--- name: "less" section: "1" platform: "linux" package: "less" version: "1:710-1" release: "Arch Linux 2026-11-01" platforms: ["linux", "freebsd", "openbsd", "macos"] url: "https://new.carta.tech/less" --- # less(1) display the contents of a file in a terminal ## NAME less - display the contents of a file in a terminal ## SYNOPSIS **less** \[**-**\[**+**\] **aABcCdeEfFgGiIJKLmMnNqQrRsSuUVwWX~**\] \[**-b** *size*\] \[**-D** *color*\] \[**-h** *lines*\] \[**-j** *line*\] \[**-k** *key-file*\] \[**-**{**o**\|**O** } *log-file*\] \[**-p** *pattern*\] \[**-P** *prompt*\] \[**-t** *tag*\] \[**-T** *tags-file*\] \[**-x** *tab*\[{ **,***tab* }...\]\] \[**-y** *lines*\] \[**-z** *lines*\] \[**-** *lines*\] \[**-"***cc*\] \[**-#** *shift*\] \[**+** *less-command*\] \[**--**\] \[*file* ...\] **less -?**\ **less --help** **less -V**\ **less --version** **(See the OPTIONS section for alternate option syntax with long option names.)** ## DESCRIPTION **Less** **is a program similar to** [**more**(1)](/more/1.md), **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)](/vi/1.md). **Less** **uses termcap (or terminfo on some systems),** **so it can run on a variety of terminals.** **There is even limited support for hardcopy terminals.** **(On a hardcopy terminal, lines which should be printed at the top** **of the screen are prefixed with a caret.)** ## COMMANDS **Commands are based on both** **more** **and** **vi**. **Commands may be preceded by a decimal number,** **called N in the descriptions below.** **The number is used by some commands, as indicated.** **In the following descriptions, ^X means control-X.** **ESC stands for the ESCAPE key; for example ESC-v means the** **two character sequence "ESCAPE", then "v".** - h or H **Help: display a summary of these commands.** **If you forget all the other commands, remember this one.** - SPACE or ^V or f or ^F **Scroll forward N lines, default one window (see option** **-z** **below).** **If N is more than the screen size, only the final screenful is displayed.** **Warning: some systems use ^V as a special literalization character.** - z **Like SPACE, but if N is specified, it becomes the new window size.** - ENTER or RETURN or ^N or e or ^E or j or ^J **Scroll forward N lines, default 1.** **The entire N lines are displayed, even if N is more than the screen size.** - d or ^D **Scroll forward N lines, default one half of the screen size.** **If N is specified, it becomes the new default for** **subsequent d and u commands.** - b or ^B or ESC-v **Scroll backward N lines, default one window (see option** **-z** **below).** **If N is more than the screen size, only the final screenful is displayed.** - w **Like ESC-v, but if N is specified, it becomes the new window size.** - y or ^Y or ^P or k or ^K **Scroll backward N lines, default 1.** **The entire N lines are displayed, even if N is more than the screen size.** **Warning: some systems use ^Y as a special job control character.** - u or ^U **Scroll backward N lines, default one half of the screen size.** **If N is specified, it becomes the new default for** **subsequent d and u commands.** - J **Like j, but continues to scroll beyond the end of the file.** - K or Y **Like k, but continues to scroll beyond the beginning of the file.** - ESC-SPACE **Like SPACE, but scrolls a full screenful,** **even if it reaches the end of the file.** - ESC-b **Like b, but scrolls a full screenful,** **even if it reaches the beginning of the file.** - ESC-j **Scroll forward N file lines, default 1.** **A file line is a complete line in the file, terminated by a newline.** - ESC-k **Scroll backwards N file lines, default 1.** - ESC-) or RIGHTARROW **Scroll horizontally right N characters, default half the screen width** **(see the** **-#** **option).** **If a number N is specified, it becomes the default for future RIGHTARROW** **and LEFTARROW commands.** **While the text is scrolled, it acts as though the** **-S** **option** **(chop lines) were in effect.** - ESC-\] or ESC-RIGHTARROW **Scroll horizontally right N characters like RIGHTARROW,** **but stop scrolling when the last (rightmost) character on the** **displayed screen becomes visible at the right margin.** - ESC-( or LEFTARROW **Scroll horizontally left N characters, default half the screen width** **(see the** **-#** **option).** **If a number N is specified, it becomes the default for future RIGHTARROW** **and LEFTARROW commands.** - ESC-} or ^RIGHTARROW or SHIFT-RIGHTARROW **Scroll horizontally right to show the end of the longest displayed line.** - ESC-{ or ^LEFTARROW or SHIFT-LEFTARROW **Scroll horizontally left back to the first column.** - ^END or SHIFT-END **Go to line N in the file, default the end of the file, and** **scroll horizontally right to show the end of the longest displayed line.** - ^HOME or SHIFT-HOME **Go to line N in the file, default 1 (beginning of file),** **and scroll horizontally left back to the first column.** - r or ^R or ^L **Repaint the screen.** - R **Repaint the screen, discarding any buffered input.** **That is, reload the current file.** **Useful if the file is changing while it is being viewed.** - F **Scroll forward, and keep trying to read when the** **end of file is reached.** **Normally this command would be used when already at the end of the file.** **It is a way to monitor the tail of a file which is growing** **while it is being viewed.** **(The behavior is similar to the "tail -f" command.)** **To stop waiting for more data, enter the interrupt character (usually ^C).** **On systems which support** [**poll**(2)](/poll/2.md) **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 each time a line is found which matches** **the last search pattern, the terminal bell is rung.** - 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-\< or HOME **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-\> or END **Go to line N in the file, default the end of the file.** **(Warning: this may be slow if N is large,** **or if N is not specified and** **standard input, rather than a file, is being read.)** - ESC-G **Same as G, except if no number N is specified and the input is standard input,** **goes to the last line which is currently buffered.** - p or % **Go to a position N percent into the file.** **N should be between 0 and 100, and may contain a decimal point.** - P **Go to the line containing byte offset N in the file.** - { **If a left curly bracket appears in the top line displayed** **on the screen,** **the { command will go to the matching right curly bracket.** **The matching right curly bracket is positioned on the bottom** **line of the screen.** **If there is more than one left curly bracket on the top line,** **a number N may be used to specify the N-th bracket on the line.** - } **If a right curly bracket appears in the bottom line displayed** **on the screen,** **the } command will go to the matching left curly bracket.** **The matching left curly bracket is positioned on the top** **line of the screen.** **If there is more than one right curly bracket on the bottom line,** **a number N may be used to specify the N-th bracket on the line.** - ( **Like {, but applies to parentheses rather than curly brackets.** - ) **Like }, but applies to parentheses rather than curly brackets.** - \[ **Like {, but applies to square brackets rather than curly brackets.** - \] **Like }, but applies to square brackets rather than curly brackets.** - ESC-^F **Followed by two characters,** **acts like {, but uses the two characters as open and close brackets,** **respectively.** **For example, "ESC ^F \< \>" could be used to** **go forward to the \> which matches the \< in the top displayed line.** - ESC-^B **Followed by two characters,** **acts like }, but uses the two characters as open and close brackets,** **respectively.** **For example, "ESC ^B \< \>" could be used to** **go backward to the \< which matches the \> in the bottom displayed line.** - m **Followed by any lowercase or uppercase letter,** **marks the first displayed line with that letter.** **If a number N is given, line number N is marked instead.** **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.** **If a number N is given, line number N is marked instead.** - ' **(Single quote.)** **Followed by any lowercase or uppercase letter, returns to the position which** **was previously marked with that letter.** **Followed by another single quote, returns to the position at** **which the last "large" movement command was executed.** **Followed by a ^ or $, jumps to the beginning or end of the** **file respectively.** **If a number N is given, the marked line is placed on the N-th line** **on the screen.** **Otherwise, it is placed on the same line that it was on when it was marked** **(the first line on the screen if marked via the** **m** **command, the last line on the screen if marked via the** **M** **command, or the line that was clicked if marked via the mouse).** **Marks are preserved when a new file is examined within a single invocation of** **less**, **so the ' command can be used to switch between input files.** **The** **--save-marks** **option causes marks to be preserved across different invocations of** **less**. - ^X^X **Same as single quote.** - ESC-m **Followed by any lowercase or uppercase letter,** **clears the mark identified by that letter.** - /*pattern* **Search forward in the file for the N-th line containing the pattern.** **N defaults to 1.** **The pattern is a regular expression, as recognized by** **the regular expression library supplied by your system.** **By default, searching is case-sensitive (uppercase and lowercase** **are considered different); the** **-i** **option can be used to change this.** **The search starts at the first line displayed** **(but see the** **-a** **and** **-j** **options, which change this).** - **Certain characters are special** **if entered at the beginning of the pattern;** **they modify the type of search rather than become part of the pattern:** - ^N or ! **Search for lines which do NOT match the pattern.** - ^E or \* **Search multiple files.** **That is, if the search reaches the END of the current file** **without finding a match,** **the search continues in the next file in the command line list.** - ^F or @ **Begin the search at the first line of the FIRST file** **in the command line list,** **regardless of what is currently displayed on the screen** **or the settings of the** **-a** **or** **-j** **options.** - ^K **Highlight any text which matches the pattern on the current screen,** **but don't move to the first match (KEEP current position).** - ^R **Don't interpret regular expression metacharacters;** **that is, do a simple textual comparison.** - ^S **Followed by a digit N between 1 and 5.** **Only text which has a non-empty match for the N-th parenthesized SUB-PATTERN** **will be considered to match the pattern.** **For example, searching for "(abc)\|(def)" modified with ^S1** **would search for instances of "abc", but would highlight** **instances of both "abc" and "def".** **(Supported only if** **less** **is built with one of the regular expression libraries** **posix**, **pcre**, or **pcre2**.) **Multiple ^S modifiers can be specified,** **to match more than one sub-pattern.** - ^W **WRAP around the current file.** **That is, if the search reaches the end of the current file** **without finding a match, the search continues from the first line of the** **current file up to the line where it started.** **If the ^W modifier is set, the ^E modifier is ignored.** - ^L **The next character is taken literally; that is, it becomes part of the pattern** **even if it is one of the above search modifier characters.** - ?*pattern* **Search backward in the file for the N-th line containing the pattern.** **The search starts at the last line displayed** **(but see the** **-a** **and** **-j** **options, which change this).** - **Certain characters are special as in the / command:** - ^N or ! **Search for lines which do NOT match the pattern.** - ^E or \* **Search multiple files.** **That is, if the search reaches the beginning of the current file** **without finding a match,** **the search continues in the previous file in the command line list.** - ^F or @ **Begin the search at the last line of the last file** **in the command line list,** **regardless of what is currently displayed on the screen** **or the settings of the** **-a** **or** **-j** **options.** - ^K **As in forward searches.** - ^R **As in forward searches.** - ^S **As in forward searches.** - ^W **WRAP around the current file.** **That is, if the search reaches the beginning of the current file** **without finding a match, the search continues from the last line of the** **current file up to the line where it started.** - ^L **As in forward searches.** - ESC-/*pattern* **Same as "/\*".** - ESC-?*pattern* **Same as "?\*".** - n **Repeat previous search, for N-th line containing the last pattern.** **If the previous search was modified by ^N, the search is made for the** **N-th line NOT containing the pattern.** **If the previous search was modified by ^E, the search continues** **in the next (or previous) file if not satisfied in the current file.** **If the previous search was modified by ^R, the search is done** **without using regular expressions.** **If the previous search was modified by ^W, the search wraps at** **the end (or beginning) of the file.** **There is no effect if the previous search was modified by ^F or ^K.** - N **Repeat previous search, but in the reverse direction.** - ESC-n **Repeat previous search, but crossing file boundaries.** **The effect is as if the previous search were modified by \*.** - ESC-N **Repeat previous search, but in the reverse direction** **and crossing file boundaries.** - ESC-u **Undo search highlighting.** **Turn off highlighting of strings matching the current search pattern.** **If highlighting is already off because of a previous ESC-u command,** **turn highlighting back on.** **Any search command will also turn highlighting back on.** **Also unselects any OSC 8 hyperlink that is currently selected.** **(Highlighting can also be disabled by toggling the** **-G** **option;** **in that case search commands do not turn highlighting back on.)** - ESC-U **Like ESC-u but also clears the saved search pattern.** **If the status column is enabled via the** **-J** **option,** **this clears all search matches marked in the status column.** - &*pattern* **Display only lines which match the pattern;** **lines which do not match the pattern are hidden.** **If pattern is empty (if you type & immediately followed by ENTER),** **any filtering is turned off, and all lines are displayed.** **While filtering is in effect, an ampersand is displayed at the** **beginning of the prompt,** **as a reminder that some lines in the file may be hidden.** **Multiple & commands may be entered, in which case only lines** **which match all of the patterns will be displayed.** - **Certain characters are special as in the / command:** - ^N or ! **Display only lines which do NOT match the pattern.** - ^R **Don't interpret regular expression metacharacters;** **that is, do a simple textual comparison.** - :e \[*filename*\] **Examine a new file.** **If the filename is missing, the "current" file (see the :n and :p commands** **below) from the list of files in the command line is re-examined.** **A percent sign (%) in the filename is replaced by the** **shell-escaped name of the current file.** **A pound sign (#) is replaced by the shell-escaped 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).** **Any shell metacharacters in the filename, such as "\*" and "?", are** **expanded by the shell named in the SHELL environment variable.** **(Note that some shells may execute external programs if** **certain metacharacters are used, such as backticks or dollar signs.)** - ^X^V or E **Same as :e.** **Warning: some systems use ^V as a special literalization character.** **On such systems, you may not be able to use ^V.** - :n **Examine the next file (from the list of files given in the command line).** **If a number N is specified, the N-th next file is examined.** - :p **Examine the previous file in the command line list.** **If a number N is specified, the N-th previous file is examined.** - :x **Examine the first file in the command line list.** **If a number N is specified, the N-th file in the list is examined.** - :d **Remove the current file from the list of files.** - t **Go to the next tag, if there were more than one matches for the current tag.** **See the** **-t** **option for more details about tags.** - T **Go to the previous tag, if there were more than one matches for the current tag.** - ^O^N or ^On **Search forward in the file for the N-th next OSC 8 hyperlink.** - ^O^P or ^Op **Search backward in the file for the N-th previous OSC 8 hyperlink.** - ^O^L or ^Ol **Jump to the currently selected OSC 8 hyperlink.** - \= or ^G or :f **Prints some information about the file being viewed,** **including its name** **and the line number and byte offset of the bottom line being displayed.** **If possible, it also prints the length of the file,** **the number of lines in the file** **and the percent of the file above the last displayed line.** - \- **Followed by one of the command line option letters** **(see “OPTIONS” below),** **this will change the setting of that option** **and print a message describing the new setting.** **If a ^P (CONTROL-P) is entered immediately after the dash,** **the setting of the option is changed but no message is printed.** **If the option letter has a numeric value (such as** **-b** **or** **-h**), **or a string value (such as** **-P** **or** **-t**), **a new value may be entered after the option letter.** **If no new value is entered, a message describing** **the current setting is printed and nothing is changed.** - \-- **Like the - command, but takes a long option name** **(see “OPTIONS” below),** **rather than a single option letter.** **Press ENTER or RETURN after typing the option name to change it.** **You can enter just the beginning of an option name,** **then press TAB to find all option names which begin with that string.** **A ^P immediately after the second dash suppresses printing of a** **message describing the new setting, as in the - command.** - \-+ **Followed by one of the command line option letters** **this will reset the option to its default setting** **and print a message describing the new setting.** **(The "-+***X***" command does the same thing** **as** "**-+X**" **on the command line.)** **This does not work for string-valued options.** - \--+ **Like the -+ command, but takes a long option name** **rather than a single option letter.** - \-! **Followed by one of the command line option letters,** **this will reset the option to the "opposite" of its default setting** **and print a message describing the new setting.** **This does not work for numeric or string-valued options.** - \--! **Like the -! command, but takes a long option name** **rather than a single option letter.** - \_ **(Underscore.)** **Followed by one of the command line option letters,** **this will print a message describing the current setting of that option.** **The setting of the option is not changed.** - \_\_ **(Double underscore.)** **Like the \_ (underscore) command, but takes a long option name** **rather than a single option letter.** **You must press ENTER or RETURN after typing the option name.** - \+*cmd* **Causes the specified cmd to be executed each time a new file is examined.** **For example, +G causes** **less** **to initially display each file starting at the end** **rather than the beginning.** - V **Prints the version number of** **less** **being run.** - q or Q or :q or :Q or ZZ **Exits** **less**. **The following** **seven** **commands may or may not be valid, depending on your particular installation.** - v **Invokes an editor to edit the current file being viewed.** **The editor is taken from the environment variable VISUAL if defined,** **or EDITOR if VISUAL is not defined,** **or defaults to "vi" if neither VISUAL nor EDITOR is defined.** **See also the discussion of LESSEDIT under the section on PROMPTS below.** - ! *shell-command* **Invokes a shell to run the shell-command given.** **A percent sign (%) in the command is replaced by the name of the** **current file.** **Two consecutive percent signs (%%) are replaced with a single percent sign.** **A pound sign (#) is replaced by the name of the previously examined file.** **Two consecutive pound signs (##) are replaced with a single pound sign.** **"!!" repeats the last shell command.** **"!" with no shell command invokes an interactive shell.** **If a ^P (CONTROL-P) is entered immediately after the !,** **no "done" message is printed after the shell command is executed.** **On Unix systems, the shell is taken from the environment variable SHELL,** **or defaults to "sh".** **On MS-DOS, Windows, and OS/2 systems, the shell is the normal command processor.** - \# *shell-command* **Similar to the "!" command,** **except that the command is expanded in the same way as prompt strings.** **For example, the name of the current file would be given as "%f".** - \| \<*m*\> *shell-command* **\ represents any mark character.** **Pipes a section of the input file to the given shell command.** **If the marked line is before the top line of the current screen,** **the section to be piped is between the marked line and the bottom line** **of the current screen, inclusive.** **Otherwise (if the marked line is the top line of the current screen** **or after it) the section of the file to be piped is between the top line** **of the current screen and the marked line, inclusive.** **\ may also be "^" or "$" to indicate beginning or end of file respectively.** **If \ is "." or newline, the currently displayed screen is piped.** **You can type ^N in place of \ in order to enter** **a line number instead of a mark letter.** **If a ^P (CONTROL-P) is entered at the start of the shell command,** **no "done" message is printed after the shell command is executed.** - \|\| \<*m1*\> \<*m2*\> *shell-command* **Like "\|", pipes a section of the input file to the given shell command.** **The section of the file to be piped is between the two lines marked** **with \ and \, inclusive.** **The line marked by \ may be either before or after the line marked by \ in the file.** **Either mark may be "^" or "$" to indicate beginning or end of file respectively.** **":" or newline indicates the first line displayed on the screen,** **and ";" indicates the last line displayed on the screen.** **You can type ^N in place of either \ or \ in order to enter** **a line number instead of a mark letter.** - s *filename* **Save the input to a file.** **This works only if the input is a pipe, not an ordinary file.** - ^O^O **Run a shell command to open the URI in the current OSC 8 hyperlink,** **selected by a previous ^O^N or ^O^P command.** **The shell command is given by the environment variable** **named "LESS\_OSC8\_OPEN\_xxx"** **where "xxx" is the scheme from the URI (the part before the first colon),** **converted to lowercase.** **If there is no colon in the URI, the environment variable** **LESS\_OSC8\_OPEN\_NONE is used.** **The URI from the hyperlink is then shell-escaped and appended to the** **value of the environment variable after a space,** **and the resulting string is executed as a shell command.** **For example, if you wish to open https links by invoking a program** **called "mybrowser" with a "--new-window" option, you could set** ``` LESS_OSC8_OPEN_https="mybrowser --new-window" ``` **If the handler command begins with "-",** **the command is not displayed before it is executed.** **If the handler command begins with ^P (CONTROL-P),** **the "link done" message is not displayed after it is executed.** **If the handler command begins with ^P followed by "-",** **neither the command nor the "link done" message is displayed.** **If you attempt to open a link with the "xxx" scheme and the** **LESS\_OSC8\_OPEN\_xxx variable is not set,** **the variable LESS\_OSC8\_OPEN\_ANY is tried.** **If neither LESS\_OSC8\_OPEN\_xxx nor LESS\_OSC8\_OPEN\_ANY is set,** **links using the "xxx" scheme cannot be opened.** **However, there is a default value for LESS\_OSC8\_OPEN\_ANY** **which invokes the program** **less-osc8-open**(1). **This program will open links with the** **schemes "man" (by running** [**man**(1)](/man/1.md)) **or "file" (by running another instance of** [**less**(1)](/less/1.md) **if the file is local).** **less-osc8-open** **should work on systems which provide a POSIX-compatible shell.** **Any shell metacharacters such as semicolons, dollar signs, ampersands, etc.** **in the URI will be shell-escaped before the URI is appended to the handler command.** **If the handler passes the URI or any substring of it to a shell,** **it should take care to appropriately quote such strings,** **to prevent execution of unintended shell commands when opening** **a URI which contains shell metacharacters.** **As a special case, 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 rather than running** **a handler program.** - ^X **When the "Waiting for data" message is displayed,** **such as while in the F command, pressing ^X** **will stop** **less** **from waiting and return to a prompt.** **This may cause** **less** **to think that the file ends at the current position,** **so it may be necessary to use the R or F command to see more data.** **The** **--intr** **option can be used to specify a different character** **to use instead of ^X.** **This command works only on systems that support the** [**poll**(2)](/poll/2.md) **function.** **On systems without** [**poll**(2)](/poll/2.md), **the interrupt character (usually ^C) can be used instead.** ## OPTIONS **Command line options are described below.** **Most options may be changed while** **less** **is running, via the "-" command.** **Some options may be given in one of two forms:** **either a dash followed by a single letter,** **or two dashes followed by a long option name.** **A long option name may be abbreviated as long as** **the abbreviation is unambiguous.** **For example,** **--mouse** **may be abbreviated** **--mou**, **but not** **--mo**, **since both** **--mouse** **and** **--modelines** **begin with** **--mo**. **Some long option names are in uppercase, such as** **--QUIT-AT-EOF**, **as** **distinct from** **--quit-at-eof**. **Such option names need only have their first letter capitalized;** **the remainder of the name may be in either case.** **For example,** **--Quit-at-eof** **is equivalent to** **--QUIT-AT-EOF**. **Options are also taken from the environment variable "LESS".** **For example,** **to avoid typing "less -options ..." each time** **less** **is invoked, you might tell** **csh**: **setenv LESS "-options"** **or if you use** **sh**: **LESS="-options"; export LESS** **On MS-DOS and Windows, you don't need the quotes, but you should** **be careful that any percent signs in the options string are not** **interpreted as an environment variable expansion.** **The environment variable is parsed before the command line,** **so command line options override the LESS environment variable.** **If an option appears in the LESS variable, it can be reset** **to its default value on the command line by beginning the command** **line option with** "**-+**". **Some options like** **-k** **or** **-D** **require a string to follow the option letter.** **The string for that option is considered to end when a dollar sign ($) is found.** **For example, you can set two** **-D** **options like this:** ``` LESS="Dnwb$Dsbw" ``` **If the** **--use-backslash** **option appears earlier in the options, then** **a dollar sign or backslash may be included literally in an option string** **by preceding it with a backslash.** **If the** **--use-backslash** **option is not in effect, then backslashes are** **not treated specially, and there is no way to include a dollar sign** **in the option string.** - **-?** or **--help** **This option displays a summary of the commands accepted by** **less** **(the same as the h command).** **(Depending on how your shell interprets the question mark,** **it may be necessary to quote the question mark, thus: "-\\?".)** - **-a** or **--search-skip-screen** **By default, forward searches start at the top of the displayed screen** **and backwards searches start at the bottom of the displayed screen** **(except for repeated searches invoked by the n or N commands,** **which start after or before the "target" line respectively;** **see the** **-j** **option for more about the target line).** **The** **-a** **option causes forward searches to instead start at** **the bottom of the screen** **and backward searches to start at the top of the screen,** **thus skipping all lines displayed on the screen.** - **-A** or **--SEARCH-SKIP-SCREEN** **auses 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.** - **-b***n* or **--buffers=***n* **Specifies the amount of buffer space** **less** **will use for each file, in units of kilobytes (1024 bytes).** **By default 64 KB of buffer space is used for each file** **(unless the file is a pipe; see the** **-B** **option).** **The** **-b** **option specifies instead that** *n* **kilobytes of** **buffer space should be used for each file.** **If** *n* **is -1, buffer space is unlimited; that is,** **the entire file can be read into memory.** - **-B** or **--auto-buffers** **By default, when data is read from a pipe,** **buffers are allocated automatically as needed.** **If a large amount of data is read from the pipe, this can cause** **a large amount of memory to be allocated.** **The** **-B** **option disables this automatic allocation of buffers for pipes,** **so that only 64 KB** **(or the amount of space specified by the** **-b** **option)** **is used for the pipe.** **Warning: use of** **-B** **can result in erroneous display, since only the** **most recently viewed part of the piped data is kept in memory;** **any earlier data is lost.** **Lost characters are displayed as question marks.** - **-c** or **--clear-screen** **Causes full screen repaints to be painted from the top line down.** **By default,** **full screen repaints are done by scrolling from the bottom of the screen.** - **-C** or **--CLEAR-SCREEN** **Same as** **-c**, **for compatibility with older versions of** **less**. - **-d** or **--dumb** **The** **-d** **option suppresses the error message** **normally displayed if the terminal is dumb;** **that is, lacks some important capability,** **such as the ability to clear the screen or scroll backward.** **The** **-d** **option does not otherwise change the behavior of** **less** **on a dumb terminal.** - **-Dx***color* or **--color=x***color* **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.** - J **Target line when highlighted via --hilite-target.** - M **Mark letters in the status column.** - N **Line numbers enabled via the** **-N** **option.** - O **OSC 8 hyperlinks.** - P **Prompts.** - R **The rscroll character.** - S **Search results.** - T **The tilde lines displayed after the end of the file or** **before the beginning of the file.** - W **The highlight enabled via the** **-w** **option.** - 1-5 **The text in a search result which matches** **the first through fifth parenthesized sub-pattern.** **Sub-pattern coloring works only if** **less** **is built with one of the regular expression libraries** **posix**, **pcre**, or **pcre2**. - d **Bold text.** - k **Blinking text.** - s **Standout text.** - u **Underlined text.** **The uppercase letters and digits can be used only when the** **--use-color** **option is enabled.** **When text color is specified by both an uppercase letter and a lowercase letter,** **the uppercase letter takes precedence.** **For example, error messages are normally displayed as standout text.** **So if both "s" and "E" are given a color, the "E" color applies** **to error messages, and the "s" color applies to other standout text.** **The lowercase letters refer to bold and underline text formed by** **overstriking with backspaces (see the** **-U** **option) and to non-content** **text (such as line numbers and prompts),** **but not to text formatted using ANSI escape sequences with the** **-R** **option** **(but see the note below for different behavior on Windows and MS-DOS).** **A lowercase letter may be followed by a + to indicate that** **the normal format change and the specified color should both be used.** **For example,** **-Dug** **displays underlined text as green without underlining;** **the green color has replaced the usual underline formatting.** **But** **-Du+g** **displays underlined text as both green and in underlined format.** *color* **is either a 4-bit color string or an 8-bit color string:** **A 4-bit color string is one or two characters, where** **the first character specifies the foreground color and** **the second specifies the background color as follows:** - b **Blue** - c **Cyan** - g **Green** - k **Black** - m **Magenta** - r **Red** - w **White** - y **Yellow** **The corresponding uppercase letter denotes a brighter shade of the color.** **For example,** **-DNGk** **displays line numbers as bright green text on a black** **background, and** **-DEbR** **displays error messages as blue text on a** **bright red background.** **If either character is a "-" or is omitted, the corresponding color** **is set to that of normal text.** **An 8-bit color string is one or two decimal integers separated by a dot,** **where the first integer specifies the foreground color and** **the second specifies the background color.** **Each integer is a value between 0 and 255 inclusive which selects** **a "CSI 38;5" color value** **(an** **SGR escape sequence** ⟨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 overstruck 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** ⟨https://\\:learn\\:.microsoft\\:.com/\\:en\\-us/\\:windows/\\:console/\\:char\\-info\\-str⟩ **value, between 0 and 15 inclusive.** - **To avoid confusion, it is recommended that the equivalent letters rather than numbers** **be used after a lowercase color selector on MS-DOS/Windows.** - • **Numeric color values ("CSI 38;5" color) following an uppercase 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)** **making lowercase color selector letters not affect text formatted** **with ANSI escape sequences, and (2)** **allowing "CSI 38;5" color sequences in the content** **work by passing them to the terminal (only on Windows 10 and later; on** **earlier Windows systems, such sequences do not work regardless of the setting of** **-Da**). - **-e** or **--quit-at-eof** **Causes** **less** **to automatically exit** **the second time it reaches end-of-file.** **By default, the only way to exit** **less** **is via the "q" command.** - **-E** or **--QUIT-AT-EOF** **Causes** **less** **to automatically exit the first time it reaches end-of-file.** - **-f** or **--force** **Forces non-regular files to be opened.** **(A non-regular file is a directory or a device special file.)** **Also suppresses the warning message when a binary file is opened.** **By default,** **less** **will refuse to open non-regular files.** **Note that some operating systems will not allow directories** **to be read, even if** **-f** **is set.** - **-F** or **--quit-if-one-screen** **Causes** **less** **to automatically exit** **if the entire file can be displayed on the first screen.** **Also see the description of the LESS\_SHELL\_LINES environment variable below.** - **-g** or **--hilite-search** **Normally,** **less** **will highlight ALL strings which match the last search command.** **The** **-g** **option changes this behavior to highlight only the particular string** **which was found by the last search command.** **This can cause** **less** **to run somewhat faster than the default.** - **-G** or **--HILITE-SEARCH** **The -G option suppresses all highlighting of strings found by search commands.** - **-h***n* 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.** - **-j***n* or **--jump-target=***n* **Specifies a line on the screen where the "target" line** **is to be positioned.** **The target line is the line specified by any command to** **search for a pattern, jump to a line number,** **jump to a file percentage or jump to a tag.** **The screen line may be specified by a number: the top line on the screen** **is 1, the next is 2, and so on.** **The number may be negative to specify a line relative to the bottom** **of the screen: the bottom line on the screen is -1, the second** **to the bottom is -2, and so on.** **Alternately, the screen line may be specified as a fraction of the height** **of the screen, starting with a decimal point: .5 is in the middle of the** **screen, .3 is three tenths down from the first line, and so on.** **If the line is specified as a fraction, the actual line number** **is recalculated if the terminal window is resized.** **If the** **--header** **option is used and the target line specified by** **-j** **would be obscured by the header, the target line is moved to the first** **line after the header.** **If any form of the** **-j** **option is used,** **repeated forward searches (invoked with "n" or "N")** **begin at the line immediately after the target line,** **and repeated backward searches begin at the target line,** **unless changed by** **-a** **or** **-A**. **For example, if** "**-j4**" **is used, the target line is the** **fourth line on the screen, so forward searches begin at the fifth line** **on the screen.** **However nonrepeated searches (invoked with "/" or "?")** **always begin at the first or last line on the screen respectively.** - **-J** or **--status-column** **Displays a status column at the left edge of the screen.** **The character displayed in the status column may be one of:** - \> **The line is chopped with the** **-S** **option, and** **the text that is chopped off beyond the right edge of the screen** **contains a match for the current search.** - \< **The line is horizontally shifted, and** **the text that is shifted beyond the left side of the screen** **contains a match for the current search.** - \= **The line is both chopped and shifted,** **and there are matches beyond both sides of the screen.** - \* **There are matches in the visible part of the line** **but none to the right or left of it.** - a-z, A-Z **The line has been marked with the corresponding letter via the m or M command.** - \# **The line has been marked by left-clicking it with the mouse** **when the** **--mouse** **option is in effect.** - **-k***filename* or **--lesskey-file=***filename* **Causes** **less** **to open and interpret the named file as a** [**lesskey**(5)](/lesskey/5.md) **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**(5)](/lesskey/5.md) **source file.** **If the LESSKEYIN or LESSKEYIN\_SYSTEM environment variable is set, or** **if a lesskey source file is found in a standard place (see KEY BINDINGS),** **it is also used as a lesskey source file.** **Prior to version 582, the** **lesskey** **program needed to be run to convert a lesskey** *source* **file to a lesskey** *binary* **file for** **less** **to use.** **Newer versions of** **less** **read the lesskey source** **file directly and ignore the binary file if the source file exists.** **Note the warning under** **--lesskey-content** **below.** - **--lesskey-content=***text* **Causes** **less** **to interpret the specified text as the contents of a** [**lesskey**(5)](/lesskey/5.md) **source file.** **In the text,** **lesskey** **lines may be separated by either newlines as usual, or by semicolons.** **A literal semicolon may be represented by a backslash followed by a semicolon.** - **Warning: certain environment variables such as** **LESS, LESSSECURE, LESSCHARSET and others,** **which are used early in startup,** **cannot be set in a file specified by a command line option** (**--lesskey**, **--lesskey-src** **or** **--lesskey-content**). **When using a** **lesskey** **file to set environment variables, it is safer to use the** **default lesskey file, or to specify the file using the** **LESSKEYIN or LESSKEY\_CONTENT environment variables rather than using** **a command line option.** - **-K** or **--quit-on-intr** **Causes** **less** **to exit immediately (with status 2)** **when an interrupt character (usually ^C) is typed.** **Normally, an interrupt character causes** **less** **to stop whatever it is doing and return to its command prompt.** - **-L** or **--no-lessopen** **Ignore the LESSOPEN environment variable** **(see the INPUT PREPROCESSOR section below).** **This option can be set from within** **less**, **but it will apply only to files opened subsequently, not to the** **file which is currently open.** - **-m** or **--long-prompt** **Causes** **less** **to prompt verbosely (like** [**more**(1)](/more/1.md)), **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)](/more/1.md). - **-n** or **--line-numbers** **Suppresses line numbers.** **The default (to use line numbers) may cause** **less** **to run more slowly in some cases, especially with a very large input file.** **Using line numbers means: the line number will be displayed in the verbose** **prompt and in the = command,** **and the v command will pass the current line number to the editor** **(see also the discussion of LESSEDIT in PROMPTS below).** - **-N** or **--LINE-NUMBERS** **Causes a line number to be displayed at the beginning of** **each line in the display.** - **-o***filename* 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.** - **-O***filename* 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**. - **-p***pattern* 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.** - **-P***prompt* or **--prompt=***prompt* **Provides a way to tailor the three prompt** **styles to your own preference.** **This option would normally be put in the LESS environment** **variable, rather than being typed in with each** **less** **command.** **Such an option must either be the last option in the LESS variable,** **or be terminated by a dollar sign.** - **-Ps** **followed by a string changes the default (short) prompt** **to that string.** - **-Pm** **changes the medium** (**-m**) **prompt.** - **-PM** **changes the long** (**-M**) **prompt.** - **-Ph** **changes the prompt for the help screen.** - **-P=** **changes the message printed by the = command.** - **-Pw** **changes the message printed while waiting for data (in the "F" command).** - **All prompt strings consist of a sequence of** **letters and special escape sequences.** **See the section on PROMPTS for more details.** - **-q** or **--quiet** or **--silent** **Causes moderately "quiet" operation:** **the terminal bell is not rung** **if an attempt is made to scroll past the end of the file** **or before the beginning of the file.** **If the terminal has a "visual bell", it is used instead.** **The bell will be rung on certain other errors,** **such as typing an invalid character.** **The default is to ring the terminal bell in all such cases.** - **-Q** or **--QUIET** or **--SILENT** **Causes totally "quiet" operation:** **the terminal bell is never rung.** **If the terminal has a "visual bell", it is used in all cases** **where the terminal bell would have been rung.** - **-r** or **--raw-control-chars** **Causes "raw" control characters to be displayed.** **The default is to display control characters using the caret notation;** **for example, a control-A (octal 001) is displayed as "^A"** **(with some exceptions as described under the** **-U** **option).** **Warning: when the** **-r** **option is used,** **less** **cannot keep track of the actual appearance of the screen** **(since this depends on how the screen responds to** **each type of control character).** **Thus, various display problems may result,** **such as long lines being split in the wrong place.** - **USE OF THE** **-r** **OPTION IS DANGEROUS AND IS NOT RECOMMENDED.**\ **The** **-r** **option can be set on the command line or via the - command,** **but to avoid unintentional use, it cannot be set in a LESS environment variable.** **If** **-r** **appears in a LESS environment variable, it is treated as if it were** **-R**. - **-R** or **--RAW-CONTROL-CHARS** **Like** **-r**, **but only a limited set of escape** **sequences are output in "raw" form.** **Unlike** **-r**, **the screen appearance is maintained correctly.** **The sequences which are output raw are:** - **1. ANSI SGR ("color") sequences** - **2. OSC 8 hyperlinks** - **3. Other OSC sequences, if the OSC type number is listed in** **the LESSANSIOSCALLOW environment variable** - **4. OSC sequences starting with a non-standard introductory character** **(that is, something other than "\]"), if the character is listed in** **the LESSANSIOSCCHARS environment variable followed by an asterisk** - **ANSI color escape sequences are sequences of the form:** - ``` ESC [ ... m ``` - **where the "..." is zero or more color specification characters.** **Color escape sequences are only supported when the color** **is changed within one line, not across lines.** **In other words, the beginning of each line is assumed to be** **normal (non-colored), regardless of any escape sequences in previous lines.** - **You can make** **less** **think that characters other than "m" can end ANSI color escape sequences** **by setting the environment variable LESSANSIENDCHARS to the list of** **characters which can end a color escape sequence.** **And you can make** **less** **think that characters other than the standard ones may appear between** **the ESC and the m by setting the environment variable LESSANSIMIDCHARS** **to the list of characters which can appear.** - **OSC sequences are of the form:** - ``` ESC ] N ; ... \7 ``` - **where the OSC type number N is a decimal integer.** **The terminating sequence may be either a BEL character (\\7)** **as above, or the two-character sequence "ESC \\".** - **-s** or **--squeeze-blank-lines** **Causes consecutive blank lines to be squeezed into a single blank line.** **This is useful when viewing** [**nroff**(1)](/nroff/1.md) **output.** - **-S** or **--chop-long-lines** **Causes lines longer than the screen width to be** **chopped (truncated) rather than wrapped.** **That is, the portion of a long line that does not fit in** **the screen width is not displayed until you press RIGHT-ARROW.** **The default is to wrap long lines; that is, display the remainder** **on the next line.** **See also the** **--wordwrap** **option.** **While the** **--header** **option is active, the** **-S** **option is ignored,** **and lines longer than the screen width are truncated.** - **-t***tag* 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)](/ctags/1.md) **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)](/global/1.md), **and that command is executed to find the tag.** **(See the** **GNU global home page** ⟨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**. - **-T***tagsfile* or **--tag-file=***tagsfile* **Specifies a tags file to be used instead of "tags".** - **-u** or **--underline-special** **Causes backspaces and carriage returns to be treated as printable characters;** **that is, they are sent to the terminal when they appear in the input.** - **-U** or **--UNDERLINE-SPECIAL** **Causes backspaces, tabs, carriage returns and "formatting characters"** **(as defined by Unicode) to be treated as control characters;** **that is, they are handled as specified by the** **-r** **option.** - **By default, if neither** **-u** **nor** **-U** **is given,** **backspaces which appear adjacent to an underscore character** **are treated specially:** **the underlined text is displayed** **using the terminal's hardware underlining capability.** **Also, backspaces which appear between two identical characters** **are treated specially:** **the overstruck text is printed** **using the terminal's hardware boldface capability.** **Other backspaces are deleted, along with the preceding character.** **Carriage returns immediately followed by a newline are deleted.** **Other carriage returns are handled as specified by the** **-r** **option.** **Unicode formatting characters, such as the Byte Order Mark,** **are sent to the terminal.** **Text which is overstruck or underlined can be searched for** **if neither** **-u** **nor** **-U** **is in effect.** - **See also the** **--proc-backspace**,**--proc-tab**, and **--proc-return** **options.** - **-V** or **--version** **Displays the version number of** **less**. - **-w** or **--hilite-unread** **Temporarily highlights the first "new" line after a movement** **of a full page.** **The first "new" line is the line immediately following the line previously** **at the bottom of the screen.** **Also highlights the target line after a g or p command.** **The highlight is removed at the next command which causes movement.** **If the** **--status-line** **option is in effect, the entire line** **(the width of the screen) is highlighted.** **Otherwise, only the text in the line is highlighted,** **unless the** **-J** **option is in effect,** **in which case only the status column is highlighted.** - **-W** or **--HILITE-UNREAD** **Like** **-w**, **but temporarily highlights the first new line after any** **movement command larger than one line.** - **-x***n*,... 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.** **Position numbers are zero-based: the leftmost position is 0,** **the next is 1, etc.** **For example,** "**-x8,16**" **is the same as** "**-x8**" **and sets tabs at position 8, 16, 24, 32, etc.** "**-x10,14,20**" **will set tabs at position 10, 14, 20, 26, 32, 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 initialization or deinitialization does** **something unnecessary, like clearing the screen.** **Note that some terminals require the initialization string for proper** **operation, so they may not behave completely correctly when** **-X** **is used.** - **-y***n* 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* or -*n* **Changes the default scrolling window size to** *n* **lines.** **The default is one screenful.** **The z and w commands can also be used to change the window size.** **The "z" may be omitted for compatibility with some versions of** [**more**(1)](/more/1.md). **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 later 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.** - **--autosave=***actions* **Normally, the history file is saved only when** **less** **exits.** **This option specifies other actions which will cause the history file to be saved.** **Each action is defined by a single character in the** *actions* **string:** - m **Setting or clearing a mark while** **--save-marks** **is in effect.** - / **Searching.** - ! **Running a shell command.** - \* **Any action; same as "m/!".** - **Can be set to "-" to specify the default, that only exiting** **less** **will cause the history file to be saved.** **Note that, depending on your shell, if you specify this option on the** **command line, the "!" and "\*" characters may need to be escaped or quoted.** - **--cmd=***commands* **The specified string is taken to be an initial command to** **less**. **This is similar to specifying "+***commands***", except that** **commands specified by** **--cmd** **are not executed if** **less** **exits immediately due to the use of the** **-E** **or** **-F** **option, while** **commands specified by the + option are executed even if** **less** **exits immediately.** - **--emouse=***features* *features* **is a comma-separated list of mouse features to be enabled,** **selected from this list:** - vscroll **Scrolling the mouse wheel down or up moves forward or backward in** **the file.** **The number of lines to scroll when the wheel is moved can be set by the** **--wheel-lines** **option.** **The** **--rmouse** **option reverses the direction of movement.** - vdrag **Holding down the left button and dragging up or down moves** **forward or backward in the file.** - hscroll **Scrolling the side scroll wheel left or right moves left or right** **in the file.** **The number of columns to scroll when the wheel is moved can be set by the** **--wheel-lines** **option.** **The** **--rmouse** **option reverses the direction of movement.** - hdrag **Holding down the left button and dragging left or right moves** **left or right in the file.** - lclick **Left-clicking sets the "#" mark to the line where the mouse is clicked.** **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.** - rclick **Right-clicking (or clicking any button other than the left one)** **returns to the "#" mark position.** - scroll **Same as "vscroll,hscroll".** - drag **Same as "vdrag,hdrag".** - hmove **Same as "hscroll,hdrag".** - vmove **Same as "vscroll,vdrag".** - move **Same as "vmove,hmove".** - click **Same as "lclick,rclick".** - all **Same as "move,click".** - **Each feature name may be abbreviated as long as the abbreviation** **is unambiguous.** **If** *features* **is set to "-", all mouse features are disabled.** **Mouse input works only on terminals which support X11 mouse reporting,** **and on Windows.** - **--end-prompt=***string* **Specifies a string which is printed immediately after the prompt is erased.** **As with the --prompt option, the first character of the string** **determines which prompt the string will be printed after** **("s" for the short prompt, "m" for the medium prompt,** **or "M" for the long prompt).** **Special characters in the string are processed as described in the PROMPTS** **section, in the same way as prompts specified by the --prompt option.** **If set to a dash (-), nothing is printed after the prompt is erased.** **This option can be useful if the prompt string has been modified to contain** **an escape sequence that puts the terminal in a mode which should be cleared** **when the prompt is erased.** - **--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.** **With this option enabled, the = command and the long prompt will display** **the number of lines in the file.** **Normally this is not done, because it can be slow if the input file** **is non-seekable (such as a pipe) and is large.** - **--follow-name** **Normally, if the input file is renamed while an F command is executing,** **less** **will continue to display the contents of the original file despite** **its name change.** **If** **--follow-name** **is specified, during an F command** **less** **will periodically attempt to reopen the file by name.** **If the reopen succeeds and the file is a different file from the original** **(which means that a new file has been created** **with the same name as the original (now renamed) file),** **less** **will display the contents of that new file.** - **--form-feed** **When scrolling forward or backward in the file,** **stop if a line beginning with a form feed character (^L) is reached.** **This can be useful when viewing a file which uses form feeds between pages.** - **--header=***L*,*C*,*N* **Sets the number of header lines and columns displayed on the screen.** **The number of header lines is set to** *L***.** **If** *L* **is 0, header lines are disabled.** **If** *L* **is empty or missing, the number of header lines is unchanged.** **The number of header columns is set to** *C***.** **If** *C* **is 0, header columns are disabled.** **If** *C* **is empty or missing, the number of header columns is unchanged.** **The first header line is set to line number** *N* **in the file.** **If** *N* **is empty or missing, it is taken to be** **the number of the line currently displayed in the first line of the screen** **(if the** **--header** **command has been issued from within** **less**), **or 1 (if the** **--header** **option has been given on the command line).** **The special form** "**--header=-**" **disables header lines and header columns,** **and is equivalent to** "**--header=0,0**". **When** *L* **is nonzero, the first** *L* **lines at the top** **of the screen are replaced with the** *L* **lines of the file beginning at line** *N***,** **regardless of what part of the file is being viewed.** **When header lines are displayed, any file contents before the header line cannot be viewed.** **When** *C* **is nonzero, the first** *C* **characters displayed at the** **beginning of each line are replaced with the first** *C* **characters of the line,** **even if the rest of the line is scrolled horizontally.** **While the** **--header** **option is active,** **lines longer than the screen width are truncated,** **and the** **-S** **option is ignored.** - **--hilite-target** **Highlights the "target" line, as specified by the -j option.** **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.** - **--incsearch** **Subsequent search commands will be "incremental"; that is,** **less** **will advance to the next line containing the search pattern** **as each character of the pattern is typed in.** - **--intr=***c* **Use the character** *c* **instead of ^X to interrupt a read** **when the "Waiting for data" message is displayed.** *c* **must be an ASCII character; that is, one with a value** **between 1 and 127 inclusive.** **A caret followed by a single character can be used** **to specify a control character.** - **--line-num-width=***n* **Sets the minimum width of the line number field when the -N option is in effect** **to** *n* **characters.** **The default is 7.** - **--match-shift=***n* **When** **-S** **is in effect, if a search match is not visible** **because it is shifted to the left or right of the currently** **visible screen, the text will horizontally shift** **to ensure that the search match is visible.** **This option selects the column in which the first character** **of the search match will be placed after the shift.** **In other words, there will be** *n* **characters visible** **to the left of the search match.** - **Alternately, the number may be specified as a fraction of the width** **of the screen, starting with a decimal point: .5 is half of the** **screen width, .3 is three tenths of the screen width, and so on.** **If the number is specified as a fraction, the actual number of** **scroll positions is recalculated if the terminal window is resized.** - **--modelines=***n* **Before displaying a file,** **less** **will read the first** *n* **lines to try to find a vim-compatible** *modeline*. **If** *n* **is zero,** **less** **does not try to find modelines.** **By using a modeline, the file itself can specify the tab stops** **that should be used when viewing it.** **A modeline contains, anywhere in the line,** **a program name ("vi", "vim", "ex", or "less"),** **followed by a colon,** **possibly followed by the word "set",** **and finally followed by zero or more option settings.** **If the word "set" is used,** **option settings are separated by spaces, and end at the first colon.** **If the word "set" is not used,** **option settings may be separated by either spaces or colons.** **The word "set" is required if the program name is "less"** **but optional if any of the other three names are used.** **If any option setting is of the form "tabstop=***n***" or "ts=***n***",** **then tab stops are automatically set as if** **--tabs=***n* **had been given.** **See the** **--tabs** **description for acceptable values of** *n***.** - **--mouse** **Enabling --mouse is the same as --emouse=vmove,click.** **Disabling --mouse is the same as --emouse=-.** - **--MOUSE** **Like** **--mouse** **with** **--rmouse**. - **--no-edit-warn** **Don't print a warning message when using the v command** **on a file which was opened using a LESSOPEN preprocessor** **(see the INPUT PREPROCESSOR section below).** - **--no-keypad** **Disables sending the keypad initialization and deinitialization strings** **to the terminal.** **This is sometimes useful if the keypad strings make the numeric** **keypad behave in an undesirable manner.** - **--no-histdups** **This option changes the behavior so that if a search string or** **file name is typed in, and the same string is already in the history list,** **the existing copy is removed from the history list before the new one is added.** **Thus, a given string will appear only once in the history list.** **Normally, a string may appear multiple times.** - **--no-number-headers** **Header lines (defined via the** **--header** **option) are not assigned line numbers.** **Line number 1 is assigned to the first line after any header lines.** - **--no-paste** **If the terminal supports** **xterm**-compatible **"bracketed paste", any text pasted into** **less** **is ignored, except that one line of text may be pasted into the command line** **at the bottom of the screen (search strings, file names, etc).** **That is, the first newline of text pasted into the command line** **and any text that follows it is ignored.** - **--no-search-header-lines** **Searches do not include header lines, but still include header columns.** - **--no-search-header-columns** **Searches do not include header columns, but still include header lines.** - **--no-search-headers** **Searches do not include header lines or header columns.** - **--no-vbell** **Disables the terminal's visual bell.** - **--past-eof** **Normally, scrolling commands (other than J, K, ESC-SPACE and ESC-b)** **stop scrolling when end-of-file is reached scrolling forward, or** **beginning-of-file is reached scrolling backward.** **This option makes all scrolling commands continue past end-of-file** **or beginning-of-file.** - **--proc-backspace** **If set, backspaces are handled as if neither the** **-u** **option** **nor the** **-U** **option were set.** **That is, a backspace adjacent to an underscore causes text to be** **displayed in underline mode, and a backspace between identical** **characters cause text to be displayed in boldface mode.** **This option overrides the** **-u** **and** **-U** **options, so that display of** **backspaces can be controlled separate from tabs and carriage returns.** **If not set, backspace display is controlled by the** **-u** **and** **-U** **options.** - **--PROC-BACKSPACE** **If set, backspaces are handled as if the** **-U** **option were set;** **that is backspaces are treated as control characters.** - **--proc-return** **If set, carriage returns are handled as if neither the** **-u** **option** **nor the** **-U** **option were set.** **That is, a carriage return immediately before a newline is deleted.** **This option overrides the** **-u** **and** **-U** **options, so that display of** **carriage returns can be controlled separate from that of backspaces and tabs.** **If not set, carriage return display is controlled by the** **-u** **and** **-U** **options.** - **--PROC-RETURN** **If set, carriage returns are handled as if the** **-U** **option were set;** **that is carriage returns are treated as control characters.** - **--proc-tab** **If set, tabs are handled as if the** **-U** **option were not set.** **That is, tabs are expanded to spaces.** **This option overrides the** **-U** **option, so that display of** **tabs can be controlled separate from that of backspaces and carriage returns.** **If not set, tab display is controlled by the** **-U** **option.** - **--PROC-TAB** **If set, tabs are handled as if the** **-U** **option were set;** **that is tabs are treated as control characters.** - **--redraw-on-quit** **When quitting, after sending the terminal deinitialization string,** **redraws the entire last screen.** **On terminals whose terminal deinitialization string causes the** **terminal to switch from an alternate screen,** **this makes the last screenful of the current file remain visible after** **less** **has quit.** - **--rmouse** **Reverses the normal direction of scrolling when mouse scrolling is** **enabled via --emouse=vscroll or --emouse=hscroll.** - **--rscroll=***c* **This option changes the character used to mark truncated lines.** **It may begin with a two-character attribute indicator like LESSBINFMT does.** **If there is no attribute indicator, standout is used.** **If set to "-", truncated lines are not marked.** - **--save-marks** **Save marks in the history file, so marks are retained** **across different invocations of** **less**. - **--search-options=***...* **Sets default search modifiers.** **The value is a string of one or more of the characters** **E, F, K, N, R or W.** **Setting any of these has the same effect as typing that** **control character at the beginning of every search pattern.** **For example, setting** **--search-options=*W*** **is the same as** **typing ^W at the beginning of every pattern.** **The value may also contain a digit between 1 and 5,** **which has the same effect as typing ^S followed by that digit** **at the beginning of every search pattern.** **The value "-" disables all default search modifiers.** - **--show-preproc-errors** **If a LESSOPEN preprocessor produces data,** **then exits with a non-zero exit code,** **less** **will display a warning.** - **--status-col-width=***n* **Sets the width of the status column when the** **-J** **option is in effect.** **The default is 2 characters.** - **--status-line** **If a line is marked, the entire line (rather than just the status column)** **is highlighted.** **Also lines highlighted due to the** **-w** **or** **--hilite-target** **option will have** **the entire line highlighted.** **If** **--use-color** **is set, the line is colored rather than highlighted.** - **--use-backslash** **This option changes the interpretations of options which follow this one.** **After the** **--use-backslash** **option, any backslash in an option string is** **removed and the following character is taken literally.** **This allows a dollar sign to be included in option strings.** - **--use-color** **Enables colored text in various places.** **The** **-D** **option can be used to change the colors.** **Colored text works only if the terminal supports** **ANSI color escape sequences (as defined in** **ECMA-48** ⟨https://\\:www\\:.ecma\\-international\\:.org/\\:publications\\-and\\-standards/\\:standards/\\:ecma\\-48)⟩. - **--wheel-lines=***n* **Set the number of lines or columns to scroll when the mouse wheel is scrolled** **and the** **--mouse** **or** **--MOUSE** **option is in effect.** **The default is 1 line or column.** - **--wordwrap** **When the** **-S** **option is not in use,** **wrap each line at a space or tab if possible,** **so that a word is not split between two lines.** **The default is to wrap at any character.** - **--** **A command line argument of** "**--**" **marks the end of option arguments.** **Any arguments following this are interpreted as filenames.** **This can be useful when viewing a file whose name begins with a "-" or "+".** **Otherwise, option arguments and filename arguments can be intermixed;** **that is, option arguments do not need to appear before filename arguments,** **unless the environment variable POSIXLY\_CORRECT is set.** - \+ **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, +\ acts like +\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.** **Also see the** **--cmd** **option.** ## LINE EDITING **When entering a command line at the bottom of the screen** **(for example, a filename for the :e command,** **or the pattern for a search command),** **certain keys can be used to manipulate the command line.** **Most commands have an alternate form in \[ brackets \] which can be used if** **a key does not exist on a particular keyboard.** **(Note that the forms beginning with ESC do not work** **on some MS-DOS and Windows systems because ESC is the line erase character.)** **Any of these special keys may be entered literally by preceding** **it with the "literal" character, either ^V or ^A.** **A backslash itself may also be entered literally by entering two backslashes.** - LEFTARROW \[ ESC-h \] **Move the cursor one space to the left.** - RIGHTARROW \[ ESC-l \] **Move the cursor one space to the right.** - ^LEFTARROW \[ ESC-b or ESC-LEFTARROW \] **(That is, CONTROL and LEFTARROW simultaneously.)** **Move the cursor one word to the left.** - ^RIGHTARROW \[ ESC-w or ESC-RIGHTARROW \] **(That is, CONTROL and RIGHTARROW simultaneously.)** **Move the cursor one word to the right.** - HOME \[ ESC-0 \] **Move the cursor to the beginning of the line.** - END \[ ESC-$ \] **Move the cursor to the end of the line.** - BACKSPACE **Delete the character to the left of the cursor,** **or cancel the command if the command line is empty.** - DELETE \[ ESC-x \] **Delete the character under the cursor.** - ^BACKSPACE \[ ESC-BACKSPACE \] **(That is, CONTROL and BACKSPACE simultaneously.)** **Delete the word to the left of the cursor.** - ^DELETE \[ ESC-X or ESC-DELETE \] **(That is, CONTROL and DELETE simultaneously.)** **Delete the word under the cursor.** - UPARROW \[ ESC-k \] **Retrieve the previous command line.** **If you first enter some text and then press UPARROW,** **it will retrieve the previous command which begins with that text.** - DOWNARROW \[ ESC-j \] **Retrieve the next command line.** **If you first enter some text and then press DOWNARROW,** **it will retrieve the next command which begins with that text.** - TAB **Complete the partial filename to the left of the cursor.** **If it matches more than one filename, the first match** **is entered into the command line.** **Repeated TABs will cycle through the other matching filenames.** **If the completed filename is a directory, a "/" is appended to the filename.** **(On MS-DOS and Windows systems, a "\\" is appended.)** **The environment variable LESSSEPARATOR can be used to specify a** **different character to append to a directory name.** - BACKTAB (SHIFT-TAB) \[ ESC-TAB \] **Like TAB, but cycles in the reverse direction through the matching filenames.** - ^L **Complete the partial filename to the left of the cursor.** **If it matches more than one filename, all matches are entered into** **the command line (if they fit).** - ^U (Unix and OS/2) or ESC (MS-DOS and Windows) **Delete the entire command line,** **or cancel the command if the cursor is at the beginning of the command line.** **If you have changed your line-kill character in Unix to something** **other than ^U, that character is used instead of ^U.** - ^G **Delete the entire command line and return to the main prompt.** ## KEY BINDINGS **You may define your own** **less** **commands by creating a lesskey source file.** **This file specifies a set of command keys and an action** **associated with each key.** **You may also change the line-editing keys (see LINE EDITING),** **and set environment variables used by** **less**. **See the** [**lesskey**(5)](/lesskey/5.md) **manual page for details about the file format.** **If the environment variable LESSKEYIN is set,** **less** **uses that as the name of the lesskey source file.** **Otherwise,** **less** **looks in a standard place for the lesskey source file:** **On Unix systems,** **less** **looks for a lesskey file called "$XDG\_CONFIG\_HOME/lesskey" or "$HOME/.config/lesskey" or "$HOME/.lesskey".** **On MS-DOS and Windows systems,** **less** **looks for a lesskey file called "$HOME/\_lesskey", and if it is not found there,** **then looks for a lesskey file called "\_lesskey" in any directory specified** **in the PATH environment variable.** **On OS/2 systems,** **less** **looks for a lesskey file called "$HOME/lesskey.ini", and if it is not found,** **then looks for a lesskey file called "lesskey.ini" in any directory specified** **in the INIT environment variable, and if it not found there,** **then looks for a lesskey file called "lesskey.ini" in any directory specified** **in the PATH environment variable.** **A system-wide lesskey source file may also be set up to provide key bindings.** **If a key is defined in both a local lesskey file and in the** **system-wide file, key bindings in the local file take precedence over** **those in the system-wide file.** **If the environment variable LESSKEYIN\_SYSTEM is set,** **less** **uses that as the name of the system-wide lesskey file.** **Otherwise,** **less** **looks in a standard place for the system-wide lesskey file:** **On Unix systems, the system-wide lesskey file is /usr/local/etc/syslesskey.** **(However, if** **less** **was built with a different sysconf directory than /usr/local/etc,** **that directory is where the sysless file is found.)** **On MS-DOS and Windows systems, the system-wide lesskey file is c:\\\_syslesskey.** **On OS/2 systems, the system-wide lesskey file is c:\\syslesskey.ini.** **Older versions of** **less** **(before v582) used lesskey files with a binary format, produced by the** **lesskey** **program. It is no longer necessary to use the** **lesskey** **program.** ## INPUT PREPROCESSOR **You may define an "input preprocessor" for** **less**. **Before** **less** **opens a file, it first gives the input preprocessor a chance to modify the** **way the contents of the file are displayed.** **An input preprocessor is simply an executable program (or shell script),** **which writes the contents of the file to a different file,** **called the replacement file.** **The contents of the replacement file are then displayed** **in place of the contents of the original file.** **However, it will appear to the user as if the original file is opened;** **that is,** **less** **will display the original filename as the name of the current file.** **An input preprocessor receives one command line argument, the original filename,** **as entered by the user.** **It should create the replacement file, and when finished,** **print the name of the replacement file to its standard output.** **If the input preprocessor does not output a replacement filename,** **less** **uses the original file, as normal.** **The input preprocessor is not called when viewing standard input.** **To set up an input preprocessor, set the LESSOPEN environment variable** **to a command line which will invoke your input preprocessor.** **This command line should include one occurrence of the string "%s",** **which will be replaced by the filename** **when the input preprocessor command is invoked.** **Two consecutive percent signs are replaced with a single percent sign.** **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.** **Two consecutive percent signs are replaced with a single percent sign.** **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 data directly to** **less**, **rather than putting the data into a replacement file.** **This avoids the need to decompress the entire file before** **starting to view it.** **An input preprocessor that works this way is called an input pipe.** **An input pipe, instead of writing the name of a replacement file on** **its standard output,** **writes the entire contents of the replacement file on its standard output.** **If the input pipe does not write any characters on its standard output,** **then there is no replacement file and** **less** **uses the original file, as normal.** **To use an input pipe,** **make the first character in the LESSOPEN environment variable a** **vertical bar (\|) to signify that the input preprocessor is an input pipe.** **As with non-pipe input preprocessors, the command string must contain one** **occurrence of %s, which is replaced with the filename of the input file.** **For example, on many Unix systems, this script will work like the** **previous example scripts:** **lesspipe.sh:**\ \ **#! /bin/sh**\ \ **case "$1" 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 interpreted as meaning there is no replacement, and** **the original file is used.** **To avoid this, if LESSOPEN starts with two vertical bars,** **the exit status of the script determines the behavior when the output is empty.** **If the output is empty and the exit status is zero,** **the empty output is considered to be replacement text.** **If the output is empty and the exit status is nonzero,** **the original file is used.** **For compatibility with previous versions of** **less**, **if LESSOPEN starts with only one vertical bar, the exit status** **of the preprocessor is ignored.** **When an input pipe is used, a LESSCLOSE postprocessor can be used,** **but it is usually not necessary since there is no replacement file** **to clean up.** **In this case, the replacement file name passed to the LESSCLOSE** **postprocessor is "-".** **For compatibility with previous versions of** **less**, **the input preprocessor or pipe is not used if** **less** **is viewing standard input.** **However, if the first character of LESSOPEN is a dash (-),** **the input preprocessor is used on standard input as well as other files.** **In this case, the dash is not considered to be part of** **the preprocessor command.** **If standard input is being viewed, the input preprocessor is passed** **a file name consisting of a single dash.** **Similarly, if the first two characters of LESSOPEN are vertical bar and dash** **(\|-) or two vertical bars and a dash (\|\|-),** **the input pipe is used on standard input as well as other files.** **Again, in this case the dash is not considered to be part of** **the input pipe command.** ## NATIONAL CHARACTER SETS **There are five 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.** - composing characters **are not displayed separately, but modify the display of the** **preceding character. (Only when LESSCHARSET is "utf8".)** - deleted characters **are simply deleted from the input and not displayed.** **(Only when LESSCHARSET is "utf8".)** **A "character set" is a description of which of these categories** **each character belongs to.** **The LESSCHARSET environment variable may be used to select a character set.** **Possible values for LESSCHARSET are:** - ascii **BS, TAB, NL, CR, and formfeed are control characters,** **all chars with values between 32 and 126 are normal,** **and all others are binary.** - iso8859 **Selects an ISO 8859 character set.** **This is the same as ASCII, except characters between 160 and 255 are** **treated as normal characters.** - latin1 **Same as iso8859.** - latin9 **Same as iso8859.** - dos **Selects a character set appropriate for MS-DOS.** - ebcdic **Selects an EBCDIC character set.** - IBM-1047 **Selects an EBCDIC character set used by OS/390 Unix Services.** **This is the EBCDIC analogue of latin1.** **You get similar results** **by setting either LESSCHARSET=IBM-1047 or LC\_CTYPE=en\_US** **in your environment.** - koi8-r **Selects a Russian character set.** - next **Selects a character set appropriate for NeXT computers.** - utf-8 **Selects the UTF-8 encoding of the ISO 10646 character set.** **UTF-8 is special in that it supports multi-byte characters in the input file.** **It is the only character set that supports multi-byte characters.** - windows **Selects a character set appropriate for Microsoft Windows (cp 1252).** **In rare cases, it may be desired to tailor** **less** **to use a character set other than the ones definable by LESSCHARSET.** **In this case, the environment variable LESSCHARDEF can be used** **to define a character set.** **It should be set to a string where each character in the string represents** **one character in the character set.** **The character "." is used for a normal character, "c" for control,** **and "b" for binary.** **A decimal number may be used for repetition.** **For example, "bccc4b." would mean character 0 is binary,** **1, 2 and 3 are control, 4, 5, 6 and 7 are binary, and 8 is normal.** **All characters after the last are taken to be the same as the last,** **so characters 9 through 255 would be normal.** **(This is an example, and does not necessarily** **represent any real character set.)** **This table shows the value of LESSCHARDEF which is equivalent** **to each of the possible values for LESSCHARSET:** | | | | --- | --- | | ascii | 8bcccbcc18b95.b | | dos | 8bcccbcc12bc5b95.b. | | ebcdic | 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b | | | 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b. | | IBM-1047 | 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc | | | 191.b | | iso8859 | 8bcccbcc18b95.33b. | | koi8-r | 8bcccbcc18b95.b128. | | latin1 | 8bcccbcc18b95.33b. | | next | 8bcccbcc18b95.bb125.bb | **If neither LESSCHARSET nor LESSCHARDEF is set,** **but any of the strings "UTF-8", "UTF8", "utf-8" or "utf8"** **is found in the LC\_ALL, LC\_CTYPE or LANG** **environment variables, then the default character set is utf-8.** **If that string is not found, but your system supports the** [**setlocale**(3)](/setlocale/3.md) **interface,** **less** **will use setlocale to determine the character set.** **setlocale is controlled by setting the LANG or LC\_CTYPE environment** **variables.** **Finally, if the** **setlocale** **interface is also not available, the default character set is utf-8.** **Control and binary characters are displayed in standout (reverse video).** **Each such character is displayed in caret notation if possible** **(e.g. ^A for control-A).** **Caret notation is used only if** **inverting the 0100 bit results in a normal printable character.** **Otherwise, the character is displayed as a hex number in angle brackets.** **This format can be changed by** **setting the LESSBINFMT environment variable.** **LESSBINFMT may begin with a "\*" and one character to select** **the display attribute:** **"\*k" is blinking, "\*d" is bold, "\*u" is underlined, "\*s" is standout,** **and "\*n" is normal.** **If LESSBINFMT does not begin with a "\*", normal attribute is assumed.** **The remainder of LESSBINFMT is a string which may include one** **printf-style escape sequence (a % followed by x, X, o, d, etc.).** **For example, if LESSBINFMT is "\*u\[%x\]", binary characters** **are displayed in underlined hexadecimal surrounded by brackets.** **The default if no LESSBINFMT is specified is "\*s\<%02X\>".** **Warning: the result of expanding the character via LESSBINFMT must** **be less than 31 characters.** **When the character set is utf-8, the LESSUTFBINFMT environment variable** **acts similarly to LESSBINFMT but it applies to Unicode code points** **that were successfully decoded but are unsuitable for display (e.g.,** **unassigned code points).** **Its default value is "\".** **Note that LESSUTFBINFMT and LESSBINFMT share their display attribute** **setting ("\*x") so specifying one will affect both;** **LESSUTFBINFMT is read after LESSBINFMT so its setting, if any,** **will have priority.** **Problematic octets in a UTF-8 file (octets of a truncated sequence,** **octets of a complete but non-shortest form sequence, invalid octets,** **and stray trailing octets)** **are displayed individually using LESSBINFMT so as to facilitate diagnostic** **of how the UTF-8 file is ill-formed.** **When the character set is utf-8, in rare cases it may be desirable to** **override the Unicode definition of the type of certain characters.** **For example, characters in a Private Use Area are normally treated as binary** **characters, but if you are using a custom font with printable characters** **in that range, it may be desirable to tell** **less** **to treat such characters as printable.** **This can be done by setting the LESSUTFCHARDEF environment variable** **to a comma-separated list of** *character type* **definitions.** **Each character type definition consists of either one hexadecimal codepoint** **or a pair of codepoints separated by a dash,** **followed by a colon and a type character.** **Each hexadecimal codepoint may optionally be preceded by a "U" or "U+".** **If a pair of codepoints is given, the type is set for** **all characters inclusively between the two values.** **If there are multiple comma-separated codepoint values,** **they must be in ascending numerical order.** **The type character may be one of:** - p **A normal printable character.** - w **A wide (2-space) printable character.** - b **A binary (non-printable) character.** - c **A composing (zero width) character.** - d **A deleted character (deleted from the input and not displayed).** **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.** **By default, emoji modifiers, components and variation selectors** **are deleted because many terminals do not display them correctly.** **If you use a terminal which does display some or all of them correctly,** **you can cause them to be displayed by setting LESSUTFCHARDEF** **to treat them as composing characters.** **For example, this sets them all to composing characters:** ``` FE00-FE0F:c,1F3FB-1F3FF:c,1F9B0-1F9B3:c,E0100-E01EF:c ``` ## PROMPTS **The** **-P** **option allows you to tailor the prompt to your preference.** **The string given to the** **-P** **option replaces the specified prompt string.** **Certain characters in the string are interpreted specially.** **The prompt mechanism is rather complicated to provide flexibility,** **but the ordinary user need not understand the details of constructing** **personalized prompt strings.** **A percent sign followed by a single character is expanded** **according to what the following character is.** **(References to the input file size below refer to the preprocessed size,** **if an input preprocessor is being used.)** - %b*X* **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 which appears in the first** **column of the screen.** - %C **Replaced by the column number of the text which appears (or would appear) in the last** **column of the screen.** - %d*X* **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 value of the VISUAL environment variable,** **or the EDITOR environment variable if VISUAL is not defined.** **See the usage example at 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.** - %G **Replaced by the shell-escaped 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.** - %l*X* **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.** - %p*X* **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.** - %P*X* **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.** - %Q **Replaced by the percent of the last column of text displayed on the screen** **compared to the length of the longest line currently displayed** **(that is, %C divided by %W).** **Note that using this sequence can make displaying the prompt be slower than usual.** - %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".** - %W **Replaced by the width of the longest line currently displayed on the screen.** **Note that using this sequence can make displaying the prompt be slower than usual.** - %x **Replaced by the name of the next input file in the list.** - %y **Replaced by the shell-escaped name of the next input file in the list.** - %% **Replaced by a single percent sign.** **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.** - ?b*X* **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 greater than 1).** - ?d*X* **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).** - ?l*X* **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.** - ?O **True if an OSC 8 hyperlink is selected.** - ?p*X* **True if the percent into the current input file, based on byte offsets,** **of the specified line is known.** - ?P*X* **True if the percent into the current input file, based on line numbers,** **of the specified line is known.** - ?Q **True if %Q is less than 100.** **Note that using this sequence can make displaying the prompt be slower than usual.** - ?s **Same as "?B".** - ?x **True if there is a next input file** **(that is, if the current input file is not the last one).** **Any characters other than the special ones** **(question mark, colon, period, percent, and backslash)** **become literally part of the prompt.** **Any of the special characters may be included in the prompt literally** **by preceding it with a backslash.** **Some examples:** ``` ?f%f:Standard input. ``` **This prompt prints the filename, if known;** **otherwise the string "Standard input".** ``` ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:-... ``` **This prompt would print the filename, if known.** **The filename is followed by the line number, if known,** **otherwise the percent if known, otherwise the byte offset if known.** **Otherwise, a dash is printed.** **Notice how each question mark has a matching period,** **and how the % after the %pt** **is included literally by escaping it with a backslash.** ``` ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x..%t ``` **This prints the filename if this is the first prompt in a file,** **followed by the "file N of N" message if there is more** **than one input file.** **Then, if we are at end-of-file, the string "(END)" is printed** **followed by the name of the next file, if there is one.** **Finally, any trailing spaces are truncated.** **This is the default prompt.** **For reference, here are the defaults for** **the other two prompts** **-m** **and** **-M** **respectively).** **Each is broken into two lines here for readability only.** ``` ?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\: %x.: ?pB%pB\%:byte %bB?s/%s...%t ``` **?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :**\ **byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..?c (column %c).%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\%..?c (column %c).%t ``` **The prompt expansion features are also used for another purpose:** **if an environment variable LESSEDIT is defined, it is used** **as the command to be executed when the v command is invoked.** **The LESSEDIT string is expanded in the same way as the prompt strings.** **The default value for LESSEDIT is:** ``` %E ?lm+%lm. %g ``` **Note that this expands to the editor name, followed by a + and the** **line number, followed by the shell-escaped file name.** **If your editor does not accept the "+linenumber" syntax, or has other** **differences in invocation syntax, the LESSEDIT variable can be** **changed to modify this default.** ## SECURITY **When the environment variable LESSSECURE is set to 1,** **less** **runs in a "secure" mode.** **In this mode, these features are disabled:** - edit **the edit command (v)** - examine **the examine command (:e)** - glob **metacharacters such as \* in filenames,**\ **and filename completion (TAB, ^L)** - history **history file** - lesskey **use of lesskey files, including the** **-k** **and** **--lesskey-src** **options, and all environment variables whose name begins with "LESSKEY"** - lessopen **input preprocessor (LESSOPEN environment variable)** - logfile **log files (s and** **-o**) - osc8 **opening OSC 8 links (^O^O)** - pipe **the pipe command (\|)** - shell **the shell and pshell commands (! and #)** - stop **stopping** **less** **via a SIGTSTP signal** - tags **use of tags files** (**-t**) **The LESSSECURE\_ALLOW environment variable can be set to a comma-separated list** **of names of features which are selectively enabled when LESSSECURE is set.** **Each feature name is the first word in each line in the above list.** **A feature name may be abbreviated as long as the abbreviation is unambiguous.** **For example, if** **LESSSECURE=1** **and** **LESSSECURE\_ALLOW=hist,edit** **were set, all of the above features would be disabled** **except for history files and the edit command.** **The LESSSECURE\_DISALLOW environment variable can be set to a comma-separated list** **of names of features which are selectively disabled when LESSSECURE is not set.** **Less can also be compiled to be permanently in "secure" mode.** **In that case, all of the above features are disabled,** **and the LESSSECURE, LESSSECURE\_ALLOW and LESSSECURE\_DISALLOW variables are ignored.** ## COMPATIBILITY WITH MORE **If the environment variable LESS\_IS\_MORE is set to 1,** **or if the program is invoked via a file link named "more"** **and the environment variable LESS\_IS\_MORE is not set to 0,** **less** **behaves (mostly) in conformance with the POSIX** [**more**(1)](/more/1.md) **command specification.** **In this mode,** **less** **behaves differently in these ways:** **The** **-e** **option works differently.** **If the** **-e** **option is not set,** **less** **behaves as if the** **-e** **option were set.** **If the** **-e** **option is set,** **less** **behaves as if the** **-E** **option were set.** **The** **-m** **option works differently.** **If the** **-m** **option is not set, the medium prompt is used,** **and it is prefixed with the string "--More--".** **If the** **-m** **option is set, the short prompt is used.** **The** **-n** **option acts like the** **-z** **option.** **The normal behavior of the** **-n** **option is unavailable in this mode.** **The parameter to the** **-p** **option is taken to be a** **less** **command rather than a search pattern.** **The LESS environment variable is ignored,** **and the MORE environment variable is used in its place.** ## ENVIRONMENT **Environment variables may be specified either in the system environment** **as usual, or in a** [**lesskey**(5)](/lesskey/5.md) **file.** **If environment variables are defined in more than one place,** **variables defined in a local lesskey file take precedence over** **variables defined in the system environment, which take precedence** **over variables defined in the system-wide lesskey file.** - COLUMNS **Sets the number of columns on the screen.** **Takes precedence over the number of columns specified by the TERM variable.** **(But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,** **the window system's idea of the screen size takes precedence over the** **LINES and COLUMNS environment variables.)** - EDITOR **The name of the editor (used for the v command).** - HOME **Name of the user's home directory** **(used to find a lesskey file on Unix and OS/2 systems).** - HOMEDRIVE, HOMEPATH **Concatenation of the HOMEDRIVE and HOMEPATH environment variables is** **the name of the user's home directory if the HOME variable is not set** **(only in the Windows version).** - INIT **Name of the user's init directory (used to find a lesskey file on OS/2 systems).** - LANG **Language for determining the character set.** - LC\_CTYPE **Language for determining the character set.** - LESS **Options which are passed to** **less** **automatically.** - LESSANSIENDCHARS **Characters which may end an ANSI color escape sequence** **(default "m").** - LESSANSIMIDCHARS **Characters which may appear between the ESC character and the** **end character in an ANSI color escape sequence** **(default "0123456789:;\[?!"'#%()\*+ ").** - LESSANSIOSCALLOW **A comma-separated list of OSC types which are output directly to the** **terminal when** **-R** **is in effect** **(default "8"; that is, only OSC 8 sequences are output directly).** - LESSANSIOSCCHARS **Characters which may follow an ESC character to mark the start** **of an "OS Command" sequence.** **All characters that follow this character up to a** **String Terminator (ESC-backslash or BEL)** **are considered to be part of the OSC sequence** **(default "\]").** **If a character in LESSANSIOSCCHARS is followed by an asterisk,** **sequences that begin with that character in the file contents** **are passed through to the terminal;** **otherwise only sequences that appear in a prompt string are passed through.** - LESSBINFMT **Format for displaying non-printable, non-control characters.** - LESSCHARDEF **Defines a character set.** - LESSCHARSET **Selects a predefined character set.** - LESSCLOSE **Command line to invoke the (optional) input-postprocessor.** - LESSECHO **Name of the lessecho program (default "lessecho").** **The lessecho program is needed to expand metacharacters, such as \* and ?,** **in filenames on Unix systems.** - LESSEDIT **Editor prototype string (used for the v command).** **See discussion under PROMPTS.** - LESSGLOBALTAGS **Name of the command used by the** **-t** **option to find global tags.** **Normally should be set to "global" if your system has the** [**global**(1)](/global/1.md) **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 (default "\\").** - LESSNOCONFIG **If set to "-", all environment variables except TERM are ignored** **(treated as if they were not set).** **If set to a comma-separated list of environment variable names,** **all environment variables except TERM and those in the list are ignored.** **In either case (if set to any non-empty value), all** **lesskey** **files are also ignored.** - 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.** - LESSSECURE\_DISALLOW **When LESSSECURE is not set, LESSSECURE\_DISALLOW can disable individual features.** **See discussion under SECURITY.** - LESSSEPARATOR **String to be appended to a directory name in filename completion** **(default "\\" on MS-DOS, Windows, and OS/2; otherwise "/").** - LESSUTFBINFMT **Format for displaying non-printable Unicode code points.** - LESSUTFCHARDEF **Overrides the type of specified Unicode characters.** - LESS\_COLUMNS **Sets the number of columns on the screen.** **Unlike COLUMNS, takes precedence over the system's idea of the screen size,** **so it can be used to make** **less** **use less than the full screen width.** **If set to a negative number, sets the number of columns used to** **this much less than the actual screen width.** - LESS\_LINES **Sets the number of lines on the screen.** **Unlike LINES, takes precedence over the system's idea of the screen size,** **so it can be used to make** **less** **use less than the full screen height.** **If set to a negative number, sets the number of lines used to** **this much less than the actual screen height.** **When set,** **less** **repaints the entire screen on every movement command,** **so scrolling may be slower.** - LESS\_DATA\_DELAY **Duration (in milliseconds) after starting to read data from the input,** **after which the "Waiting for data" message will be displayed.** **The default is 4000 (4 seconds).** - LESS\_IS\_MORE **Emulate the** [**more**(1)](/more/1.md) **command.** - LESSMSG **When set to the name of a** *lessmsg* **file, messages displayed by less are taken from that file.** **This can be used to translate** **less** **messages into another language.** **See the file** **lessmsg** **in the** **less** **distribution for more details.** - LESS\_OSC8\_OPEN\_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\_OPEN\_ANY **Sets an OSC 8 handler for opening OSC 8 links for which there is** **no specific LESS\_OSC8\_OPEN\_xxx handler set for the "xxx" scheme.** - LESS\_OSC8\_OPEN\_NONE **Sets an OSC 8 handler for opening OSC 8 links which contain no scheme** **(that is, there is no colon in the URI).** - LESS\_SHELL\_COPTION **Normally when executing a shell command** **cmd** **(via !, #, or \|, or a LESSOPEN command),** **if the SHELL environment variable is set, the command** **is invoked as "$SHELL -c cmd".** **If the LESS\_SHELL\_COPTION environment variable is set, its value** **is used instead of "-c" in that invocation.** **If LESS\_SHELL\_COPTION is set to a single dash,** **less** **acts as if SHELL were not set, and therefore invokes** **cmd** **directly.** - LESS\_SHELL\_LINES **When the** **-F** **option is set,** **less** **exits automatically if the number of screen lines used to display the file** **is less than or equal to the screen height minus the value of** **the LESS\_SHELL\_LINES variable.** **Thus, if you use a shell prompt which occupies more than one screen line,** **this variable can be set to the number of lines used by your prompt,** **to ensure that the entire file can be seen when** **-F** **is used.** **If not set, LESS\_SHELL\_LINES is assumed to be 1.** - LESS\_SIGUSR1 **If set to a string of one or more** **less** **command characters, those commands will be executed when** **less** **receives a SIGUSR1 signal.** - LESS\_TERMCAP\_xx **Where "xx" is any two characters, overrides the definition** **of the termcap "xx" capability for the terminal.** **No escape sequences in the string are processed, so any** **nonprintable characters such as ESC must be in the string literally.** - LESS\_TERMINFO\_xxxx **Where "xxxx" is any string of characters, overrides the definition** **of the terminfo "xxxx" capability for the terminal.** **You can use either LESS\_TERMCAP\_xx or LESS\_TERMINFO\_xxxx to override** **a terminal capability, regardless of whether** **less** **is built with the** **termcap** **or the** **terminfo** **library.** - LESS\_TERMCAP\_BRACKETED\_PASTE\_START **Overrides the standard ANSI escape sequence to enable bracketed paste.** **This is used when the** **--no-paste** **option is in effect.** - LESS\_TERMCAP\_BRACKETED\_PASTE\_END **Overrides the standard ANSI escape sequence to disable bracketed paste.** - LESS\_TERMCAP\_MOUSE\_START **Overrides the standard ANSI escape sequence to enable mouse reporting.** **This is used when the** **--mouse** **option is in effect.** - LESS\_TERMCAP\_MOUSE\_END **Overrides the standard ANSI escape sequence to disable mouse reporting.** - LESS\_TERMCAP\_SUSPEND **Defines an escape sequence to temporarily suspend screen updates.** **This is sent to the terminal before clearing the screen.** **This can be used to avoid screen tearing when the screen is redrawn** **on certain terminals.** - LESS\_TERMCAP\_RESUME **Defines an escape sequence to resume screen updates.** **This is sent to the terminal after displaying the prompt.** - LESS\_UNSUPPORT **A space-separated list of command line options.** **These options will be ignored (with no error message) if they appear** **on the command line or in the LESS environment variable.** **Options listed in LESS\_UNSUPPORT can still be changed by the - and -- commands.** **Each option in LESS\_UNSUPPORT is a dash followed by a single character** **option letter, or two dashes followed by a long option name.** - LINES **Sets the number of lines on the screen.** **Takes precedence over the number of lines specified by the TERM variable.** **(But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD,** **the window system's idea of the screen size takes precedence over the** **LINES and COLUMNS environment variables.)** - MORE **Options which are passed to** **less** **automatically when running in** **more**-compatible mode. - PATH **User's search path (used to find a lesskey file** **on MS-DOS, Windows, and OS/2 systems).** - POSIXLY\_CORRECT **If set to any value, all option arguments on the command line** **are expected to appear before any filename arguments.** **This must be set as an actual environment variable, not in a** **lesskey** **file.** - SHELL **The shell used to execute the ! command, as well as to expand filenames.** - TERM **The type of terminal on which** **less** **is being run.** - VISUAL **The name of the editor (used for the v command).** - XDG\_CONFIG\_HOME **Possible location of the** **lesskey** **file; see the KEY BINDINGS section.** - XDG\_DATA\_HOME **Possible location of the history file; see the description of the LESSHISTFILE environment variable.** - XDG\_STATE\_HOME **Possible location of the history file; see the description of the LESSHISTFILE environment variable.** ## SEE ALSO [**lesskey**(5)](/lesskey/5.md), [**lessecho**(1)](/lessecho/1.md) ## COPYRIGHT **Copyright (C) 1984-2026 Mark Nudelman** **less is part of the GNU project and is free software.** **You can redistribute it and/or modify it** **under the terms of either** **(1) the GNU General Public License as published by** **the Free Software Foundation; or (2) the Less License.** **See the file README in the less distribution for more details** **regarding redistribution.** **You should have received a copy of the GNU General Public License** **along with the source for less; see the file COPYING.** **If not, write to the Free Software Foundation, 59 Temple Place,** **Suite 330, Boston, MA 02111-1307, USA.** **You should also have received a copy of the Less License;** **see the file LICENSE.** **less is distributed in the hope that it will be useful, but** **WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY** **or FITNESS FOR A PARTICULAR PURPOSE.** **See the GNU General Public License for more details.** ## AUTHOR **Mark Nudelman**\ **Report bugs at** ⟨https://\\:github\\:.com/\\:gwsw/\\:less/\\:issues⟩. **For more information, see the** *less* **home page** ⟨https://\\:greenwoodsoftware\\:.com/\\:less⟩.