In UNIX directories are treated as files, in fact a directory is a file. Directories have permissions associated with them as do files. 
• Given a file with permissions of 644 octal (rw- r-- r-- ) within a directory with permissions of 730 octal (rwx -wx ---) . How can this combination of permissions compromise the file? 
• Given a file with permissions of 444 octal (r-- r-- r-- ) within a directory with permissions of 770 octal (rwx rwx ---). How can this combination of permissions compromise the file? 
4. describe how UNIX permissions could be used to support shared access of files between the owner and the designated people in each scenario. 
• How would you allow access to file1 for person1? 
• How would you allow access to file1 for person1 and file2 for person2? 
• How effective are Unix permissions for allowing shared file access? What is an alternative to using permissions?