Programs & Examples On #Http status code 500

Please DO NOT USE THIS TAG. It is meaningless for categorizing your question.

The localhost page isn’t working localhost is currently unable to handle this request. HTTP ERROR 500

Such kind of error normally happens when you try using functions like php_info() wrongly.

<?php 
     php_info(); // 500 error
     phpinfo(); // Works correctly
?>

A close look at your code will be better.

OpenSSL: unable to verify the first certificate for Experian URL

The first error message is telling you more about the problem:

verify error:num=20:unable to get local issuer certificate

The issuing certificate authority of the end entity server certificate is

VeriSign Class 3 Secure Server CA - G3

Look closely in your CA file - you will not find this certificate since it is an intermediary CA - what you found was a similar-named G3 Public Primary CA of VeriSign.

But why does the other connection succeed, but this one doesn't? The problem is a misconfiguration of the servers (see for yourself using the -debug option). The "good" server sends the entire certificate chain during the handshake, therefore providing you with the necessary intermediate certificates.

But the server that is failing sends you only the end entity certificate, and OpenSSL is not capable of downloading the missing intermediate certificate "on the fly" (which would be possible by interpreting the Authority Information Access extension). Therefore your attempt fails using s_client but it would succeed nevertheless if you browse to the same URL using e.g. FireFox (which does support the "certificate discovery" feature).

Your options to solve the problem are either fixing this on the server side by making the server send the entire chain, too, or by passing the missing intermediate certificate to OpenSSL as a client-side parameter.

babel-loader jsx SyntaxError: Unexpected token

This works perfect for me

{
    test: /\.(js|jsx)$/,
    loader: 'babel-loader',
    exclude: /node_modules/,
    query: {
        presets: ['es2015','react']
    }
},

What is &amp used for

HTML doesn't recognize the & but it will recognize &amp; because it is equal to & in HTML

I looked over this post someone had made: http://www.webmasterworld.com/forum21/8851.htm

How can I check the extension of a file?

import os
source = ['test_sound.flac','ts.mp3']

for files in source:
   fileName,fileExtension = os.path.splitext(files)
   print fileExtension   # Print File Extensions
   print fileName   # It print file name

How can we generate getters and setters in Visual Studio?

You can also use "propfull" and hit TAB twice.

The variable and property with get and set will be generated.

Difference in Months between two dates in JavaScript

Calculate the difference between two dates include fraction of month (days).


var difference = (date2.getDate() - date1.getDate()) / 30 +
    date2.getMonth() - date1.getMonth() +
    (12 * (date2.getFullYear() - date1.getFullYear()));

For example:
date1: 24/09/2015 (24th Sept 2015)
date2: 09/11/2015 (9th Nov 2015)
the difference: 2.5 (months)

Using Composer's Autoload

There also other ways to use the composer autoload features. Ways that can be useful to load packages without namespaces or packages that come with a custom autoload function.

For example if you want to include a single file that contains an autoload function as well you can use the "files" directive as follows:

"autoload": {
    "psr-0": {
        "": "src/",
        "SymfonyStandard": "app/"
    },
    "files": ["vendor/wordnik/wordnik-php/wordnik/Swagger.php"]
},

And inside the Swagger.php file we got:

function swagger_autoloader($className) {
    $currentDir = dirname(__FILE__);
    if (file_exists($currentDir . '/' . $className . '.php')) {
        include $currentDir . '/' . $className . '.php';
    } elseif (file_exists($currentDir . '/models/' . $className . '.php')) {
        include $currentDir . '/models/' . $className . '.php';
    }
}
spl_autoload_register('swagger_autoloader');

https://getcomposer.org/doc/04-schema.md#files

Otherwise you may want to use a classmap reference:

{
    "autoload": {
        "classmap": ["src/", "lib/", "Something.php"]
    }
}

https://getcomposer.org/doc/04-schema.md#classmap

Note: during your tests remember to launch the composer dump-autoload command or you won't see any change!

./composer.phar dump-autoload

Happy autoloading =)

XMLHttpRequest module not defined/found

XMLHttpRequest is a built-in object in web browsers.

It is not distributed with Node; you have to install it separately,

  1. Install it with npm,

    npm install xmlhttprequest
    
  2. Now you can require it in your code.

    var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
    var xhr = new XMLHttpRequest();
    

That said, the http module is the built-in tool for making HTTP requests from Node.

Axios is a library for making HTTP requests which is available for Node and browsers that is very popular these days.

C# version of java's synchronized keyword?

static object Lock = new object();

lock (Lock) 
{
// do stuff
}

Will using 'var' affect performance?

If the compiler can do automatic type inferencing, then there wont be any issue with performance. Both of these will generate same code

var    x = new ClassA();
ClassA x = new ClassA();

however, if you are constructing the type dynamically (LINQ ...) then var is your only question and there is other mechanism to compare to in order to say what is the penalty.

Playing MP4 files in Firefox using HTML5 video

I can confirm that mp4 just will not work in the video tag. No matter how much you try to mess with the type tag and the codec and the mime types from the server.

Crazy, because for the same exact video, on the same test page, the old embed tag for an mp4 works just fine in firefox. I spent all yesterday messing with this. Firefox is like IE all of a sudden, hours and hours of time, not billable. Yay.

Speaking of IE, it fails FAR MORE gracefully on this. When it can't match up the format it falls to the content between the tags, so it is possible to just put video around object around embed and everything works great. Firefox, nope, despite failing, it puts up the poster image (greyed out so that isn't even useful as a fallback) with an error message smack in the middle. So now the options are put in browser recognition code (meaning we've gained nothing on embedding videos in the last ten years) or ditch html5.

Checking for empty or null JToken in a JObject

You can proceed as follows to check whether a JToken Value is null

JToken token = jObject["key"];

if(token.Type == JTokenType.Null)
{
    // Do your logic
}

Why I can't access remote Jupyter Notebook server?

I faced a similar issue, and I solved that after doing the following:

  1. check your jupyter configuration file: this is described here in details; https://testnb.readthedocs.io/en/stable/examples/Notebook/Configuring%20the%20Notebook%20and%20Server.html

-- you will simply need from the link above to learn how to make jupyter server listens to your local machin IP -- you will need to know your local machin IP (i use "ifconfig -a" on ubuntu to find that out) - please check for centos6

after you finish setting your configuration, you can run jupyter notebook at your local IP: jupyter notebook --ip=* --no-browser

please replace * with your IP address for example: jupyter notebook --ip=192.168.x.x --no-browser

you can now access your jupyter server from any device connected to the router using this ip:port (the port is usually 8888, so for my case for instance I used "192.168.x.x:8888" to access my server from other devices)

now if you want to access this server from public IP, you will have to:

  1. find your public IP (simply type on google what is my IP)
  2. use this IP address instead of your local IP to access the server from any device not connected to the same router kindly note: if your linux server runs on Virtual machine, you will need to set your router to allow accessing your VB from public IPs, settings depends on the router type. otherwise, you should be able to access the server using the public IP and the port set for it from any device not connected to your router, or using your local IP and the port set from any device connected to the same router!

Git Bash doesn't see my PATH

I've run into a stupid mistake on my part. I had a systems wide and a user variable path set for my golang workspace on my windows 10 machine. When I removed the redundant systems variable pathway and logged off and back on, I was able to call .exe files in bash and call go env with success.

Although OP has been answered this is another problem that could keep bash from seeing your pathways. I just tested bash again with this problem and it does seem to give a conflict of some sort that blocks bash from following either of the paths.

Bootstrap 3 collapsed menu doesn't close on click

I am having/had similar issues with Bootstrap 4, alpha-6, and Joakim Johanssons answer above started me in the right direction. No javascript required. Putting data-target=".navbar-collapse" and data-toggle="collapse" into the div tag inside the nav, but surrounding the links/buttons, worked for me.

_x000D_
_x000D_
<div class="navbar-nav" data-target=".navbar-collapse" data-toggle="collapse">_x000D_
   <a class="nav-item nav-link" href="#">Menu Item 1</a>_x000D_
   ..._x000D_
</div>
_x000D_
_x000D_
_x000D_

WordPress asking for my FTP credentials to install plugins

"Whenever you use the WordPress control panel to automatically install, upgrade, or delete plugins, WordPress must make changes to files on the filesystem.

Before making any changes, WordPress first checks to see whether or not it has access to directly manipulate the file system.

If WordPress does not have the necessary permissions to modify the filesystem directly, you will be asked for FTP credentials so that WordPress can try to do what it needs to via FTP."

Solution: In order to find out what user your instance of apache is running as, create a test script with the following content:

<?php echo(exec("whoami")); ?>

For me, it was daemon and not www-data. Then, fix the permission by:

sudo chown -R daemon /path/to/your/local/www/folder

'invalid value encountered in double_scalars' warning, possibly numpy

Zero-size array passed to numpy.mean raises this warning (as indicated in several comments).

For some other candidates:

  • median also raises this warning on zero-sized array.

other candidates do not raise this warning:

  • min,argmin both raise ValueError on empty array
  • randn takes *arg; using randn(*[]) returns a single random number
  • std,var return nan on an empty array

java.net.UnknownHostException: Invalid hostname for server: local

Your hostname is missing. JBoss uses this environment variable ($HOSTNAME) when it connects to the server.

[root@xyz ~]# echo $HOSTNAME
xyz

[root@xyz ~]# ping $HOSTNAME
ping: unknown host xyz

[root@xyz ~]# hostname -f
hostname: Unknown host

There are dozens of things that can cause this. Please comment if you discover a new reason.

For a hack until you can permanently resolve this issue on your server, you can add a line to the end of your /etc/hosts file:

127.0.0.1 xyz.xxx.xxx.edu xyz

Send email using the GMail SMTP server from a PHP page

I have a solution for GSuite accounts that doesnt have the "@gmail.com" sufix. Also I think it will work for GSuite accounts with the @gmail.com but havent tried it. First you should have the privileges to change the option "allos¿w less secure app" for your GSuite account. If you have the privileges (you can check in account settings->security) then you have to deactivate "two step factor authentication" go to the end of the page and set to "yes" for allow less secure applications. That's all. If you dont have privileges to change those options the solution for this thread will not work. Check https://support.google.com/a/answer/6260879?hl=en to make changes to "allow less..." option.

How to do select from where x is equal to multiple values?

You can try using parentheses around the OR expressions to make sure your query is interpreted correctly, or more concisely, use IN:

SELECT ads.*, location.county 
FROM ads
LEFT JOIN location ON location.county = ads.county_id
WHERE ads.published = 1 
AND ads.type = 13
AND ads.county_id IN (2,5,7,9)

How to change link color (Bootstrap)

For a direct change, you can use Bootstrap classes in the <a> tag (it won't work in the <div>):

<h4 class="text-center"><a class="text-warning" href="#">Your text</a></h4>

iPhone viewWillAppear not firing

In case this helps anyone. I had a similar problem where my ViewWillAppear is not firing on a UITableViewController. After a lot of playing around, I realized that the problem was that the UINavigationController that is controlling my UITableView is not on the root view. Once I fix that, it is now working like a champ.

How to find index of STRING array in Java from a given value?

String carName = // insert code here
int index = -1;
for (int i=0;i<TYPES.length;i++) {
    if (TYPES[i].equals(carName)) {
        index = i;
        break;
    }
}

After this index is the array index of your car, or -1 if it doesn't exist.

Create an Excel file using vbscripts

set objExcel = CreateObject("Excel.Application")
objExcel.Application.DisplayAlerts = False
set objWorkbook=objExcel.workbooks.add()
objExcel.cells(1,1).value = "Test value"
objExcel.cells(1,2).value = "Test data"
objWorkbook.Saveas "c:\testXLS.xls"
objWorkbook.Close
objExcel.workbooks.close
objExcel.quit
set objExcel = nothing `

Using python's mock patch.object to change the return value of a method called within another method

To add to Silfheed's answer, which was useful, I needed to patch multiple methods of the object in question. I found it more elegant to do it this way:

Given the following function to test, located in module.a_function.to_test.py:

from some_other.module import SomeOtherClass

def add_results():
    my_object = SomeOtherClass('some_contextual_parameters')
    result_a = my_object.method_a()
    result_b = my_object.method_b()
    
    return result_a + result_b

To test this function (or class method, it doesn't matter), one can patch multiple methods of the class SomeOtherClass by using patch.object() in combination with sys.modules:

@patch.object(sys.modules['module.a_function.to_test'], 'SomeOtherClass')
def test__should_add_results(self, mocked_other_class):
  mocked_other_class().method_a.return_value = 4
  mocked_other_class().method_b.return_value = 7

  self.assertEqual(add_results(), 11)

This works no matter the number of methods of SomeOtherClass you need to patch, with independent results.

Also, using the same patching method, an actual instance of SomeOtherClass can be returned if need be:

@patch.object(sys.modules['module.a_function.to_test'], 'SomeOtherClass')
def test__should_add_results(self, mocked_other_class):
  other_class_instance = SomeOtherClass('some_controlled_parameters')
  mocked_other_class.return_value = other_class_instance 
  ...

GET and POST methods with the same Action name in the same Controller

You can't have multiple actions with the same name. You could add a parameter to one method and that would be valid. For example:

    public ActionResult Index(int i)
    {
        Some Code--Some Code---Some Code
        return View();
    }

There are a few ways to do to have actions that differ only by request verb. My favorite and, I think, the easiest to implement is to use the AttributeRouting package. Once installed simply add an attribute to your method as follows:

  [GET("Resources")]
  public ActionResult Index()
  {
      return View();
  }

  [POST("Resources")]
  public ActionResult Create()
  {
      return RedirectToAction("Index");
  }

In the above example the methods have different names but the action name in both cases is "Resources". The only difference is the request verb.

The package can be installed using NuGet like this:

PM> Install-Package AttributeRouting

If you don't want the dependency on the AttributeRouting packages you could do this by writing a custom action selector attribute.

How can I display my windows user name in excel spread sheet using macros?

Range("A1").value = Environ("Username")

This is better than Application.Username, which doesn't always supply the Windows username. Thanks to Kyle for pointing this out.

  • Application Username is the name of the User set in Excel > Tools > Options
  • Environ("Username") is the name you registered for Windows; see Control Panel >System

Remove characters from a string

Using replace() with regular expressions is the most flexible/powerful. It's also the only way to globally replace every instance of a search pattern in JavaScript. The non-regex variant of replace() will only replace the first instance.

For example:

var str = "foo gar gaz";

// returns: "foo bar gaz"
str.replace('g', 'b');

// returns: "foo bar baz"
str = str.replace(/g/gi, 'b');

In the latter example, the trailing /gi indicates case-insensitivity and global replacement (meaning that not just the first instance should be replaced), which is what you typically want when you're replacing in strings.

To remove characters, use an empty string as the replacement:

var str = "foo bar baz";

// returns: "foo r z"
str.replace(/ba/gi, '');

jQuery: how to scroll to certain anchor/div on page load?

Just append #[id of the div you want to scroll to] to your page url. For example, if I wanted to scroll to the copyright section of this stackoverflow question, the URL would change from

http://stackoverflow.com/questions/9757625/jquery-how-to-scroll-to-certain-anchor-div-on-page-load

to

http://stackoverflow.com/questions/9757625/jquery-how-to-scroll-to-certain-anchor-div-on-page-load#copyright

notice the #copyright at the end of the URL.

Empty responseText from XMLHttpRequest

Had a similar problem to yours. What we had to do is use the document.domain solution found here:

Ways to circumvent the same-origin policy

We also needed to change thins on the web service side. Used the "Access-Control-Allow-Origin" header found here:

https://developer.mozilla.org/En/HTTP_access_control

What is the use of ByteBuffer in Java?

This is a good description of its uses and shortcomings. You essentially use it whenever you need to do fast low-level I/O. If you were going to implement a TCP/IP protocol or if you were writing a database (DBMS) this class would come in handy.

How do I view the SQL generated by the Entity Framework?

There are two ways:

  1. To view the SQL that will be generated, simply call ToTraceString(). You can add it into your watch window and set a breakpoint to see what the query would be at any given point for any LINQ query.
  2. You can attach a tracer to your SQL server of choice, which will show you the final query in all its gory detail. In the case of MySQL, the easiest way to trace the queries is simply to tail the query log with tail -f. You can learn more about MySQL's logging facilities in the official documentation. For SQL Server, the easiest way is to use the included SQL Server profiler.

How to check if a string contains only digits in Java

We can use either Pattern.compile("[0-9]+.[0-9]+") or Pattern.compile("\\d+.\\d+"). They have the same meaning.

the pattern [0-9] means digit. The same as '\d'. '+' means it appears more times. '.' for integer or float.

Try following code:

import java.util.regex.Pattern;

    public class PatternSample {

        public boolean containNumbersOnly(String source){
            boolean result = false;
            Pattern pattern = Pattern.compile("[0-9]+.[0-9]+"); //correct pattern for both float and integer.
            pattern = Pattern.compile("\\d+.\\d+"); //correct pattern for both float and integer.

            result = pattern.matcher(source).matches();
            if(result){
                System.out.println("\"" + source + "\""  + " is a number");
            }else
                System.out.println("\"" + source + "\""  + " is a String");
            return result;
        }

        public static void main(String[] args){
            PatternSample obj = new PatternSample();
            obj.containNumbersOnly("123456.a");
            obj.containNumbersOnly("123456 ");
            obj.containNumbersOnly("123456");
            obj.containNumbersOnly("0123456.0");
            obj.containNumbersOnly("0123456a.0");
        }

    }

Output:

"123456.a" is a String
"123456 " is a String
"123456" is a number
"0123456.0" is a number
"0123456a.0" is a String

How to detect chrome and safari browser (webkit)

Many answers here. Here is my first consideration.

Without JavaScript, including the possibility Javascript is initially disabled by the user in his browser for security purposes, to be white listed by the user if the user trusts the site, DOM will not be usable because Javascript is off.

Programmatically, you are left with a backend server-side or frontend client-side consideration.

With the backend, you can use common denominator HTTP "User-Agent" request header and/or any possible proprietary HTTP request header issued by the browser to output browser specific HTML stuff.

With the client site, you may want to enforce Javascript to allow you to use DOM. If so, then you probably will want to first use the following in your HTML page:

<noscript>This site requires Javascript. Please turn on Javascript.</noscript>

While we are heading to a day with every web coder will be dependent on Javascript in some way (or not), today, to presume every user has javascript enabled would be design and product development QA mistake.

I've seen far too may sites who end up with a blank page or the site breaks down because it presumed every user has javascript enabled. No. For security purposes, they may have Javascript initially off and some browsers, like Chrome, will allow the user to white list the web site on a domain by domain basis. Edge is the only browser I am aware of where Microsoft made the decision to completely disable the user's ability to turn off Javascript. Edge doesn't offer a white listing concept hence it is one reason I don't personally use Edge.

Using the tag is a simple way to inform the user your site won't work without Javascript. Once the user turns it on and refreshes/reload the page, DOM is now available to use the techniques cited by the thread replies to detect chrome vs safari.

Ironically, I got here because I was updating by platform and google the same basic question; chrome vs sarafi. I didn't know Chrome creates a DOM object named "chrome" which is really all you need to detect "chrome" vs everything else.

var isChrome = typeof(chrome) === "object";

If true, you got Chrome, if false, you got some other browser.

Check to see if Safari create its own DOM object as well, if so, get the object name and do the same thing, for example:

var isSafari = (typeof(safari) === "object");

Hope these tips help.

Django Multiple Choice Field / Checkbox Select Multiple

The profile choices need to be setup as a ManyToManyField for this to work correctly.

So... your model should be like this:

class Choices(models.Model):
  description = models.CharField(max_length=300)

class Profile(models.Model):
  user = models.ForeignKey(User, blank=True, unique=True, verbose_name='user')
  choices = models.ManyToManyField(Choices)

Then, sync the database and load up Choices with the various options you want available.

Now, the ModelForm will build itself...

class ProfileForm(forms.ModelForm):
  Meta:
    model = Profile
    exclude = ['user']

And finally, the view:

if request.method=='POST':
  form = ProfileForm(request.POST)
  if form.is_valid():
    profile = form.save(commit=False)
    profile.user = request.user
    profile.save()
else:
  form = ProfileForm()

return render_to_response(template_name, {"profile_form": form}, context_instance=RequestContext(request))

It should be mentioned that you could setup a profile in a couple different ways, including inheritance. That said, this should work for you as well.

Good luck.

Splitting a string into separate variables

Foreach-object operation statement:

$a,$b = 'hi.there' | foreach split .
$a,$b

hi
there

Pandas "Can only compare identically-labeled DataFrame objects" error

At the time when this question was asked there wasn't another function in Pandas to test equality, but it has been added a while ago: pandas.equals

You use it like this:

df1.equals(df2)

Some differenes to == are:

  • You don't get the error described in the question
  • It returns a simple boolean.
  • NaN values in the same location are considered equal
  • 2 DataFrames need to have the same dtype to be considered equal, see this stackoverflow question

Get single row result with Doctrine NativeQuery

I use fetchObject() here a small example using Symfony 4.4

    <?php 
    use Doctrine\DBAL\Driver\Connection;

    class MyController{

    public function index($username){
      $queryBuilder = $connection->createQueryBuilder();
      $queryBuilder
        ->select('id', 'name')
        ->from('app_user')
        ->where('name = ?')
        ->setParameter(0, $username)
        ->setMaxResults(1);
      $stmUser = $queryBuilder->execute();

      dump($stmUser->fetchObject());

      //get_class_methods($stmUser) -> to see all methods
    }
  }

Response:

{ 
"id": "2", "name":"myuser"
}

How can I keep a container running on Kubernetes?

My few cents on the subject. Assuming that kubectl is working then the closest command that would be equivalent to the docker command that you mentioned in your question, would be something like this.

$ kubectl run ubuntu --image=ubuntu --restart=Never --command sleep infinity

Above command will create a single Pod in default namespace and, it will execute sleep command with infinity argument -this way you will have a process that runs in foreground keeping container alive.

Afterwords, you can interact with Pod by running kubectl exec command.

$ kubectl exec ubuntu -it -- bash

This technique is very useful for creating a Pod resource and ad-hoc debugging.

Injecting $scope into an angular service function()

Instead of trying to modify the $scope within the service, you can implement a $watch within your controller to watch a property on your service for changes and then update a property on the $scope. Here is an example you might try in a controller:

angular.module('cfd')
    .controller('MyController', ['$scope', 'StudentService', function ($scope, StudentService) {

        $scope.students = null;

        (function () {
            $scope.$watch(function () {
                return StudentService.students;
            }, function (newVal, oldVal) {
                if ( newValue !== oldValue ) {
                    $scope.students = newVal;
                }
            });
        }());
    }]);

One thing to note is that within your service, in order for the students property to be visible, it needs to be on the Service object or this like so:

this.students = $http.get(path).then(function (resp) {
  return resp.data;
});

What causes java.lang.IncompatibleClassChangeError?

While these answers are all correct, resolving the problem is often more difficult. It's generally the result of two mildly different versions of the same dependency on the classpath, and is almost always caused by either a different superclass than was originally compiled against being on the classpath or some import of the transitive closure being different, but generally at class instantiation and constructor invocation. (After successful class loading and ctor invocation, you'll get NoSuchMethodException or whatnot.)

If the behavior appears random, it's likely the result of a multithreaded program classloading different transitive dependencies based on what code got hit first.

To resolve these, try launching the VM with -verbose as an argument, then look at the classes that were being loaded when the exception occurs. You should see some surprising information. For instance, having multiple copies of the same dependency and versions you never expected or would have accepted if you knew they were being included.

Resolving duplicate jars with Maven is best done with a combination of the maven-dependency-plugin and maven-enforcer-plugin under Maven (or SBT's Dependency Graph Plugin, then adding those jars to a section of your top-level POM or as imported dependency elements in SBT (to remove those dependencies).

Good luck!

How to make Excel VBA variables available to multiple macros?

Declare them outside the subroutines, like this:

Public wbA as Workbook
Public wbB as Workbook
Sub MySubRoutine()
    Set wbA = Workbooks.Open("C:\file.xlsx")
    Set wbB = Workbooks.Open("C:\file2.xlsx")
    OtherSubRoutine
End Sub
Sub OtherSubRoutine()
    MsgBox wbA.Name, vbInformation
End Sub

Alternately, you can pass variables between subroutines:

Sub MySubRoutine()
Dim wbA as Workbook
Dim wbB as Workbook
    Set wbA = Workbooks.Open("C:\file.xlsx")
    Set wbB = Workbooks.Open("C:\file2.xlsx")
    OtherSubRoutine wbA, wbB
End Sub
Sub OtherSubRoutine(wb1 as Workbook, wb2 as Workbook)
    MsgBox wb1.Name, vbInformation
    MsgBox wb2.Name, vbInformation
End Sub

Or use Functions to return values:

Sub MySubroutine()
    Dim i as Long
    i = MyFunction()
    MsgBox i
End Sub
Function MyFunction()
    'Lots of code that does something
    Dim x As Integer, y as Double
    For x = 1 to 1000
        'Lots of code that does something
    Next
    MyFunction = y
End Function

In the second method, within the scope of OtherSubRoutine you refer to them by their parameter names wb1 and wb2. Passed variables do not need to use the same names, just the same variable types. This allows you some freedom, for example you have a loop over several workbooks, and you can send each workbook to a subroutine to perform some action on that Workbook, without making all (or any) of the variables public in scope.

A Note About User Forms

Personally I would recommend keeping Option Explicit in all of your modules and forms (this prevents you from instantiating variables with typos in their names, like lCoutn when you meant lCount etc., among other reasons).

If you're using Option Explicit (which you should), then you should qualify module-scoped variables for style and to avoid ambiguity, and you must qualify user-form Public scoped variables, as these are not "public" in the same sense. For instance, i is undefined, though it's Public in the scope of UserForm1:

enter image description here

You can refer to it as UserForm1.i to avoid the compile error, or since forms are New-able, you can create a variable object to contain reference to your form, and refer to it that way:

enter image description here

NB: In the above screenshots x is declared Public x as Long in another standard code module, and will not raise the compilation error. It may be preferable to refer to this as Module2.x to avoid ambiguity and possible shadowing in case you re-use variable names...

You have not concluded your merge (MERGE_HEAD exists)

Try changing any temporary file. Like just remove any space or add space and then commit and push that file.

git add 'temporary_change_file'

git commit -m "git issue resolving"

git push origin develop

And then try git pull,

git pull origin develop

Hope this might help you.

How to open a new HTML page using jQuery?

use window.open("file2.html"); to open on new window,

or use window.location.href = "file2.html" to open on same window.

Why do we have to override the equals() method in Java?

Object.equals() method checks only reference of object not primitive data type or Object value (Wrapper class object of primitive data, simple primitive data type (byte, short, int, long etc.)). So that we must override equals() method when we compare object based on primitive data type.

LINQ where clause with lambda expression having OR clauses and null values returning incomplete results

You are checking Parent properties for null in your delegate. The same should work with lambda expressions too.

List<AnalysisObject> analysisObjects = analysisObjectRepository
        .FindAll()
        .Where(x => 
            (x.ID == packageId) || 
            (x.Parent != null &&
                (x.Parent.ID == packageId || 
                (x.Parent.Parent != null && x.Parent.Parent.ID == packageId)))
        .ToList();

Round double in two decimal places in C#?

Math.Round(inputValue, 2, MidpointRounding.AwayFromZero)

String comparison in bash. [[: not found

If you know you're on bash, and still get this error, make sure you write the if with spaces.

[[1==1]] # This outputs error

[[ 1==1 ]] # OK

How to compare two maps by their values

If you assume that there can be duplicate values the only way to do this is to put the values in lists, sort them and compare the lists viz:

List<String> values1 = new ArrayList<String>(map1.values());
List<String> values2 = new ArrayList<String>(map2.values());
Collections.sort(values1);
Collections.sort(values2);
boolean mapsHaveEqualValues = values1.equals(values2);

If values cannot contain duplicate values then you can either do the above without the sort using sets.

FormsAuthentication.SignOut() does not log the user out

Users can still browse your website because cookies are not cleared when you call FormsAuthentication.SignOut() and they are authenticated on every new request. In MS documentation is says that cookie will be cleared but they don't, bug? Its exactly the same with Session.Abandon(), cookie is still there.

You should change your code to this:

FormsAuthentication.SignOut();
Session.Abandon();

// clear authentication cookie
HttpCookie cookie1 = new HttpCookie(FormsAuthentication.FormsCookieName, "");
cookie1.Expires = DateTime.Now.AddYears(-1);
Response.Cookies.Add(cookie1);

// clear session cookie (not necessary for your current problem but i would recommend you do it anyway)
SessionStateSection sessionStateSection = (SessionStateSection)WebConfigurationManager.GetSection("system.web/sessionState");
HttpCookie cookie2 = new HttpCookie(sessionStateSection.CookieName, "");
cookie2.Expires = DateTime.Now.AddYears(-1);
Response.Cookies.Add(cookie2);

FormsAuthentication.RedirectToLoginPage();

HttpCookie is in the System.Web namespace. MSDN Reference.

Windows equivalent to UNIX pwd

Open notepad as administrator and write:

@echo %cd%

Save it in c:\windows\system32\ with the name "pwd.cmd" (be careful not to save pwd.cmd.txt)

Then you have the pwd command.

Android studio: emulator is running but not showing up in Run App "choose a running device"

in your device you want to run app on Go to settings About device >> Build number triple clicks or more and back to settings you will found "Developer options" appear go to and click on "USB debugging" Done

How can I solve Exception in thread "main" java.lang.NullPointerException error

This is the problem

double a[] = null;

Since a is null, NullPointerException will arise every time you use it until you initialize it. So this:

a[i] = var;

will fail.

A possible solution would be initialize it when declaring it:

double a[] = new double[PUT_A_LENGTH_HERE]; //seems like this constant should be 7

IMO more important than solving this exception, is the fact that you should learn to read the stacktrace and understand what it says, so you could detect the problems and solve it.

java.lang.NullPointerException

This exception means there's a variable with null value being used. How to solve? Just make sure the variable is not null before being used.

at twoten.TwoTenB.(TwoTenB.java:29)

This line has two parts:

  • First, shows the class and method where the error was thrown. In this case, it was at <init> method in class TwoTenB declared in package twoten. When you encounter an error message with SomeClassName.<init>, means the error was thrown while creating a new instance of the class e.g. executing the constructor (in this case that seems to be the problem).
  • Secondly, shows the file and line number location where the error is thrown, which is between parenthesis. This way is easier to spot where the error arose. So you have to look into file TwoTenB.java, line number 29. This seems to be a[i] = var;.

From this line, other lines will be similar to tell you where the error arose. So when reading this:

at javapractice.JavaPractice.main(JavaPractice.java:32)

It means that you were trying to instantiate a TwoTenB object reference inside the main method of your class JavaPractice declared in javapractice package.

Why aren't variable-length arrays part of the C++ standard?

This was considered for inclusion in C++/1x, but was dropped (this is a correction to what I said earlier).

It would be less useful in C++ anyway since we already have std::vector to fill this role.

Sending HTML mail using a shell script

First you need to compose the message. The bare minimum is composed of these two headers:

MIME-Version: 1.0
Content-Type: text/html

... and the appropriate message body:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head><title></title>
</head>
<body>

<p>Hello, world!</p>

</body>
</html>

Once you have it, you can pass the appropriate information to the mail command:

body = '...'

echo $body | mail \
-a "From: [email protected]" \
-a "MIME-Version: 1.0" \
-a "Content-Type: text/html" \
-s "This is the subject" \
[email protected]

This is an oversimplified example, since you also need to take care of charsets, encodings, maximum line length... But this is basically the idea.

Alternatively, you can write your script in Perl or PHP rather than plain shell.

Update

A shell script is basically a text file with Unix line endings that starts with a line called shebang that tells the shell what interpreter it must pass the file to, follow some commands in the language the interpreter understands and has execution permission (in Unix that's a file attribute). E.g., let's say you save the following as hello-world:

#!/bin/sh

echo Hello, world!

Then you assign execution permission:

chmod +x hello-world

And you can finally run it:

./hello-world

Whatever, this is kind of unrelated to the original question. You should get familiar with basic shell scripting before doing advanced tasks with it. Here you are a couple of links about bash, a popular shell:

http://www.gnu.org/software/bash/manual/html_node/index.html

http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html

copying all contents of folder to another folder using batch file?

I see a lot of answers suggesting the use of xcopy. But this is unnecessary. As the question clearly mentions that the author wants THE CONTENT IN THE FOLDER not the folder itself to be copied in this case we can -:

copy "C:\Folder1" *.*  "D:\Folder2"

Thats all xcopy can be used for if any subdirectory exists in C:\Folder1

How do I create a message box with "Yes", "No" choices and a DialogResult?

if (MessageBox.Show("Please confirm before proceed" + "\n" + "Do you want to Continue ?", "Confirm", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)

{
//do something if YES
}

else

{
//do something if NO
}

It will Prompt a message box like this.

while installing vc_redist.x64.exe, getting error "Failed to configure per-machine MSU package."

I faced a similar problem but in my case I was trying to install Visual C++ Redistributable for Visual Studio 2015 Update 1 on Windows Server 2012 R2. However the root cause should be the same.

In short, you need to install the prerequisites of KB2999226.

In more details, the installation log I got stated that the installation for Windows Update KB2999226 failed. According to the Microsoft website here:

Prerequisites To install this update, you must have April 2014 update rollup for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 (2919355) installed in Windows 8.1 or Windows Server 2012 R2. Or, install Service Pack 1 for Windows 7 or Windows Server 2008 R2. Or, install Service Pack 2 for Windows Vista and for Windows Server 2008.

After I have installed April 2014 on my Windows Server 2012 R2, I am able to install the Visual C++ Redistributable correctly.

Creating CSS Global Variables : Stylesheet theme management

Latest Update: 16/01/2020

CSS Custom Properties (Variables) have arrived!

It's 2020 and time to officially roll out this feature in your new applications.


Preprocessor "NOT" required!

There is a lot of repetition in CSS. A single color may be used in several places.

For some CSS declarations, it is possible to declare this higher in the cascade and let CSS inheritance solve this problem naturally.

For non-trivial projects, this is not always possible. By declaring a variable on the :root pseudo-element, a CSS author can halt some instances of repetition by using the variable.

How it works

Set your variable at the top of your stylesheet:

CSS

Create a root class:

:root {
}

Create variables (-- [String] : [value])

:root {
  --red: #b00;
  --blue: #00b;
  --fullwidth: 100%;
}

Set your variables anywhere in your CSS document:

h1 {
  color: var(--red);
}
#MyText {
  color: var(--blue);
  width: var(--fullwidth);
}

BROWSER SUPPORT / COMPATIBILITY

See caniuse.com for current compatability.

![supported browsers


Firefox: Version 31+ (Enabled by default)

Supported since 2014 (Leading the way as usual.)

More info from Mozilla


Chrome: Version 49+ (Enabled by default).

Supported since 2016


Safari/IOS Safari: Version 9.1/9.3 (Enabled by default).

Supported since 2016


Opera: Version 39+ (Enabled by default).

Supported since 2016


Android: Version 52+ (Enabled by default).

Supported since 2016


Edge: Version 15+ (Enabled by default).

Supported since 2017

CSS Custom Properties landed in Windows Insider Preview build 14986


IE: When pigs fly.

It's time to finally let this ship sink. No one enjoyed riding her anyway. ?


W3C SPEC

Full specification for upcoming CSS variables

Read more


TRY IT OUT

A fiddle and snippet are attached below for testing:

(It will only work with supported browsers.)

DEMO FIDDLE

_x000D_
_x000D_
:root {
  --red: #b00;
  --blue: #4679bd;
  --grey: #ddd;
  --W200: 200px;
  --Lft: left;
}
.Bx1,
.Bx2,
.Bx3,
.Bx4 {
  float: var(--Lft);
  width: var(--W200);
  height: var(--W200);
  margin: 10px;
  padding: 10px;
  border: 1px solid var(--red);
}
.Bx1 {
  color: var(--red);
  background: var(--grey);
}
.Bx2 {
  color: var(--grey);
  background: black;
}
.Bx3 {
  color: var(--grey);
  background: var(--blue);
}
.Bx4 {
  color: var(--grey);
  background: var(--red);
}
_x000D_
<p>If you see four square boxes then variables are working as expected.</p>

<div class="Bx1">I should be red text on grey background.</div>
<div class="Bx2">I should be grey text on black background.</div>
<div class="Bx3">I should be grey text on blue background.</div>
<div class="Bx4">I should be grey text on red background.</div>
_x000D_
_x000D_
_x000D_

Where is jarsigner?

In my case I try this:

sudo apt install openjdk-11-jdk-headless
sudo apt install openjdk-8-jdk-headless

I use openjdk

Android: Center an image

Another method. (in Relative tested, but I think in Linear would be also works)

    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:adjustViewBounds="true"
    android:gravity="center"

If you use Eclipse you can choose graphical layout when *.xml file is active. On the top, you will find the Structure and option Adjust View Bounds. It will cut short all dimensions of pseudo-frame (blue rectangle) to size of your drawable file.

See also the scaleType option with make funny your image. Try it in Eclipse ;)

When do I need to do "git pull", before or after "git add, git commit"?

pull = fetch + merge.

You need to commit what you have done before merging.

So pull after commit.

How do I POST with multipart form data using fetch?

You're setting the Content-Type to be multipart/form-data, but then using JSON.stringify on the body data, which returns application/json. You have a content type mismatch.

You will need to encode your data as multipart/form-data instead of json. Usually multipart/form-data is used when uploading files, and is a bit more complicated than application/x-www-form-urlencoded (which is the default for HTML forms).

The specification for multipart/form-data can be found in RFC 1867.

For a guide on how to submit that kind of data via javascript, see here.

The basic idea is to use the FormData object (not supported in IE < 10):

async function sendData(url, data) {
  const formData  = new FormData();

  for(const name in data) {
    formData.append(name, data[name]);
  }

  const response = await fetch(url, {
    method: 'POST',
    body: formData
  });

  // ...
}

Per this article make sure not to set the Content-Type header. The browser will set it for you, including the boundary parameter.

How to Convert Int to Unsigned Byte and Back

If you want to use the primitive wrapper classes, this will work, but all java types are signed by default.

public static void main(String[] args) {
    Integer i=5;
    Byte b = Byte.valueOf(i+""); //converts i to String and calls Byte.valueOf()
    System.out.println(b);
    System.out.println(Integer.valueOf(b));
}

How to zero pad a sequence of integers in bash so that all have the same width?

1.) Create a sequence of numbers 'seq' from 1 to 1000, and fix the width '-w' (width is determined by length of ending number, in this case 4 digits for 1000).

2.) Also, select which numbers you want using 'sed -n' (in this case, we select numbers 1-100).

3.) 'echo' out each number. Numbers are stored in the variable 'i', accessed using the '$'.

Pros: This code is pretty clean.

Cons: 'seq' isn't native to all Linux systems (as I understand)

for i in `seq -w 1 1000 | sed -n '1,100p'`; 
do 
    echo $i; 
done

Error: 'int' object is not subscriptable - Python

x is already integer(x=0) and again you trying to make x again integer and also you gave indexing which is beyound the limit because x already has only one indexing (0) and you are trying to give indexing same as age so thats why you get this error. use this simple code

name1 = input("What's your name? ")
age1 = int(input ("how old are you?" ))
x=0
twentyone = str(21-age1)
print("Hi, " +name1+ " you will be 21 in: " + twentyone + " years.")

AngularJS - How to use $routeParams in generating the templateUrl?

Router:-

...
.when('/enquiry/:page', {
    template: '<div ng-include src="templateUrl" onload="onLoad()"></div>',
    controller: 'enquiryCtrl'
})
...

Controller:-

...
// template onload event
$scope.onLoad = function() {
    console.log('onLoad()');
    f_tcalInit();  // or other onload stuff
}

// initialize
$scope.templateUrl = 'ci_index.php/adminctrl/enquiry/'+$routeParams.page;
...

I believe it is a weakness in angularjs that $routeParams is NOT visible inside the router. A tiny enhancement would make a world of difference during implementation.

Webdriver Screenshot

driver.save_screenshot("path to save \\screen.jpeg")

Search text in fields in every table of a MySQL database

I modified the PHP answer of Olivier a bit to:

  • print out the results in which the string was found
  • omit tables without results
  • also show output if column names match the search input
  • show total number of results

    function searchAllDB($search){
        global $mysqli;
    
        $out = "";
        $total = 0;
        $sql = "SHOW TABLES";
        $rs = $mysqli->query($sql);
        if($rs->num_rows > 0){
            while($r = $rs->fetch_array()){
                $table = $r[0];
                $sql_search = "select * from ".$table." where ";
                $sql_search_fields = Array();
                $sql2 = "SHOW COLUMNS FROM ".$table;
                $rs2 = $mysqli->query($sql2);
                if($rs2->num_rows > 0){
                    while($r2 = $rs2->fetch_array()){
                        $colum = $r2[0];
                        $sql_search_fields[] = $colum." like('%".$search."%')";
                        if(strpos($colum,$search))
                        {
                            echo "FIELD NAME: ".$colum."\n";
                        }
                    }
                    $rs2->close();
                }
                $sql_search .= implode(" OR ", $sql_search_fields);
                $rs3 = $mysqli->query($sql_search);
                if($rs3 && $rs3->num_rows > 0)
                {
                    $out .= $table.": ".$rs3->num_rows."\n";
                    if($rs3->num_rows > 0){
                        $total += $rs3->num_rows;
                        $out.= print_r($rs3->fetch_all(),1);
                        $rs3->close();
                    }
                }
            }
            $out .= "\n\nTotal results:".$total;
            $rs->close();
        }
        return $out;
    }
    

java.lang.ClassNotFoundException: org.springframework.core.io.Resource

There is a version conflict between jar/dependency please check all version of spring is same. if you use maven remove version of dependency and use Spring.io dependency.it handle version conflict. Add this in your pom

 <dependency>
            <groupId>io.spring.platform</groupId>
            <artifactId>platform-bom</artifactId>
            <version>2.0.1.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
  </dependency>

How to change Maven local repository in eclipse

In newer versions of Eclipse the global configuration file can be set in

Windows > Preferences > Maven > User Settings > Global Settings

Don't beat me why global settings can be configured in user settings... Probably because of the same reason why you need to press "Start" to shutdown your PC on Windows... :D

How to create web service (server & Client) in Visual Studio 2012?

--- create a ws server vs2012 upd 3

  1. new project

  2. choose .net framework 3.5

  3. asp.net web service application

  4. right click on the project root

  5. choose add service reference

  6. choose wsdl

--- how can I create a ws client from a wsdl file?

I´ve a ws server Axis2 under tomcat 7 and I want to test the compatibility

Why are primes important in cryptography?

Because nobody knows a fast algorithm to factorize an integer into its prime factors. Yet, it is very easy to check if a set of prime factors multiply to a certain integer.

How to redirect all HTTP requests to HTTPS

Update: Although this answer has been accepted a few years ago, note that its approach is now recommended against by the Apache documentation. Use a Redirect instead. See this answer.


RewriteEngine On
RewriteCond %{HTTPS} !on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

WinForms DataGridView font size

The straight forward approach:

this.dataGridView1.DefaultCellStyle.Font = new Font("Tahoma", 15);

Detecting value change of input[type=text] in jQuery

Try this:

$("input").bind({
            paste : function(){
                $('#eventresult').text('paste behaviour detected!');
            }
})

How to make a shape with left-top round rounded corner and left-bottom rounded corner?

This bug is filed here. This is a bug of android devices having API level less than 12. You've to put correct versions of your layouts in drawable-v12 folder which will be used for API level 12 or higher. And an erroneous version(corners switched/reversed) of the same layout will be put in the default drawable folder which will be used by the devices having API level less than 12.

For example: I had to design a button with rounded corner at bottom-right.

In 'drawable' folder - button.xml: I had to make bottom-left corner rounded.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

In 'drawable-v12' folder - button.xml: Correct version of the layout was placed here to be used for API level 12 or higher.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

How can I read an input string of unknown length?

Enter while securing an area dynamically

E.G.

#include <stdio.h>
#include <stdlib.h>

char *inputString(FILE* fp, size_t size){
//The size is extended by the input with the value of the provisional
    char *str;
    int ch;
    size_t len = 0;
    str = realloc(NULL, sizeof(*str)*size);//size is start size
    if(!str)return str;
    while(EOF!=(ch=fgetc(fp)) && ch != '\n'){
        str[len++]=ch;
        if(len==size){
            str = realloc(str, sizeof(*str)*(size+=16));
            if(!str)return str;
        }
    }
    str[len++]='\0';

    return realloc(str, sizeof(*str)*len);
}

int main(void){
    char *m;

    printf("input string : ");
    m = inputString(stdin, 10);
    printf("%s\n", m);

    free(m);
    return 0;
}

AngularJS Directive Restrict A vs E

Pitfall:

  1. Using your own html element like <my-directive></my-directive> wont work on IE8 without workaround (https://docs.angularjs.org/guide/ie)
  2. Using your own html elements will make html validation fail.
  3. Directives with equal one parameter can done like this:

<div data-my-directive="ValueOfTheFirstParameter"></div>

Instead of this:

<my-directive my-param="ValueOfTheFirstParameter"></my-directive>

We dont use custom html elements, because if this 2 facts.

Every directive by third party framework can be written in two ways:

<my-directive></my-directive>

or

<div data-my-directive></div>

does the same.

Concatenating Files And Insert New Line In Between Files

That's how I just did it on OsX 10.10.3

for f in *.txt; do (cat $f; echo '') >> fullData.txt; done

since the simple 'echo' command with no params ended up in no new lines inserted.

HTTP test server accepting GET/POST requests

There is http://ptsv2.com/

"Here you will find a server which receives any POST you wish to give it and stores the contents for you to review."

"code ." Not working in Command Line for Visual Studio Code on OSX/Mac

For those of you that run ZShell with Iterm2, add this to your ~/.zshrc file.

alias code="/Applications/Visual\ Studio\ Code.app/Contents/Resources/app/bin/code"

Java JTable getting the data of the selected row

You can use the following code to get the value of the first column of the selected row of your table.

int column = 0;
int row = table.getSelectedRow();
String value = table.getModel().getValueAt(row, column).toString();

How can a file be copied?

Use the shutil module.

copyfile(src, dst)

Copy the contents of the file named src to a file named dst. The destination location must be writable; otherwise, an IOError exception will be raised. If dst already exists, it will be replaced. Special files such as character or block devices and pipes cannot be copied with this function. src and dst are path names given as strings.

Take a look at filesys for all the file and directory handling functions available in standard Python modules.

bootstrap 4 responsive utilities visible / hidden xs sm lg not working

Some version working

<div class="hidden-xs">Only Mobile hidden</div>
<div class="visible-xs">Only Mobile visible</div>

Cannot find control with name: formControlName in angular reactive form

For me even with [formGroup] the error was popping up "Cannot find control with name:''".
It got fixed when I added ngModel Value to the input box along with formControlName="fileName"

  <form class="upload-form" [formGroup]="UploadForm">
  <div class="row">
    <div class="form-group col-sm-6">
      <label for="fileName">File Name</label>
      <!-- *** *** *** Adding [(ngModel)]="FileName" fixed the issue-->
      <input type="text" class="form-control" id="fileName" [(ngModel)]="FileName"
        placeholder="Enter file name" formControlName="fileName"> 
    </div>
    <div class="form-group col-sm-6">
      <label for="selectedType">File Type</label>
      <select class="form-control" formControlName="selectedType" id="selectedType" 
        (change)="TypeChanged(selectedType)" name="selectedType" disabled="true">
        <option>Type 1</option>
        <option>Type 2</option>
      </select>
    </div>
  </div>
  <div class="form-group">
    <label for="fileUploader">Select {{selectedType}} file</label>
    <input type="file" class="form-control-file" id="fileUploader" (change)="onFileSelected($event)">
  </div>
  <div class="w-80 text-right mt-3">
    <button class="btn btn-primary mb-2 search-button cancel-button" (click)="cancelUpload()">Cancel</button>
    <button class="btn btn-primary mb-2 search-button" (click)="uploadFrmwrFile()">Upload</button>
  </div>
 </form>

And in the controller

ngOnInit() {
this.UploadForm= new FormGroup({
  fileName: new FormControl({value: this.FileName}),
  selectedType: new FormControl({value: this.selectedType, disabled: true}, Validators.required),
  frmwareFile: new FormControl({value: ['']})
});
}

how to find 2d array size in c++

int arr[5][4];

For the row subscript(4 raise to 2, include cmath to use pow):

sizeof(arr1)/pow(4,2)   

Column subscript:

sizeof(*arr1)/4

4 means 4 bytes, size of int.

Return multiple values from a function in swift

Also:

func getTime() -> (hour: Int, minute: Int,second: Int) {
    let hour = 1
    let minute = 2
    let second = 3
    return ( hour, minute, second)
}

Then it's invoked as:

let time = getTime()
print("hour: \(time.hour), minute: \(time.minute), second: \(time.second)")

This is the standard way how to use it in the book The Swift Programming Language written by Apple.

or just like:

let time = getTime()
print("hour: \(time.0), minute: \(time.1), second: \(time.2)")

it's the same but less clearly.

How can I check if two segments intersect?

The answer by Georgy is the cleanest to implement, by far. Had to chase this down, since the brycboe example, while simple as well, had issues with colinearity.

Code for testing:

#!/usr/bin/python
#
# Notes on intersection:
#
# https://bryceboe.com/2006/10/23/line-segment-intersection-algorithm/
#
# https://stackoverflow.com/questions/3838329/how-can-i-check-if-two-segments-intersect

from shapely.geometry import LineString

class Point:
    def __init__(self,x,y):
        self.x = x
        self.y = y

def ccw(A,B,C):
    return (C.y-A.y)*(B.x-A.x) > (B.y-A.y)*(C.x-A.x)

def intersect(A,B,C,D):
    return ccw(A,C,D) != ccw(B,C,D) and ccw(A,B,C) != ccw(A,B,D)


def ShapelyIntersect(A,B,C,D):
    return LineString([(A.x,A.y),(B.x,B.y)]).intersects(LineString([(C.x,C.y),(D.x,D.y)]))


a = Point(0,0)
b = Point(0,1)
c = Point(1,1)
d = Point(1,0)

'''
Test points:

b(0,1)   c(1,1)




a(0,0)   d(1,0)
'''

# F
print(intersect(a,b,c,d))

# T
print(intersect(a,c,b,d))
print(intersect(b,d,a,c))
print(intersect(d,b,a,c))

# F
print(intersect(a,d,b,c))

# same end point cases:
print("same end points")
# F - not intersected
print(intersect(a,b,a,d))
# T - This shows as intersected
print(intersect(b,a,a,d))
# F - this does not
print(intersect(b,a,d,a))
# F - this does not
print(intersect(a,b,d,a))

print("same end points, using shapely")
# T
print(ShapelyIntersect(a,b,a,d))
# T
print(ShapelyIntersect(b,a,a,d))
# T
print(ShapelyIntersect(b,a,d,a))
# T
print(ShapelyIntersect(a,b,d,a))

Twitter Bootstrap hide css class and jQuery

If an element has bootstrap's "hide" class and you want to display it with some sliding effect such as .slideDown(), you can cheat bootstrap like:

$('#hiddenElement').hide().removeClass('hide').slideDown('fast')

Multiple radio button groups in one form

in input field make name same like

<input type="radio" name="option" value="option1">
<input type="radio" name="option" value="option2" >
<input type="radio" name="option" value="option3" >
<input type="radio" name="option" value="option3" >

Append an empty row in dataframe using pandas

Assuming your df.index is sorted you can use:

df.loc[df.index.max() + 1] = None

It handles well different indexes and column types.

[EDIT] it works with pd.DatetimeIndex if there is a constant frequency, otherwise we must specify the new index exactly e.g:

df.loc[df.index.max() + pd.Timedelta(milliseconds=1)] = None

long example:

df = pd.DataFrame([[pd.Timestamp(12432423), 23, 'text_field']], 
                    columns=["timestamp", "speed", "text"],
                    index=pd.DatetimeIndex(start='2111-11-11',freq='ms', periods=1))
df.info()

<class 'pandas.core.frame.DataFrame'> DatetimeIndex: 1 entries, 2111-11-11 to 2111-11-11 Freq: L Data columns (total 3 columns): timestamp 1 non-null datetime64[ns] speed 1 non-null int64 text 1 non-null object dtypes: datetime64[ns](1), int64(1), object(1) memory usage: 32.0+ bytes

df.loc[df.index.max() + 1] = None
df.info()

<class 'pandas.core.frame.DataFrame'> DatetimeIndex: 2 entries, 2111-11-11 00:00:00 to 2111-11-11 00:00:00.001000 Data columns (total 3 columns): timestamp 1 non-null datetime64[ns] speed 1 non-null float64 text 1 non-null object dtypes: datetime64[ns](1), float64(1), object(1) memory usage: 64.0+ bytes

df.head()

                            timestamp                   speed      text
2111-11-11 00:00:00.000 1970-01-01 00:00:00.012432423   23.0    text_field
2111-11-11 00:00:00.001 NaT NaN NaN

Renaming files using node.js

For synchronous renaming use fs.renameSync

fs.renameSync('/path/to/Afghanistan.png', '/path/to/AF.png');

How to find lines containing a string in linux

The usual way to do this is with grep, which uses a pattern to match lines:

grep 'pattern' file

Each line which matches the pattern will be output. If you want to search for fixed strings only, use grep -F 'pattern' file.

Calling a JavaScript function returned from an Ajax response

That seems a rather weird design for your code - it generally makes more sense to have your functions called directly from a .js file, and then only retrieve data with the Ajax call.

However, I believe it should work by calling eval() on the response - provided it is syntactically correct JavaScript code.

JavaScript for handling Tab Key press

Only one suggestion instead of 9 you can use KeyCodes.TAB.

width:auto for <input> fields

Answer 1 - "response" gave a nice answer/link for it. To put it in short, "auto" is the default, so it is like removing any changes in the width of an element

Answer 2 - use width: 100% instead. It will fill the 100% of the parent container, in this case, the "form".

Laravel Blade html image

In Laravel 5.x you can use laravelcollective/html and the syntax:

{!! Html::image('img/logo.png') !!}

How many threads is too many?

As many threads as the CPU cores is what I've heard very often.

Split a large dataframe into a list of data frames based on common value in column

From version 0.8.0, dplyr offers a handy function called group_split():

# On sample data from @Aus_10

df %>%
  group_split(g)

[[1]]
# A tibble: 25 x 3
   ran_data1 ran_data2 g    
       <dbl>     <dbl> <fct>
 1     2.04      0.627 A    
 2     0.530    -0.703 A    
 3    -0.475     0.541 A    
 4     1.20     -0.565 A    
 5    -0.380    -0.126 A    
 6     1.25     -1.69  A    
 7    -0.153    -1.02  A    
 8     1.52     -0.520 A    
 9     0.905    -0.976 A    
10     0.517    -0.535 A    
# … with 15 more rows

[[2]]
# A tibble: 25 x 3
   ran_data1 ran_data2 g    
       <dbl>     <dbl> <fct>
 1     1.61      0.858 B    
 2     1.05     -1.25  B    
 3    -0.440    -0.506 B    
 4    -1.17      1.81  B    
 5     1.47     -1.60  B    
 6    -0.682    -0.726 B    
 7    -2.21      0.282 B    
 8    -0.499     0.591 B    
 9     0.711    -1.21  B    
10     0.705     0.960 B    
# … with 15 more rows

To not include the grouping column:

df %>%
 group_split(g, keep = FALSE)

How to convert a hex string to hex number

Use format string

intNum = 123
print "0x%x"%(intNum)

or hex function.

intNum = 123
print hex(intNum)

How to grep for contents after pattern?

Or use regex assertions: grep -oP '(?<=potato: ).*' file.txt

Getting Date or Time only from a DateTime Object

You can also use DateTime.Now.ToString("yyyy-MM-dd") for the date, and DateTime.Now.ToString("hh:mm:ss") for the time.

Replace part of a string in Python?

Use the replace() method on string:

>>> stuff = "Big and small"
>>> stuff.replace( " and ", "/" )
'Big/small'

How to return a boolean method in java?

try this:

public boolean verifyPwd(){
        if (!(pword.equals(pwdRetypePwd.getText()))){
                  txtaError.setEditable(true);
                  txtaError.setText("*Password didn't match!");
                  txtaError.setForeground(Color.red);
                  txtaError.setEditable(false);
                  return false;
           }
        else {
            return true;
        }

}

if (verifyPwd()==true){
    addNewUser();
}
else {
    // passwords do not match
}

How do I use MySQL through XAMPP?

XAMPP only offers MySQL (Database Server) & Apache (Webserver) in one setup and you can manage them with the xampp starter.

After the successful installation navigate to your xampp folder and execute the xampp-control.exe

Press the start Button at the mysql row.

enter image description here

Now you've successfully started mysql. Now there are 2 different ways to administrate your mysql server and its databases.

But at first you have to set/change the MySQL Root password. Start the Apache server and type localhost or 127.0.0.1 in your browser's address bar. If you haven't deleted anything from the htdocs folder the xampp status page appears. Navigate to security settings and change your mysql root password.

Now, you can browse to your phpmyadmin under http://localhost/phpmyadmin or download a windows mysql client for example navicat lite or mysql workbench. Install it and log in to your mysql server with your new root password.

enter image description here

TabLayout tab selection

If you are using TabLayout with viewPager then this helps you. You set the TabLayout with ViewPager in addOnpagelistener.

if you want to set the TabLayout position directly(not click on the Tab individual) try below code tabLayout.getTabAt(position_you_want_to_set).select()

   /* will be invoked whenever the page changes or is incrementally scrolled*/
    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {
            tabLayout.getTabAt(position).select();
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

JOptionPane Yes or No window

You are always checking for a true condition, hence your message will always show.

You should replace your if (true) statement with if ( n == JOptionPane.YES_OPTION)

When one of the showXxxDialog methods returns an integer, the possible values are:

YES_OPTION NO_OPTION CANCEL_OPTION OK_OPTION CLOSED_OPTION

From here

How can I emulate a get request exactly like a web browser?

Are you sure the curl module honors ini_set('user_agent',...)? There is an option CURLOPT_USERAGENT described at http://docs.php.net/function.curl-setopt.
Could there also be a cookie tested by the server? That you can handle by using CURLOPT_COOKIE, CURLOPT_COOKIEFILE and/or CURLOPT_COOKIEJAR.

edit: Since the request uses https there might also be error in verifying the certificate, see CURLOPT_SSL_VERIFYPEER.

$url="https://new.aol.com/productsweb/subflows/ScreenNameFlow/AjaxSNAction.do?s=username&f=firstname&l=lastname";
$agent= 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.0.3705; .NET CLR 1.1.4322)';

$ch = curl_init();
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_USERAGENT, $agent);
curl_setopt($ch, CURLOPT_URL,$url);
$result=curl_exec($ch);
var_dump($result);

Simple JavaScript login form validation

Here is some useful links with example Login form Validation in javascript

function validate() {
        var username = document.getElementById("username").value;
        var password = document.getElementById("password").value;
        if (username == null || username == "") {
            alert("Please enter the username.");
            return false;
        }
        if (password == null || password == "") {
            alert("Please enter the password.");
            return false;
        }
        alert('Login successful');

    } 

  <input type="text" name="username" id="username" />
  <input type="password" name="password" id="password" />
  <input type="button" value="Login" id="submit" onclick="validate();" />

Elasticsearch : Root mapping definition has unsupported parameters index : not_analyzed

PUT /testIndex
{
    "mappings": {
        "properties": {     <--ADD THIS
            "field1": {
                "type": "integer"
            },
            "field2": {  
                "type": "integer"
            },
            "field3": {
                "type": "string",
                "index": "not_analyzed"
            },
            "field4": {
                "type": "string",
                "analyzer": "autocomplete",
                "search_analyzer": "standard"
            }
        }
    },
    "settings": {
        bla
        bla
        bla
    }
}

Here's a similar command I know works:

curl -v -H "Content-Type: application/json" -H "Authorization: Basic cGC3COJ1c2Vy925hZGFJbXBvcnABCnRl" -X PUT -d '{"mappings":{"properties":{"city":{"type": "text"}}}}' https://35.80.2.21/manzanaIndex

The breakdown for the above curl command is:

PUT /manzanaIndex
{
    "mappings":{
        "properties":{
                "city":{
                    "type": "text"
                }
        }
    }
}

How does Access-Control-Allow-Origin header work?

If you are using PHP, try adding the following code at the beginning of the php file:

If you are using localhost, try this:

header("Access-Control-Allow-Origin: *");

If you are using external domains such as server, try this:

header("Access-Control-Allow-Origin: http://www.website.com");

Detect if the device is iPhone X

Usually, the Programmer needs it for constraining to top or bottom, so these methods can help

static func extraTop() -> CGFloat {

    var top: CGFloat = 0

    if #available(iOS 11.0, *) {

        if let t = UIApplication.shared.keyWindow?.safeAreaInsets.top {
            top = t
        }
    }
    return top
}

static func extraBottom() -> CGFloat {

    var bottom: CGFloat = 0

    if #available(iOS 11.0, *) {

        if let b = UIApplication.shared.keyWindow?.safeAreaInsets.bottom {
            bottom = b
        }
    }
    return bottom
}

For before iPhone X these methods return: 0

For iPhone X: 44 and 34 accordingly

Then just add these extras to top or bottom constraints

Detect key input in Python

You could make a little Tkinter app:

import Tkinter as tk

def onKeyPress(event):
    text.insert('end', 'You pressed %s\n' % (event.char, ))

root = tk.Tk()
root.geometry('300x200')
text = tk.Text(root, background='black', foreground='white', font=('Comic Sans MS', 12))
text.pack()
root.bind('<KeyPress>', onKeyPress)
root.mainloop()

how to get right offset of an element? - jQuery

There's a native DOM API that achieves this out of the box — getBoundingClientRect:

document.querySelector("#whatever").getBoundingClientRect().right

IF EXISTS condition not working with PLSQL

IF EXISTS() is semantically incorrect. EXISTS condition can be used only inside a SQL statement. So you might rewrite your pl/sql block as follows:

declare
  l_exst number(1);
begin
  select case 
           when exists(select ce.s_regno 
                         from courseoffering co
                         join co_enrolment ce
                           on ce.co_id = co.co_id
                        where ce.s_regno=403 
                          and ce.coe_completionstatus = 'C' 
                          and ce.c_id = 803
                          and rownum = 1
                        )
           then 1
           else 0
         end  into l_exst
  from dual;

  if l_exst = 1 
  then
    DBMS_OUTPUT.put_line('YES YOU CAN');
  else
    DBMS_OUTPUT.put_line('YOU CANNOT'); 
  end if;
end;

Or you can simply use count function do determine the number of rows returned by the query, and rownum=1 predicate - you only need to know if a record exists:

declare
  l_exst number;
begin
   select count(*) 
     into l_exst
     from courseoffering co
          join co_enrolment ce
            on ce.co_id = co.co_id
    where ce.s_regno=403 
      and ce.coe_completionstatus = 'C' 
      and ce.c_id = 803
      and rownum = 1;

  if l_exst = 0
  then
    DBMS_OUTPUT.put_line('YOU CANNOT');
  else
    DBMS_OUTPUT.put_line('YES YOU CAN');
  end if;
end;

Oracle SqlPlus - saving output in a file but don't show on screen

Try this:

SET TERMOUT OFF; 
spool M:\Documents\test;
select * from employees;
/
spool off;

How to align linearlayout to vertical center?

Change orientation and gravity in

<LinearLayout
    android:id="@+id/groupNumbers"
    android:orientation="horizontal"
    android:gravity="center_vertical"
    android:layout_weight="0.7"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

to

android:orientation="vertical"
android:layout_gravity="center_vertical"

You are adding orientation: horizontal, so the layout will contain all elements in single horizontal line. Which won't allow you to get the element in center.

Hope this helps.

ORA-01950: no privileges on tablespace 'USERS'

You cannot insert data because you have a quota of 0 on the tablespace. To fix this, run

ALTER USER <user> quota unlimited on <tablespace name>;

or

ALTER USER <user> quota 100M on <tablespace name>;

as a DBA user (depending on how much space you need / want to grant).

Remove attribute "checked" of checkbox

using .removeAttr() on a boolean attribute such as checked, selected, or readonly would also set the corresponding named property to false.

Hence removed this checked attribute

$("#IdName option:checked").removeAttr("checked");

Disable Tensorflow debugging information

None of the solutions above could solve my problem in Jupyter Notebook, so I use the following snippet code bellow from Cicoria, and issues solved.

import warnings  
with warnings.catch_warnings():  
    warnings.filterwarnings("ignore",category=FutureWarning)
    import tensorflow as tf
    from tensorflow import keras
    from tensorflow.keras.preprocessing.text import Tokenizer

print('Done') 

CSS horizontal scroll

check this link here i change display:inline-block http://cssdesk.com/gUGBH

Count textarea characters

    $(document).ready(function(){ 
    $('#characterLeft').text('140 characters left');
    $('#message').keydown(function () {
        var max = 140;
        var len = $(this).val().length;
        if (len >= max) {
            $('#characterLeft').text('You have reached the limit');
            $('#characterLeft').addClass('red');
            $('#btnSubmit').addClass('disabled');            
        } 
        else {
            var ch = max - len;
            $('#characterLeft').text(ch + ' characters left');
            $('#btnSubmit').removeClass('disabled');
            $('#characterLeft').removeClass('red');            
        }
    });    
});

Convert List<Object> to String[] in Java

You could use toArray() to convert into an array of Objects followed by this method to convert the array of Objects into an array of Strings:

Object[] objectArray = lst.toArray();
String[] stringArray = Arrays.copyOf(objectArray, objectArray.length, String[].class);

How can you create multiple cursors in Visual Studio Code

There is no binding for exactly what you want.

The only thing that comes close is Ctrl+F2 which will select all of them at once.

You can bind it to Ctrl+D doing the following:

  • Click on File > Preferences > Keyboard Shortcuts
    You should see a pane full of the current bindings and on the right a list of custom bindings
  • In the current bindings, search for Ctrl+F2 and copy that whole line and paste it into the right pane.
  • You might have to remove the comma at the end and then change Ctrl+F2 to Ctrl+D and then save the file.

It should look something like this:

// Place your key bindings in this file to overwrite the defaults
[
{ "key": "ctrl+d",               "command": "editor.action.changeAll",
                                    "when": "editorTextFocus" }
]

"Expected an indented block" error?

I also experienced that for example:

This code doesnt work and get the intended block error.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
return self.title

However, when i press tab before typing return self.title statement, the code works.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
    return self.title

Hope, this will help others.

Standardize data columns in R

Realizing that the question is old and one answer is accepted, I'll provide another answer for reference.

scale is limited by the fact that it scales all variables. The solution below allows to scale only specific variable names while preserving other variables unchanged (and the variable names could be dynamically generated):

library(dplyr)

set.seed(1234)
dat <- data.frame(x = rnorm(10, 30, .2), 
                  y = runif(10, 3, 5),
                  z = runif(10, 10, 20))
dat

dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2

which gives me this:

> dat
          x        y        z
1  29.75859 3.633225 14.56091
2  30.05549 3.605387 12.65187
3  30.21689 3.318092 13.04672
4  29.53086 3.079992 15.07307
5  30.08582 3.437599 11.81096
6  30.10121 4.621197 17.59671
7  29.88505 4.051395 12.01248
8  29.89067 4.829316 12.58810
9  29.88711 4.662690 19.92150
10 29.82199 3.091541 18.07352

and

> dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
> dat2
          x          y           z
1  29.75859 -0.3004815 -0.06016029
2  30.05549 -0.3423437 -0.72529604
3  30.21689 -0.7743696 -0.58772361
4  29.53086 -1.1324181  0.11828039
5  30.08582 -0.5946582 -1.01827752
6  30.10121  1.1852038  0.99754666
7  29.88505  0.3283513 -0.94806607
8  29.89067  1.4981677 -0.74751378
9  29.88711  1.2475998  1.80753470
10 29.82199 -1.1150515  1.16367556

EDIT 1 (2016): Addressed Julian's comment: the output of scale is Nx1 matrix so ideally we should add an as.vector to convert the matrix type back into a vector type. Thanks Julian!

EDIT 2 (2019): Quoting Duccio A.'s comment: For the latest dplyr (version 0.8) you need to change dplyr::funcs with list, like dat %>% mutate_each_(list(~scale(.) %>% as.vector), vars=c("y","z"))

EDIT 3 (2020): Thanks to @mj_whales: the old solution is deprecated and now we need to use mutate_at.

Extract Data from PDF and Add to Worksheet

Using Bytescout PDF Extractor SDK is a good option. It is cheap and gives plenty of PDF related functionality. One of the answers above points to the dead page Bytescout on GitHub. I am providing a relevant working sample to extract table from PDF. You may use it to export in any format.

Set extractor = CreateObject("Bytescout.PDFExtractor.StructuredExtractor")

extractor.RegistrationName = "demo"
extractor.RegistrationKey = "demo"

' Load sample PDF document
extractor.LoadDocumentFromFile "../../sample3.pdf"

For ipage = 0 To extractor.GetPageCount() - 1 

    ' starting extraction from page #"
    extractor.PrepareStructure ipage

    rowCount = extractor.GetRowCount(ipage)

    For row = 0 To rowCount - 1 
        columnCount = extractor.GetColumnCount(ipage, row)

        For col = 0 To columnCount-1
            WScript.Echo "Cell at page #" +CStr(ipage) + ", row=" & CStr(row) & ", column=" & _
                CStr(col) & vbCRLF & extractor.GetCellValue(ipage, row, col)
        Next
    Next
Next

Many more samples available here: https://github.com/bytescout/pdf-extractor-sdk-samples

Calling Member Functions within Main C++

From your question it is unclear if you want to be able use the class without an identity or if calling the method requires you to create an instance of the class. This depends on whether you want the printInformation member to write some general information or more specific about the object identity.

Case 1: You want to use the class without creating an instance. The members of that class should be static, using this keyword you tell the compiler that you want to be able to call the method without having to create a new instance of the class.

class MyClass
{
public:
    static void printInformation();
};

Case 2: You want the class to have an instance, you first need to create an object so that the class has an identity, once that is done you can use the object his methods.

Myclass m;
m.printInformation();

// Or, in the case that you want to use pointers:
Myclass * m = new Myclass();
m->printInformation();

If you don't know when to use pointers, read Pukku's summary in this Stack Overflow question.
Please note that in the current case you would not need a pointer. :-)

Does Java read integers in little endian or big endian?

There are no unsigned integers in Java. All integers are signed and in big endian.

On the C side the each byte has tne LSB at the start is on the left and the MSB at the end.

It sounds like you are using LSB as Least significant bit, are you? LSB usually stands for least significant byte. Endianness is not bit based but byte based.

To convert from unsigned byte to a Java integer:

int i = (int) b & 0xFF;

To convert from unsigned 32-bit little-endian in byte[] to Java long (from the top of my head, not tested):

long l = (long)b[0] & 0xFF;
l += ((long)b[1] & 0xFF) << 8;
l += ((long)b[2] & 0xFF) << 16;
l += ((long)b[3] & 0xFF) << 24;

What is causing ERROR: there is no unique constraint matching given keys for referenced table?

In postgresql all foreign keys must reference a unique key in the parent table, so in your bar table you must have a unique (name) index.

See also http://www.postgresql.org/docs/9.1/static/ddl-constraints.html#DDL-CONSTRAINTS-FK and specifically:

Finally, we should mention that a foreign key must reference columns that either are a primary key or form a unique constraint.

Emphasis mine.

CodeIgniter - File upload required validation

  1. set a rule to check the file name (if the form is multipart)

    $this->form_validation->set_rules('upload_file[name]', 'Upload file', 'required', 'No upload image :(');

  2. overwrite the $_POST array as follows:

    $_POST['upload_file'] = $_FILES['upload_file']

  3. and then do:

    $this->form_validation->run()

Module is not available, misspelled or forgot to load (but I didn't)

I had the same error but i resolved it, it was a syntax error in the AngularJS provider

How do I remove a single file from the staging area (undo git add)?

You need to be in the directory of the file and then type the following into the terminal

git checkout -- <file>

How to include another XHTML in XHTML using JSF 2.0 Facelets?

<ui:include>

Most basic way is <ui:include>. The included content must be placed inside <ui:composition>.

Kickoff example of the master page /page.xhtml:

<!DOCTYPE html>
<html lang="en"
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets">
    <h:head>
        <title>Include demo</title>
    </h:head>
    <h:body>
        <h1>Master page</h1>
        <p>Master page blah blah lorem ipsum</p>
        <ui:include src="/WEB-INF/include.xhtml" />
    </h:body>
</html>

The include page /WEB-INF/include.xhtml (yes, this is the file in its entirety, any tags outside <ui:composition> are unnecessary as they are ignored by Facelets anyway):

<ui:composition 
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets">
    <h2>Include page</h2>
    <p>Include page blah blah lorem ipsum</p>
</ui:composition>
  

This needs to be opened by /page.xhtml. Do note that you don't need to repeat <html>, <h:head> and <h:body> inside the include file as that would otherwise result in invalid HTML.

You can use a dynamic EL expression in <ui:include src>. See also How to ajax-refresh dynamic include content by navigation menu? (JSF SPA).


<ui:define>/<ui:insert>

A more advanced way of including is templating. This includes basically the other way round. The master template page should use <ui:insert> to declare places to insert defined template content. The template client page which is using the master template page should use <ui:define> to define the template content which is to be inserted.

Master template page /WEB-INF/template.xhtml (as a design hint: the header, menu and footer can in turn even be <ui:include> files):

<!DOCTYPE html>
<html lang="en"
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets">
    <h:head>
        <title><ui:insert name="title">Default title</ui:insert></title>
    </h:head>
    <h:body>
        <div id="header">Header</div>
        <div id="menu">Menu</div>
        <div id="content"><ui:insert name="content">Default content</ui:insert></div>
        <div id="footer">Footer</div>
    </h:body>
</html>

Template client page /page.xhtml (note the template attribute; also here, this is the file in its entirety):

<ui:composition template="/WEB-INF/template.xhtml"
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets">

    <ui:define name="title">
        New page title here
    </ui:define>

    <ui:define name="content">
        <h1>New content here</h1>
        <p>Blah blah</p>
    </ui:define>
</ui:composition>

This needs to be opened by /page.xhtml. If there is no <ui:define>, then the default content inside <ui:insert> will be displayed instead, if any.


<ui:param>

You can pass parameters to <ui:include> or <ui:composition template> by <ui:param>.

<ui:include ...>
    <ui:param name="foo" value="#{bean.foo}" />
</ui:include>
<ui:composition template="...">
    <ui:param name="foo" value="#{bean.foo}" />
    ...
</ui:composition >

Inside the include/template file, it'll be available as #{foo}. In case you need to pass "many" parameters to <ui:include>, then you'd better consider registering the include file as a tagfile, so that you can ultimately use it like so <my:tagname foo="#{bean.foo}">. See also When to use <ui:include>, tag files, composite components and/or custom components?

You can even pass whole beans, methods and parameters via <ui:param>. See also JSF 2: how to pass an action including an argument to be invoked to a Facelets sub view (using ui:include and ui:param)?


Design hints

The files which aren't supposed to be publicly accessible by just entering/guessing its URL, need to be placed in /WEB-INF folder, like as the include file and the template file in above example. See also Which XHTML files do I need to put in /WEB-INF and which not?

There doesn't need to be any markup (HTML code) outside <ui:composition> and <ui:define>. You can put any, but they will be ignored by Facelets. Putting markup in there is only useful for web designers. See also Is there a way to run a JSF page without building the whole project?

The HTML5 doctype is the recommended doctype these days, "in spite of" that it's a XHTML file. You should see XHTML as a language which allows you to produce HTML output using a XML based tool. See also Is it possible to use JSF+Facelets with HTML 4/5? and JavaServer Faces 2.2 and HTML5 support, why is XHTML still being used.

CSS/JS/image files can be included as dynamically relocatable/localized/versioned resources. See also How to reference CSS / JS / image resource in Facelets template?

You can put Facelets files in a reusable JAR file. See also Structure for multiple JSF projects with shared code.

For real world examples of advanced Facelets templating, check the src/main/webapp folder of Java EE Kickoff App source code and OmniFaces showcase site source code.

Cannot create JDBC driver of class ' ' for connect URL 'null' : I do not understand this exception

These two things don't match:

driverClassName="org.apache.derby.jdbc.EmbeddedDriver"
url="jdbc:derby://localhost:1527/poll database;create=true"

If you are using the EmbeddedDriver, your URL should not contain network syntax.

Conversely, if you are using network syntax, you need to use the ClientDriver.

http://db.apache.org/derby/docs/10.8/getstart/rgsquck35368.html

How to add an image to a JPanel?

Create a source folder in your project directory, in this case I called it Images.

JFrame snakeFrame = new JFrame();
snakeFrame.setBounds(100, 200, 800, 800);
snakeFrame.setVisible(true);
snakeFrame.add(new JLabel(new ImageIcon("Images/Snake.png")));
snakeFrame.pack();

Change background position with jQuery

Sets new value for backgroundPosition on the carousel div when a li in the submenu div is hovered. Removes the backgroundPosition when hovering ends and resets backgroundPosition to old value.

$('#submenu li').hover(function() {
    if ($('#carousel').data('oldbackgroundPosition')==undefined) {
        $('#carousel').data('oldbackgroundPosition', $('#carousel').css('backgroundPosition'));
    }
    $('#carousel').css('backgroundPosition', [enternewvaluehere]);
},
function() {
    var reset = '';
    if ($('#carousel').data('oldbackgroundPosition') != undefined) {
        reset = $('#carousel').data('oldbackgroundPosition');
        $('#carousel').removeData('oldbackgroundPosition');
    }
    $('#carousel').css('backgroundPosition', reset);
});

NSString with \n or line break

\n\r seems working for me.

I am using Xcode 4.6 with IOS 6.0 as target. Tested on iPhone 4S. Try it by yourself.

Feng Chiu

How do you get the string length in a batch file?

Yes, of course there's an easy way, using vbscript (or powershell).

WScript.Echo Len( WScript.Arguments(0) )

save this as strlen.vbs and on command line

c:\test> cscript //nologo strlen.vbs "abcd"

Use a for loop to capture the result ( or use vbscript entirely for your scripting task)

Certainly beats having to create cumbersome workarounds using batch and there's no excuse not to use it since vbscript is available with each Windows distribution ( and powershell in later).

Date / Timestamp to record when a record was added to the table?

You can make a default constraint on this column that will put a default getdate() as a value.

Example:

alter table dbo.TABLE 
add constraint df_TABLE_DATE default getdate() for DATE_COLUMN

CryptographicException 'Keyset does not exist', but only through WCF

This is the only solution worked for me.

    // creates the CspParameters object and sets the key container name used to store the RSA key pair
    CspParameters cp = new CspParameters();
    cp.KeyContainerName = "MyKeyContainerName"; //Eg: Friendly name

    // instantiates the rsa instance accessing the key container MyKeyContainerName
    RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(cp);
    // add the below line to delete the key entry in MyKeyContainerName
    // rsa.PersistKeyInCsp = false;

    //writes out the current key pair used in the rsa instance
    Console.WriteLine("Key is : \n" + rsa.ToXmlString(true));

Reference 1

Reference 2

How to show the "Are you sure you want to navigate away from this page?" when changes committed?

With JQuery this stuff is pretty easy to do. Since you can bind to sets.

Its NOT enough to do the onbeforeunload, you want to only trigger the navigate away if someone started editing stuff.

dataframe: how to groupBy/count then filter on count in Scala

When you pass a string to the filter function, the string is interpreted as SQL. Count is a SQL keyword and using count as a variable confuses the parser. This is a small bug (you can file a JIRA ticket if you want to).

You can easily avoid this by using a column expression instead of a String:

df.groupBy("x").count()
  .filter($"count" >= 2)
  .show()

How can I bold the fonts of a specific row or cell in an Excel worksheet with C#?

How to Bold entire row 10 example:

workSheet.Cells[10, 1].EntireRow.Font.Bold = true;    

More formally:

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[10, 1] as Xl.Range;
rng.EntireRow.Font.Bold = true;

How to Bold Specific Cell 'A10' for example:

workSheet.Cells[10, 1].Font.Bold = true;

Little more formal:

int row = 1;
int column = 1;  /// 1 = 'A' in Excel

Microsoft.Office.Interop.Excel.Range rng = workSheet.Cells[row, column] as Xl.Range;
rng.Font.Bold = true;

Check if string is upper, lower, or mixed case in Python

There are a number of "is methods" on strings. islower() and isupper() should meet your needs:

>>> 'hello'.islower()
True

>>> [m for m in dir(str) if m.startswith('is')]
['isalnum', 'isalpha', 'isdigit', 'islower', 'isspace', 'istitle', 'isupper']

Here's an example of how to use those methods to classify a list of strings:

>>> words = ['The', 'quick', 'BROWN', 'Fox', 'jumped', 'OVER', 'the', 'Lazy', 'DOG']
>>> [word for word in words if word.islower()]
['quick', 'jumped', 'the']
>>> [word for word in words if word.isupper()]
['BROWN', 'OVER', 'DOG']
>>> [word for word in words if not word.islower() and not word.isupper()]
['The', 'Fox', 'Lazy']

Eclipse error, "The selection cannot be launched, and there are no recent launches"

Eclipse can't work out what you want to run and since you've not run anything before, it can't try re-running that either.

Instead of clicking the green 'run' button, click the dropdown next to it and chose Run Configurations. On the Android tab, make sure it's set to your project. In the Target tab, set the tick box and options as appropriate to target your device. Then click Run. Keep an eye on your Console tab in Eclipse - that'll let you know what's going on. Once you've got your run configuration set, you can just hit the green 'run' button next time.

Sometimes getting everything to talk to your device can be problematic to begin with. Consider using an AVD (i.e. an emulator) as alternative, at least to begin with if you have problems. You can easily create one from the menu Window -> Android Virtual Device Manager within Eclipse.

To view the progress of your project being installed and started on your device, check the console. It's a panel within Eclipse with the tabs Problems/Javadoc/Declaration/Console/LogCat etc. It may be minimised - check the tray in the bottom right. Or just use Window/Show View/Console from the menu to make it come to the front. There are two consoles, Android and DDMS - there is a dropdown by its icon where you can switch.

Alarm Manager Example

This code will help you to make a repeating alarm. The repeating time can set by you.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
     <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical" 
     android:background="#000000"
     android:paddingTop="100dp">

    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:gravity="center" >

    <EditText
        android:id="@+id/ethr"
    android:layout_width="50dp"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="Hr"
    android:singleLine="true" >


        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/etmin"
    android:layout_width="55dp"
    android:layout_height="wrap_content"

    android:ems="10"
    android:hint="Min"
    android:singleLine="true" />

    <EditText
        android:id="@+id/etsec"
    android:layout_width="50dp"
    android:layout_height="wrap_content"

    android:ems="10"
    android:hint="Sec"
    android:singleLine="true" />

    </LinearLayout>

   <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content" 
    android:gravity="center"
    android:paddingTop="10dp">


    <Button
        android:id="@+id/setAlarm"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onClickSetAlarm"
        android:text="Set Alarm" />

</LinearLayout>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity {
    int hr = 0;
    int min = 0;
    int sec = 0;
    int result = 1;

    AlarmManager alarmManager;
    PendingIntent pendingIntent;
    BroadcastReceiver mReceiver;

    EditText ethr;
    EditText etmin;
    EditText etsec;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ethr = (EditText) findViewById(R.id.ethr);
        etmin = (EditText) findViewById(R.id.etmin);
        etsec = (EditText) findViewById(R.id.etsec);
        RegisterAlarmBroadcast();
    } 

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

    @Override
    protected void onDestroy() {
        unregisterReceiver(mReceiver);
        super.onDestroy();
    }

    public void onClickSetAlarm(View v) {
        String shr = ethr.getText().toString();
        String smin = etmin.getText().toString();
        String ssec = etsec.getText().toString();

        if(shr.equals("")) 
            hr = 0;
        else {
            hr = Integer.parseInt(ethr.getText().toString());
            hr=hr*60*60*1000;
        }

        if(smin.equals(""))
            min = 0;
        else {
            min = Integer.parseInt(etmin.getText().toString());
            min = min*60*1000;
        }

        if(ssec.equals(""))
            sec = 0;
        else {
             sec = Integer.parseInt(etsec.getText().toString());
             sec = sec * 1000;
        }
        result = hr+min+sec;
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), result , pendingIntent); 
    }

    private void RegisterAlarmBroadcast() {
        mReceiver = new BroadcastReceiver() {
            // private static final String TAG = "Alarm Example Receiver";
            @Override
            public void onReceive(Context context, Intent intent) {
                Toast.makeText(context, "Alarm time has been reached", Toast.LENGTH_LONG).show();
            }
        };

        registerReceiver(mReceiver, new IntentFilter("sample"));
        pendingIntent = PendingIntent.getBroadcast(this, 0, new Intent("sample"), 0);
        alarmManager = (AlarmManager)(this.getSystemService(Context.ALARM_SERVICE));
    }

    private void UnregisterAlarmBroadcast() {
        alarmManager.cancel(pendingIntent); 
        getBaseContext().unregisterReceiver(mReceiver);
    }
}

If you need alarm only for a single time then replace

alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), result , pendingIntent);

with

 alarmManager.set( AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + result , pendingIntent );

"Large data" workflows using pandas

Why Pandas ? Have you tried Standard Python ?

The use of standard library python. Pandas is subject to frequent updates, even with the recent release of the stable version.

Using the standard python library your code will always run.

One way of doing it is to have an idea of the way you want your data to be stored , and which questions you want to solve regarding the data. Then draw a schema of how you can organise your data (think tables) that will help you query the data, not necessarily normalisation.

You can make good use of :

  • list of dictionaries to store the data in memory (Think Amazon EC2) or disk, one dict being one row,
  • generators to process the data row after row to not overflow your RAM,
  • list comprehension to query your data,
  • make use of Counter, DefaultDict, ...
  • store your data on your hard drive using whatever storing solution you have chosen, json could be one of them.

Ram and HDD is becoming cheaper and cheaper with time and standard python 3 is widely available and stable.

The fondamental question you are trying to solve is "how to query large sets of data ?". The hdfs architecture is more or less what I am describing here (data modelling with data being stored on disk).

Let's say you have 1000 petabytes of data, there no way you will be able to store it in Dask or Pandas, your best chances here is to store it on disk and process it with generators.

Failure during conversion to COFF: file invalid or corrupt

Had to install VS 2010 SP1 in order to get it to work again for myself. Lame microsoft.

Angular 2 change event - model changes

If this helps you,

<input type="checkbox"  (ngModelChange)="mychange($event)" [ngModel]="mymodel">

mychange(val)
{
   console.log(val); // updated value
}

In Java, how do you determine if a thread is running?

You can use: Thread.currentThread().isAlive();. Returns true if this thread is alive; false otherwise.

What's the "average" requests per second for a production web application?

OpenStreetMap seems to have 10-20 per second

Wikipedia seems to be 30000 to 70000 per second spread over 300 servers (100 to 200 requests per second per machine, most of which is caches)

Geograph is getting 7000 images per week (1 upload per 95 seconds)

How to use an environment variable inside a quoted string in Bash

Just a quick note/summary for any who came here via Google looking for the answer to the general question asked in the title (as I was). Any of the following should work for getting access to shell variables inside quotes:

echo "$VARIABLE"
echo "${VARIABLE}"

Use of single quotes is the main issue. According to the Bash Reference Manual:

Enclosing characters in single quotes (') preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash. [...] Enclosing characters in double quotes (") preserves the literal value of all characters within the quotes, with the exception of $, `, \, and, when history expansion is enabled, !. The characters $ and ` retain their special meaning within double quotes (see Shell Expansions). The backslash retains its special meaning only when followed by one of the following characters: $, `, ", \, or newline. Within double quotes, backslashes that are followed by one of these characters are removed. Backslashes preceding characters without a special meaning are left unmodified. A double quote may be quoted within double quotes by preceding it with a backslash. If enabled, history expansion will be performed unless an ! appearing in double quotes is escaped using a backslash. The backslash preceding the ! is not removed. The special parameters * and @ have special meaning when in double quotes (see Shell Parameter Expansion).

In the specific case asked in the question, $COLUMNS is a special variable which has nonstandard properties (see lhunath's answer above).

Can I pass an argument to a VBScript (vbs file launched with cscript)?

To answer your bonus question, the general answer is no, you don't need to set variables to "Nothing" in short .VBS scripts like yours, that get called by Wscript or Cscript.

The reason you might do this in the middle of a longer script is to release memory back to the operating system that VB would otherwise have been holding. These days when 8GB of RAM is typical and 16GB+ relatively common, this is unlikely to produce any measurable impact, even on a huge script that has several megabytes in a single variable. At this point it's kind of a hold-over from the days where you might have been working in 1MB or 2MB of RAM.

You're correct, the moment your .VBS script completes, all of your variables get destroyed and the memory is reclaimed anyway. Setting variables to "Nothing" simply speeds up that process, and allows you to do it in the middle of a script.

HTML5 video (mp4 and ogv) problems in Safari and Firefox - but Chrome is all good

The HTTP Content-Type for .ogg should be application/ogg (video/ogg for .ogv) and for .mp4 it should be video/mp4. You can check using the Web Sniffer.

Error: cannot open display: localhost:0.0 - trying to open Firefox from CentOS 6.2 64bit and display on Win7

So, it turns out that X11 wasn't actually installed on the centOS. There didn't seem to be any indication anywhere of it not being installed. I did the following command and now firefox opens:

yum groupinstall 'X Window System' 

Hope this answer will help others that are confused :)

How to compare two JSON objects with the same elements in a different order equal?

You can write your own equals function:

  • dicts are equal if: 1) all keys are equal, 2) all values are equal
  • lists are equal if: all items are equal and in the same order
  • primitives are equal if a == b

Because you're dealing with json, you'll have standard python types: dict, list, etc., so you can do hard type checking if type(obj) == 'dict':, etc.

Rough example (not tested):

def json_equals(jsonA, jsonB):
    if type(jsonA) != type(jsonB):
        # not equal
        return False
    if type(jsonA) == dict:
        if len(jsonA) != len(jsonB):
            return False
        for keyA in jsonA:
            if keyA not in jsonB or not json_equal(jsonA[keyA], jsonB[keyA]):
                return False
    elif type(jsonA) == list:
        if len(jsonA) != len(jsonB):
            return False
        for itemA, itemB in zip(jsonA, jsonB):
            if not json_equal(itemA, itemB):
                return False
    else:
        return jsonA == jsonB

async for loop in node.js

I like to use the recursive pattern for this scenario. For example, something like this:

// If config is an array of queries
var config = JSON.parse(queries.querrryArray);   

// Array of results
var results;

processQueries(config);

function processQueries(queries) {
    var searchQuery;

    if (queries.length == 0) {
        // All queries complete
        res.writeHead(200, {'content-type': 'application/json'});
        res.end(JSON.stringify({results: results}));
        return;
    }

    searchQuery = queries.pop();

    search(searchQuery, function(result) {
        results.push(JSON.stringify({result: result}); 
        processQueries();            
    });

}

processQueries is a recursive function that will pull a query element out of an array of queries to process. Then the callback function calls processQueries again when the query is complete. The processQueries knows to end when there are no queries left.

It is easiest to do this using arrays, but it could be modified to work with object key/values I imagine.

Goal Seek Macro with Goal as a Formula

I think your issue is that Range("H18") doesn't contain a formula. Also, you could make your code more efficient by eliminating x. Instead, change your code to

Range("H18").GoalSeek Goal:=Range("H32").Value, ChangingCell:=Range("G18")

Python string to unicode

>>> a="Hello\u2026"
>>> print a.decode('unicode-escape')
Hello…

How do I assign a null value to a variable in PowerShell?

These are automatic variables, like $null, $true, $false etc.

about_Automatic_Variables, see https://technet.microsoft.com/en-us/library/hh847768.aspx?f=255&MSPPError=-2147217396

$NULL
$null is an automatic variable that contains a NULL or empty value. You can use this variable to represent an absent or undefined value in commands and scripts.

Windows PowerShell treats $null as an object with a value, that is, as an explicit placeholder, so you can use $null to represent an empty value in a series of values.

For example, when $null is included in a collection, it is counted as one of the objects.

C:\PS> $a = ".dir", $null, ".pdf"
C:\PS> $a.count
3

If you pipe the $null variable to the ForEach-Object cmdlet, it generates a value for $null, just as it does for the other objects.

PS C:\ps-test> ".dir", $null, ".pdf" | Foreach {"Hello"}
Hello
Hello
Hello

As a result, you cannot use $null to mean "no parameter value." A parameter value of $null overrides the default parameter value.

However, because Windows PowerShell treats the $null variable as a placeholder, you can use it scripts like the following one, which would not work if $null were ignored.

$calendar = @($null, $null, “Meeting”, $null, $null, “Team Lunch”, $null)
$days = Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"
$currentDay = 0

foreach($day in $calendar)
{
    if($day –ne $null)
    {
        "Appointment on $($days[$currentDay]): $day"
    }

    $currentDay++
}

output:

Appointment on Tuesday: Meeting
Appointment on Friday: Team lunch

How does @synchronized lock/unlock in Objective-C?

Apple's implementation of @synchronized is open source and it can be found here. Mike ash wrote two really interesting post about this subject:

In a nutshell it has a table that maps object pointers (using their memory addresses as keys) to pthread_mutex_t locks, which are locked and unlocked as needed.

How to make several plots on a single page using matplotlib?

@doug & FS.'s answer are very good solutions. I want to share the solution for iteration on pandas.dataframe.

import pandas as pd
df=pd.DataFrame([[1, 2], [3, 4], [4, 3], [2, 3]])
fig = plt.figure(figsize=(14,8))
for i in df.columns:
    ax=plt.subplot(2,1,i+1) 
    df[[i]].plot(ax=ax)
    print(i)
plt.show()

Background images: how to fill whole div if image is small and vice versa

This will work like a charm.

background-image:url("http://assets.toptal.io/uploads/blog/category/logo/4/php.png");
background-repeat: no-repeat;
background-size: contain;

How to move an element into another element?

If you want a quick demo and more details about how you move elements, try this link:

http://html-tuts.com/move-div-in-another-div-with-jquery


Here is a short example:

To move ABOVE an element:

$('.whatToMove').insertBefore('.whereToMove');

To move AFTER an element:

$('.whatToMove').insertAfter('.whereToMove');

To move inside an element, ABOVE ALL elements inside that container:

$('.whatToMove').prependTo('.whereToMove');

To move inside an element, AFTER ALL elements inside that container:

$('.whatToMove').appendTo('.whereToMove');

Can local storage ever be considered secure?

WebCrypto

The concerns with cryptography in client-side (browser) javascript are detailed below. All but one of these concerns does not apply to the WebCrypto API, which is now reasonably well supported.

For an offline app, you must still design and implement a secure keystore.

Aside: If you are using Node.js, use the builtin crypto API.

Native-Javascript Cryptography (pre-WebCrypto)

I presume the primary concern is someone with physical access to the computer reading the localStorage for your site, and you want cryptography to help prevent that access.

If someone has physical access you are also open to attacks other and worse than reading. These include (but are not limited to): keyloggers, offline script modification, local script injection, browser cache poisoning, and DNS redirects. Those attacks only work if the user uses the machine after it has been compromised. Nevertheless, physical access in such a scenario means you have bigger problems.

So keep in mind that the limited scenario where local crypto is valuable would be if the machine is stolen.

There are libraries that do implement the desired functionality, e.g. Stanford Javascript Crypto Library. There are inherent weaknesses, though (as referred to in the link from @ircmaxell's answer):

  1. Lack of entropy / random number generation;
  2. Lack of a secure keystore i.e. the private key must be password-protected if stored locally, or stored on the server (which bars offline access);
  3. Lack of secure-erase;
  4. Lack of timing characteristics.

Each of these weaknesses corresponds with a category of cryptographic compromise. In other words, while you may have "crypto" by name, it will be well below the rigour one aspires to in practice.

All that being said, the actuarial assessment is not as trivial as "Javascript crypto is weak, do not use it". This is not an endorsement, strictly a caveat and it requires you to completely understand the exposure of the above weaknesses, the frequency and cost of the vectors you face, and your capacity for mitigation or insurance in the event of failure: Javascript crypto, in spite of its weaknesses, may reduce your exposure but only against thieves with limited technical capacity. However, you should presume Javascript crypto has no value against a determined and capable attacker who is targeting that information. Some would consider it misleading to call the data "encrypted" when so many weaknesses are known to be inherent to the implementation. In other words, you can marginally decrease your technical exposure but you increase your financial exposure from disclosure. Each situation is different, of course - and the analysis of reducing the technical exposure to financial exposure is non-trivial. Here is an illustrative analogy: Some banks require weak passwords, in spite of the inherent risk, because their exposure to losses from weak passwords is less than the end-user costs of supporting strong passwords.

If you read the last paragraph and thought "Some guy on the Internet named Brian says I can use Javascript crypto", do not use Javascript crypto.

For the use case described in the question it would seem to make more sense for users to encrypt their local partition or home directory and use a strong password. That type of security is generally well tested, widely trusted, and commonly available.

Clearing localStorage in javascript?

Use this to clear localStorage:

localStorage.clear();

How to place Text and an Image next to each other in HTML?

You can use vertical-align and floating.

In most cases you want to vertical-align: middle, the image.

Here is a test: http://www.w3schools.com/cssref/tryit.asp?filename=trycss_vertical-align

vertical-align: baseline|length|sub|super|top|text-top|middle|bottom|text-bottom|initial|inherit;

For middle, the definition is: The element is placed in the middle of the parent element.

So you might want to apply that to all elements within the element.

What is the Python equivalent of static variables inside a function?

I write a simple function to use static variables:

def Static():
    ### get the func object by which Static() is called.
    from inspect import currentframe, getframeinfo
    caller = currentframe().f_back
    func_name = getframeinfo(caller)[2]
    # print(func_name)
    caller = caller.f_back
    func = caller.f_locals.get(
        func_name, caller.f_globals.get(
            func_name
        )
    )
    
    class StaticVars:
        def has(self, varName):
            return hasattr(self, varName)
        def declare(self, varName, value):
            if not self.has(varName):
                setattr(self, varName, value)

    if hasattr(func, "staticVars"):
        return func.staticVars
    else:
        # add an attribute to func
        func.staticVars = StaticVars()
        return func.staticVars

How to use:

def myfunc(arg):
    if Static().has('test1'):
        Static().test += 1
    else:
        Static().test = 1
    print(Static().test)

    # declare() only takes effect in the first time for each static variable.
    Static().declare('test2', 1)
    print(Static().test2)
    Static().test2 += 1

When does Java's Thread.sleep throw InterruptedException?

The InterruptedException is usually thrown when a sleep is interrupted.

What is char ** in C?

well, char * means a pointer point to char, it is different from char array.

char amessage[] = "this is an array";  /* define an array*/
char *pmessage = "this is a pointer"; /* define a pointer*/

And, char ** means a pointer point to a char pointer.

You can look some books about details about pointer and array.

Regular expression to match any character being repeated more than 10 times

. matches any character. Used in conjunction with the curly braces already mentioned:

$: cat > test
========
============================
oo
ooooooooooooooooooooooo


$: grep -E '(.)\1{10}' test
============================
ooooooooooooooooooooooo

How can I make a weak protocol reference in 'pure' Swift (without @objc)

Update: It looks like the manual has been updated and the example I was referring to has been removed. See the edit to @flainez's answer above.

Original: Using @objc is the right way to do it even if you're not interoperating with Obj-C. It ensures that your protocol is being applied to a class and not an enum or struct. See "Checking for Protocol Conformance" in the manual.

How to use ESLint with Jest

You can also set the test env in your test file as follows:

/* eslint-env jest */

describe(() => {
  /* ... */
})

Convert a JSON string to object in Java ME?

JSON IO is by far the easiest way to convert a JSON string or JSON input stream to a Java Object

String to Java Object
Object obj = JsonReader.jsonToJava("[\"Hello, World\"]");

https://code.google.com/p/json-io/

How to specify multiple conditions in an if statement in javascript

Here is an alternative way to do that.

const conditionsArray = [
    condition1, 
    condition2,
    condition3,
]

if (conditionsArray.indexOf(false) === -1) {
    "do somthing"
}

Or ES6

if (!conditionsArray.includes(false)) {
   "do somthing"
}

String, StringBuffer, and StringBuilder

Do you mean, for concatenation?

Real world example: You want to create a new string out of many others.

For instance to send a message:

String

String s = "Dear " + user.name + "<br>" + 
" I saw your profile and got interested in you.<br>" +
" I'm  " + user.age + "yrs. old too"

StringBuilder

String s = new StringBuilder().append.("Dear ").append( user.name ).append( "<br>" ) 
          .append(" I saw your profile and got interested in you.<br>") 
          .append(" I'm  " ).append( user.age ).append( "yrs. old too")
          .toString()

Or

String s = new StringBuilder(100).appe..... etc. ...
// The difference is a size of 100 will be allocated upfront as  fuzzy lollipop points out.

StringBuffer ( the syntax is exactly as with StringBuilder, the effects differ )

About

StringBuffer vs. StringBuilder

The former is synchonized and later is not.

So, if you invoke it several times in a single thread ( which is 90% of the cases ), StringBuilder will run much faster because it won't stop to see if it owns the thread lock.

So, it is recommendable to use StringBuilder ( unless of course you have more than one thread accessing to it at the same time, which is rare )

String concatenation ( using the + operator ) may be optimized by the compiler to use StringBuilder underneath, so, it not longer something to worry about, in the elder days of Java, this was something that everyone says should be avoided at all cost, because every concatenation created a new String object. Modern compilers don't do this anymore, but still it is a good practice to use StringBuilder instead just in case you use an "old" compiler.

edit

Just for who is curious, this is what the compiler does for this class:

class StringConcatenation {
    int x;
    String literal = "Value is" + x;
    String builder = new StringBuilder().append("Value is").append(x).toString();
}

javap -c StringConcatenation

Compiled from "StringConcatenation.java"
class StringConcatenation extends java.lang.Object{
int x;

java.lang.String literal;

java.lang.String builder;

StringConcatenation();
  Code:
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   aload_0
   5:   new #2; //class java/lang/StringBuilder
   8:   dup
   9:   invokespecial   #3; //Method java/lang/StringBuilder."<init>":()V
   12:  ldc #4; //String Value is
   14:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
   17:  aload_0
   18:  getfield    #6; //Field x:I
   21:  invokevirtual   #7; //Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder;
   24:  invokevirtual   #8; //Method java/lang/StringBuilder.toString:()Ljava/lang/String;
   27:  putfield    #9; //Field literal:Ljava/lang/String;
   30:  aload_0
   31:  new #2; //class java/lang/StringBuilder
   34:  dup
   35:  invokespecial   #3; //Method java/lang/StringBuilder."<init>":()V
   38:  ldc #4; //String Value is
   40:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
   43:  aload_0
   44:  getfield    #6; //Field x:I
   47:  invokevirtual   #7; //Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder;
   50:  invokevirtual   #8; //Method java/lang/StringBuilder.toString:()Ljava/lang/String;
   53:  putfield    #10; //Field builder:Ljava/lang/String;
   56:  return

}

Lines numbered 5 - 27 are for the String named "literal"

Lines numbered 31-53 are for the String named "builder"

Ther's no difference, exactly the same code is executed for both strings.

How to Access Hive via Python?

here's a generic approach which makes it easy for me because I keep connecting to several servers (SQL, Teradata, Hive etc.) from python. Hence, I use the pyodbc connector. Here's some basic steps to get going with pyodbc (in case you have never used it):

  • Pre-requisite: You should have the relevant ODBC connection in your windows setup before you follow the below steps. In case you don't have it, find the same here

Once complete: STEP 1. pip install: pip install pyodbc (here's the link to download the relevant driver from Microsoft's website)

STEP 2. now, import the same in your python script:

import pyodbc

STEP 3. Finally, go ahead and give the connection details as follows:

conn_hive = pyodbc.connect('DSN = YOUR_DSN_NAME , SERVER = YOUR_SERVER_NAME, UID = USER_ID, PWD = PSWD' )

The best part of using pyodbc is that I have to import just one package to connect to almost any data source.

Read text file into string array (and write)

As of Go1.1 release, there is a bufio.Scanner API that can easily read lines from a file. Consider the following example from above, rewritten with Scanner:

package main

import (
    "bufio"
    "fmt"
    "log"
    "os"
)

// readLines reads a whole file into memory
// and returns a slice of its lines.
func readLines(path string) ([]string, error) {
    file, err := os.Open(path)
    if err != nil {
        return nil, err
    }
    defer file.Close()

    var lines []string
    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        lines = append(lines, scanner.Text())
    }
    return lines, scanner.Err()
}

// writeLines writes the lines to the given file.
func writeLines(lines []string, path string) error {
    file, err := os.Create(path)
    if err != nil {
        return err
    }
    defer file.Close()

    w := bufio.NewWriter(file)
    for _, line := range lines {
        fmt.Fprintln(w, line)
    }
    return w.Flush()
}

func main() {
    lines, err := readLines("foo.in.txt")
    if err != nil {
        log.Fatalf("readLines: %s", err)
    }
    for i, line := range lines {
        fmt.Println(i, line)
    }

    if err := writeLines(lines, "foo.out.txt"); err != nil {
        log.Fatalf("writeLines: %s", err)
    }
}

How to declare global variables in Android?

On activity result is called before on resume. So move you login check to on resume and your second login can be blocked once the secomd activity has returned a positive result. On resume is called every time so there is not worries of it not being called the first time.

SQL - Select first 10 rows only?

In standard SQL you can use:

... FETCH FIRST 10 ROWS ONLY

This is supported in DB2, PostgreSQL and Oracle 12.1 (and later)

How to include bootstrap css and js in reactjs app?

Since Bootstrap/Reactstrap has released their latest version i.e. Bootstrap 4 you can use this by following these steps

  1. Navigate to your project
  2. Open the terminal
  3. I assume npm is already installed and then type the following command

    npm install --save reactstrap react react-dom

This will install Reactstrap as a dependency in your project.

Here is the code for a button created using Reactstrap

_x000D_
_x000D_
import React from 'react';_x000D_
import { Button } from 'reactstrap';_x000D_
_x000D_
export default (props) => {_x000D_
  return (_x000D_
    <Button color="danger">Danger!</Button>_x000D_
  );_x000D_
};
_x000D_
_x000D_
_x000D_

You can check the Reactstrap by visiting their offical page

How to replace substrings in windows batch file

Expanding from Andriy M, and yes you can do this from a file, even one with multiple lines

@echo off
setlocal EnableExtensions EnableDelayedExpansion
set "INTEXTFILE=test.txt"
set "OUTTEXTFILE=test_out.txt"
set "SEARCHTEXT=bath"
set "REPLACETEXT=hello"

for /f "delims=" %%A in ('type "%INTEXTFILE%"') do (
    set "string=%%A"
    set "modified=!string:%SEARCHTEXT%=%REPLACETEXT%!"
    echo !modified!>>"%OUTTEXTFILE%"
)

del "%INTEXTFILE%"
rename "%OUTTEXTFILE%" "%INTEXTFILE%"
endlocal

EDIT

Thanks David Nelson, I have updated the script so it doesn't have the hard coded values anymore.

How to change bower's default components folder?

Hi i am same problem and resolve this ways.

windows user and vs cant'create .bowerrc file.

in cmd go any folder

install any packages which is contains .bowerrc file forexample

bower install angular-local-storage

this plugin contains .bowerrc file. copy that and go to your project and paste this file.

and in visual studio - solution explorer - show all files and include project seen .bowerrc file

i resolve this ways :)

round() for float in C++

It's usually implemented as floor(value + 0.5).

Edit: and it's probably not called round since there are at least three rounding algorithms I know of: round to zero, round to closest integer, and banker's rounding. You are asking for round to closest integer.

Get current date/time in seconds

These JavaScript solutions give you the milliseconds or the seconds since the midnight, January 1st, 1970.

The IE 9+ solution(IE 8 or the older version doesn't support this.):

var timestampInMilliseconds = Date.now();
var timestampInSeconds = Date.now() / 1000; // A float value; not an integer.
    timestampInSeconds = Math.floor(Date.now() / 1000); // Floor it to get the seconds.
    timestampInSeconds = Date.now() / 1000 | 0; // Also you can do floor it like this.
    timestampInSeconds = Math.round(Date.now() / 1000); // Round it to get the seconds.

To get more information about Date.now(): https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/now

The generic solution:

// ‘+’ operator makes the operand numeric.
// And ‘new’ operator can be used without the arguments ‘(……)’.
var timestampInMilliseconds = +new Date;
var timestampInSeconds = +new Date / 1000; // A float value; not an intger.
    timestampInSeconds = Math.floor(+new Date / 1000); // Floor it to get the seconds.
    timestampInSeconds = +new Date / 1000 | 0; // Also you can do floor it like this.
    timestampInSeconds = Math.round(+new Date / 1000); // Round it to get the seconds.

Be careful to use, if you don't want something like this case.

if(1000000 < Math.round(1000000.2)) // false.

Using ls to list directories and their total sizes

I ran into an issue similar to what Martin Wilde described, in my case comparing the same directory on two different servers after mirroring with rsync.

Instead of using a script I added the -b flag to the du which counts the size in bytes and as far as I can determine eliminated the differences on the two servers. You still can use -s -h to get a comprehensible output.

Can't use Swift classes inside Objective-C

I just discovered that adding a directory of swift files to a project won't work. You need to create a group first for the directory, then add the swift files...

Difference between jQuery’s .hide() and setting CSS to display: none

They are the same thing. .hide() calls a jQuery function and allows you to add a callback function to it. So, with .hide() you can add an animation for instance.

.css("display","none") changes the attribute of the element to display:none. It is the same as if you do the following in JavaScript:

document.getElementById('elementId').style.display = 'none';

The .hide() function obviously takes more time to run as it checks for callback functions, speed, etc...

How to add more than one machine to the trusted hosts list using winrm

I created a module to make dealing with trusted hosts slightly easier, psTrustedHosts. You can find the repo here on GitHub. It provides four functions that make working with trusted hosts easy: Add-TrustedHost, Clear-TrustedHost, Get-TrustedHost, and Remove-TrustedHost. You can install the module from PowerShell Gallery with the following command:

Install-Module psTrustedHosts -Force

In your example, if you wanted to append hosts 'machineC' and 'machineD' you would simply use the following command:

Add-TrustedHost 'machineC','machineD'

To be clear, this adds hosts 'machineC' and 'machineD' to any hosts that already exist, it does not overwrite existing hosts.

The Add-TrustedHost command supports pipeline processing as well (so does the Remove-TrustedHost command) so you could also do the following:

'machineC','machineD' | Add-TrustedHost

Change Select List Option background colour on hover

this is what you need, the child combinator:

    select>option:hover
    {
        color: #1B517E;
        cursor: pointer;
    }

Try it, works perfect.

Here's the reference: http://www.w3schools.com/css/css_combinators.asp