1 2 NEWS about less 3 4====================================================================== 5 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. 9 10 To report bugs, suggestions or comments, send email to bug-less@gnu.org 11 12====================================================================== 13 14 Major changes between "less" versions 530 and 551 15 16* Add --mouse option. 17 18* Add --wheel-lines option. 19 20* Add --no-histdups option. 21 22* Add --save-marks option. 23 24* Support PCRE2 regular expression library. 25 26* Redraw screen on SIGWINCH even if screen size doesn't change. 27 28* Shell-escape filenames in history so they can be used again. 29 30* Ring bell if user enters invalid long option name. 31 32* Use PCRE_UTF8 flag for pcre regular expressions when in UTF-8 mode. 33 34* Windows: use wide-char string to set console title. 35 36* Don't count lines in initial screen if using -X with -F. 37 38* Support mingw build system. 39 40* Fix bug in v command on empty file. 41 42* Fix bug in v command when filename contains shell metacharacters. 43 44====================================================================== 45 46 Major changes between "less" versions 487 and 530 47 48* Don't output terminal init sequence if using -F and file fits on one screen. 49 50* When using -S, mark truncated lines with a special character. 51 The character can be changed or disabled via the new --rscroll option. 52 53* New command M marks the last line displayed on the screen. 54 55* New command ESC-m removes a line mark. 56 57* Status column (enabled via -J) now shows mark letters. 58 59* Status column shows search matches even if highlighting is disabled via -G. 60 61* A second ESC-u command will clear search match markers in the status column. 62 63* Do same ANSI escape code filtering for tag matching that we do for 64 searching, to help when viewing syntax-highlighted code. 65 66* Catch SIGTERM and clean up before exiting. 67 68* Fix bug initializing default charset on Windows. 69 70* Handle keypad ENTER key correctly if it sends something other than newline. 71 72* Fix buffering bug when using stdin with a LESSOPEN pipe. 73 74* On Windows, allow 'u' in -D option to enable underlining. 75 76* On Windows, use underline in sgr mode. 77 78* On Windows, convert UTF-8 to multibyte if console is not UTF-8. 79 80* Update Unicode tables to 2017-03-08. 81 82* Pass-thru Unicode formating chars (Cf type) instead of treating them 83 as binary chars. But treat them as binary if -U is set. 84 85* Fix erroneous binary file warning when UTF-8 file contains ANSI SGR sequences. 86 87* Fix bugs when using LESSOPEN and switching between stdin and other files. 88 89* Fix some bugs handling filenames containing shell metacharacters. 90 91* Fix some memory leaks. 92 93* Allow some debugging environment variables to be set in lesskey file. 94 95* Code improvements: 96 . Use ANSI prototypes in funcs.h declarations. 97 . Fix some const mismatches. 98 . Remove archaic "register" in variable declarations. 99 100====================================================================== 101 102 Major changes between "less" versions 481 and 487 103 104* New commands ESC-{ and ESC-} to shift to start/end of displayed lines. 105 106* Make search highlights work correctly when changing caselessness with -i. 107 108* New option -Da in Windows version to enable SGR mode. 109 110* Fix "nothing to search" error when top or bottom line on screen is empty. 111 112* Fix bug when terminal has no "cm" termcap entry. 113 114* Fix incorrect display when entering double-width chars in search string. 115 116* Fix bug in Unicode handling that missed some double width characters. 117 118* Update Unicode database to 9.0.0. 119 120====================================================================== 121 122 Major changes between "less" versions 458 and 481 123 124* Don't overwrite history file; just append to it. 125 126* New command ESC-G goes to end of currently buffered data in a pipe. 127 128* Disable history feature when compiled with LESSHISTFILE set to "-". 129 130* In more-compatible mode, make the -p option apply to every file opened, 131 not just the first one. 132 133* In more-compatible mode, change the -e option to work like -E, not -EF. 134 135* Treat multiple CRs before LF are like one CR (all the CRs are hidden). 136 137* Allow "extra" string in lesskey file to append to a multi-char command 138 (like a search pattern), without executing the command. 139 140* Ignore -u/-U setting while viewing help file, so that 141 underline and bold chars are displayed correctly. 142 143* Improve detection of "binary" files in UTF-8 mode. 144 145* Fix bug with ++ commands. 146 147* Fix bug where prompt was sometimes not displayed with +G. 148 149* Fix possible memory corruption 150 151* Fix bugs and improve performance in ampersand filtering. 152 153* Automate construction of Unicode tables from Unicode database. 154 155* Allow %% escape sequence in LESSOPEN variable. 156 157====================================================================== 158 159 Major changes between "less" versions 451 and 458 160 161* Allow backslash escaping of metacharacters in LESS environment variable 162 after the --use-backslash option. 163 164* Don't quit if syntax errors are found in command line options. 165 166* Increase sizes of some internal buffers. 167 168* Fix configure bug with --with-regex=none. 169 170* Fix crash with "stty rows 0". 171 172* Fix Win32 attribute display bug. 173 174* Fix display bug when using up/down arrow on the command line. 175 176====================================================================== 177 178 Major changes between "less" versions 444 and 451 179 180* Add ESC-F command to keep reading data until a pattern is found. 181 182* Use exit code of LESSOPEN script if LESSOPEN starts with "||". 183 184* When up/down arrow is used on the command line immediately after 185 typing text, the next command starting with that text is found. 186 187* Add support for GNU regex. 188 189* Add configure option --with-regex=none and fix compile errors 190 when compiling with no regex library. 191 192* Fix bugs handling SGR sequences in Win32. 193 194* Fix possible crashes caused by malformed LESSOPEN or 195 LESSCLOSE variables. 196 197* Fix bug highlighting text which is discontiguous in the file 198 due to backspace processing. 199 200* Fix bug in displaying status column when scrolling backwards 201 with -J and -S in effect. 202 203====================================================================== 204 205 Major changes between "less" versions 443 and 444 206 207* Fix bug in unget handling that can cause strange effects on the 208 command line. 209 210* Remove vestiges of obsolete -l option that can cause a crash. 211 212====================================================================== 213 214 Major changes between "less" versions 436 and 443 215 216* Change search behavior such that when a search is given an explicit 217 pattern, the entire displayed screen is included in the search and 218 not just the portion after the target line. 219 220* Add -A option to change search behavior to the old way: only 221 the portion of the screen after the target line is searched. 222 223* Add %F formatting to prompt strings, replaced by the last component 224 of the input file. 225 226* Control-G while editing a command exits the command. 227 228* Less now exits with status 2 if control-C is pressed and -K is in effect. 229 230* Fix "ungetc overflow" when passing long commands via the -p option. 231 232* Fix bug in using line filtering via the & command 233 in combination with -i and -I. 234 235* Fix bug in handling negative arguments to the -j option. 236 237* Fix bug in handling %t in prompt strings. 238 239* Improve handling of long option names. 240 241* Improve percentage calculation for very large files. 242 243====================================================================== 244 245 Major changes between "less" versions 429 and 436 246 247* Don't pass "-" to non-pipe LESSOPEN unless it starts with "-". 248 249* Allow a fraction as the argument to the -# (--shift) option. 250 251* Fix highlight bug when underlined/overstruck text matches at end of line. 252 253* Fix non-regex searches with ctrl-R. 254 255====================================================================== 256 257 Major changes between "less" versions 424 and 429 258 259* LESSOPEN pipe will now be used on standard input, if the LESSOPEN 260 environment variable begins with "|-". 261 262* The -D option with one number now means use the normal background color. 263 264* Don't change permissions on history file if it is not a regular file. 265 266* Fix non-ANSI-compliant code that caused problems with some compilers. 267 268* Fix binary file detection in UTF-8 mode. 269 270* Fix display problems with long lines on "ignaw" terminals. 271 272* Fix problem interrupting the line number calculation for initial prompt. 273 274* Fix SGR emulation when dealing with multiple attributes (eg. bold+underline). 275 276* Fix highlight bug when searching for underlined/overstruck text. 277 278====================================================================== 279 280 Major changes between "less" versions 418 and 424 281 282* New "&" command allows filtering of lines based on a pattern. 283 284* Status column now displays a search match, even if the matched 285 string is scrolled off screen because -S is in effect. 286 287* Improve behavior of -F option. 288 289* Allow CSI character (0x9B) to work in UTF-8 mode. 290 291* Output carriage return at startup in case terminal doesn't default 292 to column 1. 293 294* Fix bug in '' (quote, quote) command after G command. 295 296====================================================================== 297 298 Major changes between "less" versions 416 and 418 299 300* Color escape sequences are now supported in WIN32 build. 301 302* Makefile now uses EXEEXT feature of autoconf. 303 304* Fix search bug when using -R and text contains ANSI color escape sequences. 305 306* Fix crash when using -r with UTF-8 text containing 0x9B bytes. 307 308* Fix display bug when using ' command to move less than one page forward. 309 310* Update GPL to version 3. 311 312====================================================================== 313 314 Major changes between "less" versions 409 and 416 315 316* New --follow-name option makes F command follow the name of a file 317 rather than the file descriptor if an open file is renamed. 318 319* Make searching with -i/-I work correctly with non-ASCII text. 320 321* Fix DJGPP build. 322 323====================================================================== 324 325 Major changes between "less" versions 406 and 409 326 327* Support CSI escape sequences, like SGR escape sequences. 328 329* Fix bug which caused screen to fail to repaint when window is resized. 330 331* Fix bug in using -i and -I flags with non-ASCII text. 332 333* Fix configure bug on systems which don't support langinfo.h. 334 335* Fix crash when searching text containing certain invalid UTF-8 sequences. 336 337====================================================================== 338 339 Major changes between "less" versions 394 and 406 340 341* Allow decimal point in number for % (percent) command. 342 343* Allow decimal point in number for -j option (fraction of screen height). 344 345* Make n command fetch previous pattern from history file on first search. 346 347* Don't rewrite history file if it has not changed. 348 349* Don't move to bottom of screen on first page. 350 351* Don't output extraneous newlines, so copy & pasting lines from the 352 output works better. 353 354* The -c option has been made identical with the -C option. 355 356* Allow "/dev/null" as synomym for "-" in LESSHISTFILE to indicate 357 that no history file should be used. 358 359* Search can now find text which follows a null byte, if the PCRE 360 library is used, or if no-regex searching (ctrl-R) is used. 361 362* Better compatibility with POSIX more specification. 363 364* Make -f work for directories. 365 366* Make "t" cmd traverse tags in the correct order. 367 368* Allow a few binary characters in the input file before warning 369 that the file is binary. 370 371* Don't warn that file is binary if it merely contains ANSI color sequences 372 and -R is in effect. 373 374* Update Unicode character tables. 375 376* Support DESTDIR in Makefile. 377 378* Fix bug when filename contains certain shell metacharacters such as "$". 379 380* Fix bug when resizing the window while waiting for input from a pipe. 381 382* Fix configure bugs. 383 384====================================================================== 385 386 Major changes between "less" versions 382 and 394 387 388* Add history file to save search and shell command history between 389 invocations of less. 390 391* Improve behavior of history list for search and shell commands. 392 393* Add -K (or --quit-on-intr) option to make less exit immediately on ctrl-C. 394 395* Improve handling of UTF-8 files and commands, including better 396 line wrapping and handling double-width chars. 397 398* Added LESSUTFBINFMT environment variable to control display of 399 non-printable characters in a UTF-8 file. 400 401* Add --with-secure option to configure, to make it easier to 402 build a secure version of less. 403 404* Show search matches in the status column even if search highlights 405 are disabled via the -G option or the ESC-u command. 406 407* Improve performance when the file contains very long lines. 408 409* Add "windows" charset. 410 411* Add man page for lessecho. 412 413* Add support for erase2 character, treated same as erase. 414 415* Use ASCII lowercase/uppercase logic when operating on the command line. 416 417* Update makefile for Borland C++ 5.5.1. 418 419* Fix bug in calculating number of pages for %D prompt. 420 421* Fix bug in handling tag file error. 422 423* Fix obscure bug if input file is deleted while viewing help. 424 425* Fix bug handling filenames which include square brackets. 426 427* Fix possible buffer overflow in "global" tag search. 428 429* Fix possible buffer overflow in usage of LESSOPEN and LESSCLOSE. 430 431* Fix buffer overflow in reverse search. 432 433====================================================================== 434 435 Major changes between "less" versions 381 and 382 436 437* Removed some old copyrighted code. 438 This probably breaks OS/9 support. 439 440====================================================================== 441 442 Major changes between "less" versions 378 and 381 443 444* New -L option to disable LESSOPEN processing. 445 446* Further support for large (64 bit) file addressing. 447 Large file support is now set up by the configure script. 448 449* Use autoconf 2.54. 450 Replace configure.in, acconfig.h, defines.h.top with configure.ac. 451 452* Overstriking underscore with underscore is now bold or underlined 453 depending on context. 454 455* Use only 7 spaces for line numbers in -N mode, if possible. 456 457* Fix some bugs in handling overstriking in UTF-8 files. 458 459* Fix some nroff issues in the man page. 460 461====================================================================== 462 463 Major changes between "less" versions 376 and 378 464 465* Bug fixes: 466 Default buffer space is now 64K as documented. 467 Search highlighting works properly when used with -R. 468 Windows version works properly when input file contains carriage returns. 469 Clean up some compiler warnings. 470 471====================================================================== 472 473 Major changes between "less" versions 358 and 376 474 475* -x option can now specify multiple variable-width tab stops. 476 477* -X option no longer disables keypad initialization. 478 New option --no-keypad disables keypad initialization. 479 480* New commands t and T step through multiple tag matches. 481 Added support for "global(1)" tags 482 (see http://www.gnu.org/software/global/global.html). 483 484* New prompt style set by option -Pw defines the message printed 485 while waiting for data in the F command. 486 487* System-wide lesskey file now defaults to sysless in etc directory 488 instead of .sysless in bin directory. 489 Use "configure --sysconfdir=..." to change it. 490 (For backwards compatibility, .sysless in bin is still recognized.) 491 492* Pressing RightArrow or LeftArrow while entering a number now shifts 493 the display N columns rather than editing the number itself. 494 495* Status column (enabled with -J) now shows search results. 496 497* Windows version sets window title. 498 499* Default LESSCHARSET for MS-DOS versions is now "dos". 500 501* Searching works better with ANSI (SGR) escape sequences. 502 ANSI color escape sequences are now supported in the MS-DOS (DJGPP) version. 503 504* Improved performance in reading very large pipes. 505 506* Eliminated some dependencies on file offets being 32 bits. 507 508* Fixed problems when viewing files with very long lines. 509 510* Fixed overstriking in UTF-8 mode, and overstriking tabs. 511 512* Improved horizontal shifting of text using -R option with ANSI color. 513 514* Improved handling of filenames containing shell metacharacters. 515 516* Some fixes for EBCDIC systems. 517 518* Some fixes for OS/2 systems. 519 520====================================================================== 521 522 Major changes between "less" versions 354 and 358 523 524* Add -J (--status-column) option to display a status column. 525 526* Add -# (--shift) option to set default horizontal shift distance. 527 Default horizontal shift distance is now one-half screen width. 528 529* Horizontal shifting does not shift line numbers if -N is in effect. 530 531* Horizontal shifting acts as though -S were set, to avoid confusion. 532 533====================================================================== 534 535 536 Major changes between "less" versions 352 and 354 537 538* Allow space after numeric-valued command line options. 539 540* Fix problem with configuring terminal libraries on some systems. 541 542* Add support for PCRE regular expression library. 543 544* Add --with-regex option to configure to allow manually selecting 545 a regular expression library. 546 547* Fix bug compiling with SECURE = 1. 548 549====================================================================== 550 551 552 Major changes between "less" versions 346 and 352 553 554* Enable UTF-8 if "UTF-8" appears in locale-related environment variables. 555 556* Add --with-editor option to configure script. 557 558* The -M prompt and = message now show the top and bottom line number. 559 560* Fix bug in running the editor on a file whose name contains quotes, etc. 561 562* Fix bug in horizontal scrolling of long lines. 563 564* Fix bug in doing :d on a file which contains marks. 565 566* Fix bug causing cleared lines to sometimes be filled with standout, 567 bold, underline, etc. on certain terminals. 568 569* Fixes for MS-DOS (DJGPP) version. 570 571====================================================================== 572 573 574 Major changes between "less" versions 340 and 346 575 576* The UTF-8 character set is now supported. 577 578* The default character set is now latin1 rather than ascii. 579 580* New option -R (--RAW-CONTROL-CHARS) is like -r but handles 581 long (wrapped) lines correctly, as long as the input contains only 582 normal text and ANSI color escape sequences. 583 584* New option -F (--quit-if-one-screen) quits if the text fits on 585 the first screen. 586 587* The -w option now highlights the target line of a g or p command. 588 589* A system-wide lesskey file is supported (LESSKEY_SYSTEM). 590 591* New escape for prompt strings: %c is replaced by column number. 592 593* New escape for prompt strings: %P is replaced by percentage into 594 file, based on line number rather than byte offset. 595 596* HOME and END keys now jump to beginning of file or end of file. 597 598====================================================================== 599 600 601 Major changes between "less" versions 337 and 340 602 603* Command line options for less may now be given in either the old 604 single-letter form, or a new long name form (--option-name). 605 See the less man page or "less --help" for the list of long option names. 606 607* Command line options for lesskey may now be given in a new long name 608 form. See the lesskey man page for the list of long option names. 609 610* New command -- toggles an option using the long option name. 611 612* New command __ queries an option using the long option name. 613 614* The old -- command is renamed as -!. 615 616* If a ^P is entered between the dash and the option letter of the - 617 command, the message describing the new setting is suppressed. 618 619* Lesskey files may now contain \k escape sequences to represent the 620 "special" keys (arrows, PAGE-UP/PAGE-DOWN, HOME, END, INSERT, DELETE). 621 622* New command :d removes the current file from the list of files. 623 624* New option -~ (like -w before version 335) 625 suppresses tildes after end-of-file. 626 627* Less is now released under the GNU General Public License. 628 629====================================================================== 630 631 632 Major changes between "less" versions 335 and 337 633 634* Fixed bugs in "make install". 635 636====================================================================== 637 638 639 Major changes between "less" versions 332 and 335 640 641* The old -w flag (suppress tildes after end-of-file) has been removed. 642 643* New -w flag highlights the first new line after a forward-screen. 644 645* New -W flag highlights the first new line after any forward movement. 646 647* Window resize works even if LINES and/or COLUMNS environment 648 variables are incorrect. 649 650* New percent escapes for prompt strings: 651 %d is replaced by the page number, and 652 %D is replaced by the number of pages in the file. 653 654* Added charsets "iso8859" and "ebcdic". 655 656* In Windows version, uses HOMEDRIVE and HOMEPATH if HOME is not defined. 657 658* Fixed some bugs causing incorrect display on DOS/Windows. 659 660====================================================================== 661 662 663 Major changes between "less" versions 330 and 332 664 665* Filenames from the command line are entered into the command history, 666 so UPARROW/DOWNARROW can be used to retrieve them from the :e command. 667 668* Now works correctly on Windows when using a scrolling terminal 669 window (buffer larger than display window). 670 671* On Windows, now restores the console screen on exit. 672 Use -X to get the old behavior. 673 674* Fixed bug on Windows when CAPS-LOCK or NUM-LOCK is pressed. 675 676* Fixed bug on Windows when piping output of an interactive program. 677 678* Fixed bug in tags file processing when tags file has DOS-style 679 line terminators (CR/LF). 680 681* Fixed compilation problem on OS/2. 682 683====================================================================== 684 685 686 Major changes between "less" versions 321 and 330 687 688* Now supports filenames containing spaces (in double quotes). 689 New option -" can be used to change the quoting characters. 690 691* In filename completion, a slash is appended to a directory name. 692 If the environment variable LESSSEPARATOR is set, the value of 693 that variable, rather than a slash, is appended. 694 695* LeftArrow and RightArrow are same as ESC-[ and ESC-]. 696 697* Added commands ESC-( and ESC-), same as ESC-[ and ESC-]. 698 699* A "quit" command defined in a lesskey file may now have an "extra" 700 string, which is used to return an exit code from less when it quits. 701 702* New environment variables LESSMETACHARS and LESSMETAESCAPE provide 703 more control over how less interfaces to the shell. 704 705* Ported to Microsoft Visual C compiler for Windows. 706 707* Ported to DJGPP compiler for MS-DOS. 708 709* Bug fixes. 710 711====================================================================== 712 713 714 Major changes between "less" versions 291 and 321 715 716* Command line at bottom of screen now scrolls, so it can be longer 717 than the screen width. 718 719* New commands ESC-] and ESC-[ scroll the display horizontally. 720 721* New command ESC-SPACE scrolls forward a full screen, even if it 722 hits end-of-file. 723 724* Alternate modifiers for search commands: ^N is same as !, 725 ^F is same as @, and ^E is same as *. 726 727* New modifier for search commands: ^K means highlight the matches 728 currently on-screen, but don't move to the first match. 729 730* New modifier for search commands: ^R means don't use regular 731 expressions in the search. 732 733* Environment variable LESSKEY gives name of default lesskey file. 734 735* Environment variable LESSSECURE will force less to run in 736 "secure" mode. 737 738* Command line argument "--" signals that the rest of the arguments 739 are files (not option flags). 740 741* Help file (less.hlp) is no longer installed. Help text is now 742 embedded in the less executable itself. 743 744* Added -Ph to change the prompt for the help text. 745 Added -Ps to change the default short prompt (same as plain -P). 746 747* Ported to the Borland C compiler for MS-DOS. 748 749* Ported to Windows 95 & Windows NT. 750 751* Ported to OS-9. 752 753* Ported to GNU Hurd. 754 755====================================================================== 756 757 758 Major changes between "less" versions 290 and 291 759 760* Less environment variables can be specified in lesskey files. 761 762* Fixed MS-DOS build. 763 764====================================================================== 765 766 767 Major changes between "less" versions 278 and 290 768 769* Accepts GNU-style options "--help" and "--version". 770 771* OS/2 version looks for less.ini in $HOME before $INIT and $PATH. 772 773* Bug fixes 774 775====================================================================== 776 777 778 Major changes between "less" versions 252 and 278 779 780* A LESSOPEN preprocessor may now pipe the converted file data to less, 781 rather than writing it to a temporary file. 782 783* Search pattern highlighting has been fixed. It now highlights 784 reliably, even if a string is split across two screen lines, 785 contains TABs, etc. 786 787* The -F flag (which suppress search highlighting) has been changed 788 to -G. A new flag, -g, changes search highlighting to highlight 789 only the string found by the last search command, instead of all 790 strings which match the last search command. 791 792* New flag -I acts like -i, but ignores case even if the search 793 pattern contains uppercase letters. 794 795* Less now checks for the environment variable VISUAL before EDITOR. 796 797* Ported to OS/2. 798 799====================================================================== 800 801 802 Major changes between "less" versions 237 and 252 803 804* Changes in line-editing keys: 805 The literal key is now ^V or ^A rather than \ (backslash). 806 Filename completion commands (TAB and ^L) are disabled 807 when typing a search pattern. 808 809* Line-editing command keys can be redefined using lesskey. 810 811* Lesskey with no input file defaults to $HOME/.lesskey 812 rather than standard input. 813 814* New option -V displays version number of less. 815 816* New option -V displays version number of lesskey. 817 818* Help file less.hlp is now installed by default in /usr/local/share 819 rather than /usr/local/lib. 820 821 822====================================================================== 823 824 825 Major changes between "less" versions 170 and 237 826 827* By popular demand, text which matches the current search pattern 828 is highlighted. New -F flag disables this feature. 829 830* Henry Spencer's regexp.c is now included, for systems which do not 831 have a regular expression library. 832 regexp.c is Copyright (c) 1986 by University of Toronto. 833 834* New line-editing keys, including command history (arrow keys) and 835 filename completion (TAB). 836 837* Input preprocessor allows modification of input files (e.g. uncompress) 838 via LESSOPEN/LESSCLOSE environment variables. 839 840* New -X flag disables sending termcap "ti" and "te" (initialize and 841 deinitialize) strings to the terminal. 842 843* Changing -i from within less now correctly affects a subsequent 844 repeated search. 845 846* Searching for underlined or overstruck text now works when the -u 847 flag is in effect, rather than the -i flag. 848 849* Use setlocale (LANG and LC_CTYPE environment variables) to determine 850 the character set if LESSCHARSET/LESSCHARDEF are not set. 851 852* The default format for displaying binary characters is now standout 853 (reverse video) rather than blinking. This can still be changed by 854 setting the LESSBINFMT environment variable. 855 856* Use autoconf installation technology. 857 858* Ported to MS-DOS. 859 860 ******************************** 861 Things that may surprise you 862 ******************************** 863 864* When you enter text at the bottom of the screen (search string, 865 filename, etc.), some keys act different than previously. 866 Specifically, \ (backslash), ESC, TAB, BACKTAB, and control-L 867 now have line editing functions. 868 869* Some previous unofficial versions of less were able to display 870 compressed files. The new LESSOPEN/LESSCLOSE feature now provides 871 this functionality in a different way. 872 873* Some previous unofficial versions of less provided a -Z flag to 874 set the number of lines of text to retain between full screen scrolls. 875 The -z-n flag (that is, -z with a negative number) provides this 876 functionality. 877 878 879====================================================================== 880 881 882 Major changes between "less" versions 123 and 170 883 884* New option -j allows target lines to be positioned anywhere on screen. 885 886* New option -S truncates displayed line at the screen width, 887 rather than wrapping onto the next line. 888 889* New option -y limits amount of forward scroll. 890 891* New option -T specifies a "tags" file. 892 893* Non-printable, non-control characters are displayed in octal. 894 Such characters, as well as control characters, are displayed 895 in blinking mode. 896 897* New command -+ sets an option to its default. 898* New command -- sets an option to the opposite of its default. 899 900* Lesskey file may have a string appended to a key's action, 901 which acts as though typed in after the command. 902 903* New commands ESC-^F and ESC-^B match arbitrary types of brackets. 904 905* New command F monitors a growing file (like "tail -f"). 906 907* New command | pipes a section of the input file into a shell command. 908 909* New command :x directly jumps to a file in the command line list. 910 911* Search commands have been enhanced and reorganized: 912 n Repeat search, same direction. 913 N Repeat search, opposite direction. 914 ESC-/ Search forward thru file boundaries 915 ESC-? Search backward thru file boundaries 916 ESC-n Repeat search thru file boundaries, same direction. 917 ESC-N Repeat search thru file boundaries, opposite direction. 918 Special character * causes search to search thru file boundaries. 919 Special character @ causes search to begin at start/end of file list. 920 921* Examining a new file adds it to the command line list. 922 A list of files, or an expression which matches more than one file, 923 may be examined; all of them are added to the command line list. 924 925* Environment variables LESSCHARSET and LESSCHARDEF can define 926 a non-ASCII character set. 927 928* Partial support for MSDOS, including options -R for repainting screen 929 on quit, -v/-V to select video mode, and -W to change window size. 930 931 932====================================================================== 933 934 935 Major changes between "less" versions 97 and 123 936 937* New option (-N) causes line numbers to be displayed in the 938 text of the file (like vi "set nu"). 939 940* New option (-?) prints help message immediately. 941 942* New option (-r) displays "raw" control characters, without 943 mapping them to ^X notation. 944 945* New option (-f) forces less to open non-regular files 946 (directories, etc). 947 948* New option (-k) can be used to specify lesskey files by name. 949 950* New option (-y) can be used to set a forward scroll limit 951 (like -h sets a backward scroll limit). 952 953* File marks (set by the m command) are now preserved when a new 954 file is edited. The ' command can thus be used to switch files. 955 956* New command ESC-/ searches all files (on the command line) 957 for a pattern. 958 959* New command ESC-n repeats previous search, spanning files. 960 961* The N command has been changed to repeat the previous search 962 in the reverse direction. The old N command is still available 963 via :n. 964 965* New command ESC-N repeats previous search in the reverse 966 direction and spanning files. 967 968* 8 bit characters are now supported. A new option (-g) can be 969 used to strip off the eighth bit (the previous behavior). 970 971* Options which take a following string (like -t) may now 972 optionally have a space between the option letter and the string. 973 974* Six new commands { } ( ) [ and ] can be used to match 975 brackets of specific types, similar to vi % command. 976 977* New commands z and w move forward/backward one window and 978 simultaneously set the window size. 979 980* Prompt string expansion now has %L for line number of the last 981 line in the file, and %E for the name of the editor. 982 Also, % escapes which refer to a line (b=bottom, t=top, etc.) 983 can use j for the jump target line. 984 985* New environment variable LESSEDIT can be used to tailor the 986 command string passed to the editor by the v command. 987 988* Examining a file which was previously examined will return 989 to the same position in the file. 990 991* A "%" is expanded to the current filename and a "#" to the 992 previous filename, in both shell commands and the E command. 993 (Previously % worked only in shell commands and # worked 994 only in the E command.) 995 996* New command ":ta" is equivalent to "-t". 997 998* New command "s" is equivalent to "-l". 999 1000* The - command may be followed by "+X" to revert to the default 1001 for option X, or "-X" to get the opposite of the default. 1002 1003* Lesskey files may now include characters after the action as 1004 extra input to be parsed after the action; for example: 1005 "toggle-option X" to toggle a specific option X. 1006 1007 1008 1009 1010 1011