packages/flutter_tools/lib/src/base/os.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'package:archive/archive.dart';
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
 import 'package:process/process.dart';

 import 'common.dart';
 import 'file_system.dart';
 import 'io.dart';
 import 'logger.dart';
 import 'platform.dart';
 import 'process.dart';

 abstract class OperatingSystemUtils {
   factory OperatingSystemUtils({
     required FileSystem fileSystem,
     required Logger logger,
     required Platform platform,
     required ProcessManager processManager,
   }) {
     if (platform.isWindows) {
       return _WindowsUtils(
         fileSystem: fileSystem,
         logger: logger,
         platform: platform,
         processManager: processManager,
       );
     } else if (platform.isMacOS) {
       return _MacOSUtils(
         fileSystem: fileSystem,
         logger: logger,
         platform: platform,
         processManager: processManager,
       );
     } else if (platform.isLinux) {
       return _LinuxUtils(
         fileSystem: fileSystem,
         logger: logger,
         platform: platform,
         processManager: processManager,
       );
     } else {
       return _PosixUtils(
         fileSystem: fileSystem,
         logger: logger,
         platform: platform,
         processManager: processManager,
       );
     }
   }

   OperatingSystemUtils._private({
     required FileSystem fileSystem,
     required Logger logger,
     required Platform platform,
     required ProcessManager processManager,
   }) : _fileSystem = fileSystem,
        _logger = logger,
        _platform = platform,
        _processManager = processManager,
        _processUtils = ProcessUtils(
         logger: logger,
         processManager: processManager,
       );

   @visibleForTesting
   static final GZipCodec gzipLevel1 = GZipCodec(level: 1);

   final FileSystem _fileSystem;
   final Logger _logger;
   final Platform _platform;
   final ProcessManager _processManager;
   final ProcessUtils _processUtils;

   /// Make the given file executable. This may be a no-op on some platforms.
   void makeExecutable(File file);

   /// Updates the specified file system [entity] to have the file mode
   /// bits set to the value defined by [mode], which can be specified in octal
   /// (e.g. `644`) or symbolically (e.g. `u+x`).
   ///
   /// On operating systems that do not support file mode bits, this will be a
   /// no-op.
   void chmod(FileSystemEntity entity, String mode);

   /// Return the path (with symlinks resolved) to the given executable, or null
   /// if `which` was not able to locate the binary.
   File? which(String execName) {
     final List<File> result = _which(execName);
     if (result == null || result.isEmpty) {
       return null;
     }
     return result.first;
   }

   /// Return a list of all paths to `execName` found on the system. Uses the
   /// PATH environment variable.
   List<File> whichAll(String execName) => _which(execName, all: true);

   /// Return the File representing a new pipe.
   File makePipe(String path);

   void unzip(File file, Directory targetDirectory);

   void unpack(File gzippedTarFile, Directory targetDirectory);

   /// Compresses a stream using gzip level 1 (faster but larger).
   Stream<List<int>> gzipLevel1Stream(Stream<List<int>> stream) {
     return stream.cast<List<int>>().transform<List<int>>(gzipLevel1.encoder);
   }

   /// Returns a pretty name string for the current operating system.
   ///
   /// If available, the detailed version of the OS is included.
   String get name {
     const Map<String, String> osNames = <String, String>{
       'macos': 'Mac OS',
       'linux': 'Linux',
       'windows': 'Windows',
     };
     final String osName = _platform.operatingSystem;
     return osNames[osName] ?? osName;
   }

   HostPlatform get hostPlatform;

   List<File> _which(String execName, { bool all = false });

   /// Returns the separator between items in the PATH environment variable.
   String get pathVarSeparator;

   /// Returns an unused network port.
   ///
   /// Returns 0 if an unused port cannot be found.
   ///
   /// The port returned by this function may become used before it is bound by
   /// its intended user.
   Future<int> findFreePort({bool ipv6 = false}) async {
     int port = 0;
     ServerSocket? serverSocket;
     final InternetAddress loopback =
         ipv6 ? InternetAddress.loopbackIPv6 : InternetAddress.loopbackIPv4;
     try {
       serverSocket = await ServerSocket.bind(loopback, 0);
       port = serverSocket.port;
     } on SocketException catch (e) {
       // If ipv4 loopback bind fails, try ipv6.
       if (!ipv6) {
         return findFreePort(ipv6: true);
       }
       _logger.printTrace('findFreePort failed: $e');
     } on Exception catch (e) {
       // Failures are signaled by a return value of 0 from this function.
       _logger.printTrace('findFreePort failed: $e');
     } finally {
       if (serverSocket != null) {
         await serverSocket.close();
       }
     }
     return port;
   }
 }

 class _PosixUtils extends OperatingSystemUtils {
   _PosixUtils({
     required super.fileSystem,
     required super.logger,
     required super.platform,
     required super.processManager,
   }) : super._private();

   @override
   void makeExecutable(File file) {
     chmod(file, 'a+x');
   }

   @override
   void chmod(FileSystemEntity entity, String mode) {
     // Errors here are silently ignored (except when tracing).
     try {
       final ProcessResult result = _processManager.runSync(
         <String>['chmod', mode, entity.path],
       );
       if (result.exitCode != 0) {
         _logger.printTrace(
           'Error trying to run "chmod $mode ${entity.path}":\n'
           '  exit code: ${result.exitCode}\n'
           '  stdout: ${result.stdout.toString().trimRight()}\n'
           '  stderr: ${result.stderr.toString().trimRight()}'
         );
       }
     } on ProcessException catch (error) {
       _logger.printTrace(
         'Error trying to run "chmod $mode ${entity.path}": $error',
       );
     }
   }

   @override
   List<File> _which(String execName, { bool all = false }) {
     final List<String> command = <String>[
       'which',
       if (all) '-a',
       execName,
     ];
     final ProcessResult result = _processManager.runSync(command);
     if (result.exitCode != 0) {
       return const <File>[];
     }
     final String stdout = result.stdout as String;
     return stdout.trim().split('\n').map<File>(
       (String path) => _fileSystem.file(path.trim()),
     ).toList();
   }

   // unzip -o -q zipfile -d dest
   @override
   void unzip(File file, Directory targetDirectory) {
     if (!_processManager.canRun('unzip')) {
       // unzip is not available. this error message is modeled after the download
       // error in bin/internal/update_dart_sdk.sh
       String message = 'Please install unzip.';
       if (_platform.isMacOS) {
         message = 'Consider running "brew install unzip".';
       } else if (_platform.isLinux) {
         message = 'Consider running "sudo apt-get install unzip".';
       }
       throwToolExit(
         'Missing "unzip" tool. Unable to extract ${file.path}.\n$message'
       );
     }
     _processUtils.runSync(
       <String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
       throwOnError: true,
       verboseExceptions: true,
     );
   }

   // tar -xzf tarball -C dest
   @override
   void unpack(File gzippedTarFile, Directory targetDirectory) {
     _processUtils.runSync(
       <String>['tar', '-xzf', gzippedTarFile.path, '-C', targetDirectory.path],
       throwOnError: true,
     );
   }

   @override
   File makePipe(String path) {
     _processUtils.runSync(
       <String>['mkfifo', path],
       throwOnError: true,
     );
     return _fileSystem.file(path);
   }

   @override
   String get pathVarSeparator => ':';

   HostPlatform? _hostPlatform;

   @override
   HostPlatform get hostPlatform {
     if (_hostPlatform == null) {
       final RunResult hostPlatformCheck = _processUtils.runSync(<String>['uname', '-m']);
       // On x64 stdout is "uname -m: x86_64"
       // On arm64 stdout is "uname -m: aarch64, arm64_v8a"
       if (hostPlatformCheck.exitCode != 0) {
         _hostPlatform = HostPlatform.linux_x64;
         _logger.printError(
           'Encountered an error trying to run "uname -m":\n'
           '  exit code: ${hostPlatformCheck.exitCode}\n'
           '  stdout: ${hostPlatformCheck.stdout.trimRight()}\n'
           '  stderr: ${hostPlatformCheck.stderr.trimRight()}\n'
           'Assuming host platform is ${getNameForHostPlatform(_hostPlatform!)}.',
         );
       } else if (hostPlatformCheck.stdout.trim().endsWith('x86_64')) {
         _hostPlatform = HostPlatform.linux_x64;
       } else {
         // We default to ARM if it's not x86_64 and we did not get an error.
         _hostPlatform = HostPlatform.linux_arm64;
       }
     }
     return _hostPlatform!;
   }
 }

 class _LinuxUtils extends _PosixUtils {
   _LinuxUtils({
     required super.fileSystem,
     required super.logger,
     required super.platform,
     required super.processManager,
   });

   String? _name;

   @override
   String get name {
     if (_name == null) {
       const String prettyNameKey = 'PRETTY_NAME';
       // If "/etc/os-release" doesn't exist, fallback to "/usr/lib/os-release".
       final String osReleasePath = _fileSystem.file('/etc/os-release').existsSync()
         ? '/etc/os-release'
         : '/usr/lib/os-release';
       String prettyName;
       String kernelRelease;
       try {
         final String osRelease = _fileSystem.file(osReleasePath).readAsStringSync();
         prettyName = _getOsReleaseValueForKey(osRelease, prettyNameKey);
       } on Exception catch (e) {
         _logger.printTrace('Failed obtaining PRETTY_NAME for Linux: $e');
         prettyName = '';
       }
       try {
         // Split the operating system version which should be formatted as
         // "Linux kernelRelease build", by spaces.
         final List<String> osVersionSplitted = _platform.operatingSystemVersion.split(' ');
         if (osVersionSplitted.length < 3) {
           // The operating system version didn't have the expected format.
           // Initialize as an empty string.
           kernelRelease = '';
         } else {
           kernelRelease = ' ${osVersionSplitted[1]}';
         }
       } on Exception catch (e) {
         _logger.printTrace('Failed obtaining kernel release for Linux: $e');
         kernelRelease = '';
       }
       _name = '${prettyName.isEmpty ? super.name : prettyName}$kernelRelease';
     }
     return _name!;
   }

   String _getOsReleaseValueForKey(String osRelease, String key) {
     final List<String> osReleaseSplitted = osRelease.split('\n');
     for (String entry in osReleaseSplitted) {
       entry = entry.trim();
       final List<String> entryKeyValuePair = entry.split('=');
       if(entryKeyValuePair[0] == key) {
         final String value =  entryKeyValuePair[1];
         // Remove quotes from either end of the value if they exist
         final String quote = value[0];
         if (quote == "'" || quote == '"') {
           return value.substring(0, value.length - 1).substring(1);
         } else {
           return value;
         }
       }
     }
     return '';
   }
 }

 class _MacOSUtils extends _PosixUtils {
   _MacOSUtils({
     required super.fileSystem,
     required super.logger,
     required super.platform,
     required super.processManager,
   });

   String? _name;

   @override
   String get name {
     if (_name == null) {
       final List<RunResult> results = <RunResult>[
         _processUtils.runSync(<String>['sw_vers', '-productName']),
         _processUtils.runSync(<String>['sw_vers', '-productVersion']),
         _processUtils.runSync(<String>['sw_vers', '-buildVersion']),
         _processUtils.runSync(<String>['uname', '-m']),
       ];
       if (results.every((RunResult result) => result.exitCode == 0)) {
         String osName = getNameForHostPlatform(hostPlatform);
         // If the script is running in Rosetta, "uname -m" will return x86_64.
         if (hostPlatform == HostPlatform.darwin_arm64 && results[3].stdout.contains('x86_64')) {
           osName = '$osName (Rosetta)';
         }
         _name =
             '${results[0].stdout.trim()} ${results[1].stdout.trim()} ${results[2].stdout.trim()} $osName';
       }
       _name ??= super.name;
     }
     return _name!;
   }

   // On ARM returns arm64, even when this process is running in Rosetta.
   @override
   HostPlatform get hostPlatform {
     if (_hostPlatform == null) {
       String? sysctlPath;
       if (which('sysctl') == null) {
         // Fallback to known install locations.
         for (final String path in <String>[
           '/usr/sbin/sysctl',
           '/sbin/sysctl',
         ]) {
           if (_fileSystem.isFileSync(path)) {
             sysctlPath = path;
           }
         }
       } else {
         sysctlPath = 'sysctl';
       }

       if (sysctlPath == null) {
         throwToolExit('sysctl not found. Try adding it to your PATH environment variable.');
       }
       final RunResult arm64Check =
           _processUtils.runSync(<String>[sysctlPath, 'hw.optional.arm64']);
       // On arm64 stdout is "sysctl hw.optional.arm64: 1"
       // On x86 hw.optional.arm64 is unavailable and exits with 1.
       if (arm64Check.exitCode == 0 && arm64Check.stdout.trim().endsWith('1')) {
         _hostPlatform = HostPlatform.darwin_arm64;
       } else {
         _hostPlatform = HostPlatform.darwin_x64;
       }
     }
     return _hostPlatform!;
   }

   // unzip, then rsync
   @override
   void unzip(File file, Directory targetDirectory) {
     if (!_processManager.canRun('unzip')) {
       // unzip is not available. this error message is modeled after the download
       // error in bin/internal/update_dart_sdk.sh
       throwToolExit('Missing "unzip" tool. Unable to extract ${file.path}.\nConsider running "brew install unzip".');
     }
     if (_processManager.canRun('rsync')) {
       final Directory tempDirectory = _fileSystem.systemTempDirectory.createTempSync('flutter_${file.basename}.');
       try {
         // Unzip to a temporary directory.
         _processUtils.runSync(
           <String>['unzip', '-o', '-q', file.path, '-d', tempDirectory.path],
           throwOnError: true,
           verboseExceptions: true,
         );
         for (final FileSystemEntity unzippedFile in tempDirectory.listSync(followLinks: false)) {
           // rsync --delete the unzipped files so files removed from the archive are also removed from the target.
           // Add the '-8' parameter to avoid mangling filenames with encodings that do not match the current locale.
           _processUtils.runSync(
             <String>['rsync', '-8', '-av', '--delete', unzippedFile.path, targetDirectory.path],
             throwOnError: true,
             verboseExceptions: true,
           );
         }
       } finally {
         tempDirectory.deleteSync(recursive: true);
       }
     } else {
       // Fall back to just unzipping.
       _logger.printTrace('Unable to find rsync, falling back to direct unzipping.');
       _processUtils.runSync(
         <String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
         throwOnError: true,
         verboseExceptions: true,
       );
     }
   }
 }

 class _WindowsUtils extends OperatingSystemUtils {
   _WindowsUtils({
     required super.fileSystem,
     required super.logger,
     required super.platform,
     required super.processManager,
   }) : super._private();

   @override
   HostPlatform hostPlatform = HostPlatform.windows_x64;

   @override
   void makeExecutable(File file) {}

   @override
   void chmod(FileSystemEntity entity, String mode) {}

   @override
   List<File> _which(String execName, { bool all = false }) {
     if (!_processManager.canRun('where')) {
       // `where` could be missing if system32 is not on the PATH.
       throwToolExit(
         'Cannot find the executable for `where`. This can happen if the System32 '
         r'folder (e.g. C:\Windows\System32 ) is removed from the PATH environment '
         'variable. Ensure that this is present and then try again after restarting '
         'the terminal and/or IDE.'
       );
     }
     // `where` always returns all matches, not just the first one.
     final ProcessResult result = _processManager.runSync(<String>['where', execName]);
     if (result.exitCode != 0) {
       return const <File>[];
     }
     final List<String> lines = (result.stdout as String).trim().split('\n');
     if (all) {
       return lines.map<File>((String path) => _fileSystem.file(path.trim())).toList();
     }
     return <File>[_fileSystem.file(lines.first.trim())];
   }

   @override
   void unzip(File file, Directory targetDirectory) {
     final Archive archive = ZipDecoder().decodeBytes(file.readAsBytesSync());
     _unpackArchive(archive, targetDirectory);
   }

   @override
   void unpack(File gzippedTarFile, Directory targetDirectory) {
     final Archive archive = TarDecoder().decodeBytes(
       GZipDecoder().decodeBytes(gzippedTarFile.readAsBytesSync()),
     );
     _unpackArchive(archive, targetDirectory);
   }

   void _unpackArchive(Archive archive, Directory targetDirectory) {
     for (final ArchiveFile archiveFile in archive.files) {
       // The archive package doesn't correctly set isFile.
       if (!archiveFile.isFile || archiveFile.name.endsWith('/')) {
         continue;
       }

       final File destFile = _fileSystem.file(
         _fileSystem.path.canonicalize(
           _fileSystem.path.join(
             targetDirectory.path,
             archiveFile.name,
           ),
         ),
       );

       // Validate that the destFile is within the targetDirectory we want to
       // extract to.
       //
       // See https://snyk.io/research/zip-slip-vulnerability for more context.
       final String destinationFileCanonicalPath = _fileSystem.path.canonicalize(
         destFile.path,
       );
       final String targetDirectoryCanonicalPath = _fileSystem.path.canonicalize(
         targetDirectory.path,
       );
       if (!destinationFileCanonicalPath.startsWith(targetDirectoryCanonicalPath)) {
         throw StateError(
           'Tried to extract the file $destinationFileCanonicalPath outside of the '
           'target directory $targetDirectoryCanonicalPath',
         );
       }

       if (!destFile.parent.existsSync()) {
         destFile.parent.createSync(recursive: true);
       }
       destFile.writeAsBytesSync(archiveFile.content as List<int>);
     }
   }

   @override
   File makePipe(String path) {
     throw UnsupportedError('makePipe is not implemented on Windows.');
   }

   String? _name;

   @override
   String get name {
     if (_name == null) {
       final ProcessResult result = _processManager.runSync(
           <String>['ver'], runInShell: true);
       if (result.exitCode == 0) {
         _name = (result.stdout as String).trim();
       } else {
         _name = super.name;
       }
     }
     return _name!;
   }

   @override
   String get pathVarSeparator => ';';
 }

 /// Find and return the project root directory relative to the specified
 /// directory or the current working directory if none specified.
 /// Return null if the project root could not be found
 /// or if the project root is the flutter repository root.
 String? findProjectRoot(FileSystem fileSystem, [ String? directory ]) {
   const String kProjectRootSentinel = 'pubspec.yaml';
   directory ??= fileSystem.currentDirectory.path;
   Directory currentDirectory = fileSystem.directory(directory).absolute;
   while (true) {
     if (currentDirectory.childFile(kProjectRootSentinel).existsSync()) {
       return currentDirectory.path;
     }
     if (!currentDirectory.existsSync() || currentDirectory.parent.path == currentDirectory.path) {
       return null;
     }
     currentDirectory = currentDirectory.parent;
   }
 }

 enum HostPlatform {
   darwin_x64,
   darwin_arm64,
   linux_x64,
   linux_arm64,
   windows_x64,
 }

 String getNameForHostPlatform(HostPlatform platform) {
   switch (platform) {
     case HostPlatform.darwin_x64:
       return 'darwin-x64';
     case HostPlatform.darwin_arm64:
       return 'darwin-arm64';
     case HostPlatform.linux_x64:
       return 'linux-x64';
     case HostPlatform.linux_arm64:
       return 'linux-arm64';
     case HostPlatform.windows_x64:
       return 'windows-x64';
   }
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'package:archive/archive.dart';
	import 'package:file/file.dart';
	import 'package:meta/meta.dart';
	import 'package:process/process.dart';

	import 'common.dart';
	import 'file_system.dart';
	import 'io.dart';
	import 'logger.dart';
	import 'platform.dart';
	import 'process.dart';

	abstract class OperatingSystemUtils {
	factory OperatingSystemUtils({
	required FileSystem fileSystem,
	required Logger logger,
	required Platform platform,
	required ProcessManager processManager,
	}) {
	if (platform.isWindows) {
	return _WindowsUtils(
	fileSystem: fileSystem,
	logger: logger,
	platform: platform,
	processManager: processManager,
	);
	} else if (platform.isMacOS) {
	return _MacOSUtils(
	fileSystem: fileSystem,
	logger: logger,
	platform: platform,
	processManager: processManager,
	);
	} else if (platform.isLinux) {
	return _LinuxUtils(
	fileSystem: fileSystem,
	logger: logger,
	platform: platform,
	processManager: processManager,
	);
	} else {
	return _PosixUtils(
	fileSystem: fileSystem,
	logger: logger,
	platform: platform,
	processManager: processManager,
	);
	}
	}

	OperatingSystemUtils._private({
	required FileSystem fileSystem,
	required Logger logger,
	required Platform platform,
	required ProcessManager processManager,
	}) : _fileSystem = fileSystem,
	_logger = logger,
	_platform = platform,
	_processManager = processManager,
	_processUtils = ProcessUtils(
	logger: logger,
	processManager: processManager,
	);

	@visibleForTesting
	static final GZipCodec gzipLevel1 = GZipCodec(level: 1);

	final FileSystem _fileSystem;
	final Logger _logger;
	final Platform _platform;
	final ProcessManager _processManager;
	final ProcessUtils _processUtils;

	/// Make the given file executable. This may be a no-op on some platforms.
	void makeExecutable(File file);

	/// Updates the specified file system [entity] to have the file mode
	/// bits set to the value defined by [mode], which can be specified in octal
	/// (e.g. `644`) or symbolically (e.g. `u+x`).
	///
	/// On operating systems that do not support file mode bits, this will be a
	/// no-op.
	void chmod(FileSystemEntity entity, String mode);

	/// Return the path (with symlinks resolved) to the given executable, or null
	/// if `which` was not able to locate the binary.
	File? which(String execName) {
	final List<File> result = _which(execName);
	if (result == null \|\| result.isEmpty) {
	return null;
	}
	return result.first;
	}

	/// Return a list of all paths to `execName` found on the system. Uses the
	/// PATH environment variable.
	List<File> whichAll(String execName) => _which(execName, all: true);

	/// Return the File representing a new pipe.
	File makePipe(String path);

	void unzip(File file, Directory targetDirectory);

	void unpack(File gzippedTarFile, Directory targetDirectory);

	/// Compresses a stream using gzip level 1 (faster but larger).
	Stream<List<int>> gzipLevel1Stream(Stream<List<int>> stream) {
	return stream.cast<List<int>>().transform<List<int>>(gzipLevel1.encoder);
	}

	/// Returns a pretty name string for the current operating system.
	///
	/// If available, the detailed version of the OS is included.
	String get name {
	const Map<String, String> osNames = <String, String>{
	'macos': 'Mac OS',
	'linux': 'Linux',
	'windows': 'Windows',
	};
	final String osName = _platform.operatingSystem;
	return osNames[osName] ?? osName;
	}

	HostPlatform get hostPlatform;

	List<File> _which(String execName, { bool all = false });

	/// Returns the separator between items in the PATH environment variable.
	String get pathVarSeparator;

	/// Returns an unused network port.
	///
	/// Returns 0 if an unused port cannot be found.
	///
	/// The port returned by this function may become used before it is bound by
	/// its intended user.
	Future<int> findFreePort({bool ipv6 = false}) async {
	int port = 0;
	ServerSocket? serverSocket;
	final InternetAddress loopback =
	ipv6 ? InternetAddress.loopbackIPv6 : InternetAddress.loopbackIPv4;
	try {
	serverSocket = await ServerSocket.bind(loopback, 0);
	port = serverSocket.port;
	} on SocketException catch (e) {
	// If ipv4 loopback bind fails, try ipv6.
	if (!ipv6) {
	return findFreePort(ipv6: true);
	}
	_logger.printTrace('findFreePort failed: $e');
	} on Exception catch (e) {
	// Failures are signaled by a return value of 0 from this function.
	_logger.printTrace('findFreePort failed: $e');
	} finally {
	if (serverSocket != null) {
	await serverSocket.close();
	}
	}
	return port;
	}
	}

	class _PosixUtils extends OperatingSystemUtils {
	_PosixUtils({
	required super.fileSystem,
	required super.logger,
	required super.platform,
	required super.processManager,
	}) : super._private();

	@override
	void makeExecutable(File file) {
	chmod(file, 'a+x');
	}

	@override
	void chmod(FileSystemEntity entity, String mode) {
	// Errors here are silently ignored (except when tracing).
	try {
	final ProcessResult result = _processManager.runSync(
	<String>['chmod', mode, entity.path],
	);
	if (result.exitCode != 0) {
	_logger.printTrace(
	'Error trying to run "chmod $mode ${entity.path}":\n'
	' exit code: ${result.exitCode}\n'
	' stdout: ${result.stdout.toString().trimRight()}\n'
	' stderr: ${result.stderr.toString().trimRight()}'
	);
	}
	} on ProcessException catch (error) {
	_logger.printTrace(
	'Error trying to run "chmod $mode ${entity.path}": $error',
	);
	}
	}

	@override
	List<File> _which(String execName, { bool all = false }) {
	final List<String> command = <String>[
	'which',
	if (all) '-a',
	execName,
	];
	final ProcessResult result = _processManager.runSync(command);
	if (result.exitCode != 0) {
	return const <File>[];
	}
	final String stdout = result.stdout as String;
	return stdout.trim().split('\n').map<File>(
	(String path) => _fileSystem.file(path.trim()),
	).toList();
	}

	// unzip -o -q zipfile -d dest
	@override
	void unzip(File file, Directory targetDirectory) {
	if (!_processManager.canRun('unzip')) {
	// unzip is not available. this error message is modeled after the download
	// error in bin/internal/update_dart_sdk.sh
	String message = 'Please install unzip.';
	if (_platform.isMacOS) {
	message = 'Consider running "brew install unzip".';
	} else if (_platform.isLinux) {
	message = 'Consider running "sudo apt-get install unzip".';
	}
	throwToolExit(
	'Missing "unzip" tool. Unable to extract ${file.path}.\n$message'
	);
	}
	_processUtils.runSync(
	<String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
	throwOnError: true,
	verboseExceptions: true,
	);
	}

	// tar -xzf tarball -C dest
	@override
	void unpack(File gzippedTarFile, Directory targetDirectory) {
	_processUtils.runSync(
	<String>['tar', '-xzf', gzippedTarFile.path, '-C', targetDirectory.path],
	throwOnError: true,
	);
	}

	@override
	File makePipe(String path) {
	_processUtils.runSync(
	<String>['mkfifo', path],
	throwOnError: true,
	);
	return _fileSystem.file(path);
	}

	@override
	String get pathVarSeparator => ':';

	HostPlatform? _hostPlatform;

	@override
	HostPlatform get hostPlatform {
	if (_hostPlatform == null) {
	final RunResult hostPlatformCheck = _processUtils.runSync(<String>['uname', '-m']);
	// On x64 stdout is "uname -m: x86_64"
	// On arm64 stdout is "uname -m: aarch64, arm64_v8a"
	if (hostPlatformCheck.exitCode != 0) {
	_hostPlatform = HostPlatform.linux_x64;
	_logger.printError(
	'Encountered an error trying to run "uname -m":\n'
	' exit code: ${hostPlatformCheck.exitCode}\n'
	' stdout: ${hostPlatformCheck.stdout.trimRight()}\n'
	' stderr: ${hostPlatformCheck.stderr.trimRight()}\n'
	'Assuming host platform is ${getNameForHostPlatform(_hostPlatform!)}.',
	);
	} else if (hostPlatformCheck.stdout.trim().endsWith('x86_64')) {
	_hostPlatform = HostPlatform.linux_x64;
	} else {
	// We default to ARM if it's not x86_64 and we did not get an error.
	_hostPlatform = HostPlatform.linux_arm64;
	}
	}
	return _hostPlatform!;
	}
	}

	class _LinuxUtils extends _PosixUtils {
	_LinuxUtils({
	required super.fileSystem,
	required super.logger,
	required super.platform,
	required super.processManager,
	});

	String? _name;

	@override
	String get name {
	if (_name == null) {
	const String prettyNameKey = 'PRETTY_NAME';
	// If "/etc/os-release" doesn't exist, fallback to "/usr/lib/os-release".
	final String osReleasePath = _fileSystem.file('/etc/os-release').existsSync()
	? '/etc/os-release'
	: '/usr/lib/os-release';
	String prettyName;
	String kernelRelease;
	try {
	final String osRelease = _fileSystem.file(osReleasePath).readAsStringSync();
	prettyName = _getOsReleaseValueForKey(osRelease, prettyNameKey);
	} on Exception catch (e) {
	_logger.printTrace('Failed obtaining PRETTY_NAME for Linux: $e');
	prettyName = '';
	}
	try {
	// Split the operating system version which should be formatted as
	// "Linux kernelRelease build", by spaces.
	final List<String> osVersionSplitted = _platform.operatingSystemVersion.split(' ');
	if (osVersionSplitted.length < 3) {
	// The operating system version didn't have the expected format.
	// Initialize as an empty string.
	kernelRelease = '';
	} else {
	kernelRelease = ' ${osVersionSplitted[1]}';
	}
	} on Exception catch (e) {
	_logger.printTrace('Failed obtaining kernel release for Linux: $e');
	kernelRelease = '';
	}
	_name = '${prettyName.isEmpty ? super.name : prettyName}$kernelRelease';
	}
	return _name!;
	}

	String _getOsReleaseValueForKey(String osRelease, String key) {
	final List<String> osReleaseSplitted = osRelease.split('\n');
	for (String entry in osReleaseSplitted) {
	entry = entry.trim();
	final List<String> entryKeyValuePair = entry.split('=');
	if(entryKeyValuePair[0] == key) {
	final String value = entryKeyValuePair[1];
	// Remove quotes from either end of the value if they exist
	final String quote = value[0];
	if (quote == "'" \|\| quote == '"') {
	return value.substring(0, value.length - 1).substring(1);
	} else {
	return value;
	}
	}
	}
	return '';
	}
	}

	class _MacOSUtils extends _PosixUtils {
	_MacOSUtils({
	required super.fileSystem,
	required super.logger,
	required super.platform,
	required super.processManager,
	});

	String? _name;

	@override
	String get name {
	if (_name == null) {
	final List<RunResult> results = <RunResult>[
	_processUtils.runSync(<String>['sw_vers', '-productName']),
	_processUtils.runSync(<String>['sw_vers', '-productVersion']),
	_processUtils.runSync(<String>['sw_vers', '-buildVersion']),
	_processUtils.runSync(<String>['uname', '-m']),
	];
	if (results.every((RunResult result) => result.exitCode == 0)) {
	String osName = getNameForHostPlatform(hostPlatform);
	// If the script is running in Rosetta, "uname -m" will return x86_64.
	if (hostPlatform == HostPlatform.darwin_arm64 && results[3].stdout.contains('x86_64')) {
	osName = '$osName (Rosetta)';
	}
	_name =
	'${results[0].stdout.trim()} ${results[1].stdout.trim()} ${results[2].stdout.trim()} $osName';
	}
	_name ??= super.name;
	}
	return _name!;
	}

	// On ARM returns arm64, even when this process is running in Rosetta.
	@override
	HostPlatform get hostPlatform {
	if (_hostPlatform == null) {
	String? sysctlPath;
	if (which('sysctl') == null) {
	// Fallback to known install locations.
	for (final String path in <String>[
	'/usr/sbin/sysctl',
	'/sbin/sysctl',
	]) {
	if (_fileSystem.isFileSync(path)) {
	sysctlPath = path;
	}
	}
	} else {
	sysctlPath = 'sysctl';
	}

	if (sysctlPath == null) {
	throwToolExit('sysctl not found. Try adding it to your PATH environment variable.');
	}
	final RunResult arm64Check =
	_processUtils.runSync(<String>[sysctlPath, 'hw.optional.arm64']);
	// On arm64 stdout is "sysctl hw.optional.arm64: 1"
	// On x86 hw.optional.arm64 is unavailable and exits with 1.
	if (arm64Check.exitCode == 0 && arm64Check.stdout.trim().endsWith('1')) {
	_hostPlatform = HostPlatform.darwin_arm64;
	} else {
	_hostPlatform = HostPlatform.darwin_x64;
	}
	}
	return _hostPlatform!;
	}

	// unzip, then rsync
	@override
	void unzip(File file, Directory targetDirectory) {
	if (!_processManager.canRun('unzip')) {
	// unzip is not available. this error message is modeled after the download
	// error in bin/internal/update_dart_sdk.sh
	throwToolExit('Missing "unzip" tool. Unable to extract ${file.path}.\nConsider running "brew install unzip".');
	}
	if (_processManager.canRun('rsync')) {
	final Directory tempDirectory = _fileSystem.systemTempDirectory.createTempSync('flutter_${file.basename}.');
	try {
	// Unzip to a temporary directory.
	_processUtils.runSync(
	<String>['unzip', '-o', '-q', file.path, '-d', tempDirectory.path],
	throwOnError: true,
	verboseExceptions: true,
	);
	for (final FileSystemEntity unzippedFile in tempDirectory.listSync(followLinks: false)) {
	// rsync --delete the unzipped files so files removed from the archive are also removed from the target.
	// Add the '-8' parameter to avoid mangling filenames with encodings that do not match the current locale.
	_processUtils.runSync(
	<String>['rsync', '-8', '-av', '--delete', unzippedFile.path, targetDirectory.path],
	throwOnError: true,
	verboseExceptions: true,
	);
	}
	} finally {
	tempDirectory.deleteSync(recursive: true);
	}
	} else {
	// Fall back to just unzipping.
	_logger.printTrace('Unable to find rsync, falling back to direct unzipping.');
	_processUtils.runSync(
	<String>['unzip', '-o', '-q', file.path, '-d', targetDirectory.path],
	throwOnError: true,
	verboseExceptions: true,
	);
	}
	}
	}

	class _WindowsUtils extends OperatingSystemUtils {
	_WindowsUtils({
	required super.fileSystem,
	required super.logger,
	required super.platform,
	required super.processManager,
	}) : super._private();

	@override
	HostPlatform hostPlatform = HostPlatform.windows_x64;

	@override
	void makeExecutable(File file) {}

	@override
	void chmod(FileSystemEntity entity, String mode) {}

	@override
	List<File> _which(String execName, { bool all = false }) {
	if (!_processManager.canRun('where')) {
	// `where` could be missing if system32 is not on the PATH.
	throwToolExit(
	'Cannot find the executable for `where`. This can happen if the System32 '
	r'folder (e.g. C:\Windows\System32 ) is removed from the PATH environment '
	'variable. Ensure that this is present and then try again after restarting '
	'the terminal and/or IDE.'
	);
	}
	// `where` always returns all matches, not just the first one.
	final ProcessResult result = _processManager.runSync(<String>['where', execName]);
	if (result.exitCode != 0) {
	return const <File>[];
	}
	final List<String> lines = (result.stdout as String).trim().split('\n');
	if (all) {
	return lines.map<File>((String path) => _fileSystem.file(path.trim())).toList();
	}
	return <File>[_fileSystem.file(lines.first.trim())];
	}

	@override
	void unzip(File file, Directory targetDirectory) {
	final Archive archive = ZipDecoder().decodeBytes(file.readAsBytesSync());
	_unpackArchive(archive, targetDirectory);
	}

	@override
	void unpack(File gzippedTarFile, Directory targetDirectory) {
	final Archive archive = TarDecoder().decodeBytes(
	GZipDecoder().decodeBytes(gzippedTarFile.readAsBytesSync()),
	);
	_unpackArchive(archive, targetDirectory);
	}

	void _unpackArchive(Archive archive, Directory targetDirectory) {
	for (final ArchiveFile archiveFile in archive.files) {
	// The archive package doesn't correctly set isFile.
	if (!archiveFile.isFile \|\| archiveFile.name.endsWith('/')) {
	continue;
	}

	final File destFile = _fileSystem.file(
	_fileSystem.path.canonicalize(
	_fileSystem.path.join(
	targetDirectory.path,
	archiveFile.name,
	),
	),
	);

	// Validate that the destFile is within the targetDirectory we want to
	// extract to.
	//
	// See https://snyk.io/research/zip-slip-vulnerability for more context.
	final String destinationFileCanonicalPath = _fileSystem.path.canonicalize(
	destFile.path,
	);
	final String targetDirectoryCanonicalPath = _fileSystem.path.canonicalize(
	targetDirectory.path,
	);
	if (!destinationFileCanonicalPath.startsWith(targetDirectoryCanonicalPath)) {
	throw StateError(
	'Tried to extract the file $destinationFileCanonicalPath outside of the '
	'target directory $targetDirectoryCanonicalPath',
	);
	}

	if (!destFile.parent.existsSync()) {
	destFile.parent.createSync(recursive: true);
	}
	destFile.writeAsBytesSync(archiveFile.content as List<int>);
	}
	}

	@override
	File makePipe(String path) {
	throw UnsupportedError('makePipe is not implemented on Windows.');
	}

	String? _name;

	@override
	String get name {
	if (_name == null) {
	final ProcessResult result = _processManager.runSync(
	<String>['ver'], runInShell: true);
	if (result.exitCode == 0) {
	_name = (result.stdout as String).trim();
	} else {
	_name = super.name;
	}
	}
	return _name!;
	}

	@override
	String get pathVarSeparator => ';';
	}

	/// Find and return the project root directory relative to the specified
	/// directory or the current working directory if none specified.
	/// Return null if the project root could not be found
	/// or if the project root is the flutter repository root.
	String? findProjectRoot(FileSystem fileSystem, [ String? directory ]) {
	const String kProjectRootSentinel = 'pubspec.yaml';
	directory ??= fileSystem.currentDirectory.path;
	Directory currentDirectory = fileSystem.directory(directory).absolute;
	while (true) {
	if (currentDirectory.childFile(kProjectRootSentinel).existsSync()) {
	return currentDirectory.path;
	}
	if (!currentDirectory.existsSync() \|\| currentDirectory.parent.path == currentDirectory.path) {
	return null;
	}
	currentDirectory = currentDirectory.parent;
	}
	}

	enum HostPlatform {
	darwin_x64,
	darwin_arm64,
	linux_x64,
	linux_arm64,
	windows_x64,
	}

	String getNameForHostPlatform(HostPlatform platform) {
	switch (platform) {
	case HostPlatform.darwin_x64:
	return 'darwin-x64';
	case HostPlatform.darwin_arm64:
	return 'darwin-arm64';
	case HostPlatform.linux_x64:
	return 'linux-x64';
	case HostPlatform.linux_arm64:
	return 'linux-arm64';
	case HostPlatform.windows_x64:
	return 'windows-x64';
	}
	}