Programs & Examples On #Merb auth

Apache default VirtualHost

The other answers here didn't work for me, but I found a pretty simple solution that did work.

I made the default one the last one listed, and I gave it ServerAlias *.

For example:

NameVirtualHost *:80

<VirtualHost *:80>
    ServerName www.secondwebsite.com
    ServerAlias secondwebsite.com *.secondwebsite.com
    DocumentRoot /home/secondwebsite/web
</VirtualHost>

<VirtualHost *:80>
    ServerName www.defaultwebsite.com
    ServerAlias *
    DocumentRoot /home/defaultwebsite/web
</VirtualHost>

If the visitor didn't explicitly choose to go to something ending in secondwebsite.com, they get the default website.

HashMap get/put complexity

I'm not sure the default hashcode is the address - I read the OpenJDK source for hashcode generation a while ago, and I remember it being something a bit more complicated. Still not something that guarantees a good distribution, perhaps. However, that is to some extent moot, as few classes you'd use as keys in a hashmap use the default hashcode - they supply their own implementations, which ought to be good.

On top of that, what you may not know (again, this is based in reading source - it's not guaranteed) is that HashMap stirs the hash before using it, to mix entropy from throughout the word into the bottom bits, which is where it's needed for all but the hugest hashmaps. That helps deal with hashes that specifically don't do that themselves, although i can't think of any common cases where you'd see that.

Finally, what happens when the table is overloaded is that it degenerates into a set of parallel linked lists - performance becomes O(n). Specifically, the number of links traversed will on average be half the load factor.

Angular - res.json() is not a function

You can remove the entire line below:

 .map((res: Response) => res.json());

No need to use the map method at all.

Relational Database Design Patterns?

Your question is a bit vague, but I suppose UPSERT could be considered a design pattern. For languages that don't implement MERGE, a number of alternatives to solve the problem (if a suitable rows exists, UPDATE; else INSERT) exist.

Run JavaScript code on window close or page refresh?

The documentation here encourages listening to the onbeforeunload event and/or adding an event listener on window.

window.addEventListener('beforeunload', function(event) {
  //do something here
}, false);

You can also just populate the .onunload or .onbeforeunload properties of window with a function or a function reference.

Though behaviour is not standardized across browsers, the function may return a value that the browser will display when confirming whether to leave the page.

iPhone keyboard, Done button and resignFirstResponder

I used this method to change choosing Text Field

- (BOOL)textFieldShouldReturn:(UITextField *)textField {

if ([textField isEqual:self.emailRegisterTextField]) {

    [self.usernameRegisterTextField becomeFirstResponder];

} else if ([textField isEqual:self.usernameRegisterTextField]) {

    [self.passwordRegisterTextField becomeFirstResponder];

} else {

    [textField resignFirstResponder];

    // To click button for registration when you clicking button "Done" on the keyboard
    [self createMyAccount:self.registrationButton];
}

return YES;

}

MVC 4 Data Annotations "Display" Attribute

One of the benefits is you can use it in multiple views and have a consistent label text. It is also used by asp.net MVC scaffolding to generate the labels text and makes it easier to generate meaningful text

[Display(Name = "Wild and Crazy")]
public string WildAndCrazyProperty { get; set; }

"Wild and Crazy" shows up consistently wherever you use the property in your application.

Sometimes this is not flexible as you might want to change the text in some view. In that case, you will have to use custom markup like in your second example

Gridview with two columns and auto resized images

another simple approach with modern built-in stuff like PercentRelativeLayout is now available for new users who hit this problem. thanks to android team for release this item.

<android.support.percent.PercentRelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="true"
app:layout_widthPercent="50%">

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/picture"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="#55000000"
        android:paddingBottom="15dp"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:paddingTop="15dp"
        android:textColor="@android:color/white" />

</FrameLayout>

and for better performance you can use some stuff like picasso image loader which help you to fill whole width of every image parents. for example in your adapter you should use this:

int width= context.getResources().getDisplayMetrics().widthPixels;
    com.squareup.picasso.Picasso
            .with(context)
            .load("some url")
            .centerCrop().resize(width/2,width/2)
            .error(R.drawable.placeholder)
            .placeholder(R.drawable.placeholder)
            .into(item.drawableId);

now you dont need CustomImageView Class anymore.

P.S i recommend to use ImageView in place of Type Int in class Item.

hope this help..

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

You could also disable the cascade delete convention in global scope of your application by doing this:

modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>()
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>()

how to get a list of dates between two dates in java

Get the number of days between dates, inclusive.

public static List<Date> getDaysBetweenDates(Date startdate, Date enddate)
{
    List<Date> dates = new ArrayList<Date>();
    Calendar calendar = new GregorianCalendar();
    calendar.setTime(startdate);

    while (calendar.getTime().before(enddate))
    {
        Date result = calendar.getTime();
        dates.add(result);
        calendar.add(Calendar.DATE, 1);
    }
    return dates;
}

File inside jar is not visible for spring

If your spring-context.xml and my.config files are in different jars then you will need to use classpath*:my.config?

More info here

Also, make sure you are using resource.getInputStream() not resource.getFile() when loading from inside a jar file.

How to count certain elements in array?

Weirdest way I can think of doing this is:

(a.length-(' '+a.join(' ')+' ').split(' '+n+' ').join(' ').match(/ /g).length)+1

Where:

  • a is the array
  • n is the number to count in the array

My suggestion, use a while or for loop ;-)

Rounding a double value to x number of decimal places in swift

I found this wondering if it is possible to correct a user's input. That is if they enter three decimals instead of two for a dollar amount. Say 1.111 instead of 1.11 can you fix it by rounding? The answer for many reasons is no! With money anything over i.e. 0.001 would eventually cause problems in a real checkbook.

Here is a function to check the users input for too many values after the period. But which will allow 1., 1.1 and 1.11.

It is assumed that the value has already been checked for successful conversion from a String to a Double.

//func need to be where transactionAmount.text is in scope

func checkDoublesForOnlyTwoDecimalsOrLess()->Bool{


    var theTransactionCharacterMinusThree: Character = "A"
    var theTransactionCharacterMinusTwo: Character = "A"
    var theTransactionCharacterMinusOne: Character = "A"

    var result = false

    var periodCharacter:Character = "."


    var myCopyString = transactionAmount.text!

    if myCopyString.containsString(".") {

         if( myCopyString.characters.count >= 3){
                        theTransactionCharacterMinusThree = myCopyString[myCopyString.endIndex.advancedBy(-3)]
         }

        if( myCopyString.characters.count >= 2){
            theTransactionCharacterMinusTwo = myCopyString[myCopyString.endIndex.advancedBy(-2)]
        }

        if( myCopyString.characters.count > 1){
            theTransactionCharacterMinusOne = myCopyString[myCopyString.endIndex.advancedBy(-1)]
        }


          if  theTransactionCharacterMinusThree  == periodCharacter {

                            result = true
          }


        if theTransactionCharacterMinusTwo == periodCharacter {

            result = true
        }



        if theTransactionCharacterMinusOne == periodCharacter {

            result = true
        }

    }else {

        //if there is no period and it is a valid double it is good          
        result = true

    }

    return result


}

HTML form action and onsubmit issues

Try:

onsubmit="checkRegistration(event.preventDefault())"

How do I fix a "Performance counter registry hive consistency" when installing SQL Server R2 Express?

I had the perf counter reg issue and here's what I did.

  1. My exe file was SQLManagementStudio_x86_ENU.exe
  2. In command line typed in the below line and hit enter

C:\Projects\Installer\SQL Server 2008 Management Studio\SQLManagementStudio_x86_ENU.exe /ACTION=install /SKIPRULES=PerfMonCounterNotCorruptedCheck

(Note : i had the exe in this location of my machine C:\Projects\Installer\SQL Server 2008 Management Studio)

  1. SQL Server installation started and this time it skipped the rule for Perf counter registry values. The installation was successful.

How to make the webpack dev server run on port 80 and on 0.0.0.0 to make it publicly accessible?

In package.json change the "start" value as follows

Note: Run $sudo npm start, You need to use sudo to run react scripts on port 80

enter image description here

How to atomically delete keys matching a pattern using Redis

I tried most of methods mentioned above but they didn't work for me, after some searches I found these points:

  • if you have more than one db on redis you should determine the database using -n [number]
  • if you have a few keys use del but if there are thousands or millions of keys it's better to use unlink because unlink is non-blocking while del is blocking, for more information visit this page unlink vs del
  • also keys are like del and is blocking

so I used this code to delete keys by pattern:

 redis-cli -n 2 --scan --pattern '[your pattern]' | xargs redis-cli -n 2 unlink 

FAIL - Application at context path /Hello could not be started

Is EmailHandler really the full name of your servlet class, i.e. it's not in a package like com.something.EmailHandler? It has to be fully-qualified in web.xml.

REST - HTTP Post Multipart with JSON

If I understand you correctly, you want to compose a multipart request manually from an HTTP/REST console. The multipart format is simple; a brief introduction can be found in the HTML 4.01 spec. You need to come up with a boundary, which is a string not found in the content, let’s say HereGoes. You set request header Content-Type: multipart/form-data; boundary=HereGoes. Then this should be a valid request body:

--HereGoes
Content-Disposition: form-data; name="myJsonString"
Content-Type: application/json

{"foo": "bar"}
--HereGoes
Content-Disposition: form-data; name="photo"
Content-Type: image/jpeg
Content-Transfer-Encoding: base64

<...JPEG content in base64...>
--HereGoes--

Redirecting a request using servlets and the "setHeader" method not working

Another way of doing this if you want to redirect to any url source after the specified point of time

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.*;

public class MyServlet extends HttpServlet


{

public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException

{

response.setContentType("text/html");

PrintWriter pw=response.getWriter();

pw.println("<b><centre>Redirecting to Google<br>");


response.setHeader("refresh,"5;https://www.google.com/"); // redirects to url  after 5 seconds


pw.close();
}

}

Multiline string literal in C#

I haven't seen this, so I will post it here (if you are interested in passing a string you can do this as well.) The idea is that you can break the string up on multiple lines and add your own content (also on multiple lines) in any way you wish. Here "tableName" can be passed into the string.

    private string createTableQuery = "";

    void createTable(string tableName)
    {

         createTableQuery = @"CREATE TABLE IF NOT EXISTS
                ["+ tableName  + @"] (
               [ID] INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, 
               [Key] NVARCHAR(2048)  NULL, 
               [Value] VARCHAR(2048)  NULL
                                )";
    }

How to filter a RecyclerView with a SearchView

This is my take on expanding @klimat answer to not losing filtering animation.

public void filter(String query){
    int completeListIndex = 0;
    int filteredListIndex = 0;
    while (completeListIndex < completeList.size()){
        Movie item = completeList.get(completeListIndex);
        if(item.getName().toLowerCase().contains(query)){
            if(filteredListIndex < filteredList.size()) {
                Movie filter = filteredList.get(filteredListIndex);
                if (!item.getName().equals(filter.getName())) {
                    filteredList.add(filteredListIndex, item);
                    notifyItemInserted(filteredListIndex);
                }
            }else{
                filteredList.add(filteredListIndex, item);
                notifyItemInserted(filteredListIndex);
            }
            filteredListIndex++;
        }
        else if(filteredListIndex < filteredList.size()){
            Movie filter = filteredList.get(filteredListIndex);
            if (item.getName().equals(filter.getName())) {
                filteredList.remove(filteredListIndex);
                notifyItemRemoved(filteredListIndex);
            }
        }
        completeListIndex++;
    }
}

Basically what it does is looking through a complete list and adding/removing items to a filtered list one by one.

Best algorithm for detecting cycles in a directed graph

Start with a DFS: a cycle exists if and only if a back-edge is discovered during DFS. This is proved as a result of white-path theorum.

CSS table-cell equal width

Here is a working fiddle with indeterminate number of cells: http://jsfiddle.net/r9yrM/1/

You can fix a width to each parent div (the table), otherwise it'll be 100% as usual.

The trick is to use table-layout: fixed; and some width on each cell to trigger it, here 2%. That will trigger the other table algorightm, the one where browsers try very hard to respect the dimensions indicated.
Please test with Chrome (and IE8- if needed). It's OK with a recent Safari but I can't remember the compatibility of this trick with them.

CSS (relevant instructions):

div {
    display: table;
    width: 250px;
    table-layout: fixed;
}

div > div {
    display: table-cell;
    width: 2%; /* or 100% according to OP comment. See edit about Safari 6 below */
}

EDIT (2013): Beware of Safari 6 on OS X, it has table-layout: fixed; wrong (or maybe just different, very different from other browsers. I didn't proof-read CSS2.1 REC table layout ;) ). Be prepared to different results.

Change icon on click (toggle)

Here is a very easy way of doing that

 $(function () {
    $(".glyphicon").unbind('click');
    $(".glyphicon").click(function (e) {
        $(this).toggleClass("glyphicon glyphicon-chevron-up glyphicon glyphicon-chevron-down");
});

Hope this helps :D

How to create a temporary directory?

The following snippet will safely create a temporary directory (-d) and store its name into the TMPDIR. (An example use of TMPDIR variable is shown later in the code where it's used for storing original files that will be possibly modified.)

The first trap line executes exit 1 command when any of the specified signals is received. The second trap line removes (cleans up) the $TMPDIR on program's exit (both normal and abnormal). We initialize these traps after we check that mkdir -d succeeded to avoid accidentally executing the exit trap with $TMPDIR in an unknown state.

#!/bin/bash

# Create a temporary directory and store its name in a variable ...
TMPDIR=$(mktemp -d)

# Bail out if the temp directory wasn't created successfully.
if [ ! -e $TMPDIR ]; then
    >&2 echo "Failed to create temp directory"
    exit 1
fi

# Make sure it gets removed even if the script exits abnormally.
trap "exit 1"           HUP INT PIPE QUIT TERM
trap 'rm -rf "$TMPDIR"' EXIT

# Example use of TMPDIR:
for f in *.csv; do
    cp "$f" "$TMPDIR"
    # remove duplicate lines but keep order
    perl -ne 'print if ++$k{$_}==1' "$TMPDIR/$f" > "$f"
done

How can I convert bigint (UNIX timestamp) to datetime in SQL Server?

This worked for me:

Select
    dateadd(S, [unixtime], '1970-01-01')
From [Table]

In case any one wonders why 1970-01-01, This is called Epoch time.

Below is a quote from Wikipedia:

The number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970,[1][note 1] not counting leap seconds.

How to hide the soft keyboard from inside a fragment?

Use this static method, from anywhere (Activity / Fragment) you like.

public static void hideKeyboard(Activity activity) {
    try{
        InputMethodManager inputManager = (InputMethodManager) activity
                .getSystemService(Context.INPUT_METHOD_SERVICE);
        View currentFocusedView = activity.getCurrentFocus();
        if (currentFocusedView != null) {
            inputManager.hideSoftInputFromWindow(currentFocusedView.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
        }
    }catch (Exception e){
        e.printStackTrace();
    }
}

If you want to use for fragment just call hideKeyboard(((Activity) getActivity())).

What __init__ and self do in Python?

Basically, you need to use the 'self' keyword when using a variable in multiple functions within the same class. As for init, it's used to setup default values incase no other functions from within that class are called.

how to put image in a bundle and pass it to another activity

So you can do it like this, but the limitation with the Parcelables is that the payload between activities has to be less than 1MB total. It's usually better to save the Bitmap to a file and pass the URI to the image to the next activity.

 protected void onCreate(Bundle savedInstanceState) {     setContentView(R.layout.my_layout);     Bitmap bitmap = getIntent().getParcelableExtra("image");     ImageView imageView = (ImageView) findViewById(R.id.imageview);     imageView.setImageBitmap(bitmap);  } 

Div Scrollbar - Any way to style it?

This one does well its scrolling job. It's very easy to understand, just really few lines of code, well written and totally readable.

Getting Lat/Lng from Google marker

You could just call getPosition() on the Marker - have you tried that?

If you're on the deprecated, v2 of the JavaScript API, you can call getLatLng() on GMarker.

NLS_NUMERIC_CHARACTERS setting for decimal

You can see your current session settings by querying nls_session_parameters:

select value
from nls_session_parameters
where parameter = 'NLS_NUMERIC_CHARACTERS';

VALUE                                  
----------------------------------------
.,                                       

That may differ from the database defaults, which you can see in nls_database_parameters.

In this session your query errors:

select to_number('100,12') from dual;

Error report -
SQL Error: ORA-01722: invalid number
01722. 00000 -  "invalid number"

I could alter my session, either directly with alter session or by ensuring my client is configured in a way that leads to the setting the string needs (it may be inherited from a operating system or Java locale, for example):

alter session set NLS_NUMERIC_CHARACTERS = ',.';
select to_number('100,12') from dual;

TO_NUMBER('100,12')
-------------------
             100,12 

In SQL Developer you can set your preferred value in Tool->Preferences->Database->NLS.

But I can also override that session setting as part of the query, with the optional third nlsparam parameter to to_number(); though that makes the optional second fmt parameter necessary as well, so you'd need to be able pick a suitable format:

alter session set NLS_NUMERIC_CHARACTERS = '.,';
select to_number('100,12', '99999D99', 'NLS_NUMERIC_CHARACTERS='',.''')
from dual;

TO_NUMBER('100,12','99999D99','NLS_NUMERIC_CHARACTERS='',.''')
--------------------------------------------------------------
                                                        100.12 

By default the result is still displayed with my session settings, so the decimal separator is still a period.

right align an image using CSS HTML

Float the image right, which will at first cause your text to wrap around it.

Then whatever the very next element is, set it to { clear: right; } and everything will stop wrapping around the image.

I can not find my.cnf on my windows computer

You can find the basedir (and within maybe your my.cnf) if you do the following query in your mysql-Client (e.g. phpmyadmin)

SHOW VARIABLES

What does %~dp0 mean, and how does it work?

%~dp0 expands to current directory path of the running batch file.

To get clear understanding, let's create a batch file in a directory.

C:\script\test.bat

with contents:

@echo off
echo %~dp0

When you run it from command prompt, you will see this result:

C:\script\

Pytorch reshape tensor dimension

This question has been thoroughly answered already, but I want to add for the less experienced python developers that you might find the * operator helpful in conjunction with view().

For example if you have a particular tensor size that you want a different tensor of data to conform to, you might try:

img = Variable(tensor.randn(20,30,3)) # tensor with goal shape
flat_size = 20*30*3
X = Variable(tensor.randn(50, flat_size)) # data tensor

X = X.view(-1, *img.size()) # sweet maneuver
print(X.size()) # size is (50, 20, 30, 3)

This works with numpy shape too:

img = np.random.randn(20,30,3)
flat_size = 20*30*3
X = Variable(tensor.randn(50, flat_size))
X = X.view(-1, *img.shape)
print(X.size()) # size is (50, 20, 30, 3)

Assign a variable inside a Block to a variable outside a Block

yes block are the most used functionality , so in order to avoid the retain cycle we should avoid using the strong variable,including self inside the block, inspite use the _weak or weakself.

How do I create a link to add an entry to a calendar?

Here's an Add to Calendar service to serve the purpose for adding an event on

  1. Apple Calendar
  2. Google Calendar
  3. Outlook
  4. Outlook Online
  5. Yahoo! Calendar

The "Add to Calendar" button for events on websites and calendars is easy to install, language independent, time zone and DST compatible. It works perfectly in all modern browsers, tablets and mobile devices, and with Apple Calendar, Google Calendar, Outlook, Outlook.com and Yahoo Calendar.

<div title="Add to Calendar" class="addeventatc">
    Add to Calendar
    <span class="start">03/01/2018 08:00 AM</span>
    <span class="end">03/01/2018 10:00 AM</span>
    <span class="timezone">America/Los_Angeles</span>
    <span class="title">Summary of the event</span>
    <span class="description">Description of the event</span>
    <span class="location">Location of the event</span>
</div>

enter image description here

Create two blank lines in Markdown

&nbsp;

This HTML entity which means "non-breaking space" will help you for each line break

When to use static classes in C#

I've started using static classes when I wish to use functions, rather than classes, as my unit of reuse. Previously, I was all about the evil of static classes. However, learning F# has made me see them in a new light.

What do I mean by this? Well, say when working up some super DRY code, I end up with a bunch of one-method classes. I may just pull these methods into a static class and then inject them into dependencies using a delegate. This also plays nicely with my dependency injection (DI) container of choice Autofac.

Of course taking a direct dependency on a static method is still usually evil (there are some non-evil uses).

Correct way to quit a Qt program?

QApplication is derived from QCoreApplication and thereby inherits quit() which is a public slot of QCoreApplication, so there is no difference between QApplication::quit() and QCoreApplication::quit().

As we can read in the documentation of QCoreApplication::quit() it "tells the application to exit with return code 0 (success).". If you want to exit because you discovered file corruption then you may not want to exit with return code zero which means success, so you should call QCoreApplication::exit() because you can provide a non-zero returnCode which, by convention, indicates an error.

It is important to note that "if the event loop is not running, this function (QCoreApplication::exit()) does nothing", so in that case you should call exit(EXIT_FAILURE).

Change the Blank Cells to "NA"

While many options above function well, I found coercion of non-target variables to chr problematic. Using ifelse and grepl within lapply resolves this off-target effect (in limited testing). Using slarky's regular expression in grepl:

set.seed(42)
x1 <- sample(c("a","b"," ", "a a", NA), 10, TRUE)
x2 <- sample(c(rnorm(length(x1),0, 1), NA), length(x1), TRUE)

df <- data.frame(x1, x2, stringsAsFactors = FALSE)

The problem of coercion to character class:

df2 <- lapply(df, function(x) gsub("^$|^ $", NA, x))
lapply(df2, class)

$x1 [1] "character"

$x2 [1] "character"

Resolution with use of ifelse:

df3 <- lapply(df, function(x) ifelse(grepl("^$|^ $", x)==TRUE, NA, x))
lapply(df3, class)

$x1 [1] "character"

$x2 [1] "numeric"

How do I calculate power-of in C#?

Do not use Math.Pow

When i use

for (int i = 0; i < 10e7; i++)
{
    var x3 = x * x * x;
    var y3 = y * y * y;
}

It only takes 230 ms whereas the following takes incredible 7050 ms:

for (int i = 0; i < 10e7; i++)
{
    var x3 = Math.Pow(x, 3);
    var y3 = Math.Pow(x, 3);
}

What port number does SOAP use?

SOAP (communication protocol) for communication between applications. Uses HTTP (port 80) or SMTP ( port 25 or 2525 ), for message negotiation and transmission.

C# password TextBox in a ASP.net website

Use the password input type.

<input type="password" name="password" />

Here is a simple demo http://jsfiddle.net/cPaEN/

HTML email in outlook table width issue - content is wider than the specified table width

I guess problem is in width attributes in table and td remove 'px' for example

<table border="0" cellpadding="0" cellspacing="0" width="580px" style="background-color: #0290ba;">

Should be

<table border="0" cellpadding="0" cellspacing="0" width="580" style="background-color: #0290ba;">

rails bundle clean

Just execute, to clean gems obsolete and remove print warningns after bundle.

_x000D_
_x000D_
bundle clean --force
_x000D_
_x000D_
_x000D_

Is there a way to delete all the data from a topic or delete the topic before every run?

Tested with kafka 0.10

1. stop zookeeper & Kafka server,
2. then go to 'kafka-logs' folder , there you will see list of kafka topic folders, delete folder with topic name
3. go to 'zookeeper-data' folder , delete data inside that.
4. start zookeeper & kafka server again.

Note : if you are deleting topic folder/s inside kafka-logs but not from zookeeper-data folder, then you will see topics are still there.

jquery how to catch enter key and change event to tab

Includes all types of inputs

$(':input').keydown(function (e) {
    var key = e.charCode ? e.charCode : e.keyCode ? e.keyCode : 0;
    if (key == 13) {
        e.preventDefault();
        var inputs = $(this).closest('form').find(':input:visible:enabled');
        if ((inputs.length-1) == inputs.index(this))
            $(':input:enabled:visible:first').focus();
        else
            inputs.eq(inputs.index(this) + 1).focus();
    }
});

Pad left or right with string.format (not padleft or padright) with arbitrary string

There is another solution.

Implement IFormatProvider to return a ICustomFormatter that will be passed to string.Format :

public class StringPadder : ICustomFormatter
{
  public string Format(string format, object arg,
       IFormatProvider formatProvider)
  {
     // do padding for string arguments
     // use default for others
  }
}

public class StringPadderFormatProvider : IFormatProvider
{
  public object GetFormat(Type formatType)
  { 
     if (formatType == typeof(ICustomFormatter))
        return new StringPadder();

     return null;
  }
  public static readonly IFormatProvider Default =
     new StringPadderFormatProvider();
}

Then you can use it like this :

string.Format(StringPadderFormatProvider.Default, "->{0:x20}<-", "Hello");

What is the use of rt.jar file in java?

rt.jar contains all of the compiled class files for the base Java Runtime environment. You should not be messing with this jar file.

For MacOS it is called classes.jar and located under /System/Library/Frameworks/<java_version>/Classes . Same not messing with it rule applies there as well :).

http://javahowto.blogspot.com/2006/05/what-does-rtjar-stand-for-in.html

Using OR operator in a jquery if statement

Update: using .indexOf() to detect if stat value is one of arr elements

Pure JavaScript

_x000D_
_x000D_
var arr = [20,30,40,50,60,70,80,90,100];_x000D_
//or detect equal to all_x000D_
//var arr = [10,10,10,10,10,10,10];_x000D_
    var stat = 10;_x000D_
_x000D_
if(arr.indexOf(stat)==-1)alert("stat is not equal to one more elements of array");
_x000D_
_x000D_
_x000D_

Is multiplication and division using shift operators in C actually faster?

Is it actually faster to use say (i<<3)+(i<<1) to multiply with 10 than using i*10 directly?

It might or might not be on your machine - if you care, measure in your real-world usage.

A case study - from 486 to core i7

Benchmarking is very difficult to do meaningfully, but we can look at a few facts. From http://www.penguin.cz/~literakl/intel/s.html#SAL and http://www.penguin.cz/~literakl/intel/i.html#IMUL we get an idea of x86 clock cycles needed for arithmetic shift and multiplication. Say we stick to "486" (the newest one listed), 32 bit registers and immediates, IMUL takes 13-42 cycles and IDIV 44. Each SAL takes 2, and adding 1, so even with a few of those together shifting superficially looks like a winner.

These days, with the core i7:

(from http://software.intel.com/en-us/forums/showthread.php?t=61481)

The latency is 1 cycle for an integer addition and 3 cycles for an integer multiplication. You can find the latencies and thoughput in Appendix C of the "Intel® 64 and IA-32 Architectures Optimization Reference Manual", which is located on http://www.intel.com/products/processor/manuals/.

(from some Intel blurb)

Using SSE, the Core i7 can issue simultaneous add and multiply instructions, resulting in a peak rate of 8 floating-point operations (FLOP) per clock cycle

That gives you an idea of how far things have come. The optimisation trivia - like bit shifting versus * - that was been taken seriously even into the 90s is just obsolete now. Bit-shifting is still faster, but for non-power-of-two mul/div by the time you do all your shifts and add the results it's slower again. Then, more instructions means more cache faults, more potential issues in pipelining, more use of temporary registers may mean more saving and restoring of register content from the stack... it quickly gets too complicated to quantify all the impacts definitively but they're predominantly negative.

functionality in source code vs implementation

More generally, your question is tagged C and C++. As 3rd generation languages, they're specifically designed to hide the details of the underlying CPU instruction set. To satisfy their language Standards, they must support multiplication and shifting operations (and many others) even if the underlying hardware doesn't. In such cases, they must synthesize the required result using many other instructions. Similarly, they must provide software support for floating point operations if the CPU lacks it and there's no FPU. Modern CPUs all support * and <<, so this might seem absurdly theoretical and historical, but the significance thing is that the freedom to choose implementation goes both ways: even if the CPU has an instruction that implements the operation requested in the source code in the general case, the compiler's free to choose something else that it prefers because it's better for the specific case the compiler's faced with.

Examples (with a hypothetical assembly language)

source           literal approach         optimised approach
#define N 0
int x;           .word x                xor registerA, registerA
x *= N;          move x -> registerA
                 move x -> registerB
                 A = B * immediate(0)
                 store registerA -> x
  ...............do something more with x...............

Instructions like exclusive or (xor) have no relationship to the source code, but xor-ing anything with itself clears all the bits, so it can be used to set something to 0. Source code that implies memory addresses may not entail any being used.

These kind of hacks have been used for as long as computers have been around. In the early days of 3GLs, to secure developer uptake the compiler output had to satisfy the existing hardcore hand-optimising assembly-language dev. community that the produced code wasn't slower, more verbose or otherwise worse. Compilers quickly adopted lots of great optimisations - they became a better centralised store of it than any individual assembly language programmer could possibly be, though there's always the chance that they miss a specific optimisation that happens to be crucial in a specific case - humans can sometimes nut it out and grope for something better while compilers just do as they've been told until someone feeds that experience back into them.

So, even if shifting and adding is still faster on some particular hardware, then the compiler writer's likely to have worked out exactly when it's both safe and beneficial.

Maintainability

If your hardware changes you can recompile and it'll look at the target CPU and make another best choice, whereas you're unlikely to ever want to revisit your "optimisations" or list which compilation environments should use multiplication and which should shift. Think of all the non-power-of-two bit-shifted "optimisations" written 10+ years ago that are now slowing down the code they're in as it runs on modern processors...!

Thankfully, good compilers like GCC can typically replace a series of bitshifts and arithmetic with a direct multiplication when any optimisation is enabled (i.e. ...main(...) { return (argc << 4) + (argc << 2) + argc; } -> imull $21, 8(%ebp), %eax) so a recompilation may help even without fixing the code, but that's not guaranteed.

Strange bitshifting code implementing multiplication or division is far less expressive of what you were conceptually trying to achieve, so other developers will be confused by that, and a confused programmer's more likely to introduce bugs or remove something essential in an effort to restore seeming sanity. If you only do non-obvious things when they're really tangibly beneficial, and then document them well (but don't document other stuff that's intuitive anyway), everyone will be happier.

General solutions versus partial solutions

If you have some extra knowledge, such as that your int will really only be storing values x, y and z, then you may be able to work out some instructions that work for those values and get you your result more quickly than when the compiler's doesn't have that insight and needs an implementation that works for all int values. For example, consider your question:

Multiplication and division can be achieved using bit operators...

You illustrate multiplication, but how about division?

int x;
x >> 1;   // divide by 2?

According to the C++ Standard 5.8:

-3- The value of E1 >> E2 is E1 right-shifted E2 bit positions. If E1 has an unsigned type or if E1 has a signed type and a nonnegative value, the value of the result is the integral part of the quotient of E1 divided by the quantity 2 raised to the power E2. If E1 has a signed type and a negative value, the resulting value is implementation-defined.

So, your bit shift has an implementation defined result when x is negative: it may not work the same way on different machines. But, / works far more predictably. (It may not be perfectly consistent either, as different machines may have different representations of negative numbers, and hence different ranges even when there are the same number of bits making up the representation.)

You may say "I don't care... that int is storing the age of the employee, it can never be negative". If you have that kind of special insight, then yes - your >> safe optimisation might be passed over by the compiler unless you explicitly do it in your code. But, it's risky and rarely useful as much of the time you won't have this kind of insight, and other programmers working on the same code won't know that you've bet the house on some unusual expectations of the data you'll be handling... what seems a totally safe change to them might backfire because of your "optimisation".

Is there any sort of input that can't be multiplied or divided in this way?

Yes... as mentioned above, negative numbers have implementation defined behaviour when "divided" by bit-shifting.

Hive query output to file

To directly save the file in HDFS, use the below command:

hive> insert overwrite  directory '/user/cloudera/Sample' row format delimited fields terminated by '\t' stored as textfile select * from table where id >100;

This will put the contents in the folder /user/cloudera/Sample in HDFS.

Rotating x axis labels in R for barplot

EDITED ANSWER PER DAVID'S RESPONSE:

Here's a kind of hackish way. I'm guessing there's an easier way. But you could suppress the bar labels and the plot text of the labels by saving the bar positions from barplot and do a little tweaking up and down. Here's an example with the mtcars data set:

x <- barplot(table(mtcars$cyl), xaxt="n")
labs <- paste(names(table(mtcars$cyl)), "cylinders")
text(cex=1, x=x-.25, y=-1.25, labs, xpd=TRUE, srt=45)

How to send push notification to web browser?

So here I am answering my own question. I have got answers to all my queries from people who have build push notification services in the past.

Update (May 2018): Here is a comprehensive and a very well written doc on web push notification from Google.

Answer to the original questions asked 3 years ago:

  1. Can we use GCM/APNS to send push notification to all Web Browsers including Firefox & Safari?

Answer: Google has deprecated GCM as of April 2018. You can now use Firebase Cloud Messaging (FCM). This supports all platforms including web browsers.

  1. If not via GCM can we have our own back-end to do the same?

Answer: Yes, push notification can be sent from our own back-end. Support for the same has come to all major browsers.

Check this codelab from Google to better understand the implementation.

Some Tutorials:

  • Implementing push notification in Django Here.
  • Using flask to send push notification Here & Here.
  • Sending push notifcaiton from Nodejs Here
  • Sending push notification using php Here & Here
  • Sending push notification from Wordpress. Here & Here
  • Sending push notification from Drupal. Here

Implementing own backend in various programming languages.:

Further Readings: - - Documentation from Firefox website can be read here. - A very good overview of Web Push by Google can be found here. - An FAQ answering most common confusions and questions.

Are there any free services to do the same? There are some companies that provide a similar solution in free, freemium and paid models. Am listing few below:

  1. https://onesignal.com/ (Free | Support all platforms)
  2. https://firebase.google.com/products/cloud-messaging/ (Free)
  3. https://clevertap.com/ (Has free plan)
  4. https://goroost.com/

Note: When choosing a free service remember to read the TOS. Free services often work by collecting user data for various purposes including analytics.

Apart from that, you need to have HTTPS to send push notifications. However, you can get https freely via letsencrypt.org

How to use stringstream to separate comma separated strings

#include <iostream>
#include <sstream>

std::string input = "abc,def,ghi";
std::istringstream ss(input);
std::string token;

while(std::getline(ss, token, ',')) {
    std::cout << token << '\n';
}

abc
def
ghi

How to compare two dates along with time in java

An alternative is Joda-Time.

Use DateTime

DateTime date = new DateTime(new Date());
date.isBeforeNow();
or
date.isAfterNow();

How can I prevent a window from being resized with tkinter?

You can use the minsize and maxsize to set a minimum & maximum size, for example:

def __init__(self,master):
    master.minsize(width=666, height=666)
    master.maxsize(width=666, height=666)

Will give your window a fixed width & height of 666 pixels.

Or, just using minsize

def __init__(self,master):
    master.minsize(width=666, height=666)

Will make sure your window is always at least 666 pixels large, but the user can still expand the window.

Intercept page exit event

Instead of an annoying confirmation popup, it would be nice to delay leaving just a bit (matter of milliseconds) to manage successfully posting the unsaved data to the server, which I managed for my site using writing dummy text to the console like this:

window.onbeforeunload=function(e){
  // only take action (iterate) if my SCHEDULED_REQUEST object contains data        
  for (var key in SCHEDULED_REQUEST){   
    postRequest(SCHEDULED_REQUEST); // post and empty SCHEDULED_REQUEST object
    for (var i=0;i<1000;i++){
      // do something unnoticable but time consuming like writing a lot to console
      console.log('buying some time to finish saving data'); 
    };
    break;
  };
}; // no return string --> user will leave as normal but data is send to server

Edit: See also Synchronous_AJAX and how to do that with jquery

how to determine size of tablespace oracle 11g

The following query can be used to detemine tablespace and other params:

select df.tablespace_name "Tablespace",
       totalusedspace "Used MB",
       (df.totalspace - tu.totalusedspace) "Free MB",
       df.totalspace "Total MB",
       round(100 * ( (df.totalspace - tu.totalusedspace)/ df.totalspace)) "Pct. Free"
  from (select tablespace_name,
               round(sum(bytes) / 1048576) TotalSpace
          from dba_data_files 
         group by tablespace_name) df,
       (select round(sum(bytes)/(1024*1024)) totalusedspace,
               tablespace_name
          from dba_segments 
         group by tablespace_name) tu
 where df.tablespace_name = tu.tablespace_name 
   and df.totalspace <> 0;

Source: https://community.oracle.com/message/1832920

For your case if you want to know the partition name and it's size just run this query:

select owner,
       segment_name,
       partition_name,
       segment_type,
       bytes / 1024/1024 "MB" 
  from dba_segments 
 where owner = <owner_name>;

Java ArrayList clear() function

data.removeAll(data); will do the work, I think.

CSS - Make divs align horizontally

You may put an inner div in the container that is enough wide to hold all the floated divs.

_x000D_
_x000D_
#container {_x000D_
  background-color: red;_x000D_
  overflow: hidden;_x000D_
  width: 200px;_x000D_
}_x000D_
_x000D_
#inner {_x000D_
  overflow: hidden;_x000D_
  width: 2000px;_x000D_
}_x000D_
_x000D_
.child {_x000D_
  float: left;_x000D_
  background-color: blue;_x000D_
  width: 50px;_x000D_
  height: 50px;_x000D_
}
_x000D_
<div id="container">_x000D_
  <div id="inner">_x000D_
    <div class="child"></div>_x000D_
    <div class="child"></div>_x000D_
    <div class="child"></div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How do I parse JSON in Android?

I've coded up a simple example for you and annotated the source. The example shows how to grab live json and parse into a JSONObject for detail extraction:

try{
    // Create a new HTTP Client
    DefaultHttpClient defaultClient = new DefaultHttpClient();
    // Setup the get request
    HttpGet httpGetRequest = new HttpGet("http://example.json");

    // Execute the request in the client
    HttpResponse httpResponse = defaultClient.execute(httpGetRequest);
    // Grab the response
    BufferedReader reader = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent(), "UTF-8"));
    String json = reader.readLine();

    // Instantiate a JSON object from the request response
    JSONObject jsonObject = new JSONObject(json);

} catch(Exception e){
    // In your production code handle any errors and catch the individual exceptions
    e.printStackTrace();
}

Once you have your JSONObject refer to the SDK for details on how to extract the data you require.

The calling thread cannot access this object because a different thread owns it

I kept getting the error when I added cascading comboboxes to my WPF application, and resolved the error by using this API:

    using System.Windows.Data;

    private readonly object _lock = new object();
    private CustomObservableCollection<string> _myUiBoundProperty;
    public CustomObservableCollection<string> MyUiBoundProperty
    {
        get { return _myUiBoundProperty; }
        set
        {
            if (value == _myUiBoundProperty) return;
            _myUiBoundProperty = value;
            NotifyPropertyChanged(nameof(MyUiBoundProperty));
        }
    }

    public MyViewModelCtor(INavigationService navigationService) 
    {
       // Other code...
       BindingOperations.EnableCollectionSynchronization(AvailableDefectSubCategories, _lock );

    }

For details, please see https://msdn.microsoft.com/query/dev14.query?appId=Dev14IDEF1&l=EN-US&k=k(System.Windows.Data.BindingOperations.EnableCollectionSynchronization);k(TargetFrameworkMoniker-.NETFramework,Version%3Dv4.7);k(DevLang-csharp)&rd=true

How to set zoom level in google map

For zooming your map two level then just add this small code of line map.setZoom(map.getZoom() + 2);

Good Linux (Ubuntu) SVN client

See my question:

What is the best subversion client for Linux?

I also agree, GUI clients in linux suck.

I use subeclipse in Eclipse and RapidSVN in gnome.

Do you (really) write exception safe code?

Some of us prefer languages like Java which force us to declare all the exceptions thrown by methods, instead of making them invisible as in C++ and C#.

When done properly, exceptions are superior to error return codes, if for no other reason than you don't have to propagate failures up the call chain manually.

That being said, low-level API library programming should probably avoid exception handling, and stick to error return codes.

It's been my experience that it's difficult to write clean exception handling code in C++. I end up using new(nothrow) a lot.

Android Fatal signal 11 (SIGSEGV) at 0x636f7d89 (code=1). How can it be tracked down?

If you had added some native C code in your project this answer could be helpful.

I had added some native C code in android project.

Now i was trying to access that code which was returning native string to me, before processing the the string i had set its default value as nullptr. Now upon retrieving its value in java code ran into this issue.

As our native C code is out from java directory so getting no clue of exact line of code which is creating the issue. So i would suggest you to check your .cpp file and try to find any clue there.

Hope so you will get rid of the issue soon. :)

VirtualBox: mount.vboxsf: mounting failed with the error: No such device

The solution for me was to update guest additions

(click Devices -> Insert Guest Additions CD image)

What is the most effective way for float and double comparison?

/// testing whether two doubles are almost equal. We consider two doubles
/// equal if the difference is within the range [0, epsilon).
///
/// epsilon: a positive number (supposed to be small)
///
/// if either x or y is 0, then we are comparing the absolute difference to
/// epsilon.
/// if both x and y are non-zero, then we are comparing the relative difference
/// to epsilon.
bool almost_equal(double x, double y, double epsilon)
{
    double diff = x - y;
    if (x != 0 && y != 0){
        diff = diff/y; 
    }

    if (diff < epsilon && -1.0*diff < epsilon){
        return true;
    }
    return false;
}

I used this function for my small project and it works, but note the following:

Double precision error can create a surprise for you. Let's say epsilon = 1.0e-6, then 1.0 and 1.000001 should NOT be considered equal according to the above code, but on my machine the function considers them to be equal, this is because 1.000001 can not be precisely translated to a binary format, it is probably 1.0000009xxx. I test it with 1.0 and 1.0000011 and this time I get the expected result.

Removing leading zeroes from a field in a SQL statement

select substring(ColumnName, patindex('%[^0]%',ColumnName), 10)

TypeError: 'int' object is not callable

As mentioned you might have a variable named round (of type int) in your code and removing that should get rid of the error. For Jupyter notebooks however, simply clearing a cell or deleting it might not take the variable out of scope. In such a case, you can restart your notebook to start afresh after deleting the variable.

ie8 var w= window.open() - "Message: Invalid argument."

I discovered the same problem and after reading the first answer that supposed the problem is caused by the window name, changed it : first to '_blank', which worked fine (both compatibility and regular view), then to the previous value, only minus the space in the value :) - also worked. IMO, the problem (or part of it) is caused by IE being unable to use a normal string value as the wname. Hope this helps if anybody runs into the same problem.

How can I listen for keypress event on the whole page?

Just to add to this in 2019 w Angular 8,

instead of keypress I had to use keydown

@HostListener('document:keypress', ['$event'])

to

@HostListener('document:keydown', ['$event'])

Working Stacklitz

How do I space out the child elements of a StackPanel?

Another nice approach can be seen here: http://blogs.microsoft.co.il/blogs/eladkatz/archive/2011/05/29/what-is-the-easiest-way-to-set-spacing-between-items-in-stackpanel.aspx Link is broken -> this is webarchive of this link.

It shows how to create an attached behavior, so that syntax like this would work:

<StackPanel local:MarginSetter.Margin="5">
   <TextBox Text="hello" />
   <Button Content="hello" />
   <Button Content="hello" />
</StackPanel>

This is the easiest & fastest way to set Margin to several children of a panel, even if they are not of the same type. (I.e. Buttons, TextBoxes, ComboBoxes, etc.)

LDAP filter for blank (empty) attribute

This article http://technet.microsoft.com/en-us/library/ee198810.aspx led me to the solution. The only change is the placement of the exclamation mark.

(!manager=*)

It seems to be working just as wanted.

Refused to display 'url' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'

I was facing this issue in Grafana and all I had to do was go to the config file and change allow_embedding to true and restart the server :)

Android - border for button

Step 1 : Create file named : my_button_bg.xml

Step 2 : Place this file in res/drawables.xml

Step 3 : Insert below code

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
  android:shape="rectangle">
  <gradient android:startColor="#FFFFFF" 
    android:endColor="#00FF00"
    android:angle="270" />
  <corners android:radius="3dp" />
  <stroke android:width="5px" android:color="#000000" />
</shape>

Step 4: Use code "android:background="@drawable/my_button_bg" where needed eg below:

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Your Text"
    android:background="@drawable/my_button_bg"
    />

How do I find the location of Python module sources?

Not all python modules are written in python. Datetime happens to be one of them that is not, and (on linux) is datetime.so.

You would have to download the source code to the python standard library to get at it.

Explicit Return Type of Lambda

You can explicitly specify the return type of a lambda by using -> Type after the arguments list:

[]() -> Type { }

However, if a lambda has one statement and that statement is a return statement (and it returns an expression), the compiler can deduce the return type from the type of that one returned expression. You have multiple statements in your lambda, so it doesn't deduce the type.

Is there a sleep function in JavaScript?

A naive, CPU-intensive method to block execution for a number of milliseconds:

/**
* Delay for a number of milliseconds
*/
function sleep(delay) {
    var start = new Date().getTime();
    while (new Date().getTime() < start + delay);
}

Stash just a single file

Just in case you actually mean 'discard changes' whenever you use 'git stash' (and don't really use git stash to stash it temporarily), in that case you can use

git checkout -- <file>

Note that git stash is just a quicker and simple alternative to branching and doing stuff.

JFrame in full screen Java

Values highlighted that I mean:

JFrame - Properties

Error Code: 1005. Can't create table '...' (errno: 150)

check both tables has same schema InnoDB MyISAM. I made them all the same in my case InnoDB and worked

What's the easiest way to call a function every 5 seconds in jQuery?

Both setInterval and setTimeout can work for you (as @Doug Neiner and @John Boker wrote both now point to setInterval).
See here for some more explanation about both to see which suites you most and how to stop each of them.

RequestDispatcher.forward() vs HttpServletResponse.sendRedirect()

Request Dispatcher is an Interface which is used to dispatch the request or response from web resource to the another web resource. It contains mainly two methods.

  1. request.forward(req,res): This method is used forward the request from one web resource to another resource. i.e from one servlet to another servlet or from one web application to another web appliacation.

  2. response.include(req,res): This method is used include the response of one servlet to another servlet

NOTE: BY using Request Dispatcher we can forward or include the request or responses with in the same server.

request.sendRedirect(): BY using this we can forward or include the request or responses across the different servers. In this the client gets a intimation while redirecting the page but in the above process the client will not get intimation

How to check if the docker engine and a docker container are running?

How I check in SSH.Run:

systemctl

If response: Failed to get D-Bus connection: Operation not permitted

Its a docker or WSL container.

How to use a class from one C# project with another C# project

Paul Ruane is correct, I have just tried myself building the project. I just made a whole SLN to test if it worked.

I made this in VC# VS2008

<< ( Just helping other people that read this aswell with () comments )

Step1:

Make solution called DoubleProject

Step2:

Make Project in solution named DoubleProjectTwo (to do this select the solution file, right click --> Add --> New Project)

I now have two project in the same solution

Step3:

As Paul Ruane stated. go to references in the solution explorer (if closed it's in the view tab of the compiler). DoubleProjectTwo is the one needing functions/methods of DoubleProject so in DoubleProjectTwo right mouse reference there --> Add --> Projects --> DoubleProject.

Step4:

Include the directive for the namespace:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DoubleProject; <------------------------------------------

namespace DoubleProjectTwo
{
    class ClassB
    {
        public string textB = "I am in Class B Project Two";
        ClassA classA = new ClassA();


        public void read()
        {
            textB = classA.read();
        }
    }
}

Step5:

Make something show me proof of results:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace DoubleProject
{
    public class ClassA    //<---------- PUBLIC class
    {
        private const string textA = "I am in Class A Project One";

        public string read()
        {
            return textA;
        }
    }
}

The main

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using DoubleProjectTwo;  //<----- to use ClassB in the main

namespace DoubleProject
{
    class Program
    {
        static void Main(string[] args)
        {
            ClassB foo = new ClassB();

            Console.WriteLine(foo.textB);
            Console.ReadLine();
        }
    }
}

That SHOULD do the trick

Hope this helps

EDIT::: whoops forgot the method call to actually change the string , don't do the same :)

How to compare two maps by their values

Since you asked about ready-made Api's ... well Apache's commons. collections library has a CollectionUtils class that provides easy-to-use methods for Collection manipulation/checking, such as intersection, difference, and union.

Get current batchfile directory

Very simple:

setlocal
cd /d %~dp0
File.exe

manage.py runserver

Just in case any Windows users are having trouble, I thought I'd add my own experience. When running python manage.py runserver 0.0.0.0:8000, I could view urls using localhost:8000, but not my ip address 192.168.1.3:8000.

I ended up disabling ipv6 on my wireless adapter, and running ipconfig /renew. After this everything worked as expected.

How can I reorder my divs using only CSS?

Well, with a bit of absolute positioning and some dodgy margin setting, I can get close, but it's not perfect or pretty:

#wrapper { position: relative; margin-top: 4em; }
#firstDiv { position: absolute; top: 0; width: 100%; }
#secondDiv { position: absolute; bottom: 0; width: 100%; }

The "margin-top: 4em" is the particularly nasty bit: this margin needs to be adjusted according to the amount of content in the firstDiv. Depending on your exact requirements, this might be possible, but I'm hoping anyway that someone might be able to build on this for a solid solution.

Eric's comment about JavaScript should probably be pursued.

Cannot find module cv2 when using OpenCV

For Windows 10 and Python 3.6, this worked for me

pip install opencv-contrib-python

Declaring a variable and setting its value from a SELECT query in Oracle

For storing a single row output into a variable from the select into query :

declare v_username varchare(20); SELECT username into v_username FROM users WHERE user_id = '7';

this will store the value of a single record into the variable v_username.


For storing multiple rows output into a variable from the select into query :

you have to use listagg function. listagg concatenate the resultant rows of a coloumn into a single coloumn and also to differentiate them you can use a special symbol. use the query as below SELECT listagg(username || ',' ) within group (order by username) into v_username FROM users;

What is the difference between 'SAME' and 'VALID' padding in tf.nn.max_pool of tensorflow?

Padding on/off. Determines the effective size of your input.

VALID: No padding. Convolution etc. ops are only performed at locations that are "valid", i.e. not too close to the borders of your tensor.
With a kernel of 3x3 and image of 10x10, you would be performing convolution on the 8x8 area inside the borders.

SAME: Padding is provided. Whenever your operation references a neighborhood (no matter how big), zero values are provided when that neighborhood extends outside the original tensor to allow that operation to work also on border values.
With a kernel of 3x3 and image of 10x10, you would be performing convolution on the full 10x10 area.

How do I convert a calendar week into a date in Excel?

If A1 has the week number and year as a 3 or 4 digit integer in the format wwYY then the formula would be:

=INT(A1/100)*7+DATE(MOD([A1,100),1,1)-WEEKDAY(DATE(MOD(A1,100),1,1))-5

the subtraction of the weekday ensures you return a consistent start day of the week. Use the final subtraction to adjust the start day.

What should I do if the current ASP.NET session is null?

Yes, the Session object might be null, but only in certain circumstances, which you will only rarely run into:

If you only have code in pages, you won't run into this. Most of my ASP .NET code uses Session without checking for null repeatedly. It is, however, something to think about if you are developing an IHttpModule or otherwise is down in the grittier details of ASP .NET.

Edit

In answer to the comment: Whether or not session state is available depends on whether the AcquireRequestState event has run for the request. This is where the session state module does it's work by reading the session cookie and finding the appropiate set of session variables for you.

AcquireRequestState runs before control is handed to your Page. So if you are calling other functionality, including static classes, from your page, you should be fine.

If you have some classes doing initialization logic during startup, for example on the Application_Start event or by using a static constructor, Session state might not be available. It all boils down to whether there is a current request and AcquireRequestState has been run.

Also, should the client have disabled cookies, the Session object will still be available - but on the next request, the user will return with a new empty Session. This is because the client is given a Session statebag if he does not have one already. If the client does not transport the session cookie, we have no way of identifying the client as the same, so he will be handed a new session again and again.

What is the best way to programmatically detect porn images?

I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description ["hard-core pornography"]; and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that.

United States Supreme Court Justice Potter Stewart, 1964

How to enter special characters like "&" in oracle database?

If an escape character is to be added at the beginning or the end like "JAVA", then use:

INSERT INTO STUDENT(name, class_id) VALUES ('Samantha', ''||chr(34)||'JAVA'||chr(34)||'');

codeigniter model error: Undefined property

You have to load the db library first. In autoload.php add :

$autoload['libraries'] = array('database');

Also, try renaming User model class for "User_model".

Delete all lines beginning with a # from a file

I'm a little surprised nobody has suggested the most obvious solution:

grep -v '^#' filename

This solves the problem as stated.

But note that a common convention is for everything from a # to the end of a line to be treated as a comment:

sed 's/#.*$//' filename

though that treats, for example, a # character within a string literal as the beginning of a comment (which may or may not be relevant for your case) (and it leaves empty lines).

A line starting with arbitrary whitespace followed by # might also be treated as a comment:

grep -v '^ *#' filename

if whitespace is only spaces, or

grep -v '^[  ]#' filename

where the two spaces are actually a space followed by a literal tab character (type "control-v tab").

For all these commands, omit the filename argument to read from standard input (e.g., as part of a pipe).

DataGridView.Clear()

dataGridView1.DataSource=null;

Adding Permissions in AndroidManifest.xml in Android Studio?

Go to Android Manifest.xml and be sure to add the <uses-permission tag > inside the manifest tag but Outside of all other tags..

<manifest xlmns:android...>

 <uses-permission android:name="android.permission.INTERNET"></uses-permission>
</manifest>

This is an example of the permission of using Internet.

How to find memory leak in a C++ code/project?

Instructions

Things You'll Need

  • Proficiency in C++
  • C++ compiler
  • Debugger and other investigative software tools

1

Understand the operator basics. The C++ operator new allocates heap memory. The delete operator frees heap memory. For every new, you should use a delete so that you free the same memory you allocated:

char* str = new char [30]; // Allocate 30 bytes to house a string.

delete [] str; // Clear those 30 bytes and make str point nowhere.

2

Reallocate memory only if you've deleted. In the code below, str acquires a new address with the second allocation. The first address is lost irretrievably, and so are the 30 bytes that it pointed to. Now they're impossible to free, and you have a memory leak:

char* str = new char [30]; // Give str a memory address.

// delete [] str; // Remove the first comment marking in this line to correct.

str = new char [60]; /* Give str another memory address with
                                                    the first one gone forever.*/

delete [] str; // This deletes the 60 bytes, not just the first 30.

3

Watch those pointer assignments. Every dynamic variable (allocated memory on the heap) needs to be associated with a pointer. When a dynamic variable becomes disassociated from its pointer(s), it becomes impossible to erase. Again, this results in a memory leak:

char* str1 = new char [30];

char* str2 = new char [40];

strcpy(str1, "Memory leak");

str2 = str1; // Bad! Now the 40 bytes are impossible to free.

delete [] str2; // This deletes the 30 bytes.

delete [] str1; // Possible access violation. What a disaster!

4

Be careful with local pointers. A pointer you declare in a function is allocated on the stack, but the dynamic variable it points to is allocated on the heap. If you don't delete it, it will persist after the program exits from the function:

void Leak(int x){

char* p = new char [x];

// delete [] p; // Remove the first comment marking to correct.

}

5

Pay attention to the square braces after "delete." Use delete by itself to free a single object. Use delete [] with square brackets to free a heap array. Don't do something like this:

char* one = new char;

delete [] one; // Wrong

char* many = new char [30];

delete many; // Wrong!

6

If the leak yet allowed - I'm usually seeking it with deleaker (check it here: http://deleaker.com).

How to figure out the SMTP server host?

generally smtp servers name are smtp.yourdomain.com or mail.yourdomain.com open command prompt try to run following two commands

  1. >ping smtp.yourdomain.com
  2. >ping mail.yourdomain.com

you will most probably get response from any one from the above two commands.and that will be your smtp server

If this doesn't work open your cpanel --> go to your mailing accounts -- > click on configure mail account -- > there somewhere in the page you will get the information about your smtp server

it will be written like this way may be :

Incoming Server:    mail.yourdomain.com
IMAP Port: ---
POP3 Port: ---
Outgoing Server:    mail.yourdomain.com
SMTP Port: ---

How to comment lines in rails html.erb files?

Note that if you want to comment out a single line of printing erb you should do like this

<%#= ["Buck", "Papandreou"].join(" you ") %>

Regular expression for only characters a-z, A-Z

/^[a-zA-Z]+$/ 

Off the top of my head.

Edit:

Or if you don't like the weird looking literal syntax you can do it like this

new RegExp("^[a-zA-Z]+$");

Apache Server (xampp) doesn't run on Windows 10 (Port 80)

I had the same problem on windows 10, IIS/10.0 was using port 80

To solve that:

  • find service "W3SVC"
  • disable it, or set it to "manual"

French name is: "Service de publication World Wide Web"

English name is: "World Wide Web Publishing Service"

german name is: "WWW-Publishingdienst" – thanks @fiffy

Polish name is: "Usluga publikowania w sieci WWW" - thanks @KrzysDan

Russian name is "?????? ???-??????????" – thanks @Kreozot

Italian name is "Servizio Pubblicazione sul Web" – thanks @Claudio-Venturini

Español name is "Servicio de publicación World Wide Web" - thanks @Daniel-Santarriaga

Portuguese (Brazil) name is "Serviço de publicação da World Wide Web" - thanks @thiago-born


Alternatives :


Edit 07 oct 2015: For more details, see Matthew Stumphy's answer Apache Server (xampp) doesn't run on Windows 10 (Port 80)

JUnit tests pass in Eclipse but fail in Maven Surefire

Test execution result different from JUnit run and from maven install seems to be symptom for several problems.

Disabling thread reusing test execution did also get rid of the symptom in our case, but the impression that the code was not thread-safe was still strong.

In our case the difference was due to the presence of a bean that modified the test behaviour. Running just the JUnit test would result fine, but running the project install target would result in a failed test case. Since it was the test case under development, it was immediately suspicious.

It resulted that another test case was instantiating a bean through Spring that would survive until the execution of the new test case. The bean presence was modifying the behaviour of some classes and producing the failed result.

The solution in our case was getting rid of the bean, which was not needed in the first place (yet another prize from the copy+paste gun).

I suggest everybody with this symptom to investigate what the root cause is. Disabling thread reuse in test execution might only hide it.

Creating a List of Lists in C#

or this example, just to make it more visible:

public class CustomerListList : List<CustomerList> { }  

public class CustomerList : List<Customer> { }

public class Customer
{
   public int ID { get; set; }
   public string SomethingWithText { get; set; }
}

and you can keep it going. to the infinity and beyond !

Rename MySQL database

You can do it by RENAME statement for each table in your "current_db" after create the new schema "other_db"

RENAME TABLE current_db.tbl_name TO other_db.tbl_name

Source Rename Table Syntax

Call Class Method From Another Class

You can call a function from within a class with:

A().method1()

What's causing my java.net.SocketException: Connection reset?

I get this error all the time and consider it normal.

It happens when one side tries to read when the other side has already hung up. Thus depending on the protocol this may or may not designate a problem. If my client code specifically indicates to the server that it is going to hang up, then both client and server can hang up at the same time and this message would not happen.

The way I implement my code is for the client to just hang up without saying goodbye. The server can then catch the error and ignore it. In the context of HTTP, I believe one level of the protocol allows more then one request per connection while the other doesn't.

Thus you can see how potentially one side could keep hanging up on the other. I doubt the error you are receiving is of any piratical concern and you could simply catch it to keep it from filling up your log files.

Python read next()

A small change to your algorithm:

filne = "D:/testtube/testdkanimfilternode.txt"
f = open(filne, 'r+')

while 1:
    lines = f.readlines()
    if not lines:
        break
    line_iter= iter(lines) # here
    for line in line_iter: # and here
        print line
        if (line[:5] == "anim "):
            print 'next() '
            ne = line_iter.next() # and here
            print ' ne ',ne,'\n'
            break

f.close()

However, using the pairwise function from itertools recipes:

def pairwise(iterable):
    "s -> (s0,s1), (s1,s2), (s2, s3), ..."
    a, b = itertools.tee(iterable)
    next(b, None)
    return itertools.izip(a, b)

you can change your loop into:

for line, next_line in pairwise(f): # iterate over the file directly
    print line
    if line.startswith("anim "):
        print 'next() '
        print ' ne ', next_line, '\n'
        break

Find a pair of elements from an array whose sum equals a given number

In python

arr = [1, 2, 4, 6, 10]
diff_hash = {}
expected_sum = 3
for i in arr:
    if diff_hash.has_key(i):
        print i, diff_hash[i]
    key = expected_sum - i
    diff_hash[key] = i

What is the best place for storing uploaded images, SQL database or disk file system?

For security reasons, it is also best practise to avoid problems caused by IE's Content Sniffing which can allow attackers to upload JavaScript inside image files, which might get executed in the context of your site. So you might want to transform the images (crop/resize them) somehow before storing them to prevent this sort of attack. This answer has some other ideas.

Python, Pandas : write content of DataFrame into text File

The current best way to do this is to use df.to_string() :

with open(writePath, 'a') as f:
    f.write(
        df.to_string(header = False, index = False)
    )

Will output the following

18 55 1 70   
18 55 2 67 
18 57 2 75     
18 58 1 35  
19 54 2 70 

This method also lets you easily choose which columns to print with the columns attribute, lets you keep the column, index labels if you wish, and has other attributes for spacing ect.

Plot yerr/xerr as shaded region rather than error bars

Ignoring the smooth interpolation between points in your example graph (that would require doing some manual interpolation, or just have a higher resolution of your data), you can use pyplot.fill_between():

from matplotlib import pyplot as plt
import numpy as np

x = np.linspace(0, 30, 30)
y = np.sin(x/6*np.pi)
error = np.random.normal(0.1, 0.02, size=y.shape)
y += np.random.normal(0, 0.1, size=y.shape)

plt.plot(x, y, 'k-')
plt.fill_between(x, y-error, y+error)
plt.show()

enter image description here

See also the matplotlib examples.

What Scala web-frameworks are available?

Prikrutil, I think we're on the same boat. I also come to Scala from Erlang. I like Nitrogen a lot so I decided to created a Scala web framework inspired by it.

Take a look at Xitrum. Its doc is quite extensive. From README:

Xitrum is an async and clustered Scala web framework and web server on top of Netty and Hazelcast:

  • It fills the gap between Scalatra and Lift: more powerful than Scalatra and easier to use than Lift. You can easily create both RESTful APIs and postbacks. Xitrum is controller-first like Scalatra, not view-first like Lift.
  • Annotation is used for URL routes, in the spirit of JAX-RS. You don't have to declare all routes in a single place.
  • Typesafe, in the spirit of Scala.
  • Async, in the spirit of Netty.
  • Sessions can be stored in cookies or clustered Hazelcast.
  • jQuery Validation is integrated for browser side and server side validation. i18n using GNU gettext, which means unlike most other solutions, both singular and plural forms are supported.
  • Conditional GET using ETag.

Hazelcast also gives:

  • In-process and clustered cache, you don't need separate cache servers.
  • In-process and clustered Comet, you can scale Comet to multiple web servers.

Follow the tutorial for a quick start.

Difference between CR LF, LF and CR line break types?

CR and LF are control characters, respectively coded 0x0D (13 decimal) and 0x0A (10 decimal).

They are used to mark a line break in a text file. As you indicated, Windows uses two characters the CR LF sequence; Unix only uses LF and the old MacOS ( pre-OSX MacIntosh) used CR.

An apocryphal historical perspective:

As indicated by Peter, CR = Carriage Return and LF = Line Feed, two expressions have their roots in the old typewriters / TTY. LF moved the paper up (but kept the horizontal position identical) and CR brought back the "carriage" so that the next character typed would be at the leftmost position on the paper (but on the same line). CR+LF was doing both, i.e. preparing to type a new line. As time went by the physical semantics of the codes were not applicable, and as memory and floppy disk space were at a premium, some OS designers decided to only use one of the characters, they just didn't communicate very well with one another ;-)

Most modern text editors and text-oriented applications offer options/settings etc. that allow the automatic detection of the file's end-of-line convention and to display it accordingly.

How to get the selected value from drop down list in jsp?

Direct value should work just fine:

var sel = document.getElementsByName('item');
var sv = sel.value;
alert(sv);

The only reason your code might fail is when there is no item selected, then the selectedIndex returns -1 and the code breaks.

ESRI : Failed to parse source map

Check if you're using some Chrome extension (Night mode or something else). Disable that and see if the 'inject' gone.

How to negate the whole regex?

Assuming you only want to disallow strings that match the regex completely (i.e., mmbla is okay, but mm isn't), this is what you want:

^(?!(?:m{2}|t)$).*$

(?!(?:m{2}|t)$) is a negative lookahead; it says "starting from the current position, the next few characters are not mm or t, followed by the end of the string." The start anchor (^) at the beginning ensures that the lookahead is applied at the beginning of the string. If that succeeds, the .* goes ahead and consumes the string.

FYI, if you're using Java's matches() method, you don't really need the the ^ and the final $, but they don't do any harm. The $ inside the lookahead is required, though.

Warning: mysqli_real_escape_string() expects exactly 2 parameters, 1 given... what I do wrong?

You are mixing mysqli and mysql function.

If your are using mysql function then instead mysqli_real_escape_string($your_variable); use

$username = mysql_real_escape_string($_POST['username']);
$pass = mysql_real_escape_string($_POST['pass']);
$pass1 = mysql_real_escape_string($_POST['pass1']);
$email = mysql_real_escape_string($_POST['email']);

If your using mysqli_* function then you have to include your connection to database into mysqli_real_escape function :

$username = mysqli_real_escape_string($your_connection, $_POST['username']);
$pass = mysqli_real_escape_string($your_connection, $_POST['pass']);
$pass1 = mysqli_real_escape_string($your_connection, $_POST['pass1']);
$email = mysqli_real_escape_string($your_connection, $_POST['email']);

Note : Use mysqli_* function since mysql has been deprecated. For information please read mysqli_*

XAMPP, Apache - Error: Apache shutdown unexpectedly

Ok for my case it was really simple.

I set to a local IP address at my Ethernet port.

Then having this error. Turns out I did not connect the cable to it, so the IP does not resolve to the IP set in Apache.

Solution was to connect the cable to a switch or router. Then able to start Apache.

Android Studio - Device is connected but 'offline'

Download and Install your device driver manually through visiting manufacturer website like :Samsung,micromax,intex etc.

Tensorflow import error: No module named 'tensorflow'

Since none of the above solve my issue, I will post my solution

WARNING: if you just installed TensorFlow using conda, you have to restart your command prompt!

Solution: restart terminal ENTIRELY and restart conda environment

pandas: How do I split text in a column into multiple rows?

This seems a far easier method than those suggested elsewhere in this thread.

split rows in pandas dataframe

T-SQL stored procedure that accepts multiple Id values

Erland Sommarskog has maintained the authoritative answer to this question for the last 16 years: Arrays and Lists in SQL Server.

There are at least a dozen ways to pass an array or list to a query; each has their own unique pros and cons.

I really can't recommend enough to read the article to learn about the tradeoffs among all these options.

How can I obfuscate (protect) JavaScript?

What i would do:

A. Troll the hacker!

This is will be in the second part my fake/obfuscated secret javascript code LAUNCHER. The one you see in the source code.

What does this code?

  1. loads the real code
  2. sets a custom header
  3. posts a custom variable

var ajax=function(a,b,d,c,e,f){
 e=new FormData();
 for(f in d){e.append(f,d[f]);};
 c=new XMLHttpRequest();
 c.open('POST',a);
 c.setRequestHeader("Troll1","lol");
 c.onload=b;
 c.send(e);
};
window.onload=function(){
 ajax('Troll.php',function(){
  (new Function(atob(this.response)))()
 },{'Troll2':'lol'});
}

B. Obfuscate the code a little

What is that?

  1. thats the same code as above in base64
  2. this is not the SECRET javascript code

(new Function(atob('dmFyIGFqYXg9ZnVuY3Rpb24oYSxiLGQsYyxlLGYpe2U9bmV3IEZvcm1EYXRhKCk7Zm9yKGYgaW4gZCl7ZS5hcHBlbmQoZixkW2ZdKTt9O2M9bmV3IFhNTEh0dHBSZXF1ZXN0KCk7Yy5vcGVuKCdQT1NUJyxhKTtjLnNldFJlcXVlc3RIZWFkZXIoIlRyb2xsMSIsImxvbCIpO2Mub25sb2FkPWI7Yy5zZW5kKGUpO307d2luZG93Lm9ubG9hZD1mdW5jdGlvbigpe2FqYXgoJ1Ryb2xsLnBocCcsZnVuY3Rpb24oKXsgKG5ldyBGdW5jdGlvbihhdG9iKHRoaXMucmVzcG9uc2UpKSkoKX0seydUcm9sbDInOidsb2wnfSk7fQ==')))()

C Create a hard to display php file with the real code inside

What does this php code?

  1. Checks for the right referrer (domain/dir/code of your launcher)
  2. Checks for the custom HEADER
  3. Checks for the custom POST variable

If everything is ok it will show you the right code else a fake code or ban ip, close page.. whatever.

<?php
$t1=apache_request_headers();
if(base64_encode($_SERVER['HTTP_REFERER'])=='aHR0cDovL2hlcmUuaXMvbXkvbGF1bmNoZXIuaHRtbA=='&&$_POST['Troll2']=='lol'&&$t1['Troll1']='lol'){
 echo 'ZG9jdW1lbnQuYm9keS5hcHBlbmRDaGlsZChkb2N1bWVudC5jcmVhdGVFbGVtZW50KCdkaXYnKSkuaW5uZXJUZXh0PSdBd2Vzb21lJzsNCg==';//here is the SECRET javascript code
}else{
 echo 'd2luZG93Lm9wZW4oJycsICdfc2VsZicsICcnKTt3aW5kb3cuY2xvc2UoKTs=';
};
?>

base64 referrer = http://here.is/my/launcher.html

SECRET javascript = document.body.appendChild(document.createElement('div')).innerText='Awesome';

FAKE = window.open('', '_self', '');window.close();

Now .. if you define event handlers in the SECRET javascript it's probably accessible.. you need to define them outside with the launchcode and pointing to a nested SECRET function.

SO... is there a easy wayto get the code? document.body.appendChild(document.createElement('div')).innerText='Awesome';

I'm not sure if this works but i'm using chrome and checked Elements,Resources,Network,Sources,Timeline,Profiles,Audits but i didn't find the line above.

note1: if u open the Troll.php url from Inspect element->network in chrome you get the fake code.

note2: the whole code is written for modern browsers. polyfill needs alot more code.

EDIT

launcher.html

<!doctype html><html><head><meta charset="utf-8"><title></title><script src="data:application/javascript;base64,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"></script></head><body></body></html>

Troll.php

<?php $t1=apache_request_headers();if(/*base64_encode($_SERVER['HTTP_REFERER'])=='PUT THE LAUNCHER REFERER HERE'&&*/$_POST['Troll2']=='lol'&&$t1['Troll1']='lol'){echo 'ZG9jdW1lbnQuYm9keS5hcHBlbmRDaGlsZChkb2N1bWVudC5jcmVhdGVFbGVtZW50KCdkaXYnKSkuaW5uZXJUZXh0PSdBd2Vzb21lJzsNCg==';}else{echo 'd2luZG93Lm9wZW4oJycsICdfc2VsZicsICcnKTt3aW5kb3cuY2xvc2UoKTs=';}; ?>

How to solve could not create the virtual machine error of Java Virtual Machine Launcher?

I was facing the same issue while i was using "jdk-10.0.1_windows-x64_bin" and eclipse-jee-oxygen-3a-win32-x86_64 on Windows 64 bit Operating System.

But Finally i resolved this issue by changing my jdk to "jdk-8u172-windows-x64", Now its working fine. @Thanks

Check if a string is a valid Windows directory (folder) path

Call Path.GetFullPath; it will throw exceptions if the path is invalid.

To disallow relative paths (such as Word), call Path.IsPathRooted.

How can I cast int to enum?

Below is a nice utility class for Enums

public static class EnumHelper
{
    public static int[] ToIntArray<T>(T[] value)
    {
        int[] result = new int[value.Length];
        for (int i = 0; i < value.Length; i++)
            result[i] = Convert.ToInt32(value[i]);
        return result;
    }

    public static T[] FromIntArray<T>(int[] value) 
    {
        T[] result = new T[value.Length];
        for (int i = 0; i < value.Length; i++)
            result[i] = (T)Enum.ToObject(typeof(T),value[i]);
        return result;
    }


    internal static T Parse<T>(string value, T defaultValue)
    {
        if (Enum.IsDefined(typeof(T), value))
            return (T) Enum.Parse(typeof (T), value);

        int num;
        if(int.TryParse(value,out num))
        {
            if (Enum.IsDefined(typeof(T), num))
                return (T)Enum.ToObject(typeof(T), num);
        }

        return defaultValue;
    }
}

Get the IP address of the machine

I do not think there is a definitive right answer to your question. Instead there is a big bundle of ways how to get close to what you wish. Hence I will provide some hints how to get it done.

If a machine has more than 2 interfaces (lo counts as one) you will have problems to autodetect the right interface easily. Here are some recipes on how to do it.

The problem, for example, is if hosts are in a DMZ behind a NAT firewall which changes the public IP into some private IP and forwards the requests. Your machine may have 10 interfaces, but only one corresponds to the public one.

Even autodetection does not work in case you are on double-NAT, where your firewall even translates the source-IP into something completely different. So you cannot even be sure, that the default route leads to your interface with a public interface.

Detect it via the default route

This is my recommended way to autodetect things

Something like ip r get 1.1.1.1 usually tells you the interface which has the default route.

If you want to recreate this in your favourite scripting/programming language, use strace ip r get 1.1.1.1 and follow the yellow brick road.

Set it with /etc/hosts

This is my recommendation if you want to stay in control

You can create an entry in /etc/hosts like

80.190.1.3 publicinterfaceip

Then you can use this alias publicinterfaceip to refer to your public interface.

Sadly haproxy does not grok this trick with IPv6

Use the environment

This is a good workaround for /etc/hosts in case you are not root

Same as /etc/hosts. but use the environment for this. You can try /etc/profile or ~/.profile for this.

Hence if your program needs a variable MYPUBLICIP then you can include code like (this is C, feel free to create C++ from it):

#define MYPUBLICIPENVVAR "MYPUBLICIP"

const char *mypublicip = getenv(MYPUBLICIPENVVAR);

if (!mypublicip) { fprintf(stderr, "please set environment variable %s\n", MYPUBLICIPENVVAR); exit(3); }

So you can call your script/program /path/to/your/script like this

MYPUBLICIP=80.190.1.3 /path/to/your/script

this even works in crontab.

Enumerate all interfaces and eliminate those you do not want

The desperate way if you cannot use ip

If you do know what you do not want, you can enumerate all interfaces and ignore all the false ones.

Here already seems to be an answer https://stackoverflow.com/a/265978/490291 for this approach.

Do it like DLNA

The way of the drunken man who tries to drown himself in alcohol

You can try to enumerate all the UPnP gateways on your network and this way find out a proper route for some "external" thing. This even might be on a route where your default route does not point to.

For more on this perhaps see https://en.wikipedia.org/wiki/Internet_Gateway_Device_Protocol

This gives you a good impression which one is your real public interface, even if your default route points elsewhere.

There are even more

Where the mountain meets the prophet

IPv6 routers advertise themselves to give you the right IPv6 prefix. Looking at the prefix gives you a hint about if it has some internal IP or a global one.

You can listen for IGMP or IBGP frames to find out some suitable gateway.

There are less than 2^32 IP addresses. Hence it does not take long on a LAN to just ping them all. This gives you a statistical hint on where the majority of the Internet is located from your point of view. However you should be a bit more sensible than the famous https://de.wikipedia.org/wiki/SQL_Slammer

ICMP and even ARP are good sources for network sideband information. It might help you out as well.

You can use Ethernet Broadcast address to contact to all your network infrastructure devices which often will help out, like DHCP (even DHCPv6) and so on.

This additional list is probably endless and always incomplete, because every manufacturer of network devices is busily inventing new security holes on how to auto-detect their own devices. Which often helps a lot on how to detect some public interface where there shouln't be one.

'Nuff said. Out.

gradlew command not found?

Linux / MacOS

As noted in the comments, just running

./gradlew

worked for me. Adding the ./ tells it to look in the current directory since it isn't in the path.

Windows PowerShell

.\gradlew

PostgreSQL database service

(start -> run -> services.msc) and look for the postgresql-[version] service then right click and enable it

How to preserve insertion order in HashMap?

HashMap is unordered per the second line of the documentation:

This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.

Perhaps you can do as aix suggests and use a LinkedHashMap, or another ordered collection. This link can help you find the most appropriate collection to use.

How to parse unix timestamp to time.Time

I do a lot of logging where the timestamps are float64 and use this function to get the timestamps as string:

func dateFormat(layout string, d float64) string{
    intTime := int64(d)
    t := time.Unix(intTime, 0)
    if layout == "" {
        layout = "2006-01-02 15:04:05"
    }
    return t.Format(layout)
}

How to sort in-place using the merge sort algorithm?

It really isn't easy or efficient, and I suggest you don't do it unless you really have to (and you probably don't have to unless this is homework since the applications of inplace merging are mostly theoretical). Can't you use quicksort instead? Quicksort will be faster anyway with a few simpler optimizations and its extra memory is O(log N).

Anyway, if you must do it then you must. Here's what I found: one and two. I'm not familiar with the inplace merge sort, but it seems like the basic idea is to use rotations to facilitate merging two arrays without using extra memory.

Note that this is slower even than the classic merge sort that's not inplace.

How to make flexbox items the same size?

Set them so that their flex-basis is 0 (so all elements have the same starting point), and allow them to grow:

flex: 1 1 0px

Your IDE or linter might mention that the unit of measure 'px' is redundant. If you leave it out (like: flex: 1 1 0), IE will not render this correctly. So the px is required to support Internet Explorer, as mentioned in the comments by @fabb;

JavaScript and Threads

There's no true threading in JavaScript. JavaScript being the malleable language that it is, does allow you to emulate some of it. Here is an example I came across the other day.

How can I create an utility class?

Making a class abstract sends a message to the readers of your code that you want users of your abstract class to subclass it. However, this is not what you want then to do: a utility class should not be subclassed.

Therefore, adding a private constructor is a better choice here. You should also make the class final to disallow subclassing of your utility class.

How to convert JSON object to an Typescript array?

You have a JSON object that contains an Array. You need to access the array results. Change your code to:

this.data = res.json().results

how to create inline style with :before and :after

The key is to use background-color: inherit; on the pseudo element.
See: http://jsfiddle.net/EdUmc/

How to pause in C?

Is it a console program, running in Windows? If so, run it from a console you've already opened. i.e. run "cmd", then change to your directory that has the .exe in it (using the cd command), then type in the exe name. Your console window will stay open.

How can I make a DateTimePicker display an empty string?

Just set the property as follows:

When the user press "clear button" or "delete key" do

dtpData.CustomFormat = " "  'An empty SPACE
dtpData.Format = DateTimePickerFormat.Custom

On DateTimePicker1_ValueChanged event do

dtpData.CustomFormat = "dd/MM/yyyy hh:mm:ss"

Side-by-side plots with ggplot2

One downside of the solutions based on grid.arrange is that they make it difficult to label the plots with letters (A, B, etc.), as most journals require.

I wrote the cowplot package to solve this (and a few other) issues, specifically the function plot_grid():

library(cowplot)

iris1 <- ggplot(iris, aes(x = Species, y = Sepal.Length)) +
  geom_boxplot() + theme_bw()

iris2 <- ggplot(iris, aes(x = Sepal.Length, fill = Species)) +
  geom_density(alpha = 0.7) + theme_bw() +
  theme(legend.position = c(0.8, 0.8))

plot_grid(iris1, iris2, labels = "AUTO")

enter image description here

The object that plot_grid() returns is another ggplot2 object, and you can save it with ggsave() as usual:

p <- plot_grid(iris1, iris2, labels = "AUTO")
ggsave("plot.pdf", p)

Alternatively, you can use the cowplot function save_plot(), which is a thin wrapper around ggsave() that makes it easy to get the correct dimensions for combined plots, e.g.:

p <- plot_grid(iris1, iris2, labels = "AUTO")
save_plot("plot.pdf", p, ncol = 2)

(The ncol = 2 argument tells save_plot() that there are two plots side-by-side, and save_plot() makes the saved image twice as wide.)

For a more in-depth description of how to arrange plots in a grid see this vignette. There is also a vignette explaining how to make plots with a shared legend.

One frequent point of confusion is that the cowplot package changes the default ggplot2 theme. The package behaves that way because it was originally written for internal lab uses, and we never use the default theme. If this causes problems, you can use one of the following three approaches to work around them:

1. Set the theme manually for every plot. I think it's good practice to always specify a particular theme for each plot, just like I did with + theme_bw() in the example above. If you specify a particular theme, the default theme doesn't matter.

2. Revert the default theme back to the ggplot2 default. You can do this with one line of code:

theme_set(theme_gray())

3. Call cowplot functions without attaching the package. You can also not call library(cowplot) or require(cowplot) and instead call cowplot functions by prepending cowplot::. E.g., the above example using the ggplot2 default theme would become:

## Commented out, we don't call this
# library(cowplot)

iris1 <- ggplot(iris, aes(x = Species, y = Sepal.Length)) +
  geom_boxplot()

iris2 <- ggplot(iris, aes(x = Sepal.Length, fill = Species)) +
  geom_density(alpha = 0.7) +
  theme(legend.position = c(0.8, 0.8))

cowplot::plot_grid(iris1, iris2, labels = "AUTO")

enter image description here

Updates:

  • As of cowplot 1.0, the default ggplot2 theme is not changed anymore.
  • As of ggplot2 3.0.0, plots can be labeled directly, see e.g. here.

How to return value from Action()?

You can use Func<T, TResult> generic delegate. (See MSDN)

Func<MyType, ReturnType> func = (db) => { return new MyType(); }

Also there are useful generic delegates which considers a return value:

  • Converter<TInput, TOutput> (MSDN)
  • Predicate<TInput> - always return bool (MSDN)

Method:

public MyType SimpleUsing.DoUsing<MyType>(Func<TInput, MyType> myTypeFactory)

Generic delegate:

Func<InputArgumentType, MyType> createInstance = db => return new MyType();

Execute:

MyType myTypeInstance = SimpleUsing.DoUsing(
                            createInstance(new InputArgumentType()));

OR explicitly:

MyType myTypeInstance = SimpleUsing.DoUsing(db => return new MyType());

Disable HTTP OPTIONS, TRACE, HEAD, COPY and UNLOCK methods in IIS

Finaly I found another answer for this problem. and this is working for me. Just add below datas to the your webconfig file.

<configuration>
 <system.webServer>
  <security>
   <requestFiltering>
    <verbs allowUnlisted="true">
     <add verb="OPTIONS" allowed="false" />
    </verbs>
   </requestFiltering>
  </security>
 </system.webServer>
</configuration>

Form more information, you can visit this web site: http://www.iis.net/learn/manage/configuring-security/use-request-filtering

if you want to test your web site, is it working or not... You can use "HttpRequester" mozilla firefox plugin. for this plugin: https://addons.mozilla.org/En-us/firefox/addon/httprequester/

jQuery: How to capture the TAB keypress within a Textbox

Working example in jQuery 1.9:

$('body').on('keydown', '#textbox', function(e) {
    if (e.which == 9) {
        e.preventDefault();
        // do your code
    }
});

HTTP Error 404 when running Tomcat from Eclipse

It is because there is no default ROOT web application. When you create some web app and deploy it to Tomcat using Eclipse, then you will be able to access it with the URL in the form of

http://localhost:8080/YourWebAppName

where YourWebAppName is some name you give to your web app (the so called application context path).

Quote from Jetty Documentation Wiki (emphasis mine):

The context path is the prefix of a URL path that is used to select the web application to which an incoming request is routed. Typically a URL in a Java servlet server is of the format http://hostname.com/contextPath/servletPath/pathInfo, where each of the path elements may be zero or more / separated elements. If there is no context path, the context is referred to as the root context.


If you still want the default app which is accessed with the URL of the form

http://localhost:8080

or if you change the default 8080 port to 80, then just

http://localhost

i.e. without application context path read the following (quote from Tutorial: Installing Tomcat 7 and Using it with Eclipse, emphasis mine):

Copy the ROOT (default) Web app into Eclipse. Eclipse forgets to copy the default apps (ROOT, examples, docs, etc.) when it creates a Tomcat folder inside the Eclipse workspace. Go to C:\apache-tomcat-7.0.34\webapps and copy the ROOT folder. Then go to your Eclipse workspace, go to the .metadata folder, and search for "wtpwebapps". You should find something like C:\your-eclipse-workspace-location\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps (or .../tmp1/wtpwebapps if you already had another server registered in Eclipse). Go to the wtpwebapps folder and paste ROOT (say "yes" if asked if you want to merge/replace folders/files). Then reload http://localhost/ to see the Tomcat welcome page.

What are the ways to sum matrix elements in MATLAB?

You are trying to sum up all the elements of 2-D Array

In Matlab use

Array_Sum = sum(sum(Array_Name));

VT-x is disabled in the BIOS for both all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)

If you're on 32-bit machine don't allow more than 3584 MB of RAM and it will run.

CMake not able to find OpenSSL library

Just in case...this works for me. Sorry for specific version of OpenSSL, but might be desirable.

# On macOS, search Homebrew for keg-only versions of OpenSSL
# equivalent of # -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl/ -DOPENSSL_CRYPTO_LIBRARY=/usr/local/opt/openssl/lib/
if (CMAKE_HOST_SYSTEM_NAME MATCHES "Darwin")
    execute_process(
        COMMAND brew --prefix OpenSSL 
        RESULT_VARIABLE BREW_OPENSSL
        OUTPUT_VARIABLE BREW_OPENSSL_PREFIX
        OUTPUT_STRIP_TRAILING_WHITESPACE
    )
    if (BREW_OPENSSL EQUAL 0 AND EXISTS "${BREW_OPENSSL_PREFIX}")
        message(STATUS "Found OpenSSL keg installed by Homebrew at ${BREW_OPENSSL_PREFIX}")
        set(OPENSSL_ROOT_DIR "${BREW_OPENSSL_PREFIX}/")
        set(OPENSSL_INCLUDE_DIR "${BREW_OPENSSL_PREFIX}/include")
        set(OPENSSL_LIBRARIES "${BREW_OPENSSL_PREFIX}/lib")
        set(OPENSSL_CRYPTO_LIBRARY "${BREW_OPENSSL_PREFIX}/lib/libcrypto.dylib")
    endif()
endif()

...

find_package(OpenSSL REQUIRED)
if (OPENSSL_FOUND)
  # Add the include directories for compiling
  target_include_directories(${TARGET_SERVER} PUBLIC ${OPENSSL_INCLUDE_DIR})
  # Add the static lib for linking
  target_link_libraries(${TARGET_SERVER} OpenSSL::SSL OpenSSL::Crypto)
  message(STATUS "Found OpenSSL ${OPENSSL_VERSION}")
else()
  message(STATUS "OpenSSL Not Found")
endif()

What is correct media query for IPad Pro?

Note that there are multiple iPad Pros, each with a different Viewports: When emulating an iPad Pro via the Chrome developer tools, the iPad Pro (12.9") is the default option. If you want to emulate one of the other iPad Pros (10.5" or 9.7") with a different viewport, you'll need to add a custom emulated device with the correct specs.

You can search devices, viewports, and their respective CSS media queries at: http://vizdevices.yesviz.com/devices.php.

For instance, the iPad Pro (12.9") would have the following media queries:

/* Landscape */ 
@media only screen and (min-width: 1366px) and (orientation: landscape) { /* Your Styles... */ }

/*Portrait*/ 
@media only screen and (min-width: 1024px) and (orientation: portrait) { /* Your Styles... */ }

Whereas the iPad Pro (10.5") will have:

/* Landscape */ 
@media only screen and (min-device-width: 1112px) and (orientation: landscape) { /* Your Styles... */ }

/*Portrait*/ 
@media only screen and (min-device-width: 834px) and (orientation: portrait) { /* Your Styles... */ }

What is the most efficient way of finding all the factors of a number in Python?

agf's answer is really quite cool. I wanted to see if I could rewrite it to avoid using reduce(). This is what I came up with:

import itertools
flatten_iter = itertools.chain.from_iterable
def factors(n):
    return set(flatten_iter((i, n//i) 
                for i in range(1, int(n**0.5)+1) if n % i == 0))

I also tried a version that uses tricky generator functions:

def factors(n):
    return set(x for tup in ([i, n//i] 
                for i in range(1, int(n**0.5)+1) if n % i == 0) for x in tup)

I timed it by computing:

start = 10000000
end = start + 40000
for n in range(start, end):
    factors(n)

I ran it once to let Python compile it, then ran it under the time(1) command three times and kept the best time.

  • reduce version: 11.58 seconds
  • itertools version: 11.49 seconds
  • tricky version: 11.12 seconds

Note that the itertools version is building a tuple and passing it to flatten_iter(). If I change the code to build a list instead, it slows down slightly:

  • iterools (list) version: 11.62 seconds

I believe that the tricky generator functions version is the fastest possible in Python. But it's not really much faster than the reduce version, roughly 4% faster based on my measurements.

Autocomplete syntax for HTML or PHP in Notepad++. Not auto-close, autocompelete

Go to:

Settings -> Preferences You will see a dialog box. There click the Backup / Auto-completion tab where you can set the auto complete option :)

Concatenate strings from several rows using Pandas groupby

You can groupby the 'name' and 'month' columns, then call transform which will return data aligned to the original df and apply a lambda where we join the text entries:

In [119]:

df['text'] = df[['name','text','month']].groupby(['name','month'])['text'].transform(lambda x: ','.join(x))
df[['name','text','month']].drop_duplicates()
Out[119]:
    name         text  month
0  name1       hej,du     11
2  name1        aj,oj     12
4  name2     fin,katt     11
6  name2  mycket,lite     12

I sub the original df by passing a list of the columns of interest df[['name','text','month']] here and then call drop_duplicates

EDIT actually I can just call apply and then reset_index:

In [124]:

df.groupby(['name','month'])['text'].apply(lambda x: ','.join(x)).reset_index()

Out[124]:
    name  month         text
0  name1     11       hej,du
1  name1     12        aj,oj
2  name2     11     fin,katt
3  name2     12  mycket,lite

update

the lambda is unnecessary here:

In[38]:
df.groupby(['name','month'])['text'].apply(','.join).reset_index()

Out[38]: 
    name  month         text
0  name1     11           du
1  name1     12        aj,oj
2  name2     11     fin,katt
3  name2     12  mycket,lite

Using LIMIT within GROUP BY to get N results per group?

Try this:

SELECT h.year, h.id, h.rate 
FROM (SELECT h.year, h.id, h.rate, IF(@lastid = (@lastid:=h.id), @index:=@index+1, @index:=0) indx 
      FROM (SELECT h.year, h.id, h.rate 
            FROM h
            WHERE h.year BETWEEN 2000 AND 2009 AND id IN (SELECT rid FROM table2)
            GROUP BY id, h.year
            ORDER BY id, rate DESC
            ) h, (SELECT @lastid:='', @index:=0) AS a
    ) h 
WHERE h.indx <= 5;

Horizontal swipe slider with jQuery and touch devices support?

I would also recommend http://cubiq.org/iscroll-4

BUT if you're not digging on that try this plugin

http://www.zackgrossbart.com/hackito/touchslider/

it works very well and defaults to a horizontal slide bar on desktop -- it's not as elegant on desktop as iscroll-4 is, but it works very well on touch devices

GOOD LUCK!

How to pass an array within a query string?

Here's what I figured out:

Submitting multi-value form fields, i.e. submitting arrays through GET/POST vars, can be done several different ways, as a standard is not necessarily spelled out.

Three possible ways to send multi-value fields or arrays would be:

  • ?cars[]=Saab&cars[]=Audi (Best way- PHP reads this into an array)
  • ?cars=Saab&cars=Audi (Bad way- PHP will only register last value)
  • ?cars=Saab,Audi (Haven't tried this)

Form Examples

On a form, multi-valued fields could take the form of a select box set to multiple:

<form> 
    <select multiple="multiple" name="cars[]"> 
        <option>Volvo</option> 
        <option>Saab</option> 
        <option>Mercedes</option> 
    </select>
</form>

(NOTE: In this case, it would be important to name the select control some_name[], so that the resulting request vars would be registered as an array by PHP)

... or as multiple hidden fields with the same name:

<input type="hidden" name="cars[]" value="Volvo">
<input type="hidden" name="cars[]" value="Saab">
<input type="hidden" name="cars[]" value="Mercedes">

NOTE: Using field[] for multiple values is really poorly documented. I don't see any mention of it in the section on multi-valued keys in Query string - Wikipedia, or in the W3C docs dealing with multi-select inputs.


UPDATE

As commenters have pointed out, this is very much framework-specific. Some examples:

Query string:

?list_a=1&list_a=2&list_a=3&list_b[]=1&list_b[]=2&list_b[]=3&list_c=1,2,3

Rails:

"list_a": "3", 
"list_b":[
    "1",
    "2",
    "3"
  ], 
"list_c": "1,2,3"

Angular:

 "list_a": [
    "1",
    "2",
    "3"
  ],
  "list_b[]": [
    "1",
    "2",
    "3"
  ],
  "list_c": "1,2,3"

(Angular discussion)

See comments for examples in node.js, Wordpress, ASP.net


Maintaining order: One more thing to consider is that if you need to maintain the order of your items (i.e. array as an ordered list), you really only have one option, which is passing a delimited list of values, and explicitly converting it to an array yourself.

Equivalent of "continue" in Ruby

Use next, it will bypass that condition and rest of the code will work. Below i have provided the Full script and out put

class TestBreak
  puts " Enter the nmber"
  no= gets.to_i
  for i in 1..no
    if(i==5)
      next
    else 
      puts i
    end
  end
end

obj=TestBreak.new()

Output: Enter the nmber 10

1 2 3 4 6 7 8 9 10

checking if number entered is a digit in jquery

Forget regular expressions. JavaScript has a builtin function for this: isNaN():

isNaN(123)           // false
isNaN(-1.23)         // false
isNaN(5-2)           // false
isNaN(0)             // false
isNaN("100")         // false
isNaN("Hello")       // true
isNaN("2005/12/12")  // true

Just call it like so:

if (isNaN( $("#whatever").val() )) {
    // It isn't a number
} else {
    // It is a number
}

Adding a color background and border radius to a Layout

background.xml in drawable folder.

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
    <solid android:color="#FFFFFF"/>    
    <stroke
        android:width="3dp"
        android:color="#0FECFF" />

    //specify gradient
    <gradient
        android:startColor="#ffffffff" 
        android:endColor="#110000FF" 
        android:angle="90"/> 

    <padding
        android:left="5dp"
        android:top="5dp"
        android:right="5dp"
        android:bottom="5dp"/> 
    <corners
        android:bottomRightRadius="7dp"
        android:bottomLeftRadius="7dp" 
        android:topLeftRadius="7dp"
        android:topRightRadius="7dp"/> 
</shape>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="210dp"
    android:orientation="vertical"
    android:layout_marginBottom="10dp"        
    android:background="@drawable/background">

Convert MySql DateTime stamp into JavaScript's Date format

Why not do this:

var d = new Date.parseDate( "2000-09-10 00:00:00", 'Y-m-d H:i:s' );

Excel VBA code to copy a specific string to clipboard

Add a reference to the Microsoft Forms 2.0 Object Library and try this code. It only works with text, not with other data types.

Dim DataObj As New MSForms.DataObject

'Put a string in the clipboard
DataObj.SetText "Hello!"
DataObj.PutInClipboard

'Get a string from the clipboard
DataObj.GetFromClipboard
Debug.Print DataObj.GetText

Here you can find more details about how to use the clipboard with VBA.

Assigning default value while creating migration file

I tried t.boolean :active, :default => 1 in migration file for creating entire table. After ran that migration when i checked in db it made as null. Even though i told default as "1". After that slightly i changed migration file like this then it worked for me for setting default value on create table migration file.

t.boolean :active, :null => false,:default =>1. Worked for me.

My Rails framework version is 4.0.0

How to create custom config section in app.config?

Import namespace :

using System.Configuration;

Create ConfigurationElement Company :

public class Company : ConfigurationElement
{

        [ConfigurationProperty("name", IsRequired = true)]
        public string Name
        {
            get
            {
                return this["name"] as string;
            }
        }
            [ConfigurationProperty("code", IsRequired = true)]
        public string Code
        {
            get
            {
                return this["code"] as string;
            }
        }
}

ConfigurationElementCollection:

public class Companies
        : ConfigurationElementCollection
    {
        public Company this[int index]
        {
            get
            {
                return base.BaseGet(index) as Company ;
            }
            set
            {
                if (base.BaseGet(index) != null)
                {
                    base.BaseRemoveAt(index);
                }
                this.BaseAdd(index, value);
            }
        }

       public new Company this[string responseString]
       {
            get { return (Company) BaseGet(responseString); }
            set
            {
                if(BaseGet(responseString) != null)
                {
                    BaseRemoveAt(BaseIndexOf(BaseGet(responseString)));
                }
                BaseAdd(value);
            }
        }

        protected override System.Configuration.ConfigurationElement CreateNewElement()
        {
            return new Company();
        }

        protected override object GetElementKey(System.Configuration.ConfigurationElement element)
        {
            return ((Company)element).Name;
        }
    }

and ConfigurationSection:

public class RegisterCompaniesConfig
        : ConfigurationSection
    {

        public static RegisterCompaniesConfig GetConfig()
        {
            return (RegisterCompaniesConfig)System.Configuration.ConfigurationManager.GetSection("RegisterCompanies") ?? new RegisterCompaniesConfig();
        }

        [System.Configuration.ConfigurationProperty("Companies")]
            [ConfigurationCollection(typeof(Companies), AddItemName = "Company")]
        public Companies Companies
        {
            get
            {
                object o = this["Companies"];
                return o as Companies ;
            }
        }

    }

and you must also register your new configuration section in web.config (app.config):

<configuration>       
    <configSections>
          <section name="Companies" type="blablabla.RegisterCompaniesConfig" ..>

then you load your config with

var config = RegisterCompaniesConfig.GetConfig();
foreach(var item in config.Companies)
{
   do something ..
}

How to convert DateTime to/from specific string format (both ways, e.g. given Format is "yyyyMMdd")?

Based on the property names it looks like you are trying to convert a string to a date by assignment:

claimantAuxillaryRecord.TPOCDate2 = tpoc2[0].ToString();

It is probably due to the current UI culture and therefore it cannot interpret the date string correctly when assigned.

NodeJS accessing file with relative path

Simple! The folder named .. is the parent folder, so you can make the path to the file you need as such

var foobar = require('../config/dev/foobar.json');

If you needed to go up two levels, you would write ../../ etc

Some more details about this in this SO answer and it's comments

Split a String into an array in Swift?

In Swift 4.2 and Xcode 10

//This is your str
let str = "This is my String" //Here replace with your string

Option 1

let items = str.components(separatedBy: " ")//Here replase space with your value and the result is Array.
//Direct single line of code
//let items = "This is my String".components(separatedBy: " ")
let str1 = items[0]
let str2 = items[1]
let str3 = items[2]
let str4 = items[3]
//OutPut
print(items.count)
print(str1)
print(str2)
print(str3)
print(str4)
print(items.first!)
print(items.last!)

Option 2

let items = str.split(separator: " ")
let str1 = String(items.first!)
let str2 = String(items.last!)
//Output
print(items.count)
print(items)
print(str1)
print(str2)

Option 3

let arr = str.split {$0 == " "}
print(arr)

Option 4

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " "))
// Prints "["BLANCHE:", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

By Apple Documentation....

let line = "BLANCHE:   I don't want realism. I want magic!"
print(line.split(separator: " "))
// Prints "["BLANCHE:", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

print(line.split(separator: " ", maxSplits: 1))//This can split your string into 2 parts
// Prints "["BLANCHE:", "  I don\'t want realism. I want magic!"]"

print(line.split(separator: " ", maxSplits: 2))//This can split your string into 3 parts

print(line.split(separator: " ", omittingEmptySubsequences: false))//array contains empty strings where spaces were repeated.
// Prints "["BLANCHE:", "", "", "I", "don\'t", "want", "realism.", "I", "want", "magic!"]"

print(line.split(separator: " ", omittingEmptySubsequences: true))//array not contains empty strings where spaces were repeated.
print(line.split(separator: " ", maxSplits: 4, omittingEmptySubsequences: false))
print(line.split(separator: " ", maxSplits: 3, omittingEmptySubsequences: true))

Radio/checkbox alignment in HTML/CSS

There are several ways to implement it:

  1. For ASP.NET Standard CheckBox:

    .tdInputCheckBox
    { 
    position:relative;
    top:-2px;
    }
    <table>
            <tr>
                <td class="tdInputCheckBox">                  
                    <asp:CheckBox ID="chkMale" runat="server" Text="Male" />
                    <asp:CheckBox ID="chkFemale" runat="server" Text="Female" />
                </td>
            </tr>
    </table>
    
  2. For DevExpress CheckBox:

    <dx:ASPxCheckBox ID="chkAccept" runat="server" Text="Yes" Layout="Flow"/>
    <dx:ASPxCheckBox ID="chkAccept" runat="server" Text="No" Layout="Flow"/>
    
  3. For RadioButtonList:

    <asp:RadioButtonList ID="rdoAccept" runat="server" RepeatDirection="Horizontal">
       <asp:ListItem>Yes</asp:ListItem>
       <asp:ListItem>No</asp:ListItem>
    </asp:RadioButtonList>
    
  4. For Required Field Validators:

    <asp:TextBox ID="txtEmailId" runat="server"></asp:TextBox>
    <asp:RequiredFieldValidator ID="reqEmailId" runat="server" ErrorMessage="Email id is required." Display="Dynamic" ControlToValidate="txtEmailId"></asp:RequiredFieldValidator>
    <asp:RegularExpressionValidator ID="regexEmailId" runat="server" ErrorMessage="Invalid Email Id." ControlToValidate="txtEmailId" Text="*"></asp:RegularExpressionValidator>`
    

How to duplicate a git repository? (without forking)

See https://help.github.com/articles/duplicating-a-repository

Short version:

In order to make an exact duplicate, you need to perform both a bare-clone and a mirror-push:

mkdir foo; cd foo 
# move to a scratch dir

git clone --bare https://github.com/exampleuser/old-repository.git
# Make a bare clone of the repository

cd old-repository.git
git push --mirror https://github.com/exampleuser/new-repository.git
# Mirror-push to the new repository

cd ..
rm -rf old-repository.git  
# Remove our temporary local repository

NOTE: the above will work fine with any remote git repo, the instructions are not specific to github

The above creates a new remote copy of the repo. Then clone it down to your working machine.

How to fire an event when v-model changes?

You should use @input:

<input @input="handleInput" />

@input fires when user changes input value.

@change fires when user changed value and unfocus input (for example clicked somewhere outside)

You can see the difference here: https://jsfiddle.net/posva/oqe9e8pb/

How to split data into 3 sets (train, validation and test)?

Note:

Function was written to handle seeding of randomized set creation. You should not rely on set splitting that doesn't randomize the sets.

import numpy as np
import pandas as pd

def train_validate_test_split(df, train_percent=.6, validate_percent=.2, seed=None):
    np.random.seed(seed)
    perm = np.random.permutation(df.index)
    m = len(df.index)
    train_end = int(train_percent * m)
    validate_end = int(validate_percent * m) + train_end
    train = df.iloc[perm[:train_end]]
    validate = df.iloc[perm[train_end:validate_end]]
    test = df.iloc[perm[validate_end:]]
    return train, validate, test

Demonstration

np.random.seed([3,1415])
df = pd.DataFrame(np.random.rand(10, 5), columns=list('ABCDE'))
df

enter image description here

train, validate, test = train_validate_test_split(df)

train

enter image description here

validate

enter image description here

test

enter image description here

Why do I have to define LD_LIBRARY_PATH with an export every time I run my application?

You should avoid setting LD_LIBRARY_PATH in your .bashrc. See "Why LD_LIBRARY_PATH is bad" for more information.

Use the linker option -rpath while linking so that the dynamic linker knows where to find libsync.so during runtime.

gcc ... -Wl,-rpath /path/to/library -L/path/to/library -lsync -o sync_test

EDIT:

Another way would be to use a wrapper like this

#!/bin/bash

LD_LIBRARY_PATH=/path/to/library sync_test "$@"

If sync_test starts any other programs, they might end up using the libs in /path/to/library which may or may not be intended.

Android widget: How to change the text of a button

I had a button in my layout.xml that was defined as a View as in:

final View myButton = findViewById(R.id.button1);

I was not able to change the text on it until I also defined it as a button:

final View vButton = findViewById(R.id.button1);
final Button bButton = (Button) findViewById(R.id.button1);

When I needed to change the text, I used the bButton.setText("Some Text"); and when I wanted to alter the view, I used the vButton.

Worked great!

When should I use a table variable vs temporary table in sql server?

Your question shows you have succumbed to some of the common misconceptions surrounding table variables and temporary tables.

I have written quite an extensive answer on the DBA site looking at the differences between the two object types. This also addresses your question about disk vs memory (I didn't see any significant difference in behaviour between the two).

Regarding the question in the title though as to when to use a table variable vs a local temporary table you don't always have a choice. In functions, for example, it is only possible to use a table variable and if you need to write to the table in a child scope then only a #temp table will do (table-valued parameters allow readonly access).

Where you do have a choice some suggestions are below (though the most reliable method is to simply test both with your specific workload).

  1. If you need an index that cannot be created on a table variable then you will of course need a #temporary table. The details of this are version dependant however. For SQL Server 2012 and below the only indexes that could be created on table variables were those implicitly created through a UNIQUE or PRIMARY KEY constraint. SQL Server 2014 introduced inline index syntax for a subset of the options available in CREATE INDEX. This has been extended since to allow filtered index conditions. Indexes with INCLUDE-d columns or columnstore indexes are still not possible to create on table variables however.

  2. If you will be repeatedly adding and deleting large numbers of rows from the table then use a #temporary table. That supports TRUNCATE (which is more efficient than DELETE for large tables) and additionally subsequent inserts following a TRUNCATE can have better performance than those following a DELETE as illustrated here.

  3. If you will be deleting or updating a large number of rows then the temp table may well perform much better than a table variable - if it is able to use rowset sharing (see "Effects of rowset sharing" below for an example).
  4. If the optimal plan using the table will vary dependent on data then use a #temporary table. That supports creation of statistics which allows the plan to be dynamically recompiled according to the data (though for cached temporary tables in stored procedures the recompilation behaviour needs to be understood separately).
  5. If the optimal plan for the query using the table is unlikely to ever change then you may consider a table variable to skip the overhead of statistics creation and recompiles (would possibly require hints to fix the plan you want).
  6. If the source for the data inserted to the table is from a potentially expensive SELECT statement then consider that using a table variable will block the possibility of this using a parallel plan.
  7. If you need the data in the table to survive a rollback of an outer user transaction then use a table variable. A possible use case for this might be logging the progress of different steps in a long SQL batch.
  8. When using a #temp table within a user transaction locks can be held longer than for table variables (potentially until the end of transaction vs end of statement dependent on the type of lock and isolation level) and also it can prevent truncation of the tempdb transaction log until the user transaction ends. So this might favour the use of table variables.
  9. Within stored routines, both table variables and temporary tables can be cached. The metadata maintenance for cached table variables is less than that for #temporary tables. Bob Ward points out in his tempdb presentation that this can cause additional contention on system tables under conditions of high concurrency. Additionally, when dealing with small quantities of data this can make a measurable difference to performance.

Effects of rowset sharing

DECLARE @T TABLE(id INT PRIMARY KEY, Flag BIT);

CREATE TABLE #T (id INT PRIMARY KEY, Flag BIT);

INSERT INTO @T 
output inserted.* into #T
SELECT TOP 1000000 ROW_NUMBER() OVER (ORDER BY @@SPID), 0
FROM master..spt_values v1, master..spt_values v2

SET STATISTICS TIME ON

/*CPU time = 7016 ms,  elapsed time = 7860 ms.*/
UPDATE @T SET Flag=1;

/*CPU time = 6234 ms,  elapsed time = 7236 ms.*/
DELETE FROM @T

/* CPU time = 828 ms,  elapsed time = 1120 ms.*/
UPDATE #T SET Flag=1;

/*CPU time = 672 ms,  elapsed time = 980 ms.*/
DELETE FROM #T

DROP TABLE #T

PHP combine two associative arrays into one array

There is also array_replace, where an original array is modified by other arrays preserving the key => value association without creating duplicate keys.

  • Same keys on other arrays will cause values to overwrite the original array
  • New keys on other arrays will be created on the original array

"while :" vs. "while true"

from manual:

: [arguments] No effect; the command does nothing beyond expanding arguments and performing any specified redirections. A zero exit code is returned.

As this returns always zero therefore is is similar to be used as true

Check out this answer: What Is the Purpose of the `:' (colon) GNU Bash Builtin?

How do I call a dynamically-named method in Javascript?

Try These

Call Functions With Dynamic Names, like this:

let dynamic_func_name = 'alert';
(new Function(dynamic_func_name+'()'))()

with parameters:

let dynamic_func_name = 'alert';
let para_1 = 'HAHAHA';
let para_2 = 'ABCD';
(new Function(`${dynamic_func_name}('${para_1}','${para_2}')`))()

Run Dynamic Code:

let some_code = "alert('hahaha');";
(new Function(some_code))()

Difference between SET autocommit=1 and START TRANSACTION in mysql (Have I missed something?)

In InnoDB you have START TRANSACTION;, which in this engine is the officialy recommended way to do transactions, instead of SET AUTOCOMMIT = 0; (don't use SET AUTOCOMMIT = 0; for transactions in InnoDB unless it is for optimizing read only transactions). Commit with COMMIT;.

You might want to use SET AUTOCOMMIT = 0; in InnoDB for testing purposes, and not precisely for transactions.

In MyISAM you do not have START TRANSACTION;. In this engine, use SET AUTOCOMMIT = 0; for transactions. Commit with COMMIT; or SET AUTOCOMMIT = 1; (Difference explained in MyISAM example commentary below). You can do transactions this way in InnoDB too.

Source: http://dev.mysql.com/doc/refman/5.6/en/glossary.html#glos_autocommit

Examples of general use transactions:

/* InnoDB */
START TRANSACTION;

INSERT INTO table_name (table_field) VALUES ('foo');
INSERT INTO table_name (table_field) VALUES ('bar');

COMMIT; /* SET AUTOCOMMIT = 1 might not set AUTOCOMMIT to its previous state */

/* MyISAM */
SET AUTOCOMMIT = 0;

INSERT INTO table_name (table_field) VALUES ('foo');
INSERT INTO table_name (table_field) VALUES ('bar');

SET AUTOCOMMIT = 1; /* COMMIT statement instead would not restore AUTOCOMMIT to 1 */

Find the index of a dict within a list, by matching the dict's value

Answer offered by @faham is a nice one-liner, but it doesn't return the index to the dictionary containing the value. Instead it returns the dictionary itself. Here is a simple way to get: A list of indexes one or more if there are more than one, or an empty list if there are none:

list = [{'id':'1234','name':'Jason'},
        {'id':'2345','name':'Tom'},
        {'id':'3456','name':'Art'}]

[i for i, d in enumerate(list) if 'Tom' in d.values()]

Output:

>>> [1]

What I like about this approach is that with a simple edit you can get a list of both the indexes and the dictionaries as tuples. This is the problem I needed to solve and found these answers. In the following, I added a duplicate value in a different dictionary to show how it works:

list = [{'id':'1234','name':'Jason'},
        {'id':'2345','name':'Tom'},
        {'id':'3456','name':'Art'},
        {'id':'4567','name':'Tom'}]

[(i, d) for i, d in enumerate(list) if 'Tom' in d.values()]

Output:

>>> [(1, {'id': '2345', 'name': 'Tom'}), (3, {'id': '4567', 'name': 'Tom'})]

This solution finds all dictionaries containing 'Tom' in any of their values.

PHP parse/syntax errors; and how to solve them

Unexpected '.'

This can occur if you are trying to use the splat operator(...) in an unsupported version of PHP.

... first became available in PHP 5.6 to capture a variable number of arguments to a function:

function concatenate($transform, ...$strings) {
    $string = '';
    foreach($strings as $piece) {
        $string .= $piece;
    }
    return($transform($string));
}

echo concatenate("strtoupper", "I'd ", "like ", 4 + 2, " apples");
// This would print:
// I'D LIKE 6 APPLES

In PHP 7.4, you could use it for Array expressions.

$parts = ['apple', 'pear'];
$fruits = ['banana', 'orange', ...$parts, 'watermelon'];
// ['banana', 'orange', 'apple', 'pear', 'watermelon'];

What's the difference between process.cwd() vs __dirname?

Knowing the scope of each can make things easier to remember.

process is node's global object, and .cwd() returns where node is running.

__dirname is module's property, and represents the file path of the module. In node, one module resides in one file.

Similarly, __filename is another module's property, which holds the file name of the module.

How to retrieve Request Payload

If I understand the situation correctly, you are just passing json data through the http body, instead of application/x-www-form-urlencoded data.

You can fetch this data with this snippet:

$request_body = file_get_contents('php://input');

If you are passing json, then you can do:

$data = json_decode($request_body);

$data then contains the json data is php array.

php://input is a so called wrapper.

php://input is a read-only stream that allows you to read raw data from the request body. In the case of POST requests, it is preferable to use php://input instead of $HTTP_RAW_POST_DATA as it does not depend on special php.ini directives. Moreover, for those cases where $HTTP_RAW_POST_DATA is not populated by default, it is a potentially less memory intensive alternative to activating always_populate_raw_post_data. php://input is not available with enctype="multipart/form-data".

What's a good (free) visual merge tool for Git? (on windows)

On Windows, a good 3-way diff/merge tool remains kdiff3 (WinMerge, for now, is still 2-way based, pending WinMerge3)

See "How do you merge in GIT on Windows?" and this config.


Update 7 years later (Aug. 2018): Artur Kedzior mentions in the comments:

If you guys happen to use Visual Studio (Community Edition is free), try the tool that is shipped with it: vsDiffMerge.exe. It's really awesome and easy to use.

"pip install json" fails on Ubuntu

While it's true that json is a built-in module, I also found that on an Ubuntu system with python-minimal installed, you DO have python but you can't do import json. And then I understand that you would try to install the module using pip!

If you have python-minimal you'll get a version of python with less modules than when you'd typically compile python yourself, and one of the modules you'll be missing is the json module. The solution is to install an additional package, called libpython2.7-stdlib, to install all 'default' python libraries.

sudo apt install libpython2.7-stdlib

And then you can do import json in python and it would work!

How to stop EditText from gaining focus at Activity startup in Android

EditText within a ListView does not work properly. It's better to use TableLayout with automatically generated rows when you are using EditText.

Dynamically add event listener

I aso find this extremely confusing. as @EricMartinez points out Renderer2 listen() returns the function to remove the listener:

ƒ () { return element.removeEventListener(eventName, /** @type {?} */ (handler), false); }

If i´m adding a listener

this.listenToClick = this.renderer.listen('document', 'click', (evt) => {
    alert('Clicking the document');
})

I´d expect my function to execute what i intended, not the total opposite which is remove the listener.

// I´d expect an alert('Clicking the document'); 
this.listenToClick();
// what you actually get is removing the listener, so nothing...

In the given scenario, It´d actually make to more sense to name it like:

// Add listeners
let unlistenGlobal = this.renderer.listen('document', 'click', (evt) => {
    console.log('Clicking the document', evt);
})

let removeSimple = this.renderer.listen(this.myButton.nativeElement, 'click', (evt) => {
    console.log('Clicking the button', evt);
});

There must be a good reason for this but in my opinion it´s very misleading and not intuitive.

How to clear https proxy setting of NPM?

npm config rm proxy
npm config rm https-proxy
unset HTTP_PROXY
unset HTTPS_PROXY
unset http_proxy
unset https_proxy

Damn finally this does the trick in Debian Jessie with privoxy (ad remover) installed, Thank you :-)

Calculate the mean by group

We already have tons of options to get mean by group, adding one more from mosaic package.

mosaic::mean(speed~dive, data = df)
#dive1 dive2 
#0.579 0.440 

This returns a named numeric vector, if needed a dataframe we can wrap it in stack

stack(mosaic::mean(speed~dive, data = df))

#  values   ind
#1  0.579 dive1
#2  0.440 dive2

data

set.seed(123)
df <- data.frame(dive=factor(sample(c("dive1","dive2"),10,replace=TRUE)),
                 speed=runif(10))

Button Center CSS

I realize this is a very old question, but I stumbled across this problem today and I got it to work with

<div style="text-align:center;">
    <button>button1</button>
    <button>button2</button>
</div>

Cheers, Mark