Programs & Examples On #Rsls

Runtime Shared Library, used in Adobe Flash Platform applications.

2D Euclidean vector rotations

Rotating a vector 90 degrees is particularily simple.

(x, y) rotated 90 degrees around (0, 0) is (-y, x).

If you want to rotate clockwise, you simply do it the other way around, getting (y, -x).

Python Error: unsupported operand type(s) for +: 'int' and 'NoneType'

When none of the if test in number_translator() evaluate to true, the function returns None. The error message is the consequence of that.

Whenever you see an error that include 'NoneType' that means that you have an operand or an object that is None when you were expecting something else.

Is it possible to set async:false to $.getJSON call

I don't think you can set that option there. You will have to use jQuery.ajax() with the appropriate parameters (basically getJSON just wraps that call into an easier API, as well).

XmlSerializer: remove unnecessary xsi and xsd namespaces

//Create our own namespaces for the output
XmlSerializerNamespaces ns = new XmlSerializerNamespaces();

//Add an empty namespace and empty value
ns.Add("", "");

//Create the serializer
XmlSerializer slz = new XmlSerializer(someType);

//Serialize the object with our own namespaces (notice the overload)
slz.Serialize(myXmlTextWriter, someObject, ns)

How to pass command-line arguments to a PowerShell ps1 file

You may not get "xuxu p1 p2 p3 p4" as it seems. But when you are in PowerShell and you set

PS > set-executionpolicy Unrestricted -scope currentuser

You can run those scripts like this:

./xuxu p1 p2 p3 p4


.\xuxu p1 p2 p3 p4


./xuxu.ps1 p1 p2 p3 p4

I hope that makes you a bit more comfortable with PowerShell.

cannot be cast to java.lang.Comparable

I faced a similar kind of issue while using a custom object as a key in Treemap. Whenever you are using a custom object as a key in hashmap then you override two function equals and hashcode, However if you are using ContainsKey method of Treemap on this object then you need to override CompareTo method as well otherwise you will be getting this error Someone using a custom object as a key in hashmap in kotlin should do like following

 data class CustomObjectKey(var key1:String = "" , var 
 key2:String = ""):Comparable<CustomObjectKey?>
override fun compareTo(other: CustomObjectKey?): Int {
    if(other == null)
        return -1
   // suppose you want to do comparison based on key 1 
    return this.key1.compareTo((other)key1)

override fun equals(other: Any?): Boolean {
    if(other == null)
        return false
    return this.key1 == (other as CustomObjectKey).key1

override fun hashCode(): Int {
    return this.key1.hashCode()

PYTHONPATH vs. sys.path

Along with the many other reasons mentioned already, you could also point outh that hard-coding


is brittle because it presumes the location of -- it will only work if is located in Project/package. It will break if a user decides to move/copy/symlink (almost) anywhere else.

How can I make a list of lists in R?

Using your example::

list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)

Use '[[' to retrieve an element of a list:

b = list_all[[1]]
[1] 1

[1] 2

[1] "list"

Compare two files report difference in python

You can add an conditional statement. If your array goes beyond index, then break and print the rest of the file.

Python datetime strptime() and strftime(): how to preserve the timezone information

Here is my answer in Python 2.7

Print current time with timezone

from datetime import datetime
import tzlocal  # pip install tzlocal

print"%Y-%m-%d %H:%M:%S %z")

Print current time with specific timezone

from datetime import datetime
import pytz # pip install pytz

print'Asia/Taipei')).strftime("%Y-%m-%d %H:%M:%S %z")

It will print something like

2017-08-10 20:46:24 +0800

JWT refresh token flow

Based in this implementation with Node.js of JWT with refresh token:

1) In this case they use a uid and it's not a JWT. When they refresh the token they send the refresh token and the user. If you implement it as a JWT, you don't need to send the user, because it would inside the JWT.

2) They implement this in a separated document (table). It has sense to me because a user can be logged in in different client applications and it could have a refresh token by app. If the user lose a device with one app installed, the refresh token of that device could be invalidated without affecting the other logged in devices.

3) In this implementation it response to the log in method with both, access token and refresh token. It seams correct to me.

Check if AJAX response data is empty/blank/null/undefined/0

    url: "<?php echo admin_url('admin-ajax.php'); ?>",
    data: associated_buildsorprojects_form,
        // do console.log(data);
        // you'll find that what exactly inside data 
        // I do not prefer alter(data); now because, it does not 
        // completes requirement all the time 
        // After that you can easily put if condition that you do not want like
        // if(data != '')
        // if(data == null)
        // or whatever you want 
    error: function(errorThrown){
        alert("There is an error with AJAX!");

How can I do SELECT UNIQUE with LINQ?

Using query comprehension syntax you could achieve the orderby as follows:

var uniqueColors = (from dbo in database.MainTable
                    where dbo.Property
                    orderby dbo.Color.Name ascending
                    select dbo.Color.Name).Distinct();

iPhone Navigation Bar Title text color

Based on Steven Fisher's answer I wrote this piece of code:

- (void)setTitle:(NSString *)title
    [super setTitle:title];
    UILabel *titleView = (UILabel *)self.navigationItem.titleView;
    if (!titleView) {
        titleView = [[UILabel alloc] initWithFrame:CGRectZero];
        titleView.backgroundColor = [UIColor clearColor];
        titleView.font = [UIFont boldSystemFontOfSize:20.0];
        titleView.shadowColor = [UIColor colorWithWhite:0.0 alpha:0.5];

        titleView.textColor = [UIColor yellowColor]; // Change to desired color

        self.navigationItem.titleView = titleView;
        [titleView release];
    titleView.text = title;
    [titleView sizeToFit];

The advantage of this code, besides dealing with the frame properly, is that if you change the title of your controller the custom title view will also get updated. No need to update it manually.

Another big advantage is that it makes it really simple to enable custom title color. All you need to do is to add this method to the controller.

Countdown timer using Moment js

I thought I'd throw this out there too (no plugins). It counts down for 10 seconds into the future.

    var countDownDate = moment().add(10, 'seconds');_x000D_
      var x = setInterval(function() {_x000D_
        diff = countDownDate.diff(moment());_x000D_
        if (diff <= 0) {_x000D_
           // If the count down is finished, write some text _x000D_
        } else_x000D_
      }, 1000);
<script src=""></script>_x000D_
<script src=""></script>_x000D_
<div class="countdown"></div>

Random float number generation

#include <cstdint>
#include <cstdlib>
#include <ctime>

using namespace std;

/* single precision float offers 24bit worth of linear distance from 1.0f to 0.0f */
float getval() {
    /* rand() has min 16bit, but we need a 24bit random number. */
    uint_least32_t r = (rand() & 0xffff) + ((rand() & 0x00ff) << 16);
    /* 5.9604645E-8 is (1f - 0.99999994f), 0.99999994f is the first value less than 1f. */
    return (double)r * 5.9604645E-8;

int main()

I couldn't post two answers, so here is the second solution. log2 random numbers, massive bias towards 0.0f but it's truly a random float 1.0f to 0.0f.

#include <cstdint>
#include <cstdlib>
#include <ctime>

using namespace std;

float getval () {
    union UNION {
        uint32_t i;
        float f;
    } r;
    /* 3 because it's 0011, the first bit is the float's sign.
     * Clearing the second bit eliminates values > 1.0f.
    r.i = (rand () & 0xffff) + ((rand () & 0x3fff) << 16);
    return r.f;

int main ()
    srand (time (NULL));

Android WebView, how to handle redirects in app instead of opening a browser

Create a class that implements webviewclient and add the following code that allows ovveriding the url string as shown below. You can see these [example][1]

public class myWebClient extends WebViewClient {

    public boolean shouldOverrideUrlLoading(WebView view, String url) {
         return true;

On your constructor, create a webview object as shown below.

   web = new WebView(this); web.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); 

Then add the following code to perform loading of urls inside your app

       WebSettings settings=web.getSettings(); 
    web.setWebViewClient(new myWebClient()); 
 web.setWebChromeClient(new WebChromeClient() {

How to create localhost database using mysql?

See here for starting the service and here for how to make it permanent. In short to test it, open a "DOS" terminal with administrator privileges and write:

shell> "C:\Program Files\MySQL\[YOUR MYSQL VERSION PATH]\bin\mysqld"

Maximum number of rows of CSV data in excel sheet

In my memory, excel (versions >= 2007) limits the power 2 of 20: 1.048.576 lines.

Csv is over to this boundary, like ordinary text file. So you will be care of the transfer between two formats.

How to convert DataTable to class Object?

Amit, I have used one way to achieve this with less coding and more efficient way.

but it uses Linq.

I posted it here because maybe the answer helps other SO.

Below DAL code converts datatable object to List of YourViewModel and it's easy to understand.

public static class DAL
        public static string connectionString = ConfigurationManager.ConnectionStrings["YourWebConfigConnection"].ConnectionString;

        // function that creates a list of an object from the given data table
        public static List<T> CreateListFromTable<T>(DataTable tbl) where T : new()
            // define return list
            List<T> lst = new List<T>();

            // go through each row
            foreach (DataRow r in tbl.Rows)
                // add to the list

            // return the list
            return lst;

        // function that creates an object from the given data row
        public static T CreateItemFromRow<T>(DataRow row) where T : new()
            // create a new object
            T item = new T();

            // set the item
            SetItemFromRow(item, row);

            // return 
            return item;

        public static void SetItemFromRow<T>(T item, DataRow row) where T : new()
            // go through each column
            foreach (DataColumn c in row.Table.Columns)
                // find the property for the column
                PropertyInfo p = item.GetType().GetProperty(c.ColumnName);

                // if exists, set the value
                if (p != null && row[c] != DBNull.Value)
                    p.SetValue(item, row[c], null);

        //call stored procedure to get data.
        public static DataSet GetRecordWithExtendedTimeOut(string SPName, params SqlParameter[] SqlPrms)
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand();
            SqlDataAdapter da = new SqlDataAdapter();
            SqlConnection con = new SqlConnection(connectionString);

                cmd = new SqlCommand(SPName, con);
                cmd.CommandTimeout = 240;
                cmd.CommandType = CommandType.StoredProcedure;
                da.SelectCommand = cmd;
            catch (Exception ex)
               return ex;

            return ds;

Now, The way to pass and call method is below.

    DataSet ds = DAL.GetRecordWithExtendedTimeOut("ProcedureName");

    List<YourViewModel> model = new List<YourViewModel>();

    if (ds != null)
        //Pass datatable from dataset to our DAL Method.
        model = DAL.CreateListFromTable<YourViewModel>(ds.Tables[0]);                

Till the date, for many of my applications, I found this as the best structure to get data.

isolating a sub-string in a string before a symbol in SQL Server 2008

DECLARE @test nvarchar(100)

SET @test = 'Foreign Tax Credit - 1997'

SELECT @test, left(@test, charindex('-', @test) - 2) AS LeftString,
    right(@test, len(@test) - charindex('-', @test) - 1)  AS RightString

What is the difference between parseInt(string) and Number(string) in JavaScript?

Addendum to @sjngm's answer:

They both also ignore whitespace:

var foo = " 3 "; console.log(parseInt(foo)); // 3 console.log(Number(foo)); // 3

It is not exactly correct. As sjngm wrote parseInt parses string to first number. It is true. But the problem is when you want to parse number separated with whitespace ie. "12 345". In that case
parseInt("12 345") will return 12 instead of 12345. So to avoid that situation you must trim whitespaces before parsing to number. My solution would be:

     var number=parseInt("12 345".replace(/\s+/g, ''),10);

Notice one extra thing I used in parseInt() function. parseInt("string",10) will set the number to decimal format. If you would parse string like "08" you would get 0 because 8 is not a octal number.Explanation is here

Eclipse CDT: no rule to make target all

You have 2 cases

  • If you create Makefile by yourself, go to
  1. Select Project->Properties from the menu bar.
  2. Click C/C++ Build on the left in the dialog that comes up.
  3. Disable generate makefile automatically -> Under the Builder Settings tab on the right, check and make sure the "Build location" is correct (That location is where your Makefile)
  • If you don't have Makefile -> You need Eclipse DS-5 to help you create Makefile
  1. Select Project->Properties from the menu bar.
  2. Click C/C++ Build on the left in the dialog that comes up.
  3. Enable generate makefile automatically

I advise you create Makefile by your self

RAW POST using cURL in PHP

Implementation with Guzzle library:

use GuzzleHttp\Client;
use GuzzleHttp\RequestOptions;

$httpClient = new Client();

$response = $httpClient->post(
        RequestOptions::BODY => 'POST raw request content',
        RequestOptions::HEADERS => [
            'Content-Type' => 'application/x-www-form-urlencoded',


PHP CURL extension:

$curlHandler = curl_init();

curl_setopt_array($curlHandler, [
    CURLOPT_URL => '',

     * Specify POST method
    CURLOPT_POST => true,

     * Specify request content
    CURLOPT_POSTFIELDS => 'POST raw request content',

$response = curl_exec($curlHandler);



Source code

How can I detect keydown or keypress event in angular.js?

You can checkout Angular UI @ which provide details event handle callback function for detecting keydown,keyup,keypress (also Enter key, backspace key, alter key ,control key)

<textarea ui-keydown="{27:'keydownCallback($event)'}"></textarea>
<textarea ui-keypress="{13:'keypressCallback($event)'}"></textarea>
<textarea ui-keydown="{'enter alt-space':'keypressCallback($event)'}"> </textarea>
<textarea ui-keyup="{'enter':'keypressCallback($event)'}"> </textarea>

Disable all gcc warnings

-w is the GCC-wide option to disable warning messages.

"R cannot be resolved to a variable"?

Nothing mentioned above worked for me. However, I fixed it myself.


If you've any other files except activity_main.xml / main.xml inside app_name/res/layout remove it and try clean and build.


The unwanted files or (rather used later) files inside app_name/res/layout would be *.out.xml. Remove the same.

Given URL is not allowed by the Application configuration Facebook application error

I solved this issue by specifying correct site URL in my App Settings. It works fine now. You have to specify your website Url such as

Current timestamp as filename in Java

Improving the @Derek Springer post with fill length function:

public static String getFileWithDate(String fileName, String fileSaperator, String dateFormat) {
    String FileNamePrefix = fileName.substring(0, fileName.lastIndexOf(fileSaperator));
    String FileNameSuffix = fileName.substring(fileName.lastIndexOf(fileSaperator)+1, fileName.length());
    //System.out.println("File= Prefix~Suffix:"+FileNamePrefix +"~"+FileNameSuffix);
    String newFileName = new SimpleDateFormat("'"+FileNamePrefix+"_'"+dateFormat+"'"+fileSaperator+FileNameSuffix+"'").format(new Date());
    System.out.println("New File:"+newFileName);
    return newFileName;

Using the funciton and its Output:

String fileSaperator = ".", format = "yyyyMMMdd_HHmm";
getFileWithDate("Text1.txt", fileSaperator, format);
getFileWithDate("Text1.doc", fileSaperator, format);
getFileWithDate("Text1.txt.json", fileSaperator, format);


Old File:Text1.txt   New File:Text1_2020Nov11_1807.txt
Old File:Text1.doc   New File:Text1_2020Nov11_1807.doc
Old File:Text1.txt.json  New File:Text1.txt_2020Nov11_1807.json

ActiveRecord OR query

in Rails 3, it should be

Model.where("column = ? or other_column = ?", value, other_value)

This also includes raw sql but I dont think there is a way in ActiveRecord to do OR operation. Your question is not a noob question.

How can I solve the error LNK2019: unresolved external symbol - function?

I just ran into this problem in Visual Studio 2013. Apparently now, having two projects in the same solution and setting the the dependencies is not enough. You need to add a project reference between them. To do that:

  1. Right-click on the project in the solution explore
  2. Click Add => References...
  3. Click the Add New Reference button
  4. Check the boxes for the projects that this project relies on
  5. Click OK

htaccess - How to force the client's browser to clear the cache?

This worked for me.

look for this:

    DirectoryIndex index.php

replace with this:

    DirectoryIndex something.php index.php

Upload and refresh page. You will get a page error.

just change it back to:

    DirectoryIndex index.php

reupload and refresh page again.
I checked this on all of my devices and, it worked.

Is mongodb running?

I know this is for php, but I got here looking for a solution for node. Using mongoskin:

mongodb.admin().ping(function(err) {
    if(err === null)
        // true - you got a conntion, congratulations
    else if(err.message.indexOf('failed to connect') !== -1)
        // false - database isn't around
        // actual error, do something about it

With other drivers, you can attempt to make a connection and if it fails, you know the mongo server's down. Mongoskin needs to actually make some call (like ping) because it connects lazily. For php, you can use the try-to-connect method. Make a script!


$dbIsRunning = true
try {
  $m = new MongoClient('localhost:27017');
} catch($e) {
  $dbIsRunning = false

using wildcards in LDAP search filters/queries

A filter argument with a trailing * can be evaluated almost instantaneously via an index lookup. A leading * implies a sequential search through the index, so it is O(N). It will take ages.

I suggest you reconsider the requirement.

What's the valid way to include an image with no src?

Simply, Like this:

<img id="give_me_src"/>

How to resize an image to a specific size in OpenCV?

The two functions you need are documented here:

  1. imread: read an image from disk.
  2. Image resizing: resize to just any size.

In short:

// Load images in the C++ format
cv::Mat img = cv::imread("something.jpg");
cv::Mat src = cv::imread("src.jpg");

// Resize src so that is has the same size as img
cv::resize(src, src, img.size());

And please, please, stop using the old and completely deprecated IplImage* classes

Count records for every month in a year

select count(*) 
from table_emp 

Login failed for user 'NT AUTHORITY\NETWORK SERVICE'

The Best way is to create a user for your application and assign the permissions that are suitable for that user. Dont use 'NT AUTHORITY\NETWORK SERVICE' as your user it has its own vulnerability and it is a user that has permissions to so many things on the OS level. Stay away from this built in user.

What's the difference between ClusterIP, NodePort and LoadBalancer service types in Kubernetes?

  1. clusterIP : IP accessible inside cluster (across nodes within d cluster).
nodeA : pod1 => clusterIP1, pod2 => clusterIP2
nodeB : pod3 => clusterIP3.

pod3 can talk to pod1 via their clusterIP network.

  1. nodeport : to make pods accessible from outside the cluster via nodeIP:nodeport, it will create/keep clusterIP above as its clusterIP network.
nodeA => nodeIPA : nodeportX
nodeB => nodeIPB : nodeportX

you might access service on pod1 either via nodeIPA:nodeportX OR nodeIPB:nodeportX. Either way will work because kube-proxy (which is installed in each node) will receive your request and distribute it [redirect it(iptables term)] across nodes using clusterIP network.

  1. Load balancer

basically just putting LB in front, so that inbound traffic is distributed to nodeIPA:nodeportX and nodeIPB:nodeportX then continue with the process flow number 2 above.

SQL Server: Best way to concatenate multiple columns?

Through discourse it's clear that the problem lies in using VS2010 to write the query, as it uses the canonical CONCAT() function which is limited to 2 parameters. There's probably a way to change that, but I'm not aware of it.

An alternative:

SELECT '1'+'2'+'3'

This approach requires non-string values to be cast/converted to strings, as well as NULL handling via ISNULL() or COALESCE():

      + COALESCE(CONVERT(VARCHAR(50),Col2),'')

Force Java timezone as GMT/UTC

I would retrieve the time from the DB in a raw form (long timestamp or java's Date), and then use SimpleDateFormat to format it, or Calendar to manipulate it. In both cases you should set the timezone of the objects before using it.

See SimpleDateFormat.setTimeZone(..) and Calendar.setTimeZone(..) for details

what is reverse() in Django

There is a doc for that

it can be used to generate an URL for a given view

main advantage is that you do not hard code routes in your code.

how to use JSON.stringify and json_decode() properly

When you save some data using JSON.stringify() and then need to read that in php. The following code worked for me.

json_decode( html_entity_decode( stripslashes ($jsonString ) ) );

Thanks to @Thisguyhastwothumbs

How do I find the length (or dimensions, size) of a numpy matrix in python?

shape is a property of both numpy ndarray's and matrices.


will return a tuple (m, n), where m is the number of rows, and n is the number of columns.

In fact, the numpy matrix object is built on top of the ndarray object, one of numpy's two fundamental objects (along with a universal function object), so it inherits from ndarray

$.browser is undefined error

The .browser call has been removed in jquery 1.9 have a look at for more details.

How to set a text box for inputing password in winforms?

private void cbShowHide_CheckedChanged(object sender, EventArgs e)
    if (cbShowHide.Checked)
        txtPin.UseSystemPasswordChar = PasswordPropertyTextAttribute.No.Password;
        //Hides Textbox password
        txtPin.UseSystemPasswordChar = PasswordPropertyTextAttribute.Yes.Password;

Copy this code to show and hide your textbox using a checkbox

LogCat message: The Google Play services resources were not found. Check your project configuration to ensure that the resources are included

For IntelliJ IDEA users

After struggling for a couple of days, the only way to make it work in IntelliJ IDEA 13 was to import the library. Here are all the steps:

  1. Update Android SDK so the latest Play Service is installed.
  2. Go to the android-sdk-root/extras/google/google_play_services/libproject directory.
  3. Copy google-play-services_lib and paste it next to your IntelliJ IDEA project (some recommend using this directory directly, but I advise to keep this code clean!).
  4. Open IntelliJ IDEA project properties and add new Module google-play-services_lib.
  5. Check if it's marked as a Library.
  6. Add google-play-services_lib library project as a dependency to the main project.
  7. Add google-play-services library as a dependency library as well.

On the link I provided below, you can see an image of how it looks in my IntelliJ IDEA 13. It would not work without adding only one of these two.

PS. I asked a question, Why does IntelliJ IDEA 13 require both lib project and lib itself (google-play-service) to be added as a dependency?, why is it a must in IntelliJ IDEA 13, and why we cannot import either the library or project only.

CSS media query to target only iOS devices

As mentioned above, the short answer is no. But I'm in need of something similar in the app I'm working on now, yet the areas where the CSS needs to be different are limited to very specific areas of a page.

If you're like me and don't need to serve up an entirely different stylesheet, another option would be to detect a device running iOS in the way described in this question's selected answer: Detect if device is iOS

Once you've detected the iOS device you could add a class to the area you're targeting using Javascript (eg. the document.getElementsByTagName("yourElementHere")[0].setAttribute("class", "iOS-device");, jQuery, PHP or whatever, and style that class accordingly using the pre-existing stylesheet.

.iOS-device {
      style-you-want-to-set: yada;

List all employee's names and their managers by manager name using an inner join

select a.empno,a.ename,a.job,a.mgr,B.empno,B.ename as MGR_name, B.job as MGR_JOB from 
    emp a, emp B where a.mgr=B.empno ;

SQL How to remove duplicates within select query?

here is the solution for your query returning only one row for each date in that table here in the solution 'tony' will occur twice as two different start dates are there for it


Disable output buffering

def disable_stdout_buffering():
    # Appending to gc.garbage is a way to stop an object from being
    # destroyed.  If the old sys.stdout is ever collected, it will
    # close() stdout, which is not good.
    sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0)

# Then this will give output in the correct order:
print "hello"["echo", "bye"])

Without saving the old sys.stdout, disable_stdout_buffering() isn't idempotent, and multiple calls will result in an error like this:

Traceback (most recent call last):
  File "test/", line 17, in <module>
    print "hello"
IOError: [Errno 9] Bad file descriptor
close failed: [Errno 9] Bad file descriptor

Another possibility is:

def disable_stdout_buffering():
    fileno = sys.stdout.fileno()
    temp_fd = os.dup(fileno)
    os.dup2(temp_fd, fileno)
    sys.stdout = os.fdopen(fileno, "w", 0)

(Appending to gc.garbage is not such a good idea because it's where unfreeable cycles get put, and you might want to check for those.)

Moving average or running mean

For a ready-to-use solution, see It provides running average with the flat window type. Note that this is a bit more sophisticated than the simple do-it-yourself convolve-method, since it tries to handle the problems at the beginning and the end of the data by reflecting it (which may or may not work in your case...).

To start with, you could try:

a = np.random.random(100)
b = smooth(a, window='flat')

Code formatting shortcuts in Android Studio for Operation Systems

Just select the code and

  • on Windows do Ctrl + Alt + L

  • on Linux do Ctrl + Super + Alt + L

  • on Mac do CMD + Alt + L

This solution from junaidp

hibernate - get id after save object

or in a better way we can have like this

Let's say your primary key is an Integer and object you save is "ticket", then you can get it like this. When you save the object, id is always returned

//unboxing will occur here so that id here will be value type not the reference type. Now you can check id for 0 in case of save failure. like below:

int id = (Integer); 
   your call was not success. 
else '
   your call to was successful.

Batch script to install MSI

This is how to install a normal MSI file silently:

msiexec.exe /i c:\setup.msi /QN /L*V "C:\Temp\msilog.log"

Quick explanation:

 /L*V "C:\Temp\msilog.log"= verbose logging at indicated path
 /QN = run completely silently
 /i = run install sequence 

The msiexec.exe command line is extensive with support for a variety of options. Here is another overview of the same command line interface. Here is an annotated versions (was broken, resurrected via way back machine).

It is also possible to make a batch file a lot shorter with constructs such as for loops as illustrated here for Windows Updates.

If there are check boxes that must be checked during the setup, you must find the appropriate PUBLIC PROPERTIES attached to the check box and set it at the command line like this:

msiexec.exe /i c:\setup.msi /QN /L*V "C:\Temp\msilog.log" STARTAPP=1 SHOWHELP=Yes

These properties are different in each MSI. You can find them via the verbose log file or by opening the MSI in Orca, or another appropriate tool. You must look either in the dialog control section or in the Property table for what the property name is. Try running the setup and create a verbose log file first and then search the log for messages ala "Setting property..." and then see what the property name is there. Then add this property with the value from the log file to the command line.

Also have a look at how to use transforms to customize the MSI beyond setting command line parameters: How to make better use of MSI files

get all the images from a folder in php

$dir = "mytheme/images/myimages";
$dh  = opendir($dir);
while (false !== ($filename = readdir($dh))) {
    $files[] = $filename;
$images=preg_grep ('/\.jpg$/i', $files);

Very fast because you only scan the needed directory.

Access all Environment properties as a Map or Properties object

For Spring Boot, the accepted answer will overwrite duplicate properties with lower priority ones. This solution will collect the properties into a SortedMap and take only the highest priority duplicate properties.

final SortedMap<String, String> sortedMap = new TreeMap<>();
for (final PropertySource<?> propertySource : env.getPropertySources()) {
    if (!(propertySource instanceof EnumerablePropertySource))
    for (final String name : ((EnumerablePropertySource<?>) propertySource).getPropertyNames())
        sortedMap.computeIfAbsent(name, propertySource::getProperty);

Cannot use string offset as an array in php

The error occurs when:

$a = array(); 
$a['text1'] = array();
$a['text1']['text2'] = 'sometext';


echo $a['text1']['text2'];     //Error!!


$b = $a['text1'];
echo $b['text2'];    // prints: sometext


Explanation of polkitd Unregistered Authentication Agent

I found this problem too. Because centos service depend on for none desktop Cenots 7.2. so I delete from my .service file. It had missed.

Do conditional INSERT with SQL?

You can do that with a single statement and a subquery in nearly all relational databases.

INSERT INTO targetTable(field1) 
SELECT field1
FROM myTable
WHERE NOT(field1 IN (SELECT field1 FROM targetTable))

Certain relational databases have improved syntax for the above, since what you describe is a fairly common task. SQL Server has a MERGE syntax with all kinds of options, and MySQL has optional INSERT OR IGNORE syntax.

Edit: SmallSQL's documentation is fairly sparse as to which parts of the SQL standard it implements. It may not implement subqueries, and as such you may be unable to follow the advice above, or anywhere else, if you need to stick with SmallSQL.

php exec() is not executing the command

You might also try giving the full path to the binary you're trying to run. That solved my problem when trying to use ImageMagick.

Hide axis and gridlines Highcharts

This has always worked well for me:

yAxes: [{
         ticks: {
                 display: false;

Error:java: invalid source release: 8 in Intellij. What does it mean?

As Andreas mentioned all about:

Error:java: invalid source release: 8 in IntelliJ
Error:java: invalid source release: 13 in IntelliJ
Error:java: invalid source release: 14 in IntelliJ...

OR whatever version you are using in Java...

The problem will exist if you do not have it matching inside the below code:


This 1.8 in my case, must be matching on your device through MAVEN project library, settings, preferences, project setting and SDK.

How do you properly return multiple values from a Promise?

You can return an object containing both values — there's nothing wrong with that.

Another strategy is to keep the value, via closures, instead of passing it through:


function afterSomething(amazingData) {
  return processAsync(amazingData).then(function (processedData) {
    // both amazingData and processedData are in scope here

Fully rather than partially inlined form (equivalent, arguably more consistent):

somethingAsync().then(function (amazingData) {
  return processAsync(amazingData).then(function (processedData) {
    // both amazingData and processedData are in scope here

Tests not running in Test Explorer

I use VS2019 with .Net 4.7. I installed NUnit extension v3, and changed the Test settings to use X64. My unit test project is Any CPU (would work if I changed it to x64). Now I can debug through my code.

Change New Google Recaptcha (v2) Width

I have found following best ways to resize google recaptchas

Option 1: You can resize google ReCaptcha by using inline style.

A very first way for resizing google recapture by using inline style. Inline styles are CSS styles that are applied to one element, directly in the page's HTML, using the style attribute. Here is the example that shows you how you to style Google reCAPTCHA by using inline style.

<div class="g-recaptcha" style="transform: scale(0.77); -webkit-transform: scale(0.77); transform-origin: 0 0; -webkit-transform-origin: 0 0;" data-theme="light" data-sitekey="XXXXXXXXXXXXX"></div>

Option 2: By putting the following style in your page (Internal Style Sheet).

Secondly, you can put style for ReCaptcha into the page between and . An internal style sheet is a section on an HTML page that contains style definitions. Internal style sheets are defined by using the tag within the area of the document. Here is the example that shows you how you to style Google reCAPTCHA by using an external style sheet.

<style type="text/css">
transform-origin:0 0;
-webkit-transform-origin:0 0;

Option 3: Resize google ReCaptcha by using an external stylesheet.

Create a separate file and give a name like style.css and add this file link in between your an element in your page. For ex. .

<style type="text/css">
transform-origin:0 0;
-webkit-transform-origin:0 0;

Reference from the blog:

datetime datatype in java

You can use Calendar.

     Calendar rightNow = Calendar.getInstance();


Date4j alternative to Date, Calendar, and related Java classes

MySQL - force not to use cache for testing speed of query

Try using the SQL_NO_CACHE (MySQL 5.7) option in your query. (MySQL 5.6 users click HERE )



This will stop MySQL caching the results, however be aware that other OS and disk caches may also impact performance. These are harder to get around.

Magento Product Attribute Get Value

First we must ensure that the desired attribute is loaded, and then output it. Use this:

$product = Mage::getModel('catalog/product')->load('<product_id>', array('<attribute_code>'));
$attributeValue = $product->getResource()->getAttribute('<attribute_code>')->getFrontend()->getValue($product);

Epoch vs Iteration when training neural networks

Typically, you'll split your test set into small batches for the network to learn from, and make the training go step by step through your number of layers, applying gradient-descent all the way down. All these small steps can be called iterations.

An epoch corresponds to the entire training set going through the entire network once. It can be useful to limit this, e.g. to fight overfitting.

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

I'm hoping you are having the same problem that I had... my issue was simple: Make a fixed textarea with locked percentages inside the container (I'm new to CSS/JS/HTML, so bear with me, if I don't get the lingo correct) so that no matter the device it's displaying on, the box filling the container (the table cell) takes up the correct amount of space. Here's how I solved it:

<table width=100%>
    <tr class="idbbs">
        <textarea id="bsinpt"></textarea>

Then CSS Looks like this...

    color: gainsboro;
    float: none;
    background: black;
    text-align: left;
    font-family: "Helvetica", "Tahoma", "Verdana", "Arial Black", sans-serif;
    font-size: 100%;
  position: absolute;
  min-height: 60%;
  min-width: 88%;
  max-height: 60%;
  max-width: 88%;
  resize: none;
    border-top-color: lightsteelblue;
    border-top-width: 1px;
    border-left-color: lightsteelblue;
    border-left-width: 1px;
    border-right-color: lightsteelblue;
    border-right-width: 1px;
    border-bottom-color: lightsteelblue;
    border-bottom-width: 1px;

Sorry for the sloppy code block here, but I had to show you what's important and I don't know how to insert quoted CSS code on this website. In any case, to ensure you see what I'm talking about, the important CSS is less indented here...

What I then did (as shown here) is very specifically tweak the percentages until I found the ones that worked perfectly to fit display, no matter what device screen is used.

Granted, I think the "resize: none;" is overkill, but better safe than sorry and now the consumers will not have anyway to resize the box, nor will it matter what device they are viewing it from.

It works great.

Android Studio cannot resolve R in imported project?

My problem was that I had file 'default.jpg' in drawable folder and for some reason every resource was not resolved. Fixed after deleting that file!

XPath contains(text(),'some string') doesn't work when used with node with more than one Text subnode

It took me a little while but finally figured out. Custom xpath that contains some text below worked perfectly for me.


Cast a Double Variable to Decimal

Convert.ToDecimal(the double you are trying to convert);

Allowing Untrusted SSL Certificates with HttpClient

If you are using System.Net.Http.HttpClient I believe correct pattern is

var handler = new HttpClientHandler() 
    ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator

var http = new HttpClient(handler);
var res = http.GetAsync(url);

How to store Emoji Character in MySQL Database

My answer only adds to Selvamani P answer.

You might also need to change any SET NAMES utf8 queries with SET NAMES utf8mb4. That did the trick for me.

Also, this is a great article to port your website from utf8 to utf8mb4. In particular the article makes 2 good points on indexes and repairing tables after converting them to utf8mb4:


When converting from utf8 to utf8mb4, the maximum length of a column or index key is unchanged in terms of bytes. Therefore, it is smaller in terms of characters, because the maximum length of a character is now four bytes instead of three. [...] The InnoDB storage engine has a maximum index length of 767 bytes, so for utf8 or utf8mb4 columns, you can index a maximum of 255 or 191 characters, respectively. If you currently have utf8 columns with indexes longer than 191 characters, you will need to index a smaller number of characters when using utf8mb4.


After upgrading the MySQL server and making the necessary changes explained above, make sure to repair and optimize all databases and tables. I didn’t do this right away after upgrading (I didn’t think it was necessary, as everything seemed to work fine at first glance), and ran into some weird bugs where UPDATE statements didn’t have any effect, even though no errors were thrown.

Read more about the queries to repair tables on the article.

Read response body in JAX-RS client from a post request

Acording with the documentation, the method getEntity in Jax rs 2.0 return a InputStream. If you need to convert to InputStream to String with JSON format, you need to cast the two formats. For example in my case, I implemented the next method:

    private String processResponse(Response response) {
    if (response.getEntity() != null) {
        try {
            InputStream salida = (InputStream) response.getEntity();
            StringWriter writer = new StringWriter();
            IOUtils.copy(salida, writer, "UTF-8");
            return writer.toString();
        } catch (IOException ex) {
            LOG.log(Level.SEVERE, null, ex);
    return null;

why I implemented this method. Because a read in differets blogs that many developers they have the same problem whit the version in jaxrs using the next methods

String output = response.readEntity(String.class)


String output = response.getEntity(String.class)

The first works using jersey-client from com.sun.jersey library and the second found using the jersey-client from org.glassfish.jersey.core.

This is the error that was being presented to me: org.glassfish.jersey.client.internal.HttpUrlConnector$2 cannot be cast to java.lang.String

I use the following maven dependency:


What I do not know is why the readEntity method does not work.I hope you can use the solution.

Carlos Cepeda

Loop through properties in JavaScript object with Lodash

For your stated desire to "check if a property exists" you can directly use Lo-Dash's has.

var exists = _.has(myObject, propertyNameToCheck);

Use a URL to link to a Google map with a marker on it


Example for Mount Everest:


Full reference here:

-- EDIT --

Apparently the zoom parameter stopped working, here's the updated format.



How to access the local Django webserver from outside world

install ngrok in terminal

sudo apt-get install -y ngrok-client

after that run:

ngrok http 8000
ngrok http 

Credit card payment gateway in PHP?

The best solution we found was to team up with one of those intermediaries. Otherwise you will have to deal with a bunch of other requirements like PCI compliance. We use Verifone's IPCharge and it works quite well.

Linq filter List<string> where it contains a string value from another List<string>

you can do that

var filteredFileList = fileList.Where(fl => filterList.Contains(fl.ToString()));

How do I pull from a Git repository through an HTTP proxy?

Worth to mention: Most examples on the net show examples like

git config --global http.proxy proxy_user:proxy_passwd@proxy_ip:proxy_port

So it seems, that - if your proxy needs authentication - you must leave your company-password in the git-config. Which isn't really cool.

But, if you just configure the user without password:

git config --global http.proxy proxy_user@proxy_ip:proxy_port

Git seems (at least on my Windows-machine without credentials-helper) to recognize that and prompts for the proxy-password on repo-access.

Distinct pair of values SQL

If you just want a count of the distinct pairs.

The simplest way to do that is as follows SELECT COUNT(DISTINCT a,b) FROM pairs

The previous solutions would list all the pairs and then you'd have to do a second query to count them.

how to kill hadoop jobs

Use of folloing command is depreciated

hadoop job -list
hadoop job -kill $jobId

consider using

mapred job -list
mapred job -kill $jobId

PostgreSQL JOIN data from 3 tables

Maybe the following is what you are looking for:

SELECT name, pathfilename
  FROM table1
  WHERE name = 'John';

Makefile, header dependencies

I prefer this solution, over the accepted answer by Michael Williamson, it catches changes to sources+inline files, then sources+headers, and finally sources only. Advantage here is that the whole library is not recompiled if only a a few changes are made. Not a huge consideration for a project with a couple of files, bur if you have 10 or a 100 sources, you will notice the difference.

COMMAND= gcc -Wall -Iinclude ...

%.o: %.cpp %.inl

%.o: %.cpp %.hpp

%.o: %.cpp

count files in specific folder and display the number into 1 cel

Try below code :

Assign the path of the folder to variable FolderPath before running the below code.

Sub sample()

    Dim FolderPath As String, path As String, count As Integer
    FolderPath = "C:\Documents and Settings\Santosh\Desktop"

    path = FolderPath & "\*.xls"

    Filename = Dir(path)

    Do While Filename <> ""
       count = count + 1
        Filename = Dir()

    Range("Q8").Value = count
    'MsgBox count & " : files found in folder"
End Sub

Calling C/C++ from Python?

There is also pybind11, which is like a lightweight version of Boost.Python and compatible with all modern C++ compilers:

How to override maven property in command line?

See Introduction to the POM

finalName is created as:


One of the solutions is to add own property:


And now try:

mvn -DfinalName=build clean package

How to update data in one table from corresponding data in another table in SQL Server 2005

Try a query like


Fiddler not capturing traffic from browsers

After hours of googling, reading, uninstalling, facepalming! It turned out that a chrome extension for VPN was handling the proxy settings for Chrome!

Betternet to be more specific!

Disabling it, solved my problem.

To make sure it is not the problem, check the proxy settings for Chrome itself. For me it showed me a message, says : Betternet is handling the proxy settings.

How to check list A contains any value from list B?

If you didn't care about performance, you could try:

a.Any(item => b.Contains(item))
// or, as in the column using a method group

But I would try this first:


How to transition to a new view controller with code only using Swift

For anyone doing this on iOS8, this is what I had to do:

I have a swift class file titled SettingsView.swift and a .xib file named SettingsView.xib. I run this in MasterViewController.swift (or any view controller really to open a second view controller)

@IBAction func openSettings(sender: AnyObject) {
        var mySettings: SettingsView = SettingsView(nibName: "SettingsView", bundle: nil) /<--- Notice this "nibName" 
        var modalStyle: UIModalTransitionStyle = UIModalTransitionStyle.CoverVertical
        mySettings.modalTransitionStyle = modalStyle
        self.presentViewController(mySettings, animated: true, completion: nil)


Access Enum value using EL with JSTL

When using a MVC framework I put the following in my controller.


This allows me to use the following in my JSP Page.

<script> var url = '${INBOX_ACTION}=' + someValue;</script>

It can also be used in your comparison

<c:when test="${someModel.action == INBOX_ACTION}">

Which I prefer over putting in a string literal.

Use CSS3 transitions with gradient backgrounds

You can FAKE transitions between gradients, using transitions in the opacity of a few stacked gradients, as described in a few of the answers here:

CSS3 animation with gradients.

You can also transition the position instead, as described here:

CSS3 gradient transition with background-position.

Some more techniques here:

Animating CSS3 Gradients.

Hibernate throws MultipleBagFetchException - cannot simultaneously fetch multiple bags

You could use a new annotation to solve this:

@XXXToXXX(targetEntity = XXXX.class, fetch = FetchType.LAZY)

In fact, fetch's default value is FetchType.LAZY too.

Can I embed a .png image into an html page?

use mod_rewrite to redirect the call to file.html to image.png without the url changing for the user

Have you tried just renaming the image.png file to file.html? I think most browser take mime header over file extension :)

Could not find method android() for arguments

guys. I had the same problem before when I'm trying import a .aar package into my project, and unfortunately before make the .aar package as a module-dependence of my project, I had two modules (one about ROS-ANDROID-CV-BRIDGE, one is OPENCV-FOR-ANDROID) already. So, I got this error as you guys meet:

Error:Could not find method android() for arguments [org.ros.gradle_plugins.RosAndroidPlugin$_apply_closure2_closure4@7e550e0e] on project ‘:xxx’ of type org.gradle.api.Project.

So, it's the painful gradle-structure caused this problem when you have several modules in your project, and worse, they're imported in different way or have different types (.jar/.aar packages or just a project of Java library). And it's really a headache matter to make the configuration like compile-version, library dependencies etc. in each subproject compatible with the main-project.

I solved my problem just follow this steps:

? Copy .aar package in app/libs.

? Add this in app/build.gradle file:

repositories {
    flatDir {
        dirs 'libs' //this way we can find the .aar file in libs folder

? Add this in your add build.gradle file of the module which you want to apply the .aar dependence (in my situation, just add this in my app/build.gradle file):

dependencies {
    compile(name:'package_name', ext:'aar')

So, if it's possible, just try export your module-dependence as a .aar package, and then follow this way import it to your main-project. Anyway, I hope this can be a good suggestion and would solve your problem if you have the same situation with me.

What does mscorlib stand for?

Microsoft Core Library, ie they are at the heart of everything.

There is a more "massaged" explanation you may prefer:

"When Microsoft first started working on the .NET Framework, MSCorLib.dll was an acronym for Microsoft Common Object Runtime Library. Once ECMA started to standardize the CLR and parts of the FCL, MSCorLib.dll officially became the acronym for Multilanguage Standard Common Object Runtime Library."


Around 1999, to my personal memory, .Net was known as "COOL", so I am a little suspicious of this derivation. I never heard it called "COR", which is a silly-sounding name to a native English speaker.

Run .jar from batch-file

cd "Your File Location without inverted commas"

example : cd C:\Users*****\Desktop\directory\target

java -jar myjar.jar

example bat file looks like this:

@echo OFF
cd C:\Users\****\Desktop\directory\target
java -jar myjar.jar

This will work fine.

Vertical divider doesn't work in Bootstrap 3

Here is some LESS for you, in case you customize the navbar:

.navbar .divider-vertical {
    height: floor(@navbar-height - @navbar-margin-bottom);
    margin: floor(@navbar-margin-bottom / 2) 9px;
    border-left: 1px solid #f2f2f2;
    border-right: 1px solid #ffffff;

How do I edit SSIS package files?

You need the Business Intelligence Studio ..I've checked and my version of VS2008 Pro doesn't have them installed.

Have a look at this link:

Is it worth using Python's re.compile?

As an alternative answer, as I see that it hasn't been mentioned before, I'll go ahead and quote the Python 3 docs:

Should you use these module-level functions, or should you get the pattern and call its methods yourself? If you’re accessing a regex within a loop, pre-compiling it will save a few function calls. Outside of loops, there’s not much difference thanks to the internal cache.

python pip - install from local dir

You were looking for help on installations with pip. You can find it with the following command:

pip install --help

Running pip install -e /path/to/package installs the package in a way, that you can edit the package, and when a new import call looks for it, it will import the edited package code. This can be very useful for package development.

ORDER BY using Criteria API

You need to create an alias for the mother.kind. You do this like so.

Criteria c = session.createCriteria(Cat.class);
c.createAlias("mother.kind", "motherKind");
return c.list();

Responsive width Facebook Page Plugin

It seems that Facebook Page Plugin doesn't change at all in past  5-7 years :) It wasn't responsive from the begining and still not now, even new param Adapt to plugin container width doesn't work or I don't understand how it works.

I'm searching for the most posible simple way to do PLUGIN SIZE 100% WIDTH, and it seems it is not posible. Nonsense at it's best. How designers solve this problem?

I found the best decision for this time 2017 Oct:

.fb-page, .fb-page iframe[style], .fb-page span {
    width: 100% !important;
.fb-comments, .fb-comments iframe[style], .fb-comments span {
   width: 100% !important;

This lets do not broke screen size width for responsive screens, but still looks ugly, because cuted in some time and doesn't stretch... Facebook doesn't care about plugins design at all. That's the truth.

"The page you are requesting cannot be served because of the extension configuration." error message

I fixed that on my Windows 10:

  1. Go to Control Panel - Programs and Features - Turn Windows features on or off.

  2. Select .NET Framework 4.6 Advanced Services - WCF Services

  3. Check HTTP Activation.

  4. OK done.

Fully backup a git repo?

The correct answer IMO is git clone --mirror. This will fully backup your repo.

Git clone mirror will clone the entire repository, notes, heads, refs, etc. and is typically used to copy an entire repository to a new git server. This will pull down an all branches and everything, the entire repository.

git clone --mirror [email protected]/your-repo.git
  • Normally cloning a repo does not include all branches, only Master.

  • Copying the repo folder will only "copy" the branches that have been pulled by default that is Master branch only or other branches you have checked-out previously.

  • The Git bundle command is also not what you want: "The bundle command will package up everything that would normally be pushed over the wire with a git push command into a binary file that you can email to someone or put on a flash drive, then unbundle into another repository." (From What's the difference between git clone --mirror and git clone --bare)

Using stored procedure output parameters in C#

In your C# code, you are using transaction for the command. Just commit the transaction and after that access your parameter value, you will get the value. Worked for me. :)

Excel VBA Password via Hex Editor

If you deal with .xlsm file instead of .xls you can use the old method. I was trying to modify vbaProject.bin in .xlsm several times using DBP->DBx method by it didn't work, also changing value of DBP didn't. So I was very suprised that following worked :
1. Save .xlsm as .xls.
2. Use DBP->DBx method on .xls.
3. Unfortunately some erros may occur when using modified .xls file, I had to save .xls as .xlsx and add modules, then save as .xlsm.

Intersection and union of ArrayLists in Java

If the number matches than I am checking it's occur first time or not with help of "indexOf()" if the number matches first time then print and save into in a string so, that when the next time same number matches then it's won't print because due to "indexOf()" condition will be false.

class Intersection
public static void main(String[] args)
  String s="";
    int[] array1 = {1, 2, 5, 5, 8, 9, 7,2,3512451,4,4,5 ,10};
    int[] array2 = {1, 0, 6, 15, 6, 5,4, 1,7, 0,5,4,5,2,3,8,5,3512451};

       for (int i = 0; i < array1.length; i++)
           for (int j = 0; j < array2.length; j++)
               char c=(char)(array1[i]);
               if(array1[i] == (array2[j])&&s.indexOf(c)==-1)
                System.out.println("Common element is : "+(array1[i]));


Tesseract OCR simple example

Ok. I found the solution here tessnet2 fails to load the Ans given by Adam

Apparently i was using wrong version of tessdata. I was following the the source page instruction intuitively and that caused the problem.

it says

Quick Tessnet2 usage

  1. Download binary here, add a reference of the assembly Tessnet2.dll to your .NET project.

  2. Download language data definition file here and put it in tessdata directory. Tessdata directory and your exe must be in the same directory.

After you download the binary, when you follow the link to download the language file, there are many language files. but none of them are right version. you need to select all version and go to next page for correct version (tesseract-2.00.eng)! They should either update download binary link to version 3 or put the the version 2 language file on the first page. Or at least bold mention the fact that this version issue is a big deal!

Anyway I found it. Thanks everyone.

Click button copy to clipboard using jQuery

The text to copy is in text input,like: <input type="text" id="copyText" name="copyText"> and, on button click above text should get copied to clipboard,so button is like:<button type="submit" id="copy_button" data-clipboard-target='copyText'>Copy</button> Your script should be like:

<script language="JavaScript">
$(document).ready(function() {
var clip = new ZeroClipboard($("#copy_button"), {
  moviePath: "ZeroClipboard.swf"


For CDN files

note: ZeroClipboard.swf and ZeroClipboard.js" file should be in the same folder as your file using this functionality is, OR you have to include like we include <script src=""></script> on our pages.

splitting a string based on tab in the file

You can use regex here:

>>> import re
>>> strs = "foo\tbar\t\tspam"
>>> re.split(r'\t+', strs)
['foo', 'bar', 'spam']


You can use str.rstrip to get rid of trailing '\t' and then apply regex.

>>> yas = "yas\t\tbs\tcda\t\t"
>>> re.split(r'\t+', yas.rstrip('\t'))
['yas', 'bs', 'cda']

Prevent RequireJS from Caching Required Scripts

Do not use urlArgs for this!

Require script loads respect http caching headers. (Scripts are loaded with a dynamically inserted <script>, which means the request looks just like any old asset getting loaded.)

Serve your javascript assets with the proper HTTP headers to disable caching during development.

Using require's urlArgs means any breakpoints you set will not be preserved across refreshes; you end up needing to put debugger statements everywhere in your code. Bad. I use urlArgs for cache-busting assets during production upgrades with the git sha; then I can set my assets to be cached forever and be guaranteed to never have stale assets.

In development, I mock all ajax requests with a complex mockjax configuration, then I can serve my app in javascript-only mode with a 10 line python http server with all caching turned off. This has scaled up for me to a quite large "enterprisey" application with hundreds of restful webservice endpoints. We even have a contracted designer who can work with our real production codebase without giving him access to our backend code.

Scale Image to fill ImageView width and keep aspect ratio

use android:ScaleType="fitXY" im ImageView xml

Is it safe to delete a NULL pointer?

delete performs the check anyway, so checking it on your side adds overhead and looks uglier. A very good practice is setting the pointer to NULL after delete (helps avoiding double deletion and other similar memory corruption problems).

I'd also love if delete by default was setting the parameter to NULL like in

#define my_delete(x) {delete x; x = NULL;}

(I know about R and L values, but wouldn't it be nice?)

How come I can't remove the blue textarea border in Twitter Bootstrap?

This works 100%.

textarea:focus, input[type="text"]:focus,textarea[type="text"]:focus,   input[type="password"]:focus, input[type="datetime"]:focus, input[type="datetime-local"]:focus, input[type="date"]:focus, input[type="month"]:focus, input[type="time"]:focus, input[type="week"]:focus, input[type="number"]:focus, input[type="email"]:focus, input[type="url"]:focus, input[type="search"]:focus, input[type="tel"]:focus,  input[type="color"]:focus, .uneditable-input:focus, .form-control:focus {  
border-color: (your color) or none;
box-shadow:(your color) or none;
outline: (your color) or none;}

How to auto-format code in Eclipse?

You can do with some step bellow

Step 1: press Ctr + A(windows) or cmd + A (Mac os)

Step 2: Ctr + I in windows or cmd + I in Mac os

It will auto format for you


How can I use Oracle SQL developer to run stored procedures?

I am not sure how to see the actual rows/records that come back.

Stored procedures do not return records. They may have a cursor as an output parameter, which is a pointer to a select statement. But it requires additional action to actually bring back rows from that cursor.

In SQL Developer, you can execute a procedure that returns a ref cursor as follows

var rc refcursor
exec proc_name(:rc)

After that, if you execute the following, it will show the results from the cursor:

print rc

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

Just add a custom property to the page which will return the variable of your choice. You can then use the built-in "control" parameter type.

In the code behind, add:

Dim MyVariable as Long

ReadOnly Property MyCustomProperty As Long
        Return MyVariable
    End Get
End Property

In the select parameters section add:

<asp:ControlParameter ControlID="__Page" Name="MyParameter" 
PropertyName="MyCustomProperty" Type="Int32" />

Platform.runLater and Task in JavaFX

Use Platform.runLater(...) for quick and simple operations and Task for complex and big operations .

Example: Why Can't we use Platform.runLater(...) for long calculations (Taken from below reference).

Problem: Background thread which just counts from 0 to 1 million and update progress bar in UI.

Code using Platform.runLater(...):

final ProgressBar bar = new ProgressBar();
new Thread(new Runnable() {
    @Override public void run() {
    for (int i = 1; i <= 1000000; i++) {
        final int counter = i;
        Platform.runLater(new Runnable() {
            @Override public void run() {
                bar.setProgress(counter / 1000000.0);

This is a hideous hunk of code, a crime against nature (and programming in general). First, you’ll lose brain cells just looking at this double nesting of Runnables. Second, it is going to swamp the event queue with little Runnables — a million of them in fact. Clearly, we needed some API to make it easier to write background workers which then communicate back with the UI.

Code using Task :

Task task = new Task<Void>() {
    @Override public Void call() {
        static final int max = 1000000;
        for (int i = 1; i <= max; i++) {
            updateProgress(i, max);
        return null;

ProgressBar bar = new ProgressBar();
new Thread(task).start();

it suffers from none of the flaws exhibited in the previous code

Reference : Worker Threading in JavaFX 2.0

How to check if a symlink exists

Is the file really a symbolic link? If not, the usual test for existence is -r or -e.

See man test.

jquery validate check at least one checkbox

    rules: {            
        'roles': {
            required: true,
    messages: {            
        'roles': {
            required: "One Option please",

JList add/remove Item

The best and easiest way to clear a JLIST is:

myJlist.setListData(new String[0]);

Pandas read_csv low_memory and dtype options

Sometimes, when all else fails, you just want to tell pandas to shut up about it:

# Ignore DtypeWarnings from pandas' read_csv                                                                                                                                                                                            
warnings.filterwarnings('ignore', message="^Columns.*")

gradlew command not found?

You must have the Gradle wrapper available locally before using gradlew. To construct that

gradle wrapper # --gradle-version v.xy

Optionally, pass the gradle version explicitly. This step produces the gradlew binary.And then you should be able to

./gradlew build

invalid types 'int[int]' for array subscript

What to change? Aside from the 3 or 4 dimensional array problem, you should get rid of the magic numbers (10 and 9).

const int DIM_SIZE = 10;

for (int i = 0; i < DIM_SIZE; ++i){
    for (int t = 0; t < DIM_SIZE; ++t){            
        for (int x = 0; x < DIM_SIZE; ++x){

Regex pattern inside SQL Replace function?

In a general sense, SQL Server does not support regular expressions and you cannot use them in the native T-SQL code.

You could write a CLR function to do that. See here, for example.

How to disable logging on the standard error stream in Python?

Found an elegant solution using decorators, which addresses the following problem: what if you are writing a module with several functions, each of them with several debugging messages, and you want to disable logging in all functions but the one you are currently focusing on?

You can do it using decorators:

import logging, sys
logger = logging.getLogger()
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)

def disable_debug_messages(func):
    def wrapper(*args, **kwargs):
        prev_state = logger.disabled
        logger.disabled = True
        result = func(*args, **kwargs)
        logger.disabled = prev_state
        return result
    return wrapper

Then, you can do:

def function_already_debugged():
    logger.debug("This message won't be showed because of the decorator")

def function_being_focused():
    logger.debug("This message will be showed")

Even if you call function_already_debugged from within function_being_focused, debug messages from function_already_debugged won't be showed. This ensures you will see only the debug messages from the function you are focusing on.

Hope it helps!

Return value from a VBScript function

To return a value from a VBScript function, assign the value to the name of the function, like this:

Function getNumber
    getNumber = "423"
End Function

How to create a TextArea in Android

Use TextView inside a ScrollView to display messages with any no.of lines. User can't edit the text in this view as in EditText.

I think this is good for your requirement. Try it once.

You can change the default color and text size in XML file only if you want to fix them as below:


or if you want to change dynamically whenever you want use as below:

TextView textarea = (TextView)findViewById(;  // tv is id in XML file for TextView
textarea.setTextColor(Color.rgb(0xff, 0, 0));
textarea.setTypeface(Typeface.SERIF, Typeface.ITALIC);

Determine if map contains a value for a key?

If you want to determine whether a key is there in map or not, you can use the find() or count() member function of map. The find function which is used here in example returns the iterator to element or map::end otherwise. In case of count the count returns 1 if found, else it returns zero(or otherwise).

{ //key found
{//key not found

for(int i=0;i<v.size();i++){
    phoneMap::iterator itr=phone.find(v[i]);//I have used a vector in this example to check through map you cal receive a value using at() e.g:;
        cout<<"Not found"<<endl;

Encrypt and Decrypt in Java

Symmetric Key Cryptography : Symmetric key uses the same key for encryption and decryption. The main challenge with this type of cryptography is the exchange of the secret key between the two parties sender and receiver.

Example : The following example uses symmetric key for encryption and decryption algorithm available as part of the Sun's JCE(Java Cryptography Extension). Sun JCE is has two layers, the crypto API layer and the provider layer.

DES (Data Encryption Standard) was a popular symmetric key algorithm. Presently DES is outdated and considered insecure. Triple DES and a stronger variant of DES. It is a symmetric-key block cipher. There are other algorithms like Blowfish, Twofish and AES(Advanced Encryption Standard). AES is the latest encryption standard over the DES.

Steps :

  1. Add the Security Provider : We are using the SunJCE Provider that is available with the JDK.
  2. Generate Secret Key : Use KeyGenerator and an algorithm to generate a secret key. We are using DESede.
  3. Encode Text : For consistency across platform encode the plain text as byte using UTF-8 encoding.
  4. Encrypt Text : Instantiate Cipher with ENCRYPT_MODE, use the secret key and encrypt the bytes.
  5. Decrypt Text : Instantiate Cipher with DECRYPT_MODE, use the same secret key and decrypt the bytes.

All the above given steps and concept are same, we just replace algorithms.

import java.util.Base64;    
import javax.crypto.Cipher;  
import javax.crypto.KeyGenerator;   
import javax.crypto.SecretKey;  
public class EncryptionDecryptionAES {  
    static Cipher cipher;  

    public static void main(String[] args) throws Exception {
         create key 
         If we need to generate a new key use a KeyGenerator
         If we have existing plaintext key use a SecretKeyFactory
        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        keyGenerator.init(128); // block size is 128bits
        SecretKey secretKey = keyGenerator.generateKey();

          Cipher Info
          Algorithm : for the encryption of electronic data
          mode of operation : to avoid repeated blocks encrypt to the same values.
          padding: ensuring messages are the proper length necessary for certain ciphers 
          mode/padding are not used with stream cyphers.  
        cipher = Cipher.getInstance("AES"); //SunJCE provider AES algorithm, mode(optional) and padding schema(optional)  

        String plainText = "AES Symmetric Encryption Decryption";
        System.out.println("Plain Text Before Encryption: " + plainText);

        String encryptedText = encrypt(plainText, secretKey);
        System.out.println("Encrypted Text After Encryption: " + encryptedText);

        String decryptedText = decrypt(encryptedText, secretKey);
        System.out.println("Decrypted Text After Decryption: " + decryptedText);

    public static String encrypt(String plainText, SecretKey secretKey)
            throws Exception {
        byte[] plainTextByte = plainText.getBytes();
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedByte = cipher.doFinal(plainTextByte);
        Base64.Encoder encoder = Base64.getEncoder();
        String encryptedText = encoder.encodeToString(encryptedByte);
        return encryptedText;

    public static String decrypt(String encryptedText, SecretKey secretKey)
            throws Exception {
        Base64.Decoder decoder = Base64.getDecoder();
        byte[] encryptedTextByte = decoder.decode(encryptedText);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedByte = cipher.doFinal(encryptedTextByte);
        String decryptedText = new String(decryptedByte);
        return decryptedText;


Plain Text Before Encryption: AES Symmetric Encryption Decryption
Encrypted Text After Encryption: sY6vkQrWRg0fvRzbqSAYxepeBIXg4AySj7Xh3x4vDv8TBTkNiTfca7wW/dxiMMJl
Decrypted Text After Decryption: AES Symmetric Encryption Decryption


Example: Cipher with two modes, they are encrypt and decrypt. we have to start every time after setting mode to encrypt or decrypt a text. enter image description here

how to generate a unique token which expires after 24 hours?

There are two possible approaches; either you create a unique value and store somewhere along with the creation time, for example in a database, or you put the creation time inside the token so that you can decode it later and see when it was created.

To create a unique token:

string token = Convert.ToBase64String(Guid.NewGuid().ToByteArray());

Basic example of creating a unique token containing a time stamp:

byte[] time = BitConverter.GetBytes(DateTime.UtcNow.ToBinary());
byte[] key = Guid.NewGuid().ToByteArray();
string token = Convert.ToBase64String(time.Concat(key).ToArray());

To decode the token to get the creation time:

byte[] data = Convert.FromBase64String(token);
DateTime when = DateTime.FromBinary(BitConverter.ToInt64(data, 0));
if (when < DateTime.UtcNow.AddHours(-24)) {
  // too old

Note: If you need the token with the time stamp to be secure, you need to encrypt it. Otherwise a user could figure out what it contains and create a false token.

.NET obfuscation tools/strategy

Here's a document from Microsoft themselves. Hope that helps..., it's from 2003, but it might still be relevant.

How to remove selected commit log entries from a Git repository while keeping their changes?

git-rebase(1) does exactly that.

$ git rebase -i HEAD~5

git awsome-ness [git rebase --interactive] contains an example.

  1. Don't use git-rebase on public (remote) commits.
  2. Make sure your working directory is clean (commit or stash your current changes).
  3. Run the above command. It launches your $EDITOR.
  4. Replace pick before C and D by squash. It will meld C and D into B. If you want to delete a commit then just delete its line.

If you are lost, type:

$ git rebase --abort  

Switching users inside Docker image to a non-root user

As a different approach to the other answer, instead of indicating the user upon image creation on the Dockerfile, you can do so via command-line on a particular container as a per-command basis.

With docker exec, use --user to specify which user account the interactive terminal will use (the container should be running and the user has to exist in the containerized system):

docker exec -it --user [username] [container] bash


How to run multiple DOS commands in parallel?

I suggest you to see "How do I run a bat file in the background from another bat file?"

Also, good answer (of using start command) was given in "Parallel execution of shell processes" question page here;

But my recommendation is to use PowerShell. I believe it will perfectly suit your needs.

Gmail Error :The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required

Hi I had the same issue,

what I've done to solve it. is to turn on the less secure app. after connecting to my gmail account. I entered this link:

Then I turn on the secure app and, and the it worked. it has been said also above

CSS rule to apply only if element has BOTH classes {
    /* rules go here */

... or simply: {
    /* rules go here */

Knockout validation

If you don't want to use the KnockoutValidation library you can write your own. Here's an example for a Mandatory field.

Add a javascript class with all you KO extensions or extenders, and add the following:

ko.extenders.required = function (target, overrideMessage) {
    //add some sub-observables to our observable
    target.hasError = ko.observable();
    target.validationMessage = ko.observable();

    //define a function to do validation
    function validate(newValue) {
    target.hasError(newValue ? false : true);
    target.validationMessage(newValue ? "" : overrideMessage || "This field is required");

    //initial validation

    //validate whenever the value changes

    //return the original observable
    return target;

Then in your viewModel extend you observable by:

self.dateOfPayment: ko.observable().extend({ required: "" }),

There are a number of examples online for this style of validation.

How to play CSS3 transitions in a loop?

If you want to take advantage of the 60FPS smoothness that the "transform" property offers, you can combine the two:

@keyframes changewidth {
  from {
    transform: scaleX(1);

  to {
    transform: scaleX(2);

div {
  animation-duration: 0.1s;
  animation-name: changewidth;
  animation-iteration-count: infinite;
  animation-direction: alternate;

More explanation on why transform offers smoother transitions here:

How can a Jenkins user authentication details be "passed" to a script which uses Jenkins API to create jobs?

  • With Jenkins CLI you do not have to reload everything - you just can load the job (update-job command). You can't use tokens with CLI, AFAIK - you have to use password or password file.

  • Token name for user can be obtained via http://<jenkins-server>/user/<username>/configure - push on 'Show API token' button.

  • Here's a link on how to use API tokens (it uses wget, but curl is very similar).

Vuex - Computed property "name" was assigned to but it has no setter

For me it was changing. =;

To what computed returns so;

this.$ =;

Adding CSRFToken to Ajax request

I had this problem in a list of post in a blog, the post are in a view inside a foreach, then is difficult select it in javascript, and the problem of post method and token also exists.

This the code for javascript at the end of the view, I generate the token in javascript functión inside the view and not in a external js file, then is easy use php lavarel to generate it with csrf_token() function, and send the "delete" method directly in params. You can see that I don´t use in var route: {{ route('post.destroy', $post->id}} because I don´t know the id I want delete until someone click in destroy button, if you don´t have this problem you can use {{ route('post.destroy', $post->id}} or other like this.

    $(".destroy").on("click", function(){
         var vid = $(this).attr("id");
         var v_token = "{{csrf_token()}}";
         var params = {_method: 'DELETE', _token: v_token};
         var route = "" + vid + "";
         type: "POST",
         url: route,
         data: params

and this the code of content in view (inside foreach there are more forms and the data of each post but is not inportant by this example), you can see I add a class "delete" to button and I call class in javascript.

      @foreach($posts as $post)
          <form method="POST">
            <button id="{{$post->id}}" class="btn btn-danger btn-sm pull-right destroy" type="button" >eliminar</button>

ERROR: object LD_PRELOAD cannot be preloaded: ignored

The linker takes some environment variables into account. one is LD_PRELOAD

from man 8 ld-linux:

          A whitespace-separated list of additional,  user-specified,  ELF
          shared  libraries  to  be loaded before all others.  This can be
          used  to  selectively  override  functions   in   other   shared
          libraries.   For  setuid/setgid  ELF binaries, only libraries in
          the standard search directories that are  also  setgid  will  be

Therefore the linker will try to load libraries listed in the LD_PRELOAD variable before others are loaded.

What could be the case that inside the variable is listed a library that can't be pre-loaded. look inside your .bashrc or .bash_profile environment where the LD_PRELOAD is set and remove that library from the variable.

Enum to String C++

Kind of an anonymous lookup table rather than a long switch statement:

return (const char *[]) {
    "bananas & monkeys",
    "Round and orange", 

Angular 2 select option (dropdown) - how to get the value on change so it can be used in a function?

values_of_objArray = [
  { id: 3432, name: "Recent" },
  { id: 3442, name: "Most Popular" },
  { id: 3352, name: "Rating" }

private ValueId : number = 0 // this will be used for multi access like 
                             // update, deleting the obj with id.
private selectedObj : any;

private selectedValueObj(id: any) {
  this.ValueId = (id.srcElement ||;
  for (let i = 0; i < this.values_of_objArray.length; i++) {
    if (this.values_of_objArray[i].id == this.ValueId) {
      this.selectedObj = this.values_of_objArray[i];

Now play with this.selectedObj which has the selected obj from the view.


<select name="values_of_obj" class="form-control" [(ngModel)]="ValueId"  
        (change)="selectedValueObj($event)" required>

  <option *ngFor="let Value of values_of_objArray"

converting date time to 24 hour format

just a tip,

try to use JodaTime instead of java,util.Date it is much more powerfull and it has a method toString("") that you can pass the format you want like toString("yyy-MM-dd HH:mm:ss");

How to create a responsive image that also scales up in Bootstrap 3

If setting a fixed width on the image is not an option, here's an alternative solution.

Having a parent div with display: table & table-layout: fixed. Then setting the image to display: table-cell and max-width to 100%. That way the image will fit to the width of its parent.


    .wrapper { float: left; clear: left; display: table; table-layout: fixed; }
    img.img-responsive { display: table-cell; max-width: 100%; }
<div class="wrapper col-md-3">
    <img class="img-responsive" src=""/>


Can I install the "app store" in an IOS simulator?

This is NOT possible

The Simulator does not run ARM code, ONLY x86 code. Unless you have the raw source code from Apple, you won't see the App Store on the Simulator.

The app you write you will be able to test in the Simulator by running it directly from Xcode even if you don't have a developer account. To test your app on an actual device, you will need to be apart of the Apple Developer program.

Check Postgres access for a user

For all users on a specific database, do the following:

# psql
\c your_database
select grantee, table_catalog, privilege_type, table_schema, table_name from information_schema.table_privileges order by grantee, table_schema, table_name;

How can I view a git log of just one user's commits?

If using GitHub:

  • go to branch
  • click on commits

it will show list in below format

branch_x: < comment> 
author_name committed 2 days ago
  • to see individual author's commit ; click on author_name and there you can see all the commit's of that author on that branch

Monitor the Graphics card usage

If you develop in Visual Studio 2013 and 2015 versions, you can use their GPU Usage tool:

Screenshot from MSDN: enter image description here

Moreover, it seems you can diagnose any application with it, not only Visual Studio Projects:

In addition to Visual Studio projects you can also collect GPU usage data on any loose .exe applications that you have sitting around. Just open the executable as a solution in Visual Studio and then start up a diagnostics session and you can target it with GPU usage. This way if you are using some type of engine or alternative development environment you can still collect data on it as long as you end up with an executable.


setBackground vs setBackgroundDrawable (Android)

Use setBackgroundResource(R.drawable.xml/png)

select rows in sql with latest date for each ID repeated multiple times

You can do this with a Correlated Subquery (That is a subquery wherein you reference a field in the main query). In this case:

FROM yourtable t1
WHERE date = (SELECT max(date) from yourtable WHERE id =

Here we give the yourtable table an alias of t1 and then use that alias in the subquery grabbing the max(date) from the same table yourtable for that id.

Generating (pseudo)random alpha-numeric strings

Simple guys .... but remember each byte is random between 0 and 255 which for a random string will be fine. Also remember you'll have two characters to represent each byte.

$str = bin2hex(random_bytes(32));  // 64 character string returned

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

for line in f

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

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

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

        if not line:

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

How to set width and height dynamically using jQuery

or use this syntax:

$("#mainTable").css("width", "100px");
$("#mainTable").css("height", "200px");

Mockito test a void method throws an exception

The parentheses are poorly placed.

You need to use:

doThrow(new Exception()).when(mockedObject).methodReturningVoid(...);

and NOT use:

doThrow(new Exception()).when(mockedObject.methodReturningVoid(...));

This is explained in the documentation

Sending an Intent to browser to open specific URL

From XML

In case if you have the web-address/URL displayed on your view and you want it to make it clikable and direct user to particular website You can use:


In same way you can use different attributes of autoLink(email, phone, map, all) to accomplish your task...

Sql script to find invalid email addresses


create proc GetEmail

@name varchar(22),
@gmail varchar(22)



declare @a varchar(22)

set select @a=substring(@gmail,charindex('@',@gmail),len(@gmail)-charindex('@',@gmail)+1)

if (@a = '

insert into table_name values(@name,@gmail)


print 'please enter valid email address'


Transparent image - background color

If I understand you right, you can do this:

<img src="image.png" style="background-color:red;" />

In fact, you can even apply a whole background-image to the image, resulting in two "layers" without the need for multi-background support in the browser ;)

remove kernel on jupyter notebook

In jupyter notebook run:

!echo y | jupyter kernelspec uninstall unwanted-kernel 

In anaconda prompt run:

jupyter kernelspec uninstall unwanted-kernel

Use of document.getElementById in JavaScript

It is just a selector that helps you select specific tag <p id = 'demo'></p> elements which help you change the behavior, in any event (either mouse or keyboard).

DataTable: How to get item value with row name and column name? (VB)



(This is C# code. Change this to VB equivalent)

How to automatically generate a stacktrace when my program crashes

Even though a correct answer has been provided that describes how to use the GNU libc backtrace() function1 and I provided my own answer that describes how to ensure a backtrace from a signal handler points to the actual location of the fault2, I don't see any mention of demangling C++ symbols output from the backtrace.

When obtaining backtraces from a C++ program, the output can be run through c++filt1 to demangle the symbols or by using abi::__cxa_demangle1 directly.

  • 1 Linux & OS X Note that c++filt and __cxa_demangle are GCC specific
  • 2 Linux

The following C++ Linux example uses the same signal handler as my other answer and demonstrates how c++filt can be used to demangle the symbols.


class foo
    foo() { foo1(); }

    void foo1() { foo2(); }
    void foo2() { foo3(); }
    void foo3() { foo4(); }
    void foo4() { crash(); }
    void crash() { char * p = NULL; *p = 0; }

int main(int argc, char ** argv)
    // Setup signal handler for SIGSEGV

    foo * f = new foo();
    return 0;

Output (./test):

signal 11 (Segmentation fault), address is (nil) from 0x8048e07
[bt]: (1) ./test(crash__3foo+0x13) [0x8048e07]
[bt]: (2) ./test(foo4__3foo+0x12) [0x8048dee]
[bt]: (3) ./test(foo3__3foo+0x12) [0x8048dd6]
[bt]: (4) ./test(foo2__3foo+0x12) [0x8048dbe]
[bt]: (5) ./test(foo1__3foo+0x12) [0x8048da6]
[bt]: (6) ./test(__3foo+0x12) [0x8048d8e]
[bt]: (7) ./test(main+0xe0) [0x8048d18]
[bt]: (8) ./test(__libc_start_main+0x95) [0x42017589]
[bt]: (9) ./test(__register_frame_info+0x3d) [0x8048981]

Demangled Output (./test 2>&1 | c++filt):

signal 11 (Segmentation fault), address is (nil) from 0x8048e07
[bt]: (1) ./test(foo::crash(void)+0x13) [0x8048e07]
[bt]: (2) ./test(foo::foo4(void)+0x12) [0x8048dee]
[bt]: (3) ./test(foo::foo3(void)+0x12) [0x8048dd6]
[bt]: (4) ./test(foo::foo2(void)+0x12) [0x8048dbe]
[bt]: (5) ./test(foo::foo1(void)+0x12) [0x8048da6]
[bt]: (6) ./test(foo::foo(void)+0x12) [0x8048d8e]
[bt]: (7) ./test(main+0xe0) [0x8048d18]
[bt]: (8) ./test(__libc_start_main+0x95) [0x42017589]
[bt]: (9) ./test(__register_frame_info+0x3d) [0x8048981]

The following builds on the signal handler from my original answer and can replace the signal handler in the above example to demonstrate how abi::__cxa_demangle can be used to demangle the symbols. This signal handler produces the same demangled output as the above example.


void crit_err_hdlr(int sig_num, siginfo_t * info, void * ucontext)
    sig_ucontext_t * uc = (sig_ucontext_t *)ucontext;

    void * caller_address = (void *) uc->uc_mcontext.eip; // x86 specific

    std::cerr << "signal " << sig_num 
              << " (" << strsignal(sig_num) << "), address is " 
              << info->si_addr << " from " << caller_address 
              << std::endl << std::endl;

    void * array[50];
    int size = backtrace(array, 50);

    array[1] = caller_address;

    char ** messages = backtrace_symbols(array, size);    

    // skip first stack frame (points here)
    for (int i = 1; i < size && messages != NULL; ++i)
        char *mangled_name = 0, *offset_begin = 0, *offset_end = 0;

        // find parantheses and +address offset surrounding mangled name
        for (char *p = messages[i]; *p; ++p)
            if (*p == '(') 
                mangled_name = p; 
            else if (*p == '+') 
                offset_begin = p;
            else if (*p == ')')
                offset_end = p;

        // if the line could be processed, attempt to demangle the symbol
        if (mangled_name && offset_begin && offset_end && 
            mangled_name < offset_begin)
            *mangled_name++ = '\0';
            *offset_begin++ = '\0';
            *offset_end++ = '\0';

            int status;
            char * real_name = abi::__cxa_demangle(mangled_name, 0, 0, &status);

            // if demangling is successful, output the demangled function name
            if (status == 0)
                std::cerr << "[bt]: (" << i << ") " << messages[i] << " : " 
                          << real_name << "+" << offset_begin << offset_end 
                          << std::endl;

            // otherwise, output the mangled function name
                std::cerr << "[bt]: (" << i << ") " << messages[i] << " : " 
                          << mangled_name << "+" << offset_begin << offset_end 
                          << std::endl;
        // otherwise, print the whole line
            std::cerr << "[bt]: (" << i << ") " << messages[i] << std::endl;
    std::cerr << std::endl;



Resize svg when window is resized in d3.js

Use window.onresize:

function updateWindow(){
    x = w.innerWidth || e.clientWidth || g.clientWidth;
    y = w.innerHeight|| e.clientHeight|| g.clientHeight;

    svg.attr("width", x).attr("height", y);
}'resize.updatesvg', updateWindow);

Warning: mysqli_error() expects exactly 1 parameter, 0 given error

At first, the problem is because you did't put any parameter for mysqli_error. I can see that it has been solved based on the post here. Most probably, the next problem is cause by wrong file path for the included file.. .

Are you sure this code

$myConnection = mysqli_connect("$db_host","$db_username","$db_pass","$db_name") or die ("could not connect to mysql");

is in the 'scripts' folder and your main code file is on the same level as the script folder?

Writing BMP image in pure c/c++ without other libraries

Note that the lines are saved from down to up and not the other way around.

Additionally, the scanlines must have a byte-length of multiples of four, you should insert fill bytes at the end of the lines to ensure this.

How do I check if a string contains a specific word?

Here is a little utility function that is useful in situations like this

// returns true if $needle is a substring of $haystack
function contains($needle, $haystack)
    return strpos($haystack, $needle) !== false;

CSS3 Fade Effect

You can't transition between two background images, as there's no way for the browser to know what you want to interpolate. As you've discovered, you can transition the background position. If you want the image to fade in on mouse over, I think the best way to do it with CSS transitions is to put the image on a containing element and then animate the background colour to transparent on the link itself:

span {
    background: url(button.png) no-repeat 0 0;
a {
    width: 32px;
    height: 32px;
    text-align: left;
    background: rgb(255,255,255);

    -webkit-transition: background 300ms ease-in 200ms; /* property duration timing-function delay */
    -moz-transition: background 300ms ease-in 200ms;
    -o-transition: background 300ms ease-in 200ms;
    transition: background 300ms ease-in 200ms;
a:hover {
    background: rgba(255,255,255,0);

How to Fill an array from user input C#?

I've done it finaly check it and if there is a better way tell me guys

    static void Main()
        double[] array = new double[6];
        Console.WriteLine("Please Sir Enter 6 Floating numbers");
        for (int i = 0; i < 6; i++)
            array[i] = Convert.ToDouble(Console.ReadLine());

        double sum = 0;

        foreach (double d in array)
            sum += d;
        double average = sum / 6;
        Console.WriteLine("The Values you've entered are");
        Console.WriteLine("{0}{1,8}", "index", "value");
        for (int counter = 0; counter < 6; counter++)
            Console.WriteLine("{0,5}{1,8}", counter, array[counter]);
        Console.WriteLine("The average is ;");
        Console.WriteLine("would you like to search for a certain elemnt ? (enter yes or no)");
        string answer = Console.ReadLine();
        switch (answer)
            case "yes":
                Console.WriteLine("please enter the array index you wish to get the value of it");
                int index = Convert.ToInt32(Console.ReadLine());
                Console.WriteLine("The Value of the selected index is:");

            case "no":
                Console.WriteLine("HAVE A NICE DAY SIR");

Custom Input[type="submit"] style not working with jquerymobile button

I'm assume you cannot get css working for your button using anchor tag. So you need to override the css styles which are being overwritten by other elements using !important property.


<a href="#" class="selected_btn" data-role="button">Button name</a>


    border:1px solid red;
    color:red !important;            
    background:url('') repeat-x;

Here is the demo

How to set radio button selected value using jquery

for multiple dropdowns

$('[id^=RBLExperienceApplicable][value='+ SelectedVAlue +']').attr("checked","checked");

here RBLExperienceApplicable is the matching part of the radio button groups input tag ids. and [id^=RBLExperienceApplicable] matches all the radio button whose id start with RBLExperienceApplicable

How to check if a file exists in a shell script

The backdrop to my solution recommendation is the story of a friend who, well into the second week of his first job, wiped half a build-server clean. So the basic task is to figure out if a file exists, and if so, let's delete it. But there are a few treacherous rapids on this river:

  • Everything is a file.

  • Scripts have real power only if they solve general tasks

  • To be general, we use variables

  • We often use -f force in scripts to avoid manual intervention

  • And also love -r recursive to make sure we create, copy and destroy in a timely fashion.

Consider the following scenario:

We have the file we want to delete: filesexists.json

This filename is stored in a variable

<host>:~/Documents/thisfolderexists filevariable="filesexists.json"

We also hava a path variable to make things really flexible

<host>:~/Documents/thisfolderexists pathtofile=".."

<host>:~/Documents/thisfolderexists ls $pathtofile

filesexists.json  history20170728  SE-Data-API.pem  thisfolderexists

So let's see if -e does what it is supposed to. Does the files exist?

<host>:~/Documents/thisfolderexists [ -e $pathtofile/$filevariable ]; echo $?


It does. Magic.

However, what would happen, if the file variable got accidentally be evaluated to nuffin'

<host>:~/Documents/thisfolderexists filevariable=""

<host>:~/Documents/thisfolderexists [ -e $pathtofile/$filevariable ]; echo $?


What? It is supposed to return with an error... And this is the beginning of the story how that entire folder got deleted by accident

An alternative could be to test specifically for what we understand to be a 'file'

<host>:~/Documents/thisfolderexists filevariable="filesexists.json"

<host>:~/Documents/thisfolderexists test -f $pathtofile/$filevariable; echo $?


So the file exists...

<host>:~/Documents/thisfolderexists filevariable=""

<host>:~/Documents/thisfolderexists test -f $pathtofile/$filevariable; echo $?


So this is not a file and maybe, we do not want to delete that entire directory

man test has the following to say:


       FILE exists and is block special


       FILE exists and is character special


       FILE exists and is a directory


       FILE exists


       FILE exists and is a regular file



       FILE exists and is a symbolic link (same as -L)

In Matplotlib, what does the argument mean in fig.add_subplot(111)?

I think this would be best explained by the following picture:

enter image description here

To initialize the above, one would type:

import matplotlib.pyplot as plt
fig = plt.figure()
fig.add_subplot(221)   #top left
fig.add_subplot(222)   #top right
fig.add_subplot(223)   #bottom left
fig.add_subplot(224)   #bottom right

dictionary update sequence element #0 has length 3; 2 is required

I was getting this error when I was updating the dictionary with the wrong syntax:

Try with these:


instead of


How can I remove the top and right axis in matplotlib?

Alternatively, this

def simpleaxis(ax):

seems to achieve the same effect on an axis without losing rotated label support.

(Matplotlib 1.0.1; solution inspired by this).

How to create EditText with cross(x) button at end of it?


EditText mSearchEditText = findViewById(;

public void afterTextChanged(Editable aEditable) {
    int clearIcon = android.R.drawable.ic_notification_clear_all;
    int searchIcon = android.R.drawable.ic_menu_search;
    if (aEditable == null || TextUtils.isEmpty(aEditable.toString())) {
        clearIcon = 0;
        searchIcon = android.R.drawable.ic_menu_search;
    } else {
        clearIcon = android.R.drawable.ic_notification_clear_all;
        searchIcon = 0;
    Drawable leftDrawable =  null;
    if (searchIcon != 0) {
        leftDrawable = getResources().getDrawable(searchIcon);
    Drawable rightDrawable = null;
    if (clearIcon != 0) {
        rightDrawable = getResources().getDrawable(clearIcon);

    mSearchEditText.setCompoundDrawablesWithIntrinsicBounds(leftDrawable, null, rightDrawable, null);

public boolean onTouch(View aView, MotionEvent aEvent) {
    if (aEvent.getAction() == MotionEvent.ACTION_UP){
        if (aEvent.getX() > ( mSearchEditText.getWidth() - 
    return false;

How do I generate random integers within a specific range in Java?

ThreadLocalRandom equivalent of class java.util.Random for multithreaded environment. Generating a random number is carried out locally in each of the threads. So we have a better performance by reducing the conflicts.

int rand = ThreadLocalRandom.current().nextInt(x,y);

x,y - intervals e.g. (1,10)

How to compile c# in Microsoft's new Visual Studio Code?

Intellisense does work for C# 6, and it's great.

For running console apps you should set up some additional tools:

  • ASP.NET 5; in Powershell: &{$Branch='dev';iex ((new-object net.webclient).DownloadString(''))}
  • Node.js including package manager npm.
  • The rest of required tools including Yeoman yo: npm install -g yo grunt-cli generator-aspnet bower
  • You should also invoke .NET Version Manager: c:\Users\Username\.dnx\bin\dnvm.cmd upgrade -u

Then you can use yo as wizard for Console Application: yo aspnet Choose name and project type. After that go to created folder cd ./MyNewConsoleApp/ and run dnu restore

To execute your program just type >run in Command Palette (Ctrl+Shift+P), or execute dnx . run in shell from the directory of your project.

What is the difference between `new Object()` and object literal notation?

2019 Update

I ran the same code as @rjloura on my OSX High Sierra 10.13.6 node version 10.13.0 and these are the results

console.log('Testing Array:');
for(var i=0; i<200000000; i++){var arr = []};

console.time('using new');
for(var i=0; i<200000000; i++){var arr = new Array};
console.timeEnd('using new');

console.log('Testing Object:');

for(var i=0; i<200000000; i++){var obj = {}};

console.time('using new');
for(var i=0; i<200000000; i++){var obj = new Object};
console.timeEnd('using new');

Testing Array:
using[]: 117.613ms
using new: 117.168ms
Testing Object:
using{}: 117.205ms
using new: 118.644ms

Unable to find velocity template resources

I faced the similar problem with intellij IDEA. you can use this

 VelocityEngine ve = new VelocityEngine();
    Properties props = new Properties();
    props.put("file.resource.loader.path", "/Users/Projects/Comparator/src/main/resources/");

    Template t = ve.getTemplate("helloworld.vm");
    VelocityContext context = new VelocityContext();

How to check if an element is off-screen

Depends on what your definition of "offscreen" is. Is that within the viewport, or within the defined boundaries of your page?

Using Element.getBoundingClientRect() you can easily detect whether or not your element is within the boundries of your viewport (i.e. onscreen or offscreen):

jQuery.expr.filters.offscreen = function(el) {
  var rect = el.getBoundingClientRect();
  return (
           (rect.x + rect.width) < 0 
             || (rect.y + rect.height) < 0
             || (rect.x > window.innerWidth || rect.y > window.innerHeight)

You could then use that in several ways:

// returns all elements that are offscreen

// boolean returned if element is offscreen

No log4j2 configuration file found. Using default configuration: logging only errors to the console

If you don't have the fortune of the log4j-1.2.jar on your classpath as Renko points out in his comment, you will only see the message no log4j2 configuration file found.

This is a problem if there is an error in your configuration file, as you will not be told where the problem lies upon start-up.

For instance if you have a log4j2.yaml file which log4j2 fails to process, because for example, you have not configured a YAML parser for your project, or your config is simply incorrect. You will encounter the no log4j2 configuration file found message, with no further information. This is the case even if you have a valid log4j2.xml file, as log4j2 will only attempt to process the first configuration file it finds.

I've found the best way to debug the problem is to explicitly state the configuration file you wish to use as per the command line argument mentioned above.


Hopefully this will help you pinpoint if the issue is actually caused by your classloader not finding the log4j2 configuration file or something else in your configuration.


You can also use the below property to change the default level of the status logger to get further information:


Bootstrap 3: Scroll bars

You need to use the overflow option, but with the following parameters:

.nav {

Use overflow-y:auto; so the scrollbar only appears when the content exceeds the maximum height.

If you use overflow-y:scroll, the scrollbar will always be visible - on all .nav - regardless if the content exceeds the maximum heigh or not.

Presumably you want something that adapts itself to the content rather then the the opposite.

Hope it may helpful

"Adaptive Server is unavailable or does not exist" error connecting to SQL Server from PHP

Bud, disable selinux or add the following to your RedHat/CentOS Server:

setsebool -P httpd_can_network_connect_db 1
setsebool -P httpd_can_network_connect 1

Best always!

Understanding the set() function

As an unordered collection type, set([8, 1, 6]) is equivalent to set([1, 6, 8]).

While it might be nicer to display the set contents in sorted order, that would make the repr() call more expensive.

Internally, the set type is implemented using a hash table: a hash function is used to separate items into a number of buckets to reduce the number of equality operations needed to check if an item is part of the set.

To produce the repr() output it just outputs the items from each bucket in turn, which is unlikely to be the sorted order.

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

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

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

$agent= 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.0.3705; .NET CLR 1.1.4322)';

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

Check if a value is an object in JavaScript

With function Array.isArray:

function isObject(o) {
  return o !== null && typeof o === 'object' && Array.isArray(o) === false;

Without function Array.isArray:

Just surprised how many upvotes for wrong answers
Only 1 answer passed my tests!!! Here I've created my simplified version:

function isObject(o) {
  return o instanceof Object && o.constructor === Object;

As for me, it's clear and simple, and just works! Here my tests:

console.log(isObject({}));             // Will return: true
console.log(isObject([]));             // Will return: false
console.log(isObject(null));           // Will return: false
console.log(isObject(/.*/));           // Will return: false
console.log(isObject(function () {})); // Will return: false

ONE MORE TIME: not all answers pass this tests !!!

In case you need to verify that object is instance of particular class you have to check constructor with your particular class, like:

function isDate(o) {
  return o instanceof Object && o.constructor === Date;

simple test:

var d = new Date();
console.log(isObject(d)); // Will return: false
console.log(isDate(d));   // Will return: true

As result, you will have strict and robust code!

In case you won't create functions like isDate, isError, isRegExp, etc you may consider option to use this generalized functions:

function isObject(o) {
  return o instanceof Object && typeof o.constructor === 'function';

it won't work correctly for all test cases mentioned earlier, but it's good enough for all objects (plain or constructed).

isObject won't work in case of Object.create(null) because of internal implementation of Object.create which is explained here but you can use isObject in more sophisticated implementation:

function isObject(o, strict = true) {
  if (o === null || o === undefined) {
    return false;
  const instanceOfObject = o instanceof Object;
  const typeOfObject = typeof o === 'object';
  const constructorUndefined = o.constructor === undefined;
  const constructorObject = o.constructor === Object;
  const typeOfConstructorObject = typeof o.constructor === 'function';
  let r;
  if (strict === true) {
    r = (instanceOfObject || typeOfObject) && (constructorUndefined || constructorObject);
  } else {
    r = (constructorUndefined || typeOfConstructorObject);
  return r;

There is already created package on npm v1 based on this implementation! And it works for all earlier described test cases!

Java BigDecimal: Round to the nearest whole value

If i go by Grodriguez's answer

System.out.println("" + value);
value = value.setScale(0, BigDecimal.ROUND_HALF_UP);
System.out.println("" + value);

This is the output

100.23 -> 100
100.77 -> 101

Which isn't quite what i want, so i ended up doing this..

System.out.println("" + value);
value = value.setScale(0, BigDecimal.ROUND_HALF_UP);
value = value.setScale(2, BigDecimal.ROUND_HALF_UP);
System.out.println("" + value);

This is what i get

100.23 -> 100.00
100.77 -> 101.00

This solves my problem for now .. : ) Thank you all.

Auto-size dynamic text to fill fixed size container

I had exactly the same problem with my website. I have a page that is displayed on a projector, on walls, big screens..

As I don't know the max size of my font, I re-used the plugin above of @GeekMonkey but incrementing the fontsize :

$.fn.textfill = function(options) {
        var defaults = { innerTag: 'span', padding: '10' };
        var Opts = jQuery.extend(defaults, options);

        return this.each(function() {
            var ourText = $(Opts.innerTag + ':visible:first', this);
            var fontSize = parseFloat(ourText.css('font-size'),10);
            var doNotTrepass = $(this).height()-2*Opts.padding ;
            var textHeight;

            do {
                ourText.css('font-size', fontSize);
                textHeight = ourText.height();
                fontSize = fontSize + 2;
            } while (textHeight < doNotTrepass );

How to convert WebResponse.GetResponseStream return into a string?

You should create a StreamReader around the stream, then call ReadToEnd.

You should consider calling WebClient.DownloadString instead.

Is it possible to set a custom font for entire of application?

I would like to improve weston's and Roger Huang's answers for over API 21 Android lollipop with theme "Theme.AppCompat".

Below Android 4.4

    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">

   <!-- Application theme. -->
   <style name="AppTheme" parent="AppBaseTheme">
       <item name="android:typeface">monospace</item>

Over(equal) API 5.0

    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">

   <!-- Application theme. -->
   <style name="AppTheme" parent="AppBaseTheme">
       <item name="android:textAppearance">@style/CustomTextAppearance</item>

   <style name="CustomTextAppearance">
       <item name="android:typeface">monospace</item>

And the FontsOverride util file is same as what in weston's answer. I have tested in these phones:

Nexus 5(android 5.1 Primary Android System)

ZTE V5(android 5.1 CM12.1)

XIAOMI note(android 4.4 MIUI6)

HUAWEI C8850(android 2.3.5 UNKNOWN)

Bootstrap fullscreen layout with 100% height

Here's an answer using the latest Bootstrap 4.0.0. This layout is easier using the flexbox and sizing utility classes that are all provided in Bootstrap 4. This layout is possible with very little extra CSS.

#mmenu_screen > .row {
    min-height: 100vh;

.flex-fill {
    flex:1 1 auto;

<div id="mmenu_screen" class="container-fluid main_container d-flex">
    <div class="row flex-fill">
        <div class="col-sm-6 h-100">
            <div class="row h-50">
                <div class="col-sm-12" id="mmenu_screen--book">
                    <!-- Button for booking -->
            <div class="row h-50">
                <div class="col-sm-12" id="mmenu_screen--information">
                    <!-- Button for information -->
        <div class="col-sm-6 mmenu_screen--direktaction flex-fill">
            <!-- Button for direktaction -->


The flex-fill and vh-100 classes are included in Bootstrap 4.1 (and later)