Useful script for bulk renaming files on the basis of their type.

bulk_rename.py

# Small script which uses the "file" command to
# determine the types of all files in the current
# directory with names starting with '#'.
#
# It then sets the file extension as appropriate.
# Written to recover data from a badly damaged filesystem's
# lost&found folder, after testdisk.
#
# Author: Richard Hofman, 2015
#
# This script is licensed under the MIT License.

#!/usr/bin/python

import subprocess
import os

extensions = {
                'JPEG image data': 'jpg',
                'RAR archive data': 'rar',
                'avi': 'avi',
                'ISO Media': 'iso',
                'Matroska': 'mkv',
                'MPEG sequence, v2': 'mpg',
                'XML document text': 'xml',
                'Zip archive data': 'zip',
                'PDF document': 'pdf',
                'PE32 executable': 'exe',
                'Microsoft Word 2007+': 'docx',
                'SQLite 3.x database': 'sqlite',
                'Rich Text Format': 'rtf',
        }


def main():
	type_mappings = {}

	listing = subprocess.check_output("file $( ls | awk '/^#/' )", shell=True)
	print "LISTING\n\n" + listing
	for l in listing.split('\n'):
		l = l.strip()
		if len(l) == 0:
			continue
		print "Processing %s" % l
		index = l.find(':')
		filename = l[:index]
		type = (l[index+1:]).strip()
		type_mappings[filename] = lookup_extension(type)

	for filename, extension in type_mappings.iteritems():
		if len(extension) == 0:
			print "NOT renaming: %s" % filename
			continue
		print "Renaming: %s" % filename
		new_filename = "%s.%s" % (filename, extension)
		new_filename = new_filename[1:]
		os.rename(filename, new_filename)


def lookup_extension(type_string):
	type_string = type_string.lower()
	debug = ""
	for ts, te in extensions.iteritems():
		if ts.lower() in type_string:
			return te
	return ""


if __name__ == "__main__":
	main()