How to disable/enable wifi in Raspberry headless(command line, terminal)?
如何在树莓派命令行终端中手动启用和禁用wifi？
禁用：
sudo iwconfig wlan0 txpower on
启用：
rfkill unblock wifi
sudo iwconfig wlan0 txpower on
如果不运行 rfkill unblock wifi，可能会碰到下面的错误：
✘
"Error for wireless request "Set Tx Power" (8B27) :
GET failed on device wlan0 ; Input/output error."