如果修改或添加环境变量,则必须重新启动命令提示符。是否有一个命令,我可以执行,将这样做而不重新启动CMD?


当前回答

我使用这个Powershell脚本添加到PATH变量中。 只要稍加调整,我相信它也适用于你的情况。

#REQUIRES -Version 3.0

if (-not ("win32.nativemethods" -as [type])) {
    # import sendmessagetimeout from win32
    add-type -Namespace Win32 -Name NativeMethods -MemberDefinition @"
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern IntPtr SendMessageTimeout(
   IntPtr hWnd, uint Msg, UIntPtr wParam, string lParam,
   uint fuFlags, uint uTimeout, out UIntPtr lpdwResult);
"@
}

$HWND_BROADCAST = [intptr]0xffff;
$WM_SETTINGCHANGE = 0x1a;
$result = [uintptr]::zero

function global:ADD-PATH
{
    [Cmdletbinding()]
    param ( 
        [parameter(Mandatory=$True, ValueFromPipeline=$True, Position=0)] 
        [string] $Folder
    )

    # See if a folder variable has been supplied.
    if (!$Folder -or $Folder -eq "" -or $Folder -eq $null) { 
        throw 'No Folder Supplied. $ENV:PATH Unchanged'
    }

    # Get the current search path from the environment keys in the registry.
    $oldPath=$(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH).Path

    # See if the new Folder is already in the path.
    if ($oldPath | Select-String -SimpleMatch $Folder){ 
        return 'Folder already within $ENV:PATH' 
    }

    # Set the New Path and add the ; in front
    $newPath=$oldPath+';'+$Folder
    Set-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH -Value $newPath -ErrorAction Stop

    # Show our results back to the world
    return 'This is the new PATH content: '+$newPath

    # notify all windows of environment block change
    [win32.nativemethods]::SendMessageTimeout($HWND_BROADCAST, $WM_SETTINGCHANGE, [uintptr]::Zero, "Environment", 2, 5000, [ref]$result)
}

function global:REMOVE-PATH {
    [Cmdletbinding()]
    param ( 
        [parameter(Mandatory=$True, ValueFromPipeline=$True, Position=0)]
        [String] $Folder
    )

    # See if a folder variable has been supplied.
    if (!$Folder -or $Folder -eq "" -or $Folder -eq $NULL) { 
        throw 'No Folder Supplied. $ENV:PATH Unchanged'
    }

    # add a leading ";" if missing
    if ($Folder[0] -ne ";") {
        $Folder = ";" + $Folder;
    }

    # Get the Current Search Path from the environment keys in the registry
    $newPath=$(Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH).Path

    # Find the value to remove, replace it with $NULL. If it's not found, nothing will change and you get a message.
    if ($newPath -match [regex]::Escape($Folder)) { 
        $newPath=$newPath -replace [regex]::Escape($Folder),$NULL 
    } else { 
        return "The folder you mentioned does not exist in the PATH environment" 
    }

    # Update the Environment Path
    Set-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH -Value $newPath -ErrorAction Stop

    # Show what we just did
    return 'This is the new PATH content: '+$newPath

    # notify all windows of environment block change
    [win32.nativemethods]::SendMessageTimeout($HWND_BROADCAST, $WM_SETTINGCHANGE, [uintptr]::Zero, "Environment", 2, 5000, [ref]$result)
}


# Use ADD-PATH or REMOVE-PATH accordingly.

#Anything to Add?

#Anything to Remove?

REMOVE-PATH "%_installpath_bin%"

其他回答

就像凯文说的,没有捷径可走。在大多数情况下,生成另一个CMD框更简单。更令人恼火的是,正在运行的程序也不知道这些变化(尽管IIRC可能有一个广播消息来查看此类变化的通知)。

更糟糕的是:在旧版本的Windows中,你必须先注销,然后再重新登录,才能考虑到这些变化……

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"

我在批处理脚本中使用以下代码:

if not defined MY_ENV_VAR (
    setx MY_ENV_VAR "VALUE" > nul
    set MY_ENV_VAR=VALUE
)
echo %MY_ENV_VAR%

通过在SETX之后使用SET,可以直接使用“本地”变量,而无需重新启动命令窗口。在下次运行时,将使用环境变量。

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

重新启动资源管理器为我做到了这一点,但只对新的cmd终端。

我设置路径的终端已经可以看到新的path变量了(在Windows 7中)。

taskkill /f /im explorer.exe && explorer.exe