shell tricks

[Uj947nXmRqV2nRaWshKtHzTvckUUpD]

it would ve nice to include most common shell tricks and capabilities:

parameters expansion variable expansion process redirection command substitution variable substitution variable functions arithmetic operations if (+all its commands), while, case, for special variables arrays string operations (eg substring, replacements) traps pipelines common pipeline commands (grep, awk, sed, head, wc, tail, tee, sort, uniq) some regex special characters (escaping, new line) set, declare seq

• others

it might be out of scope as they are not commands in the real sense, but it would be useful to have an all in one pocket app