dealing with binary files

[Guilherme Polo]

2008/1/7, Gerardo Herzig <gherzig at fmed.uba.ar>:
> Hi all. Im trying to read a binary data from an postgres WAL archive.
> If i make a
> xfile = open('filename', 'rb').xreadlines()
> line = xfile.next()
>
> i see this sort of thing:
> ']\xd0\x03\x00\x01\x00\x00\x00\r\x00\x00\x00\x00\x00\x00JM//DI+,D\x00\x00\x00\x01$\x00\x00\x00\x7f\x06\x00\x00y\r\t\x00\x02\x0f\t\x00\x00\x00\x10\x00)\x00\x01\x00\x12\x08
> \x00^\xc2\x0c\x00\x08\x00\x00\x003001({\xe8\x10\r\x00\x00\x00\xe4\xff\xffI\x10?l\x01@\x00\x00\x00$\x00\x00\x00\x00\n'
>
> This file suppose to have some information about database activity, but
> at this point i cant do more than this, because i cant figure out what
> to do in order to have some 'readable' text.
>
> Im guessing is some C code, im reading the struct module to see if it
> helps, but im not into C programming, and im lost at the start of my
> problem.

You are looking at the correct module, struct. But in order to
understand or even correctly extract data from a binary file, you need
to know its structure. There should be some document describing the
Postgre WAL file format.

>
> Can someone point me out some advice?
> Thanks!
>
> Gerardo
> --
> http://mail.python.org/mailman/listinfo/python-list
>


-- 
-- Guilherme H. Polo Goncalves