mmap

The synopsis is

void *mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t off);

It shall establish a mapping between a process' address space and a file, shared memory object, or typed memory object. The format of the call is as follows:

pa=mmap(addr, len, prot, flags, fildes, off);

The mmap() function establishes a mapping between the address space of the process at an address pa for len bytes to the memory object represented by the file descriptor fildes at offset off for len bytes.

The parameter prot determines whether read, write, execute, or some combination of accesses are permitted to the data being mapped.