<s>
head	O
is	O
a	O
program	B-Application
on	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
used	O
to	O
display	O
the	O
beginning	O
of	O
a	O
text	O
file	B-Operating_System
or	O
piped	O
data	O
.	O
</s>
<s>
The	O
command	B-Application
syntax	B-Application
is	O
:	O
</s>
<s>
The	O
number	O
of	O
lines	O
printed	O
may	O
be	O
changed	O
with	O
a	O
command	B-Application
line	I-Application
option	O
.	O
</s>
<s>
GNU	B-Operating_System
head	O
allows	O
negative	O
arguments	O
for	O
the	O
-n	O
option	O
,	O
meaning	O
to	O
print	O
all	O
but	O
the	O
last	O
-	O
argument	O
value	O
counted	O
-	O
lines	O
of	O
each	O
input	O
file	B-Operating_System
.	O
</s>
<s>
Many	O
early	O
versions	O
of	O
Unix	B-Application
and	O
Plan	O
9	O
did	O
not	O
have	O
this	O
command	B-Application
,	O
and	O
documentation	O
and	O
books	O
used	O
sed	B-Application
instead	O
:	O
</s>
<s>
Equivalently	O
,	O
awk	B-Application
may	O
be	O
used	O
to	O
print	O
the	O
first	O
five	O
lines	O
in	O
a	O
file	B-Operating_System
:	O
</s>
<s>
Version	B-Operating_System
6	I-Operating_System
Unix	I-Operating_System
,	O
and	O
included	O
head	O
.	O
</s>
<s>
A	O
head	O
command	B-Application
is	O
also	O
part	O
of	O
ASCII	O
's	O
MSX-DOS2	O
Tools	O
for	O
MSX-DOS	B-Operating_System
version	O
2	O
.	O
</s>
<s>
The	O
command	B-Application
has	O
also	O
been	O
ported	O
to	O
the	O
IBM	B-Application
i	I-Application
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
