Programs & Examples On #Enscript

Enscript is a program that can convert source code files into PostScript files.

How to list AD group membership for AD users using input list?

Everything in one line:

get-aduser -filter * -Properties memberof | select name, @{ l="GroupMembership"; e={$_.memberof  -join ";"  } } | export-csv membership.csv

Include jQuery in the JavaScript Console

Post 2020 method, using dynamic import, self executing IIFE, asynchronous function!

(async () => {
    await import('')
    // Library ready

enter image description here

Another example

Unzipping files in Python

from zipfile import ZipFile

The directory where you will extract your files doesn't need to exist before, you name it at this moment is the name of the zip if your project is in the same directory. If not, use the PATH i.e : C://....//

Think to escape the / by an other / in the PATH If you have a permission denied try to launch your ide (i.e: Anaconda) as administrator

YOUR_DESTINATION_DIRECTORY will be created in the same directory than your project

Python regular expressions return true/false

Match objects are always true, and None is returned if there is no match. Just test for trueness.

if re.match(...):

How to convert std::string to lower case?

As far as I see Boost libraries are really bad performance-wise. I have tested their unordered_map to STL and it was average 3 times slower (best case 2, worst was 10 times). Also this algorithm looks too low.

The difference is so big that I am sure whatever addition you will need to do to tolower to make it equal to boost "for your needs" will be way faster than boost.

I have done these tests on an Amazon EC2, therefore performance varied during the test but you still get the idea.

Elapsed time: 12365milliseconds
Elapsed time: 1640milliseconds
Elapsed time: 26978milliseconds
Elapsed time: 1646milliseconds
Elapsed time: 6957milliseconds
Elapsed time: 1634milliseconds
Elapsed time: 23177milliseconds
Elapsed time: 2421milliseconds
Elapsed time: 17342milliseconds
Elapsed time: 14132milliseconds
Elapsed time: 7355milliseconds
Elapsed time: 1645milliseconds

-O2 made it like this:

Elapsed time: 3769milliseconds
Elapsed time: 565milliseconds
Elapsed time: 3815milliseconds
Elapsed time: 565milliseconds
Elapsed time: 3643milliseconds
Elapsed time: 566milliseconds
Elapsed time: 22018milliseconds
Elapsed time: 566milliseconds
Elapsed time: 3845milliseconds
Elapsed time: 569milliseconds


string str;
for(long long i=0;i<1000000;i++)

for(long long i=0;i<1000000;i++)
    for(unsigned short loop=0;loop < str.size();loop++)

I guess I should to the tests on a dedicated machine but I will be using this EC2 so I do not really need to test it on my machine.

What does localhost:8080 mean?

http uses port 80, and understandably, your internet browser will automatically use that port when you type in an address - unless you specify another port. Now, when running a web server on your computer, you need to access that server somehow - and since port 80 is already busy, you need to use a different port to successfully connect to it. Although any open port is fair game, usually such a server is configured to use port 8080, hence when accessing your server you type in:

http:// (protocol) localhost (your computer) :8080 (port 8080) / (path pointing to the root of the public folder of your server)

PostgreSQL ERROR: canceling statement due to conflict with recovery

There's no need to start idle transactions on the master. In postgresql-9.1 the most direct way to solve this problem is by setting

hot_standby_feedback = on

This will make the master aware of long-running queries. From the docs:

The first option is to set the parameter hot_standby_feedback, which prevents VACUUM from removing recently-dead rows and so cleanup conflicts do not occur.

Why isn't this the default? This parameter was added after the initial implementation and it's the only way that a standby can affect a master.

Event system in Python

I've been doing it this way:

class Event(list):
    """Event subscription.

    A list of callable objects. Calling an instance of this will cause a
    call to each item in the list in ascending order by index.

    Example Usage:
    >>> def f(x):
    ...     print 'f(%s)' % x
    >>> def g(x):
    ...     print 'g(%s)' % x
    >>> e = Event()
    >>> e()
    >>> e.append(f)
    >>> e(123)
    >>> e.remove(f)
    >>> e()
    >>> e += (f, g)
    >>> e(10)
    >>> del e[0]
    >>> e(2)

    def __call__(self, *args, **kwargs):
        for f in self:
            f(*args, **kwargs)

    def __repr__(self):
        return "Event(%s)" % list.__repr__(self)

However, like with everything else I've seen, there is no auto generated pydoc for this, and no signatures, which really sucks.

Fitting iframe inside a div

Would this CSS fix it?

iframe {

From this example:

Margin-Top not working for span element?

Always remember one thing we can not apply margin vertically to inline elements ,if you want to apply then change its display type to block or inline block.for example span{display:inline-block;}

Is it possible to install Xcode 10.2 on High Sierra (10.13.6)?

Download xcode 10.2 from below link

Edit: Minimum System Version* to 10.13.6 in Info.plist at below paths


Replace: from Xcode 10


you can install disk image of 12.2 in your existing xcode to run on 12.2 devices Download disk image from here

And paste at Path: /Applications/

Note: Restart the Xcode

gnuplot plotting multiple line graphs

andyras is completely correct. One minor addition, try this (for example)

plot 'ls.dat' using 4:xtic(1)

This will keep your datafile in the correct order, but also preserve your version tic labels on the x-axis.

Redirect after Login on WordPress

// add the code to your theme function.php
//for logout redirection
function auto_redirect_after_logout(){
wp_redirect( home_url() );
//for login redirection
function auto_redirect_after_login(){
wp_redirect( home_url() );
`enter code here`}

Entity Framework Core: DbContextOptionsBuilder does not contain a definition for 'usesqlserver' and no extension method 'usesqlserver'

Currently working with Entity Framework Core 3.1.3. None of the above solutions fixed my issue.

However, installing the package Microsoft.EntityFrameworkCore.Proxies on my project fixed the issue. Now I can access the UseLazyLoadingProxies() method call when setting my DBContext options.

Hope this helps someone. See the following article:

Lazy Loading in EF Core

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:

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.

Grep characters before and after match?

You could use

awk '/test_pattern/ {
    match($0, /test_pattern/); print substr($0, RSTART - 10, RLENGTH + 20);
}' file

Httpd returning 503 Service Unavailable with mod_proxy for Tomcat 8

this worked for me:

ProxyRequests     Off
ProxyPreserveHost On
RewriteEngine On

<Proxy http://localhost:8123>
Order deny,allow
Allow from all

ProxyPass         /node  http://localhost:8123  
ProxyPassReverse  /node  http://localhost:8123

FlutterError: Unable to load asset

I was also facing the same issue . The issue on my side was that the image name was having the space in between its name so I updated the image name with the new name that does not have any space.

Image name creating the error was comboclr emtpy no circle.png

I updated this name to comboclr_emtpy_no_circle.png

If Browser is Internet Explorer: run an alternative script instead

For IE10+ standard conditions don't work cause of engine change or some another reasons, cause, you know, it's MSIE. But for IE10+ you need to run something like this in your scripts:

if (navigator.userAgent.match(/Trident\/7\./)) {
  // do stuff for IE.

Facebook api: (#4) Application request limit reached

The Facebook API limit isn't really documented, but apparently it's something like: 600 calls per 600 seconds, per token & per IP. As the site is restricted, quoting the relevant part:

After some testing and discussion with the Facebook platform team, there is no official limit I'm aware of or can find in the documentation. However, I've found 600 calls per 600 seconds, per token & per IP to be about where they stop you. I've also seen some application based rate limiting but don't have any numbers.

As a general rule, one call per second should not get rate limited. On the surface this seems very restrictive but remember you can batch certain calls and use the subscription API to get changes.

As you can access the Graph API on the client side via the Javascript SDK; I think if you travel your request for photos from the client, you won't hit any application limit as it's the user (each one with unique id) who's fetching data, not your application server (unique ID).

This may mean a huge refactor if everything you do go through a server. But it seems like the best solution if you have so many request (as it'll give a breath to your server).

Else, you can try batch request, but I guess you're already going this way if you have big traffic.

If nothing of this works, according to the Facebook Platform Policy you should contact them.

If you exceed, or plan to exceed, any of the following thresholds please contact us as you may be subject to additional terms: (>5M MAU) or (>100M API calls per day) or (>50M impressions per day).

How do you get an iPhone's device name

For xamarin user, use this


What does MissingManifestResourceException mean and how to fix it?

Recently ran into the same problem, struggled for a bit, found this topic but no answers were correct for me.

My issue was that when I removed main window from my WPF project (it does not have a main window), I forgot to remove StartupUri from App.xaml. I guess this exception can happen if you have a mistake in StartupUri, so in case if anybody is struggling with this - check your StartupUri in App.xaml.

Is there a wikipedia API just for retrieve content summary?

Yes, there is. For example, if you wanted to get the content of the first section of the article Stack Overflow, use a query like this:

The parts mean this:

  • format=xml: Return the result formatter as XML. Other options (like JSON) are available. This does not affect the format of the page content itself, only the enclosing data format.

  • action=query&prop=revisions: Get information about the revisions of the page. Since we don't specify which revision, the latest one is used.

  • titles=Stack%20Overflow: Get information about the page Stack Overflow. It's possible to get the text of more pages in one go, if you separate their names by |.

  • rvprop=content: Return the content (or text) of the revision.

  • rvsection=0: Return only content from section 0.

  • rvparse: Return the content parsed as HTML.

Keep in mind that this returns the whole first section including things like hatnotes (“For other uses …”), infoboxes or images.

There are several libraries available for various languages that make working with API easier, it may be better for you if you used one of them.

Can I try/catch a warning?

If dns_get_record() fails, it should return FALSE, so you can suppress the warning with @ and then check the return value.

How to resize a custom view programmatically?

This is what I did:

View myView;  
myView.getLayoutParams().height = 32;  
myView.getLayoutParams().width = 32;

If there is a view group that this view belongs to, you may also need to call yourViewGroup.requestLayout() for it to take effect.

Jquery Date picker Default Date

Are u using this datepicker ? if yes there are options to set the default Date.If you didn't change anything , by default it will show the current date.

any way this will gives current date

$( ".selector" ).datepicker({ defaultDate: new Date() });

How do I parse JSON into an int?

You may use parseInt :

int id = Integer.parseInt(jsonObj.get("id"));

or better and more directly the getInt method :

int id = jsonObj.getInt("id");

How to get a list of all valid IP addresses in a local network?

If you want to see which IP addresses are in use on a specific subnet then there are several different IP Address managers.

Try Angry IP Scanner or Solarwinds or Advanced IP Scanner

HTML CSS How to stop a table cell from expanding

It's entirely possible if your code has enough relative logic to work with.

Simply use the viewport units though for some the math may be a bit more complicated. I used this to prevent list items from bloating certain table columns with much longer text.

ol {max-width: 10vw; padding: 0; overflow: hidden;}

Apparently max-width on colgroup elements do not work which is pretty lame to be dependent entirely on child elements to control something on the parent.

Save text file UTF-8 encoded with VBA

You can use CreateTextFile or OpenTextFile method, both have an attribute "unicode" usefull for encoding settings.

object.CreateTextFile(filename[, overwrite[, unicode]])        
object.OpenTextFile(filename[, iomode[, create[, format]]])

Example: Overwrite:

 fileName = "filename"
 Set fso = CreateObject("Scripting.FileSystemObject")
 Set out = fso.CreateTextFile(fileName, True, True)
 out.WriteLine ("Hello world!")

Example: Append:

 OpenTextFile Set fso = CreateObject("Scripting.FileSystemObject")
 Set out = fso.OpenTextFile("filename", ForAppending, True, 1)
 out.Write "Hello world!"

See more on MSDN docs

How to use JQuery with ReactJS

You should try and avoid jQuery in ReactJS. But if you really want to use it, you'd put it in componentDidMount() lifecycle function of the component.


class App extends React.Component {
  componentDidMount() {
    // Jquery here $(...)...

  // ...

Ideally, you'd want to create a reusable Accordion component. For this you could use Jquery, or just use plain javascript + CSS.

class Accordion extends React.Component {
  constructor() {
    this._handleClick = this._handleClick.bind(this);

  componentDidMount() {

  _handleClick() {
    const acc = this._acc.children;
    for (let i = 0; i < acc.length; i++) {
      let a = acc[i];
      a.onclick = () => a.classList.toggle("active");

  render() {
    return (
        ref={a => this._acc = a} 

Then you can use it in any component like so:

class App extends React.Component {
  render() {
    return (
          <div className="accor">
            <div className="head">Head 1</div>
            <div className="body"></div>

Codepen link here: (I changed this link to https ^)

Resize HTML5 canvas to fit window

Setting the canvas coordinate space width and height based on the browser client's dimensions requires you to resize and redraw whenever the browser is resized.

A less convoluted solution is to maintain the drawable dimensions in Javascript variables, but set the canvas dimensions based on the screen.width, screen.height dimensions. Use CSS to fit:

#containingDiv { 
  overflow: hidden;
#myCanvas {
  position: absolute; 
  top: 0px;
  left: 0px;

The browser window generally won't ever be larger than the screen itself (except where the screen resolution is misreported, as it could be with non-matching dual monitors), so the background won't show and pixel proportions won't vary. The canvas pixels will be directly proportional to the screen resolution unless you use CSS to scale the canvas.

How to create dynamic href in react render function?

Could you please try this ?

Create another item in post such as then assign the link to it before send post to the render function. = '/posts/+ id.toString();

So, the above render function should be following instead.

return <li key={}><a href={}>{post.title}</a></li>

NameError: global name is not defined

Importing the namespace is somewhat cleaner. Imagine you have two different modules you import, both of them with the same method/class. Some bad stuff might happen. I'd dare say it is usually good practice to use:

import module


from module import function/class

Cannot delete directory with Directory.Delete(path, true)

The directory or a file in it is locked and cannot be deleted. Find the culprit who locks it and see if you can eliminate it.

FileProvider - IllegalArgumentException: Failed to find configured root

The following change in xml file_paths file worked for me.

 <external-files-path name="my_images" path="Pictures"/>
 <external-files-path name="my_movies" path="Movies"/>

vba: get unique values from array

The Collection and Dictionary solutions are all nice and shine for a short approach, but if you want speed try using a more direct approach:

Function ArrayUnique(ByVal aArrayIn As Variant) As Variant
' ArrayUnique
' This function removes duplicated values from a single dimension array
Dim aArrayOut() As Variant
Dim bFlag As Boolean
Dim vIn As Variant
Dim vOut As Variant
Dim i%, j%, k%

ReDim aArrayOut(LBound(aArrayIn) To UBound(aArrayIn))
i = LBound(aArrayIn)
j = i

For Each vIn In aArrayIn
    For k = j To i - 1
        If vIn = aArrayOut(k) Then bFlag = True: Exit For
    If Not bFlag Then aArrayOut(i) = vIn: i = i + 1
    bFlag = False

If i <> UBound(aArrayIn) Then ReDim Preserve aArrayOut(LBound(aArrayIn) To i - 1)
ArrayUnique = aArrayOut
End Function

Calling it:

Sub Test()
Dim aReturn As Variant
Dim aArray As Variant

aArray = Array(1, 2, 3, 1, 2, 3, "Test", "Test")
aReturn = ArrayUnique(aArray)
End Sub

For speed comparasion, this will be 100x to 130x faster then the dictionary solution, and about 8000x to 13000x faster than the collection one.

Spring Boot and how to configure connection details to MongoDB?

It's also important to note that MongoDB has the concept of "authentication database", which can be different than the database you are connecting to. For example, if you use the official Docker image for Mongo and specify the environment variables MONGO_INITDB_ROOT_USERNAME and MONGO_INITDB_ROOT_PASSWORD, a user will be created on 'admin' database, which is probably not the database you want to use. In this case, you should specify parameters accordingly on your file using:<username specified on MONGO_INITDB_ROOT_USERNAME><password specified on MONGO_INITDB_ROOT_PASSWORD><the db you want to use>

SQL Server returns error "Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'." in Windows application

One of my SQL jobs had the same issue. It involved uploadaing data from one server to another. The error occurred because I was using sql Server Agent Service Account. I created a Credential using a UserId (that uses Window authentication) common to all servers. Then created a Proxy using this credential. Used the proxy in sql server job and it is running fine.

When to use MyISAM and InnoDB?

Read about Storage Engines.


The MyISAM storage engine in MySQL.

  • Simpler to design and create, thus better for beginners. No worries about the foreign relationships between tables.
  • Faster than InnoDB on the whole as a result of the simpler structure thus much less costs of server resources. -- Mostly no longer true.
  • Full-text indexing. -- InnoDB has it now
  • Especially good for read-intensive (select) tables. -- Mostly no longer true.
  • Disk footprint is 2x-3x less than InnoDB's. -- As of Version 5.7, this is perhaps the only real advantage of MyISAM.


The InnoDB storage engine in MySQL.

  • Support for transactions (giving you support for the ACID property).
  • Row-level locking. Having a more fine grained locking-mechanism gives you higher concurrency compared to, for instance, MyISAM.
  • Foreign key constraints. Allowing you to let the database ensure the integrity of the state of the database, and the relationships between tables.
  • InnoDB is more resistant to table corruption than MyISAM.
  • Support for large buffer pool for both data and indexes. MyISAM key buffer is only for indexes.
  • MyISAM is stagnant; all future enhancements will be in InnoDB. This was made abundantly clear with the roll out of Version 8.0.

MyISAM Limitations:

  • No foreign keys and cascading deletes/updates
  • No transactional integrity (ACID compliance)
  • No rollback abilities
  • 4,284,867,296 row limit (2^32) -- This is old default. The configurable limit (for many versions) has been 2**56 bytes.
  • Maximum of 64 indexes per table

InnoDB Limitations:

  • No full text indexing (Below-5.6 mysql version)
  • Cannot be compressed for fast, read-only (5.5.14 introduced ROW_FORMAT=COMPRESSED)
  • You cannot repair an InnoDB table

For brief understanding read below links:

  1. MySQL Engines: InnoDB vs. MyISAM – A Comparison of Pros and Cons
  2. MySQL Engines: MyISAM vs. InnoDB
  3. What are the main differences between InnoDB and MyISAM?
  4. MyISAM versus InnoDB
  5. What's the difference between MyISAM and InnoDB?
  6. MySql: MyISAM vs. Inno DB!

"Too many values to unpack" Exception

try unpacking in one variable,

python will handle it as a list,

then unpack from the list

def returnATupleWithThreeValues():
    return (1,2,3)
a = returnATupleWithThreeValues() # a is a list (1,2,3)
print a[0] # list[0] = 1
print a[1] # list[1] = 2
print a[2] # list[2] = 3

Maven Unable to locate the Javac Compiler in:

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

Step 1 : In eclipse go to Windows -> preferences

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

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

Step 4 : Now select tools.jar path

now apply changes and it works fine.

Here is screenshoot

Android Studio Stuck at Gradle Download on create new project

Yes, You can install Gradle manually before Android Studio, first install gradle in any location then add de gladle location to path variable (in Environment Variables Window).

How to while loop until the end of a file in Python without checking for empty line?

for line in f

reads all file to a memory, and that can be a problem.

My offer is to change the original source by replacing stripping and checking for empty line. Because if it is not last line - You will receive at least newline character in it ('\n'). And '.strip()' removes it. But in last line of a file You will receive truely empty line, without any characters. So the following loop will not give You false EOF, and You do not waste a memory:

with open("blablabla.txt", "r") as fl_in:
   while True:
      line = fl_in.readline()

        if not line:

      line = line.strip()
      # do what You want

SQL statement to select all rows from previous day

In SQL Server do like this:

where cast(columnName as date) = cast(getdate() -1 as date)

You should cast both sides of the expression to date to avoid issues with time formatting.

If you need to control interval in more detail, then you should try something like:

declare @start datetime = cast(getdate() - 1 as date)
declare @end datetime = cast(getdate() - 1 as date)
set @end = dateadd(second, 86399, @end)

How can I export data to an Excel file

I was also struggling with a similar issue dealing with exporting data into an Excel spreadsheet using C#. I tried many different methods working with external DLLs and had no luck.

For the export functionality you do not need to use anything dealing with the external DLLs. Instead, just maintain the header and content type of the response.

Here is an article that I found rather helpful. The article talks about how to export data to Excel spreadsheets using ASP.NET.

How do I embed a mp4 movie into my html?

Most likely the TinyMce editor is adding its own formatting to the post. You'll need to see how you can escape TinyMce's editing abilities. The code works fine for me. Is it a wordpress blog?

How to clear browser cache with php?

It seams you need to versionate, so when some change happens browser will catch something new and user won't need to clear browser's cache.

You can do it by subfolders (example /css/v1/style.css) or by filename (example: css/style_v1.css) or even by setting different folders for your website, example:

And use a .htaccess or even change httpd.conf to redirect to your current application.

If's about one image or page:

    <?$time = date("H:i:s");?>
    <img src="myfile.jpg?time=<?$time;?>">

You can use $time on parts when you don't wanna cache. So it will always pull a new image. Versionate it seams a better approach, otherwise it can overload your server. Remember, browser's cache it's not only good to user experience, but also for your server.

Java/ JUnit - AssertTrue vs AssertFalse

The course contains a logical error:

    assertTrue("Book check in failed", ml.checkIn(b1));

    assertFalse("Book was aleready checked in", ml.checkIn(b1));

In the first assert we expect the checkIn to return True (because checkin is succesful). If this would fail we would print a message like "book check in failed. Now in the second assert we expect the checkIn to fail, because the book was checked in already in the first line. So we expect a checkIn to return a False. If for some reason checkin returns a True (which we don't expect) than the message should never be "Book was already checked in", because the checkin was succesful.

Array initializing in Scala

scala> val arr = Array("Hello","World")
arr: Array[java.lang.String] = Array(Hello, World)

Removing double quotes from variables in batch file creates problems with CMD environment

You have an extra double quote at the end, which is adding it back to the end of the string (after removing both quotes from the string).


set widget="a very useful item"
set widget
set widget=%widget:"=%
set widget


widget="a very useful item"
widget=a very useful item

Note: To replace Double Quotes " with Single Quotes ' do the following:

set widget=%widget:"='%

Note: To replace the word "World" (not case sensitive) with BobB do the following:

set widget="Hello World!"
set widget=%widget:world=BobB%
set widget


widget="Hello BobB!"

As far as your initial question goes (save the following code to a batch file .cmd or .bat and run):

SET BathFileAndPath=%~0
ECHO %BathFileAndPath%
ECHO "%BathFileAndPath%"
ECHO %~0


"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd"
C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd
"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd"
C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd
"C:\Users\Test\Documents\Batch Files\Remove Quotes.cmd"
Press any key to continue . . .

%0 is the Script Name and Path.
%1 is the first command line argument, and so on.

REST - HTTP Post Multipart with JSON

If I understand you correctly, you want to compose a multipart request manually from an HTTP/REST console. The multipart format is simple; a brief introduction can be found in the HTML 4.01 spec. You need to come up with a boundary, which is a string not found in the content, let’s say HereGoes. You set request header Content-Type: multipart/form-data; boundary=HereGoes. Then this should be a valid request body:

Content-Disposition: form-data; name="myJsonString"
Content-Type: application/json

{"foo": "bar"}
Content-Disposition: form-data; name="photo"
Content-Type: image/jpeg
Content-Transfer-Encoding: base64

<...JPEG content in base64...>

How can I delete a service in Windows?

Before removing the service you should review the dependencies.

You can check it:

Open services.msc and find the service name, switch to the "Dependencies" tab.


No increment operator (++) in Ruby?

Ruby has no pre/post increment/decrement operator. For instance, x++ or x-- will fail to parse. More importantly, ++x or --x will do nothing! In fact, they behave as multiple unary prefix operators: -x == ---x == -----x == ...... To increment a number, simply write x += 1.

Taken from "Things That Newcomers to Ruby Should Know " (archive, mirror)

That explains it better than I ever could.

EDIT: and the reason from the language author himself (source):

  1. ++ and -- are NOT reserved operator in Ruby.
  2. C's increment/decrement operators are in fact hidden assignment. They affect variables, not objects. You cannot accomplish assignment via method. Ruby uses +=/-= operator instead.
  3. self cannot be a target of assignment. In addition, altering the value of integer 1 might cause severe confusion throughout the program.

How to change date format in JavaScript

var month = mydate.getMonth(); // month (in integer 0-11)
var year = mydate.getFullYear(); // year

Then all you would need to have is an array of months:

var months = ['Jan', 'Feb', 'Mar', ...];

And then to show it:

alert(months[month] + "  " + year);

Check if a value exists in ArrayList

public static void linktest()
    driver=new ChromeDriver();
    //List<WebElement> allLinkElements=(List<WebElement>) driver.findElement(By.xpath("//a"));
    //int linkcount=allLinkElements.size();
    List<WebElement> link = driver.findElements(By.tagName("a"));
    String data="HOME";
    int linkcount=link.size();
    for(int i=0;i<link.size();i++) { 
        if(link.get(i).getText().contains(data)) {

How to convert a String into an ArrayList?

If you're using guava (and you should be, see effective java item #15):

ImmutableList<String> list = ImmutableList.copyOf(s.split(","));

How to recover the deleted files using "rm -R" command in linux server?

Not possible with standard unix commands. You might have luck with a file recovery utility. Also, be aware, using rm changes the table of contents to mark those blocks as available to be overwritten, so simply using your computer right now risks those blocks being overwritten permanently. If it's critical data, you should turn off the computer before the file sectors gets overwritten. Good luck!

Some restore utility:

Forum where this was previously answered:

Git Remote: Error: fatal: protocol error: bad line length character: Unab

FYI I got this same error message after I upgraded a CentOS6 container to CentOS7 -- some git operations started failing when building the container, e.g.

# git remote show origin
fatal: protocol error: bad line length character: Inva

Running ssh gave me an error I could search on:

# ssh [email protected]
Invalid clock_id for clock_gettime: 7

That led me to where I realized I had forgotten I had a LD_PRELOAD=/usr/local/lib/faketime/ in a parent Dockerfile. Commenting that out fixed the error.

Load image from url

Try this add picasso lib jar file


How to get the indices list of all NaN value in numpy array?

Since x!=x returns the same boolean array with np.isnan(x) (because np.nan!=np.nan would return True), you could also write:


However, I still recommend writing np.argwhere(np.isnan(x)) since it is more readable. I just try to provide another way to write the code in this answer.

Type or namespace name does not exist

Delete the .refresh.dll file if you are under source control. Then rebuild. It should work. This worked for me

Clear form fields with jQuery

if you use selectors and make values to empty values, it is not resetting the form, it's making all fields empty. Reset is to make form as it was before any edit actions from user after the load of form from server side. If there is an input with name "username" and that username was prefilled from server side, most of solutions on this page will delete that value from input, not reset it to the value how it was before user's changes. If you need to reset the form, use this:


if you need not to reset the form, but fill all inputs with some value, for example empty value, then you can use most of the solutions from other comments.

How can I perform static code analysis in PHP?

See Semantic Designs' CloneDR, a "clone detection" tool that finds copy/paste/edited code.

It will find exact and near miss code fragments, in spite of white space, comments and even variable renamings. A sample detection report for PHP can be found at the website. (I'm the author.)

How do I change the select box arrow

You can skip the container or background image with pure css arrow:

select {

  /* make arrow and background */

    linear-gradient(45deg, transparent 50%, blue 50%),
    linear-gradient(135deg, blue 50%, transparent 50%),
    linear-gradient(to right, skyblue, skyblue);
    calc(100% - 21px) calc(1em + 2px),
    calc(100% - 16px) calc(1em + 2px),
    100% 0;
    5px 5px,
    5px 5px,
    2.5em 2.5em;
  background-repeat: no-repeat;

  /* styling and reset */

  border: thin solid blue;
  font: 300 1em/100% "Helvetica Neue", Arial, sans-serif;
  line-height: 1.5em;
  padding: 0.5em 3.5em 0.5em 1em;

  /* reset */

  border-radius: 0;
  margin: 0;      
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;

Sample here

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

Modifying @RaphaelMontanaro's solution, borrowing from @Nosredna's blog, here is what you could do if you just want to identify the duplicate elements from your array.

function identifyDuplicatesFromArray(arr) {
        var i;
        var len = arr.length;
        var obj = {};
        var duplicates = [];

        for (i = 0; i < len; i++) {

            if (!obj[arr[i]]) {

                obj[arr[i]] = {};



        return duplicates;

Thanks for the elegant solution, @Nosredna!

How to change the font size and color of x-axis and y-axis label in a scatterplot with plot function in R?

Look at ?par for the various graphics parameters.

In general cex controls size, col controls colour. If you want to control the colour of a label, the par is col.lab, the colour of the axis annotations col.axis, the colour of the main text, col.main etc. The names are quite intuitive, once you know where to begin.

For example

x <- 1:10
y <- 1:10

plot(x , y,xlab="x axis", ylab="y axis",  pch=19, col.axis = 'blue', col.lab = 'red', cex.axis = 1.5, cex.lab = 2)

enter image description here

If you need to change the colour / style of the surrounding box and axis lines, then look at ?axis or ?box, and you will find that you will be using the same parameter names within calls to box and axis.

You have a lot of control to make things however you wish.


plot(x , y,xlab="x axis", ylab="y axis",  pch=19,  cex.lab = 2, axes = F,col.lab = 'red')
box(col = 'lightblue')
axis(1, col = 'blue', col.axis = 'purple', col.ticks = 'darkred', cex.axis = 1.5, font = 2, family = 'serif')
axis(2, col = 'maroon', col.axis = 'pink', col.ticks = 'limegreen', cex.axis = 0.9, font =3, family = 'mono')

enter image description here

Which is seriously ugly, but shows part of what you can control

Optimum way to compare strings in JavaScript?

You can use the comparison operators to compare strings. A strcmp function could be defined like this:

function strcmp(a, b) {
    if (a.toString() < b.toString()) return -1;
    if (a.toString() > b.toString()) return 1;
    return 0;

Edit    Here’s a string comparison function that takes at most min { length(a), length(b) } comparisons to tell how two strings relate to each other:

function strcmp(a, b) {
    a = a.toString(), b = b.toString();
    for (var i=0,n=Math.max(a.length, b.length); i<n && a.charAt(i) === b.charAt(i); ++i);
    if (i === n) return 0;
    return a.charAt(i) > b.charAt(i) ? -1 : 1;

Typescript: How to define type for a function callback (as any function type, not universal any) used in a method parameter

Hopefully, this will help...

interface Param {
    title: string;
    callback: (error: Error, data: string) => void;

Or in a Function

let myfunction = (title: string, callback: (error: Error, data: string) => void): string => {

    callback(new Error(`Error Message Here.`), "This is callback data.");
    return title;


How to convert this var string to URL in Swift

To Convert file path in String to NSURL, observe the following code

var filePathUrl = NSURL.fileURLWithPath(path)

Running PowerShell as another user, and launching a script

You can open a new powershell window under a specified user credential like this:

start powershell -credential ""

enter image description here

Add border-bottom to table row <tr>

Display the row as a block.

tr {
    display: block;
    border-bottom: 1px solid #000;

and to display alternate colors simply:

tr.oddrow {
    display: block;
    border-bottom: 1px solid #F00;

How to get a thread and heap dump of a Java process on Windows that's not running in a console

Inorder to take thread dump/heap dump from a child java process in windows, you need to identify the child process Id as first step.

By issuing the command: jps you will be able get all java process Ids that are running on your windows machine. From this list you need to select child process Id. Once you have child process Id, there are various options to capture thread dump and heap dumps.

Capturing Thread Dumps:

There are 8 options to capture thread dumps:

  1. jstack
  2. kill -3
  3. jvisualVM
  4. JMC
  5. Windows (Ctrl + Break)
  6. ThreadMXBean
  7. APM Tools
  8. jcmd

Details about each option can be found in this article. Once you have capture thread dumps, you can use tools like fastThread, Samuraito analyze thread dumps.

Capturing Heap Dumps:

There are 7 options to capture heap dumps:

  1. jmap

  2. -XX:+HeapDumpOnOutOfMemoryError

  3. jcmd

  4. JVisualVM

  5. JMX

  6. Programmatic Approach

  7. Administrative consoles

Details about each option can be found in this article. Once you have captured heap dump, you may use tools like Eclipse Memory Analysis tool, HeapHero to analyze the captured heap dumps.

Change windows hostname from command line

Use below command to change computer hostname remotely , Require system reboot after change..

psexec.exe -h -e \\\IPADDRESS -u USERNAME -p PASSWORD netdom renamecomputer CurrentComputerName /newname:NewComputerName /force

Multiple commands in an alias for bash

So use a semi-colon:

alias lock='gnome-screensaver; gnome-screen-saver-command --lock'

This doesn't work well if you want to supply arguments to the first command. Alternatively, create a trivial script in your $HOME/bin directory.

Generating matplotlib graphs without a running X server

You need to use the matplotlib API directly rather than going through the pylab interface. There's a good example here:

How can I check for existence of element in std::vector, in one line?

Try std::find

vector<int>::iterator it = std::find(v.begin(), v.end(), 123);


    std::cout<<"Element not found";

How to get status code from webclient?

You can try this code to get HTTP status code from WebException or from OpenReadCompletedEventArgs.Error. It works in Silverlight too because SL does not have WebExceptionStatus.ProtocolError defined.

HttpStatusCode GetHttpStatusCode(System.Exception err)
    if (err is WebException)
        WebException we = (WebException)err;
        if (we.Response is HttpWebResponse)
            HttpWebResponse response = (HttpWebResponse)we.Response;
            return response.StatusCode;
    return 0;

How to change line color in EditText

If you want a flat line, you can do this easily with xml. Here is the xml example:

<layer-list xmlns:android="">
        <shape android:shape="rectangle">
            <stroke android:width="1dp" android:color="#6A9A3A"/>

Replace the shape with a selector if you want to provide different width and color for focused edittext.

How to convert the following json string to java object?

No need to go with GSON for this; Jackson can do either plain Maps/Lists:

ObjectMapper mapper = new ObjectMapper();
Map<String,Object> map = mapper.readValue(json, Map.class);

or more convenient JSON Tree:

JsonNode rootNode = mapper.readTree(json);

By the way, there is no reason why you could not actually create Java classes and do it (IMO) more conveniently:

public class Library {
  public String name;

  public List<Song> songs;
public class Song {
  @JsonProperty("Artist Name") public String artistName;
  @JsonProperty("Song Name") public String songName;

Library lib = mapper.readValue(jsonString, Library.class);

How to set python variables to true or false?

match_var = a==b

that should more than suffice

you cant use a - in a variable name as it thinks that is match (minus) var


print match-var  #prints -1

Scroll event listener javascript

For those who found this question hoping to find an answer that doesn't involve jQuery, you hook into the window "scroll" event using normal event listening. Say we want to add scroll listening to a number of CSS-selector-able elements:

// what should we do when scrolling occurs
var runOnScroll =  function(evt) {
  // not the most exciting thing, but a thing nonetheless

// grab elements as array, rather than as NodeList
var elements = document.querySelectorAll("...");
elements =;

// and then make each element do something on scroll
elements.forEach(function(element) {
  window.addEventListener("scroll", runOnScroll, {passive: true});

(Using the passive attribute to tell the browser that this event won't interfere with scrolling itself)

For bonus points, you can give the scroll handler a lock mechanism so that it doesn't run if we're already scrolling:

// global lock, so put this code in a closure of some sort so you're not polluting.
var locked = false;
var lastCall = false;

var runOnScroll =  function(evt) {
  if(locked) return;

  if (lastCall) clearTimeout(lastCall);
  lastCall = setTimeout(() => {
    // you do this because you want to handle the last
    // scroll event, even if it occurred while another
    // event was being processed.
  }, 200);

  // ...your code goes here...

  locked = false;

Can grep show only words that match search pattern?


Here are the example using ripgrep:

rg -o "(\w+)?th(\w+)?"

It'll match all words matching th.

How to do a simple file search in cmd

Problem with DIR is that it will return wrong answers. If you are looking for DOC in a folder by using DIR *.DOC it will also give you the DOCX. Searching for *.HTM will also give the HTML and so on...

how do I get the bullet points of a <ul> to center with the text?

Add list-style-position: inside to the ul element. (example)

The default value for the list-style-position property is outside.

ul {_x000D_
    text-align: center;_x000D_
    list-style-position: inside;_x000D_

Another option (which yields slightly different results) would be to center the entire ul element:

.parent {_x000D_
  text-align: center;_x000D_
.parent > ul {_x000D_
  display: inline-block;_x000D_
<div class="parent">_x000D_

Can I use Objective-C blocks as properties?

Here's an example of how you would accomplish such a task:

#import <Foundation/Foundation.h>
typedef int (^IntBlock)();

@interface myobj : NSObject
    IntBlock compare;

@property(readwrite, copy) IntBlock compare;


@implementation myobj

@synthesize compare;

- (void)dealloc 
   // need to release the block since the property was declared copy. (for heap
   // allocated blocks this prevents a potential leak, for compiler-optimized 
   // stack blocks it is a no-op)
   // Note that for ARC, this is unnecessary, as with all properties, the memory management is handled for you.
   [compare release];
   [super dealloc];

int main () {
    @autoreleasepool {
        myobj *ob = [[myobj alloc] init]; = ^
            return rand();
        // if not ARC
        [ob release];

    return 0;

Now, the only thing that would need to change if you needed to change the type of compare would be the typedef int (^IntBlock)(). If you need to pass two objects to it, change it to this: typedef int (^IntBlock)(id, id), and change your block to:

^ (id obj1, id obj2)
    return rand();

I hope this helps.

EDIT March 12, 2012:

For ARC, there are no specific changes required, as ARC will manage the blocks for you as long as they are defined as copy. You do not need to set the property to nil in your destructor, either.

For more reading, please check out this document:

How can I use PHP to dynamically publish an ical file to be read by Google Calendar?

Make sure you format the string like this or it wont work

 $content = "BEGIN:VCALENDAR\n".
            "PRODID:-//hacksw/handcal//NONSGML v1.0//EN\n".

C Programming: How to read the whole file contents into a buffer

Portability between Linux and Windows is a big headache, since Linux is a POSIX-conformant system with - generally - a proper, high quality toolchain for C, whereas Windows doesn't even provide a lot of functions in the C standard library.

However, if you want to stick to the standard, you can write something like this:

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

FILE *f = fopen("textfile.txt", "rb");
fseek(f, 0, SEEK_END);
long fsize = ftell(f);
fseek(f, 0, SEEK_SET);  /* same as rewind(f); */

char *string = malloc(fsize + 1);
fread(string, 1, fsize, f);

string[fsize] = 0;

Here string will contain the contents of the text file as a properly 0-terminated C string. This code is just standard C, it's not POSIX-specific (although that it doesn't guarantee it will work/compile on Windows...)

How to change webservice url endpoint?

To add some clarification here, when you create your service, the service class uses the default 'wsdlLocation', which was inserted into it when the class was built from the wsdl. So if you have a service class called SomeService, and you create an instance like this:

SomeService someService = new SomeService();

If you look inside SomeService, you will see that the constructor looks like this:

public SomeService() {
        super(__getWsdlLocation(), SOMESERVICE_QNAME);

So if you want it to point to another URL, you just use the constructor that takes a URL argument (there are 6 constructors for setting qname and features as well). For example, if you have set up a local TCP/IP monitor that is listening on port 9999, and you want to redirect to that URL:

URL newWsdlLocation = new URL("http://theServerName:9999/somePath");
SomeService someService = new SomeService(newWsdlLocation);

and that will call this constructor inside the service:

public SomeService(URL wsdlLocation) {
    super(wsdlLocation, SOMESERVICE_QNAME);

Get file content from URL?

Use file_get_contents in combination with json_decode and echo.

Why would an Enum implement an Interface?

I used an inner enum in an interface describing a strategy to keep instance control (each strategy is a Singleton) from there.

public interface VectorizeStrategy {

     * Keep instance control from here.
     * Concrete classes constructors should be package private.
    enum ConcreteStrategy implements VectorizeStrategy {
        DEFAULT (new VectorizeImpl());

        private final VectorizeStrategy INSTANCE;

        ConcreteStrategy(VectorizeStrategy concreteStrategy) {
            INSTANCE = concreteStrategy;

        public VectorImageGridIntersections processImage(MarvinImage img) {
            return INSTANCE.processImage(img);

     * Should perform edge Detection in order to have lines, that can be vectorized.
     * @param img An Image suitable for edge detection.
     * @return the VectorImageGridIntersections representing img's vectors 
     * intersections with the grids.
    VectorImageGridIntersections processImage(MarvinImage img);

The fact that the enum implements the strategy is convenient to allow the enum class to act as proxy for its enclosed Instance. which also implements the interface.

it's a sort of strategyEnumProxy :P the clent code looks like this:


If it didn't implement the interface it'd had been:


Anybody knows any knowledge base open source?

In addition to MediaWiki that was mentioned by Kenny, you might also look at MoinMoin.

Choosing between MediaWiki and MoinMoin can be a bit tough. Here are some points to consider:



  • Made for wikipedia, thus is very mature and scalable.
  • Fairly easy to set up.


  • Made soley for wikipedia. Thus it can be a bit of a pain to customize how you like it.



  • Very mature software.
  • Huge amount of plugins and third party modules available.


  • Can be a pain to install.

There are a huge amount of other wikis available, but those are the main two I would consider.

Android - set TextView TextStyle programmatically?

So many way to achieve this task some are below:-


String text_view_str = "<b>Bolded text</b>, <i>italic text</i>, even <u>underlined</u>!";
TextView tv = (TextView)findViewById(;


tv.setTypeface(null, Typeface.BOLD);
tv.setTypeface(null, Typeface.ITALIC);
tv.setTypeface(null, Typeface.BOLD_ITALIC);
tv.setTypeface(null, Typeface.NORMAL);


SpannableString spannablecontent=new SpannableString(o.content.toString());
spannablecontent.setSpan(new StyleSpan(, 
                         0,spannablecontent.length(), 0);
// set Text here


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

    <style name="boldText">
        <item name="android:textStyle">bold|italic</item>
        <item name="android:textColor">#FFFFFF</item>

    <style name="normalText">
        <item name="android:textStyle">normal</item>
        <item name="android:textColor">#C0C0C0</item>



or if u want through xml


How to force deletion of a python object?

In general, to make sure something happens no matter what, you use

from exceptions import NameError

    f = open(x)
except ErrorType as e:
    pass # handle the error
    except NameError: pass

finally blocks will be run whether or not there is an error in the try block, and whether or not there is an error in any error handling that takes place in except blocks. If you don't handle an exception that is raised, it will still be raised after the finally block is excecuted.

The general way to make sure a file is closed is to use a "context manager".

with open(x) as f:
    # do stuff

This will automatically close f.

For your question #2, bar gets closed on immediately when it's reference count reaches zero, so on del foo if there are no other references.

Objects are NOT created by __init__, they're created by __new__.

When you do foo = Foo() two things are actually happening, first a new object is being created, __new__, then it is being initialized, __init__. So there is no way you could possibly call del foo before both those steps have taken place. However, if there is an error in __init__, __del__ will still be called because the object was actually already created in __new__.

Edit: Corrected when deletion happens if a reference count decreases to zero.

How can I prevent the textarea from stretching beyond his parent DIV element? (google-chrome issue only)

Textarea resize control is available via the CSS3 resize property:

textarea { resize: both; } /* none|horizontal|vertical|both */
textarea.resize-vertical{ resize: vertical; }
textarea.resize-none { resize: none; }

Allowable values self-explanatory: none (disables textarea resizing), both, vertical and horizontal.

Notice that in Chrome, Firefox and Safari the default is both.

If you want to constrain the width and height of the textarea element, that's not a problem: these browsers also respect max-height, max-width, min-height, and min-width CSS properties to provide resizing within certain proportions.

Code example:

#textarea-wrapper {_x000D_
  padding: 10px;_x000D_
  background-color: #f4f4f4;_x000D_
  width: 300px;_x000D_
#textarea-wrapper textarea {_x000D_
  width: 290px;_x000D_
#textarea-wrapper textarea.vertical { _x000D_
  resize: vertical;_x000D_
<div id="textarea-wrapper">_x000D_
  <label for="resize-default">Textarea (default):</label>_x000D_
  <textarea name="resize-default" id="resize-default"></textarea>_x000D_
  <label for="resize-vertical">Textarea (vertical):</label>_x000D_
  <textarea name="resize-vertical" id="resize-vertical" class="vertical">Notice this allows only vertical resize!</textarea>_x000D_

How can I tell which button was clicked in a PHP form submit?

Are you asking in php or javascript.

If it is in php, give the name of that and use the post or get method, after that you can use the option of isset or that particular button name is checked to that value.

If it is in js, use getElementById for that

How do I pass parameters into a PHP script through a webpage?

$argv[0]; // the script name
$argv[1]; // the first parameter
$argv[2]; // the second parameter

If you want to all the script to run regardless of where you call it from (command line or from the browser) you'll want something like the following:

if ($_GET) {
    $argument1 = $_GET['argument1'];
    $argument2 = $_GET['argument2'];
} else {
    $argument1 = $argv[1];
    $argument2 = $argv[2];

To call from command line chmod 755 /var/www/webroot/index.php and use

/usr/bin/php /var/www/webroot/index.php arg1 arg2

To call from the browser, use

Efficiently test if a port is open on Linux?

they're listed in /proc/net/tcp.

it's the second column, after the ":", in hex:

> cat /proc/net/tcp
  sl  local_address rem_address   st tx_queue rx_queue tr tm->when retrnsmt   uid  timeout inode                                                     
   0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000     0        0 10863 1 ffff88020c785400 99 0 0 10 -1                     
   1: 0100007F:0277 00000000:0000 0A 00000000:00000000 00:00000000 00000000     0        0 7983 1 ffff88020eb7b3c0 99 0 0 10 -1                      
   2: 0500010A:948F 0900010A:2328 01 00000000:00000000 02:00000576 00000000  1000        0 10562454 2 ffff88010040f7c0 22 3 30 5 3                   
   3: 0500010A:E077 5F2F7D4A:0050 01 00000000:00000000 02:00000176 00000000  1000        0 10701021 2 ffff880100474080 41 3 22 10 -1                 
   4: 0500010A:8773 16EC97D1:0050 01 00000000:00000000 02:00000BDC 00000000  1000        0 10700849 2 ffff880104335440 57 3 18 10 -1                 
   5: 0500010A:8772 16EC97D1:0050 01 00000000:00000000 02:00000BF5 00000000  1000        0 10698952 2 ffff88010040e440 46 3 0 10 -1                  
   6: 0500010A:DD2C 0900010A:0016 01 00000000:00000000 02:0006E764 00000000  1000        0 9562907 2 ffff880104334740 22 3 30 5 4                    
   7: 0500010A:AAA4 6A717D4A:0050 08 00000000:00000001 02:00000929 00000000  1000        0 10696677 2 ffff880106cc77c0 45 3 0 10 -1  

so i guess one of those :50 in the third column must be stackoverflow :o)

look in man 5 proc for more details. and picking that apart with sed etc is left as an exercise for the gentle reader...

How can I redirect a php page to another php page?

While all of the other answers work, they all have one big problem: it is up to the browser to decide what to do if they encounter a Location header. Usually browser stop processing the request and redirect to the URI indicated with the Location header. But a malicious user could just ignore the Location header and continue its request. Furthermore there may be other things that cause the php interpreter to continue evaluating the script past the Location header, which is not what you intended.

Image this:

if (!logged_id()) {


What you want and expected is that not logged in users are redirected to the login page, so that only logged in users can delete_everything. But if the script gets executed past the Location header still everything gets deleted. Thus, it is import to ALWAYS put an exit after a Location header, like this:

if (!logged_id()) {
    exit; // <- don't forget this!


So, to answer your question: to redirect from a php page to another page (not just php, you can redirect to any page this way), use this:


exit; // <- don't forget this!


Small note: the HTTP standard says that you must provide absolute URLs in the Location header (http://... like in my example above) even if you just want to redirect to another file on the same domain. But in practice relative URLs (Location:some_page.php) work in all browsers, though not being standard compliant.

How to change CSS using jQuery?

$(function(){ _x000D_
"border":"1px solid #EFEFEF",_x000D_
"margin":"0 auto",_x000D_
<script src=""></script>_x000D_
<div class="bordered">_x000D_
<p id="myParagraph">This is some paragraph text</p>_x000D_

How to programmatically set style attribute in a view

Depending on what style attributes you'd like to change you may be able to use the Paris library:

Button view = (Button) LayoutInflater.from(this).inflate(R.layout.section_button, null);;

Many attributes like background, padding, textSize, textColor, etc. are supported.

Disclaimer: I authored the library.

Why are unnamed namespaces used and what are their benefits?

An anonymous namespace makes the enclosed variables, functions, classes, etc. available only inside that file. In your example it's a way to avoid global variables. There is no runtime or compile time performance difference.

There isn't so much an advantage or disadvantage aside from "do I want this variable, function, class, etc. to be public or private?"

Angularjs -> ng-click and ng-show to show a div

Just remove css from your js fiddle,use the myvaue === true.

<div ng-show="myvalue == true" class="ng-cloak">Here I am</div>

"The semaphore timeout period has expired" error for USB connection

Too many big files all in one go. Windows barfs. Essentially the copying took too long because you asked too much of the computer and the file locking was locked too long and set a flag off, the flag is a semaphore error.

The computer stuffed itself and choked on it. I saw the RAM memory here get progressively filled with a Cache in RAM. Then when filled the subsystem ground to a halt with a semaphore error.

I have a workaround; copy or transfer fewer files not one humongous block. Break it down into sets of blocks and send across the files one at a time, maybe a few at a time, but not never the lot.


How to check if an appSettings key exists?

MSDN: Configuration Manager.AppSettings

if (ConfigurationManager.AppSettings[name] != null)
// Now do your magic..


string s = ConfigurationManager.AppSettings["myKey"];
if (!String.IsNullOrEmpty(s))
    // Key exists
    // Key doesn't exist

How to define Typescript Map of key value pair. where key is a number and value is an array of objects

First thing, define a type or interface for your object, it will make things much more readable:

type Product = { productId: number; price: number; discount: number };

You used a tuple of size one instead of array, it should look like this:

let myarray: Product[];
let priceListMap : Map<number, Product[]> = new Map<number, Product[]>();

So now this works fine:

myarray.push({productId : 1 , price : 100 , discount : 10});
myarray.push({productId : 2 , price : 200 , discount : 20});
myarray.push({productId : 3 , price : 300 , discount : 30});
priceListMap.set(1 , this.myarray);
myarray = null;

(code in playground)

Android Studio Rendering Problems : The following classes could not be found

You have to do two things:

  • be sure to have imported right appcompat-v7 library in your project structure -> dependencies
  • change the theme in the preview window to not an AppCompat theme. Try with Holo.light or Holo.dark for example.

How to extract text from a string using sed?

Try this instead:

echo "This is 02G05 a test string 20-Jul-2012" | sed 's/.* \([0-9]\+G[0-9]\+\) .*/\1/'

But note, if there is two pattern on one line, it will prints the 2nd.

Retrieving a random item from ArrayList

System.out.println("Managers choice this week" + anyItem + "our recommendation to you");

You havent the variable anyItem initialized or even declared.

This code: + anyItem +

means get value of toString method of Object anyItem

The second thing why this wont work. You have System.out.print after return statement. Program could never reach tha line.

You probably want something like:

public Item anyItem() {
    int index = randomGenerator.nextInt(catalogue.size());
    System.out.println("Managers choice this week" + catalogue.get(index) + "our recommendation to you");
    return catalogue.get(index);


btw: in Java its convetion to place the curly parenthesis on the same line as the declaration of the function.

React Hooks useState() with Object

function App() {

  const [todos, setTodos] = useState([
    { id: 1, title: "Selectus aut autem", completed: false },
    { id: 2, title: "Luis ut nam facilis et officia qui", completed: false },
    { id: 3, title: "Fugiat veniam minus", completed: false },
    { id: 4, title: "Aet porro tempora", completed: true },
    { id: 5, title: "Laboriosam mollitia et enim quasi", completed: false }

  const changeInput = (e) => { => === parseInt( && (items.completed =;
 setTodos([...todos], todos);}
  return (
    <div className="container">
      { => {
        return (
          <div key={}>
<input type="checkbox" 
checked={items.completed} />&nbsp; {items.title}</label>

A reference to the dll could not be added

I have the same problem with importing WinSCard.dll in my project. I deal with that importing directly from dll like this:

public static extern int SCardEstablishContext(int dwScope, int pvReserved1, int pvReserved2, ref int phContext);

public static extern int SCardReleaseContext(int phContext);

You could add this to separate project and then add a reference from your main project.

rotate image with css

Give the parent a style of overflow: hidden. If it is overlapping sibling elements, you will have to put it inside of a container with a fixed height/width and give that a style of overflow: hidden.

CSS to keep element at "fixed" position on screen

You may be looking for position: fixed.

Works everywhere except IE6 and many mobile devices.

How to get a Char from an ASCII Character Code in c#

Two options:

char c1 = '\u0001';
char c1 = (char) 1;

How to do multiple arguments to map function where one remains the same in python?

Map can contain multiple arguments, the standard way is

map(add, a, b)

In your question, it should be

map(add, a, [2]*len(a))

Android Studio: Where is the Compiler Error Output Window?

This answer is outdated. For Android 3.1 Studio go to this answer

One thing you can do is deactivate the external build. To do so click on "compiler settings icon" in the "Messages Make" panel that appears when you have an error. You can also open the compiler settings by going to File -> Settings -> Compiler. (Thanx to @maxgalbu for this tip).

enter image description here

Uncheck "Use External build"

enter image description here

And you will see the errors in the console

EDIT: After returning to "internal build" again you may get some errors, you can solve them this way: Android Studio: disabling "External build" to display error output create duplicate class errors

Using Java to pull data from a webpage?

Here's my solution using URL and try with resources phrase to catch the exceptions.

 * Created by mona on 5/27/16.
public class ReadFromWeb {
    public static void readFromWeb(String webURL) throws IOException {
        URL url = new URL(webURL);
        InputStream is =  url.openStream();
        try( BufferedReader br = new BufferedReader(new InputStreamReader(is))) {
            String line;
            while ((line = br.readLine()) != null) {
        catch (MalformedURLException e) {
            throw new MalformedURLException("URL is malformed!!");
        catch (IOException e) {
            throw new IOException();

    public static void main(String[] args) throws IOException {
        String url = "";


You could additionally save it to file based on your needs or parse it using XML or HTML libraries.

Java Compare Two List's object values?

I think you can sort both lists and convert to List if some of them was a HashSet colleciton.

java.utils.Collections package lets you do it.

List<Category> categoriesList = new ArrayList<>();
Set<Category> setList = new HashSet<>();
List<Category> fileCategories = new ArrayList<>(setList);

if(categoriesList.size() == fileCategories.size() && categoriesList.containsAll(fileCategories)) {
    //Do something

Converting a POSTMAN request to Curl

Starting from Postman 8 you need to visit here

enter image description here

How do I detect what .NET Framework versions and service packs are installed?

There is an official Microsoft answer to this question at the following knowledge base article:

Article ID: 318785 - Last Review: November 7, 2008 - Revision: 20.1 How to determine which versions of the .NET Framework are installed and whether service packs have been applied

Unfortunately, it doesn't appear to work, because the mscorlib.dll version in the 2.0 directory has a 2.0 version, and there is no mscorlib.dll version in either the 3.0 or 3.5 directories even though 3.5 SP1 is installed ... why would the official Microsoft answer be so misinformed?

How to show SVG file on React Native?

After trying many ways and libraries I decided to create a new font (with Glyphs or this tutorial) and add my SVG files to it, then use "Text" component with my custom font.

Hope this helps anyone that has the same problem with SVG in react-native.

React fetch data in server before render

What you're looking for is componentWillMount.

From the documentation:

Invoked once, both on the client and server, immediately before the initial rendering occurs. If you call setState within this method, render() will see the updated state and will be executed only once despite the state change.

So you would do something like this:

componentWillMount : function () {
    var data = this.getData();
    this.setState({data : data});

This way, render() will only be called once, and you'll have the data you're looking for in the initial render.

Hashmap holding different data types as values for instance Integer, String and Object

If you don't have Your own Data Class, then you can design your map as follows

Map<Integer, Object> map=new HashMap<Integer, Object>();

Here don't forget to use "instanceof" operator while retrieving the values from MAP.

If you have your own Data class then then you can design your map as follows

Map<Integer, YourClassName> map=new HashMap<Integer, YourClassName>();

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class HashMapTest {
public static void main(String[] args) {
    Map<Integer,Demo> map=new HashMap<Integer, Demo>();
    Demo d1= new Demo(1,"hi",new Date(),1,1);
    Demo d2= new Demo(2,"this",new Date(),2,1);
    Demo d3= new Demo(3,"is",new Date(),3,1);
    Demo d4= new Demo(4,"mytest",new Date(),4,1);
    //adding values to map
    map.put(d1.getKey(), d1);
    map.put(d2.getKey(), d2);
    map.put(d3.getKey(), d3);
    map.put(d4.getKey(), d4);
    //retrieving values from map
    Set<Integer> keySet= map.keySet();
    for(int i:keySet){
    //searching key on map
    //searching value on map

class Demo{
    private int key;
    private String message;
    private Date time;
    private int count;
    private int version;

    public Demo(int key,String message, Date time, int count, int version){
        this.message = message;
        this.time = time;
        this.count = count;
        this.version = version;
    public String getMessage() {
        return message;
    public Date getTime() {
        return time;
    public int getCount() {
        return count;
    public int getVersion() {
        return version;
    public int getKey() {
        return key;
    public String toString() {
        return "Demo [message=" + message + ", time=" + time
                + ", count=" + count + ", version=" + version + "]";


ASP.NET email validator regex

Apart from the client side validation with a Validator, I also recommend doing server side validation as well.

bool isValidEmail(string input)
        var email = new System.Net.Mail.MailAddress(input);
        return true;
        return false;

Accessing an SQLite Database in Swift

Yet another SQLite wrapper for Swift 2 and Swift 3:


  • An API that will look familiar to users of ccgus/fmdb

  • A low-level SQLite API that leverages the Swift standard library

  • A pretty Swift query interface for SQL-allergic developers

  • Support for the SQLite WAL mode, and concurrent database access for extra performance

  • A Record class that wraps result sets, eats your custom SQL queries for breakfast, and provides basic CRUD operations

  • Swift type freedom: pick the right Swift type that fits your data. Use Int64 when needed, or stick with the convenient Int. Store and read NSDate or NSDateComponents. Declare Swift enums for discrete data types. Define your own database-convertible types.

  • Database Migrations

  • Speed:

Using parameters in batch files at Windows command line

As others have already said, parameters passed through the command line can be accessed in batch files with the notation %1 to %9. There are also two other tokens that you can use:

  • %0 is the executable (batch file) name as specified in the command line.
  • %* is all parameters specified in the command line -- this is very useful if you want to forward the parameters to another program.

There are also lots of important techniques to be aware of in addition to simply how to access the parameters.

Checking if a parameter was passed

This is done with constructs like IF "%~1"=="", which is true if and only if no arguments were passed at all. Note the tilde character which causes any surrounding quotes to be removed from the value of %1; without a tilde you will get unexpected results if that value includes double quotes, including the possibility of syntax errors.

Handling more than 9 arguments (or just making life easier)

If you need to access more than 9 arguments you have to use the command SHIFT. This command shifts the values of all arguments one place, so that %0 takes the value of %1, %1 takes the value of %2, etc. %9 takes the value of the tenth argument (if one is present), which was not available through any variable before calling SHIFT (enter command SHIFT /? for more options).

SHIFT is also useful when you want to easily process parameters without requiring that they are presented in a specific order. For example, a script may recognize the flags -a and -b in any order. A good way to parse the command line in such cases is

IF "%~1"=="" GOTO endparse
IF "%~1"=="-a" REM do something
IF "%~1"=="-b" REM do something else
GOTO parse
REM ready for action!

This scheme allows you to parse pretty complex command lines without going insane.

Substitution of batch parameters

For parameters that represent file names the shell provides lots of functionality related to working with files that is not accessible in any other way. This functionality is accessed with constructs that begin with %~.

For example, to get the size of the file passed in as an argument use

ECHO %~z1

To get the path of the directory where the batch file was launched from (very useful!) you can use

ECHO %~dp0

You can view the full range of these capabilities by typing CALL /? in the command prompt.

Adjusting HttpWebRequest Connection Timeout in C#

Sorry for tacking on to an old thread, but I think something that was said above may be incorrect/misleading.

From what I can tell .Timeout is NOT the connection time, it is the TOTAL time allowed for the entire life of the HttpWebRequest and response. Proof:

I Set:


The connect and post time for the HttpWebRequest took 26ms

but the subsequent call HttpWebRequest.GetResponse() timed out in 4974ms thus proving that the 5000ms was the time limit for the whole send request/get response set of calls.

I didn't verify if the DNS name resolution was measured as part of the time as this is irrelevant to me since none of this works the way I really need it to work--my intention was to time out quicker when connecting to systems that weren't accepting connections as shown by them failing during the connect phase of the request.

For example: I'm willing to wait 30 seconds on a connection request that has a chance of returning a result, but I only want to burn 10 seconds waiting to send a request to a host that is misbehaving.

Retrieve all values from HashMap keys in an ArrayList Java

List constructor accepts any data structure that implements Collection interface to be used to build a list.

To get all the keys from a hash map to a list:

Map<String, Integer> map = new HashMap<String, Integer>();
List<String> keys = new ArrayList<>(map.keySet());

To get all the values from a hash map to a list:

Map<String, Integer> map = new HashMap<String, Integer>();
List<Integer> values = new ArrayList<>(map.values());

Leave menu bar fixed on top when scrolled

This is jquery code which is used to fixed the div when it touch a top of browser hope it will help a lot.

<script type='text/javascript' src=''></script>
<script type='text/javascript'>//<![CDATA[ 
$(function() {
    $.fn.scrollBottom = function() {
        return $(document).height() - this.scrollTop() - this.height();

    var $el = $('#sidebar>div');
    var $window = $(window);
    var top = $el.parent().position().top;

    $window.bind("scroll resize", function() {
        var gap = $window.height() - $el.height() - 10;
        var visibleFoot = 172 - $window.scrollBottom();
        var scrollTop = $window.scrollTop()

        if (scrollTop < top + 10) {
                top: (top - scrollTop) + "px",
                bottom: "auto"
        } else if (visibleFoot > gap) {
                top: "auto",
                bottom: visibleFoot + "px"
        } else {
                top: 0,
                bottom: "auto"


Vertically align an image inside a div with responsive height

Try this one

          vertical-align: middle;

File upload progress bar with jQuery

I've done this with jQuery only:

  xhr: function() {
    var xhr = new window.XMLHttpRequest();

    xhr.upload.addEventListener("progress", function(evt) {
      if (evt.lengthComputable) {
        var percentComplete = evt.loaded /;
        percentComplete = parseInt(percentComplete * 100);

        if (percentComplete === 100) {


    }, false);

    return xhr;
  url: posturlfile,
  type: "POST",
  data: JSON.stringify(fileuploaddata),
  contentType: "application/json",
  dataType: "json",
  success: function(result) {

Initializing a dictionary in python with a key value and no corresponding values

you could use a defaultdict. It will let you set dictionary values without worrying if the key already exists. If you access a key that has not been initialized yet it will return a value you specify (in the below example it will return None)

from collections import defaultdict
your_dict = defaultdict(lambda : None)

How do we update URL or query strings using javascript/jQuery without reloading the page?

Yes and no. All the common web browsers has a security measure to prevent that. The goal is to prevent people from creating replicas of websites, change the URL to make it look correct, and then be able to trick people and get their info.

However, some HTML5 compatible web browsers has implemented an History API that can be used for something similar to what you want:

if (history.pushState) {
    var newurl = window.location.protocol + "//" + + window.location.pathname + '?myNewUrlQuery=1';

I tested, and it worked fine. It does not reload the page, but it only allows you to change the URL query. You would not be able to change the protocol or the host values.

For more information:

java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener

For me the fix was to right click on my webapp module > Maven > Update Project

Find directory name with wildcard or similar to "like"

find supports wildcard matches, just add a *:

find / -type d -name "ora10*"

JavaScript private methods

var TestClass = function( ) {

    var privateProperty = 42;

    function privateMethod( ) {
        alert( "privateMethod, " + privateProperty );

    this.public = {
        constructor: TestClass,

        publicProperty: 88,
        publicMethod: function( ) {
            alert( "publicMethod" );
            privateMethod( );
TestClass.prototype = new TestClass( ).public;

var myTestClass = new TestClass( );

alert( myTestClass.publicProperty );
myTestClass.publicMethod( );

alert( myTestClass.privateMethod || "no privateMethod" );

Similar to georgebrock but a little less verbose (IMHO) Any problems with doing it this way? (I haven't seen it anywhere)

edit: I realised this is kinda useless since every independent instantiation has its own copy of the public methods, thus undermining the use of the prototype.

How to convert ISO8859-15 to UTF8?

I got the same problem, but i find the answer in this page! it works for me, you can try it.

iconv -f cp936 -t utf-8 

Get year, month or day from numpy datetime64

If you upgrade to numpy 1.7 (where datetime is still labeled as experimental) the following should work.


Are there any HTTP/HTTPS interception tools like Fiddler for mac OS X?

HTTPScoop is awesome for inspecting the web traffic on your Mac. It's been incredibly helpful for me. I didn't think twice about the $15 price tag. There is a 14 day trial.

Deleting all records in a database table

If you are looking for a way to it without SQL you should be able to use delete_all.


or with a criteria

Post.delete_all "person_id = 5 AND (category = 'Something' OR category = 'Else')"

See here for more information.

The records are deleted without loading them first which makes it very fast but will break functionality like counter cache that depends on rails code to be executed upon deletion.

Spring not autowiring in unit tests with JUnit

Add something like this to your root unit test class:

@RunWith( SpringJUnit4ClassRunner.class )

This will use the XML in your default path. If you need to specify a non-default path then you can supply a locations property to the ContextConfiguration annotation.

Adding data attribute to DOM

Using .data() will only add data to the jQuery object for that element. In order to add the information to the element itself you need to access that element using jQuery's .attr or native .setAttribute

$('div').attr('data-info', 1);

In order to access an element with the attribute set, you can simply select based on that attribute as you note in your post ($('div[data-info="1"]')), but when you use .data() you cannot. In order to select based on the .data() setting, you would need to use jQuery's filter function.

jsFiddle Demo

$('div').data('info', 1);_x000D_
   return $(this).data('info') == 1; _x000D_
<script src=""></script>_x000D_

Angular2 *ngIf check object array length in template

You could use *ngIf="teamMembers != 0" to check whether data is present

Listen to changes within a DIV and act accordingly

Though the event DOMSubtreeModified is deprecated, its working as of now, so for any makeshift projects you can use it as following.

$("body").on('DOMSubtreeModified', "#mydiv", function() {

In the long term though, you'll have to use the MutationObserver API.

How to set variables in HIVE scripts

There are multiple options to set variables in Hive.

If you're looking to set Hive variable from inside the Hive shell, you can set it using hivevar. You can set string or integer datatypes. There are no problems with them.

SET hivevar:which_date=20200808;
select ${which_date};

If you're planning to set variables from shell script and want to pass those variables into your Hive script (HQL) file, you can use --hivevar option while calling hive or beeline command.

# shell script will invoke script like this
beeline --hivevar tablename=testtable -f select.hql
-- select.hql file
select * from <dbname>.${tablename};

ng-repeat: access key and value for each object in array of objects

Here is another way, without the need for nesting the repeaters.

From the Angularjs docs:

It is possible to get ngRepeat to iterate over the properties of an object using the following syntax:

<div ng-repeat="(key, value) in steps"> {{key}} : {{value}} </div>

Java, Simplified check if int array contains int

It's because Arrays.asList(array) return List<int[]>. array argument is treated as one value you want to wrap (you get list of arrays of ints), not as vararg.

Note that it does work with object types (not primitives):

public boolean contains(final String[] array, final String key) {
    return Arrays.asList(array).contains(key);

or even:

public <T>  boolean contains(final T[] array, final T key) {
    return Arrays.asList(array).contains(key);

But you cannot have List<int> and autoboxing is not working here.

How do I redirect output to a variable in shell?

Create a function calling it as the command you want to invoke. In this case, I need to use the ruok command.

Then, call the function and assign its result into a variable. In this case, I am assigning the result to the variable health.

function ruok {
  echo ruok | nc *ip* 2181

health=echo ruok *ip*

JavaScript Regular Expression Email Validation

You can also try this expression, I have tested it against many email addresses.

var pattern = /^[A-Za-z0-9._%+-]+@([A-Za-z0-9-]+\.)+([A-Za-z0-9]{2,4}|museum)$/;

Error: vector does not name a type

Also you can add #include<vector> in the header. When two of the above solutions don't work.

Is there a 'foreach' function in Python 3?

Here is the example of the "foreach" construction with simultaneous access to the element indexes in Python:

for idx, val in enumerate([3, 4, 5]):
    print (idx, val)

Confusing error in R: Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : line 1 did not have 42 elements)

read.table wants to return a data.frame, which must have an element in each column. Therefore R expects each row to have the same number of elements and it doesn't fill in empty spaces by default. Try read.table("/PathTo/file.csv" , fill = TRUE ) to fill in the blanks.


read.table( text= "Element1 Element2
Element5 Element6 Element7" , fill = TRUE , header = FALSE )
#        V1       V2       V3
#1 Element1 Element2         
#2 Element5 Element6 Element7

A note on whether or not to set header = FALSE... read.table tries to automatically determine if you have a header row thus:

header is set to TRUE if and only if the first row contains one fewer field than the number of columns

Attach parameter to button.addTarget action in Swift

I appreciate everyone saying use tags, but really you need to extend the UIButton class and simply add the object there..

Tags are a hopeless way round this. Extend the UIButton like this (in Swift 4)

import UIKit
class PassableUIButton: UIButton{
    var params: Dictionary<String, Any>
    override init(frame: CGRect) {
        self.params = [:]
        super.init(frame: frame)

    required init?(coder aDecoder: NSCoder) {
        self.params = [:]
        super.init(coder: aDecoder)

then your call may be call (NOTE THE colon ":" in Selector(("webButtonTouched:")))

let webButton = PassableUIButton(frame: CGRect(x:310, y:40, width:40, height:40))
webButton.setTitle("Visit",for: .normal)
webButton.addTarget(self, action: #selector(YourViewController.webButtonTouched(_:)), for:.touchUpInside)
webButton.params["myvalue"] = "bob"

then finally catch it all here

@IBAction func webButtonTouched(_ sender: PassableUIButton) {
    print(sender.params["myvalue"] ?? "")

You do this one time and use it throughout your project (you can even make the child class have a generic "object" and put whatever you like into the button!). Or use the example above to put an inexhaustible number of key/string params into the button.. Really useful for including things like urls, confirm message methodology etc

As an aside, it's important that the SO community realise this there is an entire generation of bad practice being cut'n'paste round the internet by an alarming number of programmers who don't understand/haven't been taught/missed the point of the concept of object extensions

What is the difference between visibility:hidden and display:none?

display: none removes the element from the page entirely, and the page is built as though the element were not there at all.

Visibility: hidden leaves the space in the document flow even though you can no longer see it.

This may or may not make a big difference depending on what you are doing.

Color text in discord

Discord doesn't allow colored text. Though, currently, you have two options to "mimic" colored text.

Option #1 (Markdown code-blocks)

Discord supports Markdown and uses highlight.js to highlight code-blocks. Some programming languages have specific color outputs from highlight.js and can be used to mimic colored output.

To use code-blocks, send a normal message in this format (Which follows Markdown's standard format).


Languages that currently reproduce nice colors: prolog (red/orange), css (yellow).

Option #2 (Embeds)

Discord now supports Embeds and Webhooks, which can be used to display colored blocks, they also support markdown. For documentation on how to use Embeds, please read your lib's documentation.

(Embed Cheat-sheet)
Embed Cheat-sheet

I can't find my git.exe file in my Github folder

I found my git.exe here

C:\Program Files\Git\bin\git.exe

while installing git, it asks for the location. copy it and use it.

Where can I find the API KEY for Firebase Cloud Messaging?

Enter here:

https: //

(replace your-project with your project-name) and click in "Add firebase in your web app"(the red circle icon) this action show you a dialog with:

  • apiKey
  • authDomain
  • databaseURL
  • storageBucket
  • messagingSenderId

How to get a random number in Ruby

Well, I figured it out. Apparently there is a builtin (?) function called rand:

rand(n + 1)

If someone answers with a more detailed answer, I'll mark that as the correct answer.

TypeScript and field initializers


Since writing this answer, better ways have come up. Please see the other answers below that have more votes and a better answer. I cannot remove this answer since it's marked as accepted.

Old answer

There is an issue on the TypeScript codeplex that describes this: Support for object initializers.

As stated, you can already do this by using interfaces in TypeScript instead of classes:

interface Name {
    first: string;
    last: string;
class Person {
    name: Name;
    age: number;

var bob: Person = {
    name: {
        first: "Bob",
        last: "Smith",
    age: 35,

Populating spinner directly in the layout xml

In regards to the first comment: If you do this you will get an error(in Android Studio). This is in regards to it being out of the Android namespace. If you don't know how to fix this error, check the example out below. Hope this helps!

Example -Before :

<string-array name="roomSize">

Example - After:

<string-array android:name="roomSize">

What is the significance of 1/1/1753 in SQL Server?

The decision to use 1st January 1753 (1753-01-01) as the minimum date value for a datetime in SQL Server goes back to its Sybase origins.

The significance of the date itself though can be attributed to this man.

Philip Stanhope, 4th Earl of Chesterfield

Philip Stanhope, 4th Earl of Chesterfield. Who steered the Calendar (New Style) Act 1750 through the British Parliament. This legislated for the adoption of the Gregorian calendar for Britain and its then colonies.

There were some missing days (internet archive link) in the British calendar in 1752 when the adjustment was finally made from the Julian calendar. September 3, 1752 to September 13, 1752 were lost.

Kalen Delaney explained the choice this way

So, with 12 days lost, how can you compute dates? For example, how can you compute the number of days between October 12, 1492, and July 4, 1776? Do you include those missing 12 days? To avoid having to solve this problem, the original Sybase SQL Server developers decided not to allow dates before 1753. You can store earlier dates by using character fields, but you can't use any datetime functions with the earlier dates that you store in character fields.

The choice of 1753 does seem somewhat anglocentric however as many catholic countries in Europe had been using the calendar for 170 years before the British implementation (originally delayed due to opposition by the church). Conversely many countries did not reform their calendars until much later, 1918 in Russia. Indeed the October Revolution of 1917 started on 7 November under the Gregorian calendar.

Both datetime and the new datetime2 datatype mentioned in Joe's answer do not attempt to account for these local differences and simply use the Gregorian Calendar.

So with the greater range of datetime2



Sep  8 1752 12:00AM

One final point with the datetime2 data type is that it uses the proleptic Gregorian calendar projected backwards to well before it was actually invented so is of limited use in dealing with historic dates.

This contrasts with other Software implementations such as the Java Gregorian Calendar class which defaults to following the Julian Calendar for dates until October 4, 1582 then jumping to October 15, 1582 in the new Gregorian calendar. It correctly handles the Julian model of leap year before that date and the Gregorian model after that date. The cutover date may be changed by the caller by calling setGregorianChange().

A fairly entertaining article discussing some more peculiarities with the adoption of the calendar can be found here.

How to get the size of a range in Excel

The overall dimensions of a range are in its Width and Height properties.

Dim r As Range
Set r = ActiveSheet.Range("A4:H12")

Debug.Print r.Width
Debug.Print r.Height

Vertically center text in a 100% height div?

I disagree, here's a JS free solution, which works:

<html style="height: 100%;">
    <body style="vertical-align: middle; margin: 0px; height: 100%;">
        <div style="height: 100%; width: 100%; display: table; background-color: #ccc;">
            <div style="display: table-cell; width: 100%; vertical-align: middle;">
                <div style="height: 300px; width: 600px; background-color: wheat; margin-left: auto; margin-right: auto;">A</div>

How to get text of an element in Selenium WebDriver, without including child element text?

Unfortunately, Selenium was only built to work with Elements, not Text nodes.

If you try to use a function like get_element_by_xpath to target the text nodes, Selenium will throw an InvalidSelectorException.

One workaround is to grab the relevant HTML with Selenium and then use an HTML parsing library like BeautifulSoup that can handle text nodes more elegantly.

import bs4
from bs4 import BeautifulSoup

inner_html = driver.find_elements_by_css_selector('#a')[0].get_attribute("innerHTML")
inner_soup = BeautifulSoup(inner_html, 'html.parser')

outer_html = driver.find_elements_by_css_selector('#a')[0].get_attribute("outerHTML")
outer_soup = BeautifulSoup(outer_html, 'html.parser')

From there, there are several ways to search for the Text content. You'll have to experiment to see what works best for your use case.

Here's a simple one-liner that may be sufficient:


If that doesn't work, then you can loop through the element's child nodes with .contents() and check their object type.

BeautifulSoup has four types of elements, and the one that you'll be interested in is the NavigableString type, which is produced by Text nodes. By contrast, Elements will have a type of Tag.

contents = inner_soup.contents

for bs4_object in contents:

    if (type(bs4_object) == bs4.Tag):
        print("This object is an Element.")

    elif (type(bs4_object) == bs4.NavigableString):
        print("This object is a Text node.")

Note that BeautifulSoup doesn't support Xpath expressions. If you need those, then you can use some of the workarounds in this thread.

Overriding a JavaScript function while referencing the original

Passing arbitrary arguments:

a = override(a, function(original_a) {
    if (condition) { new_code(); original_a.apply(this, arguments) ; }
    else { original_a.apply(this, arguments); other_new_code(); }

How to generate the whole database script in MySQL Workbench?

None of these worked for me. I'm using Mac OS 10.10.5 and Workbench 6.3. What worked for me is Database->Migration Wizard... Flow the steps very carefully

Pandas left outer join multiple dataframes on multiple columns

Merge them in two steps, df1 and df2 first, and then the result of that to df3.

In [33]: s1 = pd.merge(df1, df2, how='left', on=['Year', 'Week', 'Colour'])

I dropped year from df3 since you don't need it for the last join.

In [39]: df = pd.merge(s1, df3[['Week', 'Colour', 'Val3']],
                       how='left', on=['Week', 'Colour'])

In [40]: df
   Year Week Colour  Val1  Val2 Val3
0  2014    A    Red    50   NaN  NaN
1  2014    B    Red    60   NaN   60
2  2014    B  Black    70   100   10
3  2014    C    Red    10    20  NaN
4  2014    D  Green    20   NaN   20

[5 rows x 6 columns]

How to define global variable in Google Apps Script

    var userProperties = PropertiesService.getUserProperties();

function globalSetting(){
  //creating an array
  userProperties.setProperty('gemployeeName',"Rajendra Barge");
  userProperties.setProperty('gemployeeEmail'," [email protected]");

var userProperties = PropertiesService.getUserProperties();
function showUserForm(){

  var templete = HtmlService.createTemplateFromFile("userForm");
  var html = templete.evaluate();
  html.setTitle("Customer Data");


function appendData(data){
  var ws = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Data");
                Utilities.formatDate(new Date(), "GMT+05:30", "dd-MM-yyyy HH:mm:ss")

function errorMessage(){

Browser.msgBox("! All fields are mandetory");


How do I view the full content of a text or varchar(MAX) column in SQL Server 2008 Management Studio?

Starting from SSMS 18.2, you can now view up to 2 million characters in the grid results. Source

Allow more data to be displayed (Result to Text) and stored in cells (Result to Grid). SSMS now allows up to 2M characters for both.

I verified this with the code below.

DECLARE @S varchar(max) = 'A'

SET @S =  REPLICATE(@S,2000000) + 'B' 

SELECT @S as a

"Unable to find remote helper for 'https'" during git clone

Just in case someone encounters this on a QNAP system or any other system with OPKG as package manager:

You need to install git-http along with git. Like:

opkg install git-http

Forwarding port 80 to 8080 using NGINX

This worked for me:

server {
  listen  80; 

  location / { 
    proxy_pass                ;
    proxy_set_header Host               $host;
    proxy_set_header X-Real-IP          $remote_addr;  
    proxy_set_header X-Forwarded-For    $proxy_add_x_forwarded_for;

If it does not work for you look at the logs at sudo tail -f /var/log/nginx/error.log

Add an incremental number in a field in INSERT INTO SELECT query in SQL Server

You can use the row_number() function for this.

INSERT INTO PM_Ingrediants_Arrangements_Temp(AdminID, ArrangementID, IngrediantID, Sequence)
    SELECT @AdminID, @ArrangementID, PM_Ingrediants.ID,
            row_number() over (order by (select NULL))
    FROM PM_Ingrediants 
    WHERE PM_Ingrediants.ID IN (SELECT ID FROM GetIDsTableFromIDsList(@IngrediantsIDs)

If you want to start with the maximum already in the table then do:

INSERT INTO PM_Ingrediants_Arrangements_Temp(AdminID, ArrangementID, IngrediantID, Sequence)
    SELECT @AdminID, @ArrangementID, PM_Ingrediants.ID,
           coalesce(const.maxs, 0) + row_number() over (order by (select NULL))
    FROM PM_Ingrediants cross join
         (select max(sequence) as maxs from PM_Ingrediants_Arrangement_Temp) const
    WHERE PM_Ingrediants.ID IN (SELECT ID FROM GetIDsTableFromIDsList(@IngrediantsIDs)

Finally, you can just make the sequence column an auto-incrementing identity column. This saves the need to increment it each time:

create table PM_Ingrediants_Arrangement_Temp ( . . .
    sequence int identity(1, 1) -- and might consider making this a primary key too
    . . .

What's a good way to extend Error in JavaScript?

My 2 cents:

Why another answer?

a) Because accessing the Error.stack property (as in some answers) have a large performance penalty.

b) Because it is only one line.

c) Because the solution at does not seems to preserve stack info.

//MyError class constructor
function MyError(msg){
    this.__proto__.__proto__ = Error.apply(null, arguments);

usage example

What does it do?

this.__proto__.__proto__ is MyError.prototype.__proto__, so it is setting the __proto__ FOR ALL INSTANCES of MyError to a specific newly created Error. It keeps MyError class properties and methods and also puts the new Error properties (including .stack) in the __proto__ chain.

Obvious problem:

You can not have more than one instance of MyError with useful stack info.

Do not use this solution if you do not fully understand what this.__proto__.__proto__= does.

Insert multiple rows into single column

If your DBMS supports the notation, you need a separate set of parentheses for each row:

INSERT INTO Data(Col1) VALUES ('Hello'), ('World');

The cross-referenced question shows examples for inserting into two columns.

Alternatively, every SQL DBMS supports the notation using separate statements, one for each row to be inserted:

INSERT INTO Data (Col1) VALUES ('Hello');
INSERT INTO Data (Col1) VALUES ('World');

What is the difference between & vs @ and = in angularJS

@: one-way binding

=: two-way binding

&: function binding

Possible reasons for timeout when trying to access EC2 instance

I had the same problem, and the solution was allowing access from anywhere to the list of inbound rules in the active security group. In the inbound dialog, enter 22 in the port range, anywhere in the source field, and select 'ssh' in the dropdown.

P.S : This might not be the recommended solution as it means this instance can be ssh'ed from any machine, but I could not get it to work with my local IP.

Is it still valid to use IE=edge,chrome=1?

It's still valid to use IE=edge,chrome=1.

But, since the chrome frame project has been wound down the chrome=1 part is redundant for browsers that don't already have the chrome frame plug in installed.

I use the following for correctness nowadays

<meta http-equiv="X-UA-Compatible" content="IE=edge" />

How do I filter ForeignKey choices in a Django ModelForm?

If you haven't created the form and want to change the queryset you can do:

formmodel.base_fields['myfield'].queryset = MyModel.objects.filter(...)

This is pretty useful when you are using generic views!

How to set default values for Angular 2 component properties?

That is interesting subject. You can play around with two lifecycle hooks to figure out how it works: ngOnChanges and ngOnInit.

Basically when you set default value to Input that's mean it will be used only in case there will be no value coming on that component. And the interesting part it will be changed before component will be initialized.

Let's say we have such components with two lifecycle hooks and one property coming from input.

  selector: 'cmp',
export class Login implements OnChanges, OnInit {
  @Input() property: string = 'default';

  ngOnChanges(changes) {

  ngOnInit() {


Situation 1

Component included in html without defined property value

As result we will see in console: Init default

That's mean onChange was not triggered. Init was triggered and property value is default as expected.

Situation 2

Component included in html with setted property <cmp [property]="'new value'"></cmp>

As result we will see in console:

Changed new value Object {}

Init new value

And this one is interesting. Firstly was triggered onChange hook, which setted property to new value, and previous value was empty object! And only after that onInit hook was triggered with new value of property.

Undefined reference to pow( ) in C, despite including math.h

You need to link with the math library:

gcc -o sphere sphere.c -lm

The error you are seeing: error: ld returned 1 exit status is from the linker ld (part of gcc that combines the object files) because it is unable to find where the function pow is defined.

Including math.h brings in the declaration of the various functions and not their definition. The def is present in the math library libm.a. You need to link your program with this library so that the calls to functions like pow() are resolved.

Row names & column names in R

Just to expand a little on Dirk's example:

It helps to think of a data frame as a list with equal length vectors. That's probably why names works with a data frame but not a matrix.

The other useful function is dimnames which returns the names for every dimension. You will notice that the rownames function actually just returns the first element from dimnames.

Regarding rownames and row.names: I can't tell the difference, although rownames uses dimnames while row.names was written outside of R. They both also seem to work with higher dimensional arrays:

>a <- array(1:5, 1:4)
> a[1,,,]
> rownames(a) <- "a"
> row.names(a)
[1] "a"
> a
, , 1, 1    
  [,1] [,2]
a    1    2

> dimnames(a)
[1] "a"




How to find out when a particular table was created in Oracle?

You can query the data dictionary/catalog views to find out when an object was created as well as the time of last DDL involving the object (example: alter table)

select * 
  from all_objects 
 where owner = '<name of schema owner>'
   and object_name = '<name of table>'

The column "CREATED" tells you when the object was created. The column "LAST_DDL_TIME" tells you when the last DDL was performed against the object.

As for when a particular row was inserted/updated, you can use audit columns like an "insert_timestamp" column or use a trigger and populate an audit table

How to use this boolean in an if statement?

The problem here is

if (stop = true) is an assignation not a comparision.

Try if (stop == true)

Also take a look to the Top Ten Errors Java Programmers Make.

when exactly are we supposed to use "public static final String"?

The keyword final means that the value is constant(it cannot be changed). It is analogous to const in C.

And you can treat static as a global variable which has scope. It basically means if you change it for one object it will be changed for all just like a global variable(limited by scope).

Hope it helps.

Binding IIS Express to an IP Address

Below are the complete changes I needed to make to run my x64 bit IIS application using IIS Express, so that it was accessible to a remote host:

iisexpress /config:"C:\Users\test-user\Documents\IISExpress\config\applicationhost.config" /site:MyWebSite
Starting IIS Express ...
Successfully registered URL "" for site "MyWebSite" application "/"
Registration completed for site "MyWebSite"
IIS Express is running.
Enter 'Q' to stop IIS Express

The configuration file (applicationhost.config) had a section added as follows:

  <site name="MyWebsite" id="2">
    <application path="/" applicationPool="Clr4IntegratedAppPool">
      <virtualDirectory path="/" physicalPath="C:\build\trunk\MyWebsite" />
      <binding protocol="http" bindingInformation=":8080:" />

The 64 bit version of the .NET framework can be enabled as follows:

        <add name="ManagedEngine" image="%windir%\Microsoft.NET\Framework\v2.0.50727\webengine.dll" preCondition="integratedMode,runtimeVersionv2.0,bitness32" />
        <add name="ManagedEngineV4.0_32bit" image="%windir%\Microsoft.NET\Framework\v4.0.30319\webengine4.dll" preCondition="integratedMode,runtimeVersionv4.0,bitness32" />
    <add name="ManagedEngine64" image="%windir%\Microsoft.NET\Framework64\v4.0.30319\webengine4.dll" preCondition="integratedMode,runtimeVersionv4.0,bitness64" />

Javascript onload not working

Try this one:

<body onload="imageRefreshBig();">

Also you might want to check Javascript console for errors (in Chrome it's under Shift + Ctrl + J).

Oracle SQL query for Date format

if you are using same date format and have select query where date in oracle :

   select count(id) from Table_name where TO_DATE(Column_date)='07-OCT-2015';

To_DATE provided by oracle

Tensorflow r1.0 : could not a find a version that satisfies the requirement tensorflow

The TensorFlow package couldn't be found by the latest version of the "pip".
To be honest, I really don't know why this is...
but, the quick fix that worked out for me was:
[In case you are using a virtual environment]
downgrade the virtual environment to python-3.8.x and pip-20.2.x In case of anaconda, try:

conda install python=3.8

This should install the latest version of python-3.8 and pip-20.2.x for you.
And then, try

pip install tensorflow

Again, this worked fine for me, not sure if it'll work the same for you.

"Parser Error Message: Could not load type" in Global.asax

For my case, the web assembly was part of GAC... so after build, it need to installed in GAC and it worked.

Using Jquery AJAX function with datatype HTML

var datos = $("#id_formulario").serialize();
    url: "url.php",      
    type: "POST",                   
    dataType: "html",                 
    data: datos,                 
    success: function (prueba) { 

});//FIN  AJAX

Get a list of all the files in a directory (recursive)

The following works for me in Gradle / Groovy for build.gradle for an Android project, without having to import (NOTE: Does not recurse subdirectories, but when I found this solution I no longer cared about recursion, so you may not either):

FileCollection proGuardFileCollection = files { file('./proguard').listFiles() }
proGuardFileCollection.each {
    println "Proguard file located and processed: " + it

Initializing ArrayList with some predefined values

You can use Java 8 Stream API.
You can create a Stream of objects and collect them as a List.

private List<String> symbolsPresent = Stream.of("ONE", "TWO", "THREE", "FOUR")

Android, Java: HTTP POST Request

I used the following code to send HTTP POST from my android client app to C# desktop app on my server:

// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("");

try {
    // Add your data
    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
    nameValuePairs.add(new BasicNameValuePair("id", "12345"));
    nameValuePairs.add(new BasicNameValuePair("stringdata", "AndDev is Cool!"));
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

    // Execute HTTP Post Request
    HttpResponse response = httpclient.execute(httppost);

} catch (ClientProtocolException e) {
    // TODO Auto-generated catch block
} catch (IOException e) {
    // TODO Auto-generated catch block

I worked on reading the request from a C# app on my server (something like a web server little application). I managed to read request posted data using the following code:

server = new HttpListener();

HttpListenerContext context = server.GetContext();
HttpListenerContext context = obj as HttpListenerContext;
HttpListenerRequest request = context.Request;

StreamReader sr = new StreamReader(request.InputStream);
string str = sr.ReadToEnd();

How to Get True Size of MySQL Database?

if you want to find it in MB do this

SELECT table_schema                                        "DB Name", 
   Round(Sum(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
FROM   information_schema.tables 
GROUP  BY table_schema; 

How to catch a unique constraint error in a PL/SQL block?

As an alternative to explicitly catching and handling the exception you could tell Oracle to catch and automatically ignore the exception by including a /*+ hint */ in the insert statement. This is a little faster than explicitly catching the exception and then articulating how it should be handled. It is also easier to setup. The downside is that you do not get any feedback from Oracle that an exception was caught.

Here is an example where we would be selecting from another table, or perhaps an inner query, and inserting the results into a table called TABLE_NAME which has a unique constraint on a column called IDX_COL_NAME.

INSERT /*+ ignore_row_on_dupkey_index(TABLE_NAME(IDX_COL_NAME)) */ 
  , col_1
  , col_2
  , col_3
  , ...
  , col_n)
  , col_1
  , col_2
  , col_3
  , ...
  , col_n);

This is not a great solution if your goal it to catch and handle (i.e. print out or update the row that is violating the constraint). But if you just wanted to catch it and ignore the violating row then then this should do the job.

Fixed Table Cell Width

table td 

How to change the port number for Asp.Net core app?

Maybe it's because I am not using Core yet. My project didn't have a LaunchSettings.json file but that did prompt me to look in the project properties. I found it under the Web tab and simply changed the project url: enter image description here

What is a "cache-friendly" code?

Be aware that caches do not just cache continuous memory. They have multiple lines (at least 4) so discontinous and overlapping memory can often be stored just as efficiently.

What is missing from all the above examples is measured benchmarks. There are many myths about performance. Unless you measure it you do not know. Do not complicate your code unless you have a measured improvement.

Use a JSON array with objects with javascript

This is your dataArray:


Then parseJson can be used:

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

Store query result in a variable using in PL/pgSQL

As long as you are assigning a single variable, you can also use plain assignment in a plpgsql function:

name := (SELECT from test_table t where = x);

Or use SELECT INTO like @mu already provided.

This works, too:

name := from test_table t where = x;

But better use one of the first two, clearer methods, as @Pavel commented.

I shortened the syntax with a table alias additionally.
Update: I removed my code example and suggest to use IF EXISTS() instead like provided by @Pavel.