A02_Common commands 1

Example 1:
1. Check the path after logging in to the system,

[root@localhost ~]# pwd

Then enter the /tmp/ directory,

[root@localhost ~]# cd /tmp

Create two directories test1 and test2,

[root@localhost tmp]# mkdir test1 test2

Create an empty file student in the test1 and test2 directories

[root@localhost tmp]# touch test1/student
[root@localhost tmp]# touch test2/student

2. Create a teacher's directory under the /home/ directory,

[root@localhost ~]# mkdir /home/teacher

Copy test1 to the teacher/ directory,

[root@localhost ~]# cp -r /tmp/test1 /home/teacher

Move test2 to the teacher/ directory;

[root@localhost ~]# mv /tmp/test2 /home/teacher

3. Go to the / directory and find the file named student in the system.

[root@localhost ~]# cd /
[root@localhost /]# find / -name "*student*"

4. Delete the test1 directory under /tmp/.

[root@localhost ~]# rm -rf /tmp/test1

5. Create a test file in the current user's home directory, and then create a soft link with the target pointing to /tmp.

[root@localhost ~]# touch test
[root@localhost ~]# ln -s /root/test /tmp

Example 2:
1. Create/Class Name Directory/My Directory,

[root@localhost ~]# mkdir -p /classname/myname

Enter your name directory and create empty files named 123 and abc in your directory.

[root@localhost ~]# cd /classname/myname
[root@localhost myname]# touch 123 abc

2. Copy my directory to the /tmp directory and list all the details of the /tmp directory

[root@localhost ~]# cp -r /classname/myname /tmp
[root@localhost ~]# ls -l /tmp

3. Find the 123 file in the / directory and save the result to the save file

[root@localhost ~]# find / -name "123" > save

4. Enter the self-built directory and delete all files in the directory

[root@localhost ~]# rm -rf /classname/myname/*

5. Move the class name directory to the /tmp directory and check whether it is successful

[root@localhost ~]# mv /classname /tmp
[root@localhost ~]# ls /tmp | grep classname

6. View the kernel information of the current linux system.

[root@localhost ~]# uname -a

7. Check the IP address information.

[root@localhost ~]# ifconfig ens33
或
[root@localhost ~]# ip addr

8. View memory information.

[root@localhost ~]# cat /proc/meminfo

9. Only count the disk space occupied by the /etc directory.

[root@localhost ~]# du -sh /etc

10. Copy the /etc/passwd file to /root

[root@localhost ~]# cp /etc/passwd /root

11. How many lines are in the statistics /root/passwd file?

[root@localhost ~]# wc -l /root/passwd

12. Use of vi (take /root/passwd as an example)

（1）显示行号
末行模式  <:set nu>

（2）行间跳转，如跳转到15行
末行模式 <:15>

（3）删除一个字符
命令模式 <x 或 del>

（4）一次性删除3行
命令模式 <3dd>

（5）一次性复制3行，粘贴到文件的末尾。
命令模式 <3yy>
命令模式 <G>
命令模式 <p>

（6）从上往下查看所有bin的字符
末行模式 <:bin>

（7）将整篇文档的所有bin替换为333
末行模式 <:% s/bin/333/g>

（8）将第3行到第5行的333替换为444
末行模式 <:3,5 s/333/444/g>

（9）保存并退出。
末行模式 <:wq>