Linux · User & Group Administration

UIDs have well-known ranges — GIDs have their own conventions too. How are GID numbers partitioned, and what constraint links the GID in /etc/passwd to /etc/group?

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More in User & Group Administration

Ubuntu tells you never to log in as root and instead run admin tasks through your own account with sudo. What is the actual state of the root account on such a system, and why does that make it a non-issue to leave root passwordless?

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Debian gives you both adduser and useradd, and so does Fedora — but a script that works on Debian's adduser can misbehave on Fedora. Why?

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