我想到的最好的方法是只做一个Registry查询。下面是我的例子。

In my example I did an install using a Batch file that added new environment variables. I needed to do things with this as soon as the install was complete, but was unable to spawn a new process with those new variables. I tested spawning another explorer window and called back to cmd.exe and this worked but on Vista and Windows 7, Explorer only runs as a single instance and normally as the person logged in. This would fail with automation since I need my admin creds to do things regardless of running from local system or as an administrator on the box. The limitation to this is that it does not handle things like path, this only worked on simple enviroment variables. This allowed me to use a batch to get over to a directory (with spaces) and copy in files run .exes and etc. This was written today from may resources on stackoverflow.com

原批处理调用新批处理:

testenvget。cmd SDROOT(或任何变量)

@ECHO OFF
setlocal ENABLEEXTENSIONS
set keyname=HKLM\System\CurrentControlSet\Control\Session Manager\Environment
set value=%1
SET ERRKEY=0

REG QUERY "%KEYNAME%" /v "%VALUE%" 2>NUL| FIND /I "%VALUE%"
IF %ERRORLEVEL% EQU 0 (
ECHO The Registry Key Exists 
) ELSE (
SET ERRKEY=1
Echo The Registry Key Does not Exist
)

Echo %ERRKEY%
IF %ERRKEY% EQU 1 GOTO :ERROR

FOR /F "tokens=1-7" %%A IN ('REG QUERY "%KEYNAME%" /v "%VALUE%" 2^>NUL^| FIND /I "%VALUE%"') DO (
ECHO %%A
ECHO %%B
ECHO %%C
ECHO %%D
ECHO %%E
ECHO %%F
ECHO %%G
SET ValueName=%%A
SET ValueType=%%B
SET C1=%%C
SET C2=%%D
SET C3=%%E
SET C4=%%F
SET C5=%%G
)

SET VALUE1=%C1% %C2% %C3% %C4% %C5%
echo The Value of %VALUE% is %C1% %C2% %C3% %C4% %C5%
cd /d "%VALUE1%"
pause
REM **RUN Extra Commands here**
GOTO :EOF

:ERROR
Echo The the Enviroment Variable does not exist.
pause
GOTO :EOF

还有另一种方法，我从各种不同的想法中想出的。请看下文。这基本上会得到最新的路径变量从注册表然而，这将导致一些问题，因为注册表查询将给出变量本身，这意味着到处都有一个变量，这将不会工作，所以为了解决这个问题，我基本上加倍的路径。非常讨厌的。更可取的方法是: 设置路径=%路径%;C:\Program Files\Software....\

不管这是新的批处理文件，请谨慎使用。

@ECHO OFF
SETLOCAL ENABLEEXTENSIONS
set org=%PATH%
for /f "tokens=2*" %%A in ('REG QUERY "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /v Path ^|FIND /I "Path"') DO (
SET path=%%B
)
SET PATH=%org%;%PATH%
set path

您可以使用vbs脚本捕获系统环境变量，但是需要使用bat脚本来实际更改当前环境变量，因此这是一种组合解决方案。

创建一个名为resetvars的文件。VBS中包含该代码，并保存到:

Set oShell = WScript.CreateObject("WScript.Shell")
filename = oShell.ExpandEnvironmentStrings("%TEMP%\resetvars.bat")
Set objFileSystem = CreateObject("Scripting.fileSystemObject")
Set oFile = objFileSystem.CreateTextFile(filename, TRUE)

set oEnv=oShell.Environment("System")
for each sitem in oEnv 
    oFile.WriteLine("SET " & sitem)
next
path = oEnv("PATH")

set oEnv=oShell.Environment("User")
for each sitem in oEnv 
    oFile.WriteLine("SET " & sitem)
next

path = path & ";" & oEnv("PATH")
oFile.WriteLine("SET PATH=" & path)
oFile.Close

创建另一个包含以下代码的文件名resetvars.bat，相同的位置:

@echo off
%~dp0resetvars.vbs
call "%TEMP%\resetvars.bat"

当您想要刷新环境变量时，只需运行resetvars.bat

护教学:

我提出这个解决方案时遇到的两个主要问题是

a.我找不到一个直接的方法将环境变量从vbs脚本导出回命令提示符，并且

b. PATH环境变量是用户变量和系统PATH变量的连接。

我不确定用户和系统之间的冲突变量的一般规则是什么，所以我选择让用户覆盖系统，除了在PATH变量中，它是专门处理的。

我使用奇怪的vbs+bat+临时bat机制来解决从vbs导出变量的问题。

注意:此脚本不删除变量。

这可能是可以改进的。

添加

如果你需要将环境从一个cmd窗口导出到另一个窗口，使用这个脚本(让我们称之为exportvars.vbs):

Set oShell = WScript.CreateObject("WScript.Shell")
filename = oShell.ExpandEnvironmentStrings("%TEMP%\resetvars.bat")
Set objFileSystem = CreateObject("Scripting.fileSystemObject")
Set oFile = objFileSystem.CreateTextFile(filename, TRUE)

set oEnv=oShell.Environment("Process")
for each sitem in oEnv 
    oFile.WriteLine("SET " & sitem)
next
oFile.Close

exportvars运行。VBS，然后切换到要导出的窗口，输入:

"%TEMP%\resetvars.bat"

调用这个函数对我来说很有用:

VOID Win32ForceSettingsChange()
{
    DWORD dwReturnValue;
    ::SendMessageTimeout(HWND_BROADCAST, WM_SETTINGCHANGE, 0, (LPARAM) "Environment", SMTO_ABORTIFHUNG, 5000, &dwReturnValue);
}

令人困惑的事情可能是，有几个地方可以启动cmd。 在我的情况下，我从windows资源管理器运行cmd，环境变量没有改变，而当从“运行”(windows键+ r)开始cmd时，环境变量被改变了。

在我的情况下，我只需要从任务管理器中杀死windows资源管理器进程，然后从任务管理器中重新启动它。

一旦我这样做了，我就可以从windows资源管理器衍生的cmd中访问新的环境变量。

环境变量保存在HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\Control\Session Manager\Environment中。

许多有用的环境变量，如Path，都存储为REG_SZ。有几种方法可以访问注册表，包括REGEDIT:

REGEDIT /E <“HKEY_LOCAL_MACHINE \ SYSTEM \ ControlSet001 \会话管理器\ \控制环境”

输出从神奇的数字开始。因此，要用find命令搜索它，它需要输入并重定向:type <filename> | findstr -c:\"Path\"

所以，如果你只是想用系统属性刷新当前命令会话中的路径变量，下面的批处理脚本可以很好地工作:

RefreshPath.cmd:

    @echo off

    REM This solution requests elevation in order to read from the registry.

    if exist %temp%\env.reg del %temp%\env.reg /q /f

    REGEDIT /E %temp%\env.reg "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager\Environment"

    if not exist %temp%\env.reg (
       echo "Unable to write registry to temp location"
       exit 1
       )

    SETLOCAL EnableDelayedExpansion

    for /f "tokens=1,2* delims==" %%i in ('type %temp%\env.reg ^| findstr -c:\"Path\"=') do (
       set upath=%%~j
       echo !upath:\\=\! >%temp%\newpath
       )

     ENDLOCAL

     for /f "tokens=*" %%i in (%temp%\newpath) do set path=%%i

可以通过在指定进程本身中覆盖环境表来实现这一点。

作为概念的证明，我写了这个示例应用程序，它只是在cmd.exe进程中编辑一个(已知的)环境变量:

typedef DWORD (__stdcall *NtQueryInformationProcessPtr)(HANDLE, DWORD, PVOID, ULONG, PULONG);

int __cdecl main(int argc, char* argv[])
{
    HMODULE hNtDll = GetModuleHandleA("ntdll.dll");
    NtQueryInformationProcessPtr NtQueryInformationProcess = (NtQueryInformationProcessPtr)GetProcAddress(hNtDll, "NtQueryInformationProcess");

    int processId = atoi(argv[1]);
    printf("Target PID: %u\n", processId);

    // open the process with read+write access
    HANDLE hProcess = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION | PROCESS_VM_READ | PROCESS_VM_WRITE | PROCESS_VM_OPERATION, 0, processId);
    if(hProcess == NULL)
    {
        printf("Error opening process (%u)\n", GetLastError());
        return 0;
    }

    // find the location of the PEB
    PROCESS_BASIC_INFORMATION pbi = {0};
    NTSTATUS status = NtQueryInformationProcess(hProcess, ProcessBasicInformation, &pbi, sizeof(pbi), NULL);
    if(status != 0)
    {
        printf("Error ProcessBasicInformation (0x%8X)\n", status);
    }
    printf("PEB: %p\n", pbi.PebBaseAddress);

    // find the process parameters
    char *processParamsOffset = (char*)pbi.PebBaseAddress + 0x20; // hard coded offset for x64 apps
    char *processParameters = NULL;
    if(ReadProcessMemory(hProcess, processParamsOffset, &processParameters, sizeof(processParameters), NULL))
    {
        printf("UserProcessParameters: %p\n", processParameters);
    }
    else
    {
        printf("Error ReadProcessMemory (%u)\n", GetLastError());
    }

    // find the address to the environment table
    char *environmentOffset = processParameters + 0x80; // hard coded offset for x64 apps
    char *environment = NULL;
    ReadProcessMemory(hProcess, environmentOffset, &environment, sizeof(environment), NULL);
    printf("environment: %p\n", environment);

    // copy the environment table into our own memory for scanning
    wchar_t *localEnvBlock = new wchar_t[64*1024];
    ReadProcessMemory(hProcess, environment, localEnvBlock, sizeof(wchar_t)*64*1024, NULL);

    // find the variable to edit
    wchar_t *found = NULL;
    wchar_t *varOffset = localEnvBlock;
    while(varOffset < localEnvBlock + 64*1024)
    {
        if(varOffset[0] == '\0')
        {
            // we reached the end
            break;
        }
        if(wcsncmp(varOffset, L"ENVTEST=", 8) == 0)
        {
            found = varOffset;
            break;
        }
        varOffset += wcslen(varOffset)+1;
    }

    // check to see if we found one
    if(found)
    {
        size_t offset = (found - localEnvBlock) * sizeof(wchar_t);
        printf("Offset: %Iu\n", offset);

        // write a new version (if the size of the value changes then we have to rewrite the entire block)
        if(!WriteProcessMemory(hProcess, environment + offset, L"ENVTEST=def", 12*sizeof(wchar_t), NULL))
        {
            printf("Error WriteProcessMemory (%u)\n", GetLastError());
        }
    }

    // cleanup
    delete[] localEnvBlock;
    CloseHandle(hProcess);

    return 0;
}

样例输出:

>set ENVTEST=abc

>cppTest.exe 13796
Target PID: 13796
PEB: 000007FFFFFD3000
UserProcessParameters: 00000000004B2F30
environment: 000000000052E700
Offset: 1528

>set ENVTEST
ENVTEST=def

笔记

这种方法也仅限于安全限制。如果目标在更高的海拔或更高的帐户(如SYSTEM)上运行，那么我们将没有权限编辑它的内存。

如果你想对一个32位的应用程序这样做，上面的硬编码偏移量将分别更改为0x10和0x48。这些偏移量可以通过在调试器中转储_PEB和_RTL_USER_PROCESS_PARAMETERS结构体来找到(例如在WinDbg dt _PEB和dt _RTL_USER_PROCESS_PARAMETERS中)

要将概念证明更改为OP需要的内容，只需枚举当前系统和用户环境变量(如@tsadok的答案所记录的那样)，并将整个环境表写入目标进程的内存中。

Edit: The size of the environment block is also stored in the _RTL_USER_PROCESS_PARAMETERS struct, but the memory is allocated on the process' heap. So from an external process we wouldn't have the ability to resize it and make it larger. I played around with using VirtualAllocEx to allocate additional memory in the target process for the environment storage, and was able to set and read an entirely new table. Unfortunately any attempt to modify the environment from normal means will crash and burn as the address no longer points to the heap (it will crash in RtlSizeHeap).