[ C / C++ ] : Byte Array to Hex String

     int index;

     char hexString[512];

     memset(hexString, 0x0, sizeof(hexString));

     for (index = 0; index < byteArray.length; ++index) {

          sprintf(hexString+index*3, "%02X ", byteArray[index]);

     }

     printf("Hex String : %s\n", hexString);

[ Android ] : Monkey test

example :

adb shell monkey -p com.package.name --throttle 100 -s 43686 -v 50000

-p           : package name
--throttle : interval between event
-s           : random seed
-v           : number of simulated event

others:
================================================================
usage: monkey [-p ALLOWED_PACKAGE [-p ALLOWED_PACKAGE] ...]
              [-c MAIN_CATEGORY [-c MAIN_CATEGORY] ...]
              [--ignore-crashes] [--ignore-timeouts]
              [--ignore-security-exceptions]
              [--monitor-native-crashes] [--ignore-native-crashes]
              [--kill-process-after-error] [--hprof]
              [--pct-touch PERCENT] [--pct-motion PERCENT]
              [--pct-trackball PERCENT] [--pct-syskeys PERCENT]
              [--pct-nav PERCENT] [--pct-majornav PERCENT]
              [--pct-appswitch PERCENT] [--pct-flip PERCENT]
              [--pct-anyevent PERCENT] [--pct-pinchzoom PERCENT]
              [--pkg-blacklist-file PACKAGE_BLACKLIST_FILE]
              [--pkg-whitelist-file PACKAGE_WHITELIST_FILE]
              [--wait-dbg] [--dbg-no-events]
              [--setup scriptfile] [-f scriptfile [-f scriptfile] ...]
              [--port port]
              [-s SEED] [-v [-v] ...]
              [--throttle MILLISEC] [--randomize-throttle]
              [--profile-wait MILLISEC]
              [--device-sleep-time MILLISEC]
              [--randomize-script]
              [--script-log]
              [--bugreport]
              [--periodic-bugreport]
              COUNT
================================================================

[ Wi-Fi ] : set Tx power of wireless card

Ubuntu 12.04 test OK!

===========================
example :

set Tx-Power in dBm :
iw dev wlan0 set txpower fixed 0
iw dev wlan0 set txpower fixed 30

restore to default:
iw dev wlan0 set txpower auto

===========================

also to test this (work too):

iwconfig:

iwconfig wlan0 txpower 0

iwconfig wlan0 txpower 17

[ Ubuntu ] : login as root

for ubuntu 14.04

1. set password of root :

# sudo passwd root

2. add a line to file:

# sudo gedit /usr/share/lightdm/lightdm.conf.d/50-unity-greeter.conf
add to last line:

greeter-show-manual-login=true

3. restart

============================

for ubuntu 10.04
1. set password of root :
 
# sudo passwd root

2. restart

============================

for ubuntu 12.04
1. vim /etc/lightdm/lightd.conf
2. add to last line
    "greeter-show-manual-login=true"

[ Android ] : save an array to SharedPreferences

save array to SharedPreferences :

public boolean saveArray(String[] array, String arrayName, Context mContext) {  

    SharedPreferences prefs = mContext.getSharedPreferences("preferencename", 0); 

    SharedPreferences.Editor editor = prefs.edit(); 

    editor.putInt(arrayName +"_size", array.length); 

    for(int i=0;i<array.length;i++) 

        editor.putString(arrayName + "_" + i, array[i]); 

    return editor.commit(); 

}

load array from SharedPreferences :

public String[] loadArray(String arrayName, Context mContext) { 

    SharedPreferences prefs = mContext.getSharedPreferences("preferencename", 0); 

    int size = prefs.getInt(arrayName + "_size", 0); 

    String array[] = new String[size]; 

    for(int i=0;i<size;i++) 

        array[i] = prefs.getString(arrayName + "_" + i, null); 

    return array; 

}  

[ Java ] : Read text file to string

source code :

    public String readFileAsString(String filePath) throws java.io.IOException

    {

        BufferedReader reader = new BufferedReader(new FileReader(filePath));

        String line, results = "";

        while( ( line = reader.readLine() ) != null)

        {

            results += line;

        }

        reader.close();

        return results;

    }

[ Android ] : Static Way to get Context

public class MyApplication extends Application{

    private static Context context;

    public void onCreate(){

        super.onCreate();

        MyApplication.context = getApplicationContext();

    }

    public static Context getAppContext() {

        return MyApplication.context;

    }

}

then just call  MyApplication.getAppContext(); to get context