Programs & Examples On #Run war

Launching Spring application Address already in use

This only worked for me by setting additional properties and using available arbitrary port numbers, like this:

  • YML


  port: 18181
  port: 9191
  jvmroute: 5478
    port: 4512
    redirectPort: 1236
  • Properties



Convert date time string to epoch in Bash

What you're looking for is date --date='06/12/2012 07:21:22' +"%s". Keep in mind that this assumes you're using GNU coreutils, as both --date and the %s format string are GNU extensions. POSIX doesn't specify either of those, so there is no portable way of making such conversion even on POSIX compliant systems.

Consult the appropriate manual page for other versions of date.

Note: bash --date and -d option expects the date in US or ISO8601 format, i.e. mm/dd/yyyy or yyyy-mm-dd, not in UK, EU, or any other format.

PHP code to convert a MySQL query to CSV

SELECT * INTO OUTFILE "c:/mydata.csv"
FROM my_table;

(the documentation for this is here:


$select = "SELECT * FROM table_name";

$export = mysql_query ( $select ) or die ( "Sql error : " . mysql_error( ) );

$fields = mysql_num_fields ( $export );

for ( $i = 0; $i < $fields; $i++ )
    $header .= mysql_field_name( $export , $i ) . "\t";

while( $row = mysql_fetch_row( $export ) )
    $line = '';
    foreach( $row as $value )
        if ( ( !isset( $value ) ) || ( $value == "" ) )
            $value = "\t";
            $value = str_replace( '"' , '""' , $value );
            $value = '"' . $value . '"' . "\t";
        $line .= $value;
    $data .= trim( $line ) . "\n";
$data = str_replace( "\r" , "" , $data );

if ( $data == "" )
    $data = "\n(0) Records Found!\n";                        

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=your_desired_name.xls");
header("Pragma: no-cache");
header("Expires: 0");
print "$header\n$data";

No 'Access-Control-Allow-Origin' header is present on the requested resource—when trying to get data from a REST API

adding mode:no-cors can avoid cors issue in the api.

fetch(sign_in, {
        mode: 'no-cors',
        credentials: 'include',
        method: 'POST',
        headers: headers
    .then(response => response.json())
    .then(json => console.log(json))
    .catch(error => console.log('Authorization failed : ' + error.message));

Sending email with gmail smtp with codeigniter email library

Change it to the following:

$ci = get_instance();
$config['protocol'] = "smtp";
$config['smtp_host'] = "ssl://";
$config['smtp_port'] = "465";
$config['smtp_user'] = "[email protected]"; 
$config['smtp_pass'] = "yourpassword";
$config['charset'] = "utf-8";
$config['mailtype'] = "html";
$config['newline'] = "\r\n";


$ci->email->from('[email protected]', 'Blabla');
$list = array('[email protected]');
$this->email->reply_to('[email protected]', 'Explendid Videos');
$ci->email->subject('This is an email test');
$ci->email->message('It is working. Great!');

How do I run a Python script from C#?

The reason it isn't working is because you have UseShellExecute = false.

If you don't use the shell, you will have to supply the complete path to the python executable as FileName, and build the Arguments string to supply both your script and the file you want to read.

Also note, that you can't RedirectStandardOutput unless UseShellExecute = false.

I'm not quite sure how the argument string should be formatted for python, but you will need something like this:

private void run_cmd(string cmd, string args)
     ProcessStartInfo start = new ProcessStartInfo();
     start.FileName = "my/full/path/to/python.exe";
     start.Arguments = string.Format("{0} {1}", cmd, args);
     start.UseShellExecute = false;
     start.RedirectStandardOutput = true;
     using(Process process = Process.Start(start))
         using(StreamReader reader = process.StandardOutput)
             string result = reader.ReadToEnd();

Datetime BETWEEN statement not working in SQL Server

Does the second query return any results from the 17th, or just from the 18th?

The first query will only return results from the 17th, or midnight on the 18th.

Try this instead

select * 
from LOGS 
where check_in >= CONVERT(datetime,'2013-10-17') 
and check_in< CONVERT(datetime,'2013-10-19')

Android TabLayout Android Design

I am facing some issue with menu change when fragment changes in ViewPager. I ended up implemented below code.


public class DashboardFragment extends BaseFragment {

    private Context mContext;
    private TabLayout mTabLayout;
    private ViewPager mViewPager;
    private DashboardPagerAdapter mAdapter;
    private OnModuleChangeListener onModuleChangeListener;
    private NavDashBoardActivity activityInstance;

    public void setOnModuleChangeListener(OnModuleChangeListener onModuleChangeListener) {
        this.onModuleChangeListener = onModuleChangeListener;

    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.dashboard_fragment, container, false);

    //pass -1 if you want to get it via pager
    public Fragment getFragmentFromViewpager(int position) {
        if (position == -1)
            position = mViewPager.getCurrentItem();
        return ((Fragment) (mAdapter.instantiateItem(mViewPager, position)));

    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        mContext = getActivity();

        activityInstance = (NavDashBoardActivity) getActivity();

        mTabLayout = (TabLayout) view.findViewById(;
        mViewPager = (ViewPager) view.findViewById(;

        final List<EnumUtils.Module> moduleToShow = getModuleToShowList();

        for(EnumUtils.Module module :moduleToShow)

        updateTabPagerAndMenu(0 , moduleToShow);

        mAdapter = new DashboardPagerAdapter(getFragmentManager(),moduleToShow);


        mTabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            public void onTabSelected(final TabLayout.Tab tab) {
           Runnable() {
                    public void run() {

            public void onTabUnselected(TabLayout.Tab tab) {

            public void onTabReselected(TabLayout.Tab tab) {

        mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                //added to redraw menu on scroll

            public void onPageSelected(int position) {
                updateTabPagerAndMenu(position , moduleToShow);

            public void onPageScrollStateChanged(int state) {

    //also validate other checks and this method should be in SharedPrefs...
    public static List<EnumUtils.Module> getModuleToShowList(){
        List<EnumUtils.Module> moduleToShow = new ArrayList<>();


        return moduleToShow;

    public void setCurrentTab(final int position){
        if(mViewPager != null){
            mViewPager.postDelayed(new Runnable() {
                public void run() {

    private Fragment getCurrentFragment(){
        return mAdapter.getCurrentFragment();

    private void updateTabPagerAndMenu(int position , List<EnumUtils.Module> moduleToShow){
        //it helps to change menu on scroll
        //No effect after changing below statement
        if(mTabLayout != null)

        if(onModuleChangeListener != null){

            if(activityInstance != null){

                    , EnumUtils.Module.getModuleColor(moduleToShow.get(position)));


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""

    <!-- our tablayout to display tabs  -->
        app:tabTextColor="@android:color/black" />

    <!-- View pager to swipe views -->
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />



public class DashboardPagerAdapter extends FragmentPagerAdapter {

private List<EnumUtils.Module> moduleList;
private Fragment mCurrentFragment = null;

public DashboardPagerAdapter(FragmentManager fm, List<EnumUtils.Module> moduleList){
    this.moduleList = moduleList;

public Fragment getItem(int position) {
    return EnumUtils.Module.getDashboardFragment(moduleList.get(position));

public int getCount() {
    return moduleList.size();

public void setPrimaryItem(ViewGroup container, int position, Object object) {
    if (getCurrentFragment() != object) {
        mCurrentFragment = ((Fragment) object);
    super.setPrimaryItem(container, position, object);

public Fragment getCurrentFragment() {
    return mCurrentFragment;

public int getModulePosition(EnumUtils.Module moduleName){
    for(int x = 0 ; x < moduleList.size() ; x++){
            return x;
    return -1;


And in each page of Fragment setHasOptionMenu(true) in onCreate and implement onCreateOptionMenu. then it will work properly.


public class NavDashBoardActivity extends BaseActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    private Context mContext;
    private DashboardFragment dashboardFragment;
    private Toolbar mToolbar;
    private DrawerLayout drawer;
    private ActionBarDrawerToggle toggle;

    protected void onCreate(Bundle savedInstanceState) {

        mContext = NavDashBoardActivity.this;

        mToolbar = (Toolbar) findViewById(;

        updateToolbarText(new ToolbarTextBO("NCompass " ,""));

        drawer = (DrawerLayout) findViewById(;
        toggle = new ActionBarDrawerToggle(
                this, drawer, mToolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);

        //onclick of back button on Navigation it will popUp fragment...
        toggle.setToolbarNavigationClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                if(!toggle.isDrawerIndicatorEnabled()) {

        final NavigationView navigationView = (NavigationView) findViewById(;
        navigationView.setItemIconTintList(null);//It helps to show icon on Navigation


        //Left Drawer Upper Section
        View headerLayout = navigationView.getHeaderView(0); // 0-index header

        TextView userNameTv = (TextView) headerLayout.findViewById(;
        RoundedImageView ivUserPic = (RoundedImageView) headerLayout.findViewById(;


        headerLayout.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                //close drawer and add a fragment to it
                drawer.closeDrawers();//also try other methods..

        //ZA code starts...
        dashboardFragment = new DashboardFragment();
        dashboardFragment.setOnModuleChangeListener(new OnModuleChangeListener() {
            public void onModuleChanged(EnumUtils.Module module) {
                if(mToolbar != null){

                    if(EnumUtils.Module.getMenuID(module) != -1)


    public void updateStatusBarColor(int colorResourceID){

    private void updateNavigationMenuItem(NavigationView navigationView){
        List<EnumUtils.Module> modules =  DashboardFragment.getModuleToShowList();


    private void backStackListener(){
        getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
            public void onBackStackChanged() {

                if(getSupportFragmentManager().getBackStackEntryCount() >= 1)
                    toggle.setDrawerIndicatorEnabled(false); //disable "hamburger to arrow" drawable
                    toggle.setHomeAsUpIndicator(R.drawable.ic_arrow_back_black_24dp); //set your own
                    ///toggle.setDrawerIndicatorEnabled(false); // this will hide hamburger image
                    ///Toast.makeText(mContext,"Update to Arrow",Toast.LENGTH_SHORT).show();
                if(getSupportFragmentManager().getBackStackEntryCount() >0){
                    if(getCurrentFragment() instanceof DashboardFragment){
                        Fragment subFragment = ((DashboardFragment) getCurrentFragment())


    private void updateToolBarTitle(String title){
    public void updateToolBarColor(String hexColor){
        if(mToolbar != null)

    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(;
        if (drawer.isDrawerOpen(GravityCompat.START)) {
        } else {

    public boolean onCreateOptionsMenu(Menu menu) {
        if (drawer.isDrawerOpen(GravityCompat.START))
            getMenuInflater().inflate(, menu);

        return super.onCreateOptionsMenu(menu);//true is wriiten first..

    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id ==
            if (drawer.isDrawerOpen(GravityCompat.START))
            else {
                if (getSupportFragmentManager().getBackStackEntryCount() > 0) {

                } else

            return false;///true;

        return false;// false so that fragment can also handle the menu event. Otherwise it is handled their
        ///return super.onOptionsItemSelected(item);

    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == {
            // Handle the camera action
        }else if  (id ==  {

        DrawerLayout drawer = (DrawerLayout) findViewById(;
        return true;

    public void updateToolbarText(ToolbarTextBO toolbarTextBO){
        if(toolbarTextBO.getTitle() != null && !toolbarTextBO.getTitle().isEmpty())
        if(toolbarTextBO.getDescription() != null && !toolbarTextBO.getDescription().isEmpty())


    public void onPostCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
        super.onPostCreate(savedInstanceState, persistentState);
        // Sync the toggle state after onRestoreInstanceState has occurred.

    public void onConfigurationChanged(Configuration newConfig) {

Favicon dimensions?

Wikipedia has this to say:

Additionally, such icon files can be either 16×16 or 32×32 pixels in size, and either 8-bit or 24-bit in color depth (note that GIF files have a limited, 256 color palette entries).

I think the best way is to use a 32x32 gif and test it with different browsers.

Split Strings into words with multiple word boundary delimiters

A case where regular expressions are justified:

import re
DATA = "Hey, you - what are you doing here!?"
print re.findall(r"[\w']+", DATA)
# Prints ['Hey', 'you', 'what', 'are', 'you', 'doing', 'here']

How to install a plugin in Jenkins manually

In my case, I needed to install a plugin to an offline build server that's running a Windows Server (version won't matter here). I already installed Jenkins on my laptop to test out changes in advance and it is running on localhost:8080 as a windows service.

So if you are willing to take the time to setup Jenkins on a machine with Internet connection and carry these changes to the offline server Jenkins (it works, confirmed by me!), these are steps you could follow:

  • Jenkins on my laptop: Open up Jenkins, http://localhost:8080
  • Navigator: Manage Jenkins | Download plugin without install option
  • Windows Explorer: Copy the downloaded plugin file that is located at "c:\program files (x86)\Jenkins\plugins" folder (i.e. role-strategy.jpi)
  • Paste it into a shared folder in the offline server
  • Stop the Jenkins Service (Offline Server Jenkins) through Component Services, Jenkins Service
  • Copy the plugin file (i.e. role-strategy.jpi) into "c:\program files (x86)\Jenkins\plugins" folder on the (Offline Jenkins) server
  • Restart Jenkins and voila! It should be installed.

IOS: verify if a point is inside a rect

I'm starting to learn how to code with Swift and was trying to solve this too, this is what I came up with on Swift's playground:

// Code
var x = 1
var y = 2
var lowX = 1
var lowY = 1
var highX = 3
var highY = 3

if (x, y) >= (lowX, lowY) && (x, y) <= (highX, highY ) {
} else {
    print("not inside")

It prints inside

Difference between Node object and Element object?

Node is used to represent tags in general. Divided to 3 types:

Attribute Note: is node which inside its has attributes. Exp: <p id=”123”></p>

Text Node: is node which between the opening and closing its have contian text content. Exp: <p>Hello</p>

Element Node : is node which inside its has other tags. Exp: <p><b></b></p>

Each node may be types simultaneously, not necessarily only of a single type.

Element is simply a element node.

Why can't I center with margin: 0 auto?

Why not?

#header {
    text-align: center;

#header ul {
    display: inline;

Hide div element when screen size is smaller than a specific size

@media only screen and (max-width: 1026px) { 
  #fadeshow1 { 
    display: none; 

Any time the screen is less than 1026 pixels wide, anything inside the { } will apply.

Some browsers don't support media queries. You can get round this using a javascript library like Respond.JS

How can I convert bigint (UNIX timestamp) to datetime in SQL Server?

If anyone getting below error:

Arithmetic overflow error converting expression to data type int

due to unix timestamp is in bigint (instead of int), you can use this:

SELECT DATEADD(S, CONVERT(int,LEFT(1462924862735870900, 10)), '1970-01-01')

Replace the hardcoded timestamp for your actual column with unix-timestamp

Source: MSSQL bigint Unix Timestamp to Datetime with milliseconds

CSV with comma or semicolon?

Well to just to have some saying about semicolon. In lot of country, comma is what use for decimal not period. Mostly EU colonies, which consist of half of the world, another half follow UK standard (how the hell UK so big O_O) so in turn make using comma for database that include number create much of the headache because Excel refuse to recognize it as delimiter.

Like wise in my country, Viet Nam, follow France's standard, our partner HongKong use UK standard so comma make CSV unusable, and we use \t or ; instead for international use, but it still not "standard" per the document of CSV.

PHP Checking if the current date is before or after a set date

I have used this one and it served the purpose:

if($date < date("Y-m-d") ) {
                echo "Date is in the past";}


Bootstrap 3 - set height of modal window according to screen size

Pure CSS solution, using calc

.modal-body {
    max-height: calc(100vh - 200px);
    overflow-y: auto;

200px may be adjusted in accordance to height of header & footer

How to set the default value of an attribute on a Laravel model

You can set Default attribute in Model also>

protected $attributes = [
        'status' => self::STATUS_UNCONFIRMED,
        'role_id' => self::ROLE_PUBLISHER,

You can find the details in these links

1.) How to set a default attribute value for a Laravel / Eloquent model?


You can also Use Accessors & Mutators for this You can find the details in the Laravel documentation 1.)


3.) Universal accessors and mutators in Laravel 4

Error: ANDROID_HOME is not set and "android" command not in your PATH. You must fulfill at least one of these conditions.

Android path set in linux:

$export ANDROID_HOME=/usr/lib/android-sdk-linux
$export PATH=$PATH:$ANDROID_HOME/tools
$export PATH=$PATH:$ANDROID_HOME/platforms-tools


$cordova run android

How do I get an Excel range using row and column numbers in VSTO / C#?

The given answer will throw an error if used in Microsoft Excel 14.0 Object Library. Object does not contain a definition for get_range. Instead use

int countRows = xlWorkSheetData.UsedRange.Rows.Count;
int countColumns = xlWorkSheetData.UsedRange.Columns.Count;
object[,] data = xlWorkSheetData.Range[xlWorkSheetData.Cells[1, 1], xlWorkSheetData.Cells[countRows, countColumns]].Cells.Value2;

How to round up a number in Javascript?

Very near to TheEye answer, but I change a little thing to make it work:

var num = 192.16;_x000D_
console.log(    Math.ceil(num * 10) / 10    );

Set width to match constraints in ConstraintLayout

I found one more answer when there is a constraint layout inside the scroll view then we need to put


to the scroll view



in the constraint layout


<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android=""


// Rest of the views



Asynchronous file upload (AJAX file upload) using jsp and javascript

I don't believe AJAX can handle file uploads but this can be achieved with libraries that leverage flash. Another advantage of the flash implementation is the ability to do multiple files at once (like gmail).

SWFUpload is a good start :

jQuery and some of the other libraries have plugins that leverage SWFUpload. On my last project we used SWFUpload and Java without a problem.

Also helpful and worth looking into is Apache's FileUpload :

HTML5 <video> element on Android

This might not exactly answer your question, but we're using the 3GP or 3GP2 file format. Better even to use the rtsp protocol, but the Android browser will also recognize the 3GP file format.

You can use something like

self.location = URL_OF_YOUR_3GP_FILE

to trigger the video player. The file will be streamed and after playback ends, handling is returned to the browser.

For me this solves a lot of problems with current video tag implementation on android devices.

A method to reverse effect of java String.split()?

For Android: in android.text.TextUtils there are methods:

public static String join (CharSequence delimiter, Iterable tokens)
public static String join (CharSequence delimiter, Object[] tokens)

Returns a string containing the tokens joined by delimiters.

tokens -- an array objects to be joined. Strings will be formed from the objects by calling object.toString().

How do I resolve a path relative to an ASP.NET MVC 4 application root?

To get the absolute path use this:

String path = HttpContext.Current.Server.MapPath("~/Data/data.html");


To get the Controller's Context remove .Current from the above line. By using HttpContext by itself it's easier to Test because it's based on the Controller's Context therefore more localized.

I realize now that I dislike how Server.MapPath works (internally eventually calls HostingEnvironment.MapPath) So I now recommend to always use HostingEnvironment.MapPath because its static and not dependent on the context unless of course you want that...

MVC ajax post to controller action method

It's due to you sending one object, and you're expecting two parameters.

Try this and you'll see:

public class UserDetails
   public string username { get; set; }
   public string password { get; set; }

public JsonResult Login(UserDetails data)
   string error = "";
   //the rest of your code

Twitter bootstrap scrollable modal

/* Important part */
    overflow-y: initial !important
    max-height: calc(100vh - 200px);
    overflow-y: auto;

This works for Bootstrap 3 without JS code and is responsive.


Visual Studio Code always asking for git credentials

In case you are on Windows PC Then answer you are looking for!
Install Git for Windows

That's it!

What does the "+=" operator do in Java?

  • x += y is x = x + y
  • x -= y is x = x - y
  • x *= y is x = x * y
  • x /= y is x = x / y
  • x %= y is x = x % y
  • x ^= y is x = x ^ y
  • x &= y is x = x & y
  • x |= y is x = x | y

and so on ...

Oracle SQL convert date format from DD-Mon-YY to YYYYMM

As offer_date is an number, and is of lower accuracy than your real dates, this may work...
- Convert your real date to a string of format YYYYMM
- Conver that value to an INT
- Compare the result you your offer_date

    offer_date = (SELECT CAST(to_char(create_date, 'YYYYMM') AS INT) FROM customers where id = '12345678')
AND offer_rate > 0 

Also, by doing all the manipulation on the create_date you only do the processing on one value.

Additionally, had you manipulated the offer_date you would not be able to utilise any index on that field, and so force SCANs instead of SEEKs.

How to split CSV files as per number of rows specified?

Use the Linux split command:

split -l 20 file.txt new    

Split the file "file.txt" into files beginning with the name "new" each containing 20 lines of text each.

Type man split at the Unix prompt for more information. However you will have to first remove the header from file.txt (using the tail command, for example) and then add it back on to each of the split files.

Circle-Rectangle collision detection (intersection)

Assuming you have the four edges of the rectangle check the distance from the edges to the center of the circle, if its less then the radius, then the shapes are intersecting.

if sqrt((rectangleRight.x - circleCenter.x)^2 +
        (rectangleBottom.y - circleCenter.y)^2) < radius
// then they intersect

if sqrt((rectangleRight.x - circleCenter.x)^2 +
        (rectangleTop.y - circleCenter.y)^2) < radius
// then they intersect

if sqrt((rectangleLeft.x - circleCenter.x)^2 +
        (rectangleTop.y - circleCenter.y)^2) < radius
// then they intersect

if sqrt((rectangleLeft.x - circleCenter.x)^2 +
        (rectangleBottom.y - circleCenter.y)^2) < radius
// then they intersect

How can I generate a list or array of sequential integers in Java?

This is the shortest I could find.

List version

public List<Integer> makeSequence(int begin, int end)
    List<Integer> ret = new ArrayList<Integer>(++end - begin);

    for (; begin < end; )

    return ret;

Array Version

public int[] makeSequence(int begin, int end)
    if(end < begin)
        return null;

    int[] ret = new int[++end - begin];
    for (int i=0; begin < end; )
        ret[i++] = begin++;
    return ret;

How to compress a String in Java?

When you create a String, you can think of it as a list of char's, this means that for each character in your String, you need to support all the possible values of char. From the sun docs

char: The char data type is a single 16-bit Unicode character. It has a minimum value of '\u0000' (or 0) and a maximum value of '\uffff' (or 65,535 inclusive).

If you have a reduced set of characters you want to support you can write a simple compression algorithm, which is analogous to binary->decimal->hex radix converstion. You go from 65,536 (or however many characters your target system supports) to 26 (alphabetical) / 36 (alphanumeric) etc.

I've used this trick a few times, for example encoding timestamps as text (target 36 +, source 10) - just make sure you have plenty of unit tests!

Generate random int value from 3 to 6

Nice and simple, from Pinal Dave's site:

SET @Lower = 3 ---- The lowest random number
SET @Upper = 7 ---- One more than the highest random number
SELECT @Random = ROUND(((@Upper - @Lower -1) * RAND() + @Lower), 0)
SELECT @Random

(I did make a slight change to the @Upper- to include the upper number, added 1.)

PySpark: multiple conditions in when clause

It should be:

$when(((tdata.Age == "" ) & (tdata.Survived == "0")), mean_age_0)

Why doesn't list have safe "get" method like dictionary?

A reasonable thing you can do is to convert the list into a dict and then access it with the get method:

>>> my_list = ['a', 'b', 'c', 'd', 'e']
>>> my_dict = dict(enumerate(my_list))
>>> print my_dict
{0: 'a', 1: 'b', 2: 'c', 3: 'd', 4: 'e'}
>>> my_dict.get(2)
>>> my_dict.get(10, 'N/A')

Redirect pages in JSP?

    String redirectURL = "";

Could not complete the operation due to error 80020101. IE

wrap your entire code block in this:


//code here


also make sure to specify the type of script to be text/javascript

try that and let me know how it goes

Get timezone from users browser using moment(timezone).js

Using Moment library, see their website ->

i notice they also user their own library in their website, so you can have a try using the browser console before installing it


The moment#tz mutator will change the time zone and update the offset.

moment("2013-11-18").tz("America/Toronto").format('Z'); // -05:00
moment("2013-11-18").tz("Europe/Berlin").format('Z');   // +01:00

This information is used consistently in other operations, like calculating the start of the day.

var m ="2013-11-18 11:55", "America/Toronto");
m.format();                     // 2013-11-18T11:55:00-05:00
m.startOf("day").format();      // 2013-11-18T00:00:00-05:00"Europe/Berlin").format(); // 2013-11-18T06:00:00+01:00
m.startOf("day").format();      // 2013-11-18T00:00:00+01:00

Without an argument, moment#tz returns:

    the time zone name assigned to the moment instance or
    undefined if a time zone has not been set.

var m ="2013-11-18 11:55", "America/Toronto");;  // America/Toronto
var m ="2013-11-18 11:55"); === undefined;  // true

Python JSON encoding

Python lists translate to JSON arrays. What it is giving you is a perfectly valid JSON string that could be used in a Javascript application. To get what you expected, you would need to use a dict:

>>> json.dumps({'apple': 'cat', 'banana':'dog', 'pear':'fish'})
'{"pear": "fish", "apple": "cat", "banana": "dog"}'

Auto-indent in Notepad++

Notepad++ will only auto-insert subsequent indents if you manually indent the first line in a block; otherwise you can re-indent your code after the fact using TextFX > TextFX Edit > Reindent C++ code.

How to check a radio button with jQuery?

Try this

var isChecked = $("#radio_1")[0].checked;

Error in setting JAVA_HOME

JAVA_HOME should point to jdk directory and not to jre directory. Also JAVA_HOME should point to the home jdk directory and not to jdk/bin directory.

Assuming that you have JDK installed in your program files directory then you need to set the JAVA_HOME like this:

JAVA_HOME="C:\Program Files\Java\jdkxxx"

xxx is the jdk version

Follow this link to learn more about setting JAVA_HOME:

How do I create a pause/wait function using Qt?

If you want a cross-platform method of doing this, the general pattern is to derive from QThread and create a function (static, if you'd like) in your derived class that will call one of the sleep functions in QThread.

Pivoting rows into columns dynamically in Oracle

Happen to have a task on pivot. Below works for me as tested just now on 11g:

select * from
    'Canada', 'USA', 'Mexico'

How to find out the server IP address (using JavaScript) that the browser is connected to?

I believe John's answer is correct. For instance, I'm using my laptop through a wifi service run by a conference centre -- I'm pretty sure that there is no way for javascript running within my browser to discover the IP address being used by the service provider. On the other hand, it may be possible to address a suitable external resource from javascript. You can write your own if your own by making an ajax call to a server which can take the IP address from the HTTP headers and return it, or try googling "find my ip". The cleanest solution is probably to capture the information before the page is served and insert it in the html returned to the user. See How to get a viewer's IP address with python? for info on how to capture the information if you are serving the page with python.

How to use JavaScript to change the form action

If you're using jQuery, it's as simple as this:

$('form').attr('action', 'myNewActionTarget.html');

IE11 prevents ActiveX from running

There is no solution to this problem. As of IE11 on Windows 8, Microsoft no longer allows ActiveX plugins to run in its browser space. There is absolutely nothing that a third party developer can do about it.

A similar thing has recently happened with the Chrome browser which no longer supports NPAPI plugins. Instead Chrome only supports PPAPI plugins which are useless for system level tasks once performed by NPAPI plugins.

So developers needing browser support for system interactive plugins can only recommend either the Firefox browser or the ASPS web browser.

Paste in insert mode?

If you set Vim to use the system clipboard (:set clipboard=unnamed), then any text you copy in Vim can be pasted using Shift + Insert. Shift + Insert is simply an OS-wide paste key-combination (Ctrl + Insert is the corresponding 'copy').

Round button with text and icon in flutter

You can do something like,

RaisedButton.icon( elevation: 4.0,
                    icon: Image.asset('images/image_upload.png' ,width: 20,height: 20,) ,
                      color: Theme.of(context).primaryColor,
                    onPressed: getImage,
                    label: Text("Add Team Image",style: TextStyle(
                        color: Colors.white, fontSize: 16.0))

How can I select from list of values in SQL Server

I create a function on most SQL DB I work on to do just this.

CREATE OR ALTER FUNCTION [dbo].[UTIL_SplitList](@parList Varchar(MAX),@splitChar Varchar(1)=',') 
  Returns @t table (Column_Value varchar(MAX))
    Declare @pos integer 
    set @pos = CharIndex(@splitChar, @parList)
    while @pos > 0
      Insert Into @t (Column_Value) VALUES (Left(@parList, @pos-1))
      set @parList = Right(@parList, Len(@parList) - @pos)
      set @pos = CharIndex(@splitChar, @parList)
    Insert Into @t (Column_Value) VALUES (@parList)

Once the function exists, it is as easy as


Regex: match everything but specific pattern

Regex: match everything but:

Demo note: the newline \n is used inside negated character classes in demos to avoid match overflow to the neighboring line(s). They are not necessary when testing individual strings.

Anchor note: In many languages, use \A to define the unambiguous start of string, and \z (in Python, it is \Z, in JavaScript, $ is OK) to define the very end of the string.

Dot note: In many flavors (but not POSIX, TRE, TCL), . matches any char but a newline char. Make sure you use a corresponding DOTALL modifier (/s in PCRE/Boost/.NET/Python/Java and /m in Ruby) for the . to match any char including a newline.

Backslash note: In languages where you have to declare patterns with C strings allowing escape sequences (like \n for a newline), you need to double the backslashes escaping special characters so that the engine could treat them as literal characters (e.g. in Java, world\. will be declared as "world\\.", or use a character class: "world[.]"). Use raw string literals (Python r'\bworld\b'), C# verbatim string literals @"world\.", or slashy strings/regex literal notations like /world\./.

Oracle DB : java.sql.SQLException: Closed Connection

It means the connection was successfully established at some point, but when you tried to commit right there, the connection was no longer open. The parameters you mentioned sound like connection pool settings. If so, they're unrelated to this problem. The most likely cause is a firewall between you and the database that is killing connections after a certain amount of idle time. The most common fix is to make your connection pool run a validation query when a connection is checked out from it. This will immediately identify and evict dead connnections, ensuring that you only get good connections out of the pool.

Finding whether a point lies inside a rectangle or not

bool pointInRectangle(Point A, Point B, Point C, Point D, Point m ) {
    Point AB = vect2d(A, B);  float C1 = -1 * (AB.y*A.x + AB.x*A.y); float  D1 = (AB.y*m.x + AB.x*m.y) + C1;
    Point AD = vect2d(A, D);  float C2 = -1 * (AD.y*A.x + AD.x*A.y); float D2 = (AD.y*m.x + AD.x*m.y) + C2;
    Point BC = vect2d(B, C);  float C3 = -1 * (BC.y*B.x + BC.x*B.y); float D3 = (BC.y*m.x + BC.x*m.y) + C3;
    Point CD = vect2d(C, D);  float C4 = -1 * (CD.y*C.x + CD.x*C.y); float D4 = (CD.y*m.x + CD.x*m.y) + C4;
    return     0 >= D1 && 0 >= D4 && 0 <= D2 && 0 >= D3;}

Point vect2d(Point p1, Point p2) {
    Point temp;
    temp.x = (p2.x - p1.x);
    temp.y = -1 * (p2.y - p1.y);
    return temp;}

Points inside polygon

I just implemented AnT's Answer using c++. I used this code to check whether the pixel's coordination(X,Y) lies inside the shape or not.

How to draw a circle with text in the middle?

For a web design I was recently given I had to solve the centered and unknown amount of text in a fixed circle issue and I thought I'd share the solution here for other people looking into circle/text combos.

The main issue I had was text would often break the bounds of the circle. To solve this I ended up using 4 divs. One rectangular container that specified the max (fixed) boundaries of the circle. Inside that would be the div that draws the circle with its width and height set to 100% so changing the size of the parent changes the size of the actual circle. Inside that would be another rectangular div which, using %'s, would create a text boundary area preventing any text leaving the circle (for the most part) Then finally the actual div for the text and vertical centering.

It makes more sense as code:

/* Main Container -  this controls the size of the circle */_x000D_
 width : 128px;_x000D_
 height : 128px;_x000D_
 margin : 0;_x000D_
 padding : 0;_x000D_
/* border : 1px solid red; */_x000D_
/* Circle Main draws the actual circle */_x000D_
 width : 100%;_x000D_
 height : 100%;_x000D_
 border-radius : 50%;_x000D_
 border : 2px solid black; /* can alter thickness and colour of circle on this line */_x000D_
 margin : 0;_x000D_
 padding : 0;_x000D_
/* Circle Text Container - constrains text area to within the circle */_x000D_
 /* area constraints */_x000D_
 width : 70%;_x000D_
 height : 70%;_x000D_
 max-width : 70%;_x000D_
 max-height : 70%;_x000D_
 margin : 0;_x000D_
 padding : 0;_x000D_
 /* some position nudging to center the text area */_x000D_
 position : relative;_x000D_
 left : 15%;_x000D_
 top : 15%;_x000D_
 /* preserve 3d prevents blurring sometimes caused by the text centering in the next class */_x000D_
 transform-style : preserve-3d;_x000D_
 /*border : 1px solid green;*/_x000D_
/* Circle Text - the appearance of the text within the circle plus vertical centering */_x000D_
 /* change font/size/etc here */_x000D_
 font: 11px "Tahoma", Arial, Serif; _x000D_
 text-align : center;_x000D_
 /* vertical centering technique */_x000D_
 position : relative;_x000D_
 top : 50%;_x000D_
 transform : translateY(-50%);_x000D_
<div class="circle_container">_x000D_
 <div class="circle_main">_x000D_
  <div class="circle_text_container">_x000D_
   <div class = "circle_text">_x000D_
    Here is an example of some text in my circle._x000D_

You can uncomment the border colours on the container divs to see how it constrains.

Things to be aware of: You can still break the bounds of the circle if you put too much text in or use words/unbroken text that are too long. It's still not a good fit for completely unknown text (such as user input) but works best when you know vaguely what the largest amount of text you'll need to store is and set your circle size and font sizes accordingly. You can set the text container div to hide any overflow of course, but that may just look "broken" and is no replacement for actually accounting for max size properly in your design.

Hope this is useful to someone! HTML/CSS is not my main discipline so I'm sure it can be improved on!

How to convert UTF8 string to byte array?

The TextEncoder and TextDecoder Encoding API will let you both encode and decode UTF-8 easily (using typed arrays):

const encoded = new TextEncoder().encode("Ge?a s?? ??sµe");
const decoded = new TextDecoder().decode(encoded);

console.log(encoded, decoded);

Browser support isn't too bad, and there's a polyfill that should work in IE11 and older versions of Edge.

Older versions of TextEncoder supported other different encodings as a string constructor parameter argument, but since Firefox 48 and Chrome 53 this is no-longer supported and TextEncoder and TextDecoder support only UTF-8.

So this will no-longer work in modern web-browsers used since 2016:

new TextDecoder("shift-jis").decode(new Uint8Array(textbuffer))

'router-outlet' is not a known element

If you are doing unit testing and get this error then Import RouterTestingModule into your app.component.spec.ts or inside your featured components' spec.ts:

import { RouterTestingModule } from '@angular/router/testing';

Add RouterTestingModule into your imports: [] like

describe('AppComponent', () => {

  beforeEach(async(() => {    
      imports: [    
      declarations: [    

Get latest from Git branch

If you have forked a repository fro Delete your forked copy and fork it again from master.

JQuery add class to parent element


vuejs update parent data from child component

In the child

            v-on:input="(event) => this.$emit('phoneNumber',"

    return {
      contact_number : this.contact_number_props
  props : ['contact_number_props']

In parent

<contact-component v-on:phoneNumber="eventPhoneNumber" :contact_number_props="contact_number"></contact-component>

 methods : {
     eventPhoneNumber (value) {
      this.contact_number = value

ToList().ForEach in Linq

As xanatos said, this is a misuse of ForEach.

If you are going to use linq to handle this, I would do it like this:

var departments = employees.SelectMany(x => x.Departments);
foreach (var item in departments)
    item.SomeProperty = null;

However, the Loop approach is more readable and therefore more maintainable.

Docker-compose: node_modules not present in a volume after npm install succeeds

There is also some simple solution without mapping node_module directory into another volume. It's about to move installing npm packages into final CMD command.

Disadvantage of this approach:

  • run npm install each time you run container (switching from npm to yarn might also speed up this process a bit).


FROM node:0.12
WORKDIR /worker
COPY package.json /worker/
COPY . /worker/
CMD /bin/bash -c 'npm install; npm start'


    image: redis
    build: ./worker
        - "9730:9730"
        - worker/:/worker/
        - redis

How to remove ASP.Net MVC Default HTTP Headers?

X-Powered-By is a custom header in IIS. Since IIS 7, you can remove it by adding the following to your web.config:

      <remove name="X-Powered-By" />

This header can also be modified to your needs, for more information refer to

Add this to web.config to get rid of the X-AspNet-Version header:

  <httpRuntime enableVersionHeader="false" />

Finally, to remove X-AspNetMvc-Version, edit Global.asax.cs and add the following in the Application_Start event:

protected void Application_Start()
    MvcHandler.DisableMvcResponseHeader = true;

You can also modify headers at runtime via the Application_PreSendRequestHeaders event in Global.asax.cs. This is useful if your header values are dynamic:

protected void Application_PreSendRequestHeaders(object source, EventArgs e)
      Response.Headers.Add("bar", "quux");

Android: adb pull file on desktop

Use a fully-qualified path to the desktop (e.g., /home/mmurphy/Desktop).

Example: adb pull sdcard/log.txt /home/mmurphy/Desktop

Create two threads, one display odd & other even numbers

package com.example;

public class MyClass  {
    static int mycount=0;
    static Thread t;
    static Thread t2;
    public static void main(String[] arg)
        t2=new Thread(new Runnable() {
            public void run() {
                System.out.print(mycount++ + " even \n");
                try {
                } catch (InterruptedException e) {
        t=new Thread(new Runnable() {
            public void run() {
                System.out.print(mycount++ + " odd \n");
                try {
                } catch (InterruptedException e) {

What's the difference between Docker Compose vs. Dockerfile

"better" is relative. It all depends on what your needs are. Docker compose is for orchestrating multiple containers. If these images already exist in the docker registry, then it's better to list them in the compose file. If these images or some other images have to be built from files on your computer, then you can describe the processes of building those images in a Dockerfile.

I understand that Dockerfiles are used in Docker Compose, but I am not sure if it is good practice to put everything in one large Dockerfile with multiple FROM commands for the different images?

Using multiple FROM in a single dockerfile is not a very good idea because there is a proposal to remove the feature. 13026

If for instance, you want to dockerize an application which uses a database and have the application files on your computer, you can use a compose file together with a dockerfile as follows


  image: mysql:5.7
    - ./db-data:/var/lib/mysql
    - "MYSQL_ROOT_PASSWORD=secret"
    - "MYSQL_DATABASE=homestead"
    - "MYSQL_USER=homestead"
    - "3307:3306"
    context: ./path/to/Dockerfile
    dockerfile: Dockerfile
    - ./:/app
  working_dir: /app


FROM php:7.1-fpm 
RUN apt-get update && apt-get install -y libmcrypt-dev \
  mysql-client libmagickwand-dev --no-install-recommends \
  && pecl install imagick \
  && docker-php-ext-enable imagick \
  && docker-php-ext-install pdo_mysql \
  && curl -sS | php -- --install-dir=/usr/local/bin --filename=composer

How to pass parameters using ui-sref in ui-router to controller

You don't necessarily need to have the parameters inside the URL.

For instance, with:

.state('home', {
  url: '/',
  views: {
    '': {
      templateUrl: 'home.html',
      controller: 'MainRootCtrl'

  params: {
    foo: null,
    bar: null

You will be able to send parameters to the state, using either:

$state.go('home', {foo: true, bar: 1});
// or
<a ui-sref="home({foo: true, bar: 1})">Go!</a>

Of course, if you reload the page once on the home state, you will loose the state parameters, as they are not stored anywhere.

A full description of this behavior is documented here, under the params row in the state(name, stateConfig) section.

Ruby: Can I write multi-line string with no concatenation?

If you do mind extra spaces and newlines, you can use

conn.exec %w{select attr1, attr2, attr3, attr4, attr5, attr6, attr7
  from table1, table2, table3, etc, etc, etc, etc, etc,
  where etc etc etc etc etc etc etc etc etc etc etc etc etc} * ' '

(use %W for interpolated strings)

IsNothing versus Is Nothing

I'm leaning towards the "Is Nothing" alternative, primarily because it seems more OO.

Surely Visual Basic ain't got the Ain't keyword.

How to use document.getElementByName and getElementByTag?

  1. The getElementsByName() method accesses all elements with the specified name. this method returns collection of elements that is an array.
  2. The getElementsByTagName() method accesses all elements with the specified tagname. this method returns collection of elements that is an array.
  3. Accesses the first element with the specified id. this method returns only a single element.


<script type="text/javascript">
    function getElements() {
        var x=document.getElementById("y");
    <input name="x" id="y" type="text" size="20" /><br />

This will return a single HTML element and display the value attribute of it.

<script type="text/javascript">
    function getElements() {
        var x=document.getElementsByName("x");
    <input name="x" id="y" type="text" size="20" /><br />
    <input name="x" id="y" type="text" size="20" /><br />

this will return an array of HTML elements and number of elements that match the name attribute.

Extracted from w3schools.

How to write "Html.BeginForm" in Razor

The following code works fine:

@using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />

and generates as expected:

<form action="/Upload/Upload" enctype="multipart/form-data" method="post">    
        Select a file <input type="file" name="file" />
        <input type="submit" value="Upload" />

On the other hand if you are writing this code inside the context of other server side construct such as an if or foreach you should remove the @ before the using. For example:

@if (SomeCondition)
    using (Html.BeginForm("Upload", "Upload", FormMethod.Post, 
                                      new { enctype = "multipart/form-data" }))
            Select a file <input type="file" name="file" />
            <input type="submit" value="Upload" />

As far as your server side code is concerned, here's how to proceed:

public ActionResult Upload(HttpPostedFileBase file) 
    if (file != null && file.ContentLength > 0) 
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/content/pics"), fileName);
    return RedirectToAction("Upload");

Convert to Datetime MM/dd/yyyy HH:mm:ss in Sql Server


select convert(varchar(10),GETDATE(), 103) + 
       ' '+
       right(convert(varchar(32),GETDATE(),108),8) AS Date_Time

It will Produce:

Date_Time 30/03/2015 11:51:40

Convert char array to a int number in C

It's not what the question asks but I used @Rich Drummond 's answer for a char array read in from stdin which is null terminated.

char *buff;
size_t buff_size = 100;
int choice;
    buff = (char *)malloc(buff_size *sizeof(char));
    getline(&buff, &buff_size, stdin);
    choice = atoi(buff);

Adding rows to tbody of a table using jQuery

("#tblEntAttributes tbody")

needs to be

$("#tblEntAttributes tbody").

You are not selecting the element with the correct syntax

Here's an example of both



$("#tblEntAttributes tbody").append(newRowContent);


In android how to set navigation drawer header image and name programmatically in class file?

In Kotlin

    val hView = nav_view.getHeaderView(0)
    val textViewName = hView.findViewById( as TextView
    val textViewEmail = hView.findViewById( as TextView
    val imgvw = hView.findViewById( as ImageView

Finding length of char array

sizeof returns the size of the type of the variable in bytes. So in your case it's returning the size of your char[7] which is 7 * sizeof(char). Since sizeof(char) = 1, the result is 7.

Expanding this to another example:

int intArr[5];
printf("sizeof(intArr)=%u", sizeof(intArr));

would yield 5 * sizeof(int), so you'd get the result "20" (At least on a regular 32bit platform. On others sizeof(int) might differ)

To return to your problem:

It seems like, that what you want to know is the length of the string which is contained inside your array and not the total array size.

By definition C-Strings have to be terminated with a trailing '\0' (0-Byte). So to get the appropriate length of the string contained within your array, you have to first terminate the string, so that you can tell when it's finished. Otherwise there would be now way to know.

All standard functions build upon this definition, so if you call strlen to retrieve the str ing len gth, it will iterate through the given array until it finds the first 0-byte, which in your case would be the very first element.

Another thing you might need to know that only because you don't fill the remaining elements of your char[7] with a value, they actually do contain random undefined values.

Hope that helped.

What does --net=host option in Docker command really do?

The --net=host option is used to make the programs inside the Docker container look like they are running on the host itself, from the perspective of the network. It allows the container greater network access than it can normally get.

Normally you have to forward ports from the host machine into a container, but when the containers share the host's network, any network activity happens directly on the host machine - just as it would if the program was running locally on the host instead of inside a container.

While this does mean you no longer have to expose ports and map them to container ports, it means you have to edit your Dockerfiles to adjust the ports each container listens on, to avoid conflicts as you can't have two containers operating on the same host port. However, the real reason for this option is for running apps that need network access that is difficult to forward through to a container at the port level.

For example, if you want to run a DHCP server then you need to be able to listen to broadcast traffic on the network, and extract the MAC address from the packet. This information is lost during the port forwarding process, so the only way to run a DHCP server inside Docker is to run the container as --net=host.

Generally speaking, --net=host is only needed when you are running programs with very specific, unusual network needs.

Lastly, from a security perspective, Docker containers can listen on many ports, even though they only advertise (expose) a single port. Normally this is fine as you only forward the single expected port, however if you use --net=host then you'll get all the container's ports listening on the host, even those that aren't listed in the Dockerfile. This means you will need to check the container closely (especially if it's not yours, e.g. an official one provided by a software project) to make sure you don't inadvertently expose extra services on the machine.

Check if an object exists

the boolean value of an empty QuerySet is also False, so you could also just do...

if not user_object:
   do insert or whatever etc.

Create a function with optional call variables

Not sure I understand the question correctly.

From what I gather, you want to be able to assign a value to Domain if it is null and also what to check if $args2 is supplied and according to the value, execute a certain code?

I changed the code to reassemble the assumptions made above.

Function DoStuff($computername, $arg2, $domain)
    if($domain -ne $null)
        $domain = "Domain1"

    if($arg2 -eq $null)

DoStuff -computername "Test" -arg2 "" -domain "Domain2"
DoStuff -computername "Test" -arg2 "Test"  -domain ""
DoStuff -computername "Test" -domain "Domain2"
DoStuff -computername "Test" -arg2 "Domain2"

Did that help?

apache mod_rewrite is not working or not enabled

It's working.

my solution is:

1.create a test.conf into /etc/httpd/conf.d/test.conf

2.wrote some rule, like:

<Directory "/var/www/html/test">
RewriteEngine On
RewriteRule ^link([^/]*).html$ rewrite.php?link=$1 [L]

3.restart your Apache server.

4.try again yourself.

Convert dictionary values into array

If you would like to use linq, so you can try following:

Dictionary<string, object> dict = new Dictionary<string, object>();
var arr = dict.Select(z => z.Value).ToArray();

I don't know which one is faster or better. Both work for me.

How to change background color of cell in table using java script

<table border="1" cellspacing="0" cellpadding= "20">
    <td id="id1" ></td>

Put id for cell and then change background of the cell.

How to import cv2 in python3?

The best way is to create a virtual env. first and then do pip install , everything will work fine

How do I replace all line breaks in a string with <br /> elements?

Regardless of the system:


How can I edit a .jar file?

This is a tool to open Java class file binaries, view their internal structure, modify portions of it if required and save the class file back. It also generates readable reports similar to the javap utility. Easy to use Java Swing GUI. The user interface tries to display as much detail as possible and tries to present a structure as close as the actual Java class file structure. At the same time ease of use and class file consistency while doing modifications is also stressed. For example, when a method is deleted, the associated constant pool entry will also be deleted if it is no longer referenced. In built verifier checks changes before saving the file. This tool has been used by people learning Java class file internals. This tool has also been used to do quick modifications in class files when the source code is not available." this is a quote from the website.

Android OnClickListener - identify a button

Another way of doing it is a single listener from activity , like this:

public class MyActivity extends Activity implements OnClickListener {
    .......  code

    //my listener
    public void onClick(View v) {
        if (v.getId() == { 

        if (v.getId() == { 

I Like to do it with single IF instead of switch-else, but if you prefer that, then you should do:

//my listener
public void onClick(View v) {
    switch(v.getId()) {


When to use: Java 8+ interface default method, vs. abstract method

There's a lot more to abstract classes than default method implementations (such as private state), but as of Java 8, whenever you have the choice of either, you should go with the defender (aka. default) method in the interface.

The constraint on the default method is that it can be implemented only in the terms of calls to other interface methods, with no reference to a particular implementation's state. So the main use case is higher-level and convenience methods.

The good thing about this new feature is that, where before you were forced to use an abstract class for the convenience methods, thus constraining the implementor to single inheritance, now you can have a really clean design with just the interface and a minimum of implementation effort forced on the programmer.

The original motivation to introduce default methods to Java 8 was the desire to extend the Collections Framework interfaces with lambda-oriented methods without breaking any existing implementations. Although this is more relevant to the authors of public libraries, you may find the same feature useful in your project as well. You've got one centralized place where to add new convenience and you don't have to rely on how the rest of the type hierarchy looks.

Undefined reference to pthread_create in Linux

in eclipse

properties->c/c++Build->setting->GCC C++ linker->libraries in top part add "pthread"

Is there a way I can retrieve sa password in sql server 2005


There is a way to retrieve the password by using Brute-Force attack, have a look at the following tool from codeproject Retrieve SQL Server Password

How to use the tool to retrieve the password

To Retrieve the password of SQL Server user,run the following query in SQL Query Analyzer

"Select Password from SysxLogins Where Name = 'XXXX'" Where XXXX is the user

name for which you want to retrieve password.Copy the password field (Hashed Code) and

paste here (in Hashed code Field) and click on start button to retrieve

I checked the tool on SQLServer 2000 and it's working fine.

SQL Query Multiple Columns Using Distinct on One Column Only

You must use an aggregate function on the columns against which you are not grouping. In this example, I arbitrarily picked the Min function. You are combining the rows with the same FruitType value. If I have two rows with the same FruitType value but different Fruit_Id values for example, what should the system do?

Select Min(tblFruit_id) As tblFruit_id
    , tblFruit_FruitType
From tblFruit
Group By tblFruit_FruitType

SQL Fiddle example

HTML for the Pause symbol in audio and video control

I found it, it’s in the Miscellaneous Technical block. ? (U+23F8)

how to log in to mysql and query the database from linux terminal

In Ubuntu, all I have to do ran is sudo mysql in GNOME terminal and that's it. I can start making databases or query a data in table, etc.

Passing command line arguments in Visual Studio 2010?

Visual Studio e.g. 2019 In general be aware that the selected Platform (e.g. x64) in the configuration Dialog is the the same as the Platform You intend to debug with! (see picture for explanation)

Greetings mic enter image description here

How to change a dataframe column from String type to Double type in PySpark?

the solution was simple -

toDoublefunc = UserDefinedFunction(lambda x: float(x),DoubleType())
changedTypedf = joindf.withColumn("label",toDoublefunc(joindf['show']))

How to open URL in Microsoft Edge from the command line?

All the other solutions work for Microsoft Edge (legacy) and on Windows 10 only. As of 2020, it will be discontinued and replaced by Microsoft Edge (Chromium based).

The solution that works with the new Edge on Windows 7, 8 and 10 is :

start msedge URL

Source :

Detecting superfluous #includes in C/C++?

Sorry to (re-)post here, people often don't expand comments.

Check my comment to crashmstr, FlexeLint / PC-Lint will do this for you. Informational message 766. Section 11.8.1 of my manual (version 8.0) discusses this.

Also, and this is important, keep iterating until the message goes away. In other words, after removing unused headers, re-run lint, more header files might have become "unneeded" once you remove some unneeded headers. (That might sound silly, read it slowly & parse it, it makes sense.)

jQuery - What are differences between $(document).ready and $(window).load?

From the jQuery API Document

While JavaScript provides the load event for executing code when a page is rendered, this event does not get triggered until all assets such as images have been completely received. In most cases, the script can be run as soon as the DOM hierarchy has been fully constructed. The handler passed to .ready() is guaranteed to be executed after the DOM is ready, so this is usually the best place to attach all other event handlers and run other jQuery code. When using scripts that rely on the value of CSS style properties, it's important to reference external stylesheets or embed style elements before referencing the scripts.

In cases where code relies on loaded assets (for example, if the dimensions of an image are required), the code should be placed in a handler for the load event instead.

Answer to the second question -

No, they are identical as long as you are not using jQuery in no conflict mode.

SQL set values of one column equal to values of another column in the same table

I don't think that other example is what you're looking for. If you're just updating one column from another column in the same table you should be able to use something like this.

update some_table set null_column = not_null_column where null_column is null

Run cron job only if it isn't already running

I do this for a print spooler program that I wrote, it's just a shell script:

if ps -ef | grep -v grep | grep doctype.php ; then
        exit 0
        /home/user/bin/doctype.php >> /home/user/bin/spooler.log &
        #mailing program
        /home/user/bin/simplemail.php "Print spooler was not running...  Restarted." 
        exit 0

It runs every two minutes and is quite effective. I have it email me with special information if for some reason the process is not running.

How to increase the execution timeout in php?

optional : if you set config about php.ini but still can't upload

-this is php function to check error code

$error_type = [];
$error_type[0] = "There is no error";
$error_type[1] = "The uploaded file exceeds the upload_max_filesize directive in php.ini.";
$error_type[2] = "The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.";
$error_type[3] = "The uploaded file was only partially uploaded.";
$error_type[4] = "No file was uploaded.";
//$error_type["5"] = "";
$error_type[6] = "Missing a temporary folder. Introduced in PHP 5.0.3.";
$error_type[7] = "Failed to write file to disk. Introduced in PHP 5.1.0.";
$error_type[8] = "A PHP extension stopped the file upload. PHP does not provide a way to ascertain which extension caused the file upload to stop; examining the list of loaded extensions with phpinfo() may help. Introduced in PHP 5.2.0.";
//--> show msg error.
$status_code = $_FILES["uploadfile"]["error"];
if($status_code != 0){
    echo $error_type[$status_code];

SOAP vs REST (differences)

REST vs SOAP is not the right question to ask.

REST, unlike SOAP is not a protocol.

REST is an architectural style and a design for network-based software architectures.

REST concepts are referred to as resources. A representation of a resource must be stateless. It is represented via some media type. Some examples of media types include XML, JSON, and RDF. Resources are manipulated by components. Components request and manipulate resources via a standard uniform interface. In the case of HTTP, this interface consists of standard HTTP ops e.g. GET, PUT, POST, DELETE.

@Abdulaziz's question does illuminate the fact that REST and HTTP are often used in tandem. This is primarily due to the simplicity of HTTP and its very natural mapping to RESTful principles.

Fundamental REST Principles

Client-Server Communication

Client-server architectures have a very distinct separation of concerns. All applications built in the RESTful style must also be client-server in principle.


Each client request to the server requires that its state be fully represented. The server must be able to completely understand the client request without using any server context or server session state. It follows that all state must be kept on the client.


Cache constraints may be used, thus enabling response data to be marked as cacheable or not-cacheable. Any data marked as cacheable may be reused as the response to the same subsequent request.

Uniform Interface

All components must interact through a single uniform interface. Because all component interaction occurs via this interface, interaction with different services is very simple. The interface is the same! This also means that implementation changes can be made in isolation. Such changes, will not affect fundamental component interaction because the uniform interface is always unchanged. One disadvantage is that you are stuck with the interface. If an optimization could be provided to a specific service by changing the interface, you are out of luck as REST prohibits this. On the bright side, however, REST is optimized for the web, hence incredible popularity of REST over HTTP!

The above concepts represent defining characteristics of REST and differentiate the REST architecture from other architectures like web services. It is useful to note that a REST service is a web service, but a web service is not necessarily a REST service.

See this blog post on REST Design Principles for more details on REST and the above stated bullets.

EDIT: update content based on comments

How to open the default webbrowser using java

Here is my code. It'll open given url in default browser (cross platform solution).

import java.awt.Desktop;

public class Browser {
    public static void main(String[] args) {
        String url = "";

            Desktop desktop = Desktop.getDesktop();
            try {
                desktop.browse(new URI(url));
            } catch (IOException | URISyntaxException e) {
                // TODO Auto-generated catch block
            Runtime runtime = Runtime.getRuntime();
            try {
                runtime.exec("xdg-open " + url);
            } catch (IOException e) {
                // TODO Auto-generated catch block

How to increase the max connections in postgres?

change max_connections variable in postgresql.conf file located in /var/lib/pgsql/data or /usr/local/pgsql/data/

Offset a background image from the right using CSS

If you have a fixed width element and know the width of your background image, you can simply set the background-position to : the element's width - the image's width - the gap you want on the right.

For example : with a 100px-wide element and a 300px-wide image, to get a gap of 10px on the right, you set it to 100-300-10=-210px :

#myElement {
  background:url(my_image.jpg) no-repeat -210px top;

And you get the rightmost 80 pixels of your image on the left of your element, and a gap of 20px on the right.

I know it can sound stupid but sometimes it saves the time... I use that much in a vertical manner (gap at bottom) for navigation links with text below image.

Not sure it applies to your case though.

Java SSLHandshakeException "no cipher suites in common"

This problem can be caused by undue manipulation of the enabled cipher suites at the client or the server, but I suspect the most common cause is the server not having a private key and certificate at all.



Get rid of this line. Your server is insecure enough already with that insecure TrustManager. Then run your server with,handshake, try one connect, and post the resulting output here.

Exception: Unexpected end of ZLIB input stream

You have to call close() on the GZIPOutputStream before you attempt to read it. The final bytes of the file will only be written when the file is actually closed. (This is irrespective of any explicit buffering in the output stack. The stream only knows to compress and write the last bytes when you tell it to close. A flush() probably won't help ... though calling finish() instead of close() should work. Look at the javadocs.)

Here's the correct code (in Java);

package test;


public class GZipTest {

    public static void main(String[] args) throws
                FileNotFoundException, IOException {
        String name = "/tmp/test";
        GZIPOutputStream gz = new GZIPOutputStream(new FileOutputStream(name));
        gz.close();       // Remove this to reproduce the reported bug
        System.out.println(new GZIPInputStream(new FileInputStream(name)).read());

(I've not implemented resource management or exception handling / reporting properly as they are not relevant to the purpose of this code. Don't treat this as an example of "good code".)

How to import component into another root component in Angular 2

For Angular RC5 and RC6 you have to declare component in the module metadata decorator's declarations key, so add CoursesComponent in your main module declarations as below and remove directives from AppComponent metadata.

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

import { AppComponent } from './app.component';
import { CoursesComponent } from './courses.component';

  imports:      [ BrowserModule ],
  declarations: [ AppComponent, CoursesComponent ],
  bootstrap:    [ AppComponent ]
export class AppModule { }

How to overwrite the previous print to stdout in python?

I had the same question before visiting this thread. For me the sys.stdout.write worked only if I properly flush the buffer i.e.

for x in range(10):

Without flushing, the result is printed only at the end out the script

Why do I get a warning icon when I add a reference to an MEF plugin project?

It's been a long time since this question was asked but if someone is still interested - I recently ran into similar icons. I was compiling a project using VS 2008. I found VS could not locate the assemblies for those references. When I double clicked VS refreshed the references and removed the icons on some of those[EDIT: which it could NOW locate]. For remaining references, I had to compile the respective assemblies.

How can I share Jupyter notebooks with non-programmers?

The "best" way to share a Jupyter notebook is to simply to place it on GitHub (and view it directly) or some other public link and use the Jupyter Notebook Viewer. When privacy is more of an issue then there are alternatives but it's certainly more complex; there's no built-in way to do this in Jupyter alone, but a couple of options are:

Host your own nbviewer

GitHub and the Jupyter Notebook Veiwer both use the same tool to render .ipynb files into static HTML, this tool is nbviewer.

The installation instructions are more complex than I'm willing to go into here but if your company/team has a shared server that doesn't require password access then you could host the nbviewer on that server and direct it to load from your credentialed server. This will probably require some more advanced configuration than you're going to find in the docs.

Set up a deployment script

If you don't necessarily need live updating HTML then you could set up a script on your credentialed server that will simply use Jupyter's built-in export options to create the static HTML files and then send those to a more publicly accessible server.

How to find path of active app.config file?

The first time I realized that the Unit testing project referenced the app.config in that project rather then the app.config associated with my production code project (off course, DOH) I just added a line in the Post Build Event of the Prod project that will copy the app.config to the bin folder of the test project.

Problem solved

I haven't noticed any weird side effects so far, but I am not sure that this is the right solution, but at least it seems to work.

Adding background image to div using CSS

It is happening because .header-shadow is empty.

Add height to it:

    background-image: url('../images/header-shade.jpg');
    background-color: red;
    height: 50px;

Fiddle here.

Explode PHP string by new line

First of all, I think it's usually \r\n, second of all, those are not the same on all systems. That will only work on windows. It's kind-of annoying trying to figure out how to replace new lines because different systems treat them differently (see here). You might have better luck with just \n.

Can I change the viewport meta tag in mobile safari on the fly?

I realize this is a little old, but, yes it can be done. Some javascript to get you started:

viewport = document.querySelector("meta[name=viewport]");
viewport.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0');

Just change the parts you need and Mobile Safari will respect the new settings.


If you don't already have the meta viewport tag in the source, you can append it directly with something like this:

var metaTag=document.createElement('meta'); = "viewport"
metaTag.content = "width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0"

Or if you're using jQuery:

$('head').append('<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">');

How to add elements of a Java8 stream into an existing List

I would concatenate the old list and new list as streams and save the results to destination list. Works well in parallel, too.

I will use the example of accepted answer given by Stuart Marks:

List<String> destList = Arrays.asList("foo");
List<String> newList = Arrays.asList("0", "1", "2", "3", "4", "5");

destList = Stream.concat(,

//output: [foo, 0, 1, 2, 3, 4, 5]

Hope it helps.

Extract the last substring from a cell

This works, even when there are middle names:


If you want everything BUT the last name, check out this answer.

If there are trailing spaces in your names, then you may want to remove them by replacing all instances of A2 by TRIM(A2) in the above formula.

Note that it is only by pure chance that your first formula =RIGHT(A2,FIND(" ",A2,1)-1) kind of works for Alistair Stevens. This is because "Alistair" and " Stevens" happen to contain the same number of characters (if you count the leading space in " Stevens").

correct way to use super (argument passing)

Sometimes two classes may have some parameter names in common. In that case, you can't pop the key-value pairs off of **kwargs or remove them from *args. Instead, you can define a Base class which unlike object, absorbs/ignores arguments:

class Base(object):
    def __init__(self, *args, **kwargs): pass

class A(Base):
    def __init__(self, *args, **kwargs):
        print "A"
        super(A, self).__init__(*args, **kwargs)

class B(Base):
    def __init__(self, *args, **kwargs):
        print "B"
        super(B, self).__init__(*args, **kwargs)

class C(A):
    def __init__(self, arg, *args, **kwargs):
        print "C","arg=",arg
        super(C, self).__init__(arg, *args, **kwargs)

class D(B):
    def __init__(self, arg, *args, **kwargs):
        print "D", "arg=",arg
        super(D, self).__init__(arg, *args, **kwargs)

class E(C,D):
    def __init__(self, arg, *args, **kwargs):
        print "E", "arg=",arg
        super(E, self).__init__(arg, *args, **kwargs)

print "MRO:", [x.__name__ for x in E.__mro__]


MRO: ['E', 'C', 'A', 'D', 'B', 'Base', 'object']
E arg= 10
C arg= 10
D arg= 10

Note that for this to work, Base must be the penultimate class in the MRO.

@Html.DisplayFor - DateFormat ("mm/dd/yyyy")

If you use DisplayFor, then you have to either define the format via the DisplayFormat attribute or use a custom display template. (A full list of preset DisplayFormatString's can be found here.)

[DisplayFormat(DataFormatString = "{0:d}")]
public DateTime? AuditDate { get; set; }

Or create the view Views\Shared\DisplayTemplates\DateTime.cshtml:

@model DateTime?
@if (Model.HasValue)

That will apply to all DateTimes, though, even ones where you're encoding the time as well. If you want it to apply only to date-only properties, then use Views\Shared\DisplayTemplates\Date.cshtml and the DataType attribute on your property:

public DateTime? AuditDate { get; set; }

The final option is to not use DisplayFor and instead render the property directly:

@if (Model.AuditDate.HasValue)

CSS Font Border?

Stroke font-character with a Less mixin

Here's a LESS mixin to generate the stroke:

/// Stroke font-character
/// @param  {Integer} $stroke - Stroke width
/// @param  {Color}   $color  - Stroke color
/// @return {List}            - text-shadow list
.stroke(@stroke, @color) {
  @maxi: @stroke + 1;
  .i-loop (@i) when (@i > 0) {
    @maxj: @stroke + 1;
    .j-loop (@j) when (@j > 0) {
      text-shadow+: (@i - 1)*(1px)  (@j - 1)*(1px) 0 @color;
      text-shadow+: (@i - 1)*(1px)  (@j - 1)*(-1px) 0 @color;
      text-shadow+: (@i - 1)*(-1px)  (@j - 1)*(-1px) 0 @color;
      text-shadow+: (@i - 1)*(-1px)  (@j - 1)*(1px) 0 @color;
      .j-loop(@j - 1);
    .j-loop (0) {}
    .i-loop(@i - 1);
  .i-loop (0) {}
  text-shadow+: 0 0 0 @color;

(it's based on pixelass answer that instead uses SCSS)

Strip last two characters of a column in MySQL

You can use a LENGTH(that_string) minus the number of characters you want to remove in the SUBSTRING() select perhaps or use the TRIM() function.

When should you use a class vs a struct in C++?

The only time I use a struct instead of a class is when declaring a functor right before using it in a function call and want to minimize syntax for the sake of clarity. e.g.:

struct Compare { bool operator() { ... } };
std::sort(collection.begin(), collection.end(), Compare()); 

efficient way to implement paging

We use a CTE wrapped in Dynamic SQL (because our application requires dynamic sorting of data server side) within a stored procedure. I can provide a basic example if you'd like.

I haven't had a chance to look at the T/SQL that LINQ produces. Can someone post a sample?

We don't use LINQ or straight access to the tables as we require the extra layer of security (granted the dynamic SQL breaks this somewhat).

Something like this should do the trick. You can add in parameterized values for parameters, etc.

exec sp_executesql 'WITH MyCTE AS (
    SELECT TOP (10) ROW_NUMBER () OVER ' + @SortingColumn + ' as RowID, Col1, Col2
    FROM MyTable
    WHERE Col4 = ''Something''
WHERE RowID BETWEEN 10 and 20'

Disabling Minimize & Maximize On WinForm?

public Form1()
//this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
this.MaximizeBox = false;
this.MinimizeBox = false;

How to Clone Objects

a and b are just two references to the same Person object. They both essentially hold the address of the Person.

There is a ICloneable interface, though relatively few classes support it. With this, you would write:

Person b = a.Clone();

Then, b would be an entirely separate Person.

You could also implement a copy constructor:

public Person(Person src)
  // ... 

There is no built-in way to copy all the fields. You can do it through reflection, but there would be a performance penalty.

How to remove all characters after a specific character in python?

The method find will return the character position in a string. Then, if you want remove every thing from the character, do this:

mystring = "123?567"
mystring[ 0 : mystring.index("?")]

>> '123'

If you want to keep the character, add 1 to the character position.

Python Threading String Arguments

I hope to provide more background knowledge here.

First, constructor signature of the of method threading::Thread:

class threading.Thread(group=None, target=None, name=None, args=(), kwargs={}, *, daemon=None)

args is the argument tuple for the target invocation. Defaults to ().

Second, A quirk in Python about tuple:

Empty tuples are constructed by an empty pair of parentheses; a tuple with one item is constructed by following a value with a comma (it is not sufficient to enclose a single value in parentheses).

On the other hand, a string is a sequence of characters, like 'abc'[1] == 'b'. So if send a string to args, even in parentheses (still a sting), each character will be treated as a single parameter.

However, Python is so integrated and is not like JavaScript where extra arguments can be tolerated. Instead, it throws an TypeError to complain.

Drop data frame columns by name

Another possibility:

df <- df[, setdiff(names(df), c("a", "c"))]


df <- df[, grep('^(a|c)$', names(df), invert=TRUE)]

psycopg2: insert multiple rows with one query

If you're using SQLAlchemy, you don't need to mess with hand-crafting the string because SQLAlchemy supports generating a multi-row VALUES clause for a single INSERT statement:

rows = []
for i, name in enumerate(rawdata):
    row = {
        'id': i,
        'name': name,
        'valid': True,
if len(rows) > 0:  # INSERT fails if no rows
    insert_query = SQLAlchemyModelName.__table__.insert().values(rows)

Angular2 - TypeScript : Increment a number after timeout in AppComponent

You should put your processing into the class constructor or an OnInit hook method.

URL encoding in Android

I'm going to add one suggestion here. You can do this which avoids having to get any external libraries.

Give this a try:

String urlStr = " 15sec h.264.mp4";
URL url = new URL(urlStr);
URI uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef());
url = uri.toURL();

You can see that in this particular URL, I need to have those spaces encoded so that I can use it for a request.

This takes advantage of a couple features available to you in Android classes. First, the URL class can break a url into its proper components so there is no need for you to do any string search/replace work. Secondly, this approach takes advantage of the URI class feature of properly escaping components when you construct a URI via components rather than from a single string.

The beauty of this approach is that you can take any valid url string and have it work without needing any special knowledge of it yourself.

Using pg_dump to only get insert statements from one table within database

Put into a script I like something like that:

set -o xtrace # remove me after debug

LOCATION="${BASE_DIR}/myApp_$(date +%Y%m%d_%H%M%S)"

# Create backups directory if not exists
if [[ ! -e $BASE_DIR ]];then
       mkdir $BASE_DIR
       chown -R postgres:postgres $BASE_DIR

sudo -H -u postgres pg_dump --column-inserts --data-only --table=$TABLE $DB_NAME > $FNAME
sudo gzip $FNAME

How to transition to a new view controller with code only using Swift


Usually for normal transition we use,

let next:SecondViewController = SecondViewController()
self.presentViewController(next, animated: true, completion: nil)

But sometimes when using navigation controller, you might face a black screen. In that case, you need to use like,

let next:ThirdViewController = storyboard?.instantiateViewControllerWithIdentifier("ThirdViewController") as! ThirdViewController
self.navigationController?.pushViewController(next, animated: true)

Moreover none of the above solution preserves navigationbar when you call from storyboard or single xib to another xib. If you use nav bar and want to preserve it just like normal push, you have to use,

Let's say, "MyViewController" is identifier for MyViewController

let viewController = MyViewController(nibName: "MyViewController", bundle: nil)
self.navigationController?.pushViewController(viewController, animated: true)

Block direct access to a file over http but allow php script access

How about custom module based .htaccess script (like its used in CodeIgniter)? I tried and it worked good in CodeIgniter apps. Any ideas to use it on other apps?

<IfModule authz_core_module>
    Require all denied
<IfModule !authz_core_module>
    Deny from all

bash "if [ false ];" returns true instead of false -- why?

Using true/false removes some bracket clutter...

#! /bin/bash    
#  true_or_false.bash

[ "$(basename $0)" == "bash" ] && sourced=true || sourced=false

$sourced && echo "SOURCED"
$sourced || echo "CALLED"

# Just an alternate way:
! $sourced  &&  echo "CALLED " ||  echo "SOURCED"

$sourced && return || exit

How to create an AVD for Android 4.0

You can also get this problem if you have your Android SDK version controlled. You get a slightly different error:

Unable to find a 'userdata.img' file for ABI .svn to copy into the AVD folder.

For some reason, the Android Virtual Device (AVD) manager believes the .svn folder is specifying an application binary interface (ABI). It looks for userdata.img within the .svn folder and can't find it, so it fails.

I used the shell extension found in the responses for the Stack Overflow question Removing .svn files from all directories to remove all .svn folders recursively from the android-sdk folder. After this, the AVD manager was able to create an AVD successfully. I have yet to figure out how to get the SDK to play nicely with Subversion.

When do I need to use AtomicBoolean in Java?

Excerpt from the package description

Package java.util.concurrent.atomic description: A small toolkit of classes that support lock-free thread-safe programming on single variables.[...]

The specifications of these methods enable implementations to employ efficient machine-level atomic instructions that are available on contemporary processors.[...]

Instances of classes AtomicBoolean, AtomicInteger, AtomicLong, and AtomicReference each provide access and updates to a single variable of the corresponding type.[...]

The memory effects for accesses and updates of atomics generally follow the rules for volatiles:

  • get has the memory effects of reading a volatile variable.
  • set has the memory effects of writing (assigning) a volatile variable.
  • weakCompareAndSet atomically reads and conditionally writes a variable, is ordered with respect to other memory operations on that variable, but otherwise acts as an ordinary non-volatile memory operation.
  • compareAndSet and all other read-and-update operations such as getAndIncrement have the memory effects of both reading and writing volatile variables.

How to restore to a different database in sql server?

It is actually a bit simpler than restoring to the same server. Basically, you just walk through the "Restore Database" options. Here is a tutorial for you:

Especially since this is a non-production restore, you can feel comfortable just trying it out without worrying about the details too much. Just put your SQL files where you want them on your new server and give it whatever name you want and you are good to go.

Virtual member call in a constructor

One important missing bit is, what is the correct way to resolve this issue?

As Greg explained, the root problem here is that a base class constructor would invoke the virtual member before the derived class has been constructed.

The following code, taken from MSDN's constructor design guidelines, demonstrates this issue.

public class BadBaseClass
    protected string state;

    public BadBaseClass()
        this.state = "BadBaseClass";

    public virtual void DisplayState()

public class DerivedFromBad : BadBaseClass
    public DerivedFromBad()
        this.state = "DerivedFromBad";

    public override void DisplayState()

When a new instance of DerivedFromBad is created, the base class constructor calls to DisplayState and shows BadBaseClass because the field has not yet been update by the derived constructor.

public class Tester
    public static void Main()
        var bad = new DerivedFromBad();

An improved implementation removes the virtual method from the base class constructor, and uses an Initialize method. Creating a new instance of DerivedFromBetter displays the expected "DerivedFromBetter"

public class BetterBaseClass
    protected string state;

    public BetterBaseClass()
        this.state = "BetterBaseClass";

    public void Initialize()

    public virtual void DisplayState()

public class DerivedFromBetter : BetterBaseClass
    public DerivedFromBetter()
        this.state = "DerivedFromBetter";

    public override void DisplayState()

remove table row with specific id

ID attributes cannot start with a number and they should be unique. In any case, you can use :eq() to select a specific row using a 0-based integer:

// Remove the third row
$("#test tr:eq(2)").remove();

Alternatively, rewrite your HTML so that it's valid:

<table id="test">
 <tr id=test1><td>bla</td></tr>
 <tr id=test2><td>bla</td></tr>
 <tr id=test3><td>bla</td></tr>
 <tr id=test4><td>bla</td></tr>

And remove it referencing just the id:


CXF: No message body writer found for class - automatically mapping non-simple resources

In my scenario, i faced similar error, when the rest url without port number is not properly configured for load balancing. I verified the rest url with portnumber and this issue was not occurring. so we had to update the load balancing configuration to resolve this issue.

How do you use MySQL's source command to import large files in windows

On windows: Use explorer to navigate to the folder with the .sql file. Type cmd in the top address bar. Cmd will open. Type:

"C:\path\to\mysql.exe" -u "your_username" -p "your password" < "name_of_your_sql_file.sql"

Wait a bit and the sql file will have been executed on your database. Confirmed to work with MariaDB in feb 2018.

Error - "UNION operator must have an equal number of expressions" when using CTE for recursive selection

Although this an old post, I am sharing another working example.


Let us take an example:


In SQL if we write - SELECT 'column1', 'column2' (NOTE: remember to specify names in quotes) In a result set, it will display empty columns with two headers - column1 and column2

2: I share one simple instance I came across.

I had seven columns with few different datatypes in SQL. I.e. uniqueidentifier, datetime, nvarchar

My task was to retrieve comma separated result set with column header. So that when I export the data to CSV I have comma separated rows with first row as header and has respective column names.

SELECT CONVERT(NVARCHAR(36), 'Event ID') + ', ' + 
'Last Name' + ', ' + 
'First Name' + ', ' + 
'Middle Name' + ', ' + 
CONVERT(NVARCHAR(36), 'Document Type') + ', ' + 
'Event Type' + ', ' + 
CONVERT(VARCHAR(23), 'Last Updated', 126)


SELECT CONVERT(NVARCHAR(36), inspectionid) + ', ' + 
       individuallastname + ', ' + 
       individualfirstname + ', ' + 
       individualmiddlename + ', ' +
       CONVERT(NVARCHAR(36), documenttype) + ', ' + 
       'I' + ', ' +
       CONVERT(VARCHAR(23), modifiedon, 126)
FROM Inspection

Above, columns 'inspectionid' & 'documenttype' has uniqueidentifer datatype and so applied CONVERT(NVARCHAR(36)). column 'modifiedon' is datetime and so applied CONVERT(NVARCHAR(23), 'modifiedon', 126).

Parallel to above 2nd SELECT query matched 1st SELECT query as per datatype of each column.

Git push error pre-receive hook declined

In my case, my team lead to created a repo(repo was empty) and assign me as developer so when I pushed to the code directly to master the error I was facing ! [remote rejected] master -> master (pre-receive hook declined) So how it was fixed that he assigned to me as maintainer so I was able to push the code directly to the master.

Updating a date in Oracle SQL table

This is based on the assumption that you're getting an error about the date format, such as an invalid month value or non-numeric character when numeric expected.

Dates stored in the database do not have formats. When you query the date your client is formatting the date for display, as 4/16/2011. Normally the same date format is used for selecting and updating dates, but in this case they appear to be different - so your client is apparently doing something more complicated that SQL*Plus, for example.

When you try to update it it's using a default date format model. Because of how it's displayed you're assuming that is MM/DD/YYYY, but it seems not to be. You could find out what it is, but it's better not to rely on the default or any implicit format models at all.

Whether that is the problem or not, you should always specify the date model:


Since you aren't specifying a time component - all Oracle DATE columns include a time, even if it's midnight - you could also use a date literal:


You should maybe check that the current value doesn't include a time, though the column name suggests it doesn't.

golang why don't we have a set datastructure

One reason is that it is easy to create a set from map:

s := map[int]bool{5: true, 2: true}
_, ok := s[6] // check for existence
s[8] = true // add element 
delete(s, 2) // remove element


s_union := map[int]bool{}
for k, _ := range s1{
    s_union[k] = true
for k, _ := range s2{
    s_union[k] = true


s_intersection := map[int]bool{}
for k,_ := range s1 { 
  if s2[k] {
    s_intersection[k] = true

It is not really that hard to implement all other set operations.

How to use Checkbox inside Select Option

If you want to create multiple select dropdowns in the same page:

.multiselect {
  width: 200px;

.selectBox {
  position: relative;

.selectBox select {
  width: 100%;
  font-weight: bold;

.overSelect {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;

#checkboxes {
  display: none;
  border: 1px #dadada solid;

#checkboxes label {
  display: block;

#checkboxes label:hover {
  background-color: #1e90ff;


<div class="multiselect">
<div class="selectBox" onclick="showCheckboxes()">
<option>Select an option</option>
<div class="overSelect"></div>
<div id="checkboxes">
<label for="one">
<input type="checkbox" id="one" />First checkbox</label>
<label for="two">
<input type="checkbox" id="two" />Second checkbox</label>
<label for="three">
<input type="checkbox" id="three" />Third checkbox</label>
<div class="multiselect">
<div class="selectBox" onclick="showCheckboxes()">
<option>Select an option</option>
<div class="overSelect"></div>
<div id="checkboxes">
<label for="one">
<input type="checkbox" id="one" />First checkbox</label>
<label for="two">
<input type="checkbox" id="two" />Second checkbox</label>
<label for="three">
<input type="checkbox" id="three" />Third checkbox</label>


Using Jquery:

 function showCheckboxes(elethis) {

How to have comments in IntelliSense for function in Visual Studio?

Define Methods like this and you will get the help you need.

    /// <summary>
    /// Adds two numbers and returns the result
    /// </summary>
    /// <param name="first">first number to add</param>
    /// <param name="second">second number to </param>
    /// <returns></returns>
    private int Add(int first, int second)
        return first + second;

Screenshot of the code usage

HTML embedded PDF iframe

Try this out.

<iframe src="" frameborder="0" height="100%" width="100%">_x000D_

Reactjs setState() with a dynamic key name?

Can use a spread syntax, something like this:

inputChangeHandler : function (event) {
    this.setState( { 
    } );

Why do people say that Ruby is slow?

Here's what the creator of Rails, David Heinemeier Hansson has to say:

Rails [Ruby] is for the vast majority of web applications Fast Enough. We got sites doing millions of dynamic page views per day. If you end up being with the Yahoo or Amazon front page, it's unlikely that an off-the-shelve framework in ANY language will do you much good. You'll probably have to roll your own. But sure, I'd like free CPU cycles too. I just happen to care much more about free developer cycles and am willing to trade the former for the latter.

i.e. throwing more hardware or machines at the problem is cheaper than hiring more developers and using a faster, but harder to maintain language. After all, few people write web applications in C.

Ruby 1.9 is a vast improvement over 1.8. The biggest problems with Ruby 1.8 are its interpreted nature (no bytecode, no compilation) and that method calls, one of the most common operations in Ruby, are particularly slow.

It doesn't help that pretty much everything is a method lookup in Ruby - adding two numbers, indexing an array. Where other languages expose hacks (Python's __add__ method, Perl's Ruby does pure OO in all cases, and this can hurt performance if the compiler/interpreter is not clever enough.

If I were writing a popular web application in Ruby, my focus would be on caching. Caching a page reduces the processing time for that page to zero, whatever language you are using. For web applications, database overhead and other I/O begins to matter a lot more than the speed of the language, so I would focus on optimising that.

Git command to checkout any branch and overwrite local changes

You could follow a solution similar to "How do I force “git pull” to overwrite local files?":

git fetch --all
git reset --hard origin/abranch
git checkout $branch 

That would involve only one fetch.

With Git 2.23+, git checkout is replaced here with git switch (presented here) (still experimental).

git switch -f $branch

(with -f being an alias for --discard-changes, as noted in Jan's answer)

Proceed even if the index or the working tree differs from HEAD.
Both the index and working tree are restored to match the switching target.

How do I delete all messages from a single queue using the CLI?

I guess its late but for others reference, this can be done with pika

import pika
host_ip = #host ip
channel = pika.BlockingConnection(pika.ConnectionParameters(host_ip,
print "deleting queue..", channel.queue_delete(queue=queue_name)

Explain why constructor inject is better than other options

To make it simple, let us say that we can use constructor based dependency injection for mandatory dependencies and setter based injection for optional dependencies. It is a rule of thumb!!

Let's say for example.

If you want to instantiate a class you always do it with its constructor. So if you are using constructor based injection, the only way to instantiate the class is through that constructor. If you pass the dependency through constructor it becomes evident that it is a mandatory dependency.

On the other hand, if you have a setter method in a POJO class, you may or may not set value for your class variable using that setter method. It is completely based on your need. i.e. it is optional. So if you pass the dependency through setter method of a class it implicitly means that it is an optional dependency. Hope this is clear!!

Read Excel File in Python

This is one approach:

from xlrd import open_workbook

class Arm(object):
    def __init__(self, id, dsp_name, dsp_code, hub_code, pin_code, pptl): = id
        self.dsp_name = dsp_name
        self.dsp_code = dsp_code
        self.hub_code = hub_code
        self.pin_code = pin_code
        self.pptl = pptl

    def __str__(self):
        return("Arm object:\n"
               "  Arm_id = {0}\n"
               "  DSPName = {1}\n"
               "  DSPCode = {2}\n"
               "  HubCode = {3}\n"
               "  PinCode = {4} \n"
               "  PPTL = {5}"
               .format(, self.dsp_name, self.dsp_code,
                       self.hub_code, self.pin_code, self.pptl))

wb = open_workbook('sample.xls')
for sheet in wb.sheets():
    number_of_rows = sheet.nrows
    number_of_columns = sheet.ncols

    items = []

    rows = []
    for row in range(1, number_of_rows):
        values = []
        for col in range(number_of_columns):
            value  = (sheet.cell(row,col).value)
                value = str(int(value))
            except ValueError:
        item = Arm(*values)

for item in items:
    print item
    print("Accessing one single value (eg. DSPName): {0}".format(item.dsp_name))

You don't have to use a custom class, you can simply take a dict(). If you use a class however, you can access all values via dot-notation, as you see above.

Here is the output of the script above:

Arm object:
  Arm_id = 1
  DSPName = JaVAS
  DSPCode = 1
  HubCode = AGR
  PinCode = 282001 
  PPTL = 1
Accessing one single value (eg. DSPName): JaVAS

Arm object:
  Arm_id = 2
  DSPName = JaVAS
  DSPCode = 1
  HubCode = AGR
  PinCode = 282002 
  PPTL = 3
Accessing one single value (eg. DSPName): JaVAS

Arm object:
  Arm_id = 3
  DSPName = JaVAS
  DSPCode = 1
  HubCode = AGR
  PinCode = 282003 
  PPTL = 5
Accessing one single value (eg. DSPName): JaVAS

What is the difference between String and StringBuffer in Java?

A StringBuffer is used to create a single string from many strings, e.g. when you want to append parts of a String in a loop.

You should use a StringBuilder instead of a StringBuffer when you have only a single Thread accessing the StringBuffer, since the StringBuilder is not synchronized and thus faster.

AFAIK there is no upper limit for String size in Java as a language, but the JVMs probably have an upper limit.

POSTing JsonObject With HttpClient From Web API

With the new version of HttpClient and without the WebApi package it would be:

var content = new StringContent(jsonObject.ToString(), Encoding.UTF8, "application/json");
var result = client.PostAsync(url, content).Result;

Or if you want it async:

var result = await client.PostAsync(url, content);

Create autoincrement key in Java DB using NetBeans IDE

If you look at this url:

this part of the schema may be what you are looking for.

                (START WITH 1, INCREMENT BY 1),

Java Set retain order?

There are 2 different things.

  1. Sort the elements in a set. For which we have SortedSet and similar implementations.
  2. Maintain insertion order in a set. For which LinkedHashSet and CopyOnWriteArraySet (thread-safe) can be used.

How to tell when UITableView has completed ReloadData?

And a UICollectionView version, based on kolaworld's answer:

Needs testing. Works so far on iOS 9.2, Xcode 9.2 beta 2, with scrolling a collectionView to an index, as a closure.

extension UICollectionView
    /// Calls reloadsData() on self, and ensures that the given closure is
    /// called after reloadData() has been completed.
    /// Discussion: reloadData() appears to be asynchronous. i.e. the
    /// reloading actually happens during the next layout pass. So, doing
    /// things like scrolling the collectionView immediately after a
    /// call to reloadData() can cause trouble.
    /// This method uses CATransaction to schedule the closure.

    func reloadDataThenPerform(_ closure: @escaping (() -> Void))


myCollectionView.reloadDataThenPerform {
    myCollectionView.scrollToItem(at: indexPath,
            at: .centeredVertically,
            animated: true)

Emulator error: This AVD's configuration is missing a kernel file

I tried what ChrLipp suggested, but that wasn't the problem, as the image was already installed. What I did was run:

android avd

to start the emulator manually. Then I stopped the emulator, and form that point on the

cca emulate android

app started working, without the "missing a kernel file" error.

Twig ternary operator, Shorthand if-then-else

Support for the extended ternary operator was added in Twig 1.12.0.

  1. If foo echo yes else echo no:

    {{ foo ? 'yes' : 'no' }}
  2. If foo echo it, else echo no:

    {{ foo ?: 'no' }}


    {{ foo ? foo : 'no' }}
  3. If foo echo yes else echo nothing:

    {{ foo ? 'yes' }}


    {{ foo ? 'yes' : '' }}
  4. Returns the value of foo if it is defined and not null, no otherwise:

    {{ foo ?? 'no' }}
  5. Returns the value of foo if it is defined (empty values also count), no otherwise:

    {{ foo|default('no') }}

How to change button text or link text in JavaScript?

document.getElementById(button_id).innerHTML = 'Lock';

Positioning background image, adding padding

Updated Answer:

It's been commented multiple times that this is not the correct answer to this question, and I agree. Back when this answer was written, IE 9 was still new (about 8 months old) and many developers including myself needed a solution for <= IE 9. IE 9 is when IE started supporting background-origin. However, it's been over six and a half years, so here's the updated solution which I highly recommend over using an actual border. In case < IE 9 support is needed. My original answer can be found below the demo snippet. It uses an opaque border to simulate padding for background images.

#hello {
  padding-right: 10px;
  background: url("") no-repeat scroll right center #e8e8e8;
  background-origin: content-box;
<p id="hello">I want the background icon to have padding to it too!I want the background icon twant the background icon to have padding to it too!I want the background icon to have padding to it too!I want the background icon to have padding to it too!</p>

Original Answer:

you can fake it with a 10px border of the same color as the background:,html,live

#hello {
   border: 10px solid #e8e8e8;
   background-color: green;
   background: url("")
               no-repeat scroll right center #e8e8e8;

"query function not defined for Select2 undefined error"

use :

try {
catch(err) {


How to solve COM Exception Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))?

I have faced the same issue. After done some research i found fix for me and it may useful. The issue is not only related to re-installation as of my observation, it depends on access permissions also.

Step 1: Repair the particular COM object.

Step 2: Component Services > Computers > My Computer > DCOM Config > Select your COM object > Right click > Properties > Security tab > Access Permissions > Choose Customize > Click EDIT > Select IIS_USER (If not exists create with complete rights) and give complete access and click OK.

Move to Identity tab > You can select "Interactive user" or "This user" > Click Apply and OK. If you choose "This user", we have to give Administrative privileged user to that server

Step 3: Open IIS Manager > Restart the Application Pools.

Note: If required please restart the server

Clicking at coordinates without identifying element

If using a commercial add-on to Selenium is an option for you, this is possible: Suppose your button is at coordinates x=123, y=456. Then you can use Helium to click on the element at these coordinates as follows:

from helium.api import *
# Tell Helium about your WebDriver instance:
click(Point(123, 456))

(I am one of Helium's authors.)

Capture iOS Simulator video for App Preview

The best tool I have found is Appshow. Visit (I do not work for them)

SQLSTATE[HY000] [2002] Connection refused within Laravel homestead

I found that my server just needed to be restarted and "bam" it was fixed.

Removing the password from a VBA project

This has a simple method using SendKeys to unprotect the VBA project. This would get you into the project, so you'd have to continue on using SendKeys to figure out a way to remove the password protection:

And here's one that uses a more advanced, somewhat more reliable method for unprotecting. Again, it will only unlock the VB project for you.

I haven't tried either method, but this may save you some time if it's what you need to do...

.htaccess, order allow, deny, deny from all: confused?

This is a quite confusing way of using Apache configuration directives.

Technically, the first bit is equivalent to

Allow From All

This is because Order Deny,Allow makes the Deny directive evaluated before the Allow Directives. In this case, Deny and Allow conflict with each other, but Allow, being the last evaluated will match any user, and access will be granted.

Now, just to make things clear, this kind of configuration is BAD and should be avoided at all cost, because it borders undefined behaviour.

The Limit sections define which HTTP methods have access to the directory containing the .htaccess file.

Here, GET and POST methods are allowed access, and PUT and DELETE methods are denied access. Here's a link explaining what the various HTTP methods are:

However, it's more than often useless to use these limitations as long as you don't have custom CGI scripts or Apache modules that directly handle the non-standard methods (PUT and DELETE), since by default, Apache does not handle them at all.

It must also be noted that a few other methods exist that can also be handled by Limit, namely CONNECT, OPTIONS, PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, and UNLOCK.

The last bit is also most certainly useless, since any correctly configured Apache installation contains the following piece of configuration (for Apache 2.2 and earlier):

# The following lines prevent .htaccess and .htpasswd files from being 
# viewed by Web clients. 
<Files ~ "^\.ht">
    Order allow,deny
    Deny from all
    Satisfy all

which forbids access to any file beginning by ".ht".

The equivalent Apache 2.4 configuration should look like:

<Files ~ "^\.ht">
    Require all denied

Application Error - The connection to the server was unsuccessful. (file:///android_asset/www/index.html)

Extending loading Timeout Limit will not solve the problem which caused the error, it just will avoid the system to show the message but performance will be affected whatsoever.

Actual reason: You may be linking files or images to remote locations, and those resources are taking too long to load. (this is likely the most common error)

Definitive solution: move all the scripts, images and css needed to some local folders and load them locally ...

Performance will be increased and error will be effectively solved.

How do I get Flask to run on port 80?

you can easily disable any process running on port 80 and then run this command

flask run --host --port 80

or if u prefer running it within the .py file

if __name__ == "__main__":, port=80)

What is a deadlock?

A lock occurs when multiple processes try to access the same resource at the same time.

One process loses out and must wait for the other to finish.

A deadlock occurs when the waiting process is still holding on to another resource that the first needs before it can finish.

So, an example:

Resource A and resource B are used by process X and process Y

  • X starts to use A.
  • X and Y try to start using B
  • Y 'wins' and gets B first
  • now Y needs to use A
  • A is locked by X, which is waiting for Y

The best way to avoid deadlocks is to avoid having processes cross over in this way. Reduce the need to lock anything as much as you can.

In databases avoid making lots of changes to different tables in a single transaction, avoid triggers and switch to optimistic/dirty/nolock reads as much as possible.

How to find substring inside a string (or how to grep a variable)?

expr match "$LIST" '$SOURCE'

don't work because of this function search $SOURCE from begin of the string and return the position just after pattern $SOURCE if found else 0. So you must write another code:

expr match "$LIST" '.*'"$SOURCE" or expr "$LIST" : '.*'"$SOURCE"

The expression $SOURCE must be double quoted so as a parser may set substitution. Single quoted not substitute and the code above will search textual string $SOURCE from the beginning of the $LIST. If you need the beginning of the string subtract the length $SOURCE e.g ${#SOURCE}. You may write also

expr "$LIST" : ".*\($SOURCE\)"

This function just extract $SOURCE from $LIST and return it. You'll get empty string else. But they problem with double double quote. I don't know how it resolve without using additional variable. It's light solution. So you may write in C. There is ready function strstr. Don't use expr index, So is very attractive. But index search not substring and only first char.

ReferenceError: $ is not defined

Though my response is late, but it can still help.

lf you are using Spring Tool Suite and you still think that the JQuery file reference path is correct, then refresh your project whenever you modify the JQuery file.

You refresh by right-clicking on the project name -> refresh.

That's what solved mine.

How do I test a single file using Jest?

We are using nrwl-nx with Angular. In this case we can use this command:

npm test <ng-project> -- --testFile "file-name-part"


  • npm test will run the test script specified in package.json: "test": "ng test"
  • Thus the rest of the cmd will be passed to ng test
    • <ng-project> is the name of a project in angular.json
      • when you omit this parameter, the "defaultProject" (specified in angular.json) will be used (so you must specify it, when the test is not in your default project)
    • Next we must check which builder is used:
      • In angular.json navigate to "project" - "<ng-project>" - "architect" - "test"
      • and check the "builder", which in our case is: "@nrwl/jest:jest"
    • Now that we know the builder, we need to find the available cmd-line parameters
      • On the command line, run npm test <ng-project> -- --help to see all available options
      • Or check the online documentation
    • One of the options is --testFile which is used here

Export pictures from excel file into jpg using VBA

Thanks for the ideas! I used the above ideas to make a macro to do a bulk file conversion--convert every file of one format in a folder to another format.

This code requires a sheet with cells named "FilePath" (which must end in a "\"), "StartExt" (original file extension), and "EndExt" (desired file extension). Warning: it doesn't ask for confirmation before replacing existing files with the same name and extension.

Private Sub CommandButton1_Click()
    Dim path As String
    Dim pathExt As String
    Dim file As String
    Dim oldExt As String
    Dim newExt As String
    Dim newFile As String
    Dim shp As Picture
    Dim chrt As ChartObject
    Dim chrtArea As Chart

    Application.ScreenUpdating = False
    Application.DisplayAlerts = False

    'Get settings entered by user
    path = Range("FilePath")
    oldExt = Range("StartExt")
    pathExt = path & "*." & oldExt
    newExt = Range("EndExt")

    file = Dir(pathExt)

    Do While Not file = "" 'cycle through all images in folder of selected format
        Set shp = ActiveSheet.Pictures.Insert(path & file) 'Import image
        newFile = Replace(file, "." & oldExt, "." & newExt) 'Determine new file name
        Set chrt = ActiveSheet.ChartObjects.Add(0, 0, shp.Width, shp.Height) 'Create blank chart for embedding image
        Set chrtArea = chrt.Chart
        shp.CopyPicture 'Copy image to clipboard
        With chrtArea 'Paste image to chart, then export
            .Export (path & newFile)
        End With
        chrt.Delete 'Delete chart
        shp.Delete 'Delete imported image

        file = Dir 'Advance to next file

    Application.ScreenUpdating = True
    Application.DisplayAlerts = True

End Sub

size of NumPy array

This is called the "shape" in NumPy, and can be requested via the .shape attribute:

>>> a = zeros((2, 5))
>>> a.shape
(2, 5)

If you prefer a function, you could also use numpy.shape(a).

How to implement common bash idioms in Python?

I suggest the awesome online book Dive Into Python. It's how I learned the language originally.

Beyond teaching you the basic structure of the language, and a whole lot of useful data structures, it has a good chapter on file handling and subsequent chapters on regular expressions and more.

How do I find out which keystore was used to sign an app?

You can do this with the apksigner tool that is part of the Android SDK:

apksigner verify --print-certs my_app.apk

You can find apksigner inside the build-tools directory. For example: ~/Library/Android/sdk/build-tools/29.0.1/apksigner

Eclipse: The resource is not on the build path of a Java project

You can add the src folder to build path by:

  1. Select Java perspective.
  2. Right click on src folder.
  3. Select Build Path > Use a source folder.

And you are done. Hope this help.

EDIT: Refer to the Eclipse documentation

Update statement using with clause

If anyone comes here after me, this is the answer that worked for me.

NOTE: please make to read the comments before using this, this not complete. The best advice for update queries I can give is to switch to SqlServer ;)

update mytable t
set z = (
  with comp as (
    select b.*, 42 as computed 
    from mytable t 
    where bs_id = 1
  select c.computed
  from  comp c
  where =

Good luck,


What function is to replace a substring from a string in C?

You can use strrep()

char* strrep ( const char * cadena, const char * strf, const char * strr )

strrep (String Replace). Replaces 'strf' with 'strr' in 'cadena' and returns the new string. You need to free the returned string in your code after using strrep.

Parameters cadena The string with the text. strf The text to find. strr The replacement text.

Returns The text updated wit the replacement.

Project can be found at

How to get the last value of an ArrayList

There isn't an elegant way in vanilla Java.

Google Guava

The Google Guava library is great - check out their Iterables class. This method will throw a NoSuchElementException if the list is empty, as opposed to an IndexOutOfBoundsException, as with the typical size()-1 approach - I find a NoSuchElementException much nicer, or the ability to specify a default:

lastElement = Iterables.getLast(iterableList);

You can also provide a default value if the list is empty, instead of an exception:

lastElement = Iterables.getLast(iterableList, null);

or, if you're using Options:

lastElementRaw = Iterables.getLast(iterableList, null);
lastElement = (lastElementRaw == null) ? Option.none() : Option.some(lastElementRaw);

How do include paths work in Visual Studio?

To resume the working solutions in VisualStudio 2013 and 2015 too:

Add an include-path to the current project only

In Solution Explorer (a palette-window of the VisualStudio-mainwindow), open the shortcut menu for the project and choose Properties, and then in the left pane of the Property Pages dialog box, expand Configuration Properties and select VC++ Directories. Additional include- or lib-paths are specifyable there.

Its the what Stackunderflow and user1741137 say in the answers above. Its the what Microsoft explains in MSDN too.

Add an include-path to every new project automatically

Its the question, what Jay Elston is asking in a comment above and what is a very obvious and burning question in my eyes, what seems to be nonanswered here yet.

There exist regular ways to do it in VisualStudio (see, what in my experience are not working properly. In the sense, that it works only once, and thereafter, it is no more expandable and nomore removable. The approach of Steve Wilkinson in another close related thread of StackOverflow, editing the Microsoft-Factory-XML-file in the ‘program files’ - directory is probably a risky hack, as it isnt expected by Microsoft to meet there something foreign. The effect is potentally unpredictable. Well, I like rather to judge it risky not much, but anyway the best way to make VisualStudio work incomprehensible at least for someone else.

The what is working fine compared to, is the editing the corresponding User-XML-file:




For example:

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="">
  <ImportGroup Label="PropertySheets">
  <PropertyGroup Label="UserMacros" />
  <ItemDefinitionGroup />
  <ItemGroup />

Where the directory ‘C:\any-name\include’ will get prepended to the present include-path and the directory ‘C:\any-name\lib’ to the library-path. Here, we can edit it ago in an extending and removing sense and remove it all, removing thewhole content of the tag .

Its the what makes VisualStudio itself, doing it in the regular way what CurlyBrace describes. As said, it isnt editable in the CurlyBrace-way thereafter nomore, but in the XML-editing-way it is.

For more insight, see Brian Tyler@MSDN-Blog 2009, what is admittedly not very fresh, but always the what Microsoft is linking to.

psql: could not connect to server: No such file or directory (Mac OS X)

Hello world :)
The best but strange way for me was to do next things.

1) Download or other version. Add this app into /Applications/ folder.

2) Add a row (command) into the file .bash_profile (which is in my home directory):

export PATH=/Applications/$PATH
It's a PATH to psql from The row (command) runs every time console is started.

3) Launch from /Applications/ folder. It starts a local server (port is "5432" and host is "localhost").

4) After all of this manipulations I was glad to run $ createuser -SRDP user_name and other commands and to see that it worked! can be made to run every time your system starts.

5) Also if you wanna see your databases graphically you should install PG It's good way to see your postgres DB as pretty data-tables

Of, course, it's helpful only for local server. I will be glad if this instructions help others who has faced with this problem.

VBA Check if variable is empty

For a number, it is tricky because if a numeric cell is empty VBA will assign a default value of 0 to it, so it is hard for your VBA code to tell the difference between an entered zero and a blank numeric cell.

The following check worked for me to see if there was an actual 0 entered into the cell:

If CStr(rng.value) = "0" then
    'your code here'
End If

Send an Array with an HTTP Get

That depends on what the target server accepts. There is no definitive standard for this. See also a.o. Wikipedia: Query string:

While there is no definitive standard, most web frameworks allow multiple values to be associated with a single field (e.g. field1=value1&field1=value2&field2=value3).[4][5]

Generally, when the target server uses a strong typed programming language like Java (Servlet), then you can just send them as multiple parameters with the same name. The API usually offers a dedicated method to obtain multiple parameter values as an array.

String[] foo = request.getParameterValues("foo"); // [value1, value2, value3]

The request.getParameter("foo") will also work on it, but it'll return only the first value.

String foo = request.getParameter("foo"); // value1

And, when the target server uses a weak typed language like PHP or RoR, then you need to suffix the parameter name with braces [] in order to trigger the language to return an array of values instead of a single value.

$foo = $_GET["foo"]; // [value1, value2, value3]
echo is_array($foo); // true

In case you still use foo=value1&foo=value2&foo=value3, then it'll return only the first value.

$foo = $_GET["foo"]; // value1
echo is_array($foo); // false

Do note that when you send foo[]=value1&foo[]=value2&foo[]=value3 to a Java Servlet, then you can still obtain them, but you'd need to use the exact parameter name including the braces.

String[] foo = request.getParameterValues("foo[]"); // [value1, value2, value3]

OpenCV with Network Cameras

I enclosed C++ code for grabbing frames. It requires OpenCV version 2.0 or higher. The code uses cv::mat structure which is preferred to old IplImage structure.

#include "cv.h"
#include "highgui.h"
#include <iostream>

int main(int, char**) {
    cv::VideoCapture vcap;
    cv::Mat image;

    const std::string videoStreamAddress = "rtsp://cam_address:554/live.sdp"; 
    /* it may be an address of an mjpeg stream, 
    e.g. "http://user:pass@cam_address:8081/cgi/mjpg/mjpg.cgi?.mjpg" */

    //open the video stream and make sure it's opened
    if(! {
        std::cout << "Error opening video stream or file" << std::endl;
        return -1;

    //Create output window for displaying frames. 
    //It's important to create this window outside of the `for` loop
    //Otherwise this window will be created automatically each time you call
    //`imshow(...)`, which is very inefficient. 
    cv::namedWindow("Output Window");

    for(;;) {
        if(! {
            std::cout << "No frame" << std::endl;
        cv::imshow("Output Window", image);
        if(cv::waitKey(1) >= 0) break;

Update You can grab frames from H.264 RTSP streams. Look up your camera API for details to get the URL command. For example, for an Axis network camera the URL address might be:

// H.264 stream RTSP address, where is an IP address 
// and 554 is the port number

// if the camera is password protected
rtsp://username:[email protected]:554/axis-media/media.amp

Is there Selected Tab Changed Event in the standard WPF Tab Control

If anyone use WPF Modern UI,they cant use OnTabSelected event.but they can use SelectedSourceChanged event.

like this

<mui:ModernTab Layout="Tab" SelectedSourceChanged="ModernTab_SelectedSourceChanged" Background="Blue" AllowDrop="True" Name="tabcontroller" >

C# code is

private void ModernTab_SelectedSourceChanged(object sender, SourceEventArgs e)
          var links = ((ModernTab)sender).Links;

          var link = this.tabcontroller.Links.FirstOrDefault(l => l.Source == e.Source);

          if (link != null) {
              var index = this.tabcontroller.Links.IndexOf(link);

How to display hexadecimal numbers in C?

i use it like this:

printf("my number is 0x%02X\n",number);
// output: my number is 0x4A

Just change number "2" to any number of chars You want to print ;)

Check if a String contains a special character

This worked for me:

String s = "string";
if (Pattern.matches("[a-zA-Z]+", s)) {
} else {

How to check the gradle version in Android Studio?

File->Project Structure->Project pane->"Android plugin version".

Make sure you don't confuse the Gradle version with the Android plugin version. The former is the build system itself, the latter is the plugin to the build system that knows how to build Android projects

The order of keys in dictionaries

You could use OrderedDict (requires Python 2.7) or higher.

Also, note that OrderedDict({'a': 1, 'b':2, 'c':3}) won't work since the dict you create with {...} has already forgotten the order of the elements. Instead, you want to use OrderedDict([('a', 1), ('b', 2), ('c', 3)]).

As mentioned in the documentation, for versions lower than Python 2.7, you can use this recipe.