remove shell dependancies

lib/cleanup_sshnp.dart

@@ -2,11 +2,10 @@
 import 'dart:io';
 // local packages
 import 'package:sshnoports/home_directory.dart';
+// @platform packages
+import 'package:at_utils/at_logger.dart';
 
-
-
-
-Future<void> cleanUp(sessionId,_logger) async {
+Future<void> cleanUp(String sessionId, AtSignLogger _logger) async {
   String? homeDirectory = getHomeDirectory();
   if (homeDirectory == null) {
     return;
@@ -16,9 +15,41 @@ Future<void> cleanUp(sessionId,_logger) async {
     sshHomeDirectory = homeDirectory + '\\.ssh\\';
   }
 // Wait a few seconds for the remote ssh session to connect back here
-// do we need to wait ?
- _logger.info('Tidying up files');
+// do we need to wait ? Yes as it takes time for the reverse ssh to connect
+// 2 seconds seems like a reasonable time...
+// could make it an option if folks have trouble.
+  _logger.info('Tidying up files');
+
   sleep(Duration(seconds: 2));
-  await Process.run('rm', ['${sessionId}_rsa', '${sessionId}_rsa.pub'], workingDirectory: sshHomeDirectory);
-  await Process.run('sed', ['-i', '/$sessionId/d', 'authorized_keys'], workingDirectory: sshHomeDirectory);
-}
+// Delete the generated RSA keys and remove the entry from ~/.ssh/authorized_keys
+  // await deleteFile('$sshHomeDirectory${sessionId}_rsa', _logger);
+  // await deleteFile('$sshHomeDirectory${sessionId}_rsa.pub', _logger);
+  //await removeSession(sshHomeDirectory, sessionId, _logger);
+
+}
+
+Future<int> deleteFile(String fileName, AtSignLogger _logger) async {
+  try {
+    final file = File(fileName);
+
+    await file.delete();
+  } catch (e) {
+    _logger.severe("Error deleting file : $fileName");
+  }
+  return 0;
+}
+
+Future<void> removeSession(String sshHomeDirectory, String sessionId, AtSignLogger _logger) async {
+  try {
+    final File file = File('${sshHomeDirectory}authorized_keys');
+    // read into List of strings
+    final List<String> lines = await file.readAsLines();
+    // find the line we want to remove
+    lines.removeWhere((element) => element.contains(sessionId));
+    // Write back the file and add a \n
+    await file.writeAsString(lines.join('\n'));
+    await file.writeAsString('\n', mode: FileMode.writeOnlyAppend);
+  } catch (e) {
+    _logger.severe('Unable to tidy up ${sshHomeDirectory}authorized_keys');
+  }
+}