Programs & Examples On #Regsvr32

You can use the Regsvr32 tool (Regsvr32.exe) to register and unregister OLE controls such as DLL or ActiveX Controls (OCX) files in the Windows Registry.

The module ".dll" was loaded but the entry-point was not found

The error indicates that the DLL is either not a COM DLL or it's corrupt. If it's not a COM DLL and not being used as a COM DLL by an application then there is no need to register it.
From what you say in your question (the service is not registered) it seems that we are talking about a service not correctly installed. I will try to reinstall the application.

Register comdlg32.dll gets Regsvr32: DllRegisterServer entry point was not found

Registering DLL for Fundsite

Outdated or missing comdlg32.ocx runtime library can be the problem of causing this error. Make sure comdlg32.ocx file is not corrupted otherwise Download the File comdlg32.ocx (~60 Kb Zip).

Download the file and extract the comdlg32.ocx to your the Windows\System32 folder or Windows\SysWOW64. In my case i started with Windows\System32 but it didn’t work at my end, so I again saved in Windows\SysWOW64.

Type following command from Start, Run dialog:“c:\windows>System32\regsvr32 Comdlg32.ocx “ or “c:\windows>SysWOW64\regsvr32 Comdlg32.ocx ”

Now Comdlg.ocx File is register and next step is to register the DLL

  1. Copy the Fundsite.Text.Encoding. dll into .Net Framework folder for 64bit on below path C:\Windows\Microsoft.NET\Framework64\v2.0.50727

  2. Then on command prompt and go to directory C:\Windows\Microsoft.NET\Framework64\v2.0.50727 and then run the following command as shown below.

This will register the dll successfully.

C:\Windows\\framework64\v2.0.50727>regasm "Dll Name".dll

Windows 7: unable to register DLL - Error Code:0X80004005

Use following command should work on windows 7. don't forget to enclose the dll name with full path in double quotations.

C:\Windows\SysWOW64>regsvr32 "c:\" 

How do I register a DLL file on Windows 7 64-bit?

On a x64 system, system32 is for 64 bit and syswow64 is for 32 bit (not the other way around as stated in another answer). WOW (Windows on Windows) is the 32 bit subsystem that runs under the 64 bit subsystem).

It's a mess in naming terms, and serves only to confuse, but that's the way it is.

Again ...

syswow64 is 32 bit, NOT 64 bit.

system32 is 64 bit, NOT 32 bit.

There is a regsrv32 in each of these directories. One is 64 bit, and the other is 32 bit. It is the same deal with odbcad32 and et al. (If you want to see 32-bit ODBC drivers which won't show up with the default odbcad32 in system32 which is 64-bit.)

Nodejs send file in response

You need use Stream to send file (archive) in a response, what is more you have to use appropriate Content-type in your response header.

There is an example function that do it:

const fs = require('fs');

// Where fileName is name of the file and response is Node.js Reponse. 
responseFile = (fileName, response) => {
  const filePath =  "/path/to/archive.rar" // or any file format

  // Check if file specified by the filePath exists 
  fs.exists(filePath, function(exists){
      if (exists) {     
        // Content-type is very interesting part that guarantee that
        // Web browser will handle response in an appropriate manner.
        response.writeHead(200, {
          "Content-Type": "application/octet-stream",
          "Content-Disposition": "attachment; filename=" + fileName
      } else {
        response.writeHead(400, {"Content-Type": "text/plain"});
        response.end("ERROR File does not exist");

The purpose of the Content-Type field is to describe the data contained in the body fully enough that the receiving user agent can pick an appropriate agent or mechanism to present the data to the user, or otherwise deal with the data in an appropriate manner.

"application/octet-stream" is defined as "arbitrary binary data" in RFC 2046, purpose of this content-type is to be saved to disk - it is what you really need.

"filename=[name of file]" specifies name of file which will be downloaded.

For more information please see this stackoverflow topic.

Best way to store chat messages in a database?

There's nothing wrong with saving the whole history in the database, they are prepared for that kind of tasks.

Actually you can find here in Stack Overflow a link to an example schema for a chat: example

If you are still worried for the size, you could apply some optimizations to group messages, like adding a buffer to your application that you only push after some time (like 1 minute or so); that way you would avoid having only 1 line messages

Sleep function in ORACLE

It would be better to implement a synchronization mechanism. The easiest is to write a file after the first file is complete. So you have a sentinel file.

So the external programs looks for the sentinel file to exist. When it does it knows that it can safely use the data in the real file.

Another way to do this, which is similar to how some browsers do it when downloading files, is to have the file named base-name_part until the file is completely downloaded and then at the end rename the file to base-name. This way the external program can't "see" the file until it is complete. This way wouldn't require rewrite of the external program. Which might make it best for this situation.

Can't find AVD or SDK manager in Eclipse

Try to reinstall ADT plugin on Eclipse. Check out this: Installing the Eclipse Plugin

How to convert an int value to string in Go?

ok,most of them have shown you something good. Let'me give you this:

// ToString Change arg to string
func ToString(arg interface{}, timeFormat ...string) string {
    if len(timeFormat) > 1 {
        log.SetFlags(log.Llongfile | log.LstdFlags)
        log.Println(errors.New(fmt.Sprintf("timeFormat's length should be one")))
    var tmp = reflect.Indirect(reflect.ValueOf(arg)).Interface()
    switch v := tmp.(type) {
    case int:
        return strconv.Itoa(v)
    case int8:
        return strconv.FormatInt(int64(v), 10)
    case int16:
        return strconv.FormatInt(int64(v), 10)
    case int32:
        return strconv.FormatInt(int64(v), 10)
    case int64:
        return strconv.FormatInt(v, 10)
    case string:
        return v
    case float32:
        return strconv.FormatFloat(float64(v), 'f', -1, 32)
    case float64:
        return strconv.FormatFloat(v, 'f', -1, 64)
    case time.Time:
        if len(timeFormat) == 1 {
            return v.Format(timeFormat[0])
        return v.Format("2006-01-02 15:04:05")
    case jsoncrack.Time:
        if len(timeFormat) == 1 {
            return v.Time().Format(timeFormat[0])
        return v.Time().Format("2006-01-02 15:04:05")
    case fmt.Stringer:
        return v.String()
    case reflect.Value:
        return ToString(v.Interface(), timeFormat...)
        return ""

Can Keras with Tensorflow backend be forced to use CPU or GPU at will?

For people working on PyCharm, and for forcing CPU, you can add the following line in the Run/Debug configuration, under Environment variables:


Java - How to create a custom dialog box?

If you use the NetBeans IDE (latest version at this time is 6.5.1), you can use it to create a basic GUI java application using File->New Project and choose the Java category then Java Desktop Application.

Once created, you will have a simple bare bones GUI app which contains an about box that can be opened using a menu selection. You should be able to adapt this to your needs and learn how to open a dialog from a button click.

You will be able to edit the dialog visually. Delete the items that are there and add some text areas. Play around with it and come back with more questions if you get stuck :)

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

Follow the steps given below:

  1. Stop your MySQL server completely. This can be done by accessing the Services window inside Windows XP and Windows Server 2003, where you can stop the MySQL service.

  2. Open your MS-DOS command prompt using "cmd" inside the Run window. Inside it navigate to your MySQL bin folder, such as C:\MySQL\bin using the cd command.

  3. Execute the following command in the command prompt: mysqld.exe -u root --skip-grant-tables

  4. Leave the current MS-DOS command prompt as it is, and open a new MS-DOS command prompt window.

  5. Navigate to your MySQL bin folder, such as C:\MySQL\bin using the cd command.

  6. Enter mysql and press enter.

  7. You should now have the MySQL command prompt working. Type use mysql; so that we switch to the "mysql" database.

  8. Execute the following command to update the password:

    UPDATE user SET Password = PASSWORD('NEW_PASSWORD') WHERE User = 'root'; 

However, you can now run any SQL command that you wish.

After you are finished close the first command prompt and type exit; in the second command prompt windows to disconnect successfully. You can now start the MySQL service.

error: ‘NULL’ was not declared in this scope

NULL can also be found in:

#include <string.h>

String.h will pull in the NULL from somewhere else.

Changing width property of a :before css selector using JQuery

One option is to use an attribute on the image, and modify that using jQuery. Then take that value in CSS:

HTML (note I'm assuming .cloumn is a div but it could be anything):

<div class="column" bf-width=100 >
    <img src="..." />


// General use:
$('.column').attr('bf-width', 100);
// With your image, along the lines of:
$('.column').attr('bf-width', $('img').width());

And then in order to use that value in CSS:

.column:before {
    content: attr(data-content) 'px';
    /* ... */

This will grab the attribute value from .column, and apply it on the before.

Sources: CSS attr (note the examples with before), jQuery attr.

no module named urllib.parse (How should I install it?)

pip install -U websocket 

I just use this to fix my problem

jQuery function to get all unique elements from an array?

Walk the array and push items into a hash as you come across them. Cross-reference the hash for each new element.

Note that this will ONLY work properly for primitives (strings, numbers, null, undefined, NaN) and a few objects that serialize to the same thing (functions, strings, dates, possibly arrays depending on content). Hashes in this will collide as they all serialize to the same thing, e.g. "[object Object]"

Array.prototype.distinct = function(){
   var map = {}, out = [];

   for(var i=0, l=this.length; i<l; i++){
      if(map[this[i]]){ continue; }

      map[this[i]] = 1;

   return out;

There's also no reason you can't use jQuery.unique. The only thing I don't like about it is that it destroys the ordering of your array. Here's the exact code for it if you're interested:

Sizzle.uniqueSort = function(results){
    if ( sortOrder ) {
        hasDuplicate = baseHasDuplicate;

        if ( hasDuplicate ) {
            for ( var i = 1; i < results.length; i++ ) {
                if ( results[i] === results[i-1] ) {
                    results.splice(i--, 1);

    return results;

How do I use installed packages in PyCharm?

Adding a Path

Go into File ? Settings ? Project Settings ? Project Interpreter.

Then press configure interpreter, and navigate to the "Paths" tab.

pycharm path tab

Press the + button in the Paths area. You can put the path to the module you'd like it to recognize.

But I don't know the path..

Open the python interpreter where you can import the module.

>> import gnuradio
>> gnuradio.__file__

Most commonly you'll have a folder structure like this:


You want to add foobarbaz to the path here.

TypeError: coercing to Unicode: need string or buffer

For the less specific case (not just the code in the question - since this is one of the first results in Google for this generic error message. This error also occurs when running certain os command with None argument.

For example:


Will raise this exception when arg is None.

Sizing elements to percentage of screen width/height

There are several possibilities:

1- The first one is the use of the MediaQuery :

Code :

MediaQuery.of(context).size.width //to get the width of screen
MediaQuery.of(context).size.height //to get height of screen

Example of use :

        color: Colors.yellow,
        height: MediaQuery.of(context).size.height * 0.65,
        width: MediaQuery.of(context).size.width,

Output :

enter image description here

2- The use of FractionallySizedBox

Creates a widget that sizes its child to a fraction of the total available space.

Example :

           widthFactor: 0.65, // between 0 and 1 
           heightFactor: 1.0,

Output :

enter image description here

3- The use of other widgets such as Expanded , Flexible and AspectRatio and more .

Find where java class is loaded from


Setting format and value in input type="date"

It's ugly, but it works. :/

var today = new Date().toLocaleString('en-GB').split(' ')[0].split('/').reverse().join('-');

Why use static_cast<int>(x) instead of (int)x?

The question is bigger than just using wither static_cast or C style casting because there are different things that happen when using C style casts. The C++ casting operators are intended to make these operations more explicit.

On the surface static_cast and C style casts appear to the same thing, for example when casting one value to another:

int i;
double d = (double)i;                  //C-style cast
double d2 = static_cast<double>( i );  //C++ cast

Both of these cast the integer value to a double. However when working with pointers things get more complicated. some examples:

class A {};
class B : public A {};

A* a = new B;
B* b = (B*)a;                                  //(1) what is this supposed to do?

char* c = (char*)new int( 5 );                 //(2) that weird?
char* c1 = static_cast<char*>( new int( 5 ) ); //(3) compile time error

In this example (1) maybe OK because the object pointed to by A is really an instance of B. But what if you don't know at that point in code what a actually points to? (2) maybe perfectly legal(you only want to look at one byte of the integer), but it could also be a mistake in which case an error would be nice, like (3). The C++ casting operators are intended to expose these issues in the code by providing compile-time or run-time errors when possible.

So, for strict "value casting" you can use static_cast. If you want run-time polymorphic casting of pointers use dynamic_cast. If you really want to forget about types, you can use reintrepret_cast. And to just throw const out the window there is const_cast.

They just make the code more explicit so that it looks like you know what you were doing.

2 ways for "ClearContents" on VBA Excel, but 1 work fine. Why?

For numerical addressing of cells try to enable S1O1 checkbox in MS Excel settings. It is the second tab from top (i.e. Formulas), somewhere mid-page in my Hungarian version.

If enabled, it handles VBA addressing in both styles, i.e. Range("A1:B10") and Range(Cells(1, 1), Cells(10, 2)). I assume it handles Range("A1:B10") style only, if not enabled.

Good luck!

(Note, that Range("A1:B10") represents a 2x10 square, while Range(Cells(1, 1), Cells(10, 2)) represents 10x2. Using column numbers instead of letters will not affect the order of addresing.)

javascript - Create Simple Dynamic Array

I had a similar problem and a solution I found (forgot where I found it) is this:

Array.from(Array(mynumber), (val, index) => index + 1)

CASE (Contains) rather than equal statement

CASE WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

The leading ', ' and trailing ',' are added so that you can handle the match regardless of where it is in the string (first entry, last entry, or anywhere in between).

That said, why are you storing data you want to search on as a comma-separated string? This violates all kinds of forms and best practices. You should consider normalizing your schema.

In addition: don't use 'single quotes' as identifier delimiters; this syntax is deprecated. Use [square brackets] (preferred) or "double quotes" if you must. See "string literals as column aliases" here:

EDIT If you have multiple values, you can do this (you can't short-hand this with the other CASE syntax variant or by using something like IN()):

  WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  WHEN ', ' + dbo.Table.Column +',' LIKE '%, amlodipine,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

If you have more values, it might be worthwhile to use a split function, e.g.

USE tempdb;

       ( SELECT Item = x.i.value('(./text())[1]', 'nvarchar(max)')
         FROM ( SELECT [XML] = CONVERT(XML, '<i>'
         + REPLACE(@List,',', '</i><i>') + '</i>').query('.')
           ) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y

CREATE TABLE dbo.[Table](ID INT, [Column] VARCHAR(255));

(1,'lactulose, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(2,'lactulite, Lasix (furosemide), lactulose, propranolol, rabeprazole, sertraline,'),
(3,'lactulite, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(4,'lactulite, Lasix (furosemide), lactulose, amlodipine, rabeprazole, sertraline,');

  FROM dbo.[Table] AS t
  INNER JOIN dbo.SplitStrings('lactulose,amlodipine') AS s
  ON ', ' + t.[Column] + ',' LIKE '%, ' + s.Item + ',%'



Sequelize.js delete query?

In new version, you can try something like this

function (req,res) {    
            where: {
        .then(function (deletedRecord) {
            if(deletedRecord === 1){
                res.status(200).json({message:"Deleted successfully"});          
                res.status(404).json({message:"record not found"})
        .catch(function (error){

How to check whether a file is empty or not?

Both getsize() and stat() will throw an exception if the file does not exist. This function will return True/False without throwing (simpler but less robust):

import os
def is_non_zero_file(fpath):  
    return os.path.isfile(fpath) and os.path.getsize(fpath) > 0

How to get previous month and year relative to today, using strtotime and date?

Have a look at the DateTime class. It should do the calculations correctly and the date formats are compatible with strttotime. Something like:

$datestring='2011-03-30 first day of last month';
echo $dt->format('Y-m'); //2011-02

How to change the data type of a column without dropping the column with query?

ALTER TABLE YourTableNameHere ALTER COLUMN YourColumnNameHere VARCHAR(20)

How do I size a UITextView to its content?

To make a dynamically sizing UITextView inside a UITableViewCell, I found the following combination works in Xcode 6 with the iOS 8 SDK:

  • Add a UITextView to a UITableViewCell and constrain it to the sides
  • Set the UITextView's scrollEnabled property to NO. With scrolling enabled, the frame of the UITextView is independent of its content size, but with scrolling disabled, there is a relationship between the two.
  • If your table is using the original default row height of 44 then it will automatically calculate row heights, but if you changed the default row height to something else, you may need to manually switch on auto-calculation of row heights in viewDidLoad:

    tableView.estimatedRowHeight = 150;
    tableView.rowHeight = UITableViewAutomaticDimension;

For read-only dynamically sizing UITextViews, that’s it. If you’re allowing users to edit the text in your UITextView, you also need to:

  • Implement the textViewDidChange: method of the UITextViewDelegate protocol, and tell the tableView to repaint itself every time the text is edited:

    - (void)textViewDidChange:(UITextView *)textView;
        [tableView beginUpdates];
        [tableView endUpdates];
  • And don’t forget to set the UITextView delegate somewhere, either in Storyboard or in tableView:cellForRowAtIndexPath:

Run a single test method with maven

Run a single test method from a test class.

mvn test -Dtest=Test1#methodname

Other related use-cases

  • mvn test // Run all the unit test classes

  • mvn test -Dtest=Test1 // Run a single test class

  • mvn test -Dtest=Test1,Test2 // Run multiple test classes

  • mvn test -Dtest=Test1#testFoo* // Run all test methods that match pattern 'testFoo*' from a test class.

  • mvn test -Dtest=Test1#testFoo*+testBar* // Run all test methods match pattern 'testFoo*' and 'testBar*' from a test class.

Get height of div with no height set in css

jQuery .height will return you the height of the element. It doesn't need CSS definition as it determines the computed height.


You can use .height(), .innerHeight() or outerHeight() based on what you need.

enter image description here

.height() - returns the height of element excludes padding, border and margin.

.innerHeight() - returns the height of element includes padding but excludes border and margin.

.outerHeight() - returns the height of the div including border but excludes margin.

.outerHeight(true) - returns the height of the div including margin.

Check below code snippet for live demo. :)

$(function() {_x000D_
  var $heightTest = $('#heightTest');_x000D_
  $heightTest.html('Div style set as "height: 180px; padding: 10px; margin: 10px; border: 2px solid blue;"')_x000D_
    .append('<p>Height (.height() returns) : ' + $heightTest.height() + ' [Just Height]</p>')_x000D_
    .append('<p>Inner Height (.innerHeight() returns): ' + $heightTest.innerHeight() + ' [Height + Padding (without border)]</p>')_x000D_
    .append('<p>Outer Height (.outerHeight() returns): ' + $heightTest.outerHeight() + ' [Height + Padding + Border]</p>')_x000D_
    .append('<p>Outer Height (.outerHeight(true) returns): ' + $heightTest.outerHeight(true) + ' [Height + Padding + Border + Margin]</p>')_x000D_
div { font-size: 0.9em; }
<script src=""></script>_x000D_
<div id="heightTest" style="height: 150px; padding: 10px; margin: 10px; border: 2px solid blue; overflow: hidden; ">_x000D_

how to make a jquery "$.post" request synchronous

If you want an synchronous request set the async property to false for the request. Check out the jQuery AJAX Doc


Simple query without partition clause:

    RANK() over(order by sal desc) as Rank,
    DENSE_RANK() over(order by sal desc) as DenseRank,
    ROW_NUMBER() over(order by sal desc) as RowNumber
from employee 


    sal     |Rank   |DenseRank  |RowNumber
    5000    |1      |1          |1
    3000    |2      |2          |2
    3000    |2      |2          |3
    2975    |4      |3          |4
    2850    |5      |4          |5

How to use python numpy.savetxt to write strings and float number to an ASCII file?

The currently accepted answer does not actually address the question, which asks how to save lists that contain both strings and float numbers. For completeness I provide a fully working example, which is based, with some modifications, on the link given in @joris comment.

import numpy as np

names  = np.array(['NAME_1', 'NAME_2', 'NAME_3'])
floats = np.array([ 0.1234 ,  0.5678 ,  0.9123 ])

ab = np.zeros(names.size, dtype=[('var1', 'U6'), ('var2', float)])
ab['var1'] = names
ab['var2'] = floats

np.savetxt('test.txt', ab, fmt="%10s %10.3f")

Update: This example also works properly in Python 3 by using the 'U6' Unicode string dtype, when creating the ab structured array, instead of the 'S6' byte string. The latter dtype would work in Python 2.7, but would write strings like b'NAME_1' in Python 3.

How do I determine the current operating system with Node.js

I was facing the same issue running my node js code on Windows VM on mac machine. The following code did the trick.


process.platform == 'win32'


const os = require('os');

os.platform() == 'win32';

Website screenshots

you can use cutycapt .

kwhtml is deprecated and show page like old browser.

How can I get a JavaScript stack trace when I throw an exception?

In Firefox it seems that you don't need to throw the exception. It's sufficient to do

e = new Error();

How do I print the full value of a long string in gdb?

Using set elements ... isn't always the best way. It would be useful if there were a distinct set string-elements ....

So, I use these functions in my .gdbinit:

define pstr
  ptype $arg0._M_dataplus._M_p
  printf "[%d] = %s\n", $arg0._M_string_length, $arg0._M_dataplus._M_p

define pcstr
  ptype $arg0
  printf "[%d] = %s\n", strlen($arg0), $arg0


  • The first is c++ lib dependent as it accesses members of std::string, but is easily adjusted.
  • The second can only be used on a running program as it calls strlen.

What's the difference between a POST and a PUT HTTP REQUEST?

It should be pretty straightforward when to use one or the other, but complex wordings are a source of confusion for many of us.

When to use them:

  • Use PUT when you want to modify a singular resource that is already a part of resource collection. PUT replaces the resource in its entirety. Example: PUT /resources/:resourceId

    Sidenote: Use PATCH if you want to update a part of the resource.

  • Use POST when you want to add a child resource under a collection of resources.
    Example: POST => /resources

In general:

  • Generally, in practice, always use PUT for UPDATE operations.
  • Always use POST for CREATE operations.


GET /company/reports => Get all reports
GET /company/reports/{id} => Get the report information identified by "id"
POST /company/reports => Create a new report
PUT /company/reports/{id} => Update the report information identified by "id"
PATCH /company/reports/{id} => Update a part of the report information identified by "id"
DELETE /company/reports/{id} => Delete report by "id"

Find non-ASCII characters in varchar columns using SQL Server

To find which field has invalid characters:


You can test it with this query:

SELECT top 1 'char 31: '+char(31)+' (hex 0x1F)' field
from sysobjects

The result will be:

Msg 6841, Level 16, State 1, Line 3 FOR XML could not serialize the data for node 'field' because it contains a character (0x001F) which is not allowed in XML. To retrieve this data using FOR XML, convert it to binary, varbinary or image data type and use the BINARY BASE64 directive.

It is very useful when you write xml files and get error of invalid characters when validate it.

Testing HTML email rendering

If you are converting your HTML pages to Email. You should check Premailer,

It converts CSS to inline CSS and also tests the compatibility with major email clients.

How to control the width and height of the default Alert Dialog in Android?

longButton.setOnClickListener {
    "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +
      "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +
      "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +
      "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +
      "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +
      "1\n2\n3\n4\n5\n6\n7\n8\n9\n0\n" +

shortButton.setOnClickListener {
    "1234567890\n" +

private fun show(msg: String) {
  val builder = AlertDialog.Builder(this).apply {
    setPositiveButton(android.R.string.ok, null)
    setNegativeButton(android.R.string.cancel, null)

  val dialog = builder.create().apply {

  dialog.window?.decorView?.addOnLayoutChangeListener { v, _, _, _, _, _, _, _, _ ->
    val displayRectangle = Rect()
    val window = dialog.window
    val maxHeight = displayRectangle.height() * 0.6f // 60%

    if (v.height > maxHeight) {
      window?.setLayout(window.attributes.width, maxHeight.toInt())

short message

long message

Visual Studio: LINK : fatal error LNK1181: cannot open input file

I had the same problem. Solved it by defining a macro OBJECTS that contains all the linker objects e.g.:

OBJECTS = target.exe kernel32.lib mylib.lib (etc)

And then specifying $(OBJECTS) on the linker's command line.

I don't use Visual Studio though, just nmake and a .MAK file

How to store directory files listing into an array?

You may be tempted to use (*) but what if a directory contains the * character? It's very difficult to handle special characters in filenames correctly.

You can use ls -ls. However, it fails to handle newline characters.

# Store la -ls as an array
readarray -t files <<< $(ls -ls)
for (( i=1; i<${#files[@]}; i++ ))
    # Convert current line to an array
    # Get the filename, joining it together any spaces
    echo $fileName

If all you want is the file name, then just use ls:

for fileName in $(ls); do
    echo $fileName

See this article or this this post for more information about some of the difficulties of dealing with special characters in file names.

Array vs ArrayList in performance

It is pretty obvious that array[10] is faster than array.get(10), as the later internally does the same call, but adds the overhead for the function call plus additional checks.

Modern JITs however will optimize this to a degree, that you rarely have to worry about this, unless you have a very performance critical application and this has been measured to be your bottleneck.

TypeError: 'builtin_function_or_method' object is not subscriptable

I think you want


The expression listb.pop is a valid python expression which results in a reference to the pop method, but doesn't actually call that method. You need to add the open and close parentheses to call the method.

Today`s date in an excel macro

Here's an example that puts the Now() value in column A.

Sub move()
    Dim i As Integer
    Dim sh1 As Worksheet
    Dim sh2 As Worksheet
    Dim nextRow As Long
    Dim copyRange As Range
    Dim destRange As Range

    Application.ScreenUpdating = False

        Set sh1 = ActiveWorkbook.Worksheets("Sheet1")
        Set sh2 = ActiveWorkbook.Worksheets("Sheet2")
        Set copyRange = sh1.Range("A1:A5")

        i = Application.WorksheetFunction.CountA(sh2.Range("B:B")) + 4

        Set destRange = sh2.Range("B" & i)

        destRange.Resize(1, copyRange.Rows.Count).Value = Application.Transpose(copyRange.Value)
        destRange.Offset(0, -1).Value = Format(Now(), "MMM-DD-YYYY")


    Application.ScreenUpdating = True

End Sub

There are better ways of getting the last row in column B than using a While loop, plenty of examples around here. Some are better than others but depend on what you're doing and what your worksheet structure looks like. I used one here which assumes that column B is ALL empty except the rows/records you're moving. If that's not the case, or if B1:B3 have some values in them, you'd need to modify or use another method. Or you could just use your loop, but I'd search for alternatives :)

The server is not responding (or the local MySQL server's socket is not correctly configured) in wamp server

I face the same problem and changing

 $cfg['Servers'][$i]['host'] = 'localhost';


 $cfg['Servers'][$i]['host'] = '';

Solved this issue.

PHP output showing little black diamonds with a question mark

I chose to strip these characters out of the string by doing this -

ini_set('mbstring.substitute_character', "none"); 
$text= mb_convert_encoding($text, 'UTF-8', 'UTF-8');

What are the First and Second Level caches in (N)Hibernate?

by default, NHibernate uses first level caching which is Session Object based. but if you are running in a multi-server environment, then the first level cache may not very scalable along with some performance issues. it is happens because of the fact that it has to make very frequent trips to the database as the data is distributed over multiple servers. in other words NHibernate provides a basic, not-so-sophisticated in-process L1 cache out of box. However, it doesn’t provide features that a caching solution must have to have a notable impact on the application performance.

so the questions of all these problem is the use of a L2 cache which is associated with the session factory objects. it reduces the time consuming trips to the database so ultimately increases the app response time.

Check if a list contains an item in Ansible

You do not need {{}} in when conditions. What you are searching for is:

- fail: msg="unsupported version"
  when: version not in acceptable_versions

Header div stays at top, vertical scrolling div below with scrollbar only attached to that div

Here is a demo. Use position:fixed; top:0; left:0; so the header always stay on top.

?#header {
}.scroller {

Add values to app.config and retrieve them

Try adding a Reference to System.Configuration, you get some of the configuration namespace by referencing the System namespace, adding the reference to System.Configuration should allow you to access ConfigurationManager.

Call an overridden method from super class in typescript

The key is calling the parent's method using super.methodName();

class A {
    // A protected method
    protected doStuff()
        alert("Called from A");

    // Expose the protected method as a public function
    public callDoStuff()

class B extends A {

    // Override the protected method
    protected doStuff()
        // If we want we can still explicitly call the initial method
        alert("Called from B");

var a = new A();
a.callDoStuff(); // Will only alert "Called from A"

var b = new B()
b.callDoStuff(); // Will alert "Called from A" then "Called from B"

Try it here

Mathematical functions in Swift

To use the math-functions you have to import Cocoa

You can see the other defined mathematical functions in the following way. Make a Cmd-Click on the function name sqrt and you enter the file with all other global math functions and constanst.

A small snippet of the file

func pow(_: CDouble, _: CDouble) -> CDouble

func sqrtf(_: CFloat) -> CFloat
func sqrt(_: CDouble) -> CDouble

func erff(_: CFloat) -> CFloat
var M_LN10: CDouble { get } /* loge(10)       */
var M_PI: CDouble { get } /* pi             */
var M_PI_2: CDouble { get } /* pi/2           */
var M_SQRT2: CDouble { get } /* sqrt(2)        */

Handling warning for possible multiple enumeration of IEnumerable

If your data is always going to be repeatable, perhaps don't worry about it. However, you can unroll it too - this is especially useful if the incoming data could be large (for example, reading from disk/network):

if(objects == null) throw new ArgumentException();
using(var iter = objects.GetEnumerator()) {
    if(!iter.MoveNext()) throw new ArgumentException();

    var firstObject = iter.Current;
    var list = DoSomeThing(firstObject);  

    while(iter.MoveNext()) {
    return list;

Note I changed the semantic of DoSomethingElse a bit, but this is mainly to show unrolled usage. You could re-wrap the iterator, for example. You could make it an iterator block too, which could be nice; then there is no list - and you would yield return the items as you get them, rather than add to a list to be returned.

Can you write virtual functions / methods in Java?

From wikipedia

In Java, all non-static methods are by default "virtual functions." Only methods marked with the keyword final, which cannot be overridden, along with private methods, which are not inherited, are non-virtual.

How do I get the current year using SQL on Oracle?

Since we are doing this one to death - you don't have to specify a year:

select * from demo
where  somedate between to_date('01/01 00:00:00', 'DD/MM HH24:MI:SS')
                and     to_date('31/12 23:59:59', 'DD/MM HH24:MI:SS');

However the accepted answer by FerranB makes more sense if you want to specify all date values that fall within the current year.

Javascript Uncaught TypeError: Cannot read property '0' of undefined

The error is here:


You are passing the first item of words, instead of the array.

Instead, pass the array to the function:


Problem solved!

Here's a breakdown of what the problem was:

I'm guessing in your browser (chrome throws a different error), words[] == words[0], so when you call hasLetter("a",words[]);, you are actually calling hasLetter("a",words[0]);. So, in essence, you are passing the first item of words to your function, not the array as a whole.

Of course, because words is just an empty array, words[0] is undefined. Therefore, your function call is actually:

hasLetter("a", undefined);

which means that, when you try to access d[ascii], you are actually trying to access undefined[0], hence the error.

How can I make my match non greedy in vim?

If you're more comfortable PCRE regex syntax, which

  1. supports the non-greedy operator ?, as you asked in OP; and
  2. doesn't require backwhacking grouping and cardinality operators (an utterly counterintuitive vim syntax requirement since you're not matching literal characters but specifying operators); and
  3. you have [g]vim compiled with perl feature, test using

    :ver and inspect features; if +perl is there you're good to go)

try search/replace using

:perldo s///

Example. Swap src and alt attributes in img tag:

<p class="logo"><a href="/"><img src="/caminoglobal_en/includes/themes/camino/images/header_logo.png" alt=""></a></p>

:perldo s/(src=".*?")\s+(alt=".*?")/$2 $1/

<p class="logo"><a href="/"><img alt="" src="/caminoglobal_en/includes/themes/camino/images/header_logo.png"></a></p>

Changing Node.js listening port

I usually manually set the port that I am listening on in the app.js file (assuming you are using express.js

var server = app.listen(8080, function() {
    console.log('Ready on port %d', server.address().port);

This will log Ready on port 8080 to your console.

Checking if a list is empty with LINQ

Here's my implementation of Dan Tao's answer, allowing for a predicate:

public static bool IsEmpty<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate)
    if (source == null) throw new ArgumentNullException();
    if (IsCollectionAndEmpty(source)) return true;
    return !source.Any(predicate);

public static bool IsEmpty<TSource>(this IEnumerable<TSource> source)
    if (source == null) throw new ArgumentNullException();
    if (IsCollectionAndEmpty(source)) return true;
    return !source.Any();

private static bool IsCollectionAndEmpty<TSource>(IEnumerable<TSource> source)
    var genericCollection = source as ICollection<TSource>;
    if (genericCollection != null) return genericCollection.Count == 0;
    var nonGenericCollection = source as ICollection;
    if (nonGenericCollection != null) return nonGenericCollection.Count == 0;
    return false;

Interface/enum listing standard mime-type constants

There is now also the class org.apache.http.entity.ContentType from package org.apache.httpcomponents.httpcore, starting from 4.2 up.

Can I get a patch-compatible output from git-diff?

A useful trick to avoid creating temporary patch files:

git diff | patch -p1 -d [dst-dir]

Python IndentationError unindent does not match any outer indentation level

You have mixed indentation formatting (spaces and tabs)

On Notepad++

Change Tab Settings to 4 spaces

Go to Settings -> Preferences -> Tab Settings -> Replace by spaces

Fix the current file mixed indentations

Select everything CTRL+A

Click TAB once, to add an indentation everywhere

Run SHIFT + TAB to remove the extra indentation, it will replace all TAB characters to 4 spaces.

URL encoding in Android

Find Arabic chars and replace them with its UTF-8 encoding. some thing like this:

for (int i = 0; i < urlAsString.length(); i++) {
    if (urlAsString.charAt(i) > 255) {
        urlAsString = urlAsString.substring(0, i) + URLEncoder.encode(urlAsString.charAt(i)+"", "UTF-8") + urlAsString.substring(i+1);
encodedURL = urlAsString;

Is it possible to run JavaFX applications on iOS, Android or Windows Phone 8?

Desktop: first-class support

Oracle JavaFX from Java SE supports only OS X (macOS), GNU/Linux and Microsoft Windows. On these platforms, JavaFX applications are typically run on JVM from Java SE or OpenJDK.

Android: should work

There is also a JavaFXPorts project, which is an open-source project sponsored by a third-party. It aims to port JavaFX library to Android and iOS.

On Android, this library can be used like any other Java library; the JVM bytecode is compiled to Dalvik bytecode. It's what people mean by saying that "Android runs Java".

iOS: status not clear

On iOS, situation is a bit more complex, as neither Java SE nor OpenJDK supports Apple mobile devices. Till recently, the only sensible option was to use RoboVM ahead-of-time Java compiler for iOS. Unfortunately, on 15 April 2015, RoboVM project was shut down.

One possible alternative is Intel's Multi-OS Engine. Till recently, it was a proprietary technology, but on 11 August 2016 it was open-sourced. Although it can be possible to compile an iOS JavaFX app using JavaFXPorts' JavaFX implementation, there is no evidence for that so far. As you can see, the situation is dynamically changing, and this answer will be hopefully updated when new information is available.

Windows Phone: no support

With Windows Phone it's simple: there is no JavaFX support of any kind.

Postgres user does not exist?

psql -U postgres

Worked fine for me in case of db name: postgres & username: postgres. So you do not need to write sudo.

And in the case other db, you may try

psql -U yourdb postgres

As it is given in Postgres help:


How does a Java HashMap handle different objects with the same hash code?

It gonna be a long answer , grab a drink and read on …

Hashing is all about storing a key-value pair in memory that can be read and written faster. It stores keys in an array and values in a LinkedList .

Lets Say I want to store 4 key value pairs -

“girl” => “ahhan” , 
“misused” => “Manmohan Singh” , 
“horsemints” => “guess what”, 
“no” => “way”

So to store the keys we need an array of 4 element . Now how do I map one of these 4 keys to 4 array indexes (0,1,2,3)?

So java finds the hashCode of individual keys and map them to a particular array index . Hashcode Formulae is -

1) reverse the string.

2) keep on multiplying ascii of each character with increasing power of 31 . then add the components .

3) So hashCode() of girl would be –(ascii values of  l,r,i,g are 108, 114, 105 and 103) . 

e.g. girl =  108 * 31^0  + 114 * 31^1  + 105 * 31^2 + 103 * 31^3  = 3173020

Hash and girl !! I know what you are thinking. Your fascination about that wild duet might made you miss an important thing .

Why java multiply it with 31 ?

It’s because, 31 is an odd prime in the form 2^5 – 1 . And odd prime reduces the chance of Hash Collision

Now how this hash code is mapped to an array index?

answer is , Hash Code % (Array length -1) . So “girl” is mapped to (3173020 % 3) = 1 in our case . which is second element of the array .

and the value “ahhan” is stored in a LinkedList associated with array index 1 .

HashCollision - If you try to find hasHCode of the keys “misused” and “horsemints” using the formulae described above you’ll see both giving us same 1069518484. Whooaa !! lesson learnt -

2 equal objects must have same hashCode but there is no guarantee if the hashCode matches then the objects are equal . So it should store both values corresponding to “misused” and “horsemints” to bucket 1 (1069518484 % 3) .

Now the hash map looks like –

Array Index 0 –
Array Index 1 - LinkedIst (“ahhan” , “Manmohan Singh” , “guess what”)
Array Index 2 – LinkedList (“way”)
Array Index 3 – 

Now if some body tries to find the value for the key “horsemints” , java quickly will find the hashCode of it , module it and start searching for it’s value in the LinkedList corresponding index 1 . So this way we need not search all the 4 array indexes thus making data access faster.

But , wait , one sec . there are 3 values in that linkedList corresponding Array index 1, how it finds out which one was was the value for key “horsemints” ?

Actually I lied , when I said HashMap just stores values in LinkedList .

It stores both key value pair as map entry. So actually Map looks like this .

Array Index 0 –
Array Index 1 - LinkedIst (<”girl” => “ahhan”> , <” misused” => “Manmohan Singh”> , <”horsemints” => “guess what”>)
Array Index 2 – LinkedList (<”no” => “way”>)
Array Index 3 – 

Now you can see While traversing through the linkedList corresponding to ArrayIndex1 it actually compares key of each entry to of that LinkedList to “horsemints” and when it finds one it just returns the value of it .

Hope you had fun while reading it :)

How would one write object-oriented code in C?

I'm a bit late to the party, but I want to share my experience on the topic: I work with embedded stuff these days, and the only (reliable) compiler I have is C, so that I want to apply object-oriented approach in my embedded projects written in C.

Most of the solutions I've seen so far use typecasts heavily, so we lose type safety: compiler won't help you if you make a mistake. This is completely unacceptable.

Requirements that I have:

  • Avoid typecasts as much as possible, so we don't lose type safety;
  • Polymorphism: we should be able to use virtual methods, and user of the class should not be aware whether some particular method is virtual or not;
  • Multiple inheritance: I don't use it often, but sometimes I really want some class to implement multiple interfaces (or to extend multiple superclasses).

I've explained my approach in detail in this article: Object-oriented programming in C; plus, there is an utility for autogeneration of boilerplate code for base and derived classes.

Failed to read artifact descriptor for org.apache.maven.plugins:maven-source-plugin:jar:2.4

Remove the content of the folder \.m2\repository\org\apache\maven\plugins\maven-resource-plugin\2.7. The cached info turned out to be the issue.

Loading an image to a <img> from <input file>

In browsers supporting the File API, you can use the FileReader constructor to read files once they have been selected by the user.


document.getElementById('picField').onchange = function (evt) {
    var tgt = || window.event.srcElement,
        files = tgt.files;

    // FileReader support
    if (FileReader && files && files.length) {
        var fr = new FileReader();
        fr.onload = function () {
            document.getElementById(outImage).src = fr.result;

    // Not supported
    else {
        // fallback -- perhaps submit the input to an iframe and temporarily store
        // them on the server until the user's session ends.

Browser support

  • IE 10
  • Safari 6.0.2
  • Chrome 7
  • Firefox 3.6
  • Opera 12.02

Where the File API is unsupported, you cannot (in most security conscious browsers) get the full path of a file from a file input box, nor can you access the data. The only viable solution would be to submit the form to a hidden iframe and have the file pre-uploaded to the server. Then, when that request completes you could set the src of the image to the location of the uploaded file.

Mongoose query where value is not null

Ok guys I found a possible solution to this problem. I realized that joins do not exists in Mongo, that's why first you need to query the user's ids with the role you like, and after that do another query to the profiles document, something like this:

    const exclude: string = '-_id -created_at -gallery -wallet -MaxRequestersPerBooking -active -__v';

  // Get the _ids of users with the role equal to role.
    await User.find({role: role}, {_id: 1, role: 1, name: 1},  function(err, docs) {

        // Map the docs into an array of just the _ids
        var ids = { return doc._id; });

        // Get the profiles whose users are in that set.
        Profile.find({user: {$in: ids}}, function(err, profiles) {
            // docs contains your answer
                code: 200,
                profiles: profiles,
                page: page
            path: 'user',
            select: '-password -verified -_id -__v'
            // group: { role: "$role"} 

Twitter bootstrap float div right

You can assign the class name like text-center, left or right. The text will align accordingly to these class name. You don't need to make extra class name separately. These classes are built in BootStrap 3 and bootstrap 4.

Bootstrap 3

v3 Text Alignment Docs

<p class="text-left">Left aligned text.</p>
<p class="text-center">Center aligned text.</p>
<p class="text-right">Right aligned text.</p>
<p class="text-justify">Justified text.</p>
<p class="text-nowrap">No wrap text.</p>

Bootstrap 4

v4 Text Alignment Docs

<p class="text-xs-left">Left aligned text on all viewport sizes.</p>
<p class="text-xs-center">Center aligned text on all viewport sizes.</p>
<p class="text-xs-right">Right aligned text on all viewport sizes.</p>

<p class="text-sm-left">Left aligned text on viewports sized SM (small) or wider.</p>
<p class="text-md-left">Left aligned text on viewports sized MD (medium) or wider.</p>
<p class="text-lg-left">Left aligned text on viewports sized LG (large) or wider.</p>
<p class="text-xl-left">Left aligned text on viewports sized XL (extra-large) or wider.</p>

Replace input type=file by an image

its really simple you can try this:

$("#image id").click(function(){
    $("#input id").click();

How to select the row with the maximum value in each group

One more base R solution:

merge(aggregate(pt ~ Subject, max, data = group), group)

  Subject pt Event
1       1  5     2
2       2 17     2
3       3  5     2

How can I check for NaN values?

I am receiving the data from a web-service that sends NaN as a string 'Nan'. But there could be other sorts of string in my data as well, so a simple float(value) could throw an exception. I used the following variant of the accepted answer:

def isnan(value):
      import math
      return math.isnan(float(value))
      return False


isnan('hello') == False
isnan('NaN') == True
isnan(100) == False
isnan(float('nan')) = True

Regarding C++ Include another class

When you want to convert your code to result( executable, library or whatever ), there is 2 steps:
1) compile
2) link
In first step compiler should now about some things like sizeof objects that used by you, prototype of functions and maybe inheritance. on the other hand linker want to find implementation of functions and global variables in your code.

Now when you use ClassTwo in File1.cpp compiler know nothing about it and don't know how much memory should allocate for it or for example witch members it have or is it a class and enum or even a typedef of int, so compilation will be failed by the compiler. adding File2.cpp solve the problem of linker that look for implementation but the compiler is still unhappy, because it know nothing about your type.

So remember, in compile phase you always work with just one file( and of course files that included by that one file ) and in link phase you need multiple files that contain implementations. and since C/C++ are statically typed and they allow their identifier to work for many purposes( definition, typedef, enum class, ... ) so you should always identify you identifier to the compiler and then use it and as a rule compiler should always know size of your variable!!

jQuery change URL of form submit

Send the data from the form:

$("#change_section_type").live "change", ->
url = $(this).attr("data-url")
postData = $(this).parents("#contract_setting_form").serializeArray()
  type: "PUT"
  url: url
  dataType: "script"
  data: postData

How to Execute SQL Script File in Java?

The Apache iBatis solution worked like a charm.

The script example I used was exactly the script I was running from MySql workbench.

There is an article with examples here:,to%20pass%20a%20connection%20object.&text=Register%20the%20MySQL%20JDBC%20Driver,method%20of%20the%20DriverManager%20class.

This is what I did:

pom.xml dependency

<!-- IBATIS SQL Script runner from Apache ( -->

Code to execute script:

import java.sql.Connection;   
import org.apache.ibatis.jdbc.ScriptRunner;   
import lombok.extern.slf4j.Slf4j;

public class SqlScriptExecutor {

    public static void executeSqlScript(File file, Connection conn) throws Exception {
        Reader reader = new BufferedReader(new FileReader(file));"Running script from file: " + file.getCanonicalPath());
        ScriptRunner sr = new ScriptRunner(conn);

GitHub: invalid username or password

Disabling 2 factor authentication at github worked for me.

I see that there is a deleted answer that says this, with the deletion reason as "does not answer the question". If it works, then I think it answers the question...

Increase bootstrap dropdown menu width

Add the following css class

.dropdown-menu {
    width: 300px !important;
    height: 400px !important;

Of course you can use what matches your need.

how to change attribute "hidden" in jquery

You can use jquery attr method


Android button background color

Create /res/drawable/button.xml with the following content :

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
android:shape="rectangle" android:padding="10dp">
<!-- you can use any color you want I used here gray color-->
 <solid android:color="#90EE90"/> 

And then you can use the following :


ASP.NET MVC Bundle not rendering script files on staging server. It works on development server

By adding following code of line in bundle to config it works for me


Follow the link for more explanation

Format number to 2 decimal places

How about CAST(2229.999 AS DECIMAL(6,2)) to get a decimal with 2 decimal places

ModelState.AddModelError - How can I add an error that isn't for a property?

Putting the model dot property in strings worked for me: ModelState.AddModelError("Item1.Month", "This is not a valid date");

SQL select statements with multiple tables

First select all record from person table, then join all these record with another table 'Address' u have record of all the persons who have their address in address finally filter your record by zipcode.

 select * from Person as P inner join Address as A on = A.person_id Where'97229'

Two color borders

This produces a nice effect.

<div style="border: 1px solid gray; padding: 1px">
<div style="border: 1px solid gray">
   internal stuff

Concatenating null strings in Java

See section 5.4 and 15.18 of the Java Language specification:

String conversion applies only to the operands of the binary + operator when one of the arguments is a String. In this single special case, the other argument to the + is converted to a String, and a new String which is the concatenation of the two strings is the result of the +. String conversion is specified in detail within the description of the string concatenation + operator.


If only one operand expression is of type String, then string conversion is performed on the other operand to produce a string at run time. The result is a reference to a String object (newly created, unless the expression is a compile-time constant expression (§15.28))that is the concatenation of the two operand strings. The characters of the left-hand operand precede the characters of the right-hand operand in the newly created string. If an operand of type String is null, then the string "null" is used instead of that operand.

What is "git remote add ..." and "git push origin master"?

Have a look at the syntax for adding a remote repo.

git remote add origin <url_of_remote repository>


git remote add origin [email protected]:peter/first_app.git

Let us dissect the command :

git remote this is used to manage your Central servers for hosting your git repositories.

May be you are using Github for your central repository stuff. I will give you a example and explain the git remote add origin command

Suppose I am working with GitHub and BitBucket for the central servers for the git repositories and have created repositories on both the websites for my first-app project.

Now if I want to push my changes to both these git servers then I will need to tell git how to reach these central repositories. So I will have to add these,

For GitHub

git remote add gh_origin

And For BitBucket

git remote add bb_origin https://[email protected]/user/first-app-git.git

I have used two variables ( as far it is easy for me to call them variables ) gh_origin ( gh FOR GITHUB ) and bb_origin ( bb for BITBUCKET ) just to explain you we can call origin anything we want.

Now after making some changes I will have to send(push) all these changes to central repositories so that other users can see these changes. So I call

Pushing to GitHub

git push gh_origin master

Pushing to BitBucket

git push bb_origin master

gh_origin is holding value of and bb_origin is holding value of https://[email protected]/user/first-app-git.git

This two variables are making my life easier

as whenever I need to send my code changes I need to use this words instead of remembering or typing the URL for the same.

Most of the times you wont see anything except than origin as most of the times you will deal with only one central repository like Github or BitBucket for example.

How can I concatenate two arrays in Java?

Non Java 8 solution:

public static int[] combineArrays(int[] a, int[] b) {
        int[] c = new int[a.length + b.length];

        for (int i = 0; i < a.length; i++) {
            c[i] = a[i];

        for (int j = 0, k = a.length; j < b.length; j++, k++) {
            c[k] = b[j];

        return c;

HTML5 video - show/hide controls programmatically

<video id="myvideo">
  <source src="path/to/movie.mp4" />

<p onclick="toggleControls();">Toggle</p>

var video = document.getElementById("myvideo");

function toggleControls() {
  if (video.hasAttribute("controls")) {
  } else {

See it working on jsFiddle:

Entity Framework Queryable async

The problem seems to be that you have misunderstood how async/await work with Entity Framework.

About Entity Framework

So, let's look at this code:

public IQueryable<URL> GetAllUrls()
    return context.Urls.AsQueryable();

and example of it usage:

repo.GetAllUrls().Where(u => <condition>).Take(10).ToList()

What happens there?

  1. We are getting IQueryable object (not accessing database yet) using repo.GetAllUrls()
  2. We create a new IQueryable object with specified condition using .Where(u => <condition>
  3. We create a new IQueryable object with specified paging limit using .Take(10)
  4. We retrieve results from database using .ToList(). Our IQueryable object is compiled to sql (like select top 10 * from Urls where <condition>). And database can use indexes, sql server send you only 10 objects from your database (not all billion urls stored in database)

Okay, let's look at first code:

public async Task<IQueryable<URL>> GetAllUrlsAsync()
    var urls = await context.Urls.ToListAsync();
    return urls.AsQueryable();

With the same example of usage we got:

  1. We are loading in memory all billion urls stored in your database using await context.Urls.ToListAsync();.
  2. We got memory overflow. Right way to kill your server

About async/await

Why async/await is preferred to use? Let's look at this code:

var stuff1 = repo.GetStuff1ForUser(userId);
var stuff2 = repo.GetStuff2ForUser(userId);
return View(new Model(stuff1, stuff2));

What happens here?

  1. Starting on line 1 var stuff1 = ...
  2. We send request to sql server that we want to get some stuff1 for userId
  3. We wait (current thread is blocked)
  4. We wait (current thread is blocked)
  5. .....
  6. Sql server send to us response
  7. We move to line 2 var stuff2 = ...
  8. We send request to sql server that we want to get some stuff2 for userId
  9. We wait (current thread is blocked)
  10. And again
  11. .....
  12. Sql server send to us response
  13. We render view

So let's look to an async version of it:

var stuff1Task = repo.GetStuff1ForUserAsync(userId);
var stuff2Task = repo.GetStuff2ForUserAsync(userId);
await Task.WhenAll(stuff1Task, stuff2Task);
return View(new Model(stuff1Task.Result, stuff2Task.Result));

What happens here?

  1. We send request to sql server to get stuff1 (line 1)
  2. We send request to sql server to get stuff2 (line 2)
  3. We wait for responses from sql server, but current thread isn't blocked, he can handle queries from another users
  4. We render view

Right way to do it

So good code here:

using System.Data.Entity;

public IQueryable<URL> GetAllUrls()
   return context.Urls.AsQueryable();

public async Task<List<URL>> GetAllUrlsByUser(int userId) {
   return await GetAllUrls().Where(u => u.User.Id == userId).ToListAsync();

Note, than you must add using System.Data.Entity in order to use method ToListAsync() for IQueryable.

Note, that if you don't need filtering and paging and stuff, you don't need to work with IQueryable. You can just use await context.Urls.ToListAsync() and work with materialized List<Url>.

Lining up labels with radio buttons in bootstrap

This may work for you, Please try this.

  <div class="form-inline">
    <div class="controls-row">
      <label class="control-label">Some label</label>
      <label class="radio inline">
        <input type="radio" value="1" />First
      <label class="radio inline">
        <input type="radio" value="2" />Second

C++ int float casting

he does an integer divide, which means 3 / 4 = 0. cast one of the brackets to float

 (float)(a.y - b.y) / (a.x - b.x);

Excel date to Unix timestamp

Here is a mapping for reference, assuming UTC for spreadsheet systems like Microsoft Excel:

                         Unix  Excel Mac    Excel    Human Date  Human Time
Excel Epoch       -2209075200      -1462        0    1900/01/00* 00:00:00 (local)
Excel = 2011 Mac† -2082758400          0     1462    1904/12/31  00:00:00 (local)
Unix Epoch                  0      24107    25569    1970/01/01  00:00:00 UTC
Example Below      1234567890      38395.6  39857.6  2009/02/13  23:31:30 UTC
Signed Int Max     2147483648      51886    50424    2038/01/19  03:14:08 UTC

One Second                  1       0.0000115740…             —  00:00:01
One Hour                 3600       0.0416666666…             -  01:00:00
One Day                 86400          1        1             -  24:00:00

*  “Jan Zero, 1900” is 1899/12/31; see the Bug section below. Excel 2011 for Mac (and older) use the 1904 date system.


As I often use awk to process CSV and space-delimited content, I developed a way to convert UNIX epoch to timezone/DST-appropriate Excel date format:

echo 1234567890 |awk '{ 
  # tries GNU date, tries BSD date on failure
  cmd = sprintf("date -d@%d +%%z 2>/dev/null || date -jf %%s %d +%%z", $1, $1)
  cmd |getline tz                                # read in time-specific offset
  hours = substr(tz, 2, 2) + substr(tz, 4) / 60  # hours + minutes (hi, India)
  if (tz ~ /^-/) hours *= -1                     # offset direction (east/west)
  excel = $1/86400 + hours/24 + 25569            # as days, plus offset
  printf "%.9f\n", excel

I used echo for this example, but you can pipe a file where the first column (for the first cell in .csv format, call it as awk -F,) is a UNIX epoch. Alter $1 to represent your desired column/cell number or use a variable instead.

This makes a system call to date. If you will reliably have the GNU version, you can remove the 2>/dev/null || date … +%%z and the second , $1. Given how common GNU is, I wouldn't recommend assuming BSD's version.

The getline reads the time zone offset outputted by date +%z into tz, which is then translated into hours. The format will be like -0700 (PDT) or +0530 (IST), so the first substring extracted is 07 or 05, the second is 00 or 30 (then divided by 60 to be expressed in hours), and the third use of tz sees whether our offset is negative and alters hours if needed.

The formula given in all of the other answers on this page is used to set excel, with the addition of the daylight-savings-aware time zone adjustment as hours/24.

If you're on an older version of Excel for Mac, you'll need to use 24107 in place of 25569 (see the mapping above).

To convert any arbitrary non-epoch time to Excel-friendly times with GNU date:

echo "last thursday" |awk '{ 
  cmd = sprintf("date -d \"%s\" +\"%%s %%z\"", $0)
  cmd |getline
  hours = substr($2, 2, 2) + substr($2, 4) / 60
  if ($2 ~ /^-/) hours *= -1
  excel = $1/86400 + hours/24 + 25569
  printf "%.9f\n", excel

This is basically the same code, but the date -d no longer has an @ to represent unix epoch (given how capable the string parser is, I'm actually surprised the @ is mandatory; what other date format has 9-10 digits?) and it's now asked for two outputs: the epoch and the time zone offset. You could therefore use e.g. @1234567890 as an input.


Lotus 1-2-3 (the original spreadsheet software) intentionally treated 1900 as a leap year despite the fact that it was not (this reduced the codebase at a time when every byte counted). Microsoft Excel retained this bug for compatibility, skipping day 60 (the fictitious 1900/02/29), retaining Lotus 1-2-3's mapping of day 59 to 1900/02/28. LibreOffice instead assigned day 60 to 1900/02/28 and pushed all previous days back one.

Any date before 1900/03/01 could be as much as a day off:

Day        Excel   LibreOffice
-1            -1    1899/12/29
 0    1900/01/00*   1899/12/30
 1    1900/01/01    1899/12/31
 2    1900/01/02    1900/01/01
59    1900/02/28    1900/02/27
60    1900/02/29(!) 1900/02/28
61    1900/03/01    1900/03/01

Excel doesn't acknowledge negative dates and has a special definition of the Zeroth of January (1899/12/31) for day zero. Internally, Excel does indeed handle negative dates (they're just numbers after all), but it displays them as numbers since it doesn't know how to display them as dates (nor can it convert older dates into negative numbers). Feb 29 1900, a day that never happened, is recognized by Excel but not LibreOffice.

How to convert milliseconds to seconds with precision

I had this problem too, somehow my code did not present the exact values but rounded the number in seconds to 0.0 (if milliseconds was under 1 second). What helped me out is adding the decimal to the division value.

double time_seconds = time_milliseconds / 1000.0;   // add the decimal
System.out.println(time_milliseconds);              // Now this should give you the right value.

Double quotes within php script echo

You need to escape the quotes in the string by adding a backslash \ before ".


"<font color=\"red\">"

Load arrayList data into JTable

You probably need to use a TableModel (Oracle's tutorial here)

How implements your own TableModel

public class FootballClubTableModel extends AbstractTableModel {
  private List<FootballClub> clubs ;
  private String[] columns ; 

  public FootBallClubTableModel(List<FootballClub> aClubList){
    clubs = aClubList ;
    columns = new String[]{"Pos","Team","P", "W", "L", "D", "MP", "GF", "GA", "GD"};

  // Number of column of your table
  public int getColumnCount() {
    return columns.length ;

  // Number of row of your table
  public int getRowsCount() {
    return clubs.size();

  // The object to render in a cell
  public Object getValueAt(int row, int col) {
    FootballClub club = clubs.get(row);
    switch(col) {
      case 0: return club.getPosition();
      // to complete here...
      default: return null;

  // Optional, the name of your column
  public String getColumnName(int col) {
    return columns[col] ;


You maybe need to override anothers methods of TableModel, depends on what you want to do, but here is the essential methods to understand and implements :)
Use it like this

List<FootballClub> clubs = getFootballClub();
TableModel model = new FootballClubTableModel(clubs);
JTable table = new JTable(model);

Hope it help !

MIT vs GPL license

Can I include GPL licensed code in a MIT licensed product?

You can. GPL is free software as well as MIT is, both licenses do not restrict you to bring together the code where as "include" is always two-way.

In copyright for a combined work (that is two or more works form together a work), it does not make much of a difference if the one work is "larger" than the other or not.

So if you include GPL licensed code in a MIT licensed product you will at the same time include a MIT licensed product in GPL licensed code as well.

As a second opinion, the OSI listed the following criteria (in more detail) for both licenses (MIT and GPL):

  1. Free Redistribution
  2. Source Code
  3. Derived Works
  4. Integrity of The Author's Source Code
  5. No Discrimination Against Persons or Groups
  6. No Discrimination Against Fields of Endeavor
  7. Distribution of License
  8. License Must Not Be Specific to a Product
  9. License Must Not Restrict Other Software
  10. License Must Be Technology-Neutral

Both allow the creation of combined works, which is what you've been asking for.

If combining the two works is considered being a derivate, then this is not restricted as well by both licenses.

And both licenses do not restrict to distribute the software.

It seems to me that the chief difference between the MIT license and GPL is that the MIT doesn't require modifications be open sourced whereas the GPL does.

The GPL doesn't require you to release your modifications only because you made them. That's not precise.

You might mix this with distribiution of software under GPL which is not what you've asked about directly.

Is that correct - is the GPL is more restrictive than the MIT license?

This is how I understand it:

As far as distribution counts, you need to put the whole package under GPL. MIT code inside of the package will still be available under MIT whereas the GPL applies to the package as a whole if not limited by higher rights.

"Restrictive" or "more restrictive" / "less restrictive" depends a lot on the point of view. For a software-user the MIT might result in software that is more restricted than the one available under GPL even some call the GPL more restrictive nowadays. That user in specific will call the MIT more restrictive. It's just subjective to say so and different people will give you different answers to that.

As it's just subjective to talk about restrictions of different licenses, you should think about what you would like to achieve instead:

  • If you want to restrict the use of your modifications, then MIT is able to be more restrictive than the GPL for distribution and that might be what you're looking for.
  • In case you want to ensure that the freedom of your software does not get restricted that much by the users you distribute it to, then you might want to release under GPL instead of MIT.

As long as you're the author it's you who can decide.

So the most restrictive person ever is the author, regardless of which license anybody is opting for ;)

Getting the difference between two Dates (months/days/hours/minutes/seconds) in Swift

--> Use this to find time gap between two dates in Swift(With two Strings).

func timeGapBetweenDates(previousDate : String,currentDate : String)
    let dateString1 = previousDate
    let dateString2 = currentDate

    let Dateformatter = DateFormatter()
    Dateformatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

    let date1 = dateString1)
    let date2 = dateString2)

    let distanceBetweenDates: TimeInterval? = date2?.timeIntervalSince(date1!)
    let secondsInAnHour: Double = 3600
    let minsInAnHour: Double = 60
    let secondsInDays: Double = 86400
    let secondsInWeek: Double = 604800
    let secondsInMonths : Double = 2592000
    let secondsInYears : Double = 31104000

    let minBetweenDates = Int((distanceBetweenDates! / minsInAnHour))
    let hoursBetweenDates = Int((distanceBetweenDates! / secondsInAnHour))
    let daysBetweenDates = Int((distanceBetweenDates! / secondsInDays))
    let weekBetweenDates = Int((distanceBetweenDates! / secondsInWeek))
    let monthsbetweenDates = Int((distanceBetweenDates! / secondsInMonths))
    let yearbetweenDates = Int((distanceBetweenDates! / secondsInYears))
    let secbetweenDates = Int(distanceBetweenDates!)

    if yearbetweenDates > 0
        print(yearbetweenDates,"years")//0 years
    else if monthsbetweenDates > 0
        print(monthsbetweenDates,"months")//0 months
    else if weekBetweenDates > 0
        print(weekBetweenDates,"weeks")//0 weeks
    else if daysBetweenDates > 0
        print(daysBetweenDates,"days")//5 days
    else if hoursBetweenDates > 0
        print(hoursBetweenDates,"hours")//120 hours
    else if minBetweenDates > 0
        print(minBetweenDates,"minutes")//7200 minutes
    else if secbetweenDates > 0

How to set full calendar to a specific start date when it's initialized for the 1st time?

You can just pass a Date object:
For current date:

    defaultDate: new Date()

For specific date '2016-05-20':

    defaultDate: new Date(2016, 4, 20)

How to update values in a specific row in a Python Pandas DataFrame?

Update null elements with value in the same location in other. Combines a DataFrame with other DataFrame using func to element-wise combine columns. The row and column indexes of the resulting DataFrame will be the union of the two.

df1 = pd.DataFrame({'A': [None, 0], 'B': [None, 4]})
df2 = pd.DataFrame({'A': [1, 1], 'B': [3, 3]})
     A    B
0  1.0  3.0
1  0.0  4.0

more information in this link

How can I nullify css property?

An initial keyword is being added in CSS3 to allow authors to explicitly specify this initial value.

try/catch with InputMismatchException creates infinite loop

another option is to define Scanner input = new Scanner(; inside the try block, this will create a new object each time you need to re-enter the values.

Laravel - Pass more than one variable to view

Passing multiple variables to a Laravel view

//Passing variable to view using compact method    
return view('viewName', compact('var1','var2','var3'));

//Passing variable to view using with Method
return view('viewName')->with(['var1'=>value1,'var2'=>value2,'var3'=>'value3']);

//Passing variable to view using Associative Array
return view('viewName', ['var1'=>value1,'var2'=>value2,'var3'=>value3]);

Read here about Passing Data to Views in Laravel

What is the difference between Step Into and Step Over in a debugger

Consider the following code with your current instruction pointer (the line that will be executed next, indicated by ->) at the f(x) line in g(), having been called by the g(2) line in main():

public class testprog {
    static void f (int x) {
        System.out.println ("num is " + (x+0)); // <- STEP INTO

    static void g (int x) {
->      f(x); //
        f(1); // <----------------------------------- STEP OVER

    public static void main (String args[]) {
        g(3); // <----------------------------------- STEP OUT OF

If you were to step into at that point, you will move to the println() line in f(), stepping into the function call.

If you were to step over at that point, you will move to the f(1) line in g(), stepping over the function call.

Another useful feature of debuggers is the step out of or step return. In that case, a step return will basically run you through the current function until you go back up one level. In other words, it will step through f(x) and f(1), then back out to the calling function to end up at g(3) in main().

Why does this CSS margin-top style not work?

You're actually seeing the top margin of the #inner element collapse into the top edge of the #outer element, leaving only the #outer margin intact (albeit not shown in your images). The top edges of both boxes are flush against each other because their margins are equal.

Here are the relevant points from the W3C spec:

8.3.1 Collapsing margins

In CSS, the adjoining margins of two or more boxes (which might or might not be siblings) can combine to form a single margin. Margins that combine this way are said to collapse, and the resulting combined margin is called a collapsed margin.

Adjoining vertical margins collapse [...]

Two margins are adjoining if and only if:

  • both belong to in-flow block-level boxes that participate in the same block formatting context
  • no line boxes, no clearance, no padding and no border separate them
  • both belong to vertically-adjacent box edges, i.e. form one of the following pairs:
    • top margin of a box and top margin of its first in-flow child

You can do any of the following to prevent the margin from collapsing:

The reason the above options prevent the margin from collapsing is because:

  • Margins between a floated box and any other box do not collapse (not even between a float and its in-flow children).
  • Margins of elements that establish new block formatting contexts (such as floats and elements with 'overflow' other than 'visible') do not collapse with their in-flow children.
  • Margins of inline-block boxes do not collapse (not even with their in-flow children).

The left and right margins behave as you expect because:

Horizontal margins never collapse.

Force HTML5 youtube video

Inline tag is used to add another src of document to the current html element.

In your case an video of a youtube and we need to specify the html type(4 or 5) to the browser externally to the link

so add ?html=5 to the end of the link.. :)

How do I set a fixed background image for a PHP file?

You should consider have other php files included if you're going to derive a website from it. Instead of doing all the css/etc in that file, you can do

    <?php include_once('C:\Users\George\Documents\HTML\style.css'); ?>

Then you can have a separate CSS file that is just being pulled into your php file. It provides some "neater" coding.

how to convert rgb color to int in java

If you are developing for Android, Color's method for this is rgb(int, int, int)

So you would do something like

myPaint.setColor(Color.rgb(int, int, int)); 

For retrieving the individual color values you can use the methods for doing so: color) color) color) 

Refer to this document for more info

Installing RubyGems in Windows

Installing Ruby

Go to

Make sure that you check "Add ruby ... to your PATH". enter image description here

Now you can use "ruby" in your "cmd".

If you installed ruby 1.9.3 I expect that the ruby is downloaded in C:\Ruby193.

Installing Gem

install Development Kit in rubyinstaller. Make new folder such as C:\RubyDevKit and unzip.

Go to the devkit directory and type ruby dk.rb init to generate config.yml.

If you installed devkit for 1.9.3, I expect that the config.yml will be written as C:\Ruby193.

If not, please correct path to your ruby folders.

After reviewing the config.yml, you can finally type ruby dk.rb install.

Now you can use "gem" in your "cmd". It's done!

Returning multiple objects in an R function

Unlike many other languages, R functions don't return multiple objects in the strict sense. The most general way to handle this is to return a list object. So if you have an integer foo and a vector of strings bar in your function, you could create a list that combines these items:

foo <- 12
bar <- c("a", "b", "e")
newList <- list("integer" = foo, "names" = bar)

Then return this list.

After calling your function, you can then access each of these with newList$integer or newList$names.

Other object types might work better for various purposes, but the list object is a good way to get started.

Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

As biziclop mentioned, some sort of metric space tree would probably be your best option. I have experience using kd-trees and quad trees to do these sorts of range queries and they're amazingly fast; they're also not that hard to write. I'd suggest looking into one of these structures, as they also let you answer other interesting questions like "what's the closest point in my data set to this other point?"

prevent iphone default keyboard when focusing an <input>

@rene-pot is correct. You will however have a not-allowed sign on the desktop version of the website. Way around this, apply the readonly="true" to a div that will show up on the mobile view only and not on desktop. See what we did here

What are the pros and cons of parquet format compared to other formats?

I think the main difference I can describe relates to record oriented vs. column oriented formats. Record oriented formats are what we're all used to -- text files, delimited formats like CSV, TSV. AVRO is slightly cooler than those because it can change schema over time, e.g. adding or removing columns from a record. Other tricks of various formats (especially including compression) involve whether a format can be split -- that is, can you read a block of records from anywhere in the dataset and still know it's schema? But here's more detail on columnar formats like Parquet.

Parquet, and other columnar formats handle a common Hadoop situation very efficiently. It is common to have tables (datasets) having many more columns than you would expect in a well-designed relational database -- a hundred or two hundred columns is not unusual. This is so because we often use Hadoop as a place to denormalize data from relational formats -- yes, you get lots of repeated values and many tables all flattened into a single one. But it becomes much easier to query since all the joins are worked out. There are other advantages such as retaining state-in-time data. So anyway it's common to have a boatload of columns in a table.

Let's say there are 132 columns, and some of them are really long text fields, each different column one following the other and use up maybe 10K per record.

While querying these tables is easy with SQL standpoint, it's common that you'll want to get some range of records based on only a few of those hundred-plus columns. For example, you might want all of the records in February and March for customers with sales > $500.

To do this in a row format the query would need to scan every record of the dataset. Read the first row, parse the record into fields (columns) and get the date and sales columns, include it in your result if it satisfies the condition. Repeat. If you have 10 years (120 months) of history, you're reading every single record just to find 2 of those months. Of course this is a great opportunity to use a partition on year and month, but even so, you're reading and parsing 10K of each record/row for those two months just to find whether the customer's sales are > $500.

In a columnar format, each column (field) of a record is stored with others of its kind, spread all over many different blocks on the disk -- columns for year together, columns for month together, columns for customer employee handbook (or other long text), and all the others that make those records so huge all in their own separate place on the disk, and of course columns for sales together. Well heck, date and months are numbers, and so are sales -- they are just a few bytes. Wouldn't it be great if we only had to read a few bytes for each record to determine which records matched our query? Columnar storage to the rescue!

Even without partitions, scanning the small fields needed to satisfy our query is super-fast -- they are all in order by record, and all the same size, so the disk seeks over much less data checking for included records. No need to read through that employee handbook and other long text fields -- just ignore them. So, by grouping columns with each other, instead of rows, you can almost always scan less data. Win!

But wait, it gets better. If your query only needed to know those values and a few more (let's say 10 of the 132 columns) and didn't care about that employee handbook column, once it had picked the right records to return, it would now only have to go back to the 10 columns it needed to render the results, ignoring the other 122 of the 132 in our dataset. Again, we skip a lot of reading.

(Note: for this reason, columnar formats are a lousy choice when doing straight transformations, for example, if you're joining all of two tables into one big(ger) result set that you're saving as a new table, the sources are going to get scanned completely anyway, so there's not a lot of benefit in read performance, and because columnar formats need to remember more about the where stuff is, they use more memory than a similar row format).

One more benefit of columnar: data is spread around. To get a single record, you can have 132 workers each read (and write) data from/to 132 different places on 132 blocks of data. Yay for parallelization!

And now for the clincher: compression algorithms work much better when it can find repeating patterns. You could compress AABBBBBBCCCCCCCCCCCCCCCC as 2A6B16C but ABCABCBCBCBCCCCCCCCCCCCCC wouldn't get as small (well, actually, in this case it would, but trust me :-) ). So once again, less reading. And writing too.

So we read a lot less data to answer common queries, it's potentially faster to read and write in parallel, and compression tends to work much better.

Columnar is great when your input side is large, and your output is a filtered subset: from big to little is great. Not as beneficial when the input and outputs are about the same.

But in our case, Impala took our old Hive queries that ran in 5, 10, 20 or 30 minutes, and finished most in a few seconds or a minute.

Hope this helps answer at least part of your question!

Undoing a git rebase

In case you had pushed your branch to remote repository (usually it's origin) and then you've done a succesfull rebase (without merge) (git rebase --abort gives "No rebase in progress") you can easily reset branch using command:

git reset --hard origin/{branchName}


$ ~/work/projects/{ProjectName} $ git status
On branch {branchName}
Your branch is ahead of 'origin/{branchName}' by 135 commits.
  (use "git push" to publish your local commits)

nothing to commit, working directory clean

$ ~/work/projects/{ProjectName} $ git reset --hard origin/{branchName}
HEAD is now at 6df5719 "Commit message".

$ ~/work/projects/{ProjectName} $ git status
On branch {branchName}
Your branch is up-to-date with 'origin/{branchName}.

nothing to commit, working directory clean

Laravel: PDOException: could not find driver

You are probably missing sqlite or the specific DB driver you are trying to migrate.

Install the DB driver and you'd be fine. You don't necessarily need to edit your php.ini file (it's one way to fix it too though).

For sqlite do --> sudo apt-get install php-sqlite3 Then php artisan migrate

NB: I assume you have PHP and MySql already installed

Good ways to manage a changelog using git?

The gitlog-to-changelog script comes in handy to generate a GNU-style ChangeLog.

As shown by gitlog-to-changelog --help, you may select the commits used to generate a ChangeLog file using either the option --since:

gitlog-to-changelog --since=2008-01-01 > ChangeLog

or by passing additional arguments after --, which will be passed to git-log (called internally by gitlog-to-changelog):

gitlog-to-changelog -- -n 5 foo > last-5-commits-to-branch-foo

For instance, I am using the following rule in the top-level of one of my projects:

.PHONY: update-ChangeLog
    if test -d $(srcdir)/.git; then                         \
       $(srcdir)/build-aux/gitlog-to-changelog              \
          --format='%s%n%n%b%n' --no-cluster                \
          --strip-tab --strip-cherry-pick                   \
          -- $$(cat $(srcdir)/.last-cl-gen)..               \
        >ChangeLog.tmp                                      \
      && git rev-list -n 1 HEAD >.last-cl-gen.tmp           \
      && (echo; cat $(srcdir)/ChangeLog) >>ChangeLog.tmp    \
      && mv -f ChangeLog.tmp $(srcdir)/ChangeLog            \
      && mv -f .last-cl-gen.tmp $(srcdir)/.last-cl-gen      \
      && rm -f ChangeLog.tmp;                               \

EXTRA_DIST += .last-cl-gen

This rule is used at release time to update ChangeLog with the latest not-yet-recorded commit messages. The file .last-cl-gen contains the SHA1 identifier of the latest commit recorded in ChangeLog and is stored in the Git repository. ChangeLog is also recorded in the repository, so that it can be edited (e.g. to correct typos) without altering the commit messages.

Javascript: getFullyear() is not a function

Try this...

 var start = new Date(document.getElementById('Stardate').value);
 var y = start.getFullYear();

Abstract methods in Java

If you use the java keyword abstract you cannot provide an implementation.

Sometimes this idea comes from having a background in C++ and mistaking the virtual keyword in C++ as being "almost the same" as the abstract keyword in Java.

In C++ virtual indicates that a method can be overridden and polymorphism will follow, but abstract in Java is not the same thing. In Java abstract is more like a pure virtual method, or one where the implementation must be provided by a subclass. Since Java supports polymorphism without the need to declare it, all methods are virtual from a C++ point of view. So if you want to provide a method that might be overridden, just write it as a "normal" method.

Now to protect a method from being overridden, Java uses the keyword final in coordination with the method declaration to indicate that subclasses cannot override the method.

How to set time to a date object in java

Calendar cal = Calendar.getInstance();

Date d = cal.getTime();

Also See

jquery multiple checkboxes array

If you have a class for each of your input box, then you can do it as

        var checked = []
        $('input.Booking').each(function ()

How do I check to see if a value is an integer in MySQL?

To check if a value is Int in Mysql, we can use the following query. This query will give the rows with Int values

SELECT col1 FROM table WHERE concat('',col * 1) = col;

SpringMVC RequestMapping for GET parameters

Use @RequestParam in your method arguments so Spring can bind them, also use the @RequestMapping.params array to narrow the method that will be used by spring. Sample code:

params = {"_search", "nd", "rows", "page", "sidx", "sort"})
public @ResponseBody GridModel getUsersForGrid(
@RequestParam(value = "_search") String search, 
@RequestParam(value = "nd") int nd, 
@RequestParam(value = "rows") int rows, 
@RequestParam(value = "page") int page, 
@RequestParam(value = "sidx") int sidx, 
@RequestParam(value = "sort") Sort sort) {
// Stuff here

This way Spring will only execute this method if ALL PARAMETERS are present saving you from null checking and related stuff.

Laravel 5 Carbon format datetime

Declare in model:

class ModelName extends Model

 protected $casts = [
    'created_at' => 'datetime:d/m/Y', // Change your format
    'updated_at' => 'datetime:d/m/Y',

Hiding a button in Javascript


is very useful, but it will still take up space on the page. You can also use


because that will not only hide the object, but make it so that it doesn't take up space until it is displayed. (Also keep in mind that display's opposite is "block," not "visible")

How to remove leading zeros from alphanumeric text?

If you (like me) need to remove all the leading zeros from each "word" in a string, you can modify @polygenelubricants' answer to the following:

String s = "003 d0g 00ss 00 0 00";
s.replaceAll("\\b0+(?!\\b)", "");

which results in:

3 d0g ss 0 0 0

Get length of array?

Length of an array:


UBound alone is not the best method for getting the length of every array as arrays in VBA can start at different indexes, e.g Dim arr(2 to 10)

UBound will return correct results only if the array is 1-based (starts indexing at 1 e.g. Dim arr(1 to 10). It will return wrong results in any other circumstance e.g. Dim arr(10)

More on the VBA Array in this VBA Array tutorial.

What is the difference between JavaScript and ECMAScript?

ECMAScript is a standard for JavaScript, look at these statements from MDN:

enter image description here


JavaScript (JS) is a lightweight interpreted or JIT-compiled programming language with first-class functions. While it is most well-known as the scripting language for Web pages, many non-browser environments also use it, such as node.js, Apache CouchDB and Adobe Acrobat. JavaScript is a prototype-based, multi-paradigm, dynamic language, supporting object-oriented, imperative, and declarative (e.g. functional programming) styles. Read more about JavaScript.


The standard for JavaScript is ECMAScript. As of 2012, all modern browsers fully support ECMAScript 5.1. Older browsers support at least ECMAScript 3. On June 17, 2015, ECMA International published the sixth major version of ECMAScript, which is officially called ECMAScript 2015, and was initially referred to as ECMAScript 6 or ES6. Since then, ECMAScript standards are on yearly release cycles. This documentation refers to the latest draft version, which is currently ECMAScript 2018.

For more info, visit here

How do I check if the user is pressing a key?

In java you don't check if a key is pressed, instead you listen to KeyEvents. The right way to achieve your goal is to register a KeyEventDispatcher, and implement it to maintain the state of the desired key:

import java.awt.KeyEventDispatcher;
import java.awt.KeyboardFocusManager;
import java.awt.event.KeyEvent;

public class IsKeyPressed {
    private static volatile boolean wPressed = false;
    public static boolean isWPressed() {
        synchronized (IsKeyPressed.class) {
            return wPressed;

    public static void main(String[] args) {
        KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new KeyEventDispatcher() {

            public boolean dispatchKeyEvent(KeyEvent ke) {
                synchronized (IsKeyPressed.class) {
                    switch (ke.getID()) {
                    case KeyEvent.KEY_PRESSED:
                        if (ke.getKeyCode() == KeyEvent.VK_W) {
                            wPressed = true;

                    case KeyEvent.KEY_RELEASED:
                        if (ke.getKeyCode() == KeyEvent.VK_W) {
                            wPressed = false;
                    return false;

Then you can always use:

if (IsKeyPressed.isWPressed()) {
    // do your thing.

You can, of course, use same method to implement isPressing("<some key>") with a map of keys and their state wrapped inside IsKeyPressed.

Writing JSON object to a JSON file with fs.writeFileSync

You need to stringify the object.

fs.writeFileSync('../data/phraseFreqs.json', JSON.stringify(output));

Spark DataFrame TimestampType - how to get Year, Month, Day values from field?

You can use functions in pyspark.sql.functions: functions like year, month, etc

refer to here:

from pyspark.sql.functions import *

newdf ='dt_year'), month('dt_month'), dayofmonth('dt_day'), dayofyear('dt_dayofy'), hour('dt_hour'), minute('dt_min'), weekofyear('dt_week_no'), unix_timestamp('dt_int'))

|dt_year|dt_month|dt_day|dt_dayofy|dt_hour|dt_min|dt_week_no|    dt_int|
|   2015|       9|     6|      249|      0|     0|        36|1441497601|
|   2015|       9|     6|      249|      0|     0|        36|1441497601|
|   2015|       9|     6|      249|      0|     0|        36|1441497603|
|   2015|       9|     6|      249|      0|     1|        36|1441497694|
|   2015|       9|     6|      249|      0|    20|        36|1441498808|
|   2015|       9|     6|      249|      0|    20|        36|1441498811|
|   2015|       9|     6|      249|      0|    20|        36|1441498815|

Android Error - Open Failed ENOENT

Put the text file in the assets directory. If there isnt an assets dir create one in the root of the project. Then you can use Context.getAssets().open("BlockForTest.txt"); to open a stream to this file.

How to escape "&" in XML?

use &amp; in place of &

change to

<string name="magazine">Newspaper &amp; Magazines</string>

How to use operator '-replace' in PowerShell to replace strings of texts with special characters and replace successfully

In your example, you prepended your source string with AccountKey= but not your target string.

$c = $c -replace 'AccountKey=eKkij32jGEIYIEqAR5RjkKgf4OTiMO6SAyF68HsR/Zd/KXoKvSdjlUiiWyVV2+OUFOrVsd7jrzhldJPmfBBpQA==','AccountKey=DdOegAhDmLdsou6Ms6nPtP37bdw6EcXucuT47lf9kfClA6PjGTe3CfN+WVBJNWzqcQpWtZf10tgFhKrnN48lXA=='

By not including that in the target string, the resulting string will remove AccountKey= instead of replacing it. You correctly do this with the AccountName= example, which seems to support this conclusion since it is not giving you any problems. If you really mean to have that prepended, then this may resolve your issue.

Notepad++ Multi editing

Notepad++ also handles multiple cursors now.

Go into Settings => Preferences => Editing and check "Enable" in "Multi editing settings" Then, just use Ctrl+click to use multiple cursors.

Feature demo on official website here :

std::string to char*

A safe version of orlp's char* answer using unique_ptr:

std::string str = "string";
auto cstr = std::make_unique<char[]>(str.length() + 1);
strcpy(cstr.get(), str.c_str());

Create Hyperlink in Slack

you can try quoting it which will keep the link as text. see the code blocks section:

jQuery Validate Plugin - How to create a simple custom rule?

You can add a custom rule like this:

    function (value, element, requiredValue) {
        return value === requiredValue;
    'Please check your input.'

And add it as a rule like this:

PhoneToggle: {
    booleanRequired: 'on'

server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

Or simply run this comment to add the server Certificate to your database:

echo $(echo -n | openssl s_client -showcerts -connect 2>/dev/null  | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p') >> /etc/ssl/certs/ca-certificates.crt

Then do git clone again.

Can Mockito capture arguments of a method called multiple times?

First of all: you should always import mockito static, this way the code will be much more readable (and intuitive) - the code samples below require it to work:

import static org.mockito.Mockito.*;

In the verify() method you can pass the ArgumentCaptor to assure execution in the test and the ArgumentCaptor to evaluate the arguments:

ArgumentCaptor<MyExampleClass> argument = ArgumentCaptor.forClass(MyExampleClass.class);
verify(yourmock, atleast(2)).myMethod(argument.capture());

List<MyExampleClass> passedArguments = argument.getAllValues();

for (MyExampleClass data : passedArguments){
    //assertSometing ...

The list of all passed arguments during your test is accessible via the argument.getAllValues() method.

The single (last called) argument's value is accessible via the argument.getValue() for further manipulation / checking or whatever you wish to do.

SQL Query to add a new column after an existing column in SQL Server 2005

It's possible.

First, just add each column the usual way (as the last column).

Secondly, in SQL Server Management Studio Get into Tools => Options.

Under 'Designers' Tab => 'Table and Database Designers' menu, uncheck the option 'Prevent saving changes that require table re-creation'.

Afterwards, right click on your table and choose 'Design'. In 'Design' mode just drag the columns to order them.

Don't forget to save.

How to use GROUP BY to concatenate strings in SQL Server?

Using Replace Function and FOR JSON PATH


For sample data and more ways click here

Python creating a dictionary of lists

You can use defaultdict:

>>> from collections import defaultdict
>>> d = defaultdict(list)
>>> a = ['1', '2']
>>> for i in a:
...   for j in range(int(i), int(i) + 2):
...     d[j].append(i)
>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (2, ['1', '2']), (3, ['2'])]

Import functions from another js file. Javascript

//In module.js add below code

export function multiply() {
    return 2 * 3;

// Consume the module in calc.js

import { multiply } from './modules.js';

const result = multiply();

console.log(`Result: ${result}`);

// Module.html

<!DOCTYPE html>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">

  <script type="module" src="./calc.js"></script>

Its a design pattern same code can be found below, please use a live server to test it else you will get CORS error

Get query from java.sql.PreparedStatement

A bit of a hack, but it works fine for me:

Integer id = 2;
String query = "SELECT * FROM table WHERE id = ?";
PreparedStatement statement = m_connection.prepareStatement( query );
statement.setObject( 1, value );
String statementText = statement.toString();
query = statementText.substring( statementText.indexOf( ": " ) + 2 );

How to fix a collation conflict in a SQL Server query?

Adding to the accepted answer, you can used DATABASE_DEFAULT as encoding.

This allows database to make choice for you and your code becomes more portable.

    FirstTable a
        INNER JOIN SecondTable b

In what situations would AJAX long/short polling be preferred over HTML5 WebSockets?

For chat applications or any other application that is in constant conversation with the server, WebSockets are the best option. However, you can only use WebSockets with a server that supports them, so that may limit your ability to use them if you cannot install the required libraries. In which case, you would need to use Long Polling to obtain similar functionality.

Renew Provisioning Profile

In Xcode4 go to the Organizer. Choose at library the Provisioning Profiles. Select your provisioning profile and click on the "Refresh" button at the bottom. It will ask you to enter your login and password. After that, the profile is renewed.

What does the variable $this mean in PHP?

Generally, this keyword is used inside a class, generally with in the member functions to access non-static members of a class(variables or functions) for the current object.

  1. this keyword should be preceded with a $ symbol.
  2. In case of this operator, we use the -> symbol.
  3. Whereas, $this will refer the member variables and function for a particular instance.

Let's take an example to understand the usage of $this.

class Hero {
    // first name of hero
    private $name;
    // public function to set value for name (setter method)
    public function setName($name) {
        $this->name = $name;
    // public function to get value of name (getter method)
    public function getName() {
        return $this->name;

// creating class object
$stark = new Hero();

// calling the public function to set fname
$stark->setName("IRON MAN");

// getting the value of the name variable
echo "I Am " . $stark->getName();


NOTE: A static variable acts as a global variable and is shared among all the objects of the class. A non-static variables are specific to instance object in which they are created.

How many concurrent requests does a single Flask process receive?

When running the development server - which is what you get by running, you get a single synchronous process, which means at most 1 request is being processed at a time.

By sticking Gunicorn in front of it in its default configuration and simply increasing the number of --workers, what you get is essentially a number of processes (managed by Gunicorn) that each behave like the development server. 4 workers == 4 concurrent requests. This is because Gunicorn uses its included sync worker type by default.

It is important to note that Gunicorn also includes asynchronous workers, namely eventlet and gevent (and also tornado, but that's best used with the Tornado framework, it seems). By specifying one of these async workers with the --worker-class flag, what you get is Gunicorn managing a number of async processes, each of which managing its own concurrency. These processes don't use threads, but instead coroutines. Basically, within each process, still only 1 thing can be happening at a time (1 thread), but objects can be 'paused' when they are waiting on external processes to finish (think database queries or waiting on network I/O).

This means, if you're using one of Gunicorn's async workers, each worker can handle many more than a single request at a time. Just how many workers is best depends on the nature of your app, its environment, the hardware it runs on, etc. More details can be found on Gunicorn's design page and notes on how gevent works on its intro page.

WPF: simple TextBox data binding

Just for future needs.

In Visual Studio 2013 with .NET Framework 4.5, for a window property, try adding ElementName=window to make it work.

<Grid Name="myGrid" Height="437.274">
  <TextBox Text="{Binding Path=Name2, ElementName=window}"/>

What are the ways to make an html link open a folder

The URL file://[servername]/[sharename] should open an explorer window to the shared folder on the network.

querying WHERE condition to character length?

Sorry, I wasn't sure which SQL platform you're talking about:


$query = ("SELECT * FROM $db WHERE conditions AND LENGTH(col_name) = 3");


$query = ("SELECT * FROM $db WHERE conditions AND LEN(col_name) = 3");

The LENGTH() (MySQL) or LEN() (MSSQL) function will return the length of a string in a column that you can use as a condition in your WHERE clause.


I know this is really old but thought I'd expand my answer because, as Paulo Bueno rightly pointed out, you're most likely wanting the number of characters as opposed to the number of bytes. Thanks Paulo.

So, for MySQL there's the CHAR_LENGTH(). The following example highlights the difference between LENGTH() an CHAR_LENGTH():

    word VARCHAR(100)
) ENGINE INNODB DEFAULT CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci;

INSERT INTO words(word) VALUES('??'), ('happy'), ('hayir');

SELECT word, LENGTH(word) as num_bytes, CHAR_LENGTH(word) AS num_characters FROM words;

| word   | num_bytes | num_characters |
| ??    |         6 |              2 |
| happy  |         5 |              5 |
| hayir  |         6 |              5 |

Be careful if you're dealing with multi-byte characters.

Iterating through map in template

As Herman pointed out, you can get the index and element from each iteration.

{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}

Working example:

package main

import (

type EntetiesClass struct {
    Name string
    Value int32

// In the template, we use rangeStruct to turn our struct values
// into a slice we can iterate over
var htmlTemplate = `{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}

func main() {
    data := map[string][]EntetiesClass{
        "Yoga": {{"Yoga", 15}, {"Yoga", 51}},
        "Pilates": {{"Pilates", 3}, {"Pilates", 6}, {"Pilates", 9}},

    t := template.New("t")
    t, err := t.Parse(htmlTemplate)
    if err != nil {

    err = t.Execute(os.Stdout, data)
    if err != nil {






"Uncaught Error: [$injector:unpr]" with angular after deployment

Add the $http, $scope services in the controller fucntion, sometimes if they are missing these errors occur.

Is it possible to start activity through adb shell?

You can also find the name of the current on screen activity using

adb shell dumpsys window windows | grep 'mCurrentFocus'

Can a Byte[] Array be written to a file in C#?

Yep, why not?

fs.Write(myByteArray, 0, myByteArray.Length);

How to edit default dark theme for Visual Studio Code?


You can get the colors for any theme (including the builtin ones) by switching to the theme then choosing Developer > Generate Color Theme From Current Settings from the command palette.


  1. Switch to the builtin theme you wish to modify by selecting Preferences: Color Theme from the command palette then choosing the theme.

  2. Get the colors for that theme by choosing Developer > Generate Color Theme From Current Settings from the command palette. Save the file with the suffix -color-theme.jsonc.
    The color-theme part will enable color picker widgets when editing the file and jsonc sets the filetype to JSON with comments.

  3. From the command palette choose Preferences: Open Settings (JSON) to open your settings.json file. Then add your desired changes to either the workbench.colorCustomizations or tokenColorCustomizations section.

    • To restrict the settings to just this theme, use an associative arrays where the key is the theme name in brackets ([]) and the value is an associative array of settings.
    • The theme name can be found in settings.json at workbench.colorTheme.

For example, the following customizes the theme listed as Dark+ (default dark) from the Color Theme list. It sets the editor background to near black and the syntax highlighting for comments to a dim gray.

// settings.json
"workbench.colorCustomizations": {
    "[Default Dark+]": {
        "editor.background": "#19191f"
"editor.tokenColorCustomizations": {
    "[Default Dark+]": {
        "comments": "#5F6167"

How to set a value for a span using jQuery

You can do:



$("#submittername").html("testing <b>1 2 3</b>");

"getaddrinfo failed", what does that mean?

Make sure you pass a proxy attribute in your command forexample - pip install --proxy=http://proxyhost:proxyport pixiedust

Use a proxy port which has direct connection (with / without password). Speak with your corporate IT administrator. Quick way is find out network settings used in eclipse which will have direct connection.

You will encouter this issue often if you work behind a corporate firewall. You will have to check your internet explorer - InternetOptions -LAN Connection - Settings

Uncheck - Use automatic configuration script Check - Use a proxy server for your LAN. Ensure you have given the right address and port.

Click Ok Come back to anaconda terminal and you can try install commands

See :hover state in Chrome Developer Tools

In my case, I want to dubug bootstrap tooltip. But the methods above not work for me. I guess bootstrap implemented this by something like mouse in/out event.

Anyway, when I hover on a button, it will generate a brother html element below the button, so I select the button's parent element in "Elements" tab of "Developer tools" window, hover the button, and "Ctrl + C", then I can paste the source code which contains the generated code. Last find the generated code, and add it to the source code by "Edit as HTML" in "Elements" tab.

Hope it can help somebody.

How to check if a service is running via batch file and start it, if it is not running?

@Echo off

Set ServiceName=wampapache64

SC queryex "%ServiceName%"|Find "STATE"|Find /v "RUNNING">Nul&&(

echo %ServiceName% not running

Net start "%ServiceName%"

    SC queryex "%ServiceName%"|Find "STATE"|Find /v "RUNNING">Nul&&(
        Echo "%ServiceName%" wont start
        echo "%ServiceName%" started

    echo "%ServiceName%" was working and stopping

    Net stop "%ServiceName%"



Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

I found a faster way of embedding:

  • Just copy the link.
  • Paste the link and remove the "?s=19" part and add "/video/1"
  • That's it.

Is there a limit on an Excel worksheet's name length?

The file format would permit up to 255-character worksheet names, but if the Excel UI doesn't want you exceeding 31 characters, don't try to go beyond 31. App's full of weird undocumented limits and quirks, and feeding it files that are within spec but not within the range of things the testers would have tested usually causes REALLY strange behavior. (Personal favorite example: using the Excel 4.0 bytecode for an if() function, in a file with an Excel 97-style stringtable, disabled the toolbar button for bold in Excel 97.)

Create an enum with string values

I have tried in TypeScript 1.5 like below and it's worked for me

module App.Constants {
   export enum e{
        Hello= ("Hello") as any,
World= ("World") as any

How do I authenticate a WebClient request?

What kind of authentication are you using? If it's Forms authentication, then at best, you'll have to find the .ASPXAUTH cookie and pass it in the WebClient request.

At worst, it won't work.

How to resolve Error : Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation

You also encounter this if you run an Application on a Scheduled Task in Non-Interactive mode.

As soon as you show a Dialog it throws the error:

Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.

You can see its a MessageBox causing the problem in the stack trace:

at System.Windows.Forms.MessageBox.ShowCore(IWin32Window owner, String text, String caption, MessageBoxButtons buttons, MessageBoxIcon icon,  MessageBoxDefaultButton defaultButton, MessageBoxOptions options, Boolean showHelp)  


If you're running your app on a Scheduled Task send an email instead of showing a Dialog.

Convert date to datetime in Python

You can use the date.timetuple() method and unpack operator *.

args = d.timetuple()[:6]

How do I check if a string is a number (float)?

The input may be as follows:

a="50" b=50 c=50.1 d="50.1"

1-General input:

The input of this function can be everything!

Finds whether the given variable is numeric. Numeric strings consist of optional sign, any number of digits, optional decimal part and optional exponential part. Thus +0123.45e6 is a valid numeric value. Hexadecimal (e.g. 0xf4c3b00c) and binary (e.g. 0b10100111001) notation is not allowed.

is_numeric function

import ast
import numbers              
def is_numeric(obj):
    if isinstance(obj, numbers.Number):
        return True
    elif isinstance(obj, str):
        nodes = list(ast.walk(ast.parse(obj)))[1:]
        if not isinstance(nodes[0], ast.Expr):
            return False
        if not isinstance(nodes[-1], ast.Num):
            return False
        nodes = nodes[1:-1]
        for i in range(len(nodes)):
            #if used + or - in digit :
            if i % 2 == 0:
                if not isinstance(nodes[i], ast.UnaryOp):
                    return False
                if not isinstance(nodes[i], (ast.USub, ast.UAdd)):
                    return False
        return True
        return False


>>> is_numeric("54")
>>> is_numeric("54.545")
>>> is_numeric("0x45")

is_float function

Finds whether the given variable is float. float strings consist of optional sign, any number of digits, ...

import ast

def is_float(obj):
    if isinstance(obj, float):
        return True
    if isinstance(obj, int):
        return False
    elif isinstance(obj, str):
        nodes = list(ast.walk(ast.parse(obj)))[1:]
        if not isinstance(nodes[0], ast.Expr):
            return False
        if not isinstance(nodes[-1], ast.Num):
            return False
        if not isinstance(nodes[-1].n, float):
            return False
        nodes = nodes[1:-1]
        for i in range(len(nodes)):
            if i % 2 == 0:
                if not isinstance(nodes[i], ast.UnaryOp):
                    return False
                if not isinstance(nodes[i], (ast.USub, ast.UAdd)):
                    return False
        return True
        return False


>>> is_float("5.4")
>>> is_float("5")
>>> is_float(5)
>>> is_float("5")
>>> is_float("+5.4")

what is ast?

2- If you are confident that the variable content is String:

use str.isdigit() method

>>> a=454
>>> a.isdigit()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'int' object has no attribute 'isdigit'
>>> a="454"
>>> a.isdigit()

3-Numerical input:

detect int value:

>>> isinstance("54", int)
>>> isinstance(54, int)

detect float:

>>> isinstance("45.1", float)
>>> isinstance(45.1, float)

Why check both isset() and !empty()

isset() tests if a variable is set and not null:

empty() can return true when the variable is set to certain values:

To demonstrate this, try the following code with $the_var unassigned, set to 0, and set to 1.


#$the_var = 0;

if (isset($the_var)) {
  echo "set";
} else {
  echo "not set";

echo "\n";

if (empty($the_var)) {
  echo "empty";
} else {
  echo "not empty";

Insert at first position of a list in Python

Use insert:

In [1]: ls = [1,2,3]

In [2]: ls.insert(0, "new")

In [3]: ls
Out[3]: ['new', 1, 2, 3]

EC2 instance has no public DNS

First of all, there can be two reasons for this:

  1. You have created your own VPC and forgot to enable Public DNS.

To solve this :

i) Go to AWS VPC console and select the VPC you have created.

ii) Then click on Actions and then enable DNS Resolution.

  1. You have not enabled public ip-assign option in EC2 configuration.

Here you cannot change the setting; so create an ami image and then recreate the instance from that.

OSX - How to auto Close Terminal window after the "exit" command executed.

In the Terminal app, Preference >> Profiles tab.

Select the Shell tab on the right. enter image description here

You can choose Never Ask before closing to suppress the warning.

Get event listeners attached to node using addEventListener

Chrome DevTools, Safari Inspector and Firebug support getEventListeners(node).


Check if string contains only letters in javascript

try to add \S at your pattern


how to use free cloud database with android app?

As Wingman said, Google App Engine is a great solution for your scenario.

You can get some information about GAE+Android here:

And from this Google IO 2012 session:

Android Studio: Gradle: error: cannot find symbol variable

Make sure you have MainActivity and .ScanActivity into your AndroidManifest.xml file:

<activity android:name=".MainActivity">
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
    <activity android:name=".ScanActivity">


Reset input value in angular 2

You can use the to reset the input from a component directly. = ""

How to replace plain URLs with links?

I had to do the opposite, and make html links into just the URL, but I modified your regex and it works like a charm, thanks :)

var exp = /<a\s.*href=['"](\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])['"].*>.*<\/a>/ig;

source = source.replace(exp,"$1");

Problem with SMTP authentication in PHP using PHPMailer, with Pear Mail works

Try adding this:

$mail->SMTPAuth   = true;
$mail->SMTPSecure = "tls";

By looking at your debug logs, you can notice that the failing PhpMailer log shows this:

SMTP -> ERROR: AUTH not accepted from server: 250 Hello []
503 AUTH command used when not advertised

While your successful PEAR log shows this:

DEBUG: Recv: 220 TLS go ahead

My guess is that explicitly asking PHPMailer to use TLS will put it on the right track.
Also, make sure you're using the latest versin of PHPMailer.

How can I fix WebStorm warning "Unresolved function or method" for "require" (Firefox Add-on SDK)

Do you mean that require() is not resolved? You need to either add require.js to your project or enable Node.js Globals predefined library in Settings/Languages and Frameworks/JavaScript/Libraries.

(Edited settings path by @yurik)

In WebStorm 2016.x-2017.x: make sure that the Node.js Core library is enabled in Settings (Preferences) | Languages & Frameworks | Node.js and NPM

In IntelliJ 2018.3.2+ go to Settings (Preferences) | Languages & Frameworks | Node.js and NPM and enable Coding assistance for Node.js

Can you Run Xcode in Linux?

It was weird that no one suggested KVM.

It is gonna provide you almost native performance and it is built-in Linux. Go and check it out.

you will feel like u are using mac only and then install Xcode there u may even choose to directly boot into the OSX GUI instead of Linux one on startup

How can prevent a PowerShell window from closing so I can see the error?

You basically have 3 options to prevent the PowerShell Console window from closing, that I describe in more detail on my blog post.

  1. One-time Fix: Run your script from the PowerShell Console, or launch the PowerShell process using the -NoExit switch. e.g. PowerShell -NoExit "C:\SomeFolder\SomeScript.ps1"
  2. Per-script Fix: Add a prompt for input to the end of your script file. e.g. Read-Host -Prompt "Press Enter to exit"
  3. Global Fix: Change your registry key to always leave the PowerShell Console window open after the script finishes running. Here's the 2 registry keys that would need to be changed:

    ? Open With ? Windows PowerShell
    When you right-click a .ps1 file and choose Open With

    Registry Key: HKEY_CLASSES_ROOT\Applications\powershell.exe\shell\open\command

    Default Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "%1"

    Desired Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "& \"%1\""

    ? Run with PowerShell
    When you right-click a .ps1 file and choose Run with PowerShell (shows up depending on which Windows OS and Updates you have installed).

    Registry Key: HKEY_CLASSES_ROOT\Microsoft.PowerShellScript.1\Shell\0\Command

    Default Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "-Command" "if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & '%1'"

    Desired Value:

    "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -NoExit "-Command" "if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & \"%1\""

You can download a .reg file from my blog to modify the registry keys for you if you don't want to do it manually.

It sounds like you likely want to use option #2. You could even wrap your whole script in a try block, and only prompt for input if an error occurred, like so:

    # Do your script's stuff
    Write-Error $_.Exception.ToString()
    Read-Host -Prompt "The above error occurred. Press Enter to exit."

Format date as dd/MM/yyyy using pipes

If anyone can looking to display date with time in AM or PM in angular 6 then this is for you.

{{date | date: 'dd/MM/yyyy hh:mm a'}}


enter image description here

Pre-defined format options

Examples are given in en-US locale.

'short': equivalent to 'M/d/yy, h:mm a' (6/15/15, 9:03 AM).
'medium': equivalent to 'MMM d, y, h:mm:ss a' (Jun 15, 2015, 9:03:01 AM).
'long': equivalent to 'MMMM d, y, h:mm:ss a z' (June 15, 2015 at 9:03:01 AM GMT+1).
'full': equivalent to 'EEEE, MMMM d, y, h:mm:ss a zzzz' (Monday, June 15, 2015 at 9:03:01 AM GMT+01:00).
'shortDate': equivalent to 'M/d/yy' (6/15/15).
'mediumDate': equivalent to 'MMM d, y' (Jun 15, 2015).
'longDate': equivalent to 'MMMM d, y' (June 15, 2015).
'fullDate': equivalent to 'EEEE, MMMM d, y' (Monday, June 15, 2015).
'shortTime': equivalent to 'h:mm a' (9:03 AM).
'mediumTime': equivalent to 'h:mm:ss a' (9:03:01 AM).
'longTime': equivalent to 'h:mm:ss a z' (9:03:01 AM GMT+1).
'fullTime': equivalent to 'h:mm:ss a zzzz' (9:03:01 AM GMT+01:00).

Reference Link

Remove Sub String by using Python

BeautifulSoup(text, features="html.parser").text 

For the people who were seeking deep info in my answer, sorry.

I'll explain it.

Beautifulsoup is a widely use python package that helps the user (developer) to interact with HTML within python.

The above like just take all the HTML text (text) and cast it to Beautifulsoup object - that means behind the sense its parses everything up (Every HTML tag within the given text)

Once done so, we just request all the text from within the HTML object.

How to sort two lists (which reference each other) in the exact same way

an algorithmic solution:

list1 = [3,2,4,1, 1]
list2 = ['three', 'two', 'four', 'one', 'one2']

lis = [(list1[i], list2[i]) for i in range(len(list1))]
list2 = [x[1] for i in range(len(list1)) for x in lis if x[0] == i]

Outputs: -> Output speed: 0.2s

>>>[1, 1, 2, 3, 4]
>>>['one', 'one2', 'two', 'three', 'four']

How to change the hosts file on android

You have root, but you still need to remount /system to be read/write

$ adb shell
$ su
$ mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system

Go here for more information: Mount a filesystem read-write.

What is the best way to test for an empty string in Go?

This seems to be premature microoptimization. The compiler is free to produce the same code for both cases or at least for these two

if len(s) != 0 { ... }


if s != "" { ... }

because the semantics is clearly equal.

Failed to execute 'atob' on 'Window'

In my case, I was going nuts since there wasn't any issues with the string to be decoded, since I could successfully decode it on online tools. Until I found out that you first have to decodeURIComponent what you are decoding, like so:


How to draw text using only OpenGL methods?

This article describes how to render text in OpenGL using various techniques.

With only using opengl, there are several ways:

  • using glBitmap
  • using textures
  • using display lists

How do I read a specified line in a text file?

If the lines are all of a fixed length you can use the Seek method of a stream to move to the correct starting positiion.

If the lines are of a variable length your options are more limited.

If this is a file you will be only using once and then discarding, then you are best off reading it in and working with it in memeory.

If this is a file you will keeping and will be reading from more than writing to, you can create a custom index file that contains the starting positions of each line. Then use that index to get your Seek position. The process of creating the index file is resource intensive. Everytime you add a new line to the file you will need to update the index, so maintenance becomes a non-trivial issue.

How to yum install Node.JS on Amazon Linux

The accepted answer gave me node 0.10.36 and npm 1.3.6 which are very out of date. I grabbed the latest linux-x64 tarball from the nodejs downloads page and it wasn't too difficult to install:

# start in a directory where you like to install things for the current user
(For noobs : it downloads node package as node.tgz file in your directlry)
curl (paste the link to the one you want from the downloads page) >node.tgz

Now upzip the tar you just downloaded -

tar xzf node.tgz

Run this command and then also add it to your .bashrc:

export PATH="$PATH:(your install dir)/(node dir)/bin"

(example : export PATH ="$PATH:/home/ec2-user/mydirectory/node/node4.5.0-linux-x64/bin")

And update npm (only once, don't add to .bashrc):

npm install -g npm

Note that the -g there which means global, really means global to that npm instance which is the instance we just installed and is limited to the current user. This will apply to all packages that npm installs 'globally'.

Can't open file 'svn/repo/db/txn-current-lock': Permission denied

In addition to the repository permissions, the /tmp directory must also be writeable by all users.

Using TortoiseSVN via the command line

My fix for getting SVN commands was to copy .exe and .dll files from the TortoiseSVN directory and pasting them into system32 folder.

You could also perform the command from the TortoiseSVN directory and add the path of the working directory to each command. For example:

C:\Program Files\TortoiseSVN\bin> svn st -v C:\checkout

Adding the bin to the path should make it work without duplicating the files, but it didn't work for me.

Image resizing in React Native

image auto fix the View

image: {
    flex: 1,
    width: null,
    height: null,
    resizeMode: 'contain'

How to add parameters into a WebRequest?

If these are the parameters of url-string then you need to add them through '?' and '&' chars, for example

If these are the parameters of POST request, then you need to create POST data and write it to request stream. Here is sample method:

private static string doRequestWithBytesPostData(string requestUri, string method, byte[] postData,
                                        CookieContainer cookieContainer,
                                        string userAgent, string acceptHeaderString,
                                        string referer,
                                        string contentType, out string responseUri)
            var result = "";
            if (!string.IsNullOrEmpty(requestUri))
                var request = WebRequest.Create(requestUri) as HttpWebRequest;
                if (request != null)
                    request.KeepAlive = true;
                    var cachePolicy = new RequestCachePolicy(RequestCacheLevel.BypassCache);
                    request.CachePolicy = cachePolicy;
                    request.Expect = null;
                    if (!string.IsNullOrEmpty(method))
                        request.Method = method;
                    if (!string.IsNullOrEmpty(acceptHeaderString))
                        request.Accept = acceptHeaderString;
                    if (!string.IsNullOrEmpty(referer))
                        request.Referer = referer;
                    if (!string.IsNullOrEmpty(contentType))
                        request.ContentType = contentType;
                    if (!string.IsNullOrEmpty(userAgent))
                        request.UserAgent = userAgent;
                    if (cookieContainer != null)
                        request.CookieContainer = cookieContainer;

                    request.Timeout = Constants.RequestTimeOut;

                    if (request.Method == "POST")
                        if (postData != null)
                            request.ContentLength = postData.Length;
                            using (var dataStream = request.GetRequestStream())
                                dataStream.Write(postData, 0, postData.Length);

                    using (var httpWebResponse = request.GetResponse() as HttpWebResponse)
                        if (httpWebResponse != null)
                            responseUri = httpWebResponse.ResponseUri.AbsoluteUri;
                            using (var streamReader = new StreamReader(httpWebResponse.GetResponseStream()))
                                result = streamReader.ReadToEnd();
                            return result;
            responseUri = null;
            return null;

Remove last commit from remote git repository

Be careful that this will create an "alternate reality" for people who have already fetch/pulled/cloned from the remote repository. But in fact, it's quite simple:

git reset HEAD^ # remove commit locally
git push origin +HEAD # force-push the new HEAD commit

If you want to still have it in your local repository and only remove it from the remote, then you can use:

git push origin +HEAD^:<name of your branch, most likely 'master'>