Adding upstream version 4.22.0.upstream/4.22.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2335 insertions, 0 deletions

diff --git a/upstream/opensuse-leap-15-6/man1/less.1 b/upstream/opensuse-leap-15-6/man1/less.1
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+'\" t
+.TH LESS 1 "Version 643: 20 Jul 2023"
+.SH NAME
+less \- opposite of more
+.SH SYNOPSIS
+.B "less \-?"
+.br
+.B "less \-\-help"
+.br
+.B "less \-V"
+.br
+.B "less \-\-version"
+.br
+.B "less [\-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX\(ti]"
+.br
+.B "     [\-b \fIspace\/\fP] [\-h \fIlines\/\fP] [\-j \fIline\/\fP] [\-k \fIkeyfile\/\fP]"
+.br
+.B "     [\-{oO} \fIlogfile\/\fP] [\-p \fIpattern\/\fP] [\-P \fIprompt\/\fP] [\-t \fItag\/\fP]"
+.br
+.B "     [\-T \fItagsfile\/\fP] [\-x \fItab\/\fP,...] [\-y \fIlines\/\fP] [\-[z] \fIlines\/\fP]"
+.br
+.B "     [\-# \fIshift\/\fP] [+[+]\fIcmd\/\fP] [\-\-] [\fIfilename\/\fP]..."
+.br
+(See the OPTIONS section for alternate option syntax with long option names.)
+.
+.SH DESCRIPTION
+.B Less
+is a program similar to
+.BR more (1),
+but which allows backward movement
+in the file as well as forward movement.
+Also,
+.B 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
+.BR vi (1).
+.B 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.)
+.PP
+Commands are based on both
+.B more
+and
+.BR vi .
+Commands may be preceded by a decimal number,
+called N in the descriptions below.
+The number is used by some commands, as indicated.
+.
+.SH COMMANDS
+In the following descriptions, \(haX means control-X.
+ESC stands for the ESCAPE key; for example ESC-v means the
+two character sequence "ESCAPE", then "v".
+.IP "h or H"
+Help: display a summary of these commands.
+If you forget all the other commands, remember this one.
+.IP "SPACE or \(haV or f or \(haF"
+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 \(haV as a special literalization character.
+.IP "z"
+Like SPACE, but if N is specified, it becomes the new window size.
+.IP "ESC-SPACE"
+Like SPACE, but scrolls a full screenful, even if it reaches
+end-of-file in the process.
+.IP "ENTER or RETURN or \(haN or e or \(haE or j or \(haJ"
+Scroll forward N lines, default 1.
+The entire N lines are displayed, even if N is more than the screen size.
+.IP "d or \(haD"
+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.
+.IP "b or \(haB 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.
+.IP "w"
+Like ESC-v, but if N is specified, it becomes the new window size.
+.IP "y or \(haY or \(haP or k or \(haK"
+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 \(haY as a special job control character.
+.IP "u or \(haU"
+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.
+.IP "J"
+Like j, but continues to scroll beyond the end of the file.
+.IP "K or Y"
+Like k, but continues to scroll beyond the beginning of the file.
+.IP "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.
+.IP "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.
+.IP "ESC-} or \(haRIGHTARROW"
+Scroll horizontally right to show the end of the longest displayed line.
+.IP "ESC-{ or \(haLEFTARROW"
+Scroll horizontally left back to the first column.
+.IP "r or \(haR or \(haL"
+Repaint the screen.
+.IP 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.
+.IP "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 \(haC).
+On systems which support
+.BR poll (2)
+you can also use \(haX or the character specified by the \-\-intr option.
+If the input is a pipe and the \-\-exit-follow-on-close option is in effect,
+.B less
+will automatically stop waiting for data when the input side 
+of the pipe is closed.
+.IP "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.
+.IP "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.)
+.IP "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.)
+.IP "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.
+.IP "p or %"
+Go to a position N percent into the file.
+N should be between 0 and 100, and may contain a decimal point.
+.IP "P"
+Go to the line containing byte offset N in the file.
+.IP "{"
+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.
+.IP "}"
+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.
+.IP "("
+Like {, but applies to parentheses rather than curly brackets.
+.IP ")"
+Like }, but applies to parentheses rather than curly brackets.
+.IP "["
+Like {, but applies to square brackets rather than curly brackets.
+.IP "]"
+Like }, but applies to square brackets rather than curly brackets.
+.IP "ESC-\(haF"
+Followed by two characters,
+acts like {, but uses the two characters as open and close brackets,
+respectively.
+For example, "ESC \(haF < >" could be used to
+go forward to the > which matches the < in the top displayed line.
+.IP "ESC-\(haB"
+Followed by two characters,
+acts like }, but uses the two characters as open and close brackets,
+respectively.
+For example, "ESC \(haB < >" could be used to
+go backward to the < which matches the > in the bottom displayed line.
+.IP 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.
+.IP M
+Acts like m, except the last displayed line is marked
+rather than the first displayed line.
+.IP "\(aq"
+(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 \(ha or $, jumps to the beginning or end of the
+file respectively.
+Marks are preserved when a new file is examined,
+so the \(aq command can be used to switch between input files.
+.IP "\(haX\(haX"
+Same as single quote.
+.IP "ESC-m"
+Followed by any lowercase or uppercase letter,
+clears the mark identified by that letter.
+.IP /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).
+.sp
+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:
+.RS
+.IP "\(haN or !"
+Search for lines which do NOT match the pattern.
+.IP "\(haE 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.
+.IP "\(haF 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.
+.IP "\(haK"
+Highlight any text which matches the pattern on the current screen,
+but don't move to the first match (KEEP current position).
+.IP "\(haR"
+Don't interpret regular expression metacharacters;
+that is, do a simple textual comparison.
+.IP "\(haS"
+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.
+(Supported only if
+.B less 
+is built with one of the regular expression libraries
+.BR posix ", " pcre ", or " pcre2 ".)"
+Multiple \(haS modifiers can be specified,
+to match more than one sub-pattern.
+.IP "\(haW"
+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 \(haW modifier is set, the \(haE modifier is ignored.
+.RE
+.IP ?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).
+.sp
+Certain characters are special as in the / command:
+.RS
+.IP "\(haN or !"
+Search for lines which do NOT match the pattern.
+.IP "\(haE 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.
+.IP "\(haF 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.
+.IP "\(haK"
+As in forward searches.
+.IP "\(haR"
+As in forward searches.
+.IP "\(haS"
+As in forward searches.
+.IP "\(haW"
+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.
+.RE
+.IP "ESC-/pattern"
+Same as "/*".
+.IP "ESC-?pattern"
+Same as "?*".
+.IP n
+Repeat previous search, for N-th line containing the last pattern.
+If the previous search was modified by \(haN, the search is made for the
+N-th line NOT containing the pattern.
+If the previous search was modified by \(haE, the search continues
+in the next (or previous) file if not satisfied in the current file.
+If the previous search was modified by \(haR, the search is done
+without using regular expressions.
+There is no effect if the previous search was modified by \(haF or \(haK.
+.IP N
+Repeat previous search, but in the reverse direction.
+.IP "ESC-n"
+Repeat previous search, but crossing file boundaries.
+The effect is as if the previous search were modified by *.
+.IP "ESC-N"
+Repeat previous search, but in the reverse direction
+and crossing file boundaries.
+.IP "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.)
+.IP "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.
+.IP "&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.
+.sp
+Certain characters are special as in the / command:
+.RS
+.IP "\(haN or !"
+Display only lines which do NOT match the pattern.
+.IP "\(haR"
+Don't interpret regular expression metacharacters;
+that is, do a simple textual comparison.
+.RE
+.IP ":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).
+.IP "\(haX\(haV or E"
+Same as :e.
+Warning: some systems use \(haV as a special literalization character.
+On such systems, you may not be able to use \(haV.
+.IP ":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.
+.IP ":p"
+Examine the previous file in the command line list.
+If a number N is specified, the N-th previous file is examined.
+.IP ":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.
+.IP ":d"
+Remove the current file from the list of files.
+.IP "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.
+.IP "T"
+Go to the previous tag, if there were more than one matches for the current tag.
+.IP "= or \(haG 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.
+.IP \-
+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 \(haP (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.
+.IP \-\-
+Like the \- command, but takes a long option name (see OPTIONS below)
+rather than a single option letter.
+You must press ENTER or RETURN after typing the option name.
+A \(haP immediately after the second dash suppresses printing of a
+message describing the new setting, as in the \- command.
+.IP \-+
+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 "\-+\fIX\fP" command does the same thing
+as "\-+\fIX\fP" on the command line.)
+This does not work for string-valued options.
+.IP \-\-+
+Like the \-+ command, but takes a long option name
+rather than a single option letter.
+.IP \-!
+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.
+.IP \-\-!
+Like the \-!\& command, but takes a long option name
+rather than a single option letter.
+.IP _
+(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.
+.IP __
+(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.
+.IP +cmd
+Causes the specified cmd to be executed each time a new file is examined.
+For example, +G causes
+.B less
+to initially display each file starting at the end
+rather than the beginning.
+.IP V
+Prints the version number of
+.B less
+being run.
+.IP "q or Q or :q or :Q or ZZ"
+Exits
+.BR less .
+.PP
+The following
+six
+commands may or may not be valid, depending on your particular installation.
+.
+.IP 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.
+.IP "! 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 simply invokes a shell.
+On Unix systems, the shell is taken from the environment variable LESSSHELL,
+or defaults to "sh".
+On MS-DOS and OS/2 systems, the shell is the normal command processor.
+.IP "# 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".
+.IP "| <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 \(ha or $ to indicate beginning or end of file respectively.
+If <m> is \&.\& or newline, the current screen is piped.
+.IP "s filename"
+Save the input to a file.
+This works only if the input is a pipe, not an ordinary file.
+.IP "\(haX"
+When the "Waiting for data" message is displayed,
+such as while in the F command, pressing \(haX
+will stop
+.B less
+from waiting and return to a prompt.
+This may cause
+.B 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 \(haX.
+This command works only on systems that support the
+.BR poll (2)
+function.
+On systems without
+.BR poll (2),
+the interrupt character (usually \(haC) can be used instead.
+.
+.SH OPTIONS
+Command line options are described below.
+Most options may be changed while
+.B less
+is running, via the "\-" command.
+.PP
+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, \-\-quit-at-eof may be abbreviated \-\-quit, but not
+\-\-qui, since both \-\-quit-at-eof and \-\-quiet begin with \-\-qui.
+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.
+.PP
+Options are also taken from the environment variable "LESS".
+For example,
+to avoid typing "less \-options \&...\&" each time
+.B less
+is invoked, you might tell
+.BR csh :
+.sp
+setenv LESS "\-options"
+.sp
+or if you use
+.BR sh :
+.sp
+LESS="\-options"; export LESS
+.sp
+On MS-DOS, you don't need the quotes, but you should replace any
+percent signs in the options string by double percent signs.
+.sp
+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 "\-+".
+.sp
+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 ($) is found.
+For example, you can set two \-D options like this:
+.sp
+LESS="Dn9.1$Ds4.1"
+.sp
+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.
+.IP "\-? or \-\-help"
+This option displays a summary of the commands accepted by
+.B 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: "\-\e?".)
+.IP "\-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.
+.IP "\-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.
+.IP "\-b\fIn\fP or \-\-buffers=\fIn\fP"
+Specifies the amount of buffer space
+.B 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 \fIn\fP kilobytes of
+buffer space should be used for each file.
+If \fIn\fP is \-1, buffer space is unlimited; that is,
+the entire file can be read into memory.
+.IP "\-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.
+.IP "\-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.
+.IP "\-C or \-\-CLEAR-SCREEN"
+Same as \-c, for compatibility with older versions of
+.BR less .
+.IP "\-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
+.B less
+on a dumb terminal.
+.IP "\-D\fBx\fP\fIcolor\fP or \-\-color=\fBx\fP\fIcolor\fP"
+Changes the color of different parts of the displayed text.
+\fBx\fP is a single character which selects the type of text 
+whose color is being set:
+.RS
+.IP "B"
+Binary characters.
+.IP "C"
+Control characters.
+.IP "E"
+Errors and informational messages.
+.IP "H"
+Header lines and columns, set via the \-\-header option.
+.IP "M"
+Mark letters in the status column.
+.IP "N"
+Line numbers enabled via the \-N option.
+.IP "P"
+Prompts.
+.IP "R"
+The rscroll character.
+.IP "S"
+Search results.
+.IP "1-5"
+The text in a search result which matches
+the first through fifth parenthesized sub-pattern.
+Sub-pattern coloring works only if
+.B less 
+is built with one of the regular expression libraries
+.BR posix ", " pcre ", or " pcre2 .
+.IP "W"
+The highlight enabled via the \-w option.
+.IP "d"
+Bold text.
+.IP "k"
+Blinking text.
+.IP "s"
+Standout text.
+.IP "u"
+Underlined text.
+.RE
+ 
+.RS
+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 "d" and "u" letters refer to bold and underline text formed by 
+overstriking with backspaces (see the \-U option), 
+not to text using ANSI escape sequences with the \-R option.
+.PP
+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.
+.PP
+\fIcolor\fP is either a 4-bit color string or an 8-bit color string:
+.PP
+A 4-bit color string is zero, one or two characters, where 
+the first character specifies the foreground color and 
+the second specifies the background color as follows:
+.IP "b"
+Blue
+.IP "c"
+Cyan
+.IP "g"
+Green
+.IP "k"
+Black
+.IP "m"
+Magenta
+.IP "r"
+Red
+.IP "w"
+White
+.IP "y"
+Yellow
+.PP
+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.
+.PP
+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
+.br
+.nh
+https://en.wikipedia.org/wiki/ANSI_escape_code#SGR)
+.hy
+If either integer is a "-" or is omitted,
+the corresponding color is set to that of normal text.
+On MS-DOS versions of 
+.BR less ,
+8-bit color is not supported; instead, decimal values are interpreted as 4-bit
+CHAR_INFO.Attributes values
+(see 
+.br
+.nh
+https://docs.microsoft.com/en-us/windows/console/char-info-str).
+.hy
+.PP
+On MS-DOS only, the \-Da option may be used to specify strict parsing of 
+ANSI color (SGR) sequences when the \-R option is used.
+Without this option, sequences that change text attributes 
+(bold, underline, etc.) may clear the text color.
+.RE
+.IP "\-e or \-\-quit-at-eof"
+Causes
+.B less
+to automatically exit
+the second time it reaches end-of-file.
+By default, the only way to exit
+.B less
+is via the "q" command.
+.IP "\-E or \-\-QUIT-AT-EOF"
+Causes
+.B less
+to automatically exit the first time it reaches end-of-file.
+.IP "\-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,
+.B 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.
+.IP "\-F or \-\-quit-if-one-screen"
+Causes
+.B less
+to automatically exit
+if the entire file can be displayed on the first screen.
+.IP "\-g or \-\-hilite-search"
+Normally,
+.B 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
+.B less
+to run somewhat faster than the default.
+.IP "\-G or \-\-HILITE-SEARCH"
+The \-G option suppresses all highlighting of strings found by search commands.
+.IP "\-h\fIn\fP or \-\-max-back-scroll=\fIn\fP"
+Specifies a maximum number of lines to scroll backward.
+If it is necessary to scroll backward more than \fIn\fP lines,
+the screen is repainted in a forward direction instead.
+(If the terminal does not have the ability to scroll
+backward, \-h0 is implied.)
+.IP "\-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.
+.IP "\-I or \-\-IGNORE-CASE"
+Like \-i, but searches ignore case even if
+the pattern contains uppercase letters.
+.IP "\-j\fIn\fP or \-\-jump-target=\fIn\fP"
+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 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.
+.IP "\-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:
+.RS
+.IP ">"
+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.
+.IP "<"
+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.
+.IP "="
+The line is both chopped and shifted,
+and there are matches beyond both sides of the screen.
+.IP "*"
+There are matches in the visible part of the line
+but none to the right or left of it.
+.IP "a-z, A-Z"
+The line has been marked with the corresponding letter via the m command.
+.RE
+.IP "\-k\fIfilename\fP or \-\-lesskey-file=\fIfilename\fP"
+Causes
+.B less
+to open and interpret the named file as a
+.BR 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
+.B lesskey
+file.
+.IP "\-\-lesskey-src=\fIfilename\fP"
+Causes
+.B less
+to open and interpret the named file as a 
+.BR 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
+.I "lesskey source"
+file.
+Prior to version 582, the
+.B lesskey
+program needed to be run to convert a 
+.I "lesskey source"
+file to a 
+.I "lesskey binary"
+file for
+.B less
+to use.
+Newer versions of
+.B less
+read the
+.I "lesskey source"
+file directly and ignore the binary file if the source file exists.
+.IP "\-K or \-\-quit-on-intr"
+Causes
+.B less
+to exit immediately (with status 2)
+when an interrupt character (usually \(haC) is typed.
+Normally, an interrupt character causes
+.B 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.
+.IP "\-L or \-\-no-lessopen"
+Ignore the LESSOPEN environment variable
+(see the INPUT PREPROCESSOR section below).
+This option can be set from within
+.BR less ,
+but it will apply only to files opened subsequently, not to the
+file which is currently open.
+.IP "\-m or \-\-long-prompt"
+Causes
+.B less
+to prompt verbosely (like 
+.BR more (1)),
+with the percent into the file.
+By default,
+.B less
+prompts with a colon.
+.IP "\-M or \-\-LONG-PROMPT"
+Causes
+.B less
+to prompt even more verbosely than
+.BR more (1).
+.IP "\-n or \-\-line-numbers"
+Suppresses line numbers.
+The default (to use line numbers) may cause
+.B less
+to run more slowly in some cases, especially with a very large input file.
+Suppressing line numbers with the \-n option will avoid this problem.
+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).
+.IP "\-N or \-\-LINE-NUMBERS"
+Causes a line number to be displayed at the beginning of
+each line in the display.
+.IP "\-o\fIfilename\fP or \-\-log-file=\fIfilename\fP"
+Causes
+.B 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,
+.B less
+will ask for confirmation before overwriting it.
+.IP "\-O\fIfilename\fP or \-\-LOG-FILE=\fIfilename\fP"
+The \-O option is like \-o, but it will overwrite an existing
+file without asking for confirmation.
+.sp
+If no log file has been specified,
+the \-o and \-O options can be used from within
+.B 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
+.BR less .
+.IP "\-p\fIpattern\fP or \-\-pattern=\fIpattern\fP"
+The \-p option on the command line is equivalent to
+specifying +/\fIpattern\fP;
+that is, it tells
+.B less
+to start at the first occurrence of \fIpattern\fP in the file.
+.IP "\-P\fIprompt\fP or \-\-prompt=\fIprompt\fP"
+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
+.B 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).
+.sp 1
+All prompt strings consist of a sequence of
+letters and special escape sequences.
+See the section on PROMPTS for more details.
+.IP "\-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.
+.IP "\-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.
+.IP "\-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 "\(haA"
+(with some exceptions as described under the \-U option).
+Warning: when the \-r option is used,
+.B 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.
+.sp
+USE OF THE \-r OPTION IS NOT RECOMMENDED.
+.IP "\-R or \-\-RAW-CONTROL-CHARS"
+Like \-r, but only ANSI "color" escape sequences and OSC 8 hyperlink
+sequences are output in "raw" form.
+Unlike \-r, the screen appearance is maintained correctly,
+provided that there are no escape sequences in the file 
+other than these types of escape sequences.
+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.
+For the purpose of keeping track of screen appearance,
+these escape sequences are assumed to not move the cursor.
+.sp
+OSC 8 hyperlinks are sequences of the form:
+.sp
+	ESC ] 8 ; \&...\& \\7
+.sp
+The terminating sequence may be either a BEL character (\\7) 
+or the two-character sequence "ESC \\".
+.sp
+ANSI color escape sequences are sequences of the form:
+.sp
+	ESC [ \&...\& m
+.sp
+where the "...\&" is zero or more color specification characters.
+You can make
+.B 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
+.B 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.
+.IP "\-s or \-\-squeeze-blank-lines"
+Causes consecutive blank lines to be squeezed into a single blank line.
+This is useful when viewing
+.B nroff
+output.
+.IP "\-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.
+.IP "\-t\fItag\fP or \-\-tag=\fItag\fP"
+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
+.BR 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
+.BR global (1),
+and that command is executed to find the tag.
+(See 
+.nh
+http://www.gnu.org/software/global/global.html).
+.hy
+The \-t option may also be specified from within
+.B less
+(using the \- command) as a way of examining a new file.
+The command ":t" is equivalent to specifying \-t from within
+.BR less .
+.IP "\-T\fItagsfile\fP or \-\-tag-file=\fItagsfile\fP"
+Specifies a tags file to be used instead of "tags".
+.IP "\-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.
+.IP "\-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.
+.sp
+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.
+.sp
+See also the \-\-proc-backspace, \-\-proc-tab,
+and \-\-proc-return options.
+.IP "\-V or \-\-version"
+Displays the version number of
+.BR less .
+.IP "\-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.
+.IP "\-W or \-\-HILITE-UNREAD"
+Like \-w, but temporarily highlights the first new line after any
+forward movement command larger than one line.
+.IP "\-x\fIn\fP,...\& or \-\-tabs=\fIn\fP,..."
+Sets tab stops.
+If only one \fIn\fP is specified, tab stops are set at multiples of \fIn\fP.
+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 \fIn\fP is 8.
+.IP "\-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.
+.IP "\-y\fIn\fP or \-\-max-forw-scroll=\fIn\fP"
+Specifies a maximum number of lines to scroll forward.
+If it is necessary to scroll forward more than \fIn\fP 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.
+.IP "\-z\fIn\fP or \-\-window=\fIn\fP or \-\fIn\fP"
+Changes the default scrolling window size to \fIn\fP 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
+.BR more (1).
+If the number
+.I n
+is negative, it indicates
+.I n
+lines less than the current screen size.
+For example, if the screen is 24 lines, \fI\-z\-4\fP sets the
+scrolling window to 20 lines.  If the screen is resized to 40 lines,
+the scrolling window automatically changes to 36 lines.
+.IP "\-\(dq\fIcc\fP\ or\ \-\-quotes=\fIcc\fP"
+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).
+.IP "\-\(ti or \-\-tilde"
+Normally lines after end of file are displayed as a single tilde (\(ti).
+This option causes lines after end of file to be displayed as blank lines.
+.IP "\-# 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.
+.IP "\-\-exit-follow-on-close"
+When using the "F" command on a pipe,
+.B less
+will automatically stop waiting for more data when the input side of the 
+pipe is closed.
+.IP "\-\-file-size"
+If \-\-file-size is specified,
+.B 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.
+.IP "\-\-follow-name"
+Normally, if the input file is renamed while an F command is executing,
+.B less
+will continue to display the contents of the original file despite
+its name change.
+If \-\-follow-name is specified, during an F command
+.B 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),
+.B less
+will display the contents of that new file.
+.IP "\-\-header=\fIN[,M]\fP"
+Sets the number of header lines and columns displayed on the screen.
+The value may be of the form "N,M" where N and M are integers,
+to set the header lines to N and the header columns to M,
+or it may be a single integer "N" which sets the header lines to N 
+and the header columns to zero,
+or it may be ",M" which sets the header columns to M and the 
+header lines to zero.
+When N is nonzero, the first N lines at the top
+of the screen are replaced with the first N lines of the file,
+regardless of what part of the file are being viewed.
+When M is nonzero, the characters displayed at the 
+beginning of each line are replaced with the first M characters of the line,
+even if the rest of the line is scrolled horizontally.
+If either N or M is zero, 
+.B less
+stops displaying header lines or columns, respectively.
+(Note that it may be necessary to change the setting of the \-j option
+to ensure that the target line is not obscured by the header line(s).)
+.IP "\-\-incsearch"
+Subsequent search commands will be "incremental"; that is,
+.B less
+will advance to the next line containing the search pattern 
+as each character of the pattern is typed in.
+.IP "\-\-intr=\fIc\fP"
+Use the character \fIc\fP instead of \(haX to interrupt a read
+when the "Waiting for data" message is displayed.
+\fIc\fP 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.
+.IP "\-\-line-num-width=\fIn\fP"
+Sets the minimum width of the line number field when the \-N option is in effect 
+to \fIn\fP characters.
+The default is 7.
+.IP "\-\-modelines=\fIn\fP"
+.RS
+Before displaying a file,
+.B less 
+will read the first \fIn\fP lines to try to find a vim-compatible 
+.IR modeline . 
+If \fIn\fP is zero,
+.B 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.
+.PP
+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=\fIn\fP" or "ts=\fIn\fP",
+then tab stops are automatically set as if \-\-tabs=\fIn\fP had been given.
+See the \-\-tabs description for acceptable values of \fIn\fP.
+.RE
+.IP "\-\-mouse"
+Enables mouse input:
+scrolling the mouse wheel down moves forward in the file,
+scrolling the mouse wheel up moves backwards in the file,
+and clicking the mouse sets the "#" mark to the line
+where the mouse is clicked.
+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
+.BR less .
+.IP "\-\-MOUSE"
+Like \-\-mouse, except the direction scrolled
+on mouse wheel movement is reversed.
+.IP "\-\-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.
+.IP "\-\-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.
+.IP "\-\-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.
+.IP "\-\-no-search-headers"
+Searches do not include header lines or header columns.
+.IP "\-\-no-vbell"
+Disables the terminal's visual bell.
+.IP "\-\-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.
+.IP "\-\-PROC-BACKSPACE"
+If set, backspaces are handled as if the \-U option were set;
+that is backspaces are treated as control characters.
+.IP "\-\-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.
+.IP "\-\-PROC-RETURN"
+If set, carriage returns are handled as if the \-U option were set;
+that is carriage returns are treated as control characters.
+.IP "\-\-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 options.
+.IP "\-\-PROC-TAB"
+If set, tabs are handled as if the \-U option were set;
+that is tabs are treated as control characters.
+.IP "\-\-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
+.B less
+has quit.
+.IP "\-\-rscroll=\fIc\fP"
+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.
+.IP "\-\-save-marks"
+Save marks in the history file, so marks are retained
+across different invocations of
+.BR less .
+.IP "\-\-search-options=\fI...\fP"
+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 \(haW at the beginning of every pattern.
+The value may also contain a digit between 1 and 5,
+which has the same effect as typing \(haS followed by that digit
+at the beginning of every search pattern.
+The value "-" disables all default search modifiers.
+.IP "\-\-show-preproc-errors"
+If a preprocessor produces data, 
+then exits with a non-zero exit code,
+.B less
+will display a warning.
+.IP "\-\-status-col-width=\fIn\fP"
+Sets the width of the status column when the \-J option is in effect.
+The default is 2 characters.
+.IP "\-\-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.
+.IP "\-\-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.
+.IP "\-\-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 ECMA-48 SGR;
+see 
+.br
+.nh
+https://www.ecma-international.org/publications-and-standards/standards/ecma-48).
+.hy
+.IP "\-\-wheel-lines=\fIn\fP"
+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.
+.IP "\-\-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.
+.IP \-\-
+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 "+".
+.IP +
+If a command line option begins with \fB+\fP,
+the remainder of that option is taken to be an initial command to
+.BR less .
+For example, +G tells
+.B 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.
+.
+.SH "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
+in 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 \(haV or \(haA.
+A backslash itself may also be entered literally by entering two backslashes.
+.IP "LEFTARROW [ ESC-h ]"
+Move the cursor one space to the left.
+.IP "RIGHTARROW [ ESC-l ]"
+Move the cursor one space to the right.
+.IP "\(haLEFTARROW [ ESC-b or ESC-LEFTARROW ]"
+(That is, CONTROL and LEFTARROW simultaneously.)
+Move the cursor one word to the left.
+.IP "\(haRIGHTARROW [ ESC-w or ESC-RIGHTARROW ]"
+(That is, CONTROL and RIGHTARROW simultaneously.)
+Move the cursor one word to the right.
+.IP "HOME [ ESC-0 ]"
+Move the cursor to the beginning of the line.
+.IP "END [ ESC-$ ]"
+Move the cursor to the end of the line.
+.IP "BACKSPACE"
+Delete the character to the left of the cursor,
+or cancel the command if the command line is empty.
+.IP "DELETE or [ ESC-x ]"
+Delete the character under the cursor.
+.IP "\(haBACKSPACE [ ESC-BACKSPACE ]"
+(That is, CONTROL and BACKSPACE simultaneously.)
+Delete the word to the left of the cursor.
+.IP "\(haDELETE [ ESC-X or ESC-DELETE ]"
+(That is, CONTROL and DELETE simultaneously.)
+Delete the word under the cursor.
+.IP "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.
+.IP "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.
+.IP "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 systems, a "\e" is appended.)
+The environment variable LESSSEPARATOR can be used to specify a
+different character to append to a directory name.
+.IP "BACKTAB [ ESC-TAB ]"
+Like, TAB, but cycles in the reverse direction thru the matching filenames.
+.IP "\(haL"
+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).
+.IP "\(haU (Unix and OS/2) or ESC (MS-DOS)"
+Delete the entire command line,
+or cancel the command if the command line is empty.
+If you have changed your line-kill character in Unix to something
+other than \(haU, that character is used instead of \(haU.
+.IP "\(haG"
+Delete the entire command line and return to the main prompt.
+.
+.SH "KEY BINDINGS"
+You may define your own
+.B 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
+.BR less .
+See the
+.BR lesskey (1)
+manual page for details about the file format.
+.PP
+If the environment variable LESSKEYIN is set,
+.B less
+uses that as the name of the lesskey source file.
+Otherwise,
+.B less
+looks in a standard place for the lesskey source file:
+On Unix systems,
+.B less
+looks for a lesskey file called "$XDG_CONFIG_HOME/lesskey" or "$HOME/.config/lesskey" or "$HOME/.lesskey".
+On MS-DOS and Windows systems,
+.B less
+looks for a lesskey file called "$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,
+.B 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.
+.PP
+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,
+.B less
+uses that as the name of the system-wide lesskey file.
+Otherwise,
+.B 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
+.B 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:\e_syslesskey.
+On OS/2 systems, the system-wide lesskey file is c:\esyslesskey.ini.
+.PP
+Previous versions of
+.B less
+(before v582) used lesskey files with a binary format, produced by the
+.B lesskey
+program. It is no longer necessary to use the
+.B lesskey
+program.
+.
+.SH "INPUT PREPROCESSOR"
+You may define an "input preprocessor" for
+.BR less .
+Before
+.B less
+opens a file, it first gives your 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,
+.B less
+will display the original filename as the name of the current file.
+.PP
+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,
+.B 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.
+.PP
+When
+.B 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.
+.PP
+For example, on many Unix systems, these two scripts will allow you
+to keep files in compressed format, but still let
+.B less
+view them directly:
+.PP
+lessopen.sh:
+.br
+	#! /bin/sh
+.br
+	case "$1" in
+.br
+	*.Z)	TEMPFILE=$(mktemp)
+.br
+		uncompress \-c $1  >$TEMPFILE  2>/dev/null
+.br
+		if [ \-s $TEMPFILE ]; then
+.br
+			echo $TEMPFILE
+.br
+		else
+.br
+			rm \-f $TEMPFILE
+.br
+		fi
+.br
+		;;
+.br
+	esac
+.PP
+lessclose.sh:
+.br
+	#! /bin/sh
+.br
+	rm $2
+.PP
+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.
+.PP
+It is also possible to set up an input preprocessor to
+pipe the file data directly to
+.BR 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
+.B 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.
+.PP
+For example, on many Unix systems, this script will work like the
+previous example scripts:
+.PP
+lesspipe.sh:
+.br
+	#! /bin/sh
+.br
+	case "$1" in
+.br
+	*.Z)	uncompress \-c $1  2>/dev/null
+.br
+		;;
+.br
+	*)	exit 1
+.br
+		;;
+.br
+	esac
+.br
+	exit $?
+.br
+.PP
+To use this script, put it where it can be executed and set
+LESSOPEN="|lesspipe.sh %s".
+.PP
+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
+.BR less ,
+if LESSOPEN starts with only one vertical bar, the exit status
+of the preprocessor is ignored.
+.PP
+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 "\-".
+.PP
+For compatibility with previous versions of
+.BR less ,
+the input preprocessor or pipe is not used if
+.B 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.
+.
+.SH "NATIONAL CHARACTER SETS"
+There are three types of characters in the input file:
+.IP "normal characters"
+can be displayed directly to the screen.
+.IP "control characters"
+should not be displayed directly, but are expected to be found
+in ordinary text files (such as backspace and tab).
+.IP "binary characters"
+should not be displayed directly and are not expected to be found
+in text files.
+.PP
+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:
+.IP 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.
+.IP iso8859
+Selects an ISO 8859 character set.
+This is the same as ASCII, except characters between 160 and 255 are
+treated as normal characters.
+.IP latin1
+Same as iso8859.
+.IP latin9
+Same as iso8859.
+.IP dos
+Selects a character set appropriate for MS-DOS.
+.IP ebcdic
+Selects an EBCDIC character set.
+.IP 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.
+.IP koi8-r
+Selects a Russian character set.
+.IP next
+Selects a character set appropriate for NeXT computers.
+.IP 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.
+.IP windows
+Selects a character set appropriate for Microsoft Windows (cp 1251).
+.PP
+In rare cases, it may be desired to tailor
+.B 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.)
+.PP
+This table shows the value of LESSCHARDEF which is equivalent
+to each of the possible values for LESSCHARSET:
+.
+.RS 5m
+.TS
+l l.
+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
+.TE
+.RE
+.PP
+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.
+.PP
+If that string is not found, but your system supports the
+.B setlocale
+interface,
+.B less
+will use setlocale to determine the character set.
+setlocale is controlled by setting the LANG or LC_CTYPE environment
+variables.
+.PP
+Finally, if the
+.I setlocale
+interface is also not available, the default character set is latin1.
+.PP
+Control and binary characters are displayed in standout (reverse video).
+Each such character is displayed in caret notation if possible
+(e.g.\& \(haA 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.
+.PP
+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.
+.PP
+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
+.B less
+to treat such characters as printable.
+This can be done by setting the LESSUTFCHARDEF environment variable
+to a comma-separated list of 
+.I "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:
+.RS
+.IP "p"
+A normal printable character.
+.IP "w"
+A wide (2-space) printable character.
+.IP "b"
+A binary (non-printable) character.
+.IP "c"
+A composing (zero width) character.
+.RE
+.PP
+For example, setting LESSUTFCHARDEF to
+.nf
+.sp
+	E000-F8FF:p,F0000-FFFFD:p,100000-10FFFD:p
+.sp
+.fi
+would make all Private Use Area characters be treated as printable.
+.SH "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.
+.sp
+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.)
+.IP "%b\fIX\fP"
+Replaced by the byte offset into the current input file.
+The b is followed by a single character (shown as \fIX\fP 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.
+.IP "%B"
+Replaced by the size of the current input file.
+.IP "%c"
+Replaced by the column number of the text appearing in the first
+column of the screen.
+.IP "%d\fIX\fP"
+Replaced by the page number of a line in the input file.
+The line to be used is determined by the \fIX\fP, as with the %b option.
+.IP "%D"
+Replaced by the number of pages in the input file,
+or equivalently, the page number of the last line in the input file.
+.IP "%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.
+.IP "%f"
+Replaced by the name of the current input file.
+.IP "%F"
+Replaced by the last component of the name of the current input file.
+.IP "%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.
+.IP "%i"
+Replaced by the index of the current file in the list of
+input files.
+.IP "%l\fIX\fP"
+Replaced by the line number of a line in the input file.
+The line to be used is determined by the \fIX\fP, as with the %b option.
+.IP "%L"
+Replaced by the line number of the last line in the input file.
+.IP "%m"
+Replaced by the total number of input files.
+.IP "%p\fIX\fP"
+Replaced by the percent into the current input file, based on byte offsets.
+The line used is determined by the \fIX\fP as with the %b option.
+.IP "%P\fIX\fP"
+Replaced by the percent into the current input file, based on line numbers.
+The line used is determined by the \fIX\fP as with the %b option.
+.IP "%s"
+Same as %B.
+.IP "%t"
+Causes any trailing spaces to be removed.
+Usually used at the end of the string, but may appear anywhere.
+.IP "%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".
+.IP "%x"
+Replaced by the name of the next input file in the list.
+.PP
+If any item is unknown (for example, the file size if input
+is a pipe), a question mark is printed instead.
+.PP
+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:
+.IP "?a"
+True if any characters have been included in the prompt so far.
+.IP "?b\fIX\fP"
+True if the byte offset of the specified line is known.
+.IP "?B"
+True if the size of current input file is known.
+.IP "?c"
+True if the text is horizontally shifted (%c is not zero).
+.IP "?d\fIX\fP"
+True if the page number of the specified line is known.
+.IP "?e"
+True if at end-of-file.
+.IP "?f"
+True if there is an input filename
+(that is, if input is not a pipe).
+.IP "?l\fIX\fP"
+True if the line number of the specified line is known.
+.IP "?L"
+True if the line number of the last line in the file is known.
+.IP "?m"
+True if there is more than one input file.
+.IP "?n"
+True if this is the first prompt in a new input file.
+.IP "?p\fIX\fP"
+True if the percent into the current input file, based on byte offsets,
+of the specified line is known.
+.IP "?P\fIX\fP"
+True if the percent into the current input file, based on line numbers,
+of the specified line is known.
+.IP "?s"
+Same as "?B".
+.IP "?x"
+True if there is a next input file
+(that is, if the current input file is not the last one).
+.PP
+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.
+.PP
+Some examples:
+.sp
+?f%f:Standard input.
+.sp
+This prompt prints the filename, if known;
+otherwise the string "Standard input".
+.sp
+?f%f \&.?ltLine %lt:?pt%pt\e%:?btByte %bt:-...
+.sp
+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.
+.sp
+?n?f%f\ .?m(%T %i of %m)\ ..?e(END)\ ?x-\ Next\e:\ %x..%t";
+.sp
+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.
+.nf
+.sp
+?n?f%f\ .?m(%T\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x.:
+	?pB%pB\e%:byte\ %bB?s/%s...%t
+.sp
+?f%f\ .?n?m(%T\ %i\ of\ %m)\ ..?ltlines\ %lt-%lb?L/%L.\ :
+	byte\ %bB?s/%s.\ .?e(END)\ ?x-\ Next\e:\ %x.:?pB%pB\e%..%t
+.sp
+.fi
+And here is the default message produced by the = command:
+.nf
+.sp
+?f%f\ .?m(%T\ %i\ of\ %m)\ .?ltlines\ %lt-%lb?L/%L.\ .
+	byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\e%..%t
+.fi
+.PP
+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:
+.nf
+.sp
+	%E\ ?lm+%lm.\ %g
+.sp
+.fi
+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.
+.
+.SH SECURITY
+When the environment variable LESSSECURE is set to 1,
+.B less
+runs in a "secure" mode.
+This means these features are disabled:
+.RS
+.IP "!"
+the shell command
+.IP "#"
+the pshell command
+.IP "|"
+the pipe command
+.IP ":e"
+the examine command.
+.IP "v"
+the editing command
+.IP "s  \-o"
+log files
+.IP "\-k"
+use of lesskey files
+.IP "\-t"
+use of tags files
+.IP
+metacharacters in filenames, such as *
+.IP
+filename completion (TAB, \(haL)
+.IP
+history file
+.RE
+.PP
+Less can also be compiled to be permanently in "secure" mode.
+.
+.SH "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",
+.B less
+behaves (mostly) in conformance with the POSIX 
+.BR more (1)
+command specification.
+In this mode, less behaves differently in these ways:
+.PP
+The \-e option works differently.
+If the \-e option is not set,
+.B less
+behaves as if the \-e option were set.
+If the \-e option is set,
+.B less
+behaves as if the \-E option were set.
+.PP
+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.
+.PP
+The \-n option acts like the \-z option.
+The normal behavior of the \-n option is unavailable in this mode.
+.PP
+The parameter to the \-p option is taken to be a
+.B less
+command rather than a search pattern.
+.PP
+The LESS environment variable is ignored,
+and the MORE environment variable is used in its place.
+.
+.SH "ENVIRONMENT VARIABLES"
+Environment variables may be specified either in the system environment
+as usual, or in a
+.BR 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.
+.IP 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.)
+.IP EDITOR
+The name of the editor (used for the v command).
+.IP HOME
+Name of the user's home directory
+(used to find a lesskey file on Unix and OS/2 systems).
+.IP "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).
+.IP INIT
+Name of the user's init directory (used to find a lesskey file on OS/2 systems).
+.IP LANG
+Language for determining the character set.
+.IP LC_CTYPE
+Language for determining the character set.
+.IP LESS
+Options which are passed to
+.B less
+automatically.
+.IP LESSANSIENDCHARS
+Characters which may end an ANSI color escape sequence
+(default "m").
+.IP LESSANSIMIDCHARS
+Characters which may appear between the ESC character and the
+end character in an ANSI color escape sequence
+(default "0123456789:;[?!"\(aq#%()*+\ ".
+.IP LESSBINFMT
+Format for displaying non-printable, non-control characters.
+.IP LESSCHARDEF
+Defines a character set.
+.IP LESSCHARSET
+Selects a predefined character set.
+.IP LESSCLOSE
+Command line to invoke the (optional) input-postprocessor.
+.IP LESSECHO
+Name of the lessecho program (default "lessecho").
+The lessecho program is needed to expand metacharacters, such as * and ?,
+in filenames on Unix systems.
+.IP LESSEDIT
+Editor prototype string (used for the v command).
+See discussion under PROMPTS.
+.IP 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
+.BR global (1)
+command.  If not set, global tags are not used.
+.IP LESSHISTFILE
+Name of the history file used to remember search commands and
+shell commands between invocations of
+.BR less .
+If set to "\-" or "/dev/null", a history file is not used.
+The default depends on the operating system, but is usually:
+.RS
+.IP "Linux and Unix"
+"$XDG_STATE_HOME/lesshst" or "$HOME/.local/state/lesshst" or
+"$XDG_DATA_HOME/lesshst" or "$HOME/.lesshst".
+.IP "Windows and MS-DOS"
+"$HOME/_lesshst".
+.IP "OS/2"
+"$HOME/lesshst.ini" or "$INIT/lesshst.ini".
+.RE
+.IP LESSHISTSIZE
+The maximum number of commands to save in the history file.
+The default is 100.
+.IP LESSKEYIN
+Name of the default
+.I "lesskey source"
+file.
+.IP LESSKEY
+Name of the default
+.I "lesskey binary"
+file. (Not used if "$LESSKEYIN" exists.)
+.IP LESSKEYIN_SYSTEM
+Name of the default system-wide
+.I "lesskey source"
+file.
+.IP LESSKEY_SYSTEM
+Name of the default system-wide
+.I "lesskey binary"
+file. (Not used if "$LESSKEYIN_SYSTEM" exists.)
+.IP LESSMETACHARS
+List of characters which are considered "metacharacters" by the shell.
+.IP 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.
+.IP LESSOPEN
+Command line to invoke the (optional) input-preprocessor.
+.IP LESSSECURE
+Runs less in "secure" mode.
+See discussion under SECURITY.
+.IP LESSSEPARATOR
+String to be appended to a directory name in filename completion.
+.IP LESSUTFBINFMT
+Format for displaying non-printable Unicode code points.
+.IP LESSUTFCHARDEF 
+Overrides the type of specified Unicode characters.
+.IP 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
+.B 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.
+.IP 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
+.B 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,
+.B less
+repaints the entire screen on every movement command,
+so scrolling may be slower.
+.IP 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).
+.IP LESS_IS_MORE
+Emulate the
+.BR more (1)
+command.
+.IP LESS_TERMCAP_xx
+Where "xx" is any two characters, overrides the definition 
+of the termcap "xx" capability for the terminal.
+.IP 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.)
+.IP MORE
+Options which are passed to
+.B less
+automatically when running in
+.BR more "-compatible mode."
+.IP PATH
+User's search path (used to find a lesskey file
+on MS-DOS and OS/2 systems).
+.IP LESSSHELL
+The shell used to execute the !\& command, as well as to expand filenames.
+.IP TERM
+The type of terminal on which
+.B less
+is being run.
+.IP VISUAL
+The name of the editor (used for the v command).
+.IP XDG_CONFIG_HOME
+Possible location of the 
+.B lesskey
+file; see the KEY BINDINGS section.
+.IP XDG_DATA_HOME
+Possible location of the history file; see the description of the LESSHISTFILE environment variable.
+.IP XDG_STATE_HOME
+Possible location of the history file; see the description of the LESSHISTFILE environment variable.
+.
+.SH "SEE ALSO"
+.BR lesskey (1),
+.BR lessecho (1)
+.
+.SH COPYRIGHT
+Copyright (C) 1984-2023  Mark Nudelman
+.PP
+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.
+.PP
+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.
+.
+.SH AUTHOR
+.
+Mark Nudelman
+.br
+Report bugs at https://github.com/gwsw/less/issues.
+.br
+For more information, see the less homepage at
+.br
+https://greenwoodsoftware.com/less