Most Commonly Used Shell Commands

1. ls - List directory contents

  • Lists files and directories in the current directory.
ls
ls -l   # Long format
ls -a   # Show hidden files
ls -lh  # Human-readable sizes

2. cd - Change directory

  • Changes the current directory.
cd directory_name
cd ..        # Move up one directory
cd ~         # Move to home directory
cd /path/to/directory  # Absolute path

3. pwd - Print working directory

  • Displays the path of the current directory.
pwd

4. mkdir - Make directory

  • Creates a new directory.
mkdir directory_name

5. rm - Remove

  • Deletes files or directories.
rm filename
rm -r directory_name   # Recursively remove directory
rm -f filename          # Force remove without prompt

6. cp - Copy

  • Copies files or directories.
cp source_file destination_file
cp -r source_directory destination_directory   # Recursive copy

7. mv - Move

  • Moves or renames files or directories.
mv source_file destination_file
mv old_name new_name  # Rename

8. cat - Concatenate and display

  • Displays content of a file.
cat filename

9. grep - Global Regular Expression Print

  • Searches for a pattern in files.
grep "pattern" filename
grep -r "pattern" directory_name  # Recursively search

10. echo - Print

  • Displays text on the terminal.
echo "Hello, World!"

11. chmod - Change mode

  • Changes permissions of files and directories.
chmod +x file       # Add execute permission
chmod 755 file      # Octal notation (rwxr-xr-x)

12. chown - Change owner

  • Changes the owner of files and directories.
chown user:group file

13. sudo - Superuser do

  • Executes a command with superuser privileges.
sudo command

14. top - Display system processes

  • Shows currently running processes.
top

15. df - Display filesystem usage

  • Shows disk space usage.
# Display Filesystem Usage in Human-readable Format
df -h

# Display Filesystem Type
df -T

# Display Inode Usage
df -i

# Output in POSIX Format
df -P

# Display Filesystem Usage with Type in Human-readable Format
df -hT