Programs & Examples On #Malformedurlexception

MalformedURLException is thrown to indicate that a malformed URL has occurred. Either no legal protocol could be found in a specification string or the string could not be parsed.

How to validate a url in Python? (Malformed or not)

A True or False version, based on @DMfll answer:

try:
    # python2
    from urlparse import urlparse
except:
    # python3
    from urllib.parse import urlparse

a = 'http://www.cwi.nl:80/%7Eguido/Python.html'
b = '/data/Python.html'
c = 532
d = u'dkakasdkjdjakdjadjfalskdjfalk'

def uri_validator(x):
    try:
        result = urlparse(x)
        return all([result.scheme, result.netloc, result.path])
    except:
        return False

print(uri_validator(a))
print(uri_validator(b))
print(uri_validator(c))
print(uri_validator(d))

Gives:

True
False
False
False

java.net.MalformedURLException: no protocol on URL based on a string modified with URLEncoder

You need to encode your parameter's values before concatenating them to URL.
Backslash \ is special character which have to be escaped as %5C

Escaping example:

String paramValue = "param\\with\\backslash";
String yourURLStr = "http://host.com?param=" + java.net.URLEncoder.encode(paramValue, "UTF-8");
java.net.URL url = new java.net.URL(yourURLStr);

The result is http://host.com?param=param%5Cwith%5Cbackslash which is properly formatted url string.

How do you redirect to a page using the POST verb?

If you want to pass data between two actions during a redirect without include any data in the query string, put the model in the TempData object.

ACTION

TempData["datacontainer"] = modelData;

VIEW

var modelData= TempData["datacontainer"] as ModelDataType; 

TempData is meant to be a very short-lived instance, and you should only use it during the current and the subsequent requests only! Since TempData works this way, you need to know for sure what the next request will be, and redirecting to another view is the only time you can guarantee this.

Therefore, the only scenario where using TempData will reliably work is when you are redirecting.

Java Comparator class to sort arrays

[...] How should Java Comparator class be declared to sort the arrays by their first elements in decreasing order [...]

Here's a complete example using Java 8:

import java.util.*;

public class Test {

    public static void main(String args[]) {

        int[][] twoDim = { {1, 2}, {3, 7}, {8, 9}, {4, 2}, {5, 3} };

        Arrays.sort(twoDim, Comparator.comparingInt(a -> a[0])
                                      .reversed());

        System.out.println(Arrays.deepToString(twoDim));
    }
}

Output:

[[8, 9], [5, 3], [4, 2], [3, 7], [1, 2]]

For Java 7 you can do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return Integer.compare(o2[0], o1[0]);
    }
});

If you unfortunate enough to work on Java 6 or older, you'd do:

Arrays.sort(twoDim, new Comparator<int[]>() {
    @Override
    public int compare(int[] o1, int[] o2) {
        return ((Integer) o2[0]).compareTo(o1[0]);
    }
});

MongoDB relationships: embed or reference?

Well, I'm a bit late but still would like to share my way of schema creation.

I have schemas for everything that can be described by a word, like you would do it in the classical OOP.

E.G.

  • Comment
  • Account
  • User
  • Blogpost
  • ...

Every schema can be saved as a Document or Subdocument, so I declare this for each schema.

Document:

  • Can be used as a reference. (E.g. the user made a comment -> comment has a "made by" reference to user)
  • Is a "Root" in you application. (E.g. the blogpost -> there is a page about the blogpost)

Subdocument:

  • Can only be used once / is never a reference. (E.g. Comment is saved in the blogpost)
  • Is never a "Root" in you application. (The comment just shows up in the blogpost page but the page is still about the blogpost)

Passing capturing lambda as function pointer

While the template approach is clever for various reasons, it is important to remember the lifecycle of the lambda and the captured variables. If any form of a lambda pointer is is going to be used and the lambda is not a downward continuation, then only a copying [=] lambda should used. I.e., even then, capturing a pointer to a variable on the stack is UNSAFE if the lifetime of those captured pointers (stack unwind) is shorter than the lifetime of the lambda.

A simpler solution for capturing a lambda as a pointer is:

auto pLamdba = new std::function<...fn-sig...>([=](...fn-sig...){...});

e.g., new std::function<void()>([=]() -> void {...}

Just remember to later delete pLamdba so ensure that you don't leak the lambda memory. Secret to realize here is that lambdas can capture lambdas (ask yourself how that works) and also that in order for std::function to work generically the lambda implementation needs to contain sufficient internal information to provide access to the size of the lambda (and captured) data (which is why the delete should work [running destructors of captured types]).

How to Import .bson file format on mongodb

It's very simple to import a .bson file:

mongorestore -d db_name -c collection_name /path/file.bson

Incase only for a single collection.Try this:

mongorestore --drop -d db_name -c collection_name /path/file.bson

For restoring the complete folder exported by mongodump:

mongorestore -d db_name /path/

How to set HTML Auto Indent format on Sublime Text 3?

Create a Keybinding

To auto indent on Sublime text 3 with a key bind try going to

Preferences > Key Bindings - users

And adding this code between the square brackets

{"keys": ["alt+shift+f"], "command": "reindent", "args": {"single_line": false}}

it sets shift + alt + f to be your full page auto indent.

Source here

Note: if this doesn't work correctly then you should convert your indentation to tabs. Also comments in your code can push your code to the wrong indentation level and may have to be moved manually.

What is the maximum length of a URL in different browsers?

The URI RFC (of which URLs are a subset) doesn't define a maximum length, however, it does recommend that the hostname part of the URI (if applicable) not exceed 255 characters in length:

URI producers should use names that conform to the DNS syntax, even when use of DNS is not immediately apparent, and should limit these names to no more than 255 characters in length.

As noted in other posts though, some browsers have a practical limitation on the length of a URL.

PHP Get Site URL Protocol - http vs https

I've tested the most voted answer and it didn't work for me, I ended up using:

$protocol = isset($_SERVER['HTTPS']) ? 'https://' : 'http://';

Difference Between Cohesion and Coupling

best explanation of Cohesion comes from Uncle Bob's Clean Code:

Classes should have a small number of instance variables. Each of the methods of a class should manipulate one or more of those variables. In general the more variables a method manipulates the more cohesive that method is to its class. A class in which each variable is used by each method is maximally cohesive.

In general it is neither advisable nor possible to create such maximally cohesive classes; on the other hand, we would like cohesion to be high. When cohesion is high, it means that the methods and variables of the class are co-dependent and hang together as a logical whole.

The strategy of keeping functions small and keeping parameter lists short can sometimes lead to a proliferation of instance variables that are used by a subset of methods. When this happens, it almost always means that there is at least one other class trying to get out of the larger class. You should try to separate the variables and methods into two or more classes such that the new classes are more cohesive.

What is the return value of os.system() in Python?

Based on the answer of @AlokThakur (thanks!):

def run_system_command(command):
    return_value = os.system(command)
    # Calculate the return value code
    return_value = int(bin(return_value).replace("0b", "").rjust(16, '0')[:8], 2)
    if return_value != 0:
        raise RuntimeError(f'The system command\n{command}\nexited with return code {return_value}')

How to parse string into date?

You can use:

SELECT CONVERT(datetime, '24.04.2012', 103) AS Date

Reference: CAST and CONVERT (Transact-SQL)

What is the difference between Hibernate and Spring Data JPA

There are 3 different things we are using here :

  1. JPA : Java persistence api which provide specification for persisting, reading, managing data from your java object to relations in database.
  2. Hibernate: There are various provider which implement jpa. Hibernate is one of them. So we have other provider as well. But if using jpa with spring it allows you to switch to different providers in future.
  3. Spring Data JPA : This is another layer on top of jpa which spring provide to make your life easy.

So lets understand how spring data jpa and spring + hibernate works-


Spring Data JPA:

Let's say you are using spring + hibernate for your application. Now you need to have dao interface and implementation where you will be writing crud operation using SessionFactory of hibernate. Let say you are writing dao class for Employee class, tomorrow in your application you might need to write similiar crud operation for any other entity. So there is lot of boilerplate code we can see here.

Now Spring data jpa allow us to define dao interfaces by extending its repositories(crudrepository, jparepository) so it provide you dao implementation at runtime. You don't need to write dao implementation anymore.Thats how spring data jpa makes your life easy.

Sorting an ArrayList of objects using a custom sorting order

This page tells you all you need to know about sorting collections, such as ArrayList.

Basically you need to

  • make your Contact class implement the Comparable interface by
    • creating a method public int compareTo(Contact anotherContact) within it.
  • Once you do this, you can just call Collections.sort(myContactList);,
    • where myContactList is ArrayList<Contact> (or any other collection of Contact).

There's another way as well, involving creating a Comparator class, and you can read about that from the linked page as well.

Example:

public class Contact implements Comparable<Contact> {

    ....

    //return -1 for less than, 0 for equals, and 1 for more than
    public compareTo(Contact anotherContact) {
        int result = 0;
        result = getName().compareTo(anotherContact.getName());
        if (result != 0)
        {
            return result;
        }
        result = getNunmber().compareTo(anotherContact.getNumber());
        if (result != 0)
        {
            return result;
        }
        ...
    }
}

How do I install PHP cURL on Linux Debian?

I wrote an article on topis how to [manually install curl on debian linu][1]x.

[1]: http://www.jasom.net/how-to-install-curl-command-manually-on-debian-linux. This is its shortcut:

  1. cd /usr/local/src
  2. wget http://curl.haxx.se/download/curl-7.36.0.tar.gz
  3. tar -xvzf curl-7.36.0.tar.gz
  4. rm *.gz
  5. cd curl-7.6.0
  6. ./configure
  7. make
  8. make install

And restart Apache. If you will have an error during point 6, try to run apt-get install build-essential.

MySql sum elements of a column

select
  sum(a) as atotal,
  sum(b) as btotal,
  sum(c) as ctotal
from
  yourtable t
where
  t.id in (1, 2, 3)

SQL update query using joins

You can specify additional tables used in determining how and what to update with the "FROM " clause in the UPDATE statement, like this:

update item_master
set mf_item_number = (some value)
from 
   group_master as gm
   join Manufacturar_Master as mm ON ........
where
 .... (your conditions here)

In the WHERE clause, you need to provide the conditions and join operations to bind these tables together.

Marc

Given a filesystem path, is there a shorter way to extract the filename without its extension?

You can use Path API as follow:

 var filenNme = Path.GetFileNameWithoutExtension([File Path]);

More info: Path.GetFileNameWithoutExtension

Inline onclick JavaScript variable

Yes, JavaScript variables will exist in the scope they are created.

var bannerID = 55;

<input id="EditBanner" type="button" 
  value="Edit Image" onclick="EditBanner(bannerID);"/>


function EditBanner(id) {
   //Do something with id
}

If you use event handlers and jQuery it is simple also

$("#EditBanner").click(function() {
   EditBanner(bannerID);
});

Is there a way I can retrieve sa password in sql server 2005

Wait!

There is a way to retrieve the password by using Brute-Force attack, have a look at the following tool from codeproject Retrieve SQL Server Password


How to use the tool to retrieve the password

To Retrieve the password of SQL Server user,run the following query in SQL Query Analyzer

"Select Password from SysxLogins Where Name = 'XXXX'" Where XXXX is the user

name for which you want to retrieve password.Copy the password field (Hashed Code) and

paste here (in Hashed code Field) and click on start button to retrieve

I checked the tool on SQLServer 2000 and it's working fine.

How to select rows for a specific date, ignoring time in SQL Server

I know it's been a while on this question, but I was just looking for the same answer and found this seems to be the simplest solution:

select * from sales where datediff(dd, salesDate, '20101111') = 0

I actually use it more to find things within the last day or two, so my version looks like this:

select * from sales where datediff(dd, salesDate, getdate()) = 0

And by changing the 0 for today to a 1 I get yesterday's transactions, 2 is the day before that, and so on. And if you want everything for the last week, just change the equals to a less-than-or-equal-to:

select * from sales where datediff(dd, salesDate, getdate()) <= 7

How to get the index of an element in an IEnumerable?

A bit late in the game, i know... but this is what i recently did. It is slightly different than yours, but allows the programmer to dictate what the equality operation needs to be (predicate). Which i find very useful when dealing with different types, since i then have a generic way of doing it regardless of object type and <T> built in equality operator.

It also has a very very small memory footprint, and is very, very fast/efficient... if you care about that.

At worse, you'll just add this to your list of extensions.

Anyway... here it is.

 public static int IndexOf<T>(this IEnumerable<T> source, Func<T, bool> predicate)
 {
     int retval = -1;
     var enumerator = source.GetEnumerator();

     while (enumerator.MoveNext())
     {
         retval += 1;
         if (predicate(enumerator.Current))
         {
             IDisposable disposable = enumerator as System.IDisposable;
             if (disposable != null) disposable.Dispose();
             return retval;
         }
     }
     IDisposable disposable = enumerator as System.IDisposable;
     if (disposable != null) disposable.Dispose();
     return -1;
 }

Hopefully this helps someone.

Include of non-modular header inside framework module

You can set Allow Non-modular includes in Framework Modules in Build Settings for the affected target to YES. This is the build setting you need to edit:

Build Settings item you need to edit

NOTE: You should use this feature to uncover the underlying error, which I have found to be frequently caused by duplication of angle-bracketed global includes in files with some dependent relationship, i.e.:

#import <Foo/Bar.h> // referred to in two or more dependent files

If setting Allow Non-modular includes in Frame Modules to YES results in a set of "X is an ambiguous reference" errors or something of the sort, you should be able to track down the offending duplicate(s) and eliminate them. After you've cleaned up your code, set Allow Non-modular includes in Frame Modules back to NO.

How to get cumulative sum

Select *, (Select SUM(SOMENUMT) From @t S Where S.id <= M.id) From @t M

Intermediate language used in scalac?

The nearest equivalents would be icode and bcode as used by scalac, view Miguel Garcia's site on the Scalac optimiser for more information, here: http://magarciaepfl.github.io/scala/

You might also consider Java bytecode itself to be your intermediate representation, given that bytecode is the ultimate output of scalac.

Or perhaps the true intermediate is something that the JIT produces before it finally outputs native instructions?

Ultimately though... There's no single place that you can point at an claim "there's the intermediate!". Scalac works in phases that successively change the abstract syntax tree, every single phase produces a new intermediate. The whole thing is like an onion, and it's very hard to try and pick out one layer as somehow being more significant than any other.

How do you kill a Thread in Java?

Thread.stop is deprecated so how do we stop a thread in java ?

Always use interrupt method and future to request cancellation

  1. When the task responds to interrupt signal, for example, blocking queue take method.
Callable < String > callable = new Callable < String > () {
    @Override
    public String call() throws Exception {
        String result = "";
        try {
            //assume below take method is blocked as no work is produced.
            result = queue.take();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
        return result;
    }
};
Future future = executor.submit(callable);
try {
    String result = future.get(5, TimeUnit.SECONDS);
} catch (TimeoutException e) {
    logger.error("Thread timedout!");
    return "";
} finally {
    //this will call interrupt on queue which will abort the operation.
    //if it completes before time out, it has no side effects
    future.cancel(true);
}

  1. When the task does not respond to interrupt signal.Suppose the task performs socket I/O which does not respond to interrupt signal and thus using above approach will not abort the task, future would time out but the cancel in finally block will have no effect, thread will keep on listening to socket. We can close the socket or call close method on connection if implemented by pool.
public interface CustomCallable < T > extends Callable < T > {
    void cancel();
    RunnableFuture < T > newTask();
}

public class CustomExecutorPool extends ThreadPoolExecutor {
    protected < T > RunnableFuture < T > newTaskFor(Callable < T > callable) {
        if (callable instanceof CancellableTask)
            return ((CancellableTask < T > ) callable).newTask();
        else
            return super.newTaskFor(callable);
    }
}

public abstract class UnblockingIOTask < T > implements CustomCallable < T > {
    public synchronized void cancel() {
        try {
            obj.close();
        } catch (IOException e) {
            logger.error("io exception", e);
        }
    }

    public RunnableFuture < T > newTask() {
        return new FutureTask < T > (this) {
            public boolean cancel(boolean mayInterruptIfRunning) {
                try {
                    this.cancel();
                } finally {
                    return super.cancel(mayInterruptIfRunning);
                }
            }

        };
    }
}

wait until all threads finish their work in java

You do

for (Thread t : new Thread[] { th1, th2, th3, th4, th5 })
    t.join()

After this for loop, you can be sure all threads have finished their jobs.

how to clear JTable

If we use tMOdel.setRowCount(0); we can get Empty table.

DefaultTableModel tMOdel = (DefaultTableModel) jtableName.getModel();
tMOdel.setRowCount(0);

Check if string ends with certain pattern

    String input1 = "This.is.a.great.place.too.work.";
    String input2 = "This/is/a/great/place/too/work/";
    String input3 = "This,is,a,great,place,too,work,";
    String input4 = "This.is.a.great.place.too.work.hahahah";
    String input5 = "This/is/a/great/place/too/work/hahaha";
    String input6 = "This,is,a,great,place,too,work,hahahha";
    
    String regEx = ".*work[.,/]";
    
    System.out.println(input1.matches(regEx)); // true
    System.out.println(input2.matches(regEx)); // true
    System.out.println(input3.matches(regEx)); // true
    System.out.println(input4.matches(regEx)); // false
    System.out.println(input5.matches(regEx)); // false
    System.out.println(input6.matches(regEx)); // false

Python: print a generator expression?

>>> list(x for x in string.letters if x in (y for y in "BigMan on campus"))
['a', 'c', 'g', 'i', 'm', 'n', 'o', 'p', 's', 'u', 'B', 'M']

C++/CLI Converting from System::String^ to std::string

C# uses the UTF16 format for its strings.
So, besides just converting the types, you should also be conscious about the string's actual format.

When compiling for Multi-byte Character set Visual Studio and the Win API assumes UTF8 (Actually windows encoding which is Windows-28591 ).
When compiling for Unicode Character set Visual studio and the Win API assume UTF16.

So, you must convert the string from UTF16 to UTF8 format as well, and not just convert to std::string.
This will become necessary when working with multi-character formats like some non-latin languages.

The idea is to decide that std::wstring always represents UTF16.
And std::string always represents UTF8.

This isn't enforced by the compiler, it's more of a good policy to have.

#include "stdafx.h"
#include <string>
#include <codecvt>
#include <msclr\marshal_cppstd.h>

using namespace System;

int main(array<System::String ^> ^args)
{
    System::String^ managedString = "test";

    msclr::interop::marshal_context context;

    //Actual format is UTF16, so represent as wstring
    std::wstring utf16NativeString = context.marshal_as<std::wstring>(managedString); 

    //C++11 format converter
    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> convert;

    //convert to UTF8 and std::string
    std::string utf8NativeString = convert.to_bytes(utf16NativeString);

    return 0;
}

Or have it in a more compact syntax:

int main(array<System::String ^> ^args)
{
    System::String^ managedString = "test";

    msclr::interop::marshal_context context;
    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> convert;

    std::string utf8NativeString = convert.to_bytes(context.marshal_as<std::wstring>(managedString));

    return 0;
}

ElasticSearch, Sphinx, Lucene, Solr, Xapian. Which fits for which usage?

I have used Sphinx, Solr and Elasticsearch. Solr/Elasticsearch are built on top of Lucene. It adds many common functionality: web server api, faceting, caching, etc.

If you want to just have a simple full text search setup, Sphinx is a better choice.

If you want to customize your search at all, Elasticsearch and Solr are the better choices. They are very extensible: you can write your own plugins to adjust result scoring.

Some example usages:

  • Sphinx: craigslist.org
  • Solr: Cnet, Netflix, digg.com
  • Elasticsearch: Foursquare, Github

PHP: Split a string in to an array foreach char

You can access characters in strings in the same way as you would access an array index, e.g.

$length = strlen($string);
$thisWordCodeVerdeeld = array();
for ($i=0; $i<$length; $i++) {
    $thisWordCodeVerdeeld[$i] = $string[$i];
}

You could also do:

$thisWordCodeVerdeeld = str_split($string);

However you might find it is easier to validate the string as a whole string, e.g. using regular expressions.

Determine Whether Two Date Ranges Overlap

This was my solution, it returns true when the values don't overlap:

X START 1 Y END 1

A START 2 B END 2

TEST1: (X <= A || X >= B)
        &&
TEST2: (Y >= B || Y <= A) 
        && 
TEST3: (X >= B || Y <= A)


X-------------Y
    A-----B

TEST1:  TRUE
TEST2:  TRUE
TEST3:  FALSE
RESULT: FALSE

---------------------------------------

X---Y
      A---B

TEST1:  TRUE
TEST2:  TRUE
TEST3:  TRUE
RESULT: TRUE

---------------------------------------

      X---Y
A---B

TEST1:  TRUE
TEST2:  TRUE
TEST3:  TRUE
RESULT: TRUE

---------------------------------------

     X----Y
A---------------B

TEST1:  FALSE
TEST2:  FALSE
TEST3:  FALSE
RESULT: FALSE

Comparing two java.util.Dates to see if they are in the same day

Java 8

If you are using Java 8 in your project and comparing java.sql.Timestamp, you could use the LocalDate class:

sameDate = date1.toLocalDateTime().toLocalDate().equals(date2.toLocalDateTime().toLocalDate());

If you are using java.util.Date, have a look at Istvan answer which is less ambiguous.

Strange out of memory issue while loading an image to a Bitmap object

None of the answers above worked for me, but I did come up with a horribly ugly workaround that solved the problem. I added a very small, 1x1 pixel image to my project as a resource, and loaded it into my ImageView before calling into garbage collection. I think it might be that the ImageView was not releasing the Bitmap, so GC never picked it up. It's ugly, but it seems to be working for now.

if (bitmap != null)
{
  bitmap.recycle();
  bitmap = null;
}
if (imageView != null)
{
  imageView.setImageResource(R.drawable.tiny); // This is my 1x1 png.
}
System.gc();

imageView.setImageBitmap(...); // Do whatever you need to do to load the image you want.

Post form data using HttpWebRequest

Use this code:

internal void SomeFunction() {
    Dictionary<string, string> formField = new Dictionary<string, string>();
    
    formField.Add("Name", "Henry");
    formField.Add("Age", "21");
    
    string body = GetBodyStringFromDictionary(formField);
    // output : Name=Henry&Age=21
}

internal string GetBodyStringFromDictionary(Dictionary<string, string> formField)
{
    string body = string.Empty;
    foreach (var pair in formField)
    {
        body += $"{pair.Key}={pair.Value}&";   
    }

    // delete last "&"
    body = body.Substring(0, body.Length - 1);

    return body;
}

How to Automatically Start a Download in PHP?

my code works for txt,doc,docx,pdf,ppt,pptx,jpg,png,zip extensions and I think its better to use the actual MIME types explicitly.

$file_name = "a.txt";

// extracting the extension:
$ext = substr($file_name, strpos($file_name,'.')+1);

header('Content-disposition: attachment; filename='.$file_name);

if(strtolower($ext) == "txt")
{
    header('Content-type: text/plain'); // works for txt only
}
else
{
    header('Content-type: application/'.$ext); // works for all extensions except txt
}
readfile($decrypted_file_path);

Range with step of type float

One explanation might be floating point rounding issues. For example, if you could call

range(0, 0.4, 0.1)

you might expect an output of

[0, 0.1, 0.2, 0.3]

but you in fact get something like

[0, 0.1, 0.2000000001, 0.3000000001]

due to rounding issues. And since range is often used to generate indices of some sort, it's integers only.

Still, if you want a range generator for floats, you can just roll your own.

def xfrange(start, stop, step):
    i = 0
    while start + i * step < stop:
        yield start + i * step
        i += 1

jQuery events .load(), .ready(), .unload()

NOTE: .load() & .unload() have been deprecated


$(window).load();

Will execute after the page along with all its contents are done loading. This means that all images, CSS (and content defined by CSS like custom fonts and images), scripts, etc. are all loaded. This happens event fires when your browser's "Stop" -icon becomes gray, so to speak. This is very useful to detect when the document along with all its contents are loaded.

$(document).ready();

This on the other hand will fire as soon as the web browser is capable of running your JavaScript, which happens after the parser is done with the DOM. This is useful if you want to execute JavaScript as soon as possible.

$(window).unload();

This event will be fired when you are navigating off the page. That could be Refresh/F5, pressing the previous page button, navigating to another website or closing the entire tab/window.

To sum up, ready() will be fired before load(), and unload() will be the last to be fired.

Pandas How to filter a Series

As DACW pointed out, there are method-chaining improvements in pandas 0.18.1 that do what you are looking for very nicely.

Rather than using .where, you can pass your function to either the .loc indexer or the Series indexer [] and avoid the call to .dropna:

test = pd.Series({
383:    3.000000,
663:    1.000000,
726:    1.000000,
737:    9.000000,
833:    8.166667
})

test.loc[lambda x : x!=1]

test[lambda x: x!=1]

Similar behavior is supported on the DataFrame and NDFrame classes.

gem install: Failed to build gem native extension (can't find header files)

My initial solution was to resolve the above errors by installing ruby-devel, patch and rubygems.

My issue was a bit different as bcrypt 3.1.11 still had issues compiling and installing on Fedora 23. I needed additional packages. So after ensuring I had the above installed, I was still having issues:

gcc: error: conftest.c: No such file or directory

gcc: error: /usr/lib/rpm/redhat/redhat-hardened-cc1: No such file or directory

From here I had to do the following:

  • I ensured that I wasn't lacking any C compiler tools sudo dnf group install "C Development Tools and Libraries"

  • Then I ran sudo dnf install redhat-rpm-config to resolve the gcc issue listed above.

You can find a write up here on Fedore Project. You may also find answers to other needs as well.

AngularJS How to dynamically add HTML and bind to controller

I needed to execute an directive AFTER loading several templates so I created this directive:

_x000D_
_x000D_
utilModule.directive('utPreload',_x000D_
    ['$templateRequest', '$templateCache', '$q', '$compile', '$rootScope',_x000D_
    function($templateRequest, $templateCache, $q, $compile, $rootScope) {_x000D_
    'use strict';_x000D_
    var link = function(scope, element) {_x000D_
        scope.$watch('done', function(done) {_x000D_
            if(done === true) {_x000D_
                var html = "";_x000D_
                if(scope.slvAppend === true) {_x000D_
                    scope.urls.forEach(function(url) {_x000D_
                        html += $templateCache.get(url);_x000D_
                    });_x000D_
                }_x000D_
                html += scope.slvHtml;_x000D_
                element.append($compile(html)($rootScope));_x000D_
            }_x000D_
        });_x000D_
    };_x000D_
_x000D_
    var controller = function($scope) {_x000D_
        $scope.done = false;_x000D_
        $scope.html = "";_x000D_
        $scope.urls = $scope.slvTemplate.split(',');_x000D_
        var promises = [];_x000D_
        $scope.urls.forEach(function(url) {_x000D_
            promises.add($templateRequest(url));_x000D_
        });_x000D_
        $q.all(promises).then(_x000D_
            function() { // SUCCESS_x000D_
                $scope.done = true;_x000D_
            }, function() { // FAIL_x000D_
                throw new Error('preload failed.');_x000D_
            }_x000D_
        );_x000D_
    };_x000D_
_x000D_
    return {_x000D_
        restrict: 'A',_x000D_
        scope: {_x000D_
            utTemplate: '=', // the templates to load (comma separated)_x000D_
            utAppend: '=', // boolean: append templates to DOM after load?_x000D_
            utHtml: '=' // the html to append and compile after templates have been loaded_x000D_
        },_x000D_
        link: link,_x000D_
        controller: controller_x000D_
    };_x000D_
}]);
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js"></script>_x000D_
_x000D_
<div class="container-fluid"_x000D_
     ut-preload_x000D_
     ut-append="true"_x000D_
     ut-template="'html/one.html,html/two.html'"_x000D_
     ut-html="'<my-directive></my-directive>'">_x000D_
 _x000D_
</div>
_x000D_
_x000D_
_x000D_

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

Using the below line

SELECT LEFT(subject , 10) FROM tbl 

MySQL Doc.

Repeat a string in JavaScript a number of times

I'm going to expand on @bonbon's answer. His method is an easy way to "append N chars to an existing string", just in case anyone needs to do that. For example since "a google" is a 1 followed by 100 zeros.

_x000D_
_x000D_
for(var google = '1'; google.length < 1 + 100; google += '0'){}_x000D_
document.getElementById('el').innerText = google;
_x000D_
<div>This is "a google":</div>_x000D_
<div id="el"></div>
_x000D_
_x000D_
_x000D_

NOTE: You do have to add the length of the original string to the conditional.

Private class declaration

You can't have private class but you can have second class:

public class App14692708 {
    public static void main(String[] args) {
        PC pc = new PC();
        System.out.println(pc);
    }
}

class PC {
    @Override
    public String toString() {
        return "I am PC instance " + super.toString();
    }
}

Also remember that static inner class is indistinguishable of separate class except it's name is OuterClass.InnerClass. So if you don't want to use "closures", use static inner class.

Remove new lines from string and replace with one empty space

PCRE regex replacements can be done using preg_replace: http://php.net/manual/en/function.preg-replace.php

$new_string = preg_replace("/\r\n|\r|\n/", ' ', $old_string);

Would replace new line or return characters with a space. If you don't want anything to replace them, change the 2nd argument to ''.

Android Location Providers - GPS or Network Provider?

There are some great answers mentioned here. Another approach you could take would be to use some free SDKs available online like Atooma, tranql and Neura, that can be integrated with your Android application (it takes less than 20 min to integrate). Along with giving you the accurate location of your user, it can also give you good insights about your user’s activities. Also, some of them consume less than 1% of your battery

How to create a drop-down list?

enter image description here

Here is the code for it.

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<Spinner
    android:id="@+id/static_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="20dp"
    android:layout_marginTop="20dp" />

<Spinner
    android:id="@+id/dynamic_spinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" />

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">Ahotbrew.com - Dropdown</string> 
<string-array name="brew_array">
    <item>Cappuccino</item>
    <item>Espresso</item>
    <item>Mocha</item>
    <item>Caffè Americano</item>
    <item>Cafe Zorro</item>
</string-array> 

MainActivity

Spinner staticSpinner = (Spinner) findViewById(R.id.static_spinner);

    // Create an ArrayAdapter using the string array and a default spinner
    ArrayAdapter<CharSequence> staticAdapter = ArrayAdapter
            .createFromResource(this, R.array.brew_array,
                    android.R.layout.simple_spinner_item);

    // Specify the layout to use when the list of choices appears
    staticAdapter
            .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    // Apply the adapter to the spinner
    staticSpinner.setAdapter(staticAdapter);

    Spinner dynamicSpinner = (Spinner) findViewById(R.id.dynamic_spinner);

    String[] items = new String[] { "Chai Latte", "Green Tea", "Black Tea" };

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_spinner_item, items);

    dynamicSpinner.setAdapter(adapter);

    dynamicSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
            Log.v("item", (String) parent.getItemAtPosition(position));
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            // TODO Auto-generated method stub
        }
    });

This example is from http://www.ahotbrew.com/android-dropdown-spinner-example/

Excel: Creating a dropdown using a list in another sheet?

Yes it is. Use Data Validation from the Data panel. Select Allow: List and pick those cells on the other sheet as your source.

What are .NET Assemblies?

Visual Studio solutions consists of one or more projects. For Example : Console projects can produce an assembly. An assembly is logically chunk of code that can be shipped to customers, and physically an .EXE (executable program) or .DLL (are reusable by other programs).

What's the difference between SoftReference and WeakReference in Java?

In Java; order from strongest to weakest, there are: Strong, Soft, Weak and Phantom

A Strong reference is a normal reference that protects the referred object from collection by GC. i.e. Never garbage collects.

A Soft reference is eligible for collection by garbage collector, but probably won't be collected until its memory is needed. i.e. garbage collects before OutOfMemoryError.

A Weak reference is a reference that does not protect a referenced object from collection by GC. i.e. garbage collects when no Strong or Soft refs.

A Phantom reference is a reference to an object is phantomly referenced after it has been finalized, but before its allocated memory has been reclaimed.

Source

Analogy: Assume a JVM is a kingdom, Object is a king of the kingdom, and GC is an attacker of the kingdom who tries to kill the king(object).

  • When King is Strong, GC can not kill him.
  • When King is Soft, GC attacks him but King rule the kingdom with protection until resource are available.
  • When King is Weak, GC attacks him but rule the kingdom without protection.
  • When king is Phantom, GC already killed him but king is available via his soul.

Open new popup window without address bars in firefox & IE

Check the mozilla documentation on window.open. The window features ("directory=...,...,height=350") etc. arguments should be a string:

window.open('/pageaddress.html','winname',"directories=0,titlebar=0,toolbar=0,location=0,status=0,menubar=0,scrollbars=no,resizable=no,width=400,height=350");

Try if that works in your browsers. Note that some of the features might be overridden by user preferences, such as "location" (see doc.)

SQL Server AS statement aliased column within WHERE statement

I am not sure why you cannot use "lat" but, if you must you can rename the columns in a derived table.

select latitude from (SELECT lat AS latitude FROM poi_table) p where latitude < 500

Load HTML File Contents to Div [without the use of iframes]

    document.getElementById("id").innerHTML='<object type="text/html" data="x.html"></object>';

Installation Issue with matplotlib Python

Problem Cause

In mac os image rendering back end of matplotlib (what-is-a-backend to render using the API of Cocoa by default). There are Qt4Agg and GTKAgg and as a back-end is not the default. Set the back end of macosx that is differ compare with other windows or linux os.

Solution

  • I assume you have installed the pip matplotlib, there is a directory in your root called ~/.matplotlib.
  • Create a file ~/.matplotlib/matplotlibrc there and add the following code: backend: TkAgg

From this link you can try different diagrams.

How do I exit a while loop in Java?

Use break:

while (true) {
    ....
    if (obj == null) {
        break;
    }
    ....
}

However, if your code looks exactly like you have specified you can use a normal while loop and change the condition to obj != null:

while (obj != null) {
    ....
}

How to export data from Spark SQL to CSV

enter code here IN DATAFRAME:

val p=spark.read.format("csv").options(Map("header"->"true","delimiter"->"^")).load("filename.csv")

Passing an array as an argument to a function in C

When passing an array as a parameter, this

void arraytest(int a[])

means exactly the same as

void arraytest(int *a)

so you are modifying the values in main.

For historical reasons, arrays are not first class citizens and cannot be passed by value.

Reading from a text file and storing in a String

How can we read data from a text file and store in a String Variable?

Err, read data from the file and store it in a String variable. It's just code. Not a real question so far.

Is it possible to pass the filename in a method and it would return the String which is the text from the file.

Yes it's possible. It's also a very bad idea. You should deal with the file a part at a time, for example a line at a time. Reading the entire file into memory before you process any of it adds latency; wastes memory; and assumes that the entire file will fit into memory. One day it won't. You don't want to do it this way.

Not an enclosing class error Android Studio

replace code in onClick() method with this:

Intent myIntent = new Intent(this, Katra_home.class);
startActivity(myIntent);

Removing elements with Array.map in JavaScript

You should use the filter method rather than map unless you want to mutate the items in the array, in addition to filtering.

eg.

var filteredItems = items.filter(function(item)
{
    return ...some condition...;
});

[Edit: Of course you could always do sourceArray.filter(...).map(...) to both filter and mutate]

How do I line up 3 divs on the same row?

Another possible solution:

<div>
  <h2 align="center">
  San Andreas: Multiplayer
</h2>
    <div align="center">
<font size="+1"><em class="heading_description">15 pence per
slot</em></font> <img src=
"http://fhers.com/images/game_servers/sa-mp.jpg" class=
"alignleft noTopMargin" style="width: 188px;" /> <a href="gfh"
class="order-small"><span>order</span></a>
    </div>
 </div>

Also helpful as well.

bash shell nested for loop

One one line (semi-colons necessary):

for i in 0 1 2 3 4 5 6 7 8 9; do for j in 0 1 2 3 4 5 6 7 8 9; do echo "$i$j"; done; done

Formatted for legibility (no semi-colons needed):

for i in 0 1 2 3 4 5 6 7 8 9
do
    for j in 0 1 2 3 4 5 6 7 8 9
    do 
        echo "$i$j"
    done
done

There are different views on how the shell code should be laid out over multiple lines; that's about what I normally use, unless I put the next operation on the same line as the do (saving two lines here).

Convert stdClass object to array in PHP

While converting a STD class object to array.Cast the object to array by using array function of php.

Try out with following code snippet.

/*** cast the object ***/    
foreach($stdArray as $key => $value)
{
    $stdArray[$key] = (array) $value;
}   
/*** show the results ***/  
print_r( $stdArray );

Format date as dd/MM/yyyy using pipes

You can achieve this using by a simple custom pipe.

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

@Pipe({
    name: 'dateFormatPipe',
})
export class dateFormatPipe implements PipeTransform {
    transform(value: string) {
       var datePipe = new DatePipe("en-US");
        value = datePipe.transform(value, 'dd/MM/yyyy');
        return value;
    }
}


{{currentDate | dateFormatPipe }}

Advantage of using a custom pipe is that, if you want to update the date format in future, you can go and update your custom pipe and it will reflect every where.

Custom Pipe examples

How do I strip all spaces out of a string in PHP?

If you know the white space is only due to spaces, you can use:

$string = str_replace(' ','',$string); 

But if it could be due to space, tab...you can use:

$string = preg_replace('/\s+/','',$string);

Detecting a redirect in ajax request?

While the other folks who answered this question are (sadly) correct that this information is hidden from us by the browser, I thought I'd post a workaround I came up with:

I configured my server app to set a custom response header (X-Response-Url) containing the url that was requested. Whenever my ajax code receives a response, it checks if xhr.getResponseHeader("x-response-url") is defined, in which case it compares it to the url that it originally requested via $.ajax(). If the strings differ, I know there was a redirect, and additionally, what url we actually arrived at.

This does have the drawback of requiring some server-side help, and also may break down if the url gets munged (due to quoting/encoding issues etc) during the round trip... but for 99% of cases, this seems to get the job done.


On the server side, my specific case was a python application using the Pyramid web framework, and I used the following snippet:

import pyramid.events

@pyramid.events.subscriber(pyramid.events.NewResponse)
def set_response_header(event):
    request = event.request
    if request.is_xhr:
        event.response.headers['X-Response-URL'] = request.url

How to dispatch a Redux action with a timeout?

Using Redux-saga

As Dan Abramov said, if you want more advanced control over your async code, you might take a look at redux-saga.

This answer is a simple example, if you want better explanations on why redux-saga can be useful for your application, check this other answer.

The general idea is that Redux-saga offers an ES6 generators interpreter that permits you to easily write async code that looks like synchronous code (this is why you'll often find infinite while loops in Redux-saga). Somehow, Redux-saga is building its own language directly inside Javascript. Redux-saga can feel a bit difficult to learn at first, because you need basic understanding of generators, but also understand the language offered by Redux-saga.

I'll try here to describe here the notification system I built on top of redux-saga. This example currently runs in production.

Advanced notification system specification

  • You can request a notification to be displayed
  • You can request a notification to hide
  • A notification should not be displayed more than 4 seconds
  • Multiple notifications can be displayed at the same time
  • No more than 3 notifications can be displayed at the same time
  • If a notification is requested while there are already 3 displayed notifications, then queue/postpone it.

Result

Screenshot of my production app Stample.co

toasts

Code

Here I named the notification a toast but this is a naming detail.

function* toastSaga() {

    // Some config constants
    const MaxToasts = 3;
    const ToastDisplayTime = 4000;


    // Local generator state: you can put this state in Redux store
    // if it's really important to you, in my case it's not really
    let pendingToasts = []; // A queue of toasts waiting to be displayed
    let activeToasts = []; // Toasts currently displayed


    // Trigger the display of a toast for 4 seconds
    function* displayToast(toast) {
        if ( activeToasts.length >= MaxToasts ) {
            throw new Error("can't display more than " + MaxToasts + " at the same time");
        }
        activeToasts = [...activeToasts,toast]; // Add to active toasts
        yield put(events.toastDisplayed(toast)); // Display the toast (put means dispatch)
        yield call(delay,ToastDisplayTime); // Wait 4 seconds
        yield put(events.toastHidden(toast)); // Hide the toast
        activeToasts = _.without(activeToasts,toast); // Remove from active toasts
    }

    // Everytime we receive a toast display request, we put that request in the queue
    function* toastRequestsWatcher() {
        while ( true ) {
            // Take means the saga will block until TOAST_DISPLAY_REQUESTED action is dispatched
            const event = yield take(Names.TOAST_DISPLAY_REQUESTED);
            const newToast = event.data.toastData;
            pendingToasts = [...pendingToasts,newToast];
        }
    }


    // We try to read the queued toasts periodically and display a toast if it's a good time to do so...
    function* toastScheduler() {
        while ( true ) {
            const canDisplayToast = activeToasts.length < MaxToasts && pendingToasts.length > 0;
            if ( canDisplayToast ) {
                // We display the first pending toast of the queue
                const [firstToast,...remainingToasts] = pendingToasts;
                pendingToasts = remainingToasts;
                // Fork means we are creating a subprocess that will handle the display of a single toast
                yield fork(displayToast,firstToast);
                // Add little delay so that 2 concurrent toast requests aren't display at the same time
                yield call(delay,300);
            }
            else {
                yield call(delay,50);
            }
        }
    }

    // This toast saga is a composition of 2 smaller "sub-sagas" (we could also have used fork/spawn effects here, the difference is quite subtile: it depends if you want toastSaga to block)
    yield [
        call(toastRequestsWatcher),
        call(toastScheduler)
    ]
}

And the reducer:

const reducer = (state = [],event) => {
    switch (event.name) {
        case Names.TOAST_DISPLAYED:
            return [...state,event.data.toastData];
        case Names.TOAST_HIDDEN:
            return _.without(state,event.data.toastData);
        default:
            return state;
    }
};

Usage

You can simply dispatch TOAST_DISPLAY_REQUESTED events. If you dispatch 4 requests, only 3 notifications will be displayed, and the 4th one will appear a bit later once the 1st notification disappears.

Note that I don't specifically recommend dispatching TOAST_DISPLAY_REQUESTED from JSX. You'd rather add another saga that listens to your already-existing app events, and then dispatch the TOAST_DISPLAY_REQUESTED: your component that triggers the notification, does not have to be tightly coupled to the notification system.

Conclusion

My code is not perfect but runs in production with 0 bugs for months. Redux-saga and generators are a bit hard initially but once you understand them this kind of system is pretty easy to build.

It's even quite easy to implement more complex rules, like:

  • when too many notifications are "queued", give less display-time for each notification so that the queue size can decrease faster.
  • detect window size changes, and change the maximum number of displayed notifications accordingly (for example, desktop=3, phone portrait = 2, phone landscape = 1)

Honnestly, good luck implementing this kind of stuff properly with thunks.

Note you can do exactly the same kind of thing with redux-observable which is very similar to redux-saga. It's almost the same and is a matter of taste between generators and RxJS.

Android emulator not able to access the internet

On Latest Mac with Jio IP6 Configuration issue ,it block internet on android simulator ,so from Android Virtual Device Manager simulator list Actions column dropdown select the option "Cold Boot Now" fixed the issue.I faced this problem after i kept same its working for me.

Does Java have a path joining method?

Try:

String path1 = "path1";
String path2 = "path2";

String joinedPath = new File(path1, path2).toString();

How to get unique device hardware id in Android?

Please read this official blog entry on Google developer blog: http://android-developers.blogspot.be/2011/03/identifying-app-installations.html

Conclusion For the vast majority of applications, the requirement is to identify a particular installation, not a physical device. Fortunately, doing so is straightforward.

There are many good reasons for avoiding the attempt to identify a particular device. For those who want to try, the best approach is probably the use of ANDROID_ID on anything reasonably modern, with some fallback heuristics for legacy devices

.

Executing a command stored in a variable from PowerShell

Here is yet another way without Invoke-Expression but with two variables (command:string and parameters:array). It works fine for me. Assume 7z.exe is in the system path.

$cmd = '7z.exe'
$prm = 'a', '-tzip', 'c:\temp\with space\test1.zip', 'C:\TEMP\with space\changelog'

& $cmd $prm

If the command is known (7z.exe) and only parameters are variable then this will do

$prm = 'a', '-tzip', 'c:\temp\with space\test1.zip', 'C:\TEMP\with space\changelog'

& 7z.exe $prm

BTW, Invoke-Expression with one parameter works for me, too, e.g. this works

$cmd = '& 7z.exe a -tzip "c:\temp\with space\test2.zip" "C:\TEMP\with space\changelog"'

Invoke-Expression $cmd

P.S. I usually prefer the way with a parameter array because it is easier to compose programmatically than to build an expression for Invoke-Expression.

Pandas: change data type of Series to String

Personally none of the above worked for me. What did:

new_str = [str(x) for x in old_obj][0]

Validating IPv4 addresses with regexp

I was in search of something similar for IPv4 addresses - a regex that also stopped commonly used private ip addresses from being validated (192.168.x.y, 10.x.y.z, 172.16.x.y) so used negative look aheads to accomplish this:

(?!(10\.|172\.(1[6-9]|2\d|3[01])\.|192\.168\.).*)
(?!255\.255\.255\.255)(25[0-5]|2[0-4]\d|[1]\d\d|[1-9]\d|[1-9])
(\.(25[0-5]|2[0-4]\d|[1]\d\d|[1-9]\d|\d)){3}

(These should be on one line of course, formatted for readability purposes on 3 separate lines) Regular expression visualization

Debuggex Demo

It may not be optimised for speed, but works well when only looking for 'real' internet addresses.

Things that will (and should) fail:

0.1.2.3         (0.0.0.0/8 is reserved for some broadcasts)
10.1.2.3        (10.0.0.0/8 is considered private)
172.16.1.2      (172.16.0.0/12 is considered private)
172.31.1.2      (same as previous, but near the end of that range)
192.168.1.2     (192.168.0.0/16 is considered private)
255.255.255.255 (reserved broadcast is not an IP)
.2.3.4
1.2.3.
1.2.3.256
1.2.256.4
1.256.3.4
256.2.3.4
1.2.3.4.5
1..3.4

IPs that will (and should) work:

1.0.1.0         (China)
8.8.8.8         (Google DNS in USA)
100.1.2.3       (USA)
172.15.1.2      (USA)
172.32.1.2      (USA)
192.167.1.2     (Italy)

Provided in case anybody else is looking for validating 'Internet IP addresses not including the common private addresses'

Python Replace \\ with \

Your original string, a = 'a\\nb' does not actually have two '\' characters, the first one is an escape for the latter. If you do, print a, you'll see that you actually have only one '\' character.

>>> a = 'a\\nb'
>>> print a
a\nb

If, however, what you mean is to interpret the '\n' as a newline character, without escaping the slash, then:

>>> b = a.replace('\\n', '\n')
>>> b
'a\nb'
>>> print b
a
b

Should I test private methods or only public ones?

I understand the point of view where private methods are considered as implementations details and then don't have to be tested. And I would stick with this rule if we had to develop outside of the object only. But us, are we some kind of restricted developers who are developing only outside of objects, calling only their public methods? Or are we actually also developing that object? As we are not bound to program outside objects, we will probably have to call those private methods into new public ones we are developing. Wouldn't it be great to know that the private method resist against all odds?

I know some people could answer that if we are developing another public method into that object then this one should be tested and that's it (the private method could carry on living without test). But this is also true for any public methods of an object: when developing a web app, all the public methods of an object are called from controllers methods and hence could be considered as implementation details for controllers.

So why are we unit testing objects? Because it is really difficult, not to say impossible to be sure that we are testing the controllers' methods with the appropriate input which will trigger all the branches of the underlying code. In other words, the higher we are in the stack, the more difficult it is to test all the behaviour. And so is the same for private methods.

To me the frontier between private and public methods is a psychologic criteria when it comes to tests. Criteria which matters more to me are:

  • is the method called more than once from different places?
  • is the method sophisticated enough to require tests?

How do I concatenate two text files in PowerShell?

In cmd, you can do this:

copy one.txt+two.txt+three.txt four.txt

In PowerShell this would be:

cmd /c copy one.txt+two.txt+three.txt four.txt

While the PowerShell way would be to use gc, the above will be pretty fast, especially for large files. And it can be used on on non-ASCII files too using the /B switch.

Better way to convert file sizes in Python

Instead of a size divisor of 1024 * 1024 you could use the << bitwise shifting operator, i.e. 1<<20 to get megabytes, 1<<30 to get gigabytes, etc.

In the simplest scenario you can have e.g. a constant MBFACTOR = float(1<<20) which can then be used with bytes, i.e.: megas = size_in_bytes/MBFACTOR.

Megabytes are usually all that you need, or otherwise something like this can be used:

# bytes pretty-printing
UNITS_MAPPING = [
    (1<<50, ' PB'),
    (1<<40, ' TB'),
    (1<<30, ' GB'),
    (1<<20, ' MB'),
    (1<<10, ' KB'),
    (1, (' byte', ' bytes')),
]


def pretty_size(bytes, units=UNITS_MAPPING):
    """Get human-readable file sizes.
    simplified version of https://pypi.python.org/pypi/hurry.filesize/
    """
    for factor, suffix in units:
        if bytes >= factor:
            break
    amount = int(bytes / factor)

    if isinstance(suffix, tuple):
        singular, multiple = suffix
        if amount == 1:
            suffix = singular
        else:
            suffix = multiple
    return str(amount) + suffix

print(pretty_size(1))
print(pretty_size(42))
print(pretty_size(4096))
print(pretty_size(238048577))
print(pretty_size(334073741824))
print(pretty_size(96995116277763))
print(pretty_size(3125899904842624))

## [Out] ###########################
1 byte
42 bytes
4 KB
227 MB
311 GB
88 TB
2 PB

How to create a zip archive with PowerShell?

If you head on over to CodePlex and grab the PowerShell Community Extensions, you can use their write-zip cmdlet.

Since

CodePlex is in read-only mode in preparation for shutdown

you can go to PowerShell Gallery.

SQL SELECT everything after a certain character

Try this in MySQL.

right(field,((CHAR_LENGTH(field))-(InStr(field,','))))

Laravel Eloquent where field is X or null

It sounds like you need to make use of advanced where clauses.

Given that search in field1 and field2 is constant we will leave them as is, but we are going to adjust your search in datefield a little.

Try this:

$query = Model::where('field1', 1)
    ->whereNull('field2')
    ->where(function ($query) {
        $query->where('datefield', '<', $date)
            ->orWhereNull('datefield');
    }
);

If you ever need to debug a query and see why it isn't working, it can help to see what SQL it is actually executing. You can chain ->toSql() to the end of your eloquent query to generate the SQL.

Changing the image source using jQuery

I had the same problem when trying to call re captcha button. After some searching, now the below function works fine in almost all the famous browsers(chrome,Firefox,IE,Edge,...):

function recaptcha(theUrl) {
  $.get(theUrl, function(data, status){});
  $("#captcha-img").attr('src', "");
  setTimeout(function(){
       $("#captcha-img").attr('src', "captcha?"+new Date().getTime());
  }, 0);
 }

'theUrl' is used to render new captcha image and can be ignored in your case. The most important point is generating new URL which forces FF and IE to rerender the image.

Converting UTF-8 to ISO-8859-1 in Java - how to keep it as single byte

In addition to Adam Rosenfield's answer, I would like to add that ByteBuffer.array() returns the buffer's underlying byte array, which is not necessarily "trimmed" up to the last character. Extra manipulation will be needed, such as the ones mentioned in this answer; in particular:

byte[] b = new byte[bb.remaining()]
bb.get(b);

A warning - comparison between signed and unsigned integer expressions

The primary issue is that underlying hardware, the CPU, only has instructions to compare two signed values or compare two unsigned values. If you pass the unsigned comparison instruction a signed, negative value, it will treat it as a large positive number. So, -1, the bit pattern with all bits on (twos complement), becomes the maximum unsigned value for the same number of bits.

8-bits: -1 signed is the same bits as 255 unsigned 16-bits: -1 signed is the same bits as 65535 unsigned etc.

So, if you have the following code:

int fd;
fd = open( .... );

int cnt;
SomeType buf;

cnt = read( fd, &buf, sizeof(buf) );

if( cnt < sizeof(buf) ) {
    perror("read error");
}

you will find that if the read(2) call fails due to the file descriptor becoming invalid (or some other error), that cnt will be set to -1. When comparing to sizeof(buf), an unsigned value, the if() statement will be false because 0xffffffff is not less than sizeof() some (reasonable, not concocted to be max size) data structure.

Thus, you have to write the above if, to remove the signed/unsigned warning as:

if( cnt < 0 || (size_t)cnt < sizeof(buf) ) {
    perror("read error");
}

This just speaks loudly to the problems.

1.  Introduction of size_t and other datatypes was crafted to mostly work, 
    not engineered, with language changes, to be explicitly robust and 
    fool proof.
2.  Overall, C/C++ data types should just be signed, as Java correctly
    implemented.

If you have values so large that you can't find a signed value type that works, you are using too small of a processor or too large of a magnitude of values in your language of choice. If, like with money, every digit counts, there are systems to use in most languages which provide you infinite digits of precision. C/C++ just doesn't do this well, and you have to be very explicit about everything around types as mentioned in many of the other answers here.

How to get the groups of a user in Active Directory? (c#, asp.net)

First of all, GetAuthorizationGroups() is a great function but unfortunately has 2 disadvantages:

  1. Performance is poor, especially in big company's with many users and groups. It fetches a lot more data then you actually need and does a server call for each loop iteration in the result
  2. It contains bugs which can cause your application to stop working 'some day' when groups and users are evolving. Microsoft recognized the issue and is related with some SID's. The error you'll get is "An error occurred while enumerating the groups"

Therefore, I've wrote a small function to replace GetAuthorizationGroups() with better performance and error-safe. It does only 1 LDAP call with a query using indexed fields. It can be easily extended if you need more properties than only the group names ("cn" property).

// Usage: GetAdGroupsForUser2("domain\user") or GetAdGroupsForUser2("user","domain")
public static List<string> GetAdGroupsForUser2(string userName, string domainName = null)
{
    var result = new List<string>();

    if (userName.Contains('\\') || userName.Contains('/'))
    {
        domainName = userName.Split(new char[] { '\\', '/' })[0];
        userName = userName.Split(new char[] { '\\', '/' })[1];
    }

    using (PrincipalContext domainContext = new PrincipalContext(ContextType.Domain, domainName))
        using (UserPrincipal user = UserPrincipal.FindByIdentity(domainContext, userName))
            using (var searcher = new DirectorySearcher(new DirectoryEntry("LDAP://" + domainContext.Name)))
            {
                searcher.Filter = String.Format("(&(objectCategory=group)(member={0}))", user.DistinguishedName);
                searcher.SearchScope = SearchScope.Subtree;
                searcher.PropertiesToLoad.Add("cn");

                foreach (SearchResult entry in searcher.FindAll())
                    if (entry.Properties.Contains("cn"))
                        result.Add(entry.Properties["cn"][0].ToString());
            }

    return result;
}

How do you put an image file in a json object?

public class UploadToServer extends Activity {

TextView messageText;
Button uploadButton;
int serverResponseCode = 0;
ProgressDialog dialog = null;

String upLoadServerUri = null;

/********** File Path *************/
final String uploadFilePath = "/mnt/sdcard/";
final String uploadFileName = "Quotes.jpg";

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_upload_to_server);

    uploadButton = (Button) findViewById(R.id.uploadButton);
    messageText = (TextView) findViewById(R.id.messageText);

    messageText.setText("Uploading file path :- '/mnt/sdcard/"
            + uploadFileName + "'");

    /************* Php script path ****************/
    upLoadServerUri = "http://192.1.1.11/hhhh/UploadToServer.php";

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

            dialog = ProgressDialog.show(UploadToServer.this, "",
                    "Uploading file...", true);

            new Thread(new Runnable() {
                public void run() {
                    runOnUiThread(new Runnable() {
                        public void run() {
                            messageText.setText("uploading started.....");
                        }
                    });

                    uploadFile(uploadFilePath + "" + uploadFileName);

                }
            }).start();
        }
    });
}

public int uploadFile(String sourceFileUri) {

    String fileName = sourceFileUri;

    HttpURLConnection connection = null;
    DataOutputStream dos = null;
    String lineEnd = "\r\n";
    String twoHyphens = "--";
    String boundary = "*****";
    int bytesRead, bytesAvailable, bufferSize;
    byte[] buffer;
    int maxBufferSize = 1 * 1024 * 1024;
    File sourceFile = new File(sourceFileUri);

    if (!sourceFile.isFile()) {

        dialog.dismiss();

        Log.e("uploadFile", "Source File not exist :" + uploadFilePath + ""
                + uploadFileName);

        runOnUiThread(new Runnable() {
            public void run() {
                messageText.setText("Source File not exist :"
                        + uploadFilePath + "" + uploadFileName);
            }
        });

        return 0;

    } else {
        try {

            // open a URL connection to the Servlet
            FileInputStream fileInputStream = new FileInputStream(
                    sourceFile);
            URL url = new URL(upLoadServerUri);

            // Open a HTTP connection to the URL
            connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true); // Allow Inputs
            connection.setDoOutput(true); // Allow Outputs
            connection.setUseCaches(false); // Don't use a Cached Copy
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setRequestProperty("ENCTYPE", "multipart/form-data");
            connection.setRequestProperty("Content-Type",
                    "multipart/form-data;boundary=" + boundary);
            connection.setRequestProperty("uploaded_file", fileName);

            dos = new DataOutputStream(connection.getOutputStream());

            dos.writeBytes(twoHyphens + boundary + lineEnd);
            // dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
            // + fileName + "\"" + lineEnd);
            dos.writeBytes("Content-Disposition: post-data; name=uploadedfile;filename="
                    + URLEncoder.encode(fileName, "UTF-8") + lineEnd);

            dos.writeBytes(lineEnd);

            // create a buffer of maximum size
            bytesAvailable = fileInputStream.available();

            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];

            // read file and write it into form...
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            while (bytesRead > 0) {

                dos.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            }

            // send multipart form data necesssary after file data...
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);

            // Responses from the server (code and message)
            int serverResponseCode = connection.getResponseCode();
            String serverResponseMessage = connection.getResponseMessage();

            Log.i("uploadFile", "HTTP Response is : "
                    + serverResponseMessage + ": " + serverResponseCode);

            if (serverResponseCode == 200) {

                runOnUiThread(new Runnable() {
                    public void run() {

                        String msg = "File Upload Completed.\n\n See uploaded file here : \n\n"
                                + " http://www.androidexample.com/media/uploads/"
                                + uploadFileName;

                        messageText.setText(msg);
                        Toast.makeText(UploadToServer.this,
                                "File Upload Complete.", Toast.LENGTH_SHORT)
                                .show();
                    }
                });
            }

            // close the streams //
            fileInputStream.close();
            dos.flush();
            dos.close();

        } catch (MalformedURLException ex) {

            dialog.dismiss();
            ex.printStackTrace();

            runOnUiThread(new Runnable() {
                public void run() {
                    messageText
                            .setText("MalformedURLException Exception : check script url.");
                    Toast.makeText(UploadToServer.this,
                            "MalformedURLException", Toast.LENGTH_SHORT)
                            .show();
                }
            });

            Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
        } catch (Exception e) {

            dialog.dismiss();
            e.printStackTrace();

            runOnUiThread(new Runnable() {
                public void run() {
                    messageText.setText("Got Exception : see logcat ");
                    Toast.makeText(UploadToServer.this,
                            "Got Exception : see logcat ",
                            Toast.LENGTH_SHORT).show();
                }
            });
            Log.e("Upload file to server Exception",
                    "Exception : " + e.getMessage(), e);
        }
        dialog.dismiss();
        return serverResponseCode;

    } // End else block
}

PHP File

<?php
$target_path  = "./Upload/";
$target_path = $target_path . basename( $_FILES['uploadedfile']['name']);

if(move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
    echo "The file ".  basename( $_FILES['uploadedfile']['name']).    " has been uploaded";
} else {
    echo "There was an error uploading the file, please try again!";
}

?>

Just disable scroll not hide it?

This is the solution we went with. Simply save the scroll position when the overlay is opened, scroll back to the saved position any time the user attempted to scroll the page, and turn the listener off when the overlay is closed.

It's a bit jumpy on IE, but works like a charm on Firefox/Chrome.

_x000D_
_x000D_
var body = $("body"),_x000D_
  overlay = $("#overlay"),_x000D_
  overlayShown = false,_x000D_
  overlayScrollListener = null,_x000D_
  overlaySavedScrollTop = 0,_x000D_
  overlaySavedScrollLeft = 0;_x000D_
_x000D_
function showOverlay() {_x000D_
  overlayShown = true;_x000D_
_x000D_
  // Show overlay_x000D_
  overlay.addClass("overlay-shown");_x000D_
_x000D_
  // Save scroll position_x000D_
  overlaySavedScrollTop = body.scrollTop();_x000D_
  overlaySavedScrollLeft = body.scrollLeft();_x000D_
_x000D_
  // Listen for scroll event_x000D_
  overlayScrollListener = body.scroll(function() {_x000D_
    // Scroll back to saved position_x000D_
    body.scrollTop(overlaySavedScrollTop);_x000D_
    body.scrollLeft(overlaySavedScrollLeft);_x000D_
  });_x000D_
}_x000D_
_x000D_
function hideOverlay() {_x000D_
  overlayShown = false;_x000D_
_x000D_
  // Hide overlay_x000D_
  overlay.removeClass("overlay-shown");_x000D_
_x000D_
  // Turn scroll listener off_x000D_
  if (overlayScrollListener) {_x000D_
    overlayScrollListener.off();_x000D_
    overlayScrollListener = null;_x000D_
  }_x000D_
}_x000D_
_x000D_
// Click toggles overlay_x000D_
$(window).click(function() {_x000D_
  if (!overlayShown) {_x000D_
    showOverlay();_x000D_
  } else {_x000D_
    hideOverlay();_x000D_
  }_x000D_
});
_x000D_
/* Required */_x000D_
html, body { margin: 0; padding: 0; height: 100%; background: #fff; }_x000D_
html { overflow: hidden; }_x000D_
body { overflow-y: scroll; }_x000D_
_x000D_
/* Just for looks */_x000D_
.spacer { height: 300%; background: orange; background: linear-gradient(#ff0, #f0f); }_x000D_
.overlay { position: fixed; top: 20px; bottom: 20px; left: 20px; right: 20px; z-index: -1; background: #fff; box-shadow: 0 0 5px rgba(0, 0, 0, .3); overflow: auto; }_x000D_
.overlay .spacer { background: linear-gradient(#88f, #0ff); }_x000D_
.overlay-shown { z-index: 1; }
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
_x000D_
<h1>Top of page</h1>_x000D_
<p>Click to toggle overlay. (This is only scrollable when overlay is <em>not</em> open.)</p>_x000D_
<div class="spacer"></div>_x000D_
<h1>Bottom of page</h1>_x000D_
<div id="overlay" class="overlay">_x000D_
  <h1>Top of overlay</h1>_x000D_
  <p>Click to toggle overlay. (Containing page is no longer scrollable, but this is.)</p>_x000D_
  <div class="spacer"></div>_x000D_
  <h1>Bottom of overlay</h1>_x000D_
</div>
_x000D_
_x000D_
_x000D_

using javascript to detect whether the url exists before display in iframe

I found this worked in my scenario.

The jqXHR.success(), jqXHR.error(), and jqXHR.complete() callback methods introduced in jQuery 1.5 are deprecated as of jQuery 1.8. To prepare your code for their eventual removal, use jqXHR.done(), jqXHR.fail(), and jqXHR.always() instead.

$.get("urlToCheck.com").done(function () {
  alert("success");
}).fail(function () {
   alert("failed.");
});

How to plot an array in python?

if you give a 2D array to the plot function of matplotlib it will assume the columns to be lines:

If x and/or y is 2-dimensional, then the corresponding columns will be plotted.

In your case your shape is not accepted (100, 1, 1, 8000). As so you can using numpy squeeze to solve the problem quickly:

np.squeez doc: Remove single-dimensional entries from the shape of an array.

import numpy as np
import matplotlib.pyplot as plt

data = np.random.randint(3, 7, (10, 1, 1, 80))
newdata = np.squeeze(data) # Shape is now: (10, 80)
plt.plot(newdata) # plotting by columns
plt.show()

But notice that 100 sets of 80 000 points is a lot of data for matplotlib. I would recommend that you look for an alternative. The result of the code example (run in Jupyter) is:

Jupyter matplotlib plot

SQL Server - find nth occurrence in a string

You can use the following function to split the values by a delimiter. It'll return a table and to find the nth occurrence just make a select on it! Or change it a little for it to return what you need instead of the table.

CREATE FUNCTION dbo.Split
(
    @RowData nvarchar(2000),
    @SplitOn nvarchar(5)
)  
RETURNS @RtnValue table 
(
    Id int identity(1,1),
    Data nvarchar(100)
) 
AS  
BEGIN 
    Declare @Cnt int
    Set @Cnt = 1

    While (Charindex(@SplitOn,@RowData)>0)
    Begin
        Insert Into @RtnValue (data)
        Select 
            Data = ltrim(rtrim(Substring(@RowData,1,Charindex(@SplitOn,@RowData)-1)))

        Set @RowData = Substring(@RowData,Charindex(@SplitOn,@RowData)+1,len(@RowData))
        Set @Cnt = @Cnt + 1
    End

    Insert Into @RtnValue (data)
    Select Data = ltrim(rtrim(@RowData))

    Return
END

preferredStatusBarStyle isn't called

The NavigationController or TabBarController are the ones that need to provide the style. Here is how I solved: https://stackoverflow.com/a/39072526/242769

Horizontal scroll on overflow of table

I think your overflow should be on the outer container. You can also explicitly set a min width for the columns. Like this:

.search-table-outter { overflow-x: scroll; }
th, td { min-width: 200px; }

Fiddle: http://jsfiddle.net/5WsEt/

error CS0234: The type or namespace name 'Script' does not exist in the namespace 'System.Web'

Since JsonSerializer is deprecated in .Net 4.0+ I used http://www.newtonsoft.com/json to solve this issue.

NuGet- > Install-Package Newtonsoft.Json

Exclude property from type

In Typescript 3.5+:

interface TypographyProps {
    variant: string
    fontSize: number
}

type TypographyPropsMinusVariant = Omit<TypographyProps, "variant">

BeanFactory vs ApplicationContext

BeanFactory and ApplicationContext both are ways to get beans from your spring IOC container but still there are some difference.

BeanFactory is the actual container which instantiates, configures, and manages a number of bean's. These beans are typically collaborate with one another, and thus have dependencies between themselves. These dependencies are reflected in the configuration data used by the BeanFactory.

BeanFactory and ApplicationContext both are Java interfaces and ApplicationContext extends BeanFactory. Both of them are configuration using XML configuration files. In short BeanFactory provides basic Inversion of control(IoC) and Dependency Injection (DI) features while ApplicationContext provides advanced features.

A BeanFactory is represented by the interface "org.springframework.beans.factory" Where BeanFactory, for which there are multiple implementations.

ClassPathResource resource = new ClassPathResource("appConfig.xml");
XmlBeanFactory factory = new XmlBeanFactory(resource);

DIFFERENCE

  1. BeanFactory instantiate bean when you call getBean() method while ApplicationContext instantiate Singleton bean when container is started, It doesn't wait for getBean() to be called.

  2. BeanFactory doesn't provide support for internationalization but ApplicationContext provides support for it.

  3. Another difference between BeanFactory vs ApplicationContext is ability to publish event to beans that are registered as listener.

  4. One of the popular implementation of BeanFactory interface is XMLBeanFactory while one of the popular implementation of ApplicationContext interface is ClassPathXmlApplicationContext.

  5. If you are using auto wiring and using BeanFactory than you need to register AutoWiredBeanPostProcessor using API which you can configure in XML if you are using ApplicationContext. In summary BeanFactory is OK for testing and non production use but ApplicationContext is more feature rich container implementation and should be favored over BeanFactory

  6. BeanFactory by default its support Lazy loading and ApplicationContext by default support Aggresive loading.

How to delete object from array inside foreach loop?

You can also use references on foreach values:

foreach($array as $elementKey => &$element) {
    // $element is the same than &$array[$elementKey]
    if (isset($element['id']) and $element['id'] == 'searched_value') {
        unset($element);
    }
}

Display current time in 12 hour format with AM/PM

Just replace below statement and it will work.

SimpleDateFormat formatDate = new SimpleDateFormat("hh:mm a");

Background image jumps when address bar hides iOS/Android/Mobile Chrome

My answer is for everyone who comes here (like I did) to find an answer for a bug caused by the hiding address bare / browser interface.

The hiding address bar causes the resize-event to trigger. But different than other resize-events, like switching to landscape mode, this doesn't change the width of the window. So my solution is to hook into the resize event and check if the width is the same.

// Keep track of window width
let myWindowWidth = window.innerWidth;

window.addEventListener( 'resize', function(event) {

    // If width is the same, assume hiding address bar
    if( myWindowWidth == window.innerWidth ) {
         return;
    }

    // Update the window width
    myWindowWidth = window.innerWidth;

    // Do your thing
    // ...
});

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25

Try to set the property when starting JVM, for example, add -Djava.net.preferIPv4Stack=true.

You can't set it when code running, as the java.net just read it when jvm starting.

And about the root cause, this article give some hint: Why do I need java.net.preferIPv4Stack=true only on some windows 7 systems?.

Getting a 'source: not found' error when using source in a bash script

In the POSIX standard, which /bin/sh is supposed to respect, the command is . (a single dot), not source. The source command is a csh-ism that has been pulled into bash.

Try

. $env_name/bin/activate

Or if you must have non-POSIX bash-isms in your code, use #!/bin/bash.

How do I import a namespace in Razor View Page?

For Library

@using MyNamespace

For Model

@model MyModel

JavaScript: How to find out if the user browser is Chrome?

_x000D_
_x000D_
console.log(JSON.stringify({_x000D_
  isAndroid: /Android/.test(navigator.userAgent),_x000D_
  isCordova: !!window.cordova,_x000D_
  isEdge: /Edge/.test(navigator.userAgent),_x000D_
  isFirefox: /Firefox/.test(navigator.userAgent),_x000D_
  isChrome: /Google Inc/.test(navigator.vendor),_x000D_
  isChromeIOS: /CriOS/.test(navigator.userAgent),_x000D_
  isChromiumBased: !!window.chrome && !/Edge/.test(navigator.userAgent),_x000D_
  isIE: /Trident/.test(navigator.userAgent),_x000D_
  isIOS: /(iPhone|iPad|iPod)/.test(navigator.platform),_x000D_
  isOpera: /OPR/.test(navigator.userAgent),_x000D_
  isSafari: /Safari/.test(navigator.userAgent) && !/Chrome/.test(navigator.userAgent),_x000D_
  isTouchScreen: ('ontouchstart' in window) || window.DocumentTouch && document instanceof DocumentTouch,_x000D_
  isWebComponentsSupported: 'registerElement' in document && 'import' in document.createElement('link') && 'content' in document.createElement('template')_x000D_
}, null, '  '));
_x000D_
_x000D_
_x000D_

How to disable phone number linking in Mobile Safari?

Why would you want to remove the linking, it makes it very user friendly to have th eoption.

If you simply want to remove the auto editing, but keep the link working just add this into your CSS...

a[href^=tel] {
 color: inherit;
 text-decoration:inherit;
}

Count immediate child div elements using jQuery

$("#foo > div") 

selects all divs that are immediate descendants of #foo
once you have the set of children you can either use the size function:

$("#foo > div").size()

or you can use

$("#foo > div").length

Both will return you the same result

Cocoa: What's the difference between the frame and the bounds?

try to run the code below

- (void)viewDidLoad {
    [super viewDidLoad];
    UIWindow *w = [[UIApplication sharedApplication] keyWindow];
    UIView *v = [w.subviews objectAtIndex:0];

    NSLog(@"%@", NSStringFromCGRect(v.frame));
    NSLog(@"%@", NSStringFromCGRect(v.bounds));
}

the output of this code is:

case device orientation is Portrait

{{0, 0}, {768, 1024}}
{{0, 0}, {768, 1024}}

case device orientation is Landscape

{{0, 0}, {768, 1024}}
{{0, 0}, {1024, 768}}

obviously, you can see the difference between frame and bounds

Clearfix with twitter bootstrap

clearfix should contain the floating elements but in your html you have added clearfix only after floating right that is your pull-right so you should do like this:

<div class="clearfix">
  <div id="sidebar">
    <ul>
      <li>A</li>
      <li>A</li>
      <li>C</li>
      <li>D</li>
      <li>E</li>
      <li>F</li>
      <li>...</li>
      <li>Z</li>
    </ul>
  </div>
  <div id="main">
    <div>
      <div class="pull-right">
        <a>RIGHT</a>
      </div>
    </div>
  <div>MOVED BELOW Z</div>
</div>

see this demo


Happy to know you solved the problem by setting overflow properties. However this is also good idea to clear the float. Where you have floated your elements you could add overflow: hidden; as you have done in your main.

How to get current user, and how to use User class in MVC5?

I feel your pain, I'm trying to do the same thing. In my case I just want to clear the user.

I've created a base controller class that all my controllers inherit from. In it I override OnAuthentication and set the filterContext.HttpContext.User to null

That's the best I've managed to far...

public abstract class ApplicationController : Controller   
{
    ...
    protected override void OnAuthentication(AuthenticationContext filterContext)
    {
        base.OnAuthentication(filterContext); 

        if ( ... )
        {
            // You may find that modifying the 
            // filterContext.HttpContext.User 
            // here works as desired. 
            // In my case I just set it to null
            filterContext.HttpContext.User = null;
        }
    }
    ...
}

Create or update mapping in elasticsearch

In later Elasticsearch versions (7.x), types were removed. Updating a mapping can becomes:

curl -XPUT "http://localhost:9200/test/_mapping" -H 'Content-Type: application/json' -d'{
  "properties": {
    "new_geo_field": {
      "type": "geo_point"
    }
  }
}'

As others have pointed out, if the field exists, you typically have to reindex. There are exceptions, such as adding a new sub-field or changing analysis settings.

You can't "create a mapping", as the mapping is created with the index. Typically, you'd define the mapping when creating the index (or via index templates):

curl -XPUT "http://localhost:9200/test" -H 'Content-Type: application/json' -d'{
  "mappings": {
    "properties": {
      "foo_field": {
        "type": "text"
      }
    }
  }
}'

That's because, in production at least, you'd want to avoid letting Elasticsearch "guess" new fields. Which is what generated this question: geo data was read as an array of long values.

.htaccess not working apache

Go to /etc/apache2/apache2.conf

You have to edit that file (you should have root permission). Change directory text as bellow:

<Directory /var/www/>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted

Now you have to restart apache.

service apache2 restart

CSS horizontal scroll

Use this code to generate horizontal scrolling blocks contents. I got this from here http://www.htmlexplorer.com/2014/02/horizontal-scrolling-webpage-content.html

<html>
<title>HTMLExplorer Demo: Horizontal Scrolling Content</title>
<head>
<style type="text/css">
#outer_wrapper {  
    overflow: scroll;  
    width:100%;
}
#outer_wrapper #inner_wrapper {
    width:6000px; /* If you have more elements, increase the width accordingly */
}
#outer_wrapper #inner_wrapper div.box { /* Define the properties of inner block */
    width: 250px;
    height:300px;
    float: left;
    margin: 0 4px 0 0;
    border:1px grey solid;
}
</style>
</head>
<body>

<div id="outer_wrapper">
    <div id="inner_wrapper">
        <div class="box">
            <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <div class="box">
             <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <div class="box">
            <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <div class="box">
            <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <div class="box">
             <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <div class="box">
            <!-- Add desired content here -->
            HTMLExplorer.com - Explores HTML, CSS, Jquery, XML, PHP, JSON, Javascript 
        </div>
        <!-- more boxes here -->
    </div>
</div>
</body>
</html>

How do I change the IntelliJ IDEA default JDK?

The above responses were very useful, but after all settings, the project was running with the wrong version. Finally, I noticed that it can be also configured in the Dependencies window. Idea 2018.1.3 File -> Project Structure -> Modules -> Sources and Dependencies.

How do I clear the content of a div using JavaScript?

Just Javascript (as requested)

Add this function somewhere on your page (preferably in the <head>)

function clearBox(elementID)
{
    document.getElementById(elementID).innerHTML = "";
}

Then add the button on click event:

<button onclick="clearBox('cart_item')" />

In JQuery (for reference)

If you prefer JQuery you could do:

$("#cart_item").html("");

Reloading/refreshing Kendo Grid

What you have to do is just add an event .Events(events => events.Sync("KendoGridRefresh")) in your kendoGrid binding code.No need to write the refresh code in ajax result.

@(Html.Kendo().Grid<Models.DocumentDetail>().Name("document")
    .DataSource(dataSource => dataSource
    .Ajax()
    .PageSize(20)
    .Model(model => model.Id(m => m.Id))        
    .Events(events => events.Sync("KendoGridRefresh"))    
    )
      .Columns(columns =>
      {
          columns.Bound(c => c.Id).Hidden();              
          columns.Bound(c => c.UserName).Title(@Resources.Resource.lblAddedBy);                           
      }).Events(e => e.DataBound("onRowBound"))
          .ToolBar(toolbar => toolbar.Create().Text(@Resources.Resource.lblNewDocument))
          .Sortable()          
          .HtmlAttributes(new { style = "height:260px" })          
  )

And you can add the following Global function in any of your .js file. so, you can call it for all the kendo grids in your project to refresh the kendoGrid.

function KendoGridRefresh() {
    var grid = $('#document').data('kendoGrid');
    grid.dataSource.read();
}

WSDL vs REST Pros and Cons

In defence of REST it closely follows the principles of HTTP and addressability e.g. read operations use GET, update operations use POST etc. I find this to be a far cleaner approach. The Oreilly book RESTful Web Services explains this far better than I can, if you read it I think you would prefer the REST approach

String in function parameter

function("MyString");

is similar to

char *s = "MyString";
function(s);

"MyString" is in both cases a string literal and in both cases the string is unmodifiable.

function("MyString");

passes the address of a string literal to function as an argument.

Error executing command 'ant' on Mac OS X 10.9 Mavericks when building for Android with PhoneGap/Cordova

I encountered the same issue when trying to use Cordova. Turns out I already had brew, try which brew, but it was outdated. So, I had to update it first:

  1. Update brew: brew update
  2. Install Apache Ant: brew install ant

Best Way to read rss feed in .net Using C#

You're looking for the SyndicationFeed class, which does exactly that.

error: expected declaration or statement at end of input in c

You probably have syntax error. You most likely forgot to put a } or ; somewhere above this function.

jQuery Button.click() event is triggered twice

in my case, i was using the change command like this way

$(document).on('change', '.select-brand', function () {...my codes...});

and then i changed the way to

$('.select-brand').on('change', function () {...my codes...});

and it solved my problem.

How to change the port number for Asp.Net core app?

in appsetting.json

{ "DebugMode": false, "Urls": "http://localhost:8082" }

Does IMDB provide an API?

The IMDb has a public API that, although undocumented, is fast and reliable (used on the official website through AJAX).

Search Suggestions API

// 1) Vanilla JavaScript (JSON-P)
function addScript(src) { var s = document.createElement('script'); s.src = src; document.head.appendChild(s); }
window.imdb$foo = function (results) {
  /* ... */
};
addScript('https://sg.media-imdb.com/suggests/f/foo.json');

// 2) Using jQuery (JSON-P)
jQuery.ajax({
    url: 'https://sg.media-imdb.com/suggests/f/foo.json',
    dataType: 'jsonp',
    cache: true,
    jsonp: false,
    jsonpCallback: 'imdb$foo'
}).then(function (results) {
    /* ... */
});

// 3) Pure JSON (with jQuery)
// Use a local proxy that strips the "padding" of JSON-P,
// e.g. "imdb$foo(" and ")", leaving pure JSON only.
jQuery.getJSON('/api/imdb/?q=foo', function (results) {
    /* ... */
});

// 4) Pure JSON (ES2017 and Fetch API)
// Using a custom proxy at "/api" that strips the JSON-P padding.
const resp = await fetch('/api/imdb/?q=foo');
const results = await resp.json();

Advanced Search


Beware that these APIs are unofficial and could change at any time!


Update (January 2019): The Advanced API no longer exists. The good news is, that the Suggestions API now supports the "advanced" features of searching by film titles and actor names as well.

Printing result of mysql query from variable

This will print out the query:

$query = "SELECT order_date, no_of_items, shipping_charge, SUM(total_order_amount) as test FROM `orders` WHERE DATE(`order_date`) = DATE(NOW()) GROUP BY DATE(`order_date`)";

$dave= mysql_query($query) or die(mysql_error());
print $query;

This will print out the results:

$query = "SELECT order_date, no_of_items, shipping_charge, SUM(total_order_amount) as test FROM `orders` WHERE DATE(`order_date`) = DATE(NOW()) GROUP BY DATE(`order_date`)";

$dave= mysql_query($query) or die(mysql_error());

while($row = mysql_fetch_assoc($dave)){
    foreach($row as $cname => $cvalue){
        print "$cname: $cvalue\t";
    }
    print "\r\n";
}

How to present UIActionSheet iOS Swift?

Your Approach is fine, but you can add UIActionSheet with other way with ease.

You can add UIActionSheetDelegate in UIViewController` like

class ViewController: UIViewController ,UIActionSheetDelegate

Set you method like,

@IBAction func downloadSheet(sender: AnyObject)
{

    let actionSheet = UIActionSheet(title: "Choose Option", delegate: self, cancelButtonTitle: "Cancel", destructiveButtonTitle: nil, otherButtonTitles: "Save", "Delete")

    actionSheet.showInView(self.view)
}

You can get your button index when it clicked like

func actionSheet(actionSheet: UIActionSheet, clickedButtonAtIndex buttonIndex: Int)
{
    println("\(buttonIndex)")
    switch (buttonIndex){

    case 0:
        println("Cancel")
    case 1:
        println("Save")
    case 2:
        println("Delete")
    default:
        println("Default")
        //Some code here..

    }
}

Update 1: for iOS8+

    //Create the AlertController and add Its action like button in Actionsheet
    let actionSheetControllerIOS8: UIAlertController = UIAlertController(title: "Please select", message: "Option to select", preferredStyle: .ActionSheet)

    let cancelActionButton = UIAlertAction(title: "Cancel", style: .cancel) { _ in
        print("Cancel")
    }
    actionSheetControllerIOS8.addAction(cancelActionButton)

    let saveActionButton = UIAlertAction(title: "Save", style: .default)
        { _ in
           print("Save")
    }
    actionSheetControllerIOS8.addAction(saveActionButton)

    let deleteActionButton = UIAlertAction(title: "Delete", style: .default)
        { _ in
            print("Delete")
    }
    actionSheetControllerIOS8.addAction(deleteActionButton)
    self.present(actionSheetControllerIOS8, animated: true, completion: nil)

Explode string by one or more spaces or tabs

@OP it doesn't matter, you can just split on a space with explode. Until you want to use those values, iterate over the exploded values and discard blanks.

$str = "A      B      C      D";
$s = explode(" ",$str);
foreach ($s as $a=>$b){    
    if ( trim($b) ) {
     print "using $b\n";
    }
}

Can I give a default value to parameters or optional parameters in C# functions?

This functionality is available from C# 4.0 - it was introduced in Visual Studio 2010. And you can use it in project for .NET 3.5. So there is no need to upgrade old projects in .NET 3.5 to .NET 4.0.

You have to just use Visual Studio 2010, but remember that it should compile to default language version (set it in project Properties->Buid->Advanced...)

This MSDN page has more information about optional parameters in VS 2010.

Pyinstaller setting icons don't change

I think this might have something to do with caching (possibly in Windows Explorer). I was having the old PyInstaller icon show up in a few places too, but when I copied the exe somewhere else, all the old icons were gone.

fatal error: iostream.h no such file or directory

Using standard C++ calling (note that you should use namespace std for cout or add using namespace std;)

#include <iostream>

int main()
{
    std::cout<<"Hello World!\n";
    return 0;
}

Center align "span" text inside a div

If you know the width of the span you could just stuff in a left margin.

Try this:

.center { text-align: center}
div.center span { display: table; }

Add the "center: class to your .

If you want some spans centered, but not others, replace the "div.center span" in your style sheet to a class (e.g "center-span") and add that class to the span.

SQL Server stored procedure creating temp table and inserting value

A SELECT INTO statement creates the table for you. There is no need for the CREATE TABLE statement before hand.

What is happening is that you create #ivmy_cash_temp1 in your CREATE statement, then the DB tries to create it for you when you do a SELECT INTO. This causes an error as it is trying to create a table that you have already created.

Either eliminate the CREATE TABLE statement or alter your query that fills it to use INSERT INTO SELECT format.

If you need a unique ID added to your new row then it's best to use SELECT INTO... since IDENTITY() only works with this syntax.

How to get a matplotlib Axes instance to plot to?

Use the gca ("get current axes") helper function:

ax = plt.gca()

Example:

import matplotlib.pyplot as plt
import matplotlib.finance
quotes = [(1, 5, 6, 7, 4), (2, 6, 9, 9, 6), (3, 9, 8, 10, 8), (4, 8, 8, 9, 8), (5, 8, 11, 13, 7)]
ax = plt.gca()
h = matplotlib.finance.candlestick(ax, quotes)
plt.show()

enter image description here

How can I increase the size of a bootstrap button?

Use block level buttons, those that span the full width of a parent You can achieve this by adding btn-block class your button element.

Documentation here

Find child element in AngularJS directive

In your link function, do this:

// link function
function (scope, element, attrs) {
  var myEl = angular.element(element[0].querySelector('.list-scrollable'));
}

Also, in your link function, don't name your scope variable using a $. That is an angular convention that is specific to built in angular services, and is not something that you want to use for your own variables.

Filename too long in Git for Windows

You should be able to run the command

git config --system core.longpaths true

or add it to one of your Git configuration files manually to turn this functionality on, once you are on a supported version of Git. It looks like maybe 1.9.0 and after.

Anchor links in Angularjs?

I had the same problem, but this worked for me:

<a ng-href="javascript:void(0);#tagId"></a>

How do I add a foreign key to an existing SQLite table?

You can try this:

ALTER TABLE [Child] ADD COLUMN column_name INTEGER REFERENCES parent_table_name(column_id);

TypeError: $(...).modal is not a function with bootstrap Modal

Check that jquery library not included in html that load via Ajax .remove <script src="~/Scripts/jquery[ver].js"></script> in your AjaxUpdate/get_modal

Image size (Python, OpenCV)

from this tutorial: https://www.tutorialkart.com/opencv/python/opencv-python-get-image-size/

import cv2

# read image
img = cv2.imread('/home/ubuntu/Walnut.jpg', cv2.IMREAD_UNCHANGED)

# get dimensions of image
dimensions = img.shape

# height, width, number of channels in image

height = img.shape[0]
width = img.shape[1]
channels = img.shape[2]

from this other tutorial: https://www.pyimagesearch.com/2018/07/19/opencv-tutorial-a-guide-to-learn-opencv/

image = cv2.imread("jp.png")

(h, w, d) = image.shape

Please double check things before posting answers.

django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: No module named MySQLdb

On Ubuntu it is advised to use the distributions repository.

sudo apt-get install python-mysqldb

C++ unordered_map using a custom class type as the key

To be able to use std::unordered_map (or one of the other unordered associative containers) with a user-defined key-type, you need to define two things:

  1. A hash function; this must be a class that overrides operator() and calculates the hash value given an object of the key-type. One particularly straight-forward way of doing this is to specialize the std::hash template for your key-type.

  2. A comparison function for equality; this is required because the hash cannot rely on the fact that the hash function will always provide a unique hash value for every distinct key (i.e., it needs to be able to deal with collisions), so it needs a way to compare two given keys for an exact match. You can implement this either as a class that overrides operator(), or as a specialization of std::equal, or – easiest of all – by overloading operator==() for your key type (as you did already).

The difficulty with the hash function is that if your key type consists of several members, you will usually have the hash function calculate hash values for the individual members, and then somehow combine them into one hash value for the entire object. For good performance (i.e., few collisions) you should think carefully about how to combine the individual hash values to ensure you avoid getting the same output for different objects too often.

A fairly good starting point for a hash function is one that uses bit shifting and bitwise XOR to combine the individual hash values. For example, assuming a key-type like this:

struct Key
{
  std::string first;
  std::string second;
  int         third;

  bool operator==(const Key &other) const
  { return (first == other.first
            && second == other.second
            && third == other.third);
  }
};

Here is a simple hash function (adapted from the one used in the cppreference example for user-defined hash functions):

namespace std {

  template <>
  struct hash<Key>
  {
    std::size_t operator()(const Key& k) const
    {
      using std::size_t;
      using std::hash;
      using std::string;

      // Compute individual hash values for first,
      // second and third and combine them using XOR
      // and bit shifting:

      return ((hash<string>()(k.first)
               ^ (hash<string>()(k.second) << 1)) >> 1)
               ^ (hash<int>()(k.third) << 1);
    }
  };

}

With this in place, you can instantiate a std::unordered_map for the key-type:

int main()
{
  std::unordered_map<Key,std::string> m6 = {
    { {"John", "Doe", 12}, "example"},
    { {"Mary", "Sue", 21}, "another"}
  };
}

It will automatically use std::hash<Key> as defined above for the hash value calculations, and the operator== defined as member function of Key for equality checks.

If you don't want to specialize template inside the std namespace (although it's perfectly legal in this case), you can define the hash function as a separate class and add it to the template argument list for the map:

struct KeyHasher
{
  std::size_t operator()(const Key& k) const
  {
    using std::size_t;
    using std::hash;
    using std::string;

    return ((hash<string>()(k.first)
             ^ (hash<string>()(k.second) << 1)) >> 1)
             ^ (hash<int>()(k.third) << 1);
  }
};

int main()
{
  std::unordered_map<Key,std::string,KeyHasher> m6 = {
    { {"John", "Doe", 12}, "example"},
    { {"Mary", "Sue", 21}, "another"}
  };
}

How to define a better hash function? As said above, defining a good hash function is important to avoid collisions and get good performance. For a real good one you need to take into account the distribution of possible values of all fields and define a hash function that projects that distribution to a space of possible results as wide and evenly distributed as possible.

This can be difficult; the XOR/bit-shifting method above is probably not a bad start. For a slightly better start, you may use the hash_value and hash_combine function template from the Boost library. The former acts in a similar way as std::hash for standard types (recently also including tuples and other useful standard types); the latter helps you combine individual hash values into one. Here is a rewrite of the hash function that uses the Boost helper functions:

#include <boost/functional/hash.hpp>

struct KeyHasher
{
  std::size_t operator()(const Key& k) const
  {
      using boost::hash_value;
      using boost::hash_combine;

      // Start with a hash value of 0    .
      std::size_t seed = 0;

      // Modify 'seed' by XORing and bit-shifting in
      // one member of 'Key' after the other:
      hash_combine(seed,hash_value(k.first));
      hash_combine(seed,hash_value(k.second));
      hash_combine(seed,hash_value(k.third));

      // Return the result.
      return seed;
  }
};

And here’s a rewrite that doesn’t use boost, yet uses good method of combining the hashes:

namespace std
{
    template <>
    struct hash<Key>
    {
        size_t operator()( const Key& k ) const
        {
            // Compute individual hash values for first, second and third
            // http://stackoverflow.com/a/1646913/126995
            size_t res = 17;
            res = res * 31 + hash<string>()( k.first );
            res = res * 31 + hash<string>()( k.second );
            res = res * 31 + hash<int>()( k.third );
            return res;
        }
    };
}

In c++ what does a tilde "~" before a function name signify?

It's a destructor. The function is guaranteed to be called when the object goes out of scope.

Arduino Sketch upload issue - avrdude: stk500_recv(): programmer is not responding

My problem was that I updated the Arduino IDE to a new version and did not reconnect the wire. Looks like that was the problem

Just disconnect the cable and connect again. Thanks.

How to fetch data from local JSON file on react native?

maybe you could use AsyncStorage setItem and getItem...and store the data as string, then use the json parser for convert it again to json...

DataGridView - Focus a specific cell

the problem with datagridview is that it select the first row automatically so you want to clear the selection by

grvPackingList.ClearSelection();
dataGridView1.Rows[rowindex].Cells[columnindex].Selected = true;  

other wise it will not work

How to access at request attributes in JSP?

EL expression:

${requestScope.Error_Message}

There are several implicit objects in JSP EL. See Expression Language under the "Implicit Objects" heading.

How can I send an email by Java application using GMail, Yahoo, or Hotmail?

My complete code as below is working well:

package ripon.java.mail;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;

public class SendEmail
{
public static void main(String [] args)
{    
    // Sender's email ID needs to be mentioned
     String from = "[email protected]";
     String pass ="test123";
    // Recipient's email ID needs to be mentioned.
   String to = "[email protected]";

   String host = "smtp.gmail.com";

   // Get system properties
   Properties properties = System.getProperties();
   // Setup mail server
   properties.put("mail.smtp.starttls.enable", "true");
   properties.put("mail.smtp.host", host);
   properties.put("mail.smtp.user", from);
   properties.put("mail.smtp.password", pass);
   properties.put("mail.smtp.port", "587");
   properties.put("mail.smtp.auth", "true");

   // Get the default Session object.
   Session session = Session.getDefaultInstance(properties);

   try{
      // Create a default MimeMessage object.
      MimeMessage message = new MimeMessage(session);

      // Set From: header field of the header.
      message.setFrom(new InternetAddress(from));

      // Set To: header field of the header.
      message.addRecipient(Message.RecipientType.TO,
                               new InternetAddress(to));

      // Set Subject: header field
      message.setSubject("This is the Subject Line!");

      // Now set the actual message
      message.setText("This is actual message");

      // Send message
      Transport transport = session.getTransport("smtp");
      transport.connect(host, from, pass);
      transport.sendMessage(message, message.getAllRecipients());
      transport.close();
      System.out.println("Sent message successfully....");
   }catch (MessagingException mex) {
      mex.printStackTrace();
   }
}
}

How can one run multiple versions of PHP 5.x on a development LAMP server?

Note: The following method will work on windows.

An alternative method (if it is ok to run a single version of PHP at a time) is to define multiple Apache services, each of which will use a different PHP version.

First of all use conditions in the Apache configuration file:

 <ifdefine php54>
    SetEnv PHPRC C:/apache/php54/
    ScriptAlias /php/ "C:/apache/php54/"
    AddType application/x-httpd-php .php
    Action application/x-httpd-php "/php/php-cgi.exe"
</ifdefine>

<ifdefine php55>
    SetEnv PHPRC C:/apache/php55/
    ScriptAlias /php/ "C:/apache/php55/"
    AddType application/x-httpd-php .php
    Action application/x-httpd-php "/php/php-cgi.exe"
</ifdefine>

Now using the httpd.exe create two separate services from command line (elevated to administrator):

httpd.exe -k install -n Apache224_php54 -D php54

httpd.exe -k install -n Apache224_php55 -D php55

Now you can start one of the above services at a time (should shutdown one before starting the other).

If you have previously installed Apache as service you can remove that using below command (replace the service name with the one you have used):

apache -k uninstall -n Apache224

One further note is that I personally use a "notification area icon program" called "Seobiseu" to start and stop services as needed. I have added the two above services to it.

How do I extract the contents of an rpm?

Most distributions have installed the GUI app file-roller which unpacks tar, zip, rpm and many more.

file-roller --extract-here package.rpm

This will extract the contents in the current directory.

Eclipse error: indirectly referenced from required .class files?

This is as likely a matter of Eclipse's getting confused as it is an actual error. I ignored the error and ran the web service whose endpointInterface it complained about, and it ran fine, except for having to deal with the dialog every time I wanted to run it. Just another opaque error that tells me nothing.

VBA: How to delete filtered rows in Excel?

As an alternative to using UsedRange or providing an explicit range address, the AutoFilter.Range property can also specify the affected range.

ActiveSheet.AutoFilter.Range.Offset(1,0).Rows.SpecialCells(xlCellTypeVisible).Delete(xlShiftUp)

As used here, Offset causes the first row after the AutoFilter range to also be deleted. In order to avoid that, I would try using .Resize() after .Offset().

How to copy a folder via cmd?

xcopy  e:\source_folder f:\destination_folder /e /i /h

The /h is just in case there are hidden files. The /i creates a destination folder if there are muliple source files.

How to get html table td cell value by JavaScript?

.......................

  <head>

    <title>Search students by courses/professors</title>

    <script type="text/javascript">

    function ChangeColor(tableRow, highLight)
    {
       if (highLight){
           tableRow.style.backgroundColor = '00CCCC';
       }

    else{
         tableRow.style.backgroundColor = 'white';
        }   
  }

  function DoNav(theUrl)
  {
  document.location.href = theUrl;
  }
  </script>

</head>
<body>

     <table id = "c" width="180" border="1" cellpadding="0" cellspacing="0">

            <% for (Course cs : courses){ %>

            <tr onmouseover="ChangeColor(this, true);" 
                onmouseout="ChangeColor(this, false);" 
                onclick="DoNav('http://localhost:8080/Mydata/ComplexSearch/FoundS.jsp?courseId=<%=cs.getCourseId()%>');">

                 <td name = "title" align = "center"><%= cs.getTitle() %></td>

            </tr>
           <%}%>

........................
</body>

I wrote the HTML table in JSP. Course is is a type. For example Course cs, cs= object of type Course which had 2 attributes: id, title. courses is an ArrayList of Course objects.

The HTML table displays all the courses titles in each cell. So the table has 1 column only: Course1 Course2 Course3 ...... Taking aside:

 onclick="DoNav('http://localhost:8080/Mydata/ComplexSearch/FoundS.jsp?courseId=<%=cs.getCourseId()%>');"

This means that after user selects a table cell, for example "Course2", the title of the course- "Course2" will travel to the page where the URL is directing the user: http://localhost:8080/Mydata/ComplexSearch/FoundS.jsp . "Course2" will arrive in FoundS.jsp page. The identifier of "Course2" is courseId. To declare the variable courseId, in which CourseX will be kept, you put a "?" after the URL and next to it the identifier. It works.

String is immutable. What exactly is the meaning?

Hope the below code would clarify your doubts :

public static void testString() {
    String str = "Hello";
    System.out.println("Before String Concat: "+str);
    str.concat("World");
    System.out.println("After String Concat: "+str);
    StringBuffer sb = new StringBuffer("Hello");
    System.out.println("Before StringBuffer Append: "+sb);
    sb.append("World");
    System.out.println("After StringBuffer Append: "+sb);
}

Before String Concat: Hello
After String Concat: Hello
Before StringBuffer Append: Hello
After StringBuffer Append: HelloWorld

"query function not defined for Select2 undefined error"

I also got the same error when using ajax with a textbox then i solve it by remove class select2 of textbox and setup select2 by id like:

$(function(){
  $("#input-select2").select2();
});

How to create a checkbox with a clickable label?

Use the label element, and the for attribute to associate it with the checkbox:

<label for="myCheckbox">Some checkbox</label> <input type="checkbox" id="myCheckbox" />

How to use code to open a modal in Angular 2?

I do not feel there is anything wrong with using JQuery with angular and bootstrap, since it is included when adding bootstrap.

  1. Add the $ right after the imports like this


import {.......

declare var $: any;

@component.....
  1. modal should have an id like this

<div id="errorModal" class="modal fade bd-example-modal-lg" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel" ..............

  1. then have a method like this

showErrorModal() { $("#errorModal").modal('show'); }

  1. call the method on a button click or anywhere you wish

Differences between cookies and sessions?

A cookie is simply a short text string that is sent back and forth between the client and the server. You could store name=bob; password=asdfas in a cookie and send that back and forth to identify the client on the server side. You could think of this as carrying on an exchange with a bank teller who has no short term memory, and needs you to identify yourself for each and every transaction. Of course using a cookie to store this kind information is horrible insecure. Cookies are also limited in size.

Now, when the bank teller knows about his/her memory problem, He/She can write down your information on a piece of paper and assign you a short id number. Then, instead of giving your account number and driver's license for each transaction, you can just say "I'm client 12"

Translating that to Web Servers: The server will store the pertinent information in the session object, and create a session ID which it will send back to the client in a cookie. When the client sends back the cookie, the server can simply look up the session object using the ID. So, if you delete the cookie, the session will be lost.

One other alternative is for the server to use URL rewriting to exchange the session id.

Suppose you had a link - www.myserver.com/myApp.jsp You could go through the page and rewrite every URL as www.myserver.com/myApp.jsp?sessionID=asdf or even www.myserver.com/asdf/myApp.jsp and exchange the identifier that way. This technique is handled by the web application container and is usually turned on by setting the configuration to use cookieless sessions.

Java Best Practices to Prevent Cross Site Scripting

My preference is to encode all non-alphaumeric characters as HTML numeric character entities. Since almost, if not all attacks require non-alphuneric characters (like <, ", etc) this should eliminate a large chunk of dangerous output.

Format is &#N;, where N is the numeric value of the character (you can just cast the character to an int and concatenate with a string to get a decimal value). For example:

// java-ish pseudocode
StringBuffer safestrbuf = new StringBuffer(string.length()*4);
foreach(char c : string.split() ){  
  if( Character.isAlphaNumeric(c) ) safestrbuf.append(c);
  else safestrbuf.append(""+(int)symbol);

You will also need to be sure that you are encoding immediately before outputting to the browser, to avoid double-encoding, or encoding for HTML but sending to a different location.

How to uninstall jupyter

If you installed Jupiter notebook through anaconda, this may help you:

conda uninstall jupyter notebook

Vector of structs initialization

If you want to use the new current standard, you can do so:

sub.emplace_back ("Math", 70, 0);

or

sub.push_back ({"Math", 70, 0});

These don't require default construction of subject.

Why use Optional.of over Optional.ofNullable?

This depends upon scenarios.

Let's say you have some business functionality and you need to process something with that value further but having null value at time of processing would impact it.

Then, in that case, you can use Optional<?>.

String nullName = null;

String name = Optional.ofNullable(nullName)
                      .map(<doSomething>)
                      .orElse("Default value in case of null");

How do I check if a given string is a legal/valid file name under Windows?

Regular expressions are overkill for this situation. You can use the String.IndexOfAny() method in combination with Path.GetInvalidPathChars() and Path.GetInvalidFileNameChars().

Also note that both Path.GetInvalidXXX() methods clone an internal array and return the clone. So if you're going to be doing this a lot (thousands and thousands of times) you can cache a copy of the invalid chars array for reuse.

Extracting the last n characters from a string in R

I'm not aware of anything in base R, but it's straight-forward to make a function to do this using substr and nchar:

x <- "some text in a string"

substrRight <- function(x, n){
  substr(x, nchar(x)-n+1, nchar(x))
}

substrRight(x, 6)
[1] "string"

substrRight(x, 8)
[1] "a string"

This is vectorised, as @mdsumner points out. Consider:

x <- c("some text in a string", "I really need to learn how to count")
substrRight(x, 6)
[1] "string" " count"

How to set adaptive learning rate for GradientDescentOptimizer?

First of all, tf.train.GradientDescentOptimizer is designed to use a constant learning rate for all variables in all steps. TensorFlow also provides out-of-the-box adaptive optimizers including the tf.train.AdagradOptimizer and the tf.train.AdamOptimizer, and these can be used as drop-in replacements.

However, if you want to control the learning rate with otherwise-vanilla gradient descent, you can take advantage of the fact that the learning_rate argument to the tf.train.GradientDescentOptimizer constructor can be a Tensor object. This allows you to compute a different value for the learning rate in each step, for example:

learning_rate = tf.placeholder(tf.float32, shape=[])
# ...
train_step = tf.train.GradientDescentOptimizer(
    learning_rate=learning_rate).minimize(mse)

sess = tf.Session()

# Feed different values for learning rate to each training step.
sess.run(train_step, feed_dict={learning_rate: 0.1})
sess.run(train_step, feed_dict={learning_rate: 0.1})
sess.run(train_step, feed_dict={learning_rate: 0.01})
sess.run(train_step, feed_dict={learning_rate: 0.01})

Alternatively, you could create a scalar tf.Variable that holds the learning rate, and assign it each time you want to change the learning rate.

Why do I get "a label can only be part of a statement and a declaration is not a statement" if I have a variable that is initialized after a label?

This is a quirk of the C grammar. A label (Cleanup:) is not allowed to appear immediately before a declaration (such as char *str ...;), only before a statement (printf(...);). In C89 this was no great difficulty because declarations could only appear at the very beginning of a block, so you could always move the label down a bit and avoid the issue. In C99 you can mix declarations and code, but you still can't put a label immediately before a declaration.

You can put a semicolon immediately after the label's colon (as suggested by Renan) to make there be an empty statement there; this is what I would do in machine-generated code. Alternatively, hoist the declaration to the top of the function:

int main (void) 
{
    char *str;
    printf("Hello ");
    goto Cleanup;
Cleanup:
    str = "World\n";
    printf("%s\n", str);
    return 0;
}

Regex for password must contain at least eight characters, at least one number and both lower and uppercase letters and special characters

Use the following Regex to satisfy the below conditions:

Conditions: 1] Min 1 special character.
            2] Min 1 number.
            3] Min 8 characters or More

Regex: ^(?=.*\d)(?=.*[#$@!%&*?])[A-Za-z\d#$@!%&*?]{8,}$

Can Test Online: https://regex101.com

Python matplotlib multiple bars

I did this solution: if you want plot more than one plot in one figure, make sure before plotting next plots you have set right matplotlib.pyplot.hold(True) to able adding another plots.

Concerning the datetime values on the X axis, a solution using the alignment of bars works for me. When you create another bar plot with matplotlib.pyplot.bar(), just use align='edge|center' and set width='+|-distance'.

When you set all bars (plots) right, you will see the bars fine.

push multiple elements to array

Now in ECMAScript2015 (a.k.a. ES6), you can use the spread operator to append multiple items at once:

_x000D_
_x000D_
var arr = [1];_x000D_
var newItems = [2, 3];_x000D_
arr.push(...newItems);_x000D_
console.log(arr);
_x000D_
_x000D_
_x000D_

See Kangax's ES6 compatibility table to see what browsers are compatible

Could not transfer artifact org.apache.maven.plugins:maven-surefire-plugin:pom:2.7.1 from/to central (http://repo1.maven.org/maven2)

What helped me were the suggestions by @carlspring (create a settings.xml to configure your http proxy):

<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                              http://maven.apache.org/xsd/settings-1.0.0.xsd">

 <proxies>
    <proxy>
      <id>myproxy</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>user</username>  <!-- Put your username here -->
      <password>pass</password>  <!-- Put your password here -->
      <host>123.45.6.78</host>   <!-- Put the IP address of your proxy server here -->
      <port>80</port>            <!-- Put your proxy server's port number here -->
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts> <!-- Do not use this setting unless you know what you're doing. -->
    </proxy>    
  </proxies> 
</settings>

AND then refreshing eclipse project maven as suggested by @Peter T :

"Force update of Snapshots/Releases" in Eclipse. this clears all errors. So right click on project -> Maven -> update project, then check the above option -> Ok. Hope this helps you.

Indenting code in Sublime text 2?

You can add a shortcut by going to the menu Preferences ? Keybindings ? User, then add there:

{ "keys": ["f12"], "command": "reindent", "args": {"single_line": false} }  

window.location.href doesn't redirect

Though it is very old question, i would like to answer as i faced same issue recently and got solution from here -

http://www.codeproject.com/Questions/727493/JavaScript-document-location-href-not-working Solution:

document.location.href = 'Your url',true;

This worked for me.

Databound drop down list - initial value

Add an item and set its "Selected" property to true, you will probably want to set "appenddatabounditems" property to true also so your initial value isn't deleted when databound.

If you are talking about setting an initial value that is in your databound items then hook into your ondatabound event and set which index you want to selected=true you will want to wrap it in "if not page.isPostBack then ...." though

Protected Sub DepartmentDropDownList_DataBound(ByVal sender As Object, ByVal e As    System.EventArgs) Handles DepartmentDropDownList.DataBound
    If Not Page.IsPostBack Then
        DepartmentDropDownList.SelectedValue = "somevalue"
    End If
End Sub

How do I make an Android EditView 'Done' button and hide the keyboard when clicked?

ActionDone is use when click in next button in the keyboard that time keyboard is hide.Use in Edit Text or AppcompatEdit

XML

1.1 If you use AppCompatEdittext

    <android.support.v7.widget.AppCompatEditText
    android:id="@+id/edittext"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:imeOptions="actionDone"/>

1.2 If you use Edittext

    <EditText
    android:id="@+id/edittext"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:imeOptions="actionDone"/>

JAVA

EditText edittext= (EditText) findViewById(R.id.edittext);
edittext.setImeOptions(EditorInfo.IME_ACTION_DONE);

How to sort by Date with DataTables jquery plugin?

Just in case someone is having trouble where they have blank spaces either in the date values or in cells, you will have to handle those bits. Sometimes an empty space is not handled by trim function coming from html it's like "$nbsp;". If you don't handle these, your sorting will not work properly and will break where ever there is a blank space.

I got this bit of code from jquery extensions here too and changed it a little bit to suit my requirement. You should do the same:) cheers!

function trim(str) {
    str = str.replace(/^\s+/, '');
    for (var i = str.length - 1; i >= 0; i--) {
        if (/\S/.test(str.charAt(i))) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    return str;
}

jQuery.fn.dataTableExt.oSort['uk-date-time-asc'] = function(a, b) {
    if (trim(a) != '' && a!="&nbsp;") {
        if (a.indexOf(' ') == -1) {
            var frDatea = trim(a).split(' ');
            var frDatea2 = frDatea[0].split('/');
            var x = (frDatea2[2] + frDatea2[1] + frDatea2[0]) * 1;
        }
        else {
            var frDatea = trim(a).split(' ');
            var frTimea = frDatea[1].split(':');
            var frDatea2 = frDatea[0].split('/');
            var x = (frDatea2[2] + frDatea2[1] + frDatea2[0] + frTimea[0] + frTimea[1] + frTimea[2]) * 1;
        }
    } else {
        var x = 10000000; // = l'an 1000 ...
    }

    if (trim(b) != '' && b!="&nbsp;") {
        if (b.indexOf(' ') == -1) {
            var frDateb = trim(b).split(' ');
            frDateb = frDateb[0].split('/');
            var y = (frDateb[2] + frDateb[1] + frDateb[0]) * 1;
        }
        else {
            var frDateb = trim(b).split(' ');
            var frTimeb = frDateb[1].split(':');
            frDateb = frDateb[0].split('/');
            var y = (frDateb[2] + frDateb[1] + frDateb[0] + frTimeb[0] + frTimeb[1] + frTimeb[2]) * 1;
        }
    } else {
        var y = 10000000;
    }
    var z = ((x < y) ? -1 : ((x > y) ? 1 : 0));
    return z;
};

jQuery.fn.dataTableExt.oSort['uk-date-time-desc'] = function(a, b) {
    if (trim(a) != '' && a!="&nbsp;") {
        if (a.indexOf(' ') == -1) {
            var frDatea = trim(a).split(' ');
            var frDatea2 = frDatea[0].split('/');
            var x = (frDatea2[2] + frDatea2[1] + frDatea2[0]) * 1;
        }
        else {
            var frDatea = trim(a).split(' ');
            var frTimea = frDatea[1].split(':');
            var frDatea2 = frDatea[0].split('/');
            var x = (frDatea2[2] + frDatea2[1] + frDatea2[0] + frTimea[0] + frTimea[1] + frTimea[2]) * 1;
        }
    } else {
        var x = 10000000;
    }

    if (trim(b) != '' && b!="&nbsp;") {
        if (b.indexOf(' ') == -1) {
            var frDateb = trim(b).split(' ');
            frDateb = frDateb[0].split('/');
            var y = (frDateb[2] + frDateb[1] + frDateb[0]) * 1;
        }
        else {
            var frDateb = trim(b).split(' ');
            var frTimeb = frDateb[1].split(':');
            frDateb = frDateb[0].split('/');
            var y = (frDateb[2] + frDateb[1] + frDateb[0] + frTimeb[0] + frTimeb[1] + frTimeb[2]) * 1;
        }
    } else {
        var y = 10000000;
    }

    var z = ((x < y) ? 1 : ((x > y) ? -1 : 0));
    return z;
};

Is there a concise way to iterate over a stream with indices in Java 8?

If you need the index in the forEach then this provides a way.

  public class IndexedValue {

    private final int    index;
    private final Object value;

    public IndexedValue(final int index, final Object value) { 
        this.index = index;
        this.value = value;
    }

    public int getIndex() {
        return index;
    }

    public Object getValue() {
        return value;
    }
}

Then use it as follows.

@Test
public void withIndex() {
    final List<String> list = Arrays.asList("a", "b");
    IntStream.range(0, list.size())
             .mapToObj(index -> new IndexedValue(index, list.get(index)))
             .forEach(indexValue -> {
                 System.out.println(String.format("%d, %s",
                                                  indexValue.getIndex(),
                                                  indexValue.getValue().toString()));
             });
}

How to add an empty column to a dataframe?

One can use df.insert(index_to_insert_at, column_header, init_value) to insert new column at a specific index.

cost_tbl.insert(1, "col_name", "") 

The above statement would insert an empty Column after the first column.

Test if a command outputs an empty string

Bash Reference Manual

6.4 Bash Conditional Expressions

-z string
     True if the length of string is zero.

-n string
string
     True if the length of string is non-zero.

You can use shorthand version:

if [[ $(ls -A) ]]; then
  echo "there are files"
else
  echo "no files found"
fi

Bad Request, Your browser sent a request that this server could not understand

I got Bad Request, Your browser sent a request that this server could not understand when I tried to download a file to the target machine using curl.
I solved it by instead using scp to copy the file from the source machine to the target machine.

How to validate domain credentials?

Here's how to determine a local user:

    public bool IsLocalUser()
    {
        return windowsIdentity.AuthenticationType == "NTLM";
    }

Edit by Ian Boyd

You should not use NTLM anymore at all. It is so old, and so bad, that Microsoft's Application Verifier (which is used to catch common programming mistakes) will throw a warning if it detects you using NTLM.

Here's a chapter from the Application Verifier documentation about why they have a test if someone is mistakenly using NTLM:

Why the NTLM Plug-in is Needed

NTLM is an outdated authentication protocol with flaws that potentially compromise the security of applications and the operating system. The most important shortcoming is the lack of server authentication, which could allow an attacker to trick users into connecting to a spoofed server. As a corollary of missing server authentication, applications using NTLM can also be vulnerable to a type of attack known as a “reflection” attack. This latter allows an attacker to hijack a user’s authentication conversation to a legitimate server and use it to authenticate the attacker to the user’s computer. NTLM’s vulnerabilities and ways of exploiting them are the target of increasing research activity in the security community.

Although Kerberos has been available for many years many applications are still written to use NTLM only. This needlessly reduces the security of applications. Kerberos cannot however replace NTLM in all scenarios – principally those where a client needs to authenticate to systems that are not joined to a domain (a home network perhaps being the most common of these). The Negotiate security package allows a backwards-compatible compromise that uses Kerberos whenever possible and only reverts to NTLM when there is no other option. Switching code to use Negotiate instead of NTLM will significantly increase the security for our customers while introducing few or no application compatibilities. Negotiate by itself is not a silver bullet – there are cases where an attacker can force downgrade to NTLM but these are significantly more difficult to exploit. However, one immediate improvement is that applications written to use Negotiate correctly are automatically immune to NTLM reflection attacks.

By way of a final word of caution against use of NTLM: in future versions of Windows it will be possible to disable the use of NTLM at the operating system. If applications have a hard dependency on NTLM they will simply fail to authenticate when NTLM is disabled.

How the Plug-in Works

The Verifier plug detects the following errors:

  • The NTLM package is directly specified in the call to AcquireCredentialsHandle (or higher level wrapper API).

  • The target name in the call to InitializeSecurityContext is NULL.

  • The target name in the call to InitializeSecurityContext is not a properly-formed SPN, UPN or NetBIOS-style domain name.

The latter two cases will force Negotiate to fall back to NTLM either directly (the first case) or indirectly (the domain controller will return a “principal not found” error in the second case causing Negotiate to fall back).

The plug-in also logs warnings when it detects downgrades to NTLM; for example, when an SPN is not found by the Domain Controller. These are only logged as warnings since they are often legitimate cases – for example, when authenticating to a system that is not domain-joined.

NTLM Stops

5000 – Application Has Explicitly Selected NTLM Package

Severity – Error

The application or subsystem explicitly selects NTLM instead of Negotiate in the call to AcquireCredentialsHandle. Even though it may be possible for the client and server to authenticate using Kerberos this is prevented by the explicit selection of NTLM.

How to Fix this Error

The fix for this error is to select the Negotiate package in place of NTLM. How this is done will depend on the particular Network subsystem being used by the client or server. Some examples are given below. You should consult the documentation on the particular library or API set that you are using.

APIs(parameter) Used by Application    Incorrect Value  Correct Value  
=====================================  ===============  ========================
AcquireCredentialsHandle (pszPackage)  “NTLM”           NEGOSSP_NAME “Negotiate”

Move layouts up when soft keyboard is shown?

if you are in fragments then you have to add the below code to your onCreate on your activity it solves issue for me

getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN | WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);

Pausing a batch file for amount of time

If choice is available, use this:

choice /C X /T 10 /D X > nul

where /T 10 is the number of seconds to delay. Note the syntax can vary depending on your Windows version, so use CHOICE /? to be sure.

Detect if a jQuery UI dialog box is open

Actually, you have to explicitly compare it to true. If the dialog doesn't exist yet, it will not return false (as you would expect), it will return a DOM object.

if ($('#mydialog').dialog('isOpen') === true) {
    // true
} else {
    // false
}

How do you add multi-line text to a UIButton?

To restate Roger Nolan's suggestion, but with explicit code, this is the general solution:

button.titleLabel?.numberOfLines = 0

Difference between .on('click') vs .click()

.on() is the recommended way to do all your event binding as of jQuery 1.7. It rolls all the functionality of both .bind() and .live() into one function that alters behavior as you pass it different parameters.

As you have written your example, there is no difference between the two. Both bind a handler to the click event of #whatever. on() offers additional flexibility in allowing you to delegate events fired by children of #whatever to a single handler function, if you choose.

// Bind to all links inside #whatever, even new ones created later.
$('#whatever').on('click', 'a', function() { ... });

Selecting distinct values from a JSON

try this, MYJSON will be your json data.

var mytky=[];
mytky=DistinctRecords(MYJSON,"mykeyname");

function DistinctRecords(MYJSON,prop) {
  return MYJSON.filter((obj, pos, arr) => {
    return arr.map(mapObj => mapObj[prop]).indexOf(obj[prop]) === pos;
 })
}

Calling Javascript from a html form

There are a few things to change in your edited version:

  1. You've taken the suggestion of using document.myform['whichThing'] a bit too literally. Your form is named "aye", so the code to access the whichThing radio buttons should use that name: `document.aye['whichThing'].

  2. There's no such thing as an action attribute for the <input> tag. Use onclick instead: <input name="Submit" type="submit" value="Update" onclick="handleClick();return false"/>

  3. Obtaining and cancelling an Event object in a browser is a very involved process. It varies a lot by browser type and version. IE and Firefox handle these things very differently, so a simple event.preventDefault() won't work... in fact, the event variable probably won't even be defined because this is an onclick handler from a tag. This is why Stephen above is trying so hard to suggest a framework. I realize you want to know the mechanics, and I recommend google for that. In this case, as a simple workaround, use return false in the onclick tag as in number 2 above (or return false from the function as stephen suggested).

  4. Because of #3, get rid of everything not the alert statement in your handler.

The code should now look like:

function handleClick()
      {
        alert("Favorite weird creature: "+getRadioButtonValue(document.aye['whichThing']));
      }
    </script>
  </head>
<body>
    <form name="aye">
      <input name="Submit"  type="submit" value="Update" onclick="handleClick();return false"/>
      Which of the following do you like best?
      <p><input type="radio" name="whichThing" value="slithy toves" />Slithy toves</p>
      <p><input type="radio" name="whichThing" value="borogoves" />Borogoves</p>
      <p><input type="radio" name="whichThing" value="mome raths" />Mome raths</p>
    </form>

Servlet for serving static content

Abstract template for a static resource servlet

Partly based on this blog from 2007, here's a modernized and highly reusable abstract template for a servlet which properly deals with caching, ETag, If-None-Match and If-Modified-Since (but no Gzip and Range support; just to keep it simple; Gzip could be done with a filter or via container configuration).

public abstract class StaticResourceServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;
    private static final long ONE_SECOND_IN_MILLIS = TimeUnit.SECONDS.toMillis(1);
    private static final String ETAG_HEADER = "W/\"%s-%s\"";
    private static final String CONTENT_DISPOSITION_HEADER = "inline;filename=\"%1$s\"; filename*=UTF-8''%1$s";

    public static final long DEFAULT_EXPIRE_TIME_IN_MILLIS = TimeUnit.DAYS.toMillis(30);
    public static final int DEFAULT_STREAM_BUFFER_SIZE = 102400;

    @Override
    protected void doHead(HttpServletRequest request, HttpServletResponse response) throws ServletException ,IOException {
        doRequest(request, response, true);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doRequest(request, response, false);
    }

    private void doRequest(HttpServletRequest request, HttpServletResponse response, boolean head) throws IOException {
        response.reset();
        StaticResource resource;

        try {
            resource = getStaticResource(request);
        }
        catch (IllegalArgumentException e) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST);
            return;
        }

        if (resource == null) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        String fileName = URLEncoder.encode(resource.getFileName(), StandardCharsets.UTF_8.name());
        boolean notModified = setCacheHeaders(request, response, fileName, resource.getLastModified());

        if (notModified) {
            response.sendError(HttpServletResponse.SC_NOT_MODIFIED);
            return;
        }

        setContentHeaders(response, fileName, resource.getContentLength());

        if (head) {
            return;
        }

        writeContent(response, resource);
    }

    /**
     * Returns the static resource associated with the given HTTP servlet request. This returns <code>null</code> when
     * the resource does actually not exist. The servlet will then return a HTTP 404 error.
     * @param request The involved HTTP servlet request.
     * @return The static resource associated with the given HTTP servlet request.
     * @throws IllegalArgumentException When the request is mangled in such way that it's not recognizable as a valid
     * static resource request. The servlet will then return a HTTP 400 error.
     */
    protected abstract StaticResource getStaticResource(HttpServletRequest request) throws IllegalArgumentException;

    private boolean setCacheHeaders(HttpServletRequest request, HttpServletResponse response, String fileName, long lastModified) {
        String eTag = String.format(ETAG_HEADER, fileName, lastModified);
        response.setHeader("ETag", eTag);
        response.setDateHeader("Last-Modified", lastModified);
        response.setDateHeader("Expires", System.currentTimeMillis() + DEFAULT_EXPIRE_TIME_IN_MILLIS);
        return notModified(request, eTag, lastModified);
    }

    private boolean notModified(HttpServletRequest request, String eTag, long lastModified) {
        String ifNoneMatch = request.getHeader("If-None-Match");

        if (ifNoneMatch != null) {
            String[] matches = ifNoneMatch.split("\\s*,\\s*");
            Arrays.sort(matches);
            return (Arrays.binarySearch(matches, eTag) > -1 || Arrays.binarySearch(matches, "*") > -1);
        }
        else {
            long ifModifiedSince = request.getDateHeader("If-Modified-Since");
            return (ifModifiedSince + ONE_SECOND_IN_MILLIS > lastModified); // That second is because the header is in seconds, not millis.
        }
    }

    private void setContentHeaders(HttpServletResponse response, String fileName, long contentLength) {
        response.setHeader("Content-Type", getServletContext().getMimeType(fileName));
        response.setHeader("Content-Disposition", String.format(CONTENT_DISPOSITION_HEADER, fileName));

        if (contentLength != -1) {
            response.setHeader("Content-Length", String.valueOf(contentLength));
        }
    }

    private void writeContent(HttpServletResponse response, StaticResource resource) throws IOException {
        try (
            ReadableByteChannel inputChannel = Channels.newChannel(resource.getInputStream());
            WritableByteChannel outputChannel = Channels.newChannel(response.getOutputStream());
        ) {
            ByteBuffer buffer = ByteBuffer.allocateDirect(DEFAULT_STREAM_BUFFER_SIZE);
            long size = 0;

            while (inputChannel.read(buffer) != -1) {
                buffer.flip();
                size += outputChannel.write(buffer);
                buffer.clear();
            }

            if (resource.getContentLength() == -1 && !response.isCommitted()) {
                response.setHeader("Content-Length", String.valueOf(size));
            }
        }
    }

}

Use it together with the below interface representing a static resource.

interface StaticResource {

    /**
     * Returns the file name of the resource. This must be unique across all static resources. If any, the file
     * extension will be used to determine the content type being set. If the container doesn't recognize the
     * extension, then you can always register it as <code>&lt;mime-type&gt;</code> in <code>web.xml</code>.
     * @return The file name of the resource.
     */
    public String getFileName();

    /**
     * Returns the last modified timestamp of the resource in milliseconds.
     * @return The last modified timestamp of the resource in milliseconds.
     */
    public long getLastModified();

    /**
     * Returns the content length of the resource. This returns <code>-1</code> if the content length is unknown.
     * In that case, the container will automatically switch to chunked encoding if the response is already
     * committed after streaming. The file download progress may be unknown.
     * @return The content length of the resource.
     */
    public long getContentLength();

    /**
     * Returns the input stream with the content of the resource. This method will be called only once by the
     * servlet, and only when the resource actually needs to be streamed, so lazy loading is not necessary.
     * @return The input stream with the content of the resource.
     * @throws IOException When something fails at I/O level.
     */
    public InputStream getInputStream() throws IOException;

}

All you need is just extending from the given abstract servlet and implementing the getStaticResource() method according the javadoc.

Concrete example serving from file system:

Here's a concrete example which serves it via an URL like /files/foo.ext from the local disk file system:

@WebServlet("/files/*")
public class FileSystemResourceServlet extends StaticResourceServlet {

    private File folder;

    @Override
    public void init() throws ServletException {
        folder = new File("/path/to/the/folder");
    }

    @Override
    protected StaticResource getStaticResource(HttpServletRequest request) throws IllegalArgumentException {
        String pathInfo = request.getPathInfo();

        if (pathInfo == null || pathInfo.isEmpty() || "/".equals(pathInfo)) {
            throw new IllegalArgumentException();
        }

        String name = URLDecoder.decode(pathInfo.substring(1), StandardCharsets.UTF_8.name());
        final File file = new File(folder, Paths.get(name).getFileName().toString());

        return !file.exists() ? null : new StaticResource() {
            @Override
            public long getLastModified() {
                return file.lastModified();
            }
            @Override
            public InputStream getInputStream() throws IOException {
                return new FileInputStream(file);
            }
            @Override
            public String getFileName() {
                return file.getName();
            }
            @Override
            public long getContentLength() {
                return file.length();
            }
        };
    }

}

Concrete example serving from database:

Here's a concrete example which serves it via an URL like /files/foo.ext from the database via an EJB service call which returns your entity having a byte[] content property:

@WebServlet("/files/*")
public class YourEntityResourceServlet extends StaticResourceServlet {

    @EJB
    private YourEntityService yourEntityService;

    @Override
    protected StaticResource getStaticResource(HttpServletRequest request) throws IllegalArgumentException {
        String pathInfo = request.getPathInfo();

        if (pathInfo == null || pathInfo.isEmpty() || "/".equals(pathInfo)) {
            throw new IllegalArgumentException();
        }

        String name = URLDecoder.decode(pathInfo.substring(1), StandardCharsets.UTF_8.name());
        final YourEntity yourEntity = yourEntityService.getByName(name);

        return (yourEntity == null) ? null : new StaticResource() {
            @Override
            public long getLastModified() {
                return yourEntity.getLastModified();
            }
            @Override
            public InputStream getInputStream() throws IOException {
                return new ByteArrayInputStream(yourEntityService.getContentById(yourEntity.getId()));
            }
            @Override
            public String getFileName() {
                return yourEntity.getName();
            }
            @Override
            public long getContentLength() {
                return yourEntity.getContentLength();
            }
        };
    }

}

Display HTML snippets in HTML

You could try:

_x000D_
_x000D_
Hello! Here is some code:_x000D_
_x000D_
<xmp>_x000D_
<div id="hello">_x000D_
_x000D_
</div>_x000D_
</xmp>
_x000D_
_x000D_
_x000D_

Compiling C++11 with g++

You can check your g++ by command:

which g++
g++ --version

this will tell you which complier is currently it is pointing.

To switch to g++ 4.7 (assuming that you have installed it in your machine),run:

sudo update-alternatives --config gcc

There are 2 choices for the alternative gcc (providing /usr/bin/gcc).

  Selection    Path              Priority   Status
------------------------------------------------------------
  0            /usr/bin/gcc-4.6   60        auto mode
  1            /usr/bin/gcc-4.6   60        manual mode
* 2            /usr/bin/gcc-4.7   40        manual mode

Then select 2 as selection(My machine already pointing to g++ 4.7,so the *)

Once you switch the complier then again run g++ --version to check the switching has happened correctly.

Now compile your program with

g++ -std=c++11 your_file.cpp -o main

Sorting an Array of int using BubbleSort

I use this method for bubble sorting

public static int[] bubbleSort (int[] a) {
    int n = a.length;
    int j = 0;
    boolean swap = true;
    while (swap) {
        swap = false;
        for (int j = 1; j < n; j++) {
            if (a[j-1] > a[j]) {
                j = a[j-1];
                a[j-1] = a[j];
                a[j] = j;
                swap = true;
            }
        }
        n = n - 1;
    }
    return a;
}//end bubbleSort

How to Query an NTP Server using C#?

I know the topic is quite old, but such tools are always handy. I've used the resources above and created a version of NtpClient which allows asynchronously to acquire accurate time, instead of event based.

 /// <summary>
/// Represents a client which can obtain accurate time via NTP protocol.
/// </summary>
public class NtpClient
{
    private readonly TaskCompletionSource<DateTime> _resultCompletionSource;

    /// <summary>
    /// Creates a new instance of <see cref="NtpClient"/> class.
    /// </summary>
    public NtpClient()
    {
        _resultCompletionSource = new TaskCompletionSource<DateTime>();
    }

    /// <summary>
    /// Gets accurate time using the NTP protocol with default timeout of 45 seconds.
    /// </summary>
    /// <returns>Network accurate <see cref="DateTime"/> value.</returns>
    public async Task<DateTime> GetNetworkTimeAsync()
    {
        return await GetNetworkTimeAsync(TimeSpan.FromSeconds(45));
    }

    /// <summary>
    /// Gets accurate time using the NTP protocol with default timeout of 45 seconds.
    /// </summary>
    /// <param name="timeoutMs">Operation timeout in milliseconds.</param>
    /// <returns>Network accurate <see cref="DateTime"/> value.</returns>
    public async Task<DateTime> GetNetworkTimeAsync(int timeoutMs)
    {
        return await GetNetworkTimeAsync(TimeSpan.FromMilliseconds(timeoutMs));
    }

    /// <summary>
    /// Gets accurate time using the NTP protocol with default timeout of 45 seconds.
    /// </summary>
    /// <param name="timeout">Operation timeout.</param>
    /// <returns>Network accurate <see cref="DateTime"/> value.</returns>
    public async Task<DateTime> GetNetworkTimeAsync(TimeSpan timeout)
    {
        using (var socket = new DatagramSocket())
        using (var ct = new CancellationTokenSource(timeout))
        {
            ct.Token.Register(() => _resultCompletionSource.TrySetCanceled());

            socket.MessageReceived += OnSocketMessageReceived;
            //The UDP port number assigned to NTP is 123
            await socket.ConnectAsync(new HostName("pool.ntp.org"), "123");
            using (var writer = new DataWriter(socket.OutputStream))
            {
                // NTP message size is 16 bytes of the digest (RFC 2030)
                var ntpBuffer = new byte[48];

                // Setting the Leap Indicator, 
                // Version Number and Mode values
                // LI = 0 (no warning)
                // VN = 3 (IPv4 only)
                // Mode = 3 (Client Mode)
                ntpBuffer[0] = 0x1B;

                writer.WriteBytes(ntpBuffer);
                await writer.StoreAsync();
                var result = await _resultCompletionSource.Task;
                return result;
            }
        }
    }

    private void OnSocketMessageReceived(DatagramSocket sender, DatagramSocketMessageReceivedEventArgs args)
    {
        try
        {
            using (var reader = args.GetDataReader())
            {
                byte[] response = new byte[48];
                reader.ReadBytes(response);
                _resultCompletionSource.TrySetResult(ParseNetworkTime(response));
            }
        }
        catch (Exception ex)
        {
            _resultCompletionSource.TrySetException(ex);
        }
    }

    private static DateTime ParseNetworkTime(byte[] rawData)
    {
        //Offset to get to the "Transmit Timestamp" field (time at which the reply 
        //departed the server for the client, in 64-bit timestamp format."
        const byte serverReplyTime = 40;

        //Get the seconds part
        ulong intPart = BitConverter.ToUInt32(rawData, serverReplyTime);

        //Get the seconds fraction
        ulong fractPart = BitConverter.ToUInt32(rawData, serverReplyTime + 4);

        //Convert From big-endian to little-endian
        intPart = SwapEndianness(intPart);
        fractPart = SwapEndianness(fractPart);

        var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);

        //**UTC** time
        DateTime networkDateTime = (new DateTime(1900, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds((long)milliseconds);
        return networkDateTime;
    }

    // stackoverflow.com/a/3294698/162671
    private static uint SwapEndianness(ulong x)
    {
        return (uint)(((x & 0x000000ff) << 24) +
                       ((x & 0x0000ff00) << 8) +
                       ((x & 0x00ff0000) >> 8) +
                       ((x & 0xff000000) >> 24));
    }
}

Usage:

var ntp = new NtpClient();
var accurateTime = await ntp.GetNetworkTimeAsync(TimeSpan.FromSeconds(10));

Getting the folder name from a path

It's also important to note that while getting a list of directory names in a loop, the DirectoryInfo class gets initialized once thus allowing only first-time call. In order to bypass this limitation, ensure you use variables within your loop to store any individual directory's name.

For example, this sample code loops through a list of directories within any parent directory while adding each found directory-name inside a List of string type:

[C#]

string[] parentDirectory = Directory.GetDirectories("/yourpath");
List<string> directories = new List<string>();

foreach (var directory in parentDirectory)
{
    // Notice I've created a DirectoryInfo variable.
    DirectoryInfo dirInfo = new DirectoryInfo(directory);

    // And likewise a name variable for storing the name.
    // If this is not added, only the first directory will
    // be captured in the loop; the rest won't.
    string name = dirInfo.Name;

    // Finally we add the directory name to our defined List.
    directories.Add(name);
}

[VB.NET]

Dim parentDirectory() As String = Directory.GetDirectories("/yourpath")
Dim directories As New List(Of String)()

For Each directory In parentDirectory

    ' Notice I've created a DirectoryInfo variable.
    Dim dirInfo As New DirectoryInfo(directory)

    ' And likewise a name variable for storing the name.
    ' If this is not added, only the first directory will
    ' be captured in the loop; the rest won't.
    Dim name As String = dirInfo.Name

    ' Finally we add the directory name to our defined List.
    directories.Add(name)

Next directory

Class JavaLaunchHelper is implemented in two places

This happened to me when I installed Intellij IDEA 2017, go to menu Preferences -> Build, Execution, Deployment -> Debugger and disable the option: "Force Classic VM for JDK 1.3.x and earlier". This works to me.

When should use Readonly and Get only properties

readonly properties are used to create a fail-safe code. i really like the Encapsulation posts series of Mark Seemann about properties and backing fields:

http://blog.ploeh.dk/2011/05/24/PokayokeDesignFromSmellToFragrance.aspx

taken from Mark's example:

public class Fragrance : IFragrance
{
    private readonly string name;

    public Fragrance(string name)
    {
        if (name == null)
        {
            throw new ArgumentNullException("name");
        }

        this.name = name;
    }

    public string Spread()
    {
        return this.name;
    }
}

in this example you use the readonly name field to make sure the class invariant is always valid. in this case the class composer wanted to make sure the name field is set only once (immutable) and is always present.

The number of method references in a .dex file cannot exceed 64k API 17

You have too many methods. There can only be 65536 methods for dex.

As suggested you can use the multidex support.

Just add these lines in the module/build.gradle:

android {

    defaultConfig {
        ...

        // Enabling multidex support.
        multiDexEnabled true
    }
    ...
}

dependencies {
  implementation 'com.android.support:multidex:1.0.3'  //with support libraries
  //implementation 'androidx.multidex:multidex:2.0.1'  //with androidx libraries
}

Also in your Manifest add the MultiDexApplication class from the multidex support library to the application element

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.android.multidex.myapplication">
        <application
            ...
            android:name="android.support.multidex.MultiDexApplication">

            <!-- If you are using androidx use android:name="androidx.multidex.MultiDexApplication" -->

            <!--If you are using your own custom Application class then extend -->
            <!--MultiDexApplication and change above line as-->
            <!--android:name=".YourCustomApplicationClass"> -->

            ...
        </application>
    </manifest>

If you are using your own Application class, change the parent class from Application to MultiDexApplication.
If you can't do it, in your Application class override the attachBaseContext method with:

@Override
protected void attachBaseContext(Context newBase) {
    super.attachBaseContext(newBase);
    MultiDex.install(this);
}

Another solution is to try to remove unused code with ProGuard - Configure the ProGuard settings for your app to run ProGuard and ensure you have shrinking enabled for release builds.

Tab separated values in awk

Use:

awk -v FS='\t' -v OFS='\t' ...

Example from one of my scripts.

I use the FS and OFS variables to manipulate BIND zone files, which are tab delimited:

awk -v FS='\t' -v OFS='\t' \
    -v record_type=$record_type \
    -v hostname=$hostname \
    -v ip_address=$ip_address '
$1==hostname && $3==record_type {$4=ip_address}
{print}
' $zone_file > $temp

This is a clean and easy to read way to do this.

MVC 4 Data Annotations "Display" Attribute

Also internationalization.

I fooled around with this some a while back. Did this in my model:

[Display(Name = "XXX", ResourceType = typeof(Labels))]

I had a separate class library for all the resources, so I had Labels.resx, Labels.culture.resx, etc.

In there I had key = XXX, value = "meaningful string in that culture."