Feature #3731: Easier Embedding API for Ruby

• Status: Assigned
• Assignee: ko1 (Koichi Sasada)
• Target version: -

[Beoran (Beoran Aegul)]

=begin
With Ruby 1.9, it has become more difficult to embed Ruby in a C application correctly.
It would be nice if there was a clearly documented and simple C API to embed ruby in C programs.
I know Ruby was not designed from the start to be embedded, but Ruby was used before in several
products as an embedded scripting langauge. It should therefore be possible to do so in a
more straightforward way.

Kind Regards,

B.
=end

[asher (Asher Haig)]

What is difficult about this?

Example:

#include <ruby.h>

int main( int argc __attribute__((unused)), char *argv[] __attribute__((unused)) )	{
	
	ruby_init();
	
	//	Ruby Options are just like /usr/bin/ruby
	//	interpreter name, script name, argv ...
	char*	options[]	=	{ "", "rpdom_test.rb",  };
	void*	node		=	ruby_options( 2, options );
	
	return ruby_run_node( node );
}	

Struck me as potentially a documentation issue, but the actual functionality I think is pretty straightforward?

Asher

[Beoran (Beoran Aegul)]

Dear Asher,

Well, I certainly agree documentation should be improved for this use case! :)

However, the problem with what you suggest is that it doesn't work more than once.

For example; I get a segmentation violation (crash) with a "You may encounter a bug of Ruby interpreter."
on the second call to ruby_run_node();
if I try this on a ruby1.9.1 p0:

#include <ruby.h>

RUBY_GLOBAL_SETUP
int main( int argc __attribute__((unused)), char *argv[] __attribute__((unused)) )	{
    RUBY_INIT_STACK 
    ruby_init();	
    {
        char*	options[]	=	{ "", "-e", "puts 'hello'"  };
        void*	node		=	ruby_options( 2, options );
        char*	options2[]	=	{ "", "-e", "puts 'world'"  };
        void*	node2		=	ruby_options( 2, options2 );	
        ruby_run_node( node  );
        ruby_run_node( node2 );
    }
}	

It may be that this bug is fixed in later versions, but I still have to install them to try.

Another problem is that it's a rather unwieldy API. It's nicer if you can run multiple scripts, or call rb_eval_string multiple times.
It's also nice if you can catch syntax errors in the ruby files loaded and handle them on the C side.

Kind Regards,

B.

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Feedback

[nahi (Hiroshi Nakamura)]

• Description updated (diff)
• Category set to core
• Status changed from Feedback to Open
• Assignee set to ko1 (Koichi Sasada)
• Target version set to 2.0.0

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Assigned

[ko1 (Koichi Sasada)]

I'll write document for embedding Ruby on your application.
At first, in Japanese,
Second, translate in English.
Please revise it after I finished.

[ko1 (Koichi Sasada)]

• Priority changed from Normal to 5

Ah, sorry for pending.
I need one more body (brain?) of myself.

[mame (Yusuke Endoh)]

• Target version changed from 2.0.0 to 2.6

ko1, I think you are not divided yet.

This looks a big feature. I'm setting this to next minor.
Please try it if you have time after you finished other tasks.

--
Yusuke Endoh [e-mail]

[naruse (Yui NARUSE)]

• Target version deleted (2.6)

[matheusrich (Matheus Richard)]

@mame (Yusuke Endoh) @ko1 (Koichi Sasada), is this still needed given that we have mruby?