Provided by: passwd_4.13+dfsg1-4ubuntu3.2_amd64 
名称
usermod - 修改一个用户账户
大纲
usermod [选项] 登录
描述
The usermod command modifies the system account files.
选项
The options which apply to the usermod command are:
-a, --append
Add the user to the supplementary group(s). Use only with the -G option.
-b, --badname
Allow names that do not conform to standards.
-c, --comment COMMENT
update the comment field of the user in /etc/passwd, which is normally modified using the chfn(1)
utility.
-d, --home HOME_DIR
用户的新登录目录。
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 it does not already exist. If the current home directory does not
exist the new home directory will not be created.
-e, --expiredate EXPIRE_DATE
The date on which the user account will be disabled. The date is specified in the format YYYY-MM-DD.
Integers as input are interpreted as days after 1970-01-01.
An input of -1 or an empty string will blank the account expiration field in the shadow password
file. The account will remain available with no date limit.
This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.
-f, --inactive INACTIVE
defines the number of days after the password exceeded its maximum age during which the user may
still login by immediately replacing the password. This grace period before the account becomes
inactive is stored in the shadow password file. An input of 0 will disable an expired password with
no delay. An input of -1 will blank the respective field in the shadow password file. See shadow(5)
for more information.
This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.
-g, --gid GROUP
The name or numerical ID of the user's new primary group. The group must exist.
用户主目录中，属于原来的主组的文件将转交新组所有。
主目录之外的文件所属的组必须手动修改。
The change of the group ownership of files inside of the user's home directory is also not done if
the home dir owner uid is different from the current or new user id. This is a safety measure for
special home directories such as /.
-G, --groups 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 must exist.
If the user is currently a member of a group which is not listed, the user will be removed from the
group. This behaviour can be changed via the -a option, which appends the user to the current
supplementary group list.
-l, --login NEW_LOGIN
The name of the user will be changed from LOGIN to NEW_LOGIN. Nothing else is changed. In particular,
the user's home directory or mail spool should probably be renamed manually to reflect the new login
name.
-L, --lock
Lock a user's password. This puts a '!' in front of the encrypted password, effectively disabling the
password. You can't use this option with -p or -U.
Note: if you wish to lock the account (not only access with a password), you should also set the
EXPIRE_DATE to 1.
-m, --move-home
moves the content of the user's home directory to the new location. If the current home directory
does not exist the new home directory will not be created.
This option is only valid in combination with the -d (or --home) option.
usermod will try to adapt the ownership of the files and to copy the modes, ACL and extended
attributes, but manual changes might be needed afterwards.
-o, --non-unique
allows to change the user ID to a non-unique value.
This option is only valid in combination with the -u option. As a user identity serves as key to map
between users on one hand and permissions, file ownerships and other aspects that determine the
system's behavior on the other hand, more than one login name will access the account of the given
UID.
-p, --password PASSWORD
defines a new password for the user. PASSWORD is expected to be encrypted, as returned by crypt (3).
Note: Avoid this option on the command line because the password (or encrypted password) will be
visible by users listing the processes.
The password will be written in the local /etc/passwd or /etc/shadow file. This might differ from the
password database configured in your PAM configuration.
您应该确保密码符合系统的密码政策。
-r, --remove
Remove the user from named supplementary group(s). Use only with the -G option.
-R, --root CHROOT_DIR
Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR
directory. Only absolute paths are supported.
-P, --prefix PREFIX_DIR
Apply changes within the directory tree starting with PREFIX_DIR and use as well the configuration
files located there. This option does not chroot and is intended for preparing a cross-compilation
target. Some limitations: NIS and LDAP users/groups are not verified. PAM authentication is using the
host files. No SELINUX support.
-s, --shell SHELL
changes the user's login shell. An empty string for SHELL blanks the field in /etc/passwd and logs
the user into the system's default shell.
-u, --uid UID
The new value of the user's ID.
This value must be unique, unless the -o option is used. The value must be non-negative.
用户的邮箱，用户主目录中属于此用户的文件的属主 ID 也将自动更改。
用户主目录之外文件所有权必须手动修复。
The change of the user ownership of files inside of the user's home directory is also not done if the
home dir owner uid is different from the current or new user id. This is a safety measure for special
home directories such as /.
No checks will be performed with regard to the UID_MIN, UID_MAX, SYS_UID_MIN, or SYS_UID_MAX from
/etc/login.defs.
-U, --unlock
Unlock a user's password. This removes the '!' in front of the encrypted password. You can't use this
option with -p or -L.
Note: if you wish to unlock the account (not only access with a password), you should also set the
EXPIRE_DATE (for example to 99999, or to the EXPIRE value from /etc/default/useradd).
-v, --add-subuids FIRST-LAST
Add a range of subordinate uids to the user's account.
This option may be specified multiple times to add multiple ranges to a user's account.
No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from
/etc/login.defs.
-V, --del-subuids FIRST-LAST
Remove a range of subordinate uids from the user's account.
This option may be specified multiple times to remove multiple ranges to a user's account. When both
--del-subuids and --add-subuids are specified, the removal of all subordinate uid ranges happens
before any subordinate uid range is added.
No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from
/etc/login.defs.
-w, --add-subgids FIRST-LAST
Add a range of subordinate gids to the user's account.
This option may be specified multiple times to add multiple ranges to a user's account.
No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from
/etc/login.defs.
-W, --del-subgids FIRST-LAST
Remove a range of subordinate gids from the user's account.
This option may be specified multiple times to remove multiple ranges to a user's account. When both
--del-subgids and --add-subgids are specified, the removal of all subordinate gid ranges happens
before any subordinate gid range is added.
No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from
/etc/login.defs.
-Z, --selinux-user SEUSER
defines the SELinux user to be mapped with LOGIN. An empty string ("") will remove the respective
entry (if any). Note that the shadow system doesn't store the selinux-user, it uses semanage(8) for
that.
CAVEATS
You must make certain that the named user is not executing any processes when this command is being
executed if the user's numerical user ID, the user's name, or the user's home directory is being changed.
usermod checks this on Linux. On other operating systems it only uses utmp to check if the user is logged
in.
You must change the owner of any crontab files or at jobs manually.
您必须更改 NIS 服务器上的 NIS 相关内容。
配置文件
The following configuration variables in /etc/login.defs change the behavior of this tool:
文件
/etc/group Group account information /etc/gshadow Secure group account informatio. /etc/login.defs Shadow password suite configuration /etc/passwd User account information /etc/shadow Secure user account information /etc/subgid Per user subordinate group IDs /etc/subuid Per user subordinate user IDs
参见
chfn(1), chsh(1), passwd(1), crypt(3), gpasswd(8), groupadd(8), groupdel(8), groupmod(8), login.defs(5), subgid(5), subuid(5), useradd(8), userdel(8).