🚀 go-pugleaf

Boris Epel wrote:
> 
> .h:
> typedef int32 (__CFUNC *DAQmxGetChanType_f) (TaskHandle taskHandle, 
> const char channel[], int32 *data);
> .c:
> HINSTANCE handle = LoadLibrary(_library);
> DAQmxGetChanType_f  DAQmxGetChanType = (DAQmxGetChanType_f) 
> GetProcAddress(handle, "DAQmxGetChanType");
> ...
> 

You are not checking whether handle returned by LoadLibrary is valid, 
nor if GetProcAddress succeeds.  I suspect that DAQmxGetChanType is 
getting set to NULL, so your call results in the AV you are seeing. 
It's possible that DAQmxGetChanType is not supported by all versions of 
the NIDAQmx API which is why it fails on some machines (Do you have the 
same version installed on all your machines?)

It's good programming practice to check the result of all system calls 
even though this is a pain, e.g.,

HINSTANCE handle = LoadLibrary(_library);
if (handle) {
   DAQmxGetChanType_f  DAQmxGetChanType =
    (DAQmxGetChanType_f)GetProcAddress(handle, "DAQmxGetChanType");
   if (DAQmxGetChanType == NULL)
     ShowMessage ("DAQmxGetChanType not found!");
} else {
	// check result of GetLastError
	// use FormatMessage to obtain human readable error info
}

-Eliot