Ubuntu关闭进入screensaver模式

/*********************************************************************************
 *                           Ubuntu关闭进入screensaver模式
 * 说明：
 *     在一定时间内未进行shell操作，系统会进入screensaver模式，通过uboot参数禁止。
 *
 *                                              2018-2-26 深圳 宝安西乡 曾剑锋
 ********************************************************************************/

一、参考文档：
    . How do I disable the blank console “screensaver” on Ubuntu Server?
        https://askubuntu.com/questions/138918/how-do-i-disable-the-blank-console-screensaver-on-ubuntu-server/356847
    . setterm command failing: "xterm does not support --blank" and "Inappropriato ioctl for device"
        https://github.com/mdrjr/cloudshell_lcd/issues/2
    . Jessie : How to disable CLI screen blanking ? [SOLVED]
        https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=122112&sid=6931a43dd5a063441a1d720bdc94b386
    . Disable screen blanking on text console
        https://unix.stackexchange.com/questions/8056/disable-screen-blanking-on-text-console
    . Prevent Raspberry Pi console screen blanking
        https://defgw.wordpress.com/2015/11/29/raspberry-pi-screen-blanking/

二、原因：
    Type setterm -blank  on any shell to disable blanking out of tty consoles.  disables blanking, any value greater than  is the time in minutes. Default is . To permanently enable this you can add this line to your ~/.bashrc config.