Help me with this!!!

[Steven D'Aprano]

On Thu, 01 Feb 2007 08:53:55 -0800, Ravi Teja wrote:

>> > > It search a text inside that hex value.
>> > > It works perfecly on a txt file but if I open a binary file (.exe,.bin
>> > > ecc...) with the same value it wont work, why?
>> > > Please help!
>>
>> > Because the pattern isn't in the file, perhaps.
>>
>> This pattern IS in the file (I made it and I double check with an hex
>> editor).
>> It display the file correcltly (print line) but...
> 
> No! Peter is right. Regular expressions match ASCII representation of
> data, not hex. In simple terms, do you see your pattern when you open
> the file in notepad (or other text editor)? You do not use regex to
> search binary files.

I don't see why not.

>>> pattern = "NULL\0"
>>> source = "\0\01\02-more-bytes-here-NULL\0-more-bytes"
>>> m = re.search(pattern, source)
>>> m.group()
'NULL\x00'
>>> m.span()
(20, 25)

Here's the Original Poster's code again:


    regex = re.compile(r"(?si)(\x8B\xF0\x85\xF6)(?P<contents>.*)
(\xC6\x44\x24)",re.IGNORECASE)
    file = open(fileName, "rb")
    for line in file:
          if (match):
              print line
    file.close()

I suggest that the reason it doesn't work is because he never actually
uses the regex. Presumably the name "match" was assigned somewhere else to
a false value, and so the code simply walks through the file doing nothing.


-- 
Steven D'Aprano