USERMOD(8) USERMOD(8)
NAME
usermod - Modify a user account
SYNOPSIS
usermod [-c comment] [-d home_dir [-m]] [-e expire_date]
[-f inactive_days] [-g initial_group]
[-G group1 [,group2,... , [groupN]]] [-l login_name]
[-p passwd(1,5)] [-s shell] [-u uid [-o]] [-L | -U] login(1,3,5)
DESCRIPTION
The usermod command modifies the system account files to reflect the
changes that are specified on the command line.
OPTIONS
The options which apply to the usermod command are:
-c comment
The new value of the user's password file(1,n) comment field. It is
normally modified using the chfn(1)utility.
-d home_dir
The user's new login(1,3,5) directory. If the -m option is given the
contents of the current home directory will be moved to the new
home directory, which is created if(3,n) it does not already exist.
-e expire_date
The date on which the user account will be disabled. The date is
specified in(1,8) the format YYYY-MM-DD .
-f inactive_days
The number of days after a password expires until the account is
permanently disabled. A value of 0 disables the account as soon
as the password has expired, and a value of -1 disables the fea-
ture. The default value is -1.
-g initial_group
The group name or number of the user's new initial login(1,3,5) group.
The group name must exist. A group number must refer to an al-
ready existing group. The default group number is 1.
-G group1[ ,group2,..., [groupN]]]
A list of supplementary groups which the user is also a member
of. Each group is separated from the next by a comma, with no
intervening whitespace. The groups are subject to the same re-
strictions as the group given with the -g option. If the user is
currently a member of a group which is not listed, the user will
be removed from the group.
-l login_name
The name of the user will be changed from login(1,3,5) to login_name.
Nothing else is changed. In particular, the user's home directo-
ry name should probably be changed to reflect the new login(1,3,5)
name.
-L Lock a user's password. This puts(3,n) a '!' in(1,8) front of the encrypt-
ed password, effectively disabling the password. You can't use
this option with -p or -U.
-o When used with the -u option, this option allows to change the
user ID to a non-unique value.
-p passwd(1,5)
The encrypted password, as returned by crypt(3).
-s shell
The name of the user's new login(1,3,5) shell. Setting this field to
blank causes the system to select(2,7,2 select_tut) the default login(1,3,5) shell.
-u uid The numerical value of the user's ID. This value must be unique,
unless the -o option is used. The value must be non-negative.
Values between 0 and 99 are typically reserved for system ac-
counts. Any files which the user owns and which are located in(1,8)
the directory tree rooted at the user's home directory will have
the file(1,n) user ID changed automatically. Files outside of the us-
er's home directory must be altered manually.
-U Unlock a user's password. This removes the '!' in(1,8) front of the
encrypted password. You can't use this option with -p or -L.
CAVEATS
usermod will not allow you to change the name of a user who is logged
in. You must make certain that the named(5,8) user is not executing any pro-
cesses when this command is being executed if(3,n) the user's numerical user
ID is being changed. You must change the owner of any crontab(1,5) files
manually. You must change the owner of any at jobs manually. You must
make any changes involving NIS on the NIS server.
FILES
/etc/passwd(1,5)
user account information
/etc/shadow(3,5)
secure user account information
/etc/group
group account information
SEE ALSO
chfn(1), chsh(1), passwd(1,5)(1), crypt(3), groupadd(8), groupdel(8), group-
mod(8), useradd(8), userdel(8).
AUTHOR
Julianne Frances Haugh (jockgrrl@ix.netcom.com)
USERMOD(8)