i made the following code to try to figure out how api calls are made in windows from D, but no matter what i try the type checking wont allow me to call it. the Docs sugest that you can use the .append(0) to add a null at the end of a string, but it wouldnt let me do that either... either way could anyone give me some tips on which direction to go with this code...

import std.c.stdio;

extern (Windows): private void *GetComputerName(uint *lpBuffer,uint nSize);

int main( char [] [] args ) {

	char[] newname = new char[254];
	 newname =  newname ~ "\n";

  if  (GetComputerName((uint) *newname, (uint)255))
    {
        printf("%s\n",newname);
   }

	return 1;
}


thanks for any help

Try the following version:

import std.c.stdio;

extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);

int main( char [] [] args ) {

char[] newname = new char[255];

   if  (GetComputerNameA(newname, newname.length))
     {
         printf("%.*s\n",newname);
    }

return 1;
}

Walter wrote:

> Try the following version:
> 
> import std.c.stdio;
> 
> extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
> 
> int main( char [] [] args ) {
> 
> char[] newname = new char[255];
> 
>    if  (GetComputerNameA(newname, newname.length))
>      {
>          printf("%.*s\n",newname);
>     }
> 
> return 1;
> }
> 
> 

thanks walter, you've saved me from running screaming back to vb :)
Once i can get a feel for the syntax more, and how things work i think ill be ok... ive programmed for years, just not in this type of language.

"Lewis" <dethbomb@hotmail.com> wrote in message news:brds73$1g41$1@digitaldaemon.com...
> thanks walter, you've saved me from running screaming back to vb :)
> Once i can get a feel for the syntax more, and how things work i think
> ill be ok... ive programmed for years, just not in this type of language.

It's a big change going from an untyped language to a typed one. Good luck!

extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);

int main( char [] [] args ) {
char[] newname = new char[255];
   if  (GetComputerNameA(newname, newname.length))
     {
         printf("%.*s\n",newname);
     }
return 1;
}

well unfortunatly that code gives an memory access error, but i have
managed to get it to run, but i get the following error...
Error 42: Symbol Undefined _GetComputerNameA@12
--- errorlevel 1

does that mean it couldnt find the function address in the dll?

after 12 hours of trying to get D to print my computer name out, im certain i have a long road ahead :) however, im persistent an stubborn ;o)

however, im persistent an stubborn ;o)
"Lewis" <dethbomb@hotmail.com> wrote in message
news:breiub$7a2$2@digitaldaemon.com...
>
> extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
>
> int main( char [] [] args ) {
> char[] newname = new char[255];
>     if  (GetComputerNameA(newname, newname.length))
>       {
>           printf("%.*s\n",newname);
>       }
> return 1;
> }
>
> well unfortunatly that code gives an memory access error, but i have
> managed to get it to run, but i get the following error...
> Error 42: Symbol Undefined _GetComputerNameA@12
> --- errorlevel 1
>
> does that mean it couldnt find the function address in the dll?
>
> after 12 hours of trying to get D to print my computer name out, im certain i have a long road ahead :) however, im persistent an stubborn ;o)

> however, im persistent an stubborn ;o)

Thats what it takes!

There is a very good win32 wrapper at http://hp.vector.co.jp/authors/VA028375/contents/D_windows.h.html

Also you will need to link against a 'stub' library , GetComputerName is kernel.lib, link against it ( just specfiy its name on the command line, dmd foo.d kernel.lib )

Welcome to D !

C


"Lewis" <dethbomb@hotmail.com> wrote in message news:breiub$7a2$2@digitaldaemon.com...
>
> extern (Windows): int GetComputerNameA(char *lpBuffer,uint nSize);
>
> int main( char [] [] args ) {
> char[] newname = new char[255];
>     if  (GetComputerNameA(newname, newname.length))
>       {
>           printf("%.*s\n",newname);
>       }
> return 1;
> }
>
> well unfortunatly that code gives an memory access error, but i have
> managed to get it to run, but i get the following error...
> Error 42: Symbol Undefined _GetComputerNameA@12
> --- errorlevel 1
>
> does that mean it couldnt find the function address in the dll?
>
> after 12 hours of trying to get D to print my computer name out, im certain i have a long road ahead :) however, im persistent an stubborn ;o)

"Lewis" <dethbomb@hotmail.com> wrote in message news:breiub$7a2$2@digitaldaemon.com...
> well unfortunatly that code gives an memory access error, but i have

Oops, had the second parameter declaration wrong.

extern (Windows): int GetComputerNameA(char *lpBuffer,uint* nSize);

int main( char [] [] args )
{
    char[] newname = new char[255];
    uint length;
    length = newname.length;
    if  (GetComputerNameA(newname, &length))
      {
          printf("%.*s\n",newname[0 .. length]);
      }
    return 1;
}



> managed to get it to run, but i get the following error... Error 42: Symbol Undefined _GetComputerNameA@12
> --- errorlevel 1
> does that mean it couldnt find the function address in the dll?

The linker doesn't look at dll's. It looks at .lib files. To see which lib a name is in, grep the .lib file for the name. For example, GetComputerNameA is in \dm\lib\kernel32.lib. Make sure you're linking that in.

ok, somebody stop me when i get way out in left field :)
All these linker, header, libs an stuff is cause for a headache to a vb programmer :( ... but it slowly starting to making sense.

My assumption at the moment is that the .lib files are (somewhat) analagous to vb's typelib files in that they give the compiler a template to call the dll with? header files are all to define datatypes and function templates, so that the compiler can do compile time type checking...?

right now im attempting to see if a theory i have (that libs create a static link to a dll as opposed to a dynamic link) that i can define several dll calls once to dynamicly load a library and then store function pointers in public variables to the address's of the functions in the dll, by calling (psuedo example) "LoadLibrary("DllName")" *if not loaded already* and Address = LoadFunctionAddress("FunctionName")

now my question is, can i store these function address's in a delegate or what would be the best way? and also what are the advantages of dynamic loading (and linking) with windows dll's over static linking with "libs"?

WoW... it worked!! Now i only have to link to two library's and i can call
 any dll function :) I have pasted my code below for critique if someone
 has any suggestions on how to make it better... I have code my first D
 program without help :) as mickeyD's would say "Im Loving It!!"


 import std.c.stdio;

 extern (Windows): int LoadLibraryA (char *lpLibFileName);
 extern (Windows):int CallWindowProcA(int  lpPrevWndProc,int hWnd,char*
 Msg,char* wParam,int lParam);
 extern (Windows): int GetProcAddress(int hModule,char *lpProcName);
 extern (Windows):int GetModuleHandleA(char *lpModuleName);

 int main( char [] [] args ) {

     auto char[] Msg = "You Have Dynamically Loaded This MessageBox!!";
     auto char[] Title = "Cool Message Box Title";
     auto char[] LibraryName = "user32";
     auto char[] FunctionName = "MessageBoxA";
     auto int FunctionAddress;
     auto int Success;

   try {

    FunctionAddress = DynamicLoad(LibraryName,FunctionName);

   if ( FunctionAddress != 0 ) {
     Success = CallWindowProcA(FunctionAddress,0,Msg,Title,0);
   }
 }
 catch (Object e) {
     printf("%s\n",e.toString);
      }

     return 0;
 }


 int DynamicLoad(char[] LibName,char[] FuncName) {

     auto int hLib;
     int hProc;

     hLib = GetModuleHandleA(LibName);

     if ( hLib == 0 )     {
          hLib = LoadLibraryA(LibName);
     }

     if ( hLib == 0)     {
          return 0;
     }
     else      {
            hProc = GetProcAddress(hLib, FuncName);
       }

     return hProc;
  }