linux 循环

#!/bin/sh
for i in {1..2};do
        b=$i
        let "b=b+1"
        let "b++"
        ((b++))
        echo "aaa "$b
done

for((i=2;i<10;i+=3));do
        echo "bbb "$i
done

a=(a b c d)

#取数组元素
echo ${a[@]}

#取数组长度
echo ${#a[*]}
echo ${a[2]}
for ii in ${a[@]};do
        echo "aaa " $ii
done

注意：数组用的是圆括号，元素之间用空格隔开的

i=0
len=${#a[*]}
echo $len
while [ $i -lt $len ]
do
        echo ${a[$i]}
        let "i=i+1"
done