Programs & Examples On #Rgb

RGB stands for Red-Green-Blue and specifies a color using three values, which represent the respective amount of red, green, and blue in the color. RGB is the basis for the color model used by most color display devices nowadays.

Get pixel's RGB using PIL

GIFs store colors as one of x number of possible colors in a palette. Read about the gif limited color palette. So PIL is giving you the palette index, rather than the color information of that palette color.

Edit: Removed link to a blog post solution that had a typo. Other answers do the same thing without the typo.

Hex colors: Numeric representation for "transparent"?

You can use this conversion table: http://roselab.jhu.edu/~raj/MISC/hexdectxt.html

eg, if you want a transparency of 60%, you use 3C (hex equivalent).

This is usefull for IE background gradient transparency:

filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#3C545454, endColorstr=#3C545454);
-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#3C545454, endColorstr=#3C545454)";

where startColorstr and endColorstr: 2 first characters are a hex value for transparency, and the six remaining are the hex color.

RGB to hex and hex to RGB

Shorthand version that accepts a string:

_x000D_
_x000D_
function rgbToHex(a){_x000D_
  a=a.replace(/[^\d,]/g,"").split(","); _x000D_
  return"#"+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1)_x000D_
}_x000D_
_x000D_
document.write(rgbToHex("rgb(255,255,255)"));
_x000D_
_x000D_
_x000D_

To check if it's not already hexadecimal

_x000D_
_x000D_
function rgbToHex(a){_x000D_
  if(~a.indexOf("#"))return a;_x000D_
  a=a.replace(/[^\d,]/g,"").split(","); _x000D_
  return"#"+((1<<24)+(+a[0]<<16)+(+a[1]<<8)+ +a[2]).toString(16).slice(1)_x000D_
}_x000D_
_x000D_
document.write("rgb: "+rgbToHex("rgb(255,255,255)")+ " -- hex: "+rgbToHex("#e2e2e2"));
_x000D_
_x000D_
_x000D_

Formula to determine brightness of RGB color

Here's a bit of C code that should properly calculate perceived luminance.

// reverses the rgb gamma
#define inverseGamma(t) (((t) <= 0.0404482362771076) ? ((t)/12.92) : pow(((t) + 0.055)/1.055, 2.4))

//CIE L*a*b* f function (used to convert XYZ to L*a*b*)  http://en.wikipedia.org/wiki/Lab_color_space
#define LABF(t) ((t >= 8.85645167903563082e-3) ? powf(t,0.333333333333333) : (841.0/108.0)*(t) + (4.0/29.0))


float
rgbToCIEL(PIXEL p)
{
   float y;
   float r=p.r/255.0;
   float g=p.g/255.0;
   float b=p.b/255.0;

   r=inverseGamma(r);
   g=inverseGamma(g);
   b=inverseGamma(b);

   //Observer = 2°, Illuminant = D65 
   y = 0.2125862307855955516*r + 0.7151703037034108499*g + 0.07220049864333622685*b;

   // At this point we've done RGBtoXYZ now do XYZ to Lab

   // y /= WHITEPOINT_Y; The white point for y in D65 is 1.0

    y = LABF(y);

   /* This is the "normal conversion which produces values scaled to 100
    Lab.L = 116.0*y - 16.0;
   */
   return(1.16*y - 0.16); // return values for 0.0 >=L <=1.0
}

Why rgb and not cmy?

The basic colours are RGB not RYB. Yes most of the softwares use the traditional RGB which can be used to mix together to form any other color i.e. RGB are the fundamental colours (as defined in Physics & Chemistry texts).

The printer user CMYK (cyan, magenta, yellow, and black) coloring as said by @jcomeau_ictx. You can view the following article to know about RGB vs CMYK: RGB Vs CMYK

A bit more information from the extract about them:

Red, Green, and Blue are "additive colors". If we combine red, green and blue light you will get white light. This is the principal behind the T.V. set in your living room and the monitor you are staring at now. Additive color, or RGB mode, is optimized for display on computer monitors and peripherals, most notably scanning devices.

Cyan, Magenta and Yellow are "subtractive colors". If we print cyan, magenta and yellow inks on white paper, they absorb the light shining on the page. Since our eyes receive no reflected light from the paper, we perceive black... in a perfect world! The printing world operates in subtractive color, or CMYK mode.

How do I write a RGB color value in JavaScript?

I am showing with an example of adding random color. You can write this way

var r = Math.floor(Math.random() * 255);
var g = Math.floor(Math.random() * 255);
var b = Math.floor(Math.random() * 255);
var col = "rgb(" + r + "," + g + "," + b + ")";
parent.childNodes[1].style.color = col;

The property is expected as a string

How to compare two colors for similarity/difference

I've tried various methods like LAB color space, HSV comparisons and I've found that luminosity works pretty well for this purpose.

Here is Python version

def lum(c):
    def factor(component):
        component = component / 255;
        if (component <= 0.03928):
            component = component / 12.92;
        else:
            component = math.pow(((component + 0.055) / 1.055), 2.4);

        return component
    components = [factor(ci) for ci in c]

    return (components[0] * 0.2126 + components[1] * 0.7152 + components[2] * 0.0722) + 0.05;

def color_distance(c1, c2):

    l1 = lum(c1)
    l2 = lum(c2)
    higher = max(l1, l2)
    lower = min(l1, l2)

    return (higher - lower) / higher


c1 = ImageColor.getrgb('white')
c2 = ImageColor.getrgb('yellow')
print(color_distance(c1, c2))

Will give you

0.0687619047619048

Convert System.Drawing.Color to RGB and Hex Value

You could keep it simple and use the native color translator:

Color red = ColorTranslator.FromHtml("#FF0000");
string redHex = ColorTranslator.ToHtml(red);

Then break the three color pairs into integer form:

int value = int.Parse(hexValue, System.Globalization.NumberStyles.HexNumber);

Given an RGB value, how do I create a tint (or shade)?

Some definitions

  • A shade is produced by "darkening" a hue or "adding black"
  • A tint is produced by "ligthening" a hue or "adding white"

Creating a tint or a shade

Depending on your Color Model, there are different methods to create a darker (shaded) or lighter (tinted) color:

  • RGB:

    • To shade:

      newR = currentR * (1 - shade_factor)
      newG = currentG * (1 - shade_factor)
      newB = currentB * (1 - shade_factor)
      
    • To tint:

      newR = currentR + (255 - currentR) * tint_factor
      newG = currentG + (255 - currentG) * tint_factor
      newB = currentB + (255 - currentB) * tint_factor
      
    • More generally, the color resulting in layering a color RGB(currentR,currentG,currentB) with a color RGBA(aR,aG,aB,alpha) is:

      newR = currentR + (aR - currentR) * alpha
      newG = currentG + (aG - currentG) * alpha
      newB = currentB + (aB - currentB) * alpha
      

    where (aR,aG,aB) = black = (0,0,0) for shading, and (aR,aG,aB) = white = (255,255,255) for tinting

  • HSV or HSB:

    • To shade: lower the Value / Brightness or increase the Saturation
    • To tint: lower the Saturation or increase the Value / Brightness
  • HSL:
    • To shade: lower the Lightness
    • To tint: increase the Lightness

There exists formulas to convert from one color model to another. As per your initial question, if you are in RGB and want to use the HSV model to shade for example, you can just convert to HSV, do the shading and convert back to RGB. Formula to convert are not trivial but can be found on the internet. Depending on your language, it might also be available as a core function :

Comparing the models

  • RGB has the advantage of being really simple to implement, but:
    • you can only shade or tint your color relatively
    • you have no idea if your color is already tinted or shaded
  • HSV or HSB is kind of complex because you need to play with two parameters to get what you want (Saturation & Value / Brightness)
  • HSL is the best from my point of view:
    • supported by CSS3 (for webapp)
    • simple and accurate:
      • 50% means an unaltered Hue
      • >50% means the Hue is lighter (tint)
      • <50% means the Hue is darker (shade)
    • given a color you can determine if it is already tinted or shaded
    • you can tint or shade a color relatively or absolutely (by just replacing the Lightness part)

Converting RGB to grayscale/intensity

is all this really necessary, human perception and CRT vs LCD will vary, but the R G B intensity does not, Why not L = (R + G + B)/3 and set the new RGB to L, L, L?

HSL to RGB color conversion

For all who said that Garry Tan solution converting incorrect from RGB to HSL and back. It because he left out fraction part of number in his code. I corrected his code (javascript). Sorry for link on russian languadge, but on english absent - HSL-wiki

function toHsl(r, g, b)
{
    r /= 255.0;
    g /= 255.0;
    b /= 255.0;
    var max = Math.max(r, g, b);
    var min = Math.min(r, g, b);
    var h, s, l = (max + min) / 2.0;

    if(max == min)
    {
        h = s = 0; 
    }
    else
    {
        var d = max - min;
        s = (l > 0.5 ? d / (2.0 - max - min) : d / (max + min));

        if(max == r && g >= b)
        {
            h = 1.0472 * (g - b) / d ;
        }
        else if(max == r && g < b)
        {
            h = 1.0472 * (g - b) / d + 6.2832;
        }
        else if(max == g)
        {
            h = 1.0472 * (b - r) / d + 2.0944;
        }
        else if(max == b)
        {
            h = 1.0472 * (r - g) / d + 4.1888;
        }
    }
    return {
        str: 'hsl(' + parseInt(h / 6.2832 * 360.0 + 0.5) + ',' + parseInt(s * 100.0 + 0.5) + '%,' + parseInt(l * 100.0 + 0.5) + '%)',
        obj: { h: parseInt(h / 6.2832 * 360.0 + 0.5), s: parseInt(s * 100.0 + 0.5), l: parseInt(l * 100.0 + 0.5) }
    };
};

What are the RGB codes for the Conditional Formatting 'Styles' in Excel?

For anyone who stumbles across this in the future, this is how you do it:

xl.Range("A1:A1").Style := "Bad"
xl.Range("A1:A1").Style := "Good"
xl.Range("A1:A1").Style := "Neutral"

An easy way to check on things like this is to open excel and record a macro. In this case I recorded a macro where I just formatted the cell to "Bad". Once you've recorded the macro, just go in and edit it and it will essentially give you the code. It will require a little translation on your part, but here is what the macro looks like when I edit it:

 Selection.Style = "Bad"

As you can see, it's pretty easy to make the jump to AHK from what excel provides.

How to read the RGB value of a given pixel in Python?

PyPNG - lightweight PNG decoder/encoder

Although the question hints at JPG, I hope my answer will be useful to some people.

Here's how to read and write PNG pixels using PyPNG module:

import png, array

point = (2, 10) # coordinates of pixel to be painted red

reader = png.Reader(filename='image.png')
w, h, pixels, metadata = reader.read_flat()
pixel_byte_width = 4 if metadata['alpha'] else 3
pixel_position = point[0] + point[1] * w
new_pixel_value = (255, 0, 0, 0) if metadata['alpha'] else (255, 0, 0)
pixels[
  pixel_position * pixel_byte_width :
  (pixel_position + 1) * pixel_byte_width] = array.array('B', new_pixel_value)

output = open('image-with-red-dot.png', 'wb')
writer = png.Writer(w, h, **metadata)
writer.write_array(output, pixels)
output.close()

PyPNG is a single pure Python module less than 4000 lines long, including tests and comments.

PIL is a more comprehensive imaging library, but it's also significantly heavier.

Set background colour of cell to RGB value of data in cell

Sub AddColor()
    For Each cell In Selection
        R = Round(cell.Value)
        G = Round(cell.Offset(0, 1).Value)
        B = Round(cell.Offset(0, 2).Value)
        Cells(cell.Row, 1).Resize(1, 4).Interior.Color = RGB(R, G, B)
    Next cell
End Sub

Assuming that there are 3 columns R, G and B (in this order). Select first column ie R. press alt+F11 and run the above code. We have to select the first column (containing R or red values) and run the code every time we change the values to reflect the changes.

I hope this simpler code helps !

libpng warning: iCCP: known incorrect sRGB profile

Thanks to the fantastic answer from Glenn, I used ImageMagik's "mogrify *.png" functionality. However, I had images buried in sub-folders, so I used this simple Python script to apply this to all images in all sub-folders and thought it might help others:

import os
import subprocess

def system_call(args, cwd="."):
    print("Running '{}' in '{}'".format(str(args), cwd))
    subprocess.call(args, cwd=cwd)
    pass

def fix_image_files(root=os.curdir):
    for path, dirs, files in os.walk(os.path.abspath(root)):
        # sys.stdout.write('.')
        for dir in dirs:
            system_call("mogrify *.png", "{}".format(os.path.join(path, dir)))


fix_image_files(os.curdir)

How to get hex color value rather than RGB value?

Just to add to @Justin's answer above..

it should be

var rgb = document.querySelector('#selector').style['background-color'];
return '#' + rgb.substr(4, rgb.indexOf(')') - 4).split(',').map((color) => String("0" + parseInt(color).toString(16)).slice(-2)).join('');

As the above parse int functions truncates leading zeroes, thus produces incorrect color codes of 5 or 4 letters may be... i.e. for rgb(216, 160, 10) it produces #d8a0a while it should be #d8a00a.

Thanks

How to change RGB color to HSV?

There's a C implementation here:

http://www.cs.rit.edu/~ncs/color/t_convert.html

Should be very straightforward to convert to C#, as almost no functions are called - just calculations.

found via Google

Python Anaconda - How to Safely Uninstall

From the docs:

To uninstall Anaconda open a terminal window and remove the entire anaconda install directory: rm -rf ~/anaconda. You may also edit ~/.bash_profile and remove the anaconda directory from your PATH environment variable, and remove the hidden .condarc file and .conda and .continuum directories which may have been created in the home directory with rm -rf ~/.condarc ~/.conda ~/.continuum.

Further notes:

  • Python3 installs may use a ~/anaconda3 dir instead of ~/anaconda.
  • You might also have a ~/.anaconda hidden directory that may be removed.
  • Depending on how you installed, it is possible that the PATH is modified in one of your runcom files, and not in your shell profile. So, for example if you are using bash, be sure to check your ~/.bashrc if you don't find the PATH modified in ~/.bash_profile.

Generating random whole numbers in JavaScript in a specific range?

  • random(min,max) generates a random number between min (inclusive) and max (exclusive)
  • Math.floor rounds a number down to the nearest integer

    function generateRandomInteger (min, max) { 
        return Math.floor(random(min,max)) 
    }`
    

So to generate a random integer between 4 and 8 inclusive, call the above function with the following arguments:

generateRandomInteger (4,9)

How do I find out if a column exists in a VB.Net DataRow

DataRow's are nice in the way that they have their underlying table linked to them. With the underlying table you can verify that a specific row has a specific column in it.

    If DataRow.Table.Columns.Contains("column") Then
        MsgBox("YAY")
    End If

What is the Swift equivalent of respondsToSelector?

There is no real Swift replacement.

You can check in the following way:

someObject.someMethod?()

This calls the method someMethod only if it's defined on object someObject but you can use it only for @objc protocols which have declared the method as optional.

Swift is inherently a safe language so everytime you call a method Swift has to know the method is there. No runtime checking is possible. You can't just call random methods on random objects.

Even in Obj-C you should avoid such things when possible because it doesn't play well with ARC (ARC then triggers warnings for performSelector:).

However, when checking for available APIs, you can still use respondsToSelector:, even if Swift, if you are dealing with NSObject instances:

@interface TestA : NSObject

- (void)someMethod;

@end

@implementation TestA

//this triggers a warning

@end   


var a = TestA()

if a.respondsToSelector("someMethod") {
   a.someMethod()
}

How to use andWhere and orWhere in Doctrine?

One thing missing here: if you have a varying number of elements that you want to put together to something like

WHERE [...] AND (field LIKE '%abc%' OR field LIKE '%def%')

and dont want to assemble a DQL-String yourself, you can use the orX mentioned above like this:

$patterns = ['abc', 'def'];
$orStatements = $qb->expr()->orX();
foreach ($patterns as $pattern) {
    $orStatements->add(
        $qb->expr()->like('field', $qb->expr()->literal('%' . $pattern . '%'))
    );
}
$qb->andWhere($orStatements);

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

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

How to make use of ng-if , ng-else in angularJS

The syntax for ng if else in angular is :

<div class="case" *ngIf="data.id === '5'; else elsepart; ">
    <input type="checkbox" id="{{data.id}}" value="{{data.displayName}}" 
    data-ng-model="customizationCntrl.check[data.id1]" data-ng-checked="
    {{data.status}}=='1'" onclick="return false;">{{data.displayName}}<br>
</div>
<ng-template #elsepart>
    <div class="case">
        <input type="checkbox" id="{{data.id}}" value={{data.displayName}}"  
        data-ng-model="customizationCntrl.check[data.id]" data-ng-checked="
        {{data.status}}=='1'">{{data.displayName}}<br>
    </div> 
</ng-template>

How to create an empty array in PHP with predefined size?

 $array = new SplFixedArray(5);
   echo $array->getSize()."\n";

You can use PHP documentation more info check this link https://www.php.net/manual/en/splfixedarray.setsize.php

How to use ternary operator in razor (specifically on HTML attributes)?

You should be able to use the @() expression syntax:

<a class="@(User.Identity.IsAuthenticated ? "auth" : "anon")">My link here</a>

Parse JSON String into List<string>

Wanted to post this as a comment as a side note to the accepted answer, but that got a bit unclear. So purely as a side note:

If you have no need for the objects themselves and you want to have your project clear of further unused classes, you can parse with something like:

var list = JObject.Parse(json)["People"].Select(el => new { FirstName = (string)el["FirstName"], LastName = (string)el["LastName"] }).ToList();

var firstNames = list.Select(p => p.FirstName).ToList();
var lastNames = list.Select(p => p.LastName).ToList();

Even when using a strongly typed person class, you can still skip the root object by creating a list with JObject.Parse(json)["People"].ToObject<List<Person>>() Of course, if you do need to reuse the objects, it's better to create them from the start. Just wanted to point out the alternative ;)

Fancybox doesn't work with jQuery v1.9.0 [ f.browser is undefined / Cannot read property 'msie' ]

Global events are also deprecated.

Here's a patch, which fixes the browser and event issues:

--- jquery.fancybox-1.3.4.js.orig   2010-11-11 23:31:54.000000000 +0100
+++ jquery.fancybox-1.3.4.js    2013-03-22 23:25:29.996796800 +0100
@@ -26,7 +26,9 @@

        titleHeight = 0, titleStr = '', start_pos, final_pos, busy = false, fx = $.extend($('<div/>')[0], { prop: 0 }),

-       isIE6 = $.browser.msie && $.browser.version < 7 && !window.XMLHttpRequest,
+       isIE = !+"\v1",
+       
+       isIE6 = isIE && window.XMLHttpRequest === undefined,

        /*
         * Private methods 
@@ -322,7 +324,7 @@
            loading.hide();

            if (wrap.is(":visible") && false === currentOpts.onCleanup(currentArray, currentIndex, currentOpts)) {
-               $.event.trigger('fancybox-cancel');
+               $('.fancybox-inline-tmp').trigger('fancybox-cancel');

                busy = false;
                return;
@@ -389,7 +391,7 @@
                        content.html( tmp.contents() ).fadeTo(currentOpts.changeFade, 1, _finish);
                    };

-                   $.event.trigger('fancybox-change');
+                   $('.fancybox-inline-tmp').trigger('fancybox-change');

                    content
                        .empty()
@@ -612,7 +614,7 @@
            }

            if (currentOpts.type == 'iframe') {
-               $('<iframe id="fancybox-frame" name="fancybox-frame' + new Date().getTime() + '" frameborder="0" hspace="0" ' + ($.browser.msie ? 'allowtransparency="true""' : '') + ' scrolling="' + selectedOpts.scrolling + '" src="' + currentOpts.href + '"></iframe>').appendTo(content);
+               $('<iframe id="fancybox-frame" name="fancybox-frame' + new Date().getTime() + '" frameborder="0" hspace="0" ' + (isIE ? 'allowtransparency="true""' : '') + ' scrolling="' + selectedOpts.scrolling + '" src="' + currentOpts.href + '"></iframe>').appendTo(content);
            }

            wrap.show();
@@ -912,7 +914,7 @@

        busy = true;

-       $.event.trigger('fancybox-cancel');
+       $('.fancybox-inline-tmp').trigger('fancybox-cancel');

        _abort();

@@ -957,7 +959,7 @@
            title.empty().hide();
            wrap.hide();

-           $.event.trigger('fancybox-cleanup');
+           $('.fancybox-inline-tmp, select:not(#fancybox-tmp select)').trigger('fancybox-cleanup');

            content.empty();

Running bash script from within python

Make sure that sleep.sh has execution permissions, and run it with shell=True:

#!/usr/bin/python

import subprocess
print "start"
subprocess.call("./sleep.sh", shell=True)
print "end"

Should I size a textarea with CSS width / height or HTML cols / rows attributes?

if you dont use every time use line-height:'..'; property its control the height of textarea and width property for width of textarea.

or you can make use of font-size by following css:

#sbr {
  font-size: 16px;
  line-height:1.4;
  width:100%;
}

TempData keep() vs peek()

When an object in a TempDataDictionary is read, it will be marked for deletion at the end of that request.

That means if you put something on TempData like

TempData["value"] = "someValueForNextRequest";

And on another request you access it, the value will be there but as soon as you read it, the value will be marked for deletion:

//second request, read value and is marked for deletion
object value = TempData["value"];

//third request, value is not there as it was deleted at the end of the second request
TempData["value"] == null

The Peek and Keep methods allow you to read the value without marking it for deletion. Say we get back to the first request where the value was saved to TempData.

With Peek you get the value without marking it for deletion with a single call, see msdn:

//second request, PEEK value so it is not deleted at the end of the request
object value = TempData.Peek("value");

//third request, read value and mark it for deletion
object value = TempData["value"];

With Keep you specify a key that was marked for deletion that you want to keep. Retrieving the object and later on saving it from deletion are 2 different calls. See msdn

//second request, get value marking it from deletion
object value = TempData["value"];
//later on decide to keep it
TempData.Keep("value");

//third request, read value and mark it for deletion
object value = TempData["value"];

You can use Peek when you always want to retain the value for another request. Use Keep when retaining the value depends on additional logic.

You have 2 good questions about how TempData works here and here

Hope it helps!

How to find the extension of a file in C#?

I'm not sure if this is what you want but:

Directory.GetFiles(@"c:\mydir", "*.flv");

Or:

Path.GetExtension(@"c:\test.flv")

What are the differences between delegates and events?

NOTE: If you have access to C# 5.0 Unleashed, read the "Limitations on Plain Use of Delegates" in Chapter 18 titled "Events" to understand better the differences between the two.


It always helps me to have a simple, concrete example. So here's one for the community. First I show how you can use delegates alone to do what Events do for us. Then I show how the same solution would work with an instance of EventHandler. And then I explain why we DON'T want to do what I explain in the first example. This post was inspired by an article by John Skeet.

Example 1: Using public delegate

Suppose I have a WinForms app with a single drop-down box. The drop-down is bound to an List<Person>. Where Person has properties of Id, Name, NickName, HairColor. On the main form is a custom user control that shows the properties of that person. When someone selects a person in the drop-down the labels in the user control update to show the properties of the person selected.

enter image description here

Here is how that works. We have three files that help us put this together:

  • Mediator.cs -- static class holds the delegates
  • Form1.cs -- main form
  • DetailView.cs -- user control shows all details

Here is the relevant code for each of the classes:

class Mediator
{
    public delegate void PersonChangedDelegate(Person p); //delegate type definition
    public static PersonChangedDelegate PersonChangedDel; //delegate instance. Detail view will "subscribe" to this.
    public static void OnPersonChanged(Person p) //Form1 will call this when the drop-down changes.
    {
        if (PersonChangedDel != null)
        {
            PersonChangedDel(p);
        }
    }
}

Here is our user control:

public partial class DetailView : UserControl
{
    public DetailView()
    {
        InitializeComponent();
        Mediator.PersonChangedDel += DetailView_PersonChanged;
    }

    void DetailView_PersonChanged(Person p)
    {
        BindData(p);
    }

    public void BindData(Person p)
    {
        lblPersonHairColor.Text = p.HairColor;
        lblPersonId.Text = p.IdPerson.ToString();
        lblPersonName.Text = p.Name;
        lblPersonNickName.Text = p.NickName;

    }
}

Finally we have the following code in our Form1.cs. Here we are Calling OnPersonChanged, which calls any code subscribed to the delegate.

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
    Mediator.OnPersonChanged((Person)comboBox1.SelectedItem); //Call the mediator's OnPersonChanged method. This will in turn call all the methods assigned (i.e. subscribed to) to the delegate -- in this case `DetailView_PersonChanged`.
}

Ok. So that's how you would get this working without using events and just using delegates. We just put a public delegate into a class -- you can make it static or a singleton, or whatever. Great.

BUT, BUT, BUT, we do not want to do what I just described above. Because public fields are bad for many, many reason. So what are our options? As John Skeet describes, here are our options:

  1. A public delegate variable (this is what we just did above. don't do this. i just told you above why it's bad)
  2. Put the delegate into a property with a get/set (problem here is that subscribers could override each other -- so we could subscribe a bunch of methods to the delegate and then we could accidentally say PersonChangedDel = null, wiping out all of the other subscriptions. The other problem that remains here is that since the users have access to the delegate, they can invoke the targets in the invocation list -- we don't want external users having access to when to raise our events.
  3. A delegate variable with AddXXXHandler and RemoveXXXHandler methods

This third option is essentially what an event gives us. When we declare an EventHandler, it gives us access to a delegate -- not publicly, not as a property, but as this thing we call an event that has just add/remove accessors.

Let's see what the same program looks like, but now using an Event instead of the public delegate (I've also changed our Mediator to a singleton):

Example 2: With EventHandler instead of a public delegate

Mediator:

class Mediator
{

    private static readonly Mediator _Instance = new Mediator();

    private Mediator() { }

    public static Mediator GetInstance()
    {
        return _Instance;
    }

    public event EventHandler<PersonChangedEventArgs> PersonChanged; //this is just a property we expose to add items to the delegate.

    public void OnPersonChanged(object sender, Person p)
    {
        var personChangedDelegate = PersonChanged as EventHandler<PersonChangedEventArgs>;
        if (personChangedDelegate != null)
        {
            personChangedDelegate(sender, new PersonChangedEventArgs() { Person = p });
        }
    }
}

Notice that if you F12 on the EventHandler, it will show you the definition is just a generic-ified delegate with the extra "sender" object:

public delegate void EventHandler<TEventArgs>(object sender, TEventArgs e);

The User Control:

public partial class DetailView : UserControl
{
    public DetailView()
    {
        InitializeComponent();
        Mediator.GetInstance().PersonChanged += DetailView_PersonChanged;
    }

    void DetailView_PersonChanged(object sender, PersonChangedEventArgs e)
    {
        BindData(e.Person);
    }

    public void BindData(Person p)
    {
        lblPersonHairColor.Text = p.HairColor;
        lblPersonId.Text = p.IdPerson.ToString();
        lblPersonName.Text = p.Name;
        lblPersonNickName.Text = p.NickName;

    }
}

Finally, here's the Form1.cs code:

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
        Mediator.GetInstance().OnPersonChanged(this, (Person)comboBox1.SelectedItem);
}

Because the EventHandler wants and EventArgs as a parameter, I created this class with just a single property in it:

class PersonChangedEventArgs
{
    public Person Person { get; set; }
}

Hopefully that shows you a bit about why we have events and how they are different -- but functionally the same -- as delegates.

How to read an http input stream

a complete code for reading from a webservice in two ways

public void buttonclick(View view) {
    // the name of your webservice where reactance is your method
    new GetMethodDemo().execute("http://wervicename.nl/service.asmx/reactance");
}

public class GetMethodDemo extends AsyncTask<String, Void, String> {
    //see also: 
    // https://developer.android.com/reference/java/net/HttpURLConnection.html
    //writing to see:    https://docs.oracle.com/javase/tutorial/networking/urls/readingWriting.html
    String server_response;
    @Override
    protected String doInBackground(String... strings) {
        URL url;
        HttpURLConnection urlConnection = null;
        try {
            url = new URL(strings[0]);
            urlConnection = (HttpURLConnection) url.openConnection();
            int responseCode = urlConnection.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                server_response = readStream(urlConnection.getInputStream());
                Log.v("CatalogClient", server_response);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            url = new URL(strings[0]);
            urlConnection = (HttpURLConnection) url.openConnection();
            BufferedReader in = new BufferedReader(new InputStreamReader(
                    urlConnection.getInputStream()));
            String inputLine;
            while ((inputLine = in.readLine()) != null)
                System.out.println(inputLine);
            in.close();
            Log.v("bufferv ", server_response);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        Log.e("Response", "" + server_response);
   //assume there is a field with id editText
        EditText editText = (EditText) findViewById(R.id.editText);
        editText.setText(server_response);
    }
}

JFrame in full screen Java

One way is to use the Extended State. This asks the underlying OS to maximize the JFrame.

setExtendedState(getExtendedState() | JFrame.MAXIMIZED_BOTH);

Other approach would be to manually maximize the screen for you requirement.

Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
setBounds(100, 100, (int) dim.getWidth(), (int) dim.getHeight());
setLocationRelativeTo(null);

But this has pitfalls in Ubuntu OS. The work around I found was this.

if (SystemHelper.isUnix()) {
    getContentPane().setPreferredSize(
    Toolkit.getDefaultToolkit().getScreenSize());
    pack();
    setResizable(false);
    show();

    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            Point p = new Point(0, 0);
            SwingUtilities.convertPointToScreen(p, getContentPane());
            Point l = getLocation();
            l.x -= p.x;
            l.y -= p.y;
            setLocation(p);
        }
    });
}

Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
setBounds(100, 100, (int) dim.getWidth(), (int) dim.getHeight());
setLocationRelativeTo(null);

In Fedora the above problem is not present. But there are complications involved with Gnome or KDE. So better be careful. Hope this helps.

Returning http status code from Web Api controller

You can also do the following if you want to preserve the action signature as returning User:

public User GetUser(int userId, DateTime lastModifiedAtClient) 

If you want to return something other than 200 then you throw an HttpResponseException in your action and pass in the HttpResponseMessage you want to send to the client.

Adding Python Path on Windows 7

When setting Environmental Variables in Windows, I have gone wrong on many, many occasions. I thought I should share a few of my past mistakes here hoping that it might help someone. (These apply to all Environmental Variables, not just when setting Python Path)

Watch out for these possible mistakes:

  1. Kill and reopen your shell window: Once you make a change to the ENVIRONMENTAL Variables, you have to restart the window you are testing it on.
  2. NO SPACES when setting the Variables. Make sure that you are adding the ;C:\Python27 WITHOUT any spaces. (It is common to try C:\SomeOther; C:\Python27 That space (?) after the semicolon is not okay.)
  3. USE A BACKWARD SLASH when spelling out your full path. You will see forward slashes when you try echo $PATH but only backward slashes have worked for me.
  4. DO NOT ADD a final backslash. Only C:\Python27 NOT C:\Python27\

Hope this helps someone.

Android Viewpager as Image Slide Gallery

you can use custom gallery control.. check this https://github.com/kilaka/ImageViewZoom use galleryTouch class from this..

How to fix HTTP 404 on Github Pages?

Also, GitHub pages doesn't currently support Git LFS. As such, if you have images (or other binary assets) in GitHub pages committed with Git LFS, you'll get 404 not found for those files.

This will be quite common for documentation generated with Doxygen or similar tool.

The solution in this case is to simply not commit those files with Git LFS.

mysql extract year from date format

TRY:

SELECT EXTRACT(YEAR FROM (STR_TO_DATE(subdateshow, '%d/%m/%Y')));

Apache server keeps crashing, "caught SIGTERM, shutting down"

Try to upgrade and install new packages

sudo apt-get update && sudo apt-get upgrade -y

Suppress/ print without b' prefix for bytes in Python 3

you can use this code for showing or print :

<byte_object>.decode("utf-8")

and you can use this for encode or saving :

<str_object>.encode('utf-8')

Force Internet Explorer to use a specific Java Runtime Environment install?

For the server-side solution (which your question was originally ambiguous about), this page at sun lists one way to specify a JRE. Specifically,

<OBJECT 
  classid="clsid:8AD9C840-044E-11D1-B3E9-00805F499D93"
  width="200" height="200">
  <PARAM name="code" value="Applet1.class">
</OBJECT>

The classid attribute identifies which version of Java Plug-in to use.

Following is an alternative form of the classid attribute:

classid="clsid:CAFEEFAC-xxxx-yyyy-zzzz-ABCDEFFEDCBA"

In this form, "xxxx", "yyyy", and "zzzz" are four-digit numbers that identify the specific version of Java Plug-in to be used.

For example, to use Java Plug-in version 1.5.0, you specify:

classid="clsid:CAFEEFAC-0015-0000-0000-ABCDEFFEDCBA"

Regex match everything after question mark?

Check out this site: http://rubular.com/ Basically the site allows you to enter some example text (what you would be looking for on your site) and then as you build the regular expression it will highlight what is being matched in real time.

Contains case insensitive

Another options is to use the search method as follow:

if (referrer.search(new RegExp("Ral", "i")) == -1) { ...

It looks more elegant then converting the whole string to lower case and it may be more efficient.
With toLowerCase() the code have two pass over the string, one pass is on the entire string to convert it to lower case and another is to look for the desired index.
With RegExp the code have one pass over the string which it looks to match the desired index.

Therefore, on long strings I recommend to use the RegExp version (I guess that on short strings this efficiency comes on the account of creating the RegExp object though)

How to send objects through bundle

You can also use Gson to convert an object to a JSONObject and pass it on bundle. For me was the most elegant way I found to do this. I haven't tested how it affects performance.

In Initial Activity

Intent activity = new Intent(MyActivity.this,NextActivity.class);
activity.putExtra("myObject", new Gson().toJson(myobject));
startActivity(activity);

In Next Activity

String jsonMyObject;
Bundle extras = getIntent().getExtras();
if (extras != null) {
   jsonMyObject = extras.getString("myObject");
}
MyObject myObject = new Gson().fromJson(jsonMyObject, MyObject.class);

Jar mismatch! Fix your dependencies

  1. Jar mismatch comes when you use library projects in your application and both projects are using same jar with different version so just check all library projects attached in your application. if some mismatch exist then remove it.

  2. if above process is not working then just do remove project dependency from build path and again add library projects and build the application.

eval command in Bash and its typical uses

Simply think of eval as "evaluating your expression one additional time before execution"

eval echo \${$n} becomes echo $1 after the first round of evaluation. Three changes to notice:

  • The \$ became $ (The backslash is needed, otherwise it tries to evaluate ${$n}, which means a variable named {$n}, which is not allowed)
  • $n was evaluated to 1
  • The eval disappeared

In the second round, it is basically echo $1 which can be directly executed.

So eval <some command> will first evaluate <some command> (by evaluate here I mean substitute variables, replace escaped characters with the correct ones etc.), and then run the resultant expression once again.

eval is used when you want to dynamically create variables, or to read outputs from programs specifically designed to be read like this. See http://mywiki.wooledge.org/BashFAQ/048 for examples. The link also contains some typical ways in which eval is used, and the risks associated with it.

How to delete columns in pyspark dataframe

Consider 2 dataFrames:

>>> aDF.show()
+---+----+
| id|datA|
+---+----+
|  1|  a1|
|  2|  a2|
|  3|  a3|
+---+----+

and

>>> bDF.show()
+---+----+
| id|datB|
+---+----+
|  2|  b2|
|  3|  b3|
|  4|  b4|
+---+----+

To accomplish what you are looking for, there are 2 ways:

1. Different joining condition. Instead of saying aDF.id == bDF.id

aDF.join(bDF, aDF.id == bDF.id, "outer")

Write this:

aDF.join(bDF, "id", "outer").show()
+---+----+----+
| id|datA|datB|
+---+----+----+
|  1|  a1|null|
|  3|  a3|  b3|
|  2|  a2|  b2|
|  4|null|  b4|
+---+----+----+

This will automatically get rid of the extra the dropping process.

2. Use Aliasing: You will lose data related to B Specific Id's in this.

>>> from pyspark.sql.functions import col
>>> aDF.alias("a").join(bDF.alias("b"), aDF.id == bDF.id, "outer").drop(col("b.id")).show()

+----+----+----+
|  id|datA|datB|
+----+----+----+
|   1|  a1|null|
|   3|  a3|  b3|
|   2|  a2|  b2|
|null|null|  b4|
+----+----+----+

Speed tradeoff of Java's -Xms and -Xmx options

> C:\java -X

-Xmixed           mixed mode execution (default)
-Xint             interpreted mode execution only
-Xbootclasspath:<directories and zip/jar files separated by ;>
                  set search path for bootstrap classes and resources
-Xbootclasspath/a:<directories and zip/jar files separated by ;>
                  append to end of bootstrap class path
-Xbootclasspath/p:<directories and zip/jar files separated by ;>
                  prepend in front of bootstrap class path
-Xnoclassgc       disable class garbage collection
-Xincgc           enable incremental garbage collection
-Xloggc:<file>    log GC status to a file with time stamps
-Xbatch           disable background compilation
-Xms<size>        set initial Java heap size
-Xmx<size>        set maximum Java heap size
-Xss<size>        set java thread stack size
-Xprof            output cpu profiling data
-Xfuture          enable strictest checks, anticipating future default
-Xrs              reduce use of OS signals by Java/VM (see documentation)
-Xcheck:jni       perform additional checks for JNI functions
-Xshare:off       do not attempt to use shared class data
-Xshare:auto      use shared class data if possible (default)
-Xshare:on        require using shared class data, otherwise fail.

The -X options are non-standard and subject to change without notice.

(copy-paste)

How to send JSON instead of a query string with $.ajax?

While I know many architectures like ASP.NET MVC have built-in functionality to handle JSON.stringify as the contentType my situation is a little different so maybe this may help someone in the future. I know it would have saved me hours!

Since my http requests are being handled by a CGI API from IBM (AS400 environment) on a different subdomain these requests are cross origin, hence the jsonp. I actually send my ajax via javascript object(s). Here is an example of my ajax POST:

 var data = {USER : localProfile,  
        INSTANCE : "HTHACKNEY",  
        PAGE : $('select[name="PAGE"]').val(), 
        TITLE : $("input[name='TITLE']").val(), 
        HTML : html,
        STARTDATE : $("input[name='STARTDATE']").val(), 
        ENDDATE : $("input[name='ENDDATE']").val(),
        ARCHIVE : $("input[name='ARCHIVE']").val(), 
        ACTIVE : $("input[name='ACTIVE']").val(), 
        URGENT : $("input[name='URGENT']").val(), 
        AUTHLST :  authStr};
        //console.log(data);
       $.ajax({
            type: "POST",
           url:   "http://www.domian.com/webservicepgm?callback=?",
           data:  data,
           dataType:'jsonp'
       }).
       done(function(data){
         //handle data.WHATEVER
       });

How to check a boolean condition in EL?

Both works. Instead of == you can write eq

VueJS conditionally add an attribute for an element

You can pass boolean by coercing it, put !! before the variable.

let isRequired = '' || null || undefined
<input :required="!!isRequired"> // it will coerce value to respective boolean 

But I would like to pull your attention for the following case where the receiving component has defined type for props. In that case, if isRequired has defined type to be string then passing boolean make it type check fails and you will get Vue warning. To fix that you may want to avoid passing that prop, so just put undefined fallback and the prop will not sent to component

let isValue = false
<any-component
  :my-prop="isValue ? 'Hey I am when the value exist' : undefined"
/>

Explanation

I have been through the same problem, and tried above solutions !! Yes, I don't see the prop but that actually does not fulfils what required here.

My problem -

let isValid = false
<any-component
  :my-prop="isValue ? 'Hey I am when the value exist': false"
/>

In the above case, what I expected is not having my-prop get passed to the child component - <any-conponent/> I don't see the prop in DOM but In my <any-component/> component, an error pops out of prop type check failure. As in the child component, I am expecting my-prop to be a String but it is boolean.

myProp : {
 type: String,
 required: false,
 default: ''
}

Which means that child component did receive the prop even if it is false. Tweak here is to let the child component to take the default-value and also skip the check. Passed undefined works though!

<any-component
  :my-prop="isValue ? 'Hey I am when the value exist' : undefined"
/>
 

This works and my child prop is having the default value.

Can I safely delete contents of Xcode Derived data folder?

yes, safe to delete, my script searches and nukes every instance it finds, easily modified to a local directory

#!/usr/bin/env bash
set -o errexit
set -o nounset
set -o pipefail
IFS=$'\n\t'

for drive in Swap Media OSX_10.11.6/$HOME
do
   pushd /Volumes/${drive}  &> /dev/null
   gfind . -depth -name 'DerivedData'|xargs -I '{}' /bin/rm -fR '{}'
   popd &> /dev/null
done

Xcode 10 Error: Multiple commands produce

Remove the damn Assets file

Solution -> Open target -> Build phases > Copy Bundle Resources and remove Assets from there.

How to get body of a POST in php?

return value in array

 $data = json_decode(file_get_contents('php://input'), true);

PHP, Get tomorrows date from date

By strange it can seem it works perfectly fine: date_create( '2016-02-01 + 1 day' );

echo date_create( $your_date . ' + 1 day' )->format( 'Y-m-d' );

Should do it

How to use JUnit to test asynchronous processes

There's nothing inherently wrong with testing threaded/async code, particularly if threading is the point of the code you're testing. The general approach to testing this stuff is to:

  • Block the main test thread
  • Capture failed assertions from other threads
  • Unblock the main test thread
  • Rethrow any failures

But that's a lot of boilerplate for one test. A better/simpler approach is to just use ConcurrentUnit:

  final Waiter waiter = new Waiter();

  new Thread(() -> {
    doSomeWork();
    waiter.assertTrue(true);
    waiter.resume();
  }).start();

  // Wait for resume() to be called
  waiter.await(1000);

The benefit of this over the CountdownLatch approach is that it's less verbose since assertion failures that occur in any thread are properly reported to the main thread, meaning the test fails when it should. A writeup that compares the CountdownLatch approach to ConcurrentUnit is here.

I also wrote a blog post on the topic for those who want to learn a bit more detail.

How to use GNU Make on Windows?

While make itself is available as a standalone executable (gnuwin32.sourceforge.net package make), using it in a proper development environment means using msys2.

Git 2.24 (Q4 2019) illustrates that:

See commit 4668931, commit b35304b, commit ab7d854, commit be5d88e, commit 5d65ad1, commit 030a628, commit 61d1d92, commit e4347c9, commit ed712ef, commit 5b8f9e2, commit 41616ef, commit c097b95 (04 Oct 2019), and commit dbcd970 (30 Sep 2019) by Johannes Schindelin (dscho).
(Merged by Junio C Hamano -- gitster -- in commit 6d5291b, 15 Oct 2019)

test-tool run-command: learn to run (parts of) the testsuite

Signed-off-by: Johannes Schindelin

Git for Windows jumps through hoops to provide a development environment that allows to build Git and to run its test suite.

To that end, an entire MSYS2 system, including GNU make and GCC is offered as "the Git for Windows SDK".
It does come at a price: an initial download of said SDK weighs in with several hundreds of megabytes, and the unpacked SDK occupies ~2GB of disk space.

A much more native development environment on Windows is Visual Studio. To help contributors use that environment, we already have a Makefile target vcxproj that generates a commit with project files (and other generated files), and Git for Windows' vs/master branch is continuously re-generated using that target.

The idea is to allow building Git in Visual Studio, and to run individual tests using a Portable Git.

What's the difference between getPath(), getAbsolutePath(), and getCanonicalPath() in Java?

In short:

  • getPath() gets the path string that the File object was constructed with, and it may be relative current directory.
  • getAbsolutePath() gets the path string after resolving it against the current directory if it's relative, resulting in a fully qualified path.
  • getCanonicalPath() gets the path string after resolving any relative path against current directory, and removes any relative pathing (. and ..), and any file system links to return a path which the file system considers the canonical means to reference the file system object to which it points.

Also, each of these has a File equivalent which returns the corresponding File object.

Note that IMO, Java got the implementation of an "absolute" path wrong; it really should remove any relative path elements in an absolute path. The canonical form would then remove any FS links or junctions in the path.

Pandas - Compute z-score for all columns

Build a list from the columns and remove the column you don't want to calculate the Z score for:

In [66]:
cols = list(df.columns)
cols.remove('ID')
df[cols]

Out[66]:
   Age  BMI  Risk  Factor
0    6   48  19.3       4
1    8   43  20.9     NaN
2    2   39  18.1       3
3    9   41  19.5     NaN
In [68]:
# now iterate over the remaining columns and create a new zscore column
for col in cols:
    col_zscore = col + '_zscore'
    df[col_zscore] = (df[col] - df[col].mean())/df[col].std(ddof=0)
df
Out[68]:
   ID  Age  BMI  Risk  Factor  Age_zscore  BMI_zscore  Risk_zscore  \
0  PT    6   48  19.3       4   -0.093250    1.569614    -0.150946   
1  PT    8   43  20.9     NaN    0.652753    0.074744     1.459148   
2  PT    2   39  18.1       3   -1.585258   -1.121153    -1.358517   
3  PT    9   41  19.5     NaN    1.025755   -0.523205     0.050315   

   Factor_zscore  
0              1  
1            NaN  
2             -1  
3            NaN  

when I run mockito test occurs WrongTypeOfReturnValue Exception

According to https://groups.google.com/forum/?fromgroups#!topic/mockito/9WUvkhZUy90, you should rephrase your

when(bar.getFoo()).thenReturn(fooBar)

to

doReturn(fooBar).when(bar).getFoo()

How to compare arrays in C#?

You can use the Enumerable.SequenceEqual() in the System.Linq to compare the contents in the array

bool isEqual = Enumerable.SequenceEqual(target1, target2);

tmux set -g mouse-mode on doesn't work

Try this. It works on my computer.

set -g mouse on

using favicon with css

You don't need to - if the favicon is place in the root at favicon.ico, browsers will automatically pick it up.

If you don't see it working, clear your cache etc, it does work without the markup. You only need to use the code if you want to call it something else, or put it on a CDN for instance.

extract the date part from DateTime in C#

DateTime is a DataType which is used to store both Date and Time. But it provides Properties to get the Date Part.

You can get the Date part from Date Property.

http://msdn.microsoft.com/en-us/library/system.datetime.date.aspx

DateTime date1 = new DateTime(2008, 6, 1, 7, 47, 0);
Console.WriteLine(date1.ToString());

// Get date-only portion of date, without its time.
DateTime dateOnly = date1.Date;
// Display date using short date string.
Console.WriteLine(dateOnly.ToString("d"));
// Display date using 24-hour clock.
Console.WriteLine(dateOnly.ToString("g"));
Console.WriteLine(dateOnly.ToString("MM/dd/yyyy HH:mm"));   
// The example displays the following output to the console:
//       6/1/2008 7:47:00 AM
//       6/1/2008
//       6/1/2008 12:00 AM
//       06/01/2008 00:00

Can I animate absolute positioned element with CSS transition?

Please Try this code margin-left:60px instead of left:60px

please take a look: http://jsfiddle.net/hbirjand/2LtBh/2/

as @Shomz said,transition must be changed to transition:margin 1s linear; instead of transition:all 1s linear;

Get folder name from full file path

Here is an alternative method that worked for me without having to create a DirectoryInfo object. The key point is that GetFileName() works when there is no trailing slash in the path.

var name = Path.GetFileName(path.TrimEnd(Path.DirectorySeparatorChar));

Example:

var list = Directory.EnumerateDirectories(path, "*")
        .Select(p => new
        {
            id = "id_" + p.GetHashCode().ToString("x"),
            text = Path.GetFileName(p.TrimEnd(Path.DirectorySeparatorChar)),
            icon = "fa fa-folder",
            children = true
        })
        .Distinct()
        .OrderBy(p => p.text);

max value of integer

That's because in C - integer on 32 bit machine doesn't mean that 32 bits are used for storing it, it may be 16 bits as well. It depends on the machine (implementation-dependent).

If Else in LINQ

I assume from db that this is LINQ-to-SQL / Entity Framework / similar (not LINQ-to-Objects);

Generally, you do better with the conditional syntax ( a ? b : c) - however, I don't know if it will work with your different queries like that (after all, how would your write the TSQL?).

For a trivial example of the type of thing you can do:

select new {p.PriceID, Type = p.Price > 0 ? "debit" : "credit" };

You can do much richer things, but I really doubt you can pick the table in the conditional. You're welcome to try, of course...

Export tables to an excel spreadsheet in same directory

You can use VBA to export an Access database table as a Worksheet in an Excel Workbook.

To obtain the path of the Access database, use the CurrentProject.Path property.

To name the Excel Workbook file with the current date, use the Format(Date, "yyyyMMdd") method.

Finally, to export the table as a Worksheet, use the DoCmd.TransferSpreadsheet method.

Example:

Dim outputFileName As String
outputFileName = CurrentProject.Path & "\Export_" & Format(Date, "yyyyMMdd") & ".xls"
DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel9, "Table1", outputFileName , True
DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel9, "Table2", outputFileName , True

This will output both Table1 and Table2 into the same Workbook.

HTH

Using jQuery to center a DIV on the screen

To center the element relative to the browser viewport (window), don't use position: absolute, the correct position value should be fixed (absolute means: "The element is positioned relative to its first positioned (not static) ancestor element").

This alternative version of the proposed center plugin uses "%" instead of "px" so when you resize the window the content is keep centered:

$.fn.center = function () {
    var heightRatio = ($(window).height() != 0) 
            ? this.outerHeight() / $(window).height() : 1;
    var widthRatio = ($(window).width() != 0) 
            ? this.outerWidth() / $(window).width() : 1;

    this.css({
        position: 'fixed',
        margin: 0,
        top: (50*(1-heightRatio)) + "%",
        left: (50*(1-widthRatio))  + "%"
    });

    return this;
}

You need to put margin: 0 to exclude the content margins from the width/height (since we are using position fixed, having margins makes no sense). According to the jQuery doc using .outerWidth(true) should include margins, but it didn't work as expected when I tried in Chrome.

The 50*(1-ratio) comes from:

Window Width: W = 100%

Element Width (in %): w = 100 * elementWidthInPixels/windowWidthInPixels

Them to calcule the centered left:

 left = W/2 - w/2 = 50 - 50 * elementWidthInPixels/windowWidthInPixels =
 = 50 * (1-elementWidthInPixels/windowWidthInPixels)

TypeError: 'type' object is not subscriptable when indexing in to a dictionary

Normally Python throws NameError if the variable is not defined:

>>> d[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'd' is not defined

However, you've managed to stumble upon a name that already exists in Python.

Because dict is the name of a built-in type in Python you are seeing what appears to be a strange error message, but in reality it is not.

The type of dict is a type. All types are objects in Python. Thus you are actually trying to index into the type object. This is why the error message says that the "'type' object is not subscriptable."

>>> type(dict)
<type 'type'>
>>> dict[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'type' object is not subscriptable

Note that you can blindly assign to the dict name, but you really don't want to do that. It's just going to cause you problems later.

>>> dict = {1:'a'}
>>> type(dict)
<class 'dict'>
>>> dict[1]
'a'

The true source of the problem is that you must assign variables prior to trying to use them. If you simply reorder the statements of your question, it will almost certainly work:

d = {1: "walk1.png", 2: "walk2.png", 3: "walk3.png"}
m1 = pygame.image.load(d[1])
m2 = pygame.image.load(d[2])
m3 = pygame.image.load(d[3])
playerxy = (375,130)
window.blit(m1, (playerxy))

Removing All Items From A ComboBox?

If you want to simply remove the value in the combo box:

me.combobox = ""

If you want to remove the recordset of the combobox, the easiest way is:

me.combobox.recordset = ""
me.combobox.requery

In jQuery how can I set "top,left" properties of an element with position values relative to the parent and not the document?

To set the position relative to the parent you need to set the position:relative of parent and position:absolute of the element

$("#mydiv").parent().css({position: 'relative'});
$("#mydiv").css({top: 200, left: 200, position:'absolute'});

This works because position: absolute; positions relatively to the closest positioned parent (i.e., the closest parent with any position property other than the default static).

How To Set A JS object property name from a variable

With ECMAScript 6, you can use variable property names with the object literal syntax, like this:

var keyName = 'myKey';
var obj = {
              [keyName]: 1
          };
obj.myKey;//1

This syntax is available in the following newer browsers:

Edge 12+ (No IE support), FF34+, Chrome 44+, Opera 31+, Safari 7.1+

(https://kangax.github.io/compat-table/es6/)

You can add support to older browsers by using a transpiler such as babel. It is easy to transpile an entire project if you are using a module bundler such as rollup or webpack.

save a pandas.Series histogram plot to file

You can use ax.figure.savefig():

import pandas as pd

s = pd.Series([0, 1])
ax = s.plot.hist()
ax.figure.savefig('demo-file.pdf')

This has no practical benefit over ax.get_figure().savefig() as suggested in Philip Cloud's answer, so you can pick the option you find the most aesthetically pleasing. In fact, get_figure() simply returns self.figure:

# Source from snippet linked above
def get_figure(self):
    """Return the `.Figure` instance the artist belongs to."""
    return self.figure

The POM for project is missing, no dependency information available

The scope <scope>provided</scope> gives you an opportunity to tell that the jar would be available at runtime, so do not bundle it. It does not mean that you do not need it at compile time, hence maven would try to download that.

Now I think, the below maven artifact do not exist at all. I tries searching google, but not able to find. Hence you are getting this issue.

Change groupId to <groupId>net.sourceforge.ant4x</groupId> to get the latest jar.

<dependency>
  <groupId>net.sourceforge.ant4x</groupId>
  <artifactId>ant4x</artifactId>
  <version>${net.sourceforge.ant4x-version}</version>
  <scope>provided</scope>
</dependency>

Another solution for this problem is:

  1. Run your own maven repo.
  2. download the jar
  3. Install the jar into the repository.
  4. Add a code in your pom.xml something like:

Where http://localhost/repo is your local repo URL:

<repositories>
    <repository>
        <id>wmc-central</id>
        <url>http://localhost/repo</url>
    </repository>
    <-- Other repository config ... -->
</repositories>

How to get data by SqlDataReader.GetValue by column name

Log.WriteLine("Value of CompanyName column:" + thisReader["CompanyName"]); 

Android ImageButton with a selected state?

ToggleImageButton which implements Checkable interface and supports OnCheckedChangeListener and android:checked xml attribute:

public class ToggleImageButton extends ImageButton implements Checkable {
    private OnCheckedChangeListener onCheckedChangeListener;

    public ToggleImageButton(Context context) {
        super(context);
    }

    public ToggleImageButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        setChecked(attrs);
    }

    public ToggleImageButton(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setChecked(attrs);
    }

    private void setChecked(AttributeSet attrs) {
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ToggleImageButton);
        setChecked(a.getBoolean(R.styleable.ToggleImageButton_android_checked, false));
        a.recycle();
    }

    @Override
    public boolean isChecked() {
        return isSelected();
    }

    @Override
    public void setChecked(boolean checked) {
        setSelected(checked);

        if (onCheckedChangeListener != null) {
            onCheckedChangeListener.onCheckedChanged(this, checked);
        }
    }

    @Override
    public void toggle() {
        setChecked(!isChecked());
    }

    @Override
    public boolean performClick() {
        toggle();
        return super.performClick();
    }

    public OnCheckedChangeListener getOnCheckedChangeListener() {
        return onCheckedChangeListener;
    }

    public void setOnCheckedChangeListener(OnCheckedChangeListener onCheckedChangeListener) {
        this.onCheckedChangeListener = onCheckedChangeListener;
    }

    public static interface OnCheckedChangeListener {
        public void onCheckedChanged(ToggleImageButton buttonView, boolean isChecked);
    }
}

res/values/attrs.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="ToggleImageButton">
        <attr name="android:checked" />
    </declare-styleable>
</resources>

How do you fadeIn and animate at the same time?

$('.tooltip').animate({ opacity: 1, top: "-10px" }, 'slow');

However, this doesn't appear to work on display: none elements (as fadeIn does). So, you might need to put this beforehand:

$('.tooltip').css('display', 'block');
$('.tooltip').animate({ opacity: 0 }, 0);

How to stop app that node.js express 'npm start'

When I tried the suggested solution I realized that my app name was truncated. I read up on process.title in the nodejs documentation (https://nodejs.org/docs/latest/api/process.html#process_process_title) and it says

On Linux and OS X, it's limited to the size of the binary name plus the length of the command line arguments because it overwrites the argv memory.

My app does not use any arguments, so I can add this line of code to my app.js

process.title = process.argv[2];

and then add these few lines to my package.json file

  "scripts": {
    "start": "node app.js this-name-can-be-as-long-as-it-needs-to-be",
    "stop": "killall -SIGINT this-name-can-be-as-long-as-it-needs-to-be"
  },

to use really long process names. npm start and npm stop work, of course npm stop will always terminate all running processes, but that is ok for me.

What is the difference between BIT and TINYINT in MySQL?

A TINYINT is an 8-bit integer value, a BIT field can store between 1 bit, BIT(1), and 64 bits, BIT(64). For a boolean values, BIT(1) is pretty common.

How to initialize a list of strings (List<string>) with many string values

Just remove () at the end.

List<string> optionList = new List<string>
            { "AdditionalCardPersonAdressType", /* rest of elements */ };

How to install a .ipa file into my iPhone?

You need to install the provisioning profile (drag and drop it into iTunes). Then drag and drop the .ipa. Ensure you device is set to sync apps, and try again.

How to Find Item in Dictionary Collection?

Of course, if you want to make sure it's in there otherwise fail then this works:

thisTag = _tags[key];

NOTE: This will fail if the key,value pair does not exists but sometimes that is exactly what you want. This way you can catch it and do something about the error. I would only do this if I am certain that the key,value pair is or should be in the dictionary and if not I want it to know about it via the throw.

Apply CSS rules if browser is IE

A fast approach is to use the following according to ie that you want to focus (check the comments), inside your css files (where margin-top, set whatever css attribute you like):

margin-top: 10px\9; /*It will apply to all ie from 8 and below */
*margin-top: 10px; /*It will apply to ie 7 and below */
_margin-top: 10px; /*It will apply to ie 6 and below*/

A better approach would be to check user agent or a conditional if, in order to avoid the loading of unnecessary CSS in other browsers.

What are the safe characters for making URLs?

To quote section 2.3 of RFC 3986:

Characters that are allowed in a URI, but do not have a reserved purpose, are called unreserved. These include uppercase and lowercase letters, decimal digits, hyphen, period, underscore, and tilde.

  ALPHA  DIGIT  "-" / "." / "_" / "~"

Note that RFC 3986 lists fewer reserved punctuation marks than the older RFC 2396.

Spring Boot - How to log all requests and responses with exceptions in single place?

In order to log requests that result in 400 only:

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.io.FileUtils;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.AbstractRequestLoggingFilter;
import org.springframework.web.filter.OncePerRequestFilter;
import org.springframework.web.util.ContentCachingRequestWrapper;
import org.springframework.web.util.WebUtils;

/**
 * Implementation is partially copied from {@link AbstractRequestLoggingFilter} and modified to output request information only if request resulted in 400.
 * Unfortunately {@link AbstractRequestLoggingFilter} is not smart enough to expose {@link HttpServletResponse} value in afterRequest() method.
 */
@Component
public class RequestLoggingFilter extends OncePerRequestFilter {

    public static final String DEFAULT_AFTER_MESSAGE_PREFIX = "After request [";

    public static final String DEFAULT_AFTER_MESSAGE_SUFFIX = "]";

    private final boolean includeQueryString = true;
    private final boolean includeClientInfo = true;
    private final boolean includeHeaders = true;
    private final boolean includePayload = true;

    private final int maxPayloadLength = (int) (2 * FileUtils.ONE_MB);

    private final String afterMessagePrefix = DEFAULT_AFTER_MESSAGE_PREFIX;

    private final String afterMessageSuffix = DEFAULT_AFTER_MESSAGE_SUFFIX;

    /**
     * The default value is "false" so that the filter may log a "before" message
     * at the start of request processing and an "after" message at the end from
     * when the last asynchronously dispatched thread is exiting.
     */
    @Override
    protected boolean shouldNotFilterAsyncDispatch() {
        return false;
    }

    @Override
    protected void doFilterInternal(final HttpServletRequest request, final HttpServletResponse response, final FilterChain filterChain)
            throws ServletException, IOException {

        final boolean isFirstRequest = !isAsyncDispatch(request);
        HttpServletRequest requestToUse = request;

        if (includePayload && isFirstRequest && !(request instanceof ContentCachingRequestWrapper)) {
            requestToUse = new ContentCachingRequestWrapper(request, maxPayloadLength);
        }

        final boolean shouldLog = shouldLog(requestToUse);

        try {
            filterChain.doFilter(requestToUse, response);
        } finally {
            if (shouldLog && !isAsyncStarted(requestToUse)) {
                afterRequest(requestToUse, response, getAfterMessage(requestToUse));
            }
        }
    }

    private String getAfterMessage(final HttpServletRequest request) {
        return createMessage(request, this.afterMessagePrefix, this.afterMessageSuffix);
    }

    private String createMessage(final HttpServletRequest request, final String prefix, final String suffix) {
        final StringBuilder msg = new StringBuilder();
        msg.append(prefix);
        msg.append("uri=").append(request.getRequestURI());

        if (includeQueryString) {
            final String queryString = request.getQueryString();
            if (queryString != null) {
                msg.append('?').append(queryString);
            }
        }

        if (includeClientInfo) {
            final String client = request.getRemoteAddr();
            if (StringUtils.hasLength(client)) {
                msg.append(";client=").append(client);
            }
            final HttpSession session = request.getSession(false);
            if (session != null) {
                msg.append(";session=").append(session.getId());
            }
            final String user = request.getRemoteUser();
            if (user != null) {
                msg.append(";user=").append(user);
            }
        }

        if (includeHeaders) {
            msg.append(";headers=").append(new ServletServerHttpRequest(request).getHeaders());
        }

        if (includeHeaders) {
            final ContentCachingRequestWrapper wrapper = WebUtils.getNativeRequest(request, ContentCachingRequestWrapper.class);
            if (wrapper != null) {
                final byte[] buf = wrapper.getContentAsByteArray();
                if (buf.length > 0) {
                    final int length = Math.min(buf.length, maxPayloadLength);
                    String payload;
                    try {
                        payload = new String(buf, 0, length, wrapper.getCharacterEncoding());
                    } catch (final UnsupportedEncodingException ex) {
                        payload = "[unknown]";
                    }
                    msg.append(";payload=").append(payload);
                }
            }
        }
        msg.append(suffix);
        return msg.toString();
    }

    private boolean shouldLog(final HttpServletRequest request) {
        return true;
    }

    private void afterRequest(final HttpServletRequest request, final HttpServletResponse response, final String message) {
        if (response.getStatus() == HttpStatus.BAD_REQUEST.value()) {
            logger.warn(message);
        }
    }

}

How to convert currentTimeMillis to a date in Java?

My Solution

public class CalendarUtils {

    public static String dateFormat = "dd-MM-yyyy hh:mm";
    private static SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat);

    public static String ConvertMilliSecondsToFormattedDate(String milliSeconds){
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(Long.parseLong(milliSeconds));
        return simpleDateFormat.format(calendar.getTime());
    }
}

How to print a int64_t type in C

The C99 way is

#include <inttypes.h>
int64_t my_int = 999999999999999999;
printf("%" PRId64 "\n", my_int);

Or you could cast!

printf("%ld", (long)my_int);
printf("%lld", (long long)my_int); /* C89 didn't define `long long` */
printf("%f", (double)my_int);

If you're stuck with a C89 implementation (notably Visual Studio) you can perhaps use an open source <inttypes.h> (and <stdint.h>): http://code.google.com/p/msinttypes/

How to print something to the console in Xcode?

3 ways to do this:

In C Language (Command Line Tool) Works with Objective C, too:

printf("Hello World");

In Objective C:

NSLog(@"Hello, World!");

In Objective C with variables:

NSString * myString = @"Hello World";
NSLog(@"%@", myString);

In the code with variables, the variable created with class, NSString was outputted be NSLog. The %@ represents text as a variable.

How to ssh from within a bash script?

  1. If you want the password prompt to go away then use key based authentication (described here).

  2. To run commands remotely over ssh you have to give them as an argument to ssh, like the following:

root@host:~ # ssh root@www 'ps -ef | grep apache | grep -v grep | wc -l'

How to open an elevated cmd using command line for Windows?

..

@ECHO OFF
SETLOCAL EnableDelayedExpansion EnableExtensions
NET SESSION >nul 2>&1
IF %ERRORLEVEL% NEQ 0 GOTO ELEVATE
GOTO :EOF

:ELEVATE
SET this="%CD%"
SET this=!this:\=\\!

MSHTA "javascript: var shell = new ActiveXObject('shell.application'); shell.ShellExecute('CMD', '/K CD /D \"!this!\"', '', 'runas', 1);close();"
EXIT 1

save this script as "god.cmd" in your system32 or whatever your path is directing to....

if u open a cmd in e:\mypictures\ and type god it will ask you for credentials and put you back to that same place as the administrator...

How to keep a git branch in sync with master

Yeah I agree with your approach. To merge mobiledevicesupport into master you can use

git checkout master
git pull origin master //Get all latest commits of master branch
git merge mobiledevicesupport

Similarly you can also merge master in mobiledevicesupport.

Q. If cross merging is an issue or not.

A. Well it depends upon the commits made in mobile* branch and master branch from the last time they were synced. Take this example: After last sync, following commits happen to these branches

Master branch: A -> B -> C [where A,B,C are commits]
Mobile branch: D -> E

Now, suppose commit B made some changes to file a.txt and commit D also made some changes to a.txt. Let us have a look at the impact of each operation of merging now,

git checkout master //Switches to master branch
git pull // Get the commits you don't have. May be your fellow workers have made them.
git merge mobiledevicesupport // It will try to add D and E in master branch.

Now, there are two types of merging possible

  1. Fast forward merge
  2. True merge (Requires manual effort)

Git will first try to make FF merge and if it finds any conflicts are not resolvable by git. It fails the merge and asks you to merge. In this case, a new commit will occur which is responsible for resolving conflicts in a.txt.

So Bottom line is Cross merging is not an issue and ultimately you have to do it and that is what syncing means. Make sure you dirty your hands in merging branches before doing anything in production.

seek() function?

For strings, forget about using WHENCE: use f.seek(0) to position at beginning of file and f.seek(len(f)+1) to position at the end of file. Use open(file, "r+") to read/write anywhere in a file. If you use "a+" you'll only be able to write (append) at the end of the file regardless of where you position the cursor.

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

Same applies for guard statements. The same error message lead me to this post and answer (thanks @nhgrif).

The code: Print the last name of the person only if the middle name is less than four characters.

func greetByMiddleName(name: (first: String, middle: String?, last: String?)) {
    guard let Name = name.last where name.middle?.characters.count < 4 else {
        print("Hi there)")
        return
    }
    print("Hey \(Name)!")
}

Until I declared last as an optional parameter I was seeing the same error.

Forbidden You don't have permission to access / on this server

The problem lies in https.conf file!

# Virtual hosts
# Include conf/extra/httpd-vhosts.conf

The error occurs when hash(#) is removed or messed around with. These two lines should appear as shown above.

How to preSelect an html dropdown list with php?

I suppose that you are using an array to create your select form input. In that case, use an array:

<?php
    $selected = array( $_REQUEST['yesnofine'] => 'selected="selected"' );
    $fields = array(1 => 'Yes', 2 => 'No', 3 => 'Fine');
 ?>
  <select name=‘yesnofine'>
 <?php foreach ($fields as $k => $v): ?>
  <option value="<?php echo $k;?>" <?php @print($selected[$k]);?>><?php echo $v;?></options>
 <?php endforeach; ?>
 </select>

If not, you may just unroll the above loop, and still use an array.

 <option value="1" <?php @print($selected[$k]);?>>Yes</options>
 <option value="2" <?php @print($selected[$k]);?>>No</options>
 <option value="3" <?php @print($selected[$k]);?>>Fine</options>

Notes that I don't know:

  • how you are naming your input, so I made up a name for it.
  • which way you are handling your form input on server side, I used $_REQUEST,

You will have to adapt the code to match requirements of the framework you are using, if any.

Also, it is customary in many frameworks to use the alternative syntax in view dedicated scripts.

Animate a custom Dialog

I meet the same problem,but ,at last I solve the problem by followed way

((ViewGroup)dialog.getWindow().getDecorView())
.getChildAt(0).startAnimation(AnimationUtils.loadAnimation(
context,android.R.anim.slide_in_left));

Best way to simulate "group by" from bash?

sort ip_addresses | uniq -c

This will print the count first, but other than that it should be exactly what you want.

Find a value anywhere in a database

-- exec pSearchAllTables 'M54*'

ALTER PROC pSearchAllTables (@SearchStr NVARCHAR(100))
AS
BEGIN
    -- A procedure to search all tables in a database for a value
    -- Note: Use * or % for wildcard

    DECLARE 
        @Results TABLE([Schema.Table.ColumnName] NVARCHAR(370), ColumnValue NVARCHAR(3630))

    SET NOCOUNT ON

    DECLARE 
        @TableName NVARCHAR(256) = ''
        , @ColumnName NVARCHAR(128)     
        , @SearchStr2 NVARCHAR(110) = QUOTENAME(REPLACE(@SearchStr, '*', '%'), '''')

    WHILE @TableName IS NOT NULL
        BEGIN
            SET @ColumnName = ''
            SET @TableName = 
            (
                SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
                FROM INFORMATION_SCHEMA.TABLES
                WHERE TABLE_TYPE = 'BASE TABLE'
                AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
                AND OBJECTPROPERTY(OBJECT_ID(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)), 'IsMSShipped') = 0
            )

            WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
                BEGIN
                    SET @ColumnName =
                    (
                        SELECT MIN(QUOTENAME(COLUMN_NAME))
                        FROM INFORMATION_SCHEMA.COLUMNS
                        WHERE TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                        AND TABLE_NAME  = PARSENAME(@TableName, 1)
                        AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
                        AND QUOTENAME(COLUMN_NAME) > @ColumnName
                    )

                    IF @ColumnName IS NOT NULL
                        BEGIN
                            INSERT INTO @Results 
                            EXEC ('SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) FROM ' + @TableName + ' (NOLOCK) WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2)

                        END

                END 

        END

    SELECT 
        [Schema.Table.ColumnName]
        , ColumnValue 
    FROM @Results
    GROUP BY 
        [Schema.Table.ColumnName]
        , ColumnValue 

END

Find which version of package is installed with pip

import pkg_resources
packages = [dist.project_name for dist in pkg_resources.working_set]
try:
   for count, item in enumerate(packages):
      print(item, pkg_resources.get_distribution(item).version)
except:
    pass here

The indentations might not be perfect. The reason I am using a Try- Except block is that few library names will throw errors because of parsing the library names to process the versions. even though packages variable will contain all the libraries install in your environment.

How to echo text during SQL script execution in SQLPLUS

You can use SET ECHO ON in the beginning of your script to achieve that, however, you have to specify your script using @ instead of < (also had to add EXIT at the end):

test.sql

SET ECHO ON

SELECT COUNT(1) FROM dual;

SELECT COUNT(1) FROM (SELECT 1 FROM dual UNION SELECT 2 FROM dual);

EXIT

terminal

sqlplus hr/oracle@orcl @/tmp/test.sql > /tmp/test.log

test.log

SQL> 
SQL> SELECT COUNT(1) FROM dual;

  COUNT(1)
----------
     1

SQL> 
SQL> SELECT COUNT(1) FROM (SELECT 1 FROM dual UNION SELECT 2 FROM dual);

  COUNT(1)
----------
     2

SQL> 
SQL> EXIT

How do I format date in jQuery datetimepicker?

you can use :

$('#timePicker').datetimepicker({
        format:'d.m.Y H:i',
        minDate: ge_today_date(new Date())
});

 function ge_today_date(date) {
     var day = date.getDate();
     var month = date.getMonth() + 1;
     var year = date.getFullYear().toString().slice(2);
     return day + '-' + month + '-' + year;
 }

jQuery: get the file name selected from <input type="file" />

$('input[type=file]').change(function(e){
    $(this).parents('.parent-selector').find('.element-to-paste-filename').text(e.target.files[0].name);
});

This code will not show C:\fakepath\ before file name in Google Chrome in case of using .val().

Access to the requested object is only available from the local network phpmyadmin

after putting "Allow from all", you need to restart your xampp to apply the setting. thanks

How to remove items from a list while iterating?

The other answers are correct that it is usually a bad idea to delete from a list that you're iterating. Reverse iterating avoids the pitfalls, but it is much more difficult to follow code that does that, so usually you're better off using a list comprehension or filter.

There is, however, one case where it is safe to remove elements from a sequence that you are iterating: if you're only removing one item while you're iterating. This can be ensured using a return or a break. For example:

for i, item in enumerate(lst):
    if item % 4 == 0:
        foo(item)
        del lst[i]
        break

This is often easier to understand than a list comprehension when you're doing some operations with side effects on the first item in a list that meets some condition and then removing that item from the list immediately after.

Run git pull over all subdirectories

Run the following from the parent directory, plugins in this case:

find . -type d -depth 1 -exec git --git-dir={}/.git --work-tree=$PWD/{} pull origin master \;

To clarify:

  • find . searches the current directory
  • -type d to find directories, not files
  • -depth 1 for a maximum depth of one sub-directory
  • -exec {} \; runs a custom command for every find
  • git --git-dir={}/.git --work-tree=$PWD/{} pull git pulls the individual directories

To play around with find, I recommend using echo after -exec to preview, e.g.:

find . -type d -depth 1 -exec echo git --git-dir={}/.git --work-tree=$PWD/{} status \;

Note: if the -depth 1 option is not available, try -mindepth 1 -maxdepth 1.

What is phtml, and when should I use a .phtml extension rather than .php?

You can choose any extension in the world if you setup Apache correctly. You could use .html to do PHP if you set up in your Apache config.

In conclusion, extension has nothing to do with the app or website itself. You can use the one you want, but normaly, use .php (to not reinvent the wheel)

But in 2019, you should use routing and forgot about extension at the end.

I recommend you using Laravel.

In answer to @KingCrunch: True, Apache not use it by default but you can easily use it if you change config. But this it not recommended since everybody know that it not really an option.

I already saw .html files that executed PHP using the html extension.

Define a fixed-size list in Java

A Java list is a collection of objects ... the elements of a list. The size of the list is the number of elements in that list. If you want that size to be fixed, that means that you cannot either add or remove elements, because adding or removing elements would violate your "fixed size" constraint.

The simplest way to implement a "fixed sized" list (if that is really what you want!) is to put the elements into an array and then Arrays.asList(array) to create the list wrapper. The wrapper will allow you to do operations like get and set, but the add and remove operations will throw exceptions.

And if you want to create a fixed-sized wrapper for an existing list, then you could use the Apache commons FixedSizeList class. But note that this wrapper can't stop something else changing the size of the original list, and if that happens the wrapped list will presumably reflect those changes.


On the other hand, if you really want a list type with a fixed limit (or limits) on its size, then you'll need to create your own List class to implement this. For example, you could create a wrapper class that implements the relevant checks in the various add / addAll and remove / removeAll / retainAll operations. (And in the iterator remove methods if they are supported.)

So why doesn't the Java Collections framework implement these? Here's why I think so:

  1. Use-cases that need this are rare.
  2. The use-cases where this is needed, there are different requirements on what to do when an operation tries to break the limits; e.g. throw exception, ignore operation, discard some other element to make space.
  3. A list implementation with limits could be problematic for helper methods; e.g. Collections.sort.

Where does R store packages?

Thanks for the direction from the above two answerers. James Thompson's suggestion worked best for Windows users.

  1. Go to where your R program is installed. This is referred to as R_Home in the literature. Once you find it, go to the /etc subdirectory.

    C:\R\R-2.10.1\etc
    
  2. Select the file in this folder named Rprofile.site. I open it with VIM. You will find this is a bare-bones file with less than 20 lines of code. I inserted the following inside the code:

    # my custom library path
    .libPaths("C:/R/library")
    

    (The comment added to keep track of what I did to the file.)

  3. In R, typing the .libPaths() function yields the first target at C:/R/Library

NOTE: there is likely more than one way to achieve this, but other methods I tried didn't work for some reason.

How can I check for IsPostBack in JavaScript?

There is an even easier way that does not involve writing anything in the code behind: Just add this line to your javascript:

if(<%=(Not Page.IsPostBack).ToString().ToLower()%>){//Your JavaScript goodies here}

or

if(<%=(Page.IsPostBack).ToString().ToLower()%>){//Your JavaScript goodies here}

How do you install Boost on MacOS?

Install Xcode from the mac app store. Then use the command:

  /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

the above will install homebrew and allow you to use brew in terminal

then just use command :

brew install boost

which would then install the boost libraries to <your macusername>/usr/local/Cellar/boost

Angular exception: Can't bind to 'ngForIn' since it isn't a known native property

Since this is at least the third time I've wasted more than 5 min on this problem I figured I'd post the Q & A. I hope it helps someone else down the road... probably me!

I typed in instead of of in the ngFor expression.

Befor 2-beta.17, it should be:

<div *ngFor="#talk of talks">

As of beta.17, use the let syntax instead of #. See the UPDATE further down for more info.


Note that the ngFor syntax "desugars" into the following:

<template ngFor #talk [ngForOf]="talks">
  <div>...</div>
</template>

If we use in instead, it turns into

<template ngFor #talk [ngForIn]="talks">
  <div>...</div>
</template>

Since ngForIn isn't an attribute directive with an input property of the same name (like ngIf), Angular then tries to see if it is a (known native) property of the template element, and it isn't, hence the error.

UPDATE - as of 2-beta.17, use the let syntax instead of #. This updates to the following:

<div *ngFor="let talk of talks">

Note that the ngFor syntax "desugars" into the following:

<template ngFor let-talk [ngForOf]="talks">
  <div>...</div>
</template>

If we use in instead, it turns into

<template ngFor let-talk [ngForIn]="talks">
  <div>...</div>
</template>

How to use format() on a moment.js duration?

This works for me:

moment({minutes: 150}).format('HH:mm') // 01:30

How do I save and restore multiple variables in python?

If you need to save multiple objects, you can simply put them in a single list, or tuple, for instance:

import pickle

# obj0, obj1, obj2 are created here...

# Saving the objects:
with open('objs.pkl', 'w') as f:  # Python 3: open(..., 'wb')
    pickle.dump([obj0, obj1, obj2], f)

# Getting back the objects:
with open('objs.pkl') as f:  # Python 3: open(..., 'rb')
    obj0, obj1, obj2 = pickle.load(f)

If you have a lot of data, you can reduce the file size by passing protocol=-1 to dump(); pickle will then use the best available protocol instead of the default historical (and more backward-compatible) protocol. In this case, the file must be opened in binary mode (wb and rb, respectively).

The binary mode should also be used with Python 3, as its default protocol produces binary (i.e. non-text) data (writing mode 'wb' and reading mode 'rb').

How to convert HTML file to word?

When doing this I found it easiest to:

  1. Visit the page in a web browser
  2. Save the page using the web browser with .htm extension (and maybe a folder with support files)
  3. Start Word and open the saved htmfile (Word will open it correctly)
  4. Make any edits if needed
  5. Select Save As and then choose the extension you would like doc, docx, etc.

Change event on select with knockout binding, how can I know if it is a real change?

Try this one:

self.GetHierarchyNodeList = function (data, index, event)
{
    debugger;
    if (event.type != "change") {
        return;
    }        
} 

event.type == "change"
event.type == "load" 

CSS background-image-opacity?

If the background doesn't have to repeat, you can use the sprite technique (sliding-doors) where you put all the images with differing opacity into one (next to each other) and then just shift them around with background-position.

Or you could declare the same partially transparent background image more than once, if your target browser supports multiple backgrounds (Firefox 3.6+, Safari 1.0+, Chrome 1.3+, Opera 10.5+, Internet Explorer 9+). The opacity of those multiple images should add up, the more backgrounds you define.

This process of combining transparencies is called Alpha Blending and calculated as (thanks @IainFraser):

a? = a1 + a2(1-a1) where a ranges between 0 and 1.

Reactjs convert html string to jsx

i start using npm package called react-html-parser

Remove HTML tags from a String

Another way is to use javax.swing.text.html.HTMLEditorKit to extract the text.

import java.io.*;
import javax.swing.text.html.*;
import javax.swing.text.html.parser.*;

public class Html2Text extends HTMLEditorKit.ParserCallback {
    StringBuffer s;

    public Html2Text() {
    }

    public void parse(Reader in) throws IOException {
        s = new StringBuffer();
        ParserDelegator delegator = new ParserDelegator();
        // the third parameter is TRUE to ignore charset directive
        delegator.parse(in, this, Boolean.TRUE);
    }

    public void handleText(char[] text, int pos) {
        s.append(text);
    }

    public String getText() {
        return s.toString();
    }

    public static void main(String[] args) {
        try {
            // the HTML to convert
            FileReader in = new FileReader("java-new.html");
            Html2Text parser = new Html2Text();
            parser.parse(in);
            in.close();
            System.out.println(parser.getText());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

ref : Remove HTML tags from a file to extract only the TEXT

How can I increase a scrollbar's width using CSS?

My experience with trying to use CSS to modify the scroll bars is don't. Only IE will let you do this.

Is there a “not in” operator in JavaScript for checking object properties?

It seems wrong to me to set up an if/else statement just to use the else portion...

Just negate your condition, and you'll get the else logic inside the if:

if (!(id in tutorTimes)) { ... }

How to create a data file for gnuplot?

I was having the exact same issue. The problem that I was having is that I hadn't saved the .plt file that I was typing into yet. The fix: I saved the .plt file in the same directory as the data that I was trying to plot and suddenly it worked! If they are in the same directory, you don't even need to specify a path, you can just put in the file name.

Below is exactly what was happening to me, and how I fixed it. The first line shows the problem we were both having. I saved in the second line, and the third line worked!

gnuplot> plot 'c:/Documents and Settings/User/Desktop/data.dat'
         warning: Skipping unreadable file c:/Documents and Settings/User/Desktop/data.dat
         No data in plot

gnuplot> save 'c:/Documents and Settings/User/Desktop/myfile.plt'

gnuplot> plot 'c:/Documents and Settings/User/Desktop/data.dat'

Get bytes from std::string in C++

If this is just plain vanilla C, then:

strcpy(buffer, text.c_str());

Assuming that buffer is allocated and large enough to hold the contents of 'text', which is the assumption in your original code.

If encrypt() takes a 'const char *' then you can use

encrypt(text.c_str())

and you do not need to copy the string.

Spark - SELECT WHERE or filtering?

As Yaron mentioned, there isn't any difference between where and filter.

filter is an overloaded method that takes a column or string argument. The performance is the same, regardless of the syntax you use.

filter overloaded method

We can use explain() to see that all the different filtering syntaxes generate the same Physical Plan. Suppose you have a dataset with person_name and person_country columns. All of the following code snippets will return the same Physical Plan below:

df.where("person_country = 'Cuba'").explain()
df.where($"person_country" === "Cuba").explain()
df.where('person_country === "Cuba").explain()
df.filter("person_country = 'Cuba'").explain()

These all return this Physical Plan:

== Physical Plan ==
*(1) Project [person_name#152, person_country#153]
+- *(1) Filter (isnotnull(person_country#153) && (person_country#153 = Cuba))
   +- *(1) FileScan csv [person_name#152,person_country#153] Batched: false, Format: CSV, Location: InMemoryFileIndex[file:/Users/matthewpowers/Documents/code/my_apps/mungingdata/spark2/src/test/re..., PartitionFilters: [], PushedFilters: [IsNotNull(person_country), EqualTo(person_country,Cuba)], ReadSchema: struct<person_name:string,person_country:string>

The syntax doesn't change how filters are executed under the hood, but the file format / database that a query is executed on does. Spark will execute the same query differently on Postgres (predicate pushdown filtering is supported), Parquet (column pruning), and CSV files. See here for more details.

HTML input time in 24 format

Tested!

In Windows -> control panel -> Region -> Additional Settings -> Time -> Short Time:

Format your time as HH:mm

in the format

hh = 12 hours

HH = 24 hours

mm = minutes

tt = AM or PM

so to get the required result the format should be HH:mm and not hh:mm tt

How to make a submit out of a <a href...>...</a> link?

Something like this page ?

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="fr">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>BSO Communication</title>

<style type="text/css">
.submit {
    border : 0;
    background : url(ok.gif) left top no-repeat;
    height : 24px;
    width : 24px;
    cursor : pointer;
    text-indent : -9999px;
}
html:first-child .submit {
    padding-left : 1000px;
}
</style>
<!--[if IE]>
<style type="text/css">
.submit {
    text-indent : 0;
    color : expression(this.value = '');
}
</style>
<![endif]-->
</head>

<body>
    <h1>Display input submit as image with CSS</h1>

    <p>Take a look at <a href="/2007/07/26/afficher-un-input-submit-comme-une-image/">the related article</a> (in french).</p>
    <form action="" method="get">
        <fieldset>
            <legend>Some form</legend>
            <p class="field">
                <label for="input">Some value</label>

                <input type="text" id="input" name="value" />
                <input type="submit" class="submit" />
            </p>
        </fieldset>
    </form>

    <hr />
    <p>This page is part of the <a href="http://www.bsohq.fr">BSO Communication blog</a>.</p>

</body>
</html>

MySQL error - #1062 - Duplicate entry ' ' for key 2

In addition to Sabeen's answer:

The first column id is your primary key.
Don't insert '' into the primary key, but insert null instead.

INSERT INTO users
  (`id`,`title`,`firstname`,`lastname`,`company`,`address`,`city`,`county`
   ,`postcode`,`phone`,`mobile`,`category`,`email`,`password`,`userlevel`) 
VALUES     
  (null,'','John','Doe','company','Streeet','city','county'
  ,'postcode','phone','','category','[email protected]','','');

If it's an autoincrement key this will fix your problem.
If not make id an autoincrement key, and always insert null into it to trigger an autoincrement.

MySQL has a setting to autoincrement keys only on null insert or on both inserts of 0 and null. Don't count on this setting, because your code may break if you change server.
If you insert null your code will always work.

See: http://dev.mysql.com/doc/refman/5.0/en/example-auto-increment.html

Is JavaScript's "new" keyword considered harmful?

Another case for new is what I call Pooh Coding. Winnie the Pooh follows his tummy. I say go with the language you are using, not against it.

Chances are that the maintainers of the language will optimize the language for the idioms they try to encourage. If they put a new keyword into the language they probably think it makes sense to be clear when creating a new instance.

Code written following the language's intentions will increase in efficiency with each release. And code avoiding the key constructs of the language will suffer with time.

EDIT: And this goes well beyond performance. I can't count the times I've heard (or said) "why the hell did they do that?" when finding strange looking code. It often turns out that at the time when the code was written there was some "good" reason for it. Following the Tao of the language is your best insurance for not having your code ridiculed some years from now.

Using curl POST with variables defined in bash script functions

You don't need to pass the quotes enclosing the custom headers to curl. Also, your variables in the middle of the data argument should be quoted.

First, write a function that generates the post data of your script. This saves you from all sort of headaches concerning shell quoting and makes it easier to read an maintain the script than feeding the post data on curl's invocation line as in your attempt:

generate_post_data()
{
  cat <<EOF
{
  "account": {
    "email": "$email",
    "screenName": "$screenName",
    "type": "$theType",
    "passwordSettings": {
      "password": "$password",
      "passwordConfirm": "$password"
    }
  },
  "firstName": "$firstName",
  "lastName": "$lastName",
  "middleName": "$middleName",
  "locale": "$locale",
  "registrationSiteId": "$registrationSiteId",
  "receiveEmail": "$receiveEmail",
  "dateOfBirth": "$dob",
  "mobileNumber": "$mobileNumber",
  "gender": "$gender",
  "fuelActivationDate": "$fuelActivationDate",
  "postalCode": "$postalCode",
  "country": "$country",
  "city": "$city",
  "state": "$state",
  "bio": "$bio",
  "jpFirstNameKana": "$jpFirstNameKana",
  "jpLastNameKana": "$jpLastNameKana",
  "height": "$height",
  "weight": "$weight",
  "distanceUnit": "MILES",
  "weightUnit": "POUNDS",
  "heightUnit": "FT/INCHES"
}
EOF
}

It is then easy to use that function in the invocation of curl:

curl -i \
-H "Accept: application/json" \
-H "Content-Type:application/json" \
-X POST --data "$(generate_post_data)" "https://xxx:[email protected]/xxxxx/xxxx/xxxx"

This said, here are a few clarifications about shell quoting rules:

The double quotes in the -H arguments (as in -H "foo bar") tell bash to keep what's inside as a single argument (even if it contains spaces).

The single quotes in the --data argument (as in --data 'foo bar') do the same, except they pass all text verbatim (including double quote characters and the dollar sign).

To insert a variable in the middle of a single quoted text, you have to end the single quote, then concatenate with the double quoted variable, and re-open the single quote to continue the text: 'foo bar'"$variable"'more foo'.

Explanation of <script type = "text/template"> ... </script>

Those script tags are a common way to implement templating functionality (like in PHP) but on the client side.

By setting the type to "text/template", it's not a script that the browser can understand, and so the browser will simply ignore it. This allows you to put anything in there, which can then be extracted later and used by a templating library to generate HTML snippets.

Backbone doesn't force you to use any particular templating library - there are quite a few out there: Mustache, Haml, Eco,Google Closure template, and so on (the one used in the example you linked to is underscore.js). These will use their own syntax for you to write within those script tags.

FTP/SFTP access to an Amazon S3 Bucket

As other posters have pointed out, there are some limitations with the AWS Transfer for SFTP service. You need to closely align requirements. For example, there are no quotas, whitelists/blacklists, file type limits, and non key based access requires external services. There is also a certain overhead relating to user management and IAM, which can get to be a pain at scale.

We have been running an SFTP S3 Proxy Gateway for about 5 years now for our customers. The core solution is wrapped in a collection of Docker services and deployed in whatever context is needed, even on-premise or local development servers. The use case for us is a little different as our solution is focused data processing and pipelines vs a file share. In a Salesforce example, a customer will use SFTP as the transport method sending email, purchase...data to an SFTP/S3 enpoint. This is mapped an object key on S3. Upon arrival, the data is picked up, processed, routed and loaded to a warehouse. We also have fairly significant auditing requirements for each transfer, something the Cloudwatch logs for AWS do not directly provide.

As other have mentioned, rolling your own is an option too. Using AWS Lightsail you can setup a cluster, say 4, of $10 2GB instances using either Route 53 or an ELB.

In general, it is great to see AWS offer this service and I expect it to mature over time. However, depending on your use case, alternative solutions may be a better fit.

Replace the single quote (') character from a string

As for how to represent a single apostrophe as a string in Python, you can simply surround it with double quotes ("'") or you can escape it inside single quotes ('\'').

To remove apostrophes from a string, a simple approach is to just replace the apostrophe character with an empty string:

>>> "didn't".replace("'", "")
'didnt'

Using AngularJS date filter with UTC date

An evolved version of ossek solution

Custom filter is more appropriate, then you can use it anywhere in the project

js file

var myApp = angular.module('myApp',[]);

myApp.filter('utcdate', ['$filter','$locale', function($filter, $locale){

    return function (input, format) {
        if (!angular.isDefined(format)) {
            format = $locale['DATETIME_FORMATS']['medium'];
        }

        var date = new Date(input);
        var d = new Date()
        var _utc = new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(),  date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds());
        return $filter('date')(_utc, format)
    };

 }]);

in template

<p>This will convert UTC time to local time<p>
<span>{{dateTimeInUTC | utcdate :'MMM d, y h:mm:ss a'}}</span>

How to pass a list from Python, by Jinja2 to JavaScript

To pass some context data to javascript code, you have to serialize it in a way it will be "understood" by javascript (namely JSON). You also need to mark it as safe using the safe Jinja filter, to prevent your data from being htmlescaped.

You can achieve this by doing something like that:

The view

import json

@app.route('/')
def my_view():
    data = [1, 'foo']
    return render_template('index.html', data=json.dumps(data))

The template

<script type="text/javascript">
    function test_func(data) {
        console.log(data);
    }
    test_func({{ data|safe }})
</script>

Edit - exact answer

So, to achieve exactly what you want (loop over a list of items, and pass them to a javascript function), you'd need to serialize every item in your list separately. Your code would then look like this:

The view

import json

@app.route('/')
def my_view():
    data = [1, "foo"]
    return render_template('index.html', data=map(json.dumps, data))

The template

{% for item in data %}
    <span onclick=someFunction({{ item|safe }});>{{ item }}</span>
{% endfor %}

Edit 2

In my example, I use Flask, I don't know what framework you're using, but you got the idea, you just have to make it fit the framework you use.

Edit 3 (Security warning)

NEVER EVER DO THIS WITH USER-SUPPLIED DATA, ONLY DO THIS WITH TRUSTED DATA!

Otherwise, you would expose your application to XSS vulnerabilities!

How to get process ID of background process?

this is what I have done. Check it out, hope it can help.

#!/bin/bash
#
# So something to show.
echo "UNO" >  UNO.txt
echo "DOS" >  DOS.txt
#
# Initialize Pid List
dPidLst=""
#
# Generate background processes
tail -f UNO.txt&
dPidLst="$dPidLst $!"
tail -f DOS.txt&
dPidLst="$dPidLst $!"
#
# Report process IDs
echo PID=$$
echo dPidLst=$dPidLst
#
# Show process on current shell
ps -f
#
# Start killing background processes from list
for dPid in $dPidLst
do
        echo killing $dPid. Process is still there.
        ps | grep $dPid
        kill $dPid
        ps | grep $dPid
        echo Just ran "'"ps"'" command, $dPid must not show again.
done

Then just run it as: ./bgkill.sh with proper permissions of course

root@umsstd22 [P]:~# ./bgkill.sh
PID=23757
dPidLst= 23758 23759
UNO
DOS
UID        PID  PPID  C STIME TTY          TIME CMD
root      3937  3935  0 11:07 pts/5    00:00:00 -bash
root     23757  3937  0 11:55 pts/5    00:00:00 /bin/bash ./bgkill.sh
root     23758 23757  0 11:55 pts/5    00:00:00 tail -f UNO.txt
root     23759 23757  0 11:55 pts/5    00:00:00 tail -f DOS.txt
root     23760 23757  0 11:55 pts/5    00:00:00 ps -f
killing 23758. Process is still there.
23758 pts/5    00:00:00 tail
./bgkill.sh: line 24: 23758 Terminated              tail -f UNO.txt
Just ran 'ps' command, 23758 must not show again.
killing 23759. Process is still there.
23759 pts/5    00:00:00 tail
./bgkill.sh: line 24: 23759 Terminated              tail -f DOS.txt
Just ran 'ps' command, 23759 must not show again.
root@umsstd22 [P]:~# ps -f
UID        PID  PPID  C STIME TTY          TIME CMD
root      3937  3935  0 11:07 pts/5    00:00:00 -bash
root     24200  3937  0 11:56 pts/5    00:00:00 ps -f

Using BETWEEN in CASE SQL statement

You do not specify why you think it is wrong but I can se two dangers:

BETWEEN can be implemented differently in different databases sometimes it is including the border values and sometimes excluding, resulting in that 1 and 31 of january would end up NOTHING. You should test how you database does this.

Also, if RATE_DATE contains hours also 2010-01-31 might be translated to 2010-01-31 00:00 which also would exclude any row with an hour other that 00:00.

android studio 0.4.2: Gradle project sync failed error

Load Project:>Build, execution, Deployment:>(Check on)compiler Independent modules in parllel.

How can we run a test method with multiple parameters in MSTest?

It is unfortunately not supported in older versions of MSTest. Apparently there is an extensibility model and you can implement it yourself. Another option would be to use data-driven tests.

My personal opinion would be to just stick with NUnit though...

As of Visual Studio 2012, update 1, MSTest has a similar feature. See McAden's answer.

How to downgrade Node version

If you're on Windows I suggest manually uninstalling node and installing chocolatey to handle your node installation. choco is a great CLI for provisioning a ton of popular software.

Then you can just do,

choco install nodejs --version $VersionNumber

and if you already have it installed via chocolatey you can do,

choco uninstall nodejs 
choco install nodejs --version $VersionNumber

For example,

choco uninstall nodejs
choco install nodejs --version 12.9.1

How to copy files across computers using SSH and MAC OS X Terminal

You can do this with the scp command, which uses the ssh protocol to copy files across machines. It extends the syntax of cp to allow references to other systems:

scp username1@hostname1:/path/to/file username2@hostname2:/path/to/other/file

Copy something from this machine to some other machine:

scp /path/to/local/file username@hostname:/path/to/remote/file

Copy something from another machine to this machine:

scp username@hostname:/path/to/remote/file /path/to/local/file

Copy with a port number specified:

scp -P 1234 username@hostname:/path/to/remote/file /path/to/local/file

Programmatic equivalent of default(Type)

Why not call the method that returns default(T) with reflection ? You can use GetDefault of any type with:

    public object GetDefault(Type t)
    {
        return this.GetType().GetMethod("GetDefaultGeneric").MakeGenericMethod(t).Invoke(this, null);
    }

    public T GetDefaultGeneric<T>()
    {
        return default(T);
    }

Show hide div using codebehind

You can use a standard ASP.NET Panel and then set it's visible property in your code behind.

<asp:Panel ID="Panel1" runat="server" visible="false" />

To show panel in codebehind:

Panel1.Visible = true;

How to edit/save a file through Ubuntu Terminal

Normal text editors are nano, or vi.

For example:

root@user:# nano galfit.feedme

or

root@user:# vi galfit.feedme

How to easily resize/optimize an image size with iOS?

The easiest and most straightforward way to resize your images would be this

float actualHeight = image.size.height;
float actualWidth = image.size.width;
float imgRatio = actualWidth/actualHeight;
float maxRatio = 320.0/480.0;

if(imgRatio!=maxRatio){
    if(imgRatio < maxRatio){
        imgRatio = 480.0 / actualHeight;
        actualWidth = imgRatio * actualWidth;
        actualHeight = 480.0;
    }
    else{
        imgRatio = 320.0 / actualWidth;
        actualHeight = imgRatio * actualHeight;
        actualWidth = 320.0;
    }
}
CGRect rect = CGRectMake(0.0, 0.0, actualWidth, actualHeight);
UIGraphicsBeginImageContext(rect.size);
[image drawInRect:rect];
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

What are some good SSH Servers for windows?

copssh - OpenSSH for Windows

http://www.itefix.no/i2/copssh

Packages essential Cygwin binaries.

Can I run Keras model on gpu?

See if your script is running GPU in Task manager. If not, suspect your CUDA version is right one for the tensorflow version you are using, as the other answers suggested already.

Additionally, a proper CUDA DNN library for the CUDA version is required to run GPU with tensorflow. Download/extract it from here and put the DLL (e.g., cudnn64_7.dll) into CUDA bin folder (e.g., C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.1\bin).

Iteration ng-repeat only X times in AngularJs

This is the simplest workaround I could think of.

<span ng-repeat="n in [].constructor(5) track by $index">
{{$index}}
</span>

Here's a Plunker example.

How do I auto-hide placeholder text upon focus using css or jquery?

I like the css approach spiced with transitions. On Focus the placeholder fades out ;) Works also for textareas.

Thanks @Casey Chu for the great idea.

textarea::-webkit-input-placeholder, input::-webkit-input-placeholder { 
    color: #fff;
    opacity: 0.4;
    transition: opacity 0.5s;
    -webkit-transition: opacity 0.5s; 
}

textarea:focus::-webkit-input-placeholder, input:focus::-webkit-input-placeholder  { 
    opacity: 0;
}

Uninstall old versions of Ruby gems

You might need to set GEM_HOME for the cleanup to work. You can check what paths exist for gemfiles by running:

gem env

Take note of the GEM PATHS section.

In my case, for example, with gems installed in my user home:

export GEM_HOME="~/.gem/ruby/2.4.0"
gem cleanup

How to test android apps in a real device with Android Studio?

Step 1: Firstly, Go to the Settings in your real device whose device are used to run android app.

Step 2: After that go to the “About phone” if Developer Options is not shown in your device

Step 3: Then Tap 7 times on Build number to create Developer Options.

Step 4: After that go back and Developer options will be created in your device.

Step 5: After that go to Developer options and Enable USB debugging in your device as shown in figure below.

Step 6: Connect your device with your system via data cable and after that allow USB debugging message shown on your device and press OK.

Step 7: After that Go to the menu bar and Run app as shown in figure below.

Step 8: If real device is connected to your system then it will show Online. Now click on your Mobile phone device and you App will be run in real device.

Step 9: After that your Android app run in Real device.

Regards, Guruji Softwares (https://gurujisoftwares.com)

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

You need to load your JNI library.

System.loadLibrary loads the DLL from the JVM path (JDK bin path).

If you want to load an explicit file with a path, use System.load()

See also: Difference between System.load() and System.loadLibrary in Java

How to initialize a vector of vectors on a struct?

You use new to perform dynamic allocation. It returns a pointer that points to the dynamically allocated object.

You have no reason to use new, since A is an automatic variable. You can simply initialise A using its constructor:

vector<vector<int> > A(dimension, vector<int>(dimension));

Error: The type exists in both directories

The App_Code folder isn't intended to be used with MVC Projects (WAP).

Files in the App_Code folder gets compiled automatically as part of a special dll. If the Build Action property on the file is set to Compile, the same class will also get compiled as part of the main dll and you will end up with two copies.

Setting the Build Action property to None makes sure there is only one copy of the class in the project. The compiler will not catch any errors in the App_Code folder when building but Intellisense will still validate the code but compile-time errors won't show up until it is compiled on-the-fly.

The recommended solution is to put code in a normal folder and make sure the Build Action is set to Compile.

Full path from file input using jQuery

You can't: It's a security feature in all modern browsers.

For IE8, it's off by default, but can be reactivated using a security setting:

When a file is selected by using the input type=file object, the value of the value property depends on the value of the "Include local directory path when uploading files to a server" security setting for the security zone used to display the Web page containing the input object.

The fully qualified filename of the selected file is returned only when this setting is enabled. When the setting is disabled, Internet Explorer 8 replaces the local drive and directory path with the string C:\fakepath\ in order to prevent inappropriate information disclosure.

In all other current mainstream browsers I know of, it is also turned off. The file name is the best you can get.

More detailed info and good links in this question. It refers to getting the value server-side, but the issue is the same in JavaScript before the form's submission.

Git with SSH on Windows

I was trying to solve my issue with some of the answers above and for some reason it didn't work. I did switch to use the git extensions and this are the steps I did follow.

  1. I went to Tools -> Settings -> SSH -> Other ssh client
  2. Set this value to C:\Program Files\Git\usr\bin\ssh.exe
  3. Apply

I guess that this steps are just the same explained above. The only difference is that I used the Git Extensions User Interface instead of the terminal. Hope this help.

How do you perform address validation?

Validating it is a valid address is one thing.

But if you're trying to validate a given person lives at a given address, your only almost-guarantee would be a test mail to the address, and even that is not certain if the person is organised or knows somebody at that address.

Otherwise people could just specify an arbitrary random address which they know exists and it would mean nothing to you.

The best you can do for immediate results is request the user send a photographed / scanned copy of the head of their bank statement or some other proof-of-recent-residence, because at least then they have to work harder to forget it, and forging said things show up easily with a basic level of image forensic analysis.

Create Windows service from executable

Use NSSM( the non-Sucking Service Manager ) to run a .BAT or any .EXE file as a service.

http://nssm.cc/

  • Step 1: Download NSSM
  • Step 2: Install your sevice with nssm.exe install [serviceName]
  • Step 3: This will open a GUI which you will use to locate your executable

How does a hash table work?

Here's an explanation in layman's terms.

Let's assume you want to fill up a library with books and not just stuff them in there, but you want to be able to easily find them again when you need them.

So, you decide that if the person that wants to read a book knows the title of the book and the exact title to boot, then that's all it should take. With the title, the person, with the aid of the librarian, should be able to find the book easily and quickly.

So, how can you do that? Well, obviously you can keep some kind of list of where you put each book, but then you have the same problem as searching the library, you need to search the list. Granted, the list would be smaller and easier to search, but still you don't want to search sequentially from one end of the library (or list) to the other.

You want something that, with the title of the book, can give you the right spot at once, so all you have to do is just stroll over to the right shelf, and pick up the book.

But how can that be done? Well, with a bit of forethought when you fill up the library and a lot of work when you fill up the library.

Instead of just starting to fill up the library from one end to the other, you devise a clever little method. You take the title of the book, run it through a small computer program, which spits out a shelf number and a slot number on that shelf. This is where you place the book.

The beauty of this program is that later on, when a person comes back in to read the book, you feed the title through the program once more, and get back the same shelf number and slot number that you were originally given, and this is where the book is located.

The program, as others have already mentioned, is called a hash algorithm or hash computation and usually works by taking the data fed into it (the title of the book in this case) and calculates a number from it.

For simplicity, let's say that it just converts each letter and symbol into a number and sums them all up. In reality, it's a lot more complicated than that, but let's leave it at that for now.

The beauty of such an algorithm is that if you feed the same input into it again and again, it will keep spitting out the same number each time.

Ok, so that's basically how a hash table works.

Technical stuff follows.

First, there's the size of the number. Usually, the output of such a hash algorithm is inside a range of some large number, typically much larger than the space you have in your table. For instance, let's say that we have room for exactly one million books in the library. The output of the hash calculation could be in the range of 0 to one billion which is a lot higher.

So, what do we do? We use something called modulus calculation, which basically says that if you counted to the number you wanted (i.e. the one billion number) but wanted to stay inside a much smaller range, each time you hit the limit of that smaller range you started back at 0, but you have to keep track of how far in the big sequence you've come.

Say that the output of the hash algorithm is in the range of 0 to 20 and you get the value 17 from a particular title. If the size of the library is only 7 books, you count 1, 2, 3, 4, 5, 6, and when you get to 7, you start back at 0. Since we need to count 17 times, we have 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, and the final number is 3.

Of course modulus calculation isn't done like that, it's done with division and a remainder. The remainder of dividing 17 by 7 is 3 (7 goes 2 times into 17 at 14 and the difference between 17 and 14 is 3).

Thus, you put the book in slot number 3.

This leads to the next problem. Collisions. Since the algorithm has no way to space out the books so that they fill the library exactly (or the hash table if you will), it will invariably end up calculating a number that has been used before. In the library sense, when you get to the shelf and the slot number you wish to put a book in, there's already a book there.

Various collision handling methods exist, including running the data into yet another calculation to get another spot in the table (double hashing), or simply to find a space close to the one you were given (i.e. right next to the previous book assuming the slot was available also known as linear probing). This would mean that you have some digging to do when you try to find the book later, but it's still better than simply starting at one end of the library.

Finally, at some point, you might want to put more books into the library than the library allows. In other words, you need to build a bigger library. Since the exact spot in the library was calculated using the exact and current size of the library, it goes to follow that if you resize the library you might end up having to find new spots for all the books since the calculation done to find their spots has changed.

I hope this explanation was a bit more down to earth than buckets and functions :)

EC2 instance has no public DNS

For me problem was in subnet settings.

  1. Open https://console.aws.amazon.com/vpc
  2. Go to subnets in left menu
  3. Choose your subnet
  4. Modify auto-assigning IP settings to enable

How to enter in a Docker container already running with a new TTY

Update

As of docker 0.9, for the steps below to now work, one now has to update the /etc/default/docker file with the '-e lxc' to the docker daemon startup option before restarting the daemon (I did this by rebooting the host).

update to the /etc/default/docker file

This is all because...

...it [docker 0.9] contains a new "engine driver" abstraction to make possible the use of other API than LXC to start containers. It also provide a new engine driver based on a new API library (libcontainer) which is able to handle Control Groups without using LXC tools. The main issue is that if you are relying on lxc-attach to perform actions on your container, like starting a shell inside the container, which is insanely useful for developpment environment...

source

Please note that this will prevent the new host only networking optional feature of docker 0.11 from "working" and you will only see the loopback interface. bug report


It turns out that the solution to a different question was also the solution to this one:

...you can use docker ps -notrunc to get the full lxc container ID and then use lxc-attach -n <container_id> run bash in that container as root.

Update: You will soon need to use ps --no-trunc instead of ps -notrunc which is being deprecated.

enter image description here Find the full container ID

enter image description here Enter the lxc attach command.

enter image description here Top shows my apache process running that docker started.

How should I pass an int into stringWithFormat?

Keep in mind that @"%d" will only work on 32 bit. Once you start using NSInteger for compatibility if you ever compile for a 64 bit platform, you should use @"%ld" as your format specifier.

Print newline in PHP in single quotes

No, because single-quotes even inhibit hex code replacement.

echo 'Hello, world!' . "\xA";

Can I have a video with transparent background using HTML5 video tag?

Mp4 files can be playable with transparent background using seeThrou Js library. All you need to combine actual video and alpha channel in the single video. Also make sure to keep video height dimension below 1400 px as some of the old iphone devices wont play videos with dimension more than 2000. This is pretty useful in safari desktop and mobile devices which doesnt support webm at this time.

more details can be found in the below link https://github.com/m90/seeThru

HEAD and ORIG_HEAD in Git

HEAD is (direct or indirect, i.e. symbolic) reference to the current commit. It is a commit that you have checked in the working directory (unless you made some changes, or equivalent), and it is a commit on top of which "git commit" would make a new one. Usually HEAD is symbolic reference to some other named branch; this branch is currently checked out branch, or current branch. HEAD can also point directly to a commit; this state is called "detached HEAD", and can be understood as being on unnamed, anonymous branch.

And @ alone is a shortcut for HEAD, since Git 1.8.5

ORIG_HEAD is previous state of HEAD, set by commands that have possibly dangerous behavior, to be easy to revert them. It is less useful now that Git has reflog: HEAD@{1} is roughly equivalent to ORIG_HEAD (HEAD@{1} is always last value of HEAD, ORIG_HEAD is last value of HEAD before dangerous operation).

For more information read git(1) manpage / [gitrevisions(7) manpage][git-revisions], Git User's Manual, the Git Community Book and Git Glossary

DISTINCT clause with WHERE

You can use ROW_NUMBER(). You can specify where conditions as well. (e.g. Name LIKE'MyName% in the following query)

SELECT  *
FROM    (SELECT ID, Name, Email,
            ROW_NUMBER() OVER (PARTITION BY Email ORDER BY ID) AS RowNumber
     FROM   MyTable
     WHERE  Name LIKE 'MyName%') AS a
WHERE   a.RowNumber = 1

How do I dynamically set the selected option of a drop-down list using jQuery, JavaScript and HTML?

Here it goes.

_x000D_
_x000D_
// Select by value_x000D_
$('select[name="options"]').find('option[value="3"]').attr("selected",true);_x000D_
_x000D_
// Select by text_x000D_
//$('select[name="options"]').find('option:contains("Third")').attr("selected",true);
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<html>_x000D_
<body>_x000D_
<select name="options">_x000D_
      <option value="1">First</option>_x000D_
      <option value="2">Second</option>_x000D_
      <option value="3">Third</option>_x000D_
</select>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

AWS ssh access 'Permission denied (publickey)' issue

For Debian EC2 instances, the user is admin.

What REALLY happens when you don't free after malloc?

It depends on the scope of the project that you're working on. In the context of your question, and I mean just your question, then it doesn't matter.

For a further explanation (optional), some scenarios I have noticed from this whole discussion is as follow:

(1) - If you're working in an embedded environment where you cannot rely on the main OS' to reclaim the memory for you, then you should free them since memory leaks can really crash the program if done unnoticed.

(2) - If you're working on a personal project where you won't disclose it to anyone else, then you can skip it (assuming you're using it on the main OS') or include it for "best practices" sake.

(3) - If you're working on a project and plan to have it open source, then you need to do more research into your audience and figure out if freeing the memory would be the better choice.

(4) - If you have a large library and your audience consisted of only the main OS', then you don't need to free it as their OS' will help them to do so. In the meantime, by not freeing, your libraries/program may help to make the overall performance snappier since the program does not have to close every data structure, prolonging the shutdown time (imagine a very slow excruciating wait to shut down your computer before leaving the house...)

I can go on and on specifying which course to take, but it ultimately depends on what you want to achieve with your program. Freeing memory is considered good practice in some cases and not so much in some so it ultimately depends on the specific situation you're in and asking the right questions at the right time. Good luck!

Disabling of EditText in Android

I use google newly released Material Design Library. In my case, it works when I use android:focusable="false" and android:cursorVisible="false"

<com.google.android.material.textfield.TextInputLayout
                    android:id="@+id/to_time_input_layout"
                    app:endIconMode="custom"
                    app:endIconDrawable="@drawable/ic_clock"
                    app:endIconContentDescription="ToTime"
                    app:endIconTint="@color/colorAccent"
                    style="@style/OutlinedEditTextStyle"
                    android:hint="To Time">

                    <com.google.android.material.textfield.TextInputEditText
                        android:id="@+id/to_time_edit_text"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:focusable="false"
                        android:cursorVisible="false" />

</com.google.android.material.textfield.TextInputLayout>

convert epoch time to date

Please take care that the epoch time is in second and Date object accepts Long value which is in milliseconds. Hence you would have to multiply epoch value with 1000 to use it as long value . Like below :-

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss");
sdf.setTimeZone(TimeZone.getTimeZone(timeZone));
Long dateLong=Long.parseLong(sdf.format(epoch*1000));

Disable scrolling in an iPhone web application?

document.ontouchmove = function(e){ 
    e.preventDefault(); 
}

is actually the best choice i found out it allows you to still be able to tap on input fields as well as drag things using jQuery UI draggable but it stops the page from scrolling.

How do I unlock a SQLite database?

This link solve the problem. : When Sqlite gives : Database locked error It solved my problem may be useful to you.

And you can use begin transaction and end transaction to not make database locked in future.

How to use ArrayAdapter<myClass>

Subclass the ArrayAdapter and override the method getView() to return your own view that contains the contents that you want to display.

How to find third or n?? maximum salary from salary table?

Try this

SELECT TOP 1 salary FROM (
   SELECT TOP 3 salary 
   FROM employees 
   ORDER BY salary DESC) AS emp 
ORDER BY salary ASC

For 3 you can replace any value...

jQuery - how to write 'if not equal to' (opposite of ==)

if ("one" !== 1 )

would evaluate as true, the string "one" is not equal to the number 1

Write Base64-encoded image to file

import java.util.Base64;

.... Just making it clear that this answer uses the java.util.Base64 package, without using any third-party libraries.

String crntImage=<a valid base 64 string>

byte[] data = Base64.getDecoder().decode(crntImage);

try( OutputStream stream = new FileOutputStream("d:/temp/abc.pdf") ) 
{
   stream.write(data);
}
catch (Exception e) 
{
   System.err.println("Couldn't write to file...");
}

Reading local text file into a JavaScript array

Using Node.js

sync mode:

var fs = require("fs");
var text = fs.readFileSync("./mytext.txt");
var textByLine = text.split("\n")

async mode:

var fs = require("fs");
fs.readFile("./mytext.txt", function(text){
    var textByLine = text.split("\n")
});

UPDATE

As of at least Node 6, readFileSync returns a Buffer, so it must first be converted to a string in order for split to work:

var text = fs.readFileSync("./mytext.txt").toString('utf-8');

Or

var text = fs.readFileSync("./mytext.txt", "utf-8");

No suitable driver found for 'jdbc:mysql://localhost:3306/mysql

In this particular case (assuming that the Class#forName() didn't throw an exception; your code is namely continuing with running instead of throwing the exception), this SQLException means that Driver#acceptsURL() has returned false for any of the loaded drivers.

And indeed, your JDBC URL is wrong:

String url = "'jdbc:mysql://localhost:3306/mysql";

Remove the singlequote:

String url = "jdbc:mysql://localhost:3306/mysql";

See also:

How to instantiate, initialize and populate an array in TypeScript?

If you really want to have named parameters plus have your objects be instances of your class, you can do the following:

class bar {
    constructor (options?: {length: number; height: number;}) {
        if (options) {
            this.length = options.length;
            this.height = options.height;
        }
    }
    length: number;
    height: number;
}

class foo {
    bars: bar[] = new Array();
}

var ham = new foo();
ham.bars = [
    new bar({length: 4, height: 2}),
    new bar({length: 1, height: 3})
];

Also here's the related item on typescript issue tracker.

Moment.js get day name from date

var mydate = "2017-06-28T00:00:00";
var weekDayName =  moment(mydate).format('ddd');
console.log(weekDayName);

Result: Wed

var mydate = "2017-06-28T00:00:00";
var weekDayName =  moment(mydate).format('dddd');
console.log(weekDayName);

Result: Wednesday

Eventviewer eventid for lock and unlock

You will need to enable logging of these events. Do so by opening the group policy editor:

run -> gpedit.msc

and configuring the following category:

Computer Configuration ->
Windows Settings ->
Security Settings ->
Advanced Audit Policy Configuration ->
System Audit Policies - Local Group Policy Object ->
Logon/Logoff ->
Audit Other Login/Logoff Events

(In the Explain tab it says "... allows you to audit ... Locking and unlocking a workstation".)

SQL Inner join 2 tables with multiple column conditions and update

UPDATE
    T1
SET
    T1.Inci = T2.Inci 
FROM
    T1
INNER JOIN
    T2
ON
    T1.Brands = T2.Brands
AND
    T1.Category= T2.Category
AND
    T1.Date = T2.Date

PHP How to fix Notice: Undefined variable:

It looks like you don't have any records that match your query, so you'd want to return an empty array (or null or something) if the number of rows == 0.

How to replace multiple strings in a file using PowerShell

One option is to chain the -replace operations together. The ` at the end of each line escapes the newline, causing PowerShell to continue parsing the expression on the next line:

$original_file = 'path\filename.abc'
$destination_file =  'path\filename.abc.new'
(Get-Content $original_file) | Foreach-Object {
    $_ -replace 'something1', 'something1aa' `
       -replace 'something2', 'something2bb' `
       -replace 'something3', 'something3cc' `
       -replace 'something4', 'something4dd' `
       -replace 'something5', 'something5dsf' `
       -replace 'something6', 'something6dfsfds'
    } | Set-Content $destination_file

Another option would be to assign an intermediate variable:

$x = $_ -replace 'something1', 'something1aa'
$x = $x -replace 'something2', 'something2bb'
...
$x

Sorting string array in C#

If you have problems with numbers (say 1, 2, 10, 12 which will be sorted 1, 10, 12, 2) you can use LINQ:

var arr = arr.OrderBy(x=>x).ToArray();

filter: progid:DXImageTransform.Microsoft.gradient is not working in ie7

You didn't specify a GradientType:

background: #f0f0f0; /* Old browsers */
background: -moz-linear-gradient(top, #ffffff 0%, #eeeeee 100%); /* FF3.6+ */
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,#ffffff), color-stop(100%,#eeeeee)); /* Chrome,Safari4+ */
background: -webkit-linear-gradient(top, #ffffff 0%,#eeeeee 100%); /* Chrome10+,Safari5.1+ */
background: -o-linear-gradient(top, #ffffff 0%,#eeeeee 100%); /* Opera11.10+ */
background: -ms-linear-gradient(top, #ffffff 0%,#eeeeee 100%); /* IE10+ */
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#ffffff', endColorstr='#eeeeee',GradientType=0 ); /* IE6-9 */
background: linear-gradient(top, #ffffff 0%,#eeeeee 100%); /* W3C */

source: http://www.colorzilla.com/gradient-editor/

Declare and initialize a Dictionary in Typescript

I agree with thomaux that the initialization type checking error is a TypeScript bug. However, I still wanted to find a way to declare and initialize a Dictionary in a single statement with correct type checking. This implementation is longer, however it adds additional functionality such as a containsKey(key: string) and remove(key: string) method. I suspect that this could be simplified once generics are available in the 0.9 release.

First we declare the base Dictionary class and Interface. The interface is required for the indexer because classes cannot implement them.

interface IDictionary {
    add(key: string, value: any): void;
    remove(key: string): void;
    containsKey(key: string): bool;
    keys(): string[];
    values(): any[];
}

class Dictionary {

    _keys: string[] = new string[];
    _values: any[] = new any[];

    constructor(init: { key: string; value: any; }[]) {

        for (var x = 0; x < init.length; x++) {
            this[init[x].key] = init[x].value;
            this._keys.push(init[x].key);
            this._values.push(init[x].value);
        }
    }

    add(key: string, value: any) {
        this[key] = value;
        this._keys.push(key);
        this._values.push(value);
    }

    remove(key: string) {
        var index = this._keys.indexOf(key, 0);
        this._keys.splice(index, 1);
        this._values.splice(index, 1);

        delete this[key];
    }

    keys(): string[] {
        return this._keys;
    }

    values(): any[] {
        return this._values;
    }

    containsKey(key: string) {
        if (typeof this[key] === "undefined") {
            return false;
        }

        return true;
    }

    toLookup(): IDictionary {
        return this;
    }
}

Now we declare the Person specific type and Dictionary/Dictionary interface. In the PersonDictionary note how we override values() and toLookup() to return the correct types.

interface IPerson {
    firstName: string;
    lastName: string;
}

interface IPersonDictionary extends IDictionary {
    [index: string]: IPerson;
    values(): IPerson[];
}

class PersonDictionary extends Dictionary {
    constructor(init: { key: string; value: IPerson; }[]) {
        super(init);
    }

    values(): IPerson[]{
        return this._values;
    }

    toLookup(): IPersonDictionary {
        return this;
    }
}

And here is a simple initialization and usage example:

var persons = new PersonDictionary([
    { key: "p1", value: { firstName: "F1", lastName: "L2" } },
    { key: "p2", value: { firstName: "F2", lastName: "L2" } },
    { key: "p3", value: { firstName: "F3", lastName: "L3" } }
]).toLookup();


alert(persons["p1"].firstName + " " + persons["p1"].lastName);
// alert: F1 L2

persons.remove("p2");

if (!persons.containsKey("p2")) {
    alert("Key no longer exists");
    // alert: Key no longer exists
}

alert(persons.keys().join(", "));
// alert: p1, p3

C# importing class into another class doesn't work

using is for namespaces only - if both classes are in the same namespace just drop the using.

You have to reference the assembly created in the first step when you compile the .exe:

csc /t:library /out:MyClass.dll MyClass.cs
csc /reference:MyClass.dll /t:exe /out:MyProgram.exe MyMainClass.cs

You can make things simpler if you just compile the files together:

csc /t:exe /out:MyProgram.exe MyMainClass.cs MyClass.cs

or

csc /t:exe /out:MyProgram.exe *.cs

EDIT: Here's how the files should look like:

MyClass.cs:

namespace MyNamespace {
    public class MyClass {
        void stuff() {

        }
    }
}

MyMainClass.cs:

using System;

namespace MyNamespace {
    public class MyMainClass {
        static void Main() {
            MyClass test = new MyClass();
        }
    }
}

Reverse ip, find domain names on ip address

You can use ping -a <ip> or nbtstat -A <ip>

Why use Gradle instead of Ant or Maven?

It's also much easier to manage native builds. Ant and Maven are effectively Java-only. Some plugins exist for Maven that try to handle some native projects, but they don't do an effective job. Ant tasks can be written that compile native projects, but they are too complex and awkward.

We do Java with JNI and lots of other native bits. Gradle simplified our Ant mess considerably. When we started to introduce dependency management to the native projects it was messy. We got Maven to do it, but the equivalent Gradle code was a tiny fraction of what was needed in Maven, and people could read it and understand it without becoming Maven gurus.

How to send post request to the below post method using postman rest client

  1. Open Postman.
  2. Enter URL in the URL bar http://{server:port}/json/metallica/post.
  3. Click Headers button and enter Content-Type as header and application/json in value.
  4. Select POST from the dropdown next to the URL text box.
  5. Select raw from the buttons available below URL text box.
  6. Select JSON from the following dropdown.
  7. In the textarea available below, post your request object:

    {
     "title" : "test title",
     "singer" : "some singer"
    }
    
  8. Hit Send.

  9. Refer to screenshot below: enter image description here

Change variable name in for loop using R

Another option is using eval and parse, as in

d = 5
for (i in 1:10){
     eval(parse(text = paste('a', 1:10, ' = d + rnorm(3)', sep='')[i]))
}

SQL Plus change current directory

Could you use the SQLPATH environment variable to tell sqlplus where to look for the scripts you are trying to run? I believe you could use HOST to set SQLPATH in the script too.

There could potentially be problems if two scripts have the same name and both directories are in the SQLPATH.

How to fill a datatable with List<T>

I also had to come up with an alternate solution, as none of the options listed here worked in my case. I was using an IEnumerable and the underlying data was a IEnumerable and the properties couldn't be enumerated. This did the trick:

// remove "this" if not on C# 3.0 / .NET 3.5
public static DataTable ConvertToDataTable<T>(this IEnumerable<T> data)
{
    List<IDataRecord> list = data.Cast<IDataRecord>().ToList();

    PropertyDescriptorCollection props = null;
    DataTable table = new DataTable();
    if (list != null && list.Count > 0)
    {
        props = TypeDescriptor.GetProperties(list[0]);
        for (int i = 0; i < props.Count; i++)
        {
            PropertyDescriptor prop = props[i];
            table.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
        }
    }
    if (props != null)
    {
        object[] values = new object[props.Count];
        foreach (T item in data)
        {
            for (int i = 0; i < values.Length; i++)
            {
                values[i] = props[i].GetValue(item) ?? DBNull.Value;
            }
            table.Rows.Add(values);
        }
    }
    return table;
}

What is the preferred Bash shebang?

It really depends on how you write your bash scripts. If your /bin/sh is symlinked to bash, when bash is invoked as sh, some features are unavailable.

If you want bash-specific, non-POSIX features, use #!/bin/bash

Java: convert List<String> to a String

Code you have is right way to do it if you want to do using JDK without any external libraries. There is no simple "one-liner" that you could use in JDK.

If you can use external libs, I recommend that you look into org.apache.commons.lang.StringUtils class in Apache Commons library.

An example of usage:

List<String> list = Arrays.asList("Bill", "Bob", "Steve");
String joinedResult = StringUtils.join(list, " and ");

How Long Does it Take to Learn Java for a Complete Newbie?

I teach Java Programming at a high school, and our course runs 14 weeks. This is enough time to give students a solid foundation in object oriented programming, but students are not experienced enough to develop and large projects or anything too complicated.

Many schools use the textbook by Lambert & Osbborne:

Lambert, K. & Osborne, M. Fundamentals of Java: AP Computer Science Essentials for the AP Exam. 3rd ed. 2006. Thomson Course Technology.

Define constant variables in C++ header

You could simply define a series of const ints in a header file:

// Constants.h
#if !defined(MYLIB_CONSTANTS_H)
#define MYLIB_CONSTANTS_H 1

const int a = 100;
const int b = 0x7f;

#endif

This works because in C++ a name at namespace scope (including the global namespace) that is explicitly declared const and not explicitly declared extern has internal linkage, so these variables would not cause duplicate symbols when you link together translation units. Alternatively you could explicitly declare the constants as static.

static const int a = 100;
static const int b = 0x7f;

This is more compatible with C and more readable for people that may not be familiar with C++ linkage rules.

If all the constants are ints then another method you could use is to declare the identifiers as enums.

enum mylib_constants {
    a = 100;
    b = 0x7f;
};

All of these methods use only a header and allow the declared names to be used as compile time constants. Using extern const int and a separate implementation file prevents the names from being used as compile time constants.


Note that the rule that makes certain constants implicitly internal linkage does apply to pointers, exactly like constants of other types. The tricky thing though is that marking a pointer as const requires syntax a little different that most people use to make variables of other types const. You need to do:

int * const ptr;

to make a constant pointer, so that the rule will apply to it.

Also note that this is one reason I prefer to consistently put const after the type: int const instead of const int. I also put the * next to the variable: i.e. int *ptr; instead of int* ptr; (compare also this discussion).

I like to do these sorts of things because they reflect the general case of how C++ really works. The alternatives (const int, int* p) are just special cased to make some simple things more readable. The problem is that when you step out of those simple cases, the special cased alternatives become actively misleading.

So although the earlier examples show the common usage of const, I would actually recommend people write them like this:

int const a = 100;
int const b = 0x7f;

and

static int const a = 100;
static int const b = 0x7f;

List comprehension vs. lambda + filter

Curiously on Python 3, I see filter performing faster than list comprehensions.

I always thought that the list comprehensions would be more performant. Something like: [name for name in brand_names_db if name is not None] The bytecode generated is a bit better.

>>> def f1(seq):
...     return list(filter(None, seq))
>>> def f2(seq):
...     return [i for i in seq if i is not None]
>>> disassemble(f1.__code__)
2         0 LOAD_GLOBAL              0 (list)
          2 LOAD_GLOBAL              1 (filter)
          4 LOAD_CONST               0 (None)
          6 LOAD_FAST                0 (seq)
          8 CALL_FUNCTION            2
         10 CALL_FUNCTION            1
         12 RETURN_VALUE
>>> disassemble(f2.__code__)
2           0 LOAD_CONST               1 (<code object <listcomp> at 0x10cfcaa50, file "<stdin>", line 2>)
          2 LOAD_CONST               2 ('f2.<locals>.<listcomp>')
          4 MAKE_FUNCTION            0
          6 LOAD_FAST                0 (seq)
          8 GET_ITER
         10 CALL_FUNCTION            1
         12 RETURN_VALUE

But they are actually slower:

   >>> timeit(stmt="f1(range(1000))", setup="from __main__ import f1,f2")
   21.177661532000116
   >>> timeit(stmt="f2(range(1000))", setup="from __main__ import f1,f2")
   42.233950221000214

Printing 2D array in matrix format

I wrote extension method

public static string ToMatrixString<T>(this T[,] matrix, string delimiter = "\t")
{
    var s = new StringBuilder();

    for (var i = 0; i < matrix.GetLength(0); i++)
    {
        for (var j = 0; j < matrix.GetLength(1); j++)
        {
            s.Append(matrix[i, j]).Append(delimiter);
        }

        s.AppendLine();
    }

    return s.ToString();
}

To use just call the method

results.ToMatrixString();

What is the significance of 1/1/1753 in SQL Server?

Incidentally, Windows no longer knows how to correctly convert UTC to U.S. local time for certain dates in March/April or October/November of past years. UTC-based timestamps from those dates are now somewhat nonsensical. It would be very icky for the OS to simply refuse to handle any timestamps prior to the U.S. government's latest set of DST rules, so it simply handles some of them wrong. SQL Server refuses to process dates before 1753 because lots of extra special logic would be required to handle them correctly and it doesn't want to handle them wrong.

How can I get double quotes into a string literal?

Thankfully, with C++11 there is also the more pleasing approach of using raw string literals.

printf("She said \"time flies like an arrow, but fruit flies like a banana\".");

Becomes:

printf(R"(She said "time flies like an arrow, but fruit flies like a banana".)");

With respect to the addition of brackets after the opening quote, and before the closing quote, note that they can be almost any combination of up to 16 characters, helping avoid the situation where the combination is present in the string itself. Specifically:

any member of the basic source character set except: space, the left parenthesis (, the right parenthesis ), the backslash , and the control characters representing horizontal tab, vertical tab, form feed, and newline" (N3936 §2.14.5 [lex.string] grammar) and "at most 16 characters" (§2.14.5/2)

How much clearer it makes this short strings might be debatable, but when used on longer formatted strings like HTML or JSON, it's unquestionably far clearer.

How to get just the responsive grid from Bootstrap 3?

Go to http://getbootstrap.com/customize/ and toggle just what you want from the BS3 framework and then click "Compile and Download" and you'll get the CSS and JS that you chose.

Bootstrap Customizer

Open up the CSS and remove all but the grid. They include some normalize stuff too. And you'll need to adjust all the styles on your site to box-sizing: border-box - http://www.w3schools.com/cssref/css3_pr_box-sizing.asp

ESLint - "window" is not defined. How to allow global variables in package.json

Your .eslintrc.json should contain the text below.
This way ESLint knows about your global variables.

{
  "env": {
    "browser": true,
    "node": true
  }                                                                      
}

How can I include css files using node, express, and ejs?

Its simple if you are using express.static(__dirname + 'public') then don't forget to put a forward slash before public that is express.static(__dirname + '/public') or use express.static('public') its also going to work; and don't change anything in CSS linking.

if variable contains

if (code.indexOf("ST1")>=0) { location = "stoke central"; }

Read file from line 2 or skip header row

If slicing could work on iterators...

from itertools import islice
with open(fname) as f:
    for line in islice(f, 1, None):
        pass

Difference between request.getSession() and request.getSession(true)

request.getSession() or request.getSession(true) both will return a current session only . if current session will not exist then it will create a new session.

jQuery CSS Opacity

jQuery('#main').css('opacity') = '0.6';

should be

jQuery('#main').css('opacity', '0.6');

Update:

http://jsfiddle.net/GegMk/ if you type in the text box. Click away, the opacity changes.

What's the difference between display:inline-flex and display:flex?

Using two-value display syntax instead, for clarity

The display CSS property in fact sets two things at once: the outer display type, and the inner display type. The outer display type affects how the element (which acts as a container) is displayed in its context. The inner display type affects how the children of the element (or the children of the container) are laid out.

If you use the two-value display syntax, which is only supported in some browsers like Firefox, the difference between the two is much more obvious:

  • display: block is equivalent to display: block flow
  • display: inline is equivalent to display: inline flow
  • display: flex is equivalent to display: block flex
  • display: inline-flex is equivalent to display: inline flex
  • display: grid is equivalent to display: block grid
  • display: inline-grid is equivalent to display: inline grid

Outer display type: block or inline:

An element with the outer display type of block will take up the whole width available to it, like <div> does. An element with the outer display type of inline will only take up the width that it needs, with wrapping, like <span> does.

Inner display type: flow, flex or grid:

The inner display type flow is the default inner display type when flex or grid is not specified. It is the way of laying out children elements that we are used to in a <p> for instance. flex and grid are new ways of laying out children that each deserve their own post.

Conclusion:

The difference between display: flex and display: inline-flex is the outer display type, the first's outer display type is block, and the second's outer display type is inline. Both of them have the inner display type of flex.

References:

How do I point Crystal Reports at a new database

Use the Database menu and "Set Datasource Location" menu option to change the name or location of each table in a report.

This works for changing the location of a database, changing to a new database, and changing the location or name of an individual table being used in your report.

To change the datasource connection, go the Database menu and click Set Datasource Location.

  1. Change the Datasource Connection:
    1. From the Current Data Source list (the top box), click once on the datasource connection that you want to change.
    2. In the Replace with list (the bottom box), click once on the new datasource connection.
    3. Click Update.
  2. Change Individual Tables:
    1. From the Current Data Source list (the top box), expand the datasource connection that you want to change.
    2. Find the table for which you want to update the location or name.
    3. In the Replace with list (the bottom box), expand the new datasource connection.
    4. Find the new table you want to update to point to.
    5. Click Update.
    6. Note that if the table name has changed, the old table name will still appear in the Field Explorer even though it is now using the new table. (You can confirm this be looking at the Table Name of the table's properties in Current Data Source in Set Datasource Location. Screenshot http://i.imgur.com/gzGYVTZ.png) It's possible to rename the old table name to the new name from the context menu in Database Expert -> Selected Tables.
  3. Change Subreports:
    1. Repeat each of the above steps for any subreports you might have embedded in your report.
    2. Close the Set Datasource Location window.
  4. Any Commands or SQL Expressions:
    1. Go to the Database menu and click Database Expert.
    2. If the report designer used "Add Command" to write custom SQL it will be shown in the Selected Tables box on the right.
    3. Right click that command and choose "Edit Command".
    4. Check if that SQL is specifying a specific database. If so you might need to change it.
    5. Close the Database Expert window.
    6. In the Field Explorer pane on the right, right click any SQL Expressions.
    7. Check if the SQL Expressions are specifying a specific database. If so you might need to change it also.
    8. Save and close your Formula Editor window when you're done editing.

And try running the report again.

The key is to change the datasource connection first, then any tables you need to update, then the other stuff. The connection won't automatically change the tables underneath. Those tables are like goslings that've imprinted on the first large goose-like animal they see. They'll continue to bypass all reason and logic and go to where they've always gone unless you specifically manually change them.

To make it more convenient, here's a tip: You can "Show SQL Query" in the Database menu, and you'll see table names qualified with the database (like "Sales"."dbo"."Customers") for any tables that go straight to a specific database. That might make the hunting easier if you have a lot of stuff going on. When I tackled this problem I had to change each and every table to point to the new table in the new database.