pyptrs 1.0.0

Real pointers and some memory utilities for python

pyptrs

This library provides real pointers (as in languages like C) and some memory access utilites.

Installation

pip install pyptrs

Creating A Pointer

You should never create pointers directly. Instead, use the functions below:

pyptrs.pointer_to_object(obj, c_object = False)

Return a pointer to obj. c_object specifies whether to treat the obj as a python type or a C type. If c_object is True, obj must be an instance of a ctypes C data type. You can learn more information about these data types from here, here and here

pyptrs.pointer_to_address(address, ctype = None)

Return a pointer that points to the given address. If ctype is None, a python object is assumed to be living in that address. Otherwise, ctype must be ctypes C data type. You can learn more information about these data types from here, here and here

Pointer Objects

Pointer.get_size()

Return the number of bytes occupied by the pointed object in memory.

Pointer.get_mem()

Return a bytes object representing the pointed object.

Pointer.temp_value(value, force_write = False)

Dereference and assign value to the pointed object, then return a context manager that reverts this assignment at exit. If size of value is bigger than the pointed object, a MemoryError will be raised. In order to prevent this, pass True to force_write.

Simulated Operators

pyptrs.dereference(pointer, *value, force_write = False)

If value is not given, it just dereferences the pointer. If value is given, it must be a single argument and it dereferences the pointed object and assigns value to it then returns a backup_id that can be passed to pyptrs.mem_restore(). If size of value is bigger than the pointed object, a MemoryError will be raised. In order to prevent this, pass True to force_write. Type of value can be anything if the pointed object is a python object. If the type of the pointed object is a C type, type of value must be the corresponding ctypes C data type.

pyptrs.address_of(obj, c_object = False)

Return address of the obj. If c_object is True type of obj must be a ctypes C data type. You can learn more information about these data types from here, here and here If c_object is True, address of the actual C object is returned, not the address of its ctypes wrapper.

Utils

pyptrs.mem_read(address, amount = 1)

Read amount bytes starting from address and return them as a bytes object.

pyptrs.mem_write(address, data = b"")

Write the bytes represented by data to address and return a backup_id that can be passed to pyptrs.mem_restore().

pyptrs.mem_restore(backup_id)

Revert the changes done to memory by the function that returned backup_id.

pyptrs.mem_restore_last()

Revert the last change done to memory either by pyptrs.dereference() or pyptrs.mem_write().