]), [[ ... ]] 檔案目錄 touch, ln, mkdir, cp, rm, rmdir, file, pwd, cd, ls, chown, chmod, mv, more, tail, df, locate, cat, source(.), mount 系統資訊、行程 date, uname, id, help, type, which, hash, history, man, ps, sleep, sync, time, kill, exec, exit, return, reboot, poweroff 輸出輸入、數值邏輯 echo, printf, read, xargs, seq, tee, expr, let, bc, true(:), false