dos 当前日期写出文件

set datetime=%Date:~0,4%%Date:~5,2%%Date:~8,2%%Time:~0,2%%Time:~3,2%%Time:~6,2%

:: 过滤掉因10点前时间出现的空格，如： 20130613 91337,将其空格替为0

set datetime=%datetime: =0% 

echo %datetime%>c:\datetime.txt