如何获得X分配的显示编号
从X(7)手册页 DISPLAY NAMES From the user's perspective, every X server has a display name of the form: hostname:displaynumber.screennumber [...] displaynumber [...] To avoid confusion, each display on a machine is assigned a display number (beginning at 0) when the X server for that display is started. 如何找到已分配的显示编号? 还是列出当前打开的显示器及其用户?