mirror of https://github.com/mkerrisk/man-pages
1070 lines
34 KiB
Groff
1070 lines
34 KiB
Groff
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "MORE" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" more
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.SH NAME
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more \- display files on a page-by-page basis
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.SH SYNOPSIS
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.LP
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\fBmore\fP \fB[\fP\fB-ceisu\fP\fB][\fP\fB-n\fP \fInumber\fP\fB][\fP\fB-p\fP
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\fIcommand\fP\fB][\fP\fB-t\fP \fItagstring\fP\fB][\fP\fIfile\fP \fB...\fP\fB]\fP\fB\fP
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.SH DESCRIPTION
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.LP
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The \fImore\fP utility shall read files and either write them to the
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terminal on a page-by-page basis or filter them to
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standard output. If standard output is not a terminal device, all
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input files shall be copied to standard output in their entirety,
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without modification, except as specified for the \fB-s\fP option.
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If standard output is a terminal device, the files shall be
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written a number of lines (one screenful) at a time under the control
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of user commands. See the EXTENDED DESCRIPTION section.
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.LP
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Certain block-mode terminals do not have all the capabilities necessary
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to support the complete \fImore\fP definition; they are
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incapable of accepting commands that are not terminated with a <newline>.
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Implementations that support such terminals shall
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provide an operating mode to \fImore\fP in which all commands can
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be terminated with a <newline> on those terminals. This
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mode:
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.IP " *" 3
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Shall be documented in the system documentation
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.LP
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.IP " *" 3
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Shall, at invocation, inform the user of the terminal deficiency that
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requires the <newline> usage and provide
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instructions on how this warning can be suppressed in future invocations
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.LP
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.IP " *" 3
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Shall not be required for implementations supporting only fully capable
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terminals
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.LP
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.IP " *" 3
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Shall not affect commands already requiring <newline>s
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.LP
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.IP " *" 3
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Shall not affect users on the capable terminals from using \fImore\fP
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as described in this volume of
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IEEE\ Std\ 1003.1-2001
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.LP
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.SH OPTIONS
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.LP
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The \fImore\fP utility shall conform to the Base Definitions volume
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of IEEE\ Std\ 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
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.LP
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The following options shall be supported:
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.TP 7
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\fB-c\fP
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If a screen is to be written that has no lines in common with the
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current screen, or \fImore\fP is writing its first screen,
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\fImore\fP shall not scroll the screen, but instead shall redraw each
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line of the screen in turn, from the top of the screen to
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the bottom. In addition, if \fImore\fP is writing its first screen,
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the screen shall be cleared. This option may be silently
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ignored on devices with insufficient terminal capabilities.
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.TP 7
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\fB-e\fP
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By default, \fImore\fP shall exit immediately after writing the last
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line of the last file in the argument list. If the
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\fB-e\fP option is specified:
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.RS
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.IP " 1." 4
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If there is only a single file in the argument list and that file
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was completely displayed on a single screen, \fImore\fP shall
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exit immediately after writing the last line of that file.
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.LP
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.IP " 2." 4
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Otherwise, \fImore\fP shall exit only after reaching end-of-file on
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the last file in the argument list twice without an
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intervening operation. See the EXTENDED DESCRIPTION section.
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.LP
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.RE
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.TP 7
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\fB-i\fP
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Perform pattern matching in searches without regard to case; see the
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Base Definitions volume of IEEE\ Std\ 1003.1-2001,
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Section 9.2, Regular Expression General Requirements.
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.TP 7
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\fB-n\ \fP \fInumber\fP
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Specify the number of lines per screenful. The \fInumber\fP argument
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is a positive decimal integer. The \fB-n\fP option shall
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override any values obtained from any other source.
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.TP 7
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\fB-p\ \fP \fIcommand\fP
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Each time a screen from a new file is displayed or redisplayed (including
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as a result of \fImore\fP commands; for example,
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\fB:p\fP), execute the \fImore\fP command(s) in the command arguments
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in the order specified, as if entered by the user after the
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first screen has been displayed. No intermediate results shall be
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displayed (that is, if the command is a movement to a screen
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different from the normal first screen, only the screen resulting
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from the command shall be displayed.) If any of the commands fail
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for any reason, an informational message to this effect shall be written,
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and no further commands specified using the \fB-p\fP
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option shall be executed for this file.
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.TP 7
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\fB-s\fP
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Behave as if consecutive empty lines were a single empty line.
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.TP 7
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\fB-t\ \fP \fItagstring\fP
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Write the screenful of the file containing the tag named by the \fItagstring\fP
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argument. See the \fIctags\fP utility. The tags feature represented
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by \fB-t\fP \fItagstring\fP and the \fB:t\fP command is
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optional. It shall be provided on any system that also provides a
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conforming implementation of \fIctags\fP; otherwise, the use of \fB-t\fP
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produces undefined results.
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.LP
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The filename resulting from the \fB-t\fP option shall be logically
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added as a prefix to the list of command line files, as if
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specified by the user. If the tag named by the \fItagstring\fP argument
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is not found, it shall be an error, and \fImore\fP shall
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take no further action.
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.LP
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If the tag specifies a line number, the first line of the display
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shall contain the beginning of that line. If the tag specifies
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a pattern, the first line of the display shall contain the beginning
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of the matching text from the first line of the file that
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contains that pattern. If the line does not exist in the file or matching
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text is not found, an informational message to this
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effect shall be displayed, and \fImore\fP shall display the default
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screen as if \fB-t\fP had not been specified.
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.LP
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If both the \fB-t\fP \fItagstring\fP and \fB-p\fP \fIcommand\fP options
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are given, the \fB-t\fP \fItagstring\fP shall be
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processed first; that is, the file and starting line for the display
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shall be as specified by \fB-t\fP, and then the \fB-p\fP
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\fImore\fP command shall be executed. If the line (matching text)
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specified by the \fB-t\fP command does not exist (is not
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found), no \fB-p\fP \fImore\fP command shall be executed for this
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file at any time.
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.TP 7
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\fB-u\fP
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Treat a <backspace> as a printable control character, displayed as
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an implementation-defined character sequence (see the
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EXTENDED DESCRIPTION section), suppressing backspacing and the special
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handling that produces underlined or standout mode text on
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some terminal types. Also, do not ignore a <carriage-return> at the
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end of a line.
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.sp
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.SH OPERANDS
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.LP
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The following operand shall be supported:
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.TP 7
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\fIfile\fP
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A pathname of an input file. If no \fIfile\fP operands are specified,
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the standard input shall be used. If a \fIfile\fP is
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\fB'-'\fP , the standard input shall be read at that point in the
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sequence.
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.sp
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.SH STDIN
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.LP
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The standard input shall be used only if no \fIfile\fP operands are
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specified, or if a \fIfile\fP operand is \fB'-'\fP
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\&.
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.SH INPUT FILES
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.LP
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The input files being examined shall be text files. If standard output
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is a terminal, standard error shall be used to read
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commands from the user. If standard output is a terminal, standard
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error is not readable, and command input is needed, \fImore\fP
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may attempt to obtain user commands from the controlling terminal
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(for example, \fB/dev/tty\fP); otherwise, \fImore\fP shall
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terminate with an error indicating that it was unable to read user
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commands. If standard output is not a terminal, no error shall
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result if standard error cannot be opened for reading.
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.SH ENVIRONMENT VARIABLES
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.LP
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The following environment variables shall affect the execution of
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\fImore\fP:
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.TP 7
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\fICOLUMNS\fP
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Override the system-selected horizontal display line size. See the
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Base Definitions volume of IEEE\ Std\ 1003.1-2001,
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Chapter 8, Environment Variables for valid values and results when
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it is unset or
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null.
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.TP 7
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\fIEDITOR\fP
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Used by the \fBv\fP command to select an editor. See the EXTENDED
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DESCRIPTION section.
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.TP 7
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\fILANG\fP
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Provide a default value for the internationalization variables that
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are unset or null. (See the Base Definitions volume of
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IEEE\ Std\ 1003.1-2001, Section 8.2, Internationalization Variables
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for
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the precedence of internationalization variables used to determine
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the values of locale categories.)
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.TP 7
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\fILC_ALL\fP
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If set to a non-empty string value, override the values of all the
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other internationalization variables.
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.TP 7
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\fILC_COLLATE\fP
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.sp
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Determine the locale for the behavior of ranges, equivalence classes,
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and multi-character collating elements within regular
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expressions.
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.TP 7
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\fILC_CTYPE\fP
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Determine the locale for the interpretation of sequences of bytes
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of text data as characters (for example, single-byte as
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opposed to multi-byte characters in arguments and input files) and
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the behavior of character classes within regular
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expressions.
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.TP 7
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\fILC_MESSAGES\fP
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Determine the locale that should be used to affect the format and
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contents of diagnostic messages written to standard error and
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informative messages written to standard output.
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.TP 7
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\fINLSPATH\fP
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Determine the location of message catalogs for the processing of \fILC_MESSAGES
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\&.\fP
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.TP 7
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\fILINES\fP
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Override the system-selected vertical screen size, used as the number
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of lines in a screenful. See the Base Definitions volume
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of IEEE\ Std\ 1003.1-2001, Chapter 8, Environment Variables for valid
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values and
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results when it is unset or null. The \fB-n\fP option shall take precedence
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over the \fILINES\fP variable for determining the
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number of lines in a screenful.
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.TP 7
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\fIMORE\fP
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Determine a string containing options described in the OPTIONS section
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preceded with hyphens and <blank>-separated as on
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the command line. Any command line options shall be processed after
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those in the \fIMORE\fP variable, as if the command line were:
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.sp
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.RS
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.nf
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\fBmore $MORE\fP \fIoptions operands\fP
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.fi
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.RE
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.LP
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The \fIMORE\fP variable shall take precedence over the \fITERM\fP
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and \fILINES\fP variables for determining the number of
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lines in a screenful.
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.TP 7
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\fITERM\fP
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Determine the name of the terminal type. If this variable is unset
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or null, an unspecified default terminal type is used.
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.sp
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.SH ASYNCHRONOUS EVENTS
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.LP
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Default.
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.SH STDOUT
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.LP
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The standard output shall be used to write the contents of the input
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files.
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.SH STDERR
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.LP
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The standard error shall be used for diagnostic messages and user
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commands (see the INPUT FILES section), and, if standard
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output is a terminal device, to write a prompting string. The prompting
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string shall appear on the screen line below the last line
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of the file displayed in the current screenful. The prompt shall contain
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the name of the file currently being examined and shall
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contain an end-of-file indication and the name of the next file, if
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any, when prompting at the end-of-file. If an error or
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informational message is displayed, it is unspecified whether it is
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contained in the prompt. If it is not contained in the prompt,
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it shall be displayed and then the user shall be prompted for a continuation
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character, at which point another message or the user
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prompt may be displayed. The prompt is otherwise unspecified. It is
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unspecified whether informational messages are written for
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other user commands.
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.SH OUTPUT FILES
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.LP
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None.
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.SH EXTENDED DESCRIPTION
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.LP
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The following section describes the behavior of \fImore\fP when the
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standard output is a terminal device. If the standard
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output is not a terminal device, no options other than \fB-s\fP shall
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have any effect, and all input files shall be copied to
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standard output otherwise unmodified, at which time \fImore\fP shall
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exit without further action.
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.LP
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The number of lines available per screen shall be determined by the
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\fB-n\fP option, if present, or by examining values in the
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environment (see the ENVIRONMENT VARIABLES section). If neither method
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yields a number, an unspecified number of lines shall be
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used.
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.LP
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The maximum number of lines written shall be one less than this number,
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because the screen line after the last line written
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shall be used to write a user prompt and user input. If the number
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of lines in the screen is less than two, the results are
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undefined. It is unspecified whether user input is permitted to be
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longer than the remainder of the single line where the prompt
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has been written.
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.LP
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The number of columns available per line shall be determined by examining
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values in the environment (see the ENVIRONMENT
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VARIABLES section), with a default value as described in the Base
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Definitions volume of IEEE\ Std\ 1003.1-2001, Chapter 8, Environment
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Variables.
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.LP
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Lines that are longer than the display shall be folded; the length
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at which folding occurs is unspecified, but should be
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appropriate for the output device. Folding may occur between glyphs
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of single characters that take up multiple display columns.
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.LP
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When standard output is a terminal and \fB-u\fP is not specified,
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\fImore\fP shall treat <backspace>s and
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<carriage-return>s specially:
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.IP " *" 3
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A character, followed first by a sequence of \fIn\fP <backspace>s
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(where \fIn\fP is the same as the number of column
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positions that the character occupies), then by \fIn\fP underscore
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characters ( \fB'_'\fP ), shall cause that character to be
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written as underlined text, if the terminal type supports that. The
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\fIn\fP underscore characters, followed first by \fIn\fP
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<backspace>s, then any character with \fIn\fP column positions, shall
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also cause that character to be written as underlined
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text, if the terminal type supports that.
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.LP
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.IP " *" 3
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A sequence of \fIn\fP <backspace>s (where \fIn\fP is the same as the
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number of column positions that the previous
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character occupies) that appears between two identical printable characters
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shall cause the first of those two characters to be
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written as emboldened text (that is, visually brighter, standout mode,
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or inverse-video mode), if the terminal type supports that,
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and the second to be discarded. Immediately subsequent occurrences
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of <backspace>/ character pairs for that same character
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shall also be discarded. (For example, the sequence \fB"a\\ba\\ba\\ba"\fP
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is interpreted as a single emboldened \fB'a'\fP .)
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.LP
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.IP " *" 3
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The \fImore\fP utility shall logically discard all other <backspace>s
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from the line as well as the character which
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precedes them, if any.
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.LP
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.IP " *" 3
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A <carriage-return> at the end of a line shall be ignored, rather
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than being written as a non-printable character, as
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described in the next paragraph.
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.LP
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.LP
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It is implementation-defined how other non-printable characters are
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written. Implementations should use the same format that
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they use for the \fIex\fP \fBprint\fP command; see the OPTIONS section
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within the \fIed\fP utility. It is unspecified whether a multi-column
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character shall be separated if it crosses a
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display line boundary; it shall not be discarded. The behavior is
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unspecified if the number of columns on the display is less than
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the number of columns any single character in the line being displayed
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would occupy.
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.LP
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When each new file is displayed (or redisplayed), \fImore\fP shall
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write the first screen of the file. Once the initial screen
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has been written, \fImore\fP shall prompt for a user command. If the
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execution of the user command results in a screen that has
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lines in common with the current screen, and the device has sufficient
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terminal capabilities, \fImore\fP shall scroll the screen;
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otherwise, it is unspecified whether the screen is scrolled or redrawn.
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.LP
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For all files but the last (including standard input if no file was
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specified, and for the last file as well, if the \fB-e\fP
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option was not specified), when \fImore\fP has written the last line
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in the file, \fImore\fP shall prompt for a user command.
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This prompt shall contain the name of the next file as well as an
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indication that \fImore\fP has reached end-of-file. If the user
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command is \fBf\fP, <control>-F, <space>, \fBj\fP, <newline>, \fBd\fP,
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<control>-D, or \fBs\fP,
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\fImore\fP shall display the next file. Otherwise, if displaying the
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last file, \fImore\fP shall exit. Otherwise, \fImore\fP
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shall execute the user command specified.
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.LP
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|
Several of the commands described in this section display a previous
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|
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,
|
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an error message to this effect shall be displayed, the
|
|
current screen shall not change, and the user shall be prompted for
|
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another command.
|
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.LP
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|
If a command cannot be performed because there are insufficient lines
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to display, \fImore\fP shall alert the terminal. If a
|
|
command cannot be performed because there are insufficient lines to
|
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display or a \fB/\fP 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.
|
|
.LP
|
|
The interactive commands in the following sections shall be supported.
|
|
Some commands can be preceded by a decimal integer,
|
|
called \fIcount\fP in the following descriptions. If not specified
|
|
with the command, \fIcount\fP shall default to 1. In the
|
|
following descriptions, \fIpattern\fP is a basic regular expression,
|
|
as described in the Base Definitions volume of
|
|
IEEE\ Std\ 1003.1-2001, Section 9.3, Basic Regular Expressions. The
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term "examine" is historical usage meaning "open the file for viewing'';
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|
for example, \fImore\fP \fBfoo\fP would be expressed
|
|
as examining file \fBfoo\fP.
|
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.LP
|
|
In the following descriptions, unless otherwise specified, \fIline\fP
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is a line in the \fImore\fP display, not a line from the
|
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file being examined.
|
|
.LP
|
|
In the following descriptions, the \fIcurrent position\fP refers to
|
|
two things:
|
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.IP " 1." 4
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The position of the current line on the screen
|
|
.LP
|
|
.IP " 2." 4
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The line number (in the file) of the current line on the screen
|
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.LP
|
|
.LP
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|
Usually, the line on the screen corresponding to the current position
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|
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.
|
|
.SS Help
|
|
.TP 7
|
|
\fISynopsis\fP:
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|
.sp
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.RS
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|
.nf
|
|
|
|
\fBh
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Write a summary of these commands and other implementation-defined
|
|
commands. The behavior shall be as if the \fImore\fP utility
|
|
were executed with the \fB-e\fP 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,
|
|
\fImore\fP shall return to the file and screen state from which the
|
|
\fBh\fP command was executed.
|
|
.SS Scroll Forward One Screenful
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBf
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fB<control>-F
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll forward \fIcount\fP lines, with a default of one screenful.
|
|
If \fIcount\fP is more than the screen size, only the final
|
|
screenful shall be written.
|
|
.SS Scroll Backward One Screenful
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBb
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fB<control>-B
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll backward \fIcount\fP lines, with a default of one screenful
|
|
(see the \fB-n\fP option). If \fIcount\fP is more than the
|
|
screen size, only the final screenful shall be written.
|
|
.SS Scroll Forward One Line
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fB<space>
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fBj
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fB<newline>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll forward \fIcount\fP lines. The default \fIcount\fP for the
|
|
<space> shall be one screenful; for \fBj\fP and
|
|
<newline>, one line. The entire \fIcount\fP lines shall be written,
|
|
even if \fIcount\fP is more than the screen size.
|
|
.SS Scroll Backward One Line
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBk
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll backward \fIcount\fP lines. The entire \fIcount\fP lines shall
|
|
be written, even if \fIcount\fP is more than the screen
|
|
size.
|
|
.SS Scroll Forward One Half Screenful
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBd
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fB<control>-D
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll forward \fIcount\fP lines, with a default of one half of the
|
|
screen size. If \fIcount\fP is specified, it shall become
|
|
the new default for subsequent \fBd\fP, <control>-D, and \fBu\fP commands.
|
|
.SS Skip Forward One Line
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBs
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Display the screenful beginning with the line \fIcount\fP lines after
|
|
the last line on the current screen. If \fIcount\fP
|
|
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.
|
|
.SS Scroll Backward One Half Screenful
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBu
|
|
\fP\fB[\fP\fIcount\fP\fB]\fP\fB<control>-U
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Scroll backward \fIcount\fP lines, with a default of one half of the
|
|
screen size. If \fIcount\fP is specified, it shall become
|
|
the new default for subsequent \fBd\fP, <control>-D, \fBu\fP, and
|
|
<control>-U commands. The entire \fIcount\fP lines
|
|
shall be written, even if \fIcount\fP is more than the screen size.
|
|
.SS Go to Beginning of File
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBg
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Display the screenful beginning with line \fIcount\fP.
|
|
.SS Go to End-of-File
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBG
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
If \fIcount\fP is specified, display the screenful beginning with
|
|
the line \fIcount\fP. Otherwise, display the last screenful
|
|
of the file.
|
|
.SS Refresh the Screen
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBr
|
|
<control>-L
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Refresh the screen.
|
|
.SS Discard and Refresh
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBR
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Refresh the screen, discarding any buffered input. If the current
|
|
file is non-seekable, buffered input shall not be discarded
|
|
and the \fBR\fP command shall be equivalent to the \fBr\fP command.
|
|
.SS Mark Position
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBm\fP\fIletter\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Mark the current position with the letter named by \fIletter\fP, where
|
|
\fIletter\fP 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.
|
|
.SS Return to Mark
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB'\fP\fIletter\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Return to the position that was previously marked with the letter
|
|
named by \fIletter\fP, making that line the current
|
|
position.
|
|
.SS Return to Previous Position
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB''
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
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.
|
|
.SS Search Forward for Pattern
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fB/\fP\fB[\fP\fB!\fP\fB]\fP\fIpattern\fP\fB<newline>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Display the screenful beginning with the \fIcount\fPth line containing
|
|
the pattern. The search shall start after the first line
|
|
currently displayed. The null regular expression ( \fB'/'\fP followed
|
|
by a <newline>) shall repeat the search using the
|
|
previous regular expression, with a default \fIcount\fP. If the character
|
|
\fB'!'\fP is included, the matching lines shall be
|
|
those that do not contain the \fIpattern\fP. If no match is found
|
|
for the \fIpattern\fP, a message to that effect shall be
|
|
displayed.
|
|
.SS Search Backward for Pattern
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fB?\fP\fB[\fP\fB!\fP\fB]\fP\fIpattern\fP\fB<newline>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Display the screenful beginning with the \fIcount\fPth previous line
|
|
containing the pattern. The search shall start on the last
|
|
line before the first line currently displayed. The null regular expression
|
|
( \fB'?'\fP followed by a <newline>) shall
|
|
repeat the search using the previous regular expression, with a default
|
|
\fIcount\fP. If the character \fB'!'\fP is included,
|
|
matching lines shall be those that do not contain the \fIpattern\fP.
|
|
If no match is found for the \fIpattern\fP, a message to
|
|
that effect shall be displayed.
|
|
.SS Repeat Search
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBn
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Repeat the previous search for \fIcount\fPth line containing the last
|
|
\fIpattern\fP (or not containing the last
|
|
\fIpattern\fP, if the previous search was \fB"/!"\fP or \fB"?!"\fP
|
|
).
|
|
.SS Repeat Search in Reverse
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fBN
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Repeat the search in the opposite direction of the previous search
|
|
for the \fIcount\fPth line containing the last
|
|
\fIpattern\fP (or not containing the last \fIpattern\fP, if the previous
|
|
search was \fB"/!"\fP or \fB"?!"\fP ).
|
|
.SS Examine New File
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB:e\fP \fB[\fP\fIfilename\fP\fB]\fP\fB<newline>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Examine a new file. If the \fIfilename\fP argument is not specified,
|
|
the current file (see the \fB:n\fP and \fB:p\fP commands
|
|
below) shall be re-examined. The \fIfilename\fP shall be subjected
|
|
to the process of shell word expansions (see \fIWord Expansions\fP
|
|
); if more than a single pathname results, the effects are unspecified.
|
|
If
|
|
\fIfilename\fP is a number sign ( \fB'#'\fP ), the previously examined
|
|
file shall be re-examined. If \fIfilename\fP 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.
|
|
.SS Examine Next File
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fB:n
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Examine the next file. If a number \fIcount\fP is specified, the \fIcount\fPth
|
|
next file shall be examined. If \fIfilename\fP
|
|
refers to a non-seekable file, the results are unspecified.
|
|
.SS Examine Previous File
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB[\fP\fIcount\fP\fB]\fP\fB:p
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Examine the previous file. If a number \fIcount\fP is specified, the
|
|
\fIcount\fPth previous file shall be examined. If
|
|
\fIfilename\fP refers to a non-seekable file, the results are unspecified.
|
|
.SS Go to Tag
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB:t\fP \fItagstring\fP\fB<newline>
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
If the file containing the tag named by the \fItagstring\fP argument
|
|
is not the current file, examine the file, as if the
|
|
\fB:e\fP command was executed with that file as the argument. Otherwise,
|
|
or in addition, display the screenful beginning with the
|
|
tag, as described for the \fB-t\fP option (see the OPTIONS section).
|
|
If the \fIctags\fP
|
|
utility is not supported by the system, the use of \fB:t\fP produces
|
|
undefined results.
|
|
.SS Invoke Editor
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBv
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
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 \fIEDITOR
|
|
,\fP or shall default to \fIvi\fP. If the last pathname component
|
|
in \fIEDITOR\fP is either \fIvi\fP or \fIex\fP, the editor shall be
|
|
invoked with a \fB-c\fP
|
|
\fIlinenumber\fP command line argument, where \fIlinenumber\fP 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 \fIvi\fP and \fIex\fP.
|
|
.LP
|
|
When the editor exits, \fImore\fP shall resume with the same file
|
|
and screen as when the editor was invoked.
|
|
.SS Display Position
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fB=
|
|
<control>-G
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
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 \fImore\fP 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.
|
|
.SS Quit
|
|
.TP 7
|
|
\fISynopsis\fP:
|
|
.sp
|
|
.RS
|
|
.nf
|
|
|
|
\fBq
|
|
:q
|
|
ZZ
|
|
\fP
|
|
.fi
|
|
.RE
|
|
.sp
|
|
.LP
|
|
Exit \fImore\fP.
|
|
.SH EXIT STATUS
|
|
.LP
|
|
The following exit values shall be returned:
|
|
.TP 7
|
|
\ 0
|
|
Successful completion.
|
|
.TP 7
|
|
>0
|
|
An error occurred.
|
|
.sp
|
|
.SH CONSEQUENCES OF ERRORS
|
|
.LP
|
|
If an error is encountered accessing a file when using the \fB:n\fP
|
|
command, \fImore\fP shall attempt to examine the next file
|
|
in the argument list, but the final exit status shall be affected.
|
|
If an error is encountered accessing a file via the \fB:p\fP
|
|
command, \fImore\fP shall attempt to examine the previous file in
|
|
the argument list, but the final exit status shall be affected.
|
|
If an error is encountered accessing a file via the \fB:e\fP command,
|
|
\fImore\fP shall remain in the current file and the final
|
|
exit status shall not be affected.
|
|
.LP
|
|
\fIThe following sections are informative.\fP
|
|
.SH APPLICATION USAGE
|
|
.LP
|
|
When the standard output is not a terminal, only the \fB-s\fP filter-modification
|
|
option is effective. This is based on
|
|
historical practice. For example, a typical implementation of \fIman\fP
|
|
pipes its output
|
|
through \fImore\fP \fB-s\fP to squeeze excess white space for terminal
|
|
users. When \fIman\fP
|
|
is piped to \fIlp\fP, however, it is undesirable for this squeezing
|
|
to happen.
|
|
.SH EXAMPLES
|
|
.LP
|
|
The \fB-p\fP allows arbitrary commands to be executed at the start
|
|
of each file. Examples are:
|
|
.TP 7
|
|
\fImore\ \fP \fB-p\ G\ \fP \fIfile1\ file2\fP
|
|
.sp
|
|
Examine each file starting with its last screenful.
|
|
.TP 7
|
|
\fImore\ \fP \fB-p\ \fP 100\ \fIfile1\ file2\fP
|
|
.sp
|
|
Examine each file starting with line 100 in the current position (usually
|
|
the third line, so line 98 would be the first line
|
|
written).
|
|
.TP 7
|
|
\fImore\ \fP \fB-p\ \fP /100\ \fIfile1\ file2\fP
|
|
.sp
|
|
Examine each file starting with the first line containing the string
|
|
\fB"100"\fP in the current position
|
|
.sp
|
|
.SH RATIONALE
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.LP
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The \fImore\fP utility, available in BSD and BSD-derived systems,
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was chosen as the prototype for the POSIX file display
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program since it is more widely available than either the public-domain
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program \fIless\fP or than \fIpg\fP, a pager provided in
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System V. The 4.4 BSD \fImore\fP is the model for the features selected;
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it is almost fully upwards-compatible from the 4.3 BSD
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version in wide use and has become more amenable for \fIvi\fP users.
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Several features
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originally derived from various file editors, found in both \fIless\fP
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and \fIpg\fP, have been added to this volume of
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IEEE\ Std\ 1003.1-2001 as they have proved extremely popular with
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users.
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.LP
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There are inconsistencies between \fImore\fP and \fIvi\fP that result
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from historical
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practice. For example, the single-character commands \fBh\fP, \fBf\fP,
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\fBb\fP, and <space> are screen movers in
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\fImore\fP, but cursor movers in \fIvi\fP. These inconsistencies were
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maintained because the
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cursor movements are not applicable to \fImore\fP and the powerful
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functionality achieved without the use of the control key
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justifies the differences.
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.LP
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The tags interface has been included in a program that is not a text
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editor because it promotes another degree of consistent
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operation with \fIvi\fP. It is conceivable that the paging environment
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of \fImore\fP would be
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superior for browsing source code files in some circumstances.
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.LP
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The operating mode referred to for block-mode terminals effectively
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adds a <newline> to each Synopsis line that currently
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has none. So, for example, \fBd\fP <newline> would page one screenful.
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The mode could be triggered by a command line option,
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environment variable, or some other method. The details are not imposed
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by this volume of IEEE\ Std\ 1003.1-2001 because
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there are so few systems known to support such terminals. Nevertheless,
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it was considered that all systems should be able to
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support \fImore\fP given the exception cited for this small community
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of terminals because, in comparison to \fIvi\fP, the cursor movements
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are few and the command set relatively amenable to the optional
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<newline>s.
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.LP
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Some versions of \fImore\fP provide a shell escaping mechanism similar
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to the \fIex\fP
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\fB!\fP command. The standard developers did not consider that this
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was necessary in a paginator, particularly given the wide
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acceptance of multiple window terminals and job control features.
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(They chose to retain such features in the editors and \fImailx\fP
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because the shell interaction also gives an opportunity to modify
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the editing buffer,
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which is not applicable to \fImore\fP.)
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.LP
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The \fB-p\fP (position) option replaces the \fB+\fP command because
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of the Utility Syntax Guidelines. In early proposals, it
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took a \fIpattern\fP argument, but historical \fIless\fP provided
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the \fImore\fP general facility of a command. It would have
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been desirable to use the same \fB-c\fP as \fIex\fP and \fIvi\fP,
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but the letter was already in use.
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.LP
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The text stating "from a non-rewindable stream ... implementations
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may limit the amount of backwards motion supported" would
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allow an implementation that permitted no backwards motion beyond
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text already on the screen. It was not possible to require a
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minimum amount of backwards motion that would be effective for all
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conceivable device types. The implementation should allow the
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user to back up as far as possible, within device and reasonable memory
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allocation constraints.
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.LP
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Historically, non-printable characters were displayed using the ARPA
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standard mappings, which are as follows:
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.IP " 1." 4
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Printable characters are left alone.
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.LP
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.IP " 2." 4
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Control characters less than \\177 are represented as followed by
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the character offset from the \fB'@'\fP character in the
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ASCII map; for example, \\007 is represented as \fB'G'\fP .
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.LP
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.IP " 3." 4
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\\177 is represented as followed by \fB'?'\fP .
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.LP
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.LP
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The display of characters having their eighth bit set was less standard.
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Existing implementations use hex (0x00), octal (\\000),
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and a meta-bit display. (The latter displayed characters with their
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eighth bit set as the two characters \fB"M-"\fP , followed
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by the seven-bit display as described previously.) The latter probably
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has the best claim to historical practice because it was
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used with the \fB-v\fP option of 4 BSD and 4 BSD-derived versions
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of the \fIcat\fP utility
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since 1980.
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.LP
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No specific display format is required by IEEE\ Std\ 1003.1-2001.
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Implementations are encouraged to conform to historic
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practice in the absence of any strong reason to diverge.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIShell Command Language\fP , \fIctags\fP , \fIed\fP , \fIex\fP ,
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\fIvi\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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