HP C/iX Library Reference Manual (30026-90004)

Chapter 3 25
Interfacing with MPE/iX
MPE/iX File Numbers
MPE/iX File Numbers
The values returned by HP C/iX library functions such as fopen and open do not represent
values that are meaningful to the MPE/iX file system intrinsics. The function
_mpe_fileno, declared in mpe.h, maps a file descriptor returned by a C library function
such as open into an MPE/iX file number that can be passed directly to MPE/iX file system
intrinsics. If fd is a file descriptor returned by the C library function open,
_mpe_fileno(fd) returns the associated MPE/iX file number. For a description of
_mpe_fileno, see chapter 5.
The _mpe_fileno function is not supported in the POSIX/iX library. However, equivalent
functionality is provided by the _MPE_FILENO macro. The _MPE_FILENO macro is described
in the MPE/iX Developer's Kit Reference Manual.