man/tabs.1 - android_external_libncurses - Gitiles

 .\"***************************************************************************
 .\" 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            *
 .\" "Software"), to deal in the Software without restriction, including      *
 .\" without limitation the rights to use, copy, modify, merge, publish,      *
 .\" distribute, distribute with modifications, sublicense, and/or sell       *
 .\" copies of the Software, and to permit persons to whom the Software is    *
 .\" furnished to do so, subject to the following conditions:                 *
 .\"                                                                          *
 .\" The above copyright notice and this permission notice shall be included  *
 .\" in all copies or substantial portions of the Software.                   *
 .\"                                                                          *
 .\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 .\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 .\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 .\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 .\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 .\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 .\" THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 .\"                                                                          *
 .\" Except as contained in this notice, the name(s) of the above copyright   *
 .\" holders shall not be used in advertising or otherwise to promote the     *
 .\" sale, use or other dealings in this Software without prior written       *
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"
 .\" $Id: tabs.1,v 1.59 2024/04/20 19:08:15 tom Exp $
 .TH @TABS@ 1 2024-04-20 "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
 ..
 .
 .SH NAME
 \fB\%@TABS@\fP \-
 set terminal tab stops
 .SH SYNOPSIS
 \fB@TABS@\fP [\fIoptions\fP] [\fItabstop-list\fP]
 .SH DESCRIPTION
 The \fB@TABS@\fP program clears and sets tab-stops on the terminal.
 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.,
 .PP
 .RS 4
 .EX
 stty tab0
 .EE
 .RE
 .PP
 Like \fB@CLEAR@\fP(1), \fB@TABS@\fP writes to the standard output.
 You can redirect the standard output to a file (which prevents
 \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
 running in the terminal, if at all.
 Curses and other full-screen applications may use hardware tabs
 in optimizing their output to the terminal.
 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
 .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
 .SS "General Options"
 .TP 5
 .BI \-T "name"
 Tell \fB@TABS@\fP which terminal type to use.
 If this option is not given, \fB@TABS@\fP will use the \fB$TERM\fP
 environment variable.
 If that is not set, it will use the \fIansi+tabs\fP entry.
 .TP 5
 .B \-d
 The debugging option shows a ruler line, followed by two data lines.
 The first data line shows the expected tab-stops marked with asterisks.
 The second data line shows the actual tab-stops, marked with asterisks.
 .TP 5
 .B \-n
 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\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.
 .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.).
 Tabs are repeated up to the right margin of the screen.
 .PP
 Use \*(``\fB\-0\fP\*('' to clear all tabs.
 .PP
 Use \*(``\fB\-8\fP\*('' to set tabs to the standard interval.
 .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,
 .PP
 .RS 4
 .EX
 tabs 1,6,11,16,21
 tabs 1 6 11 16 21
 .EE
 .RE
 .PP
 Use a \*(``+\*('' to treat a number
 as an increment relative to the previous value,
 e.g.,
 .PP
 .RS 4
 .EX
 tabs 1,+5,+5,+5,+5
 .EE
 .RE
 .PP
 which is equivalent to the 1,6,11,16,21 example.
 .SS "Predefined Tab Stops"
 POSIX defines several predefined lists of tab stops.
 .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
 .br
 1,10,16,40,72
 .TP 5
 .B \-c
 COBOL, normal format
 .br
 1,8,12,16,20,55
 .TP 5
 .B \-c2
 COBOL compact format
 .br
 1,6,10,14,49
 .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
 .br
 1,7,11,15,19,23
 .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
 .br
 1,10,55
 .TP 5
 .B \-u
 UNIVAC 1100 Assembler
 .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
 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
 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
 .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,
 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
 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,
 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
 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
 \fB\%@INFOCMP@\fP(1M),
 \fB\%@TSET@\fP(1),
 \fB\%curses\fP(3X),
 \fB\%terminfo\fP(5)
	.\"***************************************************************************
	.\" 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 *
	.\" "Software"), to deal in the Software without restriction, including *
	.\" without limitation the rights to use, copy, modify, merge, publish, *
	.\" distribute, distribute with modifications, sublicense, and/or sell *
	.\" copies of the Software, and to permit persons to whom the Software is *
	.\" furnished to do so, subject to the following conditions: *
	.\" *
	.\" The above copyright notice and this permission notice shall be included *
	.\" in all copies or substantial portions of the Software. *
	.\" *
	.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
	.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
	.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
	.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
	.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
	.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
	.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
	.\" *
	.\" Except as contained in this notice, the name(s) of the above copyright *
	.\" holders shall not be used in advertising or otherwise to promote the *
	.\" sale, use or other dealings in this Software without prior written *
	.\" authorization. *
	.\"***************************************************************************
	.\"
	.\" $Id: tabs.1,v 1.59 2024/04/20 19:08:15 tom Exp $
	.TH @TABS@ 1 2024-04-20 "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
	..
	.
	.SH NAME
	\fB\%@TABS@\fP \-
	set terminal tab stops
	.SH SYNOPSIS
	\fB@TABS@\fP [\fIoptions\fP] [\fItabstop-list\fP]
	.SH DESCRIPTION
	The \fB@TABS@\fP program clears and sets tab-stops on the terminal.
	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.,
	.PP
	.RS 4
	.EX
	stty tab0
	.EE
	.RE
	.PP
	Like \fB@CLEAR@\fP(1), \fB@TABS@\fP writes to the standard output.
	You can redirect the standard output to a file (which prevents
	\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
	running in the terminal, if at all.
	Curses and other full-screen applications may use hardware tabs
	in optimizing their output to the terminal.
	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
	.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
	.SS "General Options"
	.TP 5
	.BI \-T "name"
	Tell \fB@TABS@\fP which terminal type to use.
	If this option is not given, \fB@TABS@\fP will use the \fB$TERM\fP
	environment variable.
	If that is not set, it will use the \fIansi+tabs\fP entry.
	.TP 5
	.B \-d
	The debugging option shows a ruler line, followed by two data lines.
	The first data line shows the expected tab-stops marked with asterisks.
	The second data line shows the actual tab-stops, marked with asterisks.
	.TP 5
	.B \-n
	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\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.
	.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.).
	Tabs are repeated up to the right margin of the screen.
	.PP
	Use \(``\fB\-0\fP\('' to clear all tabs.
	.PP
	Use \(``\fB\-8\fP\('' to set tabs to the standard interval.
	.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,
	.PP
	.RS 4
	.EX
	tabs 1,6,11,16,21
	tabs 1 6 11 16 21
	.EE
	.RE
	.PP
	Use a \(``+\('' to treat a number
	as an increment relative to the previous value,
	e.g.,
	.PP
	.RS 4
	.EX
	tabs 1,+5,+5,+5,+5
	.EE
	.RE
	.PP
	which is equivalent to the 1,6,11,16,21 example.
	.SS "Predefined Tab Stops"
	POSIX defines several predefined lists of tab stops.
	.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
	.br
	1,10,16,40,72
	.TP 5
	.B \-c
	COBOL, normal format
	.br
	1,8,12,16,20,55
	.TP 5
	.B \-c2
	COBOL compact format
	.br
	1,6,10,14,49
	.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
	.br
	1,7,11,15,19,23
	.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
	.br
	1,10,55
	.TP 5
	.B \-u
	UNIVAC 1100 Assembler
	.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
	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
	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
	.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,
	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
	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,
	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
	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
	\fB\%@INFOCMP@\fP(1M),
	\fB\%@TSET@\fP(1),
	\fB\%curses\fP(3X),
	\fB\%terminfo\fP(5)