usermod(1M) usermod(1M)
NAME
usermod - modify a user's login information on the system
SYNOPSIS
usermod [-u uid [-o]] [-g group] [-G group[,group...] [-d dir [-m]] [-s shell]
[-c comment] [-l new_logname] [-f inactive] [-e expire] login
DESCRIPTION
The usermod command modifies a user's login definition on the system.
It changes the definition of the specified login and makes the
appropriate login-related system file and file system changes.
The system file entries created with this command have a limit of 512
characters per line. Specifying long arguments to several options
may exceed this limit.
The following options are available:
-u uid
New UID for the user. It must be a non-negative decimal
integer below MAXUID as defined in <param.h>.
-o This option allows the specified UID to be duplicated (non-
unique).
-g group
An existing group's integer ID or character-string name. It
redefines the user's primary group membership.
-G group
An existing group's integer "ID" "," or character string name.
It redefines the user's supplementary group membership.
Duplicates between group with the -g and -G options are
ignored. No more than NGROUPSUMAX groups may be specified as
defined in <param.h>.
-d dir
The new home directory of the user. It defaults to
base_dir/login, where base_dir is the base directory for new
login home directories, and login is the new login.
-m Move the user's home directory to the new directory specified
with the -d option. If the directory already exists, it must
have permissions read/write/execute by group, where group is
the user's primary group.
-s shell
Full pathname of the program that is used as the user's shell
on login. The value of shell must be a valid executable file.
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-c comment
Any text string. It is generally a short description of the
login, and is currently used as the field for the user's full
name. This information is stored in the user's /etc/passwd
entry.
-l new_logname
A string of printable characters that specifies the new login
name for the user. It may not contain a colon (:) or a newline
(\n).
-e expire
The date on which a login can no longer be used; after this
date, no user will be able to access this login. (This option
is useful for creating temporary logins.) You may type the
value of the argument expire (which is a date) in any format
you like (except a Julian date). For example, you may enter
10/6/90 or October 6, 1990. A value of `` '' defeats the
status of the expired date.
-f inactive
The maximum number of days allowed between uses of a login ID
before that login ID is declared valid. Normal values are
positive integers. A value of -1 defeats the status.
login A string of printable characters that specifies the existing
login name of the user. It must exist and may not contain a
colon (:), or a newline (\n).
FILES
/etc/passwd, /etc/shadow, /etc/group
SEE ALSO
groupadd(1M), groupdel(1M), groupmod(1M), logins(1M), passwd(1),
passwd(1M), useradd(1M), userdel(1M), users(1).
DIAGNOSTICS
The usermod command exits with one of the following values:
0 The command was executed successfully.
2 The command syntax was invalid. A usage message for the
usermod command is displayed.
3 An invalid argument was provided to an option.
4 The uid given with the -u option is already in use.
6 The login to be modified does not exist or group does not
exist.
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8 The login to be modified is in use.
9 The new_logname is already in use.
10 Cannot update the /etc/group file. Other update requests will
be implemented.
11 Insufficient space to move the home directory (-m option).
Other update requests will be implemented.
12 Unable to complete the move of the home directory to the new
home directory.
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