$ useradd
Usage: useradd [options] LOGIN
useradd -D
useradd -D [options]
Options:
-b, --base-dir BASE_DIR base directory for the home directory of the
new account
-c, --comment COMMENT GECOS field of the new account
-d, --home-dir HOME_DIR home directory of the new account
-D, --defaults print or change default useradd configuration
-e, --expiredate EXPIRE_DATE expiration date of the new account
-f, --inactive INACTIVE password inactivity period of the new account
-g, --gid GROUP name or ID of the primary group of the new
account
-G, --groups GROUPS list of supplementary groups of the new
account
-h, --help display this help message and exit
-k, --skel SKEL_DIR use this alternative skeleton directory
-K, --key KEY=VALUE override /etc/login.defs defaults
-l, --no-log-init do not add the user to the lastlog and
faillog databases
-m, --create-home create the user's home directory
-M, --no-create-home do not create the user's home directory
-N, --no-user-group do not create a group with the same name as
the user
-o, --non-unique allow to create users with duplicate
(non-unique) UID
-p, --password PASSWORD encrypted password of the new account
-r, --system create a system account
-R, --root CHROOT_DIR directory to chroot into
-s, --shell SHELL login shell of the new account
-u, --uid UID user ID of the new account
-U, --user-group create a group with the same name as the user
-Z, --selinux-user SEUSER use a specific SEUSER for the SELinux user mapping
$ sudo useradd -g group -s /bin/bash -m username #group表示用户组(例如:root，新建用户用户名:username)
$ sudo passwd username
Enter new UNIX password:
Retype new UNIX password:
给用户添加执行sudo命令权限，不添加权限执行时可能报错如下：
*** is not in the sudoers file.This incident will be reported.
$ su root
$ chmod u+x /etc/sudoers #添加sudo文件写权限
$ vim /etc/sudoers #在root ALL=(ALL) ALL下添加
root ALL=(ALL) ALL # 可参考下文补充说明
$ chmod u-w /etc/sudoers #撤销sudo文件写权限
youuser ALL=(ALL) ALL
%youuser ALL=(ALL) ALL
youuser ALL=(ALL) NOPASSWD:ALL
%youuser ALL=(ALL) NOPASSWD:ALL
第一行:允许用户youuser执行sudo命令(需要输入密码).
第二行:允许用户组youuser里面的用户执行sudo命令(需要输入密码).
第三行:允许用户youuser执行sudo命令,并且在执行的时候不输入密码.
第四行:允许用户组youuser里面的用户执行sudo命令,并且在执行的时候不输入密码.
