Avoid hard coded /tmp directory

[jfdenise]

In the scripts that use /tmp dir, this could be replaced by: tmpdir="${TMPDIR:-/tmp}"

[yersan]

The use case sounds very strange to me, I don't see the use case yet. We can change it and replace their uses, but it will increase the "complexity" of keeping up additional PRs that include script files safe regarding not to use /tmp as the default one.

Having said that, so you still see it useful?, if so, I can create a PR with the required changes

[jfdenise]

@yersan , I just created this issue not to loose feedbacks provided during a review. If your analysis show that this is not that useful and would create complexity, we certainly can not address it.