Search for a specific string in all files, not just text

whatcontains.py

import os,sys
def usage():
	print 'Usage: whatcontains [-case] [-hex] stringToSearchFor [folderToSearchIn]'
	exit()
if not 1<len(sys.argv)<6: usage()
case=False
hex=False
if '-case' in sys.argv:
	case=True
	sys.argv.remove('-case')
if '-hex' in sys.argv:
	hex=True
	sys.argv.remove('-hex')
if hex: stringToSearchFor=sys.argv[1].decode('hex')
else: stringToSearchFor=sys.argv[1]
if len(sys.argv)==2: folderToSearchIn='.'
else: folderToSearchIn=sys.argv[2]
for root, dirnames, filenames in os.walk(folderToSearchIn):
	for i in filenames:
		a=open(root+'/'+i,'rb').read()
		condition=stringToSearchFor in a
		if case: condition=condition or stringToSearchFor.upper() in a or stringToSearchFor.lower() in a
		if condition: print root+os.path.sep+i