Windows
CMD
set http_proxy=http://192.168.123.254:7890
set https_proxy=http://192.168.123.254:7890
PowerShell
$Env:http_proxy="http://192.168.123.254:7890"
$Env:https_proxy="http://192.168.123.254:7890"
Linux
export https_proxy=http://192.168.123.254:7890
export http_proxy=http://192.168.123.254:7890
export ALL_PROXY=socks5://192.168.123.254:7891
Test
curl -I www.google.com