.. efun:: int write_bytes(string file, int start, string str)

  Write string str to file file by overwriting the old bytes at position start. If start is a negative value then it will be counted from the end of the file. The file will not be appended, instead the function will be aborted. Returns 1 for success 0 for failure during execution.

  :history 3.2@232 changed: can now append to the file.

  .. seealso:: :efun:`save_object`, :efun:`write_file`