Operator Description
-g Does filename have its set group ID bit set?
-k Does filename have its "sticky bit" set?
-r Is filename a readable file?
-u Does filename have its set user ID bit set?
-w Is filename a writable file?
-x Is filename an executable file?
-R Is filename readable only if the real user ID can read it?
-W Is filename writable only if the real user ID can write?
-X Is filename executable only if the real user ID can execute it?