everything not useful. e.g.: unusable stuff. like nasty memory confusion.

function explored at any rate and level in computer systems. that's why: use only frequently when really required.

remark :/! which is a dangerous term on it's own; require(d)!

rm -f * ## but do not as root.

rm -rf .* ## cause this would be so dangerous. try out never ever even not only on other peoples networks.

H. All kind of.