Programs & Examples On #Translucency

Valid characters of a hostname?

It depends on whether you process IDNs before or after the IDN toASCII algorithm (that is, do you see the domain name pa??de??µa.d???µ? in Greek or as xn--hxajbheg2az3al.xn--jxalpdlp?).

In the latter case—where you are handling IDNs through the punycode—the old RFC 1123 rules apply:

U+0041 through U+005A (A-Z), U+0061 through U+007A (a-z) case folded as each other, U+0030 through U+0039 (0-9) and U+002D (-).

and U+002E (.) of course; the rules for labels allow the others, with dots between labels.

If you are seeing it in IDN form, the allowed characters are much varied, see http://unicode.org/reports/tr36/idn-chars.html for a handy chart of all valid characters.

Chances are your network code will deal with the punycode, but your display code (or even just passing strings to and from other layers) with the more human-readable form as nobody running a server on the ????????. domain wants to see their server listed as being on .xn--mgberp4a5d4ar.

C# Example of AES256 encryption using System.Security.Cryptography.Aes

public class AesCryptoService
{
    private static byte[] Key = Encoding.ASCII.GetBytes(@"qwr{@^h`h&_`50/ja9!'dcmh3!uw<&=?");
    private static byte[] IV = Encoding.ASCII.GetBytes(@"9/\~V).A,lY&=t2b");


    public static string EncryptStringToBytes_Aes(string plainText)
    {
        if (plainText == null || plainText.Length <= 0)
            throw new ArgumentNullException("plainText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("IV");
        byte[] encrypted;


        using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;
            aesAlg.Mode = CipherMode.CBC;
            aesAlg.Padding = PaddingMode.PKCS7;

            ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }
        
        return Convert.ToBase64String(encrypted);
    }


    
    public static string DecryptStringFromBytes_Aes(string Text)
    {
        if (Text == null || Text.Length <= 0)
            throw new ArgumentNullException("cipherText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("IV");

        string plaintext = null;
        byte[] cipherText = Convert.FromBase64String(Text.Replace(' ', '+'));

        using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
        {
            aesAlg.Key = Key;
            aesAlg.IV = IV;
            aesAlg.Mode = CipherMode.CBC;
            aesAlg.Padding = PaddingMode.PKCS7;


            ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);

            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }

        }

        return plaintext;
    }
}

Where value in column containing comma delimited values

I found this answer on another forum, works perfect. No problems with finding 1 if there is also a 10

WHERE tablename REGEXP "(^|,)@search(,|$)"

I found it here

How do I convert a PDF document to a preview image in PHP?

I install finished! It's worked!

You may be do base install imagemagick on windows.

In php (local) use call exec(<command line>) ex:

<?php
$pdf = "filename.pdf";
$info = pathinfo($pdf);
$file_name =  basename($pdf,'.'.$info['extension']);
echo $file_name;
$pdf = "filename.pdf[0]";
exec("convert $pdf convert-img/$file_name.jpg");    
?>

Besides, you may be use class imagick in PHP Imagick class

Thanks all helped me!

How to find the foreach index?

I solved this way, when I had to use the foreach index and value in the same context:

$array = array('a', 'b', 'c');
foreach ($array as $letter=>$index) {

  echo $letter; //Here $letter content is the actual index
  echo $array[$letter]; // echoes the array value

}//foreach

ReactNative: how to center text?

this is a example for Horizontal and Vertical alignment simultaneously

<View style={{width: 200, flexDirection: 'row',alignItems: 'center'}}>
     <Text style={{width: '100%',textAlign: 'center'}} />
</View>

Chmod recursively

Try to change all the persmissions at the same time:

chmod -R +xr

AngularJS ng-click stopPropagation

An addition to Stewie's answer. In case when your callback decides whether the propagation should be stopped or not, I found it useful to pass the $event object to the callback:

<div ng-click="parentHandler($event)">
  <div ng-click="childHandler($event)">
  </div>
</div>

And then in the callback itself, you can decide whether the propagation of the event should be stopped:

$scope.childHandler = function ($event) {
  if (wanna_stop_it()) {
    $event.stopPropagation();
  }
  ...
};

Differences between "BEGIN RSA PRIVATE KEY" and "BEGIN PRIVATE KEY"

See https://polarssl.org/kb/cryptography/asn1-key-structures-in-der-and-pem (search the page for "BEGIN RSA PRIVATE KEY") (archive link for posterity, just in case).

BEGIN RSA PRIVATE KEY is PKCS#1 and is just an RSA key. It is essentially just the key object from PKCS#8, but without the version or algorithm identifier in front. BEGIN PRIVATE KEY is PKCS#8 and indicates that the key type is included in the key data itself. From the link:

The unencrypted PKCS#8 encoded data starts and ends with the tags:

-----BEGIN PRIVATE KEY-----
BASE64 ENCODED DATA
-----END PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

PrivateKeyInfo ::= SEQUENCE {
  version         Version,
  algorithm       AlgorithmIdentifier,
  PrivateKey      BIT STRING
}

AlgorithmIdentifier ::= SEQUENCE {
  algorithm       OBJECT IDENTIFIER,
  parameters      ANY DEFINED BY algorithm OPTIONAL
}

So for an RSA private key, the OID is 1.2.840.113549.1.1.1 and there is a RSAPrivateKey as the PrivateKey key data bitstring.

As opposed to BEGIN RSA PRIVATE KEY, which always specifies an RSA key and therefore doesn't include a key type OID. BEGIN RSA PRIVATE KEY is PKCS#1:

RSA Private Key file (PKCS#1)

The RSA private key PEM file is specific for RSA keys.

It starts and ends with the tags:

-----BEGIN RSA PRIVATE KEY-----
BASE64 ENCODED DATA
-----END RSA PRIVATE KEY-----

Within the base64 encoded data the following DER structure is present:

RSAPrivateKey ::= SEQUENCE {
  version           Version,
  modulus           INTEGER,  -- n
  publicExponent    INTEGER,  -- e
  privateExponent   INTEGER,  -- d
  prime1            INTEGER,  -- p
  prime2            INTEGER,  -- q
  exponent1         INTEGER,  -- d mod (p-1)
  exponent2         INTEGER,  -- d mod (q-1)
  coefficient       INTEGER,  -- (inverse of q) mod p
  otherPrimeInfos   OtherPrimeInfos OPTIONAL
}

ArrayList filter

Probably the best way is to use Guava

List<String> list = new ArrayList<String>();
list.add("How are you");
list.add("How you doing");
list.add("Joe");
list.add("Mike");
    
Collection<String> filtered = Collections2.filter(list,
    Predicates.containsPattern("How"));
print(filtered);

prints

How are you
How you doing

In case you want to get the filtered collection as a list, you can use this (also from Guava):

List<String> filteredList = Lists.newArrayList(Collections2.filter(
    list, Predicates.containsPattern("How")));

How to set background color in jquery

How about this:

$(this).css('background-color', '#FFFFFF');

Related post: Add background color and border to table row on hover using jquery

A simple scenario using wait() and notify() in java

The wait() and notify() methods are designed to provide a mechanism to allow a thread to block until a specific condition is met. For this I assume you're wanting to write a blocking queue implementation, where you have some fixed size backing-store of elements.

The first thing you have to do is to identify the conditions that you want the methods to wait for. In this case, you will want the put() method to block until there is free space in the store, and you will want the take() method to block until there is some element to return.

public class BlockingQueue<T> {

    private Queue<T> queue = new LinkedList<T>();
    private int capacity;

    public BlockingQueue(int capacity) {
        this.capacity = capacity;
    }

    public synchronized void put(T element) throws InterruptedException {
        while(queue.size() == capacity) {
            wait();
        }

        queue.add(element);
        notify(); // notifyAll() for multiple producer/consumer threads
    }

    public synchronized T take() throws InterruptedException {
        while(queue.isEmpty()) {
            wait();
        }

        T item = queue.remove();
        notify(); // notifyAll() for multiple producer/consumer threads
        return item;
    }
}

There are a few things to note about the way in which you must use the wait and notify mechanisms.

Firstly, you need to ensure that any calls to wait() or notify() are within a synchronized region of code (with the wait() and notify() calls being synchronized on the same object). The reason for this (other than the standard thread safety concerns) is due to something known as a missed signal.

An example of this, is that a thread may call put() when the queue happens to be full, it then checks the condition, sees that the queue is full, however before it can block another thread is scheduled. This second thread then take()'s an element from the queue, and notifies the waiting threads that the queue is no longer full. Because the first thread has already checked the condition however, it will simply call wait() after being re-scheduled, even though it could make progress.

By synchronizing on a shared object, you can ensure that this problem does not occur, as the second thread's take() call will not be able to make progress until the first thread has actually blocked.

Secondly, you need to put the condition you are checking in a while loop, rather than an if statement, due to a problem known as spurious wake-ups. This is where a waiting thread can sometimes be re-activated without notify() being called. Putting this check in a while loop will ensure that if a spurious wake-up occurs, the condition will be re-checked, and the thread will call wait() again.


As some of the other answers have mentioned, Java 1.5 introduced a new concurrency library (in the java.util.concurrent package) which was designed to provide a higher level abstraction over the wait/notify mechanism. Using these new features, you could rewrite the original example like so:

public class BlockingQueue<T> {

    private Queue<T> queue = new LinkedList<T>();
    private int capacity;
    private Lock lock = new ReentrantLock();
    private Condition notFull = lock.newCondition();
    private Condition notEmpty = lock.newCondition();

    public BlockingQueue(int capacity) {
        this.capacity = capacity;
    }

    public void put(T element) throws InterruptedException {
        lock.lock();
        try {
            while(queue.size() == capacity) {
                notFull.await();
            }

            queue.add(element);
            notEmpty.signal();
        } finally {
            lock.unlock();
        }
    }

    public T take() throws InterruptedException {
        lock.lock();
        try {
            while(queue.isEmpty()) {
                notEmpty.await();
            }

            T item = queue.remove();
            notFull.signal();
            return item;
        } finally {
            lock.unlock();
        }
    }
}

Of course if you actually need a blocking queue, then you should use an implementation of the BlockingQueue interface.

Also, for stuff like this I'd highly recommend Java Concurrency in Practice, as it covers everything you could want to know about concurrency related problems and solutions.

Passing functions with arguments to another function in Python?

This is what lambda is for:

def perform(f):
    f()

perform(lambda: action1())
perform(lambda: action2(p))
perform(lambda: action3(p, r))

Python, how to check if a result set is empty?

if you're connecting to a postgres database, the following works:

result = cursor.execute(query)

if result.returns_rows:
    # we got rows!
    return [{k:v for k,v in zip(result.keys(), r)} for r in result.rows]
else:
    return None

How do I make a redirect in PHP?

Use the following code:

header("Location: /index.php");
exit(0);   

What does cv::normalize(_src, dst, 0, 255, NORM_MINMAX, CV_8UC1);

When the normType is NORM_MINMAX, cv::normalize normalizes _src in such a way that the min value of dst is alpha and max value of dst is beta. cv::normalize does its magic using only scales and shifts (i.e. adding constants and multiplying by constants).

CV_8UC1 says how many channels dst has.

The documentation here is pretty clear: http://docs.opencv.org/modules/core/doc/operations_on_arrays.html#normalize

Using sed to mass rename files

The parentheses capture particular strings for use by the backslashed numbers.

.NET HashTable Vs Dictionary - Can the Dictionary be as fast?

If you care about reading that will always return the objects in the order they are inserted in a Dictionary, you may have a look at

OrderedDictionary - values can be accessed via an integer index (by order in which items were added) SortedDictionary - items are automatically sorted

MySQL - ERROR 1045 - Access denied

The current root password must be empty. Then under "new root password" enter your password and confirm.

How to update fields in a model without creating a new record in django?

You should do it this way ideally

t = TemperatureData.objects.get(id=1)
t.value = 999
t.save(['value'])

This allow you to specify which column should be saved and rest are left as they currently are in database. (https://code.djangoproject.com/ticket/4102)!

Converting a String to a List of Words?

This is from my attempt on a coding challenge that can't use regex,

outputList = "".join((c if c.isalnum() or c=="'" else ' ') for c in inputStr ).split(' ')

The role of apostrophe seems interesting.

Is it possible to start activity through adb shell?

adb shell am broadcast -a android.intent.action.xxx

Mention xxx as the action that you mentioned in the manifest file.

How can I check if a single character appears in a string?

To check if something does not exist in a string, you at least need to look at each character in a string. So even if you don't explicitly use a loop, it'll have the same efficiency. That being said, you can try using str.contains(""+char).

HashMap and int as key

The main reason with HashMap not allowing primitive as keys is that HashMap is designed in such a way that for comparing the keys, it makes use of equals() method, and a method can be called only on an object not on a primitive.

Thus when int is autoboxed to Integer, Hashmap can call equals() method on Integer object.

That is why, you should use Integer instead of int. I mean hashmap throws an error while putting int as a key (Don't know the meaning of the error that is thrown)

And if you think that, you can make Map performance faster by making a primitive as a key, there is a library called FastUtil which contains a Map implementation with int type as a key.

Because of this, it is much faster than Hashmap

Pycharm does not show plot

I tested in my version on PyCharm 2017.1.2. I used interactive (True) and show (block=True).

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
ts = pd.Series(np.random.randn(1000), index=pd.date_range('1//2000',periods=1000))
ts = ts.cumsum()
plt.interactive(True)
ts.plot()
plt.show(block=True)

How to create duplicate table with new name in SQL Server 2008

Here, I will show you 2 different implementation:

First:

If you just need to create a duplicate table then just run the command:

SELECT top 0 * INTO [dbo].[DuplicateTable]
FROM [dbo].[MainTable]

Of course, it doesn't work completely. constraints don't get copied, nor do primary keys, or default values. The command only creates a new table with the same column structure and if you want to insert data into the new table.

Second (recommended):

But If you want to duplicate the table with all its constraints & keys follows this below steps:

  1. Open the database in SQL Management Studio.
  2. Right-click on the table that you want to duplicate.
  3. Select Script Table as -> Create to -> New Query Editor Window. This will generate a script to recreate the table in a new query window.
  4. Change the table name and relative keys & constraints in the script.
  5. Execute the script.

DateTime format to SQL format using C#

Why not skip the string altogether :

SqlDateTime myDateTime = DateTime.Now;

Replace one character with another in Bash

Use inline shell string replacement. Example:

foo="  "

# replace first blank only
bar=${foo/ /.}

# replace all blanks
bar=${foo// /.}

See http://tldp.org/LDP/abs/html/string-manipulation.html for more details.

Do we have router.reload in vue-router?

Resolve the route to a URL and navigate the window with Javascript.

_x000D_
_x000D_
        let r = this.$router.resolve({_x000D_
        name: this.$route.name, // put your route information in_x000D_
        params: this.$route.params, // put your route information in_x000D_
        query: this.$route.query // put your route information in_x000D_
      });_x000D_
      window.location.assign(r.href)
_x000D_
_x000D_
_x000D_

This method replaces the URL and causes the page to do a full request (refresh) rather than relying on Vue.router. $router.go does not work the same for me even though it is theoretically supposed to.

Node Version Manager install - nvm command not found

Quick answer

Figure out the following:

  1. Which shell is your terminal using, type in: echo $0 to find out (normally works)
  2. Which start-up file does that shell load when starting up (NOT login shell starting file, the normal shell starting file, there is a difference!)
  3. Add source ~/.nvm/nvm.sh to that file (assuming that file exists at that location, it is the default install location)
  4. Start a new terminal session
  5. Profit?

Example

As you can see it states zsh and not bash. enter image description here

To fix this I needed to add source ~/.nvm/nvm.sh to the ~/.zshrc file as when starting a new terminal my Deepin Terminal zsh reads ~/.zshrc and not bashs ~/.bashrc.

Why does this happen

This happens because when installing NVM it adds code to ~/.bashrc, as my terminal Deepin Terminal uses zsh and not bash it never reads ~/.bashrc and therefor never loads NVM.

In other words: this is NVMs fault.

More on zsh can be read on one of the answers here.

Why does adb return offline after the device string?

Run SDk Manager and install Android SDK Tools and Android SDK Platform-tools updates. ADB must be updated to a new version for 4.2.x

How do I clone a github project to run locally?

You clone a repository with git clone [url]. Like so,

$ git clone https://github.com/libgit2/libgit2

How to get image height and width using java?

Simple way:

BufferedImage readImage = null;

try {
    readImage = ImageIO.read(new File(your path);
    int h = readImage.getHeight();
    int w = readImage.getWidth();
} catch (Exception e) {
    readImage = null;
}

How do I set the default Java installation/runtime (Windows)?

I just had that problem (Java 1.8 vs. Java 9 on Windows 7) and my findings are:

short version

default seems to be (because of Path entry)

c:\ProgramData\Oracle\Java\javapath\java -version

select the version you want (test, use tab completing in cmd, not sure what those numbers represent), I had 2 options, see longer version for details

c:\ProgramData\Oracle\Java\javapath_target_[tab]

remove junction/link and link to your version (the one ending with 181743567 in my case for Java 8)

rmdir javapath
mklink /D javapath javapath_target_181743567

longer version:

Reinstall Java 1.8 after Java 9 didn't work. The sequence of installations was jdk1.8.0_74, jdk-9.0.4 and attempt to make Java 8 default with jdk1.8.0_162...

After jdk1.8.0_162 installation I still have

java -version
java version "9.0.4"
Java(TM) SE Runtime Environment (build 9.0.4+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)

What I see in path is

Path=...;C:\ProgramData\Oracle\Java\javapath;...

So I checked what is that and I found it is a junction (link)

c:\ProgramData\Oracle\Java>dir
 Volume in drive C is OSDisk
 Volume Serial Number is DA2F-C2CC

 Directory of c:\ProgramData\Oracle\Java

2018-02-07  17:06    <DIR>          .
2018-02-07  17:06    <DIR>          ..
2018-02-08  17:08    <DIR>          .oracle_jre_usage
2017-08-22  11:04    <DIR>          installcache
2018-02-08  17:08    <DIR>          installcache_x64
2018-02-07  17:06    <JUNCTION>     javapath [C:\ProgramData\Oracle\Java\javapath_target_185258831]
2018-02-07  17:06    <DIR>          javapath_target_181743567
2018-02-07  17:06    <DIR>          javapath_target_185258831

Those hashes doesn't ring a bell, but when I checked

c:\ProgramData\Oracle\Java\javapath_target_181743567>.\java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)

c:\ProgramData\Oracle\Java\javapath_target_185258831>.\java -version
java version "9.0.4"
Java(TM) SE Runtime Environment (build 9.0.4+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)

so to make Java 8 default again I had to delete the link as described here

rmdir javapath

and recreate with Java I wanted

mklink /D javapath javapath_target_181743567

tested:

c:\ProgramData\Oracle\Java>java -version
java version "1.8.0_162"
Java(TM) SE Runtime Environment (build 1.8.0_162-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.162-b12, mixed mode)

** update (Java 10) **

With Java 10 it is similar, only javapath is in c:\Program Files (x86)\Common Files\Oracle\Java\ which is strange as I installed 64-bit IMHO

.\java -version
java version "10.0.2" 2018-07-17
Java(TM) SE Runtime Environment 18.3 (build 10.0.2+13)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.2+13, mixed mode)

Edit and replay XHR chrome/firefox etc?

Updating/completing zszep answer:

After copying the request as cUrl (bash), simply import it in the Postman App:

enter image description here

Visual Studio 2010 - recommended extensions

Align by - Obviously I'm bias since I wrote it but it's the extension I use more than any other.

Android Recyclerview GridLayoutManager column spacing

If you've scrolled far enough to reach this answer, I wrote a library for equal spacing which supports Vertical/Horizontal, LTR/RTL, LinearLayout/GridLayout manager and Edge inclusion. Its basically a single file, so you can copy paste that file into your code.

enter image description here

I tried to support StaggeredGridLayout but span index returned by this layout is not reliable. I would be glad to hear any suggestion for that.

If file exists then delete the file

You're close, you just need to delete the file before trying to over-write it.

dim infolder: set infolder = fso.GetFolder(IN_PATH)
dim file: for each file in infolder.Files

    dim name: name = file.name
    dim parts: parts = split(name, ".")

    if UBound(parts) = 2 then

       ' file name like a.c.pdf    

        dim newname: newname = parts(0) & "." & parts(2)
        dim newpath: newpath = fso.BuildPath(OUT_PATH, newname)

        ' warning:
        ' if we have source files C:\IN_PATH\ABC.01.PDF, C:\IN_PATH\ABC.02.PDF, ...
        ' only one of them will be saved as D:\OUT_PATH\ABC.PDF

        if fso.FileExists(newpath) then
            fso.DeleteFile newpath
        end if

        file.Move newpath

    end if

next

SOAP request in PHP with CURL

Tested and working!

  • with https, user & password

     <?php 
     //Data, connection, auth
     $dataFromTheForm = $_POST['fieldName']; // request data from the form
     $soapUrl = "https://connecting.website.com/soap.asmx?op=DoSomething"; // asmx URL of WSDL
     $soapUser = "username";  //  username
     $soapPassword = "password"; // password
    
     // xml post structure
    
     $xml_post_string = '<?xml version="1.0" encoding="utf-8"?>
                         <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
                           <soap:Body>
                             <GetItemPrice xmlns="http://connecting.website.com/WSDL_Service"> // xmlns value to be set to your WSDL URL
                               <PRICE>'.$dataFromTheForm.'</PRICE> 
                             </GetItemPrice >
                           </soap:Body>
                         </soap:Envelope>';   // data from the form, e.g. some ID number
    
        $headers = array(
                     "Content-type: text/xml;charset=\"utf-8\"",
                     "Accept: text/xml",
                     "Cache-Control: no-cache",
                     "Pragma: no-cache",
                     "SOAPAction: http://connecting.website.com/WSDL_Service/GetPrice", 
                     "Content-length: ".strlen($xml_post_string),
                 ); //SOAPAction: your op URL
    
         $url = $soapUrl;
    
         // PHP cURL  for https connection with auth
         $ch = curl_init();
         curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);
         curl_setopt($ch, CURLOPT_URL, $url);
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         curl_setopt($ch, CURLOPT_USERPWD, $soapUser.":".$soapPassword); // username and password - declared at the top of the doc
         curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
         curl_setopt($ch, CURLOPT_TIMEOUT, 10);
         curl_setopt($ch, CURLOPT_POST, true);
         curl_setopt($ch, CURLOPT_POSTFIELDS, $xml_post_string); // the SOAP request
         curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
    
         // converting
         $response = curl_exec($ch); 
         curl_close($ch);
    
         // converting
         $response1 = str_replace("<soap:Body>","",$response);
         $response2 = str_replace("</soap:Body>","",$response1);
    
         // convertingc to XML
         $parser = simplexml_load_string($response2);
         // user $parser to get your data out of XML response and to display it. 
     ?>
    

Ignoring NaNs with str.contains

I'm not 100% on why (actually came here to search for the answer), but this also works, and doesn't require replacing all nan values.

import pandas as pd
import numpy as np

df = pd.DataFrame([["foo1"], ["foo2"], ["bar"], [np.nan]], columns=['a'])

newdf = df.loc[df['a'].str.contains('foo') == True]

Works with or without .loc.

I have no idea why this works, as I understand it when you're indexing with brackets pandas evaluates whatever's inside the bracket as either True or False. I can't tell why making the phrase inside the brackets 'extra boolean' has any effect at all.

Alter table add multiple columns ms sql

Can with defaulth value (T-SQL)

ALTER TABLE
    Regions
ADD
    HasPhotoInReadyStorage BIT NULL, --this column is nullable
    HasPhotoInWorkStorage BIT NOT NULL, --this column is not nullable
    HasPhotoInMaterialStorage BIT NOT NULL DEFAULT(0) --this column default value is false
GO

How to execute Ant build in command line

Go to the Ant website and download. This way, you have a copy of Ant outside of Eclipse. I recommend to put it under the C:\ant directory. This way, it doesn't have any spaces in the directory names. In your System Control Panel, set the Environment Variable ANT_HOME to this directory, then pre-pend to the System PATHvariable, %ANT_HOME%\bin. This way, you don't have to put in the whole directory name.

Assuming you did the above, try this:

C:\> cd \Silk4J\Automation\iControlSilk4J
C:\Silk4J\Automation\iControlSilk4J> ant -d build

This will do several things:

  • It will eliminate the possibility that the problem is with Eclipe's version of Ant.
  • It is way easier to type
  • Since you're executing the build.xml in the directory where it exists, you don't end up with the possibility that your Ant build can't locate a particular directory.

The -d will print out a lot of output, so you might want to capture it, or set your terminal buffer to something like 99999, and run cls first to clear out the buffer. This way, you'll capture all of the output from the beginning in the terminal buffer.

Let's see how Ant should be executing. You didn't specify any targets to execute, so Ant should be taking the default build target. Here it is:

<target depends="build-subprojects,build-project" name="build"/>

The build target does nothing itself. However, it depends upon two other targets, so these will be called first:

The first target is build-subprojects:

<target name="build-subprojects"/>

This does nothing at all. It doesn't even have a dependency.

The next target specified is build-project does have code:

<target depends="init" name="build-project">

This target does contain tasks, and some dependent targets. Before build-project executes, it will first run the init target:

<target name="init">
    <mkdir dir="bin"/>
    <copy includeemptydirs="false" todir="bin">
        <fileset dir="src">
            <exclude name="**/*.java"/>
        </fileset>
    </copy>
</target>

This target creates a directory called bin, then copies all files under the src tree with the suffix *.java over to the bin directory. The includeemptydirs mean that directories without non-java code will not be created.

Ant uses a scheme to do minimal work. For example, if the bin directory is created, the <mkdir/> task is not executed. Also, if a file was previously copied, or there are no non-Java files in your src directory tree, the <copy/> task won't run. However, the init target will still be executed.

Next, we go back to our previous build-project target:

<target depends="init" name="build-project">
    <echo message="${ant.project.name}: ${ant.file}"/>
    <javac debug="true" debuglevel="${debuglevel}" destdir="bin" source="${source}" target="${target}">
        <src path="src"/>
        <classpath refid="iControlSilk4J.classpath"/>
    </javac>
</target>

Look at this line:

<echo message="${ant.project.name}: ${ant.file}"/>

That should have always executed. Did your output print:

[echo] iControlSilk4J: C:\Silk4J\Automation\iControlSilk4J\build.xml

Maybe you didn't realize that was from your build.

After that, it runs the <javac/> task. That is, if there's any files to actually compile. Again, Ant tries to avoid work it doesn't have to do. If all of the *.java files have previously been compiled, the <javac/> task won't execute.

And, that's the end of the build. Your build might not have done anything simply because there was nothing to do. You can try running the clean task, and then build:

C:\Silk4J\Automation\iControlSilk4J> ant -d clean build

However, Ant usually prints the target being executed. You should have seen this:

init:

build-subprojects:

build-projects:

    [echo] iControlSilk4J: C:\Silk4J\Automation\iControlSilk4J\build.xml

build:

Build Successful

Note that the targets are all printed out in order they're executed, and the tasks are printed out as they are executed. However, if there's nothing to compile, or nothing to copy, then you won't see these tasks being executed. Does this look like your output? If so, it could be there's nothing to do.

  • If the bin directory already exists, <mkdir/> isn't going to execute.
  • If there are no non-Java files in src, or they have already been copied into bin, the <copy/> task won't execute.
  • If there are no Java file in your src directory, or they have already been compiled, the <java/> task won't run.

If you look at the output from the -d debug, you'll see Ant looking at a task, then explaining why a particular task wasn't executed. Plus, the debug option will explain how Ant decides what tasks to execute.

See if that helps.

List of zeros in python

$ python3
>>> from itertools import repeat
>>> list(repeat(0, 7))
[0, 0, 0, 0, 0, 0, 0]

get path for my .exe

System.Reflection.Assembly.GetEntryAssembly().Location;

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

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

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

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


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

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

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

UPDATE

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

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

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

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

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

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


UPDATE 2:

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

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

Redis: How to access Redis log file

Found it with:

sudo tail /var/log/redis/redis-server.log -n 100

So if the setup was more standard that should be:

sudo tail /var/log/redis_6379.log -n 100

This outputs the last 100 lines of the file.

Where your log file is located is in your configs that you can access with:

redis-cli CONFIG GET *

The log file may not always be shown using the above. In that case use

tail -f `less  /etc/redis/redis.conf | grep logfile|cut -d\  -f2`

Integrating the ZXing library directly into my Android application

Since some of the answers are outdated, I would like to provide my own -

To integrate ZXing library into your Android app as suggested by their Wiki, you need to add 2 Java files to your project:

Then in Android Studio add the following line to build.gradle file:

dependencies {
    ....
    compile 'com.google.zxing:core:3.2.1'
}

Or if still using Eclipse with ADT-plugin add core.jar file to the libs subdirectory of your project (here fullscreen Windows and fullscreen Mac):

Windows screenshot

Finally add this code to your MainActivity.java:

public void scanQRCode(View v) {
    IntentIntegrator integrator = new IntentIntegrator(MainActivity.this);
    integrator.initiateScan(IntentIntegrator.QR_CODE_TYPES);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
    IntentResult result = 
        IntentIntegrator.parseActivityResult(requestCode, resultCode, intent);
    if (result != null) {
        String contents = result.getContents();
        if (contents != null) {
            showDialog(R.string.result_succeeded, result.toString());
        } else {
            showDialog(R.string.result_failed,
                getString(R.string.result_failed_why));
        }
    }
}

private void showDialog(int title, CharSequence message) {
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle(title);
    builder.setMessage(message);
    builder.setPositiveButton(R.string.ok_button, null);
    builder.show();
}

The resulting app will ask to install and start Barcode Scanner app by ZXing (which will return to your app automatically after scanning):

Barcode Scanner app

Additionally, if you would like to build and run the ZXing Test app as inspiration for your own app:

ZXing Test app

Then you need 4 Java files from GitHub:

  • BenchmarkActivity.java
  • BenchmarkAsyncTask.java
  • BenchmarkItem.java
  • ZXingTestActivity.java

And 3 Jar files from Maven repository:

  • core.jar
  • android-core.jar
  • android-integration.jar

(You can build the Jar files yourself with mvn package - if your check out ZXing from GitHub and install ant and maven tools at your computer).

Note: if your project does not recognize the Jar files, you might need to up the Java version in the Project Properties:

properties screenshot

SQL Server 2008 R2 can't connect to local database in Management Studio

I know, this problem can be faced by so many people and many of them have uninstalled and re-installed the sql server for resolving this issue. In my observation the problem of not connecting the database service locally is just because of your network connection you are using, in most of the cases these problems will come when you are using wi-fi network.

Solution is, if you are using wi-fi then just right click on status of the network and get the ip details and enter the same ip in sql server name, it will work. Regards Vishwajeet

How to disable clicking inside div

The CSS property that can be used is:

pointer-events:none

!IMPORTANT Keep in mind that this property is not supported by Opera Mini and IE 10 and below (inclusive). Another solution is needed for these browsers.

jQuery METHOD If you want to disable it via script and not CSS property, these can help you out: If you're using jQuery versions 1.4.3+:

$('selector').click(false);

If not:

$('selector').click(function(){return false;});

You can re-enable clicks with pointer-events: auto; (Documentation)

Note that pointer-events overrides the cursor property, so if you want the cursor to be something other than the standard cursor, your css should be place after pointer-events.

What's the best way to send a signal to all members of a process group?

rkill command from pslist package sends given signal (or SIGTERM by default) to specified process and all its descendants:

rkill [-SIG] pid/name...

Java, How do I get current index/key in "for each" loop

In Java, you can't, as foreach was meant to hide the iterator. You must do the normal For loop in order to get the current iteration.

A JNI error has occurred, please check your installation and try again in Eclipse x86 Windows 8.1

I had similar issues when using 'java' at the beginning of the package name, e.g. java.jem.pc

Check your console output, I was receiving:

Exception in thread "main" java.lang.SecurityException: Prohibited package name: java.jem.pc

MySQL, update multiple tables with one query

Take the case of two tables, Books and Orders. In case, we increase the number of books in a particular order with Order.ID = 1002 in Orders table then we also need to reduce that the total number of books available in our stock by the same number in Books table.

UPDATE Books, Orders
SET Orders.Quantity = Orders.Quantity + 2,
    Books.InStock = Books.InStock - 2
WHERE
    Books.BookID = Orders.BookID
    AND Orders.OrderID = 1002;

How to close an iframe within iframe itself

"Closing" the current iFrame is not possible but you can tell the parent to manipulate the dom and make it invisible.

In IFrame:

parent.closeIFrame();

In parent:

function closeIFrame(){
     $('#youriframeid').remove();
}

Best HTTP Authorization header type for JWT

The best HTTP header for your client to send an access token (JWT or any other token) is the Authorization header with the Bearer authentication scheme.

This scheme is described by the RFC6750.

Example:

GET /resource HTTP/1.1
Host: server.example.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIXVCJ9TJV...r7E20RMHrHDcEfxjoYZgeFONFh7HgQ

If you need stronger security protection, you may also consider the following IETF draft: https://tools.ietf.org/html/draft-ietf-oauth-pop-architecture. This draft seems to be a good alternative to the (abandoned?) https://tools.ietf.org/html/draft-ietf-oauth-v2-http-mac.

Note that even if this RFC and the above specifications are related to the OAuth2 Framework protocol, they can be used in any other contexts that require a token exchange between a client and a server.

Unlike the custom JWT scheme you mention in your question, the Bearer one is registered at the IANA.

Concerning the Basic and Digest authentication schemes, they are dedicated to authentication using a username and a secret (see RFC7616 and RFC7617) so not applicable in that context.

Can constructors be async?

I would use something like this.

 public class MyViewModel
    {
            public MyDataTable Data { get; set; }
            public MyViewModel()
               {
                   loadData(() => GetData());
               }
               private async void loadData(Func<DataTable> load)
               {
                  try
                  {
                      MyDataTable = await Task.Run(load);
                  }
                  catch (Exception ex)
                  {
                       //log
                  }
               }
               private DataTable GetData()
               {
                    DataTable data;
                    // get data and return
                    return data;
               }
    }

This is as close to I can get for constructors.

Where is jarsigner?

Find in /usr/lib/jvm/java-8-oracle/bin/jarsigner -verbose -sigalg SHA1withRSA

Using python's eval() vs. ast.literal_eval()?

Python's eager in its evaluation, so eval(input(...)) (Python 3) will evaluate the user's input as soon as it hits the eval, regardless of what you do with the data afterwards. Therefore, this is not safe, especially when you eval user input.

Use ast.literal_eval.


As an example, entering this at the prompt could be very bad for you:

__import__('os').system('rm -rf /a-path-you-really-care-about')

How to find the Number of CPU Cores via .NET/C#?

From .NET Framework source

You can also get it with PInvoke on Kernel32.dll

The following code is coming more or less from SystemInfo.cs from System.Web source located here:

[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct SYSTEM_INFO
{
  public ushort wProcessorArchitecture;
  public ushort wReserved;
  public uint dwPageSize;
  public IntPtr lpMinimumApplicationAddress;
  public IntPtr lpMaximumApplicationAddress;
  public IntPtr dwActiveProcessorMask;
  public uint dwNumberOfProcessors;
  public uint dwProcessorType;
  public uint dwAllocationGranularity;
  public ushort wProcessorLevel;
  public ushort wProcessorRevision;
}

internal static class SystemInfo 
{
    static int _trueNumberOfProcessors;
    internal static readonly IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);    

    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    internal static extern void GetSystemInfo(out SYSTEM_INFO si);

    [DllImport("kernel32.dll")]
    internal static extern int GetProcessAffinityMask(IntPtr handle, out IntPtr processAffinityMask, out IntPtr systemAffinityMask);

    internal static int GetNumProcessCPUs()
    {
      if (SystemInfo._trueNumberOfProcessors == 0)
      {
        SYSTEM_INFO si;
        GetSystemInfo(out si);
        if ((int) si.dwNumberOfProcessors == 1)
        {
          SystemInfo._trueNumberOfProcessors = 1;
        }
        else
        {
          IntPtr processAffinityMask;
          IntPtr systemAffinityMask;
          if (GetProcessAffinityMask(INVALID_HANDLE_VALUE, out processAffinityMask, out systemAffinityMask) == 0)
          {
            SystemInfo._trueNumberOfProcessors = 1;
          }
          else
          {
            int num1 = 0;
            if (IntPtr.Size == 4)
            {
              uint num2 = (uint) (int) processAffinityMask;
              while ((int) num2 != 0)
              {
                if (((int) num2 & 1) == 1)
                  ++num1;
                num2 >>= 1;
              }
            }
            else
            {
              ulong num2 = (ulong) (long) processAffinityMask;
              while ((long) num2 != 0L)
              {
                if (((long) num2 & 1L) == 1L)
                  ++num1;
                num2 >>= 1;
              }
            }
            SystemInfo._trueNumberOfProcessors = num1;
          }
        }
      }
      return SystemInfo._trueNumberOfProcessors;
    }
}

MySQL: How to add one day to datetime field in query

You can try this:

SELECT DATE(DATE_ADD(m_inv_reqdate, INTERVAL + 1 DAY)) FROM  tr08_investment

How to read a text file from server using JavaScript?

I used Rafid's suggestion of using AJAX.

This worked for me:

var url = "http://www.example.com/file.json";

var jsonFile = new XMLHttpRequest();
    jsonFile.open("GET",url,true);
    jsonFile.send();

    jsonFile.onreadystatechange = function() {
        if (jsonFile.readyState== 4 && jsonFile.status == 200) {
            document.getElementById("id-of-element").innerHTML = jsonFile.responseText;
        }
     }

I basically(almost literally) copied this code from http://www.w3schools.com/ajax/tryit.asp?filename=tryajax_get2 so credit to them for everything.

I dont have much knowledge of how this works but you don't have to know how your brakes work to use them ;)

Hope this helps!

MySQL Select Query - Get only first 10 characters of a value

Have a look at either Left or Substring if you need to chop it up even more.

Google and the MySQL docs are a good place to start - you'll usually not get such a warm response if you've not even tried to help yourself before asking a question.

Conda command not found

If you're using zsh and it has not been set up to read .bashrc, you need to add the Miniconda directory to the zsh shell PATH environment variable. Add this to your .zshrc:

export PATH="/home/username/miniconda/bin:$PATH"

Make sure to replace /home/username/miniconda with your actual path.

Save, exit the terminal and then reopen the terminal. conda command should work.

How are people unit testing with Entity Framework 6, should you bother?

I want to share an approach commented about and briefly discussed but show an actual example that I am currently using to help unit test EF-based services.

First, I would love to use the in-memory provider from EF Core, but this is about EF 6. Furthermore, for other storage systems like RavenDB, I'd also be a proponent of testing via the in-memory database provider. Again--this is specifically to help test EF-based code without a lot of ceremony.

Here are the goals I had when coming up with a pattern:

  • It must be simple for other developers on the team to understand
  • It must isolate the EF code at the barest possible level
  • It must not involve creating weird multi-responsibility interfaces (such as a "generic" or "typical" repository pattern)
  • It must be easy to configure and setup in a unit test

I agree with previous statements that EF is still an implementation detail and it's okay to feel like you need to abstract it in order to do a "pure" unit test. I also agree that ideally, I would want to ensure the EF code itself works--but this involves a sandbox database, in-memory provider, etc. My approach solves both problems--you can safely unit test EF-dependent code and create integration tests to test your EF code specifically.

The way I achieved this was through simply encapsulating EF code into dedicated Query and Command classes. The idea is simple: just wrap any EF code in a class and depend on an interface in the classes that would've originally used it. The main issue I needed to solve was to avoid adding numerous dependencies to classes and setting up a lot of code in my tests.

This is where a useful, simple library comes in: Mediatr. It allows for simple in-process messaging and it does it by decoupling "requests" from the handlers that implement the code. This has an added benefit of decoupling the "what" from the "how". For example, by encapsulating the EF code into small chunks it allows you to replace the implementations with another provider or totally different mechanism, because all you are doing is sending a request to perform an action.

Utilizing dependency injection (with or without a framework--your preference), we can easily mock the mediator and control the request/response mechanisms to enable unit testing EF code.

First, let's say we have a service that has business logic we need to test:

public class FeatureService {

  private readonly IMediator _mediator;

  public FeatureService(IMediator mediator) {
    _mediator = mediator;
  }

  public async Task ComplexBusinessLogic() {
    // retrieve relevant objects

    var results = await _mediator.Send(new GetRelevantDbObjectsQuery());
    // normally, this would have looked like...
    // var results = _myDbContext.DbObjects.Where(x => foo).ToList();

    // perform business logic
    // ...    
  }
}

Do you start to see the benefit of this approach? Not only are you explicitly encapsulating all EF-related code into descriptive classes, you are allowing extensibility by removing the implementation concern of "how" this request is handled--this class doesn't care if the relevant objects come from EF, MongoDB, or a text file.

Now for the request and handler, via MediatR:

public class GetRelevantDbObjectsQuery : IRequest<DbObject[]> {
  // no input needed for this particular request,
  // but you would simply add plain properties here if needed
}

public class GetRelevantDbObjectsEFQueryHandler : IRequestHandler<GetRelevantDbObjectsQuery, DbObject[]> {
  private readonly IDbContext _db;

  public GetRelevantDbObjectsEFQueryHandler(IDbContext db) {
    _db = db;
  }

  public DbObject[] Handle(GetRelevantDbObjectsQuery message) {
    return _db.DbObjects.Where(foo => bar).ToList();
  }
}

As you can see, the abstraction is simple and encapsulated. It's also absolutely testable because in an integration test, you could test this class individually--there are no business concerns mixed in here.

So what does a unit test of our feature service look like? It's way simple. In this case, I'm using Moq to do mocking (use whatever makes you happy):

[TestClass]
public class FeatureServiceTests {

  // mock of Mediator to handle request/responses
  private Mock<IMediator> _mediator;

  // subject under test
  private FeatureService _sut;

  [TestInitialize]
  public void Setup() {

    // set up Mediator mock
    _mediator = new Mock<IMediator>(MockBehavior.Strict);

    // inject mock as dependency
    _sut = new FeatureService(_mediator.Object);
  }

  [TestCleanup]
  public void Teardown() {

    // ensure we have called or expected all calls to Mediator
    _mediator.VerifyAll();
  }

  [TestMethod]
  public void ComplexBusinessLogic_Does_What_I_Expect() {
    var dbObjects = new List<DbObject>() {
      // set up any test objects
      new DbObject() { }
    };

    // arrange

    // setup Mediator to return our fake objects when it receives a message to perform our query
    // in practice, I find it better to create an extension method that encapsulates this setup here
    _mediator.Setup(x => x.Send(It.IsAny<GetRelevantDbObjectsQuery>(), default(CancellationToken)).ReturnsAsync(dbObjects.ToArray()).Callback(
    (GetRelevantDbObjectsQuery message, CancellationToken token) => {
       // using Moq Callback functionality, you can make assertions
       // on expected request being passed in
       Assert.IsNotNull(message);
    });

    // act
    _sut.ComplexBusinessLogic();

    // assertions
  }

}

You can see all we need is a single setup and we don't even need to configure anything extra--it's a very simple unit test. Let's be clear: This is totally possible to do without something like Mediatr (you would simply implement an interface and mock it for tests, e.g. IGetRelevantDbObjectsQuery), but in practice for a large codebase with many features and queries/commands, I love the encapsulation and innate DI support Mediatr offers.

If you're wondering how I organize these classes, it's pretty simple:

- MyProject
  - Features
    - MyFeature
      - Queries
      - Commands
      - Services
      - DependencyConfig.cs (Ninject feature modules)

Organizing by feature slices is beside the point, but this keeps all relevant/dependent code together and easily discoverable. Most importantly, I separate the Queries vs. Commands--following the Command/Query Separation principle.

This meets all my criteria: it's low-ceremony, it's easy to understand, and there are extra hidden benefits. For example, how do you handle saving changes? Now you can simplify your Db Context by using a role interface (IUnitOfWork.SaveChangesAsync()) and mock calls to the single role interface or you could encapsulate committing/rolling back inside your RequestHandlers--however you prefer to do it is up to you, as long as it's maintainable. For example, I was tempted to create a single generic request/handler where you'd just pass an EF object and it would save/update/remove it--but you have to ask what your intention is and remember that if you wanted to swap out the handler with another storage provider/implementation, you should probably create explicit commands/queries that represent what you intend to do. More often than not, a single service or feature will need something specific--don't create generic stuff before you have a need for it.

There are of course caveats to this pattern--you can go too far with a simple pub/sub mechanism. I've limited my implementation to only abstracting EF-related code, but adventurous developers could start using MediatR to go overboard and message-ize everything--something good code review practices and peer reviews should catch. That's a process issue, not an issue with MediatR, so just be cognizant of how you're using this pattern.

You wanted a concrete example of how people are unit testing/mocking EF and this is an approach that's working successfully for us on our project--and the team is super happy with how easy it is to adopt. I hope this helps! As with all things in programming, there are multiple approaches and it all depends on what you want to achieve. I value simplicity, ease of use, maintainability, and discoverability--and this solution meets all those demands.

Get size of an Iterable in Java

I would go for it.next() for the simple reason that next() is guaranteed to be implemented, while remove() is an optional operation.

E next()

Returns the next element in the iteration.

void remove()

Removes from the underlying collection the last element returned by the iterator (optional operation).

How does HTTP file upload work?

Send file as binary content (upload without form or FormData)

In the given answers/examples the file is (most likely) uploaded with a HTML form or using the FormData API. The file is only a part of the data sent in the request, hence the multipart/form-data Content-Type header.

If you want to send the file as the only content then you can directly add it as the request body and you set the Content-Type header to the MIME type of the file you are sending. The file name can be added in the Content-Disposition header. You can upload like this:

var xmlHttpRequest = new XMLHttpRequest();

var file = ...file handle...
var fileName = ...file name...
var target = ...target...
var mimeType = ...mime type...

xmlHttpRequest.open('POST', target, true);
xmlHttpRequest.setRequestHeader('Content-Type', mimeType);
xmlHttpRequest.setRequestHeader('Content-Disposition', 'attachment; filename="' + fileName + '"');
xmlHttpRequest.send(file);

If you don't (want to) use forms and you are only interested in uploading one single file this is the easiest way to include your file in the request.

How to set the component size with GridLayout? Is there a better way?

An alternative to other layouts, might be to put your panel with the GridLayout, inside another panel that is a FlowLayout. That way your spacing will be intact but will not expand across the entire available space.

Disable browser cache for entire ASP.NET website

You can try below code in Global.asax file.

protected void Application_BeginRequest()
    {
        Response.Cache.SetCacheability(HttpCacheability.NoCache);
        Response.Cache.SetExpires(DateTime.UtcNow.AddHours(-1));
        Response.Cache.SetNoStore();
    }

How to count the number of occurrences of a character in an Oracle varchar value?

SELECT {FN LENGTH('123-345-566')} - {FN LENGTH({FN REPLACE('123-345-566', '#', '')})} FROM DUAL

Get integer value of the current year in Java

In Java version 8+ can (advised to) use java.time library. ISO 8601 sets standard way to write dates: YYYY-MM-DD and java.time.Instant uses it, so (for UTC):

import java.time.Instant;
int myYear = Integer.parseInt(Instant.now().toString().substring(0,4));

P.S. just in case (and shorted for getting String, not int), using Calendar looks better and can be made zone-aware.

Difference between binary semaphore and mutex

Mutexes have ownership, unlike semaphores. Although any thread, within the scope of a mutex, can get an unlocked mutex and lock access to the same critical section of code,only the thread that locked a mutex should unlock it.

Setting timezone to UTC (0) in PHP

In PHP DateTime (PHP >= 5.3)

$dt = new DateTime();
$dt->setTimezone(new DateTimeZone('UTC'));
echo $dt->getTimestamp();

How can I check if a command exists in a shell script?

Check if a program exists from a Bash script covers this very well. In any shell script, you're best off running command -v $command_name for testing if $command_name can be run. In bash you can use hash $command_name, which also hashes the result of any path lookup, or type -P $binary_name if you only want to see binaries (not functions etc.)

What version of Python is on my Mac?

Use below command to see all python installations :

which -a python

ALTER TABLE, set null in not null column, PostgreSQL 9.1

First, Set :
ALTER TABLE person ALTER COLUMN phone DROP NOT NULL;

Bash integer comparison

I know this has been answered, but here's mine just because I think case is an under-appreciated tool. (Maybe because people think it is slow, but it's at least as fast as an if, sometimes faster.)

case "$1" in
    0|1) xinput set-prop 12 "Device Enabled" $1 ;;
      *) echo "This script requires a 1 or 0 as first parameter." ;;
esac

How to get a particular date format ('dd-MMM-yyyy') in SELECT query SQL Server 2008 R2

select CONVERT(NVARCHAR, SYSDATETIME(), 106) AS [DD-MON-YYYY]

or else

select REPLACE(CONVERT(NVARCHAR,GETDATE(), 106), ' ', '-')

both works fine

How to execute 16-bit installer on 64-bit Win7?

I posted some information on the Infragistics forums for designer widgets that may help you for this. You can view the post with the following link:
http://forums.infragistics.com/forums/p/52530/320151.aspx#320151

Note that the registry keys would be different for the different product and you may need to install on a 32 bit machine to see what keys you need.

Log all requests from the python-requests module

For those using python 3+

import requests
import logging
import http.client

http.client.HTTPConnection.debuglevel = 1

logging.basicConfig()
logging.getLogger().setLevel(logging.DEBUG)
requests_log = logging.getLogger("requests.packages.urllib3")
requests_log.setLevel(logging.DEBUG)
requests_log.propagate = True

Visual Studio : short cut Key : Duplicate Line

The command you want is Edit.Duplicate. It is mapped to CtrlE, CtrlV. This will not overwrite your clipboard.

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

Another option would be using flexbox.

While it's not supported by IE8 and IE9, you could consider:

  • Not minding about those old IE versions
  • Providing a fallback
  • Using a polyfill

Despite some additional browser-specific style prefixing would be necessary for full cross-browser support, you can see the basic usage either on this fiddle and on the following snippet:

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

How to check if array is empty or does not exist?

You want to do the check for undefined first. If you do it the other way round, it will generate an error if the array is undefined.

if (array === undefined || array.length == 0) {
    // array empty or does not exist
}

Update

This answer is getting a fair amount of attention, so I'd like to point out that my original answer, more than anything else, addressed the wrong order of the conditions being evaluated in the question. In this sense, it fails to address several scenarios, such as null values, other types of objects with a length property, etc. It is also not very idiomatic JavaScript.

The foolproof approach
Taking some inspiration from the comments, below is what I currently consider to be the foolproof way to check whether an array is empty or does not exist. It also takes into account that the variable might not refer to an array, but to some other type of object with a length property.

if (!Array.isArray(array) || !array.length) {
  // array does not exist, is not an array, or is empty
  // ? do not attempt to process array
}

To break it down:

  1. Array.isArray(), unsurprisingly, checks whether its argument is an array. This weeds out values like null, undefined and anything else that is not an array.
    Note that this will also eliminate array-like objects, such as the arguments object and DOM NodeList objects. Depending on your situation, this might not be the behavior you're after.

  2. The array.length condition checks whether the variable's length property evaluates to a truthy value. Because the previous condition already established that we are indeed dealing with an array, more strict comparisons like array.length != 0 or array.length !== 0 are not required here.

The pragmatic approach
In a lot of cases, the above might seem like overkill. Maybe you're using a higher order language like TypeScript that does most of the type-checking for you at compile-time, or you really don't care whether the object is actually an array, or just array-like.

In those cases, I tend to go for the following, more idiomatic JavaScript:

if (!array || !array.length) {
    // array or array.length are falsy
    // ? do not attempt to process array
}

Or, more frequently, its inverse:

if (array && array.length) {
    // array and array.length are truthy
    // ? probably OK to process array
}

With the introduction of the optional chaining operator (Elvis operator) in ECMAScript 2020, this can be shortened even further:

if (!array?.length) {
    // array or array.length are falsy
    // ? do not attempt to process array
}

Or the opposite:

if (array?.length) {
    // array and array.length are truthy
    // ? probably OK to process array
}

Java: how do I get a class literal from a generic type?

You could use a helper method to get rid of @SuppressWarnings("unchecked") all over a class.

@SuppressWarnings("unchecked")
private static <T> Class<T> generify(Class<?> cls) {
    return (Class<T>)cls;
}

Then you could write

Class<List<Foo>> cls = generify(List.class);

Other usage examples are

  Class<Map<String, Integer>> cls;

  cls = generify(Map.class);

  cls = TheClass.<Map<String, Integer>>generify(Map.class);

  funWithTypeParam(generify(Map.class));

public void funWithTypeParam(Class<Map<String, Integer>> cls) {
}

However, since it is rarely really useful, and the usage of the method defeats the compiler's type checking, I would not recommend to implement it in a place where it is publicly accessible.

What exactly is an instance in Java?

An object and an instance are the same thing.

Personally I prefer to use the word "instance" when referring to a specific object of a specific type, for example "an instance of type Foo". But when talking about objects in general I would say "objects" rather than "instances".

A reference either refers to a specific object or else it can be a null reference.


They say that they have to create an instance to their application. What does it mean?

They probably mean you have to write something like this:

Foo foo = new Foo();

If you are unsure what type you should instantiate you should contact the developers of the application and ask for a more complete example.

How to activate "Share" button in android app?

Create a button with an id share and add the following code snippet.

share.setOnClickListener(new View.OnClickListener() {             
    @Override
    public void onClick(View v) {

        Intent sharingIntent = new Intent(android.content.Intent.ACTION_SEND);
        sharingIntent.setType("text/plain");
        String shareBody = "Your body here";
        String shareSub = "Your subject here";
        sharingIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, shareSub);
        sharingIntent.putExtra(android.content.Intent.EXTRA_TEXT, shareBody);
        startActivity(Intent.createChooser(sharingIntent, "Share using"));
    }
});

The above code snippet will open the share chooser on share button click action. However, note...The share code snippet might not output very good results using emulator. For actual results, run the code snippet on android device to get the real results.

Excel - find cell with same value in another worksheet and enter the value to the left of it

The easiest way is probably with VLOOKUP(). This will require the 2nd worksheet to have the employee number column sorted though. In newer versions of Excel, apparently sorting is no longer required.

For example, if you had a "Sheet2" with two columns - A = the employee number, B = the employee's name, and your current worksheet had employee numbers in column D and you want to fill in column E, in cell E2, you would have:

=VLOOKUP($D2, Sheet2!$A$2:$B$65535, 2, FALSE)

Then simply fill this formula down the rest of column D.

Explanation:

  • The first argument $D2 specifies the value to search for.
  • The second argument Sheet2!$A$2:$B$65535 specifies the range of cells to search in. Excel will search for the value in the first column of this range (in this case Sheet2!A2:A65535). Note I am assuming you have a header cell in row 1.
  • The third argument 2 specifies a 1-based index of the column to return from within the searched range. The value of 2 will return the second column in the range Sheet2!$A$2:$B$65535, namely the value of the B column.
  • The fourth argument FALSE says to only return exact matches.

Overriding a JavaScript function while referencing the original

The examples above don't correctly apply this or pass arguments correctly to the function override. Underscore _.wrap() wraps existing functions, applies this and passes arguments correctly. See: http://underscorejs.org/#wrap

How to improve performance of ngRepeat over a huge dataset (angular.js)?

I agree with @AndreM96 that the best approach is to display only a limited amount of rows, faster and better UX, this could be done with a pagination or with an infinite scroll.

Infinite scroll with Angular is really simple with limitTo filter. You just have to set the initial limit and when the user asks for more data (I am using a button for simplicity) you increment the limit.

<table>
    <tr ng-repeat="d in data | limitTo:totalDisplayed"><td>{{d}}</td></tr>
</table>
<button class="btn" ng-click="loadMore()">Load more</button>

//the controller
$scope.totalDisplayed = 20;

$scope.loadMore = function () {
  $scope.totalDisplayed += 20;  
};

$scope.data = data;

Here is a JsBin.

This approach could be a problem for phones because usually they lag when scrolling a lot of data, so in this case I think a pagination fits better.

To do it you will need the limitTo filter and also a custom filter to define the starting point of the data being displayed.

Here is a JSBin with a pagination.

What to return if Spring MVC controller method doesn't return value?

Here is example code what I did for an asynchronous method

@RequestMapping(value = "/import", method = RequestMethod.POST)
@ResponseStatus(value = HttpStatus.OK)
public void importDataFromFile(@RequestParam("file") MultipartFile file) 
{
    accountingSystemHandler.importData(file, assignChargeCodes);
}

You do not need to return any thing from your method all you need to use this annotation so that your method should return OK in every case

@ResponseStatus(value = HttpStatus.OK)

Convert to Datetime MM/dd/yyyy HH:mm:ss in Sql Server

Supported by SQL Server 2005 and later versions

SELECT CONVERT(VARCHAR(10), GETDATE(), 101) 
       + ' ' + CONVERT(VARCHAR(8), GETDATE(), 108)

* See Microsoft's documentation to understand what the 101 and 108 style codes above mean.

Supported by SQL Server 2012 and later versions

SELECT FORMAT(GETDATE() , 'MM/dd/yyyy HH:mm:ss')

Result

Both of the above methods will return:

10/16/2013 17:00:20

RestClientException: Could not extract response. no suitable HttpMessageConverter found

I was trying to use Feign, while I encounter same issue, As I understood HTTP message converter will help but wanted to understand how to achieve this.

@FeignClient(name = "mobilesearch", url = "${mobile.search.uri}" ,
        fallbackFactory = MobileSearchFallbackFactory.class,
        configuration = MobileSearchFeignConfig.class)
public interface MobileSearchClient {

    @RequestMapping(method = RequestMethod.GET)
    List<MobileSearchResponse> getPhones();
}

You have to use Customer Configuration for the decoder, MobileSearchFeignConfig,

public class MobileSearchFeignConfig {

    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }


    @Bean
    public Decoder feignDecoder() {
        return new ResponseEntityDecoder(new SpringDecoder(feignHttpMessageConverter()));
    }

    public ObjectFactory<HttpMessageConverters> feignHttpMessageConverter() {
        final HttpMessageConverters httpMessageConverters = new HttpMessageConverters(new MappingJackson2HttpMessageConverter());
        return new ObjectFactory<HttpMessageConverters>() {
            @Override
            public HttpMessageConverters getObject() throws BeansException {
                return httpMessageConverters;
            }
        };
    }

    public class MappingJackson2HttpMessageConverter extends org.springframework.http.converter.json.MappingJackson2HttpMessageConverter {
        MappingJackson2HttpMessageConverter() {
            List<MediaType> mediaTypes = new ArrayList<>();
            mediaTypes.add(MediaType.valueOf(MediaType.TEXT_HTML_VALUE + ";charset=UTF-8"));
            setSupportedMediaTypes(mediaTypes);
        }
    }

}

pthread_join() and pthread_exit()

In pthread_exit, ret is an input parameter. You are simply passing the address of a variable to the function.

In pthread_join, ret is an output parameter. You get back a value from the function. Such value can, for example, be set to NULL.

Long explanation:

In pthread_join, you get back the address passed to pthread_exit by the finished thread. If you pass just a plain pointer, it is passed by value so you can't change where it is pointing to. To be able to change the value of the pointer passed to pthread_join, it must be passed as a pointer itself, that is, a pointer to a pointer.

Modulo operator with negative values

The sign in such cases (i.e when one or both operands are negative) is implementation-defined. The spec says in §5.6/4 (C++03),

The binary / operator yields the quotient, and the binary % operator yields the remainder from the division of the first expression by the second. If the second operand of / or % is zero the behavior is undefined; otherwise (a/b)*b + a%b is equal to a. If both operands are nonnegative then the remainder is nonnegative; if not, the sign of the remainder is implementation-defined.

That is all the language has to say, as far as C++03 is concerned.

Redirect stderr and stdout in Bash

LOG_FACILITY="local7.notice"
LOG_TOPIC="my-prog-name"
LOG_TOPIC_OUT="$LOG_TOPIC-out[$$]"
LOG_TOPIC_ERR="$LOG_TOPIC-err[$$]"

exec 3>&1 > >(tee -a /dev/fd/3 | logger -p "$LOG_FACILITY" -t "$LOG_TOPIC_OUT" )
exec 2> >(logger -p "$LOG_FACILITY" -t "$LOG_TOPIC_ERR" )

It is related: Writing stdOut & stderr to syslog.

It almost work, but not from xinted ;(

How to check if a table exists in a given schema

For PostgreSQL 9.3 or less...Or who likes all normalized to text

Three flavors of my old SwissKnife library: relname_exists(anyThing), relname_normalized(anyThing) and relnamechecked_to_array(anyThing). All checks from pg_catalog.pg_class table, and returns standard universal datatypes (boolean, text or text[]).

/**
 * From my old SwissKnife Lib to your SwissKnife. License CC0.
 * Check and normalize to array the free-parameter relation-name.
 * Options: (name); (name,schema), ("schema.name"). Ignores schema2 in ("schema.name",schema2).
 */
CREATE FUNCTION relname_to_array(text,text default NULL) RETURNS text[] AS $f$
     SELECT array[n.nspname::text, c.relname::text]
     FROM   pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace,
            regexp_split_to_array($1,'\.') t(x) -- not work with quoted names
     WHERE  CASE
              WHEN COALESCE(x[2],'')>'' THEN n.nspname = x[1]      AND c.relname = x[2]
              WHEN $2 IS NULL THEN           n.nspname = 'public'  AND c.relname = $1
              ELSE                           n.nspname = $2        AND c.relname = $1
            END
$f$ language SQL IMMUTABLE;

CREATE FUNCTION relname_exists(text,text default NULL) RETURNS boolean AS $wrap$
  SELECT EXISTS (SELECT relname_to_array($1,$2))
$wrap$ language SQL IMMUTABLE;

CREATE FUNCTION relname_normalized(text,text default NULL,boolean DEFAULT true) RETURNS text AS $wrap$
  SELECT COALESCE(array_to_string(relname_to_array($1,$2), '.'), CASE WHEN $3 THEN '' ELSE NULL END)
$wrap$ language SQL IMMUTABLE;

Select2() is not a function

For newbies like me, who end up on this question: This error also happens if you attempt to call .select2() on an element retrieved using pure javascript and not using jQuery.

This fails with the "select2 is not a function" error:

document.getElementById('e9').select2();

This works:

$("#e9").select2();

Pass a password to ssh in pure bash

You can not specify the password from the command line but you can do either using ssh keys or using sshpass as suggested by John C. or using a expect script.

To use sshpass, you need to install it first. Then

sshpass -f <(printf '%s\n' your_password) ssh user@hostname

instead of using sshpass -p your_password. As mentioned by Charles Duffy in the comments, it is safer to supply the password from a file or from a variable instead of from command line.

BTW, a little explanation for the <(command) syntax. The shell executes the command inside the parentheses and replaces the whole thing with a file descriptor, which is connected to the command's stdout. You can find more from this answer https://unix.stackexchange.com/questions/156084/why-does-process-substitution-result-in-a-file-called-dev-fd-63-which-is-a-pipe

SQL Developer with JDK (64 bit) cannot find JVM

Create directory "bin" in

D:\sqldeveloper\jdk\ Copy

msvcr100.dll from

D:\sqldeveloper\jdk\jre\bin to

D:\sqldeveloper\jdk\bin

Using JAXB to unmarshal/marshal a List<String>

Finally I've solved it using JacksonJaxbJsonProvider It requires few changes in your Spring context.xml and Maven pom.xml

In your Spring context.xml add JacksonJaxbJsonProvider to the <jaxrs:server>:

<jaxrs:server id="restService" address="/resource">
    <jaxrs:providers>
        <bean class="org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider"/>
    </jaxrs:providers>
</jaxrs:server>

In your Maven pom.xml add:

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-jaxrs</artifactId>
    <version>1.9.0</version>
</dependency>

Entity Framework Queryable async

The problem seems to be that you have misunderstood how async/await work with Entity Framework.

About Entity Framework

So, let's look at this code:

public IQueryable<URL> GetAllUrls()
{
    return context.Urls.AsQueryable();
}

and example of it usage:

repo.GetAllUrls().Where(u => <condition>).Take(10).ToList()

What happens there?

  1. We are getting IQueryable object (not accessing database yet) using repo.GetAllUrls()
  2. We create a new IQueryable object with specified condition using .Where(u => <condition>
  3. We create a new IQueryable object with specified paging limit using .Take(10)
  4. We retrieve results from database using .ToList(). Our IQueryable object is compiled to sql (like select top 10 * from Urls where <condition>). And database can use indexes, sql server send you only 10 objects from your database (not all billion urls stored in database)

Okay, let's look at first code:

public async Task<IQueryable<URL>> GetAllUrlsAsync()
{
    var urls = await context.Urls.ToListAsync();
    return urls.AsQueryable();
}

With the same example of usage we got:

  1. We are loading in memory all billion urls stored in your database using await context.Urls.ToListAsync();.
  2. We got memory overflow. Right way to kill your server

About async/await

Why async/await is preferred to use? Let's look at this code:

var stuff1 = repo.GetStuff1ForUser(userId);
var stuff2 = repo.GetStuff2ForUser(userId);
return View(new Model(stuff1, stuff2));

What happens here?

  1. Starting on line 1 var stuff1 = ...
  2. We send request to sql server that we want to get some stuff1 for userId
  3. We wait (current thread is blocked)
  4. We wait (current thread is blocked)
  5. .....
  6. Sql server send to us response
  7. We move to line 2 var stuff2 = ...
  8. We send request to sql server that we want to get some stuff2 for userId
  9. We wait (current thread is blocked)
  10. And again
  11. .....
  12. Sql server send to us response
  13. We render view

So let's look to an async version of it:

var stuff1Task = repo.GetStuff1ForUserAsync(userId);
var stuff2Task = repo.GetStuff2ForUserAsync(userId);
await Task.WhenAll(stuff1Task, stuff2Task);
return View(new Model(stuff1Task.Result, stuff2Task.Result));

What happens here?

  1. We send request to sql server to get stuff1 (line 1)
  2. We send request to sql server to get stuff2 (line 2)
  3. We wait for responses from sql server, but current thread isn't blocked, he can handle queries from another users
  4. We render view

Right way to do it

So good code here:

using System.Data.Entity;

public IQueryable<URL> GetAllUrls()
{
   return context.Urls.AsQueryable();
}

public async Task<List<URL>> GetAllUrlsByUser(int userId) {
   return await GetAllUrls().Where(u => u.User.Id == userId).ToListAsync();
}

Note, than you must add using System.Data.Entity in order to use method ToListAsync() for IQueryable.

Note, that if you don't need filtering and paging and stuff, you don't need to work with IQueryable. You can just use await context.Urls.ToListAsync() and work with materialized List<Url>.

Clearing all cookies with JavaScript

You can get a list by looking into the document.cookie variable. Clearing them all is just a matter of looping over all of them and clearing them one by one.

What is an ORM, how does it work, and how should I use one?

Like all acronyms it's ambiguous, but I assume they mean object-relational mapper -- a way to cover your eyes and make believe there's no SQL underneath, but rather it's all objects;-). Not really true, of course, and not without problems -- the always colorful Jeff Atwood has described ORM as the Vietnam of CS;-). But, if you know little or no SQL, and have a pretty simple / small-scale problem, they can save you time!-)

Downloading images with node.js

You can use Axios (a promise-based HTTP client for Node.js) to download images in the order of your choosing in an asynchronous environment:

npm i axios

Then, you can use the following basic example to begin downloading images:

const fs = require('fs');
const axios = require('axios');

/* ============================================================
  Function: Download Image
============================================================ */

const download_image = (url, image_path) =>
  axios({
    url,
    responseType: 'stream',
  }).then(
    response =>
      new Promise((resolve, reject) => {
        response.data
          .pipe(fs.createWriteStream(image_path))
          .on('finish', () => resolve())
          .on('error', e => reject(e));
      }),
  );

/* ============================================================
  Download Images in Order
============================================================ */

(async () => {
  let example_image_1 = await download_image('https://example.com/test-1.png', 'example-1.png');

  console.log(example_image_1.status); // true
  console.log(example_image_1.error); // ''

  let example_image_2 = await download_image('https://example.com/does-not-exist.png', 'example-2.png');

  console.log(example_image_2.status); // false
  console.log(example_image_2.error); // 'Error: Request failed with status code 404'

  let example_image_3 = await download_image('https://example.com/test-3.png', 'example-3.png');

  console.log(example_image_3.status); // true
  console.log(example_image_3.error); // ''
})();

How to center content in a bootstrap column?

Bootstrap naming conventions carry styles of their own, col-XS-1 refers to a column being 8.33% of the containing element wide. Your text, would most likely expand far beyond the specified width, and couldn't possible be centered within it. If you wanted it to constrain to the div, you could use something like css word-break.

For centering the content within an element large enough to expand beyond the text, you have two options.

Option 1: HTML Center Tag

<div class="row">
  <div class="col-xs-1 center-block">
    <center>
      <span>aaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
    </center>
  </div>
</div>

Option 2: CSS Text-Align

<div class="row">
  <div class="col-xs-1 center-block" style="text-align:center;">
    <span>aaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
  </div>
</div>

If you wanted everything to constrain to the width of the column

<div class="row">
  <div class="col-xs-1 center-block" style="text-align:center;word-break:break-all;">
    <span>aaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
  </div>
</div>

UPDATE - Using Bootstrap's text-center class

<div class="row">
  <div class="col-xs-1 center-block text-center">
    <span>aaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
  </div>
</div>

FlexBox Method

<div class="row">
  <div class="flexBox" style="
    display: flex;
    flex-flow: row wrap;
    justify-content: center;">
    <span>aaaaaaaaaaaaaaaaaaaaaaaaaaa</span>
  </div>
</div>

http://jsfiddle.net/usth0kd2/13/

How to exclude particular class name in CSS selector?

In modern browsers you can do:

.reMode_hover:not(.reMode_selected):hover{}

Consult http://caniuse.com/css-sel3 for compatibility information.

How do you post to the wall on a facebook page (not profile)

Get PHP SDK from github and run the following code:

<?php
$attachment = array(
    'message' => 'this is my message',
    'name' => 'This is my demo Facebook application!',
    'caption' => "Caption of the Post",
    'link' => 'http://mylink.com',
    'description' => 'this is a description',
    'picture' => 'http://mysite.com/pic.gif',
    'actions' => array(
        array(
            'name' => 'Get Search',
            'link' => 'http://www.google.com'
        )
    )
);

$result = $facebook->api('/me/feed/', 'post', $attachment);

the above code will Post the message on to your wall... and if you want to post onto your friends or others wall then replace me with the Facebook User Id of that user..for further information look out the API Documentation.

What is the difference between Python and IPython?

From my experience I've found that some commands which run in IPython do not run in base Python. For example, pwd and ls don't work alone in base Python. However they will work if prefaced with a % such as: %pwd and %ls.

Also, in IPython, you can run the cd command like: cd C:\Users\... This doesn't seem to work in base python, even when prefaced with a % however.

Visual Studio 2015 Update 3 Offline Installer (ISO)

[UPDATE]
As per March 7, 2017, Visual Studio 2017 was released for general availability.

You can refer to Mehdi Dehghani answer for the direct download links or the old-fashioned ways using the website, vibs2006 answer
And you can also combine it with ray pixar answer to make it a complete full standalone offline installer.


Note:
I don't condone any illegal use of the offline installer.
Please stop piracy and follow the EULA.

The community edition is free even for commercial use, under some condition.
You can see the EULA in this link below.
https://www.visualstudio.com/support/legal/mt171547
Thank you.


Instruction for official offline installer:

  1. Open this link

    https://www.visualstudio.com/downloads/

  2. Scroll Down (DO NOT FORGET!)

  3. Click on "Visual Studio 2015" panel heading
  4. Choose the edition that you want

    These menu should be available in that panel:

    • Community 2015
    • Enterprise 2015
    • Professional 2015
    • Enterprise 2015
    • Visual Studio 2015 Update
    • Visual Studio 2015 Language Pack
    • Visual Studio Test Professional 2015 Language Pack
    • Test Professional 2015
    • Express 2015 for Desktop
    • Express 2015 for Windows 10


  1. Choose the language that you want in the drop-down menu (above the Download button)

    The language drop-down menu should be like this:

    • English for English
    • Deutsch for German
    • Español for Spanish
    • Français for French
    • Italiano for Italian
    • ??????? for Russian
    • ??? for Japanese
    • ???? for Chinese (Simplified)
    • ???? for Chinese (Traditional)
    • ??? for Korean


  1. Check on "ISO" in radio-button menu (on the left side of the Download button)

    The radio-button menu should be like this:

    • Web installer
    • ISO
  2. Click the Download button

Regular expression: zero or more occurrences of optional character /

/*

If your delimiters are slash-based, escape it:

\/*

* means "0 or more of the previous repeatable pattern", which can be a single character, a character class or a group.

How does Spring autowire by name when more than one matching bean is found?

One more solution with resolving by name:

@Resource(name="country")

It uses javax.annotation package, so it's not Spring specific, but Spring supports it.

How to kill a process in MacOS?

I have experienced that if kill -9 PID doesn't work and you own the process, you can use kill -s kill PID which is kind of surprising as the man page says you can kill -signal_number PID.

Request header field Access-Control-Allow-Headers is not allowed by Access-Control-Allow-Headers

If anyone experiences this problem with an express server, add the following middleware

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
  next();
});

How to display tables on mobile using Bootstrap?

Bootstrap 3 introduces responsive tables:

<div class="table-responsive">
  <table class="table">
    ...
  </table>
</div>

Bootstrap 4 is similar, but with more control via some new classes:

...responsive across all viewports ... with .table-responsive. Or, pick a maximum breakpoint with which to have a responsive table up to by using .table-responsive{-sm|-md|-lg|-xl}.

Credit to Jason Bradley for providing an example:

Responsive Tables

How to Check byte array empty or not?

In Android Studio version 3.4.1

if(Attachment != null)
{
   code here ...
}

Why does overflow:hidden not work in a <td>?

Well here is a solution for you but I don't really understand why it works:

<html><body>
  <div style="width: 200px; border: 1px solid red;">Test</div>
  <div style="width: 200px; border: 1px solid blue; overflow: hidden; height: 1.5em;">My hovercraft is full of eels.  These pretzels are making me thirsty.</div>
  <div style="width: 200px; border: 1px solid yellow; overflow: hidden; height: 1.5em;">
  This_is_a_terrible_example_of_thinking_outside_the_box.
  </div>
  <table style="border: 2px solid black; border-collapse: collapse; width: 200px;"><tr>
   <td style="width:200px; border: 1px solid green; overflow: hidden; height: 1.5em;"><div style="width: 200px; border: 1px solid yellow; overflow: hidden;">
    This_is_a_terrible_example_of_thinking_outside_the_box.
   </div></td>
  </tr></table>
</body></html>

Namely, wrapping the cell contents in a div.

jQuery select child element by class with unknown path

Try this

$('#thisElement .classToSelect').each(function(i){
         // do stuff
});

Hope it will help

Root user/sudo equivalent in Cygwin?

Use this to get an admin window with either bash or cmd running, from any directories context menue. Just right click on a directory name, and select the entry or hit the highlited button.

This is based on the chere tool and the unfortunately not working answer (for me) from link_boy. It works fine for me using Windows 8,

A side effect is the different color in the admin cmd window. To use this on bash, you can change the .bashrc file of the admin user.

I coudln't get the "background" version (right click into an open directory) to run. Feel free to add it.

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash]
@="&Bash Prompt Here"
"Icon"="C:\\cygwin\\Cygwin.ico"

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash\command]
@="C:\\cygwin\\bin\\bash -c \"/bin/xhere /bin/bash.exe '%L'\""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash_root]
@="&Root Bash Prompt Here"
"Icon"="C:\\cygwin\\Cygwin.ico"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_bash_root\command]
@="runas /savecred /user:administrator \"C:\\cygwin\\bin\\bash -c \\\"/bin/xhere /bin/bash.exe '%L'\\\"\""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_cmd]
@="&Command Prompt Here"

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_cmd\command]
@="cmd.exe /k cd %L"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_cmd_root]
@="Roo&t Command Prompt Here"
"HasLUAShield"=""

[HKEY_CLASSES_ROOT\Directory\shell\cygwin_cmd_root\command]
@="runas /savecred /user:administrator \"cmd.exe /t:1E /k cd %L\""

angular2 submit form by pressing enter without submit button

add this inside your input tag

<input type="text" (keyup.enter)="yourMethod()" />

How to calculate an angle from three points?

well, the other answers seem to cover everything required, so I would like to just add this if you are using JMonkeyEngine:

Vector3f.angleBetween(otherVector)

as that is what I came here looking for :)

How to output a comma delimited list in jinja python template?

And using the joiner from http://jinja.pocoo.org/docs/dev/templates/#joiner

{% set comma = joiner(",") %}
{% for user in userlist %}
    {{ comma() }}<a href="/profile/{{ user }}/">{{ user }}</a>
{% endfor %}  

It's made for this exact purpose. Normally a join or a check of forloop.last would suffice for a single list, but for multiple groups of things it's useful.

A more complex example on why you would use it.

{% set pipe = joiner("|") %}
{% if categories %} {{ pipe() }}
    Categories: {{ categories|join(", ") }}
{% endif %}
{% if author %} {{ pipe() }}
    Author: {{ author() }}
{% endif %}
{% if can_edit %} {{ pipe() }}
    <a href="?action=edit">Edit</a>
{% endif %}

Sorting dropdown alphabetically in AngularJS

var module = angular.module("example", []);

module.controller("orderByController", function ($scope) {
    $scope.orderByValue = function (value) {
        return value;
    };

    $scope.items = ["c", "b", "a"];
    $scope.objList = [
        {
            "name": "c"
        }, {
            "name": "b"
        }, {
            "name": "a"
        }];
        $scope.item = "b";
    });

http://jsfiddle.net/Nfv42/65/

UTL_FILE.FOPEN() procedure not accepting path for directory?

Don't forget also that the path for the file is on the actual oracle server machine and not any local development machine that might be calling your stored procedure. This is probably very obvious but something that should be remembered.

How can I make an "are you sure" prompt in a Windows batchfile?

You can consider using a UI confirmation.

With yesnopopup.bat

@echo off

for /f "tokens=* delims=" %%# in ('yesnopopup.bat') do (
    set "result=%%#"
)

if /i result==no (
    echo user rejected the script
    exit /b 1
) 

echo continue

rem --- other commands --

the user will see the following and depending on the choice the script will continue:

enter image description here

with absolutely the same script you can use also iexpYNbutton.bat which will produce similar popup.

With buttons.bat you can try the following script:

@echo off

for /f "tokens=* delims=" %%# in ('buttons.bat "Yep!" "Nope!" ') do (
    set "result=%%#"
)

if /i result==2 (
    echo user rejected the script
    exit /b 1
) 

echo continue

rem --- other commands --

and the user will see:

enter image description here

What's the difference between '$(this)' and 'this'?

When using jQuery, it is advised to use $(this) usually. But if you know (you should learn and know) the difference, sometimes it is more convenient and quicker to use just this. For instance:

$(".myCheckboxes").change(function(){ 
    if(this.checked) 
       alert("checked"); 
});

is easier and purer than

$(".myCheckboxes").change(function(){ 
      if($(this).is(":checked")) 
         alert("checked"); 
});

How to subtract 2 hours from user's local time?

Subtract from another date object

var d = new Date();

d.setHours(d.getHours() - 2);

How does Go update third-party packages?

@tux answer is great, just wanted to add that you can use go get to update a specific package:

go get -u full_package_name

HTML Table cellspacing or padding just top / bottom

Cellspacing is all around the cell and cannot be changed (i.e. if it's set to one, there will be 1 pixel of space on all sides). Padding can be specified discreetly (e.g. padding-top, padding-bottom, padding-left, and padding-right; or padding: [top] [right] [bottom] [left];).

NodeJS: How to get the server's port?

In the current version (v0.5.0-pre) the port seems to be available as a property on the server object, see http://nodejs.org/docs/v0.4.7/api/net.html#server.address

var server = http.createServer(function(req, res) {
    ...
}

server.listen(8088);
console.log(server.address());
console.log(server.address().address);
console.log(server.address().port);

outputs

{ address: '0.0.0.0', port: 8088 }
0.0.0.0
8088

firestore: PERMISSION_DENIED: Missing or insufficient permissions

The above voted answers are dangerous for the health of your database. You can still make your database available just for reading and not for writing:

  service cloud.firestore {
    match /databases/{database}/documents {
     match /{document=**} {
       allow read: if true;
       allow write: if false;
      }
   }
}

I forgot the password I entered during postgres installation

Just a note, on Linux You can simply run sudo su - postgres to become the postgres user and from there change what required using psql.

How does numpy.histogram() work?

Another useful thing to do with numpy.histogram is to plot the output as the x and y coordinates on a linegraph. For example:

arr = np.random.randint(1, 51, 500)
y, x = np.histogram(arr, bins=np.arange(51))
fig, ax = plt.subplots()
ax.plot(x[:-1], y)
fig.show()

enter image description here

This can be a useful way to visualize histograms where you would like a higher level of granularity without bars everywhere. Very useful in image histograms for identifying extreme pixel values.

ASP.NET MVC Return Json Result?

It should be :

public async Task<ActionResult> GetSomeJsonData()
{
    var model = // ... get data or build model etc.

    return Json(new { Data = model }, JsonRequestBehavior.AllowGet); 
}

or more simply:

return Json(model, JsonRequestBehavior.AllowGet); 

I did notice that you are calling GetResources() from another ActionResult which wont work. If you are looking to get JSON back, you should be calling GetResources() from ajax directly...

Batch script to find and replace a string in text file within a minute for files up to 12 MB

How about this?

set search=%1
set replace=%2
set textfile=Input.txt    

python -c "with open('%textfile%', 'rw') as f: f.write(f.read().replace('%search%', '%replace%'))"

Muhahaha

Converting unix time into date-time via excel

TLDR

=(A1/86400)+25569

...and the format of the cell should be date.

If it doesn't work for you

  • If you get a number you forgot to format the output cell as a date.
  • If you get ##### you probably don't have a real Unix time. Check your timestamps in https://www.epochconverter.com/. Try to divide your input by 10, 100, 1000 or 10000**
  • You work with timestamps outside Excel's (very extended) limits.
  • You didn't replace A1 with the cell containing the timestamp ;-p

Explanation

Unix system represent a point in time as a number. Specifically the number of seconds* since a zero-time called the Unix epoch which is 1/1/1970 00:00 UTC/GMT. This number of seconds is called "Unix timestamp" or "Unix time" or "POSIX time" or just "timestamp" and sometimes (confusingly) "Unix epoch".

In the case of Excel they chose a different zero-time and step (because who wouldn't like variety in technical details?). So Excel counts days since 24 hours before 1/1/0000 UTC/GMT. So 25569 corresponds to 1/1/1970 00:00 UTC/GMT and 25570 to 2/1/1970 00:00.

Now please note that we have 86400 seconds per day (24 hours x60 minutes each x60 seconds) and you can understand what this formula does: A1/86400 converts seconds to days and +25569 adjusts for the offset between what is time-zero for Unix and what is time-zero for Excel.

By the way DATE(1970,1,1) will helpfully return 25569 for you in case you forget all this so a more "self-documenting" way to write our formula is:

=A1/(24*60*60) + DATE(1970,1,1)

P.S.: All these were already present in other answers and comments just not laid out as I like them and I don't feel it's OK to edit the hell out of another answer.


*: that's almost correct because you should not count leap seconds

**: E.g. in the case of this question the number was number of milliseconds since the the Unix epoch.

SQL Server error on update command - "A severe error occurred on the current command"

This error is exactly what it means: Something bad happened, that would not normally happen.

In my most recent case, the REAL error was:

Msg 9002, Level 17, State 2, Procedure MyProcedure, Line 2 [Batch Start Line 3]
The transaction log for database 'MyDb' is full due to 'LOG_BACKUP'.

Here is my checklist of things to try, perhaps in this exact order:

  1. Check if you're out of disk space (this was my real problem; our NOC did not catch this)
  2. Check if you're low on memory
  3. Check if the Windows Event Log shows any serious system failures like hard drives failing
  4. Check if you have any unsafe code loaded through extended procedures or SQLCLR unsafe assemblies that could de-stabilize the SQLServer.exe process.
  5. Run CheckDB to see if your database has any corruption issues. On a very large database, if this stored procedure only touches a sub-set of tables, you can save time by seeing which partitions (filegroups) the stored procedure touches, and only checking those specific filegroups.
    1. I would do this for your database and master db as well.

Disabled UIButton not faded or grey

You can use the both first answers and is going to be a better result.

In the attribute inspector (when you're selecting the button), change the State Config to Disabled to set the new Image that is going to appear when it is disabled (remove the marker in the Content->Enabled check to made it disabled).

And when you change the state to enabled, the image will load the one from this state.

Adding the alpha logic to this is a good detail.

How do I exit from the text window in Git?

That's the vi editor. Try ESC :q!.

How do I resolve "Run-time error '429': ActiveX component can't create object"?

You say it works once you install the VB6 IDE so the problem is likely to be that the components you are trying to use depend on the VB6 runtime being installed.

The VB6 runtime isn't installed on Windows by default.

Installing the IDE is one way to get the runtime. For non-developer machines, a "redistributable" installer package from Microsoft should be used instead.

Here is one VB6 runtime installer from Microsoft. I'm not sure if it will be the right version for your components:

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=7b9ba261-7a9c-43e7-9117-f673077ffb3c

How to print SQL statement in codeigniter model

Add this line right after the query you want to print.

Example:

$query = $this->db->query('SELECT * FROM table WHERE condition');

//Add this line.

var_dump($this->db->last_query());

exit();

or

echo $this->db->last_query();

How can I hide the Adobe Reader toolbar when displaying a PDF in the .NET WebBrowser control?

It appears the default setting for Adobe Reader X is for the toolbars not to be shown by default unless they are explicitly turned on by the user. And even when I turn them back on during a session, they don't show up automatically next time. As such, I suspect you have a preference set contrary to the default.

The state you desire, with the top and left toolbars not shown, is called "Read Mode". If you right-click on the document itself, and then click "Page Display Preferences" in the context menu that is shown, you'll be presented with the Adobe Reader Preferences dialog. (This is the same dialog you can access by opening the Adobe Reader application, and selecting "Preferences" from the "Edit" menu.) In the list shown in the left-hand column of the Preferences dialog, select "Internet". Finally, on the right, ensure that you have the "Display in Read Mode by default" box checked:

   Adobe Reader Preferences dialog

You can also turn off the toolbars temporarily by clicking the button at the right of the top toolbar that depicts arrows pointing to opposing corners:

   Adobe Reader Read Mode toolbar button

Finally, if you have "Display in Read Mode by default" turned off, but want to instruct the page you're loading not to display the toolbars (i.e., override the user's current preferences), you can append the following to the URL:

#toolbar=0&navpanes=0

So, for example, the following code will disable both the top toolbar (called "toolbar") and the left-hand toolbar (called "navpane"). However, if the user knows the keyboard combination (F8, and perhaps other methods as well), they will still be able to turn them back on.

string url = @"http://www.domain.com/file.pdf#toolbar=0&navpanes=0";
this._WebBrowser.Navigate(url);

You can read more about the parameters that are available for customizing the way PDF files open here on Adobe's developer website.

Command line: search and replace in all filenames matched by grep

If your sed(1) has a -i option, then use it like this:

for i in *; do
  sed -i 's/foo/bar/' $i
done

If not, there are several ways variations on the following depending on which language you want to play with:

ruby -i.bak -pe 'sub(%r{foo}, 'bar')' *
perl -pi.bak -e 's/foo/bar/' *

get the value of "onclick" with jQuery?

This works for me

 var link_click = $('#google').get(0).attributes.onclick.nodeValue;
 console.log(link_click);

SQL Server: Extract Table Meta-Data (description, fields and their data types)

I use this SQL code to get all the information about a column.

SELECT
COL.COLUMN_NAME,
ORDINAL_POSITION,
DATA_TYPE,
CHARACTER_MAXIMUM_LENGTH,
NUMERIC_PRECISION,
NUMERIC_PRECISION_RADIX,
NUMERIC_SCALE,
DATETIME_PRECISION,
IS_NULLABLE,
CONSTRAINT_TYPE,
COLUMNPROPERTY(object_id(COL.TABLE_NAME), COL.COLUMN_NAME, 'IsIdentity') IS_IDENTITY,
COLUMNPROPERTY(object_id(COL.TABLE_NAME), COL.COLUMN_NAME, 'IsComputed') IS_COMPUTED

FROM INFORMATION_SCHEMA.COLUMNS COL 
LEFT OUTER JOIN 
(
    SELECT COLUMN_NAME, CONSTRAINT_TYPE 
    FROM INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE A
    INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS B 
    ON A.CONSTRAINT_NAME = B.CONSTRAINT_NAME
    WHERE A.TABLE_NAME = 'User'
) CONS
ON COL.COLUMN_NAME = CONS.COLUMN_NAME
WHERE COL.TABLE_NAME = 'User'

How to use Javascript to read local text file and read line by line?

Using ES6 the javascript becomes a little cleaner

handleFiles(input) {

    const file = input.target.files[0];
    const reader = new FileReader();

    reader.onload = (event) => {
        const file = event.target.result;
        const allLines = file.split(/\r\n|\n/);
        // Reading line by line
        allLines.forEach((line) => {
            console.log(line);
        });
    };

    reader.onerror = (event) => {
        alert(event.target.error.name);
    };

    reader.readAsText(file);
}

Check if all elements in a list are identical

The simplest and most elegant way is as follows:

all(x==myList[0] for x in myList)

(Yes, this even works with the empty list! This is because this is one of the few cases where python has lazy semantics.)

Regarding performance, this will fail at the earliest possible time, so it is asymptotically optimal.

Adding additional data to select options using jQuery

I made two examples from what I think your question might be:

http://jsfiddle.net/grdn4/

Check this out for storing additional values. It uses data attributes to store the other value:

http://jsfiddle.net/27qJP/1/

Is there a link to the "latest" jQuery library on Google APIs?

Be aware that caching headers are different when you use "direct" vs. "latest" link from google.

When using http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js

Cache-Control: public, max-age=31536000

When using http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js

Cache-Control: public, max-age=3600, must-revalidate, proxy-revalidate

ImportError: No Module Named bs4 (BeautifulSoup)

Just tagging onto Balthazar's answer. Running

pip install BeautifulSoup4

did not work for me. Instead use

pip install beautifulsoup4

Why does scanf() need "%lf" for doubles, when printf() is okay with just "%f"?

scanf needs to know the size of the data being pointed at by &d to fill it properly, whereas variadic functions promote floats to doubles (not entirely sure why), so printf is always getting a double.

How to change Screen buffer size in Windows Command Prompt from batch script

You can change the buffer size of cmd by clicking the icon at top left corner -->properties --> layout --> screen buffer size.
you can even change it with cmd command

mode con:cols=100 lines=60
Upto lines = 58 the height of the cmd window changes ..
After lines value of 58 the buffer size of the cmd changes...

Get data type of field in select statement in ORACLE

You can query the all_tab_columns view in the database.

SELECT  table_name, column_name, data_type, data_length FROM all_tab_columns where table_name = 'CUSTOMER'

Add a column in a table in HIVE QL

You cannot add a column with a default value in Hive. You have the right syntax for adding the column ALTER TABLE test1 ADD COLUMNS (access_count1 int);, you just need to get rid of default sum(max_count). No changes to that files backing your table will happen as a result of adding the column. Hive handles the "missing" data by interpreting NULL as the value for every cell in that column.

So now your have the problem of needing to populate the column. Unfortunately in Hive you essentially need to rewrite the whole table, this time with the column populated. It may be easier to rerun your original query with the new column. Or you could add the column to the table you have now, then select all of its columns plus value for the new column.

You also have the option to always COALESCE the column to your desired default and leave it NULL for now. This option fails when you want NULL to have a meaning distinct from your desired default. It also requires you to depend on always remembering to COALESCE.

If you are very confident in your abilities to deal with the files backing Hive, you could also directly alter them to add your default. In general I would recommend against this because most of the time it will be slower and more dangerous. There might be some case where it makes sense though, so I've included this option for completeness.

When do I have to use interfaces instead of abstract classes?

If you are using JDK 8, there is no reason to use abstract classes because whatever we do with abstract classes we can now do it with interfaces because of default methods. If you use abstract class you have to extend it and there is a restriction that you can extends only once. But if you use interface you can implements as many as you want.

Interface is by default an abstract class an all methods and constructors are public.

Change output format for MySQL command line results to CSV

mysqldump utility can help you, basically with --tab option it's a wrapped for SELECT INTO OUTFILE statement.

Example:

mysqldump -u root -p --tab=/tmp world Country --fields-enclosed-by='"' --fields-terminated-by="," --lines-terminated-by="\n" --no-create-info

This will create csv formatted file /tmp/Country.txt

How to handle configuration in Go

I tried JSON. It worked. But I hate having to create the struct of the exact fields and types I might be setting. To me that was a pain. I noticed it was the method used by all the configuration options I could find. Maybe my background in dynamic languages makes me blind to the benefits of such verboseness. I made a new simple config file format, and a more dynamic-ish lib for reading it out.

https://github.com/chrisftw/ezconf

I am pretty new to the Go world, so it might not be the Go way. But it works, it is pretty quick, and super simple to use.

Pros

  • Super simple
  • Less code

Cons

  • No Arrays or Map types
  • Very flat file format
  • Non-standard conf files
  • Does have a little convention built-in, which I now if frowned upon in general in Go community. (Looks for config file in the config directory)

Error: Unable to run mksdcard SDK tool

In case of lubuntu 14.04 use

sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0 lib32stdc++6

P.S-no need to restart the system.

How to POST using HTTPclient content type = application/x-www-form-urlencoded

var nvc = new List<KeyValuePair<string, string>>();
nvc.Add(new KeyValuePair<string, string>("Input1", "TEST2"));
nvc.Add(new KeyValuePair<string, string>("Input2", "TEST2"));
var client = new HttpClient();
var req = new HttpRequestMessage(HttpMethod.Post, url) { Content = new FormUrlEncodedContent(nvc) };
var res = await client.SendAsync(req);

Or

var dict = new Dictionary<string, string>();
dict.Add("Input1", "TEST2");
dict.Add("Input2", "TEST2");
var client = new HttpClient();
var req = new HttpRequestMessage(HttpMethod.Post, url) { Content = new FormUrlEncodedContent(dict) };
var res = await client.SendAsync(req);

Sorting HTML table with JavaScript

I have edited the code from one of the example here to use jquery. It's still not 100% jquery though. Any thoughts on the two different versions, like what are the pros and cons of each?

function column_sort() {
    getCellValue = (tr, idx) => $(tr).find('td').eq( idx ).text();

    comparer = (idx, asc) => (a, b) => ((v1, v2) => 
        v1 !== '' && v2 !== '' && !isNaN(v1) && !isNaN(v2) ? v1 - v2 : v1.toString().localeCompare(v2)
        )(getCellValue(asc ? a : b, idx), getCellValue(asc ? b : a, idx));
    
    table = $(this).closest('table')[0];
    tbody = $(table).find('tbody')[0];

    elm = $(this)[0];
    children = elm.parentNode.children;
    Array.from(tbody.querySelectorAll('tr')).sort( comparer(
        Array.from(children).indexOf(elm), table.asc = !table.asc))
        .forEach(tr => tbody.appendChild(tr) );
}

table.find('thead th').on('click', column_sort);

Get data from JSON file with PHP

Get the content of the JSON file using file_get_contents():

$str = file_get_contents('http://example.com/example.json/');

Now decode the JSON using json_decode():

$json = json_decode($str, true); // decode the JSON into an associative array

You have an associative array containing all the information. To figure out how to access the values you need, you can do the following:

echo '<pre>' . print_r($json, true) . '</pre>';

This will print out the contents of the array in a nice readable format. Note that the second parameter is set to true in order to let print_r() know that the output should be returned (rather than just printed to screen). Then, you access the elements you want, like so:

$temperatureMin = $json['daily']['data'][0]['temperatureMin'];
$temperatureMax = $json['daily']['data'][0]['temperatureMax'];

Or loop through the array however you wish:

foreach ($json['daily']['data'] as $field => $value) {
    // Use $field and $value here
}

Demo!

Adding data attribute to DOM

in Jquery "data" doesn't refresh by default :

alert($('#outer').html());
var a = $('#mydiv').data('myval'); //getter
$('#mydiv').data("myval","20"); //setter
alert($('#outer').html());

You'd use "attr" instead for live update:

alert($('#outer').html());
var a = $('#mydiv').data('myval'); //getter
$('#mydiv').attr("data-myval","20"); //setter
alert($('#outer').html());

Regex - Should hyphens be escaped?

Correct on all fronts. Outside of a character class (that's what the "square brackets" are called) the hyphen has no special meaning, and within a character class, you can place a hyphen as the first or last character in the range (e.g. [-a-z] or [0-9-]), OR escape it (e.g. [a-z\-0-9]) in order to add "hyphen" to your class.

It's more common to find a hyphen placed first or last within a character class, but by no means will you be lynched by hordes of furious neckbeards for choosing to escape it instead.

(Actually... my experience has been that a lot of regex is employed by folks who don't fully grok the syntax. In these cases, you'll typically see everything escaped (e.g. [a-z\%\$\#\@\!\-\_]) simply because the engineer doesn't know what's "special" and what's not... so they "play it safe" and obfuscate the expression with loads of excessive backslashes. You'll be doing yourself, your contemporaries, and your posterity a huge favor by taking the time to really understand regex syntax before using it.)

Great question!

ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'db'

I was brought here by a different problem. Whenever I tried to login, i got that message because instead of authenticating correctly I logged in as anonymous user. The solution to my problem was:

To see which user you are, and whose permissions you have:

select user(), current_user();

To delete the pesky anonymous user:

drop user ''@'localhost';

Java Long primitive type maximum limit

Ranges from -9,223,372,036,854,775,808 to +9,223,372,036,854,775,807.

It will start from -9,223,372,036,854,775,808

Long.MIN_VALUE.

Java Object Null Check for method

If array of Books is null, return zero as it looks that method count total price of all Books provided - if no Book is provided, zero is correct value:

public static double calculateInventoryTotal(Book[] books)
{
if(books == null) return 0;
    double total = 0;
    for (int i = 0; i < books.length; i++)
    {
        total += books[i].getPrice();
    }
    return total;
}

It's upon to you to decide if it's correct that you can input null input value (shoul not be correct, but...).

Excel plot time series frequency with continuous xaxis

I would like to compliment Ram Narasimhans answer with some tips I found on an Excel blog

Non-uniformly distributed data can be plotted in excel in

  • X Y (Scatter Plots)
  • Linear plots with Date axis
    • These don't take time into account, only days.
    • This method is quite cumbersome as it requires translating your time units to days, months, or years.. then change the axis labels... Not Recommended

Just like Ram Narasimhan suggested, to have the points centered you will want the mid point but you don't need to move to a numeric format, you can stay in the time format.

1- Add the center point to your data series

+---------------+-------+------+
|    Time       | Time  | Freq |
+---------------+-------+------+
| 08:00 - 09:00 | 08:30 |  12  |
| 09:00 - 10:00 | 09:30 |  13  |
| 10:00 - 11:00 | 10:30 |  10  |
| 13:00 - 14:00 | 13:30 |   5  |
| 14:00 - 15:00 | 14:30 |  14  |
+---------------+-------+------+

2- Create a Scatter Plot

3- Excel allows you to specify time values for the axis options. Time values are a parts per 1 of a 24-hour day. Therefore if we want to 08:00 to 15:00, then we Set the Axis options to:

  • Minimum : Fix : 0.33333
  • Maximum : Fix : 0.625
  • Major unit : Fix : 0.041667

Line Scatter Plot


Alternative Display:

Make the points turn into columns:

To be able to represent these points as bars instead of just point we need to draw disjoint lines. Here is a way to go about getting this type of chart.

1- You're going to need to add several rows where we draw the line and disjoint the data

+-------+------+
| Time  | Freq |
+-------+------+
| 08:30 |   0  |
| 08:30 |  12  |
|       |      |
| 09:30 |   0  |
| 09:30 |  13  |
|       |      |
| 10:30 |   0  |
| 10:30 |  10  |
|       |      |
| 13:30 |   0  |
| 13:30 |   5  |
|       |      |
| 14:30 |   0  |
| 14:30 |  14  |
+-------+------+

2- Plot an X Y (Scatter) Chart with Lines.

3- Now you can tweak the data series to have a fatter line, no markers, etc.. to get a bar/column type chart with non-uniformly distributed data.

Bar-Line Scatter Plot

throwing exceptions out of a destructor

Set an alarm event. Typically alarm events are better form of notifying failure while cleaning up objects

How to simulate POST request?

This should help if you need a publicly exposed website but you're on a dev pc. Also to answer (I can't comment yet): "How do I post to an internal only running development server with this? – stryba "

NGROK creates a secure public URL to a local webserver on your development machine (Permanent URLs available for a fee, temporary for free).
1) Run ngrok.exe to open command line (on desktop)
2) Type ngrok.exe http 80 to start a tunnel,
3) test by browsing to the displayed web address which will forward and display the local default 80 page on your dev pc

Then use some of the tools recommended above to POST to your ngrok site ('https://xxxxxx.ngrok.io') to test your local code.

https://ngrok.com/

JS. How to replace html element with another element/text, represented in string?

idTABLE.parentElement.innerHTML =  '<span>123 element</span> 456';

while this works, it's still recommended to use getElementById: Do DOM tree elements with ids become global variables?

replaceChild would work fine if you want to go to the trouble of building up your replacement, element by element, using document.createElement and appendChild, but I don't see the point.

How to jQuery clone() and change id?

Update: As Roko C.Bulijan pointed out.. you need to use .insertAfter to insert it after the selected div. Also see updated code if you want it appended to the end instead of beginning when cloned multiple times. DEMO

Code:

   var cloneCount = 1;;
   $("button").click(function(){
      $('#id')
          .clone()
          .attr('id', 'id'+ cloneCount++)
          .insertAfter('[id^=id]:last') 
           //            ^-- Use '#id' if you want to insert the cloned 
           //                element in the beginning
          .text('Cloned ' + (cloneCount-1)); //<--For DEMO
   }); 

Try,

$("#id").clone().attr('id', 'id1').after("#id");

If you want a automatic counter, then see below,

   var cloneCount = 1;
   $("button").click(function(){
      $("#id").clone().attr('id', 'id'+ cloneCount++).insertAfter("#id");
   }); 

ReactJS Two components communicating

This is the way I handled this.
Let's say you have a <select> for Month and a <select> for Day. The number of days depends on the selected month.

Both lists are owned by a third object, the left panel. Both <select> are also children of the leftPanel <div>
It's a game with the callbacks and the handlers in the LeftPanel component.

To test it, just copy the code into two separated files and run the index.html. Then select a month and see how the number of days changes.

dates.js

    /** @jsx React.DOM */


    var monthsLength = [0,31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    var MONTHS_ARR = ["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"];

    var DayNumber = React.createClass({
        render: function() {
            return (
                <option value={this.props.dayNum}>{this.props.dayNum}</option>
            );
        }
    });

    var DaysList = React.createClass({
        getInitialState: function() {
            return {numOfDays: 30};
        },
        handleMonthUpdate: function(newMonthix) {
            this.state.numOfDays = monthsLength[newMonthix];
            console.log("Setting days to " + monthsLength[newMonthix] + " month = " + newMonthix);

            this.forceUpdate();
        },
        handleDaySelection: function(evt) {
            this.props.dateHandler(evt.target.value);
        },
        componentDidMount: function() {
            this.props.readyCallback(this.handleMonthUpdate)
        },
        render: function() {
            var dayNodes = [];
            for (i = 1; i <= this.state.numOfDays; i++) {
                dayNodes = dayNodes.concat([<DayNumber dayNum={i} />]);
            }
            return (
                <select id={this.props.id} onChange = {this.handleDaySelection}>
                    <option value="" disabled defaultValue>Day</option>
                        {dayNodes}
                </select>
                );
        }
    });

    var Month = React.createClass({
        render: function() {
            return (
                <option value={this.props.monthIx}>{this.props.month}</option>
            );
        }
    });

    var MonthsList = React.createClass({
        handleUpdate: function(evt) {
            console.log("Local handler:" + this.props.id + " VAL= " + evt.target.value);
            this.props.dateHandler(evt.target.value);

            return false;
        },
        render: function() {
            var monthIx = 0;

            var monthNodes = this.props.data.map(function (month) {
                monthIx++;
                return (
                    <Month month={month} monthIx={monthIx} />
                    );
            });

            return (
                <select id = {this.props.id} onChange = {this.handleUpdate}>
                    <option value="" disabled defaultValue>Month</option>
                        {monthNodes}
                </select>
                );
        }
    });

    var LeftPanel = React.createClass({
        dayRefresh: function(newMonth) {
            // Nothing - will be replaced
        },
        daysReady: function(refreshCallback) {
            console.log("Regisering days list");
        this.dayRefresh = refreshCallback;
        },
        handleMonthChange: function(monthIx) {
            console.log("New month");
            this.dayRefresh(monthIx);
        },
        handleDayChange: function(dayIx) {
            console.log("New DAY: " + dayIx);
        },
        render: function() {
            return(
                <div id="orderDetails">
                    <DaysList id="dayPicker" dateHandler={this.handleDayChange} readyCallback = {this.daysReady} />
                    <MonthsList data={MONTHS_ARR} id="monthPicker" dateHandler={this.handleMonthChange}  />
                </div>
            );
        }
    });



    React.renderComponent(
        <LeftPanel />,
        document.getElementById('leftPanel')
    );

And the HTML for running the left panel component index.html

<!DOCTYPE html>
<html>
<head>
    <title>Dates</title>

    <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
    <script src="//fb.me/react-0.11.1.js"></script>
    <script src="//fb.me/JSXTransformer-0.11.1.js"></script>
</head>

    <style>

        #dayPicker {
            position: relative;
            top: 97px;
            left: 20px;
            width: 60px;
            height: 17px;
        }

        #monthPicker {
            position: relative;
            top: 97px;
            left: 22px;
            width: 95px;
            height: 17px;
        }

        select {
            font-size: 11px;
        }

    </style>


    <body>
        <div id="leftPanel">
        </div>

        <script type="text/jsx" src="dates.js"></script>

    </body>
</html>

JavaFX: How to get stage from controller during initialization?

All you need is to give the AnchorPane an ID, and then you can get the Stage from that.

@FXML private AnchorPane ap;
Stage stage = (Stage) ap.getScene().getWindow();

From here, you can add in the Listener that you need.

Edit: As stated by EarthMind below, it doesn't have to be the AnchorPane element; it can be any element that you've defined.

useState set method not reflecting change immediately

// replace
return <p>hello</p>;
// with
return <p>{JSON.stringify(movies)}</p>;

Now you should see, that your code actually does work. What does not work is the console.log(movies). This is because movies points to the old state. If you move your console.log(movies) outside of useEffect, right above the return, you will see the updated movies object.

Create pandas Dataframe by appending one row at a time

Here is the way to add/append a row in pandas DataFrame

def add_row(df, row):
    df.loc[-1] = row
    df.index = df.index + 1  
    return df.sort_index()

add_row(df, [1,2,3]) 

It can be used to insert/append a row in empty or populated pandas DataFrame

Get the cartesian product of a series of lists?

I believe this works:

def cartesian_product(L):  
   if L:
       return {(a,) + b for a in L[0] 
                        for b in cartesian_product(L[1:])}
   else:
       return {()}

phpmyadmin logs out after 1440 secs

It worked for me after I

  • changed the $cfg['LoginCookieValidity'] in (phpmyadmin folder)/libraries/config.default.php to 999999999.

  • checked the php.ini used by the phpmyadmin by php5 -i | grep php.ini.

  • went to the php.ini file whose path I got from the grep command output and changed the session.gc_maxlifetime value to 999999999.

  • restarted the server. In my case it was sudo service apache2 restart.

Done. Logged in phpmyadmin and checked the cookie validity in Settings -> Features -> General -> Login cookie validity. It was 999999999. Also there was no warning "Your PHP parameter session.gc_maxlifetime is lower that cookie validity ...". The warning showed after I logged in phpmyadmin before I changed the php.ini file.

Check the version of php used by the phpmyadmin. You should change the ini file of the php that is used by the phpmyadmin. I have php5 and php(i.e 7) both installed. But my phpmyadmin uses php5. So I had to search for ini file of php5.

Error message "Forbidden You don't have permission to access / on this server"

I had the same issue for a specific controller only - which was really weird. I had a folder in the root of the CI folder that had the same name as the controller I was trying to access... Because of that, CI was directing the request to this directory instead of the controller itself.

After removing this folder (which was there a bit by mistake), it all worked fine.

To be more clear, here is what it looked like:

/ci/controller/register.php

/ci/register/

I had to remove /ci/register/.

Array.sort() doesn't sort numbers correctly

I've tried different numbers, and it always acts as if the 0s aren't there and sorts the numbers correctly otherwise. Anyone know why?

You're getting a lexicographical sort (e.g. convert objects to strings, and sort them in dictionary order), which is the default sort behavior in Javascript:

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/sort

array.sort([compareFunction])

Parameters

compareFunction

Specifies a function that defines the sort order. If omitted, the array is sorted lexicographically (in dictionary order) according to the string conversion of each element.

In the ECMAscript specification (the normative reference for the generic Javascript), ECMA-262, 3rd ed., section 15.4.4.11, the default sort order is lexicographical, although they don't come out and say it, instead giving the steps for a conceptual sort function that calls the given compare function if necessary, otherwise comparing the arguments when converted to strings:

13. If the argument comparefn is undefined, go to step 16.
14. Call comparefn with arguments x and y.
15. Return Result(14).
16. Call ToString(x).
17. Call ToString(y).
18. If Result(16) < Result(17), return -1.
19. If Result(16) > Result(17), return 1.
20. Return +0.

How do I 'foreach' through a two-dimensional array?

string[][] languages = new string[2][];
            languages[0] = new string[2];
            languages[1] = new string[3];
// inserting data into double dimensional arrays.
            for (int i = 0; i < 2; i++)
            {
                languages[0][i] = "Jagged"+i.ToString();
            }
            for (int j = 0; j < 3; j++)
            {
                languages[1][j] = "Jag"+j.ToString();
            }

// doing foreach through 2 dimensional arrays.
foreach (string[] s in languages)
            {
                foreach (string a in s)
                {
                    Console.WriteLine(a);
                }
            }

How to create an Explorer-like folder browser control?

Microsoft provides a walkthrough for creating a Windows Explorer style interface in C#.

There are also several examples on Code Project and other sites. Immediate examples are Explorer Tree, My Explorer, File Browser and Advanced File Explorer but there are others. Explorer Tree seems to look the best from the brief glance I took.

I used the search term windows explorer tree view C# in Google to find these links.

Does a `+` in a URL scheme/host/path represent a space?

use encodeURIComponent function to fix url, it works on Browser and node.js

res.redirect("/signin?email="+encodeURIComponent("[email protected]"));


> encodeURIComponent("http://a.com/a+b/c")
'http%3A%2F%2Fa.com%2Fa%2Bb%2Fc'

What do 3 dots next to a parameter type mean in Java?

Arguably, it is an example of syntactic sugar, since it is implemented as an array anyways (which doesn't mean it's useless) - I prefer passing an array to keep it clear, and also declare methods with arrays of given type. Rather an opinion than an answer, though.

grunt: command not found when running from terminal

I have been hunting around trying to solve this one for a while and none of the suggested updates to bash seemed to be working. What I discovered was that some point my npm root was modified such that it was pointing to a Users/USER_NAME/.node/node_modules while the actual installation of npm was living at /usr/local/lib/node_modules. You can check this by running npm root and npm root -g (for the global installation). To correct the path you can call npm config set prefix /usr/local.

How to blur background images in Android

This might be a very late reply but I hope it helps someone.

  1. You can use third party libs such as RenderScript/Blurry/etc.
  2. If you do not want to use any third party libs, you can do the below using alpha(setting alpha to 0 means complete blur and 1 means same as existing).

Note(If you are using point 2) : While setting alpha to the background, it will blur the whole layout. To avoid this, create a new xml containing drawable and set alpha here to 0.5 (or value of your wish) and use this drawable name (name of file) as the background.

For example, use it as below (say file name is bgndblur.xml):

<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:shape="rectangle"
android:src="@drawable/registerscreenbackground" 
android:alpha="0.5">

Use the below in your layout :

<....
 android:background="@drawable/bgndblur">

Hope this helped.

Why does "npm install" rewrite package-lock.json?

Probably you should use something like this

npm ci

Instead of using npm install if you don't want to change the version of your package.

According to the official documentation, both npm install and npm ci install the dependencies which are needed for the project.

The main difference is, npm install does install the packages taking packge.json as a reference. Where in the case of npm ci, it does install the packages taking package-lock.json as a reference, making sure every time the exact package is installed.

Subprocess check_output returned non-zero exit status 1

For Windows users: Try deleting files: java.exe, javaw.exe and javaws.exe from Windows\System32

My issue was the java version 1.7 installed.

How to resolve "The requested URL was rejected. Please consult with your administrator." error?

It is not related with Firewall. I had the same issue accessing from office and from mobile. I cleaned the cookies and worked fine. You can read more at https://support.google.com/chromebook/answer/1085581?hl=en

How do I execute a stored procedure in a SQL Agent job?

As Marc says, you run it exactly like you would from the command line. See Creating SQL Server Agent Jobs on MSDN.

Float a div right, without impacting on design

If you don't want the image to affect the layout at all (and float on top of other content) you can apply the following CSS to the image:

position:absolute;
right:0;
top:0;

If you want it to float at the right of a particular parent section, you can add position: relative to that section.

Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `ListView`

Change your code from:

render() {
    return (
      <ol>
        {this.props.results.map((result) => (
          <li>{result.text}</li>
        ))}
      </ol>
    );
}

To:

render() {
    return (
      <ol>
        {this.props.results.map((result) => (
          <li key={result.id}>{result.text}</li>
        ))}
      </ol>
    );
}

Then solved.

Send POST data via raw json with postman

Install Postman native app, Chrome extension has been deprecated. (Mine was opening in own window but still ran as Chrome app)

Select N random elements from a List<T> in C#

I think the selected answer is correct and pretty sweet. I implemented it differently though, as I also wanted the result in random order.

    static IEnumerable<SomeType> PickSomeInRandomOrder<SomeType>(
        IEnumerable<SomeType> someTypes,
        int maxCount)
    {
        Random random = new Random(DateTime.Now.Millisecond);

        Dictionary<double, SomeType> randomSortTable = new Dictionary<double,SomeType>();

        foreach(SomeType someType in someTypes)
            randomSortTable[random.NextDouble()] = someType;

        return randomSortTable.OrderBy(KVP => KVP.Key).Take(maxCount).Select(KVP => KVP.Value);
    }

How to set a default row for a query that returns no rows?

I figured it out, and it should also work for other systems too. It's a variation of WW's answer.

select rate 
from d_payment_index
where fy = 2007
  and payment_year = 2008
  and program_id = 18
union
select 0 as rate 
from d_payment_index 
where not exists( select rate 
                  from d_payment_index
                  where fy = 2007
                    and payment_year = 2008
                    and program_id = 18 )

How to create nested directories using Mkdir in Golang?

If the issue is to create all the necessary parent directories, you could consider using os.MkDirAll()

MkdirAll creates a directory named path, along with any necessary parents, and returns nil, or else returns an error.

The path_test.go is a good illustration on how to use it:

func TestMkdirAll(t *testing.T) {
    tmpDir := TempDir()
    path := tmpDir + "/_TestMkdirAll_/dir/./dir2"
    err := MkdirAll(path, 0777)
    if err != nil {
    t.Fatalf("MkdirAll %q: %s", path, err)
    }
    defer RemoveAll(tmpDir + "/_TestMkdirAll_")
...
}

(Make sure to specify a sensible permission value, as mentioned in this answer)