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 416 and 418
18 * Color escape sequences are now supported in WIN32 build.
20 * Makefile now uses EXEEXT feature of autoconf.
22 * Fix search bug when using -R and text contains ANSI color escape sequences.
24 * Fix crash when using -r with UTF-8 text containing 0x9B bytes.
26 * Fix display bug when using ' command to move less than one page forward.
28 * Update GPL to version 3.
30 ======================================================================
32 Major changes between "less" versions 409 and 416
34 * New --follow-name option makes F command follow the name of a file
35 rather than the file descriptor if an open file is renamed.
37 * Make searching with -i/-I work correctly with non-ASCII text.
41 ======================================================================
43 Major changes between "less" versions 406 and 409
45 * Support CSI escape sequences, like SGR escape sequences.
47 * Fix bug which caused screen to fail to repaint when window is resized.
49 * Fix bug in using -i and -I flags with non-ASCII text.
51 * Fix configure bug on systems which don't support langinfo.h.
53 * Fix crash when searching text containing certain invalid UTF-8 sequences.
55 ======================================================================
57 Major changes between "less" versions 394 and 406
59 * Allow decimal point in number for % (percent) command.
61 * Allow decimal point in number for -j option (fraction of screen height).
63 * Make n command fetch previous pattern from history file on first search.
65 * Don't rewrite history file if it has not changed.
67 * Don't move to bottom of screen on first page.
69 * Don't output extraneous newlines, so copy & pasting lines from the
72 * The -c option has been made identical with the -C option.
74 * Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate
75 that no history file should be used.
77 * Search can now find text which follows a null byte, if the PCRE
78 library is used, or if no-regex searching (ctrl-R) is used.
80 * Better compatibility with POSIX more specification.
82 * Make -f work for directories.
84 * Make "t" cmd traverse tags in the correct order.
86 * Allow a few binary characters in the input file before warning
87 that the file is binary.
89 * Don't warn that file is binary if it merely contains ANSI color sequences
92 * Update Unicode character tables.
94 * Support DESTDIR in Makefile.
96 * Fix bug when filename contains certain shell metacharacters such as "$".
98 * Fix bug when resizing the window while waiting for input from a pipe.
100 * Fix configure bugs.
102 ======================================================================
104 Major changes between "less" versions 382 and 394
106 * Add history file to save search and shell command history between
109 * Improve behavior of history list for search and shell commands.
111 * Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C.
113 * Improve handling of UTF-8 files and commands, including better
114 line wrapping and handling double-width chars.
116 * Added LESSUTFBINFMT environment variable to control display of
117 non-printable characters in a UTF-8 file.
119 * Add --with-secure option to configure, to make it easier to
120 build a secure version of less.
122 * Show search matches in the status column even if search highlights
123 are disabled via the -G option or the ESC-u command.
125 * Improve performance when the file contains very long lines.
127 * Add "windows" charset.
129 * Add man page for lessecho.
131 * Add support for erase2 character, treated same as erase.
133 * Use ASCII lowercase/uppercase logic when operating on the command line.
135 * Update makefile for Borland C++ 5.5.1.
137 * Fix bug in calculating number of pages for %D prompt.
139 * Fix bug in handling tag file error.
141 * Fix obscure bug if input file is deleted while viewing help.
143 * Fix bug handling filenames which include square brackets.
145 * Fix possible buffer overflow in "global" tag search.
147 * Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE.
149 * Fix buffer overflow in reverse search.
151 ======================================================================
153 Major changes between "less" versions 381 and 382
155 * Removed some old copyrighted code.
156 This probably breaks OS/9 support.
158 ======================================================================
160 Major changes between "less" versions 378 and 381
162 * New -L option to disable LESSOPEN processing.
164 * Further support for large (64 bit) file addressing.
165 Large file support is now set up by the configure script.
168 Replace configure.in, acconfig.h, defines.h.top with configure.ac.
170 * Overstriking underscore with underscore is now bold or underlined
171 depending on context.
173 * Use only 7 spaces for line numbers in -N mode, if possible.
175 * Fix some bugs in handling overstriking in UTF-8 files.
177 * Fix some nroff issues in the man page.
179 ======================================================================
181 Major changes between "less" versions 376 and 378
184 Default buffer space is now 64K as documented.
185 Search highlighting works properly when used with -R.
186 Windows version works properly when input file contains carriage returns.
187 Clean up some compiler warnings.
189 ======================================================================
191 Major changes between "less" versions 358 and 376
193 * -x option can now specify multiple variable-width tab stops.
195 * -X option no longer disables keypad initialization.
196 New option --no-keypad disables keypad initialization.
198 * New commands t and T step through multiple tag matches.
199 Added support for "global(1)" tags
200 (see http://www.gnu.org/software/global/global.html).
202 * New prompt style set by option -Pw defines the message printed
203 while waiting for data in the F command.
205 * System-wide lesskey file now defaults to sysless in etc directory
206 instead of .sysless in bin directory.
207 Use "configure --sysconfdir=..." to change it.
208 (For backwards compatibility, .sysless in bin is still recognized.)
210 * Pressing RightArrow or LeftArrow while entering a number now shifts
211 the display N columns rather than editing the number itself.
213 * Status column (enabled with -J) now shows search results.
215 * Windows version sets window title.
217 * Default LESSCHARSET for MS-DOS versions is now "dos".
219 * Searching works better with ANSI (SGR) escape sequences.
220 ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version.
222 * Improved performance in reading very large pipes.
224 * Eliminated some dependencies on file offets being 32 bits.
226 * Fixed problems when viewing files with very long lines.
228 * Fixed overstriking in UTF-8 mode, and overstriking tabs.
230 * Improved horizontal shifting of text using -R option with ANSI color.
232 * Improved handling of filenames containing shell metacharacters.
234 * Some fixes for EBCDIC systems.
236 * Some fixes for OS/2 systems.
238 ======================================================================
240 Major changes between "less" versions 354 and 358
242 * Add -J (--status-column) option to display a status column.
244 * Add -# (--shift) option to set default horizontal shift distance.
245 Default horizontal shift distance is now one-half screen width.
247 * Horizontal shifting does not shift line numbers if -N is in effect.
249 * Horizontal shifting acts as though -S were set, to avoid confusion.
251 ======================================================================
254 Major changes between "less" versions 352 and 354
256 * Allow space after numeric-valued command line options.
258 * Fix problem with configuring terminal libraries on some systems.
260 * Add support for PCRE regular expression library.
262 * Add --with-regex option to configure to allow manually selecting
263 a regular expression library.
265 * Fix bug compiling with SECURE = 1.
267 ======================================================================
270 Major changes between "less" versions 346 and 352
272 * Enable UTF-8 if "UTF-8" appears in locale-related environment variables.
274 * Add --with-editor option to configure script.
276 * The -M prompt and = message now show the top and bottom line number.
278 * Fix bug in running the editor on a file whose name contains quotes, etc.
280 * Fix bug in horizontal scrolling of long lines.
282 * Fix bug in doing :d on a file which contains marks.
284 * Fix bug causing cleared lines to sometimes be filled with standout,
285 bold, underline, etc. on certain terminals.
287 * Fixes for MS-DOS (DJGPP) version.
289 ======================================================================
292 Major changes between "less" versions 340 and 346
294 * The UTF-8 character set is now supported.
296 * The default character set is now latin1 rather than ascii.
298 * New option -R (--RAW-CONTROL-CHARS) is like -r but handles
299 long (wrapped) lines correctly, as long as the input contains only
300 normal text and ANSI color escape sequences.
302 * New option -F (--quit-if-one-screen) quits if the text fits on
305 * The -w option now highlights the target line of a g or p command.
307 * A system-wide lesskey file is supported (LESSKEY_SYSTEM).
309 * New escape for prompt strings: %c is replaced by column number.
311 * New escape for prompt strings: %P is replaced by percentage into
312 file, based on line number rather than byte offset.
314 * HOME and END keys now jump to beginning of file or end of file.
316 ======================================================================
319 Major changes between "less" versions 337 and 340
321 * Command line options for less may now be given in either the old
322 single-letter form, or a new long name form (--option-name).
323 See the less man page or "less --help" for the list of long option names.
325 * Command line options for lesskey may now be given in a new long name
326 form. See the lesskey man page for the list of long option names.
328 * New command -- toggles an option using the long option name.
330 * New command __ queries an option using the long option name.
332 * The old -- command is renamed as -!.
334 * If a ^P is entered between the dash and the option letter of the -
335 command, the message describing the new setting is suppressed.
337 * Lesskey files may now contain \k escape sequences to represent the
338 "special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE).
340 * New command :d removes the current file from the list of files.
342 * New option -~ (like -w before version 335)
343 suppresses tildes after end-of-file.
345 * Less is now released under the GNU General Public License.
347 ======================================================================
350 Major changes between "less" versions 335 and 337
352 * Fixed bugs in "make install".
354 ======================================================================
357 Major changes between "less" versions 332 and 335
359 * The old -w flag (suppress tildes after end-of-file) has been removed.
361 * New -w flag highlights the first new line after a forward-screen.
363 * New -W flag highlights the first new line after any forward movement.
365 * Window resize works even if LINES and/or COLUMNS environment
366 variables are incorrect.
368 * New percent escapes for prompt strings:
369 %d is replaced by the page number, and
370 %D is replaced by the number of pages in the file.
372 * Added charsets "iso8859" and "ebcdic".
374 * In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined.
376 * Fixed some bugs causing incorrect display on DOS/Windows.
378 ======================================================================
381 Major changes between "less" versions 330 and 332
383 * Filenames from the command line are entered into the command history,
384 so UPARROW/DOWNARROW can be used to retrieve them from the :e command.
386 * Now works correctly on Windows when using a scrolling terminal
387 window (buffer larger than display window).
389 * On Windows, now restores the console screen on exit.
390 Use -X to get the old behavior.
392 * Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed.
394 * Fixed bug on Windows when piping output of an interactive program.
396 * Fixed bug in tags file processing when tags file has DOS-style
397 line terminators (CR/LF).
399 * Fixed compilation problem on OS/2.
401 ======================================================================
404 Major changes between "less" versions 321 and 330
406 * Now supports filenames containing spaces (in double quotes).
407 New option -" can be used to change the quoting characters.
409 * In filename completion, a slash is appended to a directory name.
410 If the environment variable LESSSEPARATOR is set, the value of
411 that variable, rather than a slash, is appended.
413 * LeftArrow and RightArrow are same as ESC-[ and ESC-].
415 * Added commands ESC-( and ESC-), same as ESC-[ and ESC-].
417 * A "quit" command defined in a lesskey file may now have an "extra"
418 string, which is used to return an exit code from less when it quits.
420 * New environment variables LESSMETACHARS and LESSMETAESCAPE provide
421 more control over how less interfaces to the shell.
423 * Ported to Microsoft Visual C compiler for Windows.
425 * Ported to DJGPP compiler for MS-DOS.
429 ======================================================================
432 Major changes between "less" versions 291 and 321
434 * Command line at bottom of screen now scrolls, so it can be longer
435 than the screen width.
437 * New commands ESC-] and ESC-[ scroll the display horizontally.
439 * New command ESC-SPACE scrolls forward a full screen, even if it
442 * Alternate modifiers for search commands: ^N is same as !,
443 ^F is same as @, and ^E is same as *.
445 * New modifier for search commands: ^K means highlight the matches
446 currently on-screen, but don't move to the first match.
448 * New modifier for search commands: ^R means don't use regular
449 expressions in the search.
451 * Environment variable LESSKEY gives name of default lesskey file.
453 * Environment variable LESSSECURE will force less to run in
456 * Command line argument "--" signals that the rest of the arguments
457 are files (not option flags).
459 * Help file (less.hlp) is no longer installed. Help text is now
460 embedded in the less executable itself.
462 * Added -Ph to change the prompt for the help text.
463 Added -Ps to change the default short prompt (same as plain -P).
465 * Ported to the Borland C compiler for MS-DOS.
467 * Ported to Windows 95 & Windows NT.
471 * Ported to GNU Hurd.
473 ======================================================================
476 Major changes between "less" versions 290 and 291
478 * Less environment variables can be specified in lesskey files.
480 * Fixed MS-DOS build.
482 ======================================================================
485 Major changes between "less" versions 278 and 290
487 * Accepts GNU-style options "--help" and "--version".
489 * OS/2 version looks for less.ini in $HOME before $INIT and $PATH.
493 ======================================================================
496 Major changes between "less" versions 252 and 278
498 * A LESSOPEN preprocessor may now pipe the converted file data to less,
499 rather than writing it to a temporary file.
501 * Search pattern highlighting has been fixed. It now highlights
502 reliably, even if a string is split across two screen lines,
505 * The -F flag (which suppress search highlighting) has been changed
506 to -G. A new flag, -g, changes search highlighting to highlight
507 only the string found by the last search command, instead of all
508 strings which match the last search command.
510 * New flag -I acts like -i, but ignores case even if the search
511 pattern contains uppercase letters.
513 * Less now checks for the environment variable VISUAL before EDITOR.
517 ======================================================================
520 Major changes between "less" versions 237 and 252
522 * Changes in line-editing keys:
523 The literal key is now ^V or ^A rather than \ (backslash).
524 Filename completion commands (TAB and ^L) are disabled
525 when typing a search pattern.
527 * Line-editing command keys can be redefined using lesskey.
529 * Lesskey with no input file defaults to $HOME/.lesskey
530 rather than standard input.
532 * New option -V displays version number of less.
534 * New option -V displays version number of lesskey.
536 * Help file less.hlp is now installed by default in /usr/local/share
537 rather than /usr/local/lib.
540 ======================================================================
543 Major changes between "less" versions 170 and 237
545 * By popular demand, text which matches the current search pattern
546 is highlighted. New -F flag disables this feature.
548 * Henry Spencer's regexp.c is now included, for systems which do not
549 have a regular expression library.
550 regexp.c is Copyright (c) 1986 by University of Toronto.
552 * New line-editing keys, including command history (arrow keys) and
553 filename completion (TAB).
555 * Input preprocessor allows modification of input files (e.g. uncompress)
556 via LESSOPEN/LESSCLOSE environment variables.
558 * New -X flag disables sending termcap "ti" and "te" (initialize and
559 deinitialize) strings to the terminal.
561 * Changing -i from within less now correctly affects a subsequent
564 * Searching for underlined or overstruck text now works when the -u
565 flag is in effect, rather than the -i flag.
567 * Use setlocale (LANG and LC_CTYPE environment variables) to determine
568 the character set if LESSCHARSET/LESSCHARDEF are not set.
570 * The default format for displaying binary characters is now standout
571 (reverse video) rather than blinking. This can still be changed by
572 setting the LESSBINFMT environment variable.
574 * Use autoconf installation technology.
578 ********************************
579 Things that may surprise you
580 ********************************
582 * When you enter text at the bottom of the screen (search string,
583 filename, etc.), some keys act different than previously.
584 Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L
585 now have line editing functions.
587 * Some previous unofficial versions of less were able to display
588 compressed files. The new LESSOPEN/LESSCLOSE feature now provides
589 this functionality in a different way.
591 * Some previous unofficial versions of less provided a -Z flag to
592 set the number of lines of text to retain between full screen scrolls.
593 The -z-n flag (that is, -z with a negative number) provides this
597 ======================================================================
600 Major changes between "less" versions 123 and 170
602 * New option -j allows target lines to be positioned anywhere on screen.
604 * New option -S truncates displayed line at the screen width,
605 rather than wrapping onto the next line.
607 * New option -y limits amount of forward scroll.
609 * New option -T specifies a "tags" file.
611 * Non-printable, non-control characters are displayed in octal.
612 Such characters, as well as control characters, are displayed
615 * New command -+ sets an option to its default.
616 * New command -- sets an option to the opposite of its default.
618 * Lesskey file may have a string appended to a key's action,
619 which acts as though typed in after the command.
621 * New commands ESC-^F and ESC-^B match arbitrary types of brackets.
623 * New command F monitors a growing file (like "tail -f").
625 * New command | pipes a section of the input file into a shell command.
627 * New command :x directly jumps to a file in the command line list.
629 * Search commands have been enhanced and reorganized:
630 n Repeat search, same direction.
631 N Repeat search, opposite direction.
632 ESC-/ Search forward thru file boundaries
633 ESC-? Search backward thru file boundaries
634 ESC-n Repeat search thru file boundaries, same direction.
635 ESC-N Repeat search thru file boundaries, opposite direction.
636 Special character * causes search to search thru file boundaries.
637 Special character @ causes search to begin at start/end of file list.
639 * Examining a new file adds it to the command line list.
640 A list of files, or an expression which matches more than one file,
641 may be examined; all of them are added to the command line list.
643 * Environment variables LESSCHARSET and LESSCHARDEF can define
644 a non-ASCII character set.
646 * Partial support for MSDOS, including options -R for repainting screen
647 on quit, -v/-V to select video mode, and -W to change window size.
650 ======================================================================
653 Major changes between "less" versions 97 and 123
655 * New option (-N) causes line numbers to be displayed in the
656 text of the file (like vi "set nu").
658 * New option (-?) prints help message immediately.
660 * New option (-r) displays "raw" control characters, without
661 mapping them to ^X notation.
663 * New option (-f) forces less to open non-regular files
666 * New option (-k) can be used to specify lesskey files by name.
668 * New option (-y) can be used to set a forward scroll limit
669 (like -h sets a backward scroll limit).
671 * File marks (set by the m command) are now preserved when a new
672 file is edited. The ' command can thus be used to switch files.
674 * New command ESC-/ searches all files (on the command line)
677 * New command ESC-n repeats previous search, spanning files.
679 * The N command has been changed to repeat the previous search
680 in the reverse direction. The old N command is still available
683 * New command ESC-N repeats previous search in the reverse
684 direction and spanning files.
686 * 8 bit characters are now supported. A new option (-g) can be
687 used to strip off the eighth bit (the previous behavior).
689 * Options which take a following string (like -t) may now
690 optionally have a space between the option letter and the string.
692 * Six new commands { } ( ) [ and ] can be used to match
693 brackets of specific types, similar to vi % command.
695 * New commands z and w move forward/backward one window and
696 simultaneously set the window size.
698 * Prompt string expansion now has %L for line number of the last
699 line in the file, and %E for the name of the editor.
700 Also, % escapes which refer to a line (b=bottom, t=top, etc.)
701 can use j for the jump target line.
703 * New environment variable LESSEDIT can be used to tailor the
704 command string passed to the editor by the v command.
706 * Examining a file which was previously examined will return
707 to the same position in the file.
709 * A "%" is expanded to the current filename and a "#" to the
710 previous filename, in both shell commands and the E command.
711 (Previously % worked only in shell commands and # worked
712 only in the E command.)
714 * New command ":ta" is equivalent to "-t".
716 * New command "s" is equivalent to "-l".
718 * The - command may be followed by "+X" to revert to the default
719 for option X, or "-X" to get the opposite of the default.
721 * Lesskey files may now include characters after the action as
722 extra input to be parsed after the action; for example:
723 "toggle-option X" to toggle a specific option X.