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Checking Common File Types in Python?

+2 votes
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I'm trying to create a script that checks all the files in my 'downloaded' directory against common file types and then tells me how many of the files in that directory aren't either a GIF or a JPG file. I'm familiar with basic Python but this is the first time I've attempted anything like this and I'm looking for a little help or a point in the right direction?

file_sigs = {'xFFxD8xFF':('JPEG','jpg'),  'x47x49x46':('GIF','gif')}
def readFile(): filename = r'c:/temp/downloads'  fh = open(filename, 'r')  file_sig = fh.read(4) print '[*] check_sig() File:',filename #, 'Hash Sig:', binascii.hexlify(file_sig) 
posted Dec 1, 2013 by Sumit Pokharna

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1 Answer

+2 votes

file_sigs = {'xFFxD8xFF':('JPEG','jpg'), 'x47x49x46':('GIF','gif')}

file_sig = fh.read(4)

You're reading in four bytes, but your signatures are three bytes long. :)

After that, all you need to do is look up file_sig in the file_sigs dictionary, and see if anything's there. Look at the Python docs for the dict type; there's an easy way to do this.

answer Dec 1, 2013 by Satish Mishra
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