[UNIVERSAL][LOGCAT]How to get & read a logcat/ Troubleshoot your own issues!

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Vivek_Neel

Inactive Recognized Contributor / Themer
Dec 23, 2012
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Its because the device didn't start booting.. it happens.. log service is not started yet.. so you can't take log at that situation.

______________________________________
Jokes gets more serious thought, than serious words these days:(

Oh...sorry

I was trying it when the device was on..lol:D

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Kalpit Nathwani

Senior Member
Apr 13, 2012
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Hello Stryke_the_Orc

Can you plese tell me how to take logcat while my phone is stuck at boot loop. I am trying to port Miui Rom.

Thanks
Kalpit Nathwani
 

Stryke_the_Orc

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Hello Stryke_the_Orc

Can you plese tell me how to take logcat while my phone is stuck at boot loop. I am trying to port Miui Rom.

Thanks
Kalpit Nathwani

In terminal cd to the tools folder in your sdk directory and type monitor. Watch the upper left hand box for your device to show up and when you see the system partition appear click on it. You should then be able to grab a logcat. To get the logs, click the logcat button in the bottom left box. However, this will only work if your device will boot far enough for the system to become active, be patient as it can sometimes take more than one bootloop cycle for the system to appear.

Slithering from the nether regions of a twisted mind and tarnished soul



Edit - I've logged into my pc and taken these screenshots for you, I will also attach them to the op for future reference.
 

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Stryke_the_Orc

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Oh...sorry

I was trying it when the device was on..lol:D

Sent from my GT-I9100 using Tapatalk 2

If adb is telling you that its waiting on the device, while you're up and running, then its one of two things. Either usb debugging isn't enabled on your device, or you don't have the proper device drivers on your computer. Both of these are absolute MUST HAVE items to grab a logcat.:good:
 
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Kalpit Nathwani

Senior Member
Apr 13, 2012
53
9
Hello Stryke_the_Orc

Sir Thanks for your quick reply.

Can you please help me and clarify few more things:

1) How much time it will take to complete one bootloop cycle.
2) If device is not detected by system then what is the solution for this problem.

Sorry for my noob question but i am new to porting ROM

Once again thanks for your help.

Thanks
Kalpit Nathwani
 

Stryke_the_Orc

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Hello Stryke_the_Orc

Sir Thanks for your quick reply.

Can you please help me and clarify few more things:

1) How much time it will take to complete one bootloop cycle.
2) If device is not detected by system then what is the solution for this problem.

Sorry for my noob question but i am new to porting ROM

Once again thanks for your help.

Thanks
Kalpit Nathwani

How long it takes to complete a bootloop cycle will depend on how far your device gets before it encounters the error. Typically when you see the boot animation begin to replay is when the cycle has started again.
If your device doesn't turn up a system partition using monitor, then you'll need to reflash a working rom. If you read up a few posts, I have linked a tutorial on how to use the android emulator to test custom roms without risking your device. I would try that method and see what information you can gather from the debugging process:good:
 

Slimegod

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Mar 12, 2011
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Are you trying to read it, or figure out the error?

I'd love to help, but I need to know what you're trying to do;)

Slithering from the nether regions of a twisted mind and tarnished soul

Actually both. Was just looking at it now. I can somewhat see where the errors are but not to sure. It's a lot of "D" and seems like those are errors based off what u said in the op

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Stryke_the_Orc

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Actually both. Was just looking at it now. I can somewhat see where the errors are but not to sure. It's a lot of "D" and seems like those are errors based off what u said in the op

Sent from my SPH-L710 using XDA Premium 4 mobile app

"D" is Dalvik logging, You can see some information here that will help you pin down errors, but they are not the errors themselves. Basically, Dalvik is every process your device is running.

Your also showing a lot of "W" (Warnings) for resources, but if you read further into the line you'll see that it says "Changes with Configuration" so this is nothing to worry about.

Your errors are here
Code:
E/BatteryService(26335): wirelessOnlinePath not found
E/dalvikvm(26335): ERROR: couldn't find native method
E/dalvikvm(26335): Requested: Lcom/android/server/location/GpsLocationProvider;.
native_agps_set_ref_location_cellid:(IIIIII)V
E/dalvikvm(26335): Candidate: Lcom/android/server/location/GpsLocationProvider;.
native_agps_set_ref_location_cellid:(IIIII)V
E/JNIHelp (26335): RegisterNatives failed for 'com/android/server/location/GpsLo
cationProvider', aborting
F/libc    (26335): Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1), thread 2633
5 (system_server)

Your wireless path looks to be corrupted, but it gives no other information, for this you could find where your battery service resides and compare your files with stock files to see what's missing or changed. (This could also be a partial line of code where something was removed by the provider or manufacturer, usually for a feature your device doesn't have)

The errors that start E/dalvikvm show that your device is looking for a method that doesn't exist. You do however have a method that is close (noted by the Candidate tag) the only difference being cellid:(IIIII)V & cellid:(IIIIII)V. Your device is looking for a method that has extra characters in the method call out. if you change the last part of that line to match the call out.

The last one is something I'm unfamiliar with, sorry :(
 

Slimegod

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Mar 12, 2011
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Ok I see. Well I'm trying to port between carriers. I don't know if your familiar porting at all. Don't want to elaborate about what I'm trying to do if your not familiar with it. So do you know how to correct those errors? If so can you assist me.

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Stryke_the_Orc

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Ok I see. Well I'm trying to port between carriers. I don't know if your familiar porting at all. Don't want to elaborate about what I'm trying to do if your not familiar with it. So do you know how to correct those errors? If so can you assist me.

Sent from my SPH-L710 using XDA Premium 4 mobile app

I'm familiar with porting, that's how I taught myself to understand a logcat;)

In my last post I told you how to fix your errors. Except for the last one that I'm not familiar with. The tricky part will be locating the files. That's pretty much a guessing game unless you know which apks these folder paths are in.

Slithering from the nether regions of a twisted mind and tarnished soul
 

Slimegod

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Mar 12, 2011
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I'm familiar with porting, that's how I taught myself to understand a logcat;)

In my last post I told you how to fix your errors. Except for the last one that I'm not familiar with. The tricky part will be locating the files. That's pretty much a guessing game unless you know which apks these folder paths are in.

Slithering from the nether regions of a twisted mind and tarnished soul

Not to familiar where the files are lol. But the ROM I'm porting is miui. My base isn't a existing rom its a brand new cm 10.1.3 base. So yeah it may be some files that have to be put in. From whether it's existing base ROM or a port I don't know. But I'm getting hung on the boot animation. The whole reason why I'm using a brand new cm base is the ROM I ported previous to this the phone would fc when the other person would hang up. Something minor but still wanted to know what the cause was. Was told it was the cm base I was using and it had to be updated so here I am lol.

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Stryke_the_Orc

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Not to familiar where the files are lol. But the ROM I'm porting is miui. My base isn't a existing rom its a brand new cm 10.1.3 base. So yeah it may be some files that have to be put in. From whether it's existing base ROM or a port I don't know. But I'm getting hung on the boot animation. The whole reason why I'm using a brand new cm base is the ROM I ported previous to this the phone would fc when the other person would hang up. Something minor but still wanted to know what the cause was. Was told it was the cm base I was using and it had to be updated so here I am lol.

Sent from my SPH-L710 using XDA Premium 4 mobile app

Ok well, first places is look is framework.jar and services.jar those will be the most likely places for that file path. Your other option would be to decompile all the apks and search for the smali file named then edit that.

Slithering from the nether regions of a twisted mind and tarnished soul
 

Stryke_the_Orc

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Lcom/android/server/location/GpsLocationProvider;.
native_agps_set_ref_location_cellid: (IIIIII)V

This breaks down as smali/com/location/GPSLocationProvider.smali with the method being native_agps_set_ref_location_cellid: (IIIIII)V and you'd edit (IIIIII) to (IIIII)

I'd be willing to bet it's in framework.jar

Edit - I added spaces so that it didn't turn into an emoticon;)

Slithering from the nether regions of a twisted mind and tarnished soul
 
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Slimegod

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Lcom/android/server/location/GpsLocationProvider;.
native_agps_set_ref_location_cellid: (IIIIII)V

This breaks down as smali/com/location/GPSLocationProvider.smali with the method being native_agps_set_ref_location_cellid: (IIIIII)V and you'd edit (IIIIII) to (IIIII)

I'd be willing to bet it's in framework.jar

Edit - I added spaces so that it didn't turn into an emoticon;)

Slithering from the nether regions of a twisted mind and tarnished soul


Ok. Does that seem like the only problem?

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    DUE TO REAL LIFE TIME CONSTRAINTS I AM UNABLE TO CONTINUE READING AND DIAGNOSING LOGS FOR MEMBERS. PLEASE USE THIS THREAD AS INTENDED, AS A STARTING POINT IN LEARNING TO READ THESE LOGS AND DIAGNOSE PROBLEMS YOURSELF. THANK YOU!




    The Basics

    I'm starting this thread in hopes of sharing some very useful information to all our new members and hopefully either teaching something new or being a good refresher for our experienced members. I've been asked before how to tell what errors are present in logcats, how I can understand all that mess, etc...

    Well, I'm going to try my best to explain all of it. In this way, you can get your own logs and try to fix the problems, or know exactly what is causing your problems to help out the developers so they aren't looking through thousands of lines of code for each persons issue.

    Help us help you!

    ATTENTION:
    Due to the recent feature in the portal, my thread has become increasingly popular, and as such I am getting a lot of requests for help. You may post your logs here, but please do so in either pastebin format, or use hide tags. Please DO NOT request help via pm. This is for a couple of reasons:
    1. I can't keep up with all the requests.
    2. Your logs may be solved by another member, I have requested that any willing RC's, RD's, Moderators, or members willing to help, to do so.
    3. If you post your logs here, any member may look at it and help you solve them.
    Thank you.


    To begin with, we'll need to have some understanding of adb. Check out this thread by @bigtoysrock and be sure to thank him!

    Logcats

    First, we'll need to know how to get a logcat. With the plethora of new users this has been the subject of many, many discussions. When asked to get a logcat, they don't know how.


    Tools and Requirements

    First of all, you'll absolutely NEED to have usb debugging enabled. To do this go to SETTINGS, navigate down to DEVELOPER OPTIONS and select it, if they are not on use the toggle in the top right corner and select USB DEBUGGING ( See attached screen shots )

    Secondly, you'll absolutely NEED to have the ANDROID SDK grab it here
    Install the SDK on the root of your computer. DO NOT change the SDK name to include any spaces as it will fail!

    Also be sure to grab your device specific drivers, if they aren't already installed. Some devices will install them automatically, while others require a simple google search.

    Now that you've got everything you need, lets grab a logcat!

    Update: 15 Second ADB installer for windows is an excellent alternative for the above instructions, and while you're there be sure to thank @Snoop05

    How to get a Logcat

    Windows
    Navigate to where you've installed the sdk. Once you've gotten into the sdk, you're going to look for "PLATFORM TOOLS" folder, inside hold shift + right click on any empty space, select "OPEN COMMAND WINDOW HERE"
    Connect your phone to your PC via usb cable, in the command window type "adb devices" without the quotes. If you've set everything up properly it should return an alpha-numeric value, this is your device ID. If not, you've missed a step or installed sdk in the wrong manner. Go back and double check your steps.

    Now that we know you're connected there are a few options, you can run the logcat in command window, or you can export it to a .txt file.

    To see the log in command window just type "adb logcat" (again no quotes) and the log will scroll through your screen. To stop scrolling so you can investigate hit ctrl + c

    To export to a .txt file (I personally prefer this method) type "adb logcat > logcat.txt". You can name the logcat anything you want, for example "adb logcat > MyError.txt" just be sure not to include spaces or special characters in the name of the file.



    MAC/Linux

    "Instructions:

    Install your device driver for using adb. Everything you need will you find here
    Download adb executable for your OS (Download: Windows | Linux | Mac). Paste it somewhere.
    Connect your android device.
    Verify if "Settings > Developer options > USB debugging" is checked, if not, simply check it.
    Open a command promt (windows) or terminal (linux / mac). How to do it: On Windows: windows + r > enter "cmd" (without quotes) > click enter | On Linux: You don't know how to open a terminal? LOL | On Mac: Type Terminal into Spotlight and open it
    CD to the directory where the adb executable is located. On Windows: Go to the directory where you downloaded the adb executable, Shift+Right Click and select "Open Console" (or similar) | On Linux / Mac: Rightclick in the directory and select "Open Terminal here" (or simply CD into the directory)
    Type in your cmd/terminal: adb devices to verify your device is properly connected.
    If your device is properly selected, type in adb logcat to show the mighty and magic logcat aka stacktrace.
    Reproduce your error (or whatever) on your device.
    Right after, paste the whole cmd / terminal window into a paste-service like http://pastebin.com/ and send it to us." - Quoted from Leandros here
    93
    Reading and understanding logcat output

    Reading a Logcat

    Ok, so now we have our log but what do we do with it?
    There are a few things that you need to know before you'll understand what is what.
    Preceding every line in a logcat is a class, you can learn about them here.
    These will look like this and I have placed the meaning next to each:
    Code:
    E/       Error - I would hope this is self explanatory
    F/       Fatal Error - Again pretty self explanatory
    I/        Information - This is pretty tricky, the information class shows what the system is doing, but it can also show you errors so read it carefully!
    D/      Dalvikvm - This class will show what the dalvik processes are doing, but can also show you where mistakes are
    W/     Warning - Warnings are basically errors, but less severe. Usually it will show you missing resources, conflicting or missing paths, etc...
    V/      Verbose - Basically everything the phone is doing
    S/      Silent - You will not see silent


    Ok so lets see some examples. Some of these will be more in-depth than others simply because there is more to it.

    Code:
    [COLOR="Red"]D/dalvikvm( 1853): DexOpt: --- BEGIN 'core.jar' (bootstrap=1) ---[/COLOR]
    Here we see that the dalvik process has begun to optimize our system files.
    
    [COLOR="red"]D/dalvikvm( 2162): DexOpt: 'Lcom/sec/android/seccamera/SecCamera$OnMultiFrameShotEventListener;' has an earlier definition; blocking out[/COLOR]
    Here you can see that the Dalvik process has already defined the called method, and is skipping the optimization
    
    [COLOR="red"]I/PackageManager( 2130): /system/app/sCloudSyncBrowser.apk changed; collecting certs[/COLOR]
    The information class is showing that there has been a change made to this apk, and is verifying the signature.
    
    [COLOR="red"]W/ResourceType( 2130): Failure getting entry for 0x7f050020 (t=4 e=32) in package 0 (error -75)
    
    D/PhoneStatusBar( 2792): Added status bar view
    
    D/PhoneStatusBar( 2792): disable: < expand icons alerts ticker system_info back home recent clock >
    
    W/PackageManager( 2130): Failure retrieving xml 0x7f050020 in package com.maxmpz.audioplayer
    
    W/PackageManager( 2130): android.content.res.Resources$NotFoundException: Resource ID #0x7f050020
    
    W/PackageManager( 2130): at android.content.res.Resources.getValue(Resources.java:1339)
    
    W/PackageManager( 2130): at android.content.res.Resources.loadXmlResourceParser(Resources.java:2445)
    
    W/PackageManager( 2130): at android.content.res.Resources.getXml(Resources.java:1227)
    
    W/PackageManager( 2130): at android.app.ApplicationPackageManager.getXml(ApplicationPackageManager.java:1080)
    
    W/PackageManager( 2130): at android.content.pm.PackageItemInfo.loadXmlMetaData(PackageItemInfo.java:227)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.parseProviderInfoXml(AppWidgetServiceImpl.java:1264)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.addProviderLocked(AppWidgetServiceImpl.java:1162)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.loadAppWidgetList(AppWidgetServiceImpl.java:1148)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.ensureStateLoadedLocked(AppWidgetServiceImpl.java:391)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.systemReady(AppWidgetServiceImpl.java:211)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetService.systemReady(AppWidgetService.java:156)
    
    W/PackageManager( 2130): at com.android.server.ServerThread$1.run(SystemServer.java:1882)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService.systemReady(ActivityManagerService.java:8250)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService$9$1.run(ActivityManagerService.java:8152)
    
    W/PackageManager( 2130): at android.os.Handler.handleCallback(Handler.java:615)
    
    W/PackageManager( 2130): at android.os.Handler.dispatchMessage(Handler.java:92)
    
    W/PackageManager( 2130): at android.os.Looper.loop(Looper.java:137)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService$AThread.run(ActivityManagerService.java:1563)
    
    W/ResourceType( 2130): Failure getting entry for 0x7f050021 (t=4 e=33) in package 0 (error -75)
    
    W/PackageManager( 2130): Failure retrieving xml 0x7f050021 in package com.maxmpz.audioplayer
    
    W/PackageManager( 2130): android.content.res.Resources$NotFoundException: Resource ID #0x7f050021
    
    W/PackageManager( 2130): at android.content.res.Resources.getValue(Resources.java:1339)
    
    W/PackageManager( 2130): at android.content.res.Resources.loadXmlResourceParser(Resources.java:2445)
    
    W/PackageManager( 2130): at android.content.res.Resources.getXml(Resources.java:1227)
    
    W/PackageManager( 2130): at android.app.ApplicationPackageManager.getXml(ApplicationPackageManager.java:1080)
    
    W/PackageManager( 2130): at android.content.pm.PackageItemInfo.loadXmlMetaData(PackageItemInfo.java:227)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.parseProviderInfoXml(AppWidgetServiceImpl.java:1264)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.addProviderLocked(AppWidgetServiceImpl.java:1162)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.loadAppWidgetList(AppWidgetServiceImpl.java:1148)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.ensureStateLoadedLocked(AppWidgetServiceImpl.java:391)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetServiceImpl.systemReady(AppWidgetServiceImpl.java:211)
    
    W/PackageManager( 2130): at com.android.server.AppWidgetService.systemReady(AppWidgetService.java:156)
    
    W/PackageManager( 2130): at com.android.server.ServerThread$1.run(SystemServer.java:1882)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService.systemReady(ActivityManagerService.java:8250)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService$9$1.run(ActivityManagerService.java:8152)
    
    W/PackageManager( 2130): at android.os.Handler.handleCallback(Handler.java:615)
    
    W/PackageManager( 2130): at android.os.Handler.dispatchMessage(Handler.java:92)
    
    W/PackageManager( 2130): at android.os.Looper.loop(Looper.java:137)
    
    W/PackageManager( 2130): at com.android.server.am.ActivityManagerService$AThread.run(ActivityManagerService.java:1563)[/COLOR]
    Here is a great example of the warning class showing missing resources.
    
    [COLOR="red"]I/dalvikvm( 1853): Could not find method android.app.IActivityManager.resizeArrangedWindow, referenced from method android.app.ActivityManager.resizeArrangedWindow
    
    W/dalvikvm( 1853): VFY: unable to resolve interface method 3769: Landroid/app/IActivityManager;.resizeArrangedWindow (IILandroid/graphics/Rect;)Landroid/graphics/Rect;
    
    D/dalvikvm( 1853): VFY: replacing opcode 0x72 at 0x0004[/COLOR]
    A prime example of Information class showing an "error", these will usually be listed in information class if they don't have a great impact of the functionality of the device.
    
    [COLOR="red"]F/PackageManager( 2014): Unable to backup package manager settings,  current changes will be lost at reboot
    E/DropBoxManagerService(2014):  Can't write: system_server_wtf
    E/DropBoxManagerService(2014):  java.io.FileNotFoundException: /data/system/dropbox/drop21.tmp: open failed: EROFS (Read-only file system)
    E/DropBoxManagerService(2014):  at libcore.io.IoBridge.open(IoBridge.java:416)
    E/DropBoxManagerService(2014):  at java.io.FileOutputStream.(FileOutputStream.java:88)
    E/DropBoxManagerService(2014):  at java.io.FileOutputStream.(FileOutputStream.java:73)
    E/DropBoxManagerService(2014):  at com.android.server.DropBoxManagerService.add(DropBoxManagerService.java:208)
    E/DropBoxManagerService(2014):  at android.os.DropBoxManager.addText(DropBoxManager.java:272)
    E/DropBoxManagerService(2014):  at com.android.server.am.ActivityManagerService$13.run(ActivityManagerService.java:8281)
    E/DropBoxManagerService(2014):  at com.android.server.am.ActivityManagerService.addErrorToDropBox(ActivityManagerService.java:8288)
    E/DropBoxManagerService(2014):  at com.android.server.am.ActivityManagerService.handleApplicationWtf(ActivityManagerService.java:8099)
    E/DropBoxManagerService(2014):  at com.android.internal.os.RuntimeInit.wtf(RuntimeInit.java:329)
    E/DropBoxManagerService(2014):  at android.util.Log$1.onTerribleFailure(Log.java:103)
    E/DropBoxManagerService(2014):  at android.util.Log.wtf(Log.java:278)
    E/DropBoxManagerService(2014):  at android.util.Log.wtf(Log.java:255)
    E/DropBoxManagerService(2014):  at com.android.server.pm.Settings.writeLPr(Settings.java:1115)
    E/DropBoxManagerService(2014):  at com.android.server.pm.PackageManagerService.unloadMediaPackages(PackageManagerService.java:9314)
    E/DropBoxManagerService(2014):  at com.android.server.pm.PackageManagerService.updateExternalMediaStatusInner(PackageManagerService.java:9128)
    E/DropBoxManagerService(2014):  at com.android.server.pm.PackageManagerService.access$3800(PackageManagerService.java:165)
    E/DropBoxManagerService(2014):  at com.android.server.pm.PackageManagerService$10.run(PackageManagerService.java:9017)
    E/DropBoxManagerService(2014):  at android.os.Handler.handleCallback(Handler.java:615)
    E/DropBoxManagerService(2014):  at android.os.Handler.dispatchMessage(Handler.java:92)
    E/DropBoxManagerService(2014):  at android.os.Looper.loop(Looper.java:137)
    E/DropBoxManagerService(2014):  at android.os.HandlerThread.run(HandlerThread.java:60)
    E/DropBoxManagerService(2014):  Caused by: libcore.io.ErrnoException: open failed: EROFS (Read-only file system)
    E/DropBoxManagerService(2014):  at libcore.io.Posix.open(Native Method)
    E/DropBoxManagerService(2014):  at libcore.io.BlockGuardOs.open(BlockGuardOs.java:110)
    E/DropBoxManagerService(2014):  at libcore.io.IoBridge.open(IoBridge.java:400)
    E/DropBoxManagerService(2014):  ... 20 more[/COLOR]
    Here we have the Fatal and Error classes.

    Ok, so now we have seen some examples, lets learn to decipher them:highfive:

    The beautiful thing about these logs is that they tell you exactly what and where everything is, as long as you know what you're looking at.
    I'm only going to use the one line to show you how to read a log, as the format is exactly the same for any class.
    Code:
    E/DropBoxManagerService(2014):  at com.android.server.am.ActivityManagerService.addErrorToDropBox(ActivityManagerService.java:8288)
    
    So here we have the printed error from logcat, the format used is as follows
    Class/Process/Location
    [b]Important! The log WILL NOT tell you what apk or jar the error occurs in, this is the hardest part of debugging![/b]
    
    In the above error we see
    Class = E/
    Process = DropBoxManagerService
    Location = com.android.server.am.ActivityManagerService.addErrorToDropBox(ActivityManagerService.java:8288) (Folder directory.File Name. Method)
    
    I know from all my digging that the specified path is in services.jar so once I have services.jar decompiled I'll follow the path laid out. (Decompile "apkname".odex for odexed roms and classes.dex for deodexed roms)
    These paths will always be located in the smali folder! For example I open my classes.dex folder after decompiling and see a smali folder, I'll open that and then I have options. The . after every word is a folder directory ( same as / in your computer directory )
    The specified path says com. so I'll open the com folder, next I'm directed to android, then server, then am folder.
    Now I should see a bunch of files and possibly some folders, [b]if there is no folder name that matches the next directory it is a file![/b]
    ActivityManagerService is a filename, so I'll open that file using NotePad++ and search for the specified method which is addErrorToDropBox.
    From here I can use another file to compare the lines to find my error, or I can know exactly where the error occured and report my problem to a helpful dev or member.

    I hope that this has been a good learning experience and will help you to understand any issues you are facing.
    :victory:
    70
    Bootloops and Filtering your logs

    Getting a Logcat during the dreaded Bootloop

    The only difference between grabbing a logcat while running and grabbing one during a bootloop is the program you're going to use. Instead of the standard adb bridge, we'll be using the adb monitor tool. You can find this tool under the "TOOLS" folder. Open the "Tools" folder, right click on any empty space and select "Open Command Window Here"
    Once the window is open, type "monitor" (without the quotes) and press enter. A whole new program will open listing the device ID and subfolders (your devices partitions)
    IMPORTANT! The device ID may not show up right away, THIS IS OK! I found that it took about three bootloop cycles to actually connect.
    Once you see the device ID, within a few seconds you should see the "system" partition listed underneath. Select it.
    Down in the bottom left corner select the "Logcat" tab. From here, you can grab the logcat in a txt format or just watch it scroll.
    I have taken screenshots of the process, and are available here

    There's a great guide here that goes a little more in depth and has updated information about the requirements for a log during bootloops.


    How to Filter your Logcat

    Lets say you want to find only the logs for a specific app or process, searching through thousands of lines can be a pain. Luckily, adb allows you to filter your logs based on application tags!
    Here's how:
    Code:
    adb logcat ActivityManager:I MyApp:D *:S

    This filter basically says "Show me only logs for ActivityManager at an Information or above level, and all logs for 'MyApp' with a priority level of Debug and higher" The *:S is important here, this makes all other tags Silent so that it ensures only the filtered tags are shown in your log.How's that for handy?


    Demesg (kernel) Logs

    For a demesg log you'll want to follow the same instructions as above to get into adb terminal.
    Once there, type adb devices to verify you're connected. Now you can pull a log by simply typing "adb shell dmesg > dmesg.txt" (without the quotatons" This will place the logs in the same folder that you launched terminal from (platform-tools)

    Also, for more detailed information and a few other useful commands check out this site
    49
    Apps and Reference

    Apps for grabbing Logcats


    Mobile Apps

    alogcat

    This app is great for seeing your logs, especially on older Android versions. The biggest issue I have with this app is that the share function doesn't work properly on jellybean. Yet...
    You can grab it here

    CatLog

    I personally have no experience with this app, but it's highly rated in Play Store and has an easy to use User Interface.
    Grab it here

    getlogs

    This is my favorite of these apps, I can use it to grab almost any log I want. Highly recommended for any developer, themer, or enthusiast!
    Simple, clean, effective. The way getting your logs should be:D
    Grab it here

    Logcat Reader

    Grab it here

    Logcat Extreme

    This one looks pretty cool, it has a "floating logcat" feature. Grab it here


    PC Applications

    A pretty neat logcat tool is AIOlog found here, contains versions for Windows, Linux and MacOS's by 32 and 64 bit systems.


    Here's a neat tool for you windows users, an AIO Logcat manager. Grab it, and view the orignal thread here

    Another for you windows users, Easy Logcat Maker is an executable GUI that looks pretty neat.

    Another cool logging tool is here created by the genius behind VTS!

    A new Windows tool by @FuzzyMeep Two, the aptly named Logcat Tool will parse your logcat to show you how many of each entry your logs contain, and then it organizes your logs into separate files based on the type of entry (Warning, Error, Verbose, etc...), and more! This could easily become my favorite desktop method of grabbing logs.
    Misc. Apps and Tools

    For those of you using linux there is a neat tool that color codes your logcat output to make it easier to read. You can find it here

    Not a logcat app, per se, but a pretty entertaining and live logcat boot animation courtesy of @Chainfire can be found here. Download it and see your device boot in real time!


    There are a lot more apps available than what I've covered here. These are simply the most widely known (possibly with the exception of getlogs) and widely used/recommended. If you find or make any more of these apps, please feel free to post the link here and share with the community!

    PLEASE NOTE THAT IT IS AGAINST XDA RULES TO LINK TO PAID APPS, SO DO NOT LINK TO PAID SERVICES OR THE POST WILL BE REPORTED AND LIKELY REMOVED

    Reference Links:
    Googles Logcat Help Pages
    How to get useful logs by tonyp
    Guide to logcats provided by Deadly
    Color Coding Your Logcat World


    Please be sure to thank the developers of these fantastic tools for their time and efforts!
    24
    For some reason every time I try to run a logcat I get this

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