Here’s a comprehensive note on essential Unix commands with examples

1. pwd – Print Working Directory

Displays the current directory you're working in.

   $ pwd
   /home/user

2. ls – List Directory Contents

Lists files and directories in the current directory.

   $ ls
   Documents Downloads Music Pictures

Options:

• -l: Long listing format.
• -a: Show hidden files.

   $ ls -la
   drwxr-xr-x  2 user user 4096 Sep 12 12:34 .
   drwxr-xr-x 25 user user 4096 Sep 11 13:14 ..
   -rw-r--r--  1 user user  220 Sep 12 11:32 .bashrc

3. cd – Change Directory

Navigates to a different directory.

   $ cd /home/user/Documents

To go back to the previous directory:

   $ cd -

4. mkdir – Make Directory

Creates a new directory.

   $ mkdir new_folder

5. rmdir – Remove Directory

Deletes an empty directory.

   $ rmdir old_folder

6. rm – Remove Files or Directories

Deletes files or directories.

   $ rm filename.txt

To remove a directory and its contents:

   $ rm -r directory_name

Force deletion without confirmation:

   $ rm -rf directory_name

7. touch – Create a New File

Creates an empty file.

   $ touch file.txt

8. cp – Copy Files or Directories

Copies files or directories.

   $ cp source.txt destination.txt