Access c_char_p_Array_256 in Python using ctypes

Question

I have a native python bridge to some C code, which returns a pointer to an array (array of structs). The struct contains some character arrays (strings). But how can I get from a c_char_p_Array_NNN to an actual Python string?

typedef struct td_Group
{
    unsigned int group_id;
    char groupname[256];
    char date_created[32];
    char date_modified[32];
    unsigned int user_modified;
    unsigned int user_created;
} Group;

int getGroups(LIBmanager *, Group **);

############# python code below: 
class Group(Structure):
    _fields_ = [("group_id", c_uint),
                ("groupname", c_char_p*256),
                ("date_created", c_char_p*32),
                ("date_modified", c_char_p*32),
                ("user_modified", c_uint),
                ("user_created", c_uint)]


def somefunc():
    myGroups = c_void_p()
    count = libnativetest.getGroups( nativePointer, byref(myGroups) )
    print "got " + str(count) + " groups!!"
    myCastedGroups = cast( myGroups, POINTER(Group*count) )
    for x in range(0,count):
        theGroup = cast( myCastedGroups[x], POINTER(Group) )
        theGroupName = theGroup.contents.groupname 
        ### Now how do I access theGroupName as a python string?
        # it is a c_char_p_Array_256 presently

ephemient · Accepted Answer · 2011-11-29 16:56:59Z

2

The type should be c_char*256, not c_char_p*256, because it's a char[256], not a char *[256].

string_at(theGroupName, sizeof(theGroupName))

answered Nov 29, 2011 at 16:56

ephemient

206k39 gold badges292 silver badges402 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Access c_char_p_Array_256 in Python using ctypes

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related