Re: [ctypes-users] Can ctypes free memory that be malloced in so

[Thomas H. <th...@ct...>]

Scott Dial schrieb:
> feihu_roger wrote:
>> Thanks, I do as your suggest.
>> 
>> When on windows, after import ctypes, msvcrt is auto loaded. I can directly
>> call:
>> ctypes.cdll.msvcrt71.free(xxxx)
>> 
>> When on Linux, I must manually load libc 
>> a=CLDD('libc.so.6)  or a=cdll.LoadLibrary('libc.so.6')
>> a.free(xxxx)
>> 
> 
> If you care about portability, the general solution for getting at libc 
> has decidedly been:
> 
> import re
> import sys
> from ctypes import *
> 
> def find_msvcr():
>      bytes = open(sys.executable, "rb").read()
>      match = re.search("msvcr([0-9]+|t).dll", bytes, re.IGNORECASE)
>      return match.group(0)
> 
> if sys.platform == 'win32':
>       libc = CDLL(find_msvcr())
> elif sys.platform in ('linux2', 'freebsd6'):
>       libc = CDLL('libc.so.6')
> elif sys.platform == 'darwin':
>       libc = CDLL('libc.dylib')
> else:
>       raise AssertionError("don't know how to get to libc for %s"
>                            % sys.platform)
> 

This is correct for Windows.  For linux and OS X (I'm not sure about
other platforms), it may even be enough to load 'CDLL(None)'.

The libc library is already loaded by Python, and posix exposes all the
functions from a global namespace. AFAIK.

Thomas