使用ctypes从共享库映射全局变量 [英] Mapping a global variable from a shared library with ctypes
问题描述
我想使用以下方法映射在库 libtorque.so
中声明为全局值的int值 pbs_errno
当前,我可以像这样加载库:
从ctypes import *
libtorque = CDLL( libtorque.so)
并成功映射了一堆函数。但是,出于错误检查的目的,其中许多设置了 pbs_errno
变量,因此我也需要访问它。但是,如果尝试访问它,则会得到:
>> pytorque.libtorque.pbs_errno
< _FuncPtr对象位于0x9fc690>
当然,它不是函数指针,尝试调用它会导致段错误。 p>
在主标头中声明为 int pbs_errno;
,在主标题中声明为 extern int pbs_errno; $ API标头文件中的c $ c>。
Objdump将符号显示为:
00000000001294f8 g DO .bss 0000000000000004基本pbs_errno
ctypes文档中有一节关于访问dll中导出的值:
http://docs.python.org/library/ctypes.html#accessing-values-exported-from-dlls
例如
def pbs_errno():
return c_int.in_dll(libtorque , pbs_errno)
I'd like to map an int value pbs_errno
declared as a global in the library libtorque.so
using ctypes.
Currently I can load the library like so:
from ctypes import *
libtorque = CDLL("libtorque.so")
and have successfully mapped a bunch of the functions. However, for error checking purposes many of them set the pbs_errno
variable so I need access to that as well. However if I try to access it I get:
>>> pytorque.libtorque.pbs_errno
<_FuncPtr object at 0x9fc690>
Of course, it's not a function pointer and attempting to call it results in a seg fault.
It's declared as int pbs_errno;
in the main header and extern int pbs_errno;
in the API header files.
Objdump shows the symbol as:
00000000001294f8 g DO .bss 0000000000000004 Base pbs_errno
There's a section in the ctypes docs about accessing values exported in dlls:
http://docs.python.org/library/ctypes.html#accessing-values-exported-from-dlls
e.g.
def pbs_errno(): return c_int.in_dll(libtorque, "pbs_errno")
这篇关于使用ctypes从共享库映射全局变量的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!