echo -e "\e[43;35m chenyu\e[0m hello word"

#!/bin/bash
for i in {30..37}
do
 echo -e "\e[1;${i}m chenyu\e[0m hello word"
done
echo "--------------"
for((i=47; i>=40; --i))
do
 echo -e "\e[$i;$[$i - 10]m chenyu \e[0m abcd\e[1;$[$i - 10]m chenyu\e[0m hello word"
done
#兩個字符串相加
chenyu="chen";
chen=${chenyu}"yu"
echo $chen
#數字相加10
a=10;
b=$(($c+10));
echo $b;
#數字相加10
c=20;
d=$[$c+10];
echo $d;