Return error numbers for all errors in errnames on this platform.
    
    The 'errno' module contains different global constants depending on
    the specific platform (OS). This function will return the list of
    numeric values for a given list of potential names.

def plat_specific_errors(*errnames):
    """Return error numbers for all errors in errnames on this platform.
    
    The 'errno' module contains different global constants depending on
    the specific platform (OS). This function will return the list of
    numeric values for a given list of potential names.
    """
    errno_names = dir(errno)
    nums = [getattr(errno, k) for k in errnames if k in errno_names]
    # de-dupe the list
    return dict.fromkeys(nums).keys()