Programs & Examples On #System variable

How to set java_home on Windows 7?

if you have not restarted your computer after installing jdk just restart your computer.

if you want to make a portable java and set path before using java, just make a batch file i explained below.

if you want to run this batch file when your computer start just put your batch file shortcut in startup folder. In windows 7 startup folder is "C:\Users\user\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup"

make a batch file like this:

set Java_Home=C:\Program Files\Java\jdk1.8.0_11
set PATH=%PATH%;C:\Program Files\Java\jdk1.8.0_11\bin

note: java_home and path are variables. you can make any variable as you wish. for example set amir=good_boy and you can see amir by %amir% or you can see java_home by %java_home%

How to merge two json string in Python?

Merging json objects is fairly straight forward but has a few edge cases when dealing with key collisions. The biggest issues have to do with one object having a value of a simple type and the other having a complex type (Array or Object). You have to decide how you want to implement that. Our choice when we implemented this for json passed to chef-solo was to merge Objects and use the first source Object's value in all other cases.

This was our solution:

from collections import Mapping
import json


original = json.loads(jsonStringA)
addition = json.loads(jsonStringB)

for key, value in addition.iteritems():
    if key in original:
        original_value = original[key]
        if isinstance(value, Mapping) and isinstance(original_value, Mapping):
            merge_dicts(original_value, value)
        elif not (isinstance(value, Mapping) or 
                  isinstance(original_value, Mapping)):
            original[key] = value
        else:
            raise ValueError('Attempting to merge {} with value {}'.format(
                key, original_value))
    else:
        original[key] = value

You could add another case after the first case to check for lists if you want to merge those as well, or for specific cases when special keys are encountered.

Create a .csv file with values from a Python list

To create and write into a csv file

The below example demonstrate creating and writing a csv file. to make a dynamic file writer we need to import a package import csv, then need to create an instance of the file with file reference Ex:- with open("D:\sample.csv","w",newline="") as file_writer

here if the file does not exist with the mentioned file directory then python will create a same file in the specified directory, and "w" represents write, if you want to read a file then replace "w" with "r" or to append to existing file then "a". newline="" specifies that it removes an extra empty row for every time you create row so to eliminate empty row we use newline="", create some field names(column names) using list like fields=["Names","Age","Class"], then apply to writer instance like writer=csv.DictWriter(file_writer,fieldnames=fields) here using Dictionary writer and assigning column names, to write column names to csv we use writer.writeheader() and to write values we use writer.writerow({"Names":"John","Age":20,"Class":"12A"}) ,while writing file values must be passed using dictionary method , here the key is column name and value is your respective key value

import csv 

with open("D:\\sample.csv","w",newline="") as file_writer:

   fields=["Names","Age","Class"]

   writer=csv.DictWriter(file_writer,fieldnames=fields)

   writer.writeheader()

   writer.writerow({"Names":"John","Age":21,"Class":"12A"})

One line ftp server in python

I dont know about a one-line FTP server, but if you do

python -m SimpleHTTPServer

It'll run an HTTP server on 0.0.0.0:8000, serving files out of the current directory. If you're looking for a way to quickly get files off a linux box with a web browser, you cant beat it.

PHP removing a character in a string

I think that it's better to use simply str_replace, like the manual says:

If you don't need fancy replacing rules (like regular expressions), you should always use this function instead of ereg_replace() or preg_replace().

<?
$badUrl = "http://www.site.com/backend.php?/c=crud&m=index&t=care";
$goodUrl = str_replace('?/', '?', $badUrl);

Field 'id' doesn't have a default value?

add a default value for your Id lets say in your table definition this will solve your problem.

Which programming language for cloud computing?

This is always fascinating. I am not a cloud developer, but based on my research there is nothing significantly different than what many of us have been doing off and on for decades. The server is platform specific. If you want to write platform agnostic code for your server that is fine, but unnecessary based on whoever your cloud server provider is. I think the biggest difference I've seen so far is the concept of providing a large set of services for the front end client to process. the front end, I'm assuming is predominantly web or web app development. As most browsers can handle LAMP vs Microsoft stack well enough, then you are still back to whatever your flavor of the month is. The only difference I truly am seeing from what I did 20 years ago in a highly distributed network environment are higher level protocol (HTTP vs. TCP/UDP). Maybe I am wrong and would welcome the education, but then again I've been doing this a long time and still have not seen anything I would consider revolutionary or significantly different, though languages like Java, C#, Python, Ruby, etc are significantly simpler to program in which is a mixed bag as the bar is lowered for those are are not familiar with writing optimized code. PAAS and SAAS to me seem to be some of the keys in the new technology, but been doing some of this to off and on for 20 years :)

Using both Python 2.x and Python 3.x in IPython Notebook

Use sudo pip3 install jupyter for installing jupyter for python3 and sudo pip install jupyter for installing jupyter notebook for python2. Then, you can call ipython kernel install command to enable both types of notebook to choose from in jupyter notebook.

Using multiple IF statements in a batch file

IF EXIST "somefile.txt" (
  IF EXIST "someotherfile.txt" (
    SET var="somefile.txt","someotherfile.txt"
  )
) ELSE (
  CALL :SUB
)
:SUB
ECHO Sorry... nothin' there.
GOTO:EOF

Is this feasible?

SETLOCAL ENABLEDELAYEDEXPANSION
IF EXIST "somefile.txt" (
  SET var="somefile.txt"
  IF EXIST "someotherfile.txt" (
    SET var=!var!,"someotherfile.txt"
  )
) ELSE (
  IF EXIST "someotherfile.txt" (
    SET var="someotherfile.txt"
  ) ELSE (
  GOTO:EOF
  )
)

how to release localhost from Error: listen EADDRINUSE

On Linux (Ubuntu derivatives at least)

killall node

is easier than this form.

ps | grep <something>
kill <somepid>

Neither will work if you have a orphaned child holding the port. Instead, do this:

netstat -punta | grep <port>

If the port is being held you'll see something like this:

tcp           0      0.0.0.0:<port>          0.0.0.*       LISTEN     <pid>/<parent>

Now kill by pid:

kill -9 <pid>

Can't get Gulp to run: cannot find module 'gulp-util'

Any answer didn't help in my case. What eventually helped was removing bower and gulp (I use both of them in my project):

npm remove -g bower
npm remove -g gulp

After that I installed them again:

npm install -g bower
npm install -g gulp

Now it works just fine.

Error: Expression must have integral or unscoped enum type

Your variable size is declared as: float size;

You can't use a floating point variable as the size of an array - it needs to be an integer value.

You could cast it to convert to an integer:

float *temp = new float[(int)size];

Your other problem is likely because you're writing outside of the bounds of the array:

   float *temp = new float[size];

    //Getting input from the user
    for (int x = 1; x <= size; x++){
        cout << "Enter temperature " << x << ": ";

        // cin >> temp[x];
        // This should be:
        cin >> temp[x - 1];
    }

Arrays are zero based in C++, so this is going to write beyond the end and never write the first element in your original code.

Convert byte to string in Java

String str = "0x63";
int temp = Integer.parseInt(str.substring(2, 4), 16);
char c = (char)temp;
System.out.print(c);

To draw an Underline below the TextView in Android

A simple and sustainable solution is to create a layer-list and make it as the background of your TextView:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:left="-5dp"
        android:right="-5dp"
        android:top="-5dp">
        <shape>
            <stroke
                android:width="1.5dp"
                android:color="@color/colorAccent" />
        </shape>
    </item>
</layer-list>

Stuck while installing Visual Studio 2015 (Update for Microsoft Windows (KB2999226))

I would like to give you a background on Universal CRT this would help you in understanding as to why the system should be updated before installing vc_redist.x64.exe. A large portion of the C-runtime moved into the OS in Windows 10 (ucrtbase.dll) and is serviced just like any other OS DLL (e.g. kernel32.dll). It is no longer serviced by Visual Studio directly. MSU packages are the file type for Windows Updates.

In order to get the Windows 10 Universal CRT to earlier OSes, Windows Update packages were created to bring this OS component downlevel. KB2999226 brings the Windows 10 RTM Universal CRT to downlevel platforms (Windows Vista through Windows 8.1). KB3118401 brings Windows 10 November Update to the Universal CRT to downlevel platforms.

Windows XP (latest SP) is an exception here. Windows Servicing does not provide downlevel packages for that OS, so Visual Studio (Visual C++) provides a mechanism to install the UCRT into System32 via the VCRedist and MSMs.

1.The Windows Universal Runtime is included in the VC Redist exe package as it has dependency on the Windows Universal Runtime (KB2999226). Windows 10 is the only OS that ships the UCRT in-box. All prior OSes obtain the UCRT via Windows Update only. This applies to all Vista->8.1 and associated Server SKUs.

For Windows 7, 8, and 8.1 the Windows Universal Runtime must be installed via KB2999226. However it has a prerequisite update KB2919355 which contains updates that facilitate installing the KB2999226 package.

  1. Why does KB2999226 not always install when the runtime is installed from the redistributable? What could prevent KB2999226 from installing as part of the runtime? The UCRT MSU included in the VCRedist is installed by making a call into the Windows Update service and the KB can fail to install based upon Windows Update service activity/state: 1) If the machine has not updated to the required servicing baseline, the UCRT MSU will be viewed as being “Not Applicable”. Ensure KB2919355 is installed. Also, there were known issues with KB2919355 so before this the following hotfix should be installed. KB2939087 KB2975061 2) If the Windows Update service is installing other updates when the VCRedist installs, you can either see long delays or errors indicating the machine is busy. a. This one can be resolved by waiting and trying again later (which may be why installing via Windows Update UI at a later time succeeds). 3) If the Windows Update service is in a non-ready state, you can see errors reflecting that. a. We recently investigated a failure with an error code indicating the WUSA service was shutting down.

  2. To identify if the prerequisite KB2919355 is installed there are 2 options: Registry key: 64bit hive HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\Packages\Package_for_KB2919355~31bf3856ad364e35~amd64~~6.3.1.14 CurrentState = 112 32bit hive HKLM\SOFTWARE[WOW6432Node]Microsoft\Windows\CurrentVersion\Component Based Servicing\Packages\Package_for_KB2919355~31bf3856ad364e35~x86~~6.3.1.14 CurrentState = 112

Or check the file version of: C:\Windows\SysWOW64\wuaueng.dll C:\Windows\System32\wuaueng.dll 7.9.9600.17031 or later

PHP json_decode() returns NULL with valid JSON?

$k=preg_replace('/\s+/', '',$k); 

did it for me. And yes, testing on Chrome. Thx to user2254008

Django gives Bad Request (400) when DEBUG = False

The ALLOWED_HOSTS list should contain fully qualified host names, not urls. Leave out the port and the protocol. If you are using 127.0.0.1, I would add localhost to the list too:

ALLOWED_HOSTS = ['127.0.0.1', 'localhost']

You could also use * to match any host:

ALLOWED_HOSTS = ['*']

Quoting the documentation:

Values in this list can be fully qualified names (e.g. 'www.example.com'), in which case they will be matched against the request’s Host header exactly (case-insensitive, not including port). A value beginning with a period can be used as a subdomain wildcard: '.example.com' will match example.com, www.example.com, and any other subdomain of example.com. A value of '*' will match anything; in this case you are responsible to provide your own validation of the Host header (perhaps in a middleware; if so this middleware must be listed first in MIDDLEWARE_CLASSES).

Bold emphasis mine.

The status 400 response you get is due to a SuspiciousOperation exception being raised when your host header doesn't match any values in that list.

Spark specify multiple column conditions for dataframe join

Scala:

Leaddetails.join(
    Utm_Master, 
    Leaddetails("LeadSource") <=> Utm_Master("LeadSource")
        && Leaddetails("Utm_Source") <=> Utm_Master("Utm_Source")
        && Leaddetails("Utm_Medium") <=> Utm_Master("Utm_Medium")
        && Leaddetails("Utm_Campaign") <=> Utm_Master("Utm_Campaign"),
    "left"
)

To make it case insensitive,

import org.apache.spark.sql.functions.{lower, upper}

then just use lower(value) in the condition of the join method.

Eg: dataFrame.filter(lower(dataFrame.col("vendor")).equalTo("fortinet"))

Which port we can use to run IIS other than 80?

Also remember, when running on alternate ports, you need to specify the port on the URL:

http://www.example.com:8080

There may be firewalls or proxy servers to consider depending on your environment.

How do I get an Excel range using row and column numbers in VSTO / C#?

Facing the same problem I found the quickest solution was to actually scan the rows of the cells I wished to sort, determine the last row with a non-blank element and then select and sort on that grouping.

    Dim lastrow As Integer
lastrow = 0
For r = 3 To 120
   If Cells(r, 2) = "" Then
        Dim rng As Range
        Set rng = Range(Cells(3, 2), Cells(r - 1, 2 + 6))
        rng.Select
        rng.Sort Key1:=Range("h3"), order1:=xlDescending, Header:=xlGuess, DataOption1:=xlSortNormal
        r = 205
    End If
Next r

Convert Unix timestamp to a date string

This solution works with versions of date which do not support date -d @. It does not require AWK or other commands. A Unix timestamp is the number of seconds since Jan 1, 1970, UTC so it is important to specify UTC.

date -d '1970-01-01 1357004952 sec UTC'
Mon Dec 31 17:49:12 PST 2012

If you are on a Mac, then use:

date -r 1357004952

Command for getting epoch:

date +%s
1357004952

Credit goes to Anton: BASH: Convert Unix Timestamp to a Date

What are best practices for REST nested resources?

Rails provides a solution to this: shallow nesting.

I think this is a good because when you deal directly with a known resource, there's no need to use nested routes, as has been discussed in other answers here.

On delete cascade with doctrine2

There are two kinds of cascades in Doctrine:

1) ORM level - uses cascade={"remove"} in the association - this is a calculation that is done in the UnitOfWork and does not affect the database structure. When you remove an object, the UnitOfWork will iterate over all objects in the association and remove them.

2) Database level - uses onDelete="CASCADE" on the association's joinColumn - this will add On Delete Cascade to the foreign key column in the database:

@ORM\JoinColumn(name="father_id", referencedColumnName="id", onDelete="CASCADE")

I also want to point out that the way you have your cascade={"remove"} right now, if you delete a Child object, this cascade will remove the Parent object. Clearly not what you want.

How can I set a proxy server for gem?

You need to write this in the command prompt:

set HTTP_PROXY=http://your_proxy:your_port

Sort ObservableCollection<string> through C#

This is an ObservableCollection<T>, that automatically sorts itself upon a change, triggers a sort only when necessary, and only triggers a single move collection change action.

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Linq;

namespace ConsoleApp4
{
  using static Console;

  public class SortableObservableCollection<T> : ObservableCollection<T>
  {
    public Func<T, object> SortingSelector { get; set; }
    public bool Descending { get; set; }
    protected override void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
    {
      base.OnCollectionChanged(e);
      if (SortingSelector == null 
          || e.Action == NotifyCollectionChangedAction.Remove
          || e.Action == NotifyCollectionChangedAction.Reset)
        return;

      var query = this
        .Select((item, index) => (Item: item, Index: index));
      query = Descending
        ? query.OrderBy(tuple => SortingSelector(tuple.Item))
        : query.OrderByDescending(tuple => SortingSelector(tuple.Item));

      var map = query.Select((tuple, index) => (OldIndex:tuple.Index, NewIndex:index))
       .Where(o => o.OldIndex != o.NewIndex);

      using (var enumerator = map.GetEnumerator())
       if (enumerator.MoveNext())
          Move(enumerator.Current.OldIndex, enumerator.Current.NewIndex);


    }
  }


  //USAGE
  class Program
  {
    static void Main(string[] args)
    {
      var xx = new SortableObservableCollection<int>() { SortingSelector = i => i };
      xx.CollectionChanged += (sender, e) =>
       WriteLine($"action: {e.Action}, oldIndex:{e.OldStartingIndex},"
         + " newIndex:{e.NewStartingIndex}, newValue: {xx[e.NewStartingIndex]}");

      xx.Add(10);
      xx.Add(8);
      xx.Add(45);
      xx.Add(0);
      xx.Add(100);
      xx.Add(-800);
      xx.Add(4857);
      xx.Add(-1);

      foreach (var item in xx)
        Write($"{item}, ");
    }
  }
}

Output:

action: Add, oldIndex:-1, newIndex:0, newValue: 10
action: Add, oldIndex:-1, newIndex:1, newValue: 8
action: Move, oldIndex:1, newIndex:0, newValue: 8
action: Add, oldIndex:-1, newIndex:2, newValue: 45
action: Add, oldIndex:-1, newIndex:3, newValue: 0
action: Move, oldIndex:3, newIndex:0, newValue: 0
action: Add, oldIndex:-1, newIndex:4, newValue: 100
action: Add, oldIndex:-1, newIndex:5, newValue: -800
action: Move, oldIndex:5, newIndex:0, newValue: -800
action: Add, oldIndex:-1, newIndex:6, newValue: 4857
action: Add, oldIndex:-1, newIndex:7, newValue: -1
action: Move, oldIndex:7, newIndex:1, newValue: -1
-800, -1, 0, 8, 10, 45, 100, 4857,

jQuery Ajax calls and the Html.AntiForgeryToken()

found this very clever idea from https://gist.github.com/scottrippey/3428114 for every $.ajax calls it modifies the request and add the token.

// Setup CSRF safety for AJAX:
$.ajaxPrefilter(function(options, originalOptions, jqXHR) {
    if (options.type.toUpperCase() === "POST") {
        // We need to add the verificationToken to all POSTs
        var token = $("input[name^=__RequestVerificationToken]").first();
        if (!token.length) return;

        var tokenName = token.attr("name");

        // If the data is JSON, then we need to put the token in the QueryString:
        if (options.contentType.indexOf('application/json') === 0) {
            // Add the token to the URL, because we can't add it to the JSON data:
            options.url += ((options.url.indexOf("?") === -1) ? "?" : "&") + token.serialize();
        } else if (typeof options.data === 'string' && options.data.indexOf(tokenName) === -1) {
            // Append to the data string:
            options.data += (options.data ? "&" : "") + token.serialize();
        }
    }
});

The program can't start because MSVCR110.dll is missing from your computer

I was getting a similar issue from the Apache Lounge 32 bit version. After downloading the 64 bit version, the issue was resolved.

Here is an excellent video explain the steps involved: https://www.youtube.com/watch?v=17qhikHv5hY

Python lookup hostname from IP with 1 second timeout

>>> import socket
>>> socket.gethostbyaddr("69.59.196.211")
('stackoverflow.com', ['211.196.59.69.in-addr.arpa'], ['69.59.196.211'])

For implementing the timeout on the function, this stackoverflow thread has answers on that.

Size of Matrix OpenCV

For 2D matrix:

mat.rows – Number of rows in a 2D array.

mat.cols – Number of columns in a 2D array.

Or: C++: Size Mat::size() const

The method returns a matrix size: Size(cols, rows) . When the matrix is more than 2-dimensional, the returned size is (-1, -1).

For multidimensional matrix, you need to use

int thisSizes[3] = {2, 3, 4};
cv::Mat mat3D(3, thisSizes, CV_32FC1);
// mat3D.size tells the size of the matrix 
// mat3D.size[0] = 2;
// mat3D.size[1] = 3;
// mat3D.size[2] = 4;

Note, here 2 for z axis, 3 for y axis, 4 for x axis. By x, y, z, it means the order of the dimensions. x index changes the fastest.

Correct way to write line to file?

The python docs recommend this way:

with open('file_to_write', 'w') as f:
    f.write('file contents\n')

So this is the way I usually do it :)

Statement from docs.python.org:

It is good practice to use the 'with' keyword when dealing with file objects. This has the advantage that the file is properly closed after its suite finishes, even if an exception is raised on the way. It is also much shorter than writing equivalent try-finally blocks.

Debug vs Release in CMake

Instead of manipulating the CMAKE_CXX_FLAGS strings directly (which could be done more nicely using string(APPEND CMAKE_CXX_FLAGS_DEBUG " -g3") btw), you can use add_compiler_options:

add_compile_options(
  "-Wall" "-Wpedantic" "-Wextra" "-fexceptions"
  "$<$<CONFIG:DEBUG>:-O0;-g3;-ggdb>"
)

This would add the specified warnings to all build types, but only the given debugging flags to the DEBUG build. Note that compile options are stored as a CMake list, which is just a string separating its elements by semicolons ;.

Get width/height of SVG element

This is the consistent cross-browser way I found:

var heightComponents = ['height', 'paddingTop', 'paddingBottom', 'borderTopWidth', 'borderBottomWidth'],
    widthComponents = ['width', 'paddingLeft', 'paddingRight', 'borderLeftWidth', 'borderRightWidth'];

var svgCalculateSize = function (el) {

    var gCS = window.getComputedStyle(el), // using gCS because IE8- has no support for svg anyway
        bounds = {
            width: 0,
            height: 0
        };

    heightComponents.forEach(function (css) { 
        bounds.height += parseFloat(gCS[css]);
    });
    widthComponents.forEach(function (css) {
        bounds.width += parseFloat(gCS[css]);
    });
    return bounds;
};

SecurityError: The operation is insecure - window.history.pushState()

I had this problem on ReactJS history push, turned out i was trying to open //link (with double slashes)

Comment shortcut Android Studio

In spanish keyboard without changing anything I can make a comment with the keys:

cmd + -

OR

cmd + alt + -

This works because in english keyboard / is located at the same place than - on a spanish keyboard

What does "var" mean in C#?

  • As the name suggested, var is variable without any data type.
  • If you don't know which type of data will be returned by any method, such cases are good for using var.
  • var is Implicit type which means system will define the data type itself. The compiler will infer its type based on the value to the right of the "=" operator.
  • int/string etc. are the explicit types as it is defined by you explicitly.
  • Var can only be defined in a method as a local variable
  • Multiple vars cannot be declared and initialized in a single statement. For example, var i=1, j=2; is invalid.
int i = 100;// explicitly typed 
var j = 100; // implicitly typed

How to load image to WPF in runtime?

In WPF an image is typically loaded from a Stream or an Uri.

BitmapImage supports both and an Uri can even be passed as constructor argument:

var uri = new Uri("http://...");
var bitmap = new BitmapImage(uri);

If the image file is located in a local folder, you would have to use a file:// Uri. You could create such a Uri from a path like this:

var path = Path.Combine(Environment.CurrentDirectory, "Bilder", "sas.png");
var uri = new Uri(path);

If the image file is an assembly resource, the Uri must follow the the Pack Uri scheme:

var uri = new Uri("pack://application:,,,/Bilder/sas.png");

In this case the Visual Studio Build Action for sas.png would have to be Resource.

Once you have created a BitmapImage and also have an Image control like in this XAML

<Image Name="image1" />

you would simply assign the BitmapImage to the Source property of that Image control:

image1.Source = bitmap;

How to change app default theme to a different app theme?

Actually you should define your styles in res/values/styles.xml. I guess now you've got the following configuration:

<style name="AppBaseTheme" parent="android:Theme.Holo.Light"/>
<style name="AppTheme" parent="AppBaseTheme"/>

so if you want to use Theme.Black then change AppBaseTheme parent to android:Theme.Black or you could change app style directly in manifest file like this - android:theme="@android:style/Theme.Black". You must be lacking android namespace before style tag.

You can read more about styles and themes here.

Get img src with PHP

Use a HTML parser like DOMDocument and then evaluate the value you're looking for with DOMXpath:

$html = '<img id="12" border="0" src="/images/image.jpg"
         alt="Image" width="100" height="100" />';

$doc = new DOMDocument();
$doc->loadHTML($html);
$xpath = new DOMXPath($doc);
$src = $xpath->evaluate("string(//img/@src)"); # "/images/image.jpg"

Or for those who really need to save space:

$xpath = new DOMXPath(@DOMDocument::loadHTML($html));
$src = $xpath->evaluate("string(//img/@src)");

And for the one-liners out there:

$src = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($html))->xpath("//img/@src"));

Ubuntu - Run command on start-up with "sudo"

Edit the tty configuration in /etc/init/tty*.conf with a shellscript as a parameter :

(...)
exec /sbin/getty -n -l  theInputScript.sh -8 38400 tty1
(...)

This is assuming that we're editing tty1 and the script that reads input is theInputScript.sh.

A word of warning this script is run as root, so when you are inputing stuff to it you have root priviliges. Also append a path to the location of the script.

Important: the script when it finishes, has to invoke the /sbin/login otherwise you wont be able to login in the terminal.

Address in mailbox given [] does not comply with RFC 2822, 3.6.2. when email is in a variable

Your problem may be that the .env file is not loading properly and using the MAIL_USERNAME.

To check if your .env file is loading the email address properly add this line to your controller and refresh the page.

dd(env('MAIL_USERNAME') 

If it shows up null try running the following command from command line and trying again.

php artisan cache:clear

Rounded corner for textview in android

You can use the provided rectangle shape (without a gradient, unless you want one) as follows:

In drawable/rounded_rectangle.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <corners android:radius="5dp" />
    <stroke android:width="1dp" android:color="#ff0000" />
    <solid android:color="#00ff00" />
</shape>

Then in your text view:

android:background="@drawable/rounded_rectangle"

Of course, you will want to customize the dimensions and colors.

How to override maven property in command line?

See Introduction to the POM

finalName is created as:

<build>
    <finalName>${project.artifactId}-${project.version}</finalName>
</build>

One of the solutions is to add own property:

<properties>
    <finalName>${project.artifactId}-${project.version}</finalName>
</properties>
<build>
    <finalName>${finalName}</finalName>
 </build>

And now try:

mvn -DfinalName=build clean package

An attempt was made to access a socket in a way forbidden by its access permissions

My situation and solution: I had created and enabled a HyperV ethernet adapter. For some reason, my main windows machine was using the "virtual" ethernet adapter instead of the 'hardware' adapter.

I disabled the virtual ethernet and my network settings to change the network public/privacy settings were revealed.

Difference between VARCHAR and TEXT in MySQL

TL;DR

TEXT

  • fixed max size of 65535 characters (you cannot limit the max size)
  • takes 2 + c bytes of disk space, where c is the length of the stored string.
  • cannot be (fully) part of an index. One would need to specify a prefix length.

VARCHAR(M)

  • variable max size of M characters
  • M needs to be between 1 and 65535
  • takes 1 + c bytes (for M ≤ 255) or 2 + c (for 256 ≤ M ≤ 65535) bytes of disk space where c is the length of the stored string
  • can be part of an index

More Details

TEXT has a fixed max size of 2¹6-1 = 65535 characters.
VARCHAR has a variable max size M up to M = 2¹6-1.
So you cannot choose the size of TEXT but you can for a VARCHAR.

The other difference is, that you cannot put an index (except for a fulltext index) on a TEXT column.
So if you want to have an index on the column, you have to use VARCHAR. But notice that the length of an index is also limited, so if your VARCHAR column is too long you have to use only the first few characters of the VARCHAR column in your index (See the documentation for CREATE INDEX).

But you also want to use VARCHAR, if you know that the maximum length of the possible input string is only M, e.g. a phone number or a name or something like this. Then you can use VARCHAR(30) instead of TINYTEXT or TEXT and if someone tries to save the text of all three "Lord of the Ring" books in your phone number column you only store the first 30 characters :)

Edit: If the text you want to store in the database is longer than 65535 characters, you have to choose MEDIUMTEXT or LONGTEXT, but be careful: MEDIUMTEXT stores strings up to 16 MB, LONGTEXT up to 4 GB. If you use LONGTEXT and get the data via PHP (at least if you use mysqli without store_result), you maybe get a memory allocation error, because PHP tries to allocate 4 GB of memory to be sure the whole string can be buffered. This maybe also happens in other languages than PHP.

However, you should always check the input (Is it too long? Does it contain strange code?) before storing it in the database.

Notice: For both types, the required disk space depends only on the length of the stored string and not on the maximum length.
E.g. if you use the charset latin1 and store the text "Test" in VARCHAR(30), VARCHAR(100) and TINYTEXT, it always requires 5 bytes (1 byte to store the length of the string and 1 byte for each character). If you store the same text in a VARCHAR(2000) or a TEXT column, it would also require the same space, but, in this case, it would be 6 bytes (2 bytes to store the string length and 1 byte for each character).

For more information have a look at the documentation.

Finally, I want to add a notice, that both, TEXT and VARCHAR are variable length data types, and so they most likely minimize the space you need to store the data. But this comes with a trade-off for performance. If you need better performance, you have to use a fixed length type like CHAR. You can read more about this here.

Do Swift-based applications work on OS X 10.9/iOS 7 and lower?

Swift applications are supported on iOS 7 and above as stated in Beta 4 release notes. iOS 6.0, 6.1, 7.0, 7.1, 8.0 in Xcode 6 Beta

Swift applications are supported on platforms OS X 10.9 and above. OS X 10.4 to 10.10 in Deployment Target. I have tested on targeting 10.5 to 10.10, and running on 10.9.3

How to completely uninstall python 2.7.13 on Ubuntu 16.04

Sometimes you need to first update the apt repo list.

sudo apt-get update
sudo apt purge python2.7-minimal

What is android:weightSum in android, and how does it work?

If unspecified, the sum is computed by adding the layout_weight of all of the children. This can be used for instance to give a single child 50% of the total available space by giving it a layout_weight of 0.5 and setting the weightSum to 1.0. Must be a floating point value, such as "1.2"

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/main_rel"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal"
        android:weightSum="2.0" >

        <RelativeLayout
            android:id="@+id/child_one"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1.0"
            android:background="#0000FF" >
        </RelativeLayout>

        <RelativeLayout
            android:id="@+id/child_two"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1.0"
            android:background="#00FF00" >
        </RelativeLayout>

    </LinearLayout>

Clear and refresh jQuery Chosen dropdown list

If in case trigger("chosen:updated"); doesn't works for you. You can try $('#ddl').trigger('change'); as in my case its work for me.

How to download a file via FTP with Python ftplib

A = filename

ftp = ftplib.FTP("IP")
ftp.login("USR Name", "Pass")
ftp.cwd("/Dir")


try:
    ftp.retrbinary("RETR " + filename ,open(A, 'wb').write)
except:
    print "Error"

Possible to restore a backup of SQL Server 2014 on SQL Server 2012?

Sure it's possible... use Export Wizard in source option use SQL SERVER NATIVE CLIENT 11, later your source server ex.192.168.100.65\SQLEXPRESS next step select your new destination server ex.192.168.100.65\SQL2014

Just be sure to be using correct instance and connect each other

Just pay attention in Stored procs must be recompiled

GitHub: How to make a fork of public repository private?

The answers are correct but don't mention how to sync code between the public repo and the fork.

Here is the full workflow (we've done this before open sourcing React Native):


First, duplicate the repo as others said (details here):

Create a new repo (let's call it private-repo) via the Github UI. Then:

git clone --bare https://github.com/exampleuser/public-repo.git
cd public-repo.git
git push --mirror https://github.com/yourname/private-repo.git
cd ..
rm -rf public-repo.git

Clone the private repo so you can work on it:

git clone https://github.com/yourname/private-repo.git
cd private-repo
make some changes
git commit
git push origin master

To pull new hotness from the public repo:

cd private-repo
git remote add public https://github.com/exampleuser/public-repo.git
git pull public master # Creates a merge commit
git push origin master

Awesome, your private repo now has the latest code from the public repo plus your changes.


Finally, to create a pull request private repo -> public repo:

Use the GitHub UI to create a fork of the public repo (the small "Fork" button at the top right of the public repo page). Then:

git clone https://github.com/yourname/the-fork.git
cd the-fork
git remote add private_repo_yourname https://github.com/yourname/private-repo.git
git checkout -b pull_request_yourname
git pull private_repo_yourname master
git push origin pull_request_yourname

Now you can create a pull request via the Github UI for public-repo, as described here.

Once project owners review your pull request, they can merge it.

Of course the whole process can be repeated (just leave out the steps where you add remotes).

Should Jquery code go in header or footer?

Nimbuz provides a very good explanation of the issue involved, but I think the final answer depends on your page: what's more important for the user to have sooner - scripts or images?

There are some pages that don't make sense without the images, but only have minor, non-essential scripting. In that case it makes sense to put scripts at the bottom, so the user can see the images sooner and start making sense of the page. Other pages rely on scripting to work. In that case it's better to have a working page without images than a non-working page with images, so it makes sense to put scripts at the top.

Another thing to consider is that scripts are typically smaller than images. Of course, this is a generalisation and you have to see whether it applies to your page. If it does then that, to me, is an argument for putting them first as a rule of thumb (ie. unless there's a good reason to do otherwise), because they won't delay images as much as images would delay the scripts. Finally, it's just much easier to have script at the top, because you don't have to worry about whether they're loaded yet when you need to use them.

In summary, I tend to put scripts at the top by default and only consider whether it's worthwhile moving them to the bottom after the page is complete. It's an optimisation - and I don't want to do it prematurely.

Ajax LARAVEL 419 POST error

419 error happens when you don`t post csrf_token. in your post method you must add this token along other variables.

xpath find if node exists

I work in Ruby and using Nokogiri I fetch the element and look to see if the result is nil.

require 'nokogiri'

url = "http://somthing.com/resource"

resp = Nokogiri::XML(open(url))

first_name = resp.xpath("/movies/actors/actor[1]/first-name")

puts "first-name not found" if first_name.nil?

Presenting a UIAlertController properly on an iPad using iOS 8

For me I just needed to add the following:

if let popoverController = alertController.popoverPresentationController {
    popoverController.barButtonItem = navigationItem.rightBarButtonItem
}

Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user 'root'@'localhost'(using password:YES)

Go to the search bar on your Windows and search for Services. Launch Services and look for MySQLxx (xx depends on your MySQL version) in the long list of services. Right-click on MySQLxx and hit Start. MySQL should work fine now.

What does "static" mean in C?

Short answer ... it depends.

  1. Static defined local variables do not lose their value between function calls. In other words they are global variables, but scoped to the local function they are defined in.

  2. Static global variables are not visible outside of the C file they are defined in.

  3. Static functions are not visible outside of the C file they are defined in.

How to increase Heap size of JVM

Use -Xms1024m -Xmx1024m to control your heap size (1024m is only for demonstration, the exact number depends your system memory). Setting minimum and maximum heap size to the same is usually a best practice since JVM doesn't have to increase heap size at runtime.

Summernote image upload

Summernote converts your uploaded images to a base64 encoded string by default, you can process this string or as other fellows mentioned you can upload images using onImageUpload callback. You can take a look at this gist which I modified a bit to adapt laravel csrf token here. But that did not work for me and I had no time to find out why! Instead, I solved it via a server-side solution based on this blog post. It gets the output of the summernote and then it will upload the images and updates the final markdown HTML.

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;

Route::get('/your-route-to-editor', function () {
    return view('your-view');
});

Route::post('/your-route-to-processor', function (Request $request) {

       $this->validate($request, [
           'editordata' => 'required',
       ]);

       $data = $request->input('editordata');

       //loading the html data from the summernote editor and select the img tags from it
       $dom = new \DomDocument();
       $dom->loadHtml($data, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);    
       $images = $dom->getElementsByTagName('img');
       
       foreach($images as $k => $img){
           //for now src attribute contains image encrypted data in a nonsence string
           $data = $img->getAttribute('src');
           //getting the original file name that is in data-filename attribute of img
           $file_name = $img->getAttribute('data-filename');
           //extracting the original file name and extension
           $arr = explode('.', $file_name);
           $upload_base_directory = 'public/';

           $original_file_name='time()'.$k;
           $original_file_extension='png';

           if (sizeof($arr) ==  2) {
                $original_file_name = $arr[0];
                $original_file_extension = $arr[1];
           }
           else
           {
                //the file name contains extra . in itself
                $original_file_name = implode("_",array_slice($arr,0,sizeof($arr)-1));
                $original_file_extension = $arr[sizeof($arr)-1];
           }

           list($type, $data) = explode(';', $data);
           list(, $data)      = explode(',', $data);

           $data = base64_decode($data);

           $path = $upload_base_directory.$original_file_name.'.'.$original_file_extension;

           //uploading the image to an actual file on the server and get the url to it to update the src attribute of images
           Storage::put($path, $data);

           $img->removeAttribute('src');       
           //you can remove the data-filename attribute here too if you want.
           $img->setAttribute('src', Storage::url($path));
           // data base stuff here :
           //saving the attachments path in an array
       }

       //updating the summernote WYSIWYG markdown output.
       $data = $dom->saveHTML();

       // data base stuff here :
       // save the post along with it attachments array
       return view('your-preview-page')->with(['data'=>$data]);

});

"Parse Error : There is a problem parsing the package" while installing Android application

I've only seen the parsing error when the android version on the device was lower than the version the app was compiled for. For example if the app is compiled for android OS v2.2 and your device only has android OS v2.1 you'd get a parse error when you try to install the app.

How to toggle a boolean?

I was searching after a toggling method that does the same, except for an inital value of null or undefined, where it should become false.

Here it is:

booly = !(booly != false)

Remove element of a regular array

LINQ one-line solution:

myArray = myArray.Where((source, index) => index != 1).ToArray();

The 1 in that example is the index of the element to remove -- in this example, per the original question, the 2nd element (with 1 being the second element in C# zero-based array indexing).

A more complete example:

string[] myArray = { "a", "b", "c", "d", "e" };
int indexToRemove = 1;
myArray = myArray.Where((source, index) => index != indexToRemove).ToArray();

After running that snippet, the value of myArray will be { "a", "c", "d", "e" }.

Installing MySQL in Docker fails with error message "Can't connect to local MySQL server through socket"

Check out what's in your database.yml file. If you already have your plain Rails app and simply wrapping it with Docker, you should change (inside database.yml):

socket: /var/run/mysqld/mysqld.sock #just comment it out

to

host: db 

where db is the name of my db-service from docker-compose.yml. And here's my docker-compose.yml:

version: '3'
services:
  web:
    build: .
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - .:/myapp
    ports:
      - "3000:3000"
    links:
      - db
  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: root

You start your app in console (in app folder) as docker-compose up. Then WAIT 1 MINUTE (let your mysql service to completely load) until some new logs stop appearing in console. Usually the last line should be like

db_1 | 2017-12-24T12:25:20.397174Z 0 [Note] End of list of non-natively partitioned tables

Then (in a new terminal window) apply:

docker-compose run web rake db:create

and then

docker-compose run web rake db:migrate

After you finish your work stop the loaded images with

docker-compose stop

Don't use docker-compose down here instead because if you do, you will erase your database content.

Next time when you want to resume your work apply:

docker-compose start

The rest of the things do exactly as explained here: https://docs.docker.com/compose/rails/

Valid content-type for XML, HTML and XHTML documents

HTML: text/html, full-stop.

XHTML: application/xhtml+xml, or only if following HTML compatbility guidelines, text/html. See the W3 Media Types Note.

XML: text/xml, application/xml (RFC 2376).

There are also many other media types based around XML, for example application/rss+xml or image/svg+xml. It's a safe bet that any unrecognised but registered ending in +xml is XML-based. See the IANA list for registered media types ending in +xml.

(For unregistered x- types, all bets are off, but you'd hope +xml would be respected.)

Asynchronous vs synchronous execution, what does it really mean?

In regards to the "at the same time" definition of synchronous execution (which is sometimes confusing), here's a good way to understand it:

Synchronous Execution: All tasks within a block of code are all executed at the same time.

Asynchronous Execution: All tasks within a block of code are not all executed at the same time.

XAMPP PORT 80 is Busy / EasyPHP error in Apache configuration file:

Things to be done to free port 80:

  1. check if skype is running, exit from skype
  2. check services.msc if web deployment agent service is running
  3. check if IIS is running, stop it.

Once you start apache, you can sign into skype.

how to use math.pi in java

Replace

volume = (4 / 3) Math.PI * Math.pow(radius, 3);

With:

volume = (4 * Math.PI * Math.pow(radius, 3)) / 3;

Command /Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1

My problem was that under Build Phases -> Compile Sources, I added a compiler flag for a file, but I had misspelled it. It was supposed to be:

-fno-obj-arc

to show that this file does not use ARC.

Convert an integer to a byte array

Check out the "encoding/binary" package. Particularly the Read and Write functions:

binary.Write(a, binary.LittleEndian, myInt)

Saving to CSV in Excel loses regional date format

If you use a Custom format, rather than one of the pre-selected Date formats, the export to CSV will keep your selected format. Otherwise it defaults back to the US format

How to know Hive and Hadoop versions from command prompt?

We can find hive version by

  • on linux shell : "hive --version"
  • on hive shell : " ! hive --version;"

above cmds works on hive 0.13 and above.

Set system:sun.java.command;
gives the hive version from hue hive editor it gives the the jar name which includes the version.

New lines (\r\n) are not working in email body

OP's problem was related with HTML coding. But if you are using plain text, please use "\n" and not "\r\n".

My personal use case: using mailx mailer, simply replacing "\r\n" into "\n" fixed my issue, related with wrong automatic Content-Type setting.

Wrong header:

User-Agent: Heirloom mailx 12.4 7/29/08
MIME-Version: 1.0
Content-Type: application/octet-stream
Content-Transfer-Encoding: base64

Correct header:

User-Agent: Heirloom mailx 12.4 7/29/08
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

I'm not saying that "application/octet-stream" and "base64" are always wrong/unwanted, but they where in my case.

Find out if string ends with another string in C++

Note, that starting from c++20 std::string will finally provide starts_with and ends_with. Seems like there is a chance that by c++30 strings in c++ might finally become usable, if you aren't reading this from distant future, you can use these startsWith/endsWith with C++17:

#if __cplusplus >= 201703L // C++17 and later 
#include <string_view>

static bool endsWith(std::string_view str, std::string_view suffix)
{
    return str.size() >= suffix.size() && 0 == str.compare(str.size()-suffix.size(), suffix.size(), suffix);
}

static bool startsWith(std::string_view str, std::string_view prefix)
{
    return str.size() >= prefix.size() && 0 == str.compare(0, prefix.size(), prefix);
}
#endif // C++17

If you are stuck with older C++, you may use these:

#if __cplusplus < 201703L // pre C++17
#include <string>

static bool endsWith(const std::string& str, const std::string& suffix)
{
    return str.size() >= suffix.size() && 0 == str.compare(str.size()-suffix.size(), suffix.size(), suffix);
}

static bool startsWith(const std::string& str, const std::string& prefix)
{
    return str.size() >= prefix.size() && 0 == str.compare(0, prefix.size(), prefix);
}

and some extra helper overloads:

static bool endsWith(const std::string& str, const char* suffix, unsigned suffixLen)
{
    return str.size() >= suffixLen && 0 == str.compare(str.size()-suffixLen, suffixLen, suffix, suffixLen);
}

static bool endsWith(const std::string& str, const char* suffix)
{
    return endsWith(str, suffix, std::string::traits_type::length(suffix));
}

static bool startsWith(const std::string& str, const char* prefix, unsigned prefixLen)
{
    return str.size() >= prefixLen && 0 == str.compare(0, prefixLen, prefix, prefixLen);
}

static bool startsWith(const std::string& str, const char* prefix)
{
    return startsWith(str, prefix, std::string::traits_type::length(prefix));
}
#endif

IMO, c++ strings are clearly dysfunctional, and weren't made to be used in real world code. But there is a hope that this will get better at least.

Trying to make bootstrap modal wider

Always have handy the un-minified CSS for bootstrap so you can see what styles they have on their components, then create a CSS file AFTER it, if you don't use LESS and over-write their mixins or whatever

This is the default modal css for 768px and up:

@media (min-width: 768px) {
  .modal-dialog {
    width: 600px;
    margin: 30px auto;
  }
  ...
}

They have a class modal-lg for larger widths

@media (min-width: 992px) {
  .modal-lg {
    width: 900px;
  }
}

If you need something twice the 600px size, and something fluid, do something like this in your CSS after the Bootstrap css and assign that class to the modal-dialog.

@media (min-width: 768px) {
  .modal-xl {
    width: 90%;
   max-width:1200px;
  }
}

HTML

<div class="modal-dialog modal-xl">

Demo: http://jsbin.com/yefas/1

bash: mkvirtualenv: command not found

Solved my issue in Ubuntu 14.04 OS with python 2.7.6, by adding below two lines into ~/.bash_profile (or ~/.bashrc in unix) files.

source "/usr/local/bin/virtualenvwrapper.sh"

export WORKON_HOME="/opt/virtual_env/"

And then executing both these lines onto the terminal.

What are the benefits of learning Vim?

It's definitely worth the effort.

There's one obvious reason that anyone who uses Vi(m) will tell you, and two others that people never seem to mention.

Here's the obvious one:

  1. vi is at once ubiquitous and incredibly powerful, and by learning it once, you gain the ability to exercise that power on pretty much any computer that has a keyboard.

And these are the lesser known reasons to learn Vim:

  1. It's not half as much effort as you think it's going to be. Run through the Vim tutor once (vimtutor at a shell, or in Windows run it from the Vim folder in the Start Menu), and you'll already be well on your way to competence, and it's all downhill from there. I was up to the level where I could use Vim at work without taking any noticeable productivity hit within less than a week's worth of lunchtimes.

  2. It's fun! Editing text is like a game to me now. I actively enjoy it--which is pretty ridiculous, when you think about it.

There's also two good reasons not to learn Vim:

  1. It's addictive, and you'll find yourself wishing you could use Vim commands in all your computing, and cursing whenever you can't. Fortunately, at least for some situations, there's ways to get around this.

  2. Again, it's addictive, and although you won't lose any productivity from actually using Vim, you will waste hours searching for good tips to make your Vim experience even better, and reading the Vim tag on Stack Overflow.

How do you test a public/private DSA keypair?

If you are in Windows and want use a GUI, with puttygen you can import your private key into it:

enter image description here

Once imported, you can save its public key and compare it to yours.

Why doesn't logcat show anything in my Android?

In case if you are using cynogenmod in your mobile it will disable logging by default, try this method:

In your device, open "/system/etc/init.d/" folder If there are many files, try opening each file and find for this line:

rm /dev/log/main

Now, comment this line like this: # rm /dev/log/main

save the file and reboot.

Difference between JSONObject and JSONArray

Best programmatically Understanding.

when syntax is {}then this is JsonObject

when syntax is [] then this is JsonArray

A JSONObject is a JSON-like object that can be represented as an element in the JSONArray. JSONArray can contain a (or many) JSONObject

Hope this will helpful to you !

How to sort by two fields in Java?

Arrays.sort(persons, new PersonComparator());



import java.util.Comparator;

public class PersonComparator implements Comparator<? extends Person> {

    @Override
    public int compare(Person o1, Person o2) {
        if(null == o1 || null == o2  || null == o1.getName() || null== o2.getName() ){
            throw new NullPointerException();
        }else{
            int nameComparisonResult = o1.getName().compareTo(o2.getName());
            if(0 == nameComparisonResult){
                return o1.getAge()-o2.getAge();
            }else{
                return nameComparisonResult;
            }
        }
    }
}


class Person{
    int age; String name;

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

Updated version:

public class PersonComparator implements Comparator<? extends Person> {

   @Override
   public int compare(Person o1, Person o2) {

      int nameComparisonResult = o1.getName().compareToIgnoreCase(o2.getName());
      return 0 == nameComparisonResult?o1.getAge()-o2.getAge():nameComparisonResult;

   }
 }

Firefox setting to enable cross domain Ajax request

I'm facing this from file://. I'd like to send queries to two servers from a local HTML file (a testbed).

This particular case should not be any safety concern, but only Safari allows this.

Here is the best discussion I've found of the issue.

How to save local data in a Swift app?

Swift 5+

None of the answers really cover in detail the default built in local storage capabilities. It can do far more than just strings.

You have the following options straight from the apple documentation for 'getting' data from the defaults.

func object(forKey: String) -> Any?
//Returns the object associated with the specified key.

func url(forKey: String) -> URL?
//Returns the URL associated with the specified key.

func array(forKey: String) -> [Any]?
//Returns the array associated with the specified key.

func dictionary(forKey: String) -> [String : Any]?
//Returns the dictionary object associated with the specified key.

func string(forKey: String) -> String?
//Returns the string associated with the specified key.

func stringArray(forKey: String) -> [String]?
//Returns the array of strings associated with the specified key.

func data(forKey: String) -> Data?
//Returns the data object associated with the specified key.

func bool(forKey: String) -> Bool
//Returns the Boolean value associated with the specified key.

func integer(forKey: String) -> Int
//Returns the integer value associated with the specified key.

func float(forKey: String) -> Float
//Returns the float value associated with the specified key.

func double(forKey: String) -> Double
//Returns the double value associated with the specified key.

func dictionaryRepresentation() -> [String : Any]
//Returns a dictionary that contains a union of all key-value pairs in the domains in the search list.

Here are the options for 'setting'

func set(Any?, forKey: String)
//Sets the value of the specified default key.

func set(Float, forKey: String)
//Sets the value of the specified default key to the specified float value.

func set(Double, forKey: String)
//Sets the value of the specified default key to the double value.

func set(Int, forKey: String)
//Sets the value of the specified default key to the specified integer value.

func set(Bool, forKey: String)
//Sets the value of the specified default key to the specified Boolean value.

func set(URL?, forKey: String)
//Sets the value of the specified default key to the specified URL.

If are storing things like preferences and not a large data set these are perfectly fine options.

Double Example:

Setting:

let defaults = UserDefaults.standard
var someDouble:Double = 0.5
defaults.set(someDouble, forKey: "someDouble")

Getting:

let defaults = UserDefaults.standard
var someDouble:Double = 0.0
someDouble = defaults.double(forKey: "someDouble")

What is interesting about one of the getters is dictionaryRepresentation, this handy getter will take all your data types regardless what they are and put them into a nice dictionary that you can access by it's string name and give the correct corresponding data type when you ask for it back since it's of type 'any'.

You can store your own classes and objects also using the func set(Any?, forKey: String) and func object(forKey: String) -> Any? setter and getter accordingly.

Hope this clarifies more the power of the UserDefaults class for storing local data.

On the note of how much you should store and how often, Hardy_Germany gave a good answer on that on this post, here is a quote from it

As many already mentioned: I'm not aware of any SIZE limitation (except physical memory) to store data in a .plist (e.g. UserDefaults). So it's not a question of HOW MUCH.

The real question should be HOW OFTEN you write new / changed values... And this is related to the battery drain this writes will cause.

IOS has no chance to avoid a physical write to "disk" if a single value changed, just to keep data integrity. Regarding UserDefaults this cause the whole file rewritten to disk.

This powers up the "disk" and keep it powered up for a longer time and prevent IOS to go to low power state.

Something else to note as mentioned by user Mohammad Reza Farahani from this post is the asynchronous and synchronous nature of userDefaults.

When you set a default value, it’s changed synchronously within your process, and asynchronously to persistent storage and other processes.

For example if you save and quickly close the program you may notice it does not save the results, this is because it's persisting asynchronously. You might not notice this all the time so if you plan on saving before quitting the program you may want to account for this by giving it some time to finish.

Maybe someone has some nice solutions for this they can share in the comments?

How do I make a relative reference to another workbook in Excel?

Presume you linking to a shared drive for example the S drive? If so, other people may have mapped the drive differently. You probably need to use the "official" drive name //euhkj002/forecasts/bla bla. Instead of S// in your link

How to correctly write async method?

To get the behavior you want you need to wait for the process to finish before you exit Main(). To be able to tell when your process is done you need to return a Task instead of a void from your function, you should never return void from a async function unless you are working with events.

A re-written version of your program that works correctly would be

class Program {     static void Main(string[] args)     {         Debug.WriteLine("Calling DoDownload");         var downloadTask = DoDownloadAsync();         Debug.WriteLine("DoDownload done");         downloadTask.Wait(); //Waits for the background task to complete before finishing.      }      private static async Task DoDownloadAsync()     {         WebClient w = new WebClient();          string txt = await w.DownloadStringTaskAsync("http://www.google.com/");         Debug.WriteLine(txt);     } } 

Because you can not await in Main() I had to do the Wait() function instead. If this was a application that had a SynchronizationContext I would do await downloadTask; instead and make the function this was being called from async.

How to make VS Code to treat other file extensions as certain language?

I have followed a different approach to solve pretty much the same problem, in my case, I made a new extension that adds PHP syntax highlighting support for Drupal-specific files (such as .module and .inc): https://github.com/mastazi/VS-code-drupal

As you can see in the code, I created a new extension rather than modifying the existing PHP extension. Obviously I declare a dependency on the PHP extension in the Drupal extension.

The advantage of doing it this way is that if there is an update to the PHP extension, my custom support for Drupal doesn't get lost in the update process.

File Upload to HTTP server in iphone programming

I used ASIHTTPRequest a lot like Jane Sales answer but it is not under development anymore and the author suggests using other libraries like AFNetworking.

Honestly, I think now is the time to start looking elsewhere.

AFNetworking works great, and let you work with blocks a lot (which is a great relief).

Here's an image upload example from their documentation page on github:

NSURL *url = [NSURL URLWithString:@"http://api-base-url.com"];
AFHTTPClient *httpClient = [[AFHTTPClient alloc] initWithBaseURL:url];
NSData *imageData = UIImageJPEGRepresentation([UIImage imageNamed:@"avatar.jpg"], 0.5);
NSMutableURLRequest *request = [httpClient multipartFormRequestWithMethod:@"POST" path:@"/upload" parameters:nil constructingBodyWithBlock: ^(id <AFMultipartFormData>formData) {
    [formData appendPartWithFileData:imageData name:@"avatar" fileName:@"avatar.jpg" mimeType:@"image/jpeg"];
}];

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
[operation setUploadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {
    NSLog(@"Sent %lld of %lld bytes", totalBytesWritten, totalBytesExpectedToWrite);
}];
[httpClient enqueueHTTPRequestOperation:operation];

Passing references to pointers in C++

Your function expects a reference to an actual string pointer in the calling scope, not an anonymous string pointer. Thus:

string s;
string* _s = &s;
myfunc(_s);

should compile just fine.

However, this is only useful if you intend to modify the pointer you pass to the function. If you intend to modify the string itself you should use a reference to the string as Sake suggested. With that in mind it should be more obvious why the compiler complains about you original code. In your code the pointer is created 'on the fly', modifying that pointer would have no consequence and that is not what is intended. The idea of a reference (vs. a pointer) is that a reference always points to an actual object.

use video as background for div

Pure CSS method

It is possible to center a video inside an element just like a cover sized background-image without JS using the object-fit attribute or CSS Transforms.

2021 answer: object-fit

As pointed in the comments, it is possible to achieve the same result without CSS transform, but using object-fit, which I think it's an even better option for the same result:

_x000D_
_x000D_
.video-container {
    height: 300px;
    width: 300px;
    position: relative;
}

.video-container video {
  width: 100%;
  height: 100%;
  position: absolute;
  object-fit: cover;
  z-index: 0;
}

/* Just styling the content of the div, the *magic* in the previous rules */
.video-container .caption {
  z-index: 1;
  position: relative;
  text-align: center;
  color: #dc0000;
  padding: 10px;
}
_x000D_
<div class="video-container">
    <video autoplay muted loop>
        <source src="https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4" type="video/mp4" />
    </video>
    <div class="caption">
      <h2>Your caption here</h2>
    </div>
</div>
_x000D_
_x000D_
_x000D_


Previous answer: CSS Transform

You can set a video as a background to any HTML element easily thanks to transform CSS property.

Note that you can use the transform technique to center vertically and horizontally any HTML element.

_x000D_
_x000D_
.video-container {
  height: 300px;
  width: 300px;
  overflow: hidden;
  position: relative;
}

.video-container video {
  min-width: 100%;
  min-height: 100%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translateX(-50%) translateY(-50%);
}

/* Just styling the content of the div, the *magic* in the previous rules */
.video-container .caption {
  z-index: 1;
  position: relative;
  text-align: center;
  color: #dc0000;
  padding: 10px;
}
_x000D_
<div class="video-container">
  <video autoplay muted loop>
    <source src="https://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4" type="video/mp4" />
  </video>
  <div class="caption">
    <h2>Your caption here</h2>
  </div>
</div>
_x000D_
_x000D_
_x000D_

Set value of textbox using JQuery

Make sure you have the right selector, and then wait until the page is ready and that the element exists until you run the function.

$(function(){
    $('#searchBar').val('hi')
});

As Derek points out, the ID is wrong as well.

Change to $('#main_search')

Global Variable from a different file Python

global is a bit of a misnomer in Python, module_namespace would be more descriptive.

The fully qualified name of foo is file1.foo and the global statement is best shunned as there are usually better ways to accomplish what you want to do. (I can't tell what you want to do from your toy example.)

Validating a Textbox field for only numeric input.

I know this is an old question but I figured out I should pitch my answer anyways.

The following snippet iterates through each character of the text and uses the IsNumber() method, which returns true if the character is a number and false the other way, to check if all the characters are numbers. If all are numbers, the method returns true. If not it returns false.

using System;

private bool ValidateText(string text){
    char[] characters = text.ToCharArray();

    foreach(char c in characters){
        if(!char.IsNumber(c))
            return false;
    }
    return true;
}

Is there a way to specify a max height or width for an image?

set a style for the image

<asp:Image ID="Image1" runat="server" style="max-height:1000px;max-width:900px;height:auto;width:auto;" />

Transparent CSS background color

Try this:

opacity:0;

For IE8 and earlier

filter:Alpha(opacity=0); 

Opacity Demo from W3Schools

What's the "Content-Length" field in HTTP header?

rfc2616

The Content-Length entity-header field indicates the size of the entity-body, in decimal number of OCTETs, sent to the recipient or, in the case of the HEAD method, the size of the entity-body that would have been sent had the request been a GET.

It doesn't matter what the content-type is.

Extension at post below.

Remove folder and its contents from git/GitHub's history

In addition to the popular answer above I would like to add a few notes for Windows-systems. The command

git filter-branch --tree-filter 'rm -rf node_modules' --prune-empty HEAD
  • works perfectly without any modification! Therefore, you must not use Remove-Item, del or anything else instead of rm -rf.

  • If you need to specify a path to a file or directory use slashes like ./path/to/node_modules

Failed to load resource: the server responded with a status of 500 (Internal Server Error) in Bind function

The 500 code would normally indicate an error on the server, not anything with your code. Some thoughts

  • Talk to the server developer for more info. You can't get more info directly.
  • Verify your arguments into the call (values). Look for anything you might think could cause a problem for the server process. The process should not die and should return you a better code, but bugs happen there also.
  • Could be intermittent, like if the server database goes down. May be worth trying at another time.

Can I set background image and opacity in the same property?

I just added position=absolute,top=0,width=100% in the #main and set the opacity value to the #background

#main{height:100%;position:absolute; top:0;width:100%}
#background{//same height as main;background-image:url(image URL);opacity:0.2}

I applied the background to a div before the main.

Check if certain value is contained in a dataframe column in pandas

You can use any:

print any(df.column == 07311954)
True       #true if it contains the number, false otherwise

If you rather want to see how many times '07311954' occurs in a column you can use:

df.column[df.column == 07311954].count()

C: convert double to float, preserving decimal point precision

A float generally has about 7 digits of precision, regardless of the position of the decimal point. So if you want 5 digits of precision after the decimal, you'll need to limit the range of the numbers to less than somewhere around +/-100.

How do you sign a Certificate Signing Request with your Certification Authority?

1. Using the x509 module
openssl x509 ...
...

2 Using the ca module
openssl ca ...
...

You are missing the prelude to those commands.

This is a two-step process. First you set up your CA, and then you sign an end entity certificate (a.k.a server or user). Both of the two commands elide the two steps into one. And both assume you have a an OpenSSL configuration file already setup for both CAs and Server (end entity) certificates.


First, create a basic configuration file:

$ touch openssl-ca.cnf

Then, add the following to it:

HOME            = .
RANDFILE        = $ENV::HOME/.rnd

####################################################################
[ ca ]
default_ca    = CA_default      # The default ca section

[ CA_default ]

default_days     = 1000         # How long to certify for
default_crl_days = 30           # How long before next CRL
default_md       = sha256       # Use public key default MD
preserve         = no           # Keep passed DN ordering

x509_extensions = ca_extensions # The extensions to add to the cert

email_in_dn     = no            # Don't concat the email in the DN
copy_extensions = copy          # Required to copy SANs from CSR to cert

####################################################################
[ req ]
default_bits       = 4096
default_keyfile    = cakey.pem
distinguished_name = ca_distinguished_name
x509_extensions    = ca_extensions
string_mask        = utf8only

####################################################################
[ ca_distinguished_name ]
countryName         = Country Name (2 letter code)
countryName_default = US

stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = Maryland

localityName                = Locality Name (eg, city)
localityName_default        = Baltimore

organizationName            = Organization Name (eg, company)
organizationName_default    = Test CA, Limited

organizationalUnitName         = Organizational Unit (eg, division)
organizationalUnitName_default = Server Research Department

commonName         = Common Name (e.g. server FQDN or YOUR name)
commonName_default = Test CA

emailAddress         = Email Address
emailAddress_default = [email protected]

####################################################################
[ ca_extensions ]

subjectKeyIdentifier   = hash
authorityKeyIdentifier = keyid:always, issuer
basicConstraints       = critical, CA:true
keyUsage               = keyCertSign, cRLSign

The fields above are taken from a more complex openssl.cnf (you can find it in /usr/lib/openssl.cnf), but I think they are the essentials for creating the CA certificate and private key.

Tweak the fields above to suit your taste. The defaults save you the time from entering the same information while experimenting with configuration file and command options.

I omitted the CRL-relevant stuff, but your CA operations should have them. See openssl.cnf and the related crl_ext section.

Then, execute the following. The -nodes omits the password or passphrase so you can examine the certificate. It's a really bad idea to omit the password or passphrase.

$ openssl req -x509 -config openssl-ca.cnf -newkey rsa:4096 -sha256 -nodes -out cacert.pem -outform PEM

After the command executes, cacert.pem will be your certificate for CA operations, and cakey.pem will be the private key. Recall the private key does not have a password or passphrase.

You can dump the certificate with the following.

$ openssl x509 -in cacert.pem -text -noout
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 11485830970703032316 (0x9f65de69ceef2ffc)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, ST=MD, L=Baltimore, CN=Test CA/[email protected]
        Validity
            Not Before: Jan 24 14:24:11 2014 GMT
            Not After : Feb 23 14:24:11 2014 GMT
        Subject: C=US, ST=MD, L=Baltimore, CN=Test CA/[email protected]
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (4096 bit)
                Modulus:
                    00:b1:7f:29:be:78:02:b8:56:54:2d:2c:ec:ff:6d:
                    ...
                    39:f9:1e:52:cb:8e:bf:8b:9e:a6:93:e1:22:09:8b:
                    59:05:9f
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Subject Key Identifier:
                4A:9A:F3:10:9E:D7:CF:54:79:DE:46:75:7A:B0:D0:C1:0F:CF:C1:8A
            X509v3 Authority Key Identifier:
                keyid:4A:9A:F3:10:9E:D7:CF:54:79:DE:46:75:7A:B0:D0:C1:0F:CF:C1:8A

            X509v3 Basic Constraints: critical
                CA:TRUE
            X509v3 Key Usage:
                Certificate Sign, CRL Sign
    Signature Algorithm: sha256WithRSAEncryption
         4a:6f:1f:ac:fd:fb:1e:a4:6d:08:eb:f5:af:f6:1e:48:a5:c7:
         ...
         cd:c6:ac:30:f9:15:83:41:c1:d1:20:fa:85:e7:4f:35:8f:b5:
         38:ff:fd:55:68:2c:3e:37

And test its purpose with the following (don't worry about the Any Purpose: Yes; see "critical,CA:FALSE" but "Any Purpose CA : Yes").

$ openssl x509 -purpose -in cacert.pem -inform PEM
Certificate purposes:
SSL client : No
SSL client CA : Yes
SSL server : No
SSL server CA : Yes
Netscape SSL server : No
Netscape SSL server CA : Yes
S/MIME signing : No
S/MIME signing CA : Yes
S/MIME encryption : No
S/MIME encryption CA : Yes
CRL signing : Yes
CRL signing CA : Yes
Any Purpose : Yes
Any Purpose CA : Yes
OCSP helper : Yes
OCSP helper CA : Yes
Time Stamp signing : No
Time Stamp signing CA : Yes
-----BEGIN CERTIFICATE-----
MIIFpTCCA42gAwIBAgIJAJ9l3mnO7y/8MA0GCSqGSIb3DQEBCwUAMGExCzAJBgNV
...
aQUtFrV4hpmJUaQZ7ySr/RjCb4KYkQpTkOtKJOU1Ic3GrDD5FYNBwdEg+oXnTzWP
tTj//VVoLD43
-----END CERTIFICATE-----

For part two, I'm going to create another configuration file that's easily digestible. First, touch the openssl-server.cnf (you can make one of these for user certificates also).

$ touch openssl-server.cnf

Then open it, and add the following.

HOME            = .
RANDFILE        = $ENV::HOME/.rnd

####################################################################
[ req ]
default_bits       = 2048
default_keyfile    = serverkey.pem
distinguished_name = server_distinguished_name
req_extensions     = server_req_extensions
string_mask        = utf8only

####################################################################
[ server_distinguished_name ]
countryName         = Country Name (2 letter code)
countryName_default = US

stateOrProvinceName         = State or Province Name (full name)
stateOrProvinceName_default = MD

localityName         = Locality Name (eg, city)
localityName_default = Baltimore

organizationName            = Organization Name (eg, company)
organizationName_default    = Test Server, Limited

commonName           = Common Name (e.g. server FQDN or YOUR name)
commonName_default   = Test Server

emailAddress         = Email Address
emailAddress_default = [email protected]

####################################################################
[ server_req_extensions ]

subjectKeyIdentifier = hash
basicConstraints     = CA:FALSE
keyUsage             = digitalSignature, keyEncipherment
subjectAltName       = @alternate_names
nsComment            = "OpenSSL Generated Certificate"

####################################################################
[ alternate_names ]

DNS.1  = example.com
DNS.2  = www.example.com
DNS.3  = mail.example.com
DNS.4  = ftp.example.com

If you are developing and need to use your workstation as a server, then you may need to do the following for Chrome. Otherwise Chrome may complain a Common Name is invalid (ERR_CERT_COMMON_NAME_INVALID). I'm not sure what the relationship is between an IP address in the SAN and a CN in this instance.

# IPv4 localhost
IP.1     = 127.0.0.1

# IPv6 localhost
IP.2     = ::1

Then, create the server certificate request. Be sure to omit -x509*. Adding -x509 will create a certificate, and not a request.

$ openssl req -config openssl-server.cnf -newkey rsa:2048 -sha256 -nodes -out servercert.csr -outform PEM

After this command executes, you will have a request in servercert.csr and a private key in serverkey.pem.

And you can inspect it again.

$ openssl req -text -noout -verify -in servercert.csr
Certificate:
    verify OK
    Certificate Request:
        Version: 0 (0x0)
        Subject: C=US, ST=MD, L=Baltimore, CN=Test Server/[email protected]
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    00:ce:3d:58:7f:a0:59:92:aa:7c:a0:82:dc:c9:6d:
                    ...
                    f9:5e:0c:ba:84:eb:27:0d:d9:e7:22:5d:fe:e5:51:
                    86:e1
                Exponent: 65537 (0x10001)
        Attributes:
        Requested Extensions:
            X509v3 Subject Key Identifier:
                1F:09:EF:79:9A:73:36:C1:80:52:60:2D:03:53:C7:B6:BD:63:3B:61
            X509v3 Basic Constraints:
                CA:FALSE
            X509v3 Key Usage:
                Digital Signature, Key Encipherment
            X509v3 Subject Alternative Name:
                DNS:example.com, DNS:www.example.com, DNS:mail.example.com, DNS:ftp.example.com
            Netscape Comment:
                OpenSSL Generated Certificate
    Signature Algorithm: sha256WithRSAEncryption
         6d:e8:d3:85:b3:88:d4:1a:80:9e:67:0d:37:46:db:4d:9a:81:
         ...
         76:6a:22:0a:41:45:1f:e2:d6:e4:8f:a1:ca:de:e5:69:98:88:
         a9:63:d0:a7

Next, you have to sign it with your CA.


You are almost ready to sign the server's certificate by your CA. The CA's openssl-ca.cnf needs two more sections before issuing the command.

First, open openssl-ca.cnf and add the following two sections.

####################################################################
[ signing_policy ]
countryName            = optional
stateOrProvinceName    = optional
localityName           = optional
organizationName       = optional
organizationalUnitName = optional
commonName             = supplied
emailAddress           = optional

####################################################################
[ signing_req ]
subjectKeyIdentifier   = hash
authorityKeyIdentifier = keyid,issuer
basicConstraints       = CA:FALSE
keyUsage               = digitalSignature, keyEncipherment

Second, add the following to the [ CA_default ] section of openssl-ca.cnf. I left them out earlier, because they can complicate things (they were unused at the time). Now you'll see how they are used, so hopefully they will make sense.

base_dir      = .
certificate   = $base_dir/cacert.pem   # The CA certifcate
private_key   = $base_dir/cakey.pem    # The CA private key
new_certs_dir = $base_dir              # Location for new certs after signing
database      = $base_dir/index.txt    # Database index file
serial        = $base_dir/serial.txt   # The current serial number

unique_subject = no  # Set to 'no' to allow creation of
                     # several certificates with same subject.

Third, touch index.txt and serial.txt:

$ touch index.txt
$ echo '01' > serial.txt

Then, perform the following:

$ openssl ca -config openssl-ca.cnf -policy signing_policy -extensions signing_req -out servercert.pem -infiles servercert.csr

You should see similar to the following:

Using configuration from openssl-ca.cnf
Check that the request matches the signature
Signature ok
The Subject's Distinguished Name is as follows
countryName           :PRINTABLE:'US'
stateOrProvinceName   :ASN.1 12:'MD'
localityName          :ASN.1 12:'Baltimore'
commonName            :ASN.1 12:'Test CA'
emailAddress          :IA5STRING:'[email protected]'
Certificate is to be certified until Oct 20 16:12:39 2016 GMT (1000 days)
Sign the certificate? [y/n]:Y

1 out of 1 certificate requests certified, commit? [y/n]Y
Write out database with 1 new entries
Data Base Updated

After the command executes, you will have a freshly minted server certificate in servercert.pem. The private key was created earlier and is available in serverkey.pem.

Finally, you can inspect your freshly minted certificate with the following:

$ openssl x509 -in servercert.pem -text -noout
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number: 9 (0x9)
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=US, ST=MD, L=Baltimore, CN=Test CA/[email protected]
        Validity
            Not Before: Jan 24 19:07:36 2014 GMT
            Not After : Oct 20 19:07:36 2016 GMT
        Subject: C=US, ST=MD, L=Baltimore, CN=Test Server
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    00:ce:3d:58:7f:a0:59:92:aa:7c:a0:82:dc:c9:6d:
                    ...
                    f9:5e:0c:ba:84:eb:27:0d:d9:e7:22:5d:fe:e5:51:
                    86:e1
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Subject Key Identifier:
                1F:09:EF:79:9A:73:36:C1:80:52:60:2D:03:53:C7:B6:BD:63:3B:61
            X509v3 Authority Key Identifier:
                keyid:42:15:F2:CA:9C:B1:BB:F5:4C:2C:66:27:DA:6D:2E:5F:BA:0F:C5:9E

            X509v3 Basic Constraints:
                CA:FALSE
            X509v3 Key Usage:
                Digital Signature, Key Encipherment
            X509v3 Subject Alternative Name:
                DNS:example.com, DNS:www.example.com, DNS:mail.example.com, DNS:ftp.example.com
            Netscape Comment:
                OpenSSL Generated Certificate
    Signature Algorithm: sha256WithRSAEncryption
         b1:40:f6:34:f4:38:c8:57:d4:b6:08:f7:e2:71:12:6b:0e:4a:
         ...
         45:71:06:a9:86:b6:0f:6d:8d:e1:c5:97:8d:fd:59:43:e9:3c:
         56:a5:eb:c8:7e:9f:6b:7a

Earlier, you added the following to CA_default: copy_extensions = copy. This copies extension provided by the person making the request.

If you omit copy_extensions = copy, then your server certificate will lack the Subject Alternate Names (SANs) like www.example.com and mail.example.com.

If you use copy_extensions = copy, but don't look over the request, then the requester might be able to trick you into signing something like a subordinate root (rather than a server or user certificate). Which means he/she will be able to mint certificates that chain back to your trusted root. Be sure to verify the request with openssl req -verify before signing.


If you omit unique_subject or set it to yes, then you will only be allowed to create one certificate under the subject's distinguished name.

unique_subject = yes            # Set to 'no' to allow creation of
                                # several ctificates with same subject.

Trying to create a second certificate while experimenting will result in the following when signing your server's certificate with the CA's private key:

Sign the certificate? [y/n]:Y
failed to update database
TXT_DB error number 2

So unique_subject = no is perfect for testing.


If you want to ensure the Organizational Name is consistent between self-signed CAs, Subordinate CA and End-Entity certificates, then add the following to your CA configuration files:

[ policy_match ]
organizationName = match

If you want to allow the Organizational Name to change, then use:

[ policy_match ]
organizationName = supplied

There are other rules concerning the handling of DNS names in X.509/PKIX certificates. Refer to these documents for the rules:

RFC 6797 and RFC 7469 are listed, because they are more restrictive than the other RFCs and CA/B documents. RFC's 6797 and 7469 do not allow an IP address, either.

Checking if an input field is required using jQuery

You don't need jQuery to do this. Here's an ES2015 solution:

// Get all input fields
const inputs = document.querySelectorAll('#register input');

// Get only the required ones
const requiredFields = Array.from(inputs).filter(input => input.required);

// Do your stuff with the required fields
requiredFields.forEach(field => /* do what you want */);

Or you could just use the :required selector:

Array.from(document.querySelectorAll('#register input:required'))
    .forEach(field => /* do what you want */);

Angular/RxJs When should I unsubscribe from `Subscription`

You usually need to unsubscribe when the components get destroyed, but Angular is going to handle it more and more as we go, for example in new minor version of Angular4, they have this section for routing unsubscribe:

Do you need to unsubscribe?

As described in the ActivatedRoute: the one-stop-shop for route information section of the Routing & Navigation page, the Router manages the observables it provides and localizes the subscriptions. The subscriptions are cleaned up when the component is destroyed, protecting against memory leaks, so you don't need to unsubscribe from the route paramMap Observable.

Also the example below is a good example from Angular to create a component and destroy it after, look at how component implements OnDestroy, if you need onInit, you also can implements it in your component, like implements OnInit, OnDestroy

import { Component, Input, OnDestroy } from '@angular/core';  
import { MissionService } from './mission.service';
import { Subscription }   from 'rxjs/Subscription';

@Component({
  selector: 'my-astronaut',
  template: `
    <p>
      {{astronaut}}: <strong>{{mission}}</strong>
      <button
        (click)="confirm()"
        [disabled]="!announced || confirmed">
        Confirm
      </button>
    </p>
  `
})

export class AstronautComponent implements OnDestroy {
  @Input() astronaut: string;
  mission = '<no mission announced>';
  confirmed = false;
  announced = false;
  subscription: Subscription;

  constructor(private missionService: MissionService) {
    this.subscription = missionService.missionAnnounced$.subscribe(
      mission => {
        this.mission = mission;
        this.announced = true;
        this.confirmed = false;
    });
  }

  confirm() {
    this.confirmed = true;
    this.missionService.confirmMission(this.astronaut);
  }

  ngOnDestroy() {
    // prevent memory leak when component destroyed
    this.subscription.unsubscribe();
  }
}

How to use php serialize() and unserialize()

preg_match_all('/\".*?\"/i', $string, $matches);
foreach ($matches[0] as $i => $match) $matches[$i] = trim($match, '"');

Implementing INotifyPropertyChanged - does a better way exist?

I keep this around as a snippet. C# 6 adds some nice syntax for invoking the handler.

// INotifyPropertyChanged

public event PropertyChangedEventHandler PropertyChanged;

private void Set<T>(ref T property, T value, [CallerMemberName] string propertyName = null)
{
    if (EqualityComparer<T>.Default.Equals(property, value) == false)
    {
        property = value;
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

Selecting multiple classes with jQuery

This should work:

$('.myClass, .myOtherClass').removeClass('theclass');

You must add the multiple selectors all in the first argument to $(), otherwise you are giving jQuery a context in which to search, which is not what you want.

It's the same as you would do in CSS.

Deserialize json object into dynamic object using Json.net

I know this is old post but JsonConvert actually has a different method so it would be

var product = new { Name = "", Price = 0 };
var jsonResponse = JsonConvert.DeserializeAnonymousType(json, product);

Bootstrap4 adding scrollbar to div

_x000D_
_x000D_
.Scroll {
  height:600px;
  overflow-y: scroll;
}
_x000D_
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
</script>
</head>
<body>

<h1>Smooth Scroll</h1>

<div class="Scroll">
  <div class="main" id="section1">
    <h2>Section 1</h2>
    <p>Click on the link to see the "smooth" scrolling effect.</p>
    <p>Note: Remove the scroll-behavior property to remove smooth scrolling.</p>
  </div>
  <div class="main" id="section2">
    <h2>Section 2</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section3">
    <h2>Section 3</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section4">
    <h2>Section 4</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>

  <div class="main" id="section5">
    <h2>Section 5</h2>
    <a href="#section1">Click Me to Smooth Scroll to Section 1 Above</a>
  </div>
  <div class="main" id="section6">
    <h2>Section 6</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section7">
    <h2>Section 7</h2>
    <a href="#section1">Click Me to Smooth Scroll to Section 1 Above</a>
  </div>
</div>
</body>
</html>
_x000D_
_x000D_
_x000D_

How can you have SharePoint Link Lists default to opening in a new window?

You can edit the page in SharePoint designer, convert the List View web part to an XSLT Data View. (by right click + "Convert to XSLT Data View").
Then you can edit the XSLT - find the A tag and add an attribute target="_blank"

Change default timeout for mocha

Just adding to the correct answer you can set the timeout with the arrow function like this:

it('Some test', () => {

}).timeout(5000)

Difference between Destroy and Delete

Basically destroy runs any callbacks on the model while delete doesn't.

From the Rails API:

  • ActiveRecord::Persistence.delete

    Deletes the record in the database and freezes this instance to reflect that no changes should be made (since they can't be persisted). Returns the frozen instance.

    The row is simply removed with an SQL DELETE statement on the record's primary key, and no callbacks are executed.

    To enforce the object's before_destroy and after_destroy callbacks or any :dependent association options, use #destroy.

  • ActiveRecord::Persistence.destroy

    Deletes the record in the database and freezes this instance to reflect that no changes should be made (since they can't be persisted).

    There's a series of callbacks associated with destroy. If the before_destroy callback return false the action is cancelled and destroy returns false. See ActiveRecord::Callbacks for further details.

Missing visible-** and hidden-** in Bootstrap v4

The user Klaro suggested to restore the old visibility classes, which is a good idea. Unfortunately, their solution did not work in my project.

I think that it is a better idea to restore the old mixin of bootstrap, because it is covering all breakpoints which can be individually defined by the user.

Here is the code:

// Restore Bootstrap 3 "hidden" utility classes.
@each $bp in map-keys($grid-breakpoints) {
  .hidden-#{$bp}-up {
    @include media-breakpoint-up($bp) {
      display: none !important;
    }
  }
  .hidden-#{$bp}-down {
    @include media-breakpoint-down($bp) {
      display: none !important;
    }
  }
  .hidden-#{$bp}-only{
    @include media-breakpoint-only($bp){
      display:none !important;
    }
  }
}

In my case, I have inserted this part in a _custom.scss file which is included at this point in the bootstrap.scss:

/*!
 * Bootstrap v4.0.0-beta (https://getbootstrap.com)
 * Copyright 2011-2017 The Bootstrap Authors
 * Copyright 2011-2017 Twitter, Inc.
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
 */

@import "functions";
@import "variables";
@import "mixins";
@import "custom"; // <-- my custom file for overwriting default vars and adding the snippet from above
@import "print";
@import "reboot";
[..]

How to open a new form from another form

You need to control the opening of sub forms from a main form.

In my case I'm opening a Login window first before I launch my form1. I control everything from Program.cs. Set up a validation flag in Program.cs. Open Login window from Program.cs. Control then goes to login window. Then if the validation is good, set the validation flag to true from the login window. Now you can safely close the login window. Control returns to Program.cs. If the validation flag is true, open form1. If the validation flag is false, your application will close.

In Program.cs:

   static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        /// 

        //Validation flag
        public static bool ValidLogin = false;

        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);


            Application.Run(new Login());

            if (ValidLogin)
            {
                Application.Run(new Form1());
            }
        }

    }

In Login.cs:

       private void btnOK_Click(object sender, EventArgs e)
        {
            if (txtUsername.Text == "x" && txtPassword.Text == "x")
            {
                Program.ValidLogin = true;
                this.Close();
            }
            else
            {
                MessageBox.Show("Username or Password are incorrect.");
            }
        }

        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

java.util.Date and getYear()

Use date format

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date date = format.parse(datetime);
SimpleDateFormat df = new SimpleDateFormat("yyyy");
year = df.format(date);

foreach with index

My solution involves a simple Pair class I created for general utility, and which is operationally essentially the same as the framework class KeyValuePair. Then I created a couple extension functions for IEnumerable called Ordinate (from the set theory term "ordinal").

These functions will return for each item a Pair object containing the index, and the item itself.

public static IEnumerable<Pair<Int32, X>> Ordinate<X>(this IEnumerable<X> lhs)
{
    return lhs.Ordinate(0);
}

public static IEnumerable<Pair<Int32, X>> Ordinate<X>(this IEnumerable<X> lhs, Int32 initial)
{
    Int32 index = initial - 1;

    return lhs.Select(x => new Pair<Int32, X>(++index, x));
}

HTML Best Practices: Should I use &rsquo; or the special keyboard shortcut?

One risk of using the keyboard shortcut is that it requires using a non-ASCII encoding. That might be fine, but if your source is loaded by different editors in different locales, you might hit trouble somewhere along the line.

It might be safer to use either &#8217; or &rsquo; (which are equivalent) as both are ASCII.

What is the difference between statically typed and dynamically typed languages?

Statically typed languages type-check at compile time and the type can NOT change. (Don't get cute with type-casting comments, a new variable/reference is created).

Dynamically typed languages type-check at run-time and the type of an variable CAN be changed at run-time.

Is it possible to run .php files on my local computer?

Sure you just need to setup a local web server. Check out XAMPP: http://www.apachefriends.org/en/xampp.html

That will get you up and running in about 10 minutes.

There is now a way to run php locally without installing a server: https://stackoverflow.com/a/21872484/672229


Yes but the files need to be processed. For example you can install test servers like mamp / lamp / wamp depending on your plateform.

Basically you need apache / php running.

error: Error parsing XML: not well-formed (invalid token) ...?

In my case I forgot to end my ConstrainLayout

</android.support.constraint.ConstraintLayout>

After that, everything started working correctly.

How can I save a base64-encoded image to disk?

This did it for me simply and perfectly.

Excellent explanation by Scott Robinson

From image to base64 string

let buff = fs.readFileSync('stack-abuse-logo.png');
let base64data = buff.toString('base64');

From base64 string to image

let buff = new Buffer(data, 'base64');
fs.writeFileSync('stack-abuse-logo-out.png', buff);

How to add an ORDER BY clause using CodeIgniter's Active Record methods?

Just add the'order_by' clause to your code and modify it to look just like the one below.

$this->db->order_by('name', 'asc');
$result = $this->db->get($table);

There you go.

How to use confirm using sweet alert?

inside your save button click add this code :

$("#btnSave").click(function (e) {
  e.preventDefault();
  swal("Are you sure?", {
    buttons: {
      yes: {
        text: "Yes",
        value: "yes"
      },
      no: {
        text: "No",
        value: "no"
      }
    }
  }).then((value) => {
    if (value === "yes") {
      // Add Your Custom Code for CRUD
    }
    return false;
  });
});

How to default to other directory instead of home directory

(Please read warning below)

Really simple way to do this in Windows (works with git bash, possibly others) is to create an environmental variable called HOME that points to your desired home directory.

  1. Right click on my computer, and choose properties
  2. Choose advanced system settings (location varies by Windows version)
  3. Within system properties, choose the advanced tab
  4. On the advanced tab, choose Environmental Variables (bottom button)
  5. Under "system variable" check to see if you already have a variable called HOME. If so, edit that variable by highlighting the variable name and clicking edit. Make the new variable name the desired path.
  6. If HOME does not already exist, click "new" under system variables and create a new variable called HOME whose value is desired path.

Environmental Variable

NOTE: This may change the way other things work. For example, for me it changes where my .ssh config files live. In my case, I wanted my home to be U:\, because that's my main place that I put project work and application settings (i.e. it really is my "home" directory).

EDIT June 23, 2017: This answer continues to get occasional upvotes, and I want to warn people that although this may "work", I agree with @AnthonyRaymond that it's not recommended. This is more of a temporary fix or a fix if you don't care if other things break. Changing your home won't cause active damage (like deleting your hard drive) but it's likely to cause insidious annoyances later. When you do start to have annoying problems down the road, you probably won't remember this change... so you're likely to be scratching your head later on!

How to split a large text file into smaller files with equal number of lines?

you can also use awk

awk -vc=1 'NR%200000==0{++c}{print $0 > c".txt"}' largefile

How can I align the columns of tables in Bash?

Below code has been tested and does exactly what is requested in the original question.

Parameters: %30s Column of 30 char and text right align. %10d integer notation, %10s will also work. Added clarification included on code comments.

stringarray[0]="a very long string.........."
# 28Char (max length for this column)
numberarray[0]=1122324333
# 10digits (max length for this column)
anotherfield[0]="anotherfield"
# 12Char (max length for this column)
stringarray[1]="a smaller string....."
numberarray[1]=123124343
anotherfield[1]="anotherfield"

printf "%30s %10d %13s" "${stringarray[0]}" ${numberarray[0]} "${anotherfield[0]}"
printf "\n"
printf "%30s %10d %13s" "${stringarray[1]}" ${numberarray[1]} "${anotherfield[1]}"
# a var string with spaces has to be quoted
printf "\n Next line will fail \n"      
printf "%30s %10d %13s" ${stringarray[0]} ${numberarray[0]} "${anotherfield[0]}"



  a very long string.......... 1122324333  anotherfield
         a smaller string.....  123124343  anotherfield

How to add a new row to datagridview programmatically

If anyone wanted to Add DataTable as a source of gridview then--

DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("column1"));
dt.Columns.Add(new DataColumn("column2"));

DataRow dr = dt.NewRow();
dr[0] = "column1 Value";
dr[1] = "column2 Value";

dt.Rows.Add(dr);

dataGridView1.DataSource = dt;

I can pass a variable from a JSP scriptlet to JSTL but not from JSTL to a JSP scriptlet without an error

@skaffman nailed it down. They live each in its own context. However, I wouldn't consider using scriptlets as the solution. You'd like to avoid them. If all you want is to concatenate strings in EL and you discovered that the + operator fails for strings in EL (which is correct), then just do:

<c:out value="abc${test}" />

Or if abc is to obtained from another scoped variable named ${resp}, then do:

<c:out value="${resp}${test}" />

VB.net Need Text Box to Only Accept Numbers

Simplest ever solution for TextBox Validation in VB.NET

TextBox Validation for Visual Basic (VB.NET)

First, add new VB code file in your project.

  1. Go To Solution Explorer
  2. Right Click to your project
  3. Select Add > New item...
  4. Add new VB code file (i.e. example.vb)

or press Ctrl+Shift+A

COPY & PASTE following code into this file and give it a suitable name. (i.e. KeyValidation.vb)

Imports System.Text.RegularExpressions
Module Module1
    Public Enum ValidationType
        Only_Numbers = 1
        Only_Characters = 2
        Not_Null = 3
        Only_Email = 4
        Phone_Number = 5
    End Enum
    Public Sub AssignValidation(ByRef CTRL As Windows.Forms.TextBox, ByVal Validation_Type As ValidationType)
        Dim txt As Windows.Forms.TextBox = CTRL
        Select Case Validation_Type
            Case ValidationType.Only_Numbers
                AddHandler txt.KeyPress, AddressOf number_Leave
            Case ValidationType.Only_Characters
                AddHandler txt.KeyPress, AddressOf OCHAR_Leave
            Case ValidationType.Not_Null
                AddHandler txt.Leave, AddressOf NotNull_Leave
            Case ValidationType.Only_Email
                AddHandler txt.Leave, AddressOf Email_Leave
            Case ValidationType.Phone_Number
                AddHandler txt.KeyPress, AddressOf Phonenumber_Leave
        End Select
    End Sub
    Public Sub number_Leave(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)
        Dim numbers As Windows.Forms.TextBox = sender
        If InStr("1234567890.", e.KeyChar) = 0 And Asc(e.KeyChar) <> 8 Or (e.KeyChar = "." And InStr(numbers.Text, ".") > 0) Then
            e.KeyChar = Chr(0)
            e.Handled = True
        End If
    End Sub
    Public Sub Phonenumber_Leave(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)
        Dim numbers As Windows.Forms.TextBox = sender
        If InStr("1234567890.()-+ ", e.KeyChar) = 0 And Asc(e.KeyChar) <> 8 Or (e.KeyChar = "." And InStr(numbers.Text, ".") > 0) Then
            e.KeyChar = Chr(0)
            e.Handled = True
        End If
    End Sub
    Public Sub OCHAR_Leave(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)
        If InStr("1234567890!@#$%^&*()_+=-", e.KeyChar) > 0 Then
            e.KeyChar = Chr(0)
            e.Handled = True
        End If
    End Sub
    Public Sub NotNull_Leave(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim No As Windows.Forms.TextBox = sender
        If No.Text.Trim = "" Then
            MsgBox("This field Must be filled!")
            No.Focus()
        End If
    End Sub
    Public Sub Email_Leave(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim Email As Windows.Forms.TextBox = sender
        If Email.Text <> "" Then
            Dim rex As Match = Regex.Match(Trim(Email.Text), "^([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,3})$", RegexOptions.IgnoreCase)
            If rex.Success = False Then
                MessageBox.Show("Please Enter a valid Email Address", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Email.BackColor = Color.Red
                Email.Focus()
                Exit Sub
            Else
                Email.BackColor = Color.White
            End If
        End If
    End Sub
End Module

Now use following code to Form Load Event like below.

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AssignValidation(Me.TextBox1, ValidationType.Only_Digits)
        AssignValidation(Me.TextBox2, ValidationType.Only_Characters)
        AssignValidation(Me.TextBox3, ValidationType.No_Blank)
        AssignValidation(Me.TextBox4, ValidationType.Only_Email)
End Sub

Done..!

How and when to use SLEEP() correctly in MySQL?

If you don't want to SELECT SLEEP(1);, you can also DO SLEEP(1); It's useful for those situations in procedures where you don't want to see output.

e.g.

SELECT ...
DO SLEEP(5);
SELECT ...

Which icon sizes should my Windows application's icon include?

The Microsoft UX icon guideline says:

"Application icons and Control Panel items: The full set includes 16x16, 32x32, 48x48, and 256x256 (code scales between 32 and 256)."

To me this implies (but does not explicitly state, unfortunately) that you should supply those 4 sizes.

Additional details regarding color formats, which you may also find useful:

  • "Icon files require 8-bit and 4-bit palette versions as well, to support the default setting in a remote desktop."

  • "Only a 32-bit copy of the 256x256 pixel image should be included, and only the 256x256 pixel image should be compressed [as PNG] to keep the file size down."

Percentage calculation

Using Math.Round():

int percentComplete = (int)Math.Round((double)(100 * complete) / total);

or manually rounding:

int percentComplete = (int)(0.5f + ((100f * complete) / total));

Python - TypeError: 'int' object is not iterable

This is very simple you are trying to convert an integer to a list object !!! of course it will fail and it should ...

To demonstrate/prove this to you by using the example you provided ...just use type function for each case as below and the results will speak for itself !

>>> type(cow)
<class 'range'>
>>> 
>>> type(cow[0])
<class 'int'>
>>> 
>>> type(0)
<class 'int'>
>>> 
>>> >>> list(0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable
>>> 

Creating dummy variables in pandas for python

Based on the official documentation:

dummies = pd.get_dummies(df['Category']).rename(columns=lambda x: 'Category_' + str(x))
df = pd.concat([df, dummies], axis=1)
df = df.drop(['Category'], inplace=True, axis=1)

There is also a nice post in the FastML blog.

how does Request.QueryString work?

The Request object is the entire request sent out to some server. This object comes with a QueryString dictionary that is everything after '?' in the URL.

Not sure exactly what you were looking for in an answer, but check out http://en.wikipedia.org/wiki/Query_string

SQL JOIN - WHERE clause vs. ON clause

I think it's the join sequence effect. In the upper left join case, SQL do Left join first and then do where filter. In the downer case, find Orders.ID=12345 first, and then do join.

Is there an "exists" function for jQuery?

The input won't have a value if it doesn't exist. Try this...

if($(selector).val())

SVN (Subversion) Problem "File is scheduled for addition, but is missing" - Using Versions

This solved my similar problem. I used it to revert the changes, then I added everything and commited changes in the terminal with

svn add folder_path/*
svn commit -m "message"

how to convert a string to date in mysql?

Here's another two examples.

To output the day, month, and year, you can use:

select STR_TO_DATE('14/02/2015', '%d/%m/%Y');

Which produces:

2015-02-14

To also output the time, you can use:

select STR_TO_DATE('14/02/2017 23:38:12', '%d/%m/%Y %T');

Which produces:

2017-02-14 23:38:12

SQL Server equivalent of MySQL's NOW()?

getdate() or getutcdate().

C# error: Use of unassigned local variable

The compiler doesn't know that the Environment.Exit() is going to terminate the program; it just sees you executing a static method on a class. Just initialize queue to null when you declare it.

Queue queue = null;

How to set HttpResponse timeout for Android in Java

If your are using Jakarta's http client library then you can do something like:

        HttpClient client = new HttpClient();
        client.getParams().setParameter(HttpClientParams.CONNECTION_MANAGER_TIMEOUT, new Long(5000));
        client.getParams().setParameter(HttpClientParams.SO_TIMEOUT, new Integer(5000));
        GetMethod method = new GetMethod("http://www.yoururl.com");
        method.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, new Integer(5000));
        method.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
        int statuscode = client.executeMethod(method);

div inside php echo

Just wrap it around then.

<?php        
    if ( ($cart->count_product) > 0) 
    { 
        echo "<div class='my_class'>";
        print $cart->count_product; 
        echo "</div>";
    }

?>

Manually put files to Android emulator SD card

If you are using Eclipse you can move files to and from the SD Card through the Android Perspective (it is called DDMS in Eclipse). Just select the Emulator in the left part of the screen and then choose the File Explorer tab. Above the list with your files should be two symbols, one with an arrow pointing at a phone, clicking this will allow you to choose a file to move to phone memory.

Undefined reference to vtable

What is a vtable?

It might be useful to know what the error message is talking about before trying to fix it. I'll start at a high level, then work down to some more details. That way people can skip ahead once they are comfortable with their understanding of vtables. …and there goes a bunch of people skipping ahead right now. :) For those sticking around:

A vtable is basically the most common implementation of polymorphism in C++. When vtables are used, every polymorphic class has a vtable somewhere in the program; you can think of it as a (hidden) static data member of the class. Every object of a polymorphic class is associated with the vtable for its most-derived class. By checking this association, the program can work its polymorphic magic. Important caveat: a vtable is an implementation detail. It is not mandated by the C++ standard, even though most (all?) C++ compilers use vtables to implement polymorphic behavior. The details I am presenting are either typical or reasonable approaches. Compilers are allowed to deviate from this!

Each polymorphic object has a (hidden) pointer to the vtable for the object's most-derived class (possibly multiple pointers, in the more complex cases). By looking at the pointer, the program can tell what the "real" type of an object is (except during construction, but let's skip that special case). For example, if an object of type A does not point to the vtable of A, then that object is actually a sub-object of something derived from A.

The name "vtable" comes from "virtual function table". It is a table that stores pointers to (virtual) functions. A compiler chooses its convention for how the table is laid out; a simple approach is to go through the virtual functions in the order they are declared within class definitions. When a virtual function is called, the program follows the object's pointer to a vtable, goes to the entry associated with the desired function, then uses the stored function pointer to invoke the correct function. There are various tricks for making this work, but I won't go into those here.

Where/when is a vtable generated?

A vtable is automatically generated (sometimes called "emitted") by the compiler. A compiler could emit a vtable in every translation unit that sees a polymorphic class definition, but that would usually be unnecessary overkill. An alternative (used by gcc, and probably by others) is to pick a single translation unit in which to place the vtable, similar to how you would pick a single source file in which to put a class' static data members. If this selection process fails to pick any translation units, then the vtable becomes an undefined reference. Hence the error, whose message is admittedly not particularly clear.

Similarly, if the selection process does pick a translation unit, but that object file is not provided to the linker, then the vtable becomes an undefined reference. Unfortunately, the error message can be even less clear in this case than in the case where the selection process failed. (Thanks to the answerers who mentioned this possibility. I probably would have forgotten it otherwise.)

The selection process used by gcc makes sense if we start with the tradition of devoting a (single) source file to each class that needs one for its implementation. It would be nice to emit the vtable when compiling that source file. Let's call that our goal. However, the selection process needs to work even if this tradition is not followed. So instead of looking for the implementation of the entire class, let's look for the implementation of a specific member of the class. If tradition is followed – and if that member is in fact implemented – then this achieves the goal.

The member selected by gcc (and potentially by other compilers) is the first non-inline virtual function that is not pure virtual. If you are part of the crowd that declares constructors and destructors before other member functions, then that destructor has a good chance of being selected. (You did remember to make the destructor virtual, right?) There are exceptions; I'd expect that the most common exceptions are when an inline definition is provided for the destructor and when the default destructor is requested (using "= default").

The astute might notice that a polymorphic class is allowed to provide inline definitions for all of its virtual functions. Doesn't that cause the selection process to fail? It does in older compilers. I've read that the latest compilers have addressed this situation, but I do not know relevant version numbers. I could try looking this up, but it's easier to either code around it or wait for the compiler to complain.

In summary, there are three key causes of the "undefined reference to vtable" error:

  1. A member function is missing its definition.
  2. An object file is not being linked.
  3. All virtual functions have inline definitions.

These causes are by themselves insufficient to cause the error on their own. Rather, these are what you would address to resolve the error. Do not expect that intentionally creating one of these situations will definitely produce this error; there are other requirements. Do expect that resolving these situations will resolve this error.

(OK, number 3 might have been sufficient when this question was asked.)

How to fix the error?

Welcome back people skipping ahead! :)

  1. Look at your class definition. Find the first non-inline virtual function that is not pure virtual (not "= 0") and whose definition you provide (not "= default").
    • If there is no such function, try modifying your class so there is one. (Error possibly resolved.)
    • See also the answer by Philip Thomas for a caveat.
  2. Find the definition for that function. If it is missing, add it! (Error possibly resolved.)
  3. Check your link command. If it does not mention the object file with that function's definition, fix that! (Error possibly resolved.)
  4. Repeat steps 2 and 3 for each virtual function, then for each non-virtual function, until the error is resolved. If you're still stuck, repeat for each static data member.

Example
The details of what to do can vary, and sometimes branch off into separate questions (like What is an undefined reference/unresolved external symbol error and how do I fix it?). I will, though, provide an example of what to do in a specific case that might befuddle newer programmers.

Step 1 mentions modifying your class so that it has a function of a certain type. If the description of that function went over your head, you might be in the situation I intend to address. Keep in mind that this is a way to accomplish the goal; it is not the only way, and there easily could be better ways in your specific situation. Let's call your class A. Is your destructor declared (in your class definition) as either

virtual ~A() = default;

or

virtual ~A() {}

? If so, two steps will change your destructor into the type of function we want. First, change that line to

virtual ~A();

Second, put the following line in a source file that is part of your project (preferably the file with the class implementation, if you have one):

A::~A() {}

That makes your (virtual) destructor non-inline and not generated by the compiler. (Feel free to modify things to better match your code formatting style, such as adding a header comment to the function definition.)

Linq Select Group By

You should try it like this:

var result =
        from priceLog in PriceLogList
        group priceLog by priceLog.LogDateTime.ToString("MMM yyyy") into dateGroup
        select new {
            LogDateTime = dateGroup.Key,
            AvgPrice = dateGroup.Average(priceLog => priceLog.Price)
        };

invalid_client in google oauth2

Setting EMAIL ADDRESS and PRODUCT NAME in the consent screen of Google developer console, solves the error "Error: invalid_client. The OAuth client was not found." for me.

Cannot find vcvarsall.bat when running a Python script

This cryptic error means that you don't have a C compiler installed. There was a discussion to propose a more explanative error (which is continued here, register and comment if you care about it!) but currently it is still not implemented.

To fix this issue you can either install the Visual Studio 2008 SDK which will take about a GB, or you can install the very small VCForPython27.msi but which is not well supported by distutils currently, here's the procedure:

1) install Microsoft Visual C++ Compiler for Python 2.7 from
http://www.microsoft.com/en-us/download/details.aspx?id=44266
2) Enter MSVC for Python command prompt
3) SET DISTUTILS_USE_SDK=1
4) SET MSSdk=1
5) you can then build your C extensions: python.exe setup.py ...

Steps 2 to 4 must be reproduced everytime before building your C extensions. This is because of an issue with the VCForPython27.msi which install the header files and vcvarsall.bat in folders of a different layout than the VS2008 SDK and thus confuse the compiler detection of distutils. This will get fixed in setuptools in Python 2.7.10.

Bug report and workaround by Gregory Szorc: http://bugs.python.org/issue23246

More info and a workaround for using %%cython magic inside IPython: https://github.com/cython/cython/wiki/CythonExtensionsOnWindows

/EDIT: Also, if you have another version of Python, you cannot use Microsoft Visual C++ for Python 2.7, which is a kind of mini-compiler specifically made by Microsoft for Python 2.7. In this case, you need to install the Visual Studio SDK that match your Python version, or a Windows SDK with the correct NET framework version. See here for more infos: https://github.com/cython/cython/wiki/CythonExtensionsOnWindows#using-windows-sdk-cc-compiler-works-for-all-python-versions

Cannot resolve symbol 'AppCompatActivity'

This is the lifesaver code I found somewhere(sorry don't remember the origin). Add it to build.gradle (Module:app). You can replace the version to the relevant.

configurations.all {

    resolutionStrategy.eachDependency { DependencyResolveDetails details -
        def requested = details.requested

 if (requested.group == 'com.android.support') {

            if (!requested.name.startsWith("multidex")) {
                details.useVersion '27.1.1'
            }
        } else if (requested.group == "com.google.android.gms") {
            details.useVersion '15.0.0'
        } else if (requested.group == "com.google.firebase") {
            details.useVersion '15.0.0'
        }
    }
}

How to uncheck checkbox using jQuery Uniform library

checkbox that act like radio btn

$(".checkgroup").live('change',function() { var previous=this.checked; $(".checkgroup).attr("checked", false); $(this).attr("checked", previous); });

Bash foreach loop

Here is a while loop:

while read filename
do
    echo "Printing: $filename"
    cat "$filename"
done < filenames.txt

Javascript: Load an Image from url and display

Are you after something like this:

 <html>
 <head>
    <title>Z Test</title>
 </head>
 <body>

<div id="img_home"></div>

<button onclick="addimage()" type="button">Add an image</button>

<script>
function addimage() {
    var img = new Image();
    img.src = "https://www.google.com/images/srpr/logo4w.png"
    img_home.appendChild(img);
}
</script>
</body>

How to parse the AndroidManifest.xml file inside an .apk package

it can be helpful

public static int vCodeApk(String path) {
    PackageManager pm = G.context.getPackageManager();
    PackageInfo info = pm.getPackageArchiveInfo(path, 0);
    return info.versionCode;
    //        Toast.makeText(this, "VersionCode : " + info.versionCode + ", VersionName : " + info.versionName, Toast.LENGTH_LONG).show();
}

G is my Application class :

public class G extends Application {

Create list of single item repeated N times

>>> [5] * 4
[5, 5, 5, 5]

Be careful when the item being repeated is a list. The list will not be cloned: all the elements will refer to the same list!

>>> x=[5]
>>> y=[x] * 4
>>> y
[[5], [5], [5], [5]]
>>> y[0][0] = 6
>>> y
[[6], [6], [6], [6]]

How to Create Multiple Where Clause Query Using Laravel Eloquent?

We use this instruction to obtain users according to two conditions, type of user classification and user name.

Here we use two conditions for filtering as you type in addition to fetching user information from the profiles table to reduce the number of queries.

$users = $this->user->where([
                    ['name','LIKE','%'.$request->name.'%'],
                    ['trainers_id','=',$request->trainers_id]
                    ])->with('profiles')->paginate(10);

Reducing the gap between a bullet and text in a list item

Reduce text-indent to a negative number to decrease the space between the list item's bullet and its text.

li {
  text-indent: -4px;
}

You can also use margin-left to adjust any space between the list-item's bullet and the edge of its surrounding element.

li {
  margin-left: 24px;
}

Both text-indent and padding-left can add space between the bullet and text, but only text-indent can reduce space to negative.

li { padding-left: -4px; } /* Doesn't work. */

File size exceeds configured limit (2560000), code insight features not available

PhpStorm 2020

  1. Help -> Edit Custom Properties.
  2. File will open in Editor. Paste the section below to the file.
 #---------------------------------------------------------------------
 # Maximum file size (kilobytes) IDE should provide code assistance for.
 # The larger file is the slower its editor works and higher overall system memory 
 requirements are
 # if code assistance is enabled. Remove this property or set to very large number 
 if you need
 # code assistance for any files available regardless their size.
 #---------------------------------------------------------------------
 idea.max.intellisense.filesize=2500
  1. File -> Invalidate / Restart -> Restart

This might not update sometimes and you might need to edit the root idea.properties file.

To edit this file for any version of Idea

  1. Go to application location i.e linux => /opt/PhpStorm[version]/bin
  2. Find file called idea.properties Make backup of file i.e idea.properties.old
  3. Open original with any txt editor.
  4. Find idea.max.intellisense.filesize=
  5. Replace with idea.max.intellisense.filesize=your_required_size i.e idea.max.intellisense.filesize=10480 NB by default this size is in kb
  6. Save and restart the IDE.

jQuery .each() with input elements

You can use:

$(formId).serializeArray();

Iterating over every property of an object in javascript using Prototype?

You should iterate over the keys and get the values using square brackets.

See: How do I enumerate the properties of a javascript object?

EDIT: Obviously, this makes the question a duplicate.

Best way to use Google's hosted jQuery, but fall back to my hosted library on Google fail

You might want to use your local file as a last resort.

Seems as of now jQuery's own CDN does not support https. If it did you then might want to load from there first.

So here's the sequence: Google CDN => Microsoft CDN => Your local copy.

<!-- load jQuery from Google's CDN -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script> 
<!-- fallback to Microsoft's Ajax CDN -->
<script> window.jQuery || document.write('<script src="//ajax.aspnetcdn.com/ajax/jQuery/jquery-1.8.3.min.js">\x3C/script>')</script> 
<!-- fallback to local file -->
<script> window.jQuery || document.write('<script src="Assets/jquery-1.8.3.min.js">\x3C/script>')</script> 

Laravel redirect back to original destination after login

First, you should know, how you redirect user to 'login' route:

return redirect()->guest('/signin');

Not like this:

return redirect()->intended('/signin');

How do you serialize a model instance in Django?

If you want to return the single model object as a json response to a client, you can do this simple solution:

from django.forms.models import model_to_dict
from django.http import JsonResponse

movie = Movie.objects.get(pk=1)
return JsonResponse(model_to_dict(movie))

How to change color of the back arrow in the new material theme?

Here's how I did it in Material Components:

<style name="AppTheme" parent="Theme.MaterialComponents.DayNight.NoActionBar">
    <item name="drawerArrowStyle">@style/AppTheme.DrawerArrowToggle</item>
</style>

<style name="AppTheme.DrawerArrowToggle" parent="Widget.AppCompat.DrawerArrowToggle">
    <item name="color">@android:color/white</item>
</style>

Send email with PHPMailer - embed image in body

I found the answer:

$mail->AddEmbeddedImage('img/2u_cs_mini.jpg', 'logo_2u');

and on the <img> tag put src='cid:logo_2u'

Why Visual Studio 2015 can't run exe file (ucrtbased.dll)?

I would like to suggest additional solution to fix this issue. So, I recommend to reinstall/install the latest Windows SDK. In my case it has helped me to fix the issue when using Qt with MSVC compiler to debug a program.

php refresh current page?

Another elegant one is

header("Location: http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]");
exit;

jQuery not working with IE 11

Adding the "x_ua_compatible" tag to the page didn't work for me. Instead I added it as an HTTP Respone Header via IIS and that worked fine.

In IIS Manager select the site then open HTTP Response Headers and click Add:

enter image description here

The site didn't need restarting, but I did need to Ctrl+F5 to force the page to reload.

RE error: illegal byte sequence on Mac OS X

You simply have to pipe an iconv command before the sed command. Ex with file.txt input :

iconv -f ISO-8859-1 -t UTF8-MAC file.txt | sed 's/something/àéèêçùû/g' | .....

-f option is the 'from' codeset and -t option is the 'to' codeset conversion.

Take care of case, web pages usually show lowercase like that < charset=iso-8859-1"/> and iconv uses uppercase. You have list of iconv supported codesets in you system with command iconv -l

UTF8-MAC is modern OS Mac codeset for conversion.

java : convert float to String and String to float

I believe the following code will help:

float f1 = 1.23f;
String f1Str = Float.toString(f1);      
float f2 = Float.parseFloat(f1Str);

How to convert data.frame column from Factor to numeric

This is FAQ 7.10. Others have shown how to apply this to a single column in a data frame, or to multiple columns in a data frame. But this is really treating the symptom, not curing the cause.

A better approach is to use the colClasses argument to read.table and related functions to tell R that the column should be numeric so that it never creates a factor and creates numeric. This will put in NA for any values that do not convert to numeric.

Another better option is to figure out why R does not recognize the column as numeric (usually a non numeric character somewhere in that column) and fix the original data so that it is read in properly without needing to create NAs.

Best is a combination of the last 2, make sure the data is correct before reading it in and specify colClasses so R does not need to guess (this can speed up reading as well).

Inverse of matrix in R

Note that if you care about speed and do not need to worry about singularities, solve() should be preferred to ginv() because it is much faster, as you can check:

require(MASS)
mat <- matrix(rnorm(1e6),nrow=1e3,ncol=1e3)

t0 <- proc.time()
inv0 <- ginv(mat)
proc.time() - t0 

t1 <- proc.time()
inv1 <- solve(mat)
proc.time() - t1 

How to use underscore.js as a template engine?

I am giving a very simple example

1)

var data = {site:"mysite",name:"john",age:25};
var template = "Welcome you are at <%=site %>.This has been created by <%=name %> whose age is <%=age%>";
var parsedTemplate = _.template(template,data);
console.log(parsedTemplate); 

The result would be

Welcome you are at mysite.This has been created by john whose age is 25.

2) This is a template

   <script type="text/template" id="template_1">
       <% _.each(items,function(item,key,arr) { %>
          <li>
             <span><%= key %></span>
             <span><%= item.name %></span>
             <span><%= item.type %></span>
           </li>
       <% }); %>
   </script>

This is html

<div>
  <ul id="list_2"></ul>
</div>

This is the javascript code which contains json object and putting template into html

   var items = [
       {
          name:"name1",
          type:"type1"
       },
       {
          name:"name1",
          type:"type1"
       },
       {
          name:"name1",
          type:"type1"
       },
       {
          name:"name1",
          type:"type1"
       },
       {
          name:"name1",
          type:"type1"
       } 
   ];
  $(document).ready(function(){
      var template = $("#template_1").html();
      $("#list_2").html(_.template(template,{items:items}));
  });

Hide Twitter Bootstrap nav collapse on click

If you have scrolling problems after using the jQuery solution described above, e.g.

$('.navbar-collapse').collapse('toggle');

then this is caused by Bootstrap adding the CSS class overlay-active in the parent element. This can even go up to your body element.

To solve this you have to remove this class:

<script type="text/javascript">
    $(document).ready(function(){

        $('.nav-item').click(function(){
            $('.overlay-active').removeClass('overlay-active');
        });

    });
</script>

How do you build a Singleton in Dart?

I use this simple pattern on dart and previously on Swift. I like that it's terse and only one way of using it.

class Singleton {
  static Singleton shared = Singleton._init();
  Singleton._init() {
    // init work here
  }

  void doSomething() {
  }
}

Singleton.shared.doSomething();

Add a new item to recyclerview programmatically?

First add your item to mItems and then use:

mAdapter.notifyItemInserted(mItems.size() - 1);

this method is better than using:

mAdapter.notifyDataSetChanged();

in performance.

Importing variables from another file?

Actually this is not really the same to import a variable with:

from file1 import x1
print(x1)

and

import file1
print(file1.x1)

Altough at import time x1 and file1.x1 have the same value, they are not the same variables. For instance, call a function in file1 that modifies x1 and then try to print the variable from the main file: you will not see the modified value.

Bootstrap collapse animation not smooth

Jerking happens when the parent div ".collapse" has padding.

Padding goes on the child div, not the parent. jQuery is animating the height, not the padding.

Example:

  <div class="form-group">
       <a for="collapseOne" data-toggle="collapse" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">+ addInfo</a>
       <div class="collapse" id="collapseOne" style="padding: 0;">
          <textarea class="form-control" rows="4" style="padding: 20px;"></textarea>
       </div>
  </div>

  <div class="form-group">
    <a for="collapseTwo" data-toggle="collapse" href="#collapseTwo" aria-expanded="true" aria-controls="collapseOne">+ subtitle</a>
    <input type="text" class="form-control collapse" id="collapseTwo">
  </div>

Fiddle Showing Both

Hope this helps.

C++ Best way to get integer division and remainder

You can use a modulus to get the remainder. Though @cnicutar's answer seems cleaner/more direct.

Direct casting vs 'as' operator?

According to experiments run on this page: http://www.dotnetguru2.org/sebastienros/index.php/2006/02/24/cast_vs_as

(this page is having some "illegal referrer" errors show up sometimes, so just refresh if it does)

Conclusion is, the "as" operator is normally faster than a cast. Sometimes by many times faster, sometimes just barely faster.

I peronsonally thing "as" is also more readable.

So, since it is both faster and "safer" (wont throw exception), and possibly easier to read, I recommend using "as" all the time.

CSS list-style-image size

Thanks to Chris for the starting point here is a improvement which addresses the resizing of the images used, the use of first-child is just to indicate you could use a variety of icons within the list to give you full control.

ul li:first-child:before {
    content: '';
    display: inline-block;
    height: 25px;
    width: 35px;
    background-image: url('../images/Money.png');
    background-size: contain;
    background-repeat: no-repeat;
    margin-left: -35px;
}

This seems to work well in all modern browsers, you will need to ensure that the width and the negative margin left have the same value, hope it helps

Converting NSData to NSString in Objective c

-[NSString initWithData:encoding] will return nil if the specified encoding doesn't match the data's encoding.

Make sure your data is encoded in UTF-8 (or change NSUTF8StringEncoding to whatever encoding that's appropriate for the data).

Print content of JavaScript object?

If you are using Firefox, alert(object.toSource()) should suffice for simple debugging purposes.

Errors in SQL Server while importing CSV file despite varchar(MAX) being used for each column

This answer may not apply universally, but it fixed the occurrence of this error I was encountering when importing a small text file. The flat file provider was importing based on fixed 50-character text columns in the source, which was incorrect. No amount of remapping the destination columns affected the issue.

To solve the issue, in the "Choose a Data Source" for the flat-file provider, after selecting the file, a "Suggest Types.." button appears beneath the input column list. After hitting this button, even if no changes were made to the enusing dialog, the Flat File provider then re-queried the source .csv file and then correctly determined the lengths of the fields in the source file.

Once this was done, the import proceeded with no further issues.

When & why to use delegates?

Delegates are extremely useful when wanting to declare a block of code that you want to pass around. For example when using a generic retry mechanism.

Pseudo:

function Retry(Delegate func, int numberOfTimes)
    try
    {
       func.Invoke();
    }
    catch { if(numberOfTimes blabla) func.Invoke(); etc. etc. }

Or when you want to do late evaluation of code blocks, like a function where you have some Transform action, and want to have a BeforeTransform and an AfterTransform action that you can evaluate within your Transform function, without having to know whether the BeginTransform is filled, or what it has to transform.

And of course when creating event handlers. You don't want to evaluate the code now, but only when needed, so you register a delegate that can be invoked when the event occurs.

Create table with jQuery - append

Following is done for multiple file uploads using jquery:

File input button:

<div>
 <input type="file" name="uploadFiles" id="uploadFiles" multiple="multiple" class="input-xlarge" onchange="getFileSizeandName(this);"/> 
</div>

Displaying File name and File size in a table:

<div id="uploadMultipleFilediv">
<table id="uploadTable" class="table table-striped table-bordered table-condensed"></table></div>

Javascript for getting the file name and file size:

function getFileSizeandName(input)
{
    var select = $('#uploadTable');
    //select.empty();
    var totalsizeOfUploadFiles = "";
    for(var i =0; i<input.files.length; i++)
    {
        var filesizeInBytes = input.files[i].size; // file size in bytes
        var filesizeInMB = (filesizeInBytes / (1024*1024)).toFixed(2); // convert the file size from bytes to mb
        var filename = input.files[i].name;
        select.append($('<tr><td>'+filename+'</td><td>'+filesizeInMB+'</td></tr>'));
        totalsizeOfUploadFiles = totalsizeOfUploadFiles+filesizeInMB;
        //alert("File name is : "+filename+" || size : "+filesizeInMB+" MB || size : "+filesizeInBytes+" Bytes");               
    }           
}

SQLAlchemy equivalent to SQL "LIKE" statement

Each column has like() method, which can be used in query.filter(). Given a search string, add a % character on either side to search as a substring in both directions.

tag = request.form["tag"]
search = "%{}%".format(tag)
posts = Post.query.filter(Post.tags.like(search)).all()

MySQL - Operand should contain 1 column(s)

Your subquery is selecting two columns, while you are using it to project one column (as part of the outer SELECT clause). You can only select one column from such a query in this context.

Consider joining to the users table instead; this will give you more flexibility when selecting what columns you want from users.

SELECT
topics.id,
topics.name,
topics.post_count,
topics.view_count,
COUNT( posts.solved_post ) AS solved_post,
users.username AS posted_by,
users.id AS posted_by_id

FROM topics

LEFT OUTER JOIN posts ON posts.topic_id = topics.id
LEFT OUTER JOIN users ON users.id = posts.posted_by

WHERE topics.cat_id = :cat
GROUP BY topics.id

mysqldump & gzip commands to properly create a compressed file of a MySQL database using crontab

Besides the solution of m79lkm above, my 2 cents on this topic is not to directly pipe the result in gzip but first dump it as a .sql file, and then gzip it. (Use && instead of | )

The dump itself will be faster. (for what I tested it was double as fast)

Otherwise you tables will be locked longer and the downtime/slow-responding of your application can bother the users. The mysqldump command is taking a lot of resources from your server.

So I would go for "&& gzip" instead of "| gzip"

Important: check for free disk space first with df -h since you will need more then piping | gzip.

mysqldump -u user -p[user_password] [database_name] > dumpfilename.sql && gzip dumpfilename.sql

-> which will also result in 1 file called dumpfilename.sql.gz

Furthermore the option --single-transaction prevents the tables being locked but still result in a solid backup. So you might consider to use that option. See docs here

mysqldump --single-transaction -u user -p[user_password] [database_name] > dumpfilename.sql && gzip dumpfilename.sql

Right way to reverse a pandas DataFrame?

None of the existing answers resets the index after reversing the dataframe.

For this, do the following:

 data[::-1].reset_index()

Here's a utility function that also removes the old index column, as per @Tim's comment:

def reset_my_index(df):
  res = df[::-1].reset_index(drop=True)
  return(res)

Simply pass your dataframe into the function

Your branch is ahead of 'origin/master' by 3 commits

$ git fetch

  - remote: Enumerating objects: 3, done.
  - remote: Counting objects: 100% (3/3), done.
  - remote: Compressing objects: 100% (3/3), done.
  - remote: Total 3 (delta 0), reused 0 (delta 0), pack-reused 0


$ git pull 

   - Already up to date!
   - Merge made by the 'recursive' strategy.

finally:

$ git push origin

How to display a list of images in a ListView in Android?

We need to implement two layouts. One to hold listview and another to hold row item of listview. Implement your own custom adapter. Idea is to include one textview and one imageview.

public View getView(int position, View convertView, ViewGroup parent) {
 // TODO Auto-generated method stub
 LayoutInflater inflater = (LayoutInflater) context
 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 View single_row = inflater.inflate(R.layout.list_row, null,
 true);
 TextView textView = (TextView) single_row.findViewById(R.id.textView);
 ImageView imageView = (ImageView) single_row.findViewById(R.id.imageView);
 textView.setText(color_names[position]);
 imageView.setImageResource(image_id[position]);
 return single_row; 
 }

Next we implement functionality in main activity to include images and text data dynamically during runtime. You can pass dynamically created text array and image id array to the constructor of custom adapter.

Customlistadapter adapter = new Customlistadapter(this, image_id, text_name);

How to focus on a form input text field on page load using jQuery?

Sure:

<head>
    <script src="jquery-1.3.2.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(function() {
            $("#myTextBox").focus();
        });
    </script>
</head>
<body>
    <input type="text" id="myTextBox">
</body>

Download Excel file via AJAX MVC

$.ajax({
                type: "GET",
                url: "/Home/Downloadexcel/",
                contentType: "application/json; charset=utf-8",
                data: null,
                success: function (Rdata) {
                    debugger;
                    var bytes = new Uint8Array(Rdata.FileContents); 
                    var blob = new Blob([bytes], { type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" });
                    var link = document.createElement('a');
                    link.href = window.URL.createObjectURL(blob);
                    link.download = "myFileName.xlsx";
                    link.click();
                },
                error: function (err) {

                }

            });

Java Reflection Performance

"Significant" is entirely dependent on context.

If you're using reflection to create a single handler object based on some configuration file, and then spending the rest of your time running database queries, then it's insignificant. If you're creating large numbers of objects via reflection in a tight loop, then yes, it's significant.

In general, design flexibility (where needed!) should drive your use of reflection, not performance. However, to determine whether performance is an issue, you need to profile rather than get arbitrary responses from a discussion forum.

How can I insert multiple rows into oracle with a sequence value?

insert into TABLE_NAME
(COL1,COL2)
WITH
data AS
(
    select 'some value'    x from dual
    union all
    select 'another value' x from dual
)
SELECT my_seq.NEXTVAL, x 
FROM data
;

I think that is what you want, but i don't have access to oracle to test it right now.

SQL Server String or binary data would be truncated

I had a similar issue. I was copying data from one table to an identical table in everything but name.

Eventually I dumped the source table into a temp table using a SELECT INTO statement.

SELECT *
INTO TEMP_TABLE
FROM SOURCE_TABLE;

I compared the schema of the source table to temp table. I found one of the columns was a varchar(4000) when I was expecting a varchar(250).

UPDATE: The varchar(4000) issue can be explained here in case you are interested:

For Nvarchar(Max) I am only getting 4000 characters in TSQL?

Hope this helps.

Android toolbar center title and custom font

I found another way to add custom toolbar without any adicional Java/Kotlin code.

  • First: create a XML with your custom toolbar layout with AppBarLayout as the parent:

    <?xml version="1.0" encoding="utf-8"?>
    <android.support.design.widget.AppBarLayout                     
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">
    
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay">
    
        <ImageView
            android:layout_width="80dp"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:layout_marginEnd="@dimen/magin_default"
            android:src="@drawable/logo" />
    
    </android.support.v7.widget.Toolbar>
    

  • Second: Include the toolbar in your layout:

    <?xml version="1.0" encoding="utf-8"?>                
    <android.support.constraint.ConstraintLayout 
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/blue"
        tools:context=".app.MainAcitivity"
        tools:layout_editor_absoluteY="81dp">
    
        <include
            layout="@layout/toolbar_inicio"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <!-- Put your layout here -->
    
    </android.support.constraint.ConstraintLayout>
    

How can I change the image displayed in a UIImageView programmatically?

Working with Swift 5 (XCode 10.3) it's just

yourImageView.image = UIImage(named: "nameOfTheImage")

Type.GetType("namespace.a.b.ClassName") returns null

You can also get the type without assembly qualified name but with the dll name also, for example:

Type myClassType = Type.GetType("TypeName,DllName");

I had the same situation and it worked for me. I needed an object of type "DataModel.QueueObject" and had a reference to "DataModel" so I got the type as follows:

Type type = Type.GetType("DataModel.QueueObject,DataModel");

The second string after the comma is the reference name (dll name).

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in

use global scope on your $con and put it inside your getPosts() function like so.

function getPosts() {
global $con;
$query = mysqli_query($con,"SELECT * FROM Blog");
while($row = mysqli_fetch_array($query))
    {
        echo "<div class=\"blogsnippet\">";
        echo "<h4>" . $row['Title'] . "</h4>" . $row['SubHeading'];
        echo "</div>";
    }
}

What is the difference between compileSdkVersion and targetSdkVersion?

The Application settings of an Android project's properties in Visual Studio 2017 (15.8.5) has them combined:

enter image description here

Test class with a new() call in it with Mockito

In situations where the class under test can be modified and when it's desirable to avoid byte code manipulation, to keep things fast or to minimise third party dependencies, here is my take on the use of a factory to extract the new operation.

public class TestedClass {

    interface PojoFactory { Pojo getNewPojo(); }

    private final PojoFactory factory;

    /** For use in production - nothing needs to change. */
    public TestedClass() {
        this.factory = new PojoFactory() {
            @Override
            public Pojo getNewPojo() {
                return new Pojo();
            }
        };
    }

    /** For use in testing - provide a pojo factory. */
    public TestedClass(PojoFactory factory) {
        this.factory = factory;
    }

    public void doSomething() {
        Pojo pojo = this.factory.getNewPojo();
        anythingCouldHappen(pojo);
    }
}

With this in place, your testing, asserts and verify calls on the Pojo object are easy:

public  void testSomething() {
    Pojo testPojo = new Pojo();
    TestedClass target = new TestedClass(new TestedClass.PojoFactory() {
                @Override
                public Pojo getNewPojo() {
                    return testPojo;
                }
            });
    target.doSomething();
    assertThat(testPojo.isLifeStillBeautiful(), is(true));
}

The only downside to this approach potentially arises if TestClass has multiple constructors which you'd have to duplicate with the extra parameter.

For SOLID reasons you'd probably want to put the PojoFactory interface onto the Pojo class instead, and the production factory as well.

public class Pojo {

    interface PojoFactory { Pojo getNewPojo(); }

    public static final PojoFactory productionFactory = 
        new PojoFactory() {
            @Override 
            public Pojo getNewPojo() {
                return new Pojo();
            }
        };

Docker is in volume in use, but there aren't any Docker containers

You should type this command with flag -f (force):

sudo docker volume rm -f <VOLUME NAME>