http://blog.sina.com.cn/s/blog_9a76f42e0102wl7d.html

pushd 目录压栈
popd  目录弹栈
使用这两个目录，可把命令执行目录在多个目录中进行切换

使用例子：
------------------------开始-------------------------------------
@echo off
cd  /d  x:\
echo  inpath1=% cd%        => inpath1= x:\
pushd  x:\comp\
echo  inpath2=% cd%        => inpath2= x:\comp\

pushd  x:\comp\src\

echo  inpath3=% cd%        => inpath3= x:\comp\src\
pushd  x:\comp\file\
echo  inpath4=% cd%        => inpath4= x:\comp\file\

echo  pushd_end

echo  otpath1=% cd%        => otpath1= x:\comp\file\
popd
echo  otpath2=% cd%        => otpath2= x:\comp\src\
popd
echo  otpath3=% cd%        => otpath3= x:\comp\
popd
echo  otpath4=% cd%        => otpath4= x:\

---------------------结束-----------------------------