If root's PATH environment variable can be compromised, then you might as well ditch the whole system.

It may not be common practice (I typically rely on $PATH). But it is, as I noted, defensive.

There are numerous ways in which $PATH can change. Shared profiles and other users modifying root's init among them. Intent isn't necessarily malicious. It can still be unexpected.

There was a Steam script that had a nasty habit of running '# rm /*' due to an empty script variable.

I do not trust vendor scripts.

Really fscking annoying: scripts that include inline binary data.

The first google result for qmail:

> qmail is a mail transfer agent (MTA) that runs on Unix. It was written, starting December 1995, by Daniel J. Bernstein as a more secure replacement for the popular Sendmail program; qmail's source code is in the public domain.

Wrong question.

Not "what is the application 'qmail'" (I'm quite aware, thanks). But "what is the token 'qmail'" evaluated to by the shell.

If you prefer: "which qmail".

That's a a good question. The mail client (most boxes uses mailx to implement it these days) is normally just 'mail'. and qmail would normally be in an sbin dir.

Note: the question applies to all executed commands.

Sorry, I misunderstood you. I retract my snark :)