Programs & Examples On #Cumulative frequency

Mapping two integers to one, in a unique and deterministic way

Cantor pairing function is really one of the better ones out there considering its simple, fast and space efficient, but there is something even better published at Wolfram by Matthew Szudzik, here. The limitation of Cantor pairing function (relatively) is that the range of encoded results doesn't always stay within the limits of a 2N bit integer if the inputs are two N bit integers. That is, if my inputs are two 16 bit integers ranging from 0 to 2^16 -1, then there are 2^16 * (2^16 -1) combinations of inputs possible, so by the obvious Pigeonhole Principle, we need an output of size at least 2^16 * (2^16 -1), which is equal to 2^32 - 2^16, or in other words, a map of 32 bit numbers should be feasible ideally. This may not be of little practical importance in programming world.

Cantor pairing function:

(a + b) * (a + b + 1) / 2 + a; where a, b >= 0

The mapping for two maximum most 16 bit integers (65535, 65535) will be 8589803520 which as you see cannot be fit into 32 bits.

Enter Szudzik's function:

a >= b ? a * a + a + b : a + b * b;  where a, b >= 0

The mapping for (65535, 65535) will now be 4294967295 which as you see is a 32 bit (0 to 2^32 -1) integer. This is where this solution is ideal, it simply utilizes every single point in that space, so nothing can get more space efficient.


Now considering the fact that we typically deal with the signed implementations of numbers of various sizes in languages/frameworks, let's consider signed 16 bit integers ranging from -(2^15) to 2^15 -1 (later we'll see how to extend even the ouput to span over signed range). Since a and b have to be positive they range from 0 to 2^15 - 1.

Cantor pairing function:

The mapping for two maximum most 16 bit signed integers (32767, 32767) will be 2147418112 which is just short of maximum value for signed 32 bit integer.

Now Szudzik's function:

(32767, 32767) => 1073741823, much smaller..

Let's account for negative integers. That's beyond the original question I know, but just elaborating to help future visitors.

Cantor pairing function:

A = a >= 0 ? 2 * a : -2 * a - 1;
B = b >= 0 ? 2 * b : -2 * b - 1;
(A + B) * (A + B + 1) / 2 + A;

(-32768, -32768) => 8589803520 which is Int64. 64 bit output for 16 bit inputs may be so unpardonable!!

Szudzik's function:

A = a >= 0 ? 2 * a : -2 * a - 1;
B = b >= 0 ? 2 * b : -2 * b - 1;
A >= B ? A * A + A + B : A + B * B;

(-32768, -32768) => 4294967295 which is 32 bit for unsigned range or 64 bit for signed range, but still better.

Now all this while the output has always been positive. In signed world, it will be even more space saving if we could transfer half the output to negative axis. You could do it like this for Szudzik's:

A = a >= 0 ? 2 * a : -2 * a - 1;
B = b >= 0 ? 2 * b : -2 * b - 1;
C = (A >= B ? A * A + A + B : A + B * B) / 2;
a < 0 && b < 0 || a >= 0 && b >= 0 ? C : -C - 1;

(-32768, 32767) => -2147483648

(32767, -32768) => -2147450880

(0, 0) => 0 

(32767, 32767) => 2147418112

(-32768, -32768) => 2147483647

What I do: After applying a weight of 2 to the the inputs and going through the function, I then divide the ouput by two and take some of them to negative axis by multiplying by -1.

See the results, for any input in the range of a signed 16 bit number, the output lies within the limits of a signed 32 bit integer which is cool. I'm not sure how to go about the same way for Cantor pairing function but didn't try as much as its not as efficient. Furthermore, more calculations involved in Cantor pairing function means its slower too.

Here is a C# implementation.

public static long PerfectlyHashThem(int a, int b)
{
    var A = (ulong)(a >= 0 ? 2 * (long)a : -2 * (long)a - 1);
    var B = (ulong)(b >= 0 ? 2 * (long)b : -2 * (long)b - 1);
    var C = (long)((A >= B ? A * A + A + B : A + B * B) / 2);
    return a < 0 && b < 0 || a >= 0 && b >= 0 ? C : -C - 1;
}

public static int PerfectlyHashThem(short a, short b)
{
    var A = (uint)(a >= 0 ? 2 * a : -2 * a - 1);
    var B = (uint)(b >= 0 ? 2 * b : -2 * b - 1);
    var C = (int)((A >= B ? A * A + A + B : A + B * B) / 2);
    return a < 0 && b < 0 || a >= 0 && b >= 0 ? C : -C - 1;
}

Since the intermediate calculations can exceed limits of 2N signed integer, I have used 4N integer type (the last division by 2 brings back the result to 2N).

The link I have provided on alternate solution nicely depicts a graph of the function utilizing every single point in space. Its amazing to see that you could uniquely encode a pair of coordinates to a single number reversibly! Magic world of numbers!!

Is mongodb running?

Probably because I didn't shut down my dev server properly or a similar reason. To fix it, remove the lock and start the server with: sudo rm /var/lib/mongodb/mongod.lock ; sudo start mongodb

Python urllib2 Basic Auth Problem

(copy-paste/adapted from https://stackoverflow.com/a/24048772/1733117).

First you can subclass urllib2.BaseHandler or urllib2.HTTPBasicAuthHandler, and implement http_request so that each request has the appropriate Authorization header.

import urllib2
import base64

class PreemptiveBasicAuthHandler(urllib2.HTTPBasicAuthHandler):
    '''Preemptive basic auth.

    Instead of waiting for a 403 to then retry with the credentials,
    send the credentials if the url is handled by the password manager.
    Note: please use realm=None when calling add_password.'''
    def http_request(self, req):
        url = req.get_full_url()
        realm = None
        # this is very similar to the code from retry_http_basic_auth()
        # but returns a request object.
        user, pw = self.passwd.find_user_password(realm, url)
        if pw:
            raw = "%s:%s" % (user, pw)
            auth = 'Basic %s' % base64.b64encode(raw).strip()
            req.add_unredirected_header(self.auth_header, auth)
        return req

    https_request = http_request

Then if you are lazy like me, install the handler globally

api_url = "http://api.foursquare.com/"
api_username = "johndoe"
api_password = "some-cryptic-value"

auth_handler = PreemptiveBasicAuthHandler()
auth_handler.add_password(
    realm=None, # default realm.
    uri=api_url,
    user=api_username,
    passwd=api_password)
opener = urllib2.build_opener(auth_handler)
urllib2.install_opener(opener)

Utility of HTTP header "Content-Type: application/force-download" for mobile?

Content-Type: application/force-download means "I, the web server, am going to lie to you (the browser) about what this file is so that you will not treat it as a PDF/Word Document/MP3/whatever and prompt the user to save the mysterious file to disk instead". It is a dirty hack that breaks horribly when the client doesn't do "save to disk".

Use the correct mime type for whatever media you are using (e.g. audio/mpeg for mp3).

Use the Content-Disposition: attachment; etc etc header if you want to encourage the client to download it instead of following the default behaviour.

How to convert password into md5 in jquery?

jQuery doesnt have a method to provide the md5 of a string. So you need to use some external script. There is a plugin called jQuery MD5. and it gives you number of methods to achieve md5. Few of those are

Create (hex-encoded) MD5 hash of a given string value:

var md5 = $.md5('value');

Create (hex-encoded) HMAC-MD5 hash of a given string value and key:

var md5 = $.md5('value', 'key');

Create raw MD5 hash of a given string value:

var md5 = $.md5('value', null, true);

Create raw HMAC-MD5 hash of a given string value and key:

var md5 = $.md5('value', 'key', true);

This might do what you want... Check the snippet here. jQuery MD5

How can I list the scheduled jobs running in my database?

The DBA views are restricted. So you won't be able to query them unless you're connected as a DBA or similarly privileged user.

The ALL views show you the information you're allowed to see. Normally that would be jobs you've submitted, unless you have additional privileges.

The privileges you need are defined in the Admin Guide. Find out more.

So, either you need a DBA account or you need to chat with your DBA team about getting access to the information you need.

What's the difference between "git reset" and "git checkout"?

The two commands (reset and checkout) are completely different.

checkout X IS NOT reset --hard X

If X is a branch name, checkout X will change the current branch while reset --hard X will not.

Default Values to Stored Procedure in Oracle

Default values are only used if the arguments are not specified. In your case you did specify the arguments - both were supplied, with a value of NULL. (Yes, in this case NULL is considered a real value :-). Try:

EXEC TEST()

Share and enjoy.

Addendum: The default values for procedure parameters are certainly buried in a system table somewhere (see the SYS.ALL_ARGUMENTS view), but getting the default value out of the view involves extracting text from a LONG field, and is probably going to prove to be more painful than it's worth. The easy way is to add some code to the procedure:

CREATE OR REPLACE PROCEDURE TEST(X IN VARCHAR2 DEFAULT 'P',
                                 Y IN NUMBER DEFAULT 1)
AS
  varX VARCHAR2(32767) := NVL(X, 'P');
  varY NUMBER          := NVL(Y, 1);
BEGIN
  DBMS_OUTPUT.PUT_LINE('X=' || varX || ' -- ' || 'Y=' || varY);
END TEST;

Python Set Comprehension

You can get clean and clear solutions by building the appropriate predicates as helper functions. In other words, use the Python set-builder notation the same way you would write the answer with regular mathematics set-notation.

The whole idea behind set comprehensions is to let us write and reason in code the same way we do mathematics by hand.

With an appropriate predicate in hand, problem 1 simplifies to:

 low_primes = {x for x in range(1, 100) if is_prime(x)}

And problem 2 simplifies to:

 low_prime_pairs = {(x, x+2) for x in range(1,100,2) if is_prime(x) and is_prime(x+2)}

Note how this code is a direct translation of the problem specification, "A Prime Pair is a pair of consecutive odd numbers that are both prime."

P.S. I'm trying to give you the correct problem solving technique without actually giving away the answer to the homework problem.

How to delete images from a private docker registry?

There is also a way you can remove some old images from repository just based on the date when it was created.

To do that enter your docker registry container and get the list of manifest's revisions for some specific repository:

ls -latr /var/lib/registry/docker/registry/v2/repositories/YOUR_REPO/_manifests/revisions/sha256/

The output then may be used within the request (with sha256 prefix):

curl -v --silent -H "Accept: application/vnd.docker.distribution.manifest.v2+json" -X DELETE http://DOCKER_REGISTRY_HOST:5000/v2/YOUR_REPO/manifests/sha256:OUTPUT_LINE

And of course do not forget to execute 'garbage-collect' command after that:

bin/registry garbage-collect /etc/docker/registry/config.yml

Wait for page load in Selenium

This seems to be a serious limitation of WebDriver. Obviously waiting for an element will not imply the page being loaded, in particular the DOM can be fully build (onready state) whereby JS is still executing and CSS and images are still loading.

I believe the simplest solution is to set a JS variable upon the onload event after everything is initialized and check and wait for this JS variable in Selenium.

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

It seems like what you're looking for is a variant on the CSS Holy Grail Layout, but in two columns. Check out the resources at this answer for more information.

How to make a Java thread wait for another thread's output?

This applies to all languages:

You want to have an event/listener model. You create a listener to wait for a particular event. The event would be created (or signaled) in your worker thread. This will block the thread until the signal is received instead of constantly polling to see if a condition is met, like the solution you currently have.

Your situation is one of the most common causes for deadlocks- make sure you signal the other thread regardless of errors that may have occurred. Example- if your application throws an exception- and never calls the method to signal the other that things have completed. This will make it so the other thread never 'wakes up'.

I suggest that you look into the concepts of using events and event handlers to better understand this paradigm before implementing your case.

Alternatively you can use a blocking function call using a mutex- which will cause the thread to wait for the resource to be free. To do this you need good thread synchronization- such as:

Thread-A Locks lock-a
Run thread-B
Thread-B waits for lock-a
Thread-A unlocks lock-a (causing Thread-B to continue)
Thread-A waits for lock-b 
Thread-B completes and unlocks lock-b

javascript - match string against the array of regular expressions

Consider breaking this problem up into two pieces:

  1. filter out the items that match the given regular expression
  2. determine if that filtered list has 0 matches in it
const sampleStringData = ["frog", "pig", "tiger"];

const matches = sampleStringData.filter((animal) => /any.regex.here/.test(animal));

if (matches.length === 0) {
  console.log("No matches");
}

A better way to check if a path exists or not in PowerShell

If you just want an alternative to the cmdlet syntax, specifically for files, use the File.Exists() .NET method:

if(![System.IO.File]::Exists($path)){
    # file with path $path doesn't exist
}

If, on the other hand, you want a general purpose negated alias for Test-Path, here is how you should do it:

# Gather command meta data from the original Cmdlet (in this case, Test-Path)
$TestPathCmd = Get-Command Test-Path
$TestPathCmdMetaData = New-Object System.Management.Automation.CommandMetadata $TestPathCmd

# Use the static ProxyCommand.GetParamBlock method to copy 
# Test-Path's param block and CmdletBinding attribute
$Binding = [System.Management.Automation.ProxyCommand]::GetCmdletBindingAttribute($TestPathCmdMetaData)
$Params  = [System.Management.Automation.ProxyCommand]::GetParamBlock($TestPathCmdMetaData)

# Create wrapper for the command that proxies the parameters to Test-Path 
# using @PSBoundParameters, and negates any output with -not
$WrappedCommand = { 
    try { -not (Test-Path @PSBoundParameters) } catch { throw $_ }
}

# define your new function using the details above
$Function:notexists = '{0}param({1}) {2}' -f $Binding,$Params,$WrappedCommand

notexists will now behave exactly like Test-Path, but always return the opposite result:

PS C:\> Test-Path -Path "C:\Windows"
True
PS C:\> notexists -Path "C:\Windows"
False
PS C:\> notexists "C:\Windows" # positional parameter binding exactly like Test-Path
False

As you've already shown yourself, the opposite is quite easy, just alias exists to Test-Path:

PS C:\> New-Alias exists Test-Path
PS C:\> exists -Path "C:\Windows"
True

How does the communication between a browser and a web server take place?

Communication between a browser and a webserver takes place at so many levels that is close to impossible to answer this question. HTTP plays a role, but HTTP is meaningless without TCP which is meaningless without IP which is meaningless without a physical network on which it sent. Then, there are POST vs GET requests which are similar but enough different to warrant a special dicussion. Sometimes an HTTP request needs to be authenticated, sometimes, it needs not. Mime types should be mentioned. Then, a browser sends a different request if there is a proxy. And then also encodings play a role. So, I guess, the most concise answer to this kind of question is: the browser asks the server for data and the server gives the requested data to the browser.

Where is android studio building my .apk file?

in android 3.1.0 Above use below path to find signed version of APK

home/AndroidStudioProjects/<projedct name>/app/app-release.apk

and in windows

AndroidStudioProjects\{project name}\app\release\app-release.apk

How to check if all of the following items are in a list?

Not OP's case, but - for anyone who wants to assert intersection in dicts and ended up here due to poor googling (e.g. me) - you need to work with dict.items:

>>> a = {'key': 'value'}
>>> b = {'key': 'value', 'extra_key': 'extra_value'}
>>> all(item in a.items() for item in b.items())
True
>>> all(item in b.items() for item in a.items())
False

That's because dict.items returns tuples of key/value pairs, and much like any object in Python, they're interchangeably comparable

Address validation using Google Maps API

Google basis (free) does not provide address verification (Geocoding) as there is no UK postcode license.

This means postcode searches are very in-accurate. The proximity search is very poor, even for town searches, often not recognising locations.

This is why Google have a premier and a enterprise solution which still is more expensive and not as good as business mapping specialists like bIng and Via Michelin who also have API's.

As a free lance developer, so serious business would use Google as the system is weak and really provides a watered down solution.

Better way to cast object to int

Convert.ToInt32(myobject);

This will handle the case where myobject is null and return 0, instead of throwing an exception.

How to create circular ProgressBar in android?

It's easy to create this yourself

In your layout include the following ProgressBar with a specific drawable (note you should get the width from dimensions instead). The max value is important here:

<ProgressBar
    android:id="@+id/progressBar"
    style="?android:attr/progressBarStyleHorizontal"
    android:layout_width="150dp"
    android:layout_height="150dp"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:max="500"
    android:progress="0"
    android:progressDrawable="@drawable/circular" />

Now create the drawable in your resources with the following shape. Play with the radius (you can use innerRadius instead of innerRadiusRatio) and thickness values.

circular (Pre Lollipop OR API Level < 21)

   <shape
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
   </shape>

circular ( >= Lollipop OR API Level >= 21)

    <shape
        android:useLevel="true"
        android:innerRadiusRatio="2.3"
        android:shape="ring"
        android:thickness="3.8sp" >
        <solid android:color="@color/yourColor" />
     </shape>

useLevel is "false" by default in API Level 21 (Lollipop) .

Start Animation

Next in your code use an ObjectAnimator to animate the progress field of the ProgessBar of your layout.

ProgressBar progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
ObjectAnimator animation = ObjectAnimator.ofInt(progressBar, "progress", 0, 500); // see this max value coming back here, we animate towards that value
animation.setDuration(5000); // in milliseconds
animation.setInterpolator(new DecelerateInterpolator());
animation.start();

Stop Animation

progressBar.clearAnimation();

P.S. unlike examples above, it give smooth animation.

How to make an embedded video not autoplay

fenomas's answer was really good...it got me off of looking into the HTML code. I know that jb was looking for something that works in Captivate, but the question is broad enough to include people working out of Flash (I'm using CS5), so I thought I'd throw in the specific answer to my situation here.

If you're using the stock Adobe FLVPlayback component in Flash (you probably are if you used File > Import > Import Video...), there's an option in the Properties panel, under Component Parameters. Look for 'autoPlay' and uncheck it. That'll stop autoplay when the page loads!

R error "sum not meaningful for factors"

The error comes when you try to call sum(x) and x is a factor.

What that means is that one of your columns, though they look like numbers are actually factors (what you are seeing is the text representation)

simple fix, convert to numeric. However, it needs an intermeidate step of converting to character first. Use the following:

family[, 1] <- as.numeric(as.character( family[, 1] ))
family[, 3] <- as.numeric(as.character( family[, 3] ))

For a detailed explanation of why the intermediate as.character step is needed, take a look at this question: How to convert a factor to integer\numeric without loss of information?

FirstOrDefault: Default value other than null

I know its been a while but Ill add to this, based on the most popular answer but with a little extension Id like to share the below:

static class ExtensionsThatWillAppearOnIEnumerables
{
    public static T FirstOr<T>(this IEnumerable<T> source, Func<T, bool> predicate, Func<T> alternate)
    {
        var thing = source.FirstOrDefault(predicate);
        if (thing != null)
            return thing;
        return alternate();
    }
}

This allows me to call it inline as such with my own example I was having issues with:

_controlDataResolvers.FirstOr(x => x.AppliesTo(item.Key), () => newDefaultResolver()).GetDataAsync(conn, item.ToList())

So for me I just wanted a default resolver to be used inline, I can do my usual check and then pass in a function so a class isn't instantiated even if unused, its a function to execute when required instead!

How can I write a regex which matches non greedy?

The other answers here presuppose that you have a regex engine which supports non-greedy matching, which is an extension introduced in Perl 5 and widely copied to other modern languages; but it is by no means ubiquitous.

Many older or more conservative languages and editors only support traditional regular expressions, which have no mechanism for controlling greediness of the repetition operator * - it always matches the longest possible string.

The trick then is to limit what it's allowed to match in the first place. Instead of .* you seem to be looking for

[^>]*

which still matches as many of something as possible; but the something is not just . "any character", but instead "any character which isn't >".

Depending on your application, you may or may not want to enable an option to permit "any character" to include newlines.

Even if your regular expression engine supports non-greedy matching, it's better to spell out what you actually mean. If this is what you mean, you should probably say this, instead of rely on non-greedy matching to (hopefully, probably) Do What I Mean.

For example, a regular expression with a trailing context after the wildcard like .*?><br/> will jump over any nested > until it finds the trailing context (here, ><br/>) even if that requires straddling multiple > instances and newlines if you let it, where [^>]*><br/> (or even [^\n>]*><br/> if you have to explicitly disallow newline) obviously can't and won't do that.

Of course, this is still not what you want if you need to cope with <img title="quoted string with > in it" src="other attributes"> and perhaps <img title="nested tags">, but at that point, you should finally give up on using regular expressions for this like we all told you in the first place.

How to get local server host and port in Spring Boot?

I have just found a way to get server ip and port easily by using Eureka client library. As I am using it anyway for service registration, it is not an additional lib for me just for this purpose.

You need to add the maven dependency first:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    <version>2.2.2.RELEASE</version>
</dependency>

Then you can use the ApplicationInfoManager service in any of your Spring beans.

@Autowired
private ApplicationInfoManager applicationInfoManager;
...

InstanceInfo applicationInfo = applicationInfoManager.getInfo();

The InstanceInfo object contains all important information about your service, like IP address, port, hostname, etc.

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received type undefined raised when starting react app

I had the same issue running it in my pipeline.

For me, the issue was that I was using node version v10.0.0 in my docker container.

Updating it to v14.7.0 solved it for me

Install a Windows service using a Windows command prompt?

Nothing wrong with SC Create command. Just you need to know the correct args :

SC CREATE "MySVC" binpath= "D:\Me\Services\MySVC\MySVC.exe"

How can I query for null values in entity framework?

Unfortunately in Entity Framework 5 DbContext the issue is still not fixed.

I used this workaround (works with MSSQL 2012 but ANSI NULLS setting might be deprecated in any future MSSQL version).

public class Context : DbContext
{

    public Context()
        : base("name=Context")
    {
        this.Database.Connection.StateChange += Connection_StateChange;
    }

    void Connection_StateChange(object sender, System.Data.StateChangeEventArgs e)
    {
        // Set ANSI_NULLS OFF when any connection is opened. This is needed because of a bug in Entity Framework
        // that is not fixed in EF 5 when using DbContext.
        if (e.CurrentState == System.Data.ConnectionState.Open)
        {
            var connection = (System.Data.Common.DbConnection)sender;
            using (var cmd = connection.CreateCommand())
            {
                cmd.CommandText = "SET ANSI_NULLS OFF";
                cmd.ExecuteNonQuery();
            }
        }
    }
}

It should be noted that it is a dirty workaround but it is one that can be implemented very quickly and works for all queries.

Get root view from current activity

I tested this in android 4.0.3, only:

getWindow().getDecorView().getRootView()

give the same view what we get from

anyview.getRootView();

com.android.internal.policy.impl.PhoneWindow$DecorView@#########

and

getWindow().getDecorView().findViewById(android.R.id.content)

giving child of its

android.widget.FrameLayout@#######

Please confirm.

Open soft keyboard programmatically

This is works

<activity
    ...
    android:windowSoftInputMode="stateVisible" >
</activity>

or

getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);

Calculate execution time of a SQL query?

You can use

SET STATISTICS TIME { ON | OFF }

Displays the number of milliseconds required to parse, compile, and execute each statement

When SET STATISTICS TIME is ON, the time statistics for a statement are displayed. When OFF, the time statistics are not displayed

USE AdventureWorks2012;  
GO         
SET STATISTICS TIME ON;  
GO  
SELECT ProductID, StartDate, EndDate, StandardCost   
FROM Production.ProductCostHistory  
WHERE StandardCost < 500.00;  
GO  
SET STATISTICS TIME OFF;  
GO  

Fade In on Scroll Down, Fade Out on Scroll Up - based on element position in window

The reason your attempt wasn't working, is because the two animations (fade-in and fade-out) were working against each other.

Right before an object became visible, it was still invisible and so the animation for fading-out would run. Then, the fraction of a second later when that same object had become visible, the fade-in animation would try to run, but the fade-out was still running. So they would work against each other and you would see nothing.

Eventually the object would become visible (most of the time), but it would take a while. And if you would scroll down by using the arrow-button at the button of the scrollbar, the animation would sort of work, because you would scroll using bigger increments, creating less scroll-events.


Enough explanation, the solution (JS, CSS, HTML):

_x000D_
_x000D_
$(window).on("load",function() {_x000D_
  $(window).scroll(function() {_x000D_
    var windowBottom = $(this).scrollTop() + $(this).innerHeight();_x000D_
    $(".fade").each(function() {_x000D_
      /* Check the location of each desired element */_x000D_
      var objectBottom = $(this).offset().top + $(this).outerHeight();_x000D_
      _x000D_
      /* If the element is completely within bounds of the window, fade it in */_x000D_
      if (objectBottom < windowBottom) { //object comes into view (scrolling down)_x000D_
        if ($(this).css("opacity")==0) {$(this).fadeTo(500,1);}_x000D_
      } else { //object goes out of view (scrolling up)_x000D_
        if ($(this).css("opacity")==1) {$(this).fadeTo(500,0);}_x000D_
      }_x000D_
    });_x000D_
  }).scroll(); //invoke scroll-handler on page-load_x000D_
});
_x000D_
.fade {_x000D_
  margin: 50px;_x000D_
  padding: 50px;_x000D_
  background-color: lightgreen;_x000D_
  opacity: 1;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>_x000D_
_x000D_
<div>_x000D_
  <div class="fade">Fade In 01</div>_x000D_
  <div class="fade">Fade In 02</div>_x000D_
  <div class="fade">Fade In 03</div>_x000D_
  <div class="fade">Fade In 04</div>_x000D_
  <div class="fade">Fade In 05</div>_x000D_
  <div class="fade">Fade In 06</div>_x000D_
  <div class="fade">Fade In 07</div>_x000D_
  <div class="fade">Fade In 08</div>_x000D_
  <div class="fade">Fade In 09</div>_x000D_
  <div class="fade">Fade In 10</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_ (fiddle: http://jsfiddle.net/eLwex993/2/)

  • I wrapped the fade-codeline in an if-clause: if ($(this).css("opacity")==0) {...}. This makes sure the object is only faded in when the opacity is 0. Same goes for fading out. And this prevents the fade-in and fade-out from working against each other, because now there's ever only one of the two running at one time on an object.
  • I changed .animate() to .fadeTo(). It's jQuery's specialized function for opacity, a lot shorter to write and probably lighter than animate.
  • I changed .position() to .offset(). This always calculates relative to the body, whereas position is relative to the parent. For your case I believe offset is the way to go.
  • I changed $(window).height() to $(window).innerHeight(). The latter is more reliable in my experience.
  • Directly after the scroll-handler, I invoke that handler once on page-load with $(window).scroll();. Now you can give all desired objects on the page the .fade class, and objects that should be invisible at page-load, will be faded out immediately.
  • I removed #container from both HTML and CSS, because (at least for this answer) it isn't necessary. (I thought maybe you needed the height:2000px because you used .position() instead of .offset(), otherwise I don't know. Feel free of course to leave it in your code.)

UPDATE

If you want opacity values other than 0 and 1, use the following code:

_x000D_
_x000D_
$(window).on("load",function() {_x000D_
  function fade(pageLoad) {_x000D_
    var windowBottom = $(window).scrollTop() + $(window).innerHeight();_x000D_
    var min = 0.3;_x000D_
    var max = 0.7;_x000D_
    var threshold = 0.01;_x000D_
    _x000D_
    $(".fade").each(function() {_x000D_
      /* Check the location of each desired element */_x000D_
      var objectBottom = $(this).offset().top + $(this).outerHeight();_x000D_
      _x000D_
      /* If the element is completely within bounds of the window, fade it in */_x000D_
      if (objectBottom < windowBottom) { //object comes into view (scrolling down)_x000D_
        if ($(this).css("opacity")<=min+threshold || pageLoad) {$(this).fadeTo(500,max);}_x000D_
      } else { //object goes out of view (scrolling up)_x000D_
        if ($(this).css("opacity")>=max-threshold || pageLoad) {$(this).fadeTo(500,min);}_x000D_
      }_x000D_
    });_x000D_
  } fade(true); //fade elements on page-load_x000D_
  $(window).scroll(function(){fade(false);}); //fade elements on scroll_x000D_
});
_x000D_
.fade {_x000D_
  margin: 50px;_x000D_
  padding: 50px;_x000D_
  background-color: lightgreen;_x000D_
  opacity: 1;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>_x000D_
_x000D_
<div>_x000D_
  <div class="fade">Fade In 01</div>_x000D_
  <div class="fade">Fade In 02</div>_x000D_
  <div class="fade">Fade In 03</div>_x000D_
  <div class="fade">Fade In 04</div>_x000D_
  <div class="fade">Fade In 05</div>_x000D_
  <div class="fade">Fade In 06</div>_x000D_
  <div class="fade">Fade In 07</div>_x000D_
  <div class="fade">Fade In 08</div>_x000D_
  <div class="fade">Fade In 09</div>_x000D_
  <div class="fade">Fade In 10</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_ (fiddle: http://jsfiddle.net/eLwex993/3/)

  • I added a threshold to the if-clause, see explanation below.
  • I created variables for the threshold and for min/max at the start of the function. In the rest of the function these variables are referenced. This way, if you ever want to change the values again, you only have to do it in one place.
  • I also added || pageLoad to the if-clause. This was necessary to make sure all objects are faded to the correct opacity on page-load. pageLoad is a boolean that is send along as an argument when fade() is invoked.
    I had to put the fade-code inside the extra function fade() {...}, in order to be able to send along the pageLoad boolean when the scroll-handler is invoked.
    I did't see any other way to do this, if anyone else does, please leave a comment.

Explanation:
The reason the code in your fiddle didn't work, is because the actual opacity values are always a little off from the value you set it to. So if you set the opacity to 0.3, the actual value (in this case) is 0.300000011920929. That's just one of those little bugs you have to learn along the way by trail and error. That's why this if-clause won't work: if ($(this).css("opacity") == 0.3) {...}.

I added a threshold, to take that difference into account: == 0.3 becomes <= 0.31.
(I've set the threshold to 0.01, this can be changed of course, just as long as the actual opacity will fall between the set value and this threshold.)

The operators are now changed from == to <= and >=.


UPDATE 2:

If you want to fade the elements based on their visible percentage, use the following code:

_x000D_
_x000D_
$(window).on("load",function() {_x000D_
  function fade(pageLoad) {_x000D_
    var windowTop=$(window).scrollTop(), windowBottom=windowTop+$(window).innerHeight();_x000D_
    var min=0.3, max=0.7, threshold=0.01;_x000D_
    _x000D_
    $(".fade").each(function() {_x000D_
      /* Check the location of each desired element */_x000D_
      var objectHeight=$(this).outerHeight(), objectTop=$(this).offset().top, objectBottom=$(this).offset().top+objectHeight;_x000D_
      _x000D_
      /* Fade element in/out based on its visible percentage */_x000D_
      if (objectTop < windowTop) {_x000D_
        if (objectBottom > windowTop) {$(this).fadeTo(0,min+((max-min)*((objectBottom-windowTop)/objectHeight)));}_x000D_
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}_x000D_
      } else if (objectBottom > windowBottom) {_x000D_
        if (objectTop < windowBottom) {$(this).fadeTo(0,min+((max-min)*((windowBottom-objectTop)/objectHeight)));}_x000D_
        else if ($(this).css("opacity")>=min+threshold || pageLoad) {$(this).fadeTo(0,min);}_x000D_
      } else if ($(this).css("opacity")<=max-threshold || pageLoad) {$(this).fadeTo(0,max);}_x000D_
    });_x000D_
  } fade(true); //fade elements on page-load_x000D_
  $(window).scroll(function(){fade(false);}); //fade elements on scroll_x000D_
});
_x000D_
.fade {_x000D_
  margin: 50px;_x000D_
  padding: 50px;_x000D_
  background-color: lightgreen;_x000D_
  opacity: 1;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>_x000D_
_x000D_
<div>_x000D_
  <div class="fade">Fade In 01</div>_x000D_
  <div class="fade">Fade In 02</div>_x000D_
  <div class="fade">Fade In 03</div>_x000D_
  <div class="fade">Fade In 04</div>_x000D_
  <div class="fade">Fade In 05</div>_x000D_
  <div class="fade">Fade In 06</div>_x000D_
  <div class="fade">Fade In 07</div>_x000D_
  <div class="fade">Fade In 08</div>_x000D_
  <div class="fade">Fade In 09</div>_x000D_
  <div class="fade">Fade In 10</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_ (fiddle: http://jsfiddle.net/eLwex993/5/)

Is there a way to select sibling nodes?

var childNodeArray = document.getElementById('somethingOtherThanid').childNodes;

C++ Array of pointers: delete or delete []?

It would make sens if your code was like this:

#include <iostream>

using namespace std;

class Monster
{
public:
        Monster() { cout << "Monster!" << endl; }
        virtual ~Monster() { cout << "Monster Died" << endl; }
};

int main(int argc, const char* argv[])
{
        Monster *mon = new Monster[6];

        delete [] mon;

        return 0;
}

Find and replace string values in list

You can use, for example:

words = [word.replace('[br]','<br />') for word in words]

jQuery AJAX Character Encoding

$str=iconv("windows-1250","UTF-8",$str);

what helped me on the eventually

PHP move_uploaded_file() error?

How can I know that what is the problem

Easy. Refer to the error log of the webserver.

how can I get the actual problem to display to the user ?

NEVER do it.
An average user will unerstand nothing of this error.
A malicious user should get no feedback, especially in a form of very informative error message.

Just show a page with excuses.

If you don't have access to the server's error log, your task become more complicated.
There are several ways to get in touch with error messages.

To display error messages on screen you can add these lines to the code

ini_set('display_errors',1);
error_reporting(E_ALL);

or to make custom error logfile

ini_set('log_errors',1);
ini_set('error_log','/absolute/path/tp/log_file');

and there are some other ways.
but you must understand that without actual error message you can't move. It's hard to be blind in the dark

How to only find files in a given directory, and ignore subdirectories using bash

If you just want to limit the find to the first level you can do:

 find /dev -maxdepth 1 -name 'abc-*'

... or if you particularly want to exclude the .udev directory, you can do:

 find /dev -name '.udev' -prune -o -name 'abc-*' -print

Get random item from array

echo $items[array_rand($items)];

array_rand()

Frame Buster Buster ... buster code needed

You could improve the whole idea by using the postMessage() method to allow some domains to access and display your content while blocking all the others. First, the container-parent must introduce itself by posting a message to the contentWindow of the iframe that is trying to display your page. And your page must be ready to accept messages,

window.addEventListener("message", receiveMessage, false);

function receiveMessage(event) {
  // Use event.origin here like
  if(event.origin == "https://perhapsyoucantrustthisdomain.com"){
  // code here to block/unblock access ... a method like the one in user1646111's post can be good.
  }
  else{
  // code here to block/unblock access ... a method like the one in user1646111's post can be good.
  }
}

Finally don't forget to wrap things inside functions that will wait for load events.

Is there a command for formatting HTML in the Atom editor?

  1. Go to "Packages" in atom editor.
  2. Then in "Packages" view choose "Settings View".
  3. Choose "Install Packages/Themes".
  4. Search for "Atom Beautify" and install it.

Easy way to concatenate two byte arrays

Most straightforward:

byte[] c = new byte[a.length + b.length];
System.arraycopy(a, 0, c, 0, a.length);
System.arraycopy(b, 0, c, a.length, b.length);

How to get just the parent directory name of a specific file

From java 7 I would prefer to use Path. You only need to put path into:

Path dddDirectoryPath = Paths.get("C:/aaa/bbb/ccc/ddd/test.java");

and create some get method:

public String getLastDirectoryName(Path directoryPath) {
   int nameCount = directoryPath.getNameCount();
   return directoryPath.getName(nameCount - 1);
}

How do you embed binary data in XML?

I usually encode the binary data with MIME Base64 or URL encoding.

How to convert R Markdown to PDF?

If you don't want to install anything you can output html. Then open the html file - it should open in a browser window, then right click to print. In the print window, select "save as pdf" in the bottom right hand corner if you're on a Mac. Voila!

How to clear Tkinter Canvas?

Yes, I believe you are creating thousands of objects. If you're looking for an easy way to delete a bunch of them at once, use canvas tags described here. This lets you perform the same operation (such as deletion) on a large number of objects.

What is REST? Slightly confused

REST is a software design pattern typically used for web applications. In layman's terms this means that it is a commonly used idea used in many different projects. It stands for REpresentational State Transfer. The basic idea of REST is treating objects on the server-side (as in rows in a database table) as resources than can be created or destroyed.

The most basic way of thinking about REST is as a way of formatting the URLs of your web applications. For example, if your resource was called "posts", then:

/posts Would be how a user would access ALL the posts, for displaying.

/posts/:id Would be how a user would access and view an individual post, retrieved based on their unique id.

/posts/new Would be how you would display a form for creating a new post.

Sending a POST request to /users would be how you would actually create a new post on the database level.

Sending a PUT request to /users/:id would be how you would update the attributes of a given post, again identified by a unique id.

Sending a DELETE request to /users/:id would be how you would delete a given post, again identified by a unique id.

As I understand it, the REST pattern was mainly popularized (for web apps) by the Ruby on Rails framework, which puts a big emphasis on RESTful routes. I could be wrong about that though.

I may not be the most qualified to talk about it, but this is how I've learned it (specifically for Rails development).

When someone refers to a "REST api," generally what they mean is an api that uses RESTful urls for retrieving data.

Check a collection size with JSTL

use ${fn:length(companies) > 0} to check the size. This returns a boolean

How do I return a string from a regex match in python?

Considering there might be several img tags I would recommend re.findall:

import re

with open("sample.txt", 'r') as f_in, open('writetest.txt', 'w') as f_out:
    for line in f_in:
        for img in re.findall('<img[^>]+>', line):
            print >> f_out, "yo it's a {}".format(img)

How to run batch file from network share without "UNC path are not supported" message?

Editing Windows registries is not worth it and not safe, use Map network drive and load the network share as if it's loaded from one of your local drives.

enter image description here

CREATE TABLE LIKE A1 as A2

Based on http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html

What about:

Create Table New_Users Select * from Old_Users Where 1=2;

and if that doesn't work, just select a row and truncate after creation:

Create table New_Users select * from Old_Users Limit 1;
Truncate Table New_Users;

EDIT:

I noticed your comment below about needing indexes, etc. Try:

show create table old_users;
#copy the output ddl statement into a text editor and change the table name to new_users
#run the new query
insert into new_users(id,name...) select id,name,... form old_users group by id;

That should do it. It appears that you are doing this to get rid of duplicates? In which case you may want to put a unique index on id. if it's a primary key, this should already be in place. You can either:

#make primary key
alter table new_users add primary key (id);
#make unique
create unique index idx_new_users_id_uniq on new_users (id);

Using Cookie in Asp.Net Mvc 4

userCookie.Expires.AddDays(365); 

This line of code doesn't do anything. It is the equivalent of:

DateTime temp = userCookie.Expires.AddDays(365); 
//do nothing with temp

You probably want

userCookie.Expires = DateTime.Now.AddDays(365); 

Printing hexadecimal characters in C

Try something like this:

int main()
{
    printf("%x %x %x %x %x %x %x %x\n",
        0xC0, 0xC0, 0x61, 0x62, 0x63, 0x31, 0x32, 0x33);
}

Which produces this:

$ ./foo 
c0 c0 61 62 63 31 32 33

How to pass an ArrayList to a varargs method parameter?

Source article: Passing a list as an argument to a vararg method


Use the toArray(T[] arr) method.

.getMap(locations.toArray(new WorldLocation[locations.size()]))

(toArray(new WorldLocation[0]) also works, but you would allocate a zero-length array for no reason.)


Here's a complete example:

public static void method(String... strs) {
    for (String s : strs)
        System.out.println(s);
}

...
    List<String> strs = new ArrayList<String>();
    strs.add("hello");
    strs.add("world");
    
    method(strs.toArray(new String[strs.size()]));
    //     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
...

How to configure custom PYTHONPATH with VM and PyCharm?

For PyCharm 5 (or 2016.1), you can:

  1. select Preferences > Project Interpreter
  2. to the right of interpreter selector there is a "..." button, click it
  3. select "more..."
  4. pop up a new "Project Interpreters" window
  5. select the rightest button (named "show paths for the selected interpreter")
  6. pop up a "Interpreter Paths" window
  7. click the "+" buttom > select your desired PYTHONPATH directory (the folder which contains python modules) and click OK
  8. Done! Enjoy it!

enter image description here

enter image description here

enter image description here enter image description here

Setting the selected attribute on a select list using jQuery

You can use pure DOM. See http://www.w3schools.com/htmldom/prop_select_selectedindex.asp

document.getElementById('dropdown').selectedIndex = 1;

but jQuery can help:

$('#dropdown').selectedIndex = 1;

How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)

On Mavericks I install it from the node pkg (from nodejs site) and I uninstall it so I can re-install using brew. I only run 4 commands in the terminal:

  1. sudo rm -rf /usr/local/lib/node_modules/npm/
  2. brew uninstall node
  3. brew doctor
  4. brew cleanup --prune-prefix

If there is still a node installation, repeat step 2. After all is ok, I install using brew install node

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

The main reason is that classic C casts make no distinction between what we call static_cast<>(), reinterpret_cast<>(), const_cast<>(), and dynamic_cast<>(). These four things are completely different.

A static_cast<>() is usually safe. There is a valid conversion in the language, or an appropriate constructor that makes it possible. The only time it's a bit risky is when you cast down to an inherited class; you must make sure that the object is actually the descendant that you claim it is, by means external to the language (like a flag in the object). A dynamic_cast<>() is safe as long as the result is checked (pointer) or a possible exception is taken into account (reference).

A reinterpret_cast<>() (or a const_cast<>()) on the other hand is always dangerous. You tell the compiler: "trust me: I know this doesn't look like a foo (this looks as if it isn't mutable), but it is".

The first problem is that it's almost impossible to tell which one will occur in a C-style cast without looking at large and disperse pieces of code and knowing all the rules.

Let's assume these:

class CDerivedClass : public CMyBase {...};
class CMyOtherStuff {...} ;

CMyBase  *pSomething; // filled somewhere

Now, these two are compiled the same way:

CDerivedClass *pMyObject;
pMyObject = static_cast<CDerivedClass*>(pSomething); // Safe; as long as we checked

pMyObject = (CDerivedClass*)(pSomething); // Same as static_cast<>
                                     // Safe; as long as we checked
                                     // but harder to read

However, let's see this almost identical code:

CMyOtherStuff *pOther;
pOther = static_cast<CMyOtherStuff*>(pSomething); // Compiler error: Can't convert

pOther = (CMyOtherStuff*)(pSomething);            // No compiler error.
                                                  // Same as reinterpret_cast<>
                                                  // and it's wrong!!!

As you can see, there is no easy way to distinguish between the two situations without knowing a lot about all the classes involved.

The second problem is that the C-style casts are too hard to locate. In complex expressions it can be very hard to see C-style casts. It is virtually impossible to write an automated tool that needs to locate C-style casts (for example a search tool) without a full blown C++ compiler front-end. On the other hand, it's easy to search for "static_cast<" or "reinterpret_cast<".

pOther = reinterpret_cast<CMyOtherStuff*>(pSomething);
      // No compiler error.
      // but the presence of a reinterpret_cast<> is 
      // like a Siren with Red Flashing Lights in your code.
      // The mere typing of it should cause you to feel VERY uncomfortable.

That means that, not only are C-style casts more dangerous, but it's a lot harder to find them all to make sure that they are correct.

Why does corrcoef return a matrix?

You can use the following function to return only the correlation coefficient:

def pearson_r(x, y):
"""Compute Pearson correlation coefficient between two arrays."""

   # Compute correlation matrix
   corr_mat = np.corrcoef(x, y)

   # Return entry [0,1]
   return corr_mat[0,1]

Implementing SearchView in action bar

If anyone else is having a nullptr on the searchview variable, I found out that the item setup is a tiny bit different:

old:

android:showAsAction="ifRoom"
android:actionViewClass="android.widget.SearchView"

new:

app:showAsAction="ifRoom|collapseActionView"
app:actionViewClass="androidx.appcompat.widget.SearchView"

pre-android x:

app:showAsAction="ifRoom|collapseActionView"
app:actionViewClass="android.support.v7.widget.SearchView"

For more information, it's updated documentation is located here.

Incrementing a variable inside a Bash loop

You are using USCOUNTER in a subshell, that's why the variable is not showing in the main shell.

Instead of cat FILE | while ..., do just a while ... done < $FILE. This way, you avoid the common problem of I set variables in a loop that's in a pipeline. Why do they disappear after the loop terminates? Or, why can't I pipe data to read?:

while read country _; do
  if [ "US" = "$country" ]; then
        USCOUNTER=$(expr $USCOUNTER + 1)
        echo "US counter $USCOUNTER"
  fi
done < "$FILE"

Note I also replaced the `` expression with a $().

I also replaced while read line; do country=$(echo "$line" | cut -d' ' -f1) with while read country _. This allows you to say while read var1 var2 ... varN where var1 contains the first word in the line, $var2 and so on, until $varN containing the remaining content.

c# .net change label text

Old question, but I had this issue as well, so after assigning the Text property, calling Refresh() will update the text.

Label1.Text = "Du har nu lånat filmen:" + test;
Refresh();

How to implement "select all" check box in HTML?

Here is a backbone.js implementation:

events: {
    "click #toggleChecked" : "toggleChecked"
},
toggleChecked: function(event) {

    var checkboxes = document.getElementsByName('options');
    for(var i=0; i<checkboxes.length; i++) {
        checkboxes[i].checked = event.currentTarget.checked;
    }

},

Correct modification of state arrays in React.js

This worked for me to add an array within an array

this.setState(prevState => ({
    component: prevState.component.concat(new Array(['new', 'new']))
}));

Difference between InvariantCulture and Ordinal string comparison

Invariant is a linguistically appropriate type of comparison.
Ordinal is a binary type of comparison. (faster)
See http://www.siao2.com/2004/12/29/344136.aspx

What does an exclamation mark before a cell reference mean?

When entered as the reference of a Named range, it refers to range on the sheet the named range is used on.

For example, create a named range MyName refering to =SUM(!B1:!K1)

Place a formula on Sheet1 =MyName. This will sum Sheet1!B1:K1

Now place the same formula (=MyName) on Sheet2. That formula will sum Sheet2!B1:K1

Note: (as pnuts commented) this and the regular SheetName!B1:K1 format are relative, so reference different cells as the =MyName formula is entered into different cells.

How to install Android app on LG smart TV?

Thanks for the research FIRESTICK is a solution for non Android based but there's another one Im using if you guys want to try it let me know...

LG, VIZIO, SAMSUNG and PANASONIC TVs are not android based, and you cannot run APKs off of them... You should just buy a fire stick and call it a day. The only TVs that are android-based, and you can install APKs are: SONY, PHILIPS and SHARP, PHILCO and TOSHIBA.

python requests file upload

If upload_file is meant to be the file, use:

files = {'upload_file': open('file.txt','rb')}
values = {'DB': 'photcat', 'OUT': 'csv', 'SHORT': 'short'}

r = requests.post(url, files=files, data=values)

and requests will send a multi-part form POST body with the upload_file field set to the contents of the file.txt file.

The filename will be included in the mime header for the specific field:

>>> import requests
>>> open('file.txt', 'wb')  # create an empty demo file
<_io.BufferedWriter name='file.txt'>
>>> files = {'upload_file': open('file.txt', 'rb')}
>>> print(requests.Request('POST', 'http://example.com', files=files).prepare().body.decode('ascii'))
--c226ce13d09842658ffbd31e0563c6bd
Content-Disposition: form-data; name="upload_file"; filename="file.txt"


--c226ce13d09842658ffbd31e0563c6bd--

Note the filename="file.txt" parameter.

You can use a tuple for the files mapping value, with between 2 and 4 elements, if you need more control. The first element is the filename, followed by the contents, and an optional content-type header value and an optional mapping of additional headers:

files = {'upload_file': ('foobar.txt', open('file.txt','rb'), 'text/x-spam')}

This sets an alternative filename and content type, leaving out the optional headers.

If you are meaning the whole POST body to be taken from a file (with no other fields specified), then don't use the files parameter, just post the file directly as data. You then may want to set a Content-Type header too, as none will be set otherwise. See Python requests - POST data from a file.

The cast to value type 'Int32' failed because the materialized value is null

I was also facing the same problem and solved through making column as nullable using "?" operator.

Sequnce = db.mstquestionbanks.Where(x => x.IsDeleted == false && x.OrignalFormID == OriginalFormIDint).Select(x=><b>(int?)x.Sequence</b>).Max().ToString();

Sometimes null is returned.

ExpressJS How to structure an application?

I think it's a great way to do it. Not limited to express but I've seen quite a number of node.js projects on github doing the same thing. They take out the configuration parameters + smaller modules (in some cases every URI) are factored in separate files.

I would recommend going through express-specific projects on github to get an idea. IMO the way you are doing is correct.

How to change folder with git bash?

Right clicking a specific folder can help ease your pain than just by typing the whole directory. Right click + clicking s or Right click and then click "GIT bash here"

Hope this seems helpful

DTO and DAO concepts and MVC

DTO is an abbreviation for Data Transfer Object, so it is used to transfer the data between classes and modules of your application.

  • DTO should only contain private fields for your data, getters, setters, and constructors.
  • DTO is not recommended to add business logic methods to such classes, but it is OK to add some util methods.

DAO is an abbreviation for Data Access Object, so it should encapsulate the logic for retrieving, saving and updating data in your data storage (a database, a file-system, whatever).

Here is an example of how the DAO and DTO interfaces would look like:

interface PersonDTO {
    String getName();
    void setName(String name);
    //.....
}

interface PersonDAO {
    PersonDTO findById(long id);
    void save(PersonDTO person);
    //.....
}

The MVC is a wider pattern. The DTO/DAO would be your model in the MVC pattern.
It tells you how to organize the whole application, not just the part responsible for data retrieval.

As for the second question, if you have a small application it is completely OK, however, if you want to follow the MVC pattern it would be better to have a separate controller, which would contain the business logic for your frame in a separate class and dispatch messages to this controller from the event handlers.
This would separate your business logic from the view.

How can I add reflection to a C++ application?

There are two kinds of reflection swimming around.

  1. Inspection by iterating over members of a type, enumerating its methods and so on.

    This is not possible with C++.
  2. Inspection by checking whether a class-type (class, struct, union) has a method or nested type, is derived from another particular type.

    This kind of thing is possible with C++ using template-tricks. Use boost::type_traits for many things (like checking whether a type is integral). For checking for the existance of a member function, use Is it possible to write a template to check for a function's existence? . For checking whether a certain nested type exists, use plain SFINAE .

If you are rather looking for ways to accomplish 1), like looking how many methods a class has, or like getting the string representation of a class id, then i'm afraid there is no Standard C++ way of doing this. You have to use either

  • A Meta Compiler like the Qt Meta Object Compiler which translates your code adding additional meta informations.
  • A Framework constisting of macros that allow you to add the required meta-informations. You would need to tell the framework all methods, the class-names, base-classes and everything it needs.

C++ is made with speed in mind. If you want high-level inspection, like C# or Java has, then I'm afraid i have to tell you there is no way without some effort.

Query-string encoding of a Javascript Object

Just another way (no recursive object):

   getQueryString = function(obj)
   {
      result = "";

      for(param in obj)
         result += ( encodeURIComponent(param) + '=' + encodeURIComponent(obj[param]) + '&' );

      if(result) //it's not empty string when at least one key/value pair was added. In such case we need to remove the last '&' char
         result = result.substr(0, result.length - 1); //If length is zero or negative, substr returns an empty string [ref. http://msdn.microsoft.com/en-us/library/0esxc5wy(v=VS.85).aspx]

      return result;
   }

alert( getQueryString({foo: "hi there", bar: 123, quux: 2 }) );

CSS table layout: why does table-row not accept a margin?

Have you tried setting the bottom margin to .row div, i.e. to your "cells"? When you work with actual HTML tables, you cannot set margins to rows, too - only to cells.

Import data.sql MySQL Docker Container

You can run a container setting a shared directory (-v volume), and then run bash in that container. After this, you can interactively use mysql-client to execute the .sql file, from inside the container. obs: /my-host-dir/shared-dir is the .sql location in the host system.

docker run --detach --name=test-mysql -p host-port:container-port  --env="MYSQL_ROOT_PASSWORD=my-root-pswd" -v /my-host-dir/shared-dir:/container-dir mysql:latest


docker exec -it test-mysql bash

Inside the container...

mysql -p < /container-dir/file.sql 

Custom parameters:

  • test-mysql (container name)
  • host-port and container-port
  • my-root-pswd (mysql root password)
  • /my-host-dir/shared-dir and /container-dir (the host directory that will be mounted in the container, and the container location of the shared directory)

Path of currently executing powershell script

From Get-ScriptDirectory to the Rescue blog entry ...

function Get-ScriptDirectory
{
  $Invocation = (Get-Variable MyInvocation -Scope 1).Value
  Split-Path $Invocation.MyCommand.Path
}

PHP Get Site URL Protocol - http vs https

$protocal = 'http';
if ($_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || $_SERVER['HTTPS'] == 'on') {$protocal = 'https';}


echo $protocal;

Using Address Instead Of Longitude And Latitude With Google Maps API

var geocoder;
var map;
function initialize() {
geocoder = new google.maps.Geocoder();
var latlng = new google.maps.LatLng(-34.397, 150.644);
var mapOptions = {
  zoom: 8,
  center: latlng
}
map = new google.maps.Map(document.getElementById('map'), mapOptions);
}

function codeAddress() {
var address = document.getElementById('address').value;
geocoder.geocode( { 'address': address}, function(results, status) {
  if (status == 'OK') {
    map.setCenter(results[0].geometry.location);
    var marker = new google.maps.Marker({
        map: map,
        position: results[0].geometry.location
    });
  } else {
    alert('Geocode was not successful for the following reason: ' + status);
  }
});
}

<body onload="initialize()">
 <div id="map" style="width: 320px; height: 480px;"></div>
 <div>
   <input id="address" type="textbox" value="Sydney, NSW">
   <input type="button" value="Encode" onclick="codeAddress()">
 </div>
</body>

Or refer to the documentation https://developers.google.com/maps/documentation/javascript/geocoding

How do I disable a jquery-ui draggable?

In the case of a dialog, it has a property called draggable, set it to false.

$("#yourDialog").dialog({
    draggable: false
});

Eventhough the question is old, i tried the proposed solution and it did not work for the dialog. Hope this may help others like me.

Kill all processes for a given user

Just (temporarily) killed my Macbook with

killall -u pu -m .

where pu is my userid. Watch the dot at the end of the command.

Also try

pkill -u pu

or

ps -o pid -u pu | xargs kill -1

Qt Creator color scheme

Linux, Qt Creator >= 3.4:

You could edit theese themes:

/usr/share/qtcreator/themes/default.creatortheme
/usr/share/qtcreator/themes/dark.creatortheme

Can't install via pip because of egg_info error

I'll add this in here as my problem had something todo with my virtualenv:

I hadn't activated my virtual environment and was trying to install my requirements, this ultimately led to my install failing and throwing this error message.

So make sure you activate your virtualenv!

what is the most efficient way of counting occurrences in pandas?

I think df['word'].value_counts() should serve. By skipping the groupby machinery, you'll save some time. I'm not sure why count should be much slower than max. Both take some time to avoid missing values. (Compare with size.)

In any case, value_counts has been specifically optimized to handle object type, like your words, so I doubt you'll do much better than that.

How to change color of SVG image using CSS (jQuery SVG image replacement)?

Style

svg path {
    fill: #000;
}

Script

$(document).ready(function() {
    $('img[src$=".svg"]').each(function() {
        var $img = jQuery(this);
        var imgURL = $img.attr('src');
        var attributes = $img.prop("attributes");

        $.get(imgURL, function(data) {
            // Get the SVG tag, ignore the rest
            var $svg = jQuery(data).find('svg');

            // Remove any invalid XML tags
            $svg = $svg.removeAttr('xmlns:a');

            // Loop through IMG attributes and apply on SVG
            $.each(attributes, function() {
                $svg.attr(this.name, this.value);
            });

            // Replace IMG with SVG
            $img.replaceWith($svg);
        }, 'xml');
    });
});

Difference between static, auto, global and local variable in the context of c and c++

There are two separate concepts here:

  • scope, which determines where a name can be accessed, and
  • storage duration, which determines when a variable is created and destroyed.

Local variables (pedantically, variables with block scope) are only accessible within the block of code in which they are declared:

void f() {
    int i;
    i = 1; // OK: in scope
}
void g() {
    i = 2; // Error: not in scope
}

Global variables (pedantically, variables with file scope (in C) or namespace scope (in C++)) are accessible at any point after their declaration:

int i;
void f() {
    i = 1; // OK: in scope
}
void g() {
    i = 2; // OK: still in scope
}

(In C++, the situation is more complicated since namespaces can be closed and reopened, and scopes other than the current one can be accessed, and names can also have class scope. But that's getting very off-topic.)

Automatic variables (pedantically, variables with automatic storage duration) are local variables whose lifetime ends when execution leaves their scope, and are recreated when the scope is reentered.

for (int i = 0; i < 5; ++i) {
    int n = 0;
    printf("%d ", ++n);  // prints 1 1 1 1 1  - the previous value is lost
}

Static variables (pedantically, variables with static storage duration) have a lifetime that lasts until the end of the program. If they are local variables, then their value persists when execution leaves their scope.

for (int i = 0; i < 5; ++i) {
    static int n = 0;
    printf("%d ", ++n);  // prints 1 2 3 4 5  - the value persists
}

Note that the static keyword has various meanings apart from static storage duration. On a global variable or function, it gives it internal linkage so that it's not accessible from other translation units; on a C++ class member, it means there's one instance per class rather than one per object. Also, in C++ the auto keyword no longer means automatic storage duration; it now means automatic type, deduced from the variable's initialiser.

Javascript AES encryption

If you are trying to use javascript to avoid using SSL, think again. There are many half-way measures, but only SSL provides secure communication. Javascript encryption libraries can help against a certain set of attacks, but not a true man-in-the-middle attack.

The following article explains how to attempt to create secure communication with javascript, and how to get it wrong: Use JavaScript encryption module instead of SSL/HTTPS

Note: If you are looking for SSL for google app engine on a custom domain, take a look at wwwizer.com.

Difference between objectForKey and valueForKey?

I'll try to provide a comprehensive answer here. Much of the points appear in other answers, but I found each answer incomplete, and some incorrect.

First and foremost, objectForKey: is an NSDictionary method, while valueForKey: is a KVC protocol method required of any KVC complaint class - including NSDictionary.

Furthermore, as @dreamlax wrote, documentation hints that NSDictionary implements its valueForKey: method USING its objectForKey: implementation. In other words - [NSDictionary valueForKey:] calls on [NSDictionary objectForKey:].

This implies, that valueForKey: can never be faster than objectForKey: (on the same input key) although thorough testing I've done imply about 5% to 15% difference, over billions of random access to a huge NSDictionary. In normal situations - the difference is negligible.

Next: KVC protocol only works with NSString * keys, hence valueForKey: will only accept an NSString * (or subclass) as key, whilst NSDictionary can work with other kinds of objects as keys - so that the "lower level" objectForKey: accepts any copy-able (NSCopying protocol compliant) object as key.

Last, NSDictionary's implementation of valueForKey: deviates from the standard behavior defined in KVC's documentation, and will NOT emit a NSUnknownKeyException for a key it can't find - unless this is a "special" key - one that begins with '@' - which usually means an "aggregation" function key (e.g. @"@sum, @"@avg"). Instead, it will simply return a nil when a key is not found in the NSDictionary - behaving the same as objectForKey:

Following is some test code to demonstrate and prove my notes.

- (void) dictionaryAccess {
    NSLog(@"Value for Z:%@", [@{@"X":@(10), @"Y":@(20)} valueForKey:@"Z"]); // prints "Value for Z:(null)"

    uint32_t testItemsCount = 1000000;
    // create huge dictionary of numbers
    NSMutableDictionary *d = [NSMutableDictionary dictionaryWithCapacity:testItemsCount];
    for (long i=0; i<testItemsCount; ++i) {
        // make new random key value pair:
        NSString *key = [NSString stringWithFormat:@"K_%u",arc4random_uniform(testItemsCount)];
        NSNumber *value = @(arc4random_uniform(testItemsCount));
        [d setObject:value forKey:key];
    }
    // create huge set of random keys for testing.
    NSMutableArray *keys = [NSMutableArray arrayWithCapacity:testItemsCount];
    for (long i=0; i<testItemsCount; ++i) {
        NSString *key = [NSString stringWithFormat:@"K_%u",arc4random_uniform(testItemsCount)];
        [keys addObject:key];
    }

    NSDictionary *dict = [d copy];
    NSTimeInterval vtotal = 0.0, ototal = 0.0;

    NSDate *start;
    NSTimeInterval elapsed;

    for (int i = 0; i<10; i++) {

        start = [NSDate date];
        for (NSString *key in keys) {
            id value = [dict valueForKey:key];
        }
        elapsed = [[NSDate date] timeIntervalSinceDate:start];
        vtotal+=elapsed;
        NSLog (@"reading %lu values off dictionary via valueForKey took: %10.4f seconds", keys.count, elapsed);

        start = [NSDate date];
        for (NSString *key in keys) {
            id obj = [dict objectForKey:key];
        }
        elapsed = [[NSDate date] timeIntervalSinceDate:start];
        ototal+=elapsed;
        NSLog (@"reading %lu objects off dictionary via objectForKey took: %10.4f seconds", keys.count, elapsed);
    }

    NSString *slower = (vtotal > ototal) ? @"valueForKey" : @"objectForKey";
    NSString *faster = (vtotal > ototal) ? @"objectForKey" : @"valueForKey";
    NSLog (@"%@ takes %3.1f percent longer then %@", slower, 100.0 * ABS(vtotal-ototal) / MAX(ototal,vtotal), faster);
}

Creating a constant Dictionary in C#

Why not use namespaces or classes to nest your values? It may be imperfect, but it is very clean.

public static class ParentClass
{
    // here is the "dictionary" class
    public static class FooDictionary
    {
        public const string Key1 = "somevalue";
        public const string Foobar = "fubar";
    }
}

Now you can access .ParentClass.FooDictionary.Key1, etc.

How to print a Groovy variable in Jenkins?

The following code worked for me:

echo userInput

How to select unique records by SQL

There are 4 methods you can use:

  1. DISTINCT
  2. GROUP BY
  3. Subquery
  4. Common Table Expression (CTE) with ROW_NUMBER()

Consider the following sample TABLE with test data:

/** Create test table */
CREATE TEMPORARY TABLE dupes(word text, num int, id int);

/** Add test data with duplicates */
INSERT INTO dupes(word, num, id)
VALUES ('aaa', 100, 1)
      ,('bbb', 200, 2)
      ,('ccc', 300, 3)
      ,('bbb', 400, 4)
      ,('bbb', 200, 5)     -- duplicate
      ,('ccc', 300, 6)     -- duplicate
      ,('ddd', 400, 7)
      ,('bbb', 400, 8)     -- duplicate
      ,('aaa', 100, 9)     -- duplicate
      ,('ccc', 300, 10);   -- duplicate

Option 1: SELECT DISTINCT

This is the most simple and straight forward, but also the most limited way:

SELECT DISTINCT word, num 
FROM    dupes
ORDER BY word, num;

/*
word|num|
----|---|
aaa |100|
bbb |200|
bbb |400|
ccc |300|
ddd |400|
*/

Option 2: GROUP BY

Grouping allows you to add aggregated data, like the min(id), max(id), count(*), etc:

SELECT  word, num, min(id), max(id), count(*)
FROM    dupes
GROUP BY word, num
ORDER BY word, num;

/*
word|num|min|max|count|
----|---|---|---|-----|
aaa |100|  1|  9|    2|
bbb |200|  2|  5|    2|
bbb |400|  4|  8|    2|
ccc |300|  3| 10|    3|
ddd |400|  7|  7|    1|
*/

Option 3: Subquery

Using a subquery, you can first identify the duplicate rows to ignore, and then filter them out in the outer query with the WHERE NOT IN (subquery) construct:

/** Find the higher id values of duplicates, distinct only added for clarity */
    SELECT  distinct d2.id
    FROM    dupes d1
        INNER JOIN dupes d2 ON d2.word=d1.word AND d2.num=d1.num
    WHERE d2.id > d1.id

/*
id|
--|
 5|
 6|
 8|
 9|
10|
*/

/** Use the previous query in a subquery to exclude the dupliates with higher id values */
SELECT  *
FROM    dupes
WHERE   id NOT IN (
    SELECT  d2.id
    FROM    dupes d1
        INNER JOIN dupes d2 ON d2.word=d1.word AND d2.num=d1.num
    WHERE d2.id > d1.id
)
ORDER BY word, num;

/*
word|num|id|
----|---|--|
aaa |100| 1|
bbb |200| 2|
bbb |400| 4|
ccc |300| 3|
ddd |400| 7|
*/

Option 4: Common Table Expression with ROW_NUMBER()

In the Common Table Expression (CTE), select the ROW_NUMBER(), partitioned by the group column and ordered in the desired order. Then SELECT only the records that have ROW_NUMBER() = 1:

WITH CTE AS (
    SELECT  *
           ,row_number() OVER(PARTITION BY word, num ORDER BY id) AS row_num
    FROM    dupes
)
SELECT  word, num, id 
FROM    cte
WHERE   row_num = 1
ORDER BY word, num;

/*
word|num|id|
----|---|--|
aaa |100| 1|
bbb |200| 2|
bbb |400| 4|
ccc |300| 3|
ddd |400| 7|
*/

jQuery function to get all unique elements from an array?

Paul Irish has a "Duck Punching" method (see example 2) that modifies jQuery's $.unique() method to return unique elements of any type:

(function($){
    var _old = $.unique;
    $.unique = function(arr){
        // do the default behavior only if we got an array of elements
        if (!!arr[0].nodeType){
            return _old.apply(this,arguments);
        } else {
            // reduce the array to contain no dupes via grep/inArray
            return $.grep(arr,function(v,k){
                return $.inArray(v,arr) === k;
            });
        }
    };
})(jQuery);

Test if a variable is a list or tuple

In principle, I agree with Ignacio, above, but you can also use type to check if something is a tuple or a list.

>>> a = (1,)
>>> type(a)
(type 'tuple')
>>> a = [1]
>>> type(a)
(type 'list')

Creating a border like this using :before And :after Pseudo-Elements In CSS?

#footer:after
{
   content: "";
    width: 40px;
    height: 3px;
    background-color: #529600;
    left: 0;
    position: relative;
    display: block;
    top: 10px;
}

Add Items to ListView - Android

Try this one it will work

public class Third extends ListActivity {
private ArrayAdapter<String> adapter;
private List<String> liste;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_third);
     String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
                "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
                "Linux", "OS/2" };
     liste = new ArrayList<String>();
     Collections.addAll(liste, values);
     adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, liste);
     setListAdapter(adapter);
}
 @Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
     liste.add("Nokia");
     adapter.notifyDataSetChanged();
  }
}

Array.push() and unique items

so not sure if this answers your question but the indexOf the items you are adding keep returning -1. Not to familiar with js but it appears the items do that because they are not in the array yet. I made a jsfiddle of a little modified code for you.

this.items = [];

add(1);
add(2);
add(3);

document.write("added items to array");
document.write("<br>");
function  add(item) {
        //document.write(this.items.indexOf(item));
    if(this.items.indexOf(item) <= -1) {

      this.items.push(item);
      //document.write("Hello World!");
    }
}

document.write("array is : " + this.items);

https://jsfiddle.net/jmpalmisano/Lnommkbw/2/

MySQL: ERROR 1227 (42000): Access denied - Cannot CREATE USER

First thing to do is run this:

SHOW GRANTS;

You will quickly see you were assigned the anonymous user to authenticate into mysql.

Instead of logging into mysql with

mysql

login like this:

mysql -uroot

By default, root@localhost has all rights and no password.

If you cannot login as root without a password, do the following:

Step 01) Add the two options in the mysqld section of my.ini:

[mysqld]
skip-grant-tables
skip-networking

Step 02) Restart mysql

net stop mysql
<wait 10 seconds>
net start mysql

Step 03) Connect to mysql

mysql

Step 04) Create a password from root@localhost

UPDATE mysql.user SET password=password('whateverpasswordyoulike')
WHERE user='root' AND host='localhost';
exit

Step 05) Restart mysql

net stop mysql
<wait 10 seconds>
net start mysql

Step 06) Login as root with password

mysql -u root -p

You should be good from there.

CAVEAT: Please remove anonymous users !!!

Task<> does not contain a definition for 'GetAwaiter'

GetAwaiter(), that is used by await, is implemented as an extension method in the Async CTP. I'm not sure what exactly are you using (you mention both the Async CTP and VS 2012 RC in your question), but it's possible the Async targeting pack uses the same technique.

The problem then is that extension methods don't work with dynamic. What you can do is to explicitly specify that you're working with a Task, which means the extension method will work, and then switch back to dynamic:

private async void MyButtonClick(object sender, RoutedEventArgs e)
{
    dynamic request = new SerializableDynamicObject();
    request.Operation = "test";

    Task<SerializableDynamicObject> task = Client(request);
    dynamic result = await task;

    // use result here
}

Or, since the Client() method is actually not dynamic, you could call it with SerializableDynamicObject, not dynamic, and so limit using dynamic as much as possible:

private async void MyButtonClick(object sender, RoutedEventArgs e)
{
    var request = new SerializableDynamicObject();
    dynamic dynamicRequest = request;
    dynamicRequest.Operation = "test";

    var task = Client(request);
    dynamic result = await task;

    // use result here
}

Unable to locate an executable at "/usr/bin/java/bin/java" (-1)

In MacOS Catalina, run

sudo nano ~/.bash_profile

In bash_profile, add:

export JAVA_HOME=$(/usr/libexec/java_home)
source ~/.bash_profile

Verify by running java --version

How to click a link whose href has a certain substring in Selenium?

I need to click the link who's href has substring "long" in it. How can I do this?

With the beauty of CSS selectors.

your statement would be...

driver.findElement(By.cssSelector("a[href*='long']")).click();

This means, in english,

Find me any 'a' elements, that have the href attribute, and that attribute contains 'long'

You can find a useful article about formulating your own selectors for automation effectively, as well as a list of all the other equality operators. contains, starts with, etc... You can find that at: http://ddavison.io/css/2014/02/18/effective-css-selectors.html

How to specify the actual x axis values to plot as x axis ticks in R

Hope this coding will helps you :)

plot(x,y,xaxt = 'n')

axis(side=1,at=c(1,20,30,50),labels=c("1975","1980","1985","1990"))

Check for internet connection with Swift

As of iOS 12, NWPathMonitor replaced Reachability. Use this:

import Network


struct Internet {
 
 private static let monitor = NWPathMonitor()
 
 static var active = false
 static var expensive = false
 
 /// Monitors internet connectivity changes. Updates with every change in connectivity.
 /// Updates variables for availability and if it's expensive (cellular).
 static func start() {
  guard monitor.pathUpdateHandler == nil else { return }
  
  monitor.pathUpdateHandler = { update in
   Internet.active = update.status == .satisfied ? true : false
   Internet.expensive = update.isExpensive ? true : false
  }
  
  monitor.start(queue: DispatchQueue(label: "InternetMonitor"))
 }
 
}

In use:

Internet.start()

if Internet.active {
 // do something
}
  
if Internet.expensive {
 // device is using Cellular data or WiFi hotspot
}

PostgreSQL: role is not permitted to log in

CREATE ROLE blog WITH
  LOGIN
  SUPERUSER
  INHERIT
  CREATEDB
  CREATEROLE
  REPLICATION;

COMMENT ON ROLE blog IS 'Test';

Creating multiline strings in JavaScript

This works in IE, Safari, Chrome and Firefox:

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>
<div class="crazy_idea" thorn_in_my_side='<table  border="0">
                        <tr>
                            <td ><span class="mlayouttablecellsdynamic">PACKAGE price $65.00</span></td>
                        </tr>
                    </table>'></div>
<script type="text/javascript">
    alert($(".crazy_idea").attr("thorn_in_my_side"));
</script>

What is the cleanest way to ssh and run multiple commands in Bash?

The easiest way to configure your system to use single ssh sessions by default with multiplexing.

This can be done by creating a folder for the sockets:

mkdir ~/.ssh/controlmasters

And then adding the following to your .ssh configuration:

Host *
    ControlMaster auto
    ControlPath ~/.ssh/controlmasters/%r@%h:%p.socket
    ControlMaster auto
    ControlPersist 10m

Now, you do not need to modify any of your code. This allows multiple calls to ssh and scp without creating multiple sessions, which is useful when there needs to be more interaction between your local and remote machines.

Thanks to @terminus's answer, http://www.cyberciti.biz/faq/linux-unix-osx-bsd-ssh-multiplexing-to-speed-up-ssh-connections/ and https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing.

How to decide when to use Node.js?

One more thing node provides is the ability to create multiple v8 instanes of node using node's child process( childProcess.fork() each requiring 10mb memory as per docs) on the fly, thus not affecting the main process running the server. So offloading a background job that requires huge server load becomes a child's play and we can easily kill them as and when needed.

I've been using node a lot and in most of the apps we build, require server connections at the same time thus a heavy network traffic. Frameworks like Express.js and the new Koajs (which removed callback hell) have made working on node even more easier.

How to change Git log date formats

git log -n1 --format="Last committed item in this release was by %an, `git log -n1 --format=%at | awk '{print strftime("%y%m%d%H%M",$1)}'`, message: %s (%h) [%d]"

Add column with constant value to pandas dataframe

The reason this puts NaN into a column is because df.index and the Index of your right-hand-side object are different. @zach shows the proper way to assign a new column of zeros. In general, pandas tries to do as much alignment of indices as possible. One downside is that when indices are not aligned you get NaN wherever they aren't aligned. Play around with the reindex and align methods to gain some intuition for alignment works with objects that have partially, totally, and not-aligned-all aligned indices. For example here's how DataFrame.align() works with partially aligned indices:

In [7]: from pandas import DataFrame

In [8]: from numpy.random import randint

In [9]: df = DataFrame({'a': randint(3, size=10)})

In [10]:

In [10]: df
Out[10]:
   a
0  0
1  2
2  0
3  1
4  0
5  0
6  0
7  0
8  0
9  0

In [11]: s = df.a[:5]

In [12]: dfa, sa = df.align(s, axis=0)

In [13]: dfa
Out[13]:
   a
0  0
1  2
2  0
3  1
4  0
5  0
6  0
7  0
8  0
9  0

In [14]: sa
Out[14]:
0     0
1     2
2     0
3     1
4     0
5   NaN
6   NaN
7   NaN
8   NaN
9   NaN
Name: a, dtype: float64

How to destroy a DOM element with jQuery?

Not sure if it's just me, but using .remove() doesn't seem to work if you are selecting by an id.

Ex: $("#my-element").remove();

I had to use the element's class instead, or nothing happened.

Ex: $(".my-element").remove();

"This SqlTransaction has completed; it is no longer usable."... configuration error?

In my case , I've some codes which needs to execute after committing the transaction at the same try catch block.One of the code threw an error then try block handed over the error to it's catch block which contains the transaction rollback. It will show the similar error. For example look at the code structure below :

SqlTransaction trans = null;

try{
 trans = Con.BeginTransaction();
// your codes

  trans.Commit();
//your codes having errors

}
catch(Exception ex)
{
     trans.Rollback(); //transaction roll back
    // error message
}

finally
{ 
    // connection close
}

Hope it will someone :)

MySQL - Operand should contain 1 column(s)

(SELECT users.username AS posted_by,
users.id AS posted_by_id
FROM users
WHERE users.id = posts.posted_by)

Here you using sub-query but this sub-query must return only one column. Separate it otherwise it will shows error.

How to install SignTool.exe for Windows 10

Best solution end of 2020:

Just download Windows 10 SDK from Microsoft here:
https://go.microsoft.com/fwlink/?LinkID=698771

In setup, choose only Windows App Certification App (it's only 120 MB)

enter image description here

You can find signtool.exe here:
%PROGRAMFILES(X86)%\Windows Kits\10\bin\x64

Cheers!

Java 8: Difference between two LocalDateTime in multiple units

I found the best way to do this is with ChronoUnit.

long minutes = ChronoUnit.MINUTES.between(fromDate, toDate);
long hours = ChronoUnit.HOURS.between(fromDate, toDate);

Additional documentation is here: https://docs.oracle.com/javase/tutorial/datetime/iso/period.html

How to download Visual Studio Community Edition 2015 (not 2017)

The "official" way to get the vs2015 is to go to https://my.visualstudio.com/ ; join the " Visual Studio Dev Essentials" and then search the relevant file to download https://my.visualstudio.com/Downloads?q=Visual%20Studio%202015%20with%20Update%203

How to enable file sharing for my app?

If you editing info.plist directly, below should help you, don't key in "YES" as string below:

<key>UIFileSharingEnabled</key>
<string>YES</string>

You should use this:

<key>UIFileSharingEnabled</key>
<true/>

Crontab Day of the Week syntax

    :-) Sunday    |    0  ->  Sun
                  |  
        Monday    |    1  ->  Mon
       Tuesday    |    2  ->  Tue
     Wednesday    |    3  ->  Wed
      Thursday    |    4  ->  Thu
        Friday    |    5  ->  Fri
      Saturday    |    6  ->  Sat
                  |  
    :-) Sunday    |    7  ->  Sun

As you can see above, and as said before, the numbers 0 and 7 are both assigned to Sunday. There are also the English abbreviated days of the week listed, which can also be used in the crontab.

Examples of Number or Abbreviation Use

15 09 * * 5,6,0             command
15 09 * * 5,6,7             command
15 09 * * 5-7               command
15 09 * * Fri,Sat,Sun       command

The four examples do all the same and execute a command every Friday, Saturday, and Sunday at 9.15 o'clock.

In Detail

Having two numbers 0 and 7 for Sunday can be useful for writing weekday ranges starting with 0 or ending with 7. So you can write ranges starting with Sunday or ending with it, like 0-2 or 5-7 for example (ranges must start with the lower number and must end with the higher). The abbreviations cannot be used to define a weekday range.

How to run Linux commands in Java?

The suggested solutions could be optimized using commons.io, handling the error stream, and using Exceptions. I would suggest to wrap like this for use in Java 8 or later:

public static List<String> execute(final String command) throws ExecutionFailedException, InterruptedException, IOException {
    try {
        return execute(command, 0, null, false);
    } catch (ExecutionTimeoutException e) { return null; } /* Impossible case! */
}

public static List<String> execute(final String command, final long timeout, final TimeUnit timeUnit) throws ExecutionFailedException, ExecutionTimeoutException, InterruptedException, IOException {
    return execute(command, 0, null, true);
}

public static List<String> execute(final String command, final long timeout, final TimeUnit timeUnit, boolean destroyOnTimeout) throws ExecutionFailedException, ExecutionTimeoutException, InterruptedException, IOException {
    Process process = new ProcessBuilder().command("bash", "-c", command).start();
    if(timeUnit != null) {
        if(process.waitFor(timeout, timeUnit)) {
            if(process.exitValue() == 0) {
                return IOUtils.readLines(process.getInputStream(), StandardCharsets.UTF_8);
            } else {
                throw new ExecutionFailedException("Execution failed: " + command, process.exitValue(), IOUtils.readLines(process.getInputStream(), StandardCharsets.UTF_8));
            }
        } else {
            if(destroyOnTimeout) process.destroy();
            throw new ExecutionTimeoutException("Execution timed out: " + command);
        }
    } else {
        if(process.waitFor() == 0) {
            return IOUtils.readLines(process.getInputStream(), StandardCharsets.UTF_8);
        } else {
            throw new ExecutionFailedException("Execution failed: " + command, process.exitValue(), IOUtils.readLines(process.getInputStream(), StandardCharsets.UTF_8));
        }
    }
}

public static class ExecutionFailedException extends Exception {

    private static final long serialVersionUID = 1951044996696304510L;

    private final int exitCode;
    private final List<String> errorOutput;

    public ExecutionFailedException(final String message, final int exitCode, final List<String> errorOutput) {
        super(message);
        this.exitCode = exitCode;
        this.errorOutput = errorOutput;
    }

    public int getExitCode() {
        return this.exitCode;
    }

    public List<String> getErrorOutput() {
        return this.errorOutput;
    }

}

public static class ExecutionTimeoutException extends Exception {

    private static final long serialVersionUID = 4428595769718054862L;

    public ExecutionTimeoutException(final String message) {
        super(message);
    }

}

CSS Always On Top

Assuming that your markup looks like:

<div id="header" style="position: fixed;"></div>
<div id="content" style="position: relative;"></div>

Now both elements are positioned; in which case, the element at the bottom (in source order) will cover element above it (in source order).

Add a z-index on header; 1 should be sufficient.

How to style dt and dd so they are on the same line?

I recently needed to mix inline and non-inline dt/dd pairs, by specifying the class dl-inline on <dt> elements that should be followed by inline <dd> elements.

_x000D_
_x000D_
dt.dl-inline {_x000D_
  display: inline;_x000D_
}_x000D_
dt.dl-inline:before {_x000D_
  content:"";_x000D_
  display:block;_x000D_
}_x000D_
dt.dl-inline + dd {_x000D_
  display: inline;_x000D_
  margin-left: 0.5em;_x000D_
  clear:right;_x000D_
}
_x000D_
<dl>_x000D_
    <dt>The first term.</dt>_x000D_
    <dd>Definition of the first term. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque a placerat odio viverra fusce.</dd>_x000D_
    <dt class="dl-inline">The second term.</dt>_x000D_
    <dd>Definition of the second term. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque a placerat odio viverra fusce.</dd>_x000D_
    <dt class="dl-inline">The third term.</dt>_x000D_
    <dd>Definition of the third term. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque a placerat odio viverra fusce.</dd>_x000D_
    <dt>The fourth term</dt>_x000D_
    <dd>Definition of the fourth term. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Pellentesque a placerat odio viverra fusce.</dd>_x000D_
</dl_x000D_
_x000D_
>
_x000D_
_x000D_
_x000D_

"unmappable character for encoding" warning in Java

I had the same problem, where the character index reported in the java error message was incorrect. I narrowed it down to the double quote characters just prior to the reported position being hex 094 (cancel instead of quote, but represented as a quote) instead of hex 022. As soon as I swapped for the hex 022 variant all was fine.

How do I enable Java in Microsoft Edge web browser?

You cannot open Java Applets (nor any other NPAPI plugin) in Microsoft Edge - they aren't supported and won't be added in the future.

Further you should be aware that in the next release of Google Chrome (v45 - due September 2015) NPAPI plugins will also no longer be supported.

Work-arounds

There are a couple of things that you can do:

Use Internet Explorer 11
You will find that in Windows 10 you will already have Internet Explorer 11 installed. IE 11 continues to support NPAPI (incl Java Applets). IE11 is squirrelled away (c:\program files\internet explorer\iexplore.exe). Just pin this exe to your task bar for easy access.

Use FireFox
You can also install and use a Firefox 32-bit Extended Support Release in Win10. Firefox have disabled NPAPI by default, but this can be overridden. This will only be supported until early 2018.

Update row with data from another row in the same table

Update MyTable
Set Value = (
                Select Min( T2.Value )
                From MyTable As T2
                Where T2.Id <> MyTable.Id
                    And T2.Name = MyTable.Name
                )
Where ( Value Is Null Or Value = '' )
    And Exists  (
                Select 1
                From MyTable As T3
                Where T3.Id <> MyTable.Id
                    And T3.Name = MyTable.Name
                )

How to loop through all enum values in C#?

UPDATED
Some time on, I see a comment that brings me back to my old answer, and I think I'd do it differently now. These days I'd write:

private static IEnumerable<T> GetEnumValues<T>()
{
    // Can't use type constraints on value types, so have to do check like this
    if (typeof(T).BaseType != typeof(Enum))
    {
        throw new ArgumentException("T must be of type System.Enum");
    }

    return Enum.GetValues(typeof(T)).Cast<T>();
}

Where is jarsigner?

If you can't find it, download and install Java JDK from here

Shorter syntax for casting from a List<X> to a List<Y>?

You can use List<Y>.ConvertAll<T>([Converter from Y to T]);

How can I format DateTime to web UTC format?

This code is working for me:

var datetime = new DateTime(2017, 10, 27, 14, 45, 53, 175, DateTimeKind.Local);
var text = datetime.ToString("o");
Console.WriteLine(text);
--  2017-10-27T14:45:53.1750000+03:00

// datetime from string
var newDate = DateTime.ParseExact(text, "o", null);

'System.Net.Http.HttpContent' does not contain a definition for 'ReadAsAsync' and no extension method

or if you have VS 2012 you can goto the package manager console and type Install-Package Microsoft.AspNet.WebApi.Client

This would download the latest version of the package

Count distinct values

You can use this:

select count(customer) as count, pets
from table
group by pets

Integer ASCII value to character in BASH using printf

this prints all the "printable" characters of your basic bash setup:

printf '%b\n' $(printf '\\%03o' {30..127})

 !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~

Python: finding an element in a list

assuming you want to find a value in a numpy array, I guess something like this might work:

Numpy.where(arr=="value")[0]

Ant if else condition?

You can also do this with ant contrib's if task.

<if>
    <equals arg1="${condition}" arg2="true"/>
    <then>
        <copy file="${some.dir}/file" todir="${another.dir}"/>
    </then>
    <elseif>
        <equals arg1="${condition}" arg2="false"/>
        <then>
            <copy file="${some.dir}/differentFile" todir="${another.dir}"/>
        </then>
    </elseif>
    <else>
        <echo message="Condition was neither true nor false"/>
    </else>
</if>

What is the difference between Google App Engine and Google Compute Engine?

If you're familiar with other popular services:

Google Compute Engine -> AWS EC2

Google App Engine -> Heroku or AWS Elastic Beanstalk

Google Cloud Functions -> AWS Lambda Functions

Form Submit jQuery does not work

You can use jQuery like this:

$(function() {
    $("#form").submit(function(event) {
        // do some validation, for example:
        username = $("#username").val();
        if (username.length >= 8)
            return; // valid
        event.preventDefault(); // invalidates the form
    });
});

In your HTML:

<form id="form" method="post">
    <input type="text" name="username" required id="username">
    <button type="submit">Submit</button>
</form>

References:

https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/submit_event https://api.jquery.com/submit/

Why am I getting 'Assembly '*.dll' must be strong signed in order to be marked as a prerequisite.'?

What helped me was I went onto Package Manager Solution and looked at the installed package which was causing the issue. I saw that several projects were referencing the same package but different versions. I aligned them based on my needs and it worked.

What is w3wp.exe?

An Internet Information Services (IIS) worker process is a windows process (w3wp.exe) which runs Web applications, and is responsible for handling requests sent to a Web Server for a specific application pool.

It is the worker process for IIS. Each application pool creates at least one instance of w3wp.exe and that is what actually processes requests in your application. It is not dangerous to attach to this, that is just a standard windows message.

input type=file show only button

Here is a simplified version of @ampersandre's popular solution that works in all major browsers. Asp.NET markup

<asp:TextBox runat="server" ID="FilePath" CssClass="form-control"
    style="float:left; display:inline; margin-right:5px; width:300px"
    ReadOnly="True" ClientIDMode="Static" />
<div class="inputWrapper">
    <div id="UploadFile" style="height:38px; font-size:16px; 
      text-align:center">Upload File</div>
    <div>
      <input name="FileUpload" id="FileInput" runat="server" 
             type="File" />
    </div>
  </div>
  <asp:Button ID="UploadButton" runat="server" 
    style="display:none" OnClick="UploadButton_Click" />
</div>
<asp:HiddenField ID="hdnFileName" runat="server" ClientIDMode="Static" />

JQuery Code

$(document).ready(function () {

   $('#UploadFile').click(function () {
       alert('UploadFile clicked');
       $('[id$="FileInput"]').trigger('click');
   });

   $('[id$="FileInput"]').change(function (event) {
       var target = event.target;
       var tmpFile = target.files[0].name;
       alert('FileInput changed:' + tmpFile);
       if (tmpFile.length > 0) {
          $('#hdnFileName').val(tmpFile);
       }
       $('[id$="UploadButton"]').trigger('click');
   });
});

css code

.inputWrapper {
height: 38px;
width: 102px;
overflow: hidden;
position: relative;
padding: 6px 6px;
cursor: pointer;
white-space:nowrap;
/*Using a background color, but you can use a background image to represent
 a button*/
background-color: #DEDEDE;
border: 1px solid gray;
border-radius: 4px;
-moz-user-select: none;
-ms-user-select: none;
-webkit-user-select: none;
user-select: none;
}

Uses a hidden "UploadButton" click trigger for server postback with standard . The with "Upload File" text pushes the input control out of view in the wrapper div when it overflows so there is no need to apply any styles for the "file input" control div. The $([id$="FileInput"]) selector allows section of ids with standard ASP.NET prefixes applied. The FilePath textbox value in set from server code behind from hdnFileName.Value once file is uploaded.

AngularJS $http, CORS and http authentication

For making a CORS request one must add headers to the request along with the same he needs to check of mode_header is enabled in Apache.

For enabling headers in Ubuntu:

sudo a2enmod headers

For php server to accept request from different origin use:

Header set Access-Control-Allow-Origin *
Header set Access-Control-Allow-Methods "GET, POST, PUT, DELETE"
Header always set Access-Control-Allow-Headers "x-requested-with, Content-Type, origin, authorization, accept, client-security-token"

Export specific rows from a PostgreSQL table as INSERT SQL script

This is an easy and fast way to export a table to a script with pgAdmin manually without extra installations:

  1. Right click on target table and select "Backup".
  2. Select a file path to store the backup. As Format choose "Plain".
  3. Open the tab "Dump Options #2" at the bottom and check "Use Column Inserts".
  4. Click the Backup-button.
  5. If you open the resulting file with a text reader (e.g. notepad++) you get a script to create the whole table. From there you can simply copy the generated INSERT-Statements.

This method also works with the technique of making an export_table as demonstrated in @Clodoaldo Neto's answer.

Click right on target table and choose "Backup"

Choose a destination path and change the format to "Plain"

Open the tab "Dump Options #2" at the bottom and check "Use Column Inserts"

You can copy the INSERT Statements from there.

How to get the number of threads in a Java process

There is a static method on the Thread Class that will return the number of active threads controlled by the JVM:

Thread.activeCount()

Returns the number of active threads in the current thread's thread group.

Additionally, external debuggers should list all active threads (and allow you to suspend any number of them) if you wish to monitor them in real-time.

Accessing JSON elements

Another alternative way using get method with requests:

import requests
wjdata = requests.get('url').json()
print wjdata.get('data').get('current_condition')[0].get('temp_C')

jQuery: If this HREF contains

Along with the points made by others, the $= selector is the "ends with" selector. You will want the *= (contains) selector, like so:

$('a').each(function() {
    if ($(this).is('[href*="?"')) {
        alert("Contains questionmark");
    }
});

Here's a live demo ->

As noted by Matt Ball, unless you will need to also manipulate links without a question mark (which may be the case, since you say your example is simplified), it would be less code and much faster to simply select only the links you want to begin with:

$('a[href*="?"]').each(function() {
    alert("Contains questionmark");
});

Select something that has more/less than x character

Today I was trying same in db2 and used below, in my case I had spaces at the end of varchar column data

SELECT EmployeeName FROM EmployeeTable WHERE LENGTH(TRIM(EmployeeName))> 4;

write() versus writelines() and concatenated strings

  • writelines expects an iterable of strings
  • write expects a single string.

line1 + "\n" + line2 merges those strings together into a single string before passing it to write.

Note that if you have many lines, you may want to use "\n".join(list_of_lines).

Rollback to an old Git commit in a public repo

The original poster states:

The best answer someone could give me was to use git revert X times until I reach the desired commit.

So let's say I want to revert back to a commit that's 20 commits old, I'd have to run it 20 times.

Is there an easier way to do this?

I can't use reset cause this repo is public.

It's not necessary to use git revert X times. git revert can accept a commit range as an argument, so you only need to use it once to revert a range of commits. For example, if you want to revert the last 20 commits:

git revert --no-edit HEAD~20..

The commit range HEAD~20.. is short for HEAD~20..HEAD, and means "start from the 20th parent of the HEAD commit, and revert all commits after it up to HEAD".

That will revert that last 20 commits, assuming that none of those are merge commits. If there are merge commits, then you cannot revert them all in one command, you'll need to revert them individually with

git revert -m 1 <merge-commit>

Note also that I've tested using a range with git revert using git version 1.9.0. If you're using an older version of git, using a range with git revert may or may not work.

In this case, git revert is preferred over git checkout.

Note that unlike this answer that says to use git checkout, git revert will actually remove any files that were added in any of the commits that you're reverting, which makes this the correct way to revert a range of revisions.

Documentation

Reading local text file into a JavaScript array

Using Node.js

sync mode:

var fs = require("fs");
var text = fs.readFileSync("./mytext.txt");
var textByLine = text.split("\n")

async mode:

var fs = require("fs");
fs.readFile("./mytext.txt", function(text){
    var textByLine = text.split("\n")
});

UPDATE

As of at least Node 6, readFileSync returns a Buffer, so it must first be converted to a string in order for split to work:

var text = fs.readFileSync("./mytext.txt").toString('utf-8');

Or

var text = fs.readFileSync("./mytext.txt", "utf-8");

Declaring a variable and setting its value from a SELECT query in Oracle

For storing a single row output into a variable from the select into query :

declare v_username varchare(20); SELECT username into v_username FROM users WHERE user_id = '7';

this will store the value of a single record into the variable v_username.


For storing multiple rows output into a variable from the select into query :

you have to use listagg function. listagg concatenate the resultant rows of a coloumn into a single coloumn and also to differentiate them you can use a special symbol. use the query as below SELECT listagg(username || ',' ) within group (order by username) into v_username FROM users;

new Image(), how to know if image 100% loaded or not?

Using the Promise pattern:

function getImage(url){
        return new Promise(function(resolve, reject){
            var img = new Image()
            img.onload = function(){
                resolve(url)
            }
            img.onerror = function(){
                reject(url)
            }
            img.src = url
        })
    }

And when calling the function we can handle its response or error quite neatly.

getImage('imgUrl').then(function(successUrl){
    //do stufff
}).catch(function(errorUrl){
    //do stuff
})

Difference between jQuery parent(), parents() and closest() functions

The differences between the two, though subtle, are significant:

.closest()

  • Begins with the current element
  • Travels up the DOM tree until it finds a match for the supplied selector
  • The returned jQuery object contains zero or one element

.parents()

  • Begins with the parent element
  • Travels up the DOM tree to the document's root element, adding each ancestor element to a temporary collection; it then filters that collection based on a selector if one is supplied
  • The returned jQuery object contains zero, one, or multiple elements

From jQuery docs

how to display progress while loading a url to webview in android?

You will have to over ride onPageStarted and onPageFinished callbacks

mWebView.setWebViewClient(new WebViewClient() {

        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            if (progressBar!= null && progressBar.isShowing()) {
                progressBar.dismiss();
            }
            progressBar = ProgressDialog.show(WebViewActivity.this, "Application Name", "Loading...");
        }

        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);

            return true;
        }

        public void onPageFinished(WebView view, String url) {
            if (progressBar.isShowing()) {
                progressBar.dismiss();
            }
        }

        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            alertDialog.setTitle("Error");
            alertDialog.setMessage(description);
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    return;
                }
            });
            alertDialog.show();
        }
    });

How to fix "Referenced assembly does not have a strong name" error?

There is a NuGet package named StrongNamer by Daniel Plaisted that seems to do the trick.

Is the simplest solution that I've found so far.

There are also a number of other NuGet packages to fix the strong naming problem such as Brutal.Dev.StrongNameSigner by Werner van Deventer, but I have not tested that one or any of the others.

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>

Javascript for "Add to Home Screen" on iPhone?

This is also another good Home Screen script that support iphone/ipad, Mobile Safari, Android, Blackberry touch smartphones and Playbook .

https://github.com/h5bp/mobile-boilerplate/wiki/Mobile-Bookmark-Bubble

Why do we need virtual functions in C++?

The keyword virtual tells the compiler it should not perform early binding. Instead, it should automatically install all the mechanisms necessary to perform late binding. To accomplish this, the typical compiler1 creates a single table (called the VTABLE) for each class that contains virtual functions.The compiler places the addresses of the virtual functions for that particular class in the VTABLE. In each class with virtual functions,it secretly places a pointer, called the vpointer (abbreviated as VPTR), which points to the VTABLE for that object. When you make a virtual function call through a base-class pointer the compiler quietly inserts code to fetch the VPTR and look up the function address in the VTABLE, thus calling the correct function and causing late binding to take place.

More details in this link http://cplusplusinterviews.blogspot.sg/2015/04/virtual-mechanism.html

Nth max salary in Oracle

These queries will also work:

Workaround 1)

SELECT ename, sal 
FROM Emp e1 WHERE n-1 = (SELECT COUNT(DISTINCT sal) 
                         FROM Emp e2 WHERE e2.sal > e1.sal)

Workaround 2) using row_num function.

SELECT * 
FROM ( 
   SELECT e.*, ROW_NUMBER() OVER (ORDER BY sal DESC) rn FROM Emp e 
) WHERE rn = n;

Workaround 3 ) using rownum pseudocolumn

Select MAX(SAL) 
from (
   Select * 
   from (
      Select * 
      from EMP 
      order by SAL Desc
   ) where rownum <= n
)

How to send emails from my Android application?

simple try this one

 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    buttonSend = (Button) findViewById(R.id.buttonSend);
    textTo = (EditText) findViewById(R.id.editTextTo);
    textSubject = (EditText) findViewById(R.id.editTextSubject);
    textMessage = (EditText) findViewById(R.id.editTextMessage);

    buttonSend.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            String to = textTo.getText().toString();
            String subject = textSubject.getText().toString();
            String message = textMessage.getText().toString();

            Intent email = new Intent(Intent.ACTION_SEND);
            email.putExtra(Intent.EXTRA_EMAIL, new String[] { to });
            // email.putExtra(Intent.EXTRA_CC, new String[]{ to});
            // email.putExtra(Intent.EXTRA_BCC, new String[]{to});
            email.putExtra(Intent.EXTRA_SUBJECT, subject);
            email.putExtra(Intent.EXTRA_TEXT, message);

            // need this to prompts email client only
            email.setType("message/rfc822");

            startActivity(Intent.createChooser(email, "Choose an Email client :"));

        }
    });
}

What do I need to do to get Internet Explorer 8 to accept a self signed certificate?

Here is how I got it to work in IE8:

  1. Go to the website in question, https://xxx.yyy.com, for instance,
  2. Click through until you get to the Certificate error in the browser status line.
  3. View the cert, then from the Details tab, select Copy to File.
  4. Save to the desktop as xxx.cer, for example,
  5. Start, Run, MMC.
  6. File, Add/Remove Snap-In,
  7. Select Certificates, Click Add, My User Account, then Finish, then OK,
  8. Dig down to Trust Root Certification Authorities, Certificates,
  9. Right-Click Certificate, Select All Tasks, Import,
  10. Select the Save Cert from the Desktop
  11. Select Place all Certificates in the following Store, Click Browse,
  12. Check the Box that says Show Physical Stores, Expand out Trusted Root Certification Authorities, and select Local Computer there, click OK, Complete the Import,
  13. Check the list to make sure it shows up. You will probably need to Refresh before you see it. Exit MMC,
  14. Open Browser, select Tools, Delete Browsing History
  15. Select all but Inprivate Filtering Data, complete,
  16. Go to Internet Options, Content Tab, Clear SSL State,
  17. Close browser and reopen and test.

Check if int is between two numbers

COBOL allows that (I am sure some other languages do as well). Java inherited most of it's syntax from C which doesn't allow it.

When to use Hadoop, HBase, Hive and Pig?

Use of Hive, Hbase and Pig w.r.t. my real time experience in different projects.

Hive is used mostly for:

  • Analytics purpose where you need to do analysis on history data

  • Generating business reports based on certain columns

  • Efficiently managing the data together with metadata information

  • Joining tables on certain columns which are frequently used by using bucketing concept

  • Efficient Storing and querying using partitioning concept

  • Not useful for transaction/row level operations like update, delete, etc.

Pig is mostly used for:

  • Frequent data analysis on huge data

  • Generating aggregated values/counts on huge data

  • Generating enterprise level key performance indicators very frequently

Hbase is mostly used:

  • For real time processing of data

  • For efficiently managing Complex and nested schema

  • For real time querying and faster result

  • For easy Scalability with columns

  • Useful for transaction/row level operations like update, delete, etc.

Difference between "git add -A" and "git add ."

Both git add . and git add -A will stage all new, modified and deleted files in the newer versions of Git.

The difference is that git add -A stages files in "higher, current and subdirectories" that belong to your working Git repository. But doing a git add . only stages files in the current directory and subdirectories following it (not the files lying outside, i.e., higher directories).

Here's an example:

/my-repo
  .git/
  subfolder/
    nested-file.txt
  rootfile.txt

If your current working directory is /my-repo, and you do rm rootfile.txt, then cd subfolder, followed by git add ., then it will not stage the deleted file. But doing git add -A will certainly stage this change no matter where you perform the command from.

How to use boost bind with a member function

Use the following instead:

boost::function<void (int)> f2( boost::bind( &myclass::fun2, this, _1 ) );

This forwards the first parameter passed to the function object to the function using place-holders - you have to tell Boost.Bind how to handle the parameters. With your expression it would try to interpret it as a member function taking no arguments.
See e.g. here or here for common usage patterns.

Note that VC8s cl.exe regularly crashes on Boost.Bind misuses - if in doubt use a test-case with gcc and you will probably get good hints like the template parameters Bind-internals were instantiated with if you read through the output.

struct.error: unpack requires a string argument of length 4

By default, on many platforms the short will be aligned to an offset at a multiple of 2, so there will be a padding byte added after the char.

To disable this, use: struct.unpack("=BH", data). This will use standard alignment, which doesn't add padding:

>>> struct.calcsize('=BH')
3

The = character will use native byte ordering. You can also use < or > instead of = to force little-endian or big-endian byte ordering, respectively.

Checkout Jenkins Pipeline Git SCM with credentials?

It solved for me using

checkout scm: ([
                    $class: 'GitSCM',
                    userRemoteConfigs: [[credentialsId: '******',url: ${project_url}]],
                    branches: [[name: 'refs/tags/${project_tag}']]
            ])

Sonar properties files

Do the build job on Jenkins first without Sonar configured. Then add Sonar, and run a build job again. Should fix the problem

How to solve the memory error in Python

Simplest solution: You're probably running out of virtual address space (any other form of error usually means running really slowly for a long time before you finally get a MemoryError). This is because a 32 bit application on Windows (and most OSes) is limited to 2 GB of user mode address space (Windows can be tweaked to make it 3 GB, but that's still a low cap). You've got 8 GB of RAM, but your program can't use (at least) 3/4 of it. Python has a fair amount of per-object overhead (object header, allocation alignment, etc.), odds are the strings alone are using close to a GB of RAM, and that's before you deal with the overhead of the dictionary, the rest of your program, the rest of Python, etc. If memory space fragments enough, and the dictionary needs to grow, it may not have enough contiguous space to reallocate, and you'll get a MemoryError.

Install a 64 bit version of Python (if you can, I'd recommend upgrading to Python 3 for other reasons); it will use more memory, but then, it will have access to a lot more memory space (and more physical RAM as well).

If that's not enough, consider converting to a sqlite3 database (or some other DB), so it naturally spills to disk when the data gets too large for main memory, while still having fairly efficient lookup.

How do I hide the PHP explode delimiter from submitted form results?

You could try a different approach like read the file line by line instead of dealing with all this nl2br / explode stuff.

$fh = fopen("employees.txt", "r"); if ($fh) {     while (($line = fgets($fh)) !== false) {         $line = trim($line);         echo "<option value='".$line."'>".$line."</option>";     } } else {     // error opening the file, do something } 

Also maybe just doing a trim (remove whitespace from beginning/end of string) is your issue?

And maybe people are just misunderstanding what you mean by "submitting results to a spreadsheet" -- are you doing this with code? or a copy/paste from an HTML page into a spreadsheet? Maybe you can explain that in more detail. The delimiter for which you split the lines of the file shouldn't be displaying in the output anyway unless you have unexpected output for some other reason.

How to protect Excel workbook using VBA?

  1. in your sample code you must remove the brackets, because it's not a functional assignment; also for documentary reasons I would suggest you use the := notation (see code sample below)

    1. Application.Thisworkbook refers to the book containing the VBA code, not necessarily the book containing the data, so be cautious.

Express the sheet you're working on as a sheet object and pass it, together with a logical variable to the following sub:

Sub SetProtectionMode(MySheet As Worksheet, ProtectionMode As Boolean)

    If ProtectionMode Then
        MySheet.Protect DrawingObjects:=True, Contents:=True, _
                        AllowSorting:=True, AllowFiltering:=True
    Else
        MySheet.Unprotect
    End If
End Sub

Within the .Protect method you can define what you want to allow/disallow. This code block will switch protection on/off - without password in this example, you can add it as a parameter or hardcoded within the Sub. Anyway somewhere the PW will be hardcoded. If you don't want this, just call the Protection Dialog window and let the user decide what to do:

Application.Dialogs(xlDialogProtectDocument).Show

Hope that helps

Good luck - MikeD

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

This problem is solved, in my case, by encapsulating my jQuery in:

(function($) {
//my jquery 
})(jQuery);

Jdbctemplate query for string: EmptyResultDataAccessException: Incorrect result size: expected 1, actual 0

Since getJdbcTemplate().queryForMap expects minimum size of one but when it returns null it shows EmptyResultDataAccesso fix dis when can use below logic

Map<String, String> loginMap =null;
try{
    loginMap = getJdbcTemplate().queryForMap(sql, new Object[] {CustomerLogInInfo.getCustLogInEmail()});
}
catch(EmptyResultDataAccessException ex){
    System.out.println("Exception.......");
    loginMap =null;
}
if(loginMap==null || loginMap.isEmpty()){
    return null;
}
else{
    return loginMap;
}

Unable to Connect to GitHub.com For Cloning

You are probably behind a firewall. Try cloning via https – that has a higher chance of not being blocked:

git clone https://github.com/angular/angular-phonecat.git

How to redirect docker container logs to a single file?

The easiest way that I use is this command on terminal:

docker logs elk > /home/Desktop/output.log

structure is:

docker logs <Container Name> > path/filename.log

Android ImageView Animation

Don't hard code image bounds. Just use:

RotateAnimation anim = new RotateAnimation( fromAngle, toAngle, imageView.getDrawable().getBounds().width()/2, imageView.getDrawable().getBounds().height()/2);

set option "selected" attribute from dynamic created option

You could search all the option values until it finds the correct one.

var defaultVal = "Country";
$("#select").find("option").each(function () {

    if ($(this).val() == defaultVal) {

        $(this).prop("selected", "selected");
    }
});

When does SQLiteOpenHelper onCreate() / onUpgrade() run?

Sqlite database override two methods

1) onCreate(): This method invoked only once when the application is start at first time . So it called only once

2)onUpgrade() This method called when we change the database version,then this methods gets invoked.It is used for the alter the table structure like adding new column after creating DB Schema

Show Error on the tip of the Edit Text Android

if(TextUtils.isEmpty(firstName.getText().toString()){
      firstName.setError("TEXT ERROR HERE");
}

Or you can also use TextInputLayout which has some useful method and some user friendly animation

Send email using java

Your code works, apart from setting up the connection with the SMTP server. You need a running mail (SMTP) server to send you email for you.

Here is your modified code. I commented out the parts that are not needed and changed the Session creation so it takes an Authenticator. Now just find out the SMPT_HOSTNAME, USERNAME and PASSWORD you want to use (your Internet provider usually provides them).

I always do it like this (using a remote SMTP server I know) because running a local mailserver is not that trivial under Windows (it's apparently quite easy under Linux).

import java.util.*;

import javax.mail.*;
import javax.mail.internet.*;

//import javax.activation.*;

public class SendEmail {

    private static String SMPT_HOSTNAME = "";
    private static String USERNAME = "";
    private static String PASSWORD = "";

    public static void main(String[] args) {

        // Recipient's email ID needs to be mentioned.
        String to = "[email protected]";

        // Sender's email ID needs to be mentioned
        String from = "[email protected]";

        // Assuming you are sending email from localhost
        // String host = "localhost";

        // Get system properties
        Properties properties = System.getProperties();

        // Setup mail server
        properties.setProperty("mail.smtp.host", SMPT_HOSTNAME);

        // Get the default Session object.
        // Session session = Session.getDefaultInstance(properties);

        // create a session with an Authenticator
        Session session = Session.getInstance(properties, new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(USERNAME, PASSWORD);
            }
        });

        try {
            // Create a default MimeMessage object.
            MimeMessage message = new MimeMessage(session);

            // Set From: header field of the header.
            message.setFrom(new InternetAddress(from));

            // Set To: header field of the header.
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(
                    to));

            // Set Subject: header field
            message.setSubject("This is the Subject Line!");

            // Now set the actual message
            message.setText("This is actual message");

            // Send message
            Transport.send(message);
            System.out.println("Sent message successfully....");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        }
    }
}

Getting byte array through input type = file

This is simple way to convert files to Base64 and avoid "maximum call stack size exceeded at FileReader.reader.onload" with the file has big size.

_x000D_
_x000D_
document.querySelector('#fileInput').addEventListener('change',   function () {_x000D_
_x000D_
    var reader = new FileReader();_x000D_
    var selectedFile = this.files[0];_x000D_
_x000D_
    reader.onload = function () {_x000D_
        var comma = this.result.indexOf(',');_x000D_
        var base64 = this.result.substr(comma + 1);_x000D_
        console.log(base64);_x000D_
    }_x000D_
    reader.readAsDataURL(selectedFile);_x000D_
}, false);
_x000D_
<input id="fileInput" type="file" />
_x000D_
_x000D_
_x000D_

How are booleans formatted in Strings in Python?

You may also use the Formatter class of string

print "{0} {1}".format(True, False);
print "{0:} {1:}".format(True, False);
print "{0:d} {1:d}".format(True, False);
print "{0:f} {1:f}".format(True, False);
print "{0:e} {1:e}".format(True, False);

These are the results

True False
True False
1 0
1.000000 0.000000
1.000000e+00 0.000000e+00

Some of the %-format type specifiers (%r, %i) are not available. For details see the Format Specification Mini-Language

Select entries between dates in doctrine 2


    EDIT: See the other answers for better solutions

The original newbie approaches that I offered were (opt1):

$qb->where("e.fecha > '" . $monday->format('Y-m-d') . "'");
$qb->andWhere("e.fecha < '" . $sunday->format('Y-m-d') . "'");

And (opt2):

$qb->add('where', "e.fecha between '2012-01-01' and '2012-10-10'");

That was quick and easy and got the original poster going immediately.

Hence the accepted answer.

As per comments, it is the wrong answer, but it's an easy mistake to make, so I'm leaving it here as a "what not to do!"

Why use deflate instead of gzip for text files served by Apache?

The main reason is that deflate is faster to encode than gzip and on a busy server that might make a difference. With static pages it's a different question, since they can easily be pre-compressed once.

Xcode 6 iPhone Simulator Application Support location

Here is the sh for last used simulator and application. Just run sh and copy printed text and paste and run command for show in finder.

#!/bin/zsh

lastUsedSimulatorAndApplication=`ls -td -- ~/Library/Developer/CoreSimulator/Devices/*/data/Containers/Data/Application/*/ | head -n1`

echo $lastUsedSimulatorAndApplication

Current user in Magento?

This way:

$email = Mage::getSingleton('customer/session')->getCustomer()->getEmail();
echo $email;

TypeError: 'int' object is not callable

As mentioned you might have a variable named round (of type int) in your code and removing that should get rid of the error. For Jupyter notebooks however, simply clearing a cell or deleting it might not take the variable out of scope. In such a case, you can restart your notebook to start afresh after deleting the variable.

How to find length of digits in an integer?

n = 3566002020360505
count = 0
while(n>0):
  count += 1
  n = n //10
print(f"The number of digits in the number are: {count}")

output: The number of digits in the number are: 16

FB OpenGraph og:image not pulling images (possibly https?)

After several hours of testing and trying things...

I solved this problem as simple as possible. I notice that they use "test pages" inside Facebook Developers Page that contains only the "og" tags and some text in the body tag that referals this og tags.

So what have i done?

I created a second view in my application, containing this same things they use.

And how i know is Facebook that is accessing my page so i can change the view? They have a unique User Agent: "facebookexternalhit/1.1"

What is InputStream & Output Stream? Why and when do we use them?

Stream: In laymen terms stream is data , most generic stream is binary representation of data.

Input Stream : If you are reading data from a file or any other source , stream used is input stream. In a simpler terms input stream acts as a channel to read data.

Output Stream : If you want to read and process data from a source (file etc) you first need to save the data , the mean to store data is output stream .

open the file upload dialogue box onclick the image

Also, You can write all inline, direct at html code:

<input type="file" id="imgupload">
<a href="#" onclick="$('#imgupload').trigger('click'); return false;">Upload file</a>

return false; - will be useful to decline anchor action after link was clicked.

How to open a link in new tab using angular?

In the app-routing.modules.ts file:

{
    path: 'hero/:id', component: HeroComponent
}

In the component.html file:

target="_blank" [routerLink]="['/hero', '/sachin']"

Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privileges?

I had the same problem, i.e. all privileges granted for root:

SHOW GRANTS FOR 'root'@'localhost'\G
*************************** 1. row ***************************
Grants for root@localhost: GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*[blabla]' WITH GRANT OPTION

...but still not allowed to create a table:

 create table t3(id int, txt varchar(50), primary key(id));
ERROR 1142 (42000): CREATE command denied to user 'root'@'localhost' for table 't3'

Well, it was cause by an annoying user error, i.e. I didn't select a database. After issuing USE dbname it worked fine.

Force IE8 Into IE7 Compatiblity Mode

I might have found it now. http://blog.lroot.com/articles/the-ie7-compatibility-tag-force-ie8-to-use-the-ie7-rendering-mode/

The site says adding this meta tag:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7">

or adding this to .htaccess

Header set X-UA-Compatible: IE=EmulateIE7 

Best practices with STDIN in Ruby?

Something like this perhaps?

#/usr/bin/env ruby

if $stdin.tty?
  ARGV.each do |file|
    puts "do something with this file: #{file}"
  end
else
  $stdin.each_line do |line|
    puts "do something with this line: #{line}"
  end
end

Example:

> cat input.txt | ./myprog.rb
do something with this line: this
do something with this line: is
do something with this line: a
do something with this line: test
> ./myprog.rb < input.txt 
do something with this line: this
do something with this line: is
do something with this line: a
do something with this line: test
> ./myprog.rb arg1 arg2 arg3
do something with this file: arg1
do something with this file: arg2
do something with this file: arg3

How do I find the maximum of 2 numbers?

You can use max(value, run)

The function max takes any number of arguments, or (alternatively) an iterable, and returns the maximum value.

How to get/generate the create statement for an existing hive table?

Steps to generate Create table DDLs for all the tables in the Hive database and export into text file to run later:

step 1)
create a .sh file with the below content, say hive_table_ddl.sh

#!/bin/bash
rm -f tableNames.txt
rm -f HiveTableDDL.txt
hive -e "use $1; show tables;" > tableNames.txt  
wait
cat tableNames.txt |while read LINE
   do
   hive -e "use $1;show create table $LINE;" >>HiveTableDDL.txt
   echo  -e "\n" >> HiveTableDDL.txt
   done
rm -f tableNames.txt
echo "Table DDL generated"

step 2)

Run the above shell script by passing 'db name' as paramanter

>bash hive_table_dd.sh <<databasename>>

output :

All the create table statements of your DB will be written into the HiveTableDDL.txt

When is a language considered a scripting language?

I think Mr Roberto Ierusalimschy has a very good answer or the question in 'Programming in Lua':

However, the distinguishing feature of interpreted languages is not that they are not compiled, but that any compiler is part of the language runtime and that, therefore, it is possible (and easy) to execute code generated on the fly

How to serve up a JSON response using Go?

You can do something like this in you getJsonResponse function -

jData, err := json.Marshal(Data)
if err != nil {
    // handle error
}
w.Header().Set("Content-Type", "application/json")
w.Write(jData)

Maximum call stack size exceeded on npm install

Following steps helped me to solve this issue:

  1. Stop all react strips (e.g. start build)
  2. run npm cache clean --force
  3. run npm install

How do I make a burn down chart in Excel?

No macros required. Data as below, two columns, dates don't need to be in order. Select range, convert to a Table (Ctrl+T). When data is added to the table, a chart based on the table will automatically include the added data.

Select table, insert a line chart. Right click chart, choose Select Data, click on Blank and Hidden Cells button, choose Interpolate option.

Burndown Chart of Pages Read

Using client certificate in Curl command

This is how I did it:

curl -v \
  --key ./admin-key.pem \
  --cert ./admin.pem \
  https://xxxx/api/v1/

Adding custom radio buttons in android

Simple way try this

  1. Create a new layout in drawable folder and name it custom_radiobutton (You can rename also)

     <?xml version="1.0" encoding="utf-8"?>
      <selector xmlns:android="http://schemas.android.com/apk/res/android" >
     <item android:state_checked="false" 
    android:drawable="@drawable/your_radio_off_image_name" />
     <item android:state_checked="true" 
    android:drawable="@drawable/your_radio_on_image_name" />
    </selector>
    
  2. Use this in your layout activity

    <RadioButton
     android:id="@+id/radiobutton"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:button="@drawable/custom_radiobutton"/>