Introduction:
In today's digital age, whether you're a student, professional, or simply someone who loves exploring the world of technology, a basic understanding of Linux commands can be an empowering skill. Don't be discouraged by the jargon or the tech-savvy image of Linux—these fundamental commands are accessible to everyone, regardless of their technical background.
Think of Linux commands as the keys to a powerful toolbox that can help you navigate, create, and manage files and directories on your computer. They provide you with a bridge to the inner workings of your operating system, allowing you to perform tasks, organize your digital life, and troubleshoot issues.
In this guide, we'll walk you through these essential Linux commands in a way that's friendly, approachable, and devoid of technical mystique. Whether you're a student looking to improve your computer skills, a professional seeking to streamline your work, or just someone curious about what makes Linux tick, this is the place to start.
1. Navigating the File System:
Present Working Directory (
pwd): This is like checking your current location on a map. It tells you where you are in your computer's file system.[root@sid-vm ~]# pwd /root [root@sid-vm ~]#List Files and Directories (
ls): Think of this as looking inside a folder to see what's in it. It shows you a list of all the files and folders in your current location.[root@sid-vm /]# ls bin boot data dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var [root@sid-vm /]#If you want to long list the files and directories to get the complete details, use "ls -l" command.
[root@sid-vm /]# ls -l total 32 lrwxrwxrwx. 1 root root 7 Jul 18 11:11 bin -> usr/bin dr-xr-xr-x. 4 root root 4096 Jul 19 04:32 boot drwxr-xr-x. 2 root root 6 Oct 29 04:55 data drwxr-xr-x. 21 root root 3320 Oct 31 07:06 dev drwxr-xr-x. 109 root root 8192 Oct 31 07:06 etc drwxr-xr-x. 2 root root 6 Apr 10 2018 home lrwxrwxrwx. 1 root root 7 Jul 18 11:11 lib -> usr/lib lrwxrwxrwx. 1 root root 9 Jul 18 11:11 lib64 -> usr/lib64 drwxr-xr-x. 2 root root 6 Apr 10 2018 media drwxr-xr-x. 2 root root 6 Apr 10 2018 mnt drwxr-xr-x. 3 root root 16 Jul 18 11:23 opt dr-xr-xr-x. 198 root root 0 Oct 31 07:06 proc dr-xr-x---. 5 root root 4096 Jul 19 04:30 root drwxr-xr-x. 34 root root 1140 Oct 31 07:06 run lrwxrwxrwx. 1 root root 8 Jul 18 11:11 sbin -> usr/sbin drwxr-xr-x. 2 root root 6 Apr 10 2018 srv dr-xr-xr-x. 13 root root 0 Oct 31 07:06 sys drwxrwxrwt. 8 root root 4096 Nov 5 04:27 tmp drwxr-xr-x. 13 root root 4096 Jul 18 11:11 usr drwxr-xr-x. 20 root root 4096 Jul 18 11:39 var [root@sid-vm /]#Change Directory (
cd): This is like moving from one room to another. It helps you go into different folders or locations.[root@sid-vm /]# pwd / [root@sid-vm /]# [root@sid-vm /]# ls bin boot data dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var [root@sid-vm /]# [root@sid-vm /]# [root@sid-vm /]# cd tmp/ [root@sid-vm tmp]# [root@sid-vm tmp]# pwd /tmp [root@sid-vm tmp]#
2. Creating and Managing Directories:
Make a New Directory (
mkdir): Creating a directory is like making a new folder to store your stuff. You give it a name, and it appears in your current location.[root@sid-vm tmp]# ls [root@sid-vm tmp]# [root@sid-vm tmp]# mkdir testdir [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 0 drwxr-xr-x. 2 root root 6 Nov 5 04:30 testdir [root@sid-vm tmp]#Create Nested Directories (
mkdir -p): Nested directories are like having folders inside folders. This command helps you create folders within other folders.[root@sid-vm tmp]# mkdir -p dev/test/deploy [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 0 drwxr-xr-x. 3 root root 18 Nov 5 04:31 dev [root@sid-vm tmp]# cd dev/ [root@sid-vm dev]# ls -l total 0 drwxr-xr-x. 3 root root 20 Nov 5 04:31 test [root@sid-vm dev]# [root@sid-vm dev]# cd test/ [root@sid-vm test]# ls -l total 0 drwxr-xr-x. 2 root root 6 Nov 5 04:31 deploy [root@sid-vm test]#
3. Creating and Viewing Files:
Create an Empty File (
touch): Think of this as creating a blank piece of paper. You can give it a name, and it's ready for you to write on.[root@sid-vm tmp]# touch test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 0 -rw-r--r--. 1 root root 0 Nov 5 04:33 test.txt [root@sid-vm tmp]#Display File Contents (
cat): This command lets you open and read what's written on a piece of paper (a file). It displays the text inside the file.[root@sid-vm tmp]# cat test.txt Hello, You are reading Siddhartha technical blogs!! [root@sid-vm tmp]#Add Content to a File (
echo): Imagine typing or writing on that piece of paper.echoallows you to add text to a file.[root@sid-vm tmp]# echo "I am ready to learn Linux. Are you ready?" > abc.txt [root@sid-vm tmp]# [root@sid-vm tmp]# cat abc.txt I am ready to learn Linux. Are you ready? [root@sid-vm tmp]#
4. Managing Permissions:
We will cover this topic in a separate blog, but for now, we will understand what command we can use to manage permissions in Linux.
Modify File and Directory Permissions (
chmod): Permissions are like locks on a door.chmodhelps you control who can open the door (access files and folders).[root@sid-vm tmp]# ls -l total 4 -rw-r--r--. 1 root root 52 Nov 5 04:34 test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# [root@sid-vm tmp]# chmod 775 test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 4 -rwxrwxr-x. 1 root root 52 Nov 5 04:34 test.txt [root@sid-vm tmp]#Change File and Directory Ownership (
chown): It's like changing the owner of a house. You can transfer ownership of files and folders to someone else.[root@sid-vm tmp]# ls -l total 4 -rwxrwxr-x. 1 root root 52 Nov 5 04:34 test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# chown labuser test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 4 -rwxrwxr-x. 1 labuser root 52 Nov 5 04:34 test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 4 -rwxrwxr-x. 1 labuser root 52 Nov 5 04:34 test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# chgrp labuser test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# ls -l total 4 -rwxrwxr-x. 1 labuser labuser 52 Nov 5 04:34 test.txt [root@sid-vm tmp]#
5. Deleting Files and Directories:
Remove Files and Directories (
rm): This is like throwing away a piece of paper or an empty folder. It deletes files and folders.[root@sid-vm tmp]# ls test.txt [root@sid-vm tmp]# [root@sid-vm tmp]# rm test.txt rm: remove regular file ‘test.txt’? yes [root@sid-vm tmp]#Delete Empty Directories (
rmdir): Use this when you want to throw away an empty folder.[root@sid-vm tmp]# ls -l total 0 drwxr-xr-x. 2 root root 6 Nov 5 04:42 testdir [root@sid-vm tmp]# [root@sid-vm tmp]# cd testdir/ [root@sid-vm testdir]# ls [root@sid-vm testdir]# cd . [root@sid-vm testdir]# cd .. [root@sid-vm tmp]# [root@sid-vm tmp]# rm testdir/ rm: cannot remove ‘testdir/’: Is a directory [root@sid-vm tmp]# rm -rf testdir/ [root@sid-vm tmp]#Forcefully Remove Files and Directories (
rm -rf): Be careful with this! It's like using a super strong delete button. It can remove everything, so use it with caution.
6. Viewing and Editing Files:
Display File Contents (
cat): This is like reading the text on a piece of paper.Basic Text Editing (
nanoorvim): Think of this as being able to write and edit on that piece of paper.nanoorvimare like simple word processors.[root@sid-vm tmp]# vim hello.txt Hello friends, Linux Seekh lo... ~ ~ ~ ~ ~ ~ :wq [root@sid-vm tmp]# cat hello.txt Hello friends, Linux Seekh lo... [root@sid-vm tmp]#
7. Viewing the Beginning and End of Files:
Display the Start of a File (
head): It's like reading the first few lines of a book.(by default it will show top 10 lines)
[root@sid-vm tmp]# head exam-poem.txt Today we got the first pop quiz I could actually do! Usually when we take a test I haven’t got a clue. The first question was easy: Find a booger in your nose. Then wipe it on the paper instead of on your clothes. [root@sid-vm tmp]#Show the End of a File (
tail): This is like reading the last few lines of a book.(by default it will show bottom 10 lines)
[root@sid-vm tmp]# tail exam-poem.txt The first question was easy: Find a booger in your nose. Then wipe it on the paper instead of on your clothes. I had to list ten chocolate bars and nine video games. Then I had to come up with a dozen crazy claims. [root@sid-vm tmp]#
8. Comparing Two Files:
Find Differences Between Two Files (
diff): Imagine having two different drafts of an essay.diffhelps you identify the changes between them.[root@sid-vm tmp]# cat fruits.txt Apple Mango Banana Cherry Kiwi Orange Guava [root@sid-vm tmp]# [root@sid-vm tmp]# cat colors.txt Red Pink White Black Blue Orange Purple Grey [root@sid-vm tmp]# [root@sid-vm tmp]# diff fruits.txt colors.txt 1,5c1,5 < Apple < Mango < Banana < Cherry < Kiwi --- > Red > Pink > White > Black > Blue 7c7,8 < Guava --- > Purple > Grey [root@sid-vm tmp]#
Remember, you don't need to be a tech expert to use these commands. They are like simple tools to help you manage and work with files and folders on your computer. Just practice and take your time, and you'll become more comfortable with them.