Annotation of src/usr.bin/less/less.nro, Revision 1.1.1.3
1.1.1.3 ! shadchin 1: .TH LESS 1 "Version 444: 09 Jun 2011"
1.1 etheisen 2: .SH NAME
3: less \- opposite of more
4: .SH SYNOPSIS
1.1.1.3 ! shadchin 5: .B "less \-?"
1.1 etheisen 6: .br
1.1.1.3 ! shadchin 7: .B "less \-\-help"
1.1.1.2 millert 8: .br
1.1.1.3 ! shadchin 9: .B "less \-V"
1.1 etheisen 10: .br
1.1.1.3 ! shadchin 11: .B "less \-\-version"
1.1.1.2 millert 12: .br
1.1.1.3 ! shadchin 13: .B "less [\-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]"
1.1 etheisen 14: .br
1.1.1.3 ! shadchin 15: .B " [\-b \fIspace\fP] [\-h \fIlines\fP] [\-j \fIline\fP] [\-k \fIkeyfile\fP]"
1.1 etheisen 16: .br
1.1.1.3 ! shadchin 17: .B " [\-{oO} \fIlogfile\fP] [\-p \fIpattern\fP] [\-P \fIprompt\fP] [\-t \fItag\fP]"
1.1 etheisen 18: .br
1.1.1.3 ! shadchin 19: .B " [\-T \fItagsfile\fP] [\-x \fItab\fP,...] [\-y \fIlines\fP] [\-[z] \fIlines\fP]"
1.1 etheisen 20: .br
1.1.1.3 ! shadchin 21: .B " [\-# \fIshift\fP] [+[+]\fIcmd\fP] [\-\-] [\fIfilename\fP]..."
1.1.1.2 millert 22: .br
23: (See the OPTIONS section for alternate option syntax with long option names.)
1.1 etheisen 24:
25: .SH DESCRIPTION
26: .I Less
27: is a program similar to
28: .I more
29: (1), but which allows backward movement
30: in the file as well as forward movement.
31: Also,
32: .I less
33: does not have to read the entire input file before starting,
34: so with large input files it starts up faster than text editors like
35: .I vi
36: (1).
37: .I Less
38: uses termcap (or terminfo on some systems),
39: so it can run on a variety of terminals.
40: There is even limited support for hardcopy terminals.
41: (On a hardcopy terminal, lines which should be printed at the top
42: of the screen are prefixed with a caret.)
43: .PP
44: Commands are based on both
45: .I more
46: and
47: .I vi.
48: Commands may be preceded by a decimal number,
49: called N in the descriptions below.
50: The number is used by some commands, as indicated.
51:
52: .SH COMMANDS
53: In the following descriptions, ^X means control-X.
54: ESC stands for the ESCAPE key; for example ESC-v means the
55: two character sequence "ESCAPE", then "v".
56: .IP "h or H"
57: Help: display a summary of these commands.
58: If you forget all the other commands, remember this one.
59: .IP "SPACE or ^V or f or ^F"
1.1.1.3 ! shadchin 60: Scroll forward N lines, default one window (see option \-z below).
1.1 etheisen 61: If N is more than the screen size, only the final screenful is displayed.
62: Warning: some systems use ^V as a special literalization character.
63: .IP "z"
64: Like SPACE, but if N is specified, it becomes the new window size.
1.1.1.2 millert 65: .IP "ESC-SPACE"
66: Like SPACE, but scrolls a full screenful, even if it reaches
67: end-of-file in the process.
1.1.1.3 ! shadchin 68: .IP "ENTER or RETURN or ^N or e or ^E or j or ^J"
1.1 etheisen 69: Scroll forward N lines, default 1.
70: The entire N lines are displayed, even if N is more than the screen size.
71: .IP "d or ^D"
72: Scroll forward N lines, default one half of the screen size.
73: If N is specified, it becomes the new default for
74: subsequent d and u commands.
75: .IP "b or ^B or ESC-v"
1.1.1.3 ! shadchin 76: Scroll backward N lines, default one window (see option \-z below).
1.1 etheisen 77: If N is more than the screen size, only the final screenful is displayed.
78: .IP "w"
79: Like ESC-v, but if N is specified, it becomes the new window size.
80: .IP "y or ^Y or ^P or k or ^K"
81: Scroll backward N lines, default 1.
82: The entire N lines are displayed, even if N is more than the screen size.
83: Warning: some systems use ^Y as a special job control character.
84: .IP "u or ^U"
85: Scroll backward N lines, default one half of the screen size.
86: If N is specified, it becomes the new default for
87: subsequent d and u commands.
1.1.1.2 millert 88: .IP "ESC-) or RIGHTARROW"
89: Scroll horizontally right N characters, default half the screen width
1.1.1.3 ! shadchin 90: (see the \-# option).
1.1.1.2 millert 91: If a number N is specified, it becomes the default for future RIGHTARROW
92: and LEFTARROW commands.
1.1.1.3 ! shadchin 93: While the text is scrolled, it acts as though the \-S option
1.1.1.2 millert 94: (chop lines) were in effect.
95: .IP "ESC-( or LEFTARROW"
96: Scroll horizontally left N characters, default half the screen width
1.1.1.3 ! shadchin 97: (see the \-# option).
1.1.1.2 millert 98: If a number N is specified, it becomes the default for future RIGHTARROW
99: and LEFTARROW commands.
1.1 etheisen 100: .IP "r or ^R or ^L"
101: Repaint the screen.
102: .IP R
103: Repaint the screen, discarding any buffered input.
104: Useful if the file is changing while it is being viewed.
105: .IP "F"
106: Scroll forward, and keep trying to read when the
107: end of file is reached.
108: Normally this command would be used when already at the end of the file.
109: It is a way to monitor the tail of a file which is growing
110: while it is being viewed.
1.1.1.3 ! shadchin 111: (The behavior is similar to the "tail \-f" command.)
1.1 etheisen 112: .IP "g or < or ESC-<"
113: Go to line N in the file, default 1 (beginning of file).
114: (Warning: this may be slow if N is large.)
115: .IP "G or > or ESC->"
116: Go to line N in the file, default the end of the file.
117: (Warning: this may be slow if N is large,
118: or if N is not specified and
119: standard input, rather than a file, is being read.)
120: .IP "p or %"
121: Go to a position N percent into the file.
1.1.1.3 ! shadchin 122: N should be between 0 and 100, and may contain a decimal point.
! 123: .IP "P"
! 124: Go to the line containing byte offset N in the file.
1.1 etheisen 125: .IP "{"
126: If a left curly bracket appears in the top line displayed
127: on the screen,
128: the { command will go to the matching right curly bracket.
129: The matching right curly bracket is positioned on the bottom
130: line of the screen.
131: If there is more than one left curly bracket on the top line,
132: a number N may be used to specify the N-th bracket on the line.
133: .IP "}"
134: If a right curly bracket appears in the bottom line displayed
135: on the screen,
136: the } command will go to the matching left curly bracket.
137: The matching left curly bracket is positioned on the top
138: line of the screen.
139: If there is more than one right curly bracket on the top line,
140: a number N may be used to specify the N-th bracket on the line.
141: .IP "("
142: Like {, but applies to parentheses rather than curly brackets.
143: .IP ")"
144: Like }, but applies to parentheses rather than curly brackets.
145: .IP "["
146: Like {, but applies to square brackets rather than curly brackets.
147: .IP "]"
148: Like }, but applies to square brackets rather than curly brackets.
149: .IP "ESC-^F"
150: Followed by two characters,
151: acts like {, but uses the two characters as open and close brackets,
152: respectively.
153: For example, "ESC ^F < >" could be used to
154: go forward to the > which matches the < in the top displayed line.
155: .IP "ESC-^B"
156: Followed by two characters,
157: acts like }, but uses the two characters as open and close brackets,
158: respectively.
159: For example, "ESC ^B < >" could be used to
160: go backward to the < which matches the > in the bottom displayed line.
161: .IP m
162: Followed by any lowercase letter,
163: marks the current position with that letter.
164: .IP "'"
165: (Single quote.)
166: Followed by any lowercase letter, returns to the position which
167: was previously marked with that letter.
168: Followed by another single quote, returns to the position at
169: which the last "large" movement command was executed.
170: Followed by a ^ or $, jumps to the beginning or end of the
171: file respectively.
172: Marks are preserved when a new file is examined,
173: so the ' command can be used to switch between input files.
174: .IP "^X^X"
175: Same as single quote.
176: .IP /pattern
177: Search forward in the file for the N-th line containing the pattern.
178: N defaults to 1.
179: The pattern is a regular expression, as recognized by
1.1.1.3 ! shadchin 180: the regular expression library supplied by your system.
! 181: The search starts at the first line displayed
! 182: (but see the \-a and \-j options, which change this).
1.1 etheisen 183: .sp
184: Certain characters are special
185: if entered at the beginning of the pattern;
186: they modify the type of search rather than become part of the pattern:
187: .RS
1.1.1.2 millert 188: .IP "^N or !"
1.1 etheisen 189: Search for lines which do NOT match the pattern.
1.1.1.2 millert 190: .IP "^E or *"
1.1 etheisen 191: Search multiple files.
1.1.1.2 millert 192: That is, if the search reaches the END of the current file
1.1 etheisen 193: without finding a match,
194: the search continues in the next file in the command line list.
1.1.1.2 millert 195: .IP "^F or @"
196: Begin the search at the first line of the FIRST file
1.1 etheisen 197: in the command line list,
198: regardless of what is currently displayed on the screen
1.1.1.3 ! shadchin 199: or the settings of the \-a or \-j options.
1.1.1.2 millert 200: .IP "^K"
201: Highlight any text which matches the pattern on the current screen,
202: but don't move to the first match (KEEP current position).
203: .IP "^R"
204: Don't interpret regular expression metacharacters;
205: that is, do a simple textual comparison.
1.1 etheisen 206: .RE
207: .IP ?pattern
208: Search backward in the file for the N-th line containing the pattern.
209: The search starts at the line immediately before the top line displayed.
210: .sp
211: Certain characters are special as in the / command:
212: .RS
1.1.1.2 millert 213: .IP "^N or !"
1.1 etheisen 214: Search for lines which do NOT match the pattern.
1.1.1.2 millert 215: .IP "^E or *"
1.1 etheisen 216: Search multiple files.
217: That is, if the search reaches the beginning of the current file
218: without finding a match,
219: the search continues in the previous file in the command line list.
1.1.1.2 millert 220: .IP "^F or @"
1.1 etheisen 221: Begin the search at the last line of the last file
222: in the command line list,
223: regardless of what is currently displayed on the screen
1.1.1.3 ! shadchin 224: or the settings of the \-a or \-j options.
1.1.1.2 millert 225: .IP "^K"
226: As in forward searches.
227: .IP "^R"
228: As in forward searches.
1.1 etheisen 229: .RE
230: .IP "ESC-/pattern"
231: Same as "/*".
232: .IP "ESC-?pattern"
233: Same as "?*".
234: .IP n
235: Repeat previous search, for N-th line containing the last pattern.
1.1.1.2 millert 236: If the previous search was modified by ^N, the search is made for the
1.1 etheisen 237: N-th line NOT containing the pattern.
1.1.1.2 millert 238: If the previous search was modified by ^E, the search continues
1.1 etheisen 239: in the next (or previous) file if not satisfied in the current file.
1.1.1.2 millert 240: If the previous search was modified by ^R, the search is done
241: without using regular expressions.
242: There is no effect if the previous search was modified by ^F or ^K.
1.1 etheisen 243: .IP N
244: Repeat previous search, but in the reverse direction.
245: .IP "ESC-n"
246: Repeat previous search, but crossing file boundaries.
247: The effect is as if the previous search were modified by *.
248: .IP "ESC-N"
249: Repeat previous search, but in the reverse direction
250: and crossing file boundaries.
251: .IP "ESC-u"
252: Undo search highlighting.
253: Turn off highlighting of strings matching the current search pattern.
254: If highlighting is already off because of a previous ESC-u command,
255: turn highlighting back on.
256: Any search command will also turn highlighting back on.
1.1.1.3 ! shadchin 257: (Highlighting can also be disabled by toggling the \-G option;
1.1 etheisen 258: in that case search commands do not turn highlighting back on.)
1.1.1.3 ! shadchin 259: .IP "&pattern"
! 260: Display only lines which match the pattern;
! 261: lines which do not match the pattern are not displayed.
! 262: If pattern is empty (if you type & immediately followed by ENTER),
! 263: any filtering is turned off, and all lines are displayed.
! 264: While filtering is in effect, an ampersand is displayed at the
! 265: beginning of the prompt,
! 266: as a reminder that some lines in the file may be hidden.
! 267: .sp
! 268: Certain characters are special as in the / command:
! 269: .RS
! 270: .IP "^N or !"
! 271: Display only lines which do NOT match the pattern.
! 272: .IP "^R"
! 273: Don't interpret regular expression metacharacters;
! 274: that is, do a simple textual comparison.
! 275: .RE
1.1 etheisen 276: .IP ":e [filename]"
277: Examine a new file.
278: If the filename is missing, the "current" file (see the :n and :p commands
279: below) from the list of files in the command line is re-examined.
280: A percent sign (%) in the filename is replaced by the name of the
281: current file.
282: A pound sign (#) is replaced by the name of the previously examined file.
1.1.1.2 millert 283: However, two consecutive percent signs are simply
284: replaced with a single percent sign.
285: This allows you to enter a filename that contains a percent sign
286: in the name.
287: Similarly, two consecutive pound signs are replaced with a single pound sign.
1.1 etheisen 288: The filename is inserted into the command line list of files
289: so that it can be seen by subsequent :n and :p commands.
290: If the filename consists of several files, they are all inserted into
291: the list of files and the first one is examined.
1.1.1.2 millert 292: If the filename contains one or more spaces,
293: the entire filename should be enclosed in double quotes
1.1.1.3 ! shadchin 294: (also see the \-" option).
1.1 etheisen 295: .IP "^X^V or E"
296: Same as :e.
297: Warning: some systems use ^V as a special literalization character.
1.1.1.2 millert 298: On such systems, you may not be able to use ^V.
1.1 etheisen 299: .IP ":n"
300: Examine the next file (from the list of files given in the command line).
301: If a number N is specified, the N-th next file is examined.
302: .IP ":p"
303: Examine the previous file in the command line list.
304: If a number N is specified, the N-th previous file is examined.
305: .IP ":x"
306: Examine the first file in the command line list.
307: If a number N is specified, the N-th file in the list is examined.
1.1.1.2 millert 308: .IP ":d"
309: Remove the current file from the list of files.
310: .IP "t"
311: Go to the next tag, if there were more than one matches for the current tag.
312: See the \-t option for more details about tags.
313: .IP "T"
314: Go to the previous tag, if there were more than one matches for the current tag.
1.1 etheisen 315: .IP "= or ^G or :f"
316: Prints some information about the file being viewed,
317: including its name
318: and the line number and byte offset of the bottom line being displayed.
319: If possible, it also prints the length of the file,
320: the number of lines in the file
321: and the percent of the file above the last displayed line.
322: .IP \-
1.1.1.2 millert 323: Followed by one of the command line option letters (see OPTIONS below),
1.1 etheisen 324: this will change the setting of that option
325: and print a message describing the new setting.
1.1.1.2 millert 326: If a ^P (CONTROL-P) is entered immediately after the dash,
327: the setting of the option is changed but no message is printed.
1.1.1.3 ! shadchin 328: If the option letter has a numeric value (such as \-b or \-h),
! 329: or a string value (such as \-P or \-t),
1.1 etheisen 330: a new value may be entered after the option letter.
331: If no new value is entered, a message describing
332: the current setting is printed and nothing is changed.
1.1.1.2 millert 333: .IP \-\-
334: Like the \- command, but takes a long option name (see OPTIONS below)
335: rather than a single option letter.
1.1.1.3 ! shadchin 336: You must press ENTER or RETURN after typing the option name.
1.1.1.2 millert 337: A ^P immediately after the second dash suppresses printing of a
338: message describing the new setting, as in the \- command.
1.1 etheisen 339: .IP \-+
1.1.1.2 millert 340: Followed by one of the command line option letters
1.1 etheisen 341: this will reset the option to its default setting
342: and print a message describing the new setting.
343: (The "\-+\fIX\fP" command does the same thing
344: as "\-+\fIX\fP" on the command line.)
345: This does not work for string-valued options.
1.1.1.2 millert 346: .IP \-\-+
347: Like the \-+ command, but takes a long option name
348: rather than a single option letter.
349: .IP \-!
350: Followed by one of the command line option letters,
1.1 etheisen 351: this will reset the option to the "opposite" of its default setting
352: and print a message describing the new setting.
353: This does not work for numeric or string-valued options.
1.1.1.2 millert 354: .IP \-\-!
355: Like the \-! command, but takes a long option name
356: rather than a single option letter.
1.1 etheisen 357: .IP _
358: (Underscore.)
1.1.1.2 millert 359: Followed by one of the command line option letters,
1.1 etheisen 360: this will print a message describing the current setting of that option.
361: The setting of the option is not changed.
1.1.1.2 millert 362: .IP __
363: (Double underscore.)
364: Like the _ (underscore) command, but takes a long option name
365: rather than a single option letter.
1.1.1.3 ! shadchin 366: You must press ENTER or RETURN after typing the option name.
1.1 etheisen 367: .IP +cmd
368: Causes the specified cmd to be executed each time a new file is examined.
369: For example, +G causes
370: .I less
371: to initially display each file starting at the end
372: rather than the beginning.
373: .IP V
374: Prints the version number of
375: .I less
376: being run.
1.1.1.2 millert 377: .IP "q or Q or :q or :Q or ZZ"
1.1 etheisen 378: Exits
379: .I less.
380: .PP
381: The following
1.1.1.2 millert 382: four
1.1 etheisen 383: commands may or may not be valid, depending on your particular installation.
384: .PP
385: .IP v
386: Invokes an editor to edit the current file being viewed.
387: The editor is taken from the environment variable VISUAL if defined,
388: or EDITOR if VISUAL is not defined,
389: or defaults to "vi" if neither VISUAL nor EDITOR is defined.
390: See also the discussion of LESSEDIT under the section on PROMPTS below.
391: .IP "! shell-command"
392: Invokes a shell to run the shell-command given.
393: A percent sign (%) in the command is replaced by the name of the
394: current file.
395: A pound sign (#) is replaced by the name of the previously examined file.
396: "!!" repeats the last shell command.
397: "!" with no shell command simply invokes a shell.
1.1.1.2 millert 398: On Unix systems, the shell is taken from the environment variable SHELL,
1.1 etheisen 399: or defaults to "sh".
1.1.1.2 millert 400: On MS-DOS and OS/2 systems, the shell is the normal command processor.
1.1 etheisen 401: .IP "| <m> shell-command"
402: <m> represents any mark letter.
403: Pipes a section of the input file to the given shell command.
404: The section of the file to be piped is between the first line on
405: the current screen and the position marked by the letter.
406: <m> may also be ^ or $ to indicate beginning or end of file respectively.
407: If <m> is . or newline, the current screen is piped.
1.1.1.2 millert 408: .IP "s filename"
409: Save the input to a file.
410: This only works if the input is a pipe, not an ordinary file.
1.1 etheisen 411: .PP
412: .SH OPTIONS
413: Command line options are described below.
414: Most options may be changed while
415: .I less
416: is running, via the "\-" command.
417: .PP
1.1.1.2 millert 418: Most options may be given in one of two forms:
419: either a dash followed by a single letter,
420: or two dashes followed by a long option name.
421: A long option name may be abbreviated as long as
422: the abbreviation is unambiguous.
1.1.1.3 ! shadchin 423: For example, \-\-quit-at-eof may be abbreviated \-\-quit, but not
! 424: --qui, since both \-\-quit-at-eof and \-\-quiet begin with \-\-qui.
! 425: Some long option names are in uppercase, such as \-\-QUIT-AT-EOF, as
! 426: distinct from \-\-quit-at-eof.
1.1.1.2 millert 427: Such option names need only have their first letter capitalized;
428: the remainder of the name may be in either case.
1.1.1.3 ! shadchin 429: For example, \-\-Quit-at-eof is equivalent to \-\-QUIT-AT-EOF.
1.1.1.2 millert 430: .PP
1.1 etheisen 431: Options are also taken from the environment variable "LESS".
432: For example,
1.1.1.3 ! shadchin 433: to avoid typing "less \-options ..." each time
1.1 etheisen 434: .I less
435: is invoked, you might tell
436: .I csh:
437: .sp
438: setenv LESS "-options"
439: .sp
440: or if you use
441: .I sh:
442: .sp
443: LESS="-options"; export LESS
444: .sp
1.1.1.2 millert 445: On MS-DOS, you don't need the quotes, but you should replace any
446: percent signs in the options string by double percent signs.
447: .sp
1.1 etheisen 448: The environment variable is parsed before the command line,
449: so command line options override the LESS environment variable.
450: If an option appears in the LESS variable, it can be reset
1.1.1.2 millert 451: to its default value on the command line by beginning the command
452: line option with "\-+".
453: .sp
1.1.1.3 ! shadchin 454: For options like \-P or \-D which take a following string,
1.1.1.2 millert 455: a dollar sign ($) must be used to signal the end of the string.
1.1.1.3 ! shadchin 456: For example, to set two \-D options on MS-DOS, you must have
1.1.1.2 millert 457: a dollar sign between them, like this:
458: .sp
459: LESS="-Dn9.1$-Ds4.1"
1.1 etheisen 460: .sp
1.1.1.3 ! shadchin 461: .IP "\-? or \-\-help"
1.1 etheisen 462: This option displays a summary of the commands accepted by
463: .I less
464: (the same as the h command).
465: (Depending on how your shell interprets the question mark,
1.1.1.3 ! shadchin 466: it may be necessary to quote the question mark, thus: "\-\e?".)
! 467: .IP "\-a or \-\-search-skip-screen"
! 468: By default, forward searches start at the top of the displayed screen
! 469: and backwards searches start at the bottom of the displayed screen
! 470: (except for repeated searches invoked by the n or N commands,
! 471: which start after or before the "target" line respectively;
! 472: see the \-j option for more about the target line).
! 473: The \-a option causes forward searches to instead start at
! 474: the bottom of the screen
! 475: and backward searches to start at the top of the screen,
1.1 etheisen 476: thus skipping all lines displayed on the screen.
1.1.1.3 ! shadchin 477: .IP "\-A or \-\-SEARCH-SKIP-SCREEN"
! 478: Causes all forward searches (not just non-repeated searches)
! 479: to start just after the target line, and all backward searches
! 480: to start just before the target line.
! 481: Thus, forward searches will skip part of the displayed screen
! 482: (from the first line up to and including the target line).
! 483: Similarly backwards searches will skip the displayed screen
! 484: from the last line up to and including the target line.
! 485: This was the default behavior in less versions prior to 441.
! 486: .IP "\-b\fIn\fP or \-\-buffers=\fIn\fP"
1.1.1.2 millert 487: Specifies the amount of buffer space
1.1 etheisen 488: .I less
1.1.1.2 millert 489: will use for each file, in units of kilobytes (1024 bytes).
490: By default 64K of buffer space is used for each file
1.1.1.3 ! shadchin 491: (unless the file is a pipe; see the \-B option).
! 492: The \-b option specifies instead that \fIn\fP kilobytes of
1.1.1.2 millert 493: buffer space should be used for each file.
1.1.1.3 ! shadchin 494: If \fIn\fP is \-1, buffer space is unlimited; that is,
! 495: the entire file can be read into memory.
! 496: .IP "\-B or \-\-auto-buffers"
1.1 etheisen 497: By default, when data is read from a pipe,
498: buffers are allocated automatically as needed.
499: If a large amount of data is read from the pipe, this can cause
500: a large amount of memory to be allocated.
1.1.1.3 ! shadchin 501: The \-B option disables this automatic allocation of buffers for pipes,
1.1.1.2 millert 502: so that only 64K
1.1.1.3 ! shadchin 503: (or the amount of space specified by the \-b option)
1.1.1.2 millert 504: is used for the pipe.
1.1.1.3 ! shadchin 505: Warning: use of \-B can result in erroneous display, since only the
! 506: most recently viewed part of the piped data is kept in memory;
1.1 etheisen 507: any earlier data is lost.
1.1.1.3 ! shadchin 508: .IP "\-c or \-\-clear-screen"
1.1 etheisen 509: Causes full screen repaints to be painted from the top line down.
510: By default,
511: full screen repaints are done by scrolling from the bottom of the screen.
1.1.1.3 ! shadchin 512: .IP "\-C or \-\-CLEAR-SCREEN"
! 513: Same as \-c, for compatibility with older versions of
! 514: .I less.
! 515: .IP "\-d or \-\-dumb"
! 516: The \-d option suppresses the error message
1.1 etheisen 517: normally displayed if the terminal is dumb;
518: that is, lacks some important capability,
519: such as the ability to clear the screen or scroll backward.
1.1.1.3 ! shadchin 520: The \-d option does not otherwise change the behavior of
1.1 etheisen 521: .I less
1.1.1.2 millert 522: on a dumb terminal.
1.1.1.3 ! shadchin 523: .IP "\-D\fBx\fP\fIcolor\fP or \-\-color=\fBx\fP\fIcolor\fP"
1.1 etheisen 524: [MS-DOS only]
525: Sets the color of the text displayed.
526: \fBx\fP is a single character which selects the type of text whose color is
527: being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
528: \fIcolor\fP is a pair of numbers separated by a period.
529: The first number selects the foreground color and the second selects
530: the background color of the text.
1.1.1.3 ! shadchin 531: A single number \fIN\fP is the same as \fIN.M\fP,
! 532: where \fIM\fP is the normal background color.
! 533:
! 534: .IP "\-e or \-\-quit-at-eof"
1.1 etheisen 535: Causes
536: .I less
537: to automatically exit
538: the second time it reaches end-of-file.
539: By default, the only way to exit
540: .I less
541: is via the "q" command.
1.1.1.3 ! shadchin 542: .IP "\-E or \-\-QUIT-AT-EOF"
1.1 etheisen 543: Causes
544: .I less
545: to automatically exit the first time it reaches end-of-file.
1.1.1.3 ! shadchin 546: .IP "\-f or \-\-force"
1.1 etheisen 547: Forces non-regular files to be opened.
548: (A non-regular file is a directory or a device special file.)
549: Also suppresses the warning message when a binary file is opened.
550: By default,
551: .I less
552: will refuse to open non-regular files.
1.1.1.3 ! shadchin 553: Note that some operating systems will not allow directories
! 554: to be read, even if \-f is set.
! 555: .IP "\-F or \-\-quit-if-one-screen"
1.1.1.2 millert 556: Causes
557: .I less
558: to automatically exit
559: if the entire file can be displayed on the first screen.
1.1.1.3 ! shadchin 560: .IP "\-g or \-\-hilite-search"
1.1 etheisen 561: Normally,
562: .I less
563: will highlight ALL strings which match the last search command.
1.1.1.3 ! shadchin 564: The \-g option changes this behavior to highlight only the particular string
1.1 etheisen 565: which was found by the last search command.
566: This can cause
567: .I less
568: to run somewhat faster than the default.
1.1.1.3 ! shadchin 569: .IP "\-G or \-\-HILITE-SEARCH"
! 570: The \-G option suppresses all highlighting of strings found by search commands.
! 571: .IP "\-h\fIn\fP or \-\-max-back-scroll=\fIn\fP"
1.1 etheisen 572: Specifies a maximum number of lines to scroll backward.
573: If it is necessary to scroll backward more than \fIn\fP lines,
574: the screen is repainted in a forward direction instead.
575: (If the terminal does not have the ability to scroll
1.1.1.3 ! shadchin 576: backward, \-h0 is implied.)
! 577: .IP "\-i or \-\-ignore-case"
1.1 etheisen 578: Causes searches to ignore case; that is,
579: uppercase and lowercase are considered identical.
580: This option is ignored if any uppercase letters
581: appear in the search pattern;
582: in other words,
583: if a pattern contains uppercase letters, then that search does not ignore case.
1.1.1.3 ! shadchin 584: .IP "\-I or \-\-IGNORE-CASE"
! 585: Like \-i, but searches ignore case even if
1.1 etheisen 586: the pattern contains uppercase letters.
1.1.1.3 ! shadchin 587: .IP "\-j\fIn\fP or \-\-jump-target=\fIn\fP"
1.1 etheisen 588: Specifies a line on the screen where the "target" line
589: is to be positioned.
1.1.1.3 ! shadchin 590: The target line is the line specified by any command to
! 591: search for a pattern, jump to a line number,
! 592: jump to a file percentage or jump to a tag.
! 593: The screen line may be specified by a number: the top line on the screen
1.1 etheisen 594: is 1, the next is 2, and so on.
595: The number may be negative to specify a line relative to the bottom
1.1.1.3 ! shadchin 596: of the screen: the bottom line on the screen is \-1, the second
! 597: to the bottom is \-2, and so on.
! 598: Alternately, the screen line may be specified as a fraction of the height
! 599: of the screen, starting with a decimal point: .5 is in the middle of the
! 600: screen, .3 is three tenths down from the first line, and so on.
! 601: If the line is specified as a fraction, the actual line number
! 602: is recalculated if the terminal window is resized, so that the
! 603: target line remains at the specified fraction of the screen height.
! 604: If any form of the \-j option is used,
! 605: forward searches begin at the line immediately after the target line,
! 606: and backward searches begin at the target line,
! 607: unless changed by \-a or \-A.
! 608: For example, if "\-j4" is used, the target line is the
! 609: fourth line on the screen, so forward searches begin at the fifth line
1.1 etheisen 610: on the screen.
1.1.1.3 ! shadchin 611: .IP "\-J or \-\-status-column"
1.1.1.2 millert 612: Displays a status column at the left edge of the screen.
613: The status column shows the lines that matched the current search.
1.1.1.3 ! shadchin 614: The status column is also used if the \-w or \-W option is in effect.
! 615: .IP "\-k\fIfilename\fP or \-\-lesskey-file=\fIfilename\fP"
1.1 etheisen 616: Causes
617: .I less
618: to open and interpret the named file as a
619: .I lesskey
620: (1) file.
1.1.1.3 ! shadchin 621: Multiple \-k options may be specified.
1.1.1.2 millert 622: If the LESSKEY or LESSKEY_SYSTEM environment variable is set, or
623: if a lesskey file is found in a standard place (see KEY BINDINGS),
624: it is also used as a
1.1 etheisen 625: .I lesskey
626: file.
1.1.1.3 ! shadchin 627: .IP "\-K or \-\-quit-on-intr"
! 628: Causes
! 629: .I less
! 630: to exit immediately (with status 2)
! 631: when an interrupt character (usually ^C) is typed.
! 632: Normally, an interrupt character causes
! 633: .I less
! 634: to stop whatever it is doing and return to its command prompt.
! 635: Note that use of this option makes it impossible to return to the
! 636: command prompt from the "F" command.
! 637: .IP "\-L or \-\-no-lessopen"
1.1.1.2 millert 638: Ignore the LESSOPEN environment variable
639: (see the INPUT PREPROCESSOR section below).
640: This option can be set from within \fIless\fP,
641: but it will apply only to files opened subsequently, not to the
642: file which is currently open.
1.1.1.3 ! shadchin 643: .IP "\-m or \-\-long-prompt"
1.1 etheisen 644: Causes
645: .I less
646: to prompt verbosely (like \fImore\fP),
647: with the percent into the file.
648: By default,
649: .I less
650: prompts with a colon.
1.1.1.3 ! shadchin 651: .IP "\-M or \-\-LONG-PROMPT"
1.1 etheisen 652: Causes
653: .I less
654: to prompt even more verbosely than
655: .I more.
1.1.1.3 ! shadchin 656: .IP "\-n or \-\-line-numbers"
1.1 etheisen 657: Suppresses line numbers.
658: The default (to use line numbers) may cause
659: .I less
660: to run more slowly in some cases, especially with a very large input file.
1.1.1.3 ! shadchin 661: Suppressing line numbers with the \-n option will avoid this problem.
1.1 etheisen 662: Using line numbers means: the line number will be displayed in the verbose
663: prompt and in the = command,
664: and the v command will pass the current line number to the editor
665: (see also the discussion of LESSEDIT in PROMPTS below).
1.1.1.3 ! shadchin 666: .IP "\-N or \-\-LINE-NUMBERS"
1.1 etheisen 667: Causes a line number to be displayed at the beginning of
668: each line in the display.
1.1.1.3 ! shadchin 669: .IP "\-o\fIfilename\fP or \-\-log-file=\fIfilename\fP"
1.1 etheisen 670: Causes
671: .I less
672: to copy its input to the named file as it is being viewed.
673: This applies only when the input file is a pipe,
674: not an ordinary file.
675: If the file already exists,
676: .I less
677: will ask for confirmation before overwriting it.
1.1.1.3 ! shadchin 678: .IP "\-O\fIfilename\fP or \-\-LOG-FILE=\fIfilename\fP"
! 679: The \-O option is like \-o, but it will overwrite an existing
1.1 etheisen 680: file without asking for confirmation.
681: .sp
682: If no log file has been specified,
1.1.1.3 ! shadchin 683: the \-o and \-O options can be used from within
1.1 etheisen 684: .I less
685: to specify a log file.
686: Without a file name, they will simply report the name of the log file.
1.1.1.3 ! shadchin 687: The "s" command is equivalent to specifying \-o from within
1.1 etheisen 688: .I less.
1.1.1.3 ! shadchin 689: .IP "\-p\fIpattern\fP or \-\-pattern=\fIpattern\fP"
! 690: The \-p option on the command line is equivalent to
1.1 etheisen 691: specifying +/\fIpattern\fP;
692: that is, it tells
693: .I less
694: to start at the first occurrence of \fIpattern\fP in the file.
1.1.1.3 ! shadchin 695: .IP "\-P\fIprompt\fP or \-\-prompt=\fIprompt\fP"
1.1 etheisen 696: Provides a way to tailor the three prompt
697: styles to your own preference.
698: This option would normally be put in the LESS environment
699: variable, rather than being typed in with each
700: .I less
701: command.
702: Such an option must either be the last option in the LESS variable,
703: or be terminated by a dollar sign.
1.1.1.2 millert 704: -Ps followed by a string changes the default (short) prompt
705: to that string.
1.1.1.3 ! shadchin 706: -Pm changes the medium (\-m) prompt.
! 707: -PM changes the long (\-M) prompt.
1.1.1.2 millert 708: -Ph changes the prompt for the help screen.
709: -P= changes the message printed by the = command.
710: -Pw changes the message printed while waiting for data (in the F command).
1.1 etheisen 711: All prompt strings consist of a sequence of
712: letters and special escape sequences.
713: See the section on PROMPTS for more details.
1.1.1.3 ! shadchin 714: .IP "\-q or \-\-quiet or \-\-silent"
1.1 etheisen 715: Causes moderately "quiet" operation:
716: the terminal bell is not rung
717: if an attempt is made to scroll past the end of the file
718: or before the beginning of the file.
719: If the terminal has a "visual bell", it is used instead.
720: The bell will be rung on certain other errors,
721: such as typing an invalid character.
722: The default is to ring the terminal bell in all such cases.
1.1.1.3 ! shadchin 723: .IP "\-Q or \-\-QUIET or \-\-SILENT"
1.1 etheisen 724: Causes totally "quiet" operation:
725: the terminal bell is never rung.
1.1.1.3 ! shadchin 726: .IP "\-r or \-\-raw-control-chars"
1.1 etheisen 727: Causes "raw" control characters to be displayed.
728: The default is to display control characters using the caret notation;
729: for example, a control-A (octal 001) is displayed as "^A".
1.1.1.3 ! shadchin 730: Warning: when the \-r option is used,
1.1 etheisen 731: .I less
732: cannot keep track of the actual appearance of the screen
733: (since this depends on how the screen responds to
734: each type of control character).
735: Thus, various display problems may result,
736: such as long lines being split in the wrong place.
1.1.1.3 ! shadchin 737: .IP "\-R or \-\-RAW-CONTROL-CHARS"
! 738: Like \-r, but only ANSI "color" escape sequences are output in "raw" form.
! 739: Unlike \-r, the screen appearance is maintained correctly in most cases.
! 740: ANSI "color" escape sequences are sequences of the form:
1.1.1.2 millert 741: .sp
742: ESC [ ... m
743: .sp
1.1.1.3 ! shadchin 744: where the "..." is zero or more color specification characters
1.1.1.2 millert 745: For the purpose of keeping track of screen appearance,
1.1.1.3 ! shadchin 746: ANSI color escape sequences are assumed to not move the cursor.
1.1.1.2 millert 747: You can make
748: .I less
749: think that characters other than "m" can end ANSI color escape sequences
750: by setting the environment variable LESSANSIENDCHARS to the list of
751: characters which can end a color escape sequence.
1.1.1.3 ! shadchin 752: And you can make
! 753: .I less
! 754: think that characters other than the standard ones may appear between
! 755: the ESC and the m by setting the environment variable LESSANSIMIDCHARS
! 756: to the list of characters which can appear.
! 757: .IP "\-s or \-\-squeeze-blank-lines"
1.1 etheisen 758: Causes consecutive blank lines to be squeezed into a single blank line.
759: This is useful when viewing
760: .I nroff
761: output.
1.1.1.3 ! shadchin 762: .IP "\-S or \-\-chop-long-lines"
1.1 etheisen 763: Causes lines longer than the screen width to be
764: chopped rather than folded.
1.1.1.2 millert 765: That is, the portion of a long line that does not fit in
766: the screen width is not shown.
1.1 etheisen 767: The default is to fold long lines; that is, display the remainder
768: on the next line.
1.1.1.3 ! shadchin 769: .IP "\-t\fItag\fP or \-\-tag=\fItag\fP"
! 770: The \-t option, followed immediately by a TAG,
1.1 etheisen 771: will edit the file containing that tag.
1.1.1.2 millert 772: For this to work, tag information must be available;
773: for example, there may be a file in the current directory called "tags",
774: which was previously built by
1.1 etheisen 775: .I ctags
1.1.1.2 millert 776: (1) or an equivalent command.
777: If the environment variable LESSGLOBALTAGS is set, it is taken to be
778: the name of a command compatible with
779: .I global
780: (1), and that command is executed to find the tag.
781: (See http://www.gnu.org/software/global/global.html).
1.1.1.3 ! shadchin 782: The \-t option may also be specified from within
1.1 etheisen 783: .I less
784: (using the \- command) as a way of examining a new file.
1.1.1.3 ! shadchin 785: The command ":t" is equivalent to specifying \-t from within
1.1 etheisen 786: .I less.
1.1.1.3 ! shadchin 787: .IP "\-T\fItagsfile\fP or \-\-tag-file=\fItagsfile\fP"
1.1 etheisen 788: Specifies a tags file to be used instead of "tags".
1.1.1.3 ! shadchin 789: .IP "\-u or \-\-underline-special"
1.1 etheisen 790: Causes backspaces and carriage returns to be treated as printable characters;
791: that is, they are sent to the terminal when they appear in the input.
1.1.1.3 ! shadchin 792: .IP "\-U or \-\-UNDERLINE-SPECIAL"
1.1.1.2 millert 793: Causes backspaces, tabs and carriage returns to be
794: treated as control characters;
1.1.1.3 ! shadchin 795: that is, they are handled as specified by the \-r option.
1.1 etheisen 796: .sp
1.1.1.3 ! shadchin 797: By default, if neither \-u nor \-U is given,
1.1 etheisen 798: backspaces which appear adjacent to an underscore character
799: are treated specially:
800: the underlined text is displayed
801: using the terminal's hardware underlining capability.
802: Also, backspaces which appear between two identical characters
803: are treated specially:
804: the overstruck text is printed
805: using the terminal's hardware boldface capability.
806: Other backspaces are deleted, along with the preceding character.
807: Carriage returns immediately followed by a newline are deleted.
1.1.1.3 ! shadchin 808: other carriage returns are handled as specified by the \-r option.
1.1 etheisen 809: Text which is overstruck or underlined can be searched for
1.1.1.3 ! shadchin 810: if neither \-u nor \-U is in effect.
! 811: .IP "\-V or \-\-version"
1.1 etheisen 812: Displays the version number of
813: .I less.
1.1.1.3 ! shadchin 814: .IP "\-w or \-\-hilite-unread"
1.1.1.2 millert 815: Temporarily highlights the first "new" line after a forward movement
816: of a full page.
817: The first "new" line is the line immediately following the line previously
818: at the bottom of the screen.
819: Also highlights the target line after a g or p command.
820: The highlight is removed at the next command which causes movement.
1.1.1.3 ! shadchin 821: The entire line is highlighted, unless the \-J option is in effect,
1.1.1.2 millert 822: in which case only the status column is highlighted.
1.1.1.3 ! shadchin 823: .IP "\-W or \-\-HILITE-UNREAD"
! 824: Like \-w, but temporarily highlights the first new line after any
1.1.1.2 millert 825: forward movement command larger than one line.
1.1.1.3 ! shadchin 826: .IP "\-x\fIn\fP,... or \-\-tabs=\fIn\fP,..."
1.1.1.2 millert 827: Sets tab stops.
828: If only one \fIn\fP is specified, tab stops are set at multiples of \fIn\fP.
829: If multiple values separated by commas are specified, tab stops
830: are set at those positions, and then continue with the same spacing as the
831: last two.
832: For example, \fI-x9,17\fP will set tabs at positions 9, 17, 25, 33, etc.
1.1 etheisen 833: The default for \fIn\fP is 8.
1.1.1.3 ! shadchin 834: .IP "\-X or \-\-no-init"
1.1 etheisen 835: Disables sending the termcap initialization and deinitialization strings
836: to the terminal.
837: This is sometimes desirable if the deinitialization string does
838: something unnecessary, like clearing the screen.
1.1.1.3 ! shadchin 839: .IP "\-y\fIn\fP or \-\-max-forw-scroll=\fIn\fP"
1.1 etheisen 840: Specifies a maximum number of lines to scroll forward.
841: If it is necessary to scroll forward more than \fIn\fP lines,
842: the screen is repainted instead.
1.1.1.3 ! shadchin 843: The \-c or \-C option may be used to repaint from the top of
1.1 etheisen 844: the screen if desired.
845: By default, any forward movement causes scrolling.
1.1.1.3 ! shadchin 846: .IP "\-[z]\fIn\fP or \-\-window=\fIn\fP"
1.1 etheisen 847: Changes the default scrolling window size to \fIn\fP lines.
848: The default is one screenful.
849: The z and w commands can also be used to change the window size.
1.1.1.3 ! shadchin 850: The "z" may be omitted for compatibility with some versions of
1.1 etheisen 851: .I more.
852: If the number
853: .I n
854: is negative, it indicates
855: .I n
856: lines less than the current screen size.
1.1.1.3 ! shadchin 857: For example, if the screen is 24 lines, \fI\-z-4\fP sets the
1.1 etheisen 858: scrolling window to 20 lines. If the screen is resized to 40 lines,
859: the scrolling window automatically changes to 36 lines.
1.1.1.3 ! shadchin 860: .IP "\-\fI\(dqcc\fP\ or\ \-\-quotes=\fIcc\fP"
1.1.1.2 millert 861: Changes the filename quoting character.
862: This may be necessary if you are trying to name a file
863: which contains both spaces and quote characters.
864: Followed by a single character, this changes the quote character to that
865: character.
866: Filenames containing a space should then be surrounded by that character
867: rather than by double quotes.
868: Followed by two characters, changes the open quote to the first character,
869: and the close quote to the second character.
870: Filenames containing a space should then be preceded by the open quote
871: character and followed by the close quote character.
872: Note that even after the quote characters are changed, this option
1.1.1.3 ! shadchin 873: remains \-" (a dash followed by a double quote).
! 874: .IP "\-~ or \-\-tilde"
1.1.1.2 millert 875: Normally lines after end of file are displayed as a single tilde (~).
876: This option causes lines after end of file to be displayed as blank lines.
1.1.1.3 ! shadchin 877: .IP "\-# or \-\-shift"
1.1.1.2 millert 878: Specifies the default number of positions to scroll horizontally
879: in the RIGHTARROW and LEFTARROW commands.
880: If the number specified is zero, it sets the default number of
881: positions to one half of the screen width.
1.1.1.3 ! shadchin 882: Alternately, the number may be specified as a fraction of the width
! 883: of the screen, starting with a decimal point: .5 is half of the
! 884: screen width, .3 is three tenths of the screen width, and so on.
! 885: If the number is specified as a fraction, the actual number of
! 886: scroll positions is recalculated if the terminal window is resized,
! 887: so that the actual scroll remains at the specified fraction
! 888: of the screen width.
! 889: .IP "\-\-no-keypad"
! 890: Disables sending the keypad initialization and deinitialization strings
! 891: to the terminal.
! 892: This is sometimes useful if the keypad strings make the numeric
! 893: keypad behave in an undesirable manner.
! 894: .IP "\-\-follow-name"
! 895: Normally, if the input file is renamed while an F command is executing,
! 896: .I less
! 897: will continue to display the contents of the original file despite
! 898: its name change.
! 899: If \-\-follow-name is specified, during an F command
! 900: .I less
! 901: will periodically attempt to reopen the file by name.
! 902: If the reopen succeeds and the file is a different file from the original
! 903: (which means that a new file has been created
! 904: with the same name as the original (now renamed) file),
! 905: .I less
! 906: will display the contents of that new file.
! 907: .IP \-\-
! 908: A command line argument of "\-\-" marks the end of option arguments.
1.1.1.2 millert 909: Any arguments following this are interpreted as filenames.
1.1.1.3 ! shadchin 910: This can be useful when viewing a file whose name begins with a "\-" or "+".
1.1 etheisen 911: .IP +
912: If a command line option begins with \fB+\fP,
913: the remainder of that option is taken to be an initial command to
914: .I less.
915: For example, +G tells
916: .I less
917: to start at the end of the file rather than the beginning,
918: and +/xyz tells it to start at the first occurrence of "xyz" in the file.
919: As a special case, +<number> acts like +<number>g;
920: that is, it starts the display at the specified line number
921: (however, see the caveat under the "g" command above).
922: If the option starts with ++, the initial command applies to
923: every file being viewed, not just the first one.
924: The + command described previously
925: may also be used to set (or change) an initial command for every file.
926:
927: .SH "LINE EDITING"
928: When entering command line at the bottom of the screen
929: (for example, a filename for the :e command,
930: or the pattern for a search command),
931: certain keys can be used to manipulate the command line.
932: Most commands have an alternate form in [ brackets ] which can be used if
933: a key does not exist on a particular keyboard.
1.1.1.3 ! shadchin 934: (Note that the forms beginning with ESC do not work
! 935: in some MS-DOS and Windows systems because ESC is the line erase character.)
1.1 etheisen 936: Any of these special keys may be entered literally by preceding
937: it with the "literal" character, either ^V or ^A.
938: A backslash itself may also be entered literally by entering two backslashes.
939: .IP "LEFTARROW [ ESC-h ]"
940: Move the cursor one space to the left.
941: .IP "RIGHTARROW [ ESC-l ]"
942: Move the cursor one space to the right.
943: .IP "^LEFTARROW [ ESC-b or ESC-LEFTARROW ]"
944: (That is, CONTROL and LEFTARROW simultaneously.)
945: Move the cursor one word to the left.
946: .IP "^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]"
947: (That is, CONTROL and RIGHTARROW simultaneously.)
948: Move the cursor one word to the right.
949: .IP "HOME [ ESC-0 ]"
950: Move the cursor to the beginning of the line.
951: .IP "END [ ESC-$ ]"
952: Move the cursor to the end of the line.
953: .IP "BACKSPACE"
954: Delete the character to the left of the cursor,
955: or cancel the command if the command line is empty.
956: .IP "DELETE or [ ESC-x ]"
957: Delete the character under the cursor.
958: .IP "^BACKSPACE [ ESC-BACKSPACE ]"
959: (That is, CONTROL and BACKSPACE simultaneously.)
960: Delete the word to the left of the cursor.
961: .IP "^DELETE [ ESC-X or ESC-DELETE ]"
962: (That is, CONTROL and DELETE simultaneously.)
963: Delete the word under the cursor.
964: .IP "UPARROW [ ESC-k ]"
965: Retrieve the previous command line.
966: .IP "DOWNARROW [ ESC-j ]"
967: Retrieve the next command line.
968: .IP "TAB"
969: Complete the partial filename to the left of the cursor.
970: If it matches more than one filename, the first match
971: is entered into the command line.
972: Repeated TABs will cycle thru the other matching filenames.
1.1.1.2 millert 973: If the completed filename is a directory, a "/" is appended to the filename.
974: (On MS-DOS systems, a "\e" is appended.)
975: The environment variable LESSSEPARATOR can be used to specify a
976: different character to append to a directory name.
1.1 etheisen 977: .IP "BACKTAB [ ESC-TAB ]"
978: Like, TAB, but cycles in the reverse direction thru the matching filenames.
979: .IP "^L"
980: Complete the partial filename to the left of the cursor.
981: If it matches more than one filename, all matches are entered into
982: the command line (if they fit).
1.1.1.2 millert 983: .IP "^U (Unix and OS/2) or ESC (MS-DOS)"
1.1 etheisen 984: Delete the entire command line,
985: or cancel the command if the command line is empty.
986: If you have changed your line-kill character in Unix to something
987: other than ^U, that character is used instead of ^U.
1.1.1.3 ! shadchin 988: .IP "^G"
! 989: Delete the entire command line and return to the main prompt.
1.1 etheisen 990:
991: .SH "KEY BINDINGS"
992: You may define your own
993: .I less
994: commands by using the program
995: .I lesskey
996: (1)
1.1.1.2 millert 997: to create a lesskey file.
1.1 etheisen 998: This file specifies a set of command keys and an action
999: associated with each key.
1000: You may also use
1001: .I lesskey
1.1.1.2 millert 1002: to change the line-editing keys (see LINE EDITING),
1003: and to set environment variables.
1004: If the environment variable LESSKEY is set,
1005: .I less
1006: uses that as the name of the lesskey file.
1007: Otherwise,
1008: .I less
1009: looks in a standard place for the lesskey file:
1010: On Unix systems,
1011: .I less
1012: looks for a lesskey file called "$HOME/.less".
1013: On MS-DOS and Windows systems,
1014: .I less
1015: looks for a lesskey file called "$HOME/_less", and if it is not found there,
1016: then looks for a lesskey file called "_less" in any directory specified
1017: in the PATH environment variable.
1018: On OS/2 systems,
1019: .I less
1020: looks for a lesskey file called "$HOME/less.ini", and if it is not found,
1021: then looks for a lesskey file called "less.ini" in any directory specified
1022: in the INIT environment variable, and if it not found there,
1023: then looks for a lesskey file called "less.ini" in any directory specified
1024: in the PATH environment variable.
1.1 etheisen 1025: See the
1026: .I lesskey
1027: manual page for more details.
1.1.1.2 millert 1028: .P
1029: A system-wide lesskey file may also be set up to provide key bindings.
1030: If a key is defined in both a local lesskey file and in the
1031: system-wide file, key bindings in the local file take precedence over
1032: those in the system-wide file.
1033: If the environment variable LESSKEY_SYSTEM is set,
1034: .I less
1035: uses that as the name of the system-wide lesskey file.
1036: Otherwise,
1037: .I less
1038: looks in a standard place for the system-wide lesskey file:
1039: On Unix systems, the system-wide lesskey file is /usr/local/etc/sysless.
1040: (However, if
1041: .I less
1042: was built with a different sysconf directory than /usr/local/etc,
1043: that directory is where the sysless file is found.)
1044: On MS-DOS and Windows systems, the system-wide lesskey file is c:\e_sysless.
1045: On OS/2 systems, the system-wide lesskey file is c:\esysless.ini.
1.1 etheisen 1046:
1047: .SH "INPUT PREPROCESSOR"
1048: You may define an "input preprocessor" for
1049: .I less.
1050: Before
1051: .I less
1052: opens a file, it first gives your input preprocessor a chance to modify the
1053: way the contents of the file are displayed.
1054: An input preprocessor is simply an executable program (or shell script),
1055: which writes the contents of the file to a different file,
1056: called the replacement file.
1057: The contents of the replacement file are then displayed
1058: in place of the contents of the original file.
1059: However, it will appear to the user as if the original file is opened;
1060: that is,
1061: .I less
1062: will display the original filename as the name of the current file.
1063: .PP
1064: An input preprocessor receives one command line argument, the original filename,
1065: as entered by the user.
1066: It should create the replacement file, and when finished,
1067: print the name of the replacement file to its standard output.
1068: If the input preprocessor does not output a replacement filename,
1069: .I less
1070: uses the original file, as normal.
1071: The input preprocessor is not called when viewing standard input.
1072: To set up an input preprocessor, set the LESSOPEN environment variable
1073: to a command line which will invoke your input preprocessor.
1074: This command line should include one occurrence of the string "%s",
1075: which will be replaced by the filename
1076: when the input preprocessor command is invoked.
1077: .PP
1078: When
1079: .I less
1080: closes a file opened in such a way, it will call another program,
1081: called the input postprocessor,
1082: which may perform any desired clean-up action (such as deleting the
1083: replacement file created by LESSOPEN).
1084: This program receives two command line arguments, the original filename
1085: as entered by the user, and the name of the replacement file.
1086: To set up an input postprocessor, set the LESSCLOSE environment variable
1087: to a command line which will invoke your input postprocessor.
1088: It may include two occurrences of the string "%s";
1089: the first is replaced with the original name of the file and
1090: the second with the name of the replacement file,
1091: which was output by LESSOPEN.
1092: .PP
1093: For example, on many Unix systems, these two scripts will allow you
1094: to keep files in compressed format, but still let
1095: .I less
1096: view them directly:
1097: .PP
1098: lessopen.sh:
1099: .br
1100: #! /bin/sh
1101: .br
1102: case "$1" in
1103: .br
1.1.1.3 ! shadchin 1104: *.Z) uncompress -\c $1 >/tmp/less.$$ 2>/dev/null
1.1 etheisen 1105: .br
1.1.1.3 ! shadchin 1106: if [ \-s /tmp/less.$$ ]; then
1.1 etheisen 1107: .br
1108: echo /tmp/less.$$
1109: .br
1110: else
1111: .br
1.1.1.3 ! shadchin 1112: rm \-f /tmp/less.$$
1.1 etheisen 1113: .br
1114: fi
1115: .br
1116: ;;
1117: .br
1118: esac
1119: .PP
1120: lessclose.sh:
1121: .br
1122: #! /bin/sh
1123: .br
1124: rm $2
1125: .PP
1126: To use these scripts, put them both where they can be executed and
1127: set LESSOPEN="lessopen.sh\ %s", and
1128: LESSCLOSE="lessclose.sh\ %s\ %s".
1129: More complex LESSOPEN and LESSCLOSE scripts may be written
1130: to accept other types of compressed files, and so on.
1131: .PP
1132: It is also possible to set up an input preprocessor to
1133: pipe the file data directly to
1134: .I less,
1135: rather than putting the data into a replacement file.
1136: This avoids the need to decompress the entire file before
1137: starting to view it.
1138: An input preprocessor that works this way is called an input pipe.
1139: An input pipe, instead of writing the name of a replacement file on
1140: its standard output,
1141: writes the entire contents of the replacement file on its standard output.
1142: If the input pipe does not write any characters on its standard output,
1143: then there is no replacement file and
1144: .I less
1145: uses the original file, as normal.
1146: To use an input pipe,
1147: make the first character in the LESSOPEN environment variable a
1148: vertical bar (|) to signify that the input preprocessor is an input pipe.
1149: .PP
1150: For example, on many Unix systems, this script will work like the
1151: previous example scripts:
1152: .PP
1153: lesspipe.sh:
1154: .br
1.1.1.2 millert 1155: #! /bin/sh
1.1 etheisen 1156: .br
1157: case "$1" in
1158: .br
1.1.1.3 ! shadchin 1159: *.Z) uncompress \-c $1 2>/dev/null
1.1 etheisen 1160: .br
1161: ;;
1162: .br
1163: esac
1164: .br
1165: .PP
1166: To use this script, put it where it can be executed and set
1167: LESSOPEN="|lesspipe.sh %s".
1168: When an input pipe is used, a LESSCLOSE postprocessor can be used,
1169: but it is usually not necessary since there is no replacement file
1170: to clean up.
1171: In this case, the replacement file name passed to the LESSCLOSE
1.1.1.3 ! shadchin 1172: postprocessor is "\-".
! 1173: .PP
! 1174: For compatibility with previous versions of
! 1175: .I less,
! 1176: the input preprocessor or pipe is not used if
! 1177: .I less
! 1178: is viewing standard input.
! 1179: However, if the first character of LESSOPEN is a dash (\-),
! 1180: the input preprocessor is used on standard input as well as other files.
! 1181: In this case, the dash is not considered to be part of
! 1182: the preprocessor command.
! 1183: If standard input is being viewed, the input preprocessor is passed
! 1184: a file name consisting of a single dash.
! 1185: Similarly, if the first two characters of LESSOPEN are vertical bar and dash
! 1186: (|\-), the input pipe is used on standard input as well as other files.
! 1187: Again, in this case the dash is not considered to be part of
! 1188: the input pipe command.
1.1 etheisen 1189:
1190: .SH "NATIONAL CHARACTER SETS"
1191: There are three types of characters in the input file:
1192: .IP "normal characters"
1193: can be displayed directly to the screen.
1194: .IP "control characters"
1195: should not be displayed directly, but are expected to be found
1196: in ordinary text files (such as backspace and tab).
1197: .IP "binary characters"
1198: should not be displayed directly and are not expected to be found
1199: in text files.
1200: .PP
1201: A "character set" is simply a description of which characters are to
1202: be considered normal, control, and binary.
1203: The LESSCHARSET environment variable may be used to select a character set.
1204: Possible values for LESSCHARSET are:
1205: .IP ascii
1206: BS, TAB, NL, CR, and formfeed are control characters,
1.1.1.2 millert 1207: all chars with values between 32 and 126 are normal,
1208: and all others are binary.
1209: .IP iso8859
1210: Selects an ISO 8859 character set.
1211: This is the same as ASCII, except characters between 160 and 255 are
1.1 etheisen 1212: treated as normal characters.
1.1.1.2 millert 1213: .IP latin1
1214: Same as iso8859.
1215: .IP latin9
1216: Same as iso8859.
1.1 etheisen 1217: .IP dos
1218: Selects a character set appropriate for MS-DOS.
1.1.1.2 millert 1219: .IP ebcdic
1220: Selects an EBCDIC character set.
1221: .IP IBM-1047
1222: Selects an EBCDIC character set used by OS/390 Unix Services.
1223: This is the EBCDIC analogue of latin1. You get similar results
1224: by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US
1225: in your environment.
1.1 etheisen 1226: .IP koi8-r
1227: Selects a Russian character set.
1228: .IP next
1229: Selects a character set appropriate for NeXT computers.
1.1.1.2 millert 1230: .IP utf-8
1231: Selects the UTF-8 encoding of the ISO 10646 character set.
1.1.1.3 ! shadchin 1232: UTF-8 is special in that it supports multi-byte characters in the input file.
! 1233: It is the only character set that supports multi-byte characters.
! 1234: .IP windows
! 1235: Selects a character set appropriate for Microsoft Windows (cp 1251).
1.1 etheisen 1236: .PP
1.1.1.3 ! shadchin 1237: In rare cases, it may be desired to tailor
1.1 etheisen 1238: .I less
1239: to use a character set other than the ones definable by LESSCHARSET.
1240: In this case, the environment variable LESSCHARDEF can be used
1241: to define a character set.
1242: It should be set to a string where each character in the string represents
1243: one character in the character set.
1244: The character "." is used for a normal character, "c" for control,
1245: and "b" for binary.
1246: A decimal number may be used for repetition.
1247: For example, "bccc4b." would mean character 0 is binary,
1248: 1, 2 and 3 are control, 4, 5, 6 and 7 are binary, and 8 is normal.
1249: All characters after the last are taken to be the same as the last,
1250: so characters 9 through 255 would be normal.
1251: (This is an example, and does not necessarily
1252: represent any real character set.)
1253: .PP
1254: This table shows the value of LESSCHARDEF which is equivalent
1255: to each of the possible values for LESSCHARSET:
1256: .sp
1257: ascii\ 8bcccbcc18b95.b
1258: .br
1259: dos\ \ \ 8bcccbcc12bc5b95.b.
1260: .br
1.1.1.2 millert 1261: ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
1262: .br
1263: \ \ \ \ \ \ 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
1264: .br
1265: IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
1266: .br
1267: \ \ \ \ \ \ 191.b
1268: .br
1269: iso8859 8bcccbcc18b95.33b.
1270: .br
1.1 etheisen 1271: koi8-r 8bcccbcc18b95.b128.
1272: .br
1.1.1.2 millert 1273: latin1 8bcccbcc18b95.33b.
1274: .br
1.1 etheisen 1275: next\ \ 8bcccbcc18b95.bb125.bb
1276: .PP
1.1.1.2 millert 1277: If neither LESSCHARSET nor LESSCHARDEF is set,
1.1.1.3 ! shadchin 1278: but any of the strings "UTF-8", "UTF8", "utf-8" or "utf8"
! 1279: is found in the LC_ALL, LC_CTYPE or LANG
1.1.1.2 millert 1280: environment variables, then the default character set is utf-8.
1281: .PP
1282: If that string is not found, but your system supports the
1.1 etheisen 1283: .I setlocale
1284: interface,
1285: .I less
1286: will use setlocale to determine the character set.
1.1.1.2 millert 1287: setlocale is controlled by setting the LANG or LC_CTYPE environment
1288: variables.
1289: .PP
1290: Finally, if the
1291: .I setlocale
1292: interface is also not available, the default character set is latin1.
1.1 etheisen 1293: .PP
1294: Control and binary characters are displayed in standout (reverse video).
1295: Each such character is displayed in caret notation if possible
1296: (e.g. ^A for control-A). Caret notation is used only if
1297: inverting the 0100 bit results in a normal printable character.
1298: Otherwise, the character is displayed as a hex number in angle brackets.
1299: This format can be changed by
1300: setting the LESSBINFMT environment variable.
1301: LESSBINFMT may begin with a "*" and one character to select
1302: the display attribute:
1.1.1.2 millert 1303: "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout,
1304: and "*n" is normal.
1.1 etheisen 1305: If LESSBINFMT does not begin with a "*", normal attribute is assumed.
1306: The remainder of LESSBINFMT is a string which may include one
1307: printf-style escape sequence (a % followed by x, X, o, d, etc.).
1308: For example, if LESSBINFMT is "*u[%x]", binary characters
1309: are displayed in underlined hexadecimal surrounded by brackets.
1.1.1.3 ! shadchin 1310: The default if no LESSBINFMT is specified is "*s<%02X>".
! 1311: Warning: the result of expanding the character via LESSBINFMT must
! 1312: be less than 31 characters.
! 1313: .PP
! 1314: When the character set is utf-8, the LESSUTFBINFMT environment variable
! 1315: acts similarly to LESSBINFMT but it applies to Unicode code points
! 1316: that were successfully decoded but are unsuitable for display (e.g.,
! 1317: unassigned code points).
! 1318: Its default value is "<U+%04lX>".
! 1319: Note that LESSUTFBINFMT and LESSBINFMT share their display attribute
! 1320: setting ("*x") so specifying one will affect both;
! 1321: LESSUTFBINFMT is read after LESSBINFMT so its setting, if any,
! 1322: will have priority.
! 1323: Problematic octets in a UTF-8 file (octets of a truncated sequence,
! 1324: octets of a complete but non-shortest form sequence, illegal octets,
! 1325: and stray trailing octets)
! 1326: are displayed individually using LESSBINFMT so as to facilitate diagnostic
! 1327: of how the UTF-8 file is ill-formed.
1.1 etheisen 1328:
1329: .SH "PROMPTS"
1.1.1.3 ! shadchin 1330: The \-P option allows you to tailor the prompt to your preference.
! 1331: The string given to the \-P option replaces the specified prompt string.
1.1 etheisen 1332: Certain characters in the string are interpreted specially.
1333: The prompt mechanism is rather complicated to provide flexibility,
1334: but the ordinary user need not understand the details of constructing
1335: personalized prompt strings.
1336: .sp
1337: A percent sign followed by a single character is expanded
1338: according to what the following character is:
1339: .IP "%b\fIX\fP"
1340: Replaced by the byte offset into the current input file.
1341: The b is followed by a single character (shown as \fIX\fP above)
1342: which specifies the line whose byte offset is to be used.
1343: If the character is a "t", the byte offset of the top line in the
1344: display is used,
1345: an "m" means use the middle line,
1346: a "b" means use the bottom line,
1347: a "B" means use the line just after the bottom line,
1.1.1.3 ! shadchin 1348: and a "j" means use the "target" line, as specified by the \-j option.
1.1 etheisen 1349: .IP "%B"
1350: Replaced by the size of the current input file.
1.1.1.2 millert 1351: .IP "%c"
1352: Replaced by the column number of the text appearing in the first
1353: column of the screen.
1354: .IP "%d\fIX\fP"
1355: Replaced by the page number of a line in the input file.
1356: The line to be used is determined by the \fIX\fP, as with the %b option.
1357: .IP "%D"
1358: Replaced by the number of pages in the input file,
1359: or equivalently, the page number of the last line in the input file.
1.1 etheisen 1360: .IP "%E"
1361: Replaced by the name of the editor (from the VISUAL environment variable,
1362: or the EDITOR environment variable if VISUAL is not defined).
1363: See the discussion of the LESSEDIT feature below.
1364: .IP "%f"
1365: Replaced by the name of the current input file.
1.1.1.3 ! shadchin 1366: .IP "%F"
! 1367: Replaced by the last component of the name of the current input file.
1.1 etheisen 1368: .IP "%i"
1369: Replaced by the index of the current file in the list of
1370: input files.
1371: .IP "%l\fIX\fP"
1372: Replaced by the line number of a line in the input file.
1373: The line to be used is determined by the \fIX\fP, as with the %b option.
1374: .IP "%L"
1375: Replaced by the line number of the last line in the input file.
1376: .IP "%m"
1377: Replaced by the total number of input files.
1378: .IP "%p\fIX\fP"
1.1.1.2 millert 1379: Replaced by the percent into the current input file, based on byte offsets.
1380: The line used is determined by the \fIX\fP as with the %b option.
1381: .IP "%P\fIX\fP"
1382: Replaced by the percent into the current input file, based on line numbers.
1.1 etheisen 1383: The line used is determined by the \fIX\fP as with the %b option.
1384: .IP "%s"
1385: Same as %B.
1386: .IP "%t"
1387: Causes any trailing spaces to be removed.
1388: Usually used at the end of the string, but may appear anywhere.
1389: .IP "%x"
1390: Replaced by the name of the next input file in the list.
1391: .PP
1392: If any item is unknown (for example, the file size if input
1393: is a pipe), a question mark is printed instead.
1394: .PP
1395: The format of the prompt string can be changed
1396: depending on certain conditions.
1397: A question mark followed by a single character acts like an "IF":
1398: depending on the following character, a condition is evaluated.
1399: If the condition is true, any characters following the question mark
1400: and condition character, up to a period, are included in the prompt.
1401: If the condition is false, such characters are not included.
1402: A colon appearing between the question mark and the
1403: period can be used to establish an "ELSE": any characters between
1404: the colon and the period are included in the string if and only if
1405: the IF condition is false.
1406: Condition characters (which follow a question mark) may be:
1407: .IP "?a"
1408: True if any characters have been included in the prompt so far.
1409: .IP "?b\fIX\fP"
1410: True if the byte offset of the specified line is known.
1411: .IP "?B"
1412: True if the size of current input file is known.
1.1.1.2 millert 1413: .IP "?c"
1414: True if the text is horizontally shifted (%c is not zero).
1415: .IP "?d\fIX\fP"
1416: True if the page number of the specified line is known.
1.1 etheisen 1417: .IP "?e"
1418: True if at end-of-file.
1419: .IP "?f"
1420: True if there is an input filename
1421: (that is, if input is not a pipe).
1422: .IP "?l\fIX\fP"
1423: True if the line number of the specified line is known.
1424: .IP "?L"
1425: True if the line number of the last line in the file is known.
1426: .IP "?m"
1427: True if there is more than one input file.
1428: .IP "?n"
1429: True if this is the first prompt in a new input file.
1430: .IP "?p\fIX\fP"
1.1.1.2 millert 1431: True if the percent into the current input file, based on byte offsets,
1432: of the specified line is known.
1433: .IP "?P\fIX\fP"
1434: True if the percent into the current input file, based on line numbers,
1.1 etheisen 1435: of the specified line is known.
1436: .IP "?s"
1437: Same as "?B".
1438: .IP "?x"
1439: True if there is a next input file
1440: (that is, if the current input file is not the last one).
1441: .PP
1442: Any characters other than the special ones
1443: (question mark, colon, period, percent, and backslash)
1444: become literally part of the prompt.
1445: Any of the special characters may be included in the prompt literally
1446: by preceding it with a backslash.
1447: .PP
1448: Some examples:
1449: .sp
1450: ?f%f:Standard input.
1451: .sp
1452: This prompt prints the filename, if known;
1453: otherwise the string "Standard input".
1454: .sp
1.1.1.2 millert 1455: ?f%f .?ltLine %lt:?pt%pt\e%:?btByte %bt:-...
1.1 etheisen 1456: .sp
1457: This prompt would print the filename, if known.
1458: The filename is followed by the line number, if known,
1459: otherwise the percent if known, otherwise the byte offset if known.
1460: Otherwise, a dash is printed.
1461: Notice how each question mark has a matching period,
1462: and how the % after the %pt
1463: is included literally by escaping it with a backslash.
1464: .sp
1.1.1.2 millert 1465: ?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x..%t
1.1 etheisen 1466: .sp
1467: This prints the filename if this is the first prompt in a file,
1468: followed by the "file N of N" message if there is more
1469: than one input file.
1470: Then, if we are at end-of-file, the string "(END)" is printed
1471: followed by the name of the next file, if there is one.
1472: Finally, any trailing spaces are truncated.
1473: This is the default prompt.
1474: For reference, here are the defaults for
1.1.1.3 ! shadchin 1475: the other two prompts (\-m and \-M respectively).
1.1 etheisen 1476: Each is broken into two lines here for readability only.
1477: .nf
1478: .sp
1.1.1.2 millert 1479: ?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x.:
1480: ?pB%pB\e%:byte\ %bB?s/%s...%t
1.1 etheisen 1481: .sp
1.1.1.2 millert 1482: ?f%f\ .?n?m(file\ %i\ of\ %m)\ ..?ltlines\ %lt-%lb?L/%L.\ :
1483: byte\ %bB?s/%s.\ .?e(END)\ ?x-\ Next\e:\ %x.:?pB%pB\e%..%t
1.1 etheisen 1484: .sp
1485: .fi
1486: And here is the default message produced by the = command:
1487: .nf
1488: .sp
1.1.1.2 millert 1489: ?f%f\ .?m(file\ %i\ of\ %m)\ .?ltlines\ %lt-%lb?L/%L.\ .
1490: byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\e%..%t
1.1 etheisen 1491: .fi
1492: .PP
1493: The prompt expansion features are also used for another purpose:
1494: if an environment variable LESSEDIT is defined, it is used
1495: as the command to be executed when the v command is invoked.
1496: The LESSEDIT string is expanded in the same way as the prompt strings.
1497: The default value for LESSEDIT is:
1498: .nf
1499: .sp
1500: %E\ ?lm+%lm.\ %f
1501: .sp
1502: .fi
1503: Note that this expands to the editor name, followed by a + and the
1504: line number, followed by the file name.
1505: If your editor does not accept the "+linenumber" syntax, or has other
1506: differences in invocation syntax, the LESSEDIT variable can be
1507: changed to modify this default.
1508:
1.1.1.2 millert 1509: .SH SECURITY
1510: When the environment variable LESSSECURE is set to 1,
1511: .I less
1512: runs in a "secure" mode.
1513: This means these features are disabled:
1514: .RS
1515: .IP "!"
1516: the shell command
1517: .IP "|"
1518: the pipe command
1519: .IP ":e"
1520: the examine command.
1521: .IP "v"
1522: the editing command
1.1.1.3 ! shadchin 1523: .IP "s \-o"
1.1.1.2 millert 1524: log files
1.1.1.3 ! shadchin 1525: .IP "\-k"
1.1.1.2 millert 1526: use of lesskey files
1.1.1.3 ! shadchin 1527: .IP "\-t"
1.1.1.2 millert 1528: use of tags files
1529: .IP " "
1530: metacharacters in filenames, such as *
1531: .IP " "
1532: filename completion (TAB, ^L)
1533: .RE
1534: .PP
1535: Less can also be compiled to be permanently in "secure" mode.
1536:
1.1.1.3 ! shadchin 1537: .SH "COMPATIBILITY WITH MORE"
! 1538: If the environment variable LESS_IS_MORE is set to 1,
! 1539: or if the program is invoked via a file link named "more",
! 1540: .I less
! 1541: behaves (mostly) in conformance with the POSIX "more" command specification.
! 1542: In this mode, less behaves differently in these ways:
! 1543: .PP
! 1544: The \-e option works differently.
! 1545: If the \-e option is not set,
! 1546: .I less
! 1547: behaves as if the \-E option were set.
! 1548: If the \-e option is set,
! 1549: .I less
! 1550: behaves as if the \-e and \-F options were set.
! 1551: .PP
! 1552: The \-m option works differently.
! 1553: If the \-m option is not set, the medium prompt is used,
! 1554: and it is prefixed with the string "--More--".
! 1555: If the \-m option is set, the short prompt is used.
! 1556: .PP
! 1557: The \-n option acts like the \-z option.
! 1558: The normal behavior of the \-n option is unavailable in this mode.
! 1559: .PP
! 1560: The parameter to the \-p option is taken to be a
! 1561: .I less
! 1562: command rather than a search pattern.
! 1563: .PP
! 1564: The LESS environment variable is ignored,
! 1565: and the MORE environment variable is used in its place.
! 1566:
1.1 etheisen 1567: .SH "ENVIRONMENT VARIABLES"
1.1.1.2 millert 1568: Environment variables may be specified either in the system environment
1569: as usual, or in a
1570: .I lesskey
1571: (1) file.
1572: If environment variables are defined in more than one place,
1573: variables defined in a local lesskey file take precedence over
1574: variables defined in the system environment, which take precedence
1575: over variables defined in the system-wide lesskey file.
1.1 etheisen 1576: .IP COLUMNS
1577: Sets the number of columns on the screen.
1578: Takes precedence over the number of columns specified by the TERM variable.
1579: (But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1580: the window system's idea of the screen size takes precedence over the
1581: LINES and COLUMNS environment variables.)
1582: .IP EDITOR
1583: The name of the editor (used for the v command).
1584: .IP HOME
1.1.1.2 millert 1585: Name of the user's home directory
1586: (used to find a lesskey file on Unix and OS/2 systems).
1587: .IP "HOMEDRIVE, HOMEPATH"
1588: Concatenation of the HOMEDRIVE and HOMEPATH environment variables is
1589: the name of the user's home directory if the HOME variable is not set
1590: (only in the Windows version).
1591: .IP INIT
1592: Name of the user's init directory (used to find a lesskey file on OS/2 systems).
1.1 etheisen 1593: .IP LANG
1594: Language for determining the character set.
1595: .IP LC_CTYPE
1596: Language for determining the character set.
1597: .IP LESS
1.1.1.2 millert 1598: Options which are passed to
1.1 etheisen 1599: .I less
1600: automatically.
1.1.1.2 millert 1601: .IP LESSANSIENDCHARS
1.1.1.3 ! shadchin 1602: Characters which may end an ANSI color escape sequence
1.1.1.2 millert 1603: (default "m").
1.1.1.3 ! shadchin 1604: .IP LESSANSIMIDCHARS
! 1605: Characters which may appear between the ESC character and the
! 1606: end character in an ANSI color escape sequence
! 1607: (default "0123456789;[?!"'#%()*+\ ".
1.1 etheisen 1608: .IP LESSBINFMT
1609: Format for displaying non-printable, non-control characters.
1610: .IP LESSCHARDEF
1611: Defines a character set.
1612: .IP LESSCHARSET
1613: Selects a predefined character set.
1614: .IP LESSCLOSE
1615: Command line to invoke the (optional) input-postprocessor.
1.1.1.2 millert 1616: .IP LESSECHO
1617: Name of the lessecho program (default "lessecho").
1618: The lessecho program is needed to expand metacharacters, such as * and ?,
1619: in filenames on Unix systems.
1.1 etheisen 1620: .IP LESSEDIT
1621: Editor prototype string (used for the v command).
1622: See discussion under PROMPTS.
1.1.1.2 millert 1623: .IP LESSGLOBALTAGS
1.1.1.3 ! shadchin 1624: Name of the command used by the \-t option to find global tags.
1.1.1.2 millert 1625: Normally should be set to "global" if your system has the
1626: .I global
1627: (1) command. If not set, global tags are not used.
1.1.1.3 ! shadchin 1628: .IP LESSHISTFILE
! 1629: Name of the history file used to remember search commands and
! 1630: shell commands between invocations of
! 1631: .I less.
! 1632: If set to "\-" or "/dev/null", a history file is not used.
! 1633: The default is "$HOME/.lesshst" on Unix systems, "$HOME/_lesshst" on
! 1634: DOS and Windows systems, or "$HOME/lesshst.ini" or "$INIT/lesshst.ini"
! 1635: on OS/2 systems.
! 1636: .IP LESSHISTSIZE
! 1637: The maximum number of commands to save in the history file.
! 1638: The default is 100.
1.1.1.2 millert 1639: .IP LESSKEY
1640: Name of the default lesskey(1) file.
1641: .IP LESSKEY_SYSTEM
1642: Name of the default system-wide lesskey(1) file.
1643: .IP LESSMETACHARS
1644: List of characters which are considered "metacharacters" by the shell.
1645: .IP LESSMETAESCAPE
1646: Prefix which less will add before each metacharacter in a
1647: command sent to the shell.
1648: If LESSMETAESCAPE is an empty string, commands containing
1649: metacharacters will not be passed to the shell.
1.1 etheisen 1650: .IP LESSOPEN
1651: Command line to invoke the (optional) input-preprocessor.
1.1.1.2 millert 1652: .IP LESSSECURE
1653: Runs less in "secure" mode.
1654: See discussion under SECURITY.
1655: .IP LESSSEPARATOR
1656: String to be appended to a directory name in filename completion.
1.1.1.3 ! shadchin 1657: .IP LESSUTFBINFMT
! 1658: Format for displaying non-printable Unicode code points.
! 1659: .IP LESS_IS_MORE
! 1660: Emulate the
! 1661: .I more
! 1662: (1) command.
1.1 etheisen 1663: .IP LINES
1664: Sets the number of lines on the screen.
1665: Takes precedence over the number of lines specified by the TERM variable.
1.1.1.2 millert 1666: (But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,
1667: the window system's idea of the screen size takes precedence over the
1668: LINES and COLUMNS environment variables.)
1669: .IP PATH
1670: User's search path (used to find a lesskey file
1671: on MS-DOS and OS/2 systems).
1.1 etheisen 1672: .IP SHELL
1673: The shell used to execute the ! command, as well as to expand filenames.
1674: .IP TERM
1675: The type of terminal on which
1676: .I less
1677: is being run.
1678: .IP VISUAL
1679: The name of the editor (used for the v command).
1680:
1681: .SH "SEE ALSO"
1682: lesskey(1)
1683:
1684: .SH COPYRIGHT
1.1.1.3 ! shadchin 1685: Copyright (C) 1984-2011 Mark Nudelman
1.1.1.2 millert 1686: .PP
1687: less is part of the GNU project and is free software.
1688: You can redistribute it and/or modify it
1689: under the terms of either
1690: (1) the GNU General Public License as published by
1691: the Free Software Foundation; or (2) the Less License.
1692: See the file README in the less distribution for more details
1693: regarding redistribution.
1694: You should have received a copy of the GNU General Public License
1695: along with the source for less; see the file COPYING.
1696: If not, write to the Free Software Foundation, 59 Temple Place,
1697: Suite 330, Boston, MA 02111-1307, USA.
1698: You should also have received a copy of the Less License;
1699: see the file LICENSE.
1700: .PP
1701: less is distributed in the hope that it will be useful, but
1702: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1703: or FITNESS FOR A PARTICULAR PURPOSE.
1704: See the GNU General Public License for more details.
1705:
1706: .SH AUTHOR
1707: .PP
1708: Mark Nudelman <markn@greenwoodsoftware.com>
1709: .br
1710: Send bug reports or comments to the above address or to bug-less@gnu.org.
1711: .br
1.1.1.3 ! shadchin 1712: See http://www.greenwoodsoftware.com/less/bugs.html for the latest list of known bugs in less.
! 1713: .br
! 1714: For more information, see the less homepage at
! 1715: .br
! 1716: http://www.greenwoodsoftware.com/less.
![[BACK]](/icons/back.gif){kind=icon}
Return to less.nro CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / less