Added binwalk.common.core.debug function

src/binwalk/core/C.py

@@ -47,8 +47,9 @@ class FunctionHandler(object):
 
         Returns None.
         '''
+        self.name = function.name
         self.retype = function.type
-        self.function = getattr(library, function.name)
+        self.function = getattr(library, self.name)
 
         if has_key(self.PY2CTYPES, self.retype):
             self.function.restype = self.PY2CTYPES[self.retype]

src/binwalk/core/common.py

@@ -3,6 +3,7 @@
 import io
 import os
 import re
+import sys
 import ast
 import hashlib
 import operator as op
@@ -14,6 +15,16 @@ if has_key(__builtins__, 'BLOCK_FILE_PARENT_CLASS'):
 else:
     BLOCK_FILE_PARENT_CLASS = io.FileIO
 
+def debug(msg):
+    '''
+    Displays debug messages to stderr only if the Python interpreter was invoked with the -O flag.
+    '''
+    # The __debug__ value is a bit backwards; by default it is set to True, but
+    # then set to False if the Python interpreter is run with the -O option.
+    if not __debug__:
+        sys.stderr.write("DEBUG: " + msg + "\n")
+        sys.stderr.flush()
+
 def file_md5(file_name):
     '''
     Generate an MD5 hash of the specified file.

src/binwalk/core/magic.py

 import binwalk.core.C
+import binwalk.core.common
 from binwalk.core.compat import *
 
 class Magic(object):
@@ -29,8 +30,12 @@ class Magic(object):
         
         self.libmagic = binwalk.core.C.Library("magic", self.LIBMAGIC_FUNCTIONS)
 
+        binwalk.core.common.debug("libmagic.magic_open(0x%X)" % (self.MAGIC_FLAGS | flags))
         self.magic_cookie = self.libmagic.magic_open(self.MAGIC_FLAGS | flags)
+
+        binwalk.core.common.debug("libmagic.magic_load(0x%X, %s)" % (self.magic_cookie, self.magic_file))
         self.libmagic.magic_load(self.magic_cookie, self.magic_file)
+        binwalk.core.common.debug("libmagic loaded OK!")
 
     def close(self):
         if self.magic_cookie: