onDidWrite

An event that when fired will write data to the terminal. Unlike Terminal.sendText which sends text to the underlying child pseudo-device (the child), this will write the text to parent pseudo-device (the terminal itself).

Note writing \n will just move the cursor down 1 row, you need to write \r as well to move the cursor to the left-most cell.

Events fired before Pseudoterminal.open is called will be be ignored.

Example: Write red text to the terminal

const writeEmitter = new vscode.EventEmitter<string>();
const pty: vscode.Pseudoterminal = {
  onDidWrite: writeEmitter.event,
  open: () => writeEmitter.fire('\x1b[31mHello world\x1b[0m'),
  close: () => {}
};
vscode.window.createTerminal({ name: 'My terminal', pty });

Example: Move the cursor to the 10th row and 20th column and write an asterisk

writeEmitter.fire('\x1b[10;20H*');

Online Documentation