creates a file with an unique filename
tmp_name = tempname([prefix])
a string
a string: prefix of filename (On Windows, 3 characters maximum).
The tempname creates a file with an unique
filename in the TMPDIR directory.
tmp_name = tempname() returns an unique string,
tmp_name, suitable for use as a temporary filename.
| Version | Description |
| 5.4.0 | Function tempname introduced. |