Root shell with no outputs

app/src/main/java/com/topjohnwu/magisk/MagiskFragment.java

@@ -197,7 +197,7 @@ public class MagiskFragment extends Fragment
                             @Override
                             public void onFinish() {
                                 progress.setMessage(getString(R.string.reboot_countdown, 0));
-                                magiskManager.rootShell.su(
+                                magiskManager.rootShell.su_raw(
                                         "mv -f " + uninstaller + " /cache/" + MagiskManager.UNINSTALLER,
                                         "mv -f " + utils + " /data/magisk/" + MagiskManager.UTIL_FUNCTIONS,
                                         "reboot"

app/src/main/java/com/topjohnwu/magisk/MagiskLogFragment.java

@@ -154,7 +154,7 @@ public class MagiskLogFragment extends Fragment {
                     return "";
 
                 case 1:
-                    magiskManager.rootShell.su("echo > " + MAGISK_LOG);
+                    magiskManager.rootShell.su_raw("echo > " + MAGISK_LOG);
                     SnackbarMaker.make(txtLog, R.string.logs_cleared, Snackbar.LENGTH_SHORT).show();
                     return "";
 

app/src/main/java/com/topjohnwu/magisk/MagiskManager.java

@@ -125,7 +125,7 @@ public class MagiskManager extends Application {
         File busybox = new File(getApplicationInfo().dataDir + "/busybox/busybox");
         if (!busybox.exists() || !TextUtils.equals(prefs.getString("busybox_version", ""), BUSYBOX_VERSION)) {
             busybox.getParentFile().mkdirs();
-            rootShell.su(
+            rootShell.su_raw(
                     "cp -f " + new File(getApplicationInfo().nativeLibraryDir, "libbusybox.so") + " " + busybox,
                     "chmod -R 755 " + busybox.getParent(),
                     busybox + " --install -s " + busybox.getParent()
@@ -148,7 +148,7 @@ public class MagiskManager extends Application {
                 .putString("busybox_version", BUSYBOX_VERSION)
                 .apply();
         // Add busybox to PATH
-        rootShell.su("PATH=$PATH:" + busybox.getParent());
+        rootShell.su_raw("PATH=$PATH:" + busybox.getParent());
 
         // Create notification channel on Android O
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

app/src/main/java/com/topjohnwu/magisk/SettingsActivity.java

@@ -175,11 +175,11 @@ public class SettingsActivity extends Activity {
                 case "hosts":
                     enabled = prefs.getBoolean("hosts", false);
                     if (enabled) {
-                        magiskManager.rootShell.su(
+                        magiskManager.rootShell.su_raw(
                                 "cp -af /system/etc/hosts /magisk/.core/hosts",
                                 "mount -o bind /magisk/.core/hosts /system/etc/hosts");
                     } else {
-                        magiskManager.rootShell.su(
+                        magiskManager.rootShell.su_raw(
                                 "umount -l /system/etc/hosts",
                                 "rm -f /magisk/.core/hosts");
                     }

app/src/main/java/com/topjohnwu/magisk/asyncs/FlashZip.java

@@ -75,7 +75,7 @@ public class FlashZip extends ParallelTask<Void, String, Integer> {
     }
 
     private int cleanup(int ret) {
-        magiskManager.rootShell.su(
+        magiskManager.rootShell.su_raw(
                 "rm -rf " + mCachedFile.getParent() + "/*",
                 "rm -rf " + MagiskManager.TMP_FOLDER_PATH
         );
@@ -146,7 +146,7 @@ public class FlashZip extends ParallelTask<Void, String, Integer> {
         new AlertDialogBuilder(activity)
                 .setTitle(R.string.reboot_title)
                 .setMessage(R.string.reboot_msg)
-                .setPositiveButton(R.string.reboot, (dialogInterface, i) -> magiskManager.rootShell.su("reboot"))
+                .setPositiveButton(R.string.reboot, (dialogInterface, i) -> magiskManager.rootShell.su_raw("reboot"))
                 .setNegativeButton(R.string.no_thanks, null)
                 .show();
     }

app/src/main/java/com/topjohnwu/magisk/asyncs/ProcessMagiskZip.java

@@ -33,7 +33,7 @@ public class ProcessMagiskZip extends ParallelTask<Void, Void, Boolean> {
     @Override
     protected Boolean doInBackground(Void... params) {
         if (Shell.rootAccess()) {
-            magiskManager.rootShell.su("rm -f /dev/.magisk",
+            magiskManager.rootShell.su_raw("rm -f /dev/.magisk",
                     (mBoot != null) ? "echo \"BOOTIMAGE=" + mBoot + "\" >> /dev/.magisk" : "",
                     "echo \"KEEPFORCEENCRYPT=" + String.valueOf(mEnc) + "\" >> /dev/.magisk",
                     "echo \"KEEPVERITY=" + String.valueOf(mVerity) + "\" >> /dev/.magisk"

app/src/main/java/com/topjohnwu/magisk/utils/Shell.java

@@ -18,12 +18,12 @@ public class Shell {
     // -1 = problematic/unknown issue; 0 = not rooted; 1 = properly rooted
     public static int rootStatus;
 
-    private static boolean isInit = false;
-
     private final Process rootShell;
     private final DataOutputStream rootSTDIN;
     private final DataInputStream rootSTDOUT;
 
+    private boolean isValid;
+
     private Shell() {
         Process process;
         try {
@@ -34,15 +34,17 @@ public class Shell {
             rootShell = null;
             rootSTDIN = null;
             rootSTDOUT = null;
+            isValid = false;
             return;
         }
 
         rootStatus = 1;
+        isValid = true;
         rootShell = process;
         rootSTDIN = new DataOutputStream(rootShell.getOutputStream());
         rootSTDOUT = new DataInputStream(rootShell.getInputStream());
 
-        su("umask 022");
+        su_raw("umask 022");
         List<String> ret = su("echo -BOC-", "id");
 
         if (ret.isEmpty()) {
@@ -118,33 +120,43 @@ public class Shell {
     }
 
     public List<String> su(String... commands) {
+        if (!isValid) return null;
         List<String> res = new ArrayList<>();
         su(res, commands);
         return res;
     }
 
-    public void su(List<String> res, String... commands) {
+    public void su_raw(String... commands) {
-        try {
+        if (!isValid) return;
-            rootShell.exitValue();
-            return;  // The process is dead, return
-        } catch (IllegalThreadStateException ignored) {
-            // This should be the expected result
-        }
         synchronized (rootShell) {
-            StreamGobbler STDOUT = new StreamGobbler(rootSTDOUT, Collections.synchronizedList(res), true);
-            STDOUT.start();
             try {
                 for (String command : commands) {
                     rootSTDIN.write((command + "\n").getBytes("UTF-8"));
                     rootSTDIN.flush();
                 }
-                rootSTDIN.write(("echo \'-root-done-\'\n").getBytes("UTF-8"));
+            } catch (IOException e) {
-                rootSTDIN.flush();
-                STDOUT.join();
-            } catch (InterruptedException | IOException e) {
                 e.printStackTrace();
                 rootShell.destroy();
+                isValid = false;
             }
         }
     }
+
+    public void su(List<String> output, String... commands) {
+        if (!isValid) return;
+        try {
+            rootShell.exitValue();
+            isValid = false;
+            return;  // The process is dead, return
+        } catch (IllegalThreadStateException ignored) {
+            // This should be the expected result
+        }
+        synchronized (rootShell) {
+            StreamGobbler STDOUT = new StreamGobbler(rootSTDOUT, output, true);
+            STDOUT.start();
+            su_raw(commands);
+            su_raw("echo \'-root-done-\'");
+            try { STDOUT.join(); } catch (InterruptedException ignored) {}
+        }
+    }
 }

app/src/main/java/com/topjohnwu/magisk/utils/StreamGobbler.java

@@ -29,13 +29,17 @@ public class StreamGobbler extends Thread {
      * @param outputList  {@literal List<String>} to write to, or null
      */
     public StreamGobbler(InputStream inputStream, List<String> outputList) {
+        try {
+            while (inputStream.available() != 0) {
+                inputStream.skip(inputStream.available());
+            }
+        } catch (IOException ignored) {}
         reader = new BufferedReader(new InputStreamReader(inputStream));
         writer = outputList;
     }
 
     public StreamGobbler(InputStream inputStream, List<String> outputList, boolean root) {
-        reader = new BufferedReader(new InputStreamReader(inputStream));
+        this(inputStream, outputList);
-        writer = outputList;
         isRoot = root;
     }
 
@@ -48,7 +52,7 @@ public class StreamGobbler extends Thread {
                 if (TextUtils.equals(line, "-root-done-"))
                     return;
                 writer.add(line);
-                Logger.shell(isRoot, "OUT: " + line);
+                Logger.shell(isRoot, line);
             }
         } catch (IOException e) {
             // reader probably closed, expected exit condition

app/src/main/java/com/topjohnwu/magisk/utils/Utils.java

@@ -52,12 +52,12 @@ public class Utils {
     public static void createFile(Shell shell, String path) {
         String folder = path.substring(0, path.lastIndexOf('/'));
         String command = "mkdir -p " + folder + " 2>/dev/null; touch " + path + " 2>/dev/null; if [ -f \"" + path + "\" ]; then echo true; else echo false; fi";
-        shell.su(command);
+        shell.su_raw(command);
     }
 
     public static void removeItem(Shell shell, String path) {
         String command = "rm -rf " + path + " 2>/dev/null; if [ -e " + path + " ]; then echo false; else echo true; fi";
-        shell.su(command);
+        shell.su_raw(command);
     }
 
     public static List<String> getModList(Shell shell, String path) {
@@ -66,14 +66,8 @@ public class Utils {
     }
 
     public static List<String> readFile(Shell shell, String path) {
-        List<String> ret;
         String command = "cat " + path;
-        if (Shell.rootAccess()) {
+        return shell.su(command);
-            ret = shell.su(command);
-        } else {
-            ret = Shell.sh(command);
-        }
-        return ret;
     }
 
     public static void dlAndReceive(Context context, DownloadReceiver receiver, String link, String filename) {