Quick Guide to Android ADB (Shallow Thoughts)

Akkana's Musings on Open Source Computing and Technology, Science, and Nature.

Mon, 09 Apr 2012

Quick Guide to Android ADB

I've been fiddling with several new Android devices, which means I have to teach myself how to use adb all over again.

adb is the Android Debug Bridge, and it's great for debugging. It lets you type commands on your desktop keyboard rather than tapping them into the soft keyboard in Android's terminal emulator, it gives you a fast way to install apps, and most important, it lets you get Java stack traces from crashing programs.

Alas, the documentation is incomplete and sometimes just plain wrong. Since I don't need adb very often, I always forget how to use it between sessions, and it takes some googling to figure out the tricks. Here are the commands I've found most helpful.

Start the server

First you have to start the adb, and that must be done as root. But adb isn't a system program and probably lives in some path like /home/username/path/to/android-sdk-linux_x86/tools. Even if you put it in your own path, it may not be in root's. You can probably run it with the explicit path:

$ sudo /path/to/android-sdk-linux_x86/tools/adb start-server
or you can add it to root's path:
# export PATH=$PATH:/path/to/android/android-sdk-linux_x86/tools
# adb start-server

If you're also running eclipse, that probably won't work the first time, because eclipse may also have started an adb server (that gets in the way when you try to run adb manually). if you don't see "* daemon started successfully *", try killing the server and restarting it:

# adb kill-server
# adb start-server
* daemon not running. starting it now on port 5037 *
* daemon started successfully *

Keep trying until you see that "* daemon started successfully *" message.


$ adb usb

Occasionally, this will give "error: closed". Don't panic -- sometimes this actually means "I noticed something connected on USB and automatically connected to it, so no need to connect again." It's mysterious, and no one seems to have an explanation for what's really happening. Anyway, try running some adb commands and you may find you're actually connected.

Shell and install

The most fun is running an interactive shell on your Android device.

$ adb shell
It's just busybox, not a full shell, so you don't have nice things like tab completion. But it's still awfully useful.

You can also install apps. On some devices (like the Nook, where I haven't found a way to allow install from non-market sources), it's the only way to install an apk file.

$ adb install /path/to/appname.apk

If the app is already installed, you'll get an error. Theoretically you can also do adb uninstall first, but when I tried that it just printed "Failure". But you can use -r for "reinstall":

$ adb install -r /path/to/appname.apk

There is no mention of either uninstall or -r in the online adb documentation, though adb -h mentions it.

Update: To uninstall, you need the full name of the package. To get the names of installed packages (another undocumented command), do this: adb shell pm list packages

Debug crashes with logcat

Finally, for debugging crashes, you can start up a logcat and see system messages, including stack traces from crashing apps:

$ adb logcat

Logcat is great for fixing reproducible crashes. Sadly, it's not so good for random/sporadic crashes that happen during the course of using the device.

You're supposed to be able to do adb logcat -s AppName if you're only interested in debugging messages from one app, but that doesn't work for me -- I get no output even when the app runs and crashes.

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[ 11:32 Apr 09, 2012    More tech | permalink to this entry | comments ]
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