Programs & Examples On #Excel interop

Excel Interop is the layer using the COM Interop that allows .NET (VB or C#) to communicate with standard COM objects and libraries.

How do I auto size columns through the Excel interop objects?

Have a look at this article, it's not an exact match to your problem, but suits it:

How do I import from Excel to a DataSet using Microsoft.Office.Interop.Excel?

What about using Excel Data Reader (previously hosted here) an open source project on codeplex? Its works really well for me to export data from excel sheets.

The sample code given on the link specified:

FileStream stream = File.Open(filePath, FileMode.Open, FileAccess.Read);

//1. Reading from a binary Excel file ('97-2003 format; *.xls)
IExcelDataReader excelReader = ExcelReaderFactory.CreateBinaryReader(stream);
//2. Reading from a OpenXml Excel file (2007 format; *.xlsx)
IExcelDataReader excelReader = ExcelReaderFactory.CreateOpenXmlReader(stream);
//3. DataSet - The result of each spreadsheet will be created in the result.Tables
DataSet result = excelReader.AsDataSet();
//4. DataSet - Create column names from first row
excelReader.IsFirstRowAsColumnNames = true;
DataSet result = excelReader.AsDataSet();

//5. Data Reader methods
while (excelReader.Read())

//6. Free resources (IExcelDataReader is IDisposable)


After some search around, I came across this article: Faster MS Excel Reading using Office Interop Assemblies. The article only uses Office Interop Assemblies to read data from a given Excel Sheet. The source code is of the project is there too. I guess this article can be a starting point on what you trying to achieve. See if that helps


The code below takes an excel workbook and reads all values found, for each excel worksheet inside the excel workbook.

private static void TestExcel()
        ApplicationClass app = new ApplicationClass();
        Workbook book = null;
        Range range = null;

            app.Visible = false;
            app.ScreenUpdating = false;
            app.DisplayAlerts = false;

            string execPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().CodeBase);

            book = app.Workbooks.Open(@"C:\data.xls", Missing.Value, Missing.Value, Missing.Value
                                              , Missing.Value, Missing.Value, Missing.Value, Missing.Value
                                             , Missing.Value, Missing.Value, Missing.Value, Missing.Value
                                            , Missing.Value, Missing.Value, Missing.Value);
            foreach (Worksheet sheet in book.Worksheets)

                Console.WriteLine(@"Values for Sheet "+sheet.Index);

                // get a range to work with
                range = sheet.get_Range("A1", Missing.Value);
                // get the end of values to the right (will stop at the first empty cell)
                range = range.get_End(XlDirection.xlToRight);
                // get the end of values toward the bottom, looking in the last column (will stop at first empty cell)
                range = range.get_End(XlDirection.xlDown);

                // get the address of the bottom, right cell
                string downAddress = range.get_Address(
                    false, false, XlReferenceStyle.xlA1,
                    Type.Missing, Type.Missing);

                // Get the range, then values from a1
                range = sheet.get_Range("A1", downAddress);
                object[,] values = (object[,]) range.Value2;

                // View the values
                for (int i = 1; i <= values.GetLength(0); i++)
                    for (int j = 1; j <= values.GetLength(1); j++)
                        Console.Write("{0}\t", values[i, j]);

        catch (Exception e)
            range = null;
            if (book != null)
                book.Close(false, Missing.Value, Missing.Value);
            book = null;
            if (app != null)
            app = null;

In the above code, values[i, j] is the value that you need to be added to the dataset. i denotes the row, whereas, j denotes the column.

Closing Excel Application Process in C# after Data Access


         System.Diagnostics.Process[] process = System.Diagnostics.Process.GetProcessesByName("Excel");
         foreach (System.Diagnostics.Process p in process)
             if (!string.IsNullOrEmpty(p.ProcessName) && p.StartTime.AddSeconds(+10) > DateTime.Now)
                 catch { }

It Closes last 10 sec process with name "Excel"

HRESULT: 0x800A03EC on Worksheet.range

For others like me, who have the same exception:

It can also happen if you try to pass a null value instead of Missing.Value (or Type.Missing)


Worksheet worksheet = ...;
return worksheet.Range["A1", null]; //This call generates the error 0x800A03EC

return worksheet.Range["A1", Missing.Value]; //This works correctly

Exporting the values in List to excel

Depending on the environment you're wanting to do this in, it is possible by using the Excel Interop. It's quite a mess dealing with COM however and ensuring you clear up resources else Excel instances stay hanging around on your machine.

Checkout this MSDN Example if you want to learn more.

Depending on your format you could produce CSV or SpreadsheetML yourself, thats not too hard. Other alternatives are to use 3rd party libraries to do it. Obviously they cost money though.

How to fix 'Microsoft Excel cannot open or save any more documents'

Go to this key on Registry Editor (Run | Regedit) HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

change key Cache to something like C:\Windows\Temp

My similar problem was solved like this.



System.Runtime.InteropServices.COMException (0x800A03EC)

In my case, the problem was styling header as "Header 1" but that style was not exist in the Word that I get the error because it was not an Office in English Language.

Optimal way to Read an Excel file (.xls/.xlsx)

Try to use Aspose.cells library (not free, but trial is enough to read), it is quite good

Install-package Aspose.cells

There is sample code:

using Aspose.Cells;
using System;

namespace ExcelReader
    class Program
        static void Main(string[] args)
            // Replace path for your file
            readXLS(@"C:\MyExcelFile.xls"); // or "*.xlsx"

        public static void readXLS(string PathToMyExcel)
            //Open your template file.
            Workbook wb = new Workbook(PathToMyExcel);

            //Get the first worksheet.
            Worksheet worksheet = wb.Worksheets[0];

            //Get cells
            Cells cells = worksheet.Cells;

            // Get row and column count
            int rowCount = cells.MaxDataRow;
            int columnCount = cells.MaxDataColumn;

            // Current cell value
            string strCell = "";

            Console.WriteLine(String.Format("rowCount={0}, columnCount={1}", rowCount, columnCount));

            for (int row = 0; row <= rowCount; row++) // Numeration starts from 0 to MaxDataRow
                for (int column = 0; column <= columnCount; column++)  // Numeration starts from 0 to MaxDataColumn
                    strCell = "";
                    strCell = Convert.ToString(cells[row, column].Value);
                    if (String.IsNullOrEmpty(strCell))
                        // Do your staff here

How to count the number of rows in excel with data?

Found this approach on another site. It works with the new larger sizes of Excel and doesn't require you to hardcode the max number of rows and columns.

iLastRow = Cells(Rows.Count, "a").End(xlUp).Row
iLastCol = Cells(i, Columns.Count).End(xlToLeft).Column

Thanks to mudraker in Melborne, Australia

Get first and last date of current month with JavaScript or jQuery

I fixed it with Datejs

This is alerting the first day:

var fd =;
var firstday = fd.toString("MM/dd/yyyy");

This is for the last day:

var ld =;
var lastday = ld.toString("MM/dd/yyyy");

Post parameter is always null

I know the OP was originally sending a single string, but for future reference, it is also worth noting that malformed JSON will also arrive as null into the post method. In my case, a missing comma between two properties caused what was otherwise fine, to break.

docker error: /var/run/docker.sock: no such file or directory

You can quickly setup your environment using shellinit

At your command prompt execute:

$(boot2docker shellinit)  

That will populate and export the environment variables and initialize other features.

Two's Complement in Python

I'm using Python 3.4.0

In Python 3 we have some problems with data types transformation.

So... here I'll tell a tip for those (like me) that works a lot with hex strings.

I'll take an hex data and make an complement it:

a = b'acad0109'

compl = int(a,16)-pow(2,32)


result = -1397948151 or -0x5352fef7 or '-0b1010011010100101111111011110111'

Check if cookies are enabled

But to check whether cookies are enabled using isset($_COOKIE["cookie"]) you have to refresh. Im doing it ths way (with sessions based on cookies :)

$a = session_id();

$b = session_id();

if ($a == $b)
    echo"Cookies ON";
    echo"Cookies OFF";

open resource with relative path in Java

Supply the path relative to the classloader, not the class you're getting the loader from. For instance:


Why should I use the keyword "final" on a method parameter in Java?

Personally I don't use final on method parameters, because it adds too much clutter to parameter lists. I prefer to enforce that method parameters are not changed through something like Checkstyle.

For local variables I use final whenever possible, I even let Eclipse do that automatically in my setup for personal projects.

I would certainly like something stronger like C/C++ const.

React hooks useState Array

Try to keep your state minimal. There is no need to store

   const initialValue = [
    { id: 0,value: " --- Select a State ---" }];

as state. Separate the permanent from the changing

const ALL_STATE_VALS = [
    { id: 0,value: " --- Select a State ---" }
    { id: 1, value: "Alabama" },
    { id: 2, value: "Georgia" },
    { id: 3, value: "Tennessee" }

Then you can store just the id as your state:

const StateSelector = () =>{
  const [selectedStateOption, setselectedStateOption] = useState(0);

  return (
      <label>Select a State:</label>
        {, index) => (
          <option key={} selected={index===selectedStateOption}>{option.value}</option>

Disable Auto Zoom in Input "Text" tag - Safari on iPhone

After reading almost every single line here and testing the various solutions, this is, thanks to all who shared their solutions, what I came up with, tested and working for me on iPhone 7 iOS 10.x :

@media screen and (-webkit-min-device-pixel-ratio:0) {
    select:hover{font-size: initial;}
@media (min-width: 768px) {
    select:hover{font-size: inherit;}

It has some cons, though, noticeably a "jump" as result of the quick font size change occuring between the "hover"ed and "focus"ed states - and the redraw impact on performance

How to unzip files programmatically in Android?

Minimal example I used to unzip a specific file from my zipfile into my applications cache folder. I then read the manifest file using a different method.

private void unzipUpdateToCache() {
    ZipInputStream zipIs = new ZipInputStream(context.getResources().openRawResource(R.raw.update));
    ZipEntry ze = null;

    try {

        while ((ze = zipIs.getNextEntry()) != null) {
            if (ze.getName().equals("update/manifest.json")) {
                FileOutputStream fout = new FileOutputStream(context.getCacheDir().getAbsolutePath() + "/manifest.json");

                byte[] buffer = new byte[1024];
                int length = 0;

                while ((length =>0) {
                    fout.write(buffer, 0, length);
                zipIs .closeEntry();
        zipIs .close();

    } catch (IOException e) {


How to generate Class Diagram (UML) on Android Studio (IntelliJ Idea)

I have managed to to do it in a way. Perform all the steps as referenced by Michal Rowicki above.

  1. Open Visual Paradigm software.
  2. Create a new Project
  3. There would be an option on the Tools bar above that states Code and select Instant Reverse... from the drop down menu with Java language(or other)
  4. Select your application folder where your project is located and add it to the project(i have selected the complete folder application)
  5. The application should now appear on the left pane in Class Repository
  6. Then all you do is right click the project that you have added and select Reverse to new class diagram
  7. Select either you wish to have the packages included in the class diagram or just the class diagram of the project

Then it should appear on your screen and customize it as you wish

However i do not know if the plugin in Android Studio was necessary nevertheless it has worked in a way for me.

Maven does not find JUnit tests to run

Another reason for not running the test cases happened to me - I had a property named "test" for completely different purposes, but it interfered with the surefire plugin. Thus, please check your POMs for:

  <test>.... </test>

and remove it.

install cx_oracle for python

Try to reinstall it with the following code:

!pip install --proxy http://username:[email protected]:8080 --upgrade --force-reinstall cx_Oracle

Can a JSON value contain a multiline string

Not pretty good solution, but you can try the hjson tool. It allows you to write text multi-lined in editor and then converts it to the proper valid JSON format.

Note: it adds '\n' characters for the new lines, but you can simply delete them in any text editor with the "Replace all.." function.

Selecting the first "n" items with jQuery

You probably want to read up on slice. Your code will look something like this:


Enable & Disable a Div and its elements in Javascript

If you want to disable all the div's controls, you can try adding a transparent div on the div to disable, you gonna make it unclickable, also use fadeTo to create a disable appearance.

try this.

$('#DisableDiv').append('<div style="position: absolute;top:0;left:0;width: 100%;height:100%;z-index:2;opacity:0.4;filter: alpha(opacity = 50)"></div>');

How to make graphics with transparent background in R using ggplot2?

Updated with the theme() function, ggsave() and the code for the legend background:

df <- data.frame(y = d, x = 1, group = rep(c("gr1", "gr2"), 50))
p <- ggplot(df) +
  stat_boxplot(aes(x = x, y = y, color = group), 
               fill = "transparent" # for the inside of the boxplot

Fastest way is using using rect, as all the rectangle elements inherit from rect:

p <- p +
        rect = element_rect(fill = "transparent") # all rectangles

More controlled way is to use options of theme:

p <- p +
    panel.background = element_rect(fill = "transparent"), # bg of the panel
    plot.background = element_rect(fill = "transparent", color = NA), # bg of the plot
    panel.grid.major = element_blank(), # get rid of major grid
    panel.grid.minor = element_blank(), # get rid of minor grid
    legend.background = element_rect(fill = "transparent"), # get rid of legend bg = element_rect(fill = "transparent") # get rid of legend panel bg

To save (this last step is important):

ggsave(p, filename = "tr_tst2.png",  bg = "transparent")

How to get exit code when using Python subprocess communicate method?

This worked for me. It also prints the output returned by the child process

child = subprocess.Popen(serial_script_cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    retValRunJobsSerialScript = 0
    for line in child.stdout.readlines():
        print line           
    retValRunJobsSerialScript= child.returncode

Is it possible to simulate key press events programmatically?

As of 2019, this solution has worked for me:

  new KeyboardEvent("keydown", {
    key: "e",
    keyCode: 69, // example values.
    code: "KeyE", // put everything you need in this object.
    which: 69,
    shiftKey: false, // you don't need to include values
    ctrlKey: false,  // if you aren't going to use them.
    metaKey: false   // these are here for example's sake.

I used this in my browser game, in order to support mobile devices with a simulated keypad.

Clarification: This code dispatches a single keydown event, while a real key press would trigger one keydown event (or several of them if it is held longer), and then one keyup event when you release that key. If you need keyup events too, it is also possible to simulate keyup events by changing "keydown" to "keyup" in the code snippet.

This also sends the event to the entire webpage, hence the document. If you want only a specific element to receive the event, you can substitute document for the desired element.

How can I remove a child node in HTML using JavaScript?

You have to remove any event handlers you've set on the node before you remove it, to avoid memory leaks in IE

Where do I get servlet-api.jar from?

You can find a recent servlet-api.jar in Tomcat 6 or 7 lib directory. If you don't have Tomcat on your machine, download the binary distribution of version 6 or 7 from

How do I get the output of a shell command executed using into a variable from Jenkinsfile (groovy)?

quick answer is this:

sh "ls -l > commandResult"
result = readFile('commandResult').trim()

I think there exist a feature request to be able to get the result of sh step, but as far as I know, currently there is no other option.


EDIT2: Not quite sure since what version, but sh/bat steps now can return the std output, simply:

def output = sh returnStdout: true, script: 'ls -l'

What is the difference between require_relative and require in Ruby?

I just saw the RSpec's code has some comment on require_relative being O(1) constant and require being O(N) linear. So probably the difference is that require_relative is the preferred one than require.

How to add icons to React Native app

This is helpful for people struggling to find better site to generate icons and splashscreen

How to stop line breaking in vim

It is correct that set nowrap will allow you to paste in a long line without vi/vim adding newlines, but then the line is not visually wrapped for easy reading. It is instead just one long line that you have to scroll through.

To have the line visually wrap but not have newline characters inserted into it, have set wrap (which is probably default so not needed to set) and set textwidth=0.

On some systems the setting of textwidth=0 is default. If you don't find that to be the case, add set textwidth=0 to your .exrc file so that it becomes your user's default for all vi/vim sessions.

100% Min Height CSS layout

I agree with Levik as the parent container is set to 100% if you have sidebars and want them to fill the space to meet up with the footer you cannot set them to 100% because they will be 100 percent of the parent height as well which means that the footer ends up getting pushed down when using the clear function.

Think of it this way if your header is say 50px height and your footer is 50px height and the content is just autofitted to the remaining space say 100px for example and the page container is 100% of this value its height will be 200px. Then when you set the sidebar height to 100% it is then 200px even though it is supposed to fit snug in between the header and footer. Instead it ends up being 50px + 200px + 50px so the page is now 300px because the sidebars are set to the same height as the page container. There will be a big white space in the contents of the page.

I am using internet Explorer 9 and this is what I am getting as the effect when using this 100% method. I havent tried it in other browsers and I assume that it may work in some of the other options. but it will not be universal.

How to get File Created Date and Modified Date

You can do that using FileInfo class:

FileInfo fi = new FileInfo("path");
var created = fi.CreationTime;
var lastmodified = fi.LastWriteTime;

In a URL, should spaces be encoded using %20 or +?

When encoding query values, either form, plus or percent-20, is valid; however, since the bandwidth of the internet isn't infinite, you should use plus, since it's two fewer bytes.

How can I add a hint or tooltip to a label in C# Winforms?

System.Windows.Forms.ToolTip ToolTip1 = new System.Windows.Forms.ToolTip();
ToolTip1.SetToolTip( Label1, "Label for Label1");

How to create a private class method?

Just for the completeness, we can also avoid declaring private_class_method in a separate line. I personally don't like this usage but good to know that it exists.

private_class_method  def self.method_name
end validation to make sure textbox has integer values

There are several different ways you can handle this. You could add a RequiredFieldValidator as well as a RangeValidator (if that works for your case) or you could add a CustomFieldValidator.

Link to the CustomFieldValidator:

Link to MSDN Article on ASP.NET Validation:

jQuery - select all text from a textarea

To stop the user from getting annoyed when the whole text gets selected every time they try to move the caret using their mouse, you should do this using the focus event, not the click event. The following will do the job and works around a problem in Chrome that prevents the simplest version (i.e. just calling the textarea's select() method in a focus event handler) from working.



<textarea id="foo">Some text</textarea>

<script type="text/javascript">
    var textBox = document.getElementById("foo");
    textBox.onfocus = function() {;

        // Work around Chrome's little problem
        textBox.onmouseup = function() {
            // Prevent further mouseup intervention
            textBox.onmouseup = null;
            return false;

jQuery version:

$("#foo").focus(function() {
    var $this = $(this);

    // Work around Chrome's little problem
    $this.mouseup(function() {
        // Prevent further mouseup intervention
        return false;

Spring Security redirect to previous page after successful login

I have following solution and it worked for me.

Whenever login page is requested, write the referer value to the session:

@RequestMapping(value="/login", method = RequestMethod.GET)
public String login(ModelMap model,HttpServletRequest request) {

    String referrer = request.getHeader("Referer");
        request.getSession().setAttribute("url_prior_login", referrer);
    return "user/login";

Then, after successful login custom implementation of SavedRequestAwareAuthenticationSuccessHandler will redirect user to the previous page:

HttpSession session = request.getSession(false);
if (session != null) {
    url = (String) request.getSession().getAttribute("url_prior_login");

Redirect the user:

if (url != null) {

What's the best way to test SQL Server connection programmatically?

Here is my version based on the @peterincumbria answer:

using var scope = _serviceProvider.CreateScope();
var dbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
return await dbContext.Database.CanConnectAsync(cToken);

I'm using Observable for polling health checking by interval and handling return value of the function. try-catch is not needed here because: enter image description here

How do I add images in laravel view?

You should store your images, css and JS files in a public directory. To create a link to any of them, use asset() helper:

{{ asset('img/myimage.png') }}

As alternative, you could use amazing Laravel Collective package for building forms and HTML elements, so your code will look like this:

{{ HTML::image('img/myimage.png', 'a picture') }}

Best practice to validate null and empty collection in Java

You can use org.apache.commons.lang.Validate's "notEmpty" method:

Validate.notEmpty(myCollection) -> Validate that the specified argument collection is neither null nor a size of zero (no elements); otherwise throwing an exception.

Create a folder if it doesn't already exist

We should always modularise our code and I've written the same check it below... We first check the directory, if the directory is absent we create the directory.

$boolDirPresents = $this->CheckDir($DirectoryName);

if (!$boolDirPresents) {
        $boolCreateDirectory = $this->CreateDirectory($DirectoryName);
        if ($boolCreateDirectory) {
        echo "Created successfully";

function CheckDir($DirName) {
    if (file_exists($DirName)) {
        echo "Dir Exists<br>";
        return true;
    } else {
        echo "Dir Not Absent<br>";
        return false;

function CreateDirectory($DirName) {
    if (mkdir($DirName, 0777)) {
        return true;
    } else {
        return false;

Adding content to a linear layout dynamically?

LinearLayout layout = (LinearLayout)findViewById(;
View child = getLayoutInflater().inflate(R.layout.child, null);

What is ANSI format?

ANSI (aka Windows-1252/WinLatin1) is a character encoding of the Latin alphabet, fairly similar to ISO-8859-1. You may want to take a look of it at Wikipedia.

Defining arrays in Google Scripts

This may be of help to a few who are struggling like I was:

var data = myform.getRange("A:AA").getValues().pop();
var myvariable1 = data[4];
var myvariable2 = data[7];

You don't have write permissions for the /Library/Ruby/Gems/2.3.0 directory. (mac user)

Solution for Mac

  1. Install/update RVM with last ruby version

    \curl -sSL | bash -s stable

  2. Install bundler

    gem install bundler

after this two commands (sudo) gem install .... started to work

How to insert a newline in front of a pattern?

echo pattern | sed -E -e $'s/^(pattern)/\\\n\\1/'

worked fine on El Captitan with () support

Checking for an empty field with MySQL

There's a difference between an empty string (email != "") and NULL. NULL is null and an Empty string is something.

Android: how to draw a border to a LinearLayout

Extend LinearLayout/RelativeLayout and use it straight on the XML

package com.pkg_name ;
public class LinearLayoutOutlined extends LinearLayout {
    Paint paint;    

    public LinearLayoutOutlined(Context context) {
        // TODO Auto-generated constructor stub
        setWillNotDraw(false) ;
        paint = new Paint();
    public LinearLayoutOutlined(Context context, AttributeSet attrs) {
        super(context, attrs);
        // TODO Auto-generated constructor stub
        setWillNotDraw(false) ;
        paint = new Paint();
    protected void onDraw(Canvas canvas) {
        Paint fillPaint = paint;
        fillPaint.setARGB(255, 0, 255, 0);
        canvas.drawPaint(fillPaint) ;

        Paint strokePaint = paint;
        strokePaint.setARGB(255, 255, 0, 0);
        Rect r = canvas.getClipBounds() ;
        Rect outline = new Rect( 1,1,r.right-1, r.bottom-1) ;
        canvas.drawRect(outline, strokePaint) ;


<?xml version="1.0" encoding="utf-8"?>

   ... your widgets here ...


How to atomically delete keys matching a pattern using Redis

I support all answers related to having some tool or execute Lua expression.

One more option from my side:

In our production and pre-production databases there are thousands of keys. Time to time we need to delete some keys (by some mask), modify by some criteria etc. Of course, there is no way to do it manually from CLI, especially having sharding (512 logical dbs in each physical).

For this purpose I write java client tool that does all this work. In case of keys deletion the utility can be very simple, only one class there:

public class DataCleaner {

    public static void main(String args[]) {
        String keyPattern = args[0];
        String host = args[1];
        int port = Integer.valueOf(args[2]);
        int dbIndex = Integer.valueOf(args[3]);

        Jedis jedis = new Jedis(host, port);

        int deletedKeysNumber = 0;
        if(dbIndex >= 0){
            deletedKeysNumber += deleteDataFromDB(jedis, keyPattern, dbIndex);
        } else {
            int dbSize = Integer.valueOf(jedis.configGet("databases").get(1));
            for(int i = 0; i < dbSize; i++){
                deletedKeysNumber += deleteDataFromDB(jedis, keyPattern, i);

        if(deletedKeysNumber == 0) {
            System.out.println("There is no keys with key pattern: " + keyPattern + " was found in database with host: " + host);

    private static int deleteDataFromDB(Jedis jedis, String keyPattern, int dbIndex) {;
        Set<String> keys = jedis.keys(keyPattern);
        for(String key : keys){
            System.out.println("The key: " + key + " has been deleted from database index: " + dbIndex);

        return keys.size();


Switch statement multiple cases in JavaScript

If you're using ES6, you can do this:

if (['afshin', 'saeed', 'larry'].includes(varName)) {
} else {
   alert('Default case');

Or for earlier versions of JavaScript, you can do this:

if (['afshin', 'saeed', 'larry'].indexOf(varName) !== -1) {
} else {
   alert('Default case');

Note that this won't work in older IE browsers, but you could patch things up fairly easily. See the question determine if string is in list in javascript for more information.

How can I convert a Timestamp into either Date or DateTime object?

java.sql.Timestamp is a subclass of java.util.Date. So, just upcast it.

Date dtStart = resultSet.getTimestamp("dtStart");
Date dtEnd = resultSet.getTimestamp("dtEnd");

Using SimpleDateFormat and creating Joda DateTime should be straightforward from this point on.

extract the date part from DateTime in C#

There is no way to "discard" the time component.

DateTime.Today is the same as:

DateTime d = DateTime.Now.Date;

If you only want to display only the date portion, simply do that - use ToString with the format string you need.

For example, using the standard format string "D" (long date format specifier):


Make Error 127 when running trying to compile code

Error 127 means one of two things:

  1. file not found: the path you're using is incorrect. double check that the program is actually in your $PATH, or in this case, the relative path is correct -- remember that the current working directory for a random terminal might not be the same for the IDE you're using. it might be better to just use an absolute path instead.
  2. ldso is not found: you're using a pre-compiled binary and it wants an interpreter that isn't on your system. maybe you're using an x86_64 (64-bit) distro, but the prebuilt is for x86 (32-bit). you can determine whether this is the answer by opening a terminal and attempting to execute it directly. or by running file -L on /bin/sh (to get your default/native format) and on the compiler itself (to see what format it is).

if the problem is (2), then you can solve it in a few diff ways:

  1. get a better binary. talk to the vendor that gave you the toolchain and ask them for one that doesn't suck.
  2. see if your distro can install the multilib set of files. most x86_64 64-bit distros allow you to install x86 32-bit libraries in parallel.
  3. build your own cross-compiler using something like crosstool-ng.
  4. you could switch between an x86_64 & x86 install, but that seems a bit drastic ;).

Subtracting Dates in Oracle - Number or Interval Datatype?

Ok, I don't normally answer my own questions but after a bit of tinkering, I have figured out definitively how Oracle stores the result of a DATE subtraction.

When you subtract 2 dates, the value is not a NUMBER datatype (as the Oracle 11.2 SQL Reference manual would have you believe). The internal datatype number of a DATE subtraction is 14, which is a non-documented internal datatype (NUMBER is internal datatype number 2). However, it is actually stored as 2 separate two's complement signed numbers, with the first 4 bytes used to represent the number of days and the last 4 bytes used to represent the number of seconds.

An example of a DATE subtraction resulting in a positive integer difference:

select date '2009-08-07' - date '2008-08-08' from dual;

Results in:


select dump(date '2009-08-07' - date '2008-08-08') from dual;

Typ=14 Len=8: 108,1,0,0,0,0,0,0

Recall that the result is represented as a 2 seperate two's complement signed 4 byte numbers. Since there are no decimals in this case (364 days and 0 hours exactly), the last 4 bytes are all 0s and can be ignored. For the first 4 bytes, because my CPU has a little-endian architecture, the bytes are reversed and should be read as 1,108 or 0x16c, which is decimal 364.

An example of a DATE subtraction resulting in a negative integer difference:

select date '1000-08-07' - date '2008-08-08' from dual;

Results in:


select dump(date '1000-08-07' - date '2008-08-08') from dual;

Typ=14 Len=8: 224,97,250,255,0,0,0,0

Again, since I am using a little-endian machine, the bytes are reversed and should be read as 255,250,97,224 which corresponds to 11111111 11111010 01100001 11011111. Now since this is in two's complement signed binary numeral encoding, we know that the number is negative because the leftmost binary digit is a 1. To convert this into a decimal number we would have to reverse the 2's complement (subtract 1 then do the one's complement) resulting in: 00000000 00000101 10011110 00100000 which equals -368160 as suspected.

An example of a DATE subtraction resulting in a decimal difference:

select to_date('08/AUG/2004 14:00:00', 'DD/MON/YYYY HH24:MI:SS'
 - to_date('08/AUG/2004 8:00:00', 'DD/MON/YYYY HH24:MI:SS') from dual;


The difference between those 2 dates is 0.25 days or 6 hours.

select dump(to_date('08/AUG/2004 14:00:00', 'DD/MON/YYYY HH24:MI:SS')
 - to_date('08/AUG/2004 8:00:00', 'DD/MON/YYYY HH24:MI:SS')) from dual;

Typ=14 Len=8: 0,0,0,0,96,84,0,0

Now this time, since the difference is 0 days and 6 hours, it is expected that the first 4 bytes are 0. For the last 4 bytes, we can reverse them (because CPU is little-endian) and get 84,96 = 01010100 01100000 base 2 = 21600 in decimal. Converting 21600 seconds to hours gives you 6 hours which is the difference which we expected.

Hope this helps anyone who was wondering how a DATE subtraction is actually stored.

You get the syntax error because the date math does not return a NUMBER, but it returns an INTERVAL:

SQL> SELECT DUMP(SYSDATE - start_date) from test;

Typ=14 Len=8: 188,10,0,0,223,65,1,0

You need to convert the number in your example into an INTERVAL first using the NUMTODSINTERVAL Function

For example:

SQL> SELECT (SYSDATE - start_date) DAY(5) TO SECOND from test;

+02748 22:50:04.000000

SQL> SELECT (SYSDATE - start_date) from test;


SQL> select NUMTODSINTERVAL(2748.9515, 'day') from dual;

+000002748 22:50:09.600000000


Based on the reverse cast with the NUMTODSINTERVAL() function, it appears some rounding is lost in translation.

How to prevent XSS with HTML/PHP?

Many frameworks help handle XSS in various ways. When rolling your own or if there's some XSS concern, we can leverage filter_input_array (available in PHP 5 >= 5.2.0, PHP 7.) I typically will add this snippet to my SessionController, because all calls go through there before any other controller interacts with the data. In this manner, all user input gets sanitized in 1 central location. If this is done at the beginning of a project or before your database is poisoned, you shouldn't have any issues at time of output...stops garbage in, garbage out.

/* Prevent XSS input */
$_GET   = filter_input_array(INPUT_GET, FILTER_SANITIZE_STRING);
/* I prefer not to use $_REQUEST...but for those who do: */
$_REQUEST = (array)$_POST + (array)$_GET + (array)$_REQUEST;

The above will remove ALL HTML & script tags. If you need a solution that allows safe tags, based on a whitelist, check out HTML Purifier.

If your database is already poisoned or you want to deal with XSS at time of output, OWASP recommends creating a custom wrapper function for echo, and using it EVERYWHERE you output user-supplied values:

//xss mitigation functions
function xssafe($data,$encoding='UTF-8')
   return htmlspecialchars($data,ENT_QUOTES | ENT_HTML401,$encoding);
function xecho($data)
   echo xssafe($data);

Representing null in JSON

There is only one way to represent null; that is with null.

console.log(null === null);   // true
console.log(null === true);   // false
console.log(null === false);  // false
console.log(null === 'null'); // false
console.log(null === "null"); // false
console.log(null === "");     // false
console.log(null === []);     // false
console.log(null === 0);      // false

That is to say; if any of the clients that consume your JSON representation use the === operator; it could be a problem for them.

no value

If you want to convey that you have an object whose attribute myCount has no value:

{ "myCount": null }

no attribute / missing attribute

What if you to convey that you have an object with no attributes:


Client code will try to access myCount and get undefined; it's not there.

empty collection

What if you to convey that you have an object with an attribute myCount that is an empty list:

{ "myCount": [] }

mysql_fetch_array() expects parameter 1 to be resource problem

$id = intval($_GET['id']);
$sql = "SELECT * FROM student WHERE IDNO=$id";
$result = mysql_query($sql) or trigger_error(mysql_error().$sql);

always do it this way and it will tell you what is wrong

How to open .mov format video in HTML video Tag?

You can use Controls attribute

<video id="sampleMovie" src="" controls></video>

setting request headers in selenium

check this out: chrome_options = Options()

chrome_options.add_argument('user-agent="Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36"')

Problem solved!

How to open specific tab of bootstrap nav tabs on click of a particuler link using jQuery?

Not sure if I understood correctly but here is snippet that I use to open links from Bootstrap tab menu:


<ul class="nav nav-tabs">
  <li class="active"><a href="#foo" data-toggle="tab">Foo</a></li>
  <li><a href="#bar" data-toggle="tab">Bar</a></li>
  <li><a href="baz.html" class="external">Baz</a></li>

<div class="tab-content">
  <div class="tab-pane active" id="foo">Foo</div>
  <div class="tab-pane" id="bar">Bar</div>


$('.nav a:not(".external")').click(function (e) {

How to put a div in center of browser using CSS?


<div id="something">... content ...</div>


#something {
    position: absolute;
    height: 200px;
    width: 400px;
    margin: -100px 0 0 -200px;
    top: 50%;
    left: 50%;

Spring Data JPA - "No Property Found for Type" Exception

If your project used Spring-Boot ,you can try to add this annotations at your


public class Application {.....

How do I return an int from EditText? (Android)

You can do this in 2 steps:

1: Change the input type(In your EditText field) in the layout file to android:inputType="number"

2: Use int a = Integer.parseInt(yourEditTextObject.getText().toString());

Move SQL Server 2008 database files to a new folder location

To add the privileges needed to the files add and grant right to the following local user: SQLServerMSSQLUser$COMPUTERNAME$INSTANCENAME, where COMPUTERNAME and INSTANCENAME has to be replaced with name of computer and MSSQL instance respectively.

How do I make an editable DIV look like a text field?

These look the same as their real counterparts in Safari, Chrome, and Firefox. They degrade gracefully and look OK in Opera and IE9, too.



textarea {
    height: 28px;
    width: 400px;

#textarea {
    -moz-appearance: textfield-multiline;
    -webkit-appearance: textarea;
    border: 1px solid gray;
    font: medium -moz-fixed;
    font: -webkit-small-control;
    height: 28px;
    overflow: auto;
    padding: 2px;
    resize: both;
    width: 400px;

input {
    margin-top: 5px;
    width: 400px;

#input {
    -moz-appearance: textfield;
    -webkit-appearance: textfield;
    background-color: white;
    background-color: -moz-field;
    border: 1px solid darkgray;
    box-shadow: 1px 1px 1px 0 lightgray inset;  
    font: -moz-field;
    font: -webkit-small-control;
    margin-top: 5px;
    padding: 2px 3px;
    width: 398px;    


<textarea>I am a textarea</textarea>
<div id="textarea" contenteditable>I look like textarea</div>

<input value="I am an input" />
<div id="input" contenteditable>I look like an input</div>


enter image description here

Get number of digits with JavaScript

it would be simple to get the length as


where NUM is the number to get the length for

Remove leading zeros from a number in Javascript

It is not clear why you want to do this. If you want to get the correct numerical value, you could use unary + [docs]:

value = +value;

If you just want to format the text, then regex could be better. It depends on the values you are dealing with I'd say. If you only have integers, then

input.value = +input.value;

is fine as well. Of course it also works for float values, but depending on how many digits you have after the point, converting it to a number and back to a string could (at least for displaying) remove some.

Selenium Webdriver: Entering text into text field

It might be the JavaScript check for some valid condition.
Two things you can perform a/c to your requirements:

  1. either check for the valid string-input in the text-box.
  2. or set a loop against that text box to enter the value until you post the form/request.
String barcode="0000000047166";

WebElement strLocator = driver.findElement(By.xpath("//*[@id='div-barcode']"));

read word by word from file in C++

If I may I could give you some new code for the same task, in my code you can create a so called 'document'(not really)and it is saved, and can be opened up again. It is also stored as a string file though(not a document). Here is the code:

#include "iostream"

#include "windows.h"

#include "string"

#include "fstream"

using namespace std;

int main() {

string saveload;

cout << "---------------------------" << endl;
cout << "|enter 'text' to write your document    |" << endl;
cout << "|enter 'open file' to open the document |" << endl;
cout << "----------------------------------------" << endl;
while (true){
    getline(cin, saveload);

    if (saveload == "open file"){
        string filenamet;
        cout << "file name? " << endl;
        getline(cin, filenamet, '*');
        ifstream loadFile;, ifstream::in);

        cout << "the text you entered was: ";

        while (loadFile.good()){

            cout << (char)loadFile.get();


        cout << "" << endl;



    if (saveload == "text") {
        string filename;
        cout << "file name: " << endl;
        getline(cin, filename,'*');
        string textToSave;
        cout << "Enter your text: " << endl;
        getline(cin, textToSave,'*');

        ofstream saveFile(filename);

        saveFile << textToSave;


return 0;

Just take this code and change it to serve your purpose. DREAM BIG,THINK BIG, DO BIG

What does it mean when MySQL is in the state "Sending data"?

This is quite a misleading status. It should be called "reading and filtering data".

This means that MySQL has some data stored on the disk (or in memory) which is yet to be read and sent over. It may be the table itself, an index, a temporary table, a sorted output etc.

If you have a 1M records table (without an index) of which you need only one record, MySQL will still output the status as "sending data" while scanning the table, despite the fact it has not sent anything yet.

Convert bytes to int?

Assuming you're on at least 3.2, there's a built in for this:

int.from_bytes( bytes, byteorder, *, signed=False )


The argument bytes must either be a bytes-like object or an iterable producing bytes.

The byteorder argument determines the byte order used to represent the integer. If byteorder is "big", the most significant byte is at the beginning of the byte array. If byteorder is "little", the most significant byte is at the end of the byte array. To request the native byte order of the host system, use sys.byteorder as the byte order value.

The signed argument indicates whether two’s complement is used to represent the integer.

## Examples:
int.from_bytes(b'\x00\x01', "big")                         # 1
int.from_bytes(b'\x00\x01', "little")                      # 256

int.from_bytes(b'\x00\x10', byteorder='little')            # 4096
int.from_bytes(b'\xfc\x00', byteorder='big', signed=True)  #-1024

How do I combine 2 select statements into one?

select t1.* from 
(select * from TABLE Where CCC='D' AND DDD='X') as t1,
(select * from TABLE Where CCC<>'D' AND DDD='X') as t2

Another way to do this!

Allowing Java to use an untrusted certificate for SSL/HTTPS connection

Another option is to get a ".pem" (public key) file for that particular server, and install it locally into the heart of your JRE's "cacerts" file (use the keytool helper application), then it will be able to download from that server without complaint, without compromising the entire SSL structure of your running JVM and enabling download from other unknown cert servers...

replace \n and \r\n with <br /> in java

This should work. You need to put in two slashes

str = str.replaceAll("(\\r\\n|\\n)", "<br />");

In this Reference, there is an example which shows

private final String REGEX = "\\d"; // a single digit

I have used two slashes in many of my projects and it seems to work fine!

Iterating through list of list in Python

This traverse generator function can be used to iterate over all the values:

def traverse(o, tree_types=(list, tuple)):
    if isinstance(o, tree_types):
        for value in o:
            for subvalue in traverse(value, tree_types):
                yield subvalue
        yield o

data = [(1,1,(1,1,(1,"1"))),(1,1,1),(1,),1,(1,(1,("1",)))]
print list(traverse(data))
# prints [1, 1, 1, 1, 1, '1', 1, 1, 1, 1, 1, 1, 1, '1']

for value in traverse(data):
    print repr(value)
# prints
# 1
# 1
# 1
# 1
# 1
# '1'
# 1
# 1
# 1
# 1
# 1
# 1
# 1
# '1'

Is a new line = \n OR \r\n?

If you are programming in PHP, it is useful to split lines by \n and then trim() each line (provided you don't care about whitespace) to give you a "clean" line regardless.

foreach($line in explode("\n", $data))
    $line = trim($line);

How do I import CSV file into a MySQL table?

I know that the question is old, But I would like to share this

I Used this method to import more than 100K records (~5MB) in 0.046sec

Here's how you do it:

INTO TABLE your_awesome_table  
(field_1,field_2 , field_3);

It is very important to include the last line , if you have more than one field i.e normally it skips the last field (MySQL 5.6.17)

(field_1,field_2 , field_3);

Then, assuming you have the first row as the title for your fields, you might want to include this line also


This is what it looks like if your file has a header row.

INTO TABLE your_awesome_table  
(field_1,field_2 , field_3);

Spring: Returning empty HTTP Responses with ResponseEntity<Void> doesn't work

Your method implementation is ambiguous, try the following , edited your code a little bit and used HttpStatus.NO_CONTENT i.e 204 No Content as in place of HttpStatus.OK

The server has fulfilled the request but does not need to return an entity-body, and might want to return updated metainformation. The response MAY include new or updated metainformation in the form of entity-headers, which if present SHOULD be associated with the requested variant.

Any value of T will be ignored for 204, but not for 404

  public ResponseEntity<?> taxonomyPackageExists( @PathVariable final String key ) {
            LOG.debug( "taxonomyPackageExists queried with key: {0}", key ); //$NON-NLS-1$
            final TaxonomyKey taxonomyKey = TaxonomyKey.fromString( key );
            LOG.debug( "Taxonomy key created: {0}", taxonomyKey ); //$NON-NLS-1$

            if ( this.xbrlInstanceValidator.taxonomyPackageExists( taxonomyKey ) ) {
                LOG.debug( "Taxonomy package with key: {0} exists.", taxonomyKey ); //$NON-NLS-1$
                 return new ResponseEntity<T>(HttpStatus.NO_CONTENT);
            } else {
               LOG.debug( "Taxonomy package with key: {0} does NOT exist.", taxonomyKey ); //$NON-NLS-1$
                return new ResponseEntity<T>( HttpStatus.NOT_FOUND );


Should I return EXIT_SUCCESS or 0 from main()?

Once you start writing code that can return a myriad of exit statuses, you start #define'ing all of them. In this case EXIT_SUCCESS makes sense in context of not being a "magic number". This makes your code more readable because every other exit code will be EXIT_SOMETHING. If you simply write a program that will return when it's done, return 0 is valid, and probably even cleaner because it suggests that there's no sophisticated return code structure.

SQL Developer with JDK (64 bit) cannot find JVM

I know that people may frown on a youtube example but this worked for me and I was getting the same issue

It will direct you to add the correct Environmental Variables for the JDK.

System Properties>Advanced>Environment Variables>Path> \sqldeveloper\jdk\bin AND \sqldeveloper\jdk\bin\server

validate a dropdownlist in mvc

I just can't believe that there are people still using ViewData/ViewBag in ASP.NET MVC 3 instead of having strongly typed views and view models:

public class MyViewModel
    public string CategoryId { get; set; }

    public IEnumerable<Category> Categories { get; set; }

and in your controller:

public class HomeController: Controller
    public ActionResult Index()
        var model = new MyViewModel
            Categories = Repository.GetCategories()
        return View(model);

    public ActionResult Index(MyViewModel model)
        if (!ModelState.IsValid)
            // there was a validation error =>
            // rebind categories and redisplay view
            model.Categories = Repository.GetCategories();
            return View(model);
        // At this stage the model is OK => do something with the selected category
        return RedirectToAction("Success");

and then in your strongly typed view:

    x => x.CategoryId, 
    new SelectList(Model.Categories, "ID", "CategoryName"), 
    "-- Please select a category --"
@Html.ValidationMessageFor(x => x.CategoryId)

Also if you want client side validation don't forget to reference the necessary scripts:

<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>

SQL Update with row_number()

With UpdateData  As

Merging two images in C#/.NET

After all this, I found a new easier method try this ..

It can join multiple photos together:

public static System.Drawing.Bitmap CombineBitmap(string[] files)
    //read all images into memory
    List<System.Drawing.Bitmap> images = new List<System.Drawing.Bitmap>();
    System.Drawing.Bitmap finalImage = null;

        int width = 0;
        int height = 0;

        foreach (string image in files)
            //create a Bitmap from the file and add it to the list
            System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(image);

            //update the size of the final bitmap
            width += bitmap.Width;
            height = bitmap.Height > height ? bitmap.Height : height;


        //create a bitmap to hold the combined image
        finalImage = new System.Drawing.Bitmap(width, height);

        //get a graphics object from the image so we can draw on it
        using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(finalImage))
            //set background color

            //go through each image and draw it on the final image
            int offset = 0;
            foreach (System.Drawing.Bitmap image in images)
                  new System.Drawing.Rectangle(offset, 0, image.Width, image.Height));
                offset += image.Width;

        return finalImage;
    catch (Exception ex)
        if (finalImage != null)

        throw ex;
        //clean up memory
        foreach (System.Drawing.Bitmap image in images)

Can we open pdf file using UIWebView on iOS?

NSString *folderName=[NSString stringWithFormat:@"/documents/%@",[tempDictLitrature objectForKey:@"folder"]];
NSString *fileName=[tempDictLitrature objectForKey:@"name"];
[self.navigationItem setTitle:fileName];
NSString *type=[tempDictLitrature objectForKey:@"type"];

NSString *path=[[NSBundle mainBundle]pathForResource:fileName ofType:type inDirectory:folderName];

NSURL *targetURL = [NSURL fileURLWithPath:path];
NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];
webView=[[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 1024, 730)];
[webView setBackgroundColor:[UIColor lightGrayColor]];
webView.scalesPageToFit = YES;

[[webView scrollView] setContentOffset:CGPointZero animated:YES];
[webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"window.scrollTo(0.0, 50.0)"]];
[webView loadRequest:request];
[self.view addSubview:webView];

importing pyspark in python shell

For Linux users, the following is the correct (and non-hard-coded) way of including the pyspark libaray in PYTHONPATH. Both PATH parts are necessary:

  1. The path to the pyspark Python module itself, and
  2. The path to the zipped library that that pyspark module relies on when imported

Notice below that the zipped library version is dynamically determined, so we do not hard-code it.

export PYTHONPATH=${SPARK_HOME}/python/:$(echo ${SPARK_HOME}/python/lib/py4j-*${PYTHONPATH}

How to efficiently concatenate strings in go

I do it using the following :-

package main

import (

func main (){
    concatenation:= strings.Join([]string{"a","b","c"},"") //where second parameter is a separator. 
    fmt.Println(concatenation) //abc


Big difference, TABLOCK will try to grab "shared" locks, and TABLOCKX exclusive locks.

If you are in a transaction and you grab an exclusive lock on a table, EG:


No other processes will be able to grab any locks on the table, meaning all queries attempting to talk to the table will be blocked until the transaction commits.

TABLOCK only grabs a shared lock, shared locks are released after a statement is executed if your transaction isolation is READ COMMITTED (default). If your isolation level is higher, for example: SERIALIZABLE, shared locks are held until the end of a transaction.

Shared locks are, hmmm, shared. Meaning 2 transactions can both read data from the table at the same time if they both hold a S or IS lock on the table (via TABLOCK). However, if transaction A holds a shared lock on a table, transaction B will not be able to grab an exclusive lock until all shared locks are released. Read about which locks are compatible with which at msdn.

Both hints cause the db to bypass taking more granular locks (like row or page level locks). In principle, more granular locks allow you better concurrency. So for example, one transaction could be updating row 100 in your table and another row 1000, at the same time from two transactions (it gets tricky with page locks, but lets skip that).

In general granular locks is what you want, but sometimes you may want to reduce db concurrency to increase performance of a particular operation and eliminate the chance of deadlocks.

In general you would not use TABLOCK or TABLOCKX unless you absolutely needed it for some edge case.

Create two blank lines in Markdown

I test on a lot of Markdown implementations. The non-breaking space ASCII character &nbsp; (followed by a blank line) would give a blank line. Repeating this pair would do the job. So far I haven't failed any.




For example:  













Detect IE version (prior to v9) in JavaScript

Return IE version or if not IE return false

function isIE () {
  var myNav = navigator.userAgent.toLowerCase();
  return (myNav.indexOf('msie') != -1) ? parseInt(myNav.split('msie')[1]) : false;


if (isIE () == 8) {
 // IE8 code
} else {
 // Other versions IE or not IE


if (isIE () && isIE () < 9) {
 // is IE version less than 9
} else {
 // is IE 9 and later or not IE


if (isIE()) {
 // is IE
} else {
 // Other browser

How to detect tableView cell touched or clicked in swift

This worked good for me:

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {_x000D_
        print("section: \(indexPath.section)")_x000D_
        print("row: \(indexPath.row)")_x000D_

The output should be:

section: 0
row: 0

How to change the session timeout in PHP?

Adding comment for anyone using Plesk having issues with any of the above as it was driving me crazy, setting session.gc_maxlifetime from your PHP script wont work as Plesk has it's own garbage collection script run from cron.

I used the solution posted on the link below of moving the cron job from hourly to daily to avoid this issue, then the top answer above should work:

mv /etc/cron.hourly/plesk-php-cleanuper /etc/cron.daily/

How to increment a JavaScript variable using a button press event

Had a similar problem. Needed to append as many text inputs as the user wanted, to a form. The functionality of it using jQuery was the answer to the question:

<div id='inputdiv'>
<button id='mybutton'>add an input</button>

var thecounter=0; //declare and initialize the counter outside of the function
$('#mybutton').on('click', function(){
$('#inputdiv').append('<input id="input'+thecounter+'" type="text/>);

Adding the count to each new input id resulted in unique ids which lets you get all the values using the jQuery serialize() function.

trying to align html button at the center of the my page

Here is the solution as asked

<button type="button" style="background-color:yellow;margin:auto;display:block">mybuttonname</button>

Resize HTML5 canvas to fit window

Unless you want the canvas to upscale your image data automatically (that's what James Black's answer talks about, but it won't look pretty), you have to resize it yourself and redraw the image. Centering a canvas

Tomcat: How to find out running tomcat version

run on terminal of the Unix server

w3m http://localhost:8080/

to quit press q and next y

Indenting code in Sublime text 2?

No one seems to love mac re-indentation, So here How I do it:

   { "keys": ["command+shift+i"], "command": "reindent"}

In Preferences > Key Binding - User

One more extra tip: add

{ "keys": ["command+0"], "command": "focus_side_bar" }

to have sidebar file tree view navigation using keyboard.

Note: Add , at the end of each {}, if you have more than one {} set of objects

Launching Google Maps Directions via an intent on Android

if you know point A, point B (and whatever features or tracks in between) you can use a KML file along with your intent.

String kmlWebAddress = "";
String uri = String.format(Locale.ENGLISH, "geo:0,0?q=%s",kmlWebAddress);
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(uri));

for more info, see this SO answer

NOTE: this example uses a sample file that (as of mar13) is still online. if it has gone offline, find a kml file online and change your url

File Upload without Form

Step 1: Create HTML Page where to place the HTML Code.

Step 2: In the HTML Code Page Bottom(footer)Create Javascript: and put Jquery Code in Script tag.

Step 3: Create PHP File and php code copy past. after Jquery Code in $.ajax Code url apply which one on your php file name.


//$(document).on("change", "#avatar", function() {   // If you want to upload without a submit button 
$(document).on("click", "#upload", function() {
  var file_data = $("#avatar").prop("files")[0]; // Getting the properties of file from file field
  var form_data = new FormData(); // Creating object of FormData class
  form_data.append("file", file_data) // Appending parameter named file with properties of file_field to form_data
  form_data.append("user_id", 123) // Adding extra parameters to form_data
    url: "/upload_avatar", // Upload Script
    dataType: 'script',
    cache: false,
    contentType: false,
    processData: false,
    data: form_data, // Setting the data attribute of ajax with file_data
    type: 'post',
    success: function(data) {
      // Do something after Ajax completes 


<input id="avatar" type="file" name="avatar" />
<button id="upload" value="Upload" />



how to make a full screen div, and prevent size to be changed by content?

Here is my Solution, I think will better to use vh (viewport height) and vw for (viewport width), units regarding to the height and width of the current viewport

function myFunction() {
  var element = document.getElementById("main");
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  background-color: #333;
  margin: 0; 
  padding: 0; 
<div id="main"></div>
<button onclick="myFunction()">Try it</button>

Checking if sys.argv[x] is defined

Another way I haven't seen listed yet is to set your sentinel value ahead of time. This method takes advantage of Python's lazy evaluation, in which you don't always have to provide an else statement. Example:

startingpoint = 'blah'
if len(sys.argv) >= 2:
  startingpoint = sys.argv[1]

Or if you're going syntax CRAZY you could use Python's ternary operator:

startingpoint = sys.argv[1] if len(sys.argv) >= 2 else 'blah'

String to char array Java

A string to char array is as simple as

String str = "someString"; 
char[] charArray = str.toCharArray();

Can you explain a little more on what you are trying to do?

* Update *

if I am understanding your new comment, you can use a byte array and example is provided.

byte[] bytes = ByteBuffer.allocate(4).putInt(1695609641).array();

for (byte b : bytes) {
   System.out.format("0x%x ", b);

With the following output

0x65 0x10 0xf3 0x29

macro for Hide rows in excel 2010

Well, you're on the right path, Benno!

There are some tips regarding VBA programming that might help you out.

  1. Use always explicit references to the sheet you want to interact with. Otherwise, Excel may 'assume' your code applies to the active sheet and eventually you'll see it screws your spreadsheet up.

  2. As lionz mentioned, get in touch with the native methods Excel offers. You might use them on most of your tricks.

  3. Explicitly declare your variables... they'll show the list of methods each object offers in VBA. It might save your time digging on the internet.

Now, let's have a draft code...

Remember this code must be within the Excel Sheet object, as explained by lionz. It only applies to Sheet 2, is up to you to adapt it to both Sheet 2 and Sheet 3 in the way you prefer.

Hope it helps!

Private Sub Worksheet_Change(ByVal Target As Range)

    Dim oSheet As Excel.Worksheet

    'We only want to do something if the changed cell is B6, right?
    If Target.Address = "$B$6" Then

        'Checks if it's a number...
        If IsNumeric(Target.Value) Then

            'Let's avoid values out of your bonds, correct?
            If Target.Value > 0 And Target.Value < 51 Then

                'Let's assign the worksheet we'll show / hide rows to one variable and then
                '   use only the reference to the variable itself instead of the sheet name.
                '   It's safer.

                'You can alternatively replace 'sheet 2' by 2 (without quotes) which will represent
                '   the sheet index within the workbook
                Set oSheet = ActiveWorkbook.Sheets("Sheet 2")

                'We'll unhide before hide, to ensure we hide the correct ones
                oSheet.Range("A7:A56").EntireRow.Hidden = False

                oSheet.Range("A" & Target.Value + 7 & ":A56").EntireRow.Hidden = True

            End If

        End If

    End If

End Sub

New xampp security concept: Access Forbidden Error 403 - Windows 7 - phpMyAdmin

Try to reinstall new version of XAMPP. Find "<Directory "C:/xampp/php">" and then change to something like this

<Directory "C:/xampp/php">
    AllowOverride AuthConfig Limit
    Order allow,deny
    Allow from all
    Require all granted

SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Name or service not known

We're using symfony with doctrine and we are in the process of automating deployment. I got this error when I simply hadn't provided the correct db creds in parameters.yml (I was running doctrine:migrations:migrate)

This thread has sent me on a bit of a wild goose chase, so I'm leaving this here so others might not have to.

Best way to "negate" an instanceof

If you find it more understandable, you can do something like this with Java 8 :

public static final Predicate<Object> isInstanceOfTheClass = 
    objectToTest -> objectToTest instanceof TheClass;

public static final Predicate<Object> isNotInstanceOfTheClass = 
    isInstanceOfTheClass.negate(); // or objectToTest -> !(objectToTest instanceof TheClass)

if (isNotInstanceOfTheClass.test(myObject)) {
    // do something

Save internal file in my own internal folder in Android

The answer of Mintir4 is fine, I would also do the following to load the file.

FileInputStream fis = myContext.openFileInput(fn);
BufferedReader r = new BufferedReader(new InputStreamReader(fis));
String s = "";

while ((s = r.readLine()) != null) {
    txt += s;


How can I replace a newline (\n) using sed?

To remove empty lines:

sed -n "s/^$//;t;p;"

Error: Specified cast is not valid. (SqlManagerUI)

This would also happen when you are trying to restore a newer version backup in a older SQL database. For example when you try to restore a DB backup that is created in 2012 with 110 compatibility and you are trying to restore it in 2008 R2.

What is the difference between Integer and int in Java?

To optimize the Java code runtime, int primitive type(s) has been added including float, bool etc. but they come along with there wrapper classes so that if needed you can convert and use them as standard Java object along with many utility that comes as their member functions (such as Integer.parseInt("1")).

Get data from fs.readFile

This line will work,

const content = fs.readFileSync('./Index.html', 'utf8');

What causes this error? "Runtime error 380: Invalid property value"

Looks like the answers above are for when you are writing and compiling a program, but I'm using a Vendor's software, Catalog.exe, part of the Voyager card catalog by "Ex Libris" and I'm getting the error as well:


I have two Windows 7 32-bit machines. The newer one is giving me the error but on the older one it runs fine. I have done a lot of research with Google and here are some of the things I've found that people are saying related to this issue. Maybe one of these things will help fix the error for you, although they didn't work for me:

From what others are saying (like David M) I think it could be related to the MSVBM60.DLL library - but it appears that on both of my computers this file is the exact same (same version, size, date, etc).

Since that file wasn't different I tried to find what other (dll) files the application could be using, so I launched Process Explorer by Sysinternals and took a look at the application (it loads and then crashes when you tell it to "connect"), and the screenshots below are what I found.




Now, I'm not a Windows / VB programmer, just a power user, and so I'm about at the end of my knowledge for what to do. I've talked to the software vendor and they recommend reinstalling Windows. That will probably work, but it just bugs me that this program can run on Windows 7, but something on this particular system is causing errors. Finally, this is an image that has been deployed on multiple machines already and so while re-installing Windows once is not a big deal it would save me some serious time if I could figure out a fix or workaround.

CSS hide scroll bar if not needed

.container {overflow:auto;} will do the trick. If you want to control specific direction, you should set auto for that specific axis. A.E.

.container {overflow-y:auto;} .container {overflow-x:hidden;}

The above code will hide any overflow in the x-axis and generate a scroll-bar when needed on the y-axis.But you have to make sure that you content default height smaller than the container height; if not, the scroll-bar will not be hidden.

How to set socket timeout in C when making multiple connections?

connect timeout has to be handled with a non-blocking socket (GNU LibC documentation on connect). You get connect to return immediately and then use select to wait with a timeout for the connection to complete.

This is also explained here : Operation now in progress error on connect( function) error.

int wait_on_sock(int sock, long timeout, int r, int w)
    struct timeval tv = {0,0};
    fd_set fdset;
    fd_set *rfds, *wfds;
    int n, so_error;
    unsigned so_len;

    FD_ZERO (&fdset);
    FD_SET  (sock, &fdset);
    tv.tv_sec = timeout;
    tv.tv_usec = 0;

    TRACES ("wait in progress tv={%ld,%ld} ...\n",
            tv.tv_sec, tv.tv_usec);

    if (r) rfds = &fdset; else rfds = NULL;
    if (w) wfds = &fdset; else wfds = NULL;

    TEMP_FAILURE_RETRY (n = select (sock+1, rfds, wfds, NULL, &tv));
    switch (n) {
    case 0:
        ERROR ("wait timed out\n");
        return -errno;
    case -1:
        ERROR_SYS ("error during wait\n");
        return -errno;
        // select tell us that sock is ready, test it
        so_len = sizeof(so_error);
        so_error = 0;
        getsockopt (sock, SOL_SOCKET, SO_ERROR, &so_error, &so_len);
        if (so_error == 0)
            return 0;
        errno = so_error;
        ERROR_SYS ("wait failed\n");
        return -errno;

Right way to reverse a pandas DataFrame?

What is the right way to reverse a pandas DataFrame?

TL;DR: df[::-1]

This is objectively IMO the best method for reversing a DataFrame, because it is a ONE step operation, also very readable (assuming familiarity with slice notation).

Long Version

I've found the ol' slicing trick df[::-1] (or the equivalent df.loc[::-1]1) to be the most concise and idiomatic way of reversing a DataFrame. This mirrors the python list reversal syntax lst[::-1] and is clear in its intent. With the loc syntax, you are also able to slice columns if required, so it is a bit more flexible.

Some points to consider while handling the index:

  • "what if I want to reverse the index as well?"

    • you're already done. df[::-1] reverses both the index and values.
  • "what if I want to drop the index from the result?"

  • "what if I want to keep the index untouched (IOW, only reverse the data, not the index)?"

    • this is somewhat unconventional because it implies the index isn't really relevant to the data. Perhaps consider removing it entirely? Although what you're asking for can technically be achieved using either df[:] = df[::-1] which creates an in-place update to df, or df.loc[::-1].set_index(df.index), which returns a copy.

1: df.loc[::-1] and df.iloc[::-1] are equivalent since the slicing syntax remains the same, whether you're reversing by position (iloc) or label (loc).

The Proof is in the Pudding

enter image description here

X-axis represents the dataset size. Y-axis represents time taken to reverse. No method scales as well as the slicing trick, it's all the way at the bottom of the graph. Benchmarking code for reference, plots generated using perfplot.

Comments on other solutions

  • df.reindex(index=df.index[::-1]) is clearly a popular solution, but on first glance, how obvious is it to an unfamiliar reader that this code is "reversing a DataFrame"? Additionally, this is reversing the index, then using that intermediate result to reindex, so this is essentially a TWO step operation (when it could've been just one).

  • df.sort_index(ascending=False) may work in most cases where you have a simple range index, but this assumes your index was sorted in ascending order and so doesn't generalize well.

  • PLEASE do not use iterrows. I see some options suggesting iterating in reverse. Whatever your use case, there is likely a vectorized method available, but if there isn't then you can use something a little more reasonable such as list comprehensions. See How to iterate over rows in a DataFrame in Pandas for more detail on why iterrows is an antipattern.

importing go files in same folder

I just wanted something really basic to move some files out of the main folder, like user2889485's reply, but his specific answer didnt work for me. I didnt care if they were in the same package or not.

My GOPATH workspace is c:\work\go and under that I have

/src/pg/main.go      (package main)
/src/pg/dbtypes.go   (pakage dbtypes)

in main.go I import "/pg/dbtypes"

More elegant "ps aux | grep -v grep"

You could use preg_split instead of explode and split on [ ]+ (one or more spaces). But I think in this case you could go with preg_match_all and capturing:

preg_match_all('/[ ]php[ ]+\S+[ ]+(\S+)/', $input, $matches);
$result = $matches[1];

The pattern matches a space, php, more spaces, a string of non-spaces (the path), more spaces, and then captures the next string of non-spaces. The first space is mostly to ensure that you don't match php as part of a user name but really only as a command.

An alternative to capturing is the "keep" feature of PCRE. If you use \K in the pattern, everything before it is discarded in the match:

preg_match_all('/[ ]php[ ]+\S+[ ]+\K\S+/', $input, $matches);
$result = $matches[0];

I would use preg_match(). I do something similar for many of my system management scripts. Here is an example:

$test = "user     12052  0.2  0.1 137184 13056 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust1 cron
user     12054  0.2  0.1 137184 13064 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust3 cron
user     12055  0.6  0.1 137844 14220 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust4 cron
user     12057  0.2  0.1 137184 13052 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust89 cron
user     12058  0.2  0.1 137184 13052 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust435 cron
user     12059  0.3  0.1 135112 13000 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust16 cron
root     12068  0.0  0.0 106088  1164 pts/1    S+   10:00   0:00 sh -c ps aux | grep utilities > /home/user/public_html/logs/dashboard/currentlyPosting.txt
root     12070  0.0  0.0 103240   828 pts/1    R+   10:00   0:00 grep utilities";

$lines = explode("\n", $test);

foreach($lines as $line){
        if(preg_match("/.php[\s+](cust[\d]+)[\s+]cron/i", $line, $matches)){


The above prints:

    [0] => .php cust1 cron
    [1] => cust1
    [0] => .php cust3 cron
    [1] => cust3
    [0] => .php cust4 cron
    [1] => cust4
    [0] => .php cust89 cron
    [1] => cust89
    [0] => .php cust435 cron
    [1] => cust435
    [0] => .php cust16 cron
    [1] => cust16

You can set $test to equal the output from exec. the values you are looking for would be in the if statement under the foreach. $matches[1] will have the custx value.

Negative weights using Dijkstra's Algorithm

Consider what happens if you go back and forth between B and C...voila

(relevant only if the graph is not directed)

Edited: I believe the problem has to do with the fact that the path with AC* can only be better than AB with the existence of negative weight edges, so it doesn't matter where you go after AC, with the assumption of non-negative weight edges it is impossible to find a path better than AB once you chose to reach B after going AC.

Alternative to the HTML Bold tag

You can make text or words Bold with using <b>Text</b> tag.

You can also use <strong>Text</strong> tag

Head tags <h1>, <h2>, <h3>, ... are default bolded tags and make your text Bold by default unless you change their style with CSS

Above tags was available in HTML but if you like to change the style with CSS you can use


How to compile a 64-bit application using Visual C++ 2010 Express?

Programming in a 64-bit environment is quite different than 32-bit environment. Code generated has totally different assembly constitution in 32 & 64-bit code, even the protocols of communicating with functions change. So you can't generate 64-bit code using 32-bit compiler.

You might want to see an article on Microsoft's web site about targeting a 64-bit target but using a 32-bit development machine.

Optional Parameters in Web Api Attribute Routing

Converting my comment into an answer to complement @Kiran Chala's answer as it seems helpful for the audiences-

When we mark a parameter as optional in the action uri using ? character then we must provide default values to the parameters in the method signature as shown below:

MyMethod(string name = "someDefaultValue", int? Id = null)

How to list all methods for an object in Ruby?

If You are looking list of methods which respond by an instance (in your case @current_user). According to ruby documentation methods

Returns a list of the names of public and protected methods of obj. This will include all the methods accessible in obj's ancestors. If the optional parameter is false, it returns an array of obj's public and protected singleton methods, the array will not include methods in modules included in obj.

@current_user.methods(false) #only public and protected singleton methods and also array will not include methods in modules included in @current_user class or parent of it.

Alternatively, You can also check that a method is callable on an object or not?.


If you don't want parent class methods then just subtract the parent class methods from it.

@current_user.methods - #methods that are available to @current_user instance.

Encode html entities in javascript

You can use regex to replace any character in a given unicode range with its html entity equivalent. The code would look something like this:

var encodedStr = rawStr.replace(/[\u00A0-\u9999<>\&]/g, function(i) {
   return '&#'+i.charCodeAt(0)+';';

This code will replace all characters in the given range (unicode 00A0 - 9999, as well as ampersand, greater & less than) with their html entity equivalents, which is simply &#nnn; where nnn is the unicode value we get from charCodeAt.

See it in action here: (this example uses jQuery for element selectors used in the example. The base code itself, above, does not use jQuery)

Making these conversions does not solve all the problems -- make sure you're using UTF8 character encoding, make sure your database is storing the strings in UTF8. You still may see instances where the characters do not display correctly, depending on system font configuration and other issues out of your control.


Add views below toolbar in CoordinatorLayout

To use collapsing top ToolBar or using ScrollFlags of your own choice we can do this way:From Material Design get rid of FrameLayout

<?xml version="1.0" encoding="utf-8"?>





                android:src="@drawable/ic_arrow_back" />

                android:textStyle="bold" />





Inserting multiple rows in a single SQL query?

INSERT statements that use VALUES syntax can insert multiple rows. To do this, include multiple lists of column values, each enclosed within parentheses and separated by commas.


INSERT INTO tbl_name (a,b,c) VALUES(1,2,3),(4,5,6),(7,8,9);

Check file size before upload

Client side Upload Canceling

On modern browsers (FF >= 3.6, Chrome >= 19.0, Opera >= 12.0, and buggy on Safari), you can use the HTML5 File API. When the value of a file input changes, this API will allow you to check whether the file size is within your requirements. Of course, this, as well as MAX_FILE_SIZE, can be tampered with so always use server side validation.

<form method="post" enctype="multipart/form-data" action="upload.php">
    <input type="file" name="file" id="file" />
    <input type="submit" name="submit" value="Submit" />

document.forms[0].addEventListener('submit', function( evt ) {
    var file = document.getElementById('file').files[0];

    if(file && file.size < 10485760) { // 10 MB (this size is in bytes)
        //Submit form        
    } else {
        //Prevent default and display error
}, false);

Server Side Upload Canceling

On the server side, it is impossible to stop an upload from happening from PHP because once PHP has been invoked the upload has already completed. If you are trying to save bandwidth, you can deny uploads from the server side with the ini setting upload_max_filesize. The trouble with this is this applies to all uploads so you'll have to pick something liberal that works for all of your uploads. The use of MAX_FILE_SIZE has been discussed in other answers. I suggest reading the manual on it. Do know that it, along with anything else client side (including the javascript check), can be tampered with so you should always have server side (PHP) validation.

PHP Validation

On the server side you should validate that the file is within the size restrictions (because everything up to this point except for the INI setting could be tampered with). You can use the $_FILES array to find out the upload size. (Docs on the contents of $_FILES can be found below the MAX_FILE_SIZE docs)


if(isset($_FILES['file'])) {
    if($_FILES['file']['size'] > 10485760) { //10 MB (size is also in bytes)
        // File too big
    } else {
        // File within size restrictions

Image inside div has extra space below the image

Quick fix:

To remove the gap under the image, you can:

  • Set the vertical-align property of the image to vertical-align: bottom; vertical-align: top; or vertical-align: middle;
  • Set the display property of the image to display:block;

See the following code for a live demo:

#vAlign img {_x000D_
  vertical-align :bottom;_x000D_
#block img{_x000D_
div {border: 1px solid red;width:100px;}_x000D_
img {width:100px;}
<p>No fix:</p>_x000D_
<div><img src="" /></div>_x000D_
<p>With vertical-align:bottom; on image:</p>_x000D_
<div id="vAlign"><img src="" /></div>_x000D_
<p>With display:block; on image:</p>_x000D_
<div id="block"><img src="" /></div>

Explanation: why is there a gap under the image?

The gap or extra space under the image isn't a bug or issue, it is the default behaviour. The root cause is that images are replaced elements (see MDN replaced elements). This allows them to "act like image" and have their own intrinsic dimensions, aspect ratio....
Browsers compute their display property to inline but they give them a special behaviour which makes them closer to inline-block elements (as you can vertical align them, give them a height, top/bottom margin and padding, transforms ...).

This also means that:

<img> has no baseline, so when images are used in an inline formatting context with vertical-align: baseline, the bottom of the image will be placed on the text baseline.
(source: MDN, emphasis mine)

As browsers by default compute the vertical-align property to baseline, this is the default behaviour. The following image shows where the baseline is located on text:

Location of the baseline on text (Image source)

Baseline aligned elements need to keep space for the descenders that extend below the baseline (like j, p, g ...) as you can see in the above image. In this configuration, the bottom of the image is aligned on the baseline as you can see in this example:

div{border:1px solid red;font-size:30px;}_x000D_
  <img src="" />jpq are letters with descender_x000D_

This is why the default behaviour of the <img> tag creates a gap at the bottom of it's container and why changing the vertical-align property or the display property removes it as in the following demo:

div {width: 100px;border: 1px solid red;}_x000D_
img {width: 100px;height: auto;}_x000D_
.block img{_x000D_
.bottom img{_x000D_
  <img src="" />_x000D_
<p>With display:block;</p>_x000D_
<div class="block">_x000D_
  <img src="" />_x000D_
<p>With vertical-align:bottom;</p>_x000D_
<div class="bottom">_x000D_
  <img src="" />_x000D_

Using JQuery hover with HTML image map

This question is old but I wanted to add an alternative to the accepted answer which didn't exist at the time.

Image Mapster is a jQuery plugin that I wrote to solve some of the shortcomings of Map Hilight (and it was initially an extension of that plugin, though it's since been almost completely rewritten). Initially, this was just the ability to maintain selection state for areas, fix browser compatibility problems. Since its initial release a few months ago, though, I have added a lot of features including the ability to use an alternate image as the source for the highlights.

It also has the ability to identify areas as "masks," meaning you can create areas with "holes", and additionally create complex groupings of areas. For example, area A could cause another area B to be highlighted, but area B itself would not respond to mouse events.

There are a few examples on the web site that show most of the features. The github repository also has more examples and complete documentation.

How can I conditionally require form inputs with AngularJS?

In AngularJS (version 1.x), there is a build-in directive ngRequired

<input type='email'
       placeholder='[email protected]'
       ng-required='!' />

<input type='text'
       placeholder='(xxx) xxx-xxxx'
       ng-required='!' /> 

In Angular2 or above

<input type='email'
       placeholder='[email protected]'
       [required]='!' />

<input type='text'
       placeholder='(xxx) xxx-xxxx'
       [required]='!' /> 

How do I get multiple subplots in matplotlib?

Iterating through all subplots sequentially:

fig, axes = plt.subplots(nrows, ncols)

for ax in axes.flatten():

Accessing a specific index:

for row in range(nrows):
    for col in range(ncols):
        axes[row,col].plot(x[row], y[col])

How to remove padding around buttons in Android?

That's not padding, it's the shadow around the button in its background drawable. Create your own background and it will disappear.

AngularJS : Difference between the $observe and $watch methods

I think this is pretty obvious :

  • $observe is used in linking function of directives.
  • $watch is used on scope to watch any changing in its values.

Keep in mind : both the function has two arguments,

$observe/$watch(value : string, callback : function);
  • value : is always a string reference to the watched element (the name of a scope's variable or the name of the directive's attribute to be watched)
  • callback : the function to be executed of the form function (oldValue, newValue)

I have made a plunker, so you can actually get a grasp on both their utilization. I have used the Chameleon analogy as to make it easier to picture.

iOS 8 removed "minimal-ui" viewport property, are there other "soft fullscreen" solutions?

It IS possible, using something like the below example that I put together with the help of work from ( that didn't quite work on iOS 11:

Here's the modified code that works on iOS 11.03, please comment if it worked for you.

The key is adding some size to BODY so the browser can scroll, ex: height: calc(100% + 40px);

Full sample below & link to view in your browser (please test!)

<html lang="en">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CodeHots iOS WebApp Minimal UI via Scroll Test</title>

        html, body {
            height: 100%;
        html {
            background-color: red;
        body {
            background-color: blue;
            /* important to allow page to scroll */
            height: calc(100% + 40px);
            margin: 0;
        div.header {
            width: 100%;
            height: 40px;
            background-color: green;
            overflow: hidden;
        div.content {
            height: 100%;
            height: calc(100% - 40px);
            width: 100%;
            background-color: purple;
            overflow: hidden;
        div.cover {
            position: absolute;
            top: 0;
            left: 0;
            z-index: 100;
            width: 100%;
            height: 100%;
            overflow: hidden;
            background-color: rgba(0, 0, 0, 0.5);
            color: #fff;
            display: none;
        @media screen and (width: 320px) {
            html {
                height: calc(100% + 72px);
            div.cover {
                display: block;
        var timeout;

        function interceptTouchMove(){
            // and disable the touchmove features 
            window.addEventListener("touchmove", (event)=>{
                if (!'scrollable')) {
                    // no more scrolling
            }, false); 

        function scrollDetect(event){
            // wait for the result to settle
            if( timeout ) clearTimeout(timeout);

            timeout = setTimeout(function() {
                console.log( 'scrolled up detected..' );
                if (window.scrollY > 35) {
                    console.log( ' .. moved up enough to go into minimal UI mode. cover off and locking touchmove!');
                    // hide the fixed scroll-cover
                    var cover = document.querySelector('div.cover');
           = 'none';

                    // push back down to designated start-point. (as it sometimes overscrolls (this is jQuery implementation I used))
                    window.scrollY = 40;

                    // and disable the touchmove features 

                    // turn off scroll checker
                    window.removeEventListener('scroll', scrollDetect );                
            }, 200);            

        // listen to scroll to know when in minimal-ui mode.
        window.addEventListener('scroll', scrollDetect, false );

    <div class="header">
        <p>header zone</p>
    <div class="content">
    <div class="cover">
        <p>scroll to soft fullscreen</p>


Full example link here:

Truncate/round whole number in JavaScript?

Convert the number to a string and throw away everything after the decimal.

trunc = function(n) { return Number(String(n).replace(/\..*/, "")) }

trunc(-1.5) === -1

trunc(1.5) === 1

Edit 2013-07-10

As pointed out by minitech and on second thought the string method does seem a bit excessive. So comparing the various methods listed here and elsewhere:

function trunc1(n){ return parseInt(n, 10); }
function trunc2(n){ return n - n % 1; }
function trunc3(n) { return Math[n > 0 ? "floor" : "ceil"](n); }
function trunc4(n) { return Number(String(n).replace(/\..*/, "")); }

function getRandomNumber() { return Math.random() * 10; }

function test(func, desc) {
    var t1, t2;
    var ave = 0;
    for (var k = 0; k < 10; k++) {
        t1 = new Date().getTime();
        for (var i = 0; i < 1000000; i++) {
        t2 = new Date().getTime();
        ave += t2 - t1;
    } + " => " + (ave / 10));

test("trunc1", "parseInt");
test("trunc2", "mod");
test("trunc3", "Math");
test("trunc4", "String");

The results, which may vary based on the hardware, are as follows:

parseInt => 258.7
mod      => 246.2
Math     => 243.8
String   => 1373.1

The Math.floor / ceil method being marginally faster than parseInt and mod. String does perform poorly compared to the other methods.

How are people unit testing with Entity Framework 6, should you bother?

I have fumbled around sometime to reach these considerations:

1- If my application access the database, why the test should not? What if there is something wrong with data access? The tests must know it beforehand and alert myself about the problem.

2- The Repository Pattern is somewhat hard and time consuming.

So I came up with this approach, that I don't think is the best, but fulfilled my expectations:

Use TransactionScope in the tests methods to avoid changes in the database.

To do it it's necessary:

1- Install the EntityFramework into the Test Project. 2- Put the connection string into the app.config file of Test Project. 3- Reference the dll System.Transactions in Test Project.

The unique side effect is that identity seed will increment when trying to insert, even when the transaction is aborted. But since the tests are made against a development database, this should be no problem.

Sample code:

public class NameValueTest
    public void Edit()
        NameValueController controller = new NameValueController();

        using(var ts = new TransactionScope()) {
            Assert.IsNotNull(controller.Edit(new Models.NameValue()
                NameValueId = 1,
                name1 = "1",
                name2 = "2",
                name3 = "3",
                name4 = "4"

            //no complete, automatically abort

    public void Create()
        NameValueController controller = new NameValueController();

        using (var ts = new TransactionScope())
            Assert.IsNotNull(controller.Create(new Models.NameValue()
                name1 = "1",
                name2 = "2",
                name3 = "3",
                name4 = "4"

            //no complete, automatically abort

R * not meaningful for factors ERROR

new[,2] is a factor, not a numeric vector. Transform it first

new$MY_NEW_COLUMN <-as.numeric(as.character(new[,2])) * 5

Show Error on the tip of the Edit Text Android

Using Kotlin Language,


 login_ID.setOnClickListener {
                email_address_Id.error = "Please Enter Email Address"
                Password_ID.error = "Please Enter Password"

How to load up CSS files using Javascript?

Using jQuery:

$('head').append('<link rel="stylesheet" href="stylesheetfile.css" type="text/css" />');

go get results in 'terminal prompts disabled' error for github private repo

1st -- go get will refuse to authenticate on the command line. So you need to cache the credentials in git. Because I use osx I can use osxkeychain credential helper.

2nd For me, I have 2FA enabled and thus could not use my password to auth. Instead I had to generate a personal access token to use in place of the password.

  1. setup osxkeychain credential helper
  2. If using TFA instead of using your password, generate a personal access token with repo scope
  3. git clone a private repo just to make it cache the password git clone and used your username for username and the generated personal access token for password.
  4. Removed the just cloned repo and retest to ensure creds were cached -- git clone and this time wasnt asked for creds.

    1. go get will work with any repos that the personal access token can access. You may have to repeat the steps with other accounts / tokens as permissions vary.

Razor View Without Layout


    Layout = null;

to get rid of the layout specified in _ViewStart.

Apply style ONLY on IE

@media screen and (-ms-high-contrast: active), (-ms-high-contrast: none) {
   #myElement {
        /* Enter your style code */

Explanation: It is a Microsoft-specific media query. Using -ms-high-contrast property specific to Microsoft IE, it will only be parsed in Internet Explorer 10 or greater. I have used both the valid values of the media query, so it will be parsed by IE only, whether the user has high contrast enabled or not.

Run a single migration file

Looks like at least in the latest Rails release (5.2 at the time of writing) there is one more way of filtering the migrations being ran. One can pass a filter in a SCOPE environment variable which would be then used to select migration files.

Assuming you have two migration files 1_add_foos.rb and 2_add_foos.run_this_one.rb running

SCOPE=run_this_one rails db:migrate:up

will select and run only 2_add_foos.run_this_one.rb. Keep in mind that all migration files matching the scope will be ran.

I forgot the password I entered during postgres installation

What I did to resolve the same problem was:

Open pg_hba.conf file with gedit editor from the terminal:

sudo gedit /etc/postgresql/9.5/main/pg_hba.conf

It will ask for password. Enter your admin login password. This will open gedit with the file. Paste the following line:

host  all   all  trust

just below -

# Database administrative login by Unix domain socket

Save and close it. Close the terminal and open it again and run this command:

psql -U postgres

You will now enter the psql console. Now change the password by entering this:

ALTER USER [your prefered user name] with password '[desired password]';

If it says user does not exist then instead of ALTER use CREATE.

Lastly, remove that certain line you pasted in pg_hba and save it.

Spring RestTemplate timeout

This question is the first link for a Spring Boot search, therefore, would be great to put here the solution recommended in the official documentation. Spring Boot has its own convenience bean RestTemplateBuilder:

public RestTemplate restTemplate(
        RestTemplateBuilder restTemplateBuilder) {

    return restTemplateBuilder

Manual creation of RestTemplate instances is a potentially troublesome approach because other auto-configured beans are not being injected in manually created instances.

Populating a ComboBox using C#

Simple way is:

Dictionary<string, string> dict = new Dictionary<string, string>()
    {"English ","En" },
    {"Italian  ","It" },
    {"Spainish  ","Sp " }

combo.DataSource = new BindingSource(dict, null);
combo.DisplayMember = "Key";
combo.ValueMember = "Value";

RegEx for valid international mobile phone number

Even if you write a regular expression that matches exactly the subset "valid phone numbers" out of strings, there is no way to guarantee (by way of a regular expression) that they are valid mobile phone numbers. In several countries, mobile phone numbers are indistinguishable from landline phone numbers without at least a number plan lookup, and in some cases, even that won't help. For example, in Sweden, lots of people have "ported" their regular, landline-like phone number to their mobile phone. It's still the same number as they had before, but now it goes to a mobile phone instead of a landline.

Since valid phone numbers consist only of digits, I doubt that rolling your own would risk missing some obscure case of phone number at least. If you want to have better certainty, write a generator that takes a list of all valid country codes, and requires one of them at the beginning of the phone number to be matched by the generated regular expression.

Unique random string generation

This works perfect for me

    private string GeneratePasswordResetToken()
        string token = Guid.NewGuid().ToString();
        var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(token);
        return Convert.ToBase64String(plainTextBytes);

How to manage a redirect request after a jQuery Ajax call

I solved this issue by:

  1. Adding a custom header to the response:

    public ActionResult Index(){
        if (!HttpContext.User.Identity.IsAuthenticated)
        return View();
  2. Binding a JavaScript function to the ajaxSuccess event and checking to see if the header exists:

    $(document).ajaxSuccess(function(event, request, settings) {
        if (request.getResponseHeader('REQUIRES_AUTH') === '1') {
           window.location = '/';

Javascript seconds to minutes and seconds

2019 best variant

Format hh:mm:ss

console.log(display(60 * 60 * 2.5 + 25)) // 2.5 hours + 25 seconds_x000D_
function display (seconds) {_x000D_
  const format = val => `0${Math.floor(val)}`.slice(-2)_x000D_
  const hours = seconds / 3600_x000D_
  const minutes = (seconds % 3600) / 60_x000D_
  return [hours, minutes, seconds % 60].map(format).join(':')_x000D_

byte[] to hex string

There is a built in method for this:

byte[] data = { 1, 2, 4, 8, 16, 32 };

string hex = BitConverter.ToString(data);

Result: 01-02-04-08-10-20

If you want it without the dashes, just remove them:

string hex = BitConverter.ToString(data).Replace("-", string.Empty);

Result: 010204081020

If you want a more compact representation, you can use Base64:

string base64 = Convert.ToBase64String(data);

Result: AQIECBAg

Temporarily disable all foreign key constraints

not need to run queries to sidable FKs on sql. If you have a FK from table A to B, you should:

  • delete data from table A
  • delete data from table B
  • insert data on B
  • insert data on A

You can also tell the destination not to check constraints

enter image description here

Converting BitmapImage to Bitmap and vice versa

There is no need to use foreign libraries.

Convert a BitmapImage to Bitmap:

private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
    // BitmapImage bitmapImage = new BitmapImage(new Uri("../Images/test.png", UriKind.Relative));

    using(MemoryStream outStream = new MemoryStream())
        BitmapEncoder enc = new BmpBitmapEncoder();
        System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(outStream);

        return new Bitmap(bitmap);

To convert the Bitmap back to a BitmapImage:

public static extern bool DeleteObject(IntPtr hObject);

private BitmapImage Bitmap2BitmapImage(Bitmap bitmap)
    IntPtr hBitmap = bitmap.GetHbitmap();
    BitmapImage retval;

        retval = (BitmapImage)Imaging.CreateBitmapSourceFromHBitmap(

    return retval;

Create a user with all privileges in Oracle

My issue was, i am unable to create a view with my "scott" user in oracle 11g edition. So here is my solution for this

Error in my case

SQL>create view v1 as select * from books where id=10;

insufficient privileges.


1)open your cmd and change your directory to where you install your oracle database. in my case i was downloaded in E drive so my location is E:\app\B_Amar\product\11.2.0\dbhome_1\BIN> after reaching in the position you have to type sqlplus sys as sysdba

E:\app\B_Amar\product\11.2.0\dbhome_1\BIN>sqlplus sys as sysdba

2) Enter password: here you have to type that password that you give at the time of installation of oracle software.

3) Here in this step if you want create a new user then you can create otherwise give all the privileges to existing user.

for creating new user

SQL> create user abc identified by xyz;

here abc is user and xyz is password.

giving all the privileges to abc user

SQL> grant all privileges to abc;

 grant succeeded. 

if you are seen this message then all the privileges are giving to the abc user.

4) Now exit from cmd, go to your SQL PLUS and connect to the user i.e enter your username & password.Now you can happily create view.

In My case

in cmd E:\app\B_Amar\product\11.2.0\dbhome_1\BIN>sqlplus sys as sysdba

SQL> grant all privileges to SCOTT;

grant succeeded.

Now I can create views.

How to disable JavaScript in Chrome Developer Tools?

On Mac OS X:

  • Preferences
  • Show advanced settings
  • Press the "content settings" button
  • Scroll to the "JavaScript" section
  • Check the checkbox in front of "Do not allow any site to run JavaScript"

The Chrome Quick JavaScript Switcher extension is a lot easier though :-)

How can you search Google Programmatically Java API

As an alternative to BalusC answer as it has been deprecated and you have to use proxies, you can use this package. Code sample:

Map<String, String> parameter = new HashMap<>();
parameter.put("q", "Coffee");
parameter.put("location", "Portland");
GoogleSearchResults serp = new GoogleSearchResults(parameter);

JsonObject data = serp.getJson();
JsonArray results = (JsonArray) data.get("organic_results");
JsonObject first_result = results.get(0).getAsJsonObject();
System.out.println("first coffee: " + first_result.get("title").getAsString());

Library on GitHub

Subtract two variables in Bash

Try this Bash syntax instead of trying to use an external program expr:


BTW, the correct syntax of using expr is:

count=$(expr $FIRSTV - $SECONDV)

But keep in mind using expr is going to be slower than the internal Bash syntax I provided above.

I/O error(socket error): [Errno 111] Connection refused

Its seems that server is not running properly so ensure that with terminal by

telnet ip port


telnet localhost 8069

It will return connected to localhost so it indicates that there is no problem with the connection Else it will return Connection refused it indicates that there is problem with the connection

How to replace multiple substrings of a string?

Another example : Input list

error_list = ['[br]', '[ex]', 'Something']
words = ['how', 'much[ex]', 'is[br]', 'the', 'fish[br]', 'noSomething', 'really']

The desired output would be

words = ['how', 'much', 'is', 'the', 'fish', 'no', 'really']

Code :

[n[0][0] if len(n[0]) else n[1] for n in [[[w.replace(e,"") for e in error_list if e in w],w] for w in words]] 

How to read a .xlsx file using the pandas Library in iPython?

The following worked for me:

from pandas import read_excel
my_sheet = 'Sheet1' # change it to your sheet name, you can find your sheet name at the bottom left of your excel file
file_name = 'products_and_categories.xlsx' # change it to the name of your excel file
df = read_excel(file_name, sheet_name = my_sheet)
print(df.head()) # shows headers with top 5 rows

AppFabric installation failed because installer MSI returned with error code : 1603

I had this same error. Just had to install IIS and everything worked.

How to duplicate a whole line in Vim?


will yank the current line without deleting it


will delete the current line


will put a line grabbed by either of the previous methods

How do I run a Python script from C#?

Execute Python script from C

Create a C# project and write the following code.

using System;
using System.Diagnostics;
using System.IO;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApplication1
    public partial class Form1 : Form
        public Form1()

        private void button1_Click(object sender, EventArgs e)

        private void run_cmd()

            string fileName = @"C:\";

            Process p = new Process();
            p.StartInfo = new ProcessStartInfo(@"C:\Python27\python.exe", fileName)
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true

            string output = p.StandardOutput.ReadToEnd();




Python sample_script

print "Python C# Test"

You will see the 'Python C# Test' in the console of C#.

Bootstrap 3 offset on right not left

I modified Bootstrap SASS (v3.3.5) based on Rukshan's answer

Add this in the end of the calc-grid-column mixin in mixins/_grid-framework.scss, right below the $type == offset if condition.

@if ($type == offset-right) {
      .col-#{$class}-offset-right-#{$index} {
          margin-right: percentage(($index / $grid-columns));

Modify the make-grid mixin in mixins/_grid-framework.scss to generate the offset-right classes.

// Create grid for specific class
@mixin make-grid($class) {
  @include float-grid-columns($class);
  @include loop-grid-columns($grid-columns, $class, width);
  @include loop-grid-columns($grid-columns, $class, pull);
  @include loop-grid-columns($grid-columns, $class, push);
  @include loop-grid-columns($grid-columns, $class, offset);
  @include loop-grid-columns($grid-columns, $class, offset-right);

You can then use the classes like col-sm-offset-right-2 and col-md-offset-right-1

Change package name for Android in React Native

To change package I have searched and tried many methods but some are very hard and some are outdated. While searching I found a website that discuss a very simple method that are tested and personally i have also used this. Link :

Using PowerShell to remove lines from a text file if it contains a string

The pipe character | has a special meaning in regular expressions. a|b means "match either a or b". If you want to match a literal | character, you need to escape it:

... | Select-String -Pattern 'H\|159' -NotMatch | ...

exception.getMessage() output with class name

My guess is that you've got something in method1 which wraps one exception in another, and uses the toString() of the nested exception as the message of the wrapper. I suggest you take a copy of your project, and remove as much as you can while keeping the problem, until you've got a short but complete program which demonstrates it - at which point either it'll be clear what's going on, or we'll be in a better position to help fix it.

Here's a short but complete program which demonstrates RuntimeException.getMessage() behaving correctly:

public class Test {
    public static void main(String[] args) {
        try {
        } catch (Exception e) {
            System.out.println("Error: " + e.getMessage());

    private static void failingMethod() {
        throw new RuntimeException("Just the message");


Error: Just the message

Private class declaration

You can.

package test;

public class Test {
    public static void main(String[] args) {
        B b = new B();

class B {
  // Essentially package-private - cannot be accessed anywhere else but inside the `test` package

Split a python list into other "sublists" i.e smaller lists

I'd say

chunks = [data[x:x+100] for x in range(0, len(data), 100)]

If you are using python 2.x instead of 3.x, you can be more memory-efficient by using xrange(), changing the above code to:

chunks = [data[x:x+100] for x in xrange(0, len(data), 100)]

Making an API call in Python with an API that requires a bearer token

It just means it expects that as a key in your header data

import requests
endpoint = ".../api/ip"
data = {"ip": ""}
headers = {"Authorization": "Bearer MYREALLYLONGTOKENIGOT"}

print(, data=data, headers=headers).json())

Does C# have an equivalent to JavaScript's encodeURIComponent()?

I tried to do full compatible analog of javascript's encodeURIComponent for c# and after my 4 hour experiments I found this

c# CODE:

string a = "!@#$%^&*()_+ some text here ??? ??????? ????";
a = System.Web.HttpUtility.UrlEncode(a);
a = a.Replace("+", "%20");

the result is: !%40%23%24%25%5e%26*()_%2b%20some%20text%20here%20%d0%b0%d0%bb%d0%b8%20%d0%bc%d0%b0%d0%bc%d0%b5%d0%b4%d0%be%d0%b2%20%d0%b1%d0%b0%d0%ba%d1%83

After you decode It with Javascript's decodeURLComponent();

you will get this: !@#$%^&*()_+ some text here ??? ??????? ????

Thank You for attention

Failed to decode downloaded font, OTS parsing error: invalid version tag + rails 4

I've had the same issue.

Adding the font version (e.g. ?v=1.101) to the font URLS should do the trick ;)

@font-face {
    font-family: 'Open Sans';
    font-style: normal;
    font-weight: 600;
    src: url('../fonts/open-sans-v15-latin-600.eot?v=1.101'); /* IE9 Compat Modes */
    src: local('Open Sans SemiBold'), local('OpenSans-SemiBold'),
    url('../fonts/open-sans-v15-latin-600.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
    url('../fonts/open-sans-v15-latin-600.woff2?v=1.101') format('woff2'), /* Super Modern Browsers */
    url('../fonts/open-sans-v15-latin-600.woff?v=1.101') format('woff'), /* Modern Browsers */
    url('../fonts/open-sans-v15-latin-600.ttf') format('truetype'), /* Safari, Android, iOS */
    url('../fonts/open-sans-v15-latin-600.svg#OpenSans') format('svg'); /* Legacy iOS */

Clicking (right mouse click) on font's TTF version and selecting "Get Info" (Mac OSX) "Properties" (Windows) in context menu should be enough to access the font version.

jQuery position DIV fixed at top on scroll

instead of doing it like that, why not just make the flyout position:fixed, top:0; left:0; once your window has scrolled pass a certain height:


      if ($(this).scrollTop() > 135) {
      } else {


.fixed {position:fixed; top:0; left:0;}


Get ID from URL with jQuery

My url is like this . I want to get 503 . I wrote the following code .

var baseUrl = (window.location).href; // You can also use document.URL
var koopId = baseUrl.substring(baseUrl.lastIndexOf('=') + 1);

If you use

var v = window.location.pathname;

You will get only "/";

How to create a generic array in Java?

You do not need to pass the Class argument to the constructor. Try this.

public class GenSet<T> {
    private final T[] array;
    public GenSet(int capacity, T... dummy) {
        if (dummy.length > 0)
            throw new IllegalArgumentException(
              "Do not provide values for dummy argument.");
        Class<?> c = dummy.getClass().getComponentType();
        array = (T[])Array.newInstance(c, capacity);
    public String toString() {
        return "GenSet of " + array.getClass().getComponentType().getName()
            + "[" + array.length + "]";


GenSet<Integer> intSet = new GenSet<>(3);
System.out.println(new GenSet<String>(2));


GenSet of java.lang.Integer[3]
GenSet of java.lang.String[2]

Model backing a DB Context has changed; Consider Code First Migrations

In my case this error was caused by the existence of the _MigrationsHistory table in the database. Deleting that table fixed the problem. Not sure how that table got into our test environment database.

SSH library for Java

Update: The GSOC project and the code there isn't active, but this is:

hierynomus took over as maintainer since early 2015. Here is the older, no longer maintained, Github link:

There was a GSOC project:

Code quality seem to be better than JSch, which, while a complete and working implementation, lacks documentation. Project page spots an upcoming beta release, last commit to the repository was mid-august.

Compare the APIs:

    SSHClient ssh = new SSHClient();
    try {
        new SCPDownloadClient(ssh).copy("ten", "/tmp");
    } finally {

Session session = null;
Channel channel = null;

try {

JSch jsch = new JSch();
session = jsch.getSession(username, host, 22);
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");

// exec 'scp -f rfile' remotely
String command = "scp -f " + remoteFilename;
channel = session.openChannel("exec");
((ChannelExec) channel).setCommand(command);

// get I/O streams for remote scp
OutputStream out = channel.getOutputStream();
InputStream in = channel.getInputStream();


byte[] buf = new byte[1024];

// send '\0'
buf[0] = 0;
out.write(buf, 0, 1);

while (true) {
    int c = checkAck(in);
    if (c != 'C') {

    // read '0644 ', 0, 5);

    long filesize = 0L;
    while (true) {
        if (, 0, 1) < 0) {
            // error
        if (buf[0] == ' ') {
        filesize = filesize * 10L + (long) (buf[0] - '0');

    String file = null;
    for (int i = 0;; i++) {, i, 1);
        if (buf[i] == (byte) 0x0a) {
            file = new String(buf, 0, i);

    // send '\0'
    buf[0] = 0;
    out.write(buf, 0, 1);

    // read a content of lfile
    FileOutputStream fos = null;

    fos = new FileOutputStream(localFilename);
    int foo;
    while (true) {
        if (buf.length < filesize) {
            foo = buf.length;
        } else {
            foo = (int) filesize;
        foo =, 0, foo);
        if (foo < 0) {
            // error
        fos.write(buf, 0, foo);
        filesize -= foo;
        if (filesize == 0L) {
    fos = null;

    if (checkAck(in) != 0) {

    // send '\0'
    buf[0] = 0;
    out.write(buf, 0, 1);


} catch (JSchException jsche) {
} catch (IOException ioe) {
} finally {


How to convert a factor to integer\numeric without loss of information?

It is possible only in the case when the factor labels match the original values. I will explain it with an example.

Assume the data is vector x:

x <- c(20, 10, 30, 20, 10, 40, 10, 40)

Now I will create a factor with four labels:

f <- factor(x, levels = c(10, 20, 30, 40), labels = c("A", "B", "C", "D"))

1) x is with type double, f is with type integer. This is the first unavoidable loss of information. Factors are always stored as integers.

> typeof(x)
[1] "double"
> typeof(f)
[1] "integer"

2) It is not possible to revert back to the original values (10, 20, 30, 40) having only f available. We can see that f holds only integer values 1, 2, 3, 4 and two attributes - the list of labels ("A", "B", "C", "D") and the class attribute "factor". Nothing more.

> str(f)
 Factor w/ 4 levels "A","B","C","D": 2 1 3 2 1 4 1 4
> attributes(f)
[1] "A" "B" "C" "D"

[1] "factor"

To revert back to the original values we have to know the values of levels used in creating the factor. In this case c(10, 20, 30, 40). If we know the original levels (in correct order), we can revert back to the original values.

> orig_levels <- c(10, 20, 30, 40)
> x1 <- orig_levels[f]
> all.equal(x, x1)
[1] TRUE

And this will work only in case when labels have been defined for all possible values in the original data.

So if you will need the original values, you have to keep them. Otherwise there is a high chance it will not be possible to get back to them only from a factor.

C - determine if a number is prime

I'm suprised that no one mentioned this.

Use the Sieve Of Eratosthenes


  1. Basically nonprime numbers are divisible by another number besides 1 and themselves
  2. Therefore: a nonprime number will be a product of prime numbers.

The sieve of Eratosthenes finds a prime number and stores it. When a new number is checked for primeness all of the previous primes are checked against the know prime list.


  1. This algorithm/problem is known as "Embarrassingly Parallel"
  2. It creates a collection of prime numbers
  3. Its an example of a dynamic programming problem
  4. Its quick!

How to send a compressed archive that contains executables so that Google's attachment filter won't reject it

To bypass google's check, which is what you really want, simply remove the extensions from the file when you send it, and add them back after you download it. For example:

  • tar czvf file.tar.gz directory
  • mv file.tar.gz filetargz
  • [send filetargz via gmail]
  • [download filetargz]
  • [rename filetargz to file.tar.gz and open]

How to pass objects to functions in C++?

Since no one mentioned I am adding on it, When you pass a object to a function in c++ the default copy constructor of the object is called if you dont have one which creates a clone of the object and then pass it to the method, so when you change the object values that will reflect on the copy of the object instead of the original object, that is the problem in c++, So if you make all the class attributes to be pointers, then the copy constructors will copy the addresses of the pointer attributes , so when the method invocations on the object which manipulates the values stored in pointer attributes addresses, the changes also reflect in the original object which is passed as a parameter, so this can behave same a Java but dont forget that all your class attributes must be pointers, also you should change the values of pointers, will be much clear with code explanation.

Class CPlusPlusJavaFunctionality {
         attribute = new int;
         *attribute = value;

       void setValue(int value){
           *attribute = value;

       void getValue(){
          return *attribute;

       ~ CPlusPlusJavaFuncitonality(){

       int *attribute;

void changeObjectAttribute(CPlusPlusJavaFunctionality obj, int value){
   int* prt = obj.attribute;
   *ptr = value;

int main(){

   CPlusPlusJavaFunctionality obj;


   cout<< obj.getValue();  //output: 10

   changeObjectAttribute(obj, 15);

   cout<< obj.getValue();  //output: 15

But this is not good idea as you will be ending up writing lot of code involving with pointers, which are prone for memory leaks and do not forget to call destructors. And to avoid this c++ have copy constructors where you will create new memory when the objects containing pointers are passed to function arguments which will stop manipulating other objects data, Java does pass by value and value is reference, so it do not require copy constructors.

How do I force a vertical scrollbar to appear?

html { overflow-y: scroll; }

This css rule causes a vertical scrollbar to always appear.


Python concatenate text files

What's wrong with UNIX commands ? (given you're not working on Windows) :

ls | xargs cat | tee output.txt does the job ( you can call it from python with subprocess if you want)

What is *.o file?

A file ending in .o is an object file. The compiler creates an object file for each source file, before linking them together, into the final executable.

How to convert std::string to LPCWSTR in C++ (Unicode)

The solution is actually a lot easier than any of the other suggestions:

std::wstring stemp = std::wstring(s.begin(), s.end());
LPCWSTR sw = stemp.c_str();

Best of all, it's platform independent.

phpMyAdmin access denied for user 'root'@'localhost' (using password: NO)

found a solution, in my config file I just changed

$cfg['Servers'][$i]['auth_type'] = 'config';


$cfg['Servers'][$i]['auth_type'] = 'HTTP';

Using JavaMail with TLS

Just use the following code. It is really useful to send email via Java, and it works:

import java.util.*;
import javax.activation.CommandMap;
import javax.activation.MailcapCommandMap;
import javax.mail.*;
import javax.mail.Provider;
import javax.mail.internet.*;

public class Main {

    public static void main(String[] args) {
            final String username="[email protected]";
            final String password="password";
            Properties prop=new Properties();
            prop.put("mail.smtp.auth", "true");
            prop.put("", "");
            prop.put("mail.smtp.port", "587");
            prop.put("mail.smtp.starttls.enable", "true");

            Session session = Session.getDefaultInstance(prop,
          new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
          try {
                 String body="Dear Renish Khunt Welcome";
                 String htmlBody = "<strong>This is an HTML Message</strong>";
                 String textBody = "This is a Text Message.";
         Message message = new MimeMessage(session);
         message.setFrom(new InternetAddress("[email protected]"));
                 message.setRecipients(Message.RecipientType.TO,InternetAddress.parse("[email protected]"));
        message.setSubject("Testing Subject");
        MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
        mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");
        mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
        mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
        mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
        mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
                        message.setContent(textBody, "text/html");


        } catch (MessagingException e) {



Stopping a JavaScript function when a certain condition is met

Use a try...catch statement in your main function and whenever you want to stop the function just use:

throw new Error("Stopping the function!");

Edit and Continue: "Changes are not allowed when..."

If you're debugging an ASP.NET application, go to properties > web > Servers, and make sure that "enable and continue" is checked under Use Visual Studio Development Server.

Get top most UIViewController

have this extension

Swift 2.*

extension UIApplication {
    class func topViewController(controller: UIViewController? = UIApplication.sharedApplication().keyWindow?.rootViewController) -> UIViewController? {
        if let navigationController = controller as? UINavigationController {
            return topViewController(navigationController.visibleViewController)
        if let tabController = controller as? UITabBarController {
            if let selected = tabController.selectedViewController {
                return topViewController(selected)
        if let presented = controller?.presentedViewController {
            return topViewController(presented)
        return controller

Swift 3

extension UIApplication {
    class func topViewController(controller: UIViewController? = UIApplication.shared.keyWindow?.rootViewController) -> UIViewController? {
        if let navigationController = controller as? UINavigationController {
            return topViewController(controller: navigationController.visibleViewController)
        if let tabController = controller as? UITabBarController {
            if let selected = tabController.selectedViewController {
                return topViewController(controller: selected)
        if let presented = controller?.presentedViewController {
            return topViewController(controller: presented)
        return controller

You can you use this anywhere on your controller

if let topController = UIApplication.topViewController() {


Oracle Date TO_CHAR('Month DD, YYYY') has extra spaces in it

Why are there extra spaces between my month and day? Why does't it just put them next to each other?

So your output will be aligned.

If you don't want padding use the format modifier FM:

SELECT TO_CHAR (date_field, 'fmMonth DD, YYYY') 
  FROM ...;

Reference: Format Model Modifiers

Convert NSArray to NSString in Objective-C

NSString * result = [[array valueForKey:@"description"] componentsJoinedByString:@""];

How to get the integer value of day of week

Try this. It will work just fine:

int week = Convert.ToInt32(currentDateTime.DayOfWeek);

When to use margin vs padding in CSS

The best I've seen explaining this with examples, diagrams, and even a 'try it yourself' view is here.

The diagram below I think gives an instant visual understanding of the difference.

enter image description here

One thing to keep in mind is standards compliant browsers (IE quirks is an exception) render only the content portion to the given width, so keep track of this in layout calculations. Also note that border box is seeing somewhat of a comeback with Bootstrap 3 supporting it.

Code snippet or shortcut to create a constructor in Visual Studio

Type "ctor" + TAB + TAB (hit the Tab key twice). This will create the default constructor for the class you are in:

public MyClass()


It seems that in some cases you will have to press TAB twice.

How to record phone calls in android?

There is a simple solution to this problem using this library. I store an instance of the CallRecord class in MyService.class. When the service is first initialized, the following code is executed:

public class MyService extends Service {

    public static CallRecord callRecord;

    public void onCreate() {

        callRecord = new CallRecord.Builder(this)
                .setRecordDirPath(Environment.getExternalStorageDirectory().getPath()) // optional & default value
                .setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB) // optional & default value
                .setOutputFormat(MediaRecorder.OutputFormat.AMR_NB) // optional & default value
                .setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION) // optional & default value
                .setShowSeed(false) // optional, default=true ->Ex: RecordFileName_incoming.amr || RecordFileName_outgoing.amr

    public void onDestroy() {

Next, do not forget to specify permissions in the manifest. (I may have some extras here, but keep in mind that some of them are necessary only for newer versions of Android)

<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.READ_CALL_LOG" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.PROCESS_INCOMING_CALLS" />
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Also it is crucial to request some permissions at the first start of the application. A guide is provided here.

If my code doesn't work, alternative code can be found here. I hope I helped you.

Sort array of objects by string property value

One more option:

var someArray = [...];

function generateSortFn(prop, reverse) {
    return function (a, b) {
        if (a[prop] < b[prop]) return reverse ? 1 : -1;
        if (a[prop] > b[prop]) return reverse ? -1 : 1;
        return 0;

someArray.sort(generateSortFn('name', true));

sorts ascending by default.

How to check iOS version?

The quick answer …

As of Swift 2.0, you can use #available in an if or guard to protect code that should only be run on certain systems.

if #available(iOS 9, *) {}

In Objective-C, you need to check the system version and perform a comparison.

[[NSProcessInfo processInfo] operatingSystemVersion] in iOS 8 and above.

As of Xcode 9:

if (@available(iOS 9, *)) {}

The full answer …

In Objective-C, and Swift in rare cases, it's better to avoid relying on the operating system version as an indication of device or OS capabilities. There is usually a more reliable method of checking whether a particular feature or class is available.

Checking for the presence of APIs:

For example, you can check if UIPopoverController is available on the current device using NSClassFromString:

if (NSClassFromString(@"UIPopoverController")) {
    // Do something

For weakly linked classes, it is safe to message the class, directly. Notably, this works for frameworks that aren't explicitly linked as "Required". For missing classes, the expression evaluates to nil, failing the condition:

if ([LAContext class]) {
    // Do something

Some classes, like CLLocationManager and UIDevice, provide methods to check device capabilities:

if ([CLLocationManager headingAvailable]) {
    // Do something

Checking for the presence of symbols:

Very occasionally, you must check for the presence of a constant. This came up in iOS 8 with the introduction of UIApplicationOpenSettingsURLString, used to load Settings app via -openURL:. The value didn't exist prior to iOS 8. Passing nil to this API will crash, so you must take care to verify the existence of the constant first:

if (&UIApplicationOpenSettingsURLString != NULL) {
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];

Comparing against the operating system version:

Let's assume you're faced with the relatively rare need to check the operating system version. For projects targeting iOS 8 and above, NSProcessInfo includes a method for performing version comparisons with less chance of error:

- (BOOL)isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion)version

Projects targeting older systems can use systemVersion on UIDevice. Apple uses it in their GLSprite sample code.

// A system version of 3.1 or greater is required to use CADisplayLink. The NSTimer
// class is used as fallback when it isn't available.
NSString *reqSysVer = @"3.1";
NSString *currSysVer = [[UIDevice currentDevice] systemVersion];
if ([currSysVer compare:reqSysVer options:NSNumericSearch] != NSOrderedAscending) {
    displayLinkSupported = TRUE;

If for whatever reason you decide that systemVersion is what you want, make sure to treat it as an string or you risk truncating the patch revision number (eg. 3.1.2 -> 3.1).

PHP-FPM doesn't write to error log

There are multiple php config files, but THIS is the one you need to edit:


uncomment the line that says:


That will allow PHPs stderr to go to php-fpm's error log instead of /dev/null.

Can Mockito stub a method without regard to the argument?

anyObject() should fit your needs.

Also, you can always consider implementing hashCode() and equals() for the Bazoo class. This would make your code example work the way you want.

SQL Combine Two Columns in Select Statement

SELECT StaffId,(Title+''+FirstName+''+LastName) AS FullName 
FROM StaffInformation

Where do you write with in the brackets this will be appear in the one single column. Where do you want a dot into the middle of the Title and First Name write syntax below,

SELECT StaffId,(Title+'.'+FirstName+''+LastName) AS FullName 
FROM StaffInformation

These syntax works with MS SQL Server 2008 R2 Express Edition.

Get filename in batch for loop

When Command Extensions are enabled (Windows XP and newer, roughly), you can use the syntax %~nF (where F is the variable and ~n is the request for its name) to only get the filename.

FOR /R C:\Directory %F in (*.*) do echo %~nF

should echo only the filenames.