cd -

changes to the directory you were last in

pushd & popd let you keep a stack

ctrl + z

suspends (SIGTSTP) the running program

fg

brings backgrounded/suspended program to the foreground

bg

starts suspended program & backgrounds it (use after ctrl + z)

shellcheck

(with hearts around it)

shell script linter! helpes spot common mistakes

<( )

(process substitution)

treat process output like a file (no more temp files!)

eg:
$diff <(ls) <(ls -a)

fc

(“fix command”)

open the last command you ran in an editor

then run the edited version

type

tells you if something is a builtin, program, or alias

try running type on

• time
• ping
• pushd

(they’re all different types)