Re: Is python buffer overflow proof?

On Sun, 02 Aug 2009 13:50:14 +0000, Jizzai wrote:

> Is a _pure_ python program buffer overflow proof?

It's supposed to be.

> For example in C++ you can declare a char[9] to hold user input. If the
> user inputs 10+ chars a buffer overflow occurs.
>
> In python, I cannot seem to find a way to define/restrict a string
> length. This is probably by design and raises the topic in question.

That's a separate issue from being buffer overflow proof. You can't
specify that a string have a maximum of N characters except by slicing
the string after it's formed:

s = "x"*10000 # Make a big string.
s = s[:100] # Limit it to 100 characters.

But Python won't overflow any buffers even if you try to create a truly
huge string:

s = "x"*(1024**4) # Try to create a 1 TB string.

Your PC will run slow while Python and the OS tries to allocate 1TB of
memory, then it will safely raise MemoryError. Pure Python should never
dump core.



--
Steven

Steven D'Aprano