Efficiency and fun from using ADB Shell, Part 2 - I/O

Continuing this series of articles I want to tell more about basic input and output provided by Android Debug Bridge.


Pretty often happening that we need enter specific data to register/login/connect into our application. Thankfully we can do it easily with adb. To input user/pass we use flag text and to go to second EditText key event

adb shell input text username;
adb shell input keyevent 20;
adb shell input text username;

We can enter set of commands either sequentially either pass all commands for shell inside of quotes, depends on design of our layout we may need to go up/down between `EditTexts`  

adb shell "input text 2; input keyevent 20; input text 1; 
input keyevent 20; input keyevent 20; input text; 
input keyevent 19; input keyevent 19; input text 7050;"
Sometimes it may help to avoid hassle of entering data every time. ![Input text with adb](/images/2/input.gif "Input text with adb") Thanks for Rene Barbosa we can see [full list of keyevents](http://stackoverflow.com/a/28969112/1823992) plus use of `swipe` and `tap` flags. We can mix commands as we wish for example to **unlock screen**:
//26 -->  "KEYCODE_POWER" 
adb shell "input keyevent 26; input swipe 200 700 200 0;"
It might be come in handy to add in gradle build script like a last task for example:  
def wakeUpViaAdb() {
  exec {
    //put your own shell
    executable "zsh"
    args "-c", 'if (($(adb devices | wc -l) < 4)); then adb \
shell "input keyevent 26; input swipe 200 700 200 0;"; fi'

android.applicationVariants.all { variant ->
    variant.assemble.doLast {
## Output We can use several information channels for output with adb `logs`, `screenshot`, `screen record` ### Logs To see logs we can use embedded adb command `log cat`. Mixing with `tag`, `priority` flags and tool `grep` we can get any information listed in logs.
//TAG:priority(V/D/I/W/E), we will see verbose priority logs with tag WifiStateMachine
adb logcat -s WifiStateMachine:V 
 But I considering to be more convenient to use [PID Cat](https://github.com/JakeWharton/pidcat) by Jake Wharton because of highlighting priority with colours and look up by a package. It just python script and could be run easy everywhere.    

  ![PID Cat](/images/2/pidcat.png)  
### Screenshots    

adb shell screencap -p /sdcard/screenshot.png && adb pull /sdcard/screenshot.png  

We can also use nicer one-liner getting output [straight away](http://blog.shvetsov.com/2013/02/grab-android-screenshot-to-computer-via.html)  
adb shell screencap -p | perl -pe 's/\x0D\x0A/\x0A/g' > screenshot.png  

### Recording screen  
Starting from version of Android 4.4 we can record screen. Keep in mind that it's not available on emulators.  

//size for resolution, time-limit time of recording in seconds
adb shell screen record /sdcard/temp.mp4 --size 1280x720 --time-limit 5

There is also very useful gist to make [gif](https://gist.github.com/lorenzos/e8a97c1992cddf9c1142) out of a video.

These are the basic input/output commands for adb. In next Part, I’ll tell more useful tips and tricks about adb and Android. Stay tuned and keep investigating this wonderful Android World! ;)  
Written on January 2, 2016