Re: Interactive interpreter in embedded application

On 01/19/2014 11:46 AM, alu wrote:
> I have a C++ program that uses SWI-Prolog as a logic server via PlEngine. Now
> I'm wondering if it is possible to write a function, which behaves like the
> interactive interpreter command line. 
> 
> This function would receive a string (command line input) and return a
> string (command line output as a response to input). 
> *int PlCall(const char *goal)* seems to do the trick (input-wise), but I
> need something for the output.

You need to rebind the I/O streams and start a thread.  This is done in
src/pl-ntmain.c for the swipl-win.exe console on Windows.  If Qt is an
option
for you, Carlo Capelli has great stuff for you.

> This way it would be possible to have the interpreter in a GUI program (e.g.
> as a dock widget). Would be great for debugging and manipulation of an
> otherwise integrated Prolog system. 

Another alternative is to do

	PlCall("prolog_server(4000, [])");

that creates a telnet server on port 4000.  Then do

	% telnet localhost 4000
	Trying 127.0.0.1...
	Connected to localhost.
	Escape character is '^]'.
	Welcome to the SWI-Prolog server on thread client@localhost

	1 ?-

Be careful about your security!  I.e., only run this in a properly secured
environment.

	Enjoy --- Jan