find /tmp /usr/tmp -atime +7 -print | xargs /bin/rm -f
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$ mkdir -p "/tmp/foo
/etc" # yes, that's a newline after foo before the /etc
$ touch "/tmp/foo
/etc/passwd" # yes, that's a newline after foo again
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The problem is that you are using newline as a delimiter, and yet it is a legal filename character. You need find .. -print0 and xargs with a -0, but that's not portable. Even though Perl isn't strictly everywhere, it's everywhere the perlmonks are, so my solution succeeds in a safe way.

-- Randal L. Schwartz, Perl hacker

Ouch! nice one merlyn Can I vote myself down for leaving crap find commands on nearly every server I've accessed?

I would have used:

find /somewhere/or/something -atime +7 -exec rm -v {} \;
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Then there arn't any chars that can freak it out. If not a -exec I simply wouldn't use find for it. update: ahh... an excelent point merlyn. Perl rules!

Got Perl?

And that causes a separate process invocation on each file, so as a denial of service attack, I can create hundreds of thousands of empty files in /tmp, and you end up firing a separate rm for each.

The Perl solution is still the best. Fewest processes, and no problem with special characters in the filename.

-- Randal L. Schwartz, Perl hacker