= Linux Users =

A '''user''' can refer to either a '''local user''' that a real person uses interactively or a '''system user''' that is used to set permissions on system processes.

<<TableOfContents>>

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== Creating Users ==

See [[AddUser|adduser(8)]] and [[UserAdd|useradd(8)]]. The former is simpler and can be used interactively.



=== Privileged Users ===

Standard practice is that privileged users are in the `wheel` group. This is managed by the sudoers file.

{{{
## Uncomment to allow members of group wheel to execute any command
%wheel ALL=(ALL) ALL
}}}

Either use `visudo` or edit `/etc/sudoers` directly to ensure that this line is uncommented.

Therefore, to escalate a user's privileges, try

{{{
adduser USERNAME wheel
}}}



=== Custom Groups ===

To create a custom group, see [[AddGroup|addgroup(8)]] and [[GroupAdd|groupadd(8)]]. The former is simpler.

Then to add a user to that group, try:

{{{
adduser USERNAME GROUPNAME
}}}

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== Configuration ==

`adduser(8)` and `useradd(8)` both look at `/etc/default/useradd` for a number of variables. The default login shell (`SHELL`), the base directory for home directory creation (`HOME`), and so on.

`adduser(8)` additionally looks to `/etc/logins.def`. Much of this file relates to interactive login configuration, but a short list of variables are used in user creation. `UID_MIN` and `UID_MAX` define the range for local user IDs, while `SYS_UID_MIN` and `SYS_UID_MAX` define the range for system user IDs. (The parallel `GID_MIN`, `GID_MAX`, `SYS_GID_MIN`, and `SYS_GID_MAX` variables do the same for group IDs.)



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