xref: /freebsd/usr.bin/fold/fold.1 (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)

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.Dd October 29, 2020
.Dt FOLD 1
.Os
.Sh NAME
.Nm fold
.Nd "fold long lines for finite width output device"
.Sh SYNOPSIS
.Nm
.Op Fl bs
.Op Fl w Ar width
.Op Ar
.Sh DESCRIPTION
The
.Nm
utility is a filter which folds the contents of the specified files,
or the standard input if no files are specified,
breaking the lines to have a maximum of 80 columns.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl b
Count
.Ar width
in bytes rather than column positions.
.It Fl s
Fold line after the last blank character within the first
.Ar width
column positions (or bytes).
.It Fl w Ar width
Specify a line width to use instead of the default 80 columns.
The
.Ar width
value
should be a multiple of 8 if tabs are present, or the tabs should
be expanded using
.Xr expand 1
before using
.Nm .
.El
.Sh ENVIRONMENT
The
.Ev LANG , LC_ALL
and
.Ev LC_CTYPE
environment variables affect the execution of
.Nm
as described in
.Xr environ 7 .
.Sh EXAMPLES
Fold text in standard input with a width of 20 columns:
.Bd -literal -offset indent
$ echo "I am smart enough to know that I am dumb" | fold -w 15
I am smart enou
gh to know that
 I am dumb
.Ed
.Pp
Same as above but breaking lines after the last blank character:
.Bd -literal -offset indent
$ echo "I am smart enough to know that I am dumb" | fold -s -w 15
I am smart
enough to know
that I am dumb
.Ed
.Sh SEE ALSO
.Xr expand 1 ,
.Xr fmt 1
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.1-2001 .
.Sh HISTORY
The
.Nm
utility first appeared in
.Bx 1 .
It was rewritten for
.Bx 4.3 Reno
to improve speed and modernize style.
The
.Fl b
and
.Fl s
options were added to
.Nx 1.0
for
.St -p1003.2
compliance.
.Sh AUTHORS
.An -nosplit
.An Bill Joy
wrote the original version of
.Nm
on June 28, 1977.
.An Kevin Ruddy
rewrote the command in 1990, and
.An J. T. Conklin
added the missing options in 1993.
.Sh BUGS
If underlining (see
.Xr ul 1 )
is present it may be messed up by folding.