2 ****************************************************************************
3 * Copyright 2018-2019,2020 Thomas E. Dickey *
4 * Copyright 2008-2016,2017 Free Software Foundation, Inc. *
6 * Permission is hereby granted, free of charge, to any person obtaining a *
7 * copy of this software and associated documentation files (the *
8 * "Software"), to deal in the Software without restriction, including *
9 * without limitation the rights to use, copy, modify, merge, publish, *
10 * distribute, distribute with modifications, sublicense, and/or sell *
11 * copies of the Software, and to permit persons to whom the Software is *
12 * furnished to do so, subject to the following conditions: *
14 * The above copyright notice and this permission notice shall be included *
15 * in all copies or substantial portions of the Software. *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
20 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
21 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
22 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
23 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
25 * Except as contained in this notice, the name(s) of the above copyright *
26 * holders shall not be used in advertising or otherwise to promote the *
27 * sale, use or other dealings in this Software without prior written *
29 ****************************************************************************
30 * @Id: tabs.1,v 1.27 2020/02/02 23:34:34 tom Exp @
32 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN">
35 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
36 <meta name="generator" content="Manpage converted by man2html - see https://invisible-island.net/scripts/readme.html#others_scripts">
38 <link rel="author" href="mailto:bug-ncurses@gnu.org">
39 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
42 <H1 class="no-header">tabs 1</H1>
44 <STRONG><A HREF="tabs.1.html">tabs(1)</A></STRONG> General Commands Manual <STRONG><A HREF="tabs.1.html">tabs(1)</A></STRONG>
49 </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
50 <STRONG>tabs</STRONG> - set tabs on a terminal
53 </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
54 <STRONG>tabs</STRONG> [<EM>options</EM>]] <EM>[tabstop-list]</EM>
57 </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
58 The <STRONG>tabs</STRONG> program clears and sets tab-stops on the terminal. This uses
59 the terminfo <EM>clear</EM><STRONG>_</STRONG><EM>all</EM><STRONG>_</STRONG><EM>tabs</EM> and <EM>set</EM><STRONG>_</STRONG><EM>tab</EM> capabilities. If either is
60 absent, <STRONG>tabs</STRONG> is unable to clear/set tab-stops. The terminal should be
61 configured to use hard tabs, e.g.,
65 Like <STRONG><A HREF="clear.1.html">clear(1)</A></STRONG>, <STRONG>tabs</STRONG> writes to the standard output. You can redirect
66 the standard output to a file (which prevents <STRONG>tabs</STRONG> from actually chang-
67 ing the tabstops), and later <STRONG>cat</STRONG> the file to the screen, setting tab-
70 These are hardware tabs, which cannot be queried rapidly by applica-
71 tions running in the terminal, if at all. Curses and other full-screen
72 applications may use hardware tabs in optimizing their output to the
73 terminal. If the hardware tabstops differ from the information in the
74 terminal database, the result is unpredictable. Before running curses
75 programs, you should either reset tab-stops to the standard interval
79 or use the <STRONG>reset</STRONG> program, since the normal initialization sequences do
80 not ensure that tab-stops are reset.
83 </PRE><H2><a name="h2-OPTIONS">OPTIONS</a></H2><PRE>
85 </PRE><H3><a name="h3-General-Options">General Options</a></H3><PRE>
86 <STRONG>-T</STRONG><EM>name</EM>
87 Tell <STRONG>tabs</STRONG> which terminal type to use. If this option is not
88 given, <STRONG>tabs</STRONG> will use the <STRONG>$TERM</STRONG> environment variable. If that is
89 not set, it will use the <EM>ansi+tabs</EM> entry.
91 <STRONG>-d</STRONG> The debugging option shows a ruler line, followed by two data
92 lines. The first data line shows the expected tab-stops marked
93 with asterisks. The second data line shows the actual tab-stops,
94 marked with asterisks.
96 <STRONG>-n</STRONG> This option tells <STRONG>tabs</STRONG> to check the options and run any debugging
97 option, but not to modify the terminal settings.
99 <STRONG>-V</STRONG> reports the version of ncurses which was used in this program, and
102 The <STRONG>tabs</STRONG> program processes a single list of tab stops. The last option
103 to be processed which defines a list is the one that determines the
104 list to be processed.
107 </PRE><H3><a name="h3-Implicit-Lists">Implicit Lists</a></H3><PRE>
108 Use a single number as an option, e.g., "<STRONG>-5</STRONG>" to set tabs at the given
109 interval (in this case 1, 6, 11, 16, 21, etc.). Tabs are repeated up
110 to the right margin of the screen.
112 Use "<STRONG>-0</STRONG>" to clear all tabs.
114 Use "<STRONG>-8</STRONG>" to set tabs to the standard interval.
117 </PRE><H3><a name="h3-Explicit-Lists">Explicit Lists</a></H3><PRE>
118 An explicit list can be defined after the options (this does not use a
119 "-"). The values in the list must be in increasing numeric order, and
120 greater than zero. They are separated by a comma or a blank, for exam-
126 Use a "+" to treat a number as an increment relative to the previous
131 which is equivalent to the 1,6,11,16,21 example.
134 </PRE><H3><a name="h3-Predefined-Tab-Stops">Predefined Tab-Stops</a></H3><PRE>
135 X/Open defines several predefined lists of tab stops.
137 <STRONG>-a</STRONG> Assembler, IBM S/370, first format
139 <STRONG>-a2</STRONG> Assembler, IBM S/370, second format
141 <STRONG>-c</STRONG> COBOL, normal format
143 <STRONG>-c2</STRONG> COBOL compact format
145 <STRONG>-c3</STRONG> COBOL compact format extended
147 <STRONG>-f</STRONG> FORTRAN
149 <STRONG>-p</STRONG> PL/I
151 <STRONG>-s</STRONG> SNOBOL
153 <STRONG>-u</STRONG> UNIVAC 1100 Assembler
156 </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
157 <EM>IEEE</EM> <EM>Std</EM> <EM>1003.1/The</EM> <EM>Open</EM> <EM>Group</EM> <EM>Base</EM> <EM>Specifications</EM> <EM>Issue</EM> <EM>7</EM>
158 (POSIX.1-2008) describes a <STRONG>tabs</STRONG> utility. However
160 <STRONG>o</STRONG> This standard describes a <STRONG>+m</STRONG> option, to set a terminal's left-mar-
161 gin. Very few of the entries in the terminal database provide the
162 <STRONG>smgl</STRONG> (<STRONG>set_left_margin</STRONG>) or <STRONG>smglp</STRONG> (<STRONG>set_left_margin_parm</STRONG>) capability
163 needed to support the feature.
165 <STRONG>o</STRONG> There is no counterpart in X/Open Curses Issue 7 for this utility,
166 unlike <STRONG>tput(1)</STRONG>.
168 The <STRONG>-d</STRONG> (debug) and <STRONG>-n</STRONG> (no-op) options are extensions not provided by
169 other implementations.
171 A <STRONG>tabs</STRONG> utility appeared in PWB/Unix 1.0 (1977). There was a reduced
172 version of the <STRONG>tabs</STRONG> utility in Unix 7th edition and in 3BSD (1979).
173 The latter supported a single "-n" option (to cause the first tab stop
174 to be set on the left margin). That option is not documented by POSIX.
176 The PWB/Unix <STRONG>tabs</STRONG> utility, which was included in System III (1980),
177 used built-in tables rather than the terminal database, to support a
178 half-dozen terminal types. It also had built-in logic to support the
179 left-margin, as well as a feature for copying the tab settings from a
182 Later versions of Unix, e.g., SVr4, added support for the terminal
183 database, but kept the tables, as a fallback. In an earlier develop-
184 ment effort, the tab-stop initialization provided by <STRONG>tset</STRONG> (1982) and
185 incorporated into <STRONG>tput</STRONG> uses the terminal database,
187 POSIX documents no limits on the number of tab stops. Documentation
188 for other implementations states that there is a limit on the number of
189 tab stops (e.g., 20 in PWB/Unix's <STRONG>tabs</STRONG> utility). While some terminals
190 may not accept an arbitrary number of tab stops, this implementation
191 will attempt to set tab stops up to the right margin of the screen, if
192 the given list happens to be that long.
194 The <EM>Rationale</EM> section of the POSIX documentation goes into some detail
195 about the ways the committee considered redesigning the <STRONG>tabs</STRONG> and <STRONG>tput</STRONG>
196 utilities, without proposing an improved solution. It comments that
198 no known historical version of tabs supports the capability of
199 setting arbitrary tab stops.
201 However, the <EM>Explicit</EM> <EM>Lists</EM> described in this manual page were imple-
202 mented in PWB/Unix. Those provide the capability of setting abitrary
206 </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
207 <STRONG><A HREF="tset.1.html">tset(1)</A></STRONG>, <STRONG><A HREF="infocmp.1m.html">infocmp(1m)</A></STRONG>, <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>.
209 This describes <STRONG>ncurses</STRONG> version 6.2 (patch 20200725).
213 <STRONG><A HREF="tabs.1.html">tabs(1)</A></STRONG>
217 <li><a href="#h2-NAME">NAME</a></li>
218 <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
219 <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li>
220 <li><a href="#h2-OPTIONS">OPTIONS</a>
222 <li><a href="#h3-General-Options">General Options</a></li>
223 <li><a href="#h3-Implicit-Lists">Implicit Lists</a></li>
224 <li><a href="#h3-Explicit-Lists">Explicit Lists</a></li>
225 <li><a href="#h3-Predefined-Tab-Stops">Predefined Tab-Stops</a></li>
228 <li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
229 <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>