I tried this on Opensuse 12 and Fedora 17, i use the following commans
touch file chown 777 file ls -l file -rw-r--r-- 1 777 root 0 Oct 9 21:43 file grep 777 /etc/passwd echo $? 1
There is no user 777
grep pippo /etc/passwd echo $? 1 chown pippo file chown: invalid user: `pippo'
But if i use non-existing user, i get one error.
Why can i use numeric non-existing user with chown, but not with names?