Linux in a Nutshell, 6th Edition

Name

usermod

Synopsis

usermod [options] user

System administration command. Modify user account information.

Options

-a, --append

Used with the -G option. Add user to the specified groups, but don’t remove user from groups not in the current list.

-c comment, --comment comment

Comment field.

-d dir, --home dir

Home directory.

-e date, --expiredate date

Account expiration date. date is in the format MM/DD/YYYY; two-digit year fields are also accepted. The value is stored as the number of days since January 1, 1970. This option requires the use of shadow passwords.

-f days, --inactive days

Permanently disable account this many days after the password has expired. A value of −1 disables this feature. This option requires the use of shadow passwords.

-g group, --gid group

Initial group name or number.

-G groups, --groups groups

Supplementary groups given by name or number in a comma-separated list with no whitespace. user will be removed from any groups to which it currently belongs that are not included in groups.

-l name, --login name

Login name. This cannot be changed while the user is logged in.

-L, --lock

Lock user’s password by putting a ! in front of it. This option cannot be used with -p or -U.

-o, --non-unique

Override. Accept a nonunique uid with the -u option.

-p pw, -password pw

Encrypted password, as returned from crypt(3).

-s shell, --shell shell

Login shell.

-u uid, --uid uid

Numerical user ID. The value must be unique unless the -o option is used. Any files owned by user in the user’s home directory ...