OpenEuphoria

Re: What is the equivalent EU expression

• Posted by Mark Brown <mabrown at SENET.COM.AU> Mar 16, 2000
• 451 views

Hi Brian

One small thing with your example for prasanta. I seem to remember that
inputs to C functions must all be atoms so I think the "integer arg1" might
need to be "atom arg1". I seem to remember getting an error something like
"inputs to C functions must be atoms" once before.

If I'm wrong please ignore

Mark



----- Original Message -----
From: Brian Jackson <bjackson at 2FARGON.COM>
To: <EUPHORIA at LISTSERV.MUOHIO.EDU>
Sent: Thursday, March 16, 2000 1:33
Subject: Re: What is the equivalent EU expression


> On Wed, 15 Mar 2000 21:51:30 -0500, Prasanta Chakraborty
> <prasanta at WRITEME.COM> wrote:
>
> >Hi,
> >
> >I am trying to call a C func from EU, the C Func is described as:
> >SQLAllocHandle(SQLSMALLINT HandleType, SQLINTEGER InputHandle, SQLINTEGER
> >FAR *OutputHandle);
> >where SQLINTEGER is of type long.
> >
> >What will be the equivalent EU code.
> >
> >Regards,
> >Prasanta.
>
> Prasanta,
>
> What you ask is actually a 2-part process.  First you must define the c
> function (and the DLL it lives in) in the context of your program using
> open_dll() and define_c_func().  Here's an example:
>
> global constant wsock32 = open_dll("wsock32.dll")
> global constant func_WSAStartup = define_c_func(wsock32,"WSAStartup",
>     {C_SHORT,C_POINTER},C_INT)
>
> This "links" the DLL to your program, and declares func_WSAStartup as an
> external C function that takes C types SHORT(euphoria integer) and POINTER
> (euphoria atom) as arguments, and returns a type INT(euphoria atom).
>
> Now to use the function, you would need to do this:
>
> integer arg1
> atom arg2
> atom returnValue
>
> -- you need to assign the appropriate values to arg1 and arg2 here
> returnValue = c_func(func_WSAStartup, {arg1, arg2})
>
> Also, Fabio Ramirez has written a very nice MySQL interface for Euphoria
> which may either be exactly what you need, or at least give you some good
> examples of how to wrap SQL API functions using Euphoria.
>
> Hope this helps!
>
> Brian