Provided by: passwd_4.8.1-2ubuntu2_amd64
usermod - 修改一个用户账户
usermod [选项] 登录
The usermod command modifies the system account files to reflect the changes that are specified on the command line.
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, --badnames Allow names that do not conform to standards. -c, --comment COMMENT The new value of the user's password file comment field. It 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. -e, --expiredate EXPIRE_DATE The date on which the user account will be disabled. The date is specified in the format YYYY-MM-DD. An empty EXPIRE_DATE argument will disable the expiration of the account. This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none. -f, --inactive INACTIVE 密码过期之后，账户被彻底禁用之前的天数。 0 表示密码过期时，立即禁用账户；-1 表示不使用这个功能。 This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none. -g, --gid GROUP 用户的新初始登录组的组名或数字代号。此组必须存在。 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。 -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 are subject to the same restrictions 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. 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 将用户的主目录移动到新位置。 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 When used with the -u option, this option allows to change the user ID to a non-unique value. -p, --password PASSWORD The encrypted password, as returned by crypt(3). Note: This option is not recommended 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, --root CHROOT_DIR Apply changes in the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory. -P, --prefix PREFIX_DIR Apply changes in the PREFIX_DIR directory and use the configuration files from the PREFIX_DIR directory. 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 用户的新登录 shell 的名称。将此字段设置为空会让系统选择默认的登录 shell。 -u, --uid UID 用户 ID 的新数值。 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。 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 users 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 users 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 users 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 users 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 用户登陆的 SELinux 用户。 A blank SEUSER will remove the SELinux user mapping for user LOGIN (if any).
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 platforms 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。
The following configuration variables in /etc/login.defs change the behavior of this tool:
/etc/group 组账户信息。 /etc/gshadow 安全组账户信息。 /etc/login.defs Shadow 密码套件配置。 /etc/passwd 用户账户信息。 /etc/shadow 安全用户账户信息。 /etc/subgid Per user subordinate group IDs. /etc/subuid Per user subordinate user IDs.