Features

-c 'check this'
Things that never work: $10 and [ -n $var ]: Fail by default, add --unbreak/--fix-neverworking
--keep-varbraces

Rewriting

sort | uniq → sort -u (man 1p sort approves)
alias → function
eval is evil: Color blinking red?
for i in seq → for ((i…))
for i in … → while read < <(…)

Code organisation

reduce perilous boilerplate
- make flush an error for easier propagation
approach agreement with rust-fmt

Write about:

errexit → errtrace ?
Gotcha: Command substitution "$()" trims whitespace
Useless uses of find
cp file dir → cp file dir/
realpath → readlink -f ?