OpenEuphoria

Re: How to catch integer 64 bit return variable type

• Posted by Juergen Luethje <j.lue at gmx.de> Jun 08, 2007
• 731 views

D. Darmawan wrote:

> Dear all,
> 
> I'm building a small application using sqlite3 API. The application run 
> smoothly until an integer field consists a value greater than 32 bit 
> integer was found on database. Particularly, sqlite3 API has some 
> functions with 64 bit integer return value (long long int variable 
> type), but it can't be catch properly in Euphoria since library dll.e 
> does not provide any constant variable for handling 64 bit integer 
> return value at all. Trying one of both C_FLOAT and C_DOUBLE only return 
> a 'nan' value.
> 
> Any information, suggestion or an idea to solve this problem?

You need functions like these:

global function peek8u (atom addr)
   -- returns an *unsigned* 8-byte integer
   return peek4u(addr+4)*#100000000 + peek4u(addr)
end function

global function peek8s (atom addr)
   -- returns a *signed* 8-byte integer
   atom ret

   ret = peek4u(addr+4)*#100000000 + peek4u(addr)
   if ret > #7FFFFFFFFFFFFFFF then
      ret -= #10000000000000000
   end if
   return ret
end function

-- Then in your program use code such as:

myAPIfunc = define_c_func(myDLL, "desired_function", {C_POINTER, C_POINTER},
C_LONG)

lpMyVar1 = allocate(8)
lpMyVar2 = allocate(8)

x = c_func(myAPIfunc, {lpMyVar1, lpMyVar2})

myVar1 = peek8u(lpMyVar1)
myVar2 = peek8s(lpMyVar2)

free(lpMyVar1)
free(lpMyVar2)

Regards,
   Juergen