awk用法 :http://blog.csdn.net/braveyly/article/details/6313779
awk应用小结:http://mcshell.blog.51cto.com/803455/211440
基本语法和echo用法等:http://www.aka.org.cn/Lectures/002/Lecture-2.1.2/bash-syntax.html用
date 用法:http://digdeeply.org/archives/06112057.html'
if条件控制语句:http://blog.csdn.net/flowingflying/article/details/5069646
cat 用法 http://codingstandards.iteye.com/blog/801090
wc命令 http://blog.csdn.net/cemer815/article/details/5846282
逻辑判断符号 http://www.cnblogs.com/chengmo/archive/2010/10/01/1839942.html