Reads from a binary file.
fd - the file descriptor
num - the maximum number of items to read
type - the type of items to read (
data - the buffer
count - the number of items read, optional
If count is not provided and the number of items read is less than the maximum number of items to read, then this routine errors.
PetscBinaryRead() uses byte swapping to work on all machines; the files
are written to file ALWAYS using big-endian ordering. On little-endian machines the numbers
are converted to the little-endian format when they are read in from the file.
When PETSc is ./configure with –with-64-bit-indices the integers are written to the
file as 64 bit integers, this means they can only be read back in when the option –with-64-bit-indices