Android AsyncTask process (logcat) does not output messages (on emulator) - android

The logcat process is launched, I don't get any error or force close. It simply seems to not generate any output.
String commandLine = "logcat -v time -b main *:V";
String line;
try {
process = Runtime.getRuntime().exec(commandLine);
bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while(!mStop && (line = bufferedReader.readLine()) != null && newMessages.size() < maxMessages) {
// It does not reach this point
// Debugger shows
// mStop == false
// newMessages.size == 0
// maxMessages == 5000
// line == null
The suspicion is that logcat exits wihtout printing anything out. I tried this in a command line and it does output logcat messages.
I replaced logcat with ls and then bufferedReader does fill line.
The inspection of bufferedReader shows member in(InputStreamReader) which itself has a memeber endOfInput which is false before the readLine() and becomes true right after it.
LAST NEWS:
I opened the Terminal Emulator within the emulator itself, and run it:
$ logcat -v time -b main *:V
Unable to open log device '/dev/log/main': Permission denied
$

After looking for similar post it seems this is quite a duplicate from:
Android unable to run logcat from application
In short, the problem was: a user permission is required to read logs, so I added:
<uses-permission android:name="android.permission.READ_LOGS" />
to the manifest and it works fine now.

Related

how can I get adb permission on android 7.1?

my environment:
cpu:rk3288
os:android7.1
transfer method:sftp
I wrote android code to do these things below:
get the logcat with code "adb logcat -d -v time -f /mnt/sdcard/logcat.txt"
pull the file logcat.tx to the server with sftp
in 1st step I coding some java language with android studio like below, if anyone can help me, thanks!
Process p = Runtime.getRuntime().exec("adb logcat -d -v time -f /mnt/sdcard/logcat.txt");
error massage:
java.io.IOException: Cannot run program "adb": error=13, Permission denied
You can't use adb commands from inside the device, even if you somehow have it in the device you would need root permissions. The adb is the bridge between the PC and the device. Take a look here: https://developer.android.com/studio/command-line/adb
Although you probably can just remove the adb and use logcat directly, like:
Process p = Runtime.getRuntime().exec("logcat -d -v time -f /mnt/sdcard/logcat.txt");
Here you can see some more options about using the logcat command: Read logcat programmatically within application, including Reetpreet Brar's answer, that I think will be better for you:
Process pq=Runtime.getRuntime().exec("logcat v main"); //adapt the command for yourself
BufferedReader brq = new BufferedReader(new InputStreamReader(pq.getInputStream()));
String sq="";
while ((sq = brq.readLine()) != null)
{
//here you can do what you want with the log, like writing in a file to
//send to the server later.
}
Here you can choose methods to write your file: How to Read/Write String from a File in Android
Then, just send the file to the server.

Trigger UIAutomator Test Script programmatically

We are using UIAutomator for automation.
To run UIAutomator test scripts we used to compile the scripts from command prompt by using either USB or Wifi adb and it will run on the android device.
UiAutomator scripts will come in jar format after compilation.
We will push the jar in the device and we have trigger the test scripts.
The command to start the test script in “adb shell uiautomator runtest TestPackage.jar”.
It is working with normal adb connection.
But in our case we have to initiate the test scripts without any adb connection.
So we tried by passing the commands programmatically in the device using this java code
try {
StringBuffer output = new StringBuffer();
Process p = Runtime.getRuntime().exec(params[0]);
BufferedReader reader = new BufferedReader(new InputStreamReader(
p.getInputStream()));
String line = "";
while ((line = reader.readLine()) != null) {
output.append(line + "\n");
p.waitFor();
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
After the execution we are getting the following exception:
java.lang.securityException : longMsg = You do not have android.permission.RETRIEVE_WINDOW_CONTENT required to call registerUITestAutomationService
If we run scripts from command prompt with adb connection it is working. But if we tried the command programmatically we are getting this exception.
We came to know that the above mentioned issue can be overcome in a rooted android device by enabling the RETRIEVE_WINDOW_CONTENT permission. But we want this scripts to run on a non-rooted setup.
Can anyone help me in explaining this security permission issue?
How can I resolve it?

Android logcat command

I want to get "last 25 logs of tag name CordovaLog"
I tried
logcat -t 25 CordovaLog
I do get 25 logs but of all the tag names. Also what if there are no 25 Cordova Log ? Will it return whatever is available.
So what is the right command ?
Thanks.
EDIT 1-
Process process = Runtime.getRuntime().exec("logcat -d -t 25 CordovaLog:V *:S");
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(process.getInputStream()));
StringBuilder log = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null)
{
log.append(line+"<br />");
}
return log.toString();
So Is this code getting all the logs are filting to get "Cordova logs" ? OR it's just getting "Cordova logs" ?
It's crashing as I have lots of logs.
the correct use will be
logcat -d -t 25 CordovaLog:V *:S
With this, you will print all that have the tag CordovaLog, and will silent everything else.
You can have more information in the official documentation.
Edite to fix the correct answer (see comment below). It will print the last 25 entries, or less in case there are less than 25 entries.

Is it possible to execute adb commands through my android app?

Can anyone say, whether adb commands can be executed through my android application. If it is possible to execute, how it can be implemented?
You can do it with this:
Process process = Runtime.getRuntime().exec("your command");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
Don't forget to surround it with a try and catch statement.
Edit:
#Phix is right, ProcessBuilder would be better to use.
Normal Android apps have different privileges to processes started via adb, e.g., processes started via adb are allowed to the capture the screen whereas normal apps aren't. So, you can execute commands from your app via Runtime.getRuntime().exec(), but they won't have the same privileges as if you had executed from an adb shell.
i came across this post looking for a different query, but i have worked specifically with input on android before, so I'd just like to put some clarity on the matter.
The reason why
Runtime.getRuntime().exec("adb shell input keyevent 120");
Is not working, is because you are not removing
adb shell
The ADB part is only for use on your computer, if you have incorrectly installed ADB, the command would actually be a path to the adb.exe file on your computer, like this
C:\XXXX\ADB Files\adb.exe shell
or
C:\XXXX\ADB Files\adb shell
The shell part tells the ADB program on your computer to access the devices shell, so your device will not know what shell is either...
Using sh /path/to/commandList.sh will execute the commads listed in commandList.sh as it is a shell script (a .batch file on windows is similar )
The command you want to use is
Runtime.getRuntime().exec("input keyevent 120");
However this will cause Environment null and working directory null, you can bypass this by writing the commands to a shell script ( .sh file ) and then running the script with
Runtime.getRuntime().exec("sh path/to/shellScript.sh");
Sometimes the sh is not needed, but i use it just incase.
I hope this clears at least something up :)
adb shell invoked in Runtime.getRuntime().exec is not running under shell user. It provide shell but with same process owner user (like u0_a44). That's the reason all command did not work.
This is what I do in Kotlin, I also get command responses too
fun runShellCommand(command: String) {
// Run the command
val process = Runtime.getRuntime().exec(command)
val bufferedReader = BufferedReader(
InputStreamReader(process.inputStream)
)
// Grab the results
val log = StringBuilder()
var line: String?
line = bufferedReader.readLine()
while (line != null) {
log.append(line + "\n")
line = bufferedReader.readLine()
}
val Reader = BufferedReader(
InputStreamReader(process.errorStream)
)
// if we had an error during ex we get here
val error_log = StringBuilder()
var error_line: String?
error_line = Reader.readLine()
while (error_line != null) {
error_log.append(error_line + "\n")
error_line = Reader.readLine()
}
if (error_log.toString() != "")
Log.info("ADB_COMMAND", "command : $command $log error $error_log")
else
Log.info("ADB_COMMAND", "command : $command $log")
}
Executing
Runtime.getRuntime().exec("adb shell input keyevent 120");
I got the following error:
java.io.IOException: Cannot run program "adb": error=13, Permission denied.
Executing
Runtime.getRuntime().exec("adb shell input keyevent 120");
There is no error but at the same time, my request is not processed to take the screenshot.
I found out this was working in earlier versions of android but later it was removed. Though I'm not able to provide the source here why it is not working.
Hope this helps someone like me who is trying to use this approach to take the screenshot when the app is not in the foreground.
Process process = Runtime.getRuntime().exec("su");
DataOutputStream os = new DataOutputStream(process.getOutputStream());
string cmd = "/system/bin/input keyevent 23\n";
os.writeBytes(cmd);
the phone must be rooted. here I have executed adb command "input keyevent 23".
remember when you execute adb command through su you does not need to add "adb shell input keyevent 23"

How do I get the logfile from an Android device?

I would like to pull the log file from a device to my PC. How can I do that?
Logcollector is a good option but you need to install it first.
When I want to get the logfile to send by mail, I usually do the following:
connect the device to the pc.
Check that I already setup my os for that particular device.
Open a terminal
Run adb shell logcat > log.txt
I hope this code will help someone. It took me 2 days to figure out how to log from device, and then filter it:
public File extractLogToFileAndWeb(){
//set a file
Date datum = new Date();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd", Locale.ITALY);
String fullName = df.format(datum)+"appLog.log";
File file = new File (Environment.getExternalStorageDirectory(), fullName);
//clears a file
if(file.exists()){
file.delete();
}
//write log to file
int pid = android.os.Process.myPid();
try {
String command = String.format("logcat -d -v threadtime *:*");
Process process = Runtime.getRuntime().exec(command);
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
StringBuilder result = new StringBuilder();
String currentLine = null;
while ((currentLine = reader.readLine()) != null) {
if (currentLine != null && currentLine.contains(String.valueOf(pid))) {
result.append(currentLine);
result.append("\n");
}
}
FileWriter out = new FileWriter(file);
out.write(result.toString());
out.close();
//Runtime.getRuntime().exec("logcat -d -v time -f "+file.getAbsolutePath());
} catch (IOException e) {
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
//clear the log
try {
Runtime.getRuntime().exec("logcat -c");
} catch (IOException e) {
Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_SHORT).show();
}
return file;
}
as pointed by #mehdok
add the permission to the manifest for reading logs
<uses-permission android:name="android.permission.READ_LOGS" />
I would use something of this sort :
$adb logcat -d > logcat.txt
The -d option dumps the entire circular buffer into the text file and if you are looking for a particular action/intent try
$adb logcat -d | grep 'com.whatever.you.are.looking.for' -B 100 -A 100 > shorterlog.txt
Hope this helps :)
For those not interested in USB debugging or using adb there is an easier solution. In Android 6 (Not sure about prior version) there is an option under developer tools: Take Bug Report
Clicking this option will prepare a bug report and prompt you to save it to drive or have it sent in email.
I found this to be the easiest way to get logs. I don't like to turn on USB debugging.
EDIT:
The internal log is a circular buffer in memory. There are actually a few such circular buffers for each of: radio, events, main. The default is main.
To obtain a copy of a buffer, one technique involves executing a command on the device and obtaining the output as a string variable.
SendLog is an open source App which does just this: http://www.l6n.org/android/sendlog.shtml
The key is to run logcat on the device in the embedded OS. It's not as hard as it sounds, just check out the open source app in the link.
Often I get the error "logcat read: Invalid argument". I had to clear the log, before reading from the log.
I do like this:
prompt> cd ~/Desktop
prompt> adb logcat -c
prompt> adb logcat | tee log.txt
I know it's an old question, but I believe still valid even in 2018.
There is an option to Take a bug report hidden in Developer options in every android device.
NOTE: This would dump whole system log
How to enable developer options? see: https://developer.android.com/studio/debug/dev-options
What works for me:
Restart your device (in order to create minimum garbage logs for developer to analyze)
Reproduce your bug
Go to Settings -> Developer options -> Take a bug report
Wait for Android system to collect the logs (watch the progressbar in notification)
Once it completes, tap the notification to share it (you can use gmail or whetever else)
how to read this?
open bugreport-1960-01-01-hh-mm-ss.txt
you probably want to look for something like this:
------ SYSTEM LOG (logcat -v threadtime -v printable -d *:v) ------
--------- beginning of crash
06-13 14:37:36.542 19294 19294 E AndroidRuntime: FATAL EXCEPTION: main
or:
------ SYSTEM LOG (logcat -v threadtime -v printable -d *:v) ------
--------- beginning of main
A simple way is to make your own log collector methods or even just an existing log collector app from the market.
For my apps I made a report functionality which sends the logs to my email (or even to another place - once you get the log you can do whether you want with it).
Here is a simple example about how to get the log file from a device:
http://code.google.com/p/android-log-collector/
Simple just run the following command to get the output to your terminal:
adb shell logcat
Two steps:
Generate the log
Load Gmail to send the log
.
Generate the log
File generateLog() {
File logFolder = new File(Environment.getExternalStorageDirectory(), "MyFolder");
if (!logFolder.exists()) {
logFolder.mkdir();
}
String filename = "myapp_log_" + new Date().getTime() + ".log";
File logFile = new File(logFolder, filename);
try {
String[] cmd = new String[] { "logcat", "-f", logFile.getAbsolutePath(), "-v", "time", "ActivityManager:W", "myapp:D" };
Runtime.getRuntime().exec(cmd);
Toaster.shortDebug("Log generated to: " + filename);
return logFile;
}
catch (IOException ioEx) {
ioEx.printStackTrace();
}
return null;
}
Load Gmail to send the log
File logFile = generateLog();
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(logFile));
intent.setType("multipart/");
startActivity(intent);
References for #1
https://stackoverflow.com/a/34883741/2162226
https://stackoverflow.com/a/3359857/2162226
~~
For #2 - there are many different answers out there for how to load the log file to view and send. Finally, the solution here actually worked to both:
load Gmail as an option
attaches the file successfully
Big thanks to https://stackoverflow.com/a/22367055/2162226 for the correctly working answer
Thanks to user1354692 I could made it more easy, with only one line! the one he has commented:
try {
File file = new File(Environment.getExternalStorageDirectory(), String.valueOf(System.currentTimeMillis()));
Runtime.getRuntime().exec("logcat -d -v time -f " + file.getAbsolutePath());}catch (IOException e){}
I have created a small library (.aar) to retrieve the logs by email. You can use it with Gmail accounts. It is pretty simple but works. You can get a copy from here
The site is in Spanish, but there is a PDF with an english version of the product description.
I hope it can help.
First make sure adb command is executable by setting PATH to android sdk platform-tools:
export PATH=/Users/espireinfolabs/Desktop/soft/android-sdk-mac_x86/platform-tools:$PATH
then run:
adb shell logcat > log.txt
OR first move to adb platform-tools:
cd /Users/user/Android/Tools/android-sdk-macosx/platform-tools
then run
./adb shell logcat > log.txt
I would use something like:
$ adb logcat --pid=$(adb shell pidof com.example.yourpackage)
which you can then redirect to a file
$ adb logcat --pid=$(adb shell pidof com.example.yourpackage) > log.txt
or if you also want to see it at stdout as well:
$ adb logcat --pid=$(adb shell pidof com.example.yourpackage) | tee log.txt

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