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.Dd October 29, 2020 29.Dt FOLD 1 30.Os 31.Sh NAME 32.Nm fold 33.Nd "fold long lines for finite width output device" 34.Sh SYNOPSIS 35.Nm 36.Op Fl bs 37.Op Fl w Ar width 38.Op Ar 39.Sh DESCRIPTION 40The 41.Nm 42utility is a filter which folds the contents of the specified files, 43or the standard input if no files are specified, 44breaking the lines to have a maximum of 80 columns. 45.Pp 46The options are as follows: 47.Bl -tag -width indent 48.It Fl b 49Count 50.Ar width 51in bytes rather than column positions. 52.It Fl s 53Fold line after the last blank character within the first 54.Ar width 55column positions (or bytes). 56.It Fl w Ar width 57Specify a line width to use instead of the default 80 columns. 58The 59.Ar width 60value 61should be a multiple of 8 if tabs are present, or the tabs should 62be expanded using 63.Xr expand 1 64before using 65.Nm . 66.El 67.Sh ENVIRONMENT 68The 69.Ev LANG , LC_ALL 70and 71.Ev LC_CTYPE 72environment variables affect the execution of 73.Nm 74as described in 75.Xr environ 7 . 76.Sh EXAMPLES 77Fold text in standard input with a width of 20 columns: 78.Bd -literal -offset indent 79$ echo "I am smart enough to know that I am dumb" | fold -w 15 80I am smart enou 81gh to know that 82 I am dumb 83.Ed 84.Pp 85Same as above but breaking lines after the last blank character: 86.Bd -literal -offset indent 87$ echo "I am smart enough to know that I am dumb" | fold -s -w 15 88I am smart 89enough to know 90that I am dumb 91.Ed 92.Sh SEE ALSO 93.Xr expand 1 , 94.Xr fmt 1 95.Sh STANDARDS 96The 97.Nm 98utility conforms to 99.St -p1003.1-2001 . 100.Sh HISTORY 101The 102.Nm 103utility first appeared in 104.Bx 1 . 105It was rewritten for 106.Bx 4.3 Reno 107to improve speed and modernize style. 108The 109.Fl b 110and 111.Fl s 112options were added to 113.Nx 1.0 114for 115.St -p1003.2 116compliance. 117.Sh AUTHORS 118.An -nosplit 119.An Bill Joy 120wrote the original version of 121.Nm 122on June 28, 1977. 123.An Kevin Ruddy 124rewrote the command in 1990, and 125.An J. T. Conklin 126added the missing options in 1993. 127.Sh BUGS 128If underlining (see 129.Xr ul 1 ) 130is present it may be messed up by folding. 131