Changing Identity

Question 1

The su command allows..?

Answer 1

a user to switch user id.

Question 2

The su command is usually called with…?

Answer 2

a hyphen, such as su -, to specify that the user should effectively log in as the new user.

Question 3

The newgrp command, also called sg, allows a user to…?

Answer 3

switch primary group id.

Question 4

The command that allows you to temporarily switch user id is called…?

Answer 4

simple su.

Question 5

When using the su command, the shell is called a…?

Answer 5

non-login shell. (Example, prince didn’t fully log in - the prompt indicates he’s still sitting in elvis’s home directory. Although the shell, and all that it starts, belongs to prince, much of the shell’s environment was inherited from elvis.
In order to completely log in as a new user, the su command can be called with a - (a bare hyphen). This specifies that the new user’s shell should be a login shell.

Question 6

If a user knows the password to the root account, this is often done by…?

Answer 6

“suing” to the root. If called without an argument, the su command assumes that the user is trying to become root.

Question 7

In Linux and Unix, the root account is sometimes referred to as the ….?

Answer 7

“superuser”. This term probably came about because of a misunderstanding of the meaning of the letters of the su command which are so often used to become root. Rather than superuser, the letters stand for switch userid.

Question 8

command for making new groups…?

Answer 8

newgrp command, equivalently called the sg command.