How does `cat -b` differ from `cat -n`?

Great question! While both options add line numbers, the difference lies in how they treat blank (empty) lines.

Here is the breakdown:

1. cat -n (Number all)

• Action: Numbers every single line, regardless of whether it has text or is completely empty.
• Use case: Best when you need to know the exact total line count or reference a specific line regardless of content.

2. cat -b (Number non-blank)

• Action: Numbers only the lines that contain text. It skips numbering for empty lines.
• Use case: Best when you are reading code or text where blank lines are just for spacing and you only care about the lines with actual data.

Comparison Example

Imagine a file with this content (a word, a blank line, and another word):

Hello

World

Using cat -n:

     1  Hello
     2  
     3  World

(Notice line 2 is numbered even though it is empty.)

Using cat -b:

     1  Hello
        
     2  World

(Notice the blank line is skipped, and "World" becomes line 2.)

Summary Table

Note: If you use both at the same time (cat -nb), -b actually takes priority, and blank lines will not be numbered.