<s>
In	O
computing	O
,	O
a	O
named	O
pipe	B-Operating_System
(	O
also	O
known	O
as	O
a	O
FIFO	B-Operating_System
for	O
its	O
behavior	O
)	O
is	O
an	O
extension	O
to	O
the	O
traditional	O
pipe	B-Operating_System
concept	O
on	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
systems	I-Operating_System
,	O
and	O
is	O
one	O
of	O
the	O
methods	O
of	O
inter-process	B-Operating_System
communication	I-Operating_System
(	O
IPC	O
)	O
.	O
</s>
<s>
The	O
concept	O
is	O
also	O
found	O
in	O
OS/2	B-Application
and	O
Microsoft	B-Application
Windows	I-Application
,	O
although	O
the	O
semantics	O
differ	O
substantially	O
.	O
</s>
<s>
A	O
traditional	O
pipe	B-Operating_System
is	O
"	O
unnamed	B-Operating_System
"	O
and	O
lasts	O
only	O
as	O
long	O
as	O
the	O
process	O
.	O
</s>
<s>
A	O
named	O
pipe	B-Operating_System
,	O
however	O
,	O
can	O
last	O
as	O
long	O
as	O
the	O
system	O
is	O
up	O
,	O
beyond	O
the	O
life	O
of	O
the	O
process	O
.	O
</s>
<s>
Usually	O
a	O
named	O
pipe	B-Operating_System
appears	O
as	O
a	O
file	O
,	O
and	O
generally	O
processes	B-Operating_System
attach	O
to	O
it	O
for	O
IPC	O
.	O
</s>
<s>
Instead	O
of	O
a	O
conventional	O
,	O
unnamed	B-Operating_System
,	O
shell	O
pipeline	B-Operating_System
,	O
a	O
named	O
pipeline	B-Operating_System
makes	O
use	O
of	O
the	O
filesystem	B-Application
.	O
</s>
<s>
It	O
is	O
explicitly	O
created	O
using	O
mkfifo( )	O
or	O
mknod( )	O
,	O
and	O
two	O
separate	O
processes	B-Operating_System
can	O
access	O
the	O
pipe	B-Operating_System
by	O
name	O
one	O
process	O
can	O
open	O
it	O
as	O
a	O
reader	O
,	O
and	O
the	O
other	O
as	O
a	O
writer	O
.	O
</s>
<s>
For	O
example	O
,	O
one	O
can	O
create	O
a	O
pipe	B-Operating_System
and	O
set	O
up	O
gzip	B-Application
to	O
compress	O
things	O
piped	O
to	O
it	O
:	O
</s>
<s>
The	O
named	O
pipe	B-Operating_System
can	O
be	O
deleted	O
just	O
like	O
any	O
file	O
:	O
</s>
<s>
A	O
named	O
pipe	B-Operating_System
can	O
be	O
used	O
to	O
transfer	O
information	O
from	O
one	O
application	O
to	O
another	O
without	O
the	O
use	O
of	O
an	O
intermediate	O
temporary	O
file	O
.	O
</s>
<s>
For	O
example	O
,	O
you	O
can	O
pipe	B-Operating_System
the	O
output	O
of	O
gzip	B-Application
into	O
a	O
named	O
pipe	B-Operating_System
like	O
so	O
(	O
here	O
out.gz	O
is	O
from	O
above	O
example	O
but	O
it	O
can	O
be	O
any	O
gz	O
)	O
:	O
</s>
<s>
Then	O
load	O
the	O
uncompressed	O
data	O
into	O
a	O
MySQL	B-Application
table	O
like	O
so	O
:	O
</s>
<s>
Without	O
this	O
named	O
pipe	B-Operating_System
one	O
would	O
need	O
to	O
write	O
out	O
the	O
entire	O
uncompressed	O
version	O
of	O
file.gz	O
before	O
loading	O
it	O
into	O
MySQL	B-Application
.	O
</s>
<s>
Writing	O
the	O
temporary	O
file	O
is	O
both	O
time	O
consuming	O
and	O
results	O
in	O
more	O
I/O	B-General_Concept
and	O
less	O
free	O
space	O
on	O
the	O
hard	O
drive	O
.	O
</s>
<s>
PostgreSQL	B-Application
's	O
command	B-Application
line	I-Application
utility	O
,	O
psql	O
,	O
also	O
supports	O
loading	O
data	O
from	O
named	O
pipes	B-Operating_System
.	O
</s>
<s>
A	O
named	O
pipe	B-Operating_System
can	O
be	O
accessed	O
much	O
like	O
a	O
file	O
.	O
</s>
<s>
Win32	B-Library
SDK	O
functions	O
CreateFile	O
,	O
ReadFile	O
,	O
WriteFile	O
and	O
CloseHandle	O
open	O
,	O
read	O
from	O
,	O
write	O
to	O
,	O
and	O
close	O
a	O
pipe	B-Operating_System
,	O
respectively	O
.	O
</s>
<s>
Unlike	O
Unix	B-Application
,	O
there	O
is	O
no	O
command	B-Application
line	I-Application
interface	I-Application
,	O
except	O
for	O
PowerShell	B-Application
.	O
</s>
<s>
Named	O
pipes	B-Operating_System
cannot	O
be	O
created	O
as	O
files	O
within	O
a	O
normal	O
filesystem	B-Application
,	O
unlike	O
in	O
Unix	B-Application
.	O
</s>
<s>
Also	O
unlike	O
their	O
Unix	B-Application
counterparts	O
,	O
named	O
pipes	B-Operating_System
are	O
volatile	O
(	O
removed	O
after	O
the	O
last	O
reference	O
to	O
them	O
is	O
closed	O
)	O
.	O
</s>
<s>
Every	O
pipe	B-Operating_System
is	O
placed	O
in	O
the	O
root	O
directory	O
of	O
the	O
named	O
pipe	B-Operating_System
filesystem	B-Application
(	O
NPFS	O
)	O
,	O
mounted	O
under	O
the	O
special	O
path	O
\\.\pipe\	O
(	O
that	O
is	O
,	O
a	O
pipe	B-Operating_System
named	O
"	O
foo	O
"	O
would	O
have	O
a	O
full	O
path	O
name	O
of	O
\\.\pipe\foo	O
)	O
.	O
</s>
<s>
Anonymous	B-Operating_System
pipes	I-Operating_System
used	O
in	O
pipelining	O
are	O
actually	O
named	O
pipes	B-Operating_System
with	O
a	O
random	O
name	O
.	O
</s>
<s>
The	O
VMware	B-Operating_System
Workstation	I-Operating_System
PC	B-Device
hardware	O
virtualization	B-Architecture
tool	O
,	O
for	O
instance	O
,	O
can	O
expose	O
emulated	O
serial	B-Protocol
ports	I-Protocol
to	O
the	O
host	O
system	O
as	O
named	O
pipes	B-Operating_System
,	O
and	O
the	O
WinDbg	B-Application
kernel	O
mode	O
debugger	B-Application
from	O
Microsoft	O
supports	O
named	O
pipes	B-Operating_System
as	O
a	O
transport	O
for	O
debugging	O
sessions	O
(	O
in	O
fact	O
,	O
VMware	O
and	O
WinDbg	B-Application
can	O
be	O
coupled	O
together	O
–	O
as	O
WinDbg	B-Application
normally	O
requires	O
a	O
serial	O
connection	O
to	O
the	O
target	O
computer	O
–	O
letting	O
driver	B-Application
developers	B-Application
do	O
their	O
development	O
and	O
testing	O
on	O
a	O
single	O
computer	O
)	O
.	O
</s>
<s>
Both	O
programs	O
require	O
the	O
user	O
to	O
enter	O
names	O
in	O
the	O
\\.\pipe\name	O
form	O
.	O
</s>
<s>
Windows	O
NT	O
named	O
pipes	B-Operating_System
can	O
inherit	O
a	O
security	O
context	O
.	O
</s>
<s>
Summary	O
of	O
named	O
pipes	B-Operating_System
on	O
Microsoft	B-Application
Windows	I-Application
:	O
</s>
<s>
The	O
.NET	B-Application
Framework	I-Application
3.5	O
has	O
added	O
named	O
pipe	B-Operating_System
support	O
.	O
</s>
<s>
Named	O
pipes	B-Operating_System
can	O
also	O
be	O
used	O
as	O
an	O
endpoint	O
in	O
Microsoft	B-Application
SQL	I-Application
Server	I-Application
.	O
</s>
<s>
Named	O
pipes	B-Operating_System
are	O
also	O
a	O
networking	O
protocol	O
in	O
the	O
Server	B-Operating_System
Message	I-Operating_System
Block	I-Operating_System
(	O
SMB	O
)	O
suite	O
,	O
based	O
on	O
the	O
use	O
of	O
a	O
special	O
inter-process	B-Operating_System
communication	I-Operating_System
(	O
IPC	O
)	O
share	O
.	O
</s>
<s>
SMB	O
's	O
IPC	O
can	O
seamlessly	O
and	O
transparently	O
pass	O
the	O
authentication	O
context	O
of	O
the	O
user	O
across	O
to	O
Named	O
Pipes	B-Operating_System
.	O
</s>
<s>
Windows	O
NT	O
's	O
entire	O
NT	B-General_Concept
Domain	I-General_Concept
protocol	O
suite	O
of	O
services	O
are	O
implemented	O
as	O
DCE/RPC	B-General_Concept
service	O
over	O
Named	O
Pipes	B-Operating_System
,	O
as	O
are	O
the	O
Exchange	O
5.5	O
Administrative	O
applications	O
.	O
</s>
