1.\" Copyright (c) 1980, 1993 2.\" The Regents of the University of California. 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.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)fold.1 8.1 (Berkeley) 6/6/93 29.\" 30.Dd October 29, 2020 31.Dt FOLD 1 32.Os 33.Sh NAME 34.Nm fold 35.Nd "fold long lines for finite width output device" 36.Sh SYNOPSIS 37.Nm 38.Op Fl bs 39.Op Fl w Ar width 40.Op Ar 41.Sh DESCRIPTION 42The 43.Nm 44utility is a filter which folds the contents of the specified files, 45or the standard input if no files are specified, 46breaking the lines to have a maximum of 80 columns. 47.Pp 48The options are as follows: 49.Bl -tag -width indent 50.It Fl b 51Count 52.Ar width 53in bytes rather than column positions. 54.It Fl s 55Fold line after the last blank character within the first 56.Ar width 57column positions (or bytes). 58.It Fl w Ar width 59Specify a line width to use instead of the default 80 columns. 60The 61.Ar width 62value 63should be a multiple of 8 if tabs are present, or the tabs should 64be expanded using 65.Xr expand 1 66before using 67.Nm . 68.El 69.Sh ENVIRONMENT 70The 71.Ev LANG , LC_ALL 72and 73.Ev LC_CTYPE 74environment variables affect the execution of 75.Nm 76as described in 77.Xr environ 7 . 78.Sh EXAMPLES 79Fold text in standard input with a width of 20 columns: 80.Bd -literal -offset indent 81$ echo "I am smart enough to know that I am dumb" | fold -w 15 82I am smart enou 83gh to know that 84 I am dumb 85.Ed 86.Pp 87Same as above but breaking lines after the last blank character: 88.Bd -literal -offset indent 89$ echo "I am smart enough to know that I am dumb" | fold -s -w 15 90I am smart 91enough to know 92that I am dumb 93.Ed 94.Sh SEE ALSO 95.Xr expand 1 , 96.Xr fmt 1 97.Sh STANDARDS 98The 99.Nm 100utility conforms to 101.St -p1003.1-2001 . 102.Sh HISTORY 103The 104.Nm 105utility first appeared in 106.Bx 1 . 107It was rewritten for 108.Bx 4.3 Reno 109to improve speed and modernize style. 110The 111.Fl b 112and 113.Fl s 114options were added to 115.Nx 1.0 116for 117.St -p1003.2 118compliance. 119.Sh AUTHORS 120.An -nosplit 121.An Bill Joy 122wrote the original version of 123.Nm 124on June 28, 1977. 125.An Kevin Ruddy 126rewrote the command in 1990, and 127.An J. T. Conklin 128added the missing options in 1993. 129.Sh BUGS 130If underlining (see 131.Xr ul 1 ) 132is present it may be messed up by folding. 133