1. 定义数组
数组名=（元素1 元素2 元素3 ...）
2. 查看数组
declare -a
3. 访问数组元素
${arr[0]} 访问某一个元素
${#arr[@]} 访问所有元素
${!arr[@]} 访问所有下标
${arr[@]:2} 访问下标2开始的所有元素
${arr[@]:2:2} 访问下标2开始的后两个元素
When nothing seems to help, I go look at a stonecutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred and first blow it will split in two, and I know it was not that blow that did it, but all that had gone before. -- Jacob Riis