Index[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] [X] [Y] [Z] I/O STDIN 2nd 3rd 4th STDOUT 2nd I/O redirection 2nd pipes 2nd STDERR 2nd if command if conditional statement incremental backups verifying with touch comman info help format 2nd input STDIN 2nd 3rd 4th insert mode (vi editor) interactive mode removing files with rm command IP_ addressing |