{"record":{"id":"5fc7af7270b89c12","repo":"pemistahl/grex","slug":"permission-denied-the-specified-file-could-not-be-opened","errorCode":null,"errorMessage":"Permission denied: The specified file could not be opened","messagePattern":"Permission denied: The specified file could not be opened","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/builder.rs","lineNumber":81,"sourceCode":"    /// The final line ending is optional.\n    ///\n    /// ⚠ Panics if:\n    /// - the file cannot be found\n    /// - the file's encoding is not valid UTF-8 data\n    /// - the file cannot be opened because of conflicting permissions\n    pub fn from_file<T: Into<PathBuf>>(file_path: T) -> Self {\n        match std::fs::read_to_string(file_path.into()) {\n            Ok(file_content) => Self {\n                test_cases: file_content.lines().map(|it| it.to_string()).collect_vec(),\n                config: RegExpConfig::new(),\n            },\n            Err(error) => match error.kind() {\n                ErrorKind::NotFound => panic!(\"The specified file could not be found\"),\n                ErrorKind::InvalidData => {\n                    panic!(\"The specified file's encoding is not valid UTF-8\")\n                }\n                ErrorKind::PermissionDenied => {\n                    panic!(\"Permission denied: The specified file could not be opened\")\n                }\n                _ => panic!(\"{}\", error),\n            },\n        }\n    }\n\n    /// Converts any Unicode decimal digit to character class `\\d`.\n    ///\n    /// This method takes precedence over\n    /// [`with_conversion_of_words`](Self::with_conversion_of_words) if both are set.\n    /// Decimal digits are converted to `\\d`, the remaining word characters to `\\w`.\n    ///\n    /// This method takes precedence over\n    /// [`with_conversion_of_non_whitespace`](Self::with_conversion_of_non_whitespace) if both are set.\n    /// Decimal digits are converted to `\\d`, the remaining non-whitespace characters to `\\S`.\n    pub fn with_conversion_of_digits(&mut self) -> &mut Self {\n        self.config.is_digit_converted = true;\n        self","sourceCodeStart":63,"sourceCodeEnd":99,"githubUrl":"https://github.com/pemistahl/grex/blob/99cc347707375e00514f938b76d885a201dfc110/src/builder.rs#L63-L99","documentation":"RegExpBuilder::from_file panics with 'Permission denied: The specified file could not be opened' when std::fs::read_to_string returns an io::Error of kind PermissionDenied. The process lacks read access to the file (or a directory on its path), so the builder cannot proceed and aborts.","triggerScenarios":"Calling from_file on a file without read permission bits for the current user; reading inside a container/CI as a non-root user; the parent directory lacking execute (traverse) permission; macOS sandbox or Windows ACLs blocking access.","commonSituations":"Files created by root in Docker then read by an unprivileged service user; secrets mounted with 0600 owned by another user; CI artifacts with restrictive modes.","solutions":["Fix file permissions (chmod a+r file or chown to the running user) and retry","Run the process as a user/group that has read access to the file","Check std::fs::metadata and attempt a probe read (File::open) before calling from_file to fail with a friendlier message"],"exampleFix":"// before\nlet builder = RegExpBuilder::from_file(\"/var/secure/examples.txt\");\n// after\nlet file = std::fs::File::open(\"/var/secure/examples.txt\")\n    .map_err(|e| format!(\"cannot open examples file: {}\", e))?;\ndrop(file);\nlet builder = RegExpBuilder::from_file(\"/var/secure/examples.txt\");","handlingStrategy":"validation","validationCode":"match std::fs::File::open(path) {\n    Ok(_) => {},\n    Err(e) if e.kind() == std::io::ErrorKind::PermissionDenied =>\n        return Err(anyhow!(\"no read permission for {}\", path.display())),\n    Err(e) => return Err(e.into()),\n}","typeGuard":null,"tryCatchPattern":"std::panic::catch_unwind(|| RegExpBuilder::from_file(path))\n    .map_err(|_| format!(\"permission denied reading {} — check file ownership/permissions\", path.display()))","preventionTips":["Run the process as a user with read access to input files","Check file mode/ownership in deployment scripts before launch","Avoid 0600/root-owned files for shared input data"],"tags":["panic","io","permissions"],"backgroundTag":"permission-denied","analyzedSha":"99cc347707375e00514f938b76d885a201dfc110","analyzedAt":"2026-09-13T15:42:56.144Z","contentChangedAt":"2026-09-13T15:42:56.144Z","schemaVersion":2},"datasetVersion":"2026-09-15T23:17:13.987Z"}