/**
* Backspaces characters.
*
* @param int $n The number of characters to backspace.
*
* @return true on success, false on failure
*/
private function _backspace($n = 1)
{
if ($this->_buffer_position < $n) {
// We can't backspace this far
return false;
}
ob_start();
for ($i = 0; $i < $n; $i++) {
if ($this->_buffer_position < mb_strlen($this->_buffer)) {
$head = mb_substr($this->_buffer, 0, $this->_buffer_position);
$tail = mb_substr($this->_buffer, $this->_buffer_position, mb_strlen($this->_buffer));
Terminal::backspace();
echo $tail . ' ';
Terminal::left(mb_strlen($tail) + 1);
// Update buffer
$this->_buffer = mb_substr($head, 0, mb_strlen($head) - 1) . $tail;
} else {
// Just backspace one char
$this->_buffer = mb_substr($this->_buffer, 0, mb_strlen($this->_buffer) - 1);
Terminal::backspace();
}
$this->_buffer_position--;
}
ob_end_flush();
return true;
}