&gt; pleasedontdelete flag<p>For some programs (rm isn&#x27;t one of them), removing the write permission is sufficient to get an interactive prompt when you try to overwrite&#x2F;truncate&#x2F;delete the file.<p>I really like OSX&#x27;s current metaphor, where files that haven&#x27;t been touched in a while get &quot;locked&quot;, and must then be &quot;unlocked&quot; to modify them further. Phrasing it in terms of stability rather than permission makes a lot of sense to me. It&#x27;s too bad the metaphor isn&#x27;t echoed in the CLI.