This extension provides a Tcl interface to the mmap(2) POSIX system
call.

It provides a Tcl package that allows Tcl scripts to:
1) Memory map files for improved access efficiency;
2) Share memory between related processes;
3) Easily implement cyclic persistent log files.

The functionality of 'mmap' is exported from this extension in the
form of a new Tcl channel type, named "mmap". A memory mapping is
established with the 'mmap' command. Following 'mmap' execution,
access to the memory mapped file is done via the standard Tcl
commands: puts/gets/seek/flush/close/fconfigure, only that this
time these commands operate on memory, rather than on a file.

WWW: http://tcl-mmap.sourceforge.net/