Table Of Contents :
Linux commands
Here I have listed basic linux commands that are used in day to day life. The commands are divided into 7 parts, basic linux commands, process commands, user management commands, hardware commands, network commands, system information commands, file permission commands.
Some basic Linux commands
| Commands | Description |
|---|---|
ls | List all files in the present working directory |
ls -R | List files in sub-directories as well |
ls -a | List hidden files |
ls -al | List al files with detailed information like permission, size, owners etc. |
cd or cd ~ | Navigates to the HOME directory |
cd - | Navigates to previous directory |
cd / | Moves to root directory |
cat > filename | creates the new file |
touch filename | creates a new file |
cat file1 file2 file3 > file4 | joins two or more files and stores the output in a new file |
Process commands
| Commands | Description |
|---|---|
bg | To send a process to the background |
fg | To run a stopped process in the background |
top | Details of all active process |
ps | Give the status os preocesses of a user |
ps PID | Give the status of particular process |
kill PID | Kill a process |
nice | Start a process with a given priority |
df | Gives free hard disk space on your system |
free | Give free RAM on your system |
User Management commands
| Commands | Description |
|---|---|
sudo adduser username | To add a new user to your current linux machine |
sudo userdel -r “username” | deluser removes a user from a specific group |
Hardware commands
| Commands | Description |
|---|---|
dmesg | Displays |
cat /proc/cpuinfo | Display more infoprmation about CPU |
cat /proc/meminfo | Display more information about hardware memory |
lsusb | Display information about USB devices |
lsblk | Display block devices related information |
free -m | Displays free and used memory in the system |
lspci -tv | Dislpays PCI devices in a tree like diagram |
lsusb -tv | Dislpays USB devices in a tree like diagram |
dmidecode | Display hardware information from the BIOS |
Network commands
| Commands | Description |
|---|---|
whois domain | Retrives more information about a domain name |
dig domain | retrives DNS information about a domain name |
dig -x host | Performs reverse lookup on a domain |
host google.com | Performs a IP lookup for a domain name |
hostname -I | Display local IP address |
wget filename | Download a field from online source |
netstat -pnltu | Display all active listining ports |
quit | logout |
System information commands
| Commands | Description |
|---|---|
time | It is a utility to measure the time taken by a programe to execute |
/proc | The files under /proc displays system infromation |
df | Displays the information about the space on the mounted file-system |
who | Displays informationa bout the logged in user including their login time |
users | Prints the name of the currently logged in user |
last | This command displays the time of the logged-out users. |
lastlog | Displays a list of the users and the time/day of their login |
whoami | It displays the username of the logged in user |
free | Displays memory status |
uptime | It is used to display the how long the computer has been up and running |
File permissions commands
| Commands | Description |
|---|---|
ls -l | To show file type and access permissions |
chown -hR root /u | Change the owner of /u and subfiles to "root" |
chown root /u | Change the owner of /u to "root" |
chown root:staff /u | Likewise, but also change its group to "staff" |
chmod +x filename | To make a programme executable |
