void hw_TmpNamExt(STRPTR buf, int useram);
useram is set to False, hw_TmpNamExt() will never create a file in RAM on AmigaOS
and compatibles. On all other systems there is no difference between hw_TmpNamExt()
and hw_TmpNam().
Please note that this function is potentially dangerous because it doesn't allow you to pass the size of the buffer. This is why you should use hw_TmpNamNew() instead.
This function is thread-safe.
True to allow temporary files in RAM, False to forbid them; this is only
respected on AmigaOS and compatibles