Programs & Examples On #Datetime generation

Converting HTML files to PDF

Is there maybe a way to grab the rendered page from the internet explorer rendering engine and send it to a PDF-Printer tool automatically?

This is how ActivePDF works, which is good means that you know what you'll get, and it actually has reasonable styling support.

It is also one of the few packages I found (when looking a few years back) that actually supports the various page-break CSS commands.

Unfortunately, the ActivePDF software is very frustrating - since it has to launch the IE browser in the background for conversions it can be quite slow, and it is not particularly stable either.

There is a new version currently in Beta which is supposed to be much better, but I've not actually had a chance to try it out, so don't know how much of an improvement it is.

How do I sort an NSMutableArray with custom objects in it?

I tried all, but this worked for me. In a class I have another class named "crimeScene", and want to sort by a property of "crimeScene".

This works like a charm:

NSSortDescriptor *sorter = [[NSSortDescriptor alloc] initWithKey:@"crimeScene.distance" ascending:YES];
[self.arrAnnotations sortUsingDescriptors:[NSArray arrayWithObject:sorter]];

How to enable mod_rewrite for Apache 2.2

Open terminal and typin a2enmod rewrite, It will enable your mod_rewrite module for Apache.

Then go to /etc/apache2/sites-available and edit default file. (For this you must have writable permissions to this file and sites-available folder.)

Replace below with existing lines 4 to 14

DocumentRoot /var/www
<Directory />
Options FollowSymLinks
AllowOverride All
<Directory /var/www/>
Options Indexes FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all

Now restart your apache by /etc/init.d/apache2 restart or service apache2 restart

Take clean URL test again and this time it will be passed.

Where is my .vimrc file?

on unix vim --version tells you the various locations of the vim config files :

   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/share/vim"

How to convert a DataTable to a string in C#?

I created my variant of class for your needs. I believe it is a bit more configurable than already provided variants. You can use it with all default settings just create an instance of a class and call StringifyDataTable method, or you can set additional options if needed.

public class DataTableStringifier
    public bool IsOuterBordersPresent { get; set; } //Whether outer borders of table needed
    public bool IsHeaderHorizontalSeparatorPresent { get; set; } // Whether horizontal line separator between table title and data is needed. Useful to set 'false' if you expect only 1 or 2 rows of data - no need for additional lines then
    public char ValueSeparator { get; set; } //Vertical line character
    public char HorizontalLinePadChar { get; set; } // Horizontal line character
    public char HorizontalLineSeparator { get; set; } // Horizontal border (between header and data) column separator (crossing of horizontal and vertical borders)
    public int ValueMargin { get; set; } // Horizontal margin from table borders (inner and outer) to cell values
    public int MaxColumnWidth { get; set; } // To avoid too wide columns with thousands of characters. Longer values will be cropped in the center
    public string LongValuesEllipses { get; set; } // Cropped values wil be inserted this string in the middle to mark the point of cropping

    public DataTableStringifier()
        MaxColumnWidth = int.MaxValue;
        IsHeaderHorizontalSeparatorPresent = true;
        ValueSeparator = '|';
        ValueMargin = 1;
        HorizontalLinePadChar = '-';
        HorizontalLineSeparator = '+';
        LongValuesEllipses = "...";
        IsOuterBordersPresent = false;

    public string StringifyDataTable(DataTable table)
        int colCount = table.Columns.Count;
        int rowCount = table.Rows.Count;
        string[] colHeaders = new string[colCount];
        string[,] cells = new string[rowCount, colCount];
        int[] colWidth = new int[colCount];

        for (int i = 0; i < colCount; i++)
            var column = table.Columns[i];
            var colName = ValueToLimitedLengthString(column.ColumnName);
            colHeaders[i] = colName;
            if (colWidth[i] < colName.Length)
                colWidth[i] = colName.Length;

        for (int i = 0; i < rowCount; i++)
            DataRow row = table.Rows[i];
            for (int j = 0; j < colCount; j++)
                var valStr = ValueToLimitedLengthString(row[j]);
                cells[i, j] = valStr;
                if (colWidth[j] < valStr.Length)
                    colWidth[j] = valStr.Length;

        string valueSeparatorWithMargin = string.Concat(new string(' ', ValueMargin), ValueSeparator, new string(' ', ValueMargin));
        string leftBorder = IsOuterBordersPresent ? string.Concat(ValueSeparator, new string(' ', ValueMargin)) : "";
        string rightBorder = IsOuterBordersPresent ? string.Concat(new string(' ', ValueMargin), ValueSeparator) : "";
        string horizLine = new string(HorizontalLinePadChar, colWidth.Sum() + (colCount - 1)*(ValueMargin*2 + 1) + (IsOuterBordersPresent ? (ValueMargin + 1)*2 : 0));

        StringBuilder tableBuilder = new StringBuilder();

        if (IsOuterBordersPresent)

        for (int i = 0; i < colCount; i++)
            if (i < colCount - 1)

        if (IsHeaderHorizontalSeparatorPresent)
            if (IsOuterBordersPresent)
                tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
            for (int i = 0; i < colCount; i++)
                tableBuilder.Append(new string(HorizontalLinePadChar, colWidth[i]));
                if (i < colCount - 1)
                    tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
                    tableBuilder.Append(HorizontalLinePadChar, ValueMargin);
            if (IsOuterBordersPresent)
                tableBuilder.Append(HorizontalLinePadChar, ValueMargin);

        for (int i = 0; i < rowCount; i++)
            for(int j=0; j<colCount; j++)
                tableBuilder.Append(cells[i, j].PadRight(colWidth[j]));

        if (IsOuterBordersPresent)

        return tableBuilder.ToString(0, tableBuilder.Length - 1); //Trim last enter char

    private string ValueToLimitedLengthString(object value)
        string strValue = value.ToString();
        if (strValue.Length > MaxColumnWidth)
            int beginningLength = (MaxColumnWidth) / 2;
            int endingLength = (MaxColumnWidth + 1) / 2 - LongValuesEllipses.Length;
            return string.Concat(strValue.Substring(0, beginningLength), LongValuesEllipses, strValue.Substring(strValue.Length - endingLength, endingLength));
            return strValue;

Actual meaning of 'shell=True' in subprocess

>>> import subprocess
>>>'echo $HOME')
Traceback (most recent call last):
OSError: [Errno 2] No such file or directory
>>>'echo $HOME', shell=True)

Setting the shell argument to a true value causes subprocess to spawn an intermediate shell process, and tell it to run the command. In other words, using an intermediate shell means that variables, glob patterns, and other special shell features in the command string are processed before the command is run. Here, in the example, $HOME was processed before the echo command. Actually, this is the case of command with shell expansion while the command ls -l considered as a simple command.

source: Subprocess Module

how to use "AND", "OR" for RewriteCond on Apache?

Having trouble wrapping my head around this.

Have a rewrite rule with four conditions.
The first three conditions A, B, C are to be AND which is then OR with D

RewriteCond A       true
RewriteCond B       false
RewriteCond C [OR]  true
RewriteCond D       true
RewriteRule ...

But that seems to be an expression of A and B and (C or D) = false (don't rewrite)

How can I get to the desired expression? (A and B and C) or D = true (rewrite)

Preferably without using the additional steps of setting environment variables.


How do I plot list of tuples in Python?

If I get your question correctly, you could do something like this.

>>> import matplotlib.pyplot as plt
>>> testList =[(0, 6.0705199999997801e-08), (1, 2.1015700100300739e-08), 
 (2, 7.6280656623374823e-09), (3, 5.7348209304555086e-09), 
 (4, 3.6812203579604238e-09), (5, 4.1572516753310418e-09)]
>>> from math import log
>>> testList2 = [(elem1, log(elem2)) for elem1, elem2 in testList]
>>> testList2
[(0, -16.617236475334405), (1, -17.67799605473062), (2, -18.691431541177973), (3, -18.9767093108359), (4, -19.420021520728017), (5, -19.298411635970396)]
>>> zip(*testList2)
[(0, 1, 2, 3, 4, 5), (-16.617236475334405, -17.67799605473062, -18.691431541177973, -18.9767093108359, -19.420021520728017, -19.298411635970396)]
>>> plt.scatter(*zip(*testList2))

which would give you something like

enter image description here

Or as a line plot,

>>> plt.plot(*zip(*testList2))

enter image description here

EDIT - If you want to add a title and labels for the axis, you could do something like

>>> plt.scatter(*zip(*testList2))
>>> plt.title('Random Figure')
>>> plt.xlabel('X-Axis')
>>> plt.ylabel('Y-Axis')

which would give you

enter image description here

What's the longest possible worldwide phone number I should consider in SQL varchar(length) for phone

It's a bit worse, I use a calling card for international calls, so its local number in the US + account# (6 digits) + pin (4 digits) + "pause" + what you described above.

I suspect there might be other cases

convert 12-hour hh:mm AM/PM to 24-hour hh:mm

 var time = "9:09:59AM"
    var pmCheck =time.includes("PM");
    var hrs=parseInt(time.split(":")[0]);
    var newtime='';
    // this is for between  12 AM to 12:59:59AM  = 00:00:00
    if( hrs == 12  && pmCheck == false){
        newtime= "00" +':'+ time.split(":")[1] +':'+ time.split(":")[2].replace("AM",'');
    //this is for between  12 PM to 12:59:59 =12:00:00
    else if (hrs == 12  && pmCheck == true){
             newtime= "12" +':'+ time.split(":")[1] +':'+ time.split(":")[2].replace("PM",'');
    //this is for between 1 AM and 11:59:59 AM
    else if (!pmCheck){
        newtime= hrs +':'+ time.split(":")[1] +':'+ time.split(":")[2].replace("AM",'');
    //this is for between 1 PM and 11:59:59 PM
    else if(pmCheck){
        newtime= (hrs +12)+':'+ time.split(":")[1] +':'+ time.split(":")[2].replace("PM",'');

Create a file from a ByteArrayOutputStream

You can do it with using a FileOutputStream and the writeTo method.

ByteArrayOutputStream byteArrayOutputStream = getByteStreamMethod();
try(OutputStream outputStream = new FileOutputStream("thefilename")) {

Source: "Creating a file from ByteArrayOutputStream in Java." on Code Inventions

size of struct in C

Your default alignment is probably 4 bytes. Either the 30 byte element got 32, or the structure as a whole was rounded up to the next 4 byte interval.

How do I sort a VARCHAR column in SQL server that contains numbers?

This query is helpful for you. In this query, a column has data type varchar is arranged by good order.For example- In this column data are:- G1,G34,G10,G3. So, after running this query, you see the results: - G1,G10,G3,G34.

       (CASE WHEN ISNUMERIC(column_name) = 1 THEN 0 ELSE 1 END) IsNum
FROM table_name 
ORDER BY IsNum, LEN(column_name), column_name;

How to search in array of object in mongodb

Use $elemMatch to find the array of particular object

db.users.findOne({"_id": id},{awards: {$elemMatch: {award:'Turing Award', year:1977}}})

CSS Child vs Descendant selectors

CSS selection and applying style to a particular element can be done through traversing through the dom element [Example


.a .b .c .d{
    background: #bdbdbd;
    background: red;
<div class='a'>The first paragraph.
 <div class='b'>The second paragraph.
  <div class='c'>The third paragraph.
   <div class='d'>The fourth paragraph.</div>
   <div class='e'>The fourth paragraph.</div>

How to get current user, and how to use User class in MVC5?

If you want the ApplicationUser object in one line of code (if you have the latest ASP.NET Identity installed), try:

ApplicationUser user = System.Web.HttpContext.Current.GetOwinContext().GetUserManager<ApplicationUserManager>().FindById(System.Web.HttpContext.Current.User.Identity.GetUserId());

You'll need the following using statements:

using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;

How to launch another aspx web page upon button click?

Use an html button and javascript? in javascript, window.location is used to change the url location of the current window, while will open a new one

<input type="button" onclick="'newPage.aspx', 'newPage');" />

Edit: Ah, just found this: If the ID of your form tag is form1, set this attribute in your asp button

OnClientClick=" ='_blank';"

What are the lengths of Location Coordinates, latitude and longitude?

Please check the UTM coordinate system

These values must be in meters for a specific map projection. For example, the peak of Mount Assiniboine (at 50°52'10"N 115°39'03"W) in UTM Zone 11 is represented by 11U 594934.108296 5636174.091274 where (594934.108296, 5636174.091274) are in meters.

Why shouldn't `&apos;` be used to escape single quotes?

If you need to write semantically correct mark-up, even in HTML5, you must not use &apos; to escape single quotes. Although, I can imagine you actually meant apostrophe rather then single quote.

single quotes and apostrophes are not the same, semantically, although they might look the same.

Here's one apostrophe.

Use &#39; to insert it if you need HTML4 support. (edited)

In British English, single quotes are used like this:

"He told me to 'give it a try'", I said.

Quotes come in pairs. You can use:

<p><q>He told me to <q>give it a try</q></q>, I said.<p>

to have nested quotes in a semantically correct way, deferring the substitution of the actual characters to the rendering engine. This substitution can then be affected by CSS rules, like:

q {
  quotes: '"' '"' '<' '>';

An old but seemingly still relevant article about semantically correct mark-up: The Trouble With EM ’n EN (and Other Shady Characters).

(edited) This used to be:

Use ’ to insert it if you need HTML4 support.

But, as @James_pic pointed out, that is not the straight single quote, but the "Single curved quote, right".

Url to a google maps page to show a pin given a latitude / longitude?

From my notes:,-122.088715&spn=0.004250,0.011579&t=h&iwloc=A&hl=en

Which parses like this:

    q=latN+lonW+(label)     location of teardrop

    t=k             keyhole (satelite map)
    t=h             hybrid

    ll=lat,-lon     center of map
    spn=w.w,h.h     span of map, degrees

iwloc has something to do with the info window. hl is obviously language.

See also:

LaTeX Optional Arguments

I had a similar problem, when I wanted to create a command, \dx, to abbreviate \;\mathrm{d}x (i.e. put an extra space before the differential of the integral and have the "d" upright as well). But then I also wanted to make it flexible enough to include the variable of integration as an optional argument. I put the following code in the preamble.


   \ifthenelse{ \equal{#1}{} }


   $$\int x\dx$$
   $$\int t\dx[t]$$

gives \dx with optional argument

JavaScript override methods

Edit: It's now six years since the original answer was written and a lot has changed!

  • If you're using a newer version of JavaScript, possibly compiled with a tool like Babel, you can use real classes.
  • If you're using the class-like component constructors provided by Angular or React, you'll want to look in the docs for that framework.
  • If you're using ES5 and making "fake" classes by hand using prototypes, the answer below is still as right as it ever was.

Good luck!

JavaScript inheritance looks a bit different from Java. Here is how the native JavaScript object system looks:

// Create a class
function Vehicle(color){
  this.color = color;

// Add an instance method
Vehicle.prototype.go = function(){
  return "Underway in " + this.color;

// Add a second class
function Car(color){
  this.color = color;

// And declare it is a subclass of the first
Car.prototype = new Vehicle();

// Override the instance method
Car.prototype.go = function(){
  return + " car"

// Create some instances and see the overridden behavior.
var v = new Vehicle("blue");
v.go() // "Underway in blue"

var c = new Car("red");
c.go() // "Underway in red car"

Unfortunately this is a bit ugly and it does not include a very nice way to "super": you have to manually specify which parent classes' method you want to call. As a result, there are a variety of tools to make creating classes nicer. Try looking at Prototype.js, Backbone.js, or a similar library that includes a nicer syntax for doing OOP in js.

How to auto-scroll to end of div when data is added?

var objDiv = document.getElementById("divExample");
objDiv.scrollTop = objDiv.scrollHeight;

Android - How To Override the "Back" button so it doesn't Finish() my Activity?

Looks like im very late but for those of you who need to switch to new screen and clear back button stack here is a very simple solution.

startActivity(new Intent(this,your-new-screen.class));

The finishAffinity(); method clears back button stack.

How to retrieve checkboxes values in jQuery

If you want to insert the value of any checkbox immediately as it is being checked then this should work for you:


C++ floating point to integer type conversions

Normal way is to:

float f = 3.4;
int n = static_cast<int>(f);

jQuery UI Dialog window loaded within AJAX style jQuery UI Tabs

Just an addition to nicktea's answer. This code loads the content of a remote page (without redirecting there), and also cleans up when closing it.

<script type="text/javascript">
    function showDialog() {
            modal: true,
            open: function () {
            close: function(event, ui) {
            height: 400,
            width: 600,
            title: 'Ajax Page'

        return false;

Using "label for" on radio buttons

(Firstly read the other answers which has explained the for in the <label></label> tags. Well, both the tops answers are correct, but for my challenge, it was when you have several radio boxes, you should select for them a common name like name="r1" but with different ids id="r1_1" ... id="r1_2"

So this way the answer is more clear and removes the conflicts between name and ids as well.

You need different ids for different options of the radio box.

<input type="radio" name="r1" id="r1_1" />_x000D_
       <label for="r1_1">button text one</label>_x000D_
       <input type="radio" name="r1" id="r1_2" />_x000D_
       <label for="r1_2">button text two</label>_x000D_
       <input type="radio" name="r1" id="r1_3" />_x000D_
       <label for="r1_3">button text three</label>

JAXB Exception: Class not known to this context

This error message happens either because your ProfileDto class is not registered in the JAXB Content, or the class using it does not use @XmlSeeAlso(ProfileDto.class) to make processable by JAXB.

About your comment:

I was under the impression the annotations was only needed when the referenced class was a sub-class.

No, they are also needed when not declared in the JAXB context or, for example, when the only class having a static reference to it has this reference annotated with @XmlTransient. I maintain a tutorial here.

Is the MIME type 'image/jpg' the same as 'image/jpeg'?

No, image/jpg is not the same as image/jpeg.

You should use image/jpeg. Only image/jpeg is recognised as the actual mime type for JPEG files.

See, .

Serving the incorrect Content-Type of image/jpg to IE can cause issues, see

read input separated by whitespace(s) or newline...?

Use 'q' as the the optional argument to getline.

#include <iostream>
#include <sstream>

int main() {
    std::string numbers_str;
    getline( std::cin, numbers_str, 'q' );

    int number;
    for ( std::istringstream numbers_iss( numbers_str );
          numbers_iss >> number; ) {
        std::cout << number << ' ';

MySQL Trigger: Delete From Table AFTER DELETE

create trigger doct_trigger
after delete on doctor
for each row
delete from patient where patient.PrimaryDoctor_SSN=doctor.SSN ;

How do I check if a number is a palindrome?

In Python, there is a fast, iterative way.

def reverse(n):
    while n>0:
        newnum = newnum*10 + n % 10
    return newnum

def palindrome(n):
    return n == reverse(n)

This also prevents memory issues with recursion (like StackOverflow error in Java)

Shortcut to Apply a Formula to an Entire Column in Excel

Try double-clicking on the bottom right hand corner of the cell (ie on the box that you would otherwise drag).

Check if input is integer type in C

printf("type a number ");
int converted = scanf("%d", &a);

if( converted == 0) 
    printf("enter integer");
    system("PAUSE \n");
    return 0;

scanf() returns the number of format specifiers that match, so will return zero if the text entered cannot be interpreted as a decimal integer

Read only file system on Android

Try the following on the command prompt:

>adb remount
>adb push framework-res_old.apk /system/framework-res.apk

Printing list elements on separated lines in Python

A slightly more general solution based on join, that works even for pandas.Timestamp:

print("\n".join(map(str, my_list)))

Dart: mapping a list (

you can use => Tab(text: title)).toList()


    bottom: new TabBar(
      controller: _controller,
      isScrollable: true,
      tabs: => Tab(text: title)).toList()

Find if value in column A contains value from column B?

You can try this. :) simple solution!


Android open pdf file

The problem is that there is no app installed to handle opening the PDF. You should use the Intent Chooser, like so:

File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +"/"+ filename);
Intent target = new Intent(Intent.ACTION_VIEW);

Intent intent = Intent.createChooser(target, "Open File");
try {
} catch (ActivityNotFoundException e) {
    // Instruct the user to install a PDF reader here, or something

Fatal Error :1:1: Content is not allowed in prolog

The real solution that I found for this issue was by disabling any XML Format post processors. I have added a post processor called "jp@gc - XML Format Post Processor" and started noticing the error "Fatal Error :1:1: Content is not allowed in prolog"

By disabling the post processor had stopped throwing those errors.

How can I list all collections in the MongoDB shell?

show collections


show tables



Is there a way to only install the mysql client (Linux)?

Maybe try this:

yum -y groupinstall "MYSQL Database Client"

Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved

Some files where missing at your local repository. Usually under ${user.home}/.m2/repository/

Neets answer solves the problem. However if you dont want do download all the dependencies to your local repository again you could add the missing dependency to a project of yours and compile it.

Use the maven repository website to find the dependency. In your case was missing.

Copy the listed XML to the pom.xml file of your project. In this case


Run mvn compile in the root folder of the pom.xml. Maven will download all missing dependencies. After the download you can remove the added dependency.

Now you should be able to import the maven project or update the project without the error.

Tomcat is web server or application server?

Tomcat is an application container that is also a web server. An application container can run web-applications (have "application" scope). It is not considered Some people do not consider it a full application server as it is lacking in some aspects such as user management and the like, but getting better all the time..

Switch: Multiple values in one case?

you can try this.

switch (Valor)
                case (Valor1 & Valor2):


Base64 Java encode and decode a string

The following is a good solution -

import android.util.Base64;

String converted = Base64.encodeToString(toConvert.toString().getBytes(), Base64.DEFAULT);

String stringFromBase = new String(Base64.decode(converted, Base64.DEFAULT));

That's it. A single line encoding and decoding.

Actionbar notification count icon (badge) like Google has

Just to add. If someone wants to implement a filled circle bubble, heres the code (name it bage_circle.xml):

<shape xmlns:android=""

        android:color="#FFF" />



You may have to adjust the thickness according to your need.

enter image description here

EDIT: Here's the layout for button (name it badge_layout.xml):

<RelativeLayout xmlns:android=""



In Menu create item:


In onCreateOptionsMenu get reference to the Menu item:

    itemMessages = menu.findItem(;

    badgeLayout = (RelativeLayout) itemMessages.getActionView();
    itemMessagesBadgeTextView = (TextView) badgeLayout.findViewById(;
    itemMessagesBadgeTextView.setVisibility(View.GONE); // initially hidden

    iconButtonMessages = (IconButton) badgeLayout.findViewById(;

    iconButtonMessages.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            if (HJSession.getSession().getSessionId() != null) {

                Intent intent = new Intent(getThis(), HJActivityMessagesContexts.class);
                startActivityForResult(intent, HJRequestCodes.kHJRequestCodeActivityMessages.ordinal());
            } else {

After receiving notification for messages, set the count:

itemMessagesBadgeTextView.setText("" + count);

This code uses Iconify-fontawesome.

compile 'com.joanzapata.iconify:android-iconify-fontawesome:2.1.+'

javascript - replace dash (hyphen) with a space

replace() returns an new string, and the original string is not modified. You need to do

str = str.replace(/-/g, ' ');

Python loop that also accesses previous and next values

Two simple solutions:

  1. If variables for both previous and next values have to be defined:
alist = ['Zero', 'One', 'Two', 'Three', 'Four', 'Five']

prev = alist[0]
curr = alist[1]

for nxt in alist[2:]:
    print(f'prev: {prev}, curr: {curr}, next: {nxt}')
    prev = curr
    curr = nxt

prev: Zero, curr: One, next: Two
prev: One, curr: Two, next: Three
prev: Two, curr: Three, next: Four
prev: Three, curr: Four, next: Five
  1. If all values in the list have to be traversed by the current value variable:
alist = ['Zero', 'One', 'Two', 'Three', 'Four', 'Five']

prev = None
curr = alist[0]

for nxt in alist[1:] + [None]:
    print(f'prev: {prev}, curr: {curr}, next: {nxt}')
    prev = curr
    curr = nxt

prev: None, curr: Zero, next: One
prev: Zero, curr: One, next: Two
prev: One, curr: Two, next: Three
prev: Two, curr: Three, next: Four
prev: Three, curr: Four, next: Five
prev: Four, curr: Five, next: None

Java Command line arguments

Command line arguments are stored as strings in the String array String[] args that is passed tomain()`.

java [program name] [arg1,arg2 ,..]

Command line arguments are the inputs that accept from the command prompt while running the program. The arguments passed can be anything. Which is stored in the args[] array.

//Display all command line information
         class ArgDemo{
            public static void main(String args[]){
            System.out.println("there are "+args.length+"command-line arguments.");
            for(int i=0;i<args.length;i++)


java Argdemo one two

The output will be:

there are 2 command line arguments:
they are:

Why does this "Slow network detected..." log appear in Chrome?

Goto chrome://flags/#enable-webfonts-intervention-v2 and set it to disabled

It’s due to a bug in Chrome with their latest API for ‘network speed’. Hope it will be fixed in the next version

Archive the artifacts in Jenkins

An artifact can be any result of your build process. The important thing is that it doesn't matter on which client it was built it will be tranfered from the workspace back to the master (server) and stored there with a link to the build. The advantage is that it is versionized this way, you only have to setup backup on your master and that all artifacts are accesible via the web interface even if all build clients are offline.

It is possible to define a regular expression as the artifact name. In my case I zipped all the files I wanted to store in one file with a constant name during the build.

Saving timestamp in mysql table using php

Hey there, use the FROM_UNIXTIME() function for this.

Like this:

INSERT INTO table_name

Deleting rows from parent and child tables

If the children have FKs linking them to the parent, then you can use DELETE CASCADE on the parent.


CREATE TABLE supplier 
( supplier_id numeric(10) not null, 
 supplier_name varchar2(50) not null, 
 contact_name varchar2(50),  
 CONSTRAINT supplier_pk PRIMARY KEY (supplier_id) 

CREATE TABLE products 
( product_id numeric(10) not null, 
 supplier_id numeric(10) not null, 
 CONSTRAINT fk_supplier 
   FOREIGN KEY (supplier_id) 
  REFERENCES supplier(supplier_id) 

Delete the supplier, and it will delate all products for that supplier

What is the behavior difference between return-path, reply-to and from?

I had to add a Return-Path header in emails send by a Redmine instance. I agree with greatwolf only the sender can determine a correct (non default) Return-Path. The case is the following : E-mails are send with the default email address : [email protected] But we want that the real user initiating the action receives the bounce emails, because he will be the one knowing how to fix wrong recipients emails (and not the application adminstrators that have other cats to whip :-) ). We use this and it works perfectly well with exim on the application server and zimbra as the final company mail server.

Add items to comboBox in WPF

There are many ways to perform this task. Here is a simple one:

<Window x:Class="WPF_Demo1.MainWindow"
    Title="MainWindow" Height="500" Width="773">

<DockPanel LastChildFill="False">
    <StackPanel DockPanel.Dock="Top" Background="Red" Margin="2">
        <StackPanel Orientation="Horizontal" x:Name="spTopNav">
            <ComboBox x:Name="cboBox1" MinWidth="120"> <!-- Notice we have used x:Name to identify the object that we want to operate upon.-->
                <ComboBoxItem Content="X"/>
                <ComboBoxItem Content="Y"/>
                <ComboBoxItem Content="Z"/>
    <StackPanel DockPanel.Dock="Bottom" Background="Orange" Margin="2">
        <StackPanel Orientation="Horizontal" x:Name="spBottomNav">
        <TextBlock Height="30" Foreground="White">Left Docked StackPanel 2</TextBlock>
    <StackPanel MinWidth="200" DockPanel.Dock="Left" Background="Teal" Margin="2" x:Name="StackPanelLeft">
        <TextBlock  Foreground="White">Bottom Docked StackPanel Left</TextBlock>

    <StackPanel DockPanel.Dock="Right" Background="Yellow" MinWidth="150" Margin="2" x:Name="StackPanelRight"></StackPanel>
    <Button Content="Button" Height="410" VerticalAlignment="Top" Width="75" x:Name="myButton" Click="myButton_Click"/>



Next, we have the C# code:

    private void myButton_Click(object sender, RoutedEventArgs e)
        ComboBoxItem cboBoxItem = new ComboBoxItem(); // Create example instance of our desired type.
        Type type1 = cboBoxItem.GetType();
        object cboBoxItemInstance = Activator.CreateInstance(type1); // Construct an instance of that type.
        for (int i = 0; i < 12; i++)
            string newName = "stringExample" + i.ToString();
           // Generate the objects from our list of strings.
            ComboBoxItem item = this.CreateComboBoxItem((ComboBoxItem)cboBoxItemInstance, "nameExample_" + newName, newName);
            cboBox1.Items.Add(item); // Add each newly constructed item to our NAMED combobox.
    private ComboBoxItem CreateComboBoxItem(ComboBoxItem myCbo, string content, string name)
        Type type1 = myCbo.GetType();
        ComboBoxItem instance = (ComboBoxItem)Activator.CreateInstance(type1);
        // Here, we're using reflection to get and set the properties of the type.
        PropertyInfo Content = instance.GetType().GetProperty("Content", BindingFlags.Public | BindingFlags.Instance);
        PropertyInfo Name = instance.GetType().GetProperty("Name", BindingFlags.Public | BindingFlags.Instance);
        this.SetProperty<ComboBoxItem, String>(Content, instance, content);
        this.SetProperty<ComboBoxItem, String>(Name, instance, name);

        return instance;
        //PropertyInfo prop = type.GetProperties(rb1);

Note: This is using reflection. If you'd like to learn more about the basics of reflection and why you might want to use it, this is a great introductory article:

If you'd like to learn more about how you might use reflection with WPF specifically, here are some resources:

And if you want to massively speed up the performance of reflection, it's best to use IL to do that, like this:

Method with a bool return

private bool CheckAll()
    if ( ....)
        return true;

    return false;

When the if-condition is false the method doesn't know what value should be returned (you probably get an error like "not all paths return a value").

As CQQL pointed out if you mean to return true when your if-condition is true you could have simply written:

private bool CheckAll()
    return (your_condition);

If you have side effects, and you want to handle them before you return, the first (long) version would be required.

time.sleep -- sleeps thread or process?

It blocks the thread. If you look in Modules/timemodule.c in the Python source, you'll see that in the call to floatsleep(), the substantive part of the sleep operation is wrapped in a Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW_THREADS block, allowing other threads to continue to execute while the current one sleeps. You can also test this with a simple python program:

import time
from threading import Thread

class worker(Thread):
    def run(self):
        for x in xrange(0,11):
            print x

class waiter(Thread):
    def run(self):
        for x in xrange(100,103):
            print x

def run():

Which will print:

>>> 1

How can I set up an editor to work with Git on Windows?

I'm using GitHub for Windows which is a nice visual option. But I also prefer the command line, so to make it work when I open a repository in a Git shell I just set the following:

git config --global core.editor vim

which works great.

Can I use Class.newInstance() with constructor arguments?

I think this is exactly what you want

Although it seems a dead thread, someone might find it useful

How do I search for names with apostrophe in SQL Server?

Compare Names containing apostrophe in DB through Java code

String sql="select lastname  from employee where FirstName like '%"+firstName.trim().toLowerCase().replaceAll("'", "''")+"%'"

statement = conn.createStatement();

iterate the results.

variable or field declared void

This is not actually a problem with the function being "void", but a problem with the function parameters. I think it's just g++ giving an unhelpful error message.

EDIT: As in the accepted answer, the fix is to use std::string instead of just string.

Compiling/Executing a C# Source File in Command Prompt

I have written a batch file CompileCS.cmd which allows to compile (and optionally run) a C# file, you can find the complete answer including the batch program 'CompileCS' here.

Its usage is simple:

CompileCS /run GetDotNetVersion.cs[arg1] ... [arg9]

will compile and run GetDotNetVersion.cs - if you just want to compile it, omit the /run parameter.

The console application GetDotNetVersion.cs is taken from this answer.

Simplest way to serve static data from outside the application server in a Java web application

If you decide to dispatch to FileServlet then you will also need allowLinking="true" in context.xml in order to allow FileServlet to traverse the symlinks.


How do you discover model attributes in Rails?


Source: blog

How to go from Blob to ArrayBuffer

Just to complement Mr @potatosalad answer.

You don't actually need to access the function scope to get the result on the onload callback, you can freely do the following on the event parameter:

var arrayBuffer;
var fileReader = new FileReader();
fileReader.onload = function(event) {
    arrayBuffer =;

Why this is better? Because then we may use arrow function without losing the context

var fileReader = new FileReader();
fileReader.onload = (event) => {
    this.externalScopeVariable =;

Modify property value of the objects in list using Java 8 streams

just for modifying certain property from object collection you could directly use forEach with a collection as follows

collection.forEach(c -> c.setXyz(c.getXyz + "a"))

How can I send a Firebase Cloud Messaging notification without use the Firebase Console?

If you're using PHP, I recommend using the PHP SDK for Firebase: Firebase Admin SDK. For an easy configuration you can follow these steps:

Get the project credentials json file from Firebase (Initialize the sdk) and include it in your project.

Install the SDK in your project. I use composer:

composer require kreait/firebase-php ^4.35

Try any example from the Cloud Messaging session in the SDK documentation:

use Kreait\Firebase;
use Kreait\Firebase\Messaging\CloudMessage;

$messaging = (new Firebase\Factory())

$message = CloudMessage::withTarget(/* see sections below */)
    ->withNotification(Notification::create('Title', 'Body'))
    ->withData(['key' => 'value']);


bootstrap 3 tabs not working properly

for some weird reason bootstrap tabs were not working for me until i was using href like:-

<li class="nav-item"><a class="nav-link" href="#a" data-toggle="tab">First</a></li>

but it started working as soon as i replaced href with data-target like:-

<li class="nav-item"><a class="nav-link" data-target="#a" data-toggle="tab">First</a></li>

Javascript - check array for value

Try this:

// this will fix old browsers
if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function(value) {
    for (var i = 0; i < this.length; i++) {
      if (this[i] === value) {
        return i;

    return -1;

// example
if ([1, 2, 3].indexOf(2) != -1) {
  // yay!

Convert SQL Server result set into string

Both answers are valid, but don't forget to initializate the value of the variable, by default is NULL and with T-SQL:

NULL + "Any text" => NULL

It's a very common mistake, don't forget it!

Also is good idea to use ISNULL function:

SELECT @result = @result + ISNULL(StudentId + ',', '') FROM Student

How do I refresh the page in ASP.NET? (Let it reload itself by code)

Use javascript's location.reload() method.

<script type="text/javascript">
  function reloadPage()

Why is quicksort better than mergesort?

Quicksort has O(n2) worst-case runtime and O(nlogn) average case runtime. However, it’s superior to merge sort in many scenarios because many factors influence an algorithm’s runtime, and, when taking them all together, quicksort wins out.

In particular, the often-quoted runtime of sorting algorithms refers to the number of comparisons or the number of swaps necessary to perform to sort the data. This is indeed a good measure of performance, especially since it’s independent of the underlying hardware design. However, other things – such as locality of reference (i.e. do we read lots of elements which are probably in cache?) – also play an important role on current hardware. Quicksort in particular requires little additional space and exhibits good cache locality, and this makes it faster than merge sort in many cases.

In addition, it’s very easy to avoid quicksort’s worst-case run time of O(n2) almost entirely by using an appropriate choice of the pivot – such as picking it at random (this is an excellent strategy).

In practice, many modern implementations of quicksort (in particular libstdc++’s std::sort) are actually introsort, whose theoretical worst-case is O(nlogn), same as merge sort. It achieves this by limiting the recursion depth, and switching to a different algorithm (heapsort) once it exceeds logn.

display:inline vs display:block


takes the entire row(100%)of the screen ,it is always 100%of the screen size

display block example

display:inline-block takes up as much width as necessary ,it can be 1%-to 100% of the screen size

display inline-block example

that's why we have div and span

Div default styling is display block :it takes the entire width of the screen

span default styling is display:inline block :span does not start on a new line and only takes up as much width as necessary

How to Populate a DataTable from a Stored Procedure

You don't need to add the columns manually. Just use a DataAdapter and it's simple as:

DataTable table = new DataTable();
using(var con = new SqlConnection(ConfigurationManager.ConnectionStrings["DB"].ConnectionString))
using(var cmd = new SqlCommand("usp_GetABCD", con))
using(var da = new SqlDataAdapter(cmd))
   cmd.CommandType = CommandType.StoredProcedure;

Note that you even don't need to open/close the connection. That will be done implicitly by the DataAdapter.

The connection object associated with the SELECT statement must be valid, but it does not need to be open. If the connection is closed before Fill is called, it is opened to retrieve data, then closed. If the connection is open before Fill is called, it remains open.

How to display a list using ViewBag

     //controller  You can use this way

    public ActionResult Index()
      List<Fund> fundList = db.Funds.ToList();
     ViewBag.Funds = fundList;
        return View();

<--View ; You can use this way html-->

@foreach (var item in (List<Fund>)ViewBag.Funds)

Compare data of two Excel Columns A & B, and show data of Column A that do not exist in B

All values of column A that are not present in column B will have a red background. Hope that it helps as starting point.

Sub highlight_missings()
Dim i As Long, lastA As Long, lastB As Long
Dim compare As Variant
lastA = Range("A65536").End(xlUp).Row
lastB = Range("B65536").End(xlUp).Row

For i = 2 To lastA
    compare = Application.Match(Range("a" & i), Range("B2:B" & lastB), 0)
        If IsError(compare) Then
            Range("A" & i).Interior.ColorIndex = 3
        End If
Next i
End Sub

Error: The type exists in both directories

Try cleaning your solution and then try to rebuild. Visual Studio probably still has reference to the old dll after it created the new dll.

What is the difference between vmalloc and kmalloc?

On a 32-bit system, kmalloc() returns the kernel logical address (its a virtual address though) which has the direct mapping (actually with constant offset) to physical address. This direct mapping ensures that we get a contiguous physical chunk of RAM. Suited for DMA where we give only the initial pointer and expect a contiguous physical mapping thereafter for our operation.

vmalloc() returns the kernel virtual address which in turn might not be having a contiguous mapping on physical RAM. Useful for large memory allocation and in cases where we don't care about that the memory allocated to our process is continuous also in Physical RAM.

What is difference between CrudRepository and JpaRepository interfaces in Spring Data JPA?

Below are the differences between CrudRepository and JpaRepository as:


  1. CrudRepository is a base interface and extends the Repository interface.
  2. CrudRepository mainly provides CRUD (Create, Read, Update, Delete) operations.
  3. Return type of saveAll() method is Iterable.
  4. Use Case - To perform CRUD operations, define repository extending CrudRepository.


  1. JpaRepository extends PagingAndSortingRepository that extends CrudRepository.
  2. JpaRepository provides CRUD and pagination operations, along with additional methods like flush(), saveAndFlush(), and deleteInBatch(), etc.
  3. Return type of saveAll() method is a List.
  4. Use Case - To perform CRUD as well as batch operations, define repository extends JpaRepository.

How to write multiple conditions of if-statement in Robot Framework

The below code worked fine:

Run Keyword if    '${value1}' \ \ == \ \ '${cost1}' \ and \ \ '${value2}' \ \ == \ \ 'cost2'    LOG    HELLO

How to cast the size_t to double or int C++

If your code is prepared to deal with overflow errors, you can throw an exception if data is too large.

size_t data = 99999999;
if ( data > INT_MAX )
   throw std::overflow_error("data is larger than INT_MAX");
int convertData = static_cast<int>(data);

Assign variable value inside if-statement

Variables can be assigned but not declared inside the conditional statement:

int v;
if((v = someMethod()) != 0) return true;

How to compare two List<String> to each other?

You could also use Except(produces the set difference of two sequences) to check whether there's a difference or not:

IEnumerable<string> inFirstOnly = a1.Except(a2);
IEnumerable<string> inSecondOnly = a2.Except(a1);
bool allInBoth = !inFirstOnly.Any() && !inSecondOnly.Any();

So this is an efficient way if the order and if the number of duplicates does not matter(as opposed to the accepted answer's SequenceEqual). Demo: Ideone

If you want to compare in a case insentive way, just add StringComparer.OrdinalIgnoreCase:

a1.Except(a2, StringComparer.OrdinalIgnoreCase)

set pythonpath before import statements

As also noted in the docs here.
Go to Python X.X/Lib and add these lines to the there,

import sys

This changes your sys.path so that on every load, it will have that value in it..

As stated here about,

This module is automatically imported during initialization. Importing this module will append site-specific paths to the module search path and add a few builtins.

For other possible methods of adding some path to sys.path see these docs

What is the difference between include and require in Ruby?

  • Ruby require is more like "include" in other languages (such as C). It tells Ruby that you want to bring in the contents of another file. Similar mechanisms in other languages are:

  • Ruby include is an object-oriented inheritance mechanism used for mixins.

There is a good explanation here:

[The] simple answer is that require and include are essentially unrelated.

"require" is similar to the C include, which may cause newbie confusion. (One notable difference is that locals inside the required file "evaporate" when the require is done.)

The Ruby include is nothing like the C include. The include statement "mixes in" a module into a class. It's a limited form of multiple inheritance. An included module literally bestows an "is-a" relationship on the thing including it.

Emphasis added.

How to set max and min value for Y axis

For chart.js V2 (beta), use:

var options = {
    scales: {
        yAxes: [{
            display: true,
            ticks: {
                suggestedMin: 0,    // minimum will be 0, unless there is a lower value.
                // OR //
                beginAtZero: true   // minimum value will be 0.

See chart.js documentation on linear axes configuration for more details.

How do I force detach Screen from another SSH session?

Short answer

  1. Reattach without ejecting others: screen -x
  2. Get list of displays: ^A *, select the one to disconnect, press d

Explained answer

Background: When I was looking for the solution with same problem description, I have always landed on this answer. I would like to provide more sensible solution. (For example: the other attached screen has a different size and a I cannot force resize it in my terminal.)

Note: PREFIX is usually ^A = ctrl+a

Note: the display may also be called:

  • "user front-end" (in at command manual in screen)
  • "client" (tmux vocabulary where this functionality is detach-client)
  • "terminal" (as we call the window in our user interface) /depending on

1. Reattach a session: screen -x

-x attach to a not detached screen session without detaching it

2. List displays of this session: PREFIX *

It is the default key binding for: PREFIX :displays. Performing it within the screen, identify the other display we want to disconnect (e.g. smaller size). (Your current display is displayed in brighter color/bold when not selected).

term-type   size         user interface           window       Perms
---------- ------- ---------- ----------------- ----------     -----
 screen     240x60         you@/dev/pts/2      nb  0(zsh)        rwx
 screen      78x40         you@/dev/pts/0      nb  0(zsh)        rwx

Using arrows ? ?, select the targeted display, press d If nothing happens, you tried to detach your own display and screen will not detach it. If it was another one, within a second or two, the entry will disappear.

Press ENTER to quit the listing.

Optionally: in order to make the content fit your screen, reflow: PREFIX F (uppercase F)

Excerpt from man page of screen:


Shows a tabular listing of all currently connected user front-ends (displays). This is most useful for multiuser sessions. The following keys can be used in displays list:

  • mouseclick Move to the selected line. Available when "mousetrack" is set to on.
  • space Refresh the list
  • d Detach that display
  • D Power detach that display
  • C-g, enter, or escape Exit the list

What is the syntax for adding an element to a scala.collection.mutable.Map?

var map:Map[String, String] = Map()

var map1 = map + ("red" -> "#FF0000")


ImportError: DLL load failed: The specified module could not be found

For Windows 10 x64 and Python:

Open a Visual Studio x64 command prompt, and use dumpbin:

dumpbin /dependents [Python Module DLL or PYD file]

If you do not have Visual Studio installed, it is possible to download dumpbin elsewhere, or use another utility such as Dependency Walker.

Note that all other answers (to date) are simply random stabs in the dark, whereas this method is closer to a sniper rifle with night vision.

Case study 1

  1. I switched on Address Sanitizer for a Python module that I wrote using C++ using MSVC and CMake.

  2. It was giving this error: ImportError: DLL load failed: The specified module could not be found

  3. Opened a Visual Studio x64 command prompt.

  4. Under Windows, a .pyd file is a .dll file in disguise, so we want to run dumpbin on this file.

  5. cd MyLibrary\build\\Debug

  6. dumpbin /dependents MyLibrary.cp37-win_amd64.pyd which prints this:

    Microsoft (R) COFF/PE Dumper Version 14.27.29112.0
    Copyright (C) Microsoft Corporation.  All rights reserved.
    Dump of file MyLibrary.cp37-win_amd64.pyd
    File Type: DLL
      Image has the following dependencies:
         1000 .00cfg
        D6000 .data
         7000 .idata
        46000 .pdata
       341000 .rdata
        23000 .reloc
         1000 .rsrc
       856000 .text
  7. Searched for clang_rt.asan_dbg_dynamic-x86_64.dll, copied it into the same directory, problem solved.

  8. Alternatively, could update the environment variable PATH to point to the directory with the missing .dll.

Please feel free to add your own case studies here! I've made it a community wiki answer.

MySQL - How to parse a string value to DATETIME format inside an INSERT statement?

Use MySQL's STR_TO_DATE() function to parse the string that you're attempting to insert:

INSERT INTO tblInquiry (fldInquiryReceivedDateTime) VALUES
  (STR_TO_DATE('5/15/2012 8:06:26 AM', '%c/%e/%Y %r'))

Flutter command not found

if u meet this error in macOS, and install zsh, I am solved in this way

  1. in .zshrc file
  2. export path dont use ~/xxx/bin, use /xxx/xxx/xxxx/bin
  3. source .zshrc

How do you convert a C++ string to an int?

in "stdapi.h"


This function tells you the result, and how many characters participated in the conversion.

SQL: How to get the count of each distinct value in a column?

  COUNT(*) AS `num`

Styling an anchor tag to look like a submit button


<a href="#" class="button"> HOME </a>


.button { 
         background-color: #00CCFF;
         padding: 8px 16px;
         display: inline-block;
         text-decoration: none;
         color: #FFFFFF;
         border-radius: 3px;
.button:hover{ background-color: #0066FF;}

Watch the tutorial

Custom height Bootstrap's navbar

your markup was a bit messed up. Here's the styles you need and proper html


.navbar-nav li a {
    line-height: 150px;
    height: 150px;
    padding-top: 0;


<nav class="navbar navbar-default">
    <div class="navbar-header">
        <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>

        <a class="navbar-brand" href="#"><img src="img/logo.png" /></a>

    <div class="collapse navbar-collapse">
        <ul class="nav navbar-nav">
            <li><a href="">Portfolio</a></li>
            <li><a href="">Blog</a></li>
            <li><a href="">Contact</a></li>

Or check out the fiddle at:

How to hide Bootstrap modal with javascript?

I use Bootstrap 3.4 For me this does not work


In desperation,I did this:


Maybe it's not elegant, but it works

Using Git with Visual Studio

In Jan 2013, Microsoft announced that they are adding full Git support into all their ALM products. They have published a plugin for Visual Studio 2012 that adds Git source control integration.

Alternatively, there is a project called Git Extensions that includes add-ins for Visual Studio 2005, 2008, 2010 and 2012, as well as Windows Explorer integration. It's regularly updated and having used it on a couple of projects, I've found it very useful.

Another option is Git Source Control Provider.

Removing packages installed with go get


goclean() {
 local pkg=$1; shift || return 1
 local ost
 local cnt
 local scr

 # Clean removes object files from package source directories (ignore error)
 go clean -i $pkg &>/dev/null

 # Set local variables
 [[ "$(uname -m)" == "x86_64" ]] \
 && ost="$(uname)";ost="${ost,,}_amd64" \
 && cnt="${pkg//[^\/]}"

 # Delete the source directory and compiled package directory(ies)
 if (("${#cnt}" == "2")); then
  rm -rf "${GOPATH%%:*}/src/${pkg%/*}"
  rm -rf "${GOPATH%%:*}/pkg/${ost}/${pkg%/*}"
 elif (("${#cnt}" > "2")); then
  rm -rf "${GOPATH%%:*}/src/${pkg%/*/*}"
  rm -rf "${GOPATH%%:*}/pkg/${ost}/${pkg%/*/*}"

 # Reload the current shell
 source ~/.bashrc


# Either launch a new terminal and copy `goclean` into the current shell process, 
# or create a shell script and add it to the PATH to enable command invocation with bash.


Add a column to existing table and uniquely number them on MS SQL Server

Just using an ALTER TABLE should work. Add the column with the proper type and an IDENTITY flag and it should do the trick

Check out this MSDN article on the ALTER TABLE syntax

Error: unexpected symbol/input/string constant/numeric constant/SPECIAL in my code

These errors mean that the R code you are trying to run or source is not syntactically correct. That is, you have a typo.

To fix the problem, read the error message carefully. The code provided in the error message shows where R thinks that the problem is. Find that line in your original code, and look for the typo.

Prophylactic measures to prevent you getting the error again

The best way to avoid syntactic errors is to write stylish code. That way, when you mistype things, the problem will be easier to spot. There are many R style guides linked from the SO R tag info page. You can also use the formatR package to automatically format your code into something more readable. In RStudio, the keyboard shortcut CTRL + SHIFT + A will reformat your code.

Consider using an IDE or text editor that highlights matching parentheses and braces, and shows strings and numbers in different colours.

Common syntactic mistakes that generate these errors

Mismatched parentheses, braces or brackets

If you have nested parentheses, braces or brackets it is very easy to close them one too many or too few times.

## Error: unexpected '}' in "{}}"
{{}} # OK

Missing * when doing multiplication

This is a common mistake by mathematicians.

Error: unexpected symbol in "5x"
5*x # OK

Not wrapping if, for, or return values in parentheses

This is a common mistake by MATLAB users. In R, if, for, return, etc., are functions, so you need to wrap their contents in parentheses.

if x > 0 {}
## Error: unexpected symbol in "if x"
if(x > 0) {} # OK

Not using multiple lines for code

Trying to write multiple expressions on a single line, without separating them by semicolons causes R to fail, as well as making your code harder to read.

x + 2 y * 3
## Error: unexpected symbol in "x + 2 y"
x + 2; y * 3 # OK

else starting on a new line

In an if-else statement, the keyword else must appear on the same line as the end of the if block.

if(TRUE) 1
else 2
## Error: unexpected 'else' in "else"    
if(TRUE) 1 else 2 # OK
} else            # also OK

= instead of ==

= is used for assignment and giving values to function arguments. == tests two values for equality.

if(x = 0) {}
## Error: unexpected '=' in "if(x ="    
if(x == 0) {} # OK

Missing commas between arguments

When calling a function, each argument must be separated by a comma.

c(1 2)
## Error: unexpected numeric constant in "c(1 2"
c(1, 2) # OK

Not quoting file paths

File paths are just strings. They need to be wrapped in double or single quotes.

## Error: unexpected ')' in "path.expand(~)"
path.expand("~") # OK

Quotes inside strings

This is a common problem when trying to pass quoted values to the shell via system, or creating quoted xPath or sql queries.

Double quotes inside a double quoted string need to be escaped. Likewise, single quotes inside a single quoted string need to be escaped. Alternatively, you can use single quotes inside a double quoted string without escaping, and vice versa.

## Error: unexpected symbol in ""x"y"   
"x\"y" # OK
'x"y'  # OK  

Using curly quotes

So-called "smart" quotes are not so smart for R programming.

## Error: unexpected input in "path.expand(“"    
path.expand("~") # OK

Using non-standard variable names without backquotes

?make.names describes what constitutes a valid variable name. If you create a non-valid variable name (using assign, perhaps), then you need to access it with backquotes,

assign("x y", 0)
x y
## Error: unexpected symbol in "x y"
`x y` # OK

This also applies to column names in data frames created with check.names = FALSE.

dfr <- data.frame("x y" = 1:5, check.names = FALSE)
dfr$x y
## Error: unexpected symbol in "dfr$x y"
dfr[,"x y"] # OK
dfr$`x y`   # also OK

It also applies when passing operators and other special values to functions. For example, looking up help on %in%.

## Error: unexpected SPECIAL in "?%in%"
?`%in%` # OK

Sourcing non-R code

The source function runs R code from a file. It will break if you try to use it to read in your data. Probably you want read.table.

source(textConnection("x y"))
## Error in source(textConnection("x y")) : 
##   textConnection("x y"):1:3: unexpected symbol
## 1: x y
##       ^

Corrupted RStudio desktop file

RStudio users have reported erroneous source errors due to a corrupted .rstudio-desktop file. These reports only occurred around March 2014, so it is possibly an issue with a specific version of the IDE. RStudio can be reset using the instructions on the support page.

Using expression without paste in mathematical plot annotations

When trying to create mathematical labels or titles in plots, the expression created must be a syntactically valid mathematical expression as described on the ?plotmath page. Otherwise the contents should be contained inside a call to paste.

plot(rnorm(10), ylab = expression(alpha ^ *)))
## Error: unexpected '*' in "plot(rnorm(10), ylab = expression(alpha ^ *"
plot(rnorm(10), ylab = expression(paste(alpha ^ phantom(0), "*"))) # OK

Android scale animation on view

Here is a code snip to do exactly that.

public void scaleView(View v, float startScale, float endScale) {
    Animation anim = new ScaleAnimation(
            1f, 1f, // Start and end values for the X axis scaling
            startScale, endScale, // Start and end values for the Y axis scaling
            Animation.RELATIVE_TO_SELF, 0f, // Pivot point of X scaling
            Animation.RELATIVE_TO_SELF, 1f); // Pivot point of Y scaling
    anim.setFillAfter(true); // Needed to keep the result of the animation

The ScaleAnimation constructor used here takes 8 args, 4 related to handling the X-scale which we don't care about (1f, 1f, ... Animation.RELATIVE_TO_SELF, 0f, ...).

The other 4 args are for the Y-scaling we do care about.

startScale, endScale - In your case, you'd use 0f, 0.6f.

Animation.RELATIVE_TO_SELF, 1f - This specifies where the shrinking of the view collapses to (referred to as the pivot in the documentation). Here, we set the float value to 1f because we want the animation to start growing the bar from the bottom. If we wanted it to grow downward from the top, we'd use 0f.

Finally, and equally important, is the call to anim.setFillAfter(true). If you want the result of the animation to stick around after the animation completes, you must run this on the animator before executing the animation.

So in your case, you can do something like this:

View v = findViewById(;
scaleView(v, 0f, .6f);

LINQ - Left Join, Group By, and Count

from p in context.ParentTable
join c in context.ChildTable on p.ParentId equals c.ChildParentId into j1
from j2 in j1.DefaultIfEmpty()
group j2 by p.ParentId into grouped
select new { ParentId = grouped.Key, Count = grouped.Count(t=>t.ChildId != null) }

How are echo and print different in PHP?

As the manual suggests, take a read of this discussion.

One major difference is that echo can take multiple parameters to output. E.g.:

echo 'foo', 'bar';   // Concatenates the 2 strings
print('foo', 'bar'); // Fatal error

If you're looking to evaluate the outcome of an output statement (as below) use print. If not, use echo.

$res = print('test');
var_dump($res); //bool(true)

How do I prevent Conda from activating the base environment by default?

There're 3 ways to achieve this after conda 4.6. (The last method has the highest priority.)

  1. Use sub-command conda config to change the setting.

    conda config --set auto_activate_base false
  2. In fact, the former conda config sub-command is changing configuration file .condarc. We can modify .condarc directly. Add following content into .condarc under your home directory,

    # auto_activate_base (bool)
    #   Automatically activate the base environment during shell
    #   initialization. for `conda init`
    auto_activate_base: false
  3. Set environment variable CONDA_AUTO_ACTIVATE_BASE in the shell's init file. (.bashrc for bash, .zshrc for zsh)


    To convert from the condarc file-based configuration parameter name to the environment variable parameter name, make the name all uppercase and prepend CONDA_. For example, conda’s always_yes configuration parameter can be specified using a CONDA_ALWAYS_YES environment variable.

    The environment settings take precedence over corresponding settings in .condarc file.



You Could try the other format for the case statement

CASE WHEN Product.type_id = 10
  Select Statement
  Other select statement

FROM Product 
WHERE Product.product_id = $pid

See for more information.

Makefiles with source files in different directories

You can add rules to your root Makefile in order to compile the necessary cpp files in other directories. The Makefile example below should be a good start in getting you to where you want to be.


SOURCE = cppTest.cpp
SOURCE = $(OTHERDIR)/file.cpp

## End sources definition
## end more includes

OBJ=$(join $(addsuffix ../obj/, $(dir $(SOURCE))), $(notdir $(SOURCE:.cpp=.o))) 

## Fix dependency destination to be ../.dep relative to the src dir
DEPENDS=$(join $(addsuffix ../.dep/, $(dir $(SOURCE))), $(notdir $(SOURCE:.cpp=.d)))

## Default rule executed
all: $(TARGET)

## Clean Rule
        @-rm -f $(TARGET) $(OBJ) $(DEPENDS)

## Rule for making the actual target
        @echo "============="
        @echo "Linking the target $@"
        @echo "============="
        @$(CC) $(CFLAGS) -o $@ $^ $(LIBS)
        @echo -- Link finished --

## Generic compilation rule
%.o : %.cpp
        @mkdir -p $(dir $@)
        @echo "============="
        @echo "Compiling $<"
        @$(CC) $(CFLAGS) -c $< -o $@

## Rules for object files from cpp files
## Object file for each file is put in obj directory
## one level up from the actual source directory.
../obj/%.o : %.cpp
        @mkdir -p $(dir $@)
        @echo "============="
        @echo "Compiling $<"
        @$(CC) $(CFLAGS) -c $< -o $@

# Rule for "other directory"  You will need one per "other" dir
$(OTHERDIR)/../obj/%.o : %.cpp
        @mkdir -p $(dir $@)
        @echo "============="
        @echo "Compiling $<"
        @$(CC) $(CFLAGS) -c $< -o $@

## Make dependancy rules
../.dep/%.d: %.cpp
        @mkdir -p $(dir $@)
        @echo "============="
        @echo Building dependencies file for $*.o
        @$(SHELL) -ec '$(CC) -M $(CFLAGS) $< | sed "s^$*.o^../obj/$*.o^" > $@'

## Dependency rule for "other" directory
$(OTHERDIR)/../.dep/%.d: %.cpp
        @mkdir -p $(dir $@)
        @echo "============="
        @echo Building dependencies file for $*.o
        @$(SHELL) -ec '$(CC) -M $(CFLAGS) $< | sed "s^$*.o^$(OTHERDIR)/../obj/$*.o^" > $@'

## Include the dependency files
-include $(DEPENDS)

Error #2032: Stream Error

Just to clarify my comment (it's illegible in a single line)

I think the best answer is the comment by Mike Chambers in this link ( by Hunter McMillen.

A note from Mike Chambers:

If you run into this using URLLoader, listen for the:

and in AIR :

It should give you some more information (such as the status code being returned from the server).

How do I see active SQL Server connections?

Click the "activity monitor" icon in the toolbar.

From Thorsten's comment:

In SQL Server Management Studio, right click on Server, choose "Activity Monitor" from context menu -or- use keyboard shortcut Ctrl + Alt + A.

Reference: Microsoft Docs - Open Activity Monitor in SQL Server Management Studio (SSMS)

How can I export Excel files using JavaScript?

Create an AJAX postback method which writes a CSV file to your webserver and returns the url.. Set a hidden IFrame in the browser to the location of the CSV file on the server.

Your user will then be presented with the CSV download link.

How to open Console window in Eclipse?

The only reliable way to open it is Window -> Show View -> Other -> Search "console". There was a handful suggestions in this post and none of them works! Apparently Eclipse likes to change their logic every other second.

Also, resetting the view is the most horrible suggestion, because that way you will lose everything you have ever done to change the layout, so it will probably not work for the most of the readers.

Image convert to Base64

Exactly what you need:) You can choose callback version or Promise version. Note that promises will work in IE only with Promise polyfill lib.You can put this code once on a page, and this function will appear in all your files.

The loadend event is fired when progress has stopped on the loading of a resource (e.g. after "error", "abort", or "load" have been dispatched)

Callback version

        File.prototype.convertToBase64 = function(callback){
                var reader = new FileReader();
                reader.onloadend = function (e) {

          var selectedFile = this.files[0];

Promise version

    File.prototype.convertToBase64 = function(){
         return new Promise(function(resolve, reject) {
                var reader = new FileReader();
                reader.onloadend = function (e) {

    FileList.prototype.convertAllToBase64 = function(regexp){
      // empty regexp if not set
      regexp = regexp || /.*/;
      //making array from FileList
      var filesArray =;
      var base64PromisesArray = filesArray.
             return (regexp).test(
             return file.convertToBase64();
      return Promise.all(base64PromisesArray);

      //for one file
      var selectedFile = this.files[0];
      //for all files that have file extention png, jpeg, jpg, gif
            objArray.forEach(function(obj, i){
                  console.log("result[" + obj.fileName + "][" + i + "] = " + obj.result);


<input type="file" id="asd" multiple/>

React-Router External link

If you are using server side rending, you can use StaticRouter. With your context as props and then adding <Redirect path="/somewhere" /> component in your app. The idea is everytime react-router matches a redirect component it will add something into the context you passed into the static router to let you know your path matches a redirect component. now that you know you hit a redirect you just need to check if thats the redirect you are looking for. then just redirect through the server. ctx.redirect('https://example/com').

How to concatenate int values in java?

NOTE: when you try to use + operator on (string + int) it converts int into strings and concatnates them ! so you need to convert only one int to string

public class scratch {

public static void main(String[] args){

    int a=1;
    int b=0;
    int c=2;
    int d=2;
    int e=1;
    System.out.println( String.valueOf(a)+b+c+d+e) ;

python: create list of tuples from lists

You're looking for the zip builtin function. From the docs:

>>> x = [1, 2, 3]
>>> y = [4, 5, 6]
>>> zipped = zip(x, y)
>>> zipped
[(1, 4), (2, 5), (3, 6)]

Reading rows from a CSV file in Python


import pandas as pd

data = pd.read_csv('data.csv')

# read row line by line
for d in data.values:
  # read column by index

How to get access token from FB.login method in javascript SDK

response.session.access_token doesn't work in my code. But this works: response.authResponse.accessToken

     FB.login(function(response) { alert(response.authResponse.accessToken);
     }, {perms:'read_stream,publish_stream,offline_access'});

Remove a folder from git tracking

I know this is an old thread but I just wanted to add a little as the marked solution didn't solve the problem for me (although I tried many times).

The only way I could actually stop git form tracking the folder was to do the following:

  1. Make a backup of the local folder and put in a safe place.
  2. Delete the folder from your local repo
  3. Make sure cache is cleared git rm -r --cached your_folder/
  4. Add your_folder/ to .gitignore
  5. Commit changes
  6. Add the backup back into your repo

You should now see that the folder is no longer tracked.

Don't ask me why just clearing the cache didn't work for me, I am not a Git super wizard but this is how I solved the issue.

Missing Maven dependencies in Eclipse project

Below solution worked for me -
1- Go to project directory
2- run mvn eclipse:eclipse (Hope mvn is added in your path)
3- run mvn clean install

Refresh your project in Eclipse and check.

How to export data from Excel spreadsheet to Sql Server 2008 table

From your SQL Server Management Studio, you open Object Explorer, go to your database where you want to load the data into, right click, then pick Tasks > Import Data.

This opens the Import Data Wizard, which typically works pretty well for importing from Excel. You can pick an Excel file, pick what worksheet to import data from, you can choose what table to store it into, and what the columns are going to be. Pretty flexible indeed.

You can run this as a one-off, or you can store it as a SQL Server Integration Services (SSIS) package into your file system, or into SQL Server itself, and execute it over and over again (even scheduled to run at a given time, using SQL Agent).

Update: yes, yes, yes, you can do all those things you keep asking - have you even tried at least once to run that wizard??

OK, here it comes - step by step:

Step 1: pick your Excel source

enter image description here

Step 2: pick your SQL Server target database

enter image description here

Step 3: pick your source worksheet (from Excel) and your target table in your SQL Server database; see the "Edit Mappings" button!

enter image description here

Step 4: check (and change, if needed) your mappings of Excel columns to SQL Server columns in the table:

enter image description here

Step 5: if you want to use it later on, save your SSIS package to SQL Server:

enter image description here

Step 6: - success! This is on a 64-bit machine, works like a charm - just do it!!

Android how to use Environment.getExternalStorageDirectory()

Have in mind though, that getExternalStorageDirectory() is not going to work properly on some phones e.g. my Motorola razr maxx, as it has 2 cards /mnt/sdcard and /mnt/sdcard-ext - for internal and external SD cards respectfully. You will be getting the /mnt/sdcard only reply every time. Google must provide a way to deal with such a situation. As it renders many SD card aware apps (i.e card backup) failing miserably on these phones.

Expansion of variables inside single quotes in a command in Bash

Below is what worked for me -

hive -e "alter table TBL_NAME set location $QUOTE$TBL_HDFS_DIR_PATH$QUOTE"

Get: TypeError: 'dict_values' object does not support indexing when using python 3.2.3

In Python 3 the dict.values() method returns a dictionary view object, not a list like it does in Python 2. Dictionary views have a length, can be iterated, and support membership testing, but don't support indexing.

To make your code work in both versions, you could use either of these:

{names[i]:value for i,value in enumerate(d.values())}


values = list(d.values())
{name:values[i] for i,name in enumerate(names)}

By far the simplest, fastest way to do the same thing in either version would be:

dict(zip(names, d.values()))

Note however, that all of these methods will give you results that will vary depending on the actual contents of d. To overcome that, you may be able use an OrderedDict instead, which remembers the order that keys were first inserted into it, so you can count on the order of what is returned by the values() method.

How to add "active" class to Html.ActionLink in ASP.NET MVC

Add '.ToString' to improve comparing on ASP.NET MVC

<ul class="nav navbar-nav">
<li class="@(ViewContext.RouteData.Values["Action"].ToString() == "Index" ? "active" : "")">@Html.ActionLink("Home", "Index", "Home")</li>
<li class="@(ViewContext.RouteData.Values["Action"].ToString() == "About" ? "active" : "")">@Html.ActionLink("About", "About", "Home")</li>
<li class="@(ViewContext.RouteData.Values["Action"].ToString() == "Contact" ? "active" : "")">@Html.ActionLink("Contact", "Contact", "Home")</li>


Extracting specific selected columns to new DataFrame as a copy

columns by index:

# selected column index: 1, 6, 7
new = old.iloc[: , [1, 6, 7]].copy() 

Android: How to enable/disable option menu item on button click?

On all android versions, easiest way: use this to SHOW a menu action icon as disabled AND make it FUNCTION as disabled as well:

public boolean onPrepareOptionsMenu(Menu menu) {

    MenuItem item = menu.findItem(;

    if (myItemShouldBeEnabled) {
    } else {
        // disabled

What is the intended use-case for git stash?

I know StackOverflow is not the place for opinion based answers, but I actually have a good opinion on when to shelve changes with a stash.

You don't want to commit you experimental changes

When you make changes in your workspace/working tree, if you need to perform any branch based operations like a merge, push, fetch or pull, you must be at a clean commit point. So if you have workspace changes you need to commit them. But what if you don't want to commit them? What if they are experimental? Something you don't want part of your commit history? Something you don't want others to see when you push to GitHub?

You don't want to lose local changes with a hard reset

In that case, you can do a hard reset. But if you do a hard reset you will lose all of your local working tree changes because everything gets overwritten to where it was at the time of the last commit and you'll lose all of your changes.

So, as for the answer of 'when should you stash', the answer is when you need to get back to a clean commit point with a synchronized working tree/index/commit, but you don't want to lose your local changes in the process. Just shelve your changes in a stash and you're good.

And once you've done your stash and then merged or pulled or pushed, you can just stash pop or apply and you're back to where you started from.

Git stash and GitHub

GitHub is constantly adding new features, but as of right now, there is now way to save a stash there. Again, the idea of a stash is that it's local and private. Nobody else can peek into your stash without physical access to your workstation. Kinda the same way git reflog is private with the git log is public. It probably wouldn't be private if it was pushed up to GitHub.

One trick might be to do a diff of your workspace, check the diff into your git repository, commit and then push. Then you can do a pull from home, get the diff and then unwind it. But that's a pretty messy way to achieve those results.

git diff > git-dif-file.diff

pop the stash

Unbound classpath container in Eclipse

I had the same problem even after installing JDK 1.7. I corrected it by adding the bin directory to my PATH. So I went to

computer>properties>advanced>environment variables

and then added

C:\Program Files\Java\jdk1.7.0_55\bin;

then I followed these instructions

Using querySelectorAll to retrieve direct children

Here's a flexible method, written in vanilla JS, that allows you to run a CSS selector query over only the direct children of an element:

var count = 0;
function queryChildren(element, selector) {
  var id =,
      guid = = id || 'query_children_' + count++,
      attr = '#' + guid + ' > ',
      selector = attr + (selector + '').replace(',', ',' + attr, 'g');
  var result = element.parentNode.querySelectorAll(selector);
  if (!id) element.removeAttribute('id');
  return result;

Convert UTF-8 to base64 string

It's a little difficult to tell what you're trying to achieve, but assuming you're trying to get a Base64 string that when decoded is abcdef==, the following should work:

byte[] bytes = Encoding.UTF8.GetBytes("abcdef==");
string base64 = Convert.ToBase64String(bytes);

This will output: YWJjZGVmPT0= which is abcdef== encoded in Base64.


To decode a Base64 string, simply use Convert.FromBase64String(). E.g.

string base64 = "YWJjZGVmPT0=";
byte[] bytes = Convert.FromBase64String(base64);

At this point, bytes will be a byte[] (not a string). If we know that the byte array represents a string in UTF8, then it can be converted back to the string form using:

string str = Encoding.UTF8.GetString(bytes);

This will output the original input string, abcdef== in this case.

Does Index of Array Exist

You can rather use a List, so you can check the existence.

List<int> l = new List<int>();

if (l.Count == 25) {
int num = 45;
if (l.Contains(num)) {

Generate a unique id

Why can't we make a unique id as below.

We can use DateTime.Now.Ticks and Guid.NewGuid().ToString() to combine together and make a unique id.

As the DateTime.Now.Ticks is added, we can find out the Date and Time in seconds at which the unique id is created.

Please see the code.

var ticks = DateTime.Now.Ticks;
var guid = Guid.NewGuid().ToString();
var uniqueSessionId = ticks.ToString() +'-'+ guid; //guid created by combining ticks and guid

var datetime = new DateTime(ticks);//for checking purpose
var datetimenow = DateTime.Now;    //both these date times are different.

We can even take the part of ticks in unique id and check for the date and time later for future reference.

raw_input function in Python

The "input" function converts the input you enter as if it were python code. "raw_input" doesn't convert the input and takes the input as it is given. Its advisable to use raw_input for everything. Usage:

>>a = raw_input()

How to add a custom HTTP header to every WCF call?

If you want to add custom HTTP headers to every WCF call in an object oriented way, look no further.

Just as in Mark Good's and paulwhit's answer, we need to subclass IClientMessageInspector to inject the custom HTTP headers into the WCF request. However, lets make the inspector more generic by accepting an dictionary containing the headers we want to add:

public class HttpHeaderMessageInspector : IClientMessageInspector
    private Dictionary<string, string> Headers;

    public HttpHeaderMessageInspector(Dictionary<string, string> headers)
        Headers = headers;

    public object BeforeSendRequest(ref Message request, IClientChannel channel)
        // ensure the request header collection exists
        if (request.Properties.Count == 0 || request.Properties[HttpRequestMessageProperty.Name] == null)
            request.Properties.Add(HttpRequestMessageProperty.Name, new HttpRequestMessageProperty());

        // get the request header collection from the request
        var HeadersCollection = ((HttpRequestMessageProperty)request.Properties[HttpRequestMessageProperty.Name]).Headers;

        // add our headers
        foreach (var header in Headers) HeadersCollection[header.Key] = header.Value;

        return null;

    // ... other unused interface methods removed for brevity ...

Just as in Mark Good's and paulwhit's answer, we need to subclass IEndpointBehavior to inject our HttpHeaderMessageInspector into our WCF client.

public class AddHttpHeaderMessageEndpointBehavior : IEndpointBehavior
    private IClientMessageInspector HttpHeaderMessageInspector;

    public AddHttpHeaderMessageEndpointBehavior(Dictionary<string, string> headers)
        HttpHeaderMessageInspector = new HttpHeaderMessageInspector(headers);

    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)

    // ... other unused interface methods removed for brevity ...

The last part needed to finish our object oriented approach, is to create a subclass of our WCF auto-generated client (I used Microsoft's WCF Web Service Reference Guide to generate a WCF client).

In my case, I need to attach an API key to the x-api-key HTML header.

The subclass does the following:

  • calls the constructor of the base class with the required parameters (in my case a EndpointConfiguration enum was generated to pass into the constructor - maybe your implementation won't have this)
  • Defines the headers that should be attached to every requests
  • Attaches AddHttpHeaderMessageEndpointBehavior to the client's Endpoint behaviors
public class Client : MySoapClient
    public Client(string apiKey) : base(EndpointConfiguration.SomeConfiguration)
        var headers = new Dictionary<string, string>
            ["x-api-key"] = apiKey

        var behaviour = new AddHttpHeaderMessageEndpointBehavior(headers);

Finally, use your client!

var client = new Client (apiKey);
var result = client.SomeRequest()

The resulting HTTP request should contain your HTTP headers and look something like this:

POST http://localhost:8888/api/soap HTTP/1.1
Cache-Control: no-cache, max-age=0
Connection: Keep-Alive
Content-Type: text/xml; charset=utf-8
Accept-Encoding: gzip, deflate
SOAPAction: "http://localhost:8888/api/ISoapService/SomeRequest"
Content-Length: 144
Host: localhost:8888

<s:Envelope xmlns:s="">

break statement in "if else" - java

The issue is that you are trying to have multiple statements in an if without using {}. What you currently have is interpreted like:

if( choice==5 )
    System.out.println( ... );

You really want:

if( choice==5 )
    System.out.println( ... );

Also, as Farce has stated, it would be better to use else if for all the conditions instead of if because if choice==1, it will still go through and check if choice==5, which would fail, and it will still go into your else block.

if( choice==1 )
else if( choice==2 )
else if( choice==3 )
else if( choice==4 )
else if( choice==5 )

A more elegant solution would be using a switch statement. However, break only breaks from the most inner "block" unless you use labels. So you want to label your loop and break from that if the case is 5:

    System.out.println("---> Your choice: ");
    choice = input.nextInt();
    switch( choice )
        case 1:
        case 2:
        case 2:
        case 4:
        case 5:
            System.out.println("End of Game\n Thank you for playing with us!");
            break LOOP;
            System.out.println( ... );

Instead of labeling the loop, you could also use a flag to tell the loop to stop.

bool finished = false;
while( !finished )
    switch( choice )
        // ...
        case 5:
            System.out.println( ... )
            finished = true;
        // ...

error while loading shared libraries:

If you are absolutely sure that libncurses, aka ncurses, is installed, as in you've done a successful 'ls' of the library, then perhaps you are running a 64 bit Linux operating system and only have the 64 bit libncurses installed, when the program that is running (adb) is 32 bit.

If so, a 32 bit program can't link to a 64 bit library (and won't located it anyway), so you might have to install libcurses, or ncurses (32 bit version). Likewise, if you are running a 64 bit adb, perhaps your ncurses is 32 bit (a possible but less likely scenario).

Java: unable to find valid certification path to requested target

Had the issue like this image.

enter image description here

Tried a few solutions. But found that even if it's same project, when it's on other one's working place, it's totally fine. No extra settings needed. So we guessed it's an enviroment issue. We tried changing JDK version, IDE but didn't work. it took about 4 hours for investigation, until we tried the top-rated answer. I didn't find the error mentioned in that answer but I found via my browser about HTTP URL (lock) that there was a certification of Charles. Then I realized my charles was on all the time. As long as I turned that off, it's working all fine.

So I left my experience that could be helpful for your case.

Meaning of *& and **& in C++

*& signifies the receiving the pointer by reference. It means it is an alias for the passing parameter. So, it affects the passing parameter.

#include <iostream>
using namespace std;

void foo(int *ptr)
    ptr = new int(50);    // Modifying the pointer to point to a different location
    cout << "In foo:\t" << *ptr << "\n"; 
    delete ptr ;

void bar(int *& ptr)
    ptr = new int(80);    // Modifying the pointer to point to a different location
    cout << "In bar:\t" << *ptr << "\n"; 
    // Deleting the pointer will result the actual passed parameter dangling
int main()
    int temp = 100 ;
    int *p = &temp ;

    cout << "Before foo:\t" << *p << "\n";
    foo(p) ;
    cout << "After foo:\t" << *p << "\n";

    cout << "Before bar:\t" << *p << "\n";
    bar(p) ;
    cout << "After bar:\t" << *p << "\n";

    delete p;

    return 0;


Before foo: 100
In foo: 50
After foo:  100
Before bar: 100
In bar: 80
After bar:  80

Regular Expression to get all characters before "-"

I dont think you need regex to achieve this. I would look at the SubString method along with the indexOf method. If you need more help, add a comment showing what you have attempted and I will offer more help.

Java ArrayList replace at specific index

Check out the set(int index, E element) method in the List interface

What is the correct way to write HTML using Javascript?

Use jquery, look how easy it is:

    var a = '<h1> this is some html </h1>';

    <div id="results"> </div>

Histogram using gnuplot?

With respect to binning functions, I didn't expect the result of the functions offered so far. Namely, if my binwidth is 0.001, these functions were centering the bins on 0.0005 points, whereas I feel it's more intuitive to have the bins centered on 0.001 boundaries.

In other words, I'd like to have

Bin 0.001 contain data from 0.0005 to 0.0014
Bin 0.002 contain data from 0.0015 to 0.0024

The binning function I came up with is

my_bin(x,width)     = width*(floor(x/width+0.5))

Here's a script to compare some of the offered bin functions to this one:

rint(x) = (x-int(x)>0.9999)?int(x)+1:int(x)
bin(x,width)        = width*rint(x/width) + width/2.0
binc(x,width)       = width*(int(x/width)+0.5)
mitar_bin(x,width)  = width*floor(x/width) + width/2.0
my_bin(x,width)     = width*(floor(x/width+0.5))

binwidth = 0.001

data_list = "-0.1386 -0.1383 -0.1375 -0.0015 -0.0005 0.0005 0.0015 0.1375 0.1383 0.1386"

my_line = sprintf("%7s  %7s  %7s  %7s  %7s","data","bin()","binc()","mitar()","my_bin()")
print my_line
do for [i in data_list] {
    iN = i + 0
    my_line = sprintf("%+.4f  %+.4f  %+.4f  %+.4f  %+.4f",iN,bin(iN,binwidth),binc(iN,binwidth),mitar_bin(iN,binwidth),my_bin(iN,binwidth))
    print my_line

and here's the output

   data    bin()   binc()  mitar()  my_bin()
-0.1386  -0.1375  -0.1375  -0.1385  -0.1390
-0.1383  -0.1375  -0.1375  -0.1385  -0.1380
-0.1375  -0.1365  -0.1365  -0.1375  -0.1380
-0.0015  -0.0005  -0.0005  -0.0015  -0.0010
-0.0005  +0.0005  +0.0005  -0.0005  +0.0000
+0.0005  +0.0005  +0.0005  +0.0005  +0.0010
+0.0015  +0.0015  +0.0015  +0.0015  +0.0020
+0.1375  +0.1375  +0.1375  +0.1375  +0.1380
+0.1383  +0.1385  +0.1385  +0.1385  +0.1380
+0.1386  +0.1385  +0.1385  +0.1385  +0.1390

How to remove item from a JavaScript object

var test = {'red':'#FF0000', 'blue':'#0000FF'};_x000D_
delete; // or use => delete test['blue'];_x000D_

this deletes

How can a windows service programmatically restart itself?

Set the service to restart after failure (double click the service in the control panel and have a look around on those tabs - I forget the name of it). Then, anytime you want the service to restart, just call Environment.Exit(1) (or any non-zero return) and the OS will restart it for you.

Custom ImageView with drop shadow

My dirty solution:

private static Bitmap getDropShadow3(Bitmap bitmap) {

    if (bitmap==null) return null;
    int think = 6;
    int w = bitmap.getWidth();
    int h = bitmap.getHeight();

    int newW = w - (think);
    int newH = h - (think);

    Bitmap.Config conf = Bitmap.Config.ARGB_8888;
    Bitmap bmp = Bitmap.createBitmap(w, h, conf);
    Bitmap sbmp = Bitmap.createScaledBitmap(bitmap, newW, newH, false);

    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    Canvas c = new Canvas(bmp);

    // Right
    Shader rshader = new LinearGradient(newW, 0, w, 0, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    c.drawRect(newW, think, w, newH, paint);

    // Bottom
    Shader bshader = new LinearGradient(0, newH, 0, h, Color.GRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    c.drawRect(think, newH, newW  , h, paint);

    Shader cchader = new LinearGradient(0, newH, 0, h, Color.LTGRAY, Color.LTGRAY, Shader.TileMode.CLAMP);
    c.drawRect(newW, newH, w  , h, paint);

    c.drawBitmap(sbmp, 0, 0, null);

    return bmp;

result: enter image description here

Dynamically Fill Jenkins Choice Parameter With Git Branches In a Specified Repo

The following groovy script would be useful, if your job does not use "Source Code Management" directly (likewise "Git Parameter Plugin"), but still have access to a local (cloned) git repository:

import jenkins.model.Jenkins

def envVars = Jenkins.instance.getNodeProperties()[0].getEnvVars() 
def gettags = "git ls-remote -t --heads origin".execute(null, new File(GIT_PROJECT_PATH))

return gettags.text.readLines()
         .collect { it.split()[1].replaceAll('\\^\\{\\}', '').replaceAll('refs/\\w+/', '')  }

See full explanation here:

How to embed new Youtube's live video permanent URL?

Have you tried plugin called " Youtube Live Stream Auto Embed"

Its seems to be working. Check it once.

Log4j: How to configure simplest possible file logging?

Here is a file that I've used with great success.


log4j.rootLogger=INFO, stdout
#log4j.rootLogger=DEBUG, stdout

log4j.appender.stdout.layout.ConversionPattern=%d{MM/dd/yyyy hh:mm:ss a}|%-5p|%-30c{1}| %m%n

The DailyRollingFileAppender will create new files each day with file names that look like this:

myapp.log  <-- today's log

Each entry in the log file will will have this format:

01/30/2017 12:59:47 AM|INFO |Component1   | calling foobar(): userId=123, returning totalSent=1
01/30/2017 12:59:47 AM|INFO |Component2   | count=1 > 0, calling fooBar()

Set the location of the above file by using -Dlog4j.configuration, as mentioned in this posting:

java -Dlog4j.configuration=file:/home/myapp/config/ com.foobar.myapp

In your Java code, be sure to set the name of each software component when you instantiate your logger object. I also like to log to both the log file and standard output, so I wrote this small function.

private static final Logger LOGGER = Logger.getLogger("Component1");

public static void log(org.apache.log4j.Logger logger, String message) {;
    System.out.printf("%s\n", message);

public static String stackTraceToString(Exception ex) {
    StringWriter sw = new StringWriter();
    PrintWriter pw = new PrintWriter(sw);
    return sw.toString();

And then call it like so:"Exception occurred: %s", stackTraceToString(ex)));

How do I return JSON without using a template in Django?

Here's an example I needed for conditionally rendering json or html depending on the Request's Accept header

# myapp/
from django.core import serializers                                                                                
from django.http import HttpResponse                                                                                  
from django.shortcuts import render                                                                                   
from .models import Event

def event_index(request):                                                                                             
    event_list = Event.objects.all()                                                                                  
    if request.META['HTTP_ACCEPT'] == 'application/json':                                                             
        response = serializers.serialize('json', event_list)                                                          
        return HttpResponse(response, content_type='application/json')                                                
        context = {'event_list': event_list}                                                                          
        return render(request, 'polls/event_list.html', context)

you can test this with curl or httpie

$ http localhost:8000/event/
$ http localhost:8000/event/ Accept:application/json

note I opted not to use JsonReponse as that would reserialize the model unnecessarily.

JavaScript getElementByID() not working

You need to put the JavaScript at the end of the body tag.

It doesn't find it because it's not in the DOM yet!

You can also wrap it in the onload event handler like this:

window.onload = function() {
var refButton = document.getElementById( 'btnButton' );
refButton.onclick = function() {
   alert( 'I am clicked!' );

How to check if a file exists from a url

You have to use CURL

function does_url_exists($url) {
    $ch = curl_init($url);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

    if ($code == 200) {
        $status = true;
    } else {
        $status = false;
    return $status;

Python regex findall

Use this pattern,

pattern = '\[P\].+?\[\/P\]'

Check here

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

and a shortcut:

C:\Windows\System32\cmd.exe /c start shell:AppsFolder\Microsoft.MicrosoftEdge_8wekyb3d8bbwe!MicrosoftEdge http://localhost:6516

In Java what is the syntax for commenting out multiple lines?

As @kgrad says, /* */ does not nest and can cause errors. A better answer is:


Most IDEs have a single keyboard command for doing/undoing this, so there's really no reason to use the other style any more. For example: in eclipse, select the block of text and hit Ctrl+/
To undo that type of comment, use Ctrl+\

UPDATE: The Sun coding convention says that this style should not be used for block text comments:

// Using the slash-slash
// style of comment as shown
// in this paragraph of non-code text is 
// against the coding convention.

but // can be used 3 other ways:

  1. A single line comment
  2. A comment at the end of a line of code
  3. Commenting out a block of code

Using :before and :after CSS selector to insert Html

content doesn't support HTML, only text. You should probably use javascript, jQuery or something like that.

Another problem with your code is " inside a " block. You should mix ' and " (class='headingDetail').

If content did support HTML you could end up in an infinite loop where content is added inside content.

How to iterate over rows in a DataFrame in Pandas

To loop all rows in a dataframe you can use:

for x in range(len(date_example.index)):
    print date_example['Date'].iloc[x]

How to send HTML-formatted email?

This works for me

msg.BodyFormat = MailFormat.Html;

and then you can use html in your body

msg.Body = "<em>It's great to use HTML in mail!!</em>"

Use stored procedure to insert some data into a table

if you want to populate a table in SQL SERVER you can use while statement as follows:

declare @llenandoTabla INT = 0;
while @llenandoTabla < 10000
insert into employeestable // Name of my table
(ID, FIRSTNAME, LASTNAME, GENDER, SALARY) // Parameters of my table
(555, 'isaias', 'perez', 'male', '12220') //values
set @llenandoTabla = @llenandoTabla + 1;

Hope it helps.

How to delete selected text in the vi editor

Highlighting with your mouse only highlights characters on the terminal. VI doesn't really get this information, so you have to highlight differently.

Press 'v' to enter a select mode, and use arrow keys to move that around. To delete, press x. To select lines at a time, press shift+v. To select blocks, try ctrl+v. That's good for, say, inserting lots of comment lines in front of your code :).

I'm OK with VI, but it took me a while to improve. My work mates recommended me this cheat sheet. I keep a printout on the wall for those odd moments when I forget something.

Happy hacking!

What's the Kotlin equivalent of Java's String[]?

you can use too:

val frases = arrayOf("texto01","texto02 ","anotherText","and ")

for example.

View google chrome's cached pictures

%UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache

paste this in your address bar and enter, you will get all the files

just rename the files extension into the extension which u r looking.

ie. open command prompt then

C:\>cd %UserProfile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Cache


C:\Users\User\AppData\Local\Google\Chrome\User Data\Default\Cache>ren *.* *.jpg

How to allow only one radio button to be checked?

Just give them the same name throughout the form you are using.

<form><input type="radio" name="selection">
      <input type="radio" name="selection">

Find duplicate records in a table using SQL Server

with x as (
select shoppername,count(shoppername)
              from sales
              having count(shoppername)>1
            group by shoppername)
select t.* from x,win_gp_pin1510 t
where x.shoppername=t.shoppername
order by t.shoppername

Android ADB stop application command like "force-stop" for non rooted device

The first way
Needs root

Use kill:

adb shell ps => Will list all running processes on the device and their process ids
adb shell kill <PID> => Instead of <PID> use process id of your application

The second way
In Eclipse open DDMS perspective.
In Devices view you will find all running processes.
Choose the process and click on Stop.

enter image description here

The third way
It will kill only background process of an application.

adb shell am kill [options] <PACKAGE> => Kill all processes associated with (the app's package name). This command kills only processes that are safe to kill and that will not impact the user experience.
Options are:

--user | all | current: Specify user whose processes to kill; all users if not specified.

The fourth way
Needs root

adb shell pm disable <PACKAGE> => Disable the given package or component (written as "package/class").

The fifth way
Note that run-as is only supported for apps that are signed with debug keys.

run-as <package-name> kill <pid>

The sixth way
Introduced in Honeycomb

adb shell am force-stop <PACKAGE> => Force stop everything associated with (the app's package name).

P.S.: I know that the sixth method didn't work for you, but I think that it's important to add this method to the list, so everyone will know it.

Convert char* to string C++

std::string str;
char* const s = "test";


string& assign (const char* s); => signature FYR

Reference/s here.

adding 30 minutes to datetime php/mysql

Try this one


How to ignore whitespace in a regular expression subject string?

You can stick optional whitespace characters \s* in between every other character in your regex. Although granted, it will get a bit lengthy.

/cats/ -> /c\s*a\s*t\s*s/

Powershell folder size of folders without listing Subdirectories

Interesting how powerful yet how helpless PS can be in the same time, coming from a Nix learning PS. after install crgwin/gitbash, you can do any combination in one commands:

size of current folder: du -sk .

size of all files and folders under current directory du -sk *

size of all subfolders (including current folders) find ./ -type d -exec du -sk {} \;

Unix's 'ls' sort by name

Files being different only by a numerical string can be sorted on this number at the condition that it is preceded by a separator.

In this case, the following syntax can be used:

ls -x1 file | sort -t'<char>' -n -k2


ls -1 TRA*log | sort -t'_' -n -k2


Unresolved external symbol in object files

I believe most of the points regarding the causes and remedies have been covered by all contributors in this thread. I just want to point out for my 'unresolved external' problem, it was caused by a datatype defined as macro that gets substituted differently than expected, which results in that incorrect type being supplied to the function in question, and since the function with type is never defined, it couldn't have been resolved. In particular, under C/C++ -> Language, there is an attribute called 'Treat WChar_t As Built in Type, which should have been defined as 'No (/Zc:wchar_t-)' but did not in my case.

How to take a screenshot programmatically on iOS

I couldn't find an answer with Swift 3 implementation. So here it goes.

static func screenshotOf(window: UIWindow) -> UIImage? {

    UIGraphicsBeginImageContextWithOptions(window.bounds.size, true, UIScreen.main.scale)

    guard let currentContext = UIGraphicsGetCurrentContext() else {
        return nil

    window.layer.render(in: currentContext)
    guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
        return nil

    return image

Check if checkbox is NOT checked on click - jQuery

Try this:



How to print something when running Puppet client?

Easier way, use notice. e.g notice("foo.pp works") or notice($foo)

Ruby on Rails form_for select field with class

You can see in here:

Or here:

Select tag has maximun 4 agrument, and last agrument is html option, it mean you can put class, require, selection option in here.

= :sms_category_id, @sms_category_collect, {}, {class: 'form-control', required: true, selected: @set}

Is there a GUI design app for the Tkinter / grid geometry?

The best tool for doing layouts using grid, IMHO, is graph paper and a pencil. I know you're asking for some type of program, but it really does work. I've been doing Tk programming for a couple of decades so layout comes quite easily for me, yet I still break out graph paper when I have a complex GUI.

Another thing to think about is this: The real power of Tkinter geometry managers comes from using them together*. If you set out to use only grid, or only pack, you're doing it wrong. Instead, design your GUI on paper first, then look for patterns that are best solved by one or the other. Pack is the right choice for certain types of layouts, and grid is the right choice for others. For a very small set of problems, place is the right choice. Don't limit your thinking to using only one of the geometry managers.

* The only caveat to using both geometry managers is that you should only use one per container (a container can be any widget, but typically it will be a frame).

How to Call a Function inside a Render in React/Jsx

To call the function you have to add ()


How to amend older Git commit?

I've used another way for a few times. In fact, it is a manual git rebase -i and it is useful when you want to rearrange several commits including squashing or splitting some of them. The main advantage is that you don't have to decide about every commit's destiny at a single moment. You'll also have all Git features available during the process unlike during a rebase. For example, you can display the log of both original and rewritten history at any time, or even do another rebase!

I'll refer to the commits in the following way, so it's readable easily:

C # good commit after a bad one
B # bad commit
A # good commit before a bad one

Your history in the beginning looks like this:

x - A - B - C
|           |
|           master

We'll recreate it to this way:

x - A - B*- C'
|           |
|           master


git checkout B       # get working-tree to the state of commit B
git reset --soft A   # tell Git that we are working before commit B
git checkout -b rewrite-history   # switch to a new branch for alternative history

Improve your old commit using git add (git add -i, git stash etc.) now. You can even split your old commit into two or more.

git commit           # recreate commit B (result = B*)
git cherry-pick C    # copy C to our new branch (result = C')

Intermediate result:

x - A - B - C 
|    \      |
|     \     master
|      \
|       B*- C'
|           |
|           rewrite-history

Let's finish:

git checkout master
git reset --hard rewrite-history  # make this branch master

Or using just one command:

git branch -f master  # make this place the new tip of the master branch

That's it, you can push your progress now.

The last task is to delete the temporary branch:

git branch -d rewrite-history

In CSS Flexbox, why are there no "justify-items" and "justify-self" properties?

I know this is not an answer, but I'd like to contribute to this matter for what it's worth. It would be great if they could release justify-self for flexbox to make it truly flexible.

It's my belief that when there are multiple items on the axis, the most logical way for justify-self to behave is to align itself to its nearest neighbours (or edge) as demonstrated below.

I truly hope, W3C takes notice of this and will at least consider it. =)

enter image description here

This way you can have an item that is truly centered regardless of the size of the left and right box. When one of the boxes reaches the point of the center box it will simply push it until there is no more space to distribute.

enter image description here

The ease of making awesome layouts are endless, take a look at this "complex" example.

enter image description here

Arithmetic overflow error converting numeric to data type numeric

If you want to reduce the size to decimal(7,2) from decimal(9,2) you will have to account for the existing data with values greater to fit into decimal(7,2). Either you will have to delete those numbers are truncate it down to fit into your new size. If there was no data for the field you are trying to update it will do it automatically without issues

How to automatically crop and center an image

There is another way you can crop image centered:

.thumbnail{position: relative; overflow: hidden; width: 320px; height: 640px;}
.thumbnail img{
    position: absolute; top: -999px; bottom: -999px; left: -999px; right: -999px;
    width: auto !important; height: 100% !important; margin: auto;
.thumbnail img.vertical{width: 100% !important; height: auto !important;}

The only thing you will need is to add class "vertical" to vertical images, you can do it with this code:

jQuery(function($) {
    $('img').one('load', function () {
        var $img = $(this);
        var tempImage1 = new Image();
        tempImage1.src = $img.attr('src');
        tempImage1.onload = function() {
            var ratio = tempImage1.width / tempImage1.height;
            if(!isNaN(ratio) && ratio < 1) $img.addClass('vertical');
    }).each(function () {
        if (this.complete) $(this).load();

Note: "!important" is used to override possible width, height attributes on img tag.

Python way to clone a git repository

This is the sample code for gitpull and gitpush using gitpython module.

import os.path
from git import *
import git, os, shutil
# create local Repo/Folder
UPLOAD_FOLDER = "LocalPath/Folder"
if not os.path.exists(UPLOAD_FOLDER):
new_path = os.path.join(UPLOADFOLDER)
DIR_NAME = new_path
REMOTE_URL = "GitURL"  # if you already connected with server you dont need to give 
any credential
# REMOTE_URL looks "[email protected]:path of Repo"
# code for clone
class git_operation_clone():
    def __init__(self):
        self.DIR_NAME = DIR_NAME
        self.REMOTE_URL = REMOTE_URL

    def git_clone(self):

        if os.path.isdir(DIR_NAME):
        repo = git.Repo.init(DIR_NAME)
        origin = repo.create_remote('origin', REMOTE_URL)
  except Exception as e:
# code for push
class git_operation_push():
  def git_push_file(self):
        repo = Repo(DIR_NAME)
        commit_message = 'work in progress'
        # repo.index.add(u=True)
        origin = repo.remote('origin')
        print("repo push succesfully")
    except Exception as e:
if __name__ == '__main__':
   a = git_operation_push()

From milliseconds to hour, minutes, seconds and milliseconds

Maybe can be shorter an more elegant. But I did it.

public String getHumanTimeFormatFromMilliseconds(String millisecondS){
    String message = "";
    long milliseconds = Long.valueOf(millisecondS);
    if (milliseconds >= 1000){
        int seconds = (int) (milliseconds / 1000) % 60;
        int minutes = (int) ((milliseconds / (1000 * 60)) % 60);
        int hours = (int) ((milliseconds / (1000 * 60 * 60)) % 24);
        int days = (int) (milliseconds / (1000 * 60 * 60 * 24));
        if((days == 0) && (hours != 0)){
            message = String.format("%d hours %d minutes %d seconds ago", hours, minutes, seconds);
        }else if((hours == 0) && (minutes != 0)){
            message = String.format("%d minutes %d seconds ago", minutes, seconds);
        }else if((days == 0) && (hours == 0) && (minutes == 0)){
            message = String.format("%d seconds ago", seconds);
            message = String.format("%d days %d hours %d minutes %d seconds ago", days, hours, minutes, seconds);
    } else{
        message = "Less than a second ago.";
    return message;

How can I get the last day of the month in C#?

DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month)

Convert String into a Class Object

You cannot store a class object into a string using toString(), toString() only returns a String representation of your object-in any way you'd like. You might want to do some reading about Serialization.

In PHP, how can I add an object element to an array?

Something like:

class TestClass {
private $var1;
private $var2;

private function TestClass($var1, $var2){
    $this->var1 = $var1;
    $this->var2 = $var2;

public static function create($var1, $var2){
    if (is_numeric($var1)){
        return new TestClass($var1, $var2);
    else return NULL;

$myArray = array();
$myArray[] = TestClass::create(15, "asdf");
$myArray[] = TestClass::create(20, "asdfa");
$myArray[] = TestClass::create("a", "abcd");


$myArray = array_filter($myArray, function($e){ return !is_null($e);});


I think that there are situations where this constructions are preferable to arrays. You can move all the checking logic to the class.

Here, before the call to array_filter $myArray has 3 elements. Two correct objects and a NULL. After the call, only the 2 correct elements persist.

NHibernate.MappingException: No persister for: XYZ

I have a similar problem but all mentioned requirements are met. In my case I try to save some entity class (Type of OBJEKTE) back to the DB. Other places do work but only in this case it fails and raises this exception.

My solution (HACK) was to re-map the objet of type OBJEKTE again and store it then. Suddenly it works. But don't ask why.

            OBJEKTE t = _mapper.Map<OBJEKTE>(inparam);
            OBJEKTE res = await _objRepo.UpdateAsync(t);

If inparam would go straight to UpdateAsync() it cannot find a matching persistor.

It could be explained by the way NH does this. It derives a proxy from your mapping class and implements the properties with dirty handling included. See this:

{Name = "OBJEKTE" FullName = "MyComp.Persistence.OBJEKTE"}

{Name = "OBJEKTEProxyForFieldInterceptor" FullName = "OBJEKTEProxyForFieldInterceptor"}

The fun thing though is that the source of inparam is in fact the NH repository itself. Anyways. I stay with this reassign hack for the next time being.

How to solve this java.lang.NoClassDefFoundError: org/apache/commons/io/output/DeferredFileOutputStream?

use maven dependency


or download commons-io.1.3.2.jar to your lib folder

Taking multiple inputs from user in python

You can read multiple inputs in Python 3.x by using below code which splits input string and converts into the integer and values are printed

user_input = input("Enter Numbers\n").split(',')
#strip is used to remove the white space. Not mandatory
all_numbers = [int(x.strip()) for x in user_input]
for i in all_numbers:

What's the main difference between Java SE and Java EE?

JavaSE and JavaEE both are computing platform which allows the developed software to run.

There are three main computing platform released by Sun Microsystems, which was eventually taken over by the Oracle Corporation. The computing platforms are all based on the Java programming language. These computing platforms are:

Java SE, i.e. Java Standard Edition. It is normally used for developing desktop applications. It forms the core/base API.

Java EE, i.e. Java Enterprise Edition. This was originally known as Java 2 Platform, Enterprise Edition or J2EE. The name was eventually changed to Java Platform, Enterprise Edition or Java EE in version 5. Java EE is mainly used for applications which run on servers, such as web sites.

Java ME, i.e. Java Micro Edition. It is mainly used for applications which run on resource constrained devices (small scale devices) like cell phones, most commonly games.

Android Studio: /dev/kvm device permission denied

Provide appropriate permissions with this command

sudo chmod 777 -R /dev/kvm

Could not load file or assembly "System.Net.Http, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"

Changing the binding information in my web.config (or app.config) - while a "hack" in my view, allows you to move forward with your project after a NuGet package update whacks your application and gives you the System.Net.Http error.

Set oldVersion="" and newVersion="" as follows

    <assemblyIdentity name="System.Net.Http" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
    <bindingRedirect oldVersion="" newVersion="" />

How to analyse the heap dump using jmap in java

VisualVm does not come with Apple JDK. You can use VisualVM Mac Application bundle(dmg) as a separate application, to compensate for that.

How can I do GUI programming in C?

Windows API and Windows SDK if you want to build everything yourself (or) Windows API and Visual C Express. Get the 2008 edition. This is a full blown IDE and a remarkable piece of software by Microsoft for Windows development.

All operating systems are written in C. So, any application, console/GUI you write in C is the standard way of writing for the operating system.

byte[] to hex string

Just to add one more answer to the pile, there is a System.Runtime.Remoting.Metadata.W3cXsd2001.SoapHexBinary class that I've used which can convert bytes to and from hex:

string hex = new SoapHexBinary(bytes).ToString();
byte[] bytes = SoapHexBinary.Parse(hex).Value;

Not sure how it compares (benchmark) to other implementations, but IMO it is pretty simple -- especially for converting from hex back into bytes.

iTerm 2: How to set keyboard shortcuts to jump to beginning/end of line?

To jump between words and start/end of lines in iTerm2 pick one of the two solutions below.

1. Simple solution (recommended)

  1. Open Preferences
  2. Click "Profile" tab
  3. Select a profile in the list on the left (eg "Default") and click "Keys" tab
  4. Click the "Presets" dropdown and select "Natural Text Editing"

enter image description here

2. Mapping keys manually (Advanced)

If you don't want to use the "Natural Text Editing" preset mentioned above, you can map the keys you need manually:

  1. Open Preferences
  2. Click “Keys” tab
  3. Click the [+] icon

You can now add the following keyboard shortcuts:

Move cursor one word left

  • Keyboard shortcut: ? + ?
  • Action: Send Hex Code
  • Code: 0x1b 0x62

enter image description here

Move cursor one word right

  • Keyboard Combination: ? + ?
  • Action: Send Hex Code
  • Code: 0x1b 0x66

Move cursor to beginning of line

  • Keyboard Combination: ? + ?
  • Action: Send Hex Code
  • Code: 0x01

Move cursor to end of line

  • Keyboard Combination: ? + ?
  • Action: Send Hex Code
  • Code: 0x05

Delete word

  • Keyboard Combination: ? + ?Delete
  • Action: Send Hex Code
  • Code: 0x1b 0x08

Delete line

  • Keyboard Combination: ? + ?Delete
  • Action: Send Hex Code
  • Code: 0x15


  • Keyboard Combination: ? + z
  • Action: Send Hex Code
  • Code: 0x1f

Don't forget to remove the previous bindings:

  • Open the “Profiles” tab
  • Click the sub-tab ”Keys”
  • Remove the mappings for key combinations ? + ? and ? + ?

Is it possible to use the SELECT INTO clause with UNION [ALL]?

The challenge I see with the solution:

SELECT top(100) *
    FROM Customers 
    SELECT top(100) *  
    FROM CustomerEurope 
    SELECT top(100) *  
    FROM CustomerAsia 
    SELECT top(100) *  
    FROM CustomerAmericas

is that this creates a windowed data set that will reside in the RAM and on larger data sets this solution will create severe performance issues as it must first create the partition and then it will use the partition to write to the temp table.

A better solution would be the following:

SELECT top(100)* into #tmpFerdeen
FROM Customers

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerEurope

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerAsia

Insert into #tmpFerdeen
SELECT top(100)* 
FROM CustomerAmericas

to select insert into the temp table and then add additional rows. However the draw back here is if there are any duplicate rows in the data.

The Best Solution would be the following:

Insert into #tmpFerdeen
SELECT top(100)* 
FROM Customers
SELECT top(100)* 
FROM CustomerEurope
SELECT top(100)* 
FROM CustomerAsia
SELECT top(100)* 
FROM CustomerAmericas

This method should work for all purposes that require distinct rows. If, however, you want the duplicate rows simply swap out the UNION for UNION ALL

Best of luck!