Programs & Examples On #Tivo

TiVo is a digital video recorder (DVR) developed and marketed by TiVo, Inc. and introduced in 1999. TiVo provides an on-screen guide of scheduled broadcast programming television programs.

How to format a java.sql.Timestamp(yyyy-MM-dd HH:mm:ss.S) to a date(yyyy-MM-dd HH:mm:ss)

A date-time object is not a String

The java.sql.Timestamp class has no format. Its toString method generates a String with a format.

Do not conflate a date-time object with a String that may represent its value. A date-time object can parse strings and generate strings but is not itself a string.

java.time

First convert from the troubled old legacy date-time classes to java.time classes. Use the new methods added to the old classes.

Instant instant = mySqlDate.toInstant() ;

Lose the fraction of a second you don't want.

instant = instant.truncatedTo( ChronoUnit.Seconds );

Assign the time zone to adjust from UTC used by Instant.

ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = instant.atZone( z );

Generate a String close to your desired output. Replace its T in the middle with a SPACE.

DateTimeFormatter f = DateTimeFormatter.ISO_LOCAL_DATE_TIME ;
String output = zdt.format( f ).replace( "T" , " " );

Remove credentials from Git

  1. Go to C:\Users\<current-user>
  2. check for .git-credentials file
  3. Delete content or modify as per your requirement
  4. Restart your terminal

error code 1292 incorrect date value mysql

Insert date in the following format yyyy-MM-dd example,

INSERT INTO `PROGETTO`.`ALBERGO`(`ID`, `nome`, `viale`, `num_civico`, `data_apertura`, `data_chiusura`, `orario_apertura`, `orario_chiusura`, `posti_liberi`, `costo_intero`, `costo_ridotto`, `stelle`, `telefono`, `mail`, `web`, `Nome-paese`, `Comune`) 
VALUES(0, 'Hotel Centrale', 'Via Passo Rolle', '74', '2012-05-01', '2012-09-31', '06:30', '24:00', 80, 50, 25, 3, '43968083', '[email protected]', 'http://www.hcentrale.it/', 'Trento', 'TN')

java.io.IOException: Server returned HTTP response code: 500

This Status Code 500 is an Internal Server Error. This code indicates that a part of the server (for example, a CGI program) has crashed or encountered a configuration error.

i think the problem does'nt lie on your side, but rather on the side of the Http server. the resources you used to access may have been moved or get corrupted, or its configuration just may have altered or spoiled

Convert js Array() to JSon object for use with JQuery .ajax

You can iterate the key/value pairs of the saveData object to build an array of the pairs, then use join("&") on the resulting array:

var a = [];
for (key in saveData) {
    a.push(key+"="+saveData[key]);
}
var serialized = a.join("&") // a=2&c=1

Get clicked element using jQuery on event?

A simple way is to pass the data attribute to your HTML tag.

Example:

<div data-id='tagid' class="clickElem"></div>

<script>
$(document).on("click",".appDetails", function () {
   var clickedBtnID = $(this).attr('data');
   alert('you clicked on button #' + clickedBtnID);
});
</script>

Getting the count of unique values in a column in bash

Here is a way to do it in the shell:

FIELD=2
cut -f $FIELD * | sort| uniq -c |sort -nr

This is the sort of thing bash is great at.

how to configuring a xampp web server for different root directory

In case, if anyone prefers a simpler solution, especially on Linux (e.g. Ubuntu), a very easy way out is to create a symbolic link to the intended folder in the htdocs folder. For example, if I want to be able to serve files from a folder called "/home/some/projects/testserver/" and my htdocs is located in "/opt/lampp/htdocs/". Just create a symbolic link like so:

ln -s /home/some/projects/testserver /opt/lampp/htdocs/testserver

The command for symbolic link works like so: ln -s target source where,

target - The existing file/directory you would like to link TO.
source - The file/folder to be created, copying the contents of the target. The LINK itself.

For more help see ln --help Source: Create Symbolic Links in Ubuntu

And that's done. just visit http://localhost/testserver/ In fact, you don't even need to restart your server.

How can I get nth element from a list?

Look here, the operator used is !!.

I.e. [1,2,3]!!1 gives you 2, since lists are 0-indexed.

Best way to test if a row exists in a MySQL table

You could also try EXISTS:

SELECT EXISTS(SELECT * FROM table1 WHERE ...)

and per the documentation, you can SELECT anything.

Traditionally, an EXISTS subquery starts with SELECT *, but it could begin with SELECT 5 or SELECT column1 or anything at all. MySQL ignores the SELECT list in such a subquery, so it makes no difference.

VSCode cannot find module '@angular/core' or any other modules

for Visual Studio -->

    Seems like you don't have `node_modules` directory in your project folder.
     
    Execute this command where `package.json` file is located:
    
     npm install 

Using @property versus getters and setters

In Python you don't use getters or setters or properties just for the fun of it. You first just use attributes and then later, only if needed, eventually migrate to a property without having to change the code using your classes.

There is indeed a lot of code with extension .py that uses getters and setters and inheritance and pointless classes everywhere where e.g. a simple tuple would do, but it's code from people writing in C++ or Java using Python.

That's not Python code.

Changing capitalization of filenames in Git

To bulk git mv files to lowercase on macOS:

for f in *; do git mv "$f" "`echo $f | tr "[:upper:]" "[:lower:]"`"; done

It will lowercase all files in a folder.

Why do we not have a virtual constructor in C++?

Summary: the C++ Standard could specify a notation and behaviour for "virtual constructor"s that's reasonably intuitive and not too hard for compilers to support, but why make a Standard change for this specifically when the functionality can already be cleanly implemented using create() / clone() (see below)? It's not nearly as useful as many other language proposal in the pipeline.

Discussion

Let's postulate a "virtual constructor" mechanism:

Base* p = new Derived(...);
Base* p2 = new p->Base();  // possible syntax???

In the above, the first line constructs a Derived object, so *p's virtual dispatch table can reasonably supply a "virtual constructor" for use in the second line. (Dozens of answers on this page stating "the object doesn't yet exist so virtual construction is impossible" are unnecessarily myopically focused on the to-be-constructed object.)

The second line postulates the notation new p->Base() to request dynamic allocation and default construction of another Derived object.

Notes:

  • the compiler must orchestrate memory allocation before calling the constructor - constructors normally support automatic (informally "stack") allocation, static (for global/namespace scope and class-/function-static objects), and dynamic (informally "heap") when new is used

    • the size of object to be constructed by p->Base() can't generally be known at compile-time, so dynamic allocation is the only approach that makes sense

      • it is possible to allocate runtime-specified amounts of memory on the stack - e.g. GCC's variable-length array extension, alloca() - but leads to significant inefficiencies and complexities (e.g. here and here respectively)
  • for dynamic allocation it must return a pointer so memory can be deleted later.

  • the postulated notation explicitly lists new to emphasise dynamic allocation and the pointer result type.

The compiler would need to:

  • find out how much memory Derived needed, either by calling an implicit virtual sizeof function or having such information available via RTTI
  • call operator new(size_t) to allocate memory
  • invoke Derived() with placement new.

OR

  • create an extra vtable entry for a function that combines dynamic allocation and construction

So - it doesn't seem insurmountable to specify and implement virtual constructors, but the million-dollar question is: how would it be better than what's possible using existing C++ language features...? Personally, I see no benefit over the solution below.


`clone()` and `create()`

The C++ FAQ documents a "virtual constructor" idiom, containing virtual create() and clone() methods to default-construct or copy-construct a new dynamically-allocated object:

class Shape {
  public:
    virtual ~Shape() { } // A virtual destructor
    virtual void draw() = 0; // A pure virtual function
    virtual void move() = 0;
    // ...
    virtual Shape* clone() const = 0; // Uses the copy constructor
    virtual Shape* create() const = 0; // Uses the default constructor
};
class Circle : public Shape {
  public:
    Circle* clone() const; // Covariant Return Types; see below
    Circle* create() const; // Covariant Return Types; see below
    // ...
};
Circle* Circle::clone() const { return new Circle(*this); }
Circle* Circle::create() const { return new Circle(); }

It's also possible to change or overload create() to accept arguments, though to match the base class / interface's virtual function signature, arguments to overrides must exactly match one of the base class overloads. With these explicit user-provided facilities, it's easy to add logging, instrumentation, alter memory allocation etc..

Escape invalid XML characters in C#

As the way to remove invalid XML characters I suggest you to use XmlConvert.IsXmlChar method. It was added since .NET Framework 4 and is presented in Silverlight too. Here is the small sample:

void Main() {
    string content = "\v\f\0";
    Console.WriteLine(IsValidXmlString(content)); // False

    content = RemoveInvalidXmlChars(content);
    Console.WriteLine(IsValidXmlString(content)); // True
}

static string RemoveInvalidXmlChars(string text) {
    var validXmlChars = text.Where(ch => XmlConvert.IsXmlChar(ch)).ToArray();
    return new string(validXmlChars);
}

static bool IsValidXmlString(string text) {
    try {
        XmlConvert.VerifyXmlChars(text);
        return true;
    } catch {
        return false;
    }
}

And as the way to escape invalid XML characters I suggest you to use XmlConvert.EncodeName method. Here is the small sample:

void Main() {
    const string content = "\v\f\0";
    Console.WriteLine(IsValidXmlString(content)); // False

    string encoded = XmlConvert.EncodeName(content);
    Console.WriteLine(IsValidXmlString(encoded)); // True

    string decoded = XmlConvert.DecodeName(encoded);
    Console.WriteLine(content == decoded); // True
}

static bool IsValidXmlString(string text) {
    try {
        XmlConvert.VerifyXmlChars(text);
        return true;
    } catch {
        return false;
    }
}

Update: It should be mentioned that the encoding operation produces a string with a length which is greater or equal than a length of a source string. It might be important when you store a encoded string in a database in a string column with length limitation and validate source string length in your app to fit data column limitation.

GetElementByID - Multiple IDs

Dunno if something like this works in js, in PHP and Python which i use quite often it is possible. Maybe just use for loop like:

function doStuff(){
    for(i=1; i<=4; i++){
        var i = document.getElementById("myCiricle"+i);
    }
}

Get startup type of Windows service using PowerShell

It is possible with PowerShell 4.

Get-Service *spool* | select name,starttype | ft -AutoSize

screenshot

How to get multiple selected values of select box in php?

Change:

<select name="select2" ...

To:

<select name="select2[]" ...

What is the copy-and-swap idiom?

Assignment, at its heart, is two steps: tearing down the object's old state and building its new state as a copy of some other object's state.

Basically, that's what the destructor and the copy constructor do, so the first idea would be to delegate the work to them. However, since destruction mustn't fail, while construction might, we actually want to do it the other way around: first perform the constructive part and, if that succeeded, then do the destructive part. The copy-and-swap idiom is a way to do just that: It first calls a class' copy constructor to create a temporary object, then swaps its data with the temporary's, and then lets the temporary's destructor destroy the old state.
Since swap() is supposed to never fail, the only part which might fail is the copy-construction. That is performed first, and if it fails, nothing will be changed in the targeted object.

In its refined form, copy-and-swap is implemented by having the copy performed by initializing the (non-reference) parameter of the assignment operator:

T& operator=(T tmp)
{
    this->swap(tmp);
    return *this;
}

How do I get the color from a hexadecimal color code using .NET?

If you mean HashCode as in .GetHashCode(), I'm afraid you can't go back. Hash functions are not bi-directional, you can go 'forward' only, not back.

Follow Oded's suggestion if you need to get the color based on the hexadecimal value of the color.

C: printf a float value

You can do it like this:

printf("%.6f", myFloat);

6 represents the number of digits after the decimal separator.

How can I mock an ES6 module import using Jest?

The claims that you have to mock it at the top of your file are false.

Mock a named ES Import:

// import the named module
import { useWalkthroughAnimations } from '../hooks/useWalkthroughAnimations';

// mock the file and its named export
jest.mock('../hooks/useWalkthroughAnimations', () => ({
  useWalkthroughAnimations: jest.fn()
}));

// do whatever you need to do with your mocked function
useWalkthroughAnimations.mockReturnValue({ pageStyles, goToNextPage, page });

Difference between style = "position:absolute" and style = "position:relative"

Absolute positioning means that the element is taken completely out of the normal flow of the page layout. As far as the rest of the elements on the page are concerned, the absolutely positioned element simply doesn't exist. The element itself is then drawn separately, sort of "on top" of everything else, at the position you specify using the left, right, top and bottom attributes.

Using the position you specify with these attributes, the element is then placed at that position within its last ancestor element which has a position attribute of anything other than static (page elements default to static when no position attribute specified), or the document body (browser viewport) if no such ancestor exists.

For example, if I had this code:

<body>
  <div style="position:absolute; left: 20px; top: 20px;"></div>
</body>

...the <div> would be positioned 20px from the top of the browser viewport, and 20px from the left edge of same.

However, if I did something like this:

 <div id="outer" style="position:relative">
   <div id="inner" style="position:absolute; left: 20px; top: 20px;"></div>
 </div>

...then the inner div would be positioned 20px from the top of the outer div, and 20px from the left edge of same, because the outer div isn't positioned with position:static because we've explicitly set it to use position:relative.

Relative positioning, on the other hand, is just like stating no positioning at all, but the left, right, top and bottom attributes "nudge" the element out of their normal layout. The rest of the elements on the page still get laid out as if the element was in its normal spot though.

For example, if I had this code:

<span>Span1</span>
<span>Span2</span>
<span>Span3</span>

...then all three <span> elements would sit next to each other without overlapping.

If I set the second <span> to use relative positioning, like this:

<span>Span1</span>
<span style="position: relative; left: -5px;">Span2</span>
<span>Span3</span>

...then Span2 would overlap the right side of Span1 by 5px. Span1 and Span3 would sit in exactly the same place as they did in the first example, leaving a 5px gap between the right side of Span2 and the left side of Span3.

Hope that clarifies things a bit.

If statements for Checkboxes

In VB.Net

If Check1.checked and Not (Check2.checked) Then

ElseIf Check2.Checked and not Check1.Checked then

End If

@ViewChild in *ngIf

Working on Angular 8 No need to import ChangeDector

ngIf allows you not to load the element and avoid adding more stress to your application. Here's how I got it running without ChangeDetector

elem: ElementRef;

@ViewChild('elemOnHTML', {static: false}) set elemOnHTML(elemOnHTML: ElementRef) {
    if (!!elemOnHTML) {
      this.elem = elemOnHTML;
    }
}

Then when I change my ngIf value to be truthy I would use setTimeout like this for it to wait only for the next change cycle:

  this.showElem = true;
  console.log(this.elem); // undefined here
  setTimeout(() => {
    console.log(this.elem); // back here through ViewChild set
    this.elem.do();
  });

This also allowed me to avoid using any additional libraries or imports.

What is log4j's default log file dumping path

You have copy this sample code from Here,right?
now, as you can see there property file they have define, have you done same thing? if not then add below code in your project with property file for log4j

So the content of log4j.properties file would be as follows:

# Define the root logger with appender file
log = /usr/home/log4j
log4j.rootLogger = DEBUG, FILE

# Define the file appender
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=${log}/log.out

# Define the layout for file appender
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.conversionPattern=%m%n

make changes as per your requirement like log path

How to tell which disk Windows Used to Boot

You can use WMI to figure this out. The Win32_BootConfiguration class will tell you both the logical drive and the physical device from which Windows boots. Specifically, the Caption property will tell you which device you're booting from.

For example, in powershell, just type gwmi Win32_BootConfiguration to get your answer.

Page redirect with successful Ajax request

You can just redirect in your success handler, like this:

window.location.href = "thankyou.php";

Or since you're displaying results, wait a few seconds, for example this would wait 2 seconds:

setTimeout(function() {
  window.location.href = "thankyou.php";
}, 2000);

Failed to find Build Tools revision 23.0.1

Two solutions: You have to instal the required buildToolVersion or set it as described above.
Notice that if you are trying to set the buildToolsVersion "23.0.3" using Android Studio 3.0 or more it won't work until you remove all builversion you have keeping just one last version you use. I read this somewhere else and this works for me. Hope this helps.

Trying to SSH into an Amazon Ec2 instance - permission error

I know this is very late to the game ... but this always works for me:

step 1

ssh-add ~/.ssh/KEY_PAIR_NAME.pem

step 2, simply ssh in :)

ssh user_name@<instance public dns/ip>

e.g.

ssh [email protected]

hope this helps someone.

curl error 18 - transfer closed with outstanding read data remaining

I've solved this error by this way.

$ch = curl_init ();
curl_setopt ( $ch, CURLOPT_URL, 'http://www.someurl/' );
curl_setopt ( $ch, CURLOPT_TIMEOUT, 30);
ob_start();
$response = curl_exec ( $ch );
$data = ob_get_clean();
if(curl_getinfo($ch, CURLINFO_HTTP_CODE) == 200 ) success;

Error still occurs, but I can handle response data in variable.

How can I install an older version of a package via NuGet?

Now, it's very much simplified in Visual Studio 2015 and later. You can do downgrade / upgrade within the User interface itself, without executing commands in the Package Manager Console.

  1. Right click on your project and *go to Manage NuGet Packages.

  2. Look at the below image.

    • Select your Package and Choose the Version, which you wanted to install.

NuGet Package Manager window of Project

Very very simple, isn't it? :)

Abstract Class:-Real Time Example

The best example of an abstract class is GenericServlet. GenericServlet is the parent class of HttpServlet. It is an abstract class.

When inheriting 'GenericServlet' in a custom servlet class, the service() method must be overridden.

Updating the list view when the adapter data changes

substitute:

mMyListView.invalidate();

for:

((BaseAdapter) mMyListView.getAdapter()).notifyDataSetChanged(); 

If that doesnt work, refer to this thread: Android List view refresh

How to convert an Image to base64 string in java?

The problem is that you are returning the toString() of the call to Base64.encodeBase64(bytes) which returns a byte array. So what you get in the end is the default string representation of a byte array, which corresponds to the output you get.

Instead, you should do:

encodedfile = new String(Base64.encodeBase64(bytes), "UTF-8");

How can I insert data into a MySQL database?

#Server Connection to MySQL:

import MySQLdb
conn = MySQLdb.connect(host= "localhost",
                  user="root",
                  passwd="newpassword",
                  db="engy1")
x = conn.cursor()

try:
   x.execute("""INSERT INTO anooog1 VALUES (%s,%s)""",(188,90))
   conn.commit()
except:
   conn.rollback()

conn.close()

edit working for me:

>>> import MySQLdb
>>> #connect to db
... db = MySQLdb.connect("localhost","root","password","testdb" )
>>> 
>>> #setup cursor
... cursor = db.cursor()
>>> 
>>> #create anooog1 table
... cursor.execute("DROP TABLE IF EXISTS anooog1")
__main__:2: Warning: Unknown table 'anooog1'
0L
>>> 
>>> sql = """CREATE TABLE anooog1 (
...          COL1 INT,  
...          COL2 INT )"""
>>> cursor.execute(sql)
0L
>>> 
>>> #insert to table
... try:
...     cursor.execute("""INSERT INTO anooog1 VALUES (%s,%s)""",(188,90))
...     db.commit()
... except:     
...     db.rollback()
... 
1L
>>> #show table
... cursor.execute("""SELECT * FROM anooog1;""")
1L
>>> print cursor.fetchall()
((188L, 90L),)
>>> 
>>> db.close()

table in mysql;

mysql> use testdb;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> SELECT * FROM anooog1;
+------+------+
| COL1 | COL2 |
+------+------+
|  188 |   90 |
+------+------+
1 row in set (0.00 sec)

mysql> 

How to implement 2D vector array?

I'm not exactly sure what the problem is, as your example code has several errors and doesn't really make it clear what you're trying to do. But here's how you add to a specific row of a 2D vector:

// declare 2D vector
vector< vector<int> > myVector;
// make new row (arbitrary example)
vector<int> myRow(1,5);
myVector.push_back(myRow);
// add element to row
myVector[0].push_back(1);

Does this answer your question? If not, could you try to be more specific as to what you are having trouble with?

How do you use a variable in a regular expression?

You can always use indexOf repeatedly:

String.prototype.replaceAll = function(substring, replacement) {
    var result = '';
    var lastIndex = 0;

    while(true) {
        var index = this.indexOf(substring, lastIndex);
        if(index === -1) break;
        result += this.substring(lastIndex, index) + replacement;
        lastIndex = index + substring.length;
    }

    return result + this.substring(lastIndex);
};

This doesn’t go into an infinite loop when the replacement contains the match.

How to update (append to) an href in jquery?

var _href = $("a.directions-link").attr("href");
$("a.directions-link").attr("href", _href + '&saddr=50.1234567,-50.03452');

To loop with each()

$("a.directions-link").each(function() {
   var $this = $(this);       
   var _href = $this.attr("href"); 
   $this.attr("href", _href + '&saddr=50.1234567,-50.03452');
});

Check if a given key already exists in a dictionary and increment it

You are looking for collections.defaultdict (available for Python 2.5+). This

from collections import defaultdict

my_dict = defaultdict(int)
my_dict[key] += 1

will do what you want.

For regular Python dicts, if there is no value for a given key, you will not get None when accessing the dict -- a KeyError will be raised. So if you want to use a regular dict, instead of your code you would use

if key in my_dict:
    my_dict[key] += 1
else:
    my_dict[key] = 1

How to use onClick event on react Link component?

You should use this:

<Link to={this.props.myroute} onClick={hello}>Here</Link>

Or (if method hello lays at this class):

<Link to={this.props.myroute} onClick={this.hello}>Here</Link>

Update: For ES6 and latest if you want to bind some param with click method, you can use this:

    const someValue = 'some';  
....  
    <Link to={this.props.myroute} onClick={() => hello(someValue)}>Here</Link>

Convert canvas to PDF

You can achieve this by utilizing the jsPDF library and the toDataURL function.

I made a little demonstration:

_x000D_
_x000D_
var canvas = document.getElementById('myCanvas');_x000D_
var context = canvas.getContext('2d');_x000D_
_x000D_
// draw a blue cloud_x000D_
context.beginPath();_x000D_
context.moveTo(170, 80);_x000D_
context.bezierCurveTo(130, 100, 130, 150, 230, 150);_x000D_
context.bezierCurveTo(250, 180, 320, 180, 340, 150);_x000D_
context.bezierCurveTo(420, 150, 420, 120, 390, 100);_x000D_
context.bezierCurveTo(430, 40, 370, 30, 340, 50);_x000D_
context.bezierCurveTo(320, 5, 250, 20, 250, 50);_x000D_
context.bezierCurveTo(200, 5, 150, 20, 170, 80);_x000D_
context.closePath();_x000D_
context.lineWidth = 5;_x000D_
context.fillStyle = '#8ED6FF';_x000D_
context.fill();_x000D_
context.strokeStyle = '#0000ff';_x000D_
context.stroke();_x000D_
_x000D_
download.addEventListener("click", function() {_x000D_
  // only jpeg is supported by jsPDF_x000D_
  var imgData = canvas.toDataURL("image/jpeg", 1.0);_x000D_
  var pdf = new jsPDF();_x000D_
_x000D_
  pdf.addImage(imgData, 'JPEG', 0, 0);_x000D_
  pdf.save("download.pdf");_x000D_
}, false);
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jspdf/1.3.3/jspdf.min.js"></script>_x000D_
_x000D_
_x000D_
<canvas id="myCanvas" width="578" height="200"></canvas>_x000D_
<button id="download">download</button>
_x000D_
_x000D_
_x000D_

How to change a css class style through Javascript?

Since classList is supported in all major browsers and jQuery drops support for IE<9 (in 2.x branch as Stormblack points in the comment), considering this HTML

<div id="mydiv" class="oldclass">text</div>

you can comfortably use this syntax:

document.getElementById('mydiv').classList.add("newClass");

This will also result in:

<div id="mydiv" class="oldclass newclass">text</div>

plus you can also use remove, toggle, contains methods.

Upload DOC or PDF using PHP

Please add the correct mime-types to your code - at least these ones:

.jpeg -> image/jpeg
.gif  -> image/gif
.png  -> image/png

A list of mime-types can be found here.

Furthermore, simplify the code's logic and report an error number to help the first level support track down problems:

$allowedExts = array(
  "pdf", 
  "doc", 
  "docx"
); 

$allowedMimeTypes = array( 
  'application/msword',
  'text/pdf',
  'image/gif',
  'image/jpeg',
  'image/png'
);

$extension = end(explode(".", $_FILES["file"]["name"]));

if ( 20000 < $_FILES["file"]["size"]  ) {
  die( 'Please provide a smaller file [E/1].' );
}

if ( ! ( in_array($extension, $allowedExts ) ) ) {
  die('Please provide another file type [E/2].');
}

if ( in_array( $_FILES["file"]["type"], $allowedMimeTypes ) ) 
{      
 move_uploaded_file($_FILES["file"]["tmp_name"], "upload/" . $_FILES["file"]["name"]); 
}
else
{
die('Please provide another file type [E/3].');
}

How to print_r $_POST array?

The foreach loops work just fine, but you can also simply

print_r($_POST);

Or for pretty printing in a browser:

echo "<pre>";
print_r($_POST);
echo "</pre>";

How to make a great R reproducible example

Reproducible code is key to get help. However, there are many users that might be skeptical of pasting even a chunk of their data. For instance, they could be working with sensitive data or on an original data collected to use in a research paper. For any reason, I thought it would be nice to have a handy function for "deforming" my data before pasting it publicly. The anonymize function from the package SciencesPo is very silly, but for me it works nicely with dput function.

install.packages("SciencesPo")

dt <- data.frame(
    Z = sample(LETTERS,10),
    X = sample(1:10),
    Y = sample(c("yes", "no"), 10, replace = TRUE)
)

> dt
   Z  X   Y
1  D  8  no
2  T  1 yes
3  J  7  no
4  K  6  no
5  U  2  no
6  A 10 yes
7  Y  5  no
8  M  9 yes
9  X  4 yes
10 Z  3  no

Then I anonymize it:

> anonymize(dt)
     Z    X  Y
1   b2  2.5 c1
2   b6 -4.5 c2
3   b3  1.5 c1
4   b4  0.5 c1
5   b7 -3.5 c1
6   b1  4.5 c2
7   b9 -0.5 c1
8   b5  3.5 c2
9   b8 -1.5 c2
10 b10 -2.5 c1

One may also want to sample few variables instead of the whole data before apply anonymization and dput command.

    # sample two variables without replacement
> anonymize(sample.df(dt,5,vars=c("Y","X")))
   Y    X
1 a1 -0.4
2 a1  0.6
3 a2 -2.4
4 a1 -1.4
5 a2  3.6

ASP.Net MVC Redirect To A Different View

 if (true)
 {
   return View();
 }
 else
 {
   return View("another view name");
 }

Why does the arrow (->) operator in C exist?

I'll interpret your question as two questions: 1) why -> even exists, and 2) why . does not automatically dereference the pointer. Answers to both questions have historical roots.

Why does -> even exist?

In one of the very first versions of C language (which I will refer as CRM for "C Reference Manual", which came with 6th Edition Unix in May 1975), operator -> had very exclusive meaning, not synonymous with * and . combination

The C language described by CRM was very different from the modern C in many respects. In CRM struct members implemented the global concept of byte offset, which could be added to any address value with no type restrictions. I.e. all names of all struct members had independent global meaning (and, therefore, had to be unique). For example you could declare

struct S {
  int a;
  int b;
};

and name a would stand for offset 0, while name b would stand for offset 2 (assuming int type of size 2 and no padding). The language required all members of all structs in the translation unit either have unique names or stand for the same offset value. E.g. in the same translation unit you could additionally declare

struct X {
  int a;
  int x;
};

and that would be OK, since the name a would consistently stand for offset 0. But this additional declaration

struct Y {
  int b;
  int a;
};

would be formally invalid, since it attempted to "redefine" a as offset 2 and b as offset 0.

And this is where the -> operator comes in. Since every struct member name had its own self-sufficient global meaning, the language supported expressions like these

int i = 5;
i->b = 42;  /* Write 42 into `int` at address 7 */
100->a = 0; /* Write 0 into `int` at address 100 */

The first assignment was interpreted by the compiler as "take address 5, add offset 2 to it and assign 42 to the int value at the resultant address". I.e. the above would assign 42 to int value at address 7. Note that this use of -> did not care about the type of the expression on the left-hand side. The left hand side was interpreted as an rvalue numerical address (be it a pointer or an integer).

This sort of trickery was not possible with * and . combination. You could not do

(*i).b = 42;

since *i is already an invalid expression. The * operator, since it is separate from ., imposes more strict type requirements on its operand. To provide a capability to work around this limitation CRM introduced the -> operator, which is independent from the type of the left-hand operand.

As Keith noted in the comments, this difference between -> and *+. combination is what CRM is referring to as "relaxation of the requirement" in 7.1.8: Except for the relaxation of the requirement that E1 be of pointer type, the expression E1->MOS is exactly equivalent to (*E1).MOS

Later, in K&R C many features originally described in CRM were significantly reworked. The idea of "struct member as global offset identifier" was completely removed. And the functionality of -> operator became fully identical to the functionality of * and . combination.

Why can't . dereference the pointer automatically?

Again, in CRM version of the language the left operand of the . operator was required to be an lvalue. That was the only requirement imposed on that operand (and that's what made it different from ->, as explained above). Note that CRM did not require the left operand of . to have a struct type. It just required it to be an lvalue, any lvalue. This means that in CRM version of C you could write code like this

struct S { int a, b; };
struct T { float x, y, z; };

struct T c;
c.b = 55;

In this case the compiler would write 55 into an int value positioned at byte-offset 2 in the continuous memory block known as c, even though type struct T had no field named b. The compiler would not care about the actual type of c at all. All it cared about is that c was an lvalue: some sort of writable memory block.

Now note that if you did this

S *s;
...
s.b = 42;

the code would be considered valid (since s is also an lvalue) and the compiler would simply attempt to write data into the pointer s itself, at byte-offset 2. Needless to say, things like this could easily result in memory overrun, but the language did not concern itself with such matters.

I.e. in that version of the language your proposed idea about overloading operator . for pointer types would not work: operator . already had very specific meaning when used with pointers (with lvalue pointers or with any lvalues at all). It was very weird functionality, no doubt. But it was there at the time.

Of course, this weird functionality is not a very strong reason against introducing overloaded . operator for pointers (as you suggested) in the reworked version of C - K&R C. But it hasn't been done. Maybe at that time there was some legacy code written in CRM version of C that had to be supported.

(The URL for the 1975 C Reference Manual may not be stable. Another copy, possibly with some subtle differences, is here.)

How to create a trie in Python

from collections import defaultdict

Define Trie:

_trie = lambda: defaultdict(_trie)

Create Trie:

trie = _trie()
for s in ["cat", "bat", "rat", "cam"]:
    curr = trie
    for c in s:
        curr = curr[c]
    curr.setdefault("_end")

Lookup:

def word_exist(trie, word):
    curr = trie
    for w in word:
        if w not in curr:
            return False
        curr = curr[w]
    return '_end' in curr

Test:

print(word_exist(trie, 'cam'))

Send Mail to multiple Recipients in java

So ... it took many months, but still ... You can send email to multiple recipients by using the ',' as separator and

message.setRecipients(Message.RecipientType.CC, "[email protected],[email protected],[email protected]");

is ok. At least in JavaMail 1.4.5

TypeError: Image data can not convert to float

As for cv2 is concerned.

  1. You might not have provided the right file type while cv2.imread(). eg jpg instead of png.
  2. Or you are providing image path instead of image's array. eg plt.imshow(img_path),

try cv2.imread(img_path) first then plt.imshow(img) or cv2.imshow(img).

What is the difference between 127.0.0.1 and localhost

Well, the most likely difference is that you still have to do an actual lookup of localhost somewhere.

If you use 127.0.0.1, then (intelligent) software will just turn that directly into an IP address and use it. Some implementations of gethostbyname will detect the dotted format (and presumably the equivalent IPv6 format) and not do a lookup at all.

Otherwise, the name has to be resolved. And there's no guarantee that your hosts file will actually be used for that resolution (first, or at all) so localhost may become a totally different IP address.

By that I mean that, on some systems, a local hosts file can be bypassed. The host.conf file controls this on Linux (and many other Unices).

Split varchar into separate columns in Oracle

Simple way is to convert into column

SELECT COLUMN_VALUE FROM TABLE (SPLIT ('19869,19572,19223,18898,10155,'))

CREATE TYPE split_tbl as TABLE OF VARCHAR2(32767);

CREATE OR REPLACE FUNCTION split (p_list VARCHAR2, p_del VARCHAR2 := ',')
   RETURN split_tbl
   PIPELINED IS
   l_idx PLS_INTEGER;
   l_list VARCHAR2 (32767) := p_list;
   l_value VARCHAR2 (32767);
BEGIN
   LOOP
      l_idx := INSTR (l_list, p_del);

      IF l_idx > 0 THEN
         PIPE ROW (SUBSTR (l_list, 1, l_idx - 1));
         l_list := SUBSTR (l_list, l_idx + LENGTH (p_del));
      ELSE
         PIPE ROW (l_list);
         EXIT;
      END IF;
   END LOOP;

   RETURN;
END split;

In an array of objects, fastest way to find the index of an object whose attributes match a search

A new way using ES6

let picked_element = array.filter(element => element.id === 0);

Split a string by a delimiter in python

When you have two or more (in the example below there're three) elements in the string, then you can use comma to separate these items:

date, time, event_name = ev.get_text(separator='@').split("@")

After this line of code, the three variables will have values from three parts of the variable ev

So, if the variable ev contains this string and we apply separator '@':

Sa., 23. März@19:00@Klavier + Orchester: SPEZIAL

Then, after split operation the variable

  • date will have value "Sa., 23. März"
  • time will have value "19:00"
  • event_name will have value "Klavier + Orchester: SPEZIAL"

Is it possible to run one logrotate check manually?

The way to run all of logrotate is:

logrotate -f /etc/logrotate.conf

that will run the primary logrotate file, which includes the other logrotate configurations as well

Insert data into hive table

You can insert new data into table by two ways.

  1. Load the data of a file into table using load command.

    LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename.
    
  2. You can insert new data into table by using select query.

    INSERT INTO table tablename1 select columnlist FROM secondtable;
    

TypeError: Invalid dimensions for image data when plotting array with imshow()

There is a (somewhat) related question on StackOverflow:

Here the problem was that an array of shape (nx,ny,1) is still considered a 3D array, and must be squeezed or sliced into a 2D array.

More generally, the reason for the Exception

TypeError: Invalid dimensions for image data

is shown here: matplotlib.pyplot.imshow() needs a 2D array, or a 3D array with the third dimension being of shape 3 or 4!

You can easily check this with (these checks are done by imshow, this function is only meant to give a more specific message in case it's not a valid input):

from __future__ import print_function
import numpy as np

def valid_imshow_data(data):
    data = np.asarray(data)
    if data.ndim == 2:
        return True
    elif data.ndim == 3:
        if 3 <= data.shape[2] <= 4:
            return True
        else:
            print('The "data" has 3 dimensions but the last dimension '
                  'must have a length of 3 (RGB) or 4 (RGBA), not "{}".'
                  ''.format(data.shape[2]))
            return False
    else:
        print('To visualize an image the data must be 2 dimensional or '
              '3 dimensional, not "{}".'
              ''.format(data.ndim))
        return False

In your case:

>>> new_SN_map = np.array([1,2,3])
>>> valid_imshow_data(new_SN_map)
To visualize an image the data must be 2 dimensional or 3 dimensional, not "1".
False

The np.asarray is what is done internally by matplotlib.pyplot.imshow so it's generally best you do it too. If you have a numpy array it's obsolete but if not (for example a list) it's necessary.


In your specific case you got a 1D array, so you need to add a dimension with np.expand_dims()

import matplotlib.pyplot as plt
a = np.array([1,2,3,4,5])
a = np.expand_dims(a, axis=0)  # or axis=1
plt.imshow(a)
plt.show()

enter image description here

or just use something that accepts 1D arrays like plot:

a = np.array([1,2,3,4,5])
plt.plot(a)
plt.show()

enter image description here

How to: Install Plugin in Android Studio

  1. Launch Android Studio application
  2. Choose Project Settings
  3. Choose Plugin from disk, if on disk then choose that location of *.jar, in my case is GenyMotion jar
  4. Click on Apply and OK.
  5. Then Android studio will ask for Restart.

That's all Folks! enter image description here

Getting selected value of a combobox

Try this:

int selectedIndex = comboBox1.SelectedIndex;
comboBox1.SelectedItem.ToString();
int selectedValue = (int)comboBox1.Items[selectedIndex];

Monitor network activity in Android Phones

You would need to root the phone and cross compile tcpdump or use someone else's already compiled version.

You might find it easier to do these experiments with the emulator, in which case you could do the monitoring from the hosting pc. If you must use a real device, another option would be to put it on a wifi network hanging off of a secondary interface on a linux box running tcpdump.

I don't know off the top of my head how you would go about filtering by a specific process. One suggestion I found in some quick googling is to use strace on the subject process instead of tcpdump on the system.

convert a char* to std::string

If you already know size of the char*, use this instead

char* data = ...;
int size = ...;
std::string myString(data, size);

This doesn't use strlen.

EDIT: If string variable already exists, use assign():

std::string myString;
char* data = ...;
int size = ...;
myString.assign(data, size);

Jenkins Pipeline Wipe Out Workspace

Cleaning up : Since the post section of a Pipeline is guaranteed to run at the end of a Pipeline’s execution, we can add some notification or other steps to perform finalization, notification, or other end-of-Pipeline tasks.

pipeline {
    agent any
    stages {
        stage('No-op') {
            steps {
                sh 'ls'
            }
        }
    }
    post {
        cleanup {
            echo 'One way or another, I have finished'
            deleteDir() /* clean up our workspace */
        }
    }
}

How to select element using XPATH syntax on Selenium for Python?

HTML

<div id='a'>
  <div>
    <a class='click'>abc</a>
  </div>
</div>

You could use the XPATH as :

//div[@id='a']//a[@class='click']

output

<a class="click">abc</a>

That said your Python code should be as :

driver.find_element_by_xpath("//div[@id='a']//a[@class='click']")

Removing character in list of strings

Beside using loop and for comprehension, you could also use map

lst = [("aaaa8"),("bb8"),("ccc8"),("dddddd8")]
mylst = map(lambda each:each.strip("8"), lst)
print mylst

How to set default text for a Tkinter Entry widget

Use Entry.insert. For example:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
e = Entry(root)
e.insert(END, 'default text')
e.pack()
root.mainloop()

Or use textvariable option:

try:
    from tkinter import *  # Python 3.x
except Import Error:
    from Tkinter import *  # Python 2.x

root = Tk()
v = StringVar(root, value='default text')
e = Entry(root, textvariable=v)
e.pack()
root.mainloop()

How can I get a process handle by its name in C++?

OpenProcess Function

From MSDN:

To open a handle to another local process and obtain full access rights, you must enable the SeDebugPrivilege privilege.

How to make a input field readonly with JavaScript?

Try This :

document.getElementById(<element_ID>).readOnly=true;

Download multiple files as a zip-file using php

You can use the ZipArchive class to create a ZIP file and stream it to the client. Something like:

$files = array('readme.txt', 'test.html', 'image.gif');
$zipname = 'file.zip';
$zip = new ZipArchive;
$zip->open($zipname, ZipArchive::CREATE);
foreach ($files as $file) {
  $zip->addFile($file);
}
$zip->close();

and to stream it:

header('Content-Type: application/zip');
header('Content-disposition: attachment; filename='.$zipname);
header('Content-Length: ' . filesize($zipname));
readfile($zipname);

The second line forces the browser to present a download box to the user and prompts the name filename.zip. The third line is optional but certain (mainly older) browsers have issues in certain cases without the content size being specified.

How do I create a new column from the output of pandas groupby().sum()?

How do I create a new column with Groupby().Sum()?

There are two ways - one straightforward and the other slightly more interesting.


Everybody's Favorite: GroupBy.transform() with 'sum'

@Ed Chum's answer can be simplified, a bit. Call DataFrame.groupby rather than Series.groupby. This results in simpler syntax.

# The setup.
df[['Date', 'Data3']]

         Date  Data3
0  2015-05-08      5
1  2015-05-07      8
2  2015-05-06      6
3  2015-05-05      1
4  2015-05-08     50
5  2015-05-07    100
6  2015-05-06     60
7  2015-05-05    120

df.groupby('Date')['Data3'].transform('sum')

0     55
1    108
2     66
3    121
4     55
5    108
6     66
7    121
Name: Data3, dtype: int64 

It's a tad faster,

df2 = pd.concat([df] * 12345)

%timeit df2['Data3'].groupby(df['Date']).transform('sum')
%timeit df2.groupby('Date')['Data3'].transform('sum')

10.4 ms ± 367 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
8.58 ms ± 559 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

Unconventional, but Worth your Consideration: GroupBy.sum() + Series.map()

I stumbled upon an interesting idiosyncrasy in the API. From what I tell, you can reproduce this on any major version over 0.20 (I tested this on 0.23 and 0.24). It seems like you consistently can shave off a few milliseconds of the time taken by transform if you instead use a direct function of GroupBy and broadcast it using map:

df.Date.map(df.groupby('Date')['Data3'].sum())

0     55
1    108
2     66
3    121
4     55
5    108
6     66
7    121
Name: Date, dtype: int64

Compare with

df.groupby('Date')['Data3'].transform('sum')

0     55
1    108
2     66
3    121
4     55
5    108
6     66
7    121
Name: Data3, dtype: int64

My tests show that map is a bit faster if you can afford to use the direct GroupBy function (such as mean, min, max, first, etc). It is more or less faster for most general situations upto around ~200 thousand records. After that, the performance really depends on the data.

(Left: v0.23, Right: v0.24)

Nice alternative to know, and better if you have smaller frames with smaller numbers of groups. . . but I would recommend transform as a first choice. Thought this was worth sharing anyway.

Benchmarking code, for reference:

import perfplot

perfplot.show(
    setup=lambda n: pd.DataFrame({'A': np.random.choice(n//10, n), 'B': np.ones(n)}),
    kernels=[
        lambda df: df.groupby('A')['B'].transform('sum'),
        lambda df:  df.A.map(df.groupby('A')['B'].sum()),
    ],
    labels=['GroupBy.transform', 'GroupBy.sum + map'],
    n_range=[2**k for k in range(5, 20)],
    xlabel='N',
    logy=True,
    logx=True
)

Passing 'this' to an onclick event

You can always call funciton differently: foo.call(this); in this way you will be able to use this context inside the function.

Example:

<button onclick="foo.call(this)" id="bar">Button</button>?

var foo = function()
{
    this.innerHTML = "Not a button";
};

PHP Session Destroy on Log Out Button

First give the link of logout.php page in that logout button.In that page make the code which is given below:

Here is the code:

<?php
 session_start();
 session_destroy();
?>

When the session has started, the session for the last/current user has been started, so don't need to declare the username. It will be deleted automatically by the session_destroy method.

What characters can be used for up/down triangle (arrow without stem) for display in HTML?

Since you're using these arrows for a toggle switch you may want to consider creating these arrows with an html element using the following styles instead of unicode characters.

.upparrow {
   height: 0;
   width: 0;
   border: 4px solid transparent;
   border-bottom-color: #000;
}

.downarrow {
   height: 0;
   width: 0;
   border: 4px solid transparent;
   border-top-color: #000;
}

http://jsfiddle.net/FrsGR/

What is the difference between match_parent and fill_parent?

1. match_parent

When you set layout width and height as match_parent, it will occupy the complete area that the parent view has, i.e. it will be as big as the parent.

Note : If parent is applied a padding then that space would not be included.

When we create a layout.xml by default we have RelativeLayout as default parent View with android:layout_width="match_parent" and android:layout_height="match_parent" i.e it occupies the complete width and height of the mobile screen.

Also note that padding is applied to all sides,

android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"

Now lets add a sub-view LinearLayout and sets its layout_width="match_parent" and layout_height="match_parent", the graphical view would display something like this,

match_parent_example

Code

xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.code2care.android.togglebuttonexample.MainActivity" >

android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="11dp"
android:background="#FFFFEE"
android:orientation="vertical" >

2. fill_parent :

This is same as match_parent, fill_parent was depreciated in API level 8. So if you are using API level 8 or above you must avoid using fill_parent

Lets follow the same steps as we did for match_parent, just instead use fill_parent everywhere.

You would see that there is no difference in behaviour in both fill_parent and match parent.

Prevent textbox autofill with previously entered values

By making AutoCompleteType="Disabled",

    <asp:TextBox runat="server" ID="txt_userid" AutoCompleteType="Disabled"></asp:TextBox>  

By setting autocomplete="off",

    <asp:TextBox runat="server" ID="txt_userid" autocomplete="off"></asp:TextBox>  

By Setting Form autocomplete="off",

    <form id="form1" runat="server" autocomplete="off">  
    //your content  
    </form>  

By using code in .cs page,

    protected void Page_Load(object sender, EventArgs e)   
    {  
        if (!Page.IsPostBack)  
        {  
            txt_userid.Attributes.Add("autocomplete", "off");  
        }  
    }  

By Using Jquery

    <head runat = "server" >  
        < title > < /title> < script src = "Scripts/jquery-1.6.4.min.js" > < /script> < script type = "text/javascript" >  
        $(document).ready(function()  
        {  
            $('#txt_userid').attr('autocomplete', 'off');  
        });  
    //document.getElementById("txt_userid").autocomplete = "off"  
    < /script>  

and here is my textbox in ,

    <asp:TextBox runat="server" ID="txt_userid" ></asp:TextBox>  

By Setting textbox attribute in code,

    protected void Page_Load(object sender, EventArgs e)   
    {  
        if (!Page.IsPostBack)  
        {  
            txt_userid.Attributes.Add("autocomplete", "off");  
        }  
    } 

Bootstrap 3 - disable navbar collapse

Here's an approach that leaves the default collapse behavior unchanged while allowing a new section of navigation to always remain visible. Its an augmentation of navbar; navbar-header-menu is a CSS class I have created and is not part of Bootstrap proper.

Place this in the navbar-header element after navbar-brand:

<div class="navbar-header-menu">
    <ul class="nav navbar-nav">
        <li class="active"><a href="#">I'm always visible</a></li>
    </ul>
    <form class="navbar-form" role="search">
        <div class="form-group">
            <input type="text" class="form-control" placeholder="Search">
        </div>
        <button type="submit" class="btn btn-default">Submit</button>
    </form>
</div>

Add this CSS:

.navbar-header-menu {
    float: left;
}

    .navbar-header-menu > .navbar-nav {
        float: left;
        margin: 0;
    }

        .navbar-header-menu > .navbar-nav > li {
            float: left;
        }

            .navbar-header-menu > .navbar-nav > li > a {
                padding-top: 15px;
                padding-bottom: 15px;
            }

        .navbar-header-menu > .navbar-nav .open .dropdown-menu {
            position: absolute;
            float: left;
            width: auto;
            margin-top: 0;
            background-color: #fff;
            border: 1px solid #ccc;
            border: 1px solid rgba(0,0,0,.15);
            -webkit-box-shadow: 0 6px 12px rgba(0,0,0,.175);
            box-shadow: 0 6px 12px rgba(0,0,0,.175);
        }

    .navbar-header-menu > .navbar-form {
        float: left;
        width: auto;
        padding-top: 0;
        padding-bottom: 0;
        margin-right: 0;
        margin-left: 0;
        border: 0;
        -webkit-box-shadow: none;
        box-shadow: none;
    }

        .navbar-header-menu > .navbar-form > .form-group {
            display: inline-block;
            margin-bottom: 0;
            vertical-align: middle;
        }

    .navbar-header-menu > .navbar-left {
        float: left;
    }

    .navbar-header-menu > .navbar-right {
        float: right !important;
    }

    .navbar-header-menu > *.navbar-right:last-child {
        margin-right: -15px !important;
    }

Check the fiddle: http://jsfiddle.net/L2txunqo/

Caveat: navbar-right can be used to sort elements visually but is not guaranteed to pull the element to the furthest right portion of the screen. The fiddle demonstrates that behavior with the navbar-form.

Adding files to a GitHub repository

Open github app. Then, add the Folder of files into the github repo file onto your computer (You WILL need to copy the repo onto your computer. Most repo files are located in the following directory: C:\Users\USERNAME\Documents\GitHub\REPONAME) Then, in the github app, check our your repo. You can easily commit from there.

JavaScript Array to Set

Just pass the array to the Set constructor. The Set constructor accepts an iterable parameter. The Array object implements the iterable protocol, so its a valid parameter.

_x000D_
_x000D_
var arr = [55, 44, 65];_x000D_
var set = new Set(arr);_x000D_
console.log(set.size === arr.length);_x000D_
console.log(set.has(65));
_x000D_
_x000D_
_x000D_

See here

Log all queries in mysql

OS / mysql version:

$ uname -a
Darwin Raphaels-MacBook-Pro.local 15.6.0 Darwin Kernel Version 15.6.0: Thu Jun 21 20:07:40 PDT 2018; root:xnu-3248.73.11~1/RELEASE_X86_64 x86_64

$ mysql --version
/usr/local/mysql/bin/mysql  Ver 14.14 Distrib 5.6.23, for osx10.8 (x86_64) using  EditLine wrapper

Adding logging (example, I don't think /var/log/... is the best path on Mac OS but that worked:

sudo vi ./usr/local/mysql-5.6.23-osx10.8-x86_64/my.cnf

[mysqld]
general_log = on
general_log_file=/var/log/mysql/mysqld_general.log

Restarted Mysql

Result:

$ sudo tail -f /var/log/mysql/mysqld_general.log
181210  9:41:04    21 Connect   root@localhost on employees
           21 Query /* mysql-connector-java-5.1.47 ( Revision: fe1903b1ecb4a96a917f7ed3190d80c049b1de29 ) */SELECT  @@session.auto_increment_increment AS auto_increment_increment, @@character_set_client AS character_set_client, @@character_set_connection AS character_set_connection, @@character_set_results AS character_set_results, @@character_set_server AS character_set_server, @@collation_server AS collation_server, @@collation_connection AS collation_connection, @@init_connect AS init_connect, @@interactive_timeout AS interactive_timeout, @@license AS license, @@lower_case_table_names AS lower_case_table_names, @@max_allowed_packet AS max_allowed_packet, @@net_buffer_length AS net_buffer_length, @@net_write_timeout AS net_write_timeout, @@query_cache_size AS query_cache_size, @@query_cache_type AS query_cache_type, @@sql_mode AS sql_mode, @@system_time_zone AS system_time_zone, @@time_zone AS time_zone, @@tx_isolation AS transaction_isolation, @@wait_timeout AS wait_timeout
           21 Query SET NAMES latin1
           21 Query SET character_set_results = NULL
           21 Query SET autocommit=1
           21 Query SELECT USER()
           21 Query SELECT USER()
181210  9:41:10    21 Query show tables
181210  9:41:25    21 Query select count(*) from current_dept_emp

HMAC-SHA256 Algorithm for signature calculation

The answer that you got there is correct. One minor thing in the code above, you need to init(key) before you can call doFinal()

    final Charset charSet = Charset.forName("US-ASCII");
    final Mac sha256_HMAC = Mac.getInstance("HmacSHA256");

    final SecretKeySpec secret_key = new javax.crypto.spec.SecretKeySpec(charSet.encode("key").array(), "HmacSHA256");
    try {
        sha256_HMAC.init(secret_key);
    } catch (InvalidKeyException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    ...

Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set()

If you are running your application just on localhost and it is not yet live, I believe it is very difficult to send mail using this.

Once you put your application online, I believe that this problem should be automatically solved. By the way,ini_set() helps you to change the values in php.ini during run time.

This is the same question as Failed to connect to mailserver at "localhost" port 25

also check this php mail function not working

How do you express binary literals in Python?

>>> print int('01010101111',2)
687
>>> print int('11111111',2)
255

Another way.

Way to go from recursion to iteration

Just killing time... A recursive function

void foo(Node* node)
{
    if(node == NULL)
       return;
    // Do something with node...
    foo(node->left);
    foo(node->right);
}

can be converted to

void foo(Node* node)
{
    if(node == NULL)
       return;

    // Do something with node...

    stack.push(node->right);
    stack.push(node->left);

    while(!stack.empty()) {
         node1 = stack.pop();
         if(node1 == NULL)
            continue;
         // Do something with node1...
         stack.push(node1->right);             
         stack.push(node1->left);
    }

}

JavaScript sleep/wait before continuing

JS does not have a sleep function, it has setTimeout() or setInterval() functions.

If you can move the code that you need to run after the pause into the setTimeout() callback, you can do something like this:

//code before the pause
setTimeout(function(){
    //do what you need here
}, 2000);

see example here : http://jsfiddle.net/9LZQp/

This won't halt the execution of your script, but due to the fact that setTimeout() is an asynchronous function, this code

console.log("HELLO");
setTimeout(function(){
    console.log("THIS IS");
}, 2000);
console.log("DOG");

will print this in the console:

HELLO
DOG
THIS IS

(note that DOG is printed before THIS IS)


You can use the following code to simulate a sleep for short periods of time:

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

now, if you want to sleep for 1 second, just use:

sleep(1000);

example: http://jsfiddle.net/HrJku/1/

please note that this code will keep your script busy for n milliseconds. This will not only stop execution of Javascript on your page, but depending on the browser implementation, may possibly make the page completely unresponsive, and possibly make the entire browser unresponsive. In other words this is almost always the wrong thing to do.

Does WhatsApp offer an open API?

  1. is the correct answer. WhatsApp is intentionally a closed system without an API for external access.

There were several projects available that reverse engineered the WhatsApp webservice interfaces. However, to my knowledge all of them are now discontinued/defunct due to legal action against them from WhatsApp.

For mobile phone applications there is a limited URL-Scheme-API available on IPhone and Android (Android-intent possible as well).

Face recognition Library

I would think Eigenface, which you are doing already, is the way to go if you want to calculate the distance between faces. You could try out different approaches like Support Vector Machine or Hidden Markov Model. I found a page that lists major algorithms that could be used for facial recognition: Face Recognition Homepage.

Also, when you say "better performance," do you mean speed or accuracy? What kind of problem are you having? How varying are the data? Are they mostly frontal face or do they include profiles?

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

This works for me:

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

Inserting HTML elements with JavaScript

In old school JavaScript, you could do this:

document.body.innerHTML = '<p id="foo">Some HTML</p>' + document.body.innerHTML;

In response to your comment:

[...] I was interested in declaring the source of a new element's attributes and events, not the innerHTML of an element.

You need to inject the new HTML into the DOM, though; that's why innerHTML is used in the old school JavaScript example. The innerHTML of the BODY element is prepended with the new HTML. We're not really touching the existing HTML inside the BODY.

I'll rewrite the abovementioned example to clarify this:

var newElement = '<p id="foo">This is some dynamically added HTML. Yay!</p>';
var bodyElement = document.body;
bodyElement.innerHTML = newElement + bodyElement.innerHTML;
// note that += cannot be used here; this would result in 'NaN'

Using a JavaScript framework would make this code much less verbose and improve readability. For example, jQuery allows you to do the following:

$('body').prepend('<p id="foo">Some HTML</p>');

Storing database records into array

$mysearch="Your Search Name";
$query = mysql_query("SELECT * FROM table");
$c=0;
// set array
$array = array();

// look through query
while($row = mysql_fetch_assoc($query)){

  // add each row returned into an array
  $array[] = $row;
  $c++;
}

for($i=0;$i=$c;$i++)
{
if($array[i]['username']==$mysearch)
{
// name found
}
}

Disable button in jQuery

For Jquery UI buttons this works :

$("#buttonId").button( "option", "disabled", true | false );

How to call a C# function from JavaScript?

You can use a Web Method and Ajax:

<script type="text/javascript">             //Default.aspx
   function DeleteKartItems() {     
         $.ajax({
         type: "POST",
         url: 'Default.aspx/DeleteItem',
         data: "",
         contentType: "application/json; charset=utf-8",
         dataType: "json",
         success: function (msg) {
             $("#divResult").html("success");
         },
         error: function (e) {
             $("#divResult").html("Something Wrong.");
         }
     });
   }
</script>

[WebMethod]                                 //Default.aspx.cs
public static void DeleteItem()
{
    //Your Logic
}

Default visibility for C# classes and members (fields, methods, etc.)?

By default, the access modifier for a class is internal. That means to say, a class is accessible within the same assembly. But if we want the class to be accessed from other assemblies then it has to be made public.

import module from string variable

importlib.import_module is what you are looking for. It returns the imported module. (Only available for Python >= 2.7 or 3.x):

import importlib

mymodule = importlib.import_module('matplotlib.text')

You can thereafter access anything in the module as mymodule.myclass, etc.

Invoking a PHP script from a MySQL trigger

If you have transaction logs in you MySQL, you can create a trigger for purpose of a log instance creation. A cronjob could monitor this log and based on events created by your trigger it could invoke a php script. That is if you absolutely have no control over you insertion.

Is there an easy way to convert Android Application to IPad, IPhone

I'm not sure how helpful this answer is for your current application, but it may prove helpful for the next applications that you will be developing.

As iOS does not use Java like Android, your options are quite limited:

1) if your application is written mostly in C/C++ using JNI, you can write a wrapper and interface it with the iOS (i.e. provide callbacks from iOS to your JNI written function). There may be frameworks out there that help you do this easier, but there's still the problem of integrating the application and adapting it to the framework (and of course the fact that the application has to be written in C/C++).

2) rewrite it for iOS. I don't know whether there are any good companies that do this for you. Also, due to the variety of applications that can be written which can use different services and API, there may not be any software that can port it for you (I guess this kind of software is like a gold mine heh) or do a very good job at that.

3) I think that there are Java->C/C++ converters, but there won't help you at all when it comes to API differences. Also, you may find yourself struggling more to get the converted code working on any of the platforms rather than rewriting your application from scratch for iOS.

The problem depends quite a bit on the services and APIs your application is using. I haven't really look this up, but there may be some APIs that provide certain functionality in Android that iOS doesn't provide.

Using C/C++ and natively compiling it for the desired platform looks like the way to go for Android-iOS-Win7Mobile cross-platform development. This gets you somewhat of an application core/kernel which you can use to do the actual application logic.

As for the OS specific parts (APIs) that your application is using, you'll have to set up communication interfaces between them and your application's core.

Select Last Row in the Table

You can use the latest scope provided by Laravel with the field you would like to filter, let's say it'll be ordered by ID, then:

Model::latest('id')->first();

So in this way, you can avoid ordering by created_at field by default at Laravel.

how to loop through rows columns in excel VBA Macro

I'd recommend the Range object's AutoFill method for this:

rngSource.AutoFill Destination:=rngDest

Specify the Source range that contains the values or formulas you want to fill down, and the Destination range as the whole range that you want the cells filled to. The Destination range must include the Source range. You can fill across as well as down.

It works exactly the same way as it would if you manually "dragged" the cells at the corner with the mouse; absolute and relative formulas work as expected.

Here's an example:

'Set some example values'
Range("A1").Value = "1"
Range("B1").Formula = "=NOW()"
Range("C1").Formula = "=B1+A1"

'AutoFill the values / formulas to row 20'
Range("A1:C1").AutoFill Destination:=Range("A1:C20")

Hope this helps.

rsync - mkstemp failed: Permission denied (13)

Make sure the user you're rsync'd into on the remote machine has write access to the contents of the folder AND the folder itself, as rsync tried to update the modification time on the folder itself.

JavaScript variable assignments from tuples

You can do something similar:

var tuple = Object.freeze({ name:'Bob', age:14 })

and then refer to name and age as attributes

tuple.name 
tuple.age 

What is the difference between bottom-up and top-down?

Simply saying top down approach uses recursion for calling Sub problems again and again
where as bottom up approach use the single without calling any one and hence it is more efficient.

SqlBulkCopy - The given value of type String from the data source cannot be converted to type money of the specified target column

@Corey - It just simply strips out all invalid characters. However, your comment made me think of the answer.

The problem was that many of the fields in my database are nullable. When using SqlBulkCopy, an empty string is not inserted as a null value. So in the case of my fields that are not varchar (bit, int, decimal, datetime, etc) it was trying to insert an empty string, which obviously is not valid for that data type.

The solution was to modify my loop where I validate the values to this (repeated for each datatype that is not string)

//--- convert decimal values
foreach (DataColumn DecCol in DecimalColumns)
{
     if(string.IsNullOrEmpty(dr[DecCol].ToString()))
          dr[DecCol] = null; //--- this had to be set to null, not empty
     else
          dr[DecCol] = Helpers.CleanDecimal(dr[DecCol].ToString());
}

After making the adjustments above, everything inserts without issues.

How to see my Eclipse version?

Same issue i was getting , but When we open our eclipse software then automatically we can see eclipse version and workspace location like these pic below enter image description here

adb command for getting ip address assigned by operator

You also can try this:

Step 1: adb shell Step 2: ip -f inet addr show wlan0

maxlength ignored for input type="number" in Chrome

I was able archive it using this.

<input type="text" onkeydown="javascript: return event.keyCode === 8 || event.keyCode === 46 ? true : !isNaN(Number(event.key))" maxlength="4">

javascript - replace dash (hyphen) with a space

replace() returns an new string, and the original string is not modified. You need to do

str = str.replace(/-/g, ' ');

Decoding UTF-8 strings in Python

It's an encoding error - so if it's a unicode string, this ought to fix it:

text.encode("windows-1252").decode("utf-8")

If it's a plain string, you'll need an extra step:

text.decode("utf-8").encode("windows-1252").decode("utf-8")

Both of these will give you a unicode string.

By the way - to discover how a piece of text like this has been mangled due to encoding issues, you can use chardet:

>>> import chardet
>>> chardet.detect(u"And the Hip’s coming, too")
{'confidence': 0.5, 'encoding': 'windows-1252'}

Sum of two input value by jquery

Your code is correct, except you are adding (concatenating) strings, not adding integers. Just change your code into:

function compute() {
    if ( $('input[name=type]:checked').val() != undefined ) {
        var a = parseInt($('input[name=service_price]').val());
        var b = parseInt($('input[name=modem_price]').val());
        var total = a+b;
        $('#total_price').val(a+b);
    }
}

and this should work.

Here is some working example that updates the sum when the value when checkbox is checked (and if this is checked, the value is also updated when one of the fields is changed): jsfiddle.

How to change default text file encoding in Eclipse?

I was having the same problem when I received a html to put inside my project and rename it to .jsp. To solve the problem, I needed to what people above already said, that is, to change text encoding in Eclipse Preferences. However, before renaming the files to .jsp, it was necessary to include the following line in the beginning of each .html file:

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>

I believe this forced Eclipse to understand that it was necessary to change file encoding when I tried to rename .html to .jsp.

How to convert text column to datetime in SQL

In SQL Server , cast text as datetime

select cast('5/21/2013 9:45:48' as datetime)

Regular expression search replace in Sublime Text 2

By the way, in the question above:

For:

Hello, my name is bob

Find part:

my name is (\w)+

With replace part:

my name used to be \1

Would return:

Hello, my name used to be b

Change find part to:

my name is (\w+)

And replace will be what you expect:

Hello, my name used to be bob

While (\w)+ will match "bob", it is not the grouping you want for replacement.

Stop floating divs from wrapping

For me (using bootstrap), only thing that worked was setting display:absolute;z-index:1 on the last cell.

How to take keyboard input in JavaScript?

Use JQuery keydown event.

$(document).keypress(function(){
    if(event.which == 70){  //f
        console.log("You have payed respect");
    }
});

In JS; keyboard keys are identified by Javascript keycodes

What's the best visual merge tool for Git?

Beyond Compare 3, my favorite, has a merge functionality in the Pro edition. The good thing with its merge is that it let you see all 4 views: base, left, right, and merged result. It's somewhat less visual than P4V but way more than WinDiff. It integrates with many source control and works on Windows/Linux. It has many features like advanced rules, editions, manual alignment...

The Perforce Visual Client (P4V) is a free tool that provides one of the most explicit interface for merging (see some screenshots). Works on all major platforms. My main disappointement with that tool is its kind of "read-only" interface. You cannot edit manually the files and you cannot manually align.

PS: P4Merge is included in P4V. Perforce tries to make it a bit hard to get their tool without their client.

SourceGear Diff/Merge may be my second free tool choice. Check that merge screens-shot and you'll see it's has the 3 views at least.


Meld is a newer free tool that I'd prefer to SourceGear Diff/Merge: Now it's also working on most platforms (Windows/Linux/Mac) with the distinct advantage of natively supporting some source control like Git. So you can have some history diff on all files much simpler. The merge view (see screenshot) has only 3 panes, just like SourceGear Diff/Merge. This makes merging somewhat harder in complex cases.

PS: If one tool one day supports 5 views merging, this would really be awesome, because if you cherry-pick commits in Git you really have not one base but two. Two base, two changes, and one resulting merge.

curl.h no such file or directory

If after the installation curl-dev luarocks does not see the headers:

find /usr -name 'curl.h'
Example: /usr/include/x86_64-linux-gnu/curl/curl.h

luarocks install lua-cURL CURL_INCDIR=/usr/include/x86_64-linux-gnu/

How to read pdf file and write it to outputStream

import java.io.*;


public class FileRead {


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


        File f=new File("C:\\Documents and Settings\\abc\\Desktop\\abc.pdf");

        OutputStream oos = new FileOutputStream("test.pdf");

        byte[] buf = new byte[8192];

        InputStream is = new FileInputStream(f);

        int c = 0;

        while ((c = is.read(buf, 0, buf.length)) > 0) {
            oos.write(buf, 0, c);
            oos.flush();
        }

        oos.close();
        System.out.println("stop");
        is.close();

    }

}

The easiest way so far. Hope this helps.

How to show first commit by 'git log'?

git log --format="%h" | tail -1 gives you the commit hash (ie 0dd89fb), which you can feed into other commands, by doing something like

git diff `git log --format="%h" --after="1 day"| tail -1`..HEAD to view all the commits in the last day.

A column-vector y was passed when a 1d array was expected

I had the same problem. The problem was that the labels were in a column format while it expected it in a row. use np.ravel()

knn.score(training_set, np.ravel(training_labels))

Hope this solves it.

Check if an element is present in an array

Single line code.. will return true or false

!!(arr.indexOf("val")+1)

Generate an HTML Response in a Java Servlet

You need to have a doGet method as:

public void doGet(HttpServletRequest request,
        HttpServletResponse response)
throws IOException, ServletException
{
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();

    out.println("<html>");
    out.println("<head>");
    out.println("<title>Hola</title>");
    out.println("</head>");
    out.println("<body bgcolor=\"white\">");
    out.println("</body>");
    out.println("</html>");
}

You can see this link for a simple hello world servlet

How to check if a table exists in MS Access for vb macros

Access has some sort of system tables You can read about it a little here you can fire the folowing query to see if it exists ( 1 = it exists, 0 = it doesnt ;))

SELECT Count([MSysObjects].[Name]) AS [Count]
FROM MSysObjects
WHERE (((MSysObjects.Name)="TblObject") AND ((MSysObjects.Type)=1));

How do synchronized static methods work in Java and can I use it for loading Hibernate entities?

To address the question more generally...

Keep in mind that using synchronized on methods is really just shorthand (assume class is SomeClass):

synchronized static void foo() {
    ...
}

is the same as

static void foo() {
    synchronized(SomeClass.class) {
        ...
    }
}

and

synchronized void foo() {
    ...
}

is the same as

void foo() {
    synchronized(this) {
        ...
    }
}

You can use any object as the lock. If you want to lock subsets of static methods, you can

class SomeClass {
    private static final Object LOCK_1 = new Object() {};
    private static final Object LOCK_2 = new Object() {};
    static void foo() {
        synchronized(LOCK_1) {...}
    }
    static void fee() {
        synchronized(LOCK_1) {...}
    }
    static void fie() {
        synchronized(LOCK_2) {...}
    }
    static void fo() {
        synchronized(LOCK_2) {...}
    }
}

(for non-static methods, you would want to make the locks be non-static fields)

How to debug a Flask app

If you're using Visual Studio Code, replace

app.run(debug=True)

with

app.run()

It appears when turning on the internal debugger disables the VS Code debugger.

Sorting Values of Set

Use a SortedSet (TreeSet is the default one):

SortedSet<String> set=new TreeSet<String>();
set.add("12");
set.add("15");
set.add("5");
List<String> list=new ArrayList<String>(set);

No extra sorting code needed.

Oh, I see you want a different sort order. Supply a Comparator to the TreeSet:

new TreeSet<String>(Comparator.comparing(Integer::valueOf));

Now your TreeSet will sort Strings in numeric order (which implies that it will throw exceptions if you supply non-numeric strings)

Reference:

How to identify which columns are not "NA" per row in a matrix?

Try:

which( !is.na(p), arr.ind=TRUE)

Which I think is just as informative and probably more useful than the output you specified, But if you really wanted the list version, then this could be used:

> apply(p, 1, function(x) which(!is.na(x)) )
[[1]]
[1] 2 3

[[2]]
[1] 4 7

[[3]]
integer(0)

[[4]]
[1] 5

[[5]]
integer(0)

Or even with smushing together with paste:

lapply(apply(p, 1, function(x) which(!is.na(x)) ) , paste, collapse=", ")

The output from which function the suggested method delivers the row and column of non-zero (TRUE) locations of logical tests:

> which( !is.na(p), arr.ind=TRUE)
     row col
[1,]   1   2
[2,]   1   3
[3,]   2   4
[4,]   4   5
[5,]   2   7

Without the arr.ind parameter set to non-default TRUE, you only get the "vector location" determined using the column major ordering the R has as its convention. R-matrices are just "folded vectors".

> which( !is.na(p) )
[1]  6 11 17 24 32

addEventListener not working in IE8

You can use the below addEvent() function to add events for most things but note that for XMLHttpRequest if (el.attachEvent) will fail in IE8, because it doesn't support XMLHttpRequest.attachEvent() so you have to use XMLHttpRequest.onload = function() {} instead.

function addEvent(el, e, f) {
    if (el.attachEvent) {
        return el.attachEvent('on'+e, f);
    }
    else {
        return el.addEventListener(e, f, false);
    }
}

var ajax = new XMLHttpRequest();
ajax.onload = function(e) {
}

UTF-8 byte[] to String

You could use the methods described in this question (especially since you start off with an InputStream): Read/convert an InputStream to a String

In particular, if you don't want to rely on external libraries, you can try this answer, which reads the InputStream via an InputStreamReader into a char[] buffer and appends it into a StringBuilder.

Get request URL in JSP which is forwarded by Servlet

Same as @axtavt, but you can use also the RequestDispatcher constant.

request.getAttribute(RequestDispatcher.FORWARD_REQUEST_URI);

React Hooks useState() with Object

If anyone is searching for useState() hooks update for object

- Through Input

        const [state, setState] = useState({ fName: "", lName: "" });
        const handleChange = e => {
            const { name, value } = e.target;
            setState(prevState => ({
                ...prevState,
                [name]: value
            }));
        };

        <input
            value={state.fName}
            type="text"
            onChange={handleChange}
            name="fName"
        />
        <input
            value={state.lName}
            type="text"
            onChange={handleChange}
            name="lName"
        />
   ***************************

 - Through onSubmit or button click
    
        setState(prevState => ({
            ...prevState,
            fName: 'your updated value here'
         }));

Abstraction vs Encapsulation in Java

In simple words: You do abstraction when deciding what to implement. You do encapsulation when hiding something that you have implemented.

Extract regression coefficient values

Just pass your regression model into the following function:

    plot_coeffs <- function(mlr_model) {
      coeffs <- coefficients(mlr_model)
      mp <- barplot(coeffs, col="#3F97D0", xaxt='n', main="Regression Coefficients")
      lablist <- names(coeffs)
      text(mp, par("usr")[3], labels = lablist, srt = 45, adj = c(1.1,1.1), xpd = TRUE, cex=0.6)
    }

Use as follows:

model <- lm(Petal.Width ~ ., data = iris)

plot_coeffs(model)

enter image description here

How to specify table's height such that a vertical scroll bar appears?

Try using the overflow CSS property. There are also separate properties to define the behaviour of just horizontal overflow (overflow-x) and vertical overflow (overflow-y).

Since you only want the vertical scroll, try this:

table {
  height: 500px;
  overflow-y: scroll;
}

EDIT:

Apparently <table> elements don't respect the overflow property. This appears to be because <table> elements are not rendered as display: block by default (they actually have their own display type). You can force the overflow property to work by setting the <table> element to be a block type:

table {
  display: block;
  height: 500px;
  overflow-y: scroll;
}

Note that this will cause the element to have 100% width, so if you don't want it to take up the entire horizontal width of the page, you need to specify an explicit width for the element as well.

Room persistance library. Delete all

To make use of the Room without abuse of the @Query annotation first use @Query to select all rows and put them in a list, for example:

@Query("SELECT * FROM your_class_table")

List`<`your_class`>` load_all_your_class();

Put his list into the delete annotation, for example:

@Delete

void deleteAllOfYourTable(List`<`your_class`>` your_class_list);

How to set the maximum memory usage for JVM?

If you want to limit memory for jvm (not the heap size ) ulimit -v

To get an idea of the difference between jvm and heap memory , take a look at this excellent article http://blogs.vmware.com/apps/2011/06/taking-a-closer-look-at-sizing-the-java-process.html

Like Operator in Entity Framework?

I don't know anything about EF really, but in LINQ to SQL you usually express a LIKE clause using String.Contains:

where entity.Name.Contains("xyz")

translates to

WHERE Name LIKE '%xyz%'

(Use StartsWith and EndsWith for other behaviour.)

I'm not entirely sure whether that's helpful, because I don't understand what you mean when you say you're trying to implement LIKE. If I've misunderstood completely, let me know and I'll delete this answer :)

Applying CSS styles to all elements inside a DIV

If you're looking for a shortcut for writing out all of your selectors, then a CSS Preprocessor (Sass, LESS, Stylus, etc.) can do what you're looking for. However, the generated styles must be valid CSS.

Sass:

#applyCSS {
    .ui-bar-a {
       color: blue;
    }
    .ui-bar-a .ui-link-inherit {
       color: orange;
    }
    background: #CCC;
}

Generated CSS:

#applyCSS {
  background: #CCC;
}

#applyCSS .ui-bar-a {
  color: blue;
}

#applyCSS .ui-bar-a .ui-link-inherit {
  color: orange;
}

Avoid printStackTrace(); use a logger call instead

Almost every logging framework provides a method in which we can pass the throwable object along with a message. Like:

public trace(Marker marker, String msg, Throwable t);

They print the stacktrace of the throwable object.

Init array of structs in Go

You can have it this way:

It is important to mind the commas after each struct item or set of items.

earnings := []LineItemsType{

        LineItemsType{

            TypeName: "Earnings",

            Totals: 0.0,

            HasTotal: true,

            items: []LineItems{

                LineItems{

                    name: "Basic Pay",

                    amount: 100.0,
                },

                LineItems{

                    name: "Commuter Allowance",

                    amount: 100.0,
                },
            },
        },
        LineItemsType{

            TypeName: "Earnings",

            Totals: 0.0,

            HasTotal: true,

            items: []LineItems{

                LineItems{

                    name: "Basic Pay",

                    amount: 100.0,
                },

                LineItems{

                    name: "Commuter Allowance",

                    amount: 100.0,
                },
            },
        },
    }

How do I get the directory of the PowerShell script I execute?

PowerShell 3 has the $PSScriptRoot automatic variable:

Contains the directory from which a script is being run.

In Windows PowerShell 2.0, this variable is valid only in script modules (.psm1). Beginning in Windows PowerShell 3.0, it is valid in all scripts.

Don't be fooled by the poor wording. PSScriptRoot is the directory of the current file.

In PowerShell 2, you can calculate the value of $PSScriptRoot yourself:

# PowerShell v2
$PSScriptRoot = Split-Path -Parent -Path $MyInvocation.MyCommand.Definition

How to bring a window to the front?

Here's a method that REALLY works (tested on Windows Vista) :D

   frame.setExtendedState(JFrame.ICONIFIED);
   frame.setExtendedState(fullscreen ? JFrame.MAXIMIZED_BOTH : JFrame.NORMAL);

The fullscreen variable indicates if you want the app to run full screen or windowed.

This does not flash the task bar, but bring the window to front reliably.

Disable submit button on form submit

Disabled controls do not submit their values which does not help in knowing if the user clicked save or delete.

So I store the button value in a hidden which does get submitted. The name of the hidden is the same as the button name. I call all my buttons by the name of button.

E.g. <button type="submit" name="button" value="save">Save</button>

Based on this I found here. Just store the clicked button in a variable.

$(document).ready(function(){
    var submitButton$;

    $(document).on('click', ":submit", function (e)
    {
        // you may choose to remove disabled from all buttons first here.
        submitButton$ = $(this);
    });

    $(document).on('submit', "form", function(e)
    {
        var form$ = $(this);
        var hiddenButton$ = $('#button', form$);
        if (IsNull(hiddenButton$))
        {
            // add the hidden to the form as needed
            hiddenButton$ = $('<input>')
                .attr({ type: 'hidden', id: 'button', name: 'button' })
                .appendTo(form$);
        }
        hiddenButton$.attr('value', submitButton$.attr('value'));
        submitButton$.attr("disabled", "disabled");
    }
});

Here is my IsNull function. Use or substitue your own version for IsNull or undefined etc.

function IsNull(obj)
{
    var is;
    if (obj instanceof jQuery)
        is = obj.length <= 0;
    else
        is = obj === null || typeof obj === 'undefined' || obj == "";

    return is;
}

Java get month string from integer

DateFormatSymbols class provides methods for our ease use.

To get short month strings. For example: "Jan", "Feb", etc.

getShortMonths()

To get month strings. For example: "January", "February", etc.

getMonths()

Sample code to return month string in mmm format,

private static String getShortMonthFromNumber(int month){
    if(month<0 || month>11){
        return "";
    }
    return new DateFormatSymbols().getShortMonths()[month];
}

jQuery OR Selector?

Daniel A. White Solution works great for classes.

I've got a situation where I had to find input fields like donee_1_card where 1 is an index.

My solution has been

$("input[name^='donee']" && "input[name*='card']")

Though I am not sure how optimal it is.

How to find Google's IP address?

If all you are trying to do is find the IP address that corresponds to a domain name, like google.com, this is very easy on every machine connected to the Internet.

Simply run the ping command from any command prompt. Typing something like

ping google.com

will give you (among other things) that information.

How to format a duration in java? (e.g format H:MM:SS)

This is easier since Java 9. A Duration still isn’t formattable, but methods for getting the hours, minutes and seconds are added, which makes the task somewhat more straightforward:

    LocalDateTime start = LocalDateTime.of(2019, Month.JANUARY, 17, 15, 24, 12);
    LocalDateTime end = LocalDateTime.of(2019, Month.JANUARY, 18, 15, 43, 33);
    Duration diff = Duration.between(start, end);
    String hms = String.format("%d:%02d:%02d", 
                                diff.toHours(), 
                                diff.toMinutesPart(), 
                                diff.toSecondsPart());
    System.out.println(hms);

The output from this snippet is:

24:19:21

Execution Failed for task :app:compileDebugJavaWithJavac in Android Studio

Update (06/05/2017)

I wanted to use Realm for Android and that required Retrolambda. Problem is Retrolambda conflicts with Jack.

So I removed my Jack options config from my gradle shown in original answer below and made the following changes:

// ---------------------------------------------
// Project build.gradle file
// ---------------------------------------------
buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.1'
        classpath 'me.tatarka:gradle-retrolambda:3.6.1'
        classpath "io.realm:realm-gradle-plugin:3.1.4"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

and

// ---------------------------------------------
// Module build.gradle file
// ---------------------------------------------
apply plugin: 'com.android.application'
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'realm-android'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    ...

Tools.jar

If you made those changes above and you still get the following error:

Execution failed for task ':app:compileDebugJavaWithJavac'.
com.sun.tools.javac.util.Context.put(Ljava/lang/Class;Ljava/lang/Object;)V

Try removing the following file:

/Library/Java/Extensions/tools.jar 

Then:

  1. Quit emulator
  2. Quit Android Studio
  3. Reopen Android Studio
  4. Build > Clean Project
  5. Run/debug your app onto your device/emulator again

All the changes fixed it for me.

Note:

I am not sure what tools.jar does or whether it's important. Like other uses in this Stackoverflow question:

Can't build Java project on OSX yosemite

We were unfortunate enough to have to use AUSKey (some ancient dinosaur Java authentication key system used by Australian Government to authenticate our computer before we can log into Australian business portal website).

My speculation is tools.jar might have been a JAR file for/by AUSKey.

If you're worried, instead of deleting this file, you can make a backup of the whole folder and save it somewhere just in case you can't login to Australian Business Portal again.

Hope that helps :D

Original Answer

I came across this problem today (27/06/2016).

I downloaded Android Studio 2.2 and updated JDK to 1.8.

In addition to the above answers of pointing to the correct JDK path, I had to additionally specify the JDK version in my build.gradle(Module: app) file:

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

The resulting file looks like this:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.2"
    defaultConfig {
        applicationId "com.mycompany.appname"
        minSdkVersion 17
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

        jackOptions {
            enabled true
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    testCompile 'junit:junit:4.12'
}

Please also notice if you came across an error about Java 8 language features requires Jack enabled, you need to add the following to your gradle file (as shown above):

jackOptions {
    enabled true
}

After doing that, I finally got my new project app running on my phone.

How do I handle newlines in JSON?

You will need to have a function which replaces \n to \\n in case data is not a string literal.

function jsonEscape(str)  {
    return str.replace(/\n/g, "\\\\n").replace(/\r/g, "\\\\r").replace(/\t/g, "\\\\t");
}

var data = '{"count" : 1, "stack" : "sometext\n\n"}';
var dataObj = JSON.parse(jsonEscape(data));

Resulting dataObj will be

Object {count: 1, stack: "sometext\n\n"}

TimeStamp on file name using PowerShell

Thanks for the above script. One little modification to add in the file ending correctly. Try this ...

$filenameFormat = "MyFileName" + " " + (Get-Date -Format "yyyy-MM-dd") **+ ".txt"**

Rename-Item -Path "C:\temp\MyFileName.txt" -NewName $filenameFormat

Why are my PowerShell scripts not running?

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process

The above command worked for me even when the following error happens:

Access to the registry key 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell' is denied.

How to get the index of a maximum element in a NumPy array along one axis

argmax() will only return the first occurrence for each row. http://docs.scipy.org/doc/numpy/reference/generated/numpy.argmax.html

If you ever need to do this for a shaped array, this works better than unravel:

import numpy as np
a = np.array([[1,2,3], [4,3,1]])  # Can be of any shape
indices = np.where(a == a.max())

You can also change your conditions:

indices = np.where(a >= 1.5)

The above gives you results in the form that you asked for. Alternatively, you can convert to a list of x,y coordinates by:

x_y_coords =  zip(indices[0], indices[1])

Xcode - Warning: Implicit declaration of function is invalid in C99

The function has to be declared before it's getting called. This could be done in various ways:

  • Write down the prototype in a header
    Use this if the function shall be callable from several source files. Just write your prototype
    int Fibonacci(int number);
    down in a .h file (e.g. myfunctions.h) and then #include "myfunctions.h" in the C code.

  • Move the function before it's getting called the first time
    This means, write down the function
    int Fibonacci(int number){..}
    before your main() function

  • Explicitly declare the function before it's getting called the first time
    This is the combination of the above flavors: type the prototype of the function in the C file before your main() function

As an additional note: if the function int Fibonacci(int number) shall only be used in the file where it's implemented, it shall be declared static, so that it's only visible in that translation unit.

Can I change the color of Font Awesome's icon color?

HTML:

    <i class="icon-cog blackiconcolor">

css :

    .blackiconcolor {color:black;}

you can also add extra class to the button icon...

Cannot invoke an expression whose type lacks a call signature

I had the same issue with numeral, a JS library. The fix was to install the typings again with this command:

npm install --save @types/numeral

c++ string array initialization

Prior to C++11, you cannot initialise an array using type[]. However the latest c++11 provides(unifies) the initialisation, so you can do it in this way:

string* pStr = new string[3] { "hi", "there"};

See http://www2.research.att.com/~bs/C++0xFAQ.html#uniform-init

How do I use Wget to download all images into a single folder, from a URL?

wget -nd -r -l 2 -A jpg,jpeg,png,gif http://t.co
  • -nd: no directories (save all files to the current directory; -P directory changes the target directory)
  • -r -l 2: recursive level 2
  • -A: accepted extensions
wget -nd -H -p -A jpg,jpeg,png,gif -e robots=off example.tumblr.com/page/{1..2}
  • -H: span hosts (wget doesn't download files from different domains or subdomains by default)
  • -p: page requisites (includes resources like images on each page)
  • -e robots=off: execute command robotos=off as if it was part of .wgetrc file. This turns off the robot exclusion which means you ignore robots.txt and the robot meta tags (you should know the implications this comes with, take care).

Example: Get all .jpg files from an exemplary directory listing:

$ wget -nd -r -l 1 -A jpg http://example.com/listing/

How do I use 'git reset --hard HEAD' to revert to a previous commit?

WARNING: git clean -f will remove untracked files, meaning they're gone for good since they aren't stored in the repository. Make sure you really want to remove all untracked files before doing this.


Try this and see git clean -f.

git reset --hard will not remove untracked files, where as git-clean will remove any files from the tracked root directory that are not under Git tracking.

Alternatively, as @Paul Betts said, you can do this (beware though - that removes all ignored files too)

  • git clean -df
  • git clean -xdf CAUTION! This will also delete ignored files

.crx file install in chrome

Opening the debug console in Chrome, or even looking at the html source file (after it is loaded in the browser), make sure that all the paths there are valid (i.e. when you follow a link you get to it's content, and not an error). When something is not valid, fix the path (e.g. get rid of the server specific part and make sure you only refer to files that are part of your extension through paths like /js/jquery-123-min.js).

Android Studio: Where is the Compiler Error Output Window?

In my case i had a findViewById reference to a view i had deleted in xml

if you are running AS 3.1 and above:

  1. go to Settings > Build, Execution and Deployment > compiler
  2. add --stacktrace to the command line options, click apply and ok
  3. At the bottom of AS click on Console/Build(If you use the stable version 3.1.2 and above) expand the panel and run your app again.

you should see the full stacktrace in the expanded view and the specific error.

Updates were rejected because the tip of your current branch is behind its remote counterpart

Set current branch name like master

git pull --rebase origin master git push origin master

Or branch name develop

git pull --rebase origin develop git push origin develop

How to send a correct authorization header for basic authentication

If you are in a browser environment you can also use btoa.

btoa is a function which takes a string as argument and produces a Base64 encoded ASCII string. Its supported by 97% of browsers.

Example:

> "Basic " + btoa("billy"+":"+"secretpassword")
< "Basic YmlsbHk6c2VjcmV0cGFzc3dvcmQ="

You can then add Basic YmlsbHk6c2VjcmV0cGFzc3dvcmQ= to the authorization header.

Note that the usual caveats about HTTP BASIC auth apply, most importantly if you do not send your traffic over https an eavesdropped can simply decode the Base64 encoded string thus obtaining your password.

This security.stackexchange.com answer gives a good overview of some of the downsides.

Converting dd/mm/yyyy formatted string to Datetime

You need to use DateTime.ParseExact with format "dd/MM/yyyy"

DateTime dt=DateTime.ParseExact("24/01/2013", "dd/MM/yyyy", CultureInfo.InvariantCulture);

Its safer if you use d/M/yyyy for the format, since that will handle both single digit and double digits day/month. But that really depends if you are expecting single/double digit values.


Your date format day/Month/Year might be an acceptable date format for some cultures. For example for Canadian Culture en-CA DateTime.Parse would work like:

DateTime dt = DateTime.Parse("24/01/2013", new CultureInfo("en-CA"));

Or

System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-CA");
DateTime dt = DateTime.Parse("24/01/2013"); //uses the current Thread's culture

Both the above lines would work because the the string's format is acceptable for en-CA culture. Since you are not supplying any culture to your DateTime.Parse call, your current culture is used for parsing which doesn't support the date format. Read more about it at DateTime.Parse.


Another method for parsing is using DateTime.TryParseExact

DateTime dt;
if (DateTime.TryParseExact("24/01/2013", 
                            "d/M/yyyy", 
                            CultureInfo.InvariantCulture, 
                            DateTimeStyles.None,
    out dt))
{
    //valid date
}
else
{
    //invalid date
}

The TryParse group of methods in .Net framework doesn't throw exception on invalid values, instead they return a bool value indicating success or failure in parsing.

Notice that I have used single d and M for day and month respectively. Single d and M works for both single/double digits day and month. So for the format d/M/yyyy valid values could be:

  • "24/01/2013"
  • "24/1/2013"
  • "4/12/2013" //4 December 2013
  • "04/12/2013"

For further reading you should see: Custom Date and Time Format Strings

Why am I getting "(304) Not Modified" error on some links when using HttpWebRequest?

This is intended behavior.

When you make an HTTP request, the server normally returns code 200 OK. If you set If-Modified-Since, the server may return 304 Not modified (and the response will not have the content). This is supposed to be your cue that the page has not been modified.

The authors of the class have foolishly decided that 304 should be treated as an error and throw an exception. Now you have to clean up after them by catching the exception every time you try to use If-Modified-Since.

How to get the Enum Index value in C#

Firstly, there could be two values that you're referring to:

Underlying Value

If you are asking about the underlying value, which could be any of these types: byte, sbyte, short, ushort, int, uint, long or ulong

Then you can simply cast it to it's underlying type. Assuming it's an int, you can do it like this:

int eValue = (int)enumValue;

However, also be aware of each items default value (first item is 0, second is 1 and so on) and the fact that each item could have been assigned a new value, which may not necessarily be in any order particular order! (Credit to @JohnStock for the poke to clarify).

This example assigns each a new value, and show the value returned:

public enum MyEnum
{
    MyValue1 = 34,
    MyValue2 = 27
}

(int)MyEnum.MyValue2 == 27; // True

Index Value

The above is generally the most commonly required value, and is what your question detail suggests you need, however each value also has an index value (which you refer to in the title). If you require this then please see other answers below for details.

How to display both icon and title of action inside ActionBar?

You can add button in toolbar

<android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        app:popupTheme="@style/AppTheme.PopupOverlay"
        app:title="title">

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:layout_marginRight="16dp"
            android:background="@color/transparent"
            android:drawableRight="@drawable/ic_your_icon"
            android:drawableTint="@drawable/btn_selector"
            android:text="@string/sort_by_credit"
            android:textColor="@drawable/btn_selector"
            />

    </android.support.v7.widget.Toolbar>

create file btn_selector.xml in drawable

<?xml version="1.0" encoding="utf-8" ?>

<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item
    android:state_selected="true"
    android:color="@color/white"
    />
<item
    android:color="@color/white_30_opacity"
    />

java:

private boolean isSelect = false;

OnClickListener for button:

private void myClick() {
    if (!isSelect) {
       //**your code**//
        isSelect = true;
    } else {//**your code**//
        isSelect = false;
    }
    sort.setSelected(isSelect);
}

How can I format a String number to have commas and round?

Given this is the number one Google result for format number commas java, here's an answer that works for people who are working with whole numbers and don't care about decimals.

String.format("%,d", 2000000)

outputs:

2,000,000

Is it possible to append to innerHTML without destroying descendants' event listeners?

Yes it is possible if you bind events using tag attribute onclick="sayHi()" directly in template similar like your <body onload="start()"> - this approach similar to frameworks angular/vue/react/etc. You can also use <template> to operate on 'dynamic' html like here. It is not strict unobtrusive js however it is acceptable for small projects

_x000D_
_x000D_
function start() {_x000D_
  mydiv.innerHTML += "bar";_x000D_
}_x000D_
_x000D_
function sayHi() {_x000D_
  alert("hi");_x000D_
}
_x000D_
<body onload="start()">_x000D_
  <div id="mydiv" style="border: solid red 2px">_x000D_
    <span id="myspan" onclick="sayHi()">foo</span>_x000D_
  </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

How do you post to an iframe?

An iframe is used to embed another document inside a html page.

If the form is to be submitted to an iframe within the form page, then it can be easily acheived using the target attribute of the tag.

Set the target attribute of the form to the name of the iframe tag.

<form action="action" method="post" target="output_frame">
    <!-- input elements here --> 
</form>
<iframe name="output_frame" src="" id="output_frame" width="XX" height="YY">
</iframe>           

Advanced iframe target use
This property can also be used to produce an ajax like experience, especially in cases like file upload, in which case where it becomes mandatory to submit the form, in order to upload the files

The iframe can be set to a width and height of 0, and the form can be submitted with the target set to the iframe, and a loading dialog opened before submitting the form. So, it mocks a ajax control as the control still remains on the input form jsp, with the loading dialog open.

Exmaple

<script>
$( "#uploadDialog" ).dialog({ autoOpen: false, modal: true, closeOnEscape: false,                 
            open: function(event, ui) { jQuery('.ui-dialog-titlebar-close').hide(); } });

function startUpload()
{            
    $("#uploadDialog").dialog("open");
}

function stopUpload()
{            
    $("#uploadDialog").dialog("close");
}
</script>

<div id="uploadDialog" title="Please Wait!!!">
            <center>
            <img src="/imagePath/loading.gif" width="100" height="100"/>
            <br/>
            Loading Details...
            </center>
 </div>

<FORM  ENCTYPE="multipart/form-data" ACTION="Action" METHOD="POST" target="upload_target" onsubmit="startUpload()"> 
<!-- input file elements here--> 
</FORM>

<iframe id="upload_target" name="upload_target" src="#" style="width:0;height:0;border:0px solid #fff;" onload="stopUpload()">   
        </iframe>

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'id' in 'where clause' (SQL: select * from `songs` where `id` = 5 limit 1)

I am running laravel 5.8 and i experienced the same problem. The solution that worked for me is as follows :

  1. I used bigIncrements('id') to define my primary key.
  2. I used unsignedBigInteger('user_id') to define the foreign referenced key.

        Schema::create('generals', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('general_name');
            $table->string('status');
            $table->timestamps();
        });
    
    
        Schema::create('categories', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->unsignedBigInteger('general_id');
            $table->foreign('general_id')->references('id')->on('generals');
            $table->string('category_name');
            $table->string('status');
            $table->timestamps();
        });
    

I hope this helps out.

Common elements comparison between 2 lists

Set is another way we can solve this

a = [3,2,4]
b = [2,3,5]
set(a)&set(b)
{2, 3}

Javascript negative number

This is an old question but it has a lot of views so I think that is important to update it.

ECMAScript 6 brought the function Math.sign(), which returns the sign of a number (1 if it's positive, -1 if it's negative) or NaN if it is not a number. Reference

You could use it as:

var number = 1;

if(Math.sign(number) === 1){
    alert("I'm positive");
}else if(Math.sign(number) === -1){
    alert("I'm negative");
}else{
    alert("I'm not a number");
}

how to kill the tty in unix

for example kill pts/0

pkill -9 -t pts/0

Giving a border to an HTML table row, <tr>

_x000D_
_x000D_
<table cellpadding="0" cellspacing="0" width="100%" style="border: 1px;" rules="none">_x000D_
    <tbody>_x000D_
        <tr>_x000D_
            <th style="width: 96px;">Column 1</th>_x000D_
            <th style="width: 96px;">Column 2</th>_x000D_
            <th style="width: 96px;">Column 3</th>_x000D_
        </tr>_x000D_
_x000D_
        <tr>_x000D_
            <td>&nbsp;</td>_x000D_
            <td>&nbsp;</td>_x000D_
            <td>&nbsp;</td>_x000D_
        </tr>_x000D_
_x000D_
        <tr>_x000D_
            <td style="border-left: thin solid; border-top: thin solid; border-bottom: thin solid;">&nbsp;</td>_x000D_
            <td style="border-top: thin solid; border-bottom: thin solid;">&nbsp;</td>_x000D_
            <td style="border-top: thin solid; border-bottom: thin solid; border-right: thin solid;">&nbsp;</td>_x000D_
        </tr>_x000D_
_x000D_
        <tr>_x000D_
            <td>&nbsp;</td>_x000D_
            <td>&nbsp;</td>_x000D_
            <td>&nbsp;</td>_x000D_
        </tr>_x000D_
    </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Easy way to dismiss keyboard?

@Nicholas Riley & @Kendall Helmstetter Geln & @cannyboy:

Absolutely brilliant!

Thank you.

Considering your advice and the advice of others in this thread, this is what I've done:

What it looks like when used:

[[self appDelegate] dismissKeyboard]; (note: I added appDelegate as an addition to NSObject so I can use anywhere on anything)

What it looks like under the hood:

- (void)dismissKeyboard 
{
    UITextField *tempTextField = [[[UITextField alloc] initWithFrame:CGRectZero] autorelease];
    tempTextField.enabled = NO;
    [myRootViewController.view addSubview:tempTextField];
    [tempTextField becomeFirstResponder];
    [tempTextField resignFirstResponder];
    [tempTextField removeFromSuperview];
}

EDIT

Amendment to my answer to included tempTextField.enabled = NO;. Disabling the text field will prevent UIKeyboardWillShowNotification and UIKeyboardWillHideNotification keyboard notifications from being sent should you rely on these notifications throughout your app.

Pandas: rolling mean by time interval

visualize the rolling averages to see if it makes sense. I don't understand why sum was used when the rolling average was requested.

  df=pd.read_csv('poll.csv',parse_dates=['enddate'],dtype={'favorable':np.float,'unfavorable':np.float,'other':np.float})

  df.set_index('enddate')
  df=df.fillna(0)

 fig, axs = plt.subplots(figsize=(5,10))
 df.plot(x='enddate', ax=axs)
 plt.show()


 df.rolling(window=3,min_periods=3).mean().plot()
 plt.show()
 print("The larger the window coefficient the smoother the line will appear")
 print('The min_periods is the minimum number of observations in the window required to have a value')

 df.rolling(window=6,min_periods=3).mean().plot()
 plt.show()

Remove first Item of the array (like popping from stack)

The easiest way is using shift(). If you have an array, the shift function shifts everything to the left.

var arr = [1, 2, 3, 4]; 
var theRemovedElement = arr.shift(); // theRemovedElement == 1
console.log(arr); // [2, 3, 4]

How to read a file line-by-line into a list?

If you want to are faced with a very large / huge file and want to read faster (imagine you are in a Topcoder/Hackerrank coding competition), you might read a considerably bigger chunk of lines into a memory buffer at one time, rather than just iterate line by line at file level.

buffersize = 2**16
with open(path) as f: 
    while True:
        lines_buffer = f.readlines(buffersize)
        if not lines_buffer:
            break
        for line in lines_buffer:
            process(line)

How to set opacity in parent div and not affect in child div?

You can't. Css today simply doesn't allow that.

The logical rendering model is this one :

If the object is a container element, then the effect is as if the contents of the container element were blended against the current background using a mask where the value of each pixel of the mask is .

Reference : css transparency

The solution is to use a different element composition, usually using fixed or computed positions for what is today defined as a child : it may appear logically and visualy for the user as a child but the element doesn't need to be really a child in your code.

A solution using css : fiddle

.parent {
    width:500px;
    height:200px;    
    background-image:url('http://canop.org/blog/wp-content/uploads/2011/11/cropped-bandeau-cr%C3%AAte-011.jpg');
    opacity: 0.2;
}
.child {
    position: fixed;
    top:0;
}

Another solution with javascript : fiddle

Where does application data file actually stored on android device?

Application Private Data files are stored within <internal_storage>/data/data/<package>

Files being stored in the internal storage can be accessed with openFileOutput() and openFileInput()

When those files are created as MODE_PRIVATE it is not possible to see/access them within another application such as a FileManager.

How to get box-shadow on left & right sides only

In some situations you can hide the shadow by another container. Eg, if there is a DIV above and below the DIV with the shadow, you can use position: relative; z-index: 1; on the surrounding DIVs.

Finding the type of an object in C++

As others indicated you can use dynamic_cast. But generally using dynamic_cast for finding out the type of the derived class you are working upon indicates the bad design. If you are overriding a function that takes pointer of A as the parameter then it should be able to work with the methods/data of class A itself and should not depend on the the data of class B. In your case instead of overriding if you are sure that the method you are writing will work with only class B, then you should write a new method in class B.

Plotting of 1-dimensional Gaussian distribution function

In addition to previous answers, I recommend to first calculate the ratio in the exponent, then taking the square:

def gaussian(x,x0,sigma):
  return np.exp(-np.power((x - x0)/sigma, 2.)/2.)

That way, you can also calculate the gaussian of very small or very large numbers:

In: gaussian(1e-12,5e-12,3e-12)
Out: 0.64118038842995462

What is the correct way to free memory in C#

The .NET garbage collector takes care of all this for you.

It is able to determine when objects are no longer referenced and will (eventually) free the memory that had been allocated to them.

How to use ng-repeat for dictionaries in AngularJs?

JavaScript developers tend to refer to the above data-structure as either an object or hash instead of a Dictionary.

Your syntax above is wrong as you are initializing the users object as null. I presume this is a typo, as the code should read:

// Initialize users as a new hash.
var users = {};
users["182982"] = "...";

To retrieve all the values from a hash, you need to iterate over it using a for loop:

function getValues (hash) {
    var values = [];
    for (var key in hash) {

        // Ensure that the `key` is actually a member of the hash and not
        // a member of the `prototype`.
        // see: http://javascript.crockford.com/code.html#for%20statement
        if (hash.hasOwnProperty(key)) {
            values.push(key);
        }
    }
    return values;
};

If you plan on doing a lot of work with data-structures in JavaScript then the underscore.js library is definitely worth a look. Underscore comes with a values method which will perform the above task for you:

var values = _.values(users);

I don't use Angular myself, but I'm pretty sure there will be a convenience method build in for iterating over a hash's values (ah, there we go, Artem Andreev provides the answer above :))

libaio.so.1: cannot open shared object file

I had to do the following (in Kubuntu 16.04.3):

  1. Install the libraries: sudo apt-get install libaio1 libaio-dev
  2. Find where the library is installed: sudo find / -iname 'libaio.a' -type f --> resulted in /usr/lib/x86_64-linux-gnu/libaio.a
  3. Add result to environment variable: export LD_LIBRARY_PATH="/usr/lib/oracle/12.2/client64/lib:/usr/lib/x86_64-linux-gnu"

What is a "web service" in plain English?

A web service differs from a web site in that a web service provides information consumable by software rather than humans. As a result, we are usually talking about exposed JSON, XML, or SOAP services.

Web services are a key component in "mashups". Mashups are when information from many websites is automatically aggregated into a new and useful service. For example, there are sites that aggregate Google Maps with information about police reports to give you a graphical representation of crime in your area. Another type of mashup would be to take real stock data provided by another site and combine it with a fake trading application to create a stock-market "game".

Web services are also used to provide news (see RSS), latest items added to a site, information on new products, podcasts, and other great features that make the modern web turn.

Hope this helps!

Why do I need to configure the SQL dialect of a data source?

Dialect is the SQL dialect that your database uses.

List of SQL dialects for Hibernate.

Either provide it in hibernate.cfg.xml as :

<hibernate-configuration>
   <session-factory name="session-factory">
      <property name="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</property>
       ...
   </session-factory>
</hibernate-configuration>

or in the properties file as :

hibernate.dialect=org.hibernate.dialect.SQLServerDialect

Use a JSON array with objects with javascript

@Swapnil Godambe It works for me if JSON.stringfy is removed. That is:

$(jQuery.parseJSON(dataArray)).each(function() {  
    var ID = this.id;
    var TITLE = this.Title;
});

Image UriSource and Data Binding

The problem with the answer that was chosen here is that when navigating back and forth, the converter will get triggered every time the page is shown.

This causes new file handles to be created continuously and will block any attempt to delete the file because it is still in use. This can be verified by using Process Explorer.

If the image file might be deleted at some point, a converter such as this might be used: using XAML to bind to a System.Drawing.Image into a System.Windows.Image control

The disadvantage with this memory stream method is that the image(s) get loaded and decoded every time and no caching can take place: "To prevent images from being decoded more than once, assign the Image.Source property from an Uri rather than using memory streams" Source: "Performance tips for Windows Store apps using XAML"

To solve the performance issue, the repository pattern can be used to provide a caching layer. The caching could take place in memory, which may cause memory issues, or as thumbnail files that reside in a temp folder that can be cleared when the app exits.

How to get the position of a character in Python?

>>> s="mystring"
>>> s.index("r")
4
>>> s.find("r")
4

"Long winded" way

>>> for i,c in enumerate(s):
...   if "r"==c: print i
...
4

to get substring,

>>> s="mystring"
>>> s[4:10]
'ring'

How to add local jar files to a Maven project?

  1. Create a local Maven repository directory, Your project root should look something like this to start with:
yourproject
+- pom.xml
+- src
  1. Add a standard Maven repository directory called repo for the group com.example and version 1.0:
yourproject
+- pom.xml
+- src
+- repo
  1. Deploy the Artifact Into the Repo, Maven can deploy the artifact for you using the mvn deploy:deploy-file goal:
mvn deploy:deploy-file -Durl=file:///pathtoyour/repo -Dfile=your.jar -DgroupId=your.group.id -DartifactId=yourid -Dpackaging=jar -Dversion=1.0
  1. install pom file corresponding to your jar so that your project can find jar during maven build from local repo:
mvn install:install-file -Dfile=/path-to-your-jar-1.0.jar -DpomFile=/path-to-your-pom-1.0.pom
  1. add repo in your pom file:
<repositories>
    <!--other repositories if any-->
    <repository>
        <id>project.local</id>
        <name>project</name>
        <url>file:${project.basedir}/repo</url>
    </repository>
</repositories>
  1. add the dependency in your pom:
<dependency>
    <groupId>com.groupid</groupId>
    <artifactId>myid</artifactId>
    <version>1.0</version>
</dependency>

How to insert a timestamp in Oracle?

CREATE TABLE Table1 (
id int identity(1, 1) NOT NULL,
Somecolmn varchar (5),
LastChanged [timestamp] NOT NULL)

this works for mssql 2012

INSERT INTO Table1 VALUES('hello',DEFAULT)  

How to see docker image contents

docker save nginx > nginx.tar
tar -xvf nginx.tar

Following files are present:

  • manifest.json – Describes filesystem layers and name of json file that has the Container properties.
  • .json – Container properties
  • – Each “layerid” directory contains json file describing layer property and filesystem associated with that layer. Docker stores Container images as layers to optimize storage space by reusing layers across images.

https://sreeninet.wordpress.com/2016/06/11/looking-inside-container-images/

OR

you can use dive to view the image content interactively with TUI

enter image description here

https://github.com/wagoodman/dive

C# send a simple SSH command

I used SSH.Net in a project a while ago and was very happy with it. It also comes with a good documentation with lots of samples on how to use it.

The original package website can be still found here, including the documentation (which currently isn't available on GitHub).

For your case the code would be something like this.

using (var client = new SshClient("hostnameOrIp", "username", "password"))
{
    client.Connect();
    client.RunCommand("etc/init.d/networking restart");
    client.Disconnect();
}

How can I capitalize the first letter of each word in a string using JavaScript?

_x000D_
_x000D_
let cap = (str) => {_x000D_
  let arr = str.split(' ');_x000D_
  arr.forEach(function(item, index) {_x000D_
    arr[index] = item.replace(item[0], item[0].toUpperCase());_x000D_
  });_x000D_
_x000D_
  return arr.join(' ');_x000D_
};_x000D_
_x000D_
console.log(cap("I'm a little tea pot"));
_x000D_
_x000D_
_x000D_

Fast Readable Version see benchmark http://jsben.ch/k3JVz enter image description here

Connecting PostgreSQL 9.2.1 with Hibernate

If the project is maven placed it in src/main/resources, in the package phase it will copy it in ../WEB-INF/classes/hibernate.cfg.xml

Sending email in .NET through Gmail

Here is my version: "Send Email In C # Using Gmail".

using System;
using System.Net;
using System.Net.Mail;

namespace SendMailViaGmail
{
   class Program
   {
   static void Main(string[] args)
   {

      //Specify senders gmail address
      string SendersAddress = "[email protected]";
      //Specify The Address You want to sent Email To(can be any valid email address)
      string ReceiversAddress = "[email protected]";
      //Specify The password of gmial account u are using to sent mail(pw of [email protected])
      const string SendersPassword = "Password";
      //Write the subject of ur mail
      const string subject = "Testing";
      //Write the contents of your mail
      const string body = "Hi This Is my Mail From Gmail";

      try
      {
        //we will use Smtp client which allows us to send email using SMTP Protocol
        //i have specified the properties of SmtpClient smtp within{}
        //gmails smtp server name is smtp.gmail.com and port number is 587
        SmtpClient smtp = new SmtpClient
        {
           Host = "smtp.gmail.com",
           Port = 587,
           EnableSsl = true,
           DeliveryMethod = SmtpDeliveryMethod.Network,
           Credentials    = new NetworkCredential(SendersAddress, SendersPassword),
           Timeout = 3000
        };

        //MailMessage represents a mail message
        //it is 4 parameters(From,TO,subject,body)

        MailMessage message = new MailMessage(SendersAddress, ReceiversAddress, subject, body);
        /*WE use smtp sever we specified above to send the message(MailMessage message)*/

        smtp.Send(message);
        Console.WriteLine("Message Sent Successfully");
        Console.ReadKey();
     }

     catch (Exception ex)
     {
        Console.WriteLine(ex.Message);
        Console.ReadKey();
     }
    }
   }
 }

Is there a link to the "latest" jQuery library on Google APIs?

Up until jQuery 1.11.1, you could use the following URLs to get the latest version of jQuery:

For example:

<script src="https://code.jquery.com/jquery-latest.min.js"></script>

However, since jQuery 1.11.1, both jQuery and Google stopped updating these URL's; they will forever be fixed at 1.11.1. There is no supported alternative URL to use. For an explanation of why this is the case, see this blog post; Don't use jquery-latest.js.

Both hosts support https as well as http, so change the protocol as you see fit (or use a protocol relative URI)

See also: https://developers.google.com/speed/libraries/devguide

Python string class like StringBuilder in C#?

There is no explicit analogue - i think you are expected to use string concatenations(likely optimized as said before) or third-party class(i doubt that they are a lot more efficient - lists in python are dynamic-typed so no fast-working char[] for buffer as i assume). Stringbuilder-like classes are not premature optimization because of innate feature of strings in many languages(immutability) - that allows many optimizations(for example, referencing same buffer for slices/substrings). Stringbuilder/stringbuffer/stringstream-like classes work a lot faster than concatenating strings(producing many small temporary objects that still need allocations and garbage collection) and even string formatting printf-like tools, not needing of interpreting formatting pattern overhead that is pretty consuming for a lot of format calls.

How can Print Preview be called from Javascript?

It can be done using javascript. Say your html/aspx code goes this way:

<span>Main heading</span>
<asp:Label ID="lbl1" runat="server" Text="Contents"></asp:Label>
<asp:Label Text="Contractor Name" ID="lblCont" runat="server"></asp:Label>
<div id="forPrintPreview">
  <asp:Label Text="Company Name" runat="server"></asp:Label>
  <asp:GridView runat="server">

      //GridView Content goes here

  </asp:GridView
</div>

<input type="button" onclick="PrintPreview();" value="Print Preview" />

Here on click of "Print Preview" button we will open a window with data for print. Observe that 'forPrintPreview' is the id of a div. The function for Print preview goes this way:

function PrintPreview() {
 var Contractor= $('span[id*="lblCont"]').html();
 printWindow = window.open("", "", "location=1,status=1,scrollbars=1,width=650,height=600");
 printWindow.document.write('<html><head>');
 printWindow.document.write('<style type="text/css">@media print{.no-print, .no-print *{display: none !important;}</style>');
 printWindow.document.write('</head><body>');
 printWindow.document.write('<div style="width:100%;text-align:right">');

  //Print and cancel button
 printWindow.document.write('<input type="button" id="btnPrint" value="Print" class="no-print" style="width:100px" onclick="window.print()" />');
 printWindow.document.write('<input type="button" id="btnCancel" value="Cancel" class="no-print"  style="width:100px" onclick="window.close()" />');

 printWindow.document.write('</div>');

 //You can include any data this way.
 printWindow.document.write('<table><tr><td>Contractor name:'+ Contractor +'</td></tr>you can include any info here</table');

 printWindow.document.write(document.getElementById('forPrintPreview').innerHTML);
 //here 'forPrintPreview' is the id of the 'div' in current page(aspx).
 printWindow.document.write('</body></html>');
 printWindow.document.close();
 printWindow.focus();
}

Observe that buttons 'print' and 'cancel' has the css class 'no-print', So these buttons will not appear in the print.

How to convert java.util.Date to java.sql.Date?

Converting java.util.Data to java.sql.Data will loose hour, minute and second. So if it is possible, I suggest you use java.sql.Timestamp like this:

prepareStatement.setTimestamp(1, new Timestamp(utilDate.getTime()));

For more info, you can check this question.

Android studio- "SDK tools directory is missing"

It was mentioned before but to be clear, It probably is due to your internet connection.

In my case it was that in my job I am behind a proxy, that means I should set a proxy in android studio for it to be able to download all SDK files.

You can set a proxy in the Android Studio Settings under Appearance & Behavior > System Settings > HTTP Proxy as stated here: https://developer.android.com/studio/intro/studio-config#proxy

Test de proxy (there's a button for that). Close Android Studio. Reopen Android Studio, and it should be able to download all SDK files.

How do I modify the URL without reloading the page?

The HTML5 replaceState is the answer, as already mentioned by Vivart and geo1701. However it is not supported in all browsers/versions. History.js wraps HTML5 state features and provides additional support for HTML4 browsers.

Could not connect to Redis at 127.0.0.1:6379: Connection refused with homebrew

It's the better way to connect to your redis.

At first, check the ip address of redis server like this.

ps -ef | grep redis

The result is kind of " redis 1184 1 0 .... /usr/bin/redis-server 172.x.x.x:6379

And then you can connect to redis with -h(hostname) option like this.

redis-cli -h 172.x.x.x

Mockito : doAnswer Vs thenReturn

You should use thenReturn or doReturn when you know the return value at the time you mock a method call. This defined value is returned when you invoke the mocked method.

thenReturn(T value) Sets a return value to be returned when the method is called.

@Test
public void test_return() throws Exception {
    Dummy dummy = mock(Dummy.class);
    int returnValue = 5;

    // choose your preferred way
    when(dummy.stringLength("dummy")).thenReturn(returnValue);
    doReturn(returnValue).when(dummy).stringLength("dummy");
}

Answer is used when you need to do additional actions when a mocked method is invoked, e.g. when you need to compute the return value based on the parameters of this method call.

Use doAnswer() when you want to stub a void method with generic Answer.

Answer specifies an action that is executed and a return value that is returned when you interact with the mock.

@Test
public void test_answer() throws Exception {
    Dummy dummy = mock(Dummy.class);
    Answer<Integer> answer = new Answer<Integer>() {
        public Integer answer(InvocationOnMock invocation) throws Throwable {
            String string = invocation.getArgumentAt(0, String.class);
            return string.length() * 2;
        }
    };

    // choose your preferred way
    when(dummy.stringLength("dummy")).thenAnswer(answer);
    doAnswer(answer).when(dummy).stringLength("dummy");
}