"su" on Android neither giving error nor taking effects. How to run su commands successfully on rooted devices?

Question

I had rooted my device which is SAMSUNG GALAXY Note 4.

After that, I had installed a shell app from the app store and typed "su" and a Toast appeared stating that the shell guaranteed root access.

I had typed "setprop service.adb.tcp.port 5555" which gives command failed. So I typed "su - c 'setprop service.adb.tcp.port 5555' " which does not give error but also does not have effect since I still unable to connect wirelessly.

I had tried to run a non defined command like "su hdhdhd" which did not give an error!!!

But when opening adb shell from my PC when phone is connected by USB, I can successfully run su commands!!!

Why su commands can be executed from PC adb shell while on a phone shell it does not succeed????!!!!!!

I want to connect my phone with the pc through adb without using USB at all even at the first time...

Thanks in advance...

Answer 1

I had solved the problem by writing my own android app that runs a shell script containing the commands I want.

The problem was that not all terminal emulators available on the play store function correctly especially with root privileges.

       try {
        String line;

        Process process = Runtime.getRuntime().exec("su");
        OutputStream stdin = process.getOutputStream();
        InputStream stderr = process.getErrorStream();
        InputStream stdout = process.getInputStream();

        stdin.write(("setprop service.adb.tcp.port 5555\n").getBytes());
        stdin.write(("stop adbd\n").getBytes());
        stdin.write(("start adbd\n").getBytes());
        stdin.write("exit\n".getBytes());
        stdin.flush();

        stdin.close();
        BufferedReader br = new BufferedReader(new InputStreamReader(stdout));
        while ((line = br.readLine()) != null) {
            Log.d("[Output]", line);
        }
        br.close();
        br =
                new BufferedReader(new InputStreamReader(stderr));
        while ((line = br.readLine()) != null) {
            Log.e("Error", line);
        }
        br.close();

        process.waitFor();
        process.destroy();

    } catch (Exception exception) {}

I want this shell script to run automatically on system startup. There are several apps on the play store for this purpose, but they are malfunctioning! So, I had updated my app to run automatically on system startup by implementing a BroadcastReceiver.

package com.example.liveandroid;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class ADBD extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) {
            Intent i = new Intent(context, MainActivity.class);
            i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(i);
        }
    }
}

AndroidManifest Configuration:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.example.liveandroid">
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        tools:ignore="GoogleAppIndexingWarning">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".ADBD">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <action android:name="android.intent.action.QUICKBOOT_POWERON" />
            </intent-filter>
        </receiver>
    </application>

</manifest>