Below we will see some of the important commands in Linux
System Based Commands

• #uname Displays Linux system information
• #uname -rDisplays kernel release information_
• #uptimeDisplays how long the system has been running
• #hostnameShows the system hostname
• #hostname -iDisplays the IP address of the system
• #last rebootShows system reboot history
• #dateDisplays current system date and time
• #whoamiDisplays who you are logged in as
• #finger usernameDisplays information about the user

Hardware Based Command

• #lshw Displays information about system's hardware configuration
• #lsblkDisplays block devices related information
• #free -mDisplays free and used memory in the system (-m indicates memory in MB)

Users Management Commands

• #idDisplays the details of the active user e.g. uid, gid, and groups
• #lastShows the last logins in the system
• #whoShows who is logged in to the system
• #groupadd "pink"Adds the group ‘pink’
• #adduser "rajni"Adds user ‘rajni’
• #userdel "rajni"Deletes user ‘rajni’
• #usermodUsed for modifying user information_

File Commands

• #ls -alLists files - both regular & hidden files and their permissions
• #pwdDisplays the present working directory path
• mkdir 'pink'Creates a new directory named ‘pink’
• #rm file_nameRemoves a file
• #rm -f filenameForcefully removes a file
• #rm -r directory_nameRemoves a directory recursively
• #rm -rf directory_nameRemoves a directory forcefully and recursively
• #cp file1 file2Copies the contents of file1 to file2
• #cp -r dir1 dir2Recursively Copies dir1 to dir2. dir2 is created if it does not exist
• #mv file1 file2Renames file1 to file2
• #ln -s /path/to/file_name link_nameCreates a symbolic link to file_name
• #touch file_nameCreates a new file
• #cat > file_namePlaces standard input into a file
• #more file_nameOutputs the contents of a file
• #head file_nameDisplays the first 10 lines of a file
• #tail file_nameDisplays the last 10 lines of a file
• #gpg -c file_nameEncrypts a file
• #gpg file_name.gpgDecrypts a file
• #wcPrints the number of bytes, words and lines in a file
• #xargsExecutes commands from standard input

Process Related Commands

• #psDisplay currently active processes
• #ps aux | grep 'telnet'Searches for the id of the process 'telnet'
• #pmapDisplays memory map of processes
• #top Displays all running processes
• #kill pidTerminates process with a given pid
• #killall procKills / Terminates all processes named proc
• #pkill process-nameSends a signal to a process with its name
• #bgResumes suspended jobs in the background
• #fgBrings suspended jobs to the foreground
• #lsofLists files that are open by processes

File Permission Commands

• #chmod octal filename -> Change file permissions of the file to octal Example
• #chmod 777 peep.txtSet rwx permissions to owner, group and everyone
• #chmod 755 peep.txt Set rwx to the owner and r_x to group and everyone
• #chmod 766 peep.txt Sets rwx for owner, rw for group and everyone
• #chown owner user-file Change ownership of the file
• #chown owner-user:owner-group file_name Change owner and group owner of the file
• #chown owner-user:owner-group directory Change owner and group owner of the directory

Network Commands

• #ip addr show Displays IP addresses and all the network interfaces
• #ip address add 192.160.0.1/24 dev eth0 Assigns IP address 192.168.0.1 to interface eth0
• #ifconfig Displays IP addresses of all network interfaces
• #ping host ping command sends an ICMP echo request to establish a connection to server
• #whois domain Retrieves more information about a domain name
• #dig domain Retrieves DNS information about the domain
• #host google.com Performs an IP lookup for the domain name
• #hostname -i Displays local IP address
• #wget file_name Downloads a file from an online source
• #netstat -pnltu Displays all active listening ports

Compression/Archives Commands

• #tar -cf peep.tar peep<:code>Creates archive file called 'peep.tar' from file 'peep'
• #tar -xf peep.tar Extract archive file 'peep.tar'
• #tar -zcvf peep.tar.gz source-folder Creates gzipped tar archive file from the source folder
• #gzip file Compression a file with .gz extension

Install Packages Commands

• #rpm -i pkg_name.rpm Install an rpm package
• #rpm -e pkg_name Removes an rpm package
• #dnf install pkg_nameInstall package using dnf utility

What is DNF utility?
DNF - The Next Generation Package Management Utility for RPM Based Distributions
A recent news draw the attention of many Linux users, professionals and learners that " DNF" (stands for nothing…
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Search Commands

• #grep 'pattern' files Search for a given pattern in files
• #grep -r pattern dir Search recursively for a pattern in a given directory
• #locate file Find all instances of the file
• #find /home/ -name "index" Find file names that begin with 'index' in /home folder
• #find /home -size +10000kFind files greater than 10000k in the home folder

File Transfer Commands

• #scp file1.txt server2/tmp Securely copy file1.txt to server2 in /tmp directory
• #rsync -a /home/apps /backup/ Synchronize contents in /home/apps directory with /backup directory

Disk Usage Commands

• #df -h Displays free space on mounted systems
• #df -i Displays free inodes on filesystems
• #fdisk -l Shows disk partitions, sizes, and types
• #du -sh Displays disk usage in the current directory in a human-readable format
• #findmnt Displays target mount point for all filesystems
• #mount device-path mount-pointMount a device

Directory Traverse Commands

• #cd .. Move up one level in the directory tree structure
• #cd Change directory to $HOME directory
• #cd /test Change directory to /test directory

Thanks for reading✨
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_Rajani ✨