diff options
Diffstat (limited to 'less.man')
| -rw-r--r-- | less.man | 1257 |
1 files changed, 670 insertions, 587 deletions
@@ -25,11 +25,11 @@ terminals. (On a hardcopy terminal, lines which should be printed at the top of the screen are prefixed with a caret.) +[1mCOMMANDS[0m Commands are based on both [1mmore [22mand [1mvi[22m. Commands may be preceded by a decimal number, called N in the descriptions below. The number is used by some commands, as indicated. -[1mCOMMANDS[0m In the following descriptions, ^X means control‐X. ESC stands for the ESCAPE key; for example ESC‐v means the two character sequence "ES‐ CAPE", then "v". @@ -46,42 +46,50 @@ z Like SPACE, but if N is specified, it becomes the new window size. - ESC‐SPACE - Like SPACE, but scrolls a full screenful, even if it reaches - end‐of‐file in the process. - ENTER or RETURN or ^N or e or ^E or j or ^J - Scroll forward N lines, default 1. The entire N lines are dis‐ + Scroll forward N lines, default 1. The entire N lines are dis‐ played, even if N is more than the screen size. d or ^D Scroll forward N lines, default one half of the screen size. If - N is specified, it becomes the new default for subsequent d and + N is specified, it becomes the new default for subsequent d and u commands. b or ^B or ESC‐v - Scroll backward N lines, default one window (see option -z be‐ + Scroll backward N lines, default one window (see option -z be‐ low). If N is more than the screen size, only the final screen‐ ful is displayed. - w Like ESC‐v, but if N is specified, it becomes the new window + w Like ESC‐v, but if N is specified, it becomes the new window size. y or ^Y or ^P or k or ^K Scroll backward N lines, default 1. The entire N lines are dis‐ - played, even if N is more than the screen size. Warning: some + played, even if N is more than the screen size. Warning: some systems use ^Y as a special job control character. u or ^U - Scroll backward N lines, default one half of the screen size. - If N is specified, it becomes the new default for subsequent d + 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 + 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 be‐ + ginning of the file. + + ESC‐j Scroll forward N file lines, default 1. A file line is a com‐ + plete 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 be‐ @@ -234,24 +242,27 @@ ^S Followed by a digit N between 1 and 5. Only text which has a non‐empty match for the N‐th parenthesized SUB‐PAT‐ - TERN will be considered to match the pattern. (Supported - only if [1mless [22mis built with one of the regular expression - libraries [1mposix[22m, [1mpcre[22m, or [1mpcre2[22m.) Multiple ^S modifiers - can be specified, to match more than one sub‐pattern. + TERN will be considered to match the pattern. For exam‐ + ple, searching for "(abc)|(def)" modified with ^S1 would + search for instances of "abc", but would highlight in‐ + stances of both "abc" and "def". (Supported only if [1mless[0m + is built with one of the regular expression libraries + [1mposix[22m, [1mpcre[22m, or [1mpcre2[22m.) 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 + ^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 be‐ - comes part of the pattern even if it is one of the above + ^L The next character is taken literally; that is, it be‐ + comes 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 + 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: @@ -260,15 +271,15 @@ 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 + Search multiple files. That is, if the search reaches + the beginning of the current file without finding a + match, the search continues in the previous file in the command line list. ^F or @ Begin the search at the last line of the last file in the - command line list, regardless of what is currently dis‐ - played on the screen or the settings of the -a or -j op‐ + command line list, regardless of what is currently dis‐ + played on the screen or the settings of the -a or -j op‐ tions. ^K As in forward searches. @@ -277,53 +288,57 @@ ^S As in forward searches. - ^W WRAP around the current file. That is, if the search + ^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 + 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 pat‐ - tern. If the previous search was modified by ^N, the search is - made for the N‐th line NOT containing the pattern. If the pre‐ - vious search was modified by ^E, the search continues in the - next (or previous) file if not satisfied in the current file. - If the previous search was modified by ^R, the search is done - without using regular expressions. There is no effect if the - previous search was modified by ^F or ^K. + n Repeat previous search, for N‐th line containing the last pat‐ + tern. If the previous search was modified by ^N, the search is + made for the N‐th line NOT containing the pattern. If the pre‐ + vious 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 modi‐ + fied by ^F or ^K. N Repeat previous search, but in the reverse direction. - ESC‐n Repeat previous search, but crossing file boundaries. The ef‐ + ESC‐n Repeat previous search, but crossing file boundaries. The ef‐ fect is as if the previous search were modified by *. - ESC‐N Repeat previous search, but in the reverse direction and cross‐ + ESC‐N Repeat previous search, but in the reverse direction and cross‐ ing file boundaries. - ESC‐u Undo search highlighting. Turn off highlighting of strings + 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. + off because of a previous ESC‐u command, turn highlighting back + on. Any search command will also turn highlighting back on. (Highlighting can also be disabled by toggling the -G option; in that case search commands do not turn highlighting back on.) - ESC‐U Like ESC‐u but also clears the saved search pattern. If the - status column is enabled via the -J option, this clears all + ESC‐U Like ESC‐u but also clears the saved search pattern. If the + status column is enabled via the -J option, this clears all search matches marked in the status column. &pattern - Display only lines which match the pattern; lines which do not - match the pattern are not displayed. If pattern is empty (if - you type & immediately followed by ENTER), any filtering is - turned off, and all lines are displayed. While filtering is in - effect, an ampersand is displayed at the beginning of the + Display only lines which match the pattern; lines which do not + match the pattern are not displayed. If pattern is empty (if + you type & immediately followed by ENTER), any filtering is + turned off, and all lines are displayed. While filtering is in + effect, an ampersand is displayed at the beginning of the prompt, as a reminder that some lines in the file may be hidden. - Multiple & commands may be entered, in which case only lines + 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: @@ -331,81 +346,83 @@ ^N or ! Display only lines which do NOT match the pattern. - ^R Don’t interpret regular expression metacharacters; that + ^R Don’t interpret regular expression metacharacters; that is, do a simple textual comparison. :e [filename] - Examine a new file. If the filename is missing, the "current" - file (see the :n and :p commands below) from the list of files - in the command line is re‐examined. A percent sign (%) in the - filename is replaced by the name of the current file. A pound - sign (#) is replaced by the name of the previously examined - file. However, two consecutive percent signs are simply re‐ - placed 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. + Examine a new file. If the filename is missing, the "current" + file (see the :n and :p commands below) from the list of files + in the command line is re‐examined. A percent sign (%) in the + filename is replaced by the name of the current file. A pound + sign (#) is replaced by the name of the previously examined + file. However, two consecutive percent signs are simply re‐ + placed 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 + into the list of files and the first one is examined. If the filename contains one or more spaces, the entire filename should be enclosed in double quotes (also see the -" option). ^X^V or E - Same as :e. Warning: some systems use ^V as a special literal‐ - ization character. On such systems, you may not be able to use + Same as :e. Warning: some systems use ^V as a special literal‐ + ization character. On such systems, you may not be able to use ^V. - :n Examine the next file (from the list of files given in the com‐ - mand line). If a number N is specified, the N‐th next file is + :n Examine the next file (from the list of files given in the com‐ + mand line). If a number N is specified, the N‐th next file is examined. :p Examine the previous file in the command line list. If a number N is specified, the N‐th previous file is examined. - :x Examine the first file in the command line list. If a number N + :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 + 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 + T Go to the previous tag, if there were more than one matches for the current tag. ^O^N or ^On Search forward in the file for the N‐th next OSC 8 hyperlink. ^O^P or ^Op - Search backward in the file for the N‐th previous OSC 8 hyper‐ + Search backward in the file for the N‐th previous OSC 8 hyper‐ link. ^O^L or ^Ol Jump to the currently selected OSC 8 hyperlink. = or ^G or :f - Prints some information about the file being viewed, including - its name and the line number and byte offset of the bottom line - being displayed. If possible, it also prints the length of the - file, the number of lines in the file and the percent of the + Prints some information about the file being viewed, including + its name and the line number and byte offset of the bottom line + being displayed. If possible, it also prints the length of the + file, the number of lines in the file and the percent of the file above the last displayed line. - - Followed by one of the command line option letters (see OPTIONS - below), this will change the setting of that option and print a - message describing the new setting. If a ^P (CONTROL‐P) is en‐ - tered immediately after the dash, the setting of the option is - changed but no message is printed. If the option letter has a - numeric value (such as -b or -h), or a string value (such as -P - or -t), a new value may be entered after the option letter. If - no new value is entered, a message describing the current set‐ + - Followed by one of the command line option letters (see OPTIONS + below), this will change the setting of that option and print a + message describing the new setting. If a ^P (CONTROL‐P) is en‐ + tered immediately after the dash, the setting of the option is + changed but no message is printed. If the option letter has a + numeric value (such as -b or -h), or a string value (such as -P + or -t), a new value may be entered after the option letter. If + no new value is entered, a message describing the current set‐ ting is printed and nothing is changed. - -- Like the - command, but takes a long option name (see OPTIONS - below) rather than a single option letter. You must press ENTER - or RETURN after typing the option name. A ^P immediately after - the second dash suppresses printing of a message describing the - new setting, as in the - command. + -- Like the - command, but takes a long option name (see OPTIONS + below) rather than a single option letter. Press ENTER or RE‐ + TURN 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 af‐ + ter the second dash suppresses printing of a message describing + the new setting, as in the - command. -+ Followed by one of the command line option letters this will re‐ set the option to its default setting and print a message de‐ @@ -455,8 +472,8 @@ (%) in the command is replaced by the name of the current file. A pound sign (#) is replaced by the name of the previously exam‐ ined file. "!!" repeats the last shell command. "!" with no - shell command simply invokes a shell. If a ^P (CONTROL‐P) is - entered immediately after the !, no "done" message is printed + 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 @@ -557,12 +574,12 @@ 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 un‐ - ambiguous. For example, --quit‐at‐eof may be abbreviated --quit, but - not --qui, since both --quit‐at‐eof and --quiet begin with --qui. Some - long option names are in uppercase, such as --QUIT‐AT‐EOF, as distinct - from --quit‐at‐eof. Such option names need only have their first let‐ - ter capitalized; the remainder of the name may be in either case. For - example, --Quit‐at‐eof is equivalent to --QUIT‐AT‐EOF. + ambiguous. 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 ex‐ + ample, --Quit‐at‐eof is equivalent to --QUIT‐AT‐EOF. Options are also taken from the environment variable "LESS". For exam‐ ple, to avoid typing "less -options ..." each time [1mless [22mis invoked, you @@ -574,77 +591,77 @@ 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 inter‐ + 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 inter‐ preted as an environment variable expansion. - The environment variable is parsed before the command line, so command - line options override the LESS environment variable. If an option ap‐ + The environment variable is parsed before the command line, so command + line options override the LESS environment variable. If an option ap‐ pears in the LESS variable, it can be reset to its default value on the command line by beginning the command line option with "-+". - Some options like -k or -D require a string to follow the option let‐ - ter. The string for that option is considered to end when a dollar + Some options like -k or -D require a string to follow the option let‐ + ter. 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 + 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 + 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 [1mless[0m - (the same as the h command). (Depending on how your shell in‐ - terprets the question mark, it may be necessary to quote the + This option displays a summary of the commands accepted by [1mless[0m + (the same as the h command). (Depending on how your shell in‐ + terprets 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 dis‐ - played screen (except for repeated searches invoked by the n or - N commands, which start after or before the "target" line re‐ - spectively; 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 + By default, forward searches start at the top of the displayed + screen and backwards searches start at the bottom of the dis‐ + played screen (except for repeated searches invoked by the n or + N commands, which start after or before the "target" line re‐ + spectively; see the -j option for more about the target line). + The -a option causes forward searches to instead start at the + bottom of the screen and backward searches to start at the top of the screen, thus skipping all lines displayed on the screen. -A or --SEARCH‐SKIP‐SCREEN - Causes all forward searches (not just non‐repeated searches) to - start just after the target line, and all backward searches to - start just before the target line. Thus, forward searches will + Causes all forward searches (not just non‐repeated searches) to + start just after the target line, and all backward searches to + start just before the target line. Thus, forward searches will skip part of the displayed screen (from the first line up to and - including the target line). Similarly backwards searches will + 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[4mn[24m or --buffers=[4mn[0m - Specifies the amount of buffer space [1mless [22mwill 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 [4mn[0m + Specifies the amount of buffer space [1mless [22mwill 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 [4mn[0m kilobytes of buffer space should be used for each file. If [4mn[24m is - -1, buffer space is unlimited; that is, the entire file can be + -1, buffer space is unlimited; that is, the entire file can be read into memory. -B or --auto‐buffers By default, when data is read from a pipe, buffers are allocated automatically as needed. If a large amount of data is read from - the pipe, this can cause a large amount of memory to be allo‐ - cated. The -B option disables this automatic allocation of - buffers for pipes, so that only 64 KB (or the amount of space - specified by the -b option) is used for the pipe. Warning: use - of -B can result in erroneous display, since only the most re‐ + the pipe, this can cause a large amount of memory to be allo‐ + cated. The -B option disables this automatic allocation of + buffers for pipes, so that only 64 KB (or the amount of space + specified by the -b option) is used for the pipe. Warning: use + of -B can result in erroneous display, since only the most re‐ cently viewed part of the piped data is kept in memory; any ear‐ - lier data is lost. Lost characters are displayed as question + lier data is lost. Lost characters are displayed as question marks. -c or --clear‐screen - Causes full screen repaints to be painted from the top line - down. By default, full screen repaints are done by scrolling + 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 @@ -652,13 +669,13 @@ -d or --dumb The -d option suppresses the error message normally displayed if - the terminal is dumb; that is, lacks some important capability, + 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 [1mless [22mon a + -d option does not otherwise change the behavior of [1mless [22mon a dumb terminal. -D[1mx[4m[22mcolor[24m or --color=[1mx[4m[22mcolor[0m - Changes the color of different parts of the displayed text. [1mx[0m + Changes the color of different parts of the displayed text. [1mx[0m is a single character which selects the type of text whose color is being set: @@ -682,7 +699,7 @@ W The highlight enabled via the -w option. - 1‐5 The text in a search result which matches the first + 1‐5 The text in a search result which matches the first through fifth parenthesized sub‐pattern. Sub‐pattern coloring works only if [1mless [22mis built with one of the reg‐ ular expression libraries [1mposix[22m, [1mpcre[22m, or [1mpcre2[22m. @@ -695,30 +712,30 @@ 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 nor‐ - mally displayed as standout text. So if both "s" and "E" are - given a color, the "E" color applies to error messages, and the + 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 nor‐ + mally 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 + 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 + 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 with‐ - out underlining; the green color has replaced the usual under‐ - line formatting. But -Du+g displays underlined text as both + out underlining; the green color has replaced the usual under‐ + line formatting. But -Du+g displays underlined text as both green and in underlined format. [4mcolor[24m 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 speci‐ + A 4‐bit color string is one or two characters, where the first + character specifies the foreground color and the second speci‐ fies the background color as follows: b Blue @@ -737,24 +754,24 @@ y Yellow - The corresponding uppercase letter denotes a brighter shade of - the color. For example, -DNGk displays line numbers as bright - green text on a black background, and -DEbR displays error mes‐ - sages as blue text on a bright red background. If either char‐ - acter is a "‐" or is omitted, the corresponding color is set to + The corresponding uppercase letter denotes a brighter shade of + the color. For example, -DNGk displays line numbers as bright + green text on a black background, and -DEbR displays error mes‐ + sages as blue text on a bright red background. If either char‐ + acter 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 + 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" + and the second specifies the background color. Each integer is + a value between 0 and 255 inclusive which selects a "CSI 38;5" color value (see - https://en.wikipedia.org/wiki/ANSI_escape_code#SGR). If either - integer is a "‐" or is omitted, the corresponding color is set - to that of normal text. + ⟨https://en.wikipedia.org/wiki/ANSI_escape_code#SGR⟩). If ei‐ + ther 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 + 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) @@ -765,48 +782,48 @@ l or & Blinking - On MS‐DOS and Windows, the --color option behaves differently + On MS‐DOS and Windows, the --color option behaves differently from what is described above in these ways: • The bold (d and *) and blinking (l and &) text attributes at the end of a color string are not supported. - • Lowercase color selector letters refer to text formatted - by ANSI escape sequences with -R, in addition to over‐ + • Lowercase color selector letters refer to text formatted + by ANSI escape sequences with -R, in addition to over‐ struck and non‐content text (but see -Da). - • For historical reasons, when a lowercase color selector - letter is followed by a numeric color value, the number - is not interpreted as an "CSI 38;5" color value as de‐ - scribed above, but instead as a 4‐bit - CHAR_INFO.Attributes value, between 0 and 15 inclusive - (see https://learn.microsoft.com/en‐ - us/windows/console/char‐info‐str). + • 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 de‐ + scribed above, but instead as a 4‐bit + CHAR_INFO.Attributes value, between 0 and 15 inclusive + (see ⟨https://learn.microsoft.com/en‐ + us/windows/console/char‐info‐str⟩). To avoid confusion, it is recommended that the equivalent - letters rather than numbers be used after a lowercase + letters rather than numbers be used after a lowercase color selector on MS‐DOS/Windows. - • Numeric color values ("CSI 38;5" color) following an up‐ - percase color selector letter are not supported on sys‐ + • Numeric color values ("CSI 38;5" color) following an up‐ + percase color selector letter are not supported on sys‐ tems earlier than Windows 10. - • Only a limited set of ANSI escape sequences to set color - in the content work correctly. 4‐bit color sequences + • Only a limited set of ANSI escape sequences to set color + in the content work correctly. 4‐bit color sequences work, but "CSI 38;5" color sequences do not. • The -Da option makes the behavior of --color more similar to its behavior on non‐MS‐DOS/Windows systems by (1) mak‐ ing lowercase color selector letters not affect text for‐ - matted with ANSI escape sequences, and (2) allowing "CSI + matted with ANSI escape sequences, and (2) allowing "CSI 38;5" color sequences in the content work by passing them to the terminal (only on Windows 10 and later; on earlier Windows systems, such sequences do not work regardless of the setting of -Da). -e or --quit‐at‐eof - Causes [1mless [22mto automatically exit the second time it reaches - end‐of‐file. By default, the only way to exit [1mless [22mis via the + Causes [1mless [22mto automatically exit the second time it reaches + end‐of‐file. By default, the only way to exit [1mless [22mis via the "q" command. -E or --QUIT‐AT‐EOF @@ -815,14 +832,15 @@ -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 warn‐ + directory or a device special file.) Also suppresses the warn‐ ing message when a binary file is opened. By default, [1mless [22mwill refuse to open non‐regular files. Note that some operating sys‐ tems will not allow directories to be read, even if -f is set. -F or --quit‐if‐one‐screen Causes [1mless [22mto automatically exit if the entire file can be dis‐ - played on the first screen. + played on the first screen. Also see the description of the + LESS_SHELL_LINES environment variable below. -g or --hilite‐search Normally, [1mless [22mwill highlight ALL strings which match the last @@ -868,87 +886,85 @@ 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. While the --header option is ac‐ - tive, the -S option is ignored, and lines longer than the screen - width are truncated. + 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 + 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 + nonrepeated searches (invoked with "/" or "?") always begin at the start or end of the current screen respectively. -J or --status‐column - Displays a status column at the left edge of the screen. The + Displays a status column at the left edge of the screen. The character displayed in the status column may be one of: > The line is chopped with the -S option, and the text that - is chopped off beyond the right edge of the screen con‐ + is chopped off beyond the right edge of the screen con‐ tains a match for the current search. - < The line is horizontally shifted, and the text that is - shifted beyond the left side of the screen contains a + < 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 + = 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 + * There are matches in the visible part of the line but none to the right or left of it. a‐z, A‐Z - The line has been marked with the corresponding letter - via the m command. + The line has been marked with the corresponding letter + via the m or M command. -k[4mfilename[24m or --lesskey‐file=[4mfilename[0m Causes [1mless [22mto open and interpret the named file as a [1mlesskey[22m(1) - binary file. Multiple -k options may be specified. If the - LESSKEY or LESSKEY_SYSTEM environment variable is set, or if a + 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 [1mlesskey [22mfile. Note the warning under + is also used as a [1mlesskey [22mfile. Note the warning under "--lesskey‐content" below. --lesskey‐src=[4mfilename[0m Causes [1mless [22mto open and interpret the named file as a [1mlesskey[22m(1) - source file. If the LESSKEYIN or LESSKEYIN_SYSTEM environment + source file. If the LESSKEYIN or LESSKEYIN_SYSTEM environment variable is set, or if a lesskey source file is found in a stan‐ - dard place (see KEY BINDINGS), it is also used as a [4mlesskey[0m - [4msource[24m file. Prior to version 582, the [1mlesskey [22mprogram needed - to be run to convert a [4mlesskey[24m [4msource[24m file to a [4mlesskey[24m [4mbinary[0m - file for [1mless [22mto use. Newer versions of [1mless [22mread the [4mlesskey[0m - [4msource[24m file directly and ignore the binary file if the source + dard place (see KEY BINDINGS), it is also used as a lesskey + source file. Prior to version 582, the [1mlesskey [22mprogram needed + to be run to convert a lesskey [4msource[24m file to a lesskey [4mbinary[0m + file for [1mless [22mto use. Newer versions of [1mless [22mread the lesskey + source file directly and ignore the binary file if the source file exists. Note the warning under "--lesskey‐content" below. --lesskey‐content=[4mtext[0m - Causes less to interpret the specified text as the contents of a + Causes [1mless [22mto interpret the specified text as the contents of a [1mlesskey[22m(1) source file. In the text, [1mlesskey [22mlines may be sepa‐ - rated by either newlines as usual, or by semicolons. A literal - semicolon may be represented by a backslash followed by a semi‐ + rated by either newlines as usual, or by semicolons. A literal + semicolon may be represented by a backslash followed by a semi‐ colon. Warning: certain environment variables such as LESS, LESSSECURE, - LESSCHARSET and others, which are used early in startup, cannot - be set in a file specified by a command line option (--lesskey, - --lesskey‐src or --lesskey‐content). When using a [1mlesskey [22mfile - 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 com‐ + 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 [1mlesskey [22mfile + 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 com‐ mand line option. -K or --quit‐on‐intr - Causes [1mless [22mto exit immediately (with status 2) when an inter‐ - rupt character (usually ^C) is typed. Normally, an interrupt + Causes [1mless [22mto exit immediately (with status 2) when an inter‐ + rupt character (usually ^C) is typed. Normally, an interrupt character causes [1mless [22mto stop whatever it is doing and return to - its command prompt. Note that use of this option makes it im‐ + its command prompt. Note that use of this option makes it im‐ possible to return to the command prompt from the "F" command. -L or --no‐lessopen - Ignore the LESSOPEN environment variable (see the INPUT PRE‐ - PROCESSOR section below). This option can be set from within - [1mless[22m, but it will apply only to files opened subsequently, not + Ignore the LESSOPEN environment variable (see the INPUT PRE‐ + PROCESSOR section below). This option can be set from within + [1mless[22m, but it will apply only to files opened subsequently, not to the file which is currently open. -m or --long‐prompt @@ -959,14 +975,12 @@ Causes [1mless [22mto prompt even more verbosely than [1mmore[22m(1). -n or --line‐numbers - Suppresses line numbers. The default (to use line numbers) may - cause [1mless [22mto run more slowly in some cases, especially with a - very large input file. Suppressing line numbers with the -n op‐ - tion will avoid this problem. Using line numbers means: the - line number will be displayed in the verbose prompt and in the = - command, and the v command will pass the current line number to - the editor (see also the discussion of LESSEDIT in PROMPTS be‐ - low). + Suppresses line numbers. The default (to use line numbers) may + cause [1mless [22mto run more slowly in some cases, especially with a + very large input file. Using line numbers means: the line num‐ + ber will be displayed in the verbose prompt and in the = com‐ + mand, and the v command will pass the current line number to the + editor (see also the discussion of LESSEDIT in PROMPTS below). -N or --LINE‐NUMBERS Causes a line number to be displayed at the beginning of each @@ -1034,51 +1048,67 @@ play problems may result, such as long lines being split in the wrong place. - USE OF THE -r OPTION IS NOT RECOMMENDED. + USE OF THE -r OPTION IS DANGEROUS AND IS NOT RECOMMENDED. + The -r option can be set on the command line or via the - com‐ + mand, but to avoid unintentional use, it cannot be set in a LESS + environment variable. If -r appears in a LESS environment vari‐ + able, it is treated as if it were -R. -R or --RAW‐CONTROL‐CHARS - Like -r, but only ANSI "color" escape sequences and OSC 8 hyper‐ - link sequences are output in "raw" form. Unlike -r, the screen - appearance is maintained correctly, provided that there are no - escape sequences in the file other than these types of escape - sequences. Color escape sequences are only supported when the - color is changed within one line, not across lines. In other - words, the beginning of each line is assumed to be normal (non‐ - colored), regardless of any escape sequences in previous lines. - For the purpose of keeping track of screen appearance, these es‐ - cape sequences are assumed to not move the cursor. + 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 - OSC 8 hyperlinks are sequences of the form: + 2. OSC 8 hyperlinks - ESC ] 8 ; ... \7 + 3. Other OSC sequences, if the OSC type number is listed in the + LESSANSIOSCALLOW environment variable - The terminating sequence may be either a BEL character (\7) or - the two‐character sequence "ESC \". + 4. OSC sequences starting with a non‐standard introductory char‐ + acter (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. - You can make [1mless [22mthink that characters other than "m" can end - ANSI color escape sequences by setting the environment variable + 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 [1mless [22mthink 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 [1mless [22mthink that characters - other than the standard ones may appear between the ESC and the - m by setting the environment variable LESSANSIMIDCHARS to the + escape sequence. And you can make [1mless [22mthink 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 terminat‐ + ing 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 [1mnroff [22moutput. + Causes consecutive blank lines to be squeezed into a single + blank line. This is useful when viewing [1mnroff[22m(1) output. -S or --chop‐long‐lines - Causes lines longer than the screen width to be chopped (trun‐ + Causes lines longer than the screen width to be chopped (trun‐ cated) 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, + press RIGHT‐ARROW. The default is to wrap long lines; that is, display the remainder on the next line. See also the --wordwrap - option. + option. While the --header option is active, the -S option is + ignored, and lines longer than the screen width are truncated. -t[4mtag[24m or --tag=[4mtag[0m The -t option, followed immediately by a TAG, will edit the file @@ -1088,7 +1118,7 @@ an equivalent command. If the environment variable LESSGLOBALT‐ AGS is set, it is taken to be the name of a command compatible with [1mglobal[22m(1), and that command is executed to find the tag. - (See http://www.gnu.org/software/global/global.html). The -t + (See ⟨http://www.gnu.org/software/global/global.html⟩). The -t option may also be specified from within [1mless [22m(using the - com‐ mand) as a way of examining a new file. The command ":t" is equivalent to specifying -t from within [1mless[22m. @@ -1111,12 +1141,12 @@ the underlined text is displayed using the terminal’s hardware underlining capability. Also, backspaces which appear between two identical characters are treated specially: the overstruck - text is printed using the terminal’s hardware boldface capabili‐ - ty. Other backspaces are deleted, along with the preceding - character. Carriage returns immediately followed by a newline + text is printed using the terminal’s hardware boldface capabil‐ + ity. 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 + 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 ef‐ fect. @@ -1127,14 +1157,14 @@ Displays the version number of [1mless[22m. -w or --hilite‐unread - Temporarily highlights the first "new" line after a forward + Temporarily highlights the first "new" line after a forward movement of a full page. The first "new" line is the line imme‐ - diately following the line previously at the bottom of the + diately 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 move‐ + The highlight is removed at the next command which causes move‐ ment. 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 ef‐ + (the width of the screen) is highlighted. Otherwise, only the + text in the line is highlighted, unless the -J option is in ef‐ fect, in which case only the status column is highlighted. -W or --HILITE‐UNREAD @@ -1142,48 +1172,48 @@ forward movement command larger than one line. -x[4mn[24m,... or --tabs=[4mn[24m,... - Sets tab stops. If only one [4mn[24m is specified, tab stops are set - at multiples of [4mn[24m. If multiple values separated by commas are - specified, tab stops are set at those positions, and then con‐ - tinue with the same spacing as the last two. For example, + Sets tab stops. If only one [4mn[24m is specified, tab stops are set + at multiples of [4mn[24m. If multiple values separated by commas are + specified, tab stops are set at those positions, and then con‐ + tinue with the same spacing as the last two. For example, "‐x9,17" will set tabs at positions 9, 17, 25, 33, etc. The de‐ fault for [4mn[24m is 8. -X or --no‐init Disables sending the termcap initialization and deinitialization - strings to the terminal. This is sometimes desirable if the - deinitialization string does something unnecessary, like clear‐ + strings to the terminal. This is sometimes desirable if the + deinitialization string does something unnecessary, like clear‐ ing the screen. -y[4mn[24m or --max‐forw‐scroll=[4mn[0m Specifies a maximum number of lines to scroll forward. If it is necessary to scroll forward more than [4mn[24m lines, the screen is re‐ - painted instead. The -c or -C option may be used to repaint - from the top of the screen if desired. By default, any forward + painted 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[4mn[24m or --window=[4mn[24m or -[4mn[0m - Changes the default scrolling window size to [4mn[24m lines. The de‐ - fault is one screenful. The z and w commands can also be used - to change the window size. The "z" may be omitted for compati‐ - bility with some versions of [1mmore[22m(1). If the number [4mn[24m is nega‐ - tive, it indicates [4mn[24m lines less than the current screen size. - For example, if the screen is 24 lines, [4m-z-4[24m sets the scrolling - window to 20 lines. If the screen is resized to 40 lines, the + Changes the default scrolling window size to [4mn[24m lines. The de‐ + fault is one screenful. The z and w commands can also be used + to change the window size. The "z" may be omitted for compati‐ + bility with some versions of [1mmore[22m(1). If the number [4mn[24m is nega‐ + tive, it indicates [4mn[24m lines less than the current screen size. + For example, if the screen is 24 lines, [4m-z-4[24m sets the scrolling + window to 20 lines. If the screen is resized to 40 lines, the scrolling window automatically changes to 36 lines. -"[4mcc[24m or --quotes=[4mcc[0m - 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 + 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 + 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 + 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 @@ -1193,60 +1223,69 @@ -# or --shift Specifies the default number of positions to scroll horizontally - in the RIGHTARROW and LEFTARROW commands. If the number speci‐ - fied is zero, it sets the default number of positions to one + in the RIGHTARROW and LEFTARROW commands. If the number speci‐ + fied is zero, it sets the default number of positions to one half of the screen width. Alternately, the number may be speci‐ - fied 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 speci‐ + fied 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 speci‐ fied as a fraction, the actual number of scroll positions is re‐ calculated if the terminal window is resized. --exit‐follow‐on‐close - When using the "F" command on a pipe, [1mless [22mwill automatically - stop waiting for more data when the input side of the pipe is + When using the "F" command on a pipe, [1mless [22mwill automatically + stop waiting for more data when the input side of the pipe is closed. --file‐size If --file‐size is specified, [1mless [22mwill determine the size of the - file immediately after opening the file. Then the "=" command - will display the number of lines in the file. Normally this is - not done, because it can be slow if the input file is non‐seek‐ + file immediately after opening the file. Then the "=" command + will display the number of lines in the file. Normally this is + not done, because it can be slow if the input file is non‐seek‐ able (such as a pipe) and is large. --follow‐name Normally, if the input file is renamed while an F command is ex‐ ecuting, [1mless [22mwill continue to display the contents of the orig‐ - inal file despite its name change. If --follow‐name is speci‐ - fied, during an F command [1mless [22mwill periodically attempt to re‐ + inal file despite its name change. If --follow‐name is speci‐ + fied, during an F command [1mless [22mwill periodically attempt to re‐ open 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 re‐ + different file from the original (which means that a new file + has been created with the same name as the original (now re‐ named) file), [1mless [22mwill 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=[4mL[24m,[4mC[24m,[4mN[0m Sets the number of header lines and columns displayed on the screen. The number of header lines is set to [4mL[24m. If [4mL[24m is 0, header lines are disabled. If [4mL[24m is empty or missing, the number of header lines is unchanged. The number of header columns is - set to [4mC[24m. If [4mC[24m is 0, header columns are disabled. If [4mC[24m is emp‐ - ty or missing, the number of header columns is unchanged. The - first header line is set to line number [4mN[24m in the file. If [4mN[24m is - empty or missing, it is taken to be the number of the line cur‐ - rently displayed in the first line of the screen (if the --head‐ - er command has been issued from within [1mless[22m), or 1 (if the + set to [4mC[24m. If [4mC[24m is 0, header columns are disabled. If [4mC[24m is + empty or missing, the number of header columns is unchanged. + The first header line is set to line number [4mN[24m in the file. If [4mN[0m + 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 [1mless[22m), or 1 (if the --header option has been given on the command line). The spe‐ cial form "--header=-" disables header lines and header columns, and is equivalent to "--header=0,0". When [4mL[24m is nonzero, the first [4mL[24m lines at the top of the screen are replaced with the [4mL[24m lines of the file beginning at line [4mN[24m, - regardless of what part of the file is being viewed. When head‐ - er lines are displayed, any file contents before the header line - cannot be viewed. When [4mC[24m is nonzero, the first [4mC[24m characters - displayed at the beginning of each line are replaced with the - first [4mC[24m characters of the line, even if the rest of the line is - scrolled horizontally. + 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 [4mC[24m is nonzero, the first [4mC[24m charac‐ + ters displayed at the beginning of each line are replaced with + the first [4mC[24m characters of the line, even if the rest of the line + is scrolled horizontally. + + While the --header option is active, lines longer than the + screen width are truncated, and the -S option is ignored. --incsearch Subsequent search commands will be "incremental"; that is, [1mless[0m @@ -1303,12 +1342,13 @@ ward in the file, scrolling the mouse wheel up moves backwards in the file, left‐click sets the "#" mark to the line where the mouse is clicked, and right‐click (or any other) returns to the - "#" mark position. If a left‐click is performed with the mouse - cursor on an OSC 8 hyperlink, the hyperlink is selected as if by - the ^O^N command. If a left‐click is performed with the mouse - cursor on an OSC 8 hyperlink which is already selected, the hy‐ - perlink is opened as if by the ^O^O command. The number of - lines to scroll when the wheel is moved can be set by the + "#" mark position. Holding down the left button and dragging + also moves in the file. If a left‐click is performed with the + mouse cursor on an OSC 8 hyperlink, the hyperlink is selected as + if by the ^O^N command. If a left‐click is performed with the + mouse cursor on an OSC 8 hyperlink which is already selected, + the hyperlink is opened as if by the ^O^O command. The number + of lines to scroll when the wheel is moved can be set by the --wheel‐lines option. Mouse input works only on terminals which support X11 mouse reporting, and on the Windows version of [1mless[22m. @@ -1316,6 +1356,11 @@ Like --mouse, except the direction scrolled on mouse wheel move‐ ment is reversed. + --no‐edit‐warn + Don’t print a warning message when using the v command on a file + which was opened using a LESSOPEN preprocessor (see the INPUT + PREPROCESSOR section below). + --no‐keypad Disables sending the keypad initialization and deinitialization strings to the terminal. This is sometimes useful if the keypad @@ -1334,6 +1379,14 @@ 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 [1mless [22mis 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. @@ -1379,7 +1432,7 @@ 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 dis‐ - play is controlled by the -U options. + play is controlled by the -U option. --PROC‐TAB If set, tabs are handled as if the -U option were set; that is @@ -1438,8 +1491,8 @@ Enables colored text in various places. The -D option can be used to change the colors. Colored text works only if the ter‐ minal supports ANSI color escape sequences (as defined in - https://www.ecma‐international.org/publications‐and‐ - standards/standards/ecma‐48). + ⟨https://www.ecma‐international.org/publications‐and‐ + standards/standards/ecma‐48⟩). --wheel‐lines=[4mn[0m Set the number of lines to scroll when the mouse wheel is @@ -1474,7 +1527,7 @@ certain keys can be used to manipulate the command line. Most commands have an alternate form in [ brackets ] which can be used if a key does not exist on a particular keyboard. (Note that the forms beginning - with ESC do not work in some MS‐DOS and Windows systems because ESC is + 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 @@ -1544,84 +1597,84 @@ ^U (Unix and OS/2) or ESC (MS‐DOS and Windows) Delete the entire command line, or cancel the command if the - command line is empty. If you have changed your line‐kill char‐ - acter in Unix to something other than ^U, that character is used - instead of ^U. + 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. [1mKEY BINDINGS[0m - You may define your own [1mless [22mcommands by creating a lesskey source - file. This file specifies a set of command keys and an action associ‐ - ated with each key. You may also change the line‐editing keys (see - LINE EDITING), and set environment variables used by [1mless[22m. See the + You may define your own [1mless [22mcommands by creating a lesskey source + file. This file specifies a set of command keys and an action associ‐ + ated with each key. You may also change the line‐editing keys (see + LINE EDITING), and set environment variables used by [1mless[22m. See the [1mlesskey[22m(1) manual page for details about the file format. - If the environment variable LESSKEYIN is set, [1mless [22muses that as the - name of the lesskey source file. Otherwise, [1mless [22mlooks in a standard - place for the lesskey source file: On Unix systems, [1mless [22mlooks for a - lesskey file called "$XDG_CONFIG_HOME/lesskey" or "$HOME/.con‐ - fig/lesskey" or "$HOME/.lesskey". On MS‐DOS and Windows systems, [1mless[0m - looks for a lesskey file called "$HOME/_lesskey", and if it is not + If the environment variable LESSKEYIN is set, [1mless [22muses that as the + name of the lesskey source file. Otherwise, [1mless [22mlooks in a standard + place for the lesskey source file: On Unix systems, [1mless [22mlooks for a + lesskey file called "$XDG_CONFIG_HOME/lesskey" or "$HOME/.con‐ + fig/lesskey" or "$HOME/.lesskey". On MS‐DOS and Windows systems, [1mless[0m + looks for a lesskey file called "$HOME/_lesskey", and if it is not found there, then looks for a lesskey file called "_lesskey" in any di‐ - rectory specified in the PATH environment variable. On OS/2 systems, - [1mless [22mlooks for a lesskey file called "$HOME/lesskey.ini", and if it is - not found, then looks for a lesskey file called "lesskey.ini" in any - directory specified in the INIT environment variable, and if it not - found there, then looks for a lesskey file called "lesskey.ini" in any + rectory specified in the PATH environment variable. On OS/2 systems, + [1mless [22mlooks for a lesskey file called "$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, [1mless [22muses that as the name of the system‐wide - lesskey file. Otherwise, [1mless [22mlooks in a standard place for the sys‐ + 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, [1mless [22muses that as the name of the system‐wide + lesskey file. Otherwise, [1mless [22mlooks in a standard place for the sys‐ tem‐wide lesskey file: On Unix systems, the system‐wide lesskey file is - /usr/local/etc/syslesskey. (However, if [1mless [22mwas built with a differ‐ - ent sysconf directory than /usr/local/etc, that directory is where the + /usr/local/etc/syslesskey. (However, if [1mless [22mwas built with a differ‐ + ent 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. On OS/2 systems, the system‐wide lesskey file is c:\syslesskey.ini. - Previous versions of [1mless [22m(before v582) used lesskey files with a bina‐ - ry format, produced by the [1mlesskey [22mprogram. It is no longer necessary - to use the [1mlesskey [22mprogram. + Older versions of [1mless [22m(before v582) used lesskey files with a binary + format, produced by the [1mlesskey [22mprogram. It is no longer necessary to + use the [1mlesskey [22mprogram. [1mINPUT PREPROCESSOR[0m You may define an "input preprocessor" for [1mless[22m. Before [1mless [22mopens a - file, it first gives your input preprocessor a chance to modify the way - the contents of the file are displayed. An input preprocessor is sim‐ - ply an executable program (or shell script), which writes the contents + file, it first gives the input preprocessor a chance to modify the way + the contents of the file are displayed. An input preprocessor is sim‐ + ply an executable program (or shell script), which writes the contents of the file to a different file, called the replacement file. The con‐ - tents of the replacement file are then displayed in place of the con‐ - tents of the original file. However, it will appear to the user as if - the original file is opened; that is, [1mless [22mwill display the original + tents of the replacement file are then displayed in place of the con‐ + tents of the original file. However, it will appear to the user as if + the original file is opened; that is, [1mless [22mwill display the original filename as the name of the current file. - An input preprocessor receives one command line argument, the original - filename, as entered by the user. It should create the replacement - file, and when finished, print the name of the replacement file to its - standard output. If the input preprocessor does not output a replace‐ - ment filename, [1mless [22muses the original file, as normal. The input pre‐ - processor is not called when viewing standard input. To set up an in‐ - put 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 re‐ + An input preprocessor receives one command line argument, the original + filename, as entered by the user. It should create the replacement + file, and when finished, print the name of the replacement file to its + standard output. If the input preprocessor does not output a replace‐ + ment filename, [1mless [22muses the original file, as normal. The input pre‐ + processor is not called when viewing standard input. To set up an in‐ + put 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 re‐ placed by the filename when the input preprocessor command is invoked. When [1mless [22mcloses a file opened in such a way, it will call another pro‐ - gram, called the input postprocessor, which may perform any desired - clean‐up action (such as deleting the replacement file created by + gram, called the input postprocessor, which may perform any desired + clean‐up action (such as deleting the replacement file created by LESSOPEN). This program receives two command line arguments, the orig‐ - inal 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 re‐ - placed with the original name of the file and the second with the name + inal 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 re‐ + placed with the original name of the file and the second with the name of the replacement file, which was output by LESSOPEN. - For example, on many Unix systems, these two scripts will allow you to + For example, on many Unix systems, these two scripts will allow you to keep files in compressed format, but still let [1mless [22mview them directly: lessopen.sh: @@ -1641,27 +1694,27 @@ #! /bin/sh rm $2 - To use these scripts, put them both where they can be executed and set + 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 + 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 [1mless[22m, rather than putting the data into a replacement + It is also possible to set up an input preprocessor to pipe the file + data directly to [1mless[22m, rather than putting the data into a replacement file. This avoids the need to decompress the entire file before start‐ ing to view it. An input preprocessor that works this way is called an - input pipe. An input pipe, instead of writing the name of a replace‐ + input pipe. An input pipe, instead of writing the name of a replace‐ ment file on its standard output, writes the entire contents of the re‐ - placement file on its standard output. If the input pipe does not - write any characters on its standard output, then there is no replace‐ - ment file and [1mless [22muses 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 + placement file on its standard output. If the input pipe does not + write any characters on its standard output, then there is no replace‐ + ment file and [1mless [22muses 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 pre‐ + For example, on many Unix systems, this script will work like the pre‐ vious example scripts: lesspipe.sh: @@ -1678,29 +1731,29 @@ LESSOPEN="|lesspipe.sh %s". Note that a preprocessor cannot output an empty file, since that is in‐ - terpreted as meaning there is no replacement, and the original file is - used. To avoid this, if LESSOPEN starts with two vertical bars, the - 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 + terpreted 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 compat‐ - ibility with previous versions of [1mless[22m, if LESSOPEN starts with only + ibility with previous versions of [1mless[22m, 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 + 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 + up. In this case, the replacement file name passed to the LESSCLOSE postprocessor is "-". - For compatibility with previous versions of [1mless[22m, the input preproces‐ + For compatibility with previous versions of [1mless[22m, the input preproces‐ sor or pipe is not used if [1mless [22mis 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 + 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 charac‐ - ters 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 + name consisting of a single dash. Similarly, if the first two charac‐ + ters 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. @@ -1711,25 +1764,25 @@ can be displayed directly to the screen. control characters - should not be displayed directly, but are expected to be found + 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 + should not be displayed directly and are not expected to be found in text files. A "character set" is simply a description of which characters are to be - considered normal, control, and binary. The LESSCHARSET environment - variable may be used to select a character set. Possible values for + considered normal, control, and binary. The LESSCHARSET environment + variable may be used to select a character set. Possible values for LESSCHARSET are: - ascii BS, TAB, NL, CR, and formfeed are control characters, all chars - with values between 32 and 126 are normal, and all others are + 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 + 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. @@ -1741,8 +1794,8 @@ 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 + 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. @@ -1750,10 +1803,10 @@ 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 mul‐ - ti‐byte characters. + 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 @@ -1766,13 +1819,13 @@ one character in the character set. The character "." is used for a normal character, "c" for control, and "b" for binary. A decimal num‐ ber 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 bina‐ - ry, 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.) + character 0 is binary, 1, 2 and 3 are control, 4, 5, 6 and 7 are bi‐ + nary, 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 char‐ + acter set.) - This table shows the value of LESSCHARDEF which is equivalent to each + This table shows the value of LESSCHARDEF which is equivalent to each of the possible values for LESSCHARSET: ascii 8bcccbcc18b95.b dos 8bcccbcc12bc5b95.b. @@ -1785,61 +1838,61 @@ 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 + 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 [1msetlocale [22min‐ - terface, [1mless [22mwill use setlocale to determine the character set. set‐ - locale is controlled by setting the LANG or LC_CTYPE environment vari‐ + terface, [1mless [22mwill use setlocale to determine the character set. set‐ + locale is controlled by setting the LANG or LC_CTYPE environment vari‐ ables. - Finally, if the [4msetlocale[24m interface is also not available, the default + Finally, if the [4msetlocale[24m interface is also not available, the default character set is utf‐8. - Control and binary characters are displayed in standout (reverse + 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 + (e.g. ^A for control‐A). Caret notation is used only if inverting the 0100 bit results in a normal printable character. Otherwise, the char‐ - acter is displayed as a hex number in angle brackets. This format can - be changed by setting the LESSBINFMT environment variable. LESSBINFMT + acter 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 re‐ - sult of expanding the character via LESSBINFMT must be less than 31 + "*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 re‐ + sult of expanding the character via LESSBINFMT must be less than 31 characters. When the character set is utf‐8, the LESSUTFBINFMT environment variable acts similarly to LESSBINFMT but it applies to Unicode code points that - were successfully decoded but are unsuitable for display (e.g., unas‐ - signed code points). Its default value is "<U+%04lX>". Note that - LESSUTFBINFMT and LESSBINFMT share their display attribute setting - ("*x") so specifying one will affect both; LESSUTFBINFMT is read after - LESSBINFMT so its setting, if any, will have priority. Problematic - octets in a UTF‐8 file (octets of a truncated sequence, octets of a - complete but non‐shortest form sequence, invalid octets, and stray - trailing octets) are displayed individually using LESSBINFMT so as to + were successfully decoded but are unsuitable for display (e.g., unas‐ + signed code points). Its default value is "<U+%04lX>". Note that + LESSUTFBINFMT and LESSBINFMT share their display attribute setting + ("*x") so specifying one will affect both; LESSUTFBINFMT is read after + LESSBINFMT so its setting, if any, will have priority. Problematic + octets in a UTF‐8 file (octets of a truncated sequence, octets of a + 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 + When the character set is utf‐8, in rare cases it may be desirable to override the Unicode definition of the type of certain characters. For - example, characters in a Private Use Area are normally treated as con‐ - trol characters, but if you are using a custom font with printable - characters in that range, it may be desirable to tell [1mless [22mto treat - such characters as printable. This can be done by setting the LESSUT‐ - FCHARDEF environment variable to a comma‐separated list of [4mcharacter[0m - [4mtype[24m 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 + example, characters in a Private Use Area are normally treated as con‐ + trol characters, but if you are using a custom font with printable + characters in that range, it may be desirable to tell [1mless [22mto treat + such characters as printable. This can be done by setting the LESSUT‐ + FCHARDEF environment variable to a comma‐separated list of [4mcharacter[0m + [4mtype[24m 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. @@ -1857,25 +1910,25 @@ would make all Private Use Area characters be treated as printable. [1mPROMPTS[0m - The -P option allows you to tailor the prompt to your preference. The - string given to the -P option replaces the specified prompt string. + 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 ordi‐ - nary user need not understand the details of constructing personalized + mechanism is rather complicated to provide flexibility, but the ordi‐ + nary 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 + 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[4mX[24m Replaced by the byte offset into the current input file. The b + %b[4mX[24m Replaced by the byte offset into the current input file. The b is followed by a single character (shown as [4mX[24m above) which spec‐ - ifies the line whose byte offset is to be used. If the charac‐ - ter is a "t", the byte offset of the top line in the display is + ifies the line whose byte offset is to be used. If the charac‐ + ter 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 bot‐ - tom 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 + tom 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. @@ -1883,54 +1936,54 @@ %c Replaced by the column number of the text appearing in the first column of the screen. - %d[4mX[24m Replaced by the page number of a line in the input file. The + %d[4mX[24m Replaced by the page number of a line in the input file. The line to be used is determined by the [4mX[24m, as with the %b option. - %D Replaced by the number of pages in the input file, or equiva‐ + %D Replaced by the number of pages in the input file, or equiva‐ lently, the page number of the last line in the input file. - %E Replaced by the name of the editor (from the VISUAL environment - variable, or the EDITOR environment variable if VISUAL is not + %E Replaced by the name of the editor (from the VISUAL environment + variable, or the EDITOR environment variable if VISUAL is not defined). See the discussion of the LESSEDIT feature below. %f Replaced by the name of the current input file. - %F Replaced by the last component of the name of the current input + %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 + %g Replaced by the shell‐escaped name of the current input file. + This is useful when the expanded string will be used in a shell command, such as in LESSEDIT. - %i Replaced by the index of the current file in the list of input + %i Replaced by the index of the current file in the list of input files. - %l[4mX[24m Replaced by the line number of a line in the input file. The + %l[4mX[24m Replaced by the line number of a line in the input file. The line to be used is determined by the [4mX[24m, as with the %b option. %L Replaced by the line number of the last line in the input file. %m Replaced by the total number of input files. - %o Replaced by the URI of the currently selected OSC 8 hyperlink, + %o Replaced by the URI of the currently selected OSC 8 hyperlink, or a question mark if no hyperlink is selected. This is used by OSC 8 handlers as explained in the ^O^O command description. - %p[4mX[24m Replaced by the percent into the current input file, based on - byte offsets. The line used is determined by the [4mX[24m as with the + %p[4mX[24m Replaced by the percent into the current input file, based on + byte offsets. The line used is determined by the [4mX[24m as with the %b option. - %P[4mX[24m Replaced by the percent into the current input file, based on - line numbers. The line used is determined by the [4mX[24m as with the + %P[4mX[24m Replaced by the percent into the current input file, based on + line numbers. The line used is determined by the [4mX[24m as with the %b option. %s Same as %B. - %t Causes any trailing spaces to be removed. Usually used at the + %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 + %T Normally expands to the word "file". However if viewing files + via a tags list using the -t option, it expands to the word "tag". %x Replaced by the name of the next input file in the list. @@ -1938,15 +1991,15 @@ 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 evaluat‐ - ed. 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 + 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 evalu‐ + ated. 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. + 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. @@ -1961,7 +2014,7 @@ ?e True if at end‐of‐file. - ?f True if there is an input filename (that is, if input is not a + ?f True if there is an input filename (that is, if input is not a pipe). ?l[4mX[24m True if the line number of the specified line is known. @@ -1972,45 +2025,45 @@ ?n True if this is the first prompt in a new input file. - ?p[4mX[24m True if the percent into the current input file, based on byte + ?p[4mX[24m True if the percent into the current input file, based on byte offsets, of the specified line is known. - ?P[4mX[24m True if the percent into the current input file, based on line + ?P[4mX[24m True if the percent into the current input file, based on line numbers, of the specified line is known. ?s Same as "?B". - ?x True if there is a next input file (that is, if the current in‐ + ?x True if there is a next input file (that is, if the current in‐ put file is not the last one). - Any characters other than the special ones (question mark, colon, peri‐ - od, percent, and backslash) become literally part of the prompt. Any - of the special characters may be included in the prompt literally by + Any characters other than the special ones (question mark, colon, pe‐ + riod, 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 "Stan‐ + This prompt prints the filename, if known; otherwise the string "Stan‐ dard input". ?f%f .?ltLine %lt:?pt%pt\%:?btByte %bt:‐... - This prompt would print the filename, if known. The filename is fol‐ - lowed by the line number, if known, otherwise the percent if known, + This prompt would print the filename, if known. The filename is fol‐ + lowed by the line number, if known, otherwise the percent if known, otherwise the byte offset if known. Otherwise, a dash is printed. No‐ - tice how each question mark has a matching period, and how the % after + tice 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, fol‐ - lowed 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 + This prints the filename if this is the first prompt in a file, fol‐ + lowed 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 refer‐ - ence, here are the defaults for the other two prompts (-m and -M re‐ + ence, here are the defaults for the other two prompts (-m and -M re‐ spectively). Each is broken into two lines here for readability only. ?n?f%f .?m(%T %i of %m) ..?e(END) ?x‐ Next\: %x.: @@ -2024,22 +2077,22 @@ ?f%f .?m(%T %i of %m) .?ltlines %lt‐%lb?L/%L. . byte %bB?s/%s. ?e(END) :?pB%pB\%..%t - The prompt expansion features are also used for another purpose: if an - environment variable LESSEDIT is defined, it is used as the command to - be executed when the v command is invoked. The LESSEDIT string is ex‐ - panded in the same way as the prompt strings. The default value for + The prompt expansion features are also used for another purpose: if an + environment variable LESSEDIT is defined, it is used as the command to + be executed when the v command is invoked. The LESSEDIT string is ex‐ + panded in the same way as the prompt strings. The default value for LESSEDIT is: %E ?lm+%lm. %g Note that this expands to the editor name, followed by a + and the line - number, followed by the shell‐escaped file name. If your editor does - not accept the "+linenumber" syntax, or has other differences in invo‐ - cation syntax, the LESSEDIT variable can be changed to modify this de‐ + number, followed by the shell‐escaped file name. If your editor does + not accept the "+linenumber" syntax, or has other differences in invo‐ + cation syntax, the LESSEDIT variable can be changed to modify this de‐ fault. [1mSECURITY[0m - When the environment variable LESSSECURE is set to 1, [1mless [22mruns in a + When the environment variable LESSSECURE is set to 1, [1mless [22mruns in a "secure" mode. In this mode, these features are disabled: edit the edit command (v) @@ -2063,69 +2116,70 @@ shell the shell and pshell commands (! and #) - stop stopping [1mless [22mvia a SIGSTOP signal + stop stopping [1mless [22mvia a SIGTSTP signal tags use of tags files (‐t) - The LESSSECURE_ALLOW environment variable can be set to a comma‐sepa‐ - rated list of names of features which are selectively enabled when + The LESSSECURE_ALLOW environment variable can be set to a comma‐sepa‐ + rated 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 ab‐ - breviation is unambiguous. For example, if LESSSECURE=1 and + the above list. A feature name may be abbreviated as long as the ab‐ + breviation is unambiguous. For example, if LESSSECURE=1 and LESSSECURE_ALLOW=hist,edit were set, all of the above features would be disabled except for history files and the edit command. - Less can also be compiled to be permanently in "secure" mode. In that + Less can also be compiled to be permanently in "secure" mode. In that case, the LESSSECURE and LESSSECURE_ALLOW variables are ignored. [1mCOMPATIBILITY WITH MORE[0m If the environment variable LESS_IS_MORE is set to 1, or if the program - is invoked via a file link named "more", [1mless [22mbehaves (mostly) in con‐ - formance with the POSIX [1mmore[22m(1) command specification. In this mode, - less behaves differently in these ways: + is invoked via a file link named "more" and the environment variable + LESS_IS_MORE is not set to 0, [1mless [22mbehaves (mostly) in conformance with + the POSIX [1mmore[22m(1) command specification. In this mode, less behaves + differently in these ways: The -e option works differently. If the -e option is not set, [1mless [22mbe‐ - haves as if the -e option were set. If the -e option is set, [1mless [22mbe‐ + haves as if the -e option were set. If the -e option is set, [1mless [22mbe‐ haves 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--". + 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 + 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 [1mless [22mcommand rather + The parameter to the -p option is taken to be a [1mless [22mcommand rather than a search pattern. - The LESS environment variable is ignored, and the MORE environment + The LESS environment variable is ignored, and the MORE environment variable is used in its place. [1mENVIRONMENT VARIABLES[0m Environment variables may be specified either in the system environment - as usual, or in a [1mlesskey[22m(1) file. If environment variables are de‐ + as usual, or in a [1mlesskey[22m(1) file. If environment variables are de‐ fined 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 + 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 + 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 + 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 vari‐ + Concatenation of the HOMEDRIVE and HOMEPATH environment vari‐ ables is the name of the user’s home directory if the HOME vari‐ able is not set (only in the Windows version). - INIT Name of the user’s init directory (used to find a lesskey file + 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. @@ -2136,13 +2190,28 @@ LESS Options which are passed to [1mless [22mautomatically. LESSANSIENDCHARS - Characters which may end an ANSI color escape sequence (default + 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:;[?!"'#%()*+ ". + Characters which may appear between the ESC character and the + end character in an ANSI color escape sequence (default + "0123456789:;[?!"'#%()*+ "). + + LESSANSIOSCALLOW + A comma‐separated list of OSC types which are output directly to + the terminal when -R is in effect. By default, only OSC 8 se‐ + quences 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, se‐ + quences 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. @@ -2158,21 +2227,21 @@ LESSECHO Name of the lessecho program (default "lessecho"). The lessecho - program is needed to expand metacharacters, such as * and ?, in + program is needed to expand metacharacters, such as * and ?, in filenames on Unix systems. LESSEDIT - Editor prototype string (used for the v command). See discus‐ + Editor prototype string (used for the v command). See discus‐ sion 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 [1mglob‐[0m + Name of the command used by the -t option to find global tags. + Normally should be set to "global" if your system has the [1mglob‐[0m [1mal[22m(1) command. If not set, global tags are not used. LESSHISTFILE - Name of the history file used to remember search commands and - shell commands between invocations of [1mless[22m. If set to "-" or + Name of the history file used to remember search commands and + shell commands between invocations of [1mless[22m. If set to "-" or "/dev/null", a history file is not used. The default depends on the operating system, but is usually: @@ -2193,28 +2262,28 @@ Name of the default [4mlesskey[24m [4msource[24m file. LESSKEY - Name of the default [4mlesskey[24m [4mbinary[24m file. (Not used if + Name of the default [4mlesskey[24m [4mbinary[24m file. (Not used if "$LESSKEYIN" exists.) LESSKEY_CONTENT - The value is parsed as if it were the parameter of a --lesskey‐ + The value is parsed as if it were the parameter of a --lesskey‐ content option. LESSKEYIN_SYSTEM Name of the default system‐wide [4mlesskey[24m [4msource[24m file. LESSKEY_SYSTEM - Name of the default system‐wide [4mlesskey[24m [4mbinary[24m file. (Not used + Name of the default system‐wide [4mlesskey[24m [4mbinary[24m file. (Not used if "$LESSKEYIN_SYSTEM" exists.) LESSMETACHARS - List of characters which are considered "metacharacters" by the + List of characters which are considered "metacharacters" by the shell. LESSMETAESCAPE - Prefix which less will add before each metacharacter in a com‐ - mand sent to the shell. If LESSMETAESCAPE is an empty string, - commands containing metacharacters will not be passed to the + Prefix which less will add before each metacharacter in a com‐ + mand sent to the shell. If LESSMETAESCAPE is an empty string, + commands containing metacharacters will not be passed to the shell. LESSOPEN @@ -2224,11 +2293,11 @@ Runs less in "secure" mode. See discussion under SECURITY. LESSSECURE_ALLOW - Enables individual features which are normally disabled by + Enables individual features which are normally disabled by LESSSECURE. See discussion under SECURITY. LESSSEPARATOR - String to be appended to a directory name in filename comple‐ + String to be appended to a directory name in filename comple‐ tion. LESSUTFBINFMT @@ -2239,30 +2308,30 @@ 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 [1mless [22muse less than the full screen width. If - set to a negative number, sets the number of columns used to + precedence over the system’s idea of the screen size, so it can + be used to make [1mless [22muse 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 [1mless [22muse 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, [1mless [22mre‐ + 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 [1mless [22muse 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, [1mless [22mre‐ paints the entire screen on every movement command, so scrolling may be slower. LESS_DATA_DELAY - Duration (in milliseconds) after starting to read data from the - input, after which the "Waiting for data" message will be dis‐ + Duration (in milliseconds) after starting to read data from the + input, after which the "Waiting for data" message will be dis‐ played. The default is 4000 (4 seconds). LESS_IS_MORE Emulate the [1mmore[22m(1) command. LESS_OSC8_xxx - Where "xxx" is a URI scheme such as "http" or "file", sets an + 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. @@ -2270,6 +2339,20 @@ Sets an OSC 8 handler for opening OSC 8 links for which there is no specific LESS_OSC8_xxx handler set for the "xxx" scheme. + LESS_SHELL_LINES + When the -F option is set, [1mless [22mexits automatically if the num‐ + ber 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 [1mless [22mcommand characters, those + commands will be executed when [1mless [22mreceives a SIGUSR1 signal. + LESS_TERMCAP_xx Where "xx" is any two characters, overrides the definition of the termcap "xx" capability for the terminal. @@ -2318,7 +2401,7 @@ [1mlesskey[22m(1), [1mlessecho[22m(1) [1mCOPYRIGHT[0m - Copyright (C) 1984‐2024 Mark Nudelman + Copyright (C) 1984‐2025 Mark Nudelman less is part of the GNU project and is free software. You can redis‐ tribute it and/or modify it under the terms of either (1) the GNU Gen‐ @@ -2337,8 +2420,8 @@ [1mAUTHOR[0m Mark Nudelman - Report bugs at https://github.com/gwsw/less/issues. + Report bugs at ⟨https://github.com/gwsw/less/issues⟩. For more information, see the less homepage at - https://greenwoodsoftware.com/less. + ⟨https://greenwoodsoftware.com/less⟩. - Version 668: 06 Oct 2024 [4mLESS[24m(1) + Version 678: 01 May 2025 [4mLESS[24m(1) |