bash 根据字符串获得对应名字的变量值

MESSAGE="Hello, world!"
KEY="MESSAGE"
echo "${!KEY}"

VAR1="AAA"
VAR2="BBB"
VAR3="CCC"

for i in 1 2 3
do 
  KEY="VAR$i"
  echo "${!KEY}"
done

VAR1="AAA"
VAR2="BBB"
VAR3="CCC"

for i in 'VAR1' 'VAR2' 'VAR3'
do 
  if [[ "${!i}" == "CCC" ]]; then
    echo "Found variable $i which value is CCC"
  fi
done