Day 3: Reading and Comparing Files via CLI 🛠️

Day 3 of my #1HourADayJourney. Today's lab was all about File Content Inspection. When you're managing a database, you spend a lot of time looking at logs. Here is my technical summary:

📖 Reading Files

Instead of opening a full editor, these commands are much faster:

• cat -n: View file with line numbers.
• head -n5: Look at the first 5 lines.
• tail -c6: Look at the last 6 bytes (useful for checking specific EOF markers).
• grep "pattern": Search for specific strings within a file.

🔄 Redirection (The Power of > vs >>)

I practiced combining files:

bash
cat file1 file2 > mixtext.txt  # Overwrites the file
cat file1 >> mixtext.txt       # Appends to the end of the file

⚖️ Comparing Data
This is the most interesting part. Using diff to see what changed between files:

bash
diff file1 file2               # Line-by-line comparison
diff -r dir1 dir2              # Recursive directory comparison

Self-Correction Today: I tried cat -n1 and got an error. Learned that cat uses -n for lines, while head and tail use -n [number]. Tiny details matter in CLI!

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