Datei-Prüfsumme erstellen

#############################################################################
# returns the checksum of a given file                                      #
#                                                                           #
# takes:   filepath        = full path to the file                          #
#          blocksize       = Block size (optional)                          #
# returns: checksum        = checksum of the file                           #
#############################################################################
 
import hashlib
 
def checksum(filename, blocksize=2**20):
  RC_FILE_ERROR = 1   # File not found or is not readable
 
  md5 = hashlib.md5()
  try:
    with open(filename, "rb") as file:
      while True:
        buf = file.read(blocksize)
        if not buf:
          break
        md5.update(buf)
    return md5.hexdigest()
  except IOError:
    print ("Could not read file: {filename}".format(filename=filename))
    return RC_FILE_ERROR
 
result = checksum("/etc/passwd")
print result