On Alpha and Integrity server systems, returns the displayable
    pathname for a given I/O channel or device name. Can be used to
    return all displayable paths to an I/O device.

    Format

      SYS$DEVICE_PATH_SCAN  [chan] [,devnam] ,itmlst [,contxt]

                            [,nullarg]

    C Prototype

      int sys$device_path_scan  (unsigned short int chan, void

                                *devnam, void *itmlst, unsigned int

                                *contxt, struct_generic_64 *nullarg);