SYNOPSIS
#include <sys/mman.h>
#ifdef _POSIX_MAPPED_FILES
void * mmap(void *start, size_t length, int prot , int
flags, int fd, off_t offset);
int munmap(void *start, size_t length);
#endif
DESCRIPTION
The mmap function asks to map length bytes starting at
offset offset from the file (or other object) specified by
the file descriptor fd into memory, preferably at address
start. This latter address is a hint only, and is usually
specified as 0. The actual place where the object is
mapped is returned by mmap, and is never 0.