我在寫一個工具是透過gpio判斷說要不要啟一些driver
===== (X) ash: cat sys/class/gpio/gpio123/value: bad number
if [ 0 -eq "cat sys/class/gpio/gpio123/value" ];then
echo "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
fi
===== (X) ash: cat sys/class/gpio/gpio123/value: bad number
if [ 0 -eq 'cat sys/class/gpio/gpio123/value' ];then
echo "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
fi
===== (O) AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
if [ 0 -eq `cat sys/class/gpio/gpio123/value` ];then
echo "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
fi
=====
為啥只能用`阿
這東西是什麼 (我是從別人code複製來的)
跟'不一樣嗎