I'm a little late to the party, but I wrote this little bash script for Mac that creates a VirtualHost through the terminal:
#!/bin/bash
echo "Welcome to the VirtualHostCreator! Press <RETURN> to continue."
read
echo "Enter the name the VirtualHost you would like to create. No spaces or dashes, please."
read hostname
echo "Enter the document root of the VirtualHost."
read doc_root
echo "Creating VirtualHost \"$hostname\". You may be prompted for your password."
hosts_file="/etc/hosts"
vhosts_file="/Applications/XAMPP/xamppfiles/etc/extra/httpd-vhosts.conf"
restart_command="sudo /Applications/XAMPP/xamppfiles/xampp restart"
cat >> $vhosts_file << EndOfMessage
<VirtualHost ${hostname}>
ServerName ${hostname}
DocumentRoot "/Applications/XAMPP/xamppfiles/htdocs/${doc_root}"
</VirtualHost>
EndOfMessage
sudo sh -c "echo \"127.0.0.1 $hostname\" >> $hosts_file"
$restart_command
I'm sure there are a few improvements that can be made, and it only has the two required options for the vhost (server name and document root), but it does the job much more quickly and efficiently than opening and editing all the files manually, and also automatically restarts XAMPP afterwards.
This assumes that you have the default installation location for XAMPP, which can all be changed.