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 va-
riety of terminals. There is even limited support for hardcopy termi-
nals. (On a hardcopy terminal, lines which should be printed at the top
of the screen are prefixed with a caret.)
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.
COMMANDS
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 literaliza-
tion character.
z Like SPACE, but if N is specified, it becomes the new window
size.
ESC-SPACE
Like SPACE, but scrolls a full screenful, even if it reaches end-
of-file in the process.
ENTER or RETURN or ^N or e or ^E or j or ^J
Scroll forward N lines, default 1. The entire N lines are dis-
played, 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 be-
low). If N is more than the screen size, only the final screen-
ful 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 dis-
played, 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-) or RIGHTARROW
Scroll horizontally right N characters, default half the screen
width (see the -# option). If a number N is specified, it be-
comes 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 be-
comes the default for future RIGHTARROW and LEFTARROW commands.
ESC-} or ^RIGHTARROW
Scroll horizontally right to show the end of the longest dis-
played 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, re-
load 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). (Warn-
ing: 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 brack-
ets.
] Like }, but applies to square brackets rather than curly brack-
ets.
ESC-^F Followed by two characters, acts like {, but uses the two charac-
ters 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 charac-
ters 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 posi-
tion at which the last "large" movement command was executed.
Followed by a ^ or $, 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 pat-
tern. 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 cur-
rent screen, but don't move to the first match (KEEP cur-
rent 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-PAT-
TERN will be considered to match the pattern. (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 pat-
tern. 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 dis-
played on the screen or the settings of the -a or -j op-
tions.
^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.
ESC-/pattern
Same as "/*".
ESC-?pattern
Same as "?*".
n Repeat previous search, for N-th line containing the last pat-
tern. If the previous search was modified by ^N, the search is
made for the N-th line NOT containing the pattern. If the previ-
ous 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. 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 sta-
tus 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 file-
name 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 literal-
ization 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 com-
mand 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 hyper-
link.
^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 en-
tered 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 be-
low) rather than a single option letter. You must press ENTER or
RETURN after typing the option name. 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 re-
set the option to its default setting and print a message de-
scribing 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 re-
set the option to the "opposite" of its default setting and print
a message describing the new setting. This does not work for nu-
meric 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 let-
ters, 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 ed-
itor 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 exam-
ined file. "!!" repeats the last shell command. "!" with no
shell command simply invokes a shell. If a ^P (CONTROL-P) is en-
tered 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 cur-
rent 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 hyper-
link, 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 re-
placed 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" fol-
lowed by whitespace and a filename, then instead of
running the opener as a shell command, the speci-
fied 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 over-
ride LESS_OSC8_file, you must set LESS_OSC8_file to "-" to indi-
cate 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 appro-
priately quote parameters in the opener command, to prevent exe-
cution 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 in-
terpreted by prompt expansion (such as percent, dot, colon, back-
slash, 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 re-
turn 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 sys-
tems 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 unambigu-
ous. 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 cap-
italized; 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 exam-
ple, 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 ap-
pears 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 inter-
prets the question mark, it may be necessary to quote the ques-
tion 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 dis-
played screen (except for repeated searches invoked by the n or N
commands, which start after or before the "target" line respec-
tively; 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 allo-
cated. 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 re-
cently viewed part of the piped data is kept in memory; any ear-
lier 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 col-
oring 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 dis-
played 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 se-
quences 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 un-
derlining; the green color has replaced the usual underline for-
matting. 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 mes-
sages as blue text on a bright red background. If either charac-
ter 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:
• The bold (d and *) and blinking (l and &) text attributes
at the end of a color string are not supported.
• Lowercase color selector letters refer to text formatted
by ANSI escape sequences with -R, in addition to over-
struck and non-content text (but see -Da).
• 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 col-
or selector on MS-DOS/Windows.
• Numeric color values ("CSI 38;5" color) following an up-
percase color selector letter are not supported on systems
earlier than Windows 10.
• 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.
• The -Da option makes the behavior of --color more similar
to its behavior on non-MS-DOS/Windows systems by (1) mak-
ing lowercase color selector letters not affect text for-
matted 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 sys-
tems 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 dis-
played on the first screen.
-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 de-
fault.
-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 re-
painted 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 upper-
case letters appear in the search pattern; in other words, if a
pattern contains uppercase letters, then that search does not ig-
nore 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 recal-
culated if the terminal window is resized. If the --header op-
tion is used and the target line specified by -j would be ob-
scured by the header, the target line is moved to the first line
after the header. While the --header option is active, the -S
option is ignored, and lines longer than the screen width are
truncated.
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 nonre-
peated 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 con-
tains 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 match-
es 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 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 stan-
dard 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 ex-
ists. 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 sepa-
rated by either newlines as usual, or by semicolons. A literal
semicolon may be represented by a backslash followed by a semi-
colon.
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 charac-
ter 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 PRE-
PROCESSOR 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. Suppressing line numbers with the -n op-
tion will avoid this problem. Using line numbers means: the line
number will be displayed in the verbose prompt and in the = com-
mand, 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 occur-
rence 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 envi-
ronment variable, rather than being typed in with each less com-
mand. 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 oth-
er 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 exam-
ple, a control-A (octal 001) is displayed as "^A" (with some ex-
ceptions 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 NOT RECOMMENDED.
-R or --RAW-CONTROL-CHARS
Like -r, but only ANSI "color" escape sequences and OSC 8 hyper-
link 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 se-
quences. Color escape sequences are only supported when the col-
or 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 se-
quences are assumed to not move the cursor.
OSC 8 hyperlinks are sequences of the form:
ESC ] 8 ; ... \7
The terminating sequence may be either a BEL character (\7) or
the two-character sequence "ESC \".
ANSI color escape sequences are sequences of the form:
ESC [ ... m
where the "..." is zero or more color specification characters.
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.
-s or --squeeze-blank-lines
Causes consecutive blank lines to be squeezed into a single blank
line. This is useful when viewing nroff output.
-S or --chop-long-lines
Causes lines longer than the screen width to be chopped (truncat-
ed) 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.
-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 direc-
tory 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 ap-
pear in the input.
-U or --UNDERLINE-SPECIAL
Causes backspaces, tabs, carriage returns and "formatting charac-
ters" (as defined by Unicode) to be treated as control charac-
ters; that is, they are handled as specified by the -r option.
By default, if neither -u nor -U is given, backspaces which ap-
pear 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 capabili-
ty. Other backspaces are deleted, along with the preceding char-
acter. 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 un-
derlined can be searched for if neither -u nor -U is in effect.
See also the --proc-backspace, --proc-tab, and --proc-return op-
tions.
-V or --version
Displays the version number of less.
-w or --hilite-unread
Temporarily highlights the first "new" line after a forward move-
ment of a full page. The first "new" line is the line immediate-
ly 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 spec-
ified, 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 re-
painted instead. The -c or -C option may be used to repaint from
the top of the screen if desired. By default, any forward move-
ment causes scrolling.
-zn or --window=n or -n
Changes the default scrolling window size to n lines. The de-
fault 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 exam-
ple, 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 char-
acter. 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 speci-
fied 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 frac-
tion, 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-seek-
able (such as a pipe) and is large.
--follow-name
Normally, if the input file is renamed while an F command is exe-
cuting, less will continue to display the contents of the origi-
nal 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 cre-
ated with the same name as the original (now renamed) file), less
will display the contents of that new file.
--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 com-
mand has been issued from within less), or 1 (if the --header op-
tion 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, re-
gardless 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 dis-
played 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.
--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 op-
tion 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 re-
sized.
--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 sepa-
rated 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. 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 re-
porting, and on the Windows version of less.
--MOUSE
Like --mouse, except the direction scrolled on mouse wheel move-
ment is reversed.
--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 his-
tory list, the existing copy is removed from the history list be-
fore 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-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 un-
derscore 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 con-
trolled 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 immedi-
ately before a newline is deleted. This option overrides the -u
and -U options, so that display of carriage returns can be con-
trolled 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 options.
--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 ter-
minal 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 LESS-
BINFMT 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 dif-
ferent 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 be-
ginning of every search pattern. For example, setting --search-
options=W is the same as typing ^W at the beginning of every pat-
tern. 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 ef-
fect. 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 op-
tion 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 termi-
nal 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 de-
fault 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 argu-
ments. Any arguments following this are interpreted as file-
names. 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 op-
tion 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 begin-
ning, and +/xyz tells it to start at the first occurrence of
"xyz" in the file. As a special case, +<number> acts like +<num-
ber>g; that is, it starts the display at the specified line num-
ber (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 de-
scribed 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), cer-
tain 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 liter-
ally by preceding it with the "literal" character, either ^V or ^A. A
backslash itself may also be entered literally by entering two back-
slashes.
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 cur-
sor 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 be-
gins 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 match-
ing 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 com-
mand line is empty. If you have changed your line-kill character
in Unix to something other than ^U, that character is used in-
stead 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 sys-
less 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.
Previous 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 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 origi-
nal 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 replace-
ment filename, less uses the original file, as normal. The input pre-
processor 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 in-
clude 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 pro-
gram, 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 origi-
nal 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 "$1" in
*.Z) TEMPFILE=$(mktemp)
uncompress -c $1 >$TEMPFILE 2>/dev/null
if [ -s $TEMPFILE ]; then
echo $TEMPFILE
else
rm -f $TEMPFILE
fi
;;
esac
lessclose.sh:
#! /bin/sh
rm $2
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 da-
ta directly to less, rather than putting the data into a replacement
file. This avoids the need to decompress the entire file before start-
ing 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 replace-
ment 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 previ-
ous example scripts:
lesspipe.sh:
#! /bin/sh
case "$1" in
*.Z) uncompress -c $1 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 in-
terpreted as meaning there is no replacement, and the original file is
used. To avoid this, if LESSOPEN starts with two vertical bars, the ex-
it status of the script determines the behavior when the output is emp-
ty. If the output is empty and the exit status is zero, the empty out-
put is considered to be replacement text. If the output is empty and
the exit status is nonzero, the original file is used. For compatibili-
ty with previous versions of less, if LESSOPEN starts with only one ver-
tical 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 con-
sisting 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 bi-
nary.
iso8859
Selects an ISO 8859 character set. This is the same as ASCII,
except characters between 160 and 255 are treated as normal char-
acters.
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 envi-
ronment 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 in-
terface, less will use setlocale to determine the character set. setlo-
cale is controlled by setting the LANG or LC_CTYPE environment vari-
ables.
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 LESS-
BINFMT 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., unas-
signed 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 com-
plete 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 con-
trol characters, but if you are using a custom font with printable char-
acters 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 defini-
tions. Each character type definition consists of either one hexadeci-
mal 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 as-
cending 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 be-
low 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 speci-
fies 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 equivalent-
ly, 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 de-
fined). 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 con-
ditions. 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 charac-
ters (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, peri-
od, percent, and backslash) become literally part of the prompt. Any of
the special characters may be included in the prompt literally by pre-
ceding it with a backslash.
Some examples:
?f%f:Standard input.
This prompt prints the filename, if known; otherwise the string "Stan-
dard input".
?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
This prompt would print the filename, if known. The filename is fol-
lowed by the line number, if known, otherwise the percent if known, oth-
erwise 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 ex-
panded 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 invoca-
tion syntax, the LESSEDIT variable can be changed to modify this de-
fault.
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 SIGSTOP signal
tags use of tags files (-t)
The LESSSECURE_ALLOW environment variable can be set to a comma-separat-
ed list of names of features which are selectively enabled when LESSSE-
CURE 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 abbrevia-
tion 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", less behaves (mostly) in con-
formance 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 be-
haves as if the -e option were set. If the -e option is set, less be-
haves as if the -E option were set.
The -m option works differently. If the -m option is not set, the medi-
um 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 vari-
able 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:;[?!"'#%()*+ ".
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 glob-
al(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, com-
mands 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 dis-
played. 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_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, Win-
dows, 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 sec-
tion.
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) 1984-2024 Mark Nudelman
less is part of the GNU project and is free software. You can redis-
tribute it and/or modify it under the terms of either (1) the GNU Gener-
al 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 re-
ceived 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 FIT-
NESS 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 668: 06 Oct 2024 LESS(1)
Generated by dwww version 1.16 on Tue Dec 16 04:00:21 CET 2025.