Passing integer pointer in XS?

[martin67]

Hi, I've started to use XS for interfacing an existing C library. It works so far until I come to passing integer pointers. I could really use some help here... The C function is defined as

int WINAPI tdSensor(
  char *  protocol,
  int     protocolLen,
  char *  model,
  int     modelLen,
  int *   id,
  int *   dataTypes 
)        

Use this function to iterate over all sensors. Iterate until TELLSTICK
+_SUCCESS is not returned.

Parameters:
[out]    protocol    A by ref string where the protocol of the sensor 
+will be placed.
[in]    protocolLen    The length of the protocol parameter.
[out]    model    A by ref string where the model of the sensor will b
+e placed.
[in]    modelLen    The length of the model parameter.
[out]    id    A by ref int where the id of the sensor will be placed.
[out]    dataTypes    A by ref int with flags for the supported sensor
+ values.
Returns:
TELLSTICK_SUCCESS if there is more sensors to be fetched.

My definition in the XS file look like this:

int
tdSensor(protocol, protocolLen, model, modelLen, id, dataTypes)
        char *  protocol
        int     protocolLen
        char *  model
        int     modelLen
        int *   id
        int *   dataTypes

I had to add a definition in my typedef file:

TYPEMAP
int *           T_PTR

But this doesn't work as I think it should. I've tried with T_PV and T_PTRREF but no luck. When I call the code from my test program it looks like this:

my $protocol = "aaaaaaaaaaaaaaaaaaaaaaaaa";
my $model = "bbbbbbbbbbbbbbbbbbbbbbbbb";
my $sensorId = 1;
my $dataTypes = 2;

while (TellStick::tdSensor($protocol, 25, $model, 25, $sensorId, $data
+Types) == TELLSTICK_SUCCESS) {

  print "res: $res, protocol: $protocol, model: $model, sensorId: $sen
+sorId, dataTypes: $dataTypes\n";
}

I'm not really sure how I should call the function from Perl. Trial and error gave me that I needed to set a value on the strings (protocl & model) before calling tdSensor. But this does not seem to work for the integer pointers. Or should I call them like '\$sensorID' instead?

It seems like it should be pretty trivial to pass a integer pointer so I hope to get some wisdom on how to do this from the Monks...