Arguments

 

addr

   The starting address of the new region (must be the page
   boundary).
 

len

   The length, in bytes, of the new region.
 

prot

   Access permission, as defined in the <mman.h> header file.
   Specify either PROT_NONE, PROT_READ, or PROT_WRITE.
 

flags

   Attributes of the mapped region as the results of a bitwise-
   inclusive OR operation on any combination of the following:

   o  MAP_FILE or MAP_ANONYMOUS

   o  MAP_VARIABLE or MAP_FIXED

   o  MAP_SHARED or MAP_PRIVATE
 

filedes

   The file that you want to map to the new mapped file region
   returned by the open function.
 

off

   The offset, specified in bytes. The off_t data type is either a
   64-bit or 32-bit integer. The 64-bit interface allows for file
   sizes greater than 2 GB, and can be selected at compile time by
   defining the _LARGEFILE feature-test macro as follows:

   CC/DEFINE=_LARGEFILE
 

 . . .

   An optional integer specifying additional flags for the
   SYS$CRMPSC system service for MAP_SHARED. This optional argument
   (VSI C Extension) of the mmap function was introduced in
   OpenVMS Version 7.2.