How to print contents of ctypes string buffer

Question

I am creating a string buffer using ctypes library in python. Now if I have to print contents of this string buffer later when it has been written, how will i achieve that in python?

import ctypes
init_size = 256
pBuf = ctypes.create_string_buffer(init_size)

Answer 1

You can use the .value and .raw properties to access and manipulate them. This is documented far down in this part of the ctypes docs.

Here is some of the example code from that section:

>>> from ctypes import *
>>> p = create_string_buffer(3)            # create a 3 byte buffer, initialized to NUL bytes
>>> print(sizeof(p), repr(p.raw))
3 b'\x00\x00\x00'
>>> p = create_string_buffer(b"Hello")     # create a buffer containing a NUL terminated string
>>> print(sizeof(p), repr(p.raw))
6 b'Hello\x00'
>>> print(repr(p.value))
b'Hello'
>>> p = create_string_buffer(b"Hello", 10) # create a 10 byte buffer
>>> print(sizeof(p), repr(p.raw))
10 b'Hello\x00\x00\x00\x00\x00'
>>> p.value = b"Hi"
>>> print(sizeof(p), repr(p.raw))
10 b'Hi\x00lo\x00\x00\x00\x00\x00'
>>>

Answer 2

According to the Python Ctypes docs at: https://docs.python.org/2/library/ctypes.html

You should be able to print the string buffer value using the .value object property ie:

print repr(pBuf.value) 

Or if you want to get a bit fancy with the io you can use something like:

print "pBuff: %s" % pBuf.value