File permissions of day02 operation

1. Create user tom,jack,zhuzhuxia;zhuzhuxia The user's additional group is tom

sudo useradd tom

sudo useradd jack

sudo useradd zhuzhuxia -G tom
2. Switch to user tom, stay /tmp Create files in directory tom.txt ( Observe the ownership and authority of the file )

su tom

cd /tmp

touch tom.txt

ll /tmp/tom.txt

3. take tom The permission of the created file is modified to rw-r----- 

 

Give first tom User command access

After use chmod Command to modify the permissions of the file

4. towards tom Write content in the created file "Tihs is tom file ,dont touch"

 5. Excuse me, : jack,zhuzhuxia Can you check the contents of the file ?

 Jack Belong to other users , Useless reading tom Permissions of files in users

zhuzhuxia and tom Is the same group of users , Can read tom Documents in

6. Create a directory /opt/test Catalog , The group of this directory is required to be it Group , Any user who creates files under this directory inherits the ownership of this directory Group ？

About chmod g+s

linux in g s How to use it in the document ,Linux Next chmod g+s 、chmod o+t 、chmod u+s Detailed explanation _Sahadhammika The blog of -CSDN Blog https://blog.csdn.net/weixin_28419039/article/details/116607781

 [[email protected] ~]# groupadd it
[[email protected] ~]# chmod 775 /opt/test
[[email protected] ~]# ll -d /opt/test/
drwxrwxr-x 3 root root 18 Jul  4 04:08 /opt/test/
[[email protected] ~]# chown .it /opt/test/
[[email protected] ~]# chmod g+s /opt/test/
[[email protected] ~]# su tom

[[email protected] root]$ sudo touch /opt/test/tom.txt
[sudo] password for tom: 
[[email protected] root]$ ll /opt/test/tom.txt
-rw-r--r-- 1 root it 0 Jul  5 08:44 /opt/test/tom.txt

[[email protected] root]$ sudo touch /opt/test/jack.txt
[[email protected] root]$ ll  /opt/test/jack.txt
-rw-r--r-- 1 root it 0 Jul  5 08:47 /opt/test/jack.txt

7. Use root Users create directories /prov, Change the owner to tom, Belongs to the group for tom, Permission is 750

Subject and group

The owner and group of the file _baizuo_1 The blog of -CSDN Blog _ Generic groups and owners Linux The ownership of files and directories. The ownership relationship of files or directories mainly defines the owner and group of the file . Example ：-rw-r--r-- 1 root root 0 Jan  7 21:29 testfile Express testfile The owner of the file is readable and writable , The generic group can read , Others can read .testfile The owner of root, The genus is root. Change the owner or group of a file and use the command chown Change the subject and group [[email protected]https://blog.csdn.net/baizuo_1/article/details/78998707 8. List /home/ All files below include hidden files ？

ls -a 

 9. Check out your ip Address

ifconfig  

or ip a

10.chown What is it used for ？chmod What is it used for ？

chown: Change the owner and group of the file or directory

chmod: Set access permissions for files or directories