---------- CHMOD COMMON PERMISSIONS ---------- 

400 	r-------- 	Readable by owner only
500 	r-x------ 	Avoid Changing
600 	rw------- 	Changeable by user
644 	rw-r--r-- 	Read and change by user
660 	rw-rw---- 	Changeable by user and group
700 	rwx------ 	Only user has full access
755 	rwxr-xr-x 	Only changeable by user
775 	rwxrwxr-x 	Sharing mode for a group
777 	rwxrwxrwx 	Everybody can do everything