linux and common basic operation command (2)
the second part is mainly related to the concept of users and groups, as well as some operations. A total of three files related to users and groups, are stored in / etc / shadow (password information) / etc / group (group information) / etc / passwd (user information)
1: commonly used commands have useradd, groupadd, usermod, userdel
##用户及组的创建
[root@linux_basis ~]# groupadd -g 966 nginx #添加组
[root@linux_basis ~]# useradd -u 998 -g 966 -s /sbin/nologin -d /opt/nginx nginx #添加进程，不加-s /sbin/nologin便是添加用户
[root@linux_basis ~]# id nginx
uid=998(nginx) gid=966(nginx) 组=966(nginx)
[root@linux_basis ~]# tail -1 /etc/passwd
nginx:x:998:966::/opt/nginx:/sbin/nologin
[root@linux_basis ~]# tail -1 /etc/shadow
nginx:!!:17989:0:99999:7:::
[root@linux_basis ~]# tail -1 /etc/group
nginx:x:966:
##设置用户密码
[root@linux_basis ~]# passwd nginx
Changing password for user nginx.
New password:
BAD PASSWORD: The password is shorter than 8 characters
Retype new password:
passwd: all authentication tokens updated successfully.
##无交互设置密码
useradd -u 994 test
echo "123456" | passwd --stdin test
##用户及组的修改
[root@linux_basis ~]# usermod -u 988 -s /bin/bash nginx
[root@linux_basis ~]# groupmod -g 666 nginx
[root@linux_basis ~]# id nginx
uid=988(nginx) gid=666(nginx) 组=666(nginx)
[root@linux_basis ~]# tail -1 /etc/passwd
nginx:x:988:666::/opt/nginx:/bin/bash
[root@linux_basis ~]# tail -1 /etc/shadow
nginx::17989:0:99999:7:::
[root@linux_basis ~]# tail -1 /etc/group
nginx:x:666:
##切换用户
[root@linux_basis ~]# su - nginx
[nginx@linux_basis ~]$ exit
logout
[root@linux_basis ~]#
##用户及组的删除
[root@linux_basis ~]# userdel -r nginx
[root@linux_basis ~]# groupdel nginx
groupdel：“nginx”组不存在 #(因为被userdel -r nginx删掉了)
##长模式查看文件及目录获取其信息
[root@linux_basis ~]# touch /mnt/linux_file_001.txt
[root@linux_basis ~]# ls -l /mnt/linux_file_001.txt
-rw-r--r--. 1 root root 27 Apr 4 07:11 /mnt/linux_file_001.txt
[root@linux_basis ~]#
[root@linux_basis ~]# mkdir /mnt/linux_dir_001
[root@linux_basis ~]# ls -ld /mnt/linux_dir_001
drwxr-xr-x 2 root root 6 Apr 4 07:11 /mnt/linux_dir_001
##文件基本权限修改之读写执行
[root@linux_basis ~]# ls -l /mnt/linux_file_001.txt
-rw-r--r--. 1 root root 27 Apr 4 07:11 /mnt/linux_file_001.txt
[root@linux_basis ~]# chmod u+x,g+w,o-r /mnt/linux_file_001.txt
[root@linux_basis ~]# ls -l /mnt/linux_file_001.txt
-rwxrw----. 1 root root 27 Apr 4 07:11 /mnt/linux_file_001.txt
##文件基本权限修改之拥有者和所属组
[root@linux_basis ~]# ls -l /mnt/linux_file_001.txt
-rwxrw----. 1 root root 27 Apr 4 07:11 /mnt/linux_file_001.txt
[root@linux_basis ~]# chown nginx:nginx /mnt/linux_file_001.txt
[root@linux_basis ~]# ls -l /mnt/linux_file_001.txt
-rwxrw----. 1 nginx nginx 27 Apr 4 07:11 /mnt/linux_file_001.txt
##批量修改
[root@linux_basis ~]# touch /mnt/linux_dir_001/file{001..100}
[root@linux_basis ~]# ls -l /mnt/linux_dir_001/file007
-rw-r--r-- 1 root root 0 Apr 4 07:26 /mnt/linux_dir_001/file007
[root@linux_basis ~]# chown -R nginx:nginx /mnt/linux_dir_001/
[root@linux_basis ~]# ls -l /mnt/linux_dir_001/file007
-rw-r--r-- 1 nginx nginx 0 Apr 4 07:26 /mnt/linux_dir_001/file007
##sudo
[root@system_manager ~]# useradd -G wheel bavduer # 在创建用户的时候加入wheel
[root@system_manager ~]# usermod -aG wheel bavduer # 在创建用户之后,追加wheel
[root@system_manager ~]# id bavduer
uid=1004(bavduer) gid=1004(bavduer) 组=1004(bavduer),10(wheel)
[root@system_manager ~]# passwd bavduer
更改用户 bavduer 的密码 。
新的 密码：
无效的密码： 密码是一个回文
重新输入新的 密码：
passwd：所有的身份验证令牌已经成功更新。
[root@system_manager ~]# vim /etc/sudoers.d/bavduer ---免密操作
bavduer ALL=(ALL) NOPASSWD: ALL
##sudo使用
[root@system_manager ~]# su - bavduer
[bavduer@system_manager ~]$ touch /opt/file999
touch: cannot touch ‘/opt/file999’: Permission denied
[bavduer@system_manager ~]$ sudo touch /opt/file999