I always hear people say it's POSIX compliant, and that they took a lot from FreeBSD and NeXTSTEP. But in reality, how unix like is OSX? If I opened up a terminal, entered sudo bash, (I already read that OSX doesn't come with a root user by default) and entered the command "chmod -R a+rwx /", would it actually do it what it would do on a real UNIX like OS? Would a bash script containing nothing but basic *NIX utils work as I would expect it to on OSX? If anyone here has a lot of experience with Linux or other UNIX like operating systems, how similar would you say OSX is?