Programs & Examples On #Quantumgrid

ExpressQuantumGrid Suite is a Grid and Data Editors Library created for Delphi and C++ Builder and available for the VCL.

gradlew command not found?

the same problem occurs to me... I check the file wrx permissions with:
$ls -l ./gradlew -> -rw-rw-r-- (no execute permission)

so I use command $chmod +x ./gradlew and this problem solved.

Is Java a Compiled or an Interpreted programming language ?

enter image description here

Code written in Java is:

  • First compiled to bytecode by a program called javac as shown in the left section of the image above;
  • Then, as shown in the right section of the above image, another program called java starts the Java runtime environment and it may compile and/or interpret the bytecode by using the Java Interpreter/JIT Compiler.

When does java interpret the bytecode and when does it compile it? The application code is initially interpreted, but the JVM monitors which sequences of bytecode are frequently executed and translates them to machine code for direct execution on the hardware. For bytecode which is executed only a few times, this saves the compilation time and reduces the initial latency; for frequently executed bytecode, JIT compilation is used to run at high speed, after an initial phase of slow interpretation. Additionally, since a program spends most time executing a minority of its code, the reduced compilation time is significant. Finally, during the initial code interpretation, execution statistics can be collected before compilation, which helps to perform better optimization.

How to automatically convert strongly typed enum into int?

A C++14 version of the answer provided by R. Martinho Fernandes would be:

#include <type_traits>

template <typename E>
constexpr auto to_underlying(E e) noexcept
{
    return static_cast<std::underlying_type_t<E>>(e);
}

As with the previous answer, this will work with any kind of enum and underlying type. I have added the noexcept keyword as it will never throw an exception.


Update
This also appears in Effective Modern C++ by Scott Meyers. See item 10 (it is detailed in the final pages of the item within my copy of the book).

How do you replace all the occurrences of a certain character in a string?

I would use the translate method without translation table. It deletes the letters in second argument in recent Python versions.

def remove_chars(line):
    line7=line[7].translate(None,'abcd')
    return line[:7]+[line7]+line[8:]

line= ['ad','da','sdf','asd',
        '3424','342sfas','asdfaf','sdfa',
        'afase']
print line[7]
line = remove_chars(line)
print line[7]

Lightweight workflow engine for Java

This really depends on your requirements. First, see if you really need a workflow engine (this or other sources). Unless you really need it, probably you should avoid it.

If you really need what provides a workflow engine, I would pick one that is already built. People who works with jbpm or activiti have much more experience than you in building workflow engines, so it is probably already tunned to improve performance.

Chart creating dynamically. in .net, c#

Microsoft has a nice chart control. Download it here. Great video on this here. Example code is here. Happy coding!

Get element inside element by class and ID - JavaScript

THe easiest way to do so is:

function findChild(idOfElement, idOfChild){
  let element = document.getElementById(idOfElement);
  return element.querySelector('[id=' + idOfChild + ']');
}

or better readable:

findChild = (idOfElement, idOfChild) => {
    let element = document.getElementById(idOfElement);
    return element.querySelector(`[id=${idOfChild}]`);
}

How to pass parameters to the DbContext.Database.ExecuteSqlCommand method?

Try this (edited):

ctx.Database.ExecuteSqlCommand(sql, new SqlParameter("FirstName", firstName), 
                                    new SqlParameter("Id", id));

Previous idea was wrong.

HashMap and int as key

Use Integer instead.

HashMap<Integer, MyObject> myMap = new HashMap<Integer, MyObject>();

Java will automatically autobox your int primitive values to Integer objects.

Read more about autoboxing from Oracle Java documentations.

ASP.NET Bundles how to disable minification

Here's how to disable minification on a per-bundle basis:

bundles.Add(new StyleBundleRaw("~/Content/foobarcss").Include("/some/path/foobar.css"));
bundles.Add(new ScriptBundleRaw("~/Bundles/foobarjs").Include("/some/path/foobar.js"));

Sidenote: The paths used for your bundles must not coincide with any actual path in your published builds otherwise nothing will work. Also make sure to avoid using .js, .css and/or '.' and '_' anywhere in the name of the bundle. Keep the name as simple and as straightforward as possible, like in the example above.

The helper classes are shown below. Notice that in order to make these classes future-proof we surgically remove the js/css minifying instances instead of using .clear() and we also insert a mime-type-setter transformation without which production builds are bound to run into trouble especially when it comes to properly handing over css-bundles (firefox and chrome reject css bundles with mime-type set to "text/html" which is the default):

internal sealed class StyleBundleRaw : StyleBundle
{
        private static readonly BundleMimeType CssContentMimeType = new BundleMimeType("text/css");

        public StyleBundleRaw(string virtualPath) : this(virtualPath, cdnPath: null)
        {
        }

        public StyleBundleRaw(string virtualPath, string cdnPath) : base(virtualPath, cdnPath)
        {
                 Transforms.Add(CssContentMimeType); //0 vital
                 Transforms.Remove(Transforms.FirstOrDefault(x => x is CssMinify)); //0
        }
        //0 the guys at redmond in their infinite wisdom plugged the mimetype "text/css" right into cssminify    upon unwiring the minifier we
        //  need to somehow reenable the cssbundle to specify its mimetype otherwise it will advertise itself as html and wont load
}

internal sealed class ScriptBundleRaw : ScriptBundle
{
        private static readonly BundleMimeType JsContentMimeType = new BundleMimeType("text/javascript");

        public ScriptBundleRaw(string virtualPath) : this(virtualPath, cdnPath: null)
        {
        }

        public ScriptBundleRaw(string virtualPath, string cdnPath) : base(virtualPath, cdnPath)
        {
                 Transforms.Add(JsContentMimeType); //0 vital
                 Transforms.Remove(Transforms.FirstOrDefault(x => x is JsMinify)); //0
        }
        //0 the guys at redmond in their infinite wisdom plugged the mimetype "text/javascript" right into jsminify   upon unwiring the minifier we need
        //  to somehow reenable the jsbundle to specify its mimetype otherwise it will advertise itself as html causing it to be become unloadable by the browsers in published production builds
}

internal sealed class BundleMimeType : IBundleTransform
{
        private readonly string _mimeType;

        public BundleMimeType(string mimeType) { _mimeType = mimeType; }

        public void Process(BundleContext context, BundleResponse response)
        {
                 if (context == null)
                          throw new ArgumentNullException(nameof(context));
                 if (response == null)
                          throw new ArgumentNullException(nameof(response));

         response.ContentType = _mimeType;
        }
}

To make this whole thing work you need to install (via nuget):

WebGrease 1.6.0+ Microsoft.AspNet.Web.Optimization 1.1.3+

And your web.config should be enriched like so:

<runtime>
       [...]
       <dependentAssembly>
        <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-x.y.z.t" newVersion="x.y.z.t" />
       </dependentAssembly>
       <dependentAssembly>
              <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-x.y.z.t" newVersion="x.y.z.t" />
       </dependentAssembly>
        [...]
</runtime>

<!-- setting mimetypes like we do right below is absolutely vital for published builds because for some reason the -->
<!-- iis servers in production environments somehow dont know how to handle otf eot and other font related files   -->
<system.webServer>
        [...]
        <staticContent>
      <!-- in case iis already has these mime types -->
      <remove fileExtension=".otf" />
      <remove fileExtension=".eot" />
      <remove fileExtension=".ttf" />
      <remove fileExtension=".woff" />
      <remove fileExtension=".woff2" />

      <mimeMap fileExtension=".otf" mimeType="font/otf" />
      <mimeMap fileExtension=".eot" mimeType="application/vnd.ms-fontobject" />
      <mimeMap fileExtension=".ttf" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="application/font-woff2" />
      </staticContent>

      <!-- also vital otherwise published builds wont work  https://stackoverflow.com/a/13597128/863651  -->
      <modules runAllManagedModulesForAllRequests="true">
         <remove name="BundleModule" />
         <add name="BundleModule" type="System.Web.Optimization.BundleModule" />
      </modules>
      [...]
</system.webServer>

Note that you might have to take extra steps to make your css-bundles work in terms of fonts etc. But that's a different story.

Spring RestTemplate GET with parameters

public static void main(String[] args) {
         HttpHeaders httpHeaders = new HttpHeaders();
         httpHeaders.set("Accept", MediaType.APPLICATION_JSON_VALUE);
         final String url = "https://host:port/contract/{code}";
         Map<String, String> params = new HashMap<String, String>();
         params.put("code", "123456");
         HttpEntity<?> httpEntity  = new HttpEntity<>(httpHeaders); 
         RestTemplate restTemplate  = new RestTemplate();
         restTemplate.exchange(url, HttpMethod.GET, httpEntity,String.class, params);
    }

How to download folder from putty using ssh client

You cannot use PuTTY to download the files, but you can use PSCP from the PuTTY developers to get the files or dump any directory that you want.

Please see the following link on how to download a file/folder: https://the.earth.li/~sgtatham/putty/0.60/htmldoc/Chapter5.html

What is username and password when starting Spring Boot with Tomcat?

If spring-security jars are added in classpath and also if it is spring-boot application all http endpoints will be secured by default security configuration class SecurityAutoConfiguration

This causes a browser pop-up to ask for credentials.

The password changes for each application restarts and can be found in console.

Using default security password: 78fa095d-3f4c-48b1-ad50-e24c31d5cf35

To add your own layer of application security in front of the defaults,

@EnableWebSecurity
public class SecurityConfig {

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth
            .inMemoryAuthentication()
                .withUser("user").password("password").roles("USER");
    }
}

or if you just want to change password you could override default with,

application.xml

security.user.password=new_password

or

application.properties

spring.security.user.name=<>
spring.security.user.password=<>

How do you check if a certain index exists in a table?

-- Delete index if exists
IF EXISTS(SELECT TOP 1 1 FROM sys.indexes indexes INNER JOIN sys.objects 
objects ON indexes.object_id = objects.object_id WHERE indexes.name 
='Your_Index_Name' AND objects.name = 'Your_Table_Name')
BEGIN
    PRINT 'DROP INDEX [Your_Index_Name] ON [dbo].[Your_Table_Name]'
    DROP INDEX [our_Index_Name] ON [dbo].[Your_Table_Name]
END
GO

how do I create an infinite loop in JavaScript

By omitting all parts of the head, the loop can also become infinite:

for (;;) {}

How to stop VMware port error of 443 on XAMPP Control Panel v3.2.1

Connecting to shared virtual machines

Connection to VMware Workstation Server (the shared virtual machines) is administered by the VMware Host Agent service. The service uses TCP ports 80 and 443. This service is also used by other VMware products, including VMware Server and vSphere, and provides additional capabilities. Configuring shared virtual machines

With the Shared VMs Workstation preferences, you can disable/enable the server, assign a different port for connecting, and change the Shared VMs directory.

To access the Shared VMs Workstation preferences:

Go to Edit > Preferences.
Click the Shared VMs tab.

ASP.NET MVC: Custom Validation by DataAnnotation

To improve Darin's answer, it can be bit shorter:

public class UniqueFileName : ValidationAttribute
{
    private readonly NewsService _newsService = new NewsService();

    public override bool IsValid(object value)
    {
        if (value == null) { return false; }

        var file = (HttpPostedFile) value;

        return _newsService.IsFileNameUnique(file.FileName);
    }
}

Model:

[UniqueFileName(ErrorMessage = "This file name is not unique.")]

Do note that an error message is required, otherwise the error will be empty.

Apache VirtualHost and localhost

It may be because your web folder (as mentioned "/Applications/MAMP/htdocs/mysite/web") is empty.

My suggestion is first to make your project and then work on making the virtual host.

I went with a similar situation. I was using an empty folder in the DocumentRoot in httpd-vhosts.confiz and I couldn't access my shahg101.com site.

Python Prime number checker

a=input("Enter number:")

def isprime(): 

    total=0
    factors=(1,a)# The only factors of a number
    pfactors=range(1,a+1) #considering all possible factors


    if a==1 or a==0:# One and Zero are not prime numbers
        print "%d is NOT prime"%a


    elif a==2: # Two is the only even prime number
        print "%d is  prime"%a


    elif a%2==0:#Any even number is not prime except two
        print "%d is NOT prime"%a  



    else:#a number is prime if its multiples are 1 and itself 
         #The sum of the number that return zero moduli should be equal to the "only" factors
        for number in pfactors: 
            if (a%number)==0: 
                total+=number
        if total!=sum(factors):
            print "%d is NOT prime"%a 
        else:
             print "%d is  prime"%a
isprime()

Case vs If Else If: Which is more efficient?

i think it's just the debugger making it simple. Note that a case and "if list" are not ultimately the same. There is is a reason why case blocks normally end with "break". The case stmt actually looks something like this when broken down in assembly.

if myObject.GetType() == type of Car
    GOTO START_CAR
else if myObject.GetType() == type of Bike
    GOTO START_BIKE

LABEL START_CAR
//do something car     
GOTO END

LABEL START_BIKE
//do something bike  
GOTO END

LABEL END

If you don't have the break, then the case blocks would be missing the "GOTO END" stmts, and in fact if you landed in the "car" case you'd actually run both sections

//do something car     
//do something bike  
GOTO END

How to get the indexpath.row when an element is activated?

I used convertPoint method to get point from tableview and pass this point to indexPathForRowAtPoint method to get indexPath

 @IBAction func newsButtonAction(sender: UIButton) {
        let buttonPosition = sender.convertPoint(CGPointZero, toView: self.newsTableView)
        let indexPath = self.newsTableView.indexPathForRowAtPoint(buttonPosition)
        if indexPath != nil {
            if indexPath?.row == 1{
                self.performSegueWithIdentifier("alertViewController", sender: self);
            }   
        }
    }

Angular2: child component access parent class variable/function

You can do this In the parent component declare:

get self(): ParenComponentClass {
        return this;
    }

In the child component,after include the import of ParenComponentClass, declare:

private _parent: ParenComponentClass ;
@Input() set parent(value: ParenComponentClass ) {
    this._parent = value;
}

get parent(): ParenComponentClass {
    return this._parent;
}

Then in the template of the parent you can do

<childselector [parent]="self"></childselector>

Now from the child you can access public properties and methods of parent using

this.parent

In PowerShell, how do I test whether or not a specific variable exists in global scope?

Simple: [boolean](get-variable "Varname" -ErrorAction SilentlyContinue)

PHP pass variable to include

I've run into this issue where I had a file that sets variables based on the GET parameters. And that file could not updated because it worked correctly on another part of a large content management system. Yet I wanted to run that code via an include file without the parameters actually being in the URL string. The simple solution is you can set the GET variables in first file as you would any other variable.

Instead of:

include "myfile.php?var=apple";

It would be:

$_GET['var'] = 'apple';
include "myfile.php";

HTML5 Pre-resize images before uploading

Resizing images in a canvas element is generally bad idea since it uses the cheapest box interpolation. The resulting image noticeable degrades in quality. I'd recommend using http://nodeca.github.io/pica/demo/ which can perform Lanczos transformation instead. The demo page above shows difference between canvas and Lanczos approaches.

It also uses web workers for resizing images in parallel. There is also WEBGL implementation.

There are some online image resizers that use pica for doing the job, like https://myimageresizer.com

How to select all columns, except one column in pandas?

Don't use ix. It's deprecated. The most readable and idiomatic way of doing this is df.drop():

>>> df

          a         b         c         d
0  0.175127  0.191051  0.382122  0.869242
1  0.414376  0.300502  0.554819  0.497524
2  0.142878  0.406830  0.314240  0.093132
3  0.337368  0.851783  0.933441  0.949598

>>> df.drop('b', axis=1)

          a         c         d
0  0.175127  0.382122  0.869242
1  0.414376  0.554819  0.497524
2  0.142878  0.314240  0.093132
3  0.337368  0.933441  0.949598

Note that by default, .drop() does not operate inplace; despite the ominous name, df is unharmed by this process. If you want to permanently remove b from df, do df.drop('b', inplace=True).

df.drop() also accepts a list of labels, e.g. df.drop(['a', 'b'], axis=1) will drop column a and b.

pandas groupby sort descending order

Similar to one of the answers above, but try adding .sort_values() to your .groupby() will allow you to change the sort order. If you need to sort on a single column, it would look like this:

df.groupby('group')['id'].count().sort_values(ascending=False)

ascending=False will sort from high to low, the default is to sort from low to high.

*Careful with some of these aggregations. For example .size() and .count() return different values since .size() counts NaNs.

What is the difference between size and count in pandas?

How can I enable or disable the GPS programmatically on Android?

This is the best solution provided by Google Developers. Simply call this method in onResume of onCreate after initializing GoogleApiClient.

private void updateMarkers() {
    if (mMap == null) {
        return;
    }

    if (mLocationPermissionGranted) {
        // Get the businesses and other points of interest located
        // nearest to the device's current location.
         mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API).build();
        mGoogleApiClient.connect();
        LocationRequest locationRequest = LocationRequest.create();
        locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        locationRequest.setInterval(10000);
        locationRequest.setFastestInterval(10000 / 2);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder().addLocationRequest(locationRequest);
        builder.setAlwaysShow(true);


        LocationSettingsRequest.Builder builder = new LocationSettingsRequest
                .Builder()
                .addLocationRequest(mLocationRequest);
        PendingResult<LocationSettingsResult> resultPendingResult = LocationServices
                .SettingsApi
                .checkLocationSettings(mGoogleApiClient, builder.build());

        resultPendingResult.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(@NonNull LocationSettingsResult locationSettingsResult) {
                final Status status = locationSettingsResult.getStatus();
                final LocationSettingsStates locationSettingsStates = locationSettingsResult.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can
                        // initialize location requests here.

                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied, but this can be fixed
                        // by showing the user a dialog.


                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    MainActivity.this,
                                    PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.


                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way
                        // to fix the settings so we won't show the dialog.


                        break;
                }

            }
        });


        @SuppressWarnings("MissingPermission")
        PendingResult<PlaceLikelihoodBuffer> result = Places.PlaceDetectionApi
                .getCurrentPlace(mGoogleApiClient, null);
        result.setResultCallback(new ResultCallback<PlaceLikelihoodBuffer>() {
            @Override
            public void onResult(@NonNull PlaceLikelihoodBuffer likelyPlaces) {
                for (PlaceLikelihood placeLikelihood : likelyPlaces) {
                    // Add a marker for each place near the device's current location, with an
                    // info window showing place information.
                    String attributions = (String) placeLikelihood.getPlace().getAttributions();
                    String snippet = (String) placeLikelihood.getPlace().getAddress();
                    if (attributions != null) {
                        snippet = snippet + "\n" + attributions;
                    }

                    mMap.addMarker(new MarkerOptions()
                            .position(placeLikelihood.getPlace().getLatLng())
                            .title((String) placeLikelihood.getPlace().getName())
                            .snippet(snippet));
                }
                // Release the place likelihood buffer.
                likelyPlaces.release();
            }
        });
    } else {
        mMap.addMarker(new MarkerOptions()
                .position(mDefaultLocation)
                .title(getString(R.string.default_info_title))
                .snippet(getString(R.string.default_info_snippet)));
    }
}

Note : This line of code automatic open the dialog box if Location is not on. This piece of line is used in Google Map also

 status.startResolutionForResult(
 MainActivity.this,
 PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);

Get Filename Without Extension in Python

You can use stem method to get file name.

Here is an example:

from pathlib import Path

p = Path(r"\\some_directory\subdirectory\my_file.txt")
print(p.stem)
# my_file

How can I enable CORS on Django REST Framework

pip install django-cors-headers

and then add it to your installed apps:

INSTALLED_APPS = (
    ...
    'corsheaders',
    ...
)

You will also need to add a middleware class to listen in on responses:

MIDDLEWARE_CLASSES = (
    ...
    'corsheaders.middleware.CorsMiddleware',  
    'django.middleware.common.CommonMiddleware',  
    ...
)

CORS_ORIGIN_ALLOW_ALL = True # If this is used then `CORS_ORIGIN_WHITELIST` will not have any effect
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_WHITELIST = [
    'http://localhost:3030',
] # If this is used, then not need to use `CORS_ORIGIN_ALLOW_ALL = True`
CORS_ORIGIN_REGEX_WHITELIST = [
    'http://localhost:3030',
]

more details: https://github.com/ottoyiu/django-cors-headers/#configuration

read the official documentation can resolve almost all problem

Delete all lines starting with # or ; in Notepad++

In Notepad++, you can use the Mark tab in the Find dialogue to Bookmark all lines matching your query which can be regex or normal (wildcard).

Then use Search > Bookmark > Remove Bookmarked Lines.

How to get first and last day of previous month (with timestamp) in SQL Server

From SQL2012, there is a new function introduced called EOMONTH. Using this function the first and last day of the last month can be easily found.

select DATEADD(DD,1,EOMONTH(Getdate(),-2)) firstdayoflastmonth, EOMONTH(Getdate(), -1) lastdayoflastmonth

How to find indices of all occurrences of one string in another in JavaScript?

Use String.prototype.match.

Here is an example from the MDN docs itself:

var str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
var regexp = /[A-E]/gi;
var matches_array = str.match(regexp);

console.log(matches_array);
// ['A', 'B', 'C', 'D', 'E', 'a', 'b', 'c', 'd', 'e']

How do you view ALL text from an ntext or nvarchar(max) in SSMS?

Quick trick-

SELECT CAST('<A><![CDATA[' + CAST(LogInfo as nvarchar(max)) + ']]></A>' AS xml)
FROM Logs
WHERE IDLog = 904862629

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

You can do it fast, only using one POSIX function. If you have bunch of tasks with dates, see the module DateTime.

use POSIX qw(strftime);

my $date = strftime "%m/%d/%Y", localtime;
print $date;

Python BeautifulSoup extract text between element

Short answer: soup.findAll('p')[0].next

Real answer: You need an invariant reference point from which you can get to your target.

You mention in your comment to Haidro's answer that the text you want is not always in the same place. Find a sense in which it is in the same place relative to some element. Then figure out how to make BeautifulSoup navigate the parse tree following that invariant path.

For example, in the HTML you provide in the original post, the target string appears immediately after the first paragraph element, and that paragraph is not empty. Since findAll('p') will find paragraph elements, soup.find('p')[0] will be the first paragraph element.

You could in this case use soup.find('p') but soup.findAll('p')[n] is more general since maybe your actual scenario needs the 5th paragraph or something like that.

The next field attribute will be the next parsed element in the tree, including children. So soup.findAll('p')[0].next contains the text of the paragraph, and soup.findAll('p')[0].next.next will return your target in the HTML provided.

How to generate unique ID with node.js

I am using the following and it is working fine plus without any third-party dependencies.

const {
  randomBytes
} = require('crypto');

const uid = Math.random().toString(36).slice(2) + randomBytes(8).toString('hex') + new Date().getTime();

Singleton in Android

EDIT :

The implementation of a Singleton in Android is not "safe" (see here) and you should use a library dedicated to this kind of pattern like Dagger or other DI library to manage the lifecycle and the injection.


Could you post an example from your code ?

Take a look at this gist : https://gist.github.com/Akayh/5566992

it works but it was done very quickly :

MyActivity : set the singleton for the first time + initialize mString attribute ("Hello") in private constructor and show the value ("Hello")

Set new value to mString : "Singleton"

Launch activityB and show the mString value. "Singleton" appears...

mysql data directory location

If you are using macOS {mine 'High Sierra'} and Installed XAMPP

You can find mysql data files;

Go to : /Applications/XAMPP/xamppfiles/var/mysql/

How to check if a process is running via a batch script

I don't know how to do so with built in CMD but if you have grep you can try the following:

tasklist /FI "IMAGENAME eq myApp.exe" | grep myApp.exe
if ERRORLEVEL 1 echo "myApp is not running"

IOCTL Linux device driver

The ioctl function is useful for implementing a device driver to set the configuration on the device. e.g. a printer that has configuration options to check and set the font family, font size etc. ioctl could be used to get the current font as well as set the font to a new one. A user application uses ioctl to send a code to a printer telling it to return the current font or to set the font to a new one.

int ioctl(int fd, int request, ...)
  1. fd is file descriptor, the one returned by open;
  2. request is request code. e.g GETFONT will get the current font from the printer, SETFONT will set the font on the printer;
  3. the third argument is void *. Depending on the second argument, the third may or may not be present, e.g. if the second argument is SETFONT, the third argument can be the font name such as "Arial";

int request is not just a macro. A user application is required to generate a request code and the device driver module to determine which configuration on device must be played with. The application sends the request code using ioctl and then uses the request code in the device driver module to determine which action to perform.

A request code has 4 main parts

    1. A Magic number - 8 bits
    2. A sequence number - 8 bits
    3. Argument type (typically 14 bits), if any.
    4. Direction of data transfer (2 bits).  

If the request code is SETFONT to set font on a printer, the direction for data transfer will be from user application to device driver module (The user application sends the font name "Arial" to the printer). If the request code is GETFONT, direction is from printer to the user application.

In order to generate a request code, Linux provides some predefined function-like macros.

1._IO(MAGIC, SEQ_NO) both are 8 bits, 0 to 255, e.g. let us say we want to pause printer. This does not require a data transfer. So we would generate the request code as below

#define PRIN_MAGIC 'P'
#define NUM 0
#define PAUSE_PRIN __IO(PRIN_MAGIC, NUM) 

and now use ioctl as

ret_val = ioctl(fd, PAUSE_PRIN);

The corresponding system call in the driver module will receive the code and pause the printer.

  1. __IOW(MAGIC, SEQ_NO, TYPE) MAGIC and SEQ_NO are the same as above, and TYPE gives the type of the next argument, recall the third argument of ioctl is void *. W in __IOW indicates that the data flow is from user application to driver module. As an example, suppose we want to set the printer font to "Arial".
#define PRIN_MAGIC 'S'
#define SEQ_NO 1
#define SETFONT __IOW(PRIN_MAGIC, SEQ_NO, unsigned long)

further,

char *font = "Arial";
ret_val = ioctl(fd, SETFONT, font); 

Now font is a pointer, which means it is an address best represented as unsigned long, hence the third part of _IOW mentions type as such. Also, this address of font is passed to corresponding system call implemented in device driver module as unsigned long and we need to cast it to proper type before using it. Kernel space can access user space and hence this works. other two function-like macros are __IOR(MAGIC, SEQ_NO, TYPE) and __IORW(MAGIC, SEQ_NO, TYPE) where the data flow will be from kernel space to user space and both ways respectively.

Please let me know if this helps!

Laravel 5 Class 'form' not found

In Laravel Version - 4, HTML and Form existed, but not now.

Why:

The only reason is they have collected some user requirements and they want it more lightweight and so they removed it as in the sense that a user can add it manually.

What to do to add HTML & Forms in Laravel 5.2 or 5.3:

For 5.2:

Go to the Laravel Collective site and installation processes have demonstrated their.

Like for 5.2: on the command line, run the command

composer require "laravelcollective/html":"^5.2.0"

Then, in the provider array which is in config/app.php. Add this line at last using a comma(,):

Collective\Html\HtmlServiceProvider::class,

For using HTML and FORM text we need to alias them in the aliases array of config/app.php. Add the two lines at the last

'Form' => Collective\Html\FormFacade::class,
'Html' => Collective\Html\HtmlFacade::class,

And for 5.3:

Just run the command

composer require "laravelcollective/html":"^5.3.0"

And the rest of the procedure is like 5.2.

Then you can use Laravel Form and other HTML links in your projects. For this, follow this documentation:

5.2: https://laravelcollective.com/docs/5.2/html

5.3: https://laravelcollective.com/docs/5.3/html

Demo Code:

To open a form, open and close a tag:

{!! Form::open(['url' => 'foo/bar']) !!}

{!! Form::close() !!}

And for creating label and input text with a Bootstrap form-control class and other use:

{!! Form::label('title', 'Post Title') !!}
{!! Form::text('title', null, array('class' => 'form-control')) !!}

And for more, use the documentation, https://laravelcollective.com/.

Basic CSS - how to overlay a DIV with semi-transparent DIV on top

.foo {
   position : relative;
}
.foo .wrapper {
    background-image : url('semi-trans.png');
    z-index : 10;
    position : absolute;
    top : 0;
    left : 0;
}

<div class="foo">
   <img src="example.png" />
   <div class="wrapper">&nbsp;</div>
</div>

How do I remove a key from a JavaScript object?

It's as easy as:

delete object.keyname;

or

delete object["keyname"];

iOS how to set app icon and launch images

Update: Unless you love resizing icons one by one, check out Schmoudi's answer. It's just a lot easier.

Icon sizes

enter image description here

Above image from Designing for iOS 9. They are the same for iOS 10.

How to Set the App Icon

Click Assets.xcassets in the Project navigator and then choose AppIcon.

enter image description here

This will give you an empty app icon set.

enter image description here

Now just drag the right sized image (in .png format) from Finder onto every blank in the app set. The app icon should be all set up now.

How to create the right sized images

The image at the very top tells the pixels sizes for for each point size that is required in iOS 9. However, even if I don't get this answer updated for future versions of iOS, you can still figure out the correct pixel sizes using the method below.

Look at how many points (pt) each blank on the empty image set is. If the image is 1x then the pixels are the same as the points. For 2x double the points and 3x triple the points. So, for example, in the first blank above (29pt 2x) you would need a 58x58 pixel image.

You can start with a 1024x1024 pixel image and then downsize it to the correct sizes. You can do it yourself or there are also websites and scripts for getting the right sizes. Do a search for "ios app icon generator" or something similar.

I don't think the names matter as long as you get the dimensions right, but the general naming convention is as follows:

Icon-29.png      // 29x29 pixels
[email protected]   // 58x58 pixels
[email protected]   // 87x87 pixels

Launch Image

Although you can use an image for the launch screen, consider using a launch screen storyboard file. This will conveniently resize for every size and orientation. Check out this SO answer or the following documentation for help with this.

Useful documentation

The Xcode images in this post were created with Xcode 7.

How to iterate through XML in Powershell?

You can also do it without the [xml] cast. (Although xpath is a world unto itself. https://www.w3schools.com/xml/xml_xpath.asp)

$xml = (select-xml -xpath / -path stack.xml).node
$xml.objects.object.property

Or just this, xpath is case sensitive. Both have the same output:

$xml = (select-xml -xpath /Objects/Object/Property -path stack.xml).node
$xml


Name         Type                                                #text
----         ----                                                -----
DisplayName  System.String                                       SQL Server (MSSQLSERVER)
ServiceState Microsoft.SqlServer.Management.Smo.Wmi.ServiceState Running
DisplayName  System.String                                       SQL Server Agent (MSSQLSERVER)
ServiceState Microsoft.SqlServer.Management.Smo.Wmi.ServiceState Stopped

How to configure the web.config to allow requests of any length

If your website is using authentication, but you don't have the correct authentication method set up in IIS (e.g. Basic, Forms etc..) then the browser will be getting stuck in a redirect loop. This causes the redirect url to get longer and longer until it explodes.

Fixed footer in Bootstrap

To get a footer that sticks to the bottom of your viewport, give it a fixed position like this:

footer {
    position: fixed;
    height: 100px;
    bottom: 0;
    width: 100%;
}

Bootstrap includes this CSS in the Navbar > Placement section with the class fixed-bottom. Just add this class to your footer element:

<footer class="fixed-bottom">

Bootstrap docs: https://getbootstrap.com/docs/4.4/utilities/position/#fixed-bottom

How to apply `git diff` patch without Git installed?

I use

patch -p1 --merge < patchfile

This way, conflicts may be resolved as usual.

Count number of days between two dates

Very late, but it may help others:

end_date.mjd - start_date.mjd

https://apidock.com/ruby/Date/mjd

Redraw datatables after using ajax to refresh the table content?

It looks as if you could use the API functions to

  • clear the table ( fnClearTable )
  • add new data to the table ( fnAddData)
  • redraw the table ( fnDraw )

http://datatables.net/api

UPDATE

I guess you're using the DOM Data Source (for server-side processing) to generate your table. I didn't really get that at first, so my previous answer won't work for that.

To get it to work without rewriting your server side code:

What you'll need to do is totally remove the old table (in the dom) and replace it with the ajax result content, then reinitialize the datatable:

// in your $.post callback:

function (data) {

    // remove the old table
    $("#ajaxresponse").children().remove();

    // replace with the new table
    $("#ajaxresponse").html(data);

    // reinitialize the datatable
    $('#rankings').dataTable( {
    "sDom":'t<"bottom"filp><"clear">',
    "bAutoWidth": false,
    "sPaginationType": "full_numbers",
        "aoColumns": [ 
        { "bSortable": false, "sWidth": "10px" },
        null,
        null,
        null,
        null,
        null,
        null,
        null,
        null,
        null,
        null,
        null
        ]

    } 
    );
}

What is the difference between % and %% in a cmd file?

In DOS you couldn't use environment variables on the command line, only in batch files, where they used the % sign as a delimiter. If you wanted a literal % sign in a batch file, e.g. in an echo statement, you needed to double it.

This carried over to Windows NT which allowed environment variables on the command line, however for backwards compatibility you still need to double your % signs in a .cmd file.

BadValue Invalid or no user locale set. Please ensure LANG and/or LC_* environment variables are set correctly

Amazon Linux AMI

Permanent solution for ohmyzsh:

$ vim ~/.zshrc

Write there below:

export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
export LANGUAGE=en_US.UTF-8

Update changes in current shell by: $ source ~/.zshrc

When should I use semicolons in SQL Server?

From a SQLServerCentral.Com article by Ken Powers:

The Semicolon

The semicolon character is a statement terminator. It is a part of the ANSI SQL-92 standard, but was never used within Transact-SQL. Indeed, it was possible to code T-SQL for years without ever encountering a semicolon.

Usage

There are two situations in which you must use the semicolon. The first situation is where you use a Common Table Expression (CTE), and the CTE is not the first statement in the batch. The second is where you issue a Service Broker statement and the Service Broker statement is not the first statement in the batch.

Make xargs execute the command once for each line of input

If you want to run the command for every line (i.e. result) coming from find, then what do you need the xargs for?

Try:

find path -type f -exec your-command {} \;

where the literal {} gets substituted by the filename and the literal \; is needed for find to know that the custom command ends there.

EDIT:

(after the edit of your question clarifying that you know about -exec)

From man xargs:

-L max-lines
Use at most max-lines nonblank input lines per command line. Trailing blanks cause an input line to be logically continued on the next input line. Implies -x.

Note that filenames ending in blanks would cause you trouble if you use xargs:

$ mkdir /tmp/bax; cd /tmp/bax
$ touch a\  b c\  c
$ find . -type f -print | xargs -L1 wc -l
0 ./c
0 ./c
0 total
0 ./b
wc: ./a: No such file or directory

So if you don't care about the -exec option, you better use -print0 and -0:

$ find . -type f -print0 | xargs -0L1 wc -l
0 ./c
0 ./c
0 ./b
0 ./a

String concatenation: concat() vs "+" operator

I don't think so.

a.concat(b) is implemented in String and I think the implementation didn't change much since early java machines. The + operation implementation depends on Java version and compiler. Currently + is implemented using StringBuffer to make the operation as fast as possible. Maybe in the future, this will change. In earlier versions of java + operation on Strings was much slower as it produced intermediate results.

I guess that += is implemented using + and similarly optimized.

Convert file path to a file URI?

UrlCreateFromPath to the rescue! Well, not entirely, as it doesn't support extended and UNC path formats, but that's not so hard to overcome:

public static Uri FileUrlFromPath(string path)
{
    const string prefix = @"\\";
    const string extended = @"\\?\";
    const string extendedUnc = @"\\?\UNC\";
    const string device = @"\\.\";
    const StringComparison comp = StringComparison.Ordinal;

    if(path.StartsWith(extendedUnc, comp))
    {
        path = prefix+path.Substring(extendedUnc.Length);
    }else if(path.StartsWith(extended, comp))
    {
        path = prefix+path.Substring(extended.Length);
    }else if(path.StartsWith(device, comp))
    {
        path = prefix+path.Substring(device.Length);
    }

    int len = 1;
    var buffer = new StringBuilder(len);
    int result = UrlCreateFromPath(path, buffer, ref len, 0);
    if(len == 1) Marshal.ThrowExceptionForHR(result);

    buffer.EnsureCapacity(len);
    result = UrlCreateFromPath(path, buffer, ref len, 0);
    if(result == 1) throw new ArgumentException("Argument is not a valid path.", "path");
    Marshal.ThrowExceptionForHR(result);
    return new Uri(buffer.ToString());
}

[DllImport("shlwapi.dll", CharSet=CharSet.Auto, SetLastError=true)]
static extern int UrlCreateFromPath(string path, StringBuilder url, ref int urlLength, int reserved);

In case the path starts with with a special prefix, it gets removed. Although the documentation doesn't mention it, the function outputs the length of the URL even if the buffer is smaller, so I first obtain the length and then allocate the buffer.

Some very interesting observation I had is that while "\\device\path" is correctly transformed to "file://device/path", specifically "\\localhost\path" is transformed to just "file:///path".

The WinApi function managed to encode special characters, but leaves Unicode-specific characters unencoded, unlike the Uri construtor. In that case, AbsoluteUri contains the properly encoded URL, while OriginalString can be used to retain the Unicode characters.

Object reference not set to an instance of an object.

strSearch in this case is probably null (not simply empty).

Try using

String.IsNullOrEmpty(strSearch)

if you are just trying to determine if the string doesn't have any contents.

Write Base64-encoded image to file

No need to use BufferedImage, as you already have the image file in a byte array

    byte dearr[] = Base64.decodeBase64(crntImage);
    FileOutputStream fos = new FileOutputStream(new File("c:/decode/abc.bmp")); 
    fos.write(dearr); 
    fos.close();

What does it mean when a PostgreSQL process is "idle in transaction"?

The PostgreSQL manual indicates that this means the transaction is open (inside BEGIN) and idle. It's most likely a user connected using the monitor who is thinking or typing. I have plenty of those on my system, too.

If you're using Slony for replication, however, the Slony-I FAQ suggests idle in transaction may mean that the network connection was terminated abruptly. Check out the discussion in that FAQ for more details.

Check if an array is empty or exists

Using undescore or lodash:

_.isArray(image_array) && !_.isEmpty(image_array)

Converting time stamps in excel to dates

This worked for me:

=(col_name]/60/60/24)+(col_name-1)

How to show validation message below each textbox using jquery?

Here you go:

JS:

$('form').on('submit', function (e) {
    e.preventDefault();

    if (!$('#email').val()) 
        $('#email').parent().append('<span class="error">Please enter your email address.</span>');


    if(!$('#password').val())
         $('#password').parent().append('<span class="error">Please enter your password.</span>');
});

CSS:

@charset "utf-8";
/* CSS Document */

/* ---------- FONTAWESOME ---------- */
/* ---------- http://fortawesome.github.com/Font-Awesome/ ---------- */
/* ---------- http://weloveiconfonts.com/ ---------- */

@import url(http://weloveiconfonts.com/api/?family=fontawesome);

/* ---------- ERIC MEYER'S RESET CSS ---------- */
/* ---------- http://meyerweb.com/eric/tools/css/reset/ ---------- */

@import url(http://meyerweb.com/eric/tools/css/reset/reset.css);

/* ---------- FONTAWESOME ---------- */

[class*="fontawesome-"]:before {
  font-family: 'FontAwesome', sans-serif;
}

/* ---------- GENERAL ---------- */

body {
    background-color: #C0C0C0;
    color: #000;
    font-family: "Varela Round", Arial, Helvetica, sans-serif;
    font-size: 16px;
    line-height: 1.5em;
}

input {
    border: none;
    font-family: inherit;
    font-size: inherit;
    font-weight: inherit;
    line-height: inherit;
    -webkit-appearance: none;
}

/* ---------- LOGIN ---------- */

#login {
    margin: 50px auto;
    width: 400px;
}

#login h2 {
    background-color: #f95252;
    -webkit-border-radius: 20px 20px 0 0;
    -moz-border-radius: 20px 20px 0 0;
    border-radius: 20px 20px 0 0;
    color: #fff;
    font-size: 28px;
    padding: 20px 26px;
}

#login h2 span[class*="fontawesome-"] {
    margin-right: 14px;
}

#login fieldset {
    background-color: #fff;
    -webkit-border-radius: 0 0 20px 20px;
    -moz-border-radius: 0 0 20px 20px;
    border-radius: 0 0 20px 20px;
    padding: 20px 26px;
}

#login fieldset div {
    color: #777;
    margin-bottom: 14px;
}

#login fieldset p:last-child {
    margin-bottom: 0;
}

#login fieldset input {
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
}

#login fieldset .error {
    display: block;
     color: #FF1000;
    font-size: 12px;
}
}

#login fieldset input[type="email"], #login fieldset input[type="password"] {
    background-color: #eee;
    color: #777;
    padding: 4px 10px;
    width: 328px;
}

#login fieldset input[type="submit"] {
    background-color: #33cc77;
    color: #fff;
    display: block;
    margin: 0 auto;
    padding: 4px 0;
    width: 100px;
}

#login fieldset input[type="submit"]:hover {
    background-color: #28ad63;
}

HTML:

<div id="login">

<h2><span class="fontawesome-lock"></span>Sign In</h2>

<form action="javascript:void(0);" method="POST">

    <fieldset>

        <div><label for="email">E-mail address</label></div>
        <div><input type="email" id="email" /></div>

        <div><label for="password">Password</label></div>
        <div><input type="password" id="password" /></div> <!-- JS because of IE support; better: placeholder="Email" -->

        <div><input type="submit" value="Sign In"></div>

    </fieldset>

</form>

And the fiddle: jsfiddle

Find out the history of SQL queries

    select v.SQL_TEXT,
           v.PARSING_SCHEMA_NAME,
           v.FIRST_LOAD_TIME,
           v.DISK_READS,
           v.ROWS_PROCESSED,
           v.ELAPSED_TIME,
           v.service
      from v$sql v
where to_date(v.FIRST_LOAD_TIME,'YYYY-MM-DD hh24:mi:ss')>ADD_MONTHS(trunc(sysdate,'MM'),-2)

where clause is optional. You can sort the results according to FIRST_LOAD_TIME and find the records up to 2 months ago.

Count frequency of words in a list and sort by frequency

One way would be to make a list of lists, with each sub-list in the new list containing a word and a count:

list1 = []    #this is your original list of words
list2 = []    #this is a new list

for word in list1:
    if word in list2:
        list2.index(word)[1] += 1
    else:
        list2.append([word,0])

Or, more efficiently:

for word in list1:
    try:
        list2.index(word)[1] += 1
    except:
        list2.append([word,0])

This would be less efficient than using a dictionary, but it uses more basic concepts.

wamp server does not start: Windows 7, 64Bit

You just need Visual C++ runtime 2015 installed, if you change your php version to the newest version you will get the error for it. this is why apache has php dependency error.

Best way to make a shell script daemon?

# double background your script to have it detach from the tty
# cf. http://www.linux-mag.com/id/5981 
(./program.sh &) & 

Send POST data using XMLHttpRequest

This helped me as I wanted to use only xmlHttpRequest and post an object as form data:

function sendData(data) {
  var XHR = new XMLHttpRequest();
  var FD  = new FormData();

  // Push our data into our FormData object
  for(name in data) {
    FD.append(name, data[name]);
  }

  // Set up our request
  XHR.open('POST', 'https://example.com/cors.php');

  // Send our FormData object; HTTP headers are set automatically
  XHR.send(FD);
}

https://developer.mozilla.org/en-US/docs/Learn/HTML/Forms/Sending_forms_through_JavaScript

Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister

You are missing setter for salt property as indicated by the exception

Please add the setter as

 public void setSalt(long salt) {
      this.salt=salt;
 }

"SyntaxError: Unexpected token < in JSON at position 0"

My problem was that I was getting the data back in a string which was not in a proper JSON format, which I was then trying to parse it. simple example: JSON.parse('{hello there}') will give an error at h. In my case the callback url was returning an unnecessary character before the objects: employee_names([{"name":.... and was getting error at e at 0. My callback URL itself had an issue which when fixed, returned only objects.

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

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

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

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


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

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

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

xpath find if node exists

Patrick is correct, both in the use of the xsl:if, and in the syntax for checking for the existence of a node. However, as Patrick's response implies, there is no xsl equivalent to if-then-else, so if you are looking for something more like an if-then-else, you're normally better off using xsl:choose and xsl:otherwise. So, Patrick's example syntax will work, but this is an alternative:

<xsl:choose>
 <xsl:when test="/html/body">body node exists</xsl:when>
 <xsl:otherwise>body node missing</xsl:otherwise>
</xsl:choose>

Converting string into datetime

Check out strptime in the time module. It is the inverse of strftime.

$ python
>>> import time
>>> my_time = time.strptime('Jun 1 2005  1:33PM', '%b %d %Y %I:%M%p')
time.struct_time(tm_year=2005, tm_mon=6, tm_mday=1,
                 tm_hour=13, tm_min=33, tm_sec=0,
                 tm_wday=2, tm_yday=152, tm_isdst=-1)

timestamp = time.mktime(my_time)
# convert time object to datetime
from datetime import datetime
my_datetime = datetime.fromtimestamp(timestamp)
# convert time object to date
from datetime import date
my_date = date.fromtimestamp(timestamp)

How to update gradle in android studio?

Select android\gradle\wrapper and open gradle-wrapper.properties

change: distributionUrl=https://services.gradle.org/distributions/gradle-older-version-to-new-version.zip

eg: distributionUrl=https://services.gradle.org/distributions/gradle-5.1.1-all.zip and rebuild your project

open() in Python does not create a file if it doesn't exist

What do you want to do with file? Only writing to it or both read and write?

'w', 'a' will allow write and will create the file if it doesn't exist.

If you need to read from a file, the file has to be exist before open it. You can test its existence before opening it or use a try/except.

angularjs - using {{}} binding inside ng-src but ng-src doesn't load

Changing the ng-src value is actually very simple. Like this:

<html ng-app>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
</head>
<body>
<img ng-src="{{img_url}}">
<button ng-click="img_url = 'https://farm4.staticflickr.com/3261/2801924702_ffbdeda927_d.jpg'">Click</button>
</body>
</html>

Here is a jsFiddle of a working example: http://jsfiddle.net/Hx7B9/2/

White space at top of page

overflow: auto

Using overflow: auto on the <body> tag is a cleaner solution and will work a charm.

Still getting warning : Configuration 'compile' is obsolete and has been replaced with 'implementation'

Hope that you're affected with build.gradle(app) If do so , follow this step

Replace compile with androidTestImplementation in build.gradle

androidTestImplementation 'com.android.support:appcompat-v7:27.1.1'
androidTestImplementation 'com.android.support:design:27.1.1'

so simple ! hope this will solve

What is /var/www/html?

In the most shared hosts you can't set it.

On a VPS or dedicated server, you can set it, but everything has its price.

On shared hosts, in general you receive a Linux account, something such as /home/(your username)/, and the equivalent of /var/www/html turns to /home/(your username)/public_html/ (or something similar, such as /home/(your username)/www)

If you're accessing your account via FTP, you automatically has accessing the your */home/(your username)/ folder, just find the www or public_html and put your site in it.

If you're using absolute path in the code, bad news, you need to refactor it to use relative paths in the code, at least in a shared host.

Multiple argument IF statement - T-SQL

Your code is valid (with one exception). It is required to have code between BEGIN and END.

Replace

--do some work

with

print ''

I think maybe you saw "END and not "AND"

Ranges of floating point datatype in C?

A 32 bit floating point number has 23 + 1 bits of mantissa and an 8 bit exponent (-126 to 127 is used though) so the largest number you can represent is:

(1 + 1 / 2 + ... 1 / (2 ^ 23)) * (2 ^ 127) = 
(2 ^ 23 + 2 ^ 23 + .... 1) * (2 ^ (127 - 23)) = 
(2 ^ 24 - 1) * (2 ^ 104) ~= 3.4e38

unsigned APK can not be installed

I did not know that even with the "Allow Installation of non-Marked application", I still needed to sign the application.

I self-signed my application, following this link self-sign and release application, It only took 5 minutes, then I emailed the signed-APK file to myself and downloaded it to SD-card and then installed it without any problem.

Chrome Extension - Get DOM content

The terms "background page", "popup", "content script" are still confusing you; I strongly suggest a more in-depth look at the Google Chrome Extensions Documentation.

Regarding your question if content scripts or background pages are the way to go:

Content scripts: Definitely
Content scripts are the only component of an extension that has access to the web-page's DOM.

Background page / Popup: Maybe (probably max. 1 of the two)
You may need to have the content script pass the DOM content to either a background page or the popup for further processing.


Let me repeat that I strongly recommend a more careful study of the available documentation!
That said, here is a sample extension that retrieves the DOM content on StackOverflow pages and sends it to the background page, which in turn prints it in the console:

background.js:

// Regex-pattern to check URLs against. 
// It matches URLs like: http[s]://[...]stackoverflow.com[...]
var urlRegex = /^https?:\/\/(?:[^./?#]+\.)?stackoverflow\.com/;

// A function to use as callback
function doStuffWithDom(domContent) {
    console.log('I received the following DOM content:\n' + domContent);
}

// When the browser-action button is clicked...
chrome.browserAction.onClicked.addListener(function (tab) {
    // ...check the URL of the active tab against our pattern and...
    if (urlRegex.test(tab.url)) {
        // ...if it matches, send a message specifying a callback too
        chrome.tabs.sendMessage(tab.id, {text: 'report_back'}, doStuffWithDom);
    }
});

content.js:

// Listen for messages
chrome.runtime.onMessage.addListener(function (msg, sender, sendResponse) {
    // If the received message has the expected format...
    if (msg.text === 'report_back') {
        // Call the specified callback, passing
        // the web-page's DOM content as argument
        sendResponse(document.all[0].outerHTML);
    }
});

manifest.json:

{
  "manifest_version": 2,
  "name": "Test Extension",
  "version": "0.0",
  ...

  "background": {
    "persistent": false,
    "scripts": ["background.js"]
  },
  "content_scripts": [{
    "matches": ["*://*.stackoverflow.com/*"],
    "js": ["content.js"]
  }],
  "browser_action": {
    "default_title": "Test Extension"
  },

  "permissions": ["activeTab"]
}

How to remove the underline for anchors(links)?

Use CSS to remove text-decorations.

a {
    text-decoration: none;
}

How to use curl to get a GET request exactly same as using Chrome?

Open Chrome Developer Tools, go to Network tab, make your request (you may need to check "Preserve Log" if the page refreshes). Find the request on the left, right-click, "Copy as cURL".

Bash script error [: !=: unary operator expected

Quotes!

if [ "$1" != -v ]; then

Otherwise, when $1 is completely empty, your test becomes:

[ != -v ]

instead of

[ "" != -v ]

...and != is not a unary operator (that is, one capable of taking only a single argument).

What is the actual use of Class.forName("oracle.jdbc.driver.OracleDriver") while connecting to a database?

From the Java JDBC tutorial:

In previous versions of JDBC, to obtain a connection, you first had to initialize your JDBC driver by calling the method Class.forName. Any JDBC 4.0 drivers that are found in your class path are automatically loaded. (However, you must manually load any drivers prior to JDBC 4.0 with the method Class.forName.)

So, if you're using the Oracle 11g (11.1) driver with Java 1.6, you don't need to call Class.forName. Otherwise, you need to call it to initialise the driver.

Android REST client, Sample?

Never use AsynTask to perform network request or whatever that need to be persisted. Async Task are strongly tied to your activity and if the user change the orientation of the screen since the App is re created the AsyncTask will be stopped.

I suggest you to use Service pattern with Intent Service and ResultReceiver. Take a look to RESTDroid. It's a library that allows you to perform any kind of REST request asynchronously and notify your UI with Request Listeners implementing the Virgil Dobjanschi's service pattern.

Error - "UNION operator must have an equal number of expressions" when using CTE for recursive selection

The second result set have only one column but it should have 3 columns for it to be contented to the first result set

(columns must match when you use UNION)

Try to add ID as first column and PartOf_LOC_id to your result set, so you can do the UNION.

;
WITH    q AS ( SELECT   ID ,
                    Location ,
                    PartOf_LOC_id
           FROM     tblLocation t
           WHERE    t.ID = 1 -- 1 represents an example
           UNION ALL
           SELECT   t.ID ,
                    parent.Location + '>' + t.Location ,
                    t.PartOf_LOC_id
           FROM     tblLocation t
                    INNER JOIN q parent ON parent.ID = t.LOC_PartOf_ID
         )
SELECT  *
FROM    q

How to convert IPython notebooks to PDF and HTML?

If you are using sagemath cloud version, you can simply go to the left corner,
select File ? Download as ? Pdf via LaTeX (.pdf)
Check the screenshot if you want.

Screenshot Convert ipynb to pdf

If it dosn't work for any reason, you can try another way.
select File ? Print Preview and then on the preview
right click ? Print and then select save as pdf.

Copy rows from one Datatable to another DataTable?

As a result of the other posts, this is the shortest I could get:

DataTable destTable = sourceTable.Clone();
sourceTable.AsEnumerable().Where(row => /* condition */ ).ToList().ForEach(row => destTable.ImportRow(row));

How to get max value of a column using Entity Framework?

Or you can try this:

(From p In context.Persons Select p Order By age Descending).FirstOrDefault

For loop example in MySQL

drop table if exists foo;
create table foo
(
id int unsigned not null auto_increment primary key,
val smallint unsigned not null default 0
)
engine=innodb;

drop procedure if exists load_foo_test_data;

delimiter #
create procedure load_foo_test_data()
begin

declare v_max int unsigned default 1000;
declare v_counter int unsigned default 0;

  truncate table foo;
  start transaction;
  while v_counter < v_max do
    insert into foo (val) values ( floor(0 + (rand() * 65535)) );
    set v_counter=v_counter+1;
  end while;
  commit;
end #

delimiter ;

call load_foo_test_data();

select * from foo order by id;

Using "&times" word in html changes to ×

You need to escape:

<div class="test">&amp;times</div>

And then read the value using text() to get the unescaped value:

alert($(".test").text()); // outputs: &times

How to prevent favicon.ico requests?

You could use

<link rel="shortcut icon" href="http://localhost/" />

That way it won't actually be requested from the server.

commons httpclient - Adding query string parameters to GET/POST request

Here is how you would add query string parameters using HttpClient 4.2 and later:

URIBuilder builder = new URIBuilder("http://example.com/");
builder.setParameter("parts", "all").setParameter("action", "finish");

HttpPost post = new HttpPost(builder.build());

The resulting URI would look like:

http://example.com/?parts=all&action=finish

Is it possible to disable scrolling on a ViewPager

I found a simple solution.

//disable swiping
mViewPager.beginFakeDrag();

//enable swiping
mViewPager.endFakeDrag();

get next and previous day with PHP

Simply use this

echo date('Y-m-d',strtotime("yesterday"));
echo date('Y-m-d',strtotime("tomorrow"));

Effect of NOLOCK hint in SELECT statements

NOLOCK makes most SELECT statements faster, because of the lack of shared locks. Also, the lack of issuance of the locks means that writers will not be impeded by your SELECT.

NOLOCK is functionally equivalent to an isolation level of READ UNCOMMITTED. The main difference is that you can use NOLOCK on some tables but not others, if you choose. If you plan to use NOLOCK on all tables in a complex query, then using SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED is easier, because you don't have to apply the hint to every table.

Here is information about all of the isolation levels at your disposal, as well as table hints.

SET TRANSACTION ISOLATION LEVEL

Table Hint (Transact-SQL)

Use nginx to serve static files from subdirectories of a given directory

It should work, however http://nginx.org/en/docs/http/ngx_http_core_module.html#alias says:

When location matches the last part of the directive’s value: it is better to use the root directive instead:

which would yield:

server {
  listen        8080;
  server_name   www.mysite.com mysite.com;
  error_log     /home/www-data/logs/nginx_www.error.log;
  error_page    404    /404.html;

  location /public/doc/ {
    autoindex on;
    root  /home/www-data/mysite;
  } 

  location = /404.html {
    root /home/www-data/mysite/static/html;
  }       
}

Semaphore vs. Monitors - what's the difference?

A semaphore is a signaling mechanism used to coordinate between threads. Example: One thread is downloading files from the internet and another thread is analyzing the files. This is a classic producer/consumer scenario. The producer calls signal() on the semaphore when a file is downloaded. The consumer calls wait() on the same semaphore in order to be blocked until the signal indicates a file is ready. If the semaphore is already signaled when the consumer calls wait, the call does not block. Multiple threads can wait on a semaphore, but each signal will only unblock a single thread.

A counting semaphore keeps track of the number of signals. E.g. if the producer signals three times in a row, wait() can be called three times without blocking. A binary semaphore does not count but just have the "waiting" and "signalled" states.

A mutex (mutual exclusion lock) is a lock which is owned by a single thread. Only the thread which have acquired the lock can realease it again. Other threads which try to acquire the lock will be blocked until the current owner thread releases it. A mutex lock does not in itself lock anything - it is really just a flag. But code can check for ownership of a mutex lock to ensure that only one thread at a time can access some object or resource.

A monitor is a higher-level construct which uses an underlying mutex lock to ensure thread-safe access to some object. Unfortunately the word "monitor" is used in a few different meanings depending on context and platform and context, but in Java for example, a monitor is a mutex lock which is implicitly associated with an object, and which can be invoked with the synchronized keyword. The synchronized keyword can be applied to a class, method or block and ensures only one thread can execute the code at a time.

jquery loop on Json data using $.each

Have you converted your data from string to JavaScript object?

You can do it with data = eval('(' + string_data + ')'); or, which is safer, data = JSON.parse(string_data); but later will only works in FF 3.5 or if you include json2.js

jQuery since 1.4.1 also have function for that, $.parseJSON().

But actually, $.getJSON() should give you already parsed json object, so you should just check everything thoroughly, there is little mistake buried somewhere, like you might have forgotten to quote something in json, or one of the brackets is missing.

PostgreSQL ERROR: canceling statement due to conflict with recovery

There's no need to start idle transactions on the master. In postgresql-9.1 the most direct way to solve this problem is by setting

hot_standby_feedback = on

This will make the master aware of long-running queries. From the docs:

The first option is to set the parameter hot_standby_feedback, which prevents VACUUM from removing recently-dead rows and so cleanup conflicts do not occur.

Why isn't this the default? This parameter was added after the initial implementation and it's the only way that a standby can affect a master.

Erase the current printed console line

Just found this old thread, looking for some kind of escape sequence to blank the actual line.

It's quite funny no one came to the idea (or I have missed it) that printf returns the number of characters written. So just print '\r' + as many blank characters as printf returned and you will exactly blank the previuosly written text.

int BlankBytes(int Bytes)
{
                char strBlankStr[16];

                sprintf(strBlankStr, "\r%%%is\r", Bytes);
                printf(strBlankStr,"");

                return 0;
}

int main(void)
{
                int iBytesWritten;
                double lfSomeDouble = 150.0;

                iBytesWritten = printf("test text %lf", lfSomeDouble);

                BlankBytes(iBytesWritten);

                return 0;
}

As I cant use VT100, it seems I have to stick with that solution

Remove white space below image

I found this question and none of the solutions here worked for me. I found another solution that got rid of the gaps below images in Chrome. I had to add line-height:0; to the img selector in my CSS and the gaps below images went away.

Crazy that this problem persists in browsers in 2013.

Finding modified date of a file/folder

PowerShell code to find all document library files modified from last 2 days.

$web = Get-SPWeb -Identity http://siteName:9090/ 
        $list = $web.GetList("http://siteName:9090/Style Library/")
        $folderquery =  New-Object Microsoft.SharePoint.SPQuery  
        $foldercamlQuery =  
        '<Where>   <Eq> 
                <FieldRef Name="ContentType" />  <Value Type="text">Folder</Value> 
            </Eq> </Where>' 
        $folderquery.Query = $foldercamlQuery 
        $folders = $list.GetItems($folderquery) 
        foreach($folderItem in $folders) 
        { 
            $folder = $folderItem.Folder
            if($folder.ItemCount -gt 0){ 
            Write-Host " find Item count " $folder.ItemCount
                $oldest = $null
                $files = $folder.Files

                $date = (Get-Date).AddDays(-2).ToString(“MM/dd/yyyy”)
                foreach ($file in $files){ 
                    if($file.Item["Modified"]-Ge $date)
                    {
                        Write-Host "Last 2 days modified folder name:"   $folder   " File Name: "  $file.Item["Name"]   " Date of midified: "  $file.Item["Modified"] 
                    } 
                } 
            } 
            else
             { 
                Write-Warning "$folder['Name'] is empty" 
            } 
        }

git: diff between file in local repo and origin

I tried a couple of solution but I thing easy way like this (you are in the local folder):

#!/bin/bash
git fetch

var_local=`cat .git/refs/heads/master`
var_remote=`git log origin/master -1 | head -n1 | cut -d" " -f2`

if [ "$var_remote" = "$var_local" ]; then
    echo "Strings are equal." #1
else
    echo "Strings are not equal." #0 if you want
fi

Then you did compare local git and remote git last commit number....

How to retrieve the dimensions of a view?

ViewTreeObserver and onWindowFocusChanged() are not so necessary at all.

If you inflate the TextView as layout and/or put some content in it and set LayoutParams then you can use getMeasuredHeight() and getMeasuredWidth().

BUT you have to be careful with LinearLayouts (maybe also other ViewGroups). The issue there is, that you can get the width and height after onWindowFocusChanged() but if you try to add some views in it, then you can't get that information until everything have been drawn. I was trying to add multiple TextViews to LinearLayouts to mimic a FlowLayout (wrapping style) and so couldn't use Listeners. Once the process is started, it should continue synchronously. So in such case, you might want to keep the width in a variable to use it later, as during adding views to layout, you might need it.

How to use HTML to print header and footer on every printed page of a document?

If you are using a template engine like Asp.net Razor Engine or Angular, I think you must re-generate your page and split the page in several pages and then you can freely markup each page and put header and footer on theme. one example could be as bellow:

_x000D_
_x000D_
@page {_x000D_
  size: A4;  _x000D_
   margin: .9cm;_x000D_
}_x000D_
_x000D_
_x000D_
@media print {_x000D_
_x000D_
   body.print-paper-a4 {_x000D_
    width: 210mm;_x000D_
    height: 297mm;_x000D_
  }_x000D_
_x000D_
   body {_x000D_
       background: white;_x000D_
       margin: 0;_x000D_
       padding: 0;_x000D_
   }_x000D_
_x000D_
   .print-stage,_x000D_
   .no-print {_x000D_
       display: none;_x000D_
   }_x000D_
_x000D_
_x000D_
   body.print-paper.a4 .print-paper {_x000D_
      width: 210mm;_x000D_
        height: 297mm;_x000D_
    }_x000D_
_x000D_
   .print-paper {_x000D_
       page-break-after: always;_x000D_
       margin: 0;_x000D_
       padding: .8cm;_x000D_
       border:none;_x000D_
       overflow: hidden;_x000D_
   }_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
_x000D_
.print-papers {_x000D_
    display: block;_x000D_
    z-index: 2000;_x000D_
    margin: auto;_x000D_
_x000D_
}_x000D_
_x000D_
_x000D_
body.print-paper-a4 .print-paper {_x000D_
    width: 21cm;_x000D_
    height:27cm;_x000D_
}_x000D_
_x000D_
_x000D_
.print-paper {_x000D_
    margin: auto;_x000D_
    background: white;_x000D_
    border: 1px dotted black;_x000D_
    box-sizing: border-box;_x000D_
    margin: 1cm auto;_x000D_
    padding: .8cm;_x000D_
       overflow: hidden;   _x000D_
}_x000D_
_x000D_
_x000D_
body.print-mode .no-print-preview {_x000D_
    display: none;_x000D_
}_x000D_
_x000D_
body.print-mode .print-preview {_x000D_
    display: block;_x000D_
}
_x000D_
<body class="print-mode print-paper-a4">_x000D_
        _x000D_
        <div class="print-papers print-preview">_x000D_
            <div class="print-paper">_x000D_
                <div style="font-size: 5cm">_x000D_
                    HELLO_x000D_
                </div>_x000D_
_x000D_
            </div>_x000D_
            <div class="print-paper">_x000D_
              <div class="page-header">_x000D_
                </div>_x000D_
              _x000D_
              _x000D_
            </div>_x000D_
            <div class="print-paper">_x000D_
                _x000D_
                _x000D_
_x000D_
            </div>            _x000D_
        </div>_x000D_
  </body>
_x000D_
_x000D_
_x000D_

How to get the separate digits of an int number?

I wrote a program that demonstrates how to separate the digits of an integer using a more simple and understandable approach that does not involve arrays, recursions, and all that fancy schmancy. Here is my code:

int year = sc.nextInt(), temp = year, count = 0;

while (temp>0)
{
  count++;
  temp = temp / 10;
}

double num = Math.pow(10, count-1);
int i = (int)num;

for (;i>0;i/=10)
{
  System.out.println(year/i%10);
}

Suppose your input is the integer 123, the resulting output will be as follows:

1
2
3

ORA-00907: missing right parenthesis

Firstly, in histories_T, you are referencing table T_customer (should be T_customers) and secondly, you are missing the FOREIGN KEY clause that REFERENCES orders; which is not being created (or dropped) with the code you provided.

There may be additional errors as well, and I admit Oracle has never been very good at describing the cause of errors - "Mutating Tables" is a case in point.

Let me know if there additional problems you are missing.

How to make a simple image upload using Javascript/HTML

<li class="list-group-item active"><h5>Feaured Image</h5></li>
            <li class="list-group-item">
                <div class="input-group mb-3">
                    <div class="custom-file ">
                        <input type="file"  class="custom-file-input" name="thumbnail" id="thumbnail">
                        <label class="custom-file-label" for="thumbnail">Choose file</label>
                    </div>
                </div>
                <div class="img-thumbnail  text-center">
                    <img src="@if(isset($product)) {{asset('storage/'.$product->thumbnail)}} @else {{asset('images/no-thumbnail.jpeg')}} @endif" id="imgthumbnail" class="img-fluid" alt="">
                </div>
            </li>
<script>
$(function(){
$('#thumbnail').on('change', function() {
    var file = $(this).get(0).files;
    var reader = new FileReader();
    reader.readAsDataURL(file[0]);
    reader.addEventListener("load", function(e) {
    var image = e.target.result;
$("#imgthumbnail").attr('src', image);
});
});
}
</script>

How can I check if a jQuery plugin is loaded?

jQuery has a method to check if something is a function

if ($.isFunction($.fn.dateJS)) {
    //your code using the plugin
}

API reference: https://api.jquery.com/jQuery.isFunction/

How to create jar file with package structure?

From the directory containing the com folder:

$ jar cvf asd.jar com
added manifest
adding: com/(in = 0) (out= 0)(stored 0%)
adding: com/cdy/(in = 0) (out= 0)(stored 0%)
adding: com/cdy/ws/(in = 0) (out= 0)(stored 0%)
adding: com/cdy/ws/a.class(in = 0) (out= 0)(stored 0%)
adding: com/cdy/ws/b.class(in = 0) (out= 0)(stored 0%)
adding: com/cdy/ws/c.class(in = 0) (out= 0)(stored 0%)

$ jar -tf asd.jar 
META-INF/
META-INF/MANIFEST.MF
com/
com/cdy/
com/cdy/ws/
com/cdy/ws/a.class
com/cdy/ws/b.class
com/cdy/ws/c.class

Execute php file from another php

Sounds like you're trying to execute the PHP code directly in your shell. Your shell doesn't speak PHP, so it interprets your PHP code as though it's in your shell's native language, as though you had literally run <?php at the command line.

Shell scripts usually start with a "shebang" line that tells the shell what program to use to interpret the file. Begin your file like this:

#!/usr/bin/env php
<?php
//Connection
function connection () {

Besides that, the string you're passing to exec doesn't make any sense. It starts with a slash all by itself, it uses too many periods in the path, and it has a stray right parenthesis.

Copy the contents of the command string and paste them at your command line. If it doesn't run there, then exec probably won't be able to run it, either.

Another option is to change the command you execute. Instead of running the script directly, run php and pass your script as an argument. Then you shouldn't need the shebang line.

exec('php name.php');

What is the default boolean value in C#?

The default value is indeed false.

However you can't use a local variable is it's not been assigned first.

You can use the default keyword to verify:

bool foo = default(bool);
if (!foo) { Console.WriteLine("Default is false"); }

When to use 'raise NotImplementedError'?

Consider if instead it was:

class RectangularRoom(object):
    def __init__(self, width, height):
        pass

    def cleanTileAtPosition(self, pos):
        pass

    def isTileCleaned(self, m, n):
        pass

and you subclass and forget to tell it how to isTileCleaned() or, perhaps more likely, typo it as isTileCLeaned(). Then in your code, you'll get a None when you call it.

  • Will you get the overridden function you wanted? Definitely not.
  • Is None valid output? Who knows.
  • Is that intended behavior? Almost certainly not.
  • Will you get an error? It depends.

raise NotImplmentedError forces you to implement it, as it will throw an exception when you try to run it until you do so. This removes a lot of silent errors. It's similar to why a bare except is almost never a good idea: because people make mistakes and this makes sure they aren't swept under the rug.

Note: Using an abstract base class, as other answers have mentioned, is better still, as then the errors are frontloaded and the program won't run until you implement them (with NotImplementedError, it will only throw an exception if actually called).

How to get the azure account tenant Id?

As of now (06/07/2018), an easy approach would be running az account show in the Azure Cloud Shell (requires a Storage Account) in the Azure Portal.

--- Command ---

az account show

--- Command Output ---

{
  "environmentName": "AzureCloud",
  "id": "{Subscription Id (GUID)}",
  "isDefault": true,
  "name": "{Subscription Name}",
  "state": "Enabled",
  "tenantId": "{Tenant Id (GUID)}",
  "user": {
    "cloudShellID": true,
    "name": "{User email}",
    "type": "user"
  }
}

Find more details on Azure Cloud Shell at https://docs.microsoft.com/en-us/azure/cloud-shell/overview.

How do I escape a reserved word in Oracle?

you have to rename the column to an other name because TABLE is reserved by Oracle.

You can see all reserved words of Oracle in the oracle view V$RESERVED_WORDS.

Run exe file with parameters in a batch file

If you need to see the output of the execute, use CALL together with or instead of START.

Example:

CALL "C:\Program Files\Certain Directory\file.exe" -param PAUSE

This will run the file.exe and print back whatever it outputs, in the same command window. Remember the PAUSE after the call or else the window may close instantly.

How to remove commits from a pull request

This is what helped me:

  1. Create a new branch with the existing one. Let's call the existing one branch_old and new as branch_new.

  2. Reset branch_new to a stable state, when you did not have any problem commit at all. For example, to put it at your local master's level do the following:

    git reset —hard master git push —force origin

  3. cherry-pick the commits from branch_old into branch_new

  4. git push

Convert txt to csv python script

I suposse this is the output you need:

title,intro,tagline

2.9,Gardena,CA

It can be done with this changes to your code:

import csv
import itertools

with open('log.txt', 'r') as in_file:
    lines = in_file.read().splitlines()
    stripped = [line.replace(","," ").split() for line in lines]
    grouped = itertools.izip(*[stripped]*1)
    with open('log.csv', 'w') as out_file:
        writer = csv.writer(out_file)
        writer.writerow(('title', 'intro', 'tagline'))
        for group in grouped:
            writer.writerows(group)

Excel how to fill all selected blank cells with text

If you want to do this in VBA, then this is a shorter method:

Sub FillBlanksWithNull()

'This macro will fill all "blank" cells with the text "Null"

'When no range is selected, it starts at A1 until the last used row/column

'When a range is selected prior, only the blank cell in the range will be used.

On Error GoTo ErrHandler:

Selection.SpecialCells(xlCellTypeBlanks).FormulaR1C1 = "Null"

Exit Sub

ErrHandler:

MsgBox "No blank cells found", vbDefaultButton1, Error

Resume Next

End Sub

Regards,

Robert Ilbrink

SharePoint 2013 get current user using JavaScript

you can use below function if you know the id of the user:

function getUser(id){
var returnValue;
jQuery.ajax({
 url: "http://YourSite/_api/Web/GetUserById(" + id + ")",
 type: "GET",
 headers: { "Accept": "application/json;odata=verbose" },
 success: function(data) {
       var dataResults = data.d;
       alert(dataResults.Title);
  }
});
}

or you can try

var listURL = _spPageContextInfo.webAbsoluteUrl + "/_api/web/currentuser";

Cannot delete or update a parent row: a foreign key constraint fails

I think that your foreign key is backwards. Try:

ALTER TABLE 'jobs'
ADD CONSTRAINT `advertisers_ibfk_1` FOREIGN KEY (`advertiser_id`) REFERENCES `advertisers` (`advertiser_id`)

javascript remove "disabled" attribute from html input

To set the disabled to false using the name property of the input:

document.myForm.myInputName.disabled = false;

Fetch: POST json data

If your JSON payload contains arrays and nested objects, I would use URLSearchParams and jQuery's param() method.

fetch('/somewhere', {
  method: 'POST',
  body: new URLSearchParams($.param(payload))
})

To your server, this will look like a standard HTML <form> being POSTed.

How do you write multiline strings in Go?

For me this is what I use if adding \n is not a problem.

fmt.Sprintf("Hello World\nHow are you doing today\nHope all is well with your go\nAnd code")

Else you can use the raw string

multiline := `Hello Brothers and sisters of the Code
              The grail needs us.
             `

Makefile If-Then Else and Loops

Conditional Forms

Simple

conditional-directive
text-if-true
endif

Moderately Complex

conditional-directive
text-if-true
else
text-if-false
endif

More Complex

conditional-directive
text-if-one-is-true
else
conditional-directive
text-if-true
else
text-if-false
endif
endif

Conditional Directives

If Equal Syntax

ifeq (arg1, arg2)
ifeq 'arg1' 'arg2'
ifeq "arg1" "arg2"
ifeq "arg1" 'arg2'
ifeq 'arg1' "arg2"

If Not Equal Syntax

ifneq (arg1, arg2)
ifneq 'arg1' 'arg2'
ifneq "arg1" "arg2"
ifneq "arg1" 'arg2'
ifneq 'arg1' "arg2"

If Defined Syntax

ifdef variable-name

If Not Defined Syntax

ifndef variable-name  

foreach Function

foreach Function Syntax

$(foreach var, list, text)  

foreach Semantics
For each whitespace separated word in "list", the variable named by "var" is set to that word and text is executed.

PostgreSQL: insert from another table

Very late answer, but I think my answer is more straight forward for specific use cases where users want to simply insert (copy) data from table A into table B:

INSERT INTO table_b (col1, col2, col3, col4, col5, col6)
SELECT col1, 'str_val', int_val, col4, col5, col6
FROM table_a

Replace Div Content onclick

A Third Answer

Sorry, maybe I have it correct this time...

jsFiddle Demo

var savedBox1, savedBox2, state1=0, state2=0;

jQuery(document).ready(function() {
    jQuery(".rec1").click(function() {
        if (state1==0){
            savedBox1 = jQuery('#rec-box').html();
            jQuery('#rec-box').html(jQuery(this).next().html()); 
            state1 = 1;
        }else{
            jQuery('#rec-box').html(savedBox1); 
            state1 = 0;
        }
    });

    jQuery(".rec2").click(function() {
        if (state1==0){
            savedBox2 = jQuery('#rec-box2').html();
            jQuery('#rec-box2').html(jQuery(this).next().html()); 
            state2 = 1;
        }else{
            jQuery('#rec-box2').html(savedBox2); 
            state2 = 0;
        }
    });
});

m2e error in MavenArchiver.getManifest()

I had also faced the same issue and it got resolved by changing the version from 3.2.0 to 2.6 as shown in below pom.xml snippet

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.6</version>
    <configuration>
        <warSourceDirectory>src/main/webapp</warSourceDirectory>
        <warName>Spring4MVC</warName>
        <failOnMissingWebXml>false</failOnMissingWebXml>
    </configuration>
</plugin>

Adding a column after another column within SQL

In a Firebird database the AFTER myOtherColumn does not work but you can try re-positioning the column using:

ALTER TABLE name ALTER column POSITION new_position

I guess it may work in other cases as well.

How to 'insert if not exists' in MySQL?

Solution:

INSERT INTO `table` (`value1`, `value2`) 
SELECT 'stuff for value1', 'stuff for value2' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `table` 
      WHERE `value1`='stuff for value1' AND `value2`='stuff for value2' LIMIT 1) 

Explanation:

The innermost query

SELECT * FROM `table` 
      WHERE `value1`='stuff for value1' AND `value2`='stuff for value2' LIMIT 1

used as the WHERE NOT EXISTS-condition detects if there already exists a row with the data to be inserted. After one row of this kind is found, the query may stop, hence the LIMIT 1 (micro-optimization, may be omitted).

The intermediate query

SELECT 'stuff for value1', 'stuff for value2' FROM DUAL

represents the values to be inserted. DUAL refers to a special one row, one column table present by default in all Oracle databases (see https://en.wikipedia.org/wiki/DUAL_table). On a MySQL-Server version 5.7.26 I got a valid query when omitting FROM DUAL, but older versions (like 5.5.60) seem to require the FROM information. By using WHERE NOT EXISTS the intermediate query returns an empty result set if the innermost query found matching data.

The outer query

INSERT INTO `table` (`value1`, `value2`) 

inserts the data, if any is returned by the intermediate query.

Bootstrap 3 grid with no gap

The more powerful (and 100% fluid) Bootstrap 3 grid now comes in 3 sizes. Tiny (for smartphones .col-), Small (for tablets .col-sm-) and Large (for laptops/desktops .col-lg-*). The 3 grid sizes enable you to control grid behavior on different devices (desktop, tablet, smartphone, etc..).

Unlike 2.x, Bootstrap 3 does not provide a fixed (pixel-based) grid. While a fixed-width layout can still be acheived using a simple custom wrapper, there is now only one percentage-based (fluid) grid. The .container and .row classes are now fluid by default, so don't use .row-fluid or .container-fluid anymore in your 3.x markup.

Source

How can I get the actual video URL of a YouTube live stream?

You need to get the HLS m3u8 playlist files from the video's manifest. There are ways to do this by hand, but for simplicity I'll be using the youtube-dl tool to get this information. I'll be using this live stream as an example: https://www.youtube.com/watch?v=_Gtc-GtLlTk

First, get the formats of the video:

?  ~ youtube-dl --list-formats https://www.youtube.com/watch\?v\=_Gtc-GtLlTk
[youtube] _Gtc-GtLlTk: Downloading webpage
[youtube] _Gtc-GtLlTk: Downloading video info webpage
[youtube] Downloading multifeed video (_Gtc-GtLlTk, aflWCT1tYL0) - add --no-playlist to just download video _Gtc-GtLlTk
[download] Downloading playlist: Southwest Florida Eagle Cam
[youtube] playlist Southwest Florida Eagle Cam: Collected 2 video ids (downloading 2 of them)
[download] Downloading video 1 of 2
[youtube] _Gtc-GtLlTk: Downloading webpage
[youtube] _Gtc-GtLlTk: Downloading video info webpage
[youtube] _Gtc-GtLlTk: Extracting video information
[youtube] _Gtc-GtLlTk: Downloading formats manifest
[youtube] _Gtc-GtLlTk: Downloading DASH manifest
[info] Available formats for _Gtc-GtLlTk:
format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, mp4a.40.2@128k (48000Hz)
160          mp4        256x144    DASH video  124k , avc1.42c00b, 30fps, video only
133          mp4        426x240    DASH video  258k , avc1.4d4015, 30fps, video only
134          mp4        640x360    DASH video  646k , avc1.4d401e, 30fps, video only
135          mp4        854x480    DASH video 1171k , avc1.4d401f, 30fps, video only
136          mp4        1280x720   DASH video 2326k , avc1.4d401f, 30fps, video only
137          mp4        1920x1080  DASH video 4347k , avc1.640028, 30fps, video only
151          mp4        72p        HLS , h264, aac  @ 24k
132          mp4        240p       HLS , h264, aac  @ 48k
92           mp4        240p       HLS , h264, aac  @ 48k
93           mp4        360p       HLS , h264, aac  @128k
94           mp4        480p       HLS , h264, aac  @128k
95           mp4        720p       HLS , h264, aac  @256k
96           mp4        1080p      HLS , h264, aac  @256k (best)
[download] Downloading video 2 of 2
[youtube] aflWCT1tYL0: Downloading webpage
[youtube] aflWCT1tYL0: Downloading video info webpage
[youtube] aflWCT1tYL0: Extracting video information
[youtube] aflWCT1tYL0: Downloading formats manifest
[youtube] aflWCT1tYL0: Downloading DASH manifest
[info] Available formats for aflWCT1tYL0:
format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, mp4a.40.2@128k (48000Hz)
160          mp4        256x144    DASH video  124k , avc1.42c00b, 30fps, video only
133          mp4        426x240    DASH video  258k , avc1.4d4015, 30fps, video only
134          mp4        640x360    DASH video  646k , avc1.4d401e, 30fps, video only
135          mp4        854x480    DASH video 1171k , avc1.4d401f, 30fps, video only
136          mp4        1280x720   DASH video 2326k , avc1.4d401f, 30fps, video only
151          mp4        72p        HLS , h264, aac  @ 24k
132          mp4        240p       HLS , h264, aac  @ 48k
92           mp4        240p       HLS , h264, aac  @ 48k
93           mp4        360p       HLS , h264, aac  @128k
94           mp4        480p       HLS , h264, aac  @128k
95           mp4        720p       HLS , h264, aac  @256k (best)
[download] Finished downloading playlist: Southwest Florida Eagle Cam

In this case, there are two videos because the live stream contains two cameras. From here, we need to get the HLS URL for a specific stream. Use -f to pass in the format you would like to watch, and -g to get that stream's URL:

?  ~ youtube-dl -f 95 -g https://www.youtube.com/watch\?v\=_Gtc-GtLlTk
https://manifest.googlevideo.com/api/manifest/hls_playlist/id/_Gtc-GtLlTk.2/itag/95/source/yt_live_broadcast/requiressl/yes/ratebypass/yes/live/1/cmbypass/yes/gir/yes/dg_shard/X0d0Yy1HdExsVGsuMg.95/hls_chunk_host/r1---sn-ab5l6ne6.googlevideo.com/playlist_type/LIVE/gcr/us/pmbypass/yes/mm/32/mn/sn-ab5l6ne6/ms/lv/mv/m/pl/20/dover/3/sver/3/fexp/9408495,9410706,9416126,9418581,9420452,9422596,9422780,9423059,9423661,9423662,9425349,9425959,9426661,9426720,9427325,9428422,9429306/upn/xmL7zNht848/mt/1456412649/ip/64.125.177.124/ipbits/0/expire/1456434315/sparams/ip,ipbits,expire,id,itag,source,requiressl,ratebypass,live,cmbypass,gir,dg_shard,hls_chunk_host,playlist_type,gcr,pmbypass,mm,mn,ms,mv,pl/signature/7E48A727654105FF82E158154FCBA7569D52521B.1FA117183C664F00B7508DDB81274644F520C27F/key/dg_yt0/playlist/index.m3u8
https://manifest.googlevideo.com/api/manifest/hls_playlist/id/aflWCT1tYL0.2/itag/95/source/yt_live_broadcast/requiressl/yes/ratebypass/yes/live/1/cmbypass/yes/gir/yes/dg_shard/YWZsV0NUMXRZTDAuMg.95/hls_chunk_host/r13---sn-ab5l6n7y.googlevideo.com/pmbypass/yes/playlist_type/LIVE/gcr/us/mm/32/mn/sn-ab5l6n7y/ms/lv/mv/m/pl/20/dover/3/sver/3/upn/vdBkD9lrq8Q/fexp/9408495,9410706,9416126,9418581,9420452,9422596,9422780,9423059,9423661,9423662,9425349,9425959,9426661,9426720,9427325,9428422,9429306/mt/1456412649/ip/64.125.177.124/ipbits/0/expire/1456434316/sparams/ip,ipbits,expire,id,itag,source,requiressl,ratebypass,live,cmbypass,gir,dg_shard,hls_chunk_host,pmbypass,playlist_type,gcr,mm,mn,ms,mv,pl/signature/4E83CD2DB23C2331CE349CE9AFE806C8293A01ED.880FD2E253FAC8FA56FAA304C78BD1D62F9D22B4/key/dg_yt0/playlist/index.m3u8

These are your HLS m3u8 playlists, one for each camera associated with the live stream.

Without youtube-dl, your flow might look like this:

Take your video id and make a GET request to the get_video_info endpoint:

HTTP GET: https://www.youtube.com/get_video_info?&video_id=_Gtc-GtLlTk&el=info&ps=default&eurl=&gl=US&hl=en

In the response, the hlsvp value will be the link to the m3u8 HLS playlist:

https://manifest.googlevideo.com/api/manifest/hls_variant/maudio/1/ipbits/0/key/yt6/ip/64.125.177.124/gcr/us/source/yt_live_broadcast/upn/BYS1YGuQtYI/id/_Gtc-GtLlTk.2/fexp/9416126%2C9416984%2C9417367%2C9420452%2C9422596%2C9423039%2C9423661%2C9423662%2C9423923%2C9425346%2C9427672%2C9428946%2C9429162/sparams/gcr%2Cid%2Cip%2Cipbits%2Citag%2Cmaudio%2Cplaylist_type%2Cpmbypass%2Csource%2Cexpire/sver/3/expire/1456449859/pmbypass/yes/playlist_type/LIVE/itag/0/signature/1E6874232CCAC397B601051699A03DC5A32F66D9.1CABCD9BFC87A2A886A29B86CF877077DD1AEEAA/file/index.m3u8

Difference between e.target and e.currentTarget

  • e.target is element, which you f.e. click
  • e.currentTarget is element with added event listener.

If you click on child element of button, its better to use currentTarget to detect buttons attributes, in CH its sometimes problem to use e.target.

Can't create handler inside thread that has not called Looper.prepare()

Java 8

new Handler(Looper.getMainLooper()).post(() -> {
    // Work in the UI thread

}; 

Kotlin

Handler(Looper.getMainLooper()).post{
    // Work in the UI thread
}

GL

sqlalchemy filter multiple columns

You can use SQLAlchemy's or_ function to search in more than one column (the underscore is necessary to distinguish it from Python's own or).

Here's an example:

from sqlalchemy import or_
query = meta.Session.query(User).filter(or_(User.firstname.like(searchVar),
                                            User.lastname.like(searchVar)))

Check free disk space for current partition in bash

df --output=avail -B 1 "$PWD" |tail -n 1

you get size in bytes this way.

Why doesn't Java offer operator overloading?

Alternatives to Native Support of Java Operator Overloading

Since Java doesn't have operator overloading, here are some alternatives you can look into:

  1. Use another language. Both Groovy and Scala have operator overloading, and are based on Java.
  2. Use java-oo, a plugin that enables operator overloading in Java. Note that it is NOT platform independent. Also, it has many issues, and is not compatible with the latest releases of Java (i.e. Java 10). (Original StackOverflow Source)
  3. Use JNI, Java Native Interface, or alternatives. This allows you to write C or C++ (maybe others?) methods for use in Java. Of course this is also NOT platform independent.

If anyone is aware of others, please comment, and I will add it to this list.

Is there a standard function to check for null, undefined, or blank variables in JavaScript?

It may be usefull.

All values in array represent what you want to be (null, undefined or another things) and you search what you want in it.

var variablesWhatILookFor = [null, undefined, ''];
variablesWhatILookFor.indexOf(document.DocumentNumberLabel) > -1

What does functools.wraps do?

When you use a decorator, you're replacing one function with another. In other words, if you have a decorator

def logged(func):
    def with_logging(*args, **kwargs):
        print(func.__name__ + " was called")
        return func(*args, **kwargs)
    return with_logging

then when you say

@logged
def f(x):
   """does some math"""
   return x + x * x

it's exactly the same as saying

def f(x):
    """does some math"""
    return x + x * x
f = logged(f)

and your function f is replaced with the function with_logging. Unfortunately, this means that if you then say

print(f.__name__)

it will print with_logging because that's the name of your new function. In fact, if you look at the docstring for f, it will be blank because with_logging has no docstring, and so the docstring you wrote won't be there anymore. Also, if you look at the pydoc result for that function, it won't be listed as taking one argument x; instead it'll be listed as taking *args and **kwargs because that's what with_logging takes.

If using a decorator always meant losing this information about a function, it would be a serious problem. That's why we have functools.wraps. This takes a function used in a decorator and adds the functionality of copying over the function name, docstring, arguments list, etc. And since wraps is itself a decorator, the following code does the correct thing:

from functools import wraps
def logged(func):
    @wraps(func)
    def with_logging(*args, **kwargs):
        print(func.__name__ + " was called")
        return func(*args, **kwargs)
    return with_logging

@logged
def f(x):
   """does some math"""
   return x + x * x

print(f.__name__)  # prints 'f'
print(f.__doc__)   # prints 'does some math'

Django: Calling .update() on a single model instance retrieved by .get()?

Here's a mixin that you can mix into any model class which gives each instance an update method:

class UpdateMixin(object):
    def update(self, **kwargs):
        if self._state.adding:
            raise self.DoesNotExist
        for field, value in kwargs.items():
            setattr(self, field, value)
        self.save(update_fields=kwargs.keys())

The self._state.adding check checks to see if the model is saved to the database, and if not, raises an error.

(Note: This update method is for when you want to update a model and you know the instance is already saved to the database, directly answering the original question. The built-in update_or_create method featured in Platinum Azure's answer already covers the other use-case.)

You would use it like this (after mixing this into your user model):

user = request.user
user.update(favorite_food="ramen")

Besides having a nicer API, another advantage to this approach is that it calls the pre_save and post_save hooks, while still avoiding atomicity issues if another process is updating the same model.

How to import/include a CSS file using PHP code and not HTML code?

_trace its directory, I guess

echo css('lib/datatables_rqs/jquery.dataTables.css');

Converting a date in MySQL from string field

Yes, there's str_to_date

mysql> select str_to_date("03/02/2009","%d/%m/%Y");
+--------------------------------------+
| str_to_date("03/02/2009","%d/%m/%Y") |
+--------------------------------------+
| 2009-02-03                           |
+--------------------------------------+
1 row in set (0.00 sec)

Why does JS code "var a = document.querySelector('a[data-a=1]');" cause error?

Yes strings must be quoted and in some cases like in applescript, quotes must be escaped

do JavaScript "document.querySelector('span[" & attrName & "=\"" & attrValue & "\"]').click();"

How do I shrink my SQL Server Database?

You also have to modify the minimum size of the data and log files. DBCC SHRINKDATABASE will shrink the data inside the files you already have allocated. To shrink a file to a size smaller than its minimum size, use DBCC SHRINKFILE and specify the new size.

What is Node.js?

Also, do not forget to mention that Google's V8 is VERY fast. It actually converts the JavaScript code to machine code with the matched performance of compiled binary. So along with all the other great things, it's INSANELY fast.

Split Java String by New Line

Maybe this would work:

Remove the double backslashes from the parameter of the split method:

split = docStr.split("\n");

Retrieving the COM class factory for component with CLSID {XXXX} failed due to the following error: 80040154

I had the same issue, but the other answers only supplied one part of the solution.

The solution is two fold:

Remove the 64bit from the Register.

  • c:\windows\system32\regsvr32.exe /U <file.dll>
  • This will not remove references to other copied of the dll in other folders.

or

  • Find the key called HKEY_CLASSES_ROOT\CLSID{......}\InprocServer32. This key will have the filename of the DLL as its default value.
  • I removed the HKEY_CLASSES_ROOT\CLSID{......} folder.

Register it as 32bit:

  • C:\Windows\SysWOW64\regsvr32 <file.dll>

Registering it as 32bit without removing the 64bit registration does not resolve my issue.

How to check if internet connection is present in Java?

URL url=new URL("http://[any domain]");
URLConnection con=url.openConnection();

/*now errors WILL arise here, i hav tried myself and it always shows "connected" so we'll open an InputStream on the connection, this way we know for sure that we're connected to d internet */

/* Get input stream */
con.getInputStream();

Put the above statements in try catch blocks and if an exception in caught means that there's no internet connection established. :-)

Paste in insert mode?

No not directly. What you can do though is quickly exit insert mode for a single normal mode operation with Ctrl-O and then paste from there which will end by putting you back in insert mode.

Key Combo: Ctrl-O p

EDIT: Interesting. It does appear that there is a way as several other people have listed.

SQLite add Primary Key

You can't modify SQLite tables in any significant way after they have been created. The accepted suggested solution is to create a new table with the correct requirements and copy your data into it, then drop the old table.

here is the official documentation about this: http://sqlite.org/faq.html#q11

Printing an array in C++?

C++ can print whatever you want if you program it to do so. You'll have to go through the array yourself printing each element.

The difference between the Runnable and Callable interfaces in Java

As it was already mentioned here Callable is relatively new interface and it was introduced as a part of concurrency package. Both Callable and Runnable can be used with executors. Class Thread (that implements Runnable itself) supports Runnable only.

You can still use Runnable with executors. The advantage of Callable that you can send it to executor and immediately get back Future result that will be updated when the execution is finished. The same may be implemented with Runnable, but in this case you have to manage the results yourself. For example you can create results queue that will hold all results. Other thread can wait on this queue and deal with results that arrive.

Java: splitting the filename into a base and extension

http://docs.oracle.com/javase/6/docs/api/java/io/File.html#getName()

From http://www.xinotes.org/notes/note/774/ :

Java has built-in functions to get the basename and dirname for a given file path, but the function names are not so self-apparent.

import java.io.File;

public class JavaFileDirNameBaseName {
    public static void main(String[] args) {
    File theFile = new File("../foo/bar/baz.txt");
    System.out.println("Dirname: " + theFile.getParent());
    System.out.println("Basename: " + theFile.getName());
    }
}

Hour from DateTime? in 24 hours format

date.ToString("HH:mm:ss"); // for 24hr format
date.ToString("hh:mm:ss"); // for 12hr format, it shows AM/PM

Refer this link for other Formatters in DateTime.

How do you get current active/default Environment profile programmatically in Spring?

Seems there is some demand to be able to access this statically.

How can I get such thing in static methods in non-spring-managed classes? – Aetherus

It's a hack, but you can write your own class to expose it. You must be careful to ensure that nothing will call SpringContext.getEnvironment() before all beans have been created, since there is no guarantee when this component will be instantiated.

@Component
public class SpringContext
{
    private static Environment environment;

    public SpringContext(Environment environment) {
        SpringContext.environment = environment;
    }

    public static Environment getEnvironment() {
        if (environment == null) {
            throw new RuntimeException("Environment has not been set yet");
        }
        return environment;
    }
}

Run jar file in command prompt

java [any other JVM options you need to give it] -jar foo.jar

How to call another components function in angular2

You can access component one's method from component two..

componentOne

  ngOnInit() {}

  public testCall(){
    alert("I am here..");    
  }

componentTwo

import { oneComponent } from '../one.component';


@Component({
  providers:[oneComponent ],
  selector: 'app-two',
  templateUrl: ...
}


constructor(private comp: oneComponent ) { }

public callMe(): void {
    this.comp.testCall();
  }

componentTwo html file

<button (click)="callMe()">click</button>

rewrite a folder name using .htaccess

mod_rewrite can only rewrite/redirect requested URIs. So you would need to request /apple/… to get it rewritten to a corresponding /folder1/….

Try this:

RewriteEngine on
RewriteRule ^apple/(.*) folder1/$1

This rule will rewrite every request that starts with the URI path /apple/… internally to /folder1/….


Edit    As you are actually looking for the other way round:

RewriteCond %{THE_REQUEST} ^GET\ /folder1/
RewriteRule ^folder1/(.*) /apple/$1 [L,R=301]

This rule is designed to work together with the other rule above. Requests of /folder1/… will be redirected externally to /apple/… and requests of /apple/… will then be rewritten internally back to /folder1/….

Cast Int to enum in Java

You can try like this.
Create Class with element id.

      public Enum MyEnum {
        THIS(5),
        THAT(16),
        THE_OTHER(35);

        private int id; // Could be other data type besides int
        private MyEnum(int id) {
            this.id = id;
        }

        public static MyEnum fromId(int id) {
                for (MyEnum type : values()) {
                    if (type.getId() == id) {
                        return type;
                    }
                }
                return null;
            }
      }

Now Fetch this Enum using id as int.

MyEnum myEnum = MyEnum.fromId(5);

Difference in boto3 between resource, client, and session?

Here's some more detailed information on what Client, Resource, and Session are all about.

Client:

  • low-level AWS service access
  • generated from AWS service description
  • exposes botocore client to the developer
  • typically maps 1:1 with the AWS service API
  • all AWS service operations are supported by clients
  • snake-cased method names (e.g. ListBuckets API => list_buckets method)

Here's an example of client-level access to an S3 bucket's objects (at most 1000**):

import boto3

client = boto3.client('s3')
response = client.list_objects_v2(Bucket='mybucket')
for content in response['Contents']:
    obj_dict = client.get_object(Bucket='mybucket', Key=content['Key'])
    print(content['Key'], obj_dict['LastModified'])

** you would have to use a paginator, or implement your own loop, calling list_objects() repeatedly with a continuation marker if there were more than 1000.

Resource:

  • higher-level, object-oriented API
  • generated from resource description
  • uses identifiers and attributes
  • has actions (operations on resources)
  • exposes subresources and collections of AWS resources
  • does not provide 100% API coverage of AWS services

Here's the equivalent example using resource-level access to an S3 bucket's objects (all):

import boto3

s3 = boto3.resource('s3')
bucket = s3.Bucket('mybucket')
for obj in bucket.objects.all():
    print(obj.key, obj.last_modified)

Note that in this case you do not have to make a second API call to get the objects; they're available to you as a collection on the bucket. These collections of subresources are lazily-loaded.

You can see that the Resource version of the code is much simpler, more compact, and has more capability (it does pagination for you). The Client version of the code would actually be more complicated than shown above if you wanted to include pagination.

Session:

  • stores configuration information (primarily credentials and selected region)
  • allows you to create service clients and resources
  • boto3 creates a default session for you when needed

A useful resource to learn more about these boto3 concepts is the introductory re:Invent video.

How to set up a cron job to run an executable every hour?

0 * * * * cd folder_containing_exe && ./exe_name

should work unless there is something else that needs to be setup for the program to run.

const to Non-const Conversion in C++

Leaving this here for myself,

If I get this error, I probably used const char* when I should be using char* const.

This makes the pointer constant, and not the contents of the string.

const char* const makes it so the value and the pointer is constant also.

Visual Studio Code cannot detect installed git

I had this problem after upgrading to macOS Catalina.

The issue is resolved as follows:

1. Find git location from the terminal:

which git

2. Add the location of git in settings file with your location:

settings.json

"git.path": "/usr/local/bin/git",

Depending on your platform, the user settings file (settings.json) is located here:

Windows %APPDATA%\Code\User\settings.json

macOS $HOME/Library/Application Support/Code/User/settings.json

Linux $HOME/.config/Code/User/settings.json

Drop all duplicate rows across multiple columns in Python Pandas

This is much easier in pandas now with drop_duplicates and the keep parameter.

import pandas as pd
df = pd.DataFrame({"A":["foo", "foo", "foo", "bar"], "B":[0,1,1,1], "C":["A","A","B","A"]})
df.drop_duplicates(subset=['A', 'C'], keep=False)

How to convert MySQL time to UNIX timestamp using PHP?

From one of my other posts, getting a unixtimestamp:

$unixTimestamp = time();

Converting to mysql datetime format:

$mysqlTimestamp = date("Y-m-d H:i:s", $unixTimestamp);

Getting some mysql timestamp:

$mysqlTimestamp = '2013-01-10 12:13:37';

Converting it to a unixtimestamp:

$unixTimestamp = strtotime('2010-05-17 19:13:37');

...comparing it with one or a range of times, to see if the user entered a realistic time:

if($unixTimestamp > strtotime("1999-12-15") && $unixTimestamp < strtotime("2025-12-15"))
{...}

Unix timestamps are safer too. You can do the following to check if a url passed variable is valid, before checking (for example) the previous range check:

if(ctype_digit($_GET["UpdateTimestamp"]))
{...}

how to query for a list<String> in jdbctemplate

You can't use placeholders for column names, table names, data type names, or basically anything that isn't data.

onActivityResult is not being called in Fragment

If the above problem is faced at Facebook login then you can use the below code in a parent activity of your fragment like:

Fragment fragment = getFragmentManager().findFragmentById(android.R.id.tabcontent);
fragment.onActivityResult(requestCode, resultCode, data);

Or:

Fragment fragment = getFragmentManager().findFragmentById("fragment id here");
fragment.onActivityResult(requestCode, resultCode, data);

And add the below call in your fragment...

callbackManager.onActivityResult(requestCode, resultCode, data);

What exactly does stringstream do?

To answer the question. stringstream basically allows you to treat a string object like a stream, and use all stream functions and operators on it.

I saw it used mainly for the formatted output/input goodness.

One good example would be c++ implementation of converting number to stream object.

Possible example:

template <class T>
string num2str(const T& num, unsigned int prec = 12) {
    string ret;
    stringstream ss;
    ios_base::fmtflags ff = ss.flags();
    ff |= ios_base::floatfield;
    ff |= ios_base::fixed;
    ss.flags(ff);
    ss.precision(prec);
    ss << num;
    ret = ss.str();
    return ret;
};

Maybe it's a bit complicated but it is quite complex. You create stringstream object ss, modify its flags, put a number into it with operator<<, and extract it via str(). I guess that operator>> could be used.

Also in this example the string buffer is hidden and not used explicitly. But it would be too long of a post to write about every possible aspect and use-case.

Note: I probably stole it from someone on SO and refined, but I don't have original author noted.

ASP.NET Setting width of DataBound column in GridView

<asp:GridView ID="GridView1" AutoGenerateEditButton="True" 
ondatabound="gv_DataBound" runat="server" DataSourceID="SqlDataSource1"
AutoGenerateColumns="False" width="600px">

<Columns>
                <asp:BoundField HeaderText="UserId" 
                DataField="UserId" 
                SortExpression="UserId" ItemStyle-Width="400px"></asp:BoundField>
   </Columns>
</asp:GridView>

ReactJs: What should the PropTypes be for this.props.children?

Example:

import React from 'react';
import PropTypes from 'prop-types';

class MenuItem extends React.Component {
    render() {
        return (
            <li>
                <a href={this.props.href}>{this.props.children}</a>
            </li>
        );
    }
}

MenuItem.defaultProps = {
    href: "/",
    children: "Main page"
};

MenuItem.propTypes = {
    href: PropTypes.string.isRequired,
    children: PropTypes.string.isRequired
};

export default MenuItem;

Picture: Shows you error in console if the expected type is different

Picture: Shows you error in console if the expected type is different

WebDriver - wait for element using Java

This is how I do it in my code.

WebDriverWait wait = new WebDriverWait(webDriver, timeoutInSeconds);
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id<locator>));

or

wait.until(ExpectedConditions.elementToBeClickable(By.id<locator>));

to be precise.

See also:

Convert this string to datetime

The Problem is with your code formatting,

inorder to use strtotime() You should replace '06/Oct/2011:19:00:02' with 06/10/2011 19:00:02 and date('d/M/Y:H:i:s', $date); with date('d/M/Y H:i:s', $date);. Note the spaces in between.

So the final code looks like this

$s = '06/10/2011 19:00:02';
$date = strtotime($s);
echo date('d/M/Y H:i:s', $date);

How to bring view in front of everything?

i have faced the same problem. the following solution have worked for me.

 FrameLayout glFrame=(FrameLayout) findViewById(R.id.animatedView);
        glFrame.addView(yourView);
        glFrame.bringToFront();
        glFrame.invalidate();

2nd solution is by using xml adding this attribute to the view xml

android:translationZ=""

What in the world are Spring beans?

The XML configuration of Spring is composed of Beans and Beans are basically classes. They're just POJOs that we use inside of our ApplicationContext. Defining Beans can be thought of as replacing the keyword new. So wherever you are using the keyword new in your application something like:

MyRepository myRepository =new MyRepository ();

Where you're using that keyword new that's somewhere you can look at removing that configuration and placing it into an XML file. So we will code like this:

<bean name="myRepository " 
      class="com.demo.repository.MyRepository " />

Now we can simply use Setter Injection/ Constructor Injection. I'm using Setter Injection.

public class MyServiceImpl implements MyService {
    private MyRepository myRepository;
    public void setMyRepository(MyRepository myRepository)
        {
    this.myRepository = myRepository ;
        }
public List<Customer> findAll() {
        return myRepository.findAll();
    }
}

Count a list of cells with the same background color

I was needed to solve absolutely the same task. I have divided visually the table using different background colors for different parts. Googling the Internet I've found this page https://support.microsoft.com/kb/2815384. Unfortunately it doesn't solve the issue because ColorIndex refers to some unpredictable value, so if some cells have nuances of one color (for example different values of brightness of the color), the suggested function counts them. The solution below is my fix:

Function CountBgColor(range As range, criteria As range) As Long
    Dim cell As range
    Dim color As Long
    color = criteria.Interior.color
    For Each cell In range
        If cell.Interior.color = color Then
            CountBgColor = CountBgColor + 1
        End If
    Next cell
End Function

Hadoop MapReduce: Strange Result when Storing Previous Value in Memory in a Reduce Class (Java)

It is very inefficient to store all values in memory, so the objects are reused and loaded one at a time. See this other SO question for a good explanation. Summary:

[...] when looping through the Iterable value list, each Object instance is re-used, so it only keeps one instance around at a given time.

Best way to compare 2 XML documents in Java

I required the same functionality as requested in the main question. As I was not allowed to use any 3rd party libraries, I have created my own solution basing on @Archimedes Trajano solution.

Following is my solution.

import java.io.ByteArrayInputStream;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.junit.Assert;
import org.w3c.dom.Document;

/**
 * Asserts for asserting XML strings.
 */
public final class AssertXml {

    private AssertXml() {
    }

    private static Pattern NAMESPACE_PATTERN = Pattern.compile("xmlns:(ns\\d+)=\"(.*?)\"");

    /**
     * Asserts that two XML are of identical content (namespace aliases are ignored).
     * 
     * @param expectedXml expected XML
     * @param actualXml actual XML
     * @throws Exception thrown if XML parsing fails
     */
    public static void assertEqualXmls(String expectedXml, String actualXml) throws Exception {
        // Find all namespace mappings
        Map<String, String> fullnamespace2newAlias = new HashMap<String, String>();
        generateNewAliasesForNamespacesFromXml(expectedXml, fullnamespace2newAlias);
        generateNewAliasesForNamespacesFromXml(actualXml, fullnamespace2newAlias);

        for (Entry<String, String> entry : fullnamespace2newAlias.entrySet()) {
            String newAlias = entry.getValue();
            String namespace = entry.getKey();
            Pattern nsReplacePattern = Pattern.compile("xmlns:(ns\\d+)=\"" + namespace + "\"");
            expectedXml = transletaNamespaceAliasesToNewAlias(expectedXml, newAlias, nsReplacePattern);
            actualXml = transletaNamespaceAliasesToNewAlias(actualXml, newAlias, nsReplacePattern);
        }

        // nomralize namespaces accoring to given mapping

        DocumentBuilder db = initDocumentParserFactory();

        Document expectedDocuemnt = db.parse(new ByteArrayInputStream(expectedXml.getBytes(Charset.forName("UTF-8"))));
        expectedDocuemnt.normalizeDocument();

        Document actualDocument = db.parse(new ByteArrayInputStream(actualXml.getBytes(Charset.forName("UTF-8"))));
        actualDocument.normalizeDocument();

        if (!expectedDocuemnt.isEqualNode(actualDocument)) {
            Assert.assertEquals(expectedXml, actualXml); //just to better visualize the diffeences i.e. in eclipse
        }
    }


    private static DocumentBuilder initDocumentParserFactory() throws ParserConfigurationException {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(false);
        dbf.setCoalescing(true);
        dbf.setIgnoringElementContentWhitespace(true);
        dbf.setIgnoringComments(true);
        DocumentBuilder db = dbf.newDocumentBuilder();
        return db;
    }

    private static String transletaNamespaceAliasesToNewAlias(String xml, String newAlias, Pattern namespacePattern) {
        Matcher nsMatcherExp = namespacePattern.matcher(xml);
        if (nsMatcherExp.find()) {
            xml = xml.replaceAll(nsMatcherExp.group(1) + "[:]", newAlias + ":");
            xml = xml.replaceAll(nsMatcherExp.group(1) + "=", newAlias + "=");
        }
        return xml;
    }

    private static void generateNewAliasesForNamespacesFromXml(String xml, Map<String, String> fullnamespace2newAlias) {
        Matcher nsMatcher = NAMESPACE_PATTERN.matcher(xml);
        while (nsMatcher.find()) {
            if (!fullnamespace2newAlias.containsKey(nsMatcher.group(2))) {
                fullnamespace2newAlias.put(nsMatcher.group(2), "nsTr" + (fullnamespace2newAlias.size() + 1));
            }
        }
    }

}

It compares two XML strings and takes care of any mismatching namespace mappings by translating them to unique values in both input strings.

Can be fine tuned i.e. in case of translation of namespaces. But for my requirements just does the job.

Capture event onclose browser

You're looking for the onclose event.

see: https://developer.mozilla.org/en/DOM/window.onclose

note that not all browsers support this (for example firefox 2)

Retrieving parameters from a URL

In pure Python:

def get_param_from_url(url, param_name):
    return [i.split("=")[-1] for i in url.split("?", 1)[-1].split("&") if i.startswith(param_name + "=")][0]

How to kill a running SELECT statement

If you want to stop process you can kill it manually from task manager onother side if you want to stop running query in DBMS you can stop as given here for ms sqlserver T-SQL STOP or ABORT command in SQL Server Hope it helps you

React Native Error: ENOSPC: System limit for number of file watchers reached

It happened to me with a node app I was developing on a Debian based distro. First, a simple restart solved it, but it happened again on another app.

Since it's related with the number of watchers that inotify uses to monitors files and look for changes in a directory, you have to set a higher number as limit:

I was able to solve it from the answer posted here (thanks to him!)

So, I ran:

echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p

Read more about what’s happening at https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers#the-technical-details

Hope it helps!

adding .css file to ejs

Your problem is not actually specific to ejs.

2 things to note here

  1. style.css is an external css file. So you dont need style tags inside that file. It should only contain the css.

  2. In your express app, you have to mention the public directory from which you are serving the static files. Like css/js/image

it can be done by

app.use(express.static(__dirname + '/public'));

assuming you put the css files in public folder from in your app root. now you have to refer to the css files in your tamplate files, like

<link href="/css/style.css" rel="stylesheet" type="text/css">

Here i assume you have put the css file in css folder inside your public folder.

So folder structure would be

.
./app.js
./public
    /css
        /style.css

How to use the PI constant in C++

You could also use boost, which defines important math constants with maximum accuracy for the requested type (i.e. float vs double).

const double pi = boost::math::constants::pi<double>();

Check out the boost documentation for more examples.

How to check if a process is in hang state (Linux)

Is there any command in Linux through which i can know if the process is in hang state.

There is no command, but once I had to do a very dumb hack to accomplish something similar. I wrote a Perl script which periodically (every 30 seconds in my case):

  • run ps to find list of PIDs of the watched processes (along with exec time, etc)
  • loop over the PIDs
  • start gdb attaching to the process using its PID, dumping stack trace from it using thread apply all where, detaching from the process
  • a process was declared hung if:
    • its stack trace didn't change and time didn't change after 3 checks
    • its stack trace didn't change and time was indicating 100% CPU load after 3 checks
  • hung process was killed to give a chance for a monitoring application to restart the hung instance.

But that was very very very very crude hack, done to reach an about-to-be-missed deadline and it was removed a few days later, after a fix for the buggy application was finally installed.

Otherwise, as all other responders absolutely correctly commented, there is no way to find whether the process hung or not: simply because the hang might occur for way to many reasons, often bound to the application logic.

The only way is for application itself being capable of indicating whether it is alive or not. Simplest way might be for example a periodic log message "I'm alive".

Exception of type 'System.OutOfMemoryException' was thrown.

Another thing to try is

Tools -> Options -> search for IIS -> tick Use the 64 bit version of IIS Express for web sites and projects.

Use the 64 bit version of IIS Express for web sites and projects screenshot

Logging in Scala

Haven't tried it yet, but Configgy looks promising for both configuration and logging:

http://github.com/robey/configgy/tree/master

Can I use Twitter Bootstrap and jQuery UI at the same time?

If don't store it locally and use the link that they provide you might have an improved performance.The client might have the scripts already cached in some cases. As for the case of jQueryUI i would recommend not loading it until necessary. They are both minimized, but you can fire up the console and look at the network tab and see how long it takes for it to load, once it is initially downloaded it will be cached so you shouldn't worry afterwards.My conclusion would be yes use them both but use a CDN

Reactjs setState() with a dynamic key name?

Can use a spread syntax, something like this:

inputChangeHandler : function (event) {
    this.setState( { 
        ...this.state,
        [event.target.id]: event.target.value
    } );
},

Remove specific rows from a data frame

 X <- data.frame(Variable1=c(11,14,12,15),Variable2=c(2,3,1,4))
> X
  Variable1 Variable2
1        11         2
2        14         3
3        12         1
4        15         4
> X[X$Variable1!=11 & X$Variable1!=12, ]
  Variable1 Variable2
2        14         3
4        15         4
> X[ ! X$Variable1 %in% c(11,12), ]
  Variable1 Variable2
2        14         3
4        15         4

You can functionalize this however you like.

How to start anonymous thread class

The entire new expression is an object reference, so methods can be invoked on it:

public class A {
    public static void main(String[] arg)
    {
        new Thread()
        {
            public void run() {
                System.out.println("blah");
            }
        }.start();
    }
}