Did you know that the device driver that implements named pipes is
actually a file system driver? In fact, the driver's name is NPFS.SYS,
for "Named Pipe File System". What you might also find surprising is
that its possible to obtain a directory listing of the named pipes
defined on a system. This fact is not documented, nor is it possible to
do this using the Win32 API. Directly using NtQueryDirectoryFile, the
native function that the Win32 FindFile APIs rely on, makes it possible
to list the pipes. The directory listing NPFS returns also indicates the
maximum number of pipe instances set for each pipe and the number of
active instances.
This learning path explains the purpose and use of the PowerShell pipeline and use the pipeline to sort, filter, enumerate and display output data for PowerShell cmdlets.