/*********************************************************************************
* 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：
1. 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
2. setterm command failing: "xterm does not support --blank" and "Inappropriato ioctl for device"
https://github.com/mdrjr/cloudshell_lcd/issues/2
3. Jessie : How to disable CLI screen blanking ? [SOLVED]
https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=122112&sid=6931a43dd5a063441a1d720bdc94b386
4. Disable screen blanking on text console
https://unix.stackexchange.com/questions/8056/disable-screen-blanking-on-text-console
5. Prevent Raspberry Pi console screen blanking
https://defgw.wordpress.com/2015/11/29/raspberry-pi-screen-blanking/
二、原因：
Type setterm -blank 0 on any shell to disable blanking out of tty consoles. 0 disables blanking, any value greater than 0 is the time in minutes. Default is 10. To permanently enable this you can add this line to your ~/.bashrc config.
