Terminal Escape & ANSI Escape Sequences
What is an Escape Sequence?
- Escape sequences are special character sequences starting with the Escape (ESC,
\x1B, ASCII 27) character. - They instruct the terminal to perform actions (move cursor, change color, etc.), not display text.
What are ANSI Escape Sequences?
- ANSI escape sequences are standardized escape codes as defined by ANSI X3.64 (ECMA-48).
- Used for cursor movement, text styling, color, and screen control in terminals.
Structure of ANSI Escape Sequences
- ESC =
\x1B [= control sequence introducer (CSI)- parameters = numbers/arguments (optional)
- command = final letter denoting action
Common Examples
| Sequence | Effect | Usage Example |
|---|---|---|
\x1B[0m | Reset styles | End colored text |
\x1B[1m | Bold on | Headings |
\x1B[31m | Red text | Error messages |
\x1B[2J | Clear entire screen | Redraw UI |
\x1B[5A | Cursor up 5 lines | Progress refresh |
\x1B[?25l | Hide cursor | During animation |
\x1B[?25h | Show cursor | After animation |
Why Use ANSI Escape Sequences?
- Fine-grained control: Layout, cursor, text color, and more.
- Critical for CLI/TUI interactivity.