shell脚本截取日期处理

[Author]: kwu

在linux中日期格式化固定为8位：2015-01-01

如实现 2015-1-1 需要进行字符串处理

#!/bin/sh
# upload logs to hdfs

yesterday2="2015-01-08"

echo ${yesterday2}

first=${yesterday2:5:1}
second=${yesterday2:8:1}

echo ${first}
echo ${second}

res=$yesterday2
echo ${res}

if [ $first -eq 0 ] && [ $second -eq 0 ]
then
    res=${yesterday2:0:5}${yesterday2:6}
    res=${res:0:7}${res:8}
elif [ $first -eq 0 ]
then
    res=${yesterday2:0:5}${yesterday2:6}
elif [ $second -eq 0 ]
then
    res=${yesterday2:0:8}${yesterday2:9}
fi

echo ${res}

如上命令最终输出为

2015-1-8