1.\" Copyright (c) 2002 Tim J. Robbins. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd September 9, 2021 28.Dt TABS 1 29.Os 30.Sh NAME 31.Nm tabs 32.Nd set terminal tabs 33.Sh SYNOPSIS 34.Nm 35.Op Fl Ar n | Fl a | a2 | c | c2 | c3 | f | p | s | u 36.Op Cm +m Ns Op Ar n 37.Op Fl T Ar type 38.Nm 39.Op Fl T Ar type 40.Op Cm + Ns Op Ar n 41.Ar n1 Ns Op Ns , Ns Ar n2 , Ns ... 42.Sh DESCRIPTION 43The 44.Nm 45utility displays a series of characters that clear the hardware terminal 46tab settings then initialises tab stops at specified positions, and 47optionally adjusts the margin. 48.Pp 49In the first synopsis form, the tab stops set depend on the command line 50options used, and may be one of the predefined formats or at regular 51intervals. 52.Pp 53In the second synopsis form, tab stops are set at positions 54.Ar n1 , n2 , 55etc. 56If a position is preceded by a 57.Ql + , 58it is relative to the previous position set. 59No more than 20 positions may be specified. 60.Pp 61If no tab stops are specified, the 62.Dq standard 63.Ux 64tab width of 8 is used. 65.Pp 66The options are as follows: 67.Bl -tag -width indent 68.It Fl Ar n 69Set a tab stop every 70.Ar n 71columns. 72If 73.Ar n 74is 0, the tab stops are cleared but no new ones are set. 75.It Fl a 76Assembler format (columns 1, 10, 16, 36, 72). 77.It Fl a2 78Assembler format (columns 1, 10, 16, 40, 72). 79.It Fl c 80.Tn COBOL 81normal format (columns 1, 8, 12, 16, 20, 55) 82.It Fl c2 83.Tn COBOL 84compact format (columns 1, 6, 10, 14, 49) 85.It Fl c3 86.Tn COBOL 87compact format (columns 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 8850, 54, 58, 62, 67). 89.It Fl f 90.Tn FORTRAN 91format (columns 1, 7, 11, 15, 19, 23). 92.It Fl p 93.Tn PL/1 94format (columns 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 9557, 61). 96.It Fl s 97.Tn SNOBOL 98format (columns 1, 10, 55). 99.It Fl u 100Assembler format (columns 1, 12, 20, 44). 101.It Xo 102.Cm +m Ns Op Ar n , 103.Cm + Ns Op Ar n 104.Xc 105Set an 106.Ar n 107character left margin, or 10 if 108.Ar n 109is omitted. 110.It Fl T Ar type 111Output escape sequence for the terminal type 112.Ar type . 113.El 114.Sh ENVIRONMENT 115The 116.Ev LANG , LC_ALL , LC_CTYPE 117and 118.Ev TERM 119environment variables affect the execution of 120.Nm 121as described in 122.Xr environ 7 . 123.Pp 124The 125.Fl T 126option overrides the setting of the 127.Ev TERM 128environment variable. 129If neither 130.Ev TERM 131nor the 132.Fl T 133option are present, 134.Nm 135will fail. 136.Sh EXIT STATUS 137.Ex -std 138.Sh SEE ALSO 139.Xr expand 1 , 140.Xr stty 1 , 141.Xr tput 1 , 142.Xr unexpand 1 , 143.Xr termcap 5 144.Sh STANDARDS 145The 146.Nm 147utility conforms to 148.St -p1003.1-2001 . 149.Sh HISTORY 150.Pa /etc/tabs 151appeared in 152.At v1 153which set tabs every 8 on Teletype model 37 and compatible printing terminals 154when printed. 155A 156.Nm 157utility that worked on many terminals appeared in PWB UNIX. 158This implementation was introduced in 159.Fx 5.0 . 160.Sh BUGS 161The current 162.Xr termcap 5 163database does not define the 164.Ql ML 165(set left soft margin) capability for any terminals. 166