Linux - Environment variables - multichoice questions

Question 1

When a user runs the command who from the command line, which of the following best describes what happens?

• The shell asks the kernel to execute the contents of the file /usr/bin/who as a separate process, displaying the process's output on the terminal.
• The shell makes the who system call, prompting the Linux kernel for the output directly.
• The shell exits, and is replaced by the who process. When the who process terminates, it replaces itself with a new shell process.
• None of the above.

Question 2

Which of the following could not be used as the name of an environment variable?

• NAME
• PHONE_1
• Addr2
• ZipCode
• All of the above could be used as the name of an environment variable.

Question 3

Which of the following would correctly set the environment variable ADDR to “123 Elm St.”?

• ADDR= 123_Elm_St.
• export ADDR=123 Elm St.
• export ADDR="123 Elm St."
• export ADDR=123_Elm_St.
• None of the above.

Question 4

Which of the following is not a feature of environment variables?

• All processes use environment variables, not just those running the bash shell.
• Environment variables are inherited by child processes by default.
• Upon startup, the bash shell clears all previously defined environment variables.
• Environment variables can be examined using files found in the /proc filesystem.

Question 5

Which of the following commands would append the directory /opt/bin to the current value of the PATH environment variable?

• PATH=$PATH:/opt/bin
• PATH+=/opt/bin
• PATH=${PATH}+"/opt/bin"
• A and B
• All of the above

Question 6

The user elvis performs the following command.

[elvis@station elvis]$ export STYLE=terse

Which of the following commands would delete the environment variable STYLE?

• set
• env STYLE
• rm /proc/$$/environ
• import STYLE
• unset STYLE
• None of the above