Editing Named pipe (section)

== In Windows ==

A named pipe can be accessed much like a file. [[Windows API|Win32]] SDK functions <code>CreateFile</code>, <code>ReadFile</code>, <code>WriteFile</code> and <code>CloseHandle</code> open, read from, write to, and close a pipe, respectively. Unlike Unix, there is no [[command line interface]], except for [[PowerShell]].

Named pipes cannot be created as files within a normal filesystem, unlike in Unix. Also unlike their Unix counterparts, named pipes are volatile (removed after the last reference to them is closed). Every pipe is placed in the root directory of the named pipe filesystem (NPFS), mounted under the special path <code>\\.\pipe\</code> (that is, a pipe named "[[foo]]" would have a full path name of <code>\\.\pipe\foo</code>). Anonymous pipes used in pipelining are actually named pipes with a random name.

They are very rarely seen by users, but there are notable exceptions. The [[VMware Workstation]] [[Personal Computer|PC]] hardware [[virtual machine|virtualization]] tool, for instance, can expose emulated [[serial port]]s to the host system as named pipes, and the [[WinDbg]] kernel mode [[debugger]] from [[Microsoft]] supports named pipes as a transport for debugging sessions (in fact, VMware and WinDbg can be coupled together – as WinDbg normally requires a serial connection to the target computer – letting [[device driver|driver]] [[Software developer|developers]] do their development and testing on a single computer). Both programs require the user to enter names in the <code>\\.\pipe\''name''</code> form.

Windows NT named pipes can inherit a security context.

Summary of named pipes on Microsoft Windows:
* Intermachine and intramachine IPC
* [[Duplex (telecommunications)#Half duplex|Half-duplex]] or [[Duplex (telecommunications)#Full duplex|full-duplex]]
* [[Byte-oriented]] or [[packet-oriented]]
* [[Reliability (computer networking)|Reliable]]
* [[Connection-oriented communication]]
* Blocking or Nonblocking read and write (choosable)
* Standard device I/O handles (<code>ReadFile</code>, <code>WriteFile</code>)
* [[Namespace]] used to create handles
* Inefficient WAN traffic (explicit data transfer request, unlike e.g. TCP/IP sliding window, etc.)
* Peekable reads (read without removing from pipe's input buffer)

The [[.NET Framework]] 3.5 has added named pipe support.<ref>{{cite web |url=https://docs.microsoft.com/en-us/dotnet/api/system.io.pipes |title=System.IO.Pipes Namespace |publisher=[[Microsoft Developer Network]]}}</ref>

Named pipes can also be used as an endpoint in [[Microsoft SQL Server]].<ref>{{cite web
| url=https://support.microsoft.com/en-us/help/265808/how-to-connect-to-sql-server-by-using-an-earlier-version-of-sql-server
| title=How to connect to SQL Server by using an earlier version of SQL Server
| date=2019-11-19
| publisher=[[Microsoft]]
| access-date=2020-05-19
| archive-date=2020-07-20
| archive-url=https://web.archive.org/web/20200720014704/https://support.microsoft.com/en-us/help/265808/how-to-connect-to-sql-server-by-using-an-earlier-version-of-sql-server
| url-status=live
}}</ref>

Named pipes are also a networking protocol in the [[Server Message Block]] (SMB) suite, based on the use of a special [[inter-process communication]] (IPC) share. SMB's IPC can seamlessly and transparently pass the authentication context of the user across to Named Pipes. Windows NT's entire [[NT Domain]] protocol suite of services are implemented as [[DCE/RPC]] service over Named Pipes, as are the Exchange 5.5 Administrative applications.