1. Write the octal equivalents for the following binary numbers:100,111,101,011, and 010.
2. Write how to express*nix owner permissions of r-x in binary (Remember that the -symbol means the permission isn’t granted.) What’s the octal representation of the binary number you calculated? (The range of numbers expressed in octal is 0 to7. Because*nix has three sets of permissions, three sets of 3binary bits logically represent all possible permissions.)
3. In binary and octal numbering, how do you express granting read, write, and execute permission to the owner of a file and no permissions to anyone else?
4. In binary and octal numbering, how do you express granting read, write, and execute permission to the owner of a file, read and write permission to group, and read permission to other?
5. In UNIX, a file can be created by using a umask, which enables you to modify the default permissions for a file or directory. For example, a directory has the default permission of octal 777. If a UNIX administrator creates a directory with a umask of octal 020, what effect does this setting have on the directory? Hint: To calculate the solution, you can subtract the octal umask value from the octal default permissions.
6. The default permission for a file on a UNIX system is octal 666. If a file is created with a umask of octal 022, what are the effective permissions? Calculate the results.