add android section

sysadmin/README.md

@@ -3,6 +3,7 @@
 SysAdmin notions, tools and procedures.
 
 - [Linux](linux/README.md)
+- [Android](android/README.md)
 - [Raspberry PI Setup](rpi-setup.md)
 - [OpenSSH for Windows](win-openssh.md)
 - [Microsoft SQL Server](ms-sqlserver.md)

sysadmin/android/README.md

@@ -0,0 +1,5 @@
+# Android world
+
+- [adb snippets](adb-snippets.md)
+- [fastboot snippets](fastboot-snippets.md)
+- [emulator](emulator.md)

sysadmin/android/adb-snippets.md

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+# Android Debug Bridge (adb) snippets
+
+## Poweroff the phone
+
+```shell
+adb shell reboot -p
+```
+
+## Kill the running ADB server
+
+```shell
+adb kill-server
+```
+
+## List devices
+
+```shell
+adb devices
+```
+
+## Run a command specifically for the running emulator or the connected physical device
+
+```shell
+adb -d <command> # command for device
+adb -e <command> # command for emulator
+adb -s <deviceid> # specify target
+# or just set an environment variable ANDROID_SERIAL='<deviceid>'
+```
+
+## Shell commands
+
+### Open the shell
+
+```shell
+adb shell
+```
+
+### (Un)Install an app
+
+```shell
+adb install file.apk
+adb uninstall com.app.www
+```
+
+### Start (open) an app
+
+```shell
+adb shell monkey -p com.app.www 1 # starts main activity (opens the app, usually)
+```
+
+## Wifi ADB
+
+```powershell
+# 192.168.1.34 is the LAN IP of the android device
+adb pair 192.168.1.34:38437
+adb connect 192.168.1.34:35645
+```

sysadmin/android/emulator.md

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+# Android Emulator
+
+References
+
+> - <https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels>
+> - <https://apilevels.com/>
+
+## Setup
+
+One time setup.
+In the examples, "Pixel4_api30_android11_x64" is the name of the emulator being created.
+In the examples, android api level 30 is used, which is android 11 (see references above).
+
+All commands are in Powershell syntax.
+
+### Install tools, platform, system image
+
+```Powershell
+sdkmanager platform-tools
+sdkmanager "build-tools;30.0.3"
+sdkmanager "platforms;android-30"
+sdkmanager "system-images;android-30;google_apis;x86_64"
+```
+
+### Create emulator
+
+```powershell
+# avdmanager create avd -n <name> -k "system-images;android-<api level>;google_apis;x86_64"
+avdmanager create avd -n Pixel4_api30_android11_x64 -k "system-images;android-30;google_apis;x86_64"
+
+# check if all is well
+emulator -list-avds
+```
+
+### `config.ini` useful settings
+
+Add the following settings to the emulator's configuration file, located at:
+
+> `<$env:USERPROFILE>\.android\avd\<emulator name>\config.ini`
+
+So, in the example:
+
+> `C:\Users\username\.android\avd\Pixel4_api30_android11_x64.avd\config.ini`
+
+- `nhw.lcd.width = 720` and `nhw.lcd.height = 1280` set the resolution to 720p
+- `nhw.lcd.density = 240` sets DPI to an acceptable level
+- `nhw.keyboard = yes` is needed for full functioning of the computer keyboard (eg. copy-pasting)
+
+## Run the emulator
+
+Just run this command every time you have to start the emulator.
+
+```powershell
+# emulator -avd <emulator name>
+emulator -avd Pixel4_api30_android11_x64
+```

sysadmin/android/fastboot-snippets.md

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+# fastboot-snippets.md
+
+## Poweroff the phone
+
+NB: works only if the OEM command is supported.
+
+```shell
+fastboot oem poweroff
+```