In my Go application instead of writing to a file directly I would like to write to a temporary that is renamed into the final file when everything is done. This is to avoid leaving partially written content in the file if the application crashes.
Currently I use ioutil.TempFile, but the issue is that it creates the file with the 0600 permission, not 0666. Thus with typical umask values one gets the 0600 permission, not expected 0644 or 0660. This is not a problem is the destination file already exist as I can fix the permission on the temporary to much the existing ones, but if the file does not exist, then I need somehow to deduce the current umask.
I suppose I can just duplicate ioutil.TempFile implementation to pass 0666 into os.OpenFile, but that does not sound nice. So the question is there a better way?