SyntaxFix

Programs & Examples On #Reinterpret cast

A C++ operator that simply allows the conversion between types by reinterpreting the underlying bit pattern. In general use, this amounts a pointer to be converted into any other pointer type and it can also allow an integral type to be converted into any pointer type and vice versa.

When to use reinterpret_cast?

You could use reinterprete_cast to check inheritance at compile time.
Look here: Using reinterpret_cast to check inheritance at compile time

Difference between "managed" and "unmanaged"

This is more general than .NET and Windows. Managed is an environment where you have automatic memory management, garbage collection, type safety, ... unmanaged is everything else. So for example .NET is a managed environment and C/C++ is unmanaged.

How to show disable HTML select option in by default?

You can set which option is selected by default like this:

<option value="" selected>Choose Tagging</option>

I would suggest using javascript and JQuery to observe for click event and disable the first option after another has been selected: First, give the element an ID like so: 

<select id="option_select" name="tagging">

and the option an id : 

<option value="" id="initial">Choose Tagging</option>

then:

<script type="text/javascript">

$('option_select').observe(click, handleClickFunction);

Then you just create the function:

function handleClickFunction () {

if ($('option_select').value !== "option_select") 
{
   $('initial').disabled=true; }
}

Python how to write to a binary file?

Use pickle, like this: import pickle

Your code would look like this:

import pickle
mybytes = [120, 3, 255, 0, 100]
with open("bytesfile", "wb") as mypicklefile:
    pickle.dump(mybytes, mypicklefile)

To read the data back, use the pickle.load method

Access to the path denied error in C#

If your problem persist with all those answers, try to change the file attribute to:

File.SetAttributes(yourfile, FileAttributes.Normal);

How to fix Ora-01427 single-row subquery returns more than one row in select?

Use the following query:

SELECT E.I_EmpID AS EMPID,
       E.I_EMPCODE AS EMPCODE,
       E.I_EmpName AS EMPNAME,
       REPLACE(TO_CHAR(A.I_REQDATE, 'DD-Mon-YYYY'), ' ', '') AS FROMDATE,
       REPLACE(TO_CHAR(A.I_ENDDATE, 'DD-Mon-YYYY'), ' ', '') AS TODATE,
       TO_CHAR(NOD) AS NOD,
       DECODE(A.I_DURATION,
              'FD',
              'FullDay',
              'FN',
              'ForeNoon',
              'AN',
              'AfterNoon') AS DURATION,
       L.I_LeaveType AS LEAVETYPE,
       REPLACE(TO_CHAR((SELECT max(C.I_WORKDATE)
                         FROM T_COMPENSATION C
                        WHERE C.I_COMPENSATEDDATE = A.I_REQDATE
                          AND C.I_EMPID = A.I_EMPID),
                       'DD-Mon-YYYY'),
               ' ',
               '') AS WORKDATE,
       A.I_REASON AS REASON,
       AP.I_REJECTREASON AS REJECTREASON
  FROM T_LEAVEAPPLY A
 INNER JOIN T_EMPLOYEE_MS E
    ON A.I_EMPID = E.I_EmpID
   AND UPPER(E.I_IsActive) = 'YES'
   AND A.I_STATUS = '1'
 INNER JOIN T_LeaveType_MS L
    ON A.I_LEAVETYPEID = L.I_LEAVETYPEID
  LEFT OUTER JOIN T_APPROVAL AP
    ON A.I_REQDATE = AP.I_REQDATE
   AND A.I_EMPID = AP.I_EMPID
   AND AP.I_APPROVALSTATUS = '1'
 WHERE E.I_EMPID <> '22'
 ORDER BY A.I_REQDATE DESC

The trick is to force the inner query return only one record by adding an aggregate function (I have used max() here). This will work perfectly as far as the query is concerned, but, honestly, OP should investigate why the inner query is returning multiple records by examining the data. Are these multiple records really relevant business wise?

Check if a JavaScript string is a URL

If you can change the input type, I think this solution would be much easier:

You can simple use type="url" in your input and the check it with checkValidity() in js

E.g:

your.html

<input id="foo" type="url">

your.js

// The selector is JQuery, but the function is plain JS
$("#foo").on("keyup", function() {
    if (this.checkValidity()) {
        // The url is valid
    } else {
        // The url is invalid
    }
});

Laravel - Forbidden You don't have permission to access / on this server

It was solved for me with the Laravel default public/.htaccess file adding an extra line:

The /public/.htaccess file remains as follows:

<IfModule mod_rewrite.c>
    <IfModule mod_negotiation.c>
        Options -MultiViews
    </IfModule>

    RewriteEngine On
    DirectoryIndex index.php # This line does the trick

    # Redirect Trailing Slashes If Not A Folder...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)/$ /$1 [L,R=301]

    # Handle Front Controller...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.php [L]

    # Handle Authorization Header
    RewriteCond %{HTTP:Authorization} .
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
</IfModule>

Django DB Settings 'Improperly Configured' Error

On Django 1.9, I tried django-admin runserver and got the same error, but when I used python manage.py runserver I got the intended result. This may solve this error for a lot of people!

How to convert a boolean array to an int array

I know you asked for non-looping solutions, but the only solutions I can come up with probably loop internally anyway:

map(int,y)

or:

[i*1 for i in y]

or:

import numpy
y=numpy.array(y)
y*1

How to disable mouse scroll wheel scaling with Google Maps API

As of now (October 2017) Google has implemented a specific property to handle the zooming/scrolling, called gestureHandling. Its purpose is to handle mobile devices operation, but it modifies the behaviour for desktop browsers as well. Here it is from official documentation:

function initMap() {
  var locationRio = {lat: -22.915, lng: -43.197};
  var map = new google.maps.Map(document.getElementById('map'), {
    zoom: 13,
    center: locationRio,
    gestureHandling: 'none'
});

The available values for gestureHandling are:

  • 'greedy': The map always pans (up or down, left or right) when the user swipes (drags on) the screen. In other words, both a one-finger swipe and a two-finger swipe cause the map to pan.
  • 'cooperative': The user must swipe with one finger to scroll the page and two fingers to pan the map. If the user swipes the map with one finger, an overlay appears on the map, with a prompt telling the user to use two fingers to move the map. On desktop applications, users can zoom or pan the map by scrolling while pressing a modifier key (the ctrl or ? key).
  • 'none': This option disables panning and pinching on the map for mobile devices, and dragging of the map on desktop devices.
  • 'auto' (default): Depending on whether the page is scrollable, the Google Maps JavaScript API sets the gestureHandling property to either 'cooperative' or 'greedy'

In short, you can easily force the setting to "always zoomable" ('greedy'), "never zoomable" ('none'), or "user must press CRTL/? to enable zoom" ('cooperative').

How to save CSS changes of Styles panel of Chrome Developer Tools?

UPDATE 2019: As other answers are bit outdated, I'll add updated one here. In latest version there's no need to map the chrome folder to filesystem.

enter image description here

So, suppose I have a web folder containing HTML,CSS,JS files in desktop which i want to be updated when I make changes in chrome:=

1) You'd need a running local server like node etc, alternatively this vscode extension creates the server for you: live server VSCode extension, install it, run the server.

2) load the html page in chrome from running local server.

3) Open devTools->Sources->Filesystem->Add folder to workspace

enter image description here

4) Add the folder which is used in running local server. No additional mapping is required in latest chrome! Ta-da!

More on it Edit Files With Workspaces

Note that the changes made on the styles tab will NOT reflect on the filesystem files.
enter image description here
Instead you need to go to devtools->source->your_folder and then make your changes there and reload the page to see the effect.

Link error "undefined reference to `__gxx_personality_v0'" and g++

It sounds like you're trying to link with your resulting object file with gcc instead of g++:

Note that programs using C++ object files must always be linked with g++, in order to supply the appropriate C++ libraries. Attempting to link a C++ object file with the C compiler gcc will cause "undefined reference" errors for C++ standard library functions:

$ g++ -Wall -c hello.cc
$ gcc hello.o       (should use g++)
hello.o: In function `main':
hello.o(.text+0x1b): undefined reference to `std::cout'
.....
hello.o(.eh_frame+0x11):
  undefined reference to `__gxx_personality_v0'

Source: An Introduction to GCC - for the GNU compilers gcc and g++

Remove all newlines from inside a string

strip only removes characters from the beginning and end of a string. You want to use replace:

str2 = str.replace("\n", "")
re.sub('\s{2,}', ' ', str) # To remove more than one space

Installing Python library from WHL file

From How do I install a Python package with a .whl file? [sic], How do I install a Python package USING a .whl file ?

For all Windows platforms:

1) Download the .WHL package install file.

2) Make Sure path [C:\Progra~1\Python27\Scripts] is in the system PATH string. This is for using both [pip.exe] and [easy-install.exe].

3) Make sure the latest version of pip.EXE is now installed. At this time of posting:

pip.EXE --version

  pip 9.0.1 from C:\PROGRA~1\Python27\lib\site-packages (python 2.7)

4) Run pip.EXE in an Admin command shell.

 - Open an Admin privileged command shell.

 > easy_install.EXE --upgrade  pip

 - Check the pip.EXE version:
 > pip.EXE --version

 pip 9.0.1 from C:\PROGRA~1\Python27\lib\site-packages (python 2.7)

 > pip.EXE install --use-wheel --no-index 
     --find-links="X:\path to wheel file\DownloadedWheelFile.whl"

Be sure to double-quote paths or path\filenames with embedded spaces in them ! Alternatively, use the MSW 'short' paths and filenames.

Python: How to ignore an exception and proceed?

Try this:

try:
    blah()
except:
    pass

Best way to get user GPS location in background in Android

Download the source code from here (Get Current Location Using Background Service)

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="servicetutorial.service">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity"
            android:theme="@android:style/Theme.Translucent.NoTitleBar">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service android:name=".GoogleService"></service>
    </application>

</manifest>

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:background="#ffffff"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="#3F51B5"
        android:text="Location using service"
        android:textColor="#ffffff"
        android:textSize="20dp"
        android:gravity="center"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"

        android:orientation="vertical">



    <LinearLayout
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:layout_height="50dp">

        <TextView
            android:layout_width="150dp"
            android:layout_height="wrap_content"
            android:text="Latitude"
            android:layout_gravity="center_vertical"
            android:layout_marginLeft="10dp"
            android:textColor="#000000"
            android:textSize="20dp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text=""
            android:id="@+id/tv_latitude"
            android:layout_gravity="center_vertical"
            android:layout_marginLeft="10dp"
            android:textColor="#000000"
            android:textSize="20dp"/>


    </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:layout_height="50dp">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="Longitude"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=""
                android:id="@+id/tv_longitude"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>


        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:layout_height="50dp">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="Address"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=""
                android:id="@+id/tv_address"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>


        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:layout_height="50dp">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="Area"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=""
                android:id="@+id/tv_area"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>


        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:orientation="horizontal"
            android:layout_height="50dp">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="Locality"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text=""
                android:id="@+id/tv_locality"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="10dp"
                android:textColor="#000000"
                android:textSize="20dp"/>


        </LinearLayout>

    </LinearLayout>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/btn_start"
        android:text="Get Location"
        android:layout_alignParentBottom="true"/>



</RelativeLayout>

MainActivity.java

package servicetutorial.service;

import android.*;
import android.app.Activity;
import android.app.ActivityManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.preference.PreferenceManager;
import android.renderscript.Double2;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

public class MainActivity extends Activity {
    Button btn_start;
    private static final int REQUEST_PERMISSIONS = 100;
    boolean boolean_permission;
    TextView tv_latitude, tv_longitude, tv_address,tv_area,tv_locality;
    SharedPreferences mPref;
    SharedPreferences.Editor medit;
    Double latitude,longitude;
    Geocoder geocoder;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn_start = (Button) findViewById(R.id.btn_start);
        tv_address = (TextView) findViewById(R.id.tv_address);
        tv_latitude = (TextView) findViewById(R.id.tv_latitude);
        tv_longitude = (TextView) findViewById(R.id.tv_longitude);
        tv_area = (TextView)findViewById(R.id.tv_area);
        tv_locality = (TextView)findViewById(R.id.tv_locality);
        geocoder = new Geocoder(this, Locale.getDefault());
        mPref = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
        medit = mPref.edit();


        btn_start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (boolean_permission) {

                    if (mPref.getString("service", "").matches("")) {
                        medit.putString("service", "service").commit();

                        Intent intent = new Intent(getApplicationContext(), GoogleService.class);
                        startService(intent);

                    } else {
                        Toast.makeText(getApplicationContext(), "Service is already running", Toast.LENGTH_SHORT).show();
                    }
                } else {
                    Toast.makeText(getApplicationContext(), "Please enable the gps", Toast.LENGTH_SHORT).show();
                }

            }
        });

        fn_permission();
    }

    private void fn_permission() {
        if ((ContextCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)) {

            if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, android.Manifest.permission.ACCESS_FINE_LOCATION))) {


            } else {
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION

                        },
                        REQUEST_PERMISSIONS);

            }
        } else {
            boolean_permission = true;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);

        switch (requestCode) {
            case REQUEST_PERMISSIONS: {
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    boolean_permission = true;

                } else {
                    Toast.makeText(getApplicationContext(), "Please allow the permission", Toast.LENGTH_LONG).show();

                }
            }
        }
    }

    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {

            latitude = Double.valueOf(intent.getStringExtra("latutide"));
            longitude = Double.valueOf(intent.getStringExtra("longitude"));

            List<Address> addresses = null;

            try {
                addresses = geocoder.getFromLocation(latitude, longitude, 1);
                String cityName = addresses.get(0).getAddressLine(0);
                String stateName = addresses.get(0).getAddressLine(1);
                String countryName = addresses.get(0).getAddressLine(2);

                tv_area.setText(addresses.get(0).getAdminArea());
                tv_locality.setText(stateName);
                tv_address.setText(countryName);



            } catch (IOException e1) {
                e1.printStackTrace();
            }


            tv_latitude.setText(latitude+"");
            tv_longitude.setText(longitude+"");
            tv_address.getText();


        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(broadcastReceiver, new IntentFilter(GoogleService.str_receiver));

    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(broadcastReceiver);
    }


}

GoogleService.java

package servicetutorial.service;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.util.Log;

import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by deepshikha on 24/11/16.
 */

public class GoogleService extends Service implements LocationListener{

    boolean isGPSEnable = false;
    boolean isNetworkEnable = false;
    double latitude,longitude;
    LocationManager locationManager;
    Location location;
    private Handler mHandler = new Handler();
    private Timer mTimer = null;
    long notify_interval = 1000;
    public static String str_receiver = "servicetutorial.service.receiver";
    Intent intent;




    public GoogleService() {

    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        mTimer = new Timer();
        mTimer.schedule(new TimerTaskToGetLocation(),5,notify_interval);
        intent = new Intent(str_receiver);
//        fn_getlocation();
    }

    @Override
    public void onLocationChanged(Location location) {

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onProviderDisabled(String provider) {

    }

    private void fn_getlocation(){
        locationManager = (LocationManager)getApplicationContext().getSystemService(LOCATION_SERVICE);
        isGPSEnable = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        isNetworkEnable = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnable && !isNetworkEnable){

        }else {

            if (isNetworkEnable){
                location = null;
                locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,1000,0,this);
                if (locationManager!=null){
                    location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location!=null){

                        Log.e("latitude",location.getLatitude()+"");
                        Log.e("longitude",location.getLongitude()+"");

                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                        fn_update(location);
                    }
                }

            }


            if (isGPSEnable){
                location = null;
                locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000,0,this);
                if (locationManager!=null){
                    location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                    if (location!=null){
                        Log.e("latitude",location.getLatitude()+"");
                        Log.e("longitude",location.getLongitude()+"");
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                        fn_update(location);
                    }
                }
            }


        }

    }

    private class TimerTaskToGetLocation extends TimerTask{
        @Override
        public void run() {

            mHandler.post(new Runnable() {
                @Override
                public void run() {
                    fn_getlocation();
                }
            });

        }
    }

    private void fn_update(Location location){

        intent.putExtra("latutide",location.getLatitude()+"");
        intent.putExtra("longitude",location.getLongitude()+"");
        sendBroadcast(intent);
    }


}

Add this dependency

compile 'com.google.android.gms:play-services:9.4.0'

Having links relative to root?

Use

<a href="/fruits/index.html">Back to Fruits List</a>

or

<a href="../index.html">Back to Fruits List</a>

How to convert char* to wchar_t*?

I did something like this. The first 2 zeros are because I don't know what kind of ascii type things this command wants from me. The general feeling I had was to create a temp char array. pass in the wide char array. boom. it works. The +1 ensures that the null terminating character is in the right place. 

char tempFilePath[MAX_PATH] = "I want to convert this to wide chars";

int len = strlen(tempFilePath);

// Converts the path to wide characters
    int needed = MultiByteToWideChar(0, 0, tempFilePath, len + 1, strDestPath, len + 1);

gnuplot : plotting data from multiple input files in a single graph

You're so close!

Change

plot "print_1012720" using 1:2 title "Flow 1", \
plot "print_1058167" using 1:2 title "Flow 2", \
plot "print_193548"  using 1:2 title "Flow 3", \ 
plot "print_401125"  using 1:2 title "Flow 4", \
plot "print_401275"  using 1:2 title "Flow 5", \
plot "print_401276"  using 1:2 title "Flow 6"

to

plot "print_1012720" using 1:2 title "Flow 1", \
     "print_1058167" using 1:2 title "Flow 2", \
     "print_193548"  using 1:2 title "Flow 3", \ 
     "print_401125"  using 1:2 title "Flow 4", \
     "print_401275"  using 1:2 title "Flow 5", \
     "print_401276"  using 1:2 title "Flow 6"

The error arises because gnuplot is trying to interpret the word "plot" as the filename to plot, but you haven't assigned any strings to a variable named "plot" (which is good – that would be super confusing).

How to clear a notification in Android

All notifications (even other app notifications) can be removed via listening to 'NotificationListenerService' as mentioned in NotificationListenerService Implementation

In the service you have to call cancelAllNotifications().

The service has to be enabled for your application via:

‘Apps & notifications’ -> ‘Special app access’ -> ‘Notifications access’.

List of encodings that Node.js supports

If the above solution does not work for you it is may be possible to obtain the same result with the following pure nodejs code. The above did not work for me and resulted in a compilation exception when running 'npm install iconv' on OSX:

npm install iconv

npm WARN package.json [email protected] No README.md file found!
npm http GET https://registry.npmjs.org/iconv
npm http 200 https://registry.npmjs.org/iconv
npm http GET https://registry.npmjs.org/iconv/-/iconv-2.0.4.tgz
npm http 200 https://registry.npmjs.org/iconv/-/iconv-2.0.4.tgz

> [email protected] install /Users/markboyd/git/portal/app/node_modules/iconv
> node-gyp rebuild

gyp http GET http://nodejs.org/dist/v0.10.1/node-v0.10.1.tar.gz
gyp http 200 http://nodejs.org/dist/v0.10.1/node-v0.10.1.tar.gz
xcode-select: Error: No Xcode is selected. Use xcode-select -switch <path-to-xcode>, or see the xcode-select manpage (man xcode-select) for further information.

fs.readFileSync() returns a Buffer if no encoding is specified. And Buffer has a toString() method that will convert to UTF8 if no encoding is specified giving you the file's contents. See the nodejs documentation. This worked for me.

Xcode 6.1 - How to uninstall command line tools?

You can simply delete this folder

/Library/Developer/CommandLineTools

Please note: This is the root /Library, not user's ~/Library).

How to use a dot "." to access members of dictionary?

Derive from dict and and implement __getattr__ and __setattr__.

Or you can use Bunch which is very similar.

I don't think it's possible to monkeypatch built-in dict class.

javascript: using a condition in switch case

This works:

switch (true) {
    case liCount == 0:
        setLayoutState('start');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount<=5 && liCount>0:
        setLayoutState('upload1Row');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount<=10 && liCount>5:
        setLayoutState('upload2Rows');
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;
    case liCount>10:
        var api = $('#UploadList').data('jsp');
        api.reinitialise();
        break;                  
}

A previous version of this answer considered the parentheses to be the culprit. In truth, the parentheses are irrelevant here - the only thing necessary is switch(true){...} and for your case expressions to evaluate to booleans.

It works because, the value we give to the switch is used as the basis to compare against. Consequently, the case expressions, also evaluating to booleans will determine which case is run. Could also turn this around, and pass switch(false){..} and have the desired expressions evaluate to false instead of true.. but personally prefer dealing with conditions that evaluate to truthyness. However, it does work too, so worth keeping in mind to understand what it is doing.

Eg: if liCount is 3, the first comparison is true === (liCount == 0), meaning the first case is false. The switch then moves on to the next case true === (liCount<=5 && liCount>0). This expression evaluates to true, meaning this case is run, and terminates at the break. I've added parentheses here to make it clearer, but they are optional, depending on the complexity of your expression.

It's pretty simple, and a neat way (if it fits with what you are trying to do) of handling a long series of conditions, where perhaps a long series of ìf() ... else if() ... else if () ... might introduce a lot of visual noise or fragility.

Use with caution, because it is a non-standard pattern, despite being valid code.

python how to "negate" value : if true return false, if false return true

Use the not boolean operator:

nyval = not myval

not returns a boolean value (True or False):

>>> not 1
False
>>> not 0
True

If you must have an integer, cast it back:

nyval = int(not myval)

However, the python bool type is a subclass of int, so this may not be needed:

>>> int(not 0)
1
>>> int(not 1)
0
>>> not 0 == 1
True
>>> not 1 == 0
True

An existing connection was forcibly closed by the remote host - WCF

I had this issue start happening when debugging from one web project to a web service in the same solution. The web service was returning responses that the web project couldnt understand. It would kind of work again at some points, then stop again.

It was because there was not an explicit reference between these projects, so the web service was not getting built when hitting F5 to start debugging. Once I added that, the errors went away.

How to load assemblies in PowerShell?

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") worked for me.

Get clicked element using jQuery on event?

A simple way is to pass the data attribute to your HTML tag.

Example:

<div data-id='tagid' class="clickElem"></div>

<script>
$(document).on("click",".appDetails", function () {
   var clickedBtnID = $(this).attr('data');
   alert('you clicked on button #' + clickedBtnID);
});
</script>

How to horizontally center a floating element of a variable width?

This works better when the id = container (which is the outer div) and id = contained (which is the inner div). The problem with the highly recommended solution is that it results in some cases into an horizontal scrolling bar when the browser is trying to cater for the left: -50% attribute. There is a good reference for this solution 

        #container {
            text-align: center;
        }
        #contained {
            text-align: left;
            display: inline-block;
        }

How to kill a while loop with a keystroke?

For Python 3.7, I copied and changed the very nice answer by user297171 so it works in all scenarios in Python 3.7 that I tested.

import threading as th

keep_going = True
def key_capture_thread():
    global keep_going
    input()
    keep_going = False

def do_stuff():
    th.Thread(target=key_capture_thread, args=(), name='key_capture_thread', daemon=True).start()
    while keep_going:
        print('still going...')

do_stuff()

jQuery convert line breaks to br (nl2br equivalent)

This JavaScript function considers whether to use insert or replace to handle the swap.

(Insert or replace HTML line breaks)

/**
 * This function is same as PHP's nl2br() with default parameters.
 *
 * @param {string} str Input text
 * @param {boolean} replaceMode Use replace instead of insert
 * @param {boolean} isXhtml Use XHTML 
 * @return {string} Filtered text
 */
function nl2br (str, replaceMode, isXhtml) {

  var breakTag = (isXhtml) ? '<br />' : '<br>';
  var replaceStr = (replaceMode) ? '$1'+ breakTag : '$1'+ breakTag +'$2';
  return (str + '').replace(/([^>\r\n]?)(\r\n|\n\r|\r|\n)/g, replaceStr);
}

Demo - JSFiddle

JavaScript nl2br & br2nl functions

Getting IP address of client

As basZero mentioned, X-Forwarded-For should be checked for comma. (Look at : http://en.wikipedia.org/wiki/X-Forwarded-For). The general format of the field is: X-Forwarded-For: clientIP, proxy1, proxy2... and so on. So we will be seeing something like this : X-FORWARDED-FOR: 129.77.168.62, 129.77.63.62.

Determine if string is in list in JavaScript

Arrays have an indexOf method which can be used to search for strings:

js> a = ['foo', 'bar', 'baz']
foo,bar,baz
js> a.indexOf('bar')
1
js> a.indexOf('quux')
-1

Excel Macro : How can I get the timestamp in "yyyy-MM-dd hh:mm:ss" format?

It can work as easy as this, choose the location you want, in this case I choose D3

Sheets("Put your Sheet's name here").Range("D3") = Now

Example, my sheet is called Sources

Sheets("Sources").Range("D3") = Now

Load content of a div on another page

You just need to add a jquery selector after the url.

See: http://api.jquery.com/load/

Example straight from the API:

$('#result').load('ajax/test.html #container');

So what that does is it loads the #container element from the specified url.

Zip lists in Python

Basically the zip function works on lists, tuples and dictionaries in Python. If you are using IPython then just type zip? And check what zip() is about.

If you are not using IPython then just install it: "pip install ipython"

For lists

a = ['a', 'b', 'c']
b = ['p', 'q', 'r']
zip(a, b)

The output is [('a', 'p'), ('b', 'q'), ('c', 'r')

For dictionary:

c = {'gaurav':'waghs', 'nilesh':'kashid', 'ramesh':'sawant', 'anu':'raje'}
d = {'amit':'wagh', 'swapnil':'dalavi', 'anish':'mane', 'raghu':'rokda'}
zip(c, d)

The output is:

[('gaurav', 'amit'),
 ('nilesh', 'swapnil'),
 ('ramesh', 'anish'),
 ('anu', 'raghu')]

Add new value to an existing array in JavaScript

Indeed, you must initialize your array then right after that use array.push() command line.

var array = new Array();
array.push("first value");
array.push("second value");

How does Git handle symbolic links?

"Editor's" note: This post may contain outdated information. Please see comments and this question regarding changes in Git since 1.6.1.

Symlinked directories:

It's important to note what happens when there is a directory which is a soft link. Any Git pull with an update removes the link and makes it a normal directory. This is what I learnt hard way. Some insights here and here.

Example

Before

 ls -l
 lrwxrwxrwx 1 admin adm   29 Sep 30 15:28 src/somedir -> /mnt/somedir

git add/commit/push

It remains the same

After git pull AND some updates found

 drwxrwsr-x 2 admin adm 4096 Oct  2 05:54 src/somedir

Launch iOS simulator from Xcode and getting a black screen, followed by Xcode hanging and unable to stop tasks

I was doing what doug suggests ("Reset Content and Settings") which works but takes a lot of time and it is really annoying... until I recently found completely accidental another solution that is much quicker and seems to also work so far! Just hit cmd+L on your simulator or go to the simulator menu "Hardware -> Lock", which locks the screen, when you unlock the screen the app works like nothing ever happened :)

Javascript array declaration: new Array(), new Array(3), ['a', 'b', 'c'] create arrays that behave differently

Arrays in JS have two types of properties:

Regular elements and associative properties (which are nothing but objects)

When you define a = new Array(), you are defining an empty array. Note that there are no associative objects yet

When you define b = new Array(2), you are defining an array with two undefined locations.

In both your examples of 'a' and 'b', you are adding associative properties i.e. objects to these arrays.

console.log (a) or console.log(b) prints the array elements i.e. [] and [undefined, undefined] respectively. But since a1/a2 and b1/b2 are associative objects inside their arrays, they can be logged only by console.log(a.a1, a.a2) kind of syntax

What is a singleton in C#?

I know it's very late to answer the question but with Auto-Property you can do something like that:

public static Singleton Instance { get; } = new Singleton();

Where Singleton is you class and can be via, in this case the readonly property Instance.

specifying goal in pom.xml

The error message which you specified is nothing but you are not specifying goal for maven build.

you can specify any goal in your run configuration for maven build like clear, compile, install, package.

please following below step to resolve it.

  1. right click on your project.
  2. click 'Run as' and select 'Maven Build'
  3. edit Configuration window will open. write any goal but your problem specific write 'package' in Goal text box.
  4. click on 'Run'

Find nearest latitude/longitude with an SQL query

MS SQL Edition here:

        DECLARE @SLAT AS FLOAT
        DECLARE @SLON AS FLOAT

        SET @SLAT = 38.150785
        SET @SLON = 27.360249

        SELECT TOP 10 [LATITUDE], [LONGITUDE], SQRT(
            POWER(69.1 * ([LATITUDE] - @SLAT), 2) +
            POWER(69.1 * (@SLON - [LONGITUDE]) * COS([LATITUDE] / 57.3), 2)) AS distance
        FROM [TABLE] ORDER BY 3

WARNING in budgets, maximum exceeded for initial

Open angular.json file and find budgets keyword.

It should look like:

    "budgets": [
       {
          "type": "initial",
          "maximumWarning": "2mb",
          "maximumError": "5mb"
       }
    ]

As you’ve probably guessed you can increase the maximumWarning value to prevent this warning, i.e.:

    "budgets": [
       {
          "type": "initial",
          "maximumWarning": "4mb", <===
          "maximumError": "5mb"
       }
    ]

What does budgets mean?

A performance budget is a group of limits to certain values that affect site performance, that may not be exceeded in the design and development of any web project.

In our case budget is the limit for bundle sizes.

See also:

C# 4.0: Convert pdf to byte[] and vice versa

Easiest way:

byte[] buffer;
using (Stream stream = new IO.FileStream("file.pdf"))
{
   buffer = new byte[stream.Length - 1];
   stream.Read(buffer, 0, buffer.Length);
}

using (Stream stream = new IO.FileStream("newFile.pdf"))
{
   stream.Write(buffer, 0, buffer.Length);
}

Or something along these lines...

Allow scroll but hide scrollbar

Try this:

HTML:

<div id="container">
    <div id="content">
        // Content here
    </div>
</div>

CSS:

#container{
    height: 100%;
    width: 100%;
    overflow: hidden;
}

#content{
    width: 100%;
    height: 99%;
    overflow: auto;
    padding-right: 15px;
}

html, body{
    height: 99%;
    overflow:hidden;
}

JSFiddle Demo

Tested on FF and Safari.

Authentication plugin 'caching_sha2_password' is not supported

None of the above solution work for me. I tried and very frustrated until I watched the following video: https://www.youtube.com/watch?v=tGinfzlp0fE

pip uninstall mysql-connector work on some computer and it might not work for other computer.

I did the followings:

The mysql-connector causes problem.

  1. pip uninstall mysql-connector

    The following may not need but I removed both connector completely.

  2. pip uninstall mysql-connector-python

    re-install mysql-conenct-python connector.

  3. pip install mysql-connector-python

How can I generate an apk that can run without server with react-native?

for React Native 0.49 and over

you should go to project directory on terminal and run that command

1 - mkdir android/app/src/main/assets
2 - react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res

if under 0.49

  1 - mkdir android/app/src/main/assets
  2 - react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res

Then Use android studio to open the 'android' folder in you react native app directory, it will ask to upgrade gradle and some other stuff. go to build-> Generate signed APK and follow the instructions from there. That okey.

How to parse dates in multiple formats using SimpleDateFormat

If working in Java 1.8 you can leverage the DateTimeFormatterBuilder

public static boolean isTimeStampValid(String inputString)
{
    DateTimeFormatterBuilder dateTimeFormatterBuilder = new DateTimeFormatterBuilder()
            .append(DateTimeFormatter.ofPattern("" + "[yyyy-MM-dd'T'HH:mm:ss.SSSZ]" + "[yyyy-MM-dd]"));

    DateTimeFormatter dateTimeFormatter = dateTimeFormatterBuilder.toFormatter();

    try {
        dateTimeFormatter.parse(inputString);
        return true;
    } catch (DateTimeParseException e) {
        return false;
    }
}

See post: Java 8 Date equivalent to Joda's DateTimeFormatterBuilder with multiple parser formats?

Inserting string at position x of another string

If ES2018's lookbehind is available, one more regexp solution, that makes use of it to "replace" at a zero-width position after the Nth character (similar to @Kamil Kielczewski's, but without storing the initial characters in a capturing group):

"I want apple".replace(/(?<=^.{6})/, " an")

_x000D_
_x000D_ 
var a = "I want apple";_x000D_
var b = " an";_x000D_
var position = 6;_x000D_
_x000D_
var r= a.replace(new RegExp(`(?<=^.{${position}})`), b);_x000D_
_x000D_
console.log(r);_x000D_
console.log("I want apple".replace(/(?<=^.{6})/, " an"));
_x000D_
_x000D_
_x000D_

JavaScript: undefined !== undefined?

That's a bad practice to use the == equality operator instead of ===.

undefined === undefined // true
null == undefined // true
null === undefined // false

The object.x === undefined should return true if x is unknown property.

In chapter Bad Parts of JavaScript: The Good Parts, Crockford writes the following:

If you attempt to extract a value from an object, and if the object does not have a member with that name, it returns the undefined value instead.

In addition to undefined, JavaScript has a similar value called null. They are so similar that == thinks they are equal. That confuses some programmers into thinking that they are interchangeable, leading to code like

value = myObject[name];
if (value == null) {
    alert(name + ' not found.');
}

It is comparing the wrong value with the wrong operator. This code works because it contains two errors that cancel each other out. That is a crazy way to program. It is better written like this:

value = myObject[name];
if (value === undefined) {
    alert(name + ' not found.');
}

How do I run SSH commands on remote system using Java?

Have a look at Runtime.exec() Javadoc

Process p = Runtime.getRuntime().exec("ssh myhost");
PrintStream out = new PrintStream(p.getOutputStream());
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));

out.println("ls -l /home/me");
while (in.ready()) {
  String s = in.readLine();
  System.out.println(s);
}
out.println("exit");

p.waitFor();

Loop in react-native

First of all, I recommend writing the item you want to render multiple times (in your case list of fields) as a separate component: 

function Field() {
    return (
        <View>
            <View>
                <TextInput />
            </View>
            <View>
                <TextInput />
            </View>
            <View>
                <TextInput />
            </View>
        </View>
    );
}

Then, in your case, when rendering based on some number and not a list, I'd move the for loop outside of the render method for a more readable code: 

renderFields() {
    const noGuest = this.state.guest;
    const fields = [];
    for (let i=0; i < noGuest; i++) {
        // Try avoiding the use of index as a key, it has to be unique!
        fields.push(
            <Field key={"guest_"+i} />
        );
    }
    return fields;
}

render () {
    return (
        <View>
            <View>
                <View><Text>No</Text></View>
                <View><Text>Name</Text></View>
                <View><Text>Preference</Text></View>
            </View>
            {this.renderFields()}
        </View>;
    )
}

However, there are many more ways to render looped content in react native. Most of the ways are covered in this article, so please check it out if you're interested in more details! The examples in article are from React, but everything applies to React Native as well!

6 digits regular expression

^[0-9]{1,6}$ should do it. I don't know VB.NET good enough to know if it's the same there.

For examples, have a look at the Wikipedia.

converting a javascript string to a html object

You cannot do it with just method, unless you use some javascript framework like jquery which supports it ..

string s = '<div id="myDiv"></div>'
var htmlObject = $(s); // jquery call

but still, it would not be found by the getElementById because for that to work the element must be in the DOM... just creating in the memory does not insert it in the dom.

You would need to use append or appendTo or after etc.. to put it in the dom first..

Of'course all these can be done through regular javascript but it would take more steps to accomplish the same thing... and the logic is the same in both cases..

How do you append rows to a table using jQuery?

The following code works

<html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
function AddRow()
{
    $('#myTable').append('<tr><td>test 2</td></tr>')
}
</script>
<title></title>
</head>
<body>
<input type="button" id="btnAdd" onclick="AddRow()"/>
<a href="">test</a>
<table id="myTable">
  <tbody >
    <tr>
      <td>
        test
      </td>
    </tr>
  </tbody>
</table>
</body>
</html>

Note this will work as of jQuery 1.4 even if the table includes a <tbody> element:

jQuery since version 1.4(?) automatically detects if the element you are trying to insert (using any of the append(), prepend(), before(), or after() methods) is a <tr> and inserts it into the first <tbody> in your table or wraps it into a new <tbody> if one doesn't exist.

How to style icon color, size, and shadow of Font Awesome Icons

For Sizing Icons

Both our Web Fonts + CSS and SVG + JS frameworks include some basic controls for sizing icons in the context of your page’s UI.

you can use like

<i class="fas fa-camera fa-xs"></i>
<i class="fas fa-camera fa-sm"></i>
<i class="fas fa-camera fa-lg"></i>
<i class="fas fa-camera fa-2x"></i>
<i class="fas fa-camera fa-3x"></i>
<i class="fas fa-camera fa-5x"></i>
<i class="fas fa-camera fa-7x"></i>
<i class="fas fa-camera fa-10x"></i>

https://fontawesome.com/how-to-use/on-the-web/styling/sizing-icons

How to get the current directory in a C program?

Note that getcwd(3) is also available in Microsoft's libc: getcwd(3), and works the same way you'd expect.

Must link with -loldnames (oldnames.lib, which is done automatically in most cases), or use _getcwd(). The unprefixed version is unavailable under Windows RT.

Creating a List of Lists in C#

you should not use Nested List in List.

List<List<T>>

is not legal, even if T were a defined type.

https://msdn.microsoft.com/en-us/library/ms182144.aspx

Ruby on Rails: Clear a cached page

More esoteric ways:

Rails.cache.delete_matched("*")

For Redis:

Redis.new.keys.each{ |key| Rails.cache.delete(key) }

php date validation

I think it will help somebody.

function isValidDate($thedate) {
    $data = [
        'separators' => array("/", "-", "."),
        'date_array' => '',
        'day_index' => '',
        'year' => '',
        'month' => '',
        'day' => '',
        'status' => false
    ];

    // loop through to break down the date
    foreach ($data['separators'] as $separator) {
        $data['date_array'] = explode($separator, $thedate);
        if (count($data['date_array']) == 3) {
            $data['status'] = true;
            break;
        }
    }

    // err, if more than 4 character or not int
    if ($data['status']) {
        foreach ($data['date_array'] as $value) {
            if (strlen($value) > 4 || !is_numeric($value)) {
                $data['status'] = false;
                break;
            }
        }
    }

    // get the year
    if ($data['status']) {
        if (strlen($data['date_array'][0]) == 4) {
            $data['year'] = $data['date_array'][0];
            $data['day_index'] = 2;
        }elseif (strlen($data['date_array'][2]) == 4) {
            $data['year'] = $data['date_array'][2];
            $data['day_index'] = 0;
        }else {
            $data['status'] = false;
        }
    }

    // get the month
    if ($data['status']) {
        if (strlen($data['date_array'][1]) == 2) {
            $data['month'] = $data['date_array'][1];
        }else {
            $data['status'] = false;
        }
    }

    // get the day
    if ($data['status']) {
        if (strlen($data['date_array'][$data['day_index']]) == 2) {
            $data['day'] = $data['date_array'][$data['day_index']];
        }else {
            $data['status'] = false;
        }
    }

    // finally validate date
    if ($data['status']) {
        return checkdate($data['month'] , $data['day'], $data['year']);
    }

    return false;
}

How to get calendar Quarter from a date in TSQL

 
SELECT DATEPART(QUARTER, @date)

This returns the quarter of the @date, assuming @date is a DATETIME.

'cout' was not declared in this scope

Put the following code before int main():

using namespace std;

And you will be able to use cout.

For example:

#include<iostream>
using namespace std;
int main(){
    char t = 'f';
    char *t1;
    char **t2;
    cout<<t;        
    return 0;
}

Now take a moment and read up on what cout is and what is going on here: http://www.cplusplus.com/reference/iostream/cout/

Further, while its quick to do and it works, this is not exactly a good advice to simply add using namespace std; at the top of your code. For detailed correct approach, please read the answers to this related SO question.

What are best practices for REST nested resources?

I've tried both design strategies - nested and non-nested endpoints. I've found that:

  1. if the nested resource has a primary key and you don't have its parent primary key, the nested structure requires you to get it, even though the system doesn't actually require it.

  2. nested endpoints typically require redundant endpoints. In other words, you will more often than not, need the additional /employees endpoint so you can get a list of employees across departments. If you have /employees, what exactly does /companies/departments/employees buy you?

  3. nesting endpoints don't evolve as nicely. E.g. you might not need to search for employees now but you might later and if you have a nested structure, you have no choice but to add another endpoint. With a non-nested design, you just add more parameters, which is simpler.

  4. sometimes a resource could have multiple types of parents. Resulting in multiple endpoints all returning the same resource.

  5. redundant endpoints makes the docs harder to write and also makes the api harder to learn.

In short, the non-nested design seems to allow a more flexible and simpler endpoint schema.

Python urllib2, basic HTTP authentication, and tr.im

I would suggest that the current solution is to use my package urllib2_prior_auth which solves this pretty nicely (I work on inclusion to the standard lib.

nodejs get file name from absolute path?

 
var path = require("path");
var filepath = "C:\\Python27\\ArcGIS10.2\\python.exe";
var name = path.parse(filepath).name;
// returns
'python'

Above code returns the name of the file without extension, if you need the name with extention use

var path = require("path");
var filepath = "C:\\Python27\\ArcGIS10.2\\python.exe";
var name = path.basename(filepath);
// returns
'python.exe'

Counting lines, words, and characters within a text file using Python

 
fname = "feed.txt"
feed = open(fname, 'r')

num_lines = len(feed.splitlines())
num_words = 0
num_chars = 0

for line in lines:
    num_words += len(line.split())

How can I do time/hours arithmetic in Google Spreadsheet?

Example of calculating time:

work-start   work-stop   lunchbreak    effective time

  07:30:00    17:00:00          1.5                 8  [=((A2-A1)*24)-A3]

If you subtract one time value from another the result you get will represent the fraction of 24 hours, so if you multiply the result with 24 you get the value represented in hours.

In other words: the operation is mutiply, but the meaning is to change the format of the number (from days to hours).

What exactly is RESTful programming?

REST is the underlying architectural principle of the web. The amazing thing about the web is the fact that clients (browsers) and servers can interact in complex ways without the client knowing anything beforehand about the server and the resources it hosts. The key constraint is that the server and client must both agree on the media used, which in the case of the web is HTML.

An API that adheres to the principles of REST does not require the client to know anything about the structure of the API. Rather, the server needs to provide whatever information the client needs to interact with the service. An HTML form is an example of this: The server specifies the location of the resource and the required fields. The browser doesn't know in advance where to submit the information, and it doesn't know in advance what information to submit. Both forms of information are entirely supplied by the server. (This principle is called HATEOAS: Hypermedia As The Engine Of Application State.)

So, how does this apply to HTTP, and how can it be implemented in practice? HTTP is oriented around verbs and resources. The two verbs in mainstream usage are GET and POST, which I think everyone will recognize. However, the HTTP standard defines several others such as PUT and DELETE. These verbs are then applied to resources, according to the instructions provided by the server.

For example, Let's imagine that we have a user database that is managed by a web service. Our service uses a custom hypermedia based on JSON, for which we assign the mimetype application/json+userdb (There might also be an application/xml+userdb and application/whatever+userdb - many media types may be supported). The client and the server have both been programmed to understand this format, but they don't know anything about each other. As Roy Fielding points out:

A REST API should spend almost all of its descriptive effort in defining the media type(s) used for representing resources and driving application state, or in defining extended relation names and/or hypertext-enabled mark-up for existing standard media types.

A request for the base resource / might return something like this:

Request

GET /
Accept: application/json+userdb

Response

200 OK
Content-Type: application/json+userdb

{
    "version": "1.0",
    "links": [
        {
            "href": "/user",
            "rel": "list",
            "method": "GET"
        },
        {
            "href": "/user",
            "rel": "create",
            "method": "POST"
        }
    ]
}

We know from the description of our media that we can find information about related resources from sections called "links". This is called Hypermedia controls. In this case, we can tell from such a section that we can find a user list by making another request for /user:

Request

GET /user
Accept: application/json+userdb

Response

200 OK
Content-Type: application/json+userdb

{
    "users": [
        {
            "id": 1,
            "name": "Emil",
            "country: "Sweden",
            "links": [
                {
                    "href": "/user/1",
                    "rel": "self",
                    "method": "GET"
                },
                {
                    "href": "/user/1",
                    "rel": "edit",
                    "method": "PUT"
                },
                {
                    "href": "/user/1",
                    "rel": "delete",
                    "method": "DELETE"
                }
            ]
        },
        {
            "id": 2,
            "name": "Adam",
            "country: "Scotland",
            "links": [
                {
                    "href": "/user/2",
                    "rel": "self",
                    "method": "GET"
                },
                {
                    "href": "/user/2",
                    "rel": "edit",
                    "method": "PUT"
                },
                {
                    "href": "/user/2",
                    "rel": "delete",
                    "method": "DELETE"
                }
            ]
        }
    ],
    "links": [
        {
            "href": "/user",
            "rel": "create",
            "method": "POST"
        }
    ]
}

We can tell a lot from this response. For instance, we now know we can create a new user by POSTing to /user:

Request

POST /user
Accept: application/json+userdb
Content-Type: application/json+userdb

{
    "name": "Karl",
    "country": "Austria"
}

Response

201 Created
Content-Type: application/json+userdb

{
    "user": {
        "id": 3,
        "name": "Karl",
        "country": "Austria",
        "links": [
            {
                "href": "/user/3",
                "rel": "self",
                "method": "GET"
            },
            {
                "href": "/user/3",
                "rel": "edit",
                "method": "PUT"
            },
            {
                "href": "/user/3",
                "rel": "delete",
                "method": "DELETE"
            }
        ]
    },
    "links": {
       "href": "/user",
       "rel": "list",
       "method": "GET"
    }
}

We also know that we can change existing data:

Request

PUT /user/1
Accept: application/json+userdb
Content-Type: application/json+userdb

{
    "name": "Emil",
    "country": "Bhutan"
}

Response

200 OK
Content-Type: application/json+userdb

{
    "user": {
        "id": 1,
        "name": "Emil",
        "country": "Bhutan",
        "links": [
            {
                "href": "/user/1",
                "rel": "self",
                "method": "GET"
            },
            {
                "href": "/user/1",
                "rel": "edit",
                "method": "PUT"
            },
            {
                "href": "/user/1",
                "rel": "delete",
                "method": "DELETE"
            }
        ]
    },
    "links": {
       "href": "/user",
       "rel": "list",
       "method": "GET"
    }
}

Notice that we are using different HTTP verbs (GET, PUT, POST, DELETE etc.) to manipulate these resources, and that the only knowledge we presume on the client's part is our media definition.

Further reading:

(This answer has been the subject of a fair amount of criticism for missing the point. For the most part, that has been a fair critique. What I originally described was more in line with how REST was usually implemented a few years ago when I first wrote this, rather than its true meaning. I've revised the answer to better represent the real meaning.)

How to show alert message in mvc 4 controller?

 
Response.Write(@"<script language='javascript'>alert('Message: 
\n" + "Hi!" + " .');</script>");

Access parent DataContext from DataTemplate

the issue is that a DataTemplate isn't part of an element its applied to it.

this means if you bind to the template you're binding to something that has no context.

however if you put a element inside the template then when that element is applied to the parent it gains a context and the binding then works

so this will not work

<DataTemplate >
    <DataTemplate.Resources>
        <CollectionViewSource x:Key="projects" Source="{Binding Projects}" >

but this works perfectly

<DataTemplate >
    <GroupBox Header="Projects">
        <GroupBox.Resources>
            <CollectionViewSource x:Key="projects" Source="{Binding Projects}" >

because after the datatemplate is applied the groupbox is placed in the parent and will have access to its Context

so all you have to do is remove the style from the template and move it into an element in the template

note that the context for a itemscontrol is the item not the control ie ComboBoxItem for ComboBox not the ComboBox itself in which case you should use the controls ItemContainerStyle instead

Using Bootstrap Tooltip with AngularJS

Simple Answer - using UI Bootstrap (ui.bootstrap.tooltip)

There seem to be a bunch of very complex answers to this question. Here's what worked for me.

  1. Install UI Bootstrap - $ bower install angular-bootstrap

  2. Inject UI Bootstrap as a dependency - angular.module('myModule', ['ui.bootstrap']);

  3. Use the uib-tooltip directive in your html.

<button class="btn btn-default"
        type="button"
        uib-tooltip="I'm a tooltip!">
     I'm a button!
</button>

How do I encode/decode HTML entities in Ruby?

If you don't want to add a new dependency just to do this (like HTMLEntities) and you're already using Hpricot, it can both escape and unescape for you. It handles much more than CGI:

Hpricot.uxs "foo&nbsp;b&auml;r"
=> "foo bär"

Upload file to FTP using C#

In the first example must change those to:

requestStream.Flush();
requestStream.Close();

First flush and after that close.

TypeScript and array reduce function

It's actually the JavaScript array reduce function rather than being something specific to TypeScript.

As described in the docs: Apply a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value.

Here's an example which sums up the values of an array:

_x000D_
_x000D_ 
let total = [0, 1, 2, 3].reduce((accumulator, currentValue) => accumulator + currentValue);_x000D_
console.log(total);
_x000D_
_x000D_
_x000D_

The snippet should produce 6.

What is the iOS 5.0 user agent string?

This site seems to keep a complete list that's still maintained

iPhone, iPod Touch, and iPad from iOS 2.0 - 5.1.1 (to date).

You do need to assemble the full user-agent string out of the information listed in the page's columns.

How to play YouTube video in my Android application?

you can use this project to play any you tube video , in your android app . Now for other video , or Video id ... you can do this https://gdata.youtube.com/feeds/api/users/eminemvevo/uploads/ where eminemvevo = channel .

after finding , video id , you can put that id in cueVideo("video_id")

src -> com -> examples -> youtubeapidemo -> PlayerViewDemoActivity

  @Override
  public void onInitializationSuccess(YouTubePlayer.Provider provider, YouTubePlayer player , boolean wasRestored) {
    if (!wasRestored) {
      player.cueVideo("wKJ9KzGQq0w");
    }
  }

And specially for reading that video_id in a better way open this , and it as a xml[1st_file] file in your desktop after it create a new Xml file in your project or upload that[1st_file] saved file in your project , and right_click in it , and open it with xml_editor file , here you will find the video id of the particular video .

enter image description here

.htaccess: where is located when not in www base dir

. (dot) files are hidden by default on Unix/Linux systems. Most likely, if you know they are .htaccess files, then they are probably in the root folder for the website.

If you are using a command line (terminal) to access, then they will only show up if you use:

ls -a

If you are using a GUI application, look for a setting to "show hidden files" or something similar.

If you still have no luck, and you are on a terminal, you can execute these commands to search the whole system (may take some time):

cd /
find . -name ".htaccess"

This will list out any files it finds with that name.

SQL server ignore case in a where expression

What database are you on? With MS SQL Server, it's a database-wide setting, or you can over-ride it per-query with the COLLATE keyword.

MySQL FULL JOIN?

MySQL lacks support for FULL OUTER JOIN.

So if you want to emulate a Full join on MySQL take a look here .

A commonly suggested workaround looks like this:

SELECT  t_13.value AS val13, t_17.value AS val17
FROM    t_13
LEFT JOIN
        t_17
ON      t_13.value = t_17.value
UNION ALL
SELECT  t_13.value AS val13, t_17.value AS val17
FROM    t_13
RIGHT JOIN
        t_17
ON      t_13.value = t_17.value
WHERE   t_13.value IS NULL
ORDER BY
        COALESCE(val13, val17)
LIMIT 30

How can I add 1 day to current date?

 
int days = 1;
var newDate = new Date(Date.now() + days*24*60*60*1000);

CodePen

_x000D_
_x000D_ 
var days = 2;_x000D_
var newDate = new Date(Date.now()+days*24*60*60*1000);_x000D_
_x000D_
document.write('Today: <em>');_x000D_
document.write(new Date());_x000D_
document.write('</em><br/> New: <strong>');_x000D_
document.write(newDate);
_x000D_
_x000D_
_x000D_

How to import other Python files?

First case: You want to import file A.py in file B.py, these two files are in the same folder, like this:

. 
+-- A.py 
+-- B.py

You can do this in file B.py:

import A

or 

from A import *

or 

from A import THINGS_YOU_WANT_TO_IMPORT_IN_A

Then you will be able to use all the functions of file A.py in file B.py

Second case: You want to import file folder/A.py in file B.py, these two files are not in the same folder, like this:

.
+-- B.py
+-- folder
     +-- A.py

You can do this in file B:

import folder.A

or

from folder.A import *

or

from folder.A import THINGS_YOU_WANT_TO_IMPORT_IN_A

Then you will be able to use all the functions of file A.py in file B.py

Summary: In the first case, file A.py is a module that you imports in file B.py, you used the syntax import module_name. In the second case, folder is the package that contains the module A.py, you used the syntax import package_name.module_name.

For more info on packages and modules, consult this link.

Command not found when using sudo

You can also create a soft link to your script in one of the directories (/usr/local/bin for example) in the super user PATH. It'll then be available to the sudo.

chmod +x foo.sh
sudo ln -s path-to-foo.sh /usr/local/bin/foo

Have a look at this answer to have an idea of which directory to put soft link in.

Opening a CHM file produces: "navigation to the webpage was canceled"

Summary

Microsoft Security Updates 896358 & 840315 block display of CHM file contents when opened from a network drive (or a UNC path). This is Windows' attempt to stop attack vectors for viruses/malware from infecting your computer and has blocked out the .chm file that draw data over the "InfoTech" protocol, which this chm file uses.

Microsoft's summary of the problem: http://support.microsoft.com/kb/896054

Solutions

  1. If you are using Windows Server 2008, Windows 7, windows has created a quick fix. Right click the chm file, and you will get the "yourfile.chm Properties" dialog box, at the bottom, a button called "Unblock" appears. Click Unblock and press OK, and try to open the chm file again, it works correctly. This option is not available for earlier versions of Windows before WindowsXP (SP3).

  2. Solve the problem by moving your chm file OFF the network drive. You may be unaware you are using a network drive, double check now: Right click your .chm file, click properties and look at the "location" field. If it starts with two backslashes like this: \\epicserver\blah\, then you are using a networked drive. So to fix it, Copy the chm file, and paste it into a local drive, like C:\ or E:. Then try to reopen the chm file, windows does not freak out.

  3. Last resort, if you can't copy/move the file off the networked drive. If you must open it where it sits, and you are using a lesser version of windows like XP, Vista, ME or other, you will have to manually tell Windows not to freak out over this .chm file. HHReg (HTML Help Registration Utility) Utility Automates this Task. Basically you download the HHReg utility, load your .chm file, press OK, and it will create the necessary registry keys to tell Windows not to block it. For more info: http://www.winhelponline.com/blog/fix-cannot-view-chm-files-network-xp-2003-vista/

Windows 8 or 10? --> Upgrade to Windows XP.

How can I plot with 2 different y-axes?

If you can give up the scales/axis labels, you can rescale the data to (0, 1) interval. This works for example for different 'wiggle' trakcs on chromosomes, when you're generally interested in local correlations between the tracks and they have different scales (coverage in thousands, Fst 0-1).

# rescale numeric vector into (0, 1) interval
# clip everything outside the range 
rescale <- function(vec, lims=range(vec), clip=c(0, 1)) {
  # find the coeficients of transforming linear equation
  # that maps the lims range to (0, 1)
  slope <- (1 - 0) / (lims[2] - lims[1])
  intercept <- - slope * lims[1]

  xformed <- slope * vec + intercept

  # do the clipping
  xformed[xformed < 0] <- clip[1]
  xformed[xformed > 1] <- clip[2]

  xformed
}

Then, having a data frame with chrom, position, coverage and fst columns, you can do something like:

ggplot(d, aes(position)) + 
  geom_line(aes(y = rescale(fst))) + 
  geom_line(aes(y = rescale(coverage))) +
  facet_wrap(~chrom)

The advantage of this is that you're not limited to two trakcs.

How to automatically start a service when running a docker container?

First, there is a problem in your Dockerfile:

RUN service mysql restart && /tmp/setup.sh

Docker images do not save running processes. Therefore, your RUN command executes only during docker build phase and stops after the build is completed. Instead, you need to specify the command when the container is started using the CMD or ENTRYPOINT commands like below:

CMD mysql start

Secondly, the docker container needs a process (last command) to keep running, otherwise the container will exit/stop. Therefore, the normal service mysql start command cannot be used directly in the Dockerfile.

Solution

There are three typical ways to keep the process running:

  • Using service command and append non-end command after that like tail -F

    CMD service mysql start && tail -F /var/log/mysql/error.log

This is often preferred when you have a single service running as it makes the outputted log accessible to docker.

  • Or use foreground command to do this

    CMD /usr/bin/mysqld_safe

This works only if there is a script like mysqld_safe.

  • Or wrap your scripts into start.sh and put this in end

    CMD /start.sh

This is best if the command must perform a series of steps, again, /start.sh should stay running.

Note

For the beginner using supervisord is not recommended. Honestly, it is overkill. It is much better to use single service / single command for the container.

BTW: please check https://registry.hub.docker.com for existing mysql docker images for reference

Angular.js ng-repeat filter by property having one of multiple values (OR of values)

Best way to do this is to use a function:

<div ng-repeat="product in products | filter: myFilter">

$scope.myFilter = function (item) { 
    return item === 'red' || item === 'blue'; 
};

Alternatively, you can use ngHide or ngShow to dynamically show and hide elements based on a certain criteria.

Eclipse "Server Locations" section disabled and need to change to use Tomcat installation

Before making any changes in Tomcat Server Location, you need to remove project(s) deployed on server.

To remove project: expand tomcat server in "Servers" view
right click and select remove

Does it make sense to use Require.js with Angular.js?

Short answer is, it make sense. Recently this was discussed in ng-conf 2014. Here is the talk on this topic:

http://www.youtube.com/watch?v=4yulGISBF8w

MySQL: #126 - Incorrect key file for table

Try to run a repair command for each one of the tables involved in the query.

Use MySQL administrator, go to Catalog -> Select your Catalog -> Select a table -> Click the Maintenance button -> Repair -> Use FRM.

UITableView Cell selected Color?

 
[cell setSelectionStyle:UITableViewCellSelectionStyleGray];

Make sure you have used the above line to use the selection effect

org.postgresql.util.PSQLException: FATAL: sorry, too many clients already

We don't know what server.properties file is that, we neither know what SimocoPoolSize means (do you?)

Let's guess you are using some custom pool of database connections. Then, I guess the problem is that your pool is configured to open 100 or 120 connections, but you Postgresql server is configured to accept MaxConnections=90 . These seem conflictive settings. Try increasing MaxConnections=120.

But you should first understand your db layer infrastructure, know what pool are you using, if you really need so many open connections in the pool. And, specially, if you are gracefully returning the opened connections to the pool

Changing datagridview cell color dynamically

If you want every cell in the grid to have the same background color, you can just do this:

dataGridView1.DefaultCellStyle.BackColor = Color.Green;

Visual Studio "Could not copy" .... during build

the .vhost.exe is a debugger process, so it appears that the process being debugged hasn't closed properly. Chances are you have a bug that's keeping it alive and are not stopping the debug process correctly - there are options to detach from the process when you click 'stop debugging' instead of actually killing the debugger so maybe you have that set.

But that's the problem - the file you're trying to copy over is locked (ie still being used) by the OS so its preventing the copy. Ensure that file is free and you'll be able to copy.

Error Code 1292 - Truncated incorrect DOUBLE value - Mysql

I've seen a couple cases where this error occurs:

1. using the not equals operator != in a where clause with a list of multiple or values

such as:

where columnName !=('A'||'B')

This can be resolved by using

where columnName not in ('A','B')

2. missing a comparison operator in an if() function:

select if(col1,col1,col2);

in order to select the value in col1 if it exists and otherwise show the value in col2...this throws the error; it can be resolved by using:

select if(col1!='',col1,col2);

SQL like search string starts with

You need to use the wildcard % :

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

What is the difference between properties and attributes in HTML?

The answers already explain how attributes and properties are handled differently, but I really would like to point out how totally insane this is. Even if it is to some extent the spec.

It is crazy, to have some of the attributes (e.g. id, class, foo, bar) to retain only one kind of value in the DOM, while some attributes (e.g. checked, selected) to retain two values; that is, the value "when it was loaded" and the value of the "dynamic state". (Isn't the DOM supposed to be to represent the state of the document to its full extent?)

It is absolutely essential, that two input fields, e.g. a text and a checkbox behave the very same way. If the text input field does not retain a separate "when it was loaded" value and the "current, dynamic" value, why does the checkbox? If the checkbox does have two values for the checked attribute, why does it not have two for its class and id attributes? If you expect to change the value of a text *input* field, and you expect the DOM (i.e. the "serialized representation") to change, and reflect this change, why on earth would you not expect the same from an input field of type checkbox on the checked attribute?

The differentiation, of "it is a boolean attribute" just does not make any sense to me, or is, at least not a sufficient reason for this.

C default arguments

YES

Through macros

3 Parameters: 

#define my_func2(...) my_func3(__VA_ARGS__, 0.5)
#define my_func1(...) my_func2(__VA_ARGS__, 10)
#define VAR_FUNC(_1, _2, _3, NAME, ...) NAME
#define my_func(...) VAR_FUNC(__VA_ARGS__, my_func3, my_func2, my_func1)(__VA_ARGS__)

void my_func3(char a, int b, float c) // b=10, c=0.5
{
    printf("a=%c; b=%d; c=%f\n", a, b, c);
}

If you want 4th argument, then an extra my_func3 needs to be added. Notice the changes in VAR_FUNC, my_func2 and my_func

4 Parameters: 

#define my_func3(...) my_func4(__VA_ARGS__, "default") // <== New function added
#define my_func2(...) my_func3(__VA_ARGS__, (float)1/2)
#define my_func1(...) my_func2(__VA_ARGS__, 10)
#define VAR_FUNC(_1, _2, _3, _4, NAME, ...) NAME
#define my_func(...) VAR_FUNC(__VA_ARGS__, my_func4, my_func3, my_func2, my_func1)(__VA_ARGS__)

void my_func4(char a, int b, float c, const char* d) // b=10, c=0.5, d="default"
{
    printf("a=%c; b=%d; c=%f; d=%s\n", a, b, c, d);
}

Only exception that float variables cannot be given default values (unless if it is the last argument as in the 3 parameters case), because they need period ('.'), which is not accepted within macro arguments. But can figure out a work around as seen in my_func2 macro (of 4 parameters case)

Program

int main(void)
{
    my_func('a');
    my_func('b', 20);
    my_func('c', 200, 10.5);
    my_func('d', 2000, 100.5, "hello");

    return 0;
}

Output:

a=a; b=10; c=0.500000; d=default                                                                                                                                                  
a=b; b=20; c=0.500000; d=default                                                                                                                                                  
a=c; b=200; c=10.500000; d=default                                                                                                                                                
a=d; b=2000; c=100.500000; d=hello

Javascript Error Null is not an Object

I think the error because the elements are undefined ,so you need to add window.onload event which this event will defined your elements when the window is loaded.

window.addEventListener('load',Loaded,false);


    function Loaded(){
    var myButton = document.getElementById("myButton");
    var myTextfield = document.getElementById("myTextfield");

    function greetUser(userName) {
    var greeting = "Hello " + userName + "!";
    document.getElementsByTagName ("h2")[0].innerHTML = greeting;
    }

    myButton.onclick = function() {
    var userName = myTextfield.value;
    greetUser(userName);

    return false;
    }
    }

Android emulator not able to access the internet

closing the emulator and reopening worked for me

OS WINDOWS 10

Define constant variables in C++ header

You generally shouldn't use e.g. const int in a header file, if it's included in several source files. That is because then the variables will be defined once per source file (translation units technically speaking) because global const variables are implicitly static, taking up more memory than required.

You should instead have a special source file, Constants.cpp that actually defines the variables, and then have the variables declared as extern in the header file.

Something like this header file:

// Protect against multiple inclusions in the same source file
#ifndef CONSTANTS_H
#define CONSTANTS_H

extern const int CONSTANT_1;

#endif

And this in a source file:

const int CONSTANT_1 = 123;

How to hide a div with jQuery?

 
$('#myDiv').hide();

or

$('#myDiv').slideUp();

or

$('#myDiv').fadeOut();

How to resolve git status "Unmerged paths:"?

All you should need to do is:

# if the file in the right place isn't already committed:
git add <path to desired file>

# remove the "both deleted" file from the index:
git rm --cached ../public/images/originals/dog.ai

# commit the merge:
git commit

Reading file from Workspace in Jenkins with Groovy script

If you are trying to read a file from the workspace during a pipeline build step, there's a method for that:

readFile('name-of-file.groovy')

For reference, see https://jenkins.io/doc/pipeline/steps/workflow-basic-steps/#readfile-read-file-from-workspace.

How to increase font size in NeatBeans IDE?

1st Way:

press down Alt+z and scroll up or down (mouse wheel)

2nd way:

press down mouse scroll(wheel) button and scroll up or down

Why is jquery's .ajax() method not sending my session cookie?

I was having this same problem and doing some checks my script was just simply not getting the sessionid cookie.

I figured out by looking at the sessionid cookie value in the browser that my framework (Django) was passing the sessionid cookie with HttpOnly as default. This meant that scripts did not have access to the sessionid value and therefore were not passing it along with requests. Kind of ridiculous that HttpOnly would be the default value when so many things use Ajax which would require access restriction.

To fix this I changed a setting (SESSION_COOKIE_HTTPONLY=False) but in other cases it may be a "HttpOnly" flag on the cookie path

How to measure height, width and distance of object using camera?

If you think about it, a body XRay scan (at the medical center) too needs this kind of measurement for estimating size of tumors. So they place a 1 Dollar Coin on the body, to do a comparative measurement.

Even newspaper is printed with some marks on the corners.

You need a reference to measure. May be you can get your person to wear a cap which has a few bright green circles. Once you recognize the size of the circle you can comparatively measure the remaining.

Or you can create a transparent 1 inch circle which will superimpose on the face, move the camera toward/away the face, aim your superimposed circle on that bright green circle on the cap. Then on your photo will be as per scale.

convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

Just delete /etc/ImageMagick/policy.xml file. E.g.

rm /etc/<ImageMagick_PATH>/policy.xml

For ImageMagick 6, it's:

sudo rm /etc/ImageMagick-6/policy.xml

.NET data structures: ArrayList, List, HashTable, Dictionary, SortedList, SortedDictionary -- Speed, memory, and when to use each?

There are subtle and not-so-subtle differences between generic and non-generic collections. They merely use different underlying data structures. For example, Hashtable guarantees one-writer-many-readers without sync. Dictionary does not.

Bootstrap 3 Glyphicons are not working

This was the reason, why the icons didn't show up for me:

* {
    arial, sans-serif !important;
}

After i have removed this part of my CSS, everything worked like it should. The !important was the one causing trouble.

how to check confirm password field in form without reloading page

 
$box = $('input[name=showPassword]');

$box.focus(function(){
    if ($(this).is(':checked')) {
        $('input[name=pswd]').attr('type', 'password');    
    } else {
        $('input[name=pswd]').attr('type', 'text');
    }
})

Unique Key constraints for multiple columns in Entity Framework

Recently added a composite key with the uniqueness of 2 columns using the approach that 'chuck' recommended, thank @chuck. Only this approached looked cleaner to me:

public int groupId {get; set;}

[Index("IX_ClientGrouping", 1, IsUnique = true)]
public int ClientId { get; set; }

[Index("IX_ClientGrouping", 2, IsUnique = true)]
public int GroupName { get; set; }

Java - How to convert type collection into ArrayList?

Try this code

Convert ArrayList to Collection

  ArrayList<User> usersArrayList = new ArrayList<User>();

  Collection<User> userCollection = new HashSet<User>(usersArrayList);

Convert Collection to ArrayList

  Collection<User> userCollection = new HashSet<User>(usersArrayList);

  List<User> userList = new ArrayList<User>(userCollection );

no module named zlib

The easiest solution I found, is given on python.org devguide:

sudo apt-get build-dep python3.6

If that package is not available for your system, try reducing the minor version until you find a package that is available in your system’s package manager.

I tried explaining details, on my blog.

How to increase an array's length

By definition arrays are fixed size. You can use instead an Arraylist wich is that, a "dynamic size" array. Actually what happens is that the VM "adjust the size"* of the array exposed by the ArrayList.

See also

*using back-copy arrays

SQL to search objects, including stored procedures, in Oracle

In Oracle 11g, if you want to search any text in whole database or procedure below mentioned query can be used:

select * from user_source WHERE UPPER(text) LIKE '%YOUR SAGE%'

Add "Are you sure?" to my excel button, how can I?

On your existing button code, simply insert this line before the procedure:

If MsgBox("This will erase everything! Are you sure?", vbYesNo) = vbNo Then Exit Sub

This will force it to quit if the user presses no.

How to convert current date into string in java?

 
// GET DATE & TIME IN ANY FORMAT
import java.util.Calendar;
import java.text.SimpleDateFormat;
public static final String DATE_FORMAT_NOW = "yyyy-MM-dd HH:mm:ss";

public static String now() {
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_NOW);
return sdf.format(cal.getTime());
}

Taken from here

Nginx: Job for nginx.service failed because the control process exited

Just write this your work get done

sudo rm /etc/nginx/sites-enabled/default

sudo service nginx restart

systemctl status nginx

Happy Learning

How to get annotations of a member variable?

My way

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;

public class ReadAnnotation {
    private static final Logger LOGGER = LoggerFactory.getLogger(ReadAnnotation.class);

    public static boolean hasIgnoreAnnotation(String fieldName, Class entity) throws NoSuchFieldException {
        return entity.getDeclaredField(fieldName).isAnnotationPresent(IgnoreAnnotation.class);
    }

    public static boolean isSkip(PropertyDescriptor propertyDescriptor, Class entity) {
        boolean isIgnoreField;
        try {
            isIgnoreField = hasIgnoreAnnotation(propertyDescriptor.getName(), entity);
        } catch (NoSuchFieldException e) {
            LOGGER.error("Can not check IgnoreAnnotation", e);
            isIgnoreField = true;
        }
        return isIgnoreField;
    }

    public void testIsSkip() throws Exception {
        Class<TestClass> entity = TestClass.class;
        BeanInfo beanInfo = Introspector.getBeanInfo(entity);

        for (PropertyDescriptor propertyDescriptor : beanInfo.getPropertyDescriptors()) {
            System.out.printf("Field %s, has annotation %b", propertyDescriptor.getName(),  isSkip(propertyDescriptor, entity));
        }
    }

}

What is WebKit and how is it related to CSS?

Addition to what @KennyTM said:

  • IE
  • Edge
  • Firefox
    • Engine: Gecko
    • CSS-prefix: -moz
  • Opera
    • Engine: Presto ? Blink1
    • CSS-prefix: -o (Presto) and -webkit (Blink)
  • Safari
    • Engine: WebKit
    • CSS-prefix: -webkit
  • Chrome

1) On February 12 2013 Opera (version 15+) announces they moving away from their own engine Presto to WebKit named Blink.

2) On April 3 2013 Google (Chrome version 28+) announces they are going to use the WebKit-based Blink engine.

3) On December 6 2018 Microsoft (Microsoft Edge 79+ stable) announces they are going to use the WebKit-based Blink engine.

How can I clone a private GitLab repository?

You might need a ~/.ssh/config:

Host gitlab.YOURDOMAIN.DOMAIN
    Port 1111
    IdentityFile ~/.ssh/id_rsa

and then you can use git clone git@DOMAINandREPOSITORY. This means you always use the user git.

What does the 'Z' mean in Unix timestamp '120314170138Z'?

The Z stands for 'Zulu' - your times are in UTC. From Wikipedia:

The UTC time zone is sometimes denoted by the letter Z—a reference to the equivalent nautical time zone (GMT), which has been denoted by a Z since about 1950. The letter also refers to the "zone description" of zero hours, which has been used since 1920 (see time zone history). Since the NATO phonetic alphabet and amateur radio word for Z is "Zulu", UTC is sometimes known as Zulu time. This is especially true in aviation, where Zulu is the universal standard.

Difference between & and && in Java?

&& == logical AND

& = bitwise AND

How does the "position: sticky;" property work?

Using the strategy from this blog (https://www.designcise.com/web/tutorial/how-to-fix-issues-with-css-position-sticky-not-working) I came up with an option for those that can't have control over all components in the page

I'm using Angular and in the ngOnInit method I run this code to change the visible propertys of parents to visible

/**
 * position: sticky
 * only works if all parent components are visibile
 */
let parent = document.querySelector('.sticky').parentElement;
while (parent) {
  const hasOverflow = getComputedStyle(parent).overflow;
  if (hasOverflow !== 'visible') {
    parent.style.overflow = 'visible';
    // console.log(hasOverflow, parent);
  }
  parent = parent.parentElement;
}

CSS to set A4 paper size

I looked into this a bit more and the actual problem seems to be with assigning initial to page width under the print media rule. It seems like in Chrome width: initial on the .page element results in scaling of the page content if no specific length value is defined for width on any of the parent elements (width: initial in this case resolves to width: auto ... but actually any value smaller than the size defined under the @page rule causes the same issue).

So not only the content is now too long for the page (by about 2cm), but also the page padding will be slightly more than the initial 2cm and so on (it seems to render the contents under width: auto to the width of ~196mm and then scale the whole content up to the width of 210mm ~ but strangely exactly the same scaling factor is applied to contents with any width smaller than 210mm).

To fix this problem you can simply in the print media rule assign the A4 paper width and hight to html, body or directly to .page and in this case avoid the initial keyword.

DEMO

@page {
  size: A4;
  margin: 0;
}
@media print {
  html, body {
    width: 210mm;
    height: 297mm;
  }
  /* ... the rest of the rules ... */
}

This seems to keep everything else the way it is in your original CSS and fix the problem in Chrome (tested in different versions of Chrome under Windows, OS X and Ubuntu).

How to run a PowerShell script without displaying a window?

I got really tired of going through answers only to find it did not work as expected.

Solution

Make a vbs script to run a hidden batch file which launches the powershell script. Seems silly to make 3 files for this task but atleast the total size is less than 2KB and it runs perfect from tasker or manually (you dont see anything).

scriptName.vbs

Set WinScriptHost = CreateObject("WScript.Shell")
WinScriptHost.Run Chr(34) & "C:\Users\leathan\Documents\scriptName.bat" & Chr(34), 0
Set WinScriptHost = Nothing

scriptName.bat

powershell.exe -ExecutionPolicy Bypass C:\Users\leathan\Documents\scriptName.ps1

scriptName.ps1

Your magical code here.

Autonumber value of last inserted row - MS Access / VBA

Both of the examples immediately above didn't work for me. Opening a recordset on the table and adding a record does work to add the record, except:

myLong = CLng(rs!AutoNumberField)

returns Null if put between rs.AddNew and rs.Update. If put after rs.Update, it does return something, but it's always wrong, and always the same incorrect value. Looking at the table directly after adding the new record shows an autonumber field value different than the one returned by the above statement.

myLong = DLookup("AutoNumberField","TableName","SomeCriteria")

will work properly, as long as it's done after rs.Update, and there are any other fields which can uniquely identify the record.

How to delete history of last 10 commands in shell?

With Bash 5 you can now do a range...Hooray!:

history -d 511-520

or counting backwards 10:

history -d -10--1

Excerpt from Bash 5 Man Page:

'history'

Options, if supplied, have the following meanings:

'-d OFFSET' Delete the history entry at position OFFSET. If OFFSET is positive, it should be specified as it appears when the history is displayed. If OFFSET is negative, it is interpreted as relative to one greater than the last history position, so negative indices count back from the end of the history, and an index of '-1' refers to the current 'history -d' command.

'-d START-END' Delete the history entries between positions START and END, inclusive. Positive and negative values for START and END are interpreted as described above.

Here is my solution for Bash 4. It iteratively deletes a single entry or a range of history starting with lowest index.

delHistory () {
    count=$(( ${2:-$1} - $1 ))
    while [[ $count -ge 0 ]]; do
        history -d "$1"
        ((count--))
    done
}

delHistory 511 520

RegEx to parse or validate Base64 data

Neither a ":" nor a "." will show up in valid Base64, so I think you can unambiguously throw away the http://www.stackoverflow.com line. In Perl, say, something like

my $sanitized_str = join q{}, grep {!/[^A-Za-z0-9+\/=]/} split /\n/, $str;

say decode_base64($sanitized_str);

might be what you want. It produces

This is simple ASCII Base64 for StackOverflow exmaple.

Redirect using AngularJS

It is hard to say without knowing your code. My best guess is that the onchange event is not firing when you change your textbox value from JavaScript code.

There are two ways for this to work; the first is to call onchange by yourself, and the second is to wait for the textbox to lose focus.

Check this question; same issue, different framework.

Returning JSON response from Servlet to Javascript/JSP page

I think that what you want to do is turn the JSON string back into an object when it arrives back in your XMLHttpRequest - correct?

If so, you need to eval the string to turn it into a JavaScript object - note that this can be unsafe as you're trusting that the JSON string isn't malicious and therefore executing it. Preferably you could use jQuery's parseJSON

Get file from project folder java

Well, there are many different ways to get a file in Java, but that's the general gist.

Don't forget that you'll need to wrap that up inside a try {} catch (Exception e){} at the very least, because File is part of java.io which means it must have try-catch block.

Not to step on Ericson's question, but if you are using actual packages, you'll have issues with locations of files, unless you explicitly use it's location. Relative pathing gets messed up with Packages.

ie,

src/
    main.java
    x.txt

In this example, using File f = new File("x.txt"); inside of main.java will throw a file-not-found exception.

However, using File f = new File("src/x.txt"); will work.

Hope that helps!

Bootstrap 4 Dropdown Menu not working?

Add this code to your jquery 

  $('.dropdown').click(function(){

       $('.dropdown-menu').toggleClass('show');

   });

Solving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException

Most of the other answers point to eager loading, but I found another solution.

In my case I had an EF object InventoryItem with a collection of InvActivity child objects. 

class InventoryItem {
...
   // EF code first declaration of a cross table relationship
   public virtual List<InvActivity> ItemsActivity { get; set; }

   public GetLatestActivity()
   {
       return ItemActivity?.OrderByDescending(x => x.DateEntered).SingleOrDefault();
   }
...
}

And since I was pulling from the child object collection instead of a context query (with IQueryable), the Include() function was not available to implement eager loading. So instead my solution was to create a context from where I utilized GetLatestActivity() and attach() the returned object:

using (DBContext ctx = new DBContext())
{
    var latestAct = _item.GetLatestActivity();

    // attach the Entity object back to a usable database context
    ctx.InventoryActivity.Attach(latestAct);

    // your code that would make use of the latestAct's lazy loading
    // ie   latestAct.lazyLoadedChild.name = "foo";
}

Thus you aren't stuck with eager loading.

How do I align a label and a textarea?

Use vertical-align:middle in your CSS.

<table>
    <tr>
       <td style="vertical-align:middle">Description:</td>
       <td><textarea></textarea></td>
    </tr>
</table>

How do I manage conflicts with git submodules?

Well, its not technically managing conflicts with submodules (ie: keep this but not that), but I found a way to continue working...and all I had to do was pay attention to my git status output and reset the submodules:

git reset HEAD subby
git commit

That would reset the submodule to the pre-pull commit. Which in this case is exactly what I wanted. And in other cases where I need the changes applied to the submodule, I'll handle those with the standard submodule workflows (checkout master, pull down the desired tag, etc).

Servlet returns "HTTP Status 404 The requested resource (/servlet) is not available"

Solution for HTTP Status 404 in NetBeans IDE: Right click on your project and go to your project properties, then click on run, then input your project relative URL like index.jsp.

  1. Project->Properties
  2. Click on Run
  3. Relative URL:/index.jsp (Select your project root URL)

enter image description here

Pythonic way to check if a list is sorted or not

How about this one ? Simple and straightforward. 

def is_list_sorted(al):

    llength =len(al)


    for i in range (llength):
        if (al[i-1] > al[i]):
            print(al[i])
            print(al[i+1])
            print('Not sorted')
            return -1

    else :
        print('sorted')
        return  true

How to have stored properties in Swift, the same way I had on Objective-C?

I found this solution more practical

UPDATED for Swift 3

extension UIColor {

    static let graySpace = UIColor.init(red: 50/255, green: 50/255, blue: 50/255, alpha: 1.0)
    static let redBlood = UIColor.init(red: 102/255, green: 0/255, blue: 0/255, alpha: 1.0)
    static let redOrange = UIColor.init(red: 204/255, green: 17/255, blue: 0/255, alpha: 1.0)

    func alpha(value : CGFloat) -> UIColor {
        var r = CGFloat(0), g = CGFloat(0), b = CGFloat(0), a = CGFloat(0)
        self.getRed(&r, green: &g, blue: &b, alpha: &a)
        return UIColor(red: r, green: g, blue: b, alpha: value)
    }

}

...then in your code

class gameController: UIViewController {

    @IBOutlet var game: gameClass!

    override func viewDidLoad() {
        self.view.backgroundColor = UIColor.graySpace

    }
}

CS1617: Invalid option ‘6’ for /langversion; must be ISO-1, ISO-2, 3, 4, 5 or Default

If above all options are not working and you have used nuget packages like Microsoft.Net.Compilers and CodeDom and still not working then there is issue with your project file open project file. Project file is using one of the compiler option which not support your selected language. Open project file with notepad++ and remove the following line.

Orignal Project File

<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props" Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props')" />
  <!--Don't delete below one-->
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />

Remove The following lines

  <Import Project="..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.Toolset.3.7.0\build\Microsoft.Net.Compilers.Toolset.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.3.7.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.1.0.0\build\Microsoft.Net.Compilers.props')" />
  <Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props" Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\TypeScript\Microsoft.TypeScript.Default.props')" />

jQuery selector for inputs with square brackets in the name attribute

The attribute selector syntax is [name=value] where name is the attribute name and value is the attribute value.

So if you want to select all input elements with the attribute name having the value inputName[]:

$('input[name="inputName[]"]')

And if you want to check for two attributes (here: name and value):

$('input[name="inputName[]"][value=someValue]')

How to provide animation when calling another activity in Android?

You must use OverridePendingTransition method to achieve it, which is in the Activity class. Sample Animations in the apidemos example's res/anim folder. Check it. More than check the demo in ApiDemos/App/Activity/animation.

Example:

@Override
public void onResume(){
    // TODO LC: preliminary support for views transitions
    this.overridePendingTransition(R.anim.in_from_right, R.anim.out_to_left);
}

addID in jQuery?

do you mean a method?

$('div.foo').attr('id', 'foo123');

Just be careful that you don't set multiple elements to the same ID.

Log.INFO vs. Log.DEBUG

I usually try to use it like this:

  • DEBUG: Information interesting for Developers, when trying to debug a problem.
  • INFO: Information interesting for Support staff trying to figure out the context of a given error
  • WARN to FATAL: Problems and Errors depending on level of damage.

How to redirect the output of an application in background to /dev/null

These will also redirect both:

yourcommand  &> /dev/null

yourcommand  >& /dev/null

though the bash manual says the first is preferred.

How to ensure a <select> form field is submitted when it is disabled?

The easiest way i found was to create a tiny javascript function tied to your form :

function enablePath() {
    document.getElementById('select_name').disabled= "";
}

and you call it in your form here : 

<form action="act.php" method="POST" name="form_name" onSubmit="enablePath();">

Or you can call it in the function you use to check your form :)

View markdown files offline

Check out Haroopad. This is a really nice #markdown editor. It is free and available for multiple platforms. I've tried it on Mac OSX.

Install IPA with iTunes 11

For iTunes 11:

  1. open your iTunes "Side Bar" by going to View -> Show Side Bar
  2. drag the mobileprovision and ipa files to your iTunes "Apps" under LIBRARY
  3. open you device Apps from DEVICES and click install for the application and wait for iTunes to sync

Is it a good practice to use an empty URL for a HTML form's action attribute? (action="")

I normally use action="", which is XHTML valid and retains the GET data in the URL.

How to assign bean's property an Enum value in Spring config file?

To be specific, set the value to be the name of a constant of the enum type, e.g., "TYPE1" or "TYPE2" in your case, as shown below. And it will work:

<bean name="someName" class="my.pkg.classes">
   <property name="type" value="TYPE1" />
</bean>

Cannot implicitly convert type 'int?' to 'int'.

Well you're casting OrdersPerHour to an int?

OrdersPerHour = (int?)dbcommand.ExecuteScalar();

Yet your method signature is int:

static int OrdersPerHour(string User)

The two have to match.

Also a quick suggestion -> Use parameters in your query, something like:

string query = "SELECT COUNT(ControlNumber) FROM Log WHERE DateChanged > ? AND User = ? AND Log.EndStatus in ('Needs Review', 'Check Search', 'Vision Delivery', 'CA Review', '1TSI To Be Delivered')";
OleDbCommand dbcommand = new OleDbCommand(query, conn);
dbcommand.Parameters.Add(curTime.AddHours(-1));
dbcommand.Parameters.Add(User);

auto run a bat script in windows 7 at login

Just enable parsing of the autoexec.bat in the registry, using these instructions.

:: works only on windows vista and earlier 
Run REGEDT32.EXE.
Modify the following value within HKEY_CURRENT_USER: 

Software\Microsoft\Windows NT\CurrentVersion\Winlogon\ParseAutoexec 

1 = autoexec.bat is parsed
0 = autoexec.bat is not parsed

Dynamic LINQ OrderBy on IEnumerable<T> / IQueryable<T>

Just building on what others have said. I found that the following works quite well.

public static IEnumerable<T> OrderBy<T>(this IEnumerable<T> input, string queryString)
{
    if (string.IsNullOrEmpty(queryString))
        return input;

    int i = 0;
    foreach (string propname in queryString.Split(','))
    {
        var subContent = propname.Split('|');
        if (Convert.ToInt32(subContent[1].Trim()) == 0)
        {
            if (i == 0)
                input = input.OrderBy(x => GetPropertyValue(x, subContent[0].Trim()));
            else
                input = ((IOrderedEnumerable<T>)input).ThenBy(x => GetPropertyValue(x, subContent[0].Trim()));
        }
        else
        {
            if (i == 0)
                input = input.OrderByDescending(x => GetPropertyValue(x, subContent[0].Trim()));
            else
                input = ((IOrderedEnumerable<T>)input).ThenByDescending(x => GetPropertyValue(x, subContent[0].Trim()));
        }
        i++;
    }

    return input;
}

jQuery get the rendered height of an element?

Sometimes offsetHeight will return zero because the element you've created has not been rendered in the Dom yet. I wrote this function for such circumstances:

function getHeight(element)
{
    var e = element.cloneNode(true);
    e.style.visibility = "hidden";
    document.body.appendChild(e);
    var height = e.offsetHeight + 0;
    document.body.removeChild(e);
    e.style.visibility = "visible";
    return height;
}

How to fix Error: "Could not find schema information for the attribute/element" by creating schema

UPDATE Sept 2015
This answer continues to get upvotes, so I'm going to leave it here since it seems to be helpful to some people, but please check out the other answers from @reexmonkey and @Pressacco first. They may provide better results.

ORIGINAL ANSWER
Give this a shot:

  1. In Visual Studio, open your app.config or web.config file.
  2. Go to the "XML" menu and select "Create Schema". This action should create a new file called "app.xsd" or "web.xsd".
  3. Save that file to your disk.
  4. Go back to your app.config or web.config and in the edit window, right click and select properties. From there, make sure the xsd you just generated is referenced in the Schemas property. If it's not there then add it.

That should cause those messages to disappear.

I saved my web.xsd in the root of my web folder (which might not be the best place for it, but just for demonstration purposes) and my Schemas property looks like this:

"C:\Program Files (x86)\Microsoft Visual Studio 10.0\xml\Schemas\DotNetConfig.xsd" "Web.xsd"

Maximum packet size for a TCP connection

At the application level, the application uses TCP as a stream oriented protocol. TCP in turn has segments and abstracts away the details of working with unreliable IP packets.

TCP deals with segments instead of packets. Each TCP segment has a sequence number which is contained inside a TCP header. The actual data sent in a TCP segment is variable.

There is a value for getsockopt that is supported on some OS that you can use called TCP_MAXSEG which retrieves the maximum TCP segment size (MSS). It is not supported on all OS though.

I'm not sure exactly what you're trying to do but if you want to reduce the buffer size that's used you could also look into: SO_SNDBUF and SO_RCVBUF.

Learning Regular Expressions

The most important part is the concepts. Once you understand how the building blocks work, differences in syntax amount to little more than mild dialects. A layer on top of your regular expression engine's syntax is the syntax of the programming language you're using. Languages such as Perl remove most of this complication, but you'll have to keep in mind other considerations if you're using regular expressions in a C program.

If you think of regular expressions as building blocks that you can mix and match as you please, it helps you learn how to write and debug your own patterns but also how to understand patterns written by others.

Start simple

Conceptually, the simplest regular expressions are literal characters. The pattern N matches the character 'N'.

Regular expressions next to each other match sequences. For example, the pattern Nick matches the sequence 'N' followed by 'i' followed by 'c' followed by 'k'.

If you've ever used grep on Unix—even if only to search for ordinary looking strings—you've already been using regular expressions! (The re in grep refers to regular expressions.)

Order from the menu

Adding just a little complexity, you can match either 'Nick' or 'nick' with the pattern [Nn]ick. The part in square brackets is a character class, which means it matches exactly one of the enclosed characters. You can also use ranges in character classes, so [a-c] matches either 'a' or 'b' or 'c'.

The pattern . is special: rather than matching a literal dot only, it matches any character†. It's the same conceptually as the really big character class [-.?+%$A-Za-z0-9...].

Think of character classes as menus: pick just one.

Helpful shortcuts

Using . can save you lots of typing, and there are other shortcuts for common patterns. Say you want to match a digit: one way to write that is [0-9]. Digits are a frequent match target, so you could instead use the shortcut \d. Others are \s (whitespace) and \w (word characters: alphanumerics or underscore).

The uppercased variants are their complements, so \S matches any non-whitespace character, for example.

Once is not enough

From there, you can repeat parts of your pattern with quantifiers. For example, the pattern ab?c matches 'abc' or 'ac' because the ? quantifier makes the subpattern it modifies optional. Other quantifiers are

  • * (zero or more times)
  • + (one or more times)
  • {n} (exactly n times)
  • {n,} (at least n times)
  • {n,m} (at least n times but no more than m times)

Putting some of these blocks together, the pattern [Nn]*ick matches all of

  • ick
  • Nick
  • nick
  • Nnick
  • nNick
  • nnick
  • (and so on)

The first match demonstrates an important lesson: * always succeeds! Any pattern can match zero times.

A few other useful examples:

  • [0-9]+ (and its equivalent \d+) matches any non-negative integer
  • \d{4}-\d{2}-\d{2} matches dates formatted like 2019-01-01

Grouping

A quantifier modifies the pattern to its immediate left. You might expect 0abc+0 to match '0abc0', '0abcabc0', and so forth, but the pattern immediately to the left of the plus quantifier is c. This means 0abc+0 matches '0abc0', '0abcc0', '0abccc0', and so on.

To match one or more sequences of 'abc' with zeros on the ends, use 0(abc)+0. The parentheses denote a subpattern that can be quantified as a unit. It's also common for regular expression engines to save or "capture" the portion of the input text that matches a parenthesized group. Extracting bits this way is much more flexible and less error-prone than counting indices and substr.

Alternation

Earlier, we saw one way to match either 'Nick' or 'nick'. Another is with alternation as in Nick|nick. Remember that alternation includes everything to its left and everything to its right. Use grouping parentheses to limit the scope of |, e.g., (Nick|nick).

For another example, you could equivalently write [a-c] as a|b|c, but this is likely to be suboptimal because many implementations assume alternatives will have lengths greater than 1.

Escaping

Although some characters match themselves, others have special meanings. The pattern \d+ doesn't match backslash followed by lowercase D followed by a plus sign: to get that, we'd use \\d\+. A backslash removes the special meaning from the following character.

Greediness

Regular expression quantifiers are greedy. This means they match as much text as they possibly can while allowing the entire pattern to match successfully.

For example, say the input is

"Hello," she said, "How are you?"

You might expect ".+" to match only 'Hello,' and will then be surprised when you see that it matched from 'Hello' all the way through 'you?'.

To switch from greedy to what you might think of as cautious, add an extra ? to the quantifier. Now you understand how \((.+?)\), the example from your question works. It matches the sequence of a literal left-parenthesis, followed by one or more characters, and terminated by a right-parenthesis.

If your input is '(123) (456)', then the first capture will be '123'. Non-greedy quantifiers want to allow the rest of the pattern to start matching as soon as possible.

(As to your confusion, I don't know of any regular-expression dialect where ((.+?)) would do the same thing. I suspect something got lost in transmission somewhere along the way.)

Anchors

Use the special pattern ^ to match only at the beginning of your input and $ to match only at the end. Making "bookends" with your patterns where you say, "I know what's at the front and back, but give me everything between" is a useful technique.

Say you want to match comments of the form

-- This is a comment --

you'd write ^--\s+(.+)\s+--$.

Build your own

Regular expressions are recursive, so now that you understand these basic rules, you can combine them however you like.

Tools for writing and debugging regexes:

Books

Free resources

Footnote

†: The statement above that . matches any character is a simplification for pedagogical purposes that is not strictly true. Dot matches any character except newline, "\n", but in practice you rarely expect a pattern such as .+ to cross a newline boundary. Perl regexes have a /s switch and Java Pattern.DOTALL, for example, to make . match any character at all. For languages that don't have such a feature, you can use something like [\s\S] to match "any whitespace or any non-whitespace", in other words anything.

Moving Panel in Visual Studio Code to right side

I'm using Visual Studio Code v1.24.0 on a Mac.

By default, the Panel will appear on the bottom (You can change the default as well. Please refer to @Forres' answer: Moving Panel in Visual Studio Code to right side)

Here's the bottom/right toggle button for VS Code Panel:

enter image description here

Once I click on this button, the Panel moves to the right.

enter image description here

Moving it back is a little tricky though. As you can see, some of the buttons are hidden. This is because the width of the panel when it's aligned right is too small. We need to expand the column to see all the buttons.

This is how it'll look upon expansion:

enter image description here

Now, if you want to move the Panel back to the bottom, click on the toggle bottom/top button again.

How to resize an image to a specific size in OpenCV?

Make a useful function like this:

IplImage* img_resize(IplImage* src_img, int new_width,int new_height)
{
    IplImage* des_img;
    des_img=cvCreateImage(cvSize(new_width,new_height),src_img->depth,src_img->nChannels);
    cvResize(src_img,des_img,CV_INTER_LINEAR);
    return des_img;
}

Char array in a struct - incompatible assignment?

You can use strcpy to populate it. You can also initialize it from another struct.

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

struct name {
    char first[20];
    char last[20];
};

int main() {
    struct name sara;
    struct name other;

    strcpy(sara.first,"Sara");
    strcpy(sara.last, "Black");

    other = sara;

    printf("struct: %s\t%s\n", sara.first, sara.last);
    printf("other struct: %s\t%s\n", other.first, other.last);

}

How can I pass request headers with jQuery's getJSON() method?

I agree with sunetos that you'll have to use the $.ajax function in order to pass request headers. In order to do that, you'll have to write a function for the beforeSend event handler, which is one of the $.ajax() options. Here's a quick sample on how to do that:

<html>
  <head>
    <script src="http://code.jquery.com/jquery-1.4.2.min.js"></script>
    <script type="text/javascript">
      $(document).ready(function() {
        $.ajax({
          url: 'service.svc/Request',
          type: 'GET',
          dataType: 'json',
          success: function() { alert('hello!'); },
          error: function() { alert('boo!'); },
          beforeSend: setHeader
        });
      });

      function setHeader(xhr) {
        xhr.setRequestHeader('securityCode', 'Foo');
        xhr.setRequestHeader('passkey', 'Bar');
      }
    </script>
  </head>
  <body>
    <h1>Some Text</h1>
  </body>
</html>

If you run the code above and watch the traffic in a tool like Fiddler, you'll see two requests headers passed in:

  • securityCode with a value of Foo
  • passkey with a value of Bar

The setHeader function could also be inline in the $.ajax options, but I wanted to call it out.

Hope this helps!

How can I append a string to an existing field in MySQL?

Update image field to add full URL, ignoring null fields:

UPDATE test SET image = CONCAT('https://my-site.com/images/',image) WHERE image IS NOT NULL;

What is REST? Slightly confused

REST is a software design pattern typically used for web applications. In layman's terms this means that it is a commonly used idea used in many different projects. It stands for REpresentational State Transfer. The basic idea of REST is treating objects on the server-side (as in rows in a database table) as resources than can be created or destroyed.

The most basic way of thinking about REST is as a way of formatting the URLs of your web applications. For example, if your resource was called "posts", then:

/posts Would be how a user would access ALL the posts, for displaying.

/posts/:id Would be how a user would access and view an individual post, retrieved based on their unique id.

/posts/new Would be how you would display a form for creating a new post.

Sending a POST request to /users would be how you would actually create a new post on the database level.

Sending a PUT request to /users/:id would be how you would update the attributes of a given post, again identified by a unique id.

Sending a DELETE request to /users/:id would be how you would delete a given post, again identified by a unique id.

As I understand it, the REST pattern was mainly popularized (for web apps) by the Ruby on Rails framework, which puts a big emphasis on RESTful routes. I could be wrong about that though.

I may not be the most qualified to talk about it, but this is how I've learned it (specifically for Rails development).

When someone refers to a "REST api," generally what they mean is an api that uses RESTful urls for retrieving data.

SSL Proxy/Charles and Android trouble

Edit - this answer was for an earlier version of Charles. See @semicircle21 answer below for the proper steps for v3.10.x -- much easier than this approach too... :-)

For what it's worth here are the step by step instructions for this. They should apply equally well in iOS too:

  1. Open Charles
  2. Go to Proxy > Proxy Settings > SSL
  3. Check “Enable SSL Proxying”
  4. Select “Add location” and enter the host name and port (if needed)
  5. Click ok and make sure the option is checked
  6. Download the Charles cert from here: Charles cert >
  7. Send that file to yourself in an email.
  8. Open the email on your device and select the cert
  9. In “Name the certificate” enter whatever you want
  10. Click OK and you should get a message that the certificate was installed

You should then be able to see the SSL files in Charles. If you want to intercept and change the values you can use the "Map Local" tool which is really awesome:

  1. In Charles go to Tools > Map Local
  2. Select "Add entry"
  3. Enter the values for the file you want to replace
  4. In “Local path” select the file you want the app to load instead
  5. Click OK
  6. Make sure the entry is selected and click OK
  7. Run your app
  8. You should see in “Notes” that your file loads instead of the live one

How to compile or convert sass / scss to css with node-sass (no Ruby)?

I picked node-sass implementer for libsass because it is based on node.js.

Installing node-sass

  • (Prerequisite) If you don't have npm, install Node.js first.
  • $ npm install -g node-sass installs node-sass globally -g.

This will hopefully install all you need, if not read libsass at the bottom.

How to use node-sass from Command line and npm scripts

General format:

$ node-sass [options] <input.scss> [output.css]
$ cat <input.scss> | node-sass > output.css

Examples:

  1. $ node-sass my-styles.scss my-styles.css compiles a single file manually.
  2. $ node-sass my-sass-folder/ -o my-css-folder/ compiles all the files in a folder manually.
  3. $ node-sass -w sass/ -o css/ compiles all the files in a folder automatically whenever the source file(s) are modified. -w adds a watch for changes to the file(s).

More usefull options like 'compression' @ here. Command line is good for a quick solution, however, you can use task runners like Grunt.js or Gulp.js to automate the build process.

You can also add the above examples to npm scripts. To properly use npm scripts as an alternative to gulp read this comprehensive article @ css-tricks.com especially read about grouping tasks.

  • If there is no package.json file in your project directory running $ npm init will create one. Use it with -y to skip the questions.
  • Add "sass": "node-sass -w sass/ -o css/" to scripts in package.json file. It should look something like this:
"scripts": {
    "test" : "bla bla bla",
    "sass": "node-sass -w sass/ -o css/"
 }
  • $ npm run sass will compile your files.

How to use with gulp

  • $ npm install -g gulp installs Gulp globally.
  • If there is no package.json file in your project directory running $ npm init will create one. Use it with -y to skip the questions.
  • $ npm install --save-dev gulp installs Gulp locally. --save-dev adds gulp to devDependencies in package.json.
  • $ npm install gulp-sass --save-dev installs gulp-sass locally.
  • Setup gulp for your project by creating a gulpfile.js file in your project root folder with this content:
'use strict';
var gulp = require('gulp');

A basic example to transpile

Add this code to your gulpfile.js:

var gulp = require('gulp');
var sass = require('gulp-sass');
gulp.task('sass', function () {
  gulp.src('./sass/**/*.scss')
    .pipe(sass().on('error', sass.logError))
    .pipe(gulp.dest('./css'));
});

$ gulp sass runs the above task which compiles .scss file(s) in the sass folder and generates .css file(s) in the css folder.

To make life easier, let's add a watch so we don't have to compile it manually. Add this code to your gulpfile.js:

gulp.task('sass:watch', function () {
  gulp.watch('./sass/**/*.scss', ['sass']);
});

All is set now! Just run the watch task:

$ gulp sass:watch

How to use with Node.js

As the name of node-sass implies, you can write your own node.js scripts for transpiling. If you are curious, check out node-sass project page.

What about libsass?

Libsass is a library that needs to be built by an implementer such as sassC or in our case node-sass. Node-sass contains a built version of libsass which it uses by default. If the build file doesn't work on your machine, it tries to build libsass for your machine. This process requires Python 2.7.x (3.x doesn't work as of today). In addition:

LibSass requires GCC 4.6+ or Clang/LLVM. If your OS is older, this version may not compile. On Windows, you need MinGW with GCC 4.6+ or VS 2013 Update 4+. It is also possible to build LibSass with Clang/LLVM on Windows.

Microsoft.ReportViewer.Common Version=12.0.0.0

In My cases, After installing Sql server data tools by Visual Studio 2015 installer, problem has been resolved

Here is the screenshot for installing data tools

Rotating x axis labels in R for barplot

You may use

par(las=2) # make label text perpendicular to axis

It is written here: http://www.statmethods.net/graphs/bar.html

Attach parameter to button.addTarget action in Swift

Swift 5.0 code

I use theButton.tag but if i have plenty type of option, its be very long switch case. 

theButton.addTarget(self, action: #selector(theFunc), for: .touchUpInside) 
theButton.frame.name = "myParameter"

.

@objc func theFunc(sender:UIButton){ 
print(sender.frame.name)
}

How Can I Set the Default Value of a Timestamp Column to the Current Timestamp with Laravel Migrations?

In laravel 7, to set current time use following:

$table->timestamp('column_name')->useCurrent();

PHP removing a character in a string

While a regexp would suit here just fine, I'll present you with an alternative method. It might be a tad faster than the equivalent regexp, but life's all about choices (...or something).

$length = strlen($urlString);
for ($i=0; $i<$length; i++) {
  if ($urlString[$i] === '?') {
    $urlString[$i+1] = '';
    break;
  }
}

Weird, I know.

SQL: parse the first, middle and last name from a fullname field

Based on @hajili's contribution (which is a creative use of the parsename function, intended to parse the name of an object that is period-separated), I modified it so it can handle cases where the data doesn't containt a middle name or when the name is "John and Jane Doe". It's not 100% perfect but it's compact and might do the trick depending on the business case.

SELECT NAME,
CASE WHEN parsename(replace(NAME, ' ', '.'), 4) IS NOT NULL THEN 
   parsename(replace(NAME, ' ', '.'), 4) ELSE
    CASE WHEN parsename(replace(NAME, ' ', '.'), 3) IS NOT NULL THEN 
    parsename(replace(NAME, ' ', '.'), 3) ELSE
   parsename(replace(NAME, ' ', '.'), 2) end END as FirstName
   ,
CASE WHEN parsename(replace(NAME, ' ', '.'), 3) IS NOT NULL THEN 
   parsename(replace(NAME, ' ', '.'), 2) ELSE NULL END as MiddleName,
   parsename(replace(NAME, ' ', '.'), 1) as LastName
from  {@YourTableName}

Invalid character in identifier

Similar to the previous answers, the problem is some character (possibly invisible) that the Python interpreter doesn't recognize. Because this is often due to copy-pasting code, re-typing the line is one option.

But if you don't want to re-type the line, you can paste your code into this tool or something similar (Google "show unicode characters online"), and it will reveal any non-standard characters. For example,

s='    values ??=  list(analysis.values ??())'

becomes

s='    values U+200B U+200B?? =  list(analysis.values U+200B U+200B ??())'

You can then delete the non-standard characters from the string.

Heap space out of memory

No. The heap is cleared by the garbage collector whenever it feels like it. You can ask it to run (with System.gc()) but it is not guaranteed to run.

First try increasing the memory by setting -Xmx256m

how to generate a unique token which expires after 24 hours?

Use Dictionary<string, DateTime> to store token with timestamp:

static Dictionary<string, DateTime> dic = new Dictionary<string, DateTime>();

Add token with timestamp whenever you create new token:

dic.Add("yourToken", DateTime.Now);

There is a timer running to remove any expired tokens out of dic:

 timer = new Timer(1000*60); //assume run in 1 minute
 timer.Elapsed += timer_Elapsed;

 static void timer_Elapsed(object sender, ElapsedEventArgs e)
    {
        var expiredTokens = dic.Where(p => p.Value.AddDays(1) <= DateTime.Now)
                              .Select(p => p.Key);

        foreach (var key in expiredTokens)
            dic.Remove(key);
    }

So, when you authenticate token, just check whether token exists in dic or not.

Android Studio and android.support.v4.app.Fragment: cannot resolve symbol

I'm using buck and it seems like by removing the /.idea/libraries in your project folder and sync gradle again works for me.

Bootstrap 3 only for mobile

If you're looking to make the elements be 33.3% only on small devices and lower:

This is backwards from what Bootstrap is designed for, but you can do this:

<div class="row">
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
    <div class="col-xs-4 col-md-12">.col-xs-4 .col-md-12</div>
</div>

This will make each element 33.3% wide on small and extra small devices but 100% wide on medium and larger devices.

JSFiddle: http://jsfiddle.net/jdwire/sggt8/embedded/result/

If you're only looking to hide elements for smaller devices:

I think you're looking for the visible-xs and/or visible-sm classes. These will let you make certain elements only visible to small screen devices.

For example, if you want a element to only be visible to small and extra-small devices, do this:

<div class="visible-xs visible-sm">You're using a fairly small device.</div>

To show it only for larger screens, use this:

<div class="hidden-xs hidden-sm">You're probably not using a phone.</div>

See http://getbootstrap.com/css/#responsive-utilities-classes for more information.

How can I get a favicon to show up in my django app?

 
<link rel="shortcut icon" href="{% static 'favicon/favicon.ico' %}"/>

Just add that in ur base file like first answer but ico extension and add it to the static folder

How to test if a string is JSON or not?

when using jQuery $.ajax() the response will have the responseJSON property if the response was JSON, this could be checked like this:

if (xhr.hasOwnProperty('responseJSON')) {}

Angular2 module has no exported member

I was facing same issue and I just started app with new port and everything looks good.

ng serve --port 4201

Java generics - ArrayList initialization

 
ArrayList<Integer> a = new ArrayList<Number>();

Does not work because the fact that Number is a super class of Integer does not mean that List<Number> is a super class of List<Integer>. Generics are removed during compilation and do not exist on runtime, so parent-child relationship of collections cannot be be implemented: the information about element type is simply removed. 

ArrayList<? extends Object> a1 = new ArrayList<Object>();
a1.add(3);

I cannot explain why it does not work. It is really strange but it is a fact. Really syntax <? extends Object> is mostly used for return values of methods. Even in this example Object o = a1.get(0) is valid.

ArrayList<?> a = new ArrayList<?>()

This does not work because you cannot instantiate list of unknown type...

Maven won't run my Project : Failed to execute goal org.codehaus.mojo:exec-maven-plugin:1.2.1:exec

I am a beginner in Maven - don't know much about it. Carefully check on your input i.e. file path in my case. After I have carefully check, my file path is wrong so it leads to this error. After I fixed it, it works magically lol.

Changing background color of selected item in recyclerview

Add click listener for item view in .onBindViewHolder() of your RecyclerView's adapter. get currently selected position and change color by .setBackground() for previously selected and current item

How to respond to clicks on a checkbox in an AngularJS directive?

I prefer to use the ngModel and ngChange directives when dealing with checkboxes. ngModel allows you to bind the checked/unchecked state of the checkbox to a property on the entity:

<input type="checkbox" ng-model="entity.isChecked">

Whenever the user checks or unchecks the checkbox the entity.isChecked value will change too.

If this is all you need then you don't even need the ngClick or ngChange directives. Since you have the "Check All" checkbox, you obviously need to do more than just set the value of the property when someone checks a checkbox.

When using ngModel with a checkbox, it's best to use ngChange rather than ngClick for handling checked and unchecked events. ngChange is made for just this kind of scenario. It makes use of the ngModelController for data-binding (it adds a listener to the ngModelController's $viewChangeListeners array. The listeners in this array get called after the model value has been set, avoiding this problem).

<input type="checkbox" ng-model="entity.isChecked" ng-change="selectEntity()">

... and in the controller ...

var model = {};
$scope.model = model;

// This property is bound to the checkbox in the table header
model.allItemsSelected = false;

// Fired when an entity in the table is checked
$scope.selectEntity = function () {
    // If any entity is not checked, then uncheck the "allItemsSelected" checkbox
    for (var i = 0; i < model.entities.length; i++) {
        if (!model.entities[i].isChecked) {
            model.allItemsSelected = false;
            return;
        }
    }

    // ... otherwise ensure that the "allItemsSelected" checkbox is checked
    model.allItemsSelected = true;
};

Similarly, the "Check All" checkbox in the header:

<th>
    <input type="checkbox" ng-model="model.allItemsSelected" ng-change="selectAll()">
</th>

... and ...

// Fired when the checkbox in the table header is checked
$scope.selectAll = function () {
    // Loop through all the entities and set their isChecked property
    for (var i = 0; i < model.entities.length; i++) {
        model.entities[i].isChecked = model.allItemsSelected;
    }
};

CSS

What is the best way to... add a CSS class to the <tr> containing the entity to reflect its selected state?

If you use the ngModel approach for the data-binding, all you need to do is add the ngClass directive to the <tr> element to dynamically add or remove the class whenever the entity property changes:

<tr ng-repeat="entity in model.entities" ng-class="{selected: entity.isChecked}">

See the full Plunker here.

How to overcome root domain CNAME restrictions?

I see readytocloud.com is hosted on Apache 2.2.

There is a much simpler and more efficient way to redirect the non-www site to the www site in Apache.

Add the following rewrite rules to the Apache configs (either inside the virtual host or outside. It doesn't matter):

RewriteCond %{HTTP_HOST} ^readytocloud.com [NC]
RewriteRule ^/$ http://www.readytocloud.com/ [R=301,L]

Or, the following rewrite rules if you want a 1-to-1 mapping of URLs from the non-www site to the www site:

RewriteCond %{HTTP_HOST} ^readytocloud.com [NC]
RewriteRule (.*) http://www.readytocloud.com$1 [R=301,L]

Note, the mod_rewrite module needs to be loaded for this to work. Luckily readytocloud.com is runing on a CentOS box, which by default loads mod_rewrite.

We have a client server running Apache 2.2 with just under 3,000 domains and nearly 4,000 redirects, however, the load on the server hover around 0.10 - 0.20.

Combining paste() and expression() functions in plot labels

An alternative solution to that of @Aaron is the bquote() function. We need to supply a valid R expression, in this case LABEL ~ x^2 for example, where LABEL is the string you want to assign from the vector labNames. bquote evaluates R code within the expression wrapped in .( ) and subsitutes the result into the expression.

Here is an example:

labNames <- c('xLab','yLab')
xlab <- bquote(.(labNames[1]) ~ x^2)
ylab <- bquote(.(labNames[2]) ~ y^2)
plot(c(1:10), xlab = xlab, ylab = ylab)

(Note the ~ just adds a bit of spacing, if you don't want the space, replace it with * and the two parts of the expression will be juxtaposed.)

COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'latin1'

Firstly run this query

SHOW VARIABLES LIKE '%char%';

You have character_set_server='latin1'

If so,go into your config file,my.cnf and add or uncomment these lines:

character-set-server = utf8
collation-server = utf8_unicode_ci

Restart the server. Yes late to the party,just encountered the same issue.

How do I exit the Vim editor?

Pictures are worth a thousand Unix commands and options:

Enter image description here

I draw this to my students each semester and they seem to grasp vi afterwards.

vi is a finite state machine with only three states.

Upon starting, vi goes into COMMAND mode, where you can type short, few character commands, blindly. You know what you are doing; this isn't for amateurs.

When you want to actually edit text, you should go to INSERT mode with some one-character command:

  • i: go to INSERT in the place of the cursor
  • I: go to INSERT mode at the beginning of the line
  • a: append after the cursor
  • A: append at the end of line
  • o: open a new line below the current line
  • O: open a new line in the place of the current line

Now, answering the question: exiting.

You can exit vi from EX mode:

  • q: if you haven't made any modifications, or saved them beforehand
  • q!: ignores any modifications and quit
  • wq: save and quit
  • x: this is equal to wq

w and x accept a file name parameter. If you started vi with a filename, you need not give it here again.

At last, the most important: how can you reach EX mode?

EX mode is for long commands that you can see typing at the bottom line of the screen. From COMMAND mode, you push colon, :, and a colon will appear at the bottom line, where you can type the above commands.

From INSERT mode, you need to push ESC, i.e. the Escape button, going to COMMAND mode, and then : to go to EX mode.

If you are unsure, push ESC and that will bring you to command mode.

So, the robust method is ESC-:-x-Enter which saves your file and quits.

What is the maximum possible length of a .NET string?

200 megs... at which point your app grinds to a virtual halt, has about a gig working set memory, and the o/s starts to act like you'll need to reboot.

static void Main(string[] args)
{
    string s = "hello world";
    for(;;)
    {
        s = s + s.Substring(0, s.Length/10);
        Console.WriteLine(s.Length);
    }
}

12
13
14
15
16
17
18
...
158905664
174796230
192275853
211503438

How can I remove a style added with .css() function?

Try

document.body.style=''

_x000D_
_x000D_ 
$("body").css("background-color", 'red');

function clean() {
  document.body.style=''
}
_x000D_ 
body { background-color: yellow; }
_x000D_ 
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button onclick="clean()">Remove style</button>
_x000D_
_x000D_
_x000D_

Missing artifact com.oracle:ojdbc6:jar:11.2.0 in pom.xml

This is the quickest way to solve the problem but it's not recommended because its applicable only for your local system.

Download the jar, comment your previous entry for ojdbc6, and give a new local entry like so:

Previous Entry:

<!-- OJDBC6 Dependency -->
        <!-- <dependency>
            <groupId>com.oracle</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>1.0</version>
            <scope>runtime</scope>
        </dependency> -->

New Entry:

<dependency>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc6</artifactId>
        <version>1.0</version>
        <scope>system</scope>
        <systemPath>${project.basedir}/lib/ojdbc6/ojdbc6.jar</systemPath>
        </dependency>

How do I show the number keyboard on an EditText in android?

 
editText.setRawInputType(InputType.TYPE_CLASS_NUMBER);

SQL RANK() versus ROW_NUMBER()

This article covers an interesting relationship between ROW_NUMBER() and DENSE_RANK() (the RANK() function is not treated specifically). When you need a generated ROW_NUMBER() on a SELECT DISTINCT statement, the ROW_NUMBER() will produce distinct values before they are removed by the DISTINCT keyword. E.g. this query

SELECT DISTINCT
  v, 
  ROW_NUMBER() OVER (ORDER BY v) row_number
FROM t
ORDER BY v, row_number

... might produce this result (DISTINCT has no effect):

+---+------------+
| V | ROW_NUMBER |
+---+------------+
| a |          1 |
| a |          2 |
| a |          3 |
| b |          4 |
| c |          5 |
| c |          6 |
| d |          7 |
| e |          8 |
+---+------------+

Whereas this query:

SELECT DISTINCT
  v, 
  DENSE_RANK() OVER (ORDER BY v) row_number
FROM t
ORDER BY v, row_number

... produces what you probably want in this case:

+---+------------+
| V | ROW_NUMBER |
+---+------------+
| a |          1 |
| b |          2 |
| c |          3 |
| d |          4 |
| e |          5 |
+---+------------+

Note that the ORDER BY clause of the DENSE_RANK() function will need all other columns from the SELECT DISTINCT clause to work properly.

The reason for this is that logically, window functions are calculated before DISTINCT is applied.

All three functions in comparison

Using PostgreSQL / Sybase / SQL standard syntax (WINDOW clause):

SELECT
  v,
  ROW_NUMBER() OVER (window) row_number,
  RANK()       OVER (window) rank,
  DENSE_RANK() OVER (window) dense_rank
FROM t
WINDOW window AS (ORDER BY v)
ORDER BY v

... you'll get:

+---+------------+------+------------+
| V | ROW_NUMBER | RANK | DENSE_RANK |
+---+------------+------+------------+
| a |          1 |    1 |          1 |
| a |          2 |    1 |          1 |
| a |          3 |    1 |          1 |
| b |          4 |    4 |          2 |
| c |          5 |    5 |          3 |
| c |          6 |    5 |          3 |
| d |          7 |    7 |          4 |
| e |          8 |    8 |          5 |
+---+------------+------+------------+

Deprecated Java HttpClient - How hard can it be?

I would suggest using the below method if you are trying to read the json data only.

URL requestUrl=new URL(url);
URLConnection con = requestUrl.openConnection();
BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
StringBuilder sb=new StringBuilder();
int cp;
try {
    while((cp=rd.read())!=-1){
    sb.append((char)cp);
  }
 catch(Exception e){
 }
 String json=sb.toString();

Get the number of rows in a HTML table

In the DOM, a tr element is (implicitly or explicitly) a child of tbody, thead, or tfoot, not a child of table (hence the 0 you got). So a general answer is:

var count = $('#gvPerformanceResult > * > tr').length;

This includes the rows of the table but excludes rows of any inner table.

How to place a div on the right side with absolute position

Can you try the following:

float: right;