Programs & Examples On #C libraries

Build fat static library (device + simulator) using Xcode and SDK 4+

I actually just wrote my own script for this purpose. It doesn't use Xcode. (It's based off a similar script in the Gambit Scheme project.)

Basically, it runs ./configure and make three times (for i386, armv7, and armv7s), and combines each of the resulting libraries into a fat lib.

Linking static libraries to other static libraries

If you are using Visual Studio then yes, you can do this.

The library builder tool that comes with Visual Studio allows you to join libraries together on the command line. I don't know of any way to do this in the visual editor though.

lib.exe /OUT:compositelib.lib  lib1.lib lib2.lib

Undefined reference to pow( ) in C, despite including math.h

You need to link with the math library:

gcc -o sphere sphere.c -lm

The error you are seeing: error: ld returned 1 exit status is from the linker ld (part of gcc that combines the object files) because it is unable to find where the function pow is defined.

Including math.h brings in the declaration of the various functions and not their definition. The def is present in the math library libm.a. You need to link your program with this library so that the calls to functions like pow() are resolved.

How to Change color of Button in Android when Clicked?

public void onPressed(Button button, int drawable) {
            if (!isPressed) {
                button.setBackgroundResource(R.drawable.bg_circle);
                isPressed = true;
            } else {
                button.setBackgroundResource(drawable);
                isPressed = false;
            }
        }


    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.circle1:
                onPressed(circle1, R.drawable.bg_circle_gradient);
                break;
            case R.id.circle2:
                onPressed(circle2, R.drawable.bg_circle2_gradient);
                break;
            case R.id.circle3:
                onPressed(circle3, R.drawable.bg_circle_gradient3);
                break;
            case R.id.circle4:
                onPressed(circle4, R.drawable.bg_circle4_gradient);
                break;
            case R.id.circle5:
                onPressed(circle5, R.drawable.bg_circle5_gradient);
                break;
            case R.id.circle6:
                onPressed(circle6, R.drawable.bg_circle_gradient);
                break;
            case R.id.circle7:
                onPressed(circle7, R.drawable.bg_circle4_gradient);
                break;

        }

please try this, in this code i m trying to change the background of button on button click this works fine.

What is java pojo class, java bean, normal class?

POJO = Plain Old Java Object. It has properties, getters and setters for respective properties. It may also override Object.toString() and Object.equals().

Java Beans : See Wiki link.

Normal Class : Any java Class.

How do I use 3DES encryption/decryption in Java?

Here is a solution using the javax.crypto library and the apache commons codec library for encoding and decoding in Base64:

import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import org.apache.commons.codec.binary.Base64;

public class TrippleDes {

    private static final String UNICODE_FORMAT = "UTF8";
    public static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
    private KeySpec ks;
    private SecretKeyFactory skf;
    private Cipher cipher;
    byte[] arrayBytes;
    private String myEncryptionKey;
    private String myEncryptionScheme;
    SecretKey key;

    public TrippleDes() throws Exception {
        myEncryptionKey = "ThisIsSpartaThisIsSparta";
        myEncryptionScheme = DESEDE_ENCRYPTION_SCHEME;
        arrayBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
        ks = new DESedeKeySpec(arrayBytes);
        skf = SecretKeyFactory.getInstance(myEncryptionScheme);
        cipher = Cipher.getInstance(myEncryptionScheme);
        key = skf.generateSecret(ks);
    }


    public String encrypt(String unencryptedString) {
        String encryptedString = null;
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
            byte[] encryptedText = cipher.doFinal(plainText);
            encryptedString = new String(Base64.encodeBase64(encryptedText));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encryptedString;
    }


    public String decrypt(String encryptedString) {
        String decryptedText=null;
        try {
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] encryptedText = Base64.decodeBase64(encryptedString);
            byte[] plainText = cipher.doFinal(encryptedText);
            decryptedText= new String(plainText);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return decryptedText;
    }


    public static void main(String args []) throws Exception
    {
        TrippleDes td= new TrippleDes();

        String target="imparator";
        String encrypted=td.encrypt(target);
        String decrypted=td.decrypt(encrypted);

        System.out.println("String To Encrypt: "+ target);
        System.out.println("Encrypted String:" + encrypted);
        System.out.println("Decrypted String:" + decrypted);

    }

}

Running the above program results with the following output:

String To Encrypt: imparator
Encrypted String:FdBNaYWfjpWN9eYghMpbRA==
Decrypted String:imparator

Jquery UI tooltip does not support html content

another solution will be to grab the text inside the title tag & then use .html() method of jQuery to construct the content of the tooltip.

$(function() {
  $(document).tooltip({
    position: {
      using: function(position, feedback) {
        $(this).css(position);
        var txt = $(this).text();
        $(this).html(txt);
        $("<div>")
          .addClass("arrow")
          .addClass(feedback.vertical)
          .addClass(feedback.horizontal)
          .appendTo(this);
      }
    }
  });
});

Example: http://jsfiddle.net/hamzeen/0qwxfgjo/

How to get the first five character of a String

This is how you do it in 2020:

var s = "ABCDEFGH";
var first5 = s.AsSpan(0, 5);

A Span<T> points directly to the memory of the string, avoiding allocating a temporary string. Of course, any subsequent method asking for a string requires a conversion:

Console.WriteLine(first5.ToString());

Though, these days many .NET APIs allow for spans. Stick to them if possible!

Note: If targeting .NET Framework add a reference to the System.Memory package, but don't expect the same superb performance.

Can't draw Histogram, 'x' must be numeric

Note that you could as well plot directly from ce (after the comma removing) using the column name :

hist(ce$Weight)

(As opposed to using hist(ce[1]), which would lead to the same "must be numeric" error.)

This also works for a database query result.

Parsing JSON array with PHP foreach

$user->data is an array of objects. Each element in the array has a name and value property (as well as others).

Try putting the 2nd foreach inside the 1st.

foreach($user->data as $mydata)
{
    echo $mydata->name . "\n";
    foreach($mydata->values as $values)
    {
        echo $values->value . "\n";
    }
}

Git: add vs push vs commit

  • git add adds files to the Git index, which is a staging area for objects prepared to be commited.
  • git commit commits the files in the index to the repository, git commit -a is a shortcut to add all the modified tracked files to the index first.
  • git push sends all the pending changes to the remote repository to which your branch is mapped (eg. on GitHub).

In order to understand Git you would need to invest more effort than just glancing over the documentation, but it's definitely worth it. Just don't try to map Git commands directly to Subversion, as most of them don't have a direct counterpart.

javascript window.location in new tab

window.open('https://support.wwf.org.uk', '_blank');

The second parameter is what makes it open in a new window. Don't forget to read Jakob Nielsen's informative article :)

MISCONF Redis is configured to save RDB snapshots

If you're running MacOS and have recently upgraded to Catalina, you may need to run brew services restart redis as suggested in this issue.

DataGridView.Clear()

try:

datagrid.DataSource = null;
datagrid.DataBind();

Basically you will need to clear the datasource your binding to the grid.

Purpose of ESI & EDI registers?

In addition to the string operations (MOVS/INS/STOS/CMPS/SCASB/W/D/Q etc.) mentioned in the other answers, I wanted to add that there are also more "modern" x86 assembly instructions that implicitly use at least EDI/RDI:

The SSE2 MASKMOVDQU (and the upcoming AVX VMASKMOVDQU) instruction selectively write bytes from an XMM register to memory pointed to by EDI/RDI.

creating a new list with subset of list using index in python

Suppose

a = ['a', 'b', 'c', 3, 4, 'd', 6, 7, 8]

and the list of indexes is stored in

b= [0, 1, 2, 4, 6, 7, 8]

then a simple one-line solution will be

c = [a[i] for i in b]

How to style the parent element when hovering a child element?

I know it is an old question, but I just managed to do so without a pseudo child (but a pseudo wrapper).

If you set the parent to be with no pointer-events, and then a child div with pointer-events set to auto, it works:)
Note that <img> tag (for example) doesn't do the trick.
Also remember to set pointer-events to auto for other children which have their own event listener, or otherwise they will lose their click functionality.

_x000D_
_x000D_
div.parent {  _x000D_
    pointer-events: none;_x000D_
}_x000D_
_x000D_
div.child {_x000D_
    pointer-events: auto;_x000D_
}_x000D_
_x000D_
div.parent:hover {_x000D_
    background: yellow;_x000D_
}    
_x000D_
<div class="parent">_x000D_
  parent - you can hover over here and it won't trigger_x000D_
  <div class="child">hover over the child instead!</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Edit:
As Shadow Wizard kindly noted: it's worth to mention this won't work for IE10 and below. (Old versions of FF and Chrome too, see here)

An internal error occurred during: "Updating Maven Project". Unsupported IClasspathEntry kind=4

It helped in my case

rightclick project, remove maven nature mvn eclipse:clean (with project open in eclipse/STS) delete the project in eclipse (but do not delete the sources) Import existing Maven project

Hiding the address bar of a browser (popup)

Its not possible to hide address bar of browser.

How to Create Multiple Where Clause Query Using Laravel Eloquent?

Using pure Eloquent, implement it like so. This code returns all logged in users whose accounts are active. $users = \App\User::where('status', 'active')->where('logged_in', true)->get();

Use of *args and **kwargs

Here's an example that uses 3 different types of parameters.

def func(required_arg, *args, **kwargs):
    # required_arg is a positional-only parameter.
    print required_arg

    # args is a tuple of positional arguments,
    # because the parameter name has * prepended.
    if args: # If args is not empty.
        print args

    # kwargs is a dictionary of keyword arguments,
    # because the parameter name has ** prepended.
    if kwargs: # If kwargs is not empty.
        print kwargs

>>> func()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: func() takes at least 1 argument (0 given)

>>> func("required argument")
required argument

>>> func("required argument", 1, 2, '3')
required argument
(1, 2, '3')

>>> func("required argument", 1, 2, '3', keyword1=4, keyword2="foo")
required argument
(1, 2, '3')
{'keyword2': 'foo', 'keyword1': 4}

How do I create an array of strings in C?

A good way is to define a string your self.

#include <stdio.h>
typedef char string[]
int main() {
    string test = "string";
    return 0;
}

It's really that simple.

Entityframework Join using join method and lambdas

If you have configured navigation property 1-n I would recommend you to use:

var query = db.Categories                                  // source
   .SelectMany(c=>c.CategoryMaps,                          // join
      (c, cm) => new { Category = c, CategoryMaps = cm })  // project result
   .Select(x => x.Category);                               // select result

Much more clearer to me and looks better with multiple nested joins.

Remove trailing comma from comma-separated string

Check if str.charAt(str.length() -1) == ','. Then do str = str.substring(0, str.length()-1)

Sharing url link does not show thumbnail image on facebook

I ran into this and while I had the og:image (and others), I was missing og:url and og:type, so I added those and then it worked.

<meta property="og:url" content="<? 
 $url = 'https://' . $_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF']."?".$_SERVER['QUERY_STRING'];; 
echo htmlentities($url,ENT_QUOTES); ?>"/> 

What is default color for text in textview?

There is no default color. It means that every device can have own.

Using grep to help subset a data frame in R

You may also use the stringr package

library(dplyr)
library(stringr)
My.Data %>% filter(str_detect(x, '^G45'))

You may not use '^' (starts with) in this case, to obtain the results you need

Migration: Cannot add foreign key constraint

One thing that I think is missing from the answers on here, and please correct me if I am wrong, but the foreign keys need to be indexed on the pivot table. At least in mysql that seems to be the case.

public function up()
{
    Schema::create('image_post', function (Blueprint $table) {
        $table->engine = 'InnoDB';
        $table->increments('id');
        $table->integer('image_id')->unsigned()->index();
        $table->integer('post_id')->unsigned()->index();
        $table->timestamps();
    });

    Schema::table('image_post', function($table) {
        $table->foreign('image_id')->references('id')->on('image')->onDelete('cascade');
        $table->foreign('post_id')->references('id')->on('post')->onDelete('cascade');
    });

}

How do I remove duplicates from a C# array?

If you needed to sort it, then you could implement a sort that also removes duplicates.

Kills two birds with one stone, then.

React prevent event bubbling in nested components on click

I had issues getting event.stopPropagation() working. If you do too, try moving it to the top of your click handler function, that was what I needed to do to stop the event from bubbling. Example function:

  toggleFilter(e) {
    e.stopPropagation(); // If moved to the end of the function, will not work
    let target = e.target;
    let i = 10; // Sanity breaker

    while(true) {
      if (--i === 0) { return; }
      if (target.classList.contains("filter")) {
        target.classList.toggle("active");
        break;
      }
      target = target.parentNode;
    }
  }

Setting the Textbox read only property to true using JavaScript

Using asp.net, I believe you can do it this way :

myTextBox.Attributes.Add("readonly","readonly")

Reading e-mails from Outlook with Python through MAPI

I had the same issue. Combining various approaches from the internet (and above) come up with the following approach (checkEmails.py)

class CheckMailer:

        def __init__(self, filename="LOG1.txt", mailbox="Mailbox - Another User Mailbox", folderindex=3):
            self.f = FileWriter(filename)
            self.outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI").Folders(mailbox)
            self.inbox = self.outlook.Folders(folderindex)


        def check(self):                
        #===============================================================================
        # for i in xrange(1,100):                           #Uncomment this section if index 3 does not work for you
        #     try:
        #         self.inbox = self.outlook.Folders(i)     # "6" refers to the index of inbox for Default User Mailbox
        #         print "%i %s" % (i,self.inbox)            # "3" refers to the index of inbox for Another user's mailbox
        #     except:
        #         print "%i does not work"%i
        #===============================================================================

                self.f.pl(time.strftime("%H:%M:%S"))
                tot = 0                
                messages = self.inbox.Items
                message = messages.GetFirst()
                while message:
                    self.f.pl (message.Subject)
                    message = messages.GetNext()
                    tot += 1
                self.f.pl("Total Messages found: %i" % tot)
                self.f.pl("-" * 80)
                self.f.flush()

if __name__ == "__main__":
    mail = CheckMailer()
    for i in xrange(320):  # this is 10.6 hours approximately
            mail.check()
            time.sleep(120.00)

For concistency I include also the code for the FileWriter class (found in FileWrapper.py). I needed this because trying to pipe UTF8 to a file in windows did not work.

class FileWriter(object):
    '''
    convenient file wrapper for writing to files
    '''


    def __init__(self, filename):
        '''
        Constructor
        '''
        self.file = open(filename, "w")

    def pl(self, a_string):
        str_uni = a_string.encode('utf-8')
        self.file.write(str_uni)
        self.file.write("\n")

    def flush(self):
        self.file.flush()

How to test my servlet using JUnit

EDIT: Cactus is now a dead project: http://attic.apache.org/projects/jakarta-cactus.html


You may want to look at cactus.

http://jakarta.apache.org/cactus/

Project Description

Cactus is a simple test framework for unit testing server-side java code (Servlets, EJBs, Tag Libs, Filters, ...).

The intent of Cactus is to lower the cost of writing tests for server-side code. It uses JUnit and extends it.

Cactus implements an in-container strategy, meaning that tests are executed inside the container.

ORA-01031: insufficient privileges when selecting view

To use a view, the user must have the appropriate privileges but only for the view itself, not its underlying objects. However, if access privileges for the underlying objects of the view are removed, then the user no longer has access. This behavior occurs because the security domain that is used when a user queries the view is that of the definer of the view. If the privileges on the underlying objects are revoked from the view's definer, then the view becomes invalid, and no one can use the view. Therefore, even if a user has been granted access to the view, the user may not be able to use the view if the definer's rights have been revoked from the view's underlying objects.

Oracle Documentation http://docs.oracle.com/cd/B28359_01/network.111/b28531/authorization.htm#DBSEG98017

How can I assign an ID to a view programmatically?

You can just use the View.setId(integer) for this. In the XML, even though you're setting a String id, this gets converted into an integer. Due to this, you can use any (positive) Integer for the Views you add programmatically.

According to View documentation

The identifier does not have to be unique in this view's hierarchy. The identifier should be a positive number.

So you can use any positive integer you like, but in this case there can be some views with equivalent id's. If you want to search for some view in hierarchy calling to setTag with some key objects may be handy.

Credits to this answer.

How to trim a file extension from a String in JavaScript?

var fileName = "something.extension";
fileName.slice(0, -path.extname(fileName).length) // === "something"

Constructing pandas DataFrame from values in variables gives "ValueError: If using all scalar values, you must pass an index"

You could try:

df2 = pd.DataFrame.from_dict({'a':a,'b':b}, orient = 'index')

From the documentation on the 'orient' argument: If the keys of the passed dict should be the columns of the resulting DataFrame, pass ‘columns’ (default). Otherwise if the keys should be rows, pass ‘index’.

CSS3 Transition - Fade out effect

You forgot to add a position property to the .dummy-wrap class, and the top/left/bottom/right values don't apply to statically positioned elements (the default)

http://jsfiddle.net/dYBD2/2/

How to start debug mode from command prompt for apache tomcat server?

There are two ways to run tomcat in debug mode

  1. Using jdpa run

  2. Using JAVA_OPTS

First setup the environment. Then start the server using following commands.

_x000D_
_x000D_
export JPDA_ADDRESS=8000_x000D_
_x000D_
export JPDA_TRANSPORT=dt_socket_x000D_
_x000D_
%TOMCAT_HOME%/bin/catalina.sh jpda start_x000D_
_x000D_
sudo catalina.sh jpda start
_x000D_
_x000D_
_x000D_

refer this article for more information this is clearly define it

How do I show/hide a UIBarButtonItem?

In case the UIBarButtonItem has an image instead of the text in it you can do this to hide it: navigationBar.topItem.rightBarButtonItem.customView.alpha = 0.0;

conflicting types for 'outchar'

It's because you haven't declared outchar before you use it. That means that the compiler will assume it's a function returning an int and taking an undefined number of undefined arguments.

You need to add a prototype pf the function before you use it:

void outchar(char);  /* Prototype (declaration) of a function to be called */  int main(void) {     ... }  void outchar(char ch) {     ... } 

Note the declaration of the main function differs from your code as well. It's actually a part of the official C specification, it must return an int and must take either a void argument or an int and a char** argument.

Start / Stop a Windows Service from a non-Administrator user account

Windows Service runs using a local system account.It can start automatically as the user logs into the system or it can be started manually.However, a windows service say BST can be run using a particular user account on the machine.This can be done as follows:start services.msc and go to the properties of your windows service,BST.From there you can give the login parameters of the required user.Service then runs with that user account and no other user can run that service.

How can I decrypt a password hash in PHP?

Use the password_verify() function

if (password_vertify($inputpassword, $row['password'])) {
  print "Logged in";
else {
    print "Password Incorrect";
}

Python send POST with header

If we want to add custom HTTP headers to a POST request, we must pass them through a dictionary to the headers parameter.

Here is an example with a non-empty body and headers:

import requests
import json

url = 'https://somedomain.com'
body = {'name': 'Maryja'}
headers = {'content-type': 'application/json'}

r = requests.post(url, data=json.dumps(body), headers=headers)

Source

Parse RSS with jQuery

jFeed doesn't work in IE.

Use zRSSFeed. Had it working in 5 minutes

MySQL: Error Code: 1118 Row size too large (> 8126). Changing some columns to TEXT or BLOB

For MySQL 5.7 on Mac OS X El Capitan:

OS X provides example configuration files at /usr/local/mysql/support-files/my-default.cnf

To add variables, first stop the server and just copy above file to, /usr/local/mysql/etc/my.cnf

cmd : sudo cp /usr/local/mysql/support-files/my-default.cnf /usr/local/mysql/etc/my.cnf

NOTE: create 'etc' folder under 'mysql' in case it doesn't exists.

cmd : sudo mkdir /usr/local/mysql/etc

Once the my.cnf is created under etc. it's time to set variable inside that.

cmd: sudo nano my.cnf

set variables below [mysqld]

[mysqld]
innodb_log_file_size = 512M
innodb_strict_mode = 0

now start a server!

How to show matplotlib plots in python

Save the plot as png

plt.savefig("temp.png")

How to refer environment variable in POM.xml?

I was struggling with the same thing, running a shell script that set variables, then wanting to use the variables in the shared-pom. The goal was to have environment variables replace strings in my project files using the com.google.code.maven-replacer-plugin.

Using ${env.foo} or ${env.FOO} didn't work for me. Maven just wasn't finding the variable. What worked was passing the variable in as a command-line parameter in Maven. Here's the setup:

  1. Set the variable in the shell script. If you're launching Maven in a sub-script, make sure the variable is getting set, e.g. using source ./maven_script.sh to call it from the parent script.

  2. In shared-pom, create a command-line param that grabs the environment variable:

<plugin>
  ...
  <executions>
    <executions>
    ...
      <execution>
      ...
        <configuration>
          <param>${foo}</param> <!-- Note this is *not* ${env.foo} -->
        </configuration>
  1. In com.google.code.maven-replacer-plugin, make the replacement value ${foo}.

  2. In my shell script that calls maven, add this to the command: -Dfoo=$foo

Determining Referer in PHP

What I have found best is a CSRF token and save it in the session for links where you need to verify the referrer.

So if you are generating a FB callback then it would look something like this:

$token = uniqid(mt_rand(), TRUE);
$_SESSION['token'] = $token;
$url = "http://example.com/index.php?token={$token}";

Then the index.php will look like this:

if(empty($_GET['token']) || $_GET['token'] !== $_SESSION['token'])
{
    show_404();
} 

//Continue with the rest of code

I do know of secure sites that do the equivalent of this for all their secure pages.

UnsupportedClassVersionError: JVMCFRE003 bad major version in WebSphere AS 7

I was getting this error in websphere 8.5:

java.lang.UnsupportedClassVersionError: JVMCFRE003 bad major version; class=com/xxx/Whatever, offset=6

I had my project JDK level set at 1.7 in eclipse and was8 by default runs on JDK 1.6 so there was a clash. I had to install the optional SDK 1.7 to my websphere server and then the problem went away. I guess I could have also set my project level down to 1.6 in eclipse but I wanted to code to 1.7.

How can I add an item to a SelectList in ASP.net MVC

private SelectList AddFirstItem(SelectList list)
        {
            List<SelectListItem> _list = list.ToList();
            _list.Insert(0, new SelectListItem() { Value = "-1", Text = "This Is First Item" });
            return new SelectList((IEnumerable<SelectListItem>)_list, "Value", "Text");
        }

This Should do what you need ,just send your selectlist and it will return a select list with an item in index 0

You can custome the text,value or even the index of the item you need to insert

How to print the contents of RDD?

You can convert your RDD to a DataFrame then show() it.

// For implicit conversion from RDD to DataFrame
import spark.implicits._

fruits = sc.parallelize([("apple", 1), ("banana", 2), ("orange", 17)])

// convert to DF then show it
fruits.toDF().show()

This will show the top 20 lines of your data, so the size of your data should not be an issue.

+------+---+                                                                    
|    _1| _2|
+------+---+
| apple|  1|
|banana|  2|
|orange| 17|
+------+---+

How to get Domain name from URL using jquery..?

This worked for me.

http://tech-blog.maddyzone.com/javascript/get-current-url-javascript-jquery

$(location).attr('host');                        www.test.com:8082
$(location).attr('hostname');                    www.test.com
$(location).attr('port');                        8082
$(location).attr('protocol');                    http:
$(location).attr('pathname');                    index.php
$(location).attr('href');                        http://www.test.com:8082/index.php#tab2
$(location).attr('hash');                       #tab2
$(location).attr('search');                     ?foo=123

START_STICKY and START_NOT_STICKY

KISS answer

Difference:

START_STICKY

the system will try to re-create your service after it is killed

START_NOT_STICKY

the system will not try to re-create your service after it is killed


Standard example:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return START_STICKY;
}

How can I determine if a date is between two dates in Java?

you can use getTime() and compare the returned long UTC values.

EDIT if you are sure you'll not have to deal with dates before 1970, not sure how it will behave in that case.

C# Creating and using Functions

static void Main(string[] args)
    {
        Console.WriteLine("geef een leeftijd");
        int a = Convert.ToInt32(Console.ReadLine());

        Console.WriteLine("geef een leeftijd");
        int b = Convert.ToInt32(Console.ReadLine());

        int einde = Sum(a, b);
        Console.WriteLine(einde);
    }
    static int Sum(int x, int y)
    {
        int result = x + y;
        return result;

What is move semantics?

In easy (practical) terms:

Copying an object means copying its "static" members and calling the new operator for its dynamic objects. Right?

class A
{
   int i, *p;

public:
   A(const A& a) : i(a.i), p(new int(*a.p)) {}
   ~A() { delete p; }
};

However, to move an object (I repeat, in a practical point of view) implies only to copy the pointers of dynamic objects, and not to create new ones.

But, is that not dangerous? Of course, you could destruct a dynamic object twice (segmentation fault). So, to avoid that, you should "invalidate" the source pointers to avoid destructing them twice:

class A
{
   int i, *p;

public:
   // Movement of an object inside a copy constructor.
   A(const A& a) : i(a.i), p(a.p)
   {
     a.p = nullptr; // pointer invalidated.
   }

   ~A() { delete p; }
   // Deleting NULL, 0 or nullptr (address 0x0) is safe. 
};

Ok, but if I move an object, the source object becomes useless, no? Of course, but in certain situations that's very useful. The most evident one is when I call a function with an anonymous object (temporal, rvalue object, ..., you can call it with different names):

void heavyFunction(HeavyType());

In that situation, an anonymous object is created, next copied to the function parameter, and afterwards deleted. So, here it is better to move the object, because you don't need the anonymous object and you can save time and memory.

This leads to the concept of an "rvalue" reference. They exist in C++11 only to detect if the received object is anonymous or not. I think you do already know that an "lvalue" is an assignable entity (the left part of the = operator), so you need a named reference to an object to be capable to act as an lvalue. A rvalue is exactly the opposite, an object with no named references. Because of that, anonymous object and rvalue are synonyms. So:

class A
{
   int i, *p;

public:
   // Copy
   A(const A& a) : i(a.i), p(new int(*a.p)) {}

   // Movement (&& means "rvalue reference to")
   A(A&& a) : i(a.i), p(a.p)
   {
      a.p = nullptr;
   }

   ~A() { delete p; }
};

In this case, when an object of type A should be "copied", the compiler creates a lvalue reference or a rvalue reference according to if the passed object is named or not. When not, your move-constructor is called and you know the object is temporal and you can move its dynamic objects instead of copying them, saving space and memory.

It is important to remember that "static" objects are always copied. There's no ways to "move" a static object (object in stack and not on heap). So, the distinction "move"/ "copy" when an object has no dynamic members (directly or indirectly) is irrelevant.

If your object is complex and the destructor has other secondary effects, like calling to a library's function, calling to other global functions or whatever it is, perhaps is better to signal a movement with a flag:

class Heavy
{
   bool b_moved;
   // staff

public:
   A(const A& a) { /* definition */ }
   A(A&& a) : // initialization list
   {
      a.b_moved = true;
   }

   ~A() { if (!b_moved) /* destruct object */ }
};

So, your code is shorter (you don't need to do a nullptr assignment for each dynamic member) and more general.

Other typical question: what is the difference between A&& and const A&&? Of course, in the first case, you can modify the object and in the second not, but, practical meaning? In the second case, you can't modify it, so you have no ways to invalidate the object (except with a mutable flag or something like that), and there is no practical difference to a copy constructor.

And what is perfect forwarding? It is important to know that a "rvalue reference" is a reference to a named object in the "caller's scope". But in the actual scope, a rvalue reference is a name to an object, so, it acts as a named object. If you pass an rvalue reference to another function, you are passing a named object, so, the object isn't received like a temporal object.

void some_function(A&& a)
{
   other_function(a);
}

The object a would be copied to the actual parameter of other_function. If you want the object a continues being treated as a temporary object, you should use the std::move function:

other_function(std::move(a));

With this line, std::move will cast a to an rvalue and other_function will receive the object as a unnamed object. Of course, if other_function has not specific overloading to work with unnamed objects, this distinction is not important.

Is that perfect forwarding? Not, but we are very close. Perfect forwarding is only useful to work with templates, with the purpose to say: if I need to pass an object to another function, I need that if I receive a named object, the object is passed as a named object, and when not, I want to pass it like a unnamed object:

template<typename T>
void some_function(T&& a)
{
   other_function(std::forward<T>(a));
}

That's the signature of a prototypical function that uses perfect forwarding, implemented in C++11 by means of std::forward. This function exploits some rules of template instantiation:

 `A& && == A&`
 `A&& && == A&&`

So, if T is a lvalue reference to A (T = A&), a also (A& && => A&). If T is a rvalue reference to A, a also (A&& && => A&&). In both cases, a is a named object in the actual scope, but T contains the information of its "reference type" from the caller scope's point of view. This information (T) is passed as template parameter to forward and 'a' is moved or not according to the type of T.

How do I check out a remote Git branch?

With One Remote

Jakub's answer actually improves on this. With Git versions = 1.6.6, with only one remote, you can do:

git fetch
git checkout test

As user masukomi points out in a comment, git checkout test will NOT work in modern git if you have multiple remotes. In this case use

git checkout -b test <name of remote>/test

or the shorthand

git checkout -t <name of remote>/test

With >1 Remotes

Before you can start working locally on a remote branch, you need to fetch it as called out in answers below.

To fetch a branch, you simply need to:

git fetch origin

This will fetch all of the remote branches for you. You can see the branches available for checkout with:

git branch -v -a

With the remote branches in hand, you now need to check out the branch you are interested in, giving you a local working copy:

git checkout -b test origin/test

How to get build time stamp from Jenkins build variables?

If you want add a timestamp to every request from browser to jenkins server. You can refer to the jenkins crumb issuer mechanism, and you can hack the /scripts/hudson-behavior.js add modify here. so it will transform a timestamp to server.

    /**
     * Puts a hidden input field to the form so that the form submission will have the crumb value
     */
    appendToForm : function(form) {
        // add here. ..... you code
        if(this.fieldName==null)    return; // noop
        var div = document.createElement("div");
        div.innerHTML = "<input type=hidden name='"+this.fieldName+"' value='"+this.value+"'>";
        form.appendChild(div);
    }

Simple int to char[] conversion

If you want to convert an int which is in the range 0-9 to a char, you may usually write something like this:

int x;
char c = '0' + x;

Now, if you want a character string, just add a terminating '\0' char:

char s[] = {'0' + x, '\0'};

Note that:

  1. You must be sure that the int is in the 0-9 range, otherwise it will fail,
  2. It works only if character codes for digits are consecutive. This is true in the vast majority of systems, that are ASCII-based, but this is not guaranteed to be true in all cases.

rand() between 0 and 1

rand() / double(RAND_MAX) generates a floating-point random number between 0 (inclusive) and 1 (inclusive), but it's not a good way for the following reasons (because RAND_MAX is usually 32767):

  1. The number of different random numbers that can be generated is too small: 32768. If you need more different random numbers, you need a different way (a code example is given below)
  2. The generated numbers are too coarse-grained: you can get 1/32768, 2/32768, 3/32768, but never anything in between.
  3. Limited states of random number generator engine: after generating RAND_MAX random numbers, implementations usually start to repeat the same sequence of random numbers.

Due to the above limitations of rand(), a better choice for generation of random numbers between 0 (inclusive) and 1 (exclusive) would be the following snippet (similar to the example at http://en.cppreference.com/w/cpp/numeric/random/uniform_real_distribution ):

#include <iostream>
#include <random>
#include <chrono>

int main()
{
    std::mt19937_64 rng;
    // initialize the random number generator with time-dependent seed
    uint64_t timeSeed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
    std::seed_seq ss{uint32_t(timeSeed & 0xffffffff), uint32_t(timeSeed>>32)};
    rng.seed(ss);
    // initialize a uniform distribution between 0 and 1
    std::uniform_real_distribution<double> unif(0, 1);
    // ready to generate random numbers
    const int nSimulations = 10;
    for (int i = 0; i < nSimulations; i++)
    {
        double currentRandomNumber = unif(rng);
        std::cout << currentRandomNumber << std::endl;
    }
    return 0;
}

This is easy to modify to generate random numbers between 1 (inclusive) and 2 (exclusive) by replacing unif(0, 1) with unif(1, 2).

How to use a global array in C#?

Your class shoud look something like this:

class Something {     int[] array; //global array, replace type of course     void function1() {        array = new int[10]; //let say you declare it here that will be 10 integers in size     }     void function2() {        array[0] = 12; //assing value at index 0 to 12.     } } 

That way you array will be accessible in both functions. However, you must be careful with global stuff, as you can quickly overwrite something.

Get list of all tables in Oracle?

Indeed, it is possible to have the list of tables via SQL queries.it is possible to do that also via tools that allow the generation of data dictionaries, such as ERWIN, Toad Data Modeler or ERBuilder. With these tools, in addition to table names, you will have fields, their types, objects like(triggers, sequences, domain, views...)

Below steps to follow to generate your tables definition:

  1. You have to reverse engineer your database
    • In Toad data modeler: Menu -> File -> reverse engineer -> reverse engineering wizard
    • In ERBuilder data modeler: Menu -> File -> reverse engineer

Your database will be displayed in the software as an Entity Relationship diagram.

  1. Generate your data dictionary that will contain your Tables definition
    • In Toad data modeler: Menu -> Model -> Generate report -> Run
    • In ERBuilder data modeler: Menu -> Tool -> generate model documentation

How to convert Nonetype to int or string?

A common "Pythonic" way to handle this kind of situation is known as EAFP for "It's easier to ask forgiveness than permission". Which usually means writing code that assumes everything is fine, but then wrapping it with a try...except block to handle things—just in case—it's not.

Here's that coding style applied to your problem:

try:
    my_value = int(my_value)
except TypeError:
    my_value = 0  # or whatever you want to do

answer = my_value / divisor

Or perhaps the even simpler and slightly faster:

try:
    answer = int(my_value) / divisor
except TypeError:
    answer = 0

The inverse and more traditional approach is known as LBYL which stands for "Look before you leap" is what @Soviut and some of the others have suggested. For additional coverage of this topic see my answer and associated comments to the question Determine whether a key is present in a dictionary elsewhere on this site.

One potential problem with EAFP is that it can hide the fact that something is wrong with some other part of your code or third-party module you're using, especially when the exceptions frequently occur (and therefore aren't really "exceptional" cases at all).

TypeError: 'tuple' object does not support item assignment when swapping values

Evaluating "1,2,3" results in (1, 2, 3), a tuple. As you've discovered, tuples are immutable. Convert to a list before processing.

How to clear basic authentication details in chrome

Shortest way: Click lock icon in address bar. Then click Site settings, then click Reset permissions

enter image description here enter image description here

How to iterate over a std::map full of strings in C++

Another worthy optimization is the c_str ( ) member of the STL string classes, which returns an immutable null terminated string that can be passed around as a LPCTSTR, e. g., to a custom function that expects a LPCTSTR. Although I haven't traced through the destructor to confirm it, I suspect that the string class looks after the memory in which it creates the copy.

Android Studio Gradle Already disposed Module

If gradle clean and/or Build -> Clean Project didn't help try to re-open the project:

  • Close the project
  • Click "Open an existing Android Studio project" on the "Welcome to Android Studio" screen enter image description here
  • Select gradle file to open

Warning Be aware it's a destructive operation - you're going to loose the project bookmarks, breakpoints and shelves

How to store date/time and timestamps in UTC time zone with JPA and Hibernate

Please take a look at my project on Sourceforge which has user types for standard SQL Date and Time types as well as JSR 310 and Joda Time. All of the types try to address the offsetting issue. See http://sourceforge.net/projects/usertype/

EDIT: In response to Derek Mahar's question attached to this comment:

"Chris, do your user types work with Hibernate 3 or greater? – Derek Mahar Nov 7 '10 at 12:30"

Yes these types support Hibernate 3.x versions including Hibernate 3.6.

python: SyntaxError: EOL while scanning string literal

You can try this:

s = r'long\annoying\path'

What is the maximum length of a Push Notification alert text?

see my test here

I could send up to 33 Chinese characters and 13 bytes of custom values.

Get the filePath from Filename using Java

Correct solution with "File" class to get the directory - the "path" of the file:

String path = new File("C:\\Temp\\your directory\\yourfile.txt").getParent();

which will return:

path = "C:\\Temp\\your directory"

How do I get a python program to do nothing?

You can use continue

if condition:
    continue
else:
    #do something

How to set ANDROID_HOME path in ubuntu?

Assuming you have the sdk extracted at ~/Android/Sdk,

export ANDROID_HOME=$HOME/Android/Sdk
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/platform-tools
  1. Add the above lines to the file ~/.bashrc (located at home/username/.bashrc) to make it permanent for the current user. Run source ~/.bashrc to apply the changes or restart your terminal.

    (or)

  2. Run the above lines on a terminal window to make it available for the session.


To test if you have set it up correctly,

Run the below commands on a terminal window

  1. echo $ANDROID_HOME

    user@host:~$ echo $ANDROID_HOME
    /home/<user>/Android/Sdk
    
  2. which android

    user@host:~$ which android
    /home/<user>/Android/Sdk/tools/android
    
  3. Run android on a terminal window, If it opens up Android SDK Manager, you are good to go.

How to install Android SDK on Ubuntu?

Option 1:

sudo apt update && sudo apt install android-sdk

The location of Android SDK on Linux can be any of the following:

  • /home/AccountName/Android/Sdk

  • /usr/lib/android-sdk

  • /Library/Android/sdk/

  • /Users/[USER]/Library/Android/sdk

Option 2:

  • Download the Android Studio.

  • Extract downloaded .zip file.

    The extracted folder name will read somewhat like android-studio

To keep navigation easy, move this folder to Home directory.

  • After moving, copy the moved folder by right clicking it. This action will place folder's location to clipboard.

  • Use Ctrl Alt T to open a terminal

  • Go to this folder's directory using cd /home/(USER NAME)/android-studio/bin/

  • Type this command to make studio.sh executable: chmod +x studio.sh

  • Type ./studio.sh

A pop up will be shown asking for installation settings. In my particular case, it is a fresh install so I'll go with selecting I do not have a previous version of Studio or I do not want to import my settings.

If you choose to import settings anyway, you may need to close any old project which is opened in order to get a working Android SDK.

./studio.sh popup

From now onwards, setup wizard will guide you.

Android studio setup wizard

Android Studio can work with both Open JDK and Oracle's JDK (recommended). Incase, Open JDK is installed the wizard will recommend installing Oracle Java JDK because some UI and performance issues are reported while using OpenJDK.

The downside with Oracle's JDK is that it won't update with the rest of your system like OpenJDK will.

The wizard may also prompt about the input problems with IDEA .

Select install type

Select Android studio install type

Verify installation settings

Verify Android studio installation settings

An emulator can also be configured as needed.

Android studio emulator configuration prompt

The wizard will start downloading the necessary SDK tools

The wizard may also show an error about Linux 32 Bit Libraries, which can be solved by using the below command:

sudo apt-get install libc6:i386 libncurses5:i386 libstdc++6:i386 lib32z1

After this, all the required components will be downloaded and installed automatically.

After everything is upto the mark, just click finish

Completed installation of Android studio

To make a Desktop icon, go to 'Configure' and then click 'Create Desktop Entry'

Creating Android studio desktop icon

Creating Android studio desktop icon for one or multiple users

source

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

I use Laravel 5.7 I had the same problem and it was because the csrf token wasn't in the form, so adding

@csrf

fixed the problem

Calculating frames per second in a game

You could keep a counter, increment it after each frame is rendered, then reset the counter when you are on a new second (storing the previous value as the last second's # of frames rendered)

Calculate average in java

for 1. the number of integers read in, you can just use length property of array like :

int count = args.length

which gives you no of elements in an array. And 2. to calculate average value : you are doing in correct way.

Where does MAMP keep its php.ini?

I don't know if you ever found an answer to this but I DIDN'T need MAMP PRO to do this. Simply goto the correct path by following what others have said. It's something like...

MAMP-> bin-> php-> php(your php version)-> conf-> php.ini

The key here is where you're editing the file. I was making the mistake of editing the commented part of the ini file. You actually have to scroll down to LINE #472 where it says "display_errors = Off and change it to On. Hope this helps any

Get selected value from combo box in C# WPF

Ensure you have set the name for your ComboBox in your XAML file:

<ComboBox Height="23" Name="comboBox" />

In your code you can access selected item using SelectedItem property:

MessageBox.Show(comboBox.SelectedItem.ToString());

javascript pushing element at the beginning of an array

For an uglier version of unshift use splice:

TheArray.splice(0, 0, TheNewObject);

Extract code country from phone number [libphonenumber]

Okay, so I've joined the google group of libphonenumber ( https://groups.google.com/forum/?hl=en&fromgroups#!forum/libphonenumber-discuss ) and I've asked a question.

I don't need to set the country in parameter if my phone number begins with "+". Here is an example :

PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();
try {
    // phone must begin with '+'
    PhoneNumber numberProto = phoneUtil.parse(phone, "");
    int countryCode = numberProto.getCountryCode();
} catch (NumberParseException e) {
    System.err.println("NumberParseException was thrown: " + e.toString());
}

Ansible: Store command's stdout in new variable?

You have to store the content as a fact:

- set_fact:
    string_to_echo: "{{ command_output.stdout }}"

How do I stop Notepad++ from showing autocomplete for all words in the file

The answer is to DISABLE "Enable auto-completion on each input". Tested and works perfectly.

Remove characters after specific character in string, then remove substring?

For string manipulation, if you just want to kill everything after the ?, you can do this

string input = "http://www.somesite.com/somepage.aspx?whatever";
int index = input.IndexOf("?");
if (index > 0)
   input = input.Substring(0, index);

Edit: If everything after the last slash, do something like

string input = "http://www.somesite.com/somepage.aspx?whatever";
int index = input.LastIndexOf("/");
if (index > 0)
    input = input.Substring(0, index); // or index + 1 to keep slash

Alternately, since you're working with a URL, you can do something with it like this code

System.Uri uri = new Uri("http://www.somesite.com/what/test.aspx?hello=1");
string fixedUri = uri.AbsoluteUri.Replace(uri.Query, string.Empty);

What does the "assert" keyword do?

If the condition isn't satisfied, an AssertionError will be thrown.

Assertions have to be enabled, though; otherwise the assert expression does nothing. See:

http://java.sun.com/j2se/1.5.0/docs/guide/language/assert.html#enable-disable

Angular2 *ngFor in select list, set active based on string from object

Check it out in this demo fiddle, go ahead and change the dropdown or default values in the code.

Setting the passenger.Title with a value that equals to a title.Value should work.

View:

<select [(ngModel)]="passenger.Title">
    <option *ngFor="let title of titleArray" [value]="title.Value">
      {{title.Text}}
    </option>
</select>

TypeScript used:

class Passenger {
  constructor(public Title: string) { };
}
class ValueAndText {
  constructor(public Value: string, public Text: string) { }
}

...
export class AppComponent {
    passenger: Passenger = new Passenger("Lord");

    titleArray: ValueAndText[] = [new ValueAndText("Mister", "Mister-Text"),
                                  new ValueAndText("Lord", "Lord-Text")];

}

How to run PyCharm in Ubuntu - "Run in Terminal" or "Run"?

As mentioned in the above answer, by updating the bashrc file you can run the pycharm.sh from anywhere on the linux terminal.

But if you love the icon and wants the Desktop shortcuts for the Pycharm on Ubuntu OS then follow the Below steps,

 Quick way to create Pycharm launcher. 
     1. Start Pycharm using the pycharm.sh cmd from anywhere on the terminal or start the pycharm.sh located under bin folder of the pycharm artifact.
     2. Once the Pycharm application loads, navigate to tools menu and select “Create Desktop Entry..”
     3. Check the box if you want the launcher for all users.
     4. If you Check the box i.e “Create entry for all users”, you will be asked for your password.
     5. A message should appear informing you that it was successful.
     6. Now Restart Pycharm application and you will find Pycharm in Unity dash and Application launcher.."

How to use comparison and ' if not' in python?

In this particular case the clearest solution is the S.Lott answer

But in some complex logical conditions I would prefer use some boolean algebra to get a clear solution.

Using De Morgan's law ¬(A^B) = ¬Av¬B

not (u0 <= u and u < u0+step)
(not u0 <= u) or (not u < u0+step)
u0 > u or u >= u0+step

then

if u0 > u or u >= u0+step:
    pass

... in this case the «clear» solution is not more clear :P

Javascript change Div style

A simple switch statement should do the trick:

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

Rails: select unique values from a column

If I am going right to way then :

Current query

Model.select(:rating)

is returning array of object and you have written query

Model.select(:rating).uniq

uniq is applied on array of object and each object have unique id. uniq is performing its job correctly because each object in array is uniq.

There are many way to select distinct rating :

Model.select('distinct rating').map(&:rating)

or

Model.select('distinct rating').collect(&:rating)

or

Model.select(:rating).map(&:rating).uniq

or

Model.select(:name).collect(&:rating).uniq

One more thing, first and second query : find distinct data by SQL query.

These queries will considered "london" and "london   " same means it will neglect to space, that's why it will select 'london' one time in your query result.

Third and forth query:

find data by SQL query and for distinct data applied ruby uniq mehtod. these queries will considered "london" and "london " different, that's why it will select 'london' and 'london ' both in your query result.

please prefer to attached image for more understanding and have a look on "Toured / Awaiting RFP".

enter image description here

List of Timezone IDs for use with FindTimeZoneById() in C#?

List of time zone identifiers, included by default in Windows XP and Vista: Finding the Time Zones Defined on a Local System

How to align checkboxes and their labels consistently cross-browsers

input {
    margin: 0;
}

actually does the trick

How to use PHP to connect to sql server

Use localhost instead of your IP address.

e.g,

$myServer = "localhost";

And also double check your mysql username and password.

Python Unicode Encode Error

Don't hardcode the character encoding of your environment inside your script; print Unicode text directly instead:

assert isinstance(text, unicode) # or str on Python 3
print(text)

If your output is redirected to a file (or a pipe); you could use PYTHONIOENCODING envvar, to specify the character encoding:

$ PYTHONIOENCODING=utf-8 python your_script.py >output.utf8

Otherwise, python your_script.py should work as is -- your locale settings are used to encode the text (on POSIX check: LC_ALL, LC_CTYPE, LANG envvars -- set LANG to a utf-8 locale if necessary).

To print Unicode on Windows, see this answer that shows how to print Unicode to Windows console, to a file, or using IDLE.

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

How to create an Observable from static data similar to http one in Angular?

This is how you can create a simple observable for static data.

let observable = Observable.create(observer => {
  setTimeout(() => {
    let users = [
      {username:"balwant.padwal",city:"pune"},
      {username:"test",city:"mumbai"}]

    observer.next(users); // This method same as resolve() method from Angular 1
    console.log("am done");
    observer.complete();//to show we are done with our processing
    // observer.error(new Error("error message"));
  }, 2000);

})

to subscribe to it is very easy

observable.subscribe((data)=>{
  console.log(data); // users array display
});

I hope this answer is helpful. We can use HTTP call instead static data.

Is ini_set('max_execution_time', 0) a bad idea?

Reason is to have some value other than zero. General practice to have it short globally and long for long working scripts like parsers, crawlers, dumpers, exporting & importing scripts etc.

  1. You can halt server, corrupt work of other people by memory consuming script without even knowing it.
  2. You will not be seeing mistakes where something, let's say, infinite loop happened, and it will be harder to diagnose.
  3. Such site may be easily DoSed by single user, when requesting pages with long execution time

Get a Div Value in JQuery

$('#myDiv').text()

Although you'd be better off doing something like:

_x000D_
_x000D_
var txt = $('#myDiv p').text();_x000D_
alert(txt);
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="myDiv"><p>Some Text</p></div>
_x000D_
_x000D_
_x000D_

Make sure you're linking to your jQuery file too :)

What is the difference between CMD and ENTRYPOINT in a Dockerfile?

According to docker docs,

Both CMD and ENTRYPOINT instructions define what command gets executed when running a container. There are few rules that describe their co-operation.

  1. Dockerfile should specify at least one of CMD or ENTRYPOINT commands.
  2. ENTRYPOINT should be defined when using the container as an executable.
  3. CMD should be used as a way of defining default arguments for an ENTRYPOINT command or for executing an ad-hoc command in a container.
  4. CMD will be overridden when running the container with alternative arguments.

The tables below shows what command is executed for different ENTRYPOINT / CMD combinations:

-- No ENTRYPOINT

+----------------------------------------------------------+
¦ No CMD                     ¦ error, not allowed          ¦
¦----------------------------+-----------------------------¦
¦ CMD ["exec_cmd", "p1_cmd"] ¦ exec_cmd p1_cmd             ¦
¦----------------------------+-----------------------------¦
¦ CMD ["p1_cmd", "p2_cmd"]   ¦ p1_cmd p2_cmd               ¦
¦----------------------------+-----------------------------¦
¦ CMD exec_cmd p1_cmd        ¦ /bin/sh -c exec_cmd p1_cmd  ¦
+----------------------------------------------------------+

-- ENTRYPOINT exec_entry p1_entry

+---------------------------------------------------------------+
¦ No CMD                     ¦ /bin/sh -c exec_entry p1_entry   ¦
¦----------------------------+----------------------------------¦
¦ CMD ["exec_cmd", "p1_cmd"] ¦ /bin/sh -c exec_entry p1_entry   ¦
¦----------------------------+----------------------------------¦
¦ CMD ["p1_cmd", "p2_cmd"]   ¦ /bin/sh -c exec_entry p1_entry   ¦
¦----------------------------+----------------------------------¦
¦ CMD exec_cmd p1_cmd        ¦ /bin/sh -c exec_entry p1_entry   ¦
+---------------------------------------------------------------+

-- ENTRYPOINT ["exec_entry", "p1_entry"]

+------------------------------------------------------------------------------+
¦ No CMD                     ¦ exec_entry p1_entry                             ¦
¦----------------------------+-------------------------------------------------¦
¦ CMD ["exec_cmd", "p1_cmd"] ¦ exec_entry p1_entry exec_cmd p1_cmd             ¦
¦----------------------------+-------------------------------------------------¦
¦ CMD ["p1_cmd", "p2_cmd"]   ¦ exec_entry p1_entry p1_cmd p2_cmd               ¦
¦----------------------------+-------------------------------------------------¦
¦ CMD exec_cmd p1_cmd        ¦ exec_entry p1_entry /bin/sh -c exec_cmd p1_cmd  ¦
+------------------------------------------------------------------------------+

How do I restrict my EditText input to numerical (possibly decimal and signed) input?

Hi All I also had this problem. I use C# with Xamarin

Just a slight note that I hope someone else as well.

I have tried multiple of the methods mentioned here.

edittext1.SetRawInputType(Android.Text.InputTypes.ClassNumber | Android.Text.InputTypes.NumberFlagDecimal);

was the closest but still did not work. As Ralf mentioned, you could use

edit.setInputType(InputType.TYPE_CLASS_NUMBER | InputType.TYPE_NUMBER_FLAG_DECIMAL | InputType.TYPE_NUMBER_FLAG_SIGNED);

However in my C# I did not have this. instead you do it as follow:

edittext1.InputType = Android.Text.InputTypes.ClassNumber | Android.Text.InputTypes.NumberFlagDecimal;

Please note that the ORDER of these is important. If you put Decimal first, it will still allow you to type any Characters, where If Numer is first it is only numeric, but allows a decimal seperator!

Is Visual Studio Community a 30 day trial?

IMPORTANT DISCLAIMER: Information provided below is for educational purposes only! Extending a trial period of Visual Studio Community 2017 might be ILLEGAL!

So let's get started.

Registry key of interest: HKEY_CLASSES_ROOT\Licenses\5C505A59-E312-4B89-9508-E162F8150517\08878. I assume the 08878 subkey may differ from installation to installation (why not, isn't?). I have tested only on my own one. So check other subkeys if you can not match proper values described below. Binary value stored in that key is encrypted with CryptProtectData. So decrypt it first with CryptUnprotectData. Bytes of interest (little-endian):

  • [-16] and [-15] is a year of expiration;
  • [-14] and [-13] is a month of expiration;
  • [-12] and [-11] is a day of expiration.

Increasing these values (preferable the year :) ) WILL extend your trial period and get rid of a blocking screen! I know nothing of such a tool that allows to edit encrypted registry values, so my small program in C++ and Windows API looks like:

RegGetValue
CryptUnprotectData
Data.pbData[Data.cbData-16]++;
CryptProtectData
RegSetValue

Actual language doesn't matter if you have access to registry and crypto functions in your language. I'm just fluent in C++. Sorry, I do not publish a ready-to-use code for ethical reason.

submitting a GET form with query string params and hidden params disappear

I usually write something like this:

foreach($_GET as $key=>$content){
        echo "<input type='hidden' name='$key' value='$content'/>";
}

This is working, but don't forget to sanitize your inputs against XSS attacks!

How to 'bulk update' with Django?

Update:

Django 2.2 version now has a bulk_update.

Old answer:

Refer to the following django documentation section

Updating multiple objects at once

In short you should be able to use:

ModelClass.objects.filter(name='bar').update(name="foo")

You can also use F objects to do things like incrementing rows:

from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)

See the documentation.

However, note that:

  • This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
  • No django signals will be emitted.
  • You can't perform an .update() on a sliced QuerySet, it must be on an original QuerySet so you'll need to lean on the .filter() and .exclude() methods.

What does elementFormDefault do in XSD?

elementFormDefault="qualified" is used to control the usage of namespaces in XML instance documents (.xml file), rather than namespaces in the schema document itself (.xsd file).

By specifying elementFormDefault="qualified" we enforce namespace declaration to be used in documents validated with this schema.

It is common practice to specify this value to declare that the elements should be qualified rather than unqualified. However, since attributeFormDefault="unqualified" is the default value, it doesn't need to be specified in the schema document, if one does not want to qualify the namespaces.

Elasticsearch query to return all records

The official documentation provides the answer to this question! you can find it here.

{
  "query": { "match_all": {} },
  "size": 1
}

You simply replace size (1) with the number of results you want to see!

pip cannot install anything

On Virtualenv try editing the pip file, like so:

vi <your_virtualenv_folder>/bin/pip

look at the first line and check if it corresponds to the project folder, if not just change it.

#!/<your_path>/<project_folder>/<your_virtualenv_folder>/bin/python

Moving Git repository content to another repository preserving history

Perfectly described here https://www.smashingmagazine.com/2014/05/moving-git-repository-new-server/

First, we have to fetch all of the remote branches and tags from the existing repository to our local index:

git fetch origin

We can check for any missing branches that we need to create a local copy of:

git branch -a

Let’s use the SSH-cloned URL of our new repository to create a new remote in our existing local repository:

git remote add new-origin [email protected]:manakor/manascope.git

Now we are ready to push all local branches and tags to the new remote named new-origin:

git push --all new-origin 
git push --tags new-origin

Let’s make new-origin the default remote:

git remote rm origin

Rename new-origin to just origin, so that it becomes the default remote:

git remote rename new-origin origin

How can I disable editing cells in a WPF Datagrid?

The DataGrid has an XAML property IsReadOnly that you can set to true:

<my:DataGrid
    IsReadOnly="True"
/>

Total Number of Row Resultset getRow Method

One better way would be to use SELECT COUNT statement of SQL.

Just when you need the count of number of rows returned, execute another query returning the exact number of result of that query.

 try
{
   Conn=ConnectionODBC.getConnection();
   Statement stmt = Conn.createStatement();        
    String sqlStmt = sql;        
    String sqlrow = SELECT COUNT(*) from (sql) rowquery;
    String total = stmt.executeQuery(sqlrow);
    int rowcount = total.getInt(1);
    }

fatal error LNK1104: cannot open file 'kernel32.lib'

In Visual Studio 2017, I went to Project Properties -> Configuration Properties -> General, Selected All Platforms (1), then chose the dropdown (2) under Windows SDK Version and updated from 10.0.14393.0 to one that was installed (3). For me, that was 10.0.15063.0.

enter image description here

Additional details: This corrected the error in my case because Windows SDK Version helps VS select the correct paths. VC++ Directories -> Library Directories -> Edit -> Macros -> shows that macro $(WindowsSDK_LibraryPath_x86) has a path with the version number selected above.

ios Upload Image and Text using HTTP POST

I can show you an example of uploading a .txt file to a server with NSMutableURLRequest and NSURLSessionUploadTask with help of a php script.

-(void)uploadFileToServer : (NSString *) filePath
{
NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://YourURL.com/YourphpScript.php"]];
[request setHTTPMethod:@"POST"]; 
[request addValue:@"File Name" forHTTPHeaderField:@"FileName"];
NSURLSessionConfiguration *defaultConfigObject = [NSURLSessionConfiguration defaultSessionConfiguration];
NSURLSession *defaultSession = [NSURLSession sessionWithConfiguration:defaultConfigObject];

NSURLSessionUploadTask* uploadTask = [defaultSession uploadTaskWithRequest:request fromFile:[NSURL URLWithString:filePath] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
                                      {
                                          NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *) response;
                                          if (error || [httpResponse statusCode]!=202)
                                          {

                                              //Error
                                          }
                                          else
                                          {
                                             //Success
                                          }
                                          [defaultSession invalidateAndCancel];
                                      }];
[uploadTask resume];
}

php Script

<?php 
$request_body = @file_get_contents('php://input');
foreach (getallheaders() as $name => $value) 
{
    if ($FileName=="FileName") 
    {
        $header=$value;
        break;
    }
}   
$uploadedDir = "directory/";
@mkdir($uploadedDir);
file_put_contents($uploadedDir."/".$FileName.".txt",
$request_body.PHP_EOL, FILE_APPEND);
header('X-PHP-Response-Code: 202', true, 202);  
?>       

Can I embed a custom font in an iPhone application?

There is a simple way to use custom fonts in iOS 4.

  1. Add your font file (for example, Chalkduster.ttf) to Resources folder of the project in XCode.
  2. Open info.plist and add a new key called UIAppFonts. The type of this key should be array.
  3. Add your custom font name to this array including extension (Chalkduster.ttf).
  4. Now you can use [UIFont fontWithName:@"Chalkduster" size:16] in your application.

Unfortunately, IB doesn't allow to initialize labels with custom fonts. See this question to solve this problem. My favorite solution is to use custom UILabel subclass:

@implementation CustomFontLabel

- (id)initWithCoder:(NSCoder *)decoder
{
    if (self = [super initWithCoder: decoder])
    {
        [self setFont: [UIFont fontWithName: @"Chalkduster" size: self.font.pointSize]];
    }
    return self;
}

@end

C++ int to byte array

You don't need a whole function for this; a simple cast will suffice:

int x;
static_cast<char*>(static_cast<void*>(&x));

Any object in C++ can be reinterpreted as an array of bytes. If you want to actually make a copy of the bytes into a separate array, you can use std::copy:

int x;
char bytes[sizeof x];
std::copy(static_cast<const char*>(static_cast<const void*>(&x)),
          static_cast<const char*>(static_cast<const void*>(&x)) + sizeof x,
          bytes);

Neither of these methods takes byte ordering into account, but since you can reinterpret the int as an array of bytes, it is trivial to perform any necessary modifications yourself.

Real time data graphing on a line chart with html5

This thread is perhaps very very old now. But want to share these results for someone who see this thread. Ran a comparison betn. Flotr2, ChartJS, highcharts asynchronously. Flotr2 seems to be the quickest. Tested this by passing a new data point every 50ms upto 1000 data points totally. Flotr2 was the quickest for me though it appears to be redrawing charts regularly.

http://jsperf.com/async-charts-test/2

Characters allowed in GET parameter

The question asks which characters are allowed in GET parameters without encoding or escaping them.

According to RFC3986 (general URL syntax) and RFC7230, section 2.7.1 (HTTP/S URL syntax) the only characters you need to percent-encode are those outside of the query set, see the definition below.

However, there are additional specifications like HTML5, Web forms, and the obsolete Indexed search, W3C recommendation. Those documents add a special meaning to some characters notably, to symbols like = & + ;.

Other answers here suggest that most of the reserved characters should be encoded, including "/" "?". That's not correct. In fact, RFC3986, section 3.4 advises against percent-encoding "/" "?" characters.

it is sometimes better for usability to avoid percent- encoding those characters.

RFC3986 defines query component as:

query       = *( pchar / "/" / "?" )
pchar       = unreserved / pct-encoded / sub-delims / ":" / "@"
pct-encoded = "%" HEXDIG HEXDIG
sub-delims  = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~" 

A percent-encoding mechanism is used to represent a data octet in a component when that octet's corresponding character is outside the allowed set or is being used as a delimiter of, or within, the component.

The conclusion is that XYZ part should encode:

special: # % = & ;
Space
sub-delims
out of query set: [ ]
non ASCII encodable characters

Unless special symbols = & ; are key=value separators.

Encoding other characters is allowed but not necessary.

MySQL integer field is returned as string in PHP

This happens when PDO::ATTR_EMULATE_PREPARES is set to true on the connection.

Careful though, setting it to false disallows the use of parameters more than once. I believe it also affects the quality of the error messages coming back.

ActionController::UnknownFormat

Well I fond this post because I got a similar error. So I added the top line like in your controller respond_to :html, :json

then I got a different error(see below)

The controller-level respond_to' feature has been extracted to theresponders` gem. Add it to your Gemfile to continue using this feature: gem 'responders', '~> 2.0' Consult the Rails upgrade guide for details. But that had nothing to do with it.

wkhtmltopdf: cannot connect to X server

Update to latest wkhtmltopdf version from SourceForge (0.12 as of this writing). It does not need an X Server to run.

Example for Ubuntu 14.04:

$ cd /tmp/                                                                                                                                                                                                       
$ wget -q http://downloads.sourceforge.net/project/wkhtmltopdf/0.12.2.1/wkhtmltox-0.12.2.1_linux-trusty-amd64.deb
$ dpkg -x wkhtmltox-0.12.2.1_linux-trusty-amd64.deb foo

$ echo '<p>hi</p>' | ./foo/usr/local/bin/wkhtmltopdf - /tmp/hi.pdf
Loading pages (1/6)
Counting pages (2/6)                                               
Resolving links (4/6)                                                       
Loading headers and footers (5/6)                                           
Printing pages (6/6)
Done                                                                      

$ head -n3 /tmp/hi.pdf 
%PDF-1.4
1 0 obj
<<

Only allow Numbers in input Tag without Javascript

Of course, you can't fully rely on the client-side (javascript) validation, but that's not a reason to avoid it completely. With or without it, you have to do the server-side validation anyway (since the client can disable javascript). And that's just what you're left with, due to your non-javascript solution constraint.

So, after a submit, if the field value doesn't pass the server-side validation, the client should end up on the very same page, with additional error message specifying the requested value format. You also should provide the value format information beforehands, e.g. as a tool-tip hint (title attribute).

There's most certainly no passive client-side validation mechanism existing in HTML 4 / XHTML.

On the other hand, in HTML 5 you have two options:

  • input of type number:

    <input type="number" min="xxx" max="yyy" title="Format: 3 digits" />
    

    – only validates the range – if user enters a non-number, an empty value is submitted
    – the field visual is enhanced with increment / decrement controls (browser dependent)

  • the pattern attribute:

    <input type="text" pattern="[0-9]{3}" title="Format: 3 digits" />
    <input type="text" pattern="\d{3}" title="Format: 3 digits" />
    

    – this gives you a full contorl over the format (anything you can specify by regular expression)
    – no visual difference / enhancement

But here you still rely on browser capabilities, so do a server-side validation in either case.

Objective-C : BOOL vs bool

The Objective-C type you should use is BOOL. There is nothing like a native boolean datatype, therefore to be sure that the code compiles on all compilers use BOOL. (It's defined in the Apple-Frameworks.

Transparent scrollbar with css

Embed this code in your css.

::-webkit-scrollbar {
    width: 0px;
}

/* Track */

::-webkit-scrollbar-track {
    -webkit-box-shadow: none;
}

/* Handle */

::-webkit-scrollbar-thumb {
    background: white;
    -webkit-box-shadow: none;
}

::-webkit-scrollbar-thumb:window-inactive {
    background: none;
}

How do I add a library project to Android Studio?

To resolve this problem, you just need to add the abs resource path to your project build file, just like below:

sourceSets {
    main {
        res.srcDirs = ['src/main/res','../../ActionBarSherlock/actionbarsherlock/res']
    }
}

So, I again compile without any errors.

How to recover deleted rows from SQL server table?

What is gone is gone. The only protection I know of is regular backup.

How do I get specific properties with Get-AdUser

using select-object for example:

Get-ADUser -Filter * -SearchBase 'OU=Users & Computers, DC=aaaaaaa, DC=com' -Properties DisplayName | select -expand displayname | Export-CSV "ADUsers.csv" 

Switch statement for greater-than/less-than

Updating the accepted answer (can't comment yet). As of 1/12/16 using the demo jsfiddle in chrome, switch-immediate is the fastest solution.

Results: Time resolution: 1.33

   25ms "if-immediate" 150878146 
   29ms "if-indirect" 150878146
   24ms "switch-immediate" 150878146
   128ms "switch-range" 150878146
   45ms "switch-range2" 150878146
   47ms "switch-indirect-array" 150878146
   43ms "array-linear-switch" 150878146
   72ms "array-binary-switch" 150878146

Finished

 1.04 (   25ms) if-immediate
 1.21 (   29ms) if-indirect
 1.00 (   24ms) switch-immediate
 5.33 (  128ms) switch-range
 1.88 (   45ms) switch-range2
 1.96 (   47ms) switch-indirect-array
 1.79 (   43ms) array-linear-switch
 3.00 (   72ms) array-binary-switch

Get Category name from Post ID

function wp_get_post_categories( $post_id = 0, $args = array() )
{
   $post_id = (int) $post_id;
   $defaults = array('fields' => 'ids');
   $args = wp_parse_args( $args, $defaults );
   $cats = wp_get_object_terms($post_id, 'category', $args);

   return $cats;
}

Here is the second argument of function wp_get_post_categories() which you can pass the attributes of receiving data.

$category_detail = get_the_category( '4',array( 'fields' => 'names' ) ); //$post->ID
foreach( $category_detail as $cd )
{
   echo $cd->name;
}

Forward X11 failed: Network error: Connection refused

Do not log in as a root user, try another one with sudo permissions.

How do I insert values into a Map<K, V>?

Try this code

HashMap<String, String> map = new HashMap<String, String>();
map.put("EmpID", EmpID);
map.put("UnChecked", "1");

Ansible: How to delete files and folders inside a directory?

I have written an custom ansible module to cleanup files based on multiple filters like age, timestamp, glob patterns, etc.

It is also compatible with ansible older versions. It can be found here.

Here is an example:

- cleanup_files:
  path_pattern: /tmp/*.log
  state: absent
  excludes:
    - foo*
    - bar*

How to check if an element is off-screen

Well... I've found some issues in every proposed solution here.

  • You should be able to choose if you want entire element to be on screen or just any part of it
  • Proposed solutions fails if element is higher/wider than window and kinda covers browser window.

Here is my solution that include jQuery .fn instance function and expression. I've created more variables inside my function than I could, but for complex logical problem I like to divide it into smaller, clearly named pieces.

I'm using getBoundingClientRect method that returns element position relatively to the viewport so I don't need to care about scroll position

Useage:

$(".some-element").filter(":onscreen").doSomething();
$(".some-element").filter(":entireonscreen").doSomething();
$(".some-element").isOnScreen(); // true / false
$(".some-element").isOnScreen(true); // true / false (partially on screen)
$(".some-element").is(":onscreen"); // true / false (partially on screen)
$(".some-element").is(":entireonscreen"); // true / false 

Source:

$.fn.isOnScreen = function(partial){

    //let's be sure we're checking only one element (in case function is called on set)
    var t = $(this).first();

    //we're using getBoundingClientRect to get position of element relative to viewport
    //so we dont need to care about scroll position
    var box = t[0].getBoundingClientRect();

    //let's save window size
    var win = {
        h : $(window).height(),
        w : $(window).width()
    };

    //now we check against edges of element

    //firstly we check one axis
    //for example we check if left edge of element is between left and right edge of scree (still might be above/below)
    var topEdgeInRange = box.top >= 0 && box.top <= win.h;
    var bottomEdgeInRange = box.bottom >= 0 && box.bottom <= win.h;

    var leftEdgeInRange = box.left >= 0 && box.left <= win.w;
    var rightEdgeInRange = box.right >= 0 && box.right <= win.w;


    //here we check if element is bigger then window and 'covers' the screen in given axis
    var coverScreenHorizontally = box.left <= 0 && box.right >= win.w;
    var coverScreenVertically = box.top <= 0 && box.bottom >= win.h;

    //now we check 2nd axis
    var topEdgeInScreen = topEdgeInRange && ( leftEdgeInRange || rightEdgeInRange || coverScreenHorizontally );
    var bottomEdgeInScreen = bottomEdgeInRange && ( leftEdgeInRange || rightEdgeInRange || coverScreenHorizontally );

    var leftEdgeInScreen = leftEdgeInRange && ( topEdgeInRange || bottomEdgeInRange || coverScreenVertically );
    var rightEdgeInScreen = rightEdgeInRange && ( topEdgeInRange || bottomEdgeInRange || coverScreenVertically );

    //now knowing presence of each edge on screen, we check if element is partially or entirely present on screen
    var isPartiallyOnScreen = topEdgeInScreen || bottomEdgeInScreen || leftEdgeInScreen || rightEdgeInScreen;
    var isEntirelyOnScreen = topEdgeInScreen && bottomEdgeInScreen && leftEdgeInScreen && rightEdgeInScreen;

    return partial ? isPartiallyOnScreen : isEntirelyOnScreen;

};

$.expr.filters.onscreen = function(elem) {
  return $(elem).isOnScreen(true);
};

$.expr.filters.entireonscreen = function(elem) {
  return $(elem).isOnScreen(true);
};

Maximum Length of Command Line String

From the Microsoft documentation: Command prompt (Cmd. exe) command-line string limitation

On computers running Microsoft Windows XP or later, the maximum length of the string that you can use at the command prompt is 8191 characters.

How to setup Main class in manifest file in jar produced by NetBeans project

I'm going to make a summary of the proposed solutions and the one that helped me!

After reading this bug report: bug in the way NetBeans 6.8 creates the jar for a Java Library Project.

  1. Create a manifest.mf file in my project root

  2. Edit manifest.mf. Mine looked something like this:

    Manifest-Version: 1.0
    Ant-Version: Apache Ant 1.7.1
    Created-By: 16.3-b01 (Sun Microsystems Inc.)
    Main-Class: com.example.MainClass
    Class-Path: lib/lib1.jar lib/lib2.jar
    
  3. Open file /nbproject/project.properties

  4. Add line

    manifest.file=manifest.mf

  5. Clean + Build of project

Now the .jar is successfully build.

Thank you very much vkraemer

Insert node at a certain position in a linked list C++

I had some problems with the insertion process just like you, so here is the code how I have solved the problem:

void add_by_position(int data, int pos)
  {
        link *node = new link;
        link *linker = head;

        node->data = data;
        for (int i = 0; i < pos; i++){
            linker = linker->next;
        }
        node->next = linker;
        linker = head;
        for (int i = 0; i < pos - 1; i++){
            linker = linker->next;
        }
        linker->next = node;
        boundaries++;
    }

Eloquent ->first() if ->exists()

get returns Collection and is rather supposed to fetch multiple rows.

count is a generic way of checking the result:

$user = User::where(...)->first(); // returns Model or null
if (count($user)) // do what you want with $user

// or use this:
$user = User::where(...)->firstOrFail(); // returns Model or throws ModelNotFoundException

// count will works with a collection of course:
$users = User::where(...)->get(); // returns Collection always (might be empty)
if (count($users)) // do what you want with $users

Printing chars and their ASCII-code in C

Nothing can be more simple than this

#include <stdio.h>  

int main()  
{  
    int i;  

    for( i=0 ; i<=255 ; i++ ) /*ASCII values ranges from 0-255*/  
    {  
        printf("ASCII value of character %c = %d\n", i, i);  
    }  

    return 0;  
}   

Source: program to print ASCII value of all characters

How to create cron job using PHP?

This is the best explanation with code in PHP I have found so far:

http://code.tutsplus.com/tutorials/managing-cron-jobs-with-php--net-19428

In short:

Although the syntax of scheduling a new job may seem daunting at first glance, it's actually relatively simple to understand once you break it down. A cron job will always have five columns each of which represent a chronological 'operator' followed by the full path and command to execute:

* * * * * home/path/to/command/the_command.sh

Each of the chronological columns has a specific relevance to the schedule of the task. They are as follows:

Minutes represents the minutes of a given hour, 0-59 respectively.
Hours represents the hours of a given day, 0-23 respectively.
Days represents the days of a given month, 1-31 respectively.
Months represents the months of a given year, 1-12 respectively.
Day of the Week represents the day of the week, Sunday through Saturday, numerically, as 0-6 respectively.

enter image description here

So, for example, if one wanted to schedule a task for 12am on the first day of every month it would look something like this:

0 0 1 * * home/path/to/command/the_command.sh

If we wanted to schedule a task to run every Saturday at 8:30am we'd write it as follows:

30 8 * * 6 home/path/to/command/the_command.sh

There are also a number of operators which can be used to customize the schedule even further:

Commas is used to create a comma separated list of values for any of the cron columns.
Dashes is used to specify a range of values.
Asterisksis used to specify 'all' or 'every' value

Visit the link for the full article, it explains:

  1. What is the format of the cronjob if you want to enter/edit it manually.
  2. How to use PHP with SSH2 library to authenticate as the user, which crontab you are going to edit.
  3. Full PHP class with all necessary methods for authentication, editing and deleting crontab entries.

Adding a parameter to the URL with JavaScript

This was my own attempt, but I'll use the answer by annakata as it seems much cleaner:

function AddUrlParameter(sourceUrl, parameterName, parameterValue, replaceDuplicates)
{
    if ((sourceUrl == null) || (sourceUrl.length == 0)) sourceUrl = document.location.href;
    var urlParts = sourceUrl.split("?");
    var newQueryString = "";
    if (urlParts.length > 1)
    {
        var parameters = urlParts[1].split("&");
        for (var i=0; (i < parameters.length); i++)
        {
            var parameterParts = parameters[i].split("=");
            if (!(replaceDuplicates && parameterParts[0] == parameterName))
            {
                if (newQueryString == "")
                    newQueryString = "?";
                else
                    newQueryString += "&";
                newQueryString += parameterParts[0] + "=" + parameterParts[1];
            }
        }
    }
    if (newQueryString == "")
        newQueryString = "?";
    else
        newQueryString += "&";
    newQueryString += parameterName + "=" + parameterValue;

    return urlParts[0] + newQueryString;
}

Also, I found this jQuery plugin from another post on stackoverflow, and if you need more flexibility you could use that: http://plugins.jquery.com/project/query-object

I would think the code would be (haven't tested):

return $.query.parse(sourceUrl).set(parameterName, parameterValue).toString();

TypeError: 'float' object is not callable

The problem is with -3.7(prof[x]), which looks like a function call (note the parens). Just use a * like this -3.7*prof[x].

invalid use of non-static member function

The simplest fix is to make the comparator function be static:

static int comparator (const Bar & first, const Bar & second);
^^^^^^

When invoking it in Count, its name will be Foo::comparator.

The way you have it now, it does not make sense to be a non-static member function because it does not use any member variables of Foo.

Another option is to make it a non-member function, especially if it makes sense that this comparator might be used by other code besides just Foo.

Checking if date is weekend PHP

For guys like me, who aren't minimalistic, there is a PECL extension called "intl". I use it for idn conversion since it works way better than the "idn" extension and some other n1 classes like "IntlDateFormatter".

Well, what I want to say is, the "intl" extension has a class called "IntlCalendar" which can handle many international countries (e.g. in Saudi Arabia, sunday is not a weekend day). The IntlCalendar has a method IntlCalendar::isWeekend for that. Maybe you guys give it a shot, I like that "it works for almost every country" fact on these intl-classes.

EDIT: Not quite sure but since PHP 5.5.0, the intl extension is bundled with PHP (--enable-intl).

CSS media query to target only iOS devices

Short answer No. CSS is not specific to brands.

Below are the articles to implement for iOS using media only.

https://css-tricks.com/snippets/css/media-queries-for-standard-devices/

http://stephen.io/mediaqueries/

Infact you can use PHP, Javascript to detect the iOS browser and according to that you can call CSS file. For instance

http://www.kevinleary.net/php-detect-ios-mobile-users/

How to find Google's IP address?

If all you are trying to do is find the IP address that corresponds to a domain name, like google.com, this is very easy on every machine connected to the Internet.

Simply run the ping command from any command prompt. Typing something like

ping google.com

will give you (among other things) that information.

How to run .sh on Windows Command Prompt?

you can use also cmder

Cmder is a software package created out of pure frustration over the absence of nice console emulators on Windows. It is based on amazing software, and spiced up with the Monokai color scheme and a custom prompt layout, looking sexy from the start

Screenshot

cmder.net

Bootstrap 3 select input form inline

Thanks to G_money and other suggestions for this excellent solution to input-text with inline dropdown... here's another great solution.

<form class="form-inline" role="form" id="yourformID-form" action="" method="post">
    <div class="input-group">
        <span class="input-group-addon"><i class="fa fa-male"></i></span>

        <div class="form-group">
            <input size="50" maxlength="50" class="form-control" name="q" type="text">          
        </div>

        <div class="form-group">
            <select class="form-control" name="category">
                <option value=""></option>
                <option value="0">select1</option>
                <option value="1">select2</option>
                <option value="2">select3</option>
            </select>           
        </div>
    </div>
</form>

This works with Bootstrap 3: allowing input-text inline with a select dropdown. Here's what it looks like below...

enter image description here

Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference

In all these scenarios outerScopeVar is modified or assigned a value asynchronously or happening in a later time(waiting or listening for some event to occur),for which the current execution will not wait.So all these cases current execution flow results in outerScopeVar = undefined

Let's discuss each examples(I marked the portion which is called asynchronously or delayed for some events to occur):

1.

enter image description here

Here we register an eventlistner which will be executed upon that particular event.Here loading of image.Then the current execution continuous with next lines img.src = 'lolcat.png'; and alert(outerScopeVar); meanwhile the event may not occur. i.e, funtion img.onload wait for the referred image to load, asynchrously. This will happen all the folowing example- the event may differ.

2.

2

Here the timeout event plays the role, which will invoke the handler after the specified time. Here it is 0, but still it registers an asynchronous event it will be added to the last position of the Event Queue for execution, which makes the guaranteed delay.

3.

enter image description here This time ajax callback.

4.

enter image description here

Node can be consider as a king of asynchronous coding.Here the marked function is registered as a callback handler which will be executed after reading the specified file.

5.

enter image description here

Obvious promise (something will be done in future) is asynchronous. see What are the differences between Deferred, Promise and Future in JavaScript?

https://www.quora.com/Whats-the-difference-between-a-promise-and-a-callback-in-Javascript

How to skip the OPTIONS preflight request?

When performing certain types of cross-domain AJAX requests, modern browsers that support CORS will insert an extra "preflight" request to determine whether they have permission to perform the action. From example query:

$http.get( ‘https://example.com/api/v1/users/’ +userId,
  {params:{
           apiKey:’34d1e55e4b02e56a67b0b66’
          }
  } 
);

As a result of this fragment we can see that the address was sent two requests (OPTIONS and GET). The response from the server includes headers confirming the permissibility the query GET. If your server is not configured to process an OPTIONS request properly, client requests will fail. For example:

Access-Control-Allow-Credentials: true
Access-Control-Allow-Headers: accept, origin, x-requested-with, content-type
Access-Control-Allow-Methods: DELETE
Access-Control-Allow-Methods: OPTIONS
Access-Control-Allow-Methods: PUT
Access-Control-Allow-Methods: GET
Access-Control-Allow-Methods: POST
Access-Control-Allow-Orgin: *
Access-Control-Max-Age: 172800
Allow: PUT
Allow: OPTIONS
Allow: POST
Allow: DELETE
Allow: GET

How may I align text to the left and text to the right in the same line?

HTML FILE:

<div class='left'> Left Aligned </div> 
<div class='right'> Right Aligned </div>

CSS FILE:

.left
{
  float: left;
}

.right
{
  float: right;
}

and you are done ....

Can't push to the heroku

If you are using django app to deploy on heroku

make sure to put request library in the requirements.txt file.

Remap values in pandas column with a dict

DSM has the accepted answer, but the coding doesn't seem to work for everyone. Here is one that works with the current version of pandas (0.23.4 as of 8/2018):

import pandas as pd

df = pd.DataFrame({'col1': [1, 2, 2, 3, 1],
            'col2': ['negative', 'positive', 'neutral', 'neutral', 'positive']})

conversion_dict = {'negative': -1, 'neutral': 0, 'positive': 1}
df['converted_column'] = df['col2'].replace(conversion_dict)

print(df.head())

You'll see it looks like:

   col1      col2  converted_column
0     1  negative                -1
1     2  positive                 1
2     2   neutral                 0
3     3   neutral                 0
4     1  positive                 1

The docs for pandas.DataFrame.replace are here.

Eclipse executable launcher error: Unable to locate companion shared library

I got similar error sometime back. I had copied the eclipse setup from another laptop to mine. The issue with my setup was that path of the "--launcher.library" in the eclipse.ini file. The path in --launcher.library was that of the old machine and hence I was getting the error

I changed the path of "--launcher.library" in eclipse.ini to the path of eclipse on my laptop and the issue got resolved. I hope this is helpful to someone is getting this error.

Re-enabling window.alert in Chrome

In Chrome Browser go to setting , clear browsing history and then reload the page

git: fatal: I don't handle protocol '??http'

Please do not copy from the clipboard . Just copy the url from your browser's location / Address bar .enter image description here

Comma separated results in SQL

For Sql Server 2017 and later you can use the new STRING_AGG function

https://docs.microsoft.com/en-us/sql/t-sql/functions/string-agg-transact-sql

The following example replaces null values with 'N/A' and returns the names separated by commas in a single result cell.

SELECT STRING_AGG ( ISNULL(FirstName,'N/A'), ',') AS csv 
FROM Person.Person;

Here is the result set.

John,N/A,Mike,Peter,N/A,N/A,Alice,Bob

Perhaps a more common use case is to group together and then aggregate, just like you would with SUM, COUNT or AVG.

SELECT a.articleId, title, STRING_AGG (tag, ',') AS tags 
FROM dbo.Article AS a       
LEFT JOIN dbo.ArticleTag AS t 
    ON a.ArticleId = t.ArticleId 
GROUP BY a.articleId, title;

jQuery find element by data attribute value

You can also use .filter()

$('.slide-link').filter('[data-slide="0"]').addClass('active');

Python; urllib error: AttributeError: 'bytes' object has no attribute 'read'

I got the same error {AttributeError: 'bytes' object has no attribute 'read'} in python3. This worked for me later without using json:

from urllib.request import urlopen
from bs4 import BeautifulSoup

url = 'https://someurl/'
page = urlopen(url)
html = page.read()
soup = BeautifulSoup(html)
print(soup.prettify('latin-1'))

data.frame rows to a list

Seems a current version of the purrr (0.2.2) package is the fastest solution:

by_row(x, function(v) list(v)[[1L]], .collate = "list")$.out

Let's compare the most interesting solutions:

data("Batting", package = "Lahman")
x <- Batting[1:10000, 1:10]
library(benchr)
library(purrr)
benchmark(
    split = split(x, seq_len(.row_names_info(x, 2L))),
    mapply = .mapply(function(...) structure(list(...), class = "data.frame", row.names = 1L), x, NULL),
    purrr = by_row(x, function(v) list(v)[[1L]], .collate = "list")$.out
)

Rsults:

Benchmark summary:
Time units : milliseconds 
  expr n.eval   min  lw.qu median   mean  up.qu  max  total relative
 split    100 983.0 1060.0 1130.0 1130.0 1180.0 1450 113000     34.3
mapply    100 826.0  894.0  963.0  972.0 1030.0 1320  97200     29.3
 purrr    100  24.1   28.6   32.9   44.9   40.5  183   4490      1.0

Also we can get the same result with Rcpp:

#include <Rcpp.h>
using namespace Rcpp;

// [[Rcpp::export]]
List df2list(const DataFrame& x) {
    std::size_t nrows = x.rows();
    std::size_t ncols = x.cols();
    CharacterVector nms = x.names();
    List res(no_init(nrows));
    for (std::size_t i = 0; i < nrows; ++i) {
        List tmp(no_init(ncols));
        for (std::size_t j = 0; j < ncols; ++j) {
            switch(TYPEOF(x[j])) {
                case INTSXP: {
                    if (Rf_isFactor(x[j])) {
                        IntegerVector t = as<IntegerVector>(x[j]);
                        RObject t2 = wrap(t[i]);
                        t2.attr("class") = "factor";
                        t2.attr("levels") = t.attr("levels");
                        tmp[j] = t2;
                    } else {
                        tmp[j] = as<IntegerVector>(x[j])[i];
                    }
                    break;
                }
                case LGLSXP: {
                    tmp[j] = as<LogicalVector>(x[j])[i];
                    break;
                }
                case CPLXSXP: {
                    tmp[j] = as<ComplexVector>(x[j])[i];
                    break;
                }
                case REALSXP: {
                    tmp[j] = as<NumericVector>(x[j])[i];
                    break;
                }
                case STRSXP: {
                    tmp[j] = as<std::string>(as<CharacterVector>(x[j])[i]);
                    break;
                }
                default: stop("Unsupported type '%s'.", type2name(x));
            }
        }
        tmp.attr("class") = "data.frame";
        tmp.attr("row.names") = 1;
        tmp.attr("names") = nms;
        res[i] = tmp;
    }
    res.attr("names") = x.attr("row.names");
    return res;
}

Now caompare with purrr:

benchmark(
    purrr = by_row(x, function(v) list(v)[[1L]], .collate = "list")$.out,
    rcpp = df2list(x)
)

Results:

Benchmark summary:
Time units : milliseconds 
 expr n.eval  min lw.qu median mean up.qu   max total relative
purrr    100 25.2  29.8   37.5 43.4  44.2 159.0  4340      1.1
 rcpp    100 19.0  27.9   34.3 35.8  37.2  93.8  3580      1.0

CSV API for Java

For the last enterprise application I worked on that needed to handle a notable amount of CSV -- a couple of months ago -- I used SuperCSV at sourceforge and found it simple, robust and problem-free.

How to Correctly handle Weak Self in Swift Blocks with Arguments

**EDITED for Swift 4.2:

As @Koen commented, swift 4.2 allows:

guard let self = self else {
   return // Could not get a strong reference for self :`(
}

// Now self is a strong reference
self.doSomething()

P.S.: Since I am having some up-votes, I would like to recommend the reading about escaping closures.

EDITED: As @tim-vermeulen has commented, Chris Lattner said on Fri Jan 22 19:51:29 CST 2016, this trick should not be used on self, so please don't use it. Check the non escaping closures info and the capture list answer from @gbk.**

For those who use [weak self] in capture list, note that self could be nil, so the first thing I do is check that with a guard statement

guard let `self` = self else {
   return
}
self.doSomething()

If you are wondering what the quote marks are around self is a pro trick to use self inside the closure without needing to change the name to this, weakSelf or whatever.

how to break the _.each function in underscore.js

You can have a look to _.some instead of _.each. _.some stops traversing the list once a predicate is true. Result(s) can be stored in an external variable.

_.some([1, 2, 3], function(v) {
    if (v == 2) return true;
})

See http://underscorejs.org/#some

How to check if an excel cell is empty using Apache POI?

Cell cell = row.getCell(x, Row.CREATE_NULL_AS_BLANK);

This trick helped me a lot, see if it's useful for you

moment.js 24h format

You can use

 moment("15", "hh").format('LT') 

to convert the time to 12 hours format like this 3:00 PM

Android widget: How to change the text of a button

use the exchange using java. setText = "...", for class java there are many more methods for implementation.

    //button fechar
    btnclose.setEnabled(false);
    btnclose.setText("FECHADO");
    View.OnClickListener close = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (btnclose.isClickable()) {
                btnOpen.setEnabled(true);
                btnOpen.setText("ABRIR");
                btnclose.setEnabled(false);
                btnclose.setText("FECHADO");
            } else {
                btnOpen.setEnabled(false);
                btnOpen.setText("ABERTO");
                btnclose.setEnabled(true);
                btnclose.setText("FECHAR");
            }

            Toast.makeText(getActivity(), "FECHADO", Toast.LENGTH_SHORT).show();
        }
    };

    btnclose.setOnClickListener(close); 

How to clear form after submit in Angular 2?

To angular version 4, you can use this:

this.heroForm.reset();

But, you could need a initial value like:

ngOnChanges() {
 this.heroForm.reset({
  name: this.hero.name, //Or '' to empty initial value. 
  address: this.hero.addresses[0] || new Address()
 });
}

It is important to resolve null problem in your object reference.

reference link, Search for "reset the form flags".

PHP class: Global variable as property in class

Simply use the global keyword.

e.g.:

class myClass() {
    private function foo() {
        global $MyNumber;
        ...

$MyNumber will then become accessible (and indeed modifyable) within that method.

However, the use of globals is often frowned upon (they can give off a bad code smell), so you might want to consider using a singleton class to store anything of this nature. (Then again, without knowing more about what you're trying to achieve this might be a very bad idea - a define could well be more useful.)

How do you kill a Thread in Java?

'Killing a thread' is not the right phrase to use. Here is one way we can implement graceful completion/exit of the thread on will:

Runnable which I used:

class TaskThread implements Runnable {

    boolean shouldStop;

    public TaskThread(boolean shouldStop) {
        this.shouldStop = shouldStop;
    }

    @Override
    public void run() {

        System.out.println("Thread has started");

        while (!shouldStop) {
            // do something
        }

        System.out.println("Thread has ended");

    }

    public void stop() {
        shouldStop = true;
    }

}

The triggering class:

public class ThreadStop {

    public static void main(String[] args) {

        System.out.println("Start");

        // Start the thread
        TaskThread task = new TaskThread(false);
        Thread t = new Thread(task);
        t.start();

        // Stop the thread
        task.stop();

        System.out.println("End");

    }

}

Popup window in PHP?

For a popup javascript is required. Put this in your header:

<script>
function myFunction()
{
alert("I am an alert box!"); // this is the message in ""
}
</script>

And this in your body:

<input type="button" onclick="myFunction()" value="Show alert box">

When the button is pressed a box pops up with the message set in the header.

This can be put in any html or php file without the php tags.

-----EDIT-----

To display it using php try this:

<?php echo '<script>myfunction()</script>'; ?>

It may not be 100% correct but the principle is the same.

To display different messages you can either create lots of functions or you can pass a variable in to the function when you call it.

Argument of type 'X' is not assignable to parameter of type 'X'

I was getting this one on this case

...
.then((error: any, response: any) => {
  console.info('document error: ', error);
  console.info('documenr response: ', response);
  return new MyModel();
})
...

on this case making parameters optional would make ts stop complaining

.then((error?: any, response?: any) => {

How to compare only Date without Time in DateTime types in Linq to SQL with Entity Framework?

In your join or where clause, use the Date property of the column. Behind the scenes, this executes a CONVERT(DATE, <expression>) operation. This should allow you to compare dates without the time.

PHP: Calling another class' method

You would need to have an instance of ClassA within ClassB or have ClassB inherit ClassA

class ClassA {
    public function getName() {
      echo $this->name;
    }
}

class ClassB extends ClassA {
    public function getName() {
      parent::getName();
    }
}

Without inheritance or an instance method, you'd need ClassA to have a static method

class ClassA {
  public static function getName() {
    echo "Rawkode";
  }
}

--- other file ---

echo ClassA::getName();

If you're just looking to call the method from an instance of the class:

class ClassA {
  public function getName() {
    echo "Rawkode";
  }
}

--- other file ---

$a = new ClassA();
echo $a->getName();

Regardless of the solution you choose, require 'ClassA.php is needed.

(.text+0x20): undefined reference to `main' and undefined reference to function

This error means that, while linking, compiler is not able to find the definition of main() function anywhere.

In your makefile, the main rule will expand to something like this.

main: producer.o consumer.o AddRemove.o
   gcc -pthread -Wall -o producer.o consumer.o AddRemove.o

As per the gcc manual page, the use of -o switch is as below

-o file     Place output in file file. This applies regardless to whatever sort of output is being produced, whether it be an executable file, an object file, an assembler file or preprocessed C code. If -o is not specified, the default is to put an executable file in a.out.

It means, gcc will put the output in the filename provided immediate next to -o switch. So, here instead of linking all the .o files together and creating the binary [main, in your case], its creating the binary as producer.o, linking the other .o files. Please correct that.

Angular2 Material Dialog css, dialog size

You can inspect the dialog element with dev tools and see what classes are applied on mdDialog.

For example, .md-dialog-container is the main classe of the MDDialog and has padding: 24px

you can create a custom CSS to overwrite whatever you want

.md-dialog-container {
      background-color: #000;
      width: 250px;
      height: 250px
}

In my opinion this is not a good option and probably goes against Material guide but since it doesn't have all features it has in it's previous version, you should do what you think is best for you.

if arguments is equal to this string, define a variable like this string

You can use either "=" or "==" operators for string comparison in bash. The important factor is the spacing within the brackets. The proper method is for brackets to contain spacing within, and operators to contain spacing around. In some instances different combinations work; however, the following is intended to be a universal example.

if [ "$1" == "something" ]; then     ## GOOD

if [ "$1" = "something" ]; then      ## GOOD

if [ "$1"="something" ]; then        ## BAD (operator spacing)

if ["$1" == "something"]; then       ## BAD (bracket spacing)

Also, note double brackets are handled slightly differently compared to single brackets ...

if [[ $a == z* ]]; then   # True if $a starts with a "z" (pattern matching).
if [[ $a == "z*" ]]; then # True if $a is equal to z* (literal matching).

if [ $a == z* ]; then     # File globbing and word splitting take place.
if [ "$a" == "z*" ]; then # True if $a is equal to z* (literal matching).

I hope that helps!

Sorting a List<int>

Sort a list of integers descending

class Program
    {       
        private class SortIntDescending : IComparer<int>
        {
            int IComparer<int>.Compare(int a, int b) //implement Compare
            {              
                if (a > b)
                    return -1; //normally greater than = 1
                if (a < b)
                    return 1; // normally smaller than = -1
                else
                    return 0; // equal
            }
        }

        static List<int> intlist = new List<int>(); // make a list

        static void Main(string[] args)
        {
            intlist.Add(5); //fill the list with 5 ints
            intlist.Add(3);
            intlist.Add(5);
            intlist.Add(15);
            intlist.Add(7);

            Console.WriteLine("Unsorted list :");
            Printlist(intlist);

            Console.WriteLine();
            // intlist.Sort(); uses the default Comparer, which is ascending
            intlist.Sort(new SortIntDescending()); //sort descending

            Console.WriteLine("Sorted descending list :");
            Printlist(intlist);

            Console.ReadKey(); //wait for keydown
        }

        static void Printlist(List<int> L)
        {
            foreach (int i in L) //print on the console
            {
                Console.WriteLine(i);
            }
        }
    }

Are lists thread-safe?

To clarify a point in Thomas' excellent answer, it should be mentioned that append() is thread safe.

This is because there is no concern that data being read will be in the same place once we go to write to it. The append() operation does not read data, it only writes data to the list.

How to find difference between two columns data?

Yes, you can select the data, calculate the difference, and insert all values in the other table:

insert into #temp2 (Difference)
select previous - Present
from #TEMP1

How to get distinct values from an array of objects in JavaScript?

my two cents on this function:

var result = [];
for (var len = array.length, i = 0; i < len; ++i) {
  var age = array[i].age;
  if (result.indexOf(age) > -1) continue;
  result.push(age);
}

You can see the result here (Method 8) http://jsperf.com/distinct-values-from-array/3

Reference list item by index within Django template?

{{ data.0 }} should work.

Let's say you wrote data.obj django tries data.obj and data.obj(). If they don't work it tries data["obj"]. In your case data[0] can be written as {{ data.0 }}. But I recommend you to pull data[0] in the view and send it as separate variable.

PHP: trying to create a new line with "\n"

Assuming you're viewing the output in a web browser you have at least two options:

  1. Surround your text block with <pre> statements

  2. Change your \n to an HTML <br> tag (<br/> will also do)

Prevent text selection after double click

If you are trying to completely prevent selecting text by any method as well as on a double click only, you can use the user-select: none css attribute. I have tested in Chrome 68, but according to https://caniuse.com/#search=user-select it should work in the other current normal user browsers.

Behaviorally, in Chrome 68 it is inherited by child elements, and did not allow selecting an element's contained text even if when text surrounding and including the element was selected.

How to use JUnit to test asynchronous processes

There's nothing inherently wrong with testing threaded/async code, particularly if threading is the point of the code you're testing. The general approach to testing this stuff is to:

  • Block the main test thread
  • Capture failed assertions from other threads
  • Unblock the main test thread
  • Rethrow any failures

But that's a lot of boilerplate for one test. A better/simpler approach is to just use ConcurrentUnit:

  final Waiter waiter = new Waiter();

  new Thread(() -> {
    doSomeWork();
    waiter.assertTrue(true);
    waiter.resume();
  }).start();

  // Wait for resume() to be called
  waiter.await(1000);

The benefit of this over the CountdownLatch approach is that it's less verbose since assertion failures that occur in any thread are properly reported to the main thread, meaning the test fails when it should. A writeup that compares the CountdownLatch approach to ConcurrentUnit is here.

I also wrote a blog post on the topic for those who want to learn a bit more detail.

Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

ddd is a graphical front-end to gdb that is pretty nice. One of the down sides is a classic X interface, but I seem to recall it being pretty intuitive.

Detect if the app was launched/opened from a push notification

The problem with this question is that "opening" the app isn't well-defined. An app is either cold-launched from a not-running state, or it's reactivated from an inactive state (e.g. from switching back to it from another app). Here's my solution to distinguish all of these possible states:

typedef NS_ENUM(NSInteger, MXAppState) {
    MXAppStateActive = 0,
    MXAppStateReactivated = 1,
    MXAppStateLaunched = 2
};

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // ... your custom launch stuff
    [[MXDefaults instance] setDateOfLastLaunch:[NSDate date]];
    // ... more custom launch stuff
}

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
    // Through a lot of trial and error (by showing alerts), I can confirm that on iOS 10
    // this method is only called when the app has been launched from a push notification
    // or when the app is already in the Active state.  When you receive a push
    // and then launch the app from the icon or apps view, this method is _not_ called.
    // So with 99% confidence, it means this method is called in one of the 3 mutually exclusive cases
    //    1) we are active in the foreground, no action was taken by the user
    //    2) we were 'launched' from an inactive state (so we may already be in the main section) by a tap
    //       on a push notification
    //    3) we were truly launched from a not running state by a tap on a push notification
    // Beware that cases (2) and (3) may both show UIApplicationStateInactive and cant be easily distinguished.
    // We check the last launch date to distinguish (2) and (3).

    MXAppState appState = [self mxAppStateFromApplicationState:[application applicationState]];
    //... your app's logic
}

- (MXAppState)mxAppStateFromApplicationState:(UIApplicationState)state {
    if (state == UIApplicationStateActive) {
        return MXAppStateActive;
    } else {
        NSDate* lastLaunchDate = [[MXDefaults instance] dateOfLastLaunch];
        if (lastLaunchDate && [[NSDate date] timeIntervalSinceDate:lastLaunchDate] < 0.5f) {
            return MXAppStateLaunched;
        } else {
            return MXAppStateReactivated;
        }
    }
    return MXAppStateActive;
}

And MXDefaults is just a little wrapper for NSUserDefaults.

Get the current language in device

here is code to get device country. Compatible with all versions of android even oreo.

Solution: if user does not have sim card than get country he is used during phone setup , or current language selection.

public static String getDeviceCountry(Context context) {
    String deviceCountryCode = null;

    final TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);

        if(tm != null) {
            deviceCountryCode = tm.getNetworkCountryIso();
        }

    if (deviceCountryCode != null && deviceCountryCode.length() <=3) {
        deviceCountryCode = deviceCountryCode.toUpperCase();
    }
    else {
        deviceCountryCode = ConfigurationCompat.getLocales(Resources.getSystem().getConfiguration()).get(0).getCountry().toUpperCase();
    }

  //  Log.d("countryCode","  : " + deviceCountryCode );
    return deviceCountryCode;
}

How do you do exponentiation in C?

Similar to an earlier answer, this will handle positive and negative integer powers of a double nicely.

double intpow(double a, int b)
{
  double r = 1.0;
  if (b < 0)
  {
    a = 1.0 / a;
    b = -b;
  }
  while (b)
  {
    if (b & 1)
      r *= a;
    a *= a;
    b >>= 1;
  }
  return r;
}

How to select a column name with a space in MySQL

I got here with an MS Access problem.

Backticks are good for MySQL, but they create weird errors, like "Invalid Query Name: Query1" in MS Access, for MS Access only, use square brackets:

It should look like this

SELECT Customer.[Customer ID], Customer.[Full Name] ...

Reset ID autoincrement ? phpmyadmin

I agree with rpd, this is the answer and can be done on a regular basis to clean up your id column that is getting bigger with only a few hundred rows of data, but maybe an id of 34444543!, as the data is deleted out regularly but id is incremented automatically.

ALTER TABLE users DROP id

The above sql can be run via sql query or as php. This will delete the id column.

Then re add it again, via the code below:

ALTER TABLE  `users` ADD `id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY FIRST

Place this in a piece of code that may get run maybe in an admin panel, so when anyone enters that page it will run this script that auto cleans your database, and tidys it.

How to change Toolbar Navigation and Overflow Menu icons (appcompat v7)?

which theme you have used in activity add below one line code

for white

<style name="AppTheme.NoActionBar">
      <item name="android:tint">#ffffff</item>
  </style>

or 
 <style name="AppThemeName" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="android:tint">#ffffff</item>
</style>

for black

   <style name="AppTheme.NoActionBar">
      <item name="android:tint">#000000</item>
  </style>

or 
 <style name="AppThemeName" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="android:tint">#000000</item>
</style>

Change line width of lines in matplotlib pyplot legend

@ImportanceOfBeingErnest 's answer is good if you only want to change the linewidth inside the legend box. But I think it is a bit more complex since you have to copy the handles before changing legend linewidth. Besides, it can not change the legend label fontsize. The following two methods can not only change the linewidth but also the legend label text font size in a more concise way.

Method 1

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the individual lines inside legend and set line width
for line in leg.get_lines():
    line.set_linewidth(4)
# get label texts inside legend and set font size
for text in leg.get_texts():
    text.set_fontsize('x-large')

plt.savefig('leg_example')
plt.show()

Method 2

import numpy as np
import matplotlib.pyplot as plt

# make some data
x = np.linspace(0, 2*np.pi)

y1 = np.sin(x)
y2 = np.cos(x)

# plot sin(x) and cos(x)
fig = plt.figure()
ax  = fig.add_subplot(111)
ax.plot(x, y1, c='b', label='y1')
ax.plot(x, y2, c='r', label='y2')

leg = plt.legend()
# get the lines and texts inside legend box
leg_lines = leg.get_lines()
leg_texts = leg.get_texts()
# bulk-set the properties of all lines and texts
plt.setp(leg_lines, linewidth=4)
plt.setp(leg_texts, fontsize='x-large')
plt.savefig('leg_example')
plt.show()

The above two methods produce the same output image:

output image

How can I color a UIImage in Swift?

Swift 3 extension wrapper from @Nikolai Ruhe answer.

extension UIImageView {

    func maskWith(color: UIColor) {
        guard let tempImage = image?.withRenderingMode(.alwaysTemplate) else { return }
        image = tempImage
        tintColor = color
    }

}

It can be use for UIButton as well, e.g:

button.imageView?.maskWith(color: .blue)

How can a LEFT OUTER JOIN return more records than exist in the left table?

If you need just any one row from the right side

SELECT SuspReason, SiteID FROM(
    SELECT SUSP.Susp_Visits.SuspReason, SUSP.Susp_Visits.SiteID, ROW_NUMBER()
    OVER(PARTITION BY SUSP.Susp_Visits.SiteID) AS rn
    FROM SUSP.Susp_Visits
    LEFT OUTER JOIN DATA.Dim_Member ON SUSP.Susp_Visits.MemID = DATA.Dim_Member.MembershipNum
) AS t
WHERE rn=1

or just

SELECT SUSP.Susp_Visits.SuspReason, SUSP.Susp_Visits.SiteID
FROM SUSP.Susp_Visits WHERE EXISTS(
    SELECT DATA.Dim_Member WHERE SUSP.Susp_Visits.MemID = DATA.Dim_Member.MembershipNum
)

Extract Month and Year From Date in R

The zoo package has the function of as.yearmon can help to convert.

require(zoo)

df$ym<-as.yearmon(df$date, "%Y %m")

Button text toggle in jquery

You can also use math function to do this

var i = 0;
$('#button').on('click', function() {
    if (i++ % 2 == 0) {
        $(this).val("Push me!");
    } else {
        $(this).val("Don't push me!");
    }
});

DEMO

Is there a RegExp.escape function in JavaScript?

The functions in the other answers are overkill for escaping entire regular expressions (they may be useful for escaping parts of regular expressions that will later be concatenated into bigger regexps).

If you escape an entire regexp and are done with it, quoting the metacharacters that are either standalone (., ?, +, *, ^, $, |, \) or start something ((, [, {) is all you need:

String.prototype.regexEscape = function regexEscape() {
  return this.replace(/[.?+*^$|({[\\]/g, '\\$&');
};

And yes, it's disappointing that JavaScript doesn't have a function like this built-in.

Android Studio - Importing external Library/Jar

In Android Studio (mine is 2.3.1) go to File - Project Structure:

enter image description here

What's the meaning of System.out.println in Java?

System is a class, that has a public static field out. So it's more like

class System 
{
    public static PrintStream out;
}

class PrintStream
{
    public void println ...
}

This is a slight oversimplification, as the PrintStream class is actually in the java.io package, but it's good enough to show the relationship of stuff.

Comparing boxed Long values 127 and 128

TL;DR

Java caches boxed Integer instances from -128 to 127. Since you are using == to compare objects references instead of values, only cached objects will match. Either work with long unboxed primitive values or use .equals() to compare your Long objects.

Long (pun intended) version

Why there is problem in comparing Long variable with value greater than 127? If the data type of above variable is primitive (long) then code work for all values.

Java caches Integer objects instances from the range -128 to 127. That said:

  • If you set to N Long variables the value 127 (cached), the same object instance will be pointed by all references. (N variables, 1 instance)
  • If you set to N Long variables the value 128 (not cached), you will have an object instance pointed by every reference. (N variables, N instances)

That's why this:

Long val1 = 127L;
Long val2 = 127L;

System.out.println(val1 == val2);

Long val3 = 128L;
Long val4 = 128L;

System.out.println(val3 == val4);

Outputs this:

true
false

For the 127L value, since both references (val1 and val2) point to the same object instance in memory (cached), it returns true.

On the other hand, for the 128 value, since there is no instance for it cached in memory, a new one is created for any new assignments for boxed values, resulting in two different instances (pointed by val3 and val4) and returning false on the comparison between them.

That happens solely because you are comparing two Long object references, not long primitive values, with the == operator. If it wasn't for this Cache mechanism, these comparisons would always fail, so the real problem here is comparing boxed values with == operator.

Changing these variables to primitive long types will prevent this from happening, but in case you need to keep your code using Long objects, you can safely make these comparisons with the following approaches:

System.out.println(val3.equals(val4));                     // true
System.out.println(val3.longValue() == val4.longValue());  // true
System.out.println((long)val3 == (long)val4);              // true

(Proper null checking is necessary, even for castings)

IMO, it's always a good idea to stick with .equals() methods when dealing with Object comparisons.

Reference links:

How do I install Composer on a shared hosting?

SIMPLE SOLUTION (tested on Red Hat):

run command: curl -sS https://getcomposer.org/installer | php

to use it: php composer.phar

SYSTEM WIDE SOLLUTION (tested on Red Hat):

run command: mv composer.phar /usr/local/bin/composer

to use it: composer update

now you can call composer from any directory.

Source: http://www.agix.com.au/install-composer-on-centosredhat/