In part 1 , we have covered first 12 commands.
13. grep command
Another basic Linux command that is undoubtedly helpful for everyday use is grep. It lets you search through all the text in a given file.
To illustrate, grep blue notepad.txt will search for the word blue in the notepad file. Lines that contain the searched word will be displayed fully.
14. sudo command
Short for “SuperUser Do”, this command enables you to perform tasks that require administrative or root permissions. However, it is not advisable to use this command for daily use because it might be easy for an error to occur if you did something wrong.
15. df command
Use df command to get a report on the system’s disk space usage, shown in percentage and KBs. If you want to see the report in megabytes, type df -m.
16. du command
If you want to check how much space a file or a directory takes, the du (Disk Usage) command is the answer. However, the disk usage summary will show disk block numbers instead of the usual size format. If you want to see it in bytes, kilobytes, and megabytes, add the -h argument to the command line.
17. head command
The head command is used to view the first few lines of any text file. By default, it will show the first ten lines, but you can change this number to your liking. For example, if you only want to show the first five lines, type head -n 5 filename.ext.
18. tail command
This one has a similar function to the head command, but instead of showing the first lines, the tail command will display the last ten lines of a text file. For example, tail -n filename.ext.
19. diff command
Short for difference, the diff command compares the contents of two files line by line. After analyzing the files, it will output the lines that do not match. Programmers often use this command when they need to make program alterations instead of rewriting the entire source code.
The simplest form of this command is diff file1.ext file2.ext.
20. tar command
The tar command is the most used command to archive multiple files into a tarball — a common Linux file format that is similar to zip format, with compression being optional.
This command is quite complex with a long list of functions such as adding new files into an existing archive, listing the content of an archive, extracting the content from an archive, and many more.
21. chmod command
chmod is another Linux command, used to change the read, write, and execute permissions of files and directories. As this command is rather complicated, you can read the full tutorial in order to execute it properly.
22. chown command
In Linux, all files are owned by a specific user. The chown command enables you to change or transfer the ownership of a file to the specified username. For instance, chown linuxuser2 file.ext will make linuxuser2 as the owner of the file.ext.
23. jobs command
jobs command will display all current jobs along with their statuses. A job is basically a process that is started by the shell.
24. kill command
If you have an unresponsive program, you can terminate it manually by using the kill command. It will send a certain signal to the misbehaving app and instructs the app to terminate itself.
There is a total of sixty-four signals that you can use, but people usually only use two signals:
- SIGTERM (15) — requests a program to stop running and gives it some time to save all of its progress. If you don’t specify the signal when entering the kill command, this signal will be used.
- SIGKILL (9) — forces programs to stop immediately. Unsaved progress will be lost.
Besides knowing the signals, you also need to know the process identification number (PID) of the program you want to kill. If you don’t know the PID, simply run the command ps ux.
After knowing what signal you want to use and the PID of the program, enter the following syntax:
kill [signal option] PID.
25. ping command
Use the ping command to check your connectivity status to a server. For example, by simply entering ping google.com, the command will check whether you’re able to connect to Google and also measure the response time.
26. wget command
The Linux command line is super useful — you can even download files from the internet with the help of the wget command. To do so, simply type wget followed by the download link.
27. uname command
The uname command, short for Unix Name, will print detailed information about your Linux system like the machine name, operating system, kernel, and so on.
28. top command
As a terminal equivalent to Task Manager in Windows, the top command will display a list of running processes and how much CPU each process uses.
29. history command
When you’ve been using Linux for a certain period of time, you’ll quickly notice that you can run hundreds of commands every day. As such, running history command is particularly useful if you want to review the commands you’ve entered before.
30. man command
Confused about the function of certain Linux commands? Don’t worry, you can easily learn how to use them right from Linux’s shell by using the man command. For instance, entering man tail will show the manual instruction of the tail command.
31. echo command
This command is used to move some data into a file. For example, if you want to add the text, “Hello, my name is John” into a file called name.txt, you would type echo Hello, my name is John >> name.txt
32. zip, unzip command
Use the zip command to compress your files into a zip archive, and use the unzip command to extract the zipped files from a zip archive.
33. hostname command
If you want to know the name of your host/network simply type hostname. Adding a -i to the end will display the IP address of your network.
34. useradd, userdel command
Since Linux is a multi-user system, this means more than one person can interact with the same system at the same time. useradd is used to create a new user, while passwd is adding a password to that user’s account. To add a new person named John type, useradd John and then to add his password type, passwd 123456789.
To remove a user is very similar to adding a new user. To delete the users account type, userdel UserName
Bonus Tips and Tricks
Use the clear command to clean out the terminal if it is getting cluttered with too many past commands.
Try the TAB button to autofill what you are typing. For example, if you need to type Documents, begin to type a command (let’s go with cd Docu, then hit the TAB key) and the terminal will fill in the rest, showing you cd Documents.
Ctrl+C and Ctrl+Z are used to stop any command that is currently working. Ctrl+C will stop and terminate the command, while Ctrl+Z will simply pause the command.
If you accidental freeze your terminal by using Ctrl+S, simply undo this with the unfreeze Ctrl+Q.
Ctrl+A moves you to the beginning of the line while Ctrl+E moves you to the end.
You can run multiple commands in one single command by using the “;” to separate them. For example Command1; Command2; Command3. Or use && if you only want the next command to run when the first one is successful.
To Sum Up
Basic Linux commands help users execute tasks easily and effectively. It might take a while to remember some of the basic commands, but nothing is impossible with lots of practice.
In the end, knowing and mastering these basic Linux commands will be undoubtedly beneficial for you.
Good luck!
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