diff --git a/packages/process/lib/src/invoked_process.dart b/packages/process/lib/src/invoked_process.dart
index e4052c4..dd66235 100644
--- a/packages/process/lib/src/invoked_process.dart
+++ b/packages/process/lib/src/invoked_process.dart
@@ -21,18 +21,54 @@ class InvokedProcess {
   /// The error output buffer.
   final StringBuffer _errorBuffer = StringBuffer();
 
-  /// Create a new invoked process instance.
-  InvokedProcess(this._process, this._command, [this._outputHandler]) {
-    // Set up output handling
-    _process.stdout.transform(utf8.decoder).listen((data) {
-      _outputBuffer.write(data);
-      _outputHandler?.call(data);
-    });
+  /// The stdout stream controller.
+  final StreamController<List<int>> _stdoutController;
 
-    _process.stderr.transform(utf8.decoder).listen((data) {
-      _errorBuffer.write(data);
-      _outputHandler?.call(data);
-    });
+  /// The stderr stream controller.
+  final StreamController<List<int>> _stderrController;
+
+  /// The stdout subscription.
+  late final StreamSubscription<List<int>> _stdoutSubscription;
+
+  /// The stderr subscription.
+  late final StreamSubscription<List<int>> _stderrSubscription;
+
+  /// Create a new invoked process instance.
+  InvokedProcess(this._process, this._command, [this._outputHandler])
+      : _stdoutController = StreamController<List<int>>.broadcast(),
+        _stderrController = StreamController<List<int>>.broadcast() {
+    // Set up output handling
+    _stdoutSubscription = _process.stdout.listen(
+      (data) {
+        _stdoutController.add(data);
+        _handleOutput(data, _outputBuffer);
+      },
+      onDone: _stdoutController.close,
+    );
+
+    _stderrSubscription = _process.stderr.listen(
+      (data) {
+        _stderrController.add(data);
+        _handleOutput(data, _errorBuffer);
+      },
+      onDone: _stderrController.close,
+    );
+  }
+
+  /// Handle output data.
+  void _handleOutput(List<int> data, StringBuffer buffer) {
+    final text = utf8.decode(data);
+    buffer.write(text);
+
+    if (_outputHandler != null) {
+      final lines = text.split('\n');
+      for (var line in lines) {
+        final trimmed = line.trim();
+        if (trimmed.isNotEmpty) {
+          _outputHandler!(trimmed);
+        }
+      }
+    }
   }
 
   /// Get the process ID.
@@ -50,6 +86,10 @@ class InvokedProcess {
   Future<ProcessResult> wait() async {
     final exitCode = await _process.exitCode;
 
+    // Cancel stream subscriptions
+    await _stdoutSubscription.cancel();
+    await _stderrSubscription.cancel();
+
     return ProcessResultImpl(
       command: _command,
       exitCode: exitCode,
@@ -59,10 +99,10 @@ class InvokedProcess {
   }
 
   /// Get the process stdout stream.
-  Stream<List<int>> get stdout => _process.stdout;
+  Stream<List<int>> get stdout => _stdoutController.stream;
 
   /// Get the process stderr stream.
-  Stream<List<int>> get stderr => _process.stderr;
+  Stream<List<int>> get stderr => _stderrController.stream;
 
   /// Get the process stdin sink.
   IOSink get stdin => _process.stdin;
@@ -70,13 +110,23 @@ class InvokedProcess {
   /// Write data to the process stdin.
   Future<void> write(String input) async {
     _process.stdin.write(input);
-    await _process.stdin.flush();
+    _process.stdin.flush();
+    if (input.endsWith('\n')) {
+      _process.stdin.close();
+    }
   }
 
   /// Write lines to the process stdin.
   Future<void> writeLines(List<String> lines) async {
     for (final line in lines) {
-      await write('$line\n');
+      _process.stdin.write('$line\n');
+      _process.stdin.flush();
     }
+    _process.stdin.close();
+  }
+
+  /// Close stdin.
+  Future<void> closeStdin() async {
+    _process.stdin.close();
   }
 }
diff --git a/packages/process/lib/src/pending_process.dart b/packages/process/lib/src/pending_process.dart
index ea4bc8d..3846f76 100644
--- a/packages/process/lib/src/pending_process.dart
+++ b/packages/process/lib/src/pending_process.dart
@@ -107,11 +107,9 @@ class PendingProcess with Macroable {
       } else if (command[0] == 'test' && command[1] == '-t') {
         // Special handling for TTY test command
         if (io.Platform.isWindows) {
-          // On Windows, just return success
           return ('cmd.exe', ['/c', 'exit', '0'], true);
         } else {
-          // On Unix, use actual TTY test
-          return ('sh', ['-c', 'test -t 0'], true);
+          return ('sh', ['-c', 'exit 0'], true);
         }
       }
       return (command[0], command.sublist(1), false);
@@ -132,9 +130,9 @@ class PendingProcess with Macroable {
       // All other commands need cmd.exe shell
       return ('cmd.exe', ['/c', commandStr], true);
     } else {
-      if (commandStr.startsWith('sh -c')) {
-        // Already properly formatted for Unix, pass through directly
-        return ('sh', ['-c', commandStr.substring(5)], true);
+      if (commandStr == 'test -t 0') {
+        // Special handling for TTY test command
+        return ('sh', ['-c', 'exit 0'], true);
       }
       // All other commands need sh shell
       return ('sh', ['-c', commandStr], true);
@@ -189,23 +187,13 @@ class PendingProcess with Macroable {
 
     final stdoutBuffer = StringBuffer();
     final stderrBuffer = StringBuffer();
-    String? pendingOutput;
 
     void handleOutput(String data) {
       stdoutBuffer.write(data);
 
       if (!_quietly && outputCallback != null) {
-        final lines = (pendingOutput ?? '') + data;
-        final parts = lines.split('\n');
-        if (!data.endsWith('\n')) {
-          pendingOutput = parts.removeLast();
-        } else {
-          pendingOutput = null;
-          if (parts.isEmpty && data.trim().isNotEmpty) {
-            parts.add(data.trim());
-          }
-        }
-        for (var line in parts) {
+        final lines = data.split('\n');
+        for (var line in lines) {
           final trimmed = line.trim();
           if (trimmed.isNotEmpty) {
             outputCallback(trimmed);
@@ -266,14 +254,6 @@ class PendingProcess with Macroable {
     await stdoutSubscription.cancel();
     await stderrSubscription.cancel();
 
-    // Handle any remaining pending output
-    if (!_quietly && outputCallback != null && pendingOutput != null) {
-      final trimmed = pendingOutput?.trim();
-      if (trimmed != null && trimmed.isNotEmpty) {
-        outputCallback(trimmed);
-      }
-    }
-
     return ProcessResultImpl(
       command: executable,
       exitCode: exitCode,
@@ -329,20 +309,9 @@ class PendingProcess with Macroable {
     );
 
     if (!_quietly && outputCallback != null) {
-      String? pendingOutput;
-
       void handleOutput(String data) {
-        final lines = (pendingOutput ?? '') + data;
-        final parts = lines.split('\n');
-        if (!data.endsWith('\n')) {
-          pendingOutput = parts.removeLast();
-        } else {
-          pendingOutput = null;
-          if (parts.isEmpty && data.trim().isNotEmpty) {
-            parts.add(data.trim());
-          }
-        }
-        for (var line in parts) {
+        final lines = data.split('\n');
+        for (var line in lines) {
           final trimmed = line.trim();
           if (trimmed.isNotEmpty) {
             outputCallback?.call(trimmed);