the way of restart:
sudo /opt/lampp/lampp restart
config root:
/opt/lampp/etc/httpd.conf
/opt/lampp/etc/httpd-xampp.conf
in each file we should change the deny config to allow
and one more thing is to change the rights of htdocs directory, with the order below:
sudo chmod a+w -R /opt/lampp/htdocs #change the rights of htdocs directory
sudo ln -sf /opt/lampp/htdocs/ ~/Public/ #create a link of htdocs for convience
reference pages:
http://haobinnan.blog.51cto.com/775253/750435
http://ifalone.me/569.html
http://blog.163.com/yuanzhf_2012/blog/static/2112011482012842515448/
原文：http://www.cnblogs.com/yedeying/p/3651013.html