1. What is the command to move a file or folder
mv
2. What is the command parameter to copy the file or folder
cp
3. Command parameters for forced deletion of files
rm -r
4. Command parameters to force delete a folder
rm -rf
5. Is it possible to execute rm -rf / on production
can not
6. Switch the command parameters of the user to execute the environment variable file and enter the home directory
su - xxx
7. Ordinary users want to temporarily obtain the maximum authority of root, which file to modify
/etc/sudoers
8. View command help
--help or man xxx
9. View history commands and execute 55 lines
history ！55
10. Create an empty file command
touch xxx
11. Commands to create folders
mkdir
12. What are the parameters for creating a cascaded folder
mkdir -p
13. Commands to view processes running in the background
ps -ef
14. Kill a process
kill -9 pid
15. View the port number command of the process 955
netatat -nlp | grep 955
16. How to set up a temporary alias
alias
17. Set the variable key=value, is this right?
No, no spaces
18. The environment variable files are divided into global and personal, so where are they located and how do they take effect?
Global: /etc/profile Execute source /etc/profile to take effect
Personal: ~/.bash_profile or ~/.bashrc Execute source ~/.bash_profile to take effect
19. What are the commands to view the contents of the file
cat
more
less
tail
20. What do hidden files start with
.
21. What is the difference between tail -f and -F
tail -f is equivalent to --follow=descriptor, track by file descriptor, stop tracking when a file is renamed or deleted
tail -F is equivalent to --follow=name --retry, track by file name, and keep repeating Try, that is, after the file is deleted or renamed, if the same file name is created again, it will continue to track
22. If a certain xxx wants to kill all processes related to xxx, what should we do in the first step? How should we do in the second step?
The first step ps -ef|grep xxx view
the second kill -9 pid kill
23. Create a user command
useradd
24. The command to create a user group
groupadd
25. What are the configuration files of users and user groups?
/etc/passwd
/etc/group
26. Generally check the user's situation and use the id ruoze, then how to add the bigdata user group to ruoze
usermod -a -G bigdata ruoze
27. Command to set password
passwd xxx
28. What is the symbol of the pipe character?
|
29. View the IP command of the current machine (Linux)
ifconfig
30. Talk about vi, how to edit the input content of a file, then save and exit
i -- enter edit mode
esc -- quit editing
: wq -- save and exit