9 Useful Basic Unix Commands

Mario Gunawan
3 min readFeb 6, 2023

This article is targeted at people who are new to Unix & want to learn its most-used commands that are used in the terminal.

cd

cd ~/Projects

Unless you’re new to unix, I think everybody knows what this do. This commands will change your current terminal’s directory to another directory. For example, if you’re in a directory and you want to change to b directory, simply type cd b. More complete explanation: link.

ls

ls

This command will list what files/folders you have in your current directory. To also view all hidden files/folders, type ls -a .

mv

mv ./a.txt ./b.txt

This command can either move a file to another directory, or, like above, rename a file. The first argument (a.txt) is the file while the second argument is the new file name (in case of renaming) or the directory (in case of moving a file). To move to a directory (say, b directory), you can type mv a.txt b/ .

rm

rm ./a.txt

This command is used for removing a file. If you want to remove a folder, use rm -rf [folder_name] .

mkdir

mkdir app

This command is used to create a new directory. You can create nested directory by using mkdir -p a/b/c .

cat

cat ./a.txt

Unlike its names, cat is used to show the content of a file. There are more uses of this command, but you can learn as you go.

ps -e

ps -e

This command is used to list processes currently running on the machine. If this command doesn’t work, try calling sudo ps -e (you will learn more about sudo)

Mostly you only look at “PID” and “CMD” from the output.

output of ps-e

kill -9

kill -9 [PID]

Like its name, kill -9 is used to remove a running process. You can get the PID from the process above.

grep

[some_command] | grep search_value

Grep is used to filter out results of a command. I can type ls | grep Doc If I to get any file/folders in current directory that have “Doc” in it. grep can be used with many command, as long as you place it after the | character.

Combined with the ps -e command, we can search for a process that we want to kill

search for any line that have “figma” in it

For now, it’s enough to know the basic commands. Later on, if you found any difficulties, just google it.

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Mario Gunawan

I'm a passionate mobile / web developer. Writing articles about software development, mainly about flutter and react.