René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"pwsh.exe writes error messages to stdout when only stdout is redirected","articleBody":"### Prerequisites\n\n- [x] Write a descriptive title.\n- [x] Make sure you are able to repro it on the [latest released version](https://github.com/PowerShell/PowerShell/releases)\n- [x] Search the existing issues.\n- [x] Refer to the [FAQ](https://github.com/PowerShell/PowerShell/blob/master/docs/FAQ.md).\n- [x] Refer to [Differences between Windows PowerShell 5.1 and PowerShell](https://learn.microsoft.com/powershell/scripting/whats-new/differences-from-windows-powershell).\n\n### Steps to reproduce\n\nExecute these commands in cmd.exe:\n```\n1\u003eoutfile pwsh.exe -Command \"Write-Error TEST\"\ntype outfile\n```\n\n\n### Expected behavior\n\n```console\nC:\\temp\u003e1\u003eoutfile pwsh.exe -Command \"Write-Error TEST\"\nWrite-Error: TEST\n\nC:\\temp\u003etype outfile\n\nC:\\temp\u003e\n```\n\n### Actual behavior\n\n```console\nC:\\temp\u003e1\u003eoutfile pwsh.exe -Command \"Write-Error TEST\"\n\nC:\\temp\u003etype outfile\nWrite-Error: TEST\n\nC:\\temp\u003e\n```\n\n### Error details\n\n```console\n\n```\n\n### Environment data\n\n```powershell\nName                           Value\n----                           -----\nPSVersion                      7.5.4\nPSEdition                      Core\nGitCommitId                    7.5.4\nOS                             Microsoft Windows 10.0.19044\nPlatform                       Win32NT\nPSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}\nPSRemotingProtocolVersion      2.3\nSerializationVersion           1.1.0.1\nWSManStackVersion              3.0\n```\n\n### Visuals\n\nI'm executing pwsh in a cmd.exe console. When stdout is redirected to a file but stderr is not redirected, pwsh writes error messages to the file, while it should print the error in the cmd window. \nWhen stdout and stderr are both redirected or neither redirected, the behavior seems correct.\n\n```\nC:\\temp\u003epwsh.exe -Command \"Write-Error TEST\"\nWrite-Error: TEST        \u003c= This line is red in color\n\nC:\\temp\u003e1\u003eoutfile pwsh.exe -Command \"Write-Error TEST\"\n\nC:\\temp\u003etype outfile\nWrite-Error: TEST        \u003c= This line is red in color\n\nC:\\temp\u003e1\u003eoutfile 2\u003eerrfile pwsh.exe -Command \"Write-Error TEST\"\n\nC:\\temp\u003etype outfile\n\nC:\\temp\u003etype errfile\nWrite-Error: TEST        \u003c= This line is red in color\n\nC:\\temp\u003e\n```","author":{"url":"https://github.com/zwhfly","@type":"Person","name":"zwhfly"},"datePublished":"2026-01-09T10:18:20.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":1},"url":"https://github.com/26675/PowerShell/issues/26675"}