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.Dd September 9, 2021 26.Dt TABS 1 27.Os 28.Sh NAME 29.Nm tabs 30.Nd set terminal tabs 31.Sh SYNOPSIS 32.Nm 33.Op Fl Ar n | Fl a | a2 | c | c2 | c3 | f | p | s | u 34.Op Cm +m Ns Op Ar n 35.Op Fl T Ar type 36.Nm 37.Op Fl T Ar type 38.Op Cm + Ns Op Ar n 39.Ar n1 Ns Op Ns , Ns Ar n2 , Ns ... 40.Sh DESCRIPTION 41The 42.Nm 43utility displays a series of characters that clear the hardware terminal 44tab settings then initialises tab stops at specified positions, and 45optionally adjusts the margin. 46.Pp 47In the first synopsis form, the tab stops set depend on the command line 48options used, and may be one of the predefined formats or at regular 49intervals. 50.Pp 51In the second synopsis form, tab stops are set at positions 52.Ar n1 , n2 , 53etc. 54If a position is preceded by a 55.Ql + , 56it is relative to the previous position set. 57No more than 20 positions may be specified. 58.Pp 59If no tab stops are specified, the 60.Dq standard 61.Ux 62tab width of 8 is used. 63.Pp 64The options are as follows: 65.Bl -tag -width indent 66.It Fl Ar n 67Set a tab stop every 68.Ar n 69columns. 70If 71.Ar n 72is 0, the tab stops are cleared but no new ones are set. 73.It Fl a 74Assembler format (columns 1, 10, 16, 36, 72). 75.It Fl a2 76Assembler format (columns 1, 10, 16, 40, 72). 77.It Fl c 78.Tn COBOL 79normal format (columns 1, 8, 12, 16, 20, 55) 80.It Fl c2 81.Tn COBOL 82compact format (columns 1, 6, 10, 14, 49) 83.It Fl c3 84.Tn COBOL 85compact format (columns 1, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, 8650, 54, 58, 62, 67). 87.It Fl f 88.Tn FORTRAN 89format (columns 1, 7, 11, 15, 19, 23). 90.It Fl p 91.Tn PL/1 92format (columns 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 9357, 61). 94.It Fl s 95.Tn SNOBOL 96format (columns 1, 10, 55). 97.It Fl u 98Assembler format (columns 1, 12, 20, 44). 99.It Xo 100.Cm +m Ns Op Ar n , 101.Cm + Ns Op Ar n 102.Xc 103Set an 104.Ar n 105character left margin, or 10 if 106.Ar n 107is omitted. 108.It Fl T Ar type 109Output escape sequence for the terminal type 110.Ar type . 111.El 112.Sh ENVIRONMENT 113The 114.Ev LANG , LC_ALL , LC_CTYPE 115and 116.Ev TERM 117environment variables affect the execution of 118.Nm 119as described in 120.Xr environ 7 . 121.Pp 122The 123.Fl T 124option overrides the setting of the 125.Ev TERM 126environment variable. 127If neither 128.Ev TERM 129nor the 130.Fl T 131option are present, 132.Nm 133will fail. 134.Sh EXIT STATUS 135.Ex -std 136.Sh SEE ALSO 137.Xr expand 1 , 138.Xr stty 1 , 139.Xr tput 1 , 140.Xr unexpand 1 , 141.Xr termcap 5 142.Sh STANDARDS 143The 144.Nm 145utility conforms to 146.St -p1003.1-2001 . 147.Sh HISTORY 148.Pa /etc/tabs 149appeared in 150.At v1 151which set tabs every 8 on Teletype model 37 and compatible printing terminals 152when printed. 153A 154.Nm 155utility that worked on many terminals appeared in PWB UNIX. 156This implementation was introduced in 157.Fx 5.0 . 158.Sh BUGS 159The current 160.Xr termcap 5 161database does not define the 162.Ql ML 163(set left soft margin) capability for any terminals. 164