less(1) General Commands Manual less(1)

NAME

 less - display the contents of a file in a terminal

SYNOPSIS

 less -?
 less --help
 less -V
 less --version
 less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
 [-b space] [-h lines] [-j line] [-k keyfile]
 [-{oO} logfile] [-p pattern] [-P prompt] [-t tag]
 [-T tagsfile] [-x tab,...] [-y lines] [-[z] lines]
 [-# shift] [+[+]cmd] [--] [filename]...
 (See the OPTIONS section for alternate option syntax with long option
 names.)

DESCRIPTION

 Less is a program similar to more(1) , but it has many more features.
 Less does not have to read the entire input file before starting, so
 with large input files it starts up faster than text editors like
 vi(1) . Less uses termcap (or terminfo on some systems), so it can run
 on a variety of terminals. There is even limited support for hardcopy
 terminals. (On a hardcopy terminal, lines which should be printed at
 the top of the screen are prefixed with a caret.)

COMMANDS

 Commands are based on both more and vi. Commands may be preceded by a
 decimal number, called N in the descriptions below. The number is used
 by some commands, as indicated.
 In the following descriptions, ^X means control-X. ESC stands for the
 ESCAPE key; for example ESC-v means the two character sequence
 "ESCAPE", then "v".
 h or H Help: display a summary of these commands. If you forget all
 the other commands, remember this one.
 SPACE or ^V or f or ^F
 Scroll forward N lines, default one window (see option -z
 below). If N is more than the screen size, only the final
 screenful is displayed. Warning: some systems use ^V as a
 special literalization character.
 z Like SPACE, but if N is specified, it becomes the new window
 size.
 ENTER or RETURN or ^N or e or ^E or j or ^J
 Scroll forward N lines, default 1. The entire N lines are
 displayed, even if N is more than the screen size.
 d or ^D
 Scroll forward N lines, default one half of the screen size. If
 N is specified, it becomes the new default for subsequent d and
 u commands.
 b or ^B or ESC-v
 Scroll backward N lines, default one window (see option -z
 below). If N is more than the screen size, only the final
 screenful is displayed.
 w Like ESC-v, but if N is specified, it becomes the new window
 size.
 y or ^Y or ^P or k or ^K
 Scroll backward N lines, default 1. The entire N lines are
 displayed, even if N is more than the screen size. Warning:
 some systems use ^Y as a special job control character.
 u or ^U
 Scroll backward N lines, default one half of the screen size.
 If N is specified, it becomes the new default for subsequent d
 and u commands.
 J Like j, but continues to scroll beyond the end of the file.
 K or Y Like k, but continues to scroll beyond the beginning of the
 file.
 ESC-SPACE
 Like SPACE, but scrolls a full screenful, even if it reaches the
 end of the file.
 ESC-b Like b, but scrolls a full screenful, even if it reaches the
 beginning of the file.
 ESC-j Scroll forward N file lines, default 1. A file line is a
 complete line in the file, terminated by a newline.
 ESC-k Scroll backwards N file lines, default 1.
 ESC-) or RIGHTARROW
 Scroll horizontally right N characters, default half the screen
 width (see the -# option). If a number N is specified, it
 becomes the default for future RIGHTARROW and LEFTARROW
 commands. While the text is scrolled, it acts as though the -S
 option (chop lines) were in effect.
 ESC-( or LEFTARROW
 Scroll horizontally left N characters, default half the screen
 width (see the -# option). If a number N is specified, it
 becomes the default for future RIGHTARROW and LEFTARROW
 commands.
 ESC-} or ^RIGHTARROW
 Scroll horizontally right to show the end of the longest
 displayed line.
 ESC-{ or ^LEFTARROW
 Scroll horizontally left back to the first column.
 r or ^R or ^L
 Repaint the screen.
 R Repaint the screen, discarding any buffered input. That is,
 reload the current file. Useful if the file is changing while
 it is being viewed.
 F Scroll forward, and keep trying to read when the end of file is
 reached. Normally this command would be used when already at
 the end of the file. It is a way to monitor the tail of a file
 which is growing while it is being viewed. (The behavior is
 similar to the "tail -f" command.) To stop waiting for more
 data, enter the interrupt character (usually ^C). On systems
 which support poll(2)  you can also use ^X or the character
 specified by the --intr option. If the input is a pipe and the
 --exit-follow-on-close option is in effect, less will
 automatically stop waiting for data when the input side of the
 pipe is closed.
 ESC-F Like F, but as soon as a line is found which matches the last
 search pattern, the terminal bell is rung and forward scrolling
 stops.
 g or < or ESC-<
 Go to line N in the file, default 1 (beginning of file).
 (Warning: this may be slow if N is large.)
 G or > or ESC->
 Go to line N in the file, default the end of the file.
 (Warning: this may be slow if N is large, or if N is not
 specified and standard input, rather than a file, is being
 read.)
 ESC-G Same as G, except if no number N is specified and the input is
 standard input, goes to the last line which is currently
 buffered.
 p or % Go to a position N percent into the file. N should be between 0
 and 100, and may contain a decimal point.
 P Go to the line containing byte offset N in the file.
 { If a left curly bracket appears in the top line displayed on the
 screen, the { command will go to the matching right curly
 bracket. The matching right curly bracket is positioned on the
 bottom line of the screen. If there is more than one left curly
 bracket on the top line, a number N may be used to specify the
 N-th bracket on the line.
 } If a right curly bracket appears in the bottom line displayed on
 the screen, the } command will go to the matching left curly
 bracket. The matching left curly bracket is positioned on the
 top line of the screen. If there is more than one right curly
 bracket on the bottom line, a number N may be used to specify
 the N-th bracket on the line.
 ( Like {, but applies to parentheses rather than curly brackets.
 ) Like }, but applies to parentheses rather than curly brackets.
 [ Like {, but applies to square brackets rather than curly
 brackets.
 ] Like }, but applies to square brackets rather than curly
 brackets.
 ESC-^F Followed by two characters, acts like {, but uses the two
 characters as open and close brackets, respectively. For
 example, "ESC ^F < >" could be used to go forward to the > which
 matches the < in the top displayed line.
 ESC-^B Followed by two characters, acts like }, but uses the two
 characters as open and close brackets, respectively. For
 example, "ESC ^B < >" could be used to go backward to the <
 which matches the > in the bottom displayed line.
 m Followed by any lowercase or uppercase letter, marks the first
 displayed line with that letter. If the status column is
 enabled via the -J option, the status column shows the marked
 line.
 M Acts like m, except the last displayed line is marked rather
 than the first displayed line.
 ' (Single quote.) Followed by any lowercase or uppercase letter,
 returns to the position which was previously marked with that
 letter. Followed by another single quote, returns to the
 position at which the last "large" movement command was
 executed. Followed by a ^ or ,ドル jumps to the beginning or end
 of the file respectively. Marks are preserved when a new file
 is examined, so the ' command can be used to switch between
 input files.
 ^X^X Same as single quote.
 ESC-m Followed by any lowercase or uppercase letter, clears the mark
 identified by that letter.
 /pattern
 Search forward in the file for the N-th line containing the
 pattern. N defaults to 1. The pattern is a regular expression,
 as recognized by the regular expression library supplied by your
 system. By default, searching is case-sensitive (uppercase and
 lowercase are considered different); the -i option can be used
 to change this. The search starts at the first line displayed
 (but see the -a and -j options, which change this).
 Certain characters are special if entered at the beginning of
 the pattern; they modify the type of search rather than become
 part of the pattern:
 ^N or !
 Search for lines which do NOT match the pattern.
 ^E or *
 Search multiple files. That is, if the search reaches
 the END of the current file without finding a match, the
 search continues in the next file in the command line
 list.
 ^F or @
 Begin the search at the first line of the FIRST file in
 the command line list, regardless of what is currently
 displayed on the screen or the settings of the -a or -j
 options.
 ^K Highlight any text which matches the pattern on the
 current screen, but don't move to the first match (KEEP
 current position).
 ^R Don't interpret regular expression metacharacters; that
 is, do a simple textual comparison.
 ^S Followed by a digit N between 1 and 5. Only text which
 has a non-empty match for the N-th parenthesized SUB-
 PATTERN will be considered to match the pattern. For
 example, searching for "(abc)|(def)" modified with ^S1
 would search for instances of "abc", but would highlight
 instances of both "abc" and "def". (Supported only if
 less is built with one of the regular expression
 libraries posix, pcre, or pcre2.) Multiple ^S modifiers
 can be specified, to match more than one sub-pattern.
 ^W WRAP around the current file. That is, if the search
 reaches the end of the current file without finding a
 match, the search continues from the first line of the
 current file up to the line where it started. If the ^W
 modifier is set, the ^E modifier is ignored.
 ^L The next character is taken literally; that is, it
 becomes part of the pattern even if it is one of the
 above search modifier characters.
 ?pattern
 Search backward in the file for the N-th line containing the
 pattern. The search starts at the last line displayed (but see
 the -a and -j options, which change this).
 Certain characters are special as in the / command:
 ^N or !
 Search for lines which do NOT match the pattern.
 ^E or *
 Search multiple files. That is, if the search reaches
 the beginning of the current file without finding a
 match, the search continues in the previous file in the
 command line list.
 ^F or @
 Begin the search at the last line of the last file in the
 command line list, regardless of what is currently
 displayed on the screen or the settings of the -a or -j
 options.
 ^K As in forward searches.
 ^R As in forward searches.
 ^S As in forward searches.
 ^W WRAP around the current file. That is, if the search
 reaches the beginning of the current file without finding
 a match, the search continues from the last line of the
 current file up to the line where it started.
 ^L As in forward searches.
 ESC-/pattern
 Same as "/*".
 ESC-?pattern
 Same as "?*".
 n Repeat previous search, for N-th line containing the last
 pattern. If the previous search was modified by ^N, the search
 is made for the N-th line NOT containing the pattern. If the
 previous search was modified by ^E, the search continues in the
 next (or previous) file if not satisfied in the current file.
 If the previous search was modified by ^R, the search is done
 without using regular expressions. If the previous search was
 modified by ^W, the search wraps at the end (or beginning) of
 the file. There is no effect if the previous search was
 modified by ^F or ^K.
 N Repeat previous search, but in the reverse direction.
 ESC-n Repeat previous search, but crossing file boundaries. The
 effect is as if the previous search were modified by *.
 ESC-N Repeat previous search, but in the reverse direction and
 crossing file boundaries.
 ESC-u Undo search highlighting. Turn off highlighting of strings
 matching the current search pattern. If highlighting is already
 off because of a previous ESC-u command, turn highlighting back
 on. Any search command will also turn highlighting back on.
 (Highlighting can also be disabled by toggling the -G option; in
 that case search commands do not turn highlighting back on.)
 ESC-U Like ESC-u but also clears the saved search pattern. If the
 status column is enabled via the -J option, this clears all
 search matches marked in the status column.
 &pattern
 Display only lines which match the pattern; lines which do not
 match the pattern are not displayed. If pattern is empty (if
 you type & immediately followed by ENTER), any filtering is
 turned off, and all lines are displayed. While filtering is in
 effect, an ampersand is displayed at the beginning of the
 prompt, as a reminder that some lines in the file may be hidden.
 Multiple & commands may be entered, in which case only lines
 which match all of the patterns will be displayed.
 Certain characters are special as in the / command:
 ^N or !
 Display only lines which do NOT match the pattern.
 ^R Don't interpret regular expression metacharacters; that
 is, do a simple textual comparison.
 :e [filename]
 Examine a new file. If the filename is missing, the "current"
 file (see the :n and :p commands below) from the list of files
 in the command line is re-examined. A percent sign (%) in the
 filename is replaced by the name of the current file. A pound
 sign (#) is replaced by the name of the previously examined
 file. However, two consecutive percent signs are simply
 replaced with a single percent sign. This allows you to enter a
 filename that contains a percent sign in the name. Similarly,
 two consecutive pound signs are replaced with a single pound
 sign. The filename is inserted into the command line list of
 files so that it can be seen by subsequent :n and :p commands.
 If the filename consists of several files, they are all inserted
 into the list of files and the first one is examined. If the
 filename contains one or more spaces, the entire filename should
 be enclosed in double quotes (also see the -" option).
 ^X^V or E
 Same as :e. Warning: some systems use ^V as a special
 literalization character. On such systems, you may not be able
 to use ^V.
 :n Examine the next file (from the list of files given in the
 command line). If a number N is specified, the N-th next file
 is examined.
 :p Examine the previous file in the command line list. If a number
 N is specified, the N-th previous file is examined.
 :x Examine the first file in the command line list. If a number N
 is specified, the N-th file in the list is examined.
 :d Remove the current file from the list of files.
 t Go to the next tag, if there were more than one matches for the
 current tag. See the -t option for more details about tags.
 T Go to the previous tag, if there were more than one matches for
 the current tag.
 ^O^N or ^On
 Search forward in the file for the N-th next OSC 8 hyperlink.
 ^O^P or ^Op
 Search backward in the file for the N-th previous OSC 8
 hyperlink.
 ^O^L or ^Ol
 Jump to the currently selected OSC 8 hyperlink.
 = or ^G or :f
 Prints some information about the file being viewed, including
 its name and the line number and byte offset of the bottom line
 being displayed. If possible, it also prints the length of the
 file, the number of lines in the file and the percent of the
 file above the last displayed line.
 - Followed by one of the command line option letters (see OPTIONS
 below), this will change the setting of that option and print a
 message describing the new setting. If a ^P (CONTROL-P) is
 entered immediately after the dash, the setting of the option is
 changed but no message is printed. If the option letter has a
 numeric value (such as -b or -h), or a string value (such as -P
 or -t), a new value may be entered after the option letter. If
 no new value is entered, a message describing the current
 setting is printed and nothing is changed.
 -- Like the - command, but takes a long option name (see OPTIONS
 below) rather than a single option letter. Press ENTER or
 RETURN after typing the option name to change it. You can enter
 just the beginning of an option name, then press TAB to find all
 option names which begin with that string. A ^P immediately
 after the second dash suppresses printing of a message
 describing the new setting, as in the - command.
 -+ Followed by one of the command line option letters this will
 reset the option to its default setting and print a message
 describing the new setting. (The "-+X" command does the same
 thing as "-+X" on the command line.) This does not work for
 string-valued options.
 --+ Like the -+ command, but takes a long option name rather than a
 single option letter.
 -! Followed by one of the command line option letters, this will
 reset the option to the "opposite" of its default setting and
 print a message describing the new setting. This does not work
 for numeric or string-valued options.
 --! Like the -! command, but takes a long option name rather than a
 single option letter.
 _ (Underscore.) Followed by one of the command line option
 letters, this will print a message describing the current
 setting of that option. The setting of the option is not
 changed.
 __ (Double underscore.) Like the _ (underscore) command, but takes
 a long option name rather than a single option letter. You must
 press ENTER or RETURN after typing the option name.
 +cmd Causes the specified cmd to be executed each time a new file is
 examined. For example, +G causes less to initially display each
 file starting at the end rather than the beginning.
 V Prints the version number of less being run.
 q or Q or :q or :Q or ZZ
 Exits less.
 The following seven commands may or may not be valid, depending on your
 particular installation.
 v Invokes an editor to edit the current file being viewed. The
 editor is taken from the environment variable VISUAL if defined,
 or EDITOR if VISUAL is not defined, or defaults to "vi" if
 neither VISUAL nor EDITOR is defined. See also the discussion
 of LESSEDIT under the section on PROMPTS below.
 ! shell-command
 Invokes a shell to run the shell-command given. A percent sign
 (%) in the command is replaced by the name of the current file.
 A pound sign (#) is replaced by the name of the previously
 examined file. "!!" repeats the last shell command. "!" with
 no shell command invokes an interactive shell. If a ^P
 (CONTROL-P) is entered immediately after the !, no "done"
 message is printed after the shell command is executed. On Unix
 systems, the shell is taken from the environment variable SHELL,
 or defaults to "sh". On MS-DOS, Windows, and OS/2 systems, the
 shell is the normal command processor.
 # shell-command
 Similar to the "!" command, except that the command is expanded
 in the same way as prompt strings. For example, the name of the
 current file would be given as "%f".
 | <m> shell-command
 <m> represents any mark letter. Pipes a section of the input
 file to the given shell command. The section of the file to be
 piped is between the position marked by the letter and the
 current screen. The entire current screen is included,
 regardless of whether the marked position is before or after the
 current screen. <m> may also be ^ or $ to indicate beginning or
 end of file respectively. If <m> is . or newline, the current
 screen is piped. If a ^P (CONTROL-P) is entered immediately
 after the mark letter, no "done" message is printed after the
 shell command is executed.
 s filename
 Save the input to a file. This works only if the input is a
 pipe, not an ordinary file.
 ^O^O
 Run a shell command to open the URI in the current OSC 8
 hyperlink, selected by a previous ^O^N or ^O^P command. To find
 the shell command, the environment variable named
 "LESS_OSC8_xxx" is read, where "xxx" is the scheme from the URI
 (the part before the first colon), or is empty if there is no
 colon in the URI. The value of the environment variable is then
 expanded in the same way as prompt strings (in particular, any
 instance of "%o" is replaced with the URI) to produce an OSC 8
 "handler" shell command. The standard output from the handler
 is an "opener" shell command which is then executed to open the
 URI.
 There are two special cases:
 1. If the URI begins with "#", the remainder of the
 URI is taken to be the value of the id parameter
 in another OSC 8 link in the same file, and ^O^O
 will simply jump to that link.
 2. If the opener begins with the characters ":e"
 followed by whitespace and a filename, then
 instead of running the opener as a shell command,
 the specified filename is opened in the current
 instance of less.
 In a simple case where the opener accepts the complete URI as a
 command line parameter, the handler may be as simple as
 echo mybrowser '%o'
 In other cases, the URI may need to be modified, so the handler
 may have to do some manipulation of the %o value.
 If the LESS_OSC8_xxx variable is not set, the variable
 LESS_OSC8_ANY is tried. If neither LESS_OSC8_xxx nor
 LESS_OSC8_ANY is set, links using the "xxx" scheme cannot be
 opened. However, there are default handlers for the schemes
 "man" (used when LESS_OSC8_man is not set) and "file" (used when
 LESS_OSC8_file is not set), which should work on systems which
 provide the sed(1)  command and a shell with syntax compatible
 with the Bourne shell sh(1) . If you use LESS_OSC8_ANY to
 override LESS_OSC8_file, you must set LESS_OSC8_file to "-" to
 indicate that the default value should not be used, and likewise
 for LESS_OSC8_man.
 The URI passed to an OSC8 handler via %o is guaranteed not to
 contain any single quote or double quote characters, but it may
 contain any other shell metacharacters such as semicolons,
 dollar signs, ampersands, etc. The handler should take care to
 appropriately quote parameters in the opener command, to prevent
 execution of unintended shell commands in the case of opening a
 URI which contains shell metacharacters. Also, since the
 handler command is expanded like a command prompt, any
 metacharacters interpreted by prompt expansion (such as percent,
 dot, colon, backslash, etc.) must be escaped with a backslash
 (see the PROMPTS section for details).
 ^X When the "Waiting for data" message is displayed, such as while
 in the F command, pressing ^X will stop less from waiting and
 return to a prompt. This may cause less to think that the file
 ends at the current position, so it may be necessary to use the
 R or F command to see more data. The --intr option can be used
 to specify a different character to use instead of ^X. This
 command works only on systems that support the poll(2)  function.
 On systems without poll(2) , the interrupt character (usually ^C)
 can be used instead.

OPTIONS

 Command line options are described below. Most options may be changed
 while less is running, via the "-" command.
 Some options may be given in one of two forms: either a dash followed
 by a single letter, or two dashes followed by a long option name. A
 long option name may be abbreviated as long as the abbreviation is
 unambiguous. For example, --mouse may be abbreviated --mou, but not
 --mo, since both --mouse and --modelines begin with --mo. Some long
 option names are in uppercase, such as --QUIT-AT-EOF, as distinct from
 --quit-at-eof. Such option names need only have their first letter
 capitalized; the remainder of the name may be in either case. For
 example, --Quit-at-eof is equivalent to --QUIT-AT-EOF.
 Options are also taken from the environment variable "LESS". For
 example, to avoid typing "less -options ..." each time less is invoked,
 you might tell csh:
 setenv LESS "-options"
 or if you use sh:
 LESS="-options"; export LESS
 On MS-DOS and Windows, you don't need the quotes, but you should be
 careful that any percent signs in the options string are not
 interpreted as an environment variable expansion.
 The environment variable is parsed before the command line, so command
 line options override the LESS environment variable. If an option
 appears in the LESS variable, it can be reset to its default value on
 the command line by beginning the command line option with "-+".
 Some options like -k or -D require a string to follow the option
 letter. The string for that option is considered to end when a dollar
 sign ($) is found. For example, you can set two -D options like this:
 LESS="Dnwb$Dsbw"
 If the --use-backslash option appears earlier in the options, then a
 dollar sign or backslash may be included literally in an option string
 by preceding it with a backslash. If the --use-backslash option is not
 in effect, then backslashes are not treated specially, and there is no
 way to include a dollar sign in the option string.
 -? or --help
 This option displays a summary of the commands accepted by less
 (the same as the h command). (Depending on how your shell
 interprets the question mark, it may be necessary to quote the
 question mark, thus: "-\?".)
 -a or --search-skip-screen
 By default, forward searches start at the top of the displayed
 screen and backwards searches start at the bottom of the
 displayed screen (except for repeated searches invoked by the n
 or N commands, which start after or before the "target" line
 respectively; see the -j option for more about the target line).
 The -a option causes forward searches to instead start at the
 bottom of the screen and backward searches to start at the top
 of the screen, thus skipping all lines displayed on the screen.
 -A or --SEARCH-SKIP-SCREEN
 Causes all forward searches (not just non-repeated searches) to
 start just after the target line, and all backward searches to
 start just before the target line. Thus, forward searches will
 skip part of the displayed screen (from the first line up to and
 including the target line). Similarly backwards searches will
 skip the displayed screen from the last line up to and including
 the target line. This was the default behavior in less versions
 prior to 441.
 -bn or --buffers=n
 Specifies the amount of buffer space less will use for each
 file, in units of kilobytes (1024 bytes). By default 64 KB of
 buffer space is used for each file (unless the file is a pipe;
 see the -B option). The -b option specifies instead that n
 kilobytes of buffer space should be used for each file. If n is
 -1, buffer space is unlimited; that is, the entire file can be
 read into memory.
 -B or --auto-buffers
 By default, when data is read from a pipe, buffers are allocated
 automatically as needed. If a large amount of data is read from
 the pipe, this can cause a large amount of memory to be
 allocated. The -B option disables this automatic allocation of
 buffers for pipes, so that only 64 KB (or the amount of space
 specified by the -b option) is used for the pipe. Warning: use
 of -B can result in erroneous display, since only the most
 recently viewed part of the piped data is kept in memory; any
 earlier data is lost. Lost characters are displayed as question
 marks.
 -c or --clear-screen
 Causes full screen repaints to be painted from the top line
 down. By default, full screen repaints are done by scrolling
 from the bottom of the screen.
 -C or --CLEAR-SCREEN
 Same as -c, for compatibility with older versions of less.
 -d or --dumb
 The -d option suppresses the error message normally displayed if
 the terminal is dumb; that is, lacks some important capability,
 such as the ability to clear the screen or scroll backward. The
 -d option does not otherwise change the behavior of less on a
 dumb terminal.
 -Dxcolor or --color=xcolor
 Changes the color of different parts of the displayed text. x
 is a single character which selects the type of text whose color
 is being set:
 B Binary characters.
 C Control characters.
 E Errors and informational messages.
 H Header lines and columns, set via the --header option.
 M Mark letters in the status column.
 N Line numbers enabled via the -N option.
 P Prompts.
 R The rscroll character.
 S Search results.
 W The highlight enabled via the -w option.
 1-5 The text in a search result which matches the first
 through fifth parenthesized sub-pattern. Sub-pattern
 coloring works only if less is built with one of the
 regular expression libraries posix, pcre, or pcre2.
 d Bold text.
 k Blinking text.
 s Standout text.
 u Underlined text.
 The uppercase letters and digits can be used only when the
 --use-color option is enabled. When text color is specified by
 both an uppercase letter and a lowercase letter, the uppercase
 letter takes precedence. For example, error messages are
 normally displayed as standout text. So if both "s" and "E" are
 given a color, the "E" color applies to error messages, and the
 "s" color applies to other standout text. The lowercase letters
 refer to bold and underline text formed by overstriking with
 backspaces (see the -U option) and to non-content text (such as
 line numbers and prompts), but not to text formatted using ANSI
 escape sequences with the -R option (but see the note below for
 different behavior on Windows and MS-DOS).
 A lowercase letter may be followed by a + to indicate that the
 normal format change and the specified color should both be
 used. For example, -Dug displays underlined text as green
 without underlining; the green color has replaced the usual
 underline formatting. But -Du+g displays underlined text as
 both green and in underlined format.
 color is either a 4-bit color string or an 8-bit color string:
 A 4-bit color string is one or two characters, where the first
 character specifies the foreground color and the second
 specifies the background color as follows:
 b Blue
 c Cyan
 g Green
 k Black
 m Magenta
 r Red
 w White
 y Yellow
 The corresponding uppercase letter denotes a brighter shade of
 the color. For example, -DNGk displays line numbers as bright
 green text on a black background, and -DEbR displays error
 messages as blue text on a bright red background. If either
 character is a "-" or is omitted, the corresponding color is set
 to that of normal text.
 An 8-bit color string is one or two decimal integers separated
 by a dot, where the first integer specifies the foreground color
 and the second specifies the background color. Each integer is
 a value between 0 and 255 inclusive which selects a "CSI 38;5"
 color value (see
 <https://en.wikipedia.org/wiki/ANSI_escape_code#SGR >). If
 either integer is a "-" or is omitted, the corresponding color
 is set to that of normal text.
 A 4-bit or 8-bit color string may be followed by one or more of
 the following characters to set text attributes in addition to
 the color.
 s or ~ Standout (reverse video)
 u or _ Underline
 d or * Bold
 l or & Blinking
 On MS-DOS and Windows, the --color option behaves differently
 from what is described above in these ways:
 o The bold (d and *) and blinking (l and &) text attributes
 at the end of a color string are not supported.
 o Lowercase color selector letters refer to text formatted
 by ANSI escape sequences with -R, in addition to
 overstruck and non-content text (but see -Da).
 o For historical reasons, when a lowercase color selector
 letter is followed by a numeric color value, the number
 is not interpreted as an "CSI 38;5" color value as
 described above, but instead as a 4-bit
 CHAR_INFO.Attributes value, between 0 and 15 inclusive
 (see
 <https://learn.microsoft.com/en-us/windows/console/char-info-str >).
 To avoid confusion, it is recommended that the equivalent
 letters rather than numbers be used after a lowercase
 color selector on MS-DOS/Windows.
 o Numeric color values ("CSI 38;5" color) following an
 uppercase color selector letter are not supported on
 systems earlier than Windows 10.
 o Only a limited set of ANSI escape sequences to set color
 in the content work correctly. 4-bit color sequences
 work, but "CSI 38;5" color sequences do not.
 o The -Da option makes the behavior of --color more similar
 to its behavior on non-MS-DOS/Windows systems by (1)
 making lowercase color selector letters not affect text
 formatted with ANSI escape sequences, and (2) allowing
 "CSI 38;5" color sequences in the content work by passing
 them to the terminal (only on Windows 10 and later; on
 earlier Windows systems, such sequences do not work
 regardless of the setting of -Da).
 -e or --quit-at-eof
 Causes less to automatically exit the second time it reaches
 end-of-file. By default, the only way to exit less is via the
 "q" command.
 -E or --QUIT-AT-EOF
 Causes less to automatically exit the first time it reaches end-
 of-file.
 -f or --force
 Forces non-regular files to be opened. (A non-regular file is a
 directory or a device special file.) Also suppresses the
 warning message when a binary file is opened. By default, less
 will refuse to open non-regular files. Note that some operating
 systems will not allow directories to be read, even if -f is
 set.
 -F or --quit-if-one-screen
 Causes less to automatically exit if the entire file can be
 displayed on the first screen. Also see the description of the
 LESS_SHELL_LINES environment variable below.
 -g or --hilite-search
 Normally, less will highlight ALL strings which match the last
 search command. The -g option changes this behavior to
 highlight only the particular string which was found by the last
 search command. This can cause less to run somewhat faster than
 the default.
 -G or --HILITE-SEARCH
 The -G option suppresses all highlighting of strings found by
 search commands.
 -hn or --max-back-scroll=n
 Specifies a maximum number of lines to scroll backward. If it
 is necessary to scroll backward more than n lines, the screen is
 repainted in a forward direction instead. (If the terminal does
 not have the ability to scroll backward, -h0 is implied.)
 -i or --ignore-case
 Causes searches to ignore case; that is, uppercase and lowercase
 are considered identical. This option is ignored if any
 uppercase letters appear in the search pattern; in other words,
 if a pattern contains uppercase letters, then that search does
 not ignore case.
 -I or --IGNORE-CASE
 Like -i, but searches ignore case even if the pattern contains
 uppercase letters.
 -jn or --jump-target=n
 Specifies a line on the screen where the "target" line is to be
 positioned. The target line is the line specified by any
 command to search for a pattern, jump to a line number, jump to
 a file percentage or jump to a tag. The screen line may be
 specified by a number: the top line on the screen is 1, the next
 is 2, and so on. The number may be negative to specify a line
 relative to the bottom of the screen: the bottom line on the
 screen is -1, the second to the bottom is -2, and so on.
 Alternately, the screen line may be specified as a fraction of
 the height of the screen, starting with a decimal point: .5 is
 in the middle of the screen, .3 is three tenths down from the
 first line, and so on. If the line is specified as a fraction,
 the actual line number is recalculated if the terminal window is
 resized. If the --header option is used and the target line
 specified by -j would be obscured by the header, the target line
 is moved to the first line after the header.
 If any form of the -j option is used, repeated forward searches
 (invoked with "n" or "N") begin at the line immediately after
 the target line, and repeated backward searches begin at the
 target line, unless changed by -a or -A. For example, if "-j4"
 is used, the target line is the fourth line on the screen, so
 forward searches begin at the fifth line on the screen. However
 nonrepeated searches (invoked with "/" or "?") always begin at
 the start or end of the current screen respectively.
 -J or --status-column
 Displays a status column at the left edge of the screen. The
 character displayed in the status column may be one of:
 > The line is chopped with the -S option, and the text that
 is chopped off beyond the right edge of the screen
 contains a match for the current search.
 < The line is horizontally shifted, and the text that is
 shifted beyond the left side of the screen contains a
 match for the current search.
 = The line is both chopped and shifted, and there are
 matches beyond both sides of the screen.
 * There are matches in the visible part of the line but
 none to the right or left of it.
 a-z, A-Z
 The line has been marked with the corresponding letter
 via the m or M command.
 -kfilename or --lesskey-file=filename
 Causes less to open and interpret the named file as a lesskey(1) 
 binary file. Multiple -k options may be specified. If the
 LESSKEY or LESSKEY_SYSTEM environment variable is set, or if a
 lesskey file is found in a standard place (see KEY BINDINGS), it
 is also used as a lesskey file. Note the warning under
 "--lesskey-content" below.
 --lesskey-src=filename
 Causes less to open and interpret the named file as a lesskey(1) 
 source file. If the LESSKEYIN or LESSKEYIN_SYSTEM environment
 variable is set, or if a lesskey source file is found in a
 standard place (see KEY BINDINGS), it is also used as a lesskey
 source file. Prior to version 582, the lesskey program needed
 to be run to convert a lesskey source file to a lesskey binary
 file for less to use. Newer versions of less read the lesskey
 source file directly and ignore the binary file if the source
 file exists. Note the warning under "--lesskey-content" below.
 --lesskey-content=text
 Causes less to interpret the specified text as the contents of a
 lesskey(1)  source file. In the text, lesskey lines may be
 separated by either newlines as usual, or by semicolons. A
 literal semicolon may be represented by a backslash followed by
 a semicolon.
 Warning: certain environment variables such as LESS, LESSSECURE,
 LESSCHARSET and others, which are used early in startup, cannot
 be set in a file specified by a command line option (--lesskey,
 --lesskey-src or --lesskey-content). When using a lesskey file
 to set environment variables, it is safer to use the default
 lesskey file, or to specify the file using the LESSKEYIN or
 LESSKEY_CONTENT environment variables rather than using a
 command line option.
 -K or --quit-on-intr
 Causes less to exit immediately (with status 2) when an
 interrupt character (usually ^C) is typed. Normally, an
 interrupt character causes less to stop whatever it is doing and
 return to its command prompt. Note that use of this option
 makes it impossible to return to the command prompt from the "F"
 command.
 -L or --no-lessopen
 Ignore the LESSOPEN environment variable (see the INPUT
 PREPROCESSOR section below). This option can be set from within
 less, but it will apply only to files opened subsequently, not
 to the file which is currently open.
 -m or --long-prompt
 Causes less to prompt verbosely (like more(1) ), with the percent
 into the file. By default, less prompts with a colon.
 -M or --LONG-PROMPT
 Causes less to prompt even more verbosely than more(1) .
 -n or --line-numbers
 Suppresses line numbers. The default (to use line numbers) may
 cause less to run more slowly in some cases, especially with a
 very large input file. Using line numbers means: the line
 number will be displayed in the verbose prompt and in the =
 command, and the v command will pass the current line number to
 the editor (see also the discussion of LESSEDIT in PROMPTS
 below).
 -N or --LINE-NUMBERS
 Causes a line number to be displayed at the beginning of each
 line in the display.
 -ofilename or --log-file=filename
 Causes less to copy its input to the named file as it is being
 viewed. This applies only when the input file is a pipe, not an
 ordinary file. If the file already exists, less will ask for
 confirmation before overwriting it.
 -Ofilename or --LOG-FILE=filename
 The -O option is like -o, but it will overwrite an existing file
 without asking for confirmation.
 If no log file has been specified, the -o and -O options can be
 used from within less to specify a log file. Without a file
 name, they will simply report the name of the log file. The "s"
 command is equivalent to specifying -o from within less.
 -ppattern or --pattern=pattern
 The -p option on the command line is equivalent to specifying
 +/pattern; that is, it tells less to start at the first
 occurrence of pattern in the file.
 -Pprompt or --prompt=prompt
 Provides a way to tailor the three prompt styles to your own
 preference. This option would normally be put in the LESS
 environment variable, rather than being typed in with each less
 command. Such an option must either be the last option in the
 LESS variable, or be terminated by a dollar sign.
 -Ps followed by a string changes the default (short) prompt to
 that string.
 -Pm changes the medium (-m) prompt.
 -PM changes the long (-M) prompt.
 -Ph changes the prompt for the help screen.
 -P= changes the message printed by the = command.
 -Pw changes the message printed while waiting for data (in the
 "F" command).
 All prompt strings consist of a sequence of letters and special
 escape sequences. See the section on PROMPTS for more details.
 -q or --quiet or --silent
 Causes moderately "quiet" operation: the terminal bell is not
 rung if an attempt is made to scroll past the end of the file or
 before the beginning of the file. If the terminal has a "visual
 bell", it is used instead. The bell will be rung on certain
 other errors, such as typing an invalid character. The default
 is to ring the terminal bell in all such cases.
 -Q or --QUIET or --SILENT
 Causes totally "quiet" operation: the terminal bell is never
 rung. If the terminal has a "visual bell", it is used in all
 cases where the terminal bell would have been rung.
 -r or --raw-control-chars
 Causes "raw" control characters to be displayed. The default is
 to display control characters using the caret notation; for
 example, a control-A (octal 001) is displayed as "^A" (with some
 exceptions as described under the -U option). Warning: when the
 -r option is used, less cannot keep track of the actual
 appearance of the screen (since this depends on how the screen
 responds to each type of control character). Thus, various
 display problems may result, such as long lines being split in
 the wrong place.
 USE OF THE -r OPTION IS DANGEROUS AND IS NOT RECOMMENDED.
 The -r option can be set on the command line or via the -
 command, but to avoid unintentional use, it cannot be set in a
 LESS environment variable. If -r appears in a LESS environment
 variable, it is treated as if it were -R.
 -R or --RAW-CONTROL-CHARS
 Like -r, but only a limited set of escape sequences are output
 in "raw" form. Unlike -r, the screen appearance is maintained
 correctly. The sequences which are output raw are:
 1. ANSI SGR ("color") sequences
 2. OSC 8 hyperlinks
 3. Other OSC sequences, if the OSC type number is listed in the
 LESSANSIOSCALLOW environment variable
 4. OSC sequences starting with a non-standard introductory
 character (that is, something other than "]"), if the character
 is listed in the LESSANSIOSCCHARS environment variable followed
 by an asterisk
 ANSI color escape sequences are sequences of the form:
 ESC [ ... m
 where the "..." is zero or more color specification characters.
 Color escape sequences are only supported when the color is
 changed within one line, not across lines. In other words, the
 beginning of each line is assumed to be normal (non-colored),
 regardless of any escape sequences in previous lines.
 You can make less think that characters other than "m" can end
 ANSI color escape sequences by setting the environment variable
 LESSANSIENDCHARS to the list of characters which can end a color
 escape sequence. And you can make less think that characters
 other than the standard ones may appear between the ESC and the
 m by setting the environment variable LESSANSIMIDCHARS to the
 list of characters which can appear.
 OSC sequences are of the form:
 ESC ] N ; ... 7円
 where the OSC type number N is a decimal integer. The
 terminating sequence may be either a BEL character (7円) as
 above, or the two-character sequence "ESC \".
 -s or --squeeze-blank-lines
 Causes consecutive blank lines to be squeezed into a single
 blank line. This is useful when viewing nroff(1)  output.
 -S or --chop-long-lines
 Causes lines longer than the screen width to be chopped
 (truncated) rather than wrapped. That is, the portion of a long
 line that does not fit in the screen width is not displayed
 until you press RIGHT-ARROW. The default is to wrap long lines;
 that is, display the remainder on the next line. See also the
 --wordwrap option. While the --header option is active, the -S
 option is ignored, and lines longer than the screen width are
 truncated.
 -ttag or --tag=tag
 The -t option, followed immediately by a TAG, will edit the file
 containing that tag. For this to work, tag information must be
 available; for example, there may be a file in the current
 directory called "tags", which was previously built by ctags(1) 
 or an equivalent command. If the environment variable
 LESSGLOBALTAGS is set, it is taken to be the name of a command
 compatible with global(1), and that command is executed to find
 the tag. (See
 <http://www.gnu.org/software/global/global.html >). The -t
 option may also be specified from within less (using the -
 command) as a way of examining a new file. The command ":t" is
 equivalent to specifying -t from within less.
 -Ttagsfile or --tag-file=tagsfile
 Specifies a tags file to be used instead of "tags".
 -u or --underline-special
 Causes backspaces and carriage returns to be treated as
 printable characters; that is, they are sent to the terminal
 when they appear in the input.
 -U or --UNDERLINE-SPECIAL
 Causes backspaces, tabs, carriage returns and "formatting
 characters" (as defined by Unicode) to be treated as control
 characters; that is, they are handled as specified by the -r
 option.
 By default, if neither -u nor -U is given, backspaces which
 appear adjacent to an underscore character are treated
 specially: the underlined text is displayed using the terminal's
 hardware underlining capability. Also, backspaces which appear
 between two identical characters are treated specially: the
 overstruck text is printed using the terminal's hardware
 boldface capability. Other backspaces are deleted, along with
 the preceding character. Carriage returns immediately followed
 by a newline are deleted. Other carriage returns are handled as
 specified by the -r option. Unicode formatting characters, such
 as the Byte Order Mark, are sent to the terminal. Text which is
 overstruck or underlined can be searched for if neither -u nor
 -U is in effect.
 See also the --proc-backspace, --proc-tab, and --proc-return
 options.
 -V or --version
 Displays the version number of less.
 -w or --hilite-unread
 Temporarily highlights the first "new" line after a forward
 movement of a full page. The first "new" line is the line
 immediately following the line previously at the bottom of the
 screen. Also highlights the target line after a g or p command.
 The highlight is removed at the next command which causes
 movement. If the --status-line option is in effect, the entire
 line (the width of the screen) is highlighted. Otherwise, only
 the text in the line is highlighted, unless the -J option is in
 effect, in which case only the status column is highlighted.
 -W or --HILITE-UNREAD
 Like -w, but temporarily highlights the first new line after any
 forward movement command larger than one line.
 -xn,... or --tabs=n,...
 Sets tab stops. If only one n is specified, tab stops are set
 at multiples of n. If multiple values separated by commas are
 specified, tab stops are set at those positions, and then
 continue with the same spacing as the last two. For example,
 "-x9,17" will set tabs at positions 9, 17, 25, 33, etc. The
 default for n is 8.
 -X or --no-init
 Disables sending the termcap initialization and deinitialization
 strings to the terminal. This is sometimes desirable if the
 deinitialization string does something unnecessary, like
 clearing the screen.
 -yn or --max-forw-scroll=n
 Specifies a maximum number of lines to scroll forward. If it is
 necessary to scroll forward more than n lines, the screen is
 repainted instead. The -c or -C option may be used to repaint
 from the top of the screen if desired. By default, any forward
 movement causes scrolling.
 -zn or --window=n or -n
 Changes the default scrolling window size to n lines. The
 default is one screenful. The z and w commands can also be used
 to change the window size. The "z" may be omitted for
 compatibility with some versions of more(1) . If the number n is
 negative, it indicates n lines less than the current screen
 size. For example, if the screen is 24 lines, -z-4 sets the
 scrolling window to 20 lines. If the screen is resized to 40
 lines, the scrolling window automatically changes to 36 lines.
 -"cc or --quotes=cc
 Changes the filename quoting character. This may be necessary
 if you are trying to name a file which contains both spaces and
 quote characters. Followed by a single character, this changes
 the quote character to that character. Filenames containing a
 space should then be surrounded by that character rather than by
 double quotes. Followed by two characters, changes the open
 quote to the first character, and the close quote to the second
 character. Filenames containing a space should then be preceded
 by the open quote character and followed by the close quote
 character. Note that even after the quote characters are
 changed, this option remains -" (a dash followed by a double
 quote).
 -~ or --tilde
 Normally lines after end of file are displayed as a single tilde
 (~). This option causes lines after end of file to be displayed
 as blank lines.
 -# or --shift
 Specifies the default number of positions to scroll horizontally
 in the RIGHTARROW and LEFTARROW commands. If the number
 specified is zero, it sets the default number of positions to
 one half of the screen width. Alternately, the number may be
 specified as a fraction of the width of the screen, starting
 with a decimal point: .5 is half of the screen width, .3 is
 three tenths of the screen width, and so on. If the number is
 specified as a fraction, the actual number of scroll positions
 is recalculated if the terminal window is resized.
 --exit-follow-on-close
 When using the "F" command on a pipe, less will automatically
 stop waiting for more data when the input side of the pipe is
 closed.
 --file-size
 If --file-size is specified, less will determine the size of the
 file immediately after opening the file. Then the "=" command
 will display the number of lines in the file. Normally this is
 not done, because it can be slow if the input file is non-
 seekable (such as a pipe) and is large.
 --follow-name
 Normally, if the input file is renamed while an F command is
 executing, less will continue to display the contents of the
 original file despite its name change. If --follow-name is
 specified, during an F command less will periodically attempt to
 reopen the file by name. If the reopen succeeds and the file is
 a different file from the original (which means that a new file
 has been created with the same name as the original (now
 renamed) file), less will display the contents of that new file.
 --form-feed
 When scrolling forward or backward in the file, stop if a line
 beginning with a form feed character (^L) is reached. This can
 be useful when viewing a file which uses form feeds between
 pages.
 --header=L,C,N
 Sets the number of header lines and columns displayed on the
 screen. The number of header lines is set to L. If L is 0,
 header lines are disabled. If L is empty or missing, the number
 of header lines is unchanged. The number of header columns is
 set to C. If C is 0, header columns are disabled. If C is
 empty or missing, the number of header columns is unchanged.
 The first header line is set to line number N in the file. If N
 is empty or missing, it is taken to be the number of the line
 currently displayed in the first line of the screen (if the
 --header command has been issued from within less), or 1 (if the
 --header option has been given on the command line). The
 special form "--header=-" disables header lines and header
 columns, and is equivalent to "--header=0,0".
 When L is nonzero, the first L lines at the top of the screen
 are replaced with the L lines of the file beginning at line N,
 regardless of what part of the file is being viewed. When
 header lines are displayed, any file contents before the header
 line cannot be viewed. When C is nonzero, the first C
 characters displayed at the beginning of each line are replaced
 with the first C characters of the line, even if the rest of the
 line is scrolled horizontally.
 While the --header option is active, lines longer than the
 screen width are truncated, and the -S option is ignored.
 --incsearch
 Subsequent search commands will be "incremental"; that is, less
 will advance to the next line containing the search pattern as
 each character of the pattern is typed in.
 --intr=c
 Use the character c instead of ^X to interrupt a read when the
 "Waiting for data" message is displayed. c must be an ASCII
 character; that is, one with a value between 1 and 127
 inclusive. A caret followed by a single character can be used
 to specify a control character.
 --line-num-width=n
 Sets the minimum width of the line number field when the -N
 option is in effect to n characters. The default is 7.
 --match-shift=n
 When -S is in effect, if a search match is not visible because
 it is shifted to the left or right of the currently visible
 screen, the text will horizontally shift to ensure that the
 search match is visible. This option selects the column in
 which the first character of the search match will be placed
 after the shift. In other words, there will be n characters
 visible to the left of the search match.
 Alternately, the number may be specified as a fraction of the
 width of the screen, starting with a decimal point: .5 is half
 of the screen width, .3 is three tenths of the screen width, and
 so on. If the number is specified as a fraction, the actual
 number of scroll positions is recalculated if the terminal
 window is resized.
 --modelines=n
 Before displaying a file, less will read the first n lines to
 try to find a vim-compatible modeline. If n is zero, less does
 not try to find modelines. By using a modeline, the file itself
 can specify the tab stops that should be used when viewing it.
 A modeline contains, anywhere in the line, a program name ("vi",
 "vim", "ex", or "less"), followed by a colon, possibly followed
 by the word "set", and finally followed by zero or more option
 settings. If the word "set" is used, option settings are
 separated by spaces, and end at the first colon. If the word
 "set" is not used, option settings may be separated by either
 spaces or colons. The word "set" is required if the program
 name is "less" but optional if any of the other three names are
 used. If any option setting is of the form "tabstop=n" or
 "ts=n", then tab stops are automatically set as if --tabs=n had
 been given. See the --tabs description for acceptable values of
 n.
 --mouse
 Enables mouse input: scrolling the mouse wheel down moves
 forward in the file, scrolling the mouse wheel up moves
 backwards in the file, left-click sets the "#" mark to the line
 where the mouse is clicked, and right-click (or any other)
 returns to the "#" mark position. Holding down the left button
 and dragging also moves in the file. If a left-click is
 performed with the mouse cursor on an OSC 8 hyperlink, the
 hyperlink is selected as if by the ^O^N command. If a left-
 click is performed with the mouse cursor on an OSC 8 hyperlink
 which is already selected, the hyperlink is opened as if by the
 ^O^O command. The number of lines to scroll when the wheel is
 moved can be set by the --wheel-lines option. Mouse input works
 only on terminals which support X11 mouse reporting, and on the
 Windows version of less.
 --MOUSE
 Like --mouse, except the direction scrolled on mouse wheel
 movement is reversed.
 --no-edit-warn
 Don't print a warning message when using the v command on a file
 which was opened using a LESSOPEN preprocessor (see the INPUT
 PREPROCESSOR section below).
 --no-keypad
 Disables sending the keypad initialization and deinitialization
 strings to the terminal. This is sometimes useful if the keypad
 strings make the numeric keypad behave in an undesirable manner.
 --no-histdups
 This option changes the behavior so that if a search string or
 file name is typed in, and the same string is already in the
 history list, the existing copy is removed from the history list
 before the new one is added. Thus, a given string will appear
 only once in the history list. Normally, a string may appear
 multiple times.
 --no-number-headers
 Header lines (defined via the --header option) are not assigned
 line numbers. Line number 1 is assigned to the first line after
 any header lines.
 --no-paste
 If the terminal supports xterm-compatible "bracketed paste", any
 text pasted into less is ignored, except that one line of text
 may be pasted into the command line at the bottom of the screen
 (search strings, file names, etc). That is, the first newline
 of text pasted into the command line and any text that follows
 it is ignored.
 --no-search-header-lines
 Searches do not include header lines, but still include header
 columns.
 --no-search-header-columns
 Searches do not include header columns, but still include header
 lines.
 --no-search-headers
 Searches do not include header lines or header columns.
 --no-vbell
 Disables the terminal's visual bell.
 --proc-backspace
 If set, backspaces are handled as if neither the -u option nor
 the -U option were set. That is, a backspace adjacent to an
 underscore causes text to be displayed in underline mode, and a
 backspace between identical characters cause text to be
 displayed in boldface mode. This option overrides the -u and -U
 options, so that display of backspaces can be controlled
 separate from tabs and carriage returns. If not set, backspace
 display is controlled by the -u and -U options.
 --PROC-BACKSPACE
 If set, backspaces are handled as if the -U option were set;
 that is backspaces are treated as control characters.
 --proc-return
 If set, carriage returns are handled as if neither the -u option
 nor the -U option were set. That is, a carriage return
 immediately before a newline is deleted. This option overrides
 the -u and -U options, so that display of carriage returns can
 be controlled separate from that of backspaces and tabs. If not
 set, carriage return display is controlled by the -u and -U
 options.
 --PROC-RETURN
 If set, carriage returns are handled as if the -U option were
 set; that is carriage returns are treated as control characters.
 --proc-tab
 If set, tabs are handled as if the -U option were not set. That
 is, tabs are expanded to spaces. This option overrides the -U
 option, so that display of tabs can be controlled separate from
 that of backspaces and carriage returns. If not set, tab
 display is controlled by the -U option.
 --PROC-TAB
 If set, tabs are handled as if the -U option were set; that is
 tabs are treated as control characters.
 --redraw-on-quit
 When quitting, after sending the terminal deinitialization
 string, redraws the entire last screen. On terminals whose
 terminal deinitialization string causes the terminal to switch
 from an alternate screen, this makes the last screenful of the
 current file remain visible after less has quit.
 --rscroll=c
 This option changes the character used to mark truncated lines.
 It may begin with a two-character attribute indicator like
 LESSBINFMT does. If there is no attribute indicator, standout
 is used. If set to "-", truncated lines are not marked.
 --save-marks
 Save marks in the history file, so marks are retained across
 different invocations of less.
 --search-options=...
 Sets default search modifiers. The value is a string of one or
 more of the characters E, F, K, N, R or W. Setting any of these
 has the same effect as typing that control character at the
 beginning of every search pattern. For example, setting
 --search-options=W is the same as typing ^W at the beginning of
 every pattern. The value may also contain a digit between 1 and
 5, which has the same effect as typing ^S followed by that digit
 at the beginning of every search pattern. The value "-"
 disables all default search modifiers.
 --show-preproc-errors
 If a preprocessor produces data, then exits with a non-zero exit
 code, less will display a warning.
 --status-col-width=n
 Sets the width of the status column when the -J option is in
 effect. The default is 2 characters.
 --status-line
 If a line is marked, the entire line (rather than just the
 status column) is highlighted. Also lines highlighted due to
 the -w option will have the entire line highlighted. If --use-
 color is set, the line is colored rather than highlighted.
 --use-backslash
 This option changes the interpretations of options which follow
 this one. After the --use-backslash option, any backslash in an
 option string is removed and the following character is taken
 literally. This allows a dollar sign to be included in option
 strings.
 --use-color
 Enables colored text in various places. The -D option can be
 used to change the colors. Colored text works only if the
 terminal supports ANSI color escape sequences (as defined in
 <https://www.ecma-international.org/publications-and-standards/standards/ecma-48 >).
 --wheel-lines=n
 Set the number of lines to scroll when the mouse wheel is
 scrolled and the --mouse or --MOUSE option is in effect. The
 default is 1 line.
 --wordwrap
 When the -S option is not in use, wrap each line at a space or
 tab if possible, so that a word is not split between two lines.
 The default is to wrap at any character.
 -- A command line argument of "--" marks the end of option
 arguments. Any arguments following this are interpreted as
 filenames. This can be useful when viewing a file whose name
 begins with a "-" or "+".
 + If a command line option begins with +, the remainder of that
 option is taken to be an initial command to less. For example,
 +G tells less to start at the end of the file rather than the
 beginning, and +/xyz tells it to start at the first occurrence
 of "xyz" in the file. As a special case, +<number> acts like
 +<number>g; that is, it starts the display at the specified line
 number (however, see the caveat under the "g" command above).
 If the option starts with ++, the initial command applies to
 every file being viewed, not just the first one. The + command
 described previously may also be used to set (or change) an
 initial command for every file.

LINE EDITING

 When entering a command line at the bottom of the screen (for example,
 a filename for the :e command, or the pattern for a search command),
 certain keys can be used to manipulate the command line. Most commands
 have an alternate form in [ brackets ] which can be used if a key does
 not exist on a particular keyboard. (Note that the forms beginning
 with ESC do not work on some MS-DOS and Windows systems because ESC is
 the line erase character.) Any of these special keys may be entered
 literally by preceding it with the "literal" character, either ^V or
 ^A. A backslash itself may also be entered literally by entering two
 backslashes.
 LEFTARROW [ ESC-h ]
 Move the cursor one space to the left.
 RIGHTARROW [ ESC-l ]
 Move the cursor one space to the right.
 ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
 (That is, CONTROL and LEFTARROW simultaneously.) Move the
 cursor one word to the left.
 ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
 (That is, CONTROL and RIGHTARROW simultaneously.) Move the
 cursor one word to the right.
 HOME [ ESC-0 ]
 Move the cursor to the beginning of the line.
 END [ ESC-$ ]
 Move the cursor to the end of the line.
 BACKSPACE
 Delete the character to the left of the cursor, or cancel the
 command if the command line is empty.
 DELETE or [ ESC-x ]
 Delete the character under the cursor.
 ^BACKSPACE [ ESC-BACKSPACE ]
 (That is, CONTROL and BACKSPACE simultaneously.) Delete the
 word to the left of the cursor.
 ^DELETE [ ESC-X or ESC-DELETE ]
 (That is, CONTROL and DELETE simultaneously.) Delete the word
 under the cursor.
 UPARROW [ ESC-k ]
 Retrieve the previous command line. If you first enter some
 text and then press UPARROW, it will retrieve the previous
 command which begins with that text.
 DOWNARROW [ ESC-j ]
 Retrieve the next command line. If you first enter some text
 and then press DOWNARROW, it will retrieve the next command
 which begins with that text.
 TAB Complete the partial filename to the left of the cursor. If it
 matches more than one filename, the first match is entered into
 the command line. Repeated TABs will cycle thru the other
 matching filenames. If the completed filename is a directory, a
 "/" is appended to the filename. (On MS-DOS and Windows
 systems, a "\" is appended.) The environment variable
 LESSSEPARATOR can be used to specify a different character to
 append to a directory name.
 BACKTAB [ ESC-TAB ]
 Like, TAB, but cycles in the reverse direction thru the matching
 filenames.
 ^L Complete the partial filename to the left of the cursor. If it
 matches more than one filename, all matches are entered into the
 command line (if they fit).
 ^U (Unix and OS/2) or ESC (MS-DOS and Windows)
 Delete the entire command line, or cancel the command if the
 cursor is at the beginning of the command line. If you have
 changed your line-kill character in Unix to something other than
 ^U, that character is used instead of ^U.
 ^G Delete the entire command line and return to the main prompt.

KEY BINDINGS

 You may define your own less commands by creating a lesskey source
 file. This file specifies a set of command keys and an action
 associated with each key. You may also change the line-editing keys
 (see LINE EDITING), and set environment variables used by less. See
 the lesskey(1)  manual page for details about the file format.
 If the environment variable LESSKEYIN is set, less uses that as the
 name of the lesskey source file. Otherwise, less looks in a standard
 place for the lesskey source file: On Unix systems, less looks for a
 lesskey file called "$XDG_CONFIG_HOME/lesskey" or
 "$HOME/.config/lesskey" or "$HOME/.lesskey". On MS-DOS and Windows
 systems, less looks for a lesskey file called "$HOME/_lesskey", and if
 it is not found there, then looks for a lesskey file called "_lesskey"
 in any directory specified in the PATH environment variable. On OS/2
 systems, less looks for a lesskey file called "$HOME/lesskey.ini", and
 if it is not found, then looks for a lesskey file called "lesskey.ini"
 in any directory specified in the INIT environment variable, and if it
 not found there, then looks for a lesskey file called "lesskey.ini" in
 any directory specified in the PATH environment variable.
 A system-wide lesskey source file may also be set up to provide key
 bindings. If a key is defined in both a local lesskey file and in the
 system-wide file, key bindings in the local file take precedence over
 those in the system-wide file. If the environment variable
 LESSKEYIN_SYSTEM is set, less uses that as the name of the system-wide
 lesskey file. Otherwise, less looks in a standard place for the
 system-wide lesskey file: On Unix systems, the system-wide lesskey file
 is /usr/local/etc/syslesskey. (However, if less was built with a
 different sysconf directory than /usr/local/etc, that directory is
 where the sysless file is found.) On MS-DOS and Windows systems, the
 system-wide lesskey file is c:\_syslesskey. On OS/2 systems, the
 system-wide lesskey file is c:\syslesskey.ini.
 Older versions of less (before v582) used lesskey files with a binary
 format, produced by the lesskey program. It is no longer necessary to
 use the lesskey program.

INPUT PREPROCESSOR

 You may define an "input preprocessor" for less. Before less opens a
 file, it first gives the input preprocessor a chance to modify the way
 the contents of the file are displayed. An input preprocessor is
 simply an executable program (or shell script), which writes the
 contents of the file to a different file, called the replacement file.
 The contents of the replacement file are then displayed in place of the
 contents of the original file. However, it will appear to the user as
 if the original file is opened; that is, less will display the original
 filename as the name of the current file.
 An input preprocessor receives one command line argument, the original
 filename, as entered by the user. It should create the replacement
 file, and when finished, print the name of the replacement file to its
 standard output. If the input preprocessor does not output a
 replacement filename, less uses the original file, as normal. The
 input preprocessor is not called when viewing standard input. To set
 up an input preprocessor, set the LESSOPEN environment variable to a
 command line which will invoke your input preprocessor. This command
 line should include one occurrence of the string "%s", which will be
 replaced by the filename when the input preprocessor command is
 invoked.
 When less closes a file opened in such a way, it will call another
 program, called the input postprocessor, which may perform any desired
 clean-up action (such as deleting the replacement file created by
 LESSOPEN). This program receives two command line arguments, the
 original filename as entered by the user, and the name of the
 replacement file. To set up an input postprocessor, set the LESSCLOSE
 environment variable to a command line which will invoke your input
 postprocessor. It may include two occurrences of the string "%s"; the
 first is replaced with the original name of the file and the second
 with the name of the replacement file, which was output by LESSOPEN.
 For example, on many Unix systems, these two scripts will allow you to
 keep files in compressed format, but still let less view them directly:
 lessopen.sh:
 #! /bin/sh
 case "1ドル" in
 *.Z) TEMPFILE=$(mktemp)
 uncompress -c 1ドル >$TEMPFILE 2>/dev/null
 if [ -s $TEMPFILE ]; then
 echo $TEMPFILE
 else
 rm -f $TEMPFILE
 fi
 ;;
 esac
 lessclose.sh:
 #! /bin/sh
 rm 2ドル
 To use these scripts, put them both where they can be executed and set
 LESSOPEN="lessopen.sh %s", and LESSCLOSE="lessclose.sh %s %s". More
 complex LESSOPEN and LESSCLOSE scripts may be written to accept other
 types of compressed files, and so on.
 It is also possible to set up an input preprocessor to pipe the file
 data directly to less, rather than putting the data into a replacement
 file. This avoids the need to decompress the entire file before
 starting to view it. An input preprocessor that works this way is
 called an input pipe. An input pipe, instead of writing the name of a
 replacement file on its standard output, writes the entire contents of
 the replacement file on its standard output. If the input pipe does
 not write any characters on its standard output, then there is no
 replacement file and less uses the original file, as normal. To use an
 input pipe, make the first character in the LESSOPEN environment
 variable a vertical bar (|) to signify that the input preprocessor is
 an input pipe. As with non-pipe input preprocessors, the command
 string must contain one occurrence of %s, which is replaced with the
 filename of the input file.
 For example, on many Unix systems, this script will work like the
 previous example scripts:
 lesspipe.sh:
 #! /bin/sh
 case "1ドル" in
 *.Z) uncompress -c 1ドル 2>/dev/null
 ;;
 *) exit 1
 ;;
 esac
 exit $?
 To use this script, put it where it can be executed and set
 LESSOPEN="|lesspipe.sh %s".
 Note that a preprocessor cannot output an empty file, since that is
 interpreted as meaning there is no replacement, and the original file
 is used. To avoid this, if LESSOPEN starts with two vertical bars, the
 exit status of the script determines the behavior when the output is
 empty. If the output is empty and the exit status is zero, the empty
 output is considered to be replacement text. If the output is empty
 and the exit status is nonzero, the original file is used. For
 compatibility with previous versions of less, if LESSOPEN starts with
 only one vertical bar, the exit status of the preprocessor is ignored.
 When an input pipe is used, a LESSCLOSE postprocessor can be used, but
 it is usually not necessary since there is no replacement file to clean
 up. In this case, the replacement file name passed to the LESSCLOSE
 postprocessor is "-".
 For compatibility with previous versions of less, the input
 preprocessor or pipe is not used if less is viewing standard input.
 However, if the first character of LESSOPEN is a dash (-), the input
 preprocessor is used on standard input as well as other files. In this
 case, the dash is not considered to be part of the preprocessor
 command. If standard input is being viewed, the input preprocessor is
 passed a file name consisting of a single dash. Similarly, if the
 first two characters of LESSOPEN are vertical bar and dash (|-) or two
 vertical bars and a dash (||-), the input pipe is used on standard
 input as well as other files. Again, in this case the dash is not
 considered to be part of the input pipe command.

NATIONAL CHARACTER SETS

 There are three types of characters in the input file:
 normal characters
 can be displayed directly to the screen.
 control characters
 should not be displayed directly, but are expected to be found
 in ordinary text files (such as backspace and tab).
 binary characters
 should not be displayed directly and are not expected to be
 found in text files.
 A "character set" is simply a description of which characters are to be
 considered normal, control, and binary. The LESSCHARSET environment
 variable may be used to select a character set. Possible values for
 LESSCHARSET are:
 ascii BS, TAB, NL, CR, and formfeed are control characters, all chars
 with values between 32 and 126 are normal, and all others are
 binary.
 iso8859
 Selects an ISO 8859 character set. This is the same as ASCII,
 except characters between 160 and 255 are treated as normal
 characters.
 latin1 Same as iso8859.
 latin9 Same as iso8859.
 dos Selects a character set appropriate for MS-DOS.
 ebcdic Selects an EBCDIC character set.
 IBM-1047
 Selects an EBCDIC character set used by OS/390 Unix Services.
 This is the EBCDIC analogue of latin1. You get similar results
 by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
 environment.
 koi8-r Selects a Russian character set.
 next Selects a character set appropriate for NeXT computers.
 utf-8 Selects the UTF-8 encoding of the ISO 10646 character set.
 UTF-8 is special in that it supports multi-byte characters in
 the input file. It is the only character set that supports
 multi-byte characters.
 windows
 Selects a character set appropriate for Microsoft Windows (cp
 1252).
 In rare cases, it may be desired to tailor less to use a character set
 other than the ones definable by LESSCHARSET. In this case, the
 environment variable LESSCHARDEF can be used to define a character set.
 It should be set to a string where each character in the string
 represents one character in the character set. The character "." is
 used for a normal character, "c" for control, and "b" for binary. A
 decimal number may be used for repetition. For example, "bccc4b."
 would mean character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7
 are binary, and 8 is normal. All characters after the last are taken
 to be the same as the last, so characters 9 through 255 would be
 normal. (This is an example, and does not necessarily represent any
 real character set.)
 This table shows the value of LESSCHARDEF which is equivalent to each
 of the possible values for LESSCHARSET:
 ascii 8bcccbcc18b95.b
 dos 8bcccbcc12bc5b95.b.
 ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
 IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
 191.b
 iso8859 8bcccbcc18b95.33b.
 koi8-r 8bcccbcc18b95.b128.
 latin1 8bcccbcc18b95.33b.
 next 8bcccbcc18b95.bb125.bb
 If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
 "UTF-8", "UTF8", "utf-8" or "utf8" is found in the LC_ALL, LC_CTYPE or
 LANG environment variables, then the default character set is utf-8.
 If that string is not found, but your system supports the setlocale
 interface, less will use setlocale to determine the character set.
 setlocale is controlled by setting the LANG or LC_CTYPE environment
 variables.
 Finally, if the setlocale interface is also not available, the default
 character set is utf-8.
 Control and binary characters are displayed in standout (reverse
 video). Each such character is displayed in caret notation if possible
 (e.g. ^A for control-A). Caret notation is used only if inverting the
 0100 bit results in a normal printable character. Otherwise, the
 character is displayed as a hex number in angle brackets. This format
 can be changed by setting the LESSBINFMT environment variable.
 LESSBINFMT may begin with a "*" and one character to select the display
 attribute: "*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is
 standout, and "*n" is normal. If LESSBINFMT does not begin with a "*",
 normal attribute is assumed. The remainder of LESSBINFMT is a string
 which may include one printf-style escape sequence (a % followed by x,
 X, o, d, etc.). For example, if LESSBINFMT is "*u[%x]", binary
 characters are displayed in underlined hexadecimal surrounded by
 brackets. The default if no LESSBINFMT is specified is "*s<%02X>".
 Warning: the result of expanding the character via LESSBINFMT must be
 less than 31 characters.
 When the character set is utf-8, the LESSUTFBINFMT environment variable
 acts similarly to LESSBINFMT but it applies to Unicode code points that
 were successfully decoded but are unsuitable for display (e.g.,
 unassigned code points). Its default value is "<U+%04lX>". Note that
 LESSUTFBINFMT and LESSBINFMT share their display attribute setting
 ("*x") so specifying one will affect both; LESSUTFBINFMT is read after
 LESSBINFMT so its setting, if any, will have priority. Problematic
 octets in a UTF-8 file (octets of a truncated sequence, octets of a
 complete but non-shortest form sequence, invalid octets, and stray
 trailing octets) are displayed individually using LESSBINFMT so as to
 facilitate diagnostic of how the UTF-8 file is ill-formed.
 When the character set is utf-8, in rare cases it may be desirable to
 override the Unicode definition of the type of certain characters. For
 example, characters in a Private Use Area are normally treated as
 control characters, but if you are using a custom font with printable
 characters in that range, it may be desirable to tell less to treat
 such characters as printable. This can be done by setting the
 LESSUTFCHARDEF environment variable to a comma-separated list of
 character type definitions. Each character type definition consists of
 either one hexadecimal codepoint or a pair of codepoints separated by a
 dash, followed by a colon and a type character. Each hexadecimal
 codepoint may optionally be preceded by a "U" or "U+". If a pair of
 codepoints is given, the type is set for all characters inclusively
 between the two values. If there are multiple comma-separated
 codepoint values, they must be in ascending numerical order. The type
 character may be one of:
 p A normal printable character.
 w A wide (2-space) printable character.
 b A binary (non-printable) character.
 c A composing (zero width) character.
 For example, setting LESSUTFCHARDEF to
 E000-F8FF:p,F0000-FFFFD:p,100000-10FFFD:p
 would make all Private Use Area characters be treated as printable.

PROMPTS

 The -P option allows you to tailor the prompt to your preference. The
 string given to the -P option replaces the specified prompt string.
 Certain characters in the string are interpreted specially. The prompt
 mechanism is rather complicated to provide flexibility, but the
 ordinary user need not understand the details of constructing
 personalized prompt strings.
 A percent sign followed by a single character is expanded according to
 what the following character is. (References to the input file size
 below refer to the preprocessed size, if an input preprocessor is being
 used.)
 %bX Replaced by the byte offset into the current input file. The b
 is followed by a single character (shown as X above) which
 specifies the line whose byte offset is to be used. If the
 character is a "t", the byte offset of the top line in the
 display is used, an "m" means use the middle line, a "b" means
 use the bottom line, a "B" means use the line just after the
 bottom line, and a "j" means use the "target" line, as specified
 by the -j option.
 %B Replaced by the size of the current input file.
 %c Replaced by the column number of the text appearing in the first
 column of the screen.
 %dX Replaced by the page number of a line in the input file. The
 line to be used is determined by the X, as with the %b option.
 %D Replaced by the number of pages in the input file, or
 equivalently, the page number of the last line in the input
 file.
 %E Replaced by the name of the editor (from the VISUAL environment
 variable, or the EDITOR environment variable if VISUAL is not
 defined). See the discussion of the LESSEDIT feature below.
 %f Replaced by the name of the current input file.
 %F Replaced by the last component of the name of the current input
 file.
 %g Replaced by the shell-escaped name of the current input file.
 This is useful when the expanded string will be used in a shell
 command, such as in LESSEDIT.
 %i Replaced by the index of the current file in the list of input
 files.
 %lX Replaced by the line number of a line in the input file. The
 line to be used is determined by the X, as with the %b option.
 %L Replaced by the line number of the last line in the input file.
 %m Replaced by the total number of input files.
 %o Replaced by the URI of the currently selected OSC 8 hyperlink,
 or a question mark if no hyperlink is selected. This is used by
 OSC 8 handlers as explained in the ^O^O command description.
 %pX Replaced by the percent into the current input file, based on
 byte offsets. The line used is determined by the X as with the
 %b option.
 %PX Replaced by the percent into the current input file, based on
 line numbers. The line used is determined by the X as with the
 %b option.
 %s Same as %B.
 %t Causes any trailing spaces to be removed. Usually used at the
 end of the string, but may appear anywhere.
 %T Normally expands to the word "file". However if viewing files
 via a tags list using the -t option, it expands to the word
 "tag".
 %x Replaced by the name of the next input file in the list.
 If any item is unknown (for example, the file size if input is a pipe),
 a question mark is printed instead.
 The format of the prompt string can be changed depending on certain
 conditions. A question mark followed by a single character acts like
 an "IF": depending on the following character, a condition is
 evaluated. If the condition is true, any characters following the
 question mark and condition character, up to a period, are included in
 the prompt. If the condition is false, such characters are not
 included. A colon appearing between the question mark and the period
 can be used to establish an "ELSE": any characters between the colon
 and the period are included in the string if and only if the IF
 condition is false. Condition characters (which follow a question
 mark) may be:
 ?a True if any characters have been included in the prompt so far.
 ?bX True if the byte offset of the specified line is known.
 ?B True if the size of current input file is known.
 ?c True if the text is horizontally shifted (%c is not zero).
 ?dX True if the page number of the specified line is known.
 ?e True if at end-of-file.
 ?f True if there is an input filename (that is, if input is not a
 pipe).
 ?lX True if the line number of the specified line is known.
 ?L True if the line number of the last line in the file is known.
 ?m True if there is more than one input file.
 ?n True if this is the first prompt in a new input file.
 ?pX True if the percent into the current input file, based on byte
 offsets, of the specified line is known.
 ?PX True if the percent into the current input file, based on line
 numbers, of the specified line is known.
 ?s Same as "?B".
 ?x True if there is a next input file (that is, if the current
 input file is not the last one).
 Any characters other than the special ones (question mark, colon,
 period, percent, and backslash) become literally part of the prompt.
 Any of the special characters may be included in the prompt literally
 by preceding it with a backslash.
 Some examples:
 ?f%f:Standard input.
 This prompt prints the filename, if known; otherwise the string
 "Standard input".
 ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
 This prompt would print the filename, if known. The filename is
 followed by the line number, if known, otherwise the percent if known,
 otherwise the byte offset if known. Otherwise, a dash is printed.
 Notice how each question mark has a matching period, and how the %
 after the %pt is included literally by escaping it with a backslash.
 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x..%t
 This prints the filename if this is the first prompt in a file,
 followed by the "file N of N" message if there is more than one input
 file. Then, if we are at end-of-file, the string "(END)" is printed
 followed by the name of the next file, if there is one. Finally, any
 trailing spaces are truncated. This is the default prompt. For
 reference, here are the defaults for the other two prompts (-m and -M
 respectively). Each is broken into two lines here for readability
 only.
 ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x.:
 ?pB%pB\%:byte %bB?s/%s...%t
 ?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :
 byte %bB?s/%s. .?e(END) ?x- Next\: %x.:?pB%pB\%..%t
 And here is the default message produced by the = command:
 ?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .
 byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
 The prompt expansion features are also used for another purpose: if an
 environment variable LESSEDIT is defined, it is used as the command to
 be executed when the v command is invoked. The LESSEDIT string is
 expanded in the same way as the prompt strings. The default value for
 LESSEDIT is:
 %E ?lm+%lm. %g
 Note that this expands to the editor name, followed by a + and the line
 number, followed by the shell-escaped file name. If your editor does
 not accept the "+linenumber" syntax, or has other differences in
 invocation syntax, the LESSEDIT variable can be changed to modify this
 default.

SECURITY

 When the environment variable LESSSECURE is set to 1, less runs in a
 "secure" mode. In this mode, these features are disabled:
 edit the edit command (v)
 examine the examine command (:e)
 glob metacharacters such as * in filenames,
 and filename completion (TAB, ^L)
 history history file
 lesskey use of lesskey files (-k and --lesskey-src)
 lessopen input preprocessor (LESSOPEN environment variable)
 logfile log files (s and -o)
 osc8 opening OSC 8 links (^O^O)
 pipe the pipe command (|)
 shell the shell and pshell commands (! and #)
 stop stopping less via a SIGTSTP signal
 tags use of tags files (-t)
 The LESSSECURE_ALLOW environment variable can be set to a comma-
 separated list of names of features which are selectively enabled when
 LESSSECURE is set. Each feature name is the first word in each line in
 the above list. A feature name may be abbreviated as long as the
 abbreviation is unambiguous. For example, if LESSSECURE=1 and
 LESSSECURE_ALLOW=hist,edit were set, all of the above features would be
 disabled except for history files and the edit command.
 Less can also be compiled to be permanently in "secure" mode. In that
 case, the LESSSECURE and LESSSECURE_ALLOW variables are ignored.

COMPATIBILITY WITH MORE

 If the environment variable LESS_IS_MORE is set to 1, or if the program
 is invoked via a file link named "more" and the environment variable
 LESS_IS_MORE is not set to 0, less behaves (mostly) in conformance with
 the POSIX more(1)  command specification. In this mode, less behaves
 differently in these ways:
 The -e option works differently. If the -e option is not set, less
 behaves as if the -e option were set. If the -e option is set, less
 behaves as if the -E option were set.
 The -m option works differently. If the -m option is not set, the
 medium prompt is used, and it is prefixed with the string "--More--".
 If the -m option is set, the short prompt is used.
 The -n option acts like the -z option. The normal behavior of the -n
 option is unavailable in this mode.
 The parameter to the -p option is taken to be a less command rather
 than a search pattern.
 The LESS environment variable is ignored, and the MORE environment
 variable is used in its place.

ENVIRONMENT VARIABLES

 Environment variables may be specified either in the system environment
 as usual, or in a lesskey(1)  file. If environment variables are
 defined in more than one place, variables defined in a local lesskey
 file take precedence over variables defined in the system environment,
 which take precedence over variables defined in the system-wide lesskey
 file.
 COLUMNS
 Sets the number of columns on the screen. Takes precedence over
 the number of columns specified by the TERM variable. (But if
 you have a windowing system which supports TIOCGWINSZ or
 WIOCGETD, the window system's idea of the screen size takes
 precedence over the LINES and COLUMNS environment variables.)
 EDITOR The name of the editor (used for the v command).
 HOME Name of the user's home directory (used to find a lesskey file
 on Unix and OS/2 systems).
 HOMEDRIVE, HOMEPATH
 Concatenation of the HOMEDRIVE and HOMEPATH environment
 variables is the name of the user's home directory if the HOME
 variable is not set (only in the Windows version).
 INIT Name of the user's init directory (used to find a lesskey file
 on OS/2 systems).
 LANG Language for determining the character set.
 LC_CTYPE
 Language for determining the character set.
 LESS Options which are passed to less automatically.
 LESSANSIENDCHARS
 Characters which may end an ANSI color escape sequence (default
 "m").
 LESSANSIMIDCHARS
 Characters which may appear between the ESC character and the
 end character in an ANSI color escape sequence (default
 "0123456789:;[?!"'#%()*+ ").
 LESSANSIOSCALLOW
 A comma-separated list of OSC types which are output directly to
 the terminal when -R is in effect. By default, only OSC 8
 sequences are output directly.
 LESSANSIOSCCHARS
 Characters which may follow an ESC character to mark the start
 of an "OS Command" sequence. All characters that follow this
 character up to a String Terminator (ESC-backslash or BEL) are
 considered to be part of the OSC sequence (default "]"). If a
 character in LESSANSIOSCCHARS is followed by an asterisk,
 sequences that begin with that character in the file contents
 are passed through to the terminal; otherwise only sequences
 that appear in a prompt string are passed through.
 LESSBINFMT
 Format for displaying non-printable, non-control characters.
 LESSCHARDEF
 Defines a character set.
 LESSCHARSET
 Selects a predefined character set.
 LESSCLOSE
 Command line to invoke the (optional) input-postprocessor.
 LESSECHO
 Name of the lessecho program (default "lessecho"). The lessecho
 program is needed to expand metacharacters, such as * and ?, in
 filenames on Unix systems.
 LESSEDIT
 Editor prototype string (used for the v command). See
 discussion under PROMPTS.
 LESSGLOBALTAGS
 Name of the command used by the -t option to find global tags.
 Normally should be set to "global" if your system has the
 global(1) command. If not set, global tags are not used.
 LESSHISTFILE
 Name of the history file used to remember search commands and
 shell commands between invocations of less. If set to "-" or
 "/dev/null", a history file is not used. The default depends on
 the operating system, but is usually:
 Linux and Unix
 "$XDG_STATE_HOME/lesshst" or "$HOME/.local/state/lesshst"
 or "$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst".
 Windows and MS-DOS
 "$HOME/_lesshst".
 OS/2 "$HOME/lesshst.ini" or "$INIT/lesshst.ini".
 LESSHISTSIZE
 The maximum number of commands to save in the history file. The
 default is 100.
 LESSKEYIN
 Name of the default lesskey source file.
 LESSKEY
 Name of the default lesskey binary file. (Not used if
 "$LESSKEYIN" exists.)
 LESSKEY_CONTENT
 The value is parsed as if it were the parameter of a --lesskey-
 content option.
 LESSKEYIN_SYSTEM
 Name of the default system-wide lesskey source file.
 LESSKEY_SYSTEM
 Name of the default system-wide lesskey binary file. (Not used
 if "$LESSKEYIN_SYSTEM" exists.)
 LESSMETACHARS
 List of characters which are considered "metacharacters" by the
 shell.
 LESSMETAESCAPE
 Prefix which less will add before each metacharacter in a
 command sent to the shell. If LESSMETAESCAPE is an empty
 string, commands containing metacharacters will not be passed to
 the shell.
 LESSOPEN
 Command line to invoke the (optional) input-preprocessor.
 LESSSECURE
 Runs less in "secure" mode. See discussion under SECURITY.
 LESSSECURE_ALLOW
 Enables individual features which are normally disabled by
 LESSSECURE. See discussion under SECURITY.
 LESSSEPARATOR
 String to be appended to a directory name in filename
 completion.
 LESSUTFBINFMT
 Format for displaying non-printable Unicode code points.
 LESSUTFCHARDEF
 Overrides the type of specified Unicode characters.
 LESS_COLUMNS
 Sets the number of columns on the screen. Unlike COLUMNS, takes
 precedence over the system's idea of the screen size, so it can
 be used to make less use less than the full screen width. If
 set to a negative number, sets the number of columns used to
 this much less than the actual screen width.
 LESS_LINES
 Sets the number of lines on the screen. Unlike LINES, takes
 precedence over the system's idea of the screen size, so it can
 be used to make less use less than the full screen height. If
 set to a negative number, sets the number of lines used to this
 much less than the actual screen height. When set, less
 repaints the entire screen on every movement command, so
 scrolling may be slower.
 LESS_DATA_DELAY
 Duration (in milliseconds) after starting to read data from the
 input, after which the "Waiting for data" message will be
 displayed. The default is 4000 (4 seconds).
 LESS_IS_MORE
 Emulate the more(1)  command.
 LESS_OSC8_xxx
 Where "xxx" is a URI scheme such as "http" or "file", sets an
 OSC 8 handler for opening OSC 8 links containing a URI with that
 scheme.
 LESS_OSC8_ANY
 Sets an OSC 8 handler for opening OSC 8 links for which there is
 no specific LESS_OSC8_xxx handler set for the "xxx" scheme.
 LESS_SHELL_LINES
 When the -F option is set, less exits automatically if the
 number of screen lines used to display the file is less than or
 equal to the screen height minus the value of the
 LESS_SHELL_LINES variable. Thus, if you use a shell prompt
 which occupies more than one screen line, this variable can be
 set to the number of lines used by your prompt, to ensure that
 the entire file can be seen when -F is used. If not set,
 LESS_SHELL_LINES is assumed to be 1.
 LESS_SIGUSR1
 If set to a string of one or more less command characters, those
 commands will be executed when less receives a SIGUSR1 signal.
 LESS_TERMCAP_xx
 Where "xx" is any two characters, overrides the definition of
 the termcap "xx" capability for the terminal.
 LESS_UNSUPPORT
 A space-separated list of command line options. These options
 will be ignored (with no error message) if they appear on the
 command line or in the LESS environment variable. Options
 listed in LESS_UNSUPPORT can still be changed by the - and --
 commands. Each option in LESS_UNSUPPORT is a dash followed by a
 single character option letter, or two dashes followed by a long
 option name.
 LINES Sets the number of lines on the screen. Takes precedence over
 the number of lines specified by the TERM variable. (But if you
 have a windowing system which supports TIOCGWINSZ or WIOCGETD,
 the window system's idea of the screen size takes precedence
 over the LINES and COLUMNS environment variables.)
 MORE Options which are passed to less automatically when running in
 more-compatible mode.
 PATH User's search path (used to find a lesskey file on MS-DOS,
 Windows, and OS/2 systems).
 SHELL The shell used to execute the ! command, as well as to expand
 filenames.
 TERM The type of terminal on which less is being run.
 VISUAL The name of the editor (used for the v command).
 XDG_CONFIG_HOME
 Possible location of the lesskey file; see the KEY BINDINGS
 section.
 XDG_DATA_HOME
 Possible location of the history file; see the description of
 the LESSHISTFILE environment variable.
 XDG_STATE_HOME
 Possible location of the history file; see the description of
 the LESSHISTFILE environment variable.

SEE ALSO

 lesskey(1) , lessecho(1) 

COPYRIGHT

 Copyright (C) 1984-2025 Mark Nudelman
 less is part of the GNU project and is free software. You can
 redistribute it and/or modify it under the terms of either (1) the GNU
 General Public License as published by the Free Software Foundation; or
 (2) the Less License. See the file README in the less distribution for
 more details regarding redistribution. You should have received a copy
 of the GNU General Public License along with the source for less; see
 the file COPYING. If not, write to the Free Software Foundation, 59
 Temple Place, Suite 330, Boston, MA 02111-1307, USA. You should also
 have received a copy of the Less License; see the file LICENSE.
 less is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or
 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 for more details.

AUTHOR

 Mark Nudelman
 Report bugs at <https://github.com/gwsw/less/issues >.
 For more information, see the less homepage at
 <https://greenwoodsoftware.com/less >.
 Version 678: 01 May 2025 less(1)