René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Some scripts / files with wildcard metacharacter [ in the file name or path cannot be invoked or redirected to","articleBody":"\u003csup\u003eEdited for the current status as of PowerShell Core 7.3.0-preview.4\u003c/sup\u003e\r\n\r\nNote: \r\n\r\n* Originally, this issue was also about the inability to _execute_ files whose literal names happen to be syntactically invalid wildcard patterns. \r\n\r\n* This execution aspect was _partially_ fixed in #9202 (but wasn't back-ported to the currently stable version, v6.2.3)\r\n  * Invocation by wildcard pattern still works as a fallback, but paths with `[` and `]` that exist _literally_ now take precedence.\r\n  * Therefore, **if no literal match is present, you may still end up invoking an unrelated file by accident**, which is problematic (e.g., if `a.ps1` is present in the current dir. and `.\\[ab].ps1` is invoked, with no file _literally_ named `[ab].ps1` present, `.\\a.ps1` is executed instead.)\r\n\r\nSeemingly, all external-executable invocation methods ( `.`, `\u0026`, `Start-Process`, `powershell -File`) as well as redirections `\u003e` / `\u003e\u003e` mistakenly interpret script / file paths as _wildcard patterns_, and if  a path that contains `[` happens not contain a syntactically valid range expression, invocation and redirection _break_ (in _Windows PowerShell_, no longer in PowerShell Core, except with `Start-Process`) or can end up accidentally targeting an unrelated executable.\r\n\r\n* In other words: The problem _sometimes_ occurs, unless each instance of `[` happens to be part of a _valid_ range expression; e.g., `a[b]` (valid) vs. `a[b` (invalid); curiously, however, the equally invalid `b[b` does not.\r\n\r\n* But even with a syntactically valid range expression - and some invalid ones - the behavior is unexpected:\r\n\r\n  * `'foo' \u003e 'file[1].txt'` attempts wildcard matching and complains, `Cannot perform operation because the wildcard path file[1].txt did not resolve to a file.`\r\n    * Attempting _escaping_ then inappropriately retains the escape characters - see #9475\r\n\r\n* Attempting to invoke (open) such a file fails quietly, even with escaping (run `New-Item file[1].txt` first):\r\n  * `./file[1].txt` ... quiet no-op\r\n  * ``./file`[1`].txt`` ... quiet no-op\r\n  * If you created a `.ps1` file named, say, `file[1].ps1` (`'\"hi\"' | Set-Content -LiteralPath file[1].ps1`):\r\n    * Invocation with an explicit path unexpectedly only works if `.ps1` is also specified.\r\n    * Invocation via $env:PATH doesn't work at all - neither with or without `.ps1`\r\n\r\n**Fundamentally, external-executable / redirection output paths should be treated as _literals_ in these situations.**\r\nSee [this comment](https://github.com/PowerShell/PowerShell/issues/17106#issuecomment-1088755835) for a discussion and an overview of related issues.\r\n\r\nOriginal tests below.\r\n\r\nSteps to reproduce\r\n------------------\r\n\r\nRun the following Pester tests.\r\n\r\n```powershell\r\nDescribe \"Redirection with and invocation of literal file paths that are invalid as wildcard patterns\" {\r\n\r\n  BeforeAll {\r\n    Push-Location testdrive:\\\r\n    $f1 = './t[1.ps1'\r\n    $f2 = './t[1.txt'\r\n    New-Item -Type File $f1 -Value \"'hi'\"\r\n  }\r\n\r\n # Passes now, due to fix in #9202\r\n  It \"Script file can be dot-sourced.\" {\r\n    . $f1 | Should -Be 'hi'\r\n  }\r\n\r\n # Passes now, due to fix in #9202\r\n  It \"Script file can be called.\" {\r\n    \u0026 $f1 | Should -Be 'hi'\r\n  }\r\n\r\n # Passes now, due to fix in #9202\r\n  It \"Script file can be called via CLI with -File\" {\r\n    pwsh -noprofile -file $f1 | Should -Be 'hi'\r\n  }\r\n\r\n  It \"Redirection works with new file (\u003e)\" {\r\n    \u0026 { 'hi' \u003e $f2; Get-Content -LiteralPath $f2 } | Should -Be 'hi'\r\n  }\r\n\r\n  It \"Redirection works with existing file (\u003e)\" {\r\n    New-Item -Force -Type File $f2\r\n    \u0026 { 'hi' \u003e $f2; Get-Content -LiteralPath $f2 } | Should -Be 'hi'\r\n  }\r\n\r\n  It \"File path is passed correctly to external programs\" {\r\n    if ($IsWindows) {\r\n      cmd /c type ($f1 -replace '/', '\\') | Should -Be \"'hi'\"\r\n    } else {\r\n      /bin/cat $f1 | Should -Be \"'hi'\"\r\n    }\r\n  }\r\n\r\n  AfterAll {\r\n    Pop-Location\r\n  }\r\n}\r\n```\r\n\r\nExpected behavior\r\n-----------------\r\n\r\nAll tests should pass.\r\n\r\nActual behavior\r\n---------------\r\n\r\nThe `\u003e` tests fail on all platforms.\r\n\r\nIn v6.2.3, the invocation tests fail too.\r\n\r\nEnvironment data\r\n----------------\r\n\r\n```powershell\r\nPowerShell Core 7.0.0-preview.5\r\n```\r\n\r\nOriginally reported for PowerShell Core v6.0.0-beta.7.\r\n","author":{"url":"https://github.com/mklement0","@type":"Person","name":"mklement0"},"datePublished":"2017-08-31T16:34:25.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":27},"url":"https://github.com/4726/PowerShell/issues/4726"}