Programs & Examples On #Cumulative sum

Create a Cumulative Sum Column in MySQL

UPDATE t
SET cumulative_sum = (
 SELECT SUM(x.count)
 FROM t x
 WHERE x.id <= t.id
)

Calculate a Running Total in SQL Server

You can also denormalize - store running totals in the same table:

http://sqlblog.com/blogs/alexander_kuznetsov/archive/2009/01/23/denormalizing-to-enforce-business-rules-running-totals.aspx

Selects work much faster than any other solutions, but modifications may be slower

Disallow Twitter Bootstrap modal window from closing

You can also include these attributes in the modal definition itself:

<div class="modal hide fade" data-keyboard="false" data-backdrop="static">

How to POST form data with Spring RestTemplate?

How to POST mixed data: File, String[], String in one request.

You can use only what you need.

private String doPOST(File file, String[] array, String name) {
    RestTemplate restTemplate = new RestTemplate(true);

    //add file
    LinkedMultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
    params.add("file", new FileSystemResource(file));

    //add array
    UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl("https://my_url");
    for (String item : array) {
        builder.queryParam("array", item);
    }

    //add some String
    builder.queryParam("name", name);

    //another staff
    String result = "";
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.MULTIPART_FORM_DATA);

    HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity =
            new HttpEntity<>(params, headers);

    ResponseEntity<String> responseEntity = restTemplate.exchange(
            builder.build().encode().toUri(),
            HttpMethod.POST,
            requestEntity,
            String.class);

    HttpStatus statusCode = responseEntity.getStatusCode();
    if (statusCode == HttpStatus.ACCEPTED) {
        result = responseEntity.getBody();
    }
    return result;
}

The POST request will have File in its Body and next structure:

POST https://my_url?array=your_value1&array=your_value2&name=bob 

How to return only 1 row if multiple duplicate rows and still return rows that are not duplicates?

select * from temptable
where rnum --unique key
 in 

( 
 SELECT RNUM --unique key
  FROM temptable
 WHERE (  HistoryStatus
) IN (SELECT                HistoryStatus

                             FROM temptable
                            GROUP BY                
HistoryStatus 
                           HAVING COUNT(*) <= 1));

I have not tested this code. I have used similar code and it works. The syntax is in Oracle.

ASP.Net Download file to client browser

Just a slight addition to the above solution if you are having problem with downloaded file's name...

Response.AddHeader("Content-Disposition", "attachment; filename=\"" + file.Name + "\"");

This will return the exact file name even if it contains spaces or other characters.

Path of currently executing powershell script

From Get-ScriptDirectory to the Rescue blog entry ...

function Get-ScriptDirectory
{
  $Invocation = (Get-Variable MyInvocation -Scope 1).Value
  Split-Path $Invocation.MyCommand.Path
}

How do I rotate a picture in WinForms

I found this article

  /// <summary>
    /// Creates a new Image containing the same image only rotated
    /// </summary>
    /// <param name=""image"">The <see cref=""System.Drawing.Image"/"> to rotate
    /// <param name=""offset"">The position to rotate from.
    /// <param name=""angle"">The amount to rotate the image, clockwise, in degrees
    /// <returns>A new <see cref=""System.Drawing.Bitmap"/"> of the same size rotated.</see>
    /// <exception cref=""System.ArgumentNullException"">Thrown if <see cref=""image"/"> 
    /// is null.</see>
    public static Bitmap RotateImage(Image image, PointF offset, float angle)
    {
        if (image == null)
            throw new ArgumentNullException("image");

        //create a new empty bitmap to hold rotated image
        Bitmap rotatedBmp = new Bitmap(image.Width, image.Height);
        rotatedBmp.SetResolution(image.HorizontalResolution, image.VerticalResolution);

        //make a graphics object from the empty bitmap
        Graphics g = Graphics.FromImage(rotatedBmp);

        //Put the rotation point in the center of the image
        g.TranslateTransform(offset.X, offset.Y);

        //rotate the image
        g.RotateTransform(angle);

        //move the image back
        g.TranslateTransform(-offset.X, -offset.Y);

        //draw passed in image onto graphics object
        g.DrawImage(image, new PointF(0, 0));

        return rotatedBmp;
    }

How to make a parent div auto size to the width of its children divs

The parent div (I assume the outermost div) is display: block and will fill up all available area of its container (in this case, the body) that it can. Use a different display type -- inline-block is probably what you are going for:

http://jsfiddle.net/a78xy/

BAT file: Open new cmd window and execute a command in there

You may already find your answer because it was some time ago you asked. But I tried to do something similar when coding ror. I wanted to run "rails server" in a new cmd window so I don't have to open a new cmd and then find my path again.

What I found out was to use the K switch like this:

start cmd /k echo Hello, World!

start before "cmd" will open the application in a new window and "/K" will execute "echo Hello, World!" after the new cmd is up.

You can also use the /C switch for something similar.

start cmd /C pause

This will then execute "pause" but close the window when the command is done. In this case after you pressed a button. I found this useful for "rails server", then when I shutdown my dev server I don't have to close the window after.


Use the following in your batch file:

start cmd.exe /c "more-batch-commands-here"

or

start cmd.exe /k "more-batch-commands-here"

/c Carries out the command specified by string and then terminates

/k Carries out the command specified by string but remains

The /c and /k options controls what happens once your command finishes running. With /c the terminal window will close automatically, leaving your desktop clean. With /k the terminal window will remain open. It's a good option if you want to run more commands manually afterwards.

Consult the cmd.exe documentation using cmd /? for more details.

Escaping Commands with White Spaces

The proper formatting of the command string becomes more complicated when using arguments with spaces. See the examples below. Note the nested double quotes in some examples.

Examples:

Run a program and pass a filename parameter:
CMD /c write.exe c:\docs\sample.txt

Run a program and pass a filename which contains whitespace:
CMD /c write.exe "c:\sample documents\sample.txt"

Spaces in program path:
CMD /c ""c:\Program Files\Microsoft Office\Office\Winword.exe""

Spaces in program path + parameters:
CMD /c ""c:\Program Files\demo.cmd"" Parameter1 Param2
CMD /k ""c:\batch files\demo.cmd" "Parameter 1 with space" "Parameter2 with space""

Launch demo1 and demo2:
CMD /c ""c:\Program Files\demo1.cmd" & "c:\Program Files\demo2.cmd""

Source: http://ss64.com/nt/cmd.html

How can I make a CSS table fit the screen width?

There is already a good solution to the problem you are having. Everyone has been forgetting the CSS property font-size: the last but not least solution. One can decrease the font size by 2 to 3 pixels. It may still be visible to the user and for somewhat you can decrease the width of the table. This worked for me. My table has 5 columns with 4 showing perfectly, but the fifth column went out of the viewport. To fix the problem, I decreased the font size and all five columns were fitted onto the screen.

table th td {
  font-size: 14px;
}

For your information, if your table has too many columns and you are not able to decrease, then make the font size small. It will get rid of the horizontal scroll. There are two advantages: your style for mobile web will remain the same (good without horizontal scroll) and when user sees small sizes, most users will zoom into the table to their comfort level.

How can I make a Python script standalone executable to run without ANY dependency?

You might wish to investigate Nuitka. It takes Python source code and converts it in to C++ API calls. Then it compiles into an executable binary (ELF on Linux). It has been around for a few years now and supports a wide range of Python versions.

You will probably also get a performance improvement if you use it. It is recommended.

Flutter.io Android License Status Unknown

I downgraded my Java version to 1.8 and its resolved, here is the link to download JDK8

Run the following command after installing JDK8

   flutter doctor --android-licenses

SQL Server Management Studio, how to get execution time down to milliseconds

Turn on Client Statistics by doing one of the following:

  • Menu: Query > Include client Statistics
  • Toolbar: Click the button (next to Include Actual Execution Time)
  • Keyboard: Shift-Alt-S

Then you get a new tab which records the timings, IO data and rowcounts etc for (up to) the last 10 exections (plus averages!):

enter image description here

Does Git Add have a verbose switch

For some git-commands you can specify --verbose,

git 'command' --verbose

or

git 'command' -v.

Make sure the switch is after the actual git command. Otherwise - it won't work!

Also useful:

git 'command' --dry-run 

Disable submit button on form submit

This should take care of it in your app.

$(":submit").closest("form").submit(function(){
    $(':submit').attr('disabled', 'disabled');
});

Retrofit and GET using parameters

AFAIK, {...} can only be used as a path, not inside a query-param. Try this instead:

public interface FooService {    

    @GET("/maps/api/geocode/json?sensor=false")
    void getPositionByZip(@Query("address") String address, Callback<String> cb);
}

If you have an unknown amount of parameters to pass, you can use do something like this:

public interface FooService {    

    @GET("/maps/api/geocode/json")
    @FormUrlEncoded
    void getPositionByZip(@FieldMap Map<String, String> params, Callback<String> cb);
}

How to stop event propagation with inline onclick attribute?

Use event.stopPropagation().

<span onclick="event.stopPropagation(); alert('you clicked inside the header');">something inside the header</span>

For IE: window.event.cancelBubble = true

<span onclick="window.event.cancelBubble = true; alert('you clicked inside the header');">something inside the header</span>

curl -GET and -X GET

-X [your method]
X lets you override the default 'Get'

** corrected lowercase x to uppercase X

SQL Server database restore error: specified cast is not valid. (SqlManagerUI)

Finally got this error to go away on a restore. I moved to SQL2012 out of frustration, but I guess this would probably still work on 2008R2. I had to use the logical names:

RESTORE FILELISTONLY
FROM DISK = ‘location of your.bak file’

And from there I ran a restore statement with MOVE using logical names.

RESTORE DATABASE database1
FROM DISK = '\\database path\database.bak'
WITH
MOVE 'File_Data' TO 'E:\location\database.mdf',
MOVE 'File_DOCS' TO 'E:\location\database_1.ndf',
MOVE 'file' TO 'E:\location\database_2.ndf',
MOVE 'file' TO 'E:\location\database_3.ndf',
MOVE 'file_Log' TO 'E:\location\database.ldf'

When it was done restoring, I almost wept with joy.

Good luck!

What data type to use for money in Java?

An integral type representing the smallest value possible. In other words your program should think in cents not in dollars/euros.

This should not stop you from having the gui translate it back to dollars/euros.

Outline effect to text

I had this issue as well, and the text-shadow wasn't an option because the corners would look bad (unless I had many many shadows), and I didn't want any blur, therefore my only other option was to do the following: Have 2 divs, and for the background div, put a -webkit-text-stroke on it, which then allows for as big of an outline as you like.

_x000D_
_x000D_
div {_x000D_
  font-size: 200px;_x000D_
  position: absolute;_x000D_
  white-space: nowrap;_x000D_
}_x000D_
_x000D_
.front {_x000D_
 color: blue;_x000D_
}_x000D_
_x000D_
.outline {_x000D_
  -webkit-text-stroke: 30px red;_x000D_
  user-select: none;_x000D_
}
_x000D_
<div class="outline">_x000D_
 outline text_x000D_
</div>_x000D_
_x000D_
<div class="front">_x000D_
 outline text_x000D_
</div>  
_x000D_
_x000D_
_x000D_

Using this, I was able to achieve an outline, because the stroke-width method was not an option if you want your text to remain legible with a very large outline (because with stroke-width the outline will start inside the lettering which makes it not legible when the width gets larger than the letters.

Note: the reason I needed such a fat outline was I was emulating the street labels in "google maps" and I wanted a fat white halo around the text. This solution worked perfectly for me.

Here is a fiddle showing this solution

enter image description here

Array functions in jQuery

Look into the jQuery functions .grep() and .map()

SQL Error: ORA-00913: too many values

The 00947 message indicates that the record which you are trying to send to Oracle lacks one or more of the columns which was included at the time the table was created. The 00913 message indicates that the record which you are trying to send to Oracle includes more columns than were included at the time the table was created. You just need to check the number of columns and its type in both the tables ie the tables that are involved in the sql.

Call ASP.NET function from JavaScript?

Please try this:

<%= Page.ClientScript.GetPostBackEventReference(ddlVoucherType, String.Empty) %>;

ddlVoucherType is a control which the selected index change will call... And you can put any function on the selected index change of this control.

Redirect to Action in another controller

Use this:

return RedirectToAction("LogIn", "Account", new { area = "" });

This will redirect to the LogIn action in the Account controller in the "global" area.

It's using this RedirectToAction overload:

protected internal RedirectToRouteResult RedirectToAction(
    string actionName,
    string controllerName,
    Object routeValues
)

MSDN

Better techniques for trimming leading zeros in SQL Server?

For converting number as varchar to int, you could also use simple

(column + 0)

What is "not assignable to parameter of type never" error in typescript?

I got the same error in ReactJS function component, using ReactJS useState hook. The solution was to declare the type of useState at initialisation:

const [items , setItems] = useState<IItem[]>([]); // replace IItem[] with your own typing: string, boolean...

Converting dictionary to JSON

No need to convert it in a string by using json.dumps()

r = {'is_claimed': 'True', 'rating': 3.5}
file.write(r['is_claimed'])
file.write(str(r['rating']))

You can get the values directly from the dict object.

Set up Python simpleHTTPserver on Windows

From Stack Overflow question What is the Python 3 equivalent of "python -m SimpleHTTPServer":

The following works for me:

python -m http.server [<portNo>]

Because I am using Python 3 the module SimpleHTTPServer has been replaced by http.server, at least in Windows.

How do I remove a CLOSE_WAIT socket connection

Even though too much of CLOSE_WAIT connections means there is something wrong with your code in the first and this is accepted not good practice.

You might want to check out: https://github.com/rghose/kill-close-wait-connections

What this script does is send out the ACK which the connection was waiting for.

This is what worked for me.

Jquery .on('scroll') not firing the event while scrolling

You probably forgot to give # before id for id selector, you need to give # before id ie is ulId

You problably need to bind scroll event on div that contains the ul and scrolls. You need to bind the event with div instead of ul

$(document).on( 'scroll', '#idOfDivThatContainsULandScroll', function(){
    console.log('Event Fired');
});

Edit

The above would not work because the scroll event does not bubble up in DOM which is used for event delegation, see this question why doesn't delegate work for scroll?

But with modern browsers > IE 8 you can do it by other way. Instead of delegating by using jquery you can do it using event capturing with java script document.addEventListener, with the third argument as true; see how bubbling and capturing work in this tuturial.

Live Demo

document.addEventListener('scroll', function (event) {
    if (event.target.id === 'idOfUl') { // or any other filtering condition        
        console.log('scrolling', event.target);
    }
}, true /*Capture event*/);

If you do not need event delegation then you can bind scroll event directly to the ul instead of delegating it through document.

Live Demo

$("#idOfUl").on( 'scroll', function(){
   console.log('Event Fired');
});

How to easily initialize a list of Tuples?

Old question, but this is what I typically do to make things a bit more readable:

Func<int, string, Tuple<int, string>> tc = Tuple.Create;

var tupleList = new List<Tuple<int, string>>
{
    tc( 1, "cow" ),
    tc( 5, "chickens" ),
    tc( 1, "airplane" )
};

How to reduce a huge excel file

I had an excel file 24MB in Size, thanks to over a 100 images within. I reduced the size to less than 5MB by the following steps:

  1. Selected each Picture, cut it (CTRL X) and pasted it in special mode by ALT E S Bitmap option
  2. To find which Bitmap was still large, One has to select one of the files per sheet, then do CTRL A. This will select all Images.
  3. Double Click on any one image and the RESET Picture option appears on top.
  4. Click on reset picture and all Images that are still large show up.
  5. Do a CTRL Z (UNDO) and now again paste these balance images in BITMAP (*.BMP) like step 1.

It took me 2 days to figure this out as this wasnt listed in any help forum. Hope this response helps someone

BR Gautam Dalal (India)

How the single threaded non blocking IO model works in Node.js

Node.js uses libuv behind the scenes. libuv has a thread pool (of size 4 by default). Therefore Node.js does use threads to achieve concurrency.

However, your code runs on a single thread (i.e., all of the callbacks of Node.js functions will be called on the same thread, the so called loop-thread or event-loop). When people say "Node.js runs on a single thread" they are really saying "the callbacks of Node.js run on a single thread".

How to express a One-To-Many relationship in Django

To be more clear - there's no OneToMany in Django, only ManyToOne - which is Foreignkey described above. You can describe OneToMany relation using Foreignkey but that is very inexpressively.

A good article about it: https://amir.rachum.com/blog/2013/06/15/a-case-for-a-onetomany-relationship-in-django/

Remove duplicate elements from array in Ruby

You can return the intersection.

a = [1,1,2,3]
a & a

This will also delete duplicates.

@try - catch block in Objective-C

All work perfectly :)

 NSString *test = @"test";
 unichar a;
 int index = 5;
    
 @try {
    a = [test characterAtIndex:index];
 }
 @catch (NSException *exception) {
    NSLog(@"%@", exception.reason);
    NSLog(@"Char at index %d cannot be found", index);
    NSLog(@"Max index is: %lu", [test length] - 1);
 }
 @finally {
    NSLog(@"Finally condition");
 }

Log:

[__NSCFConstantString characterAtIndex:]: Range or index out of bounds

Char at index 5 cannot be found

Max index is: 3

Finally condition

How to upload a project to Github

  1. We need Git Bash
  2. In Git Bash Command Section::

1.1 ls

It will show you default location.

1.2 CD "C:\Users\user\Desktop\HTML" We need to assign project path

1.3 git init It will initialize the empty git repository in C:\Users\user\Desktop\HTML

1.4 ls It will list all files name

1.5 git remote add origin https://github.com/repository/test.git it is your https://github.com/repository/test.git is your repository path

1.6 git remote -v To check weather we have fetch or push permisson or not

1.7 git add . If you put . then it mean whatever we have in perticular folder publish all.

1.8 git commit -m "First time"

1.9 git push -u origin master

add Shadow on UIView using swift 3

Very simple and few lines of code:

let viewShadow = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
viewShadow.center = self.view.center
viewShadow.backgroundColor = UIColor.yellow
viewShadow.layer.shadowColor = UIColor.red.cgColor
viewShadow.layer.shadowOpacity = 1
viewShadow.layer.shadowOffset = CGSize.zero
viewShadow.layer.shadowRadius = 5
self.view.addSubview(viewShadow)

Look like : enter image description here

PIL image to array (numpy array to array) - Python

I use numpy.fromiter to invert a 8-greyscale bitmap, yet no signs of side-effects

import Image
import numpy as np

im = Image.load('foo.jpg')
im = im.convert('L')

arr = np.fromiter(iter(im.getdata()), np.uint8)
arr.resize(im.height, im.width)

arr ^= 0xFF  # invert
inverted_im = Image.fromarray(arr, mode='L')
inverted_im.show()

Disable sorting for a particular column in jQuery DataTables

"aoColumnDefs" : [   
{
  'bSortable' : false,  
  'aTargets' : [ 0 ]
}]

Here 0 is the index of the column, if you want multiple columns to be not sorted, mention column index values seperated by comma(,)

Map with Key as String and Value as List in Groovy

you don't need to declare Map groovy internally recognizes it

def personDetails = [firstName:'John', lastName:'Doe', fullName:'John Doe']

// print the values..
    println "First Name: ${personDetails.firstName}"
    println "Last Name: ${personDetails.lastName}"

http://grails.asia/groovy-map-tutorial

Create iOS Home Screen Shortcuts on Chrome for iOS

The is no API for adding a shortcut to the home screen in iOS, so no third-party browser is capable of providing that functionality.

RS256 vs HS256: What's the difference?

There is a difference in performance.

Simply put HS256 is about 1 order of magnitude faster than RS256 for verification but about 2 orders of magnitude faster than RS256 for issuing (signing).

 640,251  91,464.3 ops/s
  86,123  12,303.3 ops/s (RS256 verify)
   7,046   1,006.5 ops/s (RS256 sign)

Don't get hung up on the actual numbers, just think of them with respect of each other.

[Program.cs]

class Program
{
    static void Main(string[] args)
    {
        foreach (var duration in new[] { 1, 3, 5, 7 })
        {
            var t = TimeSpan.FromSeconds(duration);

            byte[] publicKey, privateKey;

            using (var rsa = new RSACryptoServiceProvider())
            {
                publicKey = rsa.ExportCspBlob(false);
                privateKey = rsa.ExportCspBlob(true);
            }

            byte[] key = new byte[64];

            using (var rng = new RNGCryptoServiceProvider())
            {
                rng.GetBytes(key);
            }

            var s1 = new Stopwatch();
            var n1 = 0;

            using (var hs256 = new HMACSHA256(key))
            {
                while (s1.Elapsed < t)
                {
                    s1.Start();
                    var hash = hs256.ComputeHash(privateKey);
                    s1.Stop();
                    n1++;
                }
            }

            byte[] sign;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(privateKey);

                sign = rsa.SignData(privateKey, "SHA256");
            }

            var s2 = new Stopwatch();
            var n2 = 0;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(publicKey);

                while (s2.Elapsed < t)
                {
                    s2.Start();
                    var success = rsa.VerifyData(privateKey, "SHA256", sign);
                    s2.Stop();
                    n2++;
                }
            }

            var s3 = new Stopwatch();
            var n3 = 0;

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.ImportCspBlob(privateKey);

                while (s3.Elapsed < t)
                {
                    s3.Start();
                    rsa.SignData(privateKey, "SHA256");
                    s3.Stop();
                    n3++;
                }
            }

            Console.WriteLine($"{s1.Elapsed.TotalSeconds:0} {n1,7:N0} {n1 / s1.Elapsed.TotalSeconds,9:N1} ops/s");
            Console.WriteLine($"{s2.Elapsed.TotalSeconds:0} {n2,7:N0} {n2 / s2.Elapsed.TotalSeconds,9:N1} ops/s");
            Console.WriteLine($"{s3.Elapsed.TotalSeconds:0} {n3,7:N0} {n3 / s3.Elapsed.TotalSeconds,9:N1} ops/s");

            Console.WriteLine($"RS256 is {(n1 / s1.Elapsed.TotalSeconds) / (n2 / s2.Elapsed.TotalSeconds),9:N1}x slower (verify)");
            Console.WriteLine($"RS256 is {(n1 / s1.Elapsed.TotalSeconds) / (n3 / s3.Elapsed.TotalSeconds),9:N1}x slower (issue)");

            // RS256 is about 7.5x slower, but it can still do over 10K ops per sec.
        }
    }
}

How can I hash a password in Java?

You can comput hashes using MessageDigest, but this is wrong in terms of security. Hashes are not to be used for storing passwords, as they are easily breakable.

You should use another algorithm like bcrypt, PBKDF2 and scrypt to store you passwords. See here.

passing form data to another HTML page

_x000D_
_x000D_
<form action="display.html" method="post">_x000D_
    <input type="text" name="serialNumber" />_x000D_
    <input type="submit" value="Submit" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

In display.html you should add the following code.

<script>
function getParameterByName(name, url) {
    if (!url) url = window.location.href;
    name = name.replace(/[\[\]]/g, '\\$&');
    var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)'),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, ' '));
}

var sn = getParameterByName('serialNumber');

document.getElementById("write").innerHTML = sn;

</script>

Is it possible to get an Excel document's row count without loading the entire document into memory?

The solution suggested in this answer has been deprecated, and might no longer work.


Taking a look at the source code of OpenPyXL (IterableWorksheet) I've figured out how to get the column and row count from an iterator worksheet:

wb = load_workbook(path, use_iterators=True)
sheet = wb.worksheets[0]

row_count = sheet.get_highest_row() - 1
column_count = letter_to_index(sheet.get_highest_column()) + 1

IterableWorksheet.get_highest_column returns a string with the column letter that you can see in Excel, e.g. "A", "B", "C" etc. Therefore I've also written a function to translate the column letter to a zero based index:

def letter_to_index(letter):
    """Converts a column letter, e.g. "A", "B", "AA", "BC" etc. to a zero based
    column index.

    A becomes 0, B becomes 1, Z becomes 25, AA becomes 26 etc.

    Args:
        letter (str): The column index letter.
    Returns:
        The column index as an integer.
    """
    letter = letter.upper()
    result = 0

    for index, char in enumerate(reversed(letter)):
        # Get the ASCII number of the letter and subtract 64 so that A
        # corresponds to 1.
        num = ord(char) - 64

        # Multiply the number with 26 to the power of `index` to get the correct
        # value of the letter based on it's index in the string.
        final_num = (26 ** index) * num

        result += final_num

    # Subtract 1 from the result to make it zero-based before returning.
    return result - 1

I still haven't figured out how to get the column sizes though, so I've decided to use a fixed-width font and automatically scaled columns in my application.

CMAKE_MAKE_PROGRAM not found

It also happens when I just want to compile opencv2.3.2 with mingw32 (in tdm-gcc suites). Often when I install the tdm-gcc, I would like to rename the mingw32-make.exe to make.exe. And I thinks this could be the question. If cmake is asked to generated a MinGW Makefiles, It would try to find ming32-make.exe instead of make.exe. So I copy the make.exe to mingw32-make.exe and reconfigure in Cmake-gui. Finally it works! So I'd like to advise to find whether you have mingw32-make.exe or not to solve this question.

What does %>% function mean in R?

%>% is similar to pipe in Unix. For example, in

a <- combined_data_set %>% group_by(Outlet_Identifier) %>% tally()

the output of combined_data_set will go into group_by and its output will go into tally, then the final output is assigned to a.

This gives you handy and easy way to use functions in series without creating variables and storing intermediate values.

How to turn on/off MySQL strict mode in localhost (xampp)?

on Debian 10 I start mysql from ./opt/lampp/xampp start

I do strace ./opt/lampp/sbin/mysqld and see that my.cnf is there:

stat("/opt/lampp/etc/my.cnf", {st_mode=S_IFREG|0644, st_size=5050, ...}) = 0
openat(AT_FDCWD, "/opt/lampp/etc/my.cnf", O_RDONLY|O_CLOEXEC) = 3

hence, I add sql_mode config to /opt/lampp/etc/my.cnf instead of /etc/mysql/my.cnf

When should I use double or single quotes in JavaScript?

There isn't any difference between single and double quotes in JavaScript.

The specification is important:

Maybe there are performance differences, but they are absolutely minimum and can change any day according to browsers' implementation. Further discussion is futile unless your JavaScript application is hundreds of thousands lines long.

It's like a benchmark if

a=b;

is faster than

a = b;

(extra spaces)

today, in a particular browser and platform, etc.

What are the main differences between JWT and OAuth authentication?

JWT is an open standard that defines a compact and self-contained way for securely transmitting information between parties. It is an authentication protocol where we allow encoded claims (tokens) to be transferred between two parties (client and server) and the token is issued upon the identification of a client. With each subsequent request we send the token.

Whereas OAuth2 is an authorization framework, where it has a general procedures and setups defined by the framework. JWT can be used as a mechanism inside OAuth2.

You can read more on this here

OAuth or JWT? Which one to use and why?

Count unique values with pandas per groups

Generally to count distinct values in single column, you can use Series.value_counts:

df.domain.value_counts()

#'vk.com'          5
#'twitter.com'     2
#'facebook.com'    1
#'google.com'      1
#Name: domain, dtype: int64

To see how many unique values in a column, use Series.nunique:

df.domain.nunique()
# 4

To get all these distinct values, you can use unique or drop_duplicates, the slight difference between the two functions is that unique return a numpy.array while drop_duplicates returns a pandas.Series:

df.domain.unique()
# array(["'vk.com'", "'twitter.com'", "'facebook.com'", "'google.com'"], dtype=object)

df.domain.drop_duplicates()
#0          'vk.com'
#2     'twitter.com'
#4    'facebook.com'
#6      'google.com'
#Name: domain, dtype: object

As for this specific problem, since you'd like to count distinct value with respect to another variable, besides groupby method provided by other answers here, you can also simply drop duplicates firstly and then do value_counts():

import pandas as pd
df.drop_duplicates().domain.value_counts()

# 'vk.com'          3
# 'twitter.com'     2
# 'facebook.com'    1
# 'google.com'      1
# Name: domain, dtype: int64

Replace single quotes in SQL Server

The striping/replacement/scaping of single quotes from user input (input sanitation), has to be done before the SQL statement reaches the database.

Element-wise addition of 2 lists?

Although, the actual question does not want to iterate over the list to generate the result, but all the solutions that has been proposed does exactly that under-neath the hood!

To refresh: You cannot add two vectors without looking into all the vector elements. So, the algorithmic complexity of most of these solutions are Big-O(n). Where n is the dimension of the vector.

So, from an algorithmic point of view, using a for loop to iteratively generate the resulting list is logical and pythonic too. However, in addition, this method does not have the overhead of calling or importing any additional library.

# Assumption: The lists are of equal length.
resultList = [list1[i] + list2[i] for i in range(len(list1))]

The timings that are being showed/discussed here are system and implementation dependent, and cannot be reliable measure to measure the efficiency of the operation. In any case, the big O complexity of the vector addition operation is linear, meaning O(n).

How to cherry pick from 1 branch to another

When you cherry-pick, it creates a new commit with a new SHA. If you do:

git cherry-pick -x <sha>

then at least you'll get the commit message from the original commit appended to your new commit, along with the original SHA, which is very useful for tracking cherry-picks.

Getting DOM element value using pure JavaScript

In the second version, you're passing the String returned from this.id. Not the element itself.

So id.value won't give you what you want.

You would need to pass the element with this.

doSomething(this)

then:

function(el){
    var value = el.value;
    ...
}

Note: In some browsers, the second one would work if you did:

window[id].value 

because element IDs are a global property, but this is not safe.

It makes the most sense to just pass the element with this instead of fetching it again with its ID.

Bootstrap: change background color

You could hard code it.

<div class="col-md-6" style="background-color:blue;">
</div>

<div class="col-md-6" style="background-color:white;">
</div>

jQuery Ajax calls and the Html.AntiForgeryToken()

I was just implementing this actual problem in my current project. i did it for all ajax-POSTs that needed an authenticated user.

First off i decided to hook my jquery ajax calls so i do not to repeat myself too often. this javascript snippet ensures all ajax (post) calls will add my request validation token to the request. Note: the name __RequestVerificationToken is used by the .Net framework so i can utilize the standard Anti-CSRF features as shown below.

$(document).ready(function () {
    var securityToken = $('[name=__RequestVerificationToken]').val();
    $('body').bind('ajaxSend', function (elm, xhr, s) {
        if (s.type == 'POST' && typeof securityToken != 'undefined') {
            if (s.data.length > 0) {
                s.data += "&__RequestVerificationToken=" + encodeURIComponent(securityToken);
            }
            else {
                s.data = "__RequestVerificationToken=" + encodeURIComponent(securityToken);
            }
        }
    });
});

In your Views where you need the token to be available to the above javascript just use the common HTML-Helper. You can basically add this code whereever you want. I placed it within a if(Request.IsAuthenticated) statement:

@Html.AntiForgeryToken() // you can provide a string as salt when needed which needs to match the one on the controller

In your controller simply use the standard ASP.Net MVC Anti-CSRF mechanism. I did it like this (though i actually used Salt).

[HttpPost]
[Authorize]
[ValidateAntiForgeryToken]
public JsonResult SomeMethod(string param)
{
    // do something
    return Json(true);
}

With Firebug or a similar tool you can easily see how your POST requests now have a __RequestVerificationToken parameter appended.

SQL alias for SELECT statement

You could store this into a temporary table.

So instead of doing the CTE/sub query you would use a temp table.

Good article on these here http://codingsight.com/introduction-to-temporary-tables-in-sql-server/

insert data from one table to another in mysql

INSERT INTO mt_magazine_subscription SELECT *
       FROM tbl_magazine_subscription 
       ORDER BY magazine_subscription_id ASC

How can I select item with class within a DIV?

try this instead $(".video-divs.focused"). This works if you are looking for video-divs that are focused.

Bash or KornShell (ksh)?

This is a bit of a Unix vs Linux battle. Most if not all Linux distributions have bash installed and ksh optional. Most Unix systems, like Solaris, AIX and HPUX have ksh as default.

Personally I always use ksh, I love the vi completion and I pretty much use Solaris for everything.

Sort dataGridView columns in C# ? (Windows Form)

Use Datatable.Default.Sort property and then bind it to the datagridview.

How to get margin value of a div in plain JavaScript?

Also, you can create your own outerHeight for HTML elements. I don't know if it works in IE, but it works in Chrome. Perhaps, you can enhance the code below using currentStyle, suggested in the answer above.

Object.defineProperty(Element.prototype, 'outerHeight', {
    'get': function(){
        var height = this.clientHeight;
        var computedStyle = window.getComputedStyle(this); 
        height += parseInt(computedStyle.marginTop, 10);
        height += parseInt(computedStyle.marginBottom, 10);
        height += parseInt(computedStyle.borderTopWidth, 10);
        height += parseInt(computedStyle.borderBottomWidth, 10);
        return height;
    }
});

This piece of code allow you to do something like this:

document.getElementById('foo').outerHeight

According to caniuse.com, getComputedStyle is supported by main browsers (IE, Chrome, Firefox).

PHP get dropdown value and text

Is there a reason you didn't just use this?

<select id="animal" name="animal">                      
  <option value="0">--Select Animal--</option>
  <option value="Cat">Cat</option>
  <option value="Dog">Dog</option>
  <option value="Cow">Cow</option>
</select>

if($_POST['submit'] && $_POST['submit'] != 0)
{
   $animal=$_POST['animal'];
}

Collision Detection between two images in Java

Since Java doesn't have an intersect function (really!?) you can do collision detection by simply comparying the X and Y, Width and Height values of the bounding boxes (rectangle) for each of the objects that could potentially collide.

So... in the base object of each colliding object... i.e. if your player and enemy have a common base you can put a simple Rectangle object called something like BoundingBox. If the common base is a built in Java class then you'll need to create a class that extends the build in class and have the player and enemy objects extend your new class or are instances of that class.

At creation (and each tick or update) you'll need to set the BoundingBox paremeters for both your player and enemy. I don't have the Rectangle class infront of me but its most likely something like X, Y, Width and finally Height. X and Y are that objects location in your game world. The width and height are self explanatory I think. They'll most likely come out from the right of the players location though so, if the X and Y were bothe at 0 and your Width and Height were both at 256 you wouldn't see anything because the character would be at the top left outside of the screen.

Anyways... to detect a collision, you'll want to compare the attributes of the player and enemy BoundingBoxes. So something like this...

 if( Player.BoundingBox.X = Enemy.BoundingBox.X && If( Player.BoundingBox.Y = Enemy.BoundingBox.Y )
 {
      //Oh noes!  The enemy and player are on top of eachother.
 }

The logic can get sort of complicated but you'll need to compare the distances between each BoundingBox and compare locations.

How to delete and recreate from scratch an existing EF Code First database

dbctx.Database.EnsureDeleted(); dbctx.Database.EnsureCreated();

Show Youtube video source into HTML5 video tag?

This answer does not work anymore, but I'm looking for a solution.

As of . 2015 / 02 / 24 . there is a website (youtubeinmp4) that allows you to download youtube videos in .mp4 format, you can exploit this (with some JavaScript) to get away with embedding youtube videos in <video> tags. Here is a demo of this in action.

##Pros

  • Fairly easy to implement.
  • Quite fast server response actually (it doesn't take that much to retrieve the videos).
  • Abstraction (the accepted solution, even if it worked properly, would only be applicable if you knew beforehand which videos you were going to play, this works for any user inputted url).

##Cons

  • It obviously depends on the youtubeinmp4.com servers and their way of providing a downloading link (which can be passed as a <video> source), so this answer may not be valid in the future.

  • You can't choose the video quality.


###JavaScript (after load)

videos = document.querySelectorAll("video");
for (var i = 0, l = videos.length; i < l; i++) {
    var video = videos[i];
    var src = video.src || (function () {
        var sources = video.querySelectorAll("source");
        for (var j = 0, sl = sources.length; j < sl; j++) {
            var source = sources[j];
            var type = source.type;
            var isMp4 = type.indexOf("mp4") != -1;
            if (isMp4) return source.src;
        }
        return null;
    })();
    if (src) {
        var isYoutube = src && src.match(/(?:youtu|youtube)(?:\.com|\.be)\/([\w\W]+)/i);
        if (isYoutube) {
            var id = isYoutube[1].match(/watch\?v=|[\w\W]+/gi);
            id = (id.length > 1) ? id.splice(1) : id;
            id = id.toString();
            var mp4url = "http://www.youtubeinmp4.com/redirect.php?video=";
            video.src = mp4url + id;
        }
    }
}

###Usage (Full)

_x000D_
_x000D_
<video controls="true">
        <source src="www.youtube.com/watch?v=3bGNuRtlqAQ" type="video/mp4" />
    </video>
_x000D_
_x000D_
_x000D_

Standard video format.

###Usage (Mini)

_x000D_
_x000D_
<video src="youtu.be/MLeIBFYY6UY" controls="true"></video>
_x000D_
_x000D_
_x000D_

A little less common but quite smaller, using the shortened url youtu.be as the src attribute directly in the <video> tag.

Capture HTML Canvas as gif/jpg/png/pdf?

if you want to emebed the canvas you can use this snippet

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <canvas id=canvas width=200 height=200></canvas>
    <iframe id='img' width=200 height=200></iframe>
    <script>
        window.onload = function() {
            var canvas = document.getElementById("canvas");
            var context = canvas.getContext("2d");
            context.fillStyle = "green";
            context.fillRect(50, 50, 100, 100);
            document.getElementById('img').src = canvas.toDataURL("image/jpeg");
            console.log(canvas.toDataURL("image/jpeg"));
        }
    </script>
</body>
</html>

Datatable date sorting dd/mm/yyyy issue

use this snippet!

$(document).ready(function() {
 $.fn.dataTable.moment = function ( format, locale ) {
    var types = $.fn.dataTable.ext.type;

    // Add type detection
    types.detect.unshift( function ( d ) {
        return moment( d, format, locale, true ).isValid() ?
            'moment-'+format :
            null;
    } );

    // Add sorting method - use an integer for the sorting
    types.order[ 'moment-'+format+'-pre' ] = function ( d ) {
        return moment( d, format, locale, true ).unix();
    };
};

$.fn.dataTable.moment('DD/MM/YYYY');

$('#example').DataTable();
});

the moment js works well for all date and time formats, add this snipper before you initialize the datatable like i've done earlier.

Also remember to load the http://momentjs.com/

How do I ignore files in a directory in Git?

It would be the former. Go by extensions as well instead of folder structure.

I.e. my example C# development ignore file:

#OS junk files
[Tt]humbs.db
*.DS_Store

#Visual Studio files
*.[Oo]bj
*.user
*.aps
*.pch
*.vspscc
*.vssscc
*_i.c
*_p.c
*.ncb
*.suo
*.tlb
*.tlh
*.bak
*.[Cc]ache
*.ilk
*.log
*.lib
*.sbr
*.sdf
ipch/
obj/
[Bb]in
[Dd]ebug*/
[Rr]elease*/
Ankh.NoLoad

#Tooling
_ReSharper*/
*.resharper
[Tt]est[Rr]esult*

#Project files
[Bb]uild/

#Subversion files
.svn

# Office Temp Files
~$*

Update

I thought I'd provide an update from the comments below. Although not directly answering the OP's question, see the following for more examples of .gitignore syntax.

Community wiki (constantly being updated):

.gitignore for Visual Studio Projects and Solutions

More examples with specific language use can be found here (thanks to Chris McKnight's comment):

https://github.com/github/gitignore

Programmatically register a broadcast receiver

package com.example.broadcastreceiver;


import android.app.Activity;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

   UserDefinedBroadcastReceiver broadCastReceiver = new UserDefinedBroadcastReceiver();

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

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.main, menu);
      return true;
   }

   /**
    * This method enables the Broadcast receiver for
    * "android.intent.action.TIME_TICK" intent. This intent get
    * broadcasted every minute.
    *
    * @param view
    */
   public void registerBroadcastReceiver(View view) {

      this.registerReceiver(broadCastReceiver, new IntentFilter(
            "android.intent.action.TIME_TICK"));
      Toast.makeText(this, "Registered broadcast receiver", Toast.LENGTH_SHORT)
            .show();
   }

   /**
    * This method disables the Broadcast receiver
    *
    * @param view
    */
   public void unregisterBroadcastReceiver(View view) {

      this.unregisterReceiver(broadCastReceiver);

      Toast.makeText(this, "unregistered broadcst receiver", Toast.LENGTH_SHORT)
            .show();
   }
}

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

This might sound stupid, but, in the first problem presented to you, you would have to see all the remaining numbers in the bag to actually add them up to find the missing number using that equation.

So, since you get to see all the numbers, just look for the number that's missing. The same goes for when two numbers are missing. Pretty simple I think. No point in using an equation when you get to see the numbers remaining in the bag.

Transform char array into String

If you have the char array null terminated, you can assign the char array to the string:

char[] chArray = "some characters";
String String(chArray);

As for your loop code, it looks right, but I will try on my controller to see if I get the same problem.

How to get Toolbar from fragment?

toolbar = (Toolbar) getView().findViewById(R.id.toolbar);
AppCompatActivity activity = (AppCompatActivity) getActivity();
activity.setSupportActionBar(toolbar);

Why would you use String.Equals over ==?

Both methods do the same functionally - they compare values.
As is written on MSDN:

But if one of your string instances is null, these methods are working differently:

string x = null;
string y = "qq";
if (x == y) // returns false
    MessageBox.Show("true");
else
    MessageBox.Show("false");

if (x.Equals(y)) // returns System.NullReferenceException: Object reference not set to an instance of an object. - because x is null !!!
    MessageBox.Show("true");
else
    MessageBox.Show("false");

Passing multiple values for a single parameter in Reporting Services

If you want to pass multiple values to RS via a query string all you need to do is repeat the report parameter for each value.

For example; I have a RS column called COLS and this column expects one or more values.

&rp:COLS=1&rp:COLS=1&rp:COLS=5 etc..

CSS selectors ul li a {...} vs ul > li > a {...}

Here > a to specifiy the color for root of li.active.menu-item

#primary-menu > li.active.menu-item > a

_x000D_
_x000D_
#primary-menu>li.active.menu-item>a {_x000D_
  color: #c19b66;_x000D_
}
_x000D_
<ul id="primary-menu">_x000D_
  <li class="active menu-item"><a>Coffee</a>_x000D_
    <ul id="sub-menu">_x000D_
      <li class="active menu-item"><a>aaa</a></li>_x000D_
      <li class="menu-item"><a>bbb</a></li>_x000D_
      <li class="menu-item"><a>ccc</a></li>_x000D_
    </ul>_x000D_
  </li>_x000D_
_x000D_
  <li class="menu-item"><a>Tea</a></li>_x000D_
  <li class="menu-item"><a>Coca Cola</a></li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Remove all padding and margin table HTML and CSS

Try this:

table { 
border-spacing: 0;
border-collapse: collapse;
}

How to do a LIKE query with linq?

Try like this

var results = db.costumers.Where(X=>X.FullName.Contains(FirstName)&&(X=>X.FullName.EndsWith(LastName))
                          .Select(X=>X);

TypeError: 'dict_keys' object does not support indexing

In Python 2 dict.keys() return a list, whereas in Python 3 it returns a generator.

You could only iterate over it's values else you may have to explicitly convert it to a list i.e. pass it to a list function.

Routing HTTP Error 404.0 0x80070002

My solution, after trying EVERYTHING:

Bad deployment, an old PrecompiledApp.config was hanging around my deploy location, and making everything not work.

My final settings that worked:

  • IIS 7.5, Win2k8r2 x64,
  • Integrated mode application pool
  • Nothing changes in the web.config - this means no special handlers for routing. Here's my snapshot of the sections a lot of other posts reference. I'm using FluorineFX, so I do have that handler added, but I did not need any others:

    <system.web>
      <compilation debug="true" targetFramework="4.0" />
      <authentication mode="None"/>
    
      <pages validateRequest="false" controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/>
      <httpRuntime requestPathInvalidCharacters=""/>
    
      <httpModules>
        <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx"/>
      </httpModules>
    </system.web>
      <system.webServer>
        <!-- Modules for IIS 7.0 Integrated mode -->
        <modules>
          <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx" />
        </modules>
    
        <!-- Disable detection of IIS 6.0 / Classic mode ASP.NET configuration -->
        <validation validateIntegratedModeConfiguration="false" />
      </system.webServer>
    
  • Global.ashx: (only method of any note)

    void Application_Start(object sender, EventArgs e) {
        // Register routes...
        System.Web.Routing.Route echoRoute = new System.Web.Routing.Route(
              "{*message}",
            //the default value for the message
              new System.Web.Routing.RouteValueDictionary() { { "message", "" } },
            //any regular expression restrictions (i.e. @"[^\d].{4,}" means "does not start with number, at least 4 chars
              new System.Web.Routing.RouteValueDictionary() { { "message", @"[^\d].{4,}" } },
              new TestRoute.Handlers.PassthroughRouteHandler()
           );
    
        System.Web.Routing.RouteTable.Routes.Add(echoRoute);
    }
    
  • PassthroughRouteHandler.cs - this achieved an automatic conversion from http://andrew.arace.info/stackoverflow to http://andrew.arace.info/#stackoverflow which would then be handled by the default.aspx:

    public class PassthroughRouteHandler : IRouteHandler {
    
        public IHttpHandler GetHttpHandler(RequestContext requestContext) {
            HttpContext.Current.Items["IncomingMessage"] = requestContext.RouteData.Values["message"];
            requestContext.HttpContext.Response.Redirect("#" + HttpContext.Current.Items["IncomingMessage"], true);
            return null;
        }
    }
    

Query to display all tablespaces in a database and datafiles

In oracle, generally speaking, there are number of facts that I will mention in following section:

  • Each database can have many Schema/User (Logical division).
  • Each database can have many tablespaces (Logical division).
  • A schema is the set of objects (tables, indexes, views, etc) that belong to a user.
  • In Oracle, a user can be considered the same as a schema.
  • A database is divided into logical storage units called tablespaces, which group related logical structures together. For example, tablespaces commonly group all of an application’s objects to simplify some administrative operations. You may have a tablespace for application data and an additional one for application indexes.

Therefore, your question, "to see all tablespaces and datafiles belong to SCOTT" is s bit wrong.

However, there are some DBA views encompass information about all database objects, regardless of the owner. Only users with DBA privileges can access these views: DBA_DATA_FILES, DBA_TABLESPACES, DBA_FREE_SPACE, DBA_SEGMENTS.

So, connect to your DB as sysdba and run query through these helpful views. For example this query can help you to find all tablespaces and their data files that objects of your user are located:

SELECT DISTINCT sgm.TABLESPACE_NAME , dtf.FILE_NAME
FROM DBA_SEGMENTS sgm
JOIN DBA_DATA_FILES dtf ON (sgm.TABLESPACE_NAME = dtf.TABLESPACE_NAME)
WHERE sgm.OWNER = 'SCOTT'

How to define an enumerated type (enum) in C?

If you declare the name for enumeration no error will occur.

If not declared, you have to use a typedef:

enum enum_name {RANDOM, IMMEDIATE, SEARCH} strategy;
strategy = IMMEDIATE;

It will not display an error...

DATEDIFF function in Oracle

We can directly subtract dates to get difference in Days.

    SET SERVEROUTPUT ON ;
    DECLARE
        V_VAR NUMBER;
    BEGIN
         V_VAR:=TO_DATE('2000-01-02', 'YYYY-MM-DD') - TO_DATE('2000-01-01', 'YYYY-MM-DD') ;
         DBMS_OUTPUT.PUT_LINE(V_VAR);
    END;

How to find patterns across multiple lines using grep?

If you have some estimation about the distance between the 2 strings 'abc' and 'efg' you are looking for, you might use:

grep -r . -e 'abc' -A num1 -B num2 | grep 'efg'

That way, the first grep will return the line with the 'abc' plus #num1 lines after it, and #num2 lines after it, and the second grep will sift through all of those to get the 'efg'. Then you'll know at which files they appear together.

How to resolve conflicts in EGit

As it's an issue we face more than often, below are the steps to resolve it.

  1. Open the Git perspective. In the Git Repository view, go to on Branches ? Local ? master and right click ? Merge...

  2. It should auto select Remote Tracking ? *origin/master. Press Merge.

  3. Launch stage view in Eclipse.

  4. Double click the files which initially showed conflict

  5. In the conflict merge view, by selecting the left arrow for all the non-conflict + conflict changes from left to right, you can resolve all the conflicts.

  6. Save the merged file.

  7. Do a Team ? pull from Eclipse again.

You are all set :)

Calling javascript function in iframe

Call

window.frames['resultFrame'].Reset();

Converting 24 hour time to 12 hour time w/ AM & PM using Javascript

For anyone reading who wants ONLY the time in the output, you can pass options to JavaScript's Date::toLocaleString() method. Example:

_x000D_
_x000D_
var date = new Date("February 04, 2011 19:00:00");_x000D_
var options = {_x000D_
  hour: 'numeric',_x000D_
  minute: 'numeric',_x000D_
  hour12: true_x000D_
};_x000D_
var timeString = date.toLocaleString('en-US', options);_x000D_
console.log(timeString);
_x000D_
_x000D_
_x000D_

timeString will be set to:

8:00 AM

Add "second: 'numeric'" to your options if you want seconds too. For all option see this.

413 Request Entity Too Large - File Upload Issue

Open file/etc/nginx/nginx.conf Add or change client_max_body_size 0;

Interface/enum listing standard mime-type constants

There is now also the class org.apache.http.entity.ContentType from package org.apache.httpcomponents.httpcore, starting from 4.2 up.

rsync - mkstemp failed: Permission denied (13)

Windows: Check permissions of destination folders. Take ownership if you must to give rights to the account running the rsync service.

Remove rows with all or some NAs (missing values) in data.frame

For your first question, I have a code that I am comfortable with to get rid of all NAs. Thanks for @Gregor to make it simpler.

final[!(rowSums(is.na(final))),]

For the second question, the code is just an alternation from the previous solution.

final[as.logical((rowSums(is.na(final))-5)),]

Notice the -5 is the number of columns in your data. This will eliminate rows with all NAs, since the rowSums adds up to 5 and they become zeroes after subtraction. This time, as.logical is necessary.

Angular no provider for NameService

Blockquote

Registering providers in a component

Here's a revised HeroesComponent that registers the HeroService in its providers array.

import { Component } from '@angular/core';

import { HeroService } from './hero.service';

@Component({
  selector: 'my-heroes',
  providers: [HeroService],
  template: `
  `
})
export class HeroesComponent { }

"Object doesn't support this property or method" error in IE11

We have set compatibility mode for IE11 to resolve an issue: Settings>Compatibility View Settings>Add your site name or Check "Display intranet sites in Compatibility View" if your portal is in the intranet.

IE version 11.0.9600.16521

Worked for us, hope this helps someone.

How to load external webpage in WebView

I used this code that was cool. but have an error. " neterr_cleartext_not_permitted" show when you use this code then you will face this problem..

I got a solution of this.you have to add this in your AndroidManifest.xml near about Application

android:usesCleartextTraffic="true"
<uses-permission android:name="android.permission.INTERNET" /> // ignore if you already added. outside of Application.

Remove Item in Dictionary based on Value

Are you trying to remove a single value or all matching values?

If you are trying to remove a single value, how do you define the value you wish to remove?

The reason you don't get a key back when querying on values is because the dictionary could contain multiple keys paired with the specified value.

If you wish to remove all matching instances of the same value, you can do this:

foreach(var item in dic.Where(kvp => kvp.Value == value).ToList())
{
    dic.Remove(item.Key);
}

And if you wish to remove the first matching instance, you can query to find the first item and just remove that:

var item = dic.First(kvp => kvp.Value == value);

dic.Remove(item.Key);

Note: The ToList() call is necessary to copy the values to a new collection. If the call is not made, the loop will be modifying the collection it is iterating over, causing an exception to be thrown on the next attempt to iterate after the first value is removed.

MySQL error #1054 - Unknown column in 'Field List'

You have an error in your OrderQuantity column. It is named "OrderQuantity" in the INSERT statement and "OrderQantity" in the table definition.

Also, I don't think you can use NOW() as default value in OrderDate. Try to use the following:

 OrderDate TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP

Example Fiddle

Namespace not recognized (even though it is there)

In my case removing/adding that assembly worked.

How can I specify the default JVM arguments for programs I run from eclipse?

Go to Window → Preferences → Java → Installed JREs. Select the JRE you're using, click Edit, and there will be a line for Default VM Arguments which will apply to every execution. For instance, I use this on OS X to hide the icon from the dock, increase max memory and turn on assertions:

-Xmx512m -ea -Djava.awt.headless=true

Why doesn't Git ignore my specified file?

What I did it to ignore the settings.php file successfully:

  1. git rm --cached sites/default/settings.php
  2. commit (up to here didn't work)
  3. manually deleted sites/default/settings.php (this did the trick)
  4. git add .
  5. commit (ignored successfully)

I think if there's the committed file on Git then ignore doesn't work as expected. Just delete the file and commit. Afterwards it'll ignore.

@UniqueConstraint and @Column(unique = true) in hibernate annotation

In addition to Boaz's answer ....

@UniqueConstraint allows you to name the constraint, while @Column(unique = true) generates a random name (e.g. UK_3u5h7y36qqa13y3mauc5xxayq).

Sometimes it can be helpful to know what table a constraint is associated with. E.g.:

@Table(
   name = "product_serial_group_mask", 
   uniqueConstraints = {
      @UniqueConstraint(
          columnNames = {"mask", "group"},
          name="uk_product_serial_group_mask"
      )
   }
)

Sharepoint: How do I filter a document library view to show the contents of a subfolder?

I don't know of any out-of-the-box way to achieve this. As you say, this is not how SharePoint lists are intended used. It might work to create a custom site column displaying the path to the document, as this might be used in a filter. Have never tried it, though.

How to make a input field readonly with JavaScript?

document.getElementById('TextBoxID').readOnly = true;    //to enable readonly


document.getElementById('TextBoxID').readOnly = false;   //to  disable readonly

How to convert hex string to Java string?

First of all read in the data, then convert it to byte array:

 byte b = Byte.parseByte(str, 16); 

and then use String constructor:

new String(byte[] bytes) 

or if the charset is not system default then:

new String(byte[] bytes, String charsetName) 

How to split a string after specific character in SQL Server and update this value to specific column

SELECT emp.LoginID, emp.JobTitle, emp.BirthDate, emp.ModifiedDate  , 
      CASE  WHEN emp.JobTitle  NOT LIKE '%Document Control%'  THEN emp.JobTitle
            ELSE SUBSTRING(emp.JobTitle,CHARINDEX('Document Control',emp.JobTitle),LEN('Document Control'))
      END 
      ,emp.gender,emp.MaritalStatus
FROM   HumanResources.Employee [emp]
WHERE  JobTitle LIKE '[C-F]%'

How to scroll up or down the page to an anchor using jQuery?

Here is the solution that worked for me. This is a generic function which works for all of the a tags referring to a named a

$("a[href^=#]").on('click', function(event) { 
    event.preventDefault(); 
    var name = $(this).attr('href'); 
    var target = $('a[name="' + name.substring(1) + '"]'); 
    $('html,body').animate({ scrollTop: $(target).offset().top }, 'slow'); 
});

Note 1: Make sure that you use double quotes " in your html. If you use single quotes, change the above part of the code to var target = $("a[name='" + name.substring(1) + "']");

Note 2: In some cases, especially when you use the sticky bar from the bootstrap, the named a will hide beneath the navigation bar. In those cases (or any similar case), you can reduce the number of the pixels from your scroll to achieve the optimal location. For example: $('html,body').animate({ scrollTop: $(target).offset().top - 15 }, 'slow'); will take you to the target with 15 pixels left on the top.

What is the email subject length limit?

after some test: If you send an email to an outlook client, and the subject is >77 chars, and it needs to use "=?ISO" inside the subject (in my case because of accents) then OutLook will "cut" the subject in the middle of it and mesh it all that comes after, including body text, attaches, etc... all a mesh!

I have several examples like this one:

Subject: =?ISO-8859-1?Q?Actas de la obra N=BA.20100154 (Expediente N=BA.20100182) "NUEVA RED FERROVIARIA.=

TRAMO=20BEASAIN=20OESTE(Pedido=20PC10/00123-125),=20BEASAIN".?=

To:

As you see, in the subject line it cutted on char 78 with a "=" followed by 2 or 3 line feeds, then continued with the rest of the subject baddly.

It was reported to me from several customers who all where using OutLook, other email clients deal with those subjects ok.

If you have no ISO on it, it doesn't hurt, but if you add it to your subject to be nice to RFC, then you get this surprise from OutLook. Bit if you don't add the ISOs, then iPhone email will not understand it(and attach files with names using such characters will not work on iPhones).

Why an abstract class implementing an interface can miss the declaration/implementation of one of the interface's methods?

Abstract classes are not required to implement the methods. So even though it implements an interface, the abstract methods of the interface can remain abstract. If you try to implement an interface in a concrete class (i.e. not abstract) and you do not implement the abstract methods the compiler will tell you: Either implement the abstract methods or declare the class as abstract.

Java ArrayList for integers

How about creating an ArrayList of a set amount of Integers?

The below method returns an ArrayList of a set amount of Integers.

public static ArrayList<Integer> createRandomList(int sizeParameter)
{
    // An ArrayList that method returns
    ArrayList<Integer> setIntegerList = new ArrayList<Integer>(sizeParameter);
    // Random Object helper
    Random randomHelper = new Random();
    
    for (int x = 0; x < sizeParameter; x++)
    {
        setIntegerList.add(randomHelper.nextInt());
    }   // End of the for loop
    
    return setIntegerList;
}

How to force reloading php.ini file?

To force a reload of the php.ini you should restart apache.

Try sudo service apache2 restart from the command line. Or sudo /etc/init.d/apache2 restart

Is there a way to force npm to generate package-lock.json?

If your npm version is lower than version 5 then install the higher version for getting the automatic generation of package-lock.json.

Example: Upgrade your current npm to version 6.14.0

npm i -g [email protected]

You could view the latest npm version list by

npm view npm versions

How to set an iframe src attribute from a variable in AngularJS

Please remove call to trustSrc function and try again like this . {{trustSrc(currentProject.url)}} to {{currentProject.url}}. Check this link http://plnkr.co/edit/caqS1jE9fpmMn5NofUve?p=preview


But according to the Angular Js 1.2 Documentation, you should write a function for getting src url. Have a look on the following code.

Before:

Javascript

scope.baseUrl = 'page';
scope.a = 1;
scope.b = 2;

Html

<!-- Are a and b properly escaped here? Is baseUrl controlled by user? -->
<iframe src="{{baseUrl}}?a={{a}&b={{b}}"

But for security reason they are recommending following method

Javascript

var baseUrl = "page";
scope.getIframeSrc = function() {

  // One should think about their particular case and sanitize accordingly
  var qs = ["a", "b"].map(function(value, name) {
      return encodeURIComponent(name) + "=" +
             encodeURIComponent(value);
    }).join("&");

  // `baseUrl` isn't exposed to a user's control, so we don't have to worry about escaping it.
  return baseUrl + "?" + qs;
};

Html

<iframe src="{{getIframeSrc()}}">

getting the index of a row in a pandas apply function

Either:

1. with row.name inside the apply(..., axis=1) call:

df = pandas.DataFrame([[1,2,3],[4,5,6]], columns=['a','b','c'], index=['x','y'])

   a  b  c
x  1  2  3
y  4  5  6

df.apply(lambda row: row.name, axis=1)

x    x
y    y

2. with iterrows() (slower)

DataFrame.iterrows() allows you to iterate over rows, and access their index:

for idx, row in df.iterrows():
    ...

java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter

Just copying the content of the zip-file to its prefered location from the zip-file will give you this error when you attempt to run the only executable that is visible in the archive. It is named similarly but it is not the real thing.

You should let the archive extract itself to make the installation complete correctly. Doing so gives you an executable named eclipse.exe with which you will not get this error.

Boolean checking in the 'if' condition

It really also depends on how you name your variable.

When people are asking "which is better practice" - this implicitly implies that both are correct, so it's just a matter of which is easier to read and maintain.

If you name your variable "status" (which is the case in your example code), I would much prefer to see

if(status == false) // if status is false

On the other hand, if you had named your variable isXXX (e.g. isReadableCode), then the former is more readable. consider:

if(!isReadable) { // if not readable
  System.out.println("I'm having a headache reading your code");
}

Path to Powershell.exe (v 2.0)

I believe it's in C:\Windows\System32\WindowsPowershell\v1.0\. In order to confuse the innocent, MS kept it in a directory labeled "v1.0". Running this on Windows 7 and checking the version number via $Host.Version (Determine installed PowerShell version) shows it's 2.0.

Another option is type $PSVersionTable at the command prompt. If you are running v2.0, the output will be:

Name                           Value
----                           -----
CLRVersion                     2.0.50727.4927
BuildVersion                   6.1.7600.16385
PSVersion                      2.0
WSManStackVersion              2.0
PSCompatibleVersions           {1.0, 2.0}
SerializationVersion           1.1.0.1
PSRemotingProtocolVersion      2.1

If you're running version 1.0, the variable doesn't exist and there will be no output.

Localization PowerShell version 1.0, 2.0, 3.0, 4.0:

  • 64 bits version: C:\Windows\System32\WindowsPowerShell\v1.0\
  • 32 bits version: C:\Windows\SysWOW64\WindowsPowerShell\v1.0\

What is the functionality of setSoTimeout and how it works?

The JavaDoc explains it very well:

With this option set to a non-zero timeout, a read() call on the InputStream associated with this Socket will block for only this amount of time. If the timeout expires, a java.net.SocketTimeoutException is raised, though the Socket is still valid. The option must be enabled prior to entering the blocking operation to have effect. The timeout must be > 0. A timeout of zero is interpreted as an infinite timeout.

SO_TIMEOUT is the timeout that a read() call will block. If the timeout is reached, a java.net.SocketTimeoutException will be thrown. If you want to block forever put this option to zero (the default value), then the read() call will block until at least 1 byte could be read.

Should I make HTML Anchors with 'name' or 'id'?

The second sample assigns a unique ID to the element in question. This element can then be manipulated or accessed using DHTML.

The first one, on the other hand, sets a named location within the document, akin to a bookmark. Attached to an "anchor", it makes perfect sense.

Powershell Get-ChildItem most recent file in directory

You could try to sort descending "sort LastWriteTime -Descending" and then "select -first 1." Not sure which one is faster

Why use #ifndef CLASS_H and #define CLASS_H in .h file but not in .cpp?

.cpp files are not included (using #include) into other files. Therefore they don't need include guarding. Main.cpp will know the names and signatures of the class that you have implemented in class.cpp only because you have specified all that in class.h - this is the purpose of a header file. (It is up to you to make sure that class.h accurately describes the code you implement in class.cpp.) The executable code in class.cpp will be made available to the executable code in main.cpp thanks to the efforts of the linker.

Split output of command by columns using Bash?

Getting the correct line (example for line no. 6) is done with head and tail and the correct word (word no. 4) can be captured with awk:

command|head -n 6|tail -n 1|awk '{print $4}'

Regex Email validation

Why not use EF6 attribute based e-mail validation?

As you can see above, Regex validation for e-mail always has some hole in it. If you are using EF6 data annotations, you can easily achieve reliable and stronger e-mail validation with EmailAddress data annotation attribute available for that. I had to remove the regex validation I used before for e-mail when I got mobile device specific regex failure on e-mail input field. When the data annotation attribute used for e-mail validation, the issue on mobile was resolved.

public class LoginViewModel
{
    [EmailAddress(ErrorMessage = "The email format is not valid")]
    public string Email{ get; set; }

Getting All Variables In Scope

Although everyone answer "No" and I know that "No" is the right answer but if you really need to get local variables of a function there is a restricted way.

Consider this function:

var f = function() {
    var x = 0;
    console.log(x);
};

You can convert your function to a string:

var s = f + '';

You will get source of function as a string

'function () {\nvar x = 0;\nconsole.log(x);\n}'

Now you can use a parser like esprima to parse function code and find local variable declarations.

var s = 'function () {\nvar x = 0;\nconsole.log(x);\n}';
s = s.slice(12); // to remove "function () "
var esprima = require('esprima');
var result = esprima.parse(s);

and find objects with:

obj.type == "VariableDeclaration"

in the result (I have removed console.log(x) below):

{
    "type": "Program",
    "body": [
        {
            "type": "VariableDeclaration",
            "declarations": [
                {
                    "type": "VariableDeclarator",
                    "id": {
                        "type": "Identifier",
                        "name": "x"
                    },
                    "init": {
                        "type": "Literal",
                        "value": 0,
                        "raw": "0"
                    }
                }
            ],
            "kind": "var"
        }
    ]
}

I have tested this in Chrome, Firefox and Node.

But the problem with this method is that you just have the variables defined in the function itself. For example for this one:

var g = function() {
    var y = 0;
    var f = function() {
        var x = 0;
        console.log(x);
    };
}

you just have access to the x and not y. But still you can use chains of caller (arguments.callee.caller.caller.caller) in a loop to find local variables of caller functions. If you have all local variable names so you have scope variables. With the variable names you have access to values with a simple eval.

how can I enable PHP Extension intl?

After installing Laminas, I got the same error message

"Translator component requires the intl PHP extension"

while wanting to view the web application with the php web server:

php -S 0.0.0.0:8080 -t public public/index.php

As I'm usgin XAMPP, in

c:\xampp\php\php.ini

I had to enable the PHP extension intl in this line ;extension=php_intl.dll, remove the starting semicolon (;) and restart XAMPP. I hope this will help.

How to display a json array in table format?

using jquery $.each you can access all data and also set in table like this

<table style="width: 100%">
     <thead>
          <tr>
               <th>Id</th>
               <th>Name</th>
               <th>Category</th>
               <th>Color</th>
           </tr>
     </thead>
     <tbody id="tbody">
     </tbody>
</table>

$.each(data, function (index, item) {
     var eachrow = "<tr>"
                 + "<td>" + item[1] + "</td>"
                 + "<td>" + item[2] + "</td>"
                 + "<td>" + item[3] + "</td>"
                 + "<td>" + item[4] + "</td>"
                 + "</tr>";
     $('#tbody').append(eachrow);
});

How to store command results in a shell variable?

The syntax to store the command output into a variable is var=$(command).

So you can directly do:

result=$(ls -l | grep -c "rahul.*patle")

And the variable $result will contain the number of matches.

What does AND 0xFF do?

it clears the all the bits that are not in the first byte

How to get rid of punctuation using NLTK tokenizer?

I think you need some sort of regular expression matching (the following code is in Python 3):

import string
import re
import nltk

s = "I can't do this now, because I'm so tired.  Please give me some time."
l = nltk.word_tokenize(s)
ll = [x for x in l if not re.fullmatch('[' + string.punctuation + ']+', x)]
print(l)
print(ll)

Output:

['I', 'ca', "n't", 'do', 'this', 'now', ',', 'because', 'I', "'m", 'so', 'tired', '.', 'Please', 'give', 'me', 'some', 'time', '.']
['I', 'ca', "n't", 'do', 'this', 'now', 'because', 'I', "'m", 'so', 'tired', 'Please', 'give', 'me', 'some', 'time']

Should work well in most cases since it removes punctuation while preserving tokens like "n't", which can't be obtained from regex tokenizers such as wordpunct_tokenize.

How to do logging in React Native?

Its so simple to get logs in React-Native

Use console.log and console.warn

console.log('character', parameter)

console.warn('character', parameter)

This log you can view in browser console. If you want to check device log or say production APK log you can use

adb logcat

adb -d logcat

How to filter data in dataview

DataView view = new DataView();
view.Table = DataSet1.Tables["Suppliers"];
view.RowFilter = "City = 'Berlin'";
view.RowStateFilter = DataViewRowState.ModifiedCurrent;
view.Sort = "CompanyName DESC";

// Simple-bind to a TextBox control
Text1.DataBindings.Add("Text", view, "CompanyName");

Ref: http://www.csharp-examples.net/dataview-rowfilter/

http://msdn.microsoft.com/en-us/library/system.data.dataview.rowfilter.aspx

How to display my location on Google Maps for Android API v2

The API Guide has it all wrong (really Google?). With Maps API v2 you do not need to enable a layer to show yourself, there is a simple call to the GoogleMaps instance you created with your map.

Google Documentation

The actual documentation that Google provides gives you your answer. You just need to

If you are using Kotlin

// map is a GoogleMap object
map.isMyLocationEnabled = true


If you are using Java

// map is a GoogleMap object
map.setMyLocationEnabled(true);

and watch the magic happen.

Just make sure that you have location permission and requested it at runtime on API Level 23 (M) or above

How to add a recyclerView inside another recyclerView

you can use LayoutInflater to inflate your dynamic data as a layout file.

UPDATE : first create a LinearLayout inside your CardView's layout and assign an ID for it. after that create a layout file that you want to inflate. at last in your onBindViewHolder method in your "RAdaper" class. write these codes :

  mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

  view = mInflater.inflate(R.layout.my_list_custom_row, parent, false);

after that you can initialize data and ClickListeners with your RAdapter Data. hope it helps.

this and this may useful :)

How can I write output from a unit test?

Try using:

Console.WriteLine()

The call to Debug.WriteLine will only be made during when DEBUG is defined.

Other suggestions are to use: Trace.WriteLine as well, but I haven't tried this.

There is also an option (not sure if Visual Studio 2008 has it), but you can still Use Debug.WriteLine when you run the test with Test With Debuggeroption in the IDE.

Splitting string with pipe character ("|")

split takes regex as a parameter.| has special meaning in regex.. use \\| instead of | to escape it.

vba pass a group of cells as range to function

There is another way to pass multiple ranges to a function, which I think feels much cleaner for the user. When you call your function in the spreadsheet you wrap each set of ranges in brackets, for example: calculateIt( (A1,A3), (B6,B9) )

The above call assumes your two Sessions are in A1 and A3, and your two Customers are in B6 and B9.

To make this work, your function needs to loop through each of the Areas in the input ranges. For example:

Function calculateIt(Sessions As Range, Customers As Range) As Single

    ' check we passed the same number of areas
    If (Sessions.Areas.Count <> Customers.Areas.Count) Then
        calculateIt = CVErr(xlErrNA)
        Exit Function
    End If

    Dim mySession, myCustomers As Range

    ' run through each area and calculate
    For a = 1 To Sessions.Areas.Count

        Set mySession = Sessions.Areas(a)
        Set myCustomers = Customers.Areas(a)

        ' calculate them...
    Next a

End Function

The nice thing is, if you have both your inputs as a contiguous range, you can call this function just as you would a normal one, e.g. calculateIt(A1:A3, B6:B9).

Hope that helps :)

SQL Server stored procedure creating temp table and inserting value

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

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

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

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

Return multiple values to a method caller

No, you can't return multiple values from a function in C# (for versions lower than C# 7), at least not in the way you can do it in Python.

However, there are a couple alternatives:

You can return an array of type object with the multiple values you want in it.

private object[] DoSomething()
{
    return new [] { 'value1', 'value2', 3 };
}

You can use out parameters.

private string DoSomething(out string outparam1, out int outparam2)
{
    outparam1 = 'value2';
    outparam2 = 3;
    return 'value1';
}

How to return a 200 HTTP Status Code from ASP.NET MVC 3 controller

200 is just the normal HTTP header for a successful request. If that's all you need, just have the controller return new EmptyResult();

Are these methods thread safe?

The only problem with threads is accessing the same object from different threads without synchronization.

If each function only uses parameters for reading and local variables, they don't need any synchronization to be thread-safe.

How to change legend size with matplotlib.pyplot

plot.legend(loc = 'lower right', decimal_places = 2, fontsize = '11', title = 'Hey there', title_fontsize = '20')

What are the retransmission rules for TCP?

What exactly are the rules for requesting retransmission of lost data?

The receiver does not request the retransmission. The sender waits for an ACK for the byte-range sent to the client and when not received, resends the packets, after a particular interval. This is ARQ (Automatic Repeat reQuest). There are several ways in which this is implemented.

Stop-and-wait ARQ
Go-Back-N ARQ
Selective Repeat ARQ

are detailed in the RFC 3366.

At what time frequency are the retransmission requests performed?

The retransmissions-times and the number of attempts isn't enforced by the standard. It is implemented differently by different operating systems, but the methodology is fixed. (One of the ways to fingerprint OSs perhaps?)

The timeouts are measured in terms of the RTT (Round Trip Time) times. But this isn't needed very often due to Fast-retransmit which kicks in when 3 Duplicate ACKs are received.

Is there an upper bound on the number?

Yes there is. After a certain number of retries, the host is considered to be "down" and the sender gives up and tears down the TCP connection.

Is there functionality for the client to indicate to the server to forget about the whole TCP segment for which part went missing when the IP packet went missing?

The whole point is reliable communication. If you wanted the client to forget about some part, you wouldn't be using TCP in the first place. (UDP perhaps?)

How to create enum like type in TypeScript?

TypeScript 0.9+ has a specification for enums:

enum AnimationType {
    BOUNCE,
    DROP,
}

The final comma is optional.

Difference between ref and out parameters in .NET

Example for OUT : Variable gets value initialized after going into the method. Later the same value is returned to the main method.

namespace outreftry
{
    class outref
    {
        static void Main(string[] args)
        {
            yyy a = new yyy(); ;

            // u can try giving int i=100 but is useless as that value is not passed into
            // the method. Only variable goes into the method and gets changed its
            // value and comes out. 
            int i; 

            a.abc(out i);

            System.Console.WriteLine(i);
        }
    }
    class yyy
    {

        public void abc(out int i)
        {

            i = 10;

        }

    }
}

Output:

10

===============================================

Example for Ref : Variable should be initialized before going into the method. Later same value or modified value will be returned to the main method.

namespace outreftry
{
    class outref
    {
        static void Main(string[] args)
        {
            yyy a = new yyy(); ;

            int i = 0;

            a.abc(ref i);

            System.Console.WriteLine(i);
        }
    }
    class yyy
    {

        public void abc(ref int i)
        {
            System.Console.WriteLine(i);
            i = 10;

        }

    }
}

Output:

    0
    10

=================================

Hope its clear now.

Iterate through pairs of items in a Python list

>>> a = [5, 7, 11, 4, 5]
>>> for n,k in enumerate(a[:-1]):
...     print a[n],a[n+1]
...
5 7
7 11
11 4
4 5

How to use default Android drawables

If you read through any of the discussions on the android development group you will see that they discourage the use of anything that isn't in the public SDK because the rest is subject to extensive change.

How to wait for async method to complete?

just put Wait() to wait until task completed

GetInputReportViaInterruptTransfer().Wait();

Encode/Decode URLs in C++

I faced the encoding half of this problem the other day. Unhappy with the available options, and after taking a look at this C sample code, i decided to roll my own C++ url-encode function:

#include <cctype>
#include <iomanip>
#include <sstream>
#include <string>

using namespace std;

string url_encode(const string &value) {
    ostringstream escaped;
    escaped.fill('0');
    escaped << hex;

    for (string::const_iterator i = value.begin(), n = value.end(); i != n; ++i) {
        string::value_type c = (*i);

        // Keep alphanumeric and other accepted characters intact
        if (isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~') {
            escaped << c;
            continue;
        }

        // Any other characters are percent-encoded
        escaped << uppercase;
        escaped << '%' << setw(2) << int((unsigned char) c);
        escaped << nouppercase;
    }

    return escaped.str();
}

The implementation of the decode function is left as an exercise to the reader. :P

How to view transaction logs in SQL Server 2008

You could use the undocumented

DBCC LOG(databasename, typeofoutput)

where typeofoutput:

0: Return only the minimum of information for each operation -- the operation, its context and the transaction ID. (Default)
1: As 0, but also retrieve any flags and the log record length.
2: As 1, but also retrieve the object name, index name, page ID and slot ID.
3: Full informational dump of each operation.
4: As 3 but includes a hex dump of the current transaction log row.

For example, DBCC LOG(database, 1)

You could also try fn_dblog.

For rolling back a transaction using the transaction log I would take a look at Stack Overflow post Rollback transaction using transaction log.

JavaScript style.display="none" or jQuery .hide() is more efficient?

Efficiency isn't going to matter for something like this in 99.999999% of situations. Do whatever is easier to read and or maintain.

In my apps I usually rely on classes to provide hiding and showing, for example .addClass('isHidden')/.removeClass('isHidden') which would allow me to animate things with CSS3 if I wanted to. It provides more flexibility.

How to set editor theme in IntelliJ Idea

For IntelliJ in Mac

View -> Quick Switch theme (^`)-> color schema

What is the equivalent of the C++ Pair<L,R> in Java?

com.sun.tools.javac.util.Pair is an simple implementation of a pair. It can be found in jdk1.7.0_51\lib\tools.jar.

Other than the org.apache.commons.lang3.tuple.Pair, it's not just an interface.

FlutterError: Unable to load asset

My issue was nested folders.

I had my image in assets/images/logo/xyz.png and thought that - assets/images/ would catch all subfolders.

You have to explicitly add each nested subfolder

Solution: - assets/images/logo/ etc.

CSS Image size, how to fill, but not stretch?

This will Fill images to a specific size, without stretching it or without cropping it

img{
    width:150px;  //your requirement size
    height:100px; //your requirement size

/*Scale down will take the necessary specified space that is 150px x 100px without stretching the image*/
    object-fit:scale-down;
}

Math.random() explanation

int randomWithRange(int min, int max)
{
   int range = (max - min) + 1;     
   return (int)(Math.random() * range) + min;
}

Output of randomWithRange(2, 5) 10 times:

5
2
3
3
2
4
4
4
5
4

The bounds are inclusive, ie [2,5], and min must be less than max in the above example.

EDIT: If someone was going to try and be stupid and reverse min and max, you could change the code to:

int randomWithRange(int min, int max)
{
   int range = Math.abs(max - min) + 1;     
   return (int)(Math.random() * range) + (min <= max ? min : max);
}

EDIT2: For your question about doubles, it's just:

double randomWithRange(double min, double max)
{
   double range = (max - min);     
   return (Math.random() * range) + min;
}

And again if you want to idiot-proof it it's just:

double randomWithRange(double min, double max)
{
   double range = Math.abs(max - min);     
   return (Math.random() * range) + (min <= max ? min : max);
}

How to tag docker image with docker-compose

It seems the docs/tool have been updated and you can now add the image tag to your script. This was successful for me.

Example:

version: '2'
services:

  baggins.api.rest:
    image: my.image.name:rc2
    build:
      context: ../..
      dockerfile: app/Docker/Dockerfile.release
    ports:
      ...

https://docs.docker.com/compose/compose-file/#build

How do we download a blob url video

If you can NOT find the .m3u8 file you will need to do a couple of steps different.

1) Go to the network tab and sort by Media

Sort by media

2) You will see something here and select the first item. In my example, it's an mpd file. then copy the Request URL.

3) Next, download the file using your favorite command line tool using the URL from step 2.

youtube-dl -f bestvideo+bestaudio https://url.com/destination/stream.mpd

4) Depending on the encoding you might have to join the audio and video files together but this will depend on a video by video case.

Move the mouse pointer to a specific position?

You can't move the mouse pointer using javascript, and thus for obvious security reasons. The best way to achieve this effect would be to actually place the control under the mouse pointer.

How to set placeholder value using CSS?

Some type of input hasn't got the :after or :before pseudo-element, so you can use a background-image with an SVG text element:

    input {
       background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' version='1.1' height='50px' width='120px'><text x='0' y='15' fill='gray' font-size='15'>Type Something...</text></svg>");
       background-repeat: no-repeat;
    }

    input:focus {
       background-image: none;
    }

My codepen: https://codepen.io/Scario/pen/BaagbeZ

Getting a slice of keys from a map

Visit https://play.golang.org/p/dx6PTtuBXQW

package main

import (
    "fmt"
    "sort"
)

func main() {
    mapEg := map[string]string{"c":"a","a":"c","b":"b"}
    keys := make([]string, 0, len(mapEg))
    for k := range mapEg {
        keys = append(keys, k)
    }
    sort.Strings(keys)
    fmt.Println(keys)
}

Can I fade in a background image (CSS: background-image) with jQuery?

This is what worked for my, and its pure css


css

html {
    padding: 0;
    margin: 0;
    width: 100%;
    height: 100%;
  }

  body {
    padding: 0;
    margin: 0;
    width: 100%;
    height: 100%;
  }

  #bg {
    width: 100%;
    height: 100%;
    background: url('/image.jpg/') no-repeat center center fixed;

    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;

    -webkit-animation: myfirst 5s ; /* Chrome, Safari, Opera */
    animation: myfirst 5s ;
  }

  /* Chrome, Safari, Opera */
  @-webkit-keyframes myfirst {
    from {opacity: 0.2;}
    to {opacity: 1;}
  }

  /* Standard syntax */
  @keyframes myfirst {
    from {opacity: 0.2;}
    to {opacity: 1;}
  }

html

<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
  <div id="bg">
    <!-- content here -->
  </div> <!-- end bg -->
</body>
</html>

Use child_process.execSync but keep output in console

Unless you redirect stdout and stderr as the accepted answer suggests, this is not possible with execSync or spawnSync. Without redirecting stdout and stderr those commands only return stdout and stderr when the command is completed.

To do this without redirecting stdout and stderr, you are going to need to use spawn to do this but it's pretty straight forward:

var spawn = require('child_process').spawn;

//kick off process of listing files
var child = spawn('ls', ['-l', '/']);

//spit stdout to screen
child.stdout.on('data', function (data) {   process.stdout.write(data.toString());  });

//spit stderr to screen
child.stderr.on('data', function (data) {   process.stdout.write(data.toString());  });

child.on('close', function (code) { 
    console.log("Finished with code " + code);
});

I used an ls command that recursively lists files so that you can test it quickly. Spawn takes as first argument the executable name you are trying to run and as it's second argument it takes an array of strings representing each parameter you want to pass to that executable.

However, if you are set on using execSync and can't redirect stdout or stderr for some reason, you can open up another terminal like xterm and pass it a command like so:

var execSync = require('child_process').execSync;

execSync("xterm -title RecursiveFileListing -e ls -latkR /");

This will allow you to see what your command is doing in the new terminal but still have the synchronous call.

How do you access the element HTML from within an Angular attribute directive?

I suggest using Render, as the ElementRef API doc suggests:

... take a look at Renderer which provides API that can safely be used even when direct access to native elements is not supported. Relying on direct DOM access creates tight coupling between your application and rendering layers which will make it impossible to separate the two and deploy your application into a web worker or Universal.

Always use the Renderer for it will make you code (or library you right) be able to work when using Universal or WebWorkers.

import { Directive, ElementRef, HostListener, Input, Renderer } from '@angular/core';

export class HighlightDirective {
    constructor(el: ElementRef, renderer: Renderer) {
        renderer.setElementProperty(el.nativeElement, 'innerHTML', 'some new value');
    }
}

It doesn't look like Render has a getElementProperty() method though, so I guess we still need to use NativeElement for that part. Or (better) pass the content in as an input property to the directive.

Why does python use 'else' after for and while loops?

I read it like "When the iterable is exhausted completely, and the execution is about to proceed to the next statement after finishing the for, the else clause will be executed." Thus, when the iteration is broken by break, this will not be executed.

How to make a Python script run like a service or daemon in Linux

You have two options here.

  1. Make a proper cron job that calls your script. Cron is a common name for a GNU/Linux daemon that periodically launches scripts according to a schedule you set. You add your script into a crontab or place a symlink to it into a special directory and the daemon handles the job of launching it in the background. You can read more at Wikipedia. There is a variety of different cron daemons, but your GNU/Linux system should have it already installed.

  2. Use some kind of python approach (a library, for example) for your script to be able to daemonize itself. Yes, it will require a simple event loop (where your events are timer triggering, possibly, provided by sleep function).

I wouldn't recommend you to choose 2., because you would be, in fact, repeating cron functionality. The Linux system paradigm is to let multiple simple tools interact and solve your problems. Unless there are additional reasons why you should make a daemon (in addition to trigger periodically), choose the other approach.

Also, if you use daemonize with a loop and a crash happens, no one will check the mail after that (as pointed out by Ivan Nevostruev in comments to this answer). While if the script is added as a cron job, it will just trigger again.

Web scraping with Java

HTMLUnit can be used to do web scraping, it supports invoking pages, filling & submitting forms. I have used this in my project. It is good java library for web scraping. read here for more

My kubernetes pods keep crashing with "CrashLoopBackOff" but I can't find any log

From This page, the container dies after running everything correctly but crashes because all the commands ended. Either you make your services run on the foreground, or you create a keep alive script. By doing so, Kubernetes will show that your application is running. We have to note that in the Docker environment, this problem is not encountered. It is only Kubernetes that wants a running app.

Update (an example):

Here's how to avoid CrashLoopBackOff, when launching a Netshoot container:

kubectl run netshoot --image nicolaka/netshoot -- sleep infinity

Which is the best library for XML parsing in java

VTD-XML is the heavy duty XML parsing lib... it is better than others in virtually every way... here is a 2013 paper that analyzes all XML processing frameworks available in java platform...

http://sdiwc.us/digitlib/journal_paper.php?paper=00000582.pdf

subsampling every nth entry in a numpy array

You can use numpy's slicing, simply start:stop:step.

>>> xs
array([1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4])
>>> xs[1::4]
array([2, 2, 2])

This creates a view of the the original data, so it's constant time. It'll also reflect changes to the original array and keep the whole original array in memory:

>>> a
array([1, 2, 3, 4, 5])
>>> b = a[::2]         # O(1), constant time
>>> b[:] = 0           # modifying the view changes original array
>>> a                  # original array is modified
array([0, 2, 0, 4, 0])

so if either of the above things are a problem, you can make a copy explicitly:

>>> a
array([1, 2, 3, 4, 5])
>>> b = a[::2].copy()  # explicit copy, O(n)
>>> b[:] = 0           # modifying the copy
>>> a                  # original is intact
array([1, 2, 3, 4, 5])

This isn't constant time, but the result isn't tied to the original array. The copy also contiguous in memory, which can make some operations on it faster.

How to iterate over the file in python

The traceback indicates that probably you have an empty line at the end of the file. You can fix it like this:

f = open('test.txt','r')
g = open('test1.txt','w') 
while True:
    x = f.readline()
    x = x.rstrip()
    if not x: break
    print >> g, int(x, 16)

On the other hand it would be better to use for x in f instead of readline. Do not forget to close your files or better to use with that close them for you:

with open('test.txt','r') as f:
    with open('test1.txt','w') as g: 
        for x in f:
            x = x.rstrip()
            if not x: continue
            print >> g, int(x, 16)

How do I clear this setInterval inside a function?

// Initiate set interval and assign it to intervalListener
var intervalListener = self.setInterval(function () {someProcess()}, 1000);
function someProcess() {
  console.log('someProcess() has been called');
  // If some condition is true clear the interval
  if (stopIntervalIsTrue) {
    window.clearInterval(intervalListener);
  }
}

Twitter bootstrap remote modal shows same content every time

This one works for me:

modal

<div class="modal fade" id="searchKaryawan" tabindex="-1" role="dialog" aria-labelledby="SearchKaryawanLabel" aria-hidden="true"> <div class="modal-dialog">
<div class="modal-content">
  <div class="modal-header">
    <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
    <h4 class="modal-title" id="SearchKaryawanLabel">Cari Karyawan</h4>
  </div>
  <div class="modal-body">
    <input type="hidden" name="location">
    <input name="cariNama" type="text" class="form-control" onkeyup="if (this.value.length > 3) cariNikNama();" />
    <div class="links-area" id="links-area"></div>
  </div>
  <div class="modal-footer">
  </div>
</div> </div></div>

script

<script type="text/javascript">$('body').on('hidden.bs.modal', '.modal', function () {  $(".links-area").empty() }); </script>

links-area is area where i put the data and need to clear

Python: avoiding pylint warnings about too many arguments

I came across the same nagging error, which I realized has something to do with a cool feature PyCharm automatically detects...just add the @staticmethod decorator, and it will automatically remove that error where the method is used

get size of json object

try this

$.parseJSON(data).length

java.io.StreamCorruptedException: invalid stream header: 54657374

Clearly you aren't sending the data with ObjectOutputStream: you are just writing the bytes.

  • If you read with readObject() you must write with writeObject().
  • If you read with readUTF() you must write with writeUTF().
  • If you read with readXXX() you must write with writeXXX(), for most values of XXX.

Regarding Java switch statements - using return and omitting breaks in each case

Best case for human logic to computer generated bytecode would be to utilize code like the following:

private double translateSlider(int sliderVal) {
  float retval = 1.0;

  switch (sliderVal) {
    case 1: retval = 0.9; break;
    case 2: retval = 0.8; break;
    case 3: retval = 0.7; break;
    case 4: retval = 0.6; break;
    case 0:
    default: break;
  }
  return retval;
}

Thus eliminating multiple exits from the method and utilizing the language logically. (ie while sliderVal is an integer range of 1-4 change float value else if sliderVal is 0 and all other values, retval stays the same float value of 1.0)

However something like this with each integer value of sliderVal being (n-(n/10)) one really could just do a lambda and get a faster results:

private double translateSlider = (int sliderVal) -> (1.0-(siderVal/10));

Edit: A modulus of 4 may be in order to keep logic (ie (n-(n/10))%4))

Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize

-XX:MaxPermSize=size

Sets the maximum permanent generation space size (in bytes). This option was deprecated in JDK 8, and superseded by the -XX:MaxMetaspaceSize option.

-XX:PermSize=size

Sets the space (in bytes) allocated to the permanent generation that triggers a garbage collection if it is exceeded. This option was deprecated in JDK 8, and superseded by the -XX:MetaspaceSize option.

How to change an input button image using CSS?

You can use blank.gif (1px transparent image) as target in your tag

<input type="image" src="img/blank.gif" class="button"> 

and then style background in css:

.button {border:0;background:transparent url("../img/button.png") no-repeat 0 0;}
.button:hover {background:transparent url("../img/button-hover.png") no-repeat 0 0;}

Elasticsearch difference between MUST and SHOULD bool query

As said in the documentation:

Must: The clause (query) must appear in matching documents.

Should: The clause (query) should appear in the matching document. In a boolean query with no must clauses, one or more should clauses must match a document. The minimum number of should clauses to match can be set using the minimum_should_match parameter.

In other words, results will have to be matched by all the queries present in the must clause ( or match at least one of the should clauses if there is no must clause.

Since you want your results to satisfy all the queries, you should use must.


You can indeed use filters inside a boolean query.

entity framework Unable to load the specified metadata resource

Craig Stuntz has written an extensive (in my opinion) blog post on troubleshooting this exact error message, I personally would start there.

The following res: (resource) references need to point to your model.

<add name="Entities" connectionString="metadata=
    res://*/Models.WraithNath.co.uk.csdl|
    res://*/Models.WraithNath.co.uk.ssdl|
    res://*/Models.WraithNath.co.uk.msl;

Make sure each one has the name of your .edmx file after the "*/", with the "edmx" changed to the extension for that res (.csdl, .ssdl, or .msl).

It also may help to specify the assembly rather than using "//*/".

Worst case, you can check everything (a bit slower but should always find the resource) by using

<add name="Entities" connectionString="metadata=
        res://*/;provider= <!-- ... -->

User Control - Custom Properties

You do this via attributes on the properties, like this:

[Description("Test text displayed in the textbox"),Category("Data")] 
public string Text {
  get => myInnerTextBox.Text;
  set => myInnerTextBox.Text = value;
}

The category is the heading under which the property will appear in the Visual Studio Properties box. Here's a more complete MSDN reference, including a list of categories.

Linker Command failed with exit code 1 (use -v to see invocation), Xcode 8, Swift 3

the only thing that worked for me was to run pod deintegrate and pod install

Import and insert sql.gz file into database with putty

Creating a Dump File SQL.gz on the current server

$ sudo apt-get install pigz pv

$ pv | mysqldump --user=<yourdbuser> --password=<yourdbpassword> <currentexistingdbname> --single-transaction --routines --triggers --events --quick --opt -Q --flush-logs --allow-keywords --hex-blob --order-by-primary --skip-comments --skip-disable-keys --skip-add-locks --extended-insert --log-error=/var/log/mysql/<dbname>_backup.log | pigz > /path/to/folder/<dbname>_`date +\%Y\%m\%d_\%H\%M`.sql.gz

Optional: Command Arguments for connection

--host=127.0.0.1 / localhost / IP Address of the Dump Server
--port=3306

Importing the dumpfile created above to a different Server

$ sudo apt-get install pigz pv

$ zcat /path/to/folder/<dbname>_`date +\%Y\%m\%d_\%H\%M`.sql.gz | pv | mysql --user=<yourdbuser> --password=<yourdbpassword> --database=<yournewdatabasename> --compress --reconnect --unbuffered --net_buffer_length=1048576 --max_allowed_packet=1073741824 --connect_timeout=36000 --line-numbers --wait --init-command="SET GLOBAL net_buffer_length=1048576;SET GLOBAL max_allowed_packet=1073741824;SET FOREIGN_KEY_CHECKS=0;SET UNIQUE_CHECKS = 0;SET AUTOCOMMIT = 1;FLUSH NO_WRITE_TO_BINLOG QUERY CACHE, STATUS, SLOW LOGS, GENERAL LOGS, ERROR LOGS, ENGINE LOGS, BINARY LOGS, LOGS;"

Optional: Command Arguments for connection

--host=127.0.0.1 / localhost / IP Address of the Import Server
--port=3306

mysql: [Warning] Using a password on the command line interface can be insecure. 1.0GiB 00:06:51 [8.05MiB/s] [<=> ]

The optional software packages are helpful to import your database SQL file faster

  • with a progress view (pv)
  • Parallel gzip (pigz/unpigz) to gzip/gunzip files in parallel

for faster zipping of the output

Mocking a function to raise an Exception to test an except block

Your mock is raising the exception just fine, but the error.resp.status value is missing. Rather than use return_value, just tell Mock that status is an attribute:

barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')

Additional keyword arguments to Mock() are set as attributes on the resulting object.

I put your foo and bar definitions in a my_tests module, added in the HttpError class so I could use it too, and your test then can be ran to success:

>>> from my_tests import foo, HttpError
>>> import mock
>>> with mock.patch('my_tests.bar') as barMock:
...     barMock.side_effect = HttpError(mock.Mock(status=404), 'not found')
...     result = my_test.foo()
... 
404 - 
>>> result is None
True

You can even see the print '404 - %s' % error.message line run, but I think you wanted to use error.content there instead; that's the attribute HttpError() sets from the second argument, at any rate.

Control cannot fall through from one case label

You need to break;, throw, goto, or return from each of your case labels. In a loop you may also continue.

        switch (searchType)
        {
            case "SearchBooks":
                Selenium.Type("//*[@id='SearchBooks_TextInput']", searchText);
                Selenium.Click("//*[@id='SearchBooks_SearchBtn']");
                break;

            case "SearchAuthors":
                Selenium.Type("//*[@id='SearchAuthors_TextInput']", searchText);
                Selenium.Click("//*[@id='SearchAuthors_SearchBtn']");
                break;
        }

The only time this isn't true is when the case labels are stacked like this:

 case "SearchBooks": // no code inbetween case labels.
 case "SearchAuthors":
    // handle both of these cases the same way.
    break;

Android: how to make keyboard enter button say "Search" and handle its click?

by XML:

 <EditText
        android:id="@+id/search_edit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/search"
        android:imeOptions="actionSearch"
        android:inputType="text" />

By Java:

 editText.clearFocus();
    InputMethodManager in = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    in.hideSoftInputFromWindow(searchEditText.getWindowToken(), 0);

When to use Task.Delay, when to use Thread.Sleep?

My opinion,

Task.Delay() is asynchronous. It doesn't block the current thread. You can still do other operations within current thread. It returns a Task return type (Thread.Sleep() doesn't return anything ). You can check if this task is completed(use Task.IsCompleted property) later after another time-consuming process.

Thread.Sleep() doesn't have a return type. It's synchronous. In the thread, you can't really do anything other than waiting for the delay to finish.

As for real-life usage, I have been programming for 15 years. I have never used Thread.Sleep() in production code. I couldn't find any use case for it. Maybe that's because I mostly do web application development.

Request UAC elevation from within a Python script?

The following example builds on MARTIN DE LA FUENTE SAAVEDRA's excellent work and accepted answer. In particular, two enumerations are introduced. The first allows for easy specification of how an elevated program is to be opened, and the second helps when errors need to be easily identified. Please note that if you want all command line arguments passed to the new process, sys.argv[0] should probably be replaced with a function call: subprocess.list2cmdline(sys.argv).

#! /usr/bin/env python3
import ctypes
import enum
import subprocess
import sys

# Reference:
# msdn.microsoft.com/en-us/library/windows/desktop/bb762153(v=vs.85).aspx


# noinspection SpellCheckingInspection
class SW(enum.IntEnum):
    HIDE = 0
    MAXIMIZE = 3
    MINIMIZE = 6
    RESTORE = 9
    SHOW = 5
    SHOWDEFAULT = 10
    SHOWMAXIMIZED = 3
    SHOWMINIMIZED = 2
    SHOWMINNOACTIVE = 7
    SHOWNA = 8
    SHOWNOACTIVATE = 4
    SHOWNORMAL = 1


class ERROR(enum.IntEnum):
    ZERO = 0
    FILE_NOT_FOUND = 2
    PATH_NOT_FOUND = 3
    BAD_FORMAT = 11
    ACCESS_DENIED = 5
    ASSOC_INCOMPLETE = 27
    DDE_BUSY = 30
    DDE_FAIL = 29
    DDE_TIMEOUT = 28
    DLL_NOT_FOUND = 32
    NO_ASSOC = 31
    OOM = 8
    SHARE = 26


def bootstrap():
    if ctypes.windll.shell32.IsUserAnAdmin():
        main()
    else:
       # noinspection SpellCheckingInspection
        hinstance = ctypes.windll.shell32.ShellExecuteW(
            None,
            'runas',
            sys.executable,
            subprocess.list2cmdline(sys.argv),
            None,
            SW.SHOWNORMAL
        )
        if hinstance <= 32:
            raise RuntimeError(ERROR(hinstance))


def main():
    # Your Code Here
    print(input('Echo: '))


if __name__ == '__main__':
    bootstrap()

AngularJS: how to enable $locationProvider.html5Mode with deeplinking

This was the best solution I found after more time than I care to admit. Basically, add target="_self" to each link that you need to insure a page reload.

http://blog.panjiesw.com/posts/2013/09/angularjs-normal-links-with-html5mode/

How can I exclude all "permission denied" messages from "find"?

Use:

find . 2>/dev/null > files_and_folders

This hides not just the Permission denied errors, of course, but all error messages.

If you really want to keep other possible errors, such as too many hops on a symlink, but not the permission denied ones, then you'd probably have to take a flying guess that you don't have many files called 'permission denied' and try:

find . 2>&1 | grep -v 'Permission denied' > files_and_folders

If you strictly want to filter just standard error, you can use the more elaborate construction:

find . 2>&1 > files_and_folders | grep -v 'Permission denied' >&2

The I/O redirection on the find command is: 2>&1 > files_and_folders |. The pipe redirects standard output to the grep command and is applied first. The 2>&1 sends standard error to the same place as standard output (the pipe). The > files_and_folders sends standard output (but not standard error) to a file. The net result is that messages written to standard error are sent down the pipe and the regular output of find is written to the file. The grep filters the standard output (you can decide how selective you want it to be, and may have to change the spelling depending on locale and O/S) and the final >&2 means that the surviving error messages (written to standard output) go to standard error once more. The final redirection could be regarded as optional at the terminal, but would be a very good idea to use it in a script so that error messages appear on standard error.

There are endless variations on this theme, depending on what you want to do. This will work on any variant of Unix with any Bourne shell derivative (Bash, Korn, …) and any POSIX-compliant version of find.

If you wish to adapt to the specific version of find you have on your system, there may be alternative options available. GNU find in particular has a myriad options not available in other versions — see the currently accepted answer for one such set of options.

How to prevent Browser cache on Angular 2 site?

A combination of @Jack's answer and @ranierbit's answer should do the trick.

Set the ng build flag for --output-hashing so:

ng build --output-hashing=all

Then add this class either in a service or in your app.module

@Injectable()
export class NoCacheHeadersInterceptor implements HttpInterceptor {
    intercept(req: HttpRequest<any>, next: HttpHandler) {
        const authReq = req.clone({
            setHeaders: {
                'Cache-Control': 'no-cache',
                 Pragma: 'no-cache'
            }
        });
        return next.handle(authReq);    
    }
}

Then add this to your providers in your app.module:

providers: [
  ... // other providers
  {
    provide: HTTP_INTERCEPTORS,
    useClass: NoCacheHeadersInterceptor,
    multi: true
  },
  ... // other providers
]

This should prevent caching issues on live sites for client machines

Design Android EditText to show error message as described by google

reVerse's answer is great but it didn't point out how to remove the floating error tooltip kind of thing

You'll need edittext.setError(null) to remove that.
Also, as someone pointed out, you don't need TextInputLayout.setErrorEnabled(true)

Layout

<android.support.design.widget.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <EditText
        android:id="@+id/edittext"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Enter something" />
</android.support.design.widget.TextInputLayout>

Code

TextInputLayout til = (TextInputLayout) editText.getParent();
til.setError("Your input is not valid...");
editText.setError(null);

multi line comment vb.net in Visual studio 2010

The only way I could do it in VS 2010 IDE was to highlight the block of code and hit ctrl-E and then C

Auto refresh code in HTML using meta tags

Try this:

<meta http-equiv="refresh" content="5;URL= your url">

or

<meta http-equiv="refresh" content="5">