.\"***************************************************************************
-.\" Copyright (c) 2008-2010,2011 Free Software Foundation, Inc. *
+.\" Copyright (c) 2008-2018,2019 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: tabs.1,v 1.9 2011/12/17 23:31:59 tom Exp $
+.\" $Id: tabs.1,v 1.20 2019/02/16 23:56:38 tom Exp $
.TH @TABS@ 1 ""
.ds n 5
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
+.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
\fB@TABS@\fR \- set tabs on a terminal
.SH SYNOPSIS
-\fB@TABS@\fR [\fB\-v\fR[\fIn\fR]] [\fB\-ahuUV\fR] \fIfile...\fR
-.br
+\fB@TABS@\fR [\fIoptions\fR]] \fI[tabstop-list]\fR
.SH DESCRIPTION
.PP
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.
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.,
-.sp
-.RS
+.NS
stty tab0
-.RE
+.NE
+.PP
+Like \fB@CLEAR@\fR(1), \fB@TABS@\fR writes to the standard output.
+You can redirect the standard output to a file (which prevents
+\fB@TABS@\fR 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.
.SH OPTIONS
.SS General Options
.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\fR
+reports the version of ncurses 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.
+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.
+Use \*(``\fB\-0\fP\*('' to clear all tabs.
.PP
-Use "\fB\-8\fP" to set tabs to the standard interval.
+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,
-.sp
-.RS
+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
tabs 1,6,11,16,21
.br
tabs 1 6 11 16 21
-.RE
-Use a '+' to treat a number as an increment relative to the previous value,
+.NE
+.PP
+Use a \*(``+\*('' to treat a number
+as an increment relative to the previous value,
e.g.,
-.sp
-.RS
+.NS
tabs 1,+5,+5,+5,+5
-.RE
+.NE
+.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.
UNIVAC 1100 Assembler
.SH PORTABILITY
.PP
-X/Open describes a \fB+m\fP option, to set a terminal's left-margin.
+\fIIEEE Std 1003.1/The Open Group Base Specifications Issue 7\fP (POSIX.1-2008)
+describes a \fBtabs\fP utility.
+However
+.bP
+This standard describes a \fB+m\fP option, to set a terminal's left-margin.
Very few of the entries in the terminal database provide this capability.
+.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
Documentation for other implementations states that there is a limit on the
-number of tab stops. While some terminals may not accept an arbitrary number
+number of tab stops.
+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.
.SH SEE ALSO
projects / ncurses.git / blobdiff