Command cat has a -t option
-t Display non-printing characters (see the -v option), and display tab characters as
^I.
The tab character is represented by ^I.
I searched an explanation as:
This is a common notation that means “Control-I” which, as it turns out, is the same as a tab character.
Apparently, there's no connections of I and tab in spelling and meaning.
How to understand it?
How to understand it?
By reading a manual page that has been around since Version 7 UNIX:
man ascii
See the code for the ␉ (Horizontal Tab) character. Like most control codes, this can be typed on terminals with the chord ⎈ Control+I. Notice what you get if you subtract 64 from the code for the I character.
Observe the pattern with, say, ⎈ Control+J and ␊ (Line Feed). Realize, once you remember where @ is in a U.S. keyboard layout, why ⎈ Control+2 is thus ␀.
I searched an explanation
Always check out the manual. The manual, certainly on the BSDs but in cases like this one on Linux operating systems as well, is your friend.
