1.\" $OpenBSD: expand.1,v 1.20 2014/03/17 21:48:51 jmc Exp $ 2.\" $NetBSD: expand.1,v 1.3 1995/09/02 06:19:45 jtc Exp $ 3.\" 4.\" Copyright (c) 1980, 1990, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)expand.1 8.1 (Berkeley) 6/9/93 32.\" 33.Dd $Mdocdate: March 17 2014 $ 34.Dt EXPAND 1 35.Os 36.Sh NAME 37.Nm expand , 38.Nm unexpand 39.Nd expand tabs to spaces, and vice versa 40.Sh SYNOPSIS 41.Nm expand 42.Op Fl t Ar tablist 43.Op Ar 44.Nm unexpand 45.Op Fl a 46.Op Ar 47.Sh DESCRIPTION 48.Nm expand 49processes the named files or the standard input, 50writing the standard output with tabs changed into blanks. 51Backspace characters are preserved into the output and decrement 52the column count for tab calculations. 53.Nm expand 54is useful for pre-processing character files 55(before sorting, looking at specific columns, etc.) that 56contain tabs. 57.Pp 58.Nm unexpand 59puts tabs back into the data from the standard input or the named 60files and writes the result on the standard output. 61.Pp 62The options are as follows: 63.Bl -tag -width flag 64.It Fl a 65By default, only leading blanks and tabs 66are reconverted to maximal strings of tabs. 67If the 68.Fl a 69option is given, tabs are inserted whenever they would compress the 70resultant file by replacing two or more characters. 71.It Fl t Ar tablist 72If the argument to 73.Fl t , 74.Ar tablist , 75consists of a single numerical argument, tabs are set 76.Ar tablist 77spaces apart instead of the default 8. 78If multiple 79.Fl t 80options are given, then the tabs are set at those 81specific columns. 82.Pp 83Otherwise the argument to 84.Fl t 85may consist of a list 86of two or more positive decimal integers, 87separated by commas or single blank characters, 88in ascending order: 89in the event of having to process a 90.Aq tab 91at a position beyond the last of those specified in a multiple 92.Fl t 93list, 94the 95.Aq tab 96is replaced by a single 97.Aq space 98character. 99.Pp 100This implementation of 101.Nm 102additionally allows 103.Ar tablist 104to be specified without using the 105.Fl t 106flag, by prefixing 107.Ar tablist 108with a dash 109.Pq - . 110.El 111.Sh EXIT STATUS 112.Ex -std expand unexpand 113.Sh SEE ALSO 114.Xr fold 1 115.Sh STANDARDS 116The 117.Nm 118and 119.Nm unexpand 120utilities are compliant with the 121.St -p1003.1-2008 122specification, 123except that this implementation does not support a 124.Fl t 125flag for 126.Nm unexpand . 127.Pp 128The ability to specify tabstops without the 129.Fl t 130flag is not specified by 131.St -p1003.1-2008 , 132though it states it 133.Dq may be present in some implementations . 134.Sh HISTORY 135The 136.Nm expand 137utility first appeared in 138.Bx 1 . 139