The IOCTL_PAR_QUERY_LOCATION request returns the "LPTn" or "LPTn.m" symbolic link name associated with a parallel device. This request is only supported by Windows XP and later.

For more information, see Device Stacks for ParallelPorts and Devices and Parallel Device Interfaces, Internal Names, and Symbolic Links.

Major code


Input buffer

The client sets the AssociatedIrp.SystemBuffer member to a pointer to a character buffer for the location information.

Input buffer length

The length of the character buffer.

Output buffer

The parallel port bus driver outputs the location information in the buffer pointed to by AssociatedIrp.SystemBuffer as a NULL-terminated character string.

Output buffer length

The client sets the Parameters.DeviceIoControl.OutputBufferLength member to the length of the output buffer that the system-supplied bus driver for parallel ports uses to output the device location information.

Status block

If the request succeeds, the Information member is set to the length, in bytes, of the symbolic link name plus the NULL terminator. Otherwise, Information is set to zero.

The Status member is set to one of the generic status values returned by device control requests for parallel devices or to the following value:


The Parameters.DeviceIoControl.OutputBufferLength member is less than size, in bytes, of the location information and the NULL terminator.


Requirement Value
Header ntddpar.h (include Ntddpar.h)

See also