Why does 'sudo poweroff' work but 'poweroff' doesn't when I'm already root?

Thanks for the tips, everyone! I've realized that I often default to using 'sudo' without considering other ways to switch to root. I’ll give 'su -' and other commands a try next time!

If you're still having trouble, you might consider using 'shutdown' as an alternative. It works well, although it behaves slightly differently than 'poweroff'. Just a thought!

When you're using 'su' to switch to root, it doesn't automatically set up your environment the same way as logging in directly as root would. This can affect the $PATH variable, which determines where your shell looks for commands. For example, 'poweroff' is located in '/usr/sbin', which is typically included in the root user's $PATH but not for normal users. If you want to get the root environment, you should use 'su -' instead of just 'su'. That way, your shell will locate 'poweroff' without problems.

You know, I’ve noticed something different between distros. On Ubuntu, 'poweroff' works directly as a root user, while on Arch it sometimes requires 'sudo'. The location of binaries in the PATH plays a big role. So, it may vary depending on your system setup.