如何在centos下创建新用户名和密码

[root@localhost ~]# adduser prefma

[root@localhost~]# passwd prefma
Changing password for user prefma.
New password:             # 输入密码
Retype new password:      # 再次输入密码
passwd: all authentication tokens updated successfully.

1 [root@localhost~]# whereis sudoers                     # 查找sudoers文件路径
2 sudoers: /etc/sudoers /etc/sudoers.d /usr/share/man/man5/sudoers.5.gz
3 [root@localhost~]# ls -l /etc/sudoers                  # 查看权限
4 -r--r----- 1 root root 3938 Sep  6  2017 /etc/sudoers  # 只有读权限
5 [root@localhost~]# chmod -v u+w /etc/sudoers           # 赋予读写权限
6 mode of ‘/etc/sudoers’ changed from 0440 (r--r-----) to 0640 (rw-r-----)

## Allow root to run any commands anywhere
root ALL=(ALL) ALL
prefma ALL=(ALL) ALL #这个是新用户

[root@localhost~]# chmod -v u-w /etc/sudoers
mode of ‘/etc/sudoers’ changed from 0640 (rw-r-----) to 0440 (r--r-----)

[prefma@localhost~]$ pwd
/home/prefma
[prefma@localhost~]$ ls -l /etc/sudoers
-r--r----- 1 root root 3995 Oct 16 22:42 /etc/sudoers