постраничная основа (by-page basis)
Расширенное описание (Extended description)
The following section describes the behavior of more when the
standard output is a terminal device. If the standard output is
not a terminal device, no options other than -s shall have any
effect, and all input files shall be copied to standard output
otherwise unmodified, at which time more shall exit without
further action.
The number of lines available per screen shall be determined by
the -n option, if present, or by examining values in the
environment (see the ENVIRONMENT VARIABLES section). If neither
method yields a number, an unspecified number of lines shall be
used.
The maximum number of lines written shall be one less than this
number, because the screen line after the last line written shall
be used to write a user prompt and user input. If the number of
lines in the screen is less than two, the results are undefined.
It is unspecified whether user input is permitted to be longer
than the remainder of the single line where the prompt has been
written.
The number of columns available per line shall be determined by
examining values in the environment (see the ENVIRONMENT
VARIABLES section), with a default value as described in the Base
Definitions volume of POSIX.1‐2017, Chapter 8, Environment
Variables.
Lines that are longer than the display shall be folded; the
length at which folding occurs is unspecified, but should be
appropriate for the output device. Folding may occur between
glyphs of single characters that take up multiple display
columns.
When standard output is a terminal and -u is not specified, more
shall treat <backspace> and <carriage-return> characters
specially:
* A character, followed first by a sequence of n <backspace>
characters (where n is the same as the number of column
positions that the character occupies), then by n
<underscore> characters ('_'), shall cause that character to
be written as underlined text, if the terminal type supports
that. The n <underscore> characters, followed first by n
<backspace> characters, then any character with n column
positions, shall also cause that character to be written as
underlined text, if the terminal type supports that.
* A sequence of n <backspace> characters (where n is the same
as the number of column positions that the previous character
occupies) that appears between two identical printable
characters shall cause the first of those two characters to
be written as emboldened text (that is, visually brighter,
standout mode, or inverse-video mode), if the terminal type
supports that, and the second to be discarded. Immediately
subsequent occurrences of <backspace>/character pairs for
that same character shall also be discarded. (For example,
the sequence "a\ba\ba\ba" is interpreted as a single
emboldened 'a'.)
* The more utility shall logically discard all other
<backspace> characters from the line as well as the character
which precedes them, if any.
* A <carriage-return> at the end of a line shall be ignored,
rather than being written as a non-printable character, as
described in the next paragraph.
It is implementation-defined how other non-printable characters
are written. Implementations should use the same format that they
use for the ex print command; see the OPTIONS section within the
ed utility. It is unspecified whether a multi-column character
shall be separated if it crosses a display line boundary; it
shall not be discarded. The behavior is unspecified if the number
of columns on the display is less than the number of columns any
single character in the line being displayed would occupy.
When each new file is displayed (or redisplayed), more shall
write the first screen of the file. Once the initial screen has
been written, more shall prompt for a user command. If the
execution of the user command results in a screen that has lines
in common with the current screen, and the device has sufficient
terminal capabilities, more shall scroll the screen; otherwise,
it is unspecified whether the screen is scrolled or redrawn.
For all files but the last (including standard input if no file
was specified, and for the last file as well, if the -e option
was not specified), when more has written the last line in the
file, more shall prompt for a user command. This prompt shall
contain the name of the next file as well as an indication that
more has reached end-of-file. If the user command is f,
<control>‐F, <space>, j, <newline>, d, <control>‐D, or s, more
shall display the next file. Otherwise, if displaying the last
file, more shall exit. Otherwise, more shall execute the user
command specified.
Several of the commands described in this section display a
previous screen from the input stream. In the case that text is
being taken from a non-rewindable stream, such as a pipe, it is
implementation-defined how much backwards motion is supported. If
a command cannot be executed because of a limitation on backwards
motion, an error message to this effect shall be displayed, the
current screen shall not change, and the user shall be prompted
for another command.
If a command cannot be performed because there are insufficient
lines to display, more shall alert the terminal. If a command
cannot be performed because there are insufficient lines to
display or a / command fails: if the input is the standard input,
the last screen in the file may be displayed; otherwise, the
current file and screen shall not change, and the user shall be
prompted for another command.
The interactive commands in the following sections shall be
supported. Some commands can be preceded by a decimal integer,
called count in the following descriptions. If not specified with
the command, count shall default to 1. In the following
descriptions, pattern is a basic regular expression, as described
in the Base Definitions volume of POSIX.1‐2017, Section 9.3,
Basic Regular Expressions. The term ``examine'' is historical
usage meaning ``open the file for viewing''; for example, more
foo would be expressed as examining file foo.
In the following descriptions, unless otherwise specified, line
is a line in the more display, not a line from the file being
examined.
In the following descriptions, the current position refers to two
things:
1. The position of the current line on the screen
2. The line number (in the file) of the current line on the
screen
Usually, the line on the screen corresponding to the current
position is the third line on the screen. If this is not possible
(there are fewer than three lines to display or this is the first
page of the file, or it is the last page of the file), then the
current position is either the first or last line on the screen
as described later.
Help
Synopsis:
h
Write a summary of these commands and other implementation-
defined commands. The behavior shall be as if the more utility
were executed with the -e option on a file that contained the
summary information. The user shall be prompted as described
earlier in this section when end-of-file is reached. If the user
command is one of those specified to continue to the next file,
more shall return to the file and screen state from which the h
command was executed.
Scroll Forward One Screenful
Synopsis:
[count]f
[count]<control>-F
Scroll forward count lines, with a default of one screenful. If
count is more than the screen size, only the final screenful
shall be written.
Scroll Backward One Screenful
Synopsis:
[count]b
[count]<control>-B
Scroll backward count lines, with a default of one screenful (see
the -n option). If count is more than the screen size, only the
final screenful shall be written.
Scroll Forward One Line
Synopsis:
[count]<space>
[count]j
[count]<newline>
Scroll forward count lines. The default count for the <space>
shall be one screenful; for j and <newline>, one line. The entire
count lines shall be written, even if count is more than the
screen size.
Scroll Backward One Line
Synopsis:
[count]k
Scroll backward count lines. The entire count lines shall be
written, even if count is more than the screen size.
Scroll Forward One Half Screenful
Synopsis:
[count]d
[count]<control>-D
Scroll forward count lines, with a default of one half of the
screen size. If count is specified, it shall become the new
default for subsequent d, <control>‐D, and u commands.
Skip Forward One Line
Synopsis:
[count]s
Display the screenful beginning with the line count lines after
the last line on the current screen. If count would cause the
current position to be such that less than one screenful would be
written, the last screenful in the file shall be written.
Scroll Backward One Half Screenful
Synopsis:
[count]u
[count]<control>-U
Scroll backward count lines, with a default of one half of the
screen size. If count is specified, it shall become the new
default for subsequent d, <control>-D, u, and <control>-U
commands. The entire count lines shall be written, even if count
is more than the screen size.
Go to Beginning of File
Synopsis:
[count]g
Display the screenful beginning with line count.
Go to End-of-File
Synopsis:
[count]G
If count is specified, display the screenful beginning with the
line count. Otherwise, display the last screenful of the file.
Refresh the Screen
Synopsis:
r
<control>-L
Refresh the screen.
Discard and Refresh
Synopsis:
R
Refresh the screen, discarding any buffered input. If the current
file is non-seekable, buffered input shall not be discarded and
the R command shall be equivalent to the r command.
Mark Position
Synopsis:
mletter
Mark the current position with the letter named by letter, where
letter represents the name of one of the lowercase letters of the
portable character set. When a new file is examined, all marks
may be lost.
Return to Mark
Synopsis:
'letter
Return to the position that was previously marked with the letter
named by letter, making that line the current position.
Return to Previous Position
Synopsis:
''
Return to the position from which the last large movement command
was executed (where a ``large movement'' is defined as any
movement of more than a screenful of lines). If no such movements
have been made, return to the beginning of the file.
Search Forward for Pattern
Synopsis:
[count]/[!]pattern<newline>
Display the screenful beginning with the countth line containing
the pattern. The search shall start after the first line
currently displayed. The null regular expression ('/' followed by
a <newline>) shall repeat the search using the previous regular
expression, with a default count. If the character '!' is
included, the matching lines shall be those that do not contain
the pattern. If no match is found for the pattern, a message to
that effect shall be displayed.
Search Backward for Pattern
Synopsis:
[count]?[!]pattern<newline>
Display the screenful beginning with the countth previous line
containing the pattern. The search shall start on the last line
before the first line currently displayed. The null regular
expression ('?' followed by a <newline>) shall repeat the search
using the previous regular expression, with a default count. If
the character '!' is included, matching lines shall be those
that do not contain the pattern. If no match is found for the
pattern, a message to that effect shall be displayed.
Repeat Search
Synopsis:
[count]n
Repeat the previous search for countth line containing the last
pattern (or not containing the last pattern, if the previous
search was "/!" or "?!").
Repeat Search in Reverse
Synopsis:
[count]N
Repeat the search in the opposite direction of the previous
search for the countth line containing the last pattern (or not
containing the last pattern, if the previous search was "/!" or
"?!").
Examine New File
Synopsis:
:e [filename]<newline>
Examine a new file. If the filename argument is not specified,
the current file (see the :n and :p commands below) shall be re-
examined. The filename shall be subjected to the process of shell
word expansions (see Section 2.6, Word Expansions); if more than
a single pathname results, the effects are unspecified. If
filename is a <number-sign> ('#'), the previously examined file
shall be re-examined. If filename is not accessible for any
reason (including that it is a non-seekable file), an error
message to this effect shall be displayed and the current file
and screen shall not change.
Examine Next File
Synopsis:
[count]:n
Examine the next file. If a number count is specified, the
countth next file shall be examined. If filename refers to a non-
seekable file, the results are unspecified.
Examine Previous File
Synopsis:
[count]:p
Examine the previous file. If a number count is specified, the
countth previous file shall be examined. If filename refers to a
non-seekable file, the results are unspecified.
Go to Tag
Synopsis:
:t tagstring<newline>
If the file containing the tag named by the tagstring argument is
not the current file, examine the file, as if the :e command was
executed with that file as the argument. Otherwise, or in
addition, display the screenful beginning with the tag, as
described for the -t option (see the OPTIONS section). If the
ctags utility is not supported by the system, the use of :t
produces undefined results.
Invoke Editor
Synopsis:
v
Invoke an editor to edit the current file being examined. If
standard input is being examined, the results are unspecified.
The name of the editor shall be taken from the environment
variable EDITOR, or shall default to vi. If the last pathname
component in EDITOR is either vi or ex, the editor shall be
invoked with a -c linenumber command line argument, where
linenumber is the line number of the file line containing the
display line currently displayed as the first line of the screen.
It is implementation-defined whether line-setting options are
passed to editors other than vi and ex.
When the editor exits, more shall resume with the same file and
screen as when the editor was invoked.
Display Position
Synopsis:
=
<control>-G
Write a message for which the information references the first
byte of the line after the last line of the file on the screen.
This message shall include the name of the file currently being
examined, its number relative to the total number of files there
are to examine, the line number in the file, the byte number and
the total bytes in the file, and what percentage of the file
precedes the current position. If more is reading from standard
input, or the file is shorter than a single screen, the line
number, the byte number, the total bytes, and the percentage need
not be written.
Quit
Synopsis:
q
:q
ZZ
Exit more.
