Programs & Examples On #Dead reckoning

MVC4 Passing model from view to controller

I hope this complete example will help you.

This is the TaxiInfo class which holds information about a taxi ride:

namespace Taxi.Models
    public class TaxiInfo
        public String Driver { get; set; }
        public Double Fare { get; set; }
        public Double Distance { get; set; }
        public String StartLocation { get; set; }
        public String EndLocation { get; set; }

We also have a convenience model which holds a List of TaxiInfo(s):

namespace Taxi.Models
    public class TaxiInfoSet
        public List<TaxiInfo> TaxiInfoList { get; set; }

        public TaxiInfoSet(params TaxiInfo[] TaxiInfos)
            TaxiInfoList = new List<TaxiInfo>();

            foreach(var TaxiInfo in TaxiInfos)

Now in the home controller we have the default Index action which for this example makes two taxi drivers and adds them to the list contained in a TaxiInfo:

public ActionResult Index()
    var taxi1 = new TaxiInfo() { Fare = 20.2, Distance = 15, Driver = "Billy", StartLocation = "Perth", EndLocation = "Brisbane" };
    var taxi2 = new TaxiInfo() { Fare = 2339.2, Distance = 1500, Driver = "Smith", StartLocation = "Perth", EndLocation = "America" };

    return View(new TaxiInfoSet(taxi1,taxi2));

The code for the view is as follows:

@model Taxi.Models.TaxiInfoSet
    ViewBag.Title = "Index";


@foreach(var TaxiInfo in Model.TaxiInfoList){
        <h1>Cost: [email protected]</h1>
        <h2>Distance: @(TaxiInfo.Distance) km</h2>
            Our diver, @TaxiInfo.Driver will take you from @TaxiInfo.StartLocation to @TaxiInfo.EndLocation

The ActionLink is responsible for the re-directing to the booking action of the Home controller (and passing in the appropriate TaxiInfo object) which is defiend as follows:

    public ActionResult Booking(TaxiInfo Taxi)
        return View(Taxi);

This returns a the following view:

@model Taxi.Models.TaxiInfo

    ViewBag.Title = "Booking";

<h2>Booking For</h2>
<h1>@Model.Driver, going from @Model.StartLocation to @Model.EndLocation (a total of @Model.Distance km) for [email protected]</h1>

A visual tour:

The Index view

The Booking view

Plot multiple lines (data series) each with unique color in R

I know, its old a post to answer but like I came across searching for the same post, someone else might turn here as well

By adding : colour in ggplot function , I could achieve the lines with different colors related to the group present in the plot.

ggplot(data=Set6, aes(x=Semana, y=Net_Sales_in_pesos, group = Agencia_ID, colour = as.factor(Agencia_ID)))    



Line Graph with Multiple colors

How to use 'hover' in CSS

You need to concatenate the selector and pseudo selector. You'll also need a style element to contain your styles. Most people use an external stylesheet, for lots of benefits (caching for one).

<a class="hover">click</a>

<style type="text/css">

    a.hover:hover {
        text-decoration: underline;



Just a note: the hover class is not necessary, unless you are defining only certain links to have this behavior (which may be the case)

Create a HTML table where each TR is a FORM

If you want a "editable grid" i.e. a table like structure that allows you to make any of the rows a form, use CSS that mimics the TABLE tag's layout: display:table, display:table-row, and display:table-cell.

There is no need to wrap your whole table in a form and no need to create a separate form and table for each apparent row of your table.

Try this instead:

<div class="table">
    <form class="tr" method="post" action="blah.html">
        <span class="td"><input type="text"/></span>
        <span class="td"><input type="text"/></span>
    <div class="tr">
        <span class="td">(cell data)</span>
        <span class="td">(cell data)</span>

The problem with wrapping the whole TABLE in a FORM is that any and all form elements will be sent on submit (maybe that is desired but probably not). This method allows you to define a form for each "row" and send only that row of data on submit.

The problem with wrapping a FORM tag around a TR tag (or TR around a FORM) is that it's invalid HTML. The FORM will still allow submit as usual but at this point the DOM is broken. Note: Try getting the child elements of your FORM or TR with JavaScript, it can lead to unexpected results.

Note that IE7 doesn't support these CSS table styles and IE8 will need a doctype declaration to get it into "standards" mode: (try this one or something equivalent)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

Any other browser that supports display:table, display:table-row and display:table-cell should display your css data table the same as it would if you were using the TABLE, TR and TD tags. Most of them do.

Note that you can also mimic THEAD, TBODY, TFOOT by wrapping your row groups in another DIV with display: table-header-group, table-row-group and table-footer-group respectively.

NOTE: The only thing you cannot do with this method is colspan.

Check out this illustration:

Simple argparse example wanted: 1 argument, 3 results

The simplest answer!

P.S. the one who wrote the document of argparse is foolish

python code:

import argparse
parser = argparse.ArgumentParser(description='')
args = parser.parse_args()
o_dct_fname = args.o_dct_fname
tp =
new_res_set = args.new_res_set

running code

python --o_dct_fname o_dct --tp father_child --new_res_set 1

How can I use random numbers in groovy?

If you want to generate random numbers in range including '0' , use the following while 'max' is the maximum number in the range.

Random rand = new Random()
random_num = rand.nextInt(max+1)

How to get height of <div> in px dimension

Use height():

var result = $("#myDiv").height();

This will give you the unit-less computed height in pixels. "px" will be stripped from the result. I.e. if the height is 400px, the result will be 400, but the result will be in pixels.

If you want to do it without jQuery, you can use plain JavaScript:

var result = document.getElementById("myDiv").offsetHeight;

Sequence contains no matching element

Well, I'd expect it's this line that's throwing the exception:

var documentRow = _dsACL.Documents.First(o => o.ID == id)

First() will throw an exception if it can't find any matching elements. Given that you're testing for null immediately afterwards, it sounds like you want FirstOrDefault(), which returns the default value for the element type (which is null for reference types) if no matching items are found:

var documentRow = _dsACL.Documents.FirstOrDefault(o => o.ID == id)

Other options to consider in some situations are Single() (when you believe there's exactly one matching element) and SingleOrDefault() (when you believe there's exactly one or zero matching elements). I suspect that FirstOrDefault is the best option in this particular case, but it's worth knowing about the others anyway.

On the other hand, it looks like you might actually be better off with a join here in the first place. If you didn't care that it would do all matches (rather than just the first) you could use:

var query = from target in _lstAcl.Documents
            join source in _dsAcl.Document
            where source.ID.ToString() equals target.ID
            select new { source, target };
foreach (var pair in query)
    target.Read = source.Read;
    target.ReadRule = source.ReadRule;
    // etc

That's simpler and more efficient IMO.

Even if you do decide to keep the loop, I have a couple of suggestions:

  • Get rid of the outer if. You don't need it, as if Count is zero the for loop body will never execute
  • Use exclusive upper bounds in for loops - they're more idiomatic in C#:

    for (i = 0; i < _lstAcl.Documents.Count; i++)
  • Eliminate common subexpressions:

    var target = _lstAcl.Documents[i];
    // Now use target for the rest of the loop body
  • Where possible use foreach instead of for to start with:

    foreach (var target in _lstAcl.Documents)

Simple state machine example in C#?

I would recommend state.cs. I personally used state.js (the JavaScript version) and am very happy with it. That C# version works in a similar way.

You instantiate states:

        // create the state machine
        var player = new StateMachine<State>( "player" );

        // create some states
        var initial = player.CreatePseudoState( "initial", PseudoStateKind.Initial );
        var operational = player.CreateCompositeState( "operational" );

You instantiate some transitions:

        var t0 = player.CreateTransition( initial, operational );
        player.CreateTransition( history, stopped );
        player.CreateTransition<String>( stopped, running, ( state, command ) => command.Equals( "play" ) );
        player.CreateTransition<String>( active, stopped, ( state, command ) => command.Equals( "stop" ) );

You define actions on states and transitions:

    t0.Effect += DisengageHead;
    t0.Effect += StopMotor;

And that's (pretty much) it. Look at the website for more information.

Jenkins/Hudson - accessing the current build number?

As per Jenkins Documentation,


is used. This number is identify how many times jenkins run this build process $BUILD_NUMBER is general syntax for it.

Excel plot time series frequency with continuous xaxis

I would like to compliment Ram Narasimhans answer with some tips I found on an Excel blog

Non-uniformly distributed data can be plotted in excel in

  • X Y (Scatter Plots)
  • Linear plots with Date axis
    • These don't take time into account, only days.
    • This method is quite cumbersome as it requires translating your time units to days, months, or years.. then change the axis labels... Not Recommended

Just like Ram Narasimhan suggested, to have the points centered you will want the mid point but you don't need to move to a numeric format, you can stay in the time format.

1- Add the center point to your data series

|    Time       | Time  | Freq |
| 08:00 - 09:00 | 08:30 |  12  |
| 09:00 - 10:00 | 09:30 |  13  |
| 10:00 - 11:00 | 10:30 |  10  |
| 13:00 - 14:00 | 13:30 |   5  |
| 14:00 - 15:00 | 14:30 |  14  |

2- Create a Scatter Plot

3- Excel allows you to specify time values for the axis options. Time values are a parts per 1 of a 24-hour day. Therefore if we want to 08:00 to 15:00, then we Set the Axis options to:

  • Minimum : Fix : 0.33333
  • Maximum : Fix : 0.625
  • Major unit : Fix : 0.041667

Line Scatter Plot

Alternative Display:

Make the points turn into columns:

To be able to represent these points as bars instead of just point we need to draw disjoint lines. Here is a way to go about getting this type of chart.

1- You're going to need to add several rows where we draw the line and disjoint the data

| Time  | Freq |
| 08:30 |   0  |
| 08:30 |  12  |
|       |      |
| 09:30 |   0  |
| 09:30 |  13  |
|       |      |
| 10:30 |   0  |
| 10:30 |  10  |
|       |      |
| 13:30 |   0  |
| 13:30 |   5  |
|       |      |
| 14:30 |   0  |
| 14:30 |  14  |

2- Plot an X Y (Scatter) Chart with Lines.

3- Now you can tweak the data series to have a fatter line, no markers, etc.. to get a bar/column type chart with non-uniformly distributed data.

Bar-Line Scatter Plot

How to update Python?

The best solution is to install the different Python versions in multiple paths.

eg. C:\Python27 for 2.7, and C:\Python33 for 3.3.

Read this for more info: How to run multiple Python versions on Windows

How to print a double with two decimals in Android?

use this one:

DecimalFormat form = new DecimalFormat("0.00");
etToll.setText(form.format(tvTotalAmount) );

Note: Data must be in decimal format (tvTotalAmount)

How do I get the day month and year from a Windows cmd.exe script?

For one line!

Try using for wmic OS Get localdatetime^|find "." in for /f without tokens and/or delims, this works in any language / region and also, no user settings interfere with the layout of the output.

  • In command line:
for /f %i in ('wmic OS Get localdatetime^|find "."')do @cmd/v/c "set _date=%i &echo= year: !_date:~0,4!&&echo=month:   !_date:~4,2!&echo=  day:   !_date:~6,2!"

  • In bat/cmd file:
for /f %%i in ('wmic OS Get localdatetime^|find "."')do @cmd/v/c "set _date=%%i &echo= year: !_date:~0,4!&&echo=month:   !_date:~4,2!&echo=  day:   !_date:~6,2!"


 year: 2019
month:   06
  day:   12

  • With Hour and Minute in bat/cmd file:
for /f %%i in ('wmic OS Get localdatetime^|find "."')do @cmd/v/c "set _date=%%i &echo=  year: !_date:~0,4!&&echo= month:   !_date:~4,2!&echo=   day:   !_date:~6,2!&echo=  hour:   !_date:~8,2!&echo=minute:   !_date:~10,2!"

  • With Hour and Minute in command line:
for /f %i in ('wmic OS Get localdatetime^|find "."')do @cmd/v/c "set _date=%i &echo=  year: !_date:~0,4!&&echo= month:   !_date:~4,2!&echo=   day:   !_date:~6,2!&echo=  hour:   !_date:~8,2!&echo=minute:   !_date:~10,2!"


  year: 2020
 month:   05
   day:   16
  hour:   00
minute:   46

How to get public directory?

Use public_path()

For reference:

// Path to the project's root folder    
echo base_path();

// Path to the 'app' folder    
echo app_path();        

// Path to the 'public' folder    
echo public_path();

// Path to the 'storage' folder    
echo storage_path();

// Path to the 'storage/app' folder    
echo storage_path('app');

How to check internet access on Android? InetAddress never times out

Kotlin implementation

* Function that uses ping, takes server name or ip as argument.
* @return [Double.MAX_VALUE] if server is not reachable. Average RTT if the server is reachable.
* Success output example
* PING ( 56(84) bytes of data.
* 64 bytes from icmp_seq=1 ttl=254 time=172 ms
* 64 bytes from icmp_seq=2 ttl=254 time=166 ms
* 64 bytes from icmp_seq=3 ttl=254 time=167 ms
* 64 bytes from icmp_seq=4 ttl=254 time=172 ms
* 64 bytes from icmp_seq=5 ttl=254 time=167 ms

* --- ping statistics ---
* 5 packets transmitted, 5 received, 0% packet loss, time 4011ms
* rtt min/avg/max/mdev = 166.470/169.313/172.322/2.539 ms
*          |________________________|
* value to parse using it.split('=')[1].trim().split(' ')[0].trim().split('/')[1].toDouble()
fun pingServerAverageRtt(host: String): Double {

    var aveRtt: Double = Double.MAX_VALUE

    try {
        // execute the command on the environment interface, timeout is set as 0.2 to get response faster.
        val pingProcess: Process = Runtime.getRuntime().exec("/system/bin/ping -i 0.2 -c 5 $host")
        // gets the input stream to get the output of the executed command
        val bufferedReader = BufferedReader(InputStreamReader(pingProcess.inputStream))

        bufferedReader.forEachLine {
            if (it.isNotEmpty() && it.contains("min/avg/max/mdev")) {  // when we get to the last line of executed ping command
                aveRtt = it.split('=')[1].trim()
                        .split(' ')[0].trim()
    } catch (e: IOException) {

    return aveRtt

Usage example

val latency = pingServerAverageRtt(ipString)
if (latency != Double.MAX_VALUE) { 
    //server reachable
} else {
    //server not reachable

Is there a W3C valid way to disable autocomplete in a HTML form?

Valid autocomplete off

<script type="text/javascript">
    /* <![CDATA[ */
    document.write('<input type="text" id="cardNumber" name="cardNumber" autocom'+'plete="off"/>');
    /* ]]> */ 

Export data from R to Excel

Recently used xlsx package, works well.

write.xlsx(x, file, sheetName="Sheet1")

where x is a data.frame

Remove HTML Tags in Javascript with Regex

you can use a powerful library for management String which is undrescore.string.js

_('a <a href="#">link</a>').stripTags()

=> 'a link'

_('a <a href="#">link</a><script>alert("hello world!")</script>').stripTags()

=> 'a linkalert("hello world!")'

Don't forget to import this lib as following :

        <script src="underscore.js" type="text/javascript"></script>
        <script src="underscore.string.js" type="text/javascript"></script>
        <script type="text/javascript"> _.mixin(_.str.exports())</script>

Object Library Not Registered When Adding Windows Common Controls 6.0

You Just execute the following commands in your command prompt,

For 32 bit machine,

cd C:\Windows\System32
regsvr32 mscomctl.ocx
regtlib msdatsrc.tlb

For 64 bit machine,

cd C:\Windows\SysWOW64
regsvr32 mscomctl.ocx
regtlib msdatsrc.tlb

NULL value for int in Update statement

By using NULL without any quotes.

UPDATE `tablename` SET `fieldName` = NULL;

XML element with attribute and content using JAXB

Here is working solution:


public class XmlTest {

    private static final Logger log = LoggerFactory.getLogger(XmlTest.class);

    public void createDefaultBook() throws JAXBException {
        JAXBContext jaxbContext = JAXBContext.newInstance(Book.class);
        Marshaller marshaller = jaxbContext.createMarshaller();

        StringWriter writer = new StringWriter();
        marshaller.marshal(new Book(), writer);

        log.debug("Book xml:\n {}", writer.toString());

    @XmlRootElement(name = "book")
    public static class Book {

        @XmlElementRef(name = "price")
        private Price price = new Price();


    @XmlRootElement(name = "price")
    public static class Price {
        @XmlAttribute(name = "drawable")
        private Boolean drawable = true; //you may want to set default value here

        private int priceValue = 1234;

        public Boolean getDrawable() {
            return drawable;

        public void setDrawable(Boolean drawable) {
            this.drawable = drawable;

        public int getPriceValue() {
            return priceValue;

        public void setPriceValue(int priceValue) {
            this.priceValue = priceValue;


22:00:18.471 [main] DEBUG com.grebski.stack.XmlTest - Book xml:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
    <price drawable="true">1234</price>

Responsive bootstrap 3 timepicker?

Was someone able to have a timepicker working with Bootstrap 3.4?

How to use multiple @RequestMapping annotations in spring?

From my test (spring 3.0.5), @RequestMapping(value={"", "/"}) - only "/" works, "" does not. However I found out this works: @RequestMapping(value={"/", " * "}), the " * " matches anything, so it will be the default handler in case no others.

How can I turn a DataTable to a CSV?

The error is the list separator.

Instead of writing sb.Append(something... + ',') you should put something like sb.Append(something... + System.Globalization.CultureInfo.CurrentCulture.TextInfo.ListSeparator);

You must put the list separator character configured in your operating system (like in the example above), or the list separator in the client machine where the file is going to be watched. Another option would be to configure it in the app.config or web.config as a parammeter of your application.

Clear History and Reload Page on Login/Logout Using Ionic Framework

Reload the page isn't the best approach.

you can handle state change events for reload data without reload the view itself.

read about ionicView life-cycle here:

and handle the event beforeEnter for data reload.

$scope.$on('$ionicView.beforeEnter', function(){
  // Any thing you can think of

How to get correct timestamp in C#

internal static string UnixToDate(int Timestamp, string ConvertFormat)
    DateTime ConvertedUnixTime = DateTimeOffset.FromUnixTimeSeconds(Timestamp).DateTime;
    return ConvertedUnixTime.ToString(ConvertFormat);

int Timestamp = (int)DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;


UnixToDate(1607013172, "HH:mm:ss"); // Output 16:32:52
Timestamp; // Output 1607013172

How to add jQuery in JS file

var jQueryScript = document.createElement('script');  

NoClassDefFoundError while trying to run my jar with java.exe -jar...what's wrong?

The -jar option is mutually exclusive of -classpath. See an old description here


Execute a program encapsulated in a JAR file. The first argument is the name of a JAR file instead of a startup class name. In order for this option to work, the manifest of the JAR file must contain a line of the form Main-Class: classname. Here, classname identifies the class having the public static void main(String[] args) method that serves as your application's starting point.

See the Jar tool reference page and the Jar trail of the Java Tutorial for information about working with Jar files and Jar-file manifests.

When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.

A quick and dirty hack is to append your classpath to the bootstrap classpath:


Specify a colon-separated path of directires, JAR archives, and ZIP archives to append to the default bootstrap class path.

However, as @Dan rightly says, the correct solution is to ensure your JARs Manifest contains the classpath for all JARs it will need.

ORA-00904: invalid identifier

Also make sure the user issuing the query has been granted the necessary permissions.

For queries on tables you need to grant SELECT permission.
For queries on other object types (e.g. stored procedures) you need to grant EXECUTE permission.

Calling stored procedure with return value

I had a similar problem with the SP call returning an error that an expected parameter was not included. My code was as follows.
Stored Procedure:

@Result int OUTPUT

And C#:

            SqlParameter result = cmd.Parameters.Add(new SqlParameter("@Result", DbType.Int32));
            result.Direction = ParameterDirection.ReturnValue;

In troubleshooting, I realized that the stored procedure was ACTUALLY looking for a direction of "InputOutput" so the following change fixed the problem.


Result.Direction = ParameterDirection.InputOutput;

ASP.NET document.getElementById('<%=Control.ClientID%>'); returns null

Is Button1 visible? I mean, from the server side. Make sure Button1.Visible is true.

Controls that aren't Visible won't be rendered in HTML, so although they are assigned a ClientID, they don't actually exist on the client side.

Instance member cannot be used on type

Another example is, you have class like :

@obc class Album: NSObject {
    let name:String
    let singer:Singer
    let artwork:URL
    let playingSong:Song

    // ...

    class func getCurrentlyPlayingSongLyric(duration: Int = 0) -> String {
        // ...
       return playingSong.lyric

you will also get the same type of error like :

instance member x cannot be used on type x. 

It's because you assign your method with "class" keyword (which makes your method a type method) and using like :

Album.getCurrentlyPlayingSongLyric(duration: 5)

but who set the playingSong variable before? Ok. You shouldn't use class keyword for that case :

 // ...

 func getCurrentlyPlayingSongLyric(duration: Int = 0) -> String {
        // ...
       return playingSong.lyric

 // ...

Now you're free to go.

Where is a log file with logs from a container?

Here is the location for

Windows 10 + WSL 2 (Ubuntu 20.04), Docker version 20.10.2, build 2291f61

Lets say

DOCKER_ARTIFACTS == \\wsl$\docker-desktop-data\version-pack-data\community\docker

Location of container logs can be found in


Here is an example

enter image description here

vue.js 2 how to watch store values from vuex

I tried literally everything to get this working.


I found that for some reason, changes to objects from $store don't necessarily trigger a .watch method. My workaround was to

  • Store
    • Create a complex data set which should but doesn't propagate changes to a Component
    • Create an incrementing counter in the state to act as a flag, which does propagate changes to a Component when watched
    • Create a method in $store.mutators to alter the complex dataset and increment the counter flag
  • Component
    • Watch for changes in the $store.state flag. When change is detected, update locally relevant reactive changes from the $store.state complex data set
    • Make changes to the $store.state's dataset using our $store.mutators method


This is implemented something like this:


let store = Vuex.Store({
  state: {
    counter: 0,
    data: { someKey: 0 }
  mutations: {
    updateSomeKey(state, value) {
      update the = value;


  data: {
    dataFromStoreDataSomeKey: null,
    someLocalValue: 1
  watch: {
    '$store.state.counter': {
        immediate: true,
        handler() {
           // update locally relevant data
           this.someLocalValue = this.$;
  methods: {
    updateSomeKeyInStore() { 
       this.$store.commit('updateSomeKey', someLocalValue);

Runnable demo

It's convoluted but basically here we are watching for a flag to change and then updating local data to reflect important changes in an object that's stored in the $state

Vue.config.devtools = false

const store = new Vuex.Store({
  state: {
    voteCounter: 0,
    // changes to objectData trigger a watch when keys are added,
    // but not when values are modified?
    votes: {
      'people': 0,
      'companies': 0,
      'total': 0,
  mutations: {
    vote(state, position) {

app = new Vue({
  el: '#app',
  store: store,
  data: {
    votesForPeople: null,
    votesForCompanies: null,
    pendingVote: null,
  computed: {
    totalVotes() {
      return this.votesForPeople + this.votesForCompanies
    peoplePercent() {
      if (this.totalVotes > 0) {
        return 100 * this.votesForPeople / this.totalVotes
      } else {
        return 0
    companiesPercent() {
      if (this.totalVotes > 0) {
        return 100 * this.votesForCompanies / this.totalVotes
      } else {
        return 0
  watch: {
    '$store.state.voteCounter': {
        immediate: true,
        handler() {
          // clone relevant data locally
          this.votesForPeople = this.$store.state.votes.people
          this.votesForCompanies = this.$store.state.votes.companies
  methods: {
    vote(event) {
      if (this.pendingVote) {
        this.$store.commit('vote', this.pendingVote)
<script src="[email protected]"></script>
<script src="[email protected]/dist/vuex.js"></script>
<link rel="stylesheet" href="[email protected]/dist/css/bootstrap.min.css">

<div id="app">
   <form @submit.prevent="vote($event)">
      <div class="form-check">
         <label class="form-check-label" for="voteCorps">
         Equal rights for companies
      <div class="form-check">
         <label class="form-check-label" for="votePeople">
         Equal rights for people
        class="btn btn-primary"
     class="progress mt-2"
     v-if="totalVotes > 0"
      <div class="progress-bar"
        :style="'width: ' + peoplePercent + '%'"
        class="progress-bar bg-success"
        :style="'width: ' + companiesPercent + '%'"

C++ obtaining milliseconds time on Linux -- clock() doesn't seem to work properly

clock() doesn't return milliseconds or seconds on linux. Usually clock() returns microseconds on a linux system. The proper way to interpret the value returned by clock() is to divide it by CLOCKS_PER_SEC to figure out how much time has passed.

Mapping many-to-many association table with extra column(s)

As said before, with JPA, in order to have the chance to have extra columns, you need to use two OneToMany associations, instead of a single ManyToMany relationship. You can also add a column with autogenerated values; this way, it can work as the primary key of the table, if useful.

For instance, the implementation code of the extra class should look like that:

@Table(name = "USER_SERVICES")
public class UserService{

    // example of auto-generated ID
    @Column(name = "USER_SERVICES_ID", nullable = false)
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long userServiceID;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "USER_ID")
    private User user;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "SERVICE_ID")
    private Service service;

    // example of extra column
    private boolean visibility;

    public long getUserServiceID() {
        return userServiceID;

    public User getUser() {
        return user;

    public void setUser(User user) {
        this.user = user;

    public Service getService() {
        return service;

    public void setService(Service service) {
        this.service = service;

    public boolean getVisibility() {
        return visibility;

    public void setVisibility(boolean visibility) {
        this.visibility = visibility;


Today`s date in an excel macro

Try the Date function. It will give you today's date in a MM/DD/YYYY format. If you're looking for today's date in the MM-DD-YYYY format try Date$. Now() also includes the current time (which you might not need). It all depends on what you need. :)

Change output format for MySQL command line results to CSV

How about using sed? It comes standard with most (all?) Linux OS.

sed 's/\t/<your_field_delimiter>/g'.

This example uses GNU sed (Linux). For POSIX sed (AIX/Solaris)I believe you would type a literal TAB instead of \t

Example (for CSV output):

#mysql mysql -B -e "select * from user" | while read; do sed 's/\t/,/g'; done


How to get index of an item in java.util.Set

How about add the strings to a hashtable where the value is an index:

  Hashtable<String, Integer> itemIndex = new Hashtable<>();
  itemIndex.put("First String",1);
  itemIndex.put("Second String",2);
  itemIndex.put("Third String",3);

  int indexOfThirdString = itemIndex.get("Third String");

Using .Select and .Where in a single LINQ statement

Did you add the Select() after the Where() or before?

You should add it after, because of the concurrency logic:

 1 Take the entire table  
 2 Filter it accordingly  
 3 Select only the ID's  
 4 Make them distinct.  

If you do a Select first, the Where clause can only contain the ID attribute because all other attributes have already been edited out.

Update: For clarity, this order of operators should work:

db.Items.Where(x=> x.userid == user_ID).Select(x=>x.Id).Distinct();

Probably want to add a .toList() at the end but that's optional :)

How to parse JSON without JSON.NET library?

For those who do not have 4.5, Here is my library function that reads json. It requires a project reference to System.Web.Extensions.

using System.Web.Script.Serialization;

public object DeserializeJson<T>(string Json)
    JavaScriptSerializer JavaScriptSerializer = new JavaScriptSerializer();
    return JavaScriptSerializer.Deserialize<T>(Json);

Usually, json is written out based on a contract. That contract can and usually will be codified in a class (T). Sometimes you can take a word from the json and search the object browser to find that type.

Example usage:

Given the json

{"logEntries":[],"value":"My Code","text":"My Text","enabled":true,"checkedIndices":[],"checkedItemsTextOverflows":false}

You could parse it into a RadComboBoxClientState object like this:

string ClientStateJson = Page.Request.Form("ReportGrid1_cboReportType_ClientState");
RadComboBoxClientState RadComboBoxClientState = DeserializeJson<RadComboBoxClientState>(ClientStateJson);
return RadComboBoxClientState.Value;

How to set environment variable for everyone under my linux system?

Amazingly, Unix and Linux do not actually have a place to set global environment variables. The best you can do is arrange for any specific shell to have a site-specific initialization.

If you put it in /etc/profile, that will take care of things for most posix-compatible shell users. This is probably "good enough" for non-critical purposes.

But anyone with a csh or tcsh shell won't see it, and I don't believe csh has a global initialization file.

Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a const function?

Use "mutable" when for things that are LOGICALLY stateless to the user (and thus should have "const" getters in the public class' APIs) but are NOT stateless in the underlying IMPLEMENTATION (the code in your .cpp).

The cases I use it most frequently are lazy initialization of state-less "plain old data" members. Namely, it is ideal in the narrow cases when such members are expensive to either build (processor) or carry around (memory) and many users of the object will never ask for them. In that situation you want lazy construction on the back end for performance, since 90% of the objects built will never need to build them at all, yet you still need to present the correct stateless API for public consumption.

Inserting values into tables Oracle SQL

INTO    Employee 
        (emp_id, emp_name, emp_address, emp_state, emp_position, emp_manager)
SELECT  '001', 'John Doe', '1 River Walk, Green Street', state_id, position_id, manager_id
FROM    dual
JOIN    state s
ON      s.state_name = 'New York'
JOIN    positions p
ON      p.position_name = 'Sales Executive'
JOIN    manager m
ON      m.manager_name = 'Barry Green'

Note that but a single spelling mistake (or an extra space) will result in a non-match and nothing will be inserted.

Understanding inplace=True

Yes, in Pandas we have many functions has the parameter inplace but by default it is assigned to False.

So, when you do df.dropna(axis='index', how='all', inplace=False) it thinks that you do not want to change the orignial DataFrame, therefore it instead creates a new copy for you with the required changes.

But, when you change the inplace parameter to True

Then it is equivalent to explicitly say that I do not want a new copy of the DataFrame instead do the changes on the given DataFrame

This forces the Python interpreter to not to create a new DataFrame

But you can also avoid using the inplace parameter by reassigning the result to the orignal DataFrame

df = df.dropna(axis='index', how='all')

Java, Shifting Elements in an Array

Write a Java program to create an array of 20 integers, and then implement the process of shifting the array to right for two elements.

public class NewClass3 {
     public static void main (String args[]){
     int a [] = {1,2,};
     int temp ;
     for(int i = 0; i<a.length -1; i++){
         temp = a[i];
         a[i] = a[i+1];
         a[i+1] = temp;
     for(int p : a)

Get the client IP address using PHP

It also works fine for internal IP addresses:

 function get_client_ip()
      $ipaddress = '';
      if (getenv('HTTP_CLIENT_IP'))
          $ipaddress = getenv('HTTP_CLIENT_IP');
      else if(getenv('HTTP_X_FORWARDED_FOR'))
          $ipaddress = getenv('HTTP_X_FORWARDED_FOR');
      else if(getenv('HTTP_X_FORWARDED'))
          $ipaddress = getenv('HTTP_X_FORWARDED');
      else if(getenv('HTTP_FORWARDED_FOR'))
          $ipaddress = getenv('HTTP_FORWARDED_FOR');
      else if(getenv('HTTP_FORWARDED'))
          $ipaddress = getenv('HTTP_FORWARDED');
      else if(getenv('REMOTE_ADDR'))
          $ipaddress = getenv('REMOTE_ADDR');
          $ipaddress = 'UNKNOWN';

      return $ipaddress;

jQuery AJAX submit form

You can also use FormData (But not available in IE):

var formData = new FormData(document.getElementsByName('yourForm')[0]);// yourForm: form selector        
    type: "POST",
    url: "yourURL",// where you wanna post
    data: formData,
    processData: false,
    contentType: false,
    error: function(jqXHR, textStatus, errorMessage) {
        console.log(errorMessage); // Optional
    success: function(data) {console.log(data)} 

This is how you use FormData.

How do you use youtube-dl to download live streams (that are live)?

I'll be using this Live Event from NASA TV as an example:

First, list the formats for the video:

$  ~ youtube-dl --list-formats\?v\=21X5lGlDOfg
[youtube] 21X5lGlDOfg: Downloading webpage
[youtube] 21X5lGlDOfg: Downloading m3u8 information
[youtube] 21X5lGlDOfg: Downloading MPD manifest
[info] Available formats for 21X5lGlDOfg:
format code  extension  resolution note
91           mp4        256x144    HLS  197k , avc1.42c00b, 30.0fps, mp4a.40.5@ 48k
92           mp4        426x240    HLS  338k , avc1.4d4015, 30.0fps, mp4a.40.5@ 48k
93           mp4        640x360    HLS  829k , avc1.4d401e, 30.0fps, mp4a.40.2@128k
94           mp4        854x480    HLS 1380k , avc1.4d401f, 30.0fps, mp4a.40.2@128k
300          mp4        1280x720   3806k , avc1.4d4020, 60.0fps, mp4a.40.2 (best)

Pick the format you wish to download, and fetch the HLS m3u8 URL of the video from the manifest. I'll be using 94 mp4 854x480 HLS 1380k , avc1.4d401f, 30.0fps, mp4a.40.2@128k for this example:

?  ~ youtube-dl -f 94 -g\?v\=21X5lGlDOfg,ei,ip,id,itag,source,requiressl,ratebypass,live,goi,sgoap,sgovp,playlist_duration,manifest_duration,vprv,playlist_type/sig/AOq0QJ8wRgIhAM2dGSece2shUTgS73Qa3KseLqnf85ca_9u7Laz7IDfSAiEAj8KHw_9xXVS_PV3ODLlwDD-xfN6rSOcLVNBpxKgkRLI%3D/lsparams/hls_chunk_host,initcwndbps,mh,mm,mn,ms,mv,mvi,pl/lsig/AG3C_xAwRQIhAJCO6kSwn7PivqMW7sZaiYFvrultXl6Qmu9wppjCvImzAiA7vkub9JaanJPGjmB4qhLVpHJOb9fZyhMEeh1EUCd-3Q%3D%3D/playlist/index.m3u8

Note that link could be different and it contains expiration timestamp, in this case 1592099895 (about 6 hours).

Now that you have the HLS playlist, you can open this URL in VLC and save it using "Record", or write a small ffmpeg command:

ffmpeg -i \,ei,ip,id,itag,source,requiressl,ratebypass,live,goi,sgoap,sgovp,playlist_duration,manifest_duration,vprv,playlist_type/sig/AOq0QJ8wRgIhAM2dGSece2shUTgS73Qa3KseLqnf85ca_9u7Laz7IDfSAiEAj8KHw_9xXVS_PV3ODLlwDD-xfN6rSOcLVNBpxKgkRLI%3D/lsparams/hls_chunk_host,initcwndbps,mh,mm,mn,ms,mv,mvi,pl/lsig/AG3C_xAwRQIhAJCO6kSwn7PivqMW7sZaiYFvrultXl6Qmu9wppjCvImzAiA7vkub9JaanJPGjmB4qhLVpHJOb9fZyhMEeh1EUCd-3Q%3D%3D/playlist/index.m3u8 \
-c copy output.ts

Deprecated meaning?

Deprecated means they don't recommend using it, and that it isn't undergoing further development. But it should not work differently than it did in a previous version unless documentation explicitly states that.

  1. Yes, otherwise it wouldn't be called "deprecated"

  2. Unless stated otherwise in docs, it should be the same as before

  3. No, but if there were problems in v1 they aren't about to fix them

Get button click inside UITableViewCell

Following code might Help you.

I have taken UITableView with custom prototype cell class named UITableViewCell inside UIViewController.

So i have ViewController.h, ViewController.m and TableViewCell.h,TableViewCell.m

Here is the code for that:


@interface ViewController : UIViewController<UITableViewDataSource,UITableViewDelegate>

@property (strong, nonatomic) IBOutlet UITableView *tblView;



@interface ViewController ()


@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return (YourNumberOfRows);

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *cellIdentifier = @"cell";

    __weak TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];

    if (indexPath.row==0) {
        [cell setDidTapButtonBlock:^(id sender)
             // Your code here

    return cell;

Custom cell class :


@interface TableViewCell : UITableViewCell

@property (copy, nonatomic) void (^didTapButtonBlock)(id sender);

@property (strong, nonatomic) IBOutlet UILabel *lblTitle;
@property (strong, nonatomic) IBOutlet UIButton *btnAction;

- (void)setDidTapButtonBlock:(void (^)(id sender))didTapButtonBlock;




@implementation TableViewCell

- (void)awakeFromNib {
    // Initialization code
    [self.btnAction addTarget:self action:@selector(didTapButton:) forControlEvents:UIControlEventTouchUpInside];


- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
- (void)didTapButton:(id)sender {
    if (self.didTapButtonBlock)

Note: Here I have taken all UIControls using Storyboard.

Hope that can help you...!!!

How to use custom font in a project written in Android Studio

First create assets folder then create fonts folder in it.

Then you can set font from assets or directory like bellow :

public class FontSampler extends Activity {
    public void onCreate(Bundle icicle) {

        TextView tv = (TextView) findViewById(;
        Typeface face = Typeface.createFromAsset(getAssets(), "fonts/HandmadeTypewriter.ttf");


        File font = new File(Environment.getExternalStorageDirectory(), "MgOpenCosmeticaBold.ttf");

        if (font.exists()) {
            tv = (TextView) findViewById(;
            face = Typeface.createFromFile(font);

        } else {

Add event handler for body.onload by javascript within <body> part

Simply wrap the code you want to execute into the onload event of the window object:

window.onload = function(){ 
   // your code here

Hiding button using jQuery

jQuery offers the .hide() method for this purpose. Simply select the element of your choice and call this method afterward. For example:


One can also determine how fast the transition runs by providing a duration parameter in miliseconds or string (possible values being 'fast', and 'slow'):


In case you want to do something just after the element hid, you must provide a callback as a parameter too:

$('#comanda').hide('fast', function() {
  alert('It is hidden now!');

Setting SMTP details for php mail () function

Check out your php.ini, you can set these values there.

Here's the description in the php manual:

If you want to use several different SMTP servers in your application, I recommend using a "bigger" mailing framework, p.e. Swiftmailer

How do I get a file name from a full path with PHP?

basename() has a bug when processing Asian characters like Chinese.

I use this:

function get_basename($filename)
    return preg_replace('/^.+[\\\\\\/]/', '', $filename);

Regular expression for not allowing spaces in the input field

This will help to find the spaces in the beginning, middle and ending:

var regexp = /\s/g

setup android on eclipse but don't know SDK directory

Late to the conversion...

For me, I found this at:

C:\Program Files (x86)\Android\android-sdk

This is the default location for Windows 64-bit.

Also, try to recall some of your default locations when not presented with some suggestions.

How to Set focus to first text input in a bootstrap modal after shown

Try to remove the tabIndex property of the modal, when your input/textbox is open. Set it back to what ever it was, when you close input/textbox. This would resolve the issue irrespective bootstrap version, and without compromising the user experience flow.

Why am I seeing "TypeError: string indices must be integers"?

data is a dict object. So, iterate over it like this:

Python 2

for key, value in data.iteritems():
    print key, value

Python 3

for key, value in data.items():
    print(key, value)

Why can't overriding methods throw exceptions broader than the overridden method?

To illustrate this, consider:

public interface FileOperation {
  void perform(File file) throws FileNotFoundException;

public class OpenOnly implements FileOperation {
  void perform(File file) throws FileNotFoundException {
    FileReader r = new FileReader(file);

Suppose you then write:

public class OpenClose implements FileOperation {
  void perform(File file) throws FileNotFoundException {
    FileReader r = new FileReader(file);

This will give you a compilation error, because r.close() throws an IOException, which is broader than FileNotFoundException.

To fix this, if you write:

public class OpenClose implements FileOperation {
  void perform(File file) throws IOException {
    FileReader r = new FileReader(file);

You will get a different compilation error, because you are implementing the perform(...) operation, but throwing an exception not included in the interface's definition of the method.

Why is this important? Well a consumer of the interface may have:

FileOperation op = ...;
try {
catch (FileNotFoundException x) {

If the IOException were allowed to be thrown, the client's code is nolonger correct.

Note that you can avoid this sort of issue if you use unchecked exceptions. (I am not suggesting you do or don't, that is a philosophical issue)

Using the star sign in grep

Use grep -P - which enables support for Perl style regular expressions.

grep -P "abc.*def" myfile

How to remove list elements in a for loop in Python?

import copy

a = ["a", "b", "c", "d", "e"]

b = copy.copy(a)

for item in a:
    print item
a = copy.copy(b)

Works: to avoid changing the list you are iterating on, you make a copy of a, iterate over it and remove the items from b. Then you copy b (the altered copy) back to a.

Getting Error "Form submission canceled because the form is not connected"

Depending on the answer from KyungHun Jeon, but the appendChild expect a dom node, so add a index to jquery object to return the node: document.body.appendChild(form[0])

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

chunks = [data[100*i:100*(i+1)] for i in range(len(data)/100 + 1)]

This is equivalent to the accepted answer. For example, shortening to batches of 10 for readability:

data = range(35)
print [data[x:x+10] for x in xrange(0, len(data), 10)]
print [data[10*i:10*(i+1)] for i in range(len(data)/10 + 1)]


[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12, 13, 14, 15, 16, 17, 18, 19], [20, 21, 22, 23, 24, 25, 26, 27, 28, 29], [30, 31, 32, 33, 34]]

Android, getting resource ID from string?

How to get an application resource id from the resource name is quite a common and well answered question.

How to get a native Android resource id from the resource name is less well answered. Here's my solution to get an Android drawable resource by resource name:

public static Drawable getAndroidDrawable(String pDrawableName){
    int resourceId=Resources.getSystem().getIdentifier(pDrawableName, "drawable", "android");
        return null;
    } else {
        return Resources.getSystem().getDrawable(resourceId);

The method can be modified to access other types of resources.

Check if a variable is null in plsql

if var is NULL then
  var :=5;
end if;

Why are hexadecimal numbers prefixed with 0x?

Short story: The 0 tells the parser it's dealing with a constant (and not an identifier/reserved word). Something is still needed to specify the number base: the x is an arbitrary choice.

Long story: In the 60's, the prevalent programming number systems were decimal and octal — mainframes had 12, 24 or 36 bits per byte, which is nicely divisible by 3 = log2(8).

The BCPL language used the syntax 8 1234 for octal numbers. When Ken Thompson created B from BCPL, he used the 0 prefix instead. This is great because

  1. an integer constant now always consists of a single token,
  2. the parser can still tell right away it's got a constant,
  3. the parser can immediately tell the base (0 is the same in both bases),
  4. it's mathematically sane (00005 == 05), and
  5. no precious special characters are needed (as in #123).

When C was created from B, the need for hexadecimal numbers arose (the PDP-11 had 16-bit words) and all of the points above were still valid. Since octals were still needed for other machines, 0x was arbitrarily chosen (00 was probably ruled out as awkward).

C# is a descendant of C, so it inherits the syntax.

iOS: Modal ViewController with transparent background

PresentViewController with Transparent background - in iOS 8 and iOS 9

MYViewController *myVC = [self.storyboard   instantiateViewControllerWithIdentifier:@"MYViewController"];
    myVC.providesPresentationContextTransitionStyle = YES;
    myVC.definesPresentationContext = YES;
    [myVC setModalPresentationStyle:UIModalPresentationOverCurrentContext];
    [self.navigationController presentViewController:myVC animated:YES completion:nil];

And in MYViewController set background color black and reduce opacity

How to get database structure in MySQL via query

Take a look at the INFORMATION_SCHEMA.TABLES table. It contains metadata about all your tables.



The advantage of this over other methods is that you can easily use queries like the one above as subqueries in your other queries.

How to read the value of a private field from a different class in Java?

Using the Reflection in Java you can access all the private/public fields and methods of one class to another .But as per the Oracle documentation in the section drawbacks they recommended that :

"Since reflection allows code to perform operations that would be illegal in non-reflective code, such as accessing private fields and methods, the use of reflection can result in unexpected side-effects, which may render code dysfunctional and may destroy portability. Reflective code breaks abstractions and therefore may change behavior with upgrades of the platform"

here is following code snapts to demonstrate basic concepts of Reflection

public class Reflection1{

    private int i = 10;

    public void methoda()

    public void methodb()

    public void methodc()



import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Reflection2{

    public static void main(String ar[]) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException
        Method[] mthd = Reflection1.class.getMethods(); // for axis the methods 

        Field[] fld = Reflection1.class.getDeclaredFields();  // for axis the fields  

        // Loop for get all the methods in class
        for(Method mthd1:mthd)

            System.out.println("method :"+mthd1.getName());
            System.out.println("parametes :"+mthd1.getReturnType());

        // Loop for get all the Field in class
        for(Field fld1:fld)
            System.out.println("field :"+fld1.getName());
            System.out.println("type :"+fld1.getType());
            System.out.println("value :"+fld1.getInt(new Reflaction1()));


Hope it will help.

Unable to begin a distributed transaction

If the servers are clustered and there is a clustered DTC you have to disable security on the clustered DTC not the local DTC.

intellij idea - Error: java: invalid source release 1.9

Gradle I had the same issue and changing all the settings given in the earlier solutions made no difference. Than I went to the build.gradle and found this line and deleted it.

sourceCompatibility = '11'

and it worked! :)

Angular EXCEPTION: No provider for Http

All you need to do is to include the following libraries in tour app.module.ts and also include it in your imports:

import { HttpModule } from '@angular/http';

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

Can I change the checkbox size using CSS?

My reputation is slightly too low to post comments, but I made a modification to Jack Miller's code above in order to get it to not change size when you check and uncheck it. This was causing text alignment problems for me.

    input[type=checkbox] {
        width: 17px;
        -webkit-appearance: none;
        -moz-appearance: none;
        height: 17px;
        border: 1px solid black;

    input[type=checkbox]:checked {
        background-color: #F58027;

    input[type=checkbox]:checked:after {
        margin-left: 4px;
        margin-top: -1px;
        width: 4px;
        height: 12px;
        border: solid white;
        border-width: 0 2px 2px 0;
        -webkit-transform: rotate(45deg);
        -moz-transform: rotate(45deg);
        -ms-transform: rotate(45deg);
        transform: rotate(45deg);
        content: "";
        display: inline-block;
    input[type=checkbox]:after {
        margin-left: 4px;
        margin-top: -1px;
        width: 4px;
        height: 12px;
        border: solid white;
        border-width: 0;
        -webkit-transform: rotate(45deg);
        -moz-transform: rotate(45deg);
        -ms-transform: rotate(45deg);
        transform: rotate(45deg);
        content: "";
        display: inline-block;
<label><input type="checkbox"> Test</label>

Single line sftp from terminal

Update Sep 2017 - tl;dr

Download a single file from a remote ftp server to your machine:

sftp {user}@{host}:{remoteFileName} {localFileName}

Upload a single file from your machine to a remote ftp server:

sftp {user}@{host}:{remote_dir} <<< $'put {local_file_path}'

Original answer:

Ok, so I feel a little dumb. But I figured it out. I almost had it at the top with:

sftp user@host remoteFile localFile

The only documentation shown in the terminal is this:

sftp [user@]host[:file ...]
sftp [user@]host[:dir[/]]

However, I came across this site which shows the following under the synopsis:

sftp [-vC1 ] [-b batchfile ] [-o ssh_option ] [-s subsystem | sftp_server ] [-B buffer_size ] [-F ssh_config ] [-P sftp_server path ] [-R num_requests ] [-S program ] host 
sftp [[user@]host[:file [file]]] 
sftp [[user@]host[:dir[/]]]

So the simple answer is you just do : after your user and host then the remote file and local filename. Incredibly simple!

Single line, sftp copy remote file:

sftp username@hostname:remoteFileName localFileName
sftp kyle@kylesserver:/tmp/myLogFile.log /tmp/fileNameToUseLocally.log

Update Feb 2016

In case anyone is looking for the command to do the reverse of this and push a file from your local computer to a remote server in one single line sftp command, user @Thariama below posted the solution to accomplish that. Hat tip to them for the extra code.

sftp {user}@{host}:{remote_dir} <<< $'put {local_file_path}'

How to create and download a csv file from php script?

If you're array structure will always be multi-dimensional in that exact fashion, then we can iterate through the elements like such:

$fh = fopen('somefile.csv', 'w') or die('Cannot open the file');

for( $i=0; $i<count($arr); $i++ ){
    $str = implode( ',', $arr[$i] );
    fwrite( $fh, $str );
    fwrite( $fh, "\n" );

That's one way to do it ... you could do it manually but this way is quicker and easier to understand and read.

Then you would manage your headers something what complex857 is doing to spit out the file. You could then delete the file using unlink() if you no longer needed it, or you could leave it on the server if you wished.

What's the proper way to install pip, virtualenv, and distribute for Python?

I came across the same problem recently. I’m becoming more partial to the “always use a virtualenv” mindset, so my problem was to install virtualenv with pip without installing distribute to my global or user site-packages directory. To do this, I manually downloaded distribute, pip and virtualenv, and for each one I ran “python install --prefix ~/.local/python-private” (with a temporary setting of PYTHONPATH=~/.local/python-private) so that setup scripts were able to find distribute). I’ve moved the virtualenv script to another directory I have on my PATH and edited it so that the distribute and virtualenv modules can be found on sys.path. Tada: I did not install anything to /usr, /usr/local or my user site-packages dir, but I can run virtualenv anywhere, and in that virtualenv I get pip.

Getting JavaScript object key list

          var data = []

How to fix ReferenceError: primordials is not defined in node


Gulp 3.* doesn't work on Node 12.* or above. You have to downgrade Node, or upgrade Gulp.

If you are short on time, downgrade Node to v11.* or below; if you need newer features, and have time to possibly fix a load of broken dependencies, upgrade Gulp to 4.* or above!

As others have already mentioned, Gulp 3.* is not supported on Node 12 or above, so you will have to downgrade your Node version to 11.* or below, OR upgrade your Gulp to 4.0.

The best option depends ultimately on how much time you have, as upgrading Gulp brings benefits of cleaner gulpfiles and in-built control over having tasks run in series or parallel, but also relies on you re-writing your gulpfile to a new syntax, and might (read: probably will - see end of this comment) cause conflicts with some dependencies.

Downgrading Node

This is the easiest and quickest option. Especially if you use n or nvm, as these allow you to very quick install and switch between Node versions.

Installing Node version on N

n 10.16.0

InstallingNode version on NVM

nvm install 10.16.0

One you have done this, you may need to rebuild your npm dependencies or alternatively remove both your node_modules folder AND your package-lock.json file and re-installing your dependencies. Though if you are merely reverting to a pre-existing Node version, you should probably be fine.

Upgrading Gulp

As mentioned above, this is a more time-intensive task, but might bring benefits in the long-run. For example, Node 12 has now introduced native support for ES Modules (behind an experimental flag) and full support in Node 13.

You may need to upgrade Node to use that, forcing you to upgrade Gulp. Or you may simply want the benefits of using Gulp 4, as it offers better and more efficient control over writing tasks.

There are a number of articles on this already, so I won't elaborate any further on the specifics, but to reiterate - this is not a quick job. Depending on the size of your project, there may be some notable re-writing required, and you may have dependencies that break. If you are in short supply of time, you should opt for simply downgrading Node, at least temporarily.

But I already have Gulp 4, and it still doesn't work!

If, like me, you are already using Gulp 4+ (I was using Gulp 4.0.2, originally on Node 10) and have recently upgraded (I upgraded to Node 13.8.0) are you are still getting the issue, it may be because a dependency is relying on an older version of Gulp, and that is getting caught in the pipeline.

In my case, gulp-combine-mq was a dependency using Gulp 3.9.*. Disabling this task in my gulpfile allowed Gulp to run again.

If this happens, you have a few options: you can,

  1. Go without the plugin if it's not absolutely necessary
  2. Find an alternative,
  3. Fix the plugin

Needless to say, if you have several plugins that rely on older version of Gulp - especially if these plugins are vital for your application - this is where there can be a huge additional chunk of time spent in upgrading Gulp (hence the warnings above).

If this happens, it is best to just downgrade Node, at least until patches can be issued.

What is :: (double colon) in Python when subscripting sequences?

When slicing in Python the third parameter is the step. As others mentioned, see Extended Slices for a nice overview.

With this knowledge, [::3] just means that you have not specified any start or end indices for your slice. Since you have specified a step, 3, this will take every third entry of something starting at the first index. For example:

>>> '123123123'[::3]

How to determine day of week by passing specific date?

Calendar cal = Calendar.getInstance(desired date);
int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);

Get the day value by providing the current time stamp.

How to add lines to end of file on Linux

The easiest way is to redirect the output of the echo by >>:

echo 'VNCSERVERS="1:root"' >> /etc/sysconfig/configfile
echo 'VNCSERVERARGS[1]="-geometry 1600x1200"' >> /etc/sysconfig/configfile

Performing user authentication in Java EE / JSF using j_security_check

The issue HttpServletRequest.login does not set authentication state in session has been fixed in 3.0.1. Update glassfish to the latest version and you're done.

Updating is quite straightforward:

glassfishv3/bin/pkg set-authority -P
glassfishv3/bin/pkg image-update

how to read System environment variable in Spring applicationContext

Declare the property place holder as follows

<bean id="propertyPlaceholderConfigurer"   
    <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
    <property name="locations">

Then lets say you want to read"") for your Tomcat bean or any bean then add following in your properties file:


How to query DATETIME field using only date in Microsoft SQL Server?

Simple answer;

select * from test where cast ([date] as date) = '03/19/2014';

Java, "Variable name" cannot be resolved to a variable

I've noticed bizarre behavior with Eclipse version 4.2.1 delivering me this error:

String cannot be resolved to a variable

With this Java code:

if (true)
    String my_variable = "somevalue";

You would think this code is very straight forward, the conditional is true, we set my_variable to somevalue. And it should print foobar. Right?

Wrong, you get the above mentioned compile time error. Eclipse is trying to prevent you from making a mistake by assuming that both statements are within the if statement.

If you put braces around the conditional block like this:

if (true){
    String my_variable = "somevalue"; }

Then it compiles and runs fine. Apparently poorly bracketed conditionals are fair game for generating compile time errors now.

How to convert HH:mm:ss.SSS to milliseconds?

Using JODA:

PeriodFormatter periodFormat = new PeriodFormatterBuilder()
  .appendHour() // 2 digits minimum
  .appendMinute() // 2 digits minimum
Period result = Period.parse(string, periodFormat);
return result.toStandardDuration().getMillis();

What is the default value for Guid?

The default value for a GUID is empty. (eg: 00000000-0000-0000-0000-000000000000)

This can be invoked using Guid.Empty or new Guid()

If you want a new GUID, you use Guid.NewGuid()

How to get the range of occupied cells in excel sheet

dim lastRow as long   'in VBA it's a long 
lastrow = wks.range("A65000").end(xlup).row

Keytool is not recognized as an internal or external command

Make sure JAVA_HOME is set and the path in environment variables. The PATH should be able to find the keytools.exe

Open “Windows search” and search for "Environment Variables"

Under “System variables” click the “New…” button and enter JAVA_HOME as “Variable name” and the path to your Java JDK directory under “Variable value” it should be similar to this C:\Program Files\Java\jre1.8.0_231

kill a process in bash

It is not clear to me what you mean by "escape an executable which is running", but ctrl-z will put a process into the background and return control to the command line. You can then use the fg command to bring the program back into the foreground.

Typescript sleep

You have to wait for TypeScript 2.0 with async/await for ES5 support as it now supported only for TS to ES6 compilation.

You would be able to create delay function with async:

function delay(ms: number) {
    return new Promise( resolve => setTimeout(resolve, ms) );

And call it

await delay(300);

Please note, that you can use await only inside async function.

If you can't (let's say you are building nodejs application), just place your code in the anonymous async function. Here is an example:

    (async () => { 
        // Do something before delay
        console.log('before delay')

        await delay(1000);

        // Do something after
        console.log('after delay')

Example TS Application:

In OLD JS you have to use

setTimeout(YourFunctionName, Milliseconds);


setTimeout( () => { /*Your Code*/ }, Milliseconds );

However with every major browser supporting async/await it less useful.

Update: TypeScript 2.1 is here with async/await.

Just do not forget that you need Promise implementation when you compile to ES5, where Promise is not natively available.


You have to export the function if you want to use it outside of the original file.

Class Not Found Exception when running JUnit test

I fixed my issue by running maven update. Right click project your project > Maven > Update Project

What is the default maximum heap size for Sun's JVM from Java SE 6?

As of JDK6U18 following are configurations for the Heap Size.

In the Client JVM, the default Java heap configuration has been modified to improve the performance of today's rich client applications. Initial and maximum heap sizes are larger and settings related to generational garbage collection are better tuned.

The default maximum heap size is half of the physical memory up to a physical memory size of 192 megabytes and otherwise one fourth of the physical memory up to a physical memory size of 1 gigabyte. For example, if your machine has 128 megabytes of physical memory, then the maximum heap size is 64 megabytes, and greater than or equal to 1 gigabyte of physical memory results in a maximum heap size of 256 megabytes. The maximum heap size is not actually used by the JVM unless your program creates enough objects to require it. A much smaller amount, termed the initial heap size, is allocated during JVM initialization. This amount is at least 8 megabytes and otherwise 1/64 of physical memory up to a physical memory size of 1 gigabyte.

Source :

Xcode warning: "Multiple build commands for output file"

As previously mentioned, this issue can be seen if you have multiple files with the same name, but in different groups (yellow folders) in the project navigator. In my case, this was intentional as I had multiple subdirectories each with a "preview.jpg" that I wanted copying to the app bundle:

group references

In this situation, you need to ensure that Xcode recognises the directory reference (blue folder icon), not just the groups.

Remove the offending files and choose "Remove Reference" (so we don't delete them entirely):

remove group references

Re-add them to the project by dragging them back into the project navigator. In the dialog that appears, choose "Create folder references for any added folders":

add as folder references

Notice that the files now have a blue folder icon in the project navigator:

folder references

If you now look under the "Copy Bundle Resources" section of the target's build phases, you will notice that there is a single entry for the entire folder, rather than entries for each item contained within the directory. The compiler will not complain about multiple build commands for those files.

npm check and update package if needed

When installing npm packages (both globally or locally) you can define a specific version by using the @version syntax to define a version to be installed.

In other words, doing: npm install -g [email protected] will ensure that only 0.9.2 is installed and won't reinstall if it already exists.

As a word of a advice, I would suggest avoiding global npm installs wherever you can. Many people don't realize that if a dependency defines a bin file, it gets installed to ./node_modules/.bin/. Often, its very easy to use that local version of an installed module that is defined in your package.json. In fact, npm scripts will add the ./node_modules/.bin onto your path.

As an example, here is a package.json that, when I run npm install && npm test will install the version of karma defined in my package.json, and use that version of karma (installed at node_modules/.bin/karma) when running the test script:

 "name": "myApp",
 "main": "app.js",
 "scripts": {
   "test": "karma test/*",
 "dependencies": {...},
 "devDependencies": {
   "karma": "0.9.2"

This gives you the benefit of your package.json defining the version of karma to use and not having to keep that config globally on your CI box.

Prolog "or" operator, query

you can 'invoke' alternative bindings on Y this way:

...registered(X, Y), (Y=ct101; Y=ct102; Y=ct103).

Note the parenthesis are required to keep the correct execution control flow. The ;/2 it's the general or operator. For your restricted use you could as well choice the more idiomatic

...registered(X, Y), member(Y, [ct101,ct102,ct103]).

that on backtracking binds Y to each member of the list.

edit I understood with a delay your last requirement. If you want that Y match all 3 values the or is inappropriate, use instead

...registered(X, ct101), registered(X, ct102), registered(X, ct103).

or the more compact

...findall(Y, registered(X, Y), L), sort(L, [ct101,ct102,ct103]).

findall/3 build the list in the very same order that registered/2 succeeds. Then I use sort to ensure the matching.

...setof(Y, registered(X, Y), [ct101,ct102,ct103]).

setof/3 also sorts the result list

How do I change the default location for Git Bash on Windows?

Once you have updated the Start in: field make sure to remove the --cd-to-home at the end of the Target: field

How to remove an id attribute from a div using jQuery?

I'm not sure what jQuery api you're looking at, but you should only have to specify id.


How can I remove the outline around hyperlinks images?

Any image that has a link will have a border around the image to help indicate it is a link with older browsers. Adding border="0" to your IMG HTML tag will prevent that picture from having a border around the image.

However, adding border="0" to every image would not only be time consuming it will also increase the file size and download time. If you don't want any of your images to have a border, create a CSS rule or CSS file that has the below code in it.

img { border-style: none; }

Python in Xcode 4+?

Another way, which I've been using for awhile in XCode3:

See steps 1-15 above.

  1. Choose /bin/bash as your executable
  2. For the "Debugger" field, select "None".
  3. In the "Arguments" tab, click the "Base Expansions On" field and select the target you created earlier.
  4. Click the "+" icon under "Arguments Passed On Launch". You may have to expand that section by clicking on the triangle pointing to the right.
  5. Type in "-l". This will tell bash to use your login environment (PYTHONPATH, etc..)
  6. Do step #19 again.
  7. Type in "-c '$(SOURCE_ROOT)/.py'"
  8. Click "OK".
  9. Start coding.

The nice thing about this way is it will use the same environment to develop in that you would use to run in outside of XCode (as setup from your bash .profile).

It's also generic enough to let you develop/run any type of file, not just python.

How to get the selected radio button value using js

If you can use jQuery "Chamika Sandamal" answer is the correct way to go. In the case you can't use jQuery you can do something like this:

function selectedRadio() {
    var radio = document.getElementsByName('mailCopy');


  • In general for the inputs you want to have unique IDs (not a requirement but a good practice)
  • All the radio inputs that are from the same group MUST have the same name attribute, for example
  • You have to set the value attribute for each input

Here is an example of input radios:

<input type="radio" name="mailCopy" value="1" />1<br />
<input type="radio" name="mailCopy" value="2" />2<br />

Does the target directory for a git clone have to match the repo name?

Yes, it is possible:

git clone Packages 

You can specify the local root directory when using git clone.


The name of a new directory to clone into.
The "humanish" part of the source repository is used if no directory is explicitly given (repo for /path/to/repo.git and foo for host.xz:foo/.git).
Cloning into an existing directory is only allowed if the directory is empty.

As Chris comments, you can then rename that top directory.
Git only cares about the .git within said top folder, which you can get with various commands:

git rev-parse --show-toplevel git rev-parse --git-dir 

Add string in a certain position in Python

This seems very easy:

>>> hash = "355879ACB6"
>>> hash = hash[:4] + '-' + hash[4:]
>>> print hash

However if you like something like a function do as this:

def insert_dash(string, index):
    return string[:index] + '-' + string[index:]

print insert_dash("355879ACB6", 5)

Test if element is present using Selenium WebDriver?

Giving my snippet of code. So, the below method checks if a random web element 'Create New Application' button exists on a page or not. Note that I have used the wait period as 0 seconds.

public boolean isCreateNewApplicationButtonVisible(){
    WebDriverWait zeroWait = new WebDriverWait(driver, 0);
    ExpectedCondition<WebElement> c = ExpectedConditions.presenceOfElementLocated(By.xpath("//input[@value='Create New Application']"));
    try {
        logger.debug("Create New Application button is visible");
        return true;
    } catch (TimeoutException e) {
        logger.debug("Create New Application button is not visible");
        return false;

How do I rename a MySQL schema?

If you're on the Model Overview page you get a tab with the schema. If you rightclick on that tab you get an option to "edit schema". From there you can rename the schema by adding a new name, then click outside the field. This goes for MySQL Workbench 5.2.30 CE

Edit: On the model overview it's under Physical Schemata


enter image description here

C# HttpWebRequest of type "application/x-www-form-urlencoded" - how to send '&' character in content body?

As long as the server allows the ampresand character to be POSTed (not all do as it can be unsafe), all you should have to do is URL Encode the character. In the case of an ampresand, you should replace the character with %26.

.NET provides a nice way of encoding the entire string for you though:

string strNew = "&uploadfile=true&file=" + HttpUtility.UrlEncode(iCalStr);

Query to list all users of a certain group

For Active Directory users, an alternative way to do this would be -- assuming all your groups are stored in OU=Groups,DC=CorpDir,DC=QA,DC=CorpName -- to use the query (&(objectCategory=group)(CN=GroupCN)). This will work well for all groups with less than 1500 members. If you want to list all members of a large AD group, the same query will work, but you'll have to use ranged retrieval to fetch all the members, 1500 records at a time.

The key to performing ranged retrievals is to specify the range in the attributes using this syntax: attribute;range=low-high. So to fetch all members of an AD Group with 3000 members, first run the above query asking for the member;range=0-1499 attribute to be returned, then for the member;range=1500-2999 attribute.

C# static class constructor

Static constructor called only the first instance of the class created.

like this:

static class YourClass
    static YourClass()

How to catch exception correctly from http.request()?

New service updated to use the HttpClientModule and RxJS v5.5.x:

import { Injectable }                    from '@angular/core';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import { Observable }                    from 'rxjs/Observable';
import { catchError, tap }               from 'rxjs/operators';
import { SomeClassOrInterface}           from './interfaces';
import 'rxjs/add/observable/throw';

export class MyService {
    url = 'http://my_url';
    constructor(private _http:HttpClient) {}
    private handleError(operation: String) {
        return (err: any) => {
            let errMsg = `error in ${operation}() retrieving ${this.url}`;
            console.log(`${errMsg}:`, err)
            if(err instanceof HttpErrorResponse) {
                // you could extract more info about the error if you want, e.g.:
                console.log(`status: ${err.status}, ${err.statusText}`);
                // errMsg = ...
            return Observable.throw(errMsg);
    // public API
    public getData() : Observable<SomeClassOrInterface> {
        // HttpClient.get() returns the body of the response as an untyped JSON object.
        // We specify the type as SomeClassOrInterfaceto get a typed result.
        return this._http.get<SomeClassOrInterface>(this.url)
                tap(data => console.log('server data:', data)), 

Old service, which uses the deprecated HttpModule:

import {Injectable}              from 'angular2/core';
import {Http, Response, Request} from 'angular2/http';
import {Observable}              from 'rxjs/Observable';
import 'rxjs/add/observable/throw';
//import 'rxjs/Rx';  // use this line if you want to be lazy, otherwise:
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/do';  // debug
import 'rxjs/add/operator/catch';

export class MyService {
    constructor(private _http:Http) {}
    private _serverError(err: any) {
        console.log('sever error:', err);  // debug
        if(err instanceof Response) {
          return Observable.throw(err.json().error || 'backend server error');
          // if you're using lite-server, use the following line
          // instead of the line above:
          //return Observable.throw(err.text() || 'backend server error');
        return Observable.throw(err || 'backend server error');
    private _request = new Request({
        method: "GET",
        // change url to "./data/data.junk" to generate an error
        url: "./data/data.json"
    // public API
    public getData() {
        return this._http.request(this._request)
          // modify file data.json to contain invalid JSON to have .json() raise an error
          .map(res => res.json())  // could raise an error if invalid JSON
          .do(data => console.log('server data:', data))  // debug

I use .do() (now .tap()) for debugging.

When there is a server error, the body of the Response object I get from the server I'm using (lite-server) contains just text, hence the reason I use err.text() above rather than err.json().error. You may need to adjust that line for your server.

If res.json() raises an error because it could not parse the JSON data, _serverError will not get a Response object, hence the reason for the instanceof check.

In this plunker, change url to ./data/data.junk to generate an error.

Users of either service should have code that can handle the error:

    selector: 'my-app',
    template: '<div>{{data}}</div> 
export class AppComponent {
    errorMsg: string;
    constructor(private _myService: MyService ) {}
    ngOnInit() {
                data => = data,
                err  => this.errorMsg = <any>err

Convert dictionary to bytes and back again python?

If you need to convert the dictionary to binary, you need to convert it to a string (JSON) as described in the previous answer, then you can convert it to binary.

For example:

my_dict = {'key' : [1,2,3]}

import json
def dict_to_binary(the_dict):
    str = json.dumps(the_dict)
    binary = ' '.join(format(ord(letter), 'b') for letter in str)
    return binary

def binary_to_dict(the_binary):
    jsn = ''.join(chr(int(x, 2)) for x in the_binary.split())
    d = json.loads(jsn)  
    return d

bin = dict_to_binary(my_dict)
print bin

dct = binary_to_dict(bin)
print dct

will give the output

1111011 100010 1101011 100010 111010 100000 1011011 110001 101100 100000 110010 101100 100000 110011 1011101 1111101

{u'key': [1, 2, 3]}

String.Replace(char, char) method in C#

As replacing "\n" with "" doesn't give you the result that you want, that means that what you should replace is actually not "\n", but some other character combination.

One possibility is that what you should replace is the "\r\n" character combination, which is the newline code in a Windows system. If you replace only the "\n" (line feed) character it will leave the "\r" (carriage return) character, which still may be interpreted as a line break, depending on how you display the string.

If the source of the string is system specific you should use that specific string, otherwise you should use Environment.NewLine to get the newline character combination for the current system.

string temp = mystring.Replace("\r\n", string.Empty);


string temp = mystring.Replace(Environment.NewLine, string.Empty);

Dynamically load a function from a DLL

In addition to the already posted answer, I thought I should share a handy trick I use to load all the DLL functions into the program through function pointers, without writing a separate GetProcAddress call for each and every function. I also like to call the functions directly as attempted in the OP.

Start by defining a generic function pointer type:

typedef int (__stdcall* func_ptr_t)();

What types that are used aren't really important. Now create an array of that type, which corresponds to the amount of functions you have in the DLL:

func_ptr_t func_ptr [DLL_FUNCTIONS_N];

In this array we can store the actual function pointers that point into the DLL memory space.

Next problem is that GetProcAddress expects the function names as strings. So create a similar array consisting of the function names in the DLL:


Now we can easily call GetProcAddress() in a loop and store each function inside that array:

for(int i=0; i<DLL_FUNCTIONS_N; i++)
  func_ptr[i] = GetProcAddress(hinst_mydll, DLL_FUNCTION_NAMES[i]);

  if(func_ptr[i] == NULL)
    // error handling, most likely you have to terminate the program here

If the loop was successful, the only problem we have now is calling the functions. The function pointer typedef from earlier isn't helpful, because each function will have its own signature. This can be solved by creating a struct with all the function types:

typedef struct
  int  (__stdcall* dll_add_ptr)(int, int);
  int  (__stdcall* dll_subtract_ptr)(int, int);
  void (__stdcall* dll_do_stuff_ptr)(something);
} functions_struct;

And finally, to connect these to the array from before, create a union:

typedef union
  functions_struct  by_type;
  func_ptr_t        func_ptr [DLL_FUNCTIONS_N];
} functions_union;

Now you can load all the functions from the DLL with the convenient loop, but call them through the by_type union member.

But of course, it is a bit burdensome to type out something like

functions.by_type.dll_add_ptr(1, 1); whenever you want to call a function.

As it turns out, this is the reason why I added the "ptr" postfix to the names: I wanted to keep them different from the actual function names. We can now smooth out the icky struct syntax and get the desired names, by using some macros:

#define dll_add (functions.by_type.dll_add_ptr)
#define dll_subtract (functions.by_type.dll_subtract_ptr)
#define dll_do_stuff (functions.by_type.dll_do_stuff_ptr)

And voilà, you can now use the function names, with the correct type and parameters, as if they were statically linked to your project:

int result = dll_add(1, 1);

Disclaimer: Strictly speaking, conversions between different function pointers are not defined by the C standard and not safe. So formally, what I'm doing here is undefined behavior. However, in the Windows world, function pointers are always of the same size no matter their type and the conversions between them are predictable on any version of Windows I've used.

Also, there might in theory be padding inserted in the union/struct, which would cause everything to fail. However, pointers happen to be of the same size as the alignment requirement in Windows. A static_assert to ensure that the struct/union has no padding might be in order still.

What are differences between AssemblyVersion, AssemblyFileVersion and AssemblyInformationalVersion?

AssemblyVersion pretty much stays internal to .NET, while AssemblyFileVersion is what Windows sees. If you go to the properties of an assembly sitting in a directory and switch to the version tab, the AssemblyFileVersion is what you'll see up top. If you sort files by version, this is what's used by Explorer.

The AssemblyInformationalVersion maps to the "Product Version" and is meant to be purely "human-used".

AssemblyVersion is certainly the most important, but I wouldn't skip AssemblyFileVersion, either. If you don't provide AssemblyInformationalVersion, the compiler adds it for you by stripping off the "revision" piece of your version number and leaving the

Configuring IntelliJ IDEA for unit testing with JUnit

Press Ctrl+Shift+T in the code editor. It will show you popup with suggestion to create a test.

Mac OS: ? Cmd+Shift+T

how to upload file using curl with php


if (function_exists('curl_file_create')) { // php 5.5+
  $cFile = curl_file_create($file_name_with_full_path);
} else { // 
  $cFile = '@' . realpath($file_name_with_full_path);
$post = array('extra_info' => '123456','file_contents'=> $cFile);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$target_url);
curl_setopt($ch, CURLOPT_POST,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
$result=curl_exec ($ch);
curl_close ($ch);

You can also refer:

Important hint for PHP 5.5+:

Now we should use but if you still want to use this deprecated approach then you need to set curl_setopt($ch, CURLOPT_SAFE_UPLOAD, false);

Best way to parse command line arguments in C#?

There are numerous solutions to this problem. For completeness and to provide the alternative if someone desires I'm adding this answer for two useful classes in my google code library.

The first is ArgumentList which is responsible only for parsing command line parameters. It collects name-value pairs defined by switches '/x:y' or '-x=y' and also collects a list of 'unnamed' entries. It's basic usage is discussed here, view the class here.

The second part of this is the CommandInterpreter which creates a fully-functional command-line application out of your .Net class. As an example:

using CSharpTest.Net.Commands;
static class Program
    static void Main(string[] args)
        new CommandInterpreter(new Commands()).Run(args);
    //example ‘Commands’ class:
    class Commands
        public int SomeValue { get; set; }
        public void DoSomething(string svalue, int ivalue)
        { ... }

With the above example code you can run the following:

Program.exe DoSomething "string value" 5

-- or --

Program.exe dosomething /ivalue=5 -svalue:"string value"

It's as simple as that or as complex as you need it to be. You can review the source code, view the help, or download the binary.

How to copy JavaScript object to new variable NOT by reference?

Your only option is to somehow clone the object.

See this stackoverflow question on how you can achieve this.

For simple JSON objects, the simplest way would be:

var newObject = JSON.parse(JSON.stringify(oldObject));

if you use jQuery, you can use:

// Shallow copy
var newObject = jQuery.extend({}, oldObject);

// Deep copy
var newObject = jQuery.extend(true, {}, oldObject);

UPDATE 2017: I should mention, since this is a popular answer, that there are now better ways to achieve this using newer versions of javascript:

In ES6 or TypeScript (2.1+):

var shallowCopy = { ...oldObject };

var shallowCopyWithExtraProp = { ...oldObject, extraProp: "abc" };

Note that if extraProp is also a property on oldObject, its value will not be used because the extraProp : "abc" is specified later in the expression, which essentially overrides it. Of course, oldObject will not be modified.

How to align a div to the top of its parent but keeping its inline-block behaviour?

Try the vertical-align CSS property.

#box1 {
    width: 50px;
    height: 50px;
    background: #999;
    display: inline-block;
    vertical-align: top; /* here */

Apply it to #box3 too.

Set height of <div> = to height of another <div> through .css

If you don't care for IE6 and IE7 users, simply use display: table-cell for your divs:


Note the use of wrapper with display: table.

For IE6/IE7 users - if you have them - you'll probably need to fallback to Javascript.

How to get N rows starting from row M from sorted table in T-SQL

@start = 3
@records = 2

Select ID, Value 
From MyTable) as sub
Where sub.RowNum between @start and @start+@records

This is one way. there are a lot of others if you google SQL Paging.

How can I fill a column with random numbers in SQL? I get the same value in every row

If you are on SQL Server 2008 you can also use

 CRYPT_GEN_RANDOM(2) % 10000

Which seems somewhat simpler (it is also evaluated once per row as newid is - shown below)



SET col1 =  CRYPT_GEN_RANDOM(2) % 10000


Returns (2 random probably different numbers)


Mulling the unexplained downvote the only legitimate reason I can think of is that because the random number generated is between 0-65535 which is not evenly divisible by 10,000 some numbers will be slightly over represented. A way around this would be to wrap it in a scalar UDF that throws away any number over 60,000 and calls itself recursively to get a replacement number.

CREATE FUNCTION dbo.RandomNumber()
      DECLARE @Result INT

      SET @Result = CRYPT_GEN_RANDOM(2)

               WHEN @Result < 60000
                     OR @@NESTLEVEL = 32 THEN @Result % 10000
               ELSE dbo.RandomNumber()

Find a private field with Reflection?

You can do it just like with a property:

FieldInfo fi = typeof(Foo).GetField("_bar", BindingFlags.NonPublic | BindingFlags.Instance);
if (fi.GetCustomAttributes(typeof(SomeAttribute)) != null)

form action with javascript

I always include the js files in the head of the html document and them in the action just call the javascript function. Something like this:


You try this?

Don't forget include the script reference in the html head.

I don't know cause of that works in firefox. Regards.

How to check if a variable is a dictionary in Python?

The OP did not exclude the starting variable, so for completeness here is how to handle the generic case of processing a supposed dictionary that may include items as dictionaries.

Also following the pure Python(3.8) recommended way to test for dictionary in the above comments.

from import Mapping

dict = {'abc': 'abc', 'def': {'ghi': 'ghi', 'jkl': 'jkl'}}

def parse_dict(in_dict): 
    if isinstance(in_dict, Mapping):
        for k_outer, v_outer in in_dict.items():
            if isinstance(v_outer, Mapping):
                for k_inner, v_inner in v_outer.items():
                    print(k_inner, v_inner)
                print(k_outer, v_outer)


How to enumerate a range of numbers starting at 1

Simplest way to do in Python 2.5 exactly what you ask about:

import itertools as it

... it.izip(it.count(1), xrange(2000, 2005)) ...

If you want a list, as you appear to, use zip in lieu of it.izip.

(BTW, as a general rule, the best way to make a list out of a generator or any other iterable X is not [x for x in X], but rather list(X)).

What is the difference between printf() and puts() in C?

int puts(const char *s);

puts() writes the string s and a trailing newline to stdout.

int printf(const char *format, ...);

The function printf() writes output to stdout, under the control of a format string that specifies how subsequent arguments are converted for output.

I'll use this opportunity to ask you to read the documentation.

HTML.ActionLink vs Url.Action in ASP.NET Razor

Html.ActionLink generates an <a href=".."></a> tag automatically.

Url.Action generates only an url.

For example:

@Html.ActionLink("link text", "actionName", "controllerName", new { id = "<id>" }, null)


<a href="/controllerName/actionName/<id>">link text</a>


@Url.Action("actionName", "controllerName", new { id = "<id>" }) 



Best plus point which I like is using Url.Action(...)

You are creating anchor tag by your own where you can set your own linked text easily even with some other html tag.

<a href="@Url.Action("actionName", "controllerName", new { id = "<id>" })">

   <img src="<ImageUrl>" style"width:<somewidth>;height:<someheight> />

   @Html.DisplayFor(model => model.<SomeModelField>)

How to get an object's methods?

Get the Method Names:

var getMethodNames = function (obj) {
    return (Object.getOwnPropertyNames(obj).filter(function (key) {
        return obj[key] && (typeof obj[key] === "function");

Or, Get the Methods:

var getMethods     = function (obj) {
    return (Object.getOwnPropertyNames(obj).filter(function (key) {
        return obj[key] && (typeof obj[key] === "function");
    })).map(function (key) {
        return obj[key];

Best way to encode text data for XML in Java?

If you are looking for a library to get the job done, try:

  1. Guava 26.0 documented here

    return XmlEscapers.xmlContentEscaper().escape(text);

    Note: There is also an xmlAttributeEscaper()

  2. Apache Commons Text 1.4 documented here


    Note: There is also an escapeXml10() method

How to make a .NET Windows Service start right after the installation?

To add to ScottTx's answer, here's the actual code to start the service if you're doing it the Microsoft way (ie. using a Setup project etc...)

(excuse the code, but this is what I'm stuck with)

Private Sub ServiceInstaller1_AfterInstall(ByVal sender As System.Object, ByVal e As System.Configuration.Install.InstallEventArgs) Handles ServiceInstaller1.AfterInstall
    Dim sc As New ServiceController()
    sc.ServiceName = ServiceInstaller1.ServiceName

    If sc.Status = ServiceControllerStatus.Stopped Then
            ' Start the service, and wait until its status is "Running".

            ' TODO: log status of service here: sc.Status
        Catch ex As Exception
            ' TODO: log an error here: "Could not start service: ex.Message"
        End Try
    End If
End Sub

To create the above event handler, go to the ProjectInstaller designer where the 2 controlls are. Click on the ServiceInstaller1 control. Go to the properties window under events and there you'll find the AfterInstall event.

Note: Don't put the above code under the AfterInstall event for ServiceProcessInstaller1. It won't work, coming from experience. :)

how to get a list of dates between two dates in java

Enhancing one of the above solutions. As adding 1 day to end date sometimes adds an extra day beyond the end date.

    public static List getDaysBetweenDates(Date startdate, Date enddate)
        List dates = new ArrayList();
        Calendar startDay = new GregorianCalendar();
        Calendar endDay = new GregorianCalendar();
        endDay.add(Calendar.DAY_OF_YEAR, 1);
        endDay.set(Calendar.HOUR_OF_DAY, 0);
        endDay.set(Calendar.MINUTE, 0);
        endDay.set(Calendar.SECOND, 0);
        endDay.set(Calendar.MILLISECOND, 0);

        while (calendar.getTime().before(endDay.getTime())) {
            Date result = startDay.getTime();
            startDay.add(Calendar.DATE, 1);
        return dates;

Updating the value of data attribute using jQuery

$('.toggle img').data('block', 'something').attr('src', 'something.jpg');

Add colorbar to existing axis

This technique is usually used for multiple axis in a figure. In this context it is often required to have a colorbar that corresponds in size with the result from imshow. This can be achieved easily with the axes grid tool kit:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable

data = np.arange(100, 0, -1).reshape(10, 10)

fig, ax = plt.subplots()
divider = make_axes_locatable(ax)
cax = divider.append_axes('right', size='5%', pad=0.05)

im = ax.imshow(data, cmap='bone')

fig.colorbar(im, cax=cax, orientation='vertical')

Image with proper colorbar in size

jQuery onclick toggle class name

It can even be made dependent to another attribute changes. like this:

$('.classA').toggleClass('classB', $('input').prop('disabled'));

In this case, classB are added each time the input is disabled

Loading state button in Bootstrap 3

You need to detect the click from js side, your HTML remaining same. Note: this method is deprecated since v3.5.5 and removed in v4.

$("button").click(function() {
    var $btn = $(this);
    // simulating a timeout
    setTimeout(function () {
    }, 1000);

Also, don't forget to load jQuery and Bootstrap js (based on jQuery) file in your page.


Official Documentation

Batch script to delete files

Consider that the files you need to delete have an extension txt and is located in the location D:\My Folder, then you could use the below code inside the bat file.

cd "D:\My Folder"
DEL *.txt 

Change image source in code behind - Wpf

You are all wrong! Why? Because all you need is this code to work:

(image View) / C# Img is : your Image box

Keep this as is, without change ("ms-appx:///) this is code not your app name Images is your folder in your project you can change it. dog.png is your file in your folder, as well as i do my folder 'Images' and file 'dog.png' So the uri is :"ms-appx:///Images/dog.png" and my code :

private void Button_Click(object sender, RoutedEventArgs e)
         img.Source = new BitmapImage(new Uri("ms-appx:///Images/dog.png"));

laravel 5 : Class 'input' not found

if You use Laravel version 5.2 Review this:

use Illuminate\Http\Request;//Access able for All requests

class myController extends Controller{
   public function myfunction(Request $request){
     $name = $request->input('username');

How can I make a CSS glass/blur effect work for an overlay?

From backdrop-filter

...apply graphical effects such as blurring or color shifting to the area behind an element. Because it applies to everything behind the element, to see the effect you must make the element or its background at least partially transparent.

Simple conversion between java.util.Date and XMLGregorianCalendar

Customizing the Calendar and Date while Marshaling

Step 1 : Prepare jaxb binding xml for custom properties, In this case i prepared for date and calendar

<jaxb:bindings version="2.1" xmlns:jaxb=""
<jaxb:globalBindings generateElementProperty="false">
<jaxb:serializable uid="1" />
<jaxb:javaType name="java.util.Date" xmlType="xs:date"
    printMethod="com.stech.jaxb.util.CalendarTypeConverter.printDate" />
<jaxb:javaType name="java.util.Calendar" xmlType="xs:dateTime"
    printMethod="com.stech.jaxb.util.CalendarTypeConverter.printCalendar" />

Setp 2 : Add custom jaxb binding file to Apache or any related plugins at xsd option like mentioned below


Setp 3 : write the code for CalendarConverter class

package com.stech.jaxb.util;

import java.text.SimpleDateFormat;

 * To convert the calendar to JaxB customer format.

public final class CalendarTypeConverter {

     * Calendar to custom format print to XML.
     * @param val
     * @return
    public static String printCalendar(java.util.Calendar val) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss");
        return simpleDateFormat.format(val.getTime());

     * Date to custom format print to XML.
     * @param val
     * @return
    public static String printDate(java.util.Date val) {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        return simpleDateFormat.format(val);

Setp 4 : Output

   <creationTime>2014-09-25T07:23:05</creationTime> Calendar class formatted

   <fileDate>2014-09-25</fileDate> - Date class formatted

View's SELECT contains a subquery in the FROM clause

As the more recent MySQL documentation on view restrictions says:

Before MySQL 5.7.7, subqueries cannot be used in the FROM clause of a view.

This means, that choosing a MySQL v5.7.7 or newer or upgrading the existing MySQL instance to such a version, would remove this restriction on views completely.

However, if you have a current production MySQL version that is earlier than v5.7.7, then the removal of this restriction on views should only be one of the criteria being assessed while making a decision as to upgrade or not. Using the workaround techniques described in the other answers may be a more viable solution - at least on the shorter run.

Calling JMX MBean method from a shell script

I'm not sure about bash-like environment. You might try some simple wrapper programs in Java (with program arguments) that invoke your MBeans on the remote server. You can then call these wrappers from the shell script

If you can use something like Python or Perl, you might be interested in JSR-262 which allows you to expose JMX operations over web services. This is scheduled to be included in Java 7 but you might be able to use a release candidate of the reference implementation

What is the difference between the HashMap and Map objects in Java?

As noted by TJ Crowder and Adamski, one reference is to an interface, the other to a specific implementation of the interface. According to Joshua Block, you should always attempt to code to interfaces, to allow you to better handle changes to underlying implementation - i.e. if HashMap suddenly was not ideal for your solution and you needed to change the map implementation, you could still use the Map interface, and change the instantiation type.

Session 'app': Error Installing APK

I had this same issue and none of the other solutions worked for me.

Although no errors were shown nor expanded upon in my IDE GUI, I opened up a second Android Studio window window with a different project and noticed in the bottom that the "Event Log" showed an error in a different window, but not in the project I had opened. The issue stated was:


Which lead me here - Install shows error in console: INSTALL FAILED CONFLICTING PROVIDER :

I had this FileProvider labeled in the manifest:

        android:resource="@xml/file_paths" />

Which I had copied from another project and forgotten to rename the 'authorities' String in. After changing it to something unique, it ran without issue.

Make sure you don't have any conflicting authority Strings like in my example.

Also, if no errors are showing up, try opening a second project and see if the "Event Log" shows errors in that location instead.

JQuery, Spring MVC @RequestBody and JSON - making it work together

In Addition you also need to be sure that you have


in your SPring configuration xml.

I also would recommend you to read this blog post. It helped me alot. Spring blog - Ajax Simplifications in Spring 3.0


just checked my working code where I have @RequestBody working correctly. I also have this bean in my config:

<bean id="jacksonMessageConverter" class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"></bean>
 <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<property name="messageConverters">
    <ref bean="jacksonMessageConverter"/>

May be it would be nice to see what Log4j is saying. it usually gives more information and from my experience the @RequestBody will fail if your request's content type is not Application/JSON. You can run Fiddler 2 to test it, or even Mozilla Live HTTP headers plugin can help.

How change default SVN username and password to commit changes?

In TortiseSVN settings

right-click menu >> settings >> Saved data >> Authentication data [Clear]

The side effect is that it clears out all authentication data and you have to re-enter your own username/password.

How to click or tap on a TextView text

OK I have answered my own question (but is it the best way?)

This is how to run a method when you click or tap on some text in a TextView:

package com.textviewy;

import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class TextyView extends Activity implements OnClickListener {

TextView t ;
public void onCreate(Bundle savedInstanceState) {
    t = (TextView)findViewById(;

public void onClick(View arg0) {
    t.setText("My text on click");  

and my main.xml is:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""
<LinearLayout android:id="@+id/LinearLayout01" android:layout_width="wrap_content"             android:layout_height="wrap_content"></LinearLayout>
<ListView android:id="@+id/ListView01" android:layout_width="wrap_content"   android:layout_height="wrap_content"></ListView>
<LinearLayout android:id="@+id/LinearLayout02" android:layout_width="wrap_content"   android:layout_height="wrap_content"></LinearLayout>

<TextView android:text="This is my first text"
 android:editable = "true"

jQuery: Scroll down page a set increment (in pixels) on click?

Updated version of HCD's solution which avoids conflict:

var y = $j(window).scrollTop(); 
$j("html, body").animate({ scrollTop: y + $j(window).height() }, 600);

What is Android's file system?

Android supports all filesystems supported by the Linux kernel, except for a few ported ones like NTFS.

The SD card is formatted as ext3, for example.

select into in mysql


CREATE TABLE new_tbl SELECT * FROM orig_tbl;


In this approach only one statement is executed when the UPDATE is successful.

-- For each row in source

UPDATE target
SET <target_columns> = <source_values>
WHERE <target_expression>

   INSERT target (<target_columns>)
VALUES (<source_values>)


How do I set a cookie on HttpClient's HttpRequestMessage

After spending hours on this issue, none of the answers above helped me so I found a really useful tool.

Firstly, I used Telerik's Fiddler 4 to study my Web Requests in details

Secondly, I came across this useful plugin for Fiddler:

It will just generate the C# code for you. An example was:

        var uriBuilder = new UriBuilder("test.php", "test");
        var httpClient = new HttpClient();

        var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, uriBuilder.ToString());

        httpRequestMessage.Headers.Add("Host", "");
        httpRequestMessage.Headers.Add("Connection", "keep-alive");
     //   httpRequestMessage.Headers.Add("Content-Length", "138");
        httpRequestMessage.Headers.Add("Pragma", "no-cache");
        httpRequestMessage.Headers.Add("Cache-Control", "no-cache");
        httpRequestMessage.Headers.Add("Origin", "");
        httpRequestMessage.Headers.Add("Upgrade-Insecure-Requests", "1");
    //    httpRequestMessage.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
        httpRequestMessage.Headers.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36");
        httpRequestMessage.Headers.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8");
        httpRequestMessage.Headers.Add("Referer", "");
        httpRequestMessage.Headers.Add("Accept-Encoding", "gzip, deflate");
        httpRequestMessage.Headers.Add("Accept-Language", "en-GB,en-US;q=0.9,en;q=0.8");
        httpRequestMessage.Headers.Add("Cookie", "__utmc=266643403; __utmz=266643403.1537352460.3.3.utmccn=(referral)||utmcct=/|utmcmd=referral; __utma=266643403.817561753.1532012719.1537357162.1537361568.5; __utmb=266643403; __atuvc=0%7C34%2C0%7C35%2C0%7C36%2C0%7C37%2C48%7C38; __atuvs=5ba2469fbb02458f002");

        var httpResponseMessage = httpClient.SendAsync(httpRequestMessage).Result;

        var httpContent = httpResponseMessage.Content;
        string result = httpResponseMessage.Content.ReadAsStringAsync().Result;

Note that I had to comment out two lines as this plugin is not totally perfect yet but it did the job nevertheless.

DISCLAIMER: I am not associated or endorsed by either Telerik or the plugin's author in anyway.

ImportError: No module named pip


curl -o

Then run the following command in the folder where you downloaded:


Maximum number of rows of CSV data in excel sheet

CSV files have no limit of rows you can add to them. Excel won't hold more that the 1 million lines of data if you import a CSV file having more lines.

Excel will actually ask you whether you want to proceed when importing more than 1 million data rows. It suggests to import the remaining data by using the text import wizard again - you will need to set the appropriate line offset.

How to do a SQL NOT NULL with a DateTime?

I faced this problem where the following query doesn't work as expected:

select 1 where getdate()<>null

we expect it to show 1 because getdate() doesn't return null. I guess it has something to do with SQL failing to cast null as datetime and skipping the row! of course we know we should use IS or IS NOT keywords to compare a variable with null but when comparing two parameters it gets hard to handle the null situation. as a solution you can create your own compare function like the following:

CREATE FUNCTION [dbo].[fnCompareDates]
    @DateTime1 datetime,
    @DateTime2 datetime
    if (@DateTime1 is null and @DateTime2 is null) return 1;
    if (@DateTime1 = @DateTime2) return 1;
    return 0

and re writing the query like:

select 1 where dbo.fnCompareDates(getdate(),null)=0

org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set

I reproduced this error message in the following three cases:

  • There does not exist database user with username written in file or file or, as in your case, in HibernateConfig file
  • The deployed database has that user but user is identified by different password than that in one of above files
  • The database has that user and the passwords match but that user does not have all privileges needed to accomplish all database tasks that your spring-boot app does

The obvious solution is to create new database user with the same username and password as in the spring-boot app or change username and password in your spring-boot app files to match an existing database user and grant sufficient privileges to that database user. In case of MySQL database this can be done as shown below:

mysql -u root -p 
>CREATE USER 'theuser'@'localhost' IDENTIFIED BY 'thepassword';
>GRANT ALL ON *.* to theuser@localhost IDENTIFIED BY 'thepassword';

Obviously there are similar commands in Postgresql but I haven't tested if in case of Postgresql this error message can be reproduced in these three cases.

Object reference not set to an instance of an object.

I know this was posted about a year ago, but this is for users for future reference.

I came across similar issue. In my case (i will try to be brief, please do let me know if you would like more detail), i was trying to check if a string was empty or not (string is the subject of an email). It always returned the same error message no matter what i did. I knew i was doing it right but it still kept throwing the same error message. Then it dawned in me that, i was checking if the subject (string) of an email (instance/object), what if the email(instance) was already a null at the first place. How could i check for a subject of an email, if the email is already a null..i checked if the the email was empty, it worked fine.

while checking for the subject(string) i used IsNullorWhiteSpace(), IsNullOrEmpty() methods.

if (email == null)
     // your code here    

Eclipse comment/uncomment shortcut?

For a Mac it is the following combination: Cmd + /

Git Ignores and Maven targets

The .gitignore file in the root directory does apply to all subdirectories. Mine looks like this:


This is in a multi-module maven project. All the submodules are imported as individual eclipse projects using m2eclipse. I have no further .gitignore files. Indeed, if you look in the gitignore man page:

Patterns read from a .gitignore file in the same directory as the path, or in any parent directory

So this should work for you.

Getting scroll bar width using JavaScript

If you use jquery.ui, try this code:


Python: avoid new line with print command

If you're using Python 2.5, this won't work, but for people using 2.6 or 2.7, try

from __future__ import print_function

print("abcd", end='')

results in


For those using 3.x, this is already built-in.

How to delete selected text in the vi editor

If you want to remove all lines in a file from your current line number, use dG, it will delete all lines (shift g) mean end of file

Formatting MM/DD/YYYY dates in textbox in VBA

Private Sub txtBoxBDayHim_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
If KeyAscii >= 48 And KeyAscii <= 57 Or KeyAscii = 8 Then 'only numbers and backspace
    If KeyAscii = 8 Then 'if backspace, ignores + "/"
        If txtBoxBDayHim.TextLength = 10 Then 'limit textbox to 10 characters
        KeyAscii = 0
            If txtBoxBDayHim.TextLength = 2 Or txtBoxBDayHim.TextLength = 5 Then 'adds / automatically
            txtBoxBDayHim.Text = txtBoxBDayHim.Text + "/"
            End If
        End If
    End If
KeyAscii = 0
End If
End Sub

This works for me. :)

Your code helped me a lot. Thanks!

I'm brazilian and my english is poor, sorry for any mistake.

Picking a random element from a set

you can also transfer the set to array use array it will probably work on small scale i see the for loop in the most voted answer is O(n) anyway

Object[] arr = set.toArray();

int v = (int) arr[rnd.nextInt(arr.length)];

detect key press in python?

So I made this ..kind of game.. based on this post (using msvcr library and Python 3.7).

The following is the "main function" of the game, that is detecting the keys pressed:

# Requiered libraries - - - -
import msvcrt
# - - - - - - - - - - - - - -

def _secret_key(self):
    # Get the key pressed by the user and check if he/she wins.

    bk = chr(10) + "-"*25 + chr(10)

    while True:

        print(bk + "Press any key(s)" + bk)
        #asks the user to type any key(s)

        kp = str(msvcrt.getch()).replace("b'", "").replace("'", "")
        # Store key's value.

        if r'\xe0' in kp:
            kp += str(msvcrt.getch()).replace("b'", "").replace("'", "")
            # Refactor the variable in case of multi press.

        if kp == r'\xe0\x8a':
            # If user pressed the secret key, the game ends.
            # \x8a is CTRL+F12, that's the secret key.

            print(bk + "CONGRATULATIONS YOU PRESSED THE SECRET KEYS!\a" + bk)
            print("Press any key to exit the game")
            print("    You pressed:'", kp + "', that's not the secret key(s)\n")
            if self.select_continue() == "n":
                if self.secondary_options():

If you want the full source code of the porgram you can see it or download it from here:

The Secret Key Game (GitHub)

(note: the secret keypress is: Ctrl+F12)

I hope you can serve as an example and help for those who come to consult this information.

How can I get the source directory of a Bash script from within the script itself?

I want to make sure that the script is running in its directory. So

cd $(dirname $(which $0) )

After this, if you really want to know where the you are running then run the command below.


Best algorithm for detecting cycles in a directed graph

As you said, you have set of jobs, it need to be executed in certain order. Topological sort given you required order for scheduling of jobs(or for dependency problems if it is a direct acyclic graph). Run dfs and maintain a list, and start adding node in the beginning of the list, and if you encountered a node which is already visited. Then you found a cycle in given graph.

Get folder name of the file in Python

You can use dirname:


Return the directory name of pathname path. This is the first element of the pair returned by passing path to the function split().

And given the full path, then you can split normally to get the last portion of the path. For example, by using basename:


Return the base name of pathname path. This is the second element of the pair returned by passing path to the function split(). Note that the result of this function is different from the Unix basename program; where basename for '/foo/bar/' returns 'bar', the basename() function returns an empty string ('').

All together:

>>> import os
>>> path=os.path.dirname("C:/folder1/folder2/filename.xml")
>>> path
>>> os.path.basename(path)

Eclipse : Maven search dependencies doesn't work

The maven add dependency is actually from the maven indexes. If the indexes is up to date, the result should be from there.

If you go to the maven repository, then select global repository, you should see a central ... tab, and select that, there should be a list of folders, and you should be able to see all the indexes from there. If not, then it means you didn't get the full index, then you can right click that and enable full index.

Another thing I annoyed me most is even I did everything, it still not showing anything when I type "spring". This is actually where I did wrong. If you just type some additional text "springframework", BOOM, the result is there.

How to implement a simple scenario the OO way

The approach I would take is: when reading the chapters from the database, instead of a collection of chapters, use a collection of books. This will have your chapters organised into books and you'll be able to use information from both classes to present the information to the user (you can even present it in a hierarchical way easily when using this approach).

Is it possible to modify a registry entry via a .bat/.cmd script?

Yes, you can script using the reg command. Example:

reg add HKCU\Software\SomeProduct
reg add HKCU\Software\SomeProduct /v Version /t REG_SZ /d v2.4.6

This would create key HKEY_CURRENT_USER\Software\SomeProduct, and add a String value "v2.4.6" named "Version" to that key.

reg /? has the details.

What is a "web service" in plain English?

In simple words Web service could be any simple program ex: add two numbers which should be published over the UDDI and can be consumed by another program.WSDL will have the endpoint to locate the webservice and also the binding and port details.

How to manipulate arrays. Find the average. Beginner Java

Try this way

public void average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    average = (double)sum/data.length;
    System.out.println("Average value of array element is " + average);    

if you need to return average value you need to use double key word Instead of the void key word and need to return value return average.

public double average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    average = (double)sum/data.length;
    return average;    

SMTP Connect() failed. Message was not sent.Mailer error: SMTP Connect() failed

You've got no SMTPSecure setting to define the type of authentication being used, and you're running the Host setting with the unnecessary 'ssl://' (PS -- ssl is over port 465, if you need to run it over ssl instead, see the accepted answer here. Here's the lines to add/change:

+ $mail->SMTPSecure = 'tls';

- $mail->Host = "ssl://";
+ $mail->Host = "";

List of all index & index columns in SQL Server DB

Since your profile states that you are using .NET you could use Server Managed Objects (SMO) programmatically... otherwise any of the above answers are fantastic.

Edit Crystal report file without Crystal Report software

In case anyone else is looking for this... as of April 2013, you can still get the free Visual Studio edition of Crystal Reports from this web site: SAP Crystal Reports - Downloads (updated url).

It installs into Visual Studio 2010 or VS 2012, and you can edit and save RPT files with as much capability as the standard Crystal Reports editor.

Adding a directory to PATH in Ubuntu

you can set it in .bashrc

PATH=$PATH:/opt/ActiveTcl-8.5/bin;export PATH;

How to select the first element of a set with JSTL?

Using ${mySet.toArray[0]} does not work.

I do not think it is possible without having forEach loop at least one iteration.

Cross-reference (named anchor) in markdown

I will quickly complement for cases where the header contains emojis, in that case it is simpler to just remove the emoji in the link of the reference. For example

# ? Title 2
[Take me to title 2](#-title-2)

There are some cases where this does not work for a weird reason, for example here in setup. The solution in that case is to include the whole code for the emoji as well.

How to convert float value to integer in php?

Use round()

$float_val = 4.5;

echo round($float_val);

You can also set param for precision and rounding mode, for more info

Update (According to your updated question):

$float_val = 1.0000124668092E+14;
printf('%.0f', $float_val / 1E+14); //Output Rounds Of To 1000012466809201

Using switch statement with a range of value in each case?

@missingfaktor 's answer is indeed correct but a bit over-complicated. Code is more verbose (at least for continuous intervals) then it could be, and requires overloads/casts and/or parameterization for long, float, Integer etc

if (num < 1)
    System.Out.Println("invalid case: " + num); // you should verify that anyway
else if (num <= 5)
    System.Out.Println("1 to 5");
else if (num <= 10)
    System.Out.Println("6 to 10");
else if (num <= 42)
    System.Out.Println("11 to 42");
    System.Out.Println("43 to +infinity");

open resource with relative path in Java

Going with the two answers as mentioned above. The first one


Should be one and same thing?

Python Web Crawlers and "getting" html source code

An Example with python3 and the requests library as mentioned by @leoluk:

pip install requests


import requests


# in case you need a session
cd = { 'sessionid': '123..'}

r = requests.get(url, cookies=cd)
# or without a session: r = requests.get(url)

Now,execute it and you will get the html source of localhost!


Angular2 - Radio Button Binding

I've created a version by using just a click event on the elements loaded and passing the value of the selection into the function "getSelection" and updating the model.

In your template:

     <li *ngFor="let p of price"><input type="radio" name="price"      (click)="getValue(price.value)" value="{{p}}" #price> {{p}} 

Your class:

export class App {


  price = ["1000", "2000", "3000"];

  constructor() {   }

  model = new SomeData(this.price);

    this.model.price = price;

See example:

How to check syslog in Bash on Linux?

tail -f /var/log/syslog | grep process_name where process_name is the name of the process we are interested in

"The page has expired due to inactivity" - Laravel 5.5

set mbstring.func_overload = 2

it helped me

How can I insert a line break into a <Text> component in React Native?

You can also just add it as a constant in your render method so its easy to reuse:

  render() {
    const br = `\n`;
     return (
        <Text>Capital Street{br}Cambridge{br}CB11 5XE{br}United Kingdom</Text>

Rotation of 3D vector?

Disclaimer: I am the author of this package

While special classes for rotations can be convenient, in some cases one needs rotation matrices (e.g. for working with other libraries like the affine_transform functions in scipy). To avoid everyone implementing their own little matrix generating functions, there exists a tiny pure python package which does nothing more than providing convenient rotation matrix generating functions. The package is on github (mgen) and can be installed via pip:

pip install mgen

Example usage copied from the readme:

import numpy as np

from mgen import rotation_around_axis
from mgen import rotation_from_angles
from mgen import rotation_around_x

matrix = rotation_from_angles([np.pi/2, 0, 0], 'XYX')[0, 1, 0])
# array([0., 0., 1.])

matrix = rotation_around_axis([1, 0, 0], np.pi/2)[0, 1, 0])
# array([0., 0., 1.])

matrix = rotation_around_x(np.pi/2)[0, 1, 0])
# array([0., 0., 1.])

Note that the matrices are just regular numpy arrays, so no new data-structures are introduced when using this package.

Transfer data between databases with PostgreSQL

Just like leonbloy suggested, using two schemas in a database is the way to go. Suppose a source schema (old DB) and a target schema (new DB), you can try something like this (you should consider column names, types, etc.):

INSERT INTO target.Awards SELECT * FROM source.Nominations;