天工造物局

先判断该环境变量是否已经存在,如果不存在则添加该环境变量。

@echo off
    @set Path_=D:\Program Files
    for,/f,"skip=4 tokens=1,2,*",%%a,in,('reg query "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Environment" /v Path'),do,( 
    @set PathAll_=%%c
    )
    echo %PathAll_%|find /i "%Path_%" && set IsNull=true|| set IsNull=false
    if not %IsNull%==true (
          reg add "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Environment" /v Path /t REG_EXPAND_SZ /d "%PathAll_%;%Path_%" /f
    )
pause