Call Library Function

[thenoob94]

I have the following c function:

extern "C"{

int getInterfaces( uint32_t numInterface, void* g_hSystem);
    
}

int getInterfaces( uint32_t numInterface, void* g_hSystem)
{
    //Get Interface
    bool bChanged = false;

    SV_RETURN ret = SVSystemUpdateInterfaceList(g_hSystem, &bChanged, 1000);
    if (SV_ERROR_SUCCESS != ret)
    {
        printf("%s SVSystemUpdateInterfaceList failed!:%d\n", __FUNCTION__, ret);
        return -1;
    }

    ret = SVSystemGetNumInterfaces(g_hSystem, &numInterface);
    if (SV_ERROR_SUCCESS != ret)
    {
        printf("%s SVSystemGetNumInterfaces failed!:%d\n", __FUNCTION__, ret);
        return -1;
    }

    if (0 == numInterface)
    {
        printf("%s No Interface Available!\n", __FUNCTION__);
        return -1;
    }
}

 

How would I create "void* g_hSystem" in Labview?

 

 

 

 

 

[Zou]

You need the .h file which defines g_hSystem.

 

 

[Rolf Kalbermatter]

It misses context. void means NOTHING, and void * means a pointer to whatever the C programmer may have decided. Problem is that if the caller and callee don't agree what that anything means, really BAD things will happen. But without some more information all I can say is that it is a pointer and that would be in the LabVIEW Call Library Node a pointer sized integer. If that could work in this context is at least questionably. There obviously would need to be some other function that can return such a "handle"to you. The functions as you show them only consume this handle and can't create it in a meaningful way.