newusers - 批量更新和创建新用户
newusers [选项] [文件]
The newusers command reads a file (or the standard input by default) and uses this information to update a set of existing users or to create new users. Each line is in the same format as the standard password file (see passwd(5)) with the exceptions explained below:
It can be the name of a new user or the name of an existing user (or a user created before by newusers). In case of an existing user, the user's information will be changed, otherwise a new user will be created.
If the field is empty, a new (unused) UID will be defined automatically by newusers.
If this field contains the name of an existing user (or the name of a user created before by newusers), the UID of the specified user will be used.
If this field contains the name of an existing group (or a group created before by newusers), the GID of this group will be used as the primary group ID for the user.
如果此字段是一个数字，此数字会被用作此用户的主组 ID。如果没有对应此 GID 的现有组，将会使用此 GID 创建一个新组，名称和用户名相同。
If this field is empty, a new group will be created with the name of the user and a GID will be automatically defined by newusers to be used as the primary group ID for the user and as the GID for the new group.
If this field contains the name of a group which does not exist (and was not created before by newusers), a new group will be created with the specified name and a GID will be automatically defined by newusers to be used as the primary group ID for the user and GID for the new group.
If the home directory of an existing user is changed, newusers does not move or copy the content of the old directory to the new location. This should be done manually.
newusers first tries to create or change all the specified users, and then write these changes to the user or group databases. If an error occurs (except in the final writes to the databases), no changes are committed to the databases.
During this first pass, users are created with a locked password (and passwords are not changed for the users which are not created). A second pass is used to update the passwords using PAM. Failures to update a password are reported, but will not stop the other password updates.
The options which apply to the newusers command are:
System users will be created with no aging information in /etc/shadow, and their numeric identifiers are chosen in the SYS_UID_MIN-SYS_UID_MAX range, defined in login.defs, instead of UID_MIN-UID_MAX (and their GID counterparts for the creation of groups).
-R, --root CHROOT_DIR
The following configuration variables in /etc/login.defs change the behavior of this tool:
GID_MAX (number), GID_MIN (number)
The default value for GID_MIN (resp. GID_MAX) is 1000 (resp. 60000).
useradd and newusers use this to set the mode of the home directory they create.
此功能(分割组)允许限制组文件中的行长度。这对于确保 NIS 组的行比长于 1024 字符。
注意：分割组可能不受所有工具的支持(甚至在 Shadow 工具集中)。您不应该使用这个变量，除非真的需要。
SUB_GID_MIN (number), SUB_GID_MAX (number), SUB_GID_COUNT (number)
The default values for SUB_GID_MIN, SUB_GID_MAX, SUB_GID_COUNT are respectively 100000, 600100000 and 65536.
SUB_UID_MIN (number), SUB_UID_MAX (number), SUB_UID_COUNT (number)
The default values for SUB_UID_MIN, SUB_UID_MAX, SUB_UID_COUNT are respectively 100000, 600100000 and 65536.
SYS_GID_MAX (number), SYS_GID_MIN (number)
The default value for SYS_GID_MIN (resp. SYS_GID_MAX) is 101 (resp. GID_MIN-1).
SYS_UID_MAX (number), SYS_UID_MIN (number)
The default value for SYS_UID_MIN (resp. SYS_UID_MAX) is 101 (resp. UID_MIN-1).
UID_MAX (number), UID_MIN (number)
The default value for UID_MIN (resp. UID_MAX) is 1000 (resp. 60000).
useradd and newusers use this mask to set the mode of the home directory they create if HOME_MODE is not set.
It is also used by pam_umask as the default umask value.