History, PATH and manuals

Questions 1 to 5 of 9

1. 1. You press Ctrl+R and type beta. The shell shows echo beta-two. You then press Enter once. What happens?

   The command runs and prints beta-twoThe command is placed on the line, and you can edit it before you run itThe search closes and the line is clearedBash deletes the matching entry from the history
2. 2. After Ctrl+R has put an old command on the line, which key combination moves the cursor to the end of the line? Write the key combination.

   Type your answer.

3. 3. The previous command was apt update. You type sudo !! and press Enter. What does the shell do?

   Prints apt update and never runs itDeletes the !! line from the historyRuns sudo with no arguments, which prints an errorRuns apt update again with sudo in front
4. 4. Run this code in bash. What line does it print? ``bash add_path() { [ -d "$1" ] || return 0 case ":$PATH:" in *":$1:"*) ;; *) PATH="$PATH:$1" ;; esac } PATH=/usr/bin:/bin add_path /usr/bin add_path /etc add_path /no-such-folder echo "$PATH" ``

   /usr/bin:/bin:/usr/bin:/etc/usr/bin:/bin:/etc:/no-such-folder/usr/bin:/bin:/etc/etc:/usr/bin:/bin
5. 5. This line is in ~/.bashrc to add ~/bin to PATH. After it, new windows cannot find ls or cat: ``bash PATH=$HOME/bin `` What is the bug?

   It replaces PATH with only ~/bin, so the system folders are gone and bash cannot find ls or catThe quotes around $HOME are missing, so the line is a syntax errorThe folder ~/bin must already exist, or bash refuses the lineIt should use >> instead of =, because PATH can only be added to