Question

以下测试失败，因为PowerShell对象更改了调用者进程的路径：

using System;
using System.IO;
using System.Linq;
using System.Management.Automation;
using Microsoft.VisualStudio.TestTools.UnitTesting;


namespace Helpers.Tests.ShellHelper {
    [TestClass]
    public class PowerShellEnvAlteration_Tests {
        [TestMethod]
        public void TestPath() {
            var searchTarget = @"C:\LandingZone";

            using (PowerShell powerShell = PowerShell.Create()) {
                powerShell.Runspace.SessionStateProxy.SetVariable("env:Path",
                    $"{searchTarget}{Path.PathSeparator}{Environment.GetEnvironmentVariable("PATH")}");
            }

            var pathDirs = Environment.GetEnvironmentVariable("PATH").Split(Path.PathSeparator);
            Assert.IsFalse(pathDirs.Contains(searchTarget));
        }
    }
}

如何预防？是否可以完全隔离此PowerShell对象/执行？

Answer 1

PetSerAl在评论中提供了关键指针：

由于环境变量本质上是[整个] 进程范围，因此您需要进程外运行空间< / strong>以获得所需的行为。

相比之下，PowerShell.Create()本身没有通过结果实例的.Runspace属性来显式分配运行空间，默认为进程内运行空间，并修改了环境该运行空间中的变量，也同样会影响在同一进程中运行的调用方。

要修改代码以使用进程外运行空间，请执行以下操作：

// ... using System.Management.Automation.Runspaces; // ... // Create an out-of-process runspace... using (var runspace = RunspaceFactory.CreateOutOfProcessRunspace(null)) { runspace.Open(); // ... open it ... using (PowerShell powerShell = PowerShell.Create()) { powerShell.Runspace = runspace; // ... and assign it to the PowerShell instance. // Now setting $env:PATH only takes effect for the separate process // in which the runspace is hosted. // Note: `powerShell.Runspace.SessionStateProxy.SetVariable("env:Path", ...)` does // does NOT work with OUT-OF-PROCESS runspaces, so a call to // `Set-Item env:PATH ...` is used to modify the other process' PATH env. var. // (Environment.SetEnvironmentVariable() is NOT an option, because // it would modify the *calling* process' environment). powerShell.AddCommand("Set-Item") .AddParameter("LiteralPath", "env:Path") .AddParameter("Value", $"{searchTarget}{Path.PathSeparator}{Environment.GetEnvironmentVariable("Path")}") .Invoke(); powerShell.Commands.Clear(); // ... } }

注意：上面使用了对Set-Item env:Path ...的调用，以便在进程外运行空间中修改$env:PATH，因为正如PetSerAl指出的，与 in-process < / em>运行空间，使用powerShell.Runspace.SessionStateProxy.SetVariable("env:Path", ...)会创建一个字面名为env:Path的 PowerShell 变量，而不是在Windows上修改 environment 变量PATH PowerShell v5.1 / PowerShell Core 6.2.0-preview.3;参见this GitHub issue

如何防止PowerShell更改环境变量？

1 个答案: