bash 中的方向键大小写

如果按下上/左箭头键，是否可以在 bash 脚本中使用箭头键来运行一组特定的命令，如果按下下/右箭头键，则运行一组特定的命令？我试图找到一种方法，通过在显示数据时使用箭头键在用户之间快速切换，并使用此脚本从中读取数据。

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 https://github.com/jbondhus/last-seen/blob/master/last-seen.sh是完整的脚本。

注释为“等待用户输入”的读取命令是您按 Enter 键转到下一个用户的命令。基本上，这个脚本的作用是列出用户以及每个用户登录后经过的时间。我试图使用箭头键在显示的每个用户之间进行切换。我认为可以使用 case 语句来区分按键输入。重申我的观点，我不确定这是否可能。如果不是，有人能想出另一种方法来做到这一点吗？

您可以读取方向键以及其他键，无需任何异常命令；你只需要有条件地添加第二个read call:

escape_char=$(printf "\u1b")
read -rsn1 mode # get 1 character
if [[ $mode == $escape_char ]]; then
    read -rsn2 mode # read 2 more chars
fi
case $mode in
    'q') echo QUITTING ; exit ;;
    '[A') echo UP ;;
    '[B') echo DN ;;
    '[D') echo LEFT ;;
    '[C') echo RIGHT ;;
    *) >&2 echo 'ERR bad input'; return ;;
esac