SHELL

give permission to file ubuntu

sudo chmod 777 /path

giving permission to folder in ubuntu

chmod -R a+rwx path

assign permission to files and folder ubuntu separate

To change all the directories to 755 (drwxr-xr-x):
find /opt/lampp/htdocs -type d -exec chmod 755 {} ;

To change all the files to 644 (-rw-r--r--):
find /opt/lampp/htdocs -type f -exec chmod 644 {} ;