Question

我试图创建一个将在后台持续运行的BASH脚本。这个bash脚本应该从命令rpi-cecd请求结果，如果它包含45:00，做一些事情，如果它包含45:03，那么做其他事情。但是目前，如果我要求不止一个结果，我就无法使脚本工作。

工作代码，但仅要求45:00

/home/rpi-cecd/rpi-cecd | grep -q "45:00" && ok

我试过的代码，但根本没用。

/home/rpi-cecd/rpi-cecd | grep '45' > /dev/null
if [[ $? =~ .*45:00.* ]]
then
    echo "OK Button Clicked - HMS"
    ok
elif [ $? == *"45:03"* ]
then
    echo "Left Button Clicked - Canteen"
    left
else
    echo "Nothing Clicked?"
fi

修改我只是试着这个没有运气。

hhmm=$(/home/rpi-cecd/rpi-cecd)
case "$hhmm" in
        45[:]00 )
                ok
                ;;
        45[:]03 )
                left
                ;;
        * )
                 echo "don't know how to process $hhmm"
                ;;
esac

Answer 1

If rpi-cecd runs continuously without exiting, you can't just capture its output once. You need to continually read from it. You can do that by piping its output to a while read loop.

/home/rpi-cecd/rpi-cecd | while IFS= read -r line; do
    case $line in
        *45:00*)
            ok
            ;;
        *45:03*)
            left
            ;;
        *)
            echo "don't know how to process $line"
            ;;
    esac
done

Answer 2

在使用之前，您可能需要清理答案：

payload=
while read line;do
    [ "$line" ] && [ -z "${line//*payload=*}" ] && payload=${line#*payload=[}
  done < <(/home/rpi-cecd/rpi-cecd)

case ${payload%%]*} in
    *45:00 ) 
        echo payload 45oo
        ;;
    *45:03 )
        echo payload 45.3
        ;;
    * )
        echo "other ("${payload%%]*}")..."
        ;;
    esac

BASH |如果命令等于某事，否则如果做某事

2 个答案: