How to create a temporary file with portable shell in a secure way?

Question

I want to create a temporary file in POSIX shell (/bin/sh).

I found out that mktemp(1) doens\'t exist on my AIX box, and according to How port

Answer 1

Why not use /dev/random?

It could be neater with perl but od and awk will do, something like:

tempfile=XXX-$(od -N4 -tu /dev/random | awk 'NR==1 {print $2} {}')