Programs & Examples On #Salesforce

A Platform-as-a-Service development environment delivered on Salesforce.com - the platform is more correctly referred to as Force.com. A dedicated Salesforce Stack Exchange is available for all your Salesforce questions at http://salesforce.stackexchange.com/

Set ANDROID_HOME environment variable in mac

Open the terminal and type :

export ANDROID_HOME=/Applications/ADT/sdk

Add this to the PATH environment variable

export PATH=$PATH:$ANDROID_HOME/platform-tools

If the terminal doesn't locate the added path(s) from the .bash_profile, please run this command

source ~/.bash_profile

Hope it works to you!

Fatal error: Call to undefined function sqlsrv_connect()

i have same this because in httpd.conf in apache PHPIniDir D:/wamp/bin/php/php5.5.12 that was incorrect

Run batch file from Java code

Your code is fine, but the problem is inside the batch file.

You have to show the content of the bat file, your problem is in the paths inside the bat file.

Error TF30063: You are not authorized to access ... \DefaultCollection

When Visual Studio prompted me for Visual Studio Team Services credentials there are two options:

  1. Use a "Work or School"
  2. Use a "Personal" account

In my situation I was using a work email address, however, I had to select "Personal" in order to get connected. Selecting "Work or School" gave me the "tf30063 you are not authorized to access..." error.

For some reason my email address appears to be registered as "personal" even though everything is setup in Office 365 / Azure as a company. I believe the Microsoft account was created prior to our Silver Partnership status with Microsoft.

how can I display tooltip or item information on mouse over?

Use the title attribute while alt is important for SEO stuff.

what's the default value of char?

Default value for char is \u0000

public class DefaultValues {
char varChar;
public static void main(String...l)
 {
    DefaultValues ob =new DefaultValues();
    System.out.println(ob.varChar=='\u0000');
 }  
}

This will return true

Programmatically set image to UIImageView with Xcode 6.1/Swift

In Swift 4, if the image is returned as nil.

Click on image, on the right hand side (Utilities) -> Check Target Membership

How can I check the extension of a file?

one easy way could be:

import os

if os.path.splitext(file)[1] == ".mp3":
    # do something

os.path.splitext(file) will return a tuple with two values (the filename without extension + just the extension). The second index ([1]) will therefor give you just the extension. The cool thing is, that this way you can also access the filename pretty easily, if needed!

How to get ID of the last updated row in MySQL?

SET @uids := "";
UPDATE myf___ingtable
   SET id = id
   WHERE id < 5
  AND ( SELECT @uids := CONCAT_WS(',', CAST(id AS CHAR CHARACTER SET utf8), @uids) );
SELECT @uids;

I had to CAST the id (dunno why)... or I cannot get the @uids content (it was a blob) Btw many thanks for Pomyk answer!

Maximum filename length in NTFS (Windows XP and Windows Vista)?

Individual components of a filename (i.e. each subdirectory along the path, and the final filename) are limited to 255 characters, and the total path length is limited to approximately 32,000 characters.

However, on Windows, you can't exceed MAX_PATH value (259 characters for files, 248 for folders). See http://msdn.microsoft.com/en-us/library/aa365247.aspx for full details.

Android ListView Selector Color

TO ADD: @Christopher's answer does not work on API 7/8 (as per @Jonny's correct comment) IF you are using colours, instead of drawables. (In my testing, using drawables as per Christopher works fine)

Here is the FIX for 2.3 and below when using colours:

As per @Charles Harley, there is a bug in 2.3 and below where filling the list item with a colour causes the colour to flow out over the whole list. His fix is to define a shape drawable containing the colour you want, and to use that instead of the colour.

I suggest looking at this link if you want to just use a colour as selector, and are targeting Android 2 (or at least allow for Android 2).

How to create the pom.xml for a Java project with Eclipse

This works for me on Mac:

Right click on the project, select Configure ? Convert to Maven Project.

How to convert a datetime to string in T-SQL

SELECT CONVERT(varchar, @datetime, 103) --for UK Date format 'DD/MM/YYYY'

101 - US - MM/DD/YYYY

108 - Time - HH:MI:SS

112 - Date - YYYYMMDD

121 - ODBC - YYYY-MM-DD HH:MI:SS.FFF

20 - ODBC - YYYY-MM-DD HH:MI:SS

Instagram API: How to get all user media?

You can user pagination of Instagram PHP API: https://github.com/cosenary/Instagram-PHP-API/wiki/Using-Pagination

Something like that:

    $Instagram = new MetzWeb\Instagram\Instagram(array(
        "apiKey"      => IG_APP_KEY,
        "apiSecret"   => IG_APP_SECRET,
        "apiCallback" => IG_APP_CALLBACK
    ));
    $Instagram->setSignedHeader(true);

    $pictures = $Instagram->getUserMedia(123);
    do {

        foreach ($pictures->data as $picture_data):

            echo '<img src="'.$picture_data->images->low_resolution->url.'">';

        endforeach;

    } while ($pictures = $instagram->pagination($pictures));

jQuery AJAX form data serialize using PHP

<form method="post" name="myForm" id="myForm">

replace with above form tag remove action from form tag. and set url : "check.php" in ajax in your case first it goes to jQuery ajax then submit again the form. that's why it's creating issue.

i know i'm too late for this reply but i think it would help.

What and When to use Tuple?

The difference between a tuple and a class is that a tuple has no property names. This is almost never a good thing, and I would only use a tuple when the arguments are fairly meaningless like in an abstract math formula Eg. abstract calculus over 5,6,7 dimensions might take a tuple for the coordinates.

PHP syntax question: What does the question mark and colon mean?

This is the PHP ternary operator (also known as a conditional operator) - if first operand evaluates true, evaluate as second operand, else evaluate as third operand.

Think of it as an "if" statement you can use in expressions. Can be very useful in making concise assignments that depend on some condition, e.g.

$param = isset($_GET['param']) ? $_GET['param'] : 'default';

There's also a shorthand version of this (in PHP 5.3 onwards). You can leave out the middle operand. The operator will evaluate as the first operand if it true, and the third operand otherwise. For example:

$result = $x ?: 'default';

It is worth mentioning that the above code when using i.e. $_GET or $_POST variable will throw undefined index notice and to prevent that we need to use a longer version, with isset or a null coalescing operator which is introduced in PHP7:

$param = $_GET['param'] ?? 'default';

Java 8 lambda Void argument

Use Supplier if it takes nothing, but returns something.

Use Consumer if it takes something, but returns nothing.

Use Callable if it returns a result and might throw (most akin to Thunk in general CS terms).

Use Runnable if it does neither and cannot throw.

How can I convert a datetime object to milliseconds since epoch (unix time) in Python?

A bit of pandas code:

import pandas

def to_millis(dt):
    return int(pandas.to_datetime(dt).value / 1000000)

How to interpret "loss" and "accuracy" for a machine learning model

They are two different metrics to evaluate your model's performance usually being used in different phases.

Loss is often used in the training process to find the "best" parameter values for your model (e.g. weights in neural network). It is what you try to optimize in the training by updating weights.

Accuracy is more from an applied perspective. Once you find the optimized parameters above, you use this metrics to evaluate how accurate your model's prediction is compared to the true data.

Let us use a toy classification example. You want to predict gender from one's weight and height. You have 3 data, they are as follows:(0 stands for male, 1 stands for female)

y1 = 0, x1_w = 50kg, x2_h = 160cm;

y2 = 0, x2_w = 60kg, x2_h = 170cm;

y3 = 1, x3_w = 55kg, x3_h = 175cm;

You use a simple logistic regression model that is y = 1/(1+exp-(b1*x_w+b2*x_h))

How do you find b1 and b2? you define a loss first and use optimization method to minimize the loss in an iterative way by updating b1 and b2.

In our example, a typical loss for this binary classification problem can be: (a minus sign should be added in front of the summation sign)

We don't know what b1 and b2 should be. Let us make a random guess say b1 = 0.1 and b2 = -0.03. Then what is our loss now?

so the loss is

Then you learning algorithm (e.g. gradient descent) will find a way to update b1 and b2 to decrease the loss.

What if b1=0.1 and b2=-0.03 is the final b1 and b2 (output from gradient descent), what is the accuracy now?

Let's assume if y_hat >= 0.5, we decide our prediction is female(1). otherwise it would be 0. Therefore, our algorithm predict y1 = 1, y2 = 1 and y3 = 1. What is our accuracy? We make wrong prediction on y1 and y2 and make correct one on y3. So now our accuracy is 1/3 = 33.33%

PS: In Amir's answer, back-propagation is said to be an optimization method in NN. I think it would be treated as a way to find gradient for weights in NN. Common optimization method in NN are GradientDescent and Adam.

Using Sockets to send and receive data

    //Client

    import java.io.*;
    import java.net.*;

    public class Client {
        public static void main(String[] args) {

        String hostname = "localhost";
        int port = 6789;

        // declaration section:
        // clientSocket: our client socket
        // os: output stream
        // is: input stream

            Socket clientSocket = null;  
            DataOutputStream os = null;
            BufferedReader is = null;

        // Initialization section:
        // Try to open a socket on the given port
        // Try to open input and output streams

            try {
                clientSocket = new Socket(hostname, port);
                os = new DataOutputStream(clientSocket.getOutputStream());
                is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
            } catch (UnknownHostException e) {
                System.err.println("Don't know about host: " + hostname);
            } catch (IOException e) {
                System.err.println("Couldn't get I/O for the connection to: " + hostname);
            }

        // If everything has been initialized then we want to write some data
        // to the socket we have opened a connection to on the given port

        if (clientSocket == null || os == null || is == null) {
            System.err.println( "Something is wrong. One variable is null." );
            return;
        }

        try {
            while ( true ) {
            System.out.print( "Enter an integer (0 to stop connection, -1 to stop server): " );
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            String keyboardInput = br.readLine();
            os.writeBytes( keyboardInput + "\n" );

            int n = Integer.parseInt( keyboardInput );
            if ( n == 0 || n == -1 ) {
                break;
            }

            String responseLine = is.readLine();
            System.out.println("Server returns its square as: " + responseLine);
            }

            // clean up:
            // close the output stream
            // close the input stream
            // close the socket

            os.close();
            is.close();
            clientSocket.close();   
        } catch (UnknownHostException e) {
            System.err.println("Trying to connect to unknown host: " + e);
        } catch (IOException e) {
            System.err.println("IOException:  " + e);
        }
        }           
    }





//Server




import java.io.*;
import java.net.*;

public class Server1 {
    public static void main(String args[]) {
    int port = 6789;
    Server1 server = new Server1( port );
    server.startServer();
    }

    // declare a server socket and a client socket for the server

    ServerSocket echoServer = null;
    Socket clientSocket = null;
    int port;

    public Server1( int port ) {
    this.port = port;
    }

    public void stopServer() {
    System.out.println( "Server cleaning up." );
    System.exit(0);
    }

    public void startServer() {
    // Try to open a server socket on the given port
    // Note that we can't choose a port less than 1024 if we are not
    // privileged users (root)

        try {
        echoServer = new ServerSocket(port);
        }
        catch (IOException e) {
        System.out.println(e);
        }   

    System.out.println( "Waiting for connections. Only one connection is allowed." );

    // Create a socket object from the ServerSocket to listen and accept connections.
    // Use Server1Connection to process the connection.

    while ( true ) {
        try {
        clientSocket = echoServer.accept();
        Server1Connection oneconnection = new Server1Connection(clientSocket, this);
        oneconnection.run();
        }   
        catch (IOException e) {
        System.out.println(e);
        }
    }
    }
}

class Server1Connection {
    BufferedReader is;
    PrintStream os;
    Socket clientSocket;
    Server1 server;

    public Server1Connection(Socket clientSocket, Server1 server) {
    this.clientSocket = clientSocket;
    this.server = server;
    System.out.println( "Connection established with: " + clientSocket );
    try {
        is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
        os = new PrintStream(clientSocket.getOutputStream());
    } catch (IOException e) {
        System.out.println(e);
    }
    }

    public void run() {
        String line;
    try {
        boolean serverStop = false;

            while (true) {
                line = is.readLine();
        System.out.println( "Received " + line );
                int n = Integer.parseInt(line);
        if ( n == -1 ) {
            serverStop = true;
            break;
        }
        if ( n == 0 ) break;
                os.println("" + n*n ); 
            }

        System.out.println( "Connection closed." );
            is.close();
            os.close();
            clientSocket.close();

        if ( serverStop ) server.stopServer();
    } catch (IOException e) {
        System.out.println(e);
    }
    }
}

How to parse this string in Java?

Using String.split method will surely work as told in other answers here.

Also, StringTokenizer class can be used to to parse the String using / as the delimiter.

import java.util.StringTokenizer;
public class Test
{
    public static void main(String []args)
    {
        String s = "prefix/dir1/dir2/dir3/dir4/..";
        StringTokenizer tokenizer = new StringTokenizer(s, "/");
        String dir1 = tokenizer.nextToken();
        String dir2 = tokenizer.nextToken();
        System.out.println("Dir 1  : "+dir1);
        System.out.println("Dir 2 : " + dir2);
    }
}

Gives the output as :

Dir 1  : prefix
Dir 2 : dir1

Here you can find more about StringTokenizer.

Linq to Sql: Multiple left outer joins

Don't have access to VisualStudio (I'm on my Mac), but using the information from http://bhaidar.net/cs/archive/2007/08/01/left-outer-join-in-linq-to-sql.aspx it looks like you may be able to do something like this:

var query = from o in dc.Orders
            join v in dc.Vendors on o.VendorId equals v.Id into ov
            from x in ov.DefaultIfEmpty()
            join s in dc.Status on o.StatusId equals s.Id into os
            from y in os.DefaultIfEmpty()
            select new { o.OrderNumber, x.VendorName, y.StatusName }

How is an HTTP POST request made in node.js?

I use Restler and Needle for production purposes. They are both much more powerful than native httprequest. It is possible to request with basic authentication, special header entry or even upload/download files.

As for post/get operation, they also are much simpler to use than raw ajax calls using httprequest.

needle.post('https://my.app.com/endpoint', {foo:'bar'}, 
    function(err, resp, body){
        console.log(body);
});

How to Replace dot (.) in a string in Java

If you want to replace a simple string and you don't need the abilities of regular expressions, you can just use replace, not replaceAll.

replace replaces each matching substring but does not interpret its argument as a regular expression.

str = xpath.replace(".", "/*/");

Javascript change Div style

A simple switch statement should do the trick:

function abc() {
    var elem=document.getElementById('test'),color;
    switch(elem.style.color) {
        case('red'):
            color='black';
            break;
        case('black'):
        default:
            color='red';
    }
    elem.style.color=color;
}

SVN (Subversion) Problem "File is scheduled for addition, but is missing" - Using Versions

I just deleted the file from within VS, then from 'Repository Explorer', I copied the file to the working copy.

How can I use grep to find a word inside a folder?

grep -nr search_string search_dir

will do a RECURSIVE (meaning the directory and all it's sub-directories) search for the search_string. (as correctly answered by usta).

The reason you were not getting any anwers with your friend's suggestion of:

grep -nr string

is because no directory was specified. If you are in the directory that you want to do the search in, you have to do the following:

grep -nr string .

It is important to include the '.' character, as this tells grep to search THIS directory.

How to detect if user select cancel InputBox VBA Excel

The solution above does not work in all InputBox-Cancel cases. Most notably, it does not work if you have to InputBox a Range.

For example, try the following InputBox for defining a custom range ('sRange', type:=8, requires Set + Application.InputBox) and you will get an error upon pressing Cancel:

Sub Cancel_Handler_WRONG()
Set sRange = Application.InputBox("Input custom range", _
    "Cancel-press test", Selection.Address, Type:=8)
If StrPtr(sRange) = 0 Then  'I also tried with sRange.address and vbNullString
    MsgBox ("Cancel pressed!")
    Exit Sub
End If
    MsgBox ("Your custom range is " & sRange.Address)
End Sub

The only thing that works, in this case, is an "On Error GoTo ErrorHandler" statement before the InputBox + ErrorHandler at the end:

Sub Cancel_Handler_OK()
On Error GoTo ErrorHandler
Set sRange = Application.InputBox("Input custom range", _
    "Cancel-press test", Selection.Address, Type:=8)
MsgBox ("Your custom range is " & sRange.Address)
Exit Sub
ErrorHandler:
    MsgBox ("Cancel pressed")
End Sub

So, the question is how to detect either an error or StrPtr()=0 with an If statement?

How to install python-dateutil on Windows?

Why didn't someone tell me I was being a total noob? All I had to do was copy the dateutil directory to someplace in my Python path, and it was good to go.

HTML&CSS + Twitter Bootstrap: full page layout or height 100% - Npx

Is this what you are looking for? Here is a fiddle demo.

The layout is based on percentage, colors are for clarity. If the content column overflows, a scrollbar should appear.

body, html, .container-fluid {
  height: 100%;
}

.navbar {
  width:100%;
  background:yellow;
}

.article-tree {
  height:100%;
  width: 25%;
  float:left;
  background: pink;
}

.content-area {
  overflow: auto;
  height: 100%;
  background:orange;
}

.footer {
   background: red;
   width:100%;
   height: 20px;
}

JPA Query selecting only specific columns without using Criteria Query?

You can use something like this:

List<Object[]> list = em.createQuery("SELECT p.field1, p.field2 FROM Entity p").getResultList();

then you can iterate over it:

for (Object[] obj : list){
    System.out.println(obj[0]);
    System.out.println(obj[1]);
}

BUT if you have only one field in query, you get a list of the type not from Object[]

How to preserve request url with nginx proxy_pass

Just proxy_set_header Host $host miss port for my case. Solved by:



    location / {
     proxy_pass http://BACKENDIP/;
     include /etc/nginx/proxy.conf;
    }

and then in the proxy.conf



    proxy_redirect off;
    proxy_set_header Host $host:$server_port;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

How to clear the Entry widget after a button is pressed in Tkinter?

if none of the above is working you can use this->

idAssignedToEntryWidget.delete(first = 0, last = UpperLimitAssignedToEntryWidget)

for e.g. ->

id assigned is = en then

en.delete(first =0, last =100)

Trigger change event of dropdown

alternatively you can put onchange attribute on the dropdownlist itself, that onchange will call certain jquery function like this.

<input type="dropdownlist" onchange="jqueryFunc()">

<script type="text/javascript">
$(function(){
    jqueryFunc(){
        //something goes here
    }
});
</script>

hope this one helps you, and please note that this code is just a rough draft, not tested on any ide. thanks

C# error: Use of unassigned local variable

The compiler doesn't know that Environment.Exit() does not return. Why not just "return" from Main()?

Angular 2 'component' is not a known element

This convoluted framework is driving me nuts. Given that you defined the custom component in the the template of another component part of the SAME module, then you do not need to use exports in the module (e.g. app.module.ts). You simply need to specify the declaration in the @NgModule directive of the aforementioned module:

// app.module.ts

import { JsonInputComponent } from './json-input/json-input.component';

@NgModule({
  declarations: [
    AppComponent,
    JsonInputComponent
  ],
  ...

You do NOT need to import the JsonInputComponent (in this example) into AppComponent (in this example) to use the JsonInputComponent custom component in AppComponent template. You simply need to prefix the custom component with the module name of which both components have been defined (e.g. app):

<form [formGroup]="reactiveForm">
  <app-json-input formControlName="result"></app-json-input>
</form>

Notice app-json-input not json-input!

Demo here: https://github.com/lovefamilychildrenhappiness/AngularCustomComponentValidation

Find size of Git repository

UPDATE git 1.8.3 introduced a more efficient way to get a rough size: git count-objects -vH (see answer by @VonC)

For different ideas of "complete size" you could use:

git bundle create tmp.bundle --all
du -sh tmp.bundle

Close (but not exact:)

git gc
du -sh .git/

With the latter, you would also be counting:

  • hooks
  • config (remotes, push branches, settings (whitespace, merge, aliases, user details etc.)
  • stashes (see Can I fetch a stash from a remote repo into a local branch? also)
  • rerere cache (which can get considerable)
  • reflogs
  • backups (from filter-branch, e.g.) and various other things (intermediate state from rebase, bisect etc.)

How to set the range of y-axis for a seaborn boxplot?

It is standard matplotlib.pyplot:

...
import matplotlib.pyplot as plt
plt.ylim(10, 40)

Or simpler, as mwaskom comments below:

ax.set(ylim=(10, 40))

enter image description here

How to remove any URL within a string in Python

import re
s = '''
text1
text2
http://url.com/bla1/blah1/
text3
text4
http://url.com/bla2/blah2/
text5
text6
http://url.com/bla3/blah3/'''
g = re.findall(r'(text\d+)',s)
print ('list',g)
for i in g:
    print (i)

Out

list ['text1', 'text2', 'text3', 'text4', 'text5', 'text6']
text1
text2
text3
text4
text5
text6    ?

how to do "press enter to exit" in batch

Default interpreters from Microsoft are done in a way, that causes them exit when they reach EOF. If rake is another batch file, command interpreter switches to it and exits when rake interpretation is finished. To prevent this write:

@echo off
cls
call rake
pause

IMHO, call operator will lauch another instance of intepretator thereby preventing the current one interpreter from switching to another input file.

How to remove whitespace from a string in typescript?

The trim() method removes whitespace from both sides of a string.

To remove all the spaces from the string use .replace(/\s/g, "")

 this.maintabinfo = this.inner_view_data.replace(/\s/g, "").toLowerCase();

Fixed height and width for bootstrap carousel

To have a consistent flow of the images on different devices, you'd have to specify the width and height value for each carousel image item, for instance here in my example the image would take the full width but with a height of "400px" (you can specify your personal value instead)

<div class="item">
        <img src="image.jpg" style="width:100%; height: 400px;">
      </div>

Date ticks and rotation in matplotlib

If you prefer a non-object-oriented approach, move plt.xticks(rotation=70) to right before the two avail_plot calls, eg

plt.xticks(rotation=70)
avail_plot(axs[0], dates, s1, 'testing', 'green')
avail_plot(axs[1], dates, s1, 'testing2', 'red')

This sets the rotation property before setting up the labels. Since you have two axes here, plt.xticks gets confused after you've made the two plots. At the point when plt.xticks doesn't do anything, plt.gca() does not give you the axes you want to modify, and so plt.xticks, which acts on the current axes, is not going to work.

For an object-oriented approach not using plt.xticks, you can use

plt.setp( axs[1].xaxis.get_majorticklabels(), rotation=70 )

after the two avail_plot calls. This sets the rotation on the correct axes specifically.

how to filter out a null value from spark dataframe

Another easy way to filter out null values from multiple columns in spark dataframe. Please pay attention there is AND between columns.

df.filter(" COALESCE(col1, col2, col3, col4, col5, col6) IS NOT NULL")

If you need to filter out rows that contain any null (OR connected) please use

df.na.drop()

How can I center text (horizontally and vertically) inside a div block?

Using flexbox/CSS:

<div class="box">
    <p>&#x0D05;</p>
</div>

The CSS:

.box{
    display: flex;
    justify-content: center;
    align-items: center;
}

Taken from Quick Tip: The Simplest Way To Center Elements Vertically And Horizontally

How can I stop .gitignore from appearing in the list of untracked files?

It is quite possible that an end user wants to have Git ignore the ".gitignore" file simply because the IDE specific folders created by Eclipse are probably not the same as NetBeans or another IDE. So to keep the source code IDE antagonistic it makes life easy to have a custom git ignore that isn't shared with the entire team as individual developers might be using different IDE's.

Change string color with NSAttributedString?

You can create NSAttributedString

NSDictionary *attributes = @{ NSForegroundColorAttributeName : [UIColor redColor] };
NSAttributedString *attrStr = [[NSAttributedString alloc] initWithString:@"My Color String" attributes:attrs];

OR NSMutableAttributedString to apply custom attributes with Ranges.

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"%@%@", methodPrefix, method] attributes: @{ NSFontAttributeName : FONT_MYRIADPRO(48) }];
[attributedString addAttribute:NSFontAttributeName value:FONT_MYRIADPRO_SEMIBOLD(48) range:NSMakeRange(methodPrefix.length, method.length)];

Available Attributes: NSAttributedStringKey


UPDATE:

Swift 5.1

let message: String = greeting + someMessage
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 2.0
    
// Note: UIFont(appFontFamily:ofSize:) is extended init.
let regularAttributes: [NSAttributedString.Key : Any] = [.font : UIFont(appFontFamily: .regular, ofSize: 15)!, .paragraphStyle : paragraphStyle]
let boldAttributes = [NSAttributedString.Key.font : UIFont(appFontFamily: .semiBold, ofSize: 15)!]

let mutableString = NSMutableAttributedString(string: message, attributes: regularAttributes)
mutableString.addAttributes(boldAttributes, range: NSMakeRange(0, greeting.count))

jQuery ajax post file field

File uploads can not be done this way, no matter how you break it down. If you want to do an ajax/async upload, I would suggest looking into something like Uploadify, or Valums

Convert IQueryable<> type object to List<T> type?

Then just Select:

var list = source.Select(s=>new { ID = s.ID, Name = s.Name }).ToList();

(edit) Actually - the names could be inferred in this case, so you could use:

var list = source.Select(s=>new { s.ID, s.Name }).ToList();

which saves a few electrons...

How can I loop through a List<T> and grab each item?

Just like any other collection. With the addition of the List<T>.ForEach method.

foreach (var item in myMoney)
    Console.WriteLine("amount is {0}, and type is {1}", item.amount, item.type);

for (int i = 0; i < myMoney.Count; i++)
    Console.WriteLine("amount is {0}, and type is {1}", myMoney[i].amount, myMoney[i].type);

myMoney.ForEach(item => Console.WriteLine("amount is {0}, and type is {1}", item.amount, item.type));

How do I find the date a video (.AVI .MP4) was actually recorded?

For me the mtime (modification time) is also earlier than the create date in a lot of (most) cases since, as you say, any reorganisation modifies the create time. However, the mtime AFAIUI is an accurate reflection of when the file contents were actually changed so should be an accurate record of video capture date.

After discovering this metadata failure for movie files, I am going to be renaming my videos based on their mtime so I have this stored in a more robust way!

Splitting templated C++ classes into .hpp/.cpp files--is it possible?

Only if you #include "stack.cpp at the end of stack.hpp. I'd only recommend this approach if the implementation is relatively large, and if you rename the .cpp file to another extension, as to differentiate it from regular code.

Creating Duplicate Table From Existing Table

Use this query to create the new table with the values from existing table

CREATE TABLE New_Table_name AS SELECT * FROM Existing_table_Name; 

Now you can get all the values from existing table into newly created table.

Unable to resolve "unable to get local issuer certificate" using git on Windows with self-signed certificate

Use this command before to run composer update/install:

git config --global http.sslverify false

Why isn't this code to plot a histogram on a continuous value Pandas column working?

Here's another way to plot the data, involves turning the date_time into an index, this might help you for future slicing

#convert column to datetime
trip_data['lpep_pickup_datetime'] = pd.to_datetime(trip_data['lpep_pickup_datetime'])
#turn the datetime to an index
trip_data.index = trip_data['lpep_pickup_datetime']
#Plot
trip_data['Trip_distance'].plot(kind='hist')
plt.show()

Input Type image submit form value?

Inputs of type="image" don't send their name/value pair when used to submit the form. To me, that sounds like a bug, but that's how it is.

To get around this, you can replace the input with a button of type="submit", and put a img element inside.

Unfortunately, that causes your image to be in a ugly HTML "button". However, assuming you aren't using the standard HTML button anywhere, you can just override the stylesheet, and then everything should work as expected:

_x000D_
_x000D_
button, input[type="submit"], input[type="reset"] {_x000D_
 background: none;_x000D_
 color: inherit;_x000D_
 border: none;_x000D_
 padding: 0;_x000D_
 font: inherit;_x000D_
 cursor: pointer;_x000D_
 outline: inherit;_x000D_
}
_x000D_
<form action="/post">_x000D_
<input name="test">_x000D_
<button type="submit" name="submit_button" value="submitted">_x000D_
<img src="https://via.placeholder.com/32" alt="image">_x000D_
</button>_x000D_
</form>
_x000D_
_x000D_
_x000D_

Access item in a list of lists

50 - List1[0][0] + List[0][1] - List[0][2]

List[0] gives you the first list in the list (try out print List[0]). Then, you index into it again to get the items of that list. Think of it this way: (List1[0])[0].

jquery to validate phone number

function validatePhone(txtPhone) {
    var a = document.getElementById(txtPhone).value;
    var filter = /^((\+[1-9]{1,4}[ \-]*)|(\([0-9]{2,3}\)[ \-]*)|([0-9]{2,4})[ \-]*)*?[0-9]{3,4}?[ \-]*[0-9]{3,4}?$/;
    if (filter.test(a)) {
        return true;
    }
    else {
        return false;
    }
}

Demo http://jsfiddle.net/dishantd/JLJMW/496/

Deserializing JSON array into strongly typed .NET object

Json.NET - Documentation

http://james.newtonking.com/json/help/index.html?topic=html/SelectToken.htm

Interpretation for the author

var o = JObject.Parse(response);
var a = o.SelectToken("data").Select(jt => jt.ToObject<TheUser>()).ToList();

How to toggle a boolean?

Let's see this in action:

_x000D_
_x000D_
var b = true;_x000D_
_x000D_
console.log(b); // true_x000D_
_x000D_
b = !b;_x000D_
console.log(b); // false_x000D_
_x000D_
b = !b;_x000D_
console.log(b); // true
_x000D_
_x000D_
_x000D_

Anyways, there is no shorter way than what you currently have.

rotate image with css

Perform rotation using transform: rotate(xdeg) and also apply overflow: hidden to the parent component to avoid overlapping effect

.div-parent {
   overflow: hidden
}

.div-child {
   transform: rotate(270deg);
}

Bootstrap 3 modal vertical position center

Adding this simple css also works.

.modal-dialog {
  height: 100vh !important;
  display: flex;
}

.modal-content {
  margin: auto !important;
  height: fit-content !important;
}

Removing all line breaks and adding them after certain text

You need to that in two steps, at least.

First, click on the ¶ symbol in the toolbar: you can see if you have CRLF line endings or just LF.

Click on the Replace button, and put \r\n or \n, depending on the kind of line ending. In the Search Mode section of the dialog, check Extended radio button (interpret \n and such). Then replace all occurrences with nothing (empty string).

You end with a big line...

Next, in the same Replace dialog, put your delimiter (</Row>) for example and in the Replace With field, put the same with a line ending (</Row>\r\n). Replace All, and you are done.

time data does not match format

While the above answer is 100% helpful and correct, I'd like to add the following since only a combination of the above answer and reading through the pandas doc helped me:

2-digit / 4-digit year

It is noteworthy, that in order to parse through a 2-digit year, e.g. '90' rather than '1990', a %y is required instead of a %Y.

Infer the datetime automatically

If parsing with a pre-defined format still doesn't work for you, try using the flag infer_datetime_format=True, for example:

yields_df['Date'] = pd.to_datetime(yields_df['Date'], infer_datetime_format=True)

Be advised that this solution is slower than using a pre-defined format.

JSON Post with Customized HTTPHeader Field

if one wants to use .post() then this will set headers for all future request made with jquery

$.ajaxSetup({
    headers: {
        'Content-Type': 'application/json',
        'Accept': 'application/json'
    }
});

then make your .post() calls as normal.

Multiple returns from a function

$var1 = 0;
$var2 = 0;

function test($testvar, &$var1 , &$var2)
{
  $var1 = 1;
  $var2 = 2;
  return;
}
test("", $var1, $var2);

// var1 = 1, var2 = 2 

It's not a good way, but I think we can set two variables in a function at the same time.

how to prevent adding duplicate keys to a javascript array

function check (list){
    var foundRepeatingValue = false;
    var newList = [];
    for(i=0;i<list.length;i++){
        var thisValue = list[i];
        if(i>0){
            if(newList.indexOf(thisValue)>-1){
                foundRepeatingValue = true;
                console.log("getting repeated");
                return true;
            }
       } newList.push(thisValue);
    } return false;
}

 

var list1 = ["dse","dfg","dse"];
check(list1);

Output:

getting repeated
true

How to check if a windows form is already open, and close it if it is?

Form only once

If your goal is to diallow multiple instaces of a form, consider following ...

public class MyForm : Form
{
    private static MyForm alreadyOpened = null;

    public MyForm()
    {
        // If the form already exists, and has not been closed
        if (alreadyOpened != null && !alreadyOpened.IsDisposed)
        {
            alreadyOpened.Focus();            // Bring the old one to top
            Shown += (s, e) => this.Close();  // and destroy the new one.
            return;
        }           

        // Otherwise store this one as reference
        alreadyOpened = this;  

        // Initialization
        InitializeComponent();
    }
}

Send cookies with curl

You can use -b to specify a cookie file to read the cookies from as well.

In many situations using -c and -b to the same file is what you want:

curl -b cookies.txt -c cookies.txt http://example.com

Further

Using only -c will make curl start with no cookies but still parse and understand cookies and if redirects or multiple URLs are used, it will then use the received cookies within the single invoke before it writes them all to the output file in the end.

The -b option feeds a set of initial cookies into curl so that it knows about them at start, and it activates curl's cookie parser so that it'll parse and use incoming cookies as well.

See Also

The cookies chapter in the Everything curl book.

Dynamically create checkbox with JQuery from text input

Put a global variable to generate the ids.

<script>
    $(function(){
        // Variable to get ids for the checkboxes
        var idCounter=1;
        $("#btn1").click(function(){
            var val = $("#txtAdd").val();
            $("#divContainer").append ( "<label for='chk_" + idCounter + "'>" + val + "</label><input id='chk_" + idCounter + "' type='checkbox' value='" + val + "' />" );
            idCounter ++;
        });
    });
</script>
<div id='divContainer'></div>
<input type="text" id="txtAdd" /> 
<button id="btn1">Click</button>

AngularJS format JSON string output

Angular has a built-in filter for showing JSON

<pre>{{data | json}}</pre>

Note the use of the pre-tag to conserve whitespace and linebreaks

Demo:

_x000D_
_x000D_
angular.module('app', [])_x000D_
  .controller('Ctrl', ['$scope',_x000D_
    function($scope) {_x000D_
_x000D_
      $scope.data = {_x000D_
        a: 1,_x000D_
        b: 2,_x000D_
        c: {_x000D_
          d: "3"_x000D_
        },_x000D_
      };_x000D_
_x000D_
    }_x000D_
  ]);
_x000D_
<!DOCTYPE html>_x000D_
<html ng-app="app">_x000D_
_x000D_
  <head>_x000D_
    <script data-require="[email protected]" data-semver="1.2.15" src="//code.angularjs.org/1.2.15/angular.js"></script>_x000D_
  </head>_x000D_
_x000D_
  <body ng-controller="Ctrl">_x000D_
    <pre>{{data | json}}</pre>_x000D_
  </body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

There's also an angular.toJson method, but I haven't played around with that (Docs)

How to split data into training/testing sets using sample function

If you type:

?sample

If will launch a help menu to explain what the parameters of the sample function mean.

I am not an expert, but here is some code I have:

data <- data.frame(matrix(rnorm(400), nrow=100))
splitdata <- split(data[1:nrow(data),],sample(rep(1:4,as.integer(nrow(data)/4))))
test <- splitdata[[1]]
train <- rbind(splitdata[[1]],splitdata[[2]],splitdata[[3]])

This will give you 75% train and 25% test.

Populating a data frame in R in a loop

It is often preferable to avoid loops and use vectorized functions. If that is not possible there are two approaches:

  1. Preallocate your data.frame. This is not recommended because indexing is slow for data.frames.
  2. Use another data structure in the loop and transform into a data.frame afterwards. A list is very useful here.

Example to illustrate the general approach:

mylist <- list() #create an empty list

for (i in 1:5) {
  vec <- numeric(5) #preallocate a numeric vector
  for (j in 1:5) { #fill the vector
    vec[j] <- i^j 
  }
  mylist[[i]] <- vec #put all vectors in the list
}
df <- do.call("rbind",mylist) #combine all vectors into a matrix

In this example it is not necessary to use a list, you could preallocate a matrix. However, if you do not know how many iterations your loop will need, you should use a list.

Finally here is a vectorized alternative to the example loop:

outer(1:5,1:5,function(i,j) i^j)

As you see it's simpler and also more efficient.

Custom Listview Adapter with filter Android

you can find custom list adapter class with filterable using text change in edit text...

create custom list adapter class with implementation of Filterable:

private class CustomListAdapter extends BaseAdapter implements Filterable{

    private LayoutInflater inflater;
    private ViewHolder holder;
    private ItemFilter mFilter = new ItemFilter();

    public CustomListAdapter(List<YourCustomData> newlist) {
        filteredData = newlist;
    }

    @Override
    public int getCount() {
        return filteredData.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        holder = new ViewHolder();

        if(inflater==null)
            inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if(convertView == null){
            convertView = inflater.inflate(R.layout.row_listview_item, null);

            holder.mTextView = (TextView)convertView.findViewById(R.id.row_listview_member_tv);

            convertView.setTag(holder);
        }else{
            holder = (ViewHolder)convertView.getTag();
        }

        holder.mTextView.setText(""+filteredData.get(position).getYourdata());

        return convertView;
    }

    @Override
    public Filter getFilter() {
        return mFilter;
    }


}

class ViewHolder{
    TextView mTextView;
}

private class ItemFilter extends Filter {
    @SuppressLint("DefaultLocale")
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {

        String filterString = constraint.toString().toLowerCase();

        FilterResults results = new FilterResults();

        final List<YourCustomData> list = YourObject.getYourDataList();

        int count = list.size();
        final ArrayList<YourCustomData> nlist = new ArrayList<YourCustomData>(count);

        String filterableString ;

        for (int i = 0; i < count; i++) {
            filterableString = ""+list.get(i).getYourText();
            if (filterableString.toLowerCase().contains(filterString)) {
                YourCustomData mYourCustomData = list.get(i);
                nlist.add(mYourCustomData);
            }
        }

        results.values = nlist;
        results.count = nlist.size();

        return results;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
        filteredData = (ArrayList<YourCustomData>) results.values;
        mCustomListAdapter.notifyDataSetChanged();
    }

}

mEditTextSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(mCustomListAdapter!=null)
                mCustomListAdapter.getFilter().filter(s.toString());

        }
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }
        @Override
        public void afterTextChanged(Editable s) {
        }
    });

Add items to comboBox in WPF

Use this

string[] str = new string[] {"Foo", "Bar"};

myComboBox.ItemsSource = str;
myComboBox.SelectedIndex = 0;

OR

foreach (string s in str)
    myComboBox.Items.Add(s);

myComboBox.SelectedIndex = 0;      

PermGen elimination in JDK 8

Because the PermGen space was removed. Memory management has changed a bit.

java-8-permgen-metaspace

The imported project "C:\Microsoft.CSharp.targets" was not found

If you are to encounter the error that says Microsoft.CSharp.Core.targets not found, these are the steps I took to correct mine:

  1. Open any previous working projects folder and navigate to the link showed in the error, that is Projects/(working project name)/packages/Microsoft.Net.Compilers.1.3.2/tools/ and search for Microsoft.CSharp.Core.targets file.

  2. Copy this file and put it in the non-working project tools folder (that is, navigating to the tools folder in the non-working project as shown above)

  3. Now close your project (if it was open) and reopen it.

It should be working now.

Also, to make sure everything is working properly in your now open Visual Studio Project, Go to Tools > NuGetPackage Manager > Manage NuGet Packages For Solution. Here, you might find an error that says, CodeAnalysis.dll is being used by another application.

Again, go to the tools folder, find the specified file and delete it. Come back to Manage NuGet Packages For Solution. You will find a link that will ask you to Reload, click it and everything gets re-installed.

Your project should be working properly now.

check if "it's a number" function in Oracle

well, you could create the is_number function to call so your code works.

create or replace function is_number(param varchar2) return boolean
 as
   ret number;
 begin
    ret := to_number(param);
    return true;
 exception
    when others then return false;
 end;

EDIT: Please defer to Justin's answer. Forgot that little detail for a pure SQL call....

CSS I want a div to be on top of everything

In order for z-index to work, you'll need to give the element a position:absolute or a position:relative property. Once you do that, your links will function properly, though you may have to tweak your CSS a bit afterwards.

PHP if not statements

Your logic is slightly off. The second || should be &&:

if ((!isset($action)) || ($action != "add" && $action != "delete"))

You can see why your original line fails by trying out a sample value. Let's say $action is "delete". Here's how the condition reduces down step by step:

// $action == "delete"
if ((!isset($action)) || ($action != "add" || $action != "delete"))
if ((!true) || ($action != "add" || $action != "delete"))
if (false || ($action != "add" || $action != "delete"))
if ($action != "add" || $action != "delete")
if (true || $action != "delete")
if (true || false)
if (true)

Oops! The condition just succeeded and printed "error", but it was supposed to fail. In fact, if you think about it, no matter what the value of $action is, one of the two != tests will return true. Switch the || to && and then the second to last line becomes if (true && false), which properly reduces to if (false).

There is a way to use || and have the test work, by the way. You have to negate everything else using De Morgan's law, i.e.:

if ((!isset($action)) || !($action == "add" || $action == "delete"))

You can read that in English as "if action is not (either add or remove), then".

How to get index of an item in java.util.Set

How about add the strings to a hashtable where the value is an index:

  Hashtable<String, Integer> itemIndex = new Hashtable<>();
  itemIndex.put("First String",1);
  itemIndex.put("Second String",2);
  itemIndex.put("Third String",3);

  int indexOfThirdString = itemIndex.get("Third String");

How to write a PHP ternary operator

You could also do:

echo "yes" ?: "no" // Assuming that yes is a variable that can be false.

Instead of:

echo (true)  ? "yes" : "no";

Argument list too long error for rm, cp, mv commands

I found that for extremely large lists of files (>1e6), these answers were too slow. Here is a solution using parallel processing in python. I know, I know, this isn't linux... but nothing else here worked.

(This saved me hours)

# delete files
import os as os
import glob
import multiprocessing as mp

directory = r'your/directory'
os.chdir(directory)


files_names = [i for i in glob.glob('*.{}'.format('pdf'))]

# report errors from pool

def callback_error(result):
    print('error', result)

# delete file using system command
def delete_files(file_name):
     os.system('rm -rf ' + file_name)

pool = mp.Pool(12)  
# or use pool = mp.Pool(mp.cpu_count())


if __name__ == '__main__':
    for file_name in files_names:
        print(file_name)
        pool.apply_async(delete_files,[file_name], error_callback=callback_error)

Allow access permission to write in Program Files of Windows 7

While M$ "best practices" is to not write data into the %programfiles% folder; I sometimes do. I do not think it wise to write temporary files into such a folder; as the TEMP environment variable might e.g. point to a nice, fast, RAM drive.

I do not like to write data into %APPDATA% however. If windows gets so badly messed up that one needs to e.g. wipe it and reinstall totally, perhaps to a different drive, you might lose all your settings for nearly all your programs. I know. I've done it many times. If it is stored in %programfiles%, 1) it doesn't get lost if I e.g. have to re-install Windows on another drive, since a user can simply run the program from its directory, 2) it makes it portable, and 3) keeps programs and their data files together.

I got write access by having my installer, Inno Setup, create an empty file for my INI file, and gave it the users-modify setting in the [Files] section. I can now write it at will.

ggplot2, change title size

+ theme(plot.title = element_text(size=22))

Here is the full set of things you can change in element_text:

element_text(family = NULL, face = NULL, colour = NULL, size = NULL,
  hjust = NULL, vjust = NULL, angle = NULL, lineheight = NULL,
  color = NULL)

updating table rows in postgres using subquery

update json_source_tabcol as d
set isnullable = a.is_Nullable
from information_schema.columns as a 
where a.table_name =d.table_name 
and a.table_schema = d.table_schema 
and a.column_name = d.column_name;

How can I provide multiple conditions for data trigger in WPF?

@jasonk - if you want to have "or" then negate all conditions since (A and B) <=> ~(~A or ~B)

but if you have values other than boolean try using type converters:

<MultiDataTrigger.Conditions>
    <Condition Value="True">
        <Condition.Binding>
            <MultiBinding Converter="{StaticResource conditionConverter}">
                <Binding Path="Name" />
                <Binding Path="State" />
            </MultiBinding>
        </Condition.Binding>
        <Setter Property="Background" Value="Cyan" />
    </Condition>
</MultiDataTrigger.Conditions>

you can use the values in Convert method any way you like to produce a condition which suits you.

How to check Spark Version

Addition to @Binary Nerd

If you are using Spark, use the following to get the Spark version:

spark-submit --version

or

Login to the Cloudera Manager and goto Hosts page then run inspect hosts in cluster

Invalid date in safari

The same problem facing in Safari and it was solved by inserting this in web page

 <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=Intl.~locale.en"></script> 

Hope it will work also your case too

Thanks

Get local IP address in Node.js

Here's a simplified version in vanilla JavaScript to obtain a single IP address:

function getServerIp() {

  var os = require('os');
  var ifaces = os.networkInterfaces();
  var values = Object.keys(ifaces).map(function(name) {
    return ifaces[name];
  });
  values = [].concat.apply([], values).filter(function(val){
    return val.family == 'IPv4' && val.internal == false;
  });

  return values.length ? values[0].address : '0.0.0.0';
}

python int( ) function

Integers (int for short) are the numbers you count with 0, 1, 2, 3 ... and their negative counterparts ... -3, -2, -1 the ones without the decimal part.

So once you introduce a decimal point, your not really dealing with integers. You're dealing with rational numbers. The Python float or decimal types are what you want to represent or approximate these numbers.

You may be used to a language that automatically does this for you(Php). Python, though, has an explicit preference for forcing code to be explicit instead implicit.

What is the Eclipse shortcut for "public static void main(String args[])"?

In Eclipse, select preferences.

In preferences, look for Java/Editor/Templates.

Here you will see a list of all of them. And you can even add your own.

Inner text shadow with CSS

Building on the :before :after technique by web_designer, here is something that comes closer to your look:

First, make your text the color of the inner shadow (black-ish in the case of the OP).

Now, use an :after psuedo class to create a transparent duplicate of the original text, placed directly on top of it. Assign a regular text shadow to it with no offset. Assign the original text color to the shadow, and adjust alpha as needed.

http://dabblet.com/gist/2499892

You don't get complete control over spread, etc. of the shadow like you do in PS, but for smaller blur values it is quite passable. The shadow goes past the bounds of the text, so if you are working in an environment with a high contrast background-foreground, it will be obvious. For lower contrast items, especially ones with the same hue, it's not too noticeable. For example, I've been able to make very nice looking etched text in metal backgrounds using this technique.

Vuejs: v-model array in multiple input

If you were asking how to do it in vue2 and make options to insert and delete it, please, have a look an js fiddle

_x000D_
_x000D_
new Vue({_x000D_
  el: '#app',_x000D_
  data: {_x000D_
    finds: [] _x000D_
  },_x000D_
  methods: {_x000D_
    addFind: function () {_x000D_
      this.finds.push({ value: 'def' });_x000D_
    },_x000D_
    deleteFind: function (index) {_x000D_
      console.log(index);_x000D_
      console.log(this.finds);_x000D_
      this.finds.splice(index, 1);_x000D_
    }_x000D_
  }_x000D_
});
_x000D_
<script src="https://unpkg.com/[email protected]/dist/vue.js"></script>_x000D_
<div id="app">_x000D_
  <h1>Finds</h1>_x000D_
  <div v-for="(find, index) in finds">_x000D_
    <input v-model="find.value">_x000D_
    <button @click="deleteFind(index)">_x000D_
      delete_x000D_
    </button>_x000D_
  </div>_x000D_
  _x000D_
  <button @click="addFind">_x000D_
    New Find_x000D_
  </button>_x000D_
  _x000D_
  <pre>{{ $data }}</pre>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Show all current locks from get_lock

I found following way which can be used if you KNOW name of lock

select IS_USED_LOCK('lockname');

however i not found any info about how to list all names.

How do I add records to a DataGridView in VB.Net?

If you want to add the row to the end of the grid use the Add() method of the Rows collection...

DataGridView1.Rows.Add(New String(){Value1, Value2, Value3})

If you want to insert the row at a partiular position use the Insert() method of the Rows collection (as GWLlosa also said)...

DataGridView1.Rows.Insert(rowPosition, New String(){value1, value2, value3})

I know you mentioned you weren't doing databinding, but if you defined a strongly-typed dataset with a single datatable in your project, you could use that and get some nice strongly typed methods to do this stuff rather than rely on the grid methods...

DataSet1.DataTable.AddRow(1, "John Doe", true)

Custom method names in ASP.NET Web API

In case you're using ASP.NET 5 with ASP.NET MVC 6, most of these answers simply won't work because you'll normally let MVC create the appropriate route collection for you (using the default RESTful conventions), meaning that you won't find any Routes.MapRoute() call to edit at will.

The ConfigureServices() method invoked by the Startup.cs file will register MVC with the Dependency Injection framework built into ASP.NET 5: that way, when you call ApplicationBuilder.UseMvc() later in that class, the MVC framework will automatically add these default routes to your app. We can take a look of what happens behind the hood by looking at the UseMvc() method implementation within the framework source code:

public static IApplicationBuilder UseMvc(
    [NotNull] this IApplicationBuilder app,
    [NotNull] Action<IRouteBuilder> configureRoutes)
{
    // Verify if AddMvc was done before calling UseMvc
    // We use the MvcMarkerService to make sure if all the services were added.
    MvcServicesHelper.ThrowIfMvcNotRegistered(app.ApplicationServices);

    var routes = new RouteBuilder
    {
        DefaultHandler = new MvcRouteHandler(),
        ServiceProvider = app.ApplicationServices
    };

    configureRoutes(routes);

    // Adding the attribute route comes after running the user-code because
    // we want to respect any changes to the DefaultHandler.
    routes.Routes.Insert(0, AttributeRouting.CreateAttributeMegaRoute(
        routes.DefaultHandler,
        app.ApplicationServices));

    return app.UseRouter(routes.Build());
}

The good thing about this is that the framework now handles all the hard work, iterating through all the Controller's Actions and setting up their default routes, thus saving you some redundant work.

The bad thing is, there's little or no documentation about how you could add your own routes. Luckily enough, you can easily do that by using either a Convention-Based and/or an Attribute-Based approach (aka Attribute Routing).

Convention-Based

In your Startup.cs class, replace this:

app.UseMvc();

with this:

app.UseMvc(routes =>
            {
                // Route Sample A
                routes.MapRoute(
                    name: "RouteSampleA",
                    template: "MyOwnGet",
                    defaults: new { controller = "Items", action = "Get" }
                );
                // Route Sample B
                routes.MapRoute(
                    name: "RouteSampleB",
                    template: "MyOwnPost",
                    defaults: new { controller = "Items", action = "Post" }
                );
            });

Attribute-Based

A great thing about MVC6 is that you can also define routes on a per-controller basis by decorating either the Controller class and/or the Action methods with the appropriate RouteAttribute and/or HttpGet / HttpPost template parameters, such as the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNet.Mvc;

namespace MyNamespace.Controllers
{
    [Route("api/[controller]")]
    public class ItemsController : Controller
    {
        // GET: api/items
        [HttpGet()]
        public IEnumerable<string> Get()
        {
            return GetLatestItems();
        }

        // GET: api/items/5
        [HttpGet("{num}")]
        public IEnumerable<string> Get(int num)
        {
            return GetLatestItems(5);
        }       

        // GET: api/items/GetLatestItems
        [HttpGet("GetLatestItems")]
        public IEnumerable<string> GetLatestItems()
        {
            return GetLatestItems(5);
        }

        // GET api/items/GetLatestItems/5
        [HttpGet("GetLatestItems/{num}")]
        public IEnumerable<string> GetLatestItems(int num)
        {
            return new string[] { "test", "test2" };
        }

        // POST: /api/items/PostSomething
        [HttpPost("PostSomething")]
        public IActionResult Post([FromBody]string someData)
        {
            return Content("OK, got it!");
        }
    }
}

This controller will handle the following requests:

 [GET] api/items
 [GET] api/items/5
 [GET] api/items/GetLatestItems
 [GET] api/items/GetLatestItems/5
 [POST] api/items/PostSomething

Also notice that if you use the two approaches togheter, Attribute-based routes (when defined) would override Convention-based ones, and both of them would override the default routes defined by UseMvc().

For more info, you can also read the following post on my blog.

Using two CSS classes on one element

If you only have two items, you can do this:

.social {
    width: 330px;
    height: 75px;
    float: right;
    text-align: left;
    padding: 10px 0;
    border: none;
}

.social:first-child { 
    padding-top:0;
    border-bottom: dotted 1px #6d6d6d;
}

Manage toolbar's navigation and back button from fragment in android

You have to manage your back button pressed action on your main Activity because your main Activity is container for your fragment.

First, add your all fragment to transaction.addToBackStack(null) and now navigation back button call will be going on main activity. I hope following code will help you...

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        onBackPressed();
        }
    return super.onOptionsItemSelected(item);
}

you can also use

Fragment fragment =fragmentManager.findFragmentByTag(Constant.TAG); 
if(fragment!=null) {          
      FragmentTransaction transaction = fragmentManager.beginTransaction();
      transaction.remove(fragment).commit();
}

And to change the title according to fragment name from fragment you can use the following code:

activity.getSupportActionBar().setTitle("Keyword Report Detail");

How to Test Facebook Connect Locally

Looks like FB just changed the app dev page again and added a feature called "Server IP Whitelist".

  1. Go to your app and Select Settings -> Advanced Tab
  2. Get your public IP (google will tell you if you google "Whats My IP")
  3. Add your public IP to the Server IP Whitelist and click Save Changes at the bottom

Convert blob to base64

Another way is to use a simple wrapper around FileReader returning Observable:

  function toBase64(blob: Blob): Observable<string> {
    const reader = new FileReader();
    reader.readAsDataURL(blob);
    return fromEvent(reader, 'load')
      .pipe(map(() => (reader.result as string).split(',')[1]));
  }

Usage:

toBase64(blob).subscribe(base64 => console.log(base64));

How to convert int to date in SQL Server 2008

If your integer is timestamp in milliseconds use:

SELECT strftime("%Y-%d-%m", col_name, 'unixepoch') AS col_name

It will format milliseconds to yyyy-mm-dd string.

How can I add numbers in a Bash script?

I always forget the syntax so I come to google, but then I never find the one I'm familiar with :P. This is the cleanest to me and more true to what I'd expect in other languages.

i=0
((i++))

echo $i;

How to pop an alert message box using PHP?

Create function for alert

<?php
alert("Hello World");

function alert($msg) {
    echo "<script type='text/javascript'>alert('$msg');</script>";
}
?>

SQL Server NOLOCK and joins

I was pretty sure that you need to specify the NOLOCK for each JOIN in the query. But my experience was limited to SQL Server 2005.

When I looked up MSDN just to confirm, I couldn't find anything definite. The below statements do seem to make me think, that for 2008, your two statements above are equivalent though for 2005 it is not the case:

[SQL Server 2008 R2]

All lock hints are propagated to all the tables and views that are accessed by the query plan, including tables and views referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

[SQL Server 2005]

In SQL Server 2005, all lock hints are propagated to all the tables and views that are referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

Additionally, point to note - and this applies to both 2005 and 2008:

The table hints are ignored if the table is not accessed by the query plan. This may be caused by the optimizer choosing not to access the table at all, or because an indexed view is accessed instead. In the latter case, accessing an indexed view can be prevented by using the OPTION (EXPAND VIEWS) query hint.

What is a None value?

This is what the Python documentation has got to say about None:

The sole value of types.NoneType. None is frequently used to represent the absence of a value, as when default arguments are not passed to a function.

Changed in version 2.4: Assignments to None are illegal and raise a SyntaxError.

Note The names None and debug cannot be reassigned (assignments to them, even as an attribute name, raise SyntaxError), so they can be considered “true” constants.

  1. Let's confirm the type of None first

    print type(None)
    print None.__class__
    

    Output

    <type 'NoneType'>
    <type 'NoneType'>
    

Basically, NoneType is a data type just like int, float, etc. You can check out the list of default types available in Python in 8.15. types — Names for built-in types.

  1. And, None is an instance of NoneType class. So we might want to create instances of None ourselves. Let's try that

    print types.IntType()
    print types.NoneType()
    

    Output

    0
    TypeError: cannot create 'NoneType' instances
    

So clearly, cannot create NoneType instances. We don't have to worry about the uniqueness of the value None.

  1. Let's check how we have implemented None internally.

    print dir(None)
    

    Output

    ['__class__', '__delattr__', '__doc__', '__format__', '__getattribute__', 
     '__hash__', '__init__', '__new__', '__reduce__', '__reduce_ex__',
     '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__']
    

Except __setattr__, all others are read-only attributes. So, there is no way we can alter the attributes of None.

  1. Let's try and add new attributes to None

    setattr(types.NoneType, 'somefield', 'somevalue')
    setattr(None, 'somefield', 'somevalue')
    None.somefield = 'somevalue'
    

    Output

    TypeError: can't set attributes of built-in/extension type 'NoneType'
    AttributeError: 'NoneType' object has no attribute 'somefield'
    AttributeError: 'NoneType' object has no attribute 'somefield'
    

The above seen statements produce these error messages, respectively. It means that, we cannot create attributes dynamically on a None instance.

  1. Let us check what happens when we assign something None. As per the documentation, it should throw a SyntaxError. It means, if we assign something to None, the program will not be executed at all.

    None = 1
    

    Output

    SyntaxError: cannot assign to None
    

We have established that

  1. None is an instance of NoneType
  2. None cannot have new attributes
  3. Existing attributes of None cannot be changed.
  4. We cannot create other instances of NoneType
  5. We cannot even change the reference to None by assigning values to it.

So, as mentioned in the documentation, None can really be considered as a true constant.

Happy knowing None :)

Java/ JUnit - AssertTrue vs AssertFalse

The point is semantics. In assertTrue, you are asserting that the expression is true. If it is not, then it will display the message and the assertion will fail. In assertFalse, you are asserting that an expression evaluates to false. If it is not, then the message is displayed and the assertion fails.

assertTrue (message, value == false) == assertFalse (message, value);

These are functionally the same, but if you are expecting a value to be false then use assertFalse. If you are expecting a value to be true, then use assertTrue.

String.Format alternative in C++

The C++ way would be to use a std::stringstream object as:

std::stringstream fmt;
fmt << a << " " << b << " > " << c;

The C way would be to use sprintf.

The C way is difficult to get right since:

  • It is type unsafe
  • Requires buffer management

Of course, you may want to fall back on the C way if performance is an issue (imagine you are creating fixed-size million little stringstream objects and then throwing them away).

Get all rows from SQLite

public List<String> getAllData(String email)
{

    db = this.getReadableDatabase();
    String[] projection={email};

    List<String> list=new ArrayList<>();

    Cursor cursor = db.query(TABLE_USER, //Table to query
            null,    //columns to return
            "user_email=?",        //columns for the WHERE clause
            projection,        //The values for the WHERE clause
            null,       //group the rows
            null,       //filter by row groups
            null);
    //  cursor.moveToFirst();

    if (cursor.moveToFirst()) {
        do {

            list.add(cursor.getString(cursor.getColumnIndex("user_id")));
            list.add(cursor.getString(cursor.getColumnIndex("user_name")));
            list.add(cursor.getString(cursor.getColumnIndex("user_email")));
            list.add(cursor.getString(cursor.getColumnIndex("user_password")));
            // cursor.moveToNext();

        } while (cursor.moveToNext());
    }
    return list;
}

C++: variable 'std::ifstream ifs' has initializer but incomplete type

This seems to be answered - #include <fstream>.

The message means :-

incomplete type - the class has not been defined with a full class. The compiler has seen statements such as class ifstream; which allow it to understand that a class exists, but does not know how much memory the class takes up.

The forward declaration allows the compiler to make more sense of :-

void BindInput( ifstream & inputChannel ); 

It understands the class exists, and can send pointers and references through code without being able to create the class, see any data within the class, or call any methods of the class.

The has initializer seems a bit extraneous, but is saying that the incomplete object is being created.

segmentation fault : 11

Run your program with valgrind of linked to efence. That will tell you where the pointer is being dereferenced and most likely fix your problem if you fix all the errors they tell you about.

Undo a git stash

git stash list to list your stashed changes.

git stash show to see what n is in the below commands.

git stash apply to apply the most recent stash.

git stash apply stash@{n} to apply an older stash.

https://git-scm.com/book/en/v2/Git-Tools-Stashing-and-Cleaning

Grouping functions (tapply, by, aggregate) and the *apply family

Since I realized that (the very excellent) answers of this post lack of by and aggregate explanations. Here is my contribution.

BY

The by function, as stated in the documentation can be though, as a "wrapper" for tapply. The power of by arises when we want to compute a task that tapply can't handle. One example is this code:

ct <- tapply(iris$Sepal.Width , iris$Species , summary )
cb <- by(iris$Sepal.Width , iris$Species , summary )

 cb
iris$Species: setosa
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.300   3.200   3.400   3.428   3.675   4.400 
-------------------------------------------------------------- 
iris$Species: versicolor
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.000   2.525   2.800   2.770   3.000   3.400 
-------------------------------------------------------------- 
iris$Species: virginica
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.200   2.800   3.000   2.974   3.175   3.800 


ct
$setosa
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.300   3.200   3.400   3.428   3.675   4.400 

$versicolor
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.000   2.525   2.800   2.770   3.000   3.400 

$virginica
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  2.200   2.800   3.000   2.974   3.175   3.800 

If we print these two objects, ct and cb, we "essentially" have the same results and the only differences are in how they are shown and the different class attributes, respectively by for cb and array for ct.

As I've said, the power of by arises when we can't use tapply; the following code is one example:

 tapply(iris, iris$Species, summary )
Error in tapply(iris, iris$Species, summary) : 
  arguments must have same length

R says that arguments must have the same lengths, say "we want to calculate the summary of all variable in iris along the factor Species": but R just can't do that because it does not know how to handle.

With the by function R dispatch a specific method for data frame class and then let the summary function works even if the length of the first argument (and the type too) are different.

bywork <- by(iris, iris$Species, summary )

bywork
iris$Species: setosa
  Sepal.Length    Sepal.Width     Petal.Length    Petal.Width          Species  
 Min.   :4.300   Min.   :2.300   Min.   :1.000   Min.   :0.100   setosa    :50  
 1st Qu.:4.800   1st Qu.:3.200   1st Qu.:1.400   1st Qu.:0.200   versicolor: 0  
 Median :5.000   Median :3.400   Median :1.500   Median :0.200   virginica : 0  
 Mean   :5.006   Mean   :3.428   Mean   :1.462   Mean   :0.246                  
 3rd Qu.:5.200   3rd Qu.:3.675   3rd Qu.:1.575   3rd Qu.:0.300                  
 Max.   :5.800   Max.   :4.400   Max.   :1.900   Max.   :0.600                  
-------------------------------------------------------------- 
iris$Species: versicolor
  Sepal.Length    Sepal.Width     Petal.Length   Petal.Width          Species  
 Min.   :4.900   Min.   :2.000   Min.   :3.00   Min.   :1.000   setosa    : 0  
 1st Qu.:5.600   1st Qu.:2.525   1st Qu.:4.00   1st Qu.:1.200   versicolor:50  
 Median :5.900   Median :2.800   Median :4.35   Median :1.300   virginica : 0  
 Mean   :5.936   Mean   :2.770   Mean   :4.26   Mean   :1.326                  
 3rd Qu.:6.300   3rd Qu.:3.000   3rd Qu.:4.60   3rd Qu.:1.500                  
 Max.   :7.000   Max.   :3.400   Max.   :5.10   Max.   :1.800                  
-------------------------------------------------------------- 
iris$Species: virginica
  Sepal.Length    Sepal.Width     Petal.Length    Petal.Width          Species  
 Min.   :4.900   Min.   :2.200   Min.   :4.500   Min.   :1.400   setosa    : 0  
 1st Qu.:6.225   1st Qu.:2.800   1st Qu.:5.100   1st Qu.:1.800   versicolor: 0  
 Median :6.500   Median :3.000   Median :5.550   Median :2.000   virginica :50  
 Mean   :6.588   Mean   :2.974   Mean   :5.552   Mean   :2.026                  
 3rd Qu.:6.900   3rd Qu.:3.175   3rd Qu.:5.875   3rd Qu.:2.300                  
 Max.   :7.900   Max.   :3.800   Max.   :6.900   Max.   :2.500     

it works indeed and the result is very surprising. It is an object of class by that along Species (say, for each of them) computes the summary of each variable.

Note that if the first argument is a data frame, the dispatched function must have a method for that class of objects. For example is we use this code with the mean function we will have this code that has no sense at all:

 by(iris, iris$Species, mean)
iris$Species: setosa
[1] NA
------------------------------------------- 
iris$Species: versicolor
[1] NA
------------------------------------------- 
iris$Species: virginica
[1] NA
Warning messages:
1: In mean.default(data[x, , drop = FALSE], ...) :
  argument is not numeric or logical: returning NA
2: In mean.default(data[x, , drop = FALSE], ...) :
  argument is not numeric or logical: returning NA
3: In mean.default(data[x, , drop = FALSE], ...) :
  argument is not numeric or logical: returning NA

AGGREGATE

aggregate can be seen as another a different way of use tapply if we use it in such a way.

at <- tapply(iris$Sepal.Length , iris$Species , mean)
ag <- aggregate(iris$Sepal.Length , list(iris$Species), mean)

 at
    setosa versicolor  virginica 
     5.006      5.936      6.588 
 ag
     Group.1     x
1     setosa 5.006
2 versicolor 5.936
3  virginica 6.588

The two immediate differences are that the second argument of aggregate must be a list while tapply can (not mandatory) be a list and that the output of aggregate is a data frame while the one of tapply is an array.

The power of aggregate is that it can handle easily subsets of the data with subset argument and that it has methods for ts objects and formula as well.

These elements make aggregate easier to work with that tapply in some situations. Here are some examples (available in documentation):

ag <- aggregate(len ~ ., data = ToothGrowth, mean)

 ag
  supp dose   len
1   OJ  0.5 13.23
2   VC  0.5  7.98
3   OJ  1.0 22.70
4   VC  1.0 16.77
5   OJ  2.0 26.06
6   VC  2.0 26.14

We can achieve the same with tapply but the syntax is slightly harder and the output (in some circumstances) less readable:

att <- tapply(ToothGrowth$len, list(ToothGrowth$dose, ToothGrowth$supp), mean)

 att
       OJ    VC
0.5 13.23  7.98
1   22.70 16.77
2   26.06 26.14

There are other times when we can't use by or tapply and we have to use aggregate.

 ag1 <- aggregate(cbind(Ozone, Temp) ~ Month, data = airquality, mean)

 ag1
  Month    Ozone     Temp
1     5 23.61538 66.73077
2     6 29.44444 78.22222
3     7 59.11538 83.88462
4     8 59.96154 83.96154
5     9 31.44828 76.89655

We cannot obtain the previous result with tapply in one call but we have to calculate the mean along Month for each elements and then combine them (also note that we have to call the na.rm = TRUE, because the formula methods of the aggregate function has by default the na.action = na.omit):

ta1 <- tapply(airquality$Ozone, airquality$Month, mean, na.rm = TRUE)
ta2 <- tapply(airquality$Temp, airquality$Month, mean, na.rm = TRUE)

 cbind(ta1, ta2)
       ta1      ta2
5 23.61538 65.54839
6 29.44444 79.10000
7 59.11538 83.90323
8 59.96154 83.96774
9 31.44828 76.90000

while with by we just can't achieve that in fact the following function call returns an error (but most likely it is related to the supplied function, mean):

by(airquality[c("Ozone", "Temp")], airquality$Month, mean, na.rm = TRUE)

Other times the results are the same and the differences are just in the class (and then how it is shown/printed and not only -- example, how to subset it) object:

byagg <- by(airquality[c("Ozone", "Temp")], airquality$Month, summary)
aggagg <- aggregate(cbind(Ozone, Temp) ~ Month, data = airquality, summary)

The previous code achieve the same goal and results, at some points what tool to use is just a matter of personal tastes and needs; the previous two objects have very different needs in terms of subsetting.

How do I do word Stemming or Lemmatization?

If I may quote my answer to the question StompChicken mentioned:

The core issue here is that stemming algorithms operate on a phonetic basis with no actual understanding of the language they're working with.

As they have no understanding of the language and do not run from a dictionary of terms, they have no way of recognizing and responding appropriately to irregular cases, such as "run"/"ran".

If you need to handle irregular cases, you'll need to either choose a different approach or augment your stemming with your own custom dictionary of corrections to run after the stemmer has done its thing.

How to download image using requests

I'm going to post an answer as I don't have enough rep to make a comment, but with wget as posted by Blairg23, you can also provide an out parameter for the path.

 wget.download(url, out=path)

PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers

My case was that i was using RDS (mysql db verion 8) of AWS and was connecting my application through EC2 (my php code 5.6 was in EC2).

Here in this case since it is RDS there is no my.cnf the parameters are maintained by PARAMETER Group of AWS. Refer: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithParamGroups.html

so what i did was:

  1. Created a new Parameter group and then edited them.

  2. Searched all character-set parameters. These are blank by default. edit them individually and select utf8 from drop down list.

character_set_client, character_set_connection, character_set_database, character_set_server

  1. SAVE

And then most important, Rebooted RDS instance.

This has solved my problem and connection from php5.6 to mysql 8.x was working great.

hope this helps.

Please view this image for better understanding. enter image description here

is there a 'block until condition becomes true' function in java?

Lock-free solution(?)

I had the same issue, but I wanted a solution that didn't use locks.

Problem: I have at most one thread consuming from a queue. Multiple producer threads are constantly inserting into the queue and need to notify the consumer if it's waiting. The queue is lock-free so using locks for notification causes unnecessary blocking in producer threads. Each producer thread needs to acquire the lock before it can notify the waiting consumer. I believe I came up with a lock-free solution using LockSupport and AtomicReferenceFieldUpdater. If a lock-free barrier exists within the JDK, I couldn't find it. Both CyclicBarrier and CoundDownLatch use locks internally from what I could find.

This is my slightly abbreviated code. Just to be clear, this code will only allow one thread to wait at a time. It could be modified to allow for multiple awaiters/consumers by using some type of atomic collection to store multiple owner (a ConcurrentMap may work).

I have used this code and it seems to work. I have not tested it extensively. I suggest you read the documentation for LockSupport before use.

/* I release this code into the public domain.
 * http://unlicense.org/UNLICENSE
 */

import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.concurrent.locks.LockSupport;

/**
 * A simple barrier for awaiting a signal.
 * Only one thread at a time may await the signal.
 */
public class SignalBarrier {
    /**
     * The Thread that is currently awaiting the signal.
     * !!! Don't call this directly !!!
     */
    @SuppressWarnings("unused")
    private volatile Thread _owner;

    /** Used to update the owner atomically */
    private static final AtomicReferenceFieldUpdater<SignalBarrier, Thread> ownerAccess =
        AtomicReferenceFieldUpdater.newUpdater(SignalBarrier.class, Thread.class, "_owner");

    /** Create a new SignalBarrier without an owner. */
    public SignalBarrier() {
        _owner = null;
    }

    /**
     * Signal the owner that the barrier is ready.
     * This has no effect if the SignalBarrer is unowned.
     */
    public void signal() {
        // Remove the current owner of this barrier.
        Thread t = ownerAccess.getAndSet(this, null);

        // If the owner wasn't null, unpark it.
        if (t != null) {
            LockSupport.unpark(t);
        }
    }

    /**
     * Claim the SignalBarrier and block until signaled.
     *
     * @throws IllegalStateException If the SignalBarrier already has an owner.
     * @throws InterruptedException If the thread is interrupted while waiting.
     */
    public void await() throws InterruptedException {
        // Get the thread that would like to await the signal.
        Thread t = Thread.currentThread();

        // If a thread is attempting to await, the current owner should be null.
        if (!ownerAccess.compareAndSet(this, null, t)) {
            throw new IllegalStateException("A second thread tried to acquire a signal barrier that is already owned.");
        }

        // The current thread has taken ownership of this barrier.
        // Park the current thread until the signal. Record this
        // signal barrier as the 'blocker'.
        LockSupport.park(this);
        // If a thread has called #signal() the owner should already be null.
        // However the documentation for LockSupport.unpark makes it clear that
        // threads can wake up for absolutely no reason. Do a compare and set
        // to make sure we don't wipe out a new owner, keeping in mind that only
        // thread should be awaiting at any given moment!
        ownerAccess.compareAndSet(this, t, null);

        // Check to see if we've been unparked because of a thread interrupt.
        if (t.isInterrupted())
            throw new InterruptedException();
    }

    /**
     * Claim the SignalBarrier and block until signaled or the timeout expires.
     *
     * @throws IllegalStateException If the SignalBarrier already has an owner.
     * @throws InterruptedException If the thread is interrupted while waiting.
     *
     * @param timeout The timeout duration in nanoseconds.
     * @return The timeout minus the number of nanoseconds that passed while waiting.
     */
    public long awaitNanos(long timeout) throws InterruptedException {
        if (timeout <= 0)
            return 0;
        // Get the thread that would like to await the signal.
        Thread t = Thread.currentThread();

        // If a thread is attempting to await, the current owner should be null.
        if (!ownerAccess.compareAndSet(this, null, t)) {
            throw new IllegalStateException("A second thread tried to acquire a signal barrier is already owned.");
        }

        // The current thread owns this barrier.
        // Park the current thread until the signal. Record this
        // signal barrier as the 'blocker'.
        // Time the park.
        long start = System.nanoTime();
        LockSupport.parkNanos(this, timeout);
        ownerAccess.compareAndSet(this, t, null);
        long stop = System.nanoTime();

        // Check to see if we've been unparked because of a thread interrupt.
        if (t.isInterrupted())
            throw new InterruptedException();

        // Return the number of nanoseconds left in the timeout after what we
        // just waited.
        return Math.max(timeout - stop + start, 0L);
    }
}

To give a vague example of usage, I'll adopt james large's example:

SignalBarrier barrier = new SignalBarrier();

Consumer thread (singular, not plural!):

try {
    while(!conditionIsTrue()) {
        barrier.await();
    }
    doSomethingThatRequiresConditionToBeTrue();
} catch (InterruptedException e) {
    handleInterruption();
}

Producer thread(s):

doSomethingThatMakesConditionTrue();
barrier.signal();

How can labels/legends be added for all chart types in chart.js (chartjs.org)?

For line chart, I use the following codes.

First create custom style

.boxx{
    position: relative;
    width: 20px;
    height: 20px;
    border-radius: 3px;
}

Then add this on your line options

var lineOptions = {
            legendTemplate : '<table>'
                            +'<% for (var i=0; i<datasets.length; i++) { %>'
                            +'<tr><td><div class=\"boxx\" style=\"background-color:<%=datasets[i].fillColor %>\"></div></td>'
                            +'<% if (datasets[i].label) { %><td><%= datasets[i].label %></td><% } %></tr><tr height="5"></tr>'
                            +'<% } %>'
                            +'</table>',
            multiTooltipTemplate: "<%= datasetLabel %> - <%= value %>"

var ctx = document.getElementById("lineChart").getContext("2d");
var myNewChart = new Chart(ctx).Line(lineData, lineOptions);
document.getElementById('legendDiv').innerHTML = myNewChart.generateLegend();

Don't forget to add

<div id="legendDiv"></div>

on your html where do you want to place your legend. That's it!

How to do an Integer.parseInt() for a decimal number?

Using BigDecimal to get rounding:

String s1="0.01";
int i1 = new BigDecimal(s1).setScale(0, RoundingMode.HALF_UP).intValueExact();

String s2="0.5";
int i2 = new BigDecimal(s2).setScale(0, RoundingMode.HALF_UP).intValueExact();

Can you "compile" PHP code and upload a binary-ish file, which will just be run by the byte code interpreter?

After this question was asked, Facebook launched HipHop for PHP which is probably the best-tested PHP compiler to date (seeing as it ran one of the world’s 10 biggest websites). However, Facebook discontinued it in favour of HHVM, which is a virtual machine, not a compiler.

Beyond that, googling PHP compiler turns up a number of 3rd party solutions.

PeachPie

  • PeachPie GitHub
  • compiles PHP to .NET and .NET Core
  • can be compiled into self-contained binary file
  • runs on Mac, Linux, Windows, Windows Core, ARM, ...

Phalanger

  • GitHub (download), Wikipedia
  • compiles to .NET (CIL) looks discontinued from July 2017 and doesn't seem to support PHP 7.

phc

  • compiles to native binaries
  • not very active now (February 2014) – last version in 2011, last change in summer 2013

Roadsend PHP Compiler

bcompiler

  • PECL extension of PHP
  • experimental
  • compiles to PHP bytecode, but can wrap it in Windows binary that loads PHP interpreter (see bcompiler_write_exe_footer() manual)
  • looks discontinued now (February 2014) – last change in 2011

Project Zero

  • Wikipedia, IBM
  • incubator of changes for WebSphere sMash
  • supported by IBM
  • compiles to Java bytecode
  • looks discontinued now (February 2014) – website down, looks like big hype in 2008 and 2009

Bambalam

  • compiles to stand-alone Windows binaries
  • the binaries contain bytecode and a launcher
  • looks discontinued now (February 2014) – last change in 2006

BinaryPHP

  • compiles to C++
  • looks discontinued now (February 2014) – last change in 2003

Better way to find index of item in ArrayList?

ArrayList<String> alphabetList = new ArrayList<String>();
alphabetList.add("A"); // 0 index
alphabetList.add("B"); // 1 index
alphabetList.add("C"); // 2 index
alphabetList.add("D"); // 3 index
alphabetList.add("E"); // 4 index
alphabetList.add("F"); // 5 index
alphabetList.add("G"); // 6 index
alphabetList.add("H"); // 7 index
alphabetList.add("I"); // 8 index

int position = -1;
position = alphabetList.indexOf("H");
if (position == -1) {
    Log.e(TAG, "Object not found in List");
} else {
    Log.i(TAG, "" + position);
}

Output: List Index : 7

If you pass H it will return 7, if you pass J it will return -1 as we defined default value to -1.

Done

Programmatically add new column to DataGridView

Add new column to DataTable and use column Expression property to set your Status expression.

Here you can find good example: DataColumn.Expression Property

DataTable and DataColumn Expressions in ADO.NET - Calculated Columns

UPDATE

Code sample:

DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("colBestBefore", typeof(DateTime)));
dt.Columns.Add(new DataColumn("colStatus", typeof(string)));

dt.Columns["colStatus"].Expression = String.Format("IIF(colBestBefore < #{0}#, 'Ok','Not ok')", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));

dt.Rows.Add(DateTime.Now.AddDays(-1));
dt.Rows.Add(DateTime.Now.AddDays(1));
dt.Rows.Add(DateTime.Now.AddDays(2));
dt.Rows.Add(DateTime.Now.AddDays(-2));

demoGridView.DataSource = dt;

UPDATE #2

dt.Columns["colStatus"].Expression = String.Format("IIF(CONVERT(colBestBefore, 'System.DateTime') < #{0}#, 'Ok','Not ok')", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));

Centering FontAwesome icons vertically and horizontally

This is all you need, no wrapper needed:

.login-icon{
    display:inline-block;
    font-size: 40px;
    line-height: 50px;
    background-color:black;
    color:white;
    width: 50px;
    height: 50px;
    text-align: center;
    vertical-align: bottom;
}

http://jsfiddle.net/e2UPC/6/

Can I have multiple Xcode versions installed?

It's easy to have multiple Xcode installs.

In the installer there's a pulldown for the location... you just need to pick a new location when you're installing the beta version.

These instructions from an Apple dev tools evangelist have the full details (Apple dev username/password required): https://devforums.apple.com/message/40847#40847

Then grab yourself a custom icon for the Beta version of XCode you're using, so you can tell them apart in the dock: http://iphonedevelopment.blogspot.com/2009/03/multiple-developer-tool-installs.html

DisplayName attribute from Resources?

If you use MVC 3 and .NET 4, you can use the new Display attribute in the System.ComponentModel.DataAnnotations namespace. This attribute replaces the DisplayName attribute and provides much more functionality, including localization support.

In your case, you would use it like this:

public class MyModel
{
    [Required]
    [Display(Name = "labelForName", ResourceType = typeof(Resources.Resources))]
    public string name{ get; set; }
}

As a side note, this attribute will not work with resources inside App_GlobalResources or App_LocalResources. This has to do with the custom tool (GlobalResourceProxyGenerator) these resources use. Instead make sure your resource file is set to 'Embedded resource' and use the 'ResXFileCodeGenerator' custom tool.

(As a further side note, you shouldn't be using App_GlobalResources or App_LocalResources with MVC. You can read more about why this is the case here)

Intro to GPU programming

Check out CUDA by NVidia, IMO it's the easiest platform to do GPU programming. There are tons of cool materials to read. http://www.nvidia.com/object/cuda_home.html

Hello world would be to do any kind of calculation using GPU.

Hope that helps.

Programmatically Creating UILabel

Swift 3:

let label = UILabel(frame: CGRect(x:0,y: 0,width: 250,height: 50))
label.textAlignment = .center
label.textColor = .white
label.font = UIFont(name: "Avenir-Light", size: 15.0)
label.text = "This is a Label"
self.view.addSubview(label)

How to trap the backspace key using jQuery?

try this one :

 $('html').keyup(function(e){if(e.keyCode == 8)alert('backspace trapped')})  

How can I convert ticks to a date format?

Answers so far helped me come up with mine. I'm wary of UTC vs local time; ticks should always be UTC IMO.

public class Time
{
    public static void Timestamps()
    {
        OutputTimestamp();
        Thread.Sleep(1000);
        OutputTimestamp();
    }

    private static void OutputTimestamp()
    {
        var timestamp = DateTime.UtcNow.Ticks;
        var localTicks = DateTime.Now.Ticks;
        var localTime = new DateTime(timestamp, DateTimeKind.Utc).ToLocalTime();
        Console.Out.WriteLine("Timestamp = {0}.  Local ticks = {1}.  Local time = {2}.", timestamp, localTicks, localTime);
    }
}

Output:

Timestamp = 636988286338754530.  Local ticks = 636988034338754530.  Local time = 2019-07-15 4:03:53 PM.
Timestamp = 636988286348878736.  Local ticks = 636988034348878736.  Local time = 2019-07-15 4:03:54 PM.

Use of String.Format in JavaScript?

Your function already takes a JSON object as a parameter:

string format = "Hi {foo}".replace({
    "foo": "bar",
    "fizz": "buzz"
});

if you notice, the code:

var r = o[b];

looks at your parameter (o) and uses a key-value-pairs within it to resolve the "replace"

How to subtract X day from a Date object in Java?

c1.set(2017, 12 , 01); //Ex: 1999 jan 20    //System.out.println("Date is : " + sdf.format(c1.getTime()));
  c1.add(Calendar.MONTH, -2); // substract 1 month
  System.out.println
  ("Date minus 1 month : "
      + sdf.format(c1.getTime()));

How to change the interval time on bootstrap carousel?

You can use the options when initializing the carousel, like this:

// interval is in milliseconds. 1000 = 1 second -> so 1000 * 10 = 10 seconds
$('.carousel').carousel({
  interval: 1000 * 10
});

or you can use the interval attribute directly on the HTML tag, like this:

<div class="carousel" data-interval="10000">

The advantage of the latter approach is that you do not have to write any JS for it - while the advantage of the former is that you can compute the interval and initialize it with a variable value at run time.

How to install python3 version of package via pip on Ubuntu?

Well, on ubuntu 13.10/14.04, things are a little different.

Install

$ sudo apt-get install python3-pip

Install packages

$ sudo pip3 install packagename

NOT pip-3.3 install

SQL multiple column ordering

You can use multiple ordering on multiple condition,

ORDER BY 
     (CASE 
        WHEN @AlphabetBy = 2  THEN [Drug Name]
      END) ASC,
    CASE 
        WHEN @TopBy = 1  THEN [Rx Count]
        WHEN @TopBy = 2  THEN [Cost]
        WHEN @TopBy = 3  THEN [Revenue]
    END DESC 

How to save/restore serializable object to/from file?

You'll need to serialize to something: that is, pick binary, or xml (for default serializers) or write custom serialization code to serialize to some other text form.

Once you've picked that, your serialization will (normally) call a Stream that is writing to some kind of file.

So, with your code, if I were using XML Serialization:

var path = @"C:\Test\myserializationtest.xml";
using(FileStream fs = new FileStream(path, FileMode.Create))
{
    XmlSerializer xSer = new XmlSerializer(typeof(SomeClass));

    xSer.Serialize(fs, serializableObject);
}

Then, to deserialize:

using(FileStream fs = new FileStream(path, FileMode.Open)) //double check that...
{
    XmlSerializer _xSer = new XmlSerializer(typeof(SomeClass));

    var myObject = _xSer.Deserialize(fs);
}

NOTE: This code hasn't been compiled, let alone run- there may be some errors. Also, this assumes completely out-of-the-box serialization/deserialization. If you need custom behavior, you'll need to do additional work.

How to connect to SQL Server from another computer?

I'll edit my previous answer based on further info supplied. You can clearely ping the remote computer as you can use terminal services.

I've a feeling that port 1433 is being blocked by a firewall, hence your trouble. See TCP Ports Needed for Communication to SQL Server Through a Firewall by Microsoft.

Try using this application to ping your servers ip address and port 1433.

tcping your.server.ip.address 1433

And see if you get a "Port is open" response from tcping.

Ok, next to try is to check SQL Server. RDP onto the SQL Server computer. Start SSMS. Connect to the database. In object explorer (usually docked on the left) right click on the server and click properties.

alt text http://www.hicrest.net/server_prop_menu.jpg

Goto the Connections settings and make sure "Allow remote connections to this server" is ticket.

alt text http://www.hicrest.net/server_properties.jpg

Is gcc's __attribute__((packed)) / #pragma pack unsafe?

As ams said above, don't take a pointer to a member of a struct that's packed. This is simply playing with fire. When you say __attribute__((__packed__)) or #pragma pack(1), what you're really saying is "Hey gcc, I really know what I'm doing." When it turns out that you do not, you can't rightly blame the compiler.

Perhaps we can blame the compiler for it's complacency though. While gcc does have a -Wcast-align option, it isn't enabled by default nor with -Wall or -Wextra. This is apparently due to gcc developers considering this type of code to be a brain-dead "abomination" unworthy of addressing -- understandable disdain, but it doesn't help when an inexperienced programmer bumbles into it.

Consider the following:

struct  __attribute__((__packed__)) my_struct {
    char c;
    int i;
};

struct my_struct a = {'a', 123};
struct my_struct *b = &a;
int c = a.i;
int d = b->i;
int *e __attribute__((aligned(1))) = &a.i;
int *f = &a.i;

Here, the type of a is a packed struct (as defined above). Similarly, b is a pointer to a packed struct. The type of of the expression a.i is (basically) an int l-value with 1 byte alignment. c and d are both normal ints. When reading a.i, the compiler generates code for unaligned access. When you read b->i, b's type still knows it's packed, so no problem their either. e is a pointer to a one-byte-aligned int, so the compiler knows how to dereference that correctly as well. But when you make the assignment f = &a.i, you are storing the value of an unaligned int pointer in an aligned int pointer variable -- that's where you went wrong. And I agree, gcc should have this warning enabled by default (not even in -Wall or -Wextra).

How to test if a string is JSON or not?

In addition to previous answers, in case of you need to validate a JSON format like "{}", you can use the following code:

const validateJSON = (str) => {
  try {
    const json = JSON.parse(str);
    if (Object.prototype.toString.call(json).slice(8,-1) !== 'Object') {
      return false;
    }
  } catch (e) {
    return false;
  }
  return true;
}

Examples of usage:

validateJSON('{}')
true
validateJSON('[]')
false
validateJSON('')
false
validateJSON('2134')
false
validateJSON('{ "Id": 1, "Name": "Coke" }')
true

What is the recommended way to delete a large number of items from DynamoDB?

We don't have option to truncate dynamo tables. we have to drop the table and create again . DynamoDB Charges are based on ReadCapacityUnits & WriteCapacityUnits . If we delete all items using BatchWriteItem function, it will use WriteCapacityUnits.So better to delete specific records or delete the table and start again .

Apache 2.4 - Request exceeded the limit of 10 internal redirects due to probable configuration error

This problem can be caused by requests for certain files that don't exist. For example, requests for files in wp-content/uploads/ where the file does not exist.

If this is the situation you're seeing, you can solve the problem by going to .htaccess and changing this line:

RewriteRule ^(wp-(content|admin|includes).*) $1 [L]

to:

RewriteRule ^(wp-(content|admin|includes).*) - [L]

The underlying issue is that the rule above triggers a rewrite to the exact same url with a slash in front and because there was a rewrite, the newly rewritten request goes back through the rules again and the same rule is triggered. By changing that line's "$1" to "-", no rewrite happens and so the rewriting process does not start over again with the same URL.

It's possible that there's a difference in how apache 2.2 and 2.4 handle this situation of only-difference-is-a-slash-in-front and that's why the default rules provided by WordPress aren't working perfectly.

Make javascript alert Yes/No Instead of Ok/Cancel

You can use jQuery UI Dialog.

These libraries create HTML elements that look and behave like a dialog box, allowing you to put anything you want (including form elements or video) in the dialog.

Relational Database Design Patterns?

AskTom is probably the single most helpful resource on best practices on Oracle DBs. (I usually just type "asktom" as the first word of a google query on a particular topic)

I don't think it's really appropriate to speak of design patterns with relational databases. Relational databases are already the application of a "design pattern" to a problem (the problem being "how to represent, store and work with data while maintaining its integrity", and the design being the relational model). Other approches (generally considered obsolete) are the Navigational and Hierarchical models (and I'm nure many others exist).

Having said that, you might consider "Data Warehousing" as a somewhat separate "pattern" or approach in database design. In particular, you might be interested in reading about the Star schema.

How to choose an AWS profile when using boto3 to connect to CloudFront

Just add profile to session configuration before client call. boto3.session.Session(profile_name='YOUR_PROFILE_NAME').client('cloudwatch')

How to add a button to UINavigationBar?

Adding custom button to navigation bar ( with image for buttonItem and specifying action method (void)openView{} and).

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 32, 32);
[button setImage:[UIImage imageNamed:@"settings_b.png"] forState:UIControlStateNormal];
[button addTarget:self action:@selector(openView) forControlEvents:UIControlEventTouchUpInside];

UIBarButtonItem *barButton=[[UIBarButtonItem alloc] init];
[barButton setCustomView:button];
self.navigationItem.rightBarButtonItem=barButton;

[button release];
[barButton release];

Custom Date/Time formatting in SQL Server

If dt is your datetime column, then

For 1:

SUBSTRING(CONVERT(varchar, dt, 13), 1, 2)
    + UPPER(SUBSTRING(CONVERT(varchar, dt, 13), 4, 3))

For 2:

SUBSTRING(CONVERT(varchar, dt, 100), 13, 2)
    + SUBSTRING(CONVERT(varchar, dt, 100), 16, 3)

How to fix apt-get: command not found on AWS EC2?

please, be sure your connected to a ubuntu server, I Had the same problem but I was connected to other distro, check the AMI value in your details instance, it should be something like

AMI: ubuntu/images/ebs/ubuntu-precise-12.04-amd64-server-20130411.1 

hope it helps

How do you delete an ActiveRecord object?

It's destroy and destroy_all methods, like

user.destroy
User.find(15).destroy
User.destroy(15)
User.where(age: 20).destroy_all
User.destroy_all(age: 20)

Alternatively you can use delete and delete_all which won't enforce :before_destroy and :after_destroy callbacks or any dependent association options.

User.delete_all(condition: 'value') will allow you to delete records without a primary key

Note: from @hammady's comment, user.destroy won't work if User model has no primary key.

Note 2: From @pavel-chuchuva's comment, destroy_all with conditions and delete_all with conditions has been deprecated in Rails 5.1 - see guides.rubyonrails.org/5_1_release_notes.html

How to convert file to base64 in JavaScript?

Building up on Dmitri Pavlutin and joshua.paling answers, here's an extended version that extracts the base64 content (removes the metadata at the beginning) and also ensures padding is done correctly.

function getBase64(file) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = () => {
      let encoded = reader.result.toString().replace(/^data:(.*,)?/, '');
      if ((encoded.length % 4) > 0) {
        encoded += '='.repeat(4 - (encoded.length % 4));
      }
      resolve(encoded);
    };
    reader.onerror = error => reject(error);
  });
}

Fragment onCreateView and onActivityCreated called twice

I was scratching my head about this for a while too, and since Dave's explanation is a little hard to understand I'll post my (apparently working) code:

private class TabListener<T extends Fragment> implements ActionBar.TabListener {
    private Fragment mFragment;
    private Activity mActivity;
    private final String mTag;
    private final Class<T> mClass;

    public TabListener(Activity activity, String tag, Class<T> clz) {
        mActivity = activity;
        mTag = tag;
        mClass = clz;
        mFragment=mActivity.getFragmentManager().findFragmentByTag(mTag);
    }

    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        if (mFragment == null) {
            mFragment = Fragment.instantiate(mActivity, mClass.getName());
            ft.replace(android.R.id.content, mFragment, mTag);
        } else {
            if (mFragment.isDetached()) {
                ft.attach(mFragment);
            }
        }
    }

    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        if (mFragment != null) {
            ft.detach(mFragment);
        }
    }

    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }
}

As you can see it's pretty much like the Android sample, apart from not detaching in the constructor, and using replace instead of add.

After much headscratching and trial-and-error I found that finding the fragment in the constructor seems to make the double onCreateView problem magically go away (I assume it just ends up being null for onTabSelected when called through the ActionBar.setSelectedNavigationItem() path when saving/restoring state).

Delete all the records

from a table?

You can use this if you have no foreign keys to other tables

truncate table TableName

or

delete TableName

if you want all tables

sp_msforeachtable 'delete ?'

Normalizing a list of numbers in Python

For ones who wanna use scikit-learn, you can use

from sklearn.preprocessing import normalize

x = [1,2,3,4]
normalize([x]) # array([[0.18257419, 0.36514837, 0.54772256, 0.73029674]])
normalize([x], norm="l1") # array([[0.1, 0.2, 0.3, 0.4]])
normalize([x], norm="max") # array([[0.25, 0.5 , 0.75, 1.]])

How do I merge a git tag onto a branch

I'm late to the game here, but another approach could be:

1) create a branch from the tag ($ git checkout -b [new branch name] [tag name])

2) create a pull-request to merge with your new branch into the destination branch

Cannot run Eclipse; JVM terminated. Exit code=13

You need to check if your PC has a 64-bit or 32-bit operating system, then same goes for your JDK (64-bit/32-bit) and also for Eclipse (64-bit/32-bit).

Make sure they are all the same; if not, you need to download the one that matches your bitness.

Count lines in large files

Let us assume:

  • Your file system is distributed
  • Your file system can easily fill the network connection to a single node
  • You access your files like normal files

then you really want to chop the files into parts, count parts in parallel on multiple nodes and sum up the results from there (this is basically @Chris White's idea).

Here is how you do that with GNU Parallel (version > 20161222). You need to list the nodes in ~/.parallel/my_cluster_hosts and you must have ssh access to all of them:

parwc() {
    # Usage:
    #   parwc -l file                                                                

    # Give one chunck per host                                                     
    chunks=$(cat ~/.parallel/my_cluster_hosts|wc -l)
    # Build commands that take a chunk each and do 'wc' on that                    
    # ("map")                                                                      
    parallel -j $chunks --block -1 --pipepart -a "$2" -vv --dryrun wc "$1" |
        # For each command                                                         
        #   log into a cluster host                                                
        #   cd to current working dir                                              
        #   execute the command                                                    
        parallel -j0 --slf my_cluster_hosts --wd . |
        # Sum up the number of lines                                               
        # ("reduce")                                                               
        perl -ne '$sum += $_; END { print $sum,"\n" }'
}

Use as:

parwc -l myfile
parwc -w myfile
parwc -c myfile

Regular expression to return text between parenthesis

If your problem is really just this simple, you don't need regex:

s[s.find("(")+1:s.find(")")]

How do you add a scroll bar to a div?

<div class="scrollingDiv">foo</div> 

div.scrollingDiv
{
   overflow:scroll;
}

Could not load file or assembly System.Net.Http, Version=4.0.0.0 with ASP.NET (MVC 4) Web API OData Prerelease

After modifying the References in the Web.config file as mentioned above, we resolved the references.

I was facing similar issue.

For us we have reference Microsoft.Data.Edm.dll and OData.dll and other assemblies from Program Files:

C:\Program Files (x86)\Microsoft WCF Data Services\5.0
                          \bin\.NETFramework\Microsoft.Data.Edm.dll

and

C:\Program Files (x86)\Microsoft WCF Data Services\5.0
                        \bin\.NETFramework\Microsoft.Data.OData.dll

and version was 5.6.4.

Once I change the reference of both assemblies to C:\....Project\packages\Microsoft.Data.Edm.5.6.0 , the issue was resolved

How do you get AngularJS to bind to the title attribute of an A tag?

It looks like ng-attr is a new directive in AngularJS 1.1.4 that you can possibly use in this case.

<!-- example -->
<a ng-attr-title="{{product.shortDesc}}"></a>

However, if you stay with 1.0.7, you can probably write a custom directive to mirror the effect.

Recursive Lock (Mutex) vs Non-Recursive Lock (Mutex)

The difference between a recursive and non-recursive mutex has to do with ownership. In the case of a recursive mutex, the kernel has to keep track of the thread who actually obtained the mutex the first time around so that it can detect the difference between recursion vs. a different thread that should block instead. As another answer pointed out, there is a question of the additional overhead of this both in terms of memory to store this context and also the cycles required for maintaining it.

However, there are other considerations at play here too.

Because the recursive mutex has a sense of ownership, the thread that grabs the mutex must be the same thread that releases the mutex. In the case of non-recursive mutexes, there is no sense of ownership and any thread can usually release the mutex no matter which thread originally took the mutex. In many cases, this type of "mutex" is really more of a semaphore action, where you are not necessarily using the mutex as an exclusion device but use it as synchronization or signaling device between two or more threads.

Another property that comes with a sense of ownership in a mutex is the ability to support priority inheritance. Because the kernel can track the thread owning the mutex and also the identity of all the blocker(s), in a priority threaded system it becomes possible to escalate the priority of the thread that currently owns the mutex to the priority of the highest priority thread that is currently blocking on the mutex. This inheritance prevents the problem of priority inversion that can occur in such cases. (Note that not all systems support priority inheritance on such mutexes, but it is another feature that becomes possible via the notion of ownership).

If you refer to classic VxWorks RTOS kernel, they define three mechanisms:

  • mutex - supports recursion, and optionally priority inheritance. This mechanism is commonly used to protect critical sections of data in a coherent manner.
  • binary semaphore - no recursion, no inheritance, simple exclusion, taker and giver does not have to be same thread, broadcast release available. This mechanism can be used to protect critical sections, but is also particularly useful for coherent signalling or synchronization between threads.
  • counting semaphore - no recursion or inheritance, acts as a coherent resource counter from any desired initial count, threads only block where net count against the resource is zero.

Again, this varies somewhat by platform - especially what they call these things, but this should be representative of the concepts and various mechanisms at play.

Accessing private member variables from prototype-defined functions

I have one solution, but I am not sure it is without flaws.

For it to work, you have to use the following structure:

  1. Use 1 private object that contains all private variables.
  2. Use 1 instance function.
  3. Apply a closure to the constructor and all prototype functions.
  4. Any instance created is done outside the closure defined.

Here is the code:

var TestClass = 
(function () {
    // difficult to be guessed.
    var hash = Math.round(Math.random() * Math.pow(10, 13) + + new Date());
    var TestClass = function () {
        var privateFields = {
            field1: 1,
            field2: 2
        };
        this.getPrivateFields = function (hashed) {
            if(hashed !== hash) {
                throw "Cannot access private fields outside of object.";
                // or return null;
            }
            return privateFields;
        };
    };

    TestClass.prototype.prototypeHello = function () {
        var privateFields = this.getPrivateFields(hash);
        privateFields.field1 = Math.round(Math.random() * 100);
        privateFields.field2 = Math.round(Math.random() * 100);
    };

    TestClass.prototype.logField1 = function () {
        var privateFields = this.getPrivateFields(hash);
        console.log(privateFields.field1);
    };

    TestClass.prototype.logField2 = function () {
        var privateFields = this.getPrivateFields(hash);
        console.log(privateFields.field2);
    };

    return TestClass;
})();

How this works is that it provides an instance function "this.getPrivateFields" to access the "privateFields" private variables object, but this function will only return the "privateFields" object inside the main closure defined (also prototype functions using "this.getPrivateFields" need to be defined inside this closure).

A hash produced during runtime and difficult to be guessed is used as parameters to make sure that even if "getPrivateFields" is called outside the scope of closure will not return the "privateFields" object.

The drawback is that we can not extend TestClass with more prototype functions outside the closure.

Here is some test code:

var t1 = new TestClass();
console.log('Initial t1 field1 is: ');
t1.logField1();
console.log('Initial t1 field2 is: ');
t1.logField2();
t1.prototypeHello();
console.log('t1 field1 is now: ');
t1.logField1();
console.log('t1 field2 is now: ');
t1.logField2();
var t2 = new TestClass();
console.log('Initial t2 field1 is: ');
t2.logField1();
console.log('Initial t2 field2 is: ');
t2.logField2();
t2.prototypeHello();
console.log('t2 field1 is now: ');
t2.logField1();
console.log('t2 field2 is now: ');
t2.logField2();

console.log('t1 field1 stays: ');
t1.logField1();
console.log('t1 field2 stays: ');
t1.logField2();

t1.getPrivateFields(11233);

EDIT: Using this method, it is also possible to "define" private functions.

TestClass.prototype.privateFunction = function (hashed) {
    if(hashed !== hash) {
        throw "Cannot access private function.";
    }
};

TestClass.prototype.prototypeHello = function () {
    this.privateFunction(hash);
};

Why does python use 'else' after for and while loops?

Because they didn't want to introduce a new keyword to the language. Each one steals an identifier and causes backwards compatibility problems, so it's usually a last resort.

PHP Connection failed: SQLSTATE[HY000] [2002] Connection refused

Using MAMP I changed the host=localhost to host=127.0.0.1. But a new issue came "connection refused"

Solved this by putting 'port' => '8889', in 'Datasources' => [

PyTorch: How to get the shape of a Tensor as a list of int

Previous answers got you list of torch.Size Here is how to get list of ints

listofints = [int(x) for x in tensor.shape]

Read environment variables in Node.js

process.env.ENV_VARIABLE

Where ENV_VARIABLE is the name of the variable you wish to access.

See Node.js docs for process.env.

C# loop - break vs. continue

break causes the program counter to jump out of the scope of the innermost loop

for(i = 0; i < 10; i++)
{
    if(i == 2)
        break;
}

Works like this

for(i = 0; i < 10; i++)
{
    if(i == 2)
        goto BREAK;
}
BREAK:;

continue jumps to the end of the loop. In a for loop, continue jumps to the increment expression.

for(i = 0; i < 10; i++)
{
    if(i == 2)
        continue;

    printf("%d", i);
}

Works like this

for(i = 0; i < 10; i++)
{
    if(i == 2)
        goto CONTINUE;

    printf("%d", i);

    CONTINUE:;
}

How to uninstall Python 2.7 on a Mac OS X 10.6.4?

Trying to uninstall Python with

brew uninstall python

will not remove the natively installed Python but rather the version installed with brew.

How do I reference a local image in React?

You need to wrap you image source path within {}

<img src={'path/to/one.jpeg'} />

You need to use require if using webpack

<img src={require('path/to/one.jpeg')} />

python: order a list of numbers without built-in sort, min, max function

You could do it easily by using min() function

`def asc(a):
    b=[]
    l=len(a)
    for i in range(l):
        x=min(a)
        b.append(x)
        a.remove(x)
    return b
 print asc([2,5,8,7,44,54,23])`

String to date in Oracle with milliseconds

I don't think you can use fractional seconds with to_date or the DATE type in Oracle. I think you need to_timestamp which returns a TIMESTAMP type.

How can I access iframe elements with Javascript?

Using jQuery you can use contents(). For example:

var inside = $('#one').contents();

Detect if a NumPy array contains at least one non-numeric value?

(np.where(np.isnan(A)))[0].shape[0] will be greater than 0 if A contains at least one element of nan, A could be an n x m matrix.

Example:

import numpy as np

A = np.array([1,2,4,np.nan])

if (np.where(np.isnan(A)))[0].shape[0]: 
    print "A contains nan"
else:
    print "A does not contain nan"

How to set bootstrap navbar active class with Angular JS?

First and foremost, this problem can be solved in a lot of ways. This way might not be the most elegant, but it cerntainly works.

Here is a simple solution you should be able to add to any project. You can just add a "pageKey" or some other property when you configure your route that you can use to key off of. Additionally, you can implement a listener on the $routeChangeSuccess method of the $route object to listen for the successful completion of a route change.

When your handler fires you get the page key, and use that key to locate elements that need to be "ACTIVE" for this page, and you apply the ACTIVE class.

Keep in mind you need a way to make ALL the elements "IN ACTIVE". As you can see i'm using the .pageKey class on my nav items to turn them all off, and I'm using the .pageKey_{PAGEKEY} to individually turn them on. Switching them all to inactive, would be considered a naive approach, potentially you'd get better performance by using the previous route to make only active items inactive, or you could alter the jquery selector to only select active items to be made inactive. Using jquery to select all active items is probably the best solution because it ensures everything is cleaned up for the current route in case of any css bugs that might have been present on the previous route.

Which would mean changing this line of code:

$(".pagekey").toggleClass("active", false);

to this one

$(".active").toggleClass("active", false);

Here is some sample code:

Given a bootstrap navbar of

<div class="navbar navbar-inverse">
    <div class="navbar-inner">
        <a class="brand" href="#">Title</a>
        <ul class="nav">
            <li><a href="#!/" class="pagekey pagekey_HOME">Home</a></li>
            <li><a href="#!/page1/create" class="pagekey pagekey_CREATE">Page 1 Create</a></li>
            <li><a href="#!/page1/edit/1" class="pagekey pagekey_EDIT">Page 1 Edit</a></li>
            <li><a href="#!/page1/published/1" class="pagekey pagekey_PUBLISH">Page 1 Published</a></li>
        </ul>
    </div>
</div>

And an angular module and controller like the following:

<script type="text/javascript">

    function Ctrl($scope, $http, $routeParams, $location, $route) {

    }



    angular.module('BookingFormBuilder', []).
        config(function ($routeProvider, $locationProvider) {
            $routeProvider.
                when('/', { 
                   template: 'I\'m on the home page', 
                   controller: Ctrl, 
                   pageKey: 'HOME' }).
                when('/page1/create', { 
                   template: 'I\'m on page 1 create', 
                   controller: Ctrl, 
                   pageKey: 'CREATE' }).
                when('/page1/edit/:id', { 
                   template: 'I\'m on page 1 edit {id}', 
                   controller: Ctrl, pageKey: 'EDIT' }).
                when('/page1/published/:id', { 
                   template: 'I\'m on page 1 publish {id}', 
                   controller: Ctrl, pageKey: 'PUBLISH' }).
                otherwise({ redirectTo: '/' });

            $locationProvider.hashPrefix("!");
        }).run(function ($rootScope, $http, $route) {

            $rootScope.$on("$routeChangeSuccess", 
                           function (angularEvent, 
                                     currentRoute,
                                     previousRoute) {

                var pageKey = currentRoute.pageKey;
                $(".pagekey").toggleClass("active", false);
                $(".pagekey_" + pageKey).toggleClass("active", true);
            });

        });

</script>

adb not finding my device / phone (MacOS X)

Just an extra bit of help: the device needs to be directly connected to the computer, connecting it to an USB hub might prevent the device prompt from displaying.

How can I display a tooltip message on hover using jQuery?

Following will work like a charm (assuming you have div/span/table/tr/td/etc with "id"="myId")

    $("#myId").hover(function() {
        $(this).css('cursor','pointer').attr('title', 'This is a hover text.');
    }, function() {
        $(this).css('cursor','auto');
    });

As a complimentary, .css('cursor','pointer') will change the mouse pointer on hover.

Material effect on button with background color

I came to this post looking for a way to have a background color of my ListView Item, yet keep the ripple.

I simply added my color as a background and the selectableItemBackground as a foreground:

<style name="my_list_item">
    <item name="android:background">@color/white</item>
    <item name="android:foreground">?attr/selectableItemBackground</item>
    <item name="android:layout_height">@dimen/my_list_item_height</item>
</style>

and it works like a charm. I guess the same technique could be used for buttons as well. Good luck :)

Endless loop in C/C++

It is very subjective. I write this:

while(true) {} //in C++

Because its intent is very much clear and it is also readable: you look at it and you know infinite loop is intended.

One might say for(;;) is also clear. But I would argue that because of its convoluted syntax, this option requires extra knowledge to reach the conclusion that it is an infinite loop, hence it is relatively less clear. I would even say there are more number of programmers who don't know what for(;;) does (even if they know usual for loop), but almost all programmers who knows while loop would immediately figure out what while(true) does.

To me, writing for(;;) to mean infinite loop, is like writing while() to mean infinite loop — while the former works, the latter does NOT. In the former case, empty condition turns out to be true implicitly, but in the latter case, it is an error! I personally didn't like it.

Now while(1) is also there in the competition. I would ask: why while(1)? Why not while(2), while(3) or while(0.1)? Well, whatever you write, you actually mean while(true) — if so, then why not write it instead?

In C (if I ever write), I would probably write this:

while(1) {} //in C

While while(2), while(3) and while(0.1) would equally make sense. But just to be conformant with other C programmers, I would write while(1), because lots of C programmers write this and I find no reason to deviate from the norm.

Get a specific bit from byte

While it's good to read and understand Josh's answer, you'll probably be happier using the class Microsoft provided for this purpose: System.Collections.BitArray It's available in all versions of .NET Framework.

What does -> mean in Python function definitions?

These are function annotations covered in PEP 3107. Specifically, the -> marks the return function annotation.

Examples:

>>> def kinetic_energy(m:'in KG', v:'in M/S')->'Joules': 
...    return 1/2*m*v**2
... 
>>> kinetic_energy.__annotations__
{'return': 'Joules', 'v': 'in M/S', 'm': 'in KG'}

Annotations are dictionaries, so you can do this:

>>> '{:,} {}'.format(kinetic_energy(20,3000),
      kinetic_energy.__annotations__['return'])
'90,000,000.0 Joules'

You can also have a python data structure rather than just a string:

>>> rd={'type':float,'units':'Joules','docstring':'Given mass and velocity returns kinetic energy in Joules'}
>>> def f()->rd:
...    pass
>>> f.__annotations__['return']['type']
<class 'float'>
>>> f.__annotations__['return']['units']
'Joules'
>>> f.__annotations__['return']['docstring']
'Given mass and velocity returns kinetic energy in Joules'

Or, you can use function attributes to validate called values:

def validate(func, locals):
    for var, test in func.__annotations__.items():
        value = locals[var]
        try: 
            pr=test.__name__+': '+test.__docstring__
        except AttributeError:
            pr=test.__name__   
        msg = '{}=={}; Test: {}'.format(var, value, pr)
        assert test(value), msg

def between(lo, hi):
    def _between(x):
            return lo <= x <= hi
    _between.__docstring__='must be between {} and {}'.format(lo,hi)       
    return _between

def f(x: between(3,10), y:lambda _y: isinstance(_y,int)):
    validate(f, locals())
    print(x,y)

Prints

>>> f(2,2) 
AssertionError: x==2; Test: _between: must be between 3 and 10
>>> f(3,2.1)
AssertionError: y==2.1; Test: <lambda>

how to get value of selected item in autocomplete

When autocomplete changes a value, it fires a autocompletechange event, not the change event

$(document).ready(function () {
    $('#tags').on('autocompletechange change', function () {
        $('#tagsname').html('You selected: ' + this.value);
    }).change();
});

Demo: Fiddle

Another solution is to use select event, because the change event is triggered only when the input is blurred

$(document).ready(function () {
    $('#tags').on('change', function () {
        $('#tagsname').html('You selected: ' + this.value);
    }).change();
    $('#tags').on('autocompleteselect', function (e, ui) {
        $('#tagsname').html('You selected: ' + ui.item.value);
    });
});

Demo: Fiddle

Error while installing json gem 'mkmf.rb can't find header files for ruby'

For Ubuntu 18, after checking log file mentioned while install

Results logged to /var/canvas/vendor/bundle/ruby/2.5.0/extensions/x86_64-linux/2.5.0/nio4r-2.5.2/gem_make.out

with

less /var/canvas/vendor/bundle/ruby/2.5.0/extensions/x86_64-linux/2.5.0/nio4r-2.5.2/gem_make.out

I noticed that make is not found. So installed make by

sudo apt-get install make

everything worked.

.NET DateTime to SqlDateTime Conversion

Also please remember resolutions [quantum of time] are different.

http://msdn.microsoft.com/en-us/library/system.data.sqltypes.sqldatetime.aspx

SQL one is 3.33 ms and .net one is 100 ns.

In a unix shell, how to get yesterday's date into a variable?

On Linux, you can use

date -d "-1 days" +"%a %d/%m/%Y"

Getting value of HTML Checkbox from onclick/onchange events

Use this

<input type="checkbox" onclick="onClickHandler()" id="box" />

<script>
function onClickHandler(){
    var chk=document.getElementById("box").value;

    //use this value

}
</script>

draw diagonal lines in div background with CSS

you can use a CSS3 transform Property:

div
{
transform:rotate(Xdeg);
-ms-transform:rotate(Xdeg); /* IE 9 */
-webkit-transform:rotate(Xdeg); /* Safari and Chrome */
}

Xdeg = your value

For example...

You can make more div and use a z-index property. So,make a div with line, and rotate it.

How can I generate Javadoc comments in Eclipse?

At a place where you want javadoc, type in /**<NEWLINE> and it will create the template.

Case-insensitive search in Rails model

There are lots of great answers here, particularly @oma's. But one other thing you could try is to use custom column serialization. If you don't mind everything being stored lowercase in your db then you could create:

# lib/serializers/downcasing_string_serializer.rb
module Serializers
  class DowncasingStringSerializer
    def self.load(value)
      value
    end

    def self.dump(value)
      value.downcase
    end
  end
end

Then in your model:

# app/models/my_model.rb
serialize :name, Serializers::DowncasingStringSerializer
validates_uniqueness_of :name, :case_sensitive => false

The benefit of this approach is that you can still use all the regular finders (including find_or_create_by) without using custom scopes, functions, or having lower(name) = ? in your queries.

The downside is that you lose casing information in the database.

CSS media query to target only iOS devices

Yes, you can.

@supports (-webkit-touch-callout: none) {
  /* CSS specific to iOS devices */ 
}

@supports not (-webkit-touch-callout: none) {
  /* CSS for other than iOS devices */ 
}

YMMV.

It works because only Safari Mobile implements -webkit-touch-callout: https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-touch-callout

Please note that @supports does not work in IE. IE will skip both of the above @support blocks above. To find out more see https://hacks.mozilla.org/2016/08/using-feature-queries-in-css/. It is recommended to not use @supports not because of this.

What about Chrome or Firefox on iOS? The reality is these are just skins over the WebKit rendering engine. Hence the above works everywhere on iOS as long as iOS policy does not change. See 2.5.6 in App Store Review Guidelines.

Warning: iOS may remove support for this in any new iOS release in the coming years. You SHOULD try a bit harder to not need the above CSS. An earlier version of this answer used -webkit-overflow-scrolling but a new iOS version removed it. As a commenter pointed out, there are other options to choose from: Go to Supported CSS Properties and search for "Safari on iOS".

How to check that a string is parseable to a double?

Apache, as usual, has a good answer from Apache Commons-Lang in the form of NumberUtils.isCreatable(String).

Handles nulls, no try/catch block required.

I can’t find the Android keytool

No need to use the command line.

If you FILE-> "Export Android Application" in the ADK then it will allow you to create a key and then produce your .apk file.

How to use google maps without api key

Now you must have API key. You can generate that in google developer console. Here is LINK to the explanation.

Getting the minimum of two values in SQL

This works for up to 5 dates and handles nulls. Just couldn't get it to work as an Inline function.

CREATE FUNCTION dbo.MinDate(@Date1 datetime = Null,
                            @Date2 datetime = Null,
                            @Date3 datetime = Null,
                            @Date4 datetime = Null,
                            @Date5 datetime = Null)
RETURNS Datetime AS
BEGIN
--USAGE select dbo.MinDate('20120405',null,null,'20110305',null)
DECLARE @Output datetime;

WITH Datelist_CTE(DT)
AS (
        SELECT @Date1 AS DT WHERE @Date1 is not NULL UNION
        SELECT @Date2 AS DT WHERE @Date2 is not NULL UNION
        SELECT @Date3 AS DT WHERE @Date3 is not NULL UNION
        SELECT @Date4 AS DT WHERE @Date4 is not NULL UNION
        SELECT @Date5 AS DT WHERE @Date5 is not NULL
   )
Select @Output=Min(DT) FROM Datelist_CTE

RETURN @Output
END

Overflow Scroll css is not working in the div

I edited your: Fiddle

html, body{ margin:0; padding:0; overflow:hidden; height:100% }
.header { margin: 0 auto; width:500px; height:30px; background-color:#dadada;}
.wrapper{ margin: 0 auto; width:500px; overflow:scroll; height: 100%;}

Giving the html-tag a 100% height is the solution. I also deleted the container div. You don't need it when your layout stays like this.

Running ASP.Net on a Linux based server

I can speak from experience. Even if your ASP.net website only uses .NET libraries supported by Mono you are going to have a hard time getting it to run if its anything beyond Hello World.

You won't have to re-write much code but you will spend hours/days/weeks dealing with little issues with mod_mono/xsp/apache configuration and file permissions and error handling and all the little things that go into a large website. (Be prepared to spend a lot of time asking questions on serverfault :) )

The problem is that a lot of people don't use Mono for ASP.net websites and so there aren't as many people reporting bugs so a lot of things that are minor bugs go un-fixed for a long time.

How to hide the border for specified rows of a table?

I use this with good results:

border-style:hidden;

It also works for:

border-right-style:hidden; /*if you want to hide just a border on a cell*/

Example:

_x000D_
_x000D_
<style type="text/css">_x000D_
      table, th, td {_x000D_
       border: 2px solid green;_x000D_
      }_x000D_
      tr.hide_right > td, td.hide_right{_x000D_
        border-right-style:hidden;_x000D_
      }_x000D_
      tr.hide_all > td, td.hide_all{_x000D_
        border-style:hidden;_x000D_
      }_x000D_
  }_x000D_
</style>_x000D_
<table>_x000D_
  <tr>_x000D_
    <td class="hide_right">11</td>_x000D_
    <td>12</td>_x000D_
    <td class="hide_all">13</td>_x000D_
  </tr>_x000D_
  <tr class="hide_right">_x000D_
    <td>21</td>_x000D_
    <td>22</td>_x000D_
    <td>23</td>_x000D_
  </tr>_x000D_
  <tr class="hide_all">_x000D_
    <td>31</td>_x000D_
    <td>32</td>_x000D_
    <td>33</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Here is the result: enter image description here

How to change Bootstrap's global default font size?

There are several ways but since you are using just the CSS version and not the SASS or LESS versions, your best bet to use Bootstraps own customization tool:

http://getbootstrap.com/customize/

Customize whatever you want on this page and then you can download a custom build with your own font sizes and anything else you want to change.

Altering the CSS file directly (or simply adding new CSS styles that override the Bootstrap CSS) is not recommended because other Bootstrap styles' values are derived from the base font size. For example:

https://github.com/twbs/bootstrap-sass/blob/master/assets/stylesheets/bootstrap/_variables.scss#L52

You can see that the base font size is used to calculate the sizes of the h1, h2, h3 etc. If you just changed the font size in the CSS (or added your own overriding font-size) all the other values that used the font size in calculations would no longer be proportionally accurate according to Bootstrap's design.

As I said, your best bet is to just use their own Customize tool. That is exactly what it's for.

If you are using SASS or LESS, you would change the font size in the variables file before compiling.

How to install XNA game studio on Visual Studio 2012?

I found another issue, for some reason if the extensions are cached in the local AppData folder, the XNA extensions never get loaded.

You need to remove the files extensionSdks.en-US.cache and extensions.en-US.cache from the %LocalAppData%\Microsoft\VisualStudio\11.0\Extensions folder. These files are rebuilt the next time you launch

If you need access to the Visual Studio startup log to debug what's happening, run devenv.exe /log command from the C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE directory (assuming you are on a 64 bit machine). The log file generated is located here:

%AppData%\Microsoft\VisualStudio\11.0\ActivityLog.xml

How to import and export components using React + ES6 + webpack?

To export a single component in ES6, you can use export default as follows:

class MyClass extends Component {
 ...
}

export default MyClass;

And now you use the following syntax to import that module:

import MyClass from './MyClass.react'

If you are looking to export multiple components from a single file the declaration would look something like this:

export class MyClass1 extends Component {
 ...
}

export class MyClass2 extends Component {
 ...
}

And now you can use the following syntax to import those files:

import {MyClass1, MyClass2} from './MyClass.react'

C++, How to determine if a Windows Process is running?

This is a solution that I've used in the past. Although the example here is in VB.net - I've used this technique with c and c++. It bypasses all the issues with Process IDs & Process handles, and return codes. Windows is very faithful in releasing the mutex no matter how Process2 is terminated. I hope it is helpful to someone...

**PROCESS1 :-**

    Randomize()
    mutexname = "myprocess" & Mid(Format(CDbl(Long.MaxValue) * Rnd(), "00000000000000000000"), 1, 16)
    hnd = CreateMutex(0, False, mutexname)

    ' pass this name to Process2
    File.WriteAllText("mutexname.txt", mutexname)

    <start Process2>
    <wait for Process2 to start>

    pr = WaitForSingleObject(hnd, 0)
    ReleaseMutex(hnd)

    If pr = WAIT_OBJECT_0 Then

         <Process2 not running>

    Else

         <Process2 is running>

    End If
    ...

    CloseHandle(hnd)
    EXIT

    **PROCESS2 :-**

    mutexname = File.ReadAllText("mutexname.txt")
    hnd = OpenMutex(MUTEX_ALL_ACCESS Or SYNCHRONIZE, True, mutexname)
    ...

    ReleaseMutex(hnd)
    CloseHandle(hnd)
    EXIT

Matplotlib - global legend and title aside subplots

Global title: In newer releases of matplotlib one can use Figure.suptitle() method of Figure:

import matplotlib.pyplot as plt
fig = plt.gcf()
fig.suptitle("Title centered above all subplots", fontsize=14)

Alternatively (based on @Steven C. Howell's comment below (thank you!)), use the matplotlib.pyplot.suptitle() function:

 import matplotlib.pyplot as plt
 # plot stuff
 # ...
 plt.suptitle("Title centered above all subplots", fontsize=14)

How to round to 2 decimals with Python?

float(str(round(answer, 2)))
float(str(round(0.0556781255, 2)))