less linux command

less

less [options] [filename]

less is a program for paging through files or other output. It was written in reaction to the perceived primitiveness of more (hence its name). Some commands may be preceded by a number.

Options

-[z]num

Set number of lines to scroll to num. Default is one screenful. A negative num sets the number to num lines less than the current number.

+[+]command

Run command on startup. If command is a number, jump to that line. The option ++ applies this command to each file in the command-line list.

Print help screen. Ignore all other options; do not page through file.

-a

When searching, begin after last line displayed. (Default is to search from second line displayed.)

-bbuffers

Use buffers buffers for each file (default is 10). Buffers are 1 kilobyte in size.

-c

Redraw screen from top, not bottom.

-d

Suppress dumb-terminal error messages.

-e

Automatically exit after reaching EOF twice.

-f

Force opening of directories and devices; do not print warning when opening binaries.

-g

Highlight only string found by past search command, not all matching strings.

-hnum

Never scroll backward more than num lines at once.

-i

Make searches case-insensitive, unless the search string contains uppercase letters.

-jnum

Position target line on line num of screen. Target line can be the result of a search or a jump. Count lines beginning from 1 (top line). A negative num is counted back from bottom of screen.

-kfile

Read file to define special key bindings.

-m

Display more-like prompt, including percent of file read.

-n

Do not calculate line numbers. Affects -m and -M options and = and v commands (disables passing of line number to editor).

-ofile

When input is from a pipe, copy output to file as well as to screen. (Prompt for overwrite authority if file exists.)

-ppattern

At startup, search for first occurrence of pattern.

m

Set medium prompt (specified by -m).

M

Set long prompt (specified by -M).

Set message printed by = command.

-q

Disable ringing of bell on attempts to scroll past EOF or before beginning of file. Attempt to use visual bell instead.

-r

Display 'raw' control characters, instead of using ^x notation. Sometimes leads to display problems.

-s

Print successive blank lines as one line.

-ttag

Edit file containing tag. Consult ./tags (constructed by ctags).

-u

Treat backspaces and carriage returns as printable input.

-w

Print lines after EOF as blanks instead of tildes (~).

-xn

Set tab stops to every n characters. Default is 8.

-yn

Never scroll forward more than n lines at once.

-B

Do not automatically allocate buffers for data read from a pipe. If -b specifies a number of buffers, allocate that many. If necessary, allow information from previous screens to be lost.

-C

Redraw screen by clearing it and then redrawing from top.

-E

Automatically exit after reaching EOF once.

-G

Never highlight matching search strings.

-I

Make searches case-insensitive, even when the search string contains uppercase letters.

-M

Prompt more verbosely than with -m, including percentage, line number, and total lines.

-N

Print line number before each line.

-Ofile

Similar to -o but does not prompt when overwriting file.

-P[m,M,=]prompt

Set prompt (as defined by -m, -M, or =). Default is short prompt (-m).

-Q

Never ring terminal bell.

-S

Cut, do not fold, long lines.

-Tfile

With the -t option or :t command, read file instead of ./tags.

-U

Treat backspaces and carriage returns as control characters.

-X

Do not send initialization and deinitialization strings from termcap to terminal.

Commands

Many commands can be preceded by a numeric argument, referred to as number in the command descriptions.

SPACE, ^V, f, ^F

Scroll forward the default number of lines (usually one windowful).

z

Similar to SPACE but allows the number of lines to be specified, in which case it resets the default to that number.

RETURN, ^N, e, ^E, j, ^J

Scroll forward. Default is one line. Display all lines, even if the default is more lines than the screen size.

d, ^D

Scroll forward. Default is one-half the screen size. The number of lines may be specified, in which case the default is reset.

b, ^B, ESC-v

Scroll backward. Default is one windowful.

w

Like b but allows the number of lines to be specified, in which case it resets the default to that number.

y, ^Y, ^P, k, ^K

Scroll backward. Default is one line. Display all lines, even if the default is more lines than the screen size.

u, ^U

Scroll backward. Default is one-half the screen size. The number of lines may be specified, in which case the default is reset.

r, ^R, ^L

Redraw screen.

R

Like r but discard buffered input.

F

Scroll forward. When an EOF is reached, continue trying to find more output, behaving similarly to tail -f.

g, <, ESC-<

Skip to a line. Default is 1.

G, >, ESC->

Skip to a line. Default is the last one.

p, %

Skip to a position number percent of the way into the file.

. If the top line contains multiple

If the bottom line on the screen includes a }, find its matching s, use number to determine which one to use in finding a match.

If the top line on the screen includes a (, find its matching ). If the top line contains multiple (s, use number to determine which one to use in finding a match.

If the bottom line on the screen includes a ), find its matching (. If the bottom line contains multiple )s, use number to determine which one to use in finding a match.

If the top line on the screen includes a [, find its matching ]. If the top line contains multiple [s, use number to determine which one to use in finding a match.

If the bottom line on the screen includes a ], find its matching [. If the bottom line contains multiple ]s, use number to determine which one to use in finding a match.

ESC-^F

Behave like in its search.

ESC-^B

Behave like } but prompt for two characters, which it substitutes for in its search.

m

Prompt for a lowercase letter and then use that letter to mark the current position.

Prompt for a lowercase letter and then go to the position marked by that letter. There are some special characters:

Return to position before last 'large movement.'

Beginning of file.

End of file.

^X^X

Same as '.

/pattern

Find next occurrence of pattern, starting at second line displayed. Some special characters can be entered before pattern:

Find lines that do not contain pattern.

If current file does not contain pattern, continue through the rest of the files in the command line list.

Search from the first line in the first file specified on the command line, no matter what the screen currently displays.

?pattern

Search backward, beginning at the line before the top line. Treats !, *, and @ as special characters when they begin pattern, as / does.

ESC-/pattern

Same as /*.

ESC-?pattern

Same as ?*.

n

Repeat last pattern search.

N

Repeat last pattern search, in the reverse direction.

ESC-n

Repeat previous search command but as though it were prefaced by *.

ESC-N

Repeat previous search command but as though it were prefaced by * and in the opposite direction.

ESC-u

Toggle search highlighting.

:e [filename]

Read in filename and insert it into the command-line list of filenames. Without filename, reread the current file. filename may contain special characters:

Name of current file

Name of previous file

^X^V, E

Same as :e.

:n

Read in next file in command-line list.

:p

Read in previous file in command-line list.

:x

Read in first file in command-line list.

:f, =, ^G

Print filename, position in command-line list, line number on top of window, total lines, byte number, and total bytes.

Expects to be followed by a command-line option letter. Toggles the value of that option or, if appropriate, prompts for its new value.

Expects to be followed by a command-line option letter. Resets that option to its default.

Expects to be followed by a command-line option letter. Resets that option to the opposite of its default, where the opposite can be determined.

Expects to be followed by a command-line option letter. Display that option's current setting.

+command

Execute command each time a new file is read in.

q, :q, :Q, ZZ

Exit.

v

Not valid for all versions. Invoke editor specified by $VISUAL or $EDITOR, or vi if neither is set.

! [command]

Not valid for all versions. Invoke $SHELL or sh. If command is given, run it and then exit. Special characters:

Name of current file

Name of previous file

Last shell command

| mark-letter command

Not valid for all versions. Pipe fragment of file (from first line on screen to mark-letter) to command. mark-letter may also be:

Beginning of file.

End of file.

., newline

Current screen is piped.

Prompts

The prompt interprets certain sequences specially. Those beginning with % are always evaluated. Those beginning with ? are evaluated if certain conditions are true. Some prompts determine the position of particular lines on the screen. These sequences require that a method of determining that line be specified. See the -P option and the manpage for more information.