catbytes.sh

#!/bin/sh

py_script='

import mmap, base64, sys, getopt

def main(argv):
   inputfile = ""
   needle = b""
   try:
      opts, args = getopt.getopt(argv,"hi:n:",["ifile=","needle="])
   except getopt.GetoptError:
      print "catbytes.sh -i <inputfile> -n <needle>"
      sys.exit(2)
   for opt, arg in opts:
      if opt == "-h":
         print "catbytes.sh -i <inputfile> -n <needle>"
         sys.exit()
      elif opt in ("-i", "--ifile"):
         inputfile = arg
      elif opt in ("-n", "--needle"):
         needle = base64.b64decode(arg)
   with open(inputfile, "a") as f:
      f.write(needle)

if __name__ == "__main__":
   main(sys.argv[1:])
'

python -c "$py_script" "$@"