I need perl or python script to list all functions that are called but
not defined in the current file.

Why not just compile the file to a .o and run the nm command on them? 
It will tell you what all your undefined references are.

To do this with a script would be much more complicated than you might
think.  Things that look undefined might actually be defined (as
macros perhaps) in a header file.

Answering a question like this is impossible without investing much
time and work. You might want to have a look at the Google Answers
pricing guide:
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