Found two nice shell scripting idioms recently.

  Variables and default values, by [1]:

    1   : "${m:=12}"

  Which is a short version of this:

    1   [[ -z "$m" ]] && m=12

  Using a free fd to read from in while loops, which leaves the original
  STDIN untouched, by [2]:

    1   while read -r <&3
    2   do
    3      ... whatever ...
    4   done 3<data

  ____________________

  1. https://github.com/c00kiemon5ter/iii/blob/36728389151c7ce558b5acb61b64597662c6f018/iii.sh#L9

  2. https://github.com/s-p-k/foxy/blob/08225ca788e16568885d82cd43383970b5589648/foxy#L116