Programs & Examples On #Solrj

Solrj is a java client to access solr. It offers a java interface to add, update, and query the solr index. SolrJ hides a lot of the details of connecting to Solr and allows your application to interact with Solr with simple high-level methods.

Maven2: Missing artifact but jars are in place

Ohh what a mess! My advise: When its comes to messy poms or project packaging, Eclipse is really bad at showing the real problem. It will tell you some dependencies are missing, when in fact for pom is malformed or some other problem are present in your pom.

Leave Eclipse alone are run a maven install. You will get to the real problem really quick!

Move the most recent commit(s) to a new branch with Git

Had just this situation:

Branch one: A B C D E F     J   L M  
                       \ (Merge)
Branch two:             G I   K     N

I performed:

git branch newbranch 
git reset --hard HEAD~8 
git checkout newbranch

I expected that commit I would be the HEAD, but commit L is it now...

To be sure to land on the right spot in the history its easier to work with the hash of the commit

git branch newbranch 
git reset --hard #########
git checkout newbranch

How to Install gcc 5.3 with yum on CentOS 7.2?

The best approach to use yum and update your devtoolset is to utilize the CentOS SCLo RH Testing repository.

yum install centos-release-scl-rh
yum --enablerepo=centos-sclo-rh-testing install devtoolset-7-gcc devtoolset-7-gcc-c++

Many additional packages are also available, to see them all

yum --enablerepo=centos-sclo-rh-testing list devtoolset-7*

You can use this method to install any dev tool version, just swap the 7 for your desired version. devtoolset-6-gcc, devtoolset-5-gcc etc.

MySql server startup error 'The server quit without updating PID file '

After rebooting I had the same issue. Here is how I fixed it:

 sudo chown -R _mysql /usr/local/var/mysql

The APR based Apache Tomcat Native library was not found on the java.library.path

not found on the java.library.path: /usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib

The native lib is expected in one of the following locations


and not in


The files in tomcat/lib are all jar file and are added by tomcat to the classpath so that they are available to your application.

The native lib is needed by tomcat to perform better on the platform it is installed on and thus cannot be a jar, for linux it could be a .so file, for windows it could be a .dll file.

Just download the native library for your platform and place it in the one of the locations tomcat is expecting it to be.

Note that you are not required to have this lib for development/test purposes. Tomcat runs just fine without it.

org.apache.catalina.startup.Catalina start INFO: Server startup in 2882 ms


The output you are getting is very normal, it's just some logging outputs from tomcat, the line right above indicates that the server correctly started and is ready for operating.

If you are troubling with running your servlet then after the run on sever command eclipse opens a browser window (embeded (default) or external, depends on your config). If nothing shows on the browser, then check the url bar of the browser to see whether your servlet was requested or not.

It should be something like that



Try to call your servlet using the following url


Also each web project has a web.xml, you can find it in your project under WebContent\WEB-INF.

It is better to configure your servlets there using servlet-name servlet-class and url-mapping. It could look like that:

    <display-name>File counter - My first servlet</display-name>


In eclipse dynamic web project the default context name is the same as your project name.


will work too.

Push git commits & tags simultaneously

Maybe this helps someone:

git tag 0.0.1                    # creates tag locally     
git push origin 0.0.1            # pushes tag to remote

git tag --delete 0.0.1           # deletes tag locally    
git push --delete origin 0.0.1   # deletes remote tag

Oracle Trigger ORA-04098: trigger is invalid and failed re-validation

in my case, this error is raised due to sequence was not created..


How to get just the responsive grid from Bootstrap 3?

Go to and toggle just what you want from the BS3 framework and then click "Compile and Download" and you'll get the CSS and JS that you chose.

Bootstrap Customizer

Open up the CSS and remove all but the grid. They include some normalize stuff too. And you'll need to adjust all the styles on your site to box-sizing: border-box -

How do I check if a list is empty?

Being inspired by @dubiousjim's solution, I propose to use an additional general check of whether is it something iterable

import collections
def is_empty(a):
    return not a and isinstance(a, collections.Iterable)

Note: a string is considered to be iterable. - add and not isinstance(a,(str,unicode)) if you want the empty string to be excluded


>>> is_empty('sss')
>>> is_empty(555)
>>> is_empty(0)
>>> is_empty('')
>>> is_empty([3])
>>> is_empty([])
>>> is_empty({})
>>> is_empty(())

How to start an application using android ADB tools?

linux/mac users can also create a script to run an apk with something like the following:

create a file named "" with these 3 lines:

pkg=$(aapt dump badging $1|awk -F" " '/package/ {print $2}'|awk -F"'" '/name=/ {print $2}')
act=$(aapt dump badging $1|awk -F" " '/launchable-activity/ {print $2}'|awk -F"'" '/name=/ {print $2}')
adb shell am start -n $pkg/$act

then "chmod +x" to make it executable.

now you can simply: myapp.apk

The benefit here is that you don't need to know the package name or launchable activity name. Similarly, you can create " myapp.apk"

Note: This requires that you have aapt in your path. You can find it under the new build tools folder in the SDK.

How to add header row to a pandas DataFrame

Alternatively you could read you csv with header=None and then add it with df.columns:

Cov = pd.read_csv("path/to/file.txt", sep='\t', header=None)
Cov.columns = ["Sequence", "Start", "End", "Coverage"]

ValueError: cannot reshape array of size 30470400 into shape (50,1104,104)

It seems that there is a typo, since 1104*1104*50=60940800 and you are trying to reshape to dimensions 50,1104,104. So it seems that you need to change 104 to 1104.

Windows equivalent of the 'tail' command

you can also use Git bash where head and tail are emulated as well

How to configure Docker port mapping to use Nginx as an upstream proxy?

AJB's "Option B" can be made to work by using the base Ubuntu image and setting up nginx on your own. (It didn't work when I used the Nginx image from Docker Hub.)

Here is the Docker file I used:

FROM ubuntu
RUN apt-get update && apt-get install -y nginx
RUN ln -sf /dev/stdout /var/log/nginx/access.log
RUN ln -sf /dev/stderr /var/log/nginx/error.log
RUN rm -rf /etc/nginx/sites-enabled/default
EXPOSE 80 443
COPY conf/ /etc/nginx/sites-enabled/
CMD ["nginx", "-g", "daemon off;"]

My nginx config (aka: conf/

server {
    listen 80 default;

    location / {
        proxy_pass http://website;

upstream website {
    server website:3000;

And finally, how I start my containers:

$ docker run -dP --name website website
$ docker run -dP --name nginx --link website:website nginx

This got me up and running so my nginx pointed the upstream to the second docker container which exposed port 3000.

Efficient way to determine number of digits in an integer

for integer 'X' you want to know the number of digits , alright without using any loop , this solution act in one formula in one line only so this is the most optimal solution i have ever seen to this problem .

 int x = 1000 ; 
 cout<<numberOfDigits = 1+floor(log10(x))<<endl ; 

How to pass a variable to the SelectCommand of a SqlDataSource?

You can use the built in OnSelecting parameter of asp:SqlDataSource

Example: [.aspx file]

<asp:SqlDataSource ID="SqldsExample" runat="server"
SelectCommand="SELECT [SomeColumn], [AnotherColumn] 
               FROM [SomeTable]
               WHERE [Dynamic_Variable_Column] = @DynamicVariable"
    <asp:Parameter Name="DynamicVariable" Type="String"/>

Then in your code behind implement your OnSelecting method: [.aspx.cs]

protected void SqldsExample_Selecting(object sender, SqlDataSourceCommandEventArgs e)
     e.Command.Parameters["@DynamicVariable"].Value = (whatever value you want);

You can also use this for the other types of DB operations just implement your own methods:


How can I make the computer beep in C#?

The solution would be,


how to access downloads folder in android?

If you are using Marshmallow, you have to either:

  1. Request permissions at runtime (the user will get to allow or deny the request) or:
  2. The user must go into Settings -> Apps -> {Your App} -> Permissions and grant storage access.

This is because in Marshmallow, Google completely revamped how permissions work.

How to load CSS Asynchronously

The trick to triggering an asynchronous stylesheet download is to use a <link> element and set an invalid value for the media attribute (I'm using media="none", but any value will do). When a media query evaluates to false, the browser will still download the stylesheet, but it won't wait for the content to be available before rendering the page.

<link rel="stylesheet" href="css.css" media="none">

Once the stylesheet has finished downloading the media attribute must be set to a valid value so the style rules will be applied to the document. The onload event is used to switch the media property to all:

<link rel="stylesheet" href="css.css" media="none" onload="if(media!='all')media='all'">

This method of loading CSS will deliver useable content to visitors much quicker than the standard approach. Critical CSS can still be served with the usual blocking approach (or you can inline it for ultimate performance) and non-critical styles can be progressively downloaded and applied later in the parsing / rendering process.

This technique uses JavaScript, but you can cater for non-JavaScript browsers by wrapping the equivalent blocking <link> elements in a <noscript> element:

<link rel="stylesheet" href="css.css" media="none" onload="if(media!='all')media='all'"><noscript><link rel="stylesheet" href="css.css"></noscript>

You can see the operation in

enter image description here

Source in

paint() and repaint() in Java

The paint() method supports painting via a Graphics object.

The repaint() method is used to cause paint() to be invoked by the AWT painting thread.

Replace or delete certain characters from filenames of all files in a folder

Use PowerShell to do anything smarter for a DOS prompt. Here, I've shown how to batch rename all the files and directories in the current directory that contain spaces by replacing them with _ underscores.

Dir |
Rename-Item -NewName { $_.Name -replace " ","_" }

Optionally, the Where-Object command can be used to filter out ineligible objects for the successive cmdlet (command-let). The following are some examples to illustrate the flexibility it can afford you:

  • To skip any document files

    Dir |
    Where-Object { $_.Name -notmatch "\.(doc|xls|ppt)x?$" } |
    Rename-Item -NewName { $_.Name -replace " ","_" }
  • To process only directories (pre-3.0 version)

    Dir |
    Where-Object { $_.Mode -match "^d" } |
    Rename-Item -NewName { $_.Name -replace " ","_" }

    PowerShell v3.0 introduced new Dir flags. You can also use Dir -Directory there.

  • To skip any files already containing an underscore (or some other character)

    Dir |
    Where-Object { -not $_.Name.Contains("_") } |
    Rename-Item -NewName { $_.Name -replace " ","_" }

How to maximize the browser window in Selenium WebDriver (Selenium 2) using C#?

You can use Selenium Emulation in WebDriver:

selenium = new WebDriverBackedSelenium(driver,url);

How to refresh app upon shaking the device?

You might want to try open source tinybus. With it shake detection is as easy as this.

public class MainActivity extends Activity {

    private Bus mBus;

    protected void onCreate(Bundle savedInstanceState) {

        // Create a bus and attach it to activity
        mBus = TinyBus.from(this).wire(new ShakeEventWire());

    public void onShakeEvent(ShakeEvent event) {
        Toast.makeText(this, "Device has been shaken", 

    protected void onStart() {

    protected void onStop() {

It uses seismic for shake detection.

Add all files to a commit except a single file?

We can add all the files and exclude the file which has to be removed by git reset.

git add .
git reset -- <file_name_to_exclude>

getContext is not a function

I recently got this error because the typo, I write 'canavas' instead of 'canvas', hope this could help someone who is searching for this.

Is there a way to "limit" the result with ELOQUENT ORM of Laravel?

We can use LIMIT like bellow:


How do I create an executable in Visual Studio 2013 w/ C++?

All executable files from Visual Studio should be located in the debug folder of your project, e.g:

Visual Studio Directory: c:\users\me\documents\visual studio

Then the project which was called 'hello world' would be in the directory:

c:\users\me\documents\visual studio\hello world

And your exe would be located in:

c:\users\me\documents\visual studio\hello world\Debug\hello world.exe

Note the exe being named the same as the project.

Otherwise, you could publish it to a specified folder of your choice which comes with an installation, which would be good if you wanted to distribute it quickly


Everytime you build your project in VS, the exe is updated with the new one according to the code (as long as it builds without errors). When you publish it, you can choose the location, aswell as other factors, and the setup exe will be in that location, aswell as some manifest files and other files about the project.

Mysql service is missing

If you wish to have your config file on a different path you have to give your service a name:

mysqld --install NAME --defaults-file=C:\my-opts2.cnf

You can also use the name to install multiple mysql services listening on different sockets if you need that for some reason. You can see why it's failing by copying the execution path and adding --console to the end in the terminal. Finally, you can modify the starting path of a service by regediting:


That works well but it isn't as useful because the windows service mechanism provides little logging capabilities.

Python: How to convert datetime format?

@Tim's answer only does half the work -- that gets it into a datetime.datetime object.

To get it into the string format you require, you use datetime.strftime:

print(datetime.strftime('%b %d,%Y'))

css width: calc(100% -100px); alternative using jquery

Try jQuery animate() method, ex.


This app won't run unless you update Google Play Services (via Bazaar)

I solved these problem by doing the following steps:

  • In Emulator:

    You have to use the latest API Google APIs(Google Inc.)-API Level 19.

    Do the rest of the things placed in the screenshot itself.

    enter image description here

  • API Key:

    Create New API Key and Check carefully about Google Map API key and SHA Key.

  • Google Play Services:

    You have to download the latest Google Play Services that site if google play services wasn't working means you can find a lot of sites in internet named 4.8.20.apk.

    you can run the Google play Services by using the Command Prompt adb install 4.8.20.apk.

    Note: You have to download the latest Google play services because year by year latest version will be updated in internet.


    enter image description here

Regex to replace multiple spaces with a single space

var str = "The      dog        has a long tail,      and it is RED!";
str = str.replace(/ {2,}/g,' ');

EDIT: If you wish to replace all kind of whitespace characters the most efficient way would be like that:

str = str.replace(/\s{2,}/g,' ');

"inappropriate ioctl for device"

Odd errors like "inappropriate ioctl for device" are usually a result of checking $! at some point other than just after a system call failed. If you'd show your code, I bet someone would rapidly point out your error.

Initialize array of strings

There is no right way, but you can initialize an array of literals:

char **values = (char *[]){"a", "b", "c"};

or you can allocate each and initialize it:

char **values = malloc(sizeof(char*) * s);
    values[i] = malloc(sizeof(char) * l);
    values[i] = "hello";

Xcode 8 shows error that provisioning profile doesn't include signing certificate

I unchecked and then checked the "Automatically manage signing" option. That fixed it for me.

Plotting power spectrum in python

From the numpy fft page

When the input a is a time-domain signal and A = fft(a), np.abs(A) is its amplitude spectrum and np.abs(A)**2 is its power spectrum. The phase spectrum is obtained by np.angle(A).

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

I faced this error when I created second activity in my project in the newly updated Android Studio,I solved it simply by copy pasting the whole xml code from first layout to the second and then I just removed the code that's unnecessary.

Which MySQL datatype to use for an IP address?

Since IPv4 addresses are 4 byte long, you could use an INT (UNSIGNED) that has exactly 4 bytes:


And INET_ATON and INET_NTOA to convert them:

INSERT INTO `table` (`ipv4`) VALUES (INET_ATON(""));
SELECT INET_NTOA(`ipv4`) FROM `table`;

For IPv6 addresses you could use a BINARY instead:

`ipv6` BINARY(16)

And use PHP’s inet_pton and inet_ntop for conversion:

'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_escape_string(inet_pton('2001:4860:a005::68')).'")'
'SELECT `ipv6` FROM `table`'
$ipv6 = inet_pton($row['ipv6']);

Why does calling sumr on a stream with 50 tuples not complete

sumr is implemented in terms of foldRight:

 final def sumr(implicit A: Monoid[A]): A = F.foldRight(self, 

foldRight is not always tail recursive, so you can overflow the stack if the collection is too long. See Why foldRight and reduceRight are NOT tail recursive? for some more discussion of when this is or isn't true.

Linux configure/make, --prefix?

In my situation, --prefix= failed to update the path correctly under some warnings or failures. please see the below link for the answer.

.substring error: "is not a function"

you can also quote string


Smooth scrolling with just pure css

You can do this with pure CSS but you will need to hard code the offset scroll amounts, which may not be ideal should you be changing page content- or should dimensions of your content change on say window resize.

You're likely best placed to use e.g. jQuery, specifically:

$('html, body').stop().animate({
   scrollTop: element.offset().top
}, 1000);

A complete implementation may be:

$('#up, #down').on('click', function(e){
    var target= $(this).get(0).id == 'up' ? $('#down') : $('#up');
    $('html, body').stop().animate({
       scrollTop: target.offset().top
    }, 1000);

Where element is the target element to scroll to and 1000 is the delay in ms before completion.

Demo Fiddle

The benefit being, no matter what changes to your content dimensions, the function will not need to be altered.

Update React component every second

In the component's componentDidMount lifecycle method, you can set an interval to call a function which updates the state.

 componentDidMount() {
      setInterval(() => this.setState({ time:}), 1000)

jQuery get html of container including the container itself


Update: outerHTML works on firefox now so use the other answer unless you need to support very old versions of firefox

How can I create a unique constraint on my column (SQL Server 2008 R2)?

Here's another way through the GUI that does exactly what your script does even though it goes through Indexes (not Constraints) in the object explorer.

  1. Right click on "Indexes" and click "New Index..." (note: this is disabled if you have the table open in design view)

enter image description here

  1. Give new index a name ("U_Name"), check "Unique", and click "Add..."

enter image description here

  1. Select "Name" column in the next windown

enter image description here

  1. Click OK in both windows

Angular 2: 404 error occur when I refresh through the browser

I had the same problem. My Angular application is running on a Windows server.

I solved this problem by making a web.config file in the root directory.

<?xml version="1.0" encoding="UTF-8"?>
        <rule name="AngularJS" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
            <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />
          <action type="Rewrite" url="/" />

How to make java delay for a few seconds?

Use Thread.sleep(2000); //2000 for 2 seconds

What is the HTML unicode character for a "tall" right chevron?

From the description and from the reference to the search box in the Ubuntu site, I gather that you actually want an arrowhead character pointing to the right. There are no Unicode characters designed to be used as arrowheads, but some of them may visually resemble an arrowhead.

In particular, if you draw your idea of the character at, you will find many suggestions, such as “>” RIGHT-POINTING ANGLE BRACKET' (U+232A) and “?” MEDIUM RIGHT-POINTING ANGLE BRACKET ORNAMENT (U+276D).

Such characters generally have limited support in fonts, so you would need to carefully write a longish font-family list or to use a downloadable font. See my Guide to using special characters in HTML.

Especially if the intended use is as a symbol in a search box, as the reference to the Ubuntu page suggests, it is questionable whether you should use a character at all. It’s not really an element of text here; rather, a graphic symbol that accompanies text but isn’t a part of it. So why take all the trouble with using a character (safely), when it isn’t really a character?

RecyclerView: Inconsistency detected. Invalid item position

i once got the error too:

Cause: I was trying to update a Recycler View from an Async task while simultaneously trying to get old deleted viewHolders;

Code: I generate data at the press of a button, logic as follows

  1. Clear the last items in the recycler view
  2. Call async task to generate data
  3. OnPostExecute Update the Recycler view and NotifyDataSetChanged

Problem: Whenever i scroll fast before generating my data i get

Inconsistency detected. Invalid view holder adapter positionViewHolder java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid item position 20(offset:2).state:3

Solution: instead of clearing the RecyclerView before generating my data, i instead leave it and then Replace it with the New Data, the Call NotifyDatasetChanged, as shown below;

        protected void onPostExecute(List<Objects> o) {

Passing parameters to a Bash function

It takes two numbers from the user, feeds them to the function called add (in the very last line of the code), and add will sum them up and print them.


read -p "Enter the first  value: " x
read -p "Enter the second value: " y

    arg1=$1 # arg1 gets to be the first  assigned argument (note there are no spaces)
      arg2=$2 # arg2 gets to be the second assigned argument (note there are no spaces)

    echo $(($arg1 + $arg2))

add x y # Feeding the arguments

How to grep with a list of words

You need to use the option -f:

$ grep -f A B

The option -F does a fixed string search where as -f is for specifying a file of patterns. You may want both if the file only contains fixed strings and not regexps.

$ grep -Ff A B

You may also want the -w option for matching whole words only:

$ grep -wFf A B

Read man grep for a description of all the possible arguments and what they do.

can't load package: package .: no buildable Go source files

You should check the $GOPATH directory. If there is an empty directory of the package name, go get doesn't download the package from the repository.

For example, If I want to get the package from it's github repository, and there is already an empty directory in the $GOPATH, go get doesn't download the package and then complains that there is no buildable Go source file in the directory. Delete any empty directory first of all.

What is the difference between the | and || or operators?

& - (Condition 1 & Condition 2): checks both cases even if first one is false

&& - (Condition 1 && Condition 2): dosen't bother to check second case if case one is false

&& - operator will make your code run faster, professionally & is rarely used

| - (Condition 1 | Condition 2): checks both cases even if case 1 is true

|| - (Condition 1 || Condition 2): dosen't bother to check second case if first one is true

|| - operator will make your code run faster, professionally | is rarely used

"element.dispatchEvent is not a function" js error caught in firebug of FF3.0

check for this by calling the library jquery after the noconflict.js or that this calling more than once jquery library after the noconflict.js

Changing the default title of confirm() in JavaScript?

This is not possible, as you say, from a security stand point. The only way you could simulate it, is by creating a modeless dialog window.

There are many third-party javascript-plugins that you could use to fake this effect so you do not have to write all that code.

Change URL and redirect using jQuery

jQuery does not have an option for this, nor should it have one. This is perfectly valid javascript and there is no reason for jQuery to provide wrapper functions for this.

jQuery is just a library on top of javascript, even if you use jQuery you can still use normal javascript.

Btw window.location is not a function but a property which you should set like this:

window.location = url;

Apply CSS styles to an element depending on its child elements

As far as I'm aware, styling a parent element based on the child element is not an available feature of CSS. You'll likely need scripting for this.

It'd be wonderful if you could do something like div[div.a] or div:containing[div.a] as you said, but this isn't possible.

You may want to consider looking at jQuery. Its selectors work very well with 'containing' types. You can select the div, based on its child contents and then apply a CSS class to the parent all in one line.

If you use jQuery, something along the lines of this would may work (untested but the theory is there):

$('div:has(div.a)').css('border', '1px solid red');



combined with a CSS class:

    border: 1px solid red;

Here's the documentation for the jQuery "has" selector.

Adding items to an object through the .push() method

Another way of doing it would be:

stuff = Object.assign(stuff, {$(this).attr('value'):$(this).attr('checked')});

Read more here: Object.assign()

Redirect to external URL with return in laravel

You should be able to redirect to the url like this

return Redirect::to($url);

You can read about Redirects in the Laravel docs here.

In Python how should I test if a variable is None, True or False

Don't fear the Exception! Having your program just log and continue is as easy as:

    result = simulate(open("myfile"))
except SimulationException as sim_exc:
    print "error parsing stream", sim_exc
    if result:
        print "result pass"
        print "result fail"

# execution continues from here, regardless of exception or not

And now you can have a much richer type of notification from the simulate method as to what exactly went wrong, in case you find error/no-error not to be informative enough.

Are email addresses case sensitive?

Per @l3x, it depends.

There are clearly two sets of general situations where the correct answer can be different, along with a third which is not as general:

a) You are a user sending private mails:

Very few modern email systems implement case sensitivity, so you are probably fine to ignore case and choose whatever case you feel like using. There is no guarantee that all your mails will be delivered - but so few mails would be negatively affected that you should not worry about it.

b) You are developing mail software:

See RFC5321 2.4 excerpt at the bottom.

When you are developing mail software, you want to be RFC-compliant. You can make your own users' email addresses case insensitive if you want to (and you probably should). But in order to be RFC compliant, you MUST treat outside addresses as case sensitive.

c) Managing business-owned lists of email addresses as an employee:

It is possible that the same email recipient is added to a list more than once - but using different case. In this situation though the addresses are technically different, it might result in a recipient receiving duplicate emails. How you treat this situation is similar to situation a) in that you are probably fine to treat them as duplicates and to remove a duplicate entry. It is better to treat these as special cases however, by sending a "reminder" mail to both addresses to ask them if the case of the email address is accurate.

From a legal standpoint, if you remove a duplicate without acknowledgement/permission from both addresses, you can be held responsible for leaking private information/authentication to an unauthorised address simply because two actually-separate recipients have the same address with different cases.

Excerpt from RFC5321 2.4:

The local-part of a mailbox MUST BE treated as case sensitive. Therefore, SMTP implementations MUST take care to preserve the case of mailbox local-parts. In particular, for some hosts, the user "smith" is different from the user "Smith". However, exploiting the case sensitivity of mailbox local-parts impedes interoperability and is discouraged.

How to paginate with Mongoose in Node.js?

search = productName,

page = 1

// Pagination
router.get("/search/:page", (req, res, next) => {
  const resultsPerPage = 5;
  const page = >= 1 ? : 1;
  const query =;

 page = page - 1 

  Product.find({ name: query })
    .sort({ name: "asc" })
    .skip(resultsPerPage * page)
    .then((results) => {
      return res.status(200).send(results);
    .catch((err) => {
      return res.status(500).send(err);

UIView Infinite 360 degree rotation animation?

Nate's answer above is ideal for stop and start animation and gives a better control. I was intrigued why yours didn't work and his does. I wanted to share my findings here and a simpler version of the code that would animate a UIView continuously without stalling.

This is the code I used,

- (void)rotateImageView
    [UIView animateWithDuration:1 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
        [self.imageView setTransform:CGAffineTransformRotate(self.imageView.transform, M_PI_2)];
    }completion:^(BOOL finished){
        if (finished) {
            [self rotateImageView];

I used 'CGAffineTransformRotate' instead of 'CGAffineTransformMakeRotation' because the former returns the result which is saved as the animation proceeds. This will prevent the jumping or resetting of the view during the animation.

Another thing is not to use 'UIViewAnimationOptionRepeat' because at the end of the animation before it starts repeating, it resets the transform making the view jump back to its original position. Instead of a repeat, you recurse so that the transform is never reset to the original value because the animation block virtually never ends.

And the last thing is, you have to transform the view in steps of 90 degrees (M_PI / 2) instead of 360 or 180 degrees (2*M_PI or M_PI). Because transformation occurs as a matrix multiplication of sine and cosine values.

t' =  [ cos(angle) sin(angle) -sin(angle) cos(angle) 0 0 ] * t

So, say if you use 180-degree transformation, the cosine of 180 yields -1 making the view transform in opposite direction each time (Note-Nate's answer will also have this issue if you change the radian value of transformation to M_PI). A 360-degree transformation is simply asking the view to remain where it was, hence you don't see any rotation at all.

Split string with delimiters in C

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

 *  splits str on delim and dynamically allocates an array of pointers.
 *  On error -1 is returned, check errno
 *  On success size of array is returned, which may be 0 on an empty string
 *  or 1 if no delim was found.  
 *  You could rewrite this to return the char ** array instead and upon NULL
 *  know it's an allocation problem but I did the triple array here.  Note that
 *  upon the hitting two delim's in a row "foo,,bar" the array would be:
 *  { "foo", NULL, "bar" } 
 *  You need to define the semantics of a trailing delim Like "foo," is that a
 *  2 count array or an array of one?  I choose the two count with the second entry
 *  set to NULL since it's valueless.
 *  Modifies str so make a copy if this is a problem
int split( char * str, char delim, char ***array, int *length ) {
  char *p;
  char **res;
  int count=0;
  int k=0;

  p = str;
  // Count occurance of delim in string
  while( (p=strchr(p,delim)) != NULL ) {
    *p = 0; // Null terminate the deliminator.
    p++; // Skip past our new null

  // allocate dynamic array
  res = calloc( 1, count * sizeof(char *));
  if( !res ) return -1;

  p = str;
  for( k=0; k<count; k++ ){
    if( *p ) res[k] = p;  // Copy start of string
    p = strchr(p, 0 );    // Look for next null
    p++; // Start of next string

  *array = res;
  *length = count;

  return 0;


int main() {
  char **res;
  int k=0;
  int count =0;
  int rc;

  rc = split( str, ',', &res, &count );
  if( rc ) {
    printf("Error: %s errno: %d \n", strerror(errno), errno);

  printf("count: %d\n", count );
  for( k=0; k<count; k++ ) {
    printf("str: %s\n", res[k]);

  free(res );
  return 0;

SQL to LINQ Tool

Edit 7/17/2020: I cannot delete this accepted answer. It used to be good, but now it isn't. Beware really old posts, guys. I'm removing the link.

[Linqer] is a SQL to LINQ converter tool. It helps you to learn LINQ and convert your existing SQL statements.

Not every SQL statement can be converted to LINQ, but Linqer covers many different types of SQL expressions. Linqer supports both .NET languages - C# and Visual Basic.

How can I update NodeJS and NPM to the next versions?

Warning: if you need update Node from an old version (in my case v4.6.0) it is better to re-install nodejs from scratch (download link: otherwise npm will also update itself to a version that's not compatible with the new Node (see this discussion).

This is the error message that I got after updating Node (on Windows) with npm

$ npm install -g npm stable
[ . . .]
$ npm 
      let notifier = require('update-notifier')({pkg})

SyntaxError: Block-scoped declarations (let, const, function, class) not yet supporte
d outside strict mode
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:373:25)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Function.Module.runMain (module.js:441:10)
    at startup (node.js:139:18)
    at node.js:974:3

After new installation npm works again:

$ npm -v
$ node -v

How can I group by date time column without taking time into consideration

CAST datetime field to date

select  CAST(datetime_field as DATE), count(*) as count from table group by CAST(datetime_field as DATE);

Problems with local variable scope. How to solve it?

not Error:

JSONObject json1 = getJsonX();


JSONObject json2 = null;
if(x == y)
   json2 = getJSONX();

Error: Local variable statement defined in an enclosing scope must be final or effectively final.

But you can write:

JSONObject json2 = (x == y) ? json2 = getJSONX() : null;

Find which commit is currently checked out in Git

You can just do:

git rev-parse HEAD

To explain a bit further: git rev-parse is git's basic command for interpreting any of the exotic ways that you can specify the name of a commit and HEAD is a reference to your current commit or branch. (In a git bisect session, it points directly to a commit ("detached HEAD") rather than a branch.)

Alternatively (and easier to remember) would be to just do:

git show

... which defaults to showing the commit that HEAD points to. For a more concise version, you can do:

$ git show --oneline -s
c0235b7 Autorotate uploaded images based on EXIF orientation

How to get a list of all files in Cloud Storage in a Firebase app?

Since Mar 2017: With the addition of Firebase Cloud Functions, and Firebase's deeper integration with Google Cloud, this is now possible.

With Cloud Functions you can use the Google Cloud Node package to do epic operations on Cloud Storage. Below is an example that gets all the file URLs into an array from Cloud Storage. This function will be triggered every time something's saved to google cloud storage.

Note 1: This is a rather computationally expensive operation, as it has to cycle through all files in a bucket / folder.

Note 2: I wrote this just as an example, without paying much detail into promises etc. Just to give an idea.

const functions = require('firebase-functions');
const gcs = require('@google-cloud/storage')();

// let's trigger this function with a file upload to google cloud storage

exports.fileUploaded = => {

  const object =; // the object that was just uploaded
  const bucket = gcs.bucket(object.bucket);
  const signedUrlConfig = { action: 'read', expires: '03-17-2025' }; // this is a signed url configuration object

  var fileURLs = []; // array to hold all file urls 

  // this is just for the sake of this example. Ideally you should get the path from the object that is uploaded :)
  const folderPath = "a/path/you/want/its/folder/size/calculated";

  bucket.getFiles({ prefix: folderPath }, function(err, files) {
    // files = array of file objects
    // not the contents of these files, we're not downloading the files. 

    files.forEach(function(file) {
      file.getSignedUrl(signedUrlConfig, function(err, fileURL) {



I hope this will give you the general idea. For better cloud functions examples, check out Google's Github repo full of Cloud Functions samples for Firebase. Also check out their Google Cloud Node API Documentation

Reading settings from app.config or web.config in .NET

If your needing/wanting to use the ConfigurationManager class...

You may need to load System.Configuration.ConfigurationManager by Microsoft via NuGet Package Manager

Tools->NuGet Package Manager->Manage NuGet Packages for Solution...

Microsoft Docs

One thing worth noting from the docs...

If your application needs read-only access to its own configuration, we recommend that you use the GetSection(String) method. This method provides access to the cached configuration values for the current application, which has better performance than the Configuration class.

Make $JAVA_HOME easily changable in Ubuntu

Put the environment variables into the global /etc/environment file:

export JAVA_HOME=/usr/lib/jvm/java-1.5.0-sun

Execute "source /etc/environment" in every shell where you want the variables to be updated:

$ source /etc/environment

Check that it works:

$ echo $JAVA_HOME
$ /usr/lib/jvm/java-1.5.0-sun

Great, no logout needed.

If you want to set JAVA_HOME environment variable in only the terminal, set it in ~/.bashrc file.

Create two blank lines in Markdown


This HTML entity which means "non-breaking space" will help you for each line break

Unable to negotiate with XX.XXX.XX.XX: no matching host key type found. Their offer: ssh-dss

You can also add -oHostKeyAlgorithms=+ssh-dss in your ssh line:

ssh -oHostKeyAlgorithms=+ssh-dss user@host

How do I use a regex in a shell script?

I think this is what you want:


echo "$1" | grep -P -q $REGEX_DATE
echo $?

I've used the -P switch to get perl regex.

How to round to 2 decimals with Python?

Most answers suggested round or format. round sometimes rounds up, and in my case I needed the value of my variable to be rounded down and not just displayed as such.

round(2.357, 2)  # -> 2.36

I found the answer here: How do I round a floating point number up to a certain decimal place?

import math
v = 2.357
print(math.ceil(v*100)/100)  # -> 2.36
print(math.floor(v*100)/100)  # -> 2.35


from math import floor, ceil

def roundDown(n, d=8):
    d = int('1' + ('0' * d))
    return floor(n * d) / d

def roundUp(n, d=8):
    d = int('1' + ('0' * d))
    return ceil(n * d) / d

How do I import material design library to Android Studio?

First, add the Material Design dependency.

implementation '<version>'

To get the latest material design library version. check the official website github repository.

Current version is 1.2.0.

So, you have to add,

implementation ''

Then, you need to change the app theme to material theme by adding,

<style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>

in your style.xml. Dont forget to set the same theme in your application theme in your manifest file.

Excel: VLOOKUP that returns true or false?

ISNA is the best function to use. I just did. I wanted all cells whose value was NOT in an array to conditionally format to a certain color.


How to specify an alternate location for the .m2 folder or settings.xml permanently?

You can change the default location of .m2 directory in m2.conf file. It resides in your maven installation directory.

add modify this line in


set maven.home C:\Users\me\.m2

Random shuffling of an array

I'm weighing in on this very popular question because nobody has written a shuffle-copy version. Style is borrowed heavily from, because who isn't pillaging Java technology these days? Generic and int implementations included.

    * Shuffles elements from {@code original} into a newly created array.
    * @param original the original array
    * @return the new, shuffled array
    * @throws NullPointerException if {@code original == null}
   public static <T> T[] shuffledCopy(T[] original) {
      int originalLength = original.length; // For exception priority compatibility.
      Random random = new Random();
      T[] result = (T[]) Array.newInstance(original.getClass().getComponentType(), originalLength);

      for (int i = 0; i < originalLength; i++) {
         int j = random.nextInt(i+1);
         result[i] = result[j];
         result[j] = original[i];

      return result;

    * Shuffles elements from {@code original} into a newly created array.
    * @param original the original array
    * @return the new, shuffled array
    * @throws NullPointerException if {@code original == null}
   public static int[] shuffledCopy(int[] original) {
      int originalLength = original.length;
      Random random = new Random();
      int[] result = new int[originalLength];

      for (int i = 0; i < originalLength; i++) {
         int j = random.nextInt(i+1);
         result[i] = result[j];
         result[j] = original[i];

      return result;

How to use classes from .jar files?

You need to put the .jar file into your classpath when compiling/running your code. Then you just use standard imports of the classes in the .jar.

getColor(int id) deprecated on Android 6.0 Marshmallow (API 23)

I don't want to include the Support library just for getColor, so I'm using something like

public static int getColorWrapper(Context context, int id) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        return context.getColor(id);
    } else {
        //noinspection deprecation
        return context.getResources().getColor(id);

I guess the code should work just fine, and the deprecated getColor cannot disappear from API < 23.

And this is what I'm using in Kotlin:

 * Returns a color associated with a particular resource ID.
 * Wrapper around the deprecated [Resources.getColor][android.content.res.Resources.getColor].
fun getColorHelper(context: Context, @ColorRes id: Int) =
    if (Build.VERSION.SDK_INT >= 23) context.getColor(id) else context.resources.getColor(id);

Angular HTML binding

I apologize if I am missing the point here, but I would like to recommend a different approach:

I think it's better to return raw data from your server side application and bind it to a template on the client side. This makes for more nimble requests since you're only returning json from your server.

To me it doesn't seem like it makes sense to use Angular if all you're doing is fetching html from the server and injecting it "as is" into the DOM.

I know Angular 1.x has an html binding, but I have not seen a counterpart in Angular 2.0 yet. They might add it later though. Anyway, I would still consider a data api for your Angular 2.0 app.

I have a few samples here with some simple data binding if you are interested:

How can I set a UITableView to grouped style

If i understand what you mean, you have to initialize your controller with that style. Something like:

myTVContoller = [[UITableViewController alloc] initWithStyle:UITableViewStyleGrouped];

How can I check if my Element ID has focus?

Compare document.activeElement with the element you want to check for focus. If they are the same, the element is focused; otherwise, it isn't.

// dummy element
var dummyEl = document.getElementById('myID');

// check for focus
var isFocused = (document.activeElement === dummyEl);

hasFocus is part of the document; there's no such method for DOM elements.

Also, document.getElementById doesn't use a # at the beginning of myID. Change this:

var dummyEl = document.getElementById('#myID');

to this:

var dummyEl = document.getElementById('myID');

If you'd like to use a CSS query instead you can use querySelector (and querySelectorAll).

MySQL: Can't create table (errno: 150)

A real edge case is where you have used an MySQL tool, (Sequel Pro in my case) to rename a database. Then created a database with the same name.

This kept foreign key constraints to the same database name, so the renamed database (e.g. my_db_renamed) had foreign key constraints in the newly created database (my_db)

Not sure if this is a bug in Sequel Pro, or if some use case requires this behaviour, but it cost me best part of a morning :/

How to change the project in GCP using CLI commands

Make sure you are authenticated with the correct account:

gcloud auth list
* account 1
  account 2

Change to the project's account if not:

gcloud config set account `ACCOUNT`

Depending on the account, the project list will be different:

gcloud projects list

- project 1
- project 2...

Switch to intended project:

gcloud config set project `PROJECT ID`

How to iterate over array of objects in Handlebars?

You can pass this to each block. See here:

{{#each this}}
    <div class="row"></div>

How to use Oracle ORDER BY and ROWNUM correctly?

Documented couple of design issues with this in a comment above. Short story, in Oracle, you need to limit the results manually when you have large tables and/or tables with same column names (and you don't want to explicit type them all out and rename them all). Easy solution is to figure out your breakpoint and limit that in your query. Or you could also do this in the inner query if you don't have the conflicting column names constraint. E.g.

WHERE m_api_log.created_date BETWEEN TO_DATE('10/23/2015 05:00', 'MM/DD/YYYY HH24:MI') 
                                 AND TO_DATE('10/30/2015 23:59', 'MM/DD/YYYY HH24:MI')  

will cut down the results substantially. Then you can ORDER BY or even do the outer query to limit rows.

Also, I think TOAD has a feature to limit rows; but, not sure that does limiting within the actual query on Oracle. Not sure.

Cannot bulk load. Operating system error code 5 (Access is denied.)

This is what worked for me:

Log on SSIS with Windows authentication.

1. Open services and find MSSQL NT Service account name and copy it:

enter image description here

2. Open folder from which SQL server should read from. Security - Group or user names tab - Add and paste there copied account:**

enter image description here

  1. You will probably get "Multiple names found error", just select MSSQL user:

enter image description here

Your BULK INSERT query should run fine now. If problem persists try adding SQL Server Agent account to folder permissions in same way. Make sure you restart MSSQL server in services after you are done.

How to convert a Hibernate proxy to a real entity object

Starting from Hiebrnate 5.2.10 you can use Hibernate.proxy method to convert a proxy to your real entity:

MyEntity myEntity = (MyEntity) Hibernate.unproxy( proxyMyEntity );

Apply multiple functions to multiple groupby columns

This is a twist on 'exans' answer that uses Named Aggregations. It's the same but with argument unpacking which allows you to still pass in a dictionary to the agg function.

The named aggs are a nice feature, but at first glance might seem hard to write programmatically since they use keywords, but it's actually simple with argument/keyword unpacking.

animals = pd.DataFrame({'kind': ['cat', 'dog', 'cat', 'dog'],
                         'height': [9.1, 6.0, 9.5, 34.0],
                         'weight': [7.9, 7.5, 9.9, 198.0]})
agg_dict = {
    "min_height": pd.NamedAgg(column='height', aggfunc='min'),
    "max_height": pd.NamedAgg(column='height', aggfunc='max'),
    "average_weight": pd.NamedAgg(column='weight', aggfunc=np.mean)


The Result

      min_height  max_height  average_weight
cat          9.1         9.5            8.90
dog          6.0        34.0          102.75

How to count certain elements in array?

If you are using lodash or underscore the _.countBy method will provide an object of aggregate totals keyed by each value in the array. You can turn this into a one-liner if you only need to count one value:

_.countBy(['foo', 'foo', 'bar'])['foo']; // 2

This also works fine on arrays of numbers. The one-liner for your example would be:

_.countBy([1, 2, 3, 5, 2, 8, 9, 2])[2]; // 3

EditText non editable

android:editable="false" should work, but it is deprecated, you should be using android:inputType="none" instead.

Alternatively, if you want to do it in the code you could do this :

EditText mEdit = (EditText) findViewById(;

This is also a viable alternative :

EditText mEdit = (EditText) findViewById(;

If you're going to make your EditText non-editable, may I suggest using the TextView widget instead of the EditText, since using a EditText seems kind of pointless in that case.

EDIT: Altered some information since I've found that android:editable is deprecated, and you should use android:inputType="none", but there is a bug about it on android code; So please check this.

Remove certain characters from a string

One issue with REPLACE will be where city names contain the district name. You can use something like.

SELECT SUBSTRING(O.Ort, LEN(C.CityName) + 2, 8000)
FROM   dbo.tblOrtsteileGeo O
       JOIN dbo.Cities C
         ON =
WHERE  O.GKZ = '06440004' 

How can I check if a value is of type Integer?

If input value can be in numeric form other than integer , check by

if (x == (int)x)
   // Number is integer

If string value is being passed , use Integer.parseInt(string_var). Please ensure error handling using try catch in case conversion fails.

How to install packages offline?

I had a similar problem. And i had to make it install the same way, we do from pypi.

I did the following things:

  1. Make a directory to store all the packages in the machine that have internet access.

    mkdir -p /path/to/packages/
  2. Download all the packages to the path

Edit: You can also try:

python3 -m pip wheel --no-cache-dir -r requirements.txt -w /path/to/packages
pip download -r requirements.txt -d /path/to/packages

Eg:- ls /root/wheelhouse/  # **/root/wheelhouse** is my **/path/to/packages/**
total 4524
-rw-r--r--. 1 root root   16667 May 23  2017 incremental-17.5.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root   34713 Sep  1 10:21 attrs-18.2.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root 3088398 Oct 15 14:41 Twisted-18.9.0.tar.bz2
-rw-r--r--. 1 root root  133356 Jan 28 15:58 chardet-3.0.4-py2.py3-none-any.whl
-rw-r--r--. 1 root root  154154 Jan 28 15:58 certifi-2018.11.29-py2.py3-none-any.whl
-rw-r--r--. 1 root root   57987 Jan 28 15:58 requests-2.21.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root   58594 Jan 28 15:58 idna-2.8-py2.py3-none-any.whl
-rw-r--r--. 1 root root  118086 Jan 28 15:59 urllib3-1.24.1-py2.py3-none-any.whl
-rw-r--r--. 1 root root   47229 Jan 28 15:59 tqdm-4.30.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root    7922 Jan 28 16:13 constantly-15.1.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root  164706 Jan 28 16:14 zope.interface-4.6.0-cp27-cp27mu-manylinux1_x86_64.whl
-rw-r--r--. 1 root root  573841 Jan 28 16:14 setuptools-40.7.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root   37638 Jan 28 16:15 Automat-0.7.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root   37905 Jan 28 16:15 hyperlink-18.0.0-py2.py3-none-any.whl
-rw-r--r--. 1 root root   52311 Jan 28 16:15 PyHamcrest-1.9.0-py2.py3-none-any.whl
 -rw-r--r--. 1 root root   10586 Jan 28 16:15 six-1.12.0-py2.py3-none-any.whl
  1. Tar the packages directory and copy it to the Machine that doesn't have internet access. Then do,

    cd /path/to/packages/
    tar -cvzf packages.tar.gz .  # not the . (dot) at the end

Copy the packages.tar.gz into the destination machine that doesn't have internet access.

  1. In the machine that doesn't have internet access, do the following (Assuming you copied the tarred packages to /path/to/package/ in the current machine)

    cd /path/to/packages/
    tar -xvzf packages.tar.gz
    mkdir -p $HOME/.config/pip/
    vi $HOME/.config/pip/pip.conf

and paste the following content inside and save it.

timeout = 10
find-links = file:///path/to/package/
no-cache-dir = true
no-index = true
  1. Finally, i suggest you use, some form of virtualenv for installing the packages.

    virtualenv -p python2 venv # use python3, if you are on python3
    source ./venv/bin/activate
    pip install <package>

You should be able to download all the modules that are in the directory /path/to/package/.

Note: I only did this, because i couldn't add options or change the way we install the modules. Otherwise i'd have done

pip install --no-index --find-links /path/to/download/dir/ -r requirements.txt

git discard all changes and pull from upstream

git reset <hash>  # you need to know the last good hash, so you can remove all your local commits

git fetch upstream
git checkout master
git merge upstream/master
git push origin master -f

voila, now your fork is back to same as upstream.

Escaping a forward slash in a regular expression

What context/language? Some languages use / as the pattern delimiter, so yes, you need to escape it, depending on which language/context. You escape it by putting a backward slash in front of it: \/ For some languages (like PHP) you can use other characters as the delimiter and therefore you don't need to escape it. But AFAIK in all languages, the only special significance the / has is it may be the designated pattern delimiter.

Erasing elements from a vector

Use the remove/erase idiom:

std::vector<int>& vec = myNumbers; // use shorter name
vec.erase(std::remove(vec.begin(), vec.end(), number_in), vec.end());

What happens is that remove compacts the elements that differ from the value to be removed (number_in) in the beginning of the vector and returns the iterator to the first element after that range. Then erase removes these elements (whose value is unspecified).

How can I style an Android Switch?

It's an awesome detailed reply by Janusz. But just for the sake of people who are coming to this page for answers, the easier way is at (dead link) linked from Android Asset Studio

A good description of all the tools are at (site offline now)

However, I highly recommend everybody to read the reply from Janusz as it will make understanding clearer. Use the tool to do stuffs real quick

What does it mean to inflate a view from an xml file?

Inflating is the process of adding a view (.xml) to activity on runtime. When we create a listView we inflate each of its items dynamically. If we want to create a ViewGroup with multiple views like buttons and textview, we can create it like so:

Button but = new Button();
but.setText ="button text";
but.background ...
but.leftDrawable.. and so on...

TextView txt = new TextView();
txt.setText ="button text";
txt.background ... and so on...

Then we have to create a layout where we can add above views:

RelativeLayout rel = new RelativeLayout();


And now if we want to add a button in the right-corner and a textview on the bottom, we have to do a lot of work. First by instantiating the view properties and then applying multiple constraints. This is time consuming.

Android makes it easy for us to create a simple .xml and design its style and attributes in xml and then simply inflate it wherever we need it without the pain of setting constraints programatically.

LayoutInflater inflater = 
View menuLayout = inflater.inflate(R.layout.your_menu_layout, mainLayout, true);
//now add menuLayout to wherever you want to add like


Python 3 string.join() equivalent?

There are method join for string objects:


Compare objects in Angular

Bit late on this thread. angular.equals does deep check, however does anyone know that why its behave differently if one of the member contain "$" in prefix ?

You can try this Demo with following input

var obj3 = {}
obj3.a=  "b";
obj3.b.$c =true;

var obj4 = {}
obj4.a=  "b";
obj4.b.$c =true;


How to pass IEnumerable list to controller in MVC including checkbox state?

Use a list instead and replace your foreach loop with a for loop:

@model IList<BlockedIPViewModel>

@using (Html.BeginForm()) 

    @for (var i = 0; i < Model.Count; i++) 
                @Html.HiddenFor(x => x[i].IP)           
                @Html.CheckBoxFor(x => x[i].Checked)
                @Html.DisplayFor(x => x[i].IP)
        <input type="submit" value="Unblock IPs" />

Alternatively you could use an editor template:

@model IEnumerable<BlockedIPViewModel>

@using (Html.BeginForm()) 
        <input type="submit" value="Unblock IPs" />

and then define the template ~/Views/Shared/EditorTemplates/BlockedIPViewModel.cshtml which will automatically be rendered for each element of the collection:

@model BlockedIPViewModel
        @Html.HiddenFor(x => x.IP)
        @Html.CheckBoxFor(x => x.Checked)
        @Html.DisplayFor(x => x.IP)

The reason you were getting null in your controller is because you didn't respect the naming convention for your input fields that the default model binder expects to successfully bind to a list. I invite you to read the following article.

Once you have read it, look at the generated HTML (and more specifically the names of the input fields) with my example and yours. Then compare and you will understand why yours doesn't work.

How do I specify the columns and rows of a multiline Editor-For in ASP.MVC?

Use TextAreaFor

@Html.TextAreaFor(model => model.Description, new { @class = "whatever-class", @cols = 80, @rows = 10 })

or use style for multi-line class.

You could also write EditorTemplate for this.

NVIDIA NVML Driver/library version mismatch

reboot. If the problem still exist:

sudo rmmod nvidia_drm
sudo rmmod nvidia_modeset
sudo rmmod nvidia

for cent/rhel

cd /boot
mv initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.bak
dracut -vf initramfs-$(uname -r).img $(uname -r)



for debian/ubuntu

update-initramfs -u

if problem exist persist

apt install -y dkms && dkms install -m nvidia -v 440.82

Change 440.82 to your actual version.

tip: get the Nvidia driver version:

ls /usr/src

you will find the Nvidia driver dir such as nvidia-440.82

also you can remove all Nvidia pkg and reinstall driver again

apt purge nvidia*
apt purge *cuda*

apt list -i |grep nvidia
apt list -i |grep cuda

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

Change it like this and it should work:

var key = item.Key.ToString();
IQueryable<entity> pages = from p in context.pages
                           where  p.Serial == key
                           select p;

The reason why the exception is not thrown in the line the LINQ query is declared but in the line of the foreach is the deferred execution feature, i.e. the LINQ query is not executed until you try to access the result. And this happens in the foreach and not earlier.

Unable to locate an executable at "/usr/bin/java/bin/java" (-1)

JAVA_HOME is not the name of the java executable. But of the directory, java was installed in. The executable should be $JAVA_HOME/bin/java.

The which command is not helpful for you there. It will not give you the java home, but most likely this is just a wrapper or symlink to java installed in a very different directory.

Angularjs how to upload multipart form data and a file?

First of all

  1. You don't need any special changes in the structure. I mean: html input tags.

<input accept="image/*" name="file" ng-value="fileToUpload"_x000D_
       value="{{fileToUpload}}" file-model="fileToUpload"_x000D_
       set-file-data="fileToUpload = value;" _x000D_
       type="file" id="my_file" />

1.2 create own directive,

.directive("fileModel",function() {_x000D_
 return {_x000D_
  restrict: 'EA',_x000D_
  scope: {_x000D_
   setFileData: "&"_x000D_
  link: function(scope, ele, attrs) {_x000D_
   ele.on('change', function() {_x000D_
    scope.$apply(function() {_x000D_
     var val = ele[0].files[0];_x000D_
     scope.setFileData({ value: val });_x000D_

  1. In module with $httpProvider add dependency like ( Accept, Content-Type etc) with multipart/form-data. (Suggestion would be, accept response in json format) For e.g:

$['Accept'] = 'application/json, text/javascript'; $['Content-Type'] = 'multipart/form-data; charset=utf-8';

  1. Then create separate function in controller to handle form submit call. like for e.g below code:

  2. In service function handle "responseType" param purposely so that server should not throw "byteerror".

  3. transformRequest, to modify request format with attached identity.

  4. withCredentials : false, for HTTP authentication information.

in controller:_x000D_
  // code this accordingly, so that your file object _x000D_
  // will be picked up in service call below._x000D_
  fileUpload.uploadFileToUrl(file); _x000D_
in service:_x000D_
  .service('fileUpload', ['$http', 'ajaxService',_x000D_
    function($http, ajaxService) {_x000D_
      this.uploadFileToUrl = function(data) {_x000D_
        var data = {}; //file object _x000D_
        var fd = new FormData();_x000D_
        fd.append('file', data.file);_x000D_
        $"endpoint server path to whom sending file", fd, {_x000D_
            withCredentials: false,_x000D_
            headers: {_x000D_
              'Content-Type': undefined_x000D_
            transformRequest: angular.identity,_x000D_
            params: {_x000D_
            responseType: "arraybuffer"_x000D_
          .then(function(response) {_x000D_
            var data =;_x000D_
            var status = response.status;_x000D_
            if (status == 200 || status == 202) //do whatever in success_x000D_
            else // handle error in  else if needed _x000D_
          .catch(function(error) {_x000D_
            // handle else calls_x000D_
<script src="//"></script>

WordPress - Check if user is logged in

Use the is_user_logged_in function:

if ( is_user_logged_in() ) {
   // your code for logged in user 
} else {
   // your code for logged out user 

How to change color in circular progress bar?

for me theme wasn't working with accentColor. But it did work with colorControlActivated

    <style name="Progressbar.White" parent="AppTheme">
        <item name="colorControlActivated">@color/white</item>


Detect if value is number in MySQL

Returns numeric rows

I found the solution with following query and works for me:

SELECT * FROM myTable WHERE col1 > 0;

This query return rows having only greater than zero number column that col1

Returns non numeric rows

if you want to check column not numeric try this one with the trick (!col1 > 0):

SELECT * FROM myTable WHERE !col1 > 0;

How to calculate distance from Wifi router using Signal Strength?

FSPL depends on two parameters: First is the frequency of radio signals;Second is the wireless transmission distance. The following formula can reflect the relationship between them.

FSPL (dB) = 20log10(d) + 20log10(f) + K

d = distance
f = frequency
K= constant that depends on the units used for d and f
If d is measured in kilometers, f in MHz, the formula is:

FSPL (dB) = 20log10(d)+ 20log10(f) + 32.44

From the Fade Margin equation, Free Space Path Loss can be computed with the following equation.

Free Space Path Loss=Tx Power-Tx Cable Loss+Tx Antenna Gain+Rx Antenna Gain - Rx Cable Loss - Rx Sensitivity - Fade Margin

With the above two Free Space Path Loss equations, we can find out the Distance in km.

Distance (km) = 10(Free Space Path Loss – 32.44 – 20log10(f))/20

The Fresnel Zone is the area around the visual line-of-sight that radio waves spread out into after they leave the antenna. You want a clear line of sight to maintain strength, especially for 2.4GHz wireless systems. This is because 2.4GHz waves are absorbed by water, like the water found in trees. The rule of thumb is that 60% of Fresnel Zone must be clear of obstacles. Typically, 20% Fresnel Zone blockage introduces little signal loss to the link. Beyond 40% blockage the signal loss will become significant.


d = distance [km]
f = frequency [GHz]
r = radius [m]

Source :

How to restart a windows service using Task Scheduler

Instead of using a bat file, you can simply create a Scheduled Task. Most of the time you define just one action. In this case, create two actions with the NET command. The first one to stop the service, the second one to start the service. Give them a STOP and START argument, followed by the service name.

In this example we restart the Printer Spooler service.

NET STOP "Print Spooler" 
NET START "Print Spooler"

enter image description here

enter image description here

Note: unfortunately NET RESTART <service name> does not exist.

How do I pull files from remote without overwriting local files?

Well, yes, and no...

I understand that you want your local copies to "override" what's in the remote, but, oh, man, if someone has modified the files in the remote repo in some different way, and you just ignore their changes and try to "force" your own changes without even looking at possible conflicts, well, I weep for you (and your coworkers) ;-)

That said, though, it's really easy to do the "right thing..."

Step 1:

git stash

in your local repo. That will save away your local updates into the stash, then revert your modified files back to their pre-edit state.

Step 2:

git pull

to get any modified versions. Now, hopefully, that won't get any new versions of the files you're worried about. If it doesn't, then the next step will work smoothly. If it does, then you've got some work to do, and you'll be glad you did.

Step 3:

git stash pop

That will merge your modified versions that you stashed away in Step 1 with the versions you just pulled in Step 2. If everything goes smoothly, then you'll be all set!

If, on the other hand, there were real conflicts between what you pulled in Step 2 and your modifications (due to someone else editing in the interim), you'll find out and be told to resolve them. Do it.

Things will work out much better this way - it will probably keep your changes without any real work on your part, while alerting you to serious, serious issues.

Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.10:test

Update the Maven project:


  1. Right-click on "project"
  2. Go to "Maven" >> "Update"
  3. Wait for all the changes to be applied
  4. Commit the changes (if code is on repo)
  5. Run

Rails - How to use a Helper Inside a Controller

One alternative missing from other answers is that you can go the other way around: define your method in your Controller, and then use helper_method to make it also available on views as, you know, a helper method.

For instance:

class ApplicationController < ActionController::Base


  def something_count
    # All other controllers that inherit from ApplicationController will be able to call `something_count`
  # All views will be able to call `something_count` as well
  helper_method :something_count 


set column width of a gridview in

<asp:GridView ID="GridView1" runat="server">
    <HeaderStyle Width="10%" />
    <RowStyle Width="10%" />
    <FooterStyle Width="10%" />
        <asp:BoundField HeaderText="Name" DataField="LastName" 
            HeaderStyle-Width="10%" ItemStyle-Width="10%"
            FooterStyle-Width="10%" />

How to print a int64_t type in C

//VC6.0 (386 & better)

    __int64 my_qw_var = 0x1234567890abcdef;

    __int32 v_dw_h;
    __int32 v_dw_l;

            mov eax,[dword ptr my_qw_var + 4]   //dwh
            mov [dword ptr v_dw_h],eax

            mov eax,[dword ptr my_qw_var]   //dwl
            mov [dword ptr v_dw_l],eax

        //Oops 0.8 format
    printf("val = 0x%0.8x%0.8x\n", (__int32)v_dw_h, (__int32)v_dw_l);


How to return value from an asynchronous callback function?

If you happen to be using jQuery, you might want to give this a shot:

It allows you to defer the execution of your callback function until the ajax request (or any async operation) is completed. This can also be used to call a callback once several ajax requests have all completed.

Web API Put Request generates an Http 405 Method Not Allowed error

In my case the error 405 was invoked by static handler due to route ("api/images") conflicting with the folder of the same name ("~/images").

How to automatically reload a page after a given period of inactivity

With on page confirmation text instead of alert

Since this is another method to auto load if inactive I give it a second answer. This one is more simple and easier to understand.

With reload confirmation on the page

<script language="javaScript" type="text/javascript">
var autoCloseTimer;
var timeoutObject;
var timePeriod = 5100; // 5,1 seconds
var warnPeriod = 5000; // 5 seconds
// Warning period should always be a bit shorter then time period

function promptForClose() { = 'block';
autoCloseTimer = setTimeout("definitelyClose()", warnPeriod);

function autoClose() { = 'block'; //shows message on page
autoCloseTimer = setTimeout("definitelyClose()", timePeriod); //starts countdown to closure

function cancelClose() {
clearTimeout(autoCloseTimer); //stops auto-close timer = 'none'; //hides message

function resetTimeout() {
clearTimeout(timeoutObject); //stops timer
timeoutObject = setTimeout("promptForClose()", timePeriod); //restarts timer from 0

function definitelyClose() {

// If you use want targeted reload: parent.Iframe0.location.href = ""
// or  this:'', '_self');

// of for the same page reload use:;
// or;, '_self');;

Confirmation box when using with on page confirmation

<div class="leftcolNon">
<div id='autoCloseDiv' style="display:none">
<b>Inactivity warning!</b><br />
This page will Reloads automatically unless you hit 'Cancel.'</p>
<input type='button' value='Load' onclick='definitelyClose();' />
<input type='button' value='Cancel' onclick='cancelClose();' />

Body codes for both are the SAME

<body onmousedown="resetTimeout();" onmouseup="resetTimeout();" onmousemove="resetTimeout();" onkeydown="resetTimeout();" onload="timeoutObject=setTimeout('promptForClose()',timePeriod);">

NOTE: If you do not want to have the on page confirmation, use Without confirmation

<script language="javaScript" type="text/javascript">
var autoCloseTimer;
var timeoutObject;
var timePeriod = 5000; // 5 seconds

function resetTimeout() {
clearTimeout(timeoutObject); //stops timer
timeoutObject = setTimeout("definitelyClose()", timePeriod); //restarts timer from 0

function definitelyClose() {

// If you use want targeted reload: parent.Iframe0.location.href = ""
// or  this:'', '_self');

// of for the same page reload use:;
// or;, '_self');;

Cannot get a text value from a numeric cell “Poi”

use the code
before reading the string value, Which can help you.
I am using POI version 3.17 Beta1 version, sure the version compatibility also..

SQL Update Multiple Fields FROM via a SELECT Statement

you can use update from...

something like:

update shipment set.... from shipment inner join ProfilerTest.dbo.BookingDetails on ...

Why does JSON.parse fail with the empty string?

For a valid JSON string at least a "{}" is required. See more at the

filtering NSArray into a new NSArray in Objective-C

The Best and easy Way is to create this method And Pass Array And Value:

- (NSArray *) filter:(NSArray *)array where:(NSString *)key is:(id)value{
    NSMutableArray *temArr=[[NSMutableArray alloc] init];
    for(NSDictionary *dic in self)
        if([dic[key] isEqual:value])
            [temArr addObject:dic];
    return temArr;

How to get index of object by its property in JavaScript?

Using underscore:

var index = _.indexOf(_.pluck(item , 'name'), 'Nick');

How do I find files that do not contain a given string pattern?

I had good luck with

grep -H -E -o -c "foo" */*/*.ext | grep ext:0

My attempts with grep -v just gave me all the lines without "foo".

Implicit function declarations in C

To complete the picture, since -Werror might considered too "invasive",
for gcc (and llvm) a more precise solution is to transform just this warning in an error, using the option:


See Make one gcc warning an error?

Regarding general use of -Werror: Of course, having warningless code is recommendable, but in some stage of development it might slow down the prototyping.

How to use Git for Unity3D source control?

The main things to remember when using git for unity-3d source code version control:

(A) DO NOT check-in the Library folder. I have made this mistake multiple times in past and have suffered for it! Delete OR move out library folder before adding your project / files into git.

(B) Use "Visible Meta Files" - for newest unity versions - 5.3.4 and above this happens by default. For some of the earlier versions you need to change the settings under: Edit-> Project Settings-> Version Control

(C) Use a .gitignore file for Unity- to make sure sanity is maintained and files are not unnecessarily added- if on android / tizen - add rules to exclude APK and TPK files from being added to repository. Google around for a .gitignore file for unity OR else use this model .gitignore for Unity provided by GitHub:

(D) Make sure the .gitignore file is added to the repository as the first file added - because in past I personally have missed adding .gitignore file. Have many thoughts in hindsight on why this happened- but nowadays I just copy and add .gitignore file as first step of setting up repository.

So... to make a Unity project ready for git, do the following:

(1) Go to project folder

(2) Type git init .

(3) Copy the .gitignore file: On MacOS: cp ~/Downloads/.gitignore On Windows: copy c:\Users[yourusername]\Downloads.gitignore .

(4) git add .gitignore

(5) git add *

Hope this helps... all the best!

How to load an external webpage into a div of a html page

Using simple html,

    <object type="text/html" data="" width="800px" height="600px" style="overflow:auto;border:5px ridge blue">

Or jquery,

            .html('<object data="http://your-website-domain"/>');


How to stop docker under Linux

The output of ps aux looks like you did not start docker through systemd/systemctl.

It looks like you started it with:

sudo dockerd -H gridsim1103:2376

When you try to stop it with systemctl, nothing should happen as the resulting dockerd process is not controlled by systemd. So the behavior you see is expected.

The correct way to start docker is to use systemd/systemctl:

systemctl enable docker
systemctl start docker

After this, docker should start on system start.

EDIT: As you already have the docker process running, simply kill it by pressing CTRL+C on the terminal you started it. Or send a kill signal to the process.

WPF Button with Image

<Button x:Name="myBtn_DetailsTab_Save" FlowDirection="LeftToRight"  HorizontalAlignment="Left" Margin="835,544,0,0" VerticalAlignment="Top"  Width="143" Height="53" BorderBrush="#FF0F6287" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" FontFamily="B Titr" FontSize="15" FontWeight="Bold" BorderThickness="2" Click="myBtn_DetailsTab_Save_Click">
    <StackPanel HorizontalAlignment="Stretch" Background="#FF1FB3F5" Cursor="Hand" >
        <Image HorizontalAlignment="Left"  Source="image/bg/Save.png" Height="36" Width="124" />
        <TextBlock HorizontalAlignment="Center" Width="84" Height="22" VerticalAlignment="Top" Margin="0,-31,-58,0" Text="??? ?????" />

How to detect DataGridView CheckBox event change?

I use DataGridView with VirtualMode=true and only this option worked for me (when both the mouse and the space bar are working, including repeated space clicks):

private void doublesGridView_CurrentCellDirtyStateChanged(object sender, EventArgs e)
   var data_grid = (DataGridView)sender;
   if (data_grid.CurrentCell.IsInEditMode && data_grid.IsCurrentCellDirty) {

private void doublesGridView_CellContentClick(object sender, DataGridViewCellEventArgs e)
   if (e.ColumnIndex == CHECKED_COLUMN_NUM && e.RowIndex >= 0 && e.RowIndex < view_objects.Count) { // view_objects - pseudocode   
     view_objects[e.RowIndex].marked = !view_objects[e.RowIndex].marked;        // Invert the state of the displayed object

Javascript Array.sort implementation?

I think that would depend on what browser implementation you are refering to.

Every browser type has it's own javascript engine implementation, so it depends. You could check the sourcecode repos for Mozilla and Webkit/Khtml for different implementations.

IE is closed source however, so you may have to ask somebody at microsoft.

Get pixel's RGB using PIL

Yes, this way:

im ='image.gif')
rgb_im = im.convert('RGB')
r, g, b = rgb_im.getpixel((1, 1))

print(r, g, b)
(65, 100, 137)

The reason you were getting a single value before with pix[1, 1] is because GIF pixels refer to one of the 256 values in the GIF color palette.

See also this SO post: Python and PIL pixel values different for GIF and JPEG and this PIL Reference page contains more information on the convert() function.

By the way, your code would work just fine for .jpg images.

How to turn on line numbers in IDLE?

As @StahlRat already answered. I would like to add another method for it. There is extension pack for Python Default idle editor Python Extensions Package.

What is the difference between for and foreach?

Difference Between For and For Each Loop in C#

  1. For Loops executes a block of code until an expression returns false while ForEach loop executed a block of code through the items in object collections.

  2. For loop can execute with object collections or without any object collections while ForEach loop can execute with object collections only.

  3. The for loop is a normal loop construct which can be used for multiple purposes where as foreach is designed to work only on Collections or IEnumerables object.

Most efficient way to concatenate strings in JavaScript?

I have no comment on the concatenation itself, but I'd like to point out that @Jakub Hampl's suggestion:

For building strings in the DOM, in some cases it might be better to iteratively add to the DOM, rather then add a huge string at once.

is wrong, because it's based on a flawed test. That test never actually appends into the DOM.

This fixed test shows that creating the string all at once before rendering it is much, MUCH faster. It's not even a contest.

(Sorry this is a separate answer, but I don't have enough rep to comment on answers yet.)

How to pass values arguments to function in Bootstrap


$(document).ready(function() {
    $('#createFormId').on('', function(event) {

Convert unix time to readable date in pandas dataframe

Alternatively, by changing a line of the above code:

# = d: datetime.strptime(d, "%Y-%m-%d")) = d: datetime.datetime.fromtimestamp(int(d)).strftime('%Y-%m-%d'))

It should also work.

Is there a portable way to get the current username in Python?

Combined pwd and getpass approach, based on other answers:

  import pwd
except ImportError:
  import getpass
  pwd = None

def current_user():
  if pwd:
    return pwd.getpwuid(os.geteuid()).pw_name
    return getpass.getuser()

jQuery Refresh/Reload Page if Ajax Success after time

$.ajax("youurl", function(data){
    if (data.success == true)
    setTimeout(function(){window.location = window.location}, 5000); 

ios app maximum memory budget

- (float)__getMemoryUsedPer1
    struct mach_task_basic_info info;
    mach_msg_type_number_t size = MACH_TASK_BASIC_INFO;
    kern_return_t kerr = task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&info, &size);
    if (kerr == KERN_SUCCESS)
        float used_bytes = info.resident_size;
        float total_bytes = [NSProcessInfo processInfo].physicalMemory;
        //NSLog(@"Used: %f MB out of %f MB (%f%%)", used_bytes / 1024.0f / 1024.0f, total_bytes / 1024.0f / 1024.0f, used_bytes * 100.0f / total_bytes);
        return used_bytes / total_bytes;
    return 1;

If one will use TASK_BASIC_INFO_COUNT instead of MACH_TASK_BASIC_INFO, you will get


do-while loop in R

See ?Control or the R Language Definition:

> y=0
> while(y <5){ print( y<-y+1) }
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5

So do_while does not exist as a separate construct in R, but you can fake it with:

repeat( { expressions}; if (! end_cond_expr ) {break} )

If you want to see the help page you cannot type ?while or ?repeat at the console but rather need to use ?'repeat' or ?'while'. All the "control-constructs" including if are on the same page and all need character quoting after the "?" so the interpreter doesn't see them as incomplete code and give you a continuation "+".

How to get list of dates between two dates in mysql select query


select * from 
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where selected_date between '2012-02-10' and '2012-02-15'

-for date ranges up to nearly 300 years in the future.

[Corrected following a suggested edit by UrvishAtSynapse.]

Check if string has space in between (or anywhere)

This functions should help you...

bool isThereSpace(String s){
    return s.Contains(" ");

Hot to get all form elements values using jQuery?

If you want to use $(formName).serializeArray() or $(formName).serialize(), you must add name='inputName' on your input element. or will not work!

putting a php variable in a HTML form value

You can do it like this,

<input type="text" name="name" value="<?php echo $name;?>" />

But seen as you've taken it straight from user input, you want to sanitize it first so that nothing nasty is put into the output of your page.

<input type="text" name="name" value="<?php echo htmlspecialchars($name);?>" />

Ignore files that have already been committed to a Git repository

Thanks to your answer, I was able to write this little one-liner to improve it. I ran it on my .gitignore and repo, and had no issues, but if anybody sees any glaring problems, please comment. This should git rm -r --cached from .gitignore:

cat $(git rev-parse --show-toplevel)/.gitIgnore | sed "s/\/$//" | grep -v "^#" | xargs -L 1 -I {} find $(git rev-parse --show-toplevel) -name "{}" | xargs -L 1 git rm -r --cached

Note that you'll get a lot of fatal: pathspec '<pathspec>' did not match any files. That's just for the files which haven't been modified.

startForeground fail after upgrade to Android 8.1

Works properly on Andorid 8.1:

Updated sample (without any deprecated code):

public NotificationBattery(Context context) {
    this.mCtx = context;

    mBuilder = new NotificationCompat.Builder(context, CHANNEL_ID)
            .setWhen(System.currentTimeMillis() + 500)

    mRemoteViews = new RemoteViews(context.getPackageName(), R.layout.notification_view_battery);



    mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

    if (AesPrefs.getBooleanRes(R.string.SHOW_BATTERY_NOTIFICATION, true)) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, context.getString(R.string.notification_title_battery),
            channel.setSound(null, null);
    } else {

Old snipped (it's a different app - not related to the code above):

public int onStartCommand(Intent intent, int flags, final int startId) {
    Log.d(TAG, "onStartCommand");

    String CHANNEL_ONE_ID = "";
    String CHANNEL_ONE_NAME = "Channel One";
    NotificationChannel notificationChannel = null;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
        notificationChannel = new NotificationChannel(CHANNEL_ONE_ID,
        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

    Bitmap icon = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
    Notification notification = new Notification.Builder(getApplicationContext())

    Intent notificationIntent = new Intent(getApplicationContext(), MainActivity.class);
    notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
    notification.contentIntent = PendingIntent.getActivity(getApplicationContext(), 0, notificationIntent, 0);

    startForeground(START_FOREGROUND_ID, notification);

    return START_STICKY;

Why have header files and .cpp files?

Because C, where the concept originated, is 30 years old, and back then, it was the only viable way to link together code from multiple files.

Today, it's an awful hack which totally destroys compilation time in C++, causes countless needless dependencies (because class definitions in a header file expose too much information about the implementation), and so on.

MSBUILD : error MSB1008: Only one project can be specified

If you are using Any CPU you may need to put it in single quotes.

Certainly when running in a Dockerfile, I had to use single quotes:

# Fails. Gives: MSBUILD : error MSB1008: Only one project can be specified.
RUN msbuild ConsoleAppFw451.sln /p:Configuration=Debug /p:Platform="Any CPU" 

# Passes. Gives: Successfully built 40163c3e0121
RUN msbuild ConsoleAppFw451.sln /p:Configuration=Debug /p:Platform='Any CPU' 

%Like% Query in spring JpaRepository

You can have one alternative of using placeholders as:

@Query("Select c from Registration c where LIKE  %?1%")
List<Registration> findPlaceContainingKeywordAnywhere(String place);

Floating divs in Bootstrap layout

From all I have read you cannot do exactly what you want without javascript. If you float left before text

<div style="float:left;">widget</div> here is some CONTENT, etc.

Your content wraps as expected. But your widget is in the top left. If you instead put the float after the content

here is some CONTENT, etc. <div style="float:left;">widget</div>

Then your content will wrap the last line to the right of the widget if the last line of content can fit to the right of the widget, otherwise no wrapping is done. To make borders and backgrounds actually include the floated area in the previous example, most people add:

here is some CONTENT, etc. <div style="float:left;">widget</div><div style="clear:both;"></div>

In your question you are using bootstrap which just adds row-fluid::after { content: ""} which resolves the border/background issue.

Moving your content up will give you the one line wrap :

  <div class="container-fluid">
  <div class="row-fluid">
    <div class="offset1 span8 pull-right">
    ... Widget 1...
    .... a lot of content ....
    <div class="span8" style="margin-left: 0;">
    ... Widget 2...



Create a circular button in BS3

If you have downloaded these files locally then you can change following classes in bootstrap-social.css, just added border-radius: 50%;

   padding-left:0;padding-right:0; border-radius: 50%; }

And here is teh HTML

<a class="btn btn-social-icon btn-lg btn-twitter" >
   <i class="fa fa-twitter"></i>
<a class=" btn btn-social-icon btn-lg btn-facebook">
   <i class="fa fa-facebook sbg-facebook"></i>
<a class="btn btn-social-icon btn-lg btn-google-plus">
   <i class="fa fa-google-plus"></i>

It works smooth for me.

how to get current datetime in SQL?

I always just use NOW():

INSERT INTO table (lastModifiedTime) VALUES (NOW())

How to add New Column with Value to the Existing DataTable?

Add the column and update all rows in the DataTable, for example:

DataTable tbl = new DataTable();
tbl.Columns.Add(new DataColumn("ID", typeof(Int32)));
tbl.Columns.Add(new DataColumn("Name", typeof(string)));
for (Int32 i = 1; i <= 10; i++) {
    DataRow row = tbl.NewRow();
    row["ID"] = i;
    row["Name"] = i + ". row";
DataColumn newCol = new DataColumn("NewColumn", typeof(string));
newCol.AllowDBNull = true;
foreach (DataRow row in tbl.Rows) {
    row["NewColumn"] = "You DropDownList value";
//if you don't want to allow null-values'
newCol.AllowDBNull = false;

'Field required a bean of type that could not be found.' error spring restful API using mongodb

you have to import spring-boot-starter-data-jpa as dependeny if you use spring boot

git: fatal: I don't handle protocol '??http'

In Android Studio:

I removed git clone and just retain the url only and it worked!!

Python int to binary string?

Calculator with all neccessary functions for DEC,BIN,HEX: (made and tested with Python 3.5)

You can change the input test numbers and get the converted ones.


def dec2bin(d):
    # dec -> bin
    b = bin(d)
    return b

def dec2hex(d):
    # dec -> hex
    h = hex(d)
    return h

def bin2dec(b):
    # bin -> dec
    d = eval(bin_numb)
    return d,bin_numb

def bin2hex(b):
    # bin -> hex
    h = hex(b)
    return h

def hex2dec(h):
    # hex -> dec
    d = int(h)
    return d

def hex2bin(h):
    # hex -> bin
    b = bin(h)
    return b

numb_dec = 99
numb_bin = 0b0111 
numb_hex = 0xFF

res_dec2bin = dec2bin(numb_dec)
res_dec2hex = dec2hex(numb_dec)

res_bin2dec,bin_numb = bin2dec(numb_bin)
res_bin2hex = bin2hex(numb_bin)

res_hex2dec = hex2dec(numb_hex)
res_hex2bin = hex2bin(numb_hex)

print('------- DECIMAL to BIN / HEX -------\n')
print('decimal:',numb_dec,'\nbin:    ',res_dec2bin,'\nhex:    ',res_dec2hex,'\n')

print('------- BINARY to DEC / HEX -------\n')
print('binary: ',bin_numb,'\ndec:    ',numb_bin,'\nhex:    ',res_bin2hex,'\n')

print('----- HEXADECIMAL to BIN / HEX -----\n')
print('hexadec:',hex(numb_hex),'\nbin:    ',res_hex2bin,'\ndec:    ',res_hex2dec,'\n')

Why does PEP-8 specify a maximum line length of 79 characters?

Printing a monospaced font at default sizes is (on A4 paper) 80 columns by 66 lines.

Divide a number by 3 without using *, /, +, -, % operators

Quite amused none answered with a generic division:

/* For the given integer find the position of MSB */
int find_msb_loc(unsigned int n)
    if (n == 0)
        return 0;

    int loc = sizeof(n)  * 8 - 1;
    while (!(n & (1 << loc)))
    return loc;

/* Assume both a and b to be positive, return a/b */
int divide_bitwise(const unsigned int a, const unsigned int b)
    int int_size = sizeof(unsigned int) * 8;
    int b_msb_loc = find_msb_loc(b);

    int d = 0; // dividend
    int r = 0; // reminder
    int t_a = a;
    int t_a_msb_loc = find_msb_loc(t_a);
    int t_b = b << (t_a_msb_loc - b_msb_loc);

    int i;
    for(i = t_a_msb_loc; i >= b_msb_loc; i--)  {
        if (t_a > t_b) {
            d = (d << 1) | 0x1;
            t_a -= t_b; // Not a bitwise operatiion
            t_b = t_b >> 1;
        else if (t_a == t_b) {
            d = (d << 1) | 0x1;
            t_a = 0;
        else { // t_a < t_b
            d = d << 1;
            t_b = t_b >> 1;

    r = t_a;
    printf("==> %d %d\n", d, r);
    return d;

The bitwise addition has already been given in one of the answers so skipping it.

Why do you need ./ (dot-slash) before executable or script name to run it in bash?

This question already has some awesome answers, but I wanted to add that, if your executable is on the PATH, and you get very different outputs when you run


to the ones you get if you run


(let's say you run into error messages with the one and not the other), then the problem could be that you have two different versions of the executable on your machine: one on the path, and the other not.

Check this by running

which executable


whereis executable

It fixed my issues...I had three versions of the executable, only one of which was compiled correctly for the environment.

See last changes in svn

You could use CommitMonitor. This little tool uses very little RAM and notifies you of all the commits you've missed.

How can I create an executable JAR with dependencies using Maven?

There are millions of answers already, I wanted to add you don't need <mainClass> if you don't need to add entryPoint to your application. For example APIs may not have necessarily have main method.

maven plugin config



mvn clean compile assembly:single


ll target/
total 35100
drwxrwx--- 1 root vboxsf     4096 Sep 29 16:25 ./
drwxrwx--- 1 root vboxsf     4096 Sep 29 16:25 ../
drwxrwx--- 1 root vboxsf        0 Sep 29 16:08 archive-tmp/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 classes/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 generated-sources/
drwxrwx--- 1 root vboxsf        0 Sep 29 16:25 generated-test-sources/
-rwxrwx--- 1 root vboxsf 35929841 Sep 29 16:10 log-enrichment-jar-with-dependencies.jar*
drwxrwx--- 1 root vboxsf        0 Sep 29 16:08 maven-status/

How to listen for changes to a MongoDB collection?

Actually, instead of watching output, why you dont get notice when something new is inserted by using middle-ware that was provided by mongoose schema

You can catch the event of insert a new document and do something after this insertion done

Ant task to run an Ant target only if a file exists?

This might make a little more sense from a coding perspective (available with ant-contrib:

<target name="someTarget">
        <available file="abc.txt"/>

How to compare two dates to find time difference in SQL Server 2005, date manipulation

Try this in Sql Server

      start_date as firstdate,end_date as seconddate
       ,cast(datediff(MI,start_date,end_date)as decimal(10,3)) as minutediff
      ,cast(cast(cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60) as int ) as varchar(10)) + ' ' + 'Days' + ' ' 
      + cast(cast((cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60) - 
        floor(cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60)) ) * 24 as int) as varchar(10)) + ':' 

     + cast( cast(((cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60) 
      - floor(cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60)))*24
        cast(floor((cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60) 
      - floor(cast(datediff(MI,start_date,end_date)as decimal(10,3)) / (24*60)))*24) as decimal)) * 60 as int) as varchar(10))

    FROM [AdventureWorks2012].dbo.learndate

JavaScript operator similar to SQL "like"

No, there isn't any.

The list of comparison operators are listed here.

Comparison Operators

For your requirement the best option would be regular expressions.

Python: "TypeError: __str__ returned non-string" but still prints to output?

I Had the same problem, in my case, was because i was returned a digit:

def __str__(self):
    return self.code

str is waiting for a str, not another.

now work good with:

def __str__(self):

where name is a STRING.

Entity Framework rollback and remove bad migration

You have 2 options:

  • You can take the Down from the bad migration and put it in a new migration (you will also need to make the subsequent changes to the model). This is effectively rolling up to a better version.

    I use this option on things that have gone to multiple environments.

  • The other option is to actually run Update-Database –TargetMigration: TheLastGoodMigration against your deployed database and then delete the migration from your solution. This is kinda the hulk smash alternative and requires this to be performed against any database deployed with the bad version.

    Note: to rescaffold the migration you can use Add-Migration [existingname] -Force. This will however overwrite your existing migration, so be sure to do this only if you have removed the existing migration from the database. This does the same thing as deleting the existing migration file and running add-migration

    I use this option while developing.

Getting vertical gridlines to appear in line plot in matplotlib

For only horizontal lines

ax = plt.axes()        
ax.yaxis.grid() # horizontal lines

This worked

How can I extract substrings from a string in Perl?


(\S*)    picks up anything which is NOT whitespace
\s*      0 or more whitespace characters
\(       a literal open parenthesis
(.*?)    anything, non-greedy so stops on first occurrence of...
\)       a literal close parenthesis
\s*      0 or more whitespace characters
(\*?)    0 or 1 occurances of literal *

How to set maximum height for table-cell?

I don't think that the accepted answer actually fully solves the problem. You wanted to have a vertical-align: middle on the table-cells content. But when you add a div inside the table-cell and give it a height the content of that inner DIV will be at the top. Check this jsfiddle. The overflow:hidden; works fine, but if you shorten the content so that it's only one line, this line won't be centered vertically

The solution is not to add a DIV inside the table-cell but rather outside. Here's the Code:

/* some wrapper */_x000D_
div.d0 {_x000D_
    background: grey;_x000D_
    height: 200px;_x000D_
div.table {_x000D_
    margin: 0 auto; /* just cosmetics */_x000D_
    width: 150px;_x000D_
    height: 150px;_x000D_
    background: #eee;_x000D_
    display: table;_x000D_
div.tablecell {_x000D_
    display: table-cell;_x000D_
    vertical-align: middle;_x000D_
    height: 100%;_x000D_
    width: 100%;_x000D_
    background: #aaa;_x000D_
div.outer-div {_x000D_
    height: 150px;_x000D_
    overflow: hidden;_x000D_
<div class="d0">_x000D_
    <div class="outer-div">_x000D_
        <div class="table">_x000D_
            <div class="tablecell">_x000D_
                Lorem ipsum _x000D_
                <!--dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren,-->_x000D_

How to disable SSL certificate checking with Spring RestTemplate?

I wish I still had a link to the source that lead me in this direction, but this is the code that ended up working for me. By looking over the JavaDoc for X509TrustManager it looks like the way the TrustManagers work is by returning nothing on successful validation, otherwise throwing an exception. Thus, with a null implementation, it is treated as a successful validation. Then you remove all other implementations.


public final class SSLUtil{

    private static final TrustManager[] UNQUESTIONING_TRUST_MANAGER = new TrustManager[]{
            new X509TrustManager() {
                public[] getAcceptedIssuers(){
                    return null;
                public void checkClientTrusted( X509Certificate[] certs, String authType ){}
                public void checkServerTrusted( X509Certificate[] certs, String authType ){}

    public  static void turnOffSslChecking() throws NoSuchAlgorithmException, KeyManagementException {
        // Install the all-trusting trust manager
        final SSLContext sc = SSLContext.getInstance("SSL");
        sc.init( null, UNQUESTIONING_TRUST_MANAGER, null );

    public static void turnOnSslChecking() throws KeyManagementException, NoSuchAlgorithmException {
        // Return it to the initial state (discovered by reflection, now hardcoded)
        SSLContext.getInstance("SSL").init( null, null, null );

    private SSLUtil(){
        throw new UnsupportedOperationException( "Do not instantiate libraries.");

How to use UIVisualEffectView to Blur Image?

I prefer creating Visual Effects via Storyboard - no code used for creating or maintaining UI Elements. It gives me full landscape support, too. I have made a little demo of using UIVisualEffects with Blur and also Vibrancy.

Demo on Github

How can VBA connect to MySQL database in Excel?

Ranjit's code caused the same error message as reported by Tin, but worked after updating with the ODBC driver I'm running. Check the Drivers tab in the ODBC Data Source Administrator. Mine said "MySQL ODBC 5.3 Unicode Driver" so I updated accordingly.

Convert Year/Month/Day to Day of Year in Python

I want to present performance of different approaches, on Python 3.4, Linux x64. Excerpt from line profiler:

      Line #      Hits         Time  Per Hit   % Time  Line Contents
         823      1508        11334      7.5     41.6          yday = int(period_end.strftime('%j'))
         824      1508         2492      1.7      9.1          yday = period_end.toordinal() - date(period_end.year, 1, 1).toordinal() + 1
         825      1508         1852      1.2      6.8          yday = (period_end - date(period_end.year, 1, 1)).days + 1
         826      1508         5078      3.4     18.6          yday = period_end.timetuple().tm_yday

So most efficient is

yday = (period_end - date(period_end.year, 1, 1)).days

Proper way to use **kwargs in Python

If you want to combine this with *args you have to keep *args and **kwargs at the end of the definition.


def method(foo, bar=None, *args, **kwargs):
    do_something_with(foo, bar)
    some_other_function(*args, **kwargs)

text-align: right on <select> or <option>

The best solution for me was to make

select {
    direction: rtl;

and then

option {
    direction: ltr;

again. So there is no change in how the text is read in a screen reader or and no formatting-problem.

Drop primary key using script in SQL Server database

The answer I got is that variables and subqueries will not work and we have to user dynamic SQL script. The following works:

SET @SQL = 'ALTER TABLE dbo.Student DROP CONSTRAINT |ConstraintName| '

SET @SQL = REPLACE(@SQL, '|ConstraintName|', ( SELECT   name
                                               FROM     sysobjects
                                               WHERE    xtype = 'PK'
                                                        AND parent_obj =        OBJECT_ID('Student')))


JOIN queries vs multiple queries

This is way too vague to give you an answer relevant to your specific case. It depends on a lot of things. Jeff Atwood (founder of this site) actually wrote about this. For the most part, though, if you have the right indexes and you properly do your JOINs it is usually going to be faster to do 1 trip than several.

Sort a list of lists with a custom compare function

Also, your compare function is incorrect. It needs to return -1, 0, or 1, not a boolean as you have it. The correct compare function would be:

def compare(item1, item2):
    if fitness(item1) < fitness(item2):
        return -1
    elif fitness(item1) > fitness(item2):
        return 1
        return 0

# Calling

Git vs Team Foundation Server

I think, the statement

everyone hates it except me

makes any further discussion waste: when you keep using Git, they will blame you if anything goes wrong.

Apart from this, for me Git has two advantages over a centralized VCS that I appreciate most (as partly described by Rob Sobers):

  • automatic backup of the whole repo: everytime someone pulls from the central repo, he/she gets a full history of the changes. When one repo gets lost: don't worry, take one of those present on every workstation.
  • offline repo access: when I'm working at home (or in an airplane or train), I can see the full history of the project, every single checkin, without starting up my VPN connection to work and can work like I were at work: checkin, checkout, branch, anything.

But as I said: I think that you're fighting a lost battle: when everyone hates Git, don't use Git. It could help you more to know why they hate Git instead of trying them to convince them.

If they simply don't want it 'cause it's new to them and are not willing to learn something new: are you sure that you will do successful development with that staff?

Does really every single person hate Git or are they influenced by some opinion leaders? Find the leaders and ask them what's the problem. Convince them and you'll convince the rest of the team.

If you cannot convince the leaders: forget about using Git, take the TFS. Will make your life easier.

onclick or inline script isn't working in extension


This does not work, because Chrome forbids any kind of inline code in extensions via Content Security Policy.

Inline JavaScript will not be executed. This restriction bans both inline <script> blocks and inline event handlers (e.g. <button onclick="...">).

How to detect

If this is indeed the problem, Chrome would produce the following error in the console:

Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self' chrome-extension-resource:". Either the 'unsafe-inline' keyword, a hash ('sha256-...'), or a nonce ('nonce-...') is required to enable inline execution.

To access a popup's JavaScript console (which is useful for debug in general), right-click your extension's button and select "Inspect popup" from the context menu.

More information on debugging a popup is available here.

How to fix

One needs to remove all inline JavaScript. There is a guide in Chrome documentation.

Suppose the original looks like:

<a onclick="handler()">Click this</a> <!-- Bad -->

One needs to remove the onclick attribute and give the element a unique id:

<a id="click-this">Click this</a> <!-- Fixed -->

And then attach the listener from a script (which must be in a .js file, suppose popup.js):

// Pure JS:
document.addEventListener('DOMContentLoaded', function() {
  document.getElementById("click-this").addEventListener("click", handler);

// The handler also must go in a .js file
function handler() {
  /* ... */

Note the wrapping in a DOMContentLoaded event. This ensures that the element exists at the time of execution. Now add the script tag, for instance in the <head> of the document:

<script src="popup.js"></script>

Alternative if you're using jQuery:

// jQuery
$(document).ready(function() {

Relaxing the policy

Q: The error mentions ways to allow inline code. I don't want to / can't change my code, how do I enable inline scripts?

A: Despite what the error says, you cannot enable inline script:

There is no mechanism for relaxing the restriction against executing inline JavaScript. In particular, setting a script policy that includes 'unsafe-inline' will have no effect.

Update: Since Chrome 46, it's possible to whitelist specific inline code blocks:

As of Chrome 46, inline scripts can be whitelisted by specifying the base64-encoded hash of the source code in the policy. This hash must be prefixed by the used hash algorithm (sha256, sha384 or sha512). See Hash usage for <script> elements for an example.

However, I do not readily see a reason to use this, and it will not enable inline attributes like onclick="code".

MongoDB Data directory /data/db not found

MongoDB needs data directory to store data. Default path is /data/db

When you start MongoDB engine, it searches this directory which is missing in your case. Solution is create this directory and assign rwx permission to user.

If you want to change the path of your data directory then you should specify it while starting mongod server like,

mongod --dbpath /data/<path> --port <port no> 

This should help you start your mongod server with custom path and port.

How to include the reference of DocumentFormat.OpenXml.dll on Mono2.10?

Being new to this myself, here's what I did:

I'm using MS Visual Studio 2010 Pro.

  1. Download and install the OpenXML SDK
  2. Within my project in Visual Studio, select "Project" then "Add Reference"
  3. Select the "Browse" tab
  4. In the "Look in:" pull down, navigate to: C:\Program Files(x86)\Open XML SDK\V2.0\lib and select the "DocumentFormat.OpenXml.dll
  5. Hit OK
  6. In the "Solution Explorer" (on the right for me), the "References" folder now shows the DocumentFormat.OpenXML library.
  7. Right-click on it and select Properties
  8. In the Properties panel, change "Copy Local" to "True".

You should be off and running now using the DocumentFormat classes.

How to set editable true/false EditText in Android programmatically?

Try this it is working fine for me..

EditText.setFilters(new InputFilter[] {new InputFilter()
public CharSequence filter(CharSequence source, int start,
                            int end, Spanned dest, int dstart, int dend) 
return source.length() < 1 ? dest.subSequence(dstart, dend) : "";


How copy data from Excel to a table using Oracle SQL Developer

You may directly right-click on the table name - that also shows the "Import Data.." option.Then you can follow few simple steps & succeed.

Do anyone know how to import a new table with data from excel?

Running Windows batch file commands asynchronously

You can use the start command to spawn background processes without launching new windows:

start /b foo.exe

The new process will not be interruptable with CTRL-C; you can kill it only with CTRL-BREAK (or by closing the window, or via Task Manager.)

How to add Android Support Repository to Android Studio?

Instead of doing this:

compile ""

Do this:

compile '' 

Worked for me

Android: Creating a Circular TextView?

The typical solution is to define the shape and use it as background but as the number of digits varies it's no more a perfect circle, it looks like a rectangle with round edges or Oval. So I have developed this solution, it's working great. Hope it will help someone.

Circular Text View

Here is the code of custom TextView

import android.content.Context;
import android.util.AttributeSet;
import android.widget.TextView;

public class CircularTextView extends TextView
private float strokeWidth;
int strokeColor,solidColor;

public CircularTextView(Context context) {

public CircularTextView(Context context, AttributeSet attrs) {
    super(context, attrs);

public CircularTextView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);

public void draw(Canvas canvas) {

    Paint circlePaint = new Paint();

    Paint strokePaint = new Paint();

    int  h = this.getHeight();
    int  w = this.getWidth();

    int diameter = ((h > w) ? h : w);
    int radius = diameter/2;


    canvas.drawCircle(diameter / 2 , diameter / 2, radius, strokePaint);

    canvas.drawCircle(diameter / 2, diameter / 2, radius-strokeWidth, circlePaint);


public void setStrokeWidth(int dp)
    float scale = getContext().getResources().getDisplayMetrics().density;
    strokeWidth = dp*scale;


public void setStrokeColor(String color)
    strokeColor = Color.parseColor(color);

public void setSolidColor(String color)
    solidColor = Color.parseColor(color);


Then in your XML, give some padding and make sure its gravity is center


And you can set the stroke width


Counting array elements in Python

Before I saw this, I thought to myself, "I need to make a way to do this!"

for tempVar in arrayName: tempVar+=1

And then I thought, "There must be a simpler way to do this." and I was right.


Typescript empty object for a typed variable

If you declare an empty object literal and then assign values later on, then you can consider those values optional (may or may not be there), so just type them as optional with a question mark:

type User = {
    Username?: string;
    Email?: string;

How can I decrypt a password hash in PHP?

I need to decrypt a password. The password is crypted with password_hash function.

$password = 'examplepassword';
$crypted = password_hash($password, PASSWORD_DEFAULT);

Its not clear to me if you need password_verify, or you are trying to gain unauthorized access to the application or database. Other have talked about password_verify, so here's how you could gain unauthorized access. Its what bad guys often do when they try to gain access to a system.

First, create a list of plain text passwords. A plain text list can be found in a number of places due to the massive data breaches from companies like Adobe. Sort the list and then take the top 10,000 or 100,000 or so.

Second, create a list of digested passwords. Simply encrypt or hash the password. Based on your code above, it does not look like a salt is being used (or its a fixed salt). This makes the attack very easy.

Third, for each digested password in the list, perform a select in an attempt to find a user who is using the password:

$sql_script = 'select * from USERS where password="'.$digested_password.'"'

Fourth, profit.

So, rather than picking a user and trying to reverse their password, the bad guy picks a common password and tries to find a user who is using it. Odds are on the bad guy's side...

Because the bad guy does these things, it would behove you to not let users choose common passwords. In this case, take a look at ProCheck, EnFilter or Hyppocrates (et al). They are filtering libraries that reject bad passwords. ProCheck achieves very high compression, and can digest multi-million word password lists into a 30KB data file.