Annotation of src/usr.bin/less/less.man, Revision 1.1.1.2
1.1.1.2 ! shadchin 1: LESS(1) LESS(1)
1.1 etheisen 2:
3:
4:
1.1.1.2 ! shadchin 5: [1mNAME[0m
! 6: less - opposite of more
1.1 etheisen 7:
1.1.1.2 ! shadchin 8: [1mSYNOPSIS[0m
! 9: [1mless -?[0m
! 10: [1mless --help[0m
! 11: [1mless -V[0m
! 12: [1mless --version[0m
! 13: [1mless [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~][0m
! 14: [1m[-b [4m[22mspace[24m[1m] [-h [4m[22mlines[24m[1m] [-j [4m[22mline[24m[1m] [-k [4m[22mkeyfile[24m[1m][0m
! 15: [1m[-{oO} [4m[22mlogfile[24m[1m] [-p [4m[22mpattern[24m[1m] [-P [4m[22mprompt[24m[1m] [-t [4m[22mtag[24m[1m][0m
! 16: [1m[-T [4m[22mtagsfile[24m[1m] [-x [4m[22mtab[24m[1m,...] [-y [4m[22mlines[24m[1m] [-[z] [4m[22mlines[24m[1m][0m
! 17: [1m[-# [4m[22mshift[24m[1m] [+[+][4m[22mcmd[24m[1m] [--] [[4m[22mfilename[24m[1m]...[0m
! 18: (See the OPTIONS section for alternate option syntax with long option
! 19: names.)
! 20:
! 21:
! 22: [1mDESCRIPTION[0m
! 23: [4mLess[24m is a program similar to [4mmore[24m (1), but which allows backward move-
! 24: ment in the file as well as forward movement. Also, [4mless[24m does not have
! 25: to read the entire input file before starting, so with large input
! 26: files it starts up faster than text editors like [4mvi[24m (1). [4mLess[24m uses
! 27: termcap (or terminfo on some systems), so it can run on a variety of
! 28: terminals. There is even limited support for hardcopy terminals. (On
! 29: a hardcopy terminal, lines which should be printed at the top of the
! 30: screen are prefixed with a caret.)
! 31:
! 32: Commands are based on both [4mmore[24m and [4mvi.[24m Commands may be preceded by a
! 33: decimal number, called N in the descriptions below. The number is used
! 34: by some commands, as indicated.
! 35:
! 36:
! 37: [1mCOMMANDS[0m
! 38: In the following descriptions, ^X means control-X. ESC stands for the
! 39: ESCAPE key; for example ESC-v means the two character sequence
! 40: "ESCAPE", then "v".
! 41:
! 42: h or H Help: display a summary of these commands. If you forget all
! 43: the other commands, remember this one.
! 44:
! 45: SPACE or ^V or f or ^F
! 46: Scroll forward N lines, default one window (see option -z
! 47: below). If N is more than the screen size, only the final
! 48: screenful is displayed. Warning: some systems use ^V as a spe-
! 49: cial literalization character.
! 50:
! 51: z Like SPACE, but if N is specified, it becomes the new window
! 52: size.
! 53:
! 54: ESC-SPACE
! 55: Like SPACE, but scrolls a full screenful, even if it reaches
! 56: end-of-file in the process.
! 57:
! 58: ENTER or RETURN or ^N or e or ^E or j or ^J
! 59: Scroll forward N lines, default 1. The entire N lines are dis-
! 60: played, even if N is more than the screen size.
! 61:
! 62: d or ^D
! 63: Scroll forward N lines, default one half of the screen size. If
! 64: N is specified, it becomes the new default for subsequent d and
! 65: u commands.
! 66:
! 67: b or ^B or ESC-v
! 68: Scroll backward N lines, default one window (see option -z
! 69: below). If N is more than the screen size, only the final
! 70: screenful is displayed.
! 71:
! 72: w Like ESC-v, but if N is specified, it becomes the new window
! 73: size.
! 74:
! 75: y or ^Y or ^P or k or ^K
! 76: Scroll backward N lines, default 1. The entire N lines are dis-
! 77: played, even if N is more than the screen size. Warning: some
! 78: systems use ^Y as a special job control character.
! 79:
! 80: u or ^U
! 81: Scroll backward N lines, default one half of the screen size.
! 82: If N is specified, it becomes the new default for subsequent d
! 83: and u commands.
! 84:
! 85: ESC-) or RIGHTARROW
! 86: Scroll horizontally right N characters, default half the screen
! 87: width (see the -# option). If a number N is specified, it
! 88: becomes the default for future RIGHTARROW and LEFTARROW com-
! 89: mands. While the text is scrolled, it acts as though the -S
! 90: option (chop lines) were in effect.
! 91:
! 92: ESC-( or LEFTARROW
! 93: Scroll horizontally left N characters, default half the screen
! 94: width (see the -# option). If a number N is specified, it
! 95: becomes the default for future RIGHTARROW and LEFTARROW com-
! 96: mands.
! 97:
! 98: r or ^R or ^L
! 99: Repaint the screen.
! 100:
! 101: R Repaint the screen, discarding any buffered input. Useful if
! 102: the file is changing while it is being viewed.
! 103:
! 104: F Scroll forward, and keep trying to read when the end of file is
! 105: reached. Normally this command would be used when already at
! 106: the end of the file. It is a way to monitor the tail of a file
! 107: which is growing while it is being viewed. (The behavior is
! 108: similar to the "tail -f" command.)
! 109:
! 110: g or < or ESC-<
! 111: Go to line N in the file, default 1 (beginning of file). (Warn-
! 112: ing: this may be slow if N is large.)
! 113:
! 114: G or > or ESC->
! 115: Go to line N in the file, default the end of the file. (Warn-
! 116: ing: this may be slow if N is large, or if N is not specified
! 117: and standard input, rather than a file, is being read.)
! 118:
! 119: p or % Go to a position N percent into the file. N should be between 0
! 120: and 100, and may contain a decimal point.
! 121:
! 122: P Go to the line containing byte offset N in the file.
! 123:
! 124: { If a left curly bracket appears in the top line displayed on the
! 125: screen, the { command will go to the matching right curly
! 126: bracket. The matching right curly bracket is positioned on the
! 127: bottom line of the screen. If there is more than one left curly
! 128: bracket on the top line, a number N may be used to specify the
! 129: N-th bracket on the line.
! 130:
! 131: } If a right curly bracket appears in the bottom line displayed on
! 132: the screen, the } command will go to the matching left curly
! 133: bracket. The matching left curly bracket is positioned on the
! 134: top line of the screen. If there is more than one right curly
! 135: bracket on the top line, a number N may be used to specify the
! 136: N-th bracket on the line.
! 137:
! 138: ( Like {, but applies to parentheses rather than curly brackets.
! 139:
! 140: ) Like }, but applies to parentheses rather than curly brackets.
! 141:
! 142: [ Like {, but applies to square brackets rather than curly brack-
! 143: ets.
! 144:
! 145: ] Like }, but applies to square brackets rather than curly brack-
! 146: ets.
! 147:
! 148: ESC-^F Followed by two characters, acts like {, but uses the two char-
! 149: acters as open and close brackets, respectively. For example,
! 150: "ESC ^F < >" could be used to go forward to the > which matches
! 151: the < in the top displayed line.
! 152:
! 153: ESC-^B Followed by two characters, acts like }, but uses the two char-
! 154: acters as open and close brackets, respectively. For example,
! 155: "ESC ^B < >" could be used to go backward to the < which matches
! 156: the > in the bottom displayed line.
! 157:
! 158: m Followed by any lowercase letter, marks the current position
! 159: with that letter.
! 160:
! 161: ' (Single quote.) Followed by any lowercase letter, returns to
! 162: the position which was previously marked with that letter. Fol-
! 163: lowed by another single quote, returns to the position at which
! 164: the last "large" movement command was executed. Followed by a ^
! 165: or $, jumps to the beginning or end of the file respectively.
! 166: Marks are preserved when a new file is examined, so the ' com-
! 167: mand can be used to switch between input files.
! 168:
! 169: ^X^X Same as single quote.
! 170:
! 171: /pattern
! 172: Search forward in the file for the N-th line containing the pat-
! 173: tern. N defaults to 1. The pattern is a regular expression, as
! 174: recognized by the regular expression library supplied by your
! 175: system. The search starts at the first line displayed (but see
! 176: the -a and -j options, which change this).
! 177:
! 178: Certain characters are special if entered at the beginning of
! 179: the pattern; they modify the type of search rather than become
! 180: part of the pattern:
! 181:
! 182: ^N or !
! 183: Search for lines which do NOT match the pattern.
! 184:
! 185: ^E or *
! 186: Search multiple files. That is, if the search reaches
! 187: the END of the current file without finding a match, the
! 188: search continues in the next file in the command line
! 189: list.
! 190:
! 191: ^F or @
! 192: Begin the search at the first line of the FIRST file in
! 193: the command line list, regardless of what is currently
! 194: displayed on the screen or the settings of the -a or -j
! 195: options.
! 196:
! 197: ^K Highlight any text which matches the pattern on the cur-
! 198: rent screen, but don't move to the first match (KEEP cur-
! 199: rent position).
! 200:
! 201: ^R Don't interpret regular expression metacharacters; that
! 202: is, do a simple textual comparison.
! 203:
! 204: ?pattern
! 205: Search backward in the file for the N-th line containing the
! 206: pattern. The search starts at the line immediately before the
! 207: top line displayed.
! 208:
! 209: Certain characters are special as in the / command:
! 210:
! 211: ^N or !
! 212: Search for lines which do NOT match the pattern.
! 213:
! 214: ^E or *
! 215: Search multiple files. That is, if the search reaches
! 216: the beginning of the current file without finding a
! 217: match, the search continues in the previous file in the
! 218: command line list.
! 219:
! 220: ^F or @
! 221: Begin the search at the last line of the last file in the
! 222: command line list, regardless of what is currently dis-
! 223: played on the screen or the settings of the -a or -j
! 224: options.
! 225:
! 226: ^K As in forward searches.
! 227:
! 228: ^R As in forward searches.
! 229:
! 230: ESC-/pattern
! 231: Same as "/*".
! 232:
! 233: ESC-?pattern
! 234: Same as "?*".
! 235:
! 236: n Repeat previous search, for N-th line containing the last pat-
! 237: tern. If the previous search was modified by ^N, the search is
! 238: made for the N-th line NOT containing the pattern. If the pre-
! 239: vious search was modified by ^E, the search continues in the
! 240: next (or previous) file if not satisfied in the current file.
! 241: If the previous search was modified by ^R, the search is done
! 242: without using regular expressions. There is no effect if the
! 243: previous search was modified by ^F or ^K.
! 244:
! 245: N Repeat previous search, but in the reverse direction.
! 246:
! 247: ESC-n Repeat previous search, but crossing file boundaries. The
! 248: effect is as if the previous search were modified by *.
! 249:
! 250: ESC-N Repeat previous search, but in the reverse direction and cross-
! 251: ing file boundaries.
! 252:
! 253: ESC-u Undo search highlighting. Turn off highlighting of strings
! 254: matching the current search pattern. If highlighting is already
! 255: off because of a previous ESC-u command, turn highlighting back
! 256: on. Any search command will also turn highlighting back on.
! 257: (Highlighting can also be disabled by toggling the -G option; in
! 258: that case search commands do not turn highlighting back on.)
! 259:
! 260: &pattern
! 261: Display only lines which match the pattern; lines which do not
! 262: match the pattern are not displayed. If pattern is empty (if
! 263: you type & immediately followed by ENTER), any filtering is
! 264: turned off, and all lines are displayed. While filtering is in
! 265: effect, an ampersand is displayed at the beginning of the
! 266: prompt, as a reminder that some lines in the file may be hidden.
! 267:
! 268: Certain characters are special as in the / command:
! 269:
! 270: ^N or !
! 271: Display only lines which do NOT match the pattern.
! 272:
! 273: ^R Don't interpret regular expression metacharacters; that
! 274: is, do a simple textual comparison.
! 275:
! 276: :e [filename]
! 277: Examine a new file. If the filename is missing, the "current"
! 278: file (see the :n and :p commands below) from the list of files
! 279: in the command line is re-examined. A percent sign (%) in the
! 280: filename is replaced by the name of the current file. A pound
! 281: sign (#) is replaced by the name of the previously examined
! 282: file. However, two consecutive percent signs are simply
! 283: replaced with a single percent sign. This allows you to enter a
! 284: filename that contains a percent sign in the name. Similarly,
! 285: two consecutive pound signs are replaced with a single pound
! 286: sign. The filename is inserted into the command line list of
! 287: files so that it can be seen by subsequent :n and :p commands.
! 288: If the filename consists of several files, they are all inserted
! 289: into the list of files and the first one is examined. If the
! 290: filename contains one or more spaces, the entire filename should
! 291: be enclosed in double quotes (also see the -" option).
! 292:
! 293: ^X^V or E
! 294: Same as :e. Warning: some systems use ^V as a special literal-
! 295: ization character. On such systems, you may not be able to use
! 296: ^V.
! 297:
! 298: :n Examine the next file (from the list of files given in the com-
! 299: mand line). If a number N is specified, the N-th next file is
! 300: examined.
! 301:
! 302: :p Examine the previous file in the command line list. If a number
! 303: N is specified, the N-th previous file is examined.
! 304:
! 305: :x Examine the first file in the command line list. If a number N
! 306: is specified, the N-th file in the list is examined.
! 307:
! 308: :d Remove the current file from the list of files.
! 309:
! 310: t Go to the next tag, if there were more than one matches for the
! 311: current tag. See the -t option for more details about tags.
! 312:
! 313: T Go to the previous tag, if there were more than one matches for
! 314: the current tag.
! 315:
! 316: = or ^G or :f
! 317: Prints some information about the file being viewed, including
! 318: its name and the line number and byte offset of the bottom line
! 319: being displayed. If possible, it also prints the length of the
! 320: file, the number of lines in the file and the percent of the
! 321: file above the last displayed line.
! 322:
! 323: - Followed by one of the command line option letters (see OPTIONS
! 324: below), this will change the setting of that option and print a
! 325: message describing the new setting. If a ^P (CONTROL-P) is
! 326: entered immediately after the dash, the setting of the option is
! 327: changed but no message is printed. If the option letter has a
! 328: numeric value (such as -b or -h), or a string value (such as -P
! 329: or -t), a new value may be entered after the option letter. If
! 330: no new value is entered, a message describing the current set-
! 331: ting is printed and nothing is changed.
! 332:
! 333: -- Like the - command, but takes a long option name (see OPTIONS
! 334: below) rather than a single option letter. You must press ENTER
! 335: or RETURN after typing the option name. A ^P immediately after
! 336: the second dash suppresses printing of a message describing the
! 337: new setting, as in the - command.
! 338:
! 339: -+ Followed by one of the command line option letters this will
! 340: reset the option to its default setting and print a message
! 341: describing the new setting. (The "-+[4mX[24m" command does the same
! 342: thing as "-+[4mX[24m" on the command line.) This does not work for
! 343: string-valued options.
! 344:
! 345: --+ Like the -+ command, but takes a long option name rather than a
! 346: single option letter.
! 347:
! 348: -! Followed by one of the command line option letters, this will
! 349: reset the option to the "opposite" of its default setting and
! 350: print a message describing the new setting. This does not work
! 351: for numeric or string-valued options.
! 352:
! 353: --! Like the -! command, but takes a long option name rather than a
! 354: single option letter.
! 355:
! 356: _ (Underscore.) Followed by one of the command line option let-
! 357: ters, this will print a message describing the current setting
! 358: of that option. The setting of the option is not changed.
! 359:
! 360: __ (Double underscore.) Like the _ (underscore) command, but takes
! 361: a long option name rather than a single option letter. You must
! 362: press ENTER or RETURN after typing the option name.
! 363:
! 364: +cmd Causes the specified cmd to be executed each time a new file is
! 365: examined. For example, +G causes [4mless[24m to initially display each
! 366: file starting at the end rather than the beginning.
! 367:
! 368: V Prints the version number of [4mless[24m being run.
! 369:
! 370: q or Q or :q or :Q or ZZ
! 371: Exits [4mless.[0m
! 372:
! 373: The following four commands may or may not be valid, depending on your
! 374: particular installation.
! 375:
! 376: v Invokes an editor to edit the current file being viewed. The
! 377: editor is taken from the environment variable VISUAL if defined,
! 378: or EDITOR if VISUAL is not defined, or defaults to "vi" if nei-
! 379: ther VISUAL nor EDITOR is defined. See also the discussion of
! 380: LESSEDIT under the section on PROMPTS below.
! 381:
! 382: ! shell-command
! 383: Invokes a shell to run the shell-command given. A percent sign
! 384: (%) in the command is replaced by the name of the current file.
! 385: A pound sign (#) is replaced by the name of the previously exam-
! 386: ined file. "!!" repeats the last shell command. "!" with no
! 387: shell command simply invokes a shell. On Unix systems, the
! 388: shell is taken from the environment variable SHELL, or defaults
! 389: to "sh". On MS-DOS and OS/2 systems, the shell is the normal
! 390: command processor.
! 391:
! 392: | <m> shell-command
! 393: <m> represents any mark letter. Pipes a section of the input
! 394: file to the given shell command. The section of the file to be
! 395: piped is between the first line on the current screen and the
! 396: position marked by the letter. <m> may also be ^ or $ to indi-
! 397: cate beginning or end of file respectively. If <m> is . or new-
! 398: line, the current screen is piped.
! 399:
! 400: s filename
! 401: Save the input to a file. This only works if the input is a
! 402: pipe, not an ordinary file.
! 403:
! 404: [1mOPTIONS[0m
! 405: Command line options are described below. Most options may be changed
! 406: while [4mless[24m is running, via the "-" command.
! 407:
! 408: Most options may be given in one of two forms: either a dash followed
! 409: by a single letter, or two dashes followed by a long option name. A
! 410: long option name may be abbreviated as long as the abbreviation is
! 411: unambiguous. For example, --quit-at-eof may be abbreviated --quit, but
! 412: not --qui, since both --quit-at-eof and --quiet begin with --qui. Some
! 413: long option names are in uppercase, such as --QUIT-AT-EOF, as distinct
! 414: from --quit-at-eof. Such option names need only have their first let-
! 415: ter capitalized; the remainder of the name may be in either case. For
! 416: example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
! 417:
! 418: Options are also taken from the environment variable "LESS". For exam-
! 419: ple, to avoid typing "less -options ..." each time [4mless[24m is invoked, you
! 420: might tell [4mcsh:[0m
! 421:
! 422: setenv LESS "-options"
! 423:
! 424: or if you use [4msh:[0m
! 425:
! 426: LESS="-options"; export LESS
! 427:
! 428: On MS-DOS, you don't need the quotes, but you should replace any per-
! 429: cent signs in the options string by double percent signs.
! 430:
! 431: The environment variable is parsed before the command line, so command
! 432: line options override the LESS environment variable. If an option
! 433: appears in the LESS variable, it can be reset to its default value on
! 434: the command line by beginning the command line option with "-+".
! 435:
! 436: For options like -P or -D which take a following string, a dollar sign
! 437: ($) must be used to signal the end of the string. For example, to set
! 438: two -D options on MS-DOS, you must have a dollar sign between them,
! 439: like this:
! 440:
! 441: LESS="-Dn9.1$-Ds4.1"
! 442:
! 443:
! 444: -? or --help
! 445: This option displays a summary of the commands accepted by [4mless[0m
! 446: (the same as the h command). (Depending on how your shell
! 447: interprets the question mark, it may be necessary to quote the
! 448: question mark, thus: "-\?".)
! 449:
! 450: -a or --search-skip-screen
! 451: By default, forward searches start at the top of the displayed
! 452: screen and backwards searches start at the bottom of the dis-
! 453: played screen (except for repeated searches invoked by the n or
! 454: N commands, which start after or before the "target" line
! 455: respectively; see the -j option for more about the target line).
! 456: The -a option causes forward searches to instead start at the
! 457: bottom of the screen and backward searches to start at the top
! 458: of the screen, thus skipping all lines displayed on the screen.
! 459:
! 460: -A or --SEARCH-SKIP-SCREEN
! 461: Causes all forward searches (not just non-repeated searches) to
! 462: start just after the target line, and all backward searches to
! 463: start just before the target line. Thus, forward searches will
! 464: skip part of the displayed screen (from the first line up to and
! 465: including the target line). Similarly backwards searches will
! 466: skip the displayed screen from the last line up to and including
! 467: the target line. This was the default behavior in less versions
! 468: prior to 441.
! 469:
! 470: -b[4mn[24m or --buffers=[4mn[0m
! 471: Specifies the amount of buffer space [4mless[24m will use for each
! 472: file, in units of kilobytes (1024 bytes). By default 64K of
! 473: buffer space is used for each file (unless the file is a pipe;
! 474: see the -B option). The -b option specifies instead that [4mn[0m
! 475: kilobytes of buffer space should be used for each file. If [4mn[24m is
! 476: -1, buffer space is unlimited; that is, the entire file can be
! 477: read into memory.
! 478:
! 479: -B or --auto-buffers
! 480: By default, when data is read from a pipe, buffers are allocated
! 481: automatically as needed. If a large amount of data is read from
! 482: the pipe, this can cause a large amount of memory to be allo-
! 483: cated. The -B option disables this automatic allocation of buf-
! 484: fers for pipes, so that only 64K (or the amount of space speci-
! 485: fied by the -b option) is used for the pipe. Warning: use of -B
! 486: can result in erroneous display, since only the most recently
! 487: viewed part of the piped data is kept in memory; any earlier
! 488: data is lost.
! 489:
! 490: -c or --clear-screen
! 491: Causes full screen repaints to be painted from the top line
! 492: down. By default, full screen repaints are done by scrolling
! 493: from the bottom of the screen.
! 494:
! 495: -C or --CLEAR-SCREEN
! 496: Same as -c, for compatibility with older versions of [4mless.[0m
! 497:
! 498: -d or --dumb
! 499: The -d option suppresses the error message normally displayed if
! 500: the terminal is dumb; that is, lacks some important capability,
! 501: such as the ability to clear the screen or scroll backward. The
! 502: -d option does not otherwise change the behavior of [4mless[24m on a
! 503: dumb terminal.
! 504:
! 505: -D[1mx[4m[22mcolor[24m or --color=[1mx[4m[22mcolor[0m
! 506: [MS-DOS only] Sets the color of the text displayed. [1mx [22mis a sin-
! 507: gle character which selects the type of text whose color is
! 508: being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
! 509: [4mcolor[24m is a pair of numbers separated by a period. The first
! 510: number selects the foreground color and the second selects the
! 511: background color of the text. A single number [4mN[24m is the same as
! 512: [4mN.M[24m, where [4mM[24m is the normal background color.
! 513:
! 514:
! 515: -e or --quit-at-eof
! 516: Causes [4mless[24m to automatically exit the second time it reaches
! 517: end-of-file. By default, the only way to exit [4mless[24m is via the
! 518: "q" command.
! 519:
! 520: -E or --QUIT-AT-EOF
! 521: Causes [4mless[24m to automatically exit the first time it reaches end-
! 522: of-file.
! 523:
! 524: -f or --force
! 525: Forces non-regular files to be opened. (A non-regular file is a
! 526: directory or a device special file.) Also suppresses the warn-
! 527: ing message when a binary file is opened. By default, [4mless[24m will
! 528: refuse to open non-regular files. Note that some operating sys-
! 529: tems will not allow directories to be read, even if -f is set.
! 530:
! 531: -F or --quit-if-one-screen
! 532: Causes [4mless[24m to automatically exit if the entire file can be dis-
! 533: played on the first screen.
! 534:
! 535: -g or --hilite-search
! 536: Normally, [4mless[24m will highlight ALL strings which match the last
! 537: search command. The -g option changes this behavior to high-
! 538: light only the particular string which was found by the last
! 539: search command. This can cause [4mless[24m to run somewhat faster than
! 540: the default.
! 541:
! 542: -G or --HILITE-SEARCH
! 543: The -G option suppresses all highlighting of strings found by
! 544: search commands.
! 545:
! 546: -h[4mn[24m or --max-back-scroll=[4mn[0m
! 547: Specifies a maximum number of lines to scroll backward. If it
! 548: is necessary to scroll backward more than [4mn[24m lines, the screen is
! 549: repainted in a forward direction instead. (If the terminal does
! 550: not have the ability to scroll backward, -h0 is implied.)
! 551:
! 552: -i or --ignore-case
! 553: Causes searches to ignore case; that is, uppercase and lowercase
! 554: are considered identical. This option is ignored if any upper-
! 555: case letters appear in the search pattern; in other words, if a
! 556: pattern contains uppercase letters, then that search does not
! 557: ignore case.
! 558:
! 559: -I or --IGNORE-CASE
! 560: Like -i, but searches ignore case even if the pattern contains
! 561: uppercase letters.
! 562:
! 563: -j[4mn[24m or --jump-target=[4mn[0m
! 564: Specifies a line on the screen where the "target" line is to be
! 565: positioned. The target line is the line specified by any com-
! 566: mand to search for a pattern, jump to a line number, jump to a
! 567: file percentage or jump to a tag. The screen line may be speci-
! 568: fied by a number: the top line on the screen is 1, the next is
! 569: 2, and so on. The number may be negative to specify a line rel-
! 570: ative to the bottom of the screen: the bottom line on the screen
! 571: is -1, the second to the bottom is -2, and so on. Alternately,
! 572: the screen line may be specified as a fraction of the height of
! 573: the screen, starting with a decimal point: .5 is in the middle
! 574: of the screen, .3 is three tenths down from the first line, and
! 575: so on. If the line is specified as a fraction, the actual line
! 576: number is recalculated if the terminal window is resized, so
! 577: that the target line remains at the specified fraction of the
! 578: screen height. If any form of the -j option is used, forward
! 579: searches begin at the line immediately after the target line,
! 580: and backward searches begin at the target line, unless changed
! 581: by -a or -A. For example, if "-j4" is used, the target line is
! 582: the fourth line on the screen, so forward searches begin at the
! 583: fifth line on the screen.
! 584:
! 585: -J or --status-column
! 586: Displays a status column at the left edge of the screen. The
! 587: status column shows the lines that matched the current search.
! 588: The status column is also used if the -w or -W option is in
! 589: effect.
! 590:
! 591: -k[4mfilename[24m or --lesskey-file=[4mfilename[0m
! 592: Causes [4mless[24m to open and interpret the named file as a [4mlesskey[0m
! 593: (1) file. Multiple -k options may be specified. If the LESSKEY
! 594: or LESSKEY_SYSTEM environment variable is set, or if a lesskey
! 595: file is found in a standard place (see KEY BINDINGS), it is also
! 596: used as a [4mlesskey[24m file.
! 597:
! 598: -K or --quit-on-intr
! 599: Causes [4mless[24m to exit immediately (with status 2) when an inter-
! 600: rupt character (usually ^C) is typed. Normally, an interrupt
! 601: character causes [4mless[24m to stop whatever it is doing and return to
! 602: its command prompt. Note that use of this option makes it
! 603: impossible to return to the command prompt from the "F" command.
! 604:
! 605: -L or --no-lessopen
! 606: Ignore the LESSOPEN environment variable (see the INPUT PRE-
! 607: PROCESSOR section below). This option can be set from within
! 608: [4mless[24m, but it will apply only to files opened subsequently, not
! 609: to the file which is currently open.
! 610:
! 611: -m or --long-prompt
! 612: Causes [4mless[24m to prompt verbosely (like [4mmore[24m), with the percent
! 613: into the file. By default, [4mless[24m prompts with a colon.
! 614:
! 615: -M or --LONG-PROMPT
! 616: Causes [4mless[24m to prompt even more verbosely than [4mmore.[0m
! 617:
! 618: -n or --line-numbers
! 619: Suppresses line numbers. The default (to use line numbers) may
! 620: cause [4mless[24m to run more slowly in some cases, especially with a
! 621: very large input file. Suppressing line numbers with the -n
! 622: option will avoid this problem. Using line numbers means: the
! 623: line number will be displayed in the verbose prompt and in the =
! 624: command, and the v command will pass the current line number to
! 625: the editor (see also the discussion of LESSEDIT in PROMPTS
! 626: below).
! 627:
! 628: -N or --LINE-NUMBERS
! 629: Causes a line number to be displayed at the beginning of each
! 630: line in the display.
! 631:
! 632: -o[4mfilename[24m or --log-file=[4mfilename[0m
! 633: Causes [4mless[24m to copy its input to the named file as it is being
! 634: viewed. This applies only when the input file is a pipe, not an
! 635: ordinary file. If the file already exists, [4mless[24m will ask for
! 636: confirmation before overwriting it.
! 637:
! 638: -O[4mfilename[24m or --LOG-FILE=[4mfilename[0m
! 639: The -O option is like -o, but it will overwrite an existing file
! 640: without asking for confirmation.
! 641:
! 642: If no log file has been specified, the -o and -O options can be
! 643: used from within [4mless[24m to specify a log file. Without a file
! 644: name, they will simply report the name of the log file. The "s"
! 645: command is equivalent to specifying -o from within [4mless.[0m
! 646:
! 647: -p[4mpattern[24m or --pattern=[4mpattern[0m
! 648: The -p option on the command line is equivalent to specifying
! 649: +/[4mpattern[24m; that is, it tells [4mless[24m to start at the first occur-
! 650: rence of [4mpattern[24m in the file.
! 651:
! 652: -P[4mprompt[24m or --prompt=[4mprompt[0m
! 653: Provides a way to tailor the three prompt styles to your own
! 654: preference. This option would normally be put in the LESS envi-
! 655: ronment variable, rather than being typed in with each [4mless[24m com-
! 656: mand. Such an option must either be the last option in the LESS
! 657: variable, or be terminated by a dollar sign. -Ps followed by a
! 658: string changes the default (short) prompt to that string. -Pm
! 659: changes the medium (-m) prompt. -PM changes the long (-M)
! 660: prompt. -Ph changes the prompt for the help screen. -P=
! 661: changes the message printed by the = command. -Pw changes the
! 662: message printed while waiting for data (in the F command). All
! 663: prompt strings consist of a sequence of letters and special
! 664: escape sequences. See the section on PROMPTS for more details.
! 665:
! 666: -q or --quiet or --silent
! 667: Causes moderately "quiet" operation: the terminal bell is not
! 668: rung if an attempt is made to scroll past the end of the file or
! 669: before the beginning of the file. If the terminal has a "visual
! 670: bell", it is used instead. The bell will be rung on certain
! 671: other errors, such as typing an invalid character. The default
! 672: is to ring the terminal bell in all such cases.
! 673:
! 674: -Q or --QUIET or --SILENT
! 675: Causes totally "quiet" operation: the terminal bell is never
! 676: rung.
! 677:
! 678: -r or --raw-control-chars
! 679: Causes "raw" control characters to be displayed. The default is
! 680: to display control characters using the caret notation; for
! 681: example, a control-A (octal 001) is displayed as "^A". Warning:
! 682: when the -r option is used, [4mless[24m cannot keep track of the actual
! 683: appearance of the screen (since this depends on how the screen
! 684: responds to each type of control character). Thus, various dis-
! 685: play problems may result, such as long lines being split in the
! 686: wrong place.
! 687:
! 688: -R or --RAW-CONTROL-CHARS
! 689: Like -r, but only ANSI "color" escape sequences are output in
! 690: "raw" form. Unlike -r, the screen appearance is maintained cor-
! 691: rectly in most cases. ANSI "color" escape sequences are
! 692: sequences of the form:
! 693:
! 694: ESC [ ... m
! 695:
! 696: where the "..." is zero or more color specification characters
! 697: For the purpose of keeping track of screen appearance, ANSI
! 698: color escape sequences are assumed to not move the cursor. You
! 699: can make [4mless[24m think that characters other than "m" can end ANSI
! 700: color escape sequences by setting the environment variable
! 701: LESSANSIENDCHARS to the list of characters which can end a color
! 702: escape sequence. And you can make [4mless[24m think that characters
! 703: other than the standard ones may appear between the ESC and the
! 704: m by setting the environment variable LESSANSIMIDCHARS to the
! 705: list of characters which can appear.
! 706:
! 707: -s or --squeeze-blank-lines
! 708: Causes consecutive blank lines to be squeezed into a single
! 709: blank line. This is useful when viewing [4mnroff[24m output.
! 710:
! 711: -S or --chop-long-lines
! 712: Causes lines longer than the screen width to be chopped rather
! 713: than folded. That is, the portion of a long line that does not
! 714: fit in the screen width is not shown. The default is to fold
! 715: long lines; that is, display the remainder on the next line.
! 716:
! 717: -t[4mtag[24m or --tag=[4mtag[0m
! 718: The -t option, followed immediately by a TAG, will edit the file
! 719: containing that tag. For this to work, tag information must be
! 720: available; for example, there may be a file in the current
! 721: directory called "tags", which was previously built by [4mctags[24m (1)
! 722: or an equivalent command. If the environment variable LESSGLOB-
! 723: ALTAGS is set, it is taken to be the name of a command compati-
! 724: ble with [4mglobal[24m (1), and that command is executed to find the
! 725: tag. (See http://www.gnu.org/software/global/global.html). The
! 726: -t option may also be specified from within [4mless[24m (using the -
! 727: command) as a way of examining a new file. The command ":t" is
! 728: equivalent to specifying -t from within [4mless.[0m
! 729:
! 730: -T[4mtagsfile[24m or --tag-file=[4mtagsfile[0m
! 731: Specifies a tags file to be used instead of "tags".
! 732:
! 733: -u or --underline-special
! 734: Causes backspaces and carriage returns to be treated as print-
! 735: able characters; that is, they are sent to the terminal when
! 736: they appear in the input.
! 737:
! 738: -U or --UNDERLINE-SPECIAL
! 739: Causes backspaces, tabs and carriage returns to be treated as
! 740: control characters; that is, they are handled as specified by
! 741: the -r option.
! 742:
! 743: By default, if neither -u nor -U is given, backspaces which
! 744: appear adjacent to an underscore character are treated spe-
! 745: cially: the underlined text is displayed using the terminal's
! 746: hardware underlining capability. Also, backspaces which appear
! 747: between two identical characters are treated specially: the
! 748: overstruck text is printed using the terminal's hardware bold-
! 749: face capability. Other backspaces are deleted, along with the
! 750: preceding character. Carriage returns immediately followed by a
! 751: newline are deleted. other carriage returns are handled as
! 752: specified by the -r option. Text which is overstruck or under-
! 753: lined can be searched for if neither -u nor -U is in effect.
! 754:
! 755: -V or --version
! 756: Displays the version number of [4mless.[0m
! 757:
! 758: -w or --hilite-unread
! 759: Temporarily highlights the first "new" line after a forward
! 760: movement of a full page. The first "new" line is the line imme-
! 761: diately following the line previously at the bottom of the
! 762: screen. Also highlights the target line after a g or p command.
! 763: The highlight is removed at the next command which causes move-
! 764: ment. The entire line is highlighted, unless the -J option is
! 765: in effect, in which case only the status column is highlighted.
! 766:
! 767: -W or --HILITE-UNREAD
! 768: Like -w, but temporarily highlights the first new line after any
! 769: forward movement command larger than one line.
! 770:
! 771: -x[4mn[24m,... or --tabs=[4mn[24m,...
! 772: Sets tab stops. If only one [4mn[24m is specified, tab stops are set
! 773: at multiples of [4mn[24m. If multiple values separated by commas are
! 774: specified, tab stops are set at those positions, and then con-
! 775: tinue with the same spacing as the last two. For example,
! 776: [4m-x9,17[24m will set tabs at positions 9, 17, 25, 33, etc. The
! 777: default for [4mn[24m is 8.
! 778:
! 779: -X or --no-init
! 780: Disables sending the termcap initialization and deinitialization
! 781: strings to the terminal. This is sometimes desirable if the
! 782: deinitialization string does something unnecessary, like clear-
! 783: ing the screen.
! 784:
! 785: -y[4mn[24m or --max-forw-scroll=[4mn[0m
! 786: Specifies a maximum number of lines to scroll forward. If it is
! 787: necessary to scroll forward more than [4mn[24m lines, the screen is
! 788: repainted instead. The -c or -C option may be used to repaint
! 789: from the top of the screen if desired. By default, any forward
! 790: movement causes scrolling.
! 791:
! 792: -[z][4mn[24m or --window=[4mn[0m
! 793: Changes the default scrolling window size to [4mn[24m lines. The
! 794: default is one screenful. The z and w commands can also be used
! 795: to change the window size. The "z" may be omitted for compati-
! 796: bility with some versions of [4mmore.[24m If the number [4mn[24m is negative,
! 797: it indicates [4mn[24m lines less than the current screen size. For
! 798: example, if the screen is 24 lines, [4m-z-4[24m sets the scrolling win-
! 799: dow to 20 lines. If the screen is resized to 40 lines, the
! 800: scrolling window automatically changes to 36 lines.
! 801:
! 802: -[4m"cc[24m or --quotes=[4mcc[0m
! 803: Changes the filename quoting character. This may be necessary
! 804: if you are trying to name a file which contains both spaces and
! 805: quote characters. Followed by a single character, this changes
! 806: the quote character to that character. Filenames containing a
! 807: space should then be surrounded by that character rather than by
! 808: double quotes. Followed by two characters, changes the open
! 809: quote to the first character, and the close quote to the second
! 810: character. Filenames containing a space should then be preceded
! 811: by the open quote character and followed by the close quote
! 812: character. Note that even after the quote characters are
! 813: changed, this option remains -" (a dash followed by a double
! 814: quote).
! 815:
! 816: -~ or --tilde
! 817: Normally lines after end of file are displayed as a single tilde
! 818: (~). This option causes lines after end of file to be displayed
! 819: as blank lines.
! 820:
! 821: -# or --shift
! 822: Specifies the default number of positions to scroll horizontally
! 823: in the RIGHTARROW and LEFTARROW commands. If the number speci-
! 824: fied is zero, it sets the default number of positions to one
! 825: half of the screen width. Alternately, the number may be speci-
! 826: fied as a fraction of the width of the screen, starting with a
! 827: decimal point: .5 is half of the screen width, .3 is three
! 828: tenths of the screen width, and so on. If the number is speci-
! 829: fied as a fraction, the actual number of scroll positions is
! 830: recalculated if the terminal window is resized, so that the
! 831: actual scroll remains at the specified fraction of the screen
! 832: width.
! 833:
! 834: --no-keypad
! 835: Disables sending the keypad initialization and deinitialization
! 836: strings to the terminal. This is sometimes useful if the keypad
! 837: strings make the numeric keypad behave in an undesirable manner.
! 838:
! 839: --follow-name
! 840: Normally, if the input file is renamed while an F command is
! 841: executing, [4mless[24m will continue to display the contents of the
! 842: original file despite its name change. If --follow-name is
! 843: specified, during an F command [4mless[24m will periodically attempt to
! 844: reopen the file by name. If the reopen succeeds and the file is
! 845: a different file from the original (which means that a new file
! 846: has been created with the same name as the original (now
! 847: renamed) file), [4mless[24m will display the contents of that new file.
! 848:
! 849: -- A command line argument of "--" marks the end of option argu-
! 850: ments. Any arguments following this are interpreted as file-
! 851: names. This can be useful when viewing a file whose name begins
! 852: with a "-" or "+".
! 853:
! 854: + If a command line option begins with [1m+[22m, the remainder of that
! 855: option is taken to be an initial command to [4mless.[24m For example,
! 856: +G tells [4mless[24m to start at the end of the file rather than the
! 857: beginning, and +/xyz tells it to start at the first occurrence
! 858: of "xyz" in the file. As a special case, +<number> acts like
! 859: +<number>g; that is, it starts the display at the specified line
! 860: number (however, see the caveat under the "g" command above).
! 861: If the option starts with ++, the initial command applies to
! 862: every file being viewed, not just the first one. The + command
! 863: described previously may also be used to set (or change) an ini-
! 864: tial command for every file.
! 865:
! 866:
! 867: [1mLINE EDITING[0m
! 868: When entering command line at the bottom of the screen (for example, a
! 869: filename for the :e command, or the pattern for a search command), cer-
! 870: tain keys can be used to manipulate the command line. Most commands
! 871: have an alternate form in [ brackets ] which can be used if a key does
! 872: not exist on a particular keyboard. (Note that the forms beginning
! 873: with ESC do not work in some MS-DOS and Windows systems because ESC is
! 874: the line erase character.) Any of these special keys may be entered
! 875: literally by preceding it with the "literal" character, either ^V or
! 876: ^A. A backslash itself may also be entered literally by entering two
! 877: backslashes.
! 878:
! 879: LEFTARROW [ ESC-h ]
! 880: Move the cursor one space to the left.
! 881:
! 882: RIGHTARROW [ ESC-l ]
! 883: Move the cursor one space to the right.
! 884:
! 885: ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
! 886: (That is, CONTROL and LEFTARROW simultaneously.) Move the cur-
! 887: sor one word to the left.
! 888:
! 889: ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
! 890: (That is, CONTROL and RIGHTARROW simultaneously.) Move the cur-
! 891: sor one word to the right.
! 892:
! 893: HOME [ ESC-0 ]
! 894: Move the cursor to the beginning of the line.
! 895:
! 896: END [ ESC-$ ]
! 897: Move the cursor to the end of the line.
! 898:
! 899: BACKSPACE
! 900: Delete the character to the left of the cursor, or cancel the
! 901: command if the command line is empty.
! 902:
! 903: DELETE or [ ESC-x ]
! 904: Delete the character under the cursor.
! 905:
! 906: ^BACKSPACE [ ESC-BACKSPACE ]
! 907: (That is, CONTROL and BACKSPACE simultaneously.) Delete the
! 908: word to the left of the cursor.
! 909:
! 910: ^DELETE [ ESC-X or ESC-DELETE ]
! 911: (That is, CONTROL and DELETE simultaneously.) Delete the word
! 912: under the cursor.
! 913:
! 914: UPARROW [ ESC-k ]
! 915: Retrieve the previous command line.
! 916:
! 917: DOWNARROW [ ESC-j ]
! 918: Retrieve the next command line.
! 919:
! 920: TAB Complete the partial filename to the left of the cursor. If it
! 921: matches more than one filename, the first match is entered into
! 922: the command line. Repeated TABs will cycle thru the other
! 923: matching filenames. If the completed filename is a directory, a
! 924: "/" is appended to the filename. (On MS-DOS systems, a "\" is
! 925: appended.) The environment variable LESSSEPARATOR can be used
! 926: to specify a different character to append to a directory name.
! 927:
! 928: BACKTAB [ ESC-TAB ]
! 929: Like, TAB, but cycles in the reverse direction thru the matching
! 930: filenames.
! 931:
! 932: ^L Complete the partial filename to the left of the cursor. If it
! 933: matches more than one filename, all matches are entered into the
! 934: command line (if they fit).
! 935:
! 936: ^U (Unix and OS/2) or ESC (MS-DOS)
! 937: Delete the entire command line, or cancel the command if the
! 938: command line is empty. If you have changed your line-kill char-
! 939: acter in Unix to something other than ^U, that character is used
! 940: instead of ^U.
! 941:
! 942: ^G Delete the entire command line and return to the main prompt.
! 943:
! 944:
! 945: [1mKEY BINDINGS[0m
! 946: You may define your own [4mless[24m commands by using the program [4mlesskey[24m (1)
! 947: to create a lesskey file. This file specifies a set of command keys
! 948: and an action associated with each key. You may also use [4mlesskey[24m to
! 949: change the line-editing keys (see LINE EDITING), and to set environment
! 950: variables. If the environment variable LESSKEY is set, [4mless[24m uses that
! 951: as the name of the lesskey file. Otherwise, [4mless[24m looks in a standard
! 952: place for the lesskey file: On Unix systems, [4mless[24m looks for a lesskey
! 953: file called "$HOME/.less". On MS-DOS and Windows systems, [4mless[24m looks
! 954: for a lesskey file called "$HOME/_less", and if it is not found there,
! 955: then looks for a lesskey file called "_less" in any directory specified
! 956: in the PATH environment variable. On OS/2 systems, [4mless[24m looks for a
! 957: lesskey file called "$HOME/less.ini", and if it is not found, then
! 958: looks for a lesskey file called "less.ini" in any directory specified
! 959: in the INIT environment variable, and if it not found there, then looks
! 960: for a lesskey file called "less.ini" in any directory specified in the
! 961: PATH environment variable. See the [4mlesskey[24m manual page for more
! 962: details.
! 963:
! 964: A system-wide lesskey file may also be set up to provide key bindings.
! 965: If a key is defined in both a local lesskey file and in the system-wide
! 966: file, key bindings in the local file take precedence over those in the
! 967: system-wide file. If the environment variable LESSKEY_SYSTEM is set,
! 968: [4mless[24m uses that as the name of the system-wide lesskey file. Otherwise,
! 969: [4mless[24m looks in a standard place for the system-wide lesskey file: On
! 970: Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
! 971: (However, if [4mless[24m was built with a different sysconf directory than
! 972: /usr/local/etc, that directory is where the sysless file is found.) On
! 973: MS-DOS and Windows systems, the system-wide lesskey file is c:\_sys-
! 974: less. On OS/2 systems, the system-wide lesskey file is c:\sysless.ini.
! 975:
! 976:
! 977: [1mINPUT PREPROCESSOR[0m
! 978: You may define an "input preprocessor" for [4mless.[24m Before [4mless[24m opens a
! 979: file, it first gives your input preprocessor a chance to modify the way
! 980: the contents of the file are displayed. An input preprocessor is sim-
! 981: ply an executable program (or shell script), which writes the contents
! 982: of the file to a different file, called the replacement file. The con-
! 983: tents of the replacement file are then displayed in place of the con-
! 984: tents of the original file. However, it will appear to the user as if
! 985: the original file is opened; that is, [4mless[24m will display the original
! 986: filename as the name of the current file.
! 987:
! 988: An input preprocessor receives one command line argument, the original
! 989: filename, as entered by the user. It should create the replacement
! 990: file, and when finished, print the name of the replacement file to its
! 991: standard output. If the input preprocessor does not output a replace-
! 992: ment filename, [4mless[24m uses the original file, as normal. The input pre-
! 993: processor is not called when viewing standard input. To set up an
! 994: input preprocessor, set the LESSOPEN environment variable to a command
! 995: line which will invoke your input preprocessor. This command line
! 996: should include one occurrence of the string "%s", which will be
! 997: replaced by the filename when the input preprocessor command is
! 998: invoked.
! 999:
! 1000: When [4mless[24m closes a file opened in such a way, it will call another pro-
! 1001: gram, called the input postprocessor, which may perform any desired
! 1002: clean-up action (such as deleting the replacement file created by
! 1003: LESSOPEN). This program receives two command line arguments, the orig-
! 1004: inal filename as entered by the user, and the name of the replacement
! 1005: file. To set up an input postprocessor, set the LESSCLOSE environment
! 1006: variable to a command line which will invoke your input postprocessor.
! 1007: It may include two occurrences of the string "%s"; the first is
! 1008: replaced with the original name of the file and the second with the
! 1009: name of the replacement file, which was output by LESSOPEN.
! 1010:
! 1011: For example, on many Unix systems, these two scripts will allow you to
! 1012: keep files in compressed format, but still let [4mless[24m view them directly:
! 1013:
! 1014: lessopen.sh:
! 1015: #! /bin/sh
! 1016: case "$1" in
! 1017: *.Z) uncompress -
! 1018: if [ -s /tmp/less.$$ ]; then
! 1019: echo /tmp/less.$$
! 1020: else
! 1021: rm -f /tmp/less.$$
! 1022: fi
! 1023: ;;
! 1024: esac
! 1025:
! 1026: lessclose.sh:
! 1027: #! /bin/sh
! 1028: rm $2
! 1029:
! 1030: To use these scripts, put them both where they can be executed and set
! 1031: LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
! 1032: complex LESSOPEN and LESSCLOSE scripts may be written to accept other
! 1033: types of compressed files, and so on.
! 1034:
! 1035: It is also possible to set up an input preprocessor to pipe the file
! 1036: data directly to [4mless,[24m rather than putting the data into a replacement
! 1037: file. This avoids the need to decompress the entire file before start-
! 1038: ing to view it. An input preprocessor that works this way is called an
! 1039: input pipe. An input pipe, instead of writing the name of a replace-
! 1040: ment file on its standard output, writes the entire contents of the
! 1041: replacement file on its standard output. If the input pipe does not
! 1042: write any characters on its standard output, then there is no replace-
! 1043: ment file and [4mless[24m uses the original file, as normal. To use an input
! 1044: pipe, make the first character in the LESSOPEN environment variable a
! 1045: vertical bar (|) to signify that the input preprocessor is an input
! 1046: pipe.
! 1047:
! 1048: For example, on many Unix systems, this script will work like the pre-
! 1049: vious example scripts:
! 1050:
! 1051: lesspipe.sh:
! 1052: #! /bin/sh
! 1053: case "$1" in
! 1054: *.Z) uncompress -c $1 2>/dev/null
! 1055: ;;
! 1056: esac
! 1057:
! 1058: To use this script, put it where it can be executed and set
! 1059: LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE
! 1060: postprocessor can be used, but it is usually not necessary since there
! 1061: is no replacement file to clean up. In this case, the replacement file
! 1062: name passed to the LESSCLOSE postprocessor is "-".
! 1063:
! 1064: For compatibility with previous versions of [4mless,[24m the input preproces-
! 1065: sor or pipe is not used if [4mless[24m is viewing standard input. However, if
! 1066: the first character of LESSOPEN is a dash (-), the input preprocessor
! 1067: is used on standard input as well as other files. In this case, the
! 1068: dash is not considered to be part of the preprocessor command. If
! 1069: standard input is being viewed, the input preprocessor is passed a file
! 1070: name consisting of a single dash. Similarly, if the first two charac-
! 1071: ters of LESSOPEN are vertical bar and dash (|-), the input pipe is used
! 1072: on standard input as well as other files. Again, in this case the dash
! 1073: is not considered to be part of the input pipe command.
! 1074:
! 1075:
! 1076: [1mNATIONAL CHARACTER SETS[0m
! 1077: There are three types of characters in the input file:
! 1078:
! 1079: normal characters
! 1080: can be displayed directly to the screen.
! 1081:
! 1082: control characters
! 1083: should not be displayed directly, but are expected to be found
! 1084: in ordinary text files (such as backspace and tab).
! 1085:
! 1086: binary characters
! 1087: should not be displayed directly and are not expected to be
! 1088: found in text files.
! 1089:
! 1090: A "character set" is simply a description of which characters are to be
! 1091: considered normal, control, and binary. The LESSCHARSET environment
! 1092: variable may be used to select a character set. Possible values for
! 1093: LESSCHARSET are:
! 1094:
! 1095: ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
! 1096: with values between 32 and 126 are normal, and all others are
! 1097: binary.
! 1098:
! 1099: iso8859
! 1100: Selects an ISO 8859 character set. This is the same as ASCII,
! 1101: except characters between 160 and 255 are treated as normal
! 1102: characters.
! 1103:
! 1104: latin1 Same as iso8859.
! 1105:
! 1106: latin9 Same as iso8859.
! 1107:
! 1108: dos Selects a character set appropriate for MS-DOS.
! 1109:
! 1110: ebcdic Selects an EBCDIC character set.
! 1111:
! 1112: IBM-1047
! 1113: Selects an EBCDIC character set used by OS/390 Unix Services.
! 1114: This is the EBCDIC analogue of latin1. You get similar results
! 1115: by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
! 1116: environment.
! 1117:
! 1118: koi8-r Selects a Russian character set.
! 1119:
! 1120: next Selects a character set appropriate for NeXT computers.
! 1121:
! 1122: utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
! 1123: UTF-8 is special in that it supports multi-byte characters in
! 1124: the input file. It is the only character set that supports
! 1125: multi-byte characters.
! 1126:
! 1127: windows
! 1128: Selects a character set appropriate for Microsoft Windows (cp
! 1129: 1251).
! 1130:
! 1131: In rare cases, it may be desired to tailor [4mless[24m to use a character set
! 1132: other than the ones definable by LESSCHARSET. In this case, the envi-
! 1133: ronment variable LESSCHARDEF can be used to define a character set. It
! 1134: should be set to a string where each character in the string represents
! 1135: one character in the character set. The character "." is used for a
! 1136: normal character, "c" for control, and "b" for binary. A decimal num-
! 1137: ber may be used for repetition. For example, "bccc4b." would mean
! 1138: character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are
! 1139: binary, and 8 is normal. All characters after the last are taken to be
! 1140: the same as the last, so characters 9 through 255 would be normal.
! 1141: (This is an example, and does not necessarily represent any real char-
! 1142: acter set.)
! 1143:
! 1144: This table shows the value of LESSCHARDEF which is equivalent to each
! 1145: of the possible values for LESSCHARSET:
! 1146:
! 1147: ascii 8bcccbcc18b95.b
! 1148: dos 8bcccbcc12bc5b95.b.
! 1149: ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
! 1150: 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
! 1151: IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
! 1152: 191.b
! 1153: iso8859 8bcccbcc18b95.33b.
! 1154: koi8-r 8bcccbcc18b95.b128.
! 1155: latin1 8bcccbcc18b95.33b.
! 1156: next 8bcccbcc18b95.bb125.bb
! 1157:
! 1158: If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
! 1159: "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
! 1160: LANG environment variables, then the default character set is utf-8.
! 1161:
! 1162: If that string is not found, but your system supports the [4msetlocale[0m
! 1163: interface, [4mless[24m will use setlocale to determine the character set.
! 1164: setlocale is controlled by setting the LANG or LC_CTYPE environment
! 1165: variables.
! 1166:
! 1167: Finally, if the [4msetlocale[24m interface is also not available, the default
! 1168: character set is latin1.
! 1169:
! 1170: Control and binary characters are displayed in standout (reverse
! 1171: video). Each such character is displayed in caret notation if possible
! 1172: (e.g. ^A for control-A). Caret notation is used only if inverting the
! 1173: 0100 bit results in a normal printable character. Otherwise, the char-
! 1174: acter is displayed as a hex number in angle brackets. This format can
! 1175: be changed by setting the LESSBINFMT environment variable. LESSBINFMT
! 1176: may begin with a "*" and one character to select the display attribute:
! 1177: "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
! 1178: and "*n" is normal. If LESSBINFMT does not begin with a "*", normal
! 1179: attribute is assumed. The remainder of LESSBINFMT is a string which
! 1180: may include one printf-style escape sequence (a % followed by x, X, o,
! 1181: d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters
! 1182: are displayed in underlined hexadecimal surrounded by brackets. The
! 1183: default if no LESSBINFMT is specified is "*s<%02X>". Warning: the
! 1184: result of expanding the character via LESSBINFMT must be less than 31
! 1185: characters.
! 1186:
! 1187: When the character set is utf-8, the LESSUTFBINFMT environment variable
! 1188: acts similarly to LESSBINFMT but it applies to Unicode code points that
! 1189: were successfully decoded but are unsuitable for display (e.g., unas-
! 1190: signed code points). Its default value is "<U+%04lX>". Note that
! 1191: LESSUTFBINFMT and LESSBINFMT share their display attribute setting
! 1192: ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
! 1193: LESSBINFMT so its setting, if any, will have priority. Problematic
! 1194: octets in a UTF-8 file (octets of a truncated sequence, octets of a
! 1195: complete but non-shortest form sequence, illegal octets, and stray
! 1196: trailing octets) are displayed individually using LESSBINFMT so as to
! 1197: facilitate diagnostic of how the UTF-8 file is ill-formed.
! 1198:
! 1199:
! 1200: [1mPROMPTS[0m
! 1201: The -P option allows you to tailor the prompt to your preference. The
! 1202: string given to the -P option replaces the specified prompt string.
! 1203: Certain characters in the string are interpreted specially. The prompt
! 1204: mechanism is rather complicated to provide flexibility, but the ordi-
! 1205: nary user need not understand the details of constructing personalized
! 1206: prompt strings.
! 1207:
! 1208: A percent sign followed by a single character is expanded according to
! 1209: what the following character is:
! 1210:
! 1211: %b[4mX[24m Replaced by the byte offset into the current input file. The b
! 1212: is followed by a single character (shown as [4mX[24m above) which spec-
! 1213: ifies the line whose byte offset is to be used. If the charac-
! 1214: ter is a "t", the byte offset of the top line in the display is
! 1215: used, an "m" means use the middle line, a "b" means use the bot-
! 1216: tom line, a "B" means use the line just after the bottom line,
! 1217: and a "j" means use the "target" line, as specified by the -j
! 1218: option.
! 1219:
! 1220: %B Replaced by the size of the current input file.
! 1221:
! 1222: %c Replaced by the column number of the text appearing in the first
! 1223: column of the screen.
! 1224:
! 1225: %d[4mX[24m Replaced by the page number of a line in the input file. The
! 1226: line to be used is determined by the [4mX[24m, as with the %b option.
! 1227:
! 1228: %D Replaced by the number of pages in the input file, or equiva-
! 1229: lently, the page number of the last line in the input file.
! 1230:
! 1231: %E Replaced by the name of the editor (from the VISUAL environment
! 1232: variable, or the EDITOR environment variable if VISUAL is not
! 1233: defined). See the discussion of the LESSEDIT feature below.
! 1234:
! 1235: %f Replaced by the name of the current input file.
! 1236:
! 1237: %F Replaced by the last component of the name of the current input
! 1238: file.
! 1239:
! 1240: %i Replaced by the index of the current file in the list of input
! 1241: files.
! 1242:
! 1243: %l[4mX[24m Replaced by the line number of a line in the input file. The
! 1244: line to be used is determined by the [4mX[24m, as with the %b option.
! 1245:
! 1246: %L Replaced by the line number of the last line in the input file.
! 1247:
! 1248: %m Replaced by the total number of input files.
! 1249:
! 1250: %p[4mX[24m Replaced by the percent into the current input file, based on
! 1251: byte offsets. The line used is determined by the [4mX[24m as with the
! 1252: %b option.
! 1253:
! 1254: %P[4mX[24m Replaced by the percent into the current input file, based on
! 1255: line numbers. The line used is determined by the [4mX[24m as with the
! 1256: %b option.
! 1257:
! 1258: %s Same as %B.
! 1259:
! 1260: %t Causes any trailing spaces to be removed. Usually used at the
! 1261: end of the string, but may appear anywhere.
! 1262:
! 1263: %x Replaced by the name of the next input file in the list.
! 1264:
! 1265: If any item is unknown (for example, the file size if input is a pipe),
! 1266: a question mark is printed instead.
! 1267:
! 1268: The format of the prompt string can be changed depending on certain
! 1269: conditions. A question mark followed by a single character acts like
! 1270: an "IF": depending on the following character, a condition is evalu-
! 1271: ated. If the condition is true, any characters following the question
! 1272: mark and condition character, up to a period, are included in the
! 1273: prompt. If the condition is false, such characters are not included.
! 1274: A colon appearing between the question mark and the period can be used
! 1275: to establish an "ELSE": any characters between the colon and the period
! 1276: are included in the string if and only if the IF condition is false.
! 1277: Condition characters (which follow a question mark) may be:
! 1278:
! 1279: ?a True if any characters have been included in the prompt so far.
! 1280:
! 1281: ?b[4mX[24m True if the byte offset of the specified line is known.
! 1282:
! 1283: ?B True if the size of current input file is known.
! 1284:
! 1285: ?c True if the text is horizontally shifted (%c is not zero).
! 1286:
! 1287: ?d[4mX[24m True if the page number of the specified line is known.
! 1288:
! 1289: ?e True if at end-of-file.
! 1290:
! 1291: ?f True if there is an input filename (that is, if input is not a
! 1292: pipe).
! 1293:
! 1294: ?l[4mX[24m True if the line number of the specified line is known.
! 1295:
! 1296: ?L True if the line number of the last line in the file is known.
! 1297:
! 1298: ?m True if there is more than one input file.
! 1299:
! 1300: ?n True if this is the first prompt in a new input file.
! 1301:
! 1302: ?p[4mX[24m True if the percent into the current input file, based on byte
! 1303: offsets, of the specified line is known.
! 1304:
! 1305: ?P[4mX[24m True if the percent into the current input file, based on line
! 1306: numbers, of the specified line is known.
! 1307:
! 1308: ?s Same as "?B".
! 1309:
! 1310: ?x True if there is a next input file (that is, if the current
! 1311: input file is not the last one).
! 1312:
! 1313: Any characters other than the special ones (question mark, colon,
! 1314: period, percent, and backslash) become literally part of the prompt.
! 1315: Any of the special characters may be included in the prompt literally
! 1316: by preceding it with a backslash.
! 1317:
! 1318: Some examples:
! 1319:
! 1320: ?f%f:Standard input.
! 1321:
! 1322: This prompt prints the filename, if known; otherwise the string "Stan-
! 1323: dard input".
! 1324:
! 1325: ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
! 1326:
! 1327: This prompt would print the filename, if known. The filename is fol-
! 1328: lowed by the line number, if known, otherwise the percent if known,
! 1329: otherwise the byte offset if known. Otherwise, a dash is printed.
! 1330: Notice how each question mark has a matching period, and how the %
! 1331: after the %pt is included literally by escaping it with a backslash.
! 1332:
! 1333: ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x..%t
! 1334:
! 1335: This prints the filename if this is the first prompt in a file, fol-
! 1336: lowed by the "file N of N" message if there is more than one input
! 1337: file. Then, if we are at end-of-file, the string "(END)" is printed
! 1338: followed by the name of the next file, if there is one. Finally, any
! 1339: trailing spaces are truncated. This is the default prompt. For refer-
! 1340: ence, here are the defaults for the other two prompts (-m and -M
! 1341: respectively). Each is broken into two lines here for readability
! 1342: only.
! 1343:
! 1344: ?n?f%f .?m(file %i of %m) ..?e(END) ?x- Next\: %x.:
! 1345: ?pB%pB\%:byte %bB?s/%s...%t
! 1346:
! 1347: ?f%f .?n?m(file %i of %m) ..?ltlines %lt-%lb?L/%L. :
! 1348: byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
! 1349:
! 1350: And here is the default message produced by the = command:
! 1351:
! 1352: ?f%f .?m(file %i of %m) .?ltlines %lt-%lb?L/%L. .
! 1353: byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
! 1354:
! 1355: The prompt expansion features are also used for another purpose: if an
! 1356: environment variable LESSEDIT is defined, it is used as the command to
! 1357: be executed when the v command is invoked. The LESSEDIT string is
! 1358: expanded in the same way as the prompt strings. The default value for
! 1359: LESSEDIT is:
! 1360:
! 1361: %E ?lm+%lm. %f
! 1362:
! 1363: Note that this expands to the editor name, followed by a + and the line
! 1364: number, followed by the file name. If your editor does not accept the
! 1365: "+linenumber" syntax, or has other differences in invocation syntax,
! 1366: the LESSEDIT variable can be changed to modify this default.
! 1367:
! 1368:
! 1369: [1mSECURITY[0m
! 1370: When the environment variable LESSSECURE is set to 1, [4mless[24m runs in a
! 1371: "secure" mode. This means these features are disabled:
! 1372:
! 1373: ! the shell command
! 1374:
! 1375: | the pipe command
! 1376:
! 1377: :e the examine command.
! 1378:
! 1379: v the editing command
! 1380:
! 1381: s -o log files
! 1382:
! 1383: -k use of lesskey files
! 1384:
! 1385: -t use of tags files
! 1386:
! 1387: metacharacters in filenames, such as *
! 1388:
! 1389: filename completion (TAB, ^L)
! 1390:
! 1391: Less can also be compiled to be permanently in "secure" mode.
! 1392:
! 1393:
! 1394: [1mCOMPATIBILITY WITH MORE[0m
! 1395: If the environment variable LESS_IS_MORE is set to 1, or if the program
! 1396: is invoked via a file link named "more", [4mless[24m behaves (mostly) in con-
! 1397: formance with the POSIX "more" command specification. In this mode,
! 1398: less behaves differently in these ways:
! 1399:
! 1400: The -e option works differently. If the -e option is not set, [4mless[0m
! 1401: behaves as if the -E option were set. If the -e option is set, [4mless[0m
! 1402: behaves as if the -e and -F options were set.
! 1403:
! 1404: The -m option works differently. If the -m option is not set, the
! 1405: medium prompt is used, and it is prefixed with the string "--More--".
! 1406: If the -m option is set, the short prompt is used.
! 1407:
! 1408: The -n option acts like the -z option. The normal behavior of the -n
! 1409: option is unavailable in this mode.
! 1410:
! 1411: The parameter to the -p option is taken to be a [4mless[24m command rather
! 1412: than a search pattern.
! 1413:
! 1414: The LESS environment variable is ignored, and the MORE environment
! 1415: variable is used in its place.
! 1416:
! 1417:
! 1418: [1mENVIRONMENT VARIABLES[0m
! 1419: Environment variables may be specified either in the system environment
! 1420: as usual, or in a [4mlesskey[24m (1) file. If environment variables are
! 1421: defined in more than one place, variables defined in a local lesskey
! 1422: file take precedence over variables defined in the system environment,
! 1423: which take precedence over variables defined in the system-wide lesskey
! 1424: file.
! 1425:
! 1426: COLUMNS
! 1427: Sets the number of columns on the screen. Takes precedence over
! 1428: the number of columns specified by the TERM variable. (But if
! 1429: you have a windowing system which supports TIOCGWINSZ or
! 1430: WIOCGETD, the window system's idea of the screen size takes
! 1431: precedence over the LINES and COLUMNS environment variables.)
! 1432:
! 1433: EDITOR The name of the editor (used for the v command).
! 1434:
! 1435: HOME Name of the user's home directory (used to find a lesskey file
! 1436: on Unix and OS/2 systems).
! 1437:
! 1438: HOMEDRIVE, HOMEPATH
! 1439: Concatenation of the HOMEDRIVE and HOMEPATH environment vari-
! 1440: ables is the name of the user's home directory if the HOME vari-
! 1441: able is not set (only in the Windows version).
! 1442:
! 1443: INIT Name of the user's init directory (used to find a lesskey file
! 1444: on OS/2 systems).
! 1445:
! 1446: LANG Language for determining the character set.
! 1447:
! 1448: LC_CTYPE
! 1449: Language for determining the character set.
! 1450:
! 1451: LESS Options which are passed to [4mless[24m automatically.
! 1452:
! 1453: LESSANSIENDCHARS
! 1454: Characters which may end an ANSI color escape sequence (default
! 1455: "m").
! 1456:
! 1457: LESSANSIMIDCHARS
! 1458: Characters which may appear between the ESC character and the
! 1459: end character in an ANSI color escape sequence (default
! 1460: "0123456789;[?!"'#%()*+ ".
! 1461:
! 1462: LESSBINFMT
! 1463: Format for displaying non-printable, non-control characters.
! 1464:
! 1465: LESSCHARDEF
! 1466: Defines a character set.
! 1467:
! 1468: LESSCHARSET
! 1469: Selects a predefined character set.
! 1470:
! 1471: LESSCLOSE
! 1472: Command line to invoke the (optional) input-postprocessor.
! 1473:
! 1474: LESSECHO
! 1475: Name of the lessecho program (default "lessecho"). The lessecho
! 1476: program is needed to expand metacharacters, such as * and ?, in
! 1477: filenames on Unix systems.
! 1478:
! 1479: LESSEDIT
! 1480: Editor prototype string (used for the v command). See discus-
! 1481: sion under PROMPTS.
! 1482:
! 1483: LESSGLOBALTAGS
! 1484: Name of the command used by the -t option to find global tags.
! 1485: Normally should be set to "global" if your system has the [4mglobal[0m
! 1486: (1) command. If not set, global tags are not used.
! 1487:
! 1488: LESSHISTFILE
! 1489: Name of the history file used to remember search commands and
! 1490: shell commands between invocations of [4mless.[24m If set to "-" or
! 1491: "/dev/null", a history file is not used. The default is
! 1492: "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on DOS and
! 1493: Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
! 1494: on OS/2 systems.
! 1495:
! 1496: LESSHISTSIZE
! 1497: The maximum number of commands to save in the history file. The
! 1498: default is 100.
! 1499:
! 1500: LESSKEY
! 1501: Name of the default lesskey(1) file.
! 1502:
! 1503: LESSKEY_SYSTEM
! 1504: Name of the default system-wide lesskey(1) file.
! 1505:
! 1506: LESSMETACHARS
! 1507: List of characters which are considered "metacharacters" by the
! 1508: shell.
! 1509:
! 1510: LESSMETAESCAPE
! 1511: Prefix which less will add before each metacharacter in a com-
! 1512: mand sent to the shell. If LESSMETAESCAPE is an empty string,
! 1513: commands containing metacharacters will not be passed to the
! 1514: shell.
! 1515:
! 1516: LESSOPEN
! 1517: Command line to invoke the (optional) input-preprocessor.
! 1518:
! 1519: LESSSECURE
! 1520: Runs less in "secure" mode. See discussion under SECURITY.
! 1521:
! 1522: LESSSEPARATOR
! 1523: String to be appended to a directory name in filename comple-
! 1524: tion.
! 1525:
! 1526: LESSUTFBINFMT
! 1527: Format for displaying non-printable Unicode code points.
! 1528:
! 1529: LESS_IS_MORE
! 1530: Emulate the [4mmore[24m (1) command.
! 1531:
! 1532: LINES Sets the number of lines on the screen. Takes precedence over
! 1533: the number of lines specified by the TERM variable. (But if you
! 1534: have a windowing system which supports TIOCGWINSZ or WIOCGETD,
! 1535: the window system's idea of the screen size takes precedence
! 1536: over the LINES and COLUMNS environment variables.)
! 1537:
! 1538: PATH User's search path (used to find a lesskey file on MS-DOS and
! 1539: OS/2 systems).
! 1540:
! 1541: SHELL The shell used to execute the ! command, as well as to expand
! 1542: filenames.
! 1543:
! 1544: TERM The type of terminal on which [4mless[24m is being run.
! 1545:
! 1546: VISUAL The name of the editor (used for the v command).
! 1547:
! 1548:
! 1549: [1mSEE ALSO[0m
! 1550: lesskey(1)
! 1551:
! 1552:
! 1553: [1mCOPYRIGHT[0m
! 1554: Copyright (C) 1984-2011 Mark Nudelman
! 1555:
! 1556: less is part of the GNU project and is free software. You can redis-
! 1557: tribute it and/or modify it under the terms of either (1) the GNU Gen-
! 1558: eral Public License as published by the Free Software Foundation; or
! 1559: (2) the Less License. See the file README in the less distribution for
! 1560: more details regarding redistribution. You should have received a copy
! 1561: of the GNU General Public License along with the source for less; see
! 1562: the file COPYING. If not, write to the Free Software Foundation, 59
! 1563: Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
! 1564: have received a copy of the Less License; see the file LICENSE.
! 1565:
! 1566: less is distributed in the hope that it will be useful, but WITHOUT ANY
! 1567: WARRANTY; without even the implied warranty of MERCHANTABILITY or FIT-
! 1568: NESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
! 1569: more details.
! 1570:
! 1571:
! 1572: [1mAUTHOR[0m
! 1573: Mark Nudelman <markn@greenwoodsoftware.com>
! 1574: Send bug reports or comments to the above address or to bug-
! 1575: less@gnu.org.
! 1576: See http://www.greenwoodsoftware.com/less/bugs.html for the latest list
! 1577: of known bugs in less.
! 1578: For more information, see the less homepage at
! 1579: http://www.greenwoodsoftware.com/less.
1.1 etheisen 1580:
1581:
1582:
1.1.1.2 ! shadchin 1583: Version 444: 09 Jun 2011 LESS(1)
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