Programs & Examples On #Typoscript

TypoScript is a descriptive language which defines how a website in the CMS TYPO3 is rendered. TypoScript mainly defines configuration values that are passed to the systems php code. It is object-based and organized in a tree-like system.

Using setImageDrawable dynamically to set image in an ImageView

a piece of my project, everything works! )

    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        final ModelSystemTraining modelSystemTraining = items.get(position);

int icon = context.getResources().getIdentifier(String.valueOf(modelSystemTraining.getItemIcon()), "drawable", context.getPackageName());

        final FragmentViewHolderSystem fragmentViewHolderSystem = (FragmentViewHolderSystem) holder;
        final View itemView = fragmentViewHolderSystem.itemView;
//                Set Icon
//                Set Title
//                Set Desc

Vue.js - How to properly watch for nested data

Another way to add that I used to 'hack' this solution was to do this: I set up a seperate computed value that would simply return the nested object value.

data : function(){
    return {
        my_object : {
            my_deep_object : {
                my_value : "hello world";
computed : {
    helper_name : function(){
        return this.my_object.my_deep_object.my_value;
watch : {
    helper_name : function(newVal, oldVal){
        // do this...

Java synchronized method lock on object, or method?

Synchronized on the method declaration is syntactical sugar for this:

 public void addA() {
     synchronized (this) {

On a static method it is syntactical sugar for this:

 ClassA {
     public static void addA() {
          synchronized(ClassA.class) {

I think if the Java designers knew then what is understood now about synchronization, they would not have added the syntactical sugar, as it more often than not leads to bad implementations of concurrency.

Chrome hangs after certain amount of data transfered - waiting for available socket

Chrome is a Chromium-based browser and Chromium-based browsers only allow maximum 6 open socket connections at a time, when the 7th connection starts up it will just sit idle and wait for one of the 6 which are running to stop and then it will start running. Hence the error code ‘waiting for available sockets’, the 7th one will wait for one of those 6 sockets to become available and then it will start running.

You can either

multiple where condition codeigniter

$wherecond = "( ( ( username ='" . $username . "' OR status='" . $status . "') AND (id='" . $id . "') ) )"; $this->db->where($wherecond);

If you want to add AND and OR conditions at a time. this will work.

How can I pass an Integer class correctly by reference?

There are two problems:

  1. Integer is pass by value, not by reference. Changing the reference inside a method won't be reflected into the passed-in reference in the calling method.
  2. Integer is immutable. There's no such method like Integer#set(i). You could otherwise just make use of it.

To get it to work, you need to reassign the return value of the inc() method.

integer = inc(integer);

To learn a bit more about passing by value, here's another example:

public static void main(String... args) {
    String[] strings = new String[] { "foo", "bar" };
    System.out.println(Arrays.toString(strings)); // still [foo, bar]
    System.out.println(Arrays.toString(strings)); // [foo, foo]
public static void changeReference(String[] strings) {
    strings = new String[] { "foo", "foo" };
public static void changeValue(String[] strings) {
    strings[1] = "foo";

C++ compiling on Windows and Linux: ifdef switch

It depends on the used compiler.

For example, Windows' definition can be WIN32 or _WIN32.

And Linux' definition can be UNIX or __unix__ or LINUX or __linux__.

No Persistence provider for EntityManager named

I just copied the META-INF into src and worked!

Difference between Activity and FragmentActivity

FragmentActivity is part of the support library, while Activity is the framework's default class. They are functionally equivalent.

You should always use FragmentActivity and instead of the platform default Activity and classes. Using the platform defaults mean that you are relying on whatever implementation of fragments is used in the device you are running on. These are often multiple years old, and contain bugs that have since been fixed in the support library.

Load CSV file with Spark

If your csv data happens to not contain newlines in any of the fields, you can load your data with textFile() and parse it

import csv
import StringIO

def loadRecord(line):
    input = StringIO.StringIO(line)
    reader = csv.DictReader(input, fieldnames=["name1", "name2"])

input = sc.textFile(inputFile).map(loadRecord)

How to convert int to string on Arduino?

Serial.println(val, format)

for more you can visit to the site of arduino

wish this will help you. thanks!


In short, git is trying to access a repo it considers on another filesystem and to tell it explicitly that you're okay with this, you must set the environment variable GIT_DISCOVERY_ACROSS_FILESYSTEM=1

I'm working in a CI/CD environment and using a dockerized git so I have to set it in that environment docker run -e GIT_DISCOVERY_ACROSS_FILESYSTEM=1 -v $(pwd):/git --rm alpine/git rev-parse --short HEAD\'

If you're curious: Above mounts $(pwd) into the git docker container and passes "rev-parse --short HEAD" to the git command in the container, which it then runs against that mounted volums.

Kill detached screen session

You can just go to the place where the screen session is housed and run:

 screen -ls

which results in

 There is a screen on:
         26727.pts-0.devxxx      (Attached)
 1 Socket in /tmp/uscreens/S-xxx. <------ this is where the session is.

And just remove it:

  1. cd /tmp/uscreens/S-xxx
  2. ls
  3. 26727.pts-0.devxxx
  4. rm 26727.pts-0.devxxx
  5. ls

The uscreens directory will not have the 26727.pts-0.devxxx file in it anymore. Now to make sure just type this:

screen -ls

and you should get:

No Sockets found in /tmp/uscreens/S-xxx.

Java double comparison epsilon

While I agree with the idea that double is bad for money, still the idea of comparing doubles has interest. In particular the suggested use of epsilon is only suited to numbers in a specific range. Here is a more general use of an epsilon, relative to the ratio of the two numbers (test for 0 is omitted):

boolean equal(double d1, double d2) {
  double d = d1 / d2;
  return (Math.abs(d - 1.0) < 0.001);

How to get the current loop index when using Iterator?

See here.

iterator.nextIndex() would provide index of element that would be returned by subsequent call to next().

Force uninstall of Visual Studio

I was running in to the same issue, but have just managed a full uninstall by means of trusty old CMD:

D:\vs_ultimate.exe /uninstall /force

Where D: is the location of your installation media (mounted iso, etc).

You could also pass /passive (no user input required - just progress displayed) or /quiet to the above command line.

EDIT: Adding link below to MSDN article mentioning that this forcibly removes ALL installed components.

Also, to ensure link rot doesn't invalidate this, adding brief text below from original article.

Starting with Visual Studio 2013, you can forcibly remove almost all components. A few core components – like the .NET Framework and VC runtimes – are left behind because of their ubiquity, though you can remove those separately from Programs and Features if you really want.

Warning: This will remove all components regardless of whether other products require them. This may cause other products to function incorrectly or not function at all.

Good luck!

Equivalent VB keyword for 'break'

In both Visual Basic 6.0 and VB.NET you would use:

  • Exit For to break from For loop
  • Wend to break from While loop
  • Exit Do to break from Do loop

depending on the loop type. See Exit Statements for more details.

How to get user agent in PHP

You could also use the php native funcion get_browser()

IMPORTANT NOTE: You should have a browscap.ini file.

What does the question mark in Java generics' type parameter mean?

? extends HasWord

means "A class/interface that extends HasWord." In other words, HasWord itself or any of its children... basically anything that would work with instanceof HasWord plus null.

In more technical terms, ? extends HasWord is a bounded wildcard, covered in Item 31 of Effective Java 3rd Edition, starting on page 139. The same chapter from the 2nd Edition is available online as a PDF; the part on bounded wildcards is Item 28 starting on page 134.

Update: PDF link was updated since Oracle removed it a while back. It now points to the copy hosted by the Queen Mary University of London's School of Electronic Engineering and Computer Science.

Update 2: Lets go into a bit more detail as to why you'd want to use wildcards.

If you declare a method whose signature expect you to pass in List<HasWord>, then the only thing you can pass in is a List<HasWord>.

However, if said signature was List<? extends HasWord> then you could pass in a List<ChildOfHasWord> instead.

Note that there is a subtle difference between List<? extends HasWord> and List<? super HasWord>. As Joshua Bloch put it: PECS = producer-extends, consumer-super.

What this means is that if you are passing in a collection that your method pulls data out from (i.e. the collection is producing elements for your method to use), you should use extends. If you're passing in a collection that your method adds data to (i.e. the collection is consuming elements your method creates), it should use super.

This may sound confusing. However, you can see it in List's sort command (which is just a shortcut to the two-arg version of Collections.sort). Instead of taking a Comparator<T>, it actually takes a Comparator<? super T>. In this case, the Comparator is consuming the elements of the List in order to reorder the List itself.

Nginx Different Domains on Same IP

Your "listen" directives are wrong. See this page:

They should be

server {
    listen      80;
    root /var/www/domain1;

server {
    listen       80;
    root /var/www/domain2;

Note, I have only included the relevant lines. Everything else looked okay but I just deleted it for clarity. To test it you might want to try serving a text file from each server first before actually serving php. That's why I left the 'root' directive in there.

Difference between a virtual function and a pure virtual function

A pure virtual function is usually not (but can be) implemented in a base class and must be implemented in a leaf subclass.

You denote that fact by appending the "= 0" to the declaration, like this:

class AbstractBase
    virtual void PureVirtualFunction() = 0;

Then you cannot declare and instantiate a subclass without it implementing the pure virtual function:

class Derived : public AbstractBase
    virtual void PureVirtualFunction() override { }

By adding the override keyword, the compiler will ensure that there is a base class virtual function with the same signature.

JavaScript load a page on button click

The answers here work to open the page in the same browser window/tab.

However, I wanted the page to open in a new window/tab when they click a button. (tab/window decision depends on the user's browser setting)

So here is how it worked to open the page in new tab/window:

<button type="button" onclick="'', '_blank');">View Example Page</button>

It doesn't have to be a button, you can use anywhere. Notice the _blank that is used to open in new tab/window.

What is define([ , function ]) in JavaScript?

That's probably a requireJS module definition

Check here for more details

RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino and Node. Using a modular script loader like RequireJS will improve the speed and quality of your code.

What is the difference between an int and an Integer in Java and C#?

I'll add to the excellent answers given above, and talk about boxing and unboxing, and how this applies to Java (although C# has it too). I'll use just Java terminology because I am more au fait with that.

As the answers mentioned, int is just a number (called the unboxed type), whereas Integer is an object (which contains the number, hence a boxed type). In Java terms, that means (apart from not being able to call methods on int), you cannot store int or other non-object types in collections (List, Map, etc.). In order to store them, you must first box them up in its corresponding boxed type.

Java 5 onwards have something called auto-boxing and auto-unboxing which allow the boxing/unboxing to be done behind the scenes. Compare and contrast: Java 5 version:

Deque<Integer> queue;

void add(int n) {

int remove() {
    return queue.remove();

Java 1.4 or earlier (no generics either):

Deque queue;

void add(int n) {

int remove() {
    return ((Integer) queue.remove()).intValue();

It must be noted that despite the brevity in the Java 5 version, both versions generate identical bytecode. Thus, although auto-boxing and auto-unboxing are very convenient because you write less code, these operations do happens behind the scenes, with the same runtime costs, so you still have to be aware of their existence.

Hope this helps!

How to filter object array based on attributes?

You could do this pretty easily - there are probably many implementations you can choose from, but this is my basic idea (and there is probably some format where you can iterate over an object with jQuery, I just cant think of it right now):

function filter(collection, predicate)
    var result = new Array();
    var length = collection.length;

    for(var j = 0; j < length; j++)
        if(predicate(collection[j]) == true)

    return result;

And then you could invoke this function like so:

filter(json, function(element)
    if(element.price <= 1000 && element.sqft >= 500 && element.num_of_beds > 2 && element.num_of_baths > 2.5)
        return true;

    return false;

This way, you can invoke the filter based on whatever predicate you define, or even filter multiple times using smaller filters.

How to change a field name in JSON using Jackson

Be aware that there is org.codehaus.jackson.annotate.JsonProperty in Jackson 1.x and com.fasterxml.jackson.annotation.JsonProperty in Jackson 2.x. Check which ObjectMapper you are using (from which version), and make sure you use the proper annotation.

Add Bean Programmatically to Spring Web App Context

Here is a simple code:

ConfigurableListableBeanFactory beanFactory = ((ConfigurableApplicationContext) applicationContext).getBeanFactory();
beanFactory.registerSingleton(bean.getClass().getCanonicalName(), bean);

ImageMagick security policy 'PDF' blocking conversion

Adding to Stefan Seidel's answer.

Well, at least in Ubuntu 20.04.2 LTS or maybe in other versions you can't really edit the policy.xml file directly in a GUI way. Here is a terminal way to edit it.

  1. Open the policy.xml file in terminal by entering this command -

    sudo nano /etc/ImageMagick-6/policy.xml

  2. Now, directly edit the file in terminal, find <policy domain="coder" rights="none" pattern="PDF" /> and replace none with read|write as shown in the picture. Then press Ctrl+X to exit.

Edit in terminal

String.replaceAll single backslashes with double backslashes

To avoid this sort of trouble, you can use replace (which takes a plain string) instead of replaceAll (which takes a regular expression). You will still need to escape backslashes, but not in the wild ways required with regular expressions.

Removing Duplicate Values from ArrayList

In case you just need to remove the duplicates using only ArrayList, no other Collection classes, then:-

//list is the original arraylist containing the duplicates as well
List<String> uniqueList = new ArrayList<String>();
    for(int i=0;i<list.size();i++) {

Hope this helps!

Google Map API - Removing Markers

According to Google documentation they said that this is the best way to do it. First create this function to find out how many markers there are/

   function setMapOnAll(map1) {
    for (var i = 0; i < markers.length; i++) {

Next create another function to take away all these markers

 function clearMarker(){

Then create this final function to erase all the markers when ever this function is called upon.

 function delateMarkers(){
markers = []
//console.log(markers) This is just if you want to


Hope that helped good luck

If Browser is Internet Explorer: run an alternative script instead

Note that you can also determine in pure js in what browser you script is beeing executed through : window.navigator.userAgent

However, that's not a recommended way as it's configurable in the browser settings. More info available there:

Directory-tree listing in Python

A nice one liner to list only the files recursively. I used this in my package_data directive:

import os

[os.path.join(x[0],y) for x in os.walk('<some_directory>') for y in x[2]]

I know it's not the answer to the question, but may come in handy

Difference Between Schema / Database in MySQL

Depends on the database server. MySQL doesn't care, its basically the same thing.

Oracle, DB2, and other enterprise level database solutions make a distinction. Usually a schema is a collection of tables and a Database is a collection of schemas.

jQuery same click event for multiple elements

Add a comma separated list of classes like this :

jQuery(document).ready(function($) {

$('.class, .id').click(function() { 

//  Your code



"Register" an .exe so you can run it from any command line in Windows

In order to make it work

You need to modify the value of the environment variable with the name key Path, you can add as many paths as you want separating them with ;. The paths you give to it can't include the name of the executable file.

If you add a path to the variable Path all the excecutable files inside it can be called from cmd or porweshell by writing their name without .exe and these names are not case sensitive.

Here is how to create a system environment variable from a python script:

It is important to run it with administrator privileges in order to make it work. To better understand the code, just read the comments on it.

Tested on Windows 10

import winreg

# Create environment variable for call the program from shell, only works with compiled version
def environment_var(AppPath):

    # Point to the registry key of the system environment variables
    key = winreg.CreateKey(winreg.HKEY_LOCAL_MACHINE, r'System\CurrentControlSet\Control\Session Manager\Environment')

    def add_var(path):
        # Add the variable
        winreg.SetValueEx(key, 'Path', 0, winreg.REG_SZ, path)

        # Try to get the value of the Path variable
        allPaths = winreg.QueryValueEx(key, 'Path')[0]
    except Exception:
        # Create the Path variable if it doesn't exist

    # Get all the values of the existing paths

    # If the Path is empty, add the application path
    if Path == ['']:

    # Check if the application path is in the Path variable
    if AppPath not in Path:
        # Add the application path to the Path environment variable and add keep the others existing paths

# Only run this if the module is not imported by another
if __name__ == "__main__":
    # Run the function

You can find more information in the winreg documentation

Why functional languages?

Some thoughts:

  • The debate between FP and imperative programming (OO, structured, etc), has been raging since Lisp versus Fortran. I think you pose excellent questions but recognize that they are not especially new.
  • Part of the hoopla over FP is that we seem to be recognizing that concurrency is very difficult, and that locks and other mechanisms in OO (e.g. Java) are just one solution. FP offers a refreshing sea change with ideas such as Actors and the power of stateless computing. To those wrestling with OO, the landscape seems highly appealing.
  • Yes, schools teach FP. In fact, the University of Waterloo and others offer Scheme in first year classes (reference here).
  • Regarding the average programmer, I'm sure that the same arguments were given against C++ back in the early 1990s. And look what happened. If businesses can gain an advantage via a technology, you can bet that people will receive training.

This is not to say that it is a sure thing, or that there won't be a backlash in 3-5 years (as there always is). However, the trend towards FP has merit and is worth watching.

Is there a php echo/print equivalent in javascript

You can use

function echo(content) {  
    var e = document.createElement("p");
    e.innerHTML = content;
    document.currentScript.parentElement.replaceChild(document.currentScript, e);

which will replace the currently executing script who called the echo function with the text in the content argument.

How to add a TextView to LinearLayout in Android

You should use something similar to this for adding TextView to LinearLayout dynamically:

LinearLayout linearLayout = getActivity().findViewById(;

TextView valueTV = new TextView(context);
valueTV.setText("hallo hallo");
valueTV.setLayoutParams(new LinearLayout.LayoutParams(


getActivity() is used for inside Fragments, you can use context or anything similar per each instance you are inside.

Simple function to sort an array of objects

How about this?

var people = [
    name: 'a75',
    item1: false,
    item2: false
    name: 'z32',
    item1: true,
    item2: false
    name: 'e77',
    item1: false,
    item2: false

function sort_by_key(array, key)
 return array.sort(function(a, b)
  var x = a[key]; var y = b[key];
  return ((x < y) ? -1 : ((x > y) ? 1 : 0));

people = sort_by_key(people, 'name');

This allows you to specify the key by which you want to sort the array so that you are not limited to a hard-coded name sort. It will work to sort any array of objects that all share the property which is used as they key. I believe that is what you were looking for?

And here is a jsFiddle:

Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

You'd be surprised to find out that 80/20 is quite a commonly occurring ratio, often referred to as the Pareto principle. It's usually a safe bet if you use that ratio.

However, depending on the training/validation methodology you employ, the ratio may change. For example: if you use 10-fold cross validation, then you would end up with a validation set of 10% at each fold.

There has been some research into what is the proper ratio between the training set and the validation set:

The fraction of patterns reserved for the validation set should be inversely proportional to the square root of the number of free adjustable parameters.

In their conclusion they specify a formula:

Validation set (v) to training set (t) size ratio, v/t, scales like ln(N/h-max), where N is the number of families of recognizers and h-max is the largest complexity of those families.

What they mean by complexity is:

Each family of recognizer is characterized by its complexity, which may or may not be related to the VC-dimension, the description length, the number of adjustable parameters, or other measures of complexity.

Taking the first rule of thumb (i.e.validation set should be inversely proportional to the square root of the number of free adjustable parameters), you can conclude that if you have 32 adjustable parameters, the square root of 32 is ~5.65, the fraction should be 1/5.65 or 0.177 (v/t). Roughly 17.7% should be reserved for validation and 82.3% for training.

Adding multiple columns AFTER a specific column in MySQL

This works fine for me:


Circle line-segment collision detection algorithm?

Maybe there is another way to solve this problem using rotation of coordinate system.

Normally, if one segment is horizontal or vertical, which means parallel to x or y axis, it's quite easy to solve the intersection point since we already know one coordinate of the intersection, if any. The rest is obviously finding the other coordinate using circle's equation.

Inspired by this idea, we could apply coordinates system rotation to make one axis's direction coincide with segment's direction.

Let's take an example of circle x^2+y^2=1 and segment P1-P2 with P1(-1.5,0.5) and P2(-0.5,-0.5) in x-y system. And the following equations to remind you of the rotation principles, where theta is the angle anticlockwise, x'-y' is the system after rotation :

x' = x * cos(theta) + y * sin(theta)

y' = - x * sin(theta) + y * cos(theta)

and inversely

x = x' * cos(theta) - y' * sin(theta)

y = x' * sin(theta) + y' * cos(theta)

Considering the segment P1-P2 direction (45° in terms of -x), we could take theta=45°. Taking the second equations of rotation into circle's equation in x-y system : x^2+y^2=1 and after simple operations we get the 'same' equation in x'-y' system : x'^2+y'^2=1.

Segment endpoints become in x'-y' system using the first equations of rotation => P1(-sqrt(2)/2, sqrt(2)), P2(-sqrt(2)/2, 0).

Assuming the intersection as P. We have in x'-y' Px = -sqrt(2)/2. Using the new equation of circle, we get Py = +sqrt(2)/2. Converting P into original x-y system, we get finally P(-1,0).

To implement this numerically, we could firstly have a look at segment's direction : horizontal, vertical or not. If it belongs to the two first cases, it's simple like I said. If the last case, apply the algorithms above.

To juge if there is intersection, we could compare the solution with the endpoints coordinates, to see whether there is one root between them.

I believe this method could be also applied to other curves as long as we have its equation. The only weakness is that we should solve the equation in x'-y' system for the other coordinate, which might be difficult.

How to grant remote access permissions to mysql server for user?

This worked for me. But there was a strange problem that even I tryed first those it didnt affect. I updated phpmyadmin page and got it somehow working.

If you need access to local-xampp-mysql. You can go to xampp-shell -> opening command prompt.

Then mysql -uroot -p --port=3306 or mysql -uroot -p (if there is password set). After that you can grant those acces from mysql shell page (also can work from localhost/phpmyadmin).

Just adding these if somebody find this topic and having beginner problems.

PHP CSV string to array

If you need a name for the csv columns, you can use this method

 $example= array_map(function($v) {$column = str_getcsv($v, ";");return array("foo" => $column[0],"bar" => $column[1]);},file('file.csv'));

Which to use <div class="name"> or <div id="name">?

The object itself will not change. The main difference between these 2 keyword is the use:

  • The ID is usually single in the page
  • The class can have one or many occurences

In the CSS or Javascript files:

  • The ID will be accessed by the character #
  • The class will be accessed by the character .

python's re: return True if string contains regex pattern

Match objects are always true, and None is returned if there is no match. Just test for trueness.


>>> st = 'bar'
>>> m = re.match(r"ba[r|z|d]",st)
>>> if m:

Output = bar

If you want search functionality

>>> st = "bar"
>>> m ="ba[r|z|d]",st)
>>> if m is not None:

and if regexp not found than

>>> st = "hello"
>>> m ="ba[r|z|d]",st)
>>> if m:
... else:
...   print "no match"
no match

As @bukzor mentioned if st = foo bar than match will not work. So, its more appropriate to use

Can you write nested functions in JavaScript?

The following is nasty, but serves to demonstrate how you can treat functions like any other kind of object.

var foo = function () { alert('default function'); }

function pickAFunction(a_or_b) {
    var funcs = {
        a: function () {
        b: function () {
    foo = funcs[a_or_b];


Save text file UTF-8 encoded with VBA

I looked into the answer from Máta whose name hints at encoding qualifications and experience. The VBA docs say CreateTextFile(filename, [overwrite [, unicode]]) creates a file "as a Unicode or ASCII file. The value is True if the file is created as a Unicode file; False if it's created as an ASCII file. If omitted, an ASCII file is assumed." It's fine that a file stores unicode characters, but in what encoding? Unencoded unicode can't be represented in a file.

The VBA doc page for OpenTextFile(filename[, iomode[, create[, format]]]) offers a third option for the format:

  • TriStateDefault 2 "opens the file using the system default."
  • TriStateTrue 1 "opens the file as Unicode."
  • TriStateFalse 0 "opens the file as ASCII."

Máta passes -1 for this argument.

Judging from VB.NET documentation (not VBA but I think reflects realities about how underlying Windows OS represents unicode strings and echoes up into MS Office, I don't know) the system default is an encoding using 1 byte/unicode character using an ANSI code page for the locale. UnicodeEncoding is UTF-16. The docs also describe UTF-8 is also a "Unicode encoding," which makes sense to me. But I don't yet know how to specify UTF-8 for VBA output nor be confident that the data I write to disk with the OpenTextFile(,,,1) is UTF-16 encoded. Tamalek's post is helpful.

Merge DLL into EXE?

The command should be the following script:

ilmerge myExe.exe Dll1.dll /target:winexe /targetplatform:"v4,c:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\" /out:merged.exe /out:merged.exe

IOError: [Errno 22] invalid mode ('r') or filename: 'c:\\Python27\test.txt'

\t in a string marks an escape sequence for a tab character. For a literal \, use \\.

convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

If you don't need to handle raster files and PDF/PS/EPS through the same tool, don't loosen ImageMagick's security.

Instead, keep your defense in depth for your web applications intact, check that your Ghostscript has been patched for all known -dSAFER vulnerabilities and then invoke it directly.

gs -dSAFER -r300 -sDEVICE=png16m -o document-%03d.png document.pdf
  • -dSAFER opts you out of the legacy-compatibility "run Postscript will full permission to interact with the outside world as a turing-complete programming language" mode.
  • -r300 sets the desired DPI to 300 (the default is 72)
  • -sDEVICE specifies the output format (See the Devices section of the manual for other choices.)
  • -o is a shorthand for -dBATCH -dNOPAUSE -sOutputFile=
  • This section of the Ghostscript manual gives some example formats for for multi-file filename output but, for the actual syntax definition, it points you at the documentation for the C printf(3) function.

If you're rendering EPS files, add -dEPSCrop so it won't pad your output to page size and use -sDEVICE=pngalpha to get transparent backgrounds.

Disable developer mode extensions pop up in Chrome

The official way to disable the popup is this:

  1. Pack your extension: go to chrome://extensions, check Developer mode and click Pack extension

  2. Install the extension by dragging and dropping the .crx file into the chrome://extensions page.

You'll get an "Unsupported extensions disabled" popup if you try restarting Chrome at this point.

Then for Windows 7 or Windows 8:

  1. Download Chrome group policy templates here
  2. Copy [zip]\windows\admx\chrome.admx to c:\windows\policydefinitions
  3. Copy [zip]\windows\admx\[yourlanguage]\chrome.adml to c:\windows\policydefinitions\[yourlanguage]\chrome.adml (not c:\windows\[yourlanguage])
  4. In Chrome, go to the Extensions page: chrome://extensions
  5. Check Developer Mode
  6. Scroll down the list of disabled extensions and note the ID(s) of the extensions you want to enable.
  7. Click Start > Run, type gpedit.msc and hit enter.
  8. Click User Configuration > Administrative Templates > Google Chrome > Extensions
  9. Double click Configure extension installation whitelist policy
  10. Select Enabled, and click Show
  11. In the list, enter the ID(s) of the extensions you noted in Step 7
  12. Click OK and restart Chrome.

That's it!

EDIT: As of July 2018, this approach no longer works: it seems Google has stopped honouring the "whitelist".

EDIT 2: As of December 2018, this approach works in Chrome Version 69.0.3497.100 (Official Build) (64-bit):

  1. Temporarily enable Developer mode in chrome://extensions

  2. Uninstall the extension that causes the popup using the Load unpacked.

  3. Click on Pack extension, and find and select the folder containing the extension files. Don't enter the private key file if you don't have it.

  4. Click Pack extension. A .crx and .pem file will be created near the root directory of the extension. Install the extension using the .crx file and keep the .pem file safe.

  5. Copy the .crx installed extension ID to the whitelist and restart Chrome.

The popup should be gone.

What is ANSI format?

Just in case your PC is not a "Western" PC and you don't know which code page is used, you can have a look at this page: National Language Support (NLS) API Reference

[Microsoft removed this reference, take it form web-archive National Language Support (NLS) API Reference

Or you can query your registry:

C:\>reg query HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Nls\CodePage /f ACP

    ACP    REG_SZ    1252

End of search: 1 match(es) found.


Which Python memory profiler is recommended?

Muppy is (yet another) Memory Usage Profiler for Python. The focus of this toolset is laid on the identification of memory leaks.

Muppy tries to help developers to identity memory leaks of Python applications. It enables the tracking of memory usage during runtime and the identification of objects which are leaking. Additionally, tools are provided which allow to locate the source of not released objects.

How to filter Android logcat by application?

The log cat output can be filtered to only display messages from your package by using these arguments.

adb com.your.package:I *:s

Edit - I spoke to soon.

adb com.your.package:v

Special characters like @ and & in cURL POST data

I did this

~]$ export A=g

~]$ export B=!

~]$ export C=nger

   curl http://<>USERNAME<>1:$A$B$C@<>URL<>/<>PATH<>/

Java get last element of a collection

Iterables.getLast from Google Guava. It has some optimization for Lists and SortedSets too.

Print all day-dates between two dates

import datetime

begin =, 8, 15)
end =, 9, 15)

next_day = begin
while True:
    if next_day > end:
    print next_day
    next_day += datetime.timedelta(days=1)

What is the difference between for and foreach?

foreach syntax is quick and easy. for syntax is a little more complex, but is also more flexible.

foreach is useful when iterating all of the items in a collection. for is useful when iterating overall or a subset of items.

The foreach iteration variable which provides each collection item, is READ-ONLY, so we can't modify the items as they are iterated. Using the for syntax, we can modify the items as needed.

Bottom line- use foreach to quickly iterate all of the items in a collection. Use for to iterate a subset of the items of the collection or to modify the items as they are iterated.

How to switch between python 2.7 to python 3 from command line?

For Windows 7, I just rename the python.exe from the Python 3 folder to python3.exe and add the path into the environment variables. Using that, I can execute python and the script runs with Python 2.7 and when I do python3, it runs the script in Python 3.

To add Python 3 to the environment variables, follow these steps -

  1. Right Click on My Computer and go to Properties.
  2. Go to Advanced System Settings.
  3. Click on Environment Variables and edit PATH and add the path to your Python 3 installation directory.

For example,

enter image description here

Django REST Framework: adding additional field to ModelSerializer

I think SerializerMethodField is what you're looking for:

class FooSerializer(serializers.ModelSerializer):
  my_field = serializers.SerializerMethodField('is_named_bar')

  def is_named_bar(self, foo):
      return == "bar" 

  class Meta:
    model = Foo
    fields = ('id', 'name', 'my_field')

What MySQL data type should be used for Latitude/Longitude with 8 decimal places?

MySQL now has support for spatial data types since this question was asked. So the the current accepted answer is not wrong, but if you're looking for additional functionality like finding all points within a given polygon then use POINT data type.

Checkout the Mysql Docs on Geospatial data types and the spatial analysis functions

How to parse a CSV file using PHP

I been seeking the same thing without using some unsupported PHP class. Excel CSV dosn't always use the quote separators and escapes the quotes using "" because the algorithm was probably made back the 80's or something. After looking at several .csv parsers in the comments section on PHP.NET, I seen ones that even used callbacks or eval'd code and they either didnt work like needed or simply didnt work at all. So, I wrote my own routines for this and they work in the most basic PHP configuration. The array keys can either be numeric or named as the fields given in the header row. Hope this helps.

    function SW_ImplodeCSV(array $rows, $headerrow=true, $mode='EXCEL', $fmt='2D_FIELDNAME_ARRAY')
    // SW_ImplodeCSV - returns 2D array as string of csv(MS Excel .CSV supported)
    // AUTHOR: [email protected]
    // RELEASED: 9/21/13 BETA
      { $r=1; $row=array(); $fields=array(); $csv="";
        $escapes=array('\r', '\n', '\t', '\\', '\"');  //two byte escape codes
        $escapes2=array("\r", "\n", "\t", "\\", "\""); //actual code

        if($mode=='EXCEL')// escape code = ""
         { $delim=','; $enclos='"'; $rowbr="\r\n"; }
        else //mode=STANDARD all fields enclosed
           { $delim=','; $enclos='"'; $rowbr="\r\n"; }

          $csv=""; $i=-1; $i2=0; $imax=count($rows);

          while( $i < $imax )
            // get field names
            if($i == -1)
             { $row=$rows[0];
                { $i2=0; $i2max=count($row);
                  while( list($k, $v) = each($row) )
                   { $fields[$i2]=$k;
               else //if($fmt='2D_NUMBERED_ARRAY')
                { $i2=0; $i2max=(count($rows[0]));
                   { $fields[$i2]=$i2;

               if($headerrow==true) { $row=$fields; }
               else                 { $i=0; $row=$rows[0];}
             { $row=$rows[$i];

            $i2=0;  $i2max=count($row); 
            while($i2 < $i2max)// numeric loop (order really matters here)
            //while( list($k, $v) = each($row) )
             { if($i2 != 0) $csv=$csv.$delim;


               if($mode=='EXCEL') //EXCEL 2quote escapes
                    { $newv = '"'.(str_replace('"', '""', $v)).'"'; }
               else  //STANDARD
                    { $newv = '"'.(str_replace($escapes2, $escapes, $v)).'"'; }



         return $csv;

    function SW_ExplodeCSV($csv, $headerrow=true, $mode='EXCEL', $fmt='2D_FIELDNAME_ARRAY')
     { // SW_ExplodeCSV - parses CSV into 2D array(MS Excel .CSV supported)
       // AUTHOR: [email protected]
       // RELEASED: 9/21/13 BETA
       //SWMessage("SW_ExplodeCSV() - CALLED HERE -");
       $rows=array(); $row=array(); $fields=array();// rows = array of arrays

       //escape code = '\'
       $escapes=array('\r', '\n', '\t', '\\', '\"');  //two byte escape codes
       $escapes2=array("\r", "\n", "\t", "\\", "\""); //actual code

        {// escape code = ""
          $delim=','; $enclos='"'; $esc_enclos='""'; $rowbr="\r\n";
       else //mode=STANDARD 
        {// all fields enclosed
          $delim=','; $enclos='"'; $rowbr="\r\n";

       $indxf=0; $indxl=0; $encindxf=0; $encindxl=0; $enc=0; $enc1=0; $enc2=0; $brk1=0; $rowindxf=0; $rowindxl=0; $encflg=0;
       $rowcnt=0; $colcnt=0; $rowflg=0; $colflg=0; $cell="";
       $headerflg=0; $quotedflg=0;
       $i=0; $i2=0; $imax=strlen($csv);   

       while($indxf < $imax)
           //find first *possible* cell delimiters
           $indxl=strpos($csv, $delim, $indxf);  if($indxl===false) { $indxl=$imax; }
           $encindxf=strpos($csv, $enclos, $indxf); if($encindxf===false) { $encindxf=$imax; }//first open quote
           $rowindxl=strpos($csv, $rowbr, $indxf); if($rowindxl===false) { $rowindxl=$imax; }

            { $quoteflg=0; $encindxf=$imax; $encindxl=$imax;
              if($rowindxl<$indxl) { $indxl=$rowindxl; $rowflg=1; }
            { //find cell enclosure area (and real cell delimiter)
              while($enc<$indxl) //$enc = next open quote
               {// loop till unquoted delim. is found
                 $enc=strpos($csv, $enclos, $enc+1); if($enc===false) { $enc=$imax; }//close quote
                 $encindxl=$enc; //last close quote
                 $indxl=strpos($csv, $delim, $enc+1); if($indxl===false)  { $indxl=$imax; }//last delim.
                 $enc=strpos($csv, $enclos, $enc+1); if($enc===false) { $enc=$imax; }//open quote
                 if(($indxl==$imax)||($enc==$imax)) break;
              $rowindxl=strpos($csv, $rowbr, $enc+1); if($rowindxl===false) { $rowindxl=$imax; }
              if($rowindxl<$indxl) { $indxl=$rowindxl; $rowflg=1; }

            { //no enclosured content - take as is
              //get cell 
             // $cell=substr($csv, $indxf, ($indxl-$indxf)-1);
              $cell=substr($csv, $indxf, ($indxl-$indxf));
           else// if($rowindxl > $encindxf)
            { // cell enclosed

             //get cell - decode cell content
              $cell=substr($csv, $encindxf+1, ($encindxl-$encindxf)-1);

              if($mode=='EXCEL') //remove EXCEL 2quote escapes
                { $cell=str_replace($esc_enclos, $enclos, $cell);
              else //remove STANDARD esc. sceme
                { $cell=str_replace($escapes, $escapes2, $cell);

            {// read cell into array
              if( ($fmt=='2D_FIELDNAME_ARRAY') && ($headerflg==1) )
               { $row[$fields[$colcnt]]=$cell; }
              else if(($fmt=='2D_NUMBERED_ARRAY')||($headerflg==0))
               { $row[$colcnt]=$cell; } //$rows[$rowcnt][$colcnt] = $cell;

              $colcnt++; $colflg=0; $cell="";
            {// read row into big array
              if(($headerrow) && ($headerflg==0))
                {  $fields=$row;
                { $rows[$rowcnt]=$row;
               $colcnt=0; $rowflg=0; $cell="";

           //SWMessage("SW_ExplodeCSV() - colcnt = ".$colcnt."   rowcnt = ".$rowcnt."   indxf = ".$indxf."   indxl = ".$indxl."   rowindxf = ".$rowindxf);
           //if($i>20) break;

       return $rows;

...bob can now go back to his speadsheets

Context.startForegroundService() did not then call Service.startForeground()

Why this issue is happening is because Android framework can't guarantee your service get started within 5 second but on the other hand framework does have strict limit on foreground notification must be fired within 5 seconds, without checking if framework had tried to start the service.

This is definitely a framework issue, but not all developers facing this issue are doing their best:

  1. startForeground a notification must be in both onCreate and onStartCommand, because if your service is already created and somehow your activity is trying to start it again, onCreate won't be called.

  2. notification ID must not be 0 otherwise same crash will happen even it's not same reason.

  3. stopSelf must not be called before startForeground.

With all above 3 this issue can be reduced a bit but still not a fix, the real fix or let's say workaround is to downgrade your target sdk version to 25.

And note that most likely Android P will still carry this issue because Google refuses to even understand what is going on and does not believe this is their fault, read #36 and #56 for more information

Convert a dta file to csv without Stata software

SPSS can also read .dta files and export them to .csv, but that costs money. PSPP, an open source version of SPSS, which is rough, might also be able to read/export .dta files.

"Unmappable character for encoding UTF-8" error

For IntelliJ users, this is pretty easy once you find out what the original encoding was. You can select the encoding from the bottom right corner of your Window, you will be prompted with a dialog box saying:

The encoding you've chosen ('[encoding type]') may change the contents of '[Your file]'. Do you want to reload the file from disk or convert the text and save in the new encoding?

So if you happen to have a few characters saved in some odd encoding, what you should do is first select 'Reload' to load the file all in the encoding of the bad characters. For me this turned the ? characters into their proper value.

IntelliJ can tell if you most likely did not pick the right encoding and will warn you. Revert back and try again.

Once you can see the bad characters go away, change the encoding select box in the bottom right corner back to the format you originally intended (if you are Googling this error message, that will likely be UTF-8). This time select the 'Convert' button on the dialog.

For me, I needed to reload as 'windows-1252', then convert back to 'UTF-8'. The offending characters were single quotes (‘ and ’) likely pasted in from a Word doc (or e-mail) with the wrong encoding, and the above actions will convert them to UTF-8.

How to scanf only integer and repeat reading if the user enters non-numeric characters?

You could create a function that reads an integer between 1 and 23 or returns 0 if non-int


int getInt()
  int n = 0;
  char buffer[128];
  n = atoi(buffer); 
  return ( n > 23 || n < 1 ) ? 0 : n;

Dependent DLL is not getting copied to the build output folder in Visual Studio

Yes, you'll need to set Copy Local to true. However, I'm pretty sure you'll also need to reference that assembly from the main project and set Copy Local to true as well - it doesn't just get copied from a dependent assembly.

You can get to the Copy Local property by clicking on the assembly under References and pressing F4.

What is sys.maxint in Python 3?

An alternative is

import math

... math.inf ...

Delete all rows with timestamp older than x days

DELETE FROM on_search 

PHP max_input_vars

You can add it to php.ini and it should work - just tested it on PHP 5.3.6.

Add element to a list In Scala

You are using an immutable list. The operations on the List return a new List. The old List remains unchanged. This can be very useful if another class / method holds a reference to the original collection and is relying on it remaining unchanged. You can either use different named vals as in

val myList1 = 1.0 :: 5.5 :: Nil 
val myList2 = 2.2 :: 3.7 :: mylist1

or use a var as in

var myList = 1.0 :: 5.5 :: Nil 
myList :::= List(2.2, 3.7)

This is equivalent syntax for:

myList = myList.:::(List(2.2, 3.7))

Or you could use one of the mutable collections such as

val myList = scala.collection.mutable.MutableList(1.0, 5.5)
myList.++=(List(2.2, 3.7))

Not to be confused with the following that does not modify the original mutable List, but returns a new value:

myList.++:(List(2.2, 3.7))

However you should only use mutable collections in performance critical code. Immutable collections are much easier to reason about and use. One big advantage is that immutable List and scala.collection.immutable.Vector are Covariant. Don't worry if that doesn't mean anything to you yet. The advantage of it is you can use it without fully understanding it. Hence the collection you were using by default is actually scala.collection.immutable.List its just imported for you automatically.

I tend to use List as my default collection. From 2.12.6 Seq defaults to immutable Seq prior to this it defaulted to immutable.

What is a 'workspace' in Visual Studio Code?

I just installed Visual Studio Code v1.25.1. on a Windows 7 Professional SP1 machine. I wanted to understand workspaces in detail, so I spent a few hours figuring out how they work in this version of Visual Studio Code. I thought the results of my research might be of interest to the community.

First, workspaces are referred to by Microsoft in the Visual Studio Code documentation as "multi-root workspaces." In plain English that means "a multi-folder (A.K.A "root") work environment." A Visual Studio Code workspace is simply a collection of folders - any collection you desire, in any order you wish. The typical collection of folders constitutes a software development project. However, a folder collection could be used for anything else for which software code is being developed.

The mechanics behind how Visual Studio Code handles workspaces is a bit complicated. I think the quickest way to convey what I learned is by giving you a set of instructions that you can use to see how workspaces work on your computer. I am assuming that you are starting with a fresh install of Visual Studio Code v1.25.1. If you are using a production version of Visual Studio Code I don't recommend that you follow my instructions because you may lose some or all of your existing Visual Studio Code configuration! If you already have a test version of Visual Studio Code v1.25.1 installed, **and you are willing to lose any configuration that already exists, the following must be done to revert your Visual Studio Code to a fresh installation state:

Delete the following folder (if it exists):

  C:\Users\%username%\AppData\Roaming\Code\Workspaces (where "%username%" is the name of the currently logged-on user)

You will be adding folders to Visual Studio Code to create a new workspace. If any of the folders you intend to use to create this new workspace have previously been used with Visual Studio Code, please delete the ".vscode" subfolder (if it exists) within each of the folders that will be used to create the new workspace.

Launch Visual Studio Code. If the Welcome page is displayed, close it. Do the same for the Panel (a horizontal pane) if it is displayed. If you received a message that Git isn't installed click "Remind me later." If displayed, also close the "Untitled" code page that was launched as the default code page. If the Explorer pane is not displayed click "View" on the main menu then click "Explorer" to display the Explorer pane. Inside the Explorer pane you should see three (3) View headers - Open Editors, No Folder Opened, and Outline (located at the very bottom of the Explorer pane). Make sure that, at a minimum, the open editors and no folder opened view headers are displayed.

Visual Studio Code displays a button that reads "Open Folder." Click this button and select a folder of your choice. Visual Studio Code will refresh and the name of your selected folder will have replaced the "No Folder Opened" View name. Any folders and files that exist within your selected folder will be displayed beneath the View name.

Now open the Visual Studio Code Preferences Settings file. There are many ways to do this. I'll use the easiest to remember which is menu FilePreferencesSettings. The Settings file is displayed in two columns. The left column is a read-only listing of the default values for every Visual Studio Code feature. The right column is used to list the three (3) types of user settings. At this point in your test only two user settings will be listed - User Settings and Workspace Settings. The User Settings is displayed by default. This displays the contents of your User Settings .json file. To find out where this file is located, simply hover your mouse over the "User Settings" listing that appears under the OPEN EDITORS View in Explorer. This listing in the OPEN EDITORS View is automatically selected when the "User Settings" option in the right column is selected. The path should be:


This settings.json file is where the User Settings for Visual Studio Code are stored.

Now click the Workspace Settings option in the right column of the Preferences listing. When you do this, a subfolder named ".vscode" is automatically created in the folder you added to Explore a few steps ago. Look at the listing of your folder in Explorer to confirm that the .vscode subfolder has been added. Inside the new .vscode subfolder is another settings.json file. This file contains the workspace settings for the folder you added to Explorer a few steps ago.

At this point you have a single folder whose User Settings are stored at:


and whose Workspace Settings are stored at:


This is the configuration when a single folder is added to a new installation of Visual Studio Code. Things get messy when we add a second (or greater) folder. That's because we are changing Visual Studio Code's User Settings and Workspace Settings to accommodate multiple folders. In a single-folder environment only two settings.json files are needed as listed above. But in a multi-folder environment a .vscode subfolder is created in each folder added to Explorer and a new file, "workspaces.json," is created to manage the multi-folder environment. The new "workspaces.json" file is created at:


The "%workspaces_id%" is a folder with a unique all-number name.

In the Preferences right column there now appears three user setting options - User Settings, Workspace Settings, and Folder Settings. The function of User Settings remains the same as for a single-folder environment. However, the settings file behind the Workspace Settings has been changed from the settings.json file in the single folder's .vscode subfolder to the workspaces.json file located at the workspaces.json file path shown above. The settings.json file located in each folder's .vscode subfolder is now controlled by a third user setting, Folder Options. This is a drop-down selection list that allows for the management of each folder's settings.json file located in each folder's .vscode subfolder. Please note: the .vscode subfolder will not be created in newly-added explorer folders until the newly-added folder has been selected at least once in the folder options user setting.

Notice that the Explorer single folder name has bee changed to "UNTITLED (WORKSPACE)." This indicates the following:

  1. A multi-folder workspace has been created with the name "UNTITLED (WORKSPACE)
  2. The workspace is named "UNTITLED (WORKSPACE)" to communicate that the workspace has not yet been saved as a separate, unique, workspace file
  3. The UNTITLED (WORKSPACE) workspace can have folders added to it and removed from it but it will function as the ONLY workspace environment for Visual Studio Code

The full functionality of Visual Studio Code workspaces is only realized when a workspace is saved as a file that can be reloaded as needed. This provides the capability to create unique multi-folder workspaces (e.g., projects) and save them as files for later use! To do this select menu FileSave Workspace As from the main menu and save the current workspace configuration as a unique workspace file. If you need to create a workspace "from scratch," first save your current workspace configuration (if needed) then right-click each Explorer folder name and click "Remove Folder from Workspace." When all folders have been removed from the workspace, add the folders you require for your new workspace. When you finish adding new folders, simply save the new workspace as a new workspace file.

An important note - Visual Studio Code doesn't "revert" to single-folder mode when only one folder remains in Explorer or when all folders have been removed from Explorer when creating a new workspace "from scratch." The multi-folder workspace configuration that utilizes three user preferences remains in effect. This means that unless you follow the instructions at the beginning of this post, Visual Studio Code can never be returned to a single-folder mode of operation - it will always remain in multi-folder workspace mode.

How to install mcrypt extension in xampp

First, you should download the suitable version for your system from here:

Then, you should copy php_mcrypt.dll to ../xampp/php/ext/ and enable the extension by adding extension=mcrypt to your xampp/php/php.ini file.

Cross field validation with Hibernate Validator (JSR 303)

I suggest you another possible solution. Perhaps less elegant, but easier!

public class MyBean {
  @Size(min=6, max=50)
  private String pass;

  private String passVerify;

  @AssertTrue(message="passVerify field should be equal than pass field")
  private boolean isValid() {
    return this.pass.equals(this.passVerify);

The isValid method is invoked by the validator automatically.

How do you determine what technology a website is built on?

Some people might even deliberately obscure the technology they use. After all, it wouldn't take me long to tweak apache so that ".asp" actually ran perl scripts and put "powered by Microsoft IIS" into my footer despite the fact I used MySQL.

That way you'd spend all your time trying to hack my site using vulnerabilities it doesn't actually have.

SQLAlchemy insert or update example

assuming certain column names...


newToner = Toner(toner_id = 1,
                    toner_color = 'blue',
                    toner_hex = '#0F85FF')


INSERT multiple

newToner1 = Toner(toner_id = 1,
                    toner_color = 'blue',
                    toner_hex = '#0F85FF')

newToner2 = Toner(toner_id = 2,
                    toner_color = 'red',
                    toner_hex = '#F01731')

dbsession.add_all([newToner1, newToner2])   


q = dbsession.query(Toner)
q = q.filter(Toner.toner_id==1)
record =
record.toner_color = 'Azure Radiance'


or using a fancy one-liner using MERGE

record = dbsession.merge(Toner( **kwargs))

IDENTITY_INSERT is set to OFF - How to turn it ON?

Add this line above you Query


Set mouse focus and move cursor to end of input using jQuery

I have found the same thing as suggested above by a few folks. If you focus() first, then push the val() into the input, the cursor will get positioned to the end of the input value in Firefox,Chrome and IE. If you push the val() into the input field first, Firefox and Chrome position the cursor at the end, but IE positions it to the front when you focus().


should do the trick (it always has for me anyway).

Is there a command line utility for rendering GitHub flavored Markdown?

Building on this comment I wrote a one-liner to hit the Github Markdown API using curl and jq.

Paste this bash function onto the command line or into your ~/.bash_profile:

    HTMLFILE="$(mktemp -u).html"
    cat "$1" | \
      jq --slurp --raw-input '{"text": "\(.)", "mode": "markdown"}' | \
      curl -s --data @- > "$HTMLFILE"
    echo $HTMLFILE
    open "$HTMLFILE"

And then to see the rendered HTML in-browser run:


Replace open "$HTMLFILE" with lynx "$HTMLFILE" if you need a pure terminal solution.

a = open("file", "r"); a.readline() output without \n

That would be:


If you want to strip space from each and every line, you might consider instead:

This will give you a list of lines, without the line end characters.

Error 'LINK : fatal error LNK1123: failure during conversion to COFF: file invalid or corrupt' after installing Visual Studio 2012 Release Preview

Reinstalling CMake worked for me. The new copy of CMake figured out that it should use Visual Studio 11 instead of 10.

How to print_r $_POST array?

$_POST is already an array. Try this:

foreach ($_POST as $key => $value) {
    echo "<p>".$key."</p>";
    echo "<p>".$value."</p>";
    echo "<hr />";

IE 8: background-size fix

Also i have found another useful link. It is a background hack used like this

.selector { background-size: cover; -ms-behavior: url(/; }

DB2 Date format

This isn't straightforward, but


returns the current date in yyyy-mm-dd format. You would have to substring and concatenate the result to get yyyymmdd.


Pip install - Python 2.7 - Windows 7

you have to first download the and then run the command :


Set Session variable using javascript in PHP

In JavaScript:


In session_write.php file:


if (isset($_GET['session_name'])) {$_SESSION['session_name'] = $_GET['session_name'];}


<div id='div_session_write'> </div>

Python recursive folder read

use os.path.join() to construct your paths - It's neater:

import os
import sys
rootdir = sys.argv[1]
for root, subFolders, files in os.walk(rootdir):
    for folder in subFolders:
        outfileName = os.path.join(root,folder,"py-outfile.txt")
        folderOut = open( outfileName, 'w' )
        print "outfileName is " + outfileName
        for file in files:
            filePath = os.path.join(root,file)
            toWrite = open( filePath).read()
            print "Writing '" + toWrite + "' to" + filePath
            folderOut.write( toWrite )

How can I create an MSI setup?

In my opinion you should use Wix#, which nicely hides most of the complexity of building an MSI installation pacakge.

It allows you to perform all possible kinds of customization using a more easier language compared to WiX.

Converting a String array into an int Array in java

private void processLine(String[] strings) {
    Integer[] intarray=new Integer[strings.length];
    for(int i=0;i<strings.length;i++) {
    for(Integer temp:intarray) {
        System.out.println("convert int array from String"+temp);

Combine or merge JSON on node.js without jQuery

It can easy be done using Object.assign() method -

 var object1 = {name: "John"};
 var object2 = {location: "San Jose"};
 var object3 = Object.assign(object1,object2);

now object3 is { name: 'John', location: 'San Jose' }

Maven does not find JUnit tests to run

I struggle with this problem. In my case I wasn't importing the right @Test annotation.

1) Check if the @Test is from org.junit.jupiter.api.Test (if you are using Junit 5).

2) With Junit5 instead of @RunWith(SpringRunner.class), use @ExtendWith(SpringExtension.class)

import org.junit.jupiter.api.Test;

@TestPropertySource(locations = "")    
public class CotacaoTest {
    public void testXXX() {


How to run an android app in background?

You can probably start a Service here if you want your Application to run in Background. This is what Service in Android are used for - running in background and doing longtime operations.


You can use START_STICKY to make your Service running continuously.

public int onStartCommand(Intent intent, int flags, int startId) {
    // We want this service to continue running until it is explicitly
    // stopped, so return sticky.
    return START_STICKY;

How to read from stdin with fgets()?

If you want to concatenate the input, then replace printf("%s\n", buffer); with strcat(big_buffer, buffer);. Also create and initialize the big buffer at the beginning: char *big_buffer = new char[BIG_BUFFERSIZE]; big_buffer[0] = '\0';. You should also prevent a buffer overrun by verifying the current buffer length plus the new buffer length does not exceed the limit: if ((strlen(big_buffer) + strlen(buffer)) < BIG_BUFFERSIZE). The modified program would look like this:

#include <stdio.h>
#include <string.h>

#define BUFFERSIZE 10
#define BIG_BUFFERSIZE 1024

int main (int argc, char *argv[])
    char buffer[BUFFERSIZE];
    char *big_buffer = new char[BIG_BUFFERSIZE];
    big_buffer[0] = '\0';
    printf("Enter a message: \n");
    while(fgets(buffer, BUFFERSIZE , stdin) != NULL)
        if ((strlen(big_buffer) + strlen(buffer)) < BIG_BUFFERSIZE)
            strcat(big_buffer, buffer);
    return 0;

Disable a Button

For those who Googled "disable a button" but may have more nuanced use cases:

Disable with visual effect: As others have said, this will prevent the button from being pressed and the system will automatically make it look disabled:

yourButton.isEnabled = false 

Disable without visual effect: Are you using a button in a case where it should look normal but not behave likes button by reacting to touches? Try this!

yourButton.userInteractionEnabled = false

Hide without disabling: This approach hides the button without disabling it (invisible but can still be tapped):

 yourButton.alpha = 0.0

Remove: This will remove the view entirely:


Tap something behind a button: Have two buttons stacked and you want the top button to temporarily act like it's not there? If you won't need the top button again, remove it. If you will need it again, try condensing its height or width to 0!

jQuery trigger event when click outside the element

if you have child elements like dropdown menus

$('html').click(function(e) {
  //if clicked element is not your element and parents aren't your div
  if ( != 'your-div-id' && $('#your-div-id').length == 0) {
    //do stuff

Get current cursor position in a textbox

Here's one possible method.

function isMouseInBox(e) {
  var textbox = document.getElementById('textbox');

  // Box position & sizes
  var boxX = textbox.offsetLeft;
  var boxY = textbox.offsetTop;
  var boxWidth = textbox.offsetWidth;
  var boxHeight = textbox.offsetHeight;

  // Mouse position comes from the 'mousemove' event
  var mouseX = e.pageX;
  var mouseY = e.pageY;
  if(mouseX>=boxX && mouseX<=boxX+boxWidth) {
    if(mouseY>=boxY && mouseY<=boxY+boxHeight){
       // Mouse is in the box
       return true;

document.addEventListener('mousemove', function(e){

JQuery .each() backwards

Needed to do a reverse on $.each so i used Vinay idea:

//jQuery.each(collection, callback) =>
$.each($(collection).get().reverse(), callback func() {});

worked nicely, thanks

How to check if string contains Latin characters only?

You can use regex:


The i makes the regex case-insensitive. You could also do:


Facebook share link - can you customize the message body text?

Facebook does not allow you to change the "What's on your mind?" text box, unless of course you're developing an application for use on Facebook.

In Unix, how do you remove everything in the current directory and below it?

make sure you are in the correct directory

rm -rf *

Android Preventing Double Click On A Button

Click events queue up when the UI thread is blocked. On a button click event, change to a background task as soon as possible to avoid click events queueing up behind each other.

Declare a volatile boolean or lock inside the activity class:

private volatile boolean saving = false;

Create a Button with an onClickListener that is gated by saving and start a background task to do the work:

saveButton.setOnClickListener(new View.OnClickListener() {

    public void onClick(View view) {
        if (!saving) {
            saving = true;
            new SaveAsyncTask().execute();

Create an inner SaveAsyncTask class to do the work in the background:

class SaveAsyncTask extends AsyncTask {

    protected Object doInBackground(Object[] objects) {
        // Do something here, simulate a 3 second task
        saving = false;
        return null;

ImportError: Couldn't import Django

I had same problem, I installed all dependencies with root access :

In your case:

sudo pip install django

In my case, I had all dependencies in requirements.txt, So:

sudo pip3 install -r requirements.txt

C++11 introduced a standardized memory model. What does it mean? And how is it going to affect C++ programming?

I will just give the analogy with which I understand memory consistency models (or memory models, for short). It is inspired by Leslie Lamport's seminal paper "Time, Clocks, and the Ordering of Events in a Distributed System". The analogy is apt and has fundamental significance, but may be overkill for many people. However, I hope it provides a mental image (a pictorial representation) that facilitates reasoning about memory consistency models.

Let’s view the histories of all memory locations in a space-time diagram in which the horizontal axis represents the address space (i.e., each memory location is represented by a point on that axis) and the vertical axis represents time (we will see that, in general, there is not a universal notion of time). The history of values held by each memory location is, therefore, represented by a vertical column at that memory address. Each value change is due to one of the threads writing a new value to that location. By a memory image, we will mean the aggregate/combination of values of all memory locations observable at a particular time by a particular thread.

Quoting from "A Primer on Memory Consistency and Cache Coherence"

The intuitive (and most restrictive) memory model is sequential consistency (SC) in which a multithreaded execution should look like an interleaving of the sequential executions of each constituent thread, as if the threads were time-multiplexed on a single-core processor.

That global memory order can vary from one run of the program to another and may not be known beforehand. The characteristic feature of SC is the set of horizontal slices in the address-space-time diagram representing planes of simultaneity (i.e., memory images). On a given plane, all of its events (or memory values) are simultaneous. There is a notion of Absolute Time, in which all threads agree on which memory values are simultaneous. In SC, at every time instant, there is only one memory image shared by all threads. That's, at every instant of time, all processors agree on the memory image (i.e., the aggregate content of memory). Not only does this imply that all threads view the same sequence of values for all memory locations, but also that all processors observe the same combinations of values of all variables. This is the same as saying all memory operations (on all memory locations) are observed in the same total order by all threads.

In relaxed memory models, each thread will slice up address-space-time in its own way, the only restriction being that slices of each thread shall not cross each other because all threads must agree on the history of every individual memory location (of course, slices of different threads may, and will, cross each other). There is no universal way to slice it up (no privileged foliation of address-space-time). Slices do not have to be planar (or linear). They can be curved and this is what can make a thread read values written by another thread out of the order they were written in. Histories of different memory locations may slide (or get stretched) arbitrarily relative to each other when viewed by any particular thread. Each thread will have a different sense of which events (or, equivalently, memory values) are simultaneous. The set of events (or memory values) that are simultaneous to one thread are not simultaneous to another. Thus, in a relaxed memory model, all threads still observe the same history (i.e., sequence of values) for each memory location. But they may observe different memory images (i.e., combinations of values of all memory locations). Even if two different memory locations are written by the same thread in sequence, the two newly written values may be observed in different order by other threads.

[Picture from Wikipedia] Picture from Wikipedia

Readers familiar with Einstein’s Special Theory of Relativity will notice what I am alluding to. Translating Minkowski’s words into the memory models realm: address space and time are shadows of address-space-time. In this case, each observer (i.e., thread) will project shadows of events (i.e., memory stores/loads) onto his own world-line (i.e., his time axis) and his own plane of simultaneity (his address-space axis). Threads in the C++11 memory model correspond to observers that are moving relative to each other in special relativity. Sequential consistency corresponds to the Galilean space-time (i.e., all observers agree on one absolute order of events and a global sense of simultaneity).

The resemblance between memory models and special relativity stems from the fact that both define a partially-ordered set of events, often called a causal set. Some events (i.e., memory stores) can affect (but not be affected by) other events. A C++11 thread (or observer in physics) is no more than a chain (i.e., a totally ordered set) of events (e.g., memory loads and stores to possibly different addresses).

In relativity, some order is restored to the seemingly chaotic picture of partially ordered events, since the only temporal ordering that all observers agree on is the ordering among “timelike” events (i.e., those events that are in principle connectible by any particle going slower than the speed of light in a vacuum). Only the timelike related events are invariantly ordered. Time in Physics, Craig Callender.

In C++11 memory model, a similar mechanism (the acquire-release consistency model) is used to establish these local causality relations.

To provide a definition of memory consistency and a motivation for abandoning SC, I will quote from "A Primer on Memory Consistency and Cache Coherence"

For a shared memory machine, the memory consistency model defines the architecturally visible behavior of its memory system. The correctness criterion for a single processor core partitions behavior between “one correct result” and “many incorrect alternatives”. This is because the processor’s architecture mandates that the execution of a thread transforms a given input state into a single well-defined output state, even on an out-of-order core. Shared memory consistency models, however, concern the loads and stores of multiple threads and usually allow many correct executions while disallowing many (more) incorrect ones. The possibility of multiple correct executions is due to the ISA allowing multiple threads to execute concurrently, often with many possible legal interleavings of instructions from different threads.

Relaxed or weak memory consistency models are motivated by the fact that most memory orderings in strong models are unnecessary. If a thread updates ten data items and then a synchronization flag, programmers usually do not care if the data items are updated in order with respect to each other but only that all data items are updated before the flag is updated (usually implemented using FENCE instructions). Relaxed models seek to capture this increased ordering flexibility and preserve only the orders that programmers “require” to get both higher performance and correctness of SC. For example, in certain architectures, FIFO write buffers are used by each core to hold the results of committed (retired) stores before writing the results to the caches. This optimization enhances performance but violates SC. The write buffer hides the latency of servicing a store miss. Because stores are common, being able to avoid stalling on most of them is an important benefit. For a single-core processor, a write buffer can be made architecturally invisible by ensuring that a load to address A returns the value of the most recent store to A even if one or more stores to A are in the write buffer. This is typically done by either bypassing the value of the most recent store to A to the load from A, where “most recent” is determined by program order, or by stalling a load of A if a store to A is in the write buffer. When multiple cores are used, each will have its own bypassing write buffer. Without write buffers, the hardware is SC, but with write buffers, it is not, making write buffers architecturally visible in a multicore processor.

Store-store reordering may happen if a core has a non-FIFO write buffer that lets stores depart in a different order than the order in which they entered. This might occur if the first store misses in the cache while the second hits or if the second store can coalesce with an earlier store (i.e., before the first store). Load-load reordering may also happen on dynamically-scheduled cores that execute instructions out of program order. That can behave the same as reordering stores on another core (Can you come up with an example interleaving between two threads?). Reordering an earlier load with a later store (a load-store reordering) can cause many incorrect behaviors, such as loading a value after releasing the lock that protects it (if the store is the unlock operation). Note that store-load reorderings may also arise due to local bypassing in the commonly implemented FIFO write buffer, even with a core that executes all instructions in program order.

Because cache coherence and memory consistency are sometimes confused, it is instructive to also have this quote:

Unlike consistency, cache coherence is neither visible to software nor required. Coherence seeks to make the caches of a shared-memory system as functionally invisible as the caches in a single-core system. Correct coherence ensures that a programmer cannot determine whether and where a system has caches by analyzing the results of loads and stores. This is because correct coherence ensures that the caches never enable new or different functional behavior (programmers may still be able to infer likely cache structure using timing information). The main purpose of cache coherence protocols is maintaining the single-writer-multiple-readers (SWMR) invariant for every memory location. An important distinction between coherence and consistency is that coherence is specified on a per-memory location basis, whereas consistency is specified with respect to all memory locations.

Continuing with our mental picture, the SWMR invariant corresponds to the physical requirement that there be at most one particle located at any one location but there can be an unlimited number of observers of any location.

How to run a command in the background and get no output?

Run in a subshell to remove notifications and close STDOUT and STDERR:

(&>/dev/null &)

Error handling in Bash

Another consideration is the exit code to return. Just "1" is pretty standard, although there are a handful of reserved exit codes that bash itself uses, and that same page argues that user-defined codes should be in the range 64-113 to conform to C/C++ standards.

You might also consider the bit vector approach that mount uses for its exit codes:

 0  success
 1  incorrect invocation or permissions
 2  system error (out of memory, cannot fork, no more loop devices)
 4  internal mount bug or missing nfs support in mount
 8  user interrupt
16  problems writing or locking /etc/mtab
32  mount failure
64  some mount succeeded

OR-ing the codes together allows your script to signal multiple simultaneous errors.

How can I disable the default console handler, while using the java logging API?

The default console handler is attached to the root logger, which is a parent of all other loggers including yours. So I see two ways to solve your problem:

If this is only affects this particular class of yours, the simplest solution would be to disable passing the logs up to the parent logger:


If you want to change this behaviour for your whole app, you could remove the default console handler from the root logger altogether before adding your own handlers:

Logger globalLogger = Logger.getLogger("global");
Handler[] handlers = globalLogger.getHandlers();
for(Handler handler : handlers) {

Note: if you want to use the same log handlers in other classes too, the best way is to move the log configuration into a config file in the long run.

Get Specific Columns Using “With()” Function in Laravel Eloquent

You can do it like this since Laravel 5.5:


Care for the id field and foreign keys as stated in the docs:

When using this feature, you should always include the id column and any relevant foreign key columns in the list of columns you wish to retrieve.

For example, if the user belongs to a team and has a team_id as a foreign key column, then $post->user->team is empty if you don't specifiy team_id


Adding one day to a date

Simplest solution:

$date = new DateTime('+1 day');
echo $date->format('Y-m-d H:i:s');

Runtime vs. Compile time

Compile-time: the time period in which you, the developer, are compiling your code.

Run-time: the time period which a user is running your piece of software.

Do you need any clearer definition?

How to write multiple conditions in with "else if"

ifdef $(HAVE_CLIENT)
libtest_LIBS = \
ifdef $(HAVE_SERVER)
libtest_LIBS = \
libtest_LIBS = 

NOTE: DO NOT indent the if then it don't work!

How to import classes defined in

Add something like this to lib/

from .helperclass import Helper

now you can import it directly:

from lib import Helper

How to create directory automatically on SD card

Make sure external storage is present:

private boolean isExternalStoragePresent() {

        boolean mExternalStorageAvailable = false;
        boolean mExternalStorageWriteable = false;
        String state = Environment.getExternalStorageState();

        if (Environment.MEDIA_MOUNTED.equals(state)) {
            // We can read and write the media
            mExternalStorageAvailable = mExternalStorageWriteable = true;
        } else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
            // We can only read the media
            mExternalStorageAvailable = true;
            mExternalStorageWriteable = false;
        } else {
            // Something else is wrong. It may be one of many other states, but
            // all we need
            // to know is we can neither read nor write
            mExternalStorageAvailable = mExternalStorageWriteable = false;
        if (!((mExternalStorageAvailable) && (mExternalStorageWriteable))) {
            Toast.makeText(context, "SD card not present", Toast.LENGTH_LONG)

        return (mExternalStorageAvailable) && (mExternalStorageWriteable);

How to format time since xxx e.g. “4 minutes ago” similar to Stack Exchange sites

function timeSince(date) {

  var seconds = Math.floor((new Date() - date) / 1000);

  var interval = seconds / 31536000;

  if (interval > 1) {
    return Math.floor(interval) + " years";
  interval = seconds / 2592000;
  if (interval > 1) {
    return Math.floor(interval) + " months";
  interval = seconds / 86400;
  if (interval > 1) {
    return Math.floor(interval) + " days";
  interval = seconds / 3600;
  if (interval > 1) {
    return Math.floor(interval) + " hours";
  interval = seconds / 60;
  if (interval > 1) {
    return Math.floor(interval) + " minutes";
  return Math.floor(seconds) + " seconds";
var aDay = 24*60*60*1000;
console.log(timeSince(new Date(;
console.log(timeSince(new Date(*2)));

Select row and element in awk

To expand on Dennis's answer, use awk's -v option to pass the i and j values:

# print the j'th field of the i'th line
awk -v i=5 -v j=3 'FNR == i {print $j}'

Use HTML5 to resize an image before upload

If some of you, like me, encounter orientation problems I have combined the solutions here with a exif orientation fix

How to get the unix timestamp in C#

The simple code that I am using:

public static long CurrentTimestamp()
   return (long)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds * 1000);

This code is giving unix timestamp, total milliseconds from 1970-01-01 to now.

How does Python manage int and long?

This PEP should help.

Bottom line is that you really shouldn't have to worry about it in python versions > 2.4

How to get css background color on <tr> tag to span entire row

Firefox and Chrome are different
Chrome ignores the TR's background-color

<tr style="background-color:#F00">
     <td style="background-color:#FFF; border-radius:20px">

In FF the TD gets red corners, in Chrome not

How to set value to variable using 'execute' in t-sql?

-- =============================================
-- Author:      Andrew Foster
-- Create date: 28 Mar 2013
-- Description: Allows the dynamic pull of any column value up to 255 chars from regUsers table
-- =============================================
ALTER PROCEDURE dbo.PullTableColumn
    @columnName varchar(255),
    @id int
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.

    DECLARE @columnVal TABLE (columnVal nvarchar(255));

    DECLARE @sql nvarchar(max);
    SET @sql = 'SELECT ' + @columnName + ' FROM regUsers WHERE id=' + CAST(@id AS varchar(10));
    INSERT @columnVal EXEC sp_executesql @sql;

    SELECT * FROM @columnVal;

Can the Android layout folder contain subfolders?

Top answers have several disadvantages: you have to add new layout paths, AS places new resources to res\layouts folder instead of res\values.

Combining several answers I wrote similar:

sourceSets {
    main {
        res.srcDirs =

I made folders with this article: In order to create subfolders you should use this menu: New > Folder > Res Folder.


After a couple of weeks I found that changes in resources are not noticed by Android Studio. So, some weird bugs appear. For instance, layouts continue to show old sizes, margins. Sometimes AS doesn't find new XML-files (especially during run-time). Sometimes it mixes view ids (references to another XML-file). It's often required to press Build > Clean Project or Build > Rebuild Project. Read Rebuild required after changing xml layout files in Android Studio.

Fit cell width to content

Simple :

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

How does += (plus equal) work?

As everyone said above

var str = "foo"
str += " bar"
console.log(str) //will now give you "foo bar"

Check this out as well

How do I remove carriage returns with Ruby?

modified_string = string.gsub(/\s+/, ' ').strip

SELECT query with CASE condition and SUM()

Select SUM(CASE When CPayment='Cash' Then CAmount Else 0 End ) as CashPaymentAmount,
       SUM(CASE When CPayment='Check' Then CAmount Else 0 End ) as CheckPaymentAmount
from TableOrderPayment
Where ( CPayment='Cash' Or CPayment='Check' ) AND CDate<=SYSDATETIME() and CStatus='Active';

ansible: lineinfile for several lines?

It's not ideal, but you're allowed multiple calls to lineinfile. Using that with insert_after, you can get the result you want:

- name: Set first line at EOF (1/3)
  lineinfile: dest=/path/to/file regexp="^string 1" line="string 1"
- name: Set second line after first (2/3)
  lineinfile: dest=/path/to/file regexp="^string 2" line="string 2" insertafter="^string 1"
- name: Set third line after second (3/3)
  lineinfile: dest=/path/to/file regexp="^string 3" line="string 3" insertafter="^string 2"

How to assign name for a screen?

To start a new session

screen -S your_session_name

To rename an existing session

Ctrl+a, : sessionname YOUR_SESSION_NAME Enter

You must be inside the session

React-router v4 this.props.history.push(...) not working

You can get access to the history object's properties and the closest 's match via the withRouter higher-order component. withRouter will pass updated match, location, and history props to the wrapped component whenever it renders.

import React, { Component } from 'react'
import { withRouter } from 'react-router'; 
// you can also import "withRouter" from 'react-router-dom';

class Example extends Component {
    render() {
        const { match, location, history } = this.props
        return (
                <div>You are now at {location.pathname}</div>
                <button onClick={() => history.push('/')}>{'Home'}</button>

export default withRouter(Example)

C# difference between == and Equals()

I am a bit confused here. If the runtime type of Content is of type string, then both == and Equals should return true. However, since this does not appear to be the case, then runtime type of Content is not string and calling Equals on it is doing a referential equality and this explains why Equals("Energy Attack") fails. However, in the second case, the decision as to which overloaded == static operator should be called is made at compile time and this decision appears to be ==(string,string). this suggests to me that Content provides an implicit conversion to string.

Find row number of matching value

For your first method change ws.Range("A") to ws.Range("A:A") which will search the entirety of column a, like so:

Sub Find_Bingo()

        Dim wb As Workbook
        Dim ws As Worksheet
        Dim FoundCell As Range
        Set wb = ActiveWorkbook
        Set ws = ActiveSheet

            Const WHAT_TO_FIND As String = "Bingo"

            Set FoundCell = ws.Range("A:A").Find(What:=WHAT_TO_FIND)
            If Not FoundCell Is Nothing Then
                MsgBox (WHAT_TO_FIND & " found in row: " & FoundCell.Row)
                MsgBox (WHAT_TO_FIND & " not found")
            End If
End Sub

For your second method, you are using Bingo as a variable instead of a string literal. This is a good example of why I add Option Explicit to the top of all of my code modules, as when you try to run the code it will direct you to this "variable" which is undefined and not intended to be a variable at all.

Additionally, when you are using With...End With you need a period . before you reference Cells, so Cells should be .Cells. This mimics the normal qualifying behavior (i.e. Sheet1.Cells.Find..)

Change Bingo to "Bingo" and change Cells to .Cells

With Sheet1
        Set FoundCell = .Cells.Find(What:="Bingo", After:=.Cells(1, 1), _
        LookIn:=xlValues, lookat:=xlPart, SearchOrder:=xlByRows, _
        SearchDirection:=xlNext, MatchCase:=False, SearchFormat:=False)
    End With

If Not FoundCell Is Nothing Then
        MsgBox ("""Bingo"" found in row " & FoundCell.Row)
        MsgBox ("Bingo not found")
End If


In my

With Sheet1
End With

The Sheet1 refers to a worksheet's code name, not the name of the worksheet itself. For example, say I open a new blank Excel workbook. The default worksheet is just Sheet1. I can refer to that in code either with the code name of Sheet1 or I can refer to it with the index of Sheets("Sheet1"). The advantage to using a codename is that it does not change if you change the name of the worksheet.

Continuing this example, let's say I renamed Sheet1 to Data. Using Sheet1 would continue to work, as the code name doesn't change, but now using Sheets("Sheet1") would return an error and that syntax must be updated to the new name of the sheet, so it would need to be Sheets("Data").

In the VB Editor you would see something like this:

code object explorer example

Notice how, even though I changed the name to Data, there is still a Sheet1 to the left. That is what I mean by codename.

The Data worksheet can be referenced in two ways:

Debug.Print Sheet1.Name
Debug.Print Sheets("Data").Name

Both should return Data

More discussion on worksheet code names can be found here.

Pass a reference to DOM object with ng-click

While you do the following, technically speaking:

<button ng-click="doSomething($event)"></button>
// In controller:
$scope.doSomething = function($event) {
  //reference to the button that triggered the function:

This is probably something you don't want to do as AngularJS philosophy is to focus on model manipulation and let AngularJS do the rendering (based on hints from the declarative UI). Manipulating DOM elements and attributes from a controller is a big no-no in AngularJS world.

You might check this answer for more info:

How to trigger SIGUSR1 and SIGUSR2?

They are signals that application developers use. The kernel shouldn't ever send these to a process. You can send them using kill(2) or using the utility kill(1).

If you intend to use signals for synchronization you might want to check real-time signals (there's more of them, they are queued, their delivery order is guaranteed etc).

How do I check if a given Python string is a substring of another one?

Try using in like this:

>>> x = 'hello'
>>> y = 'll'
>>> y in x

How to get the index of an item in a list in a single step?

For simple types you can use "IndexOf" :

List<string> arr = new List<string>();
int i = arr.IndexOf("bbb"); // RETURNS 1.

TypeError: $(...).autocomplete is not a function

Simple solution: The sequence is really matter while including the auto complete libraries:

<link href="" rel="Stylesheet"></link>
<script src=''></script>
<script src="" ></script>

Call of overloaded function is ambiguous


p.setval(static_cast<const char *>(0));


p.setval(static_cast<unsigned int>(0));

As indicated by the error, the type of 0 is int. This can just as easily be cast to an unsigned int or a const char *. By making the cast manually, you are telling the compiler which overload you want.

git push: permission denied (public key)

I faced the same problem.Ask your friend to add you as a collaborator by going to his repo settings and adding a new collaborator.

You will recieve an invite email ,accept it.Then you are good to go. Just make sure that you have added right remote.

Comparing two java.util.Dates to see if they are in the same day

Convert dates to Java 8 java.time.LocalDate as seen here.

LocalDate localDate1 = date1.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
LocalDate localDate2 = date2.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();

// compare dates
assertTrue("Not on the same day", localDate1.equals(localDate2));

Why doesn't Dijkstra's algorithm work for negative weight edges?

The other answers so far demonstrate pretty well why Dijkstra's algorithm cannot handle negative weights on paths.

But the question itself is maybe based on a wrong understanding of the weight of paths. If negative weights on paths would be allowed in pathfinding algorithms in general, then you would get permanent loops that would not stop.

Consider this:

A  <- 5 ->  B  <- (-1) ->  C <- 5 -> D

What is the optimal path between A and D?

Any pathfinding algorithm would have to continuously loop between B and C because doing so would reduce the weight of the total path. So allowing negative weights for a connection would render any pathfindig algorithm moot, maybe except if you limit each connection to be used only once.

So, to explain this in more detail, consider the following paths and weights:

Path               | Total weight
ABCD               | 9
ABCBCD             | 7
ABCBCBCD           | 5
ABCBCBCBCD         | 3

So, what's the perfect path? Any time the algorithm adds a BC step, it reduces the total weight by 2.

So the optimal path is A (BC) D with the BC part being looped forever.

Since Dijkstra's goal is to find the optimal path (not just any path), it, by definition, cannot work with negative weights, since it cannot find the optimal path.

Dijkstra will actually not loop, since it keeps a list of nodes that it has visited. But it will not find a perfect path, but instead just any path.

How do I migrate an SVN repository with history to a new Git repository?

I just wanted to add my contribution to the Git community. I wrote a simple bash script which automates the full import. Unlike other migration tools, this tool relies on native git instead of jGit. This tool also supports repositories with a large revision history and or large blobs. It's available via github:

This script will convert projects stored in SVN with the following format:


This scheme is also popular and supported as well:


Each project will get synchronized over by project name:

Ex: ./migration project1

If you wish to convert the full repo over, use the following syntax:

Ex: ./migration .

Make DateTimePicker work as TimePicker only in WinForms

If you want to do it from properties, you can do this by setting the Format property of DateTimePicker to DateTimePickerFormat.Time and ShowUpDown property to true. Also, customFormat can be set in properties.

How to increase editor font size?

There are two possible ways of doing this:

1. Setting a custom shortcut for change font size:

Preferences -> KeyMap -> Editor Action -> Dcrease Font size/Increase Font size

And set a shortcut for each purpose.
NOTE: you can set a mouse shortcut as well in a custom shortcut.
This custom shortcut feature is really helpful when are you are migrating from another code editor and is habitual to the use of another shortcut.

Zoom in/out feature custom shortcut setting android studio

2. Set the zoom in and zoom out to mouse scroll with control pressed if you are a windows user and command pressed if you are a macOS user.

Preferences -> Editor -> General -> Mark checked Option -> Change Font size with Command + mouse wheel

Font Zoom In/Out Editor Window android studio

How do I set vertical space between list items?

<br>between <li></li> line entries seems to work perfectly well in all web browsers that I've tried, but it fails to pass the on-line W3C CSS3 checker. It gives me precisely the line spacing I am after. As far as I am concerned, since it undoubtedly works, I am persisting in using it, whatever W3C says, until someone can come up with a good legal alternative.

Merge (with squash) all changes from another branch as a single commit

I have created my own git alias to do exactly this. I'm calling it git freebase! It will take your existing messy, unrebasable feature branch and recreate it so that it becomes a new branch with the same name with its commits squashed into one commit and rebased onto the branch you specify (master by default). At the very end, it will allow you to use whatever commit message you like for your newly "freebased" branch.

Install it by placing the following alias in your .gitconfig:

  freebase = "!f() { \
    TOPIC="$(git branch | grep '\\*' | cut -d ' ' -f2)"; \
    NEWBASE="${1:-master}"; \
    PREVSHA1="$(git rev-parse HEAD)"; \
    echo "Freebaseing $TOPIC onto $NEWBASE, previous sha1 was $PREVSHA1"; \
    echo "---"; \
    git reset --hard "$NEWBASE"; \
    git merge --squash "$PREVSHA1"; \
    git commit; \
  }; f"

Use it from your feature branch by running: git freebase <new-base>

I've only tested this a few times, so read it first and make sure you want to run it. As a little safety measure it does print the starting sha1 so you should be able to restore your old branch if anything goes wrong.

I'll be maintaining it in my dotfiles repo on github:

How to Make A Chevron Arrow Using CSS?

An other approach using borders and no CSS3 properties :

div, div:after{_x000D_
    border-width: 80px 0 80px 80px;_x000D_
    border-color: transparent transparent transparent #000;_x000D_
    left:-115px; top:-80px;_x000D_

Animate the transition between fragments

If you can afford to tie yourself to just Lollipop and later, this seems to do the trick:

import android.transition.Slide;
import android.util.Log;
import android.view.Gravity;
f = new MyFragment();
f.setEnterTransition(new Slide(Gravity.END));
f.setExitTransition(new Slide(Gravity.START));
    .replace(, f, FRAG_TAG)  // FRAG_TAG is the tag for your fragment

Kotlin version:

f = MyFragment().apply {
    enterTransition = Slide(Gravity.END)
    exitTransition = Slide(Gravity.START)
    .replace(, f, FRAG_TAG)  // FRAG_TAG is the tag for your fragment

Hope this helps.

#1064 -You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version

I see two problems:

DOUBLE(10) precision definitions need a total number of digits, as well as a total number of digits after the decimal:

DOUBLE(10,8) would make be ten total digits, with 8 allowed after the decimal.

Also, you'll need to specify your id column as a key :

CREATE TABLE transactions( 
location varchar(50) NOT NULL, 
description varchar(50) NOT NULL, 
category varchar(50) NOT NULL, 
amount double(10,9) NOT NULL, 
type varchar(6) NOT NULL,  
notes varchar(512), 
receipt int(10), 

Meaning of "n:m" and "1:n" in database design

What does the letter 'N' on a relationship line in an Entity Relationship diagram mean? Any number


M - ordinality - describes the minimum (ordinal vs mandatory)

N - cardinality - describes the miximum

1:N (n=0,1,2,3...) one to zero or more

M:N (m and n=0,1,2,3...) zero or more to zero or more (many to many)

1:1 one to one

Find more here:

Using Spring 3 autowire in a standalone Java application

I case you are running SpringBoot:

I just had the same problem, that I could not Autowire one of my services from the static main method.

See below an approach in case you are relying on

public class PricingOnlineApplication {

    OrchestratorService orchestratorService;

    public static void main(String[] args) {
        ConfigurableApplicationContext context =, args);
        PricingOnlineApplication application = context.getBean(PricingOnlineApplication.class);


    private void start() {


I noticed that returns a context which can be used similar to the above described approaches. From there, it is exactly the same as above ;-)

Encrypt and decrypt a string in C#?

I have an open source project called X509Crypto that leverages certificates to encrypt and decrypt strings. It's very easy to use. Here is an example for how to use it:

1. Use the X509Crypto Commandline Interface (CLI) to generate a new encryption certificate and key pair

X509Crypto> makecert -context user -keysize medium -alias myvault

Certificate with thumbprint B31FE7E7AE5229F8186782742CF579197FA859FD was added to X509Alias "myvault" in the user X509Context


2. Use the Encrypt CLI command to add a secret to your new X509Alias

X509Crypto> encrypt -text -alias myvault -context user -secret apikey -in "80EAF03248965AC2B78090"

Secret apikey has been added to X509Alias myvault in the user X509Context


3. Reference the secret in your program

Once you have an X509Alias established with your secret(s) added, it is trivial to retreive them in your program with the Org.X509Crypto nuget package installed:

using Org.X509Crypto;

namespace SampleApp
    class Program
        static void Main(string[] args)
            var Alias = new X509Alias(@"myvault", X509Context.UserReadOnly);
            var apiKey = Alias.RecoverSecret(@"apikey");

Best way to get all selected checkboxes VALUES in jQuery

You want the :checkbox:checked selector and map to create an array of the values:

var checkedValues = $('input:checkbox:checked').map(function() {
    return this.value;

If your checkboxes have a shared class it would be faster to use that instead, eg. $('.mycheckboxes:checked'), or for a common name $('input[name="Foo"]:checked')

- Update -

If you don't need IE support then you can now make the map() call more succinct by using an arrow function:

var checkedValues = $('input:checkbox:checked').map((i, el) => el.value).get();

Call a stored procedure with parameter in c#

cmd.Parameters.Add(String parameterName, Object value) is deprecated now. Instead use cmd.Parameters.AddWithValue(String parameterName, Object value)

Add(String parameterName, Object value) has been deprecated. Use AddWithValue(String parameterName, Object value)

There is no difference in terms of functionality. The reason they deprecated the cmd.Parameters.Add(String parameterName, Object value) in favor of AddWithValue(String parameterName, Object value) is to give more clarity. Here is the MSDN reference for the same

private void button1_Click(object sender, EventArgs e) {
  using (SqlConnection con = new SqlConnection(dc.Con)) {
    using (SqlCommand cmd = new SqlCommand("sp_Add_contact", con)) {
      cmd.CommandType = CommandType.StoredProcedure;

      cmd.Parameters.AddWithValue("@FirstName", SqlDbType.VarChar).Value = txtFirstName.Text;
      cmd.Parameters.AddWithValue("@LastName", SqlDbType.VarChar).Value = txtLastName.Text;


async await return Task

async methods are different than normal methods. Whatever you return from async methods are wrapped in a Task.

If you return no value(void) it will be wrapped in Task, If you return int it will be wrapped in Task<int> and so on.

If your async method needs to return int you'd mark the return type of the method as Task<int> and you'll return plain int not the Task<int>. Compiler will convert the int to Task<int> for you.

private async Task<int> MethodName()
    await SomethingAsync();
    return 42;//Note we return int not Task<int> and that compiles

Sameway, When you return Task<object> your method's return type should be Task<Task<object>>

public async Task<Task<object>> MethodName()
     return Task.FromResult<object>(null);//This will compile

Since your method is returning Task, it shouldn't return any value. Otherwise it won't compile.

public async Task MethodName()
     return;//This should work but return is redundant and also method is useless.

Keep in mind that async method without an await statement is not async.

Python Socket Receive Large Amount of Data

Most of the answers describe some sort of recvall() method. If your bottleneck when receiving data is creating the byte array in a for loop, I benchmarked three approaches of allocating the received data in the recvall() method:

Byte string method:

arr = b''
while len(arr) < msg_len:
    arr += sock.recv(max_msg_size)

List method:

fragments = []
while True: 
    chunk = sock.recv(max_msg_size)
    if not chunk: 
arr = b''.join(fragments)

Pre-allocated bytearray method:

arr = bytearray(msg_len)
pos = 0
while pos < msg_len:
    arr[pos:pos+max_msg_size] = sock.recv(max_msg_size)
    pos += max_msg_size


enter image description here

How to open a new HTML page using jQuery?

You need to use ajax.

  url: 'ajax/test.html',
  success: function(data) {
    alert('Load was performed.');

What do I use for a max-heap implementation in Python?

To elaborate on, here is a fully documented, annotated and tested Python 3 implementation for the general case.

from __future__ import annotations  # To allow "MinHeap.push -> MinHeap:"
from typing import Generic, List, Optional, TypeVar
from heapq import heapify, heappop, heappush, heapreplace

T = TypeVar('T')

class MinHeap(Generic[T]):
    MinHeap provides a nicer API around heapq's functionality.
    As it is a minimum heap, the first element of the heap is always the
    >>> h = MinHeap([3, 1, 4, 2])
    >>> h[0]
    >>> h.peek()
    >>> h.push(5)  # N.B.: the array isn't always fully sorted.
    [1, 2, 4, 3, 5]
    >>> h.pop()
    >>> h.pop()
    >>> h.pop()
    >>> h.push(3).push(2)
    [2, 3, 4, 5]
    >>> h.replace(1)
    >>> h
    [1, 3, 4, 5]
    def __init__(self, array: Optional[List[T]] = None):
        if array is None:
            array = []
        self.h = array
    def push(self, x: T) -> MinHeap:
        heappush(self.h, x)
        return self  # To allow chaining operations.
    def peek(self) -> T:
        return self.h[0]
    def pop(self) -> T:
        return heappop(self.h)
    def replace(self, x: T) -> T:
        return heapreplace(self.h, x)
    def __getitem__(self, i) -> T:
        return self.h[i]
    def __len__(self) -> int:
        return len(self.h)
    def __str__(self) -> str:
        return str(self.h)
    def __repr__(self) -> str:
        return str(self.h)

class Reverse(Generic[T]):
    Wrap around the provided object, reversing the comparison operators.
    >>> 1 < 2
    >>> Reverse(1) < Reverse(2)
    >>> Reverse(2) < Reverse(1)
    >>> Reverse(1) <= Reverse(2)
    >>> Reverse(2) <= Reverse(1)
    >>> Reverse(2) <= Reverse(2)
    >>> Reverse(1) == Reverse(1)
    >>> Reverse(2) > Reverse(1)
    >>> Reverse(1) > Reverse(2)
    >>> Reverse(2) >= Reverse(1)
    >>> Reverse(1) >= Reverse(2)
    >>> Reverse(1)
    def __init__(self, x: T) -> None:
        self.x = x
    def __lt__(self, other: Reverse) -> bool:
        return other.x.__lt__(self.x)
    def __le__(self, other: Reverse) -> bool:
        return other.x.__le__(self.x)
    def __eq__(self, other) -> bool:
        return self.x == other.x
    def __ne__(self, other: Reverse) -> bool:
        return other.x.__ne__(self.x)
    def __ge__(self, other: Reverse) -> bool:
        return other.x.__ge__(self.x)
    def __gt__(self, other: Reverse) -> bool:
        return other.x.__gt__(self.x)
    def __str__(self):
        return str(self.x)
    def __repr__(self):
        return str(self.x)

class MaxHeap(MinHeap):
    MaxHeap provides an implement of a maximum-heap, as heapq does not provide
    it. As it is a maximum heap, the first element of the heap is always the
    largest. It achieves this by wrapping around elements with Reverse,
    which reverses the comparison operations used by heapq.
    >>> h = MaxHeap([3, 1, 4, 2])
    >>> h[0]
    >>> h.peek()
    >>> h.push(5)  # N.B.: the array isn't always fully sorted.
    [5, 4, 3, 1, 2]
    >>> h.pop()
    >>> h.pop()
    >>> h.pop()
    >>> h.pop()
    >>> h.push(3).push(2).push(4)
    [4, 3, 2, 1]
    >>> h.replace(1)
    >>> h
    [3, 1, 2, 1]
    def __init__(self, array: Optional[List[T]] = None):
        if array is not None:
            array = [Reverse(x) for x in array]  # Wrap with Reverse.
    def push(self, x: T) -> MaxHeap:
        return self
    def peek(self) -> T:
        return super().peek().x
    def pop(self) -> T:
        return super().pop().x
    def replace(self, x: T) -> T:
        return super().replace(Reverse(x)).x

if __name__ == '__main__':
    import doctest

"code ." Not working in Command Line for Visual Studio Code on OSX/Mac

I was having the same problem. I have to add Vs Code to my applications folder. It worked without editing a file.

  1. Open Applications Folder

enter image description here

  1. Search for VS Code in your search

enter image description here

  1. Drag Vs Code to the applications folder

enter image description here

This will work for you.

How do I "commit" changes in a git submodule?

Note that if you have committed a bunch of changes in various submodules, you can (or will be soon able to) push everything in one go (ie one push from the parent repo), with:

git push --recurse-submodules=on-demand

git1.7.11 ([ANNOUNCE] Git 1.7.11.rc1) mentions:

"git push --recurse-submodules" learned to optionally look into the histories of submodules bound to the superproject and push them out.

Probably done after this patch and the --on-demand option:


Make sure all submodule commits used by the revisions to be pushed are available on a remote tracking branch.

  • If check is used, it will be checked that all submodule commits that changed in the revisions to be pushed are available on a remote.
    Otherwise the push will be aborted and exit with non-zero status.
  • If on-demand is used, all submodules that changed in the revisions to be pushed will be pushed.
    If on-demand was not able to push all necessary revisions it will also be aborted and exit with non-zero status.

This option only works for one level of nesting. Changes to the submodule inside of another submodule will not be pushed.

SQL comment header examples

Here's what I currently use. The triple comment ( / * / * / * ) is for an integration that picks out header comments from the object definition.


    Name:           pr_ProcName
    Author:         Joe Smith
    Written:        6/15/16
    Purpose:        Short description about the proc.

    Edit History:   6/15/16 - Joe Smith
                        + Initial creation.
                    6/22/16 - Jaden Smith
                        + Change source to blahblah
                        + Optimized JOIN
                    6/30/16 - Joe Smith
                        + Reverted changes made by Jaden.


How do I pull files from remote without overwriting local files?

Well, yes, and no...

I understand that you want your local copies to "override" what's in the remote, but, oh, man, if someone has modified the files in the remote repo in some different way, and you just ignore their changes and try to "force" your own changes without even looking at possible conflicts, well, I weep for you (and your coworkers) ;-)

That said, though, it's really easy to do the "right thing..."

Step 1:

git stash

in your local repo. That will save away your local updates into the stash, then revert your modified files back to their pre-edit state.

Step 2:

git pull

to get any modified versions. Now, hopefully, that won't get any new versions of the files you're worried about. If it doesn't, then the next step will work smoothly. If it does, then you've got some work to do, and you'll be glad you did.

Step 3:

git stash pop

That will merge your modified versions that you stashed away in Step 1 with the versions you just pulled in Step 2. If everything goes smoothly, then you'll be all set!

If, on the other hand, there were real conflicts between what you pulled in Step 2 and your modifications (due to someone else editing in the interim), you'll find out and be told to resolve them. Do it.

Things will work out much better this way - it will probably keep your changes without any real work on your part, while alerting you to serious, serious issues.

Convert java.util.Date to java.time.LocalDate

What's wrong with this 1 simple line?

new LocalDateTime(new Date().getTime()).toLocalDate();

Declare and assign multiple string variables at the same time

string Camnr , Klantnr , Ordernr , Bonnr , Volgnr , Omschrijving , Startdatum , Bonprioriteit , Matsoort , Dikte , Draaibaarheid , Draaiomschrijving , Orderleverdatum , Regeltaakkode , Gebruiksvoorkeur , Regelcamprog , Regeltijd , Orderrelease;
Camnr = Klantnr = Ordernr = Bonnr = Volgnr = Omschrijving = Startdatum = Bonprioriteit = Matsoort = Dikte = Draaibaarheid = Draaiomschrijving = Orderleverdatum = Regeltaakkode = Gebruiksvoorkeur = Regelcamprog = Regeltijd = Orderrelease = string.Empty;

Binary search (bisection) in Python

Many good solutions above but I haven't seen a simple (KISS keep it simple (cause I'm) stupid use of the Python built in/generic bisect function to do a binary search. With a bit of code around the bisect function, I think I have an example below where I have tested all cases for a small string array of names. Some of the above solutions allude to/say this, but hopefully the simple code below will help anyone confused like I was.

Python bisect is used to indicate where to insert an a new value/search item into a sorted list. The below code which uses bisect_left which will return the index of the hit if the search item in the list/array is found (Note bisect and bisect_right will return the index of the element after the hit or match as the insertion point) If not found, bisect_left will return an index to the next item in the sorted list which will not == the search value. The only other case is where the search item would go at the end of the list where the index returned would be beyond the end of the list/array, and which in the code below the early exit by Python with "and" logic handles. (first condition False Python does not check subsequent conditions)

from bisect import bisect_left
lenNames = len(names)
while search !="none":
    search =input("Enter name to search for or 'none' to terminate program:")
    if search == "none":
    i = bisect_left(names,search)
    print(i) # show index returned by Python bisect_left
    if i < (lenNames) and names[i] == search:
        print(names[i],"found") #return True - if function
        print(search,"not found") #return False – if function
##Exhaustive test cases:
##Enter name to search for or 'none' to terminate program:Zayed
##Zayed found
##Enter name to search for or 'none' to terminate program:Zach
##Zach found
##Enter name to search for or 'none' to terminate program:Jalan
##Jalan found
##Enter name to search for or 'none' to terminate program:Donny
##Donny found
##Enter name to search for or 'none' to terminate program:Adam
##Adam found
##Enter name to search for or 'none' to terminate program:Abie
##Abie not found
##Enter name to search for or 'none' to terminate program:Carla
##Carla not found
##Enter name to search for or 'none' to terminate program:Ed
##Ed not found
##Enter name to search for or 'none' to terminate program:Roger
##Roger not found
##Enter name to search for or 'none' to terminate program:Zap
##Zap not found
##Enter name to search for or 'none' to terminate program:Zyss
##Zyss not found

How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?

This may work:

Public Function getControls(Of T)() As List(Of T)
    Dim st As New Stack(Of Control)
    Dim ctl As Control
    Dim li As New List(Of T)


    While st.Count > 0
        ctl = st.Pop
        For Each c In ctl.Controls
            st.Push(CType(c, Control))
            If c.GetType Is GetType(T) Then
                li.Add(CType(c, T))
            End If
    End While

    Return li
End Function

I think the function to get all controls you are talking about is only available to WPF.

Most efficient way to see if an ArrayList contains an object in Java

Even if the equals method were comparing those two fields, then logically, it would be just the same code as you doing it manually. OK, it might be "messy", but it's still the correct answer

MySQL Nested Select Query?

You just need to write the first query as a subquery (derived table), inside parentheses, pick an alias for it (t below) and alias the columns as well.

The DISTINCT can also be safely removed as the internal GROUP BY makes it redundant:

SELECT DATE(`date`) AS `date` , COUNT(`player_name`) AS `player_count`
    SELECT MIN(`date`) AS `date`, `player_name`
    FROM `player_playtime`
    GROUP BY `player_name`
) AS t

Since the COUNT is now obvious that is only counting rows of the derived table, you can replace it with COUNT(*) and further simplify the query:

SELECT , COUNT(*) AS player_count
    SELECT DATE(MIN(`date`)) AS date
    FROM player_playtime
    GROUP BY player_name
) AS t

nodeJs callbacks simple example

const fs = require('fs');

fs.stat('input.txt', function (err, stats) {
    } else {
        console.log('Completed Reading File');

'fs' is a node module which helps you to read file. Callback function will make sure that your file named 'input.txt' is completely read before it gets executed. fs.stat() function is to get file information like file size, date created and date modified.

Get started with Latex on Linux

I would personally use a complete editing package such as:

  • TexWorks
  • TexStudio

Then I would install "MikTeX" as the compiling package, which allows you to generate a PDF from your document, using the pdfLaTeX compiler.

Verify host key with pysftp

Cook book to use different ways of pysftp.CnOpts() and hostkeys options.

Source :

Host Key checking is enabled by default. It will use ~/.ssh/known_hosts by default. If you wish to disable host key checking (NOT ADVISED) you will need to modify the default CnOpts and set the .hostkeys to None.

import pysftp
cnopts = pysftp.CnOpts()
cnopts.hostkeys = None
with pysftp.Connection('host', username='me', password='pass', cnopts=cnopts):
    # do stuff here

To use a completely different known_hosts file, you can override CnOpts looking for ~/.ssh/known_hosts by specifying the file when instantiating.

import pysftp
cnopts = pysftp.CnOpts(knownhosts='path/to/your/knownhostsfile')

with pysftp.Connection('host', username='me', password='pass', cnopts=cnopts):
    # do stuff here

If you wish to use ~/.ssh/known_hosts but add additional known host keys you can merge with update additional known_host format files by using .load method.

import pysftp
cnopts = pysftp.CnOpts()
with pysftp.Connection('host', username='me', password='pass', cnopts=cnopts):
    # do stuff here

"Series objects are mutable and cannot be hashed" error

gene_name = no_headers.iloc[1:,[1]]

This creates a DataFrame because you passed a list of columns (single, but still a list). When you later do this:


you now have a Series object with a single value. You can't hash the Series.

The solution is to create Series from the start.

gene_type = no_headers.iloc[1:,0]
gene_name = no_headers.iloc[1:,1]
disease_name = no_headers.iloc[1:,2]

Also, where you have orph_dict[gene_name[x]] =+ 1, I'm guessing that's a typo and you really mean orph_dict[gene_name[x]] += 1 to increment the counter.

How to loop backwards in python?

for x in reversed(whatever):

This works on basically everything that has a defined order, including xrange objects and lists.

how to add value to a tuple?

As mentioned in other answers, tuples are immutable once created, and a list might serve your purposes better.

That said, another option for creating a new tuple with extra items is to use the splat operator:

new_tuple = (*old_tuple, 'new', 'items')

I like this syntax because it looks like a new tuple, so it clearly communicates what you're trying to do.

Using splat, a potential solution is:

list = [(*i, ''.join(i)) for i in list]

Reset all the items in a form

Quick answer, maybe it'll help:

private void button1_Click(object sender, EventArgs e)
    Form2 f2 = new Form2();
    while (f2.DialogResult == DialogResult.Retry)
        f2 = new Form2();

and in Form2 (The 'settings' Form):

private void button1_Click(object sender, EventArgs e)
    DialogResult = DialogResult.OK;

private void button2_Click(object sender, EventArgs e)
    DialogResult = DialogResult.Retry;

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

Someone should mark Johannes Weiß's comment as the answer to this question. That is exactly why xml documents can't just be loaded in a DOM Document class.

How do you truncate all tables in a database using TSQL?

The hardest part of truncating all tables is removing and re-ading the foreign key constraints.

The following query creates the drop & create statements for each constraint relating to each table name in @myTempTable. If you would like to generate these for all the tables, you may simple use information schema to gather these table names instead.

DECLARE @myTempTable TABLE (tableName varchar(200))
INSERT INTO @myTempTable(tableName) VALUES

-- DROP FK Contraints
SELECT 'alter table '+quotename(schema_name(ob.schema_id))+
  '.'+quotename(object_name(ob.object_id))+ ' drop constraint ' + quotename( 
  FROM sys.objects ob INNER JOIN sys.foreign_keys fk ON fk.parent_object_id = ob.object_id
  WHERE fk.referenced_object_id IN 
         SELECT so.object_id 
         FROM sys.objects so JOIN sys.schemas sc
         ON so.schema_id = sc.schema_id
         WHERE IN (SELECT * FROM @myTempTable)  AND'dbo'  AND type in (N'U'))

 -- CREATE FK Contraints
 SELECT 'ALTER TABLE [PIMSUser].[dbo].[' +cast( as varchar(255)) + '] WITH NOCHECK ADD CONSTRAINT ['+ cast( as varchar(255)) +'] FOREIGN KEY (['+ cast( as varchar(255)) +'])
      REFERENCES [PIMSUser].[dbo].['+ cast( as varchar(255)) +'] (['+cast( as varchar(255))+'])'
FROM  sysobjects f
      INNER JOIN sys.sysobjects c ON f.parent_obj =
      INNER JOIN sys.sysreferences r ON = r.constid
      INNER JOIN sys.sysobjects p ON r.rkeyid =
      INNER JOIN sys.syscolumns rc ON r.rkeyid = and r.rkey1 = rc.colid
      INNER JOIN sys.syscolumns fc ON r.fkeyid = and r.fkey1 = fc.colid
      f.type = 'F'
      cast( as varchar(255)) IN (SELECT * FROM @myTempTable)

I then just copy out the statements to run - but with a bit of dev effort you could use a cursor to run them dynamically.

jQuery Form Validation before Ajax submit

You can try doing:

if($("#form").validate()) {
 return true;
} else {
 return false;

Unable to compile class for JSP: The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files

The class format of JDK8 has changed and thats the reason why Tomcat is not able to compile JSPs. Try to get a newer version of Tomcat.

I recently had the same problem. This is a bug in Tomcat, or rather, JDK 8 has a slightly different class file format than what prior-JDK8 versions had. This causes inconsistency and Tomcat is not able to compile JSPs in JDK8.

See following references:

Python equivalent to 'hold on' in Matlab

Just call at the end:

import numpy as np
import matplotlib.pyplot as plt

for i in np.arange(1,5):
    z = 68 + 4 * np.random.randn(50)
    zm = np.cumsum(z) / range(1,len(z)+1)

n = np.arange(1,51)
su = 68 + 4 / np.sqrt(n)
sl = 68 - 4 / np.sqrt(n)


How can I run Tensorboard on a remote server?

Another approach is to use a reverse proxy, which allows you to view Tensorboard from any internet connected device without SSHing. This approach can make it far easier / tractable to view Tensorboard on mobile devices, for example.


1) Download reverse proxy Ngrok on your remote machine hosting Tensorboard. See for instructions (~5 minute setup).

2) Run ngrok http 6006 (assuming you're hosting Tensorboard on port 6006)

3) Save the URL that ngrok outputs:

enter image description here

4) Enter that into any browser to view TensorBoard:

enter image description here

Special thanks to Sam Kirkiles

FromBody string parameter is giving null

Try the below code:

public async Task Test()
   using (var reader = new StreamReader(Request.Body, Encoding.UTF8))
      var textFromBody = await reader.ReadToEndAsync();                    

isset PHP isset($_GET['something']) ? $_GET['something'] : ''

You have encountered the ternary operator. It's purpose is that of a basic if-else statement. The following pieces of code do the same thing.


$something = isset($_GET['something']) ? $_GET['something'] : "failed";


if (isset($_GET['something'])) {
    $something = $_GET['something'];
} else {
    $something = "failed";

What does a bitwise shift (left or right) do and what is it used for?

Here is an applet where you can exercise some bit-operations, including shifting.

You have a collection of bits, and you move some of them beyond their bounds:

1111 1110 << 2
1111 1000

It is filled from the right with fresh zeros. :)

0001 1111 >> 3
0000 0011

Filled from the left. A special case is the leading 1. It often indicates a negative value - depending on the language and datatype. So often it is wanted, that if you shift right, the first bit stays as it is.

1100 1100 >> 1
1110 0110

And it is conserved over multiple shifts:

1100 1100 >> 2
1111 0011

If you don't want the first bit to be preserved, you use (in Java, Scala, C++, C as far as I know, and maybe more) a triple-sign-operator:

1100 1100 >>> 1
0110 0110

There isn't any equivalent in the other direction, because it doesn't make any sense - maybe in your very special context, but not in general.

Mathematically, a left-shift is a *=2, 2 left-shifts is a *=4 and so on. A right-shift is a /= 2 and so on.

How to Replace Multiple Characters in SQL?

I suggest you to create a scalar user defined function. This is an example (sorry in advance, because the variable names are in spanish):

CREATE FUNCTION [dbo].[Udf_ReplaceChars] (
  @cadena VARCHAR(500),  -- String to manipulate
  @caracteresElim VARCHAR(100),  -- String of characters to be replaced
  @caracteresReem VARCHAR(100)   -- String of characters for replacement
  DECLARE @cadenaFinal VARCHAR(500), @longCad INT, @pos INT, @caracter CHAR(1), @posCarER INT;
    @cadenaFinal = '',
    @longCad = LEN(@cadena),
    @pos = 1;

  IF LEN(@caracteresElim)<>LEN(@caracteresReem)

  WHILE @pos <= @longCad
        @caracter = SUBSTRING(@cadena,@pos,1),
        @pos = @pos + 1,
        @posCarER = CHARINDEX(@caracter,@caracteresElim);

      IF @posCarER <= 0
          SET @cadenaFinal = @cadenaFinal + @caracter;
          SET @cadenaFinal = @cadenaFinal + SUBSTRING(@caracteresReem,@posCarER,1)

  RETURN @cadenaFinal;

Here is an example using this function:

SELECT dbo.Udf_ReplaceChars('This is a test.','sat','Z47');

And the result is: 7hiZ iZ 4 7eZ7.

As you can see, each character of the @caracteresElim parameter is replaced by the character in the same position from the @caracteresReem parameter.

How do I determine whether an array contains a particular value in Java?

You can use the Arrays class to perform a binary search for the value. If your array is not sorted, you will have to use the sort functions in the same class to sort the array, then search through it.

Can scripts be inserted with innerHTML?

Here is a very interesting solution to your problem:

So use this instead of script tags:

<img src="empty.gif" onload="alert('test');this.parentNode.removeChild(this);" />

"Bitmap too large to be uploaded into a texture"

Addition of the following 2 attributes in (AndroidManifest.xml) worked for me:


How can I make my website's background transparent without making the content (images & text) transparent too?

I think the simplest solution, rather than making the body element partially transparent, would be to add an extra div to hold the background, and change the opacity there, instead.

So you would add a div like:

<div id="background"></div>

And move your body element's background CSS to it, as well as some additional positioning properties, like this:

#background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('images/background.jpg');
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: 100%;
    opacity: 0.8;

Here's an example:

Automated Python to Java translation

Yes Jython does this, but it may or may not be what you want

Ignore python multiple return value

If you're using Python 3, you can you use the star before a variable (on the left side of an assignment) to have it be a list in unpacking.

# Example 1: a is 1 and b is [2, 3]

a, *b = [1, 2, 3]

# Example 2: a is 1, b is [2, 3], and c is 4

a, *b, c = [1, 2, 3, 4]

# Example 3: b is [1, 2] and c is 3

*b, c = [1, 2, 3]       

# Example 4: a is 1 and b is []

a, *b = [1]

sklearn error ValueError: Input contains NaN, infinity or a value too large for dtype('float64')

This might happen inside scikit, and it depends on what you're doing. I recommend reading the documentation for the functions you're using. You might be using one which depends e.g. on your matrix being positive definite and not fulfilling that criteria.

EDIT: How could I miss that:

np.isnan(mat.any()) #and gets False
np.isfinite(mat.all()) #and gets True

is obviously wrong. Right would be:




You want to check wheter any of the element is NaN, and not whether the return value of the any function is a number...

How do I extract value from Json

we can use the below to get key as string from JSON OBJECT

JsonObject json = new JsonObject(); 

this gives the string without double quotes " " in the string

Use Font Awesome Icons in CSS

For this you just need to add content attribute and font-family attribute to the required element via :before or :after wherever applicable.

For example: I wanted to attach an attachment icon after all the a element inside my post. So, first I need to search if such icon exists in fontawesome. Like in the case I found it here, i.e. fa fa-paperclip. Then I would right click the icon there, and go the ::before pseudo property to fetch out the content tag it is using, which in my case I found to be \f0c6. Then I would use that in my css like this:

   .post a:after {
     font-family: FontAwesome,
     content: " \f0c6" /* I added a space before \ for better UI */

Spool Command: Do not output SQL statement to file

My shell script calls the sql file and executes it. The spool output had the SQL query at the beginning followed by the query result.

This did not resolve my problem:

set echo off

This resolved my problem:

set verify off

Javascript regular expression password validation having special characters

it,s work perfect for me and i am sure will work for you guys checkout it easy and accurate

var regix = new RegExp("^(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[!@#\$%\^&\*])(?=. 

if(regix.test(password) == false ) {
     $('.messageBox').html(`<div class="messageStackError">
       password must be a minimum of 8 characters including number, Upper, Lower And 
       one special character

TypeScript and React - children type?

In order to use <Aux> in your JSX, it needs to be a function that returns ReactElement<any> | null. That's the definition of a function component.

However, it's currently defined as a function that returns React.ReactNode, which is a much wider type. As React typings say:

type ReactNode = ReactChild | ReactFragment | ReactPortal | boolean | null | undefined;

Make sure the unwanted types are neutralized by wrapping the returned value into React Fragment (<></>):

const aux: React.FC<AuxProps> = props =>

Execution failed for task ':app:processDebugResources' even with latest build tools

Another possible reason

resConfigs "hdpi", "xhdpi", "xxhdpi", "xxxhdpi"

can be source of this issue