<s>
fold	O
is	O
a	O
Unix	B-Application
command	I-Application
used	O
for	O
making	O
a	O
file	B-Operating_System
with	O
long	O
lines	O
more	O
readable	O
on	O
a	O
limited	O
width	O
computer	B-General_Concept
terminal	I-General_Concept
by	O
performing	O
a	O
line	B-Algorithm
wrap	I-Algorithm
.	O
</s>
<s>
Most	O
Unix	B-Application
terminals	O
have	O
a	O
default	O
screen	O
width	O
of	O
80	O
,	O
and	O
therefore	O
reading	O
files	O
with	O
long	O
lines	O
could	O
get	O
annoying	O
.	O
</s>
<s>
The	O
fold	O
command	B-Application
puts	O
a	O
line	O
feed	O
every	O
X	O
characters	O
if	O
it	O
does	O
not	O
reach	O
a	O
new	O
line	O
before	O
that	O
point	O
.	O
</s>
<s>
If	O
the	O
-w	O
argument	O
is	O
set	O
,	O
the	O
fold	O
command	B-Application
allows	O
the	O
user	O
to	O
set	O
the	O
maximum	O
length	O
of	O
a	O
line	O
.	O
</s>
<s>
It	O
was	O
inherited	O
into	O
the	O
first	O
version	O
of	O
POSIX.1	O
and	O
the	O
Single	O
Unix	B-Application
Specification	O
.	O
</s>
<s>
It	O
first	O
appeared	O
in	O
1BSD	B-Operating_System
of	O
1977	O
.	O
</s>
<s>
The	O
version	O
of	O
fold	O
bundled	O
in	O
GNU	B-Application
coreutils	I-Application
was	O
written	O
by	O
David	O
MacKenzie	O
.	O
</s>
<s>
The	O
command	B-Application
is	O
available	O
as	O
a	O
separate	O
package	O
for	O
Microsoft	B-Application
Windows	I-Application
as	O
part	O
of	O
the	O
UnxUtils	B-Application
collection	O
of	O
native	B-Language
Win32	B-Library
ports	O
of	O
common	O
GNU	B-Operating_System
Unix-like	B-Operating_System
utilities	O
.	O
</s>
<s>
As	O
a	O
usage	O
example	O
,	O
to	O
fold	O
a	O
file	B-Operating_System
named	O
file.txt	O
to	O
have	O
a	O
maximum	O
of	O
50	O
characters	O
per	O
line	O
,	O
one	O
could	O
run	O
the	O
following	O
command	B-Application
:	O
</s>
<s>
file.txt	O
:	O
</s>
