Check if list is empty in C#

If you're using a gridview then use the empty data template: http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.emptydatatemplate.aspx

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        runat="server">

        <emptydatarowstyle backcolor="LightBlue"
          forecolor="Red"/>

        <emptydatatemplate>

          <asp:image id="NoDataImage"
            imageurl="~/images/Image.jpg"
            alternatetext="No Image" 
            runat="server"/>

            No Data Found.  

        </emptydatatemplate> 

      </asp:gridview>

What is managed or unmanaged code in programming?

Managed code is what C#.Net, VB.Net, F#.Net etc compilers create. It runs on the CLR, which among other things offers services like garbage collection, and reference checking, and much more. So think of it as, my code is managed by the CLR.

On the other hand, unmanaged code compiles straight to machine code. It doesn't manage by CLR.

How to break out from a ruby block?

To break out from a ruby block simply use return keyword return if value.nil?

Common sources of unterminated string literal

Look for a string which contains an unescaped single qoute that may be inserted by some server side code.

BeanFactory not initialized or already closed - call 'refresh' before

In my case, this error was due to the Network connection error that i was noticed in log.

How to trigger SIGUSR1 and SIGUSR2?

They are signals that application developers use. The kernel shouldn't ever send these to a process. You can send them using kill(2) or using the utility kill(1).

If you intend to use signals for synchronization you might want to check real-time signals (there's more of them, they are queued, their delivery order is guaranteed etc).

Combining COUNT IF AND VLOOK UP EXCEL

You can combine this all into one formula, but you need to use a regular IF first to find out if the VLOOKUP came back with something, then use your COUNTIF if it did.

=IF(ISERROR(VLOOKUP(B1,Sheet2!A1:A9,1,FALSE)),"Not there",COUNTIF(Sheet2!A1:A9,B1))

In this case, Sheet2-A1:A9 is the range I was searching, and Sheet1-B1 had the value I was looking for ("To retire" in your case).

How to send POST request?

Your data dictionary conteines names of form input fields, you just keep on right their values to find results. form view Header configures browser to retrieve type of data you declare. With requests library it's easy to send POST:

import requests

url = "https://bugs.python.org"
data = {'@number': 12524, '@type': 'issue', '@action': 'show'}
headers = {"Content-type": "application/x-www-form-urlencoded", "Accept":"text/plain"}
response = requests.post(url, data=data, headers=headers)

print(response.text)

More about Request object: https://requests.readthedocs.io/en/master/api/

MongoDB: update every document on one field

This code will be helpful for you

        Model.update({
            'type': "newuser"
        }, {
            $set: {
                email: "[email protected]",
                phoneNumber:"0123456789"
            }
        }, {
            multi: true
        },
        function(err, result) {
            console.log(result);
            console.log(err);
        })

Why can't Python find shared objects that are in directories in sys.path?

For me what works here is to using a version manager such as pyenv, which I strongly recommend to get your project environments and package versions well managed and separate from that of the operative system.

I had this same error after an OS update, but was easily fixed with pyenv install 3.7-dev (the version I use).

Get jQuery version from inspecting the jQuery object

$()['jquery']

Invoke console.log($()) and take note about jquery object fields :

jquery
selector
prevObject

enter image description here

How to read values from the querystring with ASP.NET Core?

You can just create an object like this:

public class SomeQuery
{
    public string SomeParameter { get; set; }
    public int? SomeParameter2 { get; set; }
}

And then in controller just make something like that:

[HttpGet]
public IActionResult FindSomething([FromQuery] SomeQuery query)
{
    // Your implementation goes here..
}

Even better, you can create API model from:

[HttpGet]
public IActionResult GetSomething([FromRoute] int someId, [FromQuery] SomeQuery query)

to:

[HttpGet]
public IActionResult GetSomething(ApiModel model)

public class ApiModel
{
    [FromRoute]
    public int SomeId { get; set; }
    [FromQuery]
    public string SomeParameter { get; set; }
    [FromQuery]
    public int? SomeParameter2 { get; set; }
}

The import org.junit cannot be resolved

Right-click on the eclipse project and navigate:

Properties -> Java Build Path -> Libraries -> Add Library -> JUnit -> Junit 3/4

It works on mine.

Batch File: ( was unexpected at this time

You are getting that error because when the param1 if statements are evaluated, param is always null due to being scoped variables without delayed expansion.

When parentheses are used, all the commands and variables within those parentheses are expanded. And at that time, param1 has no value making the if statements invalid. When using delayed expansion, the variables are only expanded when the command is actually called.

Also I recommend using if not defined command to determine if a variable is set.

@echo off
setlocal EnableExtensions EnableDelayedExpansion
cls
title ~USB Wizard~
echo What do you want to do?
echo 1.Enable/Disable USB Storage Devices.
echo 2.Enable/Disable Writing Data onto USB Storage.
echo 3.~Yet to come~.

set "a=%globalparam1%"
goto :aCheck
:aPrompt
set /p "a=Enter Choice: "
:aCheck
if not defined a goto :aPrompt
echo %a%

IF "%a%"=="2" (
    title USB WRITE LOCK
    echo What do you want to do?
    echo 1.Apply USB Write Protection
    echo 2.Remove USB Write Protection

    ::param1
    set "param1=%globalparam2%"
    goto :param1Check
    :param1Prompt
    set /p "param1=Enter Choice: "
    :param1Check
    if not defined param1 goto :param1Prompt
    echo !param1!

    if "!param1!"=="1" (
        REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000001 
        echo USB Write is Locked!
    )
    if "!param1!"=="2" (
        REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000000
        echo USB Write is Unlocked! 
    )
)
pause
endlocal

Formatting "yesterday's" date in python

Could I just make this somewhat more international and format the date according to the international standard and not in the weird month-day-year, that is common in the US?

from datetime import datetime, timedelta

yesterday = datetime.now() - timedelta(days=1)
yesterday.strftime('%Y-%m-%d')

What characters are valid in a URL?

All the gory details can be found in the current RFC on the topic: RFC 3986 (Uniform Resource Identifier (URI): Generic Syntax)

Based on this related answer, you are looking at a list that looks like: A-Z, a-z, 0-9, -, ., _, ~, :, /, ?, #, [, ], @, !, $, &, ', (, ), *, +, ,, ;, %, and =. Everything else must be url-encoded. Also, some of these characters can only exist in very specific spots in a URI and outside of those spots must be url-encoded (e.g. % can only be used in conjunction with url encoding as in %20), the RFC has all of these specifics.

Make index.html default, but allow index.php to be visited if typed in

DirectoryIndex index.html index.htm default.htm index.php index.php3 index.phtml index.php5 index.shtml mwindex.phtml

it doesn't has any means? you may be just need to add like this!

<IfModule dir_module>
    DirectoryIndex index.php index.html index.htm
</IfModule>

Get parent directory of running script

Got it myself, it's a bit kludgy but it works:

substr(dirname($_SERVER['SCRIPT_NAME']), 0, strrpos(dirname($_SERVER['SCRIPT_NAME']), '/') + 1)

So if I have /path/to/folder/index.php, this results in /path/to/.

How to schedule a periodic task in Java?

Have you tried Spring Scheduler using annotations ?

@Scheduled(cron = "0 0 0/8 ? * * *")
public void scheduledMethodNoReturnValue(){
    //body can be another method call which returns some value.
}

you can do this with xml as well.

 <task:scheduled-tasks>
   <task:scheduled ref = "reference" method = "methodName" cron = "<cron expression here> -or- ${<cron expression from property files>}"
 <task:scheduled-tasks>

Programmatically set the initial view controller using Storyboards

Found simple solution - no need to remove "initial view controller check" from storyboard and editing project Info tab and use makeKeyAndVisible, just place

self.window.rootViewController = rootVC;

- (BOOL) application:didFinishLaunchingWithOptions:

Dynamically add event listener

Here's my workaround:

I created a library with Angular 6. I added a common component commonlib-header which is used like this in an external application.

Note the serviceReference which is the class (injected in the component constructor(public serviceReference: MyService) that uses the commonlib-header) that holds the stringFunctionName method:

<commonlib-header
    [logo]="{ src: 'assets/img/logo.svg', alt: 'Logo', href: '#' }"
    [buttons]="[{ index: 0, innerHtml: 'Button', class: 'btn btn-primary', onClick: [serviceReference, 'stringFunctionName', ['arg1','arg2','arg3']] }]">
    </common-header>

The library component is programmed like this. The dynamic event is added in the onClick(fn: any) method:

export class HeaderComponent implements OnInit {

 _buttons: Array<NavItem> = []

 @Input()
  set buttons(buttons: Array<any>) {
    buttons.forEach(navItem => {
      let _navItem = new NavItem(navItem.href, navItem.innerHtml)

      _navItem.class = navItem.class

      _navItem.onClick = navItem.onClick // this is the array from the component @Input properties above

      this._buttons[navItem.index] = _navItem
    })
  }

  constructor() {}

  ngOnInit() {}

  onClick(fn: any){
    let ref = fn[0]
    let fnName = fn[1]
    let args = fn[2]

    ref[fnName].apply(ref, args)
  }

The reusable header.component.html:

<div class="topbar-right">
  <button *ngFor="let btn of _buttons"
    class="{{ btn.class }}"
    (click)="onClick(btn.onClick)"
    [innerHTML]="btn.innerHtml | keepHtml"></button>
</div>

Check if a string contains a string in C++

Starting from C++23 you can use std::string::contains

#include <string>

const auto haystack = std::string("haystack with needles");
const auto needle = std::string("needle");

if (haystack.contains(needle))
{
    // found!
}

How to get next/previous record in MySQL?

I think to have the real next or previous row in SQL table we need the real value with equal, (< or >) return more than one if you need to change position of row in a ordering table.

we need the value $position to search the neighbours row In my table I created a column 'position'

and SQL query for getting the needed row is :

for next :

SELECT * 
FROM `my_table` 
WHERE id = (SELECT (id) 
            FROM my_table 
            WHERE position = ($position+1)) 
LIMIT 1

for previous:

 SELECT * 
 FROM my_table 
 WHERE id = (SELECT (id) 
             FROM my_table 
             WHERE `position` = ($position-1)) 
 LIMIT 1

How can I create a Windows .exe (standalone executable) using Java/Eclipse?

Typical Java programs compile into .jar files, which can be executed like .exe files provided the target machine has Java installed and that Java is in its PATH. From Eclipse you use the Export menu item from the File menu.

callback to handle completion of pipe

Based nodejs document, http://nodejs.org/api/stream.html#stream_event_finish, it should handle writableStream's finish event.

var writable = getWriteable();
var readable = getReadable();
readable.pipe(writable);
writable.on('finish', function(){ ... });

How do I store the select column in a variable?

Assuming such a query would return a single row, you could use either

select @EmpId = Id from dbo.Employee

set @EmpId = (select Id from dbo.Employee)

How can I display an image from a file in Jupyter Notebook?

Another option for plotting inline from an array of images could be:

import IPython
def showimg(a):
    IPython.display.display(PIL.Image.fromarray(a))

where a is an array

a.shape
(720, 1280, 3)

Bubble Sort Homework

I am a fresh fresh beginner, started to read about Python yesterday. Inspired by your example I created something maybe more in the 80-ties style, but nevertheless it kinda works

lista1 = [12, 5, 13, 8, 9, 65]

i=0
while i < len(lista1)-1:
    if lista1[i] > lista1[i+1]:
        x = lista1[i]
        lista1[i] = lista1[i+1]
        lista1[i+1] = x
        i=0
        continue
    else:
        i+=1

print(lista1)

css rotate a pseudo :after or :before content:""

.process-list:after{
    content: "\2191";
    position: absolute;
    top:50%;
    right:-8px;
    background-color: #ea1f41;
    width:35px;
    height: 35px;
    border:2px solid #ffffff;
    border-radius: 5px;
    color: #ffffff;
    z-index: 10000;
    -webkit-transform: rotate(50deg) translateY(-50%);
    -moz-transform: rotate(50deg) translateY(-50%);
    -ms-transform: rotate(50deg) translateY(-50%);
    -o-transform: rotate(50deg) translateY(-50%);
    transform: rotate(50deg) translateY(-50%);
}

you can check this code . i hope you will easily understand.

Enable/disable buttons with Angular

Set a property for the current lesson: currentLesson. It will hold, obviously, the 'number' of the choosen lesson. On each button click, set the currentLesson value to 'number'/ order of the button, i.e. for the first button, it will be '1', for the second '2' and so on. Each button now can be disabled with [disabled] attribute, if it the currentLesson is not the same as it's order.

HTML

  <button  (click)="currentLesson = '1'"
         [disabled]="currentLesson !== '1'" class="primair">
           Start lesson</button>
  <button (click)="currentLesson = '2'"
         [disabled]="currentLesson !== '2'" class="primair">
           Start lesson</button>
 .....//so on

Typescript

currentLesson:string;

  classes = [
{
  name: 'string',
  level: 'string',
  code: 'number',
  currentLesson: '1'
}]

constructor(){
  this.currentLesson=this.classes[0].currentLesson
}

DEMO

Putting everything in a loop:

HTML

<div *ngFor="let class of classes; let i = index">
   <button [disabled]="currentLesson !== i + 1" class="primair">
           Start lesson {{i +  1}}</button>
</div>

Typescript

currentLesson:string;

classes = [
{
  name: 'Lesson1',
  level: 1,
  code: 1,
},{
  name: 'Lesson2',
  level: 1,
  code: 2,
},
{
  name: 'Lesson3',
  level: 2,
  code: 3,
}]

DEMO

How do you deploy Angular apps?

Simple answer. Use the Angular CLI and issue the

ng build

command in the root directory of your project. The site will be created in the dist directory and you can deploy that to any web server.

This will build for test, if you have production settings in your app you should use

ng build --prod

This will build the project in the dist directory and this can be pushed to the server.

Much has happened since I first posted this answer. The CLI is finally at a 1.0.0 so following this guide go upgrade your project should happen before you try to build. https://github.com/angular/angular-cli/wiki/stories-rc-update

How can I sort a std::map first by value, then by key?

You can use std::set instead of std::map.

You can store both key and value in std::pair and the type of container will look like this:

std::set< std::pair<int, std::string> > items;

std::set will sort it's values both by original keys and values that were stored in std::map.

How to use "Share image using" sharing Intent to share images in android?

Simple and Easiest code you can use it to share image from gallery.

 String image_path;
            File file = new File(image_path);
            Uri uri = Uri.fromFile(file);
            Intent intent = new Intent(Intent.ACTION_SEND);
            intent .setType("image/*");
            intent .putExtra(Intent.EXTRA_STREAM, uri);
            context.startActivity(intent );

java.lang.UnsatisfiedLinkError no *****.dll in java.library.path

I'm using Mac OS X Yosemite and Netbeans 8.02, I got the same error and the simple solution I have found is like above, this is useful when you need to include native library in the project. So do the next for Netbeans:

1.- Right click on the Project
2.- Properties
3.- Click on RUN
4.- VM Options: java -Djava.library.path="your_path"
5.- for example in my case: java -Djava.library.path=</Users/Lexynux/NetBeansProjects/NAO/libs>
6.- Ok

I hope it could be useful for someone. The link where I found the solution is here: java.library.path – What is it and how to use

foreach with index

The C# foreach doesn't have a built in index. You'll need to add an integer outside the foreach loop and increment it each time.

int i = -1;
foreach (Widget w in widgets)
{
   i++;
   // do something
}

Alternatively, you could use a standard for loop as follows:

for (int i = 0; i < widgets.Length; i++)
{
   w = widgets[i];
   // do something
}

Detect if device is iOS

In my case the user agent was not good enought since in the Ipad the user agent was the same as in Mac OS, therefore I had to do a nasty trick:

var mql = window.matchMedia("(orientation: landscape)");

/**
 * If we are in landscape but the height is bigger than width
 */
if(mql.matches && window.screen.height > window.screen.width) {
    // IOS
} else {
    // Mac OS
}

How to export collection to CSV in MongoDB?

Below command used to export collection to CSV format.

Note: naag is database, employee1_json is a collection.

mongoexport --db naag--collection employee1_json --type csv --out /home/orienit/work/mongodb/employee1_csv_op1

How to clear https proxy setting of NPM?

npm config delete proxy -g

worked for me.

-g was important as initially it was set with that option. You can check configurations set with :

npm config list

Can you set a border opacity in CSS?

As an alternate solution that may work in some cases: change the border-style to dotted.

Having alternating groups of pixels between the foreground color and the background color isn't the same as a continuous line of partially transparent pixels. On the other hand, this requires significantly less CSS and it is much more compatible across every browser without any browser-specific directives.

Call web service in excel

Yes You Can!

I worked on a project that did that (see comment). Unfortunately no code samples from that one, but googling revealed these:

How you can integrate data from several Web services using Excel and VBA

STEP BY STEP: Consuming Web Services through VBA (Excel or Word)

VBA: Consume Soap Web Services

Get startup type of Windows service using PowerShell

In PowerShell you can use the command Set-Service:

Set-Service -Name Winmgmt -StartupType Manual

I haven't found a PowerShell command to view the startup type though. One would assume that the command Get-Service would provide that, but it doesn't seem to.

how to make window.open pop up Modal?

You can't make window.open modal and I strongly recommend you not to go that way. Instead you can use something like jQuery UI's dialog widget.

UPDATE:

You can use load() method:

$("#dialog").load("resource.php").dialog({options});

This way it would be faster but the markup will merge into your main document so any submit will be applied on the main window.

And you can use an IFRAME:

$("#dialog").append($("<iframe></iframe>").attr("src", "resource.php")).dialog({options});

This is slower, but will submit independently.

Connect to docker container as user other than root

This solved my use case that is: "Compile webpack stuff in nodejs container on Windows running Docker Desktop with WSL2 and have the built assets under your currently logged in user."

docker run -u 1000 -v "$PWD":/build -w /build node:10.23 /bin/sh -c 'npm install && npm run build'

Based on the answer by eigenfield. Thank you!

Also this material helped me understand what is going on.

Laravel 5 not finding css files

<link rel="stylesheet" href="/css/bootstrap.min.css">if you are using laravel 5 or 6 you should create folder css and call it with

it works for me

Changing iframe src with Javascript

Maybe this can be helpful... It's plain html - no javascript:

_x000D_

<p>Click on link bellow to change iframe content:</p>_x000D_
<a href="http://www.bing.com" target="search_iframe">Bing</a> -_x000D_
<a href="http://en.wikipedia.org" target="search_iframe">Wikipedia</a> -_x000D_
<a href="http://google.com" target="search_iframe">Google</a> (not allowed in inframe)_x000D_
_x000D_
<iframe src="http://en.wikipedia.org" width="100%" height="100%" name="search_iframe"></iframe>

_x000D_

By the way some sites do not allow you to open them in iframe (security reasons - clickjacking)

How to create a pivot query in sql server without aggregate function

SELECT *
FROM
(
SELECT [Period], [Account], [Value]
FROM TableName
) AS source
PIVOT
(
    MAX([Value])
    FOR [Period] IN ([2000], [2001], [2002])
) as pvt

Another way,

SELECT ACCOUNT,
      MAX(CASE WHEN Period = '2000' THEN Value ELSE NULL END) [2000],
      MAX(CASE WHEN Period = '2001' THEN Value ELSE NULL END) [2001],
      MAX(CASE WHEN Period = '2002' THEN Value ELSE NULL END) [2002]
FROM tableName
GROUP BY Account

SQLFiddle Demo (both queries)

Correct way to detach from a container without stopping it

I consider Ashwin's answer to be the most correct, my old answer is below.

I'd like to add another option here which is to run the container as follows

docker run -dti foo bash

You can then enter the container and run bash with

docker exec -ti ID_of_foo bash

No need to install sshd :)

Convert a Pandas DataFrame to a dictionary

Should a dictionary like:

{'red': '0.500', 'yellow': '0.250, 'blue': '0.125'}

be required out of a dataframe like:

        a      b
0     red  0.500
1  yellow  0.250
2    blue  0.125

simplest way would be to do:

dict(df.values)

working snippet below:

import pandas as pd
df = pd.DataFrame({'a': ['red', 'yellow', 'blue'], 'b': [0.5, 0.25, 0.125]})
dict(df.values)

Delete default value of an input text on click

Enter the following inside the tag, just add onFocus="value=''" so that your final code looks like this:

<input type="email" id="Email" onFocus="value=''">

This makes use of the javascript onFocus() event holder.

How to use MapView in android using google map V2?

More complete sample from here and here.

Or you can check out my layout sample. p.s no need to put API key in the map view.

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

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

    <com.google.android.gms.maps.MapView
            android:id="@+id/map_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="2"
            />

    <ListView android:id="@+id/nearby_lv"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="@color/white"
              android:layout_weight="1"
            />

</LinearLayout>

HTTP Status 405 - Request method 'POST' not supported (Spring MVC)

Check if you are returning a @ResponseBody or a @ResponseStatus

I had a similar problem. My Controller looked like that:

@RequestMapping(value="/user", method = RequestMethod.POST)
public String updateUser(@RequestBody User user){
    return userService.updateUser(user).getId();
}

When calling with a POST request I always got the following error:

HTTP Status 405 - Request method 'POST' not supported

After a while I figured out that the method was actually called, but because there is no @ResponseBody and no @ResponseStatus Spring MVC raises the error.

To fix this simply add a @ResponseBody

@RequestMapping(value="/user", method = RequestMethod.POST)
public @ResponseBody String updateUser(@RequestBody User user){
    return userService.updateUser(user).getId();
}

or a @ResponseStatus to your method.

@RequestMapping(value="/user", method = RequestMethod.POST)
@ResponseStatus(value=HttpStatus.OK)
public String updateUser(@RequestBody User user){
    return userService.updateUser(user).getId();
}

Share data between AngularJS controllers

Just do it simple (tested with v1.3.15):

<article ng-controller="ctrl1 as c1">
    <label>Change name here:</label>
    <input ng-model="c1.sData.name" />
    <h1>Control 1: {{c1.sData.name}}, {{c1.sData.age}}</h1>
</article>
<article ng-controller="ctrl2 as c2">
    <label>Change age here:</label>
    <input ng-model="c2.sData.age" />
    <h1>Control 2: {{c2.sData.name}}, {{c2.sData.age}}</h1>
</article>

<script>
    var app = angular.module("MyApp", []);

    var dummy = {name: "Joe", age: 25};

    app.controller("ctrl1", function () {
        this.sData = dummy;
    });

    app.controller("ctrl2", function () {
        this.sData = dummy;
    });
</script>

javascript password generator

A simple lodash solution that warranties 14 alpha, 3 numeric and 3 special characters, not repeated:

const generateStrongPassword = (alpha = 14, numbers = 3, special = 3) => {
  const alphaChars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
  const numberChars = '0123456789';
  const specialChars = '!"£$%^&*()-=+_?';
  const pickedChars = _.sampleSize(alphaChars, alpha)
    .concat(_.sampleSize(numberChars, numbers))
    .concat(_.sampleSize(specialChars, special));
  return _.shuffle(pickedChars).join('');
}

const myPassword = generateStrongPassword();

SQL Add foreign key to existing column

In the future.

ALTER TABLE Employees
ADD UserID int;

ALTER TABLE Employees
ADD CONSTRAINT FK_ActiveDirectories_UserID FOREIGN KEY (UserID)
    REFERENCES ActiveDirectories(id);

JavaScript Array Push key value

You have to use bracket notation:

var obj = {};
obj[a[i]] = 0;
x.push(obj);

The result will be:

x = [{left: 0}, {top: 0}];

Maybe instead of an array of objects, you just want one object with two properties:

var x = {};

and

x[a[i]] = 0;

This will result in x = {left: 0, top: 0}.

How should I choose an authentication library for CodeIgniter?

I use a customized version of DX Auth. I found it simple to use, extremely easy to modify and it has a user guide (with great examples) that is very similar to Code Igniter's.

Check if Cookie Exists

Sorry, not enough rep to add a comment, but from zmbq's answer:

Anyway, to see if a cookie exists, you can check Cookies.Get(string), this will not modify the cookie collection.

is maybe not fully correct, as Cookies.Get(string) will actually create a cookie with that name, if it does not already exist. However, as he said, you need to be looking at Request.Cookies, not Response.Cookies So, something like:

bool cookieExists = HttpContext.Current.Request.Cookies["cookie_name"] != null;

How can I view an old version of a file with Git?

You can also specify a commit hash (often also called commit ID) with the git show command.

In a nutshell

git show <commitHash>:/path/to/file

Step by step

Show the log of all the changes for a given file with git log /path/to/file
In the list of changes shown, it shows the commit hash such as commit 06c98... (06c98... being the commit hash)
Copy the commit hash
Run the command git show <commitHash>:/path/to/file using the commit hashof step 3 & the path/to/file of step 1.

Note: adding the ./ when specifying a relative path seems important, i.e. git show b2f8be577166577c59b55e11cfff1404baf63a84:./flight-simulation/src/main/components/nav-horiz.html.

Encode URL in JavaScript?

You should not use encodeURIComponent() directly.

Take a look at RFC3986: Uniform Resource Identifier (URI): Generic Syntax

sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="

The purpose of reserved characters is to provide a set of delimiting characters that are distinguishable from other data within a URI.

These reserved characters from the URI definition in RFC3986 ARE NOT escaped by encodeURIComponent().

MDN Web Docs: encodeURIComponent()

To be more stringent in adhering to RFC 3986 (which reserves !, ', (, ), and *), even though these characters have no formalized URI delimiting uses, the following can be safely used:

Use the MDN Web Docs function...

function fixedEncodeURIComponent(str) {
  return encodeURIComponent(str).replace(/[!'()*]/g, function(c) {
    return '%' + c.charCodeAt(0).toString(16);
  });
}

html "data-" attribute as javascript parameter

If you are using jQuery you can easily fetch the data attributes by

$(this).data("id") or $(event.target).data("id")

Fitting a Normal distribution to 1D data

Here you are not fitting a normal distribution. Replacing sns.distplot(data) by sns.distplot(data, fit=norm, kde=False) should do the trick.

git rm - fatal: pathspec did not match any files

I had a duplicate directory (~web/web) and it removed the nested duplicate when I ran rm -rf web while inside the first web folder.

what is the use of "response.setContentType("text/html")" in servlet

It is one of the MIME type, in this case you are reponse header MIME type to text/html it means it displays html type. It is a information to browser. There are other types you can set to display excel, zip etc. Please see MIME Type for more information

successful/fail message pop up box after submit?

Instead of using a submit button, try using a <button type="button">Submit</button>

You can then call a javascript function in the button, and after the alert popup is confirmed, you can manually submit the form with document.getElementById("form").submit(); ... so you'll need to name and id your form for that to work.

Excel VBA - Delete empty rows

How about

sub foo()
  dim r As Range, rows As Long, i As Long
  Set r = ActiveSheet.Range("A1:Z50")
  rows = r.rows.Count
  For i = rows To 1 Step (-1)
    If WorksheetFunction.CountA(r.rows(i)) = 0 Then r.rows(i).Delete
  Next
End Sub

Try this

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Range("A" & i & ":" & "Z" & i)
            Else
                Set DelRange = Union(DelRange, Range("A" & i & ":" & "Z" & i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

IF you want to delete the entire row then use this code

Option Explicit

Sub Sample()
    Dim i As Long
    Dim DelRange As Range

    On Error GoTo Whoa

    Application.ScreenUpdating = False

    For i = 1 To 50
        If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
            If DelRange Is Nothing Then
                Set DelRange = Rows(i)
            Else
                Set DelRange = Union(DelRange, Rows(i))
            End If
        End If
    Next i

    If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
    Application.ScreenUpdating = True

    Exit Sub
Whoa:
    MsgBox Err.Description
    Resume LetsContinue
End Sub

What is the exact location of MySQL database tables in XAMPP folder?

Your database is in this directory:
C:\xampp\mysql\data

In Python, how do you convert seconds since epoch to a `datetime` object?

Note that datetime.datetime.fromtimestamp(timestamp) and .utcfromtimestamp(timestamp) fail on windows for dates before Jan. 1, 1970 while negative unix timestamps seem to work on unix-based platforms. The docs say this:

"This may raise ValueError, if the timestamp is out of the range of values supported by the platform C gmtime() function. It’s common for this to be restricted to years in 1970 through 2038"

How to run Ruby code from terminal?

You can run ruby commands in one line with the -e flag:

ruby -e "puts 'hi'"

Check the man page for more information.

Single Result from Database by using mySQLi

Use mysqli_fetch_row(). Try this,

$query = "SELECT ssfullname, ssemail FROM userss WHERE user_id = ".$user_id;
$result = mysqli_query($conn, $query);
$row   = mysqli_fetch_row($result);

$ssfullname = $row['ssfullname'];
$ssemail    = $row['ssemail'];

Webpack - webpack-dev-server: command not found

FYI, to access any script via command-line like you were trying, you need to have the script registered as a shell-script (or any kind of script like .js, .rb) in the system like these files in the the dir /usr/bin in UNIX. And, system must know where to find them. i.e. the location must be loaded in $PATH array.

In your case, the script webpack-dev-server is already installed somewhere inside ./node_modules directory, but system does not know how to access it. So, to access the command webpack-dev-server, you need to install the script in global scope as well.

$ npm install webpack-dev-server -g

Here, -g refers to global scope.

However, this is not recommended way because you might face version conflicting issues; so, instead you can set a command in npm's package.json file like:

  "scripts": {
    "start": "webpack-dev-server -d --config webpack.dev.config.js --content-base public/ --progress --colors"
   }

This setting will let you access the script you want with simple command

$ npm start

So short to memorize and play. And, npm knows the location of the module webpack-dev-server.

To prevent a memory leak, the JDBC Driver has been forcibly unregistered

I found the same issue with Tomcat version 6.026.

I used the Mysql JDBC.jar in WebAPP Library as well as in TOMCAT Lib.

To fix the above by removing the Jar from the TOMCAT lib folder.

So what I understand is that TOMCAT is handling the JDBC memory leak properly. But if the MYSQL Jdbc jar is duplicated in WebApp and Tomcat Lib, Tomcat will only be able to handle the jar present in the Tomcat Lib folder.

How to set the title text color of UIButton?

func setTitleColor(_ color: UIColor?, 
               for state: UIControl.State)

Parameters:

color:
The color of the title to use for the specified state.

state:
The state that uses the specified color. The possible values are described in UIControl.State.

Sample:

let MyButton = UIButton()
MyButton.setTitle("Click Me..!", for: .normal)
MyButton.setTitleColor(.green, for: .normal)

accepting HTTPS connections with self-signed certificates

Maybe this will helpful... it works on java clients using self-signed certificates (there is no check of the certificate). Be careful and use it only for development cases because that is no secure at all!!

How to ignore SSL certificate errors in Apache HttpClient 4.0

Hope it will works on Android just adding HttpClient library... good luck!!

Using WGET to run a cronjob PHP

I tried following format, working fine

*/5 * * * * wget --quiet -O /dev/null http://localhost/cron.php

Why use sys.path.append(path) instead of sys.path.insert(1, path)?

If you really need to use sys.path.insert, consider leaving sys.path[0] as it is:

sys.path.insert(1, path_to_dev_pyworkbooks)

This could be important since 3rd party code may rely on sys.path documentation conformance:

As initialized upon program startup, the first item of this list, path[0], is the directory containing the script that was used to invoke the Python interpreter.

Transfer files to/from session I'm logged in with PuTTY

There's no way to initiate a file transfer back to/from local Windows from a SSH session opened in PuTTY window.

Though PuTTY supports connection-sharing.

While you still need to run a compatible file transfer client (the pscp or psftp), no new login is required, it automatically (if enabled) makes use of an existing PuTTY session.

To enable the sharing see:
Sharing an SSH connection between PuTTY tools.

Alternative way is to use WinSCP, a GUI SFTP/SCP client. While you browse the remote site, you can anytime open SSH terminal to the same site using Open in PuTTY button.

See Opening Session in PuTTY.

With an additional setup, you can even make PuTTY automatically navigate to the same directory you are browsing with WinSCP.

See Opening PuTTY in the Same Directory.

(I'm the author of WinSCP)

How should I validate an e-mail address?

Call This Method where you want to validate email ID.

public static boolean isValid(String email)
{
   String expression = "^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
   CharSequence inputStr = email;
   Pattern pattern = Pattern.compile(expression, Pattern.CASE_INSENSITIVE);
   Matcher matcher = pattern.matcher(inputStr);
   if (matcher.matches()) 
   {
      return true;
   }
   else{
   return false;
   }
}

css selector to match an element without attribute x

Just wanted to add to this, you can have the :not selector in oldIE using selectivizr: http://selectivizr.com/

Google server putty connect 'Disconnected: No supported authentication methods available (server sent: publickey)

Electricity went down and got this error. Solution was to double click your .ppk (Putty Private Key) and enter your password.

Convert 4 bytes to int

The easiest way is:

RandomAccessFile in = new RandomAccessFile("filename", "r"); 
int i = in.readInt();

-- or --

DataInputStream in = new DataInputStream(new BufferedInputStream(
    new FileInputStream("filename"))); 
int i = in.readInt();

Complex CSS selector for parent of active child

Late to the party again but for what it's worth it is possible using jQuery to be a little more succinct. In my case I needed to find the <ul> parent tag for a <span> tag contained in the child <li>. jQuery has the :has selector so it's possible to identify a parent by the children it contains (updated per @Afrowave's comment ref: https://api.jquery.com/has-selector/):

$("ul").has("#someId")

will select the ul element that has a child element with id someId. Or to answer the original question, something like the following should do the trick (untested):

$("li").has(".active")

C compile : collect2: error: ld returned 1 exit status

Go to Advanced System Settings in the computer properties
Click on Advanced
Click for the environment variable
Choose the path option
Change the path option to bin folder of dev c
Apply and save it
Now resave the code in the bin folder in developer c

Javascript to check whether a checkbox is being checked or unchecked

You should be evaluating against the checked property of the checkbox element.

for (i=0; i<arrChecks.length; i++)
{
    var attribute = arrChecks[i].getAttribute("xid")
    if (attribute == elementName)
    {
        // if the current state is checked, unchecked and vice-versa
        if (arrChecks[i].checked)
        {
            arrChecks[i].checked = false;
        } else {
            arrChecks[i].checked = true;
        }

    } else {
        arrChecks[i].checked = false;
    }
}

How to add "Maven Managed Dependencies" library in build path eclipse?

You could also consider to maven-dependency-plugin to your pom:

<plugins>
... 
    <plugin> 
        <artifactId>maven-dependency-plugin</artifactId> 
            <executions> 
                <execution> 
                    <phase>process-resources</phase> 
                    <goals> 
                        <goal>copy-dependencies</goal> 
                    </goals> 
                    <configuration>   
                        <outputDirectory>${project.build.directory}/lib</outputDirectory> 
                    </configuration> 
                </execution> 
            </executions> 
    </plugin> 
...
</plugins>

Than you can run "mvn package" and maven will copy all needed dependencies to your_project_path/target/your_project_name/WEB-INF/lib/ directory. From there you can copy them to your project/lib dir and add as external jars (configuring your project settings buildpath)

How to check if one DateTime is greater than the other in C#

        if (new DateTime(5000) > new DateTime(1000))
        {
            Console.WriteLine("i win");
        }

Show div on scrollDown after 800px

You've got a few things going on there. One, why a class? Do you actually have multiple of these on the page? The CSS suggests you can't. If not you should use an ID - it's faster to select both in CSS and jQuery:

<div id=bottomMenu>You read it all.</div>

Second you've got a few crazy things going on in that CSS - in particular the z-index is supposed to just be a number, not measured in pixels. It specifies what layer this tag is on, where each higher number is closer to the user (or put another way, on top of/occluding tags with lower z-indexes).

The animation you're trying to do is basically .fadeIn(), so just set the div to display: none; initially and use .fadeIn() to animate it:

$('#bottomMenu').fadeIn(2000);

.fadeIn() works by first doing display: (whatever the proper display property is for the tag), opacity: 0, then gradually ratcheting up the opacity.

Full working example:

http://jsfiddle.net/b9chris/sMyfT/

CSS:

#bottomMenu {
    display: none;
    position: fixed;
    left: 0; bottom: 0;
    width: 100%; height: 60px;
    border-top: 1px solid #000;
    background: #fff;
    z-index: 1;
}

JS:

var $win = $(window);

function checkScroll() {
    if ($win.scrollTop() > 100) {
        $win.off('scroll', checkScroll);
        $('#bottomMenu').fadeIn(2000);
    }
}

$win.scroll(checkScroll);

How can I return an empty IEnumerable?

You could return Enumerable.Empty<T>().

MySQL count occurrences greater than 2

SELECT count(word) as count 
FROM words 
GROUP BY word
HAVING count >= 2;

How do I find the parent directory in C#?

No one has provided a solution that would work cross-form. I know it wasn't specifically asked but I am working in a linux environment where most of the solutions (as at the time I post this) would provide an error.

Hardcoding path separators (as well as other things) will give an error in anything but Windows systems.

In my original solution I used:

char filesep = Path.DirectorySeparatorChar;
string datapath = $"..{filesep}..{filesep}";

However after seeing some of the answers here I adjusted it to be:

string datapath = Directory.GetParent(Directory.GetParent(Directory.GetCurrentDirectory()).FullName).FullName;

How to enable CORS in apache tomcat

Check this answer: Set CORS header in Tomcat

Note that you need Tomcat 7.0.41 or higher.

To know where the current instance of Tomcat is located try this:

System.out.println(System.getProperty("catalina.base"));

You'll see the path in the console view.

Then look for /conf/web.xml on that folder, open it and add the lines of the above link.

get path for my .exe

System.Reflection.Assembly.GetEntryAssembly().Location;

error: ‘NULL’ was not declared in this scope

GCC is taking steps towards C++11, which is probably why you now need to include cstddef in order to use the NULL constant. The preferred way in C++11 is to use the new nullptr keyword, which is implemented in GCC since version 4.6. nullptr is not implicitly convertible to integral types, so it can be used to disambiguate a call to a function which has been overloaded for both pointer and integral types:

void f(int x);
void f(void * ptr);

f(0);  // Passes int 0.
f(nullptr);  // Passes void * 0.

proper way to sudo over ssh

Sudo over SSH passing a password, no tty required:

You can use sudo over ssh without forcing ssh to have a pseudo-tty (without the use of the ssh "-t" switch) by telling sudo not to require an interactive password and to just grab the password off stdin. You do this by using the "-S" switch on sudo. This makes sudo listen for the password on stdin, and stop listening when it sees a newline.

Example 1 - Simple Remote Command

In this example, we send a simple whoami command:

$ ssh user@server cat \| sudo --prompt="" -S -- whoami << EOF
> <remote_sudo_password>
root

We're telling sudo not to issue a prompt, and to take its input from stdin. This makes the sudo password passing completely silent so the only response you get back is the output from whoami.

This technique has the benefit of allowing you to run programs through sudo over ssh that themselves require stdin input. This is because sudo is consuming the password over the first line of stdin, then letting whatever program it runs continue to grab stdin.

Example 2 - Remote Command That Requires Its Own stdin

In the following example, the remote command "cat" is executed through sudo, and we are providing some extra lines through stdin for the remote cat to display.

$ ssh user@server cat \| sudo --prompt="" -S -- "cat" << EOF
> <remote_sudo_password>
> Extra line1
> Extra line2
> EOF
Extra line1
Extra line2

The output demonstrates that the <remote_sudo_password> line is being consumed by sudo, and that the remotely executed cat is then displaying the extra lines.

An example of where this would be beneficial is if you want to use ssh to pass a password to a privileged command without using the command line. Say, if you want to mount a remote encrypted container over ssh.

Example 3 - Mounting a Remote VeraCrypt Container

In this example script, we are remotely mounting a VeraCrypt container through sudo without any extra prompting text:

#!/bin/sh
ssh user@server cat \| sudo --prompt="" -S -- "veracrypt --non-interactive --stdin --keyfiles=/path/to/test.key /path/to/test.img /mnt/mountpoint" << EOF
SudoPassword
VeraCryptContainerPassword
EOF

It should be noted that in all the command-line examples above (everything except the script) the << EOF construct on the command line will cause the everything typed, including the password, to be recorded in the local machine's .bash_history. It is therefore highly recommended that for real-world use you either use do it entirely through a script, like the veracrypt example above, or, if on the command line then put the password in a file and redirect that file through ssh.

Example 1a - Example 1 Without Local Command-Line Password

The first example would thus become:

$ cat text_file_with_sudo_password | ssh user@server cat \| sudo --prompt="" -S -- whoami
root

Example 2a - Example 2 Without Local Command-Line Password

and the second example would become:

$ cat text_file_with_sudo_password - << EOF | ssh va1der.net cat \| sudo --prompt="" -S -- cat
> Extra line1
> Extra line2
> EOF
Extra line1
Extra line2

Putting the password in a separate file is unnecessary if you are putting the whole thing in a script, since the contents of scripts do not end up in your history. It still may be useful, though, in case you want to allow users who should not see the password to execute the script.

If statement for strings in python?

Python is a case-sensitive language. All Python keywords are lowercase. Use if, not If.

Also, don't put a colon after the call to print(). Also, indent the print() and exit() calls, as Python uses indentation rather than brackets to represent code blocks.

And also, proceed = "y" or "Y" won't do what you want. Use proceed = "y" and if answer.lower() == proceed:, or something similar.

There's also the fact that your program will exit as long as the input value is not the single character "y" or "Y", which contradicts the prompting of "N" for the alternate case. Instead of your else clause there, use elif answer.lower() == info_incorrect:, with info_incorrect = "n" somewhere beforehand. Then just reprompt for the response or something if the input value was something else.

I'd recommend going through the tutorial in the Python documentation if you're having this much trouble the way you're learning now. http://docs.python.org/tutorial/index.html

Download a file with Android, and showing the progress in a ProgressDialog

We can use the coroutine and work manager for downloading files in kotlin.

Add a dependency in build.gradle

    implementation "androidx.work:work-runtime-ktx:2.3.0-beta01"
    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.1"

WorkManager class

    import android.content.Context
    import android.os.Environment
    import androidx.work.CoroutineWorker
    import androidx.work.WorkerParameters
    import androidx.work.workDataOf
    import com.sa.chat.utils.Const.BASE_URL_IMAGE
    import com.sa.chat.utils.Constants
    import kotlinx.coroutines.delay
    import java.io.BufferedInputStream
    import java.io.File
    import java.io.FileOutputStream
    import java.net.URL

    class DownloadMediaWorkManager(appContext: Context, workerParams: WorkerParameters)
        : CoroutineWorker(appContext, workerParams) {

        companion object {
            const val WORK_TYPE = "WORK_TYPE"
            const val WORK_IN_PROGRESS = "WORK_IN_PROGRESS"
            const val WORK_PROGRESS_VALUE = "WORK_PROGRESS_VALUE"
        }

        override suspend fun doWork(): Result {

            val imageUrl = inputData.getString(Constants.WORK_DATA_MEDIA_URL)
            val imagePath = downloadMediaFromURL(imageUrl)

            return if (!imagePath.isNullOrEmpty()) {
                Result.success(workDataOf(Constants.WORK_DATA_MEDIA_URL to imagePath))
            } else {
                Result.failure()
            }
        }

        private suspend fun downloadMediaFromURL(imageUrl: String?): String? {

            val file = File(
                    getRootFile().path,
                    "IMG_${System.currentTimeMillis()}.jpeg"
            )

            val url = URL(BASE_URL_IMAGE + imageUrl)
            val connection = url.openConnection()
            connection.connect()

            val lengthOfFile = connection.contentLength
            // download the file
            val input = BufferedInputStream(url.openStream(), 8192)
            // Output stream
            val output = FileOutputStream(file)

            val data = ByteArray(1024)
            var total: Long = 0
            var last = 0

            while (true) {

                val count = input.read(data)
                if (count == -1) break
                total += count.toLong()

                val progress = (total * 100 / lengthOfFile).toInt()

                if (progress % 10 == 0) {
                    if (last != progress) {
                        setProgress(workDataOf(WORK_TYPE to WORK_IN_PROGRESS,
                                WORK_PROGRESS_VALUE to progress))
                    }
                    last = progress
                    delay(50)
                }
                output.write(data, 0, count)
            }

            output.flush()
            output.close()
            input.close()

            return file.path

        }

        private fun getRootFile(): File {

            val rootDir = File(Environment.getExternalStorageDirectory().absolutePath + "/AppName")

            if (!rootDir.exists()) {
                rootDir.mkdir()
            }

            val dir = File("$rootDir/${Constants.IMAGE_FOLDER}/")

            if (!dir.exists()) {
                dir.mkdir()
            }
            return File(dir.absolutePath)
        }
    }

Start downloading through work manager in activity class

 private fun downloadImage(imagePath: String?, id: String) {

            val data = workDataOf(WORK_DATA_MEDIA_URL to imagePath)
            val downloadImageWorkManager = OneTimeWorkRequestBuilder<DownloadMediaWorkManager>()
                    .setInputData(data)
                    .addTag(id)
                    .build()

            WorkManager.getInstance(this).enqueue(downloadImageWorkManager)

            WorkManager.getInstance(this).getWorkInfoByIdLiveData(downloadImageWorkManager.id)
                    .observe(this, Observer { workInfo ->

                        if (workInfo != null) {
                            when {
                                workInfo.state == WorkInfo.State.SUCCEEDED -> {
                                    progressBar?.visibility = View.GONE
                                    ivDownload?.visibility = View.GONE
                                }
                                workInfo.state == WorkInfo.State.FAILED || workInfo.state == WorkInfo.State.CANCELLED || workInfo.state == WorkInfo.State.BLOCKED -> {
                                    progressBar?.visibility = View.GONE
                                    ivDownload?.visibility = View.VISIBLE
                                }
                                else -> {
                                    if(workInfo.progress.getString(WORK_TYPE) == WORK_IN_PROGRESS){
                                        val progress = workInfo.progress.getInt(WORK_PROGRESS_VALUE, 0)
                                        progressBar?.visibility = View.VISIBLE
                                        progressBar?.progress = progress
                                        ivDownload?.visibility = View.GONE

                                    }
                                }
                            }
                        }
                    })

        }

TabLayout tab selection

add for your viewpager:

 viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                array.clear();
                switch (position) {
                    case 1:
                        //like a example
                        setViewPagerByIndex(0);
                        break;
                }
            }

            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });

//on handler to prevent crash outofmemory

private void setViewPagerByIndex(final int index){
    Application.getInstance().getHandler().post(new Runnable() {
        @Override
        public void run() {
            viewPager.setCurrentItem(index);
        }
    });
}

How can I check MySQL engine type for a specific table?

If you are a linux user:

To show the engines for all tables for all databases on a mysql server, without tables information_schema, mysql, performance_schema:

less < <({ for i in $(mysql -e "show databases;" | cat | grep -v -e Database-e information_schema -e mysql -e performance_schema); do echo "--------------------$i--------------------";  mysql -e "use $i; show table status;"; done } | column -t)

You might love this, if you are on linux, at least.

Will open all info for all tables in less, press -S to chop overly long lines.

Example output:

--------------------information_schema--------------------
Name                                                        Engine              Version  Row_format  Rows   Avg_row_length  Data_length  Max_data_length     Index_length  Data_free  Auto_increment  Create_time  Update_time  Check_time  C
CHARACTER_SETS                                              MEMORY              10       Fixed       NULL   384             0            16434816            0             0          NULL            2015-07-13   15:48:45     NULL        N
COLLATIONS                                                  MEMORY              10       Fixed       NULL   231             0            16704765            0             0          NULL            2015-07-13   15:48:45     NULL        N
COLLATION_CHARACTER_SET_APPLICABILITY                       MEMORY              10       Fixed       NULL   195             0            16357770            0             0          NULL            2015-07-13   15:48:45     NULL        N
COLUMNS                                                     MyISAM              10       Dynamic     NULL   0               0            281474976710655     1024          0          NULL            2015-07-13   15:48:45     2015-07-13  1
COLUMN_PRIVILEGES                                           MEMORY              10       Fixed       NULL   2565            0            16757145            0             0          NULL            2015-07-13   15:48:45     NULL        N
ENGINES                                                     MEMORY              10       Fixed       NULL   490             0            16574250            0             0          NULL            2015-07-13   15:48:45     NULL        N
EVENTS                                                      MyISAM              10       Dynamic     NULL   0               0            281474976710655     1024          0          NULL            2015-07-13   15:48:45     2015-07-13  1
FILES                                                       MEMORY              10       Fixed       NULL   2677            0            16758020            0             0          NULL            2015-07-13   15:48:45     NULL        N
GLOBAL_STATUS                                               MEMORY              10       Fixed       NULL   3268            0            16755036            0             0          NULL            2015-07-13   15:48:45     NULL        N
GLOBAL_VARIABLES                                            MEMORY              10       Fixed       NULL   3268            0            16755036            0             0          NULL            2015-07-13   15:48:45     NULL        N
KEY_COLUMN_USAGE                                            MEMORY              10       Fixed       NULL   4637            0            16762755            0 

.
.
.

How to properly use unit-testing's assertRaises() with NoneType objects?

Complete snippet would look like the following. It expands @mouad's answer to asserting on error's message (or generally str representation of its args), which may be useful.

from unittest import TestCase


class TestNoneTypeError(TestCase):

  def setUp(self): 
    self.testListNone = None

  def testListSlicing(self):
    with self.assertRaises(TypeError) as ctx:
        self.testListNone[:1]
    self.assertEqual("'NoneType' object is not subscriptable", str(ctx.exception))

How can I check out a GitHub pull request with git?

I'm using hub, a tool from github: https://github.com/github/hub

With hub checking out a pull request locally is kinda easy:

hub checkout https://github.com/owner/repo/pull/1234
or
hub pr checkout 1234

How do I return multiple values from a function?

I prefer:

def g(x):
  y0 = x + 1
  y1 = x * 3
  y2 = y0 ** y3
  return {'y0':y0, 'y1':y1 ,'y2':y2 }

It seems everything else is just extra code to do the same thing.

How do I upgrade PHP in Mac OS X?

There is no built-in package manager. MacPorts doesn't recognize php as an installed package because it didn't install PHP itself.

You could still install it with MacPorts. sudo port install php52 (or whichever version you want) will install PHP.

It won't overwrite the Apple-supplied version. It'll install it under /opt/local. You can add /opt/local to the beginning of your $PATH, and use the MacPorts version in your Apache config.

Round number to nearest integer

I use and may advise the following solution (python3.6):

y = int(x + (x % (1 if x >= 0 else -1)))

It works fine for half-numbers (positives and negatives) and works even faster than int(round(x)):

round_methods = [lambda x: int(round(x)), 
                 lambda x: int(x + (x % (1 if x >= 0 else -1))),
                 lambda x: np.rint(x).astype(int),
                 lambda x: int(proper_round(x))]

for rm in round_methods:
    %timeit rm(112.5)
Out:
201 ns ± 3.96 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
159 ns ± 0.646 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
925 ns ± 7.66 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
1.18 µs ± 8.66 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)

for rm in round_methods:
    print(rm(112.4), rm(112.5), rm(112.6))
    print(rm(-12.4), rm(-12.5), rm(-12.6))
    print('=' * 11)

Out:
112 112 113
-12 -12 -13
===========
112 113 113
-12 -13 -13
===========
112 112 113
-12 -12 -13
===========
112 113 113
-12 -13 -13
===========

How to secure MongoDB with username and password

This is what I did on Ubuntu 18.04:

$ sudo apt install mongodb
$ mongo
> show dbs
> use admin
> db.createUser({  user: "root",  pwd: "rootpw",  roles: [ "root" ]  })  // root user can do anything
> use lefa
> db.lefa.save( {name:"test"} )
> db.lefa.find()
> show dbs
> db.createUser({  user: "lefa",  pwd: "lefapw",  roles: [ { role: "dbOwner", db: "lefa" } ]  }) // admin of a db
> exit
$ sudo vim /etc/mongodb.conf
auth = true
$ sudo systemctl restart mongodb
$ mongo -u "root" -p "rootpw" --authenticationDatabase  "admin"
> use admin
> exit
$ mongo -u "lefa" -p "lefapw" --authenticationDatabase  "lefa"
> use lefa
> exit

Could not load file or assembly for Oracle.DataAccess in .NET

I had the same issue.

Solution was to change the platform of my current solution to x64.

To do that in Visual Studio, right click solution > Configuration Manager > Active Solution Platform.

Forbidden You don't have permission to access /wp-login.php on this server

Make sure your apache .conf files are correct -- then double check your .htaccess files. In this case, my .htaccess were incorrect! I removed some weird stuff no longer needed and it worked. Tada.

"Unmappable character for encoding UTF-8" error

The Java compiler assumes that your input is UTF-8 encoded, either because you specified it to be or because it's your platform default encoding.

However, the data in your .java files is not actually encoded in UTF-8. The problem is probably the ¬ character. Make sure your editor (or IDE) of choice actually safes its file in UTF-8 encoding.

dropping infinite values from dataframes in pandas?

The simplest way would be to first replace infs to NaN:

df.replace([np.inf, -np.inf], np.nan)

and then use the dropna:

df.replace([np.inf, -np.inf], np.nan).dropna(subset=["col1", "col2"], how="all")

For example:

In [11]: df = pd.DataFrame([1, 2, np.inf, -np.inf])

In [12]: df.replace([np.inf, -np.inf], np.nan)
Out[12]:
    0
0   1
1   2
2 NaN
3 NaN

The same method would work for a Series.

C++ pass an array by reference

As you are using C++, the obligatory suggestion that's still missing here, is to use std::vector<double>.

You can easily pass it by reference:

void foo(std::vector<double>& bar) {}

And if you have C++11 support, also have a look at std::array.

For reference:

Does return stop a loop?

In most cases (including this one), return will exit immediately. However, if the return is in a try block with an accompanying finally block, the finally always executes and can "override" the return in the try.

function foo() {
    try {
        for (var i = 0; i < 10; i++) {
            if (i % 3 == 0) {
                return i; // This executes once
            }
        }
    } finally {
        return 42; // But this still executes
    }
}

console.log(foo()); // Prints 42

How to convert a 3D point into 2D perspective projection?

I know it's an old topic but your illustration is not correct, the source code sets up the clip matrix correct.

[fov * aspectRatio][        0        ][        0              ][        0       ]
[        0        ][       fov       ][        0              ][        0       ]
[        0        ][        0        ][(far+near)/(far-near)  ][(2*near*far)/(near-far)]
[        0        ][        0        ][        1              ][        0       ]

some addition to your things:

This clip matrix works only if you are projecting on static 2D plane if you want to add camera movement and rotation:

viewMatrix = clipMatrix * cameraTranslationMatrix4x4 * cameraRotationMatrix4x4;

this lets you rotate the 2D plane and move it around..-

scrollTop animation without jquery

HTML:

<button onclick="scrollToTop(1000);"></button>

1# JavaScript (linear):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const totalScrollDistance = document.scrollingElement.scrollTop;
    let scrollY = totalScrollDistance, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollY will be -Infinity
            scrollY -= totalScrollDistance * (newTimestamp - oldTimestamp) / duration;
            if (scrollY <= 0) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = scrollY;
        }
        oldTimestamp = newTimestamp;
        window.requestAnimationFrame(step);
    }
    window.requestAnimationFrame(step);
}

2# JavaScript (ease in and out):

function scrollToTop (duration) {
    // cancel if already on top
    if (document.scrollingElement.scrollTop === 0) return;

    const cosParameter = document.scrollingElement.scrollTop / 2;
    let scrollCount = 0, oldTimestamp = null;

    function step (newTimestamp) {
        if (oldTimestamp !== null) {
            // if duration is 0 scrollCount will be Infinity
            scrollCount += Math.PI * (newTimestamp - oldTimestamp) / duration;
            if (scrollCount >= Math.PI) return document.scrollingElement.scrollTop = 0;
            document.scrollingElement.scrollTop = cosParameter + cosParameter * Math.cos(scrollCount);
        }
        oldTimestamp = newTimestamp;
        window.requestAnimationFrame(step);
    }
    window.requestAnimationFrame(step);
}
/* 
  Explanation:
  - pi is the length/end point of the cosinus intervall (see below)
  - newTimestamp indicates the current time when callbacks queued by requestAnimationFrame begin to fire.
    (for more information see https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame)
  - newTimestamp - oldTimestamp equals the delta time

    a * cos (bx + c) + d                        | c translates along the x axis = 0
  = a * cos (bx) + d                            | d translates along the y axis = 1 -> only positive y values
  = a * cos (bx) + 1                            | a stretches along the y axis = cosParameter = window.scrollY / 2
  = cosParameter + cosParameter * (cos bx)  | b stretches along the x axis = scrollCount = Math.PI / (scrollDuration / (newTimestamp - oldTimestamp))
  = cosParameter + cosParameter * (cos scrollCount * x)
*/

Note:

Duration in milliseconds (1000ms = 1s)
Second script uses the cos function. Example curve:

enter image description here

3# Simple scrolling library on Github

Bold & Non-Bold Text In A Single UILabel?

It worked for me:

CGFloat boldTextFontSize = 17.0f;

myLabel.text = [NSString stringWithFormat:@"%@ 2012/10/14 %@",@"Updated:",@"21:59 PM"];

NSRange range1 = [myLabel.text rangeOfString:@"Updated:"];
NSRange range2 = [myLabel.text rangeOfString:@"21:59 PM"];

NSMutableAttributedString *attributedText = [[NSMutableAttributedString alloc] initWithString:myLabel.text];

[attributedText setAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:boldTextFontSize]}
                        range:range1];
[attributedText setAttributes:@{NSFontAttributeName:[UIFont boldSystemFontOfSize:boldTextFontSize]}
                        range:range2];

myLabel.attributedText = attributedText;

For Swift version: See Here

How do I remove a key from a JavaScript object?

The delete operator allows you to remove a property from an object.

The following examples all do the same thing.

// Example 1
var key = "Cow";
delete thisIsObject[key]; 

// Example 2
delete thisIsObject["Cow"];

// Example 3
delete thisIsObject.Cow;

If you're interested, read Understanding Delete for an in-depth explanation.

How to get the function name from within that function?

You could use Function.name:

In most implementations of JavaScript, once you have your constructor's reference in scope, you can get its string name from its name property (e.g. Function.name, or Object.constructor.name

You could use Function.callee:

The native arguments.caller method has been deprecated, but most browsers support Function.caller, which will return the actual invoking object (its body of code): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/caller?redirectlocale=en-US&redirectslug=JavaScript%2FReference%2FGlobal_Objects%2FFunction%2Fcaller

You could create a source map:

If what you need is the literal function signature (the "name" of it) and not the object itself, you might have to resort to something a little more customized, like creating an array reference of the API string values you'll need to access frequently. You can map them together using Object.keys() and your array of strings, or look into Mozilla's source maps library on GitHub, for bigger projects: https://github.com/mozilla/source-map

What does '<?=' mean in PHP?

I hope it doesn't get deprecated. While writing <? blah code ?> is fairly unnecessary and confusable with XHTML, <?= isn't, for obvious reasons. Unfortunately I don't use it, because short_open_tag seems to be disabled more and more.

Update: I do use <?= again now, because it is enabled by default with PHP 5.4.0. See http://php.net/manual/en/language.basic-syntax.phptags.php

How do I change select2 box height

I am using Select2 4.0. This works for me. I only have one Select2 control.

.select2-selection.select2-selection--multiple {
    min-height: 25px;
    max-height: 25px;
}

How to slice an array in Bash

See the Parameter Expansion section in the Bash man page. A[@] returns the contents of the array, :1:2 takes a slice of length 2, starting at index 1.

A=( foo bar "a  b c" 42 )
B=("${A[@]:1:2}")
C=("${A[@]:1}")       # slice to the end of the array
echo "${B[@]}"        # bar a  b c
echo "${B[1]}"        # a  b c
echo "${C[@]}"        # bar a  b c 42
echo "${C[@]: -2:2}"  # a  b c 42 # The space before the - is necesssary

Note that the fact that "a b c" is one array element (and that it contains an extra space) is preserved.

How I can check if an object is null in ruby on rails 2?

In your example, you can simply replace null with `nil and it will work fine.

require 'erb'

template = <<EOS
<% if (@objectname != nil) then %>
  @objectname is not nil
<% else %>
  @objectname is nil
<% end %>
EOS

@objectname = nil
ERB.new(template, nil, '>').result # => "  @objectname is nil\n"

@objectname = 'some name'
ERB.new(template, nil, '>').result # => "  @objectname is not nil\n"

Contrary to what the other poster said, you can see above that then works fine in Ruby. It's not common, but it is fine.

#blank? and #present? have other implications. Specifically, if the object responds to #empty?, they will check whether it is empty. If you go to http://api.rubyonrails.org/ and search for "blank?", you will see what objects it is defined on and how it works. Looking at the definition on Object, we see "An object is blank if it’s false, empty, or a whitespace string. For example, “”, “ ”, nil, [], and {} are all blank." You should make sure that this is what you want.

Also, nil is considered false, and anything other than false and nil is considered true. This means you can directly place the object in the if statement, so a more canonical way of writing the above would be

require 'erb'

template = <<EOS
<% if @objectname %>
  @objectname is not nil
<% else %>
  @objectname is nil
<% end %>
EOS

@objectname = nil
ERB.new(template, nil, '>').result # => "  @objectname is nil\n"

@objectname = 'some name'
ERB.new(template, nil, '>').result # => "  @objectname is not nil\n"

If you explicitly need to check nil and not false, you can use the #nil? method, for which nil is the only object that will cause this to return true.

nil.nil?          # => true
false.nil?        # => false
Object.new.nil?   # => false

Using JavaMail with TLS

We actually have some notification code in our product that uses TLS to send mail if it is available.

You will need to set the Java Mail properties. You only need the TLS one but you might need SSL if your SMTP server uses SSL.

Properties props = new Properties();
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.auth", "true");  // If you need to authenticate
// Use the following if you need SSL
props.put("mail.smtp.socketFactory.port", d_port);
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");

You can then either pass this to a JavaMail Session or any other session instantiator like Session.getDefaultInstance(props).

module.exports vs exports in Node.js

1.exports -> use as singleton utility
2. module-exports -> use as logical objects such as service , model etc

How to concatenate two IEnumerable<T> into a new IEnumerable<T>?

// The answer that I was looking for when searching
public void Answer()
{
    IEnumerable<YourClass> first = this.GetFirstIEnumerableList();
    // Assign to empty list so we can use later
    IEnumerable<YourClass> second = new List<YourClass>();

    if (IwantToUseSecondList)
    {
        second = this.GetSecondIEnumerableList();  
    }
    IEnumerable<SchemapassgruppData> concatedList = first.Concat(second);
}

How to determine the version of the C++ standard used by the compiler?

Normally you should use __cplusplus define to detect c++17, but by default microsoft compiler does not define that macro properly, see https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/ - you need to either modify project settings to include /Zc:__cplusplus switch, or you could use syntax like this:

#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
     //C++17 specific stuff here
#endif

Get list of all input objects using JavaScript, without accessing a form object

(See update at end of answer.)

You can get a NodeList of all of the input elements via getElementsByTagName (DOM specification, MDC, MSDN), then simply loop through it:

var inputs, index;

inputs = document.getElementsByTagName('input');
for (index = 0; index < inputs.length; ++index) {
    // deal with inputs[index] element.
}

There I've used it on the document, which will search the entire document. It also exists on individual elements (DOM specification), allowing you to search only their descendants rather than the whole document, e.g.:

var container, inputs, index;

// Get the container element
container = document.getElementById('container');

// Find its child `input` elements
inputs = container.getElementsByTagName('input');
for (index = 0; index < inputs.length; ++index) {
    // deal with inputs[index] element.
}

...but you've said you don't want to use the parent form, so the first example is more applicable to your question (the second is just there for completeness, in case someone else finding this answer needs to know).

Update: getElementsByTagName is an absolutely fine way to do the above, but what if you want to do something slightly more complicated, like just finding all of the checkboxes instead of all of the input elements?

That's where the useful querySelectorAll comes in: It lets us get a list of elements that match any CSS selector we want. So for our checkboxes example:

var checkboxes = document.querySelectorAll("input[type=checkbox]");

You can also use it at the element level. For instance, if we have a div element in our element variable, we can find all of the spans with the class foo that are inside that div like this:

var fooSpans = element.querySelectorAll("span.foo");

querySelectorAll and its cousin querySelector (which just finds the first matching element instead of giving you a list) are supported by all modern browsers, and also IE8.

What are the rules for casting pointers in C?

char c = '5'

A char (1 byte) is allocated on stack at address 0x12345678.

char *d = &c;

You obtain the address of c and store it in d, so d = 0x12345678.

int *e = (int*)d;

You force the compiler to assume that 0x12345678 points to an int, but an int is not just one byte (sizeof(char) != sizeof(int)). It may be 4 or 8 bytes according to the architecture or even other values.

So when you print the value of the pointer, the integer is considered by taking the first byte (that was c) and other consecutive bytes which are on stack and that are just garbage for your intent.

Center align a column in twitter bootstrap

With bootstrap 3 the best way to go about achieving what you want is ...with offsetting columns. Please see these examples for more detail:
http://getbootstrap.com/css/#grid-offsetting

In short, and without seeing your divs here's an example what might help, without using any custom classes. Just note how the "col-6" is used and how half of that is 3 ...so the "offset-3" is used. Splitting equally will allow the centered spacing you're going for:

<div class="container">
<div class="col-sm-6 col-sm-offset-3">
your centered, floating column
</div></div>

How to check if spark dataframe is empty?

If you are using Pypsark, you could also do:

len(df.head(1)) > 0

Laravel Check If Related Model Exists

I had to completely refactor my code when I updated my PHP version to 7.2+ because of bad usage of the count($x) function. This is a real pain and its also extremely scary as there are hundreds usages, in different scenarios and there is no one rules fits all..

Rules I followed to refactor everything, examples:

$x = Auth::user()->posts->find(6); (check if user has a post id=6 using ->find())

[FAILS] if(count($x)) { return 'Found'; } 
[GOOD] if($x) { return 'Found'; }

$x = Auth::user()->profile->departments; (check if profile has some departments, there can have many departments)

[FAILS] if(count($x)) { return 'Found'; }
[GOOD] if($x->count()) { return 'Found'; }

$x = Auth::user()->profile->get(); (check if user has a profile after using a ->get())

[FAILS] if(count($x)) { return 'Found'; }
[GOOD] if($x->count()) { return 'Found'; }

Hopes this can help, even 5 years after the question has been asked, this stackoverflow post has helped me a lot!

Subprocess changing directory

I guess these days you would do:

import subprocess

subprocess.run(["pwd"], cwd="sub-dir")

PowerShell: Comparing dates

Late but more complete answer in point of getting the most advanced date from $Output

## Q:\test\2011\02\SO_5097125.ps1
## simulate object input with a here string 
$Output = @"
"Date"
"Monday, April 08, 2013 12:00:00 AM"
"Friday, April 08, 2011 12:00:00 AM"
"@ -split '\r?\n' | ConvertFrom-Csv

## use Get-Date and calculated property in a pipeline
$Output | Select-Object @{n='Date';e={Get-Date $_.Date}} |
    Sort-Object Date | Select-Object -Last 1 -Expand Date

## use Get-Date in a ForEach-Object
$Output.Date | ForEach-Object{Get-Date $_} |
    Sort-Object | Select-Object -Last 1

## use [datetime]::ParseExact
## the following will only work if your locale is English for day, month day abbrev.
$Output.Date | ForEach-Object{
    [datetime]::ParseExact($_,'dddd, MMMM dd, yyyy hh:mm:ss tt',$Null)
} | Sort-Object | Select-Object -Last 1

## for non English locales
$Output.Date | ForEach-Object{
    [datetime]::ParseExact($_,'dddd, MMMM dd, yyyy hh:mm:ss tt',[cultureinfo]::InvariantCulture)
} | Sort-Object | Select-Object -Last 1

## in case the day month abbreviations are in other languages, here German
## simulate object input with a here string 
$Output = @"
"Date"
"Montag, April 08, 2013 00:00:00"
"Freidag, April 08, 2011 00:00:00"
"@ -split '\r?\n' | ConvertFrom-Csv
$CIDE = New-Object System.Globalization.CultureInfo("de-DE")
$Output.Date | ForEach-Object{
    [datetime]::ParseExact($_,'dddd, MMMM dd, yyyy HH:mm:ss',$CIDE)
} | Sort-Object | Select-Object -Last 1

Read from database and fill DataTable

Connection object is for illustration only. The DataAdapter is the key bit:

Dim strSql As String = "SELECT EmpCode,EmpID,EmpName FROM dbo.Employee"
Dim dtb As New DataTable
Using cnn As New SqlConnection(connectionString)
  cnn.Open()
  Using dad As New SqlDataAdapter(strSql, cnn)
    dad.Fill(dtb)
  End Using
  cnn.Close()
End Using

Why does CSV file contain a blank line in between each data line when outputting with Dictwriter in Python

From http://docs.python.org/library/csv.html#csv.writer:

If csvfile is a file object, it must be opened with the ‘b’ flag on platforms where that makes a difference.

In other words, when opening the file you pass 'wb' as opposed to 'w'.
You can also use a with statement to close the file when you're done writing to it.
Tested example below:

from __future__ import with_statement # not necessary in newer versions
import csv
headers=['id', 'year', 'activity', 'lineitem', 'datum']
with open('file3.csv','wb') as fou: # note: 'wb' instead of 'w'
    output = csv.DictWriter(fou,delimiter=',',fieldnames=headers)
    output.writerow(dict((fn,fn) for fn in headers))
    output.writerows(rows)

How to set default value to all keys of a dict object in python?

Use defaultdict

from collections import defaultdict
a = {} 
a = defaultdict(lambda:0,a)
a["anything"] # => 0

This is very useful for case like this,where default values for every key is set as 0:

results ={ 'pre-access' : {'count': 4, 'pass_count': 2},'no-access' : {'count': 55, 'pass_count': 19}
for k,v in results.iteritems():
  a['count'] += v['count']
  a['pass_count'] += v['pass_count']

How to print a string multiple times?

If you want to print something = '@' 2 times in a line, you can write this:

print(something * 2)

If you want to print 4 lines of something, you can use a for loop:

for i in range(4):
     print(something)

SQL Server - INNER JOIN WITH DISTINCT

Try this:

select distinct a.FirstName, a.LastName, v.District
from AddTbl a 
  inner join ValTbl v
  on a.LastName = v.LastName
order by a.FirstName;

Or this (it does the same, but the syntax is different):

select distinct a.FirstName, a.LastName, v.District
from AddTbl a, ValTbl v
where a.LastName = v.LastName
order by a.FirstName;

What is the difference between String and string in C#?

string is a reserved word, but String is just a class name. This means that string cannot be used as a variable name by itself.

If for some reason you wanted a variable called string, you'd see only the first of these compiles:

StringBuilder String = new StringBuilder();  // compiles
StringBuilder string = new StringBuilder();  // doesn't compile

If you really want a variable name called string you can use @ as a prefix:

StringBuilder @string = new StringBuilder();

Another critical difference: Stack Overflow highlights them differently.

Given two directory trees, how can I find out which files differ by content?

Channel compatriot 'billings' (of freenode/#centos fame) shared his method with me:

diff -Naur dir1/ dir2

Including the final directory forward slash doesn't matter.

Also, it appears the -u option is not available on some older/server versions of diff.

The difference in diffs:

# diff -Nar /tmp/dir1 /tmp/dir2/
diff -Nar /tmp/dir1/file /tmp/dir2/file
28a29
> TEST

# diff -qr /tmp/dir1/ /tmp/dir2/
Files /tmp/dir1/file and /tmp/dir2/file differ

Constructor in an Interface?

An interface defines a contract for an API, that is a set of methods that both implementer and user of the API agree upon. An interface does not have an instanced implementation, hence no constructor.

The use case you describe is akin to an abstract class in which the constructor calls a method of an abstract method which is implemented in an child class.

The inherent problem here is that while the base constructor is being executed, the child object is not constructed yet, and therfore in an unpredictable state.

To summarize: is it asking for trouble when you call overloaded methods from parent constructors, to quote mindprod:

In general you must avoid calling any non-final methods in a constructor. The problem is that instance initialisers / variable initialisation in the derived class is performed after the constructor of the base class.

Where does PostgreSQL store the database?

picmate's answer is right. on windows the main DB folder location is (at least on my installation)

C:\PostgreSQL\9.2\data\base\

and not in program files.

his 2 scripts, will give you the exact directory/file(s) you need:

SELECT oid from pg_database WHERE datname = <database_name>;
SELECT relname, relfilenode FROM pg_class WHERE relname = <table_name>;

mine is in datname 16393 and relfilenode 41603

How to get the file path from HTML input form in Firefox 3

Actually, just before FF3 was out, I did some experiments, and FF2 sends only the filename, like did Opera 9.0. Only IE sends the full path. The behavior makes sense, because the server doesn't have to know where the user stores the file on his computer, it is irrelevant to the upload process. Unless you are writing an intranet application and get the file by direct network access!

What have changed (and that's the real point of the bug item you point to) is that FF3 no longer let access to the file path from JavaScript. And won't let type/paste a path there, which is more annoying for me: I have a shell extension which copies the path of a file from Windows Explorer to the clipboard and I used it a lot in such form. I solved the issue by using the DragDropUpload extension. But this becomes off-topic, I fear.

I wonder what your Web forms are doing to stop working with this new behavior.

[EDIT] After reading the page linked by Mike, I see indeed intranet uses of the path (identify a user for example) and local uses (show preview of an image, local management of files). User Jam-es seems to provide a workaround with nsIDOMFile (not tried yet).

How to print pandas DataFrame without index

Anyone working on Jupyter Notebook to print DataFrame without index column, this worked for me:

display(table.hide_index())

SQL update from one Table to another based on a ID match

For SQL Server 2008 + Using MERGE rather than the proprietary UPDATE ... FROM syntax has some appeal.

As well as being standard SQL and thus more portable it also will raise an error in the event of there being multiple joined rows on the source side (and thus multiple possible different values to use in the update) rather than having the final result be undeterministic.

MERGE INTO Sales_Import
   USING RetrieveAccountNumber
      ON Sales_Import.LeadID = RetrieveAccountNumber.LeadID
WHEN MATCHED THEN
   UPDATE 
      SET AccountNumber = RetrieveAccountNumber.AccountNumber;

Unfortunately the choice of which to use may not come down purely to preferred style however. The implementation of MERGE in SQL Server has been afflicted with various bugs. Aaron Bertrand has compiled a list of the reported ones here.

Printing image with PrintDocument. how to adjust the image to fit paper size

Not to trample on BBoy's already decent answer, but I've done the code that maintains aspect ratio. I took his suggestion, so he should get partial credit here!

PrintDocument pd = new PrintDocument();
pd.DefaultPageSettings.PrinterSettings.PrinterName = "Printer Name";
pd.DefaultPageSettings.Landscape = true; //or false!
pd.PrintPage += (sender, args) =>
{
    Image i = Image.FromFile(@"C:\...\...\image.jpg");
    Rectangle m = args.MarginBounds;

    if ((double)i.Width / (double)i.Height > (double)m.Width / (double)m.Height) // image is wider
    {
        m.Height = (int)((double)i.Height / (double)i.Width * (double)m.Width);
    }
    else
    {
        m.Width = (int)((double)i.Width / (double)i.Height * (double)m.Height);
    }
    args.Graphics.DrawImage(i, m);
};
pd.Print();

Angular 2.0 router not working on reloading the browser

Add imports:

import { HashLocationStrategy, LocationStrategy } from '@angular/common';

And in NgModule provider, add:

providers: [{provide: LocationStrategy, useClass: HashLocationStrategy}]

In main index.html File of the App change the base href to ./index.html from /

The App when deployed in any server will give a real url for the page which can be accessed from any external application.

How to add shortcut keys for java code in eclipse

I've been Eclipse-free for over a year now, but I believe Eclipse calls these "Templates". Look in your settings for them. You invoke a template by typing its abbreviation and pressing the normal code completion hotkey (ctrl+space by default) or using the Tab key. The standard eclipse shortcut for System.out.println() is "sysout", so "sysout" would do what you want.

Here's another stackoverflow question that has some more details about it: How to use the "sysout" snippet in Eclipse with selected text?

Performance of FOR vs FOREACH in PHP

It's 2020 and stuffs had greatly evolved with php 7.4 and opcache.

Here is the OP^ benchmark, ran as unix CLI, without the echo and html parts.

Test ran locally on a regular computer.

php -v

PHP 7.4.6 (cli) (built: May 14 2020 10:02:44) ( NTS )

Modified benchmark script:

<?php 
 ## preperations; just a simple environment state

  $test_iterations = 100;
  $test_arr_size = 1000;

  // a shared function that makes use of the loop; this should
  // ensure no funny business is happening to fool the test
  function test($input)
  {
    //echo '<!-- '.trim($input).' -->';
  }

  // for each test we create a array this should avoid any of the
  // arrays internal representation or optimizations from getting
  // in the way.

  // normal array
  $test_arr1 = array();
  $test_arr2 = array();
  $test_arr3 = array();
  // hash tables
  $test_arr4 = array();
  $test_arr5 = array();

  for ($i = 0; $i < $test_arr_size; ++$i)
  {
    mt_srand();
    $hash = md5(mt_rand());
    $key = substr($hash, 0, 5).$i;

    $test_arr1[$i] = $test_arr2[$i] = $test_arr3[$i] = $test_arr4[$key] = $test_arr5[$key]
      = $hash;
  }

  ## foreach

  $start = microtime(true);
  for ($j = 0; $j < $test_iterations; ++$j)
  {
    foreach ($test_arr1 as $k => $v)
    {
      test($v);
    }
  }
  echo 'foreach '.(microtime(true) - $start)."\n";  

  ## foreach (using reference)

  $start = microtime(true);
  for ($j = 0; $j < $test_iterations; ++$j)
  {
    foreach ($test_arr2 as &$value)
    {
      test($value);
    }
  }
  echo 'foreach (using reference) '.(microtime(true) - $start)."\n";

  ## for

  $start = microtime(true);
  for ($j = 0; $j < $test_iterations; ++$j)
  {
    $size = count($test_arr3);
    for ($i = 0; $i < $size; ++$i)
    {
      test($test_arr3[$i]);
    }
  }
  echo 'for '.(microtime(true) - $start)."\n";  

  ## foreach (hash table)

  $start = microtime(true);
  for ($j = 0; $j < $test_iterations; ++$j)
  {
    foreach ($test_arr4 as $k => $v)
    {
      test($v);
    }
  }
  echo 'foreach (hash table) '.(microtime(true) - $start)."\n";

  ## for (hash table)

  $start = microtime(true);
  for ($j = 0; $j < $test_iterations; ++$j)
  {
    $keys = array_keys($test_arr5);
    $size = sizeOf($test_arr5);
    for ($i = 0; $i < $size; ++$i)
    {
      test($test_arr5[$keys[$i]]);
    }
  }
  echo 'for (hash table) '.(microtime(true) - $start)."\n";

Output:

foreach 0.0032877922058105
foreach (using reference) 0.0029420852661133
for 0.0025191307067871
foreach (hash table) 0.0035080909729004
for (hash table) 0.0061779022216797

As you can see the evolution is insane, about 560 time faster than reported in 2012.

On my machines and servers, following my numerous experiments, basics for loops are the fastest. This is even clearer using nested loops ($i $j $k..)

It is also the most flexible in usage, and has a better readability from my view.

How can I get screen resolution in java?

Here is a snippet of code I often use. It returns the full available screen area (even on multi-monitor setups) while retaining the native monitor positions.

public static Rectangle getMaximumScreenBounds() {
    int minx=0, miny=0, maxx=0, maxy=0;
    GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
    for(GraphicsDevice device : environment.getScreenDevices()){
        Rectangle bounds = device.getDefaultConfiguration().getBounds();
        minx = Math.min(minx, bounds.x);
        miny = Math.min(miny, bounds.y);
        maxx = Math.max(maxx,  bounds.x+bounds.width);
        maxy = Math.max(maxy, bounds.y+bounds.height);
    }
    return new Rectangle(minx, miny, maxx-minx, maxy-miny);
}

On a computer with two full-HD monitors, where the left one is set as the main monitor (in Windows settings), the function returns

java.awt.Rectangle[x=0,y=0,width=3840,height=1080]

On the same setup, but with the right monitor set as the main monitor, the function returns

java.awt.Rectangle[x=-1920,y=0,width=3840,height=1080]

Basic Authentication Using JavaScript

EncodedParams variable is redefined as params variable will not work. You need to have same predefined call to variable, otherwise it looks possible with a little more work. Cheers! json is not used to its full capabilities in php there are better ways to call json which I don't recall at the moment.

remove first element from array and return the array minus the first element

This can be done in one line with lodash _.tail:

_x000D_

var arr = ["item 1", "item 2", "item 3", "item 4"];_x000D_
console.log(_.tail(arr));

_x000D_

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

_x000D_

How and when to use ‘async’ and ‘await’

All the answers here use Task.Delay() or some other built in async function. But here is my example that use none of those async functions:

// Starts counting to a large number and then immediately displays message "I'm counting...". 
// Then it waits for task to finish and displays "finished, press any key".
static void asyncTest ()
{
    Console.WriteLine("Started asyncTest()");
    Task<long> task = asyncTest_count();
    Console.WriteLine("Started counting, please wait...");
    task.Wait(); // if you comment this line you will see that message "Finished counting" will be displayed before we actually finished counting.
    //Console.WriteLine("Finished counting to " + task.Result.ToString()); // using task.Result seems to also call task.Wait().
    Console.WriteLine("Finished counting.");
    Console.WriteLine("Press any key to exit program.");
    Console.ReadLine();
}

static async Task<long> asyncTest_count()
{
    long k = 0;
    Console.WriteLine("Started asyncTest_count()");
    await Task.Run(() =>
    {
        long countTo = 100000000;
        int prevPercentDone = -1;
        for (long i = 0; i <= countTo; i++)
        {
            int percentDone = (int)(100 * (i / (double)countTo));
            if (percentDone != prevPercentDone)
            {
                prevPercentDone = percentDone;
                Console.Write(percentDone.ToString() + "% ");
            }

            k = i;
        }
    });
    Console.WriteLine("");
    Console.WriteLine("Finished asyncTest_count()");
    return k;
}

Removing a list of characters in string

you could use something like this

def replace_all(text, dic):
  for i, j in dic.iteritems():
    text = text.replace(i, j)
  return text

This code is not my own and comes from here its a great article and dicusses in depth doing this

Split an NSString to access one particular piece

Use [myString componentsSeparatedByString:@"/"]

find path of current folder - cmd

2015-03-30: Edited - Missing information has been added

To retrieve the current directory you can use the dynamic %cd% variable that holds the current active directory

set "curpath=%cd%"

This generates a value with a ending backslash for the root directory, and without a backslash for the rest of directories. You can force and ending backslash for any directory with

for %%a in ("%cd%\") do set "curpath=%%~fa"

Or you can use another dynamic variable: %__CD__% that will return the current active directory with an ending backslash.

Also, remember the %cd% variable can have a value directly assigned. In this case, the value returned will not be the current directory, but the assigned value. You can prevent this with a reference to the current directory

for %%a in (".\") do set "curpath=%%~fa"

Up to windows XP, the %__CD__% variable has the same behaviour. It can be overwritten by the user, but at least from windows 7 (i can't test it on Vista), any change to the %__CD__% is allowed but when the variable is read, the changed value is ignored and the correct current active directory is retrieved (note: the changed value is still visible using the set command).

BUT all the previous codes will return the current active directory, not the directory where the batch file is stored.

set "curpath=%~dp0"

It will return the directory where the batch file is stored, with an ending backslash.

BUT this will fail if in the batch file the shift command has been used

shift
echo %~dp0

As the arguments to the batch file has been shifted, the %0 reference to the current batch file is lost.

To prevent this, you can retrieve the reference to the batch file before any shifting, or change the syntax to shift /1 to ensure the shift operation will start at the first argument, not affecting the reference to the batch file. If you can not use any of this options, you can retrieve the reference to the current batch file in a call to a subroutine

@echo off
    setlocal enableextensions

    rem Destroy batch file reference
    shift
    echo batch folder is "%~dp0"

    rem Call the subroutine to get the batch folder 
    call :getBatchFolder batchFolder
    echo batch folder is "%batchFolder%"

    exit /b

:getBatchFolder returnVar
    set "%~1=%~dp0" & exit /b

This approach can also be necessary if when invoked the batch file name is quoted and a full reference is not used (read here).

In MySQL, how to copy the content of one table to another table within the same database?

CREATE TABLE target_table SELECT * FROM source_table;

It just create a new table with same structure as of source table and also copy all rows from source_table into target_table.

CREATE TABLE target_table SELECT * FROM source_table WHERE condition;

If you need some rows to be copied into target_table, then apply a condition inside where clause

Callback when CSS3 transition finishes

The accepted answer currently fires twice for animations in Chrome. Presumably this is because it recognizes webkitAnimationEnd as well as animationEnd. The following will definitely only fires once:

/* From Modernizr */
function whichTransitionEvent(){

    var el = document.createElement('fakeelement');
    var transitions = {
        'animation':'animationend',
        'OAnimation':'oAnimationEnd',
        'MSAnimation':'MSAnimationEnd',
        'WebkitAnimation':'webkitAnimationEnd'
    };

    for(var t in transitions){
        if( transitions.hasOwnProperty(t) && el.style[t] !== undefined ){
            return transitions[t];
        }
    }
}

$("#elementToListenTo")
    .on(whichTransitionEvent(),
        function(e){
            console.log('Transition complete!  This is the callback!');
            $(this).off(e);
        });

Authorize a non-admin developer in Xcode / Mac OS

I am on Snow Leopard and this one didn't quite work for me. But the following procedure worked:

First added another account with admin privileges by ticking "Allow user to administer this computer" under Accounts, for example an account with username test
Logged into the test account
Launched Xcode, compiled and ran my iPhone project. All ok, no errors were thrown related to permissions
Logged out of the test account
Logged in with the another account having admin privileges
Took away the admin priviliges from the test account by removing the tick from "Allow user to administer this computer" under Accounts
Logged back into the test account
Deleted the iPhone project directory and again checked out from the repository (in my case svn)
Launched Xcode, compiled and ran the project. I didn't get any errors and the App ran well in the iPhone Simulator.

Get value of a specific object property in C# without knowing the class behind

Use reflection

System.Reflection.PropertyInfo pi = item.GetType().GetProperty("name");
String name = (String)(pi.GetValue(item, null));

List of foreign keys and the tables they reference in Oracle DB

If you need all the foreign keys of the user then use the following script

SELECT a.constraint_name, a.table_name, a.column_name,  c.owner, 
       c_pk.table_name r_table_name,  b.column_name r_column_name
  FROM user_cons_columns a
  JOIN user_constraints c ON a.owner = c.owner
       AND a.constraint_name = c.constraint_name
  JOIN user_constraints c_pk ON c.r_owner = c_pk.owner
       AND c.r_constraint_name = c_pk.constraint_name
  JOIN user_cons_columns b ON C_PK.owner = b.owner
       AND  C_PK.CONSTRAINT_NAME = b.constraint_name AND b.POSITION = a.POSITION     
 WHERE c.constraint_type = 'R'

based on Vincent Malgrat code

Failed to execute 'postMessage' on 'DOMWindow': https://www.youtube.com !== http://localhost:9000

Just wishing to avoid the console error, I solved this using a similar approach to Artur's earlier answer, following these steps:

Downloaded the YouTube Iframe API (from https://www.youtube.com/iframe_api) to a local yt-api.js file.
Removed the code which inserted the www-widgetapi.js script.
Downloaded the www-widgetapi.js script (from https://s.ytimg.com/yts/jsbin/www-widgetapi-vfl7VfO1r/www-widgetapi.js) to a local www-widgetapi.js file.
Replaced the targetOrigin argument in the postMessage call which was causing the error in the console, with a "*" (indicating no preference - see https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage).
Appended the modified www-widgetapi.js script to the end of the yt-api.js script.

This is not the greatest solution (patched local script to maintain, losing control of where messages are sent) but it solved my issue.

Please see the security warning about removing the targetOrigin URI stated here before using this solution - https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

Patched yt-api.js example

INSERT ... ON DUPLICATE KEY (do nothing)

Use ON DUPLICATE KEY UPDATE ...,
Negative : because the UPDATE uses resources for the second action.

Use INSERT IGNORE ...,
Negative : MySQL will not show any errors if something goes wrong, so you cannot handle the errors. Use it only if you don’t care about the query.

Uncaught ReferenceError: angular is not defined - AngularJS not working

Use the ng-click directive:

<button my-directive ng-click="alertFn()">Click Me!</button>

// In <script>:
app.directive('myDirective' function() {
  return function(scope, element, attrs) {
    scope.alertFn = function() { alert('click'); };
  };
};

Note that you don't need my-directive in this example, you just need something to bind alertFn on the current scope.

Update: You also want the angular libraries loaded before your <script> block.

How to align flexbox columns left and right?

There are different ways but simplest would be to use the space-between see the example at the end

#container {    
    border: solid 1px #000;
    display: flex;    
    flex-direction: row;
    justify-content: space-between;
    padding: 10px;
    height: 50px;
}

.item {
    width: 20%;
    border: solid 1px #000;
    text-align: center;
}

see the example

How do I position an image at the bottom of div?

< img style="vertical-align: bottom" src="blah.png" >

Works for me. Inside a parallax div as well.

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

No, the dataType option is for parsing the received data.

To post JSON, you will need to stringify it yourself via JSON.stringify and set the processData option to false.

$.ajax({
    url: url,
    type: "POST",
    data: JSON.stringify(data),
    processData: false,
    contentType: "application/json; charset=UTF-8",
    complete: callback
});

Note that not all browsers support the JSON object, and although jQuery has .parseJSON, it has no stringifier included; you'll need another polyfill library.

Some projects cannot be imported because they already exist in the workspace error in Eclipse

You have one occult directory named ".metadata" in workspace directory. Close Eclipse, delete ".metadata" and open Eclipse. When eclipse ask you about workspace make sure that ".metadata" isn't in workspace directory and click "ok" button to select default workspace.

Fragment transaction animation: slide in and slide out

There is three way to transaction animation in fragment.

Transitions

So need to use one of the built-in Transitions, use the setTranstion() method:

getSupportFragmentManager()
        .beginTransaction()
        .setTransition( FragmentTransaction.TRANSIT_FRAGMENT_OPEN )
        .show( m_topFragment )
        .commit()

Custom Animations

You can also customize the animation by using the setCustomAnimations() method:

getSupportFragmentManager()
        .beginTransaction()
        .setCustomAnimations( R.anim.slide_up, 0, 0, R.anim.slide_down)
        .show( m_topFragment )
        .commit()

slide_up.xml

<?xml version="1.0" encoding="utf-8"?>
<objectAnimator
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:interpolator="@android:anim/accelerate_decelerate_interpolator"
        android:propertyName="translationY"
        android:valueType="floatType"
        android:valueFrom="1280"
        android:valueTo="0"
        android:duration="@android:integer/config_mediumAnimTime"/>

slide_down.xml

<?xml version="1.0" encoding="utf-8"?>
<objectAnimator
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:interpolator="@android:anim/accelerate_decelerate_interpolator"
        android:propertyName="translationY"
        android:valueType="floatType"
        android:valueFrom="0"
        android:valueTo="1280"
        android:duration="@android:integer/config_mediumAnimTime"/>

Multiple Animations

Finally, It's also possible to kick-off multiple fragment animations in a single transaction. This allows for a pretty cool effect where one fragment is sliding up and the other slides down at the same time:

getSupportFragmentManager()
        .beginTransaction()
        .setCustomAnimations( R.anim.abc_slide_in_top, R.anim.abc_slide_out_top ) // Top Fragment Animation
        .show( m_topFragment )
        .setCustomAnimations( R.anim.abc_slide_in_bottom, R.anim.abc_slide_out_bottom ) // Bottom Fragment Animation
        .show( m_bottomFragment )
        .commit()

To more detail you can visit URL

Note:- You can check animation according to your requirement because above may be have issue.

How can I check if a file exists in Perl?

#!/usr/bin/perl -w

$fileToLocate = '/whatever/path/for/file/you/are/searching/MyFile.txt';
if (-e $fileToLocate) {
    print "File is present";
}

Label encoding across multiple columns in scikit-learn

It is possible to do this all in pandas directly and is well-suited for a unique ability of the replace method.

First, let's make a dictionary of dictionaries mapping the columns and their values to their new replacement values.

transform_dict = {}
for col in df.columns:
    cats = pd.Categorical(df[col]).categories
    d = {}
    for i, cat in enumerate(cats):
        d[cat] = i
    transform_dict[col] = d

transform_dict
{'location': {'New_York': 0, 'San_Diego': 1},
 'owner': {'Brick': 0, 'Champ': 1, 'Ron': 2, 'Veronica': 3},
 'pets': {'cat': 0, 'dog': 1, 'monkey': 2}}

Since this will always be a one to one mapping, we can invert the inner dictionary to get a mapping of the new values back to the original.

inverse_transform_dict = {}
for col, d in transform_dict.items():
    inverse_transform_dict[col] = {v:k for k, v in d.items()}

inverse_transform_dict
{'location': {0: 'New_York', 1: 'San_Diego'},
 'owner': {0: 'Brick', 1: 'Champ', 2: 'Ron', 3: 'Veronica'},
 'pets': {0: 'cat', 1: 'dog', 2: 'monkey'}}

Now, we can use the unique ability of the replace method to take a nested list of dictionaries and use the outer keys as the columns, and the inner keys as the values we would like to replace.

df.replace(transform_dict)
   location  owner  pets
0         1      1     0
1         0      2     1
2         0      0     0
3         1      1     2
4         1      3     1
5         0      2     1

We can easily go back to the original by again chaining the replace method

df.replace(transform_dict).replace(inverse_transform_dict)
    location     owner    pets
0  San_Diego     Champ     cat
1   New_York       Ron     dog
2   New_York     Brick     cat
3  San_Diego     Champ  monkey
4  San_Diego  Veronica     dog
5   New_York       Ron     dog

reducing number of plot ticks

To solve the issue of customisation and appearance of the ticks, see the Tick Locators guide on the matplotlib website

ax.xaxis.set_major_locator(plt.MaxNLocator(3))

Would set the total number of ticks in the x-axis to 3, and evenly distribute it across the axis.

There is also a nice tutorial about this

Bootstrap 3 - set height of modal window according to screen size

Pure CSS solution, using calc

.modal-body {
    max-height: calc(100vh - 200px);
    overflow-y: auto;
}

200px may be adjusted in accordance to height of header & footer

Bash function to find newest file matching pattern

Use the find command.

Assuming you're using Bash 4.2+, use -printf '%T+ %p\n' for file timestamp value.

find $DIR -type f -printf '%T+ %p\n' | sort -r | head -n 1 | cut -d' ' -f2

Example:

find ~/Downloads -type f -printf '%T+ %p\n' | sort -r | head -n 1 | cut -d' ' -f2

For a more useful script, see the find-latest script here: https://github.com/l3x/helpers

What is Gradle in Android Studio?

I refer two tutorial to write the Answer one,two

Gradle is a general purpose, declarative build tool. It is general purpose because it can be used to build pretty much anything you care to implement in the build script. It is declarative since you don't want to see lots of code in the build file, which is not readable and less maintainable. So, while Gradle provides the idea of conventions and a simple and declarative build, it also makes the tool adaptable and developers the ability to extend. It also provides an easy way to customize the default behavior and different hooks to add any third-party features.

Gradle combines the good parts of both tools and provides additional features and uses Groovy as a Domain Specific Language (DSL). It has power and flexibility of Ant tool with Maven features such as build life cycle and ease of use.

Why Gradle? Why Now?

The build tool's response is to add scripting functionality through nonstandard extension mechanisms. You end up mixing scripting code with XML or invoking external scripts from your build logic. It's easy to imagine that you'll need to add more and more custom code over time. As a result, you inevitably introduce accidental complexity, and maintainability goes out the window.

Let's say you want to copy a file to a specific location when you're building the release version of your project. To identify the version, you check a string in the metadata describing your project. If it matches a specific numbering scheme (for example, 1.0-RELEASE), you copy the file from point A to point B. From an outside perspective, this may sound like a trivial task. If you have to rely on XML, the build language of many traditional tools, expressing this simple logic becomes fairly difficult.

Evolution of Java Build Tools

Java build logic has to be described in XML. XML is great for describing hierarchical data but falls short on expressing program flow and conditional logic. As a build script grows in complexity, maintaining the building code becomes a nightmare.

In Ant, you make the JAR target depend on the compile target. Ant doesn't give any guidance on how to structure your project. Though it allows for maximum flexibility, Ant makes each build script unique and hard to understand. External libraries required by your project are usually checked into version control because there is no automated mechanism to pull them from a central location.

Maven 1, released in July 2004, tried to ease that process. It provided a standardized project and directory structure, as well as dependency management. Unfortunately, custom logic is hard to implement

Gradle fits right into that generation of build tools and satisfies many requirements of modern build tools (Figure 1). It provides an expressive DSL, a convention over configuration approach, and powerful dependency management. It makes the right move to abandon XML and introduce the dynamic language Groovy to define your build logic. Sounds compelling, doesn't it?

Gradle combines the best features of other build tools.

Gradle's Compelling Feature Set

Why Build Your Java Projects with Gradle Rather than Ant or Maven?

The default build tool for Android (and the new star of build tools on the JVM) is designed to ease scripting of complex, multi-language builds. Should you change to it, though, if you're using Ant or Maven?

The key to unlocking Gradle's power features within your build script lies in discovering and applying its domain model, as shown in below image.

Gradle can't know all the requirements specific to your enterprise build. By exposing hooks into lifecycle phases, Gradle allows for monitoring and configuring the build script's execution behavior.

Gradle establishes a vocabulary for its model by exposing a DSL implemented in Groovy. When dealing with a complex problem domain, in this case, the task of building software, being able to use a common language to express your logic can be a powerful tool.

Another example is the way you can express dependencies to external libraries, a very common problem solved by build tools. Out-of-the-box Gradle provides you with two configuration blocks for your build script that allow you to define the dependencies and repositories that you want to retrieve them from. If the standard DSL elements don't fit your needs, you can even introduce your own vocabulary through Gradle's extension mechanism.

Integration with Other Build Tools

Gradle plays well with its predecessors' Ant, Maven, and Ivy, as shown in the image below.

Automating Your Project from Build to Deployment

In image: Stages of a deployment pipeline.

Compiling the code
Running unit and integration tests
Performing static code analysis and generating test coverage
Creating the distribution
Provisioning the target environment
Deploying the deliverable
Performing smoke and automated functional tests

I refer two tutorial to write the Answer one,two

Forking / Multi-Threaded Processes | Bash

Here's my thread control function:

#!/bin/bash
# This function just checks jobs in background, don't do more things.
# if jobs number is lower than MAX, then return to get more jobs;
# if jobs number is greater or equal to MAX, then wait, until someone finished.

# Usage:
#   thread_max 8
#   thread_max 0    # wait, until all jobs completed

thread_max() {
    local CHECK_INTERVAL="3s"
    local CUR_THREADS=
    local MAX=
    [[ $1 ]] && MAX=$1 || return 127

    # reset MAX value, 0 is easy to remember
    [ $MAX -eq 0 ] && {
        MAX=1
        DEBUG "waiting for all tasks finish"
    }

    while true; do
        CUR_THREADS=`jobs -p | wc -w`

        # workaround about jobs bug. If don't execute it explicitily,
        # CUR_THREADS will stick at 1, even no jobs running anymore.
        jobs &>/dev/null

        DEBUG "current thread amount: $CUR_THREADS"
        if [ $CUR_THREADS -ge $MAX ]; then
            sleep $CHECK_INTERVAL
        else
            return 0
        fi
    done
}

How to install sklearn?

pip install numpy scipy scikit-learn

if you don't have pip, install it using

python get-pip.py

Download get-pip.py from the following link. or use curl to download it.

curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py

Return date as ddmmyyyy in SQL Server

CONVERT style 103 is dd/mm/yyyy. Then use the REPLACE function to eliminate the slashes.

SELECT REPLACE(CONVERT(CHAR(10), [MyDateTime], 103), '/', '')

Maven2: Missing artifact but jars are in place

As i tried all above as my friends said but nothing worked actually, I was facing same problem and found solution in some different way my issue starts when i added below repository

<dependency>
  <groupId>dom4j</groupId>
  <artifactId>dom4j</artifactId>
  <version>20040902.021138</version>
</dependency>

and my problem starts...so then i changed the version and took previous version and it removed all error. So i think this issue can because of the version we are adding in POM.xml file.

How can I remove the gloss on a select element in Safari on Mac?

i have used this and solved my

-webkit-appearance:none;

Maven Unable to locate the Javac Compiler in:

If you we are doing all above steps that may be confused and our problem is just missing tools.jre so just add tools.jre by the following steps and problem is solved.

Step 1 : In eclipse go to Windows -> preferences

Step 2 : Java -> Installed JREs (Double click on it)

Step 3 : Click Edit button -> Click Add External JARs

Step 4 : Now select tools.jar path

now apply changes and it works fine.

Here is screenshoot

Writing to CSV with Python adds blank lines

If you're using Python 2.x on Windows you need to change your line open('test.csv', 'w') to open('test.csv', 'wb'). That is you should open the file as a binary file.

However, as stated by others, the file interface has changed in Python 3.x.

Getting started with OpenCV 2.4 and MinGW on Windows 7

1. Installing OpenCV 2.4.3

First, get OpenCV 2.4.3 from sourceforge.net. Its a self-file-extracting so just double click the file to start installation. Install it in a directory, say C:\.

OpenCV self-extracting

Wait until all files get extracted. It will create a new directory C:\opencv which contains OpenCV header files, libraries, code samples, etc.

Now you need to add C:\opencv\build\x86\mingw\bin directory to your system PATH. This directory contains OpenCV DLLs which is required for running your code.

Open Control Panel → System → Advanced system settings → Advanced Tab → Environment variables...

You will see a window like shown below:

Add OpenCV DLL directory to system path

On the System Variables section,
select Path (1), click Edit... (2), add C:\opencv\build\x86\mingw\bin (3) then click Ok.

This will completes the OpenCV 2.4.3 installation on your computer.

2. Installing MinGW compiler suite

I highly recommend you to use gcc (GNU Compiler Collection) for compiling your code. gcc is the compiler suite widely available in Linux systems and MinGW is the native port for Windows.

Download the MinGW installer from Sourceforge.net and double click to start installation. Just follow the wizard and select the directory to be installed, say C:\MinGW.

Select directory in MinGW installation

Select "C Compiler" and "C++ Compiler" to be installed.

Select components to be installed

The installer will download some packages from the internet so you have to wait for a while. After the installation finished, add C:\MinGW\bin to your system path using the steps described before.

Add MinGW bin directory to system path

To test if your MinGW installation is success, open a command-line box and type: gcc. If everything is ok, it will display this message:

gcc: fatal error: no input files
compilation terminated

This completes the MinGW installation, now is the time to write your "Hello, World!" program.

3. Write a sample code

Open your text editor and type the code below and save the file to loadimg.cpp.

#include "opencv2/highgui/highgui.hpp"
#include <iostream>

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
  Mat im = imread(argc == 2 ? argv[1] : "lena.jpg", 1);
  if (im.empty())
  {
    cout << "Cannot open image!" << endl;
    return -1;
  }

  imshow("image", im);
  waitKey(0);

  return 0;
}

Put lena.jpg or any image you like in the same directory with the file above. Open a command-line box and compile the code above by typing:

g++ -I"C:\opencv\build\include" -L"C:\opencv\build\x86\mingw\lib" loadimg.cpp -lopencv_core243 -lopencv_highgui243 -o loadimg

If it compiles successfully, it will create an executable named loadimg.exe.

Type:

loadimg

To execute the program. Result:

The result of your first OpenCV program

4. Where to go from here?

Now that your OpenCV environment is ready, what's next?

Go to the samples dir → C:\opencv\samples\cpp.
Read and compile some code.
Write your own code.

Export query result to .csv file in SQL Server 2008

One more method worth to mention here:

SQLCMD -S SEVERNAME -E -Q "SELECT COLUMN FROM TABLE" -s "," -o "c:\test.csv"

NOTE: I don't see any network admin let you run powershell scripts

How can I get color-int from color resource?

or if you have a function(string text,string color) and you need to pass the Resource Color String you can do as follow

String.valueOf(getResources().getColor(R.color.enurse_link_color)

How do you get assembler output from C/C++ source in gcc?

I don't see this possibility among answers, probably because the question is from 2008, but in 2018 you can use Matt Goldbolt's online website https://godbolt.org

You can also locally git clone and run his project https://github.com/mattgodbolt/compiler-explorer

GIT fatal: ambiguous argument 'HEAD': unknown revision or path not in the working tree

Jacob Helwig mentions in his answer that:

It looks like rev-parse is being used without sufficient error checking before-hand

Commit 62f162f from Jeff King (peff) should improve the robustness of git rev-parse in Git 1.9/2.0 (Q1 2014) (in addition of commit 1418567):

For cases where we do not match (e.g., "doesnotexist..HEAD"), we would then want to try to treat the argument as a filename.
try_difference() gets this right, and always unmunges in this case.
However, try_parent_shorthand() never unmunges, leading to incorrect error messages, or even incorrect results:

$ git rev-parse foobar^@
foobar
fatal: ambiguous argument 'foobar': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

how to remove new lines and returns from php string?

This should be like

str_replace("\n", '', $str);
str_replace("\r", '', $str);
str_replace("\r\n", '', $str);

How do you reinstall an app's dependencies using npm?

You can do this with one simple command:

npm ci

Documentation:

npm ci
Install a project with a clean slate

How to remove line breaks from a file in Java?

String text = readFileAsString("textfile.txt").replaceAll("\n", "");

Even though the definition of trim() in oracle website is "Returns a copy of the string, with leading and trailing whitespace omitted."

the documentation omits to say that new line characters (leading and trailing) will also be removed.

In short String text = readFileAsString("textfile.txt").trim(); will also work for you. (Checked with Java 6)

Node.js/Express routing with get params

Your route isn't ok, it should be like this (with ':')

app.get('/documents/:format/:type', function (req, res) {
   var format = req.params.format,
       type = req.params.type;
});

Also you cannot interchange parameter order unfortunately. For more information on req.params (and req.query) check out the api reference here.

Unable to Cast from Parent Class to Child Class

I have seen most of the people saying explicit parent to child casting is not possible, that actually is not true. Let's take a revised start and try proving it by examples.

As we know in .net all castings have two broad categories.

For Value type
For Reference type (in your case its reference type)

Reference type has further three main situational cases in which any scenario can lie.

Child to Parent (Implicit casting - Always successful)

Case 1. Child to any direct or indirect parent

Employee e = new Employee();
Person p = (Person)e; //Allowed

Parent to Child (Explicit casting - Can be successful)

Case 2. Parent variable holding parent object (Not allowed)

Person p = new Person();  // p is true Person object
Employee e = (Employee)p; //Runtime err : InvalidCastException <-------- Yours issue

Case 3. Parent variable holding child object (Always Successful)

Note: Because objects has polymorphic nature, it is possible for a variable of a parent class type to hold a child type.

Person p = new Employee(); // p actually is Employee
Employee e = (Employee)p; // Casting allowed

Conclusion : After reading above all, hope it will make sense now like how parent to child conversion is possible(Case 3).

Answer To The Question :

Your answer is in case 2.Where you can see such casting is not allowed by OOP and you are trying to violate one of OOP's basic rule.So always choose safe path.

Further more, to avoid such exceptional situations .net has recommended using is/as operators those will help you to take informed decisions and provide safe casting.

How to delete and update a record in Hive

The CLI told you where is your mistake : delete WHAT? from student ...

Delete : How to delete/truncate tables from Hadoop-Hive?

Update : Update , SET option in Hive

How to store(bitmap image) and retrieve image from sqlite database in android?

Setting Up the database

public class DatabaseHelper extends SQLiteOpenHelper {
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "database_name";

    // Table Names
    private static final String DB_TABLE = "table_image";

    // column names
    private static final String KEY_NAME = "image_name";
    private static final String KEY_IMAGE = "image_data";

    // Table create statement
    private static final String CREATE_TABLE_IMAGE = "CREATE TABLE " + DB_TABLE + "("+ 
                       KEY_NAME + " TEXT," + 
                       KEY_IMAGE + " BLOB);";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        // creating table
        db.execSQL(CREATE_TABLE_IMAGE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // on upgrade drop older tables
        db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);

        // create new table
        onCreate(db);
    }
}

Insert in the Database:

public void addEntry( String name, byte[] image) throws SQLiteException{
    SQLiteDatabase database = this.getWritableDatabase();
    ContentValues cv = new  ContentValues();
    cv.put(KEY_NAME,    name);
    cv.put(KEY_IMAGE,   image);
    database.insert( DB_TABLE, null, cv );
}

Retrieving data:

 byte[] image = cursor.getBlob(1);

Note:

Before inserting into database, you need to convert your Bitmap image into byte array first then apply it using database query.
When retrieving from database, you certainly have a byte array of image, what you need to do is to convert byte array back to original image. So, you have to make use of BitmapFactory to decode.

Below is an Utility class which I hope could help you:

public class DbBitmapUtility {

    // convert from bitmap to byte array
    public static byte[] getBytes(Bitmap bitmap) {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(CompressFormat.PNG, 0, stream);
        return stream.toByteArray();
    }

    // convert from byte array to bitmap
    public static Bitmap getImage(byte[] image) {
        return BitmapFactory.decodeByteArray(image, 0, image.length);
    }
}

Further reading
If you are not familiar how to insert and retrieve into a database, go through this tutorial.

Creating a new DOM element from an HTML string using built-in DOM methods or Prototype

You can create valid DOM nodes from a string using:

document.createRange().createContextualFragment()

The following example adds a button element in the page taking the markup from a string:

_x000D_

let html = '<button type="button">Click Me!</button>';_x000D_
let fragmentFromString = function (strHTML) {_x000D_
  return document.createRange().createContextualFragment(strHTML);_x000D_
}_x000D_
let fragment = fragmentFromString(html);_x000D_
document.body.appendChild(fragment);

_x000D_

HTML/CSS: Making two floating divs the same height

I had similar problem and in my opinion best option is to use just a little bit of javascript or jquery.

You can get wanted divs to be same height by getting highest div value and applying that value to all other divs. If you have many divs and many solutions i suggest to write little advance js code to find out which of all divs is the highest and then use it's value.

With jquery and 2 divs it's very simple, here is example code:

$('.smaller-div').css('height',$('.higher-div').css('height'));

And for the end, there is 1 last thing. Their padding (top and bottom) must be the same ! If one have larger padding you need to eliminate padding difference.

How to rename JSON key

By using map function you can do that. Please refer below code.

var userDetails = [{
  "_id":"5078c3a803ff4197dc81fbfb",
  "email":"[email protected]",
  "image":"some_image_url",
  "name":"Name 1"
},{
  "_id":"5078c3a803ff4197dc81fbfc",
  "email":"[email protected]",
  "image":"some_image_url",
  "name":"Name 2"
}];

var formattedUserDetails = userDetails.map(({ _id:id, email, image, name }) => ({
  id,
  email,
  image,
  name
}));
console.log(formattedUserDetails);

Django DB Settings 'Improperly Configured' Error

In my case, I got this when trying to run Django tests through PyCharm. I think it is because PyCharm does not load the initial Django project settings, i.e. those that manage.py shell runs initially. One can add them to the start of the testing script or just run the tests using manage.py test.

Versions:

Python 3.5 (in virtualenv)
PyCharm 2016.3.2 Professional
Django 1.10

R adding days to a date

Just use

 as.Date("2001-01-01") + 45

from base R, or date functionality in one of the many contributed packages. My RcppBDT package wraps functionality from Boost Date_Time including things like 'date of third Wednesday' in a given month.

Edit: And egged on by @Andrie, here is a bit more from RcppBDT (which is mostly a test case for Rcpp modules, really).

R> library(RcppBDT)
Loading required package: Rcpp
R> 
R> str(bdt)
Reference class 'Rcpp_date' [package ".GlobalEnv"] with 0 fields
 and 42 methods, of which 31 are possibly relevant:
   addDays, finalize, fromDate, getDate, getDay, getDayOfWeek, getDayOfYear, 
   getEndOfBizWeek, getEndOfMonth, getFirstDayOfWeekAfter,
   getFirstDayOfWeekInMonth, getFirstOfNextMonth, getIMMDate, getJulian, 
   getLastDayOfWeekBefore, getLastDayOfWeekInMonth, getLocalClock, getModJulian,
   getMonth, getNthDayOfWeek, getUTC, getWeekNumber, getYear, initialize, 
   setEndOfBizWeek, setEndOfMonth, setFirstOfNextMonth, setFromLocalClock,
   setFromUTC, setIMMDate, subtractDays
R> bdt$fromDate( as.Date("2001-01-01") )
R> bdt$addDays( 45 )
R> print(bdt)
[1] "2001-02-15"
R>

How to set level logging to DEBUG in Tomcat?

JULI logging levels for Tomcat

SEVERE - Serious failures

WARNING - Potential problems

INFO - Informational messages

CONFIG - Static configuration messages

FINE - Trace messages

FINER - Detailed trace messages

FINEST - Highly detailed trace messages

You can find here more https://documentation.progress.com/output/ua/OpenEdge_latest/index.html#page/pasoe-admin/tomcat-logging.html

How can I check if a view is visible or not in Android?

Although View.getVisibility() does get the visibility, its not a simple true/false. A view can have its visibility set to one of three things.

View.VISIBLE The view is visible.

View.INVISIBLE The view is invisible, but any spacing it would normally take up will still be used. Its "invisible"

View.GONE The view is gone, you can't see it and it doesn't take up the "spot".

So to answer your question, you're looking for:

if (myImageView.getVisibility() == View.VISIBLE) {
    // Its visible
} else {
    // Either gone or invisible
}

How do I resize a Google Map with JavaScript after it has loaded?

The popular answer google.maps.event.trigger(map, "resize"); didn't work for me alone.

Here was a trick that assured that the page had loaded and that the map had loaded as well. By setting a listener and listening for the idle state of the map you can then call the event trigger to resize.

$(document).ready(function() {
    google.maps.event.addListener(map, "idle", function(){
        google.maps.event.trigger(map, 'resize'); 
    });
});

This was my answer that worked for me.

Angular 2.0 and Modal Dialog

Check ASUI dialog which create at runtime. There is no need of hide and show logic. Simply service will create a component at runtime using AOT ASUI NPM

Programs & Examples On #Cfpreferences

Check if list is empty in C#

Change Input to Upper Case

What is managed or unmanaged code in programming?

How to break out from a ruby block?

Common sources of unterminated string literal

BeanFactory not initialized or already closed - call 'refresh' before

How to trigger SIGUSR1 and SIGUSR2?

Combining COUNT IF AND VLOOK UP EXCEL

How to send POST request?

MongoDB: update every document on one field

Why can't Python find shared objects that are in directories in sys.path?

Get jQuery version from inspecting the jQuery object

How to read values from the querystring with ASP.NET Core?

The import org.junit cannot be resolved

Batch File: ( was unexpected at this time

Formatting "yesterday's" date in python

What characters are valid in a URL?

Make index.html default, but allow index.php to be visited if typed in

Get parent directory of running script

How to schedule a periodic task in Java?

Programmatically set the initial view controller using Storyboards

Dynamically add event listener

Check if a string contains a string in C++

How to get next/previous record in MySQL?

How can I create a Windows .exe (standalone executable) using Java/Eclipse?

callback to handle completion of pipe

How do I store the select column in a variable?

How can I display an image from a file in Jupyter Notebook?

Bubble Sort Homework

css rotate a pseudo :after or :before content:""

Enable/disable buttons with Angular

How do you deploy Angular apps?

How can I sort a std::map first by value, then by key?

How to use "Share image using" sharing Intent to share images in android?

java.lang.UnsatisfiedLinkError no *****.dll in java.library.path

foreach with index

Detect if device is iOS

How to export collection to CSV in MongoDB?

How to clear https proxy setting of NPM?

Can you set a border opacity in CSS?

Call web service in excel

Get startup type of Windows service using PowerShell

how to make window.open pop up Modal?

Connect to docker container as user other than root

Laravel 5 not finding css files

Changing iframe src with Javascript

How to create a pivot query in sql server without aggregate function

Correct way to detach from a container without stopping it

Convert a Pandas DataFrame to a dictionary

Delete default value of an input text on click

How to use MapView in android using google map V2?

HTTP Status 405 - Request method 'POST' not supported (Spring MVC)

Share data between AngularJS controllers

javascript password generator

SQL Add foreign key to existing column

JavaScript Array Push key value

How should I choose an authentication library for CodeIgniter?

Check if Cookie Exists

How can I view an old version of a file with Git?

In a nutshell

Step by step

Encode URL in JavaScript?

html "data-" attribute as javascript parameter

Fitting a Normal distribution to 1D data

git rm - fatal: pathspec did not match any files

what is the use of "response.setContentType("text/html")" in servlet

successful/fail message pop up box after submit?

Excel VBA - Delete empty rows

What is the exact location of MySQL database tables in XAMPP folder?

In Python, how do you convert seconds since epoch to a `datetime` object?

How to run Ruby code from terminal?

Single Result from Database by using mySQLi

Webpack - webpack-dev-server: command not found

To prevent a memory leak, the JDBC Driver has been forcibly unregistered

How to set the title text color of UIButton?

accepting HTTPS connections with self-signed certificates

Using WGET to run a cronjob PHP

Why use sys.path.append(path) instead of sys.path.insert(1, path)?

Transfer files to/from session I'm logged in with PuTTY