Introduction
In this article, you will learn about frequently used Linux commands with examples.
Linux Commands
List
1) Show all files and directories.
Syntax
ls
2) List out all files including hidden files.
Syntax
ls -a
3) List the files in 'long format', which contains lots of useful information (size, last modified).
Syntax
ls -l
4) List out the files with details (timestamp and access details).
Syntax
ls -l
Directory
1) Creating directory with all permissions (Read, write, and execute).
Syntax
mkdir -m 777 <directory_name>
Example
mkdir -m 777 sample_folder
2) Delete the directory.
Syntax
rmdir <directory_name>
Example
rmdir sample_folder
3) Rename the directory.
Syntax
mv <directory_name> <new_directory_name>
Example
mv sample_folder test_folder
4) To change the current directory location.
Syntax
cd <directory_name>
Example
cd sample_folder (Switch to a subdirectory (of the current directory) named sample_folder)
cd .. (Move to the parent directory of the current directory)
cd /home/sample_folder (Switch to a directory named /home/sample_folder)
5) Find all of the files in the directory and all of its subdirectories.
Syntax
find <directory_name> -name <file_name> -print
Example
find . -name myfile.txt -print (Find in the current directory and its subdirectories)
find sample_folder -name myfile.txt -print (Find in the "sample_folder" directory and its subdirectories)
Files
1) Creating the blank files.
Syntax
touch <file_name>
touch <file_name_1> <file_name_2> #For creating multiple blank files
Example
touch sample.txt or touch sample.txt text.txt
2) Create a new file using cat command.
Syntax
cat <file_name>
Example
cat new_test.txt
Note: Awaits input from the user, type desired text, and press CTRL+D (hold down Ctrl key and type ‘d‘) to exit.
3) Delete the file.
Syntax
rm <file_name>
Example
rm sample.txt (Deletes the file named "sample.txt")
rm sample.txt test.txt (Deletes two files – "sample.txt" and "test.txt")
rm new* (Deletes all files that begin with the prefix "new")
4) Move the file from one directory to another directory.
Syntax
mv <directory_name/file_name> <new_directory_name/file_name>
Example
mv sample_folder/sample.txt new_folder/sample.txt
5) Rename the file.
Syntax
mv <old_file_name> <new_file_name>
Example
mv sample.txt test.txt
6) Copy the existing file with the data.
Syntax
cp <source_file_name> <newe_file_name>
Example
cp sample.txt test.txt
7) Display the contents of the file in the terminal.
Syntax
cat <existing_file_name>
Example
cat test.txt (Display the contents of "test.txt" file)
cat sample.txt test.txt (Display the contents of two files "sample.txt" and "test.txt" on your terminal as one continuous display)
8) Change the permission of the file.
Syntax
chmod <permission> <existing_file_name>
Example
chmod 777 test.txt
9) Show the first 10 lines of text file.
Syntax
head <file_name>
Example
head test.txt
10) Show the last 10 lines of text file.
Syntax
tail <file_name>
Example
tail test.txt
File Compression
1) Compress the files.
Syntax
gzip <file_name>
Example
gzip test.txt
2) Uncompress files compressed by gzip.
Syntax
gunzip <file_name>
Example
gzip test.gz
Find
1) Search the given string in the files.
Syntax
grep <search_string> <file_name>
Example
grep "test" sample.txt
Clean
1) Clears all the clutter on the terminal and gives the clean window.
Syntax
clear
History
1) Show history of previous commands.
Syntax
history
Date
1) Display the current day, date, time, and year.
Syntax
date
2) Display the calendar of the current month.
Syntax
cal <month> <year>
Example
cal 12 2021 (Print calendar for December 2021)
Network
1) Show the IP address of the system.
Syntax
ip
2) Check if remote host is reachable via ICMP ping.
Syntax
ping
Process
1) List the processes.
Syntax
ps
2) Kill the processes.
Syntax
kill <process_id>
Example
kill 1234
Help
1) Display the how to use a particular command or want to find out all its options.
Syntax
man <command_name>
Example
man ls
About
1) To know about who is logged on, and where they're coming from.
Syntax
who
2) Display your username.
Syntax
whoami
3) To know about when the user last logged on and off and from where.
Syntax
last username
Hope you know about the list of Unix commands which are frequently used. Thank you.