`id` - print real and effective user and group IDs

id [-u] [-g] [-G] [-n] [user]

Options you will use

-u: Print only the effective user ID.
-g: Print only the effective group ID.
-G: Print all group IDs.
-n: Print names instead of numbers (with -u, -g or -G).

Examples

$ id

uid=1000(learner) gid=1000(learner) groups=...

$ id -u

1000 - a handy "am I root?" test: [ "$(id -u)" -eq 0 ]

Taught in

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