Navigation Commands
| No. | Command | Description |
|---|
| 1 | cd | Change directory |
| 2 | pwd | Print working directory |
| 3 | ls | List directory contents |
| 4 | cd .. | Change to parent directory |
| 5 | cd ~ | Go to home directory |
File Management Commands
| No. | Command | Description |
|---|
| 6 | mkdir | Make directory |
| 7 | rmdir | Remove directory |
| 8 | cp | Copy files or directories |
| 9 | mv | Move or rename files or directories |
| 10 | rm | Remove files or directories |
File Inspection Commands
| No. | Command | Description |
|---|
| 11 | cat | Concatenate and print files |
| 12 | head | Print the first few lines of a file |
| 13 | tail | Print the last few lines of a file |
| 14 | less | View files page by page |
| 15 | more | View files one page at a time |
Text Processing Commands
| No. | Command | Description |
|---|
| 16 | grep | Search for patterns in files |
| 17 | sed | Stream editor for text manipulation |
| 18 | awk | Text processing language for pattern scanning and processing |
| 19 | cut | Cut out selected columns from a file |
| 20 | paste | Merge lines of files |
| No. | Command | Description |
|---|
| 21 | ps | Process list |
| 22 | top | Dynamic real-time view of system processes |
| 23 | kill | Terminate a running process |
| 24 | free | Display information about system memory usage |
| 25 | df | Display disk usage information |
User management Commands
| No. | Command | Description |
|---|
| 26 | useradd | Create a new user account |
| 27 | usermod | Modify an existing user account |
| 28 | userdel | Delete a user account |
| 29 | passwd | Set or change a user’s password |
| 30 | id | Display user and group information |
| 31 | groups | List the groups a user belongs to |
| 32 | su | Switch user |
| 33 | sudo | Execute commands with superuser privileges |
| 34 | chage | Modify password aging parameters for a user |
| 35 | pw | Manage user passwords and shadow files (specific to some distributions) |
File Permission and Ownership Commands
| No. | Command | Description |
|---|
| 36 | chmod | Change file permissions |
| 37 | chown | Change file ownership |
| 38 | chgrp | Change file group ownership |
| 39 | umask | Set default file permissions for newly created files and directories |
| 40 | chroot | Change the root directory of a process |
Additional Usecase Commands
| Command | Description |
|---|
man | Display online manual pages |
find | Search for files in a directory hierarchy |
tar | Archive and compress files |
unzip | Unzip compressed files |
wget | Download files from the internet |
ssh | Secure Shell for remote login |
scp | Secure Copy for copying files over SSH |
top | Display system processes |
htop | Interactive process viewer |