📅  最后修改于: 2022-03-11 14:49:55.709000             🧑  作者: Mango
echo "enter a char"
read c
if [[ $c == [A-Z] ]];
then
echo "upper"
elif [[ $c == [a-z] ]];
then
echo "lower"
else
echo "Digit or special symbols!"
fi