NEWS about less
======================================================================
For the latest news about less, see the "less" Web page:
http://www.greenwoodsoftware.com/less
You can also download the latest version of less from there.
To report bugs, suggestions or comments, send email to bug-less@gnu.org
======================================================================
Major changes between "less" versions 487 and 530
* Don't output terminal init sequence if using -F and file fits on one screen.
* When using -S, mark truncated lines with a special character.
The character can be changed or disabled via the new --rscroll option.
* New command M marks the last line displayed on the screen.
* New command ESC-m removes a line mark.
* Status column (enabled via -J) now shows mark letters.
* Status column shows search matches even if highlighting is disabled via -G.
* A second ESC-u command will clear search match markers in the status column.
* Do same ANSI escape code filtering for tag matching that we do for
searching, to help when viewing syntax-highlighted code.
* Catch SIGTERM and clean up before exiting.
* Fix bug initializing default charset on Windows.
* Handle keypad ENTER key correctly if it sends something other than newline.
* Fix buffering bug when using stdin with a LESSOPEN pipe.
* On Windows, allow 'u' in -D option to enable underlining.
* On Windows, use underline in sgr mode.
* On Windows, convert UTF-8 to multibyte if console is not UTF-8.
* Update Unicode tables to 2017-03-08.
* Pass-thru Unicode formating chars (Cf type) instead of treating them
as binary chars. But treat them as binary if -U is set.
* Fix erroneous binary file warning when UTF-8 file contains ANSI SGR sequences.
* Fix bugs when using LESSOPEN and switching between stdin and other files.
* Fix some bugs handling filenames containing shell metacharacters.
* Fix some memory leaks.
* Allow some debugging environment variables to be set in lesskey file.
* Code improvements:
. Use ANSI prototypes in funcs.h declarations.
. Fix some const mismatches.
. Remove archaic "register" in variable declarations.
======================================================================
Major changes between "less" versions 481 and 487
* New commands ESC-{ and ESC-} to shift to start/end of displayed lines.
* Make search highlights work correctly when changing caselessness with -i.
* New option -Da in Windows version to enable SGR mode.
* Fix "nothing to search" error when top or bottom line on screen is empty.
* Fix bug when terminal has no "cm" termcap entry.
* Fix incorrect display when entering double-width chars in search string.
* Fix bug in Unicode handling that missed some double width characters.
* Update Unicode database to 9.0.0.
======================================================================
Major changes between "less" versions 458 and 481
* Don't overwrite history file; just append to it.
* New command ESC-G goes to end of currently buffered data in a pipe.
* Disable history feature when compiled with LESSHISTFILE set to "-".
* In more-compatible mode, make the -p option apply to every file opened,
not just the first one.
* In more-compatible mode, change the -e option to work like -E, not -EF.
* Treat multiple CRs before LF are like one CR (all the CRs are hidden).
* Allow "extra" string in lesskey file to append to a multi-char command
(like a search pattern), without executing the command.
* Ignore -u/-U setting while viewing help file, so that
underline and bold chars are displayed correctly.
* Improve detection of "binary" files in UTF-8 mode.
* Fix bug with ++ commands.
* Fix bug where prompt was sometimes not displayed with +G.
* Fix possible memory corruption
* Fix bugs and improve performance in ampersand filtering.
* Automate construction of Unicode tables from Unicode database.
* Allow %% escape sequence in LESSOPEN variable.
======================================================================
Major changes between "less" versions 451 and 458
* Allow backslash escaping of metacharacters in LESS environment variable
after the --use-backslash option.
* Don't quit if syntax errors are found in command line options.
* Increase sizes of some internal buffers.
* Fix configure bug with --with-regex=none.
* Fix crash with "stty rows 0".
* Fix Win32 attribute display bug.
* Fix display bug when using up/down arrow on the command line.
======================================================================
Major changes between "less" versions 444 and 451
* Add ESC-F command to keep reading data until a pattern is found.
* Use exit code of LESSOPEN script if LESSOPEN starts with "||".
* When up/down arrow is used on the command line immediately after
typing text, the next command starting with that text is found.
* Add support for GNU regex.
* Add configure option --with-regex=none and fix compile errors
when compiling with no regex library.
* Fix bugs handling SGR sequences in Win32.
* Fix possible crashes caused by malformed LESSOPEN or
LESSCLOSE variables.
* Fix bug highlighting text which is discontiguous in the file
due to backspace processing.
* Fix bug in displaying status column when scrolling backwards
with -J and -S in effect.
======================================================================
Major changes between "less" versions 443 and 444
* Fix bug in unget handling that can cause strange effects on the
command line.
* Remove vestiges of obsolete -l option that can cause a crash.
======================================================================
Major changes between "less" versions 436 and 443
* Change search behavior such that when a search is given an explicit
pattern, the entire displayed screen is included in the search and
not just the portion after the target line.
* Add -A option to change search behavior to the old way: only
the portion of the screen after the target line is searched.
* Add %F formatting to prompt strings, replaced by the last component
of the input file.
* Control-G while editing a command exits the command.
* Less now exits with status 2 if control-C is pressed and -K is in effect.
* Fix "ungetc overflow" when passing long commands via the -p option.
* Fix bug in using line filtering via the & command
in combination with -i and -I.
* Fix bug in handling negative arguments to the -j option.
* Fix bug in handling %t in prompt strings.
* Improve handling of long option names.
* Improve percentage calculation for very large files.
======================================================================
Major changes between "less" versions 429 and 436
* Don't pass "-" to non-pipe LESSOPEN unless it starts with "-".
* Allow a fraction as the argument to the -# (--shift) option.
* Fix highlight bug when underlined/overstruck text matches at end of line.
* Fix non-regex searches with ctrl-R.
======================================================================
Major changes between "less" versions 424 and 429
* LESSOPEN pipe will now be used on standard input, if the LESSOPEN
environment variable begins with "|-".
* The -D option with one number now means use the normal background color.
* Don't change permissions on history file if it is not a regular file.
* Fix non-ANSI-compliant code that caused problems with some compilers.
* Fix binary file detection in UTF-8 mode.
* Fix display problems with long lines on "ignaw" terminals.
* Fix problem interrupting the line number calculation for initial prompt.
* Fix SGR emulation when dealing with multiple attributes (eg. bold+underline).
* Fix highlight bug when searching for underlined/overstruck text.
======================================================================
Major changes between "less" versions 418 and 424
* New "&" command allows filtering of lines based on a pattern.
* Status column now displays a search match, even if the matched
string is scrolled off screen because -S is in effect.
* Improve behavior of -F option.
* Allow CSI character (0x9B) to work in UTF-8 mode.
* Output carriage return at startup in case terminal doesn't default
to column 1.
* Fix bug in '' (quote, quote) command after G command.
======================================================================
Major changes between "less" versions 416 and 418
* Color escape sequences are now supported in WIN32 build.
* Makefile now uses EXEEXT feature of autoconf.
* Fix search bug when using -R and text contains ANSI color escape sequences.
* Fix crash when using -r with UTF-8 text containing 0x9B bytes.
* Fix display bug when using ' command to move less than one page forward.
* Update GPL to version 3.
======================================================================
Major changes between "less" versions 409 and 416
* New --follow-name option makes F command follow the name of a file
rather than the file descriptor if an open file is renamed.
* Make searching with -i/-I work correctly with non-ASCII text.
* Fix DJGPP build.
======================================================================
Major changes between "less" versions 406 and 409
* Support CSI escape sequences, like SGR escape sequences.
* Fix bug which caused screen to fail to repaint when window is resized.
* Fix bug in using -i and -I flags with non-ASCII text.
* Fix configure bug on systems which don't support langinfo.h.
* Fix crash when searching text containing certain invalid UTF-8 sequences.
======================================================================
Major changes between "less" versions 394 and 406
* Allow decimal point in number for % (percent) command.
* Allow decimal point in number for -j option (fraction of screen height).
* Make n command fetch previous pattern from history file on first search.
* Don't rewrite history file if it has not changed.
* Don't move to bottom of screen on first page.
* Don't output extraneous newlines, so copy & pasting lines from the
output works better.
* The -c option has been made identical with the -C option.
* Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate
that no history file should be used.
* Search can now find text which follows a null byte, if the PCRE
library is used, or if no-regex searching (ctrl-R) is used.
* Better compatibility with POSIX more specification.
* Make -f work for directories.
* Make "t" cmd traverse tags in the correct order.
* Allow a few binary characters in the input file before warning
that the file is binary.
* Don't warn that file is binary if it merely contains ANSI color sequences
and -R is in effect.
* Update Unicode character tables.
* Support DESTDIR in Makefile.
* Fix bug when filename contains certain shell metacharacters such as "$".
* Fix bug when resizing the window while waiting for input from a pipe.
* Fix configure bugs.
======================================================================
Major changes between "less" versions 382 and 394
* Add history file to save search and shell command history between
invocations of less.
* Improve behavior of history list for search and shell commands.
* Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C.
* Improve handling of UTF-8 files and commands, including better
line wrapping and handling double-width chars.
* Added LESSUTFBINFMT environment variable to control display of
non-printable characters in a UTF-8 file.
* Add --with-secure option to configure, to make it easier to
build a secure version of less.
* Show search matches in the status column even if search highlights
are disabled via the -G option or the ESC-u command.
* Improve performance when the file contains very long lines.
* Add "windows" charset.
* Add man page for lessecho.
* Add support for erase2 character, treated same as erase.
* Use ASCII lowercase/uppercase logic when operating on the command line.
* Update makefile for Borland C++ 5.5.1.
* Fix bug in calculating number of pages for %D prompt.
* Fix bug in handling tag file error.
* Fix obscure bug if input file is deleted while viewing help.
* Fix bug handling filenames which include square brackets.
* Fix possible buffer overflow in "global" tag search.
* Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE.
* Fix buffer overflow in reverse search.
======================================================================
Major changes between "less" versions 381 and 382
* Removed some old copyrighted code.
This probably breaks OS/9 support.
======================================================================
Major changes between "less" versions 378 and 381
* New -L option to disable LESSOPEN processing.
* Further support for large (64 bit) file addressing.
Large file support is now set up by the configure script.
* Use autoconf 2.54.
Replace configure.in, acconfig.h, defines.h.top with configure.ac.
* Overstriking underscore with underscore is now bold or underlined
depending on context.
* Use only 7 spaces for line numbers in -N mode, if possible.
* Fix some bugs in handling overstriking in UTF-8 files.
* Fix some nroff issues in the man page.
======================================================================
Major changes between "less" versions 376 and 378
* Bug fixes:
Default buffer space is now 64K as documented.
Search highlighting works properly when used with -R.
Windows version works properly when input file contains carriage returns.
Clean up some compiler warnings.
======================================================================
Major changes between "less" versions 358 and 376
* -x option can now specify multiple variable-width tab stops.
* -X option no longer disables keypad initialization.
New option --no-keypad disables keypad initialization.
* New commands t and T step through multiple tag matches.
Added support for "global(1)" tags
(see http://www.gnu.org/software/global/global.html).
* New prompt style set by option -Pw defines the message printed
while waiting for data in the F command.
* System-wide lesskey file now defaults to sysless in etc directory
instead of .sysless in bin directory.
Use "configure --sysconfdir=..." to change it.
(For backwards compatibility, .sysless in bin is still recognized.)
* Pressing RightArrow or LeftArrow while entering a number now shifts
the display N columns rather than editing the number itself.
* Status column (enabled with -J) now shows search results.
* Windows version sets window title.
* Default LESSCHARSET for MS-DOS versions is now "dos".
* Searching works better with ANSI (SGR) escape sequences.
ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version.
* Improved performance in reading very large pipes.
* Eliminated some dependencies on file offets being 32 bits.
* Fixed problems when viewing files with very long lines.
* Fixed overstriking in UTF-8 mode, and overstriking tabs.
* Improved horizontal shifting of text using -R option with ANSI color.
* Improved handling of filenames containing shell metacharacters.
* Some fixes for EBCDIC systems.
* Some fixes for OS/2 systems.
======================================================================
Major changes between "less" versions 354 and 358
* Add -J (--status-column) option to display a status column.
* Add -# (--shift) option to set default horizontal shift distance.
Default horizontal shift distance is now one-half screen width.
* Horizontal shifting does not shift line numbers if -N is in effect.
* Horizontal shifting acts as though -S were set, to avoid confusion.
======================================================================
Major changes between "less" versions 352 and 354
* Allow space after numeric-valued command line options.
* Fix problem with configuring terminal libraries on some systems.
* Add support for PCRE regular expression library.
* Add --with-regex option to configure to allow manually selecting
a regular expression library.
* Fix bug compiling with SECURE = 1.
======================================================================
Major changes between "less" versions 346 and 352
* Enable UTF-8 if "UTF-8" appears in locale-related environment variables.
* Add --with-editor option to configure script.
* The -M prompt and = message now show the top and bottom line number.
* Fix bug in running the editor on a file whose name contains quotes, etc.
* Fix bug in horizontal scrolling of long lines.
* Fix bug in doing :d on a file which contains marks.
* Fix bug causing cleared lines to sometimes be filled with standout,
bold, underline, etc. on certain terminals.
* Fixes for MS-DOS (DJGPP) version.
======================================================================
Major changes between "less" versions 340 and 346
* The UTF-8 character set is now supported.
* The default character set is now latin1 rather than ascii.
* New option -R (--RAW-CONTROL-CHARS) is like -r but handles
long (wrapped) lines correctly, as long as the input contains only
normal text and ANSI color escape sequences.
* New option -F (--quit-if-one-screen) quits if the text fits on
the first screen.
* The -w option now highlights the target line of a g or p command.
* A system-wide lesskey file is supported (LESSKEY_SYSTEM).
* New escape for prompt strings: %c is replaced by column number.
* New escape for prompt strings: %P is replaced by percentage into
file, based on line number rather than byte offset.
* HOME and END keys now jump to beginning of file or end of file.
======================================================================
Major changes between "less" versions 337 and 340
* Command line options for less may now be given in either the old
single-letter form, or a new long name form (--option-name).
See the less man page or "less --help" for the list of long option names.
* Command line options for lesskey may now be given in a new long name
form. See the lesskey man page for the list of long option names.
* New command -- toggles an option using the long option name.
* New command __ queries an option using the long option name.
* The old -- command is renamed as -!.
* If a ^P is entered between the dash and the option letter of the -
command, the message describing the new setting is suppressed.
* Lesskey files may now contain \k escape sequences to represent the
"special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE).
* New command :d removes the current file from the list of files.
* New option -~ (like -w before version 335)
suppresses tildes after end-of-file.
* Less is now released under the GNU General Public License.
======================================================================
Major changes between "less" versions 335 and 337
* Fixed bugs in "make install".
======================================================================
Major changes between "less" versions 332 and 335
* The old -w flag (suppress tildes after end-of-file) has been removed.
* New -w flag highlights the first new line after a forward-screen.
* New -W flag highlights the first new line after any forward movement.
* Window resize works even if LINES and/or COLUMNS environment
variables are incorrect.
* New percent escapes for prompt strings:
%d is replaced by the page number, and
%D is replaced by the number of pages in the file.
* Added charsets "iso8859" and "ebcdic".
* In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined.
* Fixed some bugs causing incorrect display on DOS/Windows.
======================================================================
Major changes between "less" versions 330 and 332
* Filenames from the command line are entered into the command history,
so UPARROW/DOWNARROW can be used to retrieve them from the :e command.
* Now works correctly on Windows when using a scrolling terminal
window (buffer larger than display window).
* On Windows, now restores the console screen on exit.
Use -X to get the old behavior.
* Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed.
* Fixed bug on Windows when piping output of an interactive program.
* Fixed bug in tags file processing when tags file has DOS-style
line terminators (CR/LF).
* Fixed compilation problem on OS/2.
======================================================================
Major changes between "less" versions 321 and 330
* Now supports filenames containing spaces (in double quotes).
New option -" can be used to change the quoting characters.
* In filename completion, a slash is appended to a directory name.
If the environment variable LESSSEPARATOR is set, the value of
that variable, rather than a slash, is appended.
* LeftArrow and RightArrow are same as ESC-[ and ESC-].
* Added commands ESC-( and ESC-), same as ESC-[ and ESC-].
* A "quit" command defined in a lesskey file may now have an "extra"
string, which is used to return an exit code from less when it quits.
* New environment variables LESSMETACHARS and LESSMETAESCAPE provide
more control over how less interfaces to the shell.
* Ported to Microsoft Visual C compiler for Windows.
* Ported to DJGPP compiler for MS-DOS.
* Bug fixes.
======================================================================
Major changes between "less" versions 291 and 321
* Command line at bottom of screen now scrolls, so it can be longer
than the screen width.
* New commands ESC-] and ESC-[ scroll the display horizontally.
* New command ESC-SPACE scrolls forward a full screen, even if it
hits end-of-file.
* Alternate modifiers for search commands: ^N is same as !,
^F is same as @, and ^E is same as *.
* New modifier for search commands: ^K means highlight the matches
currently on-screen, but don't move to the first match.
* New modifier for search commands: ^R means don't use regular
expressions in the search.
* Environment variable LESSKEY gives name of default lesskey file.
* Environment variable LESSSECURE will force less to run in
"secure" mode.
* Command line argument "--" signals that the rest of the arguments
are files (not option flags).
* Help file (less.hlp) is no longer installed. Help text is now
embedded in the less executable itself.
* Added -Ph to change the prompt for the help text.
Added -Ps to change the default short prompt (same as plain -P).
* Ported to the Borland C compiler for MS-DOS.
* Ported to Windows 95 & Windows NT.
* Ported to OS-9.
* Ported to GNU Hurd.
======================================================================
Major changes between "less" versions 290 and 291
* Less environment variables can be specified in lesskey files.
* Fixed MS-DOS build.
======================================================================
Major changes between "less" versions 278 and 290
* Accepts GNU-style options "--help" and "--version".
* OS/2 version looks for less.ini in $HOME before $INIT and $PATH.
* Bug fixes
======================================================================
Major changes between "less" versions 252 and 278
* A LESSOPEN preprocessor may now pipe the converted file data to less,
rather than writing it to a temporary file.
* Search pattern highlighting has been fixed. It now highlights
reliably, even if a string is split across two screen lines,
contains TABs, etc.
* The -F flag (which suppress search highlighting) has been changed
to -G. A new flag, -g, changes search highlighting to highlight
only the string found by the last search command, instead of all
strings which match the last search command.
* New flag -I acts like -i, but ignores case even if the search
pattern contains uppercase letters.
* Less now checks for the environment variable VISUAL before EDITOR.
* Ported to OS/2.
======================================================================
Major changes between "less" versions 237 and 252
* Changes in line-editing keys:
The literal key is now ^V or ^A rather than \ (backslash).
Filename completion commands (TAB and ^L) are disabled
when typing a search pattern.
* Line-editing command keys can be redefined using lesskey.
* Lesskey with no input file defaults to $HOME/.lesskey
rather than standard input.
* New option -V displays version number of less.
* New option -V displays version number of lesskey.
* Help file less.hlp is now installed by default in /usr/local/share
rather than /usr/local/lib.
======================================================================
Major changes between "less" versions 170 and 237
* By popular demand, text which matches the current search pattern
is highlighted. New -F flag disables this feature.
* Henry Spencer's regexp.c is now included, for systems which do not
have a regular expression library.
regexp.c is Copyright (c) 1986 by University of Toronto.
* New line-editing keys, including command history (arrow keys) and
filename completion (TAB).
* Input preprocessor allows modification of input files (e.g. uncompress)
via LESSOPEN/LESSCLOSE environment variables.
* New -X flag disables sending termcap "ti" and "te" (initialize and
deinitialize) strings to the terminal.
* Changing -i from within less now correctly affects a subsequent
repeated search.
* Searching for underlined or overstruck text now works when the -u
flag is in effect, rather than the -i flag.
* Use setlocale (LANG and LC_CTYPE environment variables) to determine
the character set if LESSCHARSET/LESSCHARDEF are not set.
* The default format for displaying binary characters is now standout
(reverse video) rather than blinking. This can still be changed by
setting the LESSBINFMT environment variable.
* Use autoconf installation technology.
* Ported to MS-DOS.
********************************
Things that may surprise you
********************************
* When you enter text at the bottom of the screen (search string,
filename, etc.), some keys act different than previously.
Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L
now have line editing functions.
* Some previous unofficial versions of less were able to display
compressed files. The new LESSOPEN/LESSCLOSE feature now provides
this functionality in a different way.
* Some previous unofficial versions of less provided a -Z flag to
set the number of lines of text to retain between full screen scrolls.
The -z-n flag (that is, -z with a negative number) provides this
functionality.
======================================================================
Major changes between "less" versions 123 and 170
* New option -j allows target lines to be positioned anywhere on screen.
* New option -S truncates displayed line at the screen width,
rather than wrapping onto the next line.
* New option -y limits amount of forward scroll.
* New option -T specifies a "tags" file.
* Non-printable, non-control characters are displayed in octal.
Such characters, as well as control characters, are displayed
in blinking mode.
* New command -+ sets an option to its default.
* New command -- sets an option to the opposite of its default.
* Lesskey file may have a string appended to a key's action,
which acts as though typed in after the command.
* New commands ESC-^F and ESC-^B match arbitrary types of brackets.
* New command F monitors a growing file (like "tail -f").
* New command | pipes a section of the input file into a shell command.
* New command :x directly jumps to a file in the command line list.
* Search commands have been enhanced and reorganized:
n Repeat search, same direction.
N Repeat search, opposite direction.
ESC-/ Search forward thru file boundaries
ESC-? Search backward thru file boundaries
ESC-n Repeat search thru file boundaries, same direction.
ESC-N Repeat search thru file boundaries, opposite direction.
Special character * causes search to search thru file boundaries.
Special character @ causes search to begin at start/end of file list.
* Examining a new file adds it to the command line list.
A list of files, or an expression which matches more than one file,
may be examined; all of them are added to the command line list.
* Environment variables LESSCHARSET and LESSCHARDEF can define
a non-ASCII character set.
* Partial support for MSDOS, including options -R for repainting screen
on quit, -v/-V to select video mode, and -W to change window size.
======================================================================
Major changes between "less" versions 97 and 123
* New option (-N) causes line numbers to be displayed in the
text of the file (like vi "set nu").
* New option (-?) prints help message immediately.
* New option (-r) displays "raw" control characters, without
mapping them to ^X notation.
* New option (-f) forces less to open non-regular files
(directories, etc).
* New option (-k) can be used to specify lesskey files by name.
* New option (-y) can be used to set a forward scroll limit
(like -h sets a backward scroll limit).
* File marks (set by the m command) are now preserved when a new
file is edited. The ' command can thus be used to switch files.
* New command ESC-/ searches all files (on the command line)
for a pattern.
* New command ESC-n repeats previous search, spanning files.
* The N command has been changed to repeat the previous search
in the reverse direction. The old N command is still available
via :n.
* New command ESC-N repeats previous search in the reverse
direction and spanning files.
* 8 bit characters are now supported. A new option (-g) can be
used to strip off the eighth bit (the previous behavior).
* Options which take a following string (like -t) may now
optionally have a space between the option letter and the string.
* Six new commands { } ( ) [ and ] can be used to match
brackets of specific types, similar to vi % command.
* New commands z and w move forward/backward one window and
simultaneously set the window size.
* Prompt string expansion now has %L for line number of the last
line in the file, and %E for the name of the editor.
Also, % escapes which refer to a line (b=bottom, t=top, etc.)
can use j for the jump target line.
* New environment variable LESSEDIT can be used to tailor the
command string passed to the editor by the v command.
* Examining a file which was previously examined will return
to the same position in the file.
* A "%" is expanded to the current filename and a "#" to the
previous filename, in both shell commands and the E command.
(Previously % worked only in shell commands and # worked
only in the E command.)
* New command ":ta" is equivalent to "-t".
* New command "s" is equivalent to "-l".
* The - command may be followed by "+X" to revert to the default
for option X, or "-X" to get the opposite of the default.
* Lesskey files may now include characters after the action as
extra input to be parsed after the action; for example:
"toggle-option X" to toggle a specific option X.