Label: Linux
One command syntax function: find out the IP host hostname [server] [server] of a host name: use the DNS server IP not defined by the/etc/resolv.conf file to query the IP of a host.
The main function of the tree command is to create a list of files. It is more powerful to list all files in the tree form under Linux. But generally, the system does not come with this command, so you need to download and install it manually.
One startup and self startup service startup: it is to make the service run and provide functions in the current system.
