Programs & Examples On #Wix extension

Extensions to the windows packaging software WiX, that's used to create msi installers.

What is PAGEIOLATCH_SH wait type in SQL Server?

PAGEIOLATCH_SH wait type usually comes up as the result of fragmented or unoptimized index.

Often reasons for excessive PAGEIOLATCH_SH wait type are:

  • I/O subsystem has a problem or is misconfigured
  • Overloaded I/O subsystem by other processes that are producing the high I/O activity
  • Bad index management
  • Logical or physical drive misconception
  • Network issues/latency
  • Memory pressure
  • Synchronous Mirroring and AlwaysOn AG

In order to try and resolve having high PAGEIOLATCH_SH wait type, you can check:

  • SQL Server, queries and indexes, as very often this could be found as a root cause of the excessive PAGEIOLATCH_SH wait types
  • For memory pressure before jumping into any I/O subsystem troubleshooting

Always keep in mind that in case of high safety Mirroring or synchronous-commit availability in AlwaysOn AG, increased/excessive PAGEIOLATCH_SH can be expected.

You can find more details about this topic in the article Handling excessive SQL Server PAGEIOLATCH_SH wait types

How to remove a package in sublime text 2

Simple steps for remove any package from Sublime as phpfmt, Xdebug etc..

1- Go to Sublime menu-> Preference or press Ctrl+Shift+P .
2- Choose -> Remove package option, after you choosing it will display all   packge installed in your sublime, select one of them.
3. After selection it will remove, or for better you can restart your system.

How to calculate the time interval between two time strings

Try this

import datetime
import time
start_time = datetime.datetime.now().time().strftime('%H:%M:%S')
time.sleep(5)
end_time = datetime.datetime.now().time().strftime('%H:%M:%S')
total_time=(datetime.datetime.strptime(end_time,'%H:%M:%S') - datetime.datetime.strptime(start_time,'%H:%M:%S'))
print total_time

OUTPUT :

0:00:05

Why I cannot cout a string?

You do not have to reference std::cout or std::endl explicitly.
They are both included in the namespace std. using namespace std instead of using scope resolution operator :: every time makes is easier and cleaner.

#include<iostream>
#include<string>
using namespace std;

Android XML Percent Symbol

Use

<string name="win_percentage">%d%% wins</string>

to get

80% wins as a formatted string.

I'm using String.format() method to get the number inserted instead of %d.

Angular2 material dialog has issues - Did you add it to @NgModule.entryComponents?

In my case, I added my component to declarations and entryComponents and got the same errors. I also needed to add MatDialogModule to imports.

Exception 'open failed: EACCES (Permission denied)' on Android

Add gradle dependencies

implementation 'com.karumi:dexter:4.2.0'

Add below code in your main activity.

import com.karumi.dexter.Dexter;
import com.karumi.dexter.MultiplePermissionsReport;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.multi.MultiplePermissionsListener;
    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_splash);

    new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {


                checkMermission();
            }
        }, 4000);
    }

    private void checkMermission(){
        Dexter.withActivity(this)
                .withPermissions(
                        android.Manifest.permission.READ_EXTERNAL_STORAGE,
                        android.Manifest.permission.WRITE_EXTERNAL_STORAGE,
                        android.Manifest.permission.ACCESS_NETWORK_STATE,
                        Manifest.permission.INTERNET
                ).withListener(new MultiplePermissionsListener() {
            @Override
            public void onPermissionsChecked(MultiplePermissionsReport report) {
                if (report.isAnyPermissionPermanentlyDenied()){
                    checkMermission();
                } else if (report.areAllPermissionsGranted()){
                    // copy some things
                } else {
                    checkMermission();
                }

            }
            @Override
            public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
                token.continuePermissionRequest();
            }
        }).check();
    }

Moment.js - how do I get the number of years since a date, not rounded up?

I found that it would work to reset the month to January for both dates (the provided date and the present):

> moment("02/26/1978", "MM/DD/YYYY").month(0).from(moment().month(0))
"34 years ago"

CSS : center form in page horizontally and vertically

The accepted answer didn't work with my form, even when I stripped it down to the bare minimum and copied & pasted the code. If anyone else is having this problem, please give my solution a try. Basically, you set Top and Left to 50% as the OP did, but offset the form's container with negative margins on the top and left equal to 50% of the div's height and width, respectively. This moves the center point of the Top and Left coordinates to the center of the form. I will stress that the height and width of the form must be specified (not relative). In this example, a 300x300px form div with margins of -150px on the top and left is perfectly centered no matter the window size:

HTML

<body>
    <div class="login_div">
        <form class="login_form" action="#">
        </form>
    </div>
</body>

CSS

.login_div {
    position: absolute;

    width: 300px;
    height: 300px;

    /* Center form on page horizontally & vertically */
    top: 50%;
    left: 50%;
    margin-top: -150px;
    margin-left: -150px;
}

.login_form {
    width: 300px;
    height: 300px;

    background: gray;
    border-radius: 10px;

    margin: 0;
    padding: 0;
}

JSFiddle

Now, for those wondering why I used a container for the form, it's because I like to have the option of placing other elements in the form's vicinity and having them centered as well. The form container is completely unnecessary in this example, but would definitely be useful in other cases. Hope this helps!

Cannot implicitly convert type from Task<>

You need to make TestGetMethod async too and attach await in front of GetIdList(); will unwrap the task to List<int>, So if your helper function is returning Task make sure you have await as you are calling the function async too.

public Task<List<int>> TestGetMethod()
{
    return GetIdList();
}    

async Task<List<int>> GetIdList()
{
    using (HttpClient proxy = new HttpClient())
    {
        string response = await proxy.GetStringAsync("www.test.com");
        List<int> idList = JsonConvert.DeserializeObject<List<int>>();
        return idList;
    }
}

Another option

public async void TestGetMethod(List<int> results)
{
    results = await GetIdList(); // await will unwrap the List<int>
}

How to allocate aligned memory only using the standard library?

MacOS X specific:

  1. All pointers allocated with malloc are 16 bytes aligned.
  2. C11 is supported, so you can just call aligned_malloc (16, size).

  3. MacOS X picks code that is optimised for individual processors at boot time for memset, memcpy and memmove and that code uses tricks that you've never heard of to make it fast. 99% chance that memset runs faster than any hand-written memset16 which makes the whole question pointless.

If you want a 100% portable solution, before C11 there is none. Because there is no portable way to test alignment of a pointer. If it doesn't have to be 100% portable, you can use

char* p = malloc (size + 15);
p += (- (unsigned int) p) % 16;

This assumes that the alignment of a pointer is stored in the lowest bits when converting a pointer to unsigned int. Converting to unsigned int loses information and is implementation defined, but that doesn't matter because we don't convert the result back to a pointer.

The horrible part is of course that the original pointer must be saved somewhere to call free () with it. So all in all I would really doubt the wisdom of this design.

Horizontal line using HTML/CSS

This might be your problem:

height: .05em;

Chrome is a bit funky with decimals, so try a fixed-pixel height:

height: 2px;

How to size an Android view based on its parent's dimensions

I believe that Mayras XML-approach can come in neat. However it is possible to make it more accurate, with one view only by setting the weightSum. I would not call this a hack anymore but in my opinion the most straightforward approach:

<LinearLayout android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:weightSum="1">
    <ImageView android:layout_height="fill_parent"
               android:layout_width="0dp"
               android:layout_weight="0.5"/>
</LinearLayout>

Like this you can use any weight, 0.6 for instance (and centering) is the weight I like to use for buttons.

ToList().ForEach in Linq

employees.ToList().Foreach(u=> { u.SomeProperty = null; u.OtherProperty = null; });

Notice that I used semicolons after each set statement that is -->

u.SomeProperty = null;
u.OtherProperty = null;

I hope this will definitely solve your problem.

Difference Between One-to-Many, Many-to-One and Many-to-Many?

First of all, read all the fine print. Note that NHibernate (thus, I assume, Hibernate as well) relational mapping has a funny correspondance with DB and object graph mapping. For example, one-to-one relationships are often implemented as a many-to-one relationship.

Second, before we can tell you how you should write your O/R map, we have to see your DB as well. In particular, can a single Skill be possesses by multiple people? If so, you have a many-to-many relationship; otherwise, it's many-to-one.

Third, I prefer not to implement many-to-many relationships directly, but instead model the "join table" in your domain model--i.e., treat it as an entity, like this:

class PersonSkill 
{
    Person person;
    Skill skill;    
}

Then do you see what you have? You have two one-to-many relationships. (In this case, Person may have a collection of PersonSkills, but would not have a collection of Skills.) However, some will prefer to use many-to-many relationship (between Person and Skill); this is controversial.

Fourth, if you do have bidirectional relationships (e.g., not only does Person have a collection of Skills, but also, Skill has a collection of Persons), NHibernate does not enforce bidirectionality in your BL for you; it only understands bidirectionality of the relationships for persistence purposes.

Fifth, many-to-one is much easier to use correctly in NHibernate (and I assume Hibernate) than one-to-many (collection mapping).

Good luck!

Bootstrap - How to add a logo to navbar class?

I found a solution on another thread that works - use the pull-left class:

 <a href="#" class="pull-left"><img src="/path/to/image.png"></a> 

Thanks to Michael in this thread:

Bootstrap - How to add a logo to navbar class?

Copy all values from fields in one class to another through reflection

Orika's is simple faster bean mapping framework because it does through byte code generation. It does nested mappings and mappings with different names. For more details, please check here Sample mapping may look complex, but for complex scenarios it would be simple.

MapperFactory factory = new DefaultMapperFactory.Builder().build();
mapperFactory.registerClassMap(mapperFactory.classMap(Book.class,BookDto.class).byDefault().toClassMap());
MapperFacade mapper = factory.getMapperFacade();
BookDto bookDto = mapperFacade.map(book, BookDto.class);

Bootstrap fixed header and footer with scrolling body-content area in fluid-container

Add the following css to disable the default scroll:

body {
    overflow: hidden;
}

And change the #content css to this to make the scroll only on content body:

#content {
    max-height: calc(100% - 120px);
    overflow-y: scroll;
    padding: 0px 10%;
    margin-top: 60px;
}

See fiddle here.


Edit:

Actually, I'm not sure what was the issue you were facing, since it seems that your css is working. I have only added the HTML and the header css statement:

_x000D_
_x000D_
html {_x000D_
  height: 100%;_x000D_
}_x000D_
html body {_x000D_
  height: 100%;_x000D_
  overflow: hidden;_x000D_
}_x000D_
html body .container-fluid.body-content {_x000D_
  position: absolute;_x000D_
  top: 50px;_x000D_
  bottom: 30px;_x000D_
  right: 0;_x000D_
  left: 0;_x000D_
  overflow-y: auto;_x000D_
}_x000D_
header {_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    right: 0;_x000D_
    top: 0;_x000D_
    background-color: #4C4;_x000D_
    height: 50px;_x000D_
}_x000D_
footer {_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    right: 0;_x000D_
    bottom: 0;_x000D_
    background-color: #4C4;_x000D_
    height: 30px;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
<header></header>_x000D_
<div class="container-fluid body-content">_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
  Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>Lorem Ipsum<br/>_x000D_
</div>_x000D_
<footer></footer>
_x000D_
_x000D_
_x000D_

PHP Configuration: It is not safe to rely on the system's timezone settings

I found, bizarrely, that I could fix the errors by placing the timezone declaration at the TOP of my php.ini file.

It was already in my php.ini. Twice, actually. And I was pulling my hair out because everyone was saying there must be another ini being loaded... There wasn't.

Hope this can save someone else the time/hair loss.

How to get jSON response into variable from a jquery script

You should use data.response in your JS instead of json.response.

Comparing Class Types in Java

It prints true on my machine. And it should, otherwise nothing in Java would work as expected. (This is explained in the JLS: 4.3.4 When Reference Types Are the Same)

Do you have multiple classloaders in place?


Ah, and in response to this comment:

I realise I have a typo in my question. I should be like this:

MyImplementedObject obj = new MyImplementedObject ();
if(obj.getClass() == MyObjectInterface.class) System.out.println("true");

MyImplementedObject implements MyObjectInterface So in other words, I am comparing it with its implemented objects.

OK, if you want to check that you can do either:

if(MyObjectInterface.class.isAssignableFrom(obj.getClass()))

or the much more concise

if(obj instanceof MyobjectInterface)

Insert Unicode character into JavaScript

I'm guessing that you actually want Omega to be a string containing an uppercase omega? In that case, you can write:

var Omega = '\u03A9';

(Because Ω is the Unicode character with codepoint U+03A9; that is, 03A9 is 937, except written as four hexadecimal digits.)

Find the IP address of the client in an SSH session

Check if there is an environment variable called:

$SSH_CLIENT 

OR

$SSH_CONNECTION

(or any other environment variables) which gets set when the user logs in. Then process it using the user login script.

Extract the IP:

$ echo $SSH_CLIENT | awk '{ print $1}'
1.2.3.4
$ echo $SSH_CONNECTION | awk '{print $1}'
1.2.3.4

How to clear a data grid view

IF you want to clear not only Data, but also ComboBoxes, Checkboxes, try

dataGridView.Columns.Clear();

Default username password for Tomcat Application Manager

To reset your keyring.

  1. Go into your home folder.

  2. Press ctrl & h to show your hidden folders.

  3. Now look in your .gnome2/keyrings directory.

  4. Find the default.keyring file.

  5. Move that file to a different folder.

  6. Once done, reboot your computer.

Inline Form nested within Horizontal Form in Bootstrap 3

A much simpler solution, without all the inside form-group elements

<div class="form-group">
       <label for="birthday" class="col-xs-2 control-label">Birthday</label>
       <div class="col-xs-10">
           <div class="form-inline">
               <input type="text" class="form-control" placeholder="year" style="width:70px;"/>
               <input type="text" class="form-control" placeholder="month" style="width:80px;"/>
               <input type="text" class="form-control" placeholder="day" style="width:100px;"/>                        
           </div>
     </div>
</div>

... and it will look like this,

enter image description here

Cheers!

HttpClient.GetAsync(...) never returns when using await/async

Since you are using .Result or .Wait or await this will end up causing a deadlock in your code.

you can use ConfigureAwait(false) in async methods for preventing deadlock

like this:

var result = await httpClient.GetAsync("http://stackoverflow.com", HttpCompletionOption.ResponseHeadersRead)
                             .ConfigureAwait(false);

you can use ConfigureAwait(false) wherever possible for Don't Block Async Code .

Regex to validate date format dd/mm/yyyy

I suspect that the following is as accurate as can be expected without knowing when the user's locale switched over from the Julian to the Gregorian calendars.

It accepts either '-', '/', or nothing as separators between year, month, and day, no matter the order.

MMddyyyy:

^(((0[13-9]|1[012])[-/]?(0[1-9]|[12][0-9]|30)|(0[13578]|1[02])[-/]?31|02[-/]?(0[1-9]|1[0-9]|2[0-8]))[-/]?[0-9]{4}|02[-/]?29[-/]?([0-9]{2}(([2468][048]|[02468][48])|[13579][26])|([13579][26]|[02468][048]|0[0-9]|1[0-6])00))$

ddMMyyyy:

^(((0[1-9]|[12][0-9]|30)[-/]?(0[13-9]|1[012])|31[-/]?(0[13578]|1[02])|(0[1-9]|1[0-9]|2[0-8])[-/]?02)[-/]?[0-9]{4}|29[-/]?02[-/]?([0-9]{2}(([2468][048]|[02468][48])|[13579][26])|([13579][26]|[02468][048]|0[0-9]|1[0-6])00))$

yyyyMMdd:

^([0-9]{4}[-/]?((0[13-9]|1[012])[-/]?(0[1-9]|[12][0-9]|30)|(0[13578]|1[02])[-/]?31|02[-/]?(0[1-9]|1[0-9]|2[0-8]))|([0-9]{2}(([2468][048]|[02468][48])|[13579][26])|([13579][26]|[02468][048]|0[0-9]|1[0-6])00)[-/]?02[-/]?29)$

Other than order, these all are accurate to the Julian Calendar (leap year every four years) until 1700, when the Gregorian Calendar diverges from the Julian. It has two issues:

  1. It accepts the year 0000, which doesn't exist in many, but not all, standards. Note that ISO 8601 does accept year 0000 (equivalent to 1 BCE).
  2. It doesn't skip the 10-13 days which were lost when the Gregorian Calendar came into use. This varies by locality though. For example, the Roman Catholic Church skipped 10 days, October 5th through October 14th, 1582, but Greece (the last to switch) skipped February 16th through the 28th of 1923, 13 days, having to take into account the leap years of 1700, 1800, and 1900.

This has been tested against Java's calendar implementation from the year 0001 until the year 9999 with the only discrepancy being the abovementioned 10 days in 1582.

Difference between SurfaceView and View?

A SurfaceView is a custom view in Android that can be used to drawn inside it.

The main difference between a View and a SurfaceView is that a View is drawn in the UI Thread, which is used for all the user interaction.

If you want to update the UI rapidly enough and render a good amount of information in it, a SurfaceView is a better choice.

But there are a few technical insides to the SurfaceView:

1. They are not hardware accelerated.

2. Normal views are rendered when you call the methods invalidate or postInvalidate(), but this does not mean the view will be immediately updated (A VSYNC will be sent, and the OS decides when it gets updated. The SurfaceView can be immediately updated.

3. A SurfaceView has an allocated surface buffer, so it is more costly

Make function wait until element exists

If you want a generic solution using MutationObserver you can use this function

// MIT Licensed
// Author: jwilson8767

/**
 * Waits for an element satisfying selector to exist, then resolves promise with the element.
 * Useful for resolving race conditions.
 *
 * @param selector
 * @returns {Promise}
 */
export function elementReady(selector) {
  return new Promise((resolve, reject) => {
    const el = document.querySelector(selector);
    if (el) {resolve(el);}
    new MutationObserver((mutationRecords, observer) => {
      // Query for elements matching the specified selector
      Array.from(document.querySelectorAll(selector)).forEach((element) => {
        resolve(element);
        //Once we have resolved we don't need the observer anymore.
        observer.disconnect();
      });
    })
      .observe(document.documentElement, {
        childList: true,
        subtree: true
      });
  });
}

Source: https://gist.github.com/jwilson8767/db379026efcbd932f64382db4b02853e
Example how to use it

elementReady('#someWidget').then((someWidget)=>{someWidget.remove();});

Note: MutationObserver has a great browser support; https://caniuse.com/#feat=mutationobserver

Et voilà ! :)

What is the difference between List and ArrayList?

There's no difference between list implementations in both of your examples. There's however a difference in a way you can further use variable myList in your code.

When you define your list as:

List myList = new ArrayList();

you can only call methods and reference members that are defined in the List interface. If you define it as:

ArrayList myList = new ArrayList();

you'll be able to invoke ArrayList-specific methods and use ArrayList-specific members in addition to those whose definitions are inherited from List.

Nevertheless, when you call a method of a List interface in the first example, which was implemented in ArrayList, the method from ArrayList will be called (because the List interface doesn't implement any methods).

That's called polymorphism. You can read up on it.

How can I kill a process by name instead of PID?

Also possible to use:

pkill -f "Process name"

For me, it worked up perfectly. It was what I have been looking for. pkill doesn't work with name without the flag.

When -f is set, the full command line is used for pattern matching.

Move view with keyboard using Swift

Add this to your viewcontroller. Works like a charm. Just adjust the values.

override func viewDidLoad() {
    super.viewDidLoad()        
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:NSNotification.Name.UIKeyboardWillShow, object: nil);
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:NSNotification.Name.UIKeyboardWillHide, object: nil);
}

@objc func keyboardWillShow(sender: NSNotification) {
    self.view.frame.origin.y -= 150
}
@objc func keyboardWillHide(sender: NSNotification) {
    self.view.frame.origin.y += 150
}

Git push error: Unable to unlink old (Permission denied)

sudo chown -R $USER:$USER .

Did the job for me.

How to convert UTF8 string to byte array?

The Google Closure library has functions to convert to/from UTF-8 and byte arrays. If you don't want to use the whole library, you can copy the functions from here. For completeness, the code to convert to a string to a UTF-8 byte array is:

goog.crypt.stringToUtf8ByteArray = function(str) {
  // TODO(user): Use native implementations if/when available
  var out = [], p = 0;
  for (var i = 0; i < str.length; i++) {
    var c = str.charCodeAt(i);
    if (c < 128) {
      out[p++] = c;
    } else if (c < 2048) {
      out[p++] = (c >> 6) | 192;
      out[p++] = (c & 63) | 128;
    } else if (
        ((c & 0xFC00) == 0xD800) && (i + 1) < str.length &&
        ((str.charCodeAt(i + 1) & 0xFC00) == 0xDC00)) {
      // Surrogate Pair
      c = 0x10000 + ((c & 0x03FF) << 10) + (str.charCodeAt(++i) & 0x03FF);
      out[p++] = (c >> 18) | 240;
      out[p++] = ((c >> 12) & 63) | 128;
      out[p++] = ((c >> 6) & 63) | 128;
      out[p++] = (c & 63) | 128;
    } else {
      out[p++] = (c >> 12) | 224;
      out[p++] = ((c >> 6) & 63) | 128;
      out[p++] = (c & 63) | 128;
    }
  }
  return out;
};

Is there a way to access an iteration-counter in Java's for-each loop?

The easiest solution is to just run your own counter thus:

int i = 0;
for (String s : stringArray) {
    doSomethingWith(s, i);
    i++;
}

The reason for this is because there's no actual guarantee that items in a collection (which that variant of for iterates over) even have an index, or even have a defined order (some collections may change the order when you add or remove elements).

See for example, the following code:

import java.util.*;

public class TestApp {
  public static void AddAndDump(AbstractSet<String> set, String str) {
    System.out.println("Adding [" + str + "]");
    set.add(str);
    int i = 0;
    for(String s : set) {
        System.out.println("   " + i + ": " + s);
        i++;
    }
  }

  public static void main(String[] args) {
    AbstractSet<String> coll = new HashSet<String>();
    AddAndDump(coll, "Hello");
    AddAndDump(coll, "My");
    AddAndDump(coll, "Name");
    AddAndDump(coll, "Is");
    AddAndDump(coll, "Pax");
  }
}

When you run that, you can see something like:

Adding [Hello]
   0: Hello
Adding [My]
   0: Hello
   1: My
Adding [Name]
   0: Hello
   1: My
   2: Name
Adding [Is]
   0: Hello
   1: Is
   2: My
   3: Name
Adding [Pax]
   0: Hello
   1: Pax
   2: Is
   3: My
   4: Name

indicating that, rightly so, order is not considered a salient feature of a set.

There are other ways to do it without a manual counter but it's a fair bit of work for dubious benefit.

Why does HTML think “chucknorris” is a color?

The rules for parsing colors on legacy attributes involves additional steps than those mentioned in existing answers. The truncate component to 2 digits part is described as:

  1. Discard all characters except the last 8
  2. Discard leading zeros one by one as long as all components have a leading zero
  3. Discard all characters except the first 2

Some examples:

oooFoooFoooF
000F 000F 000F                <- replace, pad and chunk
0F 0F 0F                      <- leading zeros truncated
0F 0F 0F                      <- truncated to 2 characters from right

oooFooFFoFFF
000F 00FF 0FFF                <- replace, pad and chunk
00F 0FF FFF                   <- leading zeros truncated
00 0F FF                      <- truncated to 2 characters from right

ABCooooooABCooooooABCoooooo
ABC000000 ABC000000 ABC000000 <- replace, pad and chunk
BC000000 BC000000 BC000000    <- truncated to 8 characters from left
BC BC BC                      <- truncated to 2 characters from right

AoCooooooAoCooooooAoCoooooo
A0C000000 A0C000000 A0C000000 <- replace, pad and chunk
0C000000 0C000000 0C000000    <- truncated to 8 characters from left
C000000 C000000 C000000       <- leading zeros truncated
C0 C0 C0                      <- truncated to 2 characters from right

Below is a partial implementation of the algorithm. It does not handle errors or cases where the user enters a valid color.

_x000D_
_x000D_
function parseColor(input) {_x000D_
  // todo: return error if input is ""_x000D_
  input = input.trim();_x000D_
  // todo: return error if input is "transparent"_x000D_
  // todo: return corresponding #rrggbb if input is a named color_x000D_
  // todo: return #rrggbb if input matches #rgb_x000D_
  // todo: replace unicode code points greater than U+FFFF with 00_x000D_
  if (input.length > 128) {_x000D_
    input = input.slice(0, 128);_x000D_
  }_x000D_
  if (input.charAt(0) === "#") {_x000D_
    input = input.slice(1);_x000D_
  }_x000D_
  input = input.replace(/[^0-9A-Fa-f]/g, "0");_x000D_
  while (input.length === 0 || input.length % 3 > 0) {_x000D_
    input += "0";_x000D_
  }_x000D_
  var r = input.slice(0, input.length / 3);_x000D_
  var g = input.slice(input.length / 3, input.length * 2 / 3);_x000D_
  var b = input.slice(input.length * 2 / 3);_x000D_
  if (r.length > 8) {_x000D_
    r = r.slice(-8);_x000D_
    g = g.slice(-8);_x000D_
    b = b.slice(-8);_x000D_
  }_x000D_
  while (r.length > 2 && r.charAt(0) === "0" && g.charAt(0) === "0" && b.charAt(0) === "0") {_x000D_
    r = r.slice(1);_x000D_
    g = g.slice(1);_x000D_
    b = b.slice(1);_x000D_
  }_x000D_
  if (r.length > 2) {_x000D_
    r = r.slice(0, 2);_x000D_
    g = g.slice(0, 2);_x000D_
    b = b.slice(0, 2);_x000D_
  }_x000D_
  return "#" + r.padStart(2, "0") + g.padStart(2, "0") + b.padStart(2, "0");_x000D_
}_x000D_
_x000D_
$(function() {_x000D_
  $("#input").on("change", function() {_x000D_
    var input = $(this).val();_x000D_
    var color = parseColor(input);_x000D_
    var $cells = $("#result tbody td");_x000D_
    $cells.eq(0).attr("bgcolor", input);_x000D_
    $cells.eq(1).attr("bgcolor", color);_x000D_
_x000D_
    var color1 = $cells.eq(0).css("background-color");_x000D_
    var color2 = $cells.eq(1).css("background-color");_x000D_
    $cells.eq(2).empty().append("bgcolor: " + input, "<br>", "getComputedStyle: " + color1);_x000D_
    $cells.eq(3).empty().append("bgcolor: " + color, "<br>", "getComputedStyle: " + color2);_x000D_
  });_x000D_
});
_x000D_
body { font: medium monospace; }_x000D_
input { width: 20em; }_x000D_
table { table-layout: fixed; width: 100%; }
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>_x000D_
_x000D_
<p><input id="input" placeholder="Enter color e.g. chucknorris"></p>_x000D_
<table id="result">_x000D_
  <thead>_x000D_
    <tr>_x000D_
      <th>Left Color</th>_x000D_
      <th>Right Color</th>_x000D_
    </tr>_x000D_
  </thead>_x000D_
  <tbody>_x000D_
    <tr>_x000D_
      <td>&nbsp;</td>_x000D_
      <td>&nbsp;</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>&nbsp;</td>_x000D_
      <td>&nbsp;</td>_x000D_
    </tr>_x000D_
  </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

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

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

?#header {
    background:red;
    height:50px;
    width:100%;
    position:fixed;
    top:0;
    left:0;    
}.scroller {
    height:300px; 
    overflow:scroll;    
}

Importing a Maven project into Eclipse from Git

Eclipse Indigo + M2Eclipse 1.0 makes it very easy.

If you don't already have the Git connector for M2Eclipse install it. M2Eclipse will help you along by prompting you on the Import menu.

  1. Select the "Import..." context menu from the Package Explorer view
  2. Select "Check out Maven projects from SCM" option under the Maven category
  3. On the window that is presented choose the link "Find more SCM connectors in the m2e Marketplace
  4. Find connector for Git...install...restart

Note that in the search box you may have to enter "EGit" instead of "Git" to find the right connector.

With that done, simply go to the EGit repository, bring up the context menu for the Working directory and select "Import Maven projects...".

Done!

Add newly created specific folder to .gitignore in Git

Try /public_html/stats/* ?

But since the files in git status reported as to be commited that means you've already added them manually. In which case, of course, it's a bit too late to ignore. You can git rm --cache them (IIRC).

Finding the direction of scrolling in a UIScrollView?

Here is my solution for behavior like in @followben answer, but without loss with slow start (when dy is 0)

@property (assign, nonatomic) BOOL isFinding;
@property (assign, nonatomic) CGFloat previousOffset;

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    self.isFinding = YES;
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    if (self.isFinding) {
        if (self.previousOffset == 0) {
            self.previousOffset = self.tableView.contentOffset.y;

        } else {
            CGFloat diff = self.tableView.contentOffset.y - self.previousOffset;
            if (diff != 0) {
                self.previousOffset = 0;
                self.isFinding = NO;

                if (diff > 0) {
                    // moved up
                } else {
                    // moved down
                }
            }
        }
    }
}

VBA - If a cell in column A is not blank the column B equals

A simpler way to do this would be:

Sub populateB()

For Each Cel in Range("A1:A100")
    If Cel.value <> "" Then Cel.Offset(0, 1).value = "Your Text"
Next

End Sub

Can Selenium WebDriver open browser windows silently in the background?

Since Chrome 57 you have the headless argument:

var options = new ChromeOptions();
options.AddArguments("headless");
using (IWebDriver driver = new ChromeDriver(options))
{
    // The rest of your tests
}

The headless mode of Chrome performs 30.97% better than the UI version. The other headless driver PhantomJS delivers 34.92% better than the Chrome's headless mode.

PhantomJSDriver

using (IWebDriver driver = new PhantomJSDriver())
{
     // The rest of your test
}

The headless mode of Mozilla Firefox performs 3.68% better than the UI version. This is a disappointment since the Chrome's headless mode achieves > 30% better time than the UI one. The other headless driver PhantomJS delivers 34.92% better than the Chrome's headless mode. Surprisingly for me, the Edge browser beats all of them.

var options = new FirefoxOptions();
options.AddArguments("--headless");
{
    // The rest of your test
}

This is available from Firefox 57+

The headless mode of Mozilla Firefox performs 3.68% better than the UI version. This is a disappointment since the Chrome's headless mode achieves > 30% better time than the UI one. The other headless driver PhantomJS delivers 34.92% better than the Chrome's headless mode. Surprisingly for me, the Edge browser beats all of them.

Note: PhantomJS is not maintained any more!

Why does foo = filter(...) return a <filter object>, not a list?

Have a look at the python documentation for filter(function, iterable) (from here):

Construct an iterator from those elements of iterable for which function returns true.

So in order to get a list back you have to use list class:

shesaid = list(filter(greetings(), ["hello", "goodbye"]))

But this probably isn't what you wanted, because it tries to call the result of greetings(), which is "hello", on the values of your input list, and this won't work. Here also the iterator type comes into play, because the results aren't generated until you use them (for example by calling list() on it). So at first you won't get an error, but when you try to do something with shesaid it will stop working:

>>> print(list(shesaid))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable

If you want to check which elements in your list are equal to "hello" you have to use something like this:

shesaid = list(filter(lambda x: x == "hello", ["hello", "goodbye"]))

(I put your function into a lambda, see Randy C's answer for a "normal" function)

git - pulling from specific branch

Here is what you need to do. First make sure you are in branch that you don't want to pull. For example if you have master and develop branch, and you are trying to pull develop branch then stay in master branch.

git checkout master

Then,

git pull origin develop

Multipart File upload Spring Boot

You can simply use a controller method like this:

@RequestMapping(value = "/uploadFile", method = RequestMethod.POST)
@ResponseBody
public ResponseEntity<?> uploadFile(
    @RequestParam("file") MultipartFile file) {

  try {
    // Handle the received file here
    // ...
  }
  catch (Exception e) {
    return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
  }

  return new ResponseEntity<>(HttpStatus.OK);
} // method uploadFile

Without any additional configurations for Spring Boot.

Using the following html form client side:

<html>
<body>
  <form action="/uploadFile" method="POST" enctype="multipart/form-data">
    <input type="file" name="file">
    <input type="submit" value="Upload"> 
  </form>
</body>
</html>

If you want to set limits on files size you can do it in the application.properties:

# File size limit
multipart.maxFileSize = 3Mb

# Total request size for a multipart/form-data
multipart.maxRequestSize = 20Mb

Moreover to send the file with Ajax take a look here: http://blog.netgloo.com/2015/02/08/spring-boot-file-upload-with-ajax/

Can clearInterval() be called inside setInterval()?

Yes you can. You can even test it:

_x000D_
_x000D_
var i = 0;_x000D_
var timer = setInterval(function() {_x000D_
  console.log(++i);_x000D_
  if (i === 5) clearInterval(timer);_x000D_
  console.log('post-interval'); //this will still run after clearing_x000D_
}, 200);
_x000D_
_x000D_
_x000D_

In this example, this timer clears when i reaches 5.

Is there a way to cast float as a decimal without rounding and preserving its precision?

Have you tried:

SELECT Cast( 2.555 as decimal(53,8))

This would return 2.55500000. Is that what you want?

UPDATE:

Apparently you can also use SQL_VARIANT_PROPERTY to find the precision and scale of a value. Example:

SELECT SQL_VARIANT_PROPERTY(Cast( 2.555 as decimal(8,7)),'Precision'),
SQL_VARIANT_PROPERTY(Cast( 2.555 as decimal(8,7)),'Scale')

returns 8|7

You may be able to use this in your conversion process...

Find the paths between two given nodes?

Dijkstra's algorithm applies more to weighted paths and it sounds like the poster was wanting to find all paths, not just the shortest.

For this application, I'd build a graph (your application sounds like it wouldn't need to be directed) and use your favorite search method. It sounds like you want all paths, not just a guess at the shortest one, so use a simple recursive algorithm of your choice.

The only problem with this is if the graph can be cyclic.

With the connections:

  • 1, 2
  • 1, 3
  • 2, 3
  • 2, 4

While looking for a path from 1->4, you could have a cycle of 1 -> 2 -> 3 -> 1.

In that case, then I'd keep a stack as traversing the nodes. Here's a list with the steps for that graph and the resulting stack (sorry for the formatting - no table option):

current node (possible next nodes minus where we came from) [stack]

  1. 1 (2, 3) [1]
  2. 2 (3, 4) [1, 2]
  3. 3 (1) [1, 2, 3]
  4. 1 (2, 3) [1, 2, 3, 1] //error - duplicate number on the stack - cycle detected
  5. 3 () [1, 2, 3] // back-stepped to node three and popped 1 off the stack. No more nodes to explore from here
  6. 2 (4) [1, 2] // back-stepped to node 2 and popped 1 off the stack.
  7. 4 () [1, 2, 4] // Target node found - record stack for a path. No more nodes to explore from here
  8. 2 () [1, 2] //back-stepped to node 2 and popped 4 off the stack. No more nodes to explore from here
  9. 1 (3) [1] //back-stepped to node 1 and popped 2 off the stack.
  10. 3 (2) [1, 3]
  11. 2 (1, 4) [1, 3, 2]
  12. 1 (2, 3) [1, 3, 2, 1] //error - duplicate number on the stack - cycle detected
  13. 2 (4) [1, 3, 2] //back-stepped to node 2 and popped 1 off the stack
  14. 4 () [1, 3, 2, 4] Target node found - record stack for a path. No more nodes to explore from here
  15. 2 () [1, 3, 2] //back-stepped to node 2 and popped 4 off the stack. No more nodes
  16. 3 () [1, 3] // back-stepped to node 3 and popped 2 off the stack. No more nodes
  17. 1 () [1] // back-stepped to node 1 and popped 3 off the stack. No more nodes
  18. Done with 2 recorded paths of [1, 2, 4] and [1, 3, 2, 4]

How do I set up cron to run a file just once at a specific time?

You really want to use at. It is exactly made for this purpose.

echo /usr/bin/the_command options | at now + 1 day

However if you don't have at, or your hosting company doesn't provide access to it, you can have a cron job include code that makes sure it only runs once.

Set up a cron entry with a very specific time:

0 0 2 12 * /home/adm/bin/the_command options

Next /home/adm/bin/the_command needs to either make sure it only runs once.

#! /bin/bash

COMMAND=/home/adm/bin/the_command
DONEYET="${COMMAND}.alreadyrun"

export PATH=/usr/bin:$PATH

if [[ -f $DONEYET ]]; then
  exit 1
fi
touch "$DONEYET"

# Put the command you want to run exactly once here:
echo 'You will only get this once!' | mail -s 'Greetings!' [email protected]

IE Driver download location Link for Selenium

Use the below link to download IE Driver latest version

IE Driver

how to change namespace of entire project?

I know its quite late but for anyone looking to do it from now on, I hope this answer proves of some help. If you have CodeRush Express (free version, and a 'must have') installed, it offers a simple way to change a project wide namespace. You just place your cursor on the namespace that you want to change and it shall display a smart tag (a little blue box) underneath namespace string. You can either click that box or press Ctrl + keys to see the Rename option. Select it and then type in the new name for the project wide namespace, click Apply and select what places in your project you'd want it to change, in the new dialog and OK it. Done! :-)

Gson and deserializing an array of objects with arrays in it

The example Java data structure in the original question does not match the description of the JSON structure in the comment.

The JSON is described as

"an array of {object with an array of {object}}".

In terms of the types described in the question, the JSON translated into a Java data structure that would match the JSON structure for easy deserialization with Gson is

"an array of {TypeDTO object with an array of {ItemDTO object}}".

But the Java data structure provided in the question is not this. Instead it's

"an array of {TypeDTO object with an array of an array of {ItemDTO object}}".

A two-dimensional array != a single-dimensional array.

This first example demonstrates using Gson to simply deserialize and serialize a JSON structure that is "an array of {object with an array of {object}}".

input.json Contents:

[
  {
    "id":1,
    "name":"name1",
    "items":
    [
      {"id":2,"name":"name2","valid":true},
      {"id":3,"name":"name3","valid":false},
      {"id":4,"name":"name4","valid":true}
    ]
  },
  {
    "id":5,
    "name":"name5",
    "items":
    [
      {"id":6,"name":"name6","valid":true},
      {"id":7,"name":"name7","valid":false}
    ]
  },
  {
    "id":8,
    "name":"name8",
    "items":
    [
      {"id":9,"name":"name9","valid":true},
      {"id":10,"name":"name10","valid":false},
      {"id":11,"name":"name11","valid":false},
      {"id":12,"name":"name12","valid":true}
    ]
  }
]

Foo.java:

import java.io.FileReader;
import java.util.ArrayList;

import com.google.gson.Gson;

public class Foo
{
  public static void main(String[] args) throws Exception
  {
    Gson gson = new Gson();
    TypeDTO[] myTypes = gson.fromJson(new FileReader("input.json"), TypeDTO[].class);
    System.out.println(gson.toJson(myTypes));
  }
}

class TypeDTO
{
  int id;
  String name;
  ArrayList<ItemDTO> items;
}

class ItemDTO
{
  int id;
  String name;
  Boolean valid;
}

This second example uses instead a JSON structure that is actually "an array of {TypeDTO object with an array of an array of {ItemDTO object}}" to match the originally provided Java data structure.

input.json Contents:

[
  {
    "id":1,
    "name":"name1",
    "items":
    [
      [
        {"id":2,"name":"name2","valid":true},
        {"id":3,"name":"name3","valid":false}
      ],
      [
        {"id":4,"name":"name4","valid":true}
      ]
    ]
  },
  {
    "id":5,
    "name":"name5",
    "items":
    [
      [
        {"id":6,"name":"name6","valid":true}
      ],
      [
        {"id":7,"name":"name7","valid":false}
      ]
    ]
  },
  {
    "id":8,
    "name":"name8",
    "items":
    [
      [
        {"id":9,"name":"name9","valid":true},
        {"id":10,"name":"name10","valid":false}
      ],
      [
        {"id":11,"name":"name11","valid":false},
        {"id":12,"name":"name12","valid":true}
      ]
    ]
  }
]

Foo.java:

import java.io.FileReader;
import java.util.ArrayList;

import com.google.gson.Gson;

public class Foo
{
  public static void main(String[] args) throws Exception
  {
    Gson gson = new Gson();
    TypeDTO[] myTypes = gson.fromJson(new FileReader("input.json"), TypeDTO[].class);
    System.out.println(gson.toJson(myTypes));
  }
}

class TypeDTO
{
  int id;
  String name;
  ArrayList<ItemDTO> items[];
}

class ItemDTO
{
  int id;
  String name;
  Boolean valid;
}

Regarding the remaining two questions:

is Gson extremely fast?

Not compared to other deserialization/serialization APIs. Gson has traditionally been amongst the slowest. The current and next releases of Gson reportedly include significant performance improvements, though I haven't looked for the latest performance test data to support those claims.

That said, if Gson is fast enough for your needs, then since it makes JSON deserialization so easy, it probably makes sense to use it. If better performance is required, then Jackson might be a better choice to use. It offers much (maybe even all) of the conveniences of Gson.

Or am I better to stick with what I've got working already?

I wouldn't. I would most always rather have one simple line of code like

TypeDTO[] myTypes = gson.fromJson(new FileReader("input.json"), TypeDTO[].class);

...to easily deserialize into a complex data structure, than the thirty lines of code that would otherwise be needed to map the pieces together one component at a time.

How do I convert strings in a Pandas data frame to a 'date' data type?

Use astype

In [31]: df
Out[31]: 
   a        time
0  1  2013-01-01
1  2  2013-01-02
2  3  2013-01-03

In [32]: df['time'] = df['time'].astype('datetime64[ns]')

In [33]: df
Out[33]: 
   a                time
0  1 2013-01-01 00:00:00
1  2 2013-01-02 00:00:00
2  3 2013-01-03 00:00:00

Compare two List<T> objects for equality, ignoring order

If you want them to be really equal (i.e. the same items and the same number of each item), I think that the simplest solution is to sort before comparing:

Enumerable.SequenceEqual(list1.OrderBy(t => t), list2.OrderBy(t => t))

Edit:

Here is a solution that performs a bit better (about ten times faster), and only requires IEquatable, not IComparable:

public static bool ScrambledEquals<T>(IEnumerable<T> list1, IEnumerable<T> list2) {
  var cnt = new Dictionary<T, int>();
  foreach (T s in list1) {
    if (cnt.ContainsKey(s)) {
      cnt[s]++;
    } else {
      cnt.Add(s, 1);
    }
  }
  foreach (T s in list2) {
    if (cnt.ContainsKey(s)) {
      cnt[s]--;
    } else {
      return false;
    }
  }
  return cnt.Values.All(c => c == 0);
}

Edit 2:

To handle any data type as key (for example nullable types as Frank Tzanabetis pointed out), you can make a version that takes a comparer for the dictionary:

public static bool ScrambledEquals<T>(IEnumerable<T> list1, IEnumerable<T> list2, IEqualityComparer<T> comparer) {
  var cnt = new Dictionary<T, int>(comparer);
  ...

Are there any log file about Windows Services Status?

Through the Computer management console, navigate through Event Viewer > Windows Logs > System. Every services that change state will be logged here.

You'll see info like: The XXXX service entered the running state or The XXXX service entered the stopped state, etc.

Getting assembly name

You can use the AssemblyName class to get the assembly name, provided you have the full name for the assembly:

AssemblyName.GetAssemblyName(Assembly.GetExecutingAssembly().FullName).Name

or

AssemblyName.GetAssemblyName(e.Source).Name

MSDN Reference - AssemblyName Class

std::vector versus std::array in C++

To emphasize a point made by @MatteoItalia, the efficiency difference is where the data is stored. Heap memory (required with vector) requires a call to the system to allocate memory and this can be expensive if you are counting cycles. Stack memory (possible for array) is virtually "zero-overhead" in terms of time, because the memory is allocated by just adjusting the stack pointer and it is done just once on entry to a function. The stack also avoids memory fragmentation. To be sure, std::array won't always be on the stack; it depends on where you allocate it, but it will still involve one less memory allocation from the heap compared to vector. If you have a

  • small "array" (under 100 elements say) - (a typical stack is about 8MB, so don't allocate more than a few KB on the stack or less if your code is recursive)
  • the size will be fixed
  • the lifetime is in the function scope (or is a member value with the same lifetime as the parent class)
  • you are counting cycles,

definitely use a std::array over a vector. If any of those requirements is not true, then use a std::vector.

How to Convert Boolean to String

Just wanted to update, in PHP >= 5.50 you can do boolval() to do the same thing

Reference Here.

Converting a date string to a DateTime object using Joda Time library

Use DateTimeFormat:

DateTimeFormatter formatter = DateTimeFormat.forPattern("dd/MM/yyyy HH:mm:ss");
DateTime dt = formatter.parseDateTime(string);

How to send an HTTP request using Telnet

You could do

telnet stackoverflow.com 80

And then paste

GET /questions HTTP/1.0
Host: stackoverflow.com


# add the 2 empty lines above but not this one

Here is a transcript

$ telnet stackoverflow.com 80
Trying 151.101.65.69...
Connected to stackoverflow.com.
Escape character is '^]'.
GET /questions HTTP/1.0
Host: stackoverflow.com

HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
...

Rename master branch for both local and remote Git repositories

git checkout -b new-branch-name
git push remote-name new-branch-name :old-branch-name

You may have to manually switch to new-branch-name before deleting old-branch-name

How do I assign a null value to a variable in PowerShell?

Use $dec = $null

From the documentation:

$null is an automatic variable that contains a NULL or empty value. You can use this variable to represent an absent or undefined value in commands and scripts.

PowerShell treats $null as an object with a value, that is, as an explicit placeholder, so you can use $null to represent an empty value in a series of values.

jQuery: Change button text on click

This should work for you:

    $('.SeeMore2').click(function(){
        var $this = $(this);
        $this.toggleClass('SeeMore2');
        if($this.hasClass('SeeMore2')){
            $this.text('See More');         
        } else {
            $this.text('See Less');
        }
});

How can I get the application's path in a .NET console application?

If you are looking for a .NET Core compatible way, use

System.AppContext.BaseDirectory

This was introduced in .NET Framework 4.6 and .NET Core 1.0 (and .NET Standard 1.3). See: AppContext.BaseDirectory Property.

According to this page,

This is the prefered replacement for AppDomain.CurrentDomain.BaseDirectory in .NET Core

PHP preg_replace special characters

do this in two steps:

  1. replace not letter characters with this regex:

    [\/\&%#\$]

  2. replace quotes with this regex:

    [\"\']

and use preg_replace:

$stringWithoutNonLetterCharacters = preg_replace("/[\/\&%#\$]/", "_", $yourString);
$stringWithQuotesReplacedWithSpaces = preg_replace("/[\"\']/", " ", $stringWithoutNonLetterCharacters);

API Gateway CORS: no 'Access-Control-Allow-Origin' header

In Python you can do it as in the code below:

{ "statusCode" : 200,
'headers': 
    {'Content-Type': 'application/json',
    'Access-Control-Allow-Origin': "*"
     },
"body": json.dumps(
    {
    "temperature" : tempArray,
    "time": timeArray
    })
 }

Understanding Matlab FFT example

It sounds like you need to some background reading on what an FFT is (e.g. http://en.wikipedia.org/wiki/FFT). But to answer your questions:

Why does the x-axis (frequency) end at 500?

Because the input vector is length 1000. In general, the FFT of a length-N input waveform will result in a length-N output vector. If the input waveform is real, then the output will be symmetrical, so the first 501 points are sufficient.

Edit: (I didn't notice that the example padded the time-domain vector.)

The frequency goes to 500 Hz because the time-domain waveform is declared to have a sample-rate of 1 kHz. The Nyquist sampling theorem dictates that a signal with sample-rate fs can support a (real) signal with a maximum bandwidth of fs/2.

How do I know the frequencies are between 0 and 500?

See above.

Shouldn't the FFT tell me, in which limits the frequencies are?

No.

Does the FFT only return the amplitude value without the frequency?

The FFT simply assigns an amplitude (and phase) to every frequency bin.

How to run Pip commands from CMD

Little side note for anyone new to Python who didn't figure it out by theirself: this should be automatic when installing Python, but just in case, note that to run Python using the python command in Windows' CMD you must first add it to the PATH environment variable, as explained here.


To execute Pip, first of all make sure you have it installed, so type in your CMD:

> python
>>> import pip
>>>

And it should proceed with no error. Otherwise, if this fails, you can look here to see how to install it. Now that you are sure you've got Pip, you can run it from CMD with Python using the -m (module) parameter, like this:

> python -m pip <command> <args>

Where <command> is any Pip command you want to run, and <args> are its relative arguments, separated by spaces.

For example, to install a package:

> python -m pip install <package-name>

How to preserve insertion order in HashMap?

HashMap is unordered per the second line of the documentation:

This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.

Perhaps you can do as aix suggests and use a LinkedHashMap, or another ordered collection. This link can help you find the most appropriate collection to use.

go to character in vim

vim +21490go script.py

From the command line will open the file and take you to position 21490 in the buffer.

Triggering it from the command line like this allows you to automate a script to parse the exception message and open the file to the problem position.


Excerpt from man vim:

+{command}

-c {command}

{command} will be executed after the first file has been read. {command} is interpreted as an Ex command. If the {command} contains spaces it must be enclosed in double quotes (this depends on the shell that is used).

WPF Databinding: How do I access the "parent" data context?

This will also work:

<Hyperlink Command="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl},
                             Path=DataContext.AllowItemCommand}" />

ListView will inherit its DataContext from Window, so it's available at this point, too.
And since ListView, just like similar controls (e. g. Gridview, ListBox, etc.), is a subclass of ItemsControl, the Binding for such controls will work perfectly.

How to edit incorrect commit message in Mercurial?

Rollback-and-reapply is realy simple solution, but it can help only with the last commit. Mercurial Queues is much more powerful thing (note that you need to enable Mercurial Queues Extension in order to use "hg q*" commands).

Count number of tables in Oracle

These documents describe data dictionary views:

all_tables: http://docs.oracle.com/cd/B19306_01/server.102/b14237/statviews_4473.htm#REFRN26286

user_tables: http://docs.oracle.com/cd/B19306_01/server.102/b14237/statviews_2105.htm#i1592091

dba_tables: http://docs.oracle.com/cd/B19306_01/server.102/b14237/statviews_4155.htm#i1627762

You can run queries on these views to count what you need.

To add something more to @Anurag Thakre's answer:

Use this query which will give you the actual no of counts respect to the owners

SELECT COUNT(*),tablespace_name  FROM USER_TABLES group by tablespace_name;

Or by table owners:

SELECT COUNT(*), owner  FROM ALL_TABLES group by owner;

Tablespace itself does not identify an unique object owner. Multiple users can create objects in the same tablespace and a single user can create objects in various tablespaces. It is a common practice to separate tables and indexes into different tablespaces.

Anaconda site-packages

I encountered this issue in my conda environment. The reason is that packages have been installed into two different folders, only one of which is recognised by the Python executable.

~/anaconda2/envs/[my_env]/site-packages ~/anaconda2/envs/[my_env]/lib/python2.7/site-packages

A proved solution is to add both folders to python path, using the following steps in command line (Please replace [my_env] with your own environment):

  1. conda activate [my_env].
  2. conda-develop ~/anaconda2/envs/[my_env]/site-packages
  3. conda-develop ~/anaconda2/envs/[my_env]/lib/python2.7/site-packages (conda-develop is to add a .pth file to the folder so that the Python executable knows of this folder when searching for packages.)

To ensure this works, try to activate Python in this environment, and import the package that was not found.

Detecting iOS orientation change instantly

Why you didn`t use

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

?

Or you can use this

-(void) willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration

Or this

-(void) didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation

Hope it owl be useful )

How to convert Hexadecimal #FFFFFF to System.Drawing.Color

You can do

var color =  System.Drawing.ColorTranslator.FromHtml("#FFFFFF");

Or this (you will need the System.Windows.Media namespace)

var color = (Color)ColorConverter.ConvertFromString("#FFFFFF");

How to pretty print nested dictionaries?

This is what I came up with while working on a class that needed to write a dictionary in a .txt file:

@staticmethod
def _pretty_write_dict(dictionary):

    def _nested(obj, level=1):
        indentation_values = "\t" * level
        indentation_braces = "\t" * (level - 1)
        if isinstance(obj, dict):
            return "{\n%(body)s%(indent_braces)s}" % {
                "body": "".join("%(indent_values)s\'%(key)s\': %(value)s,\n" % {
                    "key": str(key),
                    "value": _nested(value, level + 1),
                    "indent_values": indentation_values
                } for key, value in obj.items()),
                "indent_braces": indentation_braces
            }
        if isinstance(obj, list):
            return "[\n%(body)s\n%(indent_braces)s]" % {
                "body": "".join("%(indent_values)s%(value)s,\n" % {
                    "value": _nested(value, level + 1),
                    "indent_values": indentation_values
                } for value in obj),
                "indent_braces": indentation_braces
            }
        else:
            return "\'%(value)s\'" % {"value": str(obj)}

    dict_text = _nested(dictionary)
    return dict_text

Now, if we have a dictionary like this:

some_dict = {'default': {'ENGINE': [1, 2, 3, {'some_key': {'some_other_key': 'some_value'}}], 'NAME': 'some_db_name', 'PORT': '', 'HOST': 'localhost', 'USER': 'some_user_name', 'PASSWORD': 'some_password', 'OPTIONS': {'init_command': 'SET foreign_key_checks = 0;'}}}

And we do:

print(_pretty_write_dict(some_dict))

We get:

{
    'default': {
        'ENGINE': [
            '1',
            '2',
            '3',
            {
                'some_key': {
                    'some_other_key': 'some_value',
                },
            },
        ],
        'NAME': 'some_db_name',
        'OPTIONS': {
            'init_command': 'SET foreign_key_checks = 0;',
        },
        'HOST': 'localhost',
        'USER': 'some_user_name',
        'PASSWORD': 'some_password',
        'PORT': '',
    },
}

python list by value not by reference

To copy a list you can use list(a) or a[:]. In both cases a new object is created.
These two methods, however, have limitations with collections of mutable objects as inner objects keep their references intact:

>>> a = [[1,2],[3],[4]]

>>> b = a[:]
>>> c = list(a)

>>> c[0].append(9)

>>> a
[[1, 2, 9], [3], [4]]
>>> c
[[1, 2, 9], [3], [4]]
>>> b
[[1, 2, 9], [3], [4]]
>>> 

If you want a full copy of your objects you need copy.deepcopy

>>> from copy import deepcopy
>>> a = [[1,2],[3],[4]]

>>> b = a[:]
>>> c = deepcopy(a)

>>> c[0].append(9)

>>> a
[[1, 2], [3], [4]]
>>> b
[[1, 2], [3], [4]]
>>> c
[[1, 2, 9], [3], [4]]
>>> 

What port is a given program using?

On Vista, you do need elevated privileges to use the -b option with netstat. To get around that, you could run "netstat -ano" which will show all open ports along with the associated process id. You could then use tasklist to lookup which process has the corresponding id.

C:\>netstat -ano

Active Connections

  Proto  Local Address          Foreign Address        State           PID
  ...
  TCP    [::]:49335             [::]:0                 LISTENING       1056
  ...

C:\>tasklist /fi "pid eq 1056"

Image Name                     PID Session Name        Session#    Mem Usage
========================= ======== ================ =========== ============
sqlservr.exe                  1056 Services                   0     66,192 K

How to implement endless list with RecyclerView?

This is how I do it, simple and short:

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener()
    {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy)
        {
            if(!recyclerView.canScrollVertically(1) && dy != 0)
            {
                // Load more results here

            }
        }
    });

Cleaning `Inf` values from an R dataframe

Feng Mai has a tidyverse answer above to get negative and positive infinities:

dat %>% mutate_if(is.numeric, list(~na_if(., Inf))) %>% 
  mutate_if(is.numeric, list(~na_if(., -Inf)))

This works well, but a word of warning is not to swap in abs(.) here to do both lines at once as is proposed in an upvoted comment. It will look like it works, but changes all negative values in the dataset to positive! You can confirm with this:

data(iris)
#The last line here is bad - it converts all negative values to positive
iris %>% 
  mutate_if(is.numeric, ~scale(.)) %>%
  mutate(infinities = Sepal.Length / 0) %>%
  mutate_if(is.numeric, list(~na_if(abs(.), Inf)))

For one line, this works:

  mutate_if(is.numeric, ~ifelse(abs(.) == Inf,NA,.))

How do I mount a remote Linux folder in Windows through SSH?

Dokan looks like a FUSE and sshfs implementation for Windows. If it works as expected and advertised, it would do exactly what you are looking for.

(Link updated and working 2015-10-15)

What is the difference between . (dot) and $ (dollar sign)?

All the other answers are pretty good. But there’s an important usability detail about how ghc treats $, that the ghc type checker allows for instatiarion with higher rank/ quantified types. If you look at the type of $ id for example you’ll find it’s gonna take a function whose argument is itself a polymorphic function. Little things like that aren’t given the same flexibility with an equivalent upset operator. (This actually makes me wonder if $! deserves the same treatment or not )

How to get a list column names and datatypes of a table in PostgreSQL?

SELECT
        a.attname as "Column",
        pg_catalog.format_type(a.atttypid, a.atttypmod) as "Datatype"
    FROM
        pg_catalog.pg_attribute a
    WHERE
        a.attnum > 0
        AND NOT a.attisdropped
        AND a.attrelid = (
            SELECT c.oid
            FROM pg_catalog.pg_class c
                LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
            WHERE c.relname ~ '^(hello world)$'
                AND pg_catalog.pg_table_is_visible(c.oid)
        );

Change the hello world with your table name

More info on it : http://www.postgresql.org/docs/9.3/static/catalog-pg-attribute.html

Java Does Not Equal (!=) Not Working?

== and != work on object identity. While the two Strings have the same value, they are actually two different objects.

use !"success".equals(statusCheck) instead.

How to remove element from array in forEach loop?

Here is how you should do it:

review.forEach(function(p,index,object){
   if(review[index] === '\u2022 \u2022 \u2022'){
      console.log('YippeeeE!!!!!!!!!!!!!!!!')
      review.splice(index, 1);
   }
});

Bootstrap 3 - 100% height of custom div inside column

You need to set the height of every parent element of the one you want the height defined.

<html style="height: 100%;">
  <body style="height: 100%;">
    <div style="height: 100%;">
      <p>
        Make this division 100% height.
      </p>
    </div>
  </body>
</html>

Article.

JsFiddle example

No Exception while type casting with a null in java

Casting null values is required for following construct where a method is overloaded and if null is passed to these overloaded methods then the compiler does not know how to clear up the ambiguity hence we need to typecast null in these cases:

class A {
  public void foo(Long l) {
    // do something with l
  }
  public void foo(String s) {
    // do something with s      
  }
}
new A().foo((String)null);
new A().foo((Long)null);

Otherwise you couldn't call the method you need.

JQuery: if div is visible

You can use .is(':visible')

Selects all elements that are visible.

For example:

if($('#selectDiv').is(':visible')){

Also, you can get the div which is visible by:

$('div:visible').callYourFunction();

Live example:

_x000D_
_x000D_
console.log($('#selectDiv').is(':visible'));_x000D_
console.log($('#visibleDiv').is(':visible'));
_x000D_
#selectDiv {_x000D_
  display: none;  _x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="selectDiv"></div>_x000D_
<div id="visibleDiv"></div>
_x000D_
_x000D_
_x000D_

Create a jTDS connection string

A shot in the dark, but From the looks of your error message, it seems that either the sqlserver instance is not running on port 1433 or something is blocking the requests to that port

Excel: Search for a list of strings within a particular string using array formulas?

In case others may find this useful: I found that by adding an initial empty cell to my list of search terms, a zero value will be returned instead of error.

={INDEX(SearchTerms!$A$1:$A$38,MAX(IF(ISERROR(SEARCH(SearchTerms!$A$1:$A$38,SearchCell)),0,1)*((SearchTerms!$B$1:$B$38)+1)))}

NB: Column A has the search terms, B is the row number index.

PHP "php://input" vs $_POST

So I wrote a function that would get the POST data from the php://input stream.

So the challenge here was switching to PUT, DELETE OR PATCH request method, and still obtain the post data that was sent with that request.

I'm sharing this maybe for someone with a similar challenge. The function below is what I came up with and it works. I hope it helps!

    /**
     * @method Post getPostData
     * @return array
     * 
     * Convert Content-Disposition to a post data
     */
    function getPostData() : array
    {
        // @var string $input
        $input = file_get_contents('php://input');

        // continue if $_POST is empty
        if (strlen($input) > 0 && count($_POST) == 0 || count($_POST) > 0) :

            $postsize = "---".sha1(strlen($input))."---";

            preg_match_all('/([-]{2,})([^\s]+)[\n|\s]{0,}/', $input, $match);

            // update input
            if (count($match) > 0) $input = preg_replace('/([-]{2,})([^\s]+)[\n|\s]{0,}/', '', $input);

            // extract the content-disposition
            preg_match_all("/(Content-Disposition: form-data; name=)+(.*)/m", $input, $matches);

            // let's get the keys
            if (count($matches) > 0 && count($matches[0]) > 0)
            {
                $keys = $matches[2];

                foreach ($keys as $index => $key) :
                    $key = trim($key);
                    $key = preg_replace('/^["]/','',$key);
                    $key = preg_replace('/["]$/','',$key);
                    $key = preg_replace('/[\s]/','',$key);
                    $keys[$index] = $key;
                endforeach;

                $input = preg_replace("/(Content-Disposition: form-data; name=)+(.*)/m", $postsize, $input);

                $input = preg_replace("/(Content-Length: )+([^\n]+)/im", '', $input);

                // now let's get key value
                $inputArr = explode($postsize, $input);

                // @var array $values
                $values = [];

                foreach ($inputArr as $index => $val) :
                    $val = preg_replace('/[\n]/','',$val);

                    if (preg_match('/[\S]/', $val)) $values[$index] = trim($val);

                endforeach;

                // now combine the key to the values
                $post = [];

                // @var array $value
                $value = [];

                // update value
                foreach ($values as $i => $val) $value[] = $val;

                // push to post
                foreach ($keys as $x => $key) $post[$key] = isset($value[$x]) ? $value[$x] : '';

                if (is_array($post)) :

                    $newPost = [];

                    foreach ($post as $key => $val) :

                        if (preg_match('/[\[]/', $key)) :

                            $k = substr($key, 0, strpos($key, '['));
                            $child = substr($key, strpos($key, '['));
                            $child = preg_replace('/[\[|\]]/','', $child);
                            $newPost[$k][$child] = $val;

                        else:

                            $newPost[$key] = $val;

                        endif;

                    endforeach;

                    $_POST = count($newPost) > 0 ? $newPost : $post;

                endif;
            }

        endif;

        // return post array
        return $_POST;
    }

Initializing select with AngularJS and ng-repeat

The fact that angular is injecting an empty option element to the select is that the model object binded to it by default comes with an empty value in when initialized.

If you want to select a default option then you can probably can set it on the scope in the controller

$scope.filterCondition.operator = "your value here";

If you want to an empty option placeholder, this works for me

<select ng-model="filterCondition.operator" ng-options="operator.id as operator.name for operator in operators">
  <option value="">Choose Operator</option>
</select>

JavaFX FXML controller - constructor vs initialize method

The initialize method is called after all @FXML annotated members have been injected. Suppose you have a table view you want to populate with data:

class MyController { 
    @FXML
    TableView<MyModel> tableView; 

    public MyController() {
        tableView.getItems().addAll(getDataFromSource()); // results in NullPointerException, as tableView is null at this point. 
    }

    @FXML
    public void initialize() {
        tableView.getItems().addAll(getDataFromSource()); // Perfectly Ok here, as FXMLLoader already populated all @FXML annotated members. 
    }
}

What is the problem with shadowing names defined in outer scopes?

It looks like it is 100% a pytest code pattern.

See:

pytest fixtures: explicit, modular, scalable

I had the same problem with it, and this is why I found this post ;)

# ./tests/test_twitter1.py
import os
import pytest

from mylib import db
# ...

@pytest.fixture
def twitter():
    twitter_ = db.Twitter()
    twitter_._debug = True
    return twitter_

@pytest.mark.parametrize("query,expected", [
    ("BANCO PROVINCIAL", 8),
    ("name", 6),
    ("castlabs", 42),
])
def test_search(twitter: db.Twitter, query: str, expected: int):

    for query in queries:
        res = twitter.search(query)
        print(res)
        assert res

And it will warn with This inspection detects shadowing names defined in outer scopes.

To fix that, just move your twitter fixture into ./tests/conftest.py

# ./tests/conftest.py
import pytest

from syntropy import db


@pytest.fixture
def twitter():
    twitter_ = db.Twitter()
    twitter_._debug = True
    return twitter_

And remove the twitter fixture, like in ./tests/test_twitter2.py:

# ./tests/test_twitter2.py
import os
import pytest

from mylib import db
# ...

@pytest.mark.parametrize("query,expected", [
    ("BANCO PROVINCIAL", 8),
    ("name", 6),
    ("castlabs", 42),
])
def test_search(twitter: db.Twitter, query: str, expected: int):

    for query in queries:
        res = twitter.search(query)
        print(res)
        assert res

This will be make happy for QA, PyCharm and everyone.

How do I create a user with the same privileges as root in MySQL/MariaDB?

% mysql --user=root mysql
CREATE USER 'monty'@'localhost' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost' WITH GRANT OPTION;
CREATE USER 'monty'@'%' IDENTIFIED BY 'some_pass';
GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%' WITH GRANT OPTION;
CREATE USER 'admin'@'localhost';
GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
CREATE USER 'dummy'@'localhost';
FLUSH PRIVILEGES;

How can I echo the whole content of a .html file in PHP?

You should use readfile():

readfile("/path/to/file");

This will read the file and send it to the browser in one command. This is essentially the same as:

echo file_get_contents("/path/to/file");

except that file_get_contents() may cause the script to crash for large files, while readfile() won't.

Remove a fixed prefix/suffix from a string in Bash

I would make use of capture groups in regex:

$ string="hello-world"
$ prefix="hell"
$ suffix="ld"
$ set +H # Disables history substitution, can be omitted in scripts.
$ perl -pe "s/${prefix}((?:(?!(${suffix})).)*)${suffix}/\1/" <<< $string
o-wor
$ string1=$string$string
$ perl -pe "s/${prefix}((?:(?!(${suffix})).)*)${suffix}/\1/g" <<< $string1
o-woro-wor

((?:(?!(${suffix})).)*) makes sure that the content of ${suffix} will be excluded from the capture group. In terms of example, it's the string equivalent to [^A-Z]*. Otherwise you will get:

$ perl -pe "s/${prefix}(.*)${suffix}/\1/g" <<< $string1
o-worldhello-wor

How do I tell Spring Boot which main class to use for the executable jar?

For those using Gradle (instead of Maven) :

springBoot {
    mainClass = "com.example.Main"
}

Issue when importing dataset: `Error in scan(...): line 1 did not have 145 elements`

I have faced same issue while trying to read data from file in R. After figuring out I found out that sep value is causing this issue. Once I tried this with correct separator it was working as expected.

read.table("file_location/file_name",
    sep="." # exact separator as given in file: also "," or "\t" etc.
    col_names=c("name_1", "name_2",..))

How to send Basic Auth with axios

The reason the code in your question does not authenticate is because you are sending the auth in the data object, not in the config, which will put it in the headers. Per the axios docs, the request method alias for post is:

axios.post(url[, data[, config]])

Therefore, for your code to work, you need to send an empty object for data:

var session_url = 'http://api_address/api/session_endpoint';
var username = 'user';
var password = 'password';
var basicAuth = 'Basic ' + btoa(username + ':' + password);
axios.post(session_url, {}, {
  headers: { 'Authorization': + basicAuth }
}).then(function(response) {
  console.log('Authenticated');
}).catch(function(error) {
  console.log('Error on Authentication');
});

The same is true for using the auth parameter mentioned by @luschn. The following code is equivalent, but uses the auth parameter instead (and also passes an empty data object):

var session_url = 'http://api_address/api/session_endpoint';
var uname = 'user';
var pass = 'password';
axios.post(session_url, {}, {
  auth: {
    username: uname,
    password: pass
  }
}).then(function(response) {
  console.log('Authenticated');
}).catch(function(error) {
  console.log('Error on Authentication');
});

Eclipse: All my projects disappeared from Project Explorer

I had the same problem in Luna,

Suddenly my projects were gone in start-up.
I solved this by select Deselect working set option in the drop-down menu in Project Explorer.

Note: I post this answer even this is not a right answer for this question. Since I search for Luna and came here,while trying with discussed things I was find this solution. This may help others.

How to add new activity to existing project in Android Studio?

I think natually do it is straightforward, whether Intellij IDEA or Android Studio, I always click new Java class menu, and then typing the class name, press Enter to create. after that, I manually typing "extends Activity" in the class file, and then import the class by shortcut key. finally, I also manually override the onCreate() method and invoke the setContentView() method.

How do you reverse a string in place in C or C++?

Recursive function to reverse a string in place (no extra buffer, malloc).

Short, sexy code. Bad, bad stack usage.

#include <stdio.h>

/* Store the each value and move to next char going down
 * the stack. Assign value to start ptr and increment 
 * when coming back up the stack (return).
 * Neat code, horrible stack usage.
 *
 * val - value of current pointer.
 * s - start pointer
 * n - next char pointer in string.
 */
char *reverse_r(char val, char *s, char *n)
{
    if (*n)
        s = reverse_r(*n, s, n+1);
   *s = val;
   return s+1;
}

/*
 * expect the string to be passed as argv[1]
 */
int main(int argc, char *argv[])
{
    char *aString;

    if (argc < 2)
    {
        printf("Usage: RSIP <string>\n");
        return 0;
    }

    aString = argv[1];
    printf("String to reverse: %s\n", aString );

    reverse_r(*aString, aString, aString+1); 
    printf("Reversed String:   %s\n", aString );

    return 0;
}

FULL OUTER JOIN vs. FULL JOIN

It's true that some databases recognize the OUTER keyword. Some do not. Where it is recognized, it is usually an optional keyword. Almost always, FULL JOIN and FULL OUTER JOIN do exactly the same thing. (I can't think of an example where they do not. Can anyone else think of one?)

This may leave you wondering, "Why would it even be a keyword if it has no meaning?" The answer boils down to programming style.

In the old days, programmers strived to make their code as compact as possible. Every character meant longer processing time. We used 1, 2, and 3 letter variables. We used 2 digit years. We eliminated all unnecessary white space. Some people still program that way. It's not about processing time anymore. It's more about fast coding.

Modern programmers are learning to use more descriptive variables and put more remarks and documentation into their code. Using extra words like OUTER make sure that other people who read the code will have an easier time understanding it. There will be less ambiguity. This style is much more readable and kinder to the people in the future who will have to maintain that code.

CMake error at CMakeLists.txt:30 (project): No CMAKE_C_COMPILER could be found

Look in the Cmakelists.txt if you find ARM you need to install C++ for ARM

It's these packages:

C++ Universal Windows Platform for ARM64 "Not Required"

Visual C++ Compilers and libraries for ARM "Not Required"

Visual C++ Compilers and libraries for ARM64 "Very Likely Required"

Required for finding Threads on ARM 
enable_language(C) 
enable_language(CXX)

Then the problems

No CMAKE_C_COMPILER could be found.

No CMAKE_CXX_COMPILER could be found.

Might disappear unless you specify c compiler like clang, and maybe installing clang will work in other favour.

You can with optional remove in cmakelists.txt both with # before enable_language if you are not compiling for ARM.

How can I find the dimensions of a matrix in Python?

m = [[1, 1, 1, 0],[0, 5, 0, 1],[2, 1, 3, 10]]

print(len(m),len(m[0]))

Output

(3 4)

Postgres user does not exist?

psql: Logs me in with my default username

psql -U postgres: Logs me in as the postgres user

Sudo doesn't seem to be required for me.

I use Postgres.app for my OS X postgres database. It removed the headache of making sure the installation was working and the database server was launched properly. Check it out here: http://postgresapp.com

Edit: Credit to @Erwin Brandstetter for correcting my use of the arguments.

How to force the browser to reload cached CSS and JavaScript files

If you are using jQuery, there is an option called cache that will append a random number.

This is not a complete answer I know, but it might save you some time.

What is the difference between res.end() and res.send()?

I would like to make a little bit more emphasis on some key differences between res.end() & res.send() with respect to response headers and why they are important.

1. res.send() will check the structure of your output and set header information accordingly.


    app.get('/',(req,res)=>{
       res.send('<b>hello</b>');
    });

enter image description here


     app.get('/',(req,res)=>{
         res.send({msg:'hello'});
     });

enter image description here

Where with res.end() you can only respond with text and it will not set "Content-Type"

      app.get('/',(req,res)=>{
           res.end('<b>hello</b>');
      }); 

enter image description here

2. res.send() will set "ETag" attribute in the response header

      app.get('/',(req,res)=>{
            res.send('<b>hello</b>');
      });

enter image description here

¿Why is this tag important?
The ETag HTTP response header is an identifier for a specific version of a resource. It allows caches to be more efficient, and saves bandwidth, as a web server does not need to send a full response if the content has not changed.

res.end() will NOT set this header attribute

Add Favicon to Website

Simply put a file named favicon.ico in the webroot.

If you want to know more, please start reading:

Please run `npm cache clean`

As of npm@5, the npm cache self-heals from corruption issues and data extracted from the cache is guaranteed to be valid. If you want to make sure everything is consistent, use npm cache verify instead. On the other hand, if you're debugging an issue with the installer, you can use npm install --cache /tmp/empty-cache to use a temporary cache instead of nuking the actual one.

If you're sure you want to delete the entire cache, rerun:

npm cache clean --force

A complete log of this run can be found in /Users/USERNAME/.npm/_logs/2019-01-08T21_29_30_811Z-debug.log.

How do you specify a different port number in SQL Management Studio?

127.0.0.1,6283

Add a comma between the ip and port

"Could not find acceptable representation" using spring-boot-starter-web

I was running into the same issue, and what I was missing in my setup was including this in my maven (pom.xml) file.

<dependency>
     <groupId>org.codehaus.jackson</groupId>
     <artifactId>jackson-mapper-asl</artifactId>
     <version>1.9.9</version>
</dependency> 

How can I create Min stl priority_queue?

Based on above all answers I created an example code for how to create priority queue. Note: It works C++11 and above compilers

#include <iostream>
#include <vector>
#include <iomanip>
#include <queue>

using namespace std;

// template for prirority Q
template<class T> using min_heap = priority_queue<T, std::vector<T>, std::greater<T>>;
template<class T> using max_heap = priority_queue<T, std::vector<T>>;

const int RANGE = 1000;

vector<int> get_sample_data(int size);

int main(){
  int n;
  cout << "Enter number of elements N = " ; cin >> n;
  vector<int> dataset = get_sample_data(n);

  max_heap<int> max_pq;
  min_heap<int> min_pq;

  // Push data to Priority Queue
  for(int i: dataset){
    max_pq.push(i);
    min_pq.push(i);
  }

  while(!max_pq.empty() && !min_pq.empty()){
    cout << setw(10) << min_pq.top()<< " | " << max_pq.top() << endl;
    min_pq.pop();
    max_pq.pop();
  }

}


vector<int> get_sample_data(int size){
  srand(time(NULL));
  vector<int> dataset;
  for(int i=0; i<size; i++){
    dataset.push_back(rand()%RANGE);
  }
  return dataset;
}

Output of Above code

Enter number of elements N = 4

        33 | 535
        49 | 411
       411 | 49
       535 | 33

How to set dialog to show in full screen?

EDIT Until such time as StackOverflow allows us to version our answers, this is an answer that works for Android 3 and below. Please don't downvote it because it's not working for you now, because it definitely works with older Android versions.


You should only need to add one line to your onCreateDialog() method:

@Override
protected Dialog onCreateDialog(int id) {
    //all other dialog stuff (which dialog to display)

    //this line is what you need:
    dialog.getWindow().setFlags(LayoutParams.FLAG_FULLSCREEN, LayoutParams.FLAG_FULLSCREEN);

    return dialog;
}

How can I generate a 6 digit unique number?

This will generate random 6 digit number

_x000D_
_x000D_
<?php_x000D_
    mt_rand(100000,999999);_x000D_
?>
_x000D_
_x000D_
_x000D_

CSS: fixed to bottom and centered

There are 2 potential issues that I see:

1 - IE has had trouble with position:fixed in the past. If you are using IE7+ with a valid doctype or a non-IE browser this isn't part of the problem

2 - You need to specify a width for the footer if you want the footer object to be centered. Otherwise it defaults to the full width of the page and the auto margin for the left and right get set to 0. If you want the footer bar to take up the width (like the StackOverflow notice bar) and center the text, then you need to add "text-align: center" to your definition.

How to parse XML in Bash?

Command-line tools that can be called from shell scripts include:

  • 4xpath - command-line wrapper around Python's 4Suite package

  • XMLStarlet

  • xpath - command-line wrapper around Perl's XPath library

    sudo apt-get install libxml-xpath-perl
    
  • Xidel - Works with URLs as well as files. Also works with JSON

I also use xmllint and xsltproc with little XSL transform scripts to do XML processing from the command line or in shell scripts.

How can I make a countdown with NSTimer?

this for the now swift 5.0 and newst

var secondsRemaining = 60


Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(updateCounter), userInfo: nil, repeats: true)
}
@objc func updateCounter(){
    if secondsRemaining > 0 {
    print("\(secondsRemaining) seconds.")
    secondsRemaining -= 1
            }
        }

Correct way of getting Client's IP Addresses from http.Request

Here a completely working example

package main

import (  
    // Standard library packages
    "fmt"
    "strconv"
    "log"
    "net"
    "net/http"

    // Third party packages
    "github.com/julienschmidt/httprouter"
    "github.com/skratchdot/open-golang/open"
)



// https://blog.golang.org/context/userip/userip.go
func getIP(w http.ResponseWriter, req *http.Request, _ httprouter.Params){
    fmt.Fprintf(w, "<h1>static file server</h1><p><a href='./static'>folder</p></a>")

    ip, port, err := net.SplitHostPort(req.RemoteAddr)
    if err != nil {
        //return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)

        fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
    }

    userIP := net.ParseIP(ip)
    if userIP == nil {
        //return nil, fmt.Errorf("userip: %q is not IP:port", req.RemoteAddr)
        fmt.Fprintf(w, "userip: %q is not IP:port", req.RemoteAddr)
        return
    }

    // This will only be defined when site is accessed via non-anonymous proxy
    // and takes precedence over RemoteAddr
    // Header.Get is case-insensitive
    forward := req.Header.Get("X-Forwarded-For")

    fmt.Fprintf(w, "<p>IP: %s</p>", ip)
    fmt.Fprintf(w, "<p>Port: %s</p>", port)
    fmt.Fprintf(w, "<p>Forwarded for: %s</p>", forward)
}


func main() {  
    myport := strconv.Itoa(10002);


    // Instantiate a new router
    r := httprouter.New()

    r.GET("/ip", getIP)

    // Add a handler on /test
    r.GET("/test", func(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
        // Simply write some test data for now
        fmt.Fprint(w, "Welcome!\n")
    })  


    l, err := net.Listen("tcp", "localhost:" + myport)
    if err != nil {
        log.Fatal(err)
    }
    // The browser can connect now because the listening socket is open.


    //err = open.Start("http://localhost:"+ myport + "/test")
    err = open.Start("http://localhost:"+ myport + "/ip")
    if err != nil {
         log.Println(err)
    }

    // Start the blocking server loop.
    log.Fatal(http.Serve(l, r)) 
}

Force div element to stay in same place, when page is scrolled

There is something wrong with your code.

position : absolute makes the element on top irrespective of other elements in the same page. But the position not relative to the scroll

This can be solved with position : fixed This property will make the element position fixed and still relative to the scroll.

Or

You can check it out Here

Linux command to translate DomainName to IP

Use this

$ dig +short stackoverflow.com

69.59.196.211

or this

$ host stackoverflow.com

stackoverflow.com has address 69.59.196.211
stackoverflow.com mail is handled by 30 alt2.aspmx.l.google.com.
stackoverflow.com mail is handled by 40 aspmx2.googlemail.com.
stackoverflow.com mail is handled by 50 aspmx3.googlemail.com.
stackoverflow.com mail is handled by 10 aspmx.l.google.com.
stackoverflow.com mail is handled by 20 alt1.aspmx.l.google.com.

Static variables in C++

Static variable in a header file:

say 'common.h' has

static int zzz;

This variable 'zzz' has internal linkage (This same variable can not be accessed in other translation units). Each translation unit which includes 'common.h' has it's own unique object of name 'zzz'.

Static variable in a class:

Static variable in a class is not a part of the subobject of the class. There is only one copy of a static data member shared by all the objects of the class.

$9.4.2/6 - "Static data members of a class in namespace scope have external linkage (3.5).A local class shall not have static data members."

So let's say 'myclass.h' has

struct myclass{
   static int zzz;        // this is only a declaration
};

and myclass.cpp has

#include "myclass.h"

int myclass::zzz = 0           // this is a definition, 
                               // should be done once and only once

and "hisclass.cpp" has

#include "myclass.h"

void f(){myclass::zzz = 2;}    // myclass::zzz is always the same in any 
                               // translation unit

and "ourclass.cpp" has

#include "myclass.h"
void g(){myclass::zzz = 2;}    // myclass::zzz is always the same in any 
                               // translation unit

So, class static members are not limited to only 2 translation units. They need to be defined only once in any one of the translation units.

Note: usage of 'static' to declare file scope variable is deprecated and unnamed namespace is a superior alternate

Why do we need boxing and unboxing in C#?

In the .NET framework, there are two species of types--value types and reference types. This is relatively common in OO languages.

One of the important features of object oriented languages is the ability to handle instances in a type-agnostic manner. This is referred to as polymorphism. Since we want to take advantage of polymorphism, but we have two different species of types, there has to be some way to bring them together so we can handle one or the other the same way.

Now, back in the olden days (1.0 of Microsoft.NET), there weren't this newfangled generics hullabaloo. You couldn't write a method that had a single argument that could service a value type and a reference type. That's a violation of polymorphism. So boxing was adopted as a means to coerce a value type into an object.

If this wasn't possible, the framework would be littered with methods and classes whose only purpose was to accept the other species of type. Not only that, but since value types don't truly share a common type ancestor, you'd have to have a different method overload for each value type (bit, byte, int16, int32, etc etc etc).

Boxing prevented this from happening. And that's why the British celebrate Boxing Day.

Calling UserForm_Initialize() in a Module

SOLUTION After all this time, I managed to resolve the problem.

In Module: UserForms(Name).Userform_Initialize

This method works best to dynamically init the current UserForm

HTML table: keep the same width for columns

In your case, since you are only showing 3 columns:

Name    Value       Business
  or
Name    Business    Ecommerce Pro

why not set all 3 to have a width of 33.3%. since only 3 are ever shown at once, the browser should render them all a similar width.

R dplyr: Drop multiple columns

Check the help on select_vars. That gives you some extra ideas on how to work with this.

In your case:

iris %>% select(-one_of(drop.cols))

How do I save JSON to local text file

Here is a solution on pure js. You can do it with html5 saveAs. For example this lib could be helpful: https://github.com/eligrey/FileSaver.js
Look at the demo: http://eligrey.com/demos/FileSaver.js/
P.S. There is no information about json save, but you can do it changing file type to "application/json" and format to .json

Putty: Getting Server refused our key Error

Another reason could be UTF-8 BOM in the authorized_keys file.

How to check if a string in Python is in ASCII?

How about doing this?

import string

def isAscii(s):
    for c in s:
        if c not in string.ascii_letters:
            return False
    return True

String or binary data would be truncated. The statement has been terminated

When you define varchar etc without a length, the default is 1.

When n is not specified in a data definition or variable declaration statement, the default length is 1. When n is not specified with the CAST function, the default length is 30.

So, if you expect 400 bytes in the @trackingItems1 column from stock, use nvarchar(400).

Otherwise, you are trying to fit >1 character into nvarchar(1) = fail

As a comment, this is bad use of table value function too because it is "multi statement". It can be written like this and it will run better

ALTER FUNCTION [dbo].[testing1](@price int)
RETURNS
AS
   SELECT ta.item, ta.warehouse, ta.price 
   FROM   stock ta
   WHERE  ta.price >= @price;

Of course, you could just use a normal SELECT statement..

Best way to list files in Java, sorted by Date Modified?

I think your solution is the only sensible way. The only way to get the list of files is to use File.listFiles() and the documentation states that this makes no guarantees about the order of the files returned. Therefore you need to write a Comparator that uses File.lastModified() and pass this, along with the array of files, to Arrays.sort().

Pip Install not installing into correct directory?

You could just change the shebang line. I do this all the time on new systems.

If you want pip to install to a current version of Python installed just update the shebang line to the correct version of pythons path.

For example, to change pip (not pip3) to install to Python 3:

#!/usr/bin/python

To:

#!/usr/bin/python3

Any module you install using pip should install to Python not Python.

Or you could just change the path.

How to set shape's opacity?

Use this one, I've written this to my app,

<?xml version="1.0" encoding="utf-8"?>
<!--  res/drawable/rounded_edittext.xml -->
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" android:padding="10dp">
    <solid android:color="#882C383E"/>
    <corners
        android:bottomRightRadius="5dp"
        android:bottomLeftRadius="5dp"
        android:topLeftRadius="5dp"
        android:topRightRadius="5dp"/>
</shape>

How to redirect to Index from another controller?

Complete answer (.Net Core 3.1)

Most answers here are correct but taken a bit out of context, so I will provide a full-fledged answer which works for Asp.Net Core 3.1. For completeness' sake:

[Route("health")]
[ApiController]
public class HealthController : Controller
{
    [HttpGet("some_health_url")]
    public ActionResult SomeHealthMethod() {}
}

[Route("v2")]
[ApiController]
public class V2Controller : Controller
{
    [HttpGet("some_url")]
    public ActionResult SomeV2Method()
    {
        return RedirectToAction("SomeHealthMethod", "Health"); // omit "Controller"
    }
}

If you try to use any of the url-specific strings, e.g. "some_health_url", it will not work!

How to return a resultset / cursor from a Oracle PL/SQL anonymous block that executes Dynamic SQL?

in SQL*Plus you could also use a REFCURSOR variable:

SQL> VARIABLE x REFCURSOR
SQL> DECLARE
  2   V_Sqlstatement Varchar2(2000);
  3  BEGIN
  4   V_Sqlstatement := 'SELECT * FROM DUAL';
  5   OPEN :x for v_Sqlstatement;
  6  End;
  7  /

ProcÚdure PL/SQL terminÚe avec succÞs.

SQL> print x;

D
-
X

Formatting floats without trailing zeros

Handling %f and you should put

%.2f

, where: .2f == .00 floats.

Example:

print "Price: %.2f" % prices[product]

output:

Price: 1.50

JavaFX open new window

I use the following method in my JavaFX applications.

newWindowButton.setOnMouseClicked((event) -> {
    try {
        FXMLLoader fxmlLoader = new FXMLLoader();
        fxmlLoader.setLocation(getClass().getResource("NewWindow.fxml"));
        /* 
         * if "fx:controller" is not set in fxml
         * fxmlLoader.setController(NewWindowController);
         */
        Scene scene = new Scene(fxmlLoader.load(), 600, 400);
        Stage stage = new Stage();
        stage.setTitle("New Window");
        stage.setScene(scene);
        stage.show();
    } catch (IOException e) {
        Logger logger = Logger.getLogger(getClass().getName());
        logger.log(Level.SEVERE, "Failed to create new Window.", e);
    }
});

Passing arguments to an interactive program non-interactively

Many ways

pipe your input

echo "yes
no
maybe" | your_program

redirect from a file

your_program < answers.txt

use a here document (this can be very readable)

your_program << ANSWERS
yes
no
maybe
ANSWERS

use a here string

your_program <<< $'yes\nno\nmaybe\n'

Convert array to JSON

Wow, seems it got a lot easier nowadays... 3 ways you can do it:

json = { ...array };

json = Object.assign({}, array);

json = array.reduce((json, value, key) => { json[key] = value; return json; }, {});

How to set all elements of an array to zero or any same value?

You could use memset, if you sure about the length.

memset(ptr, 0x00, length)

How to uninstall Jenkins?

Keep in mind, that in Terminal you need to add backslash before space, so the proper copy/paste will be

/Library/Application\ Support/Jenkins/Uninstall.command

p.s. sorry for the late answer :)

Storing Objects in HTML5 localStorage

You cannot store key value without String Format.

LocalStorage only support String format for key/value.

That is why you should convert your data to string whatever it is Array or Object.

To Store data in localStorage first of all stringify it using JSON.stringify() method.

var myObj = [{name:"test", time:"Date 2017-02-03T08:38:04.449Z"}];
localStorage.setItem('item', JSON.stringify(myObj));

Then when you want to retrieve data , you need to parse the String to Object again.

var getObj = JSON.parse(localStorage.getItem('item'));

Hope it helps.

Skip over a value in the range function in python

It depends on what you want to do. For example you could stick in some conditionals like this in your comprehensions:

# get the squares of each number from 1 to 9, excluding 2
myList = [i**2 for i in range(10) if i != 2]
print(myList)

# --> [0, 1, 9, 16, 25, 36, 49, 64, 81]

How to set HttpResponse timeout for Android in Java

An option is to use the OkHttp client, from Square.

Add the library dependency

In the build.gradle, include this line:

compile 'com.squareup.okhttp:okhttp:x.x.x'

Where x.x.x is the desired library version.

Set the client

For example, if you want to set a timeout of 60 seconds, do this way:

final OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setReadTimeout(60, TimeUnit.SECONDS);
okHttpClient.setConnectTimeout(60, TimeUnit.SECONDS);

ps: If your minSdkVersion is greater than 8, you can use TimeUnit.MINUTES. So, you can simply use:

okHttpClient.setReadTimeout(1, TimeUnit.MINUTES);
okHttpClient.setConnectTimeout(1, TimeUnit.MINUTES);

For more details about the units, see TimeUnit.

List of all users that can connect via SSH

Any user with a valid shell in /etc/passwd can potentially login. If you want to improve security, set up SSH with public-key authentication (there is lots of info on the web on doing this), install a public key in one user's ~/.ssh/authorized_keys file, and disable password-based authentication. This will prevent anybody except that one user from logging in, and will require that the user have in their possession the matching private key. Make sure the private key has a decent passphrase.

To prevent bots from trying to get in, run SSH on a port other than 22 (i.e. 3456). This doesn't improve security but prevents script-kiddies and bots from cluttering up your logs with failed attempts.

Difference between "enqueue" and "dequeue"

Enqueue and Dequeue tend to be operations on a queue, a data structure that does exactly what it sounds like it does.

You enqueue items at one end and dequeue at the other, just like a line of people queuing up for tickets to the latest Taylor Swift concert (I was originally going to say Billy Joel but that would date me severely).

There are variations of queues such as double-ended ones where you can enqueue and dequeue at either end but the vast majority would be the simpler form:

           +---+---+---+
enqueue -> | 3 | 2 | 1 | -> dequeue
           +---+---+---+

That diagram shows a queue where you've enqueued the numbers 1, 2 and 3 in that order, without yet dequeuing any.


By way of example, here's some Python code that shows a simplistic queue in action, with enqueue and dequeue functions. Were it more serious code, it would be implemented as a class but it should be enough to illustrate the workings:

import random

def enqueue(lst, itm):
    lst.append(itm)        # Just add item to end of list.
    return lst             # And return list (for consistency with dequeue).

def dequeue(lst):
    itm = lst[0]           # Grab the first item in list.
    lst = lst[1:]          # Change list to remove first item.
    return (itm, lst)      # Then return item and new list.

# Test harness. Start with empty queue.

myList = []

# Enqueue or dequeue a bit, with latter having probability of 10%.

for _ in range(15):
    if random.randint(0, 9) == 0 and len(myList) > 0:
        (itm, myList) = dequeue(myList)
        print(f"Dequeued {itm} to give {myList}")
    else:
        itm = 10 * random.randint(1, 9)
        myList = enqueue(myList, itm)
        print(f"Enqueued {itm} to give {myList}")

# Now dequeue remainder of list.

print("========")
while len(myList) > 0:
    (itm, myList) = dequeue(myList)
    print(f"Dequeued {itm} to give {myList}")

A sample run of that shows it in operation:

Enqueued 70 to give [70]
Enqueued 20 to give [70, 20]
Enqueued 40 to give [70, 20, 40]
Enqueued 50 to give [70, 20, 40, 50]
Dequeued 70 to give [20, 40, 50]
Enqueued 20 to give [20, 40, 50, 20]
Enqueued 30 to give [20, 40, 50, 20, 30]
Enqueued 20 to give [20, 40, 50, 20, 30, 20]
Enqueued 70 to give [20, 40, 50, 20, 30, 20, 70]
Enqueued 20 to give [20, 40, 50, 20, 30, 20, 70, 20]
Enqueued 20 to give [20, 40, 50, 20, 30, 20, 70, 20, 20]
Dequeued 20 to give [40, 50, 20, 30, 20, 70, 20, 20]
Enqueued 80 to give [40, 50, 20, 30, 20, 70, 20, 20, 80]
Dequeued 40 to give [50, 20, 30, 20, 70, 20, 20, 80]
Enqueued 90 to give [50, 20, 30, 20, 70, 20, 20, 80, 90]
========
Dequeued 50 to give [20, 30, 20, 70, 20, 20, 80, 90]
Dequeued 20 to give [30, 20, 70, 20, 20, 80, 90]
Dequeued 30 to give [20, 70, 20, 20, 80, 90]
Dequeued 20 to give [70, 20, 20, 80, 90]
Dequeued 70 to give [20, 20, 80, 90]
Dequeued 20 to give [20, 80, 90]
Dequeued 20 to give [80, 90]
Dequeued 80 to give [90]
Dequeued 90 to give []

XML Carriage return encoding

To insert a CR into XML, you need to use its character entity &#13;.

This is because compliant XML parsers must, before parsing, translate CRLF and any CR not followed by a LF to a single LF. This behavior is defined in the End-of-Line handling section of the XML 1.0 specification.

Android: Scale a Drawable or background image?

One option to try is to put the image in the drawable-nodpi folder and set background of a layout to the drawable resource id.

This definitely works with scaling down, I haven't tested with scaling up though.

Comment shortcut Android Studio

In Android studio CTRL + SHIFT + / for windows.

How can I output the value of an enum class in C++11

(I'm not allowed to comment yet.) I would suggest the following improvements to the already great answer of James McNellis:

template <typename Enumeration>
constexpr auto as_integer(Enumeration const value)
    -> typename std::underlying_type<Enumeration>::type
{
    static_assert(std::is_enum<Enumeration>::value, "parameter is not of type enum or enum class");
    return static_cast<typename std::underlying_type<Enumeration>::type>(value);
}

with

  • constexpr: allowing me to use an enum member value as compile-time array size
  • static_assert+is_enum: to 'ensure' compile-time that the function does sth. with enumerations only, as suggested

By the way I'm asking myself: Why should I ever use enum class when I would like to assign number values to my enum members?! Considering the conversion effort.

Perhaps I would then go back to ordinary enum as I suggested here: How to use enums as flags in C++?


Yet another (better) flavor of it without static_assert, based on a suggestion of @TobySpeight:

template <typename Enumeration>
constexpr std::enable_if_t<std::is_enum<Enumeration>::value,
std::underlying_type_t<Enumeration>> as_number(const Enumeration value)
{
    return static_cast<std::underlying_type_t<Enumeration>>(value);
}

How to use pull to refresh in Swift?

I suggest to make an Extension of pull To Refresh to use in every class.

1) Make an empty swift file : File - New - File - Swift File.

2) Add the Following

    //  AppExtensions.swift

    import Foundation
    import UIKit    

    var tableRefreshControl:UIRefreshControl = UIRefreshControl()    

    //MARK:- VIEWCONTROLLER EXTENSION METHODS
    public extension UIViewController
    {
        func makePullToRefreshToTableView(tableName: UITableView,triggerToMethodName: String){

            tableRefreshControl.attributedTitle = NSAttributedString(string: "TEST: Pull to refresh")
            tableRefreshControl.backgroundColor = UIColor.whiteColor()
            tableRefreshControl.addTarget(self, action: Selector(triggerToMethodName), forControlEvents: UIControlEvents.ValueChanged)
            tableName.addSubview(tableRefreshControl)
        }
        func makePullToRefreshEndRefreshing (tableName: String)
        {
            tableRefreshControl.endRefreshing()
//additional codes

        }
    }    

3) In Your View Controller call these methods as :

  override func viewWillAppear(animated: Bool) {

self.makePullToRefreshToTableView(bidderListTable, triggerToMethodName: "pullToRefreshBidderTable")
}

4) At some point you wanted to end refreshing:

  func pullToRefreshBidderTable() {
self.makePullToRefreshEndRefreshing("bidderListTable")    
//Code What to do here.
}
OR    
self.makePullToRefreshEndRefreshing("bidderListTable")

Python string.join(list) on object array rather than string array

The built-in string constructor will automatically call obj.__str__:

''.join(map(str,list))

jQuery Combobox/select autocomplete?

Have a look at the following example of the jQueryUI Autocomplete, as it is keeping a select around and I think that is what you are looking for. Hope this helps.

http://jqueryui.com/demos/autocomplete/#combobox

Unit test naming best practices

I like Roy Osherove's naming strategy. It's the following:

[UnitOfWork_StateUnderTest_ExpectedBehavior]

It has every information needed on the method name and in a structured manner.

The unit of work can be as small as a single method, a class, or as large as multiple classes. It should represent all the things that are to be tested in this test case and are under control.

For assemblies, I use the typical .Tests ending, which I think is quite widespread and the same for classes (ending with Tests):

[NameOfTheClassUnderTestTests]

Previously, I used Fixture as suffix instead of Tests, but I think the latter is more common, then I changed the naming strategy.

How to swap String characters in Java?

import java.io.*;
class swaping
{
     public static void main(String args[]) 
     {
         String name="premkumarg";
         int len=name.length();
         char[] c = name.toCharArray();
         for(int i=0;i<len-1;i=i+2)
         {
             char temp= c[i];
             c[i]=c[i+1];
             c[i+1]=temp;
         }

         System.out.println("Swapping string is: ");
         System.out.println(c);

    }
}

REST API - why use PUT DELETE POST GET?

You asked:

wouldn't it be easier to just accept JSON object through normal $_POST and then respond in JSON as well

From the Wikipedia on REST:

RESTful applications maximize the use of the pre-existing, well-defined interface and other built-in capabilities provided by the chosen network protocol, and minimize the addition of new application-specific features on top of it

From what (little) I've seen, I believe this is usually accomplished by maximizing the use of existing HTTP verbs, and designing a URL scheme for your service that is as powerful and self-evident as possible.

Custom data protocols (even if they are built on top of standard ones, such as SOAP or JSON) are discouraged, and should be minimized to best conform to the REST ideology.

SOAP RPC over HTTP, on the other hand, encourages each application designer to define a new and arbitrary vocabulary of nouns and verbs (for example getUsers(), savePurchaseOrder(...)), usually overlaid onto the HTTP 'POST' verb. This disregards many of HTTP's existing capabilities such as authentication, caching and content type negotiation, and may leave the application designer re-inventing many of these features within the new vocabulary.

The actual objects you are working with can be in any format. The idea is to reuse as much of HTTP as possible to expose your operations the user wants to perform on those resource (queries, state management/mutation, deletion).

You asked:

Am I missing something?

There is a lot more to know about REST and the URI syntax/HTTP verbs themselves. For example, some of the verbs are idempotent, others aren't. I didn't see anything about this in your question, so I didn't bother trying to dive into it. The other answers and Wikipedia both have a lot of good information.

Also, there is a lot to learn about the various network technologies built on top of HTTP that you can take advantage of if you're using a truly restful API. I'd start with authentication.

Find size of an array in Perl

First, the second is not equivalent to the other two. $#array returns the last index of the array, which is one less than the size of the array.

The other two are virtually the same. You are simply using two different means to create scalar context. It comes down to a question of readability.

I personally prefer the following:

say 0+@array;          # Represent @array as a number

I find it clearer than

say scalar(@array);    # Represent @array as a scalar

and

my $size = @array;
say $size;

The latter looks quite clear alone like this, but I find that the extra line takes away from clarity when part of other code. It's useful for teaching what @array does in scalar context, and maybe if you want to use $size more than once.

How to obtain the last index of a list?

len(list1)-1 is definitely the way to go, but if you absolutely need a list that has a function that returns the last index, you could create a class that inherits from list.

class MyList(list):
    def last_index(self):
        return len(self)-1


>>> l=MyList([1, 2, 33, 51])
>>> l.last_index()
3

What is the correct way to free memory in C#

The .NET garbage collector takes care of all this for you.

It is able to determine when objects are no longer referenced and will (eventually) free the memory that had been allocated to them.

How to sort with lambda in Python

Use

a = sorted(a, key=lambda x: x.modified, reverse=True)
#             ^^^^

On Python 2.x, the sorted function takes its arguments in this order:

sorted(iterable, cmp=None, key=None, reverse=False)

so without the key=, the function you pass in will be considered a cmp function which takes 2 arguments.

Is it possible to create a 'link to a folder' in a SharePoint document library?

The simplest way is to use the following pattern:

http://[server]/[site]/[ListName]/[Folder]/[SubFolder]

To place a shortcut to a document library:

  1. Upload it as *.url file. However, by default, this file type is not allowed.
  2. Go to you Document Library settings > Advanced Settings > Allow management of content types. Add the "Link to document" content type to a document library and paste the link

How to save all files from source code of a web site?

In Chrome, go to options (Customize and Control, the 3 dots/bars at top right) ---> More Tools ---> save page as

save page as  
filename     : any_name.html 
save as type : webpage complete.

Then you will get any_name.html and any_name folder.

Timestamp to human readable format

var newDate = new Date();
newDate.setTime(unixtime*1000);
dateString = newDate.toUTCString();

Where unixtime is the time returned by your sql db. Here is a fiddle if it helps.

For example, using it for the current time:

_x000D_
_x000D_
document.write( new Date().toUTCString() );
_x000D_
_x000D_
_x000D_

Php - testing if a radio button is selected and get the value

I suggest you do it through the GET request: for example, index.html:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<form action="result.php" method="post">
  Answer 1 <input type="radio" name="ans" value="ans1" /><br />
  Answer 2 <input type="radio" name="ans" value="ans2"  /><br />
  Answer 3 <input type="radio" name="ans" value="ans3"  /><br />
  Answer 4 <input type="radio" name="ans" value="ans4"  /><br />
  <input type="button" value="submit" onclick="sendPost()" />
 </form>
 <script type="text/javascript">
    function sendPost(){
        var value = $('input[name="ans"]:checked').val();
        window.location.href = "sendpost.php?ans="+value;
    };
 </script>

this is sendpost.php:

<?php
if(isset($_GET["ans"]) AND !empty($_GET["ans"])){
    echo $_GET["ans"];
}
?>

PDF Parsing Using Python - extracting formatted and plain texts

That's a difficult problem to solve since visually similar PDFs may have a wildly differing structure depending on how they were produced. In the worst case the library would need to basically act like an OCR. On the other hand, the PDF may contain sufficient structure and metadata for easy removal of tables and figures, which the library can be tailored to take advantage of.

I'm pretty sure there are no open source tools which solve your problem for a wide variety of PDFs, but I remember having heard of commercial software claiming to do exactly what you ask for. I'm sure you'll run into them while googling.

Python Requests package: Handling xml response

requests does not handle parsing XML responses, no. XML responses are much more complex in nature than JSON responses, how you'd serialize XML data into Python structures is not nearly as straightforward.

Python comes with built-in XML parsers. I recommend you use the ElementTree API:

import requests
from xml.etree import ElementTree

response = requests.get(url)

tree = ElementTree.fromstring(response.content)

or, if the response is particularly large, use an incremental approach:

    response = requests.get(url, stream=True)
    # if the server sent a Gzip or Deflate compressed response, decompress
    # as we read the raw stream:
    response.raw.decode_content = True

    events = ElementTree.iterparse(response.raw)
    for event, elem in events:
        # do something with `elem`

The external lxml project builds on the same API to give you more features and power still.

window.onunload is not working properly in Chrome browser. Can any one help me?

There are some actions which are not working in chrome, inside of the unload event. Alert or confirm boxes are such things.

But what is possible (AFAIK):

  1. Open popups (with window.open) - but this will just work, if the popup blocker is disabled for your site
  2. Return a simple string (in beforeunload event), which triggers a confirm box, which asks the user if s/he want to leave the page.

Example for #2:

$(window).on('beforeunload', function() {
    return 'Your own message goes here...';
});

Demo: http://jsfiddle.net/PQz5k/

What is the difference between dict.items() and dict.iteritems() in Python2?

You asked: 'Are there any applicable differences between dict.items() and dict.iteritems()'

This may help (for Python 2.x):

>>> d={1:'one',2:'two',3:'three'}
>>> type(d.items())
<type 'list'>
>>> type(d.iteritems())
<type 'dictionary-itemiterator'>

You can see that d.items() returns a list of tuples of the key, value pairs and d.iteritems() returns a dictionary-itemiterator.

As a list, d.items() is slice-able:

>>> l1=d.items()[0]
>>> l1
(1, 'one')   # an unordered value!

But would not have an __iter__ method:

>>> next(d.items())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list object is not an iterator

As an iterator, d.iteritems() is not slice-able:

>>> i1=d.iteritems()[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'dictionary-itemiterator' object is not subscriptable

But does have __iter__:

>>> next(d.iteritems())
(1, 'one')               # an unordered value!

So the items themselves are same -- the container delivering the items are different. One is a list, the other an iterator (depending on the Python version...)

So the applicable differences between dict.items() and dict.iteritems() are the same as the applicable differences between a list and an iterator.

Cropping an UIImage

To crop retina images while keeping the same scale and orientation, use the following method in a UIImage category (iOS 4.0 and above):

- (UIImage *)crop:(CGRect)rect {
    if (self.scale > 1.0f) {
        rect = CGRectMake(rect.origin.x * self.scale,
                          rect.origin.y * self.scale,
                          rect.size.width * self.scale,
                          rect.size.height * self.scale);
    }

    CGImageRef imageRef = CGImageCreateWithImageInRect(self.CGImage, rect);
    UIImage *result = [UIImage imageWithCGImage:imageRef scale:self.scale orientation:self.imageOrientation];
    CGImageRelease(imageRef);
    return result;
}

Python: Writing to and Reading from serial port

a piece of code who work with python to read rs232 just in case somedoby else need it

ser = serial.Serial('/dev/tty.usbserial', 9600, timeout=0.5)
ser.write('*99C\r\n')
time.sleep(0.1)
ser.close()

Redirecting to authentication dialog - "An error occurred. Please try again later"

I had the same problem and the root cause was different:

I was logged in as a Test User of a different application. Therefore I wasn't able to authorize an app that's not the one where the Test User was created for.

When I logged out and logged in as a regular user or a Test User for the app I tried to authorize, everything was OK.

Check if a file exists in jenkins pipeline

You need to use brackets when using the fileExists step in an if condition or assign the returned value to a variable

Using variable:

def exists = fileExists 'file'

if (exists) {
    echo 'Yes'
} else {
    echo 'No'
}

Using brackets:

if (fileExists('file')) {
    echo 'Yes'
} else {
    echo 'No'
}

C++ convert string to hexadecimal and vice versa

As of C++17 there's also std::from_chars. The following function takes a string of hex characters and returns a vector of T:

#include <charconv>

template<typename T>
std::vector<T> hexstr_to_vec(const std::string& str, unsigned char chars_per_num = 2)
{
  std::vector<T> out(str.size() / chars_per_num, 0);

  T value;
  for (int i = 0; i < str.size() / chars_per_num; i++) {
    std::from_chars<T>(
      str.data() + (i * chars_per_num),
      str.data() + (i * chars_per_num) + chars_per_num,
      value,
      16
    );
    out[i] = value;
  }

  return out;
}

crudrepository findBy method signature with multiple in operators?

The following signature will do:

List<Email> findByEmailIdInAndPincodeIn(List<String> emails, List<String> pinCodes);

Spring Data JPA supports a large number of keywords to build a query. IN and AND are among them.

What should I use to open a url instead of urlopen in urllib3

You do not have to install urllib3. You can choose any HTTP-request-making library that fits your needs and feed the response to BeautifulSoup. The choice is though usually requests because of the rich feature set and convenient API. You can install requests by entering pip install requests in the command line. Here is a basic example:

from bs4 import BeautifulSoup
import requests

url = "url"
response = requests.get(url)

soup = BeautifulSoup(response.content, "html.parser")

Separating class code into a header and cpp file

I won't refer too your example as it is quite simple for a general answer (for example it doesn't contain templated functions ,which force you to implement them on the header) , what I follow as a rule of thumb is the pimpl idiom

It has quite some benefits as you get faster compilation times and the syntactic sugar :

class->member instead of class.member

The only drawback is the extra pointer you pay.

Executing <script> injected by innerHTML after AJAX call

I had a similiar post here, addEventListener load on ajax load WITHOUT jquery

How I solved it was to insert calls to functions within my stateChange function. The page I had setup was 3 buttons that would load 3 different pages into the contentArea. Because I had to know which button was being pressed to load page 1, 2 or 3, I could easily use if/else statements to determine which page is being loaded and then which function to run. What I was trying to do was register different button listeners that would only work when the specific page was loaded because of element IDs..

so...

if (page1 is being loaded, pageload = 1) run function registerListeners1

then the same for page 2 or 3.

Increasing Google Chrome's max-connections-per-server limit to more than 6

IE is even worse with 2 connection per domain limit. But I wouldn't rely on fixing client browsers. Even if you have control over them, browsers like chrome will auto update and a future release might behave differently than you expect. I'd focus on solving the problem within your system design.

Your choices are to:

  1. Load the images in sequence so that only 1 or 2 XHR calls are active at a time (use the success event from the previous image to check if there are more images to download and start the next request).

  2. Use sub-domains like serverA.myphotoserver.com and serverB.myphotoserver.com. Each sub domain will have its own pool for connection limits. This means you could have 2 requests going to 5 different sub-domains if you wanted to. The downfall is that the photos will be cached according to these sub-domains. BTW, these don't need to be "mirror" domains, you can just make additional DNS pointers to the exact same website/server. This means you don't have the headache of administrating many servers, just one server with many DNS records.

How can I set the default timezone in node.js?

The solution env TZ='Europe/Amsterdam' node server.js from @uhef works in cases where your app doesn't work with forked process, but when you are working with forked process, specially when you launch your app with a building tool like gulp , the command gulp will take the env values, but the process created by gulp not (your app).

To solve this, you have to do:

$ export TZ="Europe/Amsterdam"; gulp myTask

This will set the TZ environment variable for all the process started in the console you are working on, included all the subsequents process executed after the gulp command in the same console without the need to execute them with the prefix export TZ="Europe/Amsterdam"; again.

How can I listen for keypress event on the whole page?

I think this does the best job

https://angular.io/api/platform-browser/EventManager

for instance in app.component

constructor(private eventManager: EventManager) {
    const removeGlobalEventListener = this.eventManager.addGlobalEventListener(
      'document',
      'keypress',
      (ev) => {
        console.log('ev', ev);
      }
    );
  }

Adding 1 hour to time variable

$time = '10:09';
$timestamp = strtotime($time);
$timestamp_one_hour_later = $timestamp + 3600; // 3600 sec. = 1 hour

// Formats the timestamp to HH:MM => outputs 11:09.
echo strftime('%H:%M', $timestamp_one_hour_later);
// As crolpa suggested, you can also do
// echo date('H:i', $timestamp_one_hour_later);

Check PHP manual for strtotime(), strftime() and date() for details.

BTW, in your initial code, you need to add some quotes otherwise you will get PHP syntax errors:

$time = 10:09; // wrong syntax
$time = '10:09'; // syntax OK

$time = date(H:i, strtotime('+1 hour')); // wrong syntax
$time = date('H:i', strtotime('+1 hour')); // syntax OK

Removing duplicate characters from a string

If order does matter, how about:

>>> foo = 'mppmt'
>>> ''.join(sorted(set(foo), key=foo.index))
'mpt'

How do I do a multi-line string in node.js?

Take a look at CoffeeScript: http://coffeescript.org

It supports multi-line strings, interpolation, array comprehensions and lots of other nice stuff.

MySQL - Replace Character in Columns

maybe I'd go by this.

 SQL = SELECT REPLACE(myColumn, '""', '\'') FROM myTable

I used singlequotes because that's the one that registers string expressions in MySQL, or so I believe.

Hope that helps.

Selenium wait until document is ready

public void waitForPageToLoad()
  {
(new WebDriverWait(driver, DEFAULT_WAIT_TIME)).until(new ExpectedCondition<Boolean>() {
      public Boolean apply(WebDriver d) {
        return (((org.openqa.selenium.JavascriptExecutor) driver).executeScript("return document.readyState").equals("complete"));
      }
    });//Here DEFAULT_WAIT_TIME is a integer correspond to wait time in seconds

Submit HTML form on self page

You can do it using the same page on the action attribute: action='<yourpage>'

Checking letter case (Upper/Lower) within a string in Java

function TellFirstCharacterType(inputString){
    var firstCharacter = inputString[0];
    if(isNaN(firstCharacter)){
        if(firstCharacter == firstCharacter.toUpperCase()){
            return "It's a uppercase character";
        }
        else{
            return "It's a lowercase character";
        }
    }
    else{
        return "It's a Number";
    }
}

How to insert close button in popover for Bootstrap

Previous examples have two main drawbacks:

  1. The 'close' button needs in some way, to be aware of the ID of the referenced-element.
  2. The need of adding on the 'shown.bs.popover' event, a 'click' listener to the close button; which is also not a good solution because of, you would then be adding such listener each time the 'popover' is shown.

Below is a solution which has not such drawbacks.

By the default, the 'popover' element is inserted immediately after the referenced-element in the DOM (then notice the referenced-element and the popover are immediate sibling elements). Thus, when the 'close' button is clicked, you can simply look for its closest 'div.popover' parent, and then look for the immediately preceding sibling element of such parent.

Just add the following code in the 'onclick' handler of the 'close button:

$(this).closest('div.popover').popover('hide');

Example:

var genericCloseBtnHtml = '<button onclick="$(this).closest(\'div.popover\').popover(\'hide\');" type="button" class="close" aria-hidden="true">&times;</button>';

$loginForm.popover({
    placement: 'auto left',
    trigger: 'manual',
    html: true,
    title: 'Alert' + genericCloseBtnHtml,
    content: 'invalid email and/or password'
});

How to convert NSDate into unix timestamp iphone sdk?

Swift

Updated for Swift 3

// current date and time
let someDate = Date()

// time interval since 1970
let myTimeStamp = someDate.timeIntervalSince1970

Notes

  • timeIntervalSince1970 returns TimeInterval, which is a typealias for Double.

  • If you wanted to go the other way you could do the following:

      let myDate = Date(timeIntervalSince1970: myTimeStamp)
    

Getting date format m-d-Y H:i:s.u from milliseconds

Based on @ArchCodeMonkey answer.

If you have declare(strict_types=1) you must cast second argument to string

enter image description here

How to use doxygen to create UML class diagrams from C++ source

Quote from this post (it's written by the author of doxygen himself) :

run doxygen -g and change the following options of the generated Doxyfile:

    EXTRACT_ALL            = YES
    HAVE_DOT               = YES
    UML_LOOK               = YES

run doxygen again

Error when using scp command "bash: scp: command not found"

Check if scp is installed or not on from where you want want to copy check using which scp

If it's already installed, it will print you a path like /usr/bin/scp Else, install scp using:

yum -y install openssh-clients

Then copy command

scp -r [email protected]:/var/www/html/database_backup/restore_fullbackup/backup_20140308-023002.sql  /var/www/html/db_bkp/

Working Copy Locked

error "working copy locked", Just follow the steps :

  1. In which directory you are getting error on update
  2. Go to its parent directory
  3. In parent directory go to ".svn" hidden directory
  4. Remove file with name "lock"
  5. Clean up and Done

You can update the svn properly without error

Callback when CSS3 transition finishes

For transitions you can use the following to detect the end of a transition via jQuery:

$("#someSelector").bind("transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd", function(){ ... });

Mozilla has an excellent reference:

https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Transitions/Using_CSS_transitions#Detecting_the_start_and_completion_of_a_transition

For animations it's very similar:

$("#someSelector").bind("animationend webkitAnimationEnd oAnimationEnd MSAnimationEnd", function(){ ... });

Note that you can pass all of the browser prefixed event strings into the bind() method simultaneously to support the event firing on all browsers that support it.

Update:

Per the comment left by Duck: you use jQuery's .one() method to ensure the handler only fires once. For example:

$("#someSelector").one("transitionend webkitTransitionEnd oTransitionEnd MSTransitionEnd", function(){ ... });

$("#someSelector").one("animationend webkitAnimationEnd oAnimationEnd MSAnimationEnd", function(){ ... });

Update 2:

jQuery bind() method has been deprecated, and on() method is preferred as of jQuery 1.7. bind()

You can also use off() method on the callback function to ensure it will be fired only once. Here is an example which is equivalent to using one() method:

$("#someSelector")
.on("animationend webkitAnimationEnd oAnimationEnd MSAnimationEnd",
 function(e){
    // do something here
    $(this).off(e);
 });

References:

How to debug Apache mod_rewrite

The LogRewrite directive as mentioned by Ben is not available anymore in Apache 2.4. You need to use the LogLevel directive instead. E.g.

LogLevel alert rewrite:trace6

See http://httpd.apache.org/docs/2.4/mod/mod_rewrite.html#logging

Find a line in a file and remove it

You want to do something like the following:

  • Open the old file for reading
  • Open a new (temporary) file for writing
  • Iterate over the lines in the old file (probably using a BufferedReader)
    • For each line, check if it matches what you are supposed to remove
    • If it matches, do nothing
    • If it doesn't match, write it to the temporary file
  • When done, close both files
  • Delete the old file
  • Rename the temporary file to the name of the original file

(I won't write the actual code, since this looks like homework, but feel free to post other questions on specific bits that you have trouble with)