Programs & Examples On #Jet sql

ORA-03113: end-of-file on communication channel after long inactivity in ASP.Net app

end-of-file on communication channel:

One of the course of this error is due to database fail to write the log when its in the stage of opening;

Solution check the database if its running in ARCHIVELOG or NOARCHIVELOG

to check use

select log_mode from v$database;

if its on ARCHIVELOG try to change into NOARCHIVELOG

by using sqlplus

  • startup mount
  • alter database noarchivelog;
  • alter database open;

if it works for this

Then you can adjust your flashrecovery area its possibly that your flashrecovery area is full -> then after confirm that your flashrecovery area has the space you can alter your database into the ARCHIVELOG

Correct format specifier to print pointer or address?

As an alternative to the other (very good) answers, you could cast to uintptr_t or intptr_t (from stdint.h/inttypes.h) and use the corresponding integer conversion specifiers. This would allow more flexibility in how the pointer is formatted, but strictly speaking an implementation is not required to provide these typedefs.

'Field required a bean of type that could not be found.' error spring restful API using mongodb

Two types of mongo dependencies -

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency> 

Two types of repositories -

MongoRepository
ReactiveMongoRepository

Make sure you are using the right combination.

how to convert binary string to decimal?

function binaryToDecimal(string) {
    let decimal = +0;
    let bits = +1;
    for(let i = 0; i < string.length; i++) {
        let currNum = +(string[string.length - i - 1]);
        if(currNum === 1) {
            decimal += bits;
        }
        bits *= 2;
    }
    console.log(decimal);
}

How do I force detach Screen from another SSH session?

try with screen -d -r or screen -D -RR

Android Google Maps API V2 Zoom to Current Location

try this code :

private GoogleMap mMap;


LocationManager locationManager;


private static final String TAG = "";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(map);
    mapFragment.getMapAsync(this);

    arrayPoints = new ArrayList<LatLng>();
}

@Override
public void onMapReady(GoogleMap googleMap) {


    mMap = googleMap;


    mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);


    LatLng myPosition;


    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    googleMap.setMyLocationEnabled(true);
    LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    String provider = locationManager.getBestProvider(criteria, true);
    Location location = locationManager.getLastKnownLocation(provider);


    if (location != null) {
        double latitude = location.getLatitude();
        double longitude = location.getLongitude();
        LatLng latLng = new LatLng(latitude, longitude);
        myPosition = new LatLng(latitude, longitude);


        LatLng coordinate = new LatLng(latitude, longitude);
        CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(coordinate, 19);
        mMap.animateCamera(yourLocation);
    }
}

}

Dont forget to add permissions on AndroidManifest.xml.

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

How to print a percentage value in python?

Then you'd want to do this instead:

print str(int(1.0/3.0*100))+'%'

The .0 denotes them as floats and int() rounds them to integers afterwards again.

SQL Server: Filter output of sp_who2

Extension of the first and best answer... I have created a stored procedure on the master database that you can then pass parameters to .. such as the name of the database:

USE master
GO

CREATE PROCEDURE sp_who_db
(
    @sDBName varchar(200)   = null,
    @sStatus varchar(200)   = null,
    @sCommand varchar(200)  = null,
    @nCPUTime int           = null
)
AS
DECLARE @Table TABLE
(
    SPID INT,
    Status VARCHAR(MAX),
    LOGIN VARCHAR(MAX),
    HostName VARCHAR(MAX),
    BlkBy VARCHAR(MAX),
    DBName VARCHAR(MAX),
    Command VARCHAR(MAX),
    CPUTime INT,
    DiskIO INT,
    LastBatch VARCHAR(MAX),
    ProgramName VARCHAR(MAX),
    SPID_1 INT,
    REQUESTID INT
)

INSERT INTO @Table EXEC sp_who2

SELECT  *
    FROM    @Table
    WHERE   (@sDBName IS NULL OR DBName = @sDBName)
    AND     (@sStatus IS NULL OR Status = @sStatus)
    AND     (@sCommand IS NULL OR Command = @sCommand)
    AND     (@nCPUTime IS NULL OR CPUTime > @nCPUTime)
GO 

I might extend it to add an order by parameter or even a kill paramatmer so it kills all connections to a particular data

UL has margin on the left

by default <UL/> contains default padding

therefore try adding style to padding:0px in css class or inline css

How to check if an Object is a Collection Type in Java?

Update: there are two possible scenarios here:

  1. You are determining if an object is a collection;

  2. You are determining if a class is a collection.

The solutions are slightly different but the principles are the same. You also need to define what exactly constitutes a "collection". Implementing either Collection or Map will cover the Java Collections.

Solution 1:

public static boolean isCollection(Object ob) {
  return ob instanceof Collection || ob instanceof Map;
}

Solution 2:

public static boolean isClassCollection(Class c) {
  return Collection.class.isAssignableFrom(c) || Map.class.isAssignableFrom(c);
}

(1) can also be implemented in terms of (2):

public static boolean isCollection(Object ob) {
  return ob != null && isClassCollection(ob.getClass());
}

I don't think the efficiency of either method will be greatly different from the other.

Ansible: how to get output to display

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

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

---
- hosts: localhost
  tasks:
    - shell: ls
      register: shell_result

    - debug:
        var: shell_result.stdout_lines

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

An example run would look like the this:

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

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

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

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

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

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

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

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

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

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

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

  - debug:
      var: jenkins_result.output

How to Consolidate Data from Multiple Excel Columns All into One Column

Take a look at Blockspring - you do need to install the plugin, but then it's just another function you call like this:

=BLOCKSPRING("twodee-array-reduce","input_array",D5:F7)

The source code and other details are here. If this doesn't suit and/or you want to build off my solution, you can fork my function (Python) or use another supported scripting language (Ruby, R, JS, etc...).

Non-numeric Argument to Binary Operator Error in R

Because your question is phrased regarding your error message and not whatever your function is trying to accomplish, I will address the error.

- is the 'binary operator' your error is referencing, and either CurrentDay or MA (or both) are non-numeric.

A binary operation is a calculation that takes two values (operands) and produces another value (see wikipedia for more). + is one such operator: "1 + 1" takes two operands (1 and 1) and produces another value (2). Note that the produced value isn't necessarily different from the operands (e.g., 1 + 0 = 1).

R only knows how to apply + (and other binary operators, such as -) to numeric arguments:

> 1 + 1
[1] 2
> 1 + 'one'
Error in 1 + "one" : non-numeric argument to binary operator

When you see that error message, it means that you are (or the function you're calling is) trying to perform a binary operation with something that isn't a number.

EDIT:

Your error lies in the use of [ instead of [[. Because Day is a list, subsetting with [ will return a list, not a numeric vector. [[, however, returns an object of the class of the item contained in the list:

> Day <- Transaction(1, 2)["b"]
> class(Day)
[1] "list"
> Day + 1
Error in Day + 1 : non-numeric argument to binary operator

> Day2 <- Transaction(1, 2)[["b"]]
> class(Day2)
[1] "numeric"
> Day2 + 1
[1] 3

Transaction, as you've defined it, returns a list of two vectors. Above, Day is a list contain one vector. Day2, however, is simply a vector.

Sorting int array in descending order

If it's not a big/long array just mirror it:

for( int i = 0; i < arr.length/2; ++i ) 
{ 
  temp = arr[i]; 
  arr[i] = arr[arr.length - i - 1]; 
  arr[arr.length - i - 1] = temp; 
}

A method to reverse effect of java String.split()?

This one is not bad too :

public static String join(String delimitor,String ... subkeys) {
    String result = null;
    if(null!=subkeys && subkeys.length>0) {
        StringBuffer joinBuffer = new StringBuffer(subkeys[0]);
        for(int idx=1;idx<subkeys.length;idx++) {
            joinBuffer.append(delimitor).append(subkeys[idx]);
        }
        result = joinBuffer.toString();
    }
    return result;
}

How to split the filename from a full path in batch?

@echo off
Set filename="C:\Documents and Settings\All Users\Desktop\Dostips.cmd"
call :expand %filename%
:expand
set filename=%~nx1
echo The name of the file is %filename%
set folder=%~dp1
echo It's path is %folder%

batch file to list folders within a folder to one level

I tried this command to display the list of files in the directory.

dir /s /b > List.txt

In the file it displays the list below.

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\XmppMgr.dll

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\XmppSDK.dll

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\accessories\Plantronics

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\accessories\SennheiserJabberPlugin.dll

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\accessories\Logitech\LogiUCPluginForCisco

C:\Program Files (x86)\Cisco Systems\Cisco Jabber\accessories\Logitech\LogiUCPluginForCisco\lucpcisco.dll

What is want to do is only to display sub-directory not the full directory path.

Just like this:

Cisco Jabber\XmppMgr.dll Cisco Jabber\XmppSDK.dll

Cisco Jabber\accessories\JabraJabberPlugin.dll

Cisco Jabber\accessories\Logitech

Cisco Jabber\accessories\Plantronics

Cisco Jabber\accessories\SennheiserJabberPlugin.dll

Doctrine findBy 'does not equal'

There is no built-in method that allows what you intend to do.

You have to add a method to your repository, like this:

public function getWhatYouWant()
{
    $qb = $this->createQueryBuilder('u');
    $qb->where('u.id != :identifier')
       ->setParameter('identifier', 1);

    return $qb->getQuery()
          ->getResult();
}

Hope this helps.

Histogram Matplotlib

I know this does not answer your question, but I always end up on this page, when I search for the matplotlib solution to histograms, because the simple histogram_demo was removed from the matplotlib example gallery page.

Here is a solution, which doesn't require numpy to be imported. I only import numpy to generate the data x to be plotted. It relies on the function hist instead of the function bar as in the answer by @unutbu.

import numpy as np
mu, sigma = 100, 15
x = mu + sigma * np.random.randn(10000)

import matplotlib.pyplot as plt
plt.hist(x, bins=50)
plt.savefig('hist.png')

enter image description here

Also check out the matplotlib gallery and the matplotlib examples.

Floating divs in Bootstrap layout

From all I have read you cannot do exactly what you want without javascript. If you float left before text

<div style="float:left;">widget</div> here is some CONTENT, etc.

Your content wraps as expected. But your widget is in the top left. If you instead put the float after the content

here is some CONTENT, etc. <div style="float:left;">widget</div>

Then your content will wrap the last line to the right of the widget if the last line of content can fit to the right of the widget, otherwise no wrapping is done. To make borders and backgrounds actually include the floated area in the previous example, most people add:

here is some CONTENT, etc. <div style="float:left;">widget</div><div style="clear:both;"></div>

In your question you are using bootstrap which just adds row-fluid::after { content: ""} which resolves the border/background issue.

Moving your content up will give you the one line wrap : http://jsfiddle.net/jJNPY/34/

  <div class="container-fluid">
  <div class="row-fluid">
    <div class="offset1 span8 pull-right">
    ... Widget 1...
    </div>
    .... a lot of content ....
    <div class="span8" style="margin-left: 0;">
    ... Widget 2...
    </div>


  </div>

</div><!--/.fluid-container-->

How to configure log4j.properties for SpringJUnit4ClassRunner?

The new tests you wrote (directly or indirectly) use classes that log using Log4j.

Log4J needs to be configured for this logging to work properly.

Put a log4j.properties (or log4j.xml) file in the root of your test classpath.

It should have some basic configuration such as

# Set root logger level to DEBUG and its only appender to A1.
log4j.rootLogger=DEBUG, A1

# A1 is set to be a ConsoleAppender.
log4j.appender.A1=org.apache.log4j.ConsoleAppender

# A1 uses PatternLayout.
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n

# An alternative logging format:
# log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1} - %m%n

An appender outputs to the console by default, but you can also explicitly set the target like this:

log4j.appender.A1.Target=System.out

This will redirect all output in a nice format to the console. More info can be found here in the Log4J manual,

Log4J Logging will then be properly configured and this warning will disappear.

Using Google Translate in C#

Google is going to shut the translate API down by the end of 2011, so you should be looking at the alternatives!

Searching for UUIDs in text with regex

In python re, you can span from numberic to upper case alpha. So..

import re
test = "01234ABCDEFGHIJKabcdefghijk01234abcdefghijkABCDEFGHIJK"
re.compile(r'[0-f]+').findall(test) # Bad: matches all uppercase alpha chars
## ['01234ABCDEFGHIJKabcdef', '01234abcdef', 'ABCDEFGHIJK']
re.compile(r'[0-F]+').findall(test) # Partial: does not match lowercase hex chars
## ['01234ABCDEF', '01234', 'ABCDEF']
re.compile(r'[0-F]+', re.I).findall(test) # Good
## ['01234ABCDEF', 'abcdef', '01234abcdef', 'ABCDEF']
re.compile(r'[0-f]+', re.I).findall(test) # Good
## ['01234ABCDEF', 'abcdef', '01234abcdef', 'ABCDEF']
re.compile(r'[0-Fa-f]+').findall(test) # Good (with uppercase-only magic)
## ['01234ABCDEF', 'abcdef', '01234abcdef', 'ABCDEF']
re.compile(r'[0-9a-fA-F]+').findall(test) # Good (with no magic)
## ['01234ABCDEF', 'abcdef', '01234abcdef', 'ABCDEF']

That makes the simplest Python UUID regex:

re_uuid = re.compile("[0-F]{8}-([0-F]{4}-){3}[0-F]{12}", re.I)

I'll leave it as an exercise to the reader to use timeit to compare the performance of these.

Enjoy. Keep it Pythonic™!

NOTE: Those spans will also match :;<=>?@' so, if you suspect that could give you false positives, don't take the shortcut. (Thank you Oliver Aubert for pointing that out in the comments.)

What is the python keyword "with" used for?

In python the with keyword is used when working with unmanaged resources (like file streams). It is similar to the using statement in VB.NET and C#. It allows you to ensure that a resource is "cleaned up" when the code that uses it finishes running, even if exceptions are thrown. It provides 'syntactic sugar' for try/finally blocks.

From Python Docs:

The with statement clarifies code that previously would use try...finally blocks to ensure that clean-up code is executed. In this section, I’ll discuss the statement as it will commonly be used. In the next section, I’ll examine the implementation details and show how to write objects for use with this statement.

The with statement is a control-flow structure whose basic structure is:

with expression [as variable]:
    with-block

The expression is evaluated, and it should result in an object that supports the context management protocol (that is, has __enter__() and __exit__() methods).

Update fixed VB callout per Scott Wisniewski's comment. I was indeed confusing with with using.

How To Include CSS and jQuery in my WordPress plugin?

First you need to register the style and css using wp_register_script() and wp_register_style() functions

 //registering javascript and css
 wp_register_script ( 'mysample', plugins_url ( 'js/myjs.js', __FILE__ ) );
 wp_register_style ( 'mysample', plugins_url ( 'css/mystyle.css', __FILE__ ) );

After this you can call the wp_enqueue_script() and wp_enqueue_style() functions for loading the js and css in required page

wp_enqueue_script('mysample');
wp_enqueue_style('mysample');

I fount a nice example here http://wiki.workassis.com/wordpress-create-advanced-custom-plugin-using-oop/

Add row to query result using select

You use it like this:

SELECT  age, name
FROM    users
UNION
SELECT  25 AS age, 'Betty' AS name

Use UNION ALL to allow duplicates: if there is a 25-years old Betty among your users, the second query will not select her again with mere UNION.

Android XML Percent Symbol

To allow the app using formatted strings from resources you should correct your xml. So, for example

<string name="app_name">Your App name, ver.%d</string>

should be replaced with

<string name="app_name">Your App name, ver.%1$d</string>

You can see this for details.

Message "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout"

Make sure to invoke done(); on callbacks or it simply won't pass the test.

beforeAll((done /* Call it or remove it */ ) => {
  done(); // Calling it
});

It applies to all other functions that have a done() callback.

In Laravel, the best way to pass different types of flash messages in the session

In your view:

<div class="flash-message">
  @foreach (['danger', 'warning', 'success', 'info'] as $msg)
    @if(Session::has('alert-' . $msg))
    <p class="alert alert-{{ $msg }}">{{ Session::get('alert-' . $msg) }}</p>
    @endif
  @endforeach
</div>

Then set a flash message in the controller:

Session::flash('alert-danger', 'danger');
Session::flash('alert-warning', 'warning');
Session::flash('alert-success', 'success');
Session::flash('alert-info', 'info');

How to set size for local image using knitr for markdown?

Had the same issue today and found another option with knitr 1.16 when knitting to PDF (which requires that you have pandoc installed):

![Image Title](path/to/your/image){width=70%}

This method may require that you do a bit of trial and error to find the size that works for you. It is especially convenient because it makes putting two images side by side a prettier process. For example:

![Image 1](path/to/image1){width=70%}![Image 2](path/to/image2){width=30%}

You can get creative and stack a couple of these side by side and size them as you see fit. See https://rpubs.com/RatherBit/90926 for more ideas and examples.

Return in Scala

It's not as simple as just omitting the return keyword. In Scala, if there is no return then the last expression is taken to be the return value. So, if the last expression is what you want to return, then you can omit the return keyword. But if what you want to return is not the last expression, then Scala will not know that you wanted to return it.

An example:

def f() = {
  if (something)
    "A"
  else
    "B"
}

Here the last expression of the function f is an if/else expression that evaluates to a String. Since there is no explicit return marked, Scala will infer that you wanted to return the result of this if/else expression: a String.

Now, if we add something after the if/else expression:

def f() = {
  if (something)
    "A"
  else
    "B"

  if (somethingElse)
    1
  else
    2
}

Now the last expression is an if/else expression that evaluates to an Int. So the return type of f will be Int. If we really wanted it to return the String, then we're in trouble because Scala has no idea that that's what we intended. Thus, we have to fix it by either storing the String to a variable and returning it after the second if/else expression, or by changing the order so that the String part happens last.

Finally, we can avoid the return keyword even with a nested if-else expression like yours:

def f() = {
  if(somethingFirst) {
    if (something)      // Last expression of `if` returns a String
     "A"
    else
     "B"
  }
  else {
    if (somethingElse)
      1
    else
      2

    "C"                // Last expression of `else` returns a String
  }

}

Closing WebSocket correctly (HTML5, Javascript)

According to the protocol spec v76 (which is the version that browser with current support implement):

To close the connection cleanly, a frame consisting of just a 0xFF byte followed by a 0x00 byte is sent from one peer to ask that the other peer close the connection.

If you are writing a server, you should make sure to send a close frame when the server closes a client connection. The normal TCP socket close method can sometimes be slow and cause applications to think the connection is still open even when it's not.

The browser should really do this for you when you close or reload the page. However, you can make sure a close frame is sent by doing capturing the beforeunload event:

window.onbeforeunload = function() {
    websocket.onclose = function () {}; // disable onclose handler first
    websocket.close();
};

I'm not sure how you can be getting an onclose event after the page is refreshed. The websocket object (with the onclose handler) will no longer exist once the page reloads. If you are immediately trying to establish a WebSocket connection on your page as the page loads, then you may be running into an issue where the server is refusing a new connection so soon after the old one has disconnected (or the browser isn't ready to make connections at the point you are trying to connect) and you are getting an onclose event for the new websocket object.

How to automatically crop and center an image

Try this: Set your image crop dimensions and use this line in your CSS:

object-fit: cover;

Editing in the Chrome debugger

I came across this today, when I was playing around with someone else's website.

I realized I could attach a break-point in the debugger to some line of code before what I wanted to dynamically edit. And since break-points stay even after a reload of the page, I was able to edit the changes I wanted while paused at break-point and then continued to let the page load.

So as a quick work around, and if it works with your situation:

  1. Add a break-point at an earlier point in the script
  2. Reload page
  3. Edit your changes into the code
  4. CTRL + s (save changes)
  5. Unpause the debugger

Increasing the Command Timeout for SQL command

Since it takes 2 mins to respond, you can increase the timeout to 3 mins by adding the below code

scGetruntotals.CommandTimeout = 180;

Note : the parameter value is in seconds.

How to implement the Java comparable interface?

This thing can easily be done by implementing a public class that implements Comparable. This will allow you to use compareTo method which can be used with any other object to which you wish to compare.

for example you can implement it in this way:

public String compareTo(Animal oth) 
{
    return String.compare(this.population, oth.population);
}

I think this might solve your purpose.

[Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified

The Problem might be from the driver name for example instead of DRIVER={MySQL ODBC 5.3 Driver} try DRIVER={MySQL ODBC 5.3 Unicode Driver} you can see the name of the driver from administration tool

How to format numbers by prepending 0 to single-digit numbers?

You can do:

function pad2(number) {
   return (number < 10 ? '0' : '') + number
}

Example:

document.write(pad2(0) + '<br />');
document.write(pad2(1) + '<br />');
document.write(pad2(2) + '<br />');
document.write(pad2(10) + '<br />');
document.write(pad2(15) + '<br />');

Result:

00
01
02
10
15

onNewIntent() lifecycle and registered listeners

onNewIntent() is meant as entry point for singleTop activities which already run somewhere else in the stack and therefore can't call onCreate(). From activities lifecycle point of view it's therefore needed to call onPause() before onNewIntent(). I suggest you to rewrite your activity to not use these listeners inside of onNewIntent(). For example most of the time my onNewIntent() methods simply looks like this:

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    // getIntent() should always return the most recent
    setIntent(intent);
}

With all setup logic happening in onResume() by utilizing getIntent().

TypeScript and field initializers

I suggest an approach that does not require Typescript 2.1:

class Person {
    public name: string;
    public address?: string;
    public age: number;

    public constructor(init:Person) {
        Object.assign(this, init);
    }

    public someFunc() {
        // todo
    }
}

let person = new Person(<Person>{ age:20, name:"John" });
person.someFunc();

key points:

  • Typescript 2.1 not required, Partial<T> not required
  • It supports functions (in comparison with simple type assertion which does not support functions)

Video file formats supported in iPhone

The short answer is the iPhone supports H.264 video, High profile and AAC audio, in container formats .mov, .mp4, or MPEG Segment .ts. MPEG Segment files are used for HTTP Live Streaming.

  • For maximum compatibility with Android and desktop browsers, use H.264 + AAC in an .mp4 container.
  • For extended length videos longer than 10 minutes you must use HTTP Live Streaming, which is H.264 + AAC in a series of small .ts container files (see App Store Review Guidelines rule 2.5.7).

Video

On the iPhone, H.264 is the only game in town. [1]

There are several different feature tiers or "profiles" available in H.264. All modern iPhones (3GS and above) support the High profile. These profiles are basically three different levels of algorithm "tricks" used to compress the video. More tricks give better compression, but require more CPU or dedicated hardware to decode. This is a table that lists the differences between the different profiles.

[1] Interestingly, Apple's own Facetime uses the newer H.265 (HEVC) video codec. However right now (August 2017) there is no Apple-provided library that gives access to a HEVC codec to developers. This is expected to change at some point.

In talking about what video format the iPhone supports, a distinction should be made between what the hardware can support, and what the (much lower) limits are for playback when streaming over a network.

The only data given about hardware video support by Apple about the current generation of iPhones (SE, 6S, 6S Plus, 7, 7 Plus) is that they support

4K [3840x2160] video recording at 30 fps

1080p [1920x1080] HD video recording at 30 fps or 60 fps.

Obviously the phone can play back what it can record, so we can guess that 3840x2160 at 30 fps and 1920x1080 at 60 fps represent design limits of the phone. In addition, the screen size on the 6S Plus and 7 Plus is 1920x1080. So if you're interested in playback on the phone, it doesn't make sense to send over more pixels then the screen can draw.

However, streaming video is a different matter. Since networks are slow and video is huge, it's typical to use lower resolutions, bitrates, and frame rates than the device's theoretical maximum.

The most detailed document giving recommendations for streaming is TN2224 Best Practices for Creating and Deploying HTTP Live Streaming Media for Apple Devices. Figure 3 in that document gives a table of recommended streaming parameters:

Table of Apple recommended video encoding settings This table is from May 2016.

As you can see, Apple recommends the relatively low resolution of 768x432 as the highest recommended resolution for streaming over a cellular network. Of course this is just a recommendation and YMMV.

Audio

The question is about video, but that video generally has one or more audio tracks with it. The iPhone supports a few audio formats, but the most modern and by far most widely used is AAC. The iPhone 7 / 7 Plus, 6S Plus / 6S, SE all support AAC bitrates of 8 to 320 Kbps.

Container

The audio and video tracks go inside a container. The purpose of the container is to combine (interleave) the different tracks together, to store metadata, and to support seeking. The iPhone supports

  1. QuickTime .mov,
  2. MP4, and
  3. MPEG-TS.

The .mov and .mp4 file formats are closely related (.mp4 is in fact based on .mov), however .mp4 is an ISO standard that has much wider support.

As noted above, you have to use MPEG-TS for videos longer than 10 minutes.

Calling a function every 60 seconds

If you don't care if the code within the timer may take longer than your interval, use setInterval():

setInterval(function, delay)

That fires the function passed in as first parameter over and over.

A better approach is, to use setTimeout along with a self-executing anonymous function:

(function(){
    // do some stuff
    setTimeout(arguments.callee, 60000);
})();

that guarantees, that the next call is not made before your code was executed. I used arguments.callee in this example as function reference. It's a better way to give the function a name and call that within setTimeout because arguments.callee is deprecated in ecmascript 5.

remove objects from array by object property

If you like short and self descriptive parameters or if you don't want to use splice and go with a straight forward filter or if you are simply a SQL person like me:

function removeFromArrayOfHash(p_array_of_hash, p_key, p_value_to_remove){
    return p_array_of_hash.filter((l_cur_row) => {return l_cur_row[p_key] != p_value_to_remove});
}

And a sample usage:

l_test_arr = 
[
    {
         post_id: 1,
        post_content: "Hey I am the first hash with id 1"
    },
    {
        post_id: 2,
        post_content: "This is item 2"
    },
    {
        post_id: 1,
        post_content: "And I am the second hash with id 1"
    },
    {
        post_id: 3,
        post_content: "This is item 3"
    },
 ];



 l_test_arr = removeFromArrayOfHash(l_test_arr, "post_id", 2); // gives both of the post_id 1 hashes and the post_id 3
 l_test_arr = removeFromArrayOfHash(l_test_arr, "post_id", 1); // gives only post_id 3 (since 1 was removed in previous line)

C++ multiline string literal

Option 1. Using boost library, you can declare the string as below

const boost::string_view helpText = "This is very long help text.\n"
      "Also more text is here\n"
      "And here\n"

// Pass help text here
setHelpText(helpText);

Option 2. If boost is not available in your project, you can use std::string_view() in modern C++.

What are good ways to prevent SQL injection?

SQL injection can be a tricky problem but there are ways around it. Your risk is reduced your risk simply by using an ORM like Linq2Entities, Linq2SQL, NHibrenate. However you can have SQL injection problems even with them.

The main thing with SQL injection is user controlled input (as is with XSS). In the most simple example if you have a login form (I hope you never have one that just does this) that takes a username and password.

SELECT * FROM Users WHERE Username = '" + username + "' AND password = '" + password + "'"

If a user were to input the following for the username Admin' -- the SQL Statement would look like this when executing against the database.

SELECT * FROM Users WHERE Username = 'Admin' --' AND password = ''

In this simple case using a paramaterized query (which is what an ORM does) would remove your risk. You also have a the issue of a lesser known SQL injection attack vector and that's with stored procedures. In this case even if you use a paramaterized query or an ORM you would still have a SQL injection problem. Stored procedures can contain execute commands, and those commands themselves may be suceptable to SQL injection attacks.

CREATE PROCEDURE SP_GetLogin @username varchar(100), @password varchar(100) AS
DECLARE @sql nvarchar(4000)
SELECT @sql = ' SELECT * FROM users' +
              ' FROM Product Where username = ''' + @username + ''' AND password = '''+@password+''''

EXECUTE sp_executesql @sql

So this example would have the same SQL injection problem as the previous one even if you use paramaterized queries or an ORM. And although the example seems silly you'd be surprised as to how often something like this is written.

My recommendations would be to use an ORM to immediately reduce your chances of having a SQL injection problem, and then learn to spot code and stored procedures which can have the problem and work to fix them. I don't recommend using ADO.NET (SqlClient, SqlCommand etc...) directly unless you have to, not because it's somehow not safe to use it with parameters but because it's that much easier to get lazy and just start writing a SQL query using strings and just ignoring the parameters. ORMS do a great job of forcing you to use parameters because it's just what they do.

Next Visit the OWASP site on SQL injection https://www.owasp.org/index.php/SQL_Injection and use the SQL injection cheat sheet to make sure you can spot and take out any issues that will arise in your code. https://www.owasp.org/index.php/SQL_Injection_Prevention_Cheat_Sheet finally I would say put in place a good code review between you and other developers at your company where you can review each others code for things like SQL injection and XSS. A lot of times programmers miss this stuff because they're trying to rush out some feature and don't spend too much time on reviewing their code.

Subtract two dates in SQL and get days of the result

How about

Select I.Fee
From Item I
WHERE  (days(GETDATE()) - days(I.DateCreated) < 365)

Checking if form has been submitted - PHP

Try this

 <form action="" method="POST" id="formaddtask">
      Add Task: <input type="text"name="newtaskname" />
      <input type="submit" value="Submit"/>
 </form>

    //Check if the form is submitted
    if($_SERVER['REQUEST_METHOD'] == 'POST' && !empty($_POST['newtaskname'])){

    }

Install IPA with iTunes 12

For iTunes 12.7.0 and above, you just need to Cmd+c your app and Cmd+v into your device on iTunes. Any tab works, including Summary, Music, Movies.

convert float into varchar in SQL server without scientific notation

Try this:

SELECT REPLACE(RTRIM(REPLACE(REPLACE(RTRIM(REPLACE(CAST(CAST(YOUR_FLOAT_COLUMN_NAME AS DECIMAL(18,9)) AS VARCHAR(20)),'0',' ')),' ','0'),'.',' ')),' ','.') FROM YOUR_TABLE_NAME
  1. Casting as DECIMAL will put decimal point on every value, whether it had one before or not.
  2. Casting as VARCHAR allows you to use the REPLACE function
  3. First REPLACE zeros with spaces, then RTRIM to get rid of all trailing spaces (formerly zeros), then REPLACE remaining spaces with zeros.
  4. Then do the same for the period to get rid of it for numbers with no decimal values.

PHP - get base64 img string decode and save as jpg (resulting empty image )

Here's what finally worked for me. You'll have to convert the code to suit your own needs, but this will do it.

$fname = filter_input(INPUT_POST, "name");
$img = filter_input(INPUT_POST, "image");
$img = str_replace('data:image/png;base64,', '', $img);
$img = str_replace(' ', '+', $img);
$img = base64_decode($img);

file_put_contents($fname, $img);

print "Image has been saved!";

How to run SQL script in MySQL?

I had this error, and tried all the advice i could get to no avail.

Finally, the problem was that my folder had a space in the folder name which appearing as a forward-slash in the folder path, once i found and removed it, it worked fine.

RecyclerView expand/collapse items

I am surprised that there's no concise answer yet, although such an expand/collapse animation is very easy to achieve with just 2 lines of code:

(recycler.itemAnimator as SimpleItemAnimator).supportsChangeAnimations = false // called once

together with

notifyItemChanged(position) // in adapter, whenever a child view in item's recycler gets hidden/shown

So for me, the explanations in the link below were really useful: https://medium.com/@nikola.jakshic/how-to-expand-collapse-items-in-recyclerview-49a648a403a6

How to set session variable in jquery?

Use localStorage to store the fact that you opened the page :

$(document).ready(function() {
    var yetVisited = localStorage['visited'];
    if (!yetVisited) {
        // open popup
        localStorage['visited'] = "yes";
    }
});

AngularJS : When to use service instead of factory

Even when they say that all services and factories are singleton, I don't agree 100 percent with that. I would say that factories are not singletons and this is the point of my answer. I would really think about the name that defines every component(Service/Factory), I mean:

A factory because is not a singleton, you can create as many as you want when you inject, so it works like a factory of objects. You can create a factory of an entity of your domain and work more comfortably with this objects which could be like an object of your model. When you retrieve several objects you can map them in this objects and it can act kind of another layer between the DDBB and the AngularJs model.You can add methods to the objects so you oriented to objects a little bit more your AngularJs App.

Meanwhile a service is a singleton, so we can only create 1 of a kind, maybe not create but we have only 1 instance when we inject in a controller, so a service provides more like a common service(rest calls,functionality.. ) to the controllers.

Conceptually you can think like services provide a service, factories can create multiple instances(objects) of a class

Spring Boot, Spring Data JPA with multiple DataSources

don't know why, but it works. Two configuration are the same, just change xxx to your name.

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
    entityManagerFactoryRef = "xxxEntityManager",
    transactionManagerRef = "xxxTransactionManager",
    basePackages = {"aaa.xxx"})
 public class RepositoryConfig {
@Autowired
private Environment env;

@Bean
@Primary
@ConfigurationProperties(prefix="datasource.xxx")
public DataSource xxxDataSource() {
    return DataSourceBuilder.create().build();
}

@Bean
public LocalContainerEntityManagerFactoryBean xxxEntityManager() {
    LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
    em.setDataSource(xxxDataSource());
    em.setPackagesToScan(new String[] {"aaa.xxx"});

    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    em.setJpaVendorAdapter(vendorAdapter);
    HashMap<String, Object> properties = new HashMap<String, Object>();
    properties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
    properties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
    properties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
    em.setJpaPropertyMap(properties);

    return em;
}

@Bean(name = "xxxTransactionManager")
public PlatformTransactionManager xxxTransactionManager() {
    JpaTransactionManager tm = new JpaTransactionManager();
    tm.setEntityManagerFactory(xxxEntityManager().getObject());
    return tm;
}

}

Laravel redirect back to original destination after login

I am using the following approach with a custom login controller and middleware for Laravel 5.7, but I hope that works in any of laravel 5 versions

  • inside middleware

    if (Auth::check()){
        return $next($request);
    }
    else{
      return redirect()->guest(route('login'));
    }
    
  • inside controller login method

    if (Auth::attempt(['email' => $email, 'password' => $password])) {
    return redirect()->intended('/default');
    }
    
  • If you need to pass the intented url to client side, you can try the following

       if (Auth::attempt(['username' => $request->username, 'password' => $request->password])) {
           $intended_url= redirect()->intended('/default')->getTargetUrl();
           $response = array(
          'status' => 'success',
          'redirectUrl' => $intended_url,
          'message' => 'Login successful.you will be redirected to home..', );
          return response()->json($response);
        } else {
            $response = array(
          'status' => 'failed',
          'message' => 'username or password is incorrect', );
         return response()->json($response);
        }
    

What are Maven goals and phases and what is their difference?

The chosen answer is great, but still I would like to add something small to the topic. An illustration.

It clearly demonstrates how the different phases binded to different plugins and the goals that those plugins expose.

So, let's examine a case of running something like mvn compile:

  • It's a phase which execute the compiler plugin with compile goal
  • Compiler plugin got different goals. For mvn compile it's mapped to a specific goal, the compile goal.
  • It's the same as running mvn compiler:compile

Therefore, phase is made up of plugin goals.

enter image description here

Link to the reference

jQuery: How to detect window width on the fly?

I dont know if this useful for you when you resize your page:

$(window).resize(function() {
       if(screen.width == window.innerWidth){
           alert("you are on normal page with 100% zoom");
       } else if(screen.width > window.innerWidth){
           alert("you have zoomed in the page i.e more than 100%");
       } else {
           alert("you have zoomed out i.e less than 100%");
       }
    });

HttpServletRequest - how to obtain the referring URL?

The URLs are passed in the request: request.getRequestURL().

If you mean other sites that are linking to you? You want to capture the HTTP Referrer, which you can do by calling:

request.getHeader("referer");

How do I write a correct micro-benchmark in Java?

There are many possible pitfalls for writing micro-benchmarks in Java.

First: You have to calculate with all sorts of events that take time more or less random: Garbage collection, caching effects (of OS for files and of CPU for memory), IO etc.

Second: You cannot trust the accuracy of the measured times for very short intervals.

Third: The JVM optimizes your code while executing. So different runs in the same JVM-instance will become faster and faster.

My recommendations: Make your benchmark run some seconds, that is more reliable than a runtime over milliseconds. Warm up the JVM (means running the benchmark at least once without measuring, that the JVM can run optimizations). And run your benchmark multiple times (maybe 5 times) and take the median-value. Run every micro-benchmark in a new JVM-instance (call for every benchmark new Java) otherwise optimization effects of the JVM can influence later running tests. Don't execute things, that aren't executed in the warmup-phase (as this could trigger class-load and recompilation).

Sort an ArrayList based on an object field

Use a custom comparator:

Collections.sort(nodeList, new Comparator<DataNode>(){
     public int compare(DataNode o1, DataNode o2){
         if(o1.degree == o2.degree)
             return 0;
         return o1.degree < o2.degree ? -1 : 1;
     }
});

How to set 24-hours format for date on java?

for 12-hours format:

SimpleDateFormat simpleDateFormatArrivals = new SimpleDateFormat("hh:mm", Locale.UK);

for 24-hours format:

SimpleDateFormat simpleDateFormatArrivals = new SimpleDateFormat("HH:mm", Locale.UK);

JavaScript checking for null vs. undefined and difference between == and ===

The difference is subtle.

In JavaScript an undefined variable is a variable that as never been declared, or never assigned a value. Let's say you declare var a; for instance, then a will be undefined, because it was never assigned any value.

But if you then assign a = null; then a will now be null. In JavaScript null is an object (try typeof null in a JavaScript console if you don't believe me), which means that null is a value (in fact even undefined is a value).

Example:

var a;
typeof a;     # => "undefined"

a = null;
typeof null;  # => "object"

This can prove useful in function arguments. You may want to have a default value, but consider null to be acceptable. In which case you may do:

function doSomething(first, second, optional) {
    if (typeof optional === "undefined") {
        optional = "three";
    }
    // do something
}

If you omit the optional parameter doSomething(1, 2) thenoptional will be the "three" string but if you pass doSomething(1, 2, null) then optional will be null.

As for the equal == and strictly equal === comparators, the first one is weakly type, while strictly equal also checks for the type of values. That means that 0 == "0" will return true; while 0 === "0" will return false, because a number is not a string.

You may use those operators to check between undefined an null. For example:

null === null            # => true
undefined === undefined  # => true
undefined === null       # => false
undefined == null        # => true

The last case is interesting, because it allows you to check if a variable is either undefined or null and nothing else:

function test(val) {
    return val == null;
}
test(null);       # => true
test(undefined);  # => true

How to read Data from Excel sheet in selenium webdriver

i have used following method to use input data from excel sheet: Need to import following as well

import jxl.Workbook;

then

Workbook wBook = Workbook.getWorkbook(new File("E:\\Testdata\\ShellData.xls"));
//get sheet
jxl.Sheet Sheet = wBook.getSheet(0); 
//Now in application i have given my Username and Password input in following way
driver.findElement(By.xpath("//input[@id='UserName']")).sendKeys(Sheet.getCell(0, i).getContents());
driver.findElement(By.xpath("//input[@id='Password']")).sendKeys(Sheet.getCell(1, i).getContents());
driver.findElement(By.xpath("//input[@name='Login']")).click();

it will Work

How to add a Hint in spinner in XML

For Kotlin

What will you get:

Gray color if the hint is selected

Drop down list with gray color of the hint

Black color if something else than the hint is selected

I have added 5. step what changes the color of the text in the spinner depending on the selected item, because I couldn't find it here. In this case it is needed to change the text color to gray when the first item is selected in order to it looks like a hint.

  1. Define a spinner in your activity_layout.xml

    <Spinner
        android:id="@+id/mySpinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    
  2. Define the string array in string.xml where the first item will be a hint.

    <string-array name="your_string_array">
        <item>Hint...</item>
        <item>Item1</item>
        <item>Item2</item>
        <item>Item3</item>
    </string-array>
    
  3. Set up the spinner in the onCreate method in your Activity.kt

    Get string array from resources

        val items= resources.getStringArray(R.array.your_string_array)
    

    Create spinner adapter

        val spinnerAdapter= object : ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, items) {
    
        override fun isEnabled(position: Int): Boolean {
            // Disable the first item from Spinner
            // First item will be use for hint
            return position != 0
        }
    
        override fun getDropDownView(
            position: Int,
            convertView: View?,
            parent: ViewGroup
        ): View {
            val view: TextView = super.getDropDownView(position, convertView, parent) as TextView
            //set the color of first item in the drop down list to gray
            if(position == 0) {
                view.setTextColor(Color.GRAY)
            } else {
                //here is it possible to define color for other items by
                //view.setTextColor(Color.RED)
            }
            return view
        }
    
    }
    
  4. Set drop down view resource and attach the adapter to your spinner.

    spinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)     
    mySpinner.adapter = spinnerAdapter
    
  5. Change the color of the text in the spinner depending on the selected item

    mySpinner.onItemSelectedListener = object: AdapterView.OnItemSelectedListener{
        override fun onNothingSelected(parent: AdapterView<*>?) {
        }
    
        override fun onItemSelected(
            parent: AdapterView<*>?,
            view: View?,
            position: Int,
            id: Long
        ) {
            val value = parent!!.getItemAtPosition(position).toString()
            if(value == items[0]){
                (view as TextView).setTextColor(Color.GRAY)
            }
        }
    
    }
    

Characters allowed in a URL

I tested it by requesting my website (apache) with all available chars on my german keyboard as URL parameter:

http://example.com/?^1234567890ß´qwertzuiopü+asdfghjklöä#<yxcvbnm,.-°!"§$%&/()=? `QWERTZUIOPÜ*ASDFGHJKLÖÄ\'>YXCVBNM;:_²³{[]}\|µ@€~

These were not encoded:

^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ,.-!/()=?`*;:_{}[]\|~

Not encoded after urlencode():

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_

Not encoded after rawurlencode():

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_~

Note: Before PHP 5.3.0 rawurlencode() encoded ~ because of RFC 1738. But this was replaced by RFC 3986 so its safe to use, now. But I do not understand why for example {} are encoded through rawurlencode() because they are not mentioned in RFC 3986.

An additional test I made was regarding auto-linking in mail texts. I tested Mozilla Thunderbird, aol.com, outlook.com, gmail.com, gmx.de and yahoo.de and they fully linked URLs containing these chars:

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_~+#,%&=*;:@

Of course the ? was linked, too, but only if it was used once.

Some people would now suggest to use only the rawurlencode() chars, but did you ever hear that someone had problems to open these websites?

Asterisk
http://wayback.archive.org/web/*/http://google.com

Colon
https://en.wikipedia.org/wiki/Wikipedia:About

Plus
https://plus.google.com/+google

At sign, Colon, Comma and Exclamation mark
https://www.google.com/maps/place/USA/@36.2218457,...

Because of that these chars should be usable unencoded without problems. Of course you should not use &; because of encoding sequences like &amp;. The same reason is valid for % as it used to encode chars in general. And = as it assigns a value to a parameter name.

Finally I would say its ok to use these unencoded:

0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.-_~!+,*:@

But if you expect randomly generated URLs you should not use .!, because those mark the end of a sentence and some mail apps will not auto-link the last char of the url. Example:

Visit http://example.com/foo=bar! !

Returning a pointer to a vector element in c++

Returning &iterator will return the address of the iterator. If you want to return a way of referring to the element return the iterator itself.

Beware that you do not need the vector to be a global in order to return the iterator/pointer, but that operations in the vector can invalidate the iterator. Adding elements to the vector, for example, can move the vector elements to a different position if the new size() is greater than the reserved memory. Deletion of an element before the given item from the vector will make the iterator refer to a different element.

In both cases, depending on the STL implementation it can be hard to debug with just random errors happening each so often.

EDIT after comment: 'yes, I didn't want to return the iterator a) because its const, and b) surely it is only a local, temporary iterator? – Krakkos'

Iterators are not more or less local or temporary than any other variable and they are copyable. You can return it and the compiler will make the copy for you as it will with the pointer.

Now with the const-ness. If the caller wants to perform modifications through the returned element (whether pointer or iterator) then you should use a non-const iterator. (Just remove the 'const_' from the definition of the iterator).

Creating JSON on the fly with JObject

You can use the JObject.Parse operation and simply supply single quote delimited JSON text.

JObject  o = JObject.Parse(@"{
  'CPU': 'Intel',
  'Drives': [
    'DVD read/writer',
    '500 gigabyte hard drive'
  ]
}");

This has the nice benefit of actually being JSON and so it reads as JSON.

Or you have test data that is dynamic you can use JObject.FromObject operation and supply a inline object.

JObject o = JObject.FromObject(new
{
    channel = new
    {
        title = "James Newton-King",
        link = "http://james.newtonking.com",
        description = "James Newton-King's blog.",
        item =
            from p in posts
            orderby p.Title
            select new
            {
                title = p.Title,
                description = p.Description,
                link = p.Link,
                category = p.Categories
            }
    }
});

Json.net documentation for serialization

Java/ JUnit - AssertTrue vs AssertFalse

assertTrue will fail if the second parameter evaluates to false (in other words, it ensures that the value is true). assertFalse does the opposite.

assertTrue("This will succeed.", true);
assertTrue("This will fail!", false);

assertFalse("This will succeed.", false);
assertFalse("This will fail!", true);

As with many other things, the best way to become familiar with these methods is to just experiment :-).

Logical operator in a handlebars.js {{#if}} conditional

Improved solution that basically work with any binary operator (at least numbers, strings doesn't work well with eval, TAKE CARE OF POSSIBLE SCRIPT INJECTION IF USING A NON DEFINED OPERATOR WITH USER INPUTS):

Handlebars.registerHelper("ifCond",function(v1,operator,v2,options) {
    switch (operator)
    {
        case "==":
            return (v1==v2)?options.fn(this):options.inverse(this);

        case "!=":
            return (v1!=v2)?options.fn(this):options.inverse(this);

        case "===":
            return (v1===v2)?options.fn(this):options.inverse(this);

        case "!==":
            return (v1!==v2)?options.fn(this):options.inverse(this);

        case "&&":
            return (v1&&v2)?options.fn(this):options.inverse(this);

        case "||":
            return (v1||v2)?options.fn(this):options.inverse(this);

        case "<":
            return (v1<v2)?options.fn(this):options.inverse(this);

        case "<=":
            return (v1<=v2)?options.fn(this):options.inverse(this);

        case ">":
            return (v1>v2)?options.fn(this):options.inverse(this);

        case ">=":
         return (v1>=v2)?options.fn(this):options.inverse(this);

        default:
            return eval(""+v1+operator+v2)?options.fn(this):options.inverse(this);
    }
});

Fill DataTable from SQL Server database

Try with following:

public DataTable fillDataTable(string table)
    {
        string query = "SELECT * FROM dstut.dbo." +table;

        SqlConnection sqlConn = new SqlConnection(conSTR);
        sqlConn.Open();
        SqlCommand cmd = new SqlCommand(query, sqlConn);
        SqlDataAdapter da=new SqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);
        sqlConn.Close();
        return dt;
    }

Hope it is helpful.

How to update the value of a key in a dictionary in Python?

You are modifying the list book_shop.values()[i], which is not getting updated in the dictionary. Whenever you call the values() method, it will give you the values available in dictionary, and here you are not modifying the data of the dictionary.

Python Timezone conversion

Using pytz

from datetime import datetime
from pytz import timezone

fmt = "%Y-%m-%d %H:%M:%S %Z%z"
timezonelist = ['UTC','US/Pacific','Europe/Berlin']
for zone in timezonelist:

    now_time = datetime.now(timezone(zone))
    print now_time.strftime(fmt)

How do I choose the URL for my Spring Boot webapp?

As of spring boot 2 the server.contextPath property is deprecated. Instead you should use server.servlet.contextPath.

So in your application.properties file add:

server.servlet.contextPath=/myWebApp

For more details see: https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.0-Migration-Guide#servlet-specific-server-properties

How does Junit @Rule work?

Rules are used to add additional functionality which applies to all tests within a test class, but in a more generic way.

For instance, ExternalResource executes code before and after a test method, without having to use @Before and @After. Using an ExternalResource rather than @Before and @After gives opportunities for better code reuse; the same rule can be used from two different test classes.

The design was based upon: Interceptors in JUnit

For more information see JUnit wiki : Rules.

how to install Lex and Yacc in Ubuntu?

Use the synaptic packet manager in order to install yacc / lex. If you are feeling more comfortable doing this on the console just do:

sudo apt-get install bison flex

There are some very nice articles on the net on how to get started with those tools. I found the article from CodeProject to be quite good and helpful (see here). But you should just try and search for "introduction to lex", there are plenty of good articles showing up.

UITableViewCell, show delete button on swipe

Swift 4

func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
    let delete = UITableViewRowAction(style: .destructive, title: "delete") { (action, indexPath) in
        // delete item at indexPath
    tableView.deleteRows(at: [indexPath], with: .fade)

    }
    return [delete]
}

Change working directory in my current shell context when running Node script

Short answer: no (easy?) way, but you can do something that serves your purpose.

I've done a similar tool (a small command that, given a description of a project, sets environment, paths, directories, etc.). What I do is set-up everything and then spawn a shell with:

spawn('bash', ['-i'], {
  cwd: new_cwd,
  env: new_env,
  stdio: 'inherit'
});

After execution, you'll be on a shell with the new directory (and, in my case, environment). Of course you can change bash for whatever shell you prefer. The main differences with what you originally asked for are:

  • There is an additional process, so...
  • you have to write 'exit' to come back, and then...
  • after existing, all changes are undone.

However, for me, that differences are desirable.

Bootstrap select dropdown list placeholder

  1. in bootstrap-select.js Find title: null, and remove it.
  2. add title="YOUR TEXT" in <select> element.
  3. Fine :)

Example:

<select title="Please Choose one item">
    <option value="">A</option>
    <option value="">B</option>
    <option value="">C</option>
</select>

Moment.js - tomorrow, today and yesterday

I use a combination of add() and endOf() with moment

//...
const today = moment().endOf('day')
const tomorrow = moment().add(1, 'day').endOf('day')

if (date < today) return 'today'
if (date < tomorrow) return 'tomorrow'
return 'later'
//...

What are the calling conventions for UNIX & Linux system calls (and user-space functions) on i386 and x86-64

Further reading for any of the topics here: The Definitive Guide to Linux System Calls


I verified these using GNU Assembler (gas) on Linux.

Kernel Interface

x86-32 aka i386 Linux System Call convention:

In x86-32 parameters for Linux system call are passed using registers. %eax for syscall_number. %ebx, %ecx, %edx, %esi, %edi, %ebp are used for passing 6 parameters to system calls.

The return value is in %eax. All other registers (including EFLAGS) are preserved across the int $0x80.

I took following snippet from the Linux Assembly Tutorial but I'm doubtful about this. If any one can show an example, it would be great.

If there are more than six arguments, %ebx must contain the memory location where the list of arguments is stored - but don't worry about this because it's unlikely that you'll use a syscall with more than six arguments.

For an example and a little more reading, refer to http://www.int80h.org/bsdasm/#alternate-calling-convention. Another example of a Hello World for i386 Linux using int 0x80: Hello, world in assembly language with Linux system calls?

There is a faster way to make 32-bit system calls: using sysenter. The kernel maps a page of memory into every process (the vDSO), with the user-space side of the sysenter dance, which has to cooperate with the kernel for it to be able to find the return address. Arg to register mapping is the same as for int $0x80. You should normally call into the vDSO instead of using sysenter directly. (See The Definitive Guide to Linux System Calls for info on linking and calling into the vDSO, and for more info on sysenter, and everything else to do with system calls.)

x86-32 [Free|Open|Net|DragonFly]BSD UNIX System Call convention:

Parameters are passed on the stack. Push the parameters (last parameter pushed first) on to the stack. Then push an additional 32-bit of dummy data (Its not actually dummy data. refer to following link for more info) and then give a system call instruction int $0x80

http://www.int80h.org/bsdasm/#default-calling-convention


x86-64 Linux System Call convention:

(Note: x86-64 Mac OS X is similar but different from Linux. TODO: check what *BSD does)

Refer to section: "A.2 AMD64 Linux Kernel Conventions" of System V Application Binary Interface AMD64 Architecture Processor Supplement. The latest versions of the i386 and x86-64 System V psABIs can be found linked from this page in the ABI maintainer's repo. (See also the tag wiki for up-to-date ABI links and lots of other good stuff about x86 asm.)

Here is the snippet from this section:

  1. User-level applications use as integer registers for passing the sequence %rdi, %rsi, %rdx, %rcx, %r8 and %r9. The kernel interface uses %rdi, %rsi, %rdx, %r10, %r8 and %r9.
  2. A system-call is done via the syscall instruction. This clobbers %rcx and %r11 as well as the %rax return value, but other registers are preserved.
  3. The number of the syscall has to be passed in register %rax.
  4. System-calls are limited to six arguments, no argument is passed directly on the stack.
  5. Returning from the syscall, register %rax contains the result of the system-call. A value in the range between -4095 and -1 indicates an error, it is -errno.
  6. Only values of class INTEGER or class MEMORY are passed to the kernel.

Remember this is from the Linux-specific appendix to the ABI, and even for Linux it's informative not normative. (But it is in fact accurate.)

This 32-bit int $0x80 ABI is usable in 64-bit code (but highly not recommended). What happens if you use the 32-bit int 0x80 Linux ABI in 64-bit code? It still truncates its inputs to 32-bit, so it's unsuitable for pointers, and it zeros r8-r11.

User Interface: function calling

x86-32 Function Calling convention:

In x86-32 parameters were passed on stack. Last parameter was pushed first on to the stack until all parameters are done and then call instruction was executed. This is used for calling C library (libc) functions on Linux from assembly.

Modern versions of the i386 System V ABI (used on Linux) require 16-byte alignment of %esp before a call, like the x86-64 System V ABI has always required. Callees are allowed to assume that and use SSE 16-byte loads/stores that fault on unaligned. But historically, Linux only required 4-byte stack alignment, so it took extra work to reserve naturally-aligned space even for an 8-byte double or something.

Some other modern 32-bit systems still don't require more than 4 byte stack alignment.


x86-64 System V user-space Function Calling convention:

x86-64 System V passes args in registers, which is more efficient than i386 System V's stack args convention. It avoids the latency and extra instructions of storing args to memory (cache) and then loading them back again in the callee. This works well because there are more registers available, and is better for modern high-performance CPUs where latency and out-of-order execution matter. (The i386 ABI is very old).

In this new mechanism: First the parameters are divided into classes. The class of each parameter determines the manner in which it is passed to the called function.

For complete information refer to : "3.2 Function Calling Sequence" of System V Application Binary Interface AMD64 Architecture Processor Supplement which reads, in part:

Once arguments are classified, the registers get assigned (in left-to-right order) for passing as follows:

  1. If the class is MEMORY, pass the argument on the stack.
  2. If the class is INTEGER, the next available register of the sequence %rdi, %rsi, %rdx, %rcx, %r8 and %r9 is used

So %rdi, %rsi, %rdx, %rcx, %r8 and %r9 are the registers in order used to pass integer/pointer (i.e. INTEGER class) parameters to any libc function from assembly. %rdi is used for the first INTEGER parameter. %rsi for 2nd, %rdx for 3rd and so on. Then call instruction should be given. The stack (%rsp) must be 16B-aligned when call executes.

If there are more than 6 INTEGER parameters, the 7th INTEGER parameter and later are passed on the stack. (Caller pops, same as x86-32.)

The first 8 floating point args are passed in %xmm0-7, later on the stack. There are no call-preserved vector registers. (A function with a mix of FP and integer arguments can have more than 8 total register arguments.)

Variadic functions (like printf) always need %al = the number of FP register args.

There are rules for when to pack structs into registers (rdx:rax on return) vs. in memory. See the ABI for details, and check compiler output to make sure your code agrees with compilers about how something should be passed/returned.


Note that the Windows x64 function calling convention has multiple significant differences from x86-64 System V, like shadow space that must be reserved by the caller (instead of a red-zone), and call-preserved xmm6-xmm15. And very different rules for which arg goes in which register.

You are trying to add a non-nullable field 'new_field' to userprofile without a default

If the SSH it gives you 2 options, choose number 1, and put "None". Just that...for the moment.

how to open a page in new tab on button click in asp.net?

Add this Script  
<script type = "text/javascript">
 function SetTarget() {
     document.forms[0].target = "_blank";
 }
</script>
and 
<asp:Button ID="BTNpRINT"  runat="server" Text="PRINT"  CssClass="btn btn-primary"  OnClick="BTNpRINT_Click" OnClientClick = "SetTarget();"/>    
and 
protected void BTNpRINT_Click(object sender, EventArgs e)
    {
        Response.Redirect(string.Format("~/Print.aspx?ID={0}",txtInv.Text));
    }

How to change the integrated terminal in visual studio code or VSCode

For OP's terminal Cmder there is an integration guide, also hinted in the VS Code docs.

If you want to use VS Code tasks and encounter problems after switch to Cmder, there is an update to @khernand's answer. Copy this into your settings.json file:

"terminal.integrated.shell.windows": "cmd.exe",

"terminal.integrated.env.windows": {
  "CMDER_ROOT": "[cmder_root]" // replace [cmder_root] with your cmder path
},
"terminal.integrated.shellArgs.windows": [
  "/k",
  "%CMDER_ROOT%\\vendor\\bin\\vscode_init.cmd" // <-- this is the relevant change
  // OLD: "%CMDER_ROOT%\\vendor\\init.bat"
],

The invoked file will open Cmder as integrated terminal and switch to cmd for tasks - have a look at the source here. So you can omit configuring a separate terminal in tasks.json to make tasks work.

Starting with VS Code 1.38, there is also "terminal.integrated.automationShell.windows" setting, which lets you set your terminal for tasks globally and avoids issues with Cmder.

"terminal.integrated.automationShell.windows": "cmd.exe"

How can I iterate over the elements in Hashmap?

You should not map score to player. You should map player (or his name) to score:

Map<Player, Integer> player2score = new HashMap<Player, Integer>();

Then add players to map: int score = .... Player player = new Player(); player.setName("John"); // etc. player2score.put(player, score);

In this case the task is trivial:

int score = player2score.get(player);

How does it work - requestLocationUpdates() + LocationRequest/Listener

I use this one:

LocationManager.requestLocationUpdates(String provider, long minTime, float minDistance, LocationListener listener)

For example, using a 1s interval:

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000,0,this);

the time is in milliseconds, the distance is in meters.

This automatically calls:

public void onLocationChanged(Location location) {
    //Code here, location.getAccuracy(), location.getLongitude() etc...
}

I also had these included in the script but didnt actually use them:

public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}

In short:

public class GPSClass implements LocationListener {

    public void onLocationChanged(Location location) {
        // Called when a new location is found by the network location provider.
        Log.i("Message: ","Location changed, " + location.getAccuracy() + " , " + location.getLatitude()+ "," + location.getLongitude());
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {}
    public void onProviderEnabled(String provider) {}
    public void onProviderDisabled(String provider) {}

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000,0,this);
    }
}

Get month name from Date

I have a partial solution that I came up with. It uses a regular expression to extract the month and day name. But as I look through the Region and Language options (Windows) I realize that different cultures have different format order... maybe a better regular expression pattern could be useful.

function testDateInfo() {
        var months = new Array();
        var days = new Array();
        var workingDate = new Date();
        workingDate.setHours(0, 0, 0, 0);
        workingDate.setDate(1);
        var RE = new RegExp("([a-z]+)","ig");
        //-- get day names 0-6
        for (var i = 0; i < 7; i++) {

            var day = workingDate.getDay();
            //-- will eventually be in order
            if (days[day] == undefined)
                days[day] = workingDate.toLocaleDateString().match(RE)[0];
            workingDate.setDate(workingDate.getDate() + 1);
        }
        //--get month names 0-11
        for (var i = 0; i < 12; i++) {
            workingDate.setMonth(i);
            months.push(workingDate.toLocaleDateString().match(RE)[1]);
        }
        alert(days.join(",") + " \n\r " + months.join(","));
    }

Python variables as keys to dict

for i in ('apple', 'banana', 'carrot'):
    fruitdict[i] = locals()[i]

How to make a simple collection view with Swift

UICollectionView is same as UITableView but it gives us the additional functionality of simply creating a grid view, which is a bit problematic in UITableView. It will be a very long post I mention a link from where you will get everything in simple steps.

How do you set autocommit in an SQL Server session?

You can turn autocommit ON by setting implicit_transactions OFF:

SET IMPLICIT_TRANSACTIONS OFF

When the setting is ON, it returns to implicit transaction mode. In implicit transaction mode, every change you make starts a transactions which you have to commit manually.

Maybe an example is clearer. This will write a change to the database:

SET IMPLICIT_TRANSACTIONS ON
UPDATE MyTable SET MyField = 1 WHERE MyId = 1
COMMIT TRANSACTION

This will not write a change to the database:

SET IMPLICIT_TRANSACTIONS ON
UPDATE MyTable SET MyField = 1 WHERE MyId = 1
ROLLBACK TRANSACTION

The following example will update a row, and then complain that there's no transaction to commit:

SET IMPLICIT_TRANSACTIONS OFF
UPDATE MyTable SET MyField = 1 WHERE MyId = 1
ROLLBACK TRANSACTION

Like Mitch Wheat said, autocommit is the default for Sql Server 2000 and up.

HTML5 Canvas Resize (Downscale) Image High Quality?

Since your problem is to downscale your image, there is no point in talking about interpolation -which is about creating pixel-. The issue here is downsampling.

To downsample an image, we need to turn each square of p * p pixels in the original image into a single pixel in the destination image.

For performances reasons Browsers do a very simple downsampling : to build the smaller image, they will just pick ONE pixel in the source and use its value for the destination. which 'forgets' some details and adds noise.

Yet there's an exception to that : since the 2X image downsampling is very simple to compute (average 4 pixels to make one) and is used for retina/HiDPI pixels, this case is handled properly -the Browser does make use of 4 pixels to make one-.

BUT... if you use several time a 2X downsampling, you'll face the issue that the successive rounding errors will add too much noise.
What's worse, you won't always resize by a power of two, and resizing to the nearest power + a last resizing is very noisy.

What you seek is a pixel-perfect downsampling, that is : a re-sampling of the image that will take all input pixels into account -whatever the scale-.
To do that we must compute, for each input pixel, its contribution to one, two, or four destination pixels depending wether the scaled projection of the input pixels is right inside a destination pixels, overlaps an X border, an Y border, or both.
( A scheme would be nice here, but i don't have one. )

Here's an example of canvas scale vs my pixel perfect scale on a 1/3 scale of a zombat.

Notice that the picture might get scaled in your Browser, and is .jpegized by S.O..
Yet we see that there's much less noise especially in the grass behind the wombat, and the branches on its right. The noise in the fur makes it more contrasted, but it looks like he's got white hairs -unlike source picture-.
Right image is less catchy but definitively nicer.

enter image description here

Here's the code to do the pixel perfect downscaling :

fiddle result : http://jsfiddle.net/gamealchemist/r6aVp/embedded/result/
fiddle itself : http://jsfiddle.net/gamealchemist/r6aVp/

// scales the image by (float) scale < 1
// returns a canvas containing the scaled image.
function downScaleImage(img, scale) {
    var imgCV = document.createElement('canvas');
    imgCV.width = img.width;
    imgCV.height = img.height;
    var imgCtx = imgCV.getContext('2d');
    imgCtx.drawImage(img, 0, 0);
    return downScaleCanvas(imgCV, scale);
}

// scales the canvas by (float) scale < 1
// returns a new canvas containing the scaled image.
function downScaleCanvas(cv, scale) {
    if (!(scale < 1) || !(scale > 0)) throw ('scale must be a positive number <1 ');
    var sqScale = scale * scale; // square scale = area of source pixel within target
    var sw = cv.width; // source image width
    var sh = cv.height; // source image height
    var tw = Math.floor(sw * scale); // target image width
    var th = Math.floor(sh * scale); // target image height
    var sx = 0, sy = 0, sIndex = 0; // source x,y, index within source array
    var tx = 0, ty = 0, yIndex = 0, tIndex = 0; // target x,y, x,y index within target array
    var tX = 0, tY = 0; // rounded tx, ty
    var w = 0, nw = 0, wx = 0, nwx = 0, wy = 0, nwy = 0; // weight / next weight x / y
    // weight is weight of current source point within target.
    // next weight is weight of current source point within next target's point.
    var crossX = false; // does scaled px cross its current px right border ?
    var crossY = false; // does scaled px cross its current px bottom border ?
    var sBuffer = cv.getContext('2d').
    getImageData(0, 0, sw, sh).data; // source buffer 8 bit rgba
    var tBuffer = new Float32Array(3 * tw * th); // target buffer Float32 rgb
    var sR = 0, sG = 0,  sB = 0; // source's current point r,g,b
    /* untested !
    var sA = 0;  //source alpha  */    

    for (sy = 0; sy < sh; sy++) {
        ty = sy * scale; // y src position within target
        tY = 0 | ty;     // rounded : target pixel's y
        yIndex = 3 * tY * tw;  // line index within target array
        crossY = (tY != (0 | ty + scale)); 
        if (crossY) { // if pixel is crossing botton target pixel
            wy = (tY + 1 - ty); // weight of point within target pixel
            nwy = (ty + scale - tY - 1); // ... within y+1 target pixel
        }
        for (sx = 0; sx < sw; sx++, sIndex += 4) {
            tx = sx * scale; // x src position within target
            tX = 0 |  tx;    // rounded : target pixel's x
            tIndex = yIndex + tX * 3; // target pixel index within target array
            crossX = (tX != (0 | tx + scale));
            if (crossX) { // if pixel is crossing target pixel's right
                wx = (tX + 1 - tx); // weight of point within target pixel
                nwx = (tx + scale - tX - 1); // ... within x+1 target pixel
            }
            sR = sBuffer[sIndex    ];   // retrieving r,g,b for curr src px.
            sG = sBuffer[sIndex + 1];
            sB = sBuffer[sIndex + 2];

            /* !! untested : handling alpha !!
               sA = sBuffer[sIndex + 3];
               if (!sA) continue;
               if (sA != 0xFF) {
                   sR = (sR * sA) >> 8;  // or use /256 instead ??
                   sG = (sG * sA) >> 8;
                   sB = (sB * sA) >> 8;
               }
            */
            if (!crossX && !crossY) { // pixel does not cross
                // just add components weighted by squared scale.
                tBuffer[tIndex    ] += sR * sqScale;
                tBuffer[tIndex + 1] += sG * sqScale;
                tBuffer[tIndex + 2] += sB * sqScale;
            } else if (crossX && !crossY) { // cross on X only
                w = wx * scale;
                // add weighted component for current px
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // add weighted component for next (tX+1) px                
                nw = nwx * scale
                tBuffer[tIndex + 3] += sR * nw;
                tBuffer[tIndex + 4] += sG * nw;
                tBuffer[tIndex + 5] += sB * nw;
            } else if (crossY && !crossX) { // cross on Y only
                w = wy * scale;
                // add weighted component for current px
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // add weighted component for next (tY+1) px                
                nw = nwy * scale
                tBuffer[tIndex + 3 * tw    ] += sR * nw;
                tBuffer[tIndex + 3 * tw + 1] += sG * nw;
                tBuffer[tIndex + 3 * tw + 2] += sB * nw;
            } else { // crosses both x and y : four target points involved
                // add weighted component for current px
                w = wx * wy;
                tBuffer[tIndex    ] += sR * w;
                tBuffer[tIndex + 1] += sG * w;
                tBuffer[tIndex + 2] += sB * w;
                // for tX + 1; tY px
                nw = nwx * wy;
                tBuffer[tIndex + 3] += sR * nw;
                tBuffer[tIndex + 4] += sG * nw;
                tBuffer[tIndex + 5] += sB * nw;
                // for tX ; tY + 1 px
                nw = wx * nwy;
                tBuffer[tIndex + 3 * tw    ] += sR * nw;
                tBuffer[tIndex + 3 * tw + 1] += sG * nw;
                tBuffer[tIndex + 3 * tw + 2] += sB * nw;
                // for tX + 1 ; tY +1 px
                nw = nwx * nwy;
                tBuffer[tIndex + 3 * tw + 3] += sR * nw;
                tBuffer[tIndex + 3 * tw + 4] += sG * nw;
                tBuffer[tIndex + 3 * tw + 5] += sB * nw;
            }
        } // end for sx 
    } // end for sy

    // create result canvas
    var resCV = document.createElement('canvas');
    resCV.width = tw;
    resCV.height = th;
    var resCtx = resCV.getContext('2d');
    var imgRes = resCtx.getImageData(0, 0, tw, th);
    var tByteBuffer = imgRes.data;
    // convert float32 array into a UInt8Clamped Array
    var pxIndex = 0; //  
    for (sIndex = 0, tIndex = 0; pxIndex < tw * th; sIndex += 3, tIndex += 4, pxIndex++) {
        tByteBuffer[tIndex] = Math.ceil(tBuffer[sIndex]);
        tByteBuffer[tIndex + 1] = Math.ceil(tBuffer[sIndex + 1]);
        tByteBuffer[tIndex + 2] = Math.ceil(tBuffer[sIndex + 2]);
        tByteBuffer[tIndex + 3] = 255;
    }
    // writing result to canvas.
    resCtx.putImageData(imgRes, 0, 0);
    return resCV;
}

It is quite memory greedy, since a float buffer is required to store the intermediate values of the destination image (-> if we count the result canvas, we use 6 times the source image's memory in this algorithm).
It is also quite expensive, since each source pixel is used whatever the destination size, and we have to pay for the getImageData / putImageDate, quite slow also.
But there's no way to be faster than process each source value in this case, and situation is not that bad : For my 740 * 556 image of a wombat, processing takes between 30 and 40 ms.

subtract time from date - moment js

There is a simple function subtract which moment library gives us to subtract time from some time. Using it is also very simple.

moment(Date.now()).subtract(7, 'days'); // This will subtract 7 days from current time
moment(Date.now()).subtract(3, 'd'); // This will subtract 3 days from current time

//You can do this for days, years, months, hours, minutes, seconds
//You can also subtract multiple things simulatneously

//You can chain it like this.
moment(Date.now()).subtract(3, 'd').subtract(5. 'h'); // This will subtract 3 days and 5 hours from current time

//You can also use it as object literal
moment(Date.now()).subtract({days:3, hours:5}); // This will subtract 3 days and 5 hours from current time

Hope this helps!

How do I convert an object to an array?

Single-dimensional arrays

For converting single-dimension arrays, you can cast using (array) or there's get_object_vars, which Benoit mentioned in his answer.

// Cast to an array
$array = (array) $object;
// get_object_vars
$array = get_object_vars($object);

They work slightly different from each other. For example, get_object_vars will return an array with only publicly accessible properties unless it is called from within the scope of the object you're passing (ie in a member function of the object). (array), on the other hand, will cast to an array with all public, private and protected members intact on the array, though all public now, of course.

Multi-dimensional arrays

A somewhat dirty method is to use PHP >= 5.2's native JSON functions to encode to JSON and then decode back to an array. This will not include private and protected members, however, and is not suitable for objects that contain data that cannot be JSON encoded (such as binary data).

// The second parameter of json_decode forces parsing into an associative array
$array = json_decode(json_encode($object), true);

Alternatively, the following function will convert from an object to an array including private and protected members, taken from here and modified to use casting:

function objectToArray ($object) {
    if(!is_object($object) && !is_array($object))
        return $object;

    return array_map('objectToArray', (array) $object);
}

Where is the itoa function in Linux?

Where is the itoa function in Linux?

There is no such function in Linux. I use this code instead.

/*
=============
itoa

Convert integer to string

PARAMS:
- value     A 64-bit number to convert
- str       Destination buffer; should be 66 characters long for radix2, 24 - radix8, 22 - radix10, 18 - radix16.
- radix     Radix must be in range -36 .. 36. Negative values used for signed numbers.
=============
*/

char* itoa (unsigned long long  value,  char str[],  int radix)
{
    char        buf [66];
    char*       dest = buf + sizeof(buf);
    boolean     sign = false;

    if (value == 0) {
        memcpy (str, "0", 2);
        return str;
    }

    if (radix < 0) {
        radix = -radix;
        if ( (long long) value < 0) {
            value = -value;
            sign = true;
        }
    }

    *--dest = '\0';

    switch (radix)
    {
    case 16:
        while (value) {
            * --dest = '0' + (value & 0xF);
            if (*dest > '9') *dest += 'A' - '9' - 1;
            value >>= 4;
        }
        break;
    case 10:
        while (value) {
            *--dest = '0' + (value % 10);
            value /= 10;
        }
        break;

    case 8:
        while (value) {
            *--dest = '0' + (value & 7);
            value >>= 3;
        }
        break;

    case 2:
        while (value) {
            *--dest = '0' + (value & 1);
            value >>= 1;
        }
        break;

    default:            // The slow version, but universal
        while (value) {
            *--dest = '0' + (value % radix);
            if (*dest > '9') *dest += 'A' - '9' - 1;
            value /= radix;
        }
        break;
    }

    if (sign) *--dest = '-';

    memcpy (str, dest, buf +sizeof(buf) - dest);
    return str;
}

How do I force files to open in the browser instead of downloading (PDF)?

The correct type is application/pdf for PDF, not application/force-download. This looks like a hack for some legacy browsers. Always use the correct mimetype if you can.

If you have control over the server code:

  • Forced download/prompt: use header("Content-Disposition", "attachment; filename=myfilename.myextension");
  • Browser tries to open it: use header("Content-Disposition", "inline; filename=myfilename.myextension");

No control over the server code:

NOTE: I prefer setting the filename on the server side as you may have more information and can use common code.

Get Excel sheet name and use as variable in macro

in a Visual Basic Macro you would use

pName = ActiveWorkbook.Path      ' the path of the currently active file
wbName = ActiveWorkbook.Name     ' the file name of the currently active file
shtName = ActiveSheet.Name       ' the name of the currently selected worksheet

The first sheet in a workbook can be referenced by

ActiveWorkbook.Worksheets(1)

so after deleting the [Report] tab you would use

ActiveWorkbook.Worksheets("Report").Delete
shtName = ActiveWorkbook.Worksheets(1).Name

to "work on that sheet later on" you can create a range object like

Dim MySheet as Range
MySheet = ActiveWorkbook.Worksheets(shtName).[A1]

and continue working on MySheet(rowNum, colNum) etc. ...

shortcut creation of a range object without defining shtName:

Dim MySheet as Range
MySheet = ActiveWorkbook.Worksheets(1).[A1]

Why can't I use the 'await' operator within the body of a lock statement?

Use SemaphoreSlim.WaitAsync method.

 await mySemaphoreSlim.WaitAsync();
 try {
     await Stuff();
 } finally {
     mySemaphoreSlim.Release();
 }

PHP, display image with Header()

Browsers make their best guess with the data they receive. This works for markup (which Websites often get wrong) and other media content. A program that receives a file can often figure out what its received regardless of the MIME content type it's been told.

This isn't something you should rely on however. It's recommended you always use the correct MIME content.

Does C# have extension properties?

For the moment it is still not supported out of the box by Roslyn compiler ...

Until now, the extension properties were not seen as valuable enough to be included in the previous versions of C# standard. C# 7 and C# 8.0 have seen this as proposal champion but it wasn't released yet, most of all because even if there is already an implementation, they want to make it right from the start.

But it will ...

There is an extension members item in the C# 7 work list so it may be supported in the near future. The current status of extension property can be found on Github under the related item.

However, there is an even more promising topic which is the "extend everything" with a focus on especially properties and static classes or even fields.

Moreover you can use a workaround

As specified in this article, you can use the TypeDescriptor capability to attach an attribute to an object instance at runtime. However, it is not using the syntax of the standard properties.
It's a little bit different from just syntactic sugar adding a possibility to define an extended property like
string Data(this MyClass instance) as an alias for extension method
string GetData(this MyClass instance) as it stores data into the class.

I hope that C#7 will provide a full featured extension everything (properties and fields), however on that point, only time will tell.

And feel free to contribute as the software of tomorrow will come from the community.

Update: August 2016

As dotnet team published what's new in C# 7.0 and from a comment of Mads Torgensen:

Extension properties: we had a (brilliant!) intern implement them over the summer as an experiment, along with other kinds of extension members. We remain interested in this, but it’s a big change and we need to feel confident that it’s worth it.

It seems that extension properties and other members, are still good candidates to be included in a future release of Roslyn, but maybe not the 7.0 one.

Update: May 2017

The extension members has been closed as duplicate of extension everything issue which is closed too. The main discussion was in fact about Type extensibility in a broad sense. The feature is now tracked here as a proposal and has been removed from 7.0 milestone.

Update: August, 2017 - C# 8.0 proposed feature

While it still remains only a proposed feature, we have now a clearer view of what would be its syntax. Keep in mind that this will be the new syntax for extension methods as well:

public interface IEmployee 
{
    public decimal Salary { get; set; }
}

public class Employee
{
    public decimal Salary { get; set; }
}

public extension MyPersonExtension extends Person : IEmployee
{
    private static readonly ConditionalWeakTable<Person, Employee> _employees = 
        new ConditionalWeakTable<Person, Employee>();


    public decimal Salary
    {
        get 
        {
            // `this` is the instance of Person
            return _employees.GetOrCreate(this).Salary; 
        }
        set 
        {
            Employee employee = null;
            if (!_employees.TryGetValue(this, out employee)
            {
                employee = _employees.GetOrCreate(this);
            }
            employee.Salary = value;
        }
    }
}

IEmployee person = new Person();
var salary = person.Salary;

Similar to partial classes, but compiled as a separate class/type in a different assembly. Note you will also be able to add static members and operators this way. As mentioned in Mads Torgensen podcast, the extension won't have any state (so it cannot add private instance members to the class) which means you won't be able to add private instance data linked to the instance. The reason invoked for that is it would imply to manage internally dictionaries and it could be difficult (memory management, etc...). For this, you can still use the TypeDescriptor/ConditionalWeakTable technique described earlier and with the property extension, hides it under a nice property.

Syntax is still subject to change as implies this issue. For example, extends could be replaced by for which some may feel more natural and less java related.

Update December 2018 - Roles, Extensions and static interface members

Extension everything didn't make it to C# 8.0, because of some of drawbacks explained as the end of this GitHub ticket. So, there was an exploration to improve the design. Here, Mads Torgensen explains what are roles and extensions and how they differs:

Roles allow interfaces to be implemented on specific values of a given type. Extensions allow interfaces to be implemented on all values of a given type, within a specific region of code.

It can be seen at a split of previous proposal in two use cases. The new syntax for extension would be like this:

public extension ULongEnumerable of ulong
{
    public IEnumerator<byte> GetEnumerator()
    {
        for (int i = sizeof(ulong); i > 0; i--)
        {
            yield return unchecked((byte)(this >> (i-1)*8));
        }
    }
}

then you would be able to do this:

foreach (byte b in 0x_3A_9E_F1_C5_DA_F7_30_16ul)
{
    WriteLine($"{e.Current:X}");
}

And for a static interface:

public interface IMonoid<T> where T : IMonoid<T>
{
    static T operator +(T t1, T t2);
    static T Zero { get; }
}

Add an extension property on int and treat the int as IMonoid<int>:

public extension IntMonoid of int : IMonoid<int>
{
    public static int Zero => 0;
}

UITableView Separator line

Here is an alternate way to add a custom separator line to a UITableView by making a CALayer for the image and using that as the separator line.

// make a CALayer for the image for the separator line

CALayer *separator = [CALayer layer];
separator.contents = (id)[UIImage imageNamed:@"myImage.png"].CGImage;
separator.frame = CGRectMake(0, 54, self.view.frame.size.width, 2);
[cell.layer addSublayer:separator];

Slide right to left Android Animations

See this link.. you can see so many kinds of animations here, just copy the xml to your res/anim folder and use it like the following..

listView.setAnimation(AnimationUtils.loadAnimation(MainActivity.this,R.anim.slide_in_right));

Animation Lists

conflicting types for 'outchar'

In C, the order that you define things often matters. Either move the definition of outchar to the top, or provide a prototype at the top, like this:

#include <stdio.h> #include <stdlib.h>  void outchar(char ch);  int main() {     outchar('A');     outchar('B');     outchar('C');     return 0; }  void outchar(char ch) {     printf("%c", ch); } 

Also, you should be specifying the return type of every function. I added that for you.

How to get exception message in Python properly

If you look at the documentation for the built-in errors, you'll see that most Exception classes assign their first argument as a message attribute. Not all of them do though.

Notably,EnvironmentError (with subclasses IOError and OSError) has a first argument of errno, second of strerror. There is no message... strerror is roughly analogous to what would normally be a message.

More generally, subclasses of Exception can do whatever they want. They may or may not have a message attribute. Future built-in Exceptions may not have a message attribute. Any Exception subclass imported from third-party libraries or user code may not have a message attribute.

I think the proper way of handling this is to identify the specific Exception subclasses you want to catch, and then catch only those instead of everything with an except Exception, then utilize whatever attributes that specific subclass defines however you want.

If you must print something, I think that printing the caught Exception itself is most likely to do what you want, whether it has a message attribute or not.

You could also check for the message attribute if you wanted, like this, but I wouldn't really suggest it as it just seems messy:

try:
    pass
except Exception as e:
    # Just print(e) is cleaner and more likely what you want,
    # but if you insist on printing message specifically whenever possible...
    if hasattr(e, 'message'):
        print(e.message)
    else:
        print(e)

How are cookies passed in the HTTP protocol?

The server sends the following in its response header to set a cookie field.

Set-Cookie:name=value

If there is a cookie set, then the browser sends the following in its request header.

Cookie:name=value

See the HTTP Cookie article at Wikipedia for more information.

Windows equivalent of 'touch' (i.e. the node.js way to create an index.html)

If you have Cygwin installed in your PC, you can simply use the supplied executable for touch (also via windows command prompt):

C:\cygwin64\bin\touch.exe <file_path>

How to list all the files in a commit?

Display the log.

COMMIT can be blank ("") or the sha-1 or the sha-1 shortened.

git log COMMIT -1 --name-only

This will list just the files, very useful for further processing.

git log COMMIT -1 --name-only --pretty=format:"" | grep "[^\s]"

typedef struct vs struct definitions

In C (not C++), you have to declare struct variables like:

struct myStruct myVariable;

In order to be able to use myStruct myVariable; instead, you can typedef the struct:

typedef struct myStruct someStruct;
someStruct myVariable;

You can combine struct definition and typedefs it in a single statement which declares an anonymous struct and typedefs it.

typedef struct { ... } myStruct;

how to access the command line for xampp on windows

Xampp has the php application under: C:\xampp\php file directory ... if you input C:\xampp\php\php in CMD it should enter the php application.

Convert sqlalchemy row object to python dict

You could try to do it in this way.

for u in session.query(User).all():
    print(u._asdict())

It use a built-in method in the query object that return a dictonary object of the query object.

references: https://docs.sqlalchemy.org/en/latest/orm/query.html

How to export private key from a keystore of self-signed certificate

http://anandsekar.github.io/exporting-the-private-key-from-a-jks-keystore/

public class ExportPrivateKey {
        private File keystoreFile;
        private String keyStoreType;
        private char[] password;
        private String alias;
        private File exportedFile;

        public static KeyPair getPrivateKey(KeyStore keystore, String alias, char[] password) {
                try {
                        Key key=keystore.getKey(alias,password);
                        if(key instanceof PrivateKey) {
                                Certificate cert=keystore.getCertificate(alias);
                                PublicKey publicKey=cert.getPublicKey();
                                return new KeyPair(publicKey,(PrivateKey)key);
                        }
                } catch (UnrecoverableKeyException e) {
        } catch (NoSuchAlgorithmException e) {
        } catch (KeyStoreException e) {
        }
        return null;
        }

        public void export() throws Exception{
                KeyStore keystore=KeyStore.getInstance(keyStoreType);
                BASE64Encoder encoder=new BASE64Encoder();
                keystore.load(new FileInputStream(keystoreFile),password);
                KeyPair keyPair=getPrivateKey(keystore,alias,password);
                PrivateKey privateKey=keyPair.getPrivate();
                String encoded=encoder.encode(privateKey.getEncoded());
                FileWriter fw=new FileWriter(exportedFile);
                fw.write(“—–BEGIN PRIVATE KEY—–\n“);
                fw.write(encoded);
                fw.write(“\n“);
                fw.write(“—–END PRIVATE KEY—–”);
                fw.close();
        }


        public static void main(String args[]) throws Exception{
                ExportPrivateKey export=new ExportPrivateKey();
                export.keystoreFile=new File(args[0]);
                export.keyStoreType=args[1];
                export.password=args[2].toCharArray();
                export.alias=args[3];
                export.exportedFile=new File(args[4]);
                export.export();
        }
}

How to use ArrayAdapter<myClass>

I think this is the best approach. Using generic ArrayAdapter class and extends your own Object adapter is as simple as follows:

public abstract class GenericArrayAdapter<T> extends ArrayAdapter<T> {

  // Vars
  private LayoutInflater mInflater;

  public GenericArrayAdapter(Context context, ArrayList<T> objects) {
    super(context, 0, objects);
    init(context);
  }

  // Headers
  public abstract void drawText(TextView textView, T object);

  private void init(Context context) {
    this.mInflater = LayoutInflater.from(context);
  }

  @Override public View getView(int position, View convertView, ViewGroup parent) {
    final ViewHolder vh;
    if (convertView == null) {
      convertView = mInflater.inflate(android.R.layout.simple_list_item_1, parent, false);
      vh = new ViewHolder(convertView);
      convertView.setTag(vh);
    } else {
      vh = (ViewHolder) convertView.getTag();
    }

    drawText(vh.textView, getItem(position));

    return convertView;
  }

  static class ViewHolder {

    TextView textView;

    private ViewHolder(View rootView) {
      textView = (TextView) rootView.findViewById(android.R.id.text1);
    }
  }
}

and here your adapter (example):

public class SizeArrayAdapter extends GenericArrayAdapter<Size> {

  public SizeArrayAdapter(Context context, ArrayList<Size> objects) {
    super(context, objects);
  }

  @Override public void drawText(TextView textView, Size object) {
    textView.setText(object.getName());
  }

}

and finally, how to initialize it:

ArrayList<Size> sizes = getArguments().getParcelableArrayList(Constants.ARG_PRODUCT_SIZES);
SizeArrayAdapter sizeArrayAdapter = new SizeArrayAdapter(getActivity(), sizes);
listView.setAdapter(sizeArrayAdapter);

I've created a Gist with TextView layout gravity customizable ArrayAdapter:

https://gist.github.com/m3n0R/8822803

MySQL: Curdate() vs Now()

For questions like this, it is always worth taking a look in the manual first. Date and time functions in the mySQL manual

CURDATE() returns the DATE part of the current time. Manual on CURDATE()

NOW() returns the date and time portions as a timestamp in various formats, depending on how it was requested. Manual on NOW().

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

Image to Data:-

    if let img = UIImage(named: "xxx.png") {
        let pngdata = img.pngData()
    }

   if let img = UIImage(named: "xxx.jpeg") {
        let jpegdata = img.jpegData(compressionQuality: 1)
    }

Data to Image:-

 let image = UIImage(data: pngData)

Efficiently finding the last line in a text file

#!/usr/bin/python

count = 0

f = open('last_line1','r')

for line in f.readlines():

    line = line.strip()

    count = count + 1

    print line

print count

f.close()

count1 = 0

h = open('last_line1','r')

for line in h.readlines():

    line = line.strip()

    count1 = count1 + 1

    if count1 == count:

       print line         #-------------------- this is the last line

h.close()

Predefined type 'System.ValueTuple´2´ is not defined or imported

I had to check System.ValueTuple.dll file was under source control and correct its reference in .cssproj files:

  1. rightclick each project in solution
  2. unload project
  3. edit .cssproj file: change

< Reference Include="System.ValueTuple" >

< HintPath >

....\ProjectName\ProjectName\obj\Release\Package\PackageTmp\bin\System.ValueTuple.dll

< /HintPath >

< /Reference >

into

< Reference Include="System.ValueTuple" >

< HintPath >

..\packages\System.ValueTuple.4.4.0\lib\netstandard1.0\System.ValueTuple.dll

< /HintPath >

< /Reference >

  1. save changes and reload projects
  2. find System.ValueTuple.dll and save it into this folder
  3. add reference of this file into source control

(Optional): 7. solve same problems with another .dll files this way

How can I check if the current date/time is past a set date/time?

date_default_timezone_set('Asia/Kolkata');

$curDateTime = date("Y-m-d H:i:s");
$myDate = date("Y-m-d H:i:s", strtotime("2018-06-26 16:15:33"));
if($myDate < $curDateTime){
    echo "active";exit;
}else{
    echo "inactive";exit;
}

Concept behind putting wait(),notify() methods in Object class

wait - wait method tells the current thread to give up monitor and go to sleep.

notify - Wakes up a single thread that is waiting on this object's monitor.

So you see wait() and notify() methods work at the monitor level, thread which is currently holding the monitor is asked to give up that monitor through wait() method and through notify method (or notifyAll) threads which are waiting on the object's monitor are notified that threads can wake up.

Important point to note here is that monitor is assigned to an object not to a particular thread. That's one reason why these methods are in Object class. To reiterate threads wait on an Object's monitor (lock) and notify() is also called on an object to wake up a thread waiting on the Object's monitor.

Regex for numbers only

If you need to check if all the digits are number (0-9) or not,

^[0-9]+$

1425 TRUE

0142 TRUE

0 TRUE

1 TRUE

154a25 FALSE

1234=3254 FALSE

Make file echo displaying "$PATH" string

In the manual for GNU make, they talk about this specific example when describing the value function:

The value function provides a way for you to use the value of a variable without having it expanded. Please note that this does not undo expansions which have already occurred; for example if you create a simply expanded variable its value is expanded during the definition; in that case the value function will return the same result as using the variable directly.

The syntax of the value function is:

 $(value variable)

Note that variable is the name of a variable; not a reference to that variable. Therefore you would not normally use a ‘$’ or parentheses when writing it. (You can, however, use a variable reference in the name if you want the name not to be a constant.)

The result of this function is a string containing the value of variable, without any expansion occurring. For example, in this makefile:

 FOO = $PATH

 all:
         @echo $(FOO)
         @echo $(value FOO)

The first output line would be ATH, since the “$P” would be expanded as a make variable, while the second output line would be the current value of your $PATH environment variable, since the value function avoided the expansion.

PHPExcel auto size column width

This code snippet will auto size all the columns that contain data in all the sheets. There is no need to use the activeSheet getter and setter.

// In my case this line didn't make much of a difference
PHPExcel_Shared_Font::setAutoSizeMethod(PHPExcel_Shared_Font::AUTOSIZE_METHOD_EXACT);
// Iterating all the sheets
/** @var PHPExcel_Worksheet $sheet */
foreach ($objPHPExcel->getAllSheets() as $sheet) {
    // Iterating through all the columns
    // The after Z column problem is solved by using numeric columns; thanks to the columnIndexFromString method
    for ($col = 0; $col <= PHPExcel_Cell::columnIndexFromString($sheet->getHighestDataColumn()); $col++) {
        $sheet->getColumnDimensionByColumn($col)->setAutoSize(true);
    }
}

How to add multiple values to a dictionary key in python?

Make the value a list, e.g.

a["abc"] = [1, 2, "bob"]

UPDATE:

There are a couple of ways to add values to key, and to create a list if one isn't already there. I'll show one such method in little steps.

key = "somekey"
a.setdefault(key, [])
a[key].append(1)

Results:

>>> a
{'somekey': [1]}

Next, try:

key = "somekey"
a.setdefault(key, [])
a[key].append(2)

Results:

>>> a
{'somekey': [1, 2]}

The magic of setdefault is that it initializes the value for that key if that key is not defined, otherwise it does nothing. Now, noting that setdefault returns the key you can combine these into a single line:

a.setdefault("somekey",[]).append("bob")

Results:

>>> a
{'somekey': [1, 2, 'bob']}

You should look at the dict methods, in particular the get() method, and do some experiments to get comfortable with this.

Access an arbitrary element in a dictionary in Python

How about, this. Not mentioned here yet.

py 2 & 3

a = {"a":2,"b":3}
a[list(a)[0]] # the first element is here
>>> 2

MySQL and PHP - insert NULL rather than empty string

This works just fine for me:

INSERT INTO table VALUES ('', NULLIF('$date',''))

(first '' increments id field)

Session 'app' error while installing APK

I was using CyanogenMod 12.1 and was building with libgdx when I met with the same error. Rebuilding didn't work for me. My phone was connected as UMS or USB mass storage to my PC when I ran the app. Just changed the USB configuration from mass storage to MTP and it fixed my problem.

What is the difference between a var and val definition in Scala?

The difference is that a var can be re-assigned to whereas a val cannot. The mutability, or otherwise of whatever is actually assigned, is a side issue:

import collection.immutable
import collection.mutable
var m = immutable.Set("London", "Paris")
m = immutable.Set("New York") //Reassignment - I have change the "value" at m.

Whereas:

val n = immutable.Set("London", "Paris")
n = immutable.Set("New York") //Will not compile as n is a val.

And hence:

val n = mutable.Set("London", "Paris")
n = mutable.Set("New York") //Will not compile, even though the type of n is mutable.

If you are building a data structure and all of its fields are vals, then that data structure is therefore immutable, as its state cannot change.

Latex Multiple Linebreaks

You can use the setspace package which gives you spacing environments, e.g.:

\documentclass{article}
\usepackage{setspace}
\begin{document}
\doublespace
my line of text blah blah blah

new line of text with blank line between
\end{document}

Or use a verbatim environment to control the layout of your code precisely.

Blocking device rotation on mobile web pages

_x000D_
_x000D_
#rotate-device {_x000D_
    width: 100%;_x000D_
    height: 100%;_x000D_
    position: fixed;_x000D_
    z-index: 9999;_x000D_
    top: 0;_x000D_
    left: 0;_x000D_
    background-color: #000;_x000D_
    background-image: url(/path to img/rotate.png);_x000D_
    background-size: 100px 100px;_x000D_
    background-position: center;_x000D_
    background-repeat: no-repeat;_x000D_
    display: none;_x000D_
}_x000D_
_x000D_
@media only screen and (max-device-width: 667px) and (min-device-width: 320px) and (orientation: landscape){_x000D_
 #rotate-device {_x000D_
  display: block;_x000D_
 }_x000D_
}
_x000D_
<div id="rotate-device"></div>
_x000D_
_x000D_
_x000D_

What is the difference between HTML tags <div> and <span>?

As mentioned in other answers, by default div will be rendered as a block element, while span will be rendered inline within its context. But neither has any semantic value; they exist to allow you to apply styling and an identity to any given bit of content. Using styles, you can make a div act like a span and vice-versa.

One of the useful styles for div is inline-block

Examples:

  1. http://dustwell.com/div-span-inline-block.html

  2. CSS display: inline vs inline-block

I have used inline-block to a great success, in game web projects.

Doing HTTP requests FROM Laravel to an external API

You just want to call an external URL and use the results? PHP does this out of the box, if we're talking about a simple GET request to something serving JSON:

$json = json_decode(file_get_contents('http://host.com/api/stuff/1'), true);

If you want to do a post request, it's a little harder but there's loads of examples how to do this with curl.

So I guess the question is; what exactly do you want?

Vue.js img src concatenate variable and text

In another case I'm able to use template literal ES6 with backticks, so for yours could be set as:

<img v-bind:src="`${imgPreUrl()}img/logo.png`">

CGContextDrawImage draws image upside down when passed UIImage.CGImage

Relevant Quartz2D docs: https://developer.apple.com/library/ios/documentation/2DDrawing/Conceptual/DrawingPrintingiOS/GraphicsDrawingOverview/GraphicsDrawingOverview.html#//apple_ref/doc/uid/TP40010156-CH14-SW4

Flipping the Default Coordinate System

Flipping in UIKit drawing modifies the backing CALayer to align a drawing environment having a LLO coordinate system with the default coordinate system of UIKit. If you only use UIKit methods and function for drawing, you shouldn’t need to flip the CTM. However, if you mix Core Graphics or Image I/O function calls with UIKit calls, flipping the CTM might be necessary.

Specifically, if you draw an image or PDF document by calling Core Graphics functions directly, the object is rendered upside-down in the view’s context. You must flip the CTM to display the image and pages correctly.

To flip a object drawn to a Core Graphics context so that it appears correctly when displayed in a UIKit view, you must modify the CTM in two steps. You translate the origin to the upper-left corner of the drawing area, and then you apply a scale translation, modifying the y-coordinate by -1. The code for doing this looks similar to the following:

CGContextSaveGState(graphicsContext);
CGContextTranslateCTM(graphicsContext, 0.0, imageHeight);
CGContextScaleCTM(graphicsContext, 1.0, -1.0);
CGContextDrawImage(graphicsContext, image, CGRectMake(0, 0, imageWidth, imageHeight));
CGContextRestoreGState(graphicsContext);

What are examples of TCP and UDP in real life?

TCP :

Transmission Control Protocol is a connection-oriented protocol, which means that it requires handshaking to set up end-to-end communications. Once a connection is set up, user data may be sent bi-directionally over the connection.

Reliable – Strictly only at transport layer, TCP manages message acknowledgment, retransmission and timeout. Multiple attempts to deliver the message are made. If it gets lost along the way, the server will re-request the lost part. In TCP, there's either no missing data, or, in case of multiple timeouts, the connection is dropped. (This reliability however does not cover application layer, at which a separate acknowledgement flow control is still necessary)

Ordered – If two messages are sent over a connection in sequence, the first message will reach the receiving application first. When data segments arrive in the wrong order, TCP buffers delay the out-of-order data until all data can be properly re-ordered and delivered to the application.

Heavyweight – TCP requires three packets to set up a socket connection, before any user data can be sent. TCP handles reliability and congestion control. Streaming – Data is read as a byte stream, no distinguishing indications are transmitted to signal message (segment) boundaries.

Applications of TCP

World Wide Web, email, remote administration, and file transfer rely on TCP.

UDP :

User Datagram Protocol is a simpler message-based connectionless protocol. Connectionless protocols do not set up a dedicated end-to-end connection. Communication is achieved by transmitting information in one direction from source to destination without verifying the readiness or state of the receiver.

Unreliable – When a UDP message is sent, it cannot be known if it will reach its destination; it could get lost along the way. There is no concept of acknowledgment, retransmission, or timeout.

Not ordered – If two messages are sent to the same recipient, the order in which they arrive cannot be predicted.

Lightweight – There is no ordering of messages, no tracking connections, etc. It is a small transport layer designed on top of IP.

Datagrams – Packets are sent individually and are checked for integrity only if they arrive. Packets have definite boundaries which are honored upon receipt, meaning a read operation at the receiver socket will yield an entire message as it was originally sent. No congestion control – UDP itself does not avoid congestion. Congestion control measures must be implemented at the application level.

Broadcasts – being connectionless, UDP can broadcast - sent packets can be addressed to be receivable by all devices on the subnet.

Multicast – a multicast mode of operation is supported whereby a single datagram packet can be automatically routed without duplication to very large numbers of subscribers.

Applications of UDP

Numerous key Internet applications use UDP, including: the Domain Name System (DNS), where queries must be fast and only consist of a single request followed by a single reply packet, the Simple Network Management Protocol (SNMP), the Routing Information Protocol (RIP) and the Dynamic Host Configuration Protocol (DHCP).

Voice and video traffic is generally transmitted using UDP. Real-time video and audio streaming protocols are designed to handle occasional lost packets, so only slight degradation in quality occurs, rather than large delays if lost packets were retransmitted. Because both TCP and UDP run over the same network, many businesses are finding that a recent increase in UDP traffic from these real-time applications is hindering the performance of applications using TCP, such as point of sale, accounting, and database systems. When TCP detects packet loss, it will throttle back its data rate usage. Since both real-time and business applications are important to businesses, developing quality of service solutions is seen as crucial by some.

Some VPN systems such as OpenVPN may use UDP while implementing reliable connections and error checking at the application level.

Finding the type of an object in C++

This is called RTTI, but you almost surely want to reconsider your design here, because finding the type and doing special things based on it makes your code more brittle.

How to set 00:00:00 using moment.js

var time = moment().toDate();  // This will return a copy of the Date that the moment uses

time.setHours(0);
time.setMinutes(0);
time.setSeconds(0);
time.setMilliseconds(0);

What's wrong with overridable method calls in constructors?

Invoking an overridable method in the constructor allows subclasses to subvert the code, so you can't guarantee that it works anymore. That's why you get a warning.

In your example, what happens if a subclass overrides getTitle() and returns null ?

To "fix" this, you can use a factory method instead of a constructor, it's a common pattern of objects instanciation.

Can you have a <span> within a <span>?

Yes. You can have a span within a span. Your problem stems from something else.

CSS scale down image to fit in containing div, without specifing original size

Hope this will answer the age old problem (Without using CSS background property)

Html

<div class="card-cont">
 <img src="demo.png" />
</div>

Css

.card-cont{
  width:100%;
  height:150px;
}

.card-cont img{
  max-width: 100%;
  min-width: 100%;
  min-height: 150px;
}

How to set a Javascript object values dynamically?

myObj[prop] = value;

That should work. You mixed up the name of the variable and its value. But indexing an object with strings to get at its properties works fine in JavaScript.

Adding minutes to date time in PHP

I don't know why the approach set as solution didn't work for me. So I'm posting here what worked for me in hope it can help anybody:

$startTime = date("Y-m-d H:i:s");

//display the starting time
echo '> '.$startTime . "<br>";

//adding 2 minutes
$convertedTime = date('Y-m-d H:i:s', strtotime('+2 minutes', strtotime($startTime)));

//display the converted time
echo '> '.$convertedTime;

How to convert an OrderedDict into a regular dict in python3

A version that handles nested dictionaries and iterables but does not use the json module. Nested dictionaries become dict, nested iterables become list, everything else is returned unchanged (including dictionary keys and strings/bytes/bytearrays).

def recursive_to_dict(obj):
    try:
        if hasattr(obj, "split"):    # is string-like
            return obj
        elif hasattr(obj, "items"):  # is dict-like
            return {k: recursive_to_dict(v) for k, v in obj.items()}
        else:                        # is iterable
            return [recursive_to_dict(e) for e in obj]
    except TypeError:                # return everything else
        return obj

Returning string from C function

Your pointer is pointing to local variable of the function. So as soon as you return from the function, memory gets deallocated. You have to assign memory on heap in order to use it in other functions.

Instead char *rtnPtr = word;

do this char *rtnPtr = malloc(length);

So that it is available in the main function. After it is used free the memory.

Getting the HTTP Referrer in ASP.NET

Request.Headers["Referer"]

Explanation

The Request.UrlReferer property will throw a System.UriFormatException if the referer HTTP header is malformed (which can happen since it is not usually under your control).

Therefore, the Request.UrlReferer property is not 100% reliable - it may contain data that cannot be parsed into a Uri class. To ensure the value is always readable, use Request.Headers["Referrer"] instead.

As for using Request.ServerVariables as others here have suggested, per MSDN:

Request.ServerVariables Collection

The ServerVariables collection retrieves the values of predetermined environment variables and request header information.

Request.Headers Property

Gets a collection of HTTP headers.

Request.Headers is a better choice than Request.ServerVariables, since Request.ServerVariables contains all of the environment variables as well as the headers, where Request.Headers is a much shorter list that only contains the headers.

So the most reliable solution is to use the Request.Headers collection to read the value directly. Do heed Microsoft's warnings about HTML encoding the value if you are going to display it on a form, though.

how to download file using AngularJS and calling MVC API?

per various post... you cannot trigger a download via XHR. I needed to implement condition for the download, so, My solution was:

//make the call to the api with the ID to validate
someResource.get( { id: someId }, function(data) {
     //confirm that the ID is validated
     if (data.isIdConfirmed) {
         //get the token from the validation and issue another call
         //to trigger the download
         window.open('someapi/print/:someId?token='+ data.token);
     }
});

I wish that somehow, or someday the download can be triggered using XHR to avoid the second call. // _e

Get protocol, domain, and port from URL

Here is the solution I'm using:

const result = `${ window.location.protocol }//${ window.location.host }`;

EDIT:

To add cross-browser compatibility, use the following:

const result = `${ window.location.protocol }//${ window.location.hostname + (window.location.port ? ':' + window.location.port: '') }`;

Read line with Scanner

next() and nextLine() methods are associated with Scanner and is used for getting String inputs. Their differences are...

next() can read the input only till the space. It can't read two words separated by space. Also, next() places the cursor in the same line after reading the input.

nextLine() reads input including space between the words (that is, it reads till the end of line \n). Once the input is read, nextLine() positions the cursor in the next line.

Read article :Difference between next() and nextLine()

Replace your while loop with :

while(r.hasNext()) {
                scan = r.next();
                System.out.println(scan);
                if(scan.length()==0) {continue;}
                //treatment
            }

Using hasNext() and next() methods will resolve the issue.

Equivalent of waitForVisible/waitForElementPresent in Selenium WebDriver tests using Java?

For individual element the code below could be used:

private boolean isElementPresent(By by) {
        try {
            driver.findElement(by);
            return true;
        } catch (NoSuchElementException e) {
            return false;
        }
    }
for (int second = 0;; second++) {
            if (second >= 60){
                fail("timeout");
            }
            try {
                if (isElementPresent(By.id("someid"))){
                    break;
                }
                }
            catch (Exception e) {

            }
            Thread.sleep(1000);
        }

Generating sql insert into for Oracle

If you have to load a lot of data into tables on a regular basis, check out SQL Loader or external tables. Should be much faster than individual Inserts.

Error after upgrading pip: cannot import name 'main'

Is something wrong with the packages, when it generating de file /usr/bin/pip, you have to change the import:

from pip import main

to

from pip._internal import main

That solves the problem, I'm not sure why it generated, but it saids somthing in the following issue:

After pip 10 upgrade on pyenv "ImportError: cannot import name 'main'"

Detect if a NumPy array contains at least one non-numeric value?

With numpy 1.3 or svn you can do this

In [1]: a = arange(10000.).reshape(100,100)

In [3]: isnan(a.max())
Out[3]: False

In [4]: a[50,50] = nan

In [5]: isnan(a.max())
Out[5]: True

In [6]: timeit isnan(a.max())
10000 loops, best of 3: 66.3 µs per loop

The treatment of nans in comparisons was not consistent in earlier versions.

Can an Android NFC phone act as an NFC tag?

No, not at the moment. Google pointed out at the Google IO 2011, that card emulation is not supported and won't be supported for a while. Main (and easy to understand) problem: Which App should get the right on the phone to emulate a smartcard?

What's the best way to store a group of constants that my program uses?

Another vote for using web.config or app.config. The config files are a good place for constants like connection strings, etc. I prefer not to have to look at the source to view or modify these types of things. A static class which reads these constants from a .config file might be a good compromise, as it will let your application access these resources as though they were defined in code, but still give you the flexibility of having them in an easily viewable/editable space.

dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.62.dylib error running php after installing node with brew on Mac

Seems like it is impossible to link icu4c using brew after latest OS X update. Which makes things more interesting. The only solution I found working for me:

  1. Download and compile icu4c 62.1 to /usr/local/icu4c/62.1
mkdir ~/sources
cd ~/sources
wget http://download.icu-project.org/files/icu4c/62.1/icu4c-62_1-src.tgz
tar xvzf icu4c-62_1-src.tgz
cd icu/source/

sudo mkdir /usr/local/icu4c/62.1
./configure --prefix=/usr/local/icu4c/62.1
make
sudo make install
  1. Link libs:
ln -s /usr/local/icu4c/62.1/lib/*.dylib /usr/local/include/
  1. Set DYLD_LIBRARY_PATH in ~/.bash_profile:
export DYLD_LIBRARY_PATH=/usr/local/include

Removing unwanted table cell borders with CSS

After trying the above suggestions, the only thing that worked for me was changing the border attribute to "0" in the following sections of a child theme's style.css (do a "Find" operation to locate each one -- the following are just snippets):

.comment-content table {
    border-bottom: 1px solid #ddd;

.comment-content td {
    border-top: 1px solid #ddd;
    padding: 6px 10px 6px 0;
}

Thus looking like this afterwards:

.comment-content table {
    border-bottom: 0;

.comment-content td {
    border-top: 0;
    padding: 6px 10px 6px 0;
}

How to echo shell commands as they are executed

For zsh, echo

setopt VERBOSE

And for debugging,

setopt XTRACE

Fetch API with Cookie

This works for me:

import Cookies from 'universal-cookie';
const cookies = new Cookies();

function headers(set_cookie=false) {
  let headers = {
    'Accept':       'application/json',
    'Content-Type': 'application/json',
    'X-CSRF-Token': $('meta[name="csrf-token"]').attr('content')
};
if (set_cookie) {
    headers['Authorization'] = "Bearer " + cookies.get('remember_user_token');
}
return headers;
}

Then build your call:

export function fetchTests(user_id) {
  return function (dispatch) {
   let data = {
    method:      'POST',
    credentials: 'same-origin',
    mode:        'same-origin',
    body:        JSON.stringify({
                     user_id: user_id
                }),
    headers:     headers(true)
   };
   return fetch('/api/v1/tests/listing/', data)
      .then(response => response.json())
      .then(json => dispatch(receiveTests(json)));
    };
  }

Programmatically scroll a UIScrollView

Here is another use case which worked well for me.

  1. User tap a button/cell.
  2. Scroll to a position just enough to make a target view visible.

Code: Swift 5.3

// Assuming you have a view named "targeView"
scrollView.scroll(to: CGPoint(x:targeView.frame.minX, y:targeView.frame.minY), animated: true)

As you can guess if you want to scroll to make a bottom part of your target view visible then use maxX and minY.

Rails: How can I set default values in ActiveRecord?

class Item < ActiveRecord::Base
  def status
    self[:status] or ACTIVE
  end

  before_save{ self.status ||= ACTIVE }
end

How to pass variable as a parameter in Execute SQL Task SSIS?

A little late to the party, but this is how I did it for an insert:

DECLARE @ManagerID AS Varchar (25) = 'NA'
DECLARE @ManagerEmail AS Varchar (50) = 'NA'
Declare @RecordCount AS int = 0

SET @ManagerID = ?
SET @ManagerEmail = ?
SET @RecordCount = ?

INSERT INTO...

mongod command not recognized when trying to connect to a mongodb server

It is probably too late, but for the sake of others (like me) who faced the same problem. It is all about the little '\' at the end of the path variable. When you insert the path to MongoDB's bin directory at the end of the PATH windows variable, do not forget to put the '\' (Backslash) at the end, which tells windows it is a directory and not an executable named bin... e.g. I:\Program Files\MongoDB\Server\3.0\bin\

Using Pairs or 2-tuples in Java

I will start from a general point of view about tuples in Java and finish with an implication for your concrete problem.

1) The way tuples are used in non-generic languages is avoided in Java because they are not type-safe (e.g. in Python: tuple = (4, 7.9, 'python')). If you still want to use something like a general purpose tuple (which is not recommended), you should use Object[] or List<Object> and cast the elements after a check with instanceof to assure type-safety.

Usually, tuples in a certain setting are always used the same way with containing the same structure. In Java, you have to define this structure explicitly in a class to provide well-defined, type-safe values and methods. This seems annoying and unnecessairy at first but prevents errors already at compile-time.

2) If you need a tuple containing the same (super-)classes Foo, use Foo[], List<Foo>, or List<? extends Foo> (or the lists's immutable counterparts). Since a tuple is not of a defined length, this solution is equivalent.

3) In your case, you seem to need a Pair (i.e. a tuple of well-defined length 2). This renders maerics's answer or one of the supplementary answers the most efficient since you can reuse the code in the future.

Getting "Cannot call a class as a function" in my React Project

If you're on Node JS and you're seeing this error in a Class you've added to support a Cucumber test, it's because Cucumber will automatically try to run anything that exports a function, and NodeJS internally converts a Class to a function.

So instead of this:

module.exports = MyClass;

do this:

module.exports.MyClass = MyClass;

Then, when you import it into your steps file, do it like this:

let MyClass = require("myclass.js").MyClass;

This way you're not exporting a function. Read more here.

Warning: Null value is eliminated by an aggregate or other SET operation in Aqua Data Studio

You want to put the ISNULL inside of the COUNT function, not outside:

Not GOOD: ISNULL(COUNT(field), 0)

GOOD: COUNT(ISNULL(field, 0))

How to output an Excel *.xls file from classic ASP

You can always just export the HTML table to an XLS document. Excel does a pretty good job understanding HTML tables.

Another possiblitly is to export the HTML tables as a CSV or TSV file, but you would need to setup the formatting in your code. This isn't too difficult to accomplish.

There's some classes in the Microsoft.Office.Interop that allow you to create an Excel file programatically, but I have always found them to be a little clumsy. You can find a .NET version of creating a spreadsheet here, which should be pretty easy to modify for classic ASP.

As for .NET, I've always liked CarlosAG's Excel XML Writer Library. It has a nice generator so you can setup your Excel file, save it as an XML spreadsheet and it generates the code to do all the formatting and everything. I know it's not classic ASP, but I thought that I would throw it out there.


With what you're trying above, try adding the header:

"Content-Disposition", "attachment; filename=excelTest.xls"

See if that works. Also, I always use this for the content type:

  Response.ContentType = "application/octet-stream"
    Response.ContentType = "application/vnd.ms-excel"

Write to rails console

In addition to already suggested p and puts — well, actually in most cases you do can write logger.info "blah" just as you suggested yourself. It works in console too, not only in server mode.

But if all you want is console debugging, puts and p are much shorter to write, anyway.

How to convert NUM to INT in R?

Use as.integer:

set.seed(1)
x <- runif(5, 0, 100)
x
[1] 26.55087 37.21239 57.28534 90.82078 20.16819


as.integer(x)
[1] 26 37 57 90 20

Test for class:

xx <- as.integer(x)
str(xx)
 int [1:5] 26 37 57 90 20

Angular exception: Can't bind to 'ngForIn' since it isn't a known native property

In my case, WebStrom auto-complete inserted lowercased *ngfor, even when it looks like you choose the right camel cased one (*ngFor).

Saving numpy array to txt file row wise

I know this is old, but none of these answers solved the root problem of numpy not saving the array row-wise. I found that this one liner did the trick for me:

b = np.matrix(a)
np.savetxt("file", b)

Programmatically saving image to Django ImageField

class tweet_photos(models.Model):
upload_path='absolute path'
image=models.ImageField(upload_to=upload_path)
image_url = models.URLField(null=True, blank=True)
def save(self, *args, **kwargs):
    if self.image_url:
        import urllib, os
        from urlparse import urlparse
        file_save_dir = self.upload_path
        filename = urlparse(self.image_url).path.split('/')[-1]
        urllib.urlretrieve(self.image_url, os.path.join(file_save_dir, filename))
        self.image = os.path.join(file_save_dir, filename)
        self.image_url = ''
    super(tweet_photos, self).save()

How to give a Linux user sudo access?

Edit /etc/sudoers file either manually or using the visudo application. Remember: System reads /etc/sudoers file from top to the bottom, so you could overwrite a particular setting by putting the next one below. So to be on the safe side - define your access setting at the bottom.

Does Go have "if x in" construct similar to Python?

Another option is using a map as a set. You use just the keys and having the value be something like a boolean that's always true. Then you can easily check if the map contains the key or not. This is useful if you need the behavior of a set, where if you add a value multiple times it's only in the set once.

Here's a simple example where I add random numbers as keys to a map. If the same number is generated more than once it doesn't matter, it will only appear in the final map once. Then I use a simple if check to see if a key is in the map or not.

package main

import (
    "fmt"
    "math/rand"
)

func main() {
    var MAX int = 10

    m := make(map[int]bool)

    for i := 0; i <= MAX; i++ {
        m[rand.Intn(MAX)] = true
    }

    for i := 0; i <= MAX; i++ {
        if _, ok := m[i]; ok {
            fmt.Printf("%v is in map\n", i)
        } else {
            fmt.Printf("%v is not in map\n", i)
        }
    }
}

Here it is on the go playground

Easiest way to flip a boolean value?

I prefer John T's solution, but if you want to go all code-golfy, your statement logically reduces to this:

//if key is down, toggle the boolean, else leave it alone.
flipVal = ((wParam==VK_F11) && !flipVal) || (!(wParam==VK_F11) && flipVal);
if(wParam==VK_F11) Break;

//if key is down, toggle the boolean, else leave it alone.
otherVal = ((wParam==VK_F12) && !otherVal) || (!(wParam==VK_F12) && otherVal);
if(wParam==VK_F12) Break;

PHP/Apache: PHP Fatal error: Call to undefined function mysql_connect()

I had this same problem and had to refer to the php manual which told me the mysql and mysqli extensions require libmysql.dll to load. I searched for it under C:\windows\system32 (windows 7) and could not find, so I downloaded it here and placed it in my C:\windows\system32. I restarted Apache and everything worked fine. Took me 3 days to figure out, hope it helps.

How to yum install Node.JS on Amazon Linux

The accepted answer gave me node 0.10.36 and npm 1.3.6 which are very out of date. I grabbed the latest linux-x64 tarball from the nodejs downloads page and it wasn't too difficult to install: https://nodejs.org/dist/latest/.

# start in a directory where you like to install things for the current user
(For noobs : it downloads node package as node.tgz file in your directlry)
curl (paste the link to the one you want from the downloads page) >node.tgz

Now upzip the tar you just downloaded -

tar xzf node.tgz

Run this command and then also add it to your .bashrc:

export PATH="$PATH:(your install dir)/(node dir)/bin"

(example : export PATH ="$PATH:/home/ec2-user/mydirectory/node/node4.5.0-linux-x64/bin")

And update npm (only once, don't add to .bashrc):

npm install -g npm

Note that the -g there which means global, really means global to that npm instance which is the instance we just installed and is limited to the current user. This will apply to all packages that npm installs 'globally'.

How to validate an email address in JavaScript

Following regular expression:

/^([\w]+)(.[\w]+)*@([\w]+)(.[\w]{2,3}){1,2}$/;

Where does Internet Explorer store saved passwords?

I found the answer. IE stores passwords in two different locations based on the password type:

  • Http-Auth: %APPDATA%\Microsoft\Credentials, in encrypted files
  • Form-based: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\IntelliForms\Storage2, encrypted with the url

From a very good page on NirSoft.com:

Starting from version 7.0 of Internet Explorer, Microsoft completely changed the way that passwords are saved. In previous versions (4.0 - 6.0), all passwords were saved in a special location in the Registry known as the "Protected Storage". In version 7.0 of Internet Explorer, passwords are saved in different locations, depending on the type of password. Each type of passwords has some limitations in password recovery:

  • AutoComplete Passwords: These passwords are saved in the following location in the Registry: HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\IntelliForms\Storage2 The passwords are encrypted with the URL of the Web sites that asked for the passwords, and thus they can only be recovered if the URLs are stored in the history file. If you clear the history file, IE PassView won't be able to recover the passwords until you visit again the Web sites that asked for the passwords. Alternatively, you can add a list of URLs of Web sites that requires user name/password into the Web sites file (see below).

  • HTTP Authentication Passwords: These passwords are stored in the Credentials file under Documents and Settings\Application Data\Microsoft\Credentials, together with login passwords of LAN computers and other passwords. Due to security limitations, IE PassView can recover these passwords only if you have administrator rights.

In my particular case it answers the question of where; and I decided that I don't want to duplicate that. I'll continue to use CredRead/CredWrite, where the user can manage their passwords from within an established UI system in Windows.

Having both a Created and Last Updated timestamp columns in MySQL 4.0

You can have them both, just take off the "CURRENT_TIMESTAMP" flag on the created field. Whenever you create a new record in the table, just use "NOW()" for a value.

Or.

On the contrary, remove the 'ON UPDATE CURRENT_TIMESTAMP' flag and send the NOW() for that field. That way actually makes more sense.

How can I apply styles to multiple classes at once?

Don’t Repeat Your CSS

 a.abc, a.xyz{
    margin-left:20px;
 }

OR

 a{
    margin-left:20px;
 }

Docker Networking - nginx: [emerg] host not found in upstream

This can be solved with the mentioned depends_on directive since it's implemented now (2016):

version: '2'
  services:
    nginx:
      image: nginx
      ports:
        - "42080:80"
      volumes:
        - ./config/docker/nginx/default.conf:/etc/nginx/conf.d/default.conf:ro
      depends_on:
        - php

    php:
      build: config/docker/php
      ports:
        - "42022:22"
      volumes:
        - .:/var/www/html
      env_file: config/docker/php/.env.development
      depends_on:
        - mongo

    mongo:
      image: mongo
      ports:
        - "42017:27017"
      volumes:
        - /var/mongodata/wa-api:/data/db
      command: --smallfiles

Successfully tested with:

$ docker-compose version
docker-compose version 1.8.0, build f3628c7

Find more details in the documentation.

There is also a very interesting article dedicated to this topic: Controlling startup order in Compose

How to replace all dots in a string using JavaScript

Here's another implementation of replaceAll. Hope it helps someone.

    String.prototype.replaceAll = function (stringToFind, stringToReplace) {
        if (stringToFind === stringToReplace) return this;
        var temp = this;
        var index = temp.indexOf(stringToFind);
        while (index != -1) {
            temp = temp.replace(stringToFind, stringToReplace);
            index = temp.indexOf(stringToFind);
        }
        return temp;
    };

Then you can use it:

var myText = "My Name is George";
var newText = myText.replaceAll("George", "Michael");

Event for Handling the Focus of the EditText

  1. Declare object of EditText on top of class:

     EditText myEditText;
    
  2. Find EditText in onCreate Function and setOnFocusChangeListener of EditText:

    myEditText = findViewById(R.id.yourEditTextNameInxml); 
    
    myEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
                @Override
                public void onFocusChange(View view, boolean hasFocus) {
                    if (!hasFocus) {
                         Toast.makeText(this, "Focus Lose", Toast.LENGTH_SHORT).show();
                    }else{
                        Toast.makeText(this, "Get Focus", Toast.LENGTH_SHORT).show();
                    }
    
                }
            });
    

It works fine.

Access POST values in Symfony2 request object

I think that in order to get the request data, bound and validated by the form object, you must use :

$form->getClientData();

How to get all values from python enum class?

You can use IntEnum:

from enum import IntEnum

class Color(IntEnum):
   RED = 1
   BLUE = 2


print(int(Color.RED))   # prints 1

To get list of the ints:

enum_list = list(map(int, Color))
print(enum_list) # prints [1, 2]

How to stop creating .DS_Store on Mac?

Open Terminal. Execute this command:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

Either restart the computer or log out and back in to the user account.

for more informations:

http://support.apple.com/kb/ht1629

Use .htaccess to redirect HTTP to HTTPs

Problem solved!

Final .htaccess:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /

RewriteCond %{ENV:HTTPS} !=on
RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [R,L]

# BEGIN WordPress
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Maven: How to include jars, which are not available in reps into a J2EE project?

None of the solutions work if you are using Jenkins build!! When pom is run inside Jenkins build server.. these solutions will fail, as Jenkins run pom will try to download these files from enterprise repository.

Copy jars under src/main/resources/lib (create lib folder). These will be part of your project and go all the way to deployment server. In deployment server, make sure your startup scripts contain src/main/resources/lib/* in classpath. Viola.

Convert JS date time to MySQL datetime

The venerable DateJS library has a formatting routine (it overrides ".toString()"). You could also do one yourself pretty easily because the "Date" methods give you all the numbers you need.

How to check if current thread is not main thread

Summarizing the solutions, I think that's the best one:

boolean isUiThread = VERSION.SDK_INT >= VERSION_CODES.M 
    ? Looper.getMainLooper().isCurrentThread()
    : Thread.currentThread() == Looper.getMainLooper().getThread();

And, if you wish to run something on the UI thread, you can use this:

new Handler(Looper.getMainLooper()).post(new Runnable() {
    @Override
    public void run() {
       //this runs on the UI thread
    }
});

Tkinter: "Python may not be configured for Tk"

Had the same issue on Fedora with Python 2.7. Turns out some extra packages are required:

sudo dnf install tk-devel tkinter

After installing the packages, this hello-world example seems to be working fine on Python 2.7:

$ cat hello.py
from Tkinter import *
root = Tk()
w = Label(root, text="Hello, world!")
w.pack()
root.mainloop()
$ python --version
Python 2.7.8
$ python hello.py

And through X11 forwarding, it looks like this:

Hello World through X11

Note that in Python 3, the module name is lowercase, and other packages are probably required...

from tkinter import *

How do I combine the first character of a cell with another cell in Excel?

Personally I like the & function for this

Assuming that you are using cells A1 and A2 for John Smith

=left(a1,1) & b1

If you want to add text between, for example a period

=left(a1,1) & "." & b1

How to show "Done" button on iPhone number pad

The simplest way is:

Create custom transparent button and place it in left down corner, which will have same CGSize as empty space in UIKeyboardTypeNumberPad. Toggle (show / hide) this button on textField becomeFirstResponder, on button click respectively.

Tomcat: java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens

It happened to me when I had a same port used in ssh tunnel SOCKS to run Proxy in 8080 port and my server and my firefox browser proxy was set to that port and got this issue.

MySQL SELECT only not null values

SELECT * FROM TABLE_NAME
where COLUMN_NAME <> '';

NGINX: upstream timed out (110: Connection timed out) while reading response header from upstream

You should always refrain from increasing the timeouts, I doubt your backend server response time is the issue here in any case.

I got around this issue by clearing the connection keep-alive flag and specifying http version as per the answer here: https://stackoverflow.com/a/36589120/479632

server {
    location / {
        proxy_set_header   X-Real-IP $remote_addr;
        proxy_set_header   Host      $http_host;

        # these two lines here
        proxy_http_version 1.1;
        proxy_set_header Connection "";

        proxy_pass http://localhost:5000;
    }
}

Unfortunately I can't explain why this works and didn't manage to decipher it from the docs mentioned in the answer linked either so if anyone has an explanation I'd be very interested to hear it.

Adding a new array element to a JSON object

var Str_txt = '{"theTeam":[{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"3","status":"member"}]}';

If you want to add at last position then use this:

var parse_obj = JSON.parse(Str_txt);
parse_obj['theTeam'].push({"teamId":"4","status":"pending"});
Str_txt = JSON.stringify(parse_obj);
Output //"{"theTeam":[{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"3","status":"member"},{"teamId":"4","status":"pending"}]}"

If you want to add at first position then use the following code:

var parse_obj = JSON.parse(Str_txt);
parse_obj['theTeam'].unshift({"teamId":"4","status":"pending"});
Str_txt = JSON.stringify(parse_obj);
Output //"{"theTeam":[{"teamId":"4","status":"pending"},{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"3","status":"member"}]}"

Anyone who wants to add at a certain position of an array try this:

parse_obj['theTeam'].splice(2, 0, {"teamId":"4","status":"pending"});
Output //"{"theTeam":[{"teamId":"1","status":"pending"},{"teamId":"2","status":"member"},{"teamId":"4","status":"pending"},{"teamId":"3","status":"member"}]}"

Above code block adds an element after the second element.

Logical operators ("and", "or") in DOS batch

Try the negation operand - 'not'!

Well, if you can perform 'AND' operation on an if statement using nested 'if's (refer previous answers), then you can do the same thing with 'if not' to perform an 'or' operation.

If you haven't got the idea quite as yet, read on. Otherwise, just don't waste your time and get back to programming.

Just as nested 'if's are satisfied only when all conditions are true, nested 'if not's are satisfied only when all conditions are false. This is similar to what you want to do with an 'or' operand, isn't it?

Even when any one of the conditions in the nested 'if not' is true, the whole statement remains non-satisfied. Hence, you can use negated 'if's in succession by remembering that the body of the condition statement should be what you wanna do if all your nested conditions are false. The body that you actually wanted to give should come under the else statement.

And if you still didn't get the jist of the thing, sorry, I'm 16 and that's the best I can do to explain.

How do I POST JSON data with cURL?

Use -d option to add payload

curl -X POST \
http://<host>:<port>/<path> \
-H 'Accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"foo": "bar",
"lorem": "ipsum"
}'

In addition:

use -X POST to use POST method

use -H 'Accept: application/json' to add accept type header

use -H 'Content-Type: application/json' to add content type header