Programs & Examples On #Sdhc

Git commit with no commit message

--allow-empty-message -m '' (and -m "") fail in Git 2.29.2 on PowerShell:

error: switch `m' requires a value

(oddly enough, with a backtick on one side and a single quote on the other)


The following works consistently in Linux, PowerShell, and Command Prompt:

git commit --allow-empty-message --no-edit

The --no-edit bit does the trick, as it prevents the editor from launching.

I find this form more explicit and a bit less hacky than forcing an empty message with -m ''.

JavaScript Chart.js - Custom data formatting to display on tooltip

This is what my final options section looks like for chart.js version 2.8.0.

        options: {
        legend: {
            display: false //Have this or else legend will display as undefined
        },
        scales: {
            //This will show money for y-axis labels with format of $xx.xx
            yAxes: [{
              ticks: {
                beginAtZero: true,
                callback: function(value) {
                    return (new Intl.NumberFormat('en-US', {
                        style: 'currency',
                        currency: 'USD',
                    })).format(value);
                }
              }
            }]
        },
        //This will show money in tooltip with format of $xx.xx
        tooltips: {
            callbacks: {
                label: function (tooltipItem) {
                    return (new Intl.NumberFormat('en-US', {
                        style: 'currency',
                        currency: 'USD',
                    })).format(tooltipItem.value);
                }
            }
        }
    }

I wanted to show money values for both the y-axis and the tooltip values that show up when you hover over them. This works to show $49.99 and values with zero cents (ex: $50.00)

Explaining Apache ZooKeeper

My approach to understand zookeeper was, to play around with the CLI client. as described in Getting Started Guide and Command line interface

From this I learned that zookeeper's surface looks very similar to a filesystem and clients can create and delete objects and read or write data.

Example CLI commands

create /myfirstnode mydata
ls /
get /myfirstnode
delete /myfirstnode

Try yourself

How to spin up a zookeper environment within minutes on docker for windows, linux or mac:

One time set up:

docker network create dn

Run server in a terminal window:

docker run --network dn --name zook -d zookeeper
docker logs -f zookeeper

Run client in a second terminal window:

docker run -it --rm --network dn zookeeper zkCli.sh -server zook

See also documentation of image on dockerhub

How to log request and response body with Retrofit-Android?

Update for Retrofit 2.0.0-beta3

Now you have to use okhttp3 with builder. Also the old interceptor will not work. This response is tailored for Android.

Here's a quick copy paste for you with the new stuff.

1. Modify your gradle file to

  compile 'com.squareup.retrofit2:retrofit:2.0.0-beta3'
  compile "com.squareup.retrofit2:converter-gson:2.0.0-beta3"
  compile "com.squareup.retrofit2:adapter-rxjava:2.0.0-beta3"
  compile 'com.squareup.okhttp3:logging-interceptor:3.0.1'

2. Check this sample code:

with the new imports. You can remove Rx if you don't use it, also remove what you don't use.

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.GsonConverterFactory;
import retrofit2.Retrofit;
import retrofit2.RxJavaCallAdapterFactory;
import retrofit2.http.GET;
import retrofit2.http.Query;
import rx.Observable;

public interface APIService {

  String ENDPOINT = "http://api.openweathermap.org";
  String API_KEY = "2de143494c0b2xxxx0e0";

  @GET("/data/2.5/weather?appid=" + API_KEY) Observable<WeatherPojo> getWeatherForLatLon(@Query("lat") double lat, @Query("lng") double lng, @Query("units") String units);


  class Factory {

    public static APIService create(Context context) {

      OkHttpClient.Builder builder = new OkHttpClient().newBuilder();
      builder.readTimeout(10, TimeUnit.SECONDS);
      builder.connectTimeout(5, TimeUnit.SECONDS);

      if (BuildConfig.DEBUG) {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BASIC);
        builder.addInterceptor(interceptor);
      }

      //Extra Headers

      //builder.addNetworkInterceptor().add(chain -> {
      //  Request request = chain.request().newBuilder().addHeader("Authorization", authToken).build();
      //  return chain.proceed(request);
      //});

      builder.addInterceptor(new UnauthorisedInterceptor(context));
      OkHttpClient client = builder.build();

      Retrofit retrofit =
          new Retrofit.Builder().baseUrl(APIService.ENDPOINT).client(client).addConverterFactory(GsonConverterFactory.create()).addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();

      return retrofit.create(APIService.class);
    }
  }
}

Bonus

I know it's offtopic but I find it cool.

In case there's an http error code of unauthorized, here is an interceptor. I use eventbus for transmitting the event.

import android.content.Context;
import android.os.Handler;
import android.os.Looper;
import com.androidadvance.ultimateandroidtemplaterx.BaseApplication;
import com.androidadvance.ultimateandroidtemplaterx.events.AuthenticationErrorEvent;

import de.greenrobot.event.EventBus;
import java.io.IOException;
import javax.inject.Inject;
import okhttp3.Interceptor;
import okhttp3.Response;

public class UnauthorisedInterceptor implements Interceptor {

  @Inject EventBus eventBus;

  public UnauthorisedInterceptor(Context context) {
    BaseApplication.get(context).getApplicationComponent().inject(this);
  }

  @Override public Response intercept(Chain chain) throws IOException {
    Response response = chain.proceed(chain.request());
    if (response.code() == 401) {
      new Handler(Looper.getMainLooper()).post(() -> eventBus.post(new AuthenticationErrorEvent()));
    }
    return response;
  }
}

code take from https://github.com/AndreiD/UltimateAndroidTemplateRx (my project).

Split string into individual words Java

A regex can also be used to split words.

\w can be used to match word characters ([A-Za-z0-9_]), so that punctuation is removed from the results:

String s = "I want to walk my dog, and why not?";
Pattern pattern = Pattern.compile("\\w+");
Matcher matcher = pattern.matcher(s);
while (matcher.find()) {
    System.out.println(matcher.group());
}

Outputs:

I
want
to
walk
my
dog
and
why
not

See Java API documentation for Pattern

How to sum a list of integers with java streams?

Most of the aspects are covered. But there could be a requirement to find the aggregation of other data types apart from Integer, Long(for which specialized stream support is already present). For e.g. stram with BigInteger For such a type we can use reduce operation like

list.stream().reduce((bigInteger1, bigInteger2) -> bigInteger1.add(bigInteger2))

Android - Get value from HashMap

HashMap<String, String> meMap = new HashMap<String, String>();
meMap.put("Color1", "Red");
meMap.put("Color2", "Blue");
meMap.put("Color3", "Green");
meMap.put("Color4", "White");

Iterator myVeryOwnIterator = meMap.values().iterator();
while(myVeryOwnIterator.hasNext()) {
    Toast.makeText(getBaseContext(), myVeryOwnIterator.next(), Toast.LENGTH_SHORT).show();
}

Nuget connection attempt failed "Unable to load the service index for source"

I was trying to add an Azure Artifacts NuGet source.

I followed Microsoft's instructions here, with one critical oversight.

I forgot to replace /v3/index.json with /v2.

enter image description here

Regular expression that matches valid IPv6 addresses

If you use Perl try Net::IPv6Addr

use Net::IPv6Addr;

if( defined Net::IPv6Addr::is_ipv6($ip_address) ){
  print "Looks like an ipv6 address\n";
}

NetAddr::IP

use NetAddr::IP;

my $obj = NetAddr::IP->new6($ip_address);

Validate::IP

use Validate::IP qw'is_ipv6';

if( is_ipv6($ip_address) ){
  print "Looks like an ipv6 address\n";
}

Proper use of mutexes in Python

I would like to improve answer from chris-b a little bit more.

See below for my code:

from threading import Thread, Lock
import threading
mutex = Lock()


def processData(data, thread_safe):
    if thread_safe:
        mutex.acquire()
    try:
        thread_id = threading.get_ident()
        print('\nProcessing data:', data, "ThreadId:", thread_id)
    finally:
        if thread_safe:
            mutex.release()


counter = 0
max_run = 100
thread_safe = False
while True:
    some_data = counter        
    t = Thread(target=processData, args=(some_data, thread_safe))
    t.start()
    counter = counter + 1
    if counter >= max_run:
        break

In your first run if you set thread_safe = False in while loop, mutex will not be used, and threads will step over each others in print method as below;

Not Thread safe

but, if you set thread_safe = True and run it, you will see all the output comes perfectly fine;

Thread safe

hope this helps.

In java how to get substring from a string till a character c?

look at String.indexOf and String.substring.

Make sure you check for -1 for indexOf.

Returning a pointer to a vector element in c++

Return the address of the thing pointed to by the iterator:

&(*iterator)

Edit: To clear up some confusion:

vector <int> vec;          // a global vector of ints

void f() {
   vec.push_back( 1 );    // add to the global vector
   vector <int>::iterator it = vec.begin();
   * it = 2;              // change what was 1 to 2
   int * p = &(*it);      // get pointer to first element
   * p = 3;               // change what was 2 to 3
}

No need for vectors of pointers or dynamic allocation.

What could cause an error related to npm not being able to find a file? No contents in my node_modules subfolder. Why is that?

I had the SAME issue today and it was driving me nuts!!! What I had done was upgrade to node 8.10 and upgrade my NPM to the latest I uninstalled angular CLI

npm uninstall -g angular-cli
npm uninstall --save-dev angular-cli

I then verified my Cache from NPM if it wasn't up to date I cleaned it and ran the install again if npm version is < 5 then use npm cache clean --force

npm install -g @angular/cli@latest

and created a new project file and create a new angular project.

How do I set the classpath in NetBeans?

Maven

The Answer by Bhesh Gurung is correct… unless your NetBeans project is Maven based.

Dependency

Under Maven, you add a "dependency". A dependency is a description of a library (its name & version number) you want to use from your code.

Or a dependency could be a description of a library which another library needs ("depends on"). Maven automatically handles this chain, libraries that need other libraries that then need other libraries and so on. For the mathematical-minded, perhaps the phrase "Maven resolves the transitive dependencies" makes sense.

Repository

Maven gets this related-ness information, and the libraries themselves from a Maven repository. A repository is basically an online database and collection of download files (the dependency library).

Easy to Use

Adding a dependency to a Maven-based project is really quite easy. That is the whole point to Maven, to make managing dependent libraries easy and to make building them into your project easy. To get started with adding a dependency, see this Question, Adding dependencies in Maven Netbeans and my Answer with screenshot.

enter image description here

How to instantiate a javascript class in another js file?

It is saying the value is undefined because it is a constructor function, not a class with a constructor. In order to use it, you would need to use Customer() or customer().

First, you need to load file1.js before file2.js, like slebetman said:

<script defer src="file1.js" type="module"></script>
<script defer src="file2.js" type="module"></script>

Then, you could change your file1.js as follows:

export default class Customer(){
    constructor(){
        this.name="Jhon";
        this.getName=function(){
            return this.name;
        };
    }
}

And the file2.js as follows:

import { Customer } from "./file1";
var customer=new Customer();

Please correct me if I am wrong.

what does -zxvf mean in tar -zxvf <filename>?

Instead of wading through the description of all the options, you can jump to 3.4.3 Short Options Cross Reference under the info tar command.

x means --extract. v means --verbose. f means --file. z means --gzip. You can combine one-letter arguments together, and f takes an argument, the filename. There is something you have to watch out for:

Short options' letters may be clumped together, but you are not required to do this (as compared to old options; see below). When short options are clumped as a set, use one (single) dash for them all, e.g., ''tar' -cvf'. Only the last option in such a set is allowed to have an argument(1).


This old way of writing 'tar' options can surprise even experienced users. For example, the two commands:

 tar cfz archive.tar.gz file
 tar -cfz archive.tar.gz file

are quite different. The first example uses 'archive.tar.gz' as the value for option 'f' and recognizes the option 'z'. The second example, however, uses 'z' as the value for option 'f' -- probably not what was intended.

What "wmic bios get serialnumber" actually retrieves?

wmic bios get serialnumber     

if run from a command line (start-run should also do the trick) prints out on screen the Serial Number of the product,
(for example in a toshiba laptop it would print out the serial number of the laptop.
with this serial number you can then identify your laptop model if you need ,from the makers service website-usually..:):)

I had to do exactly that.:):)

Unable to cast object of type 'System.DBNull' to type 'System.String`

I suppose you can do it like this:

string accountNumber = DBSqlHelperFactory.ExecuteScalar(...) as string;

If accountNumber is null it means it was DBNull not string :)

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

From the Python docs, set the PATH like you did as above.

You should arrange for Python’s installation directory to be added to the PATH of every command window as it starts. If you installed Python fairly recently then the command dir C:\py* will probably tell you where it is installed; the usual location is something like C:\Python27. Otherwise you will be reduced to a search of your whole disk

Use Tools ? Find or hit the Search button and look for “python.exe”. Supposing you discover that Python is installed in the C:\Python27 directory (the default at the time of writing), you should make sure that entering the command

Then execute the Python command using the full path name to make sure that works.

if (boolean == false) vs. if (!boolean)

Note: With ConcurrentMap you can use the more efficient

values.putIfAbsent(NoteColumns.CREATED_DATE, now);

I prefer the less verbose solution and avoid methods like IsTrue or IsFalse or their like.

How to make a great R reproducible example

(Here's my advice from How to write a reproducible example. I've tried to make it short but sweet).

How to write a reproducible example

You are most likely to get good help with your R problem if you provide a reproducible example. A reproducible example allows someone else to recreate your problem by just copying and pasting R code.

You need to include four things to make your example reproducible: required packages, data, code, and a description of your R environment.

  • Packages should be loaded at the top of the script, so it's easy to see which ones the example needs.

  • The easiest way to include data in an email or Stack Overflow question is to use dput() to generate the R code to recreate it. For example, to recreate the mtcars dataset in R, I'd perform the following steps:

    1. Run dput(mtcars) in R
    2. Copy the output
    3. In my reproducible script, type mtcars <- then paste.
  • Spend a little bit of time ensuring that your code is easy for others to read:

    • Make sure you've used spaces and your variable names are concise, but informative

    • Use comments to indicate where your problem lies

    • Do your best to remove everything that is not related to the problem.
      The shorter your code is, the easier it is to understand.

  • Include the output of sessionInfo() in a comment in your code. This summarises your R environment and makes it easy to check if you're using an out-of-date package.

You can check you have actually made a reproducible example by starting up a fresh R session and pasting your script in.

Before putting all of your code in an email, consider putting it on Gist github. It will give your code nice syntax highlighting, and you don't have to worry about anything getting mangled by the email system.

Has an event handler already been added?

i agree with alf's answer,but little modification to it is,, to use,

           try
            {
                control_name.Click -= event_Click;
                main_browser.Document.Click += Document_Click;
            }
            catch(Exception exce)
            {
                main_browser.Document.Click += Document_Click;
            }

Allowing Java to use an untrusted certificate for SSL/HTTPS connection

Another option is to get a ".pem" (public key) file for that particular server, and install it locally into the heart of your JRE's "cacerts" file (use the keytool helper application), then it will be able to download from that server without complaint, without compromising the entire SSL structure of your running JVM and enabling download from other unknown cert servers...

Java heap terminology: young, old and permanent generations?

This seems like a common misunderstanding. In Oracle's JVM, the permanent generation is not part of the heap. It's a separate space for class definitions and related data. In Java 6 and earlier, interned strings were also stored in the permanent generation. In Java 7, interned strings are stored in the main object heap.

Here is a good post on permanent generation.

I like the descriptions given for each space in Oracle's guide on JConsole:

For the HotSpot Java VM, the memory pools for serial garbage collection are the following.

  • Eden Space (heap): The pool from which memory is initially allocated for most objects.
  • Survivor Space (heap): The pool containing objects that have survived the garbage collection of the Eden space.
  • Tenured Generation (heap): The pool containing objects that have existed for some time in the survivor space.
  • Permanent Generation (non-heap): The pool containing all the reflective data of the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.
  • Code Cache (non-heap): The HotSpot Java VM also includes a code cache, containing memory that is used for compilation and storage of native code.

Java uses generational garbage collection. This means that if you have an object foo (which is an instance of some class), the more garbage collection events it survives (if there are still references to it), the further it gets promoted. It starts in the young generation (which itself is divided into multiple spaces - Eden and Survivor) and would eventually end up in the tenured generation if it survived long enough.

Declaring & Setting Variables in a Select Statement

From the searching I've done it appears you can not declare and set variables like this in Select statements. Is this right or am I missing something?

Within Oracle PL/SQL and SQL are two separate languages with two separate engines. You can embed SQL DML within PL/SQL, and that will get you variables. Such as the following anonymous PL/SQL block. Note the / at the end is not part of PL/SQL, but tells SQL*Plus to send the preceding block.

declare 
    v_Date1 date := to_date('03-AUG-2010', 'DD-Mon-YYYY');
    v_Count number;
begin
    select count(*) into v_Count
    from Usage
    where UseTime > v_Date1;
    dbms_output.put_line(v_Count);
end;
/

The problem is that a block that is equivalent to your T-SQL code will not work:

SQL> declare 
  2      v_Date1 date := to_date('03-AUG-2010', 'DD-Mon-YYYY');
  3  begin
  4      select VisualId
  5      from Usage
  6      where UseTime > v_Date1;
  7  end;
  8  /
    select VisualId
    *
ERROR at line 4:
ORA-06550: line 4, column 5:
PLS-00428: an INTO clause is expected in this SELECT statement

To pass the results of a query out of an PL/SQL, either an anonymous block, stored procedure or stored function, a cursor must be declared, opened and then returned to the calling program. (Beyond the scope of answering this question. EDIT: see Get resultset from oracle stored procedure)

The client tool that connects to the database may have it's own bind variables. In SQL*Plus:

SQL> -- SQL*Plus does not all date type in this context
SQL> -- So using varchar2 to hold text
SQL> variable v_Date1 varchar2(20)
SQL>
SQL> -- use PL/SQL to set the value of the bind variable
SQL> exec :v_Date1 := '02-Aug-2010';

PL/SQL procedure successfully completed.

SQL> -- Converting to a date, since the variable is not yet a date.
SQL> -- Note the use of colon, this tells SQL*Plus that v_Date1
SQL> -- is a bind variable.
SQL> select VisualId
  2  from Usage
  3  where UseTime > to_char(:v_Date1, 'DD-Mon-YYYY');

no rows selected

Note the above is in SQLPlus, may not (probably won't) work in Toad PL/SQL developer, etc. The lines starting with variable and exec are SQLPlus commands. They are not SQL or PL/SQL commands. No rows selected because the table is empty.

Creating a new dictionary in Python

You can do this

x = {}
x['a'] = 1

Spring Boot Rest Controller how to return different HTTP status codes?

There are several options you can use. Quite good way is to use exceptions and class for handling called @ControllerAdvice:

@ControllerAdvice
class GlobalControllerExceptionHandler {
    @ResponseStatus(HttpStatus.CONFLICT)  // 409
    @ExceptionHandler(DataIntegrityViolationException.class)
    public void handleConflict() {
        // Nothing to do
    }
}

Also you can pass HttpServletResponse to controller method and just set response code:

public RestModel create(@RequestBody String data, HttpServletResponse response) {
    // response committed...
    response.setStatus(HttpServletResponse.SC_ACCEPTED);
}

Please refer to the this great blog post for details: Exception Handling in Spring MVC


NOTE

In Spring MVC using @ResponseBody annotation is redundant - it's already included in @RestController annotation.

How do I iterate through children elements of a div using jQuery?

It is also possible to iterate through all elements within a specific context, no mattter how deeply nested they are:

$('input', $('#mydiv')).each(function () {
    console.log($(this)); //log every element found to console output
});

The second parameter $('#mydiv') which is passed to the jQuery 'input' Selector is the context. In this case the each() clause will iterate through all input elements within the #mydiv container, even if they are not direct children of #mydiv.

Bootstrap select dropdown list placeholder

<option value="" defaultValue disabled> Something </option>

you can replace defaultValue with selected but that would give warning.

String.contains in Java

I will answer your question using a math analogy:

In this instance, the number 0 will represent no value. If you pick a random number, say 15, how many times can 0 be subtracted from 15? Infinite times because 0 has no value, thus you are taking nothing out of 15. Do you have difficulty accepting that 15 - 0 = 15 instead of ERROR? So if we switch this analogy back to Java coding, the String "" represents no value. Pick a random string, say "hello world", how many times can "" be subtracted from "hello world"?

Parsing JSON in Spring MVC using Jackson JSON

The whole point of using a mapping technology like Jackson is that you can use Objects (you don't have to parse the JSON yourself).

Define a Java class that resembles the JSON you will be expecting.

e.g. this JSON:

{
"foo" : ["abc","one","two","three"],
"bar" : "true",
"baz" : "1"
}

could be mapped to this class:

public class Fizzle{
    private List<String> foo;
    private boolean bar;
    private int baz;
    // getters and setters omitted
}

Now if you have a Controller method like this:

@RequestMapping("somepath")
@ResponseBody
public Fozzle doSomeThing(@RequestBody Fizzle input){
    return new Fozzle(input);
}

and you pass in the JSON from above, Jackson will automatically create a Fizzle object for you, and it will serialize a JSON view of the returned Object out to the response with mime type application/json.

For a full working example see this previous answer of mine.

How do I do a not equal in Django queryset filtering?

Django-model-values (disclosure: author) provides an implementation of the NotEqual lookup, as in this answer. It also provides syntactic support for it:

from model_values import F
Model.objects.exclude(F.x != 5, a=True)

JQuery Event for user pressing enter in a textbox?

You can wire up your own custom event

$('textarea').bind("enterKey",function(e){
   //do stuff here
});
$('textarea').keyup(function(e){
    if(e.keyCode == 13)
    {
        $(this).trigger("enterKey");
    }
});

http://jsfiddle.net/x7HVQ/

unknown type name 'uint8_t', MinGW

I had to include "PROJECT_NAME/osdep.h" and that includes the os specific configurations.

I would look in other files using the types you are interested in and find where/how they are defined (by looking at includes).

How do I use reflection to call a generic method?

Nobody provided the "classic Reflection" solution, so here is a complete code example:

using System;
using System.Collections;
using System.Collections.Generic;

namespace DictionaryRuntime
{
    public class DynamicDictionaryFactory
    {
        /// <summary>
        /// Factory to create dynamically a generic Dictionary.
        /// </summary>
        public IDictionary CreateDynamicGenericInstance(Type keyType, Type valueType)
        {
            //Creating the Dictionary.
            Type typeDict = typeof(Dictionary<,>);

            //Creating KeyValue Type for Dictionary.
            Type[] typeArgs = { keyType, valueType };

            //Passing the Type and create Dictionary Type.
            Type genericType = typeDict.MakeGenericType(typeArgs);

            //Creating Instance for Dictionary<K,T>.
            IDictionary d = Activator.CreateInstance(genericType) as IDictionary;

            return d;

        }
    }
}

The above DynamicDictionaryFactory class has a method

CreateDynamicGenericInstance(Type keyType, Type valueType)

and it creates and returns an IDictionary instance, the types of whose keys and values are exactly the specified on the call keyType and valueType.

Here is a complete example how to call this method to instantiate and use a Dictionary<String, int> :

using System;
using System.Collections.Generic;

namespace DynamicDictionary
{
    class Test
    {
        static void Main(string[] args)
        {
            var factory = new DictionaryRuntime.DynamicDictionaryFactory();
            var dict = factory.CreateDynamicGenericInstance(typeof(String), typeof(int));

            var typedDict = dict as Dictionary<String, int>;

            if (typedDict != null)
            {
                Console.WriteLine("Dictionary<String, int>");

                typedDict.Add("One", 1);
                typedDict.Add("Two", 2);
                typedDict.Add("Three", 3);

                foreach(var kvp in typedDict)
                {
                    Console.WriteLine("\"" + kvp.Key + "\": " + kvp.Value);
                }
            }
            else
                Console.WriteLine("null");
        }
    }
}

When the above console application is executed, we get the correct, expected result:

Dictionary<String, int>
"One": 1
"Two": 2
"Three": 3

The requested URL /about was not found on this server

That's not a typical Wordpress rewrite block. This is:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

See http://codex.wordpress.org/Using_Permalinks#Where.27s_my_.htaccess_file.3F

Where's my .htaccess file? WordPress's index.php and .htaccess files should be together in the directory indicated by the Site address (URL) setting on your General Options page. Since the name of the file begins with a dot, the file may not be visible through an FTP client unless you change the preferences of the FTP tool to show all files, including the hidden files. Some hosts (e.g. Godaddy) may not show or allow you to edit .htaccess if you install WordPress through the Godaddy Hosting Connection installation.

Creating and editing (.htaccess) If you do not already have a .htaccess file, create one. If you have shell or ssh access to the server, a simple touch .htaccess command will create the file. If you are using FTP to transfer files, create a file on your local computer, call it 1.htaccess, upload it to the root of your WordPress folder, and then rename it to .htaccess.

You can edit the .htaccess file by FTP, shell, or (possibly) your host's control panel.

The easiest and fastest thing to do it reset your permalinks in Dashboard>>Settings>>Permalinks and make sure .htaccess is writable so WordPress can write the rules itself.

And: are you aware you are calling index.cgi as your default document rather than index.php? That's wrong. Remove index.cgi. Or try removing the whole line, too, because defining a default doc on your server may not be needed.

Count all values in a matrix greater than a value

Here's a variant that uses fancy indexing and has the actual values as an intermediate:

p31 = numpy.asarray(o31)
values = p31[p31<200]
za = len(values)

Remove duplicated rows

For people who have come here to look for a general answer for duplicate row removal, use !duplicated():

a <- c(rep("A", 3), rep("B", 3), rep("C",2))
b <- c(1,1,2,4,1,1,2,2)
df <-data.frame(a,b)

duplicated(df)
[1] FALSE  TRUE FALSE FALSE FALSE  TRUE FALSE  TRUE

> df[duplicated(df), ]
  a b
2 A 1
6 B 1
8 C 2

> df[!duplicated(df), ]
  a b
1 A 1
3 A 2
4 B 4
5 B 1
7 C 2

Answer from: Removing duplicated rows from R data frame

What are database normal forms and can you give examples?

Here's a quick, admittedly butchered response, but in a sentence:

1NF : Your table is organized as an unordered set of data, and there are no repeating columns.

2NF: You don't repeat data in one column of your table because of another column.

3NF: Every column in your table relates only to your table's key -- you wouldn't have a column in a table that describes another column in your table which isn't the key.

For more detail, see wikipedia...

How do I access store state in React Redux?

Import connect from react-redux and use it to connect the component with the state connect(mapStates,mapDispatch)(component)

import React from "react";
import { connect } from "react-redux";


const MyComponent = (props) => {
    return (
      <div>
        <h1>{props.title}</h1>
      </div>
    );
  }
}

Finally you need to map the states to the props to access them with this.props

const mapStateToProps = state => {
  return {
    title: state.title
  };
};
export default connect(mapStateToProps)(MyComponent);

Only the states that you map will be accessible via props

Check out this answer: https://stackoverflow.com/a/36214059/4040563

For further reading : https://medium.com/@atomarranger/redux-mapstatetoprops-and-mapdispatchtoprops-shorthand-67d6cd78f132

How to override Bootstrap's Panel heading background color?

You can simply add an id attribute to the panel. Like this

<div class="panel-heading" id="mypanelId">Hello world </div>

Then in your custom CSS file:

#mypanelId{
    background-image: none;
    background: rgba(22, 20, 100, 0.8);
    color: white;
     }

How to force a hover state with jQuery?

You will have to use a class, but don't worry, it's pretty simple. First we'll assign your :hover rules to not only apply to physically-hovered links, but also to links that have the classname hovered.

a:hover, a.hovered { color: #ccff00; }

Next, when you click #btn, we'll toggle the .hovered class on the #link.

$("#btn").click(function() {
   $("#link").toggleClass("hovered");
});

If the link has the class already, it will be removed. If it doesn't have the class, it will be added.

SQL DATEPART(dw,date) need monday = 1 and sunday = 7

I think this could work:

  select
    case when datepart(dw,[Date]) = 1 then 7 else DATEPART(DW,[Date])-1 end as WeekDay

JQuery add class to parent element

$(this.parentNode).addClass('newClass');

Why is a "GRANT USAGE" created the first time I grant a user privileges?

In addition mysql passwords when not using the IDENTIFIED BY clause, may be blank values, if non-blank, they may be encrypted. But yes USAGE is used to modify an account by granting simple resource limiters such as MAX_QUERIES_PER_HOUR, again this can be specified by also using the WITH clause, in conjuction with GRANT USAGE(no privileges added) or GRANT ALL, you can also specify GRANT USAGE at the global level, database level, table level,etc....

What are the benefits to marking a field as `readonly` in C#?

readonly can be initialized at declaration or get its value from the constructor only. Unlike const it has to be initialized and declare at the same time. readonly has everything const has, plus constructor initialization

code https://repl.it/HvRU/1

using System;

class MainClass {
    public static void Main (string[] args) {

        Console.WriteLine(new Test().c);
        Console.WriteLine(new Test("Constructor").c);
        Console.WriteLine(new Test().ChangeC()); //Error A readonly field 
        // `MainClass.Test.c' cannot be assigned to (except in a constructor or a 
        // variable initializer)
    }


    public class Test {
        public readonly string c = "Hello World";
        public Test() {

        }

        public Test(string val) {
          c = val;
        }

        public string ChangeC() {
            c = "Method";
            return c ;
        }
    }
}

How to make a deep copy of Java ArrayList

Cloning the objects before adding them. For example, instead of newList.addAll(oldList);

for(Person p : oldList) {
    newList.add(p.clone());
}

Assuming clone is correctly overriden inPerson.

How to select the first element of a set with JSTL?

Using ${mySet.toArray[0]} does not work.

I do not think it is possible without having forEach loop at least one iteration.

Property 'value' does not exist on type EventTarget in TypeScript

Passing HTMLInputElement as a generic to the event type should work too:

onUpdatingServerName(event: React.ChangeEvent<HTMLInputElement>) {
  console.log(event);
  this.newserverName = event.target.value;
}

Threads vs Processes in Linux

For most cases i would prefer processes over threads. threads can be useful when you have a relatively smaller task (process overhead >> time taken by each divided task unit) and there is a need of memory sharing between them. Think a large array. Also (offtopic), note that if your CPU utilization is 100 percent or close to it, there is going to be no benefit out of multithreading or processing. (in fact it will worsen)

Prevent HTML5 video from being downloaded (right-click saved)?

+1 simple and cross-browser way: You can also put transparent picture over the video with css z-index and opacity. So users will see "save picture as" instead of "save video" in context menu.

How to remove trailing whitespace in code, using another script?

Save as fix_whitespace.py:

#!/usr/bin/env python
"""
Fix trailing whitespace and line endings (to Unix) in a file.
Usage: python fix_whitespace.py foo.py
"""

import os
import sys


def main():
    """ Parse arguments, then fix whitespace in the given file """
    if len(sys.argv) == 2:
        fname = sys.argv[1]
        if not os.path.exists(fname):
            print("Python file not found: %s" % sys.argv[1])
            sys.exit(1)
    else:
        print("Invalid arguments. Usage: python fix_whitespace.py foo.py")
        sys.exit(1)
    fix_whitespace(fname)


def fix_whitespace(fname):
    """ Fix whitespace in a file """
    with open(fname, "rb") as fo:
        original_contents = fo.read()
    # "rU" Universal line endings to Unix
    with open(fname, "rU") as fo:
        contents = fo.read()
    lines = contents.split("\n")
    fixed = 0
    for k, line in enumerate(lines):
        new_line = line.rstrip()
        if len(line) != len(new_line):
            lines[k] = new_line
            fixed += 1
    with open(fname, "wb") as fo:
        fo.write("\n".join(lines))
    if fixed or contents != original_contents:
        print("************* %s" % os.path.basename(fname))
    if fixed:
        slines = "lines" if fixed > 1 else "line"
        print("Fixed trailing whitespace on %d %s" \
              % (fixed, slines))
    if contents != original_contents:
        print("Fixed line endings to Unix (\\n)")


if __name__ == "__main__":
    main()

How to check if the given string is palindrome?

Erlang is awesome

palindrome(L) -> palindrome(L,[]).

palindrome([],_) -> false;
palindrome([_|[]],[]) -> true;
palindrome([_|L],L) -> true;
palindrome(L,L) -> true;
palindrome([H|T], Acc) -> palindrome(T, [H|Acc]).

Remove Duplicates from range of cells in excel vba

To remove duplicates from a single column

 Sub removeDuplicate()
 'removeDuplicate Macro
 Columns("A:A").Select
 ActiveSheet.Range("$A$1:$A$117").RemoveDuplicates Columns:=Array(1), _ 
 Header:=xlNo 
 Range("A1").Select
 End Sub

if you have header then use Header:=xlYes

Increase your range as per your requirement.
you can make it to 1000 like this :

ActiveSheet.Range("$A$1:$A$1000")

More info here here

How can I get System variable value in Java?

Use the System.getenv(String) method, passing the name of the variable to read.

Binary search (bisection) in Python

This one is:

  • not recursive (which makes it more memory-efficient than most recursive approaches)
  • actually working
  • fast since it runs without any unnecessary if's and conditions
  • based on a mathematical assertion that the floor of (low + high)/2 is always smaller than high where low is the lower limit and high is the upper limit.

def binsearch(t, key, low = 0, high = len(t) - 1):
    # bisecting the range
    while low < high:
        mid = (low + high)//2
        if t[mid] < key:
            low = mid + 1
        else:
            high = mid
    # at this point 'low' should point at the place
    # where the value of 'key' is possibly stored.
    return low if t[low] == key else -1

How can I insert vertical blank space into an html document?

While the above answers are probably best for this situation, if you just want to do a one-off and don't want to bother with modifying other files, you can in-line the CSS.

<p style="margin-bottom:3cm;">This is the first question?</p>

How to layout multiple panels on a jFrame? (java)

You'll want to use a number of layout managers to help you achieve the basic results you want.

Check out A Visual Guide to Layout Managers for a comparision.

You could use a GridBagLayout but that's one of the most complex (and powerful) layout managers available in the JDK.

You could use a series of compound layout managers instead.

I'd place the graphics component and text area on a single JPanel, using a BorderLayout, with the graphics component in the CENTER and the text area in the SOUTH position.

I'd place the text field and button on a separate JPanel using a GridBagLayout (because it's the simplest I can think of to achieve the over result you want)

I'd place these two panels onto a third, master, panel, using a BorderLayout, with the first panel in the CENTER and the second at the SOUTH position.

But that's me

Laravel 5.2 Missing required parameters for [Route: user.profile] [URI: user/{nickname}/profile]

My Solution in laravel 5.2

{{ Form::open(['route' => ['votes.submit', $video->id],  'method' => 'POST']) }}
    <button type="submit" class="btn btn-primary">
        <span class="glyphicon glyphicon-thumbs-up"></span> Votar
    </button>
{{ Form::close() }}

My Routes File (under middleware)

Route::post('votar/{id}', [
    'as' => 'votes.submit',
    'uses' => 'VotesController@submit'
]);

Route::delete('votar/{id}', [
    'as' => 'votes.destroy',
    'uses' => 'VotesController@destroy'
]);

Blur or dim background when Android PopupWindow active

ok, so i follow uhmdown's answer for dimming background activity when pop window is open. But it creates problem for me. it was dimming activity and include popup window (means dimmed-black layered on both activity and popup also, it can not be separate them).

so i tried this way,

create an dimming_black.xml file for dimming effect,

 <?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#33000000" />
</shape>

And add as background in FrameLayout as root xml tag, also put my other controls in LinearLayout like this layout.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/ff_drawable_black">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_gravity="bottom"
        android:background="@color/white">

        // other codes...
    </LinearLayout>

</FrameLayout>

at last i show popup on my MainActivity with some extra parameter set as below.

           //instantiate popup window
            popupWindow = new PopupWindow(viewPopup, LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT, true);

            //display the popup window
            popupWindow.showAtLocation(layout_ff, Gravity.BOTTOM, 0, 0);

Result: enter image description here

it works for me, also solved problem as commented by BaDo. With this Actionbar also can be dimmed.

P.s i am not saying uhmdown's is wrong. i learnt form his answer and try to evolve for my problem. I also confused whether this is a good way or not.

Any suggestions is also appreciated also sorry for my bad English.

How can we stop a running java process through Windows cmd?

start javaw -DSTOP.PORT=8079 -DSTOP.KEY=secret -jar start.jar

start javaw -DSTOP.PORT=8079 -DSTOP.KEY=secret -jar start.jar --stop

How to verify a Text present in the loaded page through WebDriver

Driver.getPageSource() is a bad way to verify text present. Suppose you say, driver.getPageSource().contains("input"); That doesn't verify "input" is present on the screen, only that "input" is present in the html, like an input tag.

I usually verify text on an element by using xpath:

boolean textFound = false;  
try {
    driver.findElement(By.xpath("//*[contains(text(),'someText')]"));
    textFound = true;
} catch (Exception e) {
    textFound = false;
}

If you want an exact text match, just remove the contains function:

driver.findElement(By.xpath("//*[text()='someText']));

What is the purpose of the "role" attribute in HTML?

Is this role attribute necessary?

Answer: Yes.

  • The role attribute is necessary to support Accessible Rich Internet Applications (WAI-ARIA) to define roles in XML-based languages, when the languages do not define their own role attribute.
  • Although this is the reason the role attribute is published by the Protocols and Formats Working Group, the attribute has more general use cases as well.

It provides you:

  • Accessibility
  • Device adaptation
  • Server-side processing
  • Complex data description,...etc.

Disable future dates in jQuery UI Datepicker

http://stefangabos.ro/jquery/zebra-datepicker

use zebra date pickers:

$('#select_month1').Zebra_DatePicker({
  direction: false,
  format: 'Y-m-d',
  pair: $('#select_month2')
});

$('#select_month2').Zebra_DatePicker({
  direction: 1, format: 'Y-m-d',
});

Windows recursive grep command-line

for /f %G in ('dir *.cpp *.h /s/b') do  ( find /i "what you search"  "%G") >> out_file.txt

Regex lookahead, lookbehind and atomic groups

Lookarounds are zero width assertions. They check for a regex (towards right or left of the current position - based on ahead or behind), succeeds or fails when a match is found (based on if it is positive or negative) and discards the matched portion. They don't consume any character - the matching for regex following them (if any), will start at the same cursor position.

Read regular-expression.info for more details.

  • Positive lookahead:

Syntax:

(?=REGEX_1)REGEX_2

Match only if REGEX_1 matches; after matching REGEX_1, the match is discarded and searching for REGEX_2 starts at the same position.

example:

(?=[a-z0-9]{4}$)[a-z]{1,2}[0-9]{2,3}

REGEX_1 is [a-z0-9]{4}$ which matches four alphanumeric chars followed by end of line.
REGEX_2 is [a-z]{1,2}[0-9]{2,3} which matches one or two letters followed by two or three digits.

REGEX_1 makes sure that the length of string is indeed 4, but doesn't consume any characters so that search for REGEX_2 starts at the same location. Now REGEX_2 makes sure that the string matches some other rules. Without look-ahead it would match strings of length three or five.

  • Negative lookahead

Syntax:

(?!REGEX_1)REGEX_2

Match only if REGEX_1 does not match; after checking REGEX_1, the search for REGEX_2 starts at the same position.

example:

(?!.*\bFWORD\b)\w{10,30}$

The look-ahead part checks for the FWORD in the string and fails if it finds it. If it doesn't find FWORD, the look-ahead succeeds and the following part verifies that the string's length is between 10 and 30 and that it contains only word characters a-zA-Z0-9_

Look-behind is similar to look-ahead: it just looks behind the current cursor position. Some regex flavors like javascript doesn't support look-behind assertions. And most flavors that support it (PHP, Python etc) require that look-behind portion to have a fixed length.

  • Atomic groups basically discards/forgets the subsequent tokens in the group once a token matches. Check this page for examples of atomic groups

How to use __doPostBack()

You can try this in your web form with a button called btnSave for example:

<input type="button" id="btnSave" onclick="javascript:SaveWithParameter('Hello Michael')" value="click me"/>

<script type="text/javascript">
function SaveWithParameter(parameter)
{
  __doPostBack('btnSave', parameter)
}
</script>

And in your code behind add something like this to read the value and operate upon it:

public void Page_Load(object sender, EventArgs e)
{
  string parameter = Request["__EVENTARGUMENT"]; // parameter
  // Request["__EVENTTARGET"]; // btnSave
}

Give that a try and let us know if that worked for you.

How can I create a correlation matrix in R?

You could use 'corrplot' package.

d <- data.frame(x1=rnorm(10),
                 x2=rnorm(10),
                 x3=rnorm(10))
M <- cor(d) # get correlations

library('corrplot') #package corrplot
corrplot(M, method = "circle") #plot matrix

enter image description here

More information here: http://cran.r-project.org/web/packages/corrplot/vignettes/corrplot-intro.html

Convert Iterator to ArrayList

Here's a one-liner using Streams

Iterator<?> iterator = ...
List<?> list = StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, 0), false)
                .collect(Collectors.toList());

Default Values to Stored Procedure in Oracle

Default-Values are only considered for parameters NOT given to the function.

So given a function

procedure foo( bar1 IN number DEFAULT 3,
     bar2 IN number DEFAULT 5,
     bar3 IN number DEFAULT 8 );

if you call this procedure with no arguments then it will behave as if called with

foo( bar1 => 3,
     bar2 => 5,
     bar3 => 8 );

but 'NULL' is still a parameter.

foo( 4,
     bar3 => NULL );

This will then act like

foo( bar1 => 4,
     bar2 => 5,
     bar3 => Null );

( oracle allows you to either give the parameter in order they are specified in the procedure, specified by name, or first in order and then by name )

one way to treat NULL the same as a default value would be to default the value to NULL

procedure foo( bar1 IN number DEFAULT NULL,
     bar2 IN number DEFAULT NULL,
     bar3 IN number DEFAULT NULL );

and using a variable with the desired value then

procedure foo( bar1 IN number DEFAULT NULL,
     bar2 IN number DEFAULT NULL,
     bar3 IN number DEFAULT NULL )
AS
     v_bar1    number := NVL( bar1, 3);
     v_bar2    number := NVL( bar2, 5);
     v_bar3    number := NVL( bar3, 8);

How do you use bcrypt for hashing passwords in PHP?

Version 5.5 of PHP will have built-in support for BCrypt, the functions password_hash() and password_verify(). Actually these are just wrappers around the function crypt(), and shall make it easier to use it correctly. It takes care of the generation of a safe random salt, and provides good default values.

The easiest way to use this functions will be:

$hashToStoreInDb = password_hash($password, PASSWORD_BCRYPT);
$isPasswordCorrect = password_verify($password, $existingHashFromDb);

This code will hash the password with BCrypt (algorithm 2y), generates a random salt from the OS random source, and uses the default cost parameter (at the moment this is 10). The second line checks, if the user entered password matches an already stored hash-value.

Should you want to change the cost parameter, you can do it like this, increasing the cost parameter by 1, doubles the needed time to calculate the hash value:

$hash = password_hash($password, PASSWORD_BCRYPT, array("cost" => 11));

In contrast to the "cost" parameter, it is best to omit the "salt" parameter, because the function already does its best to create a cryptographically safe salt.

For PHP version 5.3.7 and later, there exists a compatibility pack, from the same author that made the password_hash() function. For PHP versions before 5.3.7 there is no support for crypt() with 2y, the unicode safe BCrypt algorithm. One could replace it instead with 2a, which is the best alternative for earlier PHP versions.

Spring Boot Java Config Set Session Timeout

server.session.timeout in the application.properties file is now deprecated. The correct setting is:

server.servlet.session.timeout=60s

Also note that Tomcat will not allow you to set the timeout any less than 60 seconds. For details about that minimum setting see https://github.com/spring-projects/spring-boot/issues/7383.

How to Use Order By for Multiple Columns in Laravel 4?

Here's another dodge that I came up with for my base repository class where I needed to order by an arbitrary number of columns:

public function findAll(array $where = [], array $with = [], array $orderBy = [], int $limit = 10)
{
    $result = $this->model->with($with);
    $dataSet = $result->where($where)
        // Conditionally use $orderBy if not empty
        ->when(!empty($orderBy), function ($query) use ($orderBy) {
            // Break $orderBy into pairs
            $pairs = array_chunk($orderBy, 2);
            // Iterate over the pairs
            foreach ($pairs as $pair) {
                // Use the 'splat' to turn the pair into two arguments
                $query->orderBy(...$pair);
            }
        })
        ->paginate($limit)
        ->appends(Input::except('page'));

    return $dataSet;
}

Now, you can make your call like this:

$allUsers = $userRepository->findAll([], [], ['name', 'DESC', 'email', 'ASC'], 100);

Use placeholders in yaml

Context

  • YAML version 1.2
  • user wishes to
    • include variable placeholders in YAML
    • have placeholders replaced with computed values, upon yaml.load
    • be able to use placeholders for both YAML mapping keys and values

Problem

  • YAML does not natively support variable placeholders.
  • Anchors and Aliases almost provide the desired functionality, but these do not work as variable placeholders that can be inserted into arbitrary regions throughout the YAML text. They must be placed as separate YAML nodes.
  • There are some add-on libraries that support arbitrary variable placeholders, but they are not part of the native YAML specification.

Example

Consider the following example YAML. It is well-formed YAML syntax, however it uses (non-standard) curly-brace placeholders with embedded expressions.

The embedded expressions do not produce the desired result in YAML, because they are not part of the native YAML specification. Nevertheless, they are used in this example only to help illustrate what is available with standard YAML and what is not.

part01_customer_info:
  cust_fname:   "Homer"
  cust_lname:   "Himpson"
  cust_motto:   "I love donuts!"
  cust_email:   [email protected]

part01_government_info:
  govt_sales_taxrate: 1.15

part01_purchase_info:
  prch_unit_label:    "Bacon-Wrapped Fancy Glazed Donut"
  prch_unit_price:    3.00
  prch_unit_quant:    7
  prch_product_cost:  "{{prch_unit_price * prch_unit_quant}}"
  prch_total_cost:    "{{prch_product_cost * govt_sales_taxrate}}"   

part02_shipping_info:
  cust_fname:   "{{cust_fname}}"
  cust_lname:   "{{cust_lname}}"
  ship_city:    Houston
  ship_state:   Hexas    

part03_email_info:
  cust_email:     "{{cust_email}}"
  mail_subject:   Thanks for your DoughNutz order!
  mail_notes: |
    We want the mail_greeting to have all the expected values
    with filled-in placeholders (and not curly-braces).
  mail_greeting: |
    Greetings {{cust_fname}} {{cust_lname}}!
    
    We love your motto "{{cust_motto}}" and we agree with you!
    
    Your total purchase price is {{prch_total_cost}}
    

Explanation

  • The substitutions marked in GREEN are readily available in standard YAML, using anchors, aliases, and merge keys.

  • The substitutions marked in YELLOW are technically available in standard YAML, but not without a custom type declaration, or some other binding mechanism.

  • The substitutions marked in RED are not available in standard YAML. Yet there are workarounds and alternatives; such as through string formatting or string template engines (such as python's str.format).

Image explaining the different types of variable substitution in YAML

Details

A frequently-requested feature for YAML is the ability to insert arbitrary variable placeholders that support arbitrary cross-references and expressions that relate to the other content in the same (or transcluded) YAML file(s).

YAML supports anchors and aliases, but this feature does not support arbitrary placement of placeholders and expressions anywhere in the YAML text. They only work with YAML nodes.

YAML also supports custom type declarations, however these are less common, and there are security implications if you accept YAML content from potentially untrusted sources.

YAML addon libraries

There are YAML extension libraries, but these are not part of the native YAML spec.

Workarounds

  • Use YAML in conjunction with a template system, such as Jinja2 or Twig
  • Use a YAML extension library
  • Use sprintf or str.format style functionality from the hosting language

Alternatives

  • YTT YAML Templating essentially a fork of YAML with additional features that may be closer to the goal specified in the OP.
  • Jsonnet shares some similarity with YAML, but with additional features that may be closer to the goal specified in the OP.

See also

Here at SO

Outside SO

What is the PostgreSQL equivalent for ISNULL()

SELECT CASE WHEN field IS NULL THEN 'Empty' ELSE field END AS field_alias

Or more idiomatic:

SELECT coalesce(field, 'Empty') AS field_alias

HTML/CSS--Creating a banner/header

You have a type-o:

its: height: 200x;

and it should be: height: 200px; also check the image url; it should be in the same directory it seems.

Also, dont use 'px' at null (aka '0') values. 0px, 0em, 0% is still 0. :)

top: 0px;

is the same with:

top: 0;

Good Luck!

cmd line rename file with date and time

ls | xargs -I % mv % %_`date +%d%b%Y`

One line is enough. ls all files/dirs under current dir and append date to each file.

What does DIM stand for in Visual Basic and BASIC?

It stands for Dimension, but is generally read as "Create Variable," or "Allocate Space for This."

How do I break a string across more than one line of code in JavaScript?

Break up the string into two pieces 

alert ("Please select file " +
       "to delete");

Javascript onHover event

How about something like this?

<html>
<head>
<script type="text/javascript">

var HoverListener = {
  addElem: function( elem, callback, delay )
  {
    if ( delay === undefined )
    {
      delay = 1000;
    }

    var hoverTimer;

    addEvent( elem, 'mouseover', function()
    {
      hoverTimer = setTimeout( callback, delay );
    } );

    addEvent( elem, 'mouseout', function()
    {
      clearTimeout( hoverTimer );
    } );
  }
}

function tester()
{
  alert( 'hi' );
}

//  Generic event abstractor
function addEvent( obj, evt, fn )
{
  if ( 'undefined' != typeof obj.addEventListener )
  {
    obj.addEventListener( evt, fn, false );
  }
  else if ( 'undefined' != typeof obj.attachEvent )
  {
    obj.attachEvent( "on" + evt, fn );
  }
}

addEvent( window, 'load', function()
{
  HoverListener.addElem(
      document.getElementById( 'test' )
    , tester 
  );
  HoverListener.addElem(
      document.getElementById( 'test2' )
    , function()
      {
        alert( 'Hello World!' );
      }
    , 2300
  );
} );

</script>
</head>
<body>
<div id="test">Will alert "hi" on hover after one second</div>
<div id="test2">Will alert "Hello World!" on hover 2.3 seconds</div>
</body>
</html>

How do I call paint event?

I think you can also call Refresh().

How do I find the length of an array?

In C++, using the std::array class to declare an array, one can easily find the size of an array and also the last element.

#include<iostream>
#include<array>
int main()
{
    std::array<int,3> arr;

    //To find the size of the array
    std::cout<<arr.size()<<std::endl;

    //Accessing the last element
    auto it=arr.end();
    std::cout<<arr.back()<<"\t"<<arr[arr.size()-1]<<"\t"<<*(--it);

    return 0;
}

In fact, array class has a whole lot of other functions which let us use array a standard container.
Reference 1 to C++ std::array class
Reference 2 to std::array class
The examples in the references are helpful.

@property retain, assign, copy, nonatomic in Objective-C

After reading many articles I decided to put all the attributes information together:

  1. atomic //default
  2. nonatomic
  3. strong=retain //default
  4. weak= unsafe_unretained
  5. retain
  6. assign //default
  7. unsafe_unretained
  8. copy
  9. readonly
  10. readwrite //default

Below is a link to the detailed article where you can find these attributes.

Many thanks to all the people who give best answers here!!

Variable property attributes or Modifiers in iOS

Here is the Sample Description from Article

  1. atomic -Atomic means only one thread access the variable(static type). -Atomic is thread safe. -but it is slow in performance -atomic is default behavior -Atomic accessors in a non garbage collected environment (i.e. when using retain/release/autorelease) will use a lock to ensure that another thread doesn't interfere with the correct setting/getting of the value. -it is not actually a keyword.

Example :

@property (retain) NSString *name;

@synthesize name;
  1. nonatomic -Nonatomic means multiple thread access the variable(dynamic type). -Nonatomic is thread unsafe. -but it is fast in performance -Nonatomic is NOT default behavior,we need to add nonatomic keyword in property attribute. -it may result in unexpected behavior, when two different process (threads) access the same variable at the same time.

Example:

@property (nonatomic, retain) NSString *name;

@synthesize name;

Explain:

Suppose there is an atomic string property called "name", and if you call [self setName:@"A"] from thread A, call [self setName:@"B"] from thread B, and call [self name] from thread C, then all operation on different thread will be performed serially which means if one thread is executing setter or getter, then other threads will wait. This makes property "name" read/write safe but if another thread D calls [name release] simultaneously then this operation might produce a crash because there is no setter/getter call involved here. Which means an object is read/write safe (ATOMIC) but not thread safe as another threads can simultaneously send any type of messages to the object. Developer should ensure thread safety for such objects.

If the property "name" was nonatomic, then all threads in above example - A,B, C and D will execute simultaneously producing any unpredictable result. In case of atomic, Either one of A, B or C will execute first but D can still execute in parallel.

  1. strong (iOS4 = retain ) -it says "keep this in the heap until I don't point to it anymore" -in other words " I'am the owner, you cannot dealloc this before aim fine with that same as retain" -You use strong only if you need to retain the object. -By default all instance variables and local variables are strong pointers. -We generally use strong for UIViewControllers (UI item's parents) -strong is used with ARC and it basically helps you , by not having to worry about the retain count of an object. ARC automatically releases it for you when you are done with it.Using the keyword strong means that you own the object.

Example:

@property (strong, nonatomic) ViewController *viewController;

@synthesize viewController;
  1. weak (iOS4 = unsafe_unretained ) -it says "keep this as long as someone else points to it strongly" -the same thing as assign, no retain or release -A "weak" reference is a reference that you do not retain. -We generally use weak for IBOutlets (UIViewController's Childs).This works because the child object only needs to exist as long as the parent object does. -a weak reference is a reference that does not protect the referenced object from collection by a garbage collector. -Weak is essentially assign, a unretained property. Except the when the object is deallocated the weak pointer is automatically set to nil

Example :

@property (weak, nonatomic) IBOutlet UIButton *myButton;

@synthesize myButton;

Strong & Weak Explanation, Thanks to BJ Homer:

Imagine our object is a dog, and that the dog wants to run away (be deallocated). Strong pointers are like a leash on the dog. As long as you have the leash attached to the dog, the dog will not run away. If five people attach their leash to one dog, (five strong pointers to one object), then the dog will not run away until all five leashes are detached. Weak pointers, on the other hand, are like little kids pointing at the dog and saying "Look! A dog!" As long as the dog is still on the leash, the little kids can still see the dog, and they'll still point to it. As soon as all the leashes are detached, though, the dog runs away no matter how many little kids are pointing to it. As soon as the last strong pointer (leash) no longer points to an object, the object will be deallocated, and all weak pointers will be zeroed out. When we use weak? The only time you would want to use weak, is if you wanted to avoid retain cycles (e.g. the parent retains the child and the child retains the parent so neither is ever released).

  1. retain = strong -it is retained, old value is released and it is assigned -retain specifies the new value should be sent -retain on assignment and the old value sent -release -retain is the same as strong. -apple says if you write retain it will auto converted/work like strong only. -methods like "alloc" include an implicit "retain"

Example:

@property (nonatomic, retain) NSString *name;

@synthesize name;
  1. assign -assign is the default and simply performs a variable assignment -assign is a property attribute that tells the compiler how to synthesize the property's setter implementation -I would use assign for C primitive properties and weak for weak references to Objective-C objects.

Example:

@property (nonatomic, assign) NSString *address;

@synthesize address;
  1. unsafe_unretained

    -unsafe_unretained is an ownership qualifier that tells ARC how to insert retain/release calls -unsafe_unretained is the ARC version of assign.

Example:

@property (nonatomic, unsafe_unretained) NSString *nickName;

@synthesize nickName;
  1. copy -copy is required when the object is mutable. -copy specifies the new value should be sent -copy on assignment and the old value sent -release. -copy is like retain returns an object which you must explicitly release (e.g., in dealloc) in non-garbage collected environments. -if you use copy then you still need to release that in dealloc. -Use this if you need the value of the object as it is at this moment, and you don't want that value to reflect any changes made by other owners of the object. You will need to release the object when you are finished with it because you are retaining the copy.

Example:

@property (nonatomic, copy) NSArray *myArray;

@synthesize myArray;

Download and open PDF file using Ajax

Do you have to do it with Ajax? Coouldn't it be a possibility to load it in an iframe?

What's the best way to determine the location of the current PowerShell script?

I needed to know the script name and where it is executing from.

Prefixing "$global:" to the MyInvocation structure returns the full path and script name when called from both the main script, and the main line of an imported .PSM1 library file. It also works from within a function in an imported library.

After much fiddling around, I settled on using $global:MyInvocation.InvocationName. It works reliably with CMD launch, Run With Powershell, and the ISE. Both local and UNC launches return the correct path.

Fatal error: Call to undefined function curl_init()

On old versions of Debian and Ubuntu, you solved this by installing the Curl extension for PHP, and restarting the webserver. Assuming the webserver is Apache 2:

sudo apt-get install php5-curl
sudo service apache2 restart

On newer versions, the package name as changed:

sudo apt install php-curl

It's possible you'll need to install more:

sudo apt-get install curl libcurl3 libcurl3-dev;

What is the best way to concatenate two vectors?

In the direction of Bradgonesurfing's answer, many times one doesn't really need to concatenate two vectors (O(n)), but instead just work with them as if they were concatenated (O(1)). If this is your case, it can be done without the need of Boost libraries.

The trick is to create a vector proxy: a wrapper class which manipulates references to both vectors, externally seen as a single, contiguous one.

USAGE

std::vector<int> A{ 1, 2, 3, 4, 5};
std::vector<int> B{ 10, 20, 30 };

VecProxy<int> AB(A, B);  // ----> O(1). No copies performed.

for (size_t i = 0; i < AB.size(); ++i)
    std::cout << AB[i] << " ";  // 1 2 3 4 5 10 20 30

IMPLEMENTATION

template <class T>
class VecProxy {
private:
    std::vector<T>& v1, v2;
public:
    VecProxy(std::vector<T>& ref1, std::vector<T>& ref2) : v1(ref1), v2(ref2) {}
    const T& operator[](const size_t& i) const;
    const size_t size() const;
};

template <class T>
const T& VecProxy<T>::operator[](const size_t& i) const{
    return (i < v1.size()) ? v1[i] : v2[i - v1.size()];
};

template <class T>
const size_t VecProxy<T>::size() const { return v1.size() + v2.size(); };

MAIN BENEFIT

It's O(1) (constant time) to create it, and with minimal extra memory allocation.

SOME STUFF TO CONSIDER

  • You should only go for it if you really know what you're doing when dealing with references. This solution is intended for the specific purpose of the question made, for which it works pretty well. To employ it in any other context may lead to unexpected behavior if you are not sure on how references work.
  • In this example, AB does not provide a non-const access operator ([ ]). Feel free to include it, but keep in mind: since AB contains references, to assign it values will also affect the original elements within A and/or B. Whether or not this is a desirable feature, it's an application-specific question one should carefully consider.
  • Any changes directly made to either A or B (like assigning values, sorting, etc.) will also "modify" AB. This is not necessarily bad (actually, it can be very handy: AB does never need to be explicitly updated to keep itself synchronized to both A and B), but it's certainly a behavior one must be aware of. Important exception: to resize A and/or B to sth bigger may lead these to be reallocated in memory (for the need of contiguous space), and this would in turn invalidate AB.
  • Because every access to an element is preceded by a test (namely, "i < v1.size()"), VecProxy access time, although constant, is also a bit slower than that of vectors.
  • This approach can be generalized to n vectors. I haven't tried, but it shouldn't be a big deal.

How to use RecyclerView inside NestedScrollView?

At least as far back as Material Components 1.3.0-alpha03, it doesn't matter if the RecyclerView is nested (in something other than a ScrollView or NestedScrollView). Just put app:layout_behavior="@string/appbar_scrolling_view_behavior" on its top level parent that's a sibling of the AppBarLayout in the CoordinatorLayout.

This has been working for me when using a single Activity architecture with Jetpack Naviagation, where all Fragments are sharing the same AppBar from the Activity's layout. I make the FragmentContainer the direct child of the CoordinatorLayout that also contains the AppBarLayout, like below. The RecyclerViews in the various fragments are scrolling normally and the AppBar folds away and reappears as expected.

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/coordinatorLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.fragment.app.FragmentContainerView
            android:id="@+id/nav_host_fragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            app:defaultNavHost="true"
            app:navGraph="@navigation/mobile_navigation"/>

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appbar_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:liftOnScroll="true">

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:minHeight="?attr/actionBarSize"
                android:theme="?attr/actionBarTheme"
                app:layout_scrollFlags="scroll|enterAlways|snap" />

        </com.google.android.material.appbar.AppBarLayout>

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

liftOnScroll (used to for app bars to look like they have zero elevation when at the top of the page) works if each fragment passes the ID of its RecyclerView to AppBarLayout.liftOnScrollTargetViewId in Fragment.onResume. Or pass 0 if the Fragment doesn't scroll.

How to parse a CSV in a Bash script?

I was looking for an elegant solution that support quoting and wouldn't require installing anything fancy on my VMware vMA appliance. Turns out this simple python script does the trick! (I named the script csv2tsv.py, since it converts CSV into tab-separated values - TSV)

#!/usr/bin/env python

import sys, csv

with sys.stdin as f:
    reader = csv.reader(f)
    for row in reader:
        for col in row:
            print col+'\t',
        print

Tab-separated values can be split easily with the cut command (no delimiter needs to be specified, tab is the default). Here's a sample usage/output:

> esxcli -h $VI_HOST --formatter=csv network vswitch standard list |csv2tsv.py|cut -f12
Uplinks
vmnic4,vmnic0,
vmnic5,vmnic1,
vmnic6,vmnic2,

In my scripts I'm actually going to parse tsv output line by line and use read or cut to get the fields I need.

The mysqli extension is missing. Please check your PHP configuration

  1. Find out which php.ini is used.
  2. In file php.ini this line:

    extension=mysqli
    
  3. Replace by:

    extension="C:\php\ext\php_mysqli.dll"
    
  4. Restart apache

Using C# to check if string contains a string in string array

Most of those solution is correct, but if You need check values without case sensitivity

using System.Linq;
...
string stringToCheck = "text1text2text3";
string[] stringArray = { "text1", "someothertext"};

if(stringArray.Any(a=> String.Equals(a, stringToCheck, StringComparison.InvariantCultureIgnoreCase)) )
{ 
   //contains
}

if (stringArray.Any(w=> w.IndexOf(stringToCheck, StringComparison.InvariantCultureIgnoreCase)>=0))
{
   //contains
}

dotNetFiddle example

Module AppRegistry is not registered callable module (calling runApplication)

I had this issue - it was odd because I reset my repo to a time when the app was working. The issue was with my simulator (iOS).

For me the solution was to

  1. kill the simulator program (quit)
  2. then - close the terminal window that is opened when simulator is ran (Metro Bundler) Image of my terminal window

How to connect Bitbucket to Jenkins properly

I had this problem and it turned out the issue was that I had named my repository with CamelCase. Bitbucket automatically changes the URL of your repository to be all lower case and that gets sent to Jenkins in the webhook. Jenkins then searches for projects with a matching repository. If you, like me, have CamelCase in your repository URL in your project configuration you will be able to check out code, but the pattern matching on the webhook request will fail.

Just change your repo URL to be all lower case instead of CamelCase and the pattern match should find your project.

How to detect if a string contains at least a number?

DECLARE @str AS VARCHAR(50)
SET @str = 'PONIES!!...pon1es!!...p0n1es!!'

IF PATINDEX('%[0-9]%', @str) > 0
   PRINT 'YES, The string has numbers'
ELSE
   PRINT 'NO, The string does not have numbers' 

Tried to Load Angular More Than Once

The problem for me was, I had taken backup of controller (js) file with some other changes in the same folder and bundling loaded both the controller files (original and backup js). Removing backup from the scripts folder, that was bundled solved the issue.

Is there a way to remove the separator line from a UITableView?

In the ViewDidLoad Method, you have to write this line.

tableViews.separatorStyle = UITableViewCellSeparatorStyleNone;

This is working Code.

Git Clone from GitHub over https with two-factor authentication

1st: Get personal access token. https://github.com/settings/tokens
2nd: Put account & the token. Example is here:

$ git push
Username for 'https://github.com':            # Put your GitHub account name
Password for 'https://{USERNAME}@github.com': # Put your Personal access token

Link on how to create a personal access token: https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line

How to get textLabel of selected row in swift?

If you're in a class inherited from UITableViewController, then this is the swift version:

override func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
    let cell = self.tableView.cellForRowAtIndexPath(indexPath)
    NSLog("did select and the text is \(cell?.textLabel?.text)")
}

Note that cell is an optional, so it must be unwrapped - and the same for textLabel. If any of the 2 is nil (unlikely to happen, because the method is called with a valid index path), if you want to be sure that a valid value is printed, then you should check that both cell and textLabel are both not nil:

override func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {
    let cell = self.tableView.cellForRowAtIndexPath(indexPath)
    let text = cell?.textLabel?.text
    if let text = text {
        NSLog("did select and the text is \(text)")
    }
}

How to define static constant in a class in swift

What about using computed properties?

class MyClass {
  class var myConstant: String { return "What is Love? Baby don't hurt me" }
}

MyClass.myConstant

How to encode Doctrine entities to JSON in Symfony 2.0 AJAX application?

in Symfony 2.3

/app/config/config.yml

framework:
    # ?????? ??????????????? ???????? ? ???????, json, xml ? ???????
    serializer:
        enabled: true

services:
    object_normalizer:
        class: Symfony\Component\Serializer\Normalizer\GetSetMethodNormalizer
        tags:
        # ???????? ? ???? ????????? ???? ??????, ??? ??. ?????, ?.?. ????? ???????? ?? ?????
          - { name: serializer.normalizer }

and example for your controller:

/**
 * ????? ???????? ?? ?? ??????? ? ?? ?????
 * @Route("/search/", name="orgunitSearch")
 */
public function orgunitSearchAction()
{
    $array = $this->get('request')->query->all();

    $entity = $this->getDoctrine()
        ->getRepository('IntranetOrgunitBundle:Orgunit')
        ->findOneBy($array);

    $serializer = $this->get('serializer');
    //$json = $serializer->serialize($entity, 'json');
    $array = $serializer->normalize($entity);

    return new JsonResponse( $array );
}

but the problems with the field type \DateTime will remain.

Recursive search and replace in text files on Mac and Linux

This is my workable one. on mac OS X 10.10.4

grep -e 'this' -rl . | xargs sed -i '' 's/this/that/g'

The above ones use find will change the files that do not contain the search text (add a new line at the file end), which is verbose.

How to change date format (MM/DD/YY) to (YYYY-MM-DD) in date picker

I had the same issue and I have tried many answers but nothing worked.

I tried the following and it worked successfully :

<input type=text  data-date-format='yy-mm-dd'  > 

How to get element-wise matrix multiplication (Hadamard product) in numpy?

import numpy as np
x = np.array([[1,2,3], [4,5,6]])
y = np.array([[-1, 2, 0], [-2, 5, 1]])

x*y
Out: 
array([[-1,  4,  0],
       [-8, 25,  6]])

%timeit x*y
1000000 loops, best of 3: 421 ns per loop

np.multiply(x,y)
Out: 
array([[-1,  4,  0],
       [-8, 25,  6]])

%timeit np.multiply(x, y)
1000000 loops, best of 3: 457 ns per loop

Both np.multiply and * would yield element wise multiplication known as the Hadamard Product

%timeit is ipython magic

The difference between the 'Local System' account and the 'Network Service' account?

Since there is so much confusion about functionality of standard service accounts, I'll try to give a quick run down.

First the actual accounts:

  • LocalService account (preferred)

    A limited service account that is very similar to Network Service and meant to run standard least-privileged services. However, unlike Network Service it accesses the network as an Anonymous user.

    • Name: NT AUTHORITY\LocalService
    • the account has no password (any password information you provide is ignored)
    • HKCU represents the LocalService user account
    • has minimal privileges on the local computer
    • presents anonymous credentials on the network
    • SID: S-1-5-19
    • has its own profile under the HKEY_USERS registry key (HKEY_USERS\S-1-5-19)

     

  • NetworkService account

    Limited service account that is meant to run standard privileged services. This account is far more limited than Local System (or even Administrator) but still has the right to access the network as the machine (see caveat above).

    • NT AUTHORITY\NetworkService
    • the account has no password (any password information you provide is ignored)
    • HKCU represents the NetworkService user account
    • has minimal privileges on the local computer
    • presents the computer's credentials (e.g. MANGO$) to remote servers
    • SID: S-1-5-20
    • has its own profile under the HKEY_USERS registry key (HKEY_USERS\S-1-5-20)
    • If trying to schedule a task using it, enter NETWORK SERVICE into the Select User or Group dialog

     

  • LocalSystem account (dangerous, don't use!)

    Completely trusted account, more so than the administrator account. There is nothing on a single box that this account cannot do, and it has the right to access the network as the machine (this requires Active Directory and granting the machine account permissions to something)

    • Name: .\LocalSystem (can also use LocalSystem or ComputerName\LocalSystem)
    • the account has no password (any password information you provide is ignored)
    • SID: S-1-5-18
    • does not have any profile of its own (HKCU represents the default user)
    • has extensive privileges on the local computer
    • presents the computer's credentials (e.g. MANGO$) to remote servers

     

Above when talking about accessing the network, this refers solely to SPNEGO (Negotiate), NTLM and Kerberos and not to any other authentication mechanism. For example, processing running as LocalService can still access the internet.

The general issue with running as a standard out of the box account is that if you modify any of the default permissions you're expanding the set of things everything running as that account can do. So if you grant DBO to a database, not only can your service running as Local Service or Network Service access that database but everything else running as those accounts can too. If every developer does this the computer will have a service account that has permissions to do practically anything (more specifically the superset of all of the different additional privileges granted to that account).

It is always preferable from a security perspective to run as your own service account that has precisely the permissions you need to do what your service does and nothing else. However, the cost of this approach is setting up your service account, and managing the password. It's a balancing act that each application needs to manage.

In your specific case, the issue that you are probably seeing is that the the DCOM or COM+ activation is limited to a given set of accounts. In Windows XP SP2, Windows Server 2003, and above the Activation permission was restricted significantly. You should use the Component Services MMC snapin to examine your specific COM object and see the activation permissions. If you're not accessing anything on the network as the machine account you should seriously consider using Local Service (not Local System which is basically the operating system).


In Windows Server 2003 you cannot run a scheduled task as

  • NT_AUTHORITY\LocalService (aka the Local Service account), or
  • NT AUTHORITY\NetworkService (aka the Network Service account).

That capability only was added with Task Scheduler 2.0, which only exists in Windows Vista/Windows Server 2008 and newer.

A service running as NetworkService presents the machine credentials on the network. This means that if your computer was called mango, it would present as the machine account MANGO$:

enter image description here

Migrating from VMWARE to VirtualBox

Note: I am not sure this will be of any help to you, but you never know.

I found this link:http://www.ubuntugeek.com/howto-convert-vmware-image-to-virtualbox-image.html

ENJOY :-)

How to get file path from OpenFileDialog and FolderBrowserDialog?

For OpenFileDialog:

OpenFileDialog choofdlog = new OpenFileDialog();
choofdlog.Filter = "All Files (*.*)|*.*";
choofdlog.FilterIndex = 1;
choofdlog.Multiselect = true;

if (choofdlog.ShowDialog() == DialogResult.OK)    
{     
    string sFileName = choofdlog.FileName; 
    string[] arrAllFiles = choofdlog.FileNames; //used when Multiselect = true           
}

For FolderBrowserDialog:

FolderBrowserDialog fbd = new FolderBrowserDialog();
fbd.Description = "Custom Description"; 

if (fbd.ShowDialog() == DialogResult.OK)
{
    string sSelectedPath = fbd.SelectedPath;
}

To access selected folder and selected file name you can declare both string at class level.

namespace filereplacer
{
   public partial class Form1 : Form
   {
      string sSelectedFile;
      string sSelectedFolder;

      public Form1()
      {
         InitializeComponent();
      }

      private void direc_Click(object sender, EventArgs e)
      {
         FolderBrowserDialog fbd = new FolderBrowserDialog();
         //fbd.Description = "Custom Description"; //not mandatory

         if (fbd.ShowDialog() == DialogResult.OK)      
               sSelectedFolder = fbd.SelectedPath;
         else
               sSelectedFolder = string.Empty;    
      }

      private void choof_Click(object sender, EventArgs e)
      {
         OpenFileDialog choofdlog = new OpenFileDialog();
         choofdlog.Filter = "All Files (*.*)|*.*";
         choofdlog.FilterIndex = 1;
         choofdlog.Multiselect = true;

         if (choofdlog.ShowDialog() == DialogResult.OK)                 
             sSelectedFile = choofdlog.FileName;            
         else
             sSelectedFile = string.Empty;       
      }

      private void replacebtn_Click(object sender, EventArgs e)
      {
          if(sSelectedFolder != string.Empty && sSelectedFile != string.Empty)
          {
               //use selected folder path and file path
          }
      }
      ....
}

NOTE:

As you have kept choofdlog.Multiselect=true;, that means in the OpenFileDialog() you are able to select multiple files (by pressing ctrl key and left mouse click for selection).

In that case you could get all selected files in string[]:

At Class Level:

string[] arrAllFiles;

Locate this line (when Multiselect=true this line gives first file only):

sSelectedFile = choofdlog.FileName; 

To get all files use this:

arrAllFiles = choofdlog.FileNames; //this line gives array of all selected files

Difference between numpy dot() and Python 3.5+ matrix multiplication @

Just FYI, @ and its numpy equivalents dot and matmul are all equally fast. (Plot created with perfplot, a project of mine.)

enter image description here

Code to reproduce the plot:

import perfplot
import numpy


def setup(n):
    A = numpy.random.rand(n, n)
    x = numpy.random.rand(n)
    return A, x


def at(data):
    A, x = data
    return A @ x


def numpy_dot(data):
    A, x = data
    return numpy.dot(A, x)


def numpy_matmul(data):
    A, x = data
    return numpy.matmul(A, x)


perfplot.show(
    setup=setup,
    kernels=[at, numpy_dot, numpy_matmul],
    n_range=[2 ** k for k in range(15)],
)

Hide div if screen is smaller than a certain width

Is your logic not round the wrong way in that example, you have it hiding when the screen is bigger than 1024. Reverse the cases, make the none in to a block and vice versa.

How to get the first and last date of the current year?

---Lalmuni Demos---

create table Users
(
userid int,date_of_birth date
)

---insert values---

insert into Users values(4,'9/10/1991')

select DATEDIFF(year,date_of_birth, getdate()) - (CASE WHEN (DATEADD(year, DATEDIFF(year,date_of_birth, getdate()),date_of_birth)) > getdate() THEN 1 ELSE 0 END) as Years, 
MONTH(getdate() - (DATEADD(year, DATEDIFF(year, date_of_birth, getdate()), date_of_birth))) - 1 as Months, 
DAY(getdate() - (DATEADD(year, DATEDIFF(year,date_of_birth, getdate()), date_of_birth))) - 1 as Days,
from users

Should we pass a shared_ptr by reference or by value?

Here's Herb Sutter's take

Guideline: Don’t pass a smart pointer as a function parameter unless you want to use or manipulate the smart pointer itself, such as to share or transfer ownership.

Guideline: Express that a function will store and share ownership of a heap object using a by-value shared_ptr parameter.

Guideline: Use a non-const shared_ptr& parameter only to modify the shared_ptr. Use a const shared_ptr& as a parameter only if you’re not sure whether or not you’ll take a copy and share ownership; otherwise use widget* instead (or if not nullable, a widget&).

What is a CSRF token? What is its importance and how does it work?

Yes, the post data is safe. But the origin of that data is not. This way somebody can trick user with JS into logging in to your site, while browsing attacker's web page.

In order to prevent that, django will send a random key both in cookie, and form data. Then, when users POSTs, it will check if two keys are identical. In case where user is tricked, 3rd party website cannot get your site's cookies, thus causing auth error.

How to reverse MD5 to get the original string?

Its not possible thats the whole point of hashing. You can however bruteforce by going through all possibilities (using all possible digits characters in every possible order) and hashing them and checking for a collision.

for more information on hashing and MD5 etc see: http://en.wikipedia.org/wiki/MD5 , http://en.wikipedia.org/wiki/Hash_function , http://en.wikipedia.org/wiki/Cryptographic_hash_function and http://onin.com/hhh/hhhexpl.html

I myself created my own app to do this, its open source you can check the link: http://sourceforge.net/projects/jpassrecovery/ and of course the source. Here is the source for easy access it has a basic implementation in the comments:

Bruter.java:

import java.util.ArrayList;

public class Bruter {

    public ArrayList<String> characters = new ArrayList<>();
    public boolean found = false;
    public int maxLength;
    public int minLength;
    public int count;
    long starttime, endtime;
    public int minutes, seconds, hours, days;
    public char[] specialCharacters = {'~', '`', '!', '@', '#', '$', '%', '^',
        '&', '*', '(', ')', '_', '-', '+', '=', '{', '}', '[', ']', '|', '\\',
        ';', ':', '\'', '"', '<', '.', ',', '>', '/', '?', ' '};
    public boolean done = false;
    public boolean paused = false;

    public boolean isFound() {
        return found;
    }

    public void setPaused(boolean paused) {
        this.paused = paused;
    }

    public boolean isPaused() {
        return paused;
    }

    public void setFound(boolean found) {
        this.found = found;
    }

    public synchronized void setEndtime(long endtime) {
        this.endtime = endtime;
    }

    public int getCounter() {
        return count;
    }

    public long getRemainder() {
        return getNumberOfPossibilities() - count;
    }

    public long getNumberOfPossibilities() {
        long possibilities = 0;
        for (int i = minLength; i <= maxLength; i++) {
            possibilities += (long) Math.pow(characters.size(), i);
        }
        return possibilities;
    }

    public void addExtendedSet() {
        for (char c = (char) 0; c <= (char) 31; c++) {
            characters.add(String.valueOf(c));
        }
    }

    public void addStandardCharacterSet() {
        for (char c = (char) 32; c <= (char) 127; c++) {
            characters.add(String.valueOf(c));
        }
    }

    public void addLowerCaseLetters() {
        for (char c = 'a'; c <= 'z'; c++) {
            characters.add(String.valueOf(c));
        }
    }

    public void addDigits() {
        for (int c = 0; c <= 9; c++) {
            characters.add(String.valueOf(c));
        }
    }

    public void addUpperCaseLetters() {
        for (char c = 'A'; c <= 'Z'; c++) {
            characters.add(String.valueOf(c));
        }
    }

    public void addSpecialCharacters() {
        for (char c : specialCharacters) {
            characters.add(String.valueOf(c));
        }
    }

    public void setMaxLength(int i) {
        maxLength = i;
    }

    public void setMinLength(int i) {
        minLength = i;
    }

    public int getPerSecond() {
        int i;
        try {
            i = (int) (getCounter() / calculateTimeDifference());
        } catch (Exception ex) {
            return 0;
        }
        return i;

    }

    public String calculateTimeElapsed() {
        long timeTaken = calculateTimeDifference();
        seconds = (int) timeTaken;
        if (seconds > 60) {
            minutes = (int) (seconds / 60);
            if (minutes * 60 > seconds) {
                minutes = minutes - 1;
            }

            if (minutes > 60) {
                hours = (int) minutes / 60;
                if (hours * 60 > minutes) {
                    hours = hours - 1;
                }
            }

            if (hours > 24) {
                days = (int) hours / 24;
                if (days * 24 > hours) {
                    days = days - 1;
                }
            }
            seconds -= (minutes * 60);
            minutes -= (hours * 60);
            hours -= (days * 24);
            days -= (hours * 24);
        }
        return "Time elapsed: " + days + "days " + hours + "h " + minutes + "min " + seconds + "s";
    }

    private long calculateTimeDifference() {
        long timeTaken = (long) ((endtime - starttime) * (1 * Math.pow(10, -9)));
        return timeTaken;
    }

    public boolean excludeChars(String s) {
        char[] arrayChars = s.toCharArray();
        for (int i = 0; i < arrayChars.length; i++) {
            characters.remove(arrayChars[i] + "");
        }
        if (characters.size() < maxLength) {
            return false;
        } else {
            return true;

        }
    }

    public int getMaxLength() {
        return maxLength;
    }

    public int getMinLength() {
        return minLength;
    }

    public void setIsDone(Boolean b) {
        done = b;
    }

    public boolean isDone() {
        return done;
    }
}

HashBruter.java:

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.zip.Adler32;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
import javax.swing.JOptionPane;

public class HashBruter extends Bruter {
    /*
     * public static void main(String[] args) {
     *
     * final HashBruter hb = new HashBruter();
     *
     * hb.setMaxLength(5); hb.setMinLength(1);
     *
     * hb.addSpecialCharacters(); hb.addUpperCaseLetters();
     * hb.addLowerCaseLetters(); hb.addDigits();
     *
     * hb.setType("sha-512");
     *
     * hb.setHash("282154720ABD4FA76AD7CD5F8806AA8A19AEFB6D10042B0D57A311B86087DE4DE3186A92019D6EE51035106EE088DC6007BEB7BE46994D1463999968FBE9760E");
     *
     * Thread thread = new Thread(new Runnable() {
     *
     * @Override public void run() { hb.tryBruteForce(); } });
     *
     * thread.start();
     *
     * while (!hb.isFound()) { System.out.println("Hash: " +
     * hb.getGeneratedHash()); System.out.println("Number of Possibilities: " +
     * hb.getNumberOfPossibilities()); System.out.println("Checked hashes: " +
     * hb.getCounter()); System.out.println("Estimated hashes left: " +
     * hb.getRemainder()); }
     *
     * System.out.println("Found " + hb.getType() + " hash collision: " +
     * hb.getGeneratedHash() + " password is: " + hb.getPassword());
     *
     * }
     */

    public String hash, generatedHash, password;
    public String type;

    public String getType() {
        return type;
    }

    public String getPassword() {
        return password;
    }

    public void setHash(String p) {
        hash = p;
    }

    public void setType(String digestType) {
        type = digestType;
    }

    public String getGeneratedHash() {
        return generatedHash;
    }

    public void tryBruteForce() {
        starttime = System.nanoTime();
        for (int size = minLength; size <= maxLength; size++) {
            if (found == true || done == true) {
                break;
            } else {
                while (paused) {
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }
                generateAllPossibleCombinations("", size);
            }
        }
        done = true;
    }

    private void generateAllPossibleCombinations(String baseString, int length) {
        while (paused) {
            try {
                Thread.sleep(500);
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            }
        }
        if (found == false || done == false) {
            if (baseString.length() == length) {
                if(type.equalsIgnoreCase("crc32")) {
                generatedHash = generateCRC32(baseString);
                } else if(type.equalsIgnoreCase("adler32")) {
                generatedHash = generateAdler32(baseString);
                } else if(type.equalsIgnoreCase("crc16")) {
                    generatedHash=generateCRC16(baseString);
                } else if(type.equalsIgnoreCase("crc64")) {
                    generatedHash=generateCRC64(baseString.getBytes());
                }
                else {
                generatedHash = generateHash(baseString.toCharArray());
                }
                    password = baseString;
                if (hash.equals(generatedHash)) {
                    password = baseString;
                    found = true;
                    done = true;
                }
                count++;
            } else if (baseString.length() < length) {
                for (int n = 0; n < characters.size(); n++) {
                    generateAllPossibleCombinations(baseString + characters.get(n), length);
                }
            }
        }
    }

    private String generateHash(char[] passwordChar) {
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance(type);
        } catch (NoSuchAlgorithmException e1) {
            JOptionPane.showMessageDialog(null, "No such algorithm for hashes exists", "Error", JOptionPane.ERROR_MESSAGE);
        }
        String passwordString = new String(passwordChar);
        byte[] passwordByte = passwordString.getBytes();
        md.update(passwordByte, 0, passwordByte.length);
        byte[] encodedPassword = md.digest();
        String encodedPasswordInString = toHexString(encodedPassword);
        return encodedPasswordInString;
    }

    private void byte2hex(byte b, StringBuffer buf) {
        char[] hexChars = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
            '9', 'A', 'B', 'C', 'D', 'E', 'F'};
        int high = ((b & 0xf0) >> 4);
        int low = (b & 0x0f);
        buf.append(hexChars[high]);
        buf.append(hexChars[low]);
    }

    private String toHexString(byte[] block) {
        StringBuffer buf = new StringBuffer();
        int len = block.length;
        for (int i = 0; i < len; i++) {
            byte2hex(block[i], buf);
        }
        return buf.toString();
    }

    private String generateCRC32(String baseString) {

                //Convert string to bytes
                byte bytes[] = baseString.getBytes();

                Checksum checksum = new CRC32();

                /*
                 * To compute the CRC32 checksum for byte array, use
                 *
                 * void update(bytes[] b, int start, int length)
                 * method of CRC32 class.
                 */

                checksum.update(bytes,0,bytes.length);

                /*
                 * Get the generated checksum using
                 * getValue method of CRC32 class.
                 */
                return String.valueOf(checksum.getValue());
    }   
    private String generateAdler32(String baseString) {

                //Convert string to bytes
                byte bytes[] = baseString.getBytes();

                Checksum checksum = new Adler32();

                /*
                 * To compute the CRC32 checksum for byte array, use
                 *
                 * void update(bytes[] b, int start, int length)
                 * method of CRC32 class.
                 */

                checksum.update(bytes,0,bytes.length);

                /*
                 * Get the generated checksum using
                 * getValue method of CRC32 class.
                 */
                return String.valueOf(checksum.getValue());
    }
/*************************************************************************
 *  Compilation:  javac CRC16.java
 *  Execution:    java CRC16 s
 *  
 *  Reads in a string s as a command-line argument, and prints out
 *  its 16-bit Cyclic Redundancy Check (CRC16). Uses a lookup table.
 *
 *  Reference:  http://www.gelato.unsw.edu.au/lxr/source/lib/crc16.c
 *
 *  % java CRC16 123456789
 *  CRC16 = bb3d
 *
 * Uses irreducible polynomial:  1 + x^2 + x^15 + x^16
 *
 *
 *************************************************************************/
    private String generateCRC16(String baseString) {
                int[] table = {
            0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
            0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
            0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
            0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
            0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
            0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
            0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
            0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
            0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
            0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
            0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
            0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
            0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
            0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
            0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
            0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
            0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
            0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
            0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
            0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
            0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
            0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
            0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
            0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
            0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
            0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
            0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
            0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
            0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
            0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
            0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
            0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040,
        };


        byte[] bytes = baseString.getBytes();
        int crc = 0x0000;
        for (byte b : bytes) {
            crc = (crc >>> 8) ^ table[(crc ^ b) & 0xff];
        }

        return Integer.toHexString(crc);
    }
    /*******************************************************************************
 * Copyright (c) 2009, 2012 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *    
 *******************************************************************************/

/**
 * CRC64 checksum calculator based on the polynom specified in ISO 3309. The
 * implementation is based on the following publications:
 * 
 * <ul>
 * <li>http://en.wikipedia.org/wiki/Cyclic_redundancy_check</li>
 * <li>http://www.geocities.com/SiliconValley/Pines/8659/crc.htm</li>
 * </ul>
 */
    private static final long POLY64REV = 0xd800000000000000L;

    private static final long[] LOOKUPTABLE;

    static {
        LOOKUPTABLE = new long[0x100];
        for (int i = 0; i < 0x100; i++) {
            long v = i;
            for (int j = 0; j < 8; j++) {
                if ((v & 1) == 1) {
                    v = (v >>> 1) ^ POLY64REV;
                } else {
                    v = (v >>> 1);
                }
            }
            LOOKUPTABLE[i] = v;
        }
    }

    /**
     * Calculates the CRC64 checksum for the given data array.
     * 
     * @param data
     *            data to calculate checksum for
     * @return checksum value
     */
    public static String generateCRC64(final byte[] data) {
        long sum = 0;
        for (int i = 0; i < data.length; i++) {
            final int lookupidx = ((int) sum ^ data[i]) & 0xff;
            sum = (sum >>> 8) ^ LOOKUPTABLE[lookupidx];
        }
        return String.valueOf(sum);
    }
}

you would use it like:

      final HashBruter hb = new HashBruter();

      hb.setMaxLength(5); hb.setMinLength(1);

     hb.addSpecialCharacters(); hb.addUpperCaseLetters();
     hb.addLowerCaseLetters(); hb.addDigits();

      hb.setType("sha-512");

                   hb.setHash("282154720ABD4FA76AD7CD5F8806AA8A19AEFB6D10042B0D57A311B86087DE4DE3186A92019D6EE51035106EE088DC6007BEB7BE46994D1463999968FBE9760E");

      Thread thread = new Thread(new Runnable() {

      @Override public void run() { hb.tryBruteForce(); } });

      thread.start();

      while (!hb.isFound()) { System.out.println("Hash: " +
      hb.getGeneratedHash()); System.out.println("Number of Possibilities: " +
      hb.getNumberOfPossibilities()); System.out.println("Checked hashes: " +
     hb.getCounter()); System.out.println("Estimated hashes left: " +
     hb.getRemainder()); }

     System.out.println("Found " + hb.getType() + " hash collision: " +
     hb.getGeneratedHash() + " password is: " + hb.getPassword());

Reading all files in a directory, store them in objects, and send the object

I just wrote this and it looks more clean to me:

_x000D_
_x000D_
const fs = require('fs');
const util = require('util');

const readdir = util.promisify(fs.readdir);
const readFile = util.promisify(fs.readFile);

const readFiles = async dirname => {
    try {
        const filenames = await readdir(dirname);
        console.log({ filenames });
        const files_promise = filenames.map(filename => {
            return readFile(dirname + filename, 'utf-8');
        });
        const response = await Promise.all(files_promise);
        //console.log({ response })
        //return response
        return filenames.reduce((accumlater, filename, currentIndex) => {
            const content = response[currentIndex];
            accumlater[filename] = {
                content,
            };
            return accumlater;
        }, {});
    } catch (error) {
        console.error(error);
    }
};

const main = async () => {

    const response = await readFiles(
        './folder-name',
    );
    console.log({ response });
};
_x000D_
_x000D_
_x000D_

You can modify the response format according to your need. The response format from this code will look like:

{
   "filename-01":{
      "content":"This is the sample content of the file"
   },
   "filename-02":{
      "content":"This is the sample content of the file"
   }
}

Disabling browser caching for all browsers from ASP.NET

This is what we use in ASP.NET:

// Stop Caching in IE
Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);

// Stop Caching in Firefox
Response.Cache.SetNoStore();

It stops caching in Firefox and IE, but we haven't tried other browsers. The following response headers are added by these statements:

Cache-Control: no-cache, no-store
Pragma: no-cache

python socket.error: [Errno 98] Address already in use

There is obviously another process listening on the port. You might find out that process by using the following command:

$ lsof -i :8000

or change your tornado app's port. tornado's error info not Explicitly on this.

Finding an item in a List<> using C#

var myItem = myList.Find(item => item.property == "something");

Gunicorn worker timeout error

Frank's answer pointed me in the right direction. I have a Digital Ocean droplet accessing a managed Digital Ocean Postgresql database. All I needed to do was add my droplet to the database's "Trusted Sources".

(click on database in DO console, then click on settings. Edit Trusted Sources and select droplet name (click in editable area and it will be suggested to you)).

Equivalent of LIMIT and OFFSET for SQL Server?

The equivalent of LIMIT is SET ROWCOUNT, but if you want generic pagination it's better to write a query like this:

;WITH Results_CTE AS
(
    SELECT
        Col1, Col2, ...,
        ROW_NUMBER() OVER (ORDER BY SortCol1, SortCol2, ...) AS RowNum
    FROM Table
    WHERE <whatever>
)
SELECT *
FROM Results_CTE
WHERE RowNum >= @Offset
AND RowNum < @Offset + @Limit

The advantage here is the parameterization of the offset and limit in case you decide to change your paging options (or allow the user to do so).

Note: the @Offset parameter should use one-based indexing for this rather than the normal zero-based indexing.

JS map return object

If you want to alter the original objects, then a simple Array#forEach will do:

rockets.forEach(function(rocket) {
    rocket.launches += 10;
});

If you want to keep the original objects unaltered, then use Array#map and copy the objects using Object#assign:

var newRockets = rockets.forEach(function(rocket) {
    var newRocket = Object.assign({}, rocket);
    newRocket.launches += 10;
    return newRocket;
});

Is this a good way to clone an object in ES6?

EDIT: When this answer was posted, {...obj} syntax was not available in most browsers. Nowadays, you should be fine using it (unless you need to support IE 11).

Use Object.assign.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign

var obj = { a: 1 };
var copy = Object.assign({}, obj);
console.log(copy); // { a: 1 }

However, this won't make a deep clone. There is no native way of deep cloning as of yet.

EDIT: As @Mike 'Pomax' Kamermans mentioned in the comments, you can deep clone simple objects (ie. no prototypes, functions or circular references) using JSON.parse(JSON.stringify(input))

Mean filter for smoothing images in Matlab

h = fspecial('average', n);
filter2(h, img);

See doc fspecial: h = fspecial('average', n) returns an averaging filter. n is a 1-by-2 vector specifying the number of rows and columns in h.

Best way to do multi-row insert in Oracle?

Whenever I need to do this I build a simple PL/SQL block with a local procedure like this:

declare
   procedure ins
   is
      (p_exch_wh_key INTEGER, 
       p_exch_nat_key INTEGER, 
       p_exch_date DATE, exch_rate NUMBER, 
       p_from_curcy_cd VARCHAR2, 
       p_to_curcy_cd VARCHAR2, 
       p_exch_eff_date DATE, 
       p_exch_eff_end_date DATE, 
       p_exch_last_updated_date DATE);
   begin
      insert into tmp_dim_exch_rt 
      (exch_wh_key, 
       exch_nat_key, 
       exch_date, exch_rate, 
       from_curcy_cd, 
       to_curcy_cd, 
       exch_eff_date, 
       exch_eff_end_date, 
       exch_last_updated_date) 
      values
      (p_exch_wh_key, 
       p_exch_nat_key, 
       p_exch_date, exch_rate, 
       p_from_curcy_cd, 
       p_to_curcy_cd, 
       p_exch_eff_date, 
       p_exch_eff_end_date, 
       p_exch_last_updated_date);
   end;
begin
   ins (1, 1, '28-AUG-2008', 109.49, 'USD', 'JPY', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008'),
   ins (2, 1, '28-AUG-2008', .54, 'USD', 'GBP', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008'),
   ins (3, 1, '28-AUG-2008', 1.05, 'USD', 'CAD', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008'),
   ins (4, 1, '28-AUG-2008', .68, 'USD', 'EUR', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008'),
   ins (5, 1, '28-AUG-2008', 1.16, 'USD', 'AUD', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008'),
   ins (6, 1, '28-AUG-2008', 7.81, 'USD', 'HKD', '28-AUG-2008', '28-AUG-2008', '28-AUG-2008');
end;
/

Rotate a div using javascript

I recently had to build something similar. You can check it out in the snippet below.

The version I had to build uses the same button to start and stop the spinner, but you can manipulate to code if you have a button to start the spin and a different button to stop the spin

Basically, my code looks like this...

Run Code Snippet

_x000D_
_x000D_
var rocket = document.querySelector('.rocket');_x000D_
var btn = document.querySelector('.toggle');_x000D_
var rotate = false;_x000D_
var runner;_x000D_
var degrees = 0;_x000D_
_x000D_
function start(){_x000D_
    runner = setInterval(function(){_x000D_
        degrees++;_x000D_
        rocket.style.webkitTransform = 'rotate(' + degrees + 'deg)';_x000D_
    },50)_x000D_
}_x000D_
_x000D_
function stop(){_x000D_
    clearInterval(runner);_x000D_
}_x000D_
_x000D_
btn.addEventListener('click', function(){_x000D_
    if (!rotate){_x000D_
        rotate = true;_x000D_
        start();_x000D_
    } else {_x000D_
        rotate = false;_x000D_
        stop();_x000D_
    }_x000D_
})
_x000D_
body {_x000D_
  background: #1e1e1e;_x000D_
}    _x000D_
_x000D_
.rocket {_x000D_
    width: 150px;_x000D_
    height: 150px;_x000D_
    margin: 1em;_x000D_
    border: 3px dashed teal;_x000D_
    border-radius: 50%;_x000D_
    background-color: rgba(128,128,128,0.5);_x000D_
    display: flex;_x000D_
    justify-content: center;_x000D_
    align-items: center;_x000D_
  }_x000D_
  _x000D_
  .rocket h1 {_x000D_
    margin: 0;_x000D_
    padding: 0;_x000D_
    font-size: .8em;_x000D_
    color: skyblue;_x000D_
    letter-spacing: 1em;_x000D_
    text-shadow: 0 0 10px black;_x000D_
  }_x000D_
  _x000D_
  .toggle {_x000D_
    margin: 10px;_x000D_
    background: #000;_x000D_
    color: white;_x000D_
    font-size: 1em;_x000D_
    padding: .3em;_x000D_
    border: 2px solid red;_x000D_
    outline: none;_x000D_
    letter-spacing: 3px;_x000D_
  }
_x000D_
<div class="rocket"><h1>SPIN ME</h1></div>_x000D_
<button class="toggle">I/0</button>
_x000D_
_x000D_
_x000D_

Skip first line(field) in loop using CSV file?

Probably you want something like:

firstline = True
for row in kidfile:
    if firstline:    #skip first line
        firstline = False
        continue
    # parse the line

An other way to achive the same result is calling readline before the loop:

kidfile.readline()   # skip the first line
for row in kidfile:
    #parse the line

How to get hex color value rather than RGB value?

Updated @ErickPetru for rgba compatibility:

function rgb2hex(rgb) {
    rgb = rgb.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+))?\)$/);
    function hex(x) {
        return ("0" + parseInt(x).toString(16)).slice(-2);
    }
    return "#" + hex(rgb[1]) + hex(rgb[2]) + hex(rgb[3]);
}

I updated the regex to match the alpha value if defined, but not use it.

access key and value of object using *ngFor

You could create a custom pipe to return the list of key for each element. Something like that:

import { PipeTransform, Pipe } from '@angular/core';

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (let key in value) {
      keys.push(key);
    }
    return keys;
  }
}

and use it like that:

<tr *ngFor="let c of content">           
  <td *ngFor="let key of c | keys">{{key}}: {{c[key]}}</td>
</tr>

Edit

You could also return an entry containing both key and value:

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (let key in value) {
      keys.push({key: key, value: value[key]});
    }
    return keys;
  }
}

and use it like that:

<span *ngFor="let entry of content | keys">           
  Key: {{entry.key}}, value: {{entry.value}}
</span>

XMLHttpRequest status 0 (responseText is empty)

To see what the problem is, when you get the cryptic error 0 go to ... | More Tools | Developer Tools (Ctrl+Shift+I) in Chrome (on the page giving the error)

Read the red text in the log to get the true error message. If there is too much in there, right-click and Clear Console, then do your last request again.

My first problem was, I was passing in Authorization headers to my own cross-domain web service for the browser for the first time.

I already had:

Access-Control-Allow-Origin: *

But not:

Access-Control-Allow-Methods: GET, POST, PUT, DELETE
Access-Control-Allow-Headers: Authorization

in the response header of my web service.

After I added that, my error zero was gone from my own web server, as well as when running the index.html file locally without a web server, but was still giving errors in code pen.

Back to ... | More Tools | Developer Tools while getting the error in codepen, and there is clearly explained: codepen uses https, so I cannot make calls to http, as the security is lower.

I need to therefore host my web service on https.

Knowing how to get the true error message - priceless!

How to open adb and use it to send commands

The adb tool can be found in sdk/platform-tools/

If you don't see this directory in your SDK, launch the SDK Manager and install "Android SDK Platform-tools"

Also update your PATH environment variable to include the platform-tools/ directory, so you can execute adb from any location.

Drawing Circle with OpenGL

glBegin(GL_POLYGON);                        // Middle circle
double radius = 0.2;
double ori_x = 0.0;                         // the origin or center of circle
double ori_y = 0.0;
for (int i = 0; i <= 300; i++) {
    double angle = 2 * PI * i / 300;
    double x = cos(angle) * radius;
    double y = sin(angle) * radius;
    glVertex2d(ori_x + x, ori_y + y);
}
glEnd();

How do I run .sh or .bat files from Terminal?

I had this problem for *.sh files in Yosemite and couldn't figure out what the correct path is for a folder on my Desktop...after some gnashing of teeth, dragged the file itself into the Terminal window; hey presto!!

How do I write a Python dictionary to a csv file?

Your code was very close to working.

Try using a regular csv.writer rather than a DictWriter. The latter is mainly used for writing a list of dictionaries.

Here's some code that writes each key/value pair on a separate row:

import csv

somedict = dict(raymond='red', rachel='blue', matthew='green')
with open('mycsvfile.csv','wb') as f:
    w = csv.writer(f)
    w.writerows(somedict.items())

If instead you want all the keys on one row and all the values on the next, that is also easy:

with open('mycsvfile.csv','wb') as f:
    w = csv.writer(f)
    w.writerow(somedict.keys())
    w.writerow(somedict.values())

Pro tip: When developing code like this, set the writer to w = csv.writer(sys.stderr) so you can more easily see what is being generated. When the logic is perfected, switch back to w = csv.writer(f).

Notice: Undefined variable: _SESSION in "" on line 9

Add

session_start();

at the beginning of your page before any HTML

You will have something like :

<?php session_start();
include("inc/incfiles/header.inc.php")?>
<html>
<head>
<meta http-equiv="Content-Type" conte...

Don't forget to remove the space you have before

How to convert a string with Unicode encoding to a string of letters

Fast

 fun unicodeDecode(unicode: String): String {
        val stringBuffer = StringBuilder()
        var i = 0
        while (i < unicode.length) {
            if (i + 1 < unicode.length)
                if (unicode[i].toString() + unicode[i + 1].toString() == "\\u") {
                    val symbol = unicode.substring(i + 2, i + 6)
                    val c = Integer.parseInt(symbol, 16)
                    stringBuffer.append(c.toChar())
                    i += 5
                } else stringBuffer.append(unicode[i])
            i++
        }
        return stringBuffer.toString()
    }

How do you obtain a Drawable object from a resource id in android package?

best way is

 button.setBackgroundResource(android.R.drawable.ic_delete);

OR this for Drawable left and something like that for right etc.

int imgResource = R.drawable.left_img;
button.setCompoundDrawablesWithIntrinsicBounds(imgResource, 0, 0, 0);

and

getResources().getDrawable() is now deprecated

Can .NET load and parse a properties file equivalent to Java Properties class?

Final class. Thanks @eXXL.

public class Properties
{
    private Dictionary<String, String> list;
    private String filename;

    public Properties(String file)
    {
        reload(file);
    }

    public String get(String field, String defValue)
    {
        return (get(field) == null) ? (defValue) : (get(field));
    }
    public String get(String field)
    {
        return (list.ContainsKey(field))?(list[field]):(null);
    }

    public void set(String field, Object value)
    {
        if (!list.ContainsKey(field))
            list.Add(field, value.ToString());
        else
            list[field] = value.ToString();
    }

    public void Save()
    {
        Save(this.filename);
    }

    public void Save(String filename)
    {
        this.filename = filename;

        if (!System.IO.File.Exists(filename))
            System.IO.File.Create(filename);

        System.IO.StreamWriter file = new System.IO.StreamWriter(filename);

        foreach(String prop in list.Keys.ToArray())
            if (!String.IsNullOrWhiteSpace(list[prop]))
                file.WriteLine(prop + "=" + list[prop]);

        file.Close();
    }

    public void reload()
    {
        reload(this.filename);
    }

    public void reload(String filename)
    {
        this.filename = filename;
        list = new Dictionary<String, String>();

        if (System.IO.File.Exists(filename))
            loadFromFile(filename);
        else
            System.IO.File.Create(filename);
    }

    private void loadFromFile(String file)
    {
        foreach (String line in System.IO.File.ReadAllLines(file))
        {
            if ((!String.IsNullOrEmpty(line)) &&
                (!line.StartsWith(";")) &&
                (!line.StartsWith("#")) &&
                (!line.StartsWith("'")) &&
                (line.Contains('=')))
            {
                int index = line.IndexOf('=');
                String key = line.Substring(0, index).Trim();
                String value = line.Substring(index + 1).Trim();

                if ((value.StartsWith("\"") && value.EndsWith("\"")) ||
                    (value.StartsWith("'") && value.EndsWith("'")))
                {
                    value = value.Substring(1, value.Length - 2);
                }

                try
                {
                    //ignore dublicates
                    list.Add(key, value);
                }
                catch { }
            }
        }
    }


}

Sample use:

//load
Properties config = new Properties(fileConfig);
//get value whith default value
com_port.Text = config.get("com_port", "1");
//set value
config.set("com_port", com_port.Text);
//save
config.Save()

Programmatically navigate using react router V4

TL;DR:

if (navigate) {
  return <Redirect to="/" push={true} />
}

The simple and declarative answer is that you need to use <Redirect to={URL} push={boolean} /> in combination with setState()

push: boolean - when true, redirecting will push a new entry onto the history instead of replacing the current one.


import { Redirect } from 'react-router'

class FooBar extends React.Component {
  state = {
    navigate: false
  }

  render() {
    const { navigate } = this.state

    // here is the important part
    if (navigate) {
      return <Redirect to="/" push={true} />
    }
   // ^^^^^^^^^^^^^^^^^^^^^^^

    return (
      <div>
        <button onClick={() => this.setState({ navigate: true })}>
          Home
        </button>
      </div>
    )
  }
}

Full example here. Read more here.

PS. The example uses ES7+ Property Initializers to initialise state. Look here as well, if you're interested.

How disable / remove android activity label and label bar?

public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  

        //set up notitle 
        requestWindowFeature(Window.FEATURE_NO_TITLE);  
        //set up full screen
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,   
                WindowManager.LayoutParams.FLAG_FULLSCREEN);  

        setContentView(R.layout.main);  
} 

Get Maven artifact version at runtime

Here's a method for getting the version from the pom.properties, falling back to getting it from the manifest

public synchronized String getVersion() {
    String version = null;

    // try to load from maven properties first
    try {
        Properties p = new Properties();
        InputStream is = getClass().getResourceAsStream("/META-INF/maven/com.my.group/my-artefact/pom.properties");
        if (is != null) {
            p.load(is);
            version = p.getProperty("version", "");
        }
    } catch (Exception e) {
        // ignore
    }

    // fallback to using Java API
    if (version == null) {
        Package aPackage = getClass().getPackage();
        if (aPackage != null) {
            version = aPackage.getImplementationVersion();
            if (version == null) {
                version = aPackage.getSpecificationVersion();
            }
        }
    }

    if (version == null) {
        // we could not compute the version so use a blank
        version = "";
    }

    return version;
} 

Insert Data Into Tables Linked by Foreign Key

You can do it in one sql statement for existing customers, 3 statements for new ones. All you have to do is be an optimist and act as though the customer already exists:

insert into "order" (customer_id, price) values \
((select customer_id from customer where name = 'John'), 12.34);

If the customer does not exist, you'll get an sql exception which text will be something like:

null value in column "customer_id" violates not-null constraint

(providing you made customer_id non-nullable, which I'm sure you did). When that exception occurs, insert the customer into the customer table and redo the insert into the order table:

insert into customer(name) values ('John');
insert into "order" (customer_id, price) values \
((select customer_id from customer where name = 'John'), 12.34);

Unless your business is growing at a rate that will make "where to put all the money" your only real problem, most of your inserts will be for existing customers. So, most of the time, the exception won't occur and you'll be done in one statement.

ASP.NET email validator regex

We can use RegularExpressionValidator to validate email address format. You need to specify the regular expression in ValidationExpression property of RegularExpressionValidator. So it will look like

 <asp:RegularExpressionValidator ID="validateEmail"    
  runat="server" ErrorMessage="Invalid email."
  ControlToValidate="txtEmail" 
  ValidationExpression="^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$" />

Also in event handler of button or link you need to check !Page.IsValid. Check sample code here : sample code

Also if you don't want to use RegularExpressionValidator you can write simple validate method and in that method usinf RegEx class of System.Text.RegularExpressions namespace.

Check example:

example

Is there a way to override class variables in Java?

Just Call super.variable in sub class constructor

public abstract class Beverage {

int cost;


int getCost() {

    return cost;

}

}`

public class Coffee extends Beverage {


int cost = 10;
Coffee(){
    super.cost = cost;
}


}`

public class Driver {

public static void main(String[] args) {

    Beverage coffee = new Coffee();

    System.out.println(coffee.getCost());

}

}

Output is 10.

How to enable NSZombie in Xcode?

In Xcode 4.5.2 goto Product -> Edit Scheme -> and Under the Diagnostics tab check the check box in between Objective C and Enable Zombie Objects and Click on OK

How to show a running progress bar while page is loading

In this sample, I created a JavaScript progress bar (with percentage display), you can control it and hide it with JavaScript.

In this sample, the progress bar advances every 100ms. You can see it in JSFiddle

var elapsedTime = 0;
var interval = setInterval(function() {
  timer()
}, 100);

function progressbar(percent) {
  document.getElementById("prgsbarcolor").style.width = percent + '%';
  document.getElementById("prgsbartext").innerHTML = percent + '%';
}

function timer() {
  if (elapsedTime > 100) {
    document.getElementById("prgsbartext").style.color = "#FFF";
    document.getElementById("prgsbartext").innerHTML = "Completed.";
    if (elapsedTime >= 107) {
      clearInterval(interval);
      history.go(-1);
    }
  } else {
    progressbar(elapsedTime);
  }
  elapsedTime++;
}

Bootstrap date and time picker

If you are still interested in a javascript api to select both date and time data, have a look at these projects which are forks of bootstrap datepicker:

The first fork is a big refactor on the parsing/formatting codebase and besides providing all views to select date/time using mouse/touch, it also has a mask option (by default) which lets the user to quickly type the date/time based on a pre-specified format.

How to concatenate strings in windows batch file for loop?

In batch you could do it like this:

@echo off

setlocal EnableDelayedExpansion

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do (
  set "var=%%sxyz"
  svn co "!var!"
)

If you don't need the variable !var! elsewhere in the loop, you could simplify that to

@echo off

setlocal

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do svn co "%%sxyz"

However, like C.B. I'd prefer PowerShell if at all possible:

$string_list = 'str1', 'str2', 'str3', ... 'str10'

$string_list | ForEach-Object {
  $var = "${_}xyz"   # alternatively: $var = $_ + 'xyz'
  svn co $var
}

Again, this could be simplified if you don't need $var elsewhere in the loop:

$string_list = 'str1', 'str2', 'str3', ... 'str10'
$string_list | ForEach-Object { svn co "${_}xyz" }

Running Selenium Webdriver with a proxy in Python

As stated by @Dugini, some config entries have been removed. Maximal:

webdriver.DesiredCapabilities.FIREFOX['proxy'] = {
    "httpProxy":PROXY,
    "ftpProxy":PROXY,
    "sslProxy":PROXY,
    "noProxy":[],
    "proxyType":"MANUAL"
 }

How can I get enum possible values in a MySQL database?

The problem with every other answer in this thread is that none of them properly parse all special cases of the strings within the enum.

The biggest special case character that was throwing me for a loop was single quotes, as they are encoded themselves as 2 single quotes together! So, for example, an enum with the value 'a' is encoded as enum('''a'''). Horrible, right?

Well, the solution is to use MySQL to parse the data for you!

Since everyone else is using PHP in this thread, that is what I will use. Following is the full code. I will explain it after. The parameter $FullEnumString will hold the entire enum string, extracted from whatever method you want to use from all the other answers. RunQuery() and FetchRow() (non associative) are stand ins for your favorite DB access methods.

function GetDataFromEnum($FullEnumString)
{
    if(!preg_match('/^enum\((.*)\)$/iD', $FullEnumString, $Matches))
        return null;
    return FetchRow(RunQuery('SELECT '.$Matches[1]));
}

preg_match('/^enum\((.*)\)$/iD', $FullEnumString, $Matches) confirms that the enum value matches what we expect, which is to say, "enum(".$STUFF.")" (with nothing before or after). If the preg_match fails, NULL is returned.

This preg_match also stores the list of strings, escaped in weird SQL syntax, in $Matches[1]. So next, we want to be able to get the real data out of that. So you just run "SELECT ".$Matches[1], and you have a full list of the strings in your first record!

So just pull out that record with a FetchRow(RunQuery(...)) and you’re done.

If you wanted to do this entire thing in SQL, you could use the following

SET @TableName='your_table_name', @ColName='your_col_name';
SET @Q=(SELECT CONCAT('SELECT ', (SELECT SUBSTR(COLUMN_TYPE, 6, LENGTH(COLUMN_TYPE)-6) FROM information_schema.COLUMNS WHERE TABLE_NAME=@TableName AND COLUMN_NAME=@ColName)));
PREPARE stmt FROM @Q;
EXECUTE stmt;

P.S. To preempt anyone from saying something about it, no, I do not believe this method can lead to SQL injection.

Convert a String In C++ To Upper Case

Short solution using C++11 and toupper().

for (auto & c: str) c = toupper(c);

How to send a “multipart/form-data” POST in Android with Volley

Another solution, very light with high performance with payload large:

Android Asynchronous Http Client library: http://loopj.com/android-async-http/

private static AsyncHttpClient client = new AsyncHttpClient();

private void uploadFileExecute(File file) {

    RequestParams params = new RequestParams();

    try { params.put("photo", file); } catch (FileNotFoundException e) {}

    client.post(getUrl(), params,

        new AsyncHttpResponseHandler() {

            public void onSuccess(String result) {

                Log.d(TAG,"uploadFile response: "+result);

            };

            public void onFailure(Throwable arg0, String errorMsg) {

                Log.d(TAG,"uploadFile ERROR!");

            };

        }

    );

}

How to make a launcher

Just develop a normal app and then add a couple of lines to the app's manifest file.

First you need to add the following attribute to your activity:

            android:launchMode="singleTask"

Then add two categories to the intent filter :

            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.HOME" />

The result could look something like this:

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.dummy.app"
        android:versionCode="1"
        android:versionName="1.0" >

        <uses-sdk
            android:minSdkVersion="11"
            android:targetSdkVersion="19" />

        <application
            android:allowBackup="true"
            android:icon="@drawable/ic_launcher"
            android:label="@string/app_name"
            android:theme="@style/AppTheme" >
            <activity
                android:name="com.dummy.app.MainActivity"
                android:launchMode="singleTask"
                android:label="@string/app_name" >
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
                    <category android:name="android.intent.category.LAUNCHER" />
                    <category android:name="android.intent.category.DEFAULT" />
                    <category android:name="android.intent.category.HOME" />
                </intent-filter>
            </activity>
        </application>

    </manifest>

It's that simple!

Create table with jQuery - append

It is important to note that you could use Emmet to achieve the same result. First, check what Emmet can do for you at https://emmet.io/

In a nutshell, with Emmet, you can expand a string into a complexe HTML markup as shown in the examples below:

Example #1

ul>li*5

... will produce

<ul>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
    <li></li>
</ul>

Example #2

div#header+div.page+div#footer.class1.class2.class3

... will produce

<div id="header"></div>
<div class="page"></div>
<div id="footer" class="class1 class2 class3"></div>

And list goes on. There are more examples at https://docs.emmet.io/abbreviations/syntax/

And there is a library for doing that using jQuery. It's called Emmet.js and available at https://github.com/christiansandor/Emmet.js

Image height and width not working?

You have a class on your CSS that is overwriting your width and height, the class reads as such:

.postItem img {
    height: auto;
    width: 450px;
}

Remove that and your width/height properties on the img tag should work.

Get file path of image on Android

Simple Pass Intent first

Intent i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, RESULT_LOAD_IMAGE);

And u will get picture path on u onActivityResult

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) {
            Uri selectedImage = data.getData();
            String[] filePathColumn = { MediaStore.Images.Media.DATA };
            Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
            cursor.moveToFirst();
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String picturePath = cursor.getString(columnIndex);
            cursor.close();
            ImageView imageView = (ImageView) findViewById(R.id.imgView);
            imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
        }
    }

TypeError: You provided an invalid object where a stream was expected. You can provide an Observable, Promise, Array, or Iterable

In my case in Angular-5, service file was not imported from which i was accessing the method and subscribing the data.After importing service file it worked fine.

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

How do you redirect HTTPS to HTTP?

all the above did not work when i used cloudflare, this one worked for me:

RewriteCond %{HTTP:X-Forwarded-Proto} =https
RewriteRule ^(.*)$ http://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

and this one definitely works without proxies in the way:

RewriteCond %{HTTPS} on
RewriteRule (.*) http://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

how to take user input in Array using java?

**How to accept array by user Input

Answer:-

import java.io.*;

import java.lang.*;

class Reverse1  {

   public static void main(String args[]) throws IOException {

     int a[]=new int[25];

     int num=0,i=0;

     BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

     System.out.println("Enter the Number of element");

     num=Integer.parseInt(br.readLine());

     System.out.println("Enter the array");

     for(i=1;i<=num;i++) {
        a[i]=Integer.parseInt(br.readLine());
     }

     for(i=num;i>=1;i--) {
        System.out.println(a[i]);    
     }

   }

}

How to add custom Http Header for C# Web Service Client consuming Axis 1.4 Web service

user334291's answer was a life saver for me. Just want to add how you can add what the OP originally intended to do (what I ended up using):

Overriding the GetWebRequest function on the generated webservice code:

protected override System.Net.WebRequest GetWebRequest(Uri uri)
{
    System.Net.WebRequest request = base.GetWebRequest(uri);          
    string auth = "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(this.Credentials.GetCredential(uri, "Basic").UserName + ":" + this.Credentials.GetCredential(uri, "Basic").Password));
    request.Headers.Add("Authorization", auth);
    return request;
}

and setting the credentials before calling the webservice:

  client.Credentials = new NetworkCredential(user, password);       

Read a file in Node.js

var fs = require('fs');
var path = require('path');

exports.testDir = path.dirname(__filename);
exports.fixturesDir = path.join(exports.testDir, 'fixtures');
exports.libDir = path.join(exports.testDir, '../lib');
exports.tmpDir = path.join(exports.testDir, 'tmp');
exports.PORT = +process.env.NODE_COMMON_PORT || 12346;

// Read File
fs.readFile(exports.tmpDir+'/start.html', 'utf-8', function(err, content) {
  if (err) {
    got_error = true;
  } else {
    console.log('cat returned some content: ' + content);
    console.log('this shouldn\'t happen as the file doesn\'t exist...');
    //assert.equal(true, false);
  }
});

CSS transition between left -> right and top -> bottom positions

In more modern browsers (including IE 10+) you can now use calc():

.moveto {
  top: 0px;
  left: calc(100% - 50px);
}

Java Thread Example?

A simple example:

public class Test extends Thread {
    public synchronized void run() {
        for (int i = 0; i <= 10; i++) {
            System.out.println("i::"+i);
        }
    }

    public static void main(String[] args) {
        Test obj = new Test();

        Thread t1 = new Thread(obj);
        Thread t2 = new Thread(obj);
        Thread t3 = new Thread(obj);

        t1.start();
        t2.start();
        t3.start();
    }
}

How to remove/delete a large file from commit history in Git repository?

I basically did what was on this answer: https://stackoverflow.com/a/11032521/1286423

(for history, I'll copy-paste it here)

$ git filter-branch --index-filter "git rm -rf --cached --ignore-unmatch YOURFILENAME" HEAD
$ rm -rf .git/refs/original/ 
$ git reflog expire --all 
$ git gc --aggressive --prune
$ git push origin master --force

It didn't work, because I like to rename and move things a lot. So some big file were in folders that have been renamed, and I think the gc couldn't delete the reference to those files because of reference in tree objects pointing to those file. My ultimate solution to really kill it was to:

# First, apply what's in the answer linked in the front
# and before doing the gc --prune --aggressive, do:

# Go back at the origin of the repository
git checkout -b newinit <sha1 of first commit>
# Create a parallel initial commit
git commit --amend
# go back on the master branch that has big file
# still referenced in history, even though 
# we thought we removed them.
git checkout master
# rebase on the newinit created earlier. By reapply patches,
# it will really forget about the references to hidden big files.
git rebase newinit

# Do the previous part (checkout + rebase) for each branch
# still connected to the original initial commit, 
# so we remove all the references.

# Remove the .git/logs folder, also containing references
# to commits that could make git gc not remove them.
rm -rf .git/logs/

# Then you can do a garbage collection,
# and the hidden files really will get gc'ed
git gc --prune --aggressive

My repo (the .git) changed from 32MB to 388KB, that even filter-branch couldn't clean.

jquery can't get data attribute value

jQuery's data() method will give you access to data-* attributes, BUT, it clobbers the case of the attribute name. You can either use this:

$('#myButton').data("x10") // note the lower case

Or, you can use the attr() method, which preserves your case:

$('#myButton').attr("data-X10")

Try both methods here: http://jsfiddle.net/q5rbL/

Be aware that these approaches are not completely equivalent. If you will change the data-* attribute of an element, you should use attr(). data() will read the value once initially, then continue to return a cached copy, whereas attr() will re-read the attribute each time.

Note that jQuery will also convert hyphens in the attribute name to camel case (source -- i.e. data-some-data == $(ele).data('someData')). Both of these conversions are in conformance with the HTML specification, which dictates that custom data attributes should contain no uppercase letters, and that hyphens will be camel-cased in the dataset property (source). jQuery's data method is merely mimicking/conforming to this standard behavior.

Documentation

Bash script to run php script

a quick way to find out WHERE YOUR particular executable is located on your $PATH, try.

Even quicker way to find out where php is ...

whereis php

I'm running debian and above command showing me

php: /usr/bin/php /usr/share/php /usr/share/man/man1/php.1.gz

Hope that helps.

Saving a high resolution image in R

A simpler way is

ggplot(data=df, aes(x=xvar, y=yvar)) + 
geom_point()

ggsave(path = path, width = width, height = height, device='tiff', dpi=700)

Moment.js get day name from date

With moment you can parse the date string you have:

var dt = moment(myDate.date, "YYYY-MM-DD HH:mm:ss")

That's for UTC, you'll have to convert the time zone from that point if you so desire.

Then you can get the day of the week:

dt.format('dddd');

add item to dropdown list in html using javascript

Try to use appendChild method:

select.appendChild(option);

Maven build failed: "Unable to locate the Javac Compiler in: jre or jdk issue"

I had the same error, because of the JUnit version. I had three 3.8.1, and I have changed to 4.8.1.

So the solution is:

You have to go to the POM, and make sure that you dependency looks like this

<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <version>4.8.1</version>
  <scope>test</scope>
</dependency>

How can I divide two integers stored in variables in Python?

if 'a' is already a decimal; adding '.' would make 3.4/b(for example) into 3.4./b

Try float(a)/b

Passing an array as parameter in JavaScript

It is possible to pass arrays to functions, and there are no special requirements for dealing with them. Are you sure that the array you are passing to to your function actually has an element at [0]?

PHP $_SERVER['HTTP_HOST'] vs. $_SERVER['SERVER_NAME'], am I understanding the man pages correctly?

The major difference between the two is that $_SERVER['SERVER_NAME'] is a server controlled variable, while $_SERVER['HTTP_HOST'] is a user-controlled value.

The rule of thumb is to never trust values from the user, so $_SERVER['SERVER_NAME'] is the better choice.

As Gumbo pointed out, Apache will construct SERVER_NAME from user-supplied values if you don't set UseCanonicalName On.

Edit: Having said all that, if the site is using a name-based virtual host, the HTTP Host header is the only way to reach sites that aren't the default site.

What is a good alternative to using an image map generator?

There is also Mappa - http://mappatool.com/.

It only supports polygons, but they are definitely the hardest parts :)

Debugging with command-line parameters in Visual Studio

The Mozilla.org FAQ on debugging Mozilla on Windows is of interest here.

In short, the Visual Studio debugger can be invoked on a program from the command line, allowing one to specify the command line arguments when invoking a command line program, directly on the command line.

This looks like the following for Visual Studio 8 or 9 (Visual Studio 2005 or Visual Studio 2008, respectively)

  devenv /debugexe 'program name' 'program arguments'

It is also possible to have an explorer action to start a program in the Visual Studio debugger.

Where can I find the API KEY for Firebase Cloud Messaging?

You can also get the API key in the android studio. Switch to Project view in android then find the google-services.json. Scroll down and you will find the api_key

Border length smaller than div width?

Another way to do this (in modern browsers) is with a negative spread box-shadow. Check out this updated fiddle: http://jsfiddle.net/WuZat/290/

box-shadow: 0px 24px 3px -24px magenta;

I think the safest and most compatible way is the accepted answer above, though. Just thought I'd share another technique.

Disable activity slide-in animation when launching new activity?

I'm on 4.4.2, and calling overridePendingTransition(0, 0) in the launching activity's onCreate() will disable the starting animation (calling overridePendingTransition(0, 0) immediately after startActivity() did NOT work). As noted in another answer, calling overridePendingTransition(0, 0) after finish() disables the closing animation.

Btw, I found that setting the style with "android:windowAnimationStyle">@null (another answer mentioned here) caused a crash when my launching activity tried to set the action bar title. Debugging further, I discovered that somehow this causes window.hasFeature(Window.FEATURE_ACTION_BAR) to fail in the Activity's initActionBar().

Check for file exists or not in sql server?

Not tested but you can try something like this :

Declare @count as int
Set @count=1
Declare @inputFile varchar(max)
Declare @Sample Table
(id int,filepath varchar(max) ,Isexists char(3))

while @count<(select max(id) from yourTable)
BEGIN
Set @inputFile =(Select filepath from yourTable where id=@count)
DECLARE @isExists INT
exec master.dbo.xp_fileexist @inputFile , 
@isExists OUTPUT
insert into @Sample
Select @count,@inputFile ,case @isExists 
when 1 then 'Yes' 
else 'No' 
end as isExists
set @count=@count+1
END

How to return first 5 objects of Array in Swift?

Swift 4

To get the first N elements of a Swift array you can use prefix(_ maxLength: Int):

Array(largeArray.prefix(5))

How to check a Long for null in java

If the longValue variable is of type Long (the wrapper class, not the primitive long), then yes you can check for null values.

A primitive variable needs to be initialized to some value explicitly (e.g. to 0) so its value will never be null.

Is it possible to declare a public variable in vba and assign a default value?

Just to offer you a different angle -

I find it's not a good idea to maintain public variables between function calls. Any variables you need to use should be stored in Subs and Functions and passed as parameters. Once the code is done running, you shouldn't expect the VBA Project to maintain the values of any variables.

The reason for this is that there is just a huge slew of things that can inadvertently reset the VBA Project while using the workbook. When this happens, any public variables get reset to 0.

If you need a value to be stored outside of your subs and functions, I highly recommend using a hidden worksheet with named ranges for any information that needs to persist.

Opening Android Settings programmatically

In case anyone finds this question and you want to open up settings for your specific application:

    val intent = Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS)
    intent.data = Uri.parse("package:" + context.packageName)
    startActivity(intent)

IE8 support for CSS Media Query

Media queries are not supported at all in IE8 and below.


A Javascript based workaround

To add support for IE8, you could use one of several JS solutions. For example, Respond can be added to add media query support for IE8 only with the following code :

<!--[if lt IE 9]>
<script 
   src="respond.min.js">
</script>
<![endif]-->

CSS Mediaqueries is another library that does the same thing. The code for adding that library to your HTML would be identical :

<!--[if lt IE 9]>
<script 
   src="css3-mediaqueries.js">
</script>
<![endif]-->

The alternative

If you don't like a JS based solution, you should also consider adding an IE<9 only stylesheet where you adjust your styling specific to IE<9. For that, you should add the following HTML to your code:

<!--[if lt IE 9]>
<link rel="stylesheet" type="text/css" media="all" href="style-ielt9.css"/>
<![endif]-->

Note :

Technically it's one more alternative: using CSS hacks to target IE<9. It has the same impact as an IE<9 only stylesheet, but you don't need a seperate stylesheet for that. I do not recommend this option, though, as they produce invalid CSS code (which is but one of several reasons why the use of CSS hacks is generally frowned upon today).

[Vue warn]: Cannot find element

The simple thing is to put the script below the document, just before your closing </body> tag:

<body>
   <div id="main">
      <div id="mainActivity" v-component="{{currentActivity}}" class="activity"></div>
   </div>
   <script src="app.js"></script>
</body>

app.js file:

var main = new Vue({
    el: '#main',
    data: {
        currentActivity: 'home'
    }
});

Spark - Error "A master URL must be set in your configuration" when submitting an app

The TLDR:

.config("spark.master", "local")

a list of the options for spark.master in spark 2.2.1

I ended up on this page after trying to run a simple Spark SQL java program in local mode. To do this, I found that I could set spark.master using:

SparkSession spark = SparkSession
.builder()
.appName("Java Spark SQL basic example")
.config("spark.master", "local")
.getOrCreate();

An update to my answer:

To be clear, this is not what you should do in a production environment. In a production environment, spark.master should be specified in one of a couple other places: either in $SPARK_HOME/conf/spark-defaults.conf (this is where cloudera manager will put it), or on the command line when you submit the app. (ex spark-submit --master yarn).

If you specify spark.master to be 'local' in this way, spark will try to run in a single jvm, as indicated by the comments below. If you then try to specify --deploy-mode cluster, you will get an error 'Cluster deploy mode is not compatible with master "local"'. This is because setting spark.master=local means that you are NOT running in cluster mode.

Instead, for a production app, within your main function (or in functions called by your main function), you should simply use:

SparkSession
.builder()
.appName("Java Spark SQL basic example")
.getOrCreate();

This will use the configurations specified on the command line/in config files.

Also, to be clear on this too: --master and "spark.master" are the exact same parameter, just specified in different ways. Setting spark.master in code, like in my answer above, will override attempts to set --master, and will override values in spark-defaults.conf, so don't do it in production. Its great for tests though.

also, see this answer. which links to a list of the options for spark.master and what each one actually does.

a list of the options for spark.master in spark 2.2.1

How to create threads in nodejs

Every node.js process is single threaded by design. Therefore to get multiple threads, you have to have multiple processes (As some other posters have pointed out, there are also libraries you can link to that will give you the ability to work with threads in Node, but no such capability exists without those libraries. See answer by Shawn Vincent referencing https://github.com/audreyt/node-webworker-threads)

You can start child processes from your main process as shown here in the node.js documentation: http://nodejs.org/api/child_process.html. The examples are pretty good on this page and are pretty straight forward.

Your parent process can then watch for the close event on any process it started and then could force close the other processes you started to achieve the type of one fail all stop strategy you are talking about.

Also see: Node.js on multi-core machines

Convert array into csv

Well maybe a little late after 4 years haha... but I was looking for solution to do OBJECT to CSV, however most solutions here is actually for ARRAY to CSV...

After some tinkering, here is my solution to convert object into CSV, I think is pretty neat. Hope this would help someone else.

$resp = array();
foreach ($entries as $entry) {
    $row = array();
    foreach ($entry as $key => $value) {
        array_push($row, $value);
    }
    array_push($resp, implode(',', $row));
}
echo implode(PHP_EOL, $resp);

Note that for the $key => $value to work, your object's attributes must be public, the private ones will not get fetched.

The end result is that you get something like this:

blah,blah,blah
blah,blah,blah

Using HTML5 file uploads with AJAX and jQuery

With jQuery (and without FormData API) you can use something like this:

function readFile(file){
   var loader = new FileReader();
   var def = $.Deferred(), promise = def.promise();

   //--- provide classic deferred interface
   loader.onload = function (e) { def.resolve(e.target.result); };
   loader.onprogress = loader.onloadstart = function (e) { def.notify(e); };
   loader.onerror = loader.onabort = function (e) { def.reject(e); };
   promise.abort = function () { return loader.abort.apply(loader, arguments); };

   loader.readAsBinaryString(file);

   return promise;
}

function upload(url, data){
    var def = $.Deferred(), promise = def.promise();
    var mul = buildMultipart(data);
    var req = $.ajax({
        url: url,
        data: mul.data,
        processData: false,
        type: "post",
        async: true,
        contentType: "multipart/form-data; boundary="+mul.bound,
        xhr: function() {
            var xhr = jQuery.ajaxSettings.xhr();
            if (xhr.upload) {

                xhr.upload.addEventListener('progress', function(event) {
                    var percent = 0;
                    var position = event.loaded || event.position; /*event.position is deprecated*/
                    var total = event.total;
                    if (event.lengthComputable) {
                        percent = Math.ceil(position / total * 100);
                        def.notify(percent);
                    }                    
                }, false);
            }
            return xhr;
        }
    });
    req.done(function(){ def.resolve.apply(def, arguments); })
       .fail(function(){ def.reject.apply(def, arguments); });

    promise.abort = function(){ return req.abort.apply(req, arguments); }

    return promise;
}

var buildMultipart = function(data){
    var key, crunks = [], bound = false;
    while (!bound) {
        bound = $.md5 ? $.md5(new Date().valueOf()) : (new Date().valueOf());
        for (key in data) if (~data[key].indexOf(bound)) { bound = false; continue; }
    }

    for (var key = 0, l = data.length; key < l; key++){
        if (typeof(data[key].value) !== "string") {
            crunks.push("--"+bound+"\r\n"+
                "Content-Disposition: form-data; name=\""+data[key].name+"\"; filename=\""+data[key].value[1]+"\"\r\n"+
                "Content-Type: application/octet-stream\r\n"+
                "Content-Transfer-Encoding: binary\r\n\r\n"+
                data[key].value[0]);
        }else{
            crunks.push("--"+bound+"\r\n"+
                "Content-Disposition: form-data; name=\""+data[key].name+"\"\r\n\r\n"+
                data[key].value);
        }
    }

    return {
        bound: bound,
        data: crunks.join("\r\n")+"\r\n--"+bound+"--"
    };
};

//----------
//---------- On submit form:
var form = $("form");
var $file = form.find("#file");
readFile($file[0].files[0]).done(function(fileData){
   var formData = form.find(":input:not('#file')").serializeArray();
   formData.file = [fileData, $file[0].files[0].name];
   upload(form.attr("action"), formData).done(function(){ alert("successfully uploaded!"); });
});

With FormData API you just have to add all fields of your form to FormData object and send it via $.ajax({ url: url, data: formData, processData: false, contentType: false, type:"POST"})

A warning - comparison between signed and unsigned integer expressions

I had the exact same problem yesterday working through problem 2-3 in Accelerated C++. The key is to change all variables you will be comparing (using Boolean operators) to compatible types. In this case, that means string::size_type (or unsigned int, but since this example is using the former, I will just stick with that even though the two are technically compatible).

Notice that in their original code they did exactly this for the c counter (page 30 in Section 2.5 of the book), as you rightly pointed out.

What makes this example more complicated is that the different padding variables (padsides and padtopbottom), as well as all counters, must also be changed to string::size_type.

Getting to your example, the code that you posted would end up looking like this:

cout << "Please enter the size of the frame between top and bottom";
string::size_type padtopbottom;
cin >> padtopbottom;

cout << "Please enter size of the frame from each side you would like: ";
string::size_type padsides; 
cin >> padsides;

string::size_type c = 0; // definition of c in the program

if (r == padtopbottom + 1 && c == padsides + 1) { // where the error no longer occurs

Notice that in the previous conditional, you would get the error if you didn't initialize variable r as a string::size_type in the for loop. So you need to initialize the for loop using something like:

    for (string::size_type r=0; r!=rows; ++r)   //If r and rows are string::size_type, no error!

So, basically, once you introduce a string::size_type variable into the mix, any time you want to perform a boolean operation on that item, all operands must have a compatible type for it to compile without warnings.

overlay two images in android to set an imageview

Its a bit late answer, but it covers merging images from urls using Picasso

MergeImageView

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Build;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.widget.ImageView;
import com.squareup.picasso.Picasso;

import java.io.IOException;
import java.util.List;

public class MergeImageView extends ImageView {

    private SparseArray<Bitmap> bitmaps = new SparseArray<>();
    private Picasso picasso;
    private final int DEFAULT_IMAGE_SIZE = 50;
    private int MIN_IMAGE_SIZE = DEFAULT_IMAGE_SIZE;
    private int MAX_WIDTH = DEFAULT_IMAGE_SIZE * 2, MAX_HEIGHT = DEFAULT_IMAGE_SIZE * 2;
    private String picassoRequestTag = null;

    public MergeImageView(Context context) {
        super(context);
    }

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

    public MergeImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public MergeImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    @Override
    public boolean isInEditMode() {
        return true;
    }

    public void clearResources() {
        if (bitmaps != null) {
            for (int i = 0; i < bitmaps.size(); i++)
                bitmaps.get(i).recycle();
            bitmaps.clear();
        }
        // cancel picasso requests
        if (picasso != null && AppUtils.ifNotNullEmpty(picassoRequestTag))
            picasso.cancelTag(picassoRequestTag);
        picasso = null;
        bitmaps = null;
    }

    public void createMergedBitmap(Context context, List<String> imageUrls, String picassoTag) {
        picasso = Picasso.with(context);
        int count = imageUrls.size();
        picassoRequestTag = picassoTag;

        boolean isEven = count % 2 == 0;
        // if url size are not even make MIN_IMAGE_SIZE even
        MIN_IMAGE_SIZE = DEFAULT_IMAGE_SIZE + (isEven ? count / 2 : (count / 2) + 1);
        // set MAX_WIDTH and MAX_HEIGHT to twice of MIN_IMAGE_SIZE
        MAX_WIDTH = MAX_HEIGHT = MIN_IMAGE_SIZE * 2;
        // in case of odd urls increase MAX_HEIGHT
        if (!isEven) MAX_HEIGHT = MAX_WIDTH + MIN_IMAGE_SIZE;

        // create default bitmap
        Bitmap bitmap = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(context.getResources(), R.drawable.ic_wallpaper),
                MIN_IMAGE_SIZE, MIN_IMAGE_SIZE, false);

        // change default height (wrap_content) to MAX_HEIGHT
        int height = Math.round(AppUtils.convertDpToPixel(MAX_HEIGHT, context));
        setMinimumHeight(height * 2);

        // start AsyncTask
        for (int index = 0; index < count; index++) {
            // put default bitmap as a place holder
            bitmaps.put(index, bitmap);
            new PicassoLoadImage(index, imageUrls.get(index)).execute();
            // if you want parallel execution use
            // new PicassoLoadImage(index, imageUrls.get(index)).(AsyncTask.THREAD_POOL_EXECUTOR);
        }
    }

    private class PicassoLoadImage extends AsyncTask<String, Void, Bitmap> {

        private int index = 0;
        private String url;

        PicassoLoadImage(int index, String url) {
            this.index = index;
            this.url = url;
        }

        @Override
        protected Bitmap doInBackground(String... params) {
            try {
                // synchronous picasso call
                return picasso.load(url).resize(MIN_IMAGE_SIZE, MIN_IMAGE_SIZE).tag(picassoRequestTag).get();
            } catch (IOException e) {
            }
            return null;
        }

        @Override
        protected void onPostExecute(Bitmap output) {
            super.onPostExecute(output);
            if (output != null)
                bitmaps.put(index, output);

            // create canvas
            Bitmap.Config conf = Bitmap.Config.RGB_565;
            Bitmap canvasBitmap = Bitmap.createBitmap(MAX_WIDTH, MAX_HEIGHT, conf);
            Canvas canvas = new Canvas(canvasBitmap);
            canvas.drawColor(Color.WHITE);

            // if height and width are equal we have even images
            boolean isEven = MAX_HEIGHT == MAX_WIDTH;
            int imageSize = bitmaps.size();
            int count = imageSize;

            // we have odd images
            if (!isEven) count = imageSize - 1;
            for (int i = 0; i < count; i++) {
                Bitmap bitmap = bitmaps.get(i);
                canvas.drawBitmap(bitmap, bitmap.getWidth() * (i % 2), bitmap.getHeight() * (i / 2), null);
            }
            // if images are not even set last image width to MAX_WIDTH
            if (!isEven) {
                Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmaps.get(count), MAX_WIDTH, MIN_IMAGE_SIZE, false);
                canvas.drawBitmap(scaledBitmap, scaledBitmap.getWidth() * (count % 2), scaledBitmap.getHeight() * (count / 2), null);
            }
            // set bitmap
            setImageBitmap(canvasBitmap);
        }
    }
}

xml

<com.example.MergeImageView
    android:id="@+id/iv_thumb"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Example

List<String> urls = new ArrayList<>();
String picassoTag = null;
// add your urls
((MergeImageView)findViewById(R.id.iv_thumb)).
        createMergedBitmap(MainActivity.this, urls,picassoTag);

Mean of a column in a data frame, given the column's name

Suppose you have a data frame(say df) with columns "x" and "y", you can find mean of column (x or y) using:

1.Using mean() function

z<-mean(df$x)

2.Using the column name(say x) as a variable using attach() function

 attach(df)
 mean(x)

When done you can call detach() to remove "x"

detach()

3.Using with() function, it lets you use columns of data frame as distinct variables.

 z<-with(df,mean(x))

SELECT INTO USING UNION QUERY

You can also try:

create table new_table as
select * from table1
union
select * from table2

What does the keyword "transient" mean in Java?

It means that trackDAO should not be serialized.

Centering Bootstrap input fields

Try to use this code:

.col-lg-3 {
  width: 100%;
}
.input-group {
   width: 200px; // for exemple
   margin: 0 auto;
}

if it didn't work use !important

How to insert text into the textarea at the current cursor position?

I like simple javascript, and I usually have jQuery around. Here's what I came up with, based off mparkuk's:

function typeInTextarea(el, newText) {
  var start = el.prop("selectionStart")
  var end = el.prop("selectionEnd")
  var text = el.val()
  var before = text.substring(0, start)
  var after  = text.substring(end, text.length)
  el.val(before + newText + after)
  el[0].selectionStart = el[0].selectionEnd = start + newText.length
  el.focus()
}

$("button").on("click", function() {
  typeInTextarea($("textarea"), "some text")
  return false
})

Here's a demo: http://codepen.io/erikpukinskis/pen/EjaaMY?editors=101

Prolog "or" operator, query

Just another viewpoint. Performing an "or" in Prolog can also be done with the "disjunct" operator or semi-colon:

registered(X, Y) :-
    X = ct101; X = ct102; X = ct103.

For a fuller explanation:

Predicate control in Prolog

numpy get index where value is true

You can use nonzero function. it returns the nonzero indices of the given input.

Easy Way

>>> (e > 15).nonzero()

(array([1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2]), array([6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))

to see the indices more cleaner, use transpose method:

>>> numpy.transpose((e>15).nonzero())

[[1 6]
 [1 7]
 [1 8]
 [1 9]
 [2 0]
 ...

Not Bad Way

>>> numpy.nonzero(e > 15)

(array([1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2]), array([6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))

or the clean way:

>>> numpy.transpose(numpy.nonzero(e > 15))

[[1 6]
 [1 7]
 [1 8]
 [1 9]
 [2 0]
 ...

How to read/write arbitrary bits in C/C++

"How do I for example read a 3 bit integer value starting at the second bit?"

int number = // whatever;
uint8_t val; // uint8_t is the smallest data type capable of holding 3 bits
val = (number & (1 << 2 | 1 << 3 | 1 << 4)) >> 2;

(I assumed that "second bit" is bit #2, i. e. the third bit really.)

Timeout jQuery effects

You can do something like this:

$('.notice')
    .fadeIn()
    .animate({opacity: '+=0'}, 2000)   // Does nothing for 2000ms
    .fadeOut('fast');

Sadly, you can't just do .animate({}, 2000) -- I think this is a bug, and will report it.