[Shell] 分隔字符串为数组

#!/bin/bash
tmp="test,girl,boy,love"

OLD_IFS="$IFS"
IFS="," 
arr=($a)
IFS="$OLD_IFS"

echo "arr[0] is:  ${arr[0]}"

echo "arr len:  ${#arr[@]}"

for s in ${arr[@]}
do 
 echo "$s"
done

存储老的分隔符
OLD_IFS="$IFS"

设置分隔符
IFS=","

按着分隔符IFS自动分隔 
arr=($a)

分隔后的全部数组
${arr[@]}

分隔后的每一项
${arr[0]} ${arr[1]} ...

分割后的数组长度
${#arr[@]} 

存储整个索引值
${!arr[@]}