linux: add start script and fixes; diagnostic outputs

app/ipm/simple_refrig_api.py

@@ -144,13 +144,12 @@ class Refifc(object):
                 os.chdir(self.original_directory)
                 raise
 
-        ctypes_refrig_name = refrig_name
-        if os.name == 'posix':
-            if not ctypes_refrig_name.lower().endswith("so"):
-                ctypes_refrig_name = ctypes_refrig_name + ".so"
-            if not ctypes_refrig_name.lower().startswith("lib"):
-                ctypes_refrig_name = "lib" + ctypes_refrig_name
-
+        # Use the plain refrigerant identifier when calling the native loader.
+        # On POSIX the native library usually resolves the actual "libRxxx.so"
+        # filename itself and expects a simple name like "R134a". Passing a
+        # modified filename (e.g. "libR134a.so") can confuse the native loader
+        # and lead to crashes. Also ensure the loader returns a void pointer and
+        # validate it before using.
         try:
             ctypes.CDLL(os.path.join(dll_directory, REFIFC_LIB_NAME))
         except OSError:
@@ -158,14 +157,17 @@ class Refifc(object):
             print(f"Refrig {refrig_name} not found, please check!")
 
         func = self.lib.refdll_load
-        func.restype = POINTER(c_void_p)
+        # expect a void* handle from the loader
+        func.restype = c_void_p
         func.argtypes = [c_char_p, c_void_p]
-        # On POSIX the native loader often expects the full SO filename
-        # (e.g. "libR290.so"). We built `ctypes_refrig_name` above to match
-        # that convention; use it when calling the native loader.
-        name_to_pass = ctypes_refrig_name if ctypes_refrig_name else refrig_name
+        name_bytes = refrig_name.encode('utf-8')
         try:
-            self.handle = func(c_char_p(name_to_pass.encode('utf-8')), c_void_p())
+            res = func(c_char_p(name_bytes), c_void_p())
+            if not res:
+                # loader returned NULL -> raise to surface a Python-level error
+                raise OSError(f"refdll_load returned NULL for refrigerant '{refrig_name}'")
+            # store handle as a c_void_p
+            self.handle = c_void_p(res)
         finally:
             # restore cwd even if the native call raises
             try: