mmap
The {Unix} {system call} which establishes a mapping between a
range of addresses in a user process's address space and a
portion of some "memory object" (typically a file, one of the
special "devices" /dev/mem or /dev/kmem or some
{memory-mapped} peripheral). This allows the process to
access a file at random byte offsets without using the seek
{system call} or to access physical addresses or {kernel}'s
{virtual address} space. It can also be used as an
alternative to writing a {device driver} since it is usually
simpler to code and faster to use.
(1995-02-14)