A lightweight hosts management script by switch or merge hosts files to /etc/hosts
- create a folder to manage hosts files
 - put the hosts-switcher into the folder
 - chmod +x hosts-swicher
 
- create hosts files in the hosts management folder created above.
 - apply hosts files
 
- switch single hosts file to /etc/hosts
 
sudo ./hosts-swicher hostsFile1
- merge multipule hosts files to /etc/hosts
 
sudo ./hosts-swicher hostsFile1 hostsFile2 [hostsFile3...]
- the currently applied hosts files will be recorded in the host-switcher.log file.