands ESC-] and ESC-[ scroll the display horizontally.
479 * New command ESC-SPACE scrolls forward a full screen, even if it
482 * Alternate modifiers for search commands: ^N is same as !,
483 ^F is same as @, and ^E is same as *.
485 * New modifier for search commands: ^K means highlight the matches
486 currently on-screen, but don't move to the first match.
488 * New modifier for search commands: ^R means don't use regular
489 expressions in the search.
491 * Environment variable LESSKEY gives name of default lesskey file.
493 * Environment variable LESSSECURE will force less to run in
496 * Command line argument "--" signals that the rest of the arguments
497 are files (not option flags).
499 * Help file (less.hlp) is no longer installed. Help text is now
500 embedded in the less executable itself.
502 * Added -Ph to change the prompt for the help text.
503 Added -Ps to change the default short prompt (same as plain -P).
505 * Ported to the Borland C compiler for MS-DOS.
507 * Ported to Windows 95 & Windows NT.
511 * Ported to GNU Hurd.
513 ======================================================================
516 Major changes between "less" versions 290 and 291
518 * Less environment variables can be specified in lesskey files.
520 * Fixed MS-DOS build.
522 ======================================================================
525 Major changes between "less" versions 278 and 290
527 * Accepts GNU-style options "--help" and "--version".
529 * OS/2 version looks for less.ini in $HOME before $INIT and $PATH.
533 ======================================================================
536 Major changes between "less" versions 252 and 278
538 * A LESSOPEN preprocessor may now pipe the converted file data to less,
539 rather than writing it to a temporary file.
541 * Search pattern highlighting has been fixed. It now highlights
542 reliably, even if a string is split across two screen lines,
545 * The -F flag (which suppress search highlighting) has been changed
546 to -G. A new flag, -g, changes search highlighting to highlight
547 only the string found by the last search command, instead of all
548 strings which match the last search command.
550 * New flag -I acts like -i, but ignores case even if the search
551 pattern contains uppercase letters.
553 * Less now checks for the environment variable VISUAL before EDITOR.
557 ======================================================================
560 Major changes between "less" versions 237 and 252
562 * Changes in line-editing keys:
563 The literal key is now ^V or ^A rather than \ (backslash).
564 Filename completion commands (TAB and ^L) are disabled
565 when typing a search pattern.
567 * Line-editing command keys can be redefined using lesskey.
569 * Lesskey with no input file defaults to $HOME/.lesskey
570 rather than standard input.
572 * New option -V displays version number of less.
574 * New option -V displays version number of lesskey.
576 * Help file less.hlp is now installed by default in /usr/local/share
577 rather than /usr/local/lib.
580 ======================================================================
583 Major changes between "less" versions 170 and 237
585 * By popular demand, text which matches the current search pattern
586 is highlighted. New -F flag disables this feature.
588 * Henry Spencer's regexp.c is now included, for systems which do not
589 have a regular expression library.
590 regexp.c is Copyright (c) 1986 by University of Toronto.
592 * New line-editing keys, including command history (arrow keys) and
593 filename completion (TAB).
595 * Input preprocessor allows modification of input files (e.g. uncompress)
596 via LESSOPEN/LESSCLOSE environment variables.
598 * New -X flag disables sending termcap "ti" and "te" (initialize and
599 deinitialize) strings to the terminal.
601 * Changing -i from within less now correctly affects a subsequent
604 * Searching for underlined or overstruck text now works when the -u
605 flag is in effect, rather than the -i flag.
607 * Use setlocale (LANG and LC_CTYPE environment variables) to determine
608 the character set if LESSCHARSET/LESSCHARDEF are not set.
610 * The default format for displaying binary characters is now standout
611 (reverse video) rather than blinking. This can still be changed by
612 setting the LESSBINFMT environment variable.
614 * Use autoconf installation technology.
618 ********************************
619 Things that may surprise you
620 ********************************
622 * When you enter text at the bottom of the screen (search string,
623 filename, etc.), some keys act different than previously.
624 Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L
625 now have line editing functions.
627 * Some previous unofficial versions of less were able to display
628 compressed files. The new LESSOPEN/LESSCLOSE feature now provides
629 this functionality in a different way.
631 * Some previous unofficial versions of less provided a -Z flag to
632 set the number of lines of text to retain between full screen scrolls.
633 The -z-n flag (that is, -z with a negative number) provides this
637 ======================================================================
640 Major changes between "less" versions 123 and 170
642 * New option -j allows target lines to be positioned anywhere on screen.
644 * New option -S truncates displayed line at the screen width,
645 rather than wrapping onto the next line.
647 * New option -y limits amount of forward scroll.
649 * New option -T specifies a "tags" file.
651 * Non-printable, non-control characters are displayed in octal.
652 Such characters, as well as control characters, are displayed
655 * New command -+ sets an option to its default.
656 * New command -- sets an option to the opposite of its default.
658 * Lesskey file may have a string appended to a key's action,
659 which acts as though typed in after the command.
661 * New commands ESC-^F and ESC-^B match arbitrary types of brackets.
663 * New command F monitors a growing file (like "tail -f").
665 * New command | pipes a section of the input file into a shell command.
667 * New command :x directly jumps to a file in the command line list.
669 * Search commands have been enhanced and reorganized:
670 n Repeat search, same direction.
671 N Repeat search, opposite direction.
672 ESC-/ Search forward thru file boundaries
673 ESC-? Search backward thru file boundaries
674 ESC-n Repeat search thru file boundaries, same direction.
675 ESC-N Repeat search thru file boundaries, opposite direction.
676 Special character * causes search to search thru file boundaries.
677 Special character @ causes search to begin at start/end of file list.
679 * Examining a new file adds it to the command line list.
680 A list of files, or an expression which matches more than one file,
681 may be examined; all of them are added to the command line list.
683 * Environment variables LESSCHARSET and LESSCHARDEF can define
684 a non-ASCII character set.
686 * Partial support for MSDOS, including options -R for repainting screen
687 on quit, -v/-V to select video mode, and -W to change window size.
690 ======================================================================
693 Major changes between "less" versions 97 and 123
695 * New option (-N) causes line numbers to be displayed in the
696 text of the file (like vi "set nu").
698 * New option (-?) prints help message immediately.
700 * New option (-r) displays "raw" control characters, without
701 mapping them to ^X notation.
703 * New option (-f) forces less to open non-regular files
706 * New option (-k) can be used to specify lesskey files by name.
708 * New option (-y) can be used to set a forward scroll limit
709 (like -h sets a backward scroll limit).
711 * File marks (set by the m command) are now preserved when a new
712 file is edited. The ' command can thus be used to switch files.
714 * New command ESC-/ searches all files (on the command line)
717 * New command ESC-n repeats previous search, spanning files.
719 * The N command has been changed to repeat the previous search
720 in the reverse direction. The old N command is still available
723 * New command ESC-N repeats previous search in the reverse
724 direction and spanning files.
726 * 8 bit characters are now supported. A new option (-g) can be
727 used to strip off the eighth bit (the previous behavior).
729 * Options which take a following string (like -t) may now
730 optionally have a space between the option letter and the string.
732 * Six new commands { } ( ) [ and ] can be used to match
733 brackets of specific types, similar to vi % command.
735 * New commands z and w move forward/backward one window and
736 simultaneously set the window size.
738 * Prompt string expansion now has %L for line number of the last
739 line in the file, and %E for the name of the editor.
740 Also, % escapes which refer to a line (b=bottom, t=top, etc.)
741 can use j for the jump target line.
743 * New environment variable LESSEDIT can be used to tailor the
744 command string passed to the editor by the v command.
746 * Examining a file which was previously examined will return
747 to the same position in the file.
749 * A "%" is expanded to the current filename and a "#" to the
750 previous filename, in both shell commands and the E command.
751 (Previously % worked only in shell commands and # worked
752 only in the E command.)
754 * New command ":ta" is equivalent to "-t".
756 * New command "s" is equivalent to "-l".
758 * The - command may be followed by "+X" to revert to the default
759 for option X, or "-X" to get the opposite of the default.
761 * Lesskey files may now include characters after the action as
762 extra input to be parsed after the action; for example:
763 "toggle-option X" to toggle a specific option X.