Shell Joke

< > ! * ' ' #

^ " ` $ $ -

! * = @ $ _

% * < > ~ # 4

& [ ] . . /

| { , , SYSTEM HALTED

which translates to:

Waka waka bang splat tick tick hash, Caret quote back-tick dollar dollar dash, Bang splat equal at dollar under-score, Percent splat waka waka tilde number four, Ampersand bracket bracket dot dot slash, Vertical-bar curly-bracket comma comma CRASH!