Lisp_Object to char*

Lisp_Object to char*

[mr mike]

Hello emacs hackers,

In the C code, how do you convert a Lisp_Object to a char* value?

I'm asking because I'm playing around with making a gtk widget
from the gtk emacs port, and I am going to pass a argument
to make-frame like this

(make-frame '((foo . "abc")))

and I need to know what the value that goes with foo.

I can get the argument with x_get_arg().  I just need the value.

mike

Re: Lisp_Object to char*

[Eli Zaretskii]

> From: mr mike <mwingert7149@wowway.com>
> Date: Sat, 13 Dec 2003 14:25:48 -0500
> 
> In the C code, how do you convert a Lisp_Object to a char* value?
> 
> I'm asking because I'm playing around with making a gtk widget
> from the gtk emacs port, and I am going to pass a argument
> to make-frame like this
> 
> (make-frame '((foo . "abc")))
> 
> and I need to know what the value that goes with foo.
> 
> I can get the argument with x_get_arg().  I just need the value.

Is the XCDR macro what you want?

Re: Lisp_Object to char*

[Stefan Monnier]

> In the C code, how do you convert a Lisp_Object to a char* value?

You can use STRINGP to check that the Lisp_Object is indeed a string and
then XSTRING will get you a Lisp_String* pointer from which you can get the
size with SSIZE and the char* content with SDATA.


        Stefan