ncurses 6.5 - patch 20240622

[ncurses.git] / man / tabs.1

diff --git a/man/tabs.1 b/man/tabs.1
index 56d49358564ddf96f3c97ec190fb0174b8782187..11686039989e54d0ded7e49579bbebab1ceca219 100644 (file)
--- a/man/tabs.1
+++ b/man/tabs.1
@@ -1,5 +1,6 @@
 .\"***************************************************************************
 .\"***************************************************************************

-.\" Copyright (c) 2008-2018,2019 Free Software Foundation, Inc.              *
+.\" Copyright 2018-2023,2024 Thomas E. Dickey                                *
+.\" Copyright 2008-2016,2017 Free Software Foundation, Inc.                  *

 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" copy of this software and associated documentation files (the            *
 .\"                                                                          *
 .\" Permission is hereby granted, free of charge, to any person obtaining a  *
 .\" copy of this software and associated documentation files (the            *


@@ -26,48 +27,44 @@
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: tabs.1,v 1.26 2019/06/23 21:01:12 tom Exp $
-.TH @TABS@ 1 ""
-.ds n 5
-.ie \n(.g .ds `` \(lq
-.el       .ds `` ``
-.ie \n(.g .ds '' \(rq
-.el       .ds '' ''
+.\" $Id: tabs.1,v 1.61 2024/06/22 22:15:32 tom Exp $
+.TH @TABS@ 1 2024-06-22 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "User commands"
+.ie \n(.g \{\
+.ds `` \(lq
+.ds '' \(rq
+.\}
+.el \{\
+.ie t .ds `` ``
+.el   .ds `` ""
+.ie t .ds '' ''
+.el   .ds '' ""
+.\}
+.

 .de bP
 .ie n  .IP \(bu 4
 .el    .IP \(bu 2
 ..
 .de bP
 .ie n  .IP \(bu 4
 .el    .IP \(bu 2
 ..

-.de NS
-.ie n  .sp
-.el    .sp .5
-.ie n  .in +4
-.el    .in +2
-.nf
-.ft C                  \" Courier
-..
-.de NE
-.fi
-.ft R
-.ie n  .in -4
-.el    .in -2
-..
+.

 .SH NAME
 .SH NAME

-\fB@TABS@\fR \- set tabs on a terminal
+\fB\%@TABS@\fP \-
+set terminal tab stops

 .SH SYNOPSIS
 .SH SYNOPSIS

-\fB@TABS@\fR [\fIoptions\fR]] \fI[tabstop-list]\fR
+\fB@TABS@\fP [\fIoptions\fP] [\fItabstop-list\fP]

 .SH DESCRIPTION
 .SH DESCRIPTION

-.PP

 The \fB@TABS@\fP program clears and sets tab-stops on the terminal.
 The \fB@TABS@\fP program clears and sets tab-stops on the terminal.

-This uses the terminfo \fIclear_all_tabs\fP and \fIset_tab\fP capabilities.
+This uses the terminfo \fBclear_all_tabs\fP and \fBset_tab\fP capabilities.

 If either is absent, \fB@TABS@\fP is unable to clear/set tab-stops.
 The terminal should be configured to use hard tabs, e.g.,
 If either is absent, \fB@TABS@\fP is unable to clear/set tab-stops.
 The terminal should be configured to use hard tabs, e.g.,

-.NS
+.PP
+.RS 4
+.EX

 stty tab0
 stty tab0

-.NE
+.EE
+.RE

 .PP
 .PP

-Like \fB@CLEAR@\fR(1), \fB@TABS@\fR writes to the standard output.
+Like \fB@CLEAR@\fP(1), \fB@TABS@\fP writes to the standard output.

 You can redirect the standard output to a file (which prevents
 You can redirect the standard output to a file (which prevents

-\fB@TABS@\fR from actually changing the tabstops),
+\fB@TABS@\fP from actually changing the tabstops),

 and later \fBcat\fP the file to the screen, setting tabstops at that point.
 .PP
 These are hardware tabs, which cannot be queried rapidly by applications
 and later \fBcat\fP the file to the screen, setting tabstops at that point.
 .PP
 These are hardware tabs, which cannot be queried rapidly by applications


@@ -78,15 +75,18 @@ If the hardware tabstops differ from the information in the terminal
 database, the result is unpredictable.
 Before running curses programs,
 you should either reset tab-stops to the standard interval
 database, the result is unpredictable.
 Before running curses programs,
 you should either reset tab-stops to the standard interval

-.NS
-tabs -8
-.NE
+.PP
+.RS 4
+.EX
+tabs \-8
+.EE
+.RE

 .PP
 or use the \fB@RESET@\fP program,
 since the normal initialization sequences do not ensure that tab-stops
 are reset.
 .SH OPTIONS
 .PP
 or use the \fB@RESET@\fP program,
 since the normal initialization sequences do not ensure that tab-stops
 are reset.
 .SH OPTIONS

-.SS General Options
+.SS "General Options"

 .TP 5
 .BI \-T "name"
 Tell \fB@TABS@\fP which terminal type to use.
 .TP 5
 .BI \-T "name"
 Tell \fB@TABS@\fP which terminal type to use.


@@ -103,13 +103,14 @@ The second data line shows the actual tab-stops, marked with asterisks.
 This option tells \fB@TABS@\fP to check the options and run any debugging
 option, but not to modify the terminal settings.
 .TP
 This option tells \fB@TABS@\fP to check the options and run any debugging
 option, but not to modify the terminal settings.
 .TP

-\fB\-V\fR
-reports the version of ncurses which was used in this program, and exits.
+\fB\-V\fP
+reports the version of \fI\%ncurses\fP which was used in this program,
+and exits.

 .PP
 The \fB@TABS@\fP program processes a single list of tab stops.
 The last option to be processed which defines a list is the one that
 determines the list to be processed.
 .PP
 The \fB@TABS@\fP program processes a single list of tab stops.
 The last option to be processed which defines a list is the one that
 determines the list to be processed.

-.SS Implicit Lists
+.SS "Implicit Lists"

 Use a single number as an option,
 e.g., \*(``\fB\-5\fP\*('' to set tabs at the given
 interval (in this case 1, 6, 11, 16, 21, etc.).
 Use a single number as an option,
 e.g., \*(``\fB\-5\fP\*('' to set tabs at the given
 interval (in this case 1, 6, 11, 16, 21, etc.).


@@ -118,120 +119,239 @@ Tabs are repeated up to the right margin of the screen.
 Use \*(``\fB\-0\fP\*('' to clear all tabs.
 .PP
 Use \*(``\fB\-8\fP\*('' to set tabs to the standard interval.
 Use \*(``\fB\-0\fP\*('' to clear all tabs.
 .PP
 Use \*(``\fB\-8\fP\*('' to set tabs to the standard interval.

-.SS Explicit Lists
+.SS "Explicit Lists"

 An explicit list can be defined after the options
 (this does not use a \*(``\-\*('').
 The values in the list must be in increasing numeric order,
 and greater than zero.
 They are separated by a comma or a blank, for example,
 An explicit list can be defined after the options
 (this does not use a \*(``\-\*('').
 The values in the list must be in increasing numeric order,
 and greater than zero.
 They are separated by a comma or a blank, for example,

-.NS
+.PP
+.RS 4
+.EX

 tabs 1,6,11,16,21
 tabs 1,6,11,16,21

-.br

 tabs 1 6 11 16 21
 tabs 1 6 11 16 21

-.NE
+.EE
+.RE

 .PP
 Use a \*(``+\*('' to treat a number
 as an increment relative to the previous value,
 e.g.,
 .PP
 Use a \*(``+\*('' to treat a number
 as an increment relative to the previous value,
 e.g.,

-.NS
+.PP
+.RS 4
+.EX

 tabs 1,+5,+5,+5,+5
 tabs 1,+5,+5,+5,+5

-.NE
+.EE
+.RE

 .PP
 which is equivalent to the 1,6,11,16,21 example.
 .PP
 which is equivalent to the 1,6,11,16,21 example.

-.SS Predefined Tab-Stops
-X/Open defines several predefined lists of tab stops.
+.SS "Predefined Tab Stops"
+POSIX defines several predefined lists of tab stops.

 .TP 5
 .B \-a
 Assembler, IBM S/370, first format
 .TP 5
 .B \-a
 Assembler, IBM S/370, first format

+.br
+1,10,16,36,72

 .TP 5
 .B \-a2
 Assembler, IBM S/370, second format
 .TP 5
 .B \-a2
 Assembler, IBM S/370, second format

+.br
+1,10,16,40,72

 .TP 5
 .B \-c
 COBOL, normal format
 .TP 5
 .B \-c
 COBOL, normal format

+.br
+1,8,12,16,20,55

 .TP 5
 .B \-c2
 COBOL compact format
 .TP 5
 .B \-c2
 COBOL compact format

+.br
+1,6,10,14,49

 .TP 5
 .B \-c3
 COBOL compact format extended
 .TP 5
 .B \-c3
 COBOL compact format extended

+.br
+1,6,10,14,18,22,26,30,34,38,42,46,50,54,58,62,67

 .TP 5
 .B \-f
 FORTRAN
 .TP 5
 .B \-f
 FORTRAN

+.br
+1,7,11,15,19,23

 .TP 5
 .B \-p
 PL/I
 .TP 5
 .B \-p
 PL/I

+.br
+1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61

 .TP 5
 .B \-s
 SNOBOL
 .TP 5
 .B \-s
 SNOBOL

+.br
+1,10,55

 .TP 5
 .B \-u
 UNIVAC 1100 Assembler
 .TP 5
 .B \-u
 UNIVAC 1100 Assembler

-.SH PORTABILITY
+.br
+1,12,20,44
+.SS Margins
+A few terminals expose a means of changing their left and right margins.
+\fB@TABS@\fP supports this feature with an option.
+.TP 5
+.BI +m \ margin
+The effect depends on whether the terminal has the margin capabilities:
+.RS
+.bP
+If the terminal provides the capability for setting the left margin,
+\fB@TABS@\fP uses this,
+and adjusts the available tab stop widths.
+.bP
+If the terminal does not provide the margin capabilities,
+\fB@TABS@\fP imitates their effect,
+putting tab stops at appropriate places on each line.
+The terminal's left margin is not modified.
+.RE
+.IP
+If the
+.I margin
+parameter is omitted,
+the default is 10.
+Use
+.B +m0
+to reset the left margin,
+that is,
+to make it the left edge of the terminal's display.
+Before setting a left margin,
+\fB@TABS@\fP resets the margin to reduce problems that might arise
+from moving the cursor to the left of the current left margin.

 .PP
 .PP

-\fIIEEE Std 1003.1/The Open Group Base Specifications Issue 7\fP (POSIX.1-2008)
-describes a \fBtabs\fP utility.
-However
+When setting or resetting the left margin,
+\fB@TABS@\fP may also reset the right margin.
+.SH FILES
+.TP
+.I @DATADIR@/tabset
+tab stop initialization database
+.SH PORTABILITY
+IEEE Std 1003.1/The Open Group Base Specifications Issue 7
+(POSIX.1-2008)
+describes a
+.B tabs
+utility.
+However,

 .bP
 .bP

-This standard describes a \fB+m\fP option, to set a terminal's left-margin.
+this standard describes a
+.B +m
+option to set a terminal's left margin.

 Very few of the entries in the terminal database provide the
 Very few of the entries in the terminal database provide the

-\fBsmgl\fP (\fBset_left_margin\fP) or
-\fBsmglp\fP (\fBset_left_margin_parm\fP)
-capability needed to support the feature.
+.B \%set_left_margin
+.RB ( smgl )
+or
+.B \%set_left_margin_parm
+.RB \%( smglp )
+capabilities needed to support the feature.

 .bP
 There is no counterpart in X/Open Curses Issue 7 for this utility,
 .bP
 There is no counterpart in X/Open Curses Issue 7 for this utility,

-unlike \fB@TPUT@(1)\fP.
-.PP
-The \fB\-d\fP (debug) and \fB\-n\fP (no-op) options are extensions not provided
-by other implementations.
-.PP
-A \fBtabs\fP utility appeared in PWB/Unix 1.0 (1977).
-There was a reduced version of the \fBtabs\fP utility
-in Unix 7th edition and in 3BSD (1979).
-The latter supported a single \*(``\-n\*('' option
-(to cause the first tab stop to be set on the left margin).
-That option is not documented by POSIX.
-.PP
-The PWB/Unix \fBtabs\fP utility, which was included in System III (1980),
-used built-in tables rather than the terminal database,
-to support a half-dozen terminal types.
-It also had built-in logic to support the left-margin,
+unlike \fB@TPUT@\fP(1).
+.PP
+The
+.B \-d
+(debug) and
+.B \-n
+(no-op) options are
+.I \%ncurses
+extensions not provided by other implementations.
+.SH HISTORY
+A
+.B tabs
+utility appeared in PWB/Unix 1.0 (1977).
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=PWB1/sys/source/s2/\
+.\"   tabs.c
+A reduced version shipped in Seventh Edition Unix
+(early 1979)
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src/cmd/tabs.c
+and in 3BSD
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=3BSD/usr/src/cmd/\
+.\"   tabs.c
+(later the same year);
+it supported a \*(``\-n\*('' option to set the first tab stop at the
+left margin.
+That option is not specified by POSIX.
+.PP
+The PWB/Unix
+.B tabs
+utility returned in System III (1980),
+and used built-in tables
+to support a half-dozen hardcopy terminal (printer) types.
+It also had logic to support setting the left margin,

 as well as a feature for copying the tab settings from a file.
 .PP
 as well as a feature for copying the tab settings from a file.
 .PP

-Later versions of Unix, e.g., SVr4,
+Versions of the program in later releases of AT&T Unix,
+such as SVr4,
+.\" https://minnie.tuhs.org/cgi-bin/utree.pl?file=SysVR4/cmd/tabs/tabs.c

 added support for the terminal database,
 added support for the terminal database,

-but kept the tables, as a fallback.
-In an earlier development effort,
-the tab-stop initialization provided by \fBtset\fP (1982)
-and incorporated into \fBtput\fP uses the terminal database,
-.PP
-POSIX documents no limits on the number of tab stops.
-Documentation for other implementations states that there is a limit on the
-number of tab stops
-(e.g., 20 in PWB/Unix's \fBtabs\fP utility).
-While some terminals may not accept an arbitrary number
-of tab stops, this implementation will attempt to set tab stops up to the
-right margin of the screen, if the given list happens to be that long.
-.PP
-The \fIRationale\fP section of the POSIX documentation goes into some
-detail about the ways the committee considered redesigning the
-\fBtabs\fP and \fBtput\fP utilities,
-without proposing an improved solution.
-It comments that
-.RS 5
-.PP
-no known historical version of tabs supports the capability of setting
-arbitrary tab stops.
+but retained the tables to support the printers.
+By this time,
+System\ V
+.B tput
+had incorporated the tab stop initialization feature of BSD's
+.B tset
+from 1982,
+but employed the
+.I \%term\%info
+database to do so.
+.PP
+The
+.B +m
+option was documented in the POSIX Base Specifications Issue 5
+(Unix98, 1997),
+then omitted in Issue 6
+(Unix03, 2004)
+without express motivation,
+though an introductory comment
+\*(``and optionally adjusts the margin\*('' remains,
+overlooked in the removal.
+The
+.B tabs
+utility documented in Issues 6 and later has no mechanism for setting
+margins.
+The
+.B +m
+option in
+.I \%ncurses
+\fB\%@TABS@\fP differs from the SVr4 feature by using terminal
+capabilities rather than built-in tables.
+.PP
+POSIX documents no limit on the number of tab stops.
+Other implementations impose one;
+the limit is 20 in PWB/Unix's
+.B tabs
+utility.
+While some terminals may not accept an arbitrary number of tab stops,
+.I \%ncurses
+\fB\%@TABS@\fP attempts to set tab stops up to the right margin if the
+list thereof is sufficiently long.
+.PP
+The \*(``Rationale\*('' section of the Issue 6
+.B tabs
+reference page
+.\" https://pubs.opengroup.org/onlinepubs/009604499/utilities/tabs.html
+details how the committee considered redesigning the
+.B tabs
+and
+.B tput
+utilities,
+without settling on an improved solution.
+It claims that
+.PP
+.RS 4
+no known historical version of
+.I tabs
+supports the capability of setting arbitrary tab stops.

 .RE
 .PP
 .RE
 .PP

-However, the \fIExplicit Lists\fP described in this manual page
-were implemented in PWB/Unix.
-Those provide the capability of setting abitrary tab stops.
+The feature described in subsection \*(``Explicit Lists\*('' above was
+implemented in PWB/Unix,
+.\" see URL above
+and permitted the setting of abitrary tab stops nevertheless.

 .SH SEE ALSO
 .SH SEE ALSO

-\fB@TSET@\fR(1),
-\fB@INFOCMP@\fR(1M),
-\fBcurses\fR(3X),
-\fBterminfo\fR(\*n).
-.PP
-This describes \fBncurses\fR
-version @NCURSES_MAJOR@.@NCURSES_MINOR@ (patch @NCURSES_PATCH@).
+\fB\%@INFOCMP@\fP(1M),
+\fB\%@TSET@\fP(1),
+\fB\%curses\fP(3X),
+\fB\%terminfo\fP(5)