cl-sipc/README

cl-sipc (common lisp socket inter-process communication)

Unix domain socket message passing for Common Lisp.

Run `make' in this directory once to build the CFFI library.
Run `sudo make install' to install system-wide.

The symlinked libsipc.so will resolve after the ffi library is built and the package will work in this directory (the symlink is to libsipc/libsipc-ffi.so)
Additionally you can run `sudo make install' to make it work system-wide (installed to /usr/lib/libsipc.so) (`sudo make uninstall' to remove it)
Or you can copy/symlink libsipc/libsipc-ffi.so to wherever you need.

Additional tools can be built by running `make all-ffi' in the libsipc/ directory.

Functions:
 sipc:bind(file)	;; Bind to socket `file'. Returns the socket descriptor on success and nil on fail (the socket must not already exist)
 sipc:release(socket)	;; Close socket
 sipc:hook(socket error-callback message-callback)
   ;; start listening on `socket'. error-callback should be in format (lambda (error) ...). message-callback should be in format (lambda (type message )...).
   ;; available errors are:
	; :accept - There was an error accepting the connection
	; :read - There was an error reading the message
	; :closed - The connection was closed before a message could be read
	; :message - The message was invalid or outside the acceptable size bounds (TODO make this runtime instead of compile-time constant)
	;; (see libsipc/include/sipc.h for more details)
   ;; available types are:
	; :string - Normal string
	; :binary - CFFI pointer to memory (TODO currently unusable)
	; :close - A request to close (the message is always NIL for this type)
   ;; If an error or message callback returns NIL, the listener is stopped (you still have to call sipc:release()). Otherwise, the return is ignored.
 (sipc:with-bound-socket (socket-name socket-filename)
   body) ;; Bind socket from `socket-filename' to new lexical variable `socket-name' and run (progn @body), then relase the socket afterwards. If the socket fails to bind, return nil and do not attempt to execute body.

See `cl-sipc.lisp' for more documentation.

---

Example using sipcli (run `make all-ffi' in libsipc/ directory)
(see `test-server.lisp' for example server)

Terminal 1:
[user@host cl-sipc]$ ./test-server 
-> [+] listening on sipc.socket...

Terminal 2:
[user@host libsipc]$ ./sipcli -p ../sipc.socket "Hello World"

Terminal 1:
 <- (STRING) Hello World

Terminal 2:
[user@host libsipc]$ ./sipcli -cf ../sipc.socket

Terminal 1:
 <- (CLOSE) NIL
[-] listen rc 1
[user@host cl-sipc]$

---

TODO: Implement message sending wrapper.
TODO: Internal error handling.
TODO: Have libsipc built on system load
TODO: Change :binary message from pointer to vector (or at least pass size to handler so it's usable).
TODO: better .so loading