Dump File Create with .Bat File

 @echo off

rem Get current date and time in a format that can be used in filenames

for /F "tokens=2 delims==" %%I in ('"wmic os get localdatetime /value"') do set datetime=%%I

set year=%datetime:~0,4%

set month=%datetime:~4,2%

set day=%datetime:~6,2%

set hour=%datetime:~8,2%

set minute=%datetime:~10,2%

set second=%datetime:~12,2%

rem Remove dashes from the date and time format

set dumpfile=portal_%year%%month%%day%%hour%%minute%%second%.dmp

rem Run the expdp command with the dynamically generated dumpfile name

expdp portal/portal directory=impdir dumpfile=%dumpfile% schemas=portal