<s>
pr	B-Application
is	O
a	O
command	B-Application
on	O
various	O
operating	B-General_Concept
systems	I-General_Concept
that	O
is	O
used	O
to	O
paginate	O
or	O
columnate	O
computer	B-Operating_System
files	I-Operating_System
for	O
printing	O
.	O
</s>
<s>
It	O
can	O
also	O
be	O
used	O
to	O
compare	O
two	O
files	O
side	O
by	O
side	O
,	O
as	O
an	O
alternative	O
to	O
diff	B-Application
.	O
</s>
<s>
It	O
is	O
a	O
required	O
program	O
in	O
a	O
POSIX-compliant	O
environment	O
and	O
has	O
been	O
implemented	O
by	O
GNU	B-Operating_System
as	O
part	O
of	O
the	O
GNU	B-Application
Core	I-Application
Utilities	I-Application
.	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>
It	O
is	O
also	O
available	O
in	O
the	O
OS-9	B-Operating_System
shell	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>
