[Tutor] using while loop for read process memory

[Michael C]

Here is my question about the memory:

So I have a base address of a chunk of memory from it's size, from
VirtualQueryEx
(if you dont use windows, it's ok, it's not about how u get these values,
because I think
the base concept is the same)

start = mbi.BaseAddress
finish = mbi.RegionSize

So at this time, I use while and this is how it looks like

while index < finish:
   # access the memory here:
   while memory function( index)
   # then index += 1, for the inner loop

## this line complete the outer while loop
index += mbi.RegionSize


so Why did I put down index += 1  ?

That's because what I think about the memory looks like this
(short)(int)(double)(int)(int)(int)(double)  and so on,

since I can't predict which address is the beginning of a double, the only
way
to deal with that is to use increment by 1.

Now, from what I have been reading, it seems there is a better way to do it,
for instance, a for loop.

for(start,finish, 8)

why 8? because double begins at exact 0 or multiple of 8 bytes, right?



On Sun, Oct 8, 2017 at 4:46 PM, Alan Gauld via Tutor <tutor at python.org>
wrote:

> On 08/10/17 20:18, Michael C wrote:
> > This is the red part
> >   index = current_address
> >         end = current_address + mbi.RegionSize
> >
> >         while index < end:
> >             if ReadProcessMemory(Process, index, ctypes.byref(buffer), \
> >                                  ctypes.sizeof(buffer),
> > ctypes.byref(nread)):
> >                 ## value comparison to be implemented.
> >                 pass
> >             else:
> >                     raise ctypes.WinError(ctypes.get_last_error())
> >
> >             index += 1
>
> I haven't been following this closely so may be way off here,
> but does this mean you are incrementing the memory address
> by 1? If so you are only increasing the pointer by 1 byte
> but you are, presumably, reading multiple bytes at a time
> (the size of the buffer presumably).
>
> Do you perhaps need to treat the buffer as a byte array
> and use something like the struct module to decode it?
> (assuming you know what you are reading...?)
>
> But I may be way off, I'm just going on a cursory look.
>
> --
> Alan G
> Author of the Learn to Program web site
> http://www.alan-g.me.uk/
> http://www.amazon.com/author/alan_gauld
> Follow my photo-blog on Flickr at:
> http://www.flickr.com/photos/alangauldphotos
>
>
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