I'm walking through Hal Pomeranz's older Command-Line Kung Fu postings, both because I know there'll be useful stuff and because he has some fun challenges.
His Episode #19 attacks zeroing out an existing file. The solutions suggested are
cat /dev/null > my_fileand
cp /dev/null my_file(which is both shorter and works even if noclobber is set, to prevent accidentally overwriting pre-existing files with > ).
Both of these are more typing than necessary. This works just as well:
> my_fileand never even invokes a command. It's all done by the shell.
What's that? You're running with set -o noclobber ?
>| my_fileIf you want to do it in fewer characters, you can omit the space. :-)
Cut! It's a wrap.