I've stumbled upon surprising (for me) permission behavior on FreeBSD. Let's say I'm operating as non-root user. I create a file, set its permission on read-only and then try to write into it:
$ touch f $ chmod 400 f $ ls -l f -r-------- 1 user wheel f $ echo a >> t t: Permission denied.
So far so good. Now I do the same as root and it writes into the file:
# ls -l f2 -r-------- 1 root wheel f2 # echo a >> f2 # echo $? 0
Is it a bug or intended behavior? Can I safely assume that this would work so on any Unix & Linux?