F11: Bug in sh-4.0 source build-in command

[Konstantin Svist]

John Cornelius wrote:
> It's not a bug, it's supposed to work that way. The behavior can be
> changed by:
> sh-4.0# PATH=$PATH:.

I used to do this because that's how Windows does it -- until I realized
how bad of an idea it really is.

Suppose you're root, looking around in a user-writable directory. And
suppose that some user placed a malicious executable called "ls" in that
directory (maybe as simple as echo "rm -rf /" >> ls; chmod 777 ls).
Suddenly, you're executing "ls" - but not the one you think.