新增于: v13.5.0, v12.16.0
返回光标相对于输入提示 + 字符串的实际位置。长输入(换行)字符串以及多行提示都包含在计算中。
¥Returns the real position of the cursor in relation to the input
prompt + string. Long input (wrapping) strings, as well as multiple
line prompts are included in the calculations.