[MBysPy] Add a function to read string from C adress that handles NULL adress.

MBsysC/mbs_interface/MBsysPy/mbs_utilities.py

@@ -7,11 +7,11 @@ Summary
 Defines the functions that are not specific to a MBS analysis.
 Modify the C libraries to get a python compatible behavior.
 """
-# MBsysC version : 1.13.0
 # Author : Robotran Team
 # (c) Universite catholique de Louvain, 2019
 
 from __future__ import print_function
+import ctypes
 import numpy as np
 
 # importing libraries
@@ -72,6 +72,31 @@ def str_to_bytes(message):
     return message
 
 
+def str_from_c_pointer(address, default_name=None):
+    """Read the string at the provided address.
+
+    If the address is 'NULL' ('None' in Python), the default name is returned.
+
+    Parameters
+    ----------
+    address : int
+        Value of the address.
+    default_name : str, optional
+        The default name to return if the adress is invalid (None).
+        The default is None.
+
+    Returns
+    -------
+    str
+        The string at the address, or the default name.
+
+    """
+    if address is not None:
+        return bytes_to_str(ctypes.string_at(address))
+    else:
+        return str(default_name)
+
+
 def set_output(value, label):
     """Save a value during time integration.