Programs & Examples On #Capacity

How to clear form after submit in Angular 2?

    ObjectName = {};

Hadoop cluster setup - Connection refused

Check your firewall setting and set


replace localhost to machine name

How to stop INFO messages displaying on spark console?

You set disable the Logs by setting its level to OFF as follows:


or edit log file and set log level to off by just changing the following property:

log4j.rootCategory=OFF, console

Convert Swift string to array

for the function on String: components(separatedBy: String)

in Swift 5.1

have change to:

string.split(separator: "/")

Python Key Error=0 - Can't find Dict error in code

The defaultdict solution is better. But for completeness you could also check and create empty list before the append. Add the + lines:

+ if not u in self.adj.keys():
+     self.adj[u] = []

"int cannot be dereferenced" in Java

Assuming getItemNumber() returns an int, replace

if (id.equals(list[pos].getItemNumber()))


if (id == list[pos].getItemNumber())

C# Remove object from list of objects

There are two problems with this code:

  • Capacity represents the number of items the list can contain before resizing is required, not the actual count; you need to use Count instead, and
  • When you remove from the list, you should go backwards, otherwise you could skip the second item when two identical items are next to each other.

How do I get total physical memory size using PowerShell without WMI?

Let's not over complicate things...:

(Get-CimInstance Win32_PhysicalMemory | Measure-Object -Property capacity -Sum).sum /1gb

Creating a List of Lists in C#

or this example, just to make it more visible:

public class CustomerListList : List<CustomerList> { }  

public class CustomerList : List<Customer> { }

public class Customer
   public int ID { get; set; }
   public string SomethingWithText { get; set; }

and you can keep it going. to the infinity and beyond !

How to get disk capacity and free space of remote computer

$disk = Get-WmiObject Win32_LogicalDisk -ComputerName remotecomputer -Filter "DeviceID='C:'" |
Select-Object Size,FreeSpace


To extract the values only and assign them to a variable:

$disk = Get-WmiObject Win32_LogicalDisk -ComputerName remotecomputer -Filter "DeviceID='C:'" |
Foreach-Object {$_.Size,$_.FreeSpace}

Dealing with "Xerces hell" in Java/Maven?

You could use the maven enforcer plugin with the banned dependency rule. This would allow you to ban all the aliases that you don't want and allow only the one you do want. These rules will fail the maven build of your project when violated. Furthermore, if this rule applies to all projects in an enterprise you could put the plugin configuration in a corporate parent pom.


SQL Server dynamic PIVOT query?

Dynamic SQL PIVOT:

create table temp
    date datetime,
    category varchar(3),
    amount money

insert into temp values ('1/1/2012', 'ABC', 1000.00)
insert into temp values ('2/1/2012', 'DEF', 500.00)
insert into temp values ('2/1/2012', 'GHI', 800.00)
insert into temp values ('2/10/2012', 'DEF', 700.00)
insert into temp values ('3/1/2012', 'ABC', 1100.00)

    @query  AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT distinct ',' + QUOTENAME(c.category) 
            FROM temp c
            FOR XML PATH(''), TYPE
            ).value('.', 'NVARCHAR(MAX)') 

set @query = 'SELECT date, ' + @cols + ' from 
                select date
                    , amount
                    , category
                from temp
           ) x
                for category in (' + @cols + ')
            ) p '


drop table temp


Date                        ABC         DEF    GHI
2012-01-01 00:00:00.000     1000.00     NULL    NULL
2012-02-01 00:00:00.000     NULL        500.00  800.00
2012-02-10 00:00:00.000     NULL        700.00  NULL
2012-03-01 00:00:00.000     1100.00     NULL    NULL

Merging two arrayLists into a new arrayList, with no duplicates and in order, in Java

your nested for loop

 for(int j = 0; j < array2.size(); i++){

is infinite as j will always equal to zero, on the other hand, i will be increased at will in this loop. You get OutOfBoundaryException when i is larger than plusArray.size()

Xcode error - Thread 1: signal SIGABRT

SIGABRT means in general that there is an uncaught exception. There should be more information on the console.

How to add buttons dynamically to my form?

It doesn't work because the list is empty. Try this:

private void button1_Click(object sender, EventArgs e)
    List<Button> buttons = new List<Button>();
    for (int i = 0; i < 10; i++)
        Button newButton = new Button();

Service Temporarily Unavailable Magento?

You can do this thing:

Go to http://localhost/magento/downloader url. Here I am running the magento store on my localhost. Now you can login to magento connect manager and uninstall the extension which you installed previously.

Hope this works !!!!!


How can I shutdown Spring task executor/scheduler pools before all other beans in the web app are destroyed?

We can add "AwaitTerminationSeconds" property for both taskExecutor and taskScheduler as below,

<property name="awaitTerminationSeconds" value="${taskExecutor .awaitTerminationSeconds}" />

<property name="awaitTerminationSeconds" value="${taskScheduler .awaitTerminationSeconds}" />

Documentation for "waitForTasksToCompleteOnShutdown" property says, when shutdown is called

"Spring's container shutdown continues while ongoing tasks are being completed. If you want this executor to block and wait for the termination of tasks before the rest of the container continues to shut down - e.g. in order to keep up other resources that your tasks may need -, set the "awaitTerminationSeconds" property instead of or in addition to this property."

So it is always advised to use waitForTasksToCompleteOnShutdown and awaitTerminationSeconds properties together. Value of awaitTerminationSeconds depends on our application.

Range of values in C Int and Long 32 - 64 bits

In fact, unsigned int on most modern processors (ARM, Intel/AMD, Alpha, SPARC, Itanium ,PowerPC) will have a range of 0 to 2^32 - 1 which is 4,294,967,295 = 0xffffffff because int (both signed and unsigned) will be 32 bits long and the largest one is as stated.

(unsigned short will have maximal value 2^16 - 1 = 65,535 )

(unsigned) long long int will have a length of 64 bits (long int will be enough under most 64 bit Linuxes, etc, but the standard promises 64 bits for long long int). Hence these have the range 0 to 2^64 - 1 = 18446744073709551615

Create the perfect JPA entity

The JPA 2.0 Specification states that:

  • The entity class must have a no-arg constructor. It may have other constructors as well. The no-arg constructor must be public or protected.
  • The entity class must a be top-level class. An enum or interface must not be designated as an entity.
  • The entity class must not be final. No methods or persistent instance variables of the entity class may be final.
  • If an entity instance is to be passed by value as a detached object (e.g., through a remote interface), the entity class must implement the Serializable interface.
  • Both abstract and concrete classes can be entities. Entities may extend non-entity classes as well as entity classes, and non-entity classes may extend entity classes.

The specification contains no requirements about the implementation of equals and hashCode methods for entities, only for primary key classes and map keys as far as I know.

Delete item from array and shrink array

Using ArrayUtils.removeElement(Object[],Object) from org.apache.commons.lang is by far the easiest way to do this.

int[] numbers = {1,2,3,4,5,6,7};
//removing number 1
numbers =(int[])ArrayUtils.removeElement(numbers, 1);

error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

try using return 0;

if it keeps failing change your solution platform to 64x instead of 86x and go to configuration manager(that's were you change the 86x to 64x) and in platform set it to 64 bits

that works for me, hope it work to you

ArrayList: how does the size increase?

Default capacity of ArrayList is 10. Once the Capacity reaches its maximum capacity, Size of the ArrayList will be 16, once the capacity reaches its maximum capacity of 16, size of the ArrayList will be 25 and keep on increasing based on Data size.....

How? Here is the Answer and Formula

New capacity = (Current Capacity * 3/2) + 1

So, if the default capacity is 10, then

Current Capacity = 10
New capacity = (10 * 3/2) + 1
Output is 16

What's the reason I can't create generic array types in Java?

From Oracle tutorial:

You cannot create arrays of parameterized types. For example, the following code does not compile:

List<Integer>[] arrayOfLists = new List<Integer>[2];  // compile-time error

The following code illustrates what happens when different types are inserted into an array:

Object[] strings = new String[2];
strings[0] = "hi";   // OK
strings[1] = 100;    // An ArrayStoreException is thrown.

If you try the same thing with a generic list, there would be a problem:

Object[] stringLists = new List<String>[];  // compiler error, but pretend it's allowed
stringLists[0] = new ArrayList<String>();   // OK
stringLists[1] = new ArrayList<Integer>();  // An ArrayStoreException should be thrown,
                                            // but the runtime can't detect it.

If arrays of parameterized lists were allowed, the previous code would fail to throw the desired ArrayStoreException.

To me, it sounds very weak. I think that anybody with a sufficient understanding of generics, would be perfectly fine, and even expect, that the ArrayStoredException is not thrown in such case.

How do I increase the capacity of the Eclipse output console?

Eclipse has limit of 32000 characters per line. If you have, for example JSONObject, which you want to log into console, you won't succeed. You can't handle this with the checkbox. Tested

How to start a Process as administrator mode in C#

First of all you need to include in your project

using System.Diagnostics;

After that you could write a general method that you could use for different .exe files that you want to use. It would be like below:

public void ExecuteAsAdmin(string fileName)
    Process proc = new Process();
    proc.StartInfo.FileName = fileName;
    proc.StartInfo.UseShellExecute = true;
    proc.StartInfo.Verb = "runas";

If you want to for example execute notepad.exe then all you do is you call this method:


How do I enable FFMPEG logging and where can I find the FFMPEG log file?

You can find more debugging info just simply adding the option -loglevel debug, full command will be

ffmpeg -i INPUT OUTPUT -loglevel debug -v verbose

Using an HTML button to call a JavaScript function

Your code is failing on this line:

var RUnits = Math.abs(document.all.Capacity.RUnits.value);

i tried stepping though it with firebug and it fails there. that should help you figure out the problem.

you have jquery referenced. you might as well use it in all these functions. it'll clean up your code significantly.

Java HashMap performance optimization / alternative

In my case I want to create a map with 26 million entries. Using the standard Java HashMap the put rate becomes unbearably slow after 2-3 million insertions.

From my experiment (student project in 2009):

  • I built up a Red Black Tree for 100.000 nodes from 1 to 100.000. It took 785.68 seconds (13 minutes). And I failed to build up RBTree for 1 million nodes (like your results with HashMap).
  • Using "Prime Tree", my algorithm data structure. I could build up a tree/map for 10 million nodes within 21.29 seconds (RAM: 1.97Gb). Search key-value cost is O(1).

Note: "Prime Tree" works best on "continuous keys" from 1 - 10 millions. To work with keys like HashMap we need some minors adjustment.

So, what is #PrimeTree? In short, it is a tree data structure like Binary Tree, with branches numbers are prime numbers (instead of "2"-binary).

Multidimensional Lists in C#

Why don't you use a List<People> instead of a List<List<string>> ?

Try/catch does not seem to have an effect

If you want try/catch to work for all errors (not just the terminating errors) you can manually make all errors terminating by setting the ErrorActionPreference.

try {

   $ErrorActionPreference = "Stop"; #Make all errors terminating
   get-item filethatdoesntexist; # normally non-terminating
   write-host "You won't hit me";  
} catch{
   Write-Host "Caught the exception";
   Write-Host $Error[0].Exception;
   $ErrorActionPreference = "Continue"; #Reset the error action pref to default

Alternatively... you can make your own trycatch function that accepts scriptblocks so that your try catch calls are not as kludge. I have mine return true/false just in case i need to check if there was an error... but it doesnt have to. Also, exception logging is optional, and can be taken care of in the catch, but i found myself always calling the logging function in the catch block, so i added it to the try catch function.

function log([System.String] $text){write-host $text;}

function logException{
    log "Logging current exception.";
    log $Error[0].Exception;

function mytrycatch ([System.Management.Automation.ScriptBlock] $try,
                    [System.Management.Automation.ScriptBlock] $catch,
                    [System.Management.Automation.ScriptBlock]  $finally = $({})){

# Make all errors terminating exceptions.
    $ErrorActionPreference = "Stop";

    # Set the trap
    trap [System.Exception]{
        # Log the exception.

        # Execute the catch statement
        & $catch;

        # Execute the finally statement
        & $finally

        # There was an exception, return false
        return $false;

    # Execute the scriptblock
    & $try;

    # Execute the finally statement
    & $finally

    # The following statement was hit.. so there were no errors with the scriptblock
    return $true;

#execute your own try catch
mytrycatch {
        gi filethatdoesnotexist; #normally non-terminating
        write-host "You won't hit me."
    } {
        Write-Host "Caught the exception";

how to loop through rows columns in excel VBA Macro

Try this:

Create A Macro with the following thing inside:

ActiveCell.Offset(1, 0).Select
ActiveCell.Offset(-1, 1).Select
ActiveCell.Offset(1, 0).Select
ActiveCell.Offset(0, -1).Select

That particular macro will copy the current cell (place your cursor in the VOL cell you wish to copy) down one row and then copy the CAP cell also.

This is only a single loop so you can automate copying VOL and CAP of where your current active cell (where your cursor is) to down 1 row.

Just put it inside a For loop statement to do it x number of times. like:

For i = 1 to 100 'Do this 100 times
    ActiveCell.Offset(1, 0).Select
    ActiveCell.Offset(-1, 1).Select
    ActiveCell.Offset(1, 0).Select
    ActiveCell.Offset(0, -1).Select
Next i

What are the performance characteristics of sqlite with very large database files?

I've experienced problems with large sqlite files when using the vacuum command.

I haven't tried the auto_vacuum feature yet. If you expect to be updating and deleting data often then this is worth looking at.

What is a practical, real world example of the Linked List?

Look at a linked list :

[A]=> [B]=> [C]=> [D]=>

It's a ... Train ! Each railroad car contain something and is attached to another railroad car (or nothing for the last one). You can only add a railroad car at the end and if you want to get rid of one you must attach the previous one with the next one.

Plotting with C#

ZedGraph is a good choice.

How to create a generic array in Java?

In Java 8, we can do a kind of generic array creation using a lambda or method reference. This is similar to the reflective approach (which passes a Class), but here we aren't using reflection.

interface ArraySupplier<E> {
    E[] get(int length);

class GenericSet<E> {
    private final ArraySupplier<E> supplier;
    private E[] array;

    GenericSet(ArraySupplier<E> supplier) {
        this.supplier = supplier;
        this.array    = supplier.get(10);

    public static void main(String[] args) {
        GenericSet<String> ofString =
            new GenericSet<>(String[]::new);
        GenericSet<Double> ofDouble =
            new GenericSet<>(Double[]::new);

For example, this is used by <A> A[] Stream.toArray(IntFunction<A[]>).

This could also be done pre-Java 8 using anonymous classes but it's more cumbersome.

How to initialize a List<T> to a given size (as opposed to capacity)?

If you want to initialize the list with N elements of some fixed value:

public List<T> InitList<T>(int count, T initValue)
  return Enumerable.Repeat(initValue, count).ToList();

How to convert a string of bytes into an int?

You can also use the struct module to do this:

>>> struct.unpack("<L", "y\xcc\xa6\xbb")[0]

Create a list with initial capacity in Python

def doAppend( size=10000 ):
    result = []
    for i in range(size):
        message= "some unique object %d" % ( i, )
    return result

def doAllocate( size=10000 ):
    for i in range(size):
        message= "some unique object %d" % ( i, )
        result[i]= message
    return result

Results. (evaluate each function 144 times and average the duration)

simple append 0.0102
pre-allocate  0.0098

Conclusion. It barely matters.

Premature optimization is the root of all evil.

Reading the selected value from asp:RadioButtonList using jQuery

The simple way to retrieve checked value of RadioButtonList1 is:

$('#RadioButtonList1 input:checked').val()

Edit by Tim:

where RadioButtonList1 must be the ClientID of the RadioButtonList

var rblSelectedValue = $("#<%= RadioButtonList1.ClientID %> input:checked"); 

Verilog generate/genvar in an always block

You need to reverse the nesting inside the generate block:

genvar c;
    for (c = 0; c < ROWBITS; c = c + 1) begin: test
        always @(posedge sysclk) begin
            temp[c] <= 1'b0;

Technically, this generates four always blocks:

always @(posedge sysclk) temp[0] <= 1'b0;
always @(posedge sysclk) temp[1] <= 1'b0;
always @(posedge sysclk) temp[2] <= 1'b0;
always @(posedge sysclk) temp[3] <= 1'b0;

In this simple example, there's no difference in behavior between the four always blocks and a single always block containing four assignments, but in other cases there could be.

The genvar-dependent operation needs to be resolved when constructing the in-memory representation of the design (in the case of a simulator) or when mapping to logic gates (in the case of a synthesis tool). The always @posedge doesn't have meaning until the design is operating.

Subject to certain restrictions, you can put a for loop inside the always block, even for synthesizable code. For synthesis, the loop will be unrolled. However, in that case, the for loop needs to work with a reg, integer, or similar. It can't use a genvar, because having the for loop inside the always block describes an operation that occurs at each edge of the clock, not an operation that can be expanded statically during elaboration of the design.

The term 'ng' is not recognized as the name of a cmdlet

Instead of giving "ng serve" command in the Visual Studio code terminal, open angular app path in the command prompt(Run as Administrator).

Then give "ng serve" command.

Then open browser and go to the http://localhost:4200/

It works for me.

Git commit with no commit message

The commit message is a best practice that should be followed at all times. Unless you're the only developer and that isn't going to change any time soon.

git commit -a -m 'asdfasdfadsfsdf'

Check if table exists

If using jruby, here is a code snippet to return an array of all tables in a db.

require "rubygems"
require "jdbc/mysql"
require "java"

def get_database_tables(connection, db_name)
  md = connection.get_meta_data
  rs = md.get_tables(db_name, nil, '%',["TABLE"])

  tables = []
  count = 0
    tables << rs.get_string(3)
  end #while
  return tables

Calculating Waiting Time and Turnaround Time in (non-preemptive) FCFS queue

For non-preemptive system,

waitingTime = startTime - arrivalTime

turnaroundTime = burstTime + waitingTime = finishTime- arrivalTime

startTime = Time at which the process started executing

finishTime = Time at which the process finished executing

You can keep track of the current time elapsed in the system(timeElapsed). Assign all processors to a process in the beginning, and execute until the shortest process is done executing. Then assign this processor which is free to the next process in the queue. Do this until the queue is empty and all processes are done executing. Also, whenever a process starts executing, recored its startTime, when finishes, record its finishTime (both same as timeElapsed). That way you can calculate what you need.

How can I insert data into Database Laravel?

make sure you use the POST to insert the data. Actually you were using GET.

Best Practices: working with long, multiline strings in PHP?

but what's the deal with new lines and carriage returns? What's the difference? Is \n\n the equivalent of \r\r or \n\r? Which should I use when I'm creating a line gap between lines?

No one here seemed to actualy answer this question, so here I am.

\r represents 'carriage-return'

\n represents 'line-feed'

The actual reason for them goes back to typewriters. As you typed the 'carriage' would slowly slide, character by character, to the right of the typewriter. When you got to the end of the line you would return the carriage and then go to a new line. To go to the new line, you would flip a lever which fed the lines to the type writer. Thus these actions, combined, were called carriage return line feed. So quite literally:

A line feed,\n, means moving to the next line.

A carriage return, \r, means moving the cursor to the beginning of the line.

Ultimately Hello\n\nWorld should result in the following output on the screen:



Where as Hello\r\rWorld should result in the following output.

It's only when combining the 2 characters \r\n that you have the common understanding of knew line. I.E. Hello\r\nWorld should result in:


And of course \n\r would result in the same visual output as \r\n.

Originally computers took \r and \n quite literally. However these days the support for carriage return is sparse. Usually on every system you can get away with using \n on its own. It never depends on the OS, but it does depend on what you're viewing the output in.

Still I'd always advise using \r\n wherever you can!

How to prevent multiple definitions in C?

I had similar problem and i solved it following way.

Solve as follows:

Function prototype declarations and global variable should be in test.h file and you can not initialize global variable in header file.

Function definition and use of global variable in test.c file

if you initialize global variables in header it will have following error

multiple definition of `_ test'| obj\Debug\main.o:path\test.c|1|first defined here|

Just declarations of global variables in Header file no initialization should work.

Hope it helps


Test if string is a number in Ruby on Rails

If you prefer not to use exceptions as part of the logic, you might try this:

class String
   def numeric?
    !!(self =~ /^-?\d+(\.\d*)?$/)

Or, if you want it to work across all object classes, replace class String with class Object an convert self to a string: !!(self.to_s =~ /^-?\d+(\.\d*)?$/)

HTML5 <video> element on Android

If you manually call it should work:

<!DOCTYPE html>
    function init() {

    function enableVideoClicks() {
      var videos = document.getElementsByTagName('video') || [];
      for (var i = 0; i < videos.length; i++) {
        // TODO: use attachEvent in IE
        videos[i].addEventListener('click', function(videoNode) {
          return function() {
<body onload="init()">

  <video src="sample.mp4" width="400" height="300" controls></video>



Simpler way to create dictionary of separate variables?

This is a hack. It will not work on all Python implementations distributions (in particular, those that do not have traceback.extract_stack.)

import traceback

def make_dict(*expr):
    text=[name.strip() for name in text[begin:end].split(',')]
    return dict(zip(text,expr))

# {'foo': False, 'bar': True}

Note that this hack is fragile:


(calling make_dict on 2 lines) will not work.

Instead of trying to generate the dict out of the values foo and bar, it would be much more Pythonic to generate the dict out of the string variable names 'foo' and 'bar':

dict([(name,locals()[name]) for name in ('foo','bar')])

error: This is probably not a problem with npm. There is likely additional logging output above

Novice mistake. Make sure your package.json file is coded correctly. I had:

"start": "index node.js"
instead of:
"start": "node index.js"


Delete your package-lock.json file and node_modules folder. Then do npm cache clean

npm cache clean --force do npm install

Is it possible to remove the hand cursor that appears when hovering over a link? (or keep it set as the normal pointer)

Using inline styling use <a href="your link here" style="cursor:default">your content here</a>. See this example

Alternatively use css. See this example.

This solution is cross-browser compatible.

Evaluate list.contains string in JSTL

Another way of doing this is using a Map (HashMap) with Key, Value pairs representing your object.

Map<Long, Object> map = new HashMap<Long, Object>();
map.put(new Long(1), "one");
map.put(new Long(2), "two");


<c:if test="${not empty map[1]}">

This should return true if the pair exist in the map

How to find out what character key is pressed?

There are a million duplicates of this question on here, but here goes again anyway:

document.onkeypress = function(evt) {
    evt = evt || window.event;
    var charCode = evt.keyCode || evt.which;
    var charStr = String.fromCharCode(charCode);

The best reference on key events I've seen is

Verify a certificate chain using openssl verify

I've had to do a verification of a letsencrypt certificate and I did it like this:

  1. Download the root-cert and the intermediate-cert from the letsencrypt chain of trust.
  2. Issue this command:

    $ openssl verify -CAfile letsencrypt-root-cert/isrgrootx1.pem.txt -untrusted letsencrypt-intermediate-cert/letsencryptauthorityx3.pem.txt /etc/letsencrypt/live/sitename.tld/cert.pem 
    /etc/letsencrypt/live/sitename.tld/cert.pem: OK

How to set a header for a HTTP GET request, and trigger file download?



<!-- placeholder , 
    `click` download , `.remove()` options ,
     at js callback , following js 


        $(document).ready(function () {
                // `url` 
                url: '/echo/json/',
                type: "POST",
                dataType: 'json',
                // `file`, data-uri, base64
                data: {
                    json: JSON.stringify({
                        "file": "data:text/plain;base64,YWJj"
                // `custom header`
                headers: {
                    "x-custom-header": 123
                beforeSend: function (jqxhr) {
                    alert("custom headers" + JSON.stringify(this.headers));
                success: function (data) {
                    // `file download`
                        "href": data.file,
                            "download": "file.txt"
                error: function (jqxhr, textStatus, errorThrown) {
                  console.log(textStatus, errorThrown)


Starting the week on Monday with isoWeekday()

For those who want isoWeek to be the default you can modify moment's behaviour as such:

const moment = require('moment');
const proto = Object.getPrototypeOf(moment());

const {startOf, endOf} = proto;
proto.startOf = function(period) {
  if (period === 'week') {
    period = 'isoWeek';
  return, period);
proto.endOf = function(period) {
  if (period === 'week') {
    period = 'isoWeek';
  return, period);

Now you can simply use someDate.startOf('week') without worrying you'll get sunday or having to think about whether to use isoweek or isoWeek etc.

Plus you can store this in a variable like const period = 'week' and use it safely in subtract() or add() operations, e.g. moment().subtract(1, period).startOf(period);. This won't work with period being isoWeek.

Delete column from pandas DataFrame


columns = ['Col1', 'Col2', ...]
df.drop(columns, inplace=True, axis=1)

This will delete one or more columns in-place. Note that inplace=True was added in pandas v0.13 and won't work on older versions. You'd have to assign the result back in that case:

df = df.drop(columns, axis=1)

Configure hibernate (using JPA) to store Y/N for type Boolean instead of 0/1

Hibernate has a built-in "yes_no" type that would do what you want. It maps to a CHAR(1) column in the database.

Basic mapping: <property name="some_flag" type="yes_no"/>

Annotation mapping (Hibernate extensions):

public boolean getFlag();

What do two question marks together mean in C#?

The ?? operator is called the null-coalescing operator. It returns the left-hand operand if the operand is not null; otherwise it returns the right hand operand.

int? variable1 = null;
int variable2  = variable1 ?? 100;

Set variable2 to the value of variable1, if variable1 is NOT null; otherwise, if variable1 == null, set variable2 to 100.

How to concatenate strings of a string field in a PostgreSQL 'group by' query?

PostgreSQL 9.0 or later:

Recent versions of Postgres (since late 2010) have the string_agg(expression, delimiter) function which will do exactly what the question asked for, even letting you specify the delimiter string:

SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;

Postgres 9.0 also added the ability to specify an ORDER BY clause in any aggregate expression; otherwise, the order is undefined. So you can now write:

SELECT company_id, string_agg(employee, ', ' ORDER BY employee)
FROM mytable
GROUP BY company_id;

Or indeed:

SELECT string_agg(actor_name, ', ' ORDER BY first_appearance)

PostgreSQL 8.4 or later:

PostgreSQL 8.4 (in 2009) introduced the aggregate function array_agg(expression) which concatenates the values into an array. Then array_to_string() can be used to give the desired result:

SELECT company_id, array_to_string(array_agg(employee), ', ')
FROM mytable
GROUP BY company_id;

string_agg for pre-8.4 versions:

In case anyone comes across this looking for a compatibilty shim for pre-9.0 databases, it is possible to implement everything in string_agg except the ORDER BY clause.

So with the below definition this should work the same as in a 9.x Postgres DB:

SELECT string_agg(name, '; ') AS semi_colon_separated_names FROM things;

But this will be a syntax error:

SELECT string_agg(name, '; ' ORDER BY name) AS semi_colon_separated_names FROM things;
--> ERROR: syntax error at or near "ORDER"

Tested on PostgreSQL 8.3.

CREATE FUNCTION string_agg_transfn(text, text, text)
    RETURNS text AS 
            IF $1 IS NULL THEN
                RETURN $2;
                RETURN $1 || $3 || $2;
            END IF;

CREATE AGGREGATE string_agg(text, text) (

Custom variations (all Postgres versions)

Prior to 9.0, there was no built-in aggregate function to concatenate strings. The simplest custom implementation (suggested by Vajda Gabo in this mailing list post, among many others) is to use the built-in textcat function (which lies behind the || operator):

  basetype    = text,
  sfunc       = textcat,
  stype       = text,
  initcond    = ''

Here is the CREATE AGGREGATE documentation.

This simply glues all the strings together, with no separator. In order to get a ", " inserted in between them without having it at the end, you might want to make your own concatenation function and substitute it for the "textcat" above. Here is one I put together and tested on 8.3.12:

CREATE FUNCTION commacat(acc text, instr text) RETURNS text AS $$
    IF acc IS NULL OR acc = '' THEN
      RETURN instr;
      RETURN acc || ', ' || instr;
    END IF;
$$ LANGUAGE plpgsql;

This version will output a comma even if the value in the row is null or empty, so you get output like this:

a, b, c, , e, , g

If you would prefer to remove extra commas to output this:

a, b, c, e, g

Then add an ELSIF check to the function like this:

CREATE FUNCTION commacat_ignore_nulls(acc text, instr text) RETURNS text AS $$
    IF acc IS NULL OR acc = '' THEN
      RETURN instr;
    ELSIF instr IS NULL OR instr = '' THEN
      RETURN acc;
      RETURN acc || ', ' || instr;
    END IF;
$$ LANGUAGE plpgsql;

Call method in directive controller from other controller

I got much better solution .

here is my directive , I have injected on object reference in directive and has extend that by adding invoke function in directive code .

app.directive('myDirective', function () {
    return {
        restrict: 'E',
        scope: {
        /*The object that passed from the cntroller*/
        objectToInject: '=',
        templateUrl: 'templates/myTemplate.html',

        link: function ($scope, element, attrs) {
            /*This method will be called whet the 'objectToInject' value is changes*/
            $scope.$watch('objectToInject', function (value) {
                /*Checking if the given value is not undefined*/
                $scope.Obj = value;
                    /*Injecting the Method*/
                    $scope.Obj.invoke = function(){
                        //Do something

Declaring the directive in the HTML with a parameter:

<my-directive object-to-inject="injectedObject"></ my-directive>

my Controller:

app.controller("myController", ['$scope', function ($scope) {
   // object must be empty initialize,so it can be appended
    $scope.injectedObject = {};

    // now i can directly calling invoke function from here 

How to increase executionTimeout for a long-running query?

Execution Timeout is 90 seconds for .NET Framework 1.0 and 1.1, 110 seconds otherwise.

If you need to change defult settings you need to do it in your web.config under <httpRuntime>

<httpRuntime executionTimeout = "number(in seconds)"/>

But Remember:

This time-out applies only if the debug attribute in the compilation element is False.

Have look at in detail about compilation Element

Have look at this document about httpRuntime Element

Concatenating null strings in Java

The second line is transformed to the following code:

s = (new StringBuilder()).append((String)null).append("hello").toString();

The append methods can handle null arguments.

how to get the host url using javascript from the current page

// will return the host name and port
var host =; 

or possibly

var host = window.location.protocol + "//" +;

or if you like concatenation

var protocol = location.protocol;
var slashes = protocol.concat("//");
var host = slashes.concat(;

// or as you probably should do
var host = location.protocol.concat("//").concat(;

// the above is the same as origin, e.g. ""
var host = window.location.origin;

If you have or expect custom ports use instead of window.location.hostname

How can I get new selection in "select" in Angular 2?

<mat-select placeholder="Vacancies" [(ngModel)]="vacanciesSpinnerSelectedItem.code" (ngModelChange)="spinnerClick1($event)"
    [ngModelOptions]="{standalone: true}" required>
    <mat-option *ngFor="let spinnerValue of vacanciesSpinnerValues" [value]="spinnerValue?.code">{{spinnerValue.description}}</mat-option>

I used this for angular Material dropdown. works fine

How to bind 'touchstart' and 'click' events but not respond to both?

Just for documentation purposes, here's what I've done for the fastest/most responsive click on desktop/tap on mobile solution that I could think of:

I replaced jQuery's on function with a modified one that, whenever the browser supports touch events, replaced all my click events with touchstart.

$.fn.extend({ _on: (function(){ return $.fn.on; })() });
    on: (function(){
        var isTouchSupported = 'ontouchstart' in window || window.DocumentTouch && document instanceof DocumentTouch;
        return function( types, selector, data, fn, one ) {
            if (typeof types == 'string' && isTouchSupported && !(types.match(/touch/gi))) types = types.replace(/click/gi, 'touchstart');
            return this._on( types, selector, data, fn);

Usage than would be the exact same as before, like:

$('#my-button').on('click', function(){ /* ... */ });

But it would use touchstart when available, click when not. No delays of any kind needed :D

Slick Carousel Uncaught TypeError: $(...).slick is not a function

I found that I initialised my slider using inline script in the body, which meant it was being called before slick.js had been loaded. I fixed using inline JS in the footer to initialise the slider after including the slick.js file.

<script type="text/javascript" src="/slick/slick.min.js"></script>
        slidesToShow: 1,
        slidesToScroll: 1,
        autoplay: true,
        autoplaySpeed: 4000,


eloquent laravel: How to get a row count from a ->get()

Direct get a count of row

Using Eloquent

 //Useing Eloquent
 $count = Model::count();    

 $count1 = Wordlist::count();

Using query builder

 //Using query builder
 $count = \DB::table('table_name')->count();

 $count2 = \DB::table('wordlist')->where('id', '<=', $correctedComparisons)->count();

How to switch to another domain and get-aduser

I just want to add that if you don't inheritently know the name of a domain controller, you can get the closest one, pass it's hostname to the -Server argument.

$dc = Get-ADDomainController -DomainName -Discover -NextClosestSite

Get-ADUser -Server $dc.HostName[0] `
    -Filter { EmailAddress -Like "*Smith_Karla*" } `
    -Properties EmailAddress

How do I revert all local changes in Git managed project to previous state?

After reading a bunch of answers and trying them, I've found various edge cases that mean sometimes they don't fully clean the working copy.

Here's my current bash script for doing it, which works all the time.

git reset --hard
git clean -f -d
git checkout HEAD

Run from working copy root directory.

Convert UIImage to NSData and convert back to UIImage in Swift?


  • Xcode 10.2.1 (10E1001), Swift 5

Solution 1

guard let image = UIImage(named: "img") else { return }
let jpegData = image.jpegData(compressionQuality: 1.0)
let pngData = image.pngData()

Solution 2.1

extension UIImage {
    func toData (options: NSDictionary, type: CFString) -> Data? {
        guard let cgImage = cgImage else { return nil }
        return autoreleasepool { () -> Data? in
            let data = NSMutableData()
            guard let imageDestination = CGImageDestinationCreateWithData(data as CFMutableData, type, 1, nil) else { return nil }
            CGImageDestinationAddImage(imageDestination, cgImage, options)
            return data as Data

Usage of solution 2.1

// about properties:
let options: NSDictionary =     [
    kCGImagePropertyOrientation: 6,
    kCGImagePropertyHasAlpha: true,
    kCGImageDestinationLossyCompressionQuality: 0.5

guard let data = image.toData(options: options, type: kUTTypeJPEG) else { return }
let size = CGFloat(data.count)/1000.0/1024.0
print("\(size) mb")

Solution 2.2

extension UIImage {

    func toJpegData (compressionQuality: CGFloat, hasAlpha: Bool = true, orientation: Int = 6) -> Data? {
        guard cgImage != nil else { return nil }
        let options: NSDictionary =     [
                                            kCGImagePropertyOrientation: orientation,
                                            kCGImagePropertyHasAlpha: hasAlpha,
                                            kCGImageDestinationLossyCompressionQuality: compressionQuality
        return toData(options: options, type: .jpeg)

    func toData (options: NSDictionary, type: ImageType) -> Data? {
        guard cgImage != nil else { return nil }
        return toData(options: options, type: type.value)
    // about properties:
    func toData (options: NSDictionary, type: CFString) -> Data? {
        guard let cgImage = cgImage else { return nil }
        return autoreleasepool { () -> Data? in
            let data = NSMutableData()
            guard let imageDestination = CGImageDestinationCreateWithData(data as CFMutableData, type, 1, nil) else { return nil }
            CGImageDestinationAddImage(imageDestination, cgImage, options)
            return data as Data

    enum ImageType {
        case image // abstract image data
        case jpeg                       // JPEG image
        case jpeg2000                   // JPEG-2000 image
        case tiff                       // TIFF image
        case pict                       // Quickdraw PICT format
        case gif                        // GIF image
        case png                        // PNG image
        case quickTimeImage             // QuickTime image format (OSType 'qtif')
        case appleICNS                  // Apple icon data
        case bmp                        // Windows bitmap
        case ico                        // Windows icon data
        case rawImage                   // base type for raw image data (.raw)
        case scalableVectorGraphics     // SVG image
        case livePhoto                  // Live Photo

        var value: CFString {
            switch self {
            case .image: return kUTTypeImage
            case .jpeg: return kUTTypeJPEG
            case .jpeg2000: return kUTTypeJPEG2000
            case .tiff: return kUTTypeTIFF
            case .pict: return kUTTypePICT
            case .gif: return kUTTypeGIF
            case .png: return kUTTypePNG
            case .quickTimeImage: return kUTTypeQuickTimeImage
            case .appleICNS: return kUTTypeAppleICNS
            case .bmp: return kUTTypeBMP
            case .ico: return kUTTypeICO
            case .rawImage: return kUTTypeRawImage
            case .scalableVectorGraphics: return kUTTypeScalableVectorGraphics
            case .livePhoto: return kUTTypeLivePhoto

Usage of solution 2.2

let compressionQuality: CGFloat = 0.4
guard let data = image.toJpegData(compressionQuality: compressionQuality) else { return }
printSize(of: data)

let options: NSDictionary =     [
                                    kCGImagePropertyHasAlpha: true,
                                    kCGImageDestinationLossyCompressionQuality: compressionQuality
guard let data2 = image.toData(options: options, type: .png) else { return }
printSize(of: data2)


Image representing will take a lot of cpu and memory resources. So, in this case it is better to follow several rules:

- do not run jpegData(compressionQuality:) on main queue

- run only one jpegData(compressionQuality:) simultaneously


for i in 0...50 { .utility).async {
        let quality = 0.02 * CGFloat(i)
        //let data = image.toJpegData(compressionQuality: quality)
        let data = image.jpegData(compressionQuality: quality)
        let size = CGFloat(data!.count)/1000.0/1024.0
        print("\(i), quality: \(quality), \(size.rounded()) mb")


let serialQueue = DispatchQueue(label: "queue", qos: .utility, attributes: [], autoreleaseFrequency: .workItem, target: nil)

for i in 0...50 {
    serialQueue.async {
        let quality = 0.02 * CGFloat(i)
        //let data = image.toJpegData(compressionQuality: quality)
        let data = image.jpegData(compressionQuality: quality)
        let size = CGFloat(data!.count)/1000.0/1024.0
        print("\(i), quality: \(quality), \(size.rounded()) mb")


Could not open ServletContext resource

I had the same error.

My filename was jpaContext.xml and it was placed in src/main/resources. I specified param value="classpath:/jpaContext.xml".

Finally I renamed the file to applicationContext.xml and moved it to the WEB-INF directory and changed param value to /WEB-INF/applicationContext.xml, then it worked!

How to read a Parquet file into Pandas DataFrame?

Update: since the time I answered this there has been a lot of work on this look at Apache Arrow for a better read and write of parquet. Also:

There is a python parquet reader that works relatively well:

It will create python objects and then you will have to move them to a Pandas DataFrame so the process will be slower than pd.read_csv for example.

How to get milliseconds from LocalDateTime in Java 8

Date and time as String to Long (millis):

String dateTimeString = "2020-12-12T14:34:18.000Z";

DateTimeFormatter formatter = DateTimeFormatter
                .ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);

LocalDateTime localDateTime = LocalDateTime
        .parse(dateTimeString, formatter);

Long dateTimeMillis = localDateTime

How to set different colors in HTML in one statement?

How about using FONT tag?


H<font color="red">E</font>LLO.

Can't show example here, because this site doesn't allow font tag use.

Span style is fast and easy too.

Add disabled attribute to input element using Javascript

Working code from my sources:


<select name="select_from" disabled>...</select>


var from = jQuery('select[name=select_from]');

//add disabled
from.attr('disabled', 'disabled');

//remove it

Removing the remembered login and password list in SQL Server Management Studio

In XP, the .mru.dat file is in C:\Documents and Settings\Name\Application Data\Microsoft\Microsoft SQL Server\90\Tools\ShellSEM

However, removing it won't do anything.

To remove the list in XP, cut the sqlstudio bin file from C:\Documents and Settings\Name\Application Data\Microsoft\Microsoft SQL Server\100\Tools\Shell and paste it on your desktop.


If it has worked, then delete the sqlstudio bin file from desktop.

Easy :)

How add spaces between Slick carousel item

Just fix css:

/* the slides */
.slick-slider {
    overflow: hidden;
/* the parent */
.slick-list {
    margin: 0 -9px;
/* item */  
    padding: 0 9px;

Updating address bar with new URL without hash or reloading the page

var newurl = window.location.protocol + "//" + + window.location.pathname + '?foo=bar';

How to add number of days in postgresql datetime

For me I had to put the whole interval in single quotes not just the value of the interval.

select id,  
   created_at + interval '1 day' * claim_window as deadline from projects   

Instead of

select id,  
   created_at + interval '1' day * claim_window as deadline from projects   

Postgres Date/Time Functions

Delete all nodes and relationships in neo4j 1.8

if the name of node is for example : abcd then below query will work :

MATCH (n:abcd)

This will only delete the node with label "abcd" and all its relation-ships.

Utils to read resource text file to String (Java)

I've written readResource() methods here, to be able to do it in one simple invocation. It depends on the Guava library, but I like JDK-only methods suggested in other answers and I think I'll change these that way.

How to maximize a window using Python

This makes the window take up the full screen for me, under Ubuntu 12.04 with the TkAgg backend:

    mng = plt.get_current_fig_manager()

Return char[]/string from a function

you can use a static array in your method, to avoid lose of your array when your function ends :

char * createStr() 
    char char1= 'm';
    char char2= 'y';

    static char str[3];  
    str[0] = char1;
    str[1] = char2;
    str[2] = '\0';

    return str;

Edit : As Toby Speight mentioned this approach is not thread safe, and also recalling the function leads to data overwrite that is unwanted in some applications. So you have to save the data in a buffer as soon as you return back from the function. (However because it is not thread safe method, concurrent calls could still make problem in some cases, and to prevent this you have to use lock. capture it when entering the function and release it after copy is done, i prefer not to use this approach because its messy and error prone.)

SQL Server Management Studio missing

Try restarting your computer if you just installed SQL Server and there's no choice in the SQL Server Installation Center to install SQL Server Management Studio.

This choice (see image below) only appeared for me after I installed SQL Server, then restarted my computer:

enter image description here

How to check if an appSettings key exists?

MSDN: Configuration Manager.AppSettings

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


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

require is not defined? Node.js

This can now also happen in Node.js as of version 14.

It happens when you declare your package type as module in your package.json. If you do this, certain CommonJS variables can't be used, including require.

To fix this, remove "type": "module" from your package.json and make sure you don't have any files ending with .mjs.

SQL Server Insert Example

I hope this will help you

Create table :

create table users (id int,first_name varchar(10),last_name varchar(10));

Insert values into the table :

insert into users (id,first_name,last_name) values(1,'Abhishek','Anand');

Loading all images using imread from a given folder

import glob
cv_img = []
for img in glob.glob("Path/to/dir/*.jpg"):
    n= cv2.imread(img)

Fluid or fixed grid system, in responsive design, based on Twitter Bootstrap

Fluid layout in Bootstrap 3.

Unlike Boostrap 2, Bootstrap 3 doesn't have a .container-fluid mixin to make a fluid container. The .container is a fixed width responsive grid layout. In a large screen, there are excessive white spaces in both sides of one's Web page content.

container-fluid is added back in Bootstrap 3.1

A fluid grid layout uses all screen width and works better in large screen. It turns out that it is easy to create a fluid grid layout using Bootstrap 3 mixins. The following line makes a fluid responsive grid layout:


The .container-fixed mixin sets the content to the center of the screen and add paddings. It doesn't specifies a fixed page width.

Another approach is to use Eric Flowers' CSS style

.my-fluid-container {
    padding-left: 15px;
    padding-right: 15px;
    margin-left: auto;
    margin-right: auto;

How do I get the key at a specific index from a Dictionary in Swift?


If you need to use a dictionary’s keys or values with an API that takes an Array instance, initialize a new array with the keys or values property:

let airportCodes = [String](airports.keys) // airportCodes is ["TYO", "LHR"]   
let airportNames = [String](airports.values) // airportNames is ["Tokyo", "London Heathrow"]

C/C++ NaN constant (literal)?

As others have pointed out you are looking for std::numeric_limits<double>::quiet_NaN() although I have to say I prefer the documents. Especially because this statement is a little vague:

Only meaningful if std::numeric_limits::has_quiet_NaN == true.

and it was simple to figure out what this means on this site, if you check their section on std::numeric_limits::has_quiet_NaN it says:

This constant is meaningful for all floating-point types and is guaranteed to be true if std::numeric_limits::is_iec559 == true.

which as explained here if true means your platform supports IEEE 754 standard. This previous thread explains this should be true for most situations.

is not JSON serializable

class CountryListView(ListView):
     model = Country

    def render_to_response(self, context, **response_kwargs):

         return HttpResponse(json.dumps(list(self.get_queryset().values_list('code', flat=True))),mimetype="application/json") 

fixed the problem

also mimetype is important.

Adding a tooltip to an input box

Apart from HTML 5 data-tip You can use css also for making a totally customizable tooltip to be used anywhere throughout your markup.

/* ToolTip classses */ _x000D_
.tooltip {_x000D_
    display: inline-block;    _x000D_
.tooltip .tooltiptext {_x000D_
    width : 320px;_x000D_
    visibility: hidden;_x000D_
    background-color: #FFF;_x000D_
    border: 1px solid #aeaeae;_x000D_
    position: absolute;_x000D_
    z-index: 1;_x000D_
    padding: 5px;_x000D_
    margin-top : -15px; _x000D_
    opacity: 0;_x000D_
    transition: opacity 0.5s;_x000D_
.tooltip .tooltiptext::after {_x000D_
    content: " ";_x000D_
    position: absolute;_x000D_
    top: 5%;_x000D_
    right: 100%;  _x000D_
    margin-top: -5px;_x000D_
    border-width: 5px;_x000D_
    border-style: solid;_x000D_
    border-color: transparent #aeaeae transparent transparent;_x000D_
.tooltip:hover .tooltiptext {_x000D_
    visibility: visible;_x000D_
    opacity: 1;_x000D_
<div class="tooltip">_x000D_
  <input type="text" />_x000D_
  <span class="tooltiptext">_x000D_
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.  </span>_x000D_

How to replace (or strip) an extension from a filename in Python?

Expanding on AnaPana's answer, how to remove an extension using pathlib (Python >= 3.4):

>>> from pathlib import Path

>>> filename = Path('/some/path/somefile.txt')

>>> filename_wo_ext = filename.with_suffix('')

>>> filename_replace_ext = filename.with_suffix('.jpg')

>>> print(filename)

>>> print(filename_wo_ext)

>>> print(filename_replace_ext)

How do I format XML in Notepad++?

Here are most of plugins you can use in Notepad++ to format your XML code.

  • UniversalIndentGUI
    (I recommend this one)

Enable 'text auto update' in plugin manager-> UniversalIndentGUI

  • TextFX
    (this is the tool that most of the users use)


  • XML Tools
    (customized plugin for XML)


How to view DB2 Table structure

Use the below to check the table description for a single table

DESCRIBE TABLE Schema Name.Table Name

join the below tables to check the table description for a multiple tables, join with the table id syscat.tables and syscat.columns

You can also check the details of indexes on the table using the below command describe indexes for table . show detail

NoSql vs Relational database

NoSQL is better than RDBMS because of the following reasons/properities of NoSQL

  1. It supports semi-structured data and volatile data
  2. It does not have schema
  3. Read/Write throughput is very high
  4. Horizontal scalability can be achieved easily
  5. Will support Bigdata in volumes of Terra Bytes & Peta Bytes
  6. Provides good support for Analytic tools on top of Bigdata
  7. Can be hosted in cheaper hardware machines
  8. In-memory caching option is available to increase the performance of queries
  9. Faster development life cycles for developers


To answer "why RDBMS cannot scale", please take a look at RDBMS Overheads pdf written by Stavros Harizopoulos,Daniel J. Abadi,Samuel Madden and Michael Stonebraker

RDBMS's have challenges in handling huge data volumes of Terabytes & Peta bytes. Even if you have Redundant Array of Independent/Inexpensive Disks (RAID) & data shredding, it does not scale well for huge volume of data. You require very expensive hardware.

Logging: Assembling log records and tracking down all changes in database structures slows performance. Logging may not be necessary if recoverability is not a requirement or if recoverability is provided through other means (e.g., other sites on the network).

Locking: Traditional two-phase locking poses a sizeable overhead since all accesses to database structures are governed by a separate entity, the Lock Manager.

Latching: In a multi-threaded database, many data structures have to be latched before they can be accessed. Removing this feature and going to a single-threaded approach has a noticeable performance impact.

Buffer management: A main memory database system does not need to access pages through a buffer pool, eliminating a level of indirection on every record access.

This does not mean that we have to use NoSQL over SQL.

Still, RDBMS is better than NoSQL for the following reasons/properties of RDBMS

  1. Transactions with ACID properties - Atomicity, Consistency, Isolation & Durability
  2. Adherence to Strong Schema of data being written/read
  3. Real time query management ( in case of data size < 10 Tera bytes )
  4. Execution of complex queries involving join & group by clauses

We have to use RDBMS (SQL) and NoSQL (Not only SQL) depending on the business case & requirements

How do I get the last character of a string using an Excel function?

Looks like the answer above was a little incomplete try the following:-


Obviously, this is for cell A2...

What this does is uses a combination of Right and Len - Len is the length of a string and in this case, we want to remove all but one from that... clearly, if you wanted the last two characters you'd change the -1 to -2 etc etc etc.

After the length has been determined and the portion of that which is required - then the Right command will display the information you need.

This works well combined with an IF statement - I use this to find out if the last character of a string of text is a specific character and remove it if it is. See, the example below for stripping out commas from the end of a text string...


Unable to Connect to For Cloning

You can try to clone using the HTTPS protocol. Terminal command:

git clone

Show loading screen when navigating between routes in Angular 2

If you have special logic required for the first route only you can do the following:


    loaded = false;

    constructor(private router: Router....) { => e instanceof NavigationEnd), take(1))
                    .subscribe((e) => {
                       this.loaded = true;
                       alert('loaded - this fires only once');

I had a need for this to hide my page footer, which was otherwise appearing at the top of the page. Also if you only want a loader for the first page you can use this.

Jquery selector input[type=text]')

If you have multiple inputs as text in a form or a table that you need to iterate through, I did this:

var $list = $("#tableOrForm :input[type='text']");

    // Go on with your code.

What I did was I checked each input to see if the type is set to "text", then it'll grab that element and store it in the jQuery list. Then, it would iterate through that list. You can set a temp variable for the current iteration like this:

var $currentItem = $(this);

This will set the current item to the current iteration of your for each loop. Then you can do whatever you want with the temp variable.

Hope this helps anyone!

How to compare oldValues and newValues on React Hooks useEffect?

I just published react-delta which solves this exact sort of scenario. In my opinion, useEffect has too many responsibilities.


  1. It compares all values in its dependency array using
  2. It runs effect/cleanup callbacks based on the result of #1

Breaking Up Responsibilities

react-delta breaks useEffect's responsibilities into several smaller hooks.

Responsibility #1

Responsibility #2

In my experience, this approach is more flexible, clean, and concise than useEffect/useRef solutions.

How can I build XML in C#?

For simple cases, I would also suggest looking at XmlOutput a fluent interface for building Xml.

XmlOutput is great for simple Xml creation with readable and maintainable code, while generating valid Xml. The orginal post has some great examples.

What does "wrong number of arguments (1 for 0)" mean in Ruby?

If you change from using a lambda with one argument to a function with one argument, you will get this error.

For example:

You had:

foobar = lambda do |baz|
  puts baz

and you changed the definition to

def foobar(baz)
  puts baz

And you left your invocation as:

And then you got the message

ArgumentError: wrong number of arguments (0 for 1)

when you really meant:


Why does JS code "var a = document.querySelector('a[data-a=1]');" cause error?

You could use

var a = document.querySelector('a[data-a="1"]');

instead of

var a = document.querySelector('a[data-a=1]');

How to get file creation date/time in Bash/Debian?

Another trick to add to your arsenal is the following:

$ grep -r "Copyright" /<path-to-source-files>/src

Generally speaking, if one changes a file they should claim credit in the “Copyright”. Examine the results for dates, file names, contributors and contact email.

example grep result:

/<path>/src/someobject.h: * Copyright 2007-2012 <creator's name> <creator's email>(at)<some URL>>

How to create a static library with g++?

Create a .o file:

g++ -c header.cpp

add this file to a library, creating library if necessary:

ar rvs header.a header.o

use library:

g++ main.cpp header.a

How to show form input fields based on select value?

<!DOCTYPE html>
<script src=""></script>

function myfun(){

    var data=$("#select").val();

<p>id <input type="text" name="user" id="disp"></p>

<select id="select" onclick="myfun()">
<option name="1"value="1">first</option>
<option name="2"value="2">second</option>


Refresh page after form submitting

You want a form that self submits? Then you just leave the "action" parameter blank.


<form method="post" action="" />

If you want to process the form with this page, then make sure that you have some mechanism in the form or session data to test whether it was properly submitted and to ensure you're not trying to process the empty form.

You might want another mechanism to decide if the form was filled out and submitted but is invalid. I usually use a hidden input field that matches a session variable to decide whether the user has clicked submit or just loaded the page for the first time. By giving a unique value each time and setting the session data to the same value, you can also avoid duplicate submissions if the user clicks submit twice.

How to recover closed output window in netbeans?

Go to window tab - reset windows - run your program. - then right click on bottom of the tab where program running

phpinfo() is not working on my CentOS server

It happened to me as well. On a newly provisioned Red Hat Linux 7 server.

When I run a PHP page, i.e. info.php, I could see plain text PHP scripts instead of executing them.

I just installed PHP:

[root@localhost ~]# yum install php

And then restarted Apache HTTP Server:

[root@localhost ~]# systemctl restart httpd

What do 3 dots next to a parameter type mean in Java?

This is the Java way to pass varargs (variable number arguments).

If you are familiar with C, this is similar to the ... syntax used it the printf function:

int printf(const char * format, ...);

but in a type safe fashion: every argument has to comply with the specified type (in your sample, they should be all String).

This is a simple sample of how you can use varargs:

class VarargSample {

   public static void PrintMultipleStrings(String... strings) {
      for( String s : strings ) {

   public static void main(String[] args) {
      PrintMultipleStrings("Hello", "world");

The ... argument is actually an array, so you could pass a String[] as the parameter.

Compile/run assembler in Linux?

3 syntax (nasm, tasm, gas ) in 1 assembler, yasm.

How do you run a SQL Server query from PowerShell?

Invoke-Sqlcmd -Query "sp_who" -ServerInstance . -QueryTimeout 3

Error: Could not find or load main class in intelliJ IDE

I had this problem and I tried everything under the sun that I could think of and on this site.

None of my Java classes were being picked up after I pulled from a remote branch. All the classes had red Js by their names in the Project Hierarchy, not blue Cs.

In the end, I tried to follow this tutorial and a few steps in tried something not described and fixed the issue:

Here's what I did:

  1. Goto File | Project Structure, or press Crtl+Shift+Alt+S
  2. Select Modules under the Project Settings section.
  3. In the Sources tab click Sources on the 'Mark as:' line.
  4. Click the Apply button.

For some reason, all my classes then had blue C's.

Someone with a better understanding of how IntelliJ and/or IDE's might be able to explain the phenomenon, but all I know is now it can see all the classes and more importantly the main one, and run.

How to comment out a block of code in Python

In vi:

  • Go to top of block and mark it with letter a.
  • Go to bottom of block and mark it with letter b

Then do

:'a,'b s!^!#!

#1064 -You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version

I see two problems:

DOUBLE(10) precision definitions need a total number of digits, as well as a total number of digits after the decimal:

DOUBLE(10,8) would make be ten total digits, with 8 allowed after the decimal.

Also, you'll need to specify your id column as a key :

CREATE TABLE transactions( 
location varchar(50) NOT NULL, 
description varchar(50) NOT NULL, 
category varchar(50) NOT NULL, 
amount double(10,9) NOT NULL, 
type varchar(6) NOT NULL,  
notes varchar(512), 
receipt int(10), 

Best way to use Google's hosted jQuery, but fall back to my hosted library on Google fail

I consider that should escape the last < to \x3C in string. When the browser sees , it considers this to be the end of the script block (since the HTML parser has no idea about JavaScript, it can't distinguish between something that just appears in a string, and something that's actually meant to end the script element). So appearing literally in JavaScript that's inside an HTML page will (in the best case) cause errors, and (in the worst case) be a huge security hole.

<script src=""></script>
<script>window.jQuery || document.write('<script src="js/jquery-2.0.0.min.js">\x3C/script>')</script>

how to iterate through dictionary in a dictionary in django template?

Lets say your data is -

data = {'a': [ [1, 2] ], 'b': [ [3, 4] ],'c':[ [5,6]] }

You can use the data.items() method to get the dictionary elements. Note, in django templates we do NOT put (). Also some users mentioned values[0] does not work, if that is the case then try values.items.


    {% for key, values in data.items %}
        {% for v in values[0] %}
        {% endfor %}
    {% endfor %}

Am pretty sure you can extend this logic to your specific dict.

To iterate over dict keys in a sorted order - First we sort in python then iterate & render in django template.

return render_to_response('some_page.html', {'data': sorted(data.items())})

In template file:

{% for key, value in data %}
        <td> Key: {{ key }} </td> 
        <td> Value: {{ value }} </td>
{% endfor %}

How do I get my Python program to sleep for 50 milliseconds?

There is a module called 'time' which can help you. I know two ways:

  1. sleep

    Sleep (reference) asks the program to wait, and then to do the rest of the code.

    There are two ways to use sleep:

    import time # Import whole time module
    print("0.00 seconds")
    time.sleep(0.05) # 50 milliseconds... make sure you put time. if you import time!
    print("0.05 seconds")

    The second way doesn't import the whole module, but it just sleep.

    from time import sleep # Just the sleep function from module time
    print("0.00 sec")
    sleep(0.05) # Don't put time. this time, as it will be confused. You did
                # not import the whole module
    print("0.05 sec")
  2. Using time since Unix time.

    This way is useful if you need a loop to be running. But this one is slightly more complex.

    time_not_passed = True
    from time import time # You can import the whole module like last time. Just don't forget the time. before to signal it.
    init_time = time() # Or time.time() if whole module imported
    print("0.00 secs")
    while True: # Init loop
        if init_time + 0.05 <= time() and time_not_passed: # Time not passed variable is important as we want this to run once. !!! time.time() if whole module imported :O
            print("0.05 secs")
            time_not_passed = False

Combining multiple commits before pushing in Git

What you want to do is referred to as "squashing" in git. There are lots of options when you're doing this (too many?) but if you just want to merge all of your unpushed commits into a single commit, do this:

git rebase -i origin/master

This will bring up your text editor (-i is for "interactive") with a file that looks like this:

pick 16b5fcc Code in, tests not passing
pick c964dea Getting closer
pick 06cf8ee Something changed
pick 396b4a3 Tests pass
pick 9be7fdb Better comments
pick 7dba9cb All done

Change all the pick to squash (or s) except the first one:

pick 16b5fcc Code in, tests not passing
squash c964dea Getting closer
squash 06cf8ee Something changed
squash 396b4a3 Tests pass
squash 9be7fdb Better comments
squash 7dba9cb All done

Save your file and exit your editor. Then another text editor will open to let you combine the commit messages from all of the commits into one big commit message.

Voila! Googling "git squashing" will give you explanations of all the other options available.

ScalaTest in sbt: is there a way to run a single test without tags?

I wanted to add a concrete example to accompany the other answers

You need to specify the name of the class that you want to test, so if you have the following project (this is a Play project):

Play Project

You can test just the Login tests by running the following command from the SBT console:

test:testOnly *LoginServiceSpec

If you are running the command from outside the SBT console, you would do the following:

sbt "test:testOnly *LoginServiceSpec"

NSRange to Range<String.Index>

I've found the cleanest swift2 only solution is to create a category on NSRange:

extension NSRange {
    func stringRangeForText(string: String) -> Range<String.Index> {
        let start = string.startIndex.advancedBy(self.location)
        let end = start.advancedBy(self.length)
        return Range<String.Index>(start: start, end: end)

And then call it from for text field delegate function:

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    let range = range.stringRangeForText(textField.text)
    let output = textField.text.stringByReplacingCharactersInRange(range, withString: string)

    // your code goes here....

    return true

How remove border around image in css?

Try this:


You can also limitate the scope and only remove border on some images by doing so:

.myClass img{border:0;}

More information about the border css property can by found here.

Edit: Changed border from 0px to 0. As explained in comments, px is redundant for a unit of 0.

Copy data from one existing row to another existing row in SQL?

    c11.completed= c6.completed,
    c11.complete_date = c6.complete_date,
-- rest of columns to be copied
FROM courses c11 inner join courses c6 on
    c11.userID = c6.userID 
    and c11.courseID = 11 and c6.courseID = 6
     -- and any other checks

I have always viewed the From clause of an update, like one of a normal select. Actually if you want to check what will be updated before running the update, you can take replace the update parts with a select c11.*. See my comments on the lame duck's answer.

Android Respond To URL in Intent

I did it! Using <intent-filter>. Put the following into your manifest file:

  <action android:name="android.intent.action.VIEW" />
  <category android:name="android.intent.category.DEFAULT" />
  <category android:name="android.intent.category.BROWSABLE" />
  <data android:host="" android:scheme="http" />

This works perfectly!

Connect Android Studio with SVN

In Android Studio we can get the repositories of svn using the VCS->Subversion and the extract the repository and work on the code

How to put multiple statements in one line?

Here is an example:

for i in range(80, 90): print(i, end=" ") if (i!=89) else print(i)


80 81 82 83 84 85 86 87 88 89

What is the purpose of nameof?

Let's say you need to print the name of a variable in your code. If you write:

int myVar = 10;
print("myVar" + " value is " + myVar.toString());

and then if someone refactors the code and uses another name for myVar, he/she would have to look for the string value in your code and change it accordingly.

Instead, if you write:

print(nameof(myVar) + " value is " + myVar.toString());

It would help to refactor automatically!

How to reverse a singly linked list using only two pointers?

A simple algorithm if you use the linked list as a stack structure:

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

typedef struct list {
    int key;
    char value;
    struct list* next;
} list;
void print(list*);
void add(list**, int, char);
void reverse(list**);
void deleteList(list*);

int main(void) {
    list* head = NULL;
    int i=0;
    while ( i++ < 26 ) add(&head, i, i+'a');
    printf("Before reverse: \n");
    printf("After reverse: \n");

void deleteList(list* l) {

    list* t = l;    
    while ( t != NULL ) {
        list* tmp = t;
        t = t->next;

void print(list* l) {
    list* t = l;
    while ( t != NULL) {
        printf("%d:%c\n", t->key, t->value);
        t = t->next;

void reverse(list** head) {
    list* tmp = *head;
    list* reversed = NULL;
    while ( tmp != NULL ) {
        add(&reversed, tmp->key, tmp->value);
        tmp = tmp->next;
    *head = reversed;

void add(list** head, int k, char v) {

    list* t = calloc(1, sizeof(list));
    t->key = k; t->value = v;
    t->next = *head;
    *head = t;


The performance may be affected since additional function call to the add and malloc so the algorithms of address swaps are better but that one actually creates new list so you can use additional options like sort or remove items if you add a callback function as parameter to the reverse.

How to test REST API using Chrome's extension "Advanced Rest Client"

in the header section you have to write

Authorization: Basic aG9sY67890vbGNpbQ==

where string after basic is the 64bit encoding value of your username:password. php example of getting the header values is: echo "Authorization: Basic " . base64_encode("myUser:myPassword");

n.b: I assumed your authentication method as basic. which can be different as well.

Difference between PACKETS and FRAMES

A packet is a general term for a formatted unit of data carried by a network. It is not necessarily connected to a specific OSI model layer.

For example, in the Ethernet protocol on the physical layer (layer 1), the unit of data is called an "Ethernet packet", which has an Ethernet frame (layer 2) as its payload. But the unit of data of the Network layer (layer 3) is also called a "packet".

A frame is also a unit of data transmission. In computer networking the term is only used in the context of the Data link layer (layer 2).

Another semantical difference between packet and frame is that a frame envelops your payload with a header and a trailer, just like a painting in a frame, while a packet usually only has a header.

But in the end they mean roughly the same thing and the distinction is used to avoid confusion and repetition when talking about the different layers.

checked = "checked" vs checked = true

The element has both an attribute and a property named checked. The property determines the current state.

The attribute is a string, and the property is a boolean. When the element is created from the HTML code, the attribute is set from the markup, and the property is set depending on the value of the attribute.

If there is no value for the attribute in the markup, the attribute becomes null, but the property is always either true or false, so it becomes false.

When you set the property, you should use a boolean value:

document.getElementById('myRadio').checked = true;

If you set the attribute, you use a string:

document.getElementById('myRadio').setAttribute('checked', 'checked');

Note that setting the attribute also changes the property, but setting the property doesn't change the attribute.

Note also that whatever value you set the attribute to, the property becomes true. Even if you use an empty string or null, setting the attribute means that it's checked. Use removeAttribute to uncheck the element using the attribute:


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

UPDATE table1
SET column1 = (SELECT expression1
               FROM table2
               WHERE conditions)
[WHERE conditions];

Center-align a HTML table

margin-left: auto;
margin-right: auto;

This will definitely work. Cheers

Some dates recognized as dates, some dates not recognized. Why?

A workaround for this problem consists in temporarily changing your regional settings, so the date format of the CSV imported file "matches" the regional settings one.

Open Office seems to work in a similar way for that issue, see:

Setting Curl's Timeout in PHP

There is a quirk with this that might be relevant for some people... From the PHP docs comments.

If you want cURL to timeout in less than one second, you can use CURLOPT_TIMEOUT_MS, although there is a bug/"feature" on "Unix-like systems" that causes libcurl to timeout immediately if the value is < 1000 ms with the error "cURL Error (28): Timeout was reached". The explanation for this behavior is:

"If libcurl is built to use the standard system name resolver, that portion of the transfer will still use full-second resolution for timeouts with a minimum timeout allowed of one second."

What this means to PHP developers is "You can't use this function without testing it first, because you can't tell if libcurl is using the standard system name resolver (but you can be pretty sure it is)"

The problem is that on (Li|U)nix, when libcurl uses the standard name resolver, a SIGALRM is raised during name resolution which libcurl thinks is the timeout alarm.

The solution is to disable signals using CURLOPT_NOSIGNAL. Here's an example script that requests itself causing a 10-second delay so you can test timeouts:

if (!isset($_GET['foo'])) {
    // Client
    $ch = curl_init('http://localhost/test/test_timeout.php?foo=bar');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_NOSIGNAL, 1);
    curl_setopt($ch, CURLOPT_TIMEOUT_MS, 200);
    $data = curl_exec($ch);
    $curl_errno = curl_errno($ch);
    $curl_error = curl_error($ch);

    if ($curl_errno > 0) {
        echo "cURL Error ($curl_errno): $curl_error\n";
    } else {
        echo "Data received: $data\n";
} else {
    // Server
    echo "Done.";


How do I loop through a date range?

You can use the DateTime.AddDays() function to add your DayInterval to the StartDate and check to make sure it is less than the EndDate.

Detecting Browser Autofill

I used this solution for same problem.

HTML code should change to this:

<input type="text" name="username" />
<input type="text" name="password" id="txt_password" />

and jQuery code should be in document.ready:


How can I access "static" class variables within class methods in Python?

Define class method:

class Foo(object):
    bar = 1
    def bah(cls):    

Now if bah() has to be instance method (i.e. have access to self), you can still directly access the class variable.

class Foo(object):
    bar = 1
    def bah(self):    

Check if inputs form are empty jQuery

You can do it using simple jQuery loop.

Total code

<!DOCTYPE html>
 <html lang="en">
   <meta charset="UTF-8">
  <script type="text/javascript" src=""></script>
select,textarea,input[type="text"],input[type="password"],input[type="datetime"],input[type="datetime-local"],input[type="date"],input[type="month"],input[type="time"],input[type="week"],input[type="number"],input[type="email"],input[type="url"],input[type="search"],input[type="tel"],input[type="color"],.uneditable-input{background-color:#ffffff;border:1px solid #cccccc;-webkit-border-radius:3px;-moz-border-radius:3px;border-radius:3px;-webkit-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);-moz-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.075);-webkit-transition:border linear 0.2s,box-shadow linear 0.2s;-moz-transition:border linear 0.2s,box-shadow linear 0.2s;-ms-transition:border linear 0.2s,box-shadow linear 0.2s;-o-transition:border linear 0.2s,box-shadow linear 0.2s;transition:border linear 0.2s,box-shadow linear 0.2s;}textarea:focus,input[type="text"]:focus,input[type="password"]:focus,input[type="datetime"]:focus,input[type="datetime-local"]:focus,input[type="date"]:focus,input[type="month"]:focus,input[type="time"]:focus,input[type="week"]:focus,input[type="number"]:focus,input[type="email"]:focus,input[type="url"]:focus,input[type="search"]:focus,input[type="tel"]:focus,input[type="color"]:focus,.uneditable-input:focus{border-color:rgba(82, 168, 236, 0.8);outline:0;outline:thin dotted \9;-webkit-box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);-moz-box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);box-shadow:inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(82,168,236,.6);height: 20px;}
select,input[type="radio"],input[type="checkbox"]{margin:3px 0;*margin-top:0;line-height:normal;cursor:pointer;}
#country{height: 30px;}
    border: 1px solid red !important;
function test()
var isFormValid = true;

$(".bs-example input").each(function(){
    if ($.trim($(this).val()).length == 0){
        isFormValid = false;

    if (!isFormValid) { 
    alert("Please fill in all the required fields (indicated by *)");

return isFormValid;
<div class="bs-example">
<form onsubmit="return test()">
    <div class="form-group">
        <label for="inputEmail">Email</label>
        <input type="text" class="form-control" id="inputEmail" placeholder="Email">
    <div class="form-group">
        <label for="inputPassword">Password</label>
        <input type="password" class="form-control" id="inputPassword" placeholder="Password">
    <button type="submit" class="btn btn-primary">Login</button>

How to find the nearest parent of a Git branch?

This did not work for me when I had done something like develop > release-v1.0.0 > feature-foo, it would go all the way back to develop, note there was a rebase involved, not sure if that is compounding my issue...

The following did give the correct commit hash for me

git log --decorate \
  | grep 'commit' \
  | grep 'origin/' \
  | head -n 2 \
  | tail -n 1 \
  | awk '{ print $2 }' \
  | tr -d "\n"

Can I access a form in the controller?

This answer is a little late, but I stumbled upon a solution that makes everything a LOT easier.

You can actually assign the form name directly to your controller if you're using the controllerAs syntax and then reference it from your "this" variable. Here's how I did it in my code:

I configured the controller via ui-router (but you can do it however you want, even in the HTML directly with something like <div ng-controller="someController as myCtrl">) This is what it might look like in a ui-router configuration:

views: {
            "": {
                templateUrl: "someTemplate.html",
                controller: "someController",
                controllerAs: "myCtrl"

and then in the HTML, you just set the form name as the "controllerAs"."name" like so:

<ng-form name="myCtrl.someForm">
    <!-- example form code here -->
    <input name="firstName" ng-model="myCtrl.user.firstName" required>

now inside your controller you can very simply do this:

        function ($scope) {
            var vm = this;
              // do something

What is a database transaction?

Transaction is an indivisible unit of data processing -All transactions must have the ACID properties:

ie:Atomicity,Consistency,Isolation and Durable Transaction is all or nothing but not intermidiate (it means if you transfer your money from one account to another account,one account have to lose that much and other one have to gain that amount,but if you transfer money from one account and another account is still empty that will be not a transaction)

How to search JSON tree with jQuery

    var GDNUtils = {};

GDNUtils.loadJquery = function () {
    var checkjquery = window.jQuery && jQuery.fn && /^1\.[3-9]/.test(jQuery.fn.jquery);
    if (!checkjquery) {

        var theNewScript = document.createElement("script");
        theNewScript.type = "text/javascript";
        theNewScript.src = "";


        // jQuery MAY OR MAY NOT be loaded at this stage


GDNUtils.searchJsonValue = function (jsonData, keytoSearch, valuetoSearch, keytoGet) {
    alert('here' + jsonData.length.toString());

    $.each(jsonData, function (i, v) {

        if (v[keytoSearch] == valuetoSearch) {



GDNUtils.searchJson = function (jsonData, keytoSearch, valuetoSearch) {
    alert('here' + jsonData.length.toString());
    var row;
    $.each(jsonData, function (i, v) {

        if (v[keytoSearch] == valuetoSearch) {

            row  = v;

    return row;


How to change the colors of a PNG image easily?

Photoshop - right click layer -> blending options -> color overlay change color and save

Reset all changes after last commit in git

How can I undo every change made to my directory after the last commit, including deleting added files, resetting modified files, and adding back deleted files?

  1. You can undo changes to tracked files with:

    git reset HEAD --hard
  2. You can remove untracked files with:

    git clean -f
  3. You can remove untracked files and directories with:

    git clean -fd

    but you can't undo change to untracked files.

  4. You can remove ignored and untracked files and directories

    git clean -fdx

    but you can't undo change to ignored files.

You can also set clean.requireForce to false:

git config --global --add clean.requireForce false

to avoid using -f (--force) when you use git clean.

How to avoid the "Circular view path" exception with Spring MVC test

This has nothing to do with Spring MVC testing.

When you don't declare a ViewResolver, Spring registers a default InternalResourceViewResolver which creates instances of JstlView for rendering the View.

The JstlView class extends InternalResourceView which is

Wrapper for a JSP or other resource within the same web application. Exposes model objects as request attributes and forwards the request to the specified resource URL using a javax.servlet.RequestDispatcher.

A URL for this view is supposed to specify a resource within the web application, suitable for RequestDispatcher's forward or include method.

Emphasis mine. In other words, the view, before rendering, will try to get a RequestDispatcher to which to forward(). Before doing this it checks the following

if (path.startsWith("/") ? uri.equals(path) : uri.equals(StringUtils.applyRelativePath(uri, path))) {
    throw new ServletException("Circular view path [" + path + "]: would dispatch back " +
                        "to the current handler URL [" + uri + "] again. Check your ViewResolver setup! " +
                        "(Hint: This may be the result of an unspecified view, due to default view name generation.)");

where path is the view name, what you returned from the @Controller. In this example, that is preference. The variable uri holds the uri of the request being handled, which is /context/preference.

The code above realizes that if you were to forward to /context/preference, the same servlet (since the same handled the previous) would handle the request and you would go into an endless loop.

When you declare a ThymeleafViewResolver and a ServletContextTemplateResolver with a specific prefix and suffix, it builds the View differently, giving it a path like


ThymeleafView instances locate the file relative to the ServletContext path by using a ServletContextResourceResolver

templateInputStream = resourceResolver.getResourceAsStream(templateProcessingParameters, resourceName);`

which eventually

return servletContext.getResourceAsStream(resourceName);

This gets a resource that is relative to the ServletContext path. It can then use the TemplateEngine to generate the HTML. There's no way an endless loop can happen here.

Rails 4 - passing variable to partial

From the Rails api on PartialRender:

Rendering the default case

If you're not going to be using any of the options like collections or layouts, you can also use the short-hand defaults of render to render partials.


# Instead of <%= render partial: "account" %>
<%= render "account" %>

# Instead of <%= render partial: "account", locals: { account: @buyer } %>
<%= render "account", account: @buyer %>

# @account.to_partial_path returns 'accounts/account', so it can be used to replace:
# <%= render partial: "accounts/account", locals: { account: @account} %>
<%= render @account %>

# @posts is an array of Post instances, so every post record returns 'posts/post' on `to_partial_path`,
# that's why we can replace:
# <%= render partial: "posts/post", collection: @posts %>
<%= render @posts %>

So, you can use pass a local variable size to render as follows:

<%= render @users, size: 50 %>

and then use it in the _user.html.erb partial:

    <%= gravatar_for user, size: size %>
    <%= link_to, user %>

Note that size: size is equivalent to :size => size. Access denied (

Although it is not recommended, but if you really want to let your web application access a folder outside its deployment directory. You need to add following permission in java.policy file (path is as in the reply of Petey B)

permission "your folder path", "write"

In your case it would be

permission "S:/PDSPopulatingProgram/-", "write"

Here /- means any files or sub-folders inside this folder.

Warning: But by doing this, you are inviting some security risk.

How can I pass command-line arguments to a Perl program?

foreach my $arg (@ARGV) {
    print $arg, "\n";

will print each argument.

Font size of TextView in Android application changes on changing font size from native settings

You can use this code:


it solves your problem but you must know that you should respect user decisions. by this, changing text size from device settings will not change this value. so that's why you need to use sp instead of dp. So my suggestion is to review your app with different system font sizes(small,normal,big,...)

SQL Server dynamic PIVOT query?

The below code provides the results which replaces NULL to zero in the output.

Table creation and data insertion:

create table test_table
 date nvarchar(10),
 category char(3),
 amount money

 insert into test_table values ('1/1/2012','ABC',1000.00)
 insert into test_table values ('2/1/2012','DEF',500.00)
 insert into test_table values ('2/1/2012','GHI',800.00)
 insert into test_table values ('2/10/2012','DEF',700.00)
 insert into test_table values ('3/1/2012','ABC',1100.00)

Query to generate the exact results which also replaces NULL with zeros:

@PivotColumnNames AS NVARCHAR(MAX),
@PivotSelectColumnNames AS NVARCHAR(MAX)

--Get distinct values of the PIVOT Column
SELECT @PivotColumnNames= ISNULL(@PivotColumnNames + ',','')
+ QUOTENAME(category)
FROM (SELECT DISTINCT category FROM test_table) AS cat

--Get distinct values of the PIVOT Column with isnull
SELECT @PivotSelectColumnNames 
= ISNULL(@PivotSelectColumnNames + ',','')
+ 'ISNULL(' + QUOTENAME(category) + ', 0) AS '
+ QUOTENAME(category)
FROM (SELECT DISTINCT category FROM test_table) AS cat

--Prepare the PIVOT query using the dynamic 
SET @DynamicPivotQuery = 
N'SELECT date, ' + @PivotSelectColumnNames + '
FROM test_table
pivot(sum(amount) for category in (' + @PivotColumnNames + ')) as pvt';

--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery


enter image description here

How to update two tables in one statement in SQL Server 2005?

It is as simple as this query shown below.

  Table1 T1 join Table2 T2 on =
  T1.LastName='DR. XXXXXX', 
WHERE = '010008'

Refresh a page using JavaScript or HTML

Here are 535 ways to reload a page using javascript, very cool:

Here are the first 20:

location = location
location = location.href
location = window.location
location = self.location
location = window.location.href
location = self.location.href
location = location['href']
location = window['location']
location = window['location'].href
location = window['location']['href']
location = window.location['href']
location = self['location']
location = self['location'].href
location = self['location']['href']
location = self.location['href']

and the last 10:


Original Article

where is create-react-app webpack config and files?

Webpack configuration is being handled by react-scripts. You can find all webpack config inside node_modules react-scripts/config.

And If you want to customize webpack config, you can follow this customize-webpack-config

Time part of a DateTime Field in SQL

Try this in SQL Server 2008:

select *
from some_table t
where convert(time,t.some_datetime_column) = '5pm'

If you want take a random datetime value and adjust it so the time component is 5pm, then in SQL Server 2008 there are a number of ways. First you need start-of-day (e.g., 2011-09-30 00:00:00.000).

  • One technique that works for all versions of Microsoft SQL Server as well as all versions of Sybase is to use convert/3 to convert the datetime value to a varchar that lacks a time component and then back into a datetime value:

    select convert(datetime,convert(varchar,current_timestamp,112),112)

The above gives you start-of-day for the current day.

  • In SQL Server 2008, though, you can say something like this:

    select start_of_day =               t.some_datetime_column
                        - convert(time, t.some_datetime_column ) ,
    from some_table t

    which is likely faster.

Once you have start-of-day, getting to 5pm is easy. Just add 17 hours to your start-of-day value:

select five_pm = dateadd(hour,17, t.some_datetime_column
                   - convert(time,t.some_datetime_column)
from some_table t

React Native fetch() Network Request Failed

in my case i have https url but fetch return Network Request Failed error so i just stringify the body and it s working fun

fetch('', {
  method: 'POST',
  headers: {
    Accept: 'application/json',
    'Content-Type': 'application/json'
  body: JSON.stringify({
    firstParam: 'yourValue',
    secondParam: 'yourOtherValue'

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

I was running into a similar error in pywikipediabot. The .decode method is a step in the right direction but for me it didn't work without adding 'ignore':

ignore_encoding = lambda s: s.decode('utf8', 'ignore')

Ignoring encoding errors can lead to data loss or produce incorrect output. But if you just want to get it done and the details aren't very important this can be a good way to move faster.

Git: Recover deleted (remote) branch

If your organization uses JIRA or another similar system that is tied into git, you can find the commits listed on the ticket itself and click the links to the code changes. Github deletes the branch but still has the commits available for cherry-picking.

How to get the version of ionic framework?

Ionic projects structure are similar as Angular projects, you can get use

ionic info

command to Print project, system, and environment information.

enter image description here

This command is an easy way to share information about your setup. If applicable, be sure to run ionic info within your project directory to display even more information.

We may use --json after ionic info to print system/environment info in JSON format

ionic info --json

CSS word-wrapping in div

As Andrew said, your text should be doing just that.

There is one instance that I can think of that will behave in the manner you suggest, and that is if you have the whitespace property set.

See if you don't have the following in your CSS somewhere:

white-space: nowrap

That will cause text to continue on the same line until interrupted by a line break.

OK, my apologies, not sure if edited or added the mark-up afterwards (didn't see it at first).

The overflow-x property is what's causing the scroll bar to appear. Remove that and the div will adjust to as high as it needs to be to contain all your text.

What is the PostgreSQL equivalent for ISNULL()


SELECT COALESCE(NULLIF(field, ''), another_field) FROM table_name

facebook Uncaught OAuthException: An active access token must be used to query information about the current user

Had the same problem and the solution was to reauthorize the user. Check it here:



  $config = array(
      'appId' => '1424980371051918',
      'secret' => '2ed5c1260daa4c44673ba6fbc348c67d',
      'fileUpload' => false // optional

  $facebook = new Facebook($config);

//Authorizing app:

<a href="<?php echo $facebook->getLoginUrl(); ?>">Login con fb</a>

Saved project and opened on my test enviroment and it worked again. As I did, you can comment your previous code and try.

IN Clause with NULL or IS NULL

Null refers to an absence of data. Null is formally defined as a value that is unavailable, unassigned, unknown or inapplicable (OCA Oracle Database 12c, SQL Fundamentals I Exam Guide, p87). So, you may not see records with columns containing null values when said columns are restricted using an "in" or "not in" clauses.

How to initialise memory with new operator in C++?

Assuming that you really do want an array and not a std::vector, the "C++ way" would be this

#include <algorithm> 

int* array = new int[n]; // Assuming "n" is a pre-existing variable

std::fill_n(array, n, 0); 

But be aware that under the hood this is still actually just a loop that assigns each element to 0 (there's really not another way to do it, barring a special architecture with hardware-level support).

Select Last Row in the Table

You'll need to order by the same field you're ordering by now, but descending. As an example, if you have a time stamp when the upload was done called upload_time, you'd do something like this;

For Pre-Laravel 4

return DB::table('files')->order_by('upload_time', 'desc')->first();

For Laravel 4 and onwards

return DB::table('files')->orderBy('upload_time', 'desc')->first();

For Laravel 5.7 and onwards

return DB::table('files')->latest('upload_time')->first();

This will order the rows in the files table by upload time, descending order, and take the first one. This will be the latest uploaded file.

What causing this "Invalid length for a Base-64 char array"

As others have mentioned this can be caused when some firewalls and proxies prevent access to pages containing a large amount of ViewState data.

ASP.NET 2.0 introduced the ViewState Chunking mechanism which breaks the ViewState up into manageable chunks, allowing the ViewState to pass through the proxy / firewall without issue.

To enable this feature simply add the following line to your web.config file.

<pages maxPageStateFieldLength="4000">

This should not be used as an alternative to reducing your ViewState size but it can be an effective backstop against the "Invalid length for a Base-64 char array" error resulting from aggressive proxies and the like.

How can I create a memory leak in Java?

I recently encountered a memory leak situation caused in a way by log4j.

Log4j has this mechanism called Nested Diagnostic Context(NDC) which is an instrument to distinguish interleaved log output from different sources. The granularity at which NDC works is threads, so it distinguishes log outputs from different threads separately.

In order to store thread specific tags, log4j's NDC class uses a Hashtable which is keyed by the Thread object itself (as opposed to say the thread id), and thus till the NDC tag stays in memory all the objects that hang off of the thread object also stay in memory. In our web application we use NDC to tag logoutputs with a request id to distinguish logs from a single request separately. The container that associates the NDC tag with a thread, also removes it while returning the response from a request. The problem occurred when during the course of processing a request, a child thread was spawned, something like the following code:

pubclic class RequestProcessor {
    private static final Logger logger = Logger.getLogger(RequestProcessor.class);
    public void doSomething()  {
        final List<String> hugeList = new ArrayList<String>(10000);
        new Thread() {
           public void run() {
     "Child thread spawned")
               for(String s:hugeList) {

So an NDC context was associated with inline thread that was spawned. The thread object that was the key for this NDC context, is the inline thread which has the hugeList object hanging off of it. Hence even after the thread finished doing what it was doing, the reference to the hugeList was kept alive by the NDC context Hastable, thus causing a memory leak.

Tracking changes in Windows registry

Can monitor registry changes made by specific program.

UPDATE: Just download NirLauncher (which includes all applications from NirSoft). It is one of the best additions to your Windows toolbox.

How to determine one year from now in Javascript

As setYear() is deprecated, correct variant is:

// plus 1 year
new Date().setFullYear(new Date().getFullYear() + 1)
// plus 1 month
new Date().setMonth(new Date().getMonth() + 1)
// plus 1 day
new Date().setDate(new Date().getDate() + 1)

All examples return Unix timestamp, if you want to get Date object - just wrap it with another new Date(...)

How to use a WSDL

I would fire up Visual Studio, create a web project (or console app - doesn't matter).

For .Net Standard:

  1. I would right-click on the project and pick "Add Service Reference" from the Add context menu.
  2. I would click on Advanced, then click on Add Service Reference.
  3. I would get the complete file path of the wsdl and paste into the address bar. Then fire the Arrow (go button).
  4. If there is an error trying to load the file, then there must be a broken and unresolved url the file needs to resolve as shown below: enter image description here Refer to this answer for information on how to fix: Stackoverflow answer to: Unable to create service reference for wsdl file

If there is no error, you should simply set the NameSpace you want to use to access the service and it'll be generated for you.

For .Net Core

  1. I would right click on the project and pick Connected Service from the Add context menu.
  2. I would select Microsoft WCF Web Service Reference Provider from the list.
  3. I would press browse and select the wsdl file straight away, Set the namespace and I am good to go. Refer to the error fix url above if you encounter any error.

Any of the methods above will generate a simple, very basic WCF client for you to use. You should find a "YourservicenameClient" class in the generated code.

For reference purpose, the generated cs file can be found in your Obj/debug(or release)/XsdGeneratedCode and you can still find the dlls in the TempPE folder.

The created Service(s) should have methods for each of the defined methods on the WSDL contract.

Instantiate the client and call the methods you want to call - that's all there is!

YourServiceClient client = new YourServiceClient();

If you need to specify the remote URL (not using the one created by default), you can easily do this in the constructor of the proxy client:

YourServiceClient client = new YourServiceClient("configName", "remoteURL");

where configName is the name of the endpoint to use (you will use all the settings except the URL), and the remoteURL is a string representing the URL to connect to (instead of the one contained in the config).

Using iText to convert HTML to PDF

I have ended up using ABCPdf from webSupergoo. It works really well and for about $350 it has saved me hours and hours based on your comments above. Thanks again Daniel and Bratch for your comments.

How to split elements of a list?

I had to split a list for feature extraction in two parts lt,lc:

ltexts = ((df4.ix[0:,[3,7]]).values).tolist()

featsets = [(act_features((lt)),lc) 
              for lc, lt in ltexts]

def act_features(atext):
  features = {}
  for word in nltk.word_tokenize(atext):
  return features

How to predict input image using trained model in Keras?

keras predict_classes (docs) outputs A numpy array of class predictions. Which in your model case, the index of neuron of highest activation from your last(softmax) layer. [[0]] means that your model predicted that your test data is class 0. (usually you will be passing multiple image, and the result will look like [[0], [1], [1], [0]] )

You must convert your actual label (e.g. 'cancer', 'not cancer') into binary encoding (0 for 'cancer', 1 for 'not cancer') for binary classification. Then you will interpret your sequence output of [[0]] as having class label 'cancer'

How do I create batch file to rename large number of files in a folder?

@ECHO off & SETLOCAL EnableDelayedExpansion

SET "_dir=" REM Must finish with '\'
SET "_ext=jpg"
SET "_toEdit=Vacation2010"
SET "_with=December"
FOR %%f IN ("%_dir%*.%_ext%") DO (
    CALL :modifyString "%_toEdit%" "%_with%" "%%~Nf" fileName 
    RENAME "%%f" "!fileName!%%~Xf"
GOTO end

:modifyString what with in toReturn
    SET "__in=%~3"
    SET "__in=!__in:%~1=%~2!"
    IF NOT "%~4" == "" (
        SET %~4=%__in%
    ) ELSE (
        ECHO %__in%
    EXIT /B


This script allows you to change the name of all the files that contain Vacation2010 with the same name, but with December instead of Vacation2010.

If you copy and paste the code, you have to save the .bat in the same folder of the photos. If you want to save the script in another directory [E.G. you have a favorite folder for the utilities] you have to change the value of _dir with the path of the photos.

If you have to do the same work for other photos [or others files changig _ext] you have to change the value of _toEdit with the string you want to change [or erase] and the value of _with with the string you want to put instead of _toEdit [SET "_with=" if you simply want to erase the string specified in _toEdit].

Bootstrap 3 2-column form layout

As mentioned earlier, you can use the grid system to layout your inputs and labels anyway that you want. The trick is to remember that you can use rows within your columns to break them into twelfths as well.

The example below is one possible way to accomplish your goal and will put the two text boxes near Label3 on the same line when the screen is small or larger.

<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
    <meta charset="utf-8">_x000D_
    <meta http-equiv="X-UA-Compatible" content="IE=edge">_x000D_
    <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
<link href="" rel="stylesheet"/>_x000D_
    <!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->_x000D_
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->_x000D_
    <!--[if lt IE 9]>_x000D_
      <script src=""></script>_x000D_
      <script src=""></script>_x000D_
    <div class="row">_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6">_x000D_
            <div class="row">_x000D_
                <label class="col-xs-12">Label3</label>_x000D_
            <div class="row">_x000D_
                <div class="col-xs-12 col-sm-6">_x000D_
                    <input class="form-control" type="text"/>_x000D_
                <div class="col-xs-12 col-sm-6">_x000D_
                    <input class="form-control" type="text"/>_x000D_
        <div class="col-xs-6 form-group">_x000D_
            <input class="form-control" type="text"/>_x000D_
<script src=""></script>_x000D_
<script src=""></script>_x000D_

TCP vs UDP on video stream

Besides all the other reasons, UDP can use multicast. Supporting 1000s of TCP users all transmitting the same data wastes bandwidth. However, there is another important reason for using TCP.

TCP can much more easily pass through firewalls and NATs. Depending on your NAT and operator, you may not even be able to receive a UDP stream due to problems with UDP hole punching.

How to use mongoimport to import csv

Just use this after executing mongoimport

It will return number of objects imported

use db

will return the number of objects.

How to Copy Text to Clip Board in Android?

@SuppressLint({ "NewApi", "NewApi", "NewApi", "NewApi" })
public void onClickCopy(View v) {   // User-defined onClick Listener
    int sdk_Version = android.os.Build.VERSION.SDK_INT;
    if(sdk_Version < android.os.Build.VERSION_CODES.HONEYCOMB) {
        android.text.ClipboardManager clipboard = (android.text.ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
        clipboard.setText(textView.getText().toString());   // Assuming that you are copying the text from a TextView
        Toast.makeText(getApplicationContext(), "Copied to Clipboard!", Toast.LENGTH_SHORT).show();
    else { 
        android.content.ClipboardManager clipboard = (android.content.ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE); 
        android.content.ClipData clip = android.content.ClipData.newPlainText("Text Label", textView.getText().toString());
        Toast.makeText(getApplicationContext(), "Copied to Clipboard!", Toast.LENGTH_SHORT).show();

What's the difference between disabled="disabled" and readonly="readonly" for HTML form input fields?

If the value of a disabled textbox needs to be retained when a form is cleared (reset), disabled = "disabled" has to be used, as read-only textbox will not retain the value

For Example:



<input type="text" id="disabledText" name="randombox" value="demo" disabled="disabled" />

Reset button

<button type="reset" id="clearButton">Clear</button>

In the above example, when Clear button is pressed, disabled text value will be retained in the form. Value will not be retained in the case of input type = "text" readonly="readonly"

How does the SQL injection from the "Bobby Tables" XKCD comic work?

It drops the students table.

The original code in the school's program probably looks something like

q = "INSERT INTO Students VALUES ('" + FNMName.Text + "', '" + LName.Text + "')";

This is the naive way to add text input into a query, and is very bad, as you will see.

After the values from the first name, middle name textbox FNMName.Text (which is Robert'); DROP TABLE STUDENTS; --) and the last name textbox LName.Text (let's call it Derper) are concatenated with the rest of the query, the result is now actually two queries separated by the statement terminator (semicolon). The second query has been injected into the first. When the code executes this query against the database, it will look like this

INSERT INTO Students VALUES ('Robert'); DROP TABLE Students; --', 'Derper')

which, in plain English, roughly translates to the two queries:

Add a new record to the Students table with a Name value of 'Robert'


Delete the Students table

Everything past the second query is marked as a comment: --', 'Derper')

The ' in the student's name is not a comment, it's the closing string delimiter. Since the student's name is a string, it's needed syntactically to complete the hypothetical query. Injection attacks only work when the SQL query they inject results in valid SQL.

Edited again as per dan04's astute comment

SQL: How To Select Earliest Row

SELECT company
   , workflow
   , MIN(date)
FROM workflowTable
GROUP BY company
       , workflow

Displaying the build date

The above method can be tweaked for assemblies already loaded within the process by using the file's image in memory (as opposed to re-reading it from storage):

using System;
using System.Runtime.InteropServices;
using Assembly = System.Reflection.Assembly;

static class Utils
    public static DateTime GetLinkerDateTime(this Assembly assembly, TimeZoneInfo tzi = null)
        // Constants related to the Windows PE file format.
        const int PE_HEADER_OFFSET = 60;
        const int LINKER_TIMESTAMP_OFFSET = 8;

        // Discover the base memory address where our assembly is loaded
        var entryModule = assembly.ManifestModule;
        var hMod = Marshal.GetHINSTANCE(entryModule);
        if (hMod == IntPtr.Zero - 1) throw new Exception("Failed to get HINSTANCE.");

        // Read the linker timestamp
        var offset = Marshal.ReadInt32(hMod, PE_HEADER_OFFSET);
        var secondsSince1970 = Marshal.ReadInt32(hMod, offset + LINKER_TIMESTAMP_OFFSET);

        // Convert the timestamp to a DateTime
        var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
        var linkTimeUtc = epoch.AddSeconds(secondsSince1970);
        var dt = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tzi ?? TimeZoneInfo.Local);
        return dt;

Git: Could not resolve host error while cloning remote repository in git

In my case I open a new terminal and problem solved. I don't know exactly what caused the problem in the first place though.

Detect backspace and del on "input" event?

With jQuery

The event.which property normalizes event.keyCode and event.charCode. It is recommended to watch event.which for keyboard key input.

jQuery('#input').on('keydown', function(e) {
    if( e.which == 8 || e.which == 46 ) return false;

Get value from text area


textarea.value would be pure JavaScript, but here you're trying to use JavaScript as a not-valid jQuery method (.value).

What is mapDispatchToProps?

I feel like none of the answers have crystallized why mapDispatchToProps is useful.

This can really only be answered in the context of the container-component pattern, which I found best understood by first reading:Container Components then Usage with React.

In a nutshell, your components are supposed to be concerned only with displaying stuff. The only place they are supposed to get information from is their props.

Separated from "displaying stuff" (components) is:

  • how you get the stuff to display,
  • and how you handle events.

That is what containers are for.

Therefore, a "well designed" component in the pattern look like this:

class FancyAlerter extends Component {
    sendAlert = () => {

    render() {
          <h1>Today's Fancy Alert is {this.props.fancyInfo}</h1>
          <Button onClick={sendAlert}/>

See how this component gets the info it displays from props (which came from the redux store via mapStateToProps) and it also gets its action function from its props: sendTheAlert().

That's where mapDispatchToProps comes in: in the corresponding container

// FancyButtonContainer.js

function mapDispatchToProps(dispatch) {
        sendTheAlert: () => {dispatch(ALERT_ACTION)}

function mapStateToProps(state) {
    return({fancyInfo: "Fancy this:" + state.currentFunnyString})

export const FancyButtonContainer = connect(
    mapStateToProps, mapDispatchToProps)(

I wonder if you can see, now that it's the container 1 that knows about redux and dispatch and store and state and ... stuff.

The component in the pattern, FancyAlerter, which does the rendering doesn't need to know about any of that stuff: it gets its method to call at onClick of the button, via its props.

And ... mapDispatchToProps was the useful means that redux provides to let the container easily pass that function into the wrapped component on its props.

All this looks very like the todo example in docs, and another answer here, but I have tried to cast it in the light of the pattern to emphasize why.

(Note: you can't use mapStateToProps for the same purpose as mapDispatchToProps for the basic reason that you don't have access to dispatch inside mapStateToProp. So you couldn't use mapStateToProps to give the wrapped component a method that uses dispatch.

I don't know why they chose to break it into two mapping functions - it might have been tidier to have mapToProps(state, dispatch, props) IE one function to do both!

1 Note that I deliberately explicitly named the container FancyButtonContainer, to highlight that it is a "thing" - the identity (and hence existence!) of the container as "a thing" is sometimes lost in the shorthand

export default connect(...) ????????????

syntax that is shown in most examples Server returned HTTP response code: 500

I have encountered the same problem and found out the solution.

You may look within the first server response and see if the server sent you a cookie.

To check if the server sent you a cookie, you can use HttpURLConnection#getHeaderFields() and look for headers named "Set-Cookie".

If existing, here's the solution for your problem. 100% Working for this case!

+1 if it worked for you.

Python error: AttributeError: 'module' object has no attribute

More accurately, your mod1 and lib directories are not modules, they are packages. The file is a module.

Python does not automatically import subpackages or modules. You have to explicitly do it, or "cheat" by adding import statements in the initializers.

>>> import lib
>>> dir(lib)
['__builtins__', '__doc__', '__file__', '__name__', '__package__', '__path__']
>>> import lib.pkg1
>>> import lib.pkg1.mod11
>>> lib.pkg1.mod11.mod12()

An alternative is to use the from syntax to "pull" a module from a package into you scripts namespace.

>>> from lib.pkg1 import mod11

Then reference the function as simply mod11.mod12().

handle textview link click in my android app

Here is a more generic solution based on @Arun answer

public abstract class TextViewLinkHandler extends LinkMovementMethod {

    public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {
        if (event.getAction() != MotionEvent.ACTION_UP)
            return super.onTouchEvent(widget, buffer, event);

        int x = (int) event.getX();
        int y = (int) event.getY();

        x -= widget.getTotalPaddingLeft();
        y -= widget.getTotalPaddingTop();

        x += widget.getScrollX();
        y += widget.getScrollY();

        Layout layout = widget.getLayout();
        int line = layout.getLineForVertical(y);
        int off = layout.getOffsetForHorizontal(line, x);

        URLSpan[] link = buffer.getSpans(off, off, URLSpan.class);
        if (link.length != 0) {
        return true;

    abstract public void onLinkClick(String url);

To use it just implement onLinkClick of TextViewLinkHandler class. For instance:

    textView.setMovementMethod(new TextViewLinkHandler() {
        public void onLinkClick(String url) {
            Toast.makeText(textView.getContext(), url, Toast.LENGTH_SHORT).show();

Calculate the center point of multiple latitude/longitude coordinate pairs

If you wish to take into account the ellipsoid being used you can find the formulae here

see Annexe B

The document contains lots of other useful stuff


How to check edittext's text is email address or not?

A simple method

    private boolean isValidEmail(String email)
    String emailRegex ="^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
        return true;
    return false;

How to display pdf in php

There are quite a few options that can be used: (both tested).

Here are two ways.

header("Content-type: application/pdf");
header("Content-Disposition: inline; filename=filename.pdf");

or: (note the escaped double-quotes). The same need to be use when assigning a name to it.


echo "<iframe src=\"file.pdf\" width=\"100%\" style=\"height:100%\"></iframe>";


I.e.: name="myiframe" id="myiframe"

would need to be changed to:

name=\"myiframe\" id=\"myiframe\" inside PHP.

Be sure to have a look at: this answer on SO for more options on the subject.

Footnote: There are known issues when trying to view PDF files in Windows 8. Installing Adobe Acrobat Reader is a better method to view these types of documents if no browser plug-ins are installed.

android:drawableLeft margin and/or padding

Make your drawable resources.xml

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="">
    <item android:state_checked="true">
        <inset android:drawable="@drawable/small_m" android:insetLeft="10dp" android:insetTop="10dp" />
        <inset android:drawable="@drawable/small_p" android:insetLeft="10dp" android:insetTop="10dp" />

The type java.lang.CharSequence cannot be resolved in package declaration

Make your Project and Workspace to point to JDK7 which will resolve the issue. has given ways to modify Compliance and Facet level changes.

react-router - pass props to handler component

this is probably the best way to use react-router-dom with a cookie handler

in index.js

import React, { Component } from 'react'
import {Switch,Route,Redirect} from "react-router-dom"
import {RouteWithLayout} from "./cookieCheck"

import Login from "../app/pages/login"
import DummyLayout from "../app/layouts/dummy"
import DummyPage from "../app/pages/dummy" 

export default ({props})=>{
        <Route path="/login" component={Login} />
        <RouteWithLayout path="/dummy" layout={DummyLayout} component={DummyPage} 
        <Redirect from="/*" to="/login" />

and use a cookieCheck

import React , {createElement} from 'react'
import {Route,Redirect} from "react-router-dom"
import {COOKIE,getCookie} from "../services/"

export const RouteWithLayout = ({layout,component,})=>{
    if(getCookie(COOKIE)==null)return <Redirect to="/login"/>
        return (
        <Route {} render={(props) =>
            createElement(layout, {...props,}, createElement(component, 

Found shared references to a collection org.hibernate.HibernateException

Explanation on practice. If you try to save your object, e.g.:

Set<Folder> folders = message.getFolders();

you don't need to set updated object to a parent object:


Simple save your parent object like:

Set<Folder> folders = message.getFolders();
   // Not set updated object here

get all keys set in memcached

Base on @mu ? answer here. I've written a cache dump script.

The script dumps all the content of a memcached server. It's tested with Ubuntu 12.04 and a localhost memcached, so your milage may vary.

#!/usr/bin/env bash

echo 'stats items'  \
| nc localhost 11211  \
| grep -oe ':[0-9]*:'  \
| grep -oe '[0-9]*'  \
| sort  \
| uniq  \
| xargs -L1 -I{} bash -c 'echo "stats cachedump {} 1000" | nc localhost 11211'

What it does, it goes through all the cache slabs and print 1000 entries of each.

Please be aware of certain limits of this script i.e. it may not scale for a 5GB cache server for example. But it's useful for debugging purposes on a local machine.

Float a DIV on top of another DIV

I know this post is little bit old but here is a potential solution for anyone who has the same problem:

First, I would change the CSS display for #popup to "none" instead of "hidden".

Second, I would change the HTML as follow:

<div id="overlay-back"></div>
<div id="popup">
    <div style="position: relative;">
        <img class="close-image" src="images/closebtn.png" />
        <span><img src="images/load_sign.png" width="400" height="566" /></span>

And for Style as follow:

   display: block;
   float: right;
   cursor: pointer;
   z-index: 3;
   position: absolute;
   right: 0;
   top: 0;

I got this idea from this website ( A very good example on how to position elements,:

How to position a div on top of another div

I hope this helps,


How to draw an empty plot?

Adam, following your comment above ("I wanted the empty plot to serve as filler in a multiplot (mfrow) plot."), what you actually want is the mfg option


- which controls where you want to put the next plot. For instance, to put a plot in the middle of a 3x3 multiplot, do


Named placeholders in string formatting

You should have a look at the official ICU4J library. It provides a MessageFormat class similar to the one available with the JDK but this former supports named placeholders.

Unlike other solutions provided on this page. ICU4j is part of the ICU project that is maintained by IBM and regularly updated. In addition, it supports advanced use cases such as pluralization and much more.

Here is a code example:

MessageFormat messageFormat =
        new MessageFormat("Publication written by {author}.");

Map<String, String> args = Map.of("author", "John Doe");


Is there a Newline constant defined in Java like Environment.Newline in C#?

As of Java 7:


Java API : System.lineSeparator

Returns the system-dependent line separator string. It always returns the same value - the initial value of the system property line.separator. On UNIX systems, it returns "\n"; on Microsoft Windows systems it returns "\r\n".

Convert HttpPostedFileBase to byte[]

You can read it from the input stream:

public ActionResult ManagePhotos(ManagePhotos model)
    if (ModelState.IsValid)
        byte[] image = new byte[model.File.ContentLength];
        model.File.InputStream.Read(image, 0, image.Length); 

        // TODO: Do something with the byte array here

And if you intend to directly save the file to the disk you could use the model.File.SaveAs method. You might find the following blog post useful.

Add a CSS border on hover without moving the element

Add a border to the regular item, the same color as the background, so that it cannot be seen. That way the item has a border: 1px whether it is being hovered or not.

How can I reduce the waiting (ttfb) time

TTFB is something that happens behind the scenes. Your browser knows nothing about what happens behind the scenes.

You need to look into what queries are being run and how the website connects to the server.

This article might help understand TTFB, but otherwise you need to dig deeper into your application.

Retrieving JSON Object Literal from HttpServletRequest

are you looking for this ?

protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    StringBuilder sb = new StringBuilder();
    BufferedReader reader = request.getReader();
    try {
        String line;
        while ((line = reader.readLine()) != null) {
    } finally {

How to get Database Name from Connection String using SqlConnectionStringBuilder

this gives you the Xact;

System.Data.SqlClient.SqlConnectionStringBuilder connBuilder = new System.Data.SqlClient.SqlConnectionStringBuilder();

connBuilder.ConnectionString = connectionString;

string server = connBuilder.DataSource;           //-> this gives you the Server name.
string database = connBuilder.InitialCatalog;     //-> this gives you the Db name.

How do I get the entity that represents the current user in Symfony2?


Turn a simple socket into an SSL socket

There are several steps when using OpenSSL. You must have an SSL certificate made which can contain the certificate with the private key be sure to specify the exact location of the certificate (this example has it in the root). There are a lot of good tutorials out there.

Some includes:

#include <openssl/applink.c>
#include <openssl/bio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>

You will need to initialize OpenSSL:

void InitializeSSL()

void DestroySSL()

void ShutdownSSL()

Now for the bulk of the functionality. You may want to add a while loop on connections.

int sockfd, newsockfd;
SSL_CTX *sslctx;

sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd< 0)
    //Log and Error
struct sockaddr_in saiServerAddress;
bzero((char *) &saiServerAddress, sizeof(saiServerAddress));
saiServerAddress.sin_family = AF_INET;
saiServerAddress.sin_addr.s_addr = serv_addr;
saiServerAddress.sin_port = htons(aPortNumber);

bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));

newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

sslctx = SSL_CTX_new( SSLv23_server_method());
SSL_CTX_set_options(sslctx, SSL_OP_SINGLE_DH_USE);
int use_cert = SSL_CTX_use_certificate_file(sslctx, "/serverCertificate.pem" , SSL_FILETYPE_PEM);

int use_prv = SSL_CTX_use_PrivateKey_file(sslctx, "/serverCertificate.pem", SSL_FILETYPE_PEM);

cSSL = SSL_new(sslctx);
SSL_set_fd(cSSL, newsockfd );
//Here is the SSL Accept portion.  Now all reads and writes must use SSL
ssl_err = SSL_accept(cSSL);
if(ssl_err <= 0)
    //Error occurred, log and close down ssl

You are then able read or write using:

SSL_read(cSSL, (char *)charBuffer, nBytesToRead);
SSL_write(cSSL, "Hi :3\n", 6);

Update The SSL_CTX_new should be called with the TLS method that best fits your needs in order to support the newer versions of security, instead of SSLv23_server_method(). See: OpenSSL SSL_CTX_new description

TLS_method(), TLS_server_method(), TLS_client_method(). These are the general-purpose version-flexible SSL/TLS methods. The actual protocol version used will be negotiated to the highest version mutually supported by the client and the server. The supported protocols are SSLv3, TLSv1, TLSv1.1, TLSv1.2 and TLSv1.3.

How to add reference to a method parameter in javadoc?

The correct way of referring to a method parameter is like this:

enter image description here

Comparing two NumPy arrays for equality, element-wise

If you want to check if two arrays have the same shape AND elements you should use np.array_equal as it is the method recommended in the documentation.

Performance-wise don't expect that any equality check will beat another, as there is not much room to optimize comparing two elements. Just for the sake, i still did some tests.

import numpy as np
import timeit

A = np.zeros((300, 300, 3))
B = np.zeros((300, 300, 3))
C = np.ones((300, 300, 3))

timeit.timeit(stmt='(A==B).all()', setup='from __main__ import A, B', number=10**5)
timeit.timeit(stmt='np.array_equal(A, B)', setup='from __main__ import A, B, np', number=10**5)
timeit.timeit(stmt='np.array_equiv(A, B)', setup='from __main__ import A, B, np', number=10**5)
> 51.5094
> 52.555
> 52.761

So pretty much equal, no need to talk about the speed.

The (A==B).all() behaves pretty much as the following code snippet:

x = [1,2,3]
y = [1,2,3]
print all([x[i]==y[i] for i in range(len(x))])
> True

Android: how to parse URL String with spaces to URI object?

I wrote this function:

public static String encode(@NonNull String uriString) {
    if (TextUtils.isEmpty(uriString)) {"Uri string cannot be empty!");
        return uriString;
    // getQueryParameterNames is not exist then cannot iterate on queries
    if (Build.VERSION.SDK_INT < 11) {
        return uriString;

    // Check if uri has valid characters
    // See
    Pattern allowedUrlCharacters = Pattern.compile("([A-Za-z0-9_.~:/?\\#\\[\\]@!$&'()*+,;" +
    Matcher matcher = allowedUrlCharacters.matcher(uriString);
    String validUri = null;
    if (matcher.find()) {
        validUri =;
    if (TextUtils.isEmpty(validUri) || uriString.length() == validUri.length()) {
        return uriString;

    // The uriString is not encoded. Then recreate the uri and encode it this time
    Uri uri = Uri.parse(uriString);
    Uri.Builder uriBuilder = new Uri.Builder()
    for (String path : uri.getPathSegments()) {
    for (String key : uri.getQueryParameterNames()) {
        uriBuilder.appendQueryParameter(key, uri.getQueryParameter(key));
    String correctUrl =;
    return correctUrl;

Getting a slice of keys from a map


package main

import (

func main() {
    mapEg := map[string]string{"c":"a","a":"c","b":"b"}
    keys := make([]string, 0, len(mapEg))
    for k := range mapEg {
        keys = append(keys, k)

What is the difference between SQL and MySQL?

SQL is the actual language that as defined by the ISO and ANSI. Here is a link to the Wikipedia article. MySQL is a specific implementation of this standard. I believe Oracle bought the company that originally developed MySQL. Other companies also have their own implementations of the SQL standard.

jQuery get mouse position within an element

I would suggest this:

e.pageX - this.getBoundingClientRect().left

How to check if an email address exists without sending an email?

function EmailValidation($email)
    $email = htmlspecialchars(stripslashes(strip_tags($email))); //parse unnecessary characters to prevent exploits
    if (eregi('[a-z||0-9]@[a-z||0-9].[a-z]', $email)) {
        //checks to make sure the email address is in a valid format
        $domain = explode( "@", $email ); //get the domain name
        if (@fsockopen ($domain[1],80,$errno,$errstr,3)) {
            //if the connection can be established, the email address is probably valid
            echo "Domain Name is valid ";
            return true;
        } else {
            echo "Con not a email domian";
            return false; //if a connection cannot be established return false
        return false; //if email address is an invalid format return false

Set Text property of asp:label in Javascript PROPER way

Since you have updated your label client side, you'll need a post-back in order for you're server side code to reflect the changes.

If you do not know how to do this, here is how I've gone about it in the past.

Create a hidden field:

<input type="hidden" name="__EVENTTARGET" id="__EVENTTARGET" value="" />

Create a button that has both client side and server side functions attached to it. You're client side function will populate your hidden field, and the server side will read it. Be sure you're client side is being called first.

<asp:Button ID="_Submit" runat="server" Text="Submit Button" OnClientClick="TestSubmit();" OnClick="_Submit_Click" />

Javascript Client Side Function:

function TestSubmit() {
              try {

             var message = "Message to Pass";
             document.getElementById('__EVENTTARGET').value = message;

           } catch (err) {



C# Server Side Function

protected void _Submit_Click(object sender, EventArgs e)
     // Hidden Value after postback
     string hiddenVal= Request.Form["__EVENTTARGET"];

Hope this helps!

How to read file binary in C#?

Quick and dirty version:

byte[] fileBytes = File.ReadAllBytes(inputFilename);
StringBuilder sb = new StringBuilder();

foreach(byte b in fileBytes)
    sb.Append(Convert.ToString(b, 2).PadLeft(8, '0'));  

File.WriteAllText(outputFilename, sb.ToString());

Continuous CSS rotation animation on hover, animated back to 0deg on hover out

It took a few tries, but I was able to get your jsFiddle to work (for Webkit only).

There's still an issue with the animation speed when the user re-enters the div.

Basically, just set the current rotation value to a variable, then do some calculations on that value (to convert to degrees), then set that value back to the element on mouse move and mouse enter.

Check out the jsFiddle:

Check out this article for more information, including how to add cross-browser compatibility:

Modifying the "Path to executable" of a windows service

There is also this approach seen on SuperUser which uses the sc command line instead of modifying the registry:

sc config <service name> binPath= <binary path>

Note: the space after binPath= is important. You can also query the current configuration using:

sc qc <service name>

This displays output similar to:

[SC] QueryServiceConfig SUCCESS


    TYPE               : 10  WIN32_OWN_PROCESS
    START_TYPE         : 2   AUTO_START
    BINARY_PATH_NAME   : C:\Services\ServiceName
    TAG                : 0
    DISPLAY_NAME       : <Display name>
    DEPENDENCIES       :
    SERVICE_START_NAME : user-name@domain-name

Laravel 5.4 create model, controller and migration in single artisan command

You can do it if you start from the model

php artisan make:model Todo -mcr

if you run php artisan make:model --help you can see all the available options

-m, --migration Create a new migration file for the model.
-c, --controller Create a new controller for the model.
-r, --resource Indicates if the generated controller should be a resource controller


As mentioned in the comments by @arun in newer versions of laravel > 5.6 it is possible to run following command:

php artisan make:model Todo -a

-a, --all Generate a migration, factory, and resource controller for the model

Select only rows if its value in a particular column is less than the value in the other column

df[df$aged <= df$laclen, ] 

Should do the trick. The square brackets allow you to index based on a logical expression.

How to get table cells evenly spaced?

I'm also open to suggestion on how to tidy this up, if there are any? :-)

Well, you could not use the span element, for semantic reasons. And you don't have to define the class PerformanceCell. The cells and rows can be accessed by using PerformanceTable tr {} and PerformanceTable tr {}, respectively.

For the spacing part, I have got the same problem several times. I shamefully admit I avoided the problem, so I am very curious to any answers too.

Python Finding Prime Factors

For prime number generation I always use Sieve of Eratosthenes:

def primes(n):
    if n<=2:
        return []
    for x in range(3,int(n**0.5)+1,2):
        for y in range(3,(n//x)+1,2):

    return [2]+[i for i in range(3,n,2) if sieve[i]]

In [42]: %timeit primes(10**5)
10 loops, best of 3: 60.4 ms per loop

In [43]: %timeit primes(10**6)
1 loops, best of 3: 1.01 s per loop

You can use Miller-Rabin primality test to check whether a number is prime or not. You can find its Python implementations here.

Always use timeit module to time your code, the 2nd one takes just 15us:

def func():
    n = 600851475143
    i = 2
    while i * i < n:
         while n % i == 0:
            n = n / i
         i = i + 1

In [19]: %timeit func()
1000 loops, best of 3: 1.35 ms per loop

def func():
    while i<100:i+=1

In [21]: %timeit func()
10000 loops, best of 3: 15.3 us per loop

error: pathspec 'test-branch' did not match any file(s) known to git

The modern Git should able to detect remote branches and create a local one on checkout.

However if you did a shallow clone (e.g. with --depth 1), try the following commands to correct it:

git config remote.origin.fetch '+refs/heads/*:refs/remotes/origin/*'
git fetch --all

and try to checkout out the branch again.

Alternatively try to unshallow your clone, e.g. git fetch --unshallow and try again.

See also: How to fetch all remote branches?

How can I get list of values from dict?

out: dict_values([{1:a, 2:b}])

in:  str(dict.values())[14:-3]    
out: 1:a, 2:b

Purely for visual purposes. Does not produce a useful product... Only useful if you want a long dictionary to print in a paragraph type form.

How to uninstall/upgrade Angular CLI?

Run this command

npm uninstall angular-cli

Parse time of format hh:mm:ss

String time = "12:32:22";
String[] values = time.split(":");

This will take your time and split it where it sees a colon and put the value in an array, so you should have 3 values after this.

Then loop through string array and convert each one. (with Integer.parseInt)

Correct way to integrate jQuery plugins in AngularJS

i have alreay 2 situations where directives and services/factories didnt play well.

the scenario is that i have (had) a directive that has dependency injection of a service, and from the directive i ask the service to make an ajax call (with $http).

in the end, in both cases the ng-Repeat did not file at all, even when i gave the array an initial value.

i even tried to make a directive with a controller and an isolated-scope

only when i moved everything to a controller and it worked like magic.

example about this here Initialising jQuery plugin (RoyalSlider) in Angular JS

IF EXISTS condition not working with PLSQL

Unfortunately PL/SQL doesn't have IF EXISTS operator like SQL Server. But you can do something like this:

  for x in ( select count(*) cnt
               from dual 
              where exists (
                select 1 from courseoffering co
                  join co_enrolment ce on ce.co_id = co.co_id
                 where ce.s_regno = 403 
                   and ce.coe_completionstatus = 'C' 
                   and co.c_id = 803 ) )
        if ( x.cnt = 1 ) 
           dbms_output.put_line('does not exist');
        end if;
  end loop;

git rebase merge conflict

Note: with Git 2.14.x/2.15 (Q3 2017), the git rebase message in case of conflicts will be clearer.

See commit 5fdacc1 (16 Jul 2017) by William Duclot (williamdclt).
(Merged by Junio C Hamano -- gitster -- in commit 076eeec, 11 Aug 2017)

rebase: make resolve message clearer for inexperienced users


When you have resolved this problem, run "git rebase --continue".
If you prefer to skip this patch, run "git rebase --skip" instead.
To check out the original branch and stop rebasing, run "git rebase --abort"


Resolve all conflicts manually, 
mark them as resolved with git add/rm <conflicted_files>
then run "git rebase --continue".

You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".')

The git UI can be improved by addressing the error messages to those they help: inexperienced and casual git users.
To this intent, it is helpful to make sure the terms used in those messages can be understood by this segment of users, and that they guide them to resolve the problem.

In particular, failure to apply a patch during a git rebase is a common problem that can be very destabilizing for the inexperienced user.
It is important to lead them toward the resolution of the conflict (which is a 3-steps process, thus complex) and reassure them that they can escape a situation they can't handle with "--abort".
This commit answer those two points by detailing the resolution process and by avoiding cryptic git linguo.

Bootstrap push div content to new line

Do a row div.

Like this:

<link href="" rel="stylesheet" integrity="sha384-Zug+QiDoJOrZ5t4lssLdxGhVrurbmBWopoEl+M6BdEfwnCJZtKxi1KgxUyJq13dy" crossorigin="anonymous">_x000D_
<div class="grid">_x000D_
    <div class="row">_x000D_
        <div class="col-lg-3 col-md-3 col-sm-3 col-xs-12 bg-success">Under me should be a DIV</div>_x000D_
        <div class="col-lg-6 col-md-6 col-sm-5 col-xs-12 bg-danger">Under me should be a DIV</div>_x000D_
    <div class="row">_x000D_
        <div class="col-lg-3 col-md-3 col-sm-4 col-xs-12 bg-warning">I am the last DIV</div>_x000D_

MySQL my.cnf performance tuning recommendations

Try starting with the Percona wizard and comparing their recommendations against your current settings one by one. Don't worry there aren't as many applicable settings as you might think.

Update circa 2020: Sorry, this tool reached it's end of life:

Everyone points to key_buffer_size first which you have addressed. With 96GB memory I'd be wary of any tiny default value (likely to be only 96M!).

MySQL user DB does not have password columns - Installing MySQL on OSX

remember password needs to be set further even after restarting mysql as below