posixipc package is a "C" based extension that provides access to
POSIX message queues and shared memory through the Tcl channel mechanism.
Channel drivers are provided for message queue and shared memory. Commands are provided to open channels for either a message queue or shared memory object.
The package is presented as a literate program document which contains all the design information, code, and test cases. There is also man page documentation for the commands in the package.
A TEA compliant build mechanism is available as well a pre-compiled Tcl module. The precompiled module works with both Linux (glibc 2.28, Tcl 8.6) and FreeBSD (Release 12.0, Tcl 8.6). Note that MacOSX does not support POSIX message queues and the package code will not compile in that environment in its current state.