In computer software, id is a program in Unix-like operating systems that prints the user or group identifier of the account by which the program is executed; an example of the command id as executed by user alice:
alice@darkstar:~$ id uid=1016(alice) gid=100(users) groups=100(users)The root account has a UID of 0:
root@darkstar:~# id uid=0(root) gid=0(root) groups=0(root)The whoami utility has been obsoleted by the id utility and displays a user's ID as a name:
alice@darkstar:~$ whoami alice alice@darkstar:~$ id -un # Where `-u` refers to `--user` and `-n` refers to `--name` alice