IntroToLinux

8. Essential File Commands

📂 File and Directory Operations

🔍 Viewing and Navigation

Command Purpose Example
ls 📋 List directory contents ls
ls -l 📊 Long format with details ls -l
ls -la 👁️ Include hidden files ls -la
ls -lh 📏 Human readable sizes ls -lh
pwd 📍 Print working directory pwd
cd 🚶 Change directory cd /etc
cd .. ⬆️ Go up one level cd ..
cd - ↩️ Go to previous directory cd -

✨ Creating Files and Directories

# 📄 Create files
touch filename.txt
touch file1.txt file2.txt file3.txt

# 📁 Create directories
mkdir dirname
mkdir project

# 🗂️ Create nested directories
mkdir -p path/to/nested/directories
mkdir -p project/src/main/java

📋 Copying and Moving

# 📄➡️📄 Copy files
cp file1.txt file2.txt
cp report.txt backup.txt

# 📁➡️📁 Copy directories (recursive)
cp -r directory1 directory2
cp -r project project-backup

# 🔄 Move/rename files
mv oldname.txt newname.txt
mv report.txt final-report.txt

# 📦 Move to different location
mv file.txt /path/to/destination/
mv document.txt ~/Documents/

🗑️ Removing Files and Directories

# ❌ Remove files
rm filename.txt

# ❓ Interactive removal (asks before deleting)
rm -i filename.txt

# 📁❌ Remove empty directories
rmdir empty_directory

# 🗂️❌ Remove directories with contents
rm -r directory_with_contents

# ⚠️ Force remove (be careful!)
rm -rf directory

⚠️ Warning: rm -rf is permanent! There’s no recycle bin in Linux!

📖 Viewing File Contents

Command Purpose Best For
cat filename.txt 📄 Display entire file Small files
less filename.txt 📖 View with paging Large files
more filename.txt 📑 View with paging (older) Legacy systems
head filename.txt ⬆️ First 10 lines Quick preview
tail filename.txt ⬇️ Last 10 lines Log files
head -20 file.txt ⬆️ First 20 lines Custom preview
tail -20 file.txt ⬇️ Last 20 lines Recent logs

💡 Pro Tip: Navigation in less

Key          Action
───────────────────────────────
Space        ⬇️ Next page
b            ⬆️ Previous page
/pattern     🔍 Search forward
?pattern     🔎 Search backward
q            🚪 Quit

✏️ Editing Files

# 📝 Simple text editor (beginner-friendly)
nano filename.txt

# 💾 Save in nano: Ctrl+O, then Enter
# 🚪 Exit nano: Ctrl+X

🌐 Downloading Files

# ⬇️ Download files from internet
wget https://example.com/file.txt

# 📥 Download with custom name
wget -O newname.txt https://example.com/file.txt

# 📊 Download with progress bar
wget --progress=bar https://example.com/largefile.zip

Next: → Getting Help With Commands
Previous: ← Essential Navigation Commands
Lesson Home: ↑ Lesson 2: The Shell
Course Home: ⌂ Introduction to Linux