You want to save vi changes to the file myfile with :w!, but vi complains it can not write to the file. Therefore, you want to check the write permissions on the file. To do this without leaving vi, you type:
:!ls -l myfile
:\ls -l myfile
esc :ls -l myfile
:?ls -l myfile
Want to practice for 150-810 - Brocade Certified Ethernet Fabric Professional 2013 Exam ?