Control characters
Not all the characters in a text file are things you can see when they are printed. Instead they indicate a different purpose.
Some common ones are shown here. You don’t need to remember them, but it helps you understand how text files work to realise these are just characters: they are non-printable characters. They have a number, but it doesn’t result in a symbol you can see (or the computer can print).
These are sometimes considered to be “invisible characters” (which includes space and tab).
code | name | abbreviation | display | notes |
---|---|---|---|---|
0 | null | NUL |
||
7 | bell | BEL |
^G |
beep! |
8 | backspace | BS |
^H |
|
9 | tab | HT |
^I |
horizontal tab (\t ) |
10 | line feed | LF |
^J |
newline (\n ) |
11 | vertical tab | VT |
^K |
|
12 | form feed | FF |
^L |
next page |
13 | carriage return | CR |
^M |
newline (\r ) |
26 | end of file | EOF |
^Z |
|
27 | escape | ESC |
^[ |
The display column here is not universal: by definition these characters are not displayed at all. But some programs represent them in this way, when indicating that they are there.