new_contents: #!/usr/bin/env python
  # Check whether a file contains valid UTF-8
  # From http://stackoverflow.com/a/3269323
  
  import codecs
  import sys
  
  
  def checkFile(filename):
      try:
          with codecs.open(filename, encoding='utf-8', errors='strict') as f:
              for line in f:
                  pass
          return 0
      except IOError as e:
          sys.stderr.write('IO error: %s\n' % e)
          return 2
      except UnicodeDecodeError:
          sys.stdout.write('%s contains invalid UTF-8\n' % filename)
          return 1
  
  
  if __name__ == '__main__':
      if len(sys.argv) != 2:
          p = sys.argv[0]
          sys.stderr.write('Usage: ' + p[p.rfind('/') + 1:] + ' <filename>\n')
          sys.exit(2)
      r = checkFile(sys.argv[1])
      sys.exit(r)
  
subject: Add script for checking file is valid utf8