Hello everyone!
My name is Kyaw Soe Naing and I’m currently working as a Web Designer at WIT Lab Company. This week, I’ll be guiding you through the fundamentals of using the command line effectively.

As a developer, the command line (or terminal) is a powerful tool that allows you to interact with your system efficiently. It helps you navigate directories, manage files, and automate tasks—saving time and improving productivity. Mastering the command line can significantly enhance your workflow and make you a more efficient developer.

1. Navigation and Directory Management

When working in a project, you often need to move between directories, check where you are, and list files.

. Check Your Current Directory

pwd

pwd (Print Working Directory) – This command displays the full path of the directory you’re currently in. It's useful when you're lost and need to know your location in the file system.

. List Files and Directories

ls        # Show all files       
ls -a     # Show all files, including hidden ones (files starting with ".")
ls -l     # Show a detailed list (permissions, owner, size, date modified)
ls -lh    # Display file sizes in human-readable format (KB, MB, GB)
ls -la    # Show all files with details (combining -a and -l)
ls -lt    # Sort files by modification time (newest first)

ls (List) – This command shows the files and directories in your current location. It helps you see what’s inside a directory.

. Change Directories

cd folder_name   # Move into a folder
cd ..            # Move up one level (to the parent directory)
cd -             # Switch to the last directory you were in

cd (Change Directory) – This command allows you to move between directories. If you ever need to go back, use cd - to return to your last directory.

2. File and Directory Manipulation

Creating, copying, moving, and deleting files and directories is a crucial part of development.

. Create a New Directory

mkdir my_folder                     # Create a single directory
mkdir folder1 folder2 folder3        # Create multiple directories
mkdir "My Folder"                    # Create a directory with spaces in the name

mkdir (Make Directory) – Use this command to create folders where you can organize your files. If a directory name contains spaces, enclose it in quotes.

. Create Empty Files

touch newfile.txt                    # Create a single empty file
touch file1.txt file2.txt file3.txt   # Create multiple empty files

touch – This command is mainly used to create new empty files or update the last modified time of an existing file.

. Copy Files and Directories

cp file1.txt backup.txt               # Copy a file
cp file1.txt /home/user/Documents/     # Copy a file to another directory

cp (Copy) – This command duplicates a file or directory. It's useful for creating backups or duplicating files to work on different versions.

. Move and Rename Files

mv file1.txt /home/user/Documents/    # Move a file to another directory
mv oldname.txt newname.txt            # Rename a file

mv (Move) – This command is used to move files or directories from one location to another. If you use it with just a filename, it acts as a rename command.

. Delete Files and Directories

rm file1.txt            # Delete a single file
rm -r my_folder         # Delete a directory and its contents
rm -i file1.txt         # Ask for confirmation before deleting a file

rm (Remove) – Deletes files and directories. Be careful when using rm -r, as it will permanently delete a directory and everything inside it.

3. File Viewing and Editing

Often, developers need to open, read, or modify files directly in the terminal.

. Edit Files Using nano

nano myfile.txt

nano – A simple text editor that allows you to create and modify files inside the terminal. It’s useful for quick edits without opening a full GUI-based editor.

. View File Content

cat newfile.txt

cat (Concatenate) – This command displays the content of a file. It’s useful for quickly viewing small files without opening them in an editor.

. Combine Multiple Files into One

cat file1.txt file2.txt > merged.txt

cat with > (Redirect Output) – This command merges the contents of file1.txt and file2.txt into a new file called merged.txt.

. Write and Append Text to Files

echo "Hello World" > newfile.txt    # Overwrites file content with "Hello World"
echo "New Line" >> newfile.txt      # Appends "New Line" to the existing file

echo – Outputs text to the terminal or a file. Using > overwrites the file, while >> appends to the file.

Mastering these terminal commands will help you navigate, manage, and edit files efficiently. Whether you're developing web applications, working with servers, or managing your local projects, using the terminal can significantly speed up your workflow.

If you found this guide helpful, stay tuned for more tips and insights into web development and design!