title: How to create a temporary file with portable shell in a secure way?
body: <p>I want to create a temporary file in POSIX shell (<code>/bin/sh</code>). </p>
  
  <p>I found out that <code>mktemp(1)</code> doens't exist on my AIX box, and according to <a href="https://stackoverflow.com/questions/2792675/how-portable-is-mktemp1">How portable is mktemp(1)?</a>, it isn't that portable and/or secure anyway.</p>
  
  <p>So, what should I use instead ?</p>