Linux Commands for a Beginner

List of Linux commands for all the beginners

Linux Cheat Sheet

Creating a directory in Ubuntu OS 22.04 LTS named sample

mkdir sample

Changing path to the sample directory and creating a file named sample.txt

cd sample
touch sample.txt

Checking for the current path that we are on:

pwd

Checking the information on a file such as inodes, locations and symbolic links

stat sample.txt

Adding a user named user1 to the group called devops

useradd -a -G devops user1

Creating a softlink for a file named sample.txt

ln -s sample.txt sample_link_shortcut.txt

Lets Copy the file

cp sample.txt sample1.txt

Listing out the groups within the OS:

groups

List out the users present on the OS:

cat /etc/passwd

List out the files and folders along with their permissions and any hidden files:

ls -ahl

Find a file that is greater than 25MB:

find . -type f -size +25M 

List out the contents of a file:

cat sample.txt

List the contents of a file in the reverse order:

tac sample.txt

Find a pattern or a word that exists and in the file sample and replace it with another word

sed -i 's/tokan/token/g' sample.txt  #(the -i stands for --in-place tag)

Display contents of a file such as dnf.log present in the /var/log folder.

less /var/log/dnf.log

Display contents of a file such as dnf.log present in the /var/log folder.

more /var/log/dnf.log

Find pattern or a word within a file

grep -i 'centos' sample.txt (i is for ignore case)
grep -r 'centos' sample.txt (r is for recursive)

Deleting or removing a file:

rm sample.txt

Deleting or removing a folder with contents:

rm -rf sample  (To be very very careful when using during production)

The above command should be used carefully and only individuals who are authorized to access production should be given permissions, the results tend to be devastating otherwise.