Programs & Examples On #Blendability

Easy way to pull latest of all git submodules

As it may happens that the default branch of your submodules is not master, this is how I automate the full Git submodules upgrades:

git submodule init
git submodule update
git submodule foreach 'git fetch origin; git checkout $(git rev-parse --abbrev-ref HEAD); git reset --hard origin/$(git rev-parse --abbrev-ref HEAD); git submodule update --recursive; git clean -dfx'

add title attribute from css

Well, although it's not actually possible to change the title attribute, it is possible to show a tooltip completely from css. You can check a working version out at

What you can do is style the label:after selector and give it display:none, and set it's content from css. You can then change the display attribute to display:block on label:hover:after, and it will show. Like this:

    content: "my tooltip";
    padding: 2px;
    position: relative;
    top: -20px;
    right: -30px;
    width: 150px;
    text-align: center;
    background-color: #fef4c5;
    border: 1px solid #d4b943;
    -moz-border-radius: 2px;
    -webkit-border-radius: 2px;
    -ms-border-radius: 2px;
    border-radius: 2px;
    display: block;

?: operator (the 'Elvis operator') in PHP

See the docs:

Since PHP 5.3, it is possible to leave out the middle part of the ternary operator. Expression expr1 ?: expr3 returns expr1 if expr1 evaluates to TRUE, and expr3 otherwise.

Javascript Array inside Array - how can I call the child array name?

Array is just like any other object. You can give it a name if you want.

var size = new Array("S", "M", "L", "XL", "XXL");
var color = new Array("Red", "Blue", "Green", "White", "Black");
var options = new Array( size, color); = "color"; = "size";
options[0].name == "size"

What does android:layout_weight mean?

If there are multiple views spanning a LinearLayout, then layout_weight gives them each a proportional size. A view with a bigger layout_weight value "weighs" more, so it gets a bigger space.

Here is an image to make things more clear.

enter image description here


The term layout weight is related to the concept of weighted average in math. It is like in a college class where homework is worth 30%, attendance is worth 10%, the midterm is worth 20%, and the final is worth 40%. Your scores for those parts, when weighted together, give you your total grade.

enter image description here

It is the same for layout weight. The Views in a horizontal LinearLayout can each take up a certain percentage of the total width. (Or a percentage of the height for a vertical LinearLayout.)

The Layout

The LinearLayout that you use will look something like this:


    <!-- list of subviews -->


Note that you must use layout_width="match_parent" for the LinearLayout. If you use wrap_content, then it won't work. Also note that layout_weight does not work for the views in RelativeLayouts (see here and here for SO answers dealing with this issue).

The Views

Each view in a horizontal LinearLayout looks something like this:

    android:layout_weight="1" />

Note that you need to use layout_width="0dp" together with layout_weight="1". Forgetting this causes many new users problems. (See this article for different results you can get by not setting the width to 0.) If your views are in a vertical LinearLayout then you would use layout_height="0dp", of course.

In the Button example above I set the weight to 1, but you can use any number. It is only the total that matters. You can see in the three rows of buttons in the first image that I posted, the numbers are all different, but since the proportions are the same, the weighted widths don't change in each row. Some people like to use decimal numbers that have a sum of 1 so that in a complex layout it is clear what the weight of each part is.

One final note. If you have lots of nested layouts that use layout_weight, it can be bad for performance.


Here is the xml layout for the top image:

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

        android:textSize="24sp" />


            android:text="1" />

            android:text="2" />

            android:text="1" />


        android:textSize="24sp" />


            android:text="10" />

            android:text="20" />

            android:text="10" />


        android:textSize="24sp" />


            android:text=".25" />

            android:text=".50" />

            android:text=".25" />



How to get Domain name from URL using jquery..?

While pure JavaScript is sufficient here, I still prefer the jQuery approach. After all, the ask was to get the hostname using jQuery.

var hostName = $(location).attr('hostname');      //

How to run html file using node js

You can use built-in nodejs web server.

Add file server.js for example and put following code:

var http = require('http');
var fs = require('fs');

const PORT=8080; 

fs.readFile('./index.html', function (err, html) {

    if (err) throw err;    

    http.createServer(function(request, response) {  
        response.writeHeader(200, {"Content-Type": "text/html"});  

And after start server from console with command node server.js. Your index.html page will be available on URL http://localhost:8080

error: expected class-name before ‘{’ token

This should be a comment, but comments don't allow multi-line code.

Here's what's happening:

in Event.cpp

#include "Event.h"

preprocessor starts processing Event.h

#ifndef EVENT_H_

it isn't defined yet, so keep going

#define EVENT_H_
#include "common.h"

common.h gets processed ok

#include "Item.h"

Item.h gets processed ok

#include "Flight.h"

Flight.h gets processed ok

#include "Landing.h"

preprocessor starts processing Landing.h

#ifndef LANDING_H_

not defined yet, keep going

#define LANDING_H_

#include "Event.h"

preprocessor starts processing Event.h

#ifndef EVENT_H_

This IS defined already, the whole rest of the file gets skipped. Continuing with Landing.h

class Landing: public Event {

The preprocessor doesn't care about this, but the compiler goes "WTH is Event? I haven't heard about Event yet."

SELECTING with multiple WHERE conditions on same column

You can either use GROUP BY and HAVING COUNT(*) = _:

SELECT contact_id
FROM your_table
WHERE flag IN ('Volunteer', 'Uploaded', ...)
GROUP BY contact_id
HAVING COUNT(*) = 2 -- // must match number in the WHERE flag IN (...) list

(assuming contact_id, flag is unique).

Or use joins:

SELECT T1.contact_id
FROM your_table T1
JOIN your_table T2 ON T1.contact_id = T2.contact_id AND T2.flag = 'Uploaded'
-- // more joins if necessary
WHERE T1.flag = 'Volunteer'

If the list of flags is very long and there are lots of matches the first is probably faster. If the list of flags is short and there are few matches, you will probably find that the second is faster. If performance is a concern try testing both on your data to see which works best.

Programmatically Check an Item in Checkboxlist where text is equal to what I want

All Credit to @Jim Scott -- just added one touch. (ASP.NET 4.5 & C#)

Refractoring this a little more... if you pass the CheckBoxList as an object to the method, you can reuse it for any CheckBoxList. Also you can use either the Text or the Value.

private void SelectCheckBoxList(string valueToSelect, CheckBoxList lst)
    ListItem listItem = lst.Items.FindByValue(valueToSelect);
    //ListItem listItem = lst.Items.FindByText(valueToSelect);
    if (listItem != null) listItem.Selected = true;

//How to call it -- in this case from a SQLDataReader and "chkRP" is my CheckBoxList`

SelectCheckBoxList(dr["kRPId"].ToString(), chkRP);`

How do I access Configuration in any class in ASP.NET Core?

There is also an option to make configuration static in startup.cs so that what you can access it anywhere with ease, static variables are convenient huh!

public Startup(IConfiguration configuration)
    Configuration = configuration;

internal static IConfiguration Configuration { get; private set; }

This makes configuration accessible anywhere using Startup.Configuration.GetSection... What can go wrong?

Draw text in OpenGL ES

If you insist on using GL, you could render the text on to textures. Assuming that most of the HUD is relatively static, you shouldn't have to load the textures to texture memory too often.

Git workflow and rebase vs merge questions

With Git there is no “correct” workflow. Use whatever floats your boat. However, if you constantly get conflicts when merging branches maybe you should coordinate your efforts better with your fellow developer(s)? Sounds like the two of you keep editing the same files. Also, watch out for whitespace and subversion keywords (i.e., “$Id$” and others).

Excluding Maven dependencies

You can utilize the dependency management mechanism.

If you create entries in the <dependencyManagement> section of your pom for spring-security-web and spring-web with the desired 3.1.0 version set the managed version of the artifact will override those specified in the transitive dependency tree.

I'm not sure if that really saves you any code, but it is a cleaner solution IMO.

How to display Base64 images in HTML?

put base64()

<img src="data:image/png;base64,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"></img>

in Javascript

var id=document.getElementById("image");


Command to delete all pods in all kubernetes namespaces

I tried commands from listed answers here but pods were stuck in terminating state.
I found below command to delete all pods from particular namespace if stuck in terminating state or you are not able to delete it then you can delete pods forcefully.

kubectl delete pods --all --grace-period=0 --force --namespace namespace

Hope it might be useful to someone.

jquery dialog save cancel button styling

after looking at some other threads I came up with this solution to add icons to the buttons in a confirm dialog, which seems to work well in version 1.8.1 and can be modified to do other styling:

    buttons: { 
        "Save": function() { ... },                
        "Cancel": function() { ... }

var buttons = $('.ui-dialog-buttonpane').children('button');

$(buttons[0]).append("<span class='ui-icon ui-icon-check'></span>");
$(buttons[1]).append("<span class='ui-icon ui-icon-close'></span>");

I'd be interested in seeing if there was a better way to do it, but this seems pretty efficient.

maxFileSize and acceptFileTypes in blueimp file upload plugin do not work. Why?

open the file named "jquery.fileupload-ui.js", you will see the code like this:

 $.widget('blueimp.fileupload', $.blueimp.fileupload, {

    options: {
        // By default, files added to the widget are uploaded as soon
        // as the user clicks on the start buttons. To enable automatic
        // uploads, set the following option to true:
        acceptFileTypes: /(\.|\/)(gif|jpe?g|png)$/i,
        autoUpload: false,
        // The ID of the upload template:
        uploadTemplateId: 'template-upload',
        // The ID of the download template:
        downloadTemplateId: 'template-download',

just add one line code --- the new attribute "acceptFileTypes",like this:

 options: {
        // By default, files added to the widget are uploaded as soon
        // as the user clicks on the start buttons. To enable automatic
        // uploads, set the following option to true:
        **acceptFileTypes: /(\.|\/)(gif|jpe?g|png)$/i,**
        autoUpload: false,
        // The ID of the upload template:
        uploadTemplateId: 'template-upload',
        // The ID of the download template:
        downloadTemplateId: 'template-d

now you'll see everything is allright!~ you just take the attribute with a wrong place.

Struct memory layout in C

It's implementation-specific, but in practice the rule (in the absence of #pragma pack or the like) is:

  • Struct members are stored in the order they are declared. (This is required by the C99 standard, as mentioned here earlier.)
  • If necessary, padding is added before each struct member, to ensure correct alignment.
  • Each primitive type T requires an alignment of sizeof(T) bytes.

So, given the following struct:

struct ST
   char ch1;
   short s;
   char ch2;
   long long ll;
   int i;
  • ch1 is at offset 0
  • a padding byte is inserted to align...
  • s at offset 2
  • ch2 is at offset 4, immediately after s
  • 3 padding bytes are inserted to align...
  • ll at offset 8
  • i is at offset 16, right after ll
  • 4 padding bytes are added at the end so that the overall struct is a multiple of 8 bytes. I checked this on a 64-bit system: 32-bit systems may allow structs to have 4-byte alignment.

So sizeof(ST) is 24.

It can be reduced to 16 bytes by rearranging the members to avoid padding:

struct ST
   long long ll; // @ 0
   int i;        // @ 8
   short s;      // @ 12
   char ch1;     // @ 14
   char ch2;     // @ 15
} ST;

How To Format A Block of Code Within a Presentation?

Just a few suggestions:

  • Screenshots might be an easy way, but you'll have to make sure the code in the image is big enough and clear enough to read. (not the whole screenshot, just the relevant part)
  • If you can embed html then there are lots of tools to generate syntax highlighted html.

How to convert a string of bytes into an int?

I was struggling to find a solution for arbitrary length byte sequences that would work under Python 2.x. Finally I wrote this one, it's a bit hacky because it performs a string conversion, but it works.

Function for Python 2.x, arbitrary length

def signedbytes(data):
    """Convert a bytearray into an integer, considering the first bit as
    sign. The data must be big-endian."""
    negative = data[0] & 0x80 > 0

    if negative:
        inverted = bytearray(~d % 256 for d in data)
        return -signedbytes(inverted) - 1

    encoded = str(data).encode('hex')
    return int(encoded, 16)

This function has two requirements:

  • The input data needs to be a bytearray. You may call the function like this:

    s = 'y\xcc\xa6\xbb'
    n = signedbytes(s)
  • The data needs to be big-endian. In case you have a little-endian value, you should reverse it first:

    n = signedbytes(s[::-1])

Of course, this should be used only if arbitrary length is needed. Otherwise, stick with more standard ways (e.g. struct).

Codeigniter - no input file specified

My site is hosted on MochaHost, i had a tough time to setup the .htaccess file so that i can remove the index.php from my urls. However, after some googling, i combined the answer on this thread and other answers. My final working .htaccess file has the following contents:

<IfModule mod_rewrite.c>
    # Turn on URL rewriting
    RewriteEngine On

    # If your website begins from a folder e.g localhost/my_project then 
    # you have to change it to: RewriteBase /my_project/
    # If your site begins from the root e.g. example.local/ then
    # let it as it is
    RewriteBase /

    # Protect application and system files from being viewed when the index.php is missing
    RewriteCond $1 ^(application|system|private|logs)

    # Rewrite to index.php/access_denied/URL
    RewriteRule ^(.*)$ index.php/access_denied/$1 [PT,L]

    # Allow these directories and files to be displayed directly:
    RewriteCond $1 ^(index\.php|robots\.txt|favicon\.ico|public|app_upload|assets|css|js|images)

    # No rewriting
    RewriteRule ^(.*)$ - [PT,L]

    # Rewrite to index.php/URL
    RewriteRule ^(.*)$ index.php?/$1 [PT,L]

iPhone keyboard, Done button and resignFirstResponder

From the documentation (any version):

It is your application’s responsibility to dismiss the keyboard at the time of your choosing. You might dismiss the keyboard in response to a specific user action, such as the user tapping a particular button in your user interface. You might also configure your text field delegate to dismiss the keyboard when the user presses the “return” key on the keyboard itself. To dismiss the keyboard, send the resignFirstResponder message to the text field that is currently the first responder. Doing so causes the text field object to end the current editing session (with the delegate object’s consent) and hide the keyboard.

So, you have to send resignFirstResponder somehow. But there is a possibility that textfield loses focus another way during processing of textFieldShouldReturn: message. This also will cause keyboard to disappear.

Is there an equivalent to the SUBSTRING function in MS Access SQL?

I think there is MID() and maybe LEFT() and RIGHT() in Access.

Read file-contents into a string in C++

There should be no \0 in text files.


using namespace std;

int main(){
  fstream f(FILENAME, fstream::in );
  string s;
  getline( f, s, '\0');

  cout << s << endl;

How to sort List<Integer>?

To sort in ascending order :


And for reverse order :


INNER JOIN same table

I think the problem is in your JOIN condition.

SELECT user.user_fname,
FROM users AS user
JOIN users AS parent 
  ON parent.user_id = user.user_parent_id
WHERE user.user_id = $_GET[id]

Edit: You should probably use LEFT JOIN if there are users with no parents.

How to check if an option is selected?

In my case I don't know why selected is always true. So the only way I was able to think up is:

var optionSelected = false;
$( '#select_element option' ).each( function( i, el ) {
    var optionHTMLStr = el.outerHTML;

    if ( optionHTMLStr.indexOf( 'selected' ) > 0 ) {
        optionSelected = true;
        return false;

Delete with "Join" in Oracle sql Query

Based on the answer I linked to in my comment above, this should work:

delete from
select pf.* From PRODUCTFILTERS pf 
And pf.rowid in 
     Select rowid from PRODUCTFILTERS 
     And PRODUCTS.NAME= 'Mark'


delete from PRODUCTFILTERS where rowid in
select pf.rowid From PRODUCTFILTERS pf 
And pf.rowid in 
     And PRODUCTS.NAME= 'Mark'

php create object without class

you can always use new stdClass(). Example code:

   $object = new stdClass();
   $object->property = 'Here we go';


   object(stdClass)#2 (1) {
      string(10) "Here we go"

Also as of PHP 5.4 you can get same output with:

$object = (object) ['property' => 'Here we go'];

NSNotificationCenter addObserver in Swift

We should remove notification also.


  NotificationCenter.default.removeObserver(self, name:NSNotification.Name(rawValue: "notify"), object: nil)


How to loop through file names returned by find?

find . -name "*.txt"|while read fname; do
  echo "$fname"

Note: this method and the (second) method shown by bmargulies are safe to use with white space in the file/folder names.

In order to also have the - somewhat exotic - case of newlines in the file/folder names covered, you will have to resort to the -exec predicate of find like this:

find . -name '*.txt' -exec echo "{}" \;

The {} is the placeholder for the found item and the \; is used to terminate the -exec predicate.

And for the sake of completeness let me add another variant - you gotta love the *nix ways for their versatility:

find . -name '*.txt' -print0|xargs -0 -n 1 echo

This would separate the printed items with a \0 character that isn't allowed in any of the file systems in file or folder names, to my knowledge, and therefore should cover all bases. xargs picks them up one by one then ...

How to manually set an authenticated user in Spring Security / SpringMVC

Ultimately figured out the root of the problem.

When I create the security context manually no session object is created. Only when the request finishes processing does the Spring Security mechanism realize that the session object is null (when it tries to store the security context to the session after the request has been processed).

At the end of the request Spring Security creates a new session object and session ID. However this new session ID never makes it to the browser because it occurs at the end of the request, after the response to the browser has been made. This causes the new session ID (and hence the Security context containing my manually logged on user) to be lost when the next request contains the previous session ID.

PHP: Split string into array, like explode with no delimiter

$array = str_split("$string");

will actuall work pretty fine, BUT if you want to preserve the special characters in that string, and you want to do some manipulation with them, THAN I would use

do {
    $array[] = mb_substr( $string, 0, 1, 'utf-8' );
} while ( $string = mb_substr( $string, 1, mb_strlen( $string ), 'utf-8' ) );

because for some of mine personal uses, it has been shown to be more reliable when there is an issue with special characters

Git - Pushing code to two remotes

To send to both remote with one command, you can create a alias for it:

git config alias.pushall '!git push origin devel && git push github devel'

With this, when you use the command git pushall, it will update both repositories.

Check if Key Exists in NameValueCollection

You could use the Get method and check for null as the method will return null if the NameValueCollection does not contain the specified key.


How can I do time/hours arithmetic in Google Spreadsheet?

I had a similar issue and i just fixed it for now

  1. format each of the cell to time
  2. format the total cell (sum of all the time) to Duration

What event handler to use for ComboBox Item Selected (Selected Item not necessarily changed)

Every ComboBoxItem instance has PreviewMouseDown event. If you will subscribe your custom handler on this event on every ComboBoxItem you will have opportunity to handle every click on the dropdown list.

// Subscribe on ComboBoxItem-s events.
comboBox.Items.Cast<ComboBoxItem>().ToList().ForEach(i => i.PreviewMouseDown += ComboBoxItem_PreviewMouseDown);

private void ComboBoxItem_PreviewMouseDown(object sender, MouseButtonEventArgs e)
     // your handler logic...         

The type initializer for 'CrystalDecisions.CrystalReports.Engine.ReportDocument' threw an exception

I had similar message and after several searches online and doing all suggestions, nothing helped. Finally I found the solution. In my IIS server, under the application pool advance option, there is an option for "Enable 32-Bit Applications" - that was changed from false to true and after restarting IIS server, My program started generating pdf files.

How to extend an existing JavaScript array with another array, without creating a new array

Use Array.extend instead of Array.push for > 150,000 records.

if (!Array.prototype.extend) {
  Array.prototype.extend = function(arr) {
    if (!Array.isArray(arr)) {
      return this;

    for (let record of arr) {

    return this;

How to make jQuery UI nav menu horizontal?

I admire all these efforts to convert a menu to a menubar because I detest trying to hack CSS. It just feels like I'm meddling with powers I can't possibly ever understand! I think it's much easier to add the menubar files available at the menubar branch of jquery ui.

I downloaded the full jquery ui css bundled file from the jquery ui download site

In the head of my document I put the jquery ui css file that contains everything (I'm on version 1.9.x at the moment) followed by the specific CSS file for the menubar widget downloaded from the menubar branch of jquery ui

<link type="text/css" href="css/jquery-ui.css" rel="stylesheet" />
<link type="text/css" href="css/jquery.ui.menubar.css" rel="stylesheet" />

Don't forget the images folder with all the little icons used by jQuery UI needs to be in the same folder as the jquery-ui.css file.

Then at the end the body I have:

<script type="text/javascript" src="js/jquery-1.8.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.9.0.custom.min.js"></script>
<script type="text/javascript" src="js/menubar/jquery.ui.menubar.js"></script>

That's a copy of an up-to-date version of jQuery, followed by a copy of the jQuery UI file, then the menubar module downloaded from the menubar branch of jquery ui

The menubar CSS file is refreshingly short:

.ui-menubar { list-style: none; margin: 0; padding-left: 0; }
.ui-menubar-item { float: left; }
.ui-menubar .ui-button { float: left; font-weight: normal; border-top-width: 0 !important; border-bottom-width: 0 !important; margin: 0; outline: none; }
.ui-menubar .ui-menubar-link { border-right: 1px dashed transparent; border-left: 1px dashed transparent; }
.ui-menubar .ui-menu { width: 200px; position: absolute; z-index: 9999; font-weight: normal; }

but the menubar JavaScript file is 328 lines - too long to quote here. With it, you can simply call menubar() like this example:

    autoExpand: true,
    menuIcon: true,
    buttons: true,
    select: select

As I said, I admire all the attempts to hack the menu object to turn it into a horizontal bar, but I found all of them lacked some standard feature of a horizontal menu bar. I'm not sure why this widget is not bundled with jQuery UI yet, but presumably there are still some bugs to iron out. For instance, I tried it in IE 7 Quirks Mode and the positioning was strange, but it looks great in Firefox, Safari and IE 8+.

Using Spring RestTemplate in generic method with generic parameter

As Sotirios explains, you can not use the ParameterizedTypeReference, but ParameterizedTypeReference is used only to provide Type to the object mapper, and as you have the class that is removed when type erasure happens, you can create your own ParameterizedType and pass that to RestTemplate, so that the object mapper can reconstruct the object you need.

First you need to have the ParameterizedType interface implemented, you can find an implementation in Google Gson project here. Once you add the implementation to your project, you can extend the abstract ParameterizedTypeReference like this:

class FakeParameterizedTypeReference<T> extends ParameterizedTypeReference<T> {

public Type getType() {
    Type [] responseWrapperActualTypes = {MyClass.class};
    ParameterizedType responseWrapperType = new ParameterizedTypeImpl(
    return responseWrapperType;

And then you can pass that to your exchange function:
    new FakeParameterizedTypeReference<ResponseWrapper<T>>());

With all the type information present object mapper will properly construct your ResponseWrapper<MyClass> object

Checking if a file is a directory or just a file

Use the S_ISDIRmacro:

int isDirectory(const char *path) {
   struct stat statbuf;
   if (stat(path, &statbuf) != 0)
       return 0;
   return S_ISDIR(statbuf.st_mode);

Fiddler not capturing traffic from browsers

I've had the same problem. The solution was to remove proxy from Chrome settings. Also you could have an extension that use proxy. Try to disable it.

Executors.newCachedThreadPool() versus Executors.newFixedThreadPool()

If you look at the source code, you will see, they are calling ThreadPoolExecutor. internally and setting their properties. You can create your one to have a better control of your requirement.

public static ExecutorService newFixedThreadPool(int nThreads) {
   return new ThreadPoolExecutor(nThreads, nThreads,0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>());

public static ExecutorService newCachedThreadPool() {
        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                                      60L, TimeUnit.SECONDS,
                                      new SynchronousQueue<Runnable>());

php.ini: which one?

Generally speaking, the cli/php.ini file is used when the PHP binary is called from the command-line.
You can check that running php --ini from the command-line.

fpm/php.ini will be used when PHP is run as FPM -- which is the case with an nginx installation.
And you can check that calling phpinfo() from a php page served by your webserver.

cgi/php.ini, in your situation, will most likely not be used.

Using two distinct php.ini files (one for CLI, and the other one to serve pages from your webserver) is done quite often, and has one main advantages : it allows you to have different configuration values in each case.

Typically, in the php.ini file that's used by the web-server, you'll specify a rather short max_execution_time : web pages should be served fast, and if a page needs more than a few dozen seconds (30 seconds, by default), it's probably because of a bug -- and the page's generation should be stopped.
On the other hand, you can have pretty long scripts launched from your crontab (or by hand), which means the php.ini file that will be used is the one in cli/. For those scripts, you'll specify a much longer max_execution_time in cli/php.ini than you did in fpm/php.ini.

max_execution_time is a common example ; you could do the same with several other configuration directives, of course.

Difference between variable declaration syntaxes in Javascript (including global variables)?

Yes, there are a couple of differences, though in practical terms they're not usually big ones.

There's a fourth way, and as of ES2015 (ES6) there's two more. I've added the fourth way at the end, but inserted the ES2015 ways after #1 (you'll see why), so we have:

var a = 0;     // 1
let a = 0;     // 1.1 (new with ES2015)
const a = 0;   // 1.2 (new with ES2015)
a = 0;         // 2
window.a = 0;  // 3
this.a = 0;    // 4

Those statements explained

#1 var a = 0;

This creates a global variable which is also a property of the global object, which we access as window on browsers (or via this a global scope, in non-strict code). Unlike some other properties, the property cannot be removed via delete.

In specification terms, it creates an identifier binding on the object Environment Record for the global environment. That makes it a property of the global object because the global object is where identifier bindings for the global environment's object Environment Record are held. This is why the property is non-deletable: It's not just a simple property, it's an identifier binding.

The binding (variable) is defined before the first line of code runs (see "When var happens" below).

Note that on IE8 and earlier, the property created on window is not enumerable (doesn't show up in statements). In IE9, Chrome, Firefox, and Opera, it's enumerable.

#1.1 let a = 0;

This creates a global variable which is not a property of the global object. This is a new thing as of ES2015.

In specification terms, it creates an identifier binding on the declarative Environment Record for the global environment rather than the object Environment Record. The global environment is unique in having a split Environment Record, one for all the old stuff that goes on the global object (the object Environment Record) and another for all the new stuff (let, const, and the functions created by class) that don't go on the global object.

The binding is created before any step-by-step code in its enclosing block is executed (in this case, before any global code runs), but it's not accessible in any way until the step-by-step execution reaches the let statement. Once execution reaches the let statement, the variable is accessible. (See "When let and const happen" below.)

#1.2 const a = 0;

Creates a global constant, which is not a property of the global object.

const is exactly like let except that you must provide an initializer (the = value part), and you cannot change the value of the constant once it's created. Under the covers, it's exactly like let but with a flag on the identifier binding saying its value cannot be changed. Using const does three things for you:

  1. Makes it a parse-time error if you try to assign to the constant.
  2. Documents its unchanging nature for other programmers.
  3. Lets the JavaScript engine optimize on the basis that it won't change.

#2 a = 0;

This creates a property on the global object implicitly. As it's a normal property, you can delete it. I'd recommend not doing this, it can be unclear to anyone reading your code later. If you use ES5's strict mode, doing this (assigning to a non-existent variable) is an error. It's one of several reasons to use strict mode.

And interestingly, again on IE8 and earlier, the property created not enumerable (doesn't show up in statements). That's odd, particularly given #3 below.

#3 window.a = 0;

This creates a property on the global object explicitly, using the window global that refers to the global object (on browsers; some non-browser environments have an equivalent global variable, such as global on NodeJS). As it's a normal property, you can delete it.

This property is enumerable, on IE8 and earlier, and on every other browser I've tried.

#4 this.a = 0;

Exactly like #3, except we're referencing the global object through this instead of the global window. This won't work in strict mode, though, because in strict mode global code, this doesn't have a reference to the global object (it has the value undefined instead).

Deleting properties

What do I mean by "deleting" or "removing" a? Exactly that: Removing the property (entirely) via the delete keyword:

window.a = 0;
display("'a' in window? " + ('a' in window)); // displays "true"
delete window.a;
display("'a' in window? " + ('a' in window)); // displays "false"

delete completely removes a property from an object. You can't do that with properties added to window indirectly via var, the delete is either silently ignored or throws an exception (depending on the JavaScript implementation and whether you're in strict mode).

Warning: IE8 again (and presumably earlier, and IE9-IE11 in the broken "compatibility" mode): It won't let you delete properties of the window object, even when you should be allowed to. Worse, it throws an exception when you try (try this experiment in IE8 and in other browsers). So when deleting from the window object, you have to be defensive:

try {
    delete window.prop;
catch (e) {
    window.prop = undefined;

That tries to delete the property, and if an exception is thrown it does the next best thing and sets the property to undefined.

This only applies to the window object, and only (as far as I know) to IE8 and earlier (or IE9-IE11 in the broken "compatibility" mode). Other browsers are fine with deleting window properties, subject to the rules above.

When var happens

The variables defined via the var statement are created before any step-by-step code in the execution context is run, and so the property exists well before the var statement.

This can be confusing, so let's take a look:

display("foo in window? " + ('foo' in window)); // displays "true"
display(" = " +;          // displays "undefined"
display("bar in window? " + ('bar' in window)); // displays "false"
display(" = " +;          // displays "undefined"
var foo = "f";
bar = "b";
display("foo in window? " + ('foo' in window)); // displays "true"
display(" = " +;          // displays "f"
display("bar in window? " + ('bar' in window)); // displays "true"
display(" = " +;          // displays "b"

Live example:

display("foo in window? " + ('foo' in window)); // displays "true"_x000D_
display(" = " +;          // displays "undefined"_x000D_
display("bar in window? " + ('bar' in window)); // displays "false"_x000D_
display(" = " +;          // displays "undefined"_x000D_
var foo = "f";_x000D_
bar = "b";_x000D_
display("foo in window? " + ('foo' in window)); // displays "true"_x000D_
display(" = " +;          // displays "f"_x000D_
display("bar in window? " + ('bar' in window)); // displays "true"_x000D_
display(" = " +;          // displays "b"_x000D_
function display(msg) {_x000D_
  var p = document.createElement('p');_x000D_
  p.innerHTML = msg;_x000D_

As you can see, the symbol foo is defined before the first line, but the symbol bar isn't. Where the var foo = "f"; statement is, there are really two things: defining the symbol, which happens before the first line of code is run; and doing an assignment to that symbol, which happens where the line is in the step-by-step flow. This is known as "var hoisting" because the var foo part is moved ("hoisted") to the top of the scope, but the foo = "f" part is left in its original location. (See Poor misunderstood var on my anemic little blog.)

When let and const happen

let and const are different from var in a couple of ways. The way that's relevant to the question is that although the binding they define is created before any step-by-step code runs, it's not accessible until the let or const statement is reached.

So while this runs:

display(a);    // undefined
var a = 0;
display(a);    // 0

This throws an error:

display(a);    // ReferenceError: a is not defined
let a = 0;

The other two ways that let and const differ from var, which aren't really relevant to the question, are:

  1. var always applies to the entire execution context (throughout global code, or throughout function code in the function where it appears), but let and const apply only within the block where they appear. That is, var has function (or global) scope, but let and const have block scope.

  2. Repeating var a in the same context is harmless, but if you have let a (or const a), having another let a or a const a or a var a is a syntax error.

Here's an example demonstrating that let and const take effect immediately in their block before any code within that block runs, but aren't accessible until the let or const statement:

var a = 0;
if (true)
  console.log(a); // ReferenceError: a is not defined
  let a = 1;

Note that the second console.log fails, instead of accessing the a from outside the block.

Off-topic: Avoid cluttering the global object (window)

The window object gets very, very cluttered with properties. Whenever possible, strongly recommend not adding to the mess. Instead, wrap up your symbols in a little package and export at most one symbol to the window object. (I frequently don't export any symbols to the window object.) You can use a function to contain all of your code in order to contain your symbols, and that function can be anonymous if you like:

(function() {
    var a = 0; // `a` is NOT a property of `window` now

    function foo() {
        alert(a);   // Alerts "0", because `foo` can access `a`

In that example, we define a function and have it executed right away (the () at the end).

A function used in this way is frequently called a scoping function. Functions defined within the scoping function can access variables defined in the scoping function because they're closures over that data (see: Closures are not complicated on my anemic little blog).

jQuery callback for multiple ajax calls

EDIT -- perhaps the best option would be to create a service endpoint that does everything the three requests do. That way you only have to do one request, and all the data is where you need it to be in the response. If you find you are doing the same 3 requests over and over again, you will probably want to go this route. It is often a good design decision to set up a facade service on the server that lumps commonly used smaller server actions together. Just an idea.

one way to do it would be to create a 'sync' object in your click handler before the ajax calls. Something like

var sync = {
   count: 0

The sync will be bound to the scope of the success calls automatically (closure). In the success handler, you increment the count, and if it is 3 you can call the other function.

Alternatively, you could do something like

var sync = {
   success1Complete: false,
   success3Complete: false,

when each success is executed, it would change the value in the sync to true. You would have to check the sync to make sure that all three are true before proceeding.

Note the case where one of your xhrs does not return success -- you need to account for that.

Yet another option would be to always call the final function in your success handlers, and have it access the sync option to determine whether to actually do anything. You would need to make sure the sync is in the scope of that function though.

How do I parse a YAML file in Ruby?

I had the same problem but also wanted to get the content of the file (after the YAML front-matter).

This is the best solution I have found:

if (md = contents.match(/^(?<metadata>---\s*\n.*?\n?)^(---\s*$\n?)/m))
  self.contents = md.post_match
  self.metadata = YAML.load(md[:metadata])

Source and discussion:

Java: JSON -> Protobuf & back conversion

Well, there is no shortcut to do it as per my findings, but somehow you
an achieve it in few simple steps

First you have to declare a bean of type 'ProtobufJsonFormatHttpMessageConverter'

public ProtobufJsonFormatHttpMessageConverter protobufHttpMessageConverter() {  
  return new ProtobufJsonFormatHttpMessageConverter(JsonFormat.parser(), JsonFormat.printer());  

Then you can just write an Utility class like ResponseBuilder, because it can parse the request by default but without these changes it can not produce Json response. and then you can write few methods to convert the response types to its related object type.

public static <T> T build(Message message, Class<T> type) {
  Printer printer = JsonFormat.printer();
  Gson gson = new Gson();
  try {
    return gson.fromJson(printer.print(message), type);
  } catch (JsonSyntaxException | InvalidProtocolBufferException e) {
    throw new ApiException(HttpStatus.INTERNAL_SERVER_ERROR, "Response   conversion Error", e);

Then you can call this method from your controller class as last line like -

return<returned_service_object>, <Type>);

Hope this will help you to implement protobuf in json format.

Trim Whitespaces (New Line and Tab space) in a String in Oracle

Try the code below. It will work if you enter multiple lines in a single column.

create table  products (prod_id number , prod_desc varchar2(50));

insert into products values(1,'test first

test second

test third');

select replace(replace(prod_desc,chr(10),' '),chr(13),' ') from products  where prod_id=2; 

Output :test first test second test third

How do I raise an exception in Rails so it behaves like other Rails exceptions?

If you need an easier way to do it, and don't want much fuss, a simple execution could be:

raise'something bad happened!')

This will raise an exception, say e with e.message = something bad happened!

and then you can rescue it as you are rescuing all other exceptions in general.

Zipping a file in bash fails

Run dos2unix or similar utility on it to remove the carriage returns (^M).

This message indicates that your file has dos-style lineendings:

-bash: /backup/ /bin/bash^M: bad interpreter: No such file or directory 

Utilities like dos2unix will fix it:

 dos2unix <backup.bash > 

Or, if no such utility is installed, you can accomplish the same thing with translate:

tr -d "\015\032" <backup.bash > 

As for how those characters got there in the first place, @MadPhysicist had some good comments.

Can't ping a local VM from the host

Try dropping all the firewall, the one from your VM and the one from you Laptop, or add the rule in your firewall where you can ping

Automate scp file transfer using a shell script

you could also use rsync. It seems to work better for multiple files than scp IMHO.

rsync -avzh /path/to/dir/ user@remote:/path/to/remote/dir/


You can use rsync via ssh by adding the '-e' switch:

rsync -avzh -e ssh /path/do/dir/ user@remote:/path/to/remote/dir/

Fastest JavaScript summation

one of the simplest, fastest, more reusable and flexible is:

Array.prototype.sum = function () {
    for(var total = 0,l=this.length;l--;total+=this[l]); return total;

// usage
var array = [1,2,3,4,5,6,7,8,9,10];

Call Stored Procedure within Create Trigger in SQL Server

The following should do the trick - Only SqlServer

Alter TRIGGER Catagory_Master_Date_update ON Catagory_Master AFTER delete,Update


Declare @id int
DECLARE @cDate as DateTime
    set @cDate =(select Getdate())

select @id=deleted.Catagory_id from deleted
print @cDate

execute dbo.psp_Update_Category @id


Alter PROCEDURE dbo.psp_Update_Category
@id int

DECLARE @cDate as DateTime
    set @cDate =(select Getdate())
    --Update Catagory_Master Set Modify_date=''+@cDate+'' Where Catagory_ID=@id   --@UserID
    Insert into Catagory_Master (Catagory_id,Catagory_Name) values(12,'Testing11')

Comprehensive beginner's virtualenv tutorial?

Virtualenv is a tool to create isolated Python environments.

Let's say you're working in 2 different projects, A and B. Project A is a web project and the team is using the following packages:

  • Python 2.8.x
  • Django 1.6.x

The project B is also a web project but your team is using:

  • Python 2.7.x
  • Django 1.4.x

The machine that you're working doesn't have any version of django, what should you do? Install django 1.4? django 1.6? If you install django 1.4 globally would be easy to point to django 1.6 to work in project A?

Virtualenv is your solution! You can create 2 different virtualenv's, one for project A and another for project B. Now, when you need to work in project A, just activate the virtualenv for project A, and vice-versa.

A better tip when using virtualenv is to install virtualenvwrapper to manage all the virtualenv's that you have, easily. It's a wrapper for creating, working, removing virtualenv's.

How to set standard encoding in Visual Studio

I don't know of a global setting nither but you can try this:

  1. Save all Visual Studio templates in UTF-8
  2. Write a Visual Studio Macro/Addin that will listen to the DocumentSaved event and will save the file in UTF-8 format (if not already).
  3. Put a proxy on your source control that will make sure that new files are always UTF-8.

How to handle notification when app in background in Firebase

The easy way to send messages even if the app is in background and foreground as follow:- To send a message using API, you can use a tool called AdvancedREST Client, its a chrome extension, and send a message with the following parameters.

Rest client tool Link:

use this url:- Content-Type:application/json Authorization:key=Your Server key From or Authoization key(see below ref)

{ "data": {
    "image": "",
    "message": "Firebase Push Message Using API"
    "AnotherActivity": "True"
  "to" : "device id Or Device token"

Authorization key can be obtained by visiting Google developers console and click on Credentials button on the left menu for your project. Among the API keys listed, the server key will be your authorization key.

And you need to put tokenID of the receiver in the “to” section of your POST request sent using API.

Calculating Covariance with Python and Numpy

Thanks to unutbu for the explanation. By default numpy.cov calculates the sample covariance. To obtain the population covariance you can specify normalisation by the total N samples like this:

Covariance = numpy.cov(a, b, bias=True)[0][1]

or like this:

Covariance = numpy.cov(a, b, ddof=0)[0][1]

How can I use a local image as the base image with a dockerfile?

Remember to put not only the tag but also the repository in which that tag is, this way:

docker images
REPOSITORY                                TAG                       IMAGE ID            CREATED             SIZE
elixir                                    1.7-centos7_3             e15e6bf57262        20 hours ago        925MB

You should reference it this way:


Query to display all tablespaces in a database and datafiles

Neither databases, nor tablespaces nor data files belong to any user. Are you coming to this from an MS SQL background?

select tablespace_name, 
from dba_tablespaces
order by tablespace_name, 

Regular expressions inside SQL Server

stored value in DB is: 5XXXXXX [where x can be any digit]

You don't mention data types - if numeric, you'll likely have to use CAST/CONVERT to change the data type to [n]varchar.


WHERE CHARINDEX(column, '5') = 1
  AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
  AND ISNUMERIC(column) = 1


i have also different cases like XXXX7XX for example, so it has to be generic.


WHERE PATINDEX('%7%', column) = 5
  AND CHARINDEX(column, '.') = 0 --to stop decimals if needed
  AND ISNUMERIC(column) = 1


Regex Support

SQL Server 2000+ supports regex, but the catch is you have to create the UDF function in CLR before you have the ability. There are numerous articles providing example code if you google them. Once you have that in place, you can use:

  • 5\d{6} for your first example
  • \d{4}7\d{2} for your second example

For more info on regular expressions, I highly recommend this website.

AngularJS: How to set a variable inside of a template?

Use ngInit:

<div ng-repeat="day in forecast_days" ng-init="f = forecast[day.iso]">
  {{$index}} - {{day.iso}} - {{}}
  Temperature: {{f.temperature}}<br>
  Humidity: {{f.humidity}}<br>


Reading images in python

I read all answers but I think one of the best method is using openCV library.

import cv2

img = cv2.imread('your_image.png',0)

and for displaying the image, use the following code :

from matplotlib import pyplot as plt
plt.imshow(img, cmap = 'gray', interpolation = 'bicubic')
plt.xticks([]), plt.yticks([])  # to hide tick values on X and Y axis

Load local images in React.js

If you want load image with a local relative URL as you are doing. React project has a default public folder. You should put your images folder inside. It will work.

enter image description here

Updating the value of data attribute using jQuery

$('.toggle img').each(function(index) { 
    if($(this).attr('data-id') == '4')
        $(this).attr('data-block', 'something');
        $(this).attr('src', 'something.jpg');


$('.toggle img[data-id="4"]').attr('data-block', 'something');
$('.toggle img[data-id="4"]').attr('src', 'something.jpg');

Retrofit 2.0 how to get deserialised error response.body

I was facing same issue. I solved it with retrofit. Let me show this...

If your error JSON structure are like

"error": {
    "status": "The email field is required."


public class ErrorResponse {

   private ErrorStatus error;

   public ErrorStatus getError() {
      return error;

   public void setError(ErrorStatus error) {
      this.error = error;

And this my Error status class

public class ErrorStatus {

  private String status;

  public String getStatus() {
      return status;

  public void setStatus(String status) {
      this.status = status;

Now we need a class which can handle our json.

  public class ErrorUtils {

   public static ErrorResponse parseError (Response<?> response){
      Converter<ResponseBody , ErrorResponse> converter =          ApiClient.getClient().responseBodyConverter(ErrorResponse.class , new Annotation[0]);
    ErrorResponse errorResponse;
        errorResponse = converter.convert(response.errorBody());
    }catch (IOException e){
        return new ErrorResponse();
    return errorResponse;

Now we can check our response in retrofit api call

private void registrationRequest(String name , String email , String password , String c_password){

    final Call<RegistrationResponce> registrationResponceCall = apiInterface.getRegistration(name , email , password , c_password);
    registrationResponceCall.enqueue(new Callback<RegistrationResponce>() {
        public void onResponse(Call<RegistrationResponce> call, Response<RegistrationResponce> response) {

            if (response.code() == 200){

            }else if (response.code() == 401){

                ErrorResponse errorResponse = ErrorUtils.parseError(response);
                Toast.makeText(MainActivity.this, ""+errorResponse.getError().getStatus(), Toast.LENGTH_SHORT).show();

        public void onFailure(Call<RegistrationResponce> call, Throwable t) {


That's it now you can show your Toast

Difference between Ctrl+Shift+F and Ctrl+I in Eclipse

Ctrl+Shift+F formats the selected line(s) or the whole source code if you haven't selected any line(s) as per the formatter specified in your Eclipse, while Ctrl+I gives proper indent to the selected line(s) or the current line if you haven't selected any line(s).

How can I use custom fonts on a website?

First, you gotta put your font as either a .otf or .ttf somewhere on your server.

Then use CSS to declare the new font family like this:

@font-face {
    font-family: MyFont;
    src: url('pathway/myfont.otf'); 

If you link your document to the CSS file that you declared your font family in, you can use that font just like any other font.

How can we print line numbers to the log in java

Look at this link. In that method you can jump to your line code, when you double click on LogCat's row.

Also you can use this code to get line number:

public static int getLineNumber()
    int lineNumber = 0;
    StackTraceElement[] stackTraceElement = Thread.currentThread()
    int currentIndex = -1;
    for (int i = 0; i < stackTraceElement.length; i++) {
        if (stackTraceElement[i].getMethodName().compareTo("getLineNumber") == 0)
            currentIndex = i + 1;

    lineNumber = stackTraceElement[currentIndex].getLineNumber();

    return lineNumber;

How to force DNS refresh for a website?

As far as I know, a forced update like this is not directly possible. You might be able to reduce the DNS downtime by reducing the TTL (Time-To-Live) value of the entries before changing them, if your name server service provider allows that.

Here's a guide for less painful DNS changes.

A fair warning, though - not all name servers between your client and the authoritative (origin) name server will enforce your TTL, they might have their own caching time.

Turning a Comma Separated string into individual rows

As of Feb 2016 - see the TALLY Table Example - very likely to outperform my TVF below, from Feb 2014. Keeping original post below for posterity:

Too much repeated code for my liking in the above examples. And I dislike the performance of CTEs and XML. Also, an explicit Id so that consumers that are order specific can specify an ORDER BY clause.

    @Line nvarchar(MAX),
    @SplitOn nvarchar(5) = ','
RETURNS @RtnValue table
    Data nvarchar(100) NOT NULL

    DECLARE @split_on_len INT = LEN(@SplitOn)
    DECLARE @start_at INT = 1
    DECLARE @end_at INT
    DECLARE @data_len INT

    WHILE 1=1
        SET @end_at = CHARINDEX(@SplitOn,@Line,@start_at)
        SET @data_len = CASE @end_at WHEN 0 THEN LEN(@Line) ELSE @end_at-@start_at END
        INSERT INTO @RtnValue (data) VALUES( SUBSTRING(@Line,@start_at,@data_len) );
        IF @end_at = 0 BREAK;
        SET @start_at = @end_at + @split_on_len


How to make a stable two column layout in HTML/CSS

Here you go:

    #left {_x000D_
      width: 200px;_x000D_
      float: left;_x000D_
    #right {_x000D_
      margin-left: 200px;_x000D_
      /* Change this to whatever the width of your left column is*/_x000D_
    .clear {_x000D_
      clear: both;_x000D_
  <div id="container">_x000D_
    <div id="left">_x000D_
    <div id="right">_x000D_
      <div style="background-color: red; height: 10px;">Hello</div>_x000D_
    <div class="clear"></div>_x000D_

See it in action here:

In Visual Studio C++, what are the memory allocation representations?

Regarding 0xCC and 0xCD in particular, these are relics from the Intel 8088/8086 processor instruction set back in the 1980s. 0xCC is a special case of the software interrupt opcode INT 0xCD. The special single-byte version 0xCC allows a program to generate interrupt 3.

Although software interrupt numbers are, in principle, arbitrary, INT 3 was traditionally used for the debugger break or breakpoint function, a convention which remains to this day. Whenever a debugger is launched, it installs an interrupt handler for INT 3 such that when that opcode is executed the debugger will be triggered. Typically it will pause the currently running programming and show an interactive prompt.

Normally, the x86 INT opcode is two bytes: 0xCD followed by the desired interrupt number from 0-255. Now although you could issue 0xCD 0x03 for INT 3, Intel decided to add a special version--0xCC with no additional byte--because an opcode must be only one byte in order to function as a reliable 'fill byte' for unused memory.

The point here is to allow for graceful recovery if the processor mistakenly jumps into memory that does not contain any intended instructions. Multi-byte instructions aren't suited this purpose since an erroneous jump could land at any possible byte offset where it would have to continue with a properly formed instruction stream.

Obviously, one-byte opcodes work trivially for this, but there can also be quirky exceptions: for example, considering the fill sequence 0xCDCDCDCD (also mentioned on this page), we can see that it's fairly reliable since no matter where the instruction pointer lands (except perhaps the last filled byte), the CPU can resume executing a valid two-byte x86 instruction CD CD, in this case for generating software interrupt 205 (0xCD).

Weirder still, whereas CD CC CD CC is 100% interpretable--giving either INT 3 or INT 204--the sequence CC CD CC CD is less reliable, only 75% as shown, but generally 99.99% when repeated as an int-sized memory filler.

page from contemporaneous 8088/8086 instruction set manual showing INT instruction
Macro Assembler Reference, 1987

What is the list of valid @SuppressWarnings warning names in Java?

If you're using SonarLint, try above the method or class the whole squid string: @SuppressWarnings("squid:S1172")

Fit cell width to content

Simple :

    <div style='overflow-x:scroll;overflow-y:scroll;width:100%;height:100%'>

Remove specific commit

The algorithm that Git uses when calculating diff's to be reverted requires that

  1. the lines being reverted are not modified by any later commits.
  2. that there not be any other "adjacent" commits later in the history.

The definition of "adjacent" is based on the default number of lines from a context diff, which is 3. So if 'myfile' was constructed like this:

$ cat >myfile <<EOF
line 1
line 2
line 3
$ git add myfile
$ git commit -m "initial check-in"
 1 files changed, 11 insertions(+), 0 deletions(-)
 create mode 100644 myfile

$ perl -p -i -e 's/line 2/this is the second line/;' myfile
$ git commit -am "changed line 2 to second line"
[master d6cbb19] changed line 2
 1 files changed, 1 insertions(+), 1 deletions(-)

$ perl -p -i -e 's/line 3/this is the third line/;' myfile
$ git commit -am "changed line 3 to third line"
[master dd054fe] changed line 3
 1 files changed, 1 insertions(+), 1 deletions(-)

$ git revert d6cbb19
Finished one revert.
[master 2db5c47] Revert "changed line 2"
 1 files changed, 1 insertions(+), 1 deletions(-)

Then it all works as expected.

The second answer was very interesting. There is a feature which has not yet been officially released (though it is available in Git v1.7.2-rc2) called Revert Strategy. You can invoke git like this:

git revert --strategy resolve <commit>

and it should do a better job figuring out what you meant. I do not know what the list of available strategies is, nor do I know the definition of any strategy.

Freeze screen in chrome debugger / DevTools panel for popover inspection?

I found that this works really well in Chrome.

Right click on the element that you'd like to inspect, then click Force Element State > Hover. Screenshot attached.

Force element state

How to display list items as columns?


#cols {
    -moz-column-count: 3;
    -moz-column-gap: 20px;
    -webkit-column-count: 3;
    -webkit-column-gap: 20px;
    column-count: 3;
    column-gap: 20px;


<div id="cols">
    <li>List item 1</li>
    <li>List item 2</li>
    <li>List item 3</li>
    <li>List item 4</li>
    <li>List item 5</li>
    <li>List item 6</li>
    <li>List item 7</li>
    <li>List item 8</li>
    <li>List item 9</li>
    <li>List item 10</li>
    <li>List item 11</li>
    <li>List item 12</li>
    <li>List item 10</li>
    <li>List item 11</li>
    <li>List item 12</li>

Check demo :

Best way to convert pdf files to tiff files

using python this is what I ended up with

    import os
    os.popen(' '.join([
                       self._ghostscriptPath + 'gswin32c.exe', 
                       '-sOutputFile=%s %s' % (tifDest, pdfSource),

error: invalid initialization of non-const reference of type ‘int&’ from an rvalue of type ‘int’

Non-const and const reference binding follow different rules

These are the rules of the C++ language:

  • an expression consisting of a literal number (12) is a "rvalue"
  • it is not permitted to create a non-const reference with a rvalue: int &ri = 12; is ill-formed
  • it is permitted to create a const reference with a rvalue: in this case, an unnamed object is created by the compiler; this object will persist as long as the reference itself exist.

You have to understand that these are C++ rules. They just are.

It is easy to invent a different language, say C++', with slightly different rules. In C++', it would be permitted to create a non-const reference with a rvalue. There is nothing inconsistent or impossible here.

But it would allow some risky code where the programmer might not get what he intended, and C++ designers rightly decided to avoid that risk.

Is there a way to call a stored procedure with Dapper?

With multiple return and multi parameter

string ConnectionString = CommonFunctions.GetConnectionString();
using (IDbConnection conn = new SqlConnection(ConnectionString))
    IEnumerable<dynamic> results = conn.Query(sql: "ProductSearch", 
        param: new { CategoryID = 1, SubCategoryID="", PageNumber=1 }, 
        commandType: CommandType.StoredProcedure);.  // single result

    var reader = conn.QueryMultiple("ProductSearch", 
        param: new { CategoryID = 1, SubCategoryID = "", PageNumber = 1 }, 
        commandType: CommandType.StoredProcedure); // multiple result

    var userdetails = reader.Read<dynamic>().ToList(); // instead of dynamic, you can use your objects
    var salarydetails = reader.Read<dynamic>().ToList();

public static string GetConnectionString()
    // Put the name the Sqlconnection from WebConfig..
    return ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;

String concatenation with Groovy

Reproducing tim_yates answer on current hardware and adding leftShift() and concat() method to check the finding:

  'String leftShift' {
    foo << bar << baz
  'String concat' {

The outcome shows concat() to be the faster solution for a pure String, but if you can handle GString somewhere else, GString template is still ahead, while honorable mention should go to leftShift() (bitwise operator) and StringBuffer() with initial allocation:

* Groovy: 2.4.8
* JVM: OpenJDK 64-Bit Server VM (25.191-b12, Oracle Corporation)
    * JRE: 1.8.0_191
    * Total Memory: 238 MB
    * Maximum Memory: 3504 MB
* OS: Linux (4.19.13-300.fc29.x86_64, amd64)

* Warm Up: Auto (- 60 sec)
* CPU Time Measurement: On

                                    user  system  cpu  real

String adder                         453       7  460   469
String leftShift                     287       2  289   295
String concat                        169       1  170   173
GString template                      24       0   24    24
Readable GString template             32       0   32    32
GString template toString            400       0  400   406
Readable GString template toString   412       0  412   419
StringBuilder                        325       3  328   334
StringBuffer                         390       1  391   398
StringBuffer with Allocation         259       1  260   265

How can I calculate the time between 2 Dates in typescript

It doesn't work because Date - Date relies on exactly the kind of type coercion TypeScript is designed to prevent.

There is a workaround this using the + prefix:

var t = - +(new Date("2013-02-20T12:01:04.753Z");

Or, if you prefer not to use

var t = +(new Date()) - +(new Date("2013-02-20T12:01:04.753Z"));

See discussion here.

Or see Siddharth Singh's answer, below, for a more elegant solution using valueOf()

How to get the Google Map based on Latitude on Longitude?

    function initMap() {
        //echo hiii;

        var map = new google.maps.Map(document.getElementById('map'), {
          center: new google.maps.LatLng(8.5241, 76.9366),
          zoom: 12
        var infoWindow = new google.maps.InfoWindow;

        // Change this depending on the name of your PHP or XML file
        downloadUrl('', function(data) {
            var xml = data.responseXML;
            var markers = xml.documentElement.getElementsByTagName('package');
  , function(markerElem) {
                var id = markerElem.getAttribute('id');
                // var name = markerElem.getAttribute('name');
                // var address = markerElem.getAttribute('address');
                // var type = markerElem.getAttribute('type');
                // var latitude = results[0];
                // var longitude = results[0].geometry.location.lng();
                var point = new google.maps.LatLng(

                var infowincontent = document.createElement('div');
                var strong = document.createElement('strong');
                strong.textContent = name

                var text = document.createElement('text');
                text.textContent = address
                var icon = customLabel[type] || {};
                var package = new google.maps.Marker({
                    map: map,
                    position: point,
                    label: icon.label

                package.addListener('click', function() {
          , package);

    function downloadUrl(url, callback) {
        var request = window.ActiveXObject ?
            new ActiveXObject('Microsoft.XMLHTTP') :
            new XMLHttpRequest;

        request.onreadystatechange = function() {
            if (request.readyState == 4) {
                request.onreadystatechange = doNothing;
                callback(request, request.status);
        };'GET', url, true);

how to change the default positioning of modal in bootstrap?

If you need to change the bottom position of the modal, you need to modify the max-height of the modal-body:

.modal-body {
  max-height: 75vh;

As other answers have said, you can adjust the right and top on the modal-dialog :

.modal-dialog {
  top: 10vh;
  right: 5vw;
  • "vh" means "% of view height"
  • "vw" means "% of view width"

Jquery Date picker Default Date

Are u using this datepicker ? if yes there are options to set the default Date.If you didn't change anything , by default it will show the current date.

any way this will gives current date

$( ".selector" ).datepicker({ defaultDate: new Date() });

How do I make a simple crawler in PHP?

I came up with the following spider code. I adapted it a bit from the following: PHP - Is the there a safe way to perform deep recursion? it seems fairly rapid....

function  spider( $base_url , $search_urls=array() ) {
    $queue[] = $base_url;
    $done           =   array();
    $found_urls     =   array();
    while($queue) {
            $link = array_shift($queue);
            if(!is_array($link)) {
                $done[] = $link;
                foreach( $search_urls as $s) { if (strstr( $link , $s )) { $found_urls[] = $link; } }
                if( empty($search_urls)) { $found_urls[] = $link; }
                if(!empty($link )) {
echo 'LINK:::'.$link;
                      $content =    file_get_contents( $link );
//echo 'P:::'.$content;
                    preg_match_all('~<a.*?href="(.*?)".*?>~', $content, $sublink);
                    if (!in_array($sublink , $done) && !in_array($sublink , $queue)  ) {
                           $queue[] = $sublink;
            } else {
                    $return = array();
                    // flatten multi dimensional array of URLs to one dimensional.
                    while(count($link)) {
                         $value = array_shift($link);
                             foreach($value as $sub)
                                $link[] = $sub;
                               $return[] = $value;
                     // now loop over one dimensional array.
                     foreach($return as $link) {
                                // echo 'L::'.$link;
                                // url may be in form <a href.. so extract what's in the href bit.
                                preg_match_all('/<a[^>]+href=([\'"])(?<href>.+?)\1[^>]*>/i', $link, $result);
                                if ( isset( $result['href'][0] )) { $link = $result['href'][0]; }
                                // add the new URL to the queue.
                                if( (!strstr( $link , "http")) && (!in_array($base_url.$link , $done)) && (!in_array($base_url.$link , $queue)) ) {
                                } else {
                                    if ( (strstr( $link , $base_url  ))  && (!in_array($base_url.$link , $done)) && (!in_array($base_url.$link , $queue)) ) {
                                         $queue[] = $link;

    return $found_urls;

    $base_url       =   '';
    $search_urls    =   array(  $base_url.'acatalog/' );
    $done = spider( $base_url  , $search_urls  );

    // RESULT
    echo '<br /><br />';
    echo 'RESULT:::';
    foreach(  $done as $r )  {
        echo 'URL:::'.$r.'<br />';

JQuery: dynamic height() with window resize()

Okay, how about a CSS answer! We use display: table. Then each of the divs are rows, and finally we apply height of 100% to middle 'row' and voilà.

body { display: table; }
div { display: table-row; }
#content {
    margin:0 auto;
    text-align: center;
    background-color: blue;
    color: white;
    height: 100%;

Convert object to JSON string in C#

Use .net inbuilt class JavaScriptSerializer

  JavaScriptSerializer js = new JavaScriptSerializer();
  string json = js.Serialize(obj);

on change event for file input element

Give unique class and different id for file input

                  var id=$(this).attr('id');
                      $("#"+id).trigger(your function); 
               //for name of file input  $("#"+id).attr("name");

Get current time in milliseconds in Python?

If you're concerned about measuring elapsed time, you should use the monotonic clock (python 3). This clock is not affected by system clock updates like you would see if an NTP query adjusted your system time, for example.

>>> import time
>>> millis = round(time.monotonic() * 1000)

It provides a reference time in seconds that can be used to compare later to measure elapsed time.

How to get table cells evenly spaced?

I'm also open to suggestion on how to tidy this up, if there are any? :-)

Well, you could not use the span element, for semantic reasons. And you don't have to define the class PerformanceCell. The cells and rows can be accessed by using PerformanceTable tr {} and PerformanceTable tr {}, respectively.

For the spacing part, I have got the same problem several times. I shamefully admit I avoided the problem, so I am very curious to any answers too.

mappedBy reference an unknown target entity property

public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    @Column(name = "USER_ID")
    Long userId;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "sender", cascade = CascadeType.ALL)
    List<Notification> sender;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "receiver", cascade = CascadeType.ALL)
    List<Notification> receiver;

public class Notification implements Serializable {

    private static final long serialVersionUID = 1L;


    @Column(name = "NOTIFICATION_ID")
    Long notificationId;

    @Column(name = "TEXT")
    String text;

    @Column(name = "ALERT_STATUS")
    AlertStatus alertStatus = AlertStatus.NEW;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "SENDER_ID")
    User sender;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "RECEIVER_ID")
    User receiver;

What I understood from the answer. mappedy="sender" value should be the same in the notification model. I will give you an example..

User model:

@OneToMany(fetch = FetchType.LAZY, mappedBy = "**sender**", cascade = CascadeType.ALL)
    List<Notification> sender;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "**receiver**", cascade = CascadeType.ALL)
    List<Notification> receiver;

Notification model:

@OneToMany(fetch = FetchType.LAZY, mappedBy = "sender", cascade = CascadeType.ALL)
    List<Notification> **sender**;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "receiver", cascade = CascadeType.ALL)
    List<Notification> **receiver**;

I gave bold font to user model and notification field. User model mappedBy="sender " should be equal to notification List sender; and mappedBy="receiver" should be equal to notification List receiver; If not, you will get error.

How to access /storage/emulated/0/

In Emulator, to view this file click on Settings>Storage>Other>Android>data>com.companyname.textapp>file>Download. Here, textapp is the name of the app you are working on.

Breadth First Vs Depth First

These two terms differentiate between two different ways of walking a tree.

It is probably easiest just to exhibit the difference. Consider the tree:

   / \
  B   C
 /   / \
D   E   F

A depth first traversal would visit the nodes in this order

A, B, D, C, E, F

Notice that you go all the way down one leg before moving on.

A breadth first traversal would visit the node in this order

A, B, C, D, E, F

Here we work all the way across each level before going down.

(Note that there is some ambiguity in the traversal orders, and I've cheated to maintain the "reading" order at each level of the tree. In either case I could get to B before or after C, and likewise I could get to E before or after F. This may or may not matter, depends on you application...)

Both kinds of traversal can be achieved with the pseudocode:

Store the root node in Container
While (there are nodes in Container)
   N = Get the "next" node from Container
   Store all the children of N in Container
   Do some work on N

The difference between the two traversal orders lies in the choice of Container.

  • For depth first use a stack. (The recursive implementation uses the call-stack...)
  • For breadth-first use a queue.

The recursive implementation looks like

   Work on the payload Node
   Foreach child of Node
   /* Alternate time to work on the payload Node (see below) */

The recursion ends when you reach a node that has no children, so it is guaranteed to end for finite, acyclic graphs.

At this point, I've still cheated a little. With a little cleverness you can also work-on the nodes in this order:

D, B, E, F, C, A

which is a variation of depth-first, where I don't do the work at each node until I'm walking back up the tree. I have however visited the higher nodes on the way down to find their children.

This traversal is fairly natural in the recursive implementation (use the "Alternate time" line above instead of the first "Work" line), and not too hard if you use a explicit stack, but I'll leave it as an exercise.

How to combine GROUP BY and ROW_NUMBER?

Wow, the other answers look complex - so I'm hoping I've not missed something obvious.

You can use OVER/PARTITION BY against aggregates, and they'll then do grouping/aggregating without a GROUP BY clause. So I just modified your query to:

select T2.ID AS T2ID
    ,T2.Name as T2Name
    ,T1.ID AS T1ID
    ,T1.Name As T1Name
FROM @t2 T2
    SELECT Rel.t2ID
 --       ,MAX(Rel.t1ID)AS t1ID 
-- the MAX returns an arbitrary ID, what i need is: 
      ,ROW_NUMBER()OVER(Partition By Rel.t2ID Order By Price DESC)As PriceList
        ,SUM(Price)OVER(PARTITION BY Rel.t2ID) AS Price
        FROM @t1 T1 
        INNER JOIN @relation Rel ON Rel.t1ID=T1.ID
--        GROUP BY Rel.t2ID
)AS T1Sum ON  T1Sum.t2ID = T2.ID
where t1Sum.PriceList = 1

Which gives the requested result set.

Where to place JavaScript in an HTML file?

The answer is depends how you are using the objects of javascript. As already pointed loading the javascript files at footer rather than header certainly improves the performance but care should be taken that the objects which are used are initialized later than they are loaded at footer. One more way is load the 'js' files placed in folder which will be available to all the files.

Always show vertical scrollbar in <select>

I guess you cant, this maybe a limitation or not included in the IE browser. I have tried your jsfiddle with IE6-8 and all of it doesn't show the scrollbar and not sure with IE9. While in FF and chrome the scrollbar is shown. I also want to see how to do it in IE if possible.

If you really want to show the scrollbar, you can add a fake scrollbar. If you are familiar with some of the js library which use in RIA. Like in jquery/dojo some of the select is editable, because it is a combination of textbox + select or it can also be a textbox + div.

As an example, see it here a JavaScript that make select like editable.

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

Run all SQL files in a directory

Make sure you have SQLCMD enabled by clicking on the Query > SQLCMD mode option in the management studio.

  1. Suppose you have four .sql files (script1.sql,script2.sql,script3.sql,script4.sql) in a folder c:\scripts.

  2. Create a main script file (Main.sql) with the following:

    :r c:\Scripts\script1.sql
    :r c:\Scripts\script2.sql
    :r c:\Scripts\script3.sql
    :r c:\Scripts\script4.sql

    Save the Main.sql in c:\scripts itself.

  3. Create a batch file named ExecuteScripts.bat with the following:

    SQLCMD -E -d<YourDatabaseName> -ic:\Scripts\Main.sql

    Remember to replace <YourDatabaseName> with the database you want to execute your scripts. For example, if the database is "Employee", the command would be the following:

    SQLCMD -E -dEmployee -ic:\Scripts\Main.sql
  4. Execute the batch file by double clicking the same.

C++ auto keyword. Why is it magic?

It's just taking a generally useless keyword and giving it a new, better functionality. It's standard in C++11, and most C++ compilers with even some C++11 support will support it.

Function ereg_replace() is deprecated - How to clear this bug?

print $input."<hr>".ereg_replace('/&/', ':::', $input);


print $input."<hr>".preg_replace('/&/', ':::', $input);

More example :

$mytext = ereg_replace('[^A-Za-z0-9_]', '', $mytext );

is changed to

$mytext = preg_replace('/[^A-Za-z0-9_]/', '', $mytext );

jQuery selectors on custom data attributes using HTML5

$("ul[data-group='Companies'] li[data-company='Microsoft']") //Get all elements with data-company="Microsoft" below "Companies"

$("ul[data-group='Companies'] li:not([data-company='Microsoft'])") //get all elements with data-company!="Microsoft" below "Companies"

Look in to jQuery Selectors :contains is a selector

here is info on the :contains selector

How to create Python egg file

You are reading the wrong documentation. You want this:

  1. Creating is covered in the distutils documentation in Python's standard library documentation here. The main difference (for python eggs) is you import setup from setuptools, not distutils.

  2. Yep. That should be right.

  3. I don't think so. pyc files can be version and platform dependent. You might be able to open the egg (they should just be zip files) and delete .py files leaving .pyc files, but it wouldn't be recommended.

  4. I'm not sure. That might be “Development Mode”. Or are you looking for some “py2exe” or “py2app” mode?

How do I pass data to Angular routed components?

By default i won't use a guard for this one for me it is more can i enter the route or can i leave it. It is not to share data betweenn them.

If you want to load data before we entered a route just add an resolver to this one this is also part of the Router.

As very basic example:


import { Resolve, ActivatedRoute } from "@angular/router";
import { Observable } from "rxjs";
import { Injectable } from "@angular/core";
import { take } from "rxjs/operators";

export class UserResolver implements Resolve<User> {

        private userService: UserService,
        private route: ActivatedRoute
    ) {}

    resolve(): Observable<firebase.User> {
        return this.route.params.pipe(
            switchMap((params) => this.userService.fetchUser(params.user_id)),

put to the router:

    path: "user/:user_id",
    component: MyUserDetailPage,
    resolve: {
        user: UserResolver

get the data in our component

ngOnInit() {
    const user: firebase.User =;

The downside on this approach is, he will enter the route first if he get the user data not before, this ensures the data for the user has been loaded and is ready on start of the component, but you will stay on the old page as long the data has been loaded (Loading Animation)

How to set border's thickness in percentages?

Modern browsers support vh and vw units, which are a percentage of the window viewport.

So you can have pure CSS borders as a percentage of the window size:

border: 5vw solid red;

Try this example and change window width; the border will change thickness as the window changes size. box-sizing: border-box; may be useful too.

PHP Regex to check date is in YYYY-MM-DD format

If you want to match that type of date, use:

preg_match("~^\d{4}-\d{2}-\d{2}$~", $date)

How to make CSS3 rounded corners hide overflow in Chrome/Opera

Not an answer, but this is a filed bug under the Chromium source:

Unfortunately, doesn't look like there's anyone working on it. :(

If statement in aspx page

Here's a simple one written in VB for an ASPX page:

                If myVar > 1 Then
                    response.write("Greater than 1")
                End If

Java: export to an .jar file in eclipse

Go to file->export->JAR file, there you may select "Export generated class files and sources" and make sure that your project is selected, and all folder under there are also! Good luck!

Table 'performance_schema.session_variables' doesn't exist

mysql -u app -p
mysql> set @@global.show_compatibility_56=ON;

as per worked for me.

How can I print message in Makefile?

$(info your_text) : Information. This doesn't stop the execution.

$(warning your_text) : Warning. This shows the text as a warning.

$(error your_text) : Fatal Error. This will stop the execution.

RSA Public Key format

You can't just change the delimiters from ---- BEGIN SSH2 PUBLIC KEY ---- to -----BEGIN RSA PUBLIC KEY----- and expect that it will be sufficient to convert from one format to another (which is what you've done in your example).

This article has a good explanation about both formats.

What you get in an RSA PUBLIC KEY is closer to the content of a PUBLIC KEY, but you need to offset the start of your ASN.1 structure to reflect the fact that PUBLIC KEY also has an indicator saying which type of key it is (see RFC 3447). You can see this using openssl asn1parse and -strparse 19, as described in this answer.

EDIT: Following your edit, your can get the details of your RSA PUBLIC KEY structure using grep -v -- ----- | tr -d '\n' | base64 -d | openssl asn1parse -inform DER:

    0:d=0  hl=4 l= 266 cons: SEQUENCE          
    4:d=1  hl=4 l= 257 prim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
  265:d=1  hl=2 l=   3 prim: INTEGER           :010001

To decode the SSH key format, you need to use the data format specification in RFC 4251 too, in conjunction with RFC 4253:

   The "ssh-rsa" key format has the following specific encoding:

      string    "ssh-rsa"
      mpint     e
      mpint     n

For example, at the beginning, you get 00 00 00 07 73 73 68 2d 72 73 61. The first four bytes (00 00 00 07) give you the length. The rest is the string itself: 73=s, 68=h, ... -> 73 73 68 2d 72 73 61=ssh-rsa, followed by the exponent of length 1 (00 00 00 01 25) and the modulus of length 256 (00 00 01 00 7f ...).

How to save a BufferedImage as a File

  1. Download and add imgscalr-lib-x.x.jar and imgscalr-lib-x.x-javadoc.jar to your Projects Libraries.
  2. In your code:

    import static org.imgscalr.Scalr.*;
    public static BufferedImage resizeBufferedImage(BufferedImage image, Scalr.Method scalrMethod, Scalr.Mode scalrMode, int width, int height)  {
        BufferedImage bi = image;
        bi = resize( image, scalrMethod, scalrMode, width, height);
    return bi;
    // Save image:
    ImageIO.write(Scalr.resize(etotBImage, 150), "jpg", new File(myDir));

Python 3 print without parenthesis

Using print without parentheses in Python 3 code is not a good idea. Nor is creating aliases, etc. If that's a deal breaker, use Python 2.

However, print without parentheses might be useful in the interactive shell. It's not really a matter of reducing the number of characters, but rather avoiding the need to press Shift twice every time you want to print something while you're debugging. IPython lets you call functions without using parentheses if you start the line with a slash:

Python 3.6.6 (default, Jun 28 2018, 05:43:53)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.4.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: var = 'Hello world'

In [2]: /print var
Hello world

And if you turn on autocall, you won't even need to type the slash:

In [3]: %autocall
Automatic calling is: Smart

In [4]: print var
------> print(var)
Hello world

Escaping single quote in PHP when inserting into MySQL

You have a couple of things fighting in your strings.

  • lack of correct MySQL quoting (mysql_real_escape_string())
  • potential automatic 'magic quote' -- check your gpc_magic_quotes setting
  • embedded string variables, which means you have to know how PHP correctly finds variables

It's also possible that the single-quoted value is not present in the parameters to the first query. Your example is a proper name, after all, and only the second query seems to be dealing with names.

How to upload a file from Windows machine to Linux machine using command lines via PuTTy?

Try using SCP on Windows to transfer files, you can download SCP from Putty's website. Then try running:

pscp.exe filename.extension [email protected]:directory/subdirectory

There is a full length guide here.

What is limiting the # of simultaneous connections my ASP.NET application can make to a web service?

while doing performance testing, the measure i go by is RPS, that is how many requests per second can the server serve within acceptable latency.

theoretically one server can only run as many requests concurrently as number of cores on it..

It doesn't look like the problem is's threading model, since it can potentially serve thousands of rps. It seems like the problem might be your application. Are you using any synchronization primitives ?

also whats the latency on your web services, are they very quick to respond (within microseconds), if not then you might want to consider asynchronous calls, so you dont end up blocking

If this doesnt yeild something, then you might want to profile your code using visual studio or redgate profiler

VBA Subscript out of range - error 9

Suggest the following simplification: capture return value from Workbooks.Add instead of subscripting Windows() afterward, as follows:

Set wkb = Workbooks.Add
wkb.SaveAs ...

wkb.Activate ' instead of Windows(expression).Activate

General Philosophy Advice:

Avoid use Excel's built-ins: ActiveWorkbook, ActiveSheet, and Selection: capture return values, and, favor qualified expressions instead.

Use the built-ins only once and only in outermost macros(subs) and capture at macro start, e.g.

Set wkb = ActiveWorkbook
Set wks = ActiveSheet
Set sel = Selection

During and within macros do not rely on these built-in names, instead capture return values, e.g.

Set wkb = Workbooks.Add 'instead of Workbooks.Add without return value capture
wkb.Activate 'instead of Activeworkbook.Activate

Also, try to use qualified expressions, e.g.

wkb.Sheets("Sheet3").Name = "foo" ' instead of Sheets("Sheet3").Name = "foo"


Set newWks = wkb.Sheets.Add
newWks.Name = "bar" 'instead of ActiveSheet.Name = "bar"

Use qualified expressions, e.g.

newWks.Name = "bar" 'instead of `xyz.Select` followed by Selection.Name = "bar" 

These methods will work better in general, give less confusing results, will be more robust when refactoring (e.g. moving lines of code around within and between methods) and, will work better across versions of Excel. Selection, for example, changes differently during macro execution from one version of Excel to another.

Also please note that you'll likely find that you don't need to .Activate nearly as much when using more qualified expressions. (This can mean the for the user the screen will flicker less.) Thus the whole line Windows(expression).Activate could simply be eliminated instead of even being replaced by wkb.Activate.

(Also note: I think the .Select statements you show are not contributing and can be omitted.)

(I think that Excel's macro recorder is responsible for promoting this more fragile style of programming using ActiveSheet, ActiveWorkbook, Selection, and Select so much; this style leaves a lot of room for improvement.)

inline conditionals in angular.js

I am using the following to conditionally set the class attr when ng-class can't be used (for example when styling SVG):

ng-attr-class="{{someBoolean && 'class-when-true' || 'class-when-false' }}"

The same approach should work for other attribute types.

(I think you need to be on latest unstable Angular to use ng-attr-, I'm currently on 1.1.4)

I have published an article on working with AngularJS+SVG that talks about this and related issues.

onKeyDown event not working on divs in React

You need to write it this way

    style={{ position: "absolute" }}

If onKeyPressed is not bound to this, then try to rewrite it using arrow function or bind it in the component constructor.

Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?

In Python 2.x, it is not guaranteed at all:

>>> False = 5
>>> 0 == False

So it could change. In Python 3.x, True, False, and None are reserved words, so the above code would not work.

In general, with booleans you should assume that while False will always have an integer value of 0 (so long as you don't change it, as above), True could have any other value. I wouldn't necessarily rely on any guarantee that True==1, but on Python 3.x, this will always be the case, no matter what.

How to send email from localhost WAMP Server to send email Gmail Hotmail or so forth?

For me Fake Sendmail works.

What to do:

1) Edit C:\wamp\sendmail\sendmail.ini:
[email protected]

2) Edit php.ini and set sendmail_path

sendmail_path = "C:\wamp\sendmail\sendmail.exe -t"

That's it. Now you can test a mail.

How do I use a C# Class Library in a project?

There are necessary steps that are missing in the above answers to work for all levels of devs:

  1. compile your class library project
  2. the dll file will be available in the bin folder
  3. in another project, right click ProjectName and select "Add" => "Existing Item"
  4. Browser to the bin folder of the class library project and select the dll file (3 & 4 steps are important if you plan to ship your app to other machines)
  5. as others mentioned, add reference to the dll file you "just" added to your project
  6. as @Adam mentioned, just call the library name from anywhere in your program, you do not need a using statement

TypeError: $ is not a function WordPress

I added a custom script file that loaded at the end of the head section, and inserted the following at the top:

(function (jQuery) {
    window.$ = jQuery.noConflict();

(This is a modification of Fanky's answer)

How to display pdf in php

There are quite a few options that can be used: (both tested).

Here are two ways.

header("Content-type: application/pdf");
header("Content-Disposition: inline; filename=filename.pdf");

or: (note the escaped double-quotes). The same need to be use when assigning a name to it.


echo "<iframe src=\"file.pdf\" width=\"100%\" style=\"height:100%\"></iframe>";


I.e.: name="myiframe" id="myiframe"

would need to be changed to:

name=\"myiframe\" id=\"myiframe\" inside PHP.

Be sure to have a look at: this answer on SO for more options on the subject.

Footnote: There are known issues when trying to view PDF files in Windows 8. Installing Adobe Acrobat Reader is a better method to view these types of documents if no browser plug-ins are installed.

Android : How to set onClick event for Button in List item of ListView

I find

final Button yourButton = (Button)view.findViewById(;
yourButton.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

can solve the problem. If you want to get some data when clicking the button, using tags is helpful. Here the button is declared final because it will be used within inner class.

Update .NET web service to use TLS 1.2

if you're using .Net earlier than 4.5 you wont have Tls12 in the enum so state is explicitly mentioned here

ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;

Flexbox not working in Internet Explorer 11

See "Can I Use" for the full list of IE11 Flexbox bugs and more

There are numerous Flexbox bugs in IE11 and other browsers - see flexbox on Can I Use -> Known Issues, where the following are listed under IE11:

  • IE 11 requires a unit to be added to the third argument, the flex-basis property
  • In IE10 and IE11, containers with display: flex and flex-direction: column will not properly calculate their flexed childrens' sizes if the container has min-height but no explicit height property
  • IE 11 does not vertically align items correctly when min-height is used

Also see Philip Walton's Flexbugs list of issues and workarounds.

How to change the date format of a DateTimePicker in

Try this code it works:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim CustomeDate As String = ("#" & DOE.Value.Date.ToString("d/MM/yyyy") & "#")


    dadap = New System.Data.OleDb.OleDbDataAdapter("SELECT * FROM QRY_Tran where FORMAT(qry_tran.doe,'d/mm/yyyy') = " & CustomeDate & "", con)

    ds = New System.Data.DataSet
    Dgview.DataSource = ds.Tables(0)

Note : if u use dd for date representation it will return nothing while selecting 1 to 9 so use d for selection

'Date time format
'MMM     Three-letter month.
'ddd     Three-letter day of the week.
'd       Day of the month.
'HH      Two-digit hours on 24-hour scale.
'mm      Two-digit minutes.
'yyyy    Four-digit year.

The documentation contains a full list of the date formats.

How do I add 1 day to an NSDate?

In swift

var dayComponenet = NSDateComponents() = 1

var theCalendar = NSCalendar.currentCalendar()
var nextDate = theCalendar.dateByAddingComponents(dayComponenet, toDate: NSDate(), options: nil)

generate random double numbers in c++

This snippet is straight from Stroustrup's The C++ Programming Language (4th Edition), §40.7; it requires C++11:

#include <functional>
#include <random>

class Rand_double
    Rand_double(double low, double high)

    double operator()(){ return r(); }

    std::function<double()> r;

#include <iostream>    
int main() {
    // create the random number generator:
    Rand_double rd{0,0.5};

    // print 10 random number between 0 and 0.5
    for (int i=0;i<10;++i){
        std::cout << rd() << ' ';
    return 0;

Cannot change version of project facet Dynamic Web Module to 3.0?

Best and simple steps solved this problem for me is 1) Properties -> Project Facets -> Deselect/unmark the check box of Dynamic Web Module -> Apply 2)Now change to the desired version Apply 3)Check the Dynamic web Module check box.. --Now your are done--

Save bitmap to file function

Two example works for me, for your reference.

Bitmap bitmap = Utils.decodeBase64(base64);
try {
    File file = new File(filePath);
    FileOutputStream fOut = new FileOutputStream(file);
    bitmap.compress(Bitmap.CompressFormat.PNG, 85, fOut);
catch (Exception e) {
    LOG.i(null, "Save file error!");
    return false;

and this one

Bitmap savePic = Utils.decodeBase64(base64);
File file = new File(filePath);
File path = new File(file.getParent());

if (savePic != null) {
    try {
        // build directory
        if (file.getParent() != null && !path.isDirectory()) {
        // output image to file
        FileOutputStream fos = new FileOutputStream(filePath);
        savePic.compress(Bitmap.CompressFormat.PNG, 90, fos);
        ret = true;
    } catch (Exception e) {
} else {
    LOG.i(TAG, "savePicture image parsing error");

How to restore the permissions of files and directories within git if they have been modified?

Git doesn't store file permissions other than executable scripts. Consider using something like git-cache-meta to save file ownership and permissions.

Git can only store two types of modes: 755 (executable) and 644 (not executable). If your file was 444 git would store it has 644.

Reading InputStream as UTF-8

Solved my own problem. This line:

BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));

needs to be:

BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream(), "UTF-8"));

or since Java 7:

BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream(), StandardCharsets.UTF_8));

How to fix request failed on channel 0

Just rebooting a AWS instance works for me to clear the error "shell request failed on channel 0"

Format SQL in SQL Server Management Studio

Late answer, but hopefully worthwhile: The Poor Man's T-SQL Formatter is an open-source (free) T-SQL formatter with complete T-SQL batch/script support (any DDL, any DML), SSMS Plugin, command-line bulk formatter, and other options.

It's available for immediate/online use at, and just today graduated to "version 1.0" (it was in beta version for a few months), having just acquired support for MERGE statements, OUTPUT clauses, and other finicky stuff.

The SSMS Add-in allows you to set your own hotkey (default is Ctrl-K, Ctrl-F, to match Visual Studio), and formats the entire script or just the code you have selected/highlighted, if any. Output formatting is customizable.

In SSMS 2008 it combines nicely with the built-in intelli-sense, effectively providing more-or-less the same base functionality as Red Gate's SQL Prompt (SQL Prompt does, of course, have extra stuff, like snippets, quick object scripting, etc).

Feedback/feature requests are more than welcome, please give it a whirl if you get the chance!

Disclosure: This is probably obvious already but I wrote this library/tool/site, so this answer is also shameless self-promotion :)

How to use underscore.js as a template engine?

The documentation for templating is partial, I watched the source.

The _.template function has 3 arguments:

  1. String text : the template string
  2. Object data : the evaluation data
  3. Object settings : local settings, the _.templateSettings is the global settings object

If no data (or null) given, than a render function will be returned. It has 1 argument:

  1. Object data : same as the data above

There are 3 regex patterns and 1 static parameter in the settings:

  1. RegExp evaluate : "<%code%>" in template string
  2. RegExp interpolate : "<%=code%>" in template string
  3. RegExp escape : "<%-code%>"
  4. String variable : optional, the name of the data parameter in the template string

The code in an evaluate section will be simply evaluated. You can add string from this section with the __p+="mystring" command to the evaluated template, but this is not recommended (not part of the templating interface), use the interpolate section instead of that. This type of section is for adding blocks like if or for to the template.

The result of the code in the interpolate section will added to the evaluated template. If null given back, then empty string will added.

The escape section escapes html with _.escape on the return value of the given code. So its similar than an _.escape(code) in an interpolate section, but it escapes with \ the whitespace characters like \n before it passes the code to the _.escape. I don't know why is that important, it's in the code, but it works well with the interpolate and _.escape - which doesn't escape the white-space characters - too.

By default the data parameter is passed by a with(data){...} statement, but this kind of evaluating is much slower than the evaluating with named variable. So naming the data with the variable parameter is something good...

For example:

var html = _.template(
    "<pre>The \"<% __p+=_.escape(o.text) %>\" is the same<br />" +
        "as the  \"<%= _.escape(o.text) %>\" and the same<br />" +
        "as the \"<%- o.text %>\"</pre>",
        text: "<b>some text</b> and \n it's a line break"
        variable: "o"



The "<b>some text</b> and 
 it's a line break" is the same
as the "<b>some text</b> and 
 it's a line break" and the same
as the "<b>some text</b> and 
 it's a line break"

You can find here more examples how to use the template and override the default settings:

By template loading you have many options, but at the end you always have to convert the template into string. You can give it as normal string like the example above, or you can load it from a script tag, and use the .html() function of jquery, or you can load it from a separate file with the tpl plugin of require.js.

Another option to build the dom tree with laconic instead of templating.

get value from DataTable

You can try changing it to this:

If myTableData.Rows.Count > 0 Then
  For i As Integer = 0 To myTableData.Rows.Count - 1
    ''Dim DataType() As String = myTableData.Rows(i).Item(1)
End If

Note: Your loop needs to be one less than the row count since it's a zero-based index.

Is Xamarin free in Visual Studio 2015?

Updated March 31st, 2016:

We have announced that Visual Studio now includes Xamarin at no extra cost, including Community Edition, which is free for individual developers, open source projects, academic research, education, and small professional teams. There is no size restriction on the Community Edition and offers the same features as the Pro & Enterprise editions. Read more about the update here:

Be sure to browse the store on how to download and get started: and there is a nice FAQ section:

JQuery window scrolling event?

See jQuery.scroll(). You can bind this to the window element to get your desired event hook.

On scroll, then simply check your scroll position:

$(window).scroll(function() {
  var scrollTop = $(window).scrollTop();
  if ( scrollTop > $(headerElem).offset().top ) { 
    // display add

JavaScript variable assignments from tuples

Javascript 1.7 added destructured assignment which allows you to do essentially what you are after.

function getTuple(){
   return ["Bob", 24];
var [a, b] = getTuple();
// a === "bob" , b === 24 are both true

Sending POST data without form

function redir(data) {_x000D_
  document.getElementById('redirect').innerHTML = '<form style="display:none;" position="absolute" method="post" action="location.php"><input id="redirbtn" type="submit" name="value" value=' + data + '></form>';_x000D_
<button onclick="redir('dataToBeSent');">Next Page</button>_x000D_
<div id="redirect"></div>

You can use this method which creates a new hidden form whose "data" is sent by "post" to "location.php" when a button[Next Page] is clicked.

Selenium -- How to wait until page is completely loaded

It seems that you need to wait for the page to be reloaded before clicking on the "Add" button. In this case you could wait for the "Add Item" element to become stale before clicking on the reloaded element:

WebDriverWait wait = new WebDriverWait(driver, 20);
By addItem = By.xpath("//input[.='Add Item']");

// get the "Add Item" element
WebElement element = wait.until(ExpectedConditions.presenceOfElementLocated(addItem));

//trigger the reaload of the page

// wait the element "Add Item" to become stale

// click on "Add Item" once the page is reloaded

Min/Max-value validators in mvc

I don't think min/max validations attribute exist. I would use something like

[Range(1, Int32.MaxValue)]

for minimum value 1 and

[Range(Int32.MinValue, 10)]

for maximum value 10

"Content is not allowed in prolog" when parsing perfectly valid XML on GAE

I had a tab character instead of spaces. Replacing the tab '\t' fixed the problem.

Cut and paste the whole doc into an editor like Notepad++ and display all characters.

Is there a way to rollback my last push to Git?

First you need to determine the revision ID of the last known commit. You can use HEAD^ or HEAD~{1} if you know you need to reverse exactly one commit.

git reset --hard <revision_id_of_last_known_good_commit>
git push --force

How do I make a redirect in PHP?

Most of these answers are forgetting a very important step!

header("Location: myOtherPage.php");

Leaving that vital second line out might see you end up on The Daily WTF. The problem is that browsers do not have to respect the headers which your page return, so with headers being ignored, the rest of the page will be executed without a redirect.

import sun.misc.BASE64Encoder results in error compiled in Eclipse

I know this is very Old post. Since we don't have any thing sun.misc in maven we can easily use

StringUtils.newStringUtf8(Base64.encodeBase64(encVal)); From org.apache.commons.codec.binary.Base64

INNER JOIN vs LEFT JOIN performance in SQL Server

If everything works as it should it shouldn't, BUT we all know everything doesn't work the way it should especially when it comes to the query optimizer, query plan caching and statistics.

First I would suggest rebuilding index and statistics, then clearing the query plan cache just to make sure that's not screwing things up. However I've experienced problems even when that's done.

I've experienced some cases where a left join has been faster than a inner join.

The underlying reason is this: If you have two tables and you join on a column with an index (on both tables). The inner join will produce the same result no matter if you loop over the entries in the index on table one and match with index on table two as if you would do the reverse: Loop over entries in the index on table two and match with index in table one. The problem is when you have misleading statistics, the query optimizer will use the statistics of the index to find the table with least matching entries (based on your other criteria). If you have two tables with 1 million in each, in table one you have 10 rows matching and in table two you have 100000 rows matching. The best way would be to do an index scan on table one and matching 10 times in table two. The reverse would be an index scan that loops over 100000 rows and tries to match 100000 times and only 10 succeed. So if the statistics isn't correct the optimizer might choose the wrong table and index to loop over.

If the optimizer chooses to optimize the left join in the order it is written it will perform better than the inner join.

BUT, the optimizer may also optimize a left join sub-optimally as a left semi join. To make it choose the one you want you can use the force order hint.

What tool can decompile a DLL into C++ source code?

This might be impossible or at least very hard. The DLL's contents don't depend (a lot) on it being written in C++; it's all machine code. That code might have been optimized so a lot of information that was present in the original source code is simply gone.

That said, here is one article that goes through a lot of material about doing this.

Converting to upper and lower case in Java

String a = "ABCD"

using this


all letters will convert to simple, "abcd"
using this


all letters will convert to Capital, "ABCD"

this conver first letter to capital:


this conver other letter Simple


we can get sum of these two

a.substring(0,1).toUpperCase() + a.substring(1).toLowerCase();

result = "Abcd"

Amazon S3 boto - how to create a folder?

Use this:

import boto3
s3 = boto3.client('s3')
bucket_name = "YOUR-BUCKET-NAME"
directory_name = "DIRECTORY/THAT/YOU/WANT/TO/CREATE" #it's name of your folders
s3.put_object(Bucket=bucket_name, Key=(directory_name+'/'))

MySQL - How to increase varchar size of an existing column in a database without breaking existing data?

I'd like explain the different alter table syntaxes - See the MySQL documentation

For adding/removing defaults on a column:

ALTER TABLE table_name

For renaming a column, changing it's data type and optionally changing the column order:

ALTER TABLE table_name
CHANGE [COLUMN] old_col_name new_col_name column_definition
[FIRST|AFTER col_name]

For changing a column's data type and optionally changing the column order:

ALTER TABLE table_name
MODIFY [COLUMN] col_name column_definition
[FIRST | AFTER col_name]

JavaScript pattern for multiple constructors

How do you find this one?

function Foobar(foobar) {
    this.foobar = foobar;

Foobar.prototype = {
    foobar: null

Foobar.fromComponents = function(foo, bar) {
    var foobar = foo + bar;
    return new Foobar(foobar);

//usage: the following two lines give the same result
var x = Foobar.fromComponents('Abc', 'Cde');
var y = new Foobar('AbcDef')

reading and parsing a TSV file, then manipulating it for saving as CSV (*efficiently*)

You should use the csv module to read the tab-separated value file. Do not read it into memory in one go. Each row you read has all the information you need to write rows to the output CSV file, after all. Keep the output file open throughout.

import csv

with open('sample.txt', newline='') as tsvin, open('new.csv', 'w', newline='') as csvout:
    tsvin = csv.reader(tsvin, delimiter='\t')
    csvout = csv.writer(csvout)

    for row in tsvin:
        count = int(row[4])
        if count > 0:
            csvout.writerows([row[2:4] for _ in range(count)])

or, using the itertools module to do the repeating with itertools.repeat():

from itertools import repeat
import csv

with open('sample.txt', newline='') as tsvin, open('new.csv', 'w', newline='') as csvout:
    tsvin = csv.reader(tsvin, delimiter='\t')
    csvout = csv.writer(csvout)

    for row in tsvin:
        count = int(row[4])
        if count > 0:
            csvout.writerows(repeat(row[2:4], count))

Python not working in the command line of git bash

I don't see next option in a list of answers, but I can get interactive prompt with "-i" key:

$ python -i
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55)
Type "help", "copyright", "credits" or "license" for more information.

How to determine programmatically the current active profile using Spring boot

It doesn't matter is your app Boot or just raw Spring. There is just enough to inject org.springframework.core.env.Environment to your bean.

private Environment environment;


Get viewport/window height in ReactJS

You can also try this:

constructor(props) {
        this.state = {height: props.height, width:props.width};

          console.log("WINDOW : ",window);
          this.setState({height: window.innerHeight + 'px',width:window.innerWidth+'px'});

render() {
        console.log("VIEW : ",this.state);

R color scatter plot points based on values

Best thing to do here is to add a column to the data object to represent the point colour. Then update sections of it by filtering.

data<- read.table('sample_data.txtt', header=TRUE,
# Create new column filled with default colour
# Set new column values to appropriate colours
# Plot all points at once, using newly generated colours
plot(data$col_name1,data$col_name2, ylim=c(0,5), col=data$Colour, ylim=c(0,10))

It should be clear how to adapt this for plots with more colours & conditions.

Show/hide image with JavaScript

You can do this with jquery just visit to get the link then do something like this

<a id="show_image">Show Image</a>
<img id="my_images" style="display:none" src="">

<script src="//"></script>
      $('#show_image').on("click", function(){

or if you would like the link to turn the image on and off do this

<a id="show_image">Show Image</a>
<img id="my_images" style="display:none;" src="">

<script src="//"></script>
      $('#show_image').on("click", function(){

basic authorization command for curl

One way, provide --user flag as part of curl, as follows:

curl --user username:password

Another way is to get Base64 encoded token of "username:password" from any online website like - and pass it as Authorization header of curl as follows:

curl -i -H 'Authorization:Basic dXNlcm5hbWU6cGFzc3dvcmQ=' http://localhost:8080/

Here, dXNlcm5hbWU6cGFzc3dvcmQ= is Base64 encoded token of username:password.

Best way to pretty print a hash

If you don't have any fancy gem action, but do have JSON, this CLI line will work on a hash:

puts JSON.pretty_generate(my_hash).gsub(":", " =>")

  :key1 => "value1",

  :key2 => "value2",

  :key3 => "value3"

Retrieve filename from file descriptor in C

You can use fstat() to get the file's inode by struct stat. Then, using readdir() you can compare the inode you found with those that exist (struct dirent) in a directory (assuming that you know the directory, otherwise you'll have to search the whole filesystem) and find the corresponding file name. Nasty?

problem with php mail 'From' header

It turns out the original poster's server (blueHost) has a FAQ concerning this very question.

Article 206.

This is because our servers require you (or your script) to use a properly formatted, valid From: field in the email's header. If the From: field is not formatted correctly, empty or the email address does not exist in the cPanel, the From: address will be changed to

You must change the script you are using to correctly use a valid From: header.

Examples of headers that should work would be:

From: [email protected]
From: "user" <[email protected]>

Examples of headers that will NOT work:

From: "[email protected]"
From: user @
From: [email protected] <[email protected]>

Our servers will not accept the name for the email address and the email address to be the same. It will not accept a double declaration of the email address.

For scripts such as Joomla and Wordpress, you will need to follow their documentation for formatting the from fields properly. Wordpress will require the Mail From plugin.

Note: The email address you use must be a valid created account in the cPanel.

How do I remove leading whitespace in Python?

The lstrip() method will remove leading whitespaces, newline and tab characters on a string beginning:

>>> '     hello world!'.lstrip()
'hello world!'


As balpha pointed out in the comments, in order to remove only spaces from the beginning of the string, lstrip(' ') should be used:

>>> '   hello world with 2 spaces and a tab!'.lstrip(' ')
'\thello world with 2 spaces and a tab!'

Related question:

How do you obtain a Drawable object from a resource id in android package?

From API 21 `getDrawable(int id)` is deprecated

So now you need to use

ResourcesCompat.getDrawable(context.getResources(), R.drawable.img_user, null)

But Best way to do is :

- You should create one common class for getting drawable and colors because if in future have any deprecation then you no need to do changes everywhere in your project.You just change in this method
object ResourceUtils {
    fun getColor(context: Context, color: Int): Int {
        return ResourcesCompat.getColor(context.getResources(), color, null)

    fun getDrawable(context: Context, drawable: Int): Drawable? {
        return ResourcesCompat.getDrawable(context.getResources(), drawable, null)

use this method like :

Drawable img=ResourceUtils.getDrawable(context, R.drawable.img_user)

How do I display Ruby on Rails form validation error messages one at a time?

ActiveRecord stores validation errors in an array called errors. If you have a User model then you would access the validation errors in a given instance like so:

@user = User.create[params[:user]] # create will automatically call validators

if @user.errors.any? # If there are errors, do something

  # You can iterate through all messages by attribute type and validation message
  # This will be something like:
  # attribute = 'name'
  # message = 'cannot be left blank'
  @user.errors.each do |attribute, message|
    # do stuff for each error

  # Or if you prefer, you can get the full message in single string, like so:
  # message = 'Name cannot be left blank'
  @users.errors.full_messages.each do |message|
    # do stuff for each error

  # To get all errors associated with a single attribute, do the following:
  if @user.errors.include?(:name)
    name_errors = @user.errors[:name]

    if name_errors.kind_of?(Array)
      name_errors.each do |error|
        # do stuff for each error on the name attribute
      error = name_errors
      # do stuff for the one error on the name attribute.

Of course you can also do any of this in the views instead of the controller, should you want to just display the first error to the user or something.

Difference between Width:100% and width:100vw?

You can solve this issue be adding max-width:

#element {
   width: 100vw;
   height: 100vw;
   max-width: 100%;

When you using CSS to make the wrapper full width using the code width: 100vw; then you will notice a horizontal scroll in the page, and that happened because the padding and margin of html and body tags added to the wrapper size, so the solution is to add max-width: 100%

I can't install pyaudio on Windows? How to solve "error: Microsoft Visual C++ 14.0 is required."?

If you have anaconda install than you just need to use command: conda install PyAudio.

In order to execute this command you must set thePYTHONPATH environment variable in anaconda.

SQL Server equivalent to Oracle's CREATE OR REPLACE VIEW

I typically use something like this:

if exists (select * from dbo.sysobjects
  where id = object_id(N'dbo.MyView') and
  OBJECTPROPERTY(id, N'IsView') = 1)
drop view dbo.MyView
create view dbo.MyView [...]

Can I use if (pointer) instead of if (pointer != NULL)?

Yes. In fact you should. If you're wondering if it creates a segmentation fault, it doesn't.

delete a column with awk or sed

With GNU awk for inplace editing, \s/\S, and gensub() to delete

1) the FIRST field:

awk -i inplace '{sub(/^\S+\s*/,"")}1' file


awk -i inplace '{$0=gensub(/^\S+\s*/,"",1)}1' file

2) the LAST field:

awk -i inplace '{sub(/\s*\S+$/,"")}1' file


awk -i inplace '{$0=gensub(/\s*\S+$/,"",1)}1' file

3) the Nth field where N=3:

awk -i inplace '{$0=gensub(/\s*\S+/,"",3)}1' file

Without GNU awk you need a match()+substr() combo or multiple sub()s + vars to remove a middle field. See also Print all but the first three columns.

Getting Cannot bind argument to parameter 'Path' because it is null error in powershell

$_ is the active object in the current pipeline. You've started a new pipeline with $FOLDLIST | ... so $_ represents the objects in that array that are passed down the pipeline. You should stash the FileInfo object from the first pipeline in a variable and then reference that variable later e.g.:

write-host $NEWN.Length
$file = $_
Move-Item $file.Name $DPATH

How to kill a while loop with a keystroke?

For Python 3.7, I copied and changed the very nice answer by user297171 so it works in all scenarios in Python 3.7 that I tested.

import threading as th

keep_going = True
def key_capture_thread():
    global keep_going
    keep_going = False

def do_stuff():
    th.Thread(target=key_capture_thread, args=(), name='key_capture_thread', daemon=True).start()
    while keep_going:
        print('still going...')


What does 'useLegacyV2RuntimeActivationPolicy' do in the .NET 4 config?

After a bit of time (and more searching), I found this blog entry by Jomo Fisher.

One of the recent problems we’ve seen is that, because of the support for side-by-side runtimes, .NET 4.0 has changed the way that it binds to older mixed-mode assemblies. These assemblies are, for example, those that are compiled from C++\CLI. Currently available DirectX assemblies are mixed mode. If you see a message like this then you know you have run into the issue:

Mixed mode assembly is built against version 'v1.1.4322' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.


The good news for applications is that you have the option of falling back to .NET 2.0 era binding for these assemblies by setting an app.config flag like so:

<startup useLegacyV2RuntimeActivationPolicy="true">
  <supportedRuntime version="v4.0"/>

So it looks like the way the runtime loads mixed-mode assemblies has changed. I can't find any details about this change, or why it was done. But the useLegacyV2RuntimeActivationPolicy attribute reverts back to CLR 2.0 loading.

preg_match(); - Unknown modifier '+'

This happened to me because I put a variable in the regex and sometimes its string value included a slash. Solution: preg_quote.

how to run the command mvn eclipse:eclipse

The m2e plugin uses it's own distribution of Maven, packaged with the plugin.

In order to use Maven from command line, you need to have it installed as a standalone application. Here is an instruction explaining how to do it in Windows

Once Maven is properly installed (i.e. be sure that MAVEN_HOME, JAVA_HOME and PATH variables are set correctly): you must run mvn eclipse:eclipse from the directory containing the pom.xml.

Regular expression for address field validation

See the answer to this question on address validating with regex: regex street address match

The problem is, street addresses vary so much in formatting that it's hard to code against them. If you are trying to validate addresses, finding if one isn't valid based on its format is mighty hard to do. This would return the following address (253 N. Cherry St. ), anything with its same format:


This allows 1-5 digits for the house number, a space, a character followed by a period (for N. or S.), 1-2 words for the street name, finished with an abbreviation (like st. or rd.).

Because regex is used to see if things meet a standard or protocol (which you define), you probably wouldn't want to allow for the addresses provided above, especially the first one with the dash, since they aren't very standard. you can modify my above code to allow for them if you wish--you could add


to allow for a dash but not require one.

In addition, is a quick and interactive way to learn regex. Try it out with the addresses above.

post ajax data to PHP and return data

For the JS, try

data: {id: the_id}
success: function(data) {
        alert('the server returned ' + data;


$the_id = intval($_POST['id']);

in PHP

How to dynamically change header based on AngularJS partial view?

jkoreska's solution is perfect if you know the titles before hand, but you may need to set the title based on data you get from a resource etc.

My solution requires a single service. Since the rootScope is the base of all DOM elements, we don't need to put a controller on the html element like someone mentioned


app.service('Page', function($rootScope){
    return {
        setTitle: function(title){
            $rootScope.title = title;


doctype html
// ...

All controllers that need to change title

app.controller('SomeController', function(Page){
    Page.setTitle("Some Title");

changing the language of error message in required field in html5 contact form

This work for me.

<input oninvalid="this.setCustomValidity('custom text on invalid')" onchange="this.setCustomValidity('')" required>

onchange is a must!

What is the best algorithm for overriding GetHashCode?

Most of my work is done with database connectivity which means that my classes all have a unique identifier from the database. I always use the ID from the database to generate the hashcode.

// Unique ID from database
private int _id;

  return _id.GetHashCode();

Call Python function from JavaScript code

From the document.getElementsByTagName I guess you are running the javascript in a browser.

The traditional way to expose functionality to javascript running in the browser is calling a remote URL using AJAX. The X in AJAX is for XML, but nowadays everybody uses JSON instead of XML.

For example, using jQuery you can do something like:

    function(data, textStatus, jqXHR) {

You will need to implement a python webservice on the server side. For simple webservices I like to use Flask.

A typical implementation looks like:

def my_webservice():
    return jsonify(result=some_function(**request.args)) 

You can run IronPython (kind of Python.Net) in the browser with silverlight, but I don't know if NLTK is available for IronPython.

How can I change the Y-axis figures into percentages in a barplot?

Borrowed from @Deena above, that function modification for labels is more versatile than you might have thought. For example, I had a ggplot where the denominator of counted variables was 140. I used her example thus:

scale_y_continuous(labels = function(x) paste0(round(x/140*100,1), "%"), breaks = seq(0, 140, 35))

This allowed me to get my percentages on the 140 denominator, and then break the scale at 25% increments rather than the weird numbers it defaulted to. The key here is that the scale breaks are still set by the original count, not by your percentages. Therefore the breaks must be from zero to the denominator value, with the third argument in "breaks" being the denominator divided by however many label breaks you want (e.g. 140 * 0.25 = 35).

How to specify different Debug/Release output directories in QMake .pro file

For my Qt project, I use this scheme in *.pro file:

HEADERS += src/dialogs.h
SOURCES += src/main.cpp \

Release:DESTDIR = release
Release:OBJECTS_DIR = release/.obj
Release:MOC_DIR = release/.moc
Release:RCC_DIR = release/.rcc
Release:UI_DIR = release/.ui

Debug:DESTDIR = debug
Debug:OBJECTS_DIR = debug/.obj
Debug:MOC_DIR = debug/.moc
Debug:RCC_DIR = debug/.rcc
Debug:UI_DIR = debug/.ui

It`s simple, but nice! :)

How to generate .angular-cli.json file in Angular Cli?

In angular.json you can insert all css and js file in your template. Other ways, you can use from Style.css in src folder for load stylesheets.

@import "../src/fonts/font-awesome/css/font-awesome.min.css";
@import "../src/css/bootstrap.min.css";
@import "../src/css/now-ui-kit.css";
@import "../src/css/plugins/owl.carousel.css";
@import "../src/css/plugins/owl.theme.default.min.css";
@import "../src/css/main.css";

What causes java.lang.IncompatibleClassChangeError?

For some reason the same exception is also thrown when using JNI and passing the jclass argument instead of the jobject when calling a Call*Method().

This is similar to the answer from Ogre Psalm33.

void example(JNIEnv *env, jobject inJavaList) {
    jclass class_List = env->FindClass("java/util/List");

    jmethodID method_size = env->GetMethodID(class_List, "size", "()I");
    long size = env->CallIntMethod(class_List, method_size); // should be passing 'inJavaList' instead of 'class_List'

    std::cout << "LIST SIZE " << size << std::endl;

I know it is a bit late to answer this question 5 years after being asked but this is one of the top hits when searching for java.lang.IncompatibleClassChangeError so I wanted to document this special case.

Python - difference between two strings

What you are asking for is a specialized form of compression. xdelta3 was designed for this particular kind of compression, and there's a python binding for it, but you could probably get away with using zlib directly. You'd want to use zlib.compressobj and zlib.decompressobj with the zdict parameter set to your "base word", e.g. afrykanerskojezyczny.

Caveats are zdict is only supported in python 3.3 and higher, and it's easiest to code if you have the same "base word" for all your diffs, which may or may not be what you want.

When to use Common Table Expression (CTE)

Today we are going to learn about Common table expression that is a new feature which was introduced in SQL server 2005 and available in later versions as well.

Common table Expression :- Common table expression can be defined as a temporary result set or in other words its a substitute of views in SQL Server. Common table expression is only valid in the batch of statement where it was defined and cannot be used in other sessions.

Syntax of declaring CTE(Common table expression) :-

with [Name of CTE]
Body of common table expression

Lets take an example :-

CREATE TABLE Employee([EID] [int] IDENTITY(10,5) NOT NULL,[Name] [varchar](50) NULL)

insert into Employee(Name) values('Neeraj')
insert into Employee(Name) values('dheeraj')
insert into Employee(Name) values('shayam')
insert into Employee(Name) values('vikas')
insert into Employee(Name) values('raj')

insert into dept values(10,'IT')
insert into dept values(15,'Finance')
insert into dept values(20,'Admin')
insert into dept values(25,'HR')
insert into dept values(10,'Payroll')

I have created two tables employee and Dept and inserted 5 rows in each table. Now I would like to join these tables and create a temporary result set to use it further.

With CTE_Example(EID,Name,DeptName)
select Employee.EID,Name,DeptName from Employee 
inner join DEPT on Employee.EID =DEPT.EID
select * from CTE_Example

Lets take each line of the statement one by one and understand.

To define CTE we write "with" clause, then we give a name to the table expression, here I have given name as "CTE_Example"

Then we write "As" and enclose our code in two brackets (---), we can join multiple tables in the enclosed brackets.

In the last line, I have used "Select * from CTE_Example" , we are referring the Common table expression in the last line of code, So we can say that Its like a view, where we are defining and using the view in a single batch and CTE is not stored in the database as an permanent object. But it behaves like a view. we can perform delete and update statement on CTE and that will have direct impact on the referenced table those are being used in CTE. Lets take an example to understand this fact.

With CTE_Example(EID,DeptName)
select EID,DeptName from DEPT 
delete from CTE_Example where EID=10 and DeptName ='Payroll'

In the above statement we are deleting a row from CTE_Example and it will delete the data from the referenced table "DEPT" that is being used in the CTE.

Simple way to get element by id within a div tag?

You don't want to do this. It is invalid HTML to have more than one element with the same id. Browsers won't treat that well, and you will have undefined behavior, meaning you have no idea what the browser will give you when you select an element by that id, it could be unpredictable.

You should be using a class, or just iterating through the inputs and keeping track of an index.

Try something like this:

var div2 = document.getElementById('div2');
for(i = j = 0; i < div2.childNodes.length; i++)
    if(div2.childNodes[i].nodeName == 'INPUT'){
        var input = div2.childNodes[i];
        alert('This is edit'+j+': '+input);


How to install PyQt4 in anaconda?

How to install PyQt4 on anaconda python 2 on Windows:

At first I have tried to isntall pyqt4 via pip install:

C:\Users\myuser\Anaconda2\Scripts\pip.exe search pyqt4 > pyqt4.txt

It shows:

PyQt4 (4.11.4) - Python bindings for the Qt cross platform GUI toolkit

But when I tried to install, it gives an error:

C:\Users\myuser\Anaconda2\Scripts\pip.exe install PyQt4
Collecting PyQt4
  Could not find a version that satisfies the requirement PyQt4 (from versions:
No matching distribution found for PyQt4

Seems this answer is realated to this problem:

Then I have tried to install it via conda install ( How to install PyQt4 in anaconda? ) :

C:\Users\myuser\Anaconda2\Scripts\conda.exe search pyqt

It shows:

pyqt                         4.10.4                   py26_0  defaults        
                             4.10.4                   py27_0  defaults        
                             4.10.4                   py33_0  defaults        
                             4.10.4                   py34_0  defaults        
                             4.10.4                   py26_1  defaults        
                             4.10.4                   py27_1  defaults        
                             4.10.4                   py33_1  defaults        
                             4.10.4                   py34_1  defaults        
                             4.11.4                   py27_0  defaults        
                             4.11.4                   py35_0  defaults        
                             4.11.4                   py27_2  defaults        
                             4.11.4                   py34_2  defaults        
                             4.11.4                   py35_2  defaults        
                             4.11.4                   py27_3  defaults        
                             4.11.4                   py34_3  defaults        
                             4.11.4                   py35_3  defaults        
                             4.11.4                   py27_4  defaults        
                             4.11.4                   py34_4  defaults        
                             4.11.4                   py35_4  defaults        
                             4.11.4                   py27_5  defaults        
                             4.11.4                   py34_5  defaults        
                             4.11.4                   py35_5  defaults        
                             4.11.4                   py27_6  defaults        
                             4.11.4                   py34_6  defaults        
                             4.11.4                   py35_6  defaults        
                             4.11.4                   py27_7  defaults        
                             4.11.4                   py34_7  defaults        
                             4.11.4                   py35_7  defaults        
                             5.6.0                    py27_0  defaults        
                             5.6.0                    py34_0  defaults        
                             5.6.0                    py35_0  defaults        
                             5.6.0                    py27_1  defaults        
                             5.6.0                    py34_1  defaults        
                             5.6.0                    py35_1  defaults        
                             5.6.0                    py27_2  defaults        
                             5.6.0                    py34_2  defaults        
                             5.6.0                    py35_2  defaults        
                             5.6.0                    py36_2  defaults        
                             5.6.0            py27h224ed30_5  defaults        
                             5.6.0            py35hd46907b_5  defaults        
                             5.6.0            py36hb5ed885_5  defaults  

But it gives error:

C:\Users\myuser\Anaconda2\Scripts\conda.exe install pyqt=4.11.4
Fetching package metadata .............
Solving package specifications: .

UnsatisfiableError: The following specifications were found to be in conflict:
  - navigator-updater -> pyqt >=5.6 -> qt 5.6.*
  - pyqt 4.11.4* -> qt >=4.8.6,<5.0
  - pyqt 4.11.4* -> sip >=4.16.4,<4.18
Use "conda info <package>" to see the dependencies for each package.

Same with -c parameter:

C:\Users\myuser\Anaconda2\Scripts\conda.exe install -c anaconda pyqt=4.11.4
Fetching package metadata ...............
Solving package specifications: .

UnsatisfiableError: The following specifications were found to be in conflict:
  - navigator-updater -> pyqt >=5.6 -> qt 5.6.*
  - pyqt 4.11.4* -> qt >=4.8.6,<5.0
  - pyqt 4.11.4* -> sip >=4.16.4,<4.18
Use "conda info <package>" to see the dependencies for each package.

Then I tried to uninstall pyqt:

C:\Users\myuser\Anaconda2\Scripts\conda.exe uninstall pyqt

And installed it again:

C:\Users\myuser\Anaconda2\Scripts\conda.exe install -c anaconda pyqt=4.11.4

And finnaly it works!

to remove first and last element in array

push() adds a new element to the end of an array.
pop() removes an element from the end of an array.

unshift() adds a new element to the beginning of an array.
shift() removes an element from the beginning of an array.

To remove first element from an array arr , use arr.shift()
To remove last element from an array arr , use arr.pop()