Programs & Examples On #Apt

Debian's Advanced Packaging Tool whose main binary is apt-get. Most questions about APT are off topic for Stack Overflow, unless it is clearly related to a programming tool.

How to trust a apt repository : Debian apt-get update error public key is not available: NO_PUBKEY <id>

I had the same problem of "gpg: keyserver timed out" with a couple of different servers. Finally, it turned out that I didn't need to do that manually at all. On a Debian system, the simple solution which fixed it was just (as root or precede with sudo):

aptitude install debian-archive-keyring

In case it is some other keyring you need, check out

apt-cache search keyring | grep debian

My squeeze system shows all these:

debian-archive-keyring       - GnuPG archive keys of the Debian archive
debian-edu-archive-keyring   - GnuPG archive keys of the Debian Edu archive
debian-keyring               - GnuPG keys of Debian Developers
debian-ports-archive-keyring - GnuPG archive keys of the debian-ports archive
emdebian-archive-keyring     - GnuPG archive keys for the emdebian repository

What is the difference/usage of homebrew, macports or other package installation tools?

Currently, Macports has many more packages (~18.6 K) than there are Homebrew formulae (~3.1K), owing to its maturity. Homebrew is slowly catching up though.

Macport packages tend to be maintained by a single person.

Macports can keep multiple versions of packages around, and you can enable or disable them to test things out. Sometimes this list can get corrupted and you have to manually edit it to get things back in order, although this is not too hard.

Both package managers will ask to be regularly updated. This can take some time.

Note: you can have both package managers on your system! It is not one or the other. Brew might complain but Macports won't.

Also, if you are dealing with python or ruby packages, use a virtual environment wherever possible.

Amazon Linux: apt-get: command not found

This answer is for complete AWS beginners:

I had this issue but it was because I was trying to run a command from a tutorial inside my Mac computer. What I actually needed to do was SSH into my AWS machine, and then run the same command there. Ta Da, it worked:

enter image description here

Click this button in your EC2 instance, to be able to copy the SSH command. setup your SSH keys https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-key-pairs.html and then you can SSH into your machine

Once here, you can run your sudo apt-get command.

Hope this helps other beginners

E: Unable to locate package npm

I had a similar issue and this is what worked for me.

Add the NodeSource package signing key:

curl -sSL https://deb.nodesource.com/gpgkey/nodesource.gpg.key | sudo apt-key add -
# wget can also be used:
# wget --quiet -O - https://deb.nodesource.com/gpgkey/nodesource.gpg.key | sudo apt-key add -

Add the desired NodeSource repository:

# Replace with the branch of Node.js or io.js you want to install: node_6.x, node_12.x, etc...
VERSION=node_12.x
# The below command will set this correctly, but if lsb_release isn't available, you can set it manually:
# - For Debian distributions: jessie, sid, etc...
# - For Ubuntu distributions: xenial, bionic, etc...
# - For Debian or Ubuntu derived distributions your best option is to use the codename corresponding to the upstream release your distribution is based off. This is an advanced scenario and unsupported if your distribution is not listed as supported per earlier in this README.
DISTRO="$(lsb_release -s -c)"
echo "deb https://deb.nodesource.com/$VERSION $DISTRO main" | sudo tee /etc/apt/sources.list.d/nodesource.list
echo "deb-src https://deb.nodesource.com/$VERSION $DISTRO main" | sudo tee -a /etc/apt/sources.list.d/nodesource.list

Update package lists and install Node.js:

sudo apt-get update
sudo apt-get install nodejs

Install MySQL on Ubuntu without a password prompt

Use:

sudo DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server

sudo mysql -h127.0.0.1 -P3306 -uroot -e"UPDATE mysql.user SET password = PASSWORD('yourpassword') WHERE user = 'root'"

Package php5 have no installation candidate (Ubuntu 16.04)

Currently, I am using Ubuntu 16.04 LTS. Me too was facing same problem while Fetching the Postgress Database values using Php so i resolved it by using the below commands.

Mine PHP version is 7.0, so i tried the below command.

apt-get install php-pgsql

Remember to restart Apache.

/etc/init.d/apache2 restart

How to install "make" in ubuntu?

I have no idea what linux distribution "ubuntu centOS" is. Ubuntu and CentOS are two different distributions.

To answer the question in the header: To install make in ubuntu you have to install build-essentials

sudo apt-get install build-essential

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

Also, according to the man page:

apt-cache showpkg <package_name>

can also be used to:

...display information about the packages listed on the command line. Remaining arguments are package names. The available versions and reverse dependencies of each package listed are listed, as well as forward dependencies for each version. Forward (normal) dependencies are those packages upon which the package in question depends; reverse dependencies are those packages that depend upon the package in question. Thus, forward dependencies must be satisfied for a package, but reverse dependencies need not be.

Ex:

apt-cache policy conky

conky:
  Installed: (none)
  Candidate: 1.10.3-1
  Version table:
     1.10.3-1 500
        500 http://us.archive.ubuntu.com/ubuntu yakkety/universe amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu yakkety/universe i386 Packages

How to update-alternatives to Python 3 without breaking apt?

Somehow python 3 came back (after some updates?) and is causing big issues with apt updates, so I've decided to remove python 3 completely from the alternatives:

root:~# python -V
Python 3.5.2

root:~# update-alternatives --config python
There are 2 choices for the alternative python (providing /usr/bin/python).

  Selection    Path                Priority   Status
------------------------------------------------------------
* 0            /usr/bin/python3.5   3         auto mode
  1            /usr/bin/python2.7   2         manual mode
  2            /usr/bin/python3.5   3         manual mode


root:~# update-alternatives --remove python /usr/bin/python3.5

root:~# update-alternatives --config python
There is 1 choice for the alternative python (providing /usr/bin/python).

    Selection    Path                Priority   Status
------------------------------------------------------------
  0            /usr/bin/python2.7   2         auto mode
* 1            /usr/bin/python2.7   2         manual mode

Press <enter> to keep the current choice[*], or type selection number: 0


root:~# python -V
Python 2.7.12

root:~# update-alternatives --config python
There is only one alternative in link group python (providing /usr/bin/python): /usr/bin/python2.7
Nothing to configure.

How can I get a list of repositories 'apt-get' is checking?

As far as I know, you can't ask apt for what their current sources are. However, you can do what you want using shell tools.

Getting a list of repositories:

grep -h ^deb /etc/apt/sources.list /etc/apt/sources.list.d/* >> current.repos.list

Applying the list:

apt-add-repository << current.repos.list

Regarding getting the repository from a package (installed or available), this will do the trick:

apt-cache policy package_name | grep -m1 http | awk '{ print $2 " " $3 }'

However, that will show you the repository of the latest version available of that package, and you may have more repositories for the same package with older versions. Remove all the grep/awk stuff if you want to see the full list.

How do you run `apt-get` in a dockerfile behind a proxy?

UPDATE:

You have wrong capitalization of environment variables in ENV. Correct one is http_proxy. Your example should be:

FROM ubuntu:13.10
ENV http_proxy <HTTP_PROXY>
ENV https_proxy <HTTPS_PROXY>
RUN apt-get update && apt-get upgrade

or

FROM centos
ENV http_proxy <HTTP_PROXY>
ENV https_proxy <HTTPS_PROXY>
RUN yum update 

All variables specified in ENV are prepended to every RUN command. Every RUN command is executed in own container/environment, so it does not inherit variables from previous RUN commands!

Note: There is no need to call docker daemon with proxy for this to work, although if you want to pull images etc. you need to set the proxy for docker deamon too. You can set proxy for daemon in /etc/default/docker in Ubuntu (it does not affect containers setting).


Also, this can happen in case you run your proxy on host (i.e. localhost, 127.0.0.1). Localhost on host differ from localhost in container. In such case, you need to use another IP (like 172.17.42.1) to bind your proxy to or if you bind to 0.0.0.0, you can use 172.17.42.1 instead of 127.0.0.1 for connection from container during docker build.

You can also look for an example here: How to rebuild dockerfile quick by using cache?

Installing SciPy and NumPy using pip

you need the libblas and liblapack dev packages if you are using Ubuntu.

aptitude install libblas-dev liblapack-dev
pip install scipy

cd into directory without having permission

You've got several options:

  • Use a different user account, one with execute permissions on that directory.
  • Change the permissions on the directory to allow your user account execute permissions.
    • Either use chmod(1) to change the permissions or
    • Use the setfacl(1) command to add an access control list entry for your user account. (This also requires mounting the filesystem with the acl option; see mount(8) and fstab(5) for details on the mount parameter.)

It's impossible to suggest the correct approach without knowing more about the problem; why are the directory permissions set the way they are? Why do you need access to that directory?

How can I find the number of arguments of a Python function?

Adding to the above, I've also seen that the most of the times help() function really helps

For eg, it gives all the details about the arguments it takes.

help(<method>)

gives the below

method(self, **kwargs) method of apiclient.discovery.Resource instance
Retrieves a report which is a collection of properties / statistics for a specific customer.

Args:
  date: string, Represents the date in yyyy-mm-dd format for which the data is to be fetched. (required)
  pageToken: string, Token to specify next page.
  parameters: string, Represents the application name, parameter name pairs to fetch in csv as app_name1:param_name1, app_name2:param_name2.

Returns:
  An object of the form:

    { # JSON template for a collection of usage reports.
    "nextPageToken": "A String", # Token for retrieving the next page
    "kind": "admin#reports#usageReports", # Th

Breaking a list into multiple columns in Latex

I've had multenum for "Multi-column enumerated lists" recommended to me, but I've never actually used it myself, yet.

Edit: The syntax doesn't exactly look like you could easily copy+paste lists into the LaTeX code. So, it may not be the best solution for your use case!

How to see local history changes in Visual Studio Code?

Basic Functionality

  • Automatically saved local edit history is available with the Local History extension.
  • Manually saved local edit history is available with the Checkpoints extension (this is the IntelliJ equivalent to adding tags to the local history).

Advanced Functionality

  • None of the extensions mentioned above support edit history when a file is moved or renamed.
  • The extensions above only support edit history. They do not support move/delete history, for example, like IntelliJ does.

Open Request

If you'd like to see this feature added natively, along with all of the advanced functionality, I'd suggest upvoting the open GitHub issue here.

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

installing Microsoft Visual C++ 2010 SP1 Redistributable Fixed it

CodeIgniter -> Get current URL relative to base url

In CI v3, you can try:

function partial_uri($start = 0) {
    return join('/',array_slice(get_instance()->uri->segment_array(), $start));
}

This will drop the number of URL segments specified by the $start argument. If your URL is http://localhost/dropbox/derrek/shopredux/ahahaha/hihihi, then:

partial_uri(3);  # returns "ahahaha/hihihi"

ExpressionChangedAfterItHasBeenCheckedError Explained

This error indicates a real problem in your application, therefore it makes sense to throw an exception.

In devMode change detection adds an additional turn after every regular change detection run to check if the model has changed.

If the model has changed between the regular and the additional change detection turn, this indicates that either

  • change detection itself has caused a change
  • a method or getter returns a different value every time it is called

which are both bad, because it is not clear how to proceed because the model might never stabilize.

If Angular runs change detection until the model stabilizes, it might run forever. If Angular doesn't run change detection, then the view might not reflect the current state of the model.

See also What is difference between production and development mode in Angular2?

CSS: Hover one element, effect for multiple elements?

This is not difficult to achieve, but you need to use the javascript onmouseover function. Pseudoscript:

<div class="section ">

<div class="image"><img src="myImage.jpg" onmouseover=".layer {border: 1px solid black;} .image {border: 1px solid black;}" /></div>

<div class="layer">Lorem Ipsum</div>

</div>

Use your own colors. You can also reference javascript functions in the mouseover command.

Typescript: difference between String and string

Here is an example that shows the differences, which will help with the explanation.

var s1 = new String("Avoid newing things where possible");
var s2 = "A string, in TypeScript of type 'string'";
var s3: string;

String is the JavaScript String type, which you could use to create new strings. Nobody does this as in JavaScript the literals are considered better, so s2 in the example above creates a new string without the use of the new keyword and without explicitly using the String object.

string is the TypeScript string type, which you can use to type variables, parameters and return values.

Additional notes...

Currently (Feb 2013) Both s1 and s2 are valid JavaScript. s3 is valid TypeScript.

Use of String. You probably never need to use it, string literals are universally accepted as being the correct way to initialise a string. In JavaScript, it is also considered better to use object literals and array literals too:

var arr = []; // not var arr = new Array();
var obj = {}; // not var obj = new Object();

If you really had a penchant for the string, you could use it in TypeScript in one of two ways...

var str: String = new String("Hello world"); // Uses the JavaScript String object
var str: string = String("Hello World"); // Uses the TypeScript string type

Adding timestamp to a filename with mv in BASH

I use this command for simple rotate a file:

mv output.log `date +%F`-output.log

In local folder I have 2019-09-25-output.log

Angular2: child component access parent class variable/function

Basically you can't access variables from parent directly. You do this by events. Component's output property is responsible for this. I would suggest reading https://angular.io/docs/ts/latest/guide/template-syntax.html#input-and-output-properties

How do I paste multi-line bash codes into terminal and run it all at once?

iTerm handles multiple-line command perfectly, it saves multiple-lines command as one command, then we can use Cmd+ Shift + ; to navigate the history.

Check more iTerm tips at Working effectively with iTerm

Adding an identity to an existing column

As I understood in normal cases we are creating a table with Primary key which is having Identity property
So Rename or Delete a column which is associated with Primary Key constraint will not be possible because constraint Rules are validating column structure.
Tto achieve this we have to process some steps in the following way:
Let us assume TableName = 'Employee' and ColumnName = 'EmployeeId'

1. Add new column 'EmployeeId_new' in the 'Employee' table
ALTER TABLE Employee ADD EmployeeId_new INT IDENTITY(1,1)

  1. Now remove column 'EmployeeId' from 'Employee' table
    ALTER TABLE Employee DROP COLUMN EmployeeId

  2. This will throw error because of Primary Key Constraint rules are applicable and validating column structure.
    *### 'Msg 5074, Level 16, State 1, Line 1 The object [PK_dbo.Employee] is dependent on colmn [EmployeeId].'###

  3. So we have to remove the Primary Key constraint first from the table 'Employee' then we can remove the column
    ALTER TABLE Employee DROP constraint [PK_dbo.Employee]

  4. Now we can remove the column 'EmployeeId' from 'Employee' table as did in the previous step where we got error
    ALTER TABLE Employee DROP COLUMN EmployeeId

  5. Now Column 'EmployeeId' removed from table So we will Rename the newly added new column 'EmployeeId_new' with 'EmployeeId'
    sp_rename 'Employee.EmployeeId', 'EmployeeId_new', 'COLUMN'

  6. To rearrange the table in the same form as It was, we have to add Primary Key Constraint for the column 'EmployeeId'
    ALTER TABLE Employee add constraint [PK_dbo.Employee] primary key (EmployeeId)

8. Now the table 'Employee' with 'EmployeeId' is modified for Identity rules along with existing primary key constraint

Conditionally Remove Dataframe Rows with R

Subset is your safest and easiest answer.

subset(dataframe, A==B & E!=0)

Real data example with mtcars

subset(mtcars, cyl==6 & am!=0)

Getting the closest string match

A sample using C# is here.

public static void Main()
{
    Console.WriteLine("Hello World " + LevenshteinDistance("Hello","World"));
    Console.WriteLine("Choice A " + LevenshteinDistance("THE BROWN FOX JUMPED OVER THE RED COW","THE RED COW JUMPED OVER THE GREEN CHICKEN"));
    Console.WriteLine("Choice B " + LevenshteinDistance("THE BROWN FOX JUMPED OVER THE RED COW","THE RED COW JUMPED OVER THE RED COW"));
    Console.WriteLine("Choice C " + LevenshteinDistance("THE BROWN FOX JUMPED OVER THE RED COW","THE RED FOX JUMPED OVER THE BROWN COW"));
}

public static float LevenshteinDistance(string a, string b)
{
    var rowLen = a.Length;
    var colLen = b.Length;
    var maxLen = Math.Max(rowLen, colLen);

    // Step 1
    if (rowLen == 0 || colLen == 0)
    {
        return maxLen;
    }

    /// Create the two vectors
    var v0 = new int[rowLen + 1];
    var v1 = new int[rowLen + 1];

    /// Step 2
    /// Initialize the first vector
    for (var i = 1; i <= rowLen; i++)
    {
        v0[i] = i;
    }

    // Step 3
    /// For each column
    for (var j = 1; j <= colLen; j++)
    {
        /// Set the 0'th element to the column number
        v1[0] = j;

        // Step 4
        /// For each row
        for (var i = 1; i <= rowLen; i++)
        {
            // Step 5
            var cost = (a[i - 1] == b[j - 1]) ? 0 : 1;

            // Step 6
            /// Find minimum
            v1[i] = Math.Min(v0[i] + 1, Math.Min(v1[i - 1] + 1, v0[i - 1] + cost));
        }

        /// Swap the vectors
        var vTmp = v0;
        v0 = v1;
        v1 = vTmp;
    }

    // Step 7
    /// The vectors were swapped one last time at the end of the last loop,
    /// that is why the result is now in v0 rather than in v1
    return v0[rowLen];
}

The output is:

Hello World 4
Choice A 15
Choice B 6
Choice C 8

Cast IList to List

How about this:

List<SubProduct> subProducts = Model.subproduct.ToList();

How to get all files under a specific directory in MATLAB?

With little modification but almost similar approach to get the full file path of each sub folder

dataFolderPath = 'UCR_TS_Archive_2015/';

dirData = dir(dataFolderPath);      %# Get the data for the current directory
dirIndex = [dirData.isdir];  %# Find the index for directories
fileList = {dirData(~dirIndex).name}';  %'# Get a list of the files
if ~isempty(fileList)
    fileList = cellfun(@(x) fullfile(dataFolderPath,x),...  %# Prepend path to files
        fileList,'UniformOutput',false);
end
subDirs = {dirData(dirIndex).name};  %# Get a list of the subdirectories
validIndex = ~ismember(subDirs,{'.','..'});  %# Find index of subdirectories
%#   that are not '.' or '..'
for iDir = find(validIndex)                  %# Loop over valid subdirectories
    nextDir = fullfile(dataFolderPath,subDirs{iDir});    %# Get the subdirectory path
    getAllFiles = dir(nextDir);
    for k = 1:1:size(getAllFiles,1)
        validFileIndex = ~ismember(getAllFiles(k,1).name,{'.','..'});
        if(validFileIndex)
            filePathComplete = fullfile(nextDir,getAllFiles(k,1).name);
            fprintf('The Complete File Path: %s\n', filePathComplete);
        end
    end
end  

Modulo operator with negative values

The sign in such cases (i.e when one or both operands are negative) is implementation-defined. The spec says in §5.6/4 (C++03),

The binary / operator yields the quotient, and the binary % operator yields the remainder from the division of the first expression by the second. If the second operand of / or % is zero the behavior is undefined; otherwise (a/b)*b + a%b is equal to a. If both operands are nonnegative then the remainder is nonnegative; if not, the sign of the remainder is implementation-defined.

That is all the language has to say, as far as C++03 is concerned.

How to use requirements.txt to install all dependencies in a python project

(Taken from my comment)

pip won't handle system level dependencies. You'll have to apt-get install libfreetype6-dev before continuing. (It even says so right in your output. Try skimming over it for such errors next time, usually build outputs are very detailed)

Get bytes from std::string in C++

From a std::string you can use the c_ptr() method if you want to get at the char_t buffer pointer.

It looks like you just want copy the characters of the string into a new buffer. I would simply use the std::string::copy function:

length = str.copy( buffer, str.size() );

How to remove focus around buttons on click

If the above doesn't work for you, try this:

.btn:focus {outline: none;box-shadow: none;border:2px solid transparent;}

As user1933897 pointed out, this might be specific to MacOS with Chrome.

ASP.net using a form to insert data into an sql server table

There are tons of sample code online as to how to do this.

Here is just one example of how to do this: http://geekswithblogs.net/dotNETvinz/archive/2009/04/30/creating-a-simple-registration-form-in-asp.net.aspx

you define the text boxes between the following tag:

<form id="form1" runat="server"> 

you create your textboxes and define them to runat="server" like so:

<asp:TextBox ID="TxtName" runat="server"></asp:TextBox>

define a button to process your logic like so (notice the onclick):

<asp:Button ID="Button1" runat="server" Text="Save" onclick="Button1_Click" />

in the code behind, you define what you want the server to do if the user clicks on the button by defining a method named

protected void Button1_Click(object sender, EventArgs e)

or you could just double click the button in the design view.

Here is a very quick sample of code to insert into a table in the button click event (codebehind)

protected void Button1_Click(object sender, EventArgs e)
{
   string name = TxtName.Text; // Scrub user data

   string connString = ConfigurationManager.ConnectionStrings["yourconnstringInWebConfig"].ConnectionString;
   SqlConnection conn = null;
   try
   {
          conn = new SqlConnection(connString);
          conn.Open();

          using(SqlCommand cmd = new SqlCommand())
          {
                 cmd.Conn = conn;
                 cmd.CommandType = CommandType.Text;
                 cmd.CommandText = "INSERT INTO dummyTable(name) Values (@var)";
                 cmd.Parameters.AddWithValue("@var", name);
                 int rowsAffected = cmd.ExecuteNonQuery();
                 if(rowsAffected ==1)
                 {
                        //Success notification
                 }
                 else
                 {
                        //Error notification
                 }
          }
   }
   catch(Exception ex)
   {
          //log error 
          //display friendly error to user
   }
   finally
   {
          if(conn!=null)
          {
                 //cleanup connection i.e close 
          }
   }
}

Declaring abstract method in TypeScript

I believe that using a combination of interfaces and base classes could work for you. It will enforce behavioral requirements at compile time (rq_ post "below" refers to a post above, which is not this one).

The interface sets the behavioral API that isn't met by the base class. You will not be able to set base class methods to call on methods defined in the interface (because you will not be able to implement that interface in the base class without having to define those behaviors). Maybe someone can come up with a safe trick to allow calling of the interface methods in the parent.

You have to remember to extend and implement in the class you will instantiate. It satisfies concerns about defining runtime-fail code. You also won't even be able to call the methods that would puke if you haven't implemented the interface (such as if you try to instantiate the Animal class). I tried having the interface extend the BaseAnimal below, but it hid the constructor and the 'name' field of BaseAnimal from Snake. If I had been able to do that, the use of a module and exports could have prevented accidental direct instantiation of the BaseAnimal class.

Paste this in here to see if it works for you: http://www.typescriptlang.org/Playground/

// The behavioral interface also needs to extend base for substitutability
interface AbstractAnimal extends BaseAnimal {
    // encapsulates animal behaviors that must be implemented
    makeSound(input : string): string;
}

class BaseAnimal {
    constructor(public name) { }

    move(meters) {
        alert(this.name + " moved " + meters + "m.");
    }
}

// If concrete class doesn't extend both, it cannot use super methods.
class Snake extends BaseAnimal implements AbstractAnimal {
    constructor(name) { super(name); }
    makeSound(input : string): string {
        var utterance = "sssss"+input;
        alert(utterance);
        return utterance;
    }
    move() {
        alert("Slithering...");
        super.move(5);
    }
}

var longMover = new Snake("windy man");

longMover.makeSound("...am I nothing?");
longMover.move();

var fulture = new BaseAnimal("bob fossil");
// compile error on makeSound() because it is not defined.
// fulture.makeSound("you know, like a...")
fulture.move(1);

I came across FristvanCampen's answer as linked below. He says abstract classes are an anti-pattern, and suggests that one instantiate base 'abstract' classes using an injected instance of an implementing class. This is fair, but there are counter arguments made. Read for yourself: https://typescript.codeplex.com/discussions/449920

Part 2: I had another case where I wanted an abstract class, but I was prevented from using my solution above, because the defined methods in the "abstract class" needed to refer to the methods defined in the matching interface. So, I tool FristvanCampen's advice, sort of. I have the incomplete "abstract" class, with method implementations. I have the interface with the unimplemented methods; this interface extends the "abstract" class. I then have a class that extends the first and implements the second (it must extend both because the super constructor is inaccessible otherwise). See the (non-runnable) sample below:

export class OntologyConceptFilter extends FilterWidget.FilterWidget<ConceptGraph.Node, ConceptGraph.Link> implements FilterWidget.IFilterWidget<ConceptGraph.Node, ConceptGraph.Link> {

    subMenuTitle = "Ontologies Rendered"; // overload or overshadow?

    constructor(
        public conceptGraph: ConceptGraph.ConceptGraph,
        graphView: PathToRoot.ConceptPathsToRoot,
        implementation: FilterWidget.IFilterWidget<ConceptGraph.Node, ConceptGraph.Link>
        ){
        super(graphView);
        this.implementation = this;
    }
}

and

export class FilterWidget<N extends GraphView.BaseNode, L extends GraphView.BaseLink<GraphView.BaseNode>> {

    public implementation: IFilterWidget<N, L>

    filterContainer: JQuery;

    public subMenuTitle : string; // Given value in children

    constructor(
        public graphView: GraphView.GraphView<N, L>
        ){

    }

    doStuff(node: N){
        this.implementation.generateStuff(thing);
    }

}

export interface IFilterWidget<N extends GraphView.BaseNode, L extends GraphView.BaseLink<GraphView.BaseNode>> extends FilterWidget<N, L> {

    generateStuff(node: N): string;

}

Using Google Text-To-Speech in Javascript

The below JavaScript code sends "text" to be spoken/converted to mp3 audio to google cloud text-to-speech API and gets mp3 audio content as response back.

 var text-to-speech = function(state) {
    const url = 'https://texttospeech.googleapis.com/v1beta1/text:synthesize?key=GOOGLE_API_KEY'
    const data = {
      'input':{
         'text':'Android is a mobile operating system developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets.'
      },
      'voice':{
         'languageCode':'en-gb',
         'name':'en-GB-Standard-A',
         'ssmlGender':'FEMALE'
      },
      'audioConfig':{
      'audioEncoding':'MP3'
      }
     };
     const otherparam={
        headers:{
           "content-type":"application/json; charset=UTF-8"
        },
        body:JSON.stringify(data),
        method:"POST"
     };
    fetch(url,otherparam)
    .then(data=>{return data.json()})
    .then(res=>{console.log(res.audioContent); })
    .catch(error=>{console.log(error);state.onError(error)})
  };

Trim a string based on the string length

StringUtils.abbreviate from Apache Commons Lang library could be your friend:

StringUtils.abbreviate("abcdefg", 6) = "abc..."
StringUtils.abbreviate("abcdefg", 7) = "abcdefg"
StringUtils.abbreviate("abcdefg", 8) = "abcdefg"
StringUtils.abbreviate("abcdefg", 4) = "a..."

Commons Lang3 even allow to set a custom String as replacement marker. With this you can for example set a single character ellipsis.

StringUtils.abbreviate("abcdefg", "\u2026", 6) = "abcde…"

Why is quicksort better than mergesort?

Wikipedia's explanation is:

Typically, quicksort is significantly faster in practice than other T(nlogn) algorithms, because its inner loop can be efficiently implemented on most architectures, and in most real-world data it is possible to make design choices which minimize the probability of requiring quadratic time.

Quicksort

Mergesort

I think there are also issues with the amount of storage needed for Mergesort (which is O(n)) that quicksort implementations don't have. In the worst case, they are the same amount of algorithmic time, but mergesort requires more storage.

Exit codes in Python

Exit codes of 0 usually mean, "nothing wrong here." However if the programmer of the script didn't follow convention you may have to consult the source to see what it means. Usually a non-zero value is returned as an error code.

Get the last inserted row ID (with SQL statement)

If your SQL Server table has a column of type INT IDENTITY (or BIGINT IDENTITY), then you can get the latest inserted value using:

INSERT INTO dbo.YourTable(columns....)
   VALUES(..........)

SELECT SCOPE_IDENTITY()

This works as long as you haven't inserted another row - it just returns the last IDENTITY value handed out in this scope here.

There are at least two more options - @@IDENTITY and IDENT_CURRENT - read more about how they works and in what way they're different (and might give you unexpected results) in this excellent blog post by Pinal Dave here.

How to check if a user is logged in (how to properly use user.is_authenticated)?

In your view:

{% if user.is_authenticated %}
<p>{{ user }}</p>
{% endif %}

In you controller functions add decorator:

from django.contrib.auth.decorators import login_required
@login_required
def privateFunction(request):

Video 100% width and height

By checking other answers, I used object-fit in CSS:

video {
    object-fit: fill;
}

From MDN (https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit):

The object-fit CSS property specifies how the contents of a replaced element should be fitted to the box established by its used height and width.

Value: fill

The replaced content is sized to fill the element’s content box: the object’s concrete object size is the element’s used width and height.

How to sort an associative array by its values in Javascript?

Continued discussion & other solutions covered at How to sort an (associative) array by value? with the best solution (for my case) being by saml (quoted below).

Arrays can only have numeric indexes. You'd need to rewrite this as either an Object, or an Array of Objects.

var status = new Array();
status.push({name: 'BOB', val: 10});
status.push({name: 'TOM', val: 3});
status.push({name: 'ROB', val: 22});
status.push({name: 'JON', val: 7});

If you like the status.push method, you can sort it with:

status.sort(function(a,b) {
    return a.val - b.val;
});

Laravel 4 Eloquent Query Using WHERE with OR AND OR?

Make use of Parameter Grouping (Laravel 4.2). For your example, it'd be something like this:

Model::where(function ($query) {
    $query->where('a', '=', 1)
          ->orWhere('b', '=', 1);
})->where(function ($query) {
    $query->where('c', '=', 1)
          ->orWhere('d', '=', 1);
});

What does if __name__ == "__main__": do?

You can make the file usable as a script as well as an importable module.

fibo.py (a module named fibo)

# Other modules can IMPORT this MODULE to use the function fib
def fib(n):    # write Fibonacci series up to n
    a, b = 0, 1
    while b < n:
        print(b, end=' ')
        a, b = b, a+b
    print()

# This allows the file to be used as a SCRIPT
if __name__ == "__main__":
    import sys
    fib(int(sys.argv[1]))

Reference: https://docs.python.org/3.5/tutorial/modules.html

Value of type 'T' cannot be converted to

I know similar code that the OP posted in this question from generic parsers. From a performance perspective, you should use Unsafe.As<TFrom, TResult>(ref TFrom source), which can be found in the System.Runtime.CompilerServices.Unsafe NuGet package. It avoids boxing for value types in these scenarios. I also think that Unsafe.As results in less machine code produced by the JIT than casting twice (using (TResult) (object) actualString), but I haven't checked that out.

public TResult ParseSomething<TResult>(ParseContext context)
{
    if (typeof(TResult) == typeof(string))
    {
        var token = context.ParseNextToken();
        string parsedString = token.ParseToDotnetString();
        return Unsafe.As<string, TResult>(ref parsedString);
    }
    else if (typeof(TResult) == typeof(int))
    {
        var token = context.ParseNextToken();
        int parsedInt32 = token.ParseToDotnetInt32();
        // This will not box which might be critical to performance
        return Unsafe.As<int, TResult>(ref parsedInt32); 
    }
    // other cases omitted for brevity's sake
}

Unsafe.As will be replaced by the JIT with efficient machine code instructions, as you can see in the official CoreFX repo:

Source Code of Unsafe.As

What does void do in java?

void means it returns nothing. It does not return a string, you write a string to System.out but you're not returning one.

You must specify what a method returns, even if you're just saying that it returns nothing.

Technically speaking they could have designed the language such that if you don't write a return type then it's assumed to return nothing, however making you explicitly write out void helps to ensure that the lack of a returned value is intentional and not accidental.

String.Format alternative in C++

As already mentioned the C++ way is using stringstreams.

#include <sstream>

string a = "test";
string b = "text.txt";
string c = "text1.txt";

std::stringstream ostr;
ostr << a << " " << b << " > " << c;

Note that you can get the C string from the string stream object like so.

std::string formatted_string = ostr.str();
const char* c_str = formatted_string.c_str();

Can I install/update WordPress plugins without providing FTP access?

WordPress 2.7 lets you upload a zip file directly (there's a link at the bottom of the plugins page) -- no FTP access needed. This is a new feature in 2.7, and it works for plugins only (not themes yet).

How to convert int[] into List<Integer> in Java?

There is no shortcut for converting from int[] to List<Integer> as Arrays.asList does not deal with boxing and will just create a List<int[]> which is not what you want. You have to make a utility method.

int[] ints = {1, 2, 3};
List<Integer> intList = new ArrayList<Integer>(ints.length);
for (int i : ints)
{
    intList.add(i);
}

Drop-down menu that opens up/upward with pure css

If we are use chosen dropdown list, then we can use below css(No JS/JQuery require)

<select chosen="{width: '100%'}" ng- 
   model="modelName" class="form-control input- 
   sm"
   ng- 
   options="persons.persons as 
   persons.persons for persons in 
   jsonData"
   ng- 
   change="anyFunction(anyParam)" 
   required>
   <option value=""> </option>
</select>
<style>   
.chosen-container .chosen-drop {
    border-bottom: 0;
    border-top: 1px solid #aaa;
    top: auto;
    bottom: 40px;
}

.chosen-container.chosen-with-drop .chosen-single {
    border-top-left-radius: 0px;
    border-top-right-radius: 0px;

    border-bottom-left-radius: 5px;
    border-bottom-right-radius: 5px;

    background-image: none;
}

.chosen-container.chosen-with-drop .chosen-drop {
    border-bottom-left-radius: 0px;
    border-bottom-right-radius: 0px;

    border-top-left-radius: 5px;
    border-top-right-radius: 5px;

    box-shadow: none;

    margin-bottom: -16px;
}
</style>

How to get year and month from a date - PHP

Using date() and strtotime() from the docs.

$date = "2012-01-05";

$year = date('Y', strtotime($date));

$month = date('F', strtotime($date));

echo $month

what do <form action="#"> and <form method="post" action="#"> do?

action="" will resolve to the page's address. action="#" will resolve to the page's address + #, which will mean an empty fragment identifier.

Doing the latter might prevent a navigation (new load) to the same page and instead try to jump to the element with the id in the fragment identifier. But, since it's empty, it won't jump anywhere.

Usually, authors just put # in href-like attributes when they're not going to use the attribute where they're using scripting instead. In these cases, they could just use action="" (or omit it if validation allows).

How to pass the password to su/sudo/ssh without overriding the TTY?

When there's no better choice (as suggested by others), then man socat can help:

   (sleep 5; echo PASSWORD; sleep 5; echo ls; sleep 1) |
   socat - EXEC:'ssh -l user server',pty,setsid,ctty

          EXEC’utes an ssh session to server. Uses a pty for communication
          between socat and ssh, makes it ssh’s  controlling  tty  (ctty),
          and makes this pty the owner of a new process group (setsid), so
          ssh accepts the password from socat.

All of the pty,setsid,ctty complexity is necessary and, while you might not need to sleep as long, you will need to sleep. The echo=0 option is worth a look too, as is passing the remote command on ssh's command line.

xlsxwriter: is there a way to open an existing worksheet in my workbook?

After searching a bit about the method to open the existing sheet in xlxs, i discovered

existingWorksheet = wb.get_worksheet_by_name('Your Worksheet name goes here...')
existingWorksheet.write_row(0,0,'xyz')

You can now append/write any data to the open worksheet. I hope it helps. Thanks

Why does ++[[]][+[]]+[+[]] return the string "10"?

Perhaps the shortest possible ways to evaluate an expression into "10" without digits are:

+!+[] + [+[]] // "10"

-~[] + [+[]] // "10"

//========== Explanation ==========\\

+!+[] : +[] Converts to 0. !0 converts to true. +true converts to 1. -~[] = -(-1) which is 1

[+[]] : +[] Converts to 0. [0] is an array with a single element 0.

Then JS evaluates the 1 + [0], thus Number + Array expression. Then the ECMA specification works: + operator converts both operands to a string by calling the toString()/valueOf() functions from the base Object prototype. It operates as an additive function if both operands of an expression are numbers only. The trick is that arrays easily convert their elements into a concatenated string representation.

Some examples:

1 + {} //    "1[object Object]"
1 + [] //    "1"
1 + new Date() //    "1Wed Jun 19 2013 12:13:25 GMT+0400 (Caucasus Standard Time)"

There's a nice exception that two Objects addition results in NaN:

[] + []   //    ""
[1] + [2] //    "12"
{} + {}   //    NaN
{a:1} + {b:2}     //    NaN
[1, {}] + [2, {}] //    "1,[object Object]2,[object Object]"

Update a column in MySQL

if you want to fill all the column:

update 'column' set 'info' where keyID!=0;

How can I calculate the difference between two dates?

You may want to use something like this:

NSDateComponents *components;
NSInteger days;

components = [[NSCalendar currentCalendar] components: NSDayCalendarUnit 
        fromDate: startDate toDate: endDate options: 0];
days = [components day];

I believe this method accounts for situations such as dates that span a change in daylight savings.

How to stretch in width a WPF user control to its window?

Is the Canvas crucial in your window? If not, try removing it and keep the Grid as the main panel. Canvas has no size unless specified, while a Grid normally takes up all available space. Inside the Canvas, the Grid will have no available space.

C# static class constructor

Yes, a static class can have static constructor, and the use of this constructor is initialization of static member.

static class Employee1
{
    static int EmpNo;
    static Employee1()
    {
        EmpNo = 10;
        // perform initialization here
    }
    public static void Add()
    { 

    }
    public static void Add1()
    { 

    }
}

and static constructor get called only once when you have access any type member of static class with class name Class1

Suppose you are accessing the first EmployeeName field then constructor get called this time, after that it will not get called, even if you will access same type member.

 Employee1.EmployeeName = "kumod";
        Employee1.Add();
        Employee1.Add();

Check if two unordered lists are equal

One liner answer to the above question is :-

let the two lists be list1 and list2, and your requirement is to ensure whether two lists have the same elements, then as per me, following will be the best approach :-

if ((len(list1) == len(list2)) and
   (all(i in list2 for i in list1))):
    print 'True'
else:
    print 'False'

The above piece of code will work per your need i.e. whether all the elements of list1 are in list2 and vice-verse.

But if you want to just check whether all elements of list1 are present in list2 or not, then you need to use the below code piece only :-

if all(i in list2 for i in list1):
    print 'True'
else:
    print 'False'

The difference is, the later will print True, if list2 contains some extra elements along with all the elements of list1. In simple words, it will ensure that all the elements of list1 should be present in list2, regardless of whether list2 has some extra elements or not.

installing urllib in Python3.6

This happens because your local module named urllib.py shadows the installed requests module you are trying to use. The current directory is preapended to sys.path, so the local name takes precedence over the installed name.

An extra debugging tip when this comes up is to look at the Traceback carefully, and realize that the name of your script in question is matching the module you are trying to import.

Rename your file to something else like url.py. Then It is working fine. Hope it helps!

Remove all occurrences of a value from a list?

If you didn't have built-in filter or didn't want to use extra space and you need a linear solution...

def remove_all(A, v):
    k = 0
    n = len(A)
    for i in range(n):
        if A[i] !=  v:
            A[k] = A[i]
            k += 1

    A = A[:k]

pandas: best way to select all columns whose names start with X

My solution. It may be slower on performance:

a = pd.concat(df[df[c] == 1] for c in df.columns if c.startswith('foo'))
a.sort_index()


   bar.baz  foo.aa  foo.bars  foo.fighters  foo.fox foo.manchu nas.foo
0      5.0     1.0         0             0        2         NA      NA
1      5.0     2.1         0             1        4          0       0
2      6.0     NaN         0           NaN        1          0       1
5      6.8     6.8         1             0        5          0       0

How do I get a PHP class constructor to call its parent's parent's constructor?

You can call Grandpa::__construct from where you want and the $this keyword will refer to your current class instance. But be carefull with this method you cannot access to protected properties and methods of current instance from this other context, only to public elements. => All work and officialy supported.

Example

// main class that everything inherits
class Grandpa 
{
    public function __construct()
    {
        echo $this->one; // will print 1
        echo $this->two; // error cannot access protected property
    }

}

class Papa extends Grandpa
{
    public function __construct()
    {
        // call Grandpa's constructor
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public $one = 1;
    protected $two = 2;
    public function __construct()
    {
        Grandpa::__construct();
    }
}

new Kiddo();

Get random boolean in Java

Words in a text are always a source of randomness. Given a certain word, nothing can be inferred about the next word. For each word, we can take the ASCII codes of its letters, add those codes to form a number. The parity of this number is a good candidate for a random boolean.

Possible drawbacks:

  1. this strategy is based upon using a text file as a source for the words. At some point, the end of the file will be reached. However, you can estimate how many times you are expected to call the randomBoolean() function from your app. If you will need to call it about 1 million times, then a text file with 1 million words will be enough. As a correction, you can use a stream of data from a live source like an online newspaper.

  2. using some statistical analysis of the common phrases and idioms in a language, one can estimate the next word in a phrase, given the first words of the phrase, with some degree of accuracy. But statistically, these cases are rare, when we can accuratelly predict the next word. So, in most cases, the next word is independent on the previous words.

    package p01;

    import java.io.File; import java.nio.file.Files; import java.nio.file.Paths;

    public class Main {

    String words[];
    int currentIndex=0;
    
    public static String readFileAsString()throws Exception 
      { 
        String data = ""; 
        File file = new File("the_comedy_of_errors");
        //System.out.println(file.exists());
        data = new String(Files.readAllBytes(Paths.get(file.getName()))); 
        return data; 
      } 
    
    public void init() throws Exception
    {
        String data = readFileAsString(); 
        words = data.split("\\t| |,|\\.|'|\\r|\\n|:");
    }
    
    public String getNextWord() throws Exception
    {
        if(currentIndex>words.length-1)
            throw new Exception("out of words; reached end of file");
    
        String currentWord = words[currentIndex];
        currentIndex++;
    
        while(currentWord.isEmpty())
        {
            currentWord = words[currentIndex];
            currentIndex++;
        }
    
        return currentWord;
    }
    
    public boolean getNextRandom() throws Exception
    {
        String nextWord = getNextWord();
        int asciiSum = 0;
    
        for (int i = 0; i < nextWord.length(); i++){
            char c = nextWord.charAt(i);        
            asciiSum = asciiSum + (int) c;
        }
    
        System.out.println(nextWord+"-"+asciiSum);
    
        return (asciiSum%2==1) ;
    }
    
    public static void main(String args[]) throws Exception
    {
        Main m = new Main();
        m.init();
        while(true)
        {
            System.out.println(m.getNextRandom());
            Thread.sleep(100);
        }
    }
    

    }

In Eclipse, in the root of my project, there is a file called 'the_comedy_of_errors' (no extension) - created with File> New > File , where I pasted some content from here: http://shakespeare.mit.edu/comedy_errors/comedy_errors.1.1.html

React proptype array with shape

This was my solution to protect against an empty array as well:

import React, { Component } from 'react';
import { arrayOf, shape, string, number } from 'prop-types';

ReactComponent.propTypes = {
  arrayWithShape: (props, propName, componentName) => {
    const arrayWithShape = props[propName]
    PropTypes.checkPropTypes({ arrayWithShape:
        arrayOf(
          shape({
            color: string.isRequired,
            fontSize: number.isRequired,
          }).isRequired
      ).isRequired
    }, {arrayWithShape}, 'prop', componentName);
    if(arrayWithShape.length < 1){
      return new Error(`${propName} is empty`)
    }
  }
}

How to place Text and an Image next to each other in HTML?

You can use vertical-align and floating.

In most cases you want to vertical-align: middle, the image.

Here is a test: http://www.w3schools.com/cssref/tryit.asp?filename=trycss_vertical-align

vertical-align: baseline|length|sub|super|top|text-top|middle|bottom|text-bottom|initial|inherit;

For middle, the definition is: The element is placed in the middle of the parent element.

So you might want to apply that to all elements within the element.

Finding the max/min value in an array of primitives using Java

Pass the array to a method that sorts it with Arrays.sort() so it only sorts the array the method is using then sets min to array[0] and max to array[array.length-1].

What is the simplest C# function to parse a JSON string into an object?

You should create a structure that represents JSON keys (in case if you exactly know it) and then you can easily deserialize JSON string into your structure. In my examle I've deserialized a response from Google Cloud Message server:

class templateResponse
{
    public String multicast_id;
    public String success;
    public String failure;
    public String canonical_ids;
    public Result[] results;

    public class Result
    {
        public String message_id;
        public String registration_id;
        public String error;
    };
}

incoming JSON was:

"\"multicast_id\":7400896764380883211,\"success\":1,\"failure\":0,\"canonical_ids\":0,\"results\":[{\"message_id\":\"0:1351777805148960%39895cf0f9fd7ecd\"}]}"

So, use

templateResponse result = new JavaScriptSerializer().Deserialize<templateResponse>(json);

and you will get deserialized result object

Http 415 Unsupported Media type error with JSON

HttpVerb needs its headers as a dictionary of key-value pairs

headers = {'Content-Type': 'application/json', 'charset': 'utf-8'}

Plotting multiple curves same graph and same scale

I'm not sure what you want, but i'll use lattice.

x = rep(x,2)
y = c(y1,y2)
fac.data = as.factor(rep(1:2,each=5))
df = data.frame(x=x,y=y,z=fac.data)
# this create a data frame where I have a factor variable, z, that tells me which data I have (y1 or y2)

Then, just plot

xyplot(y ~x|z, df)
# or maybe
xyplot(x ~y|z, df)

Double precision floating values in Python?

Decimal datatype

  • Unlike hardware based binary floating point, the decimal module has a user alterable precision (defaulting to 28 places) which can be as large as needed for a given problem.

If you are pressed by performance issuses, have a look at GMPY

How to convert UTF-8 byte[] to string?

Definition:

public static string ConvertByteToString(this byte[] source)
{
    return source != null ? System.Text.Encoding.UTF8.GetString(source) : null;
}

Using:

string result = input.ConvertByteToString();

How to delete last character in a string in C#?

It's good practice to use a StringBuilder when concatenating a lot of strings and you can then use the Remove method to get rid of the final character.

StringBuilder paramBuilder = new StringBuilder();

foreach (var item in itemsToAdd)
{
    paramBuilder.AppendFormat(("productID={0}&", item.prodID.ToString());
}

if (paramBuilder.Length > 1)
    paramBuilder.Remove(paramBuilder.Length-1, 1);

string s = paramBuilder.ToString();

How to remove constraints from my MySQL table?

Also nice, you can temporarily disable all foreign key checks from a mysql database: SET FOREIGN_KEY_CHECKS=0; And to enable it again: SET FOREIGN_KEY_CHECKS=1;

How to subtract 30 days from the current date using SQL Server

You can convert it to datetime, and then use DATEADD(DAY, -30, date).

See here.

edit

I suspect many people are finding this question because they want to substract from current date (as is the title of the question, but not what OP intended). The comment of munyul below answers that question more specifically. Since comments are considered ethereal (may be deleted at any given point), I'll repeat it here:

DATEADD(DAY, -30, GETDATE())

PHP - find entry by object property from an array of objects

Try

$entry = current(array_filter($array, function($e) use($v){ return $e->ID==$v; }));

working example here

How to get a list of properties with a given attribute?

The solution I end up using most is based off of Tomas Petricek's answer. I usually want to do something with both the attribute and property.

var props = from p in this.GetType().GetProperties()
            let attr = p.GetCustomAttributes(typeof(MyAttribute), true)
            where attr.Length == 1
            select new { Property = p, Attribute = attr.First() as MyAttribute};

Twitter Bootstrap alert message close and open again

I've tried all the methods and the best way for me is to use the built-in bootstrap classes .fade and .in

Example:

<div class="alert alert-danger fade <?php echo ($show) ? 'in' : '' ?>" role="alert">...</div>

Note: In jQuery, addClass('in') to show the alert, removeClass('in') to hide it.

Fun fact: This works for all elements. Not just alerts.

How to create a video from images with FFmpeg?

cat *.png | ffmpeg -f image2pipe -i - output.mp4

from wiki

How to get the MD5 hash of a file in C++?

You can implement the MD5 algorithm yourself (examples are all over the web), or you can link against the OpenSSL libs and use OpenSSL's digest functions. here's an example to get the MD5 of a byte array:

#include <openssl/md5.h>
QByteArray AESWrapper::md5 ( const QByteArray& data) {
    unsigned char * tmp_hash;
    tmp_hash = MD5((const unsigned char*)data.constData(), data.length(), NULL);
    return QByteArray((const char*)tmp_hash, MD5_DIGEST_LENGTH);
}

Remove multiple objects with rm()

An other solution rm(list=ls(pattern="temp")), remove all objects matching the pattern.

Running an outside program (executable) in Python?

Use subprocess, it is a smaller module so it runs the .exe quicker.

import subprocess
subprocess.Popen([r"U:\Year 8\kerbal space program\KSP.exe"])

Git - remote: Repository not found

I was facing this error in VS code because I was using VS code git extension. It saves my git credentials on Linux key-ring. While I wanted to git pull from another account which has access to the repository. The most simple solution is to open the Linux shell (not the one integrated in VS code) and then run:

git pull origin master

This time, it will ask you the username and password of Github.

#1055 - Expression of SELECT list is not in GROUP BY clause and contains nonaggregated column this is incompatible with sql_mode=only_full_group_by

Same thing is happened with 8.0+ versions as well. By default in 8.0+ version it is "enabled" by default. Here is the link official document reference

In case of 5.6+, 5.7+ versions, the property "ONLY_FULL_GROUP_BY" is disabled by default.

To disabled it, follow the same steps suggested by @Miloud BAKTETE

Remove files from Git commit

I copied the current files in a different folder, then get rid of all unpushed changes by:

git reset --hard @{u}

Then copy things back. Commit, Push.

add Shadow on UIView using swift 3

    func shadow(Vw : UIView)
    {
        Vw.layer.masksToBounds = false
        Vw.layer.shadowColor =  colorLiteral(red: 0.5058823529, green: 0.5333333333, blue: 0.6117647059, alpha: 1)
        Vw.layer.shadowOffset = CGSize(width: 0, height: 1)
        Vw.layer.shadowRadius = 5.0
        Vw.layer.shadowOpacity = 15.0
        Vw.layer.cornerRadius = 5.0
    }

Detect current device with UI_USER_INTERFACE_IDIOM() in Swift

FYI, I have used UI_USER_INTERFACE_IDIOM() for my app written in Swift. The app can be compiled well with XCode 6.3.1 without any warning on that command, runs well on Simulator (with any selected devices) and on all my real devices (iPhone, iPad) with iOS versions from 7.1 to 8.3.

However, the app crashed on Apple reviewers' devices (and was refused). That took me few days to detect the problem with few more re-uploads to iTunes Connect.

Now I use UIDevice.currentDevice().userInterfaceIdiom instead and my app can survive from such crashes.

Datanode process not running in Hadoop

Instead of deleting everything under the "hadoop tmp dir", you can set another one. For example, if your core-site.xml has this property:

<property>
  <name>hadoop.tmp.dir</name>
  <value>/home/hduser/data/tmp</value>
</property>

You can change this to:

<property>
  <name>hadoop.tmp.dir</name>
  <value>/home/hduser/data/tmp2</value>
</property>

and then scp core-site.xml to each node, and then "hadoop namenode -format", and then restart hadoop.

Apache 2.4.3 (with XAMPP 1.8.1) not starting in windows 8

Enter services.msc and shutdown anything SQL you have running. The SQL server might be taking over the port.

Getting String Value from Json Object Android

Include org.json.jsonobject in your project.

You can then do this:

JSONObject jresponse = new JSONObject(responseString);
responseString = jresponse.getString("NeededString");

Assuming, responseString holds the response you receive.

If you need to know how to convert the received response to a String, here's how to do it:

ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
String responseString = out.toString();

Unable to Install Any Package in Visual Studio 2015

You need to Clear All NuGet Caches; for this you need go to Options and click on it like this:

enter image description here

Mail not sending with PHPMailer over SSL using SMTP

I got a similar failure with SMTP whenever my client machine changes network connection (e.g., home vs. office network) and somehow restarting network service (or rebooting the machine) resolves the issue for me. Not sure if this would apply to your case, but just in case.

sudo /etc/init.d/networking restart   # for ubuntu

How can I use std::maps with user-defined types as key?

You don't have to define operator< for your class, actually. You can also make a comparator function object class for it, and use that to specialize std::map. To extend your example:

struct Class1Compare
{
   bool operator() (const Class1& lhs, const Class1& rhs) const
   {
       return lhs.id < rhs.id;
   }
};

std::map<Class1, int, Class1Compare> c2int;

It just so happens that the default for the third template parameter of std::map is std::less, which will delegate to operator< defined for your class (and fail if there is none). But sometimes you want objects to be usable as map keys, but you do not actually have any meaningful comparison semantics, and so you don't want to confuse people by providing operator< on your class just for that. If that's the case, you can use the above trick.

Yet another way to achieve the same is to specialize std::less:

namespace std
{
    template<> struct less<Class1>
    {
       bool operator() (const Class1& lhs, const Class1& rhs) const
       {
           return lhs.id < rhs.id;
       }
    };
}

The advantage of this is that it will be picked by std::map "by default", and yet you do not expose operator< to client code otherwise.

Abstract class in Java

An abstract class is one that isn't fully implemented but provides something of a blueprint for subclasses. It may be partially implemented in that it contains fully-defined concrete methods, but it can also hold abstract methods. These are methods with a signature but no method body. Any subclass must define a body for each abstract method, otherwise it too must be declared abstract. Because abstract classes cannot be instantiated, they must be extended by at least one subclass in order to be utilized. Think of the abstract class as the generic class, and the subclasses are there to fill in the missing information.

What is the default value for enum variable?

You can use this snippet :-D

using System;
using System.Reflection;

public static class EnumUtils
{
    public static T GetDefaultValue<T>()
        where T : struct, Enum
    {
        return (T)GetDefaultValue(typeof(T));
    }

    public static object GetDefaultValue(Type enumType)
    {
        var attribute = enumType.GetCustomAttribute<DefaultValueAttribute>(inherit: false);
        if (attribute != null)
            return attribute.Value;

        var innerType = enumType.GetEnumUnderlyingType();
        var zero = Activator.CreateInstance(innerType);
        if (enumType.IsEnumDefined(zero))
            return zero;

        var values = enumType.GetEnumValues();
        return values.GetValue(0);
    }
}

Example:

using System;

public enum Enum1
{
    Foo,
    Bar,
    Baz,
    Quux
}
public enum Enum2
{
    Foo  = 1,
    Bar  = 2,
    Baz  = 3,
    Quux = 0
}
public enum Enum3
{
    Foo  = 1,
    Bar  = 2,
    Baz  = 3,
    Quux = 4
}
[DefaultValue(Enum4.Bar)]
public enum Enum4
{
    Foo  = 1,
    Bar  = 2,
    Baz  = 3,
    Quux = 4
}

public static class Program 
{
    public static void Main() 
    {
        var defaultValue1 = EnumUtils.GetDefaultValue<Enum1>();
        Console.WriteLine(defaultValue1); // Foo

        var defaultValue2 = EnumUtils.GetDefaultValue<Enum2>();
        Console.WriteLine(defaultValue2); // Quux

        var defaultValue3 = EnumUtils.GetDefaultValue<Enum3>();
        Console.WriteLine(defaultValue3); // Foo

        var defaultValue4 = EnumUtils.GetDefaultValue<Enum4>();
        Console.WriteLine(defaultValue4); // Bar
    }
}

background-image: url("images/plaid.jpg") no-repeat; wont show up

You may debug using two ways:

  1. Press CTRL+U to view page Source . Press CTRL+F to find "mystyles.css" in source . click on mystyles.css link and check if it is not showing "404 not found".

  2. You can INSPECT ELEMENT IN FIRBUG and set path to Image ,Set Image height and width because sometimes image doesnt show up.

Hope this may works !!.

Make an Android button change background on click through XML

To change image by using code

public void onClick(View v) {
   if(v == ButtonName) {
     ButtonName.setImageResource(R.drawable.ImageName);
   }
}

Or, using an XML file:

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_pressed="true"
   android:drawable="@drawable/login_selected" /> <!-- pressed -->
  <item android:state_focused="true"
   android:drawable="@drawable/login_mouse_over" /> <!-- focused -->
  <item android:drawable="@drawable/login" /> <!-- default -->
</selector>

In OnClick, just add this code:

ButtonName.setBackgroundDrawable(getResources().getDrawable(R.drawable.ImageName));

Why do I need to override the equals and hashCode methods in Java?

It is useful when using Value Objects. The following is an excerpt from the Portland Pattern Repository:

Examples of value objects are things like numbers, dates, monies and strings. Usually, they are small objects which are used quite widely. Their identity is based on their state rather than on their object identity. This way, you can have multiple copies of the same conceptual value object.

So I can have multiple copies of an object that represents the date 16 Jan 1998. Any of these copies will be equal to each other. For a small object such as this, it is often easier to create new ones and move them around rather than rely on a single object to represent the date.

A value object should always override .equals() in Java (or = in Smalltalk). (Remember to override .hashCode() as well.)

Node.js/Windows error: ENOENT, stat 'C:\Users\RT\AppData\Roaming\npm'

Install a stable version instead of the latest one, I have downgrade my version to node-v0.10.29-x86.msi from 'node-v0.10.33-x86.msi' and it is working well for me!

http://blog.nodejs.org/2014/06/16/node-v0-10-29-stable/

Does a VPN Hide my Location on Android?

Your question can be conveniently divided into several parts:

Does a VPN hide location? Yes, he is capable of this. This is not about GPS determining your location. If you try to change the region via VPN in an application that requires GPS access, nothing will work. However, sites define your region differently. They get an IP address and see what country or region it belongs to. If you can change your IP address, you can change your region. This is exactly what VPNs can do.

How to hide location on Android? There is nothing difficult in figuring out how to set up a VPN on Android, but a couple of nuances still need to be highlighted. Let's start with the fact that not all Android VPNs are created equal. For example, VeePN outperforms many other services in terms of efficiency in circumventing restrictions. It has 2500+ VPN servers and a powerful IP and DNS leak protection system.

You can easily change the location of your Android device by using a VPN. Follow these steps for any device model (Samsung, Sony, Huawei, etc.):

  1. Download and install a trusted VPN.

  2. Install the VPN on your Android device.

  3. Open the application and connect to a server in a different country.

  4. Your Android location will now be successfully changed!

Is it legal? Yes, changing your location on Android is legal. Likewise, you can change VPN settings in Microsoft Edge on your PC, and all this is within the law. VPN allows you to change your IP address, safeguarding your privacy and protecting your actual location from being exposed. However, VPN laws may vary from country to country. There are restrictions in some regions.

Brief summary: Yes, you can change your region on Android and a VPN is a necessary assistant for this. It's simple, safe and legal. Today, VPN is the best way to change the region and unblock sites with regional restrictions.

Using % for host when creating a MySQL user

localhost is special in MySQL, it means a connection over a UNIX socket (or named pipes on Windows, I believe) as opposed to a TCP/IP socket. Using % as the host does not include localhost, hence the need to explicitly specify it.

How to communicate between Docker containers via "hostname"

As far as I know, by using only Docker this is not possible. You need some DNS to map container ip:s to hostnames.

If you want out of the box solution. One solution is to use for example Kontena. It comes with network overlay technology from Weave and this technology is used to create virtual private LAN networks for each service and every service can be reached by service_name.kontena.local-address.

Here is simple example of Wordpress application's YAML file where Wordpress service connects to MySQL server with wordpress-mysql.kontena.local address:

wordpress:                                                                         
  image: wordpress:4.1                                                             
  stateful: true                                                                   
  ports:                                                                           
    - 80:80                                                                      
  links:                                                                           
    - mysql:wordpress-mysql                                                        
  environment:                                                                     
    - WORDPRESS_DB_HOST=wordpress-mysql.kontena.local                              
    - WORDPRESS_DB_PASSWORD=secret                                                 
mysql:                                                                             
  image: mariadb:5.5                                                               
  stateful: true                                                                   
  environment:                                                                     
    - MYSQL_ROOT_PASSWORD=secret

How to edit HTML input value colour?

Maybe something like this (just add your style):

<input type="text" 
       size="35" 
       value="Job Title e.g. Assistant Manager" 
       style="background-color:white; 
              border: solid 1px #6E6E6E;
              height: 30px; 
              font-size:18px; 
              vertical-align:9px;color:#bbb" 
        onfocus="if(this.value == 'Job Title e.g. Assistant Manager') {
                    this.value = '';
                    this.style.color='#000';
                 }" />

<input type="text" 
       name="searchterm" size="35" 
       style="background-color:white; 
              border: solid 1px #6E6E6E;
              height: 30px; 
              font-size:18px; 
              vertical-align:9px" />

UPDATE: Since placeholder attribute is very well supported on all major browsers, there is no need to do anything manually. Its possible to achieve the same thing with this:

<input type="text" 
       size="35" 
       placeholder="Job Title e.g. Assistant Manager" />

Convert hex string to int

An additional option to the ones suggested, is to use the BigInteger class. Since hex values are often large numbers, such as sha256 or sha512 values, they will easily overflow an int and a long. While converting to a byte array is an option as other answers show, BigInterger, the often forgotten class in java, is an option as well.

String sha256 = "65f4b384672c2776116d8d6533c69d4b19d140ddec5c191ea4d2cfad7d025ca2";
BigInteger value = new BigInteger(sha256, 16);
System.out.println("value = " + value);
// 46115947372890196580627454674591875001875183744738980595815219240926424751266

Override browser form-filling and input highlighting with HTML/CSS

The form element has an autocomplete attribute that you can set to off. As of the CSS the !important directive after a property keeps it from being overriden:

background-color: white !important;

Only IE6 doesn't understand it.

If I misunderstood you, there's also the outline property that you could find useful.

Inserting a string into a list without getting split into characters

Don't use list as a variable name. It's a built in that you are masking.

To insert, use the insert function of lists.

l = ['hello','world']
l.insert(0, 'foo')
print l
['foo', 'hello', 'world']

How to round up integer division and have int result in Java?

If you want to calculate a divided by b rounded up you can use (a+(-a%b))/b

Getting index value on razor foreach

Is there a reason you're not using CSS selectors to style the first and last elements instead of trying to attach a custom class to them? Instead of styling based on alpha or omega, use first-child and last-child.

http://www.quirksmode.org/css/firstchild.html

MySQL SELECT DISTINCT multiple columns

Another simple way to do it is with concat()

SELECT DISTINCT(CONCAT(a,b)) AS cc FROM my_table GROUP BY (cc);

sweet-alert display HTML code in text

I just applied the patch above and it starts working.

_x000D_
_x000D_
diff --git a/sweet-alert.js b/sweet-alert.js_x000D_
index ab6e1f1..d7eafaa 100755_x000D_
--- a/sweet-alert.js_x000D_
+++ b/sweet-alert.js_x000D_
@@ -200,7 +200,8 @@_x000D_
       confirmButtonColor: '#AEDEF4',_x000D_
       cancelButtonText: 'Cancel',_x000D_
       imageUrl: null,_x000D_
-      imageSize: null_x000D_
+      imageSize: null,_x000D_
+      html: false_x000D_
     };_x000D_
 _x000D_
     if (arguments[0] === undefined) {_x000D_
@@ -224,6 +225,7 @@_x000D_
           return false;_x000D_
         }_x000D_
 _x000D_
+        params.html               = arguments[0].html;_x000D_
         params.title              = arguments[0].title;_x000D_
         params.text               = arguments[0].text || params.text;_x000D_
         params.type               = arguments[0].type || params.type;_x000D_
@@ -477,11 +479,18 @@_x000D_
         $cancelBtn = modal.querySelector('button.cancel'),_x000D_
         $confirmBtn = modal.querySelector('button.confirm');_x000D_
 _x000D_
+      console.log(params.html);_x000D_
     // Title_x000D_
-    $title.innerHTML = escapeHtml(params.title).split("\n").join("<br>");_x000D_
+    if(params.html)_x000D_
+      $title.innerHTML = params.title.split("\n").join("<br>");_x000D_
+    else_x000D_
+      $title.innerHTML = escapeHtml(params.title).split("\n").join("<br>");_x000D_
 _x000D_
     // Text_x000D_
-    $text.innerHTML = escapeHtml(params.text || '').split("\n").join("<br>");_x000D_
+    if(params.html)_x000D_
+      $text.innerHTML = params.text.split("\n").join("<br>");_x000D_
+    else_x000D_
+      $text.innerHTML = escapeHtml(params.text || '').split("\n").join("<br>");_x000D_
     if (params.text) {_x000D_
       show($text);_x000D_
     }
_x000D_
_x000D_
_x000D_

Save and retrieve image (binary) from SQL Server using Entity Framework 6

Convert the image to a byte[] and store that in the database.


Add this column to your model:

public byte[] Content { get; set; }

Then convert your image to a byte array and store that like you would any other data:

public byte[] ImageToByteArray(System.Drawing.Image imageIn)
{
    using(var ms = new MemoryStream())
    {
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);

        return ms.ToArray();
    }
}

public Image ByteArrayToImage(byte[] byteArrayIn)
{
     using(var ms = new MemoryStream(byteArrayIn))
     {
         var returnImage = Image.FromStream(ms);

         return returnImage;
     }
}

Source: Fastest way to convert Image to Byte array

var image = new ImageEntity()
{
   Content = ImageToByteArray(image)
};

_context.Images.Add(image);
_context.SaveChanges();

When you want to get the image back, get the byte array from the database and use the ByteArrayToImage and do what you wish with the Image

This stops working when the byte[] gets to big. It will work for files under 100Mb

Ruby value of a hash key?

I didn't understand your problem clearly but I think this is what you're looking for(Based on my understanding)

  person =   {"name"=>"BillGates", "company_name"=>"Microsoft", "position"=>"Chairman"}

  person.delete_if {|key, value| key == "name"} #doing something if the key == "something"

  Output: {"company_name"=>"Microsoft", "position"=>"Chairman"}

jQuery class within class selector

For this html:

<div class="outer">
     <div class="inner"></div>
</div>

This selector should work:

$('.outer > .inner')

Ignore Duplicates and Create New List of Unique Values in Excel

I have a list of color names in range A2:A8, in column B I want to extract a distinct list of color names.

Follow the below given steps:

  • Select the Cell B2; write the formula to retrieve the unique values from a list.
  • =IF(COUNTIF(A$2:A2,A2)=1,A2,””)
  • Press Enter on your keyboard.
  • The function will return the name of the first color.
  • To return the value for the rest of cells, copy the same formula down. To copy formula in range B3:B8, copy the formula in cell B2 by pressing the key CTRL+C on your keyboard and paste in the range B3:B8 by pressing the key CTRL+V.
  • Here you can see the output where we have the unique list of color names.

How do I tell if .NET 3.5 SP1 is installed?

Look at HKLM\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5\. One of these must be true:

  • The Version value in that key should be 3.5.30729.01
  • Or the SP value in the same key should be 1

In C# (taken from the first comment), you could do something along these lines:

const string name = @"SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5";
RegistryKey subKey = Registry.LocalMachine.OpenSubKey(name);
var version = subKey.GetValue("Version").ToString();
var servicePack = subKey.GetValue("SP").ToString();

Iterate through a C++ Vector using a 'for' loop

If you use

std::vector<std::reference_wrapper<std::string>> names{ };

Do not forget, when you use auto in the for loop, to use also get, like this:

for (auto element in : names)
{
    element.get()//do something
}

How to avoid mysql 'Deadlock found when trying to get lock; try restarting transaction'

I have a method, the internals of which are wrapped in a MySqlTransaction.

The deadlock issue showed up for me when I ran the same method in parallel with itself.

There was not an issue running a single instance of the method.

When I removed MySqlTransaction, I was able to run the method in parallel with itself with no issues.

Just sharing my experience, I'm not advocating anything.

How does the keyword "use" work in PHP and can I import classes with it?

You'll have to include/require the class anyway, otherwise PHP won't know about the namespace.
You don't necessary have to do it in the same file though. You can do it in a bootstrap file for example. (or use an autoloader, but that's not the topic actually)

How do I clone a subdirectory only of a Git repository?

What you are trying to do is called a sparse checkout, and that feature was added in git 1.7.0 (Feb. 2012). The steps to do a sparse clone are as follows:

mkdir <repo>
cd <repo>
git init
git remote add -f origin <url>

This creates an empty repository with your remote, and fetches all objects but doesn't check them out. Then do:

git config core.sparseCheckout true

Now you need to define which files/folders you want to actually check out. This is done by listing them in .git/info/sparse-checkout, eg:

echo "some/dir/" >> .git/info/sparse-checkout
echo "another/sub/tree" >> .git/info/sparse-checkout

Last but not least, update your empty repo with the state from the remote:

git pull origin master

You will now have files "checked out" for some/dir and another/sub/tree on your file system (with those paths still), and no other paths present.

You might want to have a look at the extended tutorial and you should probably read the official documentation for sparse checkout.

As a function:

function git_sparse_clone() (
  rurl="$1" localdir="$2" && shift 2

  mkdir -p "$localdir"
  cd "$localdir"

  git init
  git remote add -f origin "$rurl"

  git config core.sparseCheckout true

  # Loops over remaining args
  for i; do
    echo "$i" >> .git/info/sparse-checkout
  done

  git pull origin master
)

Usage:

git_sparse_clone "http://github.com/tj/n" "./local/location" "/bin"

Note that this will still download the whole repository from the server – only the checkout is reduced in size. At the moment it is not possible to clone only a single directory. But if you don't need the history of the repository, you can at least save on bandwidth by creating a shallow clone. See udondan's answer below for information on how to combine shallow clone and sparse checkout.


As of git 2.25.0 (Jan 2020) an experimental sparse-checkout command is added in git:

git sparse-checkout init
# same as: 
# git config core.sparseCheckout true

git sparse-checkout set "A/B"
# same as:
# echo "A/B" >> .git/info/sparse-checkout

git sparse-checkout list
# same as:
# cat .git/info/sparse-checkout

fatal error LNK1104: cannot open file 'kernel32.lib'

Check the VC++ directories, in VS 2010 these can be found in your project properties. Check whether $(WindowsSdkDir)\lib is included in the directories list, if not, manually add it. If you're building for X64 platform, you should select X64 from the “Platform” ComboBox, and make sure that $(WindowsSdkDir)\lib\x64 is included in the directories list.

Changing the JFrame title

If your class extends JFrame then use this.setTitle(newTitle.getText());

If not and it contains a JFrame let's say named myFrame, then use myFrame.setTitle(newTitle.getText());

Now that you have posted your program, it is obvious that you need only one JTextField to get the new title. These changes will do the trick:

JTextField poolLengthText, poolWidthText, poolDepthText, poolVolumeText, hotTub,
        hotTubLengthText, hotTubWidthText, hotTubDepthText, hotTubVolumeText, temp, results,
        newTitle;

and:

    public void createOptions()
    {
        options = new JPanel();
        options.setLayout(null);
        JLabel labelOptions = new JLabel("Change Company Name:");
        labelOptions.setBounds(120, 10, 150, 20);
        options.add(labelOptions);
        newTitle = new JTextField("Some Title");
        newTitle.setBounds(80, 40, 225, 20);
        options.add(newTitle);
//        myTitle = new JTextField("My Title...");
//        myTitle.setBounds(80, 40, 225, 20);
//        myTitle.add(labelOptions);
        JButton newName = new JButton("Set New Name");
        newName.setBounds(60, 80, 150, 20);
        newName.addActionListener(this);
        options.add(newName);
        JButton Exit = new JButton("Exit");
        Exit.setBounds(250, 80, 80, 20);
        Exit.addActionListener(this);
        options.add(Exit);
    }

and:

private void New_Name()
{
    this.setTitle(newTitle.getText());
}

How to use variables in a command in sed?

Say:

sed "s|\$ROOT|${HOME}|" abc.sh

Note:

  • Use double quotes so that the shell would expand variables.
  • Use a separator different than / since the replacement contains /
  • Escape the $ in the pattern since you don't want to expand it.

EDIT: In order to replace all occurrences of $ROOT, say

sed "s|\$ROOT|${HOME}|g" abc.sh

How to open select file dialog via js?

For the sake of completeness, Ron van der Heijden's solution in pure JavaScript:

<button onclick="document.querySelector('.inputFile').click();">Select File ...</button>
<input class="inputFile" type="file" style="display: none;">

Why is Github asking for username/password when following the instructions on screen and pushing a new repo?

Improving upon @Ianl's answer,

It seems that if 2-step authentication is enabled, you have to use token instead of password. You could generate a token here.

If you want to disable the prompts for both the username and password then you can set the URL as follows -

git remote set-url origin https://username:[email protected]/WEMP/project-slideshow.git

Note that the URL has both the username and password. Also the .git/config file should show your current settings.


Update 20200128:

If you don't want to store the password in the config file, then you can generate your personal token and replace the password with the token. Here are some details.

It would look like this -

git remote set-url origin https://username:[email protected]/WEMP/project-slideshow.git

How to cast Object to its actual type?

I don't think you can (not without reflection), you should provide a type to your function as well:

void MyMethod(Object obj, Type t)
{
    var convertedObject = Convert.ChangeType(obj, t);
    ...
}

UPD:

This may work for you:

void MyMethod(Object obj)
{
    if (obj is A)
    {
        A a = obj as A;
        ...
    } 
    else if (obj is B)
    {
        B b = obj as B;
        ...
    }
}

jQuery - If element has class do this

First, you're missing some parentheses in your conditional:

if ($("#about").hasClass("opened")) {
  $("#about").animate({right: "-700px"}, 2000);
}

But you can also simplify this to:

$('#about.opened').animate(...);

If #about doesn't have the opened class, it won't animate.

If the problem is with the animation itself, we'd need to know more about your element positioning (absolute? absolute inside relative parent? does the parent have layout?)

Need to get current timestamp in Java

Joda-Time

Here is the same kind of code but using the third-party library Joda-Time 2.3.

In real life, I would specify a time zone, as relying on default zone is usually a bad practice. But omitted here for simplicity of example.

org.joda.time.DateTime now = new DateTime();
org.joda.time.format.DateTimeFormatter formatter = DateTimeFormat.forPattern( "MM/dd/yyyy h:mm:ss a" );
String nowAsString = formatter.print( now );

System.out.println( "nowAsString: " + nowAsString );

When run…

nowAsString: 11/28/2013 11:28:15 PM

Display rows with one or more NaN values in pandas dataframe

Can try this too, almost similar previous answers.

    d = {'filename': ['M66_MI_NSRh35d32kpoints.dat', 'F71_sMI_DMRI51d.dat', 'F62_sMI_St22d7.dat', 'F41_Car_HOC498d.dat', 'F78_MI_547d.dat'], 'alpha1': [0.8016, 0.0, 1.721, 1.167, 1.897], 'alpha2': [0.9283, 0.0, 3.833, 2.809, 5.459], 'gamma1': [1.0, np.nan, 0.23748000000000002, 0.36419, 0.095319], 'gamma2': [0.074804, 0.0, 0.15, 0.3, np.nan], 'chi2min': [39.855990000000006, 1e+25, 10.91832, 7.966335000000001, 25.93468]}
    df = pd.DataFrame(d).set_index('filename')

enter image description here

Count of null values in each column.

df.isnull().sum()

enter image description here

df.isnull().any(axis=1)

enter image description here

Find a file by name in Visual Studio Code

It's Ctrl+Shift+O / Cmd+Shift+O on mac. You can see it if you close all tabs

How do I get next month date from today's date and insert it in my database?

This function returns any correct number of months positively or negatively. Found in the comment section here:

function addMonthsToTime($numMonths = 1, $timeStamp = null){
    $timeStamp === null and $timeStamp = time();//Default to the present
    $newMonthNumDays =  date('d',strtotime('last day of '.$numMonths.' months', $timeStamp));//Number of days in the new month
    $currentDayOfMonth = date('d',$timeStamp);

    if($currentDayOfMonth > $newMonthNumDays){
      $newTimeStamp = strtotime('-'.($currentDayOfMonth - $newMonthNumDays).' days '.$numMonths.' months', $timeStamp);
    } else {
    $newTimeStamp = strtotime($numMonths.' months', $timeStamp);
    }

    return $newTimeStamp;
}

Create a string of variable length, filled with a repeated character

Unfortunately although the Array.join approach mentioned here is terse, it is about 10X slower than a string-concatenation-based implementation. It performs especially badly on large strings. See below for full performance details.

On Firefox, Chrome, Node.js MacOS, Node.js Ubuntu, and Safari, the fastest implementation I tested was:

function repeatChar(count, ch) {
    if (count == 0) {
        return "";
    }
    var count2 = count / 2;
    var result = ch;

    // double the input until it is long enough.
    while (result.length <= count2) {
        result += result;
    }
    // use substring to hit the precise length target without
    // using extra memory
    return result + result.substring(0, count - result.length);
};

This is verbose, so if you want a terse implementation you could go with the naive approach; it still performs betweeb 2X to 10X better than the Array.join approach, and is also faster than the doubling implementation for small inputs. Code:

// naive approach: simply add the letters one by one
function repeatChar(count, ch) {
    var txt = "";
    for (var i = 0; i < count; i++) {
        txt += ch;
    }
    return txt;
}

Further information:

Possible to iterate backwards through a foreach?

Sometimes you don't have the luxury of indexing, or perhaps you want to reverse the results of a Linq query, or maybe you don't want to modify the source collection, if any of these are true, Linq can help you.

A Linq extension method using anonymous types with Linq Select to provide a sorting key for Linq OrderByDescending;

    public static IEnumerable<T> Invert<T>(this IEnumerable<T> source)
    {
        var transform = source.Select(
            (o, i) => new
            {
                Index = i,
                Object = o
            });

        return transform.OrderByDescending(o => o.Index)
                        .Select(o => o.Object);
    }

Usage:

    var eable = new[]{ "a", "b", "c" };

    foreach(var o in eable.Invert())
    {
        Console.WriteLine(o);
    }

    // "c", "b", "a"

It is named "Invert" because it is synonymous with "Reverse" and enables disambiguation with the List Reverse implementation.

It is possible to reverse certain ranges of a collection too, since Int32.MinValue and Int32.MaxValue are out of the range of any kind of collection index, we can leverage them for the ordering process; if an element index is below the given range, it is assigned Int32.MaxValue so that its order doesn't change when using OrderByDescending, similarly, elements at an index greater than the given range, will be assigned Int32.MinValue, so that they appear to the end of the ordering process. All elements within the given range are assigned their normal index and are reversed accordingly.

    public static IEnumerable<T> Invert<T>(this IEnumerable<T> source, int index, int count)
    {
        var transform = source.Select(
            (o, i) => new
            {
                Index = i < index ? Int32.MaxValue : i >= index + count ? Int32.MinValue : i,
                Object = o
            });

        return transform.OrderByDescending(o => o.Index)
                        .Select(o => o.Object);
    }

Usage:

    var eable = new[]{ "a", "b", "c", "d" };

    foreach(var o in eable.Invert(1, 2))
    {
        Console.WriteLine(o);
    }

    // "a", "c", "b", "d"

I'm not sure of the performance hits of these Linq implementations versus using a temporary List to wrap a collection for reversing.


At time of writing, I was not aware of Linq's own Reverse implementation, still, it was fun working this out. https://msdn.microsoft.com/en-us/library/vstudio/bb358497(v=vs.100).aspx

Fatal error: Call to undefined function imap_open() in PHP

If your local installation is running XAMPP on Windows , That's enough : you can open the file "\xampp\php\php.ini" to activate the php exstension by removing the beginning semicolon at the line ";extension=php_imap.dll". It should be:

;extension=php_imap.dll

to

extension=php_imap.dll

How to get ID of clicked element with jQuery

First off you can't have just a number for your id unless you are using the HTML5 DOCTYPE. Secondly, you need to either remove the # in each id or replace it with this:

$container.cycle(id.replace('#','')); 

Get resultset from oracle stored procedure

Hi I know this was asked a while ago but I've just figured this out and it might help someone else. Not sure if this is exactly what you're looking for but this is how I call a stored proc and view the output using SQL Developer.
In SQL Developer when viewing the proc, right click and choose 'Run' or select Ctrl+F11 to bring up the Run PL/SQL window. This creates a template with the input and output params which you need to modify. My proc returns a sys_refcursor. The tricky part for me was declaring a row type that is exactly equivalent to the select stmt / sys_refcursor being returned by the proc:

DECLARE
  P_CAE_SEC_ID_N NUMBER;
  P_FM_SEC_CODE_C VARCHAR2(200);
  P_PAGE_INDEX NUMBER;
  P_PAGE_SIZE NUMBER;
  v_Return sys_refcursor;
  type t_row is record (CAE_SEC_ID NUMBER,FM_SEC_CODE VARCHAR2(7),rownum number, v_total_count number);
  v_rec t_row;

BEGIN
  P_CAE_SEC_ID_N := NULL;
  P_FM_SEC_CODE_C := NULL;
  P_PAGE_INDEX := 0;
  P_PAGE_SIZE := 25;

  CAE_FOF_SECURITY_PKG.GET_LIST_FOF_SECURITY(
    P_CAE_SEC_ID_N => P_CAE_SEC_ID_N,
    P_FM_SEC_CODE_C => P_FM_SEC_CODE_C,
    P_PAGE_INDEX => P_PAGE_INDEX,
    P_PAGE_SIZE => P_PAGE_SIZE,
    P_FOF_SEC_REFCUR => v_Return
  );
  -- Modify the code to output the variable
  -- DBMS_OUTPUT.PUT_LINE('P_FOF_SEC_REFCUR = ');
  loop
    fetch v_Return into v_rec;
    exit when v_Return%notfound;
    DBMS_OUTPUT.PUT_LINE('sec_id = ' || v_rec.CAE_SEC_ID || 'sec code = ' ||v_rec.FM_SEC_CODE);
  end loop;

END;

Alter column, add default constraint

Actually you have to Do Like below Example, which will help to Solve the Issue...

drop table ABC_table

create table ABC_table
(
    names varchar(20),
    age int
)

ALTER TABLE ABC_table
ADD CONSTRAINT MyConstraintName
DEFAULT 'This is not NULL' FOR names

insert into ABC(age) values(10)

select * from ABC

Regex allow a string to only contain numbers 0 - 9 and limit length to 45

codaddict has provided the right answer. As for what you've tried, I'll explain why they don't make the cut:

  • [0-9]{1,45} is almost there, however it matches a 1-to-45-digit string even if it occurs within another longer string containing other characters. Hence you need ^ and $ to restrict it to an exact match.

  • ^[0-9]{45}*$ matches an exactly-45-digit string, repeated 0 or any number of times (*). That means the length of the string can only be 0 or a multiple of 45 (90, 135, 180...).

SQL: How To Select Earliest Row

Simply use min()

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

Create a table without a header in Markdown

You may be able to hide a heading if you can add the following CSS:

<style>
    th {
        display: none;
    }
</style>

This is a bit heavy-handed and doesn’t distinguish between tables, but it may do for a simple task.

CertificateException: No name matching ssl.someUrl.de found

If you're looking for a Kafka error, this might because the upgrade of Kafka's version from 1.x to 2.x.

javax.net.ssl.SSLHandshakeException: General SSLEngine problem ... javax.net.ssl.SSLHandshakeException: General SSLEngine problem ... java.security.cert.CertificateException: No name matching *** found

or

[Producer clientId=producer-1] Connection to node -2 failed authentication due to: SSL handshake failed

The default value for ssl.endpoint.identification.algorithm was changed to https, which performs hostname verification (man-in-the-middle attacks are possible otherwise). Set ssl.endpoint.identification.algorithm to an empty string to restore the previous behaviour. Apache Kafka Notable changes in 2.0.0

Solution: SslConfigs.SSL_ENDPOINT_IDENTIFICATION_ALGORITHM_CONFIG, ""

How to embed new Youtube's live video permanent URL?

Here's how to do it in Squarespace using the embed block classes to create responsiveness.

Put this into a code block:

<div class="sqs-block embed-block sqs-block-embed" data-block-type="22" >
    <div class="sqs-block-content"><div class="intrinsic" style="max-width:100%">
        <div class="embed-block-wrapper embed-block-provider-YouTube" style="padding-bottom:56.20609%;">
            <iframe allow="autoplay; fullscreen" scrolling="no" data-image-dimensions="854x480" allowfullscreen="true" src="https://www.youtube.com/embed/live_stream?channel=CHANNEL_ID_HERE" width="854" data-embed="true" frameborder="0" title="YouTube embed" class="embedly-embed" height="480">
            </iframe>
        </div>
    </div>
</div>

Tweak however you'd like!

How do I set up HttpContent for my HttpClient PostAsync second parameter?

    public async Task<ActionResult> Index()
    {
        apiTable table = new apiTable();
        table.Name = "Asma Nadeem";
        table.Roll = "6655";

        string str = "";
        string str2 = "";

        HttpClient client = new HttpClient();

        string json = JsonConvert.SerializeObject(table);

        StringContent httpContent = new StringContent(json, System.Text.Encoding.UTF8, "application/json");

        var response = await client.PostAsync("http://YourSite.com/api/apiTables", httpContent);

        str = "" + response.Content + " : " + response.StatusCode;

        if (response.IsSuccessStatusCode)
        {       
            str2 = "Data Posted";
        }

        return View();
    }

Best way to track onchange as-you-type in input type="text"?

If you use ONLY Internet Explorer, you can use this:

<input type="text" id="myID" onpropertychange="TextChange(this)" />

<script type="text/javascript">
    function TextChange(tBox) {
        if(event.propertyName=='value') {
            //your code here
        }
    }
</script>

Hope that helps.

Add items in array angular 4

Yes there is a way to do it.

First declare a class.

//anyfile.ts
export class Custom
{
  name: string, 
  empoloyeeID: number
}

Then in your component import the class

import {Custom} from '../path/to/anyfile.ts'
.....
export class FormComponent implements OnInit {
 name: string;
 empoloyeeID : number;
 empList: Array<Custom> = [];
 constructor() {

 }

 ngOnInit() {
 }
 onEmpCreate(){
   //console.log(this.name,this.empoloyeeID);
   let customObj = new Custom();
   customObj.name = "something";
   customObj.employeeId = 12; 
   this.empList.push(customObj);
   this.name ="";
   this.empoloyeeID = 0; 
 }
}

Another way would be to interfaces read the documentation once - https://www.typescriptlang.org/docs/handbook/interfaces.html

Also checkout this question, it is very interesting - When to use Interface and Model in TypeScript / Angular2

What is the difference between putting a property on application.yml or bootstrap.yml in spring boot?

Another use for bootstrap.yml is to load configuration from kubernetes configmap and secret resources. The application must import the spring-cloud-starter-kubernetes dependency.

As with the Spring Cloud Config, this has to take place during the bootstrap phrase.

From the docs :

spring:
  application:
    name: cloud-k8s-app
  cloud:
    kubernetes:
      config:
        name: default-name
        namespace: default-namespace
        sources:
         # Spring Cloud Kubernetes looks up a ConfigMap named c1 in namespace default-namespace
         - name: c1

So properties stored in the configmap resource with meta.name default-name can be referenced just the same as properties in application.yml

And the same process applies to secrets :

spring:
  application:
    name: cloud-k8s-app
  cloud:
    kubernetes:
      secrets:
        name: default-name
        namespace: default-namespace
        sources:
         # Spring Cloud Kubernetes looks up a Secret named s1 in namespace default-namespace
         - name: s1

Can I call jQuery's click() to follow an <a> link if I haven't bound an event handler to it with bind or click already?

JavaScript/jQuery doesn't support the default behavior of links "clicked" programmatically.

Instead, you can create a form and submit it. This way you don't have to use window.location or window.open, which are often blocked as unwanted popups by browsers.

This script has two different methods: one that tries to open three new tabs/windows (it opens only one in Internet Explorer and Chrome, more information is below) and one that fires a custom event on a link click.

Here is how:

HTML

<html>
<head>
    <script src="jquery-1.9.1.min.js" type="text/javascript"></script>
    <script src="script.js" type="text/javascript"></script>
</head>

<body>
    <button id="testbtn">Test</button><br><br>

    <a href="https://google.nl">Google</a><br>
    <a href="http://en.wikipedia.org/wiki/Main_Page">Wikipedia</a><br>
    <a href="https://stackoverflow.com/">Stack Overflow</a>
</body>

</html>

jQuery (file script.js)

$(function()
{
    // Try to open all three links by pressing the button
    // - Firefox opens all three links
    // - Chrome only opens one of them without a popup warning
    // - Internet Explorer only opens one of them WITH a popup warning
    $("#testbtn").on("click", function()
    {
        $("a").each(function()
        {
            var form = $("<form></form>");
            form.attr(
            {
                id     : "formform",
                action : $(this).attr("href"),
                method : "GET",
                // Open in new window/tab
                target : "_blank"
            });

            $("body").append(form);
            $("#formform").submit();
            $("#formform").remove();
        });
    });

    // Or click the link and fire a custom event
    // (open your own window without following 
    // the link itself)
    $("a").on("click", function()
    {
        var form = $("<form></form>");
        form.attr(
        {
            id     : "formform",
            // The location given in the link itself
            action : $(this).attr("href"),
            method : "GET",
            // Open in new window/tab
            target : "_blank"
        });

        $("body").append(form);
        $("#formform").submit();
        $("#formform").remove();

        // Prevent the link from opening normally
        return false;
    });
});

For each link element, it:

  1. Creates a form
  2. Gives it attributes
  3. Appends it to the DOM so it can be submitted
  4. Submits it
  5. Removes the form from the DOM, removing all traces *Insert evil laugh*

Now you have a new tab/window loading "https://google.nl" (or any URL you want, just replace it). Unfortunately when you try to open more than one window this way, you get an Popup blocked messagebar when trying to open the second one (the first one is still opened).


More information on how I got to this method is found here:

Python SQLite: database is locked

in my case ,the error happened when a lot of concurrent process trying to read/write to the same table. I used retry to workaround the issue

def _retry_if_exception(exception):
    return isinstance(exception, Exception)

@retry(retry_on_exception=_retry_if_exception,
       wait_random_min=1000,
       wait_random_max=5000,
       stop_max_attempt_number=5)
def execute(cmd, commit=True):
   c.execute(cmd)
   c.conn.commit()

How to use select/option/NgFor on an array of objects in Angular2

I don't know what things were like in the alpha, but I'm using beta 12 right now and this works fine. If you have an array of objects, create a select like this:

<select [(ngModel)]="simpleValue"> // value is a string or number
    <option *ngFor="let obj of objArray" [value]="obj.value">{{obj.name}}</option>
</select>

If you want to match on the actual object, I'd do it like this:

<select [(ngModel)]="objValue"> // value is an object
    <option *ngFor="let obj of objArray" [ngValue]="obj">{{obj.name}}</option>
</select>

How to get current date in 'YYYY-MM-DD' format in ASP.NET?

var formatedDate = DateTime.Now.ToString("yyyy-MM-dd",System.Globalization.CultureInfo.InvariantCulture);

To ensure the user's local settings don't affect it

Simple 3x3 matrix inverse code (C++)

#include <iostream>
using namespace std;

int main()
{
    double A11, A12, A13;
    double A21, A22, A23;
    double A31, A32, A33;

    double B11, B12, B13;
    double B21, B22, B23;
    double B31, B32, B33;

    cout << "Enter all number from left to right, from top to bottom, and press enter after every number: ";
    cin  >> A11;
    cin  >> A12;
    cin  >> A13;
    cin  >> A21;
    cin  >> A22;
    cin  >> A23;
    cin  >> A31;
    cin  >> A32;
    cin  >> A33;

    B11 = 1 / ((A22 * A33) - (A23 * A32));
    B12 = 1 / ((A13 * A32) - (A12 * A33));
    B13 = 1 / ((A12 * A23) - (A13 * A22));
    B21 = 1 / ((A23 * A31) - (A21 * A33));
    B22 = 1 / ((A11 * A33) - (A13 * A31));
    B23 = 1 / ((A13 * A21) - (A11 * A23));
    B31 = 1 / ((A21 * A32) - (A22 * A31));
    B32 = 1 / ((A12 * A31) - (A11 * A32));
    B33 = 1 / ((A11 * A22) - (A12 * A21));

    cout << B11 << "\t" << B12 << "\t" << B13 << endl;
    cout << B21 << "\t" << B22 << "\t" << B23 << endl;
    cout << B31 << "\t" << B32 << "\t" << B33 << endl;

    return 0;
}

How to set the image from drawable dynamically in android?

imageview= (ImageView)findViewById(R.id.imageView);
imageview.setImageResource(R.drawable.mydrawable);

how to cancel/abort ajax request in axios

Using useEffect hook:

useEffect(() => {
  const ourRequest = Axios.CancelToken.source() // <-- 1st step

  const fetchPost = async () => {
    try {
      const response = await Axios.get(`endpointURL`, {
        cancelToken: ourRequest.token, // <-- 2nd step
      })
      console.log(response.data)
      setPost(response.data)
      setIsLoading(false)
    } catch (err) {
      console.log('There was a problem or request was cancelled.')
    }
  }
  fetchPost()

  return () => {
    ourRequest.cancel() // <-- 3rd step
  }
}, [])

Note: For POST request, pass cancelToken as 3rd argument

Axios.post(`endpointURL`, {data}, {
 cancelToken: ourRequest.token, // 2nd step
})

Python reading from a file and saving to utf-8

You can't do that using open. use codecs.

when you are opening a file in python using the open built-in function you will always read/write the file in ascii. To write it in utf-8 try this:

import codecs
file = codecs.open('data.txt','w','utf-8')

How can I get screen resolution in java?

You can get the screen size with the Toolkit.getScreenSize() method.

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
double width = screenSize.getWidth();
double height = screenSize.getHeight();

On a multi-monitor configuration you should use this :

GraphicsDevice gd = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
int width = gd.getDisplayMode().getWidth();
int height = gd.getDisplayMode().getHeight();

If you want to get the screen resolution in DPI you'll have to use the getScreenResolution() method on Toolkit.


Resources :

Split string using a newline delimiter with Python

If you want to split only by newlines, you can use str.splitlines():

Example:

>>> data = """a,b,c
... d,e,f
... g,h,i
... j,k,l"""
>>> data
'a,b,c\nd,e,f\ng,h,i\nj,k,l'
>>> data.splitlines()
['a,b,c', 'd,e,f', 'g,h,i', 'j,k,l']

With str.split() your case also works:

>>> data = """a,b,c
... d,e,f
... g,h,i
... j,k,l"""
>>> data
'a,b,c\nd,e,f\ng,h,i\nj,k,l'
>>> data.split()
['a,b,c', 'd,e,f', 'g,h,i', 'j,k,l']

However if you have spaces (or tabs) it will fail:

>>> data = """
... a, eqw, qwe
... v, ewr, err
... """
>>> data
'\na, eqw, qwe\nv, ewr, err\n'
>>> data.split()
['a,', 'eqw,', 'qwe', 'v,', 'ewr,', 'err']

TCPDF not render all CSS properties

I found this:

// Remove tag bottom and top margins

$tagvs = array( 'p' => array( 
                              0 => array('h' => 0, 'n' => 0), 
                              1 => array('h' => 0, 'n' => 0)
                             ) 
              );
$pdf->setHtmlVSpace($tagvs);

in here: https://tcpdf.org/examples/example_061/

Use it to remove 'p' tags properties (bottom and top), then position the 'p' text inside a cell.

How to unpackage and repackage a WAR file

Non programmatically, you can just open the archive using the 7zip UI to add/remove or extract/replace files without the structure changing. I didn't know it was a problem using other things until now :)

What is a NullPointerException, and how do I fix it?

It's like you are trying to access an object which is null. Consider below example:

TypeA objA;

At this time you have just declared this object but not initialized or instantiated. And whenever you try to access any property or method in it, it will throw NullPointerException which makes sense.

See this below example as well:

String a = null;
System.out.println(a.toString()); // NullPointerException will be thrown

Add IIS 7 AppPool Identities as SQL Server Logons

If you're going across machines, you either need to be using NETWORK SERVICE, LOCAL SYSTEM, a domain account, or a SQL 2008 R2 (if you have it) Managed Service Account (which is my preference if you had such an infrastructure). You can not use an account which is not visible to the Active Directory domain.

Batch script to install MSI

Although it might look out of topic nobody bothered to check the ERRORLEVEL. When I used your suggestions I tried to check for errors straight after the MSI installation. I made it fail on purpose and noticed that on the command line all works beautifully whilst in a batch file msiexec dosn't seem to set errors. Tried different things there like

  • Using start /wait
  • Using !ERRORLEVEL! variable instead of %ERRORLEVEL%
  • Using SetLocal EnableDelayedExpansion

Nothing works and what mostly annoys me it's the fact that it works in the command line.

Options for initializing a string array

Basic:

string[] myString = new string[]{"string1", "string2"};

or

string[] myString = new string[4];
myString[0] = "string1"; // etc.

Advanced: From a List

list<string> = new list<string>(); 
//... read this in from somewhere
string[] myString = list.ToArray();

From StringCollection

StringCollection sc = new StringCollection();
/// read in from file or something
string[] myString = sc.ToArray();

What does a circled plus mean?

This is not an plus, but the sign for the binary operator XOR

a   b   a XOR b
0   0   0
0   1   1
1   0   1
1   1   0

java how to use classes in other package?

Given your example, you need to add the following import in your main.main class:

import second.second;

Some bonus advice, make sure you titlecase your class names as that is a Java standard. So your example Main class will have the structure:

package main;  //lowercase package names
public class Main //titlecase class names
{
    //Main class content
}

Use LINQ to get items in one List<>, that are not in another List<>

Bit late to the party but a good solution which is also Linq to SQL compatible is:

List<string> list1 = new List<string>() { "1", "2", "3" };
List<string> list2 = new List<string>() { "2", "4" };

List<string> inList1ButNotList2 = (from o in list1
                                   join p in list2 on o equals p into t
                                   from od in t.DefaultIfEmpty()
                                   where od == null
                                   select o).ToList<string>();

List<string> inList2ButNotList1 = (from o in list2
                                   join p in list1 on o equals p into t
                                   from od in t.DefaultIfEmpty()
                                   where od == null
                                   select o).ToList<string>();

List<string> inBoth = (from o in list1
                       join p in list2 on o equals p into t
                       from od in t.DefaultIfEmpty()
                       where od != null
                       select od).ToList<string>();

Kudos to http://www.dotnet-tricks.com/Tutorial/linq/UXPF181012-SQL-Joins-with-C

How to sum up an array of integers in C#

One problem with the for loop solutions above is that for the following input array with all positive values, the sum result is negative:

int[] arr = new int[] { Int32.MaxValue, 1 };
int sum = 0;
for (int i = 0; i < arr.Length; i++)
{
    sum += arr[i];
}
Console.WriteLine(sum);

The sum is -2147483648, as the positive result is too big for the int data type and overflows into a negative value.

For the same input array the arr.Sum() suggestions cause an overflow exception to be thrown.

A more robust solution is to use a larger data type, such as a "long" in this case, for the "sum" as follows:

int[] arr = new int[] { Int32.MaxValue, 1 };
long sum = 0;
for (int i = 0; i < arr.Length; i++)
{
    sum += arr[i];
}

The same improvement works for summation of other integer data types, such as short, and sbyte. For arrays of unsigned integer data types such as uint, ushort and byte, using an unsigned long (ulong) for the sum avoids the overflow exception.

The for loop solution is also many times faster than Linq .Sum()

To run even faster, HPCsharp nuget package implements all of these .Sum() versions as well as SIMD/SSE versions and multi-core parallel ones, for many times faster performance.

Creating CSS Global Variables : Stylesheet theme management

You can't create variables in CSS right now. If you want this sort of functionality you will need to use a CSS preprocessor like SASS or LESS. Here are your styles as they would appear in SASS:

$Color1:#fff;
$Color2:#b00;
$Color3:#050;

h1 {
    color:$Color1;
    background:$Color2;
}

They also allow you to do other (awesome) things like nesting selectors:

#some-id {
    color:red;

    &:hover {
        cursor:pointer;
    }
}

This would compile to:

#some-id { color:red; }
#some-id:hover { cursor:pointer; }

Check out the official SASS tutorial for setup instructions and more on syntax/features. Personally I use a Visual Studio extension called Web Workbench by Mindscape for easy developing, there are a lot of plugins for other IDEs as well.

Update

As of July/August 2014, Firefox has implemented the draft spec for CSS variables, here is the syntax:

:root {
  --main-color: #06c;
  --accent-color: #006;
}
/* The rest of the CSS file */
#foo h1 {
  color: var(--main-color);
}

Calling filter returns <filter object at ... >

It looks like you're using python 3.x. In python3, filter, map, zip, etc return an object which is iterable, but not a list. In other words,

filter(func,data) #python 2.x

is equivalent to:

list(filter(func,data)) #python 3.x

I think it was changed because you (often) want to do the filtering in a lazy sense -- You don't need to consume all of the memory to create a list up front, as long as the iterator returns the same thing a list would during iteration.

If you're familiar with list comprehensions and generator expressions, the above filter is now (almost) equivalent to the following in python3.x:

( x for x in data if func(x) ) 

As opposed to:

[ x for x in data if func(x) ]

in python 2.x

Number of occurrences of a character in a string

Why use regex for that. String implements IEnumerable<char>, so you can just use LINQ.

test.Count(c => c == '&')

What is a Windows Handle?

So at the most basic level a HANDLE of any sort is a pointer to a pointer or

#define HANDLE void **

Now as to why you would want to use it

Lets take a setup:

class Object{
   int Value;
}

class LargeObj{

   char * val;
   LargeObj()
   {
      val = malloc(2048 * 1000);
   }

}

void foo(Object bar){
    LargeObj lo = new LargeObj();
    bar.Value++;
}

void main()
{
   Object obj = new Object();
   obj.val = 1;
   foo(obj);
   printf("%d", obj.val);
}

So because obj was passed by value (make a copy and give that to the function) to foo, the printf will print the original value of 1.

Now if we update foo to:

void foo(Object * bar)
{
    LargeObj lo = new LargeObj();
    bar->val++;
}

There is a chance that the printf will print the updated value of 2. But there is also the possibility that foo will cause some form of memory corruption or exception.

The reason is this while you are now using a pointer to pass obj to the function you are also allocating 2 Megs of memory, this could cause the OS to move the memory around updating the location of obj. Since you have passed the pointer by value, if obj gets moved then the OS updates the pointer but not the copy in the function and potentially causing problems.

A final update to foo of:

void foo(Object **bar){
    LargeObj lo = LargeObj();
    Object * b = &bar;
    b->val++;
}

This will always print the updated value.

See, when the compiler allocates memory for pointers it marks them as immovable, so any re-shuffling of memory caused by the large object being allocated the value passed to the function will point to the correct address to find out the final location in memory to update.

Any particular types of HANDLEs (hWnd, FILE, etc) are domain specific and point to a certain type of structure to protect against memory corruption.

Jenkins CI Pipeline Scripts not permitted to use method groovy.lang.GroovyObject

Quickfix

I had similar issue and I resolved it doing the following

  1. Navigate to jenkins > Manage jenkins > In-process Script Approval
  2. There was a pending command, which I had to approve.

In process approval link in Jenkins 2.61 Alternative 1: Disable sandbox

As this article explains in depth, groovy scripts are run in sandbox mode by default. This means that a subset of groovy methods are allowed to run without administrator approval. It's also possible to run scripts not in sandbox mode, which implies that the whole script needs to be approved by an administrator at once. This preventing users from approving each line at the time.

Running scripts without sandbox can be done by unchecking this checkbox in your project config just below your script: enter image description here

Alternative 2: Disable script security

As this article explains it also possible to disable script security completely. First install the permissive script security plugin and after that change your jenkins.xml file add this argument:

-Dpermissive-script-security.enabled=true

So you jenkins.xml will look something like this:

<executable>..bin\java</executable>
<arguments>-Dpermissive-script-security.enabled=true -Xrs -Xmx4096m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle -jar "%BASE%\jenkins.war" --httpPort=80 --webroot="%BASE%\war"</arguments>

Make sure you know what you are doing if you implement this!

What is the difference between field, variable, attribute, and property in Java POJOs?

The difference between a variable, field, attribute, and property in Java:

A variable is the name given to a memory location. It is the basic unit of storage in a program.

A field is a data member of a class. Unless specified otherwise, a field can be public, static, not static and final.

An attribute is another term for a field. It’s typically a public field that can be accessed directly.

  • In NetBeans or Eclipse, when we type object of a class and after that dot(.) they give some suggestion which are called Attributes.

A property is a term used for fields, but it typically has getter and setter combination.

SSIS how to set connection string dynamically from a config file

Some options:

  1. You can use the Execute Package Utility to change your datasource, before running the package.

  2. You can run your package using DTEXEC, and change your connection by passing in a /CONNECTION parameter. Probably save it as a batch so next time you don't need to type the whole thing and just change the datasource as required.

  3. You can use the SSIS XML package configuration file. Here is a walk through.

  4. You can save your configrations in a database table.

Remove Primary Key in MySQL

One Line:

ALTER TABLE  `user_customer_permission` DROP PRIMARY KEY , ADD PRIMARY KEY (  `id` )

You will also not lose the auto-increment and have to re-add it which could have side-effects.

Convert Mat to Array/Vector in OpenCV

You can use iterators:

Mat matrix = ...;

std::vector<float> vec(matrix.begin<float>(), matrix.end<float>());

Returning an array using C

How about this deliciously evil implementation?

array.h

#define IMPORT_ARRAY(TYPE)    \
    \
struct TYPE##Array {    \
    TYPE* contents;    \
    size_t size;    \
};    \
    \
struct TYPE##Array new_##TYPE##Array() {    \
    struct TYPE##Array a;    \
    a.contents = NULL;    \
    a.size = 0;    \
    return a;    \
}    \
    \
void array_add(struct TYPE##Array* o, TYPE value) {    \
    TYPE* a = malloc((o->size + 1) * sizeof(TYPE));    \
    TYPE i;    \
    for(i = 0; i < o->size; ++i) {    \
        a[i] = o->contents[i];    \
    }    \
    ++(o->size);    \
    a[o->size - 1] = value;    \
    free(o->contents);    \
    o->contents = a;    \
}    \
void array_destroy(struct TYPE##Array* o) {    \
    free(o->contents);    \
}    \
TYPE* array_begin(struct TYPE##Array* o) {    \
    return o->contents;    \
}    \
TYPE* array_end(struct TYPE##Array* o) {    \
    return o->contents + o->size;    \
}

main.c

#include <stdlib.h>
#include "array.h"

IMPORT_ARRAY(int);

struct intArray return_an_array() {
    struct intArray a;
    a = new_intArray();
    array_add(&a, 1);
    array_add(&a, 2);
    array_add(&a, 3);
    return a;
}

int main() {
    struct intArray a;
    int* it;
    int* begin;
    int* end;
    a = return_an_array();
    begin = array_begin(&a);
    end = array_end(&a);
    for(it = begin; it != end; ++it) {
        printf("%d ", *it);
    }
    array_destroy(&a);
    getchar();
    return 0;
}

How to access iOS simulator camera

Simulator doesn't have a Camera. If you want to access a camera you need a device. You can't test camera on simulator. You can only check the photo and video gallery.

Capturing "Delete" Keypress with jQuery

Javascript Keycodes

  • e.keyCode == 8 for backspace
  • e.keyCode == 46 for forward backspace or delete button in PC's

Except this detail Colin & Tod's answer is working.

PHP Fatal error: Class 'PDO' not found

This can also happen if there is a php.ini file in the web app's current working directory. If one has been placed there to change certain settings, it will override the global one.

To avoid this problem, don't use a php.ini file to change settings; instead you can:

  • Specify settings in the vhost declaration
  • Use an .htaccess file with php_flag (see here)
  • Use an .user.ini file (see here)

How to yum install Node.JS on Amazon Linux

As mentioned in official documentation , simple below 2 steps -

curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
sudo apt-get install -y nodejs

How to make html table vertically scrollable

Just add the display:block to the thead > tr and tbody. check the below example

http://www.imaputz.com/cssStuff/bigFourVersion.html

Bash script to check running process

A solution with service and awk that takes in a comma-delimited list of service names.

First it's probably a good bet you'll need root privileges to do what you want. If you don't need to check then you can remove that part.

#!/usr/bin/env bash

# First parameter is a comma-delimited string of service names i.e. service1,service2,service3
SERVICES=$1

ALL_SERVICES_STARTED=true

if [ $EUID -ne 0 ]; then
  if [ "$(id -u)" != "0" ]; then
    echo "root privileges are required" 1>&2
    exit 1
  fi
  exit 1
fi

for service in ${SERVICES//,/ }
do
    STATUS=$(service ${service} status | awk '{print $2}')

    if [ "${STATUS}" != "started" ]; then
        echo "${service} not started"
        ALL_SERVICES_STARTED=false
    fi
done

if ${ALL_SERVICES_STARTED} ; then
    echo "All services started"
    exit 0
else
    echo "Check Failed"
    exit 1
fi

Laravel 5 error SQLSTATE[HY000] [1045] Access denied for user 'homestead'@'localhost' (using password: YES)

Match the .env file and the config.php file with your username and password and your hostname in the database settings.if they are not equal,relation will not connect.

Get file name from URL

I've found that some urls when passed directly to FilenameUtils.getName return unwanted results and this needs to be wrapped up to avoid exploits.

For example,

System.out.println(FilenameUtils.getName("http://www.google.com/.."));

returns

..

which I doubt anyone wants to allow.

The following function seems to work fine, and shows some of these test cases, and it returns null when the filename can't be determined.

public static String getFilenameFromUrl(String url)
{
    if (url == null)
        return null;
    
    try
    {
        // Add a protocol if none found
        if (! url.contains("//"))
            url = "http://" + url;

        URL uri = new URL(url);
        String result = FilenameUtils.getName(uri.getPath());

        if (result == null || result.isEmpty())
            return null;

        if (result.contains(".."))
            return null;

        return result;
    }
    catch (MalformedURLException e)
    {
        return null;
    }
}

This is wrapped up with some simple tests cases in the following example:

import java.util.Objects;
import java.net.URL;
import org.apache.commons.io.FilenameUtils;

class Main {

  public static void main(String[] args) {
    validateFilename(null, null);
    validateFilename("", null);
    validateFilename("www.google.com/../me/you?trex=5#sdf", "you");
    validateFilename("www.google.com/../me/you?trex=5 is the num#sdf", "you");
    validateFilename("http://www.google.com/test.png?test", "test.png");
    validateFilename("http://www.google.com", null);
    validateFilename("http://www.google.com#test", null);
    validateFilename("http://www.google.com////", null);
    validateFilename("www.google.com/..", null);
    validateFilename("http://www.google.com/..", null);
    validateFilename("http://www.google.com/test", "test");
    validateFilename("https://www.google.com/../../test.png", "test.png");
    validateFilename("file://www.google.com/test.png", "test.png");
    validateFilename("file://www.google.com/../me/you?trex=5", "you");
    validateFilename("file://www.google.com/../me/you?trex", "you");
  }

  private static void validateFilename(String url, String expectedFilename){
    String actualFilename = getFilenameFromUrl(url);

    System.out.println("");
    System.out.println("url:" + url);
    System.out.println("filename:" + expectedFilename);

    if (! Objects.equals(actualFilename, expectedFilename))
      throw new RuntimeException("Problem, actual=" + actualFilename + " and expected=" + expectedFilename + " are not equal");
  }

  public static String getFilenameFromUrl(String url)
  {
    if (url == null)
      return null;

    try
    {
      // Add a protocol if none found
      if (! url.contains("//"))
        url = "http://" + url;

      URL uri = new URL(url);
      String result = FilenameUtils.getName(uri.getPath());

      if (result == null || result.isEmpty())
        return null;

      if (result.contains(".."))
        return null;

      return result;
    }
    catch (MalformedURLException e)
    {
      return null;
    }
  }
}

If...Then...Else with multiple statements after Then

This works with multiple statements:

if condition1 Then stmt1:stmt2 Else if condition2 Then stmt3:stmt4 Else stmt5:stmt6

Or you can split it over multiple lines:

if condition1 Then stmt1:stmt2
Else if condition2 Then stmt3:stmt4
Else stmt5:stmt6

Python, remove all non-alphabet chars from string

Use re.sub

import re

regex = re.compile('[^a-zA-Z]')
#First parameter is the replacement, second parameter is your input string
regex.sub('', 'ab3d*E')
#Out: 'abdE'

Alternatively, if you only want to remove a certain set of characters (as an apostrophe might be okay in your input...)

regex = re.compile('[,\.!?]') #etc.

Display all views on oracle database

for all views (you need dba privileges for this query)

select view_name from dba_views

for all accessible views (accessible by logged user)

select view_name from all_views

for views owned by logged user

select view_name from user_views

Using member variable in lambda capture list inside a member function

Summary of the alternatives:

capture this:

auto lambda = [this](){};

use a local reference to the member:

auto& tmp = grid;
auto lambda = [ tmp](){}; // capture grid by (a single) copy
auto lambda = [&tmp](){}; // capture grid by ref

C++14:

auto lambda = [ grid = grid](){}; // capture grid by copy
auto lambda = [&grid = grid](){}; // capture grid by ref

example: https://godbolt.org/g/dEKVGD

Convert digits into words with JavaScript

 var units = ["", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
var tens = ["", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"];



function convert7digitIntoWords(num) {
    var remainder = num % 1000000
    var hun = num - remainder;
    var div = Math.floor(num / 100000);
    if (remainder !== 0)
        return (convert2digitIntoWords(div) + " lakhs " + convert5digitIntoWords(remainder % 100000))
    else
        return (convert2digitIntoWords(div) + " lakhs ")
}

function convert6digitIntoWords(num) {
    var remainder = num % 100000
    var hun = num - remainder;
    var div = Math.floor(num / 100000);
    if (remainder !== 0)
        return (units[div] + " lakh " + convert5digitIntoWords(remainder))
    else
        return (units[div] + " lakh ")
}

function convert5digitIntoWords(num) {
    var remainder = num % 10000
    var hun = num - remainder;
    var div = Math.floor(num / 1000);
    if (remainder !== 0)
        return (convert2digitIntoWords(div) + " thousand " + convert3digitIntoWords(remainder % 1000))
    else
        return (convert2digitIntoWords(div) + " thousand")
}

function convert4digitIntoWords(num) {
    var remainder = num % 1000
    var hun = num - remainder;
    var div = Math.floor(num / 1000);
    if (remainder !== 0)
        return (units[div] + " thousand " + convert3digitIntoWords(remainder))
    else
        return (units[div] + " thousand")
}


function convert3digitIntoWords(num) {
    var remainder = num % 100
    var hun = num - remainder;
    var div = Math.floor(num / 100);
    if (remainder !== 0)
        return (units[div] + " hundred " + convert2digitIntoWords(remainder))
    else
        return (units[div] + " hundred ")
}

function convert2digitIntoWords(num) {
    var remainder = num % 10;
    var div = Math.floor(num / 10);
    return (tens[div] + " " + convertNumIntoWords(remainder));
}

function convertNumIntoWords(num) {

    switch (("" + num).length) {
        case 1:
            return units[num];
        case 2:
            return convert2digitIntoWords(num);
        case 3:
            return convert3digitIntoWords(num)
        case 4:
            return convert4digitIntoWords(num)
        case 5:
            return convert5digitIntoWords(num)
        case 6:
            return convert6digitIntoWords(num)
        case 7:
            return convert7digitIntoWords(num)
        default:
            return "cannot be converted"
    }
}

console.log(convertNumIntoWords(3445125));

Get href attribute on jQuery

var a_href = $('div.cpt').find('h2 a').attr('href');

should be

var a_href = $(this).find('div.cpt').find('h2 a').attr('href');

In the first line, your query searches the entire document. In the second, the query starts from your tr element and only gets the element underneath it. (You can combine the finds if you like, I left them separate to illustrate the point.)

How to print without newline or space?

In Python 3+, print is a function. When you call

print('hello world')

Python translates it to

print('hello world', end='\n')

You can change end to whatever you want.

print('hello world', end='')
print('hello world', end=' ')

How to take last four characters from a varchar?

For Oracle SQL, SUBSTR(column_name, -# of characters requested) will extract last three characters for a given query. e.g.

SELECT SUBSTR(description,-3) FROM student.course;

continuous page numbering through section breaks

You can check out this post on SuperUser.

Word starts page numbering over for each new section by default.

I do it slightly differently than the post above that goes through the ribbon menus, but in both methods you have to go through the document to each section's beginning.

My method:

  • open up the footer (or header if that's where your page number is)
  • drag-select the page number
  • right-click on it
  • hit Format Page Numbers
  • click on the Continue from Previous Section radio button under Page numbering

I find this right-click method to be a little faster. Also, usually if I insert the page numbers first before I start making any new sections, this problem doesn't happen in the first place.

Httpd returning 503 Service Unavailable with mod_proxy for Tomcat 8

Resolve issue Immediate, It's related to internal security

We, SnippetBucket.com working for enterprise linux RedHat, found httpd server don't allow proxy to run, neither localhost or 127.0.0.1, nor any other external domain.

As investigate in server log found

[error] (13)Permission denied: proxy: AJP: attempt to connect to
   10.x.x.x:8069 (virtualhost.virtualdomain.com) failed

Audit log found similar port issue

type=AVC msg=audit(1265039669.305:14): avc:  denied  { name_connect } for  pid=4343 comm="httpd" dest=8069 
scontext=system_u:system_r:httpd_t:s0 tcontext=system_u:object_r:port_t:s0 tclass=tcp_socket

Due to internal default security of linux, this cause, now to fix (temporary)

 /usr/sbin/setsebool httpd_can_network_connect 1

Resolve Permanent Issue

/usr/sbin/setsebool -P httpd_can_network_connect 1

onclick or inline script isn't working in extension

I decide to publish my example that I used in my case. I tried to replace content in div using a script. My problem was that Chrome did not recognized / did not run that script.

In more detail What I wanted to do: To click on a link, and that link to "read" an external html file, that it will be loaded in a div section.

  • I found out that by placing the script before the DIV with ID that was called, the script did not work.
  • If the script was in another DIV, also it does not work
  • The script must be coded using document.addEventListener('DOMContentLoaded', function() as it was told

        <body>
        <a id=id_page href ="#loving"   onclick="load_services()"> loving   </a>
    
            <script>
                    // This script MUST BE under the "ID" that is calling
                    // Do not transfer it to a differ DIV than the caller "ID"
                    document.getElementById("id_page").addEventListener("click", function(){
                    document.getElementById("mainbody").innerHTML = '<object data="Services.html" class="loving_css_edit"; ></object>'; });
                </script>
        </body>
    
      <div id="mainbody" class="main_body">
            "here is loaded the external html file when the loving link will 
             be  clicked. "
      </div>
    

Where can I find free WPF controls and control templates?

Syncfusion has a free community version available with over 650 controls.

Syncfusion

You will find an FAQ there with any licensing questions you may have, it sound great to be honest. Have fun!

Edit: The WPF controls themselves are 100+, the number of 650+ refers to all controls for all areas (WPF, Windows Forms etc).

I'm getting Key error in python

This means your array is missing the key you're looking for. I handle this with a function which either returns the value if it exists or it returns a default value instead.

def keyCheck(key, arr, default):
    if key in arr.keys():
        return arr[key]
    else:
        return default


myarray = {'key1':1, 'key2':2}

print keyCheck('key1', myarray, '#default')
print keyCheck('key2', myarray, '#default')
print keyCheck('key3', myarray, '#default')

Output:

1
2
#default

How can I increase a scrollbar's width using CSS?

If you are talking about the scrollbar that automatically appears on a div with overflow: scroll (or auto), then no, that's still a native scrollbar rendered by the browser using normal OS widgets, and not something that can be styled(*).

Whilst you can replace it with a proxy made out of stylable divs and JavaScript as suggested by Matt, I wouldn't recommend it for the general case. Script-driven scrollbars never quite behave exactly the same as real OS scrollbars, causing usability and accessibility problems.

(*: Except for the IE colouring styles, which I wouldn't really recommend either. Apart from being IE-only, using them forces IE to fall back from using nice scrollbar images from the current Windows theme to ugly old Win95-style scrollbars.)

when I try to open an HTML file through `http://localhost/xampp/htdocs/index.html` it says unable to connect to localhost

You should simply create your own folder in htdocs and save your .html and .php files in it. An example is create a folder called myNewFolder directly in htdocs. Don't put it in index.html. Then save all your.html and .php files in it like this-> "localhost/myNewFolder/myFilename.html" or "localhost/myNewFolder/myFilename.php" I hope this helps.

Hibernate: flush() and commit()

One common case for explicitly flushing is when you create a new persistent entity and you want it to have an artificial primary key generated and assigned to it, so that you can use it later on in the same transaction. In that case calling flush would result in your entity being given an id.

Another case is if there are a lot of things in the 1st-level cache and you'd like to clear it out periodically (in order to reduce the amount of memory used by the cache) but you still want to commit the whole thing together. This is the case that Aleksei's answer covers.

Kubernetes how to make Deployment to update image

kubectl rollout restart deployment myapp

This is the current way to trigger a rolling update and leave the old replica sets in place for other operations provided by kubectl rollout like rollbacks.

What is the shortcut to Auto import all in Android Studio?

On Windows, highlight the code that has classes which need to be resolved and hit Alt+Enter

Missing include "bits/c++config.h" when cross compiling 64 bit program on 32 bit in Ubuntu

On my 64 bit system I noticed that the following directory existed:

/usr/include/c++/4.4/x86_64-linux-gnu/32/bits

It would then make sense that on my 32 bit system that had been setup for 64bit cross compiling there should be a corresponding directory like:

/usr/include/c++/4.4/i686-linux-gnu/64/bits

I double checked and this directory did not exist. Running g++ with the verbose parameter showed that the compiler was actually looking for something in this location:

jesse@shalored:~/projects/test$ g++ -v -m64 main.cpp 
Using built-in specs.
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.4.4-14ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.4 --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5) 
COLLECT_GCC_OPTIONS='-v' '-m64' '-shared-libgcc' '-mtune=generic'
 /usr/lib/gcc/i686-linux-gnu/4.4.5/cc1plus -quiet -v -imultilib 64 -D_GNU_SOURCE main.cpp -D_FORTIFY_SOURCE=2 -quiet -dumpbase main.cpp -m64 -mtune=generic -auxbase main -version -fstack-protector -o /tmp/ccMvIfFH.s
ignoring nonexistent directory "/usr/include/c++/4.4/i686-linux-gnu/64"
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/i686-linux-gnu/4.4.5/../../../../i686-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/4.4
 /usr/include/c++/4.4/backward
 /usr/local/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include
 /usr/lib/gcc/i686-linux-gnu/4.4.5/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C++ (Ubuntu/Linaro 4.4.4-14ubuntu5) version 4.4.5 (i686-linux-gnu)
    compiled by GNU C version 4.4.5, GMP version 4.3.2, MPFR version 3.0.0-p3.
GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128197
Compiler executable checksum: 1fe36891f4a5f71e4a498e712867261c
In file included from main.cpp:1:
/usr/include/c++/4.4/iostream:39: fatal error: bits/c++config.h: No such file or directory
compilation terminated.

The error regarding the ignoring nonexistent directory was the clue. Unfortunately, I still don't know what package I need to install to have this directory show up so I just copied the /usr/include/c++/4.4/x86_64-linux-gnu/bits directory from my 64 bit machine to /usr/include/c++/4.4/i686-linux-gnu/64/bits on my 32 machine.

Now compiling with just the -m64 works correctly. The major drawback is that this is still not the correct way to do things and I am guessing the next time Update Manager installs and update to g++ things may break.

Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?

You shouldn't use money when you need to do multiplications / divisions on the value. Money is stored in the same way an integer is stored, whereas decimal is stored as a decimal point and decimal digits. This means that money will drop accuracy in most cases, while decimal will only do so when converted back to its original scale. Money is fixed point, so its scale doesn't change during calculations. However because it is fixed point when it gets printed as a decimal string (as opposed to as a fixed position in a base 2 string), values up to the scale of 4 are represented exactly. So for addition and subtraction, money is fine.

A decimal is represented in base 10 internally, and thus the position of the decimal point is also based on the base 10 number. Which makes its fractional part represent its value exactly, just like with money. The difference is that intermediate values of decimal can maintain precision up to 38 digits.

With a floating point number, the value is stored in binary as if it were an integer, and the decimal (or binary, ahem) point's position is relative to the bits representing the number. Because it is a binary decimal point, base 10 numbers lose precision right after the decimal point. 1/5th, or 0.2, cannot be represented precisely in this way. Neither money nor decimal suffer from this limitation.

It is easy enough to convert money to decimal, perform the calculations, and then store the resulting value back into a money field or variable.

From my POV, I want stuff that happens to numbers to just happen without having to give too much thought to them. If all calculations are going to get converted to decimal, then to me I'd just want to use decimal. I'd save the money field for display purposes.

Size-wise I don't see enough of a difference to change my mind. Money takes 4 - 8 bytes, whereas decimal can be 5, 9, 13, and 17. The 9 bytes can cover the entire range that the 8 bytes of money can. Index-wise (comparing and searching should be comparable).

Converting string to byte array in C#

Also you can use an Extension Method to add a method to the string type as below:

static class Helper
{
   public static byte[] ToByteArray(this string str)
   {
      return System.Text.Encoding.ASCII.GetBytes(str);
   }
}

And use it like below:

string foo = "bla bla";
byte[] result = foo.ToByteArray();

Why are primes important in cryptography?

Here is a very simple and common example.

The RSA encryption algorithm which is commonly used in secure commerce web sites, is based on the fact that it is easy to take two (very large) prime numbers and multiply them, while it is extremely hard to do the opposite - meaning: take a very large number, given which it has only two prime factors, and find them.

How to get form values in Symfony2 controller

I got it working by this:

if ($request->getMethod() == 'POST') {
    $username = $request->request->get('username');
    $password = $request->request->get('password');

    // Do something with the post data
}

You need to have the Request $request as a parameter in the function too! Hope this helps.

Read Post Data submitted to ASP.Net Form

NameValueCollection nvclc = Request.Form;
string   uName= nvclc ["txtUserName"];
string   pswod= nvclc ["txtPassword"];
//try login
CheckLogin(uName, pswod);