Programs & Examples On #Hotlinking

Hotlinking is the use of a linked object, often an image, from one site by a web page belonging to a second site.

How to prevent a file from direct URL Access?

First of all, find where the main apache’s config file httpd.conf is located. If you use Debian, it should be here: /etc/apache/httpd.conf. Using some file editor like Vim or Nano open this file and find the line that looks as follows:

Options Includes Indexes FollowSymLinks MultiViews

then remove word Indexes and save the file. The line should look like this one:

Options Includes FollowSymLinks MultiViews

After it is done, restart apache (e.g. /etc/init.d/apache restart in Debian). That’s it!

Why do I get a "permission denied" error while installing a gem?

After setting the gems directory to the user directory that runs the gem install, using export GEM_HOME=/home/<user>/gems, the issue has been solved.

What processes are using which ports on unix?

netstat -pln

EDIT: linux only, on other UNIXes netstat may not support all these options.

Sun JSTL taglib declaration fails with "Can not find the tag library descriptor"

I was getting the same problem onenter image description here Spring Tool Suite 3.2 and changed the version of jstl to 1.2 (from 1.1.2) manually when adding it to the dependency list, and the error got disappeared.

How to Resize a Bitmap in Android?

import android.graphics.Matrix
public Bitmap getResizedBitmap(Bitmap bm, int newWidth, int newHeight) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);

    // "RECREATE" THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(
        bm, 0, 0, width, height, matrix, false);
    bm.recycle();
    return resizedBitmap;
}

EDIT: as suggested by by @aveschini, I have added bm.recycle(); for memory leaks. Please note that in case if you are using the previous object for some other purposes, then handle accordingly.

How to include vars file in a vars file with ansible?

I know it's an old post but I had the same issue today, what I did is simple : changing my script that send my playbook from my local host to the server, before sending it with maven command, I did this :

cat common_vars.yml > vars.yml
cat snapshot_vars.yml >> vars.yml
# or 
#cat release_vars.yml >> vars.yml
mvn ....

How can I get the line number which threw exception?

Update to the answer

    // Get stack trace for the exception with source file information
    var st = new StackTrace(ex, true);
    // Get the top stack frame
    var frame = st.GetFrame(st.FrameCount-1);
    // Get the line number from the stack frame
    var line = frame.GetFileLineNumber();

Where to get this Java.exe file for a SQL Developer installation

I encountered the following message repeatedly when trying to start SQL Developer from my installation of Oracle Database 11g Enterprise: Enter the full pathname for java.exe.

No matter how many times I browsed to the correct path, I kept being presented with the exact same dialog box. This was in Windows 7, and the solution was to right-click on the SQL Developer icon and select "Run as administrator". I then used this path: C:\app\shellperson\product\11.1.0\db_1\jdk\jre\bin\java.exe

How do I get the title of the current active window using c#?

Loop over Application.Current.Windows[] and find the one with IsActive == true.

How to link HTML5 form action to Controller ActionResult method in ASP.NET MVC 4

Here I'm basically wrapping a button in a link. The advantage is that you can post to different action methods in the same form.

<a href="Controller/ActionMethod">
    <input type="button" value="Click Me" />
</a>

Adding parameters:

<a href="Controller/ActionMethod?userName=ted">
    <input type="button" value="Click Me" />
</a>

Adding parameters from a non-enumerated Model:

<a href="Controller/[email protected]">
    <input type="button" value="Click Me" />
</a>

You can do the same for an enumerated Model too. You would just have to reference a single entity first. Happy Coding!

How to change a table name using an SQL query?

execute this command

sp_rename 'Employee','EData'

Error sending json in POST to web API service

Please check if you are were passing method as POST instead as GET. if so you will get same error as a you posted above.

$http({               
 method: 'GET',

The request entity's media type 'text/plain' is not supported for this resource.

findViewByID returns null

I have the same problem, but I think its worth sharing with you guys. If you have to findViewById in custom layout, for example:

public class MiniPlayerControllBar extends LinearLayout {
    //code
}

you cannot get the view in constructor. You should call findViewById after view has inflated. Their is a method you can override onFinishInflate

Passing Multiple route params in Angular2

As detailed in this answer, mayur & user3869623's answer's are now relating to a deprecated router. You can now pass multiple parameters as follows:

To call router:

this.router.navigate(['/myUrlPath', "someId", "another ID"]);

In routes.ts:

{ path: 'myUrlpath/:id1/:id2', component: componentToGoTo},

Move cursor to end of file in vim

Try doing SHIFT + G and you will be at the end of the page, but you can't edit yet. Go to the top by doing G + G

Cannot find module '../build/Release/bson'] code: 'MODULE_NOT_FOUND' } js-bson: Failed to load c++ bson extension, using pure JS version

Unfortunately, All the above answers are only half right.. Took a long time to figure this out..

Mongoose bson install via npm throws warning and causes the error...

npm install -g node-gyp

git clone https://github.com/mongodb/js-bson.git
cd js-bson
npm install
node-gyp rebuild

This works like magic!!

Getting a timestamp for today at midnight?

_x000D_
_x000D_
function getTodaysTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const startOfDay = currentTimeStamp - (currentTimeStamp % 86400);_x000D_
  return { startOfDay, endOfDay: startOfDay + 86400 - 1 };_x000D_
}_x000D_
_x000D_
// starts from sunday_x000D_
function getThisWeeksTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const currentDay = new Date(currentTimeStamp * 1000);_x000D_
  const startOfWeek = currentTimeStamp - (currentDay.getDay() * 86400) - (currentTimeStamp % 86400);_x000D_
  return { startOfWeek, endOfWeek: startOfWeek + 7 * 86400 - 1 };_x000D_
}_x000D_
_x000D_
_x000D_
function getThisMonthsTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const currentDay = new Date(currentTimeStamp * 1000);_x000D_
  const startOfMonth = currentTimeStamp - ((currentDay.getDate() - 1) * 86400) - (currentTimeStamp % 86400);_x000D_
  const currentMonth = currentDay.getMonth() + 1;_x000D_
  let daysInMonth = 0;_x000D_
  if (currentMonth === 2) daysInMonth = 28;_x000D_
  else if ([1, 3, 5, 7, 8, 10, 12].includes(currentMonth)) daysInMonth = 31;_x000D_
  else daysInMonth = 30;_x000D_
  return { startOfMonth, endOfMonth: startOfMonth + daysInMonth * 86400 - 1 };_x000D_
}_x000D_
_x000D_
_x000D_
console.log(getTodaysTimeStamp());_x000D_
console.log(getThisWeeksTimeStamp());_x000D_
console.log(getThisMonthsTimeStamp());
_x000D_
_x000D_
_x000D_

How to open a second activity on click of button in android app

Button btn = (Button) findViewById(R.id.button1);

btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent myIntent = new Intent(MainActivity.this, MainActivity2.class);
        MainActivity.this.startActivity(myIntent);       
    }  
});

The answer for the complete noob from a complete noob: MainActivity is the name of the first activity. MainActivity2 is the name of the second activity. button1 is the I.D of the button in xml for MainActivity Activity.

How to enable PHP short tags?

if you edit your php.ini file, remember to restart your service (apache2, etc) for the edits to php.ini to take effect

Connection string using Windows Authentication

For the correct solution after many hours:

  1. Open the configuration file
  2. Change the connection string with the following

<add name="umbracoDbDSN" connectionString="data source=YOUR_SERVER_NAME;database=nrc;Integrated Security=SSPI;persist security info=True;" providerName="System.Data.SqlClient" />

  1. Change the YOUR_SERVER_NAME with your current server name and save
  2. Open the IIS Manager
  3. Find the name of the application pool that the website or web application is using
  4. Right-click and choose Advanced settings
  5. From Advanced settings under Process Model change the Identity to Custom account and add your Server Admin details, please see the attached images:

enter image description here

Hope this will help.

Is it possible that one domain name has multiple corresponding IP addresses?

You can do it. That is what big guys do as well.

First query:

» host google.com 
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229

Next query:

» host google.com
google.com has address 74.125.232.224
google.com has address 74.125.232.225
google.com has address 74.125.232.226
google.com has address 74.125.232.227
google.com has address 74.125.232.228
google.com has address 74.125.232.229
google.com has address 74.125.232.230
google.com has address 74.125.232.231
google.com has address 74.125.232.232
google.com has address 74.125.232.233
google.com has address 74.125.232.238

As you see, the list of IPs rotated around, but the relative order between two IPs stayed the same.

Update: I see several comments bragging about how DNS round-robin is not convenient for fail-over, so here is the summary: DNS is not for fail-over. So it is obviously not good for fail-over. It was never designed to be a solution for fail-over.

How to solve ADB device unauthorized in Android ADB host device?

For me, the emulator could not have Google Play Services enabled. It could have Google APIs or be x86 or x64 but not google play store.

How to set order of repositories in Maven settings.xml

As far as I know, the order of the repositories in your pom.xml will also decide the order of the repository access.

As for configuring repositories in settings.xml, I've read that the order of repositories is interestingly enough the inverse order of how the repositories will be accessed.

Here a post where someone explains this curiosity:
http://community.jboss.org/message/576851

Oracle "(+)" Operator

In Oracle, (+) denotes the "optional" table in the JOIN. So in your query,

SELECT a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id=b.id(+)

it's a LEFT OUTER JOIN of table 'b' to table 'a'. It will return all data of table 'a' without losing its data when the other side (optional table 'b') has no data.

Diagram of Left Outer Join

The modern standard syntax for the same query would be

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
LEFT JOIN b ON a.id=b.id

or with a shorthand for a.id=b.id (not supported by all databases):

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
LEFT JOIN b USING(id)

If you remove (+) then it will be normal inner join query

Older syntax, in both Oracle and other databases:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id=b.id

More modern syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
INNER JOIN b ON a.id=b.id

Or simply:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
JOIN b ON a.id=b.id

Diagram of Inner Join

It will only return all data where both 'a' & 'b' tables 'id' value is same, means common part.

If you want to make your query a Right Join

This is just the same as a LEFT JOIN, but switches which table is optional.

Diagram of Right Outer Join

Old Oracle syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a,b
WHERE a.id(+)=b.id

Modern standard syntax:

SELECT  a.id, b.id, a.col_2, b.col_2, ...
FROM a
RIGHT JOIN b ON a.id=b.id

Ref & help:

https://asktom.oracle.com/pls/asktom/f?p=100:11:::::P11_QUESTION_ID:6585774577187

Left Outer Join using + sign in Oracle 11g

https://www.w3schools.com/sql/sql_join_left.asp

Is it possible to use Java 8 for Android development?

Android OFFICIALLY supports Java 8 as of Android N.

Feature announcements are here, the Java 8 language announcement is:

Improved Java 8 language support - We’re excited to bring Java 8 language features to Android. With Android's Jack compiler, you can now use many popular Java 8 language features, including lambdas and more, on Android versions as far back as Gingerbread. The new features help reduce boilerplate code. For example, lambdas can replace anonymous inner classes when providing event listeners. Some Java 8 language features --like default and static methods, streams, and functional interfaces -- are also now available on N and above. With Jack, we’re looking forward to tracking the Java language more closely while maintaining backward compatibility.

Can I style an image's ALT text with CSS?

You cant style the alt attribute directly in css. However the alt will inherit the styles of the item the alt is on or what is inherited by its parent:

_x000D_
_x000D_
    <div style="background-color:black; height: 50px; width: 50px; color:white;">_x000D_
    <img src="ouch" alt="here i am"/>_x000D_
    <div>
_x000D_
_x000D_
_x000D_

In the above example, the alt text will be black. However with the color:white the alt text is white.

Why is Spring's ApplicationContext.getBean considered bad?

You should to use: ConfigurableApplicationContext instead of for ApplicationContext

Use Font Awesome Icon in Placeholder

Teocci solution is as simple as it can be, thus, no need to add any CSS, just add class="fas" for Font Awesome 5, since it adds proper CSS font declaration to the element.

Here's an example for search box within Bootstrap navbar, with search icon added to the both input-group and placeholder (for the sake of demontration, of course, no one would use both at the same time). Image: https://i.imgur.com/v4kQJ77.png "> Code:

<form class="form-inline my-2 my-lg-0">
    <div class="input-group mb-3">
        <div class="input-group-prepend">
            <span class="input-group-text"><i class="fas fa-search"></i></span>
        </div>
        <input type="text" class="form-control fas text-right" placeholder="&#xf002;" aria-label="Search string">
        <div class="input-group-append">
            <button class="btn btn-success input-group-text bg-success text-white border-0">Search</button>
        </div>
    </div>
</form>

Getting the closest string match

You might find this library helpful! http://code.google.com/p/google-diff-match-patch/

It is currently available in Java, JavaScript, Dart, C++, C#, Objective C, Lua and Python

It works pretty well too. I use it in a couple of my Lua projects.

And I don't think it would be too difficult to port it to other languages!

How to remove all CSS classes using jQuery/JavaScript?

Since not all versions of jQuery are created equal, you may run into the same issue I did which means calling $("#item").removeClass(); does not actually remove the class. (Probably a bug)

A more reliable method is to simply use raw JavaScript and remove the class attribute altogether.

document.getElementById("item").removeAttribute("class");

How to set the width of a RaisedButton in Flutter?

If you don't want to remove all the button theme set up.




ButtonTheme.fromButtonThemeData(
  data: Theme.of(context).buttonTheme.copyWith(
                minWidth: 200.0,
                height: 100.0,,
              )
  child: RaisedButton(
    onPressed: () {},
    child: Text("test"),
  ),
);

How to check for file existence

Check out Pathname and in particular Pathname#exist?.

File and its FileTest module are perhaps simpler/more direct, but I find Pathname a nicer interface in general.

How to run SQL in shell script

Code

PL_CONNECT_STRING="$DB_USERNAME/$DB_PASSWORD@$DB_SERVICE"

OUTPUT=$(sqlplus -s $PL_CONNECT_STRING <<-END-OF-SQL
           select count(*) from table;
exit;
END-OF-SQL)
echo "COMPLETED GATHER STATS $OUTPUT";

Explanation:

PL_CONNECT_STRING carry database username, password and it service name

sqlplus is used to connect the Database with PL_CONNECT_STRING details

END-OF-SQL tag contain the query which you want to execute

echo is used to print the output of the query

NOTE: You can give multiple Query inside the END-OF-SQL tag, so its useful for batch execution as well

React Native: Possible unhandled promise rejection

catch function in your api should either return some data which could be handled by Api call in React class or throw new error which should be caught using a catch function in your React class code. Latter approach should be something like:

return fetch(url)
.then(function(response){
  return response.json();
})
.then(function(json){
  return {
    city: json.name,
    temperature: kelvinToF(json.main.temp),
    description: _.capitalize(json.weather[0].description)
  }
})
.catch(function(error) {
console.log('There has been a problem with your fetch operation: ' + error.message);
 // ADD THIS THROW error
  throw error;
});

Then in your React Class:

Api(region.latitude, region.longitude)
  .then((data) => {
    console.log(data);
    this.setState(data);
  }).catch((error)=>{
     console.log("Api call error");
     alert(error.message);
  });

How do I fix this "TypeError: 'str' object is not callable" error?

You are trying to use the string as a function:

"Your new price is: $"(float(price) * 0.1)

Because there is nothing between the string literal and the (..) parenthesis, Python interprets that as an instruction to treat the string as a callable and invoke it with one argument:

>>> "Hello World!"(42)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object is not callable

Seems you forgot to concatenate (and call str()):

easygui.msgbox("Your new price is: $" + str(float(price) * 0.1))

The next line needs fixing as well:

easygui.msgbox("Your new price is: $" + str(float(price) * 0.2))

Alternatively, use string formatting with str.format():

easygui.msgbox("Your new price is: ${:.2f}".format(float(price) * 0.1))
easygui.msgbox("Your new price is: ${:.2f}".format(float(price) * 0.2))

where {:02.2f} will be replaced by your price calculation, formatting the floating point value as a value with 2 decimals.

Get the cartesian product of a series of lists?

I would use list comprehension :

somelists = [
   [1, 2, 3],
   ['a', 'b'],
   [4, 5]
]

cart_prod = [(a,b,c) for a in somelists[0] for b in somelists[1] for c in somelists[2]]

SQL Server dynamic PIVOT query?

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

Table creation and data insertion:

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

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

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

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

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

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

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

--Execute the Dynamic Pivot Query
EXEC sp_executesql @DynamicPivotQuery

OUTPUT :

enter image description here

How to send emails from my Android application?

I use the below code in my apps. This shows exactly email client apps, such as Gmail.

    Intent contactIntent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts("mailto", getString(R.string.email_to), null));
    contactIntent.putExtra(Intent.EXTRA_SUBJECT, getString(R.string.email_subject));
    startActivity(Intent.createChooser(contactIntent, getString(R.string.email_chooser)));

Pyspark: display a spark data frame in a table format

The show method does what you're looking for.

For example, given the following dataframe of 3 rows, I can print just the first two rows like this:

df = sqlContext.createDataFrame([("foo", 1), ("bar", 2), ("baz", 3)], ('k', 'v'))
df.show(n=2)

which yields:

+---+---+
|  k|  v|
+---+---+
|foo|  1|
|bar|  2|
+---+---+
only showing top 2 rows

Finding the indices of matching elements in list in Python

if you're doing a lot of this kind of thing you should consider using numpy.

In [56]: import random, numpy

In [57]: lst = numpy.array([random.uniform(0, 5) for _ in range(1000)]) # example list

In [58]: a, b = 1, 3

In [59]: numpy.flatnonzero((lst > a) & (lst < b))[:10]
Out[59]: array([ 0, 12, 13, 15, 18, 19, 23, 24, 26, 29])

In response to Seanny123's question, I used this timing code:

import numpy, timeit, random

a, b = 1, 3

lst = numpy.array([random.uniform(0, 5) for _ in range(1000)])

def numpy_way():
    numpy.flatnonzero((lst > 1) & (lst < 3))[:10]

def list_comprehension():
    [e for e in lst if 1 < e < 3][:10]

print timeit.timeit(numpy_way)
print timeit.timeit(list_comprehension)

The numpy version is over 60 times faster.

Calculate a Running Total in SQL Server

Here are 2 simple ways to calculate running total:

Approach 1: It can be written this way if your DBMS supports Analytical Functions

SELECT     id
           ,somedate
           ,somevalue
           ,runningtotal = SUM(somevalue) OVER (ORDER BY somedate ASC)
FROM       TestTable

Approach 2: You can make use of OUTER APPLY if your database version / DBMS itself does not support Analytical Functions

SELECT     T.id
           ,T.somedate
           ,T.somevalue
           ,runningtotal = OA.runningtotal
FROM       TestTable T
           OUTER APPLY (
                           SELECT   runningtotal = SUM(TI.somevalue)
                           FROM     TestTable TI
                           WHERE    TI.somedate <= S.somedate
                       ) OA;

Note:- If you have to calculate the running total for different partitions separately, it can be done as posted here: Calculating Running totals across rows and grouping by ID

How to get function parameter names/values dynamically?

I know this is an old question, but beginners have been copypasting this around as if this was good practice in any code. Most of the time, having to parse a function's string representation to use its parameter names just hides a flaw in the code's logic.

Parameters of a function are actually stored in an array-like object called arguments, where the first argument is arguments[0], the second is arguments[1] and so on. Writing parameter names in the parentheses can be seen as a shorthand syntax. This:

function doSomething(foo, bar) {
    console.log("does something");
}

...is the same as:

function doSomething() {
    var foo = arguments[0];
    var bar = arguments[1];

    console.log("does something");
}

The variables themselves are stored in the function's scope, not as properties in an object. There is no way to retrieve the parameter name through code as it is merely a symbol representing the variable in human-language.

I always considered the string representation of a function as a tool for debugging purposes, especially because of this arguments array-like object. You are not required to give names to the arguments in the first place. If you try parsing a stringified function, it doesn't actually tell you about extra unnamed parameters it might take.

Here's an even worse and more common situation. If a function has more than 3 or 4 arguments, it might be logical to pass it an object instead, which is easier to work with.

function saySomething(obj) {
  if(obj.message) console.log((obj.sender || "Anon") + ": " + obj.message);
}

saySomething({sender: "user123", message: "Hello world"});

In this case, the function itself will be able to read through the object it receives and look for its properties and get both their names and values, but trying to parse the string representation of the function would only give you "obj" for parameters, which isn't useful at all.

Linq : select value in a datatable column

I notice others have given the non-lambda syntax so just to have this complete I'll put in the lambda syntax equivalent:

Non-lambda (as per James's post):

var name = from i in DataContext.MyTable
           where i.ID == 0
           select i.Name

Equivalent lambda syntax:

var name = DataContext.MyTable.Where(i => i.ID == 0)
                              .Select(i => new { Name = i.Name });

There's not really much practical difference, just personal opinion on which you prefer.

Height of status bar in Android

the height of the status bar is 24dp in android 6.0

 <!-- Height of the status bar -->
 <dimen name="status_bar_height">24dp</dimen>
 <!-- Height of the bottom navigation / system bar. -->
 <dimen name="navigation_bar_height">48dp</dimen>

you can find the answer in the source code: frameworks\base\core\res\res\values\dimens.xml

What causes a Python segmentation fault?

This happens when a python extension (written in C) tries to access a memory beyond reach.

You can trace it in following ways.

  • Add sys.settrace at the very first line of the code.
  • Use gdb as described by Mark in this answer.. At the command prompt

    gdb python
    (gdb) run /path/to/script.py
    ## wait for segfault ##
    (gdb) backtrace
    ## stack trace of the c code
    

Regular Expression Validation For Indian Phone Number and Mobile number

You can use regular expression like this.

/^[(]+\ ++\d{2}[)]+[^0]+\d{9}/

Should switch statements always contain a default clause?

If you know that the switch statement will only ever have a strict defined set of labels or values, just do this to cover the bases, that way you will always get valid outcome.. Just put the default over the label that would programmatically/logically be the best handler for other values.

switch(ResponseValue)
{
    default:
    case No:
        return false;
    case Yes;
        return true;
}

What does "fatal: bad revision" mean?

If you want to delete any commit then you might need to use git rebase command

git rebase -i HEAD~2

it will show you last 2 commit messages, if you delete the commit message and save that file deleted commit will automatically disappear...

How to install ADB driver for any android device?

You don't really need to install or use any third party tools.

The drivers located in ...\Android\Sdk\extras\google\usb_driver work just fine.

Step 1: In Device Manager, Right click on the malfunctioning Android ADB Interface driver

Step 2: Select Update Driver Software

Step 3: Select Browse my computer for driver software

Step 4: Select Let me pick from a list of device drivers on my computer

Step 5: Select Have Disk

This window pops up:

enter image description here

Step 6: Copy the location of the Google USB Driver (...\Android\Sdk\extras\google\usb_driver) or browse to it.

Step 7: Click Ok

This window pops up:

enter image description here

Step 8: Select Android ADB Interface and click Next

The window below pops up with a warning:

enter image description here

That's it. You driver installation will start and in a few seconds, you should be able to see your device

Difference between Encapsulation and Abstraction

Briefly, Abstraction happens at class level by hiding implementation and implementing an interface to be able to interact with the instance of the class. Whereas, Encapsulation is used to hide information; for instance, making the member variables private to ban the direct access and providing getters and setters for them for indicrect access.

How to convert Integer to int?

Another simple way would be:

Integer i = new Integer("10");

if (i != null)
    int ip = Integer.parseInt(i.toString());

Recording video feed from an IP camera over a network

about 3 years ago i needed cctv. I found zoneminder, tried to edit it to my liking, but found i was fixing it more than editing it.

Not to mention mp4 recording feature isn't actually part of the master branch (which is kind of lol, since its a cctv program and its already been about 3 years or more since it was suggested). Its literally just adapting the ffmpeg command lol.

So i found the solution!

If you want something done right, do it yourself.

I present to you Shinobi! Shinobi : The Open Source CCTV Platform

enter image description here

sys.argv[1], IndexError: list index out of range

sys.argv represents the command line options you execute a script with.

sys.argv[0] is the name of the script you are running. All additional options are contained in sys.argv[1:].

You are attempting to open a file that uses sys.argv[1] (the first argument) as what looks to be the directory.

Try running something like this:

python ConcatenateFiles.py /tmp

Adding image to JFrame

As martijn-courteaux said, create a custom component it's the better option. In C# exists a component called PictureBox and I tried to create this component for Java, here is the code:

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JComponent;

public class JPictureBox extends JComponent {

    private Icon icon = null;
    private final Dimension dimension = new Dimension(100, 100);
    private Image image = null;
    private ImageIcon ii = null;
    private SizeMode sizeMode = SizeMode.STRETCH;
    private int newHeight, newWidth, originalHeight, originalWidth;

    public JPictureBox() {
        JPictureBox.this.setPreferredSize(dimension);
        JPictureBox.this.setOpaque(false);
        JPictureBox.this.setSizeMode(SizeMode.STRETCH);
    }

    @Override
    public void paintComponent(Graphics g) {
        if (ii != null) {
            switch (getSizeMode()) {
                case NORMAL:
                    g.drawImage(image, 0, 0, ii.getIconWidth(), ii.getIconHeight(), null);
                    break;
                case ZOOM:
                    aspectRatio();
                    g.drawImage(image, 0, 0, newWidth, newHeight, null);
                    break;
                case STRETCH:
                    g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), null);
                    break;
                case CENTER:
                    g.drawImage(image, (int) (this.getWidth() / 2) - (int) (ii.getIconWidth() / 2), (int) (this.getHeight() / 2) - (int) (ii.getIconHeight() / 2), ii.getIconWidth(), ii.getIconHeight(), null);
                    break;
                default:
                    g.drawImage(image, 0, 0, this.getWidth(), this.getHeight(), null);
            }
        }
    }

    public Icon getIcon() {
        return icon;
    }

    public void setIcon(Icon icon) {
        this.icon = icon;
        ii = (ImageIcon) icon;
        image = ii.getImage();
        originalHeight = ii.getIconHeight();
        originalWidth = ii.getIconWidth();
    }

    public SizeMode getSizeMode() {
        return sizeMode;
    }

    public void setSizeMode(SizeMode sizeMode) {
        this.sizeMode = sizeMode;
    }

    public enum SizeMode {
        NORMAL,
        STRETCH,
        CENTER,
        ZOOM
    }

    private void aspectRatio() {
        if (ii != null) {
            newHeight = this.getHeight();
            newWidth = (originalWidth * newHeight) / originalHeight;
        }
    }

}

If you want to add an image, choose the JPictureBox, after that go to Properties and find "icon" property and select an image. If you want to change the sizeMode property then choose the JPictureBox, after that go to Properties and find "sizeMode" property, you can choose some values:

  • NORMAL value, the image is positioned in the upper-left corner of the JPictureBox.
  • STRETCH value causes the image to stretch or shrink to fit the JPictureBox.
  • ZOOM value causes the image to be stretched or shrunk to fit the JPictureBox; however, the aspect ratio in the original is maintained.
  • CENTER value causes the image to be centered in the client area.

If you want to learn more about this topic, you can check this video.

Also you can see the code on Gitlab or Github.

How to set an button align-right with Bootstrap?

This work for me in bootstrap 4:

    <div class="alert alert-info">
      <a href="#" class="alert-link">Summary:Its some description.......testtesttest</a>  
      <button type="button" class="btn btn-primary btn-lg float-right">Large button</button>
    </div>

How to nicely format floating numbers to string without unnecessary decimal 0's

Format price with grouping, rounding, and no unnecessary zeroes (in double).

Rules:

  1. No zeroes at the end (2.0000 = 2; 1.0100000 = 1.01)
  2. Two digits maximum after a point (2.010 = 2.01; 0.20 = 0.2)
  3. Rounding after the 2nd digit after a point (1.994 = 1.99; 1.995 = 2; 1.006 = 1.01; 0.0006 -> 0)
  4. Returns 0 (null/-0 = 0)
  5. Adds $ (= $56/-$56)
  6. Grouping (101101.02 = $101,101.02)

More examples:

-99.985 = -$99.99

10 = $10

10.00 = $10

20.01000089 = $20.01

It is written in Kotlin as a fun extension of Double (because it is used in Android), but it can be converted to Java easily, because Java classes were used.

/**
 * 23.0 -> $23
 *
 * 23.1 -> $23.1
 *
 * 23.01 -> $23.01
 *
 * 23.99 -> $23.99
 *
 * 23.999 -> $24
 *
 * -0.0 -> $0
 *
 * -5.00 -> -$5
 *
 * -5.019 -> -$5.02
 */
fun Double?.formatUserAsSum(): String {
    return when {
        this == null || this == 0.0 -> "$0"
        this % 1 == 0.0 -> DecimalFormat("$#,##0;-$#,##0").format(this)
        else -> DecimalFormat("$#,##0.##;-$#,##0.##").format(this)
    }
}

How to use:

var yourDouble: Double? = -20.00
println(yourDouble.formatUserAsSum()) // will print -$20

yourDouble = null
println(yourDouble.formatUserAsSum()) // will print $0

About DecimalFormat: https://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html

How do you remove a specific revision in the git history?

So here is the scenario that I faced, and how I solved it.

[branch-a]

[Hundreds of commits] -> [R] -> [I]

here R is the commit that I needed to be removed, and I is a single commit that comes after R

I made a revert commit and squashed them together

git revert [commit id of R]
git rebase -i HEAD~3

During the interactive rebase squash the last 2 commits.

How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

Just throwing in a simple two-line C# implementation using recursion, because all the answers here seem far more complicated than necessary.

/// <summary>
/// Gets the column letter(s) corresponding to the given column number.
/// </summary>
/// <param name="column">The one-based column index. Must be greater than zero.</param>
/// <returns>The desired column letter, or an empty string if the column number was invalid.</returns>
public static string GetColumnLetter(int column) {
    if (column < 1) return String.Empty;
    return GetColumnLetter((column - 1) / 26) + (char)('A' + (column - 1) % 26);
}

New og:image size for Facebook share?

EDIT: The current best practices regarding Open Graph image sizes are officially outlined here: https://developers.facebook.com/docs/sharing/best-practices#images


There was a post in the Facebook developers group today, where one of the FB guys uploaded a PDF containing their new rules about image sizes – since that seems to be available only if you’re a member of the group, I uploaded it here: http://www.sendspace.com/file/ghqwhr

And they also said they will post about it in the developer blog in the coming days, so keep checking there as well

To summarize the linked document:

  • Minimum size in pixels is 600x315
  • Recommended size is 1200x630 - Images this size will get a larger display treatment.
  • Aspect ratio should be 1.91:1

What is the proper declaration of main in C++?

The main function must be declared as a non-member function in the global namespace. This means that it cannot be a static or non-static member function of a class, nor can it be placed in a namespace (even the unnamed namespace).

The name main is not reserved in C++ except as a function in the global namespace. You are free to declare other entities named main, including among other things, classes, variables, enumerations, member functions, and non-member functions not in the global namespace.

You can declare a function named main as a member function or in a namespace, but such a function would not be the main function that designates where the program starts.

The main function cannot be declared as static or inline. It also cannot be overloaded; there can be only one function named main in the global namespace.

The main function cannot be used in your program: you are not allowed to call the main function from anywhere in your code, nor are you allowed to take its address.

The return type of main must be int. No other return type is allowed (this rule is in bold because it is very common to see incorrect programs that declare main with a return type of void; this is probably the most frequently violated rule concerning the main function).

There are two declarations of main that must be allowed:

int main()               // (1)
int main(int, char*[])   // (2)

In (1), there are no parameters.

In (2), there are two parameters and they are conventionally named argc and argv, respectively. argv is a pointer to an array of C strings representing the arguments to the program. argc is the number of arguments in the argv array.

Usually, argv[0] contains the name of the program, but this is not always the case. argv[argc] is guaranteed to be a null pointer.

Note that since an array type argument (like char*[]) is really just a pointer type argument in disguise, the following two are both valid ways to write (2) and they both mean exactly the same thing:

int main(int argc, char* argv[])
int main(int argc, char** argv)

Some implementations may allow other types and numbers of parameters; you'd have to check the documentation of your implementation to see what it supports.

main() is expected to return zero to indicate success and non-zero to indicate failure. You are not required to explicitly write a return statement in main(): if you let main() return without an explicit return statement, it's the same as if you had written return 0;. The following two main() functions have the same behavior:

int main() { }
int main() { return 0; }

There are two macros, EXIT_SUCCESS and EXIT_FAILURE, defined in <cstdlib> that can also be returned from main() to indicate success and failure, respectively.

The value returned by main() is passed to the exit() function, which terminates the program.

Note that all of this applies only when compiling for a hosted environment (informally, an environment where you have a full standard library and there's an OS running your program). It is also possible to compile a C++ program for a freestanding environment (for example, some types of embedded systems), in which case startup and termination are wholly implementation-defined and a main() function may not even be required. If you're writing C++ for a modern desktop OS, though, you're compiling for a hosted environment.

Fixed positioned div within a relative parent div

Gavin,

The issue you are having is a misunderstanding of positioning. If you want it to be "fixed" relative to the parent, then you really want your #fixed to be position:absolute which will update its position relative to the parent.

This question fully describes positioning types and how to use them effectively.

In summary, your CSS should be

#wrap{ 
    position:relative;
}
#fixed{ 
    position:absolute;
    top:30px;
    left:40px;
}

LINQ Group By and select collection

you can achive it with group join

var result = (from c in Customers
          join oi in OrderItems on c.Id equals oi.Order.Customer.Id into g
          Select new { customer = c, orderItems = g});

c is Customer and g is the customers order items.

How add spaces between Slick carousel item

Since the latest versions you can simply add a margin to your slides:

.slick-slide {
  margin: 0 20px;
}

There's no need for any kind of negative margins, since slick's calculation is based on the elements outerHeight.

Add line break within tooltips

You can use bootstrap tooltip, and don't forget to set the html option to true.

<div id="tool"> tooltip</div>
$('#tool').tooltip({
     title: 'line one' +'<br />'+ 'line two',
     html: true
});
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>

Posting raw image data as multipart/form-data in curl

In case anyone had the same problem: check this as @PravinS suggested. I used the exact same code as shown there and it worked for me perfectly.

This is the relevant part of the server code that helped:

if (isset($_POST['btnUpload']))
{
$url = "URL_PATH of upload.php"; // e.g. http://localhost/myuploader/upload.php // request URL
$filename = $_FILES['file']['name'];
$filedata = $_FILES['file']['tmp_name'];
$filesize = $_FILES['file']['size'];
if ($filedata != '')
{
    $headers = array("Content-Type:multipart/form-data"); // cURL headers for file uploading
    $postfields = array("filedata" => "@$filedata", "filename" => $filename);
    $ch = curl_init();
    $options = array(
        CURLOPT_URL => $url,
        CURLOPT_HEADER => true,
        CURLOPT_POST => 1,
        CURLOPT_HTTPHEADER => $headers,
        CURLOPT_POSTFIELDS => $postfields,
        CURLOPT_INFILESIZE => $filesize,
        CURLOPT_RETURNTRANSFER => true
    ); // cURL options
    curl_setopt_array($ch, $options);
    curl_exec($ch);
    if(!curl_errno($ch))
    {
        $info = curl_getinfo($ch);
        if ($info['http_code'] == 200)
            $errmsg = "File uploaded successfully";
    }
    else
    {
        $errmsg = curl_error($ch);
    }
    curl_close($ch);
}
else
{
    $errmsg = "Please select the file";
}
}

html form should look something like:

<form action="uploadpost.php" method="post" name="frmUpload" enctype="multipart/form-data">
<tr>
  <td>Upload</td>
  <td align="center">:</td>
  <td><input name="file" type="file" id="file"/></td>
</tr>
<tr>
  <td>&nbsp;</td>
  <td align="center">&nbsp;</td>
  <td><input name="btnUpload" type="submit" value="Upload" /></td>
</tr>

What is a simple command line program or script to backup SQL server databases?

I'm using tsql on a Linux/UNIX infrastructure to access MSSQL databases. Here's a simple shell script to dump a table to a file:

#!/usr/bin/ksh
#
#.....
(
tsql -S {database} -U {user} -P {password} <<EOF
select * from {table}
go
quit
EOF
) >{output_file.dump}

How do you rename a MongoDB database?

No there isn't. See https://jira.mongodb.org/browse/SERVER-701

Unfortunately, this is not an simple feature for us to implement due to the way that database metadata is stored in the original (default) storage engine. In MMAPv1 files, the namespace (e.g.: dbName.collection) that describes every single collection and index includes the database name, so to rename a set of database files, every single namespace string would have to be rewritten. This impacts:

  • the .ns file
  • every single numbered file for the collection
  • the namespace for every index
  • internal unique names of each collection and index
  • contents of system.namespaces and system.indexes (or their equivalents in the future)
  • other locations I may be missing

This is just to accomplish a rename of a single database in a standalone mongod instance. For replica sets the above would need to be done on every replica node, plus on each node every single oplog entry that refers this database would have to be somehow invalidated or rewritten, and then if it's a sharded cluster, one also needs to add these changes to every shard if the DB is sharded, plus the config servers have all the shard metadata in terms of namespaces with their full names.

There would be absolutely no way to do this on a live system.

To do it offline, it would require re-writing every single database file to accommodate the new name, and at that point it would be as slow as the current "copydb" command...

Node.js global proxy setting

replace {userid} and {password} with your id and password in your organization or login to your machine.

npm config set proxy http://{userid}:{password}@proxyip:8080/
npm config set https-proxy http://{userid}:{password}@proxyip:8080/
npm config set http-proxy http://{userid}:{password}@proxyip:8080/
strict-ssl=false

Redraw datatables after using ajax to refresh the table content?

This works for me

var dataTable = $('#HelpdeskOverview').dataTable();

var oSettings = dataTable.fnSettings();
dataTable.fnClearTable(this);
for (var i=0; i<json.aaData.length; i++)
{
   dataTable.oApi._fnAddData(oSettings, json.aaData[i]);
}
oSettings.aiDisplay = oSettings.aiDisplayMaster.slice();
dataTable.fnDraw();

How to determine tables size in Oracle

If you don't have DBA rights then you can use user_segments table:

select bytes/1024/1024 MB from user_segments where segment_name='Table_name'

hasNext in Python iterators?

Suggested way is StopIteration. Please see Fibonacci example from tutorialspoint

#!usr/bin/python3

import sys
def fibonacci(n): #generator function
   a, b, counter = 0, 1, 0
   while True:
      if (counter > n): 
         return
      yield a
      a, b = b, a + b
      counter += 1
f = fibonacci(5) #f is iterator object

while True:
   try:
      print (next(f), end=" ")
   except StopIteration:
      sys.exit()

WHERE vs HAVING

WHERE filters before data is grouped, and HAVING filters after data is grouped. This is an important distinction; rows that are eliminated by a WHERE clause will not be included in the group. This could change the calculated values which, in turn(=as a result) could affect which groups are filtered based on the use of those values in the HAVING clause.

And continues,

HAVING is so similar to WHERE that most DBMSs treat them as the same thing if no GROUP BY is specified. Nevertheless, you should make that distinction yourself. Use HAVING only in conjunction with GROUP BY clauses. Use WHERE for standard row-level filtering.

Excerpt From: Forta, Ben. “Sams Teach Yourself SQL in 10 Minutes (5th Edition) (Sams Teach Yourself...).”.

How can INSERT INTO a table 300 times within a loop in SQL?

You may try it like this:

DECLARE @i int = 0
WHILE @i < 300 
BEGIN
    SET @i = @i + 1
    /* your code*/
END

Show compose SMS view in Android

You can omit tel number for letting user just choose from contacts, but inserting your sms text in the body. Code is for Xamarin Android:

    var uri = Uri.Parse("smsto:"); //append your number here for explicit nb
    var intent = new Intent(Intent.ActionSendto, uri);
    intent.PutExtra("sms_body", text);
    Context.StartActivity(intent);

where

Context is Xamarin.Essentials.Platform.CurrentActivity ?? Application.Context

Unable to Resolve Module in React Native App

I was able to solve this issue by adding a file extension '.js'. I was using Intellij and created a js file, but it did not have the file extension. When I did a refractor rename and changed my component from 'List' to 'List.js' react native then knew how to resolve it.

LINQ to SQL - How to select specific columns and return strongly typed list

Basically you are doing it the right way. However, you should use an instance of the DataContext for querying (it's not obvious that DataContext is an instance or the type name from your query):

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new Person { Name = a.Name, Age = a.Age }).ToList();

Apparently, the Person class is your LINQ to SQL generated entity class. You should create your own class if you only want some of the columns:

class PersonInformation {
   public string Name {get;set;}
   public int Age {get;set;}
}

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new PersonInformation { Name = a.Name, Age = a.Age }).ToList();

You can freely swap var with List<PersonInformation> here without affecting anything (as this is what the compiler does).

Otherwise, if you are working locally with the query, I suggest considering an anonymous type:

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new { a.Name, a.Age }).ToList();

Note that in all of these cases, the result is statically typed (it's type is known at compile time). The latter type is a List of a compiler generated anonymous class similar to the PersonInformation class I wrote above. As of C# 3.0, there's no dynamic typing in the language.

UPDATE:

If you really want to return a List<Person> (which might or might not be the best thing to do), you can do this:

var result = from a in new DataContext().Persons
             where a.Age > 18
             select new { a.Name, a.Age };

List<Person> list = result.AsEnumerable()
                          .Select(o => new Person {
                                           Name = o.Name, 
                                           Age = o.Age
                          }).ToList();

You can merge the above statements too, but I separated them for clarity.

How to count frequency of characters in a string?

import java.util.*;
class Charfrequency
{
 public static void main(String a[]){

        Scanner sc=new Scanner(System.in);
        System.out.println("Enter Your String :");
        String s1=sc.nextLine();
        int count,j=1;
        char var='a';
        char ch[]=s1.toCharArray();
        while(j<=26)
        {
           count=0;
                for(int i=0; i<s1.length(); i++)
                {
                    if(ch[i]==var || ch[i]==var-32)
                    {
                        count++;
                    }
                }
                if(count>0){
                System.out.println("Frequency of "+var+" is "+count);
                }
                var++;
                j++;
        }
 }
}

How do I format XML in Notepad++?

If you get this error:

Notepad++ Error: Cannot load 32-bit plugin

Cannot load 32-bit plugin, XMLTools.dll is not compatible with the current version of Notepad++

Here you can find a working version for Windows 10 x64: Xml Tools 2.4.9.2 Unicode

Note: It's the only version I've found working on Windows 10 Professional x64.

How to see log files in MySQL?

In addition to the answers above you can pass in command line parameters to the mysqld process for logging options instead of manually editing your conf file. For example, to enable general logging and specifiy a file:

mysqld --general-log --general-log-file=/var/log/mysql.general.log

Confirming other answers above, mysqld --help --verbose gives you the values from the conf file (so running with command line options general-log is FALSE); whereas mysql -se "SHOW VARIABLES" | grep -e log_error -e general_log gives:

general_log     ON
general_log_file        /var/log/mysql.general.log

Use slightly more compact syntax for the error log:

mysqld --general-log --general-log-file=/var/log/mysql.general.log --log-error=/var/log/mysql.error.log

Should each and every table have a primary key?

I always have a primary key, even if in the beginning I don't have a purpose in mind yet for it. There have been a few times when I eventually need a PK in a table that doesn't have one and it's always more trouble to put it in later. I think there is more of an upside to always including one.

Adjusting and image Size to fit a div (bootstrap)

I had this same problem and stumbled upon the following simple solution. Just add a bit of padding to the image and it resizes itself to fit within the div.

<div class="col-sm-3">
  <img src="xxx.png" class="img-responsive" style="padding-top: 5px">
</div>

Pass a simple string from controller to a view MVC3

If you are trying to simply return a string to a View, try this:

public string Test()
{
     return "test";
}

This will return a view with the word test in it. You can insert some html in the string.

You can also try this:

public ActionResult Index()
{
    return Content("<html><b>test</b></html>");
}

How to submit an HTML form without redirection

You need Ajax to make it happen. Something like this:

$(document).ready(function(){
    $("#myform").on('submit', function(){
        var name = $("#name").val();
        var email = $("#email").val();
        var password = $("#password").val();
        var contact = $("#contact").val();

        var dataString = 'name1=' + name + '&email1=' + email + '&password1=' + password + '&contact1=' + contact;
        if(name=='' || email=='' || password=='' || contact=='')
        {
            alert("Please fill in all fields");
        }
        else
        {
            // Ajax code to submit form.
            $.ajax({
                type: "POST",
                url: "ajaxsubmit.php",
                data: dataString,
                cache: false,
                success: function(result){
                    alert(result);
                }
           });
        }
        return false;
    });
});

Numpy: find index of the elements within range

This code snippet returns all the numbers in a numpy array between two values:

a = np.array([1, 3, 5, 6, 9, 10, 14, 15, 56] )
a[(a>6)*(a<10)]

It works as following: (a>6) returns a numpy array with True (1) and False (0), so does (a<10). By multiplying these two together you get an array with either a True, if both statements are True (because 1x1 = 1) or False (because 0x0 = 0 and 1x0 = 0).

The part a[...] returns all values of array a where the array between brackets returns a True statement.

Of course you can make this more complicated by saying for instance

...*(1-a<10) 

which is similar to an "and Not" statement.

Why does a base64 encoded string have an = sign at the end

It's padding. From http://en.wikipedia.org/wiki/Base64:

In theory, the padding character is not needed for decoding, since the number of missing bytes can be calculated from the number of Base64 digits. In some implementations, the padding character is mandatory, while for others it is not used. One case in which padding characters are required is concatenating multiple Base64 encoded files.

How to get resources directory path programmatically

Finally, this is what I did:

private File getFileFromURL() {
    URL url = this.getClass().getClassLoader().getResource("/sql");
    File file = null;
    try {
        file = new File(url.toURI());
    } catch (URISyntaxException e) {
        file = new File(url.getPath());
    } finally {
        return file;
    }
}

...

File folder = getFileFromURL();
File[] listOfFiles = folder.listFiles();

Do fragments really need an empty constructor?

Yes they do.

You shouldn't really be overriding the constructor anyway. You should have a newInstance() static method defined and pass any parameters via arguments (bundle)

For example:

public static final MyFragment newInstance(int title, String message) {
    MyFragment f = new MyFragment();
    Bundle bdl = new Bundle(2);
    bdl.putInt(EXTRA_TITLE, title);
    bdl.putString(EXTRA_MESSAGE, message);
    f.setArguments(bdl);
    return f;
}

And of course grabbing the args this way:

@Override
public void onCreate(Bundle savedInstanceState) {
    title = getArguments().getInt(EXTRA_TITLE);
    message = getArguments().getString(EXTRA_MESSAGE);

    //...
    //etc
    //...
}

Then you would instantiate from your fragment manager like so:

@Override
public void onCreate(Bundle savedInstanceState) {
    if (savedInstanceState == null){
        getSupportFragmentManager()
            .beginTransaction()
            .replace(R.id.content, MyFragment.newInstance(
                R.string.alert_title,
                "Oh no, an error occurred!")
            )
            .commit();
    }
}

This way if detached and re-attached the object state can be stored through the arguments. Much like bundles attached to Intents.

Reason - Extra reading

I thought I would explain why for people wondering why.

If you check: https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/app/Fragment.java

You will see the instantiate(..) method in the Fragment class calls the newInstance method:

public static Fragment instantiate(Context context, String fname, @Nullable Bundle args) {
    try {
        Class<?> clazz = sClassMap.get(fname);
        if (clazz == null) {
            // Class not found in the cache, see if it's real, and try to add it
            clazz = context.getClassLoader().loadClass(fname);
            if (!Fragment.class.isAssignableFrom(clazz)) {
                throw new InstantiationException("Trying to instantiate a class " + fname
                        + " that is not a Fragment", new ClassCastException());
            }
            sClassMap.put(fname, clazz);
        }
        Fragment f = (Fragment) clazz.getConstructor().newInstance();
        if (args != null) {
            args.setClassLoader(f.getClass().getClassLoader());
            f.setArguments(args);
        }
        return f;
    } catch (ClassNotFoundException e) {
        throw new InstantiationException("Unable to instantiate fragment " + fname
                + ": make sure class name exists, is public, and has an"
                + " empty constructor that is public", e);
    } catch (java.lang.InstantiationException e) {
        throw new InstantiationException("Unable to instantiate fragment " + fname
                + ": make sure class name exists, is public, and has an"
                + " empty constructor that is public", e);
    } catch (IllegalAccessException e) {
        throw new InstantiationException("Unable to instantiate fragment " + fname
                + ": make sure class name exists, is public, and has an"
                + " empty constructor that is public", e);
    } catch (NoSuchMethodException e) {
        throw new InstantiationException("Unable to instantiate fragment " + fname
                + ": could not find Fragment constructor", e);
    } catch (InvocationTargetException e) {
        throw new InstantiationException("Unable to instantiate fragment " + fname
                + ": calling Fragment constructor caused an exception", e);
    }
}

http://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#newInstance() Explains why, upon instantiation it checks that the accessor is public and that that class loader allows access to it.

It's a pretty nasty method all in all, but it allows the FragmentManger to kill and recreate Fragments with states. (The Android subsystem does similar things with Activities).

Example Class

I get asked a lot about calling newInstance. Do not confuse this with the class method. This whole class example should show the usage.

/**
 * Created by chris on 21/11/2013
 */
public class StationInfoAccessibilityFragment extends BaseFragment implements JourneyProviderListener {

    public static final StationInfoAccessibilityFragment newInstance(String crsCode) {
        StationInfoAccessibilityFragment fragment = new StationInfoAccessibilityFragment();

        final Bundle args = new Bundle(1);
        args.putString(EXTRA_CRS_CODE, crsCode);
        fragment.setArguments(args);

        return fragment;
    }

    // Views
    LinearLayout mLinearLayout;

    /**
     * Layout Inflater
     */
    private LayoutInflater mInflater;
    /**
     * Station Crs Code
     */
    private String mCrsCode;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mCrsCode = getArguments().getString(EXTRA_CRS_CODE);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        mInflater = inflater;
        return inflater.inflate(R.layout.fragment_station_accessibility, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        mLinearLayout = (LinearLayout)view.findViewBy(R.id.station_info_accessibility_linear);
        //Do stuff
    }

    @Override
    public void onResume() {
        super.onResume();
        getActivity().getSupportActionBar().setTitle(R.string.station_info_access_mobility_title);
    }

    // Other methods etc...
}

How to generate javadoc comments in Android Studio

In Android Studio you don't need the plug in. On A Mac just open Android Studio -> click Android Studio in the top bar -> click Prefrences -> find File and Code Templates in the list -> select includes -> build it and will be persistent in all your project

Python: Passing variables between functions

return returns a value. It doesn't matter what name you gave to that value. Returning it just "passes it out" so that something else can use it. If you want to use it, you have to grab it from outside:

lst = defineAList()
useTheList(lst)

Returning list from inside defineAList doesn't mean "make it so the whole rest of the program can use that variable". It means "pass this variable out and give the rest of the program one chance to grab it and use it". You need to assign that value to something outside the function in order to make use of it. Also, because of this, there is no need to define your list ahead of time with list = []. Inside defineAList, you create a new list and return it; this list has no relationship to the one you defined with list = [] at the beginning.

Incidentally, I changed your variable name from list to lst. It's not a good idea to use list as a variable name because that is already the name of a built-in Python type. If you make your own variable called list, you won't be able to access the builtin one anymore.

Pushing an existing Git repository to SVN

If you don't have to use any specific SVN and you are using GitHub you can use their SVN connector.

More information is here: Collaborating on GitHub with Subversion

Is it possible to Turn page programmatically in UIPageViewController?

Here's another code example for a single paged view. Implementation for viewControllerAtIndex is omitted here, it should return the correct view controller for the given index.

- (void)changePage:(UIPageViewControllerNavigationDirection)direction {
    NSUInteger pageIndex = ((FooViewController *) [_pageViewController.viewControllers objectAtIndex:0]).pageIndex;

    if (direction == UIPageViewControllerNavigationDirectionForward) {
        pageIndex++;
    }
    else {
        pageIndex--;
    }

    FooViewController *viewController = [self viewControllerAtIndex:pageIndex];

    if (viewController == nil) {
        return;
    }

    [_pageViewController setViewControllers:@[viewController]
                                  direction:direction
                                   animated:YES
                                 completion:nil];
}

Pages can be changed by calling

[self changePage:UIPageViewControllerNavigationDirectionReverse];
[self changePage:UIPageViewControllerNavigationDirectionForward];

How do I update a GitHub forked repository?

If you want to keep your GitHub forks up to date with the respective upstreams, there also exists this probot program for GitHub specifically: https://probot.github.io/apps/pull/ which does the job. You would need to allow installation in your account and it will keep your forks up to date.

Navigation bar with UIImage for title

    let imageView = UIImageView(frame: (CGRect(x: 0, y: 0, width: 40, height: 
    40)))
    imageView.contentMode = .scaleAspectFit
    let image = UIImage (named: "logo") // logo is your NPG asset 
    imageView.image = image
    self.navigationItem.titleView = imageView

Reshaping data.frame from wide to long format

Since this answer is tagged with , I felt it would be useful to share another alternative from base R: stack.

Note, however, that stack does not work with factors--it only works if is.vector is TRUE, and from the documentation for is.vector, we find that:

is.vector returns TRUE if x is a vector of the specified mode having no attributes other than names. It returns FALSE otherwise.

I'm using the sample data from @Jaap's answer, where the values in the year columns are factors.

Here's the stack approach:

cbind(wide[1:2], stack(lapply(wide[-c(1, 2)], as.character)))
##    Code     Country values  ind
## 1   AFG Afghanistan 20,249 1950
## 2   ALB     Albania  8,097 1950
## 3   AFG Afghanistan 21,352 1951
## 4   ALB     Albania  8,986 1951
## 5   AFG Afghanistan 22,532 1952
## 6   ALB     Albania 10,058 1952
## 7   AFG Afghanistan 23,557 1953
## 8   ALB     Albania 11,123 1953
## 9   AFG Afghanistan 24,555 1954
## 10  ALB     Albania 12,246 1954

Ajax - 500 Internal Server Error

I had the same error. It turns out that the cause was that the back end method was expecting different json data. In my Ajax call i had something like this:

$.ajax({
        async: false,
        type: "POST",
        url: "http://13.82.13.196/api.aspx/PostAjax",
        data: '{"url":"test"}',
        contentType: "application/json; charset=utf-8",
        dataType: "json",
    });

Now in my WebMethod, inside my C# backend code i had declared my endpoint like this:

public static string PostAjax(AjaxSettings settings)

Where AjaxSettings was declared:

public class AjaxSettings
{
    public string url { get; set; }
}

The problem then was that the mapping between my ajax call and my back-end endpoint was not the same. As soon as i changed my ajax call to the following, it all worked well!

var data ='{"url":"test"}';    
$.ajax({
    async: false,
    type: "POST",
    url: "http://13.82.13.196/api.aspx/PostAjax",
    data: '{"settings":'+data+'}',
    contentType: "application/json; charset=utf-8",
    dataType: "json"
});

I had to change the data variable inside the Ajax call in order to match the method signature exactly.

Excel Validation Drop Down list using VBA

Private Sub main()

'replace "J2" with the cell you want to insert the drop down list
With Range("J2").Validation
    .Delete
    'replace "=A1:A6" with the range the data is in.
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
    Operator:=xlBetween, Formula1:="=Sheet1!A1:A6"
    .IgnoreBlank = True
    .InCellDropdown = True
    .InputTitle = ""
    .ErrorTitle = ""
    .InputMessage = ""
    .ErrorMessage = ""
    .ShowInput = True
    .ShowError = True
End With
End Sub

How to interpolate variables in strings in JavaScript, without concatenation?

String.prototype.interpole = function () {
    var c=0, txt=this;
    while (txt.search(/{var}/g) > 0){
        txt = txt.replace(/{var}/, arguments[c]);
        c++;
    }
    return txt;
}

Uso:

var hello = "foo";
var my_string = "I pity the {var}".interpole(hello);
//resultado "I pity the foo"

How to multiply duration by integer?

It's nice that Go has a Duration type -- having explicitly defined units can prevent real-world problems.

And because of Go's strict type rules, you can't multiply a Duration by an integer -- you must use a cast in order to multiply common types.

/*
MultiplyDuration Hide semantically invalid duration math behind a function
*/
func MultiplyDuration(factor int64, d time.Duration) time.Duration {
    return time.Duration(factor) * d        // method 1 -- multiply in 'Duration'
 // return time.Duration(factor * int64(d)) // method 2 -- multiply in 'int64'
}

The official documentation demonstrates using method #1:

To convert an integer number of units to a Duration, multiply:

seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s

But, of course, multiplying a duration by a duration should not produce a duration -- that's nonsensical on the face of it. Case in point, 5 milliseconds times 5 milliseconds produces 6h56m40s. Attempting to square 5 seconds results in an overflow (and won't even compile if done with constants).

By the way, the int64 representation of Duration in nanoseconds "limits the largest representable duration to approximately 290 years", and this indicates that Duration, like int64, is treated as a signed value: (1<<(64-1))/(1e9*60*60*24*365.25) ~= 292, and that's exactly how it is implemented:

// A Duration represents the elapsed time between two instants
// as an int64 nanosecond count. The representation limits the
// largest representable duration to approximately 290 years.
type Duration int64

So, because we know that the underlying representation of Duration is an int64, performing the cast between int64 and Duration is a sensible NO-OP -- required only to satisfy language rules about mixing types, and it has no effect on the subsequent multiplication operation.

If you don't like the the casting for reasons of purity, bury it in a function call as I have shown above.

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

You can always use Sharepoint Solution Generator to create a project and edit in VS2008.

You can find the Generator along with Sharepoint Developer tools.

Removing carriage return and new-line from the end of a string in c#

This should work ...

var tst = "12345\n\n\r\n\r\r";
var res = tst.TrimEnd( '\r', '\n' );

Determine if two rectangles overlap each other?

Ask yourself the opposite question: How can I determine if two rectangles do not intersect at all? Obviously, a rectangle A completely to the left of rectangle B does not intersect. Also if A is completely to the right. And similarly if A is completely above B or completely below B. In any other case A and B intersect.

What follows may have bugs, but I am pretty confident about the algorithm:

struct Rectangle { int x; int y; int width; int height; };

bool is_left_of(Rectangle const & a, Rectangle const & b) {
   if (a.x + a.width <= b.x) return true;
   return false;
}
bool is_right_of(Rectangle const & a, Rectangle const & b) {
   return is_left_of(b, a);
}

bool not_intersect( Rectangle const & a, Rectangle const & b) {
   if (is_left_of(a, b)) return true;
   if (is_right_of(a, b)) return true;
   // Do the same for top/bottom...
 }

bool intersect(Rectangle const & a, Rectangle const & b) {
  return !not_intersect(a, b);
}

Detect click outside Angular component

Above mentioned answers are correct but what if you are doing a heavy process after losing the focus from the relevant component. For that, I came with a solution with two flags where the focus out event process will only take place when losing the focus from relevant component only.

isFocusInsideComponent = false;
isComponentClicked = false;

@HostListener('click')
clickInside() {
    this.isFocusInsideComponent = true;
    this.isComponentClicked = true;
}

@HostListener('document:click')
clickout() {
    if (!this.isFocusInsideComponent && this.isComponentClicked) {
        // do the heavy process

        this.isComponentClicked = false;
    }
    this.isFocusInsideComponent = false;
}

Hope this will help you. Correct me If have missed anything.

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key country

You are facing this problem because when you are posting your forms so after reloading your dropdown is unable to find data in viewbag. So make sure that code you are using in get method while retrieving your data from db or from static list, copy paste that code into post verb as well..

Happy Coding :)

Forward X11 failed: Network error: Connection refused

you should install a x server such as XMing. and keep the x server is running. config your putty like this :Connection-Data-SSH-X11-Enable X11 forwarding should be checked. and X display location : localhost:0

Regex: Use start of line/end of line signs (^ or $) in different context

you just need to use word boundary (\b) instead of ^ and $:

\bgarp\b

how to upload file using curl with php

Use:

if (function_exists('curl_file_create')) { // php 5.5+
  $cFile = curl_file_create($file_name_with_full_path);
} else { // 
  $cFile = '@' . realpath($file_name_with_full_path);
}
$post = array('extra_info' => '123456','file_contents'=> $cFile);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$target_url);
curl_setopt($ch, CURLOPT_POST,1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
$result=curl_exec ($ch);
curl_close ($ch);

You can also refer:

http://blog.derakkilgo.com/2009/06/07/send-a-file-via-post-with-curl-and-php/

Important hint for PHP 5.5+:

Now we should use https://wiki.php.net/rfc/curl-file-upload but if you still want to use this deprecated approach then you need to set curl_setopt($ch, CURLOPT_SAFE_UPLOAD, false);

How to clear exisiting dropdownlist items when its content changes?

Please use the following

ddlCity.Items.Clear();

How to change the button color when it is active using bootstrap?

HTML--

<div class="col-sm-12" id="my_styles">
   <button type="submit" class="btn btn-warning" id="1">Button1</button>
   <button type="submit" class="btn btn-warning" id="2">Button2</button>
</div>

css--

.active{
         background:red;
    }
 button.btn:active{
     background:red;
 }

jQuery--

jQuery("#my_styles .btn").click(function(){
    jQuery("#my_styles .btn").removeClass('active');
    jQuery(this).toggleClass('active'); 

});

view the live demo on jsfiddle

How to create an empty matrix in R?

If you don't know the number of columns ahead of time, add each column to a list and cbind at the end.

List <- list()
for(i in 1:n)
{
    normF <- #something
    List[[i]] <- normF
}
Matrix = do.call(cbind, List)

How to make a transparent border using CSS?

You can also use border-style: double with background-clip: padding-box, without the use of any extra (pseudo-)elements. It's probably the most compact solution, but not as flexible as the others.

For example:

<div class="circle">Some text goes here...</div>

.circle{
    width: 100px;
    height: 100px;
    padding: 50px;
    border-radius: 200px;
    border: double 15px rgba(255,255,255,0.7);
    background: rgba(255,255,255,0.7);
    background-clip: padding-box;
}

Result

If you look closely you can see that the edge between the border and the background is not perfect. This seems to be an issue in current browsers. But it's not that noticeable when the border is small.

Why use def main()?

Without the main sentinel, the code would be executed even if the script were imported as a module.

How to convert CLOB to VARCHAR2 inside oracle pl/sql

Converting VARCHAR2 to CLOB

In PL/SQL a CLOB can be converted to a VARCHAR2 with a simple assignment, SUBSTR, and other methods. A simple assignment will only work if the CLOB is less then or equal to the size of the VARCHAR2. The limit is 32767 in PL/SQL and 4000 in SQL (although 12c allows 32767 in SQL).

For example, this code converts a small CLOB through a simple assignment and then coverts the beginning of a larger CLOB.

declare
    v_small_clob clob := lpad('0', 1000, '0');
    v_large_clob clob := lpad('0', 32767, '0') || lpad('0', 32767, '0');
    v_varchar2   varchar2(32767);
begin
    v_varchar2 := v_small_clob;
    v_varchar2 := substr(v_large_clob, 1, 32767);
end;

LONG?

The above code does not convert the value to a LONG. It merely looks that way because of limitations with PL/SQL debuggers and strings over 999 characters long.

For example, in PL/SQL Developer, open a Test window and add and debug the above code. Right-click on v_varchar2 and select "Add variable to Watches". Step through the code and the value will be set to "(Long Value)". There is a ... next to the text but it does not display the contents. PLSQL Developer Long Value

C#?

I suspect the real problem here is with C# but I don't know how enough about C# to debug the problem.

Getting unique items from a list

Use a HashSet<T>. For example:

var items = "A B A D A C".Split(' ');
var unique_items = new HashSet<string>(items);
foreach (string s in unique_items)
    Console.WriteLine(s);

prints

A
B
D
C

Selecting only numeric columns from a data frame

The library PCAmixdata has functon splitmix that splits quantitative(Numerical data) and qualitative (Categorical data) of a given dataframe "YourDataframe" as shown below:

install.packages("PCAmixdata")
library(PCAmixdata)
split <- splitmix(YourDataframe)
X1 <- split$X.quanti(Gives numerical columns in the dataset) 
X2 <- split$X.quali (Gives categorical columns in the dataset)

Tkinter: How to use threads to preventing main event loop from "freezing"

I have used RxPY which has some nice threading functions to solve this in a fairly clean manner. No queues, and I have provided a function that runs on the main thread after completion of the background thread. Here is a working example:

import rx
from rx.scheduler import ThreadPoolScheduler
import time
import tkinter as tk

class UI:
   def __init__(self):
      self.root = tk.Tk()
      self.pool_scheduler = ThreadPoolScheduler(1) # thread pool with 1 worker thread
      self.button = tk.Button(text="Do Task", command=self.do_task).pack()

   def do_task(self):
      rx.empty().subscribe(
         on_completed=self.long_running_task, 
         scheduler=self.pool_scheduler
      )

   def long_running_task(self):
      # your long running task here... eg:
      time.sleep(3)
      # if you want a callback on the main thread:
      self.root.after(5, self.on_task_complete)

   def on_task_complete(self):
       pass # runs on main thread

if __name__ == "__main__":
    ui = UI()
    ui.root.mainloop()

Another way to use this construct which might be cleaner (depending on preference):

tk.Button(text="Do Task", command=self.button_clicked).pack()

...

def button_clicked(self):

   def do_task(_):
      time.sleep(3) # runs on background thread
             
   def on_task_done():
      pass # runs on main thread

   rx.just(1).subscribe(
      on_next=do_task, 
      on_completed=lambda: self.root.after(5, on_task_done), 
      scheduler=self.pool_scheduler
   )

Get integer value from string in swift

In Swift 3.0

Type 1: Convert NSString to String

    let stringNumb:NSString = "1357"
    let someNumb = Int(stringNumb as String) // 1357 as integer

Type 2: If the String has Integer only

    let stringNumb = "1357"
    let someNumb = Int(stringNumb) // 1357 as integer

Type 3: If the String has Float value

    let stringNumb = "13.57"
    if let stringToFloat = Float(stringNumb){
        let someNumb = Int(stringToFloat)// 13 as Integer
    }else{
       //do something if the stringNumb not have digit only. (i.e.,) let stringNumb = "13er4"
    }

Why is this rsync connection unexpectedly closed on Windows?

I had this error coming up between 2 Linux boxes. Easily solved by installing RSYNC on the remote box as well as the local one.

Getting an "ambiguous redirect" error

if you are using a variable name in the shell command, you must concatenate it with + sign.

for example :

if you have two files, and you are not going to hard code the file name, instead you want to use the variable name
"input.txt" = x
"output.txt" = y

then ('shell command within quotes' + x > + y)

it will work this way especially if you are using this inside a python program with os.system command probably

How do you do a deep copy of an object in .NET?

Building on Kilhoffer's solution...

With C# 3.0 you can create an extension method as follows:

public static class ExtensionMethods
{
    // Deep clone
    public static T DeepClone<T>(this T a)
    {
        using (MemoryStream stream = new MemoryStream())
        {
            BinaryFormatter formatter = new BinaryFormatter();
            formatter.Serialize(stream, a);
            stream.Position = 0;
            return (T) formatter.Deserialize(stream);
        }
    }
}

which extends any class that's been marked as [Serializable] with a DeepClone method

MyClass copy = obj.DeepClone();

git: fatal: I don't handle protocol '??http'

You can also use a text editor:

  • Paste the URL in the text editor
  • Copy the URL that was just pasted from the text editor
  • Paste it in the command line

Python Inverse of a Matrix

If you hate numpy, get out RPy and your local copy of R, and use it instead.

(I would also echo to make you you really need to invert the matrix. In R, for example, linalg.solve and the solve() function don't actually do a full inversion, since it is unnecessary.)

How do I use a file grep comparison inside a bash if/else statement?

if takes a command and checks its return value. [ is just a command.

if grep -q ...
then
  ....
else
  ....
fi

Converting cv::Mat to IplImage*

Mat image1;
IplImage* image2=cvCloneImage(&(IplImage)image1);

Guess this will do the job.

Edit: If you face compilation errors, try this way:

cv::Mat image1;
IplImage* image2;
image2 = cvCreateImage(cvSize(image1.cols,image1.rows),8,3);
IplImage ipltemp=image1;
cvCopy(&ipltemp,image2);

How can I get Git to follow symlinks?

What I did to add to get the files within a symlink into Git (I didn't use a symlink but):

sudo mount --bind SOURCEDIRECTORY TARGETDIRECTORY

Do this command in the Git-managed directory. TARGETDIRECTORY has to be created before the SOURCEDIRECTORY is mounted into it.

It works fine on Linux, but not on OS X! That trick helped me with Subversion too. I use it to include files from an Dropbox account, where a webdesigner does his/her stuff.

What is the difference between aggregation, composition and dependency?

Containment :- Here to access inner object we have to use outer object. We can reuse the contained object. Aggregation :- Here we can access inner object again and again without using outer object.

Read/write files within a Linux kernel module

Since version 4.14 of Linux kernel, vfs_read and vfs_write functions are no longer exported for use in modules. Instead, functions exclusively for kernel's file access are provided:

# Read the file from the kernel space.
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);

# Write the file from the kernel space.
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
            loff_t *pos);

Also, filp_open no longer accepts user-space string, so it can be used for kernel access directly (without dance with set_fs).

Make div fill remaining space along the main axis in flexbox

Basically I was trying to get my code to have a middle section on a 'row' to auto-adjust to the content on both sides (in my case, a dotted line separator). Like @Michael_B suggested, the key is using display:flex on the row container and at least making sure your middle container on the row has a flex-grow value of at least 1 higher than the outer containers (if outer containers don't have any flex-grow properties applied, middle container only needs 1 for flex-grow).

Here's a pic of what I was trying to do and sample code for how I solved it.

enter image description here

_x000D_
_x000D_
.row {
  background: lightgray;
  height: 30px;
  width: 100%;
  display: flex;
  align-items:flex-end;
  margin-top:5px;
}
.left {
  background:lightblue;
}
.separator{
  flex-grow:1;
  border-bottom:dotted 2px black;
}
.right {
  background:coral;
}
_x000D_
<div class="row">
  <div class="left">Left</div>
  <div class="separator"></div>
  <div class="right">Right With Text</div>
</div>
<div class="row">
  <div class="left">Left With More Text</div>
  <div class="separator"></div>
  <div class="right">Right</div>
</div>
<div class="row">
  <div class="left">Left With Text</div>
  <div class="separator"></div>
  <div class="right">Right With More Text</div>
</div>
_x000D_
_x000D_
_x000D_

Android Studio - Device is connected but 'offline'

Disabling and Enabling the Developer options and debug mode on the Android phone settings fixed the issue.

Fixed position but relative to container

Short answer: no. (It is now possible with CSS transform. See the edit below)

Long answer: The problem with using "fixed" positioning is that it takes the element out of flow. thus it can't be re-positioned relative to its parent because it's as if it didn't have one. If, however, the container is of a fixed, known width, you can use something like:

#fixedContainer {
  position: fixed;
  width: 600px;
  height: 200px;
  left: 50%;
  top: 0%;
  margin-left: -300px; /*half the width*/
}

http://jsfiddle.net/HFjU6/1/

Edit (03/2015):

This is outdated information. It is now possible to center content of an dynamic size (horizontally and vertically) with the help of the magic of CSS3 transform. The same principle applies, but instead of using margin to offset your container, you can use translateX(-50%). This doesn't work with the above margin trick because you don't know how much to offset it unless the width is fixed and you can't use relative values (like 50%) because it will be relative to the parent and not the element it's applied to. transform behaves differently. Its values are relative to the element they are applied to. Thus, 50% for transform means half the width of the element, while 50% for margin is half of the parent's width. This is an IE9+ solution

Using similar code to the above example, I recreated the same scenario using completely dynamic width and height:

.fixedContainer {
    background-color:#ddd;
    position: fixed;
    padding: 2em;
    left: 50%;
    top: 0%;
    transform: translateX(-50%);
}

If you want it to be centered, you can do that too:

.fixedContainer {
    background-color:#ddd;
    position: fixed;
    padding: 2em;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

Demos:

jsFiddle: Centered horizontally only
jsFiddle: Centered both horizontally and vertically
Original credit goes to user aaronk6 for pointing it out to me in this answer

gem install: Failed to build gem native extension (can't find header files)

This post helped me. Thanks a lot.

On Linux (Ubuntu 12.10) I needed to run

sudo apt-get install ruby
sudo apt-get install rubygems
sudo apt-get install ruby-dev

before I could succesfully run

sudo gem install jekyll

Getting "NoSuchMethodError: org.hamcrest.Matcher.describeMismatch" when running test in IntelliJ 10.5

Try

expect(new ThrowableMessageMatcher(new StringContains(message)))

instead of

expectMessage(message)

You may write a custom ExpectedException or utility method to wrap up the code.

Replace Multiple String Elements in C#

Quicker - no. More effective - yes, if you will use the StringBuilder class. With your implementation each operation generates a copy of a string which under circumstances may impair performance. Strings are immutable objects so each operation just returns a modified copy.

If you expect this method to be actively called on multiple Strings of significant length, it might be better to "migrate" its implementation onto the StringBuilder class. With it any modification is performed directly on that instance, so you spare unnecessary copy operations.

public static class StringExtention
{
    public static string clean(this string s)
    {
        StringBuilder sb = new StringBuilder (s);

        sb.Replace("&", "and");
        sb.Replace(",", "");
        sb.Replace("  ", " ");
        sb.Replace(" ", "-");
        sb.Replace("'", "");
        sb.Replace(".", "");
        sb.Replace("eacute;", "é");

        return sb.ToString().ToLower();
    }
}

Javascript "Cannot read property 'length' of undefined" when checking a variable's length

There's a difference between an empty string "" and an undefined variable. You should be checking whether or not theHref contains a defined string, rather than its lenght:

if(theHref){
   // ---
}

If you still want to check for the length, then do this:

if(theHref && theHref.length){
   // ...
}

How Do I 'git fetch' and 'git merge' from a Remote Tracking Branch (like 'git pull')

these are the commands:

git fetch origin
git merge origin/somebranch somebranch

if you do this on the second line:

git merge origin somebranch

it will try to merge the local master into your current branch.

The question, as I've understood it, was you fetched already locally and want to now merge your branch to the latest of the same branch.

set the width of select2 input (through Angular-ui directive)

You can try like this. It works for me

$("#MISSION_ID").select2();

On hide/show or ajax request, we have to reinitialize the select2 plugin

For example:

$("#offialNumberArea").show();
$("#eventNameArea").hide();

$('.selectCriteria').change(function(){
    var thisVal = $(this).val();
    if(thisVal == 'sailor'){
        $("#offialNumberArea").show();
        $("#eventNameArea").hide();
    }
    else
    {
        $("#offialNumberArea").hide();
        $("#eventNameArea").show();
        $("#MISSION_ID").select2();
    }
});

Address already in use: JVM_Bind java

In windows this scenario happens when Eclipse crashes without a clean shutdown it will have the local Jetty or Tomcat server keep running. When you reopen Eclipse and try to start server again this will lead to the "Address already in use: JVM_Bind"

You can solve this by opening Task Manager and find the javaw.exe process and ending it.

Then you can restart the server on Eclipse.

enter image description here

Java: convert seconds to minutes, hours and days

It should be like:

    public static void calculateTime(long seconds) {
            int day = (int)TimeUnit.SECONDS.toDays(seconds);        
            long hours = TimeUnit.SECONDS.toHours(seconds) - (day *24);
            long minute = TimeUnit.SECONDS.toMinutes(seconds) - (TimeUnit.SECONDS.toHours(seconds)* 60);
            long second = TimeUnit.SECONDS.toSeconds(seconds) - (TimeUnit.SECONDS.toMinutes(seconds) *60);

            System.out.println("Day " + day + " Hour " + hours + " Minute " + minute + " Seconds " + second);

        }

Explanation:

TimeUnit.SECONDS.toHours(seconds) will give you direct conversion from seconds to hours with out consideration for days. Minus the hours for days you already got i.e, day*24. You now got remaining hours. Same for minute and second. You need to minus the already got hour and minutes respectively.

How to extract string following a pattern with grep, regex or perl

If you're using Perl, download a module to parse the XML: XML::Simple, XML::Twig, or XML::LibXML. Don't re-invent the wheel.

How to understand nil vs. empty vs. blank in Ruby

Rails 4

an alternative to @corban-brook 's 'Array gotcha: blank?' for checking if an arrays only holds empty values and can be regarded as blank? true:

[ nil, '' ].all? &:blank? == true

one could also do:

[nil, '', "", " ",' '].reject(&:blank?).blank? == true

How to serve all existing static files directly with NGINX, but proxy the rest to a backend server.

Use try_files and named location block ('@apachesite'). This will remove unnecessary regex match and if block. More efficient.

location / {
    root /path/to/root/of/static/files;
    try_files $uri $uri/ @apachesite;

    expires max;
    access_log off;
}

location @apachesite {
    proxy_set_header X-Real-IP  $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_pass http://127.0.0.1:8080;
}

Update: The assumption of this config is that there doesn't exist any php script under /path/to/root/of/static/files. This is common in most modern php frameworks. In case your legacy php projects have both php scripts and static files mixed in the same folder, you may have to whitelist all of the file types you want nginx to serve.

When to use Task.Delay, when to use Thread.Sleep?

I want to add something. Actually, Task.Delay is a timer based wait mechanism. If you look at the source you would find a reference to a Timer class which is responsible for the delay. On the other hand Thread.Sleep actually makes current thread to sleep, that way you are just blocking and wasting one thread. In async programming model you should always use Task.Delay() if you want something(continuation) happen after some delay.

C# go to next item in list based on if statement in foreach

Use continue; instead of break; to enter the next iteration of the loop without executing any more of the contained code.

foreach (Item item in myItemsList)
{
   if (item.Name == string.Empty)
   {
      // Display error message and move to next item in list.  Skip/ignore all validation
      // that follows beneath
      continue;
   }

   if (item.Weight > 100)
   {
      // Display error message and move to next item in list.  Skip/ignore all validation
      // that follows beneath
      continue;
   }
}

Official docs are here, but they don't add very much color.

Securing a password in a properties file

Actually, this is a duplicate of Encrypt Password in Configuration Files?.

The best solution I found so far is in this answert: https://stackoverflow.com/a/1133815/1549977

Pros: Password is saved a a char array, not as a string. It's still not good, but better than anything else.

Single huge .css file vs. multiple smaller specific .css files?

here is the best way:

  1. create a general css file with all shared code
  2. insert all specific page css code into the same page, on the tag or using the attribute style="" for each page

on this way you have only one css with all shared code and an html page. by the way (and i know that this is not the right topic) you can also encode your images in base64 (but you can also do it with your js and css files). in this way you reduce even more http requests to 1.

Error:java: invalid source release: 8 in Intellij. What does it mean?

I had the same issue when "downgrading" a project from Java 8 to Java 6. The reason was that it was not changed at all places in IntelliJ.

In IntelliJ 13.1.4 I had to change Java and SDK version on the following places not to get this error:

  • File -> Project Structure -> Project Settings
  • File -> Project Structure -> Module Settings -> Tab: Sources: Language Level
  • File -> Project Structure -> Module Settings -> Tab: Dependencies: Module SDK
  • File -> Settings -> Compiler -> Java Compiler -> Target bytecode version

screen shot of File > Project Structure > Project

screen shot of File > Project Structure > Modules > Sources

screen shot of File > Project Structure > Modules > Dependencies

screen shot of File > Settings/Preferences > Compiler > Java Compiler

The last bullet was the one that was not updated in my case. Once I changed this, the error disappeared.

How can I run a PHP script inside a HTML file?

You can't run PHP in an html page ending with .html. Unless the page is actually PHP and the extension was changed with .htaccess from .php to .html

What you mean is:

index.html
<html>
...
<?php echo "Hello world";?> //This is impossible


index.php //The file extension can be changed using htaccess, ex: its type stays php but will be visible to visitors as index.html

<?php echo "Hello world";?>

How do I use raw_input in Python 3

How about the following one? Should allow you to use either raw_input or input in both Python2 and Python3 with the semantics of Python2's raw_input (aka the semantics of Python3's input)

# raw_input isn't defined in Python3.x, whereas input wasn't behaving like raw_input in Python 2.x
# this should make both input and raw_input work in Python 2.x/3.x like the raw_input from Python 2.x 
try: input = raw_input
except NameError: raw_input = input

"Too many characters in character literal error"

Here's an example:

char myChar = '|';
string myString = "||";

Chars are delimited by single quotes, and strings by double quotes.

The good news is C# switch statements work with strings!

switch (mytoken)
{
    case "==":
        //Something here.
        break;
    default:
        //Handle when no token is found.
        break;
}

Can I have onScrollListener for a ScrollView?

Every instance of View calls getViewTreeObserver(). Now when holding an instance of ViewTreeObserver, you can add an OnScrollChangedListener() to it using the method addOnScrollChangedListener().

You can see more information about this class here.

It lets you be aware of every scrolling event - but without the coordinates. You can get them by using getScrollY() or getScrollX() from within the listener though.

scrollView.getViewTreeObserver().addOnScrollChangedListener(new OnScrollChangedListener() {
    @Override
    public void onScrollChanged() {
        int scrollY = rootScrollView.getScrollY(); // For ScrollView
        int scrollX = rootScrollView.getScrollX(); // For HorizontalScrollView
        // DO SOMETHING WITH THE SCROLL COORDINATES
    }
});

Count character occurrences in a string in C++

public static void main(String[] args) {
        char[] array = "aabsbdcbdgratsbdbcfdgs".toCharArray();
        char[][] countArr = new char[array.length][2];
        int lastIndex = 0;
        for (char c : array) {
            int foundIndex = -1;
            for (int i = 0; i < lastIndex; i++) {
                if (countArr[i][0] == c) {
                    foundIndex = i;
                    break;
                }
            }
            if (foundIndex >= 0) {
                int a = countArr[foundIndex][1];
                countArr[foundIndex][1] = (char) ++a;
            } else {
                countArr[lastIndex][0] = c;
                countArr[lastIndex][1] = '1';
                lastIndex++;
            }
        }
        for (int i = 0; i < lastIndex; i++) {
            System.out.println(countArr[i][0] + " " + countArr[i][1]);
        }
    }

Service will not start: error 1067: the process terminated unexpectedly

I had this error, I looked into a log file C:\...\mysql\data\VM-IIS-Server.err and found this

2016-06-07 17:56:07 160c  InnoDB: Error: unable to create temporary file; errno: 2
2016-06-07 17:56:07 3392 [ERROR] Plugin 'InnoDB' init function returned error.
2016-06-07 17:56:07 3392 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-06-07 17:56:07 3392 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-06-07 17:56:07 3392 [ERROR] Aborting

The first line says "unable to create temporary file", it sounds like "insufficient privileges", first I tried to give access to mysql folder for my current user - no effect, then after some wandering around I came up to control panel->Administration->Services->Right Clicked MysqlService->Properties->Log On, switched to "This account", entered my username/password, clicked OK, and it woked!

Are there any free Xml Diff/Merge tools available?

Pretty Diff tool was created with XML in mind. Just ensure you click the option for "markup".

http://prettydiff.com/

Close Window from ViewModel

You can close the current window just by using the following code:

Application.Current.Windows[0].Close();

How to rotate a div using jQuery

EDIT: Updated for jQuery 1.8

Since jQuery 1.8 browser specific transformations will be added automatically. jsFiddle Demo

var rotation = 0;

jQuery.fn.rotate = function(degrees) {
    $(this).css({'transform' : 'rotate('+ degrees +'deg)'});
    return $(this);
};

$('.rotate').click(function() {
    rotation += 5;
    $(this).rotate(rotation);
});

EDIT: Added code to make it a jQuery function.

For those of you who don't want to read any further, here you go. For more details and examples, read on. jsFiddle Demo.

var rotation = 0;

jQuery.fn.rotate = function(degrees) {
    $(this).css({'-webkit-transform' : 'rotate('+ degrees +'deg)',
                 '-moz-transform' : 'rotate('+ degrees +'deg)',
                 '-ms-transform' : 'rotate('+ degrees +'deg)',
                 'transform' : 'rotate('+ degrees +'deg)'});
    return $(this);
};

$('.rotate').click(function() {
    rotation += 5;
    $(this).rotate(rotation);
});

EDIT: One of the comments on this post mentioned jQuery Multirotation. This plugin for jQuery essentially performs the above function with support for IE8. It may be worth using if you want maximum compatibility or more options. But for minimal overhead, I suggest the above function. It will work IE9+, Chrome, Firefox, Opera, and many others.


Bobby... This is for the people who actually want to do it in the javascript. This may be required for rotating on a javascript callback.

Here is a jsFiddle.

If you would like to rotate at custom intervals, you can use jQuery to manually set the css instead of adding a class. Like this! I have included both jQuery options at the bottom of the answer.

HTML

<div class="rotate">
    <h1>Rotatey text</h1>
</div>

CSS

/* Totally for style */
.rotate {
    background: #F02311;
    color: #FFF;
    width: 200px;
    height: 200px;
    text-align: center;
    font: normal 1em Arial;
    position: relative;
    top: 50px;
    left: 50px;
}

/* The real code */
.rotated {
    -webkit-transform: rotate(45deg);  /* Chrome, Safari 3.1+ */
    -moz-transform: rotate(45deg);  /* Firefox 3.5-15 */
    -ms-transform: rotate(45deg);  /* IE 9 */
    -o-transform: rotate(45deg);  /* Opera 10.50-12.00 */
    transform: rotate(45deg);  /* Firefox 16+, IE 10+, Opera 12.10+ */
}

jQuery

Make sure these are wrapped in $(document).ready

$('.rotate').click(function() {
    $(this).toggleClass('rotated');
});

Custom intervals

var rotation = 0;
$('.rotate').click(function() {
    rotation += 5;
    $(this).css({'-webkit-transform' : 'rotate('+ rotation +'deg)',
                 '-moz-transform' : 'rotate('+ rotation +'deg)',
                 '-ms-transform' : 'rotate('+ rotation +'deg)',
                 'transform' : 'rotate('+ rotation +'deg)'});
});

What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN?

An SQL JOIN clause is used to combine rows from two or more tables, based on a common field between them.

There are different types of joins available in SQL:

INNER JOIN: returns rows when there is a match in both tables.

LEFT JOIN: returns all rows from the left table, even if there are no matches in the right table.

RIGHT JOIN: returns all rows from the right table, even if there are no matches in the left table.

FULL JOIN: It combines the results of both left and right outer joins.

The joined table will contain all records from both the tables and fill in NULLs for missing matches on either side.

SELF JOIN: is used to join a table to itself as if the table were two tables, temporarily renaming at least one table in the SQL statement.

CARTESIAN JOIN: returns the Cartesian product of the sets of records from the two or more joined tables.

WE can take each first four joins in Details :

We have two tables with the following values.

TableA

id  firstName                  lastName
.......................................
1   arun                        prasanth                 
2   ann                         antony                   
3   sruthy                      abc                      
6   new                         abc                                           

TableB

id2 age Place
................
1   24  kerala
2   24  usa
3   25  ekm
5   24  chennai

....................................................................

INNER JOIN

Note :it gives the intersection of the two tables, i.e. rows they have common in TableA and TableB

Syntax

SELECT table1.column1, table2.column2...
  FROM table1
 INNER JOIN table2
    ON table1.common_field = table2.common_field;

Apply it in our sample table :

SELECT TableA.firstName,TableA.lastName,TableB.age,TableB.Place
  FROM TableA
 INNER JOIN TableB
    ON TableA.id = TableB.id2;

Result Will Be

firstName       lastName       age  Place
..............................................
arun            prasanth        24  kerala
ann             antony          24  usa
sruthy          abc             25  ekm

LEFT JOIN

Note : will give all selected rows in TableA, plus any common selected rows in TableB.

Syntax

SELECT table1.column1, table2.column2...
  FROM table1
  LEFT JOIN table2
    ON table1.common_field = table2.common_field;

Apply it in our sample table :

SELECT TableA.firstName,TableA.lastName,TableB.age,TableB.Place
  FROM TableA
  LEFT JOIN TableB
    ON TableA.id = TableB.id2;

Result

firstName                   lastName                    age   Place
...............................................................................
arun                        prasanth                    24    kerala
ann                         antony                      24    usa
sruthy                      abc                         25    ekm
new                         abc                         NULL  NULL

RIGHT JOIN

Note : will give all selected rows in TableB, plus any common selected rows in TableA.

Syntax

SELECT table1.column1, table2.column2...
  FROM table1
 RIGHT JOIN table2
    ON table1.common_field = table2.common_field;

Apply it in our sample table :

SELECT TableA.firstName,TableA.lastName,TableB.age,TableB.Place
  FROM TableA
 RIGHT JOIN TableB
    ON TableA.id = TableB.id2;

Result

firstName                   lastName                    age     Place
...............................................................................
arun                        prasanth                    24     kerala
ann                         antony                      24     usa
sruthy                      abc                         25     ekm
NULL                        NULL                        24     chennai

FULL JOIN

Note :It will return all selected values from both tables.

Syntax

SELECT table1.column1, table2.column2...
  FROM table1
  FULL JOIN table2
    ON table1.common_field = table2.common_field;

Apply it in our sample table :

SELECT TableA.firstName,TableA.lastName,TableB.age,TableB.Place
  FROM TableA
  FULL JOIN TableB
    ON TableA.id = TableB.id2;

Result

firstName                   lastName                    age    Place
...............................................................................
arun                        prasanth                    24    kerala
ann                         antony                      24    usa
sruthy                      abc                         25    ekm
new                         abc                         NULL  NULL
NULL                        NULL                        24    chennai

Interesting Fact

For INNER joins the order doesn't matter

For (LEFT, RIGHT or FULL) OUTER joins,the order matter

Better to go check this Link it will give you interesting details about join order

document.getElementById replacement in angular4 / typescript?

You can tag your DOM element using #someTag, then get it with @ViewChild('someTag').

See complete example:

import {AfterViewInit, Component, ElementRef, ViewChild} from '@angular/core';

@Component({
    selector: 'app',
    template: `
        <div #myDiv>Some text</div>
    `,
})
export class AppComponent implements AfterViewInit {
    @ViewChild('myDiv') myDiv: ElementRef;

    ngAfterViewInit() {
        console.log(this.myDiv.nativeElement.innerHTML);
    }
}

console.log will print Some text.

jQuery add class .active on menu

Setting the active menu, they have the many ways to do that. Now, I share you a way to set active menu by CSS.

    <a href="index.php?id=home">Home</a>
    <a href="index.php?id=news">News</a>
    <a href="index.php?id=about">About</a>

Now, you only set $_request["id"] == "home" thì echo "class='active'" , then we can do same with others.

<a href="index.php?id=home" <?php if($_REQUEST["id"]=="home"){echo "class='active'";}?>>Home</a>
<a href="index.php?id=news" <?php if($_REQUEST["id"]=="news"){echo "class='active'";}?>>News</a>
<a href="index.php?id=about" <?php if($_REQUEST["id"]=="about"){echo "class='active'";}?>>About</a>

I think it is useful with you.

Display Image On Text Link Hover CSS Only

CSS isn't going to be able to call other elements like that, you'll need to use JavaScript to reach beyond a child or sibling selector.

You could try something like this:

<a>Some Link
<div><img src="/you/image" /></div>
</a>

then...

a>div { display: none; }
a:hover>div { display: block; }

Convert timestamp to date in MySQL query

If the registration field is indeed of type TIMESTAMP you should be able to just do:

$sql = "SELECT user.email, 
           info.name, 
           DATE(user.registration), 
           info.news
      FROM user, 
           info 
     WHERE user.id = info.id ";

and the registration should be showing as yyyy-mm-dd

How do I sort a vector of pairs based on the second element of the pair?

You can use boost like this:

std::sort(a.begin(), a.end(), 
          boost::bind(&std::pair<int, int>::second, _1) <
          boost::bind(&std::pair<int, int>::second, _2));

I don't know a standard way to do this equally short and concise, but you can grab boost::bind it's all consisting of headers.

Changing the JFrame title

newTitle is a local variable where you create the fields. So when that functions ends, the variable newTitle, does not exist anymore. (The JTextField that was referenced by newTitle does still exist however.)

Thus, increase the scope of the variable, so that you can access it another method.

public SomeFrame extends JFrame {
   JTextField myTitle;//can be used anywhere in this class

   creationOfTheFields()
   {
   //other code
      myTitle = new JTextField("spam");  
      myTitle.setBounds(80, 40, 225, 20);
      options.add(myTitle);
   //blabla other code
   }

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

PHP new line break in emails

When we insert any line break with a programming language the char code for this is "\n". php does output that but html can't display that due to htmls line break is
. so easy way to do this job is replacing all the "\n" with "
". so the code should be

str_replace("\n","<br/>",$str);

after adding this code you wont have to use pre tag for all the output oparation.

copyed this ans from this website :

Should we pass a shared_ptr by reference or by value?

Pass by const reference, it's faster. If you need to store it, say in some container, the ref. count will be auto-magically incremented by the copy operation.

Simple working Example of json.net in VB.net

In Place of using this

MsgBox(json.SelectToken("Venue").SelectToken("ID"))

You can also use

MsgBox(json.SelectToken("Venue.ID"))

Difference between binary semaphore and mutex

In windows the difference is as below. MUTEX: process which successfully executes wait has to execute a signal and vice versa. BINARY SEMAPHORES: Different processes can execute wait or signal operation on a semaphore.

How to config routeProvider and locationProvider in angularJS?

@Simple-Solution

I use a simple Python HTTP server. When in the directory of the Angular app in question (using a MBP with Mavericks 10.9 and Python 2.x) I simply run

python -m SimpleHTTPServer 8080

And that sets up the simple server on port 8080 letting you visit localhost:8080 on your browser to view the app in development.

Hope that helped!

TypeError: 'builtin_function_or_method' object is not subscriptable

This error arises when you don't use brackets with pop operation. Write the code in this manner.

listb.pop(0)

This is a valid python expression.

How to declare a inline object with inline variables without a parent class

You can also do this:

var x = new object[] {
    new { firstName = "john", lastName = "walter" },
    new { brand = "BMW" }
};

And if they are the same anonymous type (firstName and lastName), you won't need to cast as object.

var y = new [] {
    new { firstName = "john", lastName = "walter" },
    new { firstName = "jill", lastName = "white" }
};

Initializing a member array in constructor initializer

You want to init an array of ints in your constructor? Point it to a static array.

class C 
{
public:
    int *cArray;

};

C::C {
    static int c_init[]{1,2,3};
    cArray = c_init;
}

How do you read a file into a list in Python?

To summarize a bit from what people have been saying:

f=open('data.txt', 'w') # will make a new file or erase a file of that name if it is present
f=open('data.txt', 'r') # will open a file as read-only
f=open('data.txt', 'a') # will open a file for appending (appended data goes to the end of the file)

If you wish have something in place similar to a try/catch

with open('data.txt') as f:
    for line in f:
        print line

I think @movieyoda code is probably what you should use however

Registering for Push Notifications in Xcode 8/Swift 3.0?

The answer from ast1 is very simple and useful. It works for me, thank you so much. I just want to poin it out here, so people who need this answer can find it easily. So, here is my code from registering local and remote (push) notification.

    //1. In Appdelegate: didFinishLaunchingWithOptions add these line of codes
    let mynotif = UNUserNotificationCenter.current()
    mynotif.requestAuthorization(options: [.alert, .sound, .badge]) {(granted, error) in }//register and ask user's permission for local notification

    //2. Add these functions at the bottom of your AppDelegate before the last "}"
    func application(_ application: UIApplication, didRegister notificationSettings: UNNotificationSettings) {
        application.registerForRemoteNotifications()//register for push notif after users granted their permission for showing notification
}
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    let tokenString = deviceToken.reduce("", {$0 + String(format: "%02X", $1)})
    print("Device Token: \(tokenString)")//print device token in debugger console
}
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
    print("Failed to register: \(error)")//print error in debugger console
}

Is it possible to decrypt SHA1

Since SHA-1 maps several byte sequences to one, you can't "decrypt" a hash, but in theory you can find collisions: strings that have the same hash.

It seems that breaking a single hash would cost about 2.7 million dollars worth of computer time currently, so your efforts are probably better spent somewhere else.

event Action<> vs event EventHandler<>

The advantage of a wordier approach comes when your code is inside a 300,000 line project.

Using the action, as you have, there is no way to tell me what bool, int, and Blah are. If your action passed an object that defined the parameters then ok.

Using an EventHandler that wanted an EventArgs and if you would complete your DiagnosticsArgs example with getters for the properties that commented their purpose then you application would be more understandable. Also, please comment or fully name the arguments in the DiagnosticsArgs constructor.

How to secure the ASP.NET_SessionId cookie?

To add the ; secure suffix to the Set-Cookie http header I simply used the <httpCookies> element in the web.config:

<system.web>
  <httpCookies httpOnlyCookies="true" requireSSL="true" />
</system.web>

IMHO much more handy than writing code as in the article of Anubhav Goyal.

See: http://msdn.microsoft.com/en-us/library/ms228262(v=vs.100).aspx

Laravel migration: unique key is too long, even if specified

Going to your config/database.php and change the charset and collation from utf8mb4 to utf8

'charset' => 'utf8',
'collation' => 'utf8_unicode_ci',

My problem solved using this method, good luck dude!

Could not find method android() for arguments

My issue was inside of my app.gradle. I ran into this issue when I moved

apply plugin: "com.android.application"

from the top line to below a line with

apply from:

I switched the plugin back to the top and violá

My exact error was

Could not find method android() for arguments [dotenv_wke4apph61tdae6bfodqe7sj$_run_closure1@5d9d91a5] on project ':app' of type org.gradle.api.Project.

The top of my app.gradle now looks like this

project.ext.envConfigFiles = [
        debug: ".env",
        release: ".env",
        anothercustombuild: ".env",
]


apply from: project(':react-native-config').projectDir.getPath() + "/dotenv.gradle"
apply plugin: "com.android.application"

WinError 2 The system cannot find the file specified (Python)

I believe you need to .f file as a parameter, not as a command-single-string. same with the "--domain "+i, which i would split in two elements of the list. Assuming that:

  • you have the path set for FORTRAN executable,
  • the ~/ is indeed the correct way for the FORTRAN executable

I would change this line:

subprocess.Popen(["FORTRAN ~/C:/Users/Vishnu/Desktop/Fortran_Program_Rum/phase1.f", "--domain "+i])

to

subprocess.Popen(["FORTRAN", "~/C:/Users/Vishnu/Desktop/Fortran_Program_Rum/phase1.f", "--domain", i])

If that doesn't work, you should do a os.path.exists() for the .f file, and check that you can launch the FORTRAN executable without any path, and set the path or system path variable accordingly

[EDIT 6-Mar-2017]

As the exception, detailed in the original post, is a python exception from subprocess; it is likely that the WinError 2 is because it cannot find FORTRAN

I highly suggest that you specify full path for your executable:

for i in input:
    exe = r'c:\somedir\fortrandir\fortran.exe'
    fortran_script = r'~/C:/Users/Vishnu/Desktop/Fortran_Program_Rum/phase1.f'
    subprocess.Popen([exe, fortran_script, "--domain", i])

if you need to convert the forward-slashes to backward-slashes, as suggested in one of the comments, you can do this:

for i in input:
    exe = os.path.normcase(r'c:\somedir\fortrandir\fortran.exe')
    fortran_script = os.path.normcase(r'~/C:/Users/Vishnu/Desktop/Fortran_Program_Rum/phase1.f')
    i = os.path.normcase(i)
    subprocess.Popen([exe, fortran_script, "--domain", i])

[EDIT 7-Mar-2017]

The following line is incorrect:

exe = os.path.normcase(r'~/C:/Program Files (x86)/Silverfrost/ftn95.exe'

I am not sure why you have ~/ as a prefix for every path, don't do that.

for i in input:
    exe = os.path.normcase(r'C:/Program Files (x86)/Silverfrost/ftn95.exe'
    fortran_script = os.path.normcase(r'C:/Users/Vishnu/Desktop/Fortran_Program_Rum/phase1.f')
    i = os.path.normcase(i)
    subprocess.Popen([exe, fortran_script, "--domain", i])

[2nd EDIT 7-Mar-2017]

I do not know this FORTRAN or ftn95.exe, does it need a shell to function properly?, in which case you need to launch as follows:

subprocess.Popen([exe, fortran_script, "--domain", i], shell = True)

You really need to try to launch the command manually from the working directory which your python script is operating from. Once you have the command which is actually working, then build up the subprocess command.

Jquery - animate height toggle

You can also use this trick: replace

$("#topbar").click(function(){

by

$(document).on("click", "#topbar", function(){

This will bind an event on a not loaded yet object... ;)

Stupid error: Failed to load resource: net::ERR_CACHE_MISS

I solved this error with clearing cache and restarting chrome. Hope they will fix it in ver 40.

The HTTP request is unauthorized with client authentication scheme 'Negotiate'. The authentication header received from the server was 'NTLM'

Not this exact problem, but this is the top result when googling for almost the exact same error:

If you see this problem calling a WCF Service hosted on the same machine, you may need to populate the BackConnectionHostNames registry key

  1. In regedit, locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa\MSV1_0
  2. Right-click MSV1_0, point to New, and then click Multi-String Value.
  3. In the Name column, type BackConnectionHostNames, and then press ENTER.
  4. Right-click BackConnectionHostNames, and then click Modify. In the Value data box, type the CNAME or the DNS alias, that is used for the local shares on the computer, and then click OK.
    • Type each host name on a separate line.

See Calling WCF service hosted in IIS on the same machine as client throws authentication error for details.

Error - is not marked as serializable

Leaving my specific solution of this for prosperity, as it's a tricky version of this problem:

Type 'System.Linq.Enumerable+WhereSelectArrayIterator[T...] was not marked as serializable

Due to a class with an attribute IEnumerable<int> eg:

[Serializable]
class MySessionData{
    public int ID;
    public IEnumerable<int> RelatedIDs; //This can be an issue
}

Originally the problem instance of MySessionData was set from a non-serializable list:

MySessionData instance = new MySessionData(){ 
    ID = 123,
    RelatedIDs = nonSerizableList.Select<int>(item => item.ID)
};

The cause here is the concrete class that the Select<int>(...) returns, has type data that's not serializable, and you need to copy the id's to a fresh List<int> to resolve it.

RelatedIDs = nonSerizableList.Select<int>(item => item.ID).ToList();

Difference between static, auto, global and local variable in the context of c and c++

Difference is static variables are those variables: which allows a value to be retained from one call of the function to another. But in case of local variables the scope is till the block/ function lifetime.

For Example:

#include <stdio.h>

void func() {
    static int x = 0; // x is initialized only once across three calls of func()
    printf("%d\n", x); // outputs the value of x
    x = x + 1;
}

int main(int argc, char * const argv[]) {
    func(); // prints 0
    func(); // prints 1
    func(); // prints 2
    return 0;
}

How to uninstall pip on OSX?

The first thing you should try is:

sudo pip uninstall pip

On many environments that doesn't work. So given the lack of info on that problem, I ended up removing pip manually from /usr/local/bin.

How to use both onclick and target="_blank"

Just use window.open():

window.open('Prosjektplan.pdf')

Anyway, what guys are saying on comments is true. You better use <a target="_blank"> instead of click events.

HTML - Change\Update page contents without refreshing\reloading the page

jQuery will do the job. You can use either jQuery.ajax function, which is general one for performing ajax calls, or its wrappers: jQuery.get, jQuery.post for getting/posting data. Its very easy to use, for example, check out this tutorial, which shows how to use jQuery with PHP.

Using the star sign in grep

Try grep -E for extended regular expression support

Also take a look at:

The grep man page

Ant error when trying to build file, can't find tools.jar?

Java ships in 2 versions: JRE & SDK (used to be called JDK)

The JRE in addition to not containing the compiler, also doesn't contain all of the libraries available in the JDK (tools.jar is one of them)

When you download Java at: http://java.sun.com/javase/downloads/index.jsp, make sure to select the JDK version and install it. If you have both a JDK & JRE, make sure that ANT is using the JDK, you can check JAVA_HOME (environment variable), and on the commandline if you do "javac -version" you should get a version description.

Enable the display of line numbers in Visual Studio

In Visual Studio 2013 & 2015 :

Tools -> Options -> Text Editor -> All Languages -> check Line Numbers enter image description here

force Maven to copy dependencies into target/lib

Take a look at the Maven dependency plugin, specifically, the dependency:copy-dependencies goal. Take a look at the example under the heading The dependency:copy-dependencies mojo. Set the outputDirectory configuration property to ${basedir}/target/lib (I believe, you'll have to test).

Hope this helps.

jQuery Validation using the class instead of the name value

Here's my solution (requires no jQuery... just JavaScript):

function argsToArray(args) {
  var r = []; for (var i = 0; i < args.length; i++)
    r.push(args[i]);
  return r;
}
function bind() {
  var initArgs = argsToArray(arguments);
  var fx =        initArgs.shift();
  var tObj =      initArgs.shift();
  var args =      initArgs;
  return function() {
    return fx.apply(tObj, args.concat(argsToArray(arguments)));
  };
}
var salutation = argsToArray(document.getElementsByClassName('salutation'));
salutation.forEach(function(checkbox) {
  checkbox.addEventListener('change', bind(function(checkbox, salutation) {
    var numChecked = salutation.filter(function(checkbox) { return checkbox.checked; }).length;
    if (numChecked >= 4)
      checkbox.checked = false;
  }, null, checkbox, salutation), false);
});

Put this in a script block at the end of <body> and the snippet will do its magic, limiting the number of checkboxes checked in maximum to three (or whatever number you specify).

Here, I'll even give you a test page (paste it into a file and try it):

<!DOCTYPE html><html><body>
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<input type="checkbox" class="salutation">
<script>
    function argsToArray(args) {
      var r = []; for (var i = 0; i < args.length; i++)
        r.push(args[i]);
      return r;
    }
    function bind() {
      var initArgs = argsToArray(arguments);
      var fx =        initArgs.shift();
      var tObj =      initArgs.shift();
      var args =      initArgs;
      return function() {
        return fx.apply(tObj, args.concat(argsToArray(arguments)));
      };
    }
    var salutation = argsToArray(document.getElementsByClassName('salutation'));
    salutation.forEach(function(checkbox) {
      checkbox.addEventListener('change', bind(function(checkbox, salutation) {
        var numChecked = salutation.filter(function(checkbox) { return checkbox.checked; }).length;
        if (numChecked >= 3)
          checkbox.checked = false;
      }, null, checkbox, salutation), false);
    });
</script></body></html>

What are some good SSH Servers for windows?

I've been using Bitvise SSH Server for a number of years. It is a wonderful product and it is easy to setup and maintain. It gives you great control over how users connect to the server with support for security groups.

How do I print uint32_t and uint16_t variables value?

You need to include inttypes.h if you want all those nifty new format specifiers for the intN_t types and their brethren, and that is the correct (ie, portable) way to do it, provided your compiler complies with C99. You shouldn't use the standard ones like %d or %u in case the sizes are different to what you think.

It includes stdint.h and extends it with quite a few other things, such as the macros that can be used for the printf/scanf family of calls. This is covered in section 7.8 of the ISO C99 standard.

For example, the following program:

#include <stdio.h>
#include <inttypes.h>
int main (void) {
    uint32_t a=1234;
    uint16_t b=5678;
    printf("%" PRIu32 "\n",a);
    printf("%" PRIu16 "\n",b);
    return 0;
}

outputs:

1234
5678

How to compare two columns in Excel (from different sheets) and copy values from a corresponding column if the first two columns match?

As kmcamara discovered, this is exactly the kind of problem that VLOOKUP is intended to solve, and using vlookup is arguably the simplest of the alternative ways to get the job done.

In addition to the three parameters for lookup_value, table_range to be searched, and the column_index for return values, VLOOKUP takes an optional fourth argument that the Excel documentation calls the "range_lookup".

Expanding on deathApril's explanation, if this argument is set to TRUE (or 1) or omitted, the table range must be sorted in ascending order of the values in the first column of the range for the function to return what would typically be understood to be the "correct" value. Under this default behavior, the function will return a value based upon an exact match, if one is found, or an approximate match if an exact match is not found.

If the match is approximate, the value that is returned by the function will be based on the next largest value that is less than the lookup_value. For example, if "12AT8003" were missing from the table in Sheet 1, the lookup formulas for that value in Sheet 2 would return '2', since "12AT8002" is the largest value in the lookup column of the table range that is less than "12AT8003". (VLOOKUP's default behavior makes perfect sense if, for example, the goal is to look up rates in a tax table.)

However, if the fourth argument is set to FALSE (or 0), VLOOKUP returns a looked-up value only if there is an exact match, and an error value of #N/A if there is not. It is now the usual practice to wrap an exact VLOOKUP in an IFERROR function in order to catch the no-match gracefully. Prior to the introduction of IFERROR, no matches were checked with an IF function using the VLOOKUP formula once to check whether there was a match, and once to return the actual match value.

Though initially harder to master, deusxmach1na's proposed solution is a variation on a powerful set of alternatives to VLOOKUP that can be used to return values for a column or list to the left of the lookup column, expanded to handle cases where an exact match on more than one criterion is needed, or modified to incorporate OR as well as AND match conditions among multiple criteria.

Repeating kcamara's chosen solution, the VLOOKUP formula for this problem would be:

   =VLOOKUP(A1,Sheet1!A$1:B$600,2,FALSE)

How to get everything after a certain character?

Another simple way, using strchr() or strstr():

$str = '233718_This_is_a_string';

echo ltrim(strstr($str, '_'), '_'); // This_is_a_string

Maven compile with multiple src directories

This also works with maven by defining the resources tag. You can name your src folder names whatever you like.

    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.java</include>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
        </resource>

        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>**/*.java</include>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
        </resource>

        <resource>
            <directory>src/main/generated</directory>
            <includes>
                <include>**/*.java</include>
                <include>**/*.properties</include>
                <include>**/*.xml</include>
            </includes>
        </resource>
    </resources>

new DateTime() vs default(DateTime)

The answer is no. Keep in mind that in both cases, mdDate.Kind = DateTimeKind.Unspecified.

Therefore it may be better to do the following:

DateTime myDate = new DateTime(1, 1, 1, 0, 0, 0, DateTimeKind.Utc);

The myDate.Kind property is readonly, so it cannot be changed after the constructor is called.

C++ - Assigning null to a std::string

The else case is unncecessary, when you create a string object it is empty by default.

What is the difference between `throw new Error` and `throw someObject`?

throw "I'm Evil"

throw will terminate the further execution & expose message string on catch the error.

_x000D_
_x000D_
try {
  throw "I'm Evil"
  console.log("You'll never reach to me", 123465)
} catch (e) {
  console.log(e); // I'm Evil
}
_x000D_
_x000D_
_x000D_

Console after throw will never be reached cause of termination.


throw new Error("I'm Evil")

throw new Error exposes an error event with two params name & message. It also terminate further execution

_x000D_
_x000D_
try {
  throw new Error("I'm Evil")
  console.log("You'll never reach to me", 123465)
} catch (e) {
  console.log(e.name, e.message); // Error I'm Evil
}
_x000D_
_x000D_
_x000D_

throw Error("I'm Evil")

And just for completeness, this works also, though is not technically the correct way to do it -

_x000D_
_x000D_
try {
  throw Error("I'm Evil")
  console.log("You'll never reach to me", 123465)
} catch (e) {
  console.log(e.name, e.message); // Error I'm Evil
}

console.log(typeof(new Error("hello"))) // object
console.log(typeof(Error)) // function
_x000D_
_x000D_
_x000D_

Convert Xml to Table SQL Server

This is the answer, hope it helps someone :)

First there are two variations on how the xml can be written:

1

<row>
    <IdInvernadero>8</IdInvernadero>
    <IdProducto>3</IdProducto>
    <IdCaracteristica1>8</IdCaracteristica1>
    <IdCaracteristica2>8</IdCaracteristica2>
    <Cantidad>25</Cantidad>
    <Folio>4568457</Folio>
</row>
<row>
    <IdInvernadero>3</IdInvernadero>
    <IdProducto>3</IdProducto>
    <IdCaracteristica1>1</IdCaracteristica1>
    <IdCaracteristica2>2</IdCaracteristica2>
    <Cantidad>72</Cantidad>
    <Folio>4568457</Folio>
</row>

Answer:

SELECT  
       Tbl.Col.value('IdInvernadero[1]', 'smallint'),  
       Tbl.Col.value('IdProducto[1]', 'smallint'),  
       Tbl.Col.value('IdCaracteristica1[1]', 'smallint'),
       Tbl.Col.value('IdCaracteristica2[1]', 'smallint'),
       Tbl.Col.value('Cantidad[1]', 'int'),
       Tbl.Col.value('Folio[1]', 'varchar(7)')
FROM   @xml.nodes('//row') Tbl(Col)  

2.

<row IdInvernadero="8" IdProducto="3" IdCaracteristica1="8" IdCaracteristica2="8" Cantidad ="25" Folio="4568457" />                         
<row IdInvernadero="3" IdProducto="3" IdCaracteristica1="1" IdCaracteristica2="2" Cantidad ="72" Folio="4568457" />

Answer:

SELECT  
       Tbl.Col.value('@IdInvernadero', 'smallint'),  
       Tbl.Col.value('@IdProducto', 'smallint'),  
       Tbl.Col.value('@IdCaracteristica1', 'smallint'),
       Tbl.Col.value('@IdCaracteristica2', 'smallint'),
       Tbl.Col.value('@Cantidad', 'int'),
       Tbl.Col.value('@Folio', 'varchar(7)')

FROM   @xml.nodes('//row') Tbl(Col)

Taken from:

  1. http://kennyshu.blogspot.com/2007/12/convert-xml-file-to-table-in-sql-2005.html

  2. http://msdn.microsoft.com/en-us/library/ms345117(SQL.90).aspx

Swap DIV position with CSS only

Someone linked me this: What is the best way to move an element that's on the top to the bottom in Responsive design.

The solution in that worked perfectly. Though it doesn’t support old IE, that doesn’t matter for me, since I’m using responsive design for mobile. And it works for most mobile browsers.

Basically, I had this:

@media (max-width: 30em) {
  .container {
    display: -webkit-box;
    display: -moz-box;
    display: -ms-flexbox;
    display: -webkit-flex;
    display: flex;
    -webkit-box-orient: vertical;
    -moz-box-orient: vertical;
    -webkit-flex-direction: column;
    -ms-flex-direction: column;
    flex-direction: column;
    /* optional */
    -webkit-box-align: start;
    -moz-box-align: start;
    -ms-flex-align: start;
    -webkit-align-items: flex-start;
    align-items: flex-start;
  }

  .container .first_div {
    -webkit-box-ordinal-group: 2;
    -moz-box-ordinal-group: 2;
    -ms-flex-order: 2;
    -webkit-order: 2;
    order: 2;
  }

  .container .second_div {
    -webkit-box-ordinal-group: 1;
    -moz-box-ordinal-group: 1;
    -ms-flex-order: 1;
    -webkit-order: 1;
    order: 1;
  }
}

This worked better than floats for me, because I needed them stacked on top of each other and I had about five different divs that I had to swap around the position of.

passing argument to DialogFragment

Using newInstance

public static MyDialogFragment newInstance(int num) {
    MyDialogFragment f = new MyDialogFragment();

    // Supply num input as an argument.
    Bundle args = new Bundle();
    args.putInt("num", num);
    f.setArguments(args);

    return f;
}

And get the Args like this

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mNum = getArguments().getInt("num");
    ...
}

See the full example here
http://developer.android.com/reference/android/app/DialogFragment.html