[Q] su -c not working in root app - Android Q&A, Help & Troubleshooting

I am currently trying to write a root app.
I know that I can execute shell commands in a root shell like this.
However, I also want to execute some commands that way:
Code:
su -c[command]
But I can't get it to work if I use commands with parameters like ls -l or mkdir <path>. Executing something like su -c reboot works fine.
According to this it should work.
If I execute these commands using an adb shell or the Terminal Emulator app, they work fine.
This is my code:
Code:
package de.nikwen.sutest;
import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Runtime runtime = Runtime.getRuntime();
try {
runtime.exec("su");
runtime.exec("su -c 'mkdir /data/data/abcdef'");
runtime.exec("su -c \"print asdf\"");
//However, this works:
// runtime.exec("su -c 'reboot'");
} catch (IOException e) {
e.printStackTrace();
}
}
}
I get this logcat:
Code:
04-02 21:03:14.509: D/su(3620): su invoked.
04-02 21:03:14.519: E/su(3624): Unknown id: /data/data/abcdef'
04-02 21:03:14.519: E/su(3624):
04-02 21:03:14.529: D/su(3623): su invoked.
04-02 21:03:14.539: D/su(3625): su invoked.
04-02 21:03:14.559: E/su(3626): Unknown id: asdf"
04-02 21:03:14.559: E/su(3626):
04-02 21:03:14.639: D/su(3629): 10079 de.nikwen.sutest executing 0 /system/bin/sh using shell /system/bin/sh : sh
Does anybody have an idea to solve my problems?
Could anybody please test this code on his device? I would really appreciate this as it could be ROM related. (http://forum.xda-developers.com/showthread.php?t=2180669)

---

Well, as far I know if you already used su you don't need to use it in the other commands, like this:
Code:
runtime.exec("su");
runtime.exec("mkdir /data/data/abcdef");
Anyway, to run commands as root easily, I recommend you RootTools

---

RoberGalarga said:
Well, as far I know if you already used su you don't need to use it in the other commands, like this:
Code:
runtime.exec("su");
runtime.exec("mkdir /data/data/abcdef");
Anyway, to run commands as root easily, I recommend you RootTools
Click to expand...
Click to collapse
First of all: Big thanks for your answer. :good:
Well, it doesn't work if I do not use
Code:
runtime.exec("su");
And not using the su command again works, but only if you write the commands into the OutputStream of the process which is returned.
You have to call it at least once after installation to make the SU app ask the user for permission. Then the other lines should work on its own.
The advantage of using su -c [command] is that the user isn't shown all these annoying Toasts like "App x has been granted Su permissions", just the first time when it requests su rights after each launch of the app. My app has to call these functions very often and all these Toasts are VERY annoying. If you look at apps like file managers, there is also just one Toast at launch time and then they execute all commands without any Toast.
According to this you should execute everything like this:
Usage: su -c 'command'
su -c 'command1; command2; .... ; commandN'
Click to expand...
Click to collapse
My question is just if this works on other devices or ROMs. I will really appreciate if you try it.
And if it doesn't, then my question will be why it doesn't.
EDIT: And I don't want to use any libraries, even though it would be much easier.

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The strange thing is that the last quotation mark is seen as a part of the argument.
EDIT: Inserting a space before the quotation mark doesn't work:
Code:
04-03 00:02:59.129: E/su(13793): Unknown id: /data/data/abcdef
04-03 00:02:59.129: E/su(13793):
04-03 00:02:59.139: D/su(13790): su invoked.
04-03 00:02:59.139: D/su(13792): su invoked.
04-03 00:02:59.159: D/su(13794): su invoked.
04-03 00:02:59.169: E/su(13795): Unknown id: asdf
04-03 00:02:59.169: E/su(13795):
04-03 00:02:59.189: D/su(13796): db allowed
04-03 00:02:59.219: D/su(13798): 10079 de.nikwen.sutest executing 0 /system/bin/sh using shell /system/bin/sh : sh
EDIT2: Deleting the last quotation mark also didn't help:
Code:
04-03 00:05:18.409: D/su(14117): su invoked.
04-03 00:05:18.439: D/su(14120): 10079 de.nikwen.sutest executing 0 /system/bin/sh using shell /system/bin/sh : sh
04-03 00:05:18.439: D/su(14118): db allowed
04-03 00:05:18.459: E/su(14123): Unknown id: /data/data/abcdef
04-03 00:05:18.459: E/su(14123):
04-03 00:05:18.469: D/su(14122): su invoked.
04-03 00:05:18.489: D/su(14124): su invoked.
04-03 00:05:18.489: E/su(14125): Unknown id: asdf
04-03 00:05:18.489: E/su(14125):

---

Ok, in Terminal Emulator this works fine (2.3.7, CM-bassed):
su -c "ls /sys"
So it's kinda weird =/

---

RoberGalarga said:
Ok, in Terminal Emulator this works fine (2.3.7, CM-bassed):
su -c "ls /sys"
So it's kinda weird =/
Click to expand...
Click to collapse
Yes, it is.
Did you try the source code?
If you want, I can compile it for you.

---

Flashed this and it doesn't work, too.

---

Here is the compiled apk.
Could somebody please test this?

---

Tested, don't seems to work (it should create the folder /data/data/abcdef right?)

---

RoberGalarga said:
Tested, don't seems to work (it should create the folder /data/data/abcdef right?)
Click to expand...
Click to collapse
Yes, it should.
Thank you very much for your answer as you have been the only one giving me answers. :good:
EDIT: The link in your signature is broken.

---

However, I don't understand why this works here:
Code:
Runtime.getRuntime().exec("/system/bin/su -c 'setprop ctl.stop zygote'");
Something else I found:
Usage:
su --> becomes root (starts /bin/sh as root)
su -c '' --> run a command or many commands separated by ; as root.
Click to expand...
Click to collapse
(http://de.appszoom.com/android_applications/tools/superuser-su_feoig.html)

---

I have solved the problem now:
Code:
package de.nikwen.sutest;
import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Runtime runtime = Runtime.getRuntime();
try {
runtime.exec("su");
runtime.exec(new String[] {"su", "-c", "mkdir /data/data/abcdef"});
runtime.exec(new String[] {"su", "-c", "print asdf"});
//do this to execute two ore more commands at once
runtime.exec(new String[] {"su", "-c", "mkdir /data/data/aaab; mkdir /data/data/aaac"});
} catch (IOException e) {
e.printStackTrace();
}
}
}
I know that I shouldn't run this on the main thread but in a service or at least in a different thread. This is for testing purposes only.
I missunderstood this blog entry.
But now everything works fine.
However, I still don't know why my first code example doesn't work. If anybody has an idea, please still answer my question as it hasn't been answered completely yet.
Again: Big thanks to RoberGalarga! :good: