René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Process objects created with Start-Process -NoNewWindow and/or -RedirectStandard* never report their exit code on Windows.","articleBody":"Note:\r\n\r\n* The problem only surfaces on Windows.\r\n* The problem does _not_ occur when you use `-Wait` in addition to `-PassThru`  as opposed to a separate `Wait-Process` call.\r\n  * _Update_: Per #20400, the problem now (PowerShell 7.4.0-preview.5) also surfaces when `-Wait` _is_ used.    \r\n\r\n**Workaround**:\r\n\r\nPer https://github.com/PowerShell/PowerShell/issues/20716#issuecomment-1817967688, the workaround is to cache the process handle before calling `Wait-Process` / `.WaitForExit()`:\r\n\r\n```powershell\r\n$p = Start-Process cmd -args '/c', 'ver' -PassThru -NoNewWindow\r\n$dummy = $p.Handle # WORKAROUND: use a dummy variable to cache the handle\r\nWait-Process -id $p.Id\r\n\"Exit code: [$($p.ExitCode)]\"  # Now the exit code is reported.\r\n```\r\n\r\nSteps to reproduce\r\n------------------\r\n\r\nOn Windows:\r\n\r\n```powershell\r\n$p = Start-Process cmd -args '/c', 'ver' -PassThru -NoNewWindow\r\nWait-Process -id $p.Id\r\n\"Exit code: [$($p.ExitCode)]\"\r\n```\r\n\r\nNote that the problem only occurs when `-NoNewWindows` and /or any of the `-RedirectStandard*` parameters are present.\r\n\r\nInserting a `$p.WaitForExit()` call after the `Wait-Process` call, as suggested [in the docs](https://msdn.microsoft.com/en-us/library/system.diagnostics.process.exitcode%28v=vs.110%29.aspx?f=255\u0026MSPPError=-2147217396) to ensure that `.ExitCode` has a value (which should be the equivalent of `Wait-Process`), doesn't help.\r\n\r\nExpected behavior\r\n-----------------\r\n\r\n```none\r\n\r\nMicrosoft Windows [Version 10.0.15063]\r\nExit code: [0]\r\n```\r\n\r\n`$ps.ExitCode` should contain `0`, given that the `cmd` command reports exit code `0`.\r\n\r\nActual behavior\r\n---------------\r\n\r\n```none\r\n\r\nMicrosoft Windows [Version 10.0.15063]\r\nExit code: []\r\n```\r\n\r\nNote how `$ps.ExitCode` is unexpectedly stringified to the empty string.\r\nAlso, even though `Get-Member` indicates that the property's date type is `[int]`, `$null -eq $ps.ExitCode` is `$true`.\r\n\r\nThis suggests that an exception is occurring behind the scenes, which PowerShell quietly ignores.\r\n\r\nAn exception when accessing `.ExitCode` should only occur if the process hasn't exited yet, however, which is at odds with having used `Wait-Process` and `$p.HasExited` indicating `$true`.\r\n\r\n\r\n\r\n\r\nEnvironment data\r\n----------------\r\n\r\n\u003c!-- provide the output of $PSVersionTable --\u003e\r\n\r\n```powershell\r\nPowerShell Core v6.0.0-beta.9 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)\r\nWindows PowerShell v5.1.15063.674 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)\r\n```\r\n","author":{"url":"https://github.com/mklement0","@type":"Person","name":"mklement0"},"datePublished":"2017-11-11T18:33:36.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":9},"url":"https://github.com/5421/PowerShell/issues/5421"}