Which of the following commands is used to update the list of available packages when using dpkg based package management?

• A. apt-get upgrade
• B. apt-cache update
• C. apt-get update
• D. apt-get refresh
• E. apt-cache upgrade

When running the command
sed -e "s/a/b/" /tmp/file >/tmp/file
While/tmp/file contains data, why is /tmp/file empty afterwards?

• A. The file order is incorrect. The destination file must be mentioned before the command to ensure redirection.
• B. Redirection for shell commands do not work using the > character. It only works using the | character instead.
• C. The command sed did not match anything in that file therefore the output is empty.
• D. When the shell establishes the redirection it overwrites the target file before the redirected command starts and opens it for reading.

What of the following statements are true regarding /dev/ when using udev? (Choose TWO correct answers.)

• A. When using udev, it is not possible to create block or character devices in /dev/ using mknod.
• B. Entries for all possible devices get created on boot even if those devices are not connected.
• C. The /dev/ directory is a filesystem of type tmpfs and is mounted by udev during system startup.
• D. The content of /dev/ is stored in /etc/udev/dev and is restored during system startup.
• E. Additional rules for udev can be created by adding them to /etc/udev/rules.d/.

After modifying GNU GRUB's configuration file, which command must be run for the changes to take effect?

• A. grub
• B. kill -HUP $(pidof grub)
• C. No action is required
• D. grub-install