Programs & Examples On #Wix extension

Extensions to the windows packaging software WiX, that's used to create msi installers.

How do I unlock a SQLite database?

I found the documentation of the various states of locking in SQLite to be very helpful. Michael, if you can perform reads but can't perform writes to the database, that means that a process has gotten a RESERVED lock on your database but hasn't executed the write yet. If you're using SQLite3, there's a new lock called PENDING where no more processes are allowed to connect but existing connections can sill perform reads, so if this is the issue you should look at that instead.

Filtering Sharepoint Lists on a "Now" or "Today"

Pass Today as value as mentioned below in $viewQuery property :

$web = Get-SPWeb "http://sitename"
$list = $web.Lists.TryGetList($listtitle)
write-host "Exporting '$($list.Title)' data from '$($web.Title)' site.."
$viewTitle = "Program Events" #Title property
#Add the column names from the ViewField property to a string collection
$viewFields = New-Object System.Collections.Specialized.StringCollection
$viewFields.Add("Event Date") > $null
$viewFields.Add("Title") > $null
#Query property
$viewQuery = "<Where><Geq><FieldRef Name='EventDate' /><Value IncludeTimeValue='TRUE' Type='DateTime'><Today/></Value></Geq></Where><OrderBy><FieldRef Name='EventDate' Ascending='True' /></OrderBy>"
#RowLimit property
$viewRowLimit = 30
#Paged property
$viewPaged = $true
#DefaultView property
$viewDefaultView = $false
#Create the view in the destination list
$newview = $list.Views.Add($viewTitle, $viewFields, $viewQuery, $viewRowLimit, $viewPaged, $viewDefaultView)
Write-Host ("View '" + $newview.Title + "' created in list '" + $list.Title + "' on site " + $web.Url)

How to show multiline text in a table cell

I use the html code tag after each line (see below) and it works for me.

George Benson </br> 123 Main Street </br> New York, Ny 12344 </br>

What are CN, OU, DC in an LDAP search?

What are CN, OU, DC?

From RFC2253 (UTF-8 String Representation of Distinguished Names):

String  X.500 AttributeType
CN      commonName
L       localityName
ST      stateOrProvinceName
O       organizationName
OU      organizationalUnitName
C       countryName
STREET  streetAddress
DC      domainComponent
UID     userid

What does the string from that query mean?

The string ("CN=Dev-India,OU=Distribution Groups,DC=gp,DC=gl,DC=google,DC=com") is a path from an hierarchical structure (DIT = Directory Information Tree) and should be read from right (root) to left (leaf).

It is a DN (Distinguished Name) (a series of comma-separated key/value pairs used to identify entries uniquely in the directory hierarchy). The DN is actually the entry's fully qualified name.

Here you can see an example where I added some more possible entries.
The actual path is represented using green.

LDAP tree

The following paths represent DNs (and their value depends on what you want to get after the query is run):

  • "DC=gp,DC=gl,DC=google,DC=com"
  • "OU=Distribution Groups,DC=gp,DC=gl,DC=google,DC=com"
  • "OU=People,DC=gp,DC=gl,DC=google,DC=com"
  • "OU=Groups,DC=gp,DC=gl,DC=google,DC=com"
  • "CN=QA-Romania,OU=Distribution Groups,DC=gp,DC=gl,DC=google,DC=com"
  • "CN=Dev-India,OU=Distribution Groups,DC=gp,DC=gl,DC=google,DC=com"
  • "CN=Diana Anton,OU=People,DC=gp,DC=gl,DC=google,DC=com"

How to show row number in Access query like ROW_NUMBER in SQL

You can try this query:

Select A.*, (select count(*) from Table1 where A.ID>=ID) as RowNo
from Table1 as A
order by A.ID

selenium - chromedriver executable needs to be in PATH

Another way is download and unzip chromedriver and put 'chromedriver.exe' in C:\Python27\Scripts and then you need not to provide the path of driver, just

driver= webdriver.Chrome()

will work

font size in html code

Don't need to quote css attributes and you should specify an unit. (You should use an external css file too..!)

Setting a Sheet and cell as variable

Yes, set the cell as a RANGE object one time and then use that RANGE object in your code:

Sub RangeExample()
Dim MyRNG As Range

Set MyRNG = Sheets("Sheet1").Cells(23, 4)

Debug.Print MyRNG.Value

End Sub

Alternately you can simply store the value of that cell in memory and reference the actual value, if that's all you really need. That variable can be Long or Double or Single if numeric, or String:

Sub ValueExample()
Dim MyVal As String

MyVal = Sheets("Sheet1").Cells(23, 4).Value

Debug.Print MyVal

End Sub

How I add Headers to http.get or in Typescript and angular 2?

Be sure to declare HttpHeaders without null values.

    this.http.get('url', {headers: new HttpHeaders({'a': a || '', 'b': b || ''}))

Otherwise, if you try to add a null value to HttpHeaders it will give you an error.

Set focus and cursor to end of text input field / string w. Jquery

You can do this using Input.setSelectionRange, part of the Range API for interacting with text selections and the text cursor:

var searchInput = $('#Search');

// Multiply by 2 to ensure the cursor always ends up at the end;
// Opera sometimes sees a carriage return as 2 characters.
var strLength = searchInput.val().length * 2;

searchInput[0].setSelectionRange(strLength, strLength);

Demo: Fiddle

What is the difference between Step Into and Step Over in a debugger

You can't go through the details of the method by using the step over. If you want to skip the current line, you can use step over, then you only need to press the F6 for only once to move to the next line. And if you think there's someting wrong within the method, use F5 to examine the details.

Jquery UI tooltip does not support html content

You can also achieve this completely without jQueryUI by using CSS styles. See the snippet below:

div#Tooltip_Text_container {_x000D_
  max-width: 25em;_x000D_
  height: auto;_x000D_
  display: inline;_x000D_
  position: relative;_x000D_
div#Tooltip_Text_container a {_x000D_
  text-decoration: none;_x000D_
  color: black;_x000D_
  cursor: default;_x000D_
  font-weight: normal;_x000D_
div#Tooltip_Text_container a span.tooltips {_x000D_
  visibility: hidden;_x000D_
  opacity: 0;_x000D_
  transition: visibility 0s linear 0.2s, opacity 0.2s linear;_x000D_
  position: absolute;_x000D_
  left: 10px;_x000D_
  top: 18px;_x000D_
  width: 30em;_x000D_
  border: 1px solid #404040;_x000D_
  padding: 0.2em 0.5em;_x000D_
  cursor: default;_x000D_
  line-height: 140%;_x000D_
  font-size: 12px;_x000D_
  font-family: 'Segoe UI';_x000D_
  -moz-border-radius: 3px;_x000D_
  -webkit-border-radius: 3px;_x000D_
  border-radius: 3px;_x000D_
  -moz-box-shadow: 7px 7px 5px -5px #666;_x000D_
  -webkit-box-shadow: 7px 7px 5px -5px #666;_x000D_
  box-shadow: 7px 7px 5px -5px #666;_x000D_
  background: #E4E5F0  repeat-x;_x000D_
div#Tooltip_Text_container:hover a span.tooltips {_x000D_
  visibility: visible;_x000D_
  opacity: 1;_x000D_
  transition-delay: 0.2s;_x000D_
div#Tooltip_Text_container img {_x000D_
  left: -10px;_x000D_
div#Tooltip_Text_container:hover a span.tooltips {_x000D_
  visibility: visible;_x000D_
  opacity: 1;_x000D_
  transition-delay: 0.2s;_x000D_
<div id="Tooltip_Text_container">_x000D_
  <span><b>Tooltip headline</b></span>_x000D_
  <a href="#">_x000D_
    <span class="tooltips">_x000D_
        <b>This is&nbsp;</b> a tooltip<br/>_x000D_
        <b>This is&nbsp;</b> another tooltip<br/>_x000D_
  <br/>Move the mousepointer to the tooltip headline above. _x000D_

The first span is for the displayed text, the second span for the hidden text, which is shown when you hover over it.

What is MVC and what are the advantages of it?

MVC is just a general design pattern that, in the context of lean web app development, makes it easy for the developer to keep the HTML markup in an app’s presentation layer (the view) separate from the methods that receive and handle client requests (the controllers) and the data representations that are returned within the view (the models). It’s all about separation of concerns, that is, keeping code that serves one functional purpose (e.g. handling client requests) sequestered from code that serves an entirely different functional purpose (e.g. representing data).

It’s the same principle for why anybody who’s spent more than 5 min trying to build a website can appreciate the need to keep your HTML markup, JavaScript, and CSS in separate files: If you just dump all of your code into a single file, you end up with spaghetti that’s virtually un-editable later on.

Since you asked for possible "cons": I’m no authority on software architecture design, but based on my experience developing in MVC, I think it’s also important to point out that following a strict, no-frills MVC design pattern is most useful for 1) lightweight web apps, or 2) as the UI layer of a larger enterprise app. I’m surprised this specification isn’t talked about more, because MVC contains no explicit definitions for your business logic, domain models, or really anything in the data access layer of your app. When I started developing in ASP.NET MVC (i.e. before I knew other software architectures even existed), I would end up with very bloated controllers or even view models chock full of business logic that, had I been working on enterprise applications, would have made it difficult for other devs who were unfamiliar with my code to modify (i.e. more spaghetti).

Status bar and navigation bar appear over my view's bounds in iOS 7

Swift Solution:

override func viewWillAppear(animated: Bool) {
    self.edgesForExtendedLayout = UIRectEdge.None

Convert JSON array to Python list

data will return you a string representation of a list, but it is actually still a string. Just check the type of data with type(data). That means if you try using indexing on this string representation of a list as such data['fruits'][0], it will return you "[" as it is the first character of data['fruits']

You can do json.loads(data['fruits']) to convert it back to a Python list so that you can interact with regular list indexing. There are 2 other ways you can convert it back to a Python list suggested here

How to make button fill table cell

For starters:

<p align='center'>
<table width='100%'>
<td align='center'><form><input type=submit value="click me" style="width:100%"></form></td>

Note, if the width of the input button is 100%, you wont need the attribute "align='center'" anymore.

This would be the optimal solution:

<p align='center'>
<table width='100%'>
<td><form><input type=submit value="click me" style="width:100%"></form></td>

Using MySQL with Entity Framework

Be careful using connector .net, Connector 6.6.5 have a bug, it is not working for inserting tinyint values as identity, for example:

create table person(
    Id tinyint unsigned primary key auto_increment,
    Name varchar(30)

if you try to insert an object like this:

Person p;
p = new Person();
p.Name = 'Oware'

You will get a Null Reference Exception:

Referencia a objeto no establecida como instancia de un objeto.:
   en MySql.Data.Entity.ListFragment.WriteSql(StringBuilder sql)
   en MySql.Data.Entity.SelectStatement.WriteSql(StringBuilder sql)
   en MySql.Data.Entity.InsertStatement.WriteSql(StringBuilder sql)
   en MySql.Data.Entity.SqlFragment.ToString()
   en MySql.Data.Entity.InsertGenerator.GenerateSQL(DbCommandTree tree)
   en MySql.Data.MySqlClient.MySqlProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree)
   en System.Data.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree commandTree)
   en System.Data.Common.DbProviderServices.CreateCommand(DbCommandTree commandTree)
   en System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree)
   en System.Data.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(UpdateTranslator translator, Dictionary`2 identifierValues)
   en System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator translator, EntityConnection connection, Dictionary`2 identifierValues, List`1 generatedValues)
   en System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
   en System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache)
   en System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options)
   en System.Data.Entity.Internal.InternalContext.SaveChanges()
   en System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
   en System.Data.Entity.DbContext.SaveChanges()

Until now I haven't found a solution, I had to change my tinyint identity to unsigned int identity, this solved the problem but this is not the right solution.

If you use an older version of (I used 6.4.4) you won't have this problem.

If someone knows about the solution, please contact me.



@Autowired - No qualifying bean of type found for dependency

I ran in to this recently, and as it turned out, I've imported the wrong annotation in my service class. Netbeans has an option to hide import statements, that's why I did not see it for some time.

I've used @org.jvnet.hk2.annotations.Service instead of @org.springframework.stereotype.Service.

Can someone explain how to implement the jQuery File Upload plugin?

I've just spent 2 hours battling with jQuery Upload but gave up because of the amount of dependencies (I had 13 JS files included to get all the bells and whistles).

I did a bit more searching and came across a neat project called Dropzone.js, which does not have any dependencies.

The author has also created a bootstrap demo which was inspired by the jQuery File Upload plugin.

I hope this saves someone else some time.

How to retrieve images from MySQL database and display in an html tag

You need to retrieve and disect the information into what you need.

while($row = mysql_fetch_array($result)) {
 echo "img src='",$row['filename'],"' width='175' height='200' />";

How to delete multiple values from a vector?

First we can define a new operator,

"%ni%" = Negate( "%in%" )

Then, its like x not in remove

x <- 1:10
remove <- c(2,3,5)
x <- x[ x %ni% remove ]

or why to go for remove, go directly

x <- x[ x %ni% c(2,3,5)]

Is it possible to convert char[] to char* in C?

It sounds like you're confused between pointers and arrays. Pointers and arrays (in this case char * and char []) are not the same thing.

  • An array char a[SIZE] says that the value at the location of a is an array of length SIZE
  • A pointer char *a; says that the value at the location of a is a pointer to a char. This can be combined with pointer arithmetic to behave like an array (eg, a[10] is 10 entries past wherever a points)

In memory, it looks like this (example taken from the FAQ):

 char a[] = "hello";  // array

a: | h | e | l | l | o |\0 |

 char *p = "world"; // pointer

   +-----+     +---+---+---+---+---+---+
p: |  *======> | w | o | r | l | d |\0 |
   +-----+     +---+---+---+---+---+---+

It's easy to be confused about the difference between pointers and arrays, because in many cases, an array reference "decays" to a pointer to it's first element. This means that in many cases (such as when passed to a function call) arrays become pointers. If you'd like to know more, this section of the C FAQ describes the differences in detail.

One major practical difference is that the compiler knows how long an array is. Using the examples above:

char a[] = "hello";  
char *p =  "world";  

sizeof(a); // 6 - one byte for each character in the string,
           // one for the '\0' terminator
sizeof(p); // whatever the size of the pointer is
           // probably 4 or 8 on most machines (depending on whether it's a 
           // 32 or 64 bit machine)

Without seeing your code, it's hard to recommend the best course of action, but I suspect changing to use pointers everywhere will solve the problems you're currently having. Take note that now:

  • You will need to initialise memory wherever the arrays used to be. Eg, char a[10]; will become char *a = malloc(10 * sizeof(char));, followed by a check that a != NULL. Note that you don't actually need to say sizeof(char) in this case, because sizeof(char) is defined to be 1. I left it in for completeness.

  • Anywhere you previously had sizeof(a) for array length will need to be replaced by the length of the memory you allocated (if you're using strings, you could use strlen(), which counts up to the '\0').

  • You will need a make a corresponding call to free() for each call to malloc(). This tells the computer you are done using the memory you asked for with malloc(). If your pointer is a, just write free(a); at a point in the code where you know you no longer need whatever a points to.

As another answer pointed out, if you want to get the address of the start of an array, you can use:

char* p = &a[0] 

You can read this as "char pointer p becomes the address of element [0] of a".

Docker official registry (Docker Hub) URL

For those wanting to explicitly declare they are pulling from dockerhub when using fabric8 maven plugin, add a new property: <docker.pull.registry></docker.pull.registry>

I arrived on this page trying to solve problem of pulling from my AWS ECR registry when building Docker images using fabric8.

Is it possible to access an SQLite database from JavaScript?

You could use SQL.js which is the SQLlite lib compiled to JavaScript and store the database in the local storage introduced in HTML5.

Change language for bootstrap DateTimePicker

all you are right! other way to getting !

You can find out all languages on there

How to check if any value is NaN in a Pandas DataFrame

Since pandas has to find this out for DataFrame.dropna(), I took a look to see how they implement it and discovered that they made use of DataFrame.count(), which counts all non-null values in the DataFrame. Cf. pandas source code. I haven't benchmarked this technique, but I figure the authors of the library are likely to have made a wise choice for how to do it.

Why do symbols like apostrophes and hyphens get replaced with black diamonds on my website?

I experienced the same problem when I copied a text that has an apostrophe from a Word document to my HTML code.

To resolve the issue, all I did was deleted the particular word in my HTML and typed it directly, including the apostrophe. This action nullified the original copy and paste acton and displayed the newly typed apostrophe correctly

LINQ to Entities does not recognize the method

As you've figured out, Entity Framework can't actually run your C# code as part of its query. It has to be able to convert the query to an actual SQL statement. In order for that to work, you will have to restructure your query expression into an expression that Entity Framework can handle.

public System.Linq.Expressions.Expression<Func<Charity, bool>> IsSatisfied()
    string name = this.charityName;
    string referenceNumber = this.referenceNumber;
    return p => 
        (string.IsNullOrEmpty(name) || 
            p.registeredName.ToLower().Contains(name.ToLower()) ||
            p.alias.ToLower().Contains(name.ToLower()) ||
            p.charityId.ToLower().Contains(name.ToLower())) &&
        (string.IsNullOrEmpty(referenceNumber) ||

How to delete an object by id with entity framework

A smaller version (when compared to previous ones):

var customer = context.Find(id);

How to delete multiple pandas (python) dataframes from memory to save RAM?

del statement does not delete an instance, it merely deletes a name.

When you do del i, you are deleting just the name i - but the instance is still bound to some other name, so it won't be Garbage-Collected.

If you want to release memory, your dataframes has to be Garbage-Collected, i.e. delete all references to them.

If you created your dateframes dynamically to list, then removing that list will trigger Garbage Collection.

>>> lst = [pd.DataFrame(), pd.DataFrame(), pd.DataFrame()]
>>> del lst     # memory is released

If you created some variables, you have to delete them all.

>>> a, b, c = pd.DataFrame(), pd.DataFrame(), pd.DataFrame()
>>> lst = [a, b, c]
>>> del a, b, c # dfs still in list
>>> del lst     # memory release now

AngularJS ng-class if-else expression

Use it this way:

    <div [ngClass]="{cssClass A: condition 1, cssClass B: condition 2, cssClass C: condition 3}">...</div>

Escape quotes in JavaScript

This is how I do it, basically str.replace(/[\""]/g, '\\"').

var display = document.getElementById('output');_x000D_
var str = 'class="whatever-foo__input" id="node-key"';_x000D_
display.innerHTML = str.replace(/[\""]/g, '\\"');_x000D_
//will return class=\"whatever-foo__input\" id=\"node-key\"
<span id="output"></span>

Why am I getting a "401 Unauthorized" error in Maven?

I had the same error. I tried and rechecked everything. I was so focused in the Stack trace that I didn't read the last lines of the build before the Reactor summary and the stack trace:

[DEBUG] Using connector AetherRepositoryConnector with priority 3.4028235E38 for http://www:8081/nexus/content/repositories/snapshots/
[INFO] Downloading: http://www:8081/nexus/content/repositories/snapshots/com/wdsuite/com.wdsuite.server.product/1.0.0-SNAPSHOT/maven-metadata.xml
[DEBUG] Could not find metadata in nexus (http://www:8081/nexus/content/repositories/snapshots/)
[DEBUG] Writing tracking file /home/me/.m2/repository/com/group/project/version-SNAPSHOT/
[INFO] Uploading: http://www:8081/nexus/content/repositories/snapshots/com/
[INFO] Uploading: http://www:8081/nexus/content/repositories/snapshots/com/...-1.0.0-20141118.124526-1.pom
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:

This was the key : "Could not find metadata". Although it said that it was an authentication error actually it got fixed doing a "rebuild metadata" in the nexus repository.

Hope it helps.

Setting table row height

If you are using Bootstrap, look at padding of your tds.

How to remove \xa0 from string in Python?

I ran into this same problem pulling some data from a sqlite3 database with python. The above answers didn't work for me (not sure why), but this did: line = line.decode('ascii', 'ignore') However, my goal was deleting the \xa0s, rather than replacing them with spaces.

I got this from this super-helpful unicode tutorial by Ned Batchelder.

Using OR operator in a jquery if statement

Think about what

if ((state != 10) || (state != 15) || (state != 19) || (state != 22) || (state != 33) || (state != 39) || (state != 47) || (state != 48) || (state != 49) || (state != 51))

means. || means "or." The negation of this is (by DeMorgan's Laws):

state == 10 && state == 15 && state == 19...

In other words, the only way that this could be false if if a state equals 10, 15, and 19 (and the rest of the numbers in your or statement) at the same time, which is impossible.

Thus, this statement will always be true. State 15 will never equal state 10, for example, so it's always true that state will either not equal 10 or not equal 15.

Change || to &&.

Also, in most languages, the following:

if (x) {
  return true;
else {
  return false;

is not necessary. In this case, the method returns true exactly when x is true and false exactly when x is false. You can just do:

return x;

List of special characters for SQL LIKE clause

Potential answer for SQL Server

Interesting I just ran a test using LinqPad with SQL Server which should be just running Linq to SQL underneath and it generates the following SQL statement.

Records .Where(r => r.Name.Contains("lkjwer--_~[]"))

-- Region Parameters
DECLARE @p0 VarChar(1000) = '%lkjwer--~_~~~[]%'
-- EndRegion
SELECT [t0].[ID], [t0].[Name]
WHERE [t0].[Name] LIKE @p0 ESCAPE '~'

So I haven't tested it yet but it looks like potentially the ESCAPE '~' keyword may allow for automatic escaping of a string for use within a like expression.

Storing money in a decimal column - what precision and scale?

If you were using IBM Informix Dynamic Server, you would have a MONEY type which is a minor variant on the DECIMAL or NUMERIC type. It is always a fixed-point type (whereas DECIMAL can be a floating point type). You can specify a scale from 1 to 32, and a precision from 0 to 32 (defaulting to a scale of 16 and a precision of 2). So, depending on what you need to store, you might use DECIMAL(16,2) - still big enough to hold the US Federal Deficit, to the nearest cent - or you might use a smaller range, or more decimal places.

How to edit default.aspx on SharePoint site without SharePoint Designer

I was able to accomplish editing the default.aspx page by:

  • Opening the site in SharePoint Designer 2013
  • Then clicking 'All Files' to view all of the files,
  • Then right-click -> Edit file in Advanced Mode.

By doing that I was able to remove the tagprefix causing a problem on my page.

How to handle a lost KeyStore password in Android?

Just encountered this problem myself - luckily I was able to find the password in some Gradle's temporary file. Just in case anyone lands here:

try looking for this file




and search for


It was there in cleartext. In general, if you do remember at least a part of your password, try searching for a file containing this substring and hopefully you will fish out something.

Wanted to throw it out here, maybe it will eventually help someone.

Edit: Added new insight from comments, just to be more visible. Edit 2: Added some more locations reported in comments.

Thanks to Vivek Bansal, Amar Ilindra and Uzbekjon for these.

Vim and Ctags tips and tricks

I've found the taglist plug-in a must-have. It lists all tags that it knows about (files that you have opened) in a seperate window and makes it very easy to navigate larger files.

I use it mostly for Python development, but it can only be better for C/C++.

Warning: #1265 Data truncated for column 'pdd' at row 1

You are most likely pushing a string 'NULL' to the table, rather then an actual NULL, but other things may be going on as well, an illustration:

mysql> CREATE TABLE date_test (pdd DATE NOT NULL);
Query OK, 0 rows affected (0.11 sec)

mysql> INSERT INTO date_test VALUES (NULL);
ERROR 1048 (23000): Column 'pdd' cannot be null
mysql> INSERT INTO date_test VALUES ('NULL');
Query OK, 1 row affected, 1 warning (0.05 sec)

mysql> show warnings;
| Level   | Code | Message                                  |
| Warning | 1265 | Data truncated for column 'pdd' at row 1 |
1 row in set (0.00 sec)

mysql> SELECT * FROM date_test;
| pdd        |
| 0000-00-00 |
1 row in set (0.00 sec)

Query OK, 1 row affected (0.15 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> INSERT INTO date_test VALUES (NULL);
Query OK, 1 row affected (0.06 sec)

mysql> SELECT * FROM date_test;
| pdd        |
| 0000-00-00 |
| NULL       |
2 rows in set (0.00 sec)

C++, copy set to vector

You haven't reserved enough space in your vector object to hold the contents of your set.

std::vector<double> output(input.size());
std::copy(input.begin(), input.end(), output.begin());

pass array to method Java

In this way we can pass an array to a function, here this print function will print the contents of the array.

public class PassArrayToFunc {

    public static void print(char [] arr) {
        for(int i = 0 ; i<arr.length;i++) {

    public static void main(String[] args) {
        Scanner scan = new Scanner(;
        char [] array =;


Mocha / Chai not catching thrown errors

examples from doc... ;)

because you rely on this context:

  • which is lost when the function is invoked by .throw
  • there’s no way for it to know what this is supposed to be

you have to use one of these options:

  • wrap the method or function call inside of another function
  • bind the context

    // wrap the method or function call inside of another function
    expect(function () { cat.meow(); }).to.throw();  // Function expression
    expect(() => cat.meow()).to.throw();             // ES6 arrow function
    // bind the context
    expect(cat.meow.bind(cat)).to.throw();           // Bind

Creating a Shopping Cart using only HTML/JavaScript

I think it is a better idea to start working with a raw data and then translate it to DOM (document object model)

I would suggest you to work with array of objects and then output it to the DOM in order to accomplish your task.

You can see working example of following code at

You can try following approach:

//create array that will hold all ordered products
    var shoppingCart = [];

    //this function manipulates DOM and displays content of our shopping cart
    function displayShoppingCart(){
        var orderedProductsTblBody=document.getElementById("orderedProductsTblBody");
        //ensure we delete all previously added rows from ordered products table
        while(orderedProductsTblBody.rows.length>0) {

        //variable to hold total price of shopping cart
        var cart_total_price=0;
        //iterate over array of objects
        for(var product in shoppingCart){
            //add new row      
            var row=orderedProductsTblBody.insertRow();
            //create three cells for product properties 
            var cellName = row.insertCell(0);
            var cellDescription = row.insertCell(1);
            var cellPrice = row.insertCell(2);
            //fill cells with values from current product object of our array
            cellName.innerHTML = shoppingCart[product].Name;
            cellDescription.innerHTML = shoppingCart[product].Description;
            cellPrice.innerHTML = shoppingCart[product].Price;
        //fill total cost of our shopping cart 

    function AddtoCart(name,description,price){
       //Below we create JavaScript Object that will hold three properties you have mentioned:    Name,Description and Price
       var singleProduct = {};
       //Fill the product object with data
       //Add newly created product to our shopping cart 
       //call display function to show on screen


    //Add some products to our shopping cart via code or you can create a button with onclick event
    //AddtoCart("Table","Big red table",50);
    //AddtoCart("Door","Big yellow door",150);
    //AddtoCart("Car","Ferrari S23",150000);

<table cellpadding="4" cellspacing="4" border="1">
        <td valign="top">
            <table cellpadding="4" cellspacing="4" border="0">
                        <td colspan="2">
                            Products for sale
                            <input type="button" value="Add to cart" onclick="AddtoCart('Table','Big red table',50)"/>
                            <input type="button" value="Add to cart" onclick="AddtoCart('Door','Yellow Door',150)"/>
                            <input type="button" value="Add to cart" onclick="AddtoCart('Ferrari','Ferrari S234',150000)"/>

        <td valign="top">
            <table cellpadding="4" cellspacing="4" border="1" id="orderedProductsTbl">
                <tbody id="orderedProductsTblBody">

                        <td colspan="3" align="right" id="cart_total">


Please have a look at following free client-side shopping cart:

SoftEcart(js) is a Responsive, Handlebars & JSON based, E-Commerce shopping cart written in JavaScript with built-in PayPal integration.


Hope you will find it useful.

How to Maximize a firefox browser window using Selenium WebDriver with node.js

One way, everyone already have written in thier answers:


but if you looking for alternative ways, here you are:




Is there a way to call a stored procedure with Dapper?

In the simple case you can do:

var user = cnn.Query<User>("spGetUser", new {Id = 1}, 
        commandType: CommandType.StoredProcedure).First();

If you want something more fancy, you can do:

 var p = new DynamicParameters();
 p.Add("@a", 11);
 p.Add("@b", dbType: DbType.Int32, direction: ParameterDirection.Output);
 p.Add("@c", dbType: DbType.Int32, direction: ParameterDirection.ReturnValue);

 cnn.Execute("spMagicProc", p, commandType: CommandType.StoredProcedure); 

 int b = p.Get<int>("@b");
 int c = p.Get<int>("@c"); 

Additionally you can use exec in a batch, but that is more clunky.

How to convert an address into a Google Maps Link (NOT MAP)<?php echo urlencode($address); ?> 

the encode ur conver and adds all the extra elements like for spaces and all. so u can easily fetch plane text code from db and use it without worring about the special characters to be added

Local variable referenced before assignment?

Put a global statement at the top of your function and you should be good:

def onLoadFinished(result):
    global feed

To demonstrate what I mean, look at this little test:

x = 0
def t():
    x += 1

this blows up with your exact same error where as:

x = 0
def t():
    global x
    x += 1

does not.

The reason for this is that, inside t, Python thinks that x is a local variable. Furthermore, unless you explicitly tell it that x is global, it will try to use a local variable named x in x += 1. But, since there is no x defined in the local scope of t, it throws an error.

How do I prevent a Gateway Timeout with FastCGI on Nginx

For those using nginx with unicorn and rails, most likely the timeout is in your unicorn.rb file

put a large timeout in unicorn.rb

timeout 500

if you're still facing issues, try having fail_timeout=0 in your upstream in nginx and see if this fixes your issue. This is for debugging purposes and might be dangerous in a production environment.

upstream foo_server {
        server fail_timeout=0;

Error type 3 Error: Activity class {} does not exist

For Android 9 devices : if your app is not installed at device already : 1) build apk 2) move apk to device and install it 3) return to Android Studio and press Run - it will launch app

Ansible: how to get output to display

Every Ansible task when run can save its results into a variable. To do this, you have to specify which variable to save the results into. Do this with the register parameter, independently of the module used.

Once you save the results to a variable you can use it later in any of the subsequent tasks. So for example if you want to get the standard output of a specific task you can write the following:

- hosts: localhost
    - shell: ls
      register: shell_result

    - debug:
        var: shell_result.stdout_lines

Here register tells ansible to save the response of the module into the shell_result variable, and then we use the debug module to print the variable out.

An example run would look like the this:

PLAY [localhost] ***************************************************************

TASK [command] *****************************************************************
changed: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "shell_result.stdout_lines": [

Responses can contain multiple fields. stdout_lines is one of the default fields you can expect from a module's response.

Not all fields are available from all modules, for example for a module which doesn't return anything to the standard out you wouldn't expect anything in the stdout or stdout_lines values, however the msg field might be filled in this case. Also there are some modules where you might find something in a non-standard variable, for these you can try to consult the module's documentation for these non-standard return values.

Alternatively you can increase the verbosity level of ansible-playbook. You can choose between different verbosity levels: -v, -vvv and -vvvv. For example when running the playbook with verbosity (-vvv) you get this:

PLAY [localhost] ***************************************************************

TASK [command] *****************************************************************
changed: [localhost] => {
    "changed": true,
    "cmd": "ls",
    "delta": "0:00:00.007621",
    "end": "2017-02-17 23:04:41.912570",
    "invocation": {
        "module_args": {
            "_raw_params": "ls",
            "_uses_shell": true,
            "chdir": null,
            "creates": null,
            "executable": null,
            "removes": null,
            "warn": true
        "module_name": "command"
    "rc": 0,
    "start": "2017-02-17 23:04:41.904949",
    "stderr": "",
    "stdout": "play.retry\nplay.yml",
    "stdout_lines": [
    "warnings": []

As you can see this will print out the response of each of the modules, and all of the fields available. You can see that the stdout_lines is available, and its contents are what we expect.

To answer your main question about the jenkins_script module, if you check its documentation, you can see that it returns the output in the output field, so you might want to try the following:

  - jenkins_script:
      script: (...)
    register: jenkins_result

  - debug:
      var: jenkins_result.output

Bootstrap fixed header and footer with scrolling body-content area in fluid-container

Until I get a better option, this is the most "bootstrappy" answer I can work out:


I have switched to using LESS and including the Bootstrap Source NuGet package to ensure compatibility (by giving me access to the bootstrap variables.less file:

in _layout.cshtml master page

  • Move footer outside the body-content container
  • Use boostrap's navbar-fixed-bottom on the footer
  • Drop the <hr/> before the footer (as now redundant)

Relevant page HTML:

<div class="container-fluid body-content">
<footer class="navbar-fixed-bottom">
    <p>&copy; @DateTime.Now.Year - My ASP.NET Application</p>

In Site.less

  • Set HTML and BODY heights to 100%
  • Set BODY overflow to hidden
  • Set body-content div position to absolute
  • Set body-content div top to @navbar-height instead of hard-wiring value
  • Set body-content div bottom to 30px.
  • Set body-content div left and right to 0
  • Set body-content div overflow-y to auto


html {
    height: 100%;

    body {
        height: 100%;
        overflow: hidden;

        .container-fluid.body-content {
            position: absolute;
            top: @navbar-height;
            bottom: 30px;
            right: 0;
            left: 0;
            overflow-y: auto;

The remaining problem is there seems to be no defining variable for the footer height in bootstrap. If someone call tell me if there is a magic 30px variable defined in Bootstrap I would appreciate it.

Print a string as hex bytes?

Just for convenience, very simple.

def hexlify_byteString(byteString, delim="%"):
    ''' very simple way to hexlify a bytestring using delimiters '''
    retval = ""
    for intval in byteString:
        retval += ( '0123456789ABCDEF'[int(intval / 16)])
        retval += ( '0123456789ABCDEF'[int(intval % 16)])
        retval += delim
    return( retval[:-1])

hexlify_byteString(b'Hello World!', ":")
# Out[439]: '48:65:6C:6C:6F:20:57:6F:72:6C:64:21'

Change Active Menu Item on Page Scroll?

Just to complement @Marcus Ekwall 's answer. Doing like this will get only anchor links. And you aren't going to have problems if you have a mix of anchor links and regular ones.

jQuery(document).ready(function(jQuery) {            
            var topMenu = jQuery("#top-menu"),
                offset = 40,
                topMenuHeight = topMenu.outerHeight()+offset,
                // All list items
                menuItems =  topMenu.find('a[href*="#"]'),
                // Anchors corresponding to menu items
                scrollItems ={
                  var href = jQuery(this).attr("href"),
                  id = href.substring(href.indexOf('#')),
                  item = jQuery(id);
                  if (item.length) { return item; }

            // so we can get a fancy scroll animation
              var href = jQuery(this).attr("href"),
                id = href.substring(href.indexOf('#'));
                  offsetTop = href === "#" ? 0 : jQuery(id).offset().top-topMenuHeight+1;
              jQuery('html, body').stop().animate({ 
                  scrollTop: offsetTop
              }, 300);

            // Bind to scroll
               // Get container scroll position
               var fromTop = jQuery(this).scrollTop()+topMenuHeight;

               // Get id of current scroll item
               var cur ={
                 if (jQuery(this).offset().top < fromTop)
                   return this;

               // Get the id of the current element
               cur = cur[cur.length-1];
               var id = cur && cur.length ? cur[0].id : "";               



Basically i replaced

menuItems = topMenu.find("a"),


menuItems =  topMenu.find('a[href*="#"]'),

To match all links with anchor somewhere, and changed all that what was necessary to make it work with this

See it in action on jsfiddle

How to move child element from one parent to another using jQuery

Based on the answers provided, I decided to make a quick plugin to do this:

    $.fn.moveTo = function(selector){
        return this.each(function(){
            var cl = $(this).clone();



Difference between pre-increment and post-increment in a loop?

Since you ask about the difference in a loop, i guess you mean

for(int i=0; i<10; i++) 

In that case, you have no difference in most languages: The loop behaves the same regardless of whether you write i++ and ++i. In C++, you can write your own versions of the ++ operators, and you can define separate meanings for them, if the i is of a user defined type (your own class, for example).

The reason why it doesn't matter above is because you don't use the value of i++. Another thing is when you do

for(int i=0, a = 0; i<10; a = i++) 

Now, there is a difference, because as others point out, i++ means increment, but evaluate to the previous value, but ++i means increment, but evaluate to i (thus it would evaluate to the new value). In the above case, a is assigned the previous value of i, while i is incremented.

MySQL: How to reset or change the MySQL root password?

For Ubuntu 18.04 and mysql version 14.14 Distrib 5.7.22 follow the below step to reset the mysql password.

Step 1

sudo systemctl stop mysql

Step 2

sudo systemctl edit mysql

This command will open a new file in the nano editor, which you'll use to edit MySQL's service overrides. These change the default service parameters for MySQL. This file will be empty, so add the following content:

ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/ --skip-grant-tables --skip-networking

Step 3

sudo systemctl daemon-reload
sudo systemctl start mysql

Step 4

sudo mysql -u root

Step 5


Step 6

UPDATE mysql.user SET authentication_string = PASSWORD('new_password') WHEREuser = 'root';

Step 7

UPDATE mysql.user SET plugin ='mysql_native_password' WHERE user = 'root';

Step 8

sudo systemctl revert mysql

and finally

sudo systemctl restart mysql

Now enjoy

How do you determine the ideal buffer size when using FileInputStream?

You could use the BufferedStreams/readers and then use their buffer sizes.

I believe the BufferedXStreams are using 8192 as the buffer size, but like Ovidiu said, you should probably run a test on a whole bunch of options. Its really going to depend on the filesystem and disk configurations as to what the best sizes are.

Size of character ('a') in C/C++

In C, the type of a character constant like 'a' is actually an int, with size of 4 (or some other implementation-dependent value). In C++, the type is char, with size of 1. This is one of many small differences between the two languages.

How to do paging in AngularJS?

I use this 3rd party pagination library and it works well. It can do local/remote datasources and it's very configurable.


"for line in..." results in UnicodeDecodeError: 'utf-8' codec can't decode byte

If you are using Python 2, the following will be the solution:

import io
for line in"u.item", encoding="ISO-8859-1"):
    # Do something

Because the encoding parameter doesn't work with open(), you will be getting the following error:

TypeError: 'encoding' is an invalid keyword argument for this function

How to make div background color transparent in CSS

The problem with opacity is that it will also affect the content, when often you do not want this to happen.

If you just want your element to be transparent, it's really as easy as :

background-color: transparent;

But if you want it to be in colors, you can use:

background-color: rgba(255, 0, 0, 0.4);

Or define a background image (1px by 1px) saved with the right alpha.
(To do so, use Gimp, Paint.Net or any other image software that allows you to do that.
Just create a new image, delete the background and put a semi-transparent color in it, then save it in png.)

As said by René, the best thing to do would be to mix both, with the rgba first and the 1px by 1px image as a fallback if the browser doesn't support alpha :

background: url('img/red_transparent_background.png');
background: rgba(255, 0, 0, 0.4);

See also :

Demo : My JSFiddle

How to set caret(cursor) position in contenteditable element (div)?

I'm writting a syntax highlighter (and basic code editor), and I needed to know how to auto-type a single quote char and move the caret back (like a lot of code editors nowadays).

Heres a snippet of my solution, thanks to much help from this thread, the MDN docs, and a lot of moz console watching..

//onKeyPress event

if (evt.key === "\"") {
    let sel = window.getSelection();
    let offset = sel.focusOffset;
    let focus = sel.focusNode;

    focus.textContent += "\""; //setting div's innerText directly creates new
    //nodes, which invalidate our selections, so we modify the focusNode directly

    let range = document.createRange();
    range.setStart(focus, offset);


//end onKeyPress event

This is in a contenteditable div element

I leave this here as a thanks, realizing there is already an accepted answer.

Find something in column A then show the value of B for that row in Excel 2010


source data range is A1:B100.
query cell is D1 (here you will input Police or Fire).
result cell is E1

Formula in E1 = VLOOKUP(D1, A1:B100, 2, FALSE)

Closing Applications

for me best solotion this is


and force close app.

How to pass a value to razor variable from javascript variable?

But it would be possible if one were used in place of the variable in @html.Hidden field. As in this example.

@Html.Hidden("myVar", 0);

set the field per script:

function setMyValue(value) {

I hope I can at least offer no small Workaround.

Threading pool similar to the multiprocessing Pool?

If you don't mind executing other's code, here's mine:

Note: There is lot of extra code you may want to remove [added for better clarificaiton and demonstration how it works]

Note: Python naming conventions were used for method names and variable names instead of camelCase.

Working procedure:

  1. MultiThread class will initiate with no of instances of threads by sharing lock, work queue, exit flag and results.
  2. SingleThread will be started by MultiThread once it creates all instances.
  3. We can add works using MultiThread (It will take care of locking).
  4. SingleThreads will process work queue using a lock in middle.
  5. Once your work is done, you can destroy all threads with shared boolean value.
  6. Here, work can be anything. It can automatically import (uncomment import line) and process module using given arguments.
  7. Results will be added to results and we can get using get_results


import threading
import queue

class SingleThread(threading.Thread):
    def __init__(self, name, work_queue, lock, exit_flag, results):
        threading.Thread.__init__(self) = name
        self.work_queue = work_queue
        self.lock = lock
        self.exit_flag = exit_flag
        self.results = results

    def run(self):
        # print("Coming %s with parameters %s",, self.exit_flag)
        while not self.exit_flag:
            # print(self.exit_flag)
            if not self.work_queue.empty():
                work = self.work_queue.get()
                module, operation, args, kwargs = work.module, work.operation, work.args, work.kwargs
                print("Processing : " + operation + " with parameters " + str(args) + " and " + str(kwargs) + " by " + + "\n")
                # module = __import__(module_name)
                result = str(getattr(module, operation)(*args, **kwargs))
                print("Result : " + result + " for operation " + operation + " and input " + str(args) + " " + str(kwargs))
        # process_work_queue(self.work_queue)

class MultiThread:
    def __init__(self, no_of_threads):
        self.exit_flag = bool_instance()
        self.queue_lock = threading.Lock()
        self.threads = []
        self.work_queue = queue.Queue()
        self.results = []
        for index in range(0, no_of_threads):
            thread = SingleThread("Thread" + str(index+1), self.work_queue, self.queue_lock, self.exit_flag, self.results)

    def add_work(self, work):

    def destroy(self):
        self.exit_flag.value = True
        for thread in self.threads:

    def get_results(self):
        return self.results

class Work:
    def __init__(self, module, operation, args, kwargs={}):
        self.module = module
        self.operation = operation
        self.args = args
        self.kwargs = kwargs

class SimpleOperations:
    def sum(self, *args):
        return sum([int(arg) for arg in args])

    def mul(a, b, c=0):
        return int(a) * int(b) + int(c)

class bool_instance:
    def __init__(self, value=False):
        self.value = value

    def __setattr__(self, key, value):
        if key != "value":
            raise AttributeError("Only value can be set!")
        if not isinstance(value, bool):
            raise AttributeError("Only True/False can be set!")
        self.__dict__[key] = value
        # super.__setattr__(key, bool(value))

    def __bool__(self):
        return self.value

if __name__ == "__main__":
    multi_thread = MultiThread(5)
    multi_thread.add_work(Work(SimpleOperations(), "mul", [2, 3], {"c":4}))
    while True:
        data_input = input()
        if data_input == "":
        elif data_input == "break":
            work = data_input.split()
            multi_thread.add_work(Work(SimpleOperations(), work[0], work[1:], {}))

Compile a DLL in C/C++, then call it from another program

For VB6:

You need to declare your C functions as __stdcall, otherwise you get "invalid calling convention" type errors. About other your questions:

can I take arguments by pointer/reference from the VB front-end?

Yes, use ByRef/ByVal modifiers.

Can the DLL call a theoretical function in the front-end?

Yes, use AddressOf statement. You need to pass function pointer to dll before.

Or have a function take a "function pointer" (I don't even know if that's possible) from VB and call it?)

Yes, use AddressOf statement.

update (more questions appeared :)):

to load it into VB, do I just do the usual method (what I would do to load winsock.ocx or some other runtime, but find my DLL instead) or do I put an API call into a module?

You need to decaler API function in VB6 code, like next:

Private Declare Function SHGetSpecialFolderLocation Lib "shell32" _
   (ByVal hwndOwner As Long, _
    ByVal nFolder As Long, _
    ByRef pidl As Long) As Long

Remove header and footer from window.print()

Today my colleague stumbled upon the same issue.

As the "margin:0" solution works for chromium based browsers, however, Internet Explorer continue to print footer even if @page margins are set to zero.

The solution (more of a hack) was to put negative margin on the @page.

@page {margin:0 -6cm}
html {margin:0 6cm}

Please note that negative margin won't work for Y axis, only for X

Hope it helps.

How can I convert a PFX certificate file for use with Apache on a linux server?

Took some tooling around but this is what I ended up with.

Generated and installed a certificate on IIS7. Exported as PFX from IIS

Convert to pkcs12

openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes

NOTE: While converting PFX to PEM format, openssl will put all the Certificates and Private Key into a single file. You will need to open the file in Text editor and copy each Certificate & Private key(including the BEGIN/END statements) to its own individual text file and save them as certificate.cer, CAcert.cer, privateKey.key respectively.

Saved as certificate.key

Saved as certificate.crt

Added to apache vhost w/ Webmin.

Is there a way to make text unselectable on an HTML page?

Here's a Sass mixin (scss) for those interested. Compass/CSS 3 doesn't seem to have a user-select mixin.

// @usage use within a rule
// ex. img {@include user-select(none);}
// @param assumed valid user-select value
@mixin user-select($value)
    & {
        -webkit-touch-callout: $value;
        -webkit-user-select: $value;
        -khtml-user-select: $value;
        -moz-user-select: $value;
        -ms-user-select: $value;
        user-select: $value;

Though Compass would do it in a more robust way, i.e. only add support for vendors you've chosen.

how to display excel sheet in html page

If you are making a link <a href='file.htm'>link name</a> or place an iframe tag, it will show the excel data on web but you can't make changes to it.

Every time you make changes in the Excel sheet you have to save again with the same name so it will replace file, and will show the result. The <a> tag file name extension should be .htm

What's the difference between Git Revert, Checkout and Reset?

Reset - On the commit-level, resetting is a way to move the tip of a branch to a different commit. This can be used to remove commits from the current branch.

Revert - Reverting undoes a commit by creating a new commit. This is a safe way to undo changes, as it has no chance of re-writing the commit history. Contrast this with git reset, which does alter the existing commit history. For this reason, git revert should be used to undo changes on a public branch, and git reset should be reserved for undoing changes on a private branch.

You can have a look on this link- Reset, Checkout and Revert

Oracle SQL Developer: Failure - Test failed: The Network Adapter could not establish the connection?

This worked for me. may help some one. Turn off firewall. on RHEL 7

systemctl stop  firewalld

Android: why setVisibility(View.GONE); or setVisibility(View.INVISIBLE); do not work

In my case I found that simply clearing the animation on the view before setting the visibility to GONE works.


I had a similar issue where I toggle between two views, one of which must always start off as GONE - But when I displayed the views again, it was displaying over the first view even if setVisibility(GONE) was called. Clearing the animation before setting the view to GONE worked.

Regular expression that matches valid IPv6 addresses

This catches the loopback(::1) as well and ipv6 addresses. changed {} to + and put : inside the first square bracket.


tested on with ifconfig -a output

Unix or Mac OSx terminal o option returns only the matching output(ipv6) including ::1

ifconfig -a | egrep -o '([a-f0-9:]+:+)+[a-f0-9]+'

Get All IP addresses (IPv4 OR IPv6) and print match on unix OSx term

ifconfig -a | egrep -o '([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}) | (([a-f0-9:]+:+)+[a-f0-9]+)'

iOS Remote Debugging

Note: I have no affiliation with Ghostlab creators Vanamco whatsoever.

It was important to me to be able to debug Chrome-specific problems, so I set out to find something that could help me with that. I ended up happily throwing my money at Ghostlab 3. I can test Chrome and Safari mobile browsers as if I was viewing them on my desktop. It just gives me a LAN address to use for any device I’d like to debug. Each application using that address will appear in the list in Ghostlab.

enter image description here

enter image description here

Highly recommended.

How to push to History in React Router v4?

/*Step 1*/
myFunction(){  this.props.history.push("/home"); }
 <button onClick={()=>this.myFunction()} className={'btn btn-primary'}>Go 

C# DataRow Empty-check

A simple method along the lines of:

bool AreAllColumnsEmpty(DataRow dr)
 if (dr == null)
  return true;
  foreach(var value in dr.ItemArray)
    if (value != null)
      return false;
  return true;

Should give you what you're after, and to make it "nice" (as there's nothing as far as I'm aware, in the Framework), you could wrap it up as an extension method, and then your resultant code would be:

if (datarow.AreAllColumnsEmpty())

How can I perform a str_replace in JavaScript, replacing text in JavaScript?

If you really want a equivalent to PHP's str_replace you can use Locutus. PHP's version of str_replace support more option then what the JavaScript String.prototype.replace supports. For example tags:

$bodytag = str_replace("%body%", "black", "<body text='%body%'>");
//JS with Locutus
var $bodytag = str_replace(['{body}', 'black', '<body text='{body}'>')  

or array's

$vowels = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U");
$onlyconsonants = str_replace($vowels, "", "Hello World of PHP");
//JS with Locutus
var $vowels = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"];
var $onlyconsonants = str_replace($vowels, "", "Hello World of PHP");

Also this doesn't use regex instead it uses for loops. If you not want to use regex but want simple string replace you can use something like this ( based on Locutus )

function str_replace (search, replace, subject) {_x000D_
  var i = 0_x000D_
  var j = 0_x000D_
  var temp = ''_x000D_
  var repl = ''_x000D_
  var sl = 0_x000D_
  var fl = 0_x000D_
  var f = [].concat(search)_x000D_
  var r = [].concat(replace)_x000D_
  var s = subject_x000D_
  s = [].concat(s)_x000D_
  for (i = 0, sl = s.length; i < sl; i++) {_x000D_
    if (s[i] === '') {_x000D_
    for (j = 0, fl = f.length; j < fl; j++) {_x000D_
      temp = s[i] + ''_x000D_
      repl = r[0]_x000D_
      s[i] = (temp).split(f[j]).join(repl)_x000D_
      if (typeof countObj !== 'undefined') {_x000D_
        countObj.value += ((temp.split(f[j])).length - 1)_x000D_
  return s[0]_x000D_
var text = "this is some sample text that i want to replace";_x000D_
var new_text = str_replace ("want", "dont want", text)_x000D_

for more info see the source code

Input type "number" won't resize

Incorrect usage.

Input type number it's made to have selectable value via arrows up and down.

So basically you are looking for "width" CSS style.

Input text historically is formatted with monospaced font, so size it's also the width it takes.

Input number it's new and "size" property has no sense at all*. A typical usage:

<input type="number" name="quantity" min="1" max="5">

w3c docs

to fix, add a style:

<input type="number" name="email" style="width: 7em">

EDIT: if you want a range, you have to set type="range" and not ="number"

EDIT2: *size is not an allowed value (so, no sense). Check out official W3C specifications

Note: The size attribute works with the following input types: text, search, tel, url, email, and password.

Tip: To specify the maximum number of characters allowed in the element, use the maxlength attribute.

Get all dates between two dates in SQL Server

My first suggestion would be use your calendar table, if you don't have one, then create one. They are very useful. Your query is then as simple as:

DECLARE @MinDate DATE = '20140101',
        @MaxDate DATE = '20140106';

FROM    dbo.Calendar
WHERE   Date >= @MinDate
AND     Date < @MaxDate;

If you don't want to, or can't create a calendar table you can still do this on the fly without a recursive CTE:

DECLARE @MinDate DATE = '20140101',
        @MaxDate DATE = '20140106';

SELECT  TOP (DATEDIFF(DAY, @MinDate, @MaxDate) + 1)
        Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, @MinDate)
FROM    sys.all_objects a
        CROSS JOIN sys.all_objects b;

For further reading on this see:

With regard to then using this sequence of dates in a cursor, I would really recommend you find another way. There is usually a set based alternative that will perform much better.

So with your data:

  date   | it_cd | qty 
24-04-14 |  i-1  | 10 
26-04-14 |  i-1  | 20

To get the quantity on 28-04-2014 (which I gather is your requirement), you don't actually need any of the above, you can simply use:

SELECT  TOP 1 date, it_cd, qty 
WHERE   it_cd = 'i-1'
AND     Date <= '20140428'

If you don't want it for a particular item:

SELECT  date, it_cd, qty 
FROM    (   SELECT  date, 
                    RowNumber = ROW_NUMBER() OVER(PARTITION BY ic_id 
                                                    ORDER BY date DESC)
            FROM    T
            WHERE   Date  <= '20140428'
        ) T
WHERE   RowNumber = 1;

How to get JSON response from http.Get

Your Problem were the slice declarations in your data structs (except for Track, they shouldn't be slices...). This was compounded by some rather goofy fieldnames in the fetched json file, which can be fixed via structtags, see godoc.

The code below parsed the json successfully. If you've further questions, let me know.

package main

import "fmt"
import "net/http"
import "io/ioutil"
import "encoding/json"

type Tracks struct {
    Toptracks Toptracks_info

type Toptracks_info struct {
    Track []Track_info
    Attr  Attr_info `json: "@attr"`

type Track_info struct {
    Name       string
    Duration   string
    Listeners  string
    Mbid       string
    Url        string
    Streamable Streamable_info
    Artist     Artist_info   
    Attr       Track_attr_info `json: "@attr"`

type Attr_info struct {
    Country    string
    Page       string
    PerPage    string
    TotalPages string
    Total      string

type Streamable_info struct {
    Text      string `json: "#text"`
    Fulltrack string

type Artist_info struct {
    Name string
    Mbid string
    Url  string

type Track_attr_info struct {
    Rank string

func perror(err error) {
    if err != nil {

func get_content() {
    url := ""

    res, err := http.Get(url)
    defer res.Body.Close()

    decoder := json.NewDecoder(res.Body)
    var data Tracks
    err = decoder.Decode(&data)
    if err != nil {
        fmt.Printf("%T\n%s\n%#v\n",err, err, err)
        switch v := err.(type){
            case *json.SyntaxError:
    for i, track := range data.Toptracks.Track{
        fmt.Printf("%d: %s %s\n", i, track.Artist.Name, track.Name)

func main() {

How to change color in circular progress bar?

To customize circular ProgressBar we need to create a indeterminateDrawable to show custom progress bar

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


            android:width="48dip" />

            android:useLevel="false" />



We need to include drawable in progressbar just as below:

    android:layout_height="wrap_content" />

DeprecationWarning: Buffer() is deprecated due to security and usability issues when I move my script to another server

The use of the deprecated new Buffer() constructor (i.E. as used by Yarn) can cause deprecation warnings. Therefore one should NOT use the deprecated/unsafe Buffer constructor.

According to the deprecation warning new Buffer() should be replaced with one of:

  • Buffer.alloc()
  • Buffer.allocUnsafe() or
  • Buffer.from()

Another option in order to avoid this issue would be using the safe-buffer package instead.

You can also try (when using yarn..):

yarn global add yarn

as mentioned here: Link

Another suggestion from the comments (thx to gkiely): self-update

Note: self-update is not available. See policies for enforcing versions within a project

In order to update your version of Yarn, run

curl --compressed -o- -L | bash

How to get object length

For those coming here to find the item count of something that is already a jQuery object:
.length is what you are looking for:


len = $('#divID').length;

CodeIgniter query: How to move a column value to another column in the same row and save the current time in the original column?

$data = array( 
    'name'      => $_POST['name'] , 
    'groupname' => $_POST['groupname'], 
    'age'       => $_POST['age']

$this->db->where('id', $_POST['id']);

$this->db->update('tbl_user', $data);

How to change the size of the radio button using CSS?

Not directly. In fact, form elements in general are either problematic or impossible to style using CSS alone. the best approach is to:

  1. hide the radio button using javascript.
  2. Use javascript to add/display HTML that can be styled how you like e.g.
  3. Define css rules for a selected state, which is triggered by adding a class "selected" to yuor span.
  4. Finally, write javascript to make the radio button's state react to clicks on the span, and, vice versa, to get the span to react to changes in the radio button's state (for when users use the keyboard to access the form). the second part of this can be tricky to get to work across all browsers. I use something like the following (which also uses jQuery. I avoid adding extra spans too by styling and applying the "selected" class directly to the input labels).


var labels = $("ul.radioButtons).delegate("input", "keyup", function () { //keyboard use
        if (this.checked) {
    }).find("label").bind("click", function (event) { //mouse use

function select(el) {


<ul class="radioButtons">
        <label for="employee1">
            <input type="radio" id="employee1" name="employee" />
        <label for="employee2">
            <input type="radio" id="employee2" name="employee" />

Split string with PowerShell and do something with each token

-split outputs an array, and you can save it to a variable like this:

$a = -split 'Once  upon    a     time'


Another cute thing, you can have arrays on both sides of an assignment statement:

$a,$b,$c = -split 'Once  upon    a'


What exceptions should be thrown for invalid or unexpected parameters in .NET?

I like to use: ArgumentException, ArgumentNullException, and ArgumentOutOfRangeException.

There are other options, too, that do not focus so much on the argument itself, but rather judge the call as a whole:

  • InvalidOperationException – The argument might be OK, but not in the current state of the object. Credit goes to STW (previously Yoooder). Vote his answer up as well.
  • NotSupportedException – The arguments passed in are valid, but just not supported in this implementation. Imagine an FTP client, and you pass a command in that the client doesn’t support.

The trick is to throw the exception that best expresses why the method cannot be called the way it is. Ideally, the exception should be detailed about what went wrong, why it is wrong, and how to fix it.

I love when error messages point to help, documentation, or other resources. For example, Microsoft did a good first step with their KB articles, e.g. “Why do I receive an "Operation aborted" error message when I visit a Web page in Internet Explorer?”. When you encounter the error, they point you to the KB article in the error message. What they don’t do well is that they don’t tell you, why specifically it failed.

Thanks to STW (ex Yoooder) again for the comments.

In response to your followup, I would throw an ArgumentOutOfRangeException. Look at what MSDN says about this exception:

ArgumentOutOfRangeException is thrown when a method is invoked and at least one of the arguments passed to the method is not null reference (Nothing in Visual Basic) and does not contain a valid value.

So, in this case, you are passing a value, but that is not a valid value, since your range is 1–12. However, the way you document it makes it clear, what your API throws. Because although I might say ArgumentOutOfRangeException, another developer might say ArgumentException. Make it easy and document the behavior.

How to find the first and second maximum number?

If you want the second highest number you can use


although that doesn't account for duplicates so you could get the same result as the Max

If you want the largest number that is smaller than the maximum number you can use this version


Send form data with jquery ajax json

The accepted answer here indeed makes a json from a form, but the json contents is really a string with url-encoded contents.

To make a more realistic json POST, use some solution from Serialize form data to JSON to make formToJson function and add contentType: 'application/json;charset=UTF-8' to the jQuery ajax call parameters.

    url: 'test.php',
    type: "POST",
    dataType: 'json',
    data: formToJson($("form")),
    contentType: 'application/json;charset=UTF-8',

Composer: file_put_contents(./composer.json): failed to open stream: Permission denied

In my case I don't have issues with ~/.composer.
So being inside Laravel app root folder, I did sudo chown -R $USER composer.lock and it was helpful.

The transaction log for the database is full

Try this:

If possible restart the services MSSQLSERVER and SQLSERVERAGENT.

Origin http://localhost is not allowed by Access-Control-Allow-Origin

This approach resolved my issue to allow multiple domain

app.use(function(req, res, next) {
      var allowedOrigins = ['', 'http://localhost:8020', '', 'http://localhost:9000'];
      var origin = req.headers.origin;
      if(allowedOrigins.indexOf(origin) > -1){
           res.setHeader('Access-Control-Allow-Origin', origin);
      //res.header('Access-Control-Allow-Origin', '');
      res.header('Access-Control-Allow-Methods', 'GET, OPTIONS');
      res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');
      res.header('Access-Control-Allow-Credentials', true);
      return next();

In .NET, which loop runs faster, 'for' or 'foreach'?

It seems a bit strange to totally forbid the use of something like a for loop.

There's an interesting article here that covers a lot of the performance differences between the two loops.

I would say personally I find foreach a bit more readable over for loops but you should use the best for the job at hand and not have to write extra long code to include a foreach loop if a for loop is more appropriate.

Sample database for exercise

This is what I am using for learning sql: employees-db

this is a sample database with an integrated test suite, used to test your applications and database servers

3rd party edit

According to the database has moved to github.

The database contains about 300,000 employee records with 2.8 million salary entries. The export data is 167 MB, which is not huge, but heavy enough to be non-trivial for testing.

The data was generated, and as such there are inconsistencies and subtle problems. Rather than removing them, we decided to leave the contents untouched, and use these issues as data cleaning exercises.

Maven build debug in Eclipse

probleme : unit test result are not the same runing with eclipse and maven due ti order of library used by eclipse and maven. In my case the test was success with maven but i want to debug my unit test using eclipse, so the most easy way to debug unit test class with eclipse and runing maven is :

1) mvn -Dtest=MySuperClassTest -Dmaven.surefire.debug test ==> it will listen to the 5005 port (default port)

2) Go to eclipse, open a debug configuration, add a new java remote application and change the port to 5005 and debug

3) of course you must add break point somewhere in the class that you want to debug

jQuery $.ajax(), pass success data into separate function

I believe your problem is that you are passing testFunct a string, and not a function object, (is that even possible?)

To add server using sp_addlinkedserver

Add the linked server first with

exec sp_addlinkedserver


AttributeError: Can only use .dt accessor with datetimelike values

When you write

df['Date'] = pd.to_datetime(df['Date'], errors='coerce')
df['Date'] = df['Date'].dt.strftime('%m/%d')

It can fixed

Pipenv: Command Not Found

If you've done a user installation, you'll need to add the right folder to your PATH variable.

PYTHON_BIN_PATH="$(python3 -m site --user-base)/bin"

See pipenv's installation instructions

error_log per Virtual Host?

I usually just specify this in an .htaccess file or the vhost.conf on the domain I'm working on. Add this to one of these files:

php_admin_value error_log "/var/www/vhosts/"

How to resize a VirtualBox vmdk file

Download/Install/Use VMWare Workstation and create new VM Based on your current vmdk file and then you can resize your vmdk. For details regarding this matter google for VMWare.

How to Update Date and Time of Raspberry Pi With out Internet

You will need to configure your Win7 PC as a Time Server, and then configure the RasPi to connect to it for NTP services.

Configure Win7 as authoritative time server. Configure RasPi time server lookup.

Java array assignment (multiple values)

If you know the values at compile time you can do :

float[] values = {0.1f, 0.2f, 0.3f};

There is no way to do that if values are variables in runtime.

Time complexity of nested for-loop

First we'll consider loops where the number of iterations of the inner loop is independent of the value of the outer loop's index. For example:

 for (i = 0; i < N; i++) {
     for (j = 0; j < M; j++) {
         sequence of statements

The outer loop executes N times. Every time the outer loop executes, the inner loop executes M times. As a result, the statements in the inner loop execute a total of N * M times. Thus, the total complexity for the two loops is O(N2).

Char array in a struct - incompatible assignment?

Or you could just use dynamic allocation, e.g.:

struct name {
  char *first;
  char *last;

struct name sara;
sara.first = "Sara";
sara.last = "Black";
printf("first: %s, last: %s\n", sara.first, sara.last);

Slidedown and slideup layout with animation

I use these easy functions, it work like jquery slideUp slideDown, use it in an helper class, just pass your view :

public static void expand(final View v) {
    v.measure(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.WRAP_CONTENT);
    final int targetHeight = v.getMeasuredHeight();

    // Older versions of android (pre API 21) cancel animations for views with a height of 0.
    v.getLayoutParams().height = 1;
    Animation a = new Animation()
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            v.getLayoutParams().height = interpolatedTime == 1
                    ? WindowManager.LayoutParams.WRAP_CONTENT
                    : (int)(targetHeight * interpolatedTime);

        public boolean willChangeBounds() {
            return true;

    // 1dp/ms
    a.setDuration((int) (targetHeight / v.getContext().getResources().getDisplayMetrics().density));

public static void collapse(final View v) {
    final int initialHeight = v.getMeasuredHeight();

    Animation a = new Animation()
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            if(interpolatedTime == 1){
                v.getLayoutParams().height = initialHeight - (int)(initialHeight * interpolatedTime);

        public boolean willChangeBounds() {
            return true;

    // 1dp/ms
    a.setDuration((int)(initialHeight / v.getContext().getResources().getDisplayMetrics().density));

MySql ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

In my case, I needed to Edit Inbound Rules on my AWS RDS instance to accept All Traffic. The default TCP/IP constraint prevented me from creating a database from my local machine otherwise.

Convert String to Uri

What are you going to do with the URI?

If you're just going to use it with an HttpGet for example, you can just use the string directly when creating the HttpGet instance.

HttpGet get = new HttpGet("");

Passing two command parameters using a WPF binding

This task can also be solved with a different approach. Instead of programming a converter and enlarging the code in the XAML, you can also aggregate the various parameters in the ViewModel. As a result, the ViewModel then has one more property that contains all parameters.

An example of my current application, which also let me deal with the topic. A generic RelayCommand is required:

The ViewModelBase is extended here by a command SaveAndClose. The generic type is a named tuple that represents the various parameters.

public ICommand SaveAndCloseCommand => saveAndCloseCommand ??= new RelayCommand<(IBaseModel Item, Window Window)>
    (execute =>
        execute.Window?.Close(); // if NULL it isn't closed.
    canExecute =>
        return canExecute.Item?.IsItemValide ?? false;
private ICommand saveAndCloseCommand;

Then it contains a property according to the generic type:

public (IBaseModel Item, Window Window) SaveAndCloseParameter 
    get => saveAndCloseParameter ; 
        SetProperty(ref saveAndCloseParameter, value);
private (IBaseModel Item, Window Window) saveAndCloseParameter;

The XAML code of the view then looks like this: (Pay attention to the classic click event)

    Command="{Binding SaveAndCloseCommand}" 
    CommandParameter="{Binding SaveAndCloseParameter}" 
    Height="25" Width="100" />
    Command="{Binding SaveAndCloseCommand}" 
    CommandParameter="{Binding SaveAndCloseParameter}" 
    Height="25" Width="100" />

and in the code behind of the view, then evaluating the click events, which then set the parameter property.

private void ButtonApply_Click(object sender, RoutedEventArgs e)
    computerViewModel.SaveAndCloseParameter = (computerViewModel.Computer, null);

private void ButtonSave_Click(object sender, RoutedEventArgs e)
    computerViewModel.SaveAndCloseParameter = (computerViewModel.Computer, this);

Personally, I think that using the click events is not a break with the MVVM pattern. The program flow control is still located in the area of ??the ViewModel.

Why is a primary-foreign key relation required when we can join without it?

I know its late to post, but I use the site for my own reference and so I wanted to put an answer here for myself to reference in the future too. I hope you (and others) find it helpful.

Lets pretend a bunch of super Einstein experts designed our database. Our super perfect database has 3 tables, and the following relationships defined between them:

TblA 1:M TblB
TblB 1:M TblC

Notice there is no relationship between TblA and TblC

In most scenarios such a simple database is easy to navigate but in commercial databases it is usually impossible to be able to tell at the design stage all the possible uses and combination of uses for data, tables, and even whole databases, especially as systems get built upon and other systems get integrated or switched around or out. This simple fact has spawned a whole industry built on top of databases called Business Intelligence. But I digress...

In the above case, the structure is so simple to understand that its easy to see you can join from TblA, through to B, and through to C and vice versa to get at what you need. It also very vaguely highlights some of the problems with doing it. Now expand this simple chain to 10 or 20 or 50 relationships long. Now all of a sudden you start to envision a need for exactly your scenario. In simple terms, a join from A to C or vice versa or A to F or B to Z or whatever as our system grows.

There are many ways this can indeed be done. The one mentioned above being the most popular, that is driving through all the links. The major problem is that its very slow. And gets progressively slower the more tables you add to the chain, the more those tables grow, and the further you want to go through it.

Solution 1: Look for a common link. It must be there if you taught of a reason to join A to C. If it is not obvious, create a relationship and then join on it. i.e. To join A through B through C there must be some commonality or your join would either produce zero results or a massive number or results (Cartesian product). If you know this commonality, simply add the needed columns to A and C and link them directly.

The rule for relationships is that they simply must have a reason to exist. Nothing more. If you can find a good reason to link from A to C then do it. But you must ensure your reason is not redundant (i.e. its already handled in some other way).

Now a word of warning. There are some pitfalls. But I don't do a good job of explaining them so I will refer you to my source instead of talking about it here. But remember, this is getting into some heavy stuff, so this video about fan and chasm traps is really only a starting point. You can join without relationships. But I advise watching this video first as this goes beyond what most people learn in college and well into the territory of the BI and SAP guys. These guys, while they can program, their day job is to specialise in exactly this kind of thing. How to get massive amounts of data to talk to each other and make sense.

This video is one of the better videos I have come across on the subject. And it's worth looking over some of his other videos. I learned a lot from him.

How to use pip on windows behind an authenticating proxy

It took me a couple hours to figure this out but I finally got it to work using CNTLM and afterwards got it to work with just a pip config file. Here is how I got it work with the pip config file...


1. In Windows navigate to your user profile directory (Ex. C:\Users\Sync) and create a folder named "pip"

2. Create a file named "pip.ini" in this directory (Ex. C:\Users\Sync\pip\pip.ini) and enter the following into it:

    trusted-host =
    proxy = http://[domain name]%5C[username]:[password]@[proxy address]:[proxy port]

Replace [domain name], [username], [password], [proxy address] and [proxy port] with your own information.

Note, if your [domain name], [username] or [password] has special characters, you have to percent-encode | encode them.

3. At this point I was able to run "pip install" without any issues.

Hopefully this works for others too!

P.S.: This may pose a security concern because of having your password stored in plain text. If this is an issue, consider setting up CNTLM using this article (allows using hashed password instead of plain text). Afterwards set proxy = the "pip.ini" file mentioned above.

How to Get XML Node from XDocument

The .Elements operation returns a LIST of XElements - but what you really want is a SINGLE element. Add this:

XElement Contacts = (from xml2 in XMLDoc.Elements("Contacts").Elements("Node")
                    where xml2.Element("ID").Value == variable
                    select xml2).FirstOrDefault();

This way, you tell LINQ to give you the first (or NULL, if none are there) from that LIST of XElements you're selecting.


How to run crontab job every week on Sunday

10 * * * Sun

Position 1 for minutes, allowed values are 1-60
position 2 for hours, allowed values are 1-24
position 3 for day of month ,allowed values are 1-31
position 4 for month ,allowed values are 1-12 
position 5 for day of week ,allowed values are 1-7 or and the day starts at Monday. 

SQL: sum 3 columns when one column has a null value?

If the column has a 0 value, you are fine, my guess is that you have a problem with a Null value, in that case you would need to use IsNull(Column, 0) to ensure it is always 0 at minimum.

Reading data from a website using C#

 WebClient client = new WebClient();
            using (Stream data = client.OpenRead(Text))
                using (StreamReader reader = new StreamReader(data))
                    string content = reader.ReadToEnd();
                    string pattern = @"((https?|ftp|gopher|telnet|file|notes|ms-help):((//)|(\\\\))+[\w\d:#@%/;$()~_?\+-=\\\.&]*)";
                    MatchCollection matches = Regex.Matches(content,pattern);
                    List<string> urls = new List<string>();
                    foreach (Match match in matches)


Replace String in all files in Eclipse

  • "Search"->"File"
  • Enter text, file pattern and projects
  • "Replace"
  • Enter new text


jQuery equivalent of JavaScript's addEventListener method

$( "button" ).on( "click", function(event) {_x000D_
    alert( $( this ).html() );_x000D_
    console.log( );_x000D_
} );
<script src=""></script>_x000D_
<button>test 1</button>_x000D_
<button>test 2</button>

SQL like search string starts with

SELECT * from games WHERE (lower(title) LIKE 'age of empires III');

The above query doesn't return any rows because you're looking for 'age of empires III' exact string which doesn't exists in any rows.

So in order to match with this string with different string which has 'age of empires' as substring you need to use '%your string goes here%'

More on mysql string comparision

You need to try this

SELECT * from games WHERE (lower(title) LIKE '%age of empires III%');

In Like '%age of empires III%' this will search for any matching substring in your rows, and it will show in results.

How do I install a pip package globally instead of locally?

I actually don‘t see your issue. Globally is any package which is in your python3 path‘s site package folder.

If you want to use it just locally then you must configure a virtualenv and reinstall the packages with an activated virtual environment.

How to simulate target="_blank" in JavaScript

I know this is a done and sorted out deal, but here's what I'm using to solve the problem in my app.

if (!"target")) {
    e.preventDefault();"target", "_blank");;

Basically what is going on here is I run a check for if the link has target=_blank attribute. If it doesn't, it stops the link from triggering, sets it up to open in a new window then programmatically clicks on it.

You can go one step further and skip the stopping of the original click (and make your code a whole lot more compact) by trying this:

if (!"target")) {"target", "_blank");

If you were using jQuery to abstract away the implementation of adding an attribute cross-browser, you should use this instead of"target", "_blank"):

    jQuery("target", "_blank")

You may need to rework it to fit your exact use-case, but here's how I scratched my own itch.

Here's a demo of it in action for you to mess with.

(The link in jsfiddle comes back to this discussion .. no need a new tab :))

Why do I get "'property cannot be assigned" when sending an SMTP email?

MailMessage mm = new MailMessage(txtEmail.Text, txtTo.Text);
mm.Subject = txtSubject.Text;
mm.Body = txtBody.Text;
if (fuAttachment.HasFile)//file upload select or not
    string FileName = Path.GetFileName(fuAttachment.PostedFile.FileName);
    mm.Attachments.Add(new Attachment(fuAttachment.PostedFile.InputStream, FileName));
mm.IsBodyHtml = false;
SmtpClient smtp = new SmtpClient();
smtp.Host = "";
smtp.EnableSsl = true;
NetworkCredential NetworkCred = new NetworkCredential(txtEmail.Text, txtPassword.Text);
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
Response.write("Send Mail");

View Video:

Setting ANDROID_HOME enviromental variable on Mac OS X

I am having MAC OS X(Sierra) 10.12.2.

I set ANDROID_HOME to work on React Native(for Android apps) by following the following steps.

  • Open Terminal (press Command+SpaceBar, type Terminal, Hit ENTER).

  • Add the following 3 lines to ~/.bash_profile.

      export ANDROID_HOME=$HOME/Library/Android/sdk/
      export PATH=$PATH:$ANDROID_HOME/tools
      export PATH=$PATH:$ANDROID_HOME/platform-tools
  • Finally execute the below command (or RESTART the system to reflect the changes made).

    source ~/.bash_profile

That's it.

Today's Date in Perl in MM/DD/YYYY format

use Time::Piece;
my $t = localtime;
print $t->mdy("/");# 02/29/2000

Are static class variables possible in Python?

Static methods in python are called classmethods. Take a look at the following code

class MyClass:

    def myInstanceMethod(self):
        print 'output from an instance method'

    def myStaticMethod(cls):
        print 'output from a static method'

>>> MyClass.myInstanceMethod()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unbound method myInstanceMethod() must be called [...]

>>> MyClass.myStaticMethod()
output from a static method

Notice that when we call the method myInstanceMethod, we get an error. This is because it requires that method be called on an instance of this class. The method myStaticMethod is set as a classmethod using the decorator @classmethod.

Just for kicks and giggles, we could call myInstanceMethod on the class by passing in an instance of the class, like so:

>>> MyClass.myInstanceMethod(MyClass())
output from an instance method

Select distinct values from a table field

By example:

# select distinct code from Platform where id in ( select platform__id from Build where product=p)
pl_ids = Build.objects.values('platform__id').filter(product=p)
platforms = Platform.objects.values_list('code', flat=True).filter(id__in=pl_ids).distinct('code')
platforms = list(platforms) if platforms else []

How to jump to a particular line in a huge text file?

If you don't want to read the entire file in memory .. you may need to come up with some format other than plain text.

of course it all depends on what you're trying to do, and how often you will jump across the file.

For instance, if you're gonna be jumping to lines many times in the same file, and you know that the file does not change while working with it, you can do this:
First, pass through the whole file, and record the "seek-location" of some key-line-numbers (such as, ever 1000 lines),
Then if you want line 12005, jump to the position of 12000 (which you've recorded) then read 5 lines and you'll know you're in line 12005 and so on

How to support placeholder attribute in IE8 and 9

For others landing here. This is what worked for me:

//jquery polyfill for showing place holders in IE9
$('[placeholder]').focus(function() {
    var input = $(this);
    if (input.val() == input.attr('placeholder')) {
}).blur(function() {
    var input = $(this);
    if (input.val() == '' || input.val() == input.attr('placeholder')) {

$('[placeholder]').parents('form').submit(function() {
    $(this).find('[placeholder]').each(function() {
        var input = $(this);
        if (input.val() == input.attr('placeholder')) {

Just add this in you script.js file. Courtesy of

No Title Bar Android Theme

Why are you changing android os inbuilt theme.

As per your activity Require You have to implements this way


as per @arianoo says you have to used this feature.

I think this is better way to hide titlebar theme.

What's NSLocalizedString equivalent in Swift?

Swift 3 version :)...

import Foundation

extension String {
    var localized: String {
        return NSLocalizedString(self, tableName: nil, bundle: Bundle.main, value: "", comment: "")

@Autowired - No qualifying bean of type found for dependency at least 1 bean

Guys I found the issue

I just tried by adding the qualifier name in employee service finally it solved my issue.


public class EmployeeServiceImpl implements EmployeeService{


How do I enumerate the properties of a JavaScript object?

In modern browsers (ECMAScript 5) to get all enumerable properties you can do:

Object.keys(obj) (Check the link to get a snippet for backward compatibility on older browsers)

Or to get also non-enumerable properties:


Check ECMAScript 5 compatibility table

Additional info: What is a enumerable attribute?

How to set a background image in Xcode using swift?

override func viewDidLoad() {
    self.view.backgroundColor = UIColor(patternImage: UIImage(named: "background.png"))

How to remove &quot; from my Json in javascript?

Accepted answer is right, however I had a trouble with that. When I add in my code, checking on debugger, I saw that it changes from




Instead of this I use that:


By this notation it works.

Matrix multiplication using arrays

Java. Matrix multiplication.

Tested with matrices of different size.

public class Matrix {

 * Matrix multiplication method.
 * @param m1 Multiplicand
 * @param m2 Multiplier
 * @return Product
    public static double[][] multiplyByMatrix(double[][] m1, double[][] m2) {
        int m1ColLength = m1[0].length; // m1 columns length
        int m2RowLength = m2.length;    // m2 rows length
        if(m1ColLength != m2RowLength) return null; // matrix multiplication is not possible
        int mRRowLength = m1.length;    // m result rows length
        int mRColLength = m2[0].length; // m result columns length
        double[][] mResult = new double[mRRowLength][mRColLength];
        for(int i = 0; i < mRRowLength; i++) {         // rows from m1
            for(int j = 0; j < mRColLength; j++) {     // columns from m2
                for(int k = 0; k < m1ColLength; k++) { // columns from m1
                    mResult[i][j] += m1[i][k] * m2[k][j];
        return mResult;

    public static String toString(double[][] m) {
        String result = "";
        for(int i = 0; i < m.length; i++) {
            for(int j = 0; j < m[i].length; j++) {
                result += String.format("%11.2f", m[i][j]);
            result += "\n";
        return result;

    public static void main(String[] args) {
        // #1
        double[][] multiplicand = new double[][] {
                {3, -1, 2},
                {2,  0, 1},
                {1,  2, 1}
        double[][] multiplier = new double[][] {
                {2, -1, 1},
                {0, -2, 3},
                {3,  0, 1}
        System.out.println("#1\n" + toString(multiplyByMatrix(multiplicand, multiplier)));
        // #2
        multiplicand = new double[][] {
                {1, 2, 0},
                {-1, 3, 1},
                {2, -2, 1}
        multiplier = new double[][] {
        System.out.println("#2\n" + toString(multiplyByMatrix(multiplicand, multiplier)));
        // #3
        multiplicand = new double[][] {
                {1, 2, -1},
                {0,  1, 0}
        multiplier = new double[][] {
                {1, 1, 0, 0},
                {0, 2, 1, 1},
                {1, 1, 2, 2}
        System.out.println("#3\n" + toString(multiplyByMatrix(multiplicand, multiplier)));


      12.00      -1.00       2.00
       7.00      -2.00       3.00
       5.00      -5.00       8.00


       0.00       4.00       0.00       0.00
       0.00       2.00       1.00       1.00

Converting Stream to String and back...what are we missing?

Try this.

string output1 = Encoding.ASCII.GetString(byteArray, 0, byteArray.Length)

How to disable button in React.js

There are few typical methods how we control components render in React. enter image description here

But, I haven't used any of these in here, I just used the ref's to namespace underlying children to the component.

class AddItem extends React.Component {_x000D_
    change(e) {_x000D_
      if ("" != {_x000D_
        this.button.disabled = false;_x000D_
      } else {_x000D_
        this.button.disabled = true;_x000D_
    add(e) {_x000D_
      this.input.value = '';_x000D_
      this.button.disabled = true;_x000D_
    render() {_x000D_
        return (_x000D_
          <div className="add-item">_x000D_
          <input type="text" className = "add-item__input" ref = {(input) => this.input=input} onChange = {this.change.bind(this)} />_x000D_
          <button className="add-item__button" _x000D_
          onClick= {this.add.bind(this)} _x000D_
          ref={(button) => this.button=button}>Add_x000D_
ReactDOM.render(<AddItem / > , document.getElementById('root'));
<script src=""></script>_x000D_
<script src=""></script>_x000D_
<div id="root"></div>

error: cast from 'void*' to 'int' loses precision

There is no "correct" way to store a 64-bit pointer in an 32-bit integer. The problem is not with casting, but with the target type loosing half of the pointer. The 32 remaining bits stored inside int are insufficient to reconstruct a pointer to the thread function. Most answers just try to extract 32 useless bits out of the argument.

As Ferruccio said, int must be replaced with intptr_t to make the program meaningful.

Calculate percentage Javascript

For percent increase and decrease, using 2 different methods:

const a = 541
const b = 394

// Percent increase 
  `Increase (from ${b} to ${a}) => `,
  (((a/b)-1) * 100).toFixed(2) + "%",

// Percent decrease
  `Decrease (from ${a} to ${b}) => `,
  (((b/a)-1) * 100).toFixed(2) + "%",

// Alternatives, using .toLocaleString() 
  `Increase (from ${b} to ${a}) => `,
  ((a/b)-1).toLocaleString('fullwide', {maximumFractionDigits:2, style:'percent'}),

  `Decrease (from ${a} to ${b}) => `,
  ((b/a)-1).toLocaleString('fullwide', {maximumFractionDigits:2, style:'percent'}),

Unable to cast object of type 'System.DBNull' to type 'System.String`

String.Concat transforms DBNull and null values to an empty string.

public string GetCustomerNumber(Guid id)
   object accountNumber =  
                                new SqlParameter("@id", id));

    return String.Concat(accountNumber);


However, I think you lose something on code understandability

Using Enum values as String literals

You can simply use:

""+ Modes.mode1

Inline style to act as :hover in CSS

If that <p> tag is created from JavaScript, then you do have another option: use JSS to programmatically insert stylesheets into the document head. It does support '&:hover'.

Compare two Timestamp in java

if (!mytime.before(fromtime) && !mytime.after(totime))

"Please provide a valid cache path" error in laravel

If this happens on server:

sudo mkdir logs framework framework/cache framework/sessions framework/views
sudo chgrp -R www-data storage
sudo chmod -R ug+rwx storage

How to convert int to string on Arduino?

Here below is a self composed myitoa() which is by far smaller in code, and reserves a FIXED array of 7 (including terminating 0) in char *mystring, which is often desirable. It is obvious that one can build the code with character-shift instead, if one need a variable-length output-string.

void myitoa(int number, char *mystring) {
  boolean negative = number>0;

  mystring[0] = number<0? '-' : '+';
  number = number<0 ? -number : number;
  for (int n=5; n>0; n--) {
     mystring[n] = ' ';
     if(number > 0) mystring[n] = number%10 + 48;
     number /= 10;

How to add data validation to a cell using VBA

Use this one:

Dim ws As Worksheet
Dim range1 As Range, rng As Range
'change Sheet1 to suit
Set ws = ThisWorkbook.Worksheets("Sheet1")

Set range1 = ws.Range("A1:A5")
Set rng = ws.Range("B1")

With rng.Validation
    .Delete 'delete previous validation
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
        Formula1:="='" & ws.Name & "'!" & range1.Address
End With

Note that when you're using Dim range1, rng As range, only rng has type of Range, but range1 is Variant. That's why I'm using Dim range1 As Range, rng As Range.
About meaning of parameters you can read is MSDN, but in short:

  • Type:=xlValidateList means validation type, in that case you should select value from list
  • AlertStyle:=xlValidAlertStop specifies the icon used in message boxes displayed during validation. If user enters any value out of list, he/she would get error message.
  • in your original code, Operator:= xlBetween is odd. It can be used only if two formulas are provided for validation.
  • Formula1:="='" & ws.Name & "'!" & range1.Address for list data validation provides address of list with values (in format =Sheet!A1:A5)

Tool for sending multipart/form-data request

UPDATE: I have created a video on sending multipart/form-data requests to explain this better.

Actually, Postman can do this. Here is a screenshot

Newer version : Screenshot captured from postman chrome extension enter image description here

Another version

enter image description here

Older version

enter image description here

Make sure you check the comment from @maxkoryukov

Be careful with explicit Content-Type header. Better - do not set it's value, the Postman is smart enough to fill this header for you. BUT, if you want to set the Content-Type: multipart/form-data - do not forget about boundary field.

Setup a Git server with msysgit on Windows

I found this post and I have just posted something on my blog that might help.

See Setting up a Msysgit Server with copSSH on Windows. It's long, but I have successfully got this working on Windows 7 Ultimate x64.

Removing page title and date when printing web page (with CSS?)

You can add this in your stylesheet: @page{size:auto; margin:5mm;} But this discards the page number too


You can try this:

  count(distinct tag) as tag_count,
  count(distinct (case when entryId > 0 then tag end)) as positive_tag_count

The first count(distinct...) is easy. The second one, looks somewhat complex, is actually the same as the first one, except that you use case...when clause. In the case...when clause, you filter only positive values. Zeros or negative values would be evaluated as null and won't be included in count.

One thing to note here is that this can be done by reading the table once. When it seems that you have to read the same table twice or more, it can actually be done by reading once, in most of the time. As a result, it will finish the task a lot faster with less I/O.

Replace one substring for another string in shell script

Since I can't add a comment. @ruaka To make the example more readable write it like this

full_string="I love Suzy and Mary"

Accept function as parameter in PHP

Tested for PHP 5.3

As i see here, Anonymous Function could help you:

What you'll probably need and it's not said before it's how to pass a function without wrapping it inside a on-the-fly-created function. As you'll see later, you'll need to pass the function's name written in a string as a parameter, check its "callability" and then call it.

The function to do check:

if( is_callable( $string_function_name ) ){
    /*perform the call*/

Then, to call it, use this piece of code (if you need parameters also, put them on an array), seen at :

call_user_func_array( "string_holding_the_name_of_your_function", $arrayOfParameters );

as it follows (in a similar, parameterless, way):

    function funToBeCalled(){
        print("----------------------i'm here");
    function wrapCaller($fun){
        if( is_callable($fun)){
            print($fun." not called");

    wrapCaller("cannot call me");

Here's a class explaining how to do something similar :

class HolderValuesOrFunctionsAsString{
    private $functions = array();
    private $vars = array();

    function __set($name,$data){
            $this->functions[$name] = $data;
            $this->vars[$name] = $data;

    function __get($name){
        $t = $this->vars[$name];
            return $t;
            $t = $this->$functions[$name];
            if( isset($t))
                return $t;

    function __call($method,$args=null){
        $fun = $this->functions[$method];
        } else {
            // error out
            print("ERROR: Funciton not found: ". $method);

and an example of usage

    /*create a sample function*/
    function sayHello($some = "all"){
         <br>hello to <?=$some?><br>

    $obj = new HolderValuesOrFunctionsAsString;

    /*do the assignement*/
    $obj->justPrintSomething = 'sayHello'; /*note that the given
        "sayHello" it's a string ! */

    /*now call it*/
    $obj->justPrintSomething(); /*will print: "hello to all" and
        a break-line, for html purpose*/

    /*if the string assigned is not denoting a defined method
         , it's treat as a simple value*/
    $obj->justPrintSomething = 'thisFunctionJustNotExistsLOL';

    echo $obj->justPrintSomething; /*what do you expect to print?
        just that string*/
    /*N.B.: "justPrintSomething" is treated as a variable now!
        as the __set 's override specify"*/

    /*after the assignement, the what is the function's destiny assigned before ? It still works, because it's held on a different array*/
     $obj->justPrintSomething("Jack Sparrow");

     /*You can use that "variable", ie "justPrintSomething", in both ways !! so you can call "justPrintSomething" passing itself as a parameter*/

     $obj->justPrintSomething( $obj->justPrintSomething );
         /*prints: "hello to thisFunctionJustNotExistsLOL" and a break-line*/

    /*in fact, "justPrintSomething" it's a name used to identify both
         a value (into the dictionary of values) or a function-name
         (into the dictionary of functions)*/

Sql Server trigger insert values from new row into another table

try this for sql server

CREATE TRIGGER yourNewTrigger ON yourSourcetable

INSERT INTO yourDestinationTable
        (col1, col2    , col3, user_id, user_name)
        'a'  , default , null, user_id, user_name
        FROM inserted


Gradle, Android and the ANDROID_HOME SDK location


1 add "sdk.dir=path_of_sdk"

2 execute gradlew with evn variable like following:

$ANDROID_HOME=path_of_sdk ./gradlw

Java Generics With a Class & an Interface - Together

You can't do it with "anonymous" type parameters (ie, wildcards that use ?), but you can do it with "named" type parameters. Simply declare the type parameter at method or class level.

import java.util.List;
interface A{}
interface B{}
public class Test<E extends B & A, T extends List<E>> {
    T t;

Magento addFieldToFilter: Two fields, match as OR, not AND

To filter by multiple attributes use something like:

//for AND
    $collection = Mage::getModel('sales/order')->getCollection()
    ->addFieldToFilter('my_field1', 'my_value1')
    ->addFieldToFilter('my_field2', 'my_value2');

    echo $collection->getSelect()->__toString();

//for OR - please note 'attribute' is the key name and must remain the same, only replace //the value (my_field1, my_field2) with your attribute name

    $collection = Mage::getModel('sales/order')->getCollection()
                array('attribute'=>'my_field2', 'eq'=>'my_value2')

For more information check:

What is a "method" in Python?

It's a function which is a member of a class:

class C:
    def my_method(self):
        print("I am a C")

c = C()
c.my_method()  # Prints("I am a C")

Simple as that!

(There are also some alternative kinds of method, allowing you to control the relationship between the class and the function. But I'm guessing from your question that you're not asking about that, but rather just the basics.)

Input type DateTime - Value format?

with momentjs i use


How to start debug mode from command prompt for apache tomcat server?

These instructions worked for me on apache-tomcat-8.5.20 on mac os 10.13.3 using jdk1.8.0_152:

$ cd /path/to/apache-tomcat-8.5.20/bin
$ export JPDA_ADDRESS="localhost:12321"
$ ./ jpda run

Now connect to port 12321 from IntelliJ/Eclipse and enjoy remote debugging.

what does -zxvf mean in tar -zxvf <filename>?

Instead of wading through the description of all the options, you can jump to 3.4.3 Short Options Cross Reference under the info tar command.

x means --extract. v means --verbose. f means --file. z means --gzip. You can combine one-letter arguments together, and f takes an argument, the filename. There is something you have to watch out for:

Short options' letters may be clumped together, but you are not required to do this (as compared to old options; see below). When short options are clumped as a set, use one (single) dash for them all, e.g., ''tar' -cvf'. Only the last option in such a set is allowed to have an argument(1).

This old way of writing 'tar' options can surprise even experienced users. For example, the two commands:

 tar cfz archive.tar.gz file
 tar -cfz archive.tar.gz file

are quite different. The first example uses 'archive.tar.gz' as the value for option 'f' and recognizes the option 'z'. The second example, however, uses 'z' as the value for option 'f' -- probably not what was intended.

import error: 'No module named' *does* exist

I set the PYTHONPATH to '.' and that solved it for me.

export PYTHONPATH='.'

For a one-liner you could as easily do:

PYTHONPATH='.' your_python_script

These commands are expected to be run in a terminal

Creating a class object in c++

I can use the same in c++ like this [...] Where constructor is compulsory. From this tutorial I got that we can create object like this [...] Which do not require an constructor.

This is wrong. A constructor must exist in order to create an object. The constructor could be defined implicitly by the compiler under some conditions if you do not provide any, but eventually the constructor must be there if you want an object to be instantiated. In fact, the lifetime of an object is defined to begin when the constructor routine returns.

From Paragraph 3.8/1 of the C++11 Standard:

[...] The lifetime of an object of type T begins when:

— storage with the proper alignment and size for type T is obtained, and

— if the object has non-trivial initialization, its initialization is complete.

Therefore, a constructor must be present.

1) What is the difference between both the way of creating class objects.

When you instantiate object with automatic storage duration, like this (where X is some class):

X x;

You are creating an object which will be automatically destroyed when it goes out of scope. On the other hand, when you do:

X* x = new X();

You are creating an object dynamically and you are binding its address to a pointer. This way, the object you created will not be destroyed when your x pointer goes out of scope.

In Modern C++, this is regarded as a dubious programming practice: although pointers are important because they allow realizing reference semantics, raw pointers are bad because they could result in memory leaks (objects outliving all of their pointers and never getting destroyed) or in dangling pointers (pointers outliving the object they point to, potentially causing Undefined Behavior when dereferenced).

In fact, when creating an object with new, you always have to remember destroying it with delete:

delete x;

If you need reference semantics and are forced to use pointers, in C++11 you should consider using smart pointers instead:

std::shared_ptr<X> x = std::make_shared<X>();

Smart pointers take care of memory management issues, which is what gives you headache with raw pointers. Smart pointers are, in fact, almost the same as Java or C# object references. The "almost" is necessary because the programmer must take care of not introducing cyclic dependencies through owning smart pointers.

2) If i am creating object like Example example; how to use that in an singleton class.

You could do something like this (simplified code):

struct Example
    static Example& instance()
        static Example example;
        return example;


    Example() { }
    Example(Example const&) = delete;
    Example(Example&&) = delete;
    Example& operator = (Example const&) = delete;
    Example& operator = (Example&&) = delete;


Passing ArrayList from servlet to JSP

public class myActorServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;
    private String name;
    private String user;
    private String pass;
    private String given_table;
    private String tid;
    private String firstname;
    private String lastname;
    private String action;

    public void doPost(HttpServletRequest request,
            HttpServletResponse response)
            throws IOException, ServletException {


        // connecting to database
        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;

        PrintWriter out = response.getWriter();
        name = request.getParameter("screenName");
        user = request.getParameter("username");
        pass = request.getParameter("password");
        tid = request.getParameter("tid");
        firstname = request.getParameter("firstname");
        lastname = request.getParameter("lastname");
        action = request.getParameter("action");
        given_table = request.getParameter("tableName");

        out.println("<title>Servlet JDBC</title>");
        out.println("<link rel=\"stylesheet\" type=\"text/css\" href=\"style.css\">");
        out.println("<h1>Hello, " + name + " </h1>");
        out.println("<h1>Servlet JDBC</h1>");

        // init connection object
        String sqlSelect = "SELECT * FROM `" + given_table + "`";
        String sqlInsert = "INSERT INTO `" + given_table + "`(`firstName`, `lastName`) VALUES ('" + firstname + "', '" + lastname + "')";
        String sqlUpdate = "UPDATE `" + given_table + "` SET `firstName`='" + firstname + "',`lastName`='" + lastname + "' WHERE `id`=" + tid + "";
        String sqlDelete = "DELETE FROM `" + given_table + "` WHERE `id` = '" + tid + "'";

                "<p>Reading Table Data...Pass to JSP File...Okay<p>");

        ArrayList<Actor> list = new ArrayList<Actor>();
        // connecting to database
        try {
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/javabase", user, pass);
            stmt = con.createStatement();
            rs = stmt.executeQuery(sqlSelect);
            // displaying records

            while ( {
                Actor actor = new Actor();
            request.setAttribute("actors", list);
            RequestDispatcher view = request.getRequestDispatcher("myActors_1.jsp");
            view.forward(request, response);

        } catch (SQLException e) {
            throw new ServletException("Servlet Could not display records.", e);
        } catch (ClassNotFoundException e) {
            throw new ServletException("JDBC Driver not found.", e);
        } finally {
            try {
                if (rs != null) {
                    rs = null;
                if (stmt != null) {
                    stmt = null;
                if (con != null) {
                    con = null;
            } catch (SQLException e) {



fstream won't create a file

You need to add some arguments. Also, instancing and opening can be put in one line:

fstream file("test.txt", fstream::in | fstream::out | fstream::trunc);

SFTP file transfer using Java JSch

The most trivial way to upload a file over SFTP with JSch is:

JSch jsch = new JSch();
Session session = jsch.getSession(user, host);

ChannelSftp sftpChannel = (ChannelSftp) session.openChannel("sftp");

sftpChannel.put("C:/source/local/path/", "/target/remote/path/");

Similarly for a download:

sftpChannel.get("/source/remote/path/", "C:/target/local/path/");

You may need to deal with UnknownHostKey exception.

Git fatal: protocol 'https' is not supported

Simple Answer is Just remove the https

Your Repo. : (git clone https://........)

just Like That (git clone ://.......)

and again type (git clone https://........)

Problem Solve 100%...

How to index an element of a list object in R

Indexing a list is done using double bracket, i.e. hypo_list[[1]] (e.g. have a look here: BTW: read.table does not return a table but a dataframe (see value section in ?read.table). So you will have a list of dataframes, rather than a list of table objects. The principal mechanism is identical for tables and dataframes though.

Note: In R, the index for the first entry is a 1 (not 0 like in some other languages).


l <- list(anscombe, iris)   # put dfs in list
l[[1]]             # returns anscombe dataframe

anscombe[1:2, 2]   # access first two rows and second column of dataset
[1] 10  8

l[[1]][1:2, 2]     # the same but selecting the dataframe from the list first
[1] 10  8

Table objects

tbl1 <- table(sample(1:5, 50, rep=T))
tbl2 <- table(sample(1:5, 50, rep=T))
l <- list(tbl1, tbl2)  # put tables in a list

tbl1[1:2]              # access first two elements of table 1 

Now with the list

l[[1]]                 # access first table from the list

1  2  3  4  5 
9 11 12  9  9 

l[[1]][1:2]            # access first two elements in first table

1  2 
9 11 

Oracle Partition - Error ORA14400 - inserted partition key does not map to any partition

select partition_name,column_name,high_value,partition_position
where table_name='YOUR_TABLE' and a.table_name =;

This query lists the column name used as key and the allowed values. make sure, you insert the allowed values(high_value). Else, if default partition is defined, it would go there.


I presume, your TABLE DDL would be like this.

    PARTITION PDIA_98_20091023 VALUES LESS THAN (98,20091024)

Which means I had created a partition with multiple columns which holds value less than the composite range (98,20091024);

That is first COD_PAIS <= 98 and Also FEC_DATA < 20091024

Combinations And Result:

98, 20091024     FAIL
98, 20091023     PASS
99, ********     FAIL
97, ********     PASS
 < 98, ********     PASS

So the below INSERT fails with ORA-14400; because (98,20091024) in INSERT is EQUAL to the one in DDL but NOT less than it.

                                  VALUES(98, 20091024, 'CTA');  2
ERROR at line 1:
ORA-14400: inserted partition key does not map to any partition

But, we I attempt (97,20091024), it goes through

  2                                    VALUES(97, 20091024, 'CTA');

1 row created.

What do 'lazy' and 'greedy' mean in the context of regular expressions?

| Greedy quantifier | Lazy quantifier |        Description           |
| *                 | *?              | Star Quantifier: 0 or more   |
| +                 | +?              | Plus Quantifier: 1 or more   |
| ?                 | ??              | Optional Quantifier: 0 or 1  |
| {n}               | {n}?            | Quantifier: exactly n        |
| {n,}              | {n,}?           | Quantifier: n or more        |
| {n,m}             | {n,m}?          | Quantifier: between n and m  |

Add a ? to a quantifier to make it ungreedy i.e lazy.

test string : stackoverflow
greedy reg expression : s.*o output: stackoverflow
lazy reg expression : s.*?o output: stackoverflow

How to kill all processes matching a name?

If you want to execute the output of a command, you can put it inside $(...), however for your specific task take a look at the killall and pkill commands.

How do search engines deal with AngularJS applications?

You should really check out the tutorial on building an SEO-friendly AngularJS site on the year of moo blog. He walks you through all the steps outlined on Angular's documentation.

Using this technique, the search engine sees the expanded HTML instead of the custom tags.

could not extract ResultSet in hibernate

Another potential cause, for other people coming across the same error message is that this error will occur if you are accessing a table in a different schema from the one you have authenticated with.

In this case you would need to add the schema name to your entity entry:

@Table(name= "catalog", schema = "targetSchemaName")

Why is JavaFX is not included in OpenJDK 8 on Ubuntu Wily (15.10)?

I use ubuntu 16.04 and because I already had openJDK installed, this command have solved the problem. Don't forget that JavaFX is part of OpenJDK.

sudo apt-get install openjfx

How to switch text case in visual studio code

Echoing justanotherdev's comment:

Mind-blowing and useful:

  1. Command Palette: CTRL + SHIFT + p (Mac: CMD + SHIFT + p)
  2. type >transform pick upper/lower case and press enter

enter image description here

How to parseInt in Angular.js

Perform the operation inside the scope itself.

angular.controller('MyCtrl', function($scope, $window) {
$scope.num1= 0;
$scope.num2= 1;

  $ = $scope.num1 + $scope.num2;

<input type="text" ng-model="num1">
<input type="text" ng-model="num2">

Total: {{total}}

What is the difference between '/' and '//' when used for division?

5.0//2 results in 2.0, and not 2 because the return type of the return value from // operator follows python coercion (type casting) rules.

Python promotes conversion of lower datatype (integer) to higher data type (float) to avoid data loss.

Reading e-mails from Outlook with Python through MAPI

I had the same problem you did - didn't find much that worked. The following code, however, works like a charm.

import win32com.client

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")

inbox = outlook.GetDefaultFolder(6) # "6" refers to the index of a folder - in this case,
                                    # the inbox. You can change that number to reference
                                    # any other folder
messages = inbox.Items
message = messages.GetLast()
body_content = message.body
print body_content

Exercises to improve my Java programming skills

Go and buy the book titled "Java examples in a nutshell". In the book you will find most of practical examples.

Path to Powershell.exe (v 2.0)

I believe it's in C:\Windows\System32\WindowsPowershell\v1.0\. In order to confuse the innocent, MS kept it in a directory labeled "v1.0". Running this on Windows 7 and checking the version number via $Host.Version (Determine installed PowerShell version) shows it's 2.0.

Another option is type $PSVersionTable at the command prompt. If you are running v2.0, the output will be:

Name                           Value
----                           -----
CLRVersion                     2.0.50727.4927
BuildVersion                   6.1.7600.16385
PSVersion                      2.0
WSManStackVersion              2.0
PSCompatibleVersions           {1.0, 2.0}
PSRemotingProtocolVersion      2.1

If you're running version 1.0, the variable doesn't exist and there will be no output.

Localization PowerShell version 1.0, 2.0, 3.0, 4.0:

  • 64 bits version: C:\Windows\System32\WindowsPowerShell\v1.0\
  • 32 bits version: C:\Windows\SysWOW64\WindowsPowerShell\v1.0\

Methods vs Constructors in Java

Constructor is special function used to initialise the data member, where the methods are functions to perform specific task.

Constructor name is the same name as the class name, where the method name may or may not or be class name.

Constructor does not allow any return type, where methods allow return type.

vertical & horizontal lines in matplotlib

This may be a common problem for new users of Matplotlib to draw vertical and horizontal lines. In order to understand this problem, you should be aware that different coordinate systems exist in Matplotlib.

The method axhline and axvline are used to draw lines at the axes coordinate. In this coordinate system, coordinate for the bottom left point is (0,0), while the coordinate for the top right point is (1,1), regardless of the data range of your plot. Both the parameter xmin and xmax are in the range [0,1].

On the other hand, method hlines and vlines are used to draw lines at the data coordinate. The range for xmin and xmax are the in the range of data limit of x axis.

Let's take a concrete example,

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 5, 100)
y = np.sin(x)

fig, ax = plt.subplots()

ax.plot(x, y)
ax.axhline(y=0.5, xmin=0.0, xmax=1.0, color='r')
ax.hlines(y=0.6, xmin=0.0, xmax=1.0, color='b')

It will produce the following plot: enter image description here

The value for xmin and xmax are the same for the axhline and hlines method. But the length of produced line is different.

What does $1 [QSA,L] mean in my .htaccess file?

If the following conditions are true, then rewrite the URL:
If the requested filename is not a directory,

RewriteCond %{REQUEST_FILENAME} !-d

and if the requested filename is not a regular file that exists,

RewriteCond %{REQUEST_FILENAME} !-f

and if the requested filename is not a symbolic link,

RewriteCond %{REQUEST_FILENAME} !-l

then rewrite the URL in the following way:
Take the whole request filename and provide it as the value of a "url" query parameter to index.php. Append any query string from the original URL as further query parameters (QSA), and stop processing this .htaccess file (L).

RewriteRule ^(.+)$ index.php?url=$1 [QSA,L]

Apache docs #flag_qsa

Another Example:

RewriteRule "/pages/(.+)" "/page.php?page=$1" [QSA]

With the [QSA] flag, a request for


will be mapped to


Binary Search Tree - Java Implementation

According to Collections Framework Overview you have two balanced tree implementations:

How does one extract each folder name from a path?

    // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    /// <summary>
    /// Use to emulate the C lib function _splitpath()
    /// </summary>
    /// <param name="path">The path to split</param>
    /// <param name="rootpath">optional root if a relative path</param>
    /// <returns>the folders in the path. 
    ///     Item 0 is drive letter with ':' 
    ///     If path is UNC path then item 0 is "\\"
    /// </returns>
    /// <example>
    /// string p1 = @"c:\p1\p2\p3\p4";
    /// string[] ap1 = p1.SplitPath();
    /// // ap1 = {"c:", "p1", "p2", "p3", "p4"}
    /// string p2 = @"\\server\p2\p3\p4";
    /// string[] ap2 = p2.SplitPath();
    /// // ap2 = {@"\\", "server", "p2", "p3", "p4"}
    /// string p3 = @"..\p3\p4";
    /// string root3 = @"c:\p1\p2\";
    /// string[] ap3 = p1.SplitPath(root3);
    /// // ap3 = {"c:", "p1", "p3", "p4"}
    /// </example>
    public static string[] SplitPath(this string path, string rootpath = "")
        string drive;
        string[] astr;
        path = Path.GetFullPath(Path.Combine(rootpath, path));
        if (path[1] == ':')
            drive = path.Substring(0, 2);
            string newpath = path.Substring(2);
            astr = newpath.Split(new[] { Path.DirectorySeparatorChar }
                , StringSplitOptions.RemoveEmptyEntries);
            drive = @"\\";
            astr = path.Split(new[] { Path.DirectorySeparatorChar }
                , StringSplitOptions.RemoveEmptyEntries);
        string[] splitPath = new string[astr.Length + 1];
        splitPath[0] = drive;
        astr.CopyTo(splitPath, 1);
        return splitPath;

Simple way to unzip a .zip file using zlib

Minizip does have an example programs to demonstrate its usage - the files are called minizip.c and miniunz.c.

Update: I had a few minutes so I whipped up this quick, bare bones example for you. It's very smelly C, and I wouldn't use it without major improvements. Hopefully it's enough to get you going for now.

// uzip.c - Simple example of using the minizip API.
// Do not use this code as is! It is educational only, and probably
// riddled with errors and leaks!
#include <stdio.h>
#include <string.h>

#include "unzip.h"

#define dir_delimter '/'
#define MAX_FILENAME 512
#define READ_SIZE 8192

int main( int argc, char **argv )
    if ( argc < 2 )
        printf( "usage:\n%s {file to unzip}\n", argv[ 0 ] );
        return -1;

    // Open the zip file
    unzFile *zipfile = unzOpen( argv[ 1 ] );
    if ( zipfile == NULL )
        printf( "%s: not found\n" );
        return -1;

    // Get info about the zip file
    unz_global_info global_info;
    if ( unzGetGlobalInfo( zipfile, &global_info ) != UNZ_OK )
        printf( "could not read file global info\n" );
        unzClose( zipfile );
        return -1;

    // Buffer to hold data read from the zip file.
    char read_buffer[ READ_SIZE ];

    // Loop to extract all files
    uLong i;
    for ( i = 0; i < global_info.number_entry; ++i )
        // Get info about current file.
        unz_file_info file_info;
        char filename[ MAX_FILENAME ];
        if ( unzGetCurrentFileInfo(
            NULL, 0, NULL, 0 ) != UNZ_OK )
            printf( "could not read file info\n" );
            unzClose( zipfile );
            return -1;

        // Check if this entry is a directory or file.
        const size_t filename_length = strlen( filename );
        if ( filename[ filename_length-1 ] == dir_delimter )
            // Entry is a directory, so create it.
            printf( "dir:%s\n", filename );
            mkdir( filename );
            // Entry is a file, so extract it.
            printf( "file:%s\n", filename );
            if ( unzOpenCurrentFile( zipfile ) != UNZ_OK )
                printf( "could not open file\n" );
                unzClose( zipfile );
                return -1;

            // Open a file to write out the data.
            FILE *out = fopen( filename, "wb" );
            if ( out == NULL )
                printf( "could not open destination file\n" );
                unzCloseCurrentFile( zipfile );
                unzClose( zipfile );
                return -1;

            int error = UNZ_OK;
                error = unzReadCurrentFile( zipfile, read_buffer, READ_SIZE );
                if ( error < 0 )
                    printf( "error %d\n", error );
                    unzCloseCurrentFile( zipfile );
                    unzClose( zipfile );
                    return -1;

                // Write data to file.
                if ( error > 0 )
                    fwrite( read_buffer, error, 1, out ); // You should check return of fwrite...
            } while ( error > 0 );

            fclose( out );

        unzCloseCurrentFile( zipfile );

        // Go the the next entry listed in the zip file.
        if ( ( i+1 ) < global_info.number_entry )
            if ( unzGoToNextFile( zipfile ) != UNZ_OK )
                printf( "cound not read next file\n" );
                unzClose( zipfile );
                return -1;

    unzClose( zipfile );

    return 0;

I built and tested it with MinGW/MSYS on Windows like this:

contrib/minizip/$ gcc -I../.. -o unzip uzip.c unzip.c ioapi.c ../../libz.a
contrib/minizip/$ ./unzip.exe /j/

How to check if the docker engine and a docker container are running?

Sometimes you don't know the full container name, in this case this is what worked for me:

if docker ps | grep -q keyword
    echo "Running!"
    echo "Not running!"
    exit 1

We list all the running container processes (docker ps -a would show us also not running ones, but that's not what I needed), we search for a specific word (grep part) and simply fail if we did not find at least one running container whose name contains our keyword.

Installing specific package versions with pip

One way, as suggested in this post, is to mention version in pip as:

pip install -Iv MySQL_python==1.2.2

i.e. Use == and mention the version number to install only that version. -I, --ignore-installed ignores already installed packages.

Exposing a port on a live Docker container

You cannot do this via Docker, but you can access the container's un-exposed port from the host machine.

If you have a container with something running on its port 8000, you can run

wget http://container_ip:8000

To get the container's IP address, run the 2 commands:

docker ps
docker inspect container_name | grep IPAddress

Internally, Docker shells out to call iptables when you run an image, so maybe some variation on this will work.

To expose the container's port 8000 on your localhost's port 8001:

iptables -t nat -A  DOCKER -p tcp --dport 8001 -j DNAT --to-destination

One way you can work this out is to setup another container with the port mapping you want, and compare the output of the iptables-save command (though, I had to remove some of the other options that force traffic to go via the docker proxy).

NOTE: this is subverting docker, so should be done with the awareness that it may well create blue smoke.


Another alternative is to look at the (new? post 0.6.6?) -P option - which will use random host ports, and then wire those up.


With 0.6.5, you could use the LINKs feature to bring up a new container that talks to the existing one, with some additional relaying to that container's -p flags? (I have not used LINKs yet.)


With docker 0.11? you can use docker run --net host .. to attach your container directly to the host's network interfaces (i.e., net is not namespaced) and thus all ports you open in the container are exposed.

flutter run: No connected devices

Check adb is running or not if not run using the below command

adb start server than adb devices

if adb is not installed in your machine, install it and run commands again.

How to remove element from an array in JavaScript?

Typescript solution that does not mutate original array

function removeElementAtIndex<T>(input: T[], index: number) {
  return input.slice(0, index).concat(input.slice(index + 1));

Meaning of delta or epsilon argument of assertEquals for double values

Which version of JUnit is this? I've only ever seen delta, not epsilon - but that's a side issue!

From the JUnit javadoc:

delta - the maximum delta between expected and actual for which both numbers are still considered equal.

It's probably overkill, but I typically use a really small number, e.g.

private static final double DELTA = 1e-15;

public void testDelta(){
    assertEquals(123.456, 123.456, DELTA);

If you're using hamcrest assertions, you can just use the standard equalTo() with two doubles (it doesn't use a delta). However if you want a delta, you can just use closeTo() (see javadoc), e.g.

private static final double DELTA = 1e-15;

public void testDelta(){
    assertThat(123.456, equalTo(123.456));
    assertThat(123.456, closeTo(123.456, DELTA));

FYI the upcoming JUnit 5 will also make delta optional when calling assertEquals() with two doubles. The implementation (if you're interested) is:

private static boolean doublesAreEqual(double value1, double value2) {
    return Double.doubleToLongBits(value1) == Double.doubleToLongBits(value2);

Generate HTML table from 2D JavaScript array

Here's a function that will use the dom instead of string concatenation.

function createTable(tableData) {
  var table = document.createElement('table');
  var tableBody = document.createElement('tbody');

  tableData.forEach(function(rowData) {
    var row = document.createElement('tr');

    rowData.forEach(function(cellData) {
      var cell = document.createElement('td');



createTable([["row 1, cell 1", "row 1, cell 2"], ["row 2, cell 1", "row 2, cell 2"]]);

HTML 5 Geo Location Prompt in Chrome

For an easy workaround, just copy the HTML file to some cloud share, such as Dropbox, and use the shared link in your browser. Easy.

How to check the version before installing a package using apt-get?

As posted somewhere else, this works, too:

apt-cache madison <package_name>