在bash中如何使用箭头键进行大小写转换

在bash脚本中，是否可以将箭头键用作触发器，当按下向上/向左箭头键时运行一组指令，按下向下/向右箭头键时运行另一组指令？我想要一种方法来在显示数据时使用箭头键快速切换用户，使用此脚本读取数据。

function main()  # The main function that controls the execution of all other functions
{
  mkdir -p ~/usertmp  # Make a new temporary user directory if it doesn't exist
  touch ~/last_seen_output.txt  # Create the output file if it doesn't exist
  cat /dev/null > ~/last_seen_output.txt  # Make sure that the output file is empty
  gather  # Call the "gather" function
  total=$((`wc -l ~/usertmp/user_list.txt|awk '{print $1}'`-1))  # Calculate the total amount of lines and subtract 1 from the result
  echo Current Time: `date +%s` > ~/last_seen_output.txt  # Print the current time to the output file for later reference
  echo "" > ~/last_seen_output.txt  # Print a blank line to the output file
    if [ $log -eq 1 ]
      then
        # If it is enabled, then delete the old backups to prevent errors
        while [ $line_number -le $total ]
          do

            line_number=$((line_number+1))  # Add 1 to the current line number
            calculate # Call the "calculate" function
            hms  # Call the "hms" function to convert the time in seconds to normal time
            log
        done
      else
        while [ $line_number -le $total ]
          do
            line_number=$((line_number+1))  # Add 1 to the current line number
            calculate # Call the "calculate" function
            hms  # Call the "hms" function to convert the time in seconds to normal time
            echo "Displaying, please hit enter to view the users one by one."
            read  # Wait for user input
            if [ "$log_while_displaying" ]
              then
                log
                display
              else
                display
            fi
        done
    fi
}

https://github.com/jbondhus/last-seen/blob/master/last-seen.sh 是完整的脚本。
read命令被注释为“等待用户输入”，它是您按Enter键以继续下一个用户的命令。基本上，此脚本会列出用户及其登录后经过的时间。我正试图使用箭头键在每个用户之间进行切换。我想这可能可以使用case语句来处理键盘输入。重申一下，我不确定这是否可行。如果不行，有人能想到其他方法吗？