0.Basic_Linux_Commands.md

Basic Linux Commands for DevOps

Use any Linux OS (Redhat/Ubuntu/Amazon)

File and Directory Management

Count	Command	Description
1.	cp	Copies files and directories
2.	pwd	Prints the current working directory
3.	cd	Changes current directory
4.	cd..	Changes to the parent directory
5.	cd -	Changes to previous directory
6.	cd ~	Changes to home directory
7.	ls	Lists contents of the current directory
8.	ls -l	Lists the files and directories in the current working directory in long format
9.	ls -a	List all files and directories including the hidden ones
10.	ls r	Lists files and directories in reverse
11.	mkdir	Creates a new directory
12.	rmdir	Removes an empty directory
13.	mv	Moves or renames a file or directory
14.	rm	Removes a file or directory
15.	rm -i	Prompts system confirmation before deleting
16.	rm -r	Deletes a file or directory recursively
17.	rm -d	Delete empty directories

File Manipulation

Count	Command	Description
18.	touch	Creates an empty file or modify timestamp
19.	cat	Concatenates and prints file contents
20.	cat -n	Displays the contents of a file along with line numbers
21.	tac	Concatenates and prints of a file in reverse order
22.	less	Shows contents in a scrollable manner
23.	head	Displays the first ten lines of a file
24.	tail	Displays the last ten lines of a file
25.	grep	Searches for a specifies pattern in one or more files
26.	nano	Edits and Creates files
27.	diff	Compares two text files
28.	sort	Sorts lines of a text file
29.	sort -r	Sorts file reversely
30.	sort -u	Removes duplicates and sorts unique values

Network Configuration

Count	Command	Description
31.	ifconfig	Displays network interface configuration information
32.	ifconfig -a	Displays all interfaces available even if those are down
33.	ifconfig -s	Displays short list of network interface
34.	ip address	Dieplays all IP addresses related with all network devices
35.	ip link	Shows all network interfaces available on the system
36.	nslookup	Queries the DNS server for information about a domain name or IP address
37.	curl	Facilitates the transfer of data to or from a server, using any of the protocols it supports

System and Process Management

Count	Command	Description
38.	sudo	Allows a user to run a command with the privileges of another user
39.	ps	Lists the running processes on a system
40.	kill	Terminates running processes on a system
41.	killall	Terminates all processes with a specified name
42.	df	Displays the amount of disk space used and available on a file system
43.	du	Estimate file space usage

User Management

Count	Command	Description
44.	useradd	Create a new user account
45.	userdel	Delete a user account
46.	passwd	Change a user's password
47.	groupadd	Add a new group to the system
48.	groupdel	Delete an existing group
49.	id	Dispaly the user and group IDs associated with the current user
50.	su	Switch to another user account

System Information

Count	Command	Description
51.	who	Displays information about currently logged-in user
52.	whoami	Displays the user name of the current user logged in
53.	uname	Displays information about the current system
54.	hostname	Displays or set the hostname of the current system
55.	hostnamectl	Queries or modifies the hostname and related settings of the current system
56.	date	Displays and sets system date and time
57.	history	Displays a list of previously executed commands in the terminal
58.	history -c	clears the history list of previously executed commands
59.	cal ncal	Displays the calendar of the current month
60.	df	Shows information about both total and available scape on a file system