NAME¶
less - opposite of more
SYNOPSIS¶
less -?
less --help
less -V
less --version
less [-[+]aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~]
[-b space] [-h lines] [-j line] [-k keyfile]
[-{oO} logfile] [-p pattern] [-P prompt] [-t
tag]
[-T tagsfile] [-x tab,...] [-y lines] [-[z]
lines]
[-# shift] [+[+]cmd] [--] [filename]...
(See the OPTIONS section for alternate option syntax with long option names.)
DESCRIPTION¶
Less is a program similar to
more (1), but it has many more
features.
Less does not have to read the entire input file before
starting, so with large input files it starts up faster than text editors like
vi (1).
Less uses termcap (or terminfo on some systems), so it
can run on a variety of terminals. There is even limited support for hardcopy
terminals. (On a hardcopy terminal, lines which should be printed at the top
of the screen are prefixed with a caret.)
Commands 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 literalization
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
displayed, even if N is more than the screen size.
- d or ^D
- Scroll forward N lines, default one half of the screen
size. If N is specified, it becomes the new default for subsequent d and u
commands.
- b or ^B or ESC-v
- Scroll backward N lines, default one window (see option -z
below). If N is more than the screen size, only the final screenful is
displayed.
- w
- Like ESC-v, but if N is specified, it becomes the new
window size.
- y or ^Y or ^P or k or ^K
- Scroll backward N lines, default 1. The entire N lines are
displayed, even if N is more than the screen size. Warning: some systems
use ^Y as a special job control character.
- u or ^U
- Scroll backward N lines, default one half of the screen
size. If N is specified, it becomes the new default for subsequent d and u
commands.
- ESC-) or RIGHTARROW
- Scroll horizontally right N characters, default half the
screen width (see the -# option). If a number N is specified, it becomes
the default for future RIGHTARROW and LEFTARROW commands. While the text
is scrolled, it acts as though the -S option (chop lines) were in
effect.
- ESC-( or LEFTARROW
- Scroll horizontally left N characters, default half the
screen width (see the -# option). If a number N is specified, it becomes
the default for future RIGHTARROW and LEFTARROW commands.
- r or ^R or ^L
- Repaint the screen.
- R
- Repaint the screen, discarding any buffered input. 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.)
- g or < or ESC-<
- Go to line N in the file, default 1 (beginning of file).
(Warning: this may be slow if N is large.)
- G or > or ESC->
- Go to line N in the file, default the end of the file.
(Warning: this may be slow if N is large, or if N is not specified and
standard input, rather than a file, is being read.)
- 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 top line,
a number N may be used to specify the N-th bracket on the line.
- (
- Like {, but applies to parentheses rather than curly
brackets.
- )
- Like }, but applies to parentheses rather than curly
brackets.
- [
- Like {, but applies to square brackets rather than curly
brackets.
- ]
- Like }, but applies to square brackets rather than curly
brackets.
- ESC-^F
- Followed by two characters, acts like {, but uses the two
characters as open and close brackets, respectively. For example,
"ESC ^F < >" could be used to go forward to the > which
matches the < in the top displayed line.
- ESC-^B
- Followed by two characters, acts like }, but uses the two
characters as open and close brackets, respectively. For example,
"ESC ^B < >" could be used to go backward to the <
which matches the > in the bottom displayed line.
- m
- Followed by any lowercase letter, marks the current
position with that letter.
- '
- (Single quote.) Followed by any lowercase letter, returns
to the position which was previously marked with that letter. Followed by
another single quote, returns to the position at which the last
"large" movement command was executed. Followed by a ^ or $,
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.
- /pattern
- Search forward in the file for the N-th line containing the
pattern. N defaults to 1. The pattern is a regular expression, as
recognized by the regular expression library supplied by your system. The
search starts at the first line displayed (but see the -a and -j options,
which change this).
Certain characters are special if entered at the beginning of the pattern;
they modify the type of search rather than become part of the
pattern:
- ^N or !
- Search for lines which do NOT match the pattern.
- ^E or *
- Search multiple files. That is, if the search reaches the
END of the current file without finding a match, the search continues in
the next file in the command line list.
- ^F or @
- Begin the search at the first line of the FIRST file in the
command line list, regardless of what is currently displayed on the screen
or the settings of the -a or -j options.
- ^K
- Highlight any text which matches the pattern on the current
screen, but don't move to the first match (KEEP current position).
- ^R
- Don't interpret regular expression metacharacters; that is,
do a simple textual comparison.
- ?pattern
- Search backward in the file for the N-th line containing
the pattern. The search starts at the line immediately before the top line
displayed.
Certain characters are special as in the / command:
- ^N or !
- Search for lines which do NOT match the pattern.
- ^E or *
- Search multiple files. That is, if the search reaches the
beginning of the current file without finding a match, the search
continues in the previous file in the command line list.
- ^F or @
- Begin the search at the last line of the last file in the
command line list, regardless of what is currently displayed on the screen
or the settings of the -a or -j options.
- ^K
- As in forward searches.
- ^R
- As in forward searches.
- ESC-/pattern
- Same as "/*".
- ESC-?pattern
- Same as "?*".
- n
- Repeat previous search, for N-th line containing the last
pattern. If the previous search was modified by ^N, the search is made for
the N-th line NOT containing the pattern. If the previous search was
modified by ^E, the search continues in the next (or previous) file if not
satisfied in the current file. If the previous search was modified by ^R,
the search is done without using regular expressions. 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.)
- &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.
Certain characters are special as in the / command:
- ^N or !
- Display only lines which do NOT match the pattern.
- ^R
- Don't interpret regular expression metacharacters; that is,
do a simple textual comparison.
- :e [filename]
- Examine a new file. If the filename is missing, the
"current" file (see the :n and :p commands below) from the list
of files in the command line is re-examined. A percent sign (%) in the
filename is replaced by the name of the current file. A pound sign (#) is
replaced by the name of the previously examined file. However, two
consecutive percent signs are simply replaced with a single percent sign.
This allows you to enter a filename that contains a percent sign in the
name. Similarly, two consecutive pound signs are replaced with a single
pound sign. The filename is inserted into the command line list of files
so that it can be seen by subsequent :n and :p commands. If the filename
consists of several files, they are all inserted into the list of files
and the first one is examined. If the filename contains one or more
spaces, the entire filename should be enclosed in double quotes (also see
the -" option).
- ^X^V or E
- Same as :e. Warning: some systems use ^V as a special
literalization character. On such systems, you may not be able to use
^V.
- :n
- Examine the next file (from the list of files given in the
command line). If a number N is specified, the N-th next file is
examined.
- :p
- Examine the previous file in the command line list. If a
number N is specified, the N-th previous file is examined.
- :x
- Examine the first file in the command line list. If a
number N is specified, the N-th file in the list is examined.
- :d
- Remove the current file from the list of files.
- t
- Go to the next tag, if there were more than one matches for
the current tag. See the -t option for more details about tags.
- T
- Go to the previous tag, if there were more than one matches
for the current tag.
- = or ^G or :f
- Prints some information about the file being viewed,
including its name and the line number and byte offset of the bottom line
being displayed. If possible, it also prints the length of the file, the
number of lines in the file and the percent of the file above the last
displayed line.
- -
- Followed by one of the command line option letters (see
OPTIONS below), this will change the setting of that option and print a
message describing the new setting. If a ^P (CONTROL-P) is entered
immediately after the dash, the setting of the option is changed but no
message is printed. If the option letter has a numeric value (such as -b
or -h), or a string value (such as -P or -t), a new value may be entered
after the option letter. If no new value is entered, a message describing
the current setting is printed and nothing is changed.
- --
- Like the - command, but takes a long option name (see
OPTIONS below) rather than a single option letter. 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 reset the option to its default setting and print a message
describing the new setting. (The "-+ X" command does the
same thing as "-+ X" on the command line.) This does not
work for string-valued options.
- --+
- Like the -+ command, but takes a long option name rather
than a single option letter.
- -!
- Followed by one of the command line option letters, this
will reset the option to the "opposite" of its default setting
and print a message describing the new setting. This does not work for
numeric or string-valued options.
- --!
- Like the -! command, but takes a long option name rather
than a single option letter.
- _
- (Underscore.) Followed by one of the command line option
letters, this will print a message describing the current setting of that
option. The setting of the option is not changed.
- __
- (Double underscore.) Like the _ (underscore) command, but
takes a long option name rather than a single option letter. You must
press ENTER or RETURN after typing the option name.
- +cmd
- Causes the specified cmd to be executed each time a new
file is examined. For example, +G causes less to initially display
each file starting at the end rather than the beginning.
- V
- Prints the version number of less being run.
- q or Q or :q or :Q or ZZ
- Exits less.
The following four commands may or may not be valid, depending on your
particular installation.
- v
- Invokes an editor to edit the current file being viewed.
The editor is taken from the environment variable VISUAL if defined, or
EDITOR if VISUAL is not defined, or defaults to "vi" if neither
VISUAL nor EDITOR is defined. See also the discussion of LESSEDIT under
the section on PROMPTS below.
- ! shell-command
- Invokes a shell to run the shell-command given. A percent
sign (%) in the command is replaced by the name of the current file. A
pound sign (#) is replaced by the name of the previously examined file.
"!!" repeats the last shell command. "!" with no shell
command simply invokes a shell. On Unix systems, the shell is taken from
the environment variable SHELL, or defaults to "sh". On MS-DOS
and OS/2 systems, the shell is the normal command processor.
- | <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 first line on the current screen and the position
marked by the letter. <m> may also be ^ or $ to indicate beginning
or end of file respectively. If <m> is . or newline, the current
screen is piped.
- s filename
- Save the input to a file. This only works if the input is a
pipe, not an ordinary file.
OPTIONS¶
Command line options are described below. Most options may be changed while
less is running, via the "-" command.
Most options may be given in one of two forms: either a dash followed by a
single letter, or two dashes followed by a long option name. A long option
name may be abbreviated as long as the abbreviation is unambiguous. For
example, --quit-at-eof may be abbreviated --quit, but not --qui, since both
--quit-at-eof and --quiet begin with --qui. Some long option names are in
uppercase, such as --QUIT-AT-EOF, as distinct from --quit-at-eof. Such option
names need only have their first letter capitalized; the remainder of the name
may be in either case. For example, --Quit-at-eof is equivalent to
--QUIT-AT-EOF.
Options are also taken from the environment variable "LESS". For
example, to avoid typing "less -options ..." each time
less
is invoked, you might tell
csh:
setenv LESS "-options"
or if you use
sh:
LESS="-options"; export LESS
On MS-DOS, you don't need the quotes, but you should replace any percent signs
in the options string by double percent signs.
The environment variable is parsed before the command line, so command line
options override the LESS environment variable. If an option appears in the
LESS variable, it can be reset to its default value on the command line by
beginning the command line option with "-+".
For options like -P or -D which take a following string, a dollar sign ($) must
be used to signal the end of the string. For example, to set two -D options on
MS-DOS, you must have a dollar sign between them, like this:
LESS="-Dn9.1$-Ds4.1"
- -? or --help
- This option displays a summary of the commands accepted by
less (the same as the h command). (Depending on how your shell
interprets the question mark, it may be necessary to quote the question
mark, thus: "-\?".)
- -a or --search-skip-screen
- By default, forward searches start at the top of the
displayed screen and backwards searches start at the bottom of the
displayed screen (except for repeated searches invoked by the n or N
commands, which start after or before the "target" line
respectively; see the -j option for more about the target line). The -a
option causes forward searches to instead start at the bottom of the
screen and backward searches to start at the top of the screen, thus
skipping all lines displayed on the screen.
- -A or --SEARCH-SKIP-SCREEN
- Causes all forward searches (not just non-repeated
searches) to start just after the target line, and all backward searches
to start just before the target line. Thus, forward searches will skip
part of the displayed screen (from the first line up to and including the
target line). Similarly backwards searches will skip the displayed screen
from the last line up to and including the target line. This was the
default behavior in less versions prior to 441.
- -bn or --buffers=n
- Specifies the amount of buffer space less will use
for each file, in units of kilobytes (1024 bytes). By default 64K of
buffer space is used for each file (unless the file is a pipe; see the -B
option). The -b option specifies instead that n kilobytes of buffer
space should be used for each file. If n is -1, buffer space is
unlimited; that is, the entire file can be read into memory.
- -B or --auto-buffers
- By default, when data is read from a pipe, buffers are
allocated automatically as needed. If a large amount of data is read from
the pipe, this can cause a large amount of memory to be allocated. The -B
option disables this automatic allocation of buffers for pipes, so that
only 64K (or the amount of space specified by the -b option) is used for
the pipe. Warning: use of -B can result in erroneous display, since only
the most recently viewed part of the piped data is kept in memory; any
earlier data is lost.
- -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
- [MS-DOS only] Sets the color of the text displayed.
x is a single character which selects the type of text whose color
is being set: n=normal, s=standout, d=bold, u=underlined, k=blink.
color is a pair of numbers separated by a period. The first number
selects the foreground color and the second selects the background color
of the text. A single number N is the same as N.M, where
M is the normal background color.
- -e or --quit-at-eof
- Causes less to automatically exit the second time it
reaches end-of-file. By default, the only way to exit less is via
the "q" command.
- -E or --QUIT-AT-EOF
- Causes less to automatically exit the first time it
reaches end-of-file.
- -f or --force
- Forces non-regular files to be opened. (A non-regular file
is a directory or a device special file.) Also suppresses the warning
message when a binary file is opened. By default, less will refuse
to open non-regular files. Note that some operating systems will not allow
directories to be read, even if -f is set.
- -F or --quit-if-one-screen
- Causes less to automatically exit if the entire file
can be displayed on the first screen.
- -g or --hilite-search
- Normally, less will highlight ALL strings which
match the last search command. The -g option changes this behavior to
highlight only the particular string which was found by the last search
command. This can cause less to run somewhat faster than the
default.
- -G or --HILITE-SEARCH
- The -G option suppresses all highlighting of strings found
by search commands.
- -hn or --max-back-scroll=n
- Specifies a maximum number of lines to scroll backward. If
it is necessary to scroll backward more than n lines, the screen is
repainted in a forward direction instead. (If the terminal does not have
the ability to scroll backward, -h0 is implied.)
- -i or --ignore-case
- Causes searches to ignore case; that is, uppercase and
lowercase are considered identical. This option is ignored if any
uppercase letters appear in the search pattern; in other words, if a
pattern contains uppercase letters, then that search does not ignore
case.
- -I or --IGNORE-CASE
- Like -i, but searches ignore case even if the pattern
contains uppercase letters.
- -jn or --jump-target=n
- Specifies a line on the screen where the "target"
line is to be positioned. The target line is the line specified by any
command to search for a pattern, jump to a line number, jump to a file
percentage or jump to a tag. The screen line may be specified by a number:
the top line on the screen is 1, the next is 2, and so on. The number may
be negative to specify a line relative to the bottom of the screen: the
bottom line on the screen is -1, the second to the bottom is -2, and so
on. Alternately, the screen line may be specified as a fraction of the
height of the screen, starting with a decimal point: .5 is in the middle
of the screen, .3 is three tenths down from the first line, and so on. If
the line is specified as a fraction, the actual line number is
recalculated if the terminal window is resized, so that the target line
remains at the specified fraction of the screen height. If any form of the
-j option is used, forward searches begin at the line immediately after
the target line, and 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.
- -J or --status-column
- Displays a status column at the left edge of the screen.
The status column shows the lines that matched the current search. The
status column is also used if the -w or -W option is in effect.
- -kfilename or --lesskey-file=filename
- Causes less to open and interpret the named file as
a lesskey (1) 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.
- -K or --quit-on-intr
- Causes less to exit immediately (with status 2) when
an interrupt character (usually ^C) is typed. Normally, an interrupt
character causes less to stop whatever it is doing and return to
its command prompt. Note that use of this option makes it impossible to
return to the command prompt from the "F" command.
- -L or --no-lessopen
- Ignore the LESSOPEN environment variable (see the INPUT
PREPROCESSOR section below). This option can be set from within
less, but it will apply only to files opened subsequently, not to
the file which is currently open.
- -m or --long-prompt
- Causes less to prompt verbosely (like more),
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.
- -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 option will
avoid this problem. Using line numbers means: the line number will be
displayed in the verbose prompt and in the = command, and the v command
will pass the current line number to the editor (see also the discussion
of LESSEDIT in PROMPTS below).
- -N or --LINE-NUMBERS
- Causes a line number to be displayed at the beginning of
each line in the display.
- -ofilename or --log-file=filename
- Causes less to copy its input to the named file as
it is being viewed. This applies only when the input file is a pipe, not
an ordinary file. If the file already exists, less will ask for
confirmation before overwriting it.
- -Ofilename or --LOG-FILE=filename
- The -O option is like -o, but it will overwrite an existing
file without asking for confirmation.
If no log file has been specified, the -o and -O options can be used from
within less to specify a log file. Without a file name, they will
simply report the name of the log file. The "s" command is
equivalent to specifying -o from within less.
- -ppattern or --pattern=pattern
- The -p option on the command line is equivalent to
specifying +/ pattern; that is, it tells less to start at
the first occurrence of pattern in the file.
- -Pprompt or --prompt=prompt
- Provides a way to tailor the three prompt styles to your
own preference. This option would normally be put in the LESS environment
variable, rather than being typed in with each less command. Such
an option must either be the last option in the LESS variable, or be
terminated by a dollar sign. -Ps followed by a string changes the default
(short) prompt to that string. -Pm changes the medium (-m) prompt. -PM
changes the long (-M) prompt. -Ph changes the prompt for the help screen.
-P= changes the message printed by the = command. -Pw changes the message
printed while waiting for data (in the F command). All prompt strings
consist of a sequence of letters and special escape sequences. See the
section on PROMPTS for more details.
- -q or --quiet or --silent
- Causes moderately "quiet" operation: the terminal
bell is not rung if an attempt is made to scroll past the end of the file
or before the beginning of the file. If the terminal has a "visual
bell", it is used instead. The bell will be rung on certain other
errors, such as typing an invalid character. The default is to ring the
terminal bell in all such cases.
- -Q or --QUIET or --SILENT
- Causes totally "quiet" operation: the terminal
bell is never rung.
- -r or --raw-control-chars
- Causes "raw" control characters to be displayed.
The default is to display control characters using the caret notation; for
example, a control-A (octal 001) is displayed as "^A". 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.
- -R or --RAW-CONTROL-CHARS
- Like -r, but only ANSI "color" escape sequences
are output in "raw" form. Unlike -r, the screen appearance is
maintained correctly in most cases. ANSI "color" escape
sequences are sequences of the form:
ESC [ ... m
where the "..." is zero or more color specification characters For
the purpose of keeping track of screen appearance, ANSI color escape
sequences are assumed to not move the cursor. 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
rather than folded. That is, the portion of a long line that does not fit
in the screen width is not shown. The default is to fold long lines; that
is, display the remainder on the next line.
- -ttag or --tag=tag
- The -t option, followed immediately by a TAG, will edit the
file containing that tag. For this to work, tag information must be
available; for example, there may be a file in the current directory
called "tags", which was previously built by ctags (1) or
an equivalent command. If the environment variable LESSGLOBALTAGS is set,
it is taken to be the name of a command compatible with global (1),
and that command is executed to find the tag. (See
http://www.gnu.org/software/global/global.html). The -t option may also be
specified from within less (using the - command) as a way of
examining a new file. The command ":t" is equivalent to
specifying -t from within less.
- -Ttagsfile or --tag-file=tagsfile
- Specifies a tags file to be used instead of
"tags".
- -u or --underline-special
- Causes backspaces and carriage returns to be treated as
printable characters; that is, they are sent to the terminal when they
appear in the input.
- -U or --UNDERLINE-SPECIAL
- Causes backspaces, tabs and carriage returns to be treated
as control characters; that is, they are handled as specified by the -r
option.
By default, if neither -u nor -U is given, backspaces which appear adjacent
to an underscore character are treated specially: the underlined text is
displayed using the terminal's hardware underlining capability. Also,
backspaces which appear between two identical characters are treated
specially: the overstruck text is printed using the terminal's hardware
boldface capability. Other backspaces are deleted, along with the
preceding character. Carriage returns immediately followed by a newline
are deleted. other carriage returns are handled as specified by the -r
option. Text which is overstruck or underlined can be searched for if
neither -u nor -U is in effect.
- -V or --version
- Displays the version number of less.
- -w or --hilite-unread
- Temporarily highlights the first "new" line after
a forward movement of a full page. The first "new" line is the
line immediately following the line previously at the bottom of the
screen. Also highlights the target line after a g or p command. The
highlight is removed at the next command which causes movement. The entire
line is highlighted, unless the -J option is in effect, in which case only
the status column is highlighted.
- -W or --HILITE-UNREAD
- Like -w, but temporarily highlights the first new line
after any forward movement command larger than one line.
- -xn,... or --tabs=n,...
- Sets tab stops. If only one n is specified, tab
stops are set at multiples of n. If multiple values separated by
commas are specified, tab stops are set at those positions, and then
continue with the same spacing as the last two. For example, -x9,17
will set tabs at positions 9, 17, 25, 33, etc. The default for n is
8.
- -X or --no-init
- Disables sending the termcap initialization and
deinitialization strings to the terminal. This is sometimes desirable if
the deinitialization string does something unnecessary, like clearing the
screen.
- -yn or --max-forw-scroll=n
- Specifies a maximum number of lines to scroll forward. If
it is necessary to scroll forward more than n lines, the screen is
repainted instead. The -c or -C option may be used to repaint from the top
of the screen if desired. By default, any forward movement causes
scrolling.
- -[z]n or --window=n
- Changes the default scrolling window size to n
lines. The default is one screenful. The z and w commands can also be used
to change the window size. The "z" may be omitted for
compatibility with some versions of more. If the number n is
negative, it indicates n lines less than the current screen size.
For example, if the screen is 24 lines, -z-4 sets the scrolling
window to 20 lines. If the screen is resized to 40 lines, the scrolling
window automatically changes to 36 lines.
- -"cc or --quotes=cc
- Changes the filename quoting character. This may be
necessary if you are trying to name a file which contains both spaces and
quote characters. Followed by a single character, this changes the quote
character to that character. Filenames containing a space should then be
surrounded by that character rather than by double quotes. Followed by two
characters, changes the open quote to the first character, and the close
quote to the second character. Filenames containing a space should then be
preceded by the open quote character and followed by the close quote
character. Note that even after the quote characters are changed, this
option remains -" (a dash followed by a double quote).
- -~ or --tilde
- Normally lines after end of file are displayed as a single
tilde (~). This option causes lines after end of file to be displayed as
blank lines.
- -# or --shift
- Specifies the default number of positions to scroll
horizontally in the RIGHTARROW and LEFTARROW commands. If the number
specified is zero, it sets the default number of positions to one half of
the screen width. Alternately, the number may be specified as a fraction
of the width of the screen, starting with a decimal point: .5 is half of
the screen width, .3 is three tenths of the screen width, and so on. If
the number is specified as a fraction, the actual number of scroll
positions is recalculated if the terminal window is resized, so that the
actual scroll remains at the specified fraction of the screen width.
- --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.
- --follow-name
- Normally, if the input file is renamed while an F command
is executing, less will continue to display the contents of the
original file despite its name change. If --follow-name is specified,
during an F command less will periodically attempt to reopen the
file by name. If the reopen succeeds and the file is a different file from
the original (which means that a new file has been created with the same
name as the original (now renamed) file), less will display the
contents of that new file.
- --
- A command line argument of "--" marks the end of
option arguments. Any arguments following this are interpreted as
filenames. This can be useful when viewing a file whose name begins with a
"-" or "+".
- +
- If a command line option begins with +, the
remainder of that option is taken to be an initial command to less.
For example, +G tells less to start at the end of the file rather
than the beginning, and +/xyz tells it to start at the first occurrence of
"xyz" in the file. As a special case, +<number> acts like
+<number>g; that is, it starts the display at the specified line
number (however, see the caveat under the "g" command above). If
the option starts with ++, the initial command applies to every file being
viewed, not just the first one. The + command described previously may
also be used to set (or change) an initial command for every file.
LINE EDITING¶
When entering command line at the bottom of the screen (for example, a filename
for the :e command, or the pattern for a search command), certain keys can be
used to manipulate the command line. Most commands have an alternate form in [
brackets ] which can be used if a key does not exist on a particular keyboard.
(Note that the forms beginning with ESC do not work in some MS-DOS and Windows
systems because ESC is the line erase character.) Any of these special keys
may be entered literally by preceding it with the "literal"
character, either ^V or ^A. A backslash itself may also be entered literally
by entering two backslashes.
- LEFTARROW [ ESC-h ]
- Move the cursor one space to the left.
- RIGHTARROW [ ESC-l ]
- Move the cursor one space to the right.
- ^LEFTARROW [ ESC-b or ESC-LEFTARROW ]
- (That is, CONTROL and LEFTARROW simultaneously.) Move the
cursor one word to the left.
- ^RIGHTARROW [ ESC-w or ESC-RIGHTARROW ]
- (That is, CONTROL and RIGHTARROW simultaneously.) Move the
cursor one word to the right.
- HOME [ ESC-0 ]
- Move the cursor to the beginning of the line.
- END [ ESC-$ ]
- Move the cursor to the end of the line.
- BACKSPACE
- Delete the character to the left of the cursor, or cancel
the command if the command line is empty.
- DELETE or [ ESC-x ]
- Delete the character under the cursor.
- ^BACKSPACE [ ESC-BACKSPACE ]
- (That is, CONTROL and BACKSPACE simultaneously.) Delete the
word to the left of the cursor.
- ^DELETE [ ESC-X or ESC-DELETE ]
- (That is, CONTROL and DELETE simultaneously.) Delete the
word under the cursor.
- UPARROW [ ESC-k ]
- Retrieve the previous command line.
- DOWNARROW [ ESC-j ]
- Retrieve the next command line.
- TAB
- Complete the partial filename to the left of the cursor. If
it matches more than one filename, the first match is entered into the
command line. Repeated TABs will cycle thru the other matching filenames.
If the completed filename is a directory, a "/" is appended to
the filename. (On MS-DOS systems, a "\" 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)
- Delete the entire command line, or cancel the command if
the command line is empty. If you have changed your line-kill character in
Unix to something other than ^U, that character is used instead of
^U.
- ^G
- Delete the entire command line and return to the main
prompt.
KEY BINDINGS¶
You may define your own
less commands by using the program
lesskey
(1) to create a lesskey file. This file specifies a set of command keys and an
action associated with each key. You may also use
lesskey to change the
line-editing keys (see LINE EDITING), and to set environment variables. If the
environment variable LESSKEY is set,
less uses that as the name of the
lesskey file. Otherwise,
less looks in a standard place for the lesskey
file: On Unix systems,
less looks for a lesskey file called
"$HOME/.less". On MS-DOS and Windows systems,
less looks for
a lesskey file called "$HOME/_less", and if it is not found there,
then looks for a lesskey file called "_less" in any directory
specified in the PATH environment variable. On OS/2 systems,
less looks
for a lesskey file called "$HOME/less.ini", and if it is not found,
then looks for a lesskey file called "less.ini" in any directory
specified in the INIT environment variable, and if it not found there, then
looks for a lesskey file called "less.ini" in any directory
specified in the PATH environment variable. See the
lesskey manual page
for more details.
A system-wide lesskey 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 LESSKEY_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/sysless. (However, if
less
was built with a different sysconf directory than /usr/local/etc, that
directory is where the sysless file is found.) On MS-DOS and Windows systems,
the system-wide lesskey file is c:\_sysless. On OS/2 systems, the system-wide
lesskey file is c:\sysless.ini.
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 original file is
opened; that is,
less will display the original filename as the name of
the current file.
An input preprocessor receives one command line argument, the original filename,
as entered by the user. It should create the replacement file, and when
finished, print the name of the replacement file to its standard output. If
the input preprocessor does not output a replacement filename,
less
uses the original file, as normal. The input preprocessor is not called when
viewing standard input. To set up an input preprocessor, set the LESSOPEN
environment variable to a command line which will invoke your input
preprocessor. This command line should include one occurrence of the string
"%s", which will be replaced by the filename when the input
preprocessor command is invoked.
When
less closes a file opened in such a way, it will call another
program, called the input postprocessor, which may perform any desired
clean-up action (such as deleting the replacement file created by LESSOPEN).
This program receives two command line arguments, the original filename as
entered by the user, and the name of the replacement file. To set up an input
postprocessor, set the LESSCLOSE environment variable to a command line which
will invoke your input postprocessor. It may include two occurrences of the
string "%s"; the first is replaced with the original name of the
file and the second with the name of the replacement file, which was output by
LESSOPEN.
For example, on many Unix systems, these two scripts will allow you to keep
files in compressed format, but still let
less view them directly:
lessopen.sh:
#! /bin/sh
case "$1" in
*.Z) uncompress - $1 >/tmp/less.$$ 2>/dev/null
if [ -s /tmp/less.$$ ]; then
echo /tmp/less.$$
else
rm -f /tmp/less.$$
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 data
directly to
less, rather than putting the data into a replacement file.
This avoids the need to decompress the entire file before starting to view it.
An input preprocessor that works this way is called an input pipe. An input
pipe, instead of writing the name of a replacement file on its standard
output, writes the entire contents of the replacement file on its standard
output. If the input pipe does not write any characters on its standard
output, then there is no replacement file and
less uses the original
file, as normal. To use an input pipe, make the first character in the
LESSOPEN environment variable a vertical bar (|) to signify that the input
preprocessor is an input pipe.
For example, on many Unix systems, this script will work like the previous
example scripts:
lesspipe.sh:
#! /bin/sh
case "$1" in
*.Z) uncompress -c $1 2>/dev/null
;;
esac
To use this script, put it where it can be executed and set
LESSOPEN="|lesspipe.sh %s". When an input pipe is used, a LESSCLOSE
postprocessor can be used, but it is usually not necessary since there is no
replacement file to clean up. In this case, the replacement file name passed
to the LESSCLOSE postprocessor is "-".
For compatibility with previous versions of
less, the input preprocessor
or pipe is not used if
less is viewing standard input. However, if the
first character of LESSOPEN is a dash (-), the input preprocessor is used on
standard input as well as other files. In this case, the dash is not
considered to be part of the preprocessor command. If standard input is being
viewed, the input preprocessor is passed a file name consisting of a single
dash. Similarly, if the first two characters of LESSOPEN are vertical bar and
dash (|-), the input pipe is used on standard input as well as other files.
Again, in this case the dash is not considered to be part of the input pipe
command.
NATIONAL CHARACTER SETS¶
There are three types of characters in the input file:
- normal characters
- can be displayed directly to the screen.
- control characters
- should not be displayed directly, but are expected to be
found in ordinary text files (such as backspace and tab).
- binary characters
- should not be displayed directly and are not expected to be
found in text files.
A "character set" is simply a description of which characters are to
be considered normal, control, and binary. The LESSCHARSET environment
variable may be used to select a character set. Possible values for
LESSCHARSET are:
- ascii
- BS, TAB, NL, CR, and formfeed are control characters, all
chars with values between 32 and 126 are normal, and all others are
binary.
- iso8859
- Selects an ISO 8859 character set. This is the same as
ASCII, except characters between 160 and 255 are treated as normal
characters.
- latin1
- Same as iso8859.
- latin9
- Same as iso8859.
- dos
- Selects a character set appropriate for MS-DOS.
- ebcdic
- Selects an EBCDIC character set.
- IBM-1047
- Selects an EBCDIC character set used by OS/390 Unix
Services. This is the EBCDIC analogue of latin1. You get similar results
by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US in your
environment.
- koi8-r
- Selects a Russian character set.
- next
- Selects a character set appropriate for NeXT
computers.
- utf-8
- Selects the UTF-8 encoding of the ISO 10646 character set.
UTF-8 is special in that it supports multi-byte characters in the input
file. It is the only character set that supports multi-byte
characters.
- windows
- Selects a character set appropriate for Microsoft Windows
(cp 1251).
In rare cases, it may be desired to tailor
less to use a character set
other than the ones definable by LESSCHARSET. In this case, the environment
variable LESSCHARDEF can be used to define a character set. It should be set
to a string where each character in the string represents one character in the
character set. The character "." is used for a normal character,
"c" for control, and "b" for binary. A decimal number may
be used for repetition. For example, "bccc4b." would mean character
0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are binary, and 8 is
normal. All characters after the last are taken to be the same as the last, so
characters 9 through 255 would be normal. (This is an example, and does not
necessarily represent any real character set.)
This table shows the value of LESSCHARDEF which is equivalent to each of the
possible values for LESSCHARSET:
ascii 8bcccbcc18b95.b
dos 8bcccbcc12bc5b95.b.
ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b
9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b.
IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc
191.b
iso8859 8bcccbcc18b95.33b.
koi8-r 8bcccbcc18b95.b128.
latin1 8bcccbcc18b95.33b.
next 8bcccbcc18b95.bb125.bb
If neither LESSCHARSET nor LESSCHARDEF is set, but any of the strings
"UTF-8", "UTF8", "utf-8" or "utf8" is
found in the LC_ALL, LC_CTYPE or LANG environment variables, then the default
character set is utf-8.
If that string is not found, but your system supports the
setlocale
interface,
less will use setlocale to determine the character set.
setlocale is controlled by setting the LANG or LC_CTYPE environment variables.
Finally, if the
setlocale interface is also not available, the default
character set is latin1.
Control and binary characters are displayed in standout (reverse video). Each
such character is displayed in caret notation if possible (e.g. ^A for
control-A). Caret notation is used only if inverting the 0100 bit results in a
normal printable character. Otherwise, the character is displayed as a hex
number in angle brackets. This format can be changed by setting the LESSBINFMT
environment variable. LESSBINFMT may begin with a "*" and one
character to select the display attribute: "*k" is blinking,
"*d" is bold, "*u" is underlined, "*s" is
standout, and "*n" is normal. If LESSBINFMT does not begin with a
"*", normal attribute is assumed. The remainder of LESSBINFMT is a
string which may include one printf-style escape sequence (a % followed by x,
X, o, d, etc.). For example, if LESSBINFMT is "*u[%x]", binary
characters are displayed in underlined hexadecimal surrounded by brackets. The
default if no LESSBINFMT is specified is "*s<%02X>". Warning:
the result of expanding the character via LESSBINFMT must be less than 31
characters.
When the character set is utf-8, the LESSUTFBINFMT environment variable acts
similarly to LESSBINFMT but it applies to Unicode code points that were
successfully decoded but are unsuitable for display (e.g., unassigned code
points). Its default value is "<U+%04lX>". Note that
LESSUTFBINFMT and LESSBINFMT share their display attribute setting
("*x") so specifying one will affect both; LESSUTFBINFMT is read
after LESSBINFMT so its setting, if any, will have priority. Problematic
octets in a UTF-8 file (octets of a truncated sequence, octets of a complete
but non-shortest form sequence, illegal octets, and stray trailing octets) are
displayed individually using LESSBINFMT so as to facilitate diagnostic of how
the UTF-8 file is ill-formed.
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:
- %bX
- Replaced by the byte offset into the current input file.
The b is followed by a single character (shown as X above) which
specifies the line whose byte offset is to be used. If the character is a
"t", the byte offset of the top line in the display is used, an
"m" means use the middle line, a "b" means use the
bottom line, a "B" means use the line just after the bottom
line, and a "j" means use the "target" line, as
specified by the -j option.
- %B
- Replaced by the size of the current input file.
- %c
- Replaced by the column number of the text appearing in the
first column of the screen.
- %dX
- Replaced by the page number of a line in the input file.
The line to be used is determined by the X, as with the %b
option.
- %D
- Replaced by the number of pages in the input file, or
equivalently, the page number of the last line in the input file.
- %E
- Replaced by the name of the editor (from the VISUAL
environment variable, or the EDITOR environment variable if VISUAL is not
defined). See the discussion of the LESSEDIT feature below.
- %f
- Replaced by the name of the current input file.
- %F
- Replaced by the last component of the name of the current
input file.
- %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.
- %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.
- %x
- Replaced by the name of the next input file in the
list.
If any item is unknown (for example, the file size if input is a pipe), a
question mark is printed instead.
The format of the prompt string can be changed depending on certain conditions.
A question mark followed by a single character acts like an "IF":
depending on the following character, a condition is evaluated. If the
condition is true, any characters following the question mark and condition
character, up to a period, are included in the prompt. If the condition is
false, such characters are not included. A colon appearing between the
question mark and the period can be used to establish an "ELSE": any
characters between the colon and the period are included in the string if and
only if the IF condition is false. Condition characters (which follow a
question mark) may be:
- ?a
- True if any characters have been included in the prompt so
far.
- ?bX
- True if the byte offset of the specified line is
known.
- ?B
- True if the size of current input file is known.
- ?c
- True if the text is horizontally shifted (%c is not
zero).
- ?dX
- True if the page number of the specified line is
known.
- ?e
- True if at end-of-file.
- ?f
- True if there is an input filename (that is, if input is
not a pipe).
- ?lX
- True if the line number of the specified line is
known.
- ?L
- True if the line number of the last line in the file is
known.
- ?m
- True if there is more than one input file.
- ?n
- True if this is the first prompt in a new input file.
- ?pX
- True if the percent into the current input file, based on
byte offsets, of the specified line is known.
- ?PX
- True if the percent into the current input file, based on
line numbers, of the specified line is known.
- ?s
- Same as "?B".
- ?x
- True if there is a next input file (that is, if the current
input file is not the last one).
Any characters other than the special ones (question mark, colon, period,
percent, and backslash) become literally part of the prompt. Any of the
special characters may be included in the prompt literally by preceding it
with a backslash.
Some examples:
?f%f:Standard input.
This prompt prints the filename, if known; otherwise the string "Standard
input".
?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-...
This prompt would print the filename, if known. The filename is followed by the
line number, if known, otherwise the percent if known, otherwise the byte
offset if known. Otherwise, a dash is printed. Notice how each question mark
has a matching period, and how the % after the %pt is included literally by
escaping it with a backslash.
?n?f%f .?m(file %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(file %i of %m) ..?e(END) ?x- Next\: %x.:
?pB%pB\%:byte %bB?s/%s...%t
?f%f .?n?m(file %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(file %i of %m) .?ltlines %lt-%lb?L/%L. .
byte %bB?s/%s. ?e(END) :?pB%pB\%..%t
The prompt expansion features are also used for another purpose: if an
environment variable LESSEDIT is defined, it is used as the command to be
executed when the v command is invoked. The LESSEDIT string is expanded in the
same way as the prompt strings. The default value for LESSEDIT is:
%E ?lm+%lm. %f
Note that this expands to the editor name, followed by a + and the line number,
followed by the file name. If your editor does not accept the
"+linenumber" syntax, or has other differences in invocation syntax,
the LESSEDIT variable can be changed to modify this default.
SECURITY¶
When the environment variable LESSSECURE is set to 1,
less runs in a
"secure" mode. This means these features are disabled:
- !
- the shell command
- |
- the pipe command
- :e
- the examine command.
- v
- the editing command
- s -o
- log files
- -k
- use of lesskey files
- -t
- use of tags files
-
- metacharacters in filenames, such as *
-
- filename completion (TAB, ^L)
Less can also be compiled to be permanently in "secure" mode.
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 conformance with the POSIX "more" command specification. In this
mode, less behaves differently in these ways:
The -e option works differently. If the -e option is not set,
less
behaves as if the -E option were set. If the -e option is set,
less
behaves as if the -e and -F options were set.
The -m option works differently. If the -m option is not set, the medium prompt
is used, and it is prefixed with the string "--More--". If the -m
option is set, the short prompt is used.
The -n option acts like the -z option. The normal behavior of the -n option is
unavailable in this mode.
The parameter to the -p option is taken to be a
less command rather than
a search pattern.
The LESS environment variable is ignored, and the MORE environment variable is
used in its place.
ENVIRONMENT VARIABLES¶
Environment variables may be specified either in the system environment as
usual, or in a
lesskey (1) file. If environment variables are defined
in more than one place, variables defined in a local lesskey file take
precedence over variables defined in the system environment, which take
precedence over variables defined in the system-wide lesskey file.
- COLUMNS
- Sets the number of columns on the screen. Takes precedence
over the number of columns specified by the TERM variable. (But if you
have a windowing system which supports TIOCGWINSZ or WIOCGETD, the window
system's idea of the screen size takes precedence over the LINES and
COLUMNS environment variables.)
- EDITOR
- The name of the editor (used for the v command).
- HOME
- Name of the user's home directory (used to find a lesskey
file on Unix and OS/2 systems).
- HOMEDRIVE, HOMEPATH
- Concatenation of the HOMEDRIVE and HOMEPATH environment
variables is the name of the user's home directory if the HOME variable is
not set (only in the Windows version).
- INIT
- Name of the user's init directory (used to find a lesskey
file on OS/2 systems).
- LANG
- Language for determining the character set.
- LC_CTYPE
- Language for determining the character set.
- LESS
- Options which are passed to less automatically.
- LESSANSIENDCHARS
- Characters which may end an ANSI color escape sequence
(default "m").
- LESSANSIMIDCHARS
- Characters which may appear between the ESC character and
the end character in an ANSI color escape sequence (default
"0123456789;[?!"'#%()*+ ".
- LESSBINFMT
- Format for displaying non-printable, non-control
characters.
- LESSCHARDEF
- Defines a character set.
- LESSCHARSET
- Selects a predefined character set.
- LESSCLOSE
- Command line to invoke the (optional)
input-postprocessor.
- LESSECHO
- Name of the lessecho program (default
"lessecho"). The lessecho program is needed to expand
metacharacters, such as * and ?, in filenames on Unix systems.
- LESSEDIT
- Editor prototype string (used for the v command). See
discussion under PROMPTS.
- LESSGLOBALTAGS
- Name of the command used by the -t option to find global
tags. Normally should be set to "global" if your system has the
global (1) command. If not set, global tags are not used.
- LESSHISTFILE
- Name of the history file used to remember search commands
and shell commands between invocations of less. If set to
"-" or "/dev/null", a history file is not used. The
default is "$HOME/.lesshst" on Unix systems,
"$HOME/_lesshst" on DOS and Windows systems, or
"$HOME/lesshst.ini" or "$INIT/lesshst.ini" on OS/2
systems.
- LESSHISTSIZE
- The maximum number of commands to save in the history file.
The default is 100.
- LESSKEY
- Name of the default lesskey(1) file.
- LESSKEY_SYSTEM
- Name of the default system-wide lesskey(1) file.
- LESSMETACHARS
- List of characters which are considered
"metacharacters" by the shell.
- LESSMETAESCAPE
- Prefix which less will add before each metacharacter in a
command sent to the shell. If LESSMETAESCAPE is an empty string, commands
containing metacharacters will not be passed to the shell.
- LESSOPEN
- Command line to invoke the (optional)
input-preprocessor.
- LESSSECURE
- Runs less in "secure" mode. See discussion under
SECURITY.
- LESSSEPARATOR
- String to be appended to a directory name in filename
completion.
- LESSUTFBINFMT
- Format for displaying non-printable Unicode code
points.
- LESS_IS_MORE
- Emulate the more (1) command.
- 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.)
- PATH
- User's search path (used to find a lesskey file on MS-DOS
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).
SEE ALSO¶
lesskey(1)
COPYRIGHT¶
Copyright (C) 1984-2011 Mark Nudelman
less is part of the GNU project and is free software. You can redistribute it
and/or modify it under the terms of either (1) the GNU General Public License
as published by the Free Software Foundation; or (2) the Less License. See the
file README in the less distribution for more details regarding
redistribution. You should have received a copy of the GNU General Public
License along with the source for less; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place, Suite 330, Boston, MA
02111-1307, USA. You should also have received a copy of the Less License; see
the file LICENSE.
less is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
AUTHOR¶
Mark Nudelman <markn@greenwoodsoftware.com>
Send bug reports or comments to the above address or to bug-less@gnu.org.
See
http://www.greenwoodsoftware.com/less/bugs.html for the latest list of known
bugs in less.
For more information, see the less homepage at
http://www.greenwoodsoftware.com/less.