Commands marked with * may be preceded by a number, N. Notes in parentheses indicate the behavior if N is given. A key preceded by a caret indicates the Ctrl key; thus ^K is ctrl-K.
h H Display this help. q :q Q :Q ZZ Exit. ---------------------------------------------------------------------------
MOVING
e ^E j ^N CR * Forward one line (or N lines). y ^Y k ^K ^P * Backward one line (or N lines). f ^F ^V SPACE * Forward one window (or N lines). b ^B ESC-v * Backward one window (or N lines). z * Forward one window (and set window to N). w * Backward one window (and set window to N). ESC-SPACE * Forward one window, but don't stop at end-of-file. d ^D * Forward one half-window (and set half-window to N). u ^U * Backward one half-window (and set half-window to N). ESC-) RightArrow * Left one half screen width (or N positions). ESC-( LeftArrow * Right one half screen width (or N positions). F Forward forever; like "tail -f". r ^R ^L Repaint screen. R Repaint screen, discarding buffered input. --------------------------------------------------- Default "window" is the screen height. Default "half-window" is half of the screen height. ---------------------------------------------------------------------------
SEARCHING
/pattern * Search forward for (N-th) matching line. ?pattern * Search backward for (N-th) matching line. n * Repeat previous search (for N-th occurrence). N * Repeat previous search in reverse direction. ESC-n * Repeat previous search, spanning files. ESC-N * Repeat previous search, reverse dir. & spanning files. ESC-u Undo (toggle) search highlighting. &pattern * Display only matching lines --------------------------------------------------- A search pattern may be preceded by one or more of: ^N or ! Search for NON-matching lines. ^E or * Search multiple files (pass thru END OF FILE). ^F or @ Start search at FIRST file (for /) or last file (for ?). ^K Highlight matches, but don't move (KEEP position). ^R Don't use REGULAR EXPRESSIONS. ---------------------------------------------------------------------------
JUMPING
g < ESC-< * Go to first line in file (or line N). G > ESC-> * Go to last line in file (or line N). p % * Go to beginning of file (or N percent into file). t * Go to the (N-th) next tag. T * Go to the (N-th) previous tag. { ( [ * Find close bracket } ) ]. } ) ] * Find open bracket { ( [. ESC-^F <c1> <c2> * Find close bracket <c2>. ESC-^B <c1> <c2> * Find open bracket <c1> --------------------------------------------------- Each "find close bracket" command goes forward to the close bracket matching the (N-th) open bracket in the top line. Each "find open bracket" command goes backward to the open bracket matching the (N-th) close bracket in the bottom line.
m<letter> Mark the current position with <letter>. '<letter> Go to a previously marked position. '' Go to the previous position. ^X^X Same as '. --------------------------------------------------- A mark is any upper-case or lower-case letter. Certain marks are predefined: ^ means beginning of the file $ means end of the file ---------------------------------------------------------------------------
CHANGING FILES
:e [file] Examine a new file. ^X^V Same as :e. :n * Examine the (N-th) next file from the command line. :p * Examine the (N-th) previous file from the command line. :x * Examine the first (or N-th) file from the command line. :d Delete the current file from the command line list. = ^G :f Print current file name. ---------------------------------------------------------------------------
MISCELLANEOUS COMMANDS
-<flag> Toggle a command line option [see OPTIONS below]. --<name> Toggle a command line option, by name. _<flag> Display the setting of a command line option. __<name> Display the setting of an option, by name. +cmd Execute the less cmd each time a new file is examined.
!command Execute the shell command with $SHELL. |Xcommand Pipe file between current pos & mark X to shell command. v Edit the current file with $VISUAL or $EDITOR. V Print version number of "less". ---------------------------------------------------------------------------
OPTIONS
Most options may be changed either on the command line, or from within less by using the - or -- command. Options may be given in one of two forms: either a single character preceded by a -, or a name preceded by --.
-? ........ --help Display help (from command line). -a ........ --search-skip-screen Search skips current screen. -A ........ --SEARCH-SKIP-SCREEN Search starts just after target line. -b [N] .... --buffers=[N] Number of buffers. -B ........ --auto-buffers Don't automatically allocate buffers for pipes. -c -C .... --clear-screen --CLEAR-SCREEN Repaint by clearing rather than scrolling. -d ........ --dumb Dumb terminal. -D [xn.n] . --color=xn.n Set screen colors. (MS-DOS only) -e -E .... --quit-at-eof --QUIT-AT-EOF Quit at end of file. -f ........ --force Force open non-regular files. -F ........ --quit-if-one-screen Quit if entire file fits on first screen. -g ........ --hilite-search Highlight only last match for searches. -G ........ --HILITE-SEARCH Don't highlight any matches for searches. --old-bot Revert to the old bottom of screen behavior. -h [N] .... --max-back-scroll=[N] Backward scroll limit. -i ........ --ignore-case Ignore case in searches that do not contain uppercase. -I ........ --IGNORE-CASE Ignore case in all searches. -j [N] .... --jump-target=[N] Screen position of target lines. -J ........ --status-column Display a status column at left edge of screen. -k [file] . --lesskey-file=[file] Use a lesskey file. -K --quit-on-intr Exit less in response to ctrl-C. -L ........ --no-lessopen Ignore the LESSOPEN environment variable. -m -M .... --long-prompt --LONG-PROMPT Set prompt style. -n ........ --line-numbers Don't use line numbers. -N ........ --LINE-NUMBERS Use line numbers. -o [file] . --log-file=[file] Copy to log file (standard input only). -O [file] . --LOG-FILE=[file] Copy to log file (unconditionally overwrite). -p [pattern] --pattern=[pattern] Start at pattern (from command line). -P [prompt] --prompt=[prompt] Define new prompt. -q -Q .... --quiet --QUIET --silent --SILENT Quiet the terminal bell. -r -R .... --raw-control-chars --RAW-CONTROL-CHARS Output "raw" control characters. -s ........ --squeeze-blank-lines Squeeze multiple blank lines. -S ........ --chop-long-lines Chop (truncate) long lines rather than wrapping. -t [tag] .. --tag=[tag] Find a tag. -T [tagsfile] --tag-file=[tagsfile] Use an alternate tags file. -u -U .... --underline-special --UNDERLINE-SPECIAL Change handling of backspaces. -V ........ --version Display the version number of "less". -w ........ --hilite-unread Highlight first new line after forward-screen. -W ........ --HILITE-UNREAD Highlight first new line after any forward movement. -x [N[,...]] --tabs=[N[,...]] Set tab stops. -X ........ --no-init Don't use termcap init/deinit strings. -y [N] .... --max-forw-scroll=[N] Forward scroll limit. -z [N] .... --window=[N] Set size of window. -" [c[c]] . --quotes=[c[c]] Set shell quote characters. -~ ........ --tilde Don't display tildes after end of file. -# [N] .... --shift=[N] Horizontal scroll amount (0 = one half screen width) ........ --no-keypad Don't send termcap keypad init/deinit strings. ........ --follow-name The F command changes files if the input file is renamed. ........ --use-backslash Subsequent options use backslash as escape char.
These keys can be used to edit text being entered on the "command line" at the bottom of the screen.
RightArrow ESC-l Move cursor right one character. LeftArrow ESC-h Move cursor left one character. ctrl-RightArrow ESC-RightArrow ESC-w Move cursor right one word. ctrl-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word. HOME ESC-0 Move cursor to start of line. END ESC-$ Move cursor to end of line. BACKSPACE Delete char to left of cursor. DELETE ESC-x Delete char under cursor. ctrl-BACKSPACE ESC-BACKSPACE Delete word to left of cursor. ctrl-DELETE ESC-DELETE ESC-X Delete word under cursor. ctrl-U ESC (MS-DOS only) Delete entire line. UpArrow ESC-k Retrieve previous command line. DownArrow ESC-j Retrieve next command line. TAB Complete filename & cycle. SHIFT-TAB ESC-TAB Complete filename & reverse cycle. ctrl-L Complete filename, list all.
less交互指令
在使用 less 命令查看文件内容的过程中，和 more 命令一样，也会进入交互界面，因此需要读者掌握一些常用的交互指令。
交互指令
功能
/字符串
向下搜索“字符串”的功能。
?字符串
向上搜索“字符串”的功能。
n
重复*前一个搜索（与 / 成 ? 有关）。
N
反向重复前一个搜索（与 / 或 ? 有关）。
b
向上移动一页。
d
向下移动半页。
h 或 H
显示帮助界面。
q 或 Q
退出 less 命令。
y
向上移动一行。
空格键
向下移动一页。
回车键
向下移动一行。
【PgDn】键
向下移动一页。
【PgUp】键
向上移动一页。
Ctrl+f
向下移动一页。
Ctrl+b
向上移动一页。
Ctrl+d
向下移动一页。
Ctrl+u
向上移动半页。
j
向下移动一行。
k
向上移动一行。
G
移动至最后一行。
g
移动到第一行。
ZZ
退出 less 命令。
v
使用配置的编辑器编辑当前文件。
[
移动到本文档的上一个节点。
]
移动到本文档的下一个节点。
p
移动到同级的上一个节点。
u
向上移动半页。
less选项
选项
选项含义
-N
显示每行的行号。
-S
行过长时将超出部分舍弃。
-e
当文件显示结束后，自动离开。
-g
只标志最后搜索到的关键同。
-Q
不使用警告音。
-i
忽略搜索时的大小写。
-m
显示类似 more 命令的百分比。
-f
强迫打开特殊文件，比如外围设备代号、目录和二进制文件。
-s
显示连续空行为一行。
-b <缓冲区大小>
设置缓冲区的大小。
-o <文件名>
将 less 输出的内容保存到指定文件中。
-x <数字>
将【Tab】键显示为规定的数字空格。
less -N filename：显示行号
如果要 less 显示行号，请使用以下 -N 选项启动程序：
1
less -N filename
less -X filename
默认情况下， less 退出时，将从屏幕中清除文件内容。要在屏幕上保留文件内容，请使用以下 -X 选项：
1
less -X filename
[root@localhost Linux_Test]# less -X date_test.txt
2020-01-24 04:05:06
2021/4/25
[root@localhost Linux_Test]#
less +F 日志文件
该 +F 选项告诉 less 您查看文件内容可能会更改。这在打开日志文件时很有用。 less +F /var/log/messages 添加了 +F 选项的 less的表现与 tail -f 命令几乎相同。