1. Let’s Encrypt通配符证书

https://certbot.eff.org/

./certbot-auto certonly -d "*.example.com" --manual --preferred-challenges dns-01 --server https://acme-v02.api.letsencrypt.org/directory

2. ffmpeg截取音频

ffmpeg -ss [start] -t [duration] -accurate_seek -i [in].mp3 -codec copy [out].mp3  
ffmpeg -ss 00:00:00 -t 00:10:11 -accurate_seek -i in.mp3 -codec copy out.mp3

3. SSH 通过代理连接

ssh -o ProxyCommand='nc -x 127.0.0.1:1080 %h %p' user@awshost