Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
Published: September 10, 2026
Download PipeList (295 KB)
Introduction
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.
Download PipeList (295 KB)
Runs on:
- Client: Windows 11 and higher
- Server: Windows Server 2019 and higher
- Nano Server: 2019 and higher