use real arrays not whitespace separated pseudo-array strings
use real arrays not whitespace separated pseudo-array strings

https://github.com/anordal/shellharden/blob/master/how_to_do_things_safely_in_bash.md
Safe ways to do things in bash 
https://news.ycombinator.com/item?id=17057596
Aurametrix/Alg-U,Aurametrix/Alg-U