> Only in Bourne shell & its enhanced clones, I think. IIRC, a friend > who uses (or used) csh or tcsh found that this just errored. (Yes - I > just tried it under csh (on the ancient SYSV system I'm on) and under > tcsh (on a Linux box), and on each I got "Invalid null command".) : >/tmp/file will work on almost every shell on the planet.