Replace text in a binary file, padding the replacement text with spaces

binary_search_replace.py

#!/usr/bin/env python3
# Replace text in a binary file, padding the replacement text with spaces

import sys, locale
if len(sys.argv) != 3:
  sys.stderr.write("Usage: %s string_from string_to < input.bin > output.bin.\n" % (sys.argv[0],))
  sys.exit(1)

codec = locale.getpreferredencoding()
orig= bytes(sys.argv[1], codec)
txt = bytes(sys.argv[2], codec)
txt = (txt + bytes([ord(' ')] * len(orig)))[:len(orig)]
oldbin = sys.stdin.buffer.read()
newbin = oldbin.replace(orig, txt)
sys.stdout.buffer.write(newbin)