Programs & Examples On #Jplayer

jPlayer is the completely free and open source (GPL/MIT) media library written in JavaScript.

run program in Python shell

From the same folder, you can do:

import test

CodeIgniter -> Get current URL relative to base url

If url helper is loaded, use


will be better

Parser Error when deploy ASP.NET application

Interesting all the different scenarios..

In my case...I had uploaded my site to GoDaddy and was getting the Parser Error.

I resolved it by commenting out compilers under system.codedom in web.config. And also add a custom profile for publishing that would precompile during publishing.

    <!--GoDaddy does not compile!-->
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:1659;1699;1701" />
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:default /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />

The required anti-forgery form field "__RequestVerificationToken" is not present Error in user Registration

Sometimes you are writing a form action method with a result list. In this case, you cannot work with one action method. So you have to have two action methods with the same name. One with [HttpGet] and another with [HttpPost] attribute.

In your [HttpPost] action method, set [ValidateAntiForgeryToken] attribute and also put @Html.AntiForgeryToken() in your html form.

How do I automatically update a timestamp in PostgreSQL

You'll need to write an insert trigger, and possible an update trigger if you want it to change when the record is changed. This article explains it quite nicely:

CREATE OR REPLACE FUNCTION update_modified_column()   
    NEW.modified = now();
    RETURN NEW;   
$$ language 'plpgsql';

Apply the trigger like this:

CREATE TRIGGER update_customer_modtime BEFORE UPDATE ON customer FOR EACH ROW EXECUTE PROCEDURE  update_modified_column();

How to write to a JSON file in the correct format

To make this work on Ubuntu Linux:

  1. I installed the Ubuntu package ruby-json:

    apt-get install ruby-json
  2. I wrote the script in ${HOME}/rubybin/jsonDEMO

  3. $HOME/.bashrc included:


(On this occasion I also typed the above on the bash command line.)

Then it worked when I entered on the command line:


Convert MFC CString to integer

The canonical solution is to use the C++ Standard Library for the conversion. Depending on the desired return type, the following conversion functions are available: std::stoi, std::stol, or std::stoll (or their unsigned counterparts std::stoul, std::stoull).

The implementation is fairly straight forward:

int ToInt( const CString& str ) {
    return std::stoi( { str.GetString(), static_cast<size_t>( str.GetLength() ) } );

long ToLong( const CString& str ) {
    return std::stol( { str.GetString(), static_cast<size_t>( str.GetLength() ) } );

long long ToLongLong( const CString& str ) {
    return std::stoll( { str.GetString(), static_cast<size_t>( str.GetLength() ) } );

unsigned long ToULong( const CString& str ) {
    return std::stoul( { str.GetString(), static_cast<size_t>( str.GetLength() ) } );

unsigned long long ToULongLong( const CString& str ) {
    return std::stoull( { str.GetString(), static_cast<size_t>( str.GetLength() ) } );

All of these implementations report errors through exceptions (std::invalid_argument if no conversion could be performed, std::out_of_range if the converted value would fall out of the range of the result type). Constructing the temporary std::[w]string can also throw.

The implementations can be used for both Unicode as well as MBCS projects.

Convert unix time stamp to date in java

You can use SimlpeDateFormat to format your date like this:

long unixSeconds = 1372339860;
// convert seconds to milliseconds
Date date = new java.util.Date(unixSeconds*1000L); 
// the format of your date
SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss z"); 
// give a timezone reference for formatting (see comment at the bottom)
String formattedDate = sdf.format(date);

The pattern that SimpleDateFormat takes if very flexible, you can check in the javadocs all the variations you can use to produce different formatting based on the patterns you write given a specific Date.

  • Because a Date provides a getTime() method that returns the milliseconds since EPOC, it is required that you give to SimpleDateFormat a timezone to format the date properly acording to your timezone, otherwise it will use the default timezone of the JVM (which if well configured will anyways be right)

How do I select elements of an array given condition?

I like to use np.vectorize for such tasks. Consider the following:

>>> # Arrays
>>> x = np.array([5, 2, 3, 1, 4, 5])
>>> y = np.array(['f','o','o','b','a','r'])

>>> # Function containing the constraints
>>> func = np.vectorize(lambda t: t>1 and t<5)

>>> # Call function on x
>>> y[func(x)]
>>> array(['o', 'o', 'a'], dtype='<U1')

The advantage is you can add many more types of constraints in the vectorized function.

Hope it helps.

What's in an Eclipse .classpath/.project file?

Eclipse is a runtime environment for plugins. Virtually everything you see in Eclipse is the result of plugins installed on Eclipse, rather than Eclipse itself.

The .project file is maintained by the core Eclipse platform, and its goal is to describe the project from a generic, plugin-independent Eclipse view. What's the project's name? what other projects in the workspace does it refer to? What are the builders that are used in order to build the project? (remember, the concept of "build" doesn't pertain specifically to Java projects, but also to other types of projects)

The .classpath file is maintained by Eclipse's JDT feature (feature = set of plugins). JDT holds multiple such "meta" files in the project (see the .settings directory inside the project); the .classpath file is just one of them. Specifically, the .classpath file contains information that the JDT feature needs in order to properly compile the project: the project's source folders (that is, what to compile); the output folders (where to compile to); and classpath entries (such as other projects in the workspace, arbitrary JAR files on the file system, and so forth).

Blindly copying such files from one machine to another may be risky. For example, if arbitrary JAR files are placed on the classpath (that is, JAR files that are located outside the workspace and are referred-to by absolute path naming), the .classpath file is rendered non-portable and must be modified in order to be portable. There are certain best practices that can be followed to guarantee .classpath file portability.

Clear form fields with jQuery

Why you dont use document.getElementById("myId").reset(); ? this is the simple and pretty

Oracle REPLACE() function isn't handling carriage-returns & line-feeds

If the data in your database is POSTED from HTML form TextArea controls, different browsers use different New Line characters:

Firefox separates lines with CHR(10) only

Internet Explorer separates lines with CHR(13) + CHR(10)

Apple (pre-OSX) separates lines with CHR(13) only

So you may need something like:

set col_name = replace(replace(col_name, CHR(13), ''), CHR(10), '')

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

MySQL pivot table query with dynamic columns

I have a slightly different way of doing this than the accepted answer. This way you can avoid using GROUP_CONCAT which has a limit of 1024 characters and will not work if you have a lot of fields.

SET @sql = '';
    @sql := CONCAT(@sql,if(@sql='','',', '),temp.output)
         'MAX(IF(pa.fieldname = ''',
          ''', pa.fieldvalue, NULL)) AS ',
        ) as output
) as temp;

                    , p.description, ', @sql, ' 
                   FROM product p
                   LEFT JOIN product_additional AS pa 
                    ON =
                   GROUP BY');

PREPARE stmt FROM @sql;

@Html.DropDownListFor how to set default value

SelectListItem has a Selected property. If you are creating the SelectListItems dynamically, you can just set the one you want as Selected = true and it will then be the default.

SelectListItem defaultItem = new SelectListItem()
   Value = 1,
   Text = "Default Item",
   Selected = true

Submitting a form by pressing enter without a submit button

You could try also this

<INPUT TYPE="image" SRC="0piximage.gif" HEIGHT="0" WIDTH="0" BORDER="0">

You could include an image with width/height = 0 px

how to change the dist-folder path in angular-cli after 'ng build'

Beware: The correct answer is below. This no longer works

Create a file called .ember-cli in your project, and include in it these contents:

   "output-path": "./location/to/your/dist/"

Which is the correct C# infinite loop, for (;;) or while (true)?

To rehash a couple of old jokes:

  1. Don't use "for (;;) {}" — it makes the statement cry.
  2. Unless, of course, you "#define EVER ;;".

Sum all the elements java arraylist

Using Java 8 streams:

double sum =
    .mapToDouble(a -> a)


How is VIP swapping + CNAMEs better than IP swapping + A records?

A VIP swap is an internal change to Azure's routers/load balancers, not an external DNS change. They're just routing traffic to go from one internal [set of] server[s] to another instead. Therefore the DNS info for doesn't change at all. Therefore the change for people accessing via the IP bound to (and CNAME'd by you) will see the change as soon as the VIP swap is complete.

How to tell bash that the line continues on the next line

The character is a backslash \

From the bash manual:

The backslash character ‘\’ may be used to remove any special meaning for the next character read and for line continuation.

SQL Server tables: what is the difference between @, # and ##?


Creates a table that is only visible on and during that CONNECTION the same user who creates another connection will not be able to see table #t from the other connection.


Creates a temporary table visible to other connections. But the table is dropped when the creating connection is ended.

Read each line of txt file to new array element

If you don't need any special processing, this should do what you're looking for

$lines = file($filename, FILE_IGNORE_NEW_LINES);

Git: "Not currently on any branch." Is there an easy way to get back on a branch, while keeping the changes?

The following method may work:

git rebase HEAD master
git checkout master

This will rebase your current HEAD changes on top of the master. Then you can switch the branch.

Alternative way is to checkout the branch first:

git checkout master

Then Git should display SHA1 of your detached commits, then you can cherry pick them, e.g.

git cherry-pick YOURSHA1

Or you can also merge the latest one:

git merge YOURSHA1

To see all of your commits from different branches (to make sure you've them), run: git reflog.

How do I force Internet Explorer to render in Standards Mode and NOT in Quirks?

Sadly, they want us to use a tag to let their browser know what to do. Look at this documentation, it tell us to use:

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

and it should do.

Use Font Awesome Icons in CSS

You can try this example class. and find icon content here:

  #content h2:before {
    display: inline-block;
    font: normal normal normal 14px/1 FontAwesome;
    font-size: inherit;
    text-rendering: auto;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transform: translate(0, 0);
    content: "\f007";

"Error: Main method not found in class MyClass, please define the main method as..."

I feel the above answers miss a scenario where this error occurs even when your code has a main(). When you are using JNI that uses Reflection to invoke a method. During runtime if the method is not found, you will get a

java.lang.NoSuchMethodError: No virtual method

Javascript: how to validate dates in format MM-DD-YYYY?

You can simplify it somewhat by changing the first two lines of the function to this:

var matches = this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);

Or, just change the parameter to the RegExp constructor to be


How to run SQL script in MySQL?

mysql> source C:\Users\admin\Desktop\fn_Split.sql

Do not specify single quotes.

If the above command is not working, copy the file to c: drive and try again. as shown below,

mysql> source C:\fn_Split.sql

How do I spool to a CSV formatted file using SQLPLUS?

There is a problem using sqlplus to create csv files. If you want the column headers only once in the output and there are thousands or millions of rows, you cannot set pagesize large enough not to get a repeat. The solution is to start with pagesize = 50 and parse out the headers, then issue the select again with pagesize = 0 to get the data. See bash script below:


sqlplus -L logn/pswd@//${CONN}<<EOF >/dev/null
set pagesize 50;
set verify off;
set feedback off;
set long 99999;
set linesize 32767;
set trimspool on;
col object_ddl format A32000;
set colsep ,;
set underline off;
set headsep off;
spool ${ORD}${TABLE}.tmp;
select * from tblspc.${TABLE} where rownum < 2;
LINES=`wc -l ${ORD}${TABLE}.tmp | cut -f1 -d" "`
[ ${LINES} -le 3 ] && {
  echo "No Data Found in ${TABLE}."
[ ${LINES} -gt 3 ] && {
  cat ${ORD}${TABLE}.tmp | sed -e 's/ * / /g' -e 's/^ //' -e 's/ ,/,/g' -e 's/, /,/g' | tail -n +3 | head -n 1 > ./${ORD}${TABLE}.headers

sqlplus -L logn/pswd@//${CONN}<<EOF >/dev/null
set pagesize 0;
set verify off;
set feedback off;
set long 99999;
set linesize 32767;
set trimspool on;
col object_ddl format A32000;
set colsep ,;
set underline off;
set headsep off;
spool ${ORD}${TABLE}.tmp;
select * from tblspc.${TABLE};
LINES=`wc -l ${ORD}${TABLE}.tmp | cut -f1 -d" "`
[ ${LINES} -le 3 ] && {
  echo "No Data Found in ${TABLE}."
[ ${LINES} -gt 3 ] && {
  cat ${ORD}${TABLE}.headers > ${FOLDER}/${ORD}${TABLE}.csv
  cat ${ORD}${TABLE}.tmp | sed -e 's/ * / /g' -e 's/^ //' -e 's/ ,/,/g' -e 's/, /,/g' | tail -n +2 | head -n -1 >> ${FOLDER}/${ORD}${TABLE}.csv

Android device does not show up in adb list

I tried everything on this thread but nothing worked. My problem: my computer was charging the device when I was connecting the cable on, so I assumed the cable was working, but not. After I swap the cable, adb devices worked. The cable was the issue.

OpenCV get pixel channel value from Mat image

The below code works for me, for both accessing and changing a pixel value.

For accessing pixel's channel value :

for (int i = 0; i < image.cols; i++) {
    for (int j = 0; j < image.rows; j++) {
        Vec3b intensity =<Vec3b>(j, i);
        for(int k = 0; k < image.channels(); k++) {
            uchar col = intensity.val[k]; 

For changing a pixel value of a channel :

uchar pixValue;
for (int i = 0; i < image.cols; i++) {
    for (int j = 0; j < image.rows; j++) {
        Vec3b &intensity =<Vec3b>(j, i);
        for(int k = 0; k < image.channels(); k++) {
            // calculate pixValue
            intensity.val[k] = pixValue;


Source : Accessing pixel value

How to customize the background color of a UITableViewCell?

Create a view and set this as background view of the cell

UIView *lab = [[UIView alloc] initWithFrame:cell.frame];
            [lab setBackgroundColor:[UIColor grayColor]];
            cell.backgroundView = lab;
            [lab release];

c# dictionary one key many values

A .NET dictionary does only have a 1-to-1 relationship for keys and values. But that doesn't mean that a value can't be another array/list/dictionary.

I can't think of a reason to have a 1 to many relationship in a dictionary, but obviously there is one.

If you have different types of data that you want to store to a key, then that sounds like the ideal time to create your own class. Then you have a 1 to 1, but you have the value class storing more that 1 piece of data.

Visual Studio 2010 always thinks project is out of date, but nothing has changed

I'm on Visual Studio 2013 and just updated to the Windows 10 May 2019 update and compiling suddenly had to be redone every time, regardless of changes. Tried renaming the pch to ProjectName instead of TargetName, looked for missing files with the detailed log and that Python script, but in the end it was my time was not synced with MS's servers (by like milliseconds).

What resolved this for me was

  • "Adjust date and time" in the control panel
  • "Sync Now"

Now my projects don't need to be recompiled for no reason.

Android textview usage as label and value

You should implement a Custom List View, such that you define a Layout once and draw it for every row in the list view.

Dart: mapping a list (

tabs: [ { return Text(title);}).toList(), extra_widget],

tabs: { return Text(title);}).toList(),

It's working fine for me

android button selector

You can't achieve text size change with a state list drawable. To change text color and text size do this:

Text color

To change the text color, you can create color state list resource. It will be a separate resource located in res/color/ directory. In layout xml you have to set it as the value for android:textColor attribute. The color selector will then contain something like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
    <item android:state_pressed="true" android:color="@color/text_pressed" />
    <item android:color="@color/text_normal" />

Text size

You can't change the size of the text simply with resources. There's no "dimen selector". You have to do it in code. And there is no straightforward solution.

Probably the easiest solution might be utilizing View.onTouchListener() and handle the up and down events accordingly. Use something like this:

view.setOnTouchListener(new OnTouchListener() {

        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                // change text size to the "pressed value"
                return true;
            case MotionEvent.ACTION_UP:
                // change text size to the "normal value"
                return true;
                return false;

A different solution might be to extend the view and override the setPressed(Boolean) method. The method is internally called when the change of the pressed state happens. Then change the size of the text accordingly in the method call (don't forget to call the super).

How do I find out which computer is the domain controller in Windows programmatically?

With the most simple programming language: DOS batch


Swift Beta performance: sorting arrays

The main issue that is mentioned by others but not called out enough is that -O3 does nothing at all in Swift (and never has) so when compiled with that it is effectively non-optimised (-Onone).

Option names have changed over time so some other answers have obsolete flags for the build options. Correct current options (Swift 2.2) are:

-Onone // Debug - slow
-O     // Optimised
-O -whole-module-optimization //Optimised across files

Whole module optimisation has a slower compile but can optimise across files within the module i.e. within each framework and within the actual application code but not between them. You should use this for anything performance critical)

You can also disable safety checks for even more speed but with all assertions and preconditions not just disabled but optimised on the basis that they are correct. If you ever hit an assertion this means that you are into undefined behaviour. Use with extreme caution and only if you determine that the speed boost is worthwhile for you (by testing). If you do find it valuable for some code I recommend separating that code into a separate framework and only disabling the safety checks for that module.

Best way to increase heap size in catalina.bat file

If you look in your installation's bin directory you will see or .bat scripts. If you look in these you will see that they run a or setenv.bat script respectively, if it exists, to set environment variables. The relevant environment variables are described in the comments at the top of To use them create, for example, a file $CATALINA_HOME/bin/ with contents

export JAVA_OPTS="-server -Xmx512m"

For Windows you will need, in setenv.bat, something like

set JAVA_OPTS=-server -Xmx768m

Original answer here

After you run startup.bat, you can easily confirm the correct settings have been applied provided you have turned @echo on somewhere in your catatlina.bat file (a good place could be immediately after echo Using CLASSPATH: "%CLASSPATH%"):

enter image description here

selecting rows with id from another table

SELECT terms.*
FROM terms JOIN terms_relation ON id=term_id
WHERE taxonomy='categ'

Read and parse a Json File in C#

For finding the right path I'm using

   var pathToJson = Path.Combine("my","path","config","default.Business.Area.json");
   var r = new StreamReader(pathToJson);
   var myJson = r.ReadToEnd();

   // my/path/config/default.Business.Area.json 
   [...] do parsing here 

Path.Combine uses the Path.PathSeparator and it checks whether the first path has already a separator at the end so it will not duplicate the separators. Additionally, it checks whether the path elements to combine have invalid chars.


JavaScript - populate drop down list with array

You'll need to loop through your array elements, create a new DOM node for each and append it to your object.

var select = document.getElementById("selectNumber"); 
var options = ["1", "2", "3", "4", "5"]; 

for(var i = 0; i < options.length; i++) {
    var opt = options[i];
    var el = document.createElement("option");
    el.textContent = opt;
    el.value = opt;

Live example

Echo off but messages are displayed

Save this as *.bat file and see differences

:: print echo command and its output
echo 1

:: does not print echo command just its output
@echo 2

:: print dir command but not its output
dir > null

:: does not print dir command nor its output
@dir c:\ > null

:: does not print echo (and all other commands) but print its output
@echo off
echo 3

@echo on
REM this comment will appear in console if 'echo off' was not set

@set /p pressedKey=Press any key to exit

SecurityException during executing jnlp file (Missing required Permissions manifest attribute in main jar)

JAR File Manifest Attributes for Security

The JAR file manifest contains information about the contents of the JAR file, including security and configuration information.

Add the attributes to the manifest before the JAR file is signed.
See Modifying a Manifest File in the Java Tutorial for information on adding attributes to the JAR manifest file.

Permissions Attribute

The Permissions attribute is used to verify that the permissions level requested by the RIA when it runs matches the permissions level that was set when the JAR file was created.

Use this attribute to help prevent someone from re-deploying an application that is signed with your certificate and running it at a different privilege level. Set this attribute to one of the following values:

  • sandbox - runs in the security sandbox and does not require additional permissions.

  • all-permissions - requires access to the user's system resources.

Changes to Security Slider:

The following changes to Security Slider were included in this release(7u51):

  • Block Self-Signed and Unsigned applets on High Security Setting
  • Require Permissions Attribute for High Security Setting
  • Warn users of missing Permissions Attributes for Medium Security Setting

For more information, see Java Control Panel documentation.

enter image description here


Manifest-Version: 1.0
Ant-Version: Apache Ant 1.8.3
Created-By: 1.7.0_51-b13 (Oracle Corporation)
Trusted-Only: true
Class-Path: lib/plugin.jar
Permissions: sandbox
Application-Name: summary-applet

Why are there two ways to unstage a file in Git?

I'm surprised noone mentioned the git reflog (

# git reflog
<find the place before your staged anything>
# git reset HEAD@{1}

The reflog is a git history that not only tracks the changes to the repo, but also tracks the user actions (Eg. pull, checkout to different branch, etc) and allows to undo those actions. So instead of unstaging the file that was mistakingly staged, where you can revert to the point where you didn't stage the files.

This is similar to git reset HEAD <file> but in certain cases may be more granular.

Sorry - not really answering your question, but just pointing yet another way to unstage files that I use quite often (I for one like answers by Ryan Stewart and waldyrious very much.) ;) I hope it helps.

What is the advantage of using REST instead of non-REST HTTP?

It's written down in the Fielding dissertation. But if you don't want to read a lot:

  • increased scalability (due to stateless, cache and layered system constraints)
  • decoupled client and server (due to stateless and uniform interface constraints)
    • reusable clients (client can use general REST browsers and RDF semantics to decide which link to follow and how to display the results)
    • non breaking clients (clients break only by application specific semantics changes, because they use the semantics instead of some API specific knowledge)

Conditional formatting based on another cell's value

One more example:

If you have Column from A to D, and need to highlight the whole line (e.g. from A to D) if B is "Complete", then you can do it following:

"Custom formula is":  =$B:$B="Completed" 
Background Color:     red 
Range:                A:D

Of course, you can change Range to A:T if you have more columns.

If B contains "Complete", use search as following:

"Custom formula is":  =search("Completed",$B:$B) 
Background Color:     red 
Range:                A:D

How to use "like" and "not like" in SQL MSAccess for the same field?

what's the problem with:

field like "*AA*" and field not like "*BB*"

it should be working.

Could you post some example of your data?

Can we call the function written in one JavaScript in another JS file?

The answer above has an incorrect assumption that the order of inclusion of the files matter. As the alertNumber function is not called until the alertOne function is called. As long as both files are included by time alertOne is called the order of the files does not matter:


<script type="text/javascript" src="file1.js"></script>
<script type="text/javascript" src="file2.js"></script>
<script type="text/javascript">
    alertOne( );


// File1.js
function alertNumber( n ) {
    alert( n );
// File2.js
function alertOne( ) {
    alertNumber( "one" );
// Inline
alertOne( ); // No errors

Or it can be ordered like the following:


<script type="text/javascript" src="file2.js"></script>
<script type="text/javascript" src="file1.js"></script>
<script type="text/javascript">
    alertOne( );


// File2.js
function alertOne( ) {
    alertNumber( "one" );
// File1.js
function alertNumber( n ) {
    alert( n );
// Inline
alertOne( ); // No errors

But if you were to do this:


<script type="text/javascript" src="file2.js"></script>
<script type="text/javascript">
    alertOne( );
<script type="text/javascript" src="file1.js"></script>


// File2.js
function alertOne( ) {
    alertNumber( "one" );
// Inline
alertOne( ); // Error: alertNumber is not defined
// File1.js
function alertNumber( n ) {
    alert( n );

It only matters about the variables and functions being available at the time of execution. When a function is defined it does not execute or resolve any of the variables declared within until that function is then subsequently called.

Inclusion of different script files is no different from the script being in that order within the same file, with the exception of deferred scripts:

<script type="text/javascript" src="myscript.js" defer="defer"></script>

then you need to be careful.

How do I find an array item with TypeScript? (a modern, easier way)

You could just use underscore library.

Install it:

   npm install underscore --save
   npm install @types/underscore --save-dev

Import it

   import _ = require('underscore');

Use it

    var x = _.filter(
      [{ "id": 1 }, { "id": -2 }, { "id": 3 }],
      myObj => < 0)

jQuery using append with effects

When you append to the div, hide it and show it with the argument "slow".


How to I say Is Not Null in VBA

Use Not IsNull(Fields!W_O_Count.Value)

socket.error: [Errno 48] Address already in use

Simple one line command to get rid of it, type below command in terminal,

ps -a

This will list out all process, checkout which is being used by Python and type bellow command in terminal,

kill -9 (processID) 

For example kill -9 33178

What was the strangest coding standard rule that you were forced to follow?

I've had a lot of stupid rules, but not a lot that I considered downright strange.

The sillyiest was on a NASA job I worked back in the early 90's. This was a huge job, with well over 100 developers on it. The experienced developers who wrote the coding standards decided that every source file should begin with a four letter acronym, and the first letter had to stand for the group that was responsible for the file. This was probably a great idea for the old FORTRAN 77 projects they were used to.

However, this was an Ada project, with a nice hierarchal library structure, so it made no sense at all. Every directory was full of files starting with the same letter, followed by 3 more nonsense leters, an underscore, and then part of the file name that mattered. All the Ada packages had to start with this same five-character wart. Ada "use" clauses were not allowed either (arguably a good thing under normal circumstances), so that meant any reference to any identifier that wasn't local to that source file also had to include this useless wart. There probably should have been an insurrection over this, but the entire project was staffed by junior programmers and fresh from college new hires (myself being the latter).

A typical assignment statement (already verbose in Ada) would end up looking something like this:

NABC_The_Package_Name.X := NABC_The_Package_Name.X + 

Fortunately they were at least enlightened enough to allow us more than 80 columns! Still, the facility wart was hated enough that it became boilerplate code at the top of everyone's source files to use Ada "renames" to get rid of the wart. There'd be one rename for each imported ("withed") package. Like this:

package Package_Name renames NABC_Package_Name;
package Some_Other_Package_Name renames CXYZ_Some_Other_Package_Name;
--// Repeated in this vein for an average of 10 lines or so

What the more creative among us took to doing was trying to use the wart to make an acutally sensible (or silly) package name. (I know what you are thinking, but explitives were not allowed and shame on you! That's disgusting). For example, I was in the Common code group, and I needed to make a package to interface with the Workstation group. After a brainstorming session with the Workstation guy, we decided to name our packages so that someone needing both would have to write:

with CANT_Interface_Package;
with WONT_Interface_Package;

How to get and set the current web page scroll position?

There are some inconsistencies in how browsers expose the current window scrolling coordinates. Google Chrome on Mac and iOS seems to always return 0 when using document.documentElement.scrollTop or jQuery's $(window).scrollTop().

However, it works consistently with:

// horizontal scrolling amount

// vertical scrolling amount

Converting PKCS#12 certificate into PEM using OpenSSL

There is a free and open-source GUI tool KeyStore Explorer to work with crypto key containers. Using it you can export a certificate or private key into separate files or convert the container into another format (jks, pem, p12, pkcs12, etc)

enter image description here

How to put attributes via XElement

Add XAttribute in the constructor of the XElement, like

new XElement("Conn", new XAttribute("Server", comboBox1.Text));

You can also add multiple attributes or elements via the constructor

new XElement("Conn", new XAttribute("Server", comboBox1.Text), new XAttribute("Database", combobox2.Text));

or you can use the Add-Method of the XElement to add attributes

XElement element = new XElement("Conn");
XAttribute attribute = new XAttribute("Server", comboBox1.Text);

Mapping two integers to one, in a unique and deterministic way

How about something much simpler: Given two numbers, A and B let str be the concatenation: 'A' + ';' + 'B'. Then let the output be hash(str). I know that this is not a mathematical answer, but a simple python (which has an in built hash function) script should do the job.

How to change FontSize By JavaScript?

JavaScript is case sensitive.

So, if you want to change the font size, you have to go: = "25px";

Java URLConnection Timeout

You can manually force disconnection by a Thread sleep. This is an example:

URLConnection con = url.openConnection();
new Thread(new InterruptThread(con)).start();


public class InterruptThread implements Runnable {

    HttpURLConnection con;
    public InterruptThread(HttpURLConnection con) {
        this.con = con;

    public void run() {
        try {
            Thread.sleep(5000); // or Thread.sleep(con.getConnectTimeout())
        } catch (InterruptedException e) {

        System.out.println("Timer thread forcing to quit connection");

How do I get the XML SOAP request of an WCF Web service request?

Simply we can trace the request message as.

OperationContext context = OperationContext.Current;

if (context != null && context.RequestContext != null)


Message msg = context.RequestContext.RequestMessage;

string reqXML = msg.ToString();


How to convert date format to DD-MM-YYYY in C#

DateTime s1 = System.Convert.ToDateTime(textbox.Trim());
        DateTime date = (s1);
        String frmdt = date.ToString("dd-MM-yyyy"); 

will work

How to send a header using a HTTP request through a curl call?

In anaconda envirement through windows the commands should be: GET, for ex:


Post or Patch the data for ex:

curl.exe -X PATCH -H "Content-Type: application/json" -d '{\"rating\":\"2\"}' 

PS: Add backslash for json data to avoid this type of error => Failed to decode JSON object: Expecting value: line 1 column 1 (char 0)

and use curl.exe instead of curl only to avoid this problem:

Invoke-WebRequest : Cannot bind parameter 'Headers'. Cannot convert the "Content-Type: application/json" value of type
"System.String" to type "System.Collections.IDictionary".
At line:1 char:48
+ ... 0.1:5000/books/8 -X PATCH -H "Content-Type: application/json" -d '{\" ...
+                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (:) [Invoke-WebRequest], ParameterBindingException
    + FullyQualifiedErrorId : CannotConvertArgumentNoMessage,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

How to make a loop in x86 assembly language?

Yet another method is using the LOOP instruction:

mov  cx, 3

    ; Your loop content

    loop myloop

The loop instruction automatically decrements cx, and only jumps if cx != 0. There are also LOOPE, and LOOPNE variants, if you want to do some additional check for your loop to break out early.

If you want to modify cx during your loop, make sure to push it onto the stack before the loop content, and pop it off after:

mov  cx, 3

    push cx
    ; Your loop content
    pop  cx

    loop myloop

Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly

I made an application based on Mike Hadlow application: AsmSpy.

My app is a WPF app with GUI and can be download from my home webserver: AsmSpyPlus.exe.

Code is available at: GitHub

Gui Sample

Placing Unicode character in CSS content value

Why don't you just save/serve the CSS file as UTF-8?

nav a:hover:after {
    content: "?";

If that's not good enough, and you want to keep it all-ASCII:

nav a:hover:after {
    content: "\2193";

The general format for a Unicode character inside a string is \000000 to \FFFFFF – a backslash followed by six hexadecimal digits. You can leave out leading 0 digits when the Unicode character is the last character in the string or when you add a space after the Unicode character. See the spec below for full details.

Relevant part of the CSS2 spec:

Third, backslash escapes allow authors to refer to characters they cannot easily put in a document. In this case, the backslash is followed by at most six hexadecimal digits (0..9A..F), which stand for the ISO 10646 ([ISO10646]) character with that number, which must not be zero. (It is undefined in CSS 2.1 what happens if a style sheet does contain a character with Unicode codepoint zero.) If a character in the range [0-9a-fA-F] follows the hexadecimal number, the end of the number needs to be made clear. There are two ways to do that:

  1. with a space (or other white space character): "\26 B" ("&B"). In this case, user agents should treat a "CR/LF" pair (U+000D/U+000A) as a single white space character.
  2. by providing exactly 6 hexadecimal digits: "\000026B" ("&B")

In fact, these two methods may be combined. Only one white space character is ignored after a hexadecimal escape. Note that this means that a "real" space after the escape sequence must be doubled.

If the number is outside the range allowed by Unicode (e.g., "\110000" is above the maximum 10FFFF allowed in current Unicode), the UA may replace the escape with the "replacement character" (U+FFFD). If the character is to be displayed, the UA should show a visible symbol, such as a "missing character" glyph (cf. 15.2, point 5).

  • Note: Backslash escapes are always considered to be part of an identifier or a string (i.e., "\7B" is not punctuation, even though "{" is, and "\32" is allowed at the start of a class name, even though "2" is not).
    The identifier "te\st" is exactly the same identifier as "test".

Comprehensive list: Unicode Character 'DOWNWARDS ARROW' (U+2193).

Why am I getting an OPTIONS request instead of a GET request?

I don't believe jQuery will just naturally do a JSONP request when given a URL like that. It will, however, do a JSONP request when you tell it what argument to use for a callback:

$.get("", function(data) {

It's entirely up to the receiving script to make use of that argument (which doesn't have to be called "jsoncallback"), so in this case the function will never be called. But, since you stated you just want the script at to execute, that would make it.

angular js unknown provider

I was forgetting to inject the file that held my services altogether. Remember to do this when initializing your app module:

angular.module('myApp', ['', ... ]);

How to call a button click event from another method

Usually the better way is to trigger an event (click) instead of calling the method directly.

List directory tree structure in python?

Here you can find code with output like this:

V .
|-> V folder1
|   |-> V folder2
|   |   |-> V folder3
|   |   |   |-> file3.txt
|   |   |-> file2.txt
|   |-> V folderX
|   |-> file1.txt

res.sendFile absolute path

An alternative that hasn't been listed yet that worked for me is simply using path.resolve with either separate strings or just one with the whole path:

// comma separated
app.get('/', function(req, res) {
    res.sendFile( path.resolve('src', 'app', 'index.html') );


// just one string with the path
app.get('/', function(req, res) {
    res.sendFile( path.resolve('src/app/index.html') );

(Node v6.10.0)

Idea sourced from

How do I declare class-level properties in Objective-C?

I'm using this solution:

@interface Model
+ (int) value;
+ (void) setValue:(int)val;

@implementation Model
static int value;
+ (int) value
{ @synchronized(self) { return value; } }
+ (void) setValue:(int)val
{ @synchronized(self) { value = val; } }

And i found it extremely useful as a replacement of Singleton pattern.

To use it, simply access your data with dot notation:

Model.value = 1;
NSLog(@"%d = value", Model.value);

How do I find the MySQL my.cnf location

You can also run this command.

mysql --help | grep cnf

How can I add comments in MySQL?

"A comment for a column can be specified with the COMMENT option. The comment is displayed by the SHOW CREATE TABLE and SHOW FULL COLUMNS statements. This option is operational as of MySQL 4.1. (It is allowed but ignored in earlier versions.)"

As an example

-- Table structure for table 'accesslog'

CREATE TABLE accesslog (
aid int(10) NOT NULL auto_increment COMMENT 'unique ID for each access entry', 
title varchar(255) default NULL COMMENT 'the title of the page being accessed',
path varchar(255) default NULL COMMENT 'the local path of teh page being accessed',

How to check for Is not Null And Is not Empty string in SQL server?

Just check: where value > '' -- not null and not empty

-- COLUMN CONTAINS A VALUE (ie string not null and not empty) :
-- (note: "<>" gives a different result than ">")
select iif(null    > '', 'true', 'false'); -- false (null)
select iif(''      > '', 'true', 'false'); -- false (empty string)
select iif(' '     > '', 'true', 'false'); -- false (space)
select iif('    '  > '', 'true', 'false'); -- false (tab)
select iif('
'                  > '', 'true', 'false'); -- false (newline)
select iif('xxx'   > '', 'true', 'false'); -- true
-- NOTE - test that tab and newline is processed as expected:
select 'x   x' -- tab
select 'x

x' -- newline

Get first line of a shell command's output

I would use:

awk 'FNR <= 1' file_*.txt

As @Kusalananda points out there are many ways to capture the first line in command line but using the head -n 1 may not be the best option when using wildcards since it will print additional info. Changing 'FNR == i' to 'FNR <= i' allows to obtain the first i lines.

For example, if you have n files named file_1.txt, ... file_n.txt:

awk 'FNR <= 1' file_*.txt


But with head wildcards print the name of the file:

head -1 file_*.txt

==> file_1.csv <==
==> file_n.csv <==

Get year, month or day from numpy datetime64

Anon's answer works great for me, but I just need to modify the statement for days


days = dates - dates.astype('datetime64[M]') + 1


days = dates.astype('datetime64[D]') - dates.astype('datetime64[M]') + 1

How to get input text value on click in ReactJS

There are two ways to go about doing this.

  1. Create a state in the constructor that contains the text input. Attach an onChange event to the input box that updates state each time. Then onClick you could just alert the state object.

  2. handleClick: function() { alert(this.refs.myInput.value); },

Stylesheet not updating

In my case, since I could not append a cache busting timestamp to the css url it turned out that I had to manually refresh the application pool in IIS 7.5.7600.

Every other avenue was pursued, right down to disabling the caching entirely for the site and also for the local browser (like ENTIRELY disabled for both), still didn't do the trick. Also "restarting" the website did nothing.

Same position as me? [Site Name] > "Application Pool" > "Recycle" is your last resort...

How do I prevent a form from being resized by the user?

Set FormBorderStyle to 'FixedDialog'


Chrome's remote debugging (USB debugging) not working for Samsung Galaxy S3 running android 4.3

In case it helps anyone I will post what worked for me.

I had to plug my S3 into a direct USB port of my PC for it to prompt me to accept the RSA signature. I had my S3 plugged into a hub before then.

Now the S3 is detected when using both the direct USB port of the PC and via the hub.

NOTE - You may need to also run adb devices from the command line to get your S3 to re-request permission.

D:\apps\android-sdk-windows\platform-tools>adb devices
List of devices attached
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
9283759342847566        unauthorized

...accept signature on phone...

D:\apps\android-sdk-windows\platform-tools>adb devices
List of devices attached
9283759342847566        device

How to pass parameters on onChange of html select

Just in case someone is looking for a React solution without having to download addition dependancies you could write:

<select onChange={this.changed(this)}>
   <option value="Apple">Apple</option>
   <option value="Android">Android</option>                

  return e => {

Make sure to bind the changed() function in the constructor like:

this.changed = this.changed.bind(this);

Casting objects in Java

in some cases we can’t provide guarantee for the type of elements or objects present inside our collection or wise, at the time of retrieval compulsory we should perform type casting otherwise we will get compile time error.

Arrays are always type safe that is we can provide the guarantee for the type of elements present inside array. to achieve type safety we have to use typecasting.

Perform a Shapiro-Wilk Normality Test

Set the data as a vector and then place in the function.

convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

The answer with highest votes (I have not enough reputation to add comment there) suggests to comment out the MVG line, but have in mind this:


ImageMagick supports ".svg/.mvg" files which means that attackers can craft code in a scripting language, e.g. MSL (Magick Scripting Language) and MVG (Magick Vector Graphics), upload it to a server disguised as an image file and force the software to run malicious commands on the server side as described above. For example adding the following commands in a file and uploading it to a webserver that uses a vulnerable ImageMagick version will result in running the command "ls -la" on the server.


push graphic-context viewbox 0 0 640 480 fill 'url("|ls "-la)' pop graphic-context


Any version below 7.0.1-2 or 6.9.4-0 is potentially vulnerable and affected parties should as soon as possible upgrade to the latest ImageMagick version.


Basic calculator in Java

public class SwitchExample {

    public static void main(String[] args) throws Exception {

        System.out.println("1. Addition");
        System.out.println("2. Multiplication");
        System.out.println("3. Substraction");
        System.out.println("4. Division");
        System.out.println("0. Exit");

        System.out.println("Enter Your Choice :::::::  ");
        BufferedReader br = new BufferedReader(new InputStreamReader(;
        String str = br.readLine();

        int usrChoice = Integer.parseInt(str);

        switch (usrChoice) {
            case 1:
            case 2:
            case 3:
            case 4:

            case 0:
                System.out.println("Thank you.....");

                System.out.println("Invalid Value");


public static void doAddition() throws Exception {
    System.out.println("******* Enter in Addition Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Addition : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(;
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Addition : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(;
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 + no2;

    System.out.println("Addition of " + no1 + " and " + no2 + " is ::::::: " + result);

public static void doSubstraction() throws Exception {
    System.out.println("******* Enter in Substraction Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Substraction : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(;
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Substraction : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(;
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 - no2;

    System.out.println("Substraction of " + no1 + " and " + no2 + " is ::::::: " + result);

public static void doMultiplication() throws Exception {
    System.out.println("******* Enter in Multiplication Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Multiplication : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(;
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Multiplication : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(;
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 * no2;

    System.out.println("Multiplication of " + no1 + " and " + no2 + " is ::::::: " + result);

public static void doDivision() throws Exception {
    System.out.println("******* Enter in Dividion Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Dividion : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(;
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Dividion : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(;
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    float result = no1 / no2;

    System.out.println("Division of " + no1 + " and " + no2 + " is ::::::: " + result);


Create a map with clickable provinces/states using SVG, HTML/CSS, ImageMap

I have been using makeaclickablemap for my province maps for some time now and it turned out to be a really good fit.

Setting "checked" for a checkbox with jQuery

For jQuery 1.6+

$('.myCheckbox').prop('checked', true);
$('.myCheckbox').prop('checked', false);

For jQuery 1.5.x and below

$('.myCheckbox').attr('checked', true);
$('.myCheckbox').attr('checked', false);

To check,


OAuth 2.0 Authorization Header

For those looking for an example of how to pass the OAuth2 authorization (access token) in the header (as opposed to using a request or body parameter), here is how it's done:

Authorization: Bearer 0b79bab50daca910b000d4f1a2b675d604257e42

How can I solve "Non-static method xxx:xxx() should not be called statically in PHP 5.4?

I solved this with one code line, as follow: In file index.php, at your template root, after this code line:

defined( '_JEXEC' ) or die( 'Restricted access' );

paste this line: ini_set ('display_errors', 'Off');

Don't worry, be happy...

posted by Jenio.

CodeIgniter: How to get Controller, Action, URL information

If you using $this->uri->segment , if urls rewriting rules change, segments name matching will be lost.

call javascript function on hyperlink click

Use the onclick HTML attribute.

The onclick event handler captures a click event from the users’ mouse button on the element to which the onclick attribute is applied. This action usually results in a call to a script method such as a JavaScript function [...]

How to remove last n characters from every element in the R vector

Similar to @Matthew_Plourde using gsub

However, using a pattern that will trim to zero characters i.e. return "" if the original string is shorter than the number of characters to cut:

cs <- c("foo_bar","bar_foo","apple","beer","so","a")
gsub('.{0,3}$', '', cs)
# [1] "foo_" "bar_" "ap"   "b"    ""    ""

Difference is, {0,3} quantifier indicates 0 to 3 matches, whereas {3} requires exactly 3 matches otherwise no match is found in which case gsub returns the original, unmodified string.

N.B. using {,3} would be equivalent to {0,3}, I simply prefer the latter notation.

See here for more information on regex quantifiers:

Write bytes to file

This example reads 6 bytes into a byte array and writes it to another byte array. It does an XOR operation with the bytes so that the result written to the file is the same as the original starting values. The file is always 6 bytes in size, since it writes at position 0.

using System;
using System.IO;

namespace ConsoleApplication1
    class Program
        static void Main()
        byte[] b1 = { 1, 2, 4, 8, 16, 32 };
        byte[] b2 = new byte[6];
        byte[] b3 = new byte[6];
        byte[] b4 = new byte[6];

        FileStream f1;
        f1 = new FileStream("test.txt", FileMode.Create, FileAccess.Write);

        // write the byte array into a new file
        f1.Write(b1, 0, 6);

        // read the byte array
        f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Read);

        f1.Read(b2, 0, 6);

        // make changes to the byte array
        for (int i = 1; i < b2.Length; i++)
            b2[i] = (byte)(b2[i] ^ (byte)10); //xor 10

        f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Write);
        // write the new byte array into the file
        f1.Write(b2, 0, 6);

        f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Read);

        // read the byte array
        f1.Read(b3, 0, 6);

        // make changes to the byte array
        for (int i = 1; i < b3.Length; i++)
            b4[i] = (byte)(b3[i] ^ (byte)10); //xor 10

        f1 = new FileStream("test.txt", FileMode.Open, FileAccess.Write);

        // b4 will have the same values as b1
        f1.Write(b4, 0, 6);

Convert datetime value into string

Try this:

  • 10 char on date field based on full date yyyy-MM-dd.

  • 8 char on time field based on full time hh:mm:ss.

It depends on the format you want it. normally you can use script above and you can concat another field or string as you want it.

Because actually date and time field tread as string if you read it. But of course you will got error while update or insert it.

Shell script to capture Process ID and kill it if exist

This works good for me.

PID=`ps -eaf | grep syncapp | grep -v grep | awk '{print $2}'`
if [[ "" !=  "$PID" ]]; then
  echo "killing $PID"
  kill -9 $PID

SQL to search objects, including stored procedures, in Oracle

i reached this question while trying to find all procedures which use a certain table

Oracle SQL Developer offers this capability, as pointed out in this article :

From the View menu, choose Find DB Object. Choose a DB connection. Enter the name of the table. At Object Types, keep only functions, procedures and packages. At Code section, check All source lines.

enter image description here

Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat

I was able to solve the problem in my react native project by simply adding

configurations {
        all*.exclude group: '', module: 'support-compat'
        all*.exclude group: '', module: 'support-core-ui'

at the end of my android\app\build.gradle file

Android Studio shortcuts like Eclipse

Yes you can go to File -> Settings -> Editor -> Auto Import -> Java and make the following changes:

1.change Insert imports on paste value to All in drop down option.

2.markAdd unambigious imports on the fly option as checked.(For Window or linux user)

On a Mac, do the same thing in Android Studio -> Preferences

3.You can also use Eclipse shortcut key in Android Studio just go to in Android Studio

File -> Settings -> KeyMap -> Keymaps dropdown Option. Select from them


Assign result of dynamic sql to variable

You should try this while getting SEQUENCE value in a variable from the dynamic table.

DECLARE @temp table (#temp varchar (MAX));
DECLARE @SeqID nvarchar(150);
DECLARE @Name varchar(150); 

SET @Name = (Select Name from table)
SET @SeqID = 'SELECT NEXT VALUE FOR '+ @Name + '_Sequence'
insert @temp exec (@SeqID)

SET @SeqID = (select * from @temp )


(1 row(s) affected)

Scanner is skipping nextLine() after using next() or nextFoo()?

public static void main(String[] args) {
        Scanner scan = new Scanner(;
        int i = scan.nextInt();
        double d = scan.nextDouble();
        String s = scan.nextLine();

        System.out.println("String: " + s);
        System.out.println("Double: " + d);
        System.out.println("Int: " + i);

How do I display a MySQL error in PHP for a long query that depends on the user input?

I use the following to turn all error reporting on for MySQLi


*NOTE: don't use this in a production environment.

Finding diff between current and last version

You can do it this way too:

Compare with the previous commit

git diff --name-status HEAD~1..HEAD

Compare with the current and previous two commits

git diff --name-status HEAD~2..HEAD

How to Make A Chevron Arrow Using CSS?

You can use the before or after pseudo-element and apply some CSS to it. There are various ways. You can add both before and after, and rotate and position each of them to form one of the bars. An easier solution is adding two borders to just the before element and rotate it using transform: rotate.

Scroll down for a different solution that uses an actual element instead of the pseuso elements

In this case, I've added the arrows as bullets in a list and used em sizes to make them size properly with the font of the list.

ul {_x000D_
    list-style: none;_x000D_
ul.big {_x000D_
    list-style: none;_x000D_
    font-size: 300%_x000D_
li::before {_x000D_
    position: relative;_x000D_
    /* top: 3pt; Uncomment this to lower the icons as requested in comments*/_x000D_
    content: "";_x000D_
    display: inline-block;_x000D_
    /* By using an em scale, the arrows will size with the font */_x000D_
    width: 0.4em;_x000D_
    height: 0.4em;_x000D_
    border-right: 0.2em solid black;_x000D_
    border-top: 0.2em solid black;_x000D_
    transform: rotate(45deg);_x000D_
    margin-right: 0.5em;_x000D_
/* Change color */_x000D_
li:hover {_x000D_
  color: red; /* For the text */_x000D_
li:hover::before {_x000D_
  border-color: red; /* For the arrow (which is a border) */_x000D_
<ul class="big">_x000D_

Of course you don't need to use before or after, you can apply the same trick to a normal element as well. For the list above it is convenient, because you don't need additional markup. But sometimes you may want (or need) the markup anyway. You can use a div or span for that, and I've even seen people even recycle the i element for 'icons'. So that markup could look like below. Whether using <i> for this is right is debatable, but you can use span for this as well to be on the safe side.

/* Default icon formatting */_x000D_
i {_x000D_
  display: inline-block;_x000D_
  font-style: normal;_x000D_
  position: relative;_x000D_
/* Additional formatting for arrow icon */_x000D_
i.arrow {_x000D_
    /* top: 2pt; Uncomment this to lower the icons as requested in comments*/_x000D_
    width: 0.4em;_x000D_
    height: 0.4em;_x000D_
    border-right: 0.2em solid black;_x000D_
    border-top: 0.2em solid black;_x000D_
    transform: rotate(45deg);_x000D_
And so you can have an <i class="arrow" title="arrow icon"></i> in your text._x000D_
This arrow is <i class="arrow" title="arrow icon"></i> used to be deliberately lowered slightly on request._x000D_
I removed that for the general public <i class="arrow" title="arrow icon"></i> but you can uncomment the line with 'top' <i class="arrow" title="arrow icon"></i> to restore that effect.

If you seek more inspiration, make sure to check out this awesome library of pure CSS icons by Nicolas Gallagher. :)

What are and

Simple example

Shamelessly adapted from: and tested on Ubuntu 14.04 Automake 1.14.1.

dist_doc_DATA =

Some doc.

AC_INIT([automake_hello_world], [1.0], [[email protected]])
AM_INIT_AUTOMAKE([-Wall -Werror foreign])


bin_PROGRAMS = autotools_hello_world
autotools_hello_world_SOURCES = main.c


#include <config.h>
#include <stdio.h>

int main (void) {
  puts ("Hello world from " PACKAGE_STRING);
  return 0;


autoreconf --install
mkdir build
cd build
sudo make install
sudo make uninstall

This outputs:

Hello world from automake_hello_world 1.0


  • autoreconf --install generates several template files which should be tracked by Git, including It only needs to be run the first time.

  • make install installs:

    • the binary to /usr/local/bin
    • to /usr/local/share/doc/automake_hello_world

On GitHub for you to try it out.

Rails - passing parameters in link_to

link_to "+ Service", controller_action_path(:account_id =>

If it is still not working check the path:

$ rake routes

Changing background color of ListView items on Android

The best tutorial on this can be found here.

Key sections:

  1. Surely call view.setSelected(true) in onItemClick, otherwise the you can't see the selected item background
  2. Preserve the order of states in your selector otherwise you'll see unpredictable behavior in background colors (state_selected followed by state_pressed)

Get Path from another app (WhatsApp)

You can try this it will help for you.You can't get path from WhatsApp directly.If you need an file path first copy file and send new file path. Using the code below

 public static String getFilePathFromURI(Context context, Uri contentUri) {
    String fileName = getFileName(contentUri);
    if (!TextUtils.isEmpty(fileName)) {
        File copyFile = new File(TEMP_DIR_PATH  + fileName+".jpg");
        copy(context, contentUri, copyFile);
        return copyFile.getAbsolutePath();
    return null;

public static String getFileName(Uri uri) {
    if (uri == null) return null;
    String fileName = null;
    String path = uri.getPath();
    int cut = path.lastIndexOf('/');
    if (cut != -1) {
        fileName = path.substring(cut + 1);
    return fileName;

public static void copy(Context context, Uri srcUri, File dstFile) {
    try {
        InputStream inputStream = context.getContentResolver().openInputStream(srcUri);
        if (inputStream == null) return;
        OutputStream outputStream = new FileOutputStream(dstFile);
        IOUtils.copy(inputStream, outputStream);
    } catch (IOException e) {
    } catch (Exception e) {

Then IOUtils class is like below

public class IOUtils {

private static final int BUFFER_SIZE = 1024 * 2;

private IOUtils() {
    // Utility class.

public static int copy(InputStream input, OutputStream output) throws Exception, IOException {
    byte[] buffer = new byte[BUFFER_SIZE];

    BufferedInputStream in = new BufferedInputStream(input, BUFFER_SIZE);
    BufferedOutputStream out = new BufferedOutputStream(output, BUFFER_SIZE);
    int count = 0, n = 0;
    try {
        while ((n =, 0, BUFFER_SIZE)) != -1) {
            out.write(buffer, 0, n);
            count += n;
    } finally {
        try {
        } catch (IOException e) {
            Log.e(e.getMessage(), e.toString());
        try {
        } catch (IOException e) {
            Log.e(e.getMessage(), e.toString());
    return count;


Rebuild all indexes in a Database

Also a good script, although my laptop ran out of memory, but this was on a very large table

USE [<mydatabasename>]

--/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--Arguments             Data Type               Description
--------------          ------------            ------------
--@FillFactor           [int]                   Specifies a percentage that indicates how full the Database Engine should make the leaf level
--                                              of each index page during index creation or alteration. The valid inputs for this parameter
--                                              must be an integer value from 1 to 100 The default is 0.
--                                              For more information, see

--@PadIndex             [varchar](3)            Specifies index padding. The PAD_INDEX option is useful only when FILLFACTOR is specified,
--                                              because PAD_INDEX uses the percentage specified by FILLFACTOR. If the percentage specified
--                                              for FILLFACTOR is not large enough to allow for one row, the Database Engine internally
--                                              overrides the percentage to allow for the minimum. The number of rows on an intermediate
--                                              index page is never less than two, regardless of how low the value of fillfactor. The valid
--                                              inputs for this parameter are ON or OFF. The default is OFF.
--                                              For more information, see

--@SortInTempDB         [varchar](3)            Specifies whether to store temporary sort results in tempdb. The valid inputs for this
--                                              parameter are ON or OFF. The default is OFF.
--                                              For more information, see

--@OnlineRebuild        [varchar](3)            Specifies whether underlying tables and associated indexes are available for queries and data
--                                              modification during the index operation. The valid inputs for this parameter are ON or OFF.
--                                              The default is OFF.
--                                              Note: Online index operations are only available in Enterprise edition of Microsoft
--                                                      SQL Server 2005 and above.
--                                              For more information, see

--@DataCompression      [varchar](4)            Specifies the data compression option for the specified index, partition number, or range of
--                                              partitions. The options  for this parameter are as follows:
--                                                  > NONE - Index or specified partitions are not compressed.
--                                                  > ROW  - Index or specified partitions are compressed by using row compression.
--                                                  > PAGE - Index or specified partitions are compressed by using page compression.
--                                              The default is NONE.
--                                              Note: Data compression feature is only available in Enterprise edition of Microsoft
--                                                      SQL Server 2005 and above.
--                                              For more information about compression, see

--@MaxDOP               [int]                   Overrides the max degree of parallelism configuration option for the duration of the index
--                                              operation. The valid input for this parameter can be between 0 and 64, but should not exceed
--                                              number of processors available to SQL Server.
--                                              For more information, see
--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -*/

-- Ensure a USE <databasename> statement has been executed first.


DECLARE  @Version                           [numeric] (18, 10)
        ,@SQLStatementID                    [int]
        ,@CurrentTSQLToExecute              [nvarchar](max)
        ,@FillFactor                        [int]        = 100 -- Change if needed
        ,@PadIndex                          [varchar](3) = N'OFF' -- Change if needed
        ,@SortInTempDB                      [varchar](3) = N'OFF' -- Change if needed
        ,@OnlineRebuild                     [varchar](3) = N'OFF' -- Change if needed
        ,@LOBCompaction                     [varchar](3) = N'ON' -- Change if needed
        ,@DataCompression                   [varchar](4) = N'NONE' -- Change if needed
        ,@MaxDOP                            [int]        = NULL -- Change if needed
        ,@IncludeDataCompressionArgument    [char](1);

IF OBJECT_ID(N'TempDb.dbo.#Work_To_Do') IS NOT NULL
    DROP TABLE #Work_To_Do
      [sql_id] [int] IDENTITY(1, 1)
                     PRIMARY KEY ,
      [tsql_text] [varchar](1024) ,
      [completed] [bit]

SET @Version = CAST(LEFT(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)), CHARINDEX('.', CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128))) - 1) + N'.' + REPLACE(RIGHT(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)), LEN(CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128))) - CHARINDEX('.', CAST(SERVERPROPERTY(N'ProductVersion') AS [nvarchar](128)))), N'.', N'') AS [numeric](18, 10))

IF @DataCompression IN (N'PAGE', N'ROW', N'NONE')
    AND (
        @Version >= 10.0
        AND SERVERPROPERTY(N'EngineEdition') = 3
    SET @IncludeDataCompressionArgument = N'Y'

IF @IncludeDataCompressionArgument IS NULL
    SET @IncludeDataCompressionArgument = N'N'

INSERT INTO #Work_To_Do ([tsql_text], [completed])
        WHEN @PadIndex IS NULL
            THEN 'PAD_INDEX =' + SPACE(1) + CASE i.[is_padded]
                    WHEN 1
                        THEN 'ON'
                    WHEN 0
                        THEN 'OFF'
        ELSE 'PAD_INDEX =' + SPACE(1) + @PadIndex
        END + CASE
        WHEN @FillFactor IS NULL
            THEN ', FILLFACTOR =' + SPACE(1) + CONVERT([varchar](3), REPLACE(i.[fill_factor], 0, 100))
        ELSE ', FILLFACTOR =' + SPACE(1) + CONVERT([varchar](3), @FillFactor)
        END + CASE
        WHEN @SortInTempDB IS NULL
            THEN ''
        ELSE ', SORT_IN_TEMPDB =' + SPACE(1) + @SortInTempDB
        END + CASE
        WHEN @OnlineRebuild IS NULL
            THEN ''
        ELSE ', ONLINE =' + SPACE(1) + @OnlineRebuild
        END + ', STATISTICS_NORECOMPUTE =' + SPACE(1) + CASE st.[no_recompute]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + ', ALLOW_ROW_LOCKS =' + SPACE(1) + CASE i.[allow_row_locks]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + ', ALLOW_PAGE_LOCKS =' + SPACE(1) + CASE i.[allow_page_locks]
        WHEN 0
            THEN 'OFF'
        WHEN 1
            THEN 'ON'
        END + CASE
        WHEN @IncludeDataCompressionArgument = N'Y'
            THEN CASE
                    WHEN @DataCompression IS NULL
                        THEN ''
                    ELSE ', DATA_COMPRESSION =' + SPACE(1) + @DataCompression
        ELSE ''
        END + CASE
        WHEN @MaxDop IS NULL
            THEN ''
        ELSE ', MAXDOP =' + SPACE(1) + CONVERT([varchar](2), @MaxDOP)
        END + SPACE(1) + ')'
FROM [sys].[tables] t1
INNER JOIN [sys].[indexes] i ON t1.[object_id] = i.[object_id]
    AND i.[index_id] > 0
    AND i.[type] IN (1, 2)
INNER JOIN [sys].[stats] AS st WITH (NOLOCK) ON st.[object_id] = t1.[object_id]
    AND st.[name] = i.[name]

SELECT @SQLStatementID = MIN([sql_id])
FROM #Work_To_Do
WHERE [completed] = 0

    SELECT @CurrentTSQLToExecute = [tsql_text]
    FROM #Work_To_Do
    WHERE [sql_id] = @SQLStatementID

    PRINT @CurrentTSQLToExecute

    EXEC [sys].[sp_executesql] @CurrentTSQLToExecute

    UPDATE #Work_To_Do
    SET [completed] = 1
    WHERE [sql_id] = @SQLStatementID

    SELECT @SQLStatementID = MIN([sql_id])
    FROM #Work_To_Do
    WHERE [completed] = 0

Convert NSDate to String in iOS Swift

you get the detail information from Apple Dateformatter Document.If you want to set the dateformat for your dateString, see this link , the detail dateformat you can get here for e.g , do like

let formatter = DateFormatter()
// initially set the format based on your datepicker date / server String
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"

let myString = formatter.string(from: Date()) // string purpose I add here 
// convert your string to date
let yourDate = myString)
//then again set the date format whhich type of output you need
formatter.dateFormat = "dd-MMM-yyyy"
// again convert your date to string
let myStringafd = formatter.string(from: yourDate!)


you get the output as

enter image description here

R object identification

I usually start out with some combination of:

sapply(obj, class)
sapply(obj, attributes)

as appropriate based on what's revealed. For example, try with:

obj <- data.frame(a=1:26, b=letters)
obj <- list(a=1:26, b=letters, c=list(d=1:26, e=letters))
obj <- lm(dist ~ speed, data=cars)


If obj is an S3 or S4 object, you can also try methods or showMethods, showClass, etc. Patrick Burns' R Inferno has a pretty good section on this (sec #7).

EDIT: Dirk and Hadley mention str(obj) in their answers. It really is much better than any of the above for a quick and even detailed peek into an object.

How do I make a Docker container start automatically on system boot?

1) First of all, you must enable docker service on boot

$ sudo systemctl enable docker

2) Then if you have docker-compose .yml file add restart: always or if you have docker container add restart=always like this:

docker run --restart=always and run docker container

Make sure

If you manually stop a container, its restart policy is ignored until the Docker daemon restarts or the container is manually restarted.

see this restart policy on Docker official page

3) If you want start docker-compose, all of the services run when you reboot your system So you run below command only once

$ docker-compose up -d

Export DataBase with MySQL Workbench with INSERT statements

For older versions:

Open MySQL Workbench > Home > Manage Import / Export (Right bottom) / Select Required DB > Advance Exports Options Tab >Complete Insert [Checked] > Start Export.

For 6.1 and beyond, thanks to ryandlf:

Click the management tab (beside schemas) and choose Data Export.

Entity framework left join

It might be a bit of an overkill, but I wrote an extension method, so you can do a LeftJoin using the Join syntax (at least in method call notation):

    person => person.Id,
    phoneNumber => phoneNumber.PersonId,
    (person, phoneNumber) => new
            Person = person,
            PhoneNumber = phoneNumber?.Number

My code does nothing more than adding a GroupJoin and a SelectMany call to the current expression tree. Nevertheless, it looks pretty complicated because I have to build the expressions myself and modify the expression tree specified by the user in the resultSelector parameter to keep the whole tree translatable by LINQ-to-Entities.

public static class LeftJoinExtension
    public static IQueryable<TResult> LeftJoin<TOuter, TInner, TKey, TResult>(
        this IQueryable<TOuter> outer,
        IQueryable<TInner> inner,
        Expression<Func<TOuter, TKey>> outerKeySelector,
        Expression<Func<TInner, TKey>> innerKeySelector,
        Expression<Func<TOuter, TInner, TResult>> resultSelector)
        MethodInfo groupJoin = typeof (Queryable).GetMethods()
                                                 .Single(m => m.ToString() == "System.Linq.IQueryable`1[TResult] GroupJoin[TOuter,TInner,TKey,TResult](System.Linq.IQueryable`1[TOuter], System.Collections.Generic.IEnumerable`1[TInner], System.Linq.Expressions.Expression`1[System.Func`2[TOuter,TKey]], System.Linq.Expressions.Expression`1[System.Func`2[TInner,TKey]], System.Linq.Expressions.Expression`1[System.Func`3[TOuter,System.Collections.Generic.IEnumerable`1[TInner],TResult]])")
                                                 .MakeGenericMethod(typeof (TOuter), typeof (TInner), typeof (TKey), typeof (LeftJoinIntermediate<TOuter, TInner>));
        MethodInfo selectMany = typeof (Queryable).GetMethods()
                                                  .Single(m => m.ToString() == "System.Linq.IQueryable`1[TResult] SelectMany[TSource,TCollection,TResult](System.Linq.IQueryable`1[TSource], System.Linq.Expressions.Expression`1[System.Func`2[TSource,System.Collections.Generic.IEnumerable`1[TCollection]]], System.Linq.Expressions.Expression`1[System.Func`3[TSource,TCollection,TResult]])")
                                                  .MakeGenericMethod(typeof (LeftJoinIntermediate<TOuter, TInner>), typeof (TInner), typeof (TResult));

        var groupJoinResultSelector = (Expression<Func<TOuter, IEnumerable<TInner>, LeftJoinIntermediate<TOuter, TInner>>>)
                                      ((oneOuter, manyInners) => new LeftJoinIntermediate<TOuter, TInner> {OneOuter = oneOuter, ManyInners = manyInners});

        MethodCallExpression exprGroupJoin = Expression.Call(groupJoin, outer.Expression, inner.Expression, outerKeySelector, innerKeySelector, groupJoinResultSelector);

        var selectManyCollectionSelector = (Expression<Func<LeftJoinIntermediate<TOuter, TInner>, IEnumerable<TInner>>>)
                                           (t => t.ManyInners.DefaultIfEmpty());

        ParameterExpression paramUser = resultSelector.Parameters.First();

        ParameterExpression paramNew = Expression.Parameter(typeof (LeftJoinIntermediate<TOuter, TInner>), "t");
        MemberExpression propExpr = Expression.Property(paramNew, "OneOuter");

        LambdaExpression selectManyResultSelector = Expression.Lambda(new Replacer(paramUser, propExpr).Visit(resultSelector.Body), paramNew, resultSelector.Parameters.Skip(1).First());

        MethodCallExpression exprSelectMany = Expression.Call(selectMany, exprGroupJoin, selectManyCollectionSelector, selectManyResultSelector);

        return outer.Provider.CreateQuery<TResult>(exprSelectMany);

    private class LeftJoinIntermediate<TOuter, TInner>
        public TOuter OneOuter { get; set; }
        public IEnumerable<TInner> ManyInners { get; set; }

    private class Replacer : ExpressionVisitor
        private readonly ParameterExpression _oldParam;
        private readonly Expression _replacement;

        public Replacer(ParameterExpression oldParam, Expression replacement)
            _oldParam = oldParam;
            _replacement = replacement;

        public override Expression Visit(Expression exp)
            if (exp == _oldParam)
                return _replacement;

            return base.Visit(exp);

Repeat rows of a data.frame

try using for example

rep(1:4, each = N) 

as an index

Disable a Button

For those who Googled "disable a button" but may have more nuanced use cases:

Disable with visual effect: As others have said, this will prevent the button from being pressed and the system will automatically make it look disabled:

yourButton.isEnabled = false 

Disable without visual effect: Are you using a button in a case where it should look normal but not behave likes button by reacting to touches? Try this!

yourButton.userInteractionEnabled = false

Hide without disabling: This approach hides the button without disabling it (invisible but can still be tapped):

 yourButton.alpha = 0.0

Remove: This will remove the view entirely:


Tap something behind a button: Have two buttons stacked and you want the top button to temporarily act like it's not there? If you won't need the top button again, remove it. If you will need it again, try condensing its height or width to 0!

Can't bind to 'ngModel' since it isn't a known property of 'input'

You need to import the FormsModule

Open app.module.ts

and add line

import { FormsModule } from '@angular/forms';


imports: [

How to allow only one radio button to be checked?

Simply give them the same name:

<input type="radio" name="radAnswer" />

if statements matching multiple values

If you have a List, you can use .Contains(yourObject), if you're just looking for it existing (like a where). Otherwise look at Linq .Any() extension method.

Trying to check if username already exists in MySQL database using PHP

change your query to like.

$username = mysql_real_escape_string($username); // escape string before passing it to query.
$query = mysql_query("SELECT username FROM Users WHERE username='".$username."'");

However, MySQL is deprecated. You should instead use MySQLi or PDO

Script for rebuilding and reindexing the fragmented index?

I have found the following script is very good at maintaining indexes, you can have this scheduled to run nightly or whatever other timeframe you wish.

Android Material: Status bar color won't change


Solution for naughty LOLLIPOP


hello i had rly big problem with having that darker than was my color... so this is solution to avoid that shadow behind status bar from solution with TranslucentStatus...

so in all of your java activity you need this:


and at your styles.xml you need to set background color (this color will be your status bar color):

<style name="AppCompat" parent="Theme.AppCompat">
    <item name="android:colorBackground">@color/YOUR_STATUS_BAR_COLOR</item>

and at all your layouts you need to add layout which will be your background:


of course if you would like use @color/just name... you need to set that at colors.xml:

<color name="YOUR_STATUS_BAR_COLOR">#cf031c</color>
<color name="YOUR_BACKGROUND_COLOR">#383838</color>

here is whole process how we did done that: Whats the right approach to create or change color of a status bar?

How to refresh Gridview after pressed a button in

Adding the GridView1.DataBind() to the button click event did not work for me. However, adding it to the SqlDataSource1_Updated event did though.

Protected Sub SqlDataSource1_Updated(sender As Object, e As SqlDataSourceStatusEventArgs) Handles SqlDataSource1.Updated
End Sub

how to convert String into Date time format in JAVA?

With SimpleDateFormat. And steps are -

  1. Create your date pattern string
  2. Create SimpleDateFormat Object
  3. And parse with it.
  4. It will return Date Object.

Python Linked List

I based this additional function on Nick Stinemates

def add_node_at_end(self, data):
    new_node = Node()
    node = self.curr_node
    while node:
        if == None:
   = new_node
   = None
   = data
        node =

The method he has adds the new node at the beginning while I have seen a lot of implementations which usually add a new node at the end but whatever, it is fun to do.

How to consume a webApi from Web API to store result in database?

In this tutorial is explained how to consume a web api with C#, in this example a console application is used, but you can also use another web api to consume of course.

You should have a look at the HttpClient

HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://localhost/yourwebapi");

Make sure your requests ask for the response in JSON using the Accept header like this:

new MediaTypeWithQualityHeaderValue("application/json"));

Now comes the part that differs from the tutorial, make sure you have the same objects as the other WEB API, if not, then you have to map the objects to your own objects. ASP.NET will convert the JSON you receive to the object you want it to be.

HttpResponseMessage response = client.GetAsync("api/yourcustomobjects").Result;
if (response.IsSuccessStatusCode)
    var yourcustomobjects = response.Content.ReadAsAsync<IEnumerable<YourCustomObject>>().Result;
    foreach (var x in yourcustomobjects)
        //Call your store method and pass in your own object
    //Something has gone wrong, handle it here

please note that I use .Result for the case of the example. You should consider using the async await pattern here.

Pythonic way to find maximum value and its index in a list?

I made some big lists. One is a list and one is a numpy array.

import numpy as np
import random
for i in range(0,100000000):

Using jupyter notebook's %%time function I can compare the speed of various things.

2 seconds:


54.6 seconds:


6.71 seconds:


103 ms:


numpy's arrays are crazy fast.

Transform hexadecimal information to binary using a Linux command

As @user786653 suggested, use the xxd(1) program:

xxd -r -p input.txt output.bin

Using variables inside strings

In C# 6 you can use string interpolation:

string name = "John";
string result = $"Hello {name}";

The syntax highlighting for this in Visual Studio makes it highly readable and all of the tokens are checked.

Why can templates only be implemented in the header file?

Although standard C++ has no such requirement, some compilers require that all function and class templates need to be made available in every translation unit they are used. In effect, for those compilers, the bodies of template functions must be made available in a header file. To repeat: that means those compilers won't allow them to be defined in non-header files such as .cpp files

There is an export keyword which is supposed to mitigate this problem, but it's nowhere close to being portable.

How to load all modules in a folder?

Look at the pkgutil module from the standard library. It will let you do exactly what you want as long as you have an file in the directory. The file can be empty.

How do I get the HTML code of a web page in PHP?

you can use the DomDocument method to get an individual HTML tag level variable too

$homepage = file_get_contents('');
$doc = new DOMDocument;
$titles = $doc->getElementsByTagName('h3');
echo $titles->item(0)->nodeValue;

Going from MM/DD/YYYY to DD-MMM-YYYY in java

formatter = new SimpleDateFormat("dd-MMM-yy");

Responsive font size in CSS

 h1 { font-size: 2.25em; } 
 h2 { font-size: 1.875em; }
 h3 { font-size: 1.5em; }
 h4 { font-size: 1.125em; }
 h5 { font-size: 0.875em; }
 h6 { font-size: 0.75em; }

How to pull remote branch from somebody else's repo

git remote add coworker git://path/to/coworkers/repo.git
git fetch coworker
git checkout --track coworker/foo

This will setup a local branch foo, tracking the remote branch coworker/foo. So when your co-worker has made some changes, you can easily pull them:

git checkout foo
git pull

Response to comments:

Cool :) And if I'd like to make my own changes to that branch, should I create a second local branch "bar" from "foo" and work there instead of directly on my "foo"?

You don't need to create a new branch, even though I recommend it. You might as well commit directly to foo and have your co-worker pull your branch. But that branch already exists and your branch foo need to be setup as an upstream branch to it:

git branch --set-upstream foo colin/foo

assuming colin is your repository (a remote to your co-workers repository) defined in similar way:

git remote add colin git://path/to/colins/repo.git

How to get ID of button user just clicked?

With pure javascript:

var buttons = document.getElementsByTagName("button");
var buttonsCount = buttons.length;
for (var i = 0; i <= buttonsCount; i += 1) {
    buttons[i].onclick = function(e) {

How can I indent multiple lines in Xcode?

? + [ and ? + ] are the equivalents to shift+tab in Xcode.

What does SQL clause "GROUP BY 1" mean?

It means to group by the first column regardless of what it's called. You can do the same with ORDER BY.

Remove all whitespace from C# string with regex

No need for regex. This will also remove tabs, newlines etc

var newstr = String.Join("",str.Where(c=>!char.IsWhiteSpace(c)));

WhiteSpace chars : 0009 , 000a , 000b , 000c , 000d , 0020 , 0085 , 00a0 , 1680 , 180e , 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 , 2008 , 2009 , 200a , 2028 , 2029 , 202f , 205f , 3000.

How does the communication between a browser and a web server take place?

It depends on the web server, but if you're wondering what it looks like from the client side, just install Live Headers and Firebug for firefox. With the net tab in firebug and live headers open, it should be clear exactly how the two interact.

For a more in-depth look at the actual data going back and forth, use wireshark.

How to enable named/bind/DNS full logging?

I usually expand each log out into it's own channel and then to a separate log file, certainly makes things easier when you are trying to debug specific issues. So my logging section looks like the following:

logging {
    channel default_file {
        file "/var/log/named/default.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel general_file {
        file "/var/log/named/general.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel database_file {
        file "/var/log/named/database.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel security_file {
        file "/var/log/named/security.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel config_file {
        file "/var/log/named/config.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel resolver_file {
        file "/var/log/named/resolver.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel xfer-in_file {
        file "/var/log/named/xfer-in.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel xfer-out_file {
        file "/var/log/named/xfer-out.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel notify_file {
        file "/var/log/named/notify.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel client_file {
        file "/var/log/named/client.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel unmatched_file {
        file "/var/log/named/unmatched.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel queries_file {
        file "/var/log/named/queries.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel network_file {
        file "/var/log/named/network.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel update_file {
        file "/var/log/named/update.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel dispatch_file {
        file "/var/log/named/dispatch.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel dnssec_file {
        file "/var/log/named/dnssec.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;
    channel lame-servers_file {
        file "/var/log/named/lame-servers.log" versions 3 size 5m;
        severity dynamic;
        print-time yes;

    category default { default_file; };
    category general { general_file; };
    category database { database_file; };
    category security { security_file; };
    category config { config_file; };
    category resolver { resolver_file; };
    category xfer-in { xfer-in_file; };
    category xfer-out { xfer-out_file; };
    category notify { notify_file; };
    category client { client_file; };
    category unmatched { unmatched_file; };
    category queries { queries_file; };
    category network { network_file; };
    category update { update_file; };
    category dispatch { dispatch_file; };
    category dnssec { dnssec_file; };
    category lame-servers { lame-servers_file; };

Hope this helps.

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

It's interesting things with IDE (IntelliJ in this case):

  • if you leave default, i.e. don't declare spring-boot-starter-tomcat as provided, a spring-boot-maven-plugin (SBMP) put tomcat's jars to your war -> and you'll probably get errors deploying this war to container (there could be a versions conflict)

  • else you'll get classpath with no compile dependency on tomcat-embed (SBMP will build executable war/jar with provided deps included anyway)

    • intelliJ honestly doesn't see provided deps at runtime (they are not in classpath) when you run its Spring Boot run configuration.
    • and with no tomcat-embed you can't run Spring-Boot with embedded servlet container.

There is some tricky workaround: put Tomcat's jars to classpath of your idea-module via UI: File->Project Structure->(Libraries or Modules/Dependencies tab) .

  • tomcat-embed-core
  • tomcat-embed-el
  • tomcat-embed-websocket
  • tomcat-embed-logging-juli

Better solution for maven case

Instead of adding module dependencies in Idea, it is better to declare maven profile with compile scope of spring-boot-starter-tomcat library.


while spring-boot-starter-tomcat was declared provided in <dependencies/>, making this profile active in IDE or CLI (mvn -Pembed-tomcat ...) allow you to launch build with embedded tomcat.

Difference between "move" and "li" in MIPS assembly language

The move instruction copies a value from one register to another. The li instruction loads a specific numeric value into that register.

For the specific case of zero, you can use either the constant zero or the zero register to get that:

move $s0, $zero
li   $s0, 0

There's no register that generates a value other than zero, though, so you'd have to use li if you wanted some other number, like:

li $s0, 12345678

Can you change what a symlink points to after it is created?

Yes, you can!

$ ln -sfn source_file_or_directory_name softlink_name

How to get memory usage at runtime using C++?

I was looking for a Linux app to measure maximum memory used. valgrind is an excellent tool, but was giving me more information than I wanted. tstime seemed to be the best tool I could find. It measures "highwater" memory usage (RSS and virtual). See this answer.

Shell Scripting: Using a variable to define a path

Don't use spaces...


SPTH = '/home/Foo/Documents/Programs/ShellScripts/Butler'



Setting selection to Nothing when programming Excel

You can simply use this code at the end. (Do not use False)

Application.CutCopyMode = True

CSS: Creating textured backgrounds

You should try slicing the image if possible into a smaller piece which could be repeated. I have sliced that image to a 101x101px image.

BG Tile


  background-image: url(SO_texture_bg.jpg);

But in some cases, we wouldn't be able to slice the image to a smaller one. In that case, I would use the whole image. But you could also use the CSS3 methods like what Mustafa Kamal had mentioned.

Wish you good luck.

Convert all first letter to upper case, rest lower for each word

There's a couple of ways to go about converting the first char of a string to upper case.

The first way is to create a method that simply caps the first char and appends the rest of the string using a substring:

public string UppercaseFirst(string s)
        return char.ToUpper(s[0]) + s.Substring(1);

The second way (which is slightly faster) is to split the string into a char array and then re-build the string:

public string UppercaseFirst(string s)
        char[] a = s.ToCharArray();
        a[0] = char.ToUpper(a[0]);
        return new string(a);

tqdm in Jupyter Notebook prints new progress bars repeatedly

To complete oscarbranson's answer: it's possible to automatically pick console or notebook versions of progress bar depending on where it's being run from:

from tqdm.autonotebook import tqdm

More info can be found here

How to compare strings in sql ignoring case?

before comparing the two or more strings first execute the following commands

alter session set NLS_COMP=LINGUISTIC;
alter session set NLS_SORT=BINARY_CI;

after those two statements executed then you may compare the strings and there will be case insensitive.for example you had two strings s1='Apple' and s2='apple', if yow want to compare the two strings before executing the above statements then those two strings will be treated as two different strings but when you compare the strings after the execution of the two alter statements then those two strings s1 and s2 will be treated as the same string

reasons for using those two statements

We need to set NLS_COMP=LINGUISTIC and NLS_SORT=BINARY_CI in order to use 10gR2 case insensitivity. Since these are session modifiable, it is not as simple as setting them in the initialization parameters. We can set them in the initialization parameters but they then only affect the server and not the client side.

Difference between "git add -A" and "git add ."

Both git add . and git add -A will stage all new, modified and deleted files in the newer versions of Git.

The difference is that git add -A stages files in "higher, current and subdirectories" that belong to your working Git repository. But doing a git add . only stages files in the current directory and subdirectories following it (not the files lying outside, i.e., higher directories).

Here's an example:


If your current working directory is /my-repo, and you do rm rootfile.txt, then cd subfolder, followed by git add ., then it will not stage the deleted file. But doing git add -A will certainly stage this change no matter where you perform the command from.

How to create Custom Ratings bar in Android

When creating a custom rating bar that displays a solid gradient line running on a SeekBar-like track, rather than stars, I also encountered a problem related to the vertical centering of the background (track drawable). This is the flawed drawable code I used originally (which generated the problem), as suggested by Android developer and other StackOverflow entries:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="">

    <item android:id="@android:id/secondaryProgress">
            android:scaleWidth="100%" />

    <item android:id="@android:id/progress" >
        <clip android:clipOrientation="horizontal" android:gravity="left" >


The problem here is the first item, which relates to the background of the custom RatingBar. Many entries will tell you to set the layout_minHeight feature to some large value to avoid a vertical spatial disconnect between the thumb and its track. This was not the solution for me - when viewed on a tablet, the background was still drawing to its smaller phone-based size - so the track was consistently positioned well above the center of the RatingBar track. The solution is to remove this entry in the RatingBar drawable, so it now looks like this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="">

    <item android:id="@android:id/secondaryProgress">
            android:scaleWidth="100%" />

    <item android:id="@android:id/progress" >
        <clip android:clipOrientation="horizontal" android:gravity="left" >


Then, in the style definition of the custom RatingBar, set the layout_background to the the track drawable. Mine looks like this:

<style name="styleRatingBar" parent="@android:style/Widget.RatingBar">
    <item name="android:indeterminateOnly">false</item>
    <item name="android:background">@drawable/seekbar_track</item>
    <item name="android:progressDrawable">@drawable/abratingbar</item>
    <item name="android:thumb">@drawable/abseekbar_thumb</item>
    <item name="android:minHeight">@dimen/base_29dp</item>
    <item name="android:maxHeight">@dimen/base_29dp</item>
    <item name="android:layout_marginLeft">@dimen/base_10dp</item>
    <item name="android:layout_marginRight">@dimen/base_10dp</item>
    <item name="android:layout_marginTop">@dimen/base_10dp</item>
    <item name="android:layout_marginBottom">@dimen/base_10dp</item>
    <item name="android:scaleType">fitXY</item>

(Previously, the background setting here was undefined.).

This is the entry in my layout, which uses both the style and the drawables:

    android:layout_gravity="bottom|right" />

So, to summarize, do not set the background (track) feature in your custom RatingBar drawable, set it in the layout_background feature of your custom RatingBar style. This ensures the track is always vertically centered in a horizontal RatingBar. (Remember, in this custom RatingBar, instead of using stars or other isolated images as the rating, I'm using a gradient line that "grows" or "shrinks" horizontally to display the rating - this rating line uses a SeekBar-like thumb running on a SeekBar-like "track".)

Simple bubble sort c#

I wanted to add to the accepted answer something different: Number of iterations can be reduced as well, as below.

int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };

int temp = 0;
int arrLength = arr.Length;

for (int write = 0; write < arr.Length - 1; write++, arrLength--)
    for (int sort = 0; sort < arrLength - 1; sort++)
        if (arr[sort] > arr[sort + 1])
            temp = arr[sort + 1];
            arr[sort + 1] = arr[sort];
            arr[sort] = temp;

foreach (var item in arr)

Toolbar navigation icon never set

Currently you can use it, changing the order: (it seems to be a bug)

Toolbar toolbar = (Toolbar) findViewById(;


open new tab(window) by clicking a link in jquery

Try this:, '_blank');

This will open in new tab (if your code is synchronous and in this case it is. in other case it would open a window)

How can I submit form on button click when using preventDefault()?

Trigger the submit event on the DOM Node, not a jQuery Object.






This bypasses the jQuery bound event allowing the form to submit normally.

Select multiple value in DropDownList using ASP.NET and C#

Dropdown list wont allows multiple item select in dropdown.

If you need , you can use listbox control..

ASP.NET List Box

How to edit incorrect commit message in Mercurial?

EDIT: As pointed out by users, don't use MQ, use commit --amend. This answer is mostly of historic interest now.

As others have mentioned the MQ extension is much more suited for this task, and you don't run the risk of destroying your work. To do this:

  1. Enable the MQ extension, by adding something like this to your hgrc:

    mq =
  2. Update to the changeset you want to edit, typically tip:

    hg up $rev
  3. Import the current changeset into the queue:

    hg qimport -r .
  4. Refresh the patch, and edit the commit message:

    hg qrefresh -e
  5. Finish all applied patches (one, in this case) and store them as regular changesets:

    hg qfinish -a

I'm not familiar with TortoiseHg, but the commands should be similar to those above. I also believe it's worth mentioning that editing history is risky; you should only do it if you're absolutely certain that the changeset hasn't been pushed to or pulled from anywhere else.

How to enable file upload on React's Material UI simple input?

Here's an example using an IconButton to capture input (photo/video capture) using v3.9.2:

import React, { Component, Fragment } from 'react';
import PropTypes from 'prop-types';

import { withStyles } from '@material-ui/core/styles';
import IconButton from '@material-ui/core/IconButton';
import PhotoCamera from '@material-ui/icons/PhotoCamera';
import Videocam from '@material-ui/icons/Videocam';

const styles = (theme) => ({
    input: {
        display: 'none'

class MediaCapture extends Component {
    static propTypes = {
        classes: PropTypes.object.isRequired

    state: {
        images: [],
        videos: []

    handleCapture = ({ target }) => {
        const fileReader = new FileReader();
        const name = target.accept.includes('image') ? 'images' : 'videos';

        fileReader.onload = (e) => {
            this.setState((prevState) => ({
                [name]: [...prevState[name],]

    render() {
        const { classes } = this.props;

        return (
                <label htmlFor="icon-button-photo">
                    <IconButton color="primary" component="span">
                        <PhotoCamera />

                <label htmlFor="icon-button-video">
                    <IconButton color="primary" component="span">
                        <Videocam />

export default withStyles(styles, { withTheme: true })(MediaCapture);

How to create a Java / Maven project that works in Visual Studio Code?

Here is a complete list of steps - you may not need steps 1-3 but am including them for completeness:-

  1. Download VS Code and Apache Maven and install both.
  2. Install the Visual Studio extension pack for Java - e.g. by pasting this URL into a web browser: vscode:extension/vscjava.vscode-java-pack and then clicking on the green Install button after it opens in VS Code.
  3. NOTE: See the comment from ADTC for an "Easier GUI version of step 3...(Skip step 4)." If necessary, the Maven quick start archetype could be used to generate a new Maven project in an appropriate local folder: mvn archetype:generate -DgroupId=com.companyname.appname-DartifactId=appname-DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false. This will create an appname folder with Maven's Standard Directory Layout (i.e. src/main/java/com/companyname/appname and src/main/test/com/companyname/appname to begin with and a sample "Hello World!" Java file named and associated unit test named*
  4. Open the Maven project folder in VS Code via File menu -> Open Folder... and select the appname folder.
  5. Open the Command Palette (via the View menu or by right-clicking) and type in and select Tasks: Configure task then select Create tasks.json from template.
  6. Choose maven ("Executes common Maven commands"). This creates a tasks.json file with "verify" and "test" tasks. More can be added corresponding to other Maven Build Lifecycle phases. To specifically address your requirement for classes to be built without a JAR file, a "compile" task would need to be added as follows:

        "label": "compile",
        "type": "shell",
        "command": "mvn -B compile",
        "group": "build"
  7. Save the above changes and then open the Command Palette and select "Tasks: Run Build Task" then pick "compile" and then "Continue without scanning the task output". This invokes Maven, which creates a target folder at the same level as the src folder with the compiled class files in the target\classes folder.

Addendum: How to run/debug a class

Following a question in the comments, here are some steps for running/debugging:-

  1. Show the Debug view if it is not already shown (via View menu - Debug or CtrlShiftD).
  2. Click on the green arrow in the Debug view and select "Java".
  3. Assuming it hasn't already been created, a message "launch.json is needed to start the debugger. Do you want to create it now?" will appear - select "Yes" and then select "Java" again.
  4. Enter the fully qualified name of the main class (e.g. com.companyname.appname.App) in the value for "mainClass" and save the file.
  5. Click on the green arrow in the Debug view again.

Trying to start a service on boot on Android

Before mounting external storage BOOT_COMPLETE is sent execute.if your app is installed to external storage it won't receive BOOT_COMPLETE broadcast message. To prevent this you can install your application in internal storage. you can do this just adding this line in menifest.xml

<manifest xmlns:android=""
... >

Some HTC devices can enable a "fast boot" feature that is more like a deep hibernation and not a real reboot and therefore should not give the BOOT_COMPLETE intent. To recover this you can add this intent filter inside your receiver:

                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <action android:name="android.intent.action.QUICKBOOT_POWERON" />

Error handling in Bash

That's a fine solution. I just wanted to add

set -e

as a rudimentary error mechanism. It will immediately stop your script if a simple command fails. I think this should have been the default behavior: since such errors almost always signify something unexpected, it is not really 'sane' to keep executing the following commands.

Pointer vs. Reference

This ultimately ends up being subjective. The discussion thus far is useful, but I don't think there is a correct or decisive answer to this. A lot will depend on style guidelines and your needs at the time.

While there are some different capabilities (whether or not something can be NULL) with a pointer, the largest practical difference for an output parameter is purely syntax. Google's C++ Style Guide (, for example, mandates only pointers for output parameters, and allows only references that are const. The reasoning is one of readability: something with value syntax should not have pointer semantic meaning. I'm not suggesting that this is necessarily right or wrong, but I think the point here is that it's a matter of style, not of correctness.

Javascript loading CSV file into an array

I highly recommend looking into this plugin:

I used this for a project handling large CSV files and it handles parsing a CSV into an array quite well. You can use this to call a local file that you specify in your code, also, so you are not dependent on a file upload.

Once you include the plugin above, you can essentially parse the CSV using the following:

    url: "pathto/filename.csv",
    async: false,
    success: function (csvd) {
        data = $.csv.toArrays(csvd);
    dataType: "text",
    complete: function () {
        // call a function on complete 

Everything will then live in the array data for you to manipulate as you need. I can provide further examples for handling the array data if you need.

There are a lot of great examples available on the plugin page to do a variety of things, too.

Does Python have a string 'contains' substring method?

if needle in haystack: is the normal use, as @Michael says -- it relies on the in operator, more readable and faster than a method call.

If you truly need a method instead of an operator (e.g. to do some weird key= for a very peculiar sort...?), that would be 'haystack'.__contains__. But since your example is for use in an if, I guess you don't really mean what you say;-). It's not good form (nor readable, nor efficient) to use special methods directly -- they're meant to be used, instead, through the operators and builtins that delegate to them.

Parsing command-line arguments in C

You probably want to use an external library for that. There are many to chose from.

Boost has a very feature-rich (as usual) library Boost Program Options.

My personal favorite for the last few years has been TCLAP -- purely templated, hence no library or linking, automated '--help' generation and other goodies. See the simplest example from the docs.

Getting list of parameter names inside python function

If you also want the values you can use the inspect module

import inspect

def func(a, b, c):
    frame = inspect.currentframe()
    args, _, _, values = inspect.getargvalues(frame)
    print 'function name "%s"' % inspect.getframeinfo(frame)[2]
    for i in args:
        print "    %s = %s" % (i, values[i])
    return [(i, values[i]) for i in args]

>>> func(1, 2, 3)
function name "func"
    a = 1
    b = 2
    c = 3
[('a', 1), ('b', 2), ('c', 3)]

Open Source HTML to PDF Renderer with Full CSS Support

This command line tool is the business!

It uses webkit rendering engine(used in safari and KDE), I tested it on some complex sites and it was by far better than any other tool.

Searching a list of objects in Python

Another way you could do it is using the next() function.

matched_obj = next(x for x in list if x.n == 10)

Keras, How to get the output of each layer?

Previous solutions were not working for me. I handled this issue as shown below.

layer_outputs = []
for i in range(1, len(model.layers)):
    tmp_model = Model(model.layers[0].input, model.layers[i].output)
    tmp_output = tmp_model.predict(img)[0]

JsonMappingException: No suitable constructor found for type [simple type, class ]: can not instantiate from JSON object

Thumb Rule: Add a default constructor for each class you used as a mapping class. You missed this and issue arise!
Simply add default constructor and it should work.

How do you run a SQL Server query from PowerShell?

You can use the Invoke-Sqlcmd cmdlet

Invoke-Sqlcmd -Query "SELECT GETDATE() AS TimeOfQuery;" -ServerInstance "MyComputer\MyInstance"

Android SDK folder taking a lot of disk space. Do we need to keep all of the System Images?

You do not need to keep the system images unless you want to use the emulator on your desktop. Along with it you can remove other unwanted stuff to clear disk space.

Adding as an answer to my own question as I've had to narrate this to people in my team more than a few times. Hence this answer as a reference to share with other curious ones.

In the last few weeks there were several colleagues who asked me how to safely get rid of the unwanted stuff to release disk space (most of them were beginners). I redirected them to this question but they came back to me for steps. So for android beginners here is a step by step guide to safely remove unwanted stuff.


  • Do not blindly delete everything directly from disk that you "think" is not required occupying. I did that once and had to re-download.
  • Make sure you have a list of all active projects with the kind of emulators (if any) and API Levels and Build tools required for those to continue working/compiling properly.

First, be sure you are not going to use emulators and will always do you development on a physical device. In case you are going to need emulators, note down the API Levels and type of emulators you'll need. Do not remove those. For the rest follow the below steps:

Steps to safely clear up unwanted stuff from Android SDK folder on the disk

  1. Open the Stand Alone Android SDK Manager. To open do one of the following:
  • Click the SDK Manager button on toolbar in android studio or eclipse
  • In Android Studio, go to settings and search "Android SDK". Click Android SDK -> "Open Standalone SDK Manager"
  • In Eclipse, open the "Window" menu and select "Android SDK Manager"
  • Navigate to the location of the android-sdk directory on your computer and run "SDK Manager.exe"


  1. Uncheck all items ending with "System Image". Each API Level will have more than a few. In case you need some and have figured the list already leave them checked to avoid losing them and having to re-download.


  1. Optional (may help save a marginally more amount of disk space): To free up some more space, you can also entirely uncheck unrequired API levels. Be careful again to avoid re-downloading something you are actually using in other projects.


  1. In the end make sure you have at least the following (check image below) for the remaining API levels to be able to seamlessly work with your physical device.

In the end the clean android sdk installed components should look something like this in the SDK manager.

enter image description here

How does one reorder columns in a data frame?

You can use the data.table package:

How to reorder data.table columns (without copying)


npm WARN enoent ENOENT: no such file or directory, open 'C:\Users\Nuwanst\package.json'

NOTE: if you are experiencing this issue in your CI pipeline, it is usually because npm runs npm ci instead of npm install. npm ci requires an accurate package-lock.json.

To fix this, whenever you are modifying packages in package.json (e.g. moving packages from devDependencies to Dependencies like I was doing) you should regenerate package-lock.json in your repository by running these commands locally, and then push the changes upstream:

rm -rf node_modules
npm install
git commit package-lock.json
git push

How can I return two values from a function in Python?

you can try this

class select_choice():
    return x, y

a, b = test()

How to convert DateTime to a number with a precision greater than days in T-SQL?

SELECT CAST(CONVERT(datetime,'2009-06-15 23:01:00') as float)

yields 39977.9590277778

Change a Git remote HEAD to point to something besides master

Related to the question, I ended up here when searching for:

How do I make a local repo aware of a changed default branch on GitHub

For completeness, adding the answer:

git remote set-head origin -a

how to save and read array of array in NSUserdefaults in swift?

Just to add on to what @Zaph says in the comments.

I have the same problem as you, as to know, the array of String is not saved. Even though Apple bridges types such as String and NSString, I wasn't able to save an array of [String] neither of [AnyObject].

However an array of [NSString] works for me.

So your code could look like that :

var key = "keySave"

var array1: [NSString] = [NSString]()
array1.append("value 1")
array1.append("value 2")

var defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(array1, forKey: key)

if let testArray : AnyObject? = defaults.objectForKey(key) {
    var readArray : [NSString] = testArray! as [NSString]

Note that I created an array of NSString and not a dictionary. I didn't check if it works with a dictionary, but probably you will have to define the things as [NSString : NSString] to have it working.


Re-reading your question and your title, you are talking of array of array. I think that as long as you stay with NSString, an array of array will work. However, if you think my answer is irrelevant, just let me know in the comments and I will remove it.

Amazon AWS Filezilla transfer permission denied

In my case the /var/www/html in not a directory but a symbolic link to the /var/app/current, so you should change the real directoy ie /var/app/current:

sudo chown -R ec2-user /var/app/current
sudo chmod -R 755 /var/app/current

I hope this save some of your times :)

Convert cells(1,1) into "A1" and vice versa

The Address property of a cell can get this for you:

MsgBox Cells(1, 1).Address(RowAbsolute:=False, ColumnAbsolute:=False)

returns A1.

The other way around can be done with the Row and Column property of Range:

MsgBox Range("A1").Row & ", " & Range("A1").Column

returns 1,1.

REST, HTTP DELETE and parameters

No, it is not RESTful. The only reason why you should be putting a verb (force_delete) into the URI is if you would need to overload GET/POST methods in an environment where PUT/DELETE methods are not available. Judging from your use of the DELETE method, this is not the case.

HTTP error code 409/Conflict should be used for situations where there is a conflict which prevents the RESTful service to perform the operation, but there is still a chance that the user might be able to resolve the conflict himself. A pre-deletion confirmation (where there are no real conflicts which would prevent deletion) is not a conflict per se, as nothing prevents the API from performing the requested operation.

As Alex said (I don't know who downvoted him, he is correct), this should be handled in the UI, because a RESTful service as such just processes requests and should be therefore stateless (i.e. it must not rely on confirmations by holding any server-side information about of a request).

Two examples how to do this in UI would be to:

  • pre-HTML5:* show a JS confirmation dialog to the user, and send the request only if the user confirms it
  • HTML5:* use a form with action DELETE where the form would contain only "Confirm" and "Cancel" buttons ("Confirm" would be the submit button)

(*) Please note that HTML versions prior to 5 do not support PUT and DELETE HTTP methods natively, however most modern browsers can do these two methods via AJAX calls. See this thread for details about cross-browser support.

Update (based on additional investigation and discussions):

The scenario where the service would require the force_delete=true flag to be present violates the uniform interface as defined in Roy Fielding's dissertation. Also, as per HTTP RFC, the DELETE method may be overridden on the origin server (client), implying that this is not done on the target server (service).

So once the service receives a DELETE request, it should process it without needing any additional confirmation (regardless if the service actually performs the operation).

Simple tool to 'accept theirs' or 'accept mine' on a whole file using git

Based on Jakub's answer you can configure the following git aliases for convenience:

accept-ours = "!f() { git checkout --ours -- \"${@:-.}\"; git add -u \"${@:-.}\"; }; f"
accept-theirs = "!f() { git checkout --theirs -- \"${@:-.}\"; git add -u \"${@:-.}\"; }; f"

They optionally take one or several paths of files to resolve and default to resolving everything under the current directory if none are given.

Add them to the [alias] section of your ~/.gitconfig or run

git config --global alias.accept-ours '!f() { git checkout --ours -- "${@:-.}"; git add -u "${@:-.}"; }; f'
git config --global alias.accept-theirs '!f() { git checkout --theirs -- "${@:-.}"; git add -u "${@:-.}"; }; f'

Where is the Postgresql config file: 'postgresql.conf' on Windows?

On my machine:

C:\Program Files\PostgreSQL\8.4\data\postgresql.conf

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

Use Dictionary<string, DateTime> to store token with timestamp:

static Dictionary<string, DateTime> dic = new Dictionary<string, DateTime>();

Add token with timestamp whenever you create new token:

dic.Add("yourToken", DateTime.Now);

There is a timer running to remove any expired tokens out of dic:

 timer = new Timer(1000*60); //assume run in 1 minute
 timer.Elapsed += timer_Elapsed;

 static void timer_Elapsed(object sender, ElapsedEventArgs e)
        var expiredTokens = dic.Where(p => p.Value.AddDays(1) <= DateTime.Now)
                              .Select(p => p.Key);

        foreach (var key in expiredTokens)

So, when you authenticate token, just check whether token exists in dic or not.

ORA-01017 Invalid Username/Password when connecting to 11g database from 9i client

I also had the similar problem recently with Oracle 12c. It got resolved after I changed the version of the ojdbc jar used. Replaced ojdbc14 with ojdbc6 jar.

Linux : Search for a Particular word in a List of files under a directory

You could club find with exec as follows to get the list of the files as well as the occurrence of the word/string that you are looking for

find . -exec grep "my word" '{}' \; -print

PHP, MySQL error: Column count doesn't match value count at row 1

Your query has 8 or possibly even 9 variables, ie. Name, Description etc. But the values, these things ---> '', '%s', '%s', '%s', '%s', '%s', '%s', '%s')", only total 7, the number of variables have to be the same as the values.

I had the same problem but I figured it out. Hopefully it will also work for you.

Error: stray '\240' in program

Your Program has invalid/invisible characters in it. You most likely would have picked up these invisible characters when you copy and past code from another website or sometimes a document. Copying the code from the site into another text document and then copying and pasting into your code editor may work, but depending on how long your code is you should just go with typing it out word for word.

MySQL timestamp select date range

I can see people giving lots of comments on this question. But I think, simple use of LIKE could be easier to get the data from the table.

SELECT * FROM table WHERE COLUMN LIKE '2013-05-11%'

Use LIKE and post data wild character search. Hopefully this will solve your problem.

String comparison using '==' vs. 'strcmp()'

You should never use == for string comparison. === is OK.

$something = 0;
echo ('password123' == $something) ? 'true' : 'false';

Just run the above code and you'll see why.

$something = 0;
echo ('password123' === $something) ? 'true' : 'false';

Now, that's a little better.

create table in postgreSQL

-- Table: "user"

-- DROP TABLE "user";

  id bigserial NOT NULL,
  name text NOT NULL,
  email character varying(20) NOT NULL,
  password text NOT NULL,
  OWNER TO postgres;