758
tar -vczfx123 ought to do it
(imgs.xkcd.com)
img title="I don't know what's worse--the fact that after 15 years of using tar I still can't keep the flags straight, or that after 15 years of technological advancement I'm still mucking with tar flags that were 15 years old when I started."
OK now I have to escape to really smart assery and assume that's what I meant the whole time ;)
Edit code 2 describes something that went wrong - but that something telling you that it went wrong was the tar binary which therefor most have been valid to evaluate that!
Under no circumstances did I assume that the hint towards help itself would've been an exit code 0, no sir!
To be honest: if I'd designed that bomb it would've exploded in my face for trying to be too clever.