Ubuntu Tips

Command

• snap

$ sudo snap set system proxy.http="http://<proxy_addr>:<proxy_port>"
$ sudo snap set system proxy.https="http://<proxy_addr>:<proxy_port>"

永久擦除硬盘数据

• shred

shred -v /dev/sdb
shred -v -n 1 --random-source=/dev/urandom -z /dev/sdb

• wipe

wipe /dev/sdb

• dd

dd if=/dev/urandom of=/dev/sdb bs=512 status=progress

• net

# sudo netstat -tuln | grep <端口号>
sudo netstat -tuln | grep 5000
# sudo lsof -i:<端口号>
sudo lsof -i:5000

• ufw

  # start
  ufw enable
  # status with number
  ufw status numbered
  # open 
  ufw allow 22
  # limit the ip
  ufw allow from 10.0.0.0/24 to any port 27017
  ufw allow from 192.168.184.8 to any port 3306 proto tcp
  # delete rule
  ufw delete [number]
  # allow tcp
  ufw allow 80/tcp
  # delete rule
  ufw delete allow 443/tcp
  # deny
  ufw deny 23/tcp