Programs & Examples On #Vds

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

Claiming that the C++ compiler can produce more optimal code than a competent assembly language programmer is a very bad mistake. And especially in this case. The human always can make the code better than the compiler can, and this particular situation is a good illustration of this claim.

The timing difference you're seeing is because the assembly code in the question is very far from optimal in the inner loops.

(The below code is 32-bit, but can be easily converted to 64-bit)

For example, the sequence function can be optimized to only 5 instructions:

    .seq:
        inc     esi                 ; counter
        lea     edx, [3*eax+1]      ; edx = 3*n+1
        shr     eax, 1              ; eax = n/2
        cmovc   eax, edx            ; if CF eax = edx
        jnz     .seq                ; jmp if n<>1

The whole code looks like:

include "%lib%/freshlib.inc"
@BinaryType console, compact
options.DebugMode = 1
include "%lib%/freshlib.asm"

start:
        InitializeAll
        mov ecx, 999999
        xor edi, edi        ; max
        xor ebx, ebx        ; max i

    .main_loop:

        xor     esi, esi
        mov     eax, ecx

    .seq:
        inc     esi                 ; counter
        lea     edx, [3*eax+1]      ; edx = 3*n+1
        shr     eax, 1              ; eax = n/2
        cmovc   eax, edx            ; if CF eax = edx
        jnz     .seq                ; jmp if n<>1

        cmp     edi, esi
        cmovb   edi, esi
        cmovb   ebx, ecx

        dec     ecx
        jnz     .main_loop

        OutputValue "Max sequence: ", edi, 10, -1
        OutputValue "Max index: ", ebx, 10, -1

        FinalizeAll
        stdcall TerminateAll, 0

In order to compile this code, FreshLib is needed.

In my tests, (1 GHz AMD A4-1200 processor), the above code is approximately four times faster than the C++ code from the question (when compiled with -O0: 430 ms vs. 1900 ms), and more than two times faster (430 ms vs. 830 ms) when the C++ code is compiled with -O3.

The output of both programs is the same: max sequence = 525 on i = 837799.

Add ripple effect to my button with button background color?

try this

<Button
            android:id="@+id/btn_location"
            android:layout_width="121dp"
            android:layout_height="38dp"
            android:layout_gravity="center"
            android:layout_marginBottom="24dp"
            android:layout_marginTop="24dp"
            android:foreground="?attr/selectableItemBackgroundBorderless"
            android:clickable="true"
            android:background="@drawable/btn_corner"
            android:gravity="center_vertical|center_horizontal"
            android:paddingLeft="13dp"
            android:paddingRight="13dp"
            android:text="Save"
            android:textColor="@color/color_white" />

How can I run Android emulator for Intel x86 Atom without hardware acceleration on Windows 8 for API 21 and 19?

Is there any way that I can start android emulator for intel x86 atom Without hardware acceleration on windows 8

Not with the standard Android SDK emulator, as it requires Intel's HAXM, and HAXM wants virtualization extensions to be enabled.

Whether Genymotion or something else from another independent developer can support your desired combination, I cannot say.

How do I set ANDROID_SDK_HOME environment variable?

Android SDK

Installing the Android SDK is also necessary. The Android SDK provides you the API libraries and developer tools necessary to build, test, and debug apps for Android.

Cordova requires the ANDROID_HOME environment variable to be set. This should point to the [ANDROID_SDK_DIR]\android-sdk directory (for example c:\android\android-sdk).

Next, update your PATH to include the tools/ and platform-tools/ folder in that folder. So, using ANDROID_HOME, you would add both %ANDROID_HOME%\tools and %ANDROID_HOME%\platform-tools.

Reference : http://ionicframework.com/docs/v1/guide/installation.html

C free(): invalid pointer

You can't call free on the pointers returned from strsep. Those are not individually allocated strings, but just pointers into the string s that you've already allocated. When you're done with s altogether, you should free it, but you do not have to do that with the return values of strsep.

Android Stop Emulator from Command Line

adb kill-server will kill all emulators and restart the server clean.

set serveroutput on in oracle procedure

First add next code in your sp:

BEGIN
    dbms_output.enable();
    dbms_output.put_line ('TEST LINE'); 
END;

Compile your code in your Oracle SQL developer. So go to Menu View--> dbms output. Click on Icon Green Plus and select your schema. Run your sp now.

Java - Convert image to Base64

I realize that this is an old question but perhaps someone will find my code sample useful. This code encodes a file in Base64 then decodes it and saves it in a new location.

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;

import org.apache.commons.codec.binary.Base64;

public class Base64Example {

    public static void main(String[] args) {

        Base64Example tempObject = new Base64Example();

        // convert file to regular byte array
        byte[] codedFile = tempObject.convertFileToByteArray("your_input_file_path");

        // encoded file in Base64
        byte[] encodedFile = Base64.encodeBase64(codedFile);

        // print out the byte array
        System.out.println(Arrays.toString(encodedFile));

        // print the encoded String
        System.out.println(encodedFile);

        // decode file back to regular byte array
        byte[] decodedByteArray = Base64.decodeBase64(encodedFile);

        // save decoded byte array to a file
        boolean success = tempObject.saveFileFromByteArray("your_output_file_path", decodedByteArray);

        // print out success
        System.out.println("success : " + success);
    }

    public byte[] convertFileToByteArray(String filePath) {

        Path path = Paths.get(filePath);

        byte[] codedFile = null;

        try {
            codedFile = Files.readAllBytes(path);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return codedFile;
    }

    public boolean saveFileFromByteArray(String filePath, byte[] decodedByteArray) {

        boolean success = false;

        Path path = Paths.get(filePath);

        try {
            Files.write(path, decodedByteArray);
            success = true;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return success;
    }
}

Can someone explain mappedBy in JPA and Hibernate?

MappedBy signals hibernate that the key for the relationship is on the other side.

This means that although you link 2 tables together, only 1 of those tables has a foreign key constraint to the other one. MappedBy allows you to still link from the table not containing the constraint to the other table.

How do files get into the External Dependencies in Visual Studio C++?

To resolve external dependencies within project. below things are important..
1. The compiler should know that where are header '.h' files located in workspace.
2. The linker able to find all specified  all '.lib' files & there names for current project.

So, Developer has to specify external dependencies for Project as below..

1. Select Project in Solution explorer.

2 . Project Properties -> Configuration Properties -> C/C++ -> General
specify all header files in "Additional Include Directories".

3.  Project Properties -> Configuration Properties -> Linker -> General
specify relative path for all lib files in "Additional Library Directories".

enter image description here enter image description here

A fatal error has been detected by the Java Runtime Environment: SIGSEGV, libjvm

add new server (tomcat) with different location. if i am not make mistake you are run multiple project with same tomcat and add same tomcat server on same location ..

add new tomcat for each new workspace.

Error: free(): invalid next size (fast):

It means that you have a memory error. You may be trying to free a pointer that wasn't allocated by malloc (or delete an object that wasn't created by new) or you may be trying to free/delete such an object more than once. You may be overflowing a buffer or otherwise writing to memory to which you shouldn't be writing, causing heap corruption.

Any number of programming errors can cause this problem. You need to use a debugger, get a backtrace, and see what your program is doing when the error occurs. If that fails and you determine you have corrupted the heap at some previous point in time, you may be in for some painful debugging (it may not be too painful if the project is small enough that you can tackle it piece by piece).

How to update a plot in matplotlib?

All of the above might be true, however for me "online-updating" of figures only works with some backends, specifically wx. You just might try to change to this, e.g. by starting ipython/pylab by ipython --pylab=wx! Good luck!

Print to the same line and not a new line?

For Python 3.6+ and for any list rather than just ints, as well as using the entire width of your console window and not crossing over to a new line, you could use the following:

note: please be informed, that the function get_console_with() will work only on Linux based systems, and as such you have to rewrite it to work on Windows.

import os
import time

def get_console_width():
    """Returns the width of console.

    NOTE: The below implementation works only on Linux-based operating systems.
    If you wish to use it on another OS, please make sure to modify it appropriately.
    """
    return int(os.popen('stty size', 'r').read().split()[1])


def range_with_progress(list_of_elements):
    """Iterate through list with a progress bar shown in console."""

    # Get the total number of elements of the given list.
    total = len(list_of_elements)
    # Get the width of currently used console. Subtract 2 from the value for the
    # edge characters "[" and "]"
    max_width = get_console_width() - 2
    # Start iterating over the list.
    for index, element in enumerate(list_of_elements):
        # Compute how many characters should be printed as "done". It is simply
        # a percentage of work done multiplied by the width of the console. That
        # is: if we're on element 50 out of 100, that means we're 50% done, or
        # 0.5, and we should mark half of the entire console as "done".
        done = int(index / total * max_width)
        # Whatever is left, should be printed as "unfinished"
        remaining = max_width - done
        # Print to the console.
        print(f'[{done * "#"}{remaining * "."}]', end='\r')
        # yield the element to work with it
        yield element
    # Finally, print the full line. If you wish, you can also print whitespace
    # so that the progress bar disappears once you are done. In that case do not
    # forget to add the "end" parameter to print function.
    print(f'[{max_width * "#"}]')


if __name__ == '__main__':
    list_of_elements = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j']
    for e in range_with_progress(list_of_elements):
        time.sleep(0.2)

Possible to change where Android Virtual Devices are saved?

there are major 4 steps 1. copy the .android folder to your desired location as i did in D:\Android\.android 2. set ANDROID_AVD_HOME in environment variables like ANDROID_AVD_HOME D:\Android\.android\avd 3. change avd name.ini file contents with new location like avd.ini.encoding=UTF-8 path=D:\Android\.android\avd\Pixel_2_API_29.avd path.rel=avd\Pixel_2_API_29.avd target=android-29 4. restart android studio

how to show lines in common (reverse diff)?

Was asked here before: Unix command to find lines common in two files

You could also try with perl (credit goes here)

perl -ne 'print if ($seen{$_} .= @ARGV) =~ /10$/'  file1 file2

Angular 2 ngfor first, last, index loop

Here is how its done in Angular 6

<li *ngFor="let user of userObservable ; first as isFirst">
   <span *ngIf="isFirst">default</span>
</li>

Note the change from let first = first to first as isFirst

Excel VBA Check if directory exists error

Use the FolderExists method of the Scripting object.

Public Function dirExists(s_directory As String) As Boolean
    Dim oFSO As Object
    Set oFSO = CreateObject("Scripting.FileSystemObject")
    dirExists = oFSO.FolderExists(s_directory)
End Function

Java how to replace 2 or more spaces with single space in string and delete leading and trailing spaces

You just need a:

replaceAll("\\s{2,}", " ").trim();

where you match one or more spaces and replace them with a single space and then trim whitespaces at the beginning and end (you could actually invert by first trimming and then matching to make the regex quicker as someone pointed out).

To test this out quickly try:

System.out.println(new String(" hello     there   ").trim().replaceAll("\\s{2,}", " "));

and it will return:

"hello there"

Java Initialize an int array in a constructor

The best way is not to write any initializing statements. This is because if you write int a[]=new int[3] then by default, in Java all the values of array i.e. a[0], a[1] and a[2] are initialized to 0! Regarding the local variable hiding a field, post your entire code for us to come to conclusion.

Test if string is URL encoded in PHP

I am using the following test to see if strings have been urlencoded:

if(urlencode($str) != str_replace(['%','+'], ['%25','%2B'], $str))

If a string has already been urlencoded, the only characters that will changed by double encoding are % (which starts all encoded character strings) and + (which replaces spaces.) Change them back and you should have the original string.

Let me know if this works for you.

Batch file to run a command in cmd within a directory

For me, the following is working and running activiti server as well as opening the explorer in browser (with the help of zb226's answer and comment);

START "runas /user:administrator" cmd /K "cd C:\activiti-5.9\setup & ant demo.start"

START /wait localhost:8080/activiti-explorer

Get specific line from text file using just shell script

Best performance method

sed '5q;d' file

Because sed stops reading any lines after the 5th one

Update experiment from Mr. Roger Dueck

I installed wcanadian-insane (6.6MB) and compared sed -n 1p /usr/share/dict/words and sed '1q;d' /usr/share/dict/words using the time command; the first took 0.043s, the second only 0.002s, so using 'q' is definitely a performance improvement!

How to hash a password

Use the below class to Generate a Salt first. Each user needs to have a different salt, we can save it in the database along with the other user properties. The rounds value decides the number of times the password will be hashed.

For more details: https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.rfc2898derivebytes.-ctor?view=netcore-3.1#System_Security_Cryptography_Rfc2898DeriveBytes__ctor_System_Byte___System_Byte___System_Int32_

public class HashSaltWithRounds
{
    int saltLength = 32;
    public byte[] GenerateSalt()
    {
        using (var randomNumberGenerator = new RNGCryptoServiceProvider())
        {
            var randomNumber = new byte[saltLength];
            randomNumberGenerator.GetBytes(randomNumber);
            return randomNumber;
        }
    }

    public string HashDataWithRounds(byte[] password, byte[] salt, int rounds)
    {
        using(var rfc2898= new Rfc2898DeriveBytes(password, salt, rounds))
        {
            return Convert.ToBase64String(rfc2898.GetBytes(32));
        }
    }
}

We can call it from a console application as follows. I have hashed the password twice using the same salt.

public class Program
{
    public static void Main(string[] args)
    {
        int numberOfIterations = 99;
        var hashFunction = new HashSaltWithRounds();

        string password = "Your Password Here";
        byte[] salt = hashFunction.GenerateSalt();

        var hashedPassword1 = hashFunction.HashDataWithRounds(Encoding.UTF8.GetBytes(password), salt, numberOfIterations);
        var hashedPassword2 = hashFunction.HashDataWithRounds(Encoding.UTF8.GetBytes(password), salt, numberOfIterations);

        Console.WriteLine($"hashedPassword1 :{hashedPassword1}");
        Console.WriteLine($"hashedPassword2 :{hashedPassword2}");
        Console.WriteLine(hashedPassword1.Equals(hashedPassword2));

        Console.ReadLine();

    }
}

Output

Get URL of ASP.Net Page in code-behind

If you want only the scheme and authority part of the request (protocol, host and port) use

Request.Url.GetLeftPart(UriPartial.Authority)

Java Web Service client basic authentication

If you use JAX-WS, the following works for me:

    //Get Web service Port
    WSTestService wsService = new WSTestService();
    WSTest wsPort = wsService.getWSTestPort();

    // Add username and password for Basic Authentication
    Map<String, Object> reqContext = ((BindingProvider) 
         wsPort).getRequestContext();
    reqContext.put(BindingProvider.USERNAME_PROPERTY, "username");
        reqContext.put(BindingProvider.PASSWORD_PROPERTY, "password");

How to create a custom attribute in C#

Utilizing/Copying Darin Dimitrov's great response, this is how to access a custom attribute on a property and not a class:

The decorated property [of class Foo]:

[MyCustomAttribute(SomeProperty = "This is a custom property")]
public string MyProperty { get; set; }

Fetching it:

PropertyInfo propertyInfo = typeof(Foo).GetProperty(propertyToCheck);
object[] attribute = propertyInfo.GetCustomAttributes(typeof(MyCustomAttribute), true);
if (attribute.Length > 0)
{
    MyCustomAttribute myAttribute = (MyCustomAttribute)attribute[0];
    string propertyValue = myAttribute.SomeProperty;
}

You can throw this in a loop and use reflection to access this custom attribute on each property of class Foo, as well:

foreach (PropertyInfo propertyInfo in Foo.GetType().GetProperties())
{
    string propertyName = propertyInfo.Name;

    object[] attribute = propertyInfo.GetCustomAttributes(typeof(MyCustomAttribute), true);
    // Just in case you have a property without this annotation
    if (attribute.Length > 0)
    {
        MyCustomAttribute myAttribute = (MyCustomAttribute)attribute[0];
        string propertyValue = myAttribute.SomeProperty;
        // TODO: whatever you need with this propertyValue
    }
}

Major thanks to you, Darin!!

Log4j2 configuration - No log4j2 configuration file found

Was following the documentations - Apache Log4j2 Configuratoin and Apache Log4j2 Maven in configuring log4j2 with yaml. As per the documentation, the following maven dependencies are required:

  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.8.1</version>
  </dependency>
  <dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.8.1</version>
  </dependency>

and

<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-yaml</artifactId>
    <version>2.8.6</version>
</dependency>

Just adding these didn't pick the configuration and always gave error. The way of debugging configuration by adding -Dorg.apache.logging.log4j.simplelog.StatusLogger.level=TRACE helped in seeing the logs. Later had to download the source using Maven and debugging helped in understanding the depended classes of log4j2. They are listed in org.apache.logging.log4j.core.config.yaml.YamlConfigurationFactory:

com.fasterxml.jackson.databind.ObjectMapper
com.fasterxml.jackson.databind.JsonNode
com.fasterxml.jackson.core.JsonParser
com.fasterxml.jackson.dataformat.yaml.YAMLFactory

Adding dependency mapping for jackson-dataformat-yaml will not have the first two classes. Hence, add the jackson-databind dependency to get yaml configuration working:

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.6</version>
</dependency>

You may add the version by referring to the Test Dependencies section of log4j-api version item from MVN Repository. E.g. for 2.8.1 version of log4j-api, refer this link and locate the jackson-databind version.

Moreover, you can use the below Java code to check if the classes are available in the classpath:

System.out.println(ClassLoader.getSystemResource("log4j2.yml")); //Check if file is available in CP
ClassLoader cl = Thread.currentThread().getContextClassLoader(); //Code as in log4j2 API. Version: 2.8.1
 String [] classes = {"com.fasterxml.jackson.databind.ObjectMapper",
 "com.fasterxml.jackson.databind.JsonNode",
 "com.fasterxml.jackson.core.JsonParser",
 "com.fasterxml.jackson.dataformat.yaml.YAMLFactory"};

 for(String className : classes) {
     cl.loadClass(className);
 }

How can I change the user on Git Bash?

For Mac Users

I am using Mac and I was facing the same problem while I was trying to push a project from Android Studio. The reason for that is another user had previously logged into GitHub and his credentials were saved in Keychain Access.

The solution is to delete all the information store in keychain for that process

enter image description here

A JOIN With Additional Conditions Using Query Builder or Eloquent

$results = DB::table('rooms')
                     ->distinct()
                     ->leftJoin('bookings', function($join)
                         {
                             $join->on('rooms.id', '=', 'bookings.room_type_id');
                             $join->on('arrival','>=',DB::raw("'2012-05-01'"));
                             $join->on('arrival','<=',DB::raw("'2012-05-10'"));
                             $join->on('departure','>=',DB::raw("'2012-05-01'"));
                             $join->on('departure','<=',DB::raw("'2012-05-10'"));
                         })
                     ->where('bookings.room_type_id', '=', NULL)
                     ->get();

Not quite sure if the between clause can be added to the join in laravel.

Notes:

  • DB::raw() instructs Laravel not to put back quotes.
  • By passing a closure to join methods you can add more join conditions to it, on() will add AND condition and orOn() will add OR condition.

How to split a large text file into smaller files with equal number of lines?

In case you just want to split by x number of lines each file, the given answers about split are OK. But, i am curious about no one paid attention to requirements:

  • "without having to count them" -> using wc + cut
  • "having the remainder in extra file" -> split does by default

I can't do that without "wc + cut", but I'm using that:

split -l  $(expr `wc $filename | cut -d ' ' -f3` / $chunks) $filename

This can be easily added to your bashrc functions so you can just invoke it passing filename and chunks:

 split -l  $(expr `wc $1 | cut -d ' ' -f3` / $2) $1

In case you want just x chunks without remainder in extra file, just adapt the formula to sum it (chunks - 1) on each file. I do use this approach because usually i just want x number of files rather than x lines per file:

split -l  $(expr `wc $1 | cut -d ' ' -f3` / $2 + `expr $2 - 1`) $1

You can add that to a script and call it your "ninja way", because if nothing suites your needs, you can build it :-)

How to set up Android emulator proxy settings

Install Proxifier in your host computer. Setup proxifier to use your proxy. You don't need to do anything else. You will be fine. Proxifier traps the calls from the system (including the android emulator) and route it through the configured proxy.

Fatal error: Call to undefined function sqlsrv_connect()

If you are using Microsoft Drivers 3.1, 3.0, and 2.0. Please check your PHP version already install with IIS.

Use this script to check the php version:

<?php echo phpinfo(); ?>

OR

If you have installed PHP Manager in IIS using web platform Installer you can check the version from it.

Then:
If you are using new PHP version (5.6) please download Drivers from here

For PHP version Lower than 5.6 - please download Drivers from here

  • PHP Driver version 3.1 requires PHP 5.4.32, or PHP 5.5.16, or later.
  • PHP Driver version 3.0 requires PHP 5.3.0 or later. If possible, use PHP 5.3.6, or later.
  • PHP Driver version 2.0 driver works with PHP 5.2.4 or later, but not with PHP 5.4. If possible, use PHP 5.2.13, or later.

Then use the PHP Manager to add that downloaded drivers into php config file.You can do it as shown below (browse the files and press OK). Then Restart the IIS Server

enter image description here

If this method not work please change the php version and try to run your php script. enter image description here

Tip:Change the php version to lower and try to understand what happened.then you can download relevant drivers.

Get the time difference between two datetimes

In ES8 using moment, now and start being moment objects.

const duration = moment.duration(now.diff(start));
const timespan = duration.get("hours").toString().padStart(2, '0') +":"+ duration.get("minutes").toString().padStart(2, '0') +":"+ duration.get("seconds").toString().padStart(2, '0');

Algorithm to compare two images

It is indeed much less simple than it seems :-) Nick's suggestion is a good one.

To get started, keep in mind that any worthwhile comparison method will essentially work by converting the images into a different form -- a form which makes it easier to pick similar features out. Usually, this stuff doesn't make for very light reading ...


One of the simplest examples I can think of is simply using the color space of each image. If two images have highly similar color distributions, then you can be reasonably sure that they show the same thing. At least, you can have enough certainty to flag it, or do more testing. Comparing images in color space will also resist things such as rotation, scaling, and some cropping. It won't, of course, resist heavy modification of the image or heavy recoloring (and even a simple hue shift will be somewhat tricky).

http://en.wikipedia.org/wiki/RGB_color_space
http://upvector.com/index.php?section=tutorials&subsection=tutorials/colorspace


Another example involves something called the Hough Transform. This transform essentially decomposes an image into a set of lines. You can then take some of the 'strongest' lines in each image and see if they line up. You can do some extra work to try and compensate for rotation and scaling too -- and in this case, since comparing a few lines is MUCH less computational work than doing the same to entire images -- it won't be so bad.

http://homepages.inf.ed.ac.uk/amos/hough.html
http://rkb.home.cern.ch/rkb/AN16pp/node122.html
http://en.wikipedia.org/wiki/Hough_transform

How can I download a file from a URL and save it in Rails?

An even shorter version:

require 'open-uri'
download = open('http://example.com/image.png')
IO.copy_stream(download, '~/image.png')

To keep the same filename:

IO.copy_stream(download, "~/#{download.base_uri.to_s.split('/')[-1]}")

Is there a good JSP editor for Eclipse?

As well as Amateras you could try Web Tools Project or Aptana. Although they will both give you way more than just a jsp editor.

Edit 2010/10/26 (comment from Simon Gibbs):

The Web Tools Project JSP editor is in the "Web Page Editor (Optional)" project.

Edit 2016/08/16 (extended comment from Dan Carter):

From Kepler (Eclipse 4.3.x) on, this is called "JSF Tools - Web Page Editor".

eclipse

How do I make the text box bigger in HTML/CSS?

there are many options that would change the height of an input box. padding, font-size, height would all do this. different combinations of these produce taller input boxes with different styles. I suggest just changing the font-size (and font-family for looks) and add some padding to make it even taller and also more appealing. I will give you an example of all three style though:

#signin input {
font-size:20px;
}

OR

#signin input {
padding:10px;
}

OR

#signin input {
height:24px;
}

This is the combination of the three that I recommend:

#signin input {
font-size:20px;font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif; font-weight: 300;
padding:10px;
}

How to hide the soft keyboard from inside a fragment?

This code works for fragments:

getActivity().getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

How to get my activity context?

you pass the context to class B in it's constructor, and make sure you pass getApplicationContext() instead of a activityContext()

What is PECS (Producer Extends Consumer Super)?

The principles behind this in computer science is called

  • Covariance: ? extends MyClass,
  • Contravariance: ? super MyClass and
  • Invariance/non-variance: MyClass

The picture below should explain the concept. Picture courtesy: Andrey Tyukin

Covariance vs Contravariance

Python setup.py develop vs install

Another thing that people may find useful when using the develop method is the --user option to install without sudo. Ex:

python setup.py develop --user

instead of

sudo python setup.py develop

How do I add BundleConfig.cs to my project?

BundleConfig is nothing more than bundle configuration moved to separate file. It used to be part of app startup code (filters, bundles, routes used to be configured in one class)

To add this file, first you need to add the Microsoft.AspNet.Web.Optimization nuget package to your web project:

Install-Package Microsoft.AspNet.Web.Optimization

Then under the App_Start folder create a new cs file called BundleConfig.cs. Here is what I have in my mine (ASP.NET MVC 5, but it should work with MVC 4):

using System.Web;
using System.Web.Optimization;

namespace CodeRepository.Web
{
    public class BundleConfig
    {
        // For more information on bundling, visit http://go.microsoft.com/fwlink/?LinkId=301862
        public static void RegisterBundles(BundleCollection bundles)
        {
            bundles.Add(new ScriptBundle("~/bundles/jquery").Include(
                        "~/Scripts/jquery-{version}.js"));

            bundles.Add(new ScriptBundle("~/bundles/jqueryval").Include(
                        "~/Scripts/jquery.validate*"));

            // Use the development version of Modernizr to develop with and learn from. Then, when you're
            // ready for production, use the build tool at http://modernizr.com to pick only the tests you need.
            bundles.Add(new ScriptBundle("~/bundles/modernizr").Include(
                        "~/Scripts/modernizr-*"));

            bundles.Add(new ScriptBundle("~/bundles/bootstrap").Include(
                      "~/Scripts/bootstrap.js",
                      "~/Scripts/respond.js"));

            bundles.Add(new StyleBundle("~/Content/css").Include(
                      "~/Content/bootstrap.css",
                      "~/Content/site.css"));
        }
    }
}

Then modify your Global.asax and add a call to RegisterBundles() in Application_Start():

using System.Web.Optimization;

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);
}

A closely related question: How to add reference to System.Web.Optimization for MVC-3-converted-to-4 app

Sql error on update : The UPDATE statement conflicted with the FOREIGN KEY constraint

In MySQL

set foreign_key_checks=0;

UPDATE patient INNER JOIN patient_address 
ON patient.id_no=patient_address.id_no 
SET patient.id_no='8008255601088', 
patient_address.id_no=patient.id_no 
WHERE patient.id_no='7008255601088';

Note that foreign_key_checks only temporarily set foreign key checking false. So it need to execute every time before update statement. We set it 0 as if we update parent first then that will not be allowed as child may have already that value. And if we update child first then that will also be not allowed as parent may not have that value from which we are updating. So we need to set foreign key check. Another thing is that if you are using command line tool to use this query then put care to mention spaces in place where i put new line or ENTER in code. As command line take it in one line, so it may happen that two words stick as patient_addressON which create syntax error.

Vagrant shared and synced folders

shared folders VS synced folders

Basically shared folders are renamed to synced folder from v1 to v2 (docs), under the bonnet it is still using vboxsf between host and guest (there is known performance issues if there are large numbers of files/directories).

Vagrantfile directory mounted as /vagrant in guest

Vagrant is mounting the current working directory (where Vagrantfile resides) as /vagrant in the guest, this is the default behaviour.

See docs

NOTE: By default, Vagrant will share your project directory (the directory with the Vagrantfile) to /vagrant.

You can disable this behaviour by adding cfg.vm.synced_folder ".", "/vagrant", disabled: true in your Vagrantfile.

Why synced folder is not working

Based on the output /tmp on host was NOT mounted during up time.

Use VAGRANT_INFO=debug vagrant up or VAGRANT_INFO=debug vagrant reload to start the VM for more output regarding why the synced folder is not mounted. Could be a permission issue (mode bits of /tmp on host should be drwxrwxrwt).

I did a test quick test using the following and it worked (I used opscode bento raring vagrant base box)

config.vm.synced_folder "/tmp", "/tmp/src"

output

$ vagrant reload
[default] Attempting graceful shutdown of VM...
[default] Setting the name of the VM...
[default] Clearing any previously set forwarded ports...
[default] Creating shared folders metadata...
[default] Clearing any previously set network interfaces...
[default] Available bridged network interfaces:
1) eth0
2) vmnet8
3) lxcbr0
4) vmnet1
What interface should the network bridge to? 1
[default] Preparing network interfaces based on configuration...
[default] Forwarding ports...
[default] -- 22 => 2222 (adapter 1)
[default] Running 'pre-boot' VM customizations...
[default] Booting VM...
[default] Waiting for VM to boot. This can take a few minutes.
[default] VM booted and ready for use!
[default] Configuring and enabling network interfaces...
[default] Mounting shared folders...
[default] -- /vagrant
[default] -- /tmp/src

Within the VM, you can see the mount info /tmp/src on /tmp/src type vboxsf (uid=900,gid=900,rw).

How do you get the cursor position in a textarea?

Here is code to get line number and column position

function getLineNumber(tArea) {

    return tArea.value.substr(0, tArea.selectionStart).split("\n").length;
}

function getCursorPos() {
    var me = $("textarea[name='documenttext']")[0];
    var el = $(me).get(0);
    var pos = 0;
    if ('selectionStart' in el) {
        pos = el.selectionStart;
    } else if ('selection' in document) {
        el.focus();
        var Sel = document.selection.createRange();
        var SelLength = document.selection.createRange().text.length;
        Sel.moveStart('character', -el.value.length);
        pos = Sel.text.length - SelLength;
    }
    var ret = pos - prevLine(me);
    alert(ret);

    return ret; 
}

function prevLine(me) {
    var lineArr = me.value.substr(0, me.selectionStart).split("\n");

    var numChars = 0;

    for (var i = 0; i < lineArr.length-1; i++) {
        numChars += lineArr[i].length+1;
    }

    return numChars;
}

tArea is the text area DOM element

How to see an HTML page on Github as a normal rendered HTML page to see preview in browser, without downloading?

I have found another way:

  1. Click on the "Raw" button if you haven't already
  2. Ctrl+A, Ctrl+C
  3. Open "Developer Tools" with F12
  4. In the "Inspector" right-click on the tag and choose "Edit HTML"
  5. Ctrl+A, Ctrl+V
  6. Ctr+Return

Tested on Firefox but it should work in other browsers too

SSL received a record that exceeded the maximum permissible length. (Error code: ssl_error_rx_record_too_long)

Finally find out the problem:
the port 443 was listening on HTTP instead of HTTPS, changed to HTTPS solved my issue.

Python 3 string.join() equivalent?

There are method join for string objects:

".".join(("a","b","c"))

How do you change the datatype of a column in SQL Server?

The syntax to modify a column in an existing table in SQL Server (Transact-SQL) is:

ALTER TABLE table_name
    ALTER COLUMN column_name column_type;

For example:

ALTER TABLE employees
    ALTER COLUMN last_name VARCHAR(75) NOT NULL;

This SQL Server ALTER TABLE example will modify the column called last_name to be a data type of VARCHAR(75) and force the column to not allow null values.

see here

How to write trycatch in R

Since I just lost two days of my life trying to solve for tryCatch for an irr function, I thought I should share my wisdom (and what is missing). FYI - irr is an actual function from FinCal in this case where got errors in a few cases on a large data set.

  1. Set up tryCatch as part of a function. For example:

    irr2 <- function (x) {
      out <- tryCatch(irr(x), error = function(e) NULL)
      return(out)
    }
    
  2. For the error (or warning) to work, you actually need to create a function. I originally for error part just wrote error = return(NULL) and ALL values came back null.

  3. Remember to create a sub-output (like my "out") and to return(out).

How do I install a plugin for vim?

Those two commands will create a ~/.vim/vim-haml/ directory with the ftplugin, syntax, etc directories in it. Those directories need to be immediately in the ~/.vim directory proper or ~/.vim/vim-haml needs to be added to the list of paths that vim searches for plugins.

Edit:

I recently decided to tweak my vim config and in the process wound up writing the following rakefile. It only works on Mac/Linux, but the advantage over cp versions is that it's completely safe (symlinks don't overwrite existing files, uninstall only deletes symlinks) and easy to keep things updated.

# Easily install vim plugins from a source control checkout (e.g. Github)
#
# alias vim-install=rake -f ~/.vim/rakefile-vim-install
# vim-install
# vim-install uninstall

require 'ftools'
require 'fileutils'

task :default => :install
desc "Install a vim plugin the lazy way"
task :install do
  vim_dir      = File.expand_path("~/.vim")
  plugin_dir   = Dir.pwd

  if not (FileTest.exists? File.join(plugin_dir,".git") or
          FileTest.exists? File.join(plugin_dir,".svn") or
          FileTest.exists? File.join(plugin_dir,".hg"))
      puts "#{plugin_dir} isn't a source controlled directory. Aborting."
      exit 1
  end

  Dir['**/'].each do |d|
    FileUtils.mkdir_p File.join(vim_dir, d)
  end

  Dir["**/*.{txt,snippet,snippets,vim,js,wsf}"].each do |f|
    ln File.join(plugin_dir, f), File.join(vim_dir,f)
  end

  boldred = "\033[1;31m"
  clear = "\033[0m"
  puts "\nDone. Remember to #{boldred}:helptags ~/.vim/doc#{clear}"
end

task :uninstall do
  vim_dir      = File.expand_path("~/.vim")
  plugin_dir   = Dir.pwd
  Dir["**/*.{txt,snippet,snippets,vim}"].each do |f|
    safe_rm File.join(vim_dir, f)
  end
end

def nicename(path)
    boldgreen = "\033[1;32m"
    clear = "\033[0m"
    return "#{boldgreen}#{File.join(path.split('/')[-2..-1])}#{clear}\t"
end

def ln(src, dst)
    begin
        FileUtils.ln_s src, dst
        puts "    Symlink #{nicename src}\t => #{nicename dst}"
    rescue Errno::EEXIST
        puts "  #{nicename dst} exists! Skipping."
    end
end

def cp(src, dst)
  puts "    Copying #{nicename src}\t=> #{nicename dst}"
  FileUtils.cp src, dst
end

def safe_rm(target)
    if FileTest.exists? target and FileTest.symlink? target
        puts "    #{nicename target} removed."
        File.delete target
    else
        puts "  #{nicename target} is not a symlink. Skipping"
    end
end

Android - Handle "Enter" in an EditText

I know this is a year old, but I just discovered this works perfectly for an EditText.

EditText textin = (EditText) findViewById(R.id.editText1);
textin.setInputType(InputType.TYPE_CLASS_TEXT);

It prevents anything but text and space. I could not tab, "return" ("\n"), or anything.

Contains case insensitive

Use a RegExp:

if (!/ral/i.test(referrer)) {
    ...
}

Or, use .toLowerCase():

if (referrer.toLowerCase().indexOf("ral") == -1)

How do I clone a generic List in Java?

ArrayList newArrayList = (ArrayList) oldArrayList.clone();

How to search file text for a pattern and replace it with a given value

This works for me:

filename = "foo"
text = File.read(filename) 
content = text.gsub(/search_regexp/, "replacestring")
File.open(filename, "w") { |file| file << content }

Problems using Maven and SSL behind proxy

It happens because your maven plugin try to connect to an HTTPS remote repository (https://repo.maven.apache.org/maven2) or (https://repo1.maven.apache.org).

Some time ago, you could to change these URL's to use HTTP instead use HTTPS, but since January 15th 2020, these URL's doesn't work any more, only the HTTPS URL's.

As an easy way to fix this problem, you can use the insecure Maven URL in the settings.xml file. So, you need to change ALL of yours references above mencioned to: http://insecure.repo1.maven.org/maven2/

TIP: Your JAVA_HOME variable always needs to point to your JDK path, not to your JRE path, for example: "C:\Program Files\Java\jdk1.7.0_80".

"unable to locate adb" using Android Studio

I had the same problem, and I solved it by doing:

  • (You should be connected to the internet)
  • click the logo of the SDK Manager
  • click Launch StandAlone SDK Manager (wait a moment)
  • if the dialog of the SDK manager shows, you click cexbox [Tools] and Install all packages
  • if the download is finished, you restart android studio and boot again..

After that, it should work.

Can't find SDK folder inside Android studio path, and SDK manager not opening

When you install the android studio just by downloading from https://developer.android.com/studio/install.html sometimes sdk folder will not get appear in C:\Users\home\AppData\Local\Android Location.. But to set the android studio we need to set the path for android on this location. So simply 1) start the android setup.
2) follow the instruction and android studio will automatically download the sdk folder by itself. (it will show the window like "Downloading Components"). After completing that installation check the above path again. sdk folder will get appear now.

Change image size via parent div

Yours:

  <div style="height:42px;width:42px">
  <img src="http://someimage.jpg">

Is it okay to use this code?

  <div class= "box">
  <img src= "http://someimage.jpg" class= "img">
  </div>

  <style type="text/css">
  .box{width: 42; height: 42;}
  .img{width: 20; height:20;}
  </style>

Just trying, though late. :3 For someone else reading this, letme know if the way i wrote the code were not good. im new in this kind of language. and i still want to learn more.

How can I disable the Maven Javadoc plugin from the command line?

It seems, that the simple way

-Dmaven.javadoc.skip=true

does not work with the release-plugin. in this case you have to pass the parameter as an "argument"

mvn release:perform -Darguments="-Dmaven.javadoc.skip=true"

How can I define fieldset border color?

I added it for all fieldsets with

fieldset {
        border: 1px solid lightgray;
    }

I didnt work if I set it separately using for example

border-color : red

. Then a black line was drawn next to the red line.

Convert string to symbol-able in ruby

In Rails you can do this using underscore method:

"Book Author Title".delete(' ').underscore.to_sym
=> :book_author_title

The simpler code is using regex (works with Ruby):

"Book Author Title".downcase.gsub(/\s+/, "_").to_sym
=> :book_author_title

CSS background image in :after element

A couple things

(a) you cant have both background-color and background, background will always win. in the example below, i combined them through shorthand, but this will produce the color only as a fallback method when the image does not show.

(b) no-scroll does not work, i don't believe it is a valid property of a background-image. try something like fixed:

.button:after {
    content: "";
    width: 30px;
    height: 30px;
    background:red url("http://www.gentleface.com/i/free_toolbar_icons_16x16_black.png") no-repeat -30px -50px fixed;
    top: 10px;
    right: 5px;
    position: absolute;
    display: inline-block;
}

I updated your jsFiddle to this and it showed the image.

Replace all occurrences of a String using StringBuilder?

Look at JavaDoc of replaceAll method of String class:

Replaces each substring of this string that matches the given regular expression with the given replacement. An invocation of this method of the form str.replaceAll(regex, repl) yields exactly the same result as the expression

java.util.regex.Pattern.compile(regex).matcher(str).replaceAll(repl)

As you can see you can use Pattern and Matcher to do that.

Spring 3 MVC resources and tag <mvc:resources />

This worked for me

In JSP, to view the image

<img src="${pageContext.request.contextPath}/resources/images/slide-are.jpg">

In dispatcher-servlet.xml

<mvc:annotation-driven />
<mvc:resources mapping="/resources/**" location="/WEB-INF/resources/" />

How to open some ports on Ubuntu?

Ubuntu these days comes with ufw - Uncomplicated Firewall. ufw is an easy-to-use method of handling iptables rules.

Try using this command to allow a port

sudo ufw allow 1701

To test connectivity, you could try shutting down the VPN software (freeing up the ports) and using netcat to listen, like this:

nc -l 1701

Then use telnet from your Windows host and see what shows up on your Ubuntu terminal. This can be repeated for each port you'd like to test.

Vertical divider CSS

<div class="headerdivider"></div>

and

.headerdivider {
    border-left: 1px solid #38546d;
    background: #16222c;
    width: 1px;
    height: 80px;
    position: absolute;
    right: 250px;
    top: 10px;
}

How to group pandas DataFrame entries by date in a non-unique column

ecatmur's solution will work fine. This will be better performance on large datasets, though:

data.groupby(data['date'].map(lambda x: x.year))

How does += (plus equal) work?

...and don't forget what happens when you mix types:

x = 127;
x += " hours "
// x is now a string: "127 hours "
x += 1 === 0;
// x is still a string: "127 hours false"

Show only two digit after decimal

First thing that should pop in a developer head while formatting a number into char sequence should be care of such details like do it will be possible to reverse the operation.

And other aspect is providing proper result. So you want to truncate the number or round it.

So before you start you should ask your self, am i interested on the value or not.

To achieve your goal you have multiple options but most of them refer to Format and Formatter, but i just suggest to look in this answer.

'gulp' is not recognized as an internal or external command

Go to My Computer>Properties>Advance System Settings>Environment Variables>

Under the variables of Administrator edit the PATH variable & change its value to "C:\Users\Username\AppData\Roaming\npm". Note: The username in the path will be the current Admin user's name that you have logged in with.

What's the best way to get the last element of an array without deleting it?

One way to avoid pass-by-reference errors (eg. "end(array_values($foo))") is to use call_user_func or call_user_func_array:

// PHP Fatal error: Only variables can be passed by reference
// No output (500 server error)
var_dump(end(array(1, 2, 3)));

// No errors, but modifies the array's internal pointer
// Outputs "int(3)"
var_dump(call_user_func('end', array(1, 2, 3)));

// PHP Strict standards:  Only variables should be passed by reference
// Outputs "int(3)"
var_dump(end(array_values(array(1, 2, 3))));

// No errors, doesn't change the array
// Outputs "int(3)"
var_dump(call_user_func('end', array_values(array(1, 2, 3))));

Oracle date format picture ends before converting entire input string

Perhaps you should check NLS_DATE_FORMAT and use the date string conforming the format. Or you can use to_date function within the INSERT statement, like the following:

insert into visit
values(123456, 
       to_date('19-JUN-13', 'dd-mon-yy'),
       to_date('13-AUG-13 12:56 A.M.', 'dd-mon-yyyy hh:mi A.M.'));

Additionally, Oracle DATE stores date and time information together.

EditText, inputType values (xml)

Supplemental answer

Here is how the standard keyboard behaves for each of these input types.

enter image description here

See this answer for more details.

Spark dataframe: collect () vs select ()

Short answer in bolds:

  • collect is mainly to serialize
    (loss of parallelism preserving all other data characteristics of the dataframe)
    For example with a PrintWriter pw you can't do direct df.foreach( r => pw.write(r) ), must to use collect before foreach, df.collect.foreach(etc).
    PS: the "loss of parallelism" is not a "total loss" because after serialization it can be distributed again to executors.

  • select is mainly to select columns, similar to projection in relational algebra
    (only similar in framework's context because Spark select not deduplicate data).
    So, it is also a complement of filter in the framework's context.


Commenting explanations of other answers: I like the Jeff's classification of Spark operations in transformations (as select) and actions (as collect). It is also good remember that transforms (including select) are lazily evaluated.

What does a lazy val do?

Also lazy is useful without cyclic dependencies, as in the following code:

abstract class X {
  val x: String
  println ("x is "+x.length)
}

object Y extends X { val x = "Hello" }
Y

Accessing Y will now throw null pointer exception, because x is not yet initialized. The following, however, works fine:

abstract class X {
  val x: String
  println ("x is "+x.length)
}

object Y extends X { lazy val x = "Hello" }
Y

EDIT: the following will also work:

object Y extends { val x = "Hello" } with X 

This is called an "early initializer". See this SO question for more details.

Rounding SQL DateTime to midnight

--
-- SQL DATEDIFF getting midnight time parts 
--
SELECT GETDATE() AS Now, 
   Convert(DateTime, DATEDIFF(DAY, 0, GETDATE())) AS MidnightToday,
   Convert(DateTime, DATEDIFF(DAY, -1, GETDATE())) AS MidnightNextDay,
   Convert(DateTime, DATEDIFF(DAY, 1, GETDATE())) AS MidnightYesterDay
go
Now                   MidnightToday          MidnightNextDay        MidnightYesterDay     
 --------------------  ---------------------  ---------------------  --------------------- 
 8/27/2014 4:30:22 PM  8/27/2014 12:00:00 AM  8/28/2014 12:00:00 AM  8/26/2014 12:00:00 AM 

Git: force user and password prompt

This is most likely because you have multiple accounts, like one private, one for work with GitHub.

SOLUTION On Windows, go to Start > Credential Manager > Windows Credentials and remove GitHub creds, then try pulling or pushing again and you will be prompted to relogin into GitHub

SOLUTION OnMac, issue following on terminal:

git remote set-url origin https://[email protected]/username/repo-name.git

by replacing 'username' with your GitHub username in both places and providing your GitHub repo name.

Script to kill all connections to a database (More than RESTRICTED_USER ROLLBACK)

Updated

For MS SQL Server 2012 and above

USE [master];

DECLARE @kill varchar(8000) = '';  
SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), session_id) + ';'  
FROM sys.dm_exec_sessions
WHERE database_id  = db_id('MyDB')

EXEC(@kill);

For MS SQL Server 2000, 2005, 2008

USE master;

DECLARE @kill varchar(8000); SET @kill = '';  
SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), spid) + ';'  
FROM master..sysprocesses  
WHERE dbid = db_id('MyDB')

EXEC(@kill); 

The matching wildcard is strict, but no declaration can be found for element 'tx:annotation-driven'

For me the thing that worked was the order in which the namespaces were defined in the xsi:schemaLocation tag : [ since the version was all good and also it was transaction-manager already ]

The error was with :

 http://www.springframework.org/schema/mvc
 http://www.springframework.org/schema/tx
 http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
 http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"

AND RESOLVED WITH :

http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"

$(document).on('click', '#id', function() {}) vs $('#id').on('click', function(){})

The first example demonstrates event delegation. The event handler is bound to an element higher up the DOM tree (in this case, the document) and will be executed when an event reaches that element having originated on an element matching the selector.

This is possible because most DOM events bubble up the tree from the point of origin. If you click on the #id element, a click event is generated that will bubble up through all of the ancestor elements (side note: there is actually a phase before this, called the 'capture phase', when the event comes down the tree to the target). You can capture the event on any of those ancestors.

The second example binds the event handler directly to the element. The event will still bubble (unless you prevent that in the handler) but since the handler is bound to the target, you won't see the effects of this process.

By delegating an event handler, you can ensure it is executed for elements that did not exist in the DOM at the time of binding. If your #id element was created after your second example, your handler would never execute. By binding to an element that you know is definitely in the DOM at the time of execution, you ensure that your handler will actually be attached to something and can be executed as appropriate later on.

How can I write these variables into one line of code in C#?

Give this a go:

string format = "{0} / {1} / {2} {3}";
string date = string.Format(format,mon.ToString(),da.ToString(),yer.ToString();
Console.WriteLine(date);

In fact, there's probably a way to format it automatically without even doing it yourself.

Check out http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

How to convert/parse from String to char in java?

If your string contains exactly one character the simplest way to convert it to a character is probably to call the charAt method:

char c = s.charAt(0);

Bootstrap 3 collapsed menu doesn't close on click

Simple Try to make a function in javascript for dropdown collapse class.

Example:

JS:

$scope.toogleMyClass  = function(){

    //dropdown-element

    $timeout(function(){
        $scope.preLoader = false;
        $(document).ready(function() {
            $("#dropdown-element").toggleClass('show');
        });
    },100);

};

Hook this function to onClick simple works for me.

Directly assigning values to C Pointers

In the first example, ptr has not been initialized, so it points to an unspecified memory location. When you assign something to this unspecified location, your program blows up.

In the second example, the address is set when you say ptr = &q, so you're OK.

How create a new deep copy (clone) of a List<T>?

List<Book> books_2 = new List<Book>(books_2.ToArray());

That should do exactly what you want. Demonstrated here.

Capturing a form submit with jquery and .submit

Just a tip: Remember to put the code detection on document.ready, otherwise it might not work. That was my case.

How do I make XAML DataGridColumns fill the entire DataGrid?

I added a HorizontalAlignment="Center" (The default is "Strech") and it solved my problem because it made the datagrid only as wide as needed. (Removed the datagrid's Width setting if you have one.)

enter image description here

How do I install chkconfig on Ubuntu?

Chkconfig is no longer available in Ubuntu.

Chkconfig is a script. You can download it from here.

Very simple C# CSV reader

This is what I used in a project, parses a single line of data.

    private string[] csvParser(string csv, char separator = ',')
    {
        List <string> = new <string>();
        string[] temp = csv.Split(separator);
        int counter = 0;
        string data = string.Empty;
        while (counter < temp.Length)
        {
            data = temp[counter].Trim();
            if (data.Trim().StartsWith("\""))
            {
                bool isLast = false;
                while (!isLast && counter < temp.Length)
                {
                    data += separator.ToString() + temp[counter + 1];
                    counter++;
                    isLast = (temp[counter].Trim().EndsWith("\""));
                }
            }
            parsed.Add(data);
            counter++;
        }

        return parsed.ToArray();

    }

http://zamirsblog.blogspot.com/2013/09/c-csv-parser-csvparser.html

Checking if a double (or float) is NaN in C++

You can use the isnan() function, but you need to include the C math library.

#include <cmath>

As this function is part of C99, it is not available everywhere. If your vendor does not supply the function, you can also define your own variant for compatibility.

inline bool isnan(double x) {
    return x != x;
}

set default schema for a sql query

I do not believe there is a "per query" way to do this. (You can use the use keyword to specify the database - not the schema - but that's technically a separate query as you have to issue the go command afterward.)

Remember, in SQL server fully qualified table names are in the format:

[database].[schema].[table]

In SQL Server Management Studio you can configure all the defaults you're asking about.

  • You can set up the default database on a per-user basis (or in your connection string):

    Security > Logins > (right click) user > Properties > General

  • You can set up the default schema on a per-user basis (but I do not believe you can configure it in your connection string, although if you use dbo that is always the default):

    Security > Logins > (right click) user > Properties > User Mapping > Default Schema

In short, if you use dbo for your schema, you'll likely have the least amount of headaches.

PHP CURL Enable Linux

add this line end of php.ini

openssl.cafile=/opt/lampp/share/curl/curl-ca-bundle.crt

may be curl path cannot be identified by PHP

Minimum rights required to run a windows service as a domain account

I do know that the account needs to have "Log on as a Service" privileges. Other than that, I'm not sure. A quick reference to Log on as a Service can be found here, and there is a lot of information of specific privileges here.

Sorting dropdown alphabetically in AngularJS

For anyone who wants to sort the variable in third layer:

<select ng-option="friend.pet.name for friend in friends"></select>

you can do it like this

<select ng-option="friend.pet.name for friend in friends | orderBy: 'pet.name'"></select>

Initialize 2D array

You can use for loop if you really want to.

char table[][] table = new char[row][col];
for(int i = 0; i < row * col ; ++i){
     table[i/row][i % col] = char('a' + (i+1));
}

or do what bhesh said.

How do I determine scrollHeight?

Correct ways in jQuery are -

  • $('#test').prop('scrollHeight') OR
  • $('#test')[0].scrollHeight OR
  • $('#test').get(0).scrollHeight

Trying to read cell 1,1 in spreadsheet using Google Script API

You have to first obtain the Range object. Also, getCell() will not return the value of the cell but instead will return a Range object of the cell. So, use something on the lines of

function email() {

// Opens SS by its ID

var ss = SpreadsheetApp.openById("0AgJjDgtUl5KddE5rR01NSFcxYTRnUHBCQ0stTXNMenc");

// Get the name of this SS

var name = ss.getName();  // Not necessary 

// Read cell 1,1 * Line below does't work *

// var data = Range.getCell(0, 0);
var sheet = ss.getSheetByName('Sheet1'); // or whatever is the name of the sheet 
var range = sheet.getRange(1,1); 
var data = range.getValue();

}

The hierarchy is Spreadsheet --> Sheet --> Range --> Cell.

Creating NSData from NSString in Swift

// Checking the format
var urlString: NSString = NSString(data: jsonData, encoding: NSUTF8StringEncoding)

// Convert your data and set your request's HTTPBody property
var stringData: NSString = NSString(string: "jsonRequest=\(urlString)")

var requestBodyData: NSData = stringData.dataUsingEncoding(NSUTF8StringEncoding)!

How to check if internet connection is present in Java?

InetAddress.isReachable sometime return false if internet connection exist.

An alternative method to check internet availability in java is : This function make a real ICMP ECHO ping.

public static boolean isReachableByPing(String host) {
     try{
                String cmd = "";
                if(System.getProperty("os.name").startsWith("Windows")) {   
                        // For Windows
                        cmd = "ping -n 1 " + host;
                } else {
                        // For Linux and OSX
                        cmd = "ping -c 1 " + host;
                }

                Process myProcess = Runtime.getRuntime().exec(cmd);
                myProcess.waitFor();

                if(myProcess.exitValue() == 0) {

                        return true;
                } else {

                        return false;
                }

        } catch( Exception e ) {

                e.printStackTrace();
                return false;
        }
}

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock'

Encountered a similar problem after upgrading to Catalina OS. After running mysqld command, I found that there was some issue with the logs file. It could be different for others.

$ mysqld

Issue was

2019-10-16T04:58:59.174474Z 0 [ERROR] Could not open file '/var/log/mysql/error.log' for error logging: No such file or directory
2019-10-16T04:58:59.174508Z 0 [ERROR] Aborting

Resolved it by creating it and applying proper permissions.

sudo mkdir -p /var/log/mysql
sudo touch /var/log/mysql/error.log
sudo chown -R _mysql:mysql /var/log/mysql/

Restart MySQL

brew services restart [email protected]

Issue was resolved.

mysql -uroot -proot

How to delete a file from SD card?

Sorry: There is a mistake in my code before because of the site validation.

String myFile = "/Name Folder/File.jpg";  

String myPath = Environment.getExternalStorageDirectory()+myFile;  

File f = new File(myPath);
Boolean deleted = f.delete();

I think is clear... First you must to know your file location. Second,,, Environment.getExternalStorageDirectory() is a method who gets your app directory. Lastly the class File who handle your file...

How do I add a library path in cmake?

The simplest way of doing this would be to add

include_directories(${CMAKE_SOURCE_DIR}/inc)
link_directories(${CMAKE_SOURCE_DIR}/lib)

add_executable(foo ${FOO_SRCS})
target_link_libraries(foo bar) # libbar.so is found in ${CMAKE_SOURCE_DIR}/lib

The modern CMake version that doesn't add the -I and -L flags to every compiler invocation would be to use imported libraries:

add_library(bar SHARED IMPORTED) # or STATIC instead of SHARED
set_target_properties(bar PROPERTIES
  IMPORTED_LOCATION "${CMAKE_SOURCE_DIR}/lib/libbar.so"
  INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_SOURCE_DIR}/include/libbar"
)

set(FOO_SRCS "foo.cpp")
add_executable(foo ${FOO_SRCS})
target_link_libraries(foo bar) # also adds the required include path

If setting the INTERFACE_INCLUDE_DIRECTORIES doesn't add the path, older versions of CMake also allow you to use target_include_directories(bar PUBLIC /path/to/include). However, this no longer works with CMake 3.6 or newer.

PHP new line break in emails

Are you building this string using single or double quotes? \r and \n only work with double quotes, as well as embedded variables. For example:

$foo = 'bar';
echo 'Hello \n $foo!';

will output:

Hello \n $foo!

But:

$foo = 'bar';
echo "Hello \n $foo!";

will output:

Hello
bar!

How do I integrate Ajax with Django applications?

AJAX is the best way to do asynchronous tasks. Making asynchronous calls is something common in use in any website building. We will take a short example to learn how we can implement AJAX in Django. We need to use jQuery so as to write less javascript.

This is Contact example, which is the simplest example, I am using to explain the basics of AJAX and its implementation in Django. We will be making POST request in this example. I am following one of the example of this post: https://djangopy.org/learn/step-up-guide-to-implement-ajax-in-django

models.py

Let's first create the model of Contact, having basic details.

from django.db import models

class Contact(models.Model):
    name = models.CharField(max_length = 100)
    email = models.EmailField()
    message = models.TextField()
    timestamp = models.DateTimeField(auto_now_add = True)

    def __str__(self):
        return self.name

forms.py

Create the form for the above model.

from django import forms
from .models import Contact

class ContactForm(forms.ModelForm):
    class Meta:
        model = Contact
        exclude = ["timestamp", ]

views.py

The views look similar to the basic function-based create view, but instead of returning with render, we are using JsonResponse response.

from django.http import JsonResponse
from .forms import ContactForm

def postContact(request):
    if request.method == "POST" and request.is_ajax():
        form = ContactForm(request.POST)
        form.save()
        return JsonResponse({"success":True}, status=200)
    return JsonResponse({"success":False}, status=400)

urls.py

Let's create the route of the above view.

from django.contrib import admin
from django.urls import path
from app_1 import views as app1

urlpatterns = [
    path('ajax/contact', app1.postContact, name ='contact_submit'),
]

template

Moving to frontend section, render the form which was created above enclosing form tag along with csrf_token and submit button. Note that we have included the jquery library.

<form id = "contactForm" method= "POST">{% csrf_token %}
   {{ contactForm.as_p }}
  <input type="submit" name="contact-submit" class="btn btn-primary" />
</form>

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

Javascript

Let's now talk about javascript part, on the form submit we are making ajax request of type POST, taking the form data and sending to the server side.

$("#contactForm").submit(function(e){
    // prevent from normal form behaviour
        e.preventDefault();
        // serialize the form data  
        var serializedData = $(this).serialize();
        $.ajax({
            type : 'POST',
            url :  "{% url 'contact_submit' %}",
            data : serializedData,
            success : function(response){
            //reset the form after successful submit
                $("#contactForm")[0].reset(); 
            },
            error : function(response){
                console.log(response)
            }
        });
   });

This is just a basic example to get started with AJAX with django, if you want to get dive with several more examples, you can go through this article: https://djangopy.org/learn/step-up-guide-to-implement-ajax-in-django

Should I use "camel case" or underscores in python?

PEP 8 advises the first form for readability. You can find it here.

Function names should be lowercase, with words separated by underscores as necessary to improve readability.

How to print out more than 20 items (documents) in MongoDB's shell?

Could always do:

db.foo.find().forEach(function(f){print(tojson(f, '', true));});

To get that compact view.

Also, I find it very useful to limit the fields returned by the find so:

db.foo.find({},{name:1}).forEach(function(f){print(tojson(f, '', true));});

which would return only the _id and name field from foo.

Properly escape a double quote in CSV

Not only double quotes, you will be in need for single quote ('), double quote ("), backslash (\) and NUL (the NULL byte).

Use fputcsv() to write, and fgetcsv() to read, which will take care of all.

Detect if PHP session exists

Which method is used to check if SESSION exists or not? Answer:

isset($_SESSION['variable_name'])

Example:

isset($_SESSION['id'])

Forgot Oracle username and password, how to retrieve?

The usernames are shown in the dba_users's username column, there is a script you can run called:

alter user username identified by password

You can get more information here - https://community.oracle.com/thread/632617?tstart=0

How to merge two PDF files into one in Java?

package article14;

import java.io.File;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.util.PDFMergerUtility;

public class Pdf
{
    public static void main(String args[])
    {
        new Pdf().createNew();
        new Pdf().combine();
        }

    public void combine()
    {
        try
        {
        PDFMergerUtility mergePdf = new PDFMergerUtility();
        String folder ="pdf";
        File _folder = new File(folder);
        File[] filesInFolder;
        filesInFolder = _folder.listFiles();
        for (File string : filesInFolder)
        {
            mergePdf.addSource(string);    
        }
    mergePdf.setDestinationFileName("Combined.pdf");
    mergePdf.mergeDocuments();
        }
        catch(Exception e)
        {

        }  
    }

public void createNew()
{
    PDDocument document = null;
    try
    {
        String filename="test.pdf";
        document=new PDDocument();
        PDPage blankPage = new PDPage();
        document.addPage( blankPage );
        document.save( filename );
    }
    catch(Exception e)
    {

    }
}

}

Breaking up long strings on multiple lines in Ruby without stripping newlines

I had this problem when I try to write a very long url, the following works.

image_url = %w(
    http://minio.127.0.0.1.xip.io:9000/
    bucket29/docs/b7cfab0e-0119-452c-b262-1b78e3fccf38/
    28ed3774-b234-4de2-9a11-7d657707f79c?
    X-Amz-Algorithm=AWS4-HMAC-SHA256&
    X-Amz-Credential=ABABABABABABABABA
    %2Fus-east-1%2Fs3%2Faws4_request&
    X-Amz-Date=20170702T000940Z&
    X-Amz-Expires=3600&X-Amz-SignedHeaders=host&
    X-Amz-Signature=ABABABABABABABABABABAB
    ABABABABABABABABABABABABABABABABABABA
).join

Note, there must not be any newlines, white spaces when the url string is formed. If you want newlines, then use HEREDOC.

Here you have indentation for readability, ease of modification, without the fiddly quotes and backslashes on every line. The cost of joining the strings should be negligible.

X-Frame-Options Allow-From multiple domains

How about an approach that not only allows multiple domains, but allows dynamic domains.

The use case here is with a Sharepoint app part which loads our site inside of Sharepoint via an iframe. The problem is that sharepoint has dynamic subdomains such as https://yoursite.sharepoint.com. So for IE, we need to specify ALLOW-FROM https://.sharepoint.com

Tricky business, but we can get it done knowing two facts:

  1. When an iframe loads, it only validates the X-Frame-Options on the first request. Once the iframe is loaded, you can navigate within the iframe and the header isn't checked on subsequent requests.

  2. Also, when an iframe is loaded, the HTTP referer is the parent iframe url.

You can leverage these two facts server side. In ruby, I'm using the following code:

  uri = URI.parse(request.referer)
  if uri.host.match(/\.sharepoint\.com$/)
    url = "https://#{uri.host}"
    response.headers['X-Frame-Options'] = "ALLOW-FROM #{url}"
  end

Here we can dynamically allow domains based upon the parent domain. In this case, we ensure that the host ends in sharepoint.com keeping our site safe from clickjacking.

I'd love to hear feedback on this approach.

How to SSH into Docker?

Firstly you need to install a SSH server in the images you wish to ssh-into. You can use a base image for all your container with the ssh server installed. Then you only have to run each container mapping the ssh port (default 22) to one to the host's ports (Remote Server in your image), using -p <hostPort>:<containerPort>. i.e:

docker run -p 52022:22 container1 
docker run -p 53022:22 container2

Then, if ports 52022 and 53022 of host's are accessible from outside, you can directly ssh to the containers using the ip of the host (Remote Server) specifying the port in ssh with -p <port>. I.e.:

ssh -p 52022 myuser@RemoteServer --> SSH to container1

ssh -p 53022 myuser@RemoteServer --> SSH to container2

Changing font size and direction of axes text in ggplot2

Using "fill" attribute helps in cases like this. You can remove the text from axis using element_blank()and show multi color bar chart with a legend. I am plotting a part removal frequency in a repair shop as below

ggplot(data=df_subset,aes(x=Part,y=Removal_Frequency,fill=Part))+geom_bar(stat="identity")+theme(axis.text.x  = element_blank())

I went for this solution in my case as I had many bars in bar chart and I was not able to find a suitable font size which is both readable and also small enough not to overlap each other.

ALTER DATABASE failed because a lock could not be placed on database

In SQL Management Studio, go to Security -> Logins and double click your Login. Choose Server Roles from the left column, and verify that sysadmin is checked.

In my case, I was logged in on an account without that privilege.

HTH!

How to create a HTML Table from a PHP array?

It would be better to just fetch the data into array like this:

<?php
$shop = array( array("title"=>"rose", "price"=>1.25 , "number"=>15),
               array("title"=>"daisy", "price"=>0.75 , "number"=>25),
               array("title"=>"orchid", "price"=>1.15 , "number"=>7) 
             ); 
?>

And then do something like this, which should work well even when you add more columns to your table in the database later.

<?php if (count($shop) > 0): ?>
<table>
  <thead>
    <tr>
      <th><?php echo implode('</th><th>', array_keys(current($shop))); ?></th>
    </tr>
  </thead>
  <tbody>
<?php foreach ($shop as $row): array_map('htmlentities', $row); ?>
    <tr>
      <td><?php echo implode('</td><td>', $row); ?></td>
    </tr>
<?php endforeach; ?>
  </tbody>
</table>
<?php endif; ?>

Find when a file was deleted in Git

You can find the last commit which deleted file as follows:

git rev-list -n 1 HEAD -- [file_path]

Further information is available here

How to Create Multiple Where Clause Query Using Laravel Eloquent?

You can do it as following, which is the shortest way.

$results = User::where(['this'=>1, 'that'=>1, 'this_too'=>1, 'that_too'=>1, 
          'this_as_well'=>1, 'that_as_well'=>1, 'this_one_too'=>1, 'that_one_too'=>1, 
          'this_one_as_well'=>1, 'that_one_as_well'=>1])->get();

What does ${} (dollar sign and curly braces) mean in a string in Javascript?

You can also perform Implicit Type Conversions with template literals. Example:

let fruits = ["mango","orange","pineapple","papaya"];

console.log(`My favourite fruits are ${fruits}`);
// My favourite fruits are mango,orange,pineapple,papaya

How to get the fragment instance from the FragmentActivity?

To get the fragment instance in a class that extends FragmentActivity:

MyclassFragment instanceFragment=
    (MyclassFragment)getSupportFragmentManager().findFragmentById(R.id.idFragment);

To get the fragment instance in a class that extends Fragment:

MyclassFragment instanceFragment =  
    (MyclassFragment)getFragmentManager().findFragmentById(R.id.idFragment);

sweet-alert display HTML code in text

The SweetAlert repo seems to be unmaintained. There's a bunch of Pull Requests without any replies, the last merged pull request was on Nov 9, 2014.

I created SweetAlert2 with HTML support in modal and some other options for customization modal window - width, padding, Esc button behavior, etc.

_x000D_
_x000D_
Swal.fire({
  title: "<i>Title</i>", 
  html: "Testno  sporocilo za objekt: <b>test</b>",  
  confirmButtonText: "V <u>redu</u>", 
});
_x000D_
<script src="https://cdn.jsdelivr.net/npm/sweetalert2@10"></script>
_x000D_
_x000D_
_x000D_

Vertical line using XML drawable

You can use the rotate attribute

 <item>
    <rotate
        android:fromDegrees="90"
        android:toDegrees="90"
        android:pivotX="50%"
        android:pivotY="50%" >
        <shape
            android:shape="line"
            android:top="1dip" >
            <stroke
                android:width="1dip"
                 />
        </shape>
    </rotate>
</item>

HTTP response code for POST when resource already exists

What about 208 - http://httpstatusdogs.com/208-already-reported ? Is that a option?

In my opinion, if the only thing is a repeat resource no error should be raised. After all, there is no error neither on the client or server sides.

How many socket connections can a web server handle?

In short: You should be able to achieve in the order of millions of simultaneous active TCP connections and by extension HTTP request(s). This tells you the maximum performance you can expect with the right platform with the right configuration.

Today, I was worried whether IIS with ASP.NET would support in the order of 100 concurrent connections (look at my update, expect ~10k responses per second on older ASP.Net Mono versions). When I saw this question/answers, I couldn't resist answering myself, many answers to the question here are completely incorrect.

Best Case

The answer to this question must only concern itself with the simplest server configuration to decouple from the countless variables and configurations possible downstream.

So consider the following scenario for my answer:

  1. No traffic on the TCP sessions, except for keep-alive packets (otherwise you would obviously need a corresponding amount of network bandwidth and other computer resources)
  2. Software designed to use asynchronous sockets and programming, rather than a hardware thread per request from a pool. (ie. IIS, Node.js, Nginx... webserver [but not Apache] with async designed application software)
  3. Good performance/dollar CPU / Ram. Today, arbitrarily, let's say i7 (4 core) with 8GB of RAM.
  4. A good firewall/router to match.
  5. No virtual limit/governor - ie. Linux somaxconn, IIS web.config...
  6. No dependency on other slower hardware - no reading from harddisk, because it would be the lowest common denominator and bottleneck, not network IO.

Detailed Answer

Synchronous thread-bound designs tend to be the worst performing relative to Asynchronous IO implementations.

WhatsApp can handle a million WITH traffic on a single Unix flavoured OS machine - https://blog.whatsapp.com/index.php/2012/01/1-million-is-so-2011/.

And finally, this one, http://highscalability.com/blog/2013/5/13/the-secret-to-10-million-concurrent-connections-the-kernel-i.html, goes into a lot of detail, exploring how even 10 million could be achieved. Servers often have hardware TCP offload engines, ASICs designed for this specific role more efficiently than a general purpose CPU.

Good software design choices

Asynchronous IO design will differ across Operating Systems and Programming platforms. Node.js was designed with asynchronous in mind. You should use Promises at least, and when ECMAScript 7 comes along, async/await. C#/.Net already has full asynchronous support like node.js. Whatever the OS and platform, asynchronous should be expected to perform very well. And whatever language you choose, look for the keyword "asynchronous", most modern languages will have some support, even if it's an add-on of some sort.

To WebFarm?

Whatever the limit is for your particular situation, yes a web-farm is one good solution to scaling. There are many architectures for achieving this. One is using a load balancer (hosting providers can offer these, but even these have a limit, along with bandwidth ceiling), but I don't favour this option. For Single Page Applications with long-running connections, I prefer to instead have an open list of servers which the client application will choose from randomly at startup and reuse over the lifetime of the application. This removes the single point of failure (load balancer) and enables scaling through multiple data centres and therefore much more bandwidth.

Busting a myth - 64K ports

To address the question component regarding "64,000", this is a misconception. A server can connect to many more than 65535 clients. See https://networkengineering.stackexchange.com/questions/48283/is-a-tcp-server-limited-to-65535-clients/48284

By the way, Http.sys on Windows permits multiple applications to share the same server port under the HTTP URL schema. They each register a separate domain binding, but there is ultimately a single server application proxying the requests to the correct applications.

Update 2019-05-30

Here is an up to date comparison of the fastest HTTP libraries - https://www.techempower.com/benchmarks/#section=data-r16&hw=ph&test=plaintext

  • Test date: 2018-06-06
  • Hardware used: Dell R440 Xeon Gold + 10 GbE
  • The leader has ~7M plaintext reponses per second (responses not connections)
  • The second one Fasthttp for golang advertises 1.5M concurrent connections - see https://github.com/valyala/fasthttp
  • The leading languages are Rust, Go, C++, Java, C, and even C# ranks at 11 (6.9M per second). Scala and Clojure rank further down. Python ranks at 29th at 2.7M per second.
  • At the bottom of the list, I note laravel and cakephp, rails, aspnet-mono-ngx, symfony, zend. All below 10k per second. Note, most of these frameworks are build for dynamic pages and quite old, there may be newer variants that feature higher up in the list.
  • Remember this is HTTP plaintext, not for the Websocket specialty: many people coming here will likely be interested in concurrent connections for websocket.

How to monitor SQL Server table changes by using c#?

SqlDependency doesn't watch the database it watches the SqlCommand you specify so if you are trying to lets say insert values into the database in 1 project and capture that event in another project it won't work because the event was from the SqlCommand from the 1º project not the database because when you create an SqlDependency you link it to a SqlCommand and only when that command from that project is used does it create a Change event.

Uncompress tar.gz file

Use -C option of tar:

tar zxvf <yourfile>.tar.gz -C /usr/src/

and then, the content of the tar should be in:

/usr/src/<yourfile>

How to play YouTube video in my Android application?

Use YouTube Android Player API.

activity_main.xml:

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

tools:context="com.example.andreaskonstantakos.vfy.MainActivity">

<com.google.android.youtube.player.YouTubePlayerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:visibility="visible"
    android:layout_centerHorizontal="true"
    android:id="@+id/youtube_player"
    android:layout_alignParentTop="true" />

<Button
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="195dp"
android:visibility="visible"
android:id="@+id/button" />


</RelativeLayout>

MainActivity.java:

package com.example.andreaskonstantakos.vfy;


import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import com.google.android.youtube.player.YouTubeBaseActivity;
import com.google.android.youtube.player.YouTubeInitializationResult;
import com.google.android.youtube.player.YouTubePlayer;
import com.google.android.youtube.player.YouTubePlayerView;



public class MainActivity extends YouTubeBaseActivity {

YouTubePlayerView youTubePlayerView;
Button button;
YouTubePlayer.OnInitializedListener onInitializedListener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

     youTubePlayerView = (YouTubePlayerView) findViewById(R.id.youtube_player);
     button = (Button) findViewById(R.id.button);


     onInitializedListener = new YouTubePlayer.OnInitializedListener(){

         @Override
         public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer youTubePlayer, boolean b) {

            youTubePlayer.loadVideo("Hce74cEAAaE");

             youTubePlayer.play();
     }

         @Override
         public void onInitializationFailure(YouTubePlayer.Provider provider, YouTubeInitializationResult youTubeInitializationResult) {

         }
     };

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

youTubePlayerView.initialize(PlayerConfig.API_KEY,onInitializedListener);
        }
    });
}
}

and the PlayerConfig.java class:

    package com.example.andreaskonstantakos.vfy;

/**
 * Created by Andreas Konstantakos on 13/4/2017.
 */

public class PlayerConfig {

PlayerConfig(){}

public static final String API_KEY = 
"xxxxx";
}

Replace the "Hce74cEAAaE" with your video ID from https://www.youtube.com/watch?v=Hce74cEAAaE. Get your API_KEY from Console.developers.google.com and also replace it on the PlayerConfig.API_KEY. For any further information you can follow the following tutorial step by step: https://www.youtube.com/watch?v=3LiubyYpEUk

Quick Way to Implement Dictionary in C

GLib and gnulib

These are your likely best bets if you don't have more specific requirements, since they are widely available, portable and likely efficient.

See also: Are there any open source C libraries with common data structures?

Convert iterator to pointer?

A safe version to convert an iterator to a pointer (exactly what that means regardless of the implications) and by safe I mean no worries about having to dereference the iterator and cause possible exceptions / errors due to end() / other situations

#include <iostream>
#include <vector>
#include <string.h>

int main()
{
    std::vector<int> vec;

    char itPtr[25];
    long long itPtrDec;
    
    std::vector<int>::iterator it = vec.begin();
    memset(&itPtr, 0, 25);
    sprintf(itPtr, "%llu", it);
    itPtrDec = atoll(itPtr);
    printf("it = 0x%X\n", itPtrDec);
    
    vec.push_back(123);
    it = vec.begin();
    memset(&itPtr, 0, 25);
    sprintf(itPtr, "%llu", it);
    itPtrDec = atoll(itPtr);
    printf("it = 0x%X\n", itPtrDec);
}

will print something like

it = 0x0

it = 0x2202E10

It's an incredibly hacky way to do it, but if you need it, it does the job. You will receive some compiler warnings which, if really bothering you, can be removed with #pragma

How can I read large text files in Python, line by line, without loading it into memory?

You are better off using an iterator instead. Relevant: http://docs.python.org/library/fileinput.html

From the docs:

import fileinput
for line in fileinput.input("filename"):
    process(line)

This will avoid copying the whole file into memory at once.

ASP.NET Forms Authentication failed for the request. Reason: The ticket supplied has expired

Sounds like an error you would get when your forms authentication ticket has expired. What is the timeout period for your ticket? Is it set to sliding or absolute expiration?

I believe the default for the timeout is 20 minutes with sliding expiration so if a user gets authenticated and at some point doesn't hit your site for 20 minutes their ticket would be expired. If it is set to absolute expiration it will expire X number of minutes after it was issued where X is your timeout setting.

You can set the timeout and expiration policy (e.g. sliding, absolute) in your web/machine.config under /configuration/system.web/authentication/forms

AppCompat v7 r21 returning error in values.xml?

I vote whoever can solve like me. I had this same problem as u , I spent many hours to get correct . Please test .

Upgrade entire SDK , the update 21.0.2 build also has updates from Google Services play . Upgrade everything. In your workspace delete folders ( android -support- v7 - AppCompat ) and ( google -play - services_lib )

Re-import these projects into the IDE and select to copy them to your workspace again.

The project ( google -play - services_lib ) to perform the action of Refresh and Build

**** ***** Problem The project ( android -support- v7 - AppCompat ) mark the 5.0 API then Refresh and Build .

In his project , in properties , android , import libraries ( android -support- v7 - AppCompat ) and ( google -play - services_lib ) then Refresh and Build .

Visual Studio 2015 Update 3 Offline Installer (ISO)

The ISO file that suggested in the accepted answer is still not complete. The very complete offline installer is about 24GB! There is only one way to get it. follow these steps:

  1. Download Web Installer from Microsoft Web Site
  2. Execute the Installer. NOTE: the installer is still a simple downloader for the real web-installer.
  3. After running the real web installer, Run Windows Task manager and find the real web installer path that is stored in your temp folder
  4. copy the real installer somewhere else. like C:\VS Community\
  5. Open Command Prompt and execute the installer that you copied to C:\VS Community\ with this argument: /Layout .
  6. Now installer will download the FULL offline installer to your selected folder!

Good Luck

SQL Server ORDER BY date and nulls last

order by -cast([Next_Contact_Date] as bigint) desc

TimeStamp on file name using PowerShell

You can insert arbitrary PowerShell script code in a double-quoted string by using a subexpression, for example, $() like so:

"C:\temp\mybackup $(get-date -f yyyy-MM-dd).zip"

And if you are getting the path from somewhere else - already as a string:

$dirName  = [io.path]::GetDirectoryName($path)
$filename = [io.path]::GetFileNameWithoutExtension($path)
$ext      = [io.path]::GetExtension($path)
$newPath  = "$dirName\$filename $(get-date -f yyyy-MM-dd)$ext"

And if the path happens to be coming from the output of Get-ChildItem:

Get-ChildItem *.zip | Foreach {
  "$($_.DirectoryName)\$($_.BaseName) $(get-date -f yyyy-MM-dd)$($_.extension)"}

Read file from aws s3 bucket using node fs

var fileStream = fs.createWriteStream('/path/to/file.jpg');
var s3Stream = s3.getObject({Bucket: 'myBucket', Key: 'myImageFile.jpg'}).createReadStream();

// Listen for errors returned by the service
s3Stream.on('error', function(err) {
    // NoSuchKey: The specified key does not exist
    console.error(err);
});

s3Stream.pipe(fileStream).on('error', function(err) {
    // capture any errors that occur when writing data to the file
    console.error('File Stream:', err);
}).on('close', function() {
    console.log('Done.');
});

Reference: https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/requests-using-stream-objects.html

Setting table column width

Alternative way with just one class while keeping your styles in a CSS file, which even works in IE7:

<table class="mytable">
    <tr>
        <th>From</th>
        <th>Subject</th>
        <th>Date</th>
    </tr>
</table>
<style>
    .mytable td, .mytable th { width:15%; }
    .mytable td + td, .mytable th + th { width:70%; }
    .mytable td + td + td, .mytable th + th + th { width:15%; }
</style>

More recently, you can also use the nth-child() selector from CSS3 (IE9+), where you'd just put the nr. of the respective column into the parenthesis instead of stringing them together with the adjacent selector. Like this, for example:

<style>
    .mytable tr > *:nth-child(1) { width:15%; }
    .mytable tr > *:nth-child(2) { width:70%; }
    .mytable tr > *:nth-child(3) { width:15%; }
</style>

In C++, what is a virtual base class?

It means a call to a virtual function will be forwarded to the "right" class.

C++ FAQ Lite FTW.

In short, it is often used in multiple-inheritance scenarios, where a "diamond" hierarchy is formed. Virtual inheritance will then break the ambiguity created in the bottom class, when you call function in that class and the function needs to be resolved to either class D1 or D2 above that bottom class. See the FAQ item for a diagram and details.

It is also used in sister delegation, a powerful feature (though not for the faint of heart). See this FAQ.

Also see Item 40 in Effective C++ 3rd edition (43 in 2nd edition).

java.net.SocketException: Software caused connection abort: recv failed

I too had this problem. My solution was:

sc.setSoLinger(true, 10);

COPY FROM A WEBSITE -->By using the setSoLinger() method, you can explicitly set a delay before a reset is sent, giving more time for data to be read or send.

Maybe it is not the answer to everybody but to some people.

Deserialize JSON to ArrayList<POJO> using Jackson

You can deserialize directly to a list by using the TypeReference wrapper. An example method:

public static <T> T fromJSON(final TypeReference<T> type,
      final String jsonPacket) {
   T data = null;

   try {
      data = new ObjectMapper().readValue(jsonPacket, type);
   } catch (Exception e) {
      // Handle the problem
   }
   return data;
}

And is used thus:

final String json = "";
Set<POJO> properties = fromJSON(new TypeReference<Set<POJO>>() {}, json);

TypeReference Javadoc

NameError: name 'python' is not defined

When you run the Windows Command Prompt, and type in python, it starts the Python interpreter.

Typing it again tries to interpret python as a variable, which doesn't exist and thus won't work:

Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\USER>python
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> python
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'python' is not defined
>>> print("interpreter has started")
interpreter has started
>>> quit() # leave the interpreter, and go back to the command line

C:\Users\USER>

If you're not doing this from the command line, and instead running the Python interpreter (python.exe or IDLE's shell) directly, you are not in the Windows Command Line, and python is interpreted as a variable, which you have not defined.

Error : java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init>(I)V

I encountered the same error when added http-builder to dependencies.
In my case, I could solve by simply excluding asm like this:

compile('org.codehaus.groovy.modules.http-builder:http-builder:0.7'){
    excludes 'xml-apis'
    exclude(group:'xerces', module: 'xercesImpl')
    excludes 'asm'
}

Signing a Windows EXE file

Another option, if you need to sign the executable on a Linux box is to use signcode from the Mono project tools. It is supported on Ubuntu.

Include PHP file into HTML file

You would have to configure your webserver to utilize PHP as handler for .html files. This is typically done by modifying your with AddHandler to include .html along with .php.

Note that this could have a performance impact as this would cause ALL .html files to be run through PHP handler even if there is no PHP involved. So you might strongly consider using .php extension on these files and adding a redirect as necessary to route requests to specific .html URL's to their .php equivalents.

Timing Delays in VBA

I used the answer of Steve Mallory, but I am affraid the timer never or at least sometimes does not go to 86400 nor 0 (zero) sharp (MS Access 2013). So I modified the code. I changed the midnight condition to "If Timer >= 86399 Then" and added the break of the loop "Exit Do" as follows:

Public Function Pause(NumberOfSeconds As Variant)
    On Error GoTo Error_GoTo

    Dim PauseTime As Variant
    Dim Start As Variant
    Dim Elapsed As Variant

    PauseTime = NumberOfSeconds
    Start = Timer
    Elapsed = 0
    Do While Timer < Start + PauseTime
        Elapsed = Elapsed + 1
        If Timer >= 86399
            ' Crossing midnight
            ' PauseTime = PauseTime - Elapsed
            ' Start = 0
            ' Elapsed = 0
            Exit Do
        End If
        DoEvents
    Loop

Exit_GoTo:
    On Error GoTo 0
    Exit Function
Error_GoTo:
    Debug.Print Err.Number, Err.Description, Erl
    GoTo Exit_GoTo
End Function

How to list all the roles existing in Oracle database?

all_roles.sql

SELECT SUBSTR(TRIM(rtp.role),1,12)          AS ROLE
     , SUBSTR(rp.grantee,1,16)              AS GRANTEE
     , SUBSTR(TRIM(rtp.privilege),1,12)     AS PRIVILEGE
     , SUBSTR(TRIM(rtp.owner),1,12)         AS OWNER
     , SUBSTR(TRIM(rtp.table_name),1,28)    AS TABLE_NAME
     , SUBSTR(TRIM(rtp.column_name),1,20)   AS COLUMN_NAME
     , SUBSTR(rtp.common,1,4)               AS COMMON
     , SUBSTR(rtp.grantable,1,4)            AS GRANTABLE
     , SUBSTR(rp.default_role,1,16)         AS DEFAULT_ROLE
     , SUBSTR(rp.admin_option,1,4)          AS ADMIN_OPTION
  FROM role_tab_privs rtp
  LEFT JOIN dba_role_privs rp
    ON (rtp.role = rp.granted_role)
 WHERE ('&1' IS NULL OR UPPER(rtp.role) LIKE UPPER('%&1%'))
   AND ('&2' IS NULL OR UPPER(rp.grantee) LIKE UPPER('%&2%'))
   AND ('&3' IS NULL OR UPPER(rtp.table_name) LIKE UPPER('%&3%'))
   AND ('&4' IS NULL OR UPPER(rtp.owner) LIKE UPPER('%&4%'))
 ORDER BY 1
        , 2
        , 3
        , 4
;

Usage

SQLPLUS> @all_roles '' '' '' '' '' ''
SQLPLUS> @all_roles 'somerol' '' '' '' '' ''
SQLPLUS> @all_roles 'roler' 'username' '' '' '' ''
SQLPLUS> @all_roles '' '' 'part-of-database-package-name' '' '' ''
etc.

How to get the value from the GET parameters?

The easiest way using the replace() method:

From the urlStr string:

paramVal = urlStr.replace(/.*param_name=([^&]*).*|(.*)/, '$1');

or from the current URL:

paramVal = document.URL.replace(/.*param_name=([^&]*).*|(.*)/, '$1');

Explanation:

  • document.URL - interface returns the document location (page url) as a string.
  • replace() - method returns a new string with some or all matches of a pattern replaced by a replacement.
  • /.*param_name=([^&]*).*/ - the regular expression pattern enclosed between slashes which means:
    • .* - zero or more of any characters,
    • param_name= - param name which is serched,
    • () - group in regular expression,
    • [^&]* - one or more of any characters excluding &,
    • | - alternation,
    • $1 - reference to first group in regular expression.

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var urlStr = 'www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5';_x000D_
var c = urlStr.replace(/.*c=([^&]*).*|(.*)/, '$1');_x000D_
var notExisted = urlStr.replace(/.*not_existed=([^&]*).*|(.*)/, '$1');_x000D_
console.log(`c === '${c}'`);_x000D_
console.log(`notExisted === '${notExisted}'`);
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Find oldest/youngest datetime object in a list

Oldest:

oldest = min(datetimes)

Youngest before now:

now = datetime.datetime.now(pytz.utc)
youngest = max(dt for dt in datetimes if dt < now)

How do you get the current text contents of a QComboBox?

If you want the text value of a QString object you can use the __str__ property, like this:

>>> a = QtCore.QString("Happy Happy, Joy Joy!")
>>> a
PyQt4.QtCore.QString(u'Happy Happy, Joy Joy!')
>>> a.__str__()
u'Happy Happy, Joy Joy!'

Hope that helps.

Display unescaped HTML in Vue.js

Starting with Vue2, the triple braces were deprecated, you are to use v-html.

<div v-html="task.html_content"> </div>

It is unclear from the documentation link as to what we are supposed to place inside v-html, your variables goes inside v-html.

Also, v-html works only with <div> or <span> but not with <template>.

If you want to see this live in an app, click here.

Function vs. Stored Procedure in SQL Server

SQL Server functions, like cursors, are meant to be used as your last weapon! They do have performance issues and therefore using a table-valued function should be avoided as much as possible. Talking about performance is talking about a table with more than 1,000,000 records hosted on a server on a middle-class hardware; otherwise you don't need to worry about the performance hit caused by the functions.

  1. Never use a function to return a result-set to an external code (like ADO.Net)
  2. Use views/stored procs combination as much as possible. you can recover from future grow-performance issues using the suggestions DTA (Database Tuning Adviser) would give you (like indexed views and statistics) --sometimes!

for further reference see: http://databases.aspfaq.com/database/should-i-use-a-view-a-stored-procedure-or-a-user-defined-function.html

How to remove all options from a dropdown using jQuery / JavaScript

Anyone using JavaScript (as opposed to JQuery), might like to try this solution, where 'models' is the ID of the select field containing the list :-

var DDlist = document.getElementById("models");
while(DDlist.length>0){DDlist.remove(0);}

session handling in jquery

Assuming you're referring to this plugin, your code should be:

// To Store
$(function() {
    $.session.set("myVar", "value");
});


// To Read
$(function() {
    alert($.session.get("myVar"));
});

Before using a plugin, remember to read its documentation in order to learn how to use it. In this case, an usage example can be found in the README.markdown file, which is displayed on the project page.

Access properties file programmatically with Spring?

I have done this and it has worked.

Properties props = PropertiesLoaderUtils.loadAllProperties("my.properties");
PropertyPlaceholderConfigurer props2 = new PropertyPlaceholderConfigurer();
props2.setProperties(props);

That should work.

Process.start: how to get the output?

  1. It is possible to get the command line shell output of a process as described here : http://www.c-sharpcorner.com/UploadFile/edwinlima/SystemDiagnosticProcess12052005035444AM/SystemDiagnosticProcess.aspx

  2. This depends on mencoder. If it ouputs this status on the command line then yes :)

How do I get current URL in Selenium Webdriver 2 Python?

Another way to do it would be to inspect the url bar in chrome to find the id of the element, have your WebDriver click that element, and then send the keys you use to copy and paste using the keys common function from selenium, and then printing it out or storing it as a variable, etc.

Change border-bottom color using jquery?

to modify more css property values, you may use css object. such as:

hilight_css = {"border-bottom-color":"red", 
               "background-color":"#000"};
$(".msg").css(hilight_css);

but if the modification code is bloated. you should consider the approach March suggested. do it this way:

first, in your css file:

.hilight { border-bottom-color:red; background-color:#000; }
.msg { /* something to make it notifiable */ }

second, in your js code:

$(".msg").addClass("hilight");
// to bring message block to normal
$(".hilight").removeClass("hilight");

if ie 6 is not an issue, you can chain these classes to have more specific selectors.

Difference between abstraction and encapsulation?

I will try to demonstrate Encapsulation in a simple way.. Lets see..

  • The wrapping up of data and functions into a single unit (called class) is known as encapsulation. Encapsulation containing and hiding information about an object, such as internal data structures and code.

Encapsulation is -

  • Hiding Complexity,
  • Binding Data and Function together,
  • Making Complicated Method's Private,
  • Making Instance Variable's Private,
  • Hiding Unnecessary Data and Functions from End User.

Encapsulation implements Abstraction.

And Abstraction is -

  • Showing Whats Necessary,
  • Data needs to abstract from End User,

Lets see an example-

The below Image shows a GUI of "Customer Details to be ADD-ed into a Database".

Customer Screen GUI

By looking at the Image we can say that we need a Customer Class.

Step - 1: What does my Customer Class needs?

i.e.

  • 2 variables to store Customer Code and Customer Name.
  • 1 Function to Add the Customer Code and Customer Name into Database.

    namespace CustomerContent { public class Customer { public string CustomerCode = ""; public string CustomerName = ""; public void ADD() { //my DB code will go here }

Now only ADD method wont work here alone.

Step -2: How will the validation work, ADD Function act?

We will need Database Connection code and Validation Code (Extra Methods).

public bool Validate()
{
    //Granular Customer Code and Name
    return true;
}

public bool CreateDBObject()
{
    //DB Connection Code
    return true;
}


class Program
{
static void main(String[] args)
{
CustomerComponent.Customer obj = new CustomerComponent.Customer;

obj.CustomerCode = "s001";
obj.CustomerName = "Mac";

obj.Validate();
obj.CreateDBObject();

obj.ADD();
}
}

Now there is no need of showing the Extra Methods(Validate(); CreateDBObject() [Complicated and Extra method] ) to the End User.End user only needs to see and know about Customer Code, Customer Name and ADD button which will ADD the record.. End User doesn't care about HOW it will ADD the Data to Database?.

Step -3: Private the extra and complicated methods which doesn't involves End User's Interaction.

So making those Complicated and Extra method as Private instead Public(i.e Hiding those methods) and deleting the obj.Validate(); obj.CreateDBObject(); from main in class Program we achieve Encapsulation.

In other words Simplifying Interface to End User is Encapsulation.

So now the code looks like as below -

namespace CustomerContent
{
public class Customer
{
public string CustomerCode = "";
public string CustomerName = "";
public void ADD()
{
   //my DB code will go here
}

private bool Validate()
{
    //Granular Customer Code and Name
    return true;
}

private bool CreateDBObject()
{
    //DB Connection Code
    return true;
}


class Program
{
static void main(String[] args)
{
CustomerComponent.Customer obj = new CustomerComponent.Customer;

obj.CustomerCode = "s001";

obj.CustomerName = "Mac";

obj.ADD();
}
}

Summary :

Step -1: What does my Customer Class needs? is Abstraction.

Step -3: Step -3: Private the extra and complicated methods which doesn't involves End User's Interaction is Encapsulation.

P.S. - The code above is hard and fast.

How do I change the string representation of a Python class?

The closest equivalent to Java's toString is to implement __str__ for your class. Put this in your class definition:

def __str__(self):
     return "foo"

You may also want to implement __repr__ to aid in debugging.

See here for more information:

android - setting LayoutParams programmatically

after creating the view we have to add layout parameters .

change like this

TextView tv = new TextView(this);
tv.setLayoutParams(new ViewGroup.LayoutParams(
        ViewGroup.LayoutParams.WRAP_CONTENT,
        ViewGroup.LayoutParams.WRAP_CONTENT));

llview.addView(tv);
tv.setTextColor(Color.WHITE);
tv.setTextSize(2,25);
tv.setText(chat);
if (mine) {
    leftMargin = 5;
    tv.setBackgroundColor(0x7C5B77);
}
else {
    leftMargin = 50;
    tv.setBackgroundColor(0x778F6E);
}
final ViewGroup.MarginLayoutParams lpt =(MarginLayoutParams)tv.getLayoutParams();
lpt.setMargins(leftMargin,lpt.topMargin,lpt.rightMargin,lpt.bottomMargin);

CSS: fixed to bottom and centered

I ran into a problem where the typical position: fixed and bottom: 0 didn't work. Discovered a neat functionality with position: sticky. Note it's "relatively" new so it won't with IE/Edge 15 and earlier.

Here's an example for w3schools.

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_x000D_
<!DOCTYPE html>
<html>
<head>
<style>
div.sticky {
  position: sticky;
  bottom: 0;
  background-color: yellow;
  padding: 30px;
  font-size: 20px;
}
</style>
</head>
<body>

<p>Lorem ipsum dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas nisl est,  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dlerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dlerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dlerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dlerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas  dolor nteger frinegestas odio, vitae scelerisque enim ligula venenatis dolor. Maecenas </p>

<div class="sticky">I will stick to the screen when you reach my scroll position</div>

</body>
</html>
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How do I add a margin between bootstrap columns without wrapping

If you do not need to add a border on columns, you can also simply add a transparent border on them:

[class*="col-"] {
    background-clip: padding-box;
    border: 10px solid transparent;
}

Using moment.js to convert date to string "MM/dd/yyyy"

StartDate = moment(StartDate).format('MM-YYYY');

...and MySQL date format:

StartDate = moment(StartDate).format('YYYY-MM-DD');

C/C++ include header file order

This is not subjective. Make sure your headers don't rely on being #included in specific order. You can be sure it doesn't matter what order you include STL or Boost headers.

Safest way to run BAT file from Powershell script

Try this, your dot source was a little off. Edit, adding lastexitcode bits for OP.

$A = Start-Process -FilePath .\my-app\my-fle.bat -Wait -passthru;$a.ExitCode

add -WindowStyle Hidden for invisible batch.

How do I zip two arrays in JavaScript?

Zip Arrays of same length:

Using Array.prototype.map()

_x000D_
_x000D_
const zip = (a, b) => a.map((k, i) => [k, b[i]]);

console.log(zip([1,2,3], ["a","b","c"]));
// [[1, "a"], [2, "b"], [3, "c"]]
_x000D_
_x000D_
_x000D_

Zip Arrays of different length:

Using Array.from()

_x000D_
_x000D_
const zip = (a, b) => Array.from(Array(Math.max(b.length, a.length)), (_, i) => [a[i], b[i]]);

console.log( zip([1,2,3], ["a","b","c","d"]) );
// [[1, "a"], [2, "b"], [3, "c"], [undefined, "d"]]
_x000D_
_x000D_
_x000D_

Using Array.prototype.fill() and Array.prototype.map()

_x000D_
_x000D_
const zip = (a, b) => Array(Math.max(b.length, a.length)).fill().map((_,i) => [a[i], b[i]]);

console.log(zip([1,2,3], ["a","b","c","d"]));
// [[1, "a"], [2, "b"], [3, "c"], [undefined, 'd']]
_x000D_
_x000D_
_x000D_

How to revert the last migration?

If you are facing trouble while reverting back the migration, and somehow have messed it, you can perform fake migrations.

./manage.py migrate <name> --ignore-ghost-migrations --merge --fake

For django version < 1.7 this will create entry in south_migrationhistory table, you need to delete that entry.

Now you'll be able to revert back the migration easily.

PS: I was stuck for a lot of time and performing fake migration and then reverting back helped me out.

Set active tab style with AngularJS

Following Pavel's advice to use a custom directive, here's a version that requires adding no payload to the routeConfig, is super declarative, and can be adapted to react to any level of the path, by simply changing which slice() of it you're paying attention to.

app.directive('detectActiveTab', function ($location) {
    return {
      link: function postLink(scope, element, attrs) {
        scope.$on("$routeChangeSuccess", function (event, current, previous) {
            /*  
                Designed for full re-usability at any path, any level, by using 
                data from attrs. Declare like this: 
                <li class="nav_tab">
                  <a href="#/home" detect-active-tab="1">HOME</a>
                </li> 
            */

            // This var grabs the tab-level off the attribute, or defaults to 1
            var pathLevel = attrs.detectActiveTab || 1,
            // This var finds what the path is at the level specified
                pathToCheck = $location.path().split('/')[pathLevel] || 
                  "current $location.path doesn't reach this level",
            // This var finds grabs the same level of the href attribute
                tabLink = attrs.href.split('/')[pathLevel] || 
                  "href doesn't include this level";
            // Above, we use the logical 'or' operator to provide a default value
            // in cases where 'undefined' would otherwise be returned.
            // This prevents cases where undefined===undefined, 
            // possibly causing multiple tabs to be 'active'.

            // now compare the two:
            if (pathToCheck === tabLink) {
              element.addClass("active");
            }
            else {
              element.removeClass("active");
            }
        });
      }
    };
  });

We're accomplishing our goals by listening for the $routeChangeSuccess event, rather than by placing a $watch on the path. I labor under the belief that this means the logic should run less often, as I think watches fire on each $digest cycle.

Invoke it by passing your path-level argument on the directive declaration. This specifies what chunk of the current $location.path() you want to match your href attribute against.

<li class="nav_tab"><a href="#/home" detect-active-tab="1">HOME</a></li>

So, if your tabs should react to the base-level of the path, make the argument '1'. Thus, when location.path() is "/home", it will match against the "#/home" in the href. If you have tabs that should react to the second level, or third, or 11th of the path, adjust accordingly. This slicing from 1 or greater will bypass the nefarious '#' in the href, which will live at index 0.

The only requirement is that you invoke on an <a>, as the element is assuming the presence of an href attribute, which it will compare to the current path. However, you could adapt fairly easily to read/write a parent or child element, if you preferred to invoke on the <li> or something. I dig this because you can re-use it in many contexts by simply varying the pathLevel argument. If the depth to read from was assumed in the logic, you'd need multiple versions of the directive to use with multiple parts of the navigation.


EDIT 3/18/14: The solution was inadequately generalized, and would activate if you defined an arg for the value of 'activeTab' that returned undefined against both $location.path(), and the element's href. Because: undefined === undefined. Updated to fix that condition.

While working on that, I realized there should have been a version you can just declare on a parent element, with a template structure like this:

<nav id="header_tabs" find-active-tab="1">
    <a href="#/home" class="nav_tab">HOME</a>
    <a href="#/finance" class="nav_tab">Finance</a>
    <a href="#/hr" class="nav_tab">Human Resources</a>
    <a href="#/quarterly" class="nav_tab">Quarterly</a>
</nav>

Note that this version no longer remotely resembles Bootstrap-style HTML. But, it's more modern and uses fewer elements, so I'm partial to it. This version of the directive, plus the original, are now available on Github as a drop-in module you can just declare as a dependency. I'd be happy to Bower-ize them, if anybody actually uses them.

Also, if you want a bootstrap-compatible version that includes <li>'s, you can go with the angular-ui-bootstrap Tabs module, which I think came out after this original post, and which is perhaps even more declarative than this one. It's less concise for basic stuff, but provides you with some additional options, like disabled tabs and declarative events that fire on activate and deactivate.

Define static method in source-file with declaration in header-file in C++

Static member functions must refer to static variables of that class. So in your case,

static void CP_StringToPString( std::string& inString, unsigned char *outString);

Since your member function CP_StringToPstring is static, the parameters in that function, inString and outString should be declared as static too.

The static member functions does not refer to the object that it is working on but the variables your declared refers to its current object so it return error.

You could either remove the static from the member function or add static while declaring the parameters you used for the member function as static too.

JavaScript: undefined !== undefined?

From - JQuery_Core_Style_Guidelines

  • Global Variables:
    typeof variable === "undefined"

  • Local Variables:
    variable === undefined

  • Properties:
    object.prop === undefined

How to resize an image to fit in the browser window?

I had a similar requirement, and had to do it it basic CSS and JavaScript. No JQuery available.

This is what I got working.

<html>
      <head>
            <style>
                   img {
                          max-width: 95% !important;
                          max-height: 95% !important;
                       }
            </style>
            <script>
                   function FitImagesToScreen() {
                      var images = document.getElementsByTagName('img');
                      if(images.length > 0){
                         for(var i=0; i < images.length; i++){
                             if(images[i].width >= (window.innerWidth - 10)){
                                 images[i].style.width = 'auto';
                               }
                            }
                         }
                   }
             </script>
      </head>
      <body onload='FitImagesToScreen()'>
      ----    
      </body>
</html>

Note : I haven't used 100% for image width as there was always a bit of padding to be considered.

Setting multiple attributes for an element at once with JavaScript

You could code an ES5.1 helper function:

function setAttributes(el, attrs) {
    Object.keys(attrs).forEach(key => el.setAttribute(key, attrs[key]));
}

Call it like this:

setAttributes(elem, { src: 'http://example.com/something.jpeg', height: '100%' });

Can't update: no tracked branch

Create a new folder and run git init in it.

Then try git remote add origin <your-repository-url>.

Copy all the files in your project folder to the new folder, except the .git folder (it may be invisible).

Then you can push your code by doing:
git add --all; or git add -A;
git commit -m "YOUR MESSAGE";
git push -u origin master.

I think it will work!

How do you clear the console screen in C?

printf("\e[1;1H\e[2J");

This function will work on ANSI terminals, demands POSIX. I assume there is a version that might also work on window's console, since it also supports ANSI escape sequences.

#include <unistd.h>

void clearScreen()
{
  const char *CLEAR_SCREEN_ANSI = "\e[1;1H\e[2J";
  write(STDOUT_FILENO, CLEAR_SCREEN_ANSI, 12);
}

There are some other alternatives, some of which don't move the cursor to {1,1}.

When should I use UNSIGNED and SIGNED INT in MySQL?

For negative integer value, SIGNED is used and for non-negative integer value, UNSIGNED is used. It always suggested to use UNSIGNED for id as a PRIMARY KEY.

ORDER BY items must appear in the select list if SELECT DISTINCT is specified

You could try a subquery:

SELECT DISTINCT TEST.* FROM (
    SELECT rsc.RadioServiceCodeId,
        rsc.RadioServiceCode + ' - ' + rsc.RadioService as RadioService
    FROM sbi_l_radioservicecodes rsc
       INNER JOIN sbi_l_radioservicecodegroups rscg ON  rsc.radioservicecodeid = rscg.radioservicecodeid
    WHERE rscg.radioservicegroupid IN 
       (select val from dbo.fnParseArray(@RadioServiceGroup,','))
        OR @RadioServiceGroup IS NULL  
    ORDER BY rsc.RadioServiceCode,rsc.RadioServiceCodeId,rsc.RadioService
) as TEST

mysql said: Cannot connect: invalid settings. xampp

$cfg['Servers'][$i]['host'] = '127.0.0.1:3307';

if u change port address

How to set the margin or padding as percentage of height of parent container?

To make the child element positioned absolutely from its parent element you need to set relative position on the parent element AND absolute position on the child element.

Then on the child element 'top' is relative to the height of the parent. So you also need to 'translate' upward the child 50% of its own height.

_x000D_
_x000D_
.base{_x000D_
    background-color: green;_x000D_
    width: 200px;_x000D_
    height: 200px;_x000D_
    overflow: auto;_x000D_
    position: relative;_x000D_
}_x000D_
    _x000D_
.vert-align {_x000D_
    position: absolute;_x000D_
    top: 50%;_x000D_
    transform: translate(0, -50%);_x000D_
}
_x000D_
    <div class="base">_x000D_
        <div class="vert-align">_x000D_
            Content Here_x000D_
        </div>_x000D_
    </div>
_x000D_
_x000D_
_x000D_

There is another a solution using flex box.

_x000D_
_x000D_
.base{_x000D_
    background-color:green;_x000D_
    width: 200px;_x000D_
    height: 200px;_x000D_
    overflow: auto;_x000D_
    display: flex;_x000D_
    align-items: center;_x000D_
}
_x000D_
<div class="base">_x000D_
    <div class="vert-align">_x000D_
        Content Here_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

You will find advantages/disavantages for both.

How to install .MSI using PowerShell

After some trial and tribulation, I was able to find all .msi files in a given directory and install them.

foreach($_msiFiles in 
($_msiFiles = Get-ChildItem $_Source -Recurse | Where{$_.Extension -eq ".msi"} |
 Where-Object {!($_.psiscontainter)} | Select-Object -ExpandProperty FullName)) 
{
    msiexec /i $_msiFiles /passive
}

Using Notepad++ to validate XML against an XSD

  1. In Notepad++ go to Plugins > Plugin manager > Show Plugin Manager then find Xml Tools plugin. Tick the box and click Install

    enter image description here

  2. Open XML document you want to validate and click Ctrl+Shift+Alt+M (Or use Menu if this is your preference Plugins > XML Tools > Validate Now).
    Following dialog will open: enter image description here

  3. Click on .... Point to XSD file and I am pretty sure you'll be able to handle things from here.

Hope this saves you some time.

EDIT: Plugin manager was not included in some versions of Notepad++ because many users didn't like commercials that it used to show. If you want to keep an older version, however still want plugin manager, you can get it on github, and install it by extracting the archive and copying contents to plugins and updates folder.
In version 7.7.1 plugin manager is back under a different guise... Plugin Admin so now you can simply update notepad++ and have it back.

enter image description here

Make a nav bar stick

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  _x000D_
  $(window).scroll(function () {_x000D_
      //if you hard code, then use console_x000D_
      //.log to determine when you want the _x000D_
      //nav bar to stick.  _x000D_
      console.log($(window).scrollTop())_x000D_
    if ($(window).scrollTop() > 280) {_x000D_
      $('#nav_bar').addClass('navbar-fixed');_x000D_
    }_x000D_
    if ($(window).scrollTop() < 281) {_x000D_
      $('#nav_bar').removeClass('navbar-fixed');_x000D_
    }_x000D_
  });_x000D_
});
_x000D_
html, body {_x000D_
 height: 4000px;_x000D_
}_x000D_
_x000D_
.navbar-fixed {_x000D_
    top: 0;_x000D_
    z-index: 100;_x000D_
  position: fixed;_x000D_
    width: 100%;_x000D_
}_x000D_
_x000D_
#body_div {_x000D_
 top: 0;_x000D_
 position: relative;_x000D_
    height: 200px;_x000D_
    background-color: green;_x000D_
}_x000D_
_x000D_
#banner {_x000D_
 width: 100%;_x000D_
 height: 273px;_x000D_
    background-color: gray;_x000D_
 overflow: hidden;_x000D_
}_x000D_
_x000D_
#nav_bar {_x000D_
 border: 0;_x000D_
 background-color: #202020;_x000D_
 border-radius: 0px;_x000D_
 margin-bottom: 0;_x000D_
    height: 30px;_x000D_
}_x000D_
_x000D_
.nav_links {_x000D_
    margin: 0;_x000D_
}_x000D_
_x000D_
.nav_links li {_x000D_
 display: inline-block;_x000D_
    margin-top: 4px;_x000D_
}_x000D_
.nav_links li a {_x000D_
 padding: 0 15.5px;_x000D_
 color: #3498db;_x000D_
 text-decoration: none;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div id="banner">_x000D_
     <h2>put what you want here</h2>_x000D_
     <p>just adjust javascript size to match this window</p>_x000D_
  </div>_x000D_
_x000D_
  <nav id='nav_bar'>_x000D_
    <ul class='nav_links'>_x000D_
      <li><a href="url">Nav Bar</a></li>_x000D_
      <li><a href="url">Sign In</a></li>_x000D_
      <li><a href="url">Blog</a></li>_x000D_
      <li><a href="url">About</a></li>_x000D_
    </ul>_x000D_
  </nav>_x000D_
<div id='body_div'>_x000D_
    <p style='margin: 0; padding-top: 50px;'>and more stuff to continue scrolling here</p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Determine the line of code that causes a segmentation fault?

All of the above answers are correct and recommended; this answer is intended only as a last-resort if none of the aforementioned approaches can be used.

If all else fails, you can always recompile your program with various temporary debug-print statements (e.g. fprintf(stderr, "CHECKPOINT REACHED @ %s:%i\n", __FILE__, __LINE__);) sprinkled throughout what you believe to be the relevant parts of your code. Then run the program, and observe what the was last debug-print printed just before the crash occurred -- you know your program got that far, so the crash must have happened after that point. Add or remove debug-prints, recompile, and run the test again, until you have narrowed it down to a single line of code. At that point you can fix the bug and remove all of the temporary debug-prints.

It's quite tedious, but it has the advantage of working just about anywhere -- the only times it might not is if you don't have access to stdout or stderr for some reason, or if the bug you are trying to fix is a race-condition whose behavior changes when the timing of the program changes (since the debug-prints will slow down the program and change its timing)

How to invoke a Linux shell command from Java

exec does not execute a command in your shell

try

Process p = Runtime.getRuntime().exec(new String[]{"csh","-c","cat /home/narek/pk.txt"});

instead.

EDIT:: I don't have csh on my system so I used bash instead. The following worked for me

Process p = Runtime.getRuntime().exec(new String[]{"bash","-c","ls /home/XXX"});

How to set dropdown arrow in spinner?

copy and paste this xml instead of your xml

<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/back1"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp" 
        android:background="@drawable/red">

        <Spinner
            android:id="@+id/spinner1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:dropDownWidth="fill_parent" 
            android:background="@android:drawable/btn_dropdown"
         />

    </LinearLayout>

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignLeft="@+id/linearLayout1"
        android:layout_alignRight="@+id/linearLayout1"
        android:layout_below="@+id/linearLayout1"
        android:layout_marginTop="25dp"
        android:background="@drawable/red"
        android:ems="10"
        android:hint="enter card number" >

        <requestFocus />
    </EditText>

    <LinearLayout
        android:id="@+id/linearLayout2"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignLeft="@+id/editText1"
        android:layout_alignRight="@+id/editText1"
        android:layout_below="@+id/editText1"
        android:layout_marginTop="33dp"
        android:orientation="horizontal" 
        android:background="@drawable/red">

        <Spinner
            android:id="@+id/spinner3"
            android:layout_width="72dp"
            android:layout_height="wrap_content"
            android:background="@android:drawable/btn_dropdown"
             />

        <Spinner
            android:id="@+id/spinner2"
            android:layout_width="72dp"
            android:layout_height="wrap_content" 
            android:background="@android:drawable/btn_dropdown"
            />

        <EditText
            android:id="@+id/editText2"
            android:layout_width="22dp"
            android:layout_height="match_parent"
            android:layout_weight="0.18"
            android:ems="10"
            android:hint="enter cvv" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/linearLayout3"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignParentLeft="true"
        android:layout_alignRight="@+id/linearLayout2"
        android:layout_below="@+id/linearLayout2"
        android:layout_marginTop="26dp"
        android:orientation="vertical"
        android:background="@drawable/red" >
    </LinearLayout>

    <Spinner
        android:id="@+id/spinner4"
        android:layout_width="15dp"
        android:layout_height="18dp"
        android:layout_alignBottom="@+id/linearLayout3"
        android:layout_alignLeft="@+id/linearLayout3"
        android:layout_alignRight="@+id/linearLayout3"
        android:layout_alignTop="@+id/linearLayout3"
        android:background="@android:drawable/btn_dropdown"
      />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/linearLayout3"
        android:layout_marginTop="18dp"
        android:text="Add Amount" 
        android:background="@drawable/buttonsty"/>
</RelativeLayout>

Pentaho Data Integration SQL connection

I just came across the same issue while trying to query a MySQL Database from Pentaho.

Error connecting to database [Local MySQL DB] : org.pentaho.di.core.exception.KettleDatabaseException: Error occured while trying to connect to the database

Exception while loading class org.gjt.mm.mysql.Driver

Expanding post by @user979331 the solution is:

  1. Download the MySQL Java Connector / Driver that is compatible with your kettle version
  2. Unzip the zip file (in my case it was mysql-connector-java-5.1.31.zip)
  3. copy the .jar file (mysql-connector-java-5.1.31-bin.jar) and paste it in your Lib folder:

    PC: C:\Program Files\pentaho\design-tools\data-integration\lib

    Mac: /Applications/data-integration/lib

Restart Pentaho (Data Integration) and re-test the MySQL Connection.

Additional interesting replies from others that could also help:

How to alias a table in Laravel Eloquent queries (or using Query Builder)?

Laravel supports aliases on tables and columns with AS. Try

$users = DB::table('really_long_table_name AS t')
           ->select('t.id AS uid')
           ->get();

Let's see it in action with an awesome tinker tool

$ php artisan tinker
[1] > Schema::create('really_long_table_name', function($table) {$table->increments('id');});
// NULL
[2] > DB::table('really_long_table_name')->insert(['id' => null]);
// true
[3] > DB::table('really_long_table_name AS t')->select('t.id AS uid')->get();
// array(
//   0 => object(stdClass)(
//     'uid' => '1'
//   )
// )

MySQL - Trigger for updating same table after insert

It seems that you can't do all this in a trigger. According to the documentation:

Within a stored function or trigger, it is not permitted to modify a table that is already being used (for reading or writing) by the statement that invoked the function or trigger.

According to this answer, it seems that you should:

create a stored procedure, that inserts into/Updates the target table, then updates the other row(s), all in a transaction.

With a stored proc you'll manually commit the changes (insert and update). I haven't done this in MySQL, but this post looks like a good example.

How to link to part of the same document in Markdown?

Gitlab uses GitLab Flavored Markdown (GFM)

Here "all Markdown-rendered headers automatically get IDs"

One can use mouse to :

  • move mouse over header
  • move mouse over hover selector which becoms visible to the left from header
  • copy and save link using right mouse click

    For example in README.md file I have header:

## series expansion formula of the Boettcher function

which gives a link :

https://gitlab.com/adammajewski/parameter_external_angle/blob/master/README.md#series-expansion-formula-of-the-boettcher-function

Prefix can be removed so the link here is simply

file#header

which here means:

README.md#series-expansion-formula-of-the-boettcher-function

Now it can be used as :

[series expansion formula of the Boettcher function](README.md#series-expansion-formula-of-the-boettcher-function)

One can also do it manually: replace spaces with hyphen sign.

Live example is here

Append to string variable

var str1 = 'abc';
var str2 = str1+' def'; // str2 is now 'abc def'

Can a unit test project load the target application's app.config file?

I use NUnit and in my project directory I have a copy of my App.Config that I change some configuration (example I redirect to a test database...). You need to have it in the same directory of the tested project and you will be fine.

Check mySQL version on Mac 10.8.5

Or just call mysql command with --version option.

mysql --version

HTML image bottom alignment inside DIV container

Flexboxes can accomplish this by using align-items: flex-end; with display: flex; or display: inline-flex;

div#imageContainer {
    height: 160px;  
    align-items: flex-end;
    display: flex;

    /* This is the default value, so you only need to explicitly set it if it's already being set to something else elsewhere. */
    /*flex-direction: row;*/
}

JSFiddle example

CSS-Tricks has a good guide for flexboxes

Default SecurityProtocol in .NET 4.5

I'm running under .NET 4.5.2, and I wasn't happy with any of these answers. As I'm talking to a system which supports TLS 1.2, and seeing as SSL3, TLS 1.0, and TLS 1.1 are all broken and unsafe for use, I don't want to enable these protocols. Under .NET 4.5.2, the SSL3 and TLS 1.0 protocols are both enabled by default, which I can see in code by inspecting ServicePointManager.SecurityProtocol. Under .NET 4.7, there's the new SystemDefault protocol mode which explicitly hands over selection of the protocol to the OS, where I believe relying on registry or other system configuration settings would be appropriate. That doesn't seem to be supported under .NET 4.5.2 however. In the interests of writing forwards-compatible code, that will keep making the right decisions even when TLS 1.2 is inevitably broken in the future, or when I upgrade to .NET 4.7+ and hand over more responsibility for selecting an appropriate protocol to the OS, I adopted the following code:

SecurityProtocolType securityProtocols = ServicePointManager.SecurityProtocol;
if (securityProtocols.HasFlag(SecurityProtocolType.Ssl3) || securityProtocols.HasFlag(SecurityProtocolType.Tls) || securityProtocols.HasFlag(SecurityProtocolType.Tls11))
{
    securityProtocols &= ~(SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11);
    if (securityProtocols == 0)
    {
        securityProtocols |= SecurityProtocolType.Tls12;
    }
    ServicePointManager.SecurityProtocol = securityProtocols;
}

This code will detect when a known insecure protocol is enabled, and in this case, we'll remove these insecure protocols. If no other explicit protocols remain, we'll then force enable TLS 1.2, as the only known secure protocol supported by .NET at this point in time. This code is forwards compatible, as it will take into consideration new protocol types it doesn't know about being added in the future, and it will also play nice with the new SystemDefault state in .NET 4.7, meaning I won't have to re-visit this code in the future. I'd strongly recommend adopting an approach like this, rather than hard-coding any particular security protocol states unconditionally, otherwise you'll have to recompile and replace your client with a new version in order to upgrade to a new security protocol when TLS 1.2 is inevitably broken, or more likely you'll have to leave the existing insecure protocols turned on for years on your server, making your organisation a target for attacks.

Detect WebBrowser complete page loading

It doesn't seem to trigger DocumentCompleted/Navigated events for external Javascript or CSS files, but it will for iframes. As PK says, compare the WebBrowserDocumentCompletedEventArgs.Url property (I don't have the karma to make a comment yet).

Test if a property is available on a dynamic variable

If you control the type being used as dynamic, couldn't you return a tuple instead of a value for every property access? Something like...

public class DynamicValue<T>
{
    internal DynamicValue(T value, bool exists)
    {
         Value = value;
         Exists = exists;
    }

    T Value { get; private set; }
    bool Exists { get; private set; }
}

Possibly a naive implementation, but if you construct one of these internally each time and return that instead of the actual value, you can check Exists on every property access and then hit Value if it does with value being default(T) (and irrelevant) if it doesn't.

That said, I might be missing some knowledge on how dynamic works and this might not be a workable suggestion.

What is the best way to test for an empty string in Go?

Checking for length is a good answer, but you could also account for an "empty" string that is also only whitespace. Not "technically" empty, but if you care to check:

package main

import (
  "fmt"
  "strings"
)

func main() {
  stringOne := "merpflakes"
  stringTwo := "   "
  stringThree := ""

  if len(strings.TrimSpace(stringOne)) == 0 {
    fmt.Println("String is empty!")
  }

  if len(strings.TrimSpace(stringTwo)) == 0 {
    fmt.Println("String two is empty!")
  }

  if len(stringTwo) == 0 {
    fmt.Println("String two is still empty!")
  }

  if len(strings.TrimSpace(stringThree)) == 0 {
    fmt.Println("String three is empty!")
  }
}

Add Insecure Registry to Docker

For me the solution was to add the registry to here:

/etc/sysconfig/docker-registries

DOCKER_REGISTRIES=''
DOCKER_EXTRA_REGISTRIES='--insecure-registry  b.example.com'

Installing a plain plugin jar in Eclipse 3.5

in Eclipse 4.4.1

  1. copy jar in "C:\eclipse\plugins"
  2. edit file "C:\eclipse\configuration\org.eclipse.equinox.simpleconfigurator\bundles.info"
  3. add jar info. example: com.soft4soft.resort.jdt,2.4.4,file:plugins\com.soft4soft.resort.jdt_2.4.4.jar,4,false
  4. restart Eclipse.

'xmlParseEntityRef: no name' warnings while loading xml into a php file

This is in deed due to characters messing around with the data. Using htmlentities($yourText) worked for me (I had html code inside the xml document). See http://uk3.php.net/htmlentities.

Install Windows Service created in Visual Studio

Yet another catch I ran into: ensure your Installer derived class (typically ProjectInstaller) is at the top of the namespace hierarchy, I tried to use a public class within another public class, but this results in the same old error:

No public installers with the RunInstallerAttribute.Yes attribute could be found

Is it possible to decompile a compiled .pyc file into a .py file?

Install using pip install pycompyle6

pycompyle6 filename.pyc

Performing Breadth First Search recursively

Let v be the starting vertex

Let G be the graph in question

The following is the pseudo code without using queue

Initially label v as visited as you start from v
BFS(G,v)
    for all adjacent vertices w of v in G:
        if vertex w is not visited:
            label w as visited
    for all adjacent vertices w of v in G:
        recursively call BFS(G,w)

Can you animate a height change on a UITableViewCell when selected?

Inputs -

tableView.beginUpdates() tableView.endUpdates() these functions will not call

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {}

But, if you do, tableView.reloadRows(at: [selectedIndexPath! as IndexPath], with: .none)

It will call the func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {} this function.

AmazonS3 putObject with InputStream length example

I've created a library that uses multipart uploads in the background to avoid buffering everything in memory and also doesn't write to disk: https://github.com/alexmojaki/s3-stream-upload

Best way to incorporate Volley (or other library) into Android Studio project

As of today, there is an official Android-hosted copy of Volley available on JCenter:

compile 'com.android.volley:volley:1.0.0'

This was compiled from the AOSP volley source code.

Warning "Do not Access Superglobal $_POST Array Directly" on Netbeans 7.4 for PHP

Here is part of a line in my code that brought the warning up in NetBeans:

$page = (!empty($_GET['p'])) 

After much research and seeing how there are about a bazillion ways to filter this array, I found one that was simple. And my code works and NetBeans is happy:

$p = filter_input(INPUT_GET, 'p');
$page = (!empty($p))

Override valueof() and toString() in Java enum

Try this, but i don't sure that will work every where :)

public enum MyEnum {
    A("Start There"),
    B("Start Here");

    MyEnum(String name) {
        try {
            Field fieldName = getClass().getSuperclass().getDeclaredField("name");
            fieldName.setAccessible(true);
            fieldName.set(this, name);
            fieldName.setAccessible(false);
        } catch (Exception e) {}
    }
}

Sorting hashmap based on keys

TreeMap is your best bet for these kind of sorting (Natural). TreeMap naturally sorts according to the keys.

HashMap does not preserve insertion order nor does it sort the map. LinkedHashMap keeps the insertion order but doesn't sort the map automatically. Only TreeMap in the Map interface sorts the map according to natural order (Numerals first, upper-case alphabet second, lower-case alphabet last).

VB6 IDE cannot load MSCOMCTL.OCX after update KB 2687323

I recently put all my source on a windows 8 32 box. Had the issues loading mscomctl.ocx with existing projects.

I created a new project and add the common control (all). save the project and reloaded it no problem.

when you compare the project headers new vs old the old one uses reference=*\blah blah. I found removing this a replacing it with the Object={blah} sorted out the problem.

What is $@ in Bash?

Yes. Please see the man page of bash ( the first thing you go to ) under Special Parameters

Special Parameters

The shell treats several parameters specially. These parameters may only be referenced; assignment to them is not allowed.

* Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, it expands to a single word with the value of each parameter separated by the first character of the IFS special variable. That is, "$*" is equivalent to "$1c$2c...", where c is the first character of the value of the IFS variable. If IFS is unset, the parameters are separated by spaces. If IFS is null, the parameters are joined without intervening separators.

@ Expands to the positional parameters, starting from one. When the expansion occurs within double quotes, each parameter expands to a separate word. That is, "$@" is equivalent to "$1" "$2" ... If the double-quoted expansion occurs within a word, the expansion of the first parameter is joined with the beginning part of the original word, and the expansion of the last parameter is joined with the last part of the original word. When there are no positional parameters, "$@" and $@ expand to nothing (i.e., they are removed).

How to include file in a bash shell script

In my situation, in order to include color.sh from the same directory in init.sh, I had to do something as follows.

. ./color.sh

Not sure why the ./ and not color.sh directly. The content of color.sh is as follows.

RED=`tput setaf 1`
GREEN=`tput setaf 2`
BLUE=`tput setaf 4`
BOLD=`tput bold`
RESET=`tput sgr0`

Making use of File color.sh does not error but, the color do not display. I have tested this in Ubuntu 18.04 and the Bash version is:

GNU bash, version 4.4.19(1)-release (x86_64-pc-linux-gnu)

Is there a function to make a copy of a PHP array to another?

When you do

$array_x = $array_y;

PHP copies the array, so I'm not sure how you would have gotten burned. For your case,

global $foo;
$foo = $obj->bar;

should work fine.

In order to get burned, I would think you'd either have to have been using references or expecting objects inside the arrays to be cloned.

CSS border less than 1px

A pixel is the smallest unit value to render something with, but you can trick thickness with optical illusions by modifying colors (the eye can only see up to a certain resolution too).

Here is a test to prove this point:

_x000D_
_x000D_
div { border-color: blue; border-style: solid; margin: 2px; }

div.b1 { border-width: 1px; }
div.b2 { border-width: 0.1em; }
div.b3 { border-width: 0.01em; }
div.b4 { border-width: 1px; border-color: rgb(160,160,255); }
_x000D_
<div class="b1">Some text</div>
<div class="b2">Some text</div>
<div class="b3">Some text</div>
<div class="b4">Some text</div>
_x000D_
_x000D_
_x000D_

Output

enter image description here

Which gives the illusion that the last DIV has a smaller border width, because the blue border blends more with the white background.


Edit: Alternate solution

Alpha values may also be used to simulate the same effect, without the need to calculate and manipulate RGB values.

_x000D_
_x000D_
.container {
  border-style: solid;
  border-width: 1px;
  
  margin-bottom: 10px;
}

.border-100 { border-color: rgba(0,0,255,1); }
.border-75 { border-color: rgba(0,0,255,0.75); }
.border-50 { border-color: rgba(0,0,255,0.5); }
.border-25 { border-color: rgba(0,0,255,0.25); }
_x000D_
<div class="container border-100">Container 1 (alpha = 1)</div>
<div class="container border-75">Container 2 (alpha = 0.75)</div>
<div class="container border-50">Container 3 (alpha = 0.5)</div>
<div class="container border-25">Container 4 (alpha = 0.25)</div>
_x000D_
_x000D_
_x000D_

One DbContext per web request... why?

I'm pretty certain it is because the DbContext is not at all thread safe. So sharing the thing is never a good idea.