docs: def escape_filename_sh(name):
      """Return a hopefully safe shell-escaped version of a filename."""
  
      # check whether we have unprintable characters
      for ch in name:
          if ord(ch) < 32:
              # found one so use the ansi-c escaping
              return escape_filename_sh_ansic(name)
  
      # all printable characters, so return a double-quoted version
      name.replace('\\','\\\\')
      name.replace('"','\\"')
      name.replace('`','\\`')
      name.replace('$','\\$')
      return '"'+name+'"'