Programs & Examples On #Bigdata

Big data is a concept that deals with data sets of extreme volumes. Questions may tend to be related to infrastructure, algorithms, statistics, and data structures.

Hive ParseException - cannot recognize input near 'end' 'string'

You can always escape the reserved keyword if you still want to make your query work!!

Just replace end with `end`

Here is the list of reserved keywords https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL

CREATE EXTERNAL TABLE moveProjects (cid string, `end` string, category string)
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("dynamodb.table.name" = "Projects",
    "dynamodb.column.mapping" = "cid:cid,end:end,category:category");

How to copy data from one HDFS to another HDFS?

Try dtIngest, it's developed on top of Apache Apex platform. This tool copies data from different sources like HDFS, shared drive, NFS, FTP, Kafka to different destinations. Copying data from remote HDFS cluster to local HDFS cluster is supported by dtIngest. dtIngest runs yarn jobs to copy data in parallel fashion, so it's very fast. It takes care of failure handling, recovery etc. and supports polling directories periodically to do continious copy.

Usage: dtingest [OPTION]... SOURCEURL... DESTINATIONURL example: dtingest hdfs://nn1:8020/source hdfs://nn2:8020/dest

Hbase quickly count number of rows

If you're using a scanner, in your scanner try to have it return the least number of qualifiers as possible. In fact, the qualifier(s) that you do return should be the smallest (in byte-size) as you have available. This will speed up your scan tremendously.

Unfortuneately this will only scale so far (millions-billions?). To take it further, you can do this in real time but you will first need to run a mapreduce job to count all rows.

Store the Mapreduce output in a cell in HBase. Every time you add a row, increment the counter by 1. Every time you delete a row, decrement the counter.

When you need to access the number of rows in real time, you read that field in HBase.

There is no fast way to count the rows otherwise in a way that scales. You can only count so fast.

How to round up integer division and have int result in Java?

this might be helpfull,, Subtract the remainder to the legnth and make it a divisible number and then divide it with 153

int r=message.length()%153;       //Calculate the remainder by %153
return (message.length()-r)/153;  // find the pages by adding the remainder and 
                                  //then divide by 153 

how to make a countdown timer in java

You can create a countdown timer using applet, below is the code,

   import java.applet.*;
   import java.awt.*;
   import java.awt.event.*;
   import javax.swing.*;
   import javax.swing.Timer; // not java.util.Timer
   import java.text.NumberFormat;
   import java.net.*;



/**
    * An applet that counts down from a specified time. When it reaches 00:00,
    * it optionally plays a sound and optionally moves the browser to a new page.
    * Place the mouse over the applet to pause the count; move it off to resume.
    * This class demonstrates most applet methods and features.
    **/

public class Countdown extends JApplet implements ActionListener, MouseListener
{
long remaining; // How many milliseconds remain in the countdown.
long lastUpdate; // When count was last updated
JLabel label; // Displays the count
Timer timer; // Updates the count every second
NumberFormat format; // Format minutes:seconds with leading zeros
Image image; // Image to display along with the time
AudioClip sound; // Sound to play when we reach 00:00

// Called when the applet is first loaded
public void init() {
    // Figure out how long to count for by reading the "minutes" parameter
    // defined in a <param> tag inside the <applet> tag. Convert to ms.
    String minutes = getParameter("minutes");
    if (minutes != null) remaining = Integer.parseInt(minutes) * 60000;
    else remaining = 600000; // 10 minutes by default

    // Create a JLabel to display remaining time, and set some properties.
    label = new JLabel();
    label.setHorizontalAlignment(SwingConstants.CENTER );
    label.setOpaque(true); // So label draws the background color

    // Read some parameters for this JLabel object
    String font = getParameter("font");
    String foreground = getParameter("foreground");
    String background = getParameter("background");
    String imageURL = getParameter("image");

    // Set label properties based on those parameters
    if (font != null) label.setFont(Font.decode(font));
    if (foreground != null) label.setForeground(Color.decode(foreground));
    if (background != null) label.setBackground(Color.decode(background));
    if (imageURL != null) {
        // Load the image, and save it so we can release it later
        image = getImage(getDocumentBase(), imageURL);
        // Now display the image in the JLabel.
        label.setIcon(new ImageIcon(image));
    }

    // Now add the label to the applet. Like JFrame and JDialog, JApplet
    // has a content pane that you add children to
    getContentPane().add(label, BorderLayout.CENTER);

    // Get an optional AudioClip to play when the count expires
    String soundURL = getParameter("sound");
    if (soundURL != null) sound=getAudioClip(getDocumentBase(), soundURL);

    // Obtain a NumberFormat object to convert number of minutes and
    // seconds to strings. Set it up to produce a leading 0 if necessary
    format = NumberFormat.getNumberInstance();
    format.setMinimumIntegerDigits(2); // pad with 0 if necessary

    // Specify a MouseListener to handle mouse events in the applet.
    // Note that the applet implements this interface itself
    addMouseListener(this);

    // Create a timer to call the actionPerformed() method immediately,
    // and then every 1000 milliseconds. Note we don't start the timer yet.
    timer = new Timer(1000, this);
    timer.setInitialDelay(0); // First timer is immediate.
}

// Free up any resources we hold; called when the applet is done
public void destroy() { if (image != null) image.flush(); }

// The browser calls this to start the applet running
// The resume() method is defined below.
public void start() { resume(); } // Start displaying updates

// The browser calls this to stop the applet. It may be restarted later.
// The pause() method is defined below
public void stop() { pause(); } // Stop displaying updates

// Return information about the applet
public String getAppletInfo() {
    return "Countdown applet Copyright (c) 2003 by David Flanagan";
}

// Return information about the applet parameters
public String[][] getParameterInfo() { return parameterInfo; }

// This is the parameter information. One array of strings for each
// parameter. The elements are parameter name, type, and description.
static String[][] parameterInfo = {
    {"minutes", "number", "time, in minutes, to countdown from"},
    {"font", "font", "optional font for the time display"},
    {"foreground", "color", "optional foreground color for the time"},
    {"background", "color", "optional background color"},
    {"image", "image URL", "optional image to display next to countdown"},
    {"sound", "sound URL", "optional sound to play when we reach 00:00"},
    {"newpage", "document URL", "URL to load when timer expires"},
};

// Start or resume the countdown
void resume() {
    // Restore the time we're counting down from and restart the timer.
    lastUpdate = System.currentTimeMillis();
    timer.start(); // Start the timer
}

// Pause the countdown
void pause() {
    // Subtract elapsed time from the remaining time and stop timing
    long now = System.currentTimeMillis();
    remaining -= (now - lastUpdate);
    timer.stop(); // Stop the timer
}

// Update the displayed time. This method is called from actionPerformed()
// which is itself invoked by the timer.
void updateDisplay() {
    long now = System.currentTimeMillis(); // current time in ms
    long elapsed = now - lastUpdate; // ms elapsed since last update
    remaining -= elapsed; // adjust remaining time
    lastUpdate = now; // remember this update time

    // Convert remaining milliseconds to mm:ss format and display
    if (remaining < 0) remaining = 0;
    int minutes = (int)(remaining/60000);
    int seconds = (int)((remaining)/1000);
    label.setText(format.format(minutes) + ":" + format.format(seconds));

    // If we've completed the countdown beep and display new page
    if (remaining == 0) {
        // Stop updating now.
        timer.stop();
        // If we have an alarm sound clip, play it now.
        if (sound != null) sound.play();
        // If there is a newpage URL specified, make the browser
        // load that page now.
        String newpage = getParameter("newpage");
        if (newpage != null) {
            try {
                URL url = new URL(getDocumentBase(), newpage);
                getAppletContext().showDocument(url);
            }
            catch(MalformedURLException ex) {      showStatus(ex.toString()); }
        }
    }
}

// This method implements the ActionListener interface.
// It is invoked once a second by the Timer object
// and updates the JLabel to display minutes and seconds remaining.
public void actionPerformed(ActionEvent e) { updateDisplay(); }

// The methods below implement the MouseListener interface. We use
// two of them to pause the countdown when the mouse hovers over the timer.
// Note that we also display a message in the statusline
public void mouseEntered(MouseEvent e) {
    pause(); // pause countdown
    showStatus("Paused"); // display statusline message
}
public void mouseExited(MouseEvent e) {
    resume(); // resume countdown
    showStatus(""); // clear statusline
}
// These MouseListener methods are unused.
public void mouseClicked(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
} 

How do I install jmeter on a Mac?

Once you got the ZIP from the download, extract it locally, and with your finder, go in bin directory.

Then double-click on ApacheJMeter.jar to launch the User Interface of JMeter.

This and the next steps are described in a blog entry.

Android ADB commands to get the device properties

For Power-Shell

./adb shell getprop | Select-String -Pattern '(model)|(version.sdk)|(manufacturer)|(platform)|(serialno)|(product.name)|(brand)'

For linux(burrowing asnwer from @0x8BADF00D)

adb shell getprop | grep "model\|version.sdk\|manufacturer\|hardware\|platform\|revision\|serialno\|product.name\|brand"

For single string find in power shell

./adb shell getprop | Select-String -Pattern 'model'

or

./adb shell getprop | Select-String -Pattern '(model)'

For multiple

./adb shell getprop | Select-String -Pattern '(a|b|c|d)'

How to remove first and last character of a string?

this is perfectly working fine

String str = "[wdsd34svdf]";
//String str1 = str.replace("[","").replace("]", "");
String str1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(str1);


String strr = "[wdsd(340) svdf]";
String strr1 = str.replaceAll("[^a-zA-Z0-9]", "");
System.out.println(strr1);

How to discard all changes made to a branch?

When you want to discard changes in your local branch, you can stash these changes using git stash command.

git stash save "some_name"

Your changes will be saved and you can retrieve those later,if you want or you can delete it. After doing this, your branch will not have any uncommitted code and you can pull the latest code from your main branch using git pull.

Bootstrap - Removing padding or margin when screen size is smaller

The problem here is much more complex than removing the container padding since the grid structure relies on this padding when applying negative margins for the enclosed rows.

Removing the container padding in this case will cause an x-axis overflow caused by all the rows inside of this container class, this is one of the most stupid things about the Bootstrap Grid.

Logically it should be approached by

  1. Never using the .container class for anything other than rows
  2. Make a clone of the .container class that has no padding for use with non-grid html
  3. For removing the .container padding on mobile you can manually remove it with media queries then overflow-x: hidden; which is not very reliable but works in most cases.

If you are using LESS the end result will look like this

@media (max-width: @screen-md-max) {
    .container{
        padding: 0;
        overflow-x: hidden;
    }
}

Change the media query to whatever size you want to target.

Final thoughts, I would highly recommend using the Foundation Framework Grid as its way more advanced

How to use radio buttons in ReactJS?

Here is a simplest way of implementing radio buttons in react js.

_x000D_
_x000D_
class App extends React.Component {_x000D_
  _x000D_
  setGender(event) {_x000D_
    console.log(event.target.value);_x000D_
  }_x000D_
  _x000D_
  render() {_x000D_
    return ( _x000D_
      <div onChange={this.setGender.bind(this)}>_x000D_
        <input type="radio" value="MALE" name="gender"/> Male_x000D_
        <input type="radio" value="FEMALE" name="gender"/> Female_x000D_
      </div>_x000D_
     )_x000D_
  }_x000D_
}_x000D_
_x000D_
ReactDOM.render(<App/>, document.getElementById('app'));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="app"></div>
_x000D_
_x000D_
_x000D_

Edited

You can use arrow function instead of binding. Replace the above code as

<div onChange={event => this.setGender(event)}>

For a default value use defaultChecked, like this

<input type="radio" value="MALE" defaultChecked name="gender"/> Male

docker error: /var/run/docker.sock: no such file or directory

For boot2docker on Windows, after seeing:

FATA[0000] Get http:///var/run/docker.sock/v1.18/version: 
dial unix /var/run/docker.sock: no such file or directory.  
Are you trying to connect to a TLS-enabled daemon without TLS?

All I did was:

boot2docker start
boot2docker shellinit

That generated:

export DOCKER_CERT_PATH=C:\Users\vonc\.boot2docker\certs\boot2docker-vm
export DOCKER_TLS_VERIFY=1
export DOCKER_HOST=tcp://192.168.59.103:2376

Finally:

boot2docker ssh

And docker works again

JQuery create new select option

A really simple way to do this...

// create the option
var opt = $("<option>").val("myvalue").text("my text");

//append option to the select element
$(#my-select).append(opt);

This could be done in lots of ways, even in a single line if really you want to.

Android TextView Text not getting wrapped

For my case removing input type did the trick, i was using android:inputType="textPostalAddress" due to that my textview was sticked to one line and was not wrapping, removing this fixed the issue.

Trying to get property of non-object in

Your error

Notice: Trying to get property of non-object in C:\wamp\www\phone\pages\init.php on line 22

Your comment

@22 is <?php echo $sidemenu->mname."<br />";?>

$sidemenu is not an object, and you are trying to access one of its properties.

That is the reason for your error.

How to import NumPy in the Python shell

The message is fairly self-explanatory; your working directory should not be the NumPy source directory when you invoke Python; NumPy should be installed and your working directory should be anything but the directory where it lives.

Getting execute permission to xp_cmdshell

For users that are not members of the sysadmin role on the SQL Server instance you need to do the following actions to grant access to the xp_cmdshell extended stored procedure. In addition if you forgot one of the steps I have listed the error that will be thrown.

  1. Enable the xp_cmdshell procedure

    Msg 15281, Level 16, State 1, Procedure xp_cmdshell, Line 1 SQL Server blocked access to procedure 'sys.xp_cmdshell' of component 'xp_cmdshell' because this component is turned off as part of the security configuration for this server. A system administrator can enable the use of 'xp_cmdshell' by using sp_configure. For more information about enabling 'xp_cmdshell', see "Surface Area Configuration" in SQL Server Books Online.*

  2. Create a login for the non-sysadmin user that has public access to the master database

    Msg 229, Level 14, State 5, Procedure xp_cmdshell, Line 1 The EXECUTE permission was denied on the object 'xp_cmdshell', database 'mssqlsystemresource', schema 'sys'.*

  3. Grant EXEC permission on the xp_cmdshell stored procedure

    Msg 229, Level 14, State 5, Procedure xp_cmdshell, Line 1 The EXECUTE permission was denied on the object 'xp_cmdshell', database 'mssqlsystemresource', schema 'sys'.*

  4. Create a proxy account that xp_cmdshell will be run under using sp_xp_cmdshell_proxy_account

    Msg 15153, Level 16, State 1, Procedure xp_cmdshell, Line 1 The xp_cmdshell proxy account information cannot be retrieved or is invalid. Verify that the '##xp_cmdshell_proxy_account##' credential exists and contains valid information.*

It would seem from your error that either step 2 or 3 was missed. I am not familiar with clusters to know if there is anything particular to that setup.

Converting ArrayList to Array in java

This is the right answer you want and this solution i have run my self on netbeans

ArrayList a=new ArrayList();
a.add(1);
a.add(3);
a.add(4);
a.add(5);
a.add(8);
a.add(12);

int b[]= new int [6];
        Integer m[] = new Integer[a.size()];//***Very important conversion to array*****
        m=(Integer[]) a.toArray(m);
for(int i=0;i<a.size();i++)
{
    b[i]=m[i]; 
    System.out.println(b[i]);
}   
    System.out.println(a.size());

Why do I get "'property cannot be assigned" when sending an SMTP email?

This answer features:

Here's the extracted code:

    public async Task SendAsync(string subject, string body, string to)
    {
        using (var message = new MailMessage(smtpConfig.FromAddress, to)
        {
            Subject = subject,
            Body = body,
            IsBodyHtml = true
        })
        {
            using (var client = new SmtpClient()
            {
                Port = smtpConfig.Port,
                DeliveryMethod = SmtpDeliveryMethod.Network,
                UseDefaultCredentials = false,
                Host = smtpConfig.Host,
                Credentials = new NetworkCredential(smtpConfig.User, smtpConfig.Password),
            })
            {
                await client.SendMailAsync(message);
            }
        }                                     
    }

Class SmtpConfig:

public class SmtpConfig
{
    public string Host { get; set; }
    public string User { get; set; }
    public string Password { get; set; }
    public int Port { get; set; }
    public string FromAddress { get; set; }
}

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'

The sentence "Loading class 'com.mysql.jdbc.Driver'. This is deprecated. The new driver class is 'com.mysql.cj.jdbc.Driver' " is clear. You should use the newer driver, like this:

Class.forName("com.mysql.cj.jdbc.Driver");

And in mysql-connector-java-8.0.17. You would find that Class com.mysql.jdbc.Driver doesn't provide service any more. (You also can found the warning came from here.)

public class Driver extends com.mysql.cj.jdbc.Driver {
    public Driver() throws SQLException {
    }

    static {
        System.err.println("Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.");
    }
}

The sentence 'The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.' It mean that write code like this is ok:

//Class.forName("com.mysql.cj.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/world?useSSL=false&serverTimezone=Asia/Shanghai","root","root");

Due to SPI, driver is automatically registered. How does it work? You can find this from java.sql.DriverManager:

private static void ensureDriversInitialized() {
                          ...
    ServiceLoader<Driver> loadedDrivers = ServiceLoader.load(Driver.class);
                          ...
}

And in your mysql-connector-java-XXX.jar, you also can find the file 'java.sql.Driver' in the META-INF\services. The file as follows:

com.mysql.cj.jdbc.Driver

When you run DriverManager.getConnection(), the static block also start running. So driver can be automatically registered with file 'java.sql.Driver'.

And more about SPI -> Difference between SPI and API?.

How does one generate a random number in Apple's Swift language?

You can use GeneratorOf like this:

var fibs = ArraySlice([1, 1])
var fibGenerator = GeneratorOf{
    _ -> Int? in
    fibs.append(fibs.reduce(0, combine:+))
    return fibs.removeAtIndex(0)
}

println(fibGenerator.next())
println(fibGenerator.next())
println(fibGenerator.next())
println(fibGenerator.next())
println(fibGenerator.next())
println(fibGenerator.next())

How to close an iframe within iframe itself

None of this solution worked for me since I'm in a cross-domain scenario creating a bookmarklet like Pinterest's Pin It.

I've found a bookmarklet template on GitHub https://gist.github.com/kn0ll/1020251 that solved the problem of closing the Iframe sending the command from within it.

Since I can't access any element from parent window within the IFrame, this communication can only be made posting events between the two windows using window.postMessage

All these steps are on the GitHub link:

1- You have to inject a JS file on the parent page.

2- In this file injected on the parent, add a window event listner

    window.addEventListener('message', function(e) {
       var someIframe = window.parent.document.getElementById('iframeid');
       someIframe.parentNode.removeChild(window.parent.document.getElementById('iframeid'));
    });

This listener will handle the close and any other event you wish

3- Inside the Iframe page you send the close command via postMessage:

   $(this).trigger('post-message', [{
                    event: 'unload-bookmarklet'
                }]);

Follow the template on https://gist.github.com/kn0ll/1020251 and you'll be fine!

Hope it helps,

H2 database error: Database may be already in use: "Locked by another process"

You can also delete file of the h2 file database and problem will disappear.

jdbc:h2:~/dbname means that file h2 database with name db name will be created in the user home directory(~/ means user home directory, I hope you work on Linux).

In my local machine its present in: /home/jack/dbname.mv.db I don't know why file has a name dbname.mv.db instead a dbname. May be its a h2 default settings. I remove this file:

rm ~/dbname.mv.db 

OR:

cd ~/ 
rm dbname.mv.db 

Database dbname will be removed with all data. After new data base init all will be ok.

How do I convert Int/Decimal to float in C#?

It is just:

float f = (float)6;

Custom checkbox image android

If you are using custom adapters than android:focusable="false" and android:focusableInTouchMode="false" are nessesury to make list items clickable while using checkbox.

<CheckBox
        android:id="@+id/checkbox_fav"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:button="@drawable/checkbox_layout"/>

In drawable>checkbox_layout.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:drawable="@drawable/uncked_checkbox"
        android:state_checked="false"/>
    <item android:drawable="@drawable/selected_checkbox"
        android:state_checked="true"/>
    <item android:drawable="@drawable/uncked_checkbox"/>
</selector>

What is the maximum possible length of a .NET string?

Since String.Length is an integer (that is an alias for Int32), its size is limited to Int32.MaxValue unicode characters. ;-)

JQuery html() vs. innerHTML

Specifically regarding "Can I rely completely upon jquery html() method that it'll perform like innerHTML" my answer is NO!

Run this in internet explorer 7 or 8 and you'll see.

jQuery produces bad HTML when setting HTML containing a <FORM> tag nested within a <P> tag where the beginning of the string is a newline!

There are several test cases here and the comments when run should be self explanatory enough. This is quite obscure, but not understanding what's going on is a little disconcerting. I'm going to file a bug report.

<html>

    <head>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>   

        <script>
            $(function() {

                // the following two blocks of HTML are identical except the P tag is outside the form in the first case
                var html1 = "<p><form id='form1'><input type='text' name='field1' value='111' /><div class='foo' /><input type='text' name='field2' value='222' /></form></p>";
                var html2 = "<form id='form1'><p><input type='text' name='field1' value='111' /><div class='foo' /><input type='text' name='field2' value='222' /></p></form>";

                // <FORM> tag nested within <P>
                RunTest("<FORM> tag nested within <P> tag", html1);                 // succeeds in Internet Explorer    
                RunTest("<FORM> tag nested within <P> tag with leading newline", "\n" + html1);     // fails with added new line in Internet Explorer


                // <P> tag nested within <HTML>
                RunTest("<P> tag nested within <FORM> tag", html2);                 // succeeds in Internet Explorer
                RunTest("<P> tag nested within <FORM> tag with leading newline", "\n" + html2);     // succeeds in Internet Explorer even with \n

            });

            function RunTest(testName, html) {

                // run with jQuery
                $("#placeholder").html(html);
                var jqueryDOM = $('#placeholder').html();
                var jqueryFormSerialize = $("#placeholder form").serialize();

                // run with innerHTML
                $("#placeholder")[0].innerHTML = html;

                var innerHTMLDOM = $('#placeholder').html();
                var innerHTMLFormSerialize = $("#placeholder form").serialize();

                var expectedSerializedValue = "field1=111&field2=222";

                alert(  'TEST NAME: ' + testName + '\n\n' +
                    'The HTML :\n"' + html + '"\n\n' +
                    'looks like this in the DOM when assigned with jQuery.html() :\n"' + jqueryDOM + '"\n\n' +
                    'and looks like this in the DOM when assigned with innerHTML :\n"' + innerHTMLDOM + '"\n\n' +

                    'We expect the form to serialize with jQuery.serialize() to be "' + expectedSerializedValue + '"\n\n' +

                    'When using jQuery to initially set the DOM the serialized value is :\n"' + jqueryFormSerialize + '\n' +
                    'When using innerHTML to initially set the DOM the serialized value is :\n"' + innerHTMLFormSerialize + '\n\n' +

                    'jQuery test : ' + (jqueryFormSerialize == expectedSerializedValue ? "SUCCEEDED" : "FAILED") + '\n' +
                    'InnerHTML test : ' + (innerHTMLFormSerialize == expectedSerializedValue ? "SUCCEEDED" : "FAILED") 

                    );
            }

        </script>
    </head>

    <div id="placeholder">
        This is #placeholder text will 
    </div>

</html>

The object 'DF__*' is dependent on column '*' - Changing int to double

Solution :

open database table -> expand table -> expand constraints and see this

screenshot

What is difference between functional and imperative programming languages?

I know this question is older and others already explained it well, I would like to give an example problem which explains the same in simple terms.

Problem: Writing the 1's table.

Solution: -

By Imperative style: =>

    1*1=1
    1*2=2
    1*3=3
    .
    .
    .
    1*n=n 

By Functional style: =>

    1
    2
    3
    .
    .
    .
    n

Explanation in Imperative style we write the instructions more explicitly and which can be called as in more simplified manner.

Where as in Functional style, things which are self-explanatory will be ignored.

Change package name for Android in React Native

To change package I have searched and tried many methods but some are very hard and some are outdated. While searching I found a website that discuss a very simple method that are tested and personally i have also used this. Link : https://www.geoclassifieds.in/2021/02/change-package-name-react-native.html

How do I crop an image in Java?

This question has not enough information to answer. A general solution (depending on your GUI framework): add a mouse event handler that will catch clicks and mouse movements. This will give you your (x, y) coordinates. Next use these coordinates to crop your image.

RegEx to match stuff between parentheses

You need to make your regex pattern 'non-greedy' by adding a '?' after the '.+'

By default, '*' and '+' are greedy in that they will match as long a string of chars as possible, ignoring any matches that might occur within the string.

Non-greedy makes the pattern only match the shortest possible match.

See Watch Out for The Greediness! for a better explanation.

Or alternately, change your regex to

\(([^\)]+)\)

which will match any grouping of parens that do not, themselves, contain parens.

What do raw.githubusercontent.com URLs represent?

raw.githubusercontent.com/username/repo-name/branch-name/path

Replace username with the username of the user that created the repo.

Replace repo-name with the name of the repo.

Replace branch-name with the name of the branch.

Replace path with the path to the file.

To reverse to go to GitHub.com:

GitHub.com/username/repo-name/directory-path/blob/branch-name/filename

How do I call a Django function on button click?

here is a pure-javascript, minimalistic approach. I use JQuery but you can use any library (or even no libraries at all).

<html>
    <head>
        <title>An example</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script>
            function call_counter(url, pk) {
                window.open(url);
                $.get('YOUR_VIEW_HERE/'+pk+'/', function (data) {
                    alert("counter updated!");
                });
            }
        </script>
    </head>
    <body>
        <button onclick="call_counter('http://www.google.com', 12345);">
            I update object 12345
        </button>
        <button onclick="call_counter('http://www.yahoo.com', 999);">
            I update object 999
        </button>
    </body>
</html>

Alternative approach

Instead of placing the JavaScript code, you can change your link in this way:

<a target="_blank" 
    class="btn btn-info pull-right" 
    href="{% url YOUR_VIEW column_3_item.pk %}/?next={{column_3_item.link_for_item|urlencode:''}}">
    Check It Out
</a>

and in your views.py:

def YOUR_VIEW_DEF(request, pk):
    YOUR_OBJECT.objects.filter(pk=pk).update(views=F('views')+1)
    return HttpResponseRedirect(request.GET.get('next')))

How can I resolve the error "The security token included in the request is invalid" when running aws iam upload-server-certificate?

In my case, there were two different 'AWS_SECRET_ACCESS_KEY' and 'AWS_ACCESS_KEY_ID' values set one through the Windows environment variable and one through the command line.

So, update these two and the default_region using a command line

> aws configure

Press enter and follow the steps to fill the correct AWS_ACESS_KEY_ID AWS_SECRET_ACCESS_KEY and AWS_DEFAULT_REGION

> aws sts get-caller-identity

should return the new set credentials

Unable to set default python version to python3 in ubuntu

Set priority for default python in Linux terminal by adding this:

sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10
sudo update-alternatives --install /usr/bin/python python /usr/bin/python2 1

Here, we set python3 to have priority 10 and python2 to priority 1. This will make python3 the default python. If you want Python2 as default then make a priority of python2 higher then python3

Permanently hide Navigation Bar in an activity

There is a solution starting with KitKat (4.4.2), called Immersive Mode: https://developer.android.com/training/system-ui/immersive.html

Basically, you should add this code to your onResume() method:

View decorView = getWindow().getDecorView();
decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                              | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                              | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                              | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                              | View.SYSTEM_UI_FLAG_FULLSCREEN
                              | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);

UITableViewCell Selected Background Color on Multiple Selection

For Swift 3,4 and 5 you can do this in two ways.

1) class: UITableViewCell

override func awakeFromNib() {
    super.awakeFromNib()
    //Costumize cell

    selectionStyle = .none
}

or

2) tableView cellForRowAt

    cell.selectionStyle = .none

If you want to set selection color for specific cell, check this answer: https://stackoverflow.com/a/56166325/7987502

ZIP file content type for HTTP request

[request setValue:@"application/zip" forHTTPHeaderField:@"Content-Type"];

How can I compare time in SQL Server?

Using float does not work.

DECLARE @t1 datetime, @t2 datetime
SELECT @t1 = '19000101 23:55:00', @t2 = '20001102 23:55:00'
SELECT CAST(@t1 as float) - floor(CAST(@t1 as float)), CAST(@t2 as float) - floor(CAST(@t2 as float))

You'll see that the values are not the same (SQL Server 2005). I wanted to use this method to check for times around midnight (the full method has more detail) in which I was comparing the current time for being between 23:55:00 and 00:05:00.

How do I escape a percentage sign in T-SQL?

In MySQL,

WHERE column_name LIKE '%|%%' ESCAPE '|'

How can I create Min stl priority_queue?

Multiply values with -1 and use max heap to get the effect of min heap

Eclipse EGit Checkout conflict with files: - EGit doesn't want to continue

After you get from Eclipse the ugly CheckoutConflictException, the Eclipse-Merge Tool button is disabled.

Git need alle your files added to the Index for enable Merging.

So, to merge your Changes and commit them you need to add your files first to the index "Add to Index" and "Commit" them without "Push". Then you should see one pending pull and one pending push request in Eclipse. You see that in one up arrow and one down arrow.

If all conflict Files are in the commit, you can "pull" again. Then you will see something like:

\< < < < < < < HEAD Server Version \======= Local Version > > > > > > > branch 'master' of ....git

Then you either change it by the Merge-Tool, which is now enable or just do the merge by hand direct in the file. In the last step, you have to add the modified files again to the index and "Commit and Push" them.

Checking done!

java.lang.OutOfMemoryError: bitmap size exceeds VM budget - Android

One of the most common errors that I found developing Android Apps is the “java.lang.OutOfMemoryError: Bitmap Size Exceeds VM Budget” error. I found this error frequently on activities using lots of bitmaps after changing orientation: the Activity is destroyed, created again and the layouts are “inflated” from the XML consuming the VM memory available for bitmaps.

Bitmaps on the previous activity layout are not properly de-allocated by the garbage collector because they have crossed references to their activity. After many experiments I found a quite good solution for this problem.

First, set the “id” attribute on the parent view of your XML layout:

    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:id="@+id/RootView"
     >
     ...

Then, on the onDestroy() method of your Activity, call the unbindDrawables() method passing a reference to the parent View and then do a System.gc().

    @Override
    protected void onDestroy() {
    super.onDestroy();

    unbindDrawables(findViewById(R.id.RootView));
    System.gc();
    }

    private void unbindDrawables(View view) {
        if (view.getBackground() != null) {
        view.getBackground().setCallback(null);
        }
        if (view instanceof ViewGroup) {
            for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
            unbindDrawables(((ViewGroup) view).getChildAt(i));
            }
        ((ViewGroup) view).removeAllViews();
        }
    }

This unbindDrawables() method explores the view tree recursively and:

  1. Removes callbacks on all the background drawables
  2. Removes children on every viewgroup

How can I generate an INSERT script for an existing SQL Server table that includes all stored rows?

Just to share, I've developed my own script to do it. Feel free to use it. It generates "SELECT" statements that you can then run on the tables to generate the "INSERT" statements.

select distinct 'SELECT ''INSERT INTO ' + schema_name(ta.schema_id) + '.' + so.name + ' (' + substring(o.list, 1, len(o.list)-1) + ') VALUES ('
+ substring(val.list, 1, len(val.list)-1) + ');''  FROM ' + schema_name(ta.schema_id) + '.' + so.name + ';'
from    sys.objects so
join sys.tables ta on ta.object_id=so.object_id
cross apply
(SELECT '  ' +column_name + ', '
 from information_schema.columns c
 join syscolumns co on co.name=c.COLUMN_NAME and object_name(co.id)=so.name and OBJECT_NAME(co.id)=c.TABLE_NAME and co.id=so.object_id and c.TABLE_SCHEMA=SCHEMA_NAME(so.schema_id)
 where table_name = so.name
 order by ordinal_position
FOR XML PATH('')) o (list)
cross apply
(SELECT '''+' +case
         when data_type = 'uniqueidentifier' THEN 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '])+'''''''' END '
         WHEN data_type = 'timestamp' then '''''''''+CONVERT(NVARCHAR(MAX),CONVERT(BINARY(8),[' + COLUMN_NAME + ']),1)+'''''''''
         WHEN data_type = 'nvarchar' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+REPLACE([' + COLUMN_NAME + '],'''''''','''''''''''')+'''''''' END'
         WHEN data_type = 'varchar' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+REPLACE([' + COLUMN_NAME + '],'''''''','''''''''''')+'''''''' END'
         WHEN data_type = 'char' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+REPLACE([' + COLUMN_NAME + '],'''''''','''''''''''')+'''''''' END'
         WHEN data_type = 'nchar' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+REPLACE([' + COLUMN_NAME + '],'''''''','''''''''''')+'''''''' END'
         when DATA_TYPE='datetime' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '],121)+'''''''' END '
         when DATA_TYPE='datetime2' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '],121)+'''''''' END '
         when DATA_TYPE='geography' and column_name<>'Shape' then 'ST_GeomFromText(''POINT('+column_name+'.Lat '+column_name+'.Long)'') '
         when DATA_TYPE='geography' and column_name='Shape' then '''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '])+'''''''''
         when DATA_TYPE='bit' then '''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '])+'''''''''
         when DATA_TYPE='xml' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+REPLACE(CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + ']),'''''''','''''''''''')+'''''''' END '
         WHEN DATA_TYPE='image' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),CONVERT(VARBINARY(MAX),[' + COLUMN_NAME + ']),1)+'''''''' END '
         WHEN DATA_TYPE='varbinary' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '],1)+'''''''' END '
         WHEN DATA_TYPE='binary' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '],1)+'''''''' END '
         when DATA_TYPE='time' then 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE ''''''''+CONVERT(NVARCHAR(MAX),[' + COLUMN_NAME + '])+'''''''' END '
         ELSE 'CASE WHEN [' + column_name+'] IS NULL THEN ''NULL'' ELSE CONVERT(NVARCHAR(MAX),['+column_name+']) END' end
   + '+'', '
 from information_schema.columns c
 join syscolumns co on co.name=c.COLUMN_NAME and object_name(co.id)=so.name and OBJECT_NAME(co.id)=c.TABLE_NAME and co.id=so.object_id and c.TABLE_SCHEMA=SCHEMA_NAME(so.schema_id)
 where table_name = so.name
 order by ordinal_position
FOR XML PATH('')) val (list)
where   so.type = 'U'

How do you make a LinearLayout scrollable?

you need to use the following attribute and enclose it within the linear layout

<LinearLayout ...>
<scrollView ...> 

</scrollView>
</LinearLayout>

IOCTL Linux device driver

The ioctl function is useful for implementing a device driver to set the configuration on the device. e.g. a printer that has configuration options to check and set the font family, font size etc. ioctl could be used to get the current font as well as set the font to a new one. A user application uses ioctl to send a code to a printer telling it to return the current font or to set the font to a new one.

int ioctl(int fd, int request, ...)
  1. fd is file descriptor, the one returned by open;
  2. request is request code. e.g GETFONT will get the current font from the printer, SETFONT will set the font on the printer;
  3. the third argument is void *. Depending on the second argument, the third may or may not be present, e.g. if the second argument is SETFONT, the third argument can be the font name such as "Arial";

int request is not just a macro. A user application is required to generate a request code and the device driver module to determine which configuration on device must be played with. The application sends the request code using ioctl and then uses the request code in the device driver module to determine which action to perform.

A request code has 4 main parts

    1. A Magic number - 8 bits
    2. A sequence number - 8 bits
    3. Argument type (typically 14 bits), if any.
    4. Direction of data transfer (2 bits).  

If the request code is SETFONT to set font on a printer, the direction for data transfer will be from user application to device driver module (The user application sends the font name "Arial" to the printer). If the request code is GETFONT, direction is from printer to the user application.

In order to generate a request code, Linux provides some predefined function-like macros.

1._IO(MAGIC, SEQ_NO) both are 8 bits, 0 to 255, e.g. let us say we want to pause printer. This does not require a data transfer. So we would generate the request code as below

#define PRIN_MAGIC 'P'
#define NUM 0
#define PAUSE_PRIN __IO(PRIN_MAGIC, NUM) 

and now use ioctl as

ret_val = ioctl(fd, PAUSE_PRIN);

The corresponding system call in the driver module will receive the code and pause the printer.

  1. __IOW(MAGIC, SEQ_NO, TYPE) MAGIC and SEQ_NO are the same as above, and TYPE gives the type of the next argument, recall the third argument of ioctl is void *. W in __IOW indicates that the data flow is from user application to driver module. As an example, suppose we want to set the printer font to "Arial".
#define PRIN_MAGIC 'S'
#define SEQ_NO 1
#define SETFONT __IOW(PRIN_MAGIC, SEQ_NO, unsigned long)

further,

char *font = "Arial";
ret_val = ioctl(fd, SETFONT, font); 

Now font is a pointer, which means it is an address best represented as unsigned long, hence the third part of _IOW mentions type as such. Also, this address of font is passed to corresponding system call implemented in device driver module as unsigned long and we need to cast it to proper type before using it. Kernel space can access user space and hence this works. other two function-like macros are __IOR(MAGIC, SEQ_NO, TYPE) and __IORW(MAGIC, SEQ_NO, TYPE) where the data flow will be from kernel space to user space and both ways respectively.

Please let me know if this helps!

What is a quick way to force CRLF in C# / .NET?

Environment.NewLine;

A string containing "\r\n" for non-Unix platforms, or a string containing "\n" for Unix platforms.

Handling click events on a drawable within an EditText

I have implemented in Kotlin

edPassword.setOnTouchListener { _, event ->
            val DRAWABLE_RIGHT = 2
            val DRAWABLE_LEFT = 0
            val DRAWABLE_TOP = 1
            val DRAWABLE_BOTTOM = 3
            if (event.action == MotionEvent.ACTION_UP) {
                if (event.rawX >= (edPassword.right - edPassword.compoundDrawables[DRAWABLE_RIGHT].bounds.width())) {
                    edPassword.setText("")
                    true
                }
            }
            false
        }

Laravel Fluent Query Builder Join with subquery

I was looking for a solution to quite a related problem: finding the newest records per group which is a specialization of a typical greatest-n-per-group with N = 1.

The solution involves the problem you are dealing with here (i.e., how to build the query in Eloquent) so I am posting it as it might be helpful for others. It demonstrates a cleaner way of sub-query construction using powerful Eloquent fluent interface with multiple join columns and where condition inside joined sub-select.

In my example I want to fetch the newest DNS scan results (table scan_dns) per group identified by watch_id. I build the sub-query separately.

The SQL I want Eloquent to generate:

SELECT * FROM `scan_dns` AS `s`
INNER JOIN (
  SELECT x.watch_id, MAX(x.last_scan_at) as last_scan
  FROM `scan_dns` AS `x`
  WHERE `x`.`watch_id` IN (1,2,3,4,5,42)
  GROUP BY `x`.`watch_id`) AS ss
ON `s`.`watch_id` = `ss`.`watch_id` AND `s`.`last_scan_at` = `ss`.`last_scan`

I did it in the following way:

// table name of the model
$dnsTable = (new DnsResult())->getTable();

// groups to select in sub-query
$ids = collect([1,2,3,4,5,42]);

// sub-select to be joined on
$subq = DnsResult::query()
    ->select('x.watch_id')
    ->selectRaw('MAX(x.last_scan_at) as last_scan')
    ->from($dnsTable . ' AS x')
    ->whereIn('x.watch_id', $ids)
    ->groupBy('x.watch_id');
$qqSql = $subq->toSql();  // compiles to SQL

// the main query
$q = DnsResult::query()
    ->from($dnsTable . ' AS s')
    ->join(
        DB::raw('(' . $qqSql. ') AS ss'),
        function(JoinClause $join) use ($subq) {
            $join->on('s.watch_id', '=', 'ss.watch_id')
                 ->on('s.last_scan_at', '=', 'ss.last_scan')
                 ->addBinding($subq->getBindings());  
                 // bindings for sub-query WHERE added
        });

$results = $q->get();

UPDATE:

Since Laravel 5.6.17 the sub-query joins were added so there is a native way to build the query.

$latestPosts = DB::table('posts')
                   ->select('user_id', DB::raw('MAX(created_at) as last_post_created_at'))
                   ->where('is_published', true)
                   ->groupBy('user_id');

$users = DB::table('users')
        ->joinSub($latestPosts, 'latest_posts', function ($join) {
            $join->on('users.id', '=', 'latest_posts.user_id');
        })->get();

How do I read a string entered by the user in C?

Using scanf removing any blank spaces before the string is typed and limiting the amount of characters to be read:

#define SIZE 100

....

char str[SIZE];

scanf(" %99[^\n]", str);

/* Or even you can do it like this */

scanf(" %99[a-zA-Z0-9 ]", str);

If you do not limit the amount of characters to be read with scanf it can be as dangerous as gets

Using SQL LOADER in Oracle to import CSV file

"Line 1" - maybe something about windows vs unix newlines? (as i saw windows 7 mentioned above).

Default visibility for C# classes and members (fields, methods, etc.)?

All of the information you are looking for can be found here and here (thanks Reed Copsey):

From the first link:

Classes and structs that are declared directly within a namespace (in other words, that are not nested within other classes or structs) can be either public or internal. Internal is the default if no access modifier is specified.

...

The access level for class members and struct members, including nested classes and structs, is private by default.

...

interfaces default to internal access.

...

Delegates behave like classes and structs. By default, they have internal access when declared directly within a namespace, and private access when nested.


From the second link:

Top-level types, which are not nested in other types, can only have internal or public accessibility. The default accessibility for these types is internal.

And for nested types:

Members of    Default member accessibility
----------    ----------------------------
enum          public
class         private
interface     public
struct        private

Changing the action of a form with JavaScript/jQuery

I agree with Paolo that we need to see more code. I tested this overly simplified example and it worked. This means that it is able to change the form action on the fly.

<script type="text/javascript">
function submitForm(){
    var form_url = $("#openid_form").attr("action");
    alert("Before - action=" + form_url);   
    //changing the action to google.com
    $("#openid_form").attr("action","http://google.com");
    alert("After - action = "+$("#openid_form").attr("action"));
    //submit the form
    $("#openid_form").submit();
}
</script>


<form id="openid_form" action="test.html">
    First Name:<input type="text" name="fname" /><br/>
    Last Name: <input type="text" name="lname" /><br/>
    <input type="button" onclick="submitForm()" value="Submit Form" />
</form>

EDIT: I tested the updated code you posted and found a syntax error in the declaration of providers_large. There's an extra comma. Firefox ignores the issue, but IE8 throws an error.

var providers_large = {
    google: {
        name: 'Google',
        url: 'https://www.google.com/accounts/o8/id'
    },
    facebook: {
        name: 'Facebook',
        form_url: 'http://wikipediamaze.rpxnow.com/facebook/start?token_url=http://www.wikipediamaze.com/Accounts/Logon'
    },  //<-- Here's the problem. Remove that comma

};

Closing a Userform with Unload Me doesn't work

It should also be noted that if you have buttons grouped together on your user form that it can link it to a different button in the group despite the one you intended being clicked.

Java - Getting Data from MySQL database

Something like this would do:

public static void main(String[] args) {

    Connection con = null;
    Statement st = null;
    ResultSet rs = null;

    String url = "jdbc:mysql://localhost/t";
    String user = "";
    String password = "";

    try {
        Class.forName("com.mysql.jdbc.Driver");
        con = DriverManager.getConnection(url, user, password);
        st = con.createStatement();
        rs = st.executeQuery("SELECT * FROM posts ORDER BY id DESC LIMIT 1;");

        if (rs.next()) {//get first result
            System.out.println(rs.getString(1));//coloumn 1
        }

    } catch (SQLException ex) {
        Logger lgr = Logger.getLogger(Version.class.getName());
        lgr.log(Level.SEVERE, ex.getMessage(), ex);

    } finally {
        try {
            if (rs != null) {
                rs.close();
            }
            if (st != null) {
                st.close();
            }
            if (con != null) {
                con.close();
            }

        } catch (SQLException ex) {
            Logger lgr = Logger.getLogger(Version.class.getName());
            lgr.log(Level.WARNING, ex.getMessage(), ex);
        }
    }
}

you can iterate over the results with a while like this:

while(rs.next())
{
System.out.println(rs.getString("Colomn_Name"));//or getString(1) for coloumn 1 etc
}

There are many other great tutorial out there like these to list a few:

As for your use of Class.forName("com.mysql.jdbc.Driver").newInstance(); see JDBC connection- Class.forName vs Class.forName().newInstance? which shows how you can just use Class.forName("com.mysql.jdbc.Driver") as its not necessary to initiate it yourself

References:

Trigger change event of dropdown

For some reason, the other jQuery solutions provided here worked when running the script from console, however, it did not work for me when triggered from Chrome Bookmarklets.

Luckily, this Vanilla JS solution (the triggerChangeEvent function) did work:

_x000D_
_x000D_
/**_x000D_
  * Trigger a `change` event on given drop down option element._x000D_
  * WARNING: only works if not already selected._x000D_
  * @see https://stackoverflow.com/questions/902212/trigger-change-event-of-dropdown/58579258#58579258_x000D_
  */_x000D_
function triggerChangeEvent(option) {_x000D_
  // set selected property_x000D_
  option.selected = true;_x000D_
  _x000D_
  // raise event on parent <select> element_x000D_
  if ("createEvent" in document) {_x000D_
    var evt = document.createEvent("HTMLEvents");_x000D_
    evt.initEvent("change", false, true);_x000D_
    option.parentNode.dispatchEvent(evt);_x000D_
  }_x000D_
  else {_x000D_
    option.parentNode.fireEvent("onchange");_x000D_
  }_x000D_
}_x000D_
_x000D_
// ################################################_x000D_
// Setup our test case_x000D_
// ################################################_x000D_
_x000D_
(function setup() {_x000D_
  const sel = document.querySelector('#fruit');_x000D_
  sel.onchange = () => {_x000D_
    document.querySelector('#result').textContent = sel.value;_x000D_
  };_x000D_
})();_x000D_
_x000D_
function runTest() {_x000D_
  const sel = document.querySelector('#selector').value;_x000D_
  const optionEl = document.querySelector(sel);_x000D_
  triggerChangeEvent(optionEl);_x000D_
}
_x000D_
<select id="fruit">_x000D_
  <option value="">(select a fruit)</option>_x000D_
  <option value="apple">Apple</option>_x000D_
  <option value="banana">Banana</option>_x000D_
  <option value="pineapple">Pineapple</option>_x000D_
</select>_x000D_
_x000D_
<p>_x000D_
  You have selected: <b id="result"></b>_x000D_
</p>_x000D_
<p>_x000D_
  <input id="selector" placeholder="selector" value="option[value='banana']">_x000D_
  <button onclick="runTest()">Trigger select!</button>_x000D_
</p>
_x000D_
_x000D_
_x000D_

Using PHP variables inside HTML tags?

You can embed a variable into a double quoted string like my first example, or you can use concantenation(the period) like in my second example:

echo "<a href=\"http://www.whatever.com/$param\">Click Here</a>";

echo '<a href="http://www.whatever.com/' . $param . '">Click Here</a>';

Notice that I escaped the double quotes inside my first example using a backslash.

.NET Events - What are object sender & EventArgs e?

sender refers to the object that invoked the event that fired the event handler. This is useful if you have many objects using the same event handler.

EventArgs is something of a dummy base class. In and of itself it's more or less useless, but if you derive from it, you can add whatever data you need to pass to your event handlers.

When you implement your own events, use an EventHandler or EventHandler<T> as their type. This guarantees that you'll have exactly these two parameters for all your events (which is a good thing).

How to run ~/.bash_profile in mac terminal

You would never want to run that, but you may want to source it.

. ~/.bash_profile
source ~/.bash_profile

both should work. But this is an odd request, because that file should be sourced automatically when you start bash, unless you're explicitly starting it non-interactively. From the man page:

When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if that file exists. After reading that file, it looks for ~/.bash_profile, ~/.bash_login, and ~/.profile, in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

How do I get a plist as a Dictionary in Swift?

In swift 3.0 Reading from Plist.

func readPropertyList() {
        var propertyListFormat =  PropertyListSerialization.PropertyListFormat.xml //Format of the Property List.
        var plistData: [String: AnyObject] = [:] //Our data
        let plistPath: String? = Bundle.main.path(forResource: "data", ofType: "plist")! //the path of the data
        let plistXML = FileManager.default.contents(atPath: plistPath!)!
        do {//convert the data to a dictionary and handle errors.
            plistData = try PropertyListSerialization.propertyList(from: plistXML, options: .mutableContainersAndLeaves, format: &propertyListFormat) as! [String:AnyObject]

        } catch {
            print("Error reading plist: \(error), format: \(propertyListFormat)")
        }
    }

Read More HOW TO USE PROPERTY LISTS (.PLIST) IN SWIFT.

How to include duplicate keys in HashMap?

Use Map<Integer, List<String>>:

Map<Integer, List<String>> map = new LinkedHashMap< Integer, List<String>>();

map.put(-1505711364, new ArrayList<>(Arrays.asList("4")));
map.put(294357273, new ArrayList<>(Arrays.asList("15", "71")));
//...

To add a new key/value pair in this map:

public void add(Integer key, String newValue) {
    List<String> currentValue = map.get(key);
    if (currentValue == null) {
        currentValue = new ArrayList<String>();
        map.put(key, currentValue);
    }
    currentValue.add(newValue);
}

How to import a module given its name as string?

Nowadays you should use importlib.

Import a source file

The docs actually provide a recipe for that, and it goes like:

import sys
import importlib.util

file_path = 'pluginX.py'
module_name = 'pluginX'

spec = importlib.util.spec_from_file_location(module_name, file_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module)

# check if it's all there..
def bla(mod):
    print(dir(mod))
bla(module)

This way you can access the members (e.g, a function "hello") from your module pluginX.py -- in this snippet being called module -- under its namespace; E.g, module.hello().

If you want to import the members (e.g, "hello") you can include module/pluginX in the in-memory list of modules:

sys.modules[module_name] = module

from pluginX import hello
hello()

Import a package

Importing a package (e.g., pluginX/__init__.py) under your current dir is actually straightforward:

import importlib

pkg = importlib.import_module('pluginX')

# check if it's all there..
def bla(mod):
    print(dir(mod))
bla(pkg)

Why is access to the path denied?

I had the same problem on a newly moved website on a shared server. Solved through the web host panel (DotNetPanel) setting true the "allow write permissions". So if you are in a shared server before reviewing all code worth taking a look at the server configuration and could save you a lot of time.

PANIC: Cannot find AVD system path. Please define ANDROID_SDK_ROOT (in windows 10)

In Korean version of Windows 10, this problem happened because my Windows user name was in Korean not in English. After the user name was made again in English, the problem was cleared.

How to reset db in Django? I get a command 'reset' not found error

For me this solved the problem.

heroku pg:reset DATABASE_URL

heroku run bash
>> Inside heroku bash
cd app_name && rm -rf migrations && cd ..
./manage.py makemigrations app_name
./manage.py migrate

Empty or Null value display in SSRS text boxes

I would disagree with converting it on the server side. If you do that it's going to come back as a string type rather than a date type with all that entails (it will sort as a string for example)

My principle when dealing with dates is to keep them typed as a date for as long as you possibly can.

If your facing a performance bottleneck on the report server there are better ways to handle it than compromising your logic.

Android charting libraries

If you're looking for something more straight forward to implement (and it doesn't include pie/donut charts) then I recommend WilliamChart. Specially if motion takes an important role in your app design. In other hand if you want featured charts, then go for MPAndroidChart.

Simple post to Web Api

It's been quite sometime since I asked this question. Now I understand it more clearly, I'm going to put a more complete answer to help others.

In Web API, it's very simple to remember how parameter binding is happening.

  • if you POST simple types, Web API tries to bind it from the URL
  • if you POST complex type, Web API tries to bind it from the body of the request (this uses a media-type formatter).

  • If you want to bind a complex type from the URL, you'll use [FromUri] in your action parameter. The limitation of this is down to how long your data going to be and if it exceeds the url character limit.

    public IHttpActionResult Put([FromUri] ViewModel data) { ... }

  • If you want to bind a simple type from the request body, you'll use [FromBody] in your action parameter.

    public IHttpActionResult Put([FromBody] string name) { ... }

as a side note, say you are making a PUT request (just a string) to update something. If you decide not to append it to the URL and pass as a complex type with just one property in the model, then the data parameter in jQuery ajax will look something like below. The object you pass to data parameter has only one property with empty property name.

var myName = 'ABC';
$.ajax({url:.., data: {'': myName}});

and your web api action will look something like below.

public IHttpActionResult Put([FromBody] string name){ ... }

This asp.net page explains it all. http://www.asp.net/web-api/overview/formats-and-model-binding/parameter-binding-in-aspnet-web-api

A top-like utility for monitoring CUDA activity on a GPU

To get real-time insight on used resources, do:

nvidia-smi -l 1

This will loop and call the view at every second.

If you do not want to keep past traces of the looped call in the console history, you can also do:

watch -n0.1 nvidia-smi

Where 0.1 is the time interval, in seconds.

enter image description here

Format numbers in thousands (K) in Excel

I've found the following combination that works fine for positive and negative numbers (43787200020 is transformed to 43.787.200,02 K)

[>=1000] #.##0,#0. "K";#.##0,#0. "K"

How to unsubscribe to a broadcast event in angularJS. How to remove function registered via $on

Looking at most of the replies, they seem overly complicated. Angular has built in mechanisms to unregister.

Use the deregistration function returned by $on :

// Register and get a handle to the listener
var listener = $scope.$on('someMessage', function () {
    $log.log("Message received");
});

// Unregister
$scope.$on('$destroy', function () {
    $log.log("Unregistering listener");
    listener();
});

Getting JavaScript object key list

using slice, apply and join method.

var print = Array.prototype.slice.apply( obj );
alert('length='+print.length+' list'+print.join());

Changing the selected option of an HTML Select element

After a lot of searching I tried @kzh on select list where I only know option inner text not value attribute, this code based on select answer I used it to change select option according to current page urlon this format http://www.example.com/index.php?u=Steve

<select id="sel">
    <option>Joe</option>
    <option>Steve</option>
    <option>Jack</option>
</select>
<script>
    var val = window.location.href.split('u=')[1]; // to filter ?u= query 
    var sel = document.getElementById('sel');
    var opts = sel.options;
    for(var opt, j = 0; opt = opts[j]; j++) {
        // search are based on text inside option Attr
        if(opt.text == val) {
            sel.selectedIndex = j;
            break;
        }
    }
</script>

This will keeps url parameters shown as selected to make it more user friendly and the visitor knows what page or profile he is currently viewing .

Can jQuery get all CSS styles associated with an element?

Why not use .style of the DOM element? It's an object which contains members such as width and backgroundColor.

Command to find information about CPUs on a UNIX machine

Firstly, it probably depends which version of Solaris you're running, but also what hardware you have.

On SPARC at least, you have psrinfo to show you processor information, which run on its own will show you the number of CPUs the machine sees. psrinfo -p shows you the number of physical processors installed. From that you can deduce the number of threads/cores per physical processors.

prtdiag will display a fair bit of info about the hardware in your machine. It looks like on a V240 you do get memory channel info from prtdiag, but you don't on a T2000. I guess that's an architecture issue between UltraSPARC IIIi and UltraSPARC T1.

AsyncTask Android example

Ok, you are trying to access the GUI via another thread. This, in the main, is not good practice.

The AsyncTask executes everything in doInBackground() inside of another thread, which does not have access to the GUI where your views are.

preExecute() and postExecute() offer you access to the GUI before and after the heavy lifting occurs in this new thread, and you can even pass the result of the long operation to postExecute() to then show any results of processing.

See these lines where you are later updating your TextView:

TextView txt = findViewById(R.id.output);
txt.setText("Executed");

Put them in onPostExecute().

You will then see your TextView text updated after the doInBackground completes.

I noticed that your onClick listener does not check to see which View has been selected. I find the easiest way to do this is via switch statements. I have a complete class edited below with all suggestions to save confusion.

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.Settings.System;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.view.View.OnClickListener;

public class AsyncTaskActivity extends Activity implements OnClickListener {

    Button btn;
    AsyncTask<?, ?, ?> runningTask;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        btn = findViewById(R.id.button1);

        // Because we implement OnClickListener, we only
        // have to pass "this" (much easier)
        btn.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        // Detect the view that was "clicked"
        switch (view.getId()) {
        case R.id.button1:
            if (runningTask != null)
                runningTask.cancel(true);
            runningTask = new LongOperation();
            runningTask.execute();
            break;
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        // Cancel running task(s) to avoid memory leaks
        if (runningTask != null)
            runningTask.cancel(true);
    }

    private final class LongOperation extends AsyncTask<Void, Void, String> {

        @Override
        protected String doInBackground(Void... params) {
            for (int i = 0; i < 5; i++) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    // We were cancelled; stop sleeping!
                }
            }
            return "Executed";
        }

        @Override
        protected void onPostExecute(String result) {
            TextView txt = (TextView) findViewById(R.id.output);
            txt.setText("Executed"); // txt.setText(result);
            // You might want to change "executed" for the returned string
            // passed into onPostExecute(), but that is up to you
        }
    }
}

How do you create a dropdownlist from an enum in ASP.NET MVC?

In ASP.NET MVC 5.1, they added the EnumDropDownListFor() helper, so no need for custom extensions:

Model:

public enum MyEnum
{
    [Display(Name = "First Value - desc..")]
    FirstValue,
    [Display(Name = "Second Value - desc...")]
    SecondValue
}

View:

@Html.EnumDropDownListFor(model => model.MyEnum)

Using Tag Helper (ASP.NET MVC 6):

<select asp-for="@Model.SelectedValue" asp-items="Html.GetEnumSelectList<MyEnum>()">

CSS:Defining Styles for input elements inside a div

You can define style rules which only apply to specific elements inside your div with id divContainer like this:

#divContainer input { ... }
#divContainer input[type="radio"] { ... }
#divContainer input[type="text"] { ... }
/* etc */

'tsc command not found' in compiling typescript

This works perfectly on Mac. Tested on macOS High Sierra

sudo npm install -g concurrently
sudo npm install -g lite-server
sudo npm install -g typescript
tsc --init

This generates the tsconfig.json file.

Credit card payment gateway in PHP?

The best solution we found was to team up with one of those intermediaries. Otherwise you will have to deal with a bunch of other requirements like PCI compliance. We use Verifone's IPCharge and it works quite well.

In an array of objects, fastest way to find the index of an object whose attributes match a search

array.forEach(function (elem, i) {  // iterate over all elements of array
    indexes[elem.id] = i;           // take the found id as index for the
});                                 // indexes array and assign i

the result is a look up list for the id. with the given id we get the index of the record.

Problems with installation of Google App Engine SDK for php in OS X

It's likely that the download was corrupted if you are getting an error with the disk image. Go back to the downloads page at https://developers.google.com/appengine/downloads and look at the SHA1 checksum. Then, go to your Terminal app on your mac and run the following:

openssl sha1 [put the full path to the file here without brackets] 

For example:

openssl sha1 /Users/me/Desktop/myFile.dmg 

If you get a different value than the one on the Downloads page, you know your file is not properly downloaded and you should try again.

How to fill a Javascript object literal with many static key/value pairs efficiently?

Give this a try:

var map = {"aaa": "rrr", "bbb": "ppp"};

How should you diagnose the error SEHException - External component has thrown an exception

Yes. This error is a structured exception that wasn't mapped into a .NET error. It's probably your DataGrid mapping throwing a native exception that was uncaught.

You can tell what exception is occurring by looking at the ExternalException.ErrorCode property. I'd check your stack trace, and if it's tied to the DevExpress grid, report the problem to them.

Excel - programm cells to change colour based on another cell

Use conditional formatting.

You can enter a condition using any cell you like and a format to apply if the formula is true.

RabbitMQ / AMQP: single queue, multiple consumers for same message?

Yes each consumer can receive the same messages. have a look at http://www.rabbitmq.com/tutorials/tutorial-three-python.html http://www.rabbitmq.com/tutorials/tutorial-four-python.html http://www.rabbitmq.com/tutorials/tutorial-five-python.html

for different ways to route messages. I know they are for python and java but its good to understand the principles, decide what you are doing and then find how to do it in JS. Its sounds like you want to do a simple fanout (tutorial 3), which sends the messages to all queues connected to the exchange.

The difference with what you are doing and what you want to do is basically that you are going to set up and exchange or type fanout. Fanout excahnges send all messages to all connected queues. Each queue will have a consumer that will have access to all the messages separately.

Yes this is commonly done, it is one of the features of AMPQ.

Nested or Inner Class in PHP

You cannot do this in PHP. However, there are functional ways to accomplish this.

For more details please check this post: How to do a PHP nested class or nested methods?

This way of implementation is called fluent interface: http://en.wikipedia.org/wiki/Fluent_interface

CURL and HTTPS, "Cannot resolve host"

Your getting the error because you're probably doing it on your Local server environment. You need to skip the certificates check when the cURL call is made. For that just add the following options

curl_setopt($c, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($c, CURLOPT_SSL_VERIFYHOST,  0);

Checking the equality of two slices

This is just example using reflect.DeepEqual() that is given in @VictorDeryagin's answer.

package main

import (
    "fmt"
    "reflect"
)

func main() {
    a := []int {4,5,6}
    b := []int {4,5,6}
    c := []int {4,5,6,7}

    fmt.Println(reflect.DeepEqual(a, b))
    fmt.Println(reflect.DeepEqual(a, c))

}

Result:

true
false

Try it in Go Playground

How can I import Swift code to Objective-C?

First Step:-

Select Project Target -> Build Setting -> Search('Define') -> Define Module update value No to Yes

"Defines Module": YES.

"Always Embed Swift Standard Libraries" : YES.

"Install Objective-C Compatibility Header" : YES.

enter image description here

Second Step:-

Add Swift file Class in Objective C ".h" File as below

#import <UIKit/UIKit.h>

@class TestViewController(Swift File);

@interface TestViewController(Objective C File) : UIViewController

@end

Import 'ProjectName(Your Project Name)-Swift.h' in Objective C ".m" file

//TestViewController.m 
#import "TestViewController.h"

/*import ProjectName-Swift.h file to access Swift file here*/

#import "ProjectName-Swift.h"

How to prove that a problem is NP complete?

To show a problem is NP complete, you need to:

Show it is in NP

In other words, given some information C, you can create a polynomial time algorithm V that will verify for every possible input X whether X is in your domain or not.

Example

Prove that the problem of vertex covers (that is, for some graph G, does it have a vertex cover set of size k such that every edge in G has at least one vertex in the cover set?) is in NP:

  • our input X is some graph G and some number k (this is from the problem definition)

  • Take our information C to be "any possible subset of vertices in graph G of size k"

  • Then we can write an algorithm V that, given G, k and C, will return whether that set of vertices is a vertex cover for G or not, in polynomial time.

Then for every graph G, if there exists some "possible subset of vertices in G of size k" which is a vertex cover, then G is in NP.

Note that we do not need to find C in polynomial time. If we could, the problem would be in `P.

Note that algorithm V should work for every G, for some C. For every input there should exist information that could help us verify whether the input is in the problem domain or not. That is, there should not be an input where the information doesn't exist.

Prove it is NP Hard

This involves getting a known NP-complete problem like SAT, the set of boolean expressions in the form:

(A or B or C) and (D or E or F) and ...

where the expression is satisfiable, that is there exists some setting for these booleans, which makes the expression true.

Then reduce the NP-complete problem to your problem in polynomial time.

That is, given some input X for SAT (or whatever NP-complete problem you are using), create some input Y for your problem, such that X is in SAT if and only if Y is in your problem. The function f : X -> Y must run in polynomial time.

In the example above, the input Y would be the graph G and the size of the vertex cover k.

For a full proof, you'd have to prove both:

  • that X is in SAT => Y in your problem

  • and Y in your problem => X in SAT.

marcog's answer has a link with several other NP-complete problems you could reduce to your problem.

Footnote: In step 2 (Prove it is NP-hard), reducing another NP-hard (not necessarily NP-complete) problem to the current problem will do, since NP-complete problems are a subset of NP-hard problems (that are also in NP).

What do the makefile symbols $@ and $< mean?

The $@ and $< are special macros.

Where:

$@ is the file name of the target.

$< is the name of the first dependency.

Return list of items in list greater than some value

You can use a list comprehension:

[x for x in j if x >= 5]

How can I read a whole file into a string variable

If you just want the content as string, then the simple solution is to use the ReadFile function from the io/ioutil package. This function returns a slice of bytes which you can easily convert to a string.

package main

import (
    "fmt"
    "io/ioutil"
)

func main() {
    b, err := ioutil.ReadFile("file.txt") // just pass the file name
    if err != nil {
        fmt.Print(err)
    }

    fmt.Println(b) // print the content as 'bytes'

    str := string(b) // convert content to a 'string'

    fmt.Println(str) // print the content as a 'string'
}

What does 'synchronized' mean?

What is the synchronized keyword?

Threads communicate primarily by sharing access to fields and the objects reference fields refer to. This form of communication is extremely efficient, but makes two kinds of errors possible: thread interference and memory consistency errors. The tool needed to prevent these errors is synchronization.

Synchronized blocks or methods prevents thread interference and make sure that data is consistent. At any point of time, only one thread can access a synchronized block or method (critical section) by acquiring a lock. Other thread(s) will wait for release of lock to access critical section.

When are methods synchronized?

Methods are synchronized when you add synchronized to method definition or declaration. You can also synchronize a particular block of code with-in a method.

What does it mean pro grammatically and logically?

It means that only one thread can access critical section by acquiring a lock. Unless this thread release this lock, all other thread(s) will have to wait to acquire a lock. They don't have access to enter critical section with out acquiring lock.

This can't be done with a magic. It's programmer responsibility to identify critical section(s) in application and guard it accordingly. Java provides a framework to guard your application, but where and what all sections to be guarded is the responsibility of programmer.

More details from java documentation page

Intrinsic Locks and Synchronization:

Synchronization is built around an internal entity known as the intrinsic lock or monitor lock. Intrinsic locks play a role in both aspects of synchronization: enforcing exclusive access to an object's state and establishing happens-before relationships that are essential to visibility.

Every object has an intrinsic lock associated with it. By convention, a thread that needs exclusive and consistent access to an object's fields has to acquire the object's intrinsic lock before accessing them, and then release the intrinsic lock when it's done with them.

A thread is said to own the intrinsic lock between the time it has acquired the lock and released the lock. As long as a thread owns an intrinsic lock, no other thread can acquire the same lock. The other thread will block when it attempts to acquire the lock.

When a thread releases an intrinsic lock, a happens-before relationship is established between that action and any subsequent acquisition of the same lock.

Making methods synchronized has two effects:

First, it is not possible for two invocations of synchronized methods on the same object to interleave.

When one thread is executing a synchronized method for an object, all other threads that invoke synchronized methods for the same object block (suspend execution) until the first thread is done with the object.

Second, when a synchronized method exits, it automatically establishes a happens-before relationship with any subsequent invocation of a synchronized method for the same object.

This guarantees that changes to the state of the object are visible to all threads.

Look for other alternatives to synchronization in :

Avoid synchronized(this) in Java?

how to get the value of a textarea in jquery?

You can also get the value by element's name attribute.

var message = $("#formId textarea[name=message]").val();

Why is this HTTP request not working on AWS Lambda?

enter image description here

Add above code in API gateway under GET-Integration Request> mapping section.

Custom sort function in ng-repeat

To include the direction along with the orderBy function:

ng-repeat="card in cards | orderBy:myOrderbyFunction():defaultSortDirection"

where

defaultSortDirection = 0; // 0 = Ascending, 1 = Descending

ng-repeat: access key and value for each object in array of objects

In fact, your data is not well design. You'd better use something like :

$scope.steps = [
    {stepName: "companyName", isComplete: true},
    {stepName: "businessType", isComplete: true},
    {stepName: "physicalAddress", isComplete: true}
];

Then it is easy to do what you want :

<div ng-repeat="step in steps">
 Step {{step.stepName}} status : {{step.isComplet}}
</div>

Example: http://jsfiddle.net/rX7ba/

The HTTP request is unauthorized with client authentication scheme 'Ntlm'

My problem was; None admin users were getting "the http request is unauthorized with client authentication scheme 'negotiate' asmx" on my asmx services.

I gived read/execute folder permissions for the none admin users and my problem was solved.

iOS: how to perform a HTTP POST request?

You can use NSURLConnection as follows:

  1. Set your NSURLRequest: Use requestWithURL:(NSURL *)theURL to initialise the request.

    If you need to specify a POST request and/or HTTP headers, use NSMutableURLRequest with

    • (void)setHTTPMethod:(NSString *)method
    • (void)setHTTPBody:(NSData *)data
    • (void)setValue:(NSString *)value forHTTPHeaderField:(NSString *)field
  2. Send your request in 2 ways using NSURLConnection:

    • Synchronously: (NSData *)sendSynchronousRequest:(NSURLRequest *)request returningResponse:(NSURLResponse **)response error:(NSError **)error

      This returns a NSData variable that you can process.

      IMPORTANT: Remember to kick off the synchronous request in a separate thread to avoid blocking the UI.

    • Asynchronously: (void)start

Don't forget to set your NSURLConnection's delegate to handle the connection as follows:

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [self.data setLength:0];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)d {
    [self.data appendData:d];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {
    [[[[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Error", @"")
                                 message:[error localizedDescription]
                                delegate:nil
                       cancelButtonTitle:NSLocalizedString(@"OK", @"") 
                       otherButtonTitles:nil] autorelease] show];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    NSString *responseText = [[NSString alloc] initWithData:self.data encoding:NSUTF8StringEncoding];

    // Do anything you want with it 

    [responseText release];
}

// Handle basic authentication challenge if needed
- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
    NSString *username = @"username";
    NSString *password = @"password";

    NSURLCredential *credential = [NSURLCredential credentialWithUser:username
                                                             password:password
                                                          persistence:NSURLCredentialPersistenceForSession];
    [[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];
}

Compare two objects' properties to find differences?

Yes. Use Reflection. With Reflection, you can do things like:

//given object of some type
object myObjectFromSomewhere;
Type myObjOriginalType = myObjectFromSomewhere.GetType();
PropertyInfo[] myProps = myObjOriginalType.GetProperties();

And then you can use the resulting PropertyInfo classes to compare all manner of things.

Tokenizing strings in C

Here's an example of strtok usage, keep in mind that strtok is destructive of its input string (and therefore can't ever be used on a string constant

char *p = strtok(str, " ");
while(p != NULL) {
    printf("%s\n", p);
    p = strtok(NULL, " ");
}

Basically the thing to note is that passing a NULL as the first parameter to strtok tells it to get the next token from the string it was previously tokenizing.

PowerShell array initialization

The original example returns an error because the array is created empty, then you try to access the nth element to assign it a value.

The are a number of creative answers here, many I didn't know before reading this post. All are fine for a small array, but as n0rd points out, there are significant differences in performance.

Here I use Measure-Command to find out how long each initialization takes. As you might guess, any approach that uses an explicit PowerShell loop is slower than those that use .Net constructors or PowerShell operators (which would be compiled in IL or native code).

Summary

  • New-Object and @(somevalue)*n are fast (around 20k ticks for 100k elements).
  • Creating an array with the range operator n..m is 10x slower (200k ticks).
  • Using an ArrayList with the Add() method is 1000x slower than the baseline (20M ticks), as is looping through an already-sized array using for() or ForEach-Object (a.k.a. foreach,%).
  • Appending with += is the worst (2M ticks for just 1000 elements).

Overall, I'd say array*n is "best" because:

  • It's fast.
  • You can use any value, not just the default for the type.
  • You can create repeating values (to illustrate, type this at the powershell prompt: (1..10)*10 -join " " or ('one',2,3)*3)
  • Terse syntax.

The only drawback:

  • Non-obvious. If you haven't seen this construct before, it's not apparent what it does.

But keep in mind that for many cases where you would want to initialize the array elements to some value, then a strongly-typed array is exactly what you need. If you're initializing everything to $false, then is the array ever going to hold anything other than $false or $true? If not, then New-Object type[] n is the "best" approach.

Testing

Create and size a default array, then assign values:

PS> Measure-Command -Expression {$a = new-object object[] 100000} | Format-List -Property "Ticks"
Ticks : 20039

PS> Measure-Command -Expression {for($i=0; $i -lt $a.Length;$i++) {$a[$i] = $false}} | Format-List -Property "Ticks"
Ticks : 28866028

Creating an array of Boolean is bit little slower than and array of Object:

PS> Measure-Command -Expression {$a = New-Object bool[] 100000} | Format-List -Property "Ticks"
Ticks : 130968

It's not obvious what this does, the documentation for New-Object just says that the second parameter is an argument list which is passed to the .Net object constructor. In the case of arrays, the parameter evidently is the desired size.

Appending with +=

PS> $a=@()
PS> Measure-Command -Expression { for ($i=0; $i -lt 100000; $i++) {$a+=$false} } | Format-List -Property "Ticks"

I got tired of waiting for that to complete, so ctrl+c then:

PS> $a=@()
PS> Measure-Command -Expression { for ($i=0; $i -lt    100; $i++) {$a+=$false} } | Format-List -Property "Ticks"
Ticks : 147663
PS> $a=@()
PS> Measure-Command -Expression { for ($i=0; $i -lt   1000; $i++) {$a+=$false} } | Format-List -Property "Ticks"
Ticks : 2194398

Just as (6 * 3) is conceptually similar to (6 + 6 + 6), so ($somearray * 3) ought to give the same result as ($somearray + $somearray + $somearray). But with arrays, + is concatenation rather than addition.

If $array+=$element is slow, you might expect $array*$n to also be slow, but it's not:

PS> Measure-Command -Expression { $a = @($false) * 100000 } | Format-List -Property "Ticks"
Ticks : 20131

Just like Java has a StringBuilder class to avoid creating multiple objects when appending, so it seems PowerShell has an ArrayList.

PS> $al = New-Object System.Collections.ArrayList
PS> Measure-Command -Expression { for($i=0; $i -lt 1000; $i++) {$al.Add($false)} } | Format-List -Property "Ticks"
Ticks : 447133
PS> $al = New-Object System.Collections.ArrayList
PS> Measure-Command -Expression { for($i=0; $i -lt 10000; $i++) {$al.Add($false)} } | Format-List -Property "Ticks"
Ticks : 2097498
PS> $al = New-Object System.Collections.ArrayList
PS> Measure-Command -Expression { for($i=0; $i -lt 100000; $i++) {$al.Add($false)} } | Format-List -Property "Ticks"
Ticks : 19866894

Range operator, and Where-Object loop:

PS> Measure-Command -Expression { $a = 1..100000 } | Format-List -Property "Ticks"
Ticks : 239863
Measure-Command -Expression { $a | % {$false} } | Format-List -Property "Ticks"
Ticks : 102298091

Notes:

  • I nulled the variable between each run ($a=$null).
  • Testing was on a tablet with Atom processor; you would probably see faster speeds on other machines. [edit: About twice as fast on a desktop machine.]
  • There was a fair bit of variation when I tried multiple runs. Look for the orders of magnitude rather than exact numbers.
  • Testing was with PowerShell 3.0 in Windows 8.

Acknowledgements

Thanks to @halr9000 for array*n, @Scott Saad and Lee Desmond for New-Object, and @EBGreen for ArrayList.

Thanks to @n0rd for getting me to think about performance.

Which header file do you include to use bool type in c in linux?

#include <stdbool.h>

For someone like me here to copy and paste.

Copy all the lines to clipboard

You should yank the text to the * or + registers:

gg"*yG

Explanation:

  • gg to get the cursor to the first character of the file
  • "*y to start a yank command to the register * from the first line, until...
  • G to go the end of the file

Subtracting Number of Days from a Date in PL/SQL

Use sysdate-1 to subtract one day from system date.

select sysdate, sysdate -1 from dual;

Output:

SYSDATE  SYSDATE-1
-------- ---------
22-10-13 21-10-13 

PDF to byte array and vice versa

None of these worked for us, possibly because our inputstream was bytes from a rest call, and not from a locally hosted pdf file. What worked was using RestAssured to read the PDF as an input stream, and then using Tika pdf reader to parse it and then call the toString() method.

import com.jayway.restassured.RestAssured;
import com.jayway.restassured.response.Response;
import com.jayway.restassured.response.ResponseBody;

import org.apache.tika.exception.TikaException;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.BodyContentHandler;
import org.apache.tika.parser.Parser;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;

            InputStream stream = response.asInputStream();
            Parser parser = new AutoDetectParser(); // Should auto-detect!
            ContentHandler handler = new BodyContentHandler();
            Metadata metadata = new Metadata();
            ParseContext context = new ParseContext();

            try {
                parser.parse(stream, handler, metadata, context);
            } finally {
                stream.close();
            }
            for (int i = 0; i < metadata.names().length; i++) {
                String item = metadata.names()[i];
                System.out.println(item + " -- " + metadata.get(item));
            }

            System.out.println("!!Printing pdf content: \n" +handler.toString());
            System.out.println("content type: " + metadata.get(Metadata.CONTENT_TYPE));

Uncaught Error: SECURITY_ERR: DOM Exception 18 when I try to set a cookie

You're most likely using this on a local file over the file:// URI scheme, which cannot have cookies set. Put it on a local server so you can use http://localhost.

Remove non-utf8 characters from string

Welcome to 2019 and the /u modifier in regex which will handle UTF-8 multibyte chars for you

If you only use mb_convert_encoding($value, 'UTF-8', 'UTF-8') you will still end up with non-printable chars in your string

This method will:

  • Remove all invalid UTF-8 multibyte chars with mb_convert_encoding
  • Remove all non-printable chars like \r, \x00 (NULL-byte) and other control chars with preg_replace

method:

function utf8_filter(string $value): string{
    return preg_replace('/[^[:print:]\n]/u', '', mb_convert_encoding($value, 'UTF-8', 'UTF-8'));
}

[:print:] match all printable chars and \n newlines and strip everything else

You can see the ASCII table below.. The printable chars range from 32 to 127, but newline \n is a part of the control chars which range from 0 to 31 so we have to add newline to the regex /[^[:print:]\n]/u

https://cdn.shopify.com/s/files/1/1014/5789/files/Standard-ASCII-Table_large.jpg?10669400161723642407

You can try to send strings through the regex with chars outside the printable range like \x7F (DEL), \x1B (Esc) etc. and see how they are stripped

function utf8_filter(string $value): string{
    return preg_replace('/[^[:print:]\n]/u', '', mb_convert_encoding($value, 'UTF-8', 'UTF-8'));
}

$arr = [
    'Danish chars'          => 'Hello from Denmark with æøå',
    'Non-printable chars'   => "\x7FHello with invalid chars\r \x00"
];

foreach($arr as $k => $v){
    echo "$k:\n---------\n";
    
    $len = strlen($v);
    echo "$v\n(".$len.")\n";
    
    $strip = utf8_decode(utf8_filter(utf8_encode($v)));
    $strip_len = strlen($strip);
    echo $strip."\n(".$strip_len.")\n\n";
    
    echo "Chars removed: ".($len - $strip_len)."\n\n\n";
}

https://www.tehplayground.com/q5sJ3FOddhv1atpR

adding text to an existing text element in javascript via DOM

remove .textContent from var t = document.getElementById("p").textContent;

_x000D_
_x000D_
var t = document.getElementById("p");_x000D_
var y = document.createTextNode("This just got added");_x000D_
_x000D_
t.appendChild(y);
_x000D_
<p id ="p">This is some text</p>
_x000D_
_x000D_
_x000D_

How do I find the install time and date of Windows?

You can simply check the creation date of Windows Folder (right click on it and check properties) :)

References with text in LaTeX

Have a look to this wiki: LaTeX/Labels and Cross-referencing:

The hyperref package automatically includes the nameref package, and a similarly named command. It inserts text corresponding to the section name, for example:

\section{MyFirstSection}
\label{marker}
\section{MySecondSection} In section \nameref{marker} we defined...

adb command not found in linux environment

Updating the path as listed above in ~/.bashrc makes other bash commands stop working altogether.

the easiest way I found is to use what eaykin did but link it your /bin.

sudo ln -s /android/platform-tools/adb /bin/adb

No restart is required just type following command :

adb devices

To make sure it's working.

Twitter - share button, but with image

Look into twitter cards.

The trick is not in the button but rather the page you are sharing. Twitter Cards pull the image from the meta tags similar to facebook sharing.

Example:

<meta name="twitter:card" content="summary_large_image">
<meta name="twitter:site" content="@site_username">
<meta name="twitter:title" content="Top 10 Things Ever">
<meta name="twitter:description" content="Up than 200 characters.">
<meta name="twitter:creator" content="@creator_username">
<meta name="twitter:image" content="http://placekitten.com/250/250">
<meta name="twitter:domain" content="YourDomain.com">

Table Height 100% inside Div element

Not possible without assigning height value to div.

Add this

body, html{height:100%}
div{height:100%}
table{background:green; width:450px}    ?

DEMO

Selecting fields from JSON output

Assuming you are dealing with a JSON-string in the input, you can parse it using the json package, see the documentation.

In the specific example you posted you would need

x = json.loads("""{
 "accountWide": true,
 "criteria": [
     {
         "description": "some description",
         "id": 7553,
         "max": 1,
         "orderIndex": 0
     }
  ]
 }""")
description = x['criteria'][0]['description']
id = x['criteria'][0]['id']
max = x['criteria'][0]['max']

DOUBLE vs DECIMAL in MySQL

"are there any issue we should expect from only storing and retreiving a money amount in a DOUBLE column ?"

It sounds like no rounding errors can be produced in your scenario and if there were, they would be truncated by the conversion to BigDecimal.

So I would say no.

However, there is no guarantee that some change in the future will not introduce a problem.

How to make GREP select only numeric values?

You can use Perl style regular expressions as well. A digit is just \d then.

grep -Po "\\d+" filename

-P Interpret PATTERNS as Perl-compatible regular expressions (PCREs).

-o Print only the matched (non-empty) parts of a matching line, with each such part on a separate output line.

How to install XCODE in windows 7 platform?

X-code is primarily made for OS-X or iPhone development on Mac systems. Versions for Windows are not available. However this might help!

There is no way to get Xcode on Windows; however you can use a different SDK like Corona instead although it will not use Objective-C (I believe it uses Lua). I have however heard that it is horrible to use.

Source: classroomm.com

vim - How to delete a large block of text without counting the lines?

There are several possibilities, what's best depends on the text you work on.

Two possibilities come to mind:

  • switch to visual mode (V, S-V, ...), select the text with cursor movement and press d
  • delete a whole paragraph with: dap

Python urllib2: Receive JSON response from url

Though I guess it has already answered I would like to add my little bit in this

import json
import urllib2
class Website(object):
    def __init__(self,name):
        self.name = name 
    def dump(self):
     self.data= urllib2.urlopen(self.name)
     return self.data

    def convJSON(self):
         data=  json.load(self.dump())
     print data

domain = Website("https://example.com")
domain.convJSON()

Note : object passed to json.load() should support .read() , therefore urllib2.urlopen(self.name).read() would not work . Doamin passed should be provided with protocol in this case http

Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?

In Python 2.x, it is not guaranteed at all:

>>> False = 5
>>> 0 == False
False

So it could change. In Python 3.x, True, False, and None are reserved words, so the above code would not work.

In general, with booleans you should assume that while False will always have an integer value of 0 (so long as you don't change it, as above), True could have any other value. I wouldn't necessarily rely on any guarantee that True==1, but on Python 3.x, this will always be the case, no matter what.

How do you display code snippets in MS Word preserving format and syntax highlighting?

You can also use SciTE to paste code if you don't want to install heavy IDEs and then download plugins for all the code you're making. Simply choose your language from the language menu, type your code, high-light code, select Edit->Copy as RTF, paste into Word with formatting (default paste).

SciTE supports the following languages but probably has support for others: Abaqus*, Ada, ANS.1 MIB definition files*, APDL, Assembler (NASM, MASM), Asymptote*, AutoIt*, Avenue*, Batch files (MS-DOS), Baan*, Bash*, BlitzBasic*, Bullant*, C/C++/C#, Clarion, cmake*, conf (Apache), CSound, CSS*, D, diff files*, E-Script*, Eiffel*, Erlang*, Flagship (Clipper / XBase), Flash (ActionScript), Fortran*, Forth*, GAP*, Gettext, Haskell, HTML*, HTML with embedded JavaScript, VBScript, PHP and ASP*, Gui4Cli*, IDL - both MSIDL and XPIDL*, INI, properties* and similar, InnoSetup*, Java*, JavaScript*, LISP*, LOT*, Lout*, Lua*, Make, Matlab*, Metapost*, MMIXAL, MSSQL, nnCron, NSIS*, Objective Caml*, Opal, Octave*, Pascal/Delphi*, Perl, most of it except for some ambiguous cases*, PL/M*, Progress*, PostScript*, POV-Ray*, PowerBasic*, PowerShell*, PureBasic*, Python*, R*, Rebol*, Ruby*, Scheme*, scriptol*, Specman E*, Spice, Smalltalk, SQL and PLSQL, TADS3*, TeX and LaTeX, Tcl/Tk*, VB and VBScript*, Verilog*, VHDL*, XML*, YAML*.

How to pass multiple parameters in json format to a web service using jquery?

This is a stab in the dark, but maybe do you need to wrap your JSON arguments; like say something like this:

data: "{'Ids':[{'Id1':'2'},{'Id2':'2'}]}"

Make sure your JSON is properly formed?

how to get all child list from Firebase android

If you use Kotlin, the next one is a good solution:

myRef.addListenerForSingleValueEvent(object : ValueEventListener {
  override fun onDataChange(dataSnapshot: DataSnapshot) {
      val list = dataSnapshot.children.map { it.getValue(YourClass::class.java)!! }
      Log.d("TAG", "Value is: $list")
}

How do I change the default index page in Apache?

I recommend using .htaccess. You only need to add:

DirectoryIndex home.php

or whatever page name you want to have for it.

EDIT: basic htaccess tutorial.

1) Create .htaccess file in the directory where you want to change the index file.

  • no extension
  • . in front, to ensure it is a "hidden" file

Enter the line above in there. There will likely be many, many other things you will add to this (AddTypes for webfonts / media files, caching for headers, gzip declaration for compression, etc.), but that one line declares your new "home" page.

2) Set server to allow reading of .htaccess files (may only be needed on your localhost, if your hosting servce defaults to allow it as most do)

Assuming you have access, go to your server's enabled site location. I run a Debian server for development, and the default site setup is at /etc/apache2/sites-available/default for Debian / Ubuntu. Not sure what server you run, but just search for "sites-available" and go into the "default" document. In there you will see an entry for Directory. Modify it to look like this:

<Directory /var/www/>
    Options Indexes FollowSymLinks MultiViews
    AllowOverride None
    Order allow,deny
    allow from all
</Directory>

Then restart your apache server. Again, not sure about your server, but the command on Debian / Ubuntu is:

sudo service apache2 restart

Technically you only need to reload, but I restart just because I feel safer with a full refresh like that.

Once that is done, your site should be reading from your .htaccess file, and you should have a new default home page! A side note, if you have a sub-directory that runs a site (like an admin section or something) and you want to have a different "home page" for that directory, you can just plop another .htaccess file in that sub-site's root and it will overwrite the declaration in the parent.

How to include a Font Awesome icon in React's render()

https://github.com/FortAwesome/react-fontawesome

install fontawesome & react-fontawesome

$ npm i --save @fortawesome/fontawesome
$ npm i --save @fortawesome/react-fontawesome
$ npm i --save @fortawesome/fontawesome-free-solid
$ npm i --save @fortawesome/fontawesome-free-regular
$ npm i --save @fortawesome/fontawesome-svg-core

then in your component

import React, { Component } from 'react';
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
import { faCheckSquare, faCoffee } from '@fortawesome/fontawesome-free-solid'
import './App.css';

class App extends Component {
  render() {
    return (
      <div className="App">
        <h1>
          <FontAwesomeIcon icon={faCoffee} />
        </h1>
      </div>
    );
  }
}

export default App;

Make div 100% Width of Browser Window

.myDiv {
    background-color: red;
    width: 100%;
    min-height: 100vh;
    max-height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    margin: 0 auto;
}

Basically, we're fixing the div's position regardless of it's parent, and then position it using margin: 0 auto; and settings its position at the top left corner.

403 Access Denied on Tomcat 8 Manager App without prompting for user/password

The solution that worked for me is edit context.xml files in both $CATALINA_HOME/webapps/manager/META-INF and $CATALINA_HOME/webapps/host-manager/META-INF where my ip is 123.123.123.123.

<Context antiResourceLocking="false" privileged="true" >
  <Valve className="org.apache.catalina.valves.RemoteAddrValve"
         allow="127\.\d+\.\d+\.\d+|::1|0:0:0:0:0:0:0:1|123.123.123.123" />
</Context>

I installed Tomcat 8.5 on Ubuntu and edited $CATALINA_HOME/conf/tomcat-users.xml:

<role rolename="admin-gui"/>
<role rolename="manager-gui"/>
<user username="myuser" password="mypass" roles="admin-gui,manager-gui"/>

However, I still couldn't access both Tomcat Web Application Manager (localhost:8080/manager/html) and Tomcat Virtual Host Manager (localhost:8080/host-manager/html) until I edited context.xml files.

How do I make a dotted/dashed line in Android?

I have custom a dashline which support horizontal&verical dash line . code below:

public class DashedLineView extends View
{
private float density;
private Paint paint;
private Path path;
private PathEffect effects;

public DashedLineView(Context context)
{
    super(context);
    init(context);
}

public DashedLineView(Context context, AttributeSet attrs)
{
    super(context, attrs);
    init(context);
}

public DashedLineView(Context context, AttributeSet attrs, int defStyle)
{
    super(context, attrs, defStyle);
    init(context);
}

private void init(Context context)
{
    density = DisplayUtil.getDisplayDensity(context);
    paint = new Paint();
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(density * 4);
    //set your own color
    paint.setColor(context.getResources().getColor(R.color.XXX));
    path = new Path();
    //array is ON and OFF distances in px (4px line then 2px space)
    effects = new DashPathEffect(new float[] { 4, 2, 4, 2 }, 0);

}

@Override
protected void onDraw(Canvas canvas)
{
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    paint.setPathEffect(effects);
    int measuredHeight = getMeasuredHeight();
    int measuredWidth = getMeasuredWidth();
    if (measuredHeight <= measuredWidth)
    {
        // horizontal
        path.moveTo(0, 0);
        path.lineTo(measuredWidth, 0);
        canvas.drawPath(path, paint);
    }
    else
    {
        // vertical
        path.moveTo(0, 0);
        path.lineTo(0, measuredHeight);
        canvas.drawPath(path, paint);
    }

}
}

show distinct column values in pyspark dataframe: python

If you want to select ALL(columns) data as distinct frrom a DataFrame (df), then

df.select('*').distinct().show(10,truncate=False)

Adding options to select with javascript

Here you go:

for ( i = 12; i <= 100; i += 1 ) {
    option = document.createElement( 'option' );
    option.value = option.text = i;
    select.add( option );
}

Live demo: http://jsfiddle.net/mwPb5/


Update: Since you want to reuse this code, here's the function for it:

function initDropdownList( id, min, max ) {
    var select, i, option;

    select = document.getElementById( id );
    for ( i = min; i <= max; i += 1 ) {
        option = document.createElement( 'option' );
        option.value = option.text = i;
        select.add( option );
    }
}

Usage:

initDropdownList( 'mainSelect', 12, 100 );

Live demo: http://jsfiddle.net/mwPb5/1/

Get all child elements

Yes, you can achieve it by find_elements_by_css_selector("*") or find_elements_by_xpath(".//*").

However, this doesn't sound like a valid use case to find all children of an element. It is an expensive operation to get all direct/indirect children. Please further explain what you are trying to do. There should be a better way.

from selenium import webdriver

driver = webdriver.Firefox()
driver.get("http://www.stackoverflow.com")

header = driver.find_element_by_id("header")

# start from your target element, here for example, "header"
all_children_by_css = header.find_elements_by_css_selector("*")
all_children_by_xpath = header.find_elements_by_xpath(".//*")

print 'len(all_children_by_css): ' + str(len(all_children_by_css))
print 'len(all_children_by_xpath): ' + str(len(all_children_by_xpath))

AWS : The config profile (MyName) could not be found

I ran into this problem when I moved to a new machine, carrying with me my AWS_DEFAULT_PROFILE environment variable, but not my ~/.aws directory. I couldn't get any awscli commands to work until I unset that variable or properly configured the named profile. But even the aws configure command was broken, making things a bit tricky. Assuming you have a Unix-like shell handy:

  • To determine what AWS-specific variables you might have in your session: env | grep AWS_
    • if you don't see AWS_DEFAULT_PROFILE listed here, this answer is not applicable to you.
  • To temporarily remove the default profile: unset AWS_DEFAULT_PROFILE
  • To configure that default profile: aws --profile foo configure
  • To reset the default profile variable: exec $SHELL
  • To test your new setup: aws iam get-user

How to remove an HTML element using Javascript?

Your JavaScript is correct. Your button has type="submit" which is causing the page to refresh.

How to catch a specific SqlException error?

Sort of, kind of. See Cause and Resolution of Database Engine Errors

class SqllErrorNumbers
{ 
   public const int BadObject = 208;
   public const int DupKey = 2627;
}

try
{
   ...
}
catch(SqlException sex)
{
   foreach(SqlErrorCode err in sex.Errors)
   {
      switch (err.Number)
      {
      case SqlErrorNumber.BadObject:...
      case SqllErrorNumbers.DupKey: ...
      }
   }
}

The problem though is that a good DAL layer would us TRY/CATCH inside the T-SQL (stored procedures), with a pattern like Exception handling and nested transactions. Alas a T-SQL TRY/CATCH block cannot raise the original error code, will have to raise a new error, with code above 50000. This makes client side handling a problem. In the next version of SQL Server there is a new THROW construct that allow to re-raise the original exception from T-SQL catch blocks.

JavaScript string encryption and decryption?

crypt.subtle AES-GCM, self-contained, tested:

async function aesGcmEncrypt(plaintext, password)

async function aesGcmDecrypt(ciphertext, password) 

https://gist.github.com/chrisveness/43bcda93af9f646d083fad678071b90a

How can I use a for each loop on an array?

A for each loop structure is more designed around the collection object. A For..Each loop requires a variant type or object. Since your "element" variable is being typed as a variant your "do_something" function will need to accept a variant type, or you can modify your loop to something like this:

Public Sub Example()

    Dim sArray(4) As String
    Dim i As Long

    For i = LBound(sArray) To UBound(sArray)
        do_something sArray(i)
    Next i

End Sub

Create a new workspace in Eclipse

I use File -> Switch Workspace -> Other... and type in my new workspace name.

New workspace composite screenshot (EDIT: Added the composite screen shot.)

Once in the new workspace, File -> Import... and under General choose "Existing Projects into Workspace. Press the Next button and then Browse for the old projects you would like to import. Check "Copy projects into workspace" to make a copy.

View contents of database file in Android Studio

In Android Studio 3 and above You Can See a "Device File Explorer" Section in Right-Bottom Side of Android Studio.

Open it, Then You Can See The File Tree, You Can Find an Application Databases In this Path:

/data/data/{package_name}/databases/

enter image description here

Disabling browser print options (headers, footers, margins) from page?

As @Awe had said above, this is the solution, that is confirmed to work in Chrome!!

Just make sure this is INSIDE the head tags:

<head>
<style media="print">
    @page 
    {
        size: auto;   /* auto is the initial value */
        margin: 0mm;  /* this affects the margin in the printer settings */
    }

    body 
    {
        background-color:#FFFFFF; 
        border: solid 1px black ;
        margin: 0px;  /* this affects the margin on the content before sending to printer */
   }
</style>
</head>

How to convert BigDecimal to Double in Java?

You can convert BigDecimal to double using .doubleValue(). But believe me, don't use it if you have currency manipulations. It should always be performed on BigDecimal objects directly. Precision loss in these calculations are big time problems in currency related calculations.

Linker Command failed with exit code 1 (use -v to see invocation), Xcode 8, Swift 3

I got the same issues while making a build of Ionic 1 project.

I was able to solve the issue after deleting the file CDVLogger.h & CDVLogger.m

Read binary file as string in Ruby

on os x these are the same for me... could this maybe be extra "\r" in windows?

in any case you may be better of with:

contents = File.read("e.tgz")
newFile = File.open("ee.tgz", "w")
newFile.write(contents)

How to write LaTeX in IPython Notebook?

The answer given by minrk (included for completeness) is good, but there is another way that I like even more.

You can also render an entire cell as LaTeX by typing %%latex as the first line in a text cell. This is usefull if you

  • want more control,
  • want more than just a math environment,
  • or if you are going to write a lot of math in one cell.

minrk's answer:


IPython notebook uses MathJax to render LaTeX inside html/markdown. Just put your LaTeX math inside $$.

$$c = \sqrt{a^2 + b^2}$$

sqrt

Or you can display LaTeX / Math output from Python, as seen towards the end of the notebook tour:

from IPython.display import display, Math, Latex
display(Math(r'F(k) = \int_{-\infty}^{\infty} f(x) e^{2\pi i k} dx'))

integral

CSS Transition doesn't work with top, bottom, left, right

Something that is not relevant for the OP, but maybe for someone else in the future:

For pixels (px), if the value is "0", the unit can be omitted: right: 0 and right: 0px both work.

However I noticed that in Firefox and Chrome this is not the case for the seconds unit (s). While transition: right 1s ease 0s works, transition: right 1s ease 0 (missing unit s for last value transition-delay) does not (it does work in Edge however).

In the following example, you'll see that right works for both 0px and 0, but transition only works for 0s and it doesn't work with 0.

_x000D_
_x000D_
#box {_x000D_
    border: 1px solid black;_x000D_
    height: 240px;_x000D_
    width: 260px;_x000D_
    margin: 50px;_x000D_
    position: relative;_x000D_
}_x000D_
.jump {_x000D_
    position: absolute;_x000D_
    width: 200px;_x000D_
    height: 50px;_x000D_
    color: white;_x000D_
    padding: 5px;_x000D_
}_x000D_
#jump1 {_x000D_
    background-color: maroon;_x000D_
    top: 0px;_x000D_
    right: 0px;_x000D_
    transition: right 1s ease 0s;_x000D_
}_x000D_
#jump2 {_x000D_
    background-color: green;_x000D_
    top: 60px;_x000D_
    right: 0;_x000D_
    transition: right 1s ease 0s;_x000D_
}_x000D_
#jump3 {_x000D_
    background-color: blue;_x000D_
    top: 120px;_x000D_
    right: 0px;_x000D_
    transition: right 1s ease 0;_x000D_
}_x000D_
#jump4 {_x000D_
    background-color: gray;_x000D_
    top: 180px;_x000D_
    right: 0;_x000D_
    transition: right 1s ease 0;_x000D_
}_x000D_
#box:hover .jump {_x000D_
    right: 50px;_x000D_
}
_x000D_
<div id="box">_x000D_
  <div class="jump" id="jump1">right: 0px<br>transition: right 1s ease 0s</div>_x000D_
  <div class="jump" id="jump2">right: 0<br>transition: right 1s ease 0s</div>_x000D_
  <div class="jump" id="jump3">right: 0px<br>transition: right 1s ease 0</div>_x000D_
  <div class="jump" id="jump4">right: 0<br>transition: right 1s ease 0</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Set initially selected item in Select list in Angular2

If you use

<select [ngModel]="object">
    <option *ngFor="let object of objects" [ngValue]="object">{{object.name}}</option>
</select>

You need to set the property object in you components class to the item from objects that you want to have pre-selected.

class MyComponent {
  object;
  objects = [{name: 'a'}, {name: 'b'}, {name: 'c'}];
  constructor() {
    this.object = this.objects[1];
  }
}

Installing jQuery?

Install JQuery with only JavaScript. This is not a very good solution if you are developing a website but it's great if you want JQuery in the JavaScript console of a random website that does not use JQuery already.

function loadScript(url, callback)
{
    // adding the script tag to the head as suggested before
   var head = document.getElementsByTagName('head')[0];
   var script = document.createElement('script');
   script.type = 'text/javascript';
   script.src = url;

   // then bind the event to the callback function 
   // there are several events for cross browser compatibility
   script.onreadystatechange = callback;
   script.onload = callback;

   // fire the loading
   head.appendChild(script);
}
loadScript("http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js")

loadScript function thanks to e-satis's answer to Include JavaScript file inside JavaScript file?

Execute combine multiple Linux commands in one line

If you want to execute each command only if the previous one succeeded, then combine them using the && operator:

cd /my_folder && rm *.jar && svn co path to repo && mvn compile package install

If one of the commands fails, then all other commands following it won't be executed.

If you want to execute all commands regardless of whether the previous ones failed or not, separate them with semicolons:

cd /my_folder; rm *.jar; svn co path to repo; mvn compile package install

In your case, I think you want the first case where execution of the next command depends on the success of the previous one.

You can also put all commands in a script and execute that instead:

#! /bin/sh
cd /my_folder \
&& rm *.jar \
&& svn co path to repo \
&& mvn compile package install

(The backslashes at the end of the line are there to prevent the shell from thinking that the next line is a new command; if you omit the backslashes, you would need to write the whole command in a single line.)

Save that to a file, for example myscript, and make it executable:

chmod +x myscript

You can now execute that script like other programs on the machine. But if you don't place it inside a directory listed in your PATH environment variable (for example /usr/local/bin, or on some Linux distributions ~/bin), then you will need to specify the path to that script. If it's in the current directory, you execute it with:

./myscript

The commands in the script work the same way as the commands in the first example; the next command only executes if the previous one succeeded. For unconditional execution of all commands, simply list each command on its own line:

#! /bin/sh
cd /my_folder
rm *.jar
svn co path to repo
mvn compile package install

In Java, how to find if first character in a string is upper case without regex

String yourString = "yadayada";
if (Character.isUpperCase(yourString.charAt(0))) {
    // print something
} else {
    // print something else
}

"Logging out" of phpMyAdmin?

The presence of the logout button depends on whether you are required to login or not, in the first place. This is tweakable in PHPMyAdmin config files.

Yet, I don't think that would change anything concerning your error message. You would need to fix the configuration for the message to go away.

Edit: this is the kind of solution you should be searching for. And here are plenty of others for you to explore ^^

replace all occurrences in a string

As explained here, you can use:

function replaceall(str,replace,with_this)
{
    var str_hasil ="";
    var temp;

    for(var i=0;i<str.length;i++) // not need to be equal. it causes the last change: undefined..
    {
        if (str[i] == replace)
        {
            temp = with_this;
        }
        else
        {
                temp = str[i];
        }

        str_hasil += temp;
    }

    return str_hasil;
}

... which you can then call using:

var str = "50.000.000";
alert(replaceall(str,'.',''));

The function will alert "50000000"

How to order by with union in SQL?

Why not use TOP X?

SELECT pass1.* FROM 
 (SELECT TOP 2000000 tblA.ID, tblA.CustomerName 
  FROM TABLE_A AS tblA ORDER BY 2) AS pass1
UNION ALL 
SELECT pass2.* FROM 
  (SELECT TOP 2000000 tblB.ID, tblB.CustomerName 
   FROM TABLE_B AS tblB ORDER BY 2) AS pass2

The TOP 2000000 is an arbitrary number, that is big enough to capture all of the data. Adjust as per your requirements.

Is it possible to format an HTML tooltip (title attribute)?

No. But there are other options out there like Overlib, and jQuery that allow you this freedom.

Personally, I would suggest jQuery as the route to take. It's typically very unobtrusive, and requires no additional setup in the markup of your site (with the exception of adding the jquery script tag in your <head>).

git clone: Authentication failed for <URL>

Go to > Control Panel\User Accounts\Credential Manager > Manage Windows Credentials and remove all generic credentials involving Git. This way you're resetting all the credentials; After this, when you clone, you'll be newly and securely asked your username and password instead of Authentication error. Similar logic can be applied for Mac users.

Hope it helps.

anaconda update all possible packages?

I solved this problem with conda and pip.

Firstly, I run:

conda uninstall qt and conda uninstall matplotlib and conda uninstall PyQt5

After that, I opened the cmd and run this code that

pip uninstall qt , pip uninstall matplotlib , pip uninstall PyQt5

Lastly, You should install matplotlib in pip by this code that pip install matplotlib

Builder Pattern in Effective Java

You need to declare the Builder inner class as static.

Consult some documentation for both non-static inner classes and static inner classes.

Basically the non-static inner classes instances cannot exist without attached outer class instance.

CSS rounded corners in IE8

I didnt know about css3pie.com, a very useful site after seeing this post:

But what after testing it out it didnt work for me either. However I found that wrapping it in the .PHP file worked fine. So instead of:

behavior: url(PIE.htc);

use this:

behavior: url(PIE.php);

I put mine in a folder called jquery, so mine was:

 behavior: url(jquery/PIE.php);

So goto their downloads or get it here:

http://css3pie.com/download-latest

And use their PHP file. Inside the PHP file it explains that some servers are not configured for proper .HTC usage. And that was the problem I had.

Try it! I did, it works. Hope this helps others out too.

How to remove the default arrow icon from a dropdown list (select element)?

Try This:

HTML:

<div class="customselect">
    <select>
    <option>2000</option>
    <option>2001</option>
    <option>2002</option>
    </select>
</div>

CSS:

.customselect {
    width: 70px;
    overflow: hidden;
}

.customselect select {
   width: 100px;
   -moz-appearance: none;
   -webkit-appearance: none;
   appearance: none;
}

How to use operator '-replace' in PowerShell to replace strings of texts with special characters and replace successfully

'-replace' does a regex search and you have special characters in that last one (like +) So you might use the non-regex replace version like this:

$c = $c.replace('AccountKey=eKkij32jGEIYIEqAR5RjkKgf4OTiMO6SAyF68HsR/Zd/KXoKvSdjlUiiWyVV2+OUFOrVsd7jrzhldJPmfBBpQA==','DdOegAhDmLdsou6Ms6nPtP37bdw6EcXucuT47lf9kfClA6PjGTe3CfN+WVBJNWzqcQpWtZf10tgFhKrnN48lXA==')

Windows equivalent of OS X Keychain?

If you are on windows got to control pannel -> windows Credentials

Recursively add the entire folder to a repository

There are times that I want to include my web service source codes along with its client-side project. Both of them have a separate git repositories. I am actually used to add all files using the command:

git add -A

But for some reason, it only adds the folder. Later on I found out that the server files also have its .git folder in it so the command doesn't work.

tl;dr: Make sure there are no .git folder inside the folder you want to stage.

Hash function for a string

Java's String implements hashCode like this:

public int hashCode()

Returns a hash code for this string. The hash code for a String object is computed as

     s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]

using int arithmetic, where s[i] is the ith character of the string, n is the length of the string, and ^ indicates exponentiation. (The hash value of the empty string is zero.) 

So something like this:

int HashTable::hash (string word) {
    int result = 0;
    for(size_t i = 0; i < word.length(); ++i) {
        result += word[i] * pow(31, i);
    }
    return result;
}

How to get Text BOLD in Alert or Confirm box?

The alert() dialog is not rendered in HTML, and thus the HTML you have embedded is meaningless.

You'd need to use a custom modal to achieve that.

How do you create a UIImage View Programmatically - Swift

First create UIImageView then add image in UIImageView .

    var imageView : UIImageView
    imageView  = UIImageView(frame:CGRectMake(10, 50, 100, 300));
    imageView.image = UIImage(named:"image.jpg")
    self.view.addSubview(imageView)

How to get time (hour, minute, second) in Swift 3 using NSDate?

Swift 4.2 & 5

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = Calendar.current

// *** Get components using current Local & Timezone ***
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date))

// *** define calendar components to use as well Timezone to UTC ***
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents([.hour, .year, .minute], from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Swift 3.0

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = NSCalendar.current

// *** Get components using current Local & Timezone ***    
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date as Date))

// *** define calendar components to use as well Timezone to UTC ***
let unitFlags = Set<Calendar.Component>([.hour, .year, .minute])
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents(unitFlags, from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Is it possible to display inline images from html in an Android TextView?

KOTLIN

There is also the possibility to use sufficientlysecure.htmltextview.HtmlTextView

Use like below in gradle files:

Project gradle file:

repositories {
    jcenter()
}

App gradle file:

dependencies {
implementation 'org.sufficientlysecure:html-textview:3.9'
}

Inside xml file replace your textView with:

<org.sufficientlysecure.htmltextview.HtmlTextView
      android:id="@+id/allNewsBlockTextView"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_margin="2dp"
      android:textColor="#000"
      android:textSize="18sp"
      app:htmlToString="@{detailsViewModel.selectedText}" />

Last line above is if you use Binding adapters where the code will be like:

@BindingAdapter("htmlToString")
fun bindTextViewHtml(textView: HtmlTextView, htmlValue: String) {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
    textView.setHtml(
        htmlValue,
        HtmlHttpImageGetter(textView, "n", true)
    );
    } else {
        textView.setHtml(
        htmlValue,
        HtmlHttpImageGetter(textView, "n", true)
        );
    }
}

More info from github page and a big thank you to the authors!!!!!

Can I get JSON to load into an OrderedDict?

Yes, you can. By specifying the object_pairs_hook argument to JSONDecoder. In fact, this is the exact example given in the documentation.

>>> json.JSONDecoder(object_pairs_hook=collections.OrderedDict).decode('{"foo":1, "bar": 2}')
OrderedDict([('foo', 1), ('bar', 2)])
>>> 

You can pass this parameter to json.loads (if you don't need a Decoder instance for other purposes) like so:

>>> import json
>>> from collections import OrderedDict
>>> data = json.loads('{"foo":1, "bar": 2}', object_pairs_hook=OrderedDict)
>>> print json.dumps(data, indent=4)
{
    "foo": 1,
    "bar": 2
}
>>> 

Using json.load is done in the same way:

>>> data = json.load(open('config.json'), object_pairs_hook=OrderedDict)

iPhone Debugging: How to resolve 'failed to get the task for process'?

The ad-hoc profile doesn't support debugging. You need to debug with a Development profile, and use the Ad-Hoc profile only for distributing non-debuggable copies.

jQuery Set Cursor Position in Text Area

Small modification to the code I found in bitbucket

Code is now able to select/highlight with start/end points if given 2 positions. Tested and works fine in FF/Chrome/IE9/Opera.

$('#field').caret(1, 9);

The code is listed below, only a few lines changed:

(function($) {
  $.fn.caret = function(pos) {
    var target = this[0];
    if (arguments.length == 0) { //get
      if (target.selectionStart) { //DOM
        var pos = target.selectionStart;
        return pos > 0 ? pos : 0;
      }
      else if (target.createTextRange) { //IE
        target.focus();
        var range = document.selection.createRange();
        if (range == null)
            return '0';
        var re = target.createTextRange();
        var rc = re.duplicate();
        re.moveToBookmark(range.getBookmark());
        rc.setEndPoint('EndToStart', re);
        return rc.text.length;
      }
      else return 0;
    }

    //set
    var pos_start = pos;
    var pos_end = pos;

    if (arguments.length > 1) {
        pos_end = arguments[1];
    }

    if (target.setSelectionRange) //DOM
      target.setSelectionRange(pos_start, pos_end);
    else if (target.createTextRange) { //IE
      var range = target.createTextRange();
      range.collapse(true);
      range.moveEnd('character', pos_end);
      range.moveStart('character', pos_start);
      range.select();
    }
  }
})(jQuery)

What is the difference between the operating system and the kernel?

Basically the Kernel is the interface between hardware (devices which are available in Computer) and Application software is like MS Office, Visual Studio, etc.

If I answer "what is an OS?" then the answer could be the same. Hence the kernel is the part & core of the OS.

The very sensitive tasks of an OS like memory management, I/O management, process management are taken care of by the kernel only.

So the ultimate difference is:

  1. Kernel is responsible for Hardware level interactions at some specific range. But the OS is like hardware level interaction with full scope of computer.
  2. Kernel triggers SystemCalls to tell the OS that this resource is available at this point of time. The OS is responsible to handle those system calls in order to utilize the resource.

How to convert String object to Boolean Object?

To get the boolean value of a String, try this:

public boolean toBoolean(String s) {
    try {
        return Boolean.parseBoolean(s); // Successfully converted String to boolean
    } catch(Exception e) {
        return null; // There was some error, so return null.
    }
}

If there is an error, it will return null. Example:

toBoolean("true"); // Returns true
toBoolean("tr.u;e"); // Returns null

How do I POST form data with UTF-8 encoding by using curl?

You CAN use UTF-8 in the POST request, all you need is to specify the charset in your request.

You should use this request:

curl -X POST -H "Content-Type: application/x-www-form-urlencoded; charset=utf-8" --data-ascii "content=derinhält&date=asdf" http://myserverurl.com/api/v1/somemethod

How to cut an entire line in vim and paste it?

Pressing Shift+v would select that entire line and pressing d would delete it.

You can also use dd, which is does not require you to enter visual mode.

uncaught syntaxerror unexpected token U JSON

Most common case of this error happening is using template that is generating the control then changing the way id and/or nameare being generated by 'overriding' default template with something like

@Html.TextBoxFor(m => m, new {Name = ViewData["Name"], id = ViewData["UniqueId"]} )

and then forgetting to change ValidationMessageFor to

@Html.ValidationMessageFor(m => m, null, new { data_valmsg_for = ViewData["Name"] })    

Hope this saves you some time.

Why is the console window closing immediately once displayed my output?

Add The Read method to show the output.

Console.WriteLine("Hello, World!");
Console.Read();
return 0;

What is the difference between Set and List?

List is an ordered sequence of elements whereas Set is a distinct list of elements which is unordered (thank you, Quinn Taylor).

List<E>:

An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list.

Set<E>:

A collection that contains no duplicate elements. More formally, sets contain no pair of elements e1 and e2 such that e1.equals(e2), and at most one null element. As implied by its name, this interface models the mathematical set abstraction.

Mongoose: Find, modify, save

findOne, modify fields & save

User.findOne({username: oldUsername})
  .then(user => {
    user.username = newUser.username;
    user.password = newUser.password;
    user.rights = newUser.rights;

    user.markModified('username');
    user.markModified('password');
    user.markModified('rights');

    user.save(err => console.log(err));
});

OR findOneAndUpdate

User.findOneAndUpdate({username: oldUsername}, {$set: { username: newUser.username, user: newUser.password, user:newUser.rights;}}, {new: true}, (err, doc) => {
    if (err) {
        console.log("Something wrong when updating data!");
    }
    console.log(doc);
});

Also see updateOne

Parsing json and searching through it

You can use jsonpipe if you just need the output (and more comfortable with command line):

cat bookmarks.json | jsonpipe |grep uri

HTML Upload MAX_FILE_SIZE does not appear to work

MAX_FILE_SIZE is in KB not bytes. You were right, it is in bytes. So, for a limit of 4MB convert 4MB in bytes {1024 * (1024 * 4)} try:

<input type="hidden" name="MAX_FILE_SIZE" value="4194304" /> 

enter image description here

Update 1

As explained by others, you will never get a warning for this. It's there just to impose a soft limit on server side.

Update 2

To answer your sub-question. Yes, there is a difference, you NEVER trust the user input. If you want to always impose a limit, you always must check its size. Don't trust what MAX_FILE_SIZE does, because it can be changed by a user. So, yes, you should check to make sure it's always up to or above the size you want it to be.

The difference is that if you have imposed a MAX_FILE_SIZE of 2MB and the user tries to upload a 4MB file, once they reach roughly the first 2MB of upload, the transfer will terminate and the PHP will stop accepting more data for that file. It will report the error on the files array.

Determine if Android app is being used for the first time

    /**
     * @author ALGO
     */
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.RandomAccessFile;
    import java.util.UUID;

    import android.content.Context;

    public class Util {
        // ===========================================================
        //
        // ===========================================================

        private static final String INSTALLATION = "INSTALLATION";

        public synchronized static boolean isFirstLaunch(Context context) {
            String sID = null;
            boolean launchFlag = false;
            if (sID == null) {
                File installation = new File(context.getFilesDir(), INSTALLATION);
                try {
                    if (!installation.exists()) {

                        writeInstallationFile(installation);
                    }
                    sID = readInstallationFile(installation);
launchFlag = true;
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
            }
            return launchFlag;
        }

        private static String readInstallationFile(File installation) throws IOException {
            RandomAccessFile f = new RandomAccessFile(installation, "r");// read only mode
            byte[] bytes = new byte[(int) f.length()];
            f.readFully(bytes);
            f.close();

            return new String(bytes);
        }

        private static void writeInstallationFile(File installation) throws IOException {
            FileOutputStream out = new FileOutputStream(installation);
            String id = UUID.randomUUID().toString();
            out.write(id.getBytes());
            out.close();
        }
    }

> Usage (in class extending android.app.Activity)

Util.isFirstLaunch(this);

Fastest way to remove first char in a String

The second option really isn't the same as the others - if the string is "///foo" it will become "foo" instead of "//foo".

The first option needs a bit more work to understand than the third - I would view the Substring option as the most common and readable.

(Obviously each of them as an individual statement won't do anything useful - you'll need to assign the result to a variable, possibly data itself.)

I wouldn't take performance into consideration here unless it was actually becoming a problem for you - in which case the only way you'd know would be to have test cases, and then it's easy to just run those test cases for each option and compare the results. I'd expect Substring to probably be the fastest here, simply because Substring always ends up creating a string from a single chunk of the original input, whereas Remove has to at least potentially glue together a start chunk and an end chunk.

what is the difference between uint16_t and unsigned short int incase of 64 bit processor?

uint16_t is guaranteed to be a unsigned integer that is 16 bits large

unsigned short int is guaranteed to be a unsigned short integer, where short integer is defined by the compiler (and potentially compiler flags) you are currently using. For most compilers for x86 hardware a short integer is 16 bits large.

Also note that per the ANSI C standard only the minimum size of 16 bits is defined, the maximum size is up to the developer of the compiler

Minimum Type Limits

Any compiler conforming to the Standard must also respect the following limits with respect to the range of values any particular type may accept. Note that these are lower limits: an implementation is free to exceed any or all of these. Note also that the minimum range for a char is dependent on whether or not a char is considered to be signed or unsigned.

Type Minimum Range

signed char     -127 to +127
unsigned char      0 to 255
short int     -32767 to +32767
unsigned short int 0 to 65535

How to include vars file in a vars file with ansible?

I know it's an old post but I had the same issue today, what I did is simple : changing my script that send my playbook from my local host to the server, before sending it with maven command, I did this :

cat common_vars.yml > vars.yml
cat snapshot_vars.yml >> vars.yml
# or 
#cat release_vars.yml >> vars.yml
mvn ....

How to delete a workspace in Eclipse?

It's possible to remove the workspace in Eclipse without much complications. The options are available under Preferences->General->Startup and Shutdown->Workspaces.

Note that this does not actually delete the files from the system, it simply removes it from the list of suggested workspaces. It changes the org.eclipse.ui.ide.prefs file in Jon's answer from within Eclipse.

How to convert an integer (time) to HH:MM:SS::00 in SQL Server 2008?

CREATE FUNCTION [dbo].[_ICAN_FN_IntToTime](@Num INT)
  RETURNS NVARCHAR(13)
AS
-------------------------------------------------------------------------------------------------------------------
--INVENTIVE:Keyvan ARYAEE-MOEEN
-------------------------------------------------------------------------------------------------------------------
  BEGIN
    DECLARE @Hour VARCHAR(10)=CAST(@Num/3600 AS  VARCHAR(2))
    DECLARE @Minute VARCHAR(10)=CAST((@Num-@Hour*3600)/60 AS  VARCHAR(2))
    DECLARE @Time VARCHAR(13)=CASE WHEN @Hour<10 THEN '0'+@Hour ELSE @Hour END+':'+CASE WHEN @Minute<10 THEN '0'+@Minute ELSE @Minute END+':00.000'
    RETURN @Time
  END
-------------------------------------------------------------------------------------------------------------------
--SELECT dbo._ICAN_FN_IntToTime(25500)
-------------------------------------------------------------------------------------------------------------------

how to set radio option checked onload with jQuery

Say you had radio buttons like these, for example:

<input type='radio' name='gender' value='Male'>
<input type='radio' name='gender' value='Female'>

And you wanted to check the one with a value of "Male" onload if no radio is checked:

$(function() {
    var $radios = $('input:radio[name=gender]');
    if($radios.is(':checked') === false) {
        $radios.filter('[value=Male]').prop('checked', true);
    }
});

How to download an entire directory and subdirectories using wget?

you can also use this command :

wget --mirror -pc --convert-links -P ./your-local-dir/ http://www.your-website.com

so that you get the exact mirror of the website you want to download

How do I remove a single file from the staging area (undo git add)?

git rm --cached FILE

,

git rm -r --cached CVS */CVS

Kubernetes how to make Deployment to update image

UPDATE 2019-06-24

Based on the @Jodiug comment if you have a 1.15 version you can use the command:

kubectl rollout restart deployment/demo

Read more on the issue:

https://github.com/kubernetes/kubernetes/issues/13488


Well there is an interesting discussion about this subject on the kubernetes GitHub project. See the issue: https://github.com/kubernetes/kubernetes/issues/33664

From the solutions described there, I would suggest one of two.

First

1.Prepare deployment

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: demo
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: demo
        image: registry.example.com/apps/demo:master
        imagePullPolicy: Always
        env:
        - name: FOR_GODS_SAKE_PLEASE_REDEPLOY
          value: 'THIS_STRING_IS_REPLACED_DURING_BUILD'

2.Deploy

sed -ie "s/THIS_STRING_IS_REPLACED_DURING_BUILD/$(date)/g" deployment.yml
kubectl apply -f deployment.yml

Second (one liner):

kubectl patch deployment web -p \
  "{\"spec\":{\"template\":{\"metadata\":{\"labels\":{\"date\":\"`date +'%s'`\"}}}}}"

Of course the imagePullPolicy: Always is required on both cases.

Import one schema into another new schema - Oracle

After you correct the possible dmp file problem, this is a way to ensure that the schema is remapped and imported appropriately. This will also ensure that the tablespace will change also, if needed:

impdp system/<password> SCHEMAS=user1 remap_schema=user1:user2 \
            remap_tablespace=user1:user2 directory=EXPORTDIR \
            dumpfile=user1.dmp logfile=E:\Data\user1.log

EXPORTDIR must be defined in oracle as a directory as the system user

create or replace directory EXPORTDIR as 'E:\Data';
grant read, write on directory EXPORTDIR to user2;

How to check if a network port is open on linux?

Netstat tool simply parses some /proc files like /proc/net/tcp and combines it with other files contents. Yep, it's highly platform specific, but for Linux-only solution you can stick with it. Linux kernel documentation describes these files in details so you can find there how to read them.

Please also notice your question is too ambiguous because "port" could also mean serial port (/dev/ttyS* and analogs), parallel port, etc.; I've reused understanding from another answer this is network port but I'd ask you to formulate your questions more accurately.

How to see PL/SQL Stored Function body in Oracle

SELECT text 
FROM all_source
where name = 'FGETALGOGROUPKEY'
order by line

alternatively:

select dbms_metadata.get_ddl('FUNCTION', 'FGETALGOGROUPKEY')
from dual;

How to restart ADB manually from Android Studio

If you are in Android Studio Open Terminal

 adb kill-server

press enter and again

 adb start-server

press enter

Otherwise

Open Command prompt and got android

sdk>platform-tools> adb kill-server

press enter

and again

adb start-server

press enter

How to not wrap contents of a div?

A combination of both float: left; white-space: nowrap; worked for me.

Each of them independently didn't accomplish the desired result.

TABLOCK vs TABLOCKX

This is more of an example where TABLOCK did not work for me and TABLOCKX did.

I have 2 sessions, that both use the default (READ COMMITTED) isolation level:

Session 1 is an explicit transaction that will copy data from a linked server to a set of tables in a database, and takes a few seconds to run. [Example, it deletes Questions] Session 2 is an insert statement, that simply inserts rows into a table that Session 1 doesn't make changes to. [Example, it inserts Answers].

(In practice there are multiple sessions inserting multiple records into the table, simultaneously, while Session 1 is running its transaction).

Session 1 has to query the table Session 2 inserts into because it can't delete records that depend on entries that were added by Session 2. [Example: Delete questions that have not been answered].

So, while Session 1 is executing and Session 2 tries to insert, Session 2 loses in a deadlock every time.

So, a delete statement in Session 1 might look something like this: DELETE tblA FROM tblQ LEFT JOIN tblX on ... LEFT JOIN tblA a ON tblQ.Qid = tblA.Qid WHERE ... a.QId IS NULL and ...

The deadlock seems to be caused from contention between querying tblA while Session 2, [3, 4, 5, ..., n] try to insert into tblA.

In my case I could change the isolation level of Session 1's transaction to be SERIALIZABLE. When I did this: The transaction manager has disabled its support for remote/network transactions.

So, I could follow instructions in the accepted answer here to get around it: The transaction manager has disabled its support for remote/network transactions

But a) I wasn't comfortable with changing the isolation level to SERIALIZABLE in the first place- supposedly it degrades performance and may have other consequences I haven't considered, b) didn't understand why doing this suddenly caused the transaction to have a problem working across linked servers, and c) don't know what possible holes I might be opening up by enabling network access.

There seemed to be just 6 queries within a very large transaction that are causing the trouble.

So, I read about TABLOCK and TabLOCKX.

I wasn't crystal clear on the differences, and didn't know if either would work. But it seemed like it would. First I tried TABLOCK and it didn't seem to make any difference. The competing sessions generated the same deadlocks. Then I tried TABLOCKX, and no more deadlocks.

So, in six places, all I needed to do was add a WITH (TABLOCKX).

So, a delete statement in Session 1 might look something like this: DELETE tblA FROM tblQ q LEFT JOIN tblX x on ... LEFT JOIN tblA a WITH (TABLOCKX) ON tblQ.Qid = tblA.Qid WHERE ... a.QId IS NULL and ...

Retrofit 2: Get JSON from Response body

use this

response.body().get(0).getUsername().toString();

Trim spaces from start and end of string

ECMAScript 5 supports trim and this has been implemented in Firefox.

trim - MDC