Programs & Examples On #Appendfile

How to append to a file in Node?

I wrapped the async fs.appendFile into a Promise-based function. Hope it helps others to see how this would work.

    append (path, name, data) {

        return new Promise(async (resolve, reject) => {

            try {

                fs.appendFile((path + name), data, async (err) => {

                    if (!err) {

                        return resolve((path + name));

                    } else {

                        return reject(err);

                    }

                });

            } catch (err) {

                return reject(err);

            }

        });

    }

Java verify void method calls n times with Mockito

The necessary method is Mockito#verify:

public static <T> T verify(T mock,
                           VerificationMode mode)

mock is your mocked object and mode is the VerificationMode that describes how the mock should be verified. Possible modes are:

verify(mock, times(5)).someMethod("was called five times");
verify(mock, never()).someMethod("was never called");
verify(mock, atLeastOnce()).someMethod("was called at least once");
verify(mock, atLeast(2)).someMethod("was called at least twice");
verify(mock, atMost(3)).someMethod("was called at most 3 times");
verify(mock, atLeast(0)).someMethod("was called any number of times"); // useful with captors
verify(mock, only()).someMethod("no other method has been called on the mock");

You'll need these static imports from the Mockito class in order to use the verify method and these verification modes:

import static org.mockito.Mockito.atLeast;
import static org.mockito.Mockito.atLeastOnce;
import static org.mockito.Mockito.atMost;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.only;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

So in your case the correct syntax will be:

Mockito.verify(mock, times(4)).send()

This verifies that the method send was called 4 times on the mocked object. It will fail if it was called less or more than 4 times.


If you just want to check, if the method has been called once, then you don't need to pass a VerificationMode. A simple

verify(mock).someMethod("was called once");

would be enough. It internally uses verify(mock, times(1)).someMethod("was called once");.


It is possible to have multiple verification calls on the same mock to achieve a "between" verification. Mockito doesn't support something like this verify(mock, between(4,6)).someMethod("was called between 4 and 6 times");, but we can write

verify(mock, atLeast(4)).someMethod("was called at least four times ...");
verify(mock, atMost(6)).someMethod("... and not more than six times");

instead, to get the same behaviour. The bounds are included, so the test case is green when the method was called 4, 5 or 6 times.

How to send POST request in JSON using HTTPClient in Android?

There are couple of ways to establish HHTP connection and fetch data from a RESTFULL web service. The most recent one is GSON. But before you proceed to GSON you must have some idea of the most traditional way of creating an HTTP Client and perform data communication with a remote server. I have mentioned both the methods to send POST & GET requests using HTTPClient.

/**
 * This method is used to process GET requests to the server.
 * 
 * @param url 
 * @return String
 * @throws IOException
 */
public static String connect(String url) throws IOException {

    HttpGet httpget = new HttpGet(url);
    HttpResponse response;
    HttpParams httpParameters = new BasicHttpParams();
    // Set the timeout in milliseconds until a connection is established.
    // The default value is zero, that means the timeout is not used. 
    int timeoutConnection = 60*1000;
    HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
    // Set the default socket timeout (SO_TIMEOUT) 
    // in milliseconds which is the timeout for waiting for data.
    int timeoutSocket = 60*1000;

    HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
    HttpClient httpclient = new DefaultHttpClient(httpParameters);
    try {

        response = httpclient.execute(httpget);

        HttpEntity entity = response.getEntity();
        if (entity != null) {
            InputStream instream = entity.getContent();
            result = convertStreamToString(instream);
            //instream.close();
        }
    } 
    catch (ClientProtocolException e) {
        Utilities.showDLog("connect","ClientProtocolException:-"+e);
    } catch (IOException e) {
        Utilities.showDLog("connect","IOException:-"+e); 
    }
    return result;
}


 /**
 * This method is used to send POST requests to the server.
 * 
 * @param URL
 * @param paramenter
 * @return result of server response
 */
static public String postHTPPRequest(String URL, String paramenter) {       

    HttpParams httpParameters = new BasicHttpParams();
    // Set the timeout in milliseconds until a connection is established.
    // The default value is zero, that means the timeout is not used. 
    int timeoutConnection = 60*1000;
    HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
    // Set the default socket timeout (SO_TIMEOUT) 
    // in milliseconds which is the timeout for waiting for data.
    int timeoutSocket = 60*1000;

    HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
    HttpClient httpclient = new DefaultHttpClient(httpParameters);
    HttpPost httppost = new HttpPost(URL);
    httppost.setHeader("Content-Type", "application/json");
    try {
        if (paramenter != null) {
            StringEntity tmp = null;
            tmp = new StringEntity(paramenter, "UTF-8");
            httppost.setEntity(tmp);
        }
        HttpResponse httpResponse = null;
        httpResponse = httpclient.execute(httppost);
        HttpEntity entity = httpResponse.getEntity();
        if (entity != null) {
            InputStream input = null;
            input = entity.getContent();
            String res = convertStreamToString(input);
            return res;
        }
    } 
     catch (Exception e) {
        System.out.print(e.toString());
    }
    return null;
}

How to combine multiple inline style objects?

You can also combine classes with inline styling like this:

<View style={[className, {paddingTop: 25}]}>
  <Text>Some Text</Text>
</View>

How to search in a List of Java object

Using Java 8

With Java 8 you can simply convert your list to a stream allowing you to write:

import java.util.List;
import java.util.stream.Collectors;

List<Sample> list = new ArrayList<Sample>();
List<Sample> result = list.stream()
    .filter(a -> Objects.equals(a.value3, "three"))
    .collect(Collectors.toList());

Note that

  • a -> Objects.equals(a.value3, "three") is a lambda expression
  • result is a List with a Sample type
  • It's very fast, no cast at every iteration
  • If your filter logic gets heavier, you can do list.parallelStream() instead of list.stream() (read this)


Apache Commons

If you can't use Java 8, you can use Apache Commons library and write:

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;

Collection result = CollectionUtils.select(list, new Predicate() {
     public boolean evaluate(Object a) {
         return Objects.equals(((Sample) a).value3, "three");
     }
 });

// If you need the results as a typed array:
Sample[] resultTyped = (Sample[]) result.toArray(new Sample[result.size()]);

Note that:

  • There is a cast from Object to Sample at each iteration
  • If you need your results to be typed as Sample[], you need extra code (as shown in my sample)



Bonus: A nice blog article talking about how to find element in list.

C# find biggest number

I needed to find a way to do this too, using numbers from different places and not in a collection. I was sure there was a method to do this in c#...though by the looks of it I'm muddling my languages...

Anyway, I ended up writing a couple of generic methods to do it...

    static T Max<T>(params T[] numberItems)
    {
        return numberItems.Max();
    }

    static T Min<T>(params T[] numberItems)
    {
        return numberItems.Min();
    }

...call them this way...

    int intTest = Max(1, 2, 3, 4);
    float floatTest = Min(0f, 255.3f, 12f, -1.2f);

How to use a App.config file in WPF applications?

I have a Class Library WPF Project, and I Use:

'Read Settings
Dim value as string = My.Settings.my_key
value = "new value"

'Write Settings
My.Settings.my_key = value
My.Settings.Save()

Add an object to an Array of a custom class

If you want to create a garage and fill it up with new cars that can be accessed later, use this code:

for (int i = 0; i < garage.length; i++)
     garage[i] = new Car("argument");

Also, the cars are later accessed using:

garage[0];
garage[1];
garage[2];
etc.

Possible to access MVC ViewBag object from Javascript file?

In order to do this your JavaScript file would need to be pre-processed on the server side. Essentially, it would have to become an ASP.NET View of some kind, and script tags which reference the file would essentially be referencing a controller action which responds with that view.

That sounds like a can of worms you don't want to open.

Since JavaScript is client-side, why not just set the value to some client-side element and have the JavaScript interact with that. It's perhaps an additional step of indirection, but it sounds like much less of a headache than creating a JavaScript view.

Something like this:

<script type="text/javascript">
    var someValue = @ViewBag.someValue
</script>

Then the external JavaScript file can reference the someValue JavaScript variable within the scope of that document.

Or even:

<input type="hidden" id="someValue" value="@ViewBag.someValue" />

Then you can access that hidden input.

Unless you come up with some really slick way to actually make your JavaScript file usable as a view. It's certainly doable, and I can't readily think of any problems you'd have (other than really ugly view code since the view engine will get very confused as to what's JavaScript and what's Razor... so expect a ton of <text> markup), so if you find a slick way to do it that would be pretty cool, albeit perhaps unintuitive to someone who needs to support the code later.

Difference between maven scope compile and provided for JAR packaging

For a jar file, the difference is in the classpath listed in the MANIFEST.MF file included in the jar if addClassPath is set to true in the maven-jar-plugin configuration. 'compile' dependencies will appear in the manifest, 'provided' dependencies won't.

One of my pet peeves is that these two words should have the same tense. Either compiled and provided, or compile and provide.

Where IN clause in LINQ

I like it as an extension method:

public static bool In<T>(this T source, params T[] list)
{
    return list.Contains(source);
}

Now you call:

var states = _objdatasources.StateList().Where(s => s.In(countrycodes));

You can pass individual values too:

var states = tooManyStates.Where(s => s.In("x", "y", "z"));

Feels more natural and closer to sql.

HTML table needs spacing between columns, not rows

This can be achieved by putting padding between the columns using CSS. You can either add padding to the left of all columns except the first, or add padding to the right of all columns except the last. You should avoid adding padding to the right of the last column or to the left of the first as this will insert redundant white space. You should also avoid being too prescriptive with classes to specify which columns should have the additional padding as this will make maintenance harder if you later add a new column.

The 'lobotomised owl selector' allows you to select all siblings, regardless of if they are a th, td or something else.

_x000D_
_x000D_
tr > * + * {
  padding-left: 4em;
}
_x000D_
<table>
  <thead>
    <tr>
      <th>Column 1</th>
      <th>Column 2</th>
      <th>Column 3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Data 1</td>
      <td>Data 2</td>
      <td>Data 3</td>
    </tr>
  </tbody>
</table>
_x000D_
_x000D_
_x000D_

How can I get current date in Android?

This is the code i used:

             Date date = new Date();  // to get the date
             SimpleDateFormat df = new SimpleDateFormat("dd-MM-yyyy"); // getting date in this format
             String formattedDate = df.format(date.getTime());
             text.setText(formattedDate);

How can I declare a Boolean parameter in SQL statement?

The same way you declare any other variable, just use the bit type:

DECLARE @MyVar bit
Set @MyVar = 1  /* True */
Set @MyVar = 0  /* False */

SELECT * FROM [MyTable] WHERE MyBitColumn = @MyVar

Angularjs: Error: [ng:areq] Argument 'HomeController' is not a function, got undefined

Check if your HTML page includes:

  1. angular.min script
  2. app.js
  3. controller JavaScript page

The order the files are included is important. It was my solution to this problem.

Hope this helps.

Setting background-image using jQuery CSS property

Here is my code:

$('body').css('background-image', 'url("/apo/1.jpg")');

Enjoy, friend

Importing variables from another file?

Import file1 inside file2:

To import all variables from file1 without flooding file2's namespace, use:

import file1

#now use file1.x1, file2.x2, ... to access those variables

To import all variables from file1 to file2's namespace( not recommended):

from file1 import *
#now use x1, x2..

From the docs:

While it is valid to use from module import * at module level it is usually a bad idea. For one, this loses an important property Python otherwise has — you can know where each toplevel name is defined by a simple “search” function in your favourite editor. You also open yourself to trouble in the future, if some module grows additional functions or classes.

How to rename HTML "browse" button of an input type=file?

A bit of JavaScript will take care of it:

<script language="JavaScript" type="text/javascript">
function HandleBrowseClick()
{
    var fileinput = document.getElementById("browse");
    fileinput.click();
    var textinput = document.getElementById("filename");
    textinput.value = fileinput.value;
}
</script>

<input type="file" id="browse" name="fileupload" style="display: none"/>
<input type="text" id="filename" readonly="true"/>
<input type="button" value="Click to select file" id="fakeBrowse" onclick="HandleBrowseClick();"/>

Not the nicest looking solution, but it works.

Re-run Spring Boot Configuration Annotation Processor to update generated metadata

  1. Include a dependency on spring-boot-configuration-processor
  2. Click "Reimport All Maven Projects" in the Maven pane of IDEA
  3. Rebuild project

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.

Jquery, set value of td in a table?

$("#button_id").click(function(){ $("#detailInfo").html("WHAT YOU WANT") })

.includes() not working in Internet Explorer

This one may be better and shorter:

function stringIncludes(a, b) {
    return a.indexOf(b) >= 0;
}

What linux shell command returns a part of a string?

If you are looking for a shell utility to do something like that, you can use the cut command.

To take your example, try:

echo "abcdefg" | cut -c3-5

which yields

cde

Where -cN-M tells the cut command to return columns N to M, inclusive.

how to fix java.lang.IndexOutOfBoundsException

lstpp is empty. You cant access the first element of an empty list.

In general, you can check if size > index.

In your case, you need to check if lstpp is empty. (you can use !lstpp.isEmpty())

How to use a variable in the replacement side of the Perl substitution operator?

I did not manage to make the most popular answers work.

  • The ee method complained when my replacement string contained several consecutive backreferences.
  • Kent Fredric's answer only replaced the first match, and I need my search and replace to be global. I did not figure out a way to make it replace all matches that didn't cause other issues. For example, I tried running the method recursively until it no longer caused the string to change, but that causes an infinite loop if the replacement string contains the search string, whereas a regular global replacement does not do that.

I attempted to come up with a solution of my own using plain old eval:

eval '$var =~ s/' . $find . '/' . $replace . '/gsu;';

Of course, this allows for code injection. But as far as I know, the only way to escape the regex query and inject code is to insert two forward slashes in $find or one in $replace, followed by a semi-colon, after which you can add add code. For example, if I set the variables this way:

my $find = 'foo';
my $replace = 'bar/; print "You\'ve just been hacked!\n"; #';

The evaluated code is this:

$var =~ s/foo/bar/; print "You've just been hacked!\n"; #/gsu;';

So what I do is make sure the strings don't contain any unescaped forward slashes.

First, I copy the strings into dummy strings.

my $findTest = $find;
my $replaceTest = $replace;

Then, I remove all escaped backslashes (backslash pairs) from the dummy strings. This allows me to find forward slashes that are not escaped, without falling into the trap of considering a forward slash escaped if it's preceded by an escaped backslash. For example: \/ contains an escaped forward slash, but \\/ contains a literal forward slash, because the backslash is escaped.

$findTest =~ s/\\\\//gmu;
$replaceTest =~ s/\\\\//gmu;

Now if any forward slash that is not preceded by a backslash remains in the strings, I throw a fatal error, as that would allow the user to insert arbitrary code.

if ($findTest =~ /(?<!\\)\// || $replaceTest =~ /(?<!\\)\//)
{
  print "String must not contain unescaped slashes.\n";
  exit 1;
}

Then I eval.

eval '$var =~ s/' . $find . '/' . $replace . '/gsu;';

I'm not an expert at preventing code injection, but I'm the only one using my script, so I'm content using this solution without fully knowing if it's vulnerable. But as far as I know, it may be, so if anyone knows if there is or isn't any way to inject code into this, please provide your insight in a comment.

SimpleDateFormat parse loses timezone

tl;dr

what is the way to retrieve a Date object so that its always in GMT?

Instant.now() 

Details

You are using troublesome confusing old date-time classes that are now supplanted by the java.time classes.

Instant = UTC

The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).

Instant instant = Instant.now() ; // Current moment in UTC.

ISO 8601

To exchange this data as text, use the standard ISO 8601 formats exclusively. These formats are sensibly designed to be unambiguous, easy to process by machine, and easy to read across many cultures by people.

The java.time classes use the standard formats by default when parsing and generating strings.

String output = instant.toString() ;  

2017-01-23T12:34:56.123456789Z

Time zone

If you want to see that same moment as presented in the wall-clock time of a particular region, apply a ZoneId to get a ZonedDateTime.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

ZoneId z = ZoneId.of( "Asia/Singapore" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;  // Same simultaneous moment, same point on the timeline.

See this code live at IdeOne.com.

Notice the eight hour difference, as the time zone of Asia/Singapore currently has an offset-from-UTC of +08:00. Same moment, different wall-clock time.

instant.toString(): 2017-01-23T12:34:56.123456789Z

zdt.toString(): 2017-01-23T20:34:56.123456789+08:00[Asia/Singapore]

Convert

Avoid the legacy java.util.Date class. But if you must, you can convert. Look to new methods added to the old classes.

java.util.Date date = Date.from( instant ) ;

…going the other way…

Instant instant = myJavaUtilDate.toInstant() ;

Date-only

For date-only, use LocalDate.

LocalDate ld = zdt.toLocalDate() ;

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How to check if an option is selected?

Consider this as your select list:

<select onchange="var optionVal = $(this).find(':selected').val(); doSomething(optionVal)">

                                <option value="mostSeen">Most Seen</option>
                                <option value="newst">Newest</option>
                                <option value="mostSell">Most Sell</option>
                                <option value="mostCheap">Most Cheap</option>
                                <option value="mostExpensive">Most Expensive</option>

                            </select>

then you check selected option like this:

function doSomething(param) {

    if ($(param.selected)) {
        alert(param + ' is selected!');
    }

}

Iterating over Numpy matrix rows to apply a function each?

Use numpy.apply_along_axis(). Assuming your matrix is 2D, you can use like:

import numpy as np
mymatrix = np.matrix([[11,12,13],
                      [21,22,23],
                      [31,32,33]])
def myfunction( x ):
    return sum(x)

print np.apply_along_axis( myfunction, axis=1, arr=mymatrix )
#[36 66 96]

Does java.util.List.isEmpty() check if the list itself is null?

In addition to Lion's answer i can say that you better use if(CollectionUtils.isNotEmpty(test)){...} This also checks for null, so no manual check is not needed.

How can I use "." as the delimiter with String.split() in java

This is definitely not the best way to do this but, I got it done by doing something like following.

String imageName = "my_image.png";
String replace = imageName.replace('.','~');
String[] split = replace.split("~");

System.out.println("Image name : " + split[0]);
System.out.println("Image extension : " + split[1]);

Output,

Image name : my_image
Image extension : png

Delaying function in swift

Swift 3 and Above Version(s) for a delay of 10 seconds

    DispatchQueue.main.asyncAfter(deadline: .now() + 10) { [unowned self] in
        self.functionToCall()
    }

Center-align a HTML table

<table align="center"></table>

This works for me.

How should I validate an e-mail address?

Here is android.util.Patterns.EMAIL_ADDRESS

[a-zA-Z0-9+._\%-+]{1,256}\@[a-zA-Z0-9][a-zA-Z0-9-]{0,64}(.[a-zA-Z0-9][a-zA-Z0-9-]{0,25})+

String will match it if

Start by 1->256 character in (a-z, A-Z, 0-9, +, ., _, %, - , +)  
then 1 '@' character  
then 1 character in (a-z, A-Z, 0-9)  
then 0->64 character in (a-z, A-Z, 0-9, -)  
then **ONE OR MORE** 
         1 '.' character   
    then 1 character in (a-z, A-Z, 0-9)   
    then 0->25 character in (a-z, A-Z, 0-9, -)

Example some special match email

[email protected]
[email protected]
[email protected]

You may modify this pattern for your case then validate by

fun isValidEmail(email: String): Boolean {
    return Patterns.EMAIL_ADDRESS.matcher(email).matches()
}

How to change default format at created_at and updated_at value laravel

{{ $post->created_at }}

will return '2014-06-26 04:07:31'

The solution is

{{ $post->created_at->format('Y-m-d') }}

How can I get an HTTP response body as a string?

We can use the below code also to get the HTML Response in java

import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.HttpResponse;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import org.apache.log4j.Logger;

public static void main(String[] args) throws Exception {
    HttpClient client = new DefaultHttpClient();
    //  args[0] :-  http://hostname:8080/abc/xyz/CheckResponse
    HttpGet request1 = new HttpGet(args[0]);
    HttpResponse response1 = client.execute(request1);
    int code = response1.getStatusLine().getStatusCode();

    try (BufferedReader br = new BufferedReader(new InputStreamReader((response1.getEntity().getContent())));) {
        // Read in all of the post results into a String.
        String output = "";
        Boolean keepGoing = true;
        while (keepGoing) {
            String currentLine = br.readLine();

            if (currentLine == null) {
                keepGoing = false;
            } else {
                output += currentLine;
            }
        }

        System.out.println("Response-->" + output);
    } catch (Exception e) {
        System.out.println("Exception" + e);

    }
}

Number of times a particular character appears in a string

Use this function begining from SQL SERVER 2016

Select Count(value) From STRING_SPLIT('AAA AAA AAA',' ');

-- Output : 3 

When This function used with count function it gives you how many character exists in string

Installed Java 7 on Mac OS X but Terminal is still using version 6

This is nuts! How does Oracle provide an installer that doesn't install anything!?

Anyways for me it was:

sudo rm /usr/bin/java
sudo ln -s /Library/Java/JavaVirtualMachines/jdk1.8.0_31.jdk/Contents/Home/jre/bin/java /usr/bin/java

where 1.8.0_31 is your installed java version...

Recursively find files with a specific extension

My preference:

find . -name '*.jpg' -o -name '*.png' -print | grep Robert

Export query result to .csv file in SQL Server 2008

Using the native SQL Server Management Studio technique to export to CSV (as @8kb suggested) doesn't work if your values contain commas, because SSMS doesn't wrap values in double quotes. A more robust way that worked for me is to simply copy the results (click inside the grid and then CTRL-A, CTRL-C) and paste it into Excel. Then save as CSV file from Excel.

Java: Get month Integer from Date

java.time (Java 8)

You can also use the java.time package in Java 8 and convert your java.util.Date object to a java.time.LocalDate object and then just use the getMonthValue() method.

Date date = new Date();
LocalDate localDate = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
int month = localDate.getMonthValue();

Note that month values are here given from 1 to 12 contrary to cal.get(Calendar.MONTH) in adarshr's answer which gives values from 0 to 11.

But as Basil Bourque said in the comments, the preferred way is to get a Month enum object with the LocalDate::getMonth method.

How to get the selected index of a RadioGroup in Android

you can do

findViewById

from the radio group .

Here it is sample :

((RadioButton)my_radio_group.findViewById(R.id.radiobtn_veg)).setChecked(true);

How to view user privileges using windows cmd?

Mark Russinovich wrote a terrific tool called AccessChk that lets you get this information from the command line. No installation is necessary.

http://technet.microsoft.com/en-us/sysinternals/bb664922.aspx

For example:

accesschk.exe /accepteula -q -a SeServiceLogonRight

Returns this for me:

IIS APPPOOL\DefaultAppPool
IIS APPPOOL\Classic .NET AppPool
NT SERVICE\ALL SERVICES

By contrast, whoami /priv and whoami /all were missing some entries for me, like SeServiceLogonRight.

Change One Cell's Data in mysql

UPDATE only changes the values you specify:

UPDATE table SET cell='new_value' WHERE whatever='somevalue'

Unzip a file with php

PHP has its own inbuilt class that can be used to unzip or extracts contents from a zip file. The class is ZipArchive. Below is the simple and basic PHP code that will extract a zip file and place it in a specific directory:

<?php
$zip_obj = new ZipArchive;
$zip_obj->open('dummy.zip');
$zip_obj->extractTo('directory_name/sub_dir');
?>

If you want some advance features then below is the improved code that will check if the zip file exists or not:

<?php
$zip_obj = new ZipArchive;
if ($zip_obj->open('dummy.zip') === TRUE) {
   $zip_obj->extractTo('directory/sub_dir');
   echo "Zip exists and successfully extracted";
}
else {
   echo "This zip file does not exists";
}
?>

Source: How to unzip or extract zip files in PHP?

How to call a function after a div is ready?

You can use recursion here to do this. For example:

jQuery(document).ready(checkContainer);

function checkContainer () {
  if($('#divIDer').is(':visible'))){ //if the container is visible on the page
    createGrid();  //Adds a grid to the html
  } else {
    setTimeout(checkContainer, 50); //wait 50 ms, then try again
  }
}

Basically, this function will check to make sure that the element exists and is visible. If it is, it will run your createGrid() function. If not, it will wait 50ms and try again.

Note:: Ideally, you would just use the callback function of your AJAX call to know when the container was appended, but this is a brute force, standalone approach. :)

Creating an instance of class

Lines 1,2,3,4 will call the default constructor. They are different in the essence as 1,2 are dynamically created object and 3,4 are statically created objects.

In Line 7, you create an object inside the argument call. So its an error.

And Lines 5 and 6 are invitation for memory leak.

Importing large sql file to MySql via command line

You can import .sql file using the standard input like this:

mysql -u <user> -p<password> <dbname> < file.sql

Note: There shouldn't space between <-p> and <password>

Reference: http://dev.mysql.com/doc/refman/5.0/en/mysql-batch-commands.html

Note for suggested edits: This answer was slightly changed by suggested edits to use inline password parameter. I can recommend it for scripts but you should be aware that when you write password directly in the parameter (-p<password>) it may be cached by a shell history revealing your password to anyone who can read the history file. Whereas -p asks you to input password by standard input.

What is the best (and safest) way to merge a Git branch into master?

I would use the rebase method. Mostly because it perfectly reflects your case semantically, ie. what you want to do is to refresh the state of your current branch and "pretend" as if it was based on the latest.

So, without even checking out master, I would:

git fetch origin
git rebase -i origin/master
# ...solve possible conflicts here

Of course, just fetching from origin does not refresh the local state of your master (as it does not perform a merge), but it is perfectly ok for our purpose - we want to avoid switching around, for the sake of saving time.

How to change fontFamily of TextView in Android

You can also change standard fonts with setTextAppearance (requires API 16), see https://stackoverflow.com/a/36301508/2914140:

<style name="styleA">
    <item name="android:fontFamily">sans-serif</item>
    <item name="android:textStyle">bold</item>
    <item name="android:textColor">?android:attr/textColorPrimary</item>
</style>
<style name="styleB">
    <item name="android:fontFamily">sans-serif-light</item>
    <item name="android:textStyle">normal</item>
    <item name="android:textColor">?android:attr/textColorTertiary</item>
</style>


if(condition){
    TextViewCompat.setTextAppearance(textView, R.style.styleA);
} else {
    TextViewCompat.setTextAppearance(textView,R.style.styleB);
}

Style input element to fill remaining width of its container

If you're using Bootstrap 4:

<form class="d-flex">
  <label for="myInput" class="align-items-center">Sample label</label>
  <input type="text" id="myInput" placeholder="Sample Input" class="flex-grow-1"/>
</form>

Better yet, use what's built into Bootstrap:

  <form>
    <div class="input-group">
      <div class="input-group-prepend">
        <label for="myInput" class="input-group-text">Default</label>
      </div>
      <input type="text" class="form-control" id="myInput">
    </div>
  </form>

https://jsfiddle.net/nap1ykbr/

How to loop and render elements in React.js without an array of objects to map?

I'm using Object.keys(chars).map(...) to loop in render

// chars = {a:true, b:false, ..., z:false}

render() {
    return (
       <div>
        {chars && Object.keys(chars).map(function(char, idx) {
            return <span key={idx}>{char}</span>;
        }.bind(this))}
        "Some text value"
       </div>
    );
}

How to use WPF Background Worker

You may want to also look into using Task instead of background workers.

The easiest way to do this is in your example is Task.Run(InitializationThread);.

There are several benefits to using tasks instead of background workers. For example, the new async/await features in .net 4.5 use Task for threading. Here is some documentation about Task https://docs.microsoft.com/en-us/dotnet/api/system.threading.tasks.task

jQuery prevent change for select

You might need to use the ".live" option in jQuery since the behavior will be evaluated in real-time based on the condition you've set.

$('#my_select').live('change', function(ev) {
  if(my_condition)
  {
    ev.preventDefault();
    return false;
  }
});

How do you remove the title text from the Android ActionBar?

Got it. You have to override

android:actionBarStyle

and then in your custom style you have to override

android:titleTextStyle

Here's a sample.

In my themes.xml:

<style name="CustomActionBar" parent="android:style/Theme.Holo.Light">
        <item name="android:actionBarStyle">@style/CustomActionBarStyle</item>
</style>

And in my styles.xml:

<style name="CustomActionBarStyle" parent="android:style/Widget.Holo.ActionBar">
        <item name="android:titleTextStyle">@style/NoTitleText</item>
        <item name="android:subtitleTextStyle">@style/NoTitleText</item>
</style>

<style name="NoTitleText">
        <item name="android:textSize">0sp</item>
        <item name="android:textColor">#00000000</item>
</style>

I'm not sure why setting the textSize to zero didn't do the trick (it shrunk the text, but didn't make it go away), but setting the textColor to transparent works.

Disable LESS-CSS Overwriting calc()

The solutions of Fabricio works just fine.

A very common usecase of calc is add 100% width and adding some margin around the element.

One can do so with:

@someMarginVariable: 15px;

margin: @someMarginVariable;
width: calc(~"100% - "@someMarginVariable*2);
width: -moz-calc(~"100% - "@someMarginVariable*2);
width: -webkit-calc(~"100% - "@someMarginVariable*2);
width: -o-calc(~"100% - "@someMarginVariable*2);

Or can use a mixin like:

.fullWidthMinusMarginPaddingMixin(@marginSize,@paddingSize) {
  @minusValue: (@marginSize+@paddingSize)*2;
  padding: @paddingSize;
  margin: @marginSize;
  width: calc(~"100% - "@minusValue);
  width: -moz-calc(~"100% - "@minusValue);
  width: -webkit-calc(~"100% - "@minusValue);
  width: -o-calc(~"100% - "@minusValue);
}

how to bold words within a paragraph in HTML/CSS?

I know this question is old but I ran across it and I know other people might have the same problem. All these answers are okay but do not give proper detail or actual TRUE advice.

When wanting to style a specific section of a paragraph use the span tag.

<p><span style="font-weight:900">Andy Warhol</span> (August 6, 1928 - February 22, 1987) 

was an American artist who was a leading figure in the visual art movement known as pop 

art.</p>

Andy Warhol (August 6, 1928 - February 22, 1987) was an American artist who was a leading figure in the visual art movement known as pop art.

As the code shows, the span tag styles on the specified words: "Andy Warhol". You can further style a word using any CSS font styling codes.

{font-weight; font-size; text-decoration; font-family; margin; color}, etc. 

Any of these and more can be used to style a word, group of words, or even specified paragraphs without having to add a class to the CSS Style Sheet Doc. I hope this helps someone!

Help with packages in java - import does not work

Just add classpath entry ( I mean your parent directory location) under System Variables and User Variables menu ... Follow : Right Click My Computer>Properties>Advanced>Environment Variables

How to convert an Array to a Set in Java

There has been a lot of great answers already, but most of them won't work with array of primitives (like int[], long[], char[], byte[], etc.)

In Java 8 and above, you can box the array with:

Integer[] boxedArr = Arrays.stream(arr).boxed().toArray(Integer[]::new);

Then convert to set using stream:

Stream.of(boxedArr).collect(Collectors.toSet());

How to get the size of a JavaScript object?

There is a NPM module to get object sizeof, you can install it with npm install object-sizeof

  var sizeof = require('object-sizeof');

  // 2B per character, 6 chars total => 12B
  console.log(sizeof({abc: 'def'}));

  // 8B for Number => 8B
  console.log(sizeof(12345));

  var param = { 
    'a': 1, 
    'b': 2, 
    'c': {
      'd': 4
    }
  };
  // 4 one two-bytes char strings and 3 eighth-bytes numbers => 32B
  console.log(sizeof(param));

Plot multiple lines (data series) each with unique color in R

Here is another way to add lines using plot():

First, use function par(new=T)

option:

http://cran.r-project.org/doc/contrib/Lemon-kickstart/kr_addat.html

To color them differently you will need col().

To avoid superfluous axes descriptions use xaxt="n" and yaxt="n" for second and further plots.

Doctrine 2 ArrayCollection filter method

The Boris Guéry answer's at this post, may help you: Doctrine 2, query inside entities

$idsToFilter = array(1,2,3,4);

$member->getComments()->filter(
    function($entry) use ($idsToFilter) {
       return in_array($entry->getId(), $idsToFilter);
    }
); 

Asynchronous vs synchronous execution, what does it really mean?

Simple Explanation via analogy

Synchronous Execution

My boss is a busy man. He tells me to write the code. I tell him: Fine. I get started and he's watching me like a vulture, standing behind me, off my shoulder. I'm like "Dude, WTF: why don't you go and do something while I finish this?"

he's like: "No, I'm waiting right here until you finish." This is synchronous.

Asynchronous Execution

The boss tells me to do it, and rather than waiting right there for my work, the boss goes off and does other tasks. When I finish my job I simply report to my boss and say: "I'm DONE!" This is Asynchronous Execution.

(Take my advice: NEVER work with the boss behind you.)

How to read until EOF from cin in C++

You can do it without explicit loops by using stream iterators. I'm sure that it uses some kind of loop internally.

#include <string>
#include <iostream>
#include <istream>
#include <ostream>
#include <iterator>

int main()
{
// don't skip the whitespace while reading
  std::cin >> std::noskipws;

// use stream iterators to copy the stream to a string
  std::istream_iterator<char> it(std::cin);
  std::istream_iterator<char> end;
  std::string results(it, end);

  std::cout << results;
}

How do you create a temporary table in an Oracle database?

Just a tip.. Temporary tables in Oracle are different to SQL Server. You create it ONCE and only ONCE, not every session. The rows you insert into it are visible only to your session, and are automatically deleted (i.e., TRUNCATE, not DROP) when you end you session ( or end of the transaction, depending on which "ON COMMIT" clause you use).

get all keys set in memcached

Bash

To get list of keys in Bash, follow the these steps.

First, define the following wrapper function to make it simple to use (copy and paste into shell):

function memcmd() {
  exec {memcache}<>/dev/tcp/localhost/11211
  printf "%s\n%s\n" "$*" quit >&${memcache}
  cat <&${memcache}
}

Memcached 1.4.31 and above

You can use lru_crawler metadump all command to dump (most of) the metadata for (all of) the items in the cache.

As opposed to cachedump, it does not cause severe performance problems and has no limits on the amount of keys that can be dumped.

Example command by using the previously defined function:

memcmd lru_crawler metadump all

See: ReleaseNotes1431.


Memcached 1.4.30 and below

Get list of slabs by using items statistics command, e.g.:

memcmd stats items

For each slub class, you can get list of items by specifying slub id along with limit number (0 - unlimited):

memcmd stats cachedump 1 0
memcmd stats cachedump 2 0
memcmd stats cachedump 3 0
memcmd stats cachedump 4 0
...

Note: You need to do this for each memcached server.

To list all the keys from all stubs, here is the one-liner (per one server):

for id in $(memcmd stats items | grep -o ":[0-9]\+:" | tr -d : | sort -nu); do
    memcmd stats cachedump $id 0
done

Note: The above command could cause severe performance problems while accessing the items, so it's not advised to run on live.


Notes:

stats cachedump only dumps the HOT_LRU (IIRC?), which is managed by a background thread as activity happens. This means under a new enough version which the 2Q algo enabled, you'll get snapshot views of what's in just one of the LRU's.

If you want to view everything, lru_crawler metadump 1 (or lru_crawler metadump all) is the new mostly-officially-supported method that will asynchronously dump as many keys as you want. you'll get them out of order but it hits all LRU's, and unless you're deleting/replacing items multiple runs should yield the same results.

Source: GH-405.


Related:

React - How to force a function component to render?

Update react v16.8 (16 Feb 2019 realease)

Since react 16.8 released with hooks, function components are now have the ability to hold persistent state. With that ability you can now mimic a forceUpdate:

_x000D_
_x000D_
function App() {_x000D_
  const [, updateState] = React.useState();_x000D_
  const forceUpdate = React.useCallback(() => updateState({}), []);_x000D_
  console.log("render");_x000D_
  return (_x000D_
    <div>_x000D_
      <button onClick={forceUpdate}>Force Render</button>_x000D_
    </div>_x000D_
  );_x000D_
}_x000D_
_x000D_
const rootElement = document.getElementById("root");_x000D_
ReactDOM.render(<App />, rootElement);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.1/umd/react.production.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.1/umd/react-dom.production.min.js"></script>_x000D_
<div id="root"/>
_x000D_
_x000D_
_x000D_

Note that this approach should be re-considered and in most cases when you need to force an update you probably doing something wrong.


Before react 16.8.0

No you can't, State-Less function components are just normal functions that returns jsx, you don't have any access to the React life cycle methods as you are not extending from the React.Component.

Think of function-component as the render method part of the class components.

How to skip to next iteration in jQuery.each() util?

Javascript sort of has the idea of 'truthiness' and 'falsiness'. If a variable has a value then, generally 9as you will see) it has 'truthiness' - null, or no value tends to 'falsiness'. The snippets below might help:

var temp1; 
if ( temp1 )...  // false

var temp2 = true;
if ( temp2 )...  // true

var temp3 = "";
if ( temp3 ).... // false

var temp4 = "hello world";
if ( temp4 )...  // true

Hopefully that helps?

Also, its worth checking out these videos from Douglas Crockford

update: thanks @cphpython for spotting the broken links - I've updated to point at working versions now

The Javascript language

Javascript - The Good Parts

Recursively find all files newer than a given time

Maybe someone can use it. Find all files which were modified within a certain time frame recursively, just run:

find . -type f -newermt "2013-06-01" \! -newermt "2013-06-20"

What is an example of the simplest possible Socket.io example?

Edit: I feel it's better for anyone to consult the excellent chat example on the Socket.IO getting started page. The API has been quite simplified since I provided this answer. That being said, here is the original answer updated small-small for the newer API.

Just because I feel nice today:

index.html

<!doctype html>
<html>
    <head>
        <script src='/socket.io/socket.io.js'></script>
        <script>
            var socket = io();

            socket.on('welcome', function(data) {
                addMessage(data.message);

                // Respond with a message including this clients' id sent from the server
                socket.emit('i am client', {data: 'foo!', id: data.id});
            });
            socket.on('time', function(data) {
                addMessage(data.time);
            });
            socket.on('error', console.error.bind(console));
            socket.on('message', console.log.bind(console));

            function addMessage(message) {
                var text = document.createTextNode(message),
                    el = document.createElement('li'),
                    messages = document.getElementById('messages');

                el.appendChild(text);
                messages.appendChild(el);
            }
        </script>
    </head>
    <body>
        <ul id='messages'></ul>
    </body>
</html>

app.js

var http = require('http'),
    fs = require('fs'),
    // NEVER use a Sync function except at start-up!
    index = fs.readFileSync(__dirname + '/index.html');

// Send index.html to all requests
var app = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.end(index);
});

// Socket.io server listens to our app
var io = require('socket.io').listen(app);

// Send current time to all connected clients
function sendTime() {
    io.emit('time', { time: new Date().toJSON() });
}

// Send current time every 10 secs
setInterval(sendTime, 10000);

// Emit welcome message on connection
io.on('connection', function(socket) {
    // Use socket to communicate with this particular client only, sending it it's own id
    socket.emit('welcome', { message: 'Welcome!', id: socket.id });

    socket.on('i am client', console.log);
});

app.listen(3000);

Convert a file path to Uri in Android

Normal answer for this question if you really want to get something like content//media/external/video/media/18576 (e.g. for your video mp4 absolute path) and not just file///storage/emulated/0/DCIM/Camera/20141219_133139.mp4:

MediaScannerConnection.scanFile(this,
          new String[] { file.getAbsolutePath() }, null,
          new MediaScannerConnection.OnScanCompletedListener() {
      public void onScanCompleted(String path, Uri uri) {
          Log.i("onScanCompleted", uri.getPath());
      }
 });

Accepted answer is wrong (cause it will not return content//media/external/video/media/*)

Uri.fromFile(file).toString() only returns something like file///storage/emulated/0/* which is a simple absolute path of a file on the sdcard but with file// prefix (scheme)

You can also get content uri using MediaStore database of Android

TEST (what returns Uri.fromFile and what returns MediaScannerConnection):

File videoFile = new File("/storage/emulated/0/video.mp4");

Log.i(TAG, Uri.fromFile(videoFile).toString());

MediaScannerConnection.scanFile(this, new String[] { videoFile.getAbsolutePath() }, null,
        (path, uri) -> Log.i(TAG, uri.toString()));

Output:

I/Test: file:///storage/emulated/0/video.mp4

I/Test: content://media/external/video/media/268927

Selenium WebDriver: Wait for complex page with JavaScript to load

Here's from my own code:
Window.setTimeout executes only when browser is idle.
So calling the function recursively (42 times) will take 100ms if there is no activity in the browser and much more if the browser is busy doing something else.

    ExpectedCondition<Boolean> javascriptDone = new ExpectedCondition<Boolean>() {
        public Boolean apply(WebDriver d) {
            try{//window.setTimeout executes only when browser is idle,
                //introduces needed wait time when javascript is running in browser
                return  ((Boolean) ((JavascriptExecutor) d).executeAsyncScript( 

                        " var callback =arguments[arguments.length - 1]; " +
                        " var count=42; " +
                        " setTimeout( collect, 0);" +
                        " function collect() { " +
                            " if(count-->0) { "+
                                " setTimeout( collect, 0); " +
                            " } "+
                            " else {callback(" +
                            "    true" +                            
                            " );}"+                             
                        " } "
                    ));
            }catch (Exception e) {
                return Boolean.FALSE;
            }
        }
    };
    WebDriverWait w = new WebDriverWait(driver,timeOut);  
    w.until(javascriptDone);
    w=null;

As a bonus the counter can be reset on document.readyState or on jQuery Ajax calls or if any jQuery animations are running (only if your app uses jQuery for ajax calls...)
...

" function collect() { " +
                            " if(!((typeof jQuery === 'undefined') || ((jQuery.active === 0) && ($(\":animated\").length === 0))) && (document.readyState === 'complete')){" +
                            "    count=42;" +
                            "    setTimeout( collect, 0); " +
                            " }" +
                            " else if(count-->0) { "+
                                " setTimeout( collect, 0); " +
                            " } "+ 

...

EDIT: I notice executeAsyncScript doesn't work well if a new page loads and the test might stop responding indefinetly, better to use this on instead.

public static ExpectedCondition<Boolean> documentNotActive(final int counter){ 
    return new ExpectedCondition<Boolean>() {
        boolean resetCount=true;
        @Override
        public Boolean apply(WebDriver d) {

            if(resetCount){
                ((JavascriptExecutor) d).executeScript(
                        "   window.mssCount="+counter+";\r\n" + 
                        "   window.mssJSDelay=function mssJSDelay(){\r\n" + 
                        "       if((typeof jQuery != 'undefined') && (jQuery.active !== 0 || $(\":animated\").length !== 0))\r\n" + 
                        "           window.mssCount="+counter+";\r\n" + 
                        "       window.mssCount-->0 &&\r\n" + 
                        "       setTimeout(window.mssJSDelay,window.mssCount+1);\r\n" + 
                        "   }\r\n" + 
                        "   window.mssJSDelay();");
                resetCount=false;
            }

            boolean ready=false;
            try{
                ready=-1==((Long) ((JavascriptExecutor) d).executeScript(
                        "if(typeof window.mssJSDelay!=\"function\"){\r\n" + 
                        "   window.mssCount="+counter+";\r\n" + 
                        "   window.mssJSDelay=function mssJSDelay(){\r\n" + 
                        "       if((typeof jQuery != 'undefined') && (jQuery.active !== 0 || $(\":animated\").length !== 0))\r\n" + 
                        "           window.mssCount="+counter+";\r\n" + 
                        "       window.mssCount-->0 &&\r\n" + 
                        "       setTimeout(window.mssJSDelay,window.mssCount+1);\r\n" + 
                        "   }\r\n" + 
                        "   window.mssJSDelay();\r\n" + 
                        "}\r\n" + 
                        "return window.mssCount;"));
            }
            catch (NoSuchWindowException a){
                a.printStackTrace();
                return true;
            }
            catch (Exception e) {
                e.printStackTrace();
                return false;
            }
            return ready;
        }
        @Override
        public String toString() {
            return String.format("Timeout waiting for documentNotActive script");
        }
    };
}

ReactJS and images in public folder

You should use webpack here to make your life easier. Add below rule in your config:

const srcPath = path.join(__dirname, '..', 'publicfolder')

const rules = []

const includePaths = [
  srcPath
]
    // handle images
    rules.push({
      test: /\.(png|gif|jpe?g|svg|ico)$/,
      include: includePaths,
      use: [{
        loader: 'file-loader',
        options: {
          name: 'images/[name]-[hash].[ext]'
        }
      }

After this, you can simply import the images into your react components:

import myImage from 'publicfolder/images/Image1.png'

Use myImage like below:

<div><img src={myImage}/></div>

or if the image is imported into local state of component

<div><img src={this.state.myImage}/></div> 

How to get on scroll events?

// @HostListener('scroll', ['$event']) // for scroll events of the current element
@HostListener('window:scroll', ['$event']) // for window scroll events
onScroll(event) {
  ...
}

or

<div (scroll)="onScroll($event)"></div>

Check if a string is a valid date using DateTime.TryParse

Use DateTime.TryParseExact() if you want to match against a specific date format

 string format = "ddd dd MMM h:mm tt yyyy";
DateTime dateTime;
if (DateTime.TryParseExact(dateString, format, CultureInfo.InvariantCulture,
    DateTimeStyles.None, out dateTime))
{
    Console.WriteLine(dateTime);
}
else
{
    Console.WriteLine("Not a date");
}

Getting list of files in documents folder

Swift 2.0 Compability

func listWithFilter () {

    let fileManager = NSFileManager.defaultManager()
           // We need just to get the documents folder url
    let documentsUrl = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as NSURL

    do {
    // if you want to filter the directory contents you can do like this:
    if let directoryUrls = try? NSFileManager.defaultManager().contentsOfDirectoryAtURL(documentsUrl, includingPropertiesForKeys: nil, options: NSDirectoryEnumerationOptions.SkipsSubdirectoryDescendants) {
        print(directoryUrls)
       ........
        }

    }

}

OR

 func listFiles() -> [String] {

    var theError = NSErrorPointer()
    let dirs = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String]
    if dirs != nil {
        let dir = dirs![0]
        do {
        let fileList = try NSFileManager.defaultManager().contentsOfDirectoryAtPath(dir)
        return fileList as [String]
        }catch {

        }

    }else{
        let fileList = [""]
        return fileList
    }
    let fileList = [""]
    return fileList

}

Stretch and scale CSS background

Try the article background-size. If you use all of the following, it will work in most browsers except Internet Explorer.

.foo {
    background-image: url(bg-image.png);
    -moz-background-size: 100% 100%;
    -o-background-size: 100% 100%;
    -webkit-background-size: 100% 100%; 
    background-size: 100% 100%;
} 

Kill python interpeter in linux from the terminal

You can try the killall command:

killall python

How can I check a C# variable is an empty string "" or null?

Since .NET 2.0 you can use:

// Indicates whether the specified string is null or an Empty string.
string.IsNullOrEmpty(string value);

Additionally, since .NET 4.0 there's a new method that goes a bit farther:

// Indicates whether a specified string is null, empty, or consists only of white-space characters.
string.IsNullOrWhiteSpace(string value);

How do I sort a VARCHAR column in SQL server that contains numbers?

I solved it in a very simple way writing this in the "order" part

ORDER BY (
sr.codice +0
)
ASC

This seems to work very well, in fact I had the following sorting:

16079   Customer X 
016082  Customer Y
16413   Customer Z

So the 0 in front of 16082 is considered correctly.

How to terminate process from Python using pid?

So, not directly related but this is the first question that appears when you try to find how to terminate a process running from a specific folder using Python.

It also answers the question in a way(even though it is an old one with lots of answers).

While creating a faster way to scrape some government sites for data I had an issue where if any of the processes in the pool got stuck they would be skipped but still take up memory from my computer. This is the solution I reached for killing them, if anyone knows a better way to do it please let me know!

import pandas as pd
import wmi
from re import escape
import os

def kill_process(kill_path, execs):
    f = wmi.WMI()
    esc = escape(kill_path)
    temp = {'id':[], 'path':[], 'name':[]}
    for process in f.Win32_Process():
        temp['id'].append(process.ProcessId)
        temp['path'].append(process.ExecutablePath)
        temp['name'].append(process.Name)
    temp = pd.DataFrame(temp)
    temp = temp.dropna(subset=['path']).reset_index().drop(columns=['index'])
    temp = temp.loc[temp['path'].str.contains(esc)].loc[temp.name.isin(execs)].reset_index().drop(columns=['index'])
    [os.system('taskkill /PID {} /f'.format(t)) for t in temp['id']]

Formatting code in Notepad++

TextFX -> HTML Tidy -> Tidy: Reindent XML

Remember to have the HTML code selected before you do this.

How to set only time part of a DateTime variable in C#

It isn't possible as DateTime is immutable. The same discussion is available here: How to change time in datetime?

URL.Action() including route values

outgoing url in mvc generated based on the current routing schema.

because your Information action method require id parameter, and your route collection has id of your current requested url(/Admin/Information/5), id parameter automatically gotten from existing route collection values.

to solve this problem you should use UrlParameter.Optional:

 <a href="@Url.Action("Information", "Admin", new { id = UrlParameter.Optional })">Add an Admin</a>

What is the format for the PostgreSQL connection string / URL?

DATABASE_URL=postgres://{user}:{password}@{hostname}:{port}/{database-name}

PHP Error: Function name must be a string

Using parenthesis in a programming language or a scripting language usually means that it is a function.

However $_COOKIE in php is not a function, it is an Array. To access data in arrays you use square braces ('[' and ']') which symbolize which index to get the data from. So by doing $_COOKIE['test'] you are basically saying: "Give me the data from the index 'test'.

Now, in your case, you have two possibilities: (1) either you want to see if it is false--by looking inside the cookie or (2) see if it is not even there.

For this, you use the isset function which basically checks if the variable is set or not.

Example

if ( isset($_COOKIE['test'] ) )

And if you want to check if the value is false and it is set you can do the following:

if ( isset($_COOKIE['test']) && $_COOKIE['test'] == "false" )

One thing that you can keep in mind is that if the first test fails, it wont even bother checking the next statement if it is AND ( && ).

And to explain why you actually get the error "Function must be a string", look at this page. It's about basic creation of functions in PHP, what you must remember is that a function in PHP can only contain certain types of characters, where $ is not one of these. Since in PHP $ represents a variable.

A function could look like this: _myFunction _myFunction123 myFunction and in many other patterns as well, but mixing it with characters like $ and % will not work.

Encoding Error in Panda read_csv

Try calling read_csv with encoding='latin1', encoding='iso-8859-1' or encoding='cp1252' (these are some of the various encodings found on Windows).

How to find elements with 'value=x'?

$('#attached_docs [value="123"]').find ... .remove();

it should do your need however, you cannot duplicate id! remember it

DropdownList DataSource

You can bind the DropDownList in different ways by using List, Dictionary, Enum, DataSet DataTable.
Main you have to consider three thing while binding the datasource of a dropdown.

  1. DataSource - Name of the dataset or datatable or your datasource
  2. DataValueField - These field will be hidden
  3. DataTextField - These field will be displayed on the dropdwon.

you can use following code to bind a dropdownlist to a datasource as a datatable:

  SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString);

    SqlCommand cmd = new SqlCommand("Select * from tblQuiz", con);

    SqlDataAdapter da = new SqlDataAdapter(cmd);

    DataTable dt=new DataTable();
    da.Fill(dt);

    DropDownList1.DataTextField = "QUIZ_Name";
    DropDownList1.DataValueField = "QUIZ_ID"

    DropDownList1.DataSource = dt;
    DropDownList1.DataBind();

if you want to process on selection of dropdownlist, then you have to change AutoPostBack="true" you can use SelectedIndexChanged event to write your code.

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    string strQUIZ_ID=DropDownList1.SelectedValue;
    string strQUIZ_Name=DropDownList1.SelectedItem.Text;
    // Your code..............
}

Get timezone from users browser using moment(timezone).js

All current answers provide the offset differece at current time, not at a given date.

moment(date).utcOffset() returns the time difference in minutes between browser time and UTC at the date passed as argument (or today, if no date passed).

Here's a function to parse correct offset at the picked date:

function getUtcOffset(date) {
  return moment(date)
    .subtract(
      moment(date).utcOffset(), 
      'minutes')
    .utc()
}

LINQ: Select where object does not contain items from list

In general, you're looking for the "Except" extension.

var rejectStatus = GenerateRejectStatuses();
var fullList = GenerateFullList();
var rejectList = fullList.Where(i => rejectStatus.Contains(i.Status));
var filteredList = fullList.Except(rejectList);

In this example, GenerateRegectStatuses() should be the list of statuses you wish to reject (or in more concrete terms based on your example, a List<int> of IDs)

whitespaces in the path of windows filepath

(WINDOWS - AWS solution)
Solved for windows by putting tripple quotes around files and paths.
Benefits:
1) Prevents excludes that quietly were getting ignored.
2) Files/folders with spaces in them, will no longer kick errors.

    aws_command = 'aws s3 sync """D:/""" """s3://mybucket/my folder/"  --exclude """*RECYCLE.BIN/*""" --exclude """*.cab""" --exclude """System Volume Information/*""" '

    r = subprocess.run(f"powershell.exe {aws_command}", shell=True, capture_output=True, text=True)

C++ "was not declared in this scope" compile error

What's wrong:

The definition of "nonrecursivecountcells" has no parameter named grid. You need to pass the type AND variable name to the function. You only passed the type.

Note if you use the name grid for the parameter, that name has nothing to do with your main() declaration of grid. You could have used any other name as well.

***Also you can't pass arrays as values.


How to fix:

The easy way to fix this is to pass a pointer to an array to the function "nonrecursivecountcells".

int nonrecursivecountcells(color[ROW_SIZE][COL_SIZE], int, int);

better and type safe ->

int nonrecursivecountcells(color (&grid)[ROW_SIZE][COL_SIZE], int, int);

About scope:

A variable created on the stack comes out of scope when the block it is declared in is terminated. A block is anything within an opening and matching closing brace. For example an if() { }, function() { }, while() {}, ...

Note I said variable and not data. For example you can allocate memory on the heap and that data will still remain valid even outside of the scope. But the variable that originally pointed to it would still come out of scope.

youtube: link to display HD video by default

Nick Vogt at H3XED posted this syntax: https://www.youtube.com/v/VIDEOID?version=3&vq=hd1080

Take this link and replace the expression "VIDEOID" with the (shortened/shared) ID of the video.

Exapmple for ID: i3jNECZ3ybk looks like this: ... /v/i3jNECZ3ybk?version=3&vq=hd1080

What you get as a result is the standalone 1080p video but not in the Tube environment.

Apply formula to the entire column

It looks like some of the other answers have become outdated, but for me this worked:

  1. Click on the cell with the text/formula to copy
  2. Shift+Click on the last cell to copy to
  3. Ctrl + Enter

(Note that this replaces text if the destination cells aren't empty)

How to check the installed version of React-Native

If you want to see which version of react-native, react or another one you are running, open your terminal or cmd and run the desired command

npm view react-native version
0.63.4
npm view react version
17.0.1
npm view react-scripts version
4.0.1
npm view react-dom version
17.0.1

see my terminal

When a 'blur' event occurs, how can I find out which element focus went *to*?


I think its easily possible via jquery by passing the reference of the field causing the onblur event in "this".
For e.g.

<input type="text" id="text1" onblur="showMessageOnOnblur(this)">

function showMessageOnOnblur(field){
    alert($(field).attr("id"));
}

Thanks
Monika

gdb: how to print the current line or find the current line number?

Command where or frame can be used. where command will give more info with the function name

Gradle finds wrong JAVA_HOME even though it's correctly set

I have tested this on Manjaro Linux. Should work on other Disto too.

You need to include whole java-jdk dir instead of just java/bin for java env var.

For example, instead of:

export JAVA_HOME=/opt/jdk-14.0.2/bin #change path according to your jdk location PATH=$PATH:$JAVA_HOME

use this:

export JAVA_HOME=/opt/jdk-14.0.2/ #change path according to your jdk location PATH=$PATH:$JAVA_HOME

then run the gradle command it will work.

wget can't download - 404 error

I had the same problem. Solved using single quotes like this:

$ wget 'http://www.icerts.com/images/logo.jpg'

wget version in use:

$ wget --version
GNU Wget 1.11.4 Red Hat modified

sed one-liner to convert all uppercase to lowercase?

With tr:

# Converts upper to lower case 
$ tr '[:upper:]' '[:lower:]' < input.txt > output.txt

# Converts lower to upper case
$ tr '[:lower:]' '[:upper:]' < input.txt > output.txt

Or, sed on GNU (but not BSD or Mac as they don't support \L or \U):

# Converts upper to lower case
$ sed -e 's/\(.*\)/\L\1/' input.txt > output.txt

# Converts lower to upper case
$ sed -e 's/\(.*\)/\U\1/' input.txt > output.txt
 

Function inside a function.?

X returns (value +3), while Y returns (value*2)

Given a value of 4, this means (4+3) * (4*2) = 7 * 8 = 56.

Although functions are not limited in scope (which means that you can safely 'nest' function definitions), this particular example is prone to errors:

1) You can't call y() before calling x(), because function y() won't actually be defined until x() has executed once.

2) Calling x() twice will cause PHP to redeclare function y(), leading to a fatal error:

Fatal error: Cannot redeclare y()

The solution to both would be to split the code, so that both functions are declared independent of each other:

function x ($y) 
{
  return($y+3);
}

function y ($z)
{
  return ($z*2);
}

This is also a lot more readable.

Can I set an unlimited length for maxJsonLength in web.config?

I fixed it.

//your Json data here
string json_object="........";
JavaScriptSerializer jsJson = new JavaScriptSerializer();
jsJson.MaxJsonLength = 2147483644;
MyClass obj = jsJson.Deserialize<MyClass>(json_object);

It works very well.

Most efficient way to reverse a numpy array

As mentioned above, a[::-1] really only creates a view, so it's a constant-time operation (and as such doesn't take longer as the array grows). If you need the array to be contiguous (for example because you're performing many vector operations with it), ascontiguousarray is about as fast as flipud/fliplr:

enter image description here


Code to generate the plot:

import numpy
import perfplot


perfplot.show(
    setup=lambda n: numpy.random.randint(0, 1000, n),
    kernels=[
        lambda a: a[::-1],
        lambda a: numpy.ascontiguousarray(a[::-1]),
        lambda a: numpy.fliplr([a])[0],
    ],
    labels=["a[::-1]", "ascontiguousarray(a[::-1])", "fliplr"],
    n_range=[2 ** k for k in range(25)],
    xlabel="len(a)",
)

Flask raises TemplateNotFound error even though template file exists

I don't know why, but I had to use the following folder structure instead. I put "templates" one level up.

project/
    app/
        hello.py
        static/
            main.css
    templates/
        home.html
    venv/

This probably indicates a misconfiguration elsewhere, but I couldn't figure out what that was and this worked.

How do I create a constant in Python?

The Pythonic way of declaring "constants" is basically a module level variable:

RED = 1
GREEN = 2
BLUE = 3

And then write your classes or functions. Since constants are almost always integers, and they are also immutable in Python, you have a very little chance of altering it.

Unless, of course, if you explicitly set RED = 2.

Angular 2 - View not updating after model changes

In my case, I had a very similar problem. I was updating my view inside a function that was being called by a parent component, and in my parent component I forgot to use @ViewChild(NameOfMyChieldComponent). I lost at least 3 hours just for this stupid mistake. i.e: I didn't need to use any of those methods:

  • ChangeDetectorRef.detectChanges()
  • ChangeDetectorRef.markForCheck()
  • ApplicationRef.tick()

Terminating a script in PowerShell

I coincidentally found out that Break <UnknownLabel> (e.g. simply Break Script, where the label Script doesn't exists) appears to break out of the entire script (even from within a function) and keeps the host alive.
This way you could create a function that breaks the script from anywhere (e.g. a recursive loop) without knowing the current scope (and creating labels):

Function Quit($Text) {
    Write-Host "Quiting because: " $Text
    Break Script
} 

Cutting the videos based on start and end time using ffmpeg

You probably do not have a keyframe at the 3 second mark. Because non-keyframes encode differences from other frames, they require all of the data starting with the previous keyframe.

With the mp4 container it is possible to cut at a non-keyframe without re-encoding using an edit list. In other words, if the closest keyframe before 3s is at 0s then it will copy the video starting at 0s and use an edit list to tell the player to start playing 3 seconds in.

If you are using the latest ffmpeg from git master it will do this using an edit list when invoked using the command that you provided. If this is not working for you then you are probably either using an older version of ffmpeg, or your player does not support edit lists. Some players will ignore the edit list and always play all of the media in the file from beginning to end.

If you want to cut precisely starting at a non-keyframe and want it to play starting at the desired point on a player that does not support edit lists, or want to ensure that the cut portion is not actually in the output file (for example if it contains confidential information), then you can do that by re-encoding so that there will be a keyframe precisely at the desired start time. Re-encoding is the default if you do not specify copy. For example:

ffmpeg -i movie.mp4 -ss 00:00:03 -t 00:00:08 -async 1 cut.mp4

When re-encoding you may also wish to include additional quality-related options or a particular AAC encoder. For details, see ffmpeg's x264 Encoding Guide for video and AAC Encoding Guide for audio.

Also, the -t option specifies a duration, not an end time. The above command will encode 8s of video starting at 3s. To start at 3s and end at 8s use -t 5. If you are using a current version of ffmpeg you can also replace -t with -to in the above command to end at the specified time.

Using module 'subprocess' with timeout

The solution I use is to prefix the shell command with timelimit. If the comand takes too long, timelimit will stop it and Popen will have a returncode set by timelimit. If it is > 128, it means timelimit killed the process.

See also python subprocess with timeout and large output (>64K)

How to replace innerHTML of a div using jQuery?

There are already answers which give how to change Inner HTML of element.

But I would suggest, you should use some animation like Fade Out/ Fade In to change HTML which gives good effect of changed HTML rather instantly changing inner HTML.

Use animation to change Inner HTML

$('#regTitle').fadeOut(500, function() {
    $(this).html('Hello World!').fadeIn(500);
});

If you have many functions which need this, then you can call common function which changes inner Html.

function changeInnerHtml(elementPath, newText){
    $(elementPath).fadeOut(500, function() {
        $(this).html(newText).fadeIn(500);
    });
}

MySQL error #1054 - Unknown column in 'Field List'

You have an error in your OrderQuantity column. It is named "OrderQuantity" in the INSERT statement and "OrderQantity" in the table definition.

Also, I don't think you can use NOW() as default value in OrderDate. Try to use the following:

 OrderDate TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP

Example Fiddle

Could not reserve enough space for object heap to start JVM

I had the same problem when using a 32 bit version of java in a 64 bit environment. When using 64 java in a 64 OS it was ok.

What does the "__block" keyword mean?

It tells the compiler that any variable marked by it must be treated in a special way when it is used inside a block. Normally, variables and their contents that are also used in blocks are copied, thus any modification done to these variables don't show outside the block. When they are marked with __block, the modifications done inside the block are also visible outside of it.

For an example and more info, see The __block Storage Type in Apple's Blocks Programming Topics.

The important example is this one:

extern NSInteger CounterGlobal;
static NSInteger CounterStatic;

{
    NSInteger localCounter = 42;
    __block char localCharacter;

    void (^aBlock)(void) = ^(void) {
        ++CounterGlobal;
        ++CounterStatic;
        CounterGlobal = localCounter; // localCounter fixed at block creation
        localCharacter = 'a'; // sets localCharacter in enclosing scope
    };

    ++localCounter; // unseen by the block
    localCharacter = 'b';

    aBlock(); // execute the block
    // localCharacter now 'a'
}

In this example, both localCounter and localCharacter are modified before the block is called. However, inside the block, only the modification to localCharacter would be visible, thanks to the __block keyword. Conversely, the block can modify localCharacter and this modification is visible outside of the block.

Mapping over values in a python dictionary

To avoid doing indexing from inside lambda, like:

rval = dict(map(lambda kv : (kv[0], ' '.join(kv[1])), rval.iteritems()))

You can also do:

rval = dict(map(lambda(k,v) : (k, ' '.join(v)), rval.iteritems()))

Rollback to last git commit

If you want to just uncommit the last commit use this:

git reset HEAD~

work like charm for me.

IIS - can't access page by ip address instead of localhost

Check the settings of the browser proxy . For me it helped , traffic was directed outside.

Get the generated SQL statement from a SqlCommand object?

Used part of Flapper's code for my solution, which returns the entire SQL string including parameter values to run in MS SQL SMS.

public string ParameterValueForSQL(SqlParameter sp)
    {
        string retval = "";

        switch (sp.SqlDbType)
        {
            case SqlDbType.Char:
            case SqlDbType.NChar:
            case SqlDbType.NText:
            case SqlDbType.NVarChar:
            case SqlDbType.Text:
            case SqlDbType.Time:
            case SqlDbType.VarChar:
            case SqlDbType.Xml:
            case SqlDbType.Date:
            case SqlDbType.DateTime:
            case SqlDbType.DateTime2:
            case SqlDbType.DateTimeOffset:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = "'" + sp.Value.ToString().Replace("'", "''") + "'";
                }
                break;

            case SqlDbType.Bit:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = ((bool)sp.Value == false) ? "0" : "1";
                }
                break;

            default:
                if (sp.Value == DBNull.Value)
                {
                    retval = "NULL";
                }
                else
                {
                    retval = sp.Value.ToString().Replace("'", "''");
                }
                break;
        }

        return retval;
    }


    public string CommandAsSql(SqlCommand sc)
    {
        string sql = sc.CommandText;

        sql = sql.Replace("\r\n", "").Replace("\r", "").Replace("\n", "");
        sql = System.Text.RegularExpressions.Regex.Replace(sql, @"\s+", " ");

        foreach (SqlParameter sp in sc.Parameters)
        {
            string spName = sp.ParameterName;
            string spValue = ParameterValueForSQL(sp);
            sql = sql.Replace(spName, spValue);
        }

        sql = sql.Replace("= NULL", "IS NULL");
        sql = sql.Replace("!= NULL", "IS NOT NULL");
        return sql;
    }

Regular Expression: Any character that is NOT a letter or number

Just for others to see:

someString.replaceAll("([^\\p{L}\\p{N}])", " ");

will remove any non-letter and non-number unicode characters.

Source

What does %>% function mean in R?

The R packages dplyr and sf import the operator %>% from the R package magrittr.

Help is available by using the following command:

?'%>%'

Of course the package must be loaded before by using e.g.

library(sf)

The documentation of the magrittr forward-pipe operator gives a good example: When functions require only one argument, x %>% f is equivalent to f(x)

Activity has leaked window that was originally added

This problem arises when trying to show a Dialog after you've exited an Activity.

I just solved this problem just by writing down the following code:

@Override
public void onDestroy(){
    super.onDestroy();
    if ( progressDialog!=null && progressDialog.isShowing() ){
        progressDialog.cancel();
    }
}

Basically, from which class you started progressDialog, override onDestroy method and do this way. It solved "Activity has leaked window" problem.

How to fix the session_register() deprecated issue?

Use $_SESSION directly to set variables. Like this:

$_SESSION['name'] = 'stack';

Instead of:

$name = 'stack';
session_register("name");

Read More Here

How can I specify a [DllImport] path at runtime?

DllImport will work fine without the complete path specified as long as the dll is located somewhere on the system path. You may be able to temporarily add the user's folder to the path.

Identifying and removing null characters in UNIX

Here is example how to remove NULL characters using ex (in-place):

ex -s +"%s/\%x00//g" -cwq nulls.txt

and for multiple files:

ex -s +'bufdo!%s/\%x00//g' -cxa *.txt

For recursivity, you may use globbing option **/*.txt (if it is supported by your shell).

Useful for scripting since sed and its -i parameter is a non-standard BSD extension.

See also: How to check if the file is a binary file and read all the files which are not?

How do I get the information from a meta tag with JavaScript?

There is an easier way:

document.getElementsByName('name of metatag')[0].getAttribute('content')

Android: How can I validate EditText input?

This looks really promising and just what the doc ordered for me:

EditText Validator

    public void onClickNext(View v) {
    FormEditText[] allFields    = { etFirstname, etLastname, etAddress, etZipcode, etCity };
    
    
    boolean allValid = true;
    for (FormEditText field: allFields) {
        allValid = field.testValidity() && allValid;
    }
    
    if (allValid) {
        // YAY
    } else {
        // EditText are going to appear with an exclamation mark and an explicative message.
    }
}

custom validators plus these built in:

  • regexp: for custom regexp
  • numeric: for an only numeric field
  • alpha: for an alpha only field
  • alphaNumeric: guess what?
  • personName: checks if the entered text is a person first or last name.
  • personFullName: checks if the entered value is a complete full name.
  • email: checks that the field is a valid email
  • creditCard: checks that the field contains a valid credit card using Luhn Algorithm
  • phone: checks that the field contains a valid phone number
  • domainName: checks that field contains a valid domain name ( always passes the test in API Level < 8 )
  • ipAddress: checks that the field contains a valid ip address
  • webUrl: checks that the field contains a valid url ( always passes the test in API Level < 8 )
  • date: checks that the field is a valid date/datetime format ( if customFormat is set, checks with customFormat )
  • nocheck: It does not check anything except the emptyness of the field.

How to write to a file in Scala?

UPDATE on 2019/Sep/01:

  • Starting with Scala 2.13, prefer using scala.util.Using
  • Fixed bug where finally would swallow original Exception thrown by try if finally code threw an Exception

After reviewing all of these answers on how to easily write a file in Scala, and some of them are quite nice, I had three issues:

  1. In the Jus12's answer, the use of currying for the using helper method is non-obvious for Scala/FP beginners
  2. Needs to encapsulate lower level errors with scala.util.Try
  3. Needs to show Java developers new to Scala/FP how to properly nest dependent resources so the close method is performed on each dependent resource in reverse order - Note: closing dependent resources in reverse order ESPECIALLY IN THE EVENT OF A FAILURE is a rarely understood requirement of the java.lang.AutoCloseable specification which tends to lead to very pernicious and difficult to find bugs and run time failures

Before starting, my goal isn't conciseness. It's to facilitate easier understanding for Scala/FP beginners, typically those coming from Java. At the very end, I will pull all the bits together, and then increase the conciseness.

First, the using method needs to be updated to use Try (again, conciseness is not the goal here). It will be renamed to tryUsingAutoCloseable:

def tryUsingAutoCloseable[A <: AutoCloseable, R]
  (instantiateAutoCloseable: () => A) //parameter list 1
  (transfer: A => scala.util.Try[R])  //parameter list 2
: scala.util.Try[R] =
  Try(instantiateAutoCloseable())
    .flatMap(
      autoCloseable => {
        var optionExceptionTry: Option[Exception] = None
        try
          transfer(autoCloseable)
        catch {
          case exceptionTry: Exception =>
            optionExceptionTry = Some(exceptionTry)
            throw exceptionTry
        }
        finally
          try
            autoCloseable.close()
          catch {
            case exceptionFinally: Exception =>
              optionExceptionTry match {
                case Some(exceptionTry) =>
                  exceptionTry.addSuppressed(exceptionFinally)
                case None =>
                  throw exceptionFinally
              }
          }
      }
    )

The beginning of the above tryUsingAutoCloseable method might be confusing because it appears to have two parameter lists instead of the customary single parameter list. This is called currying. And I won't go into detail how currying works or where it is occasionally useful. It turns out that for this particular problem space, it's the right tool for the job.

Next, we need to create method, tryPrintToFile, which will create a (or overwrite an existing) File and write a List[String]. It uses a FileWriter which is encapsulated by a BufferedWriter which is in turn encapsulated by a PrintWriter. And to elevate performance, a default buffer size much larger than the default for BufferedWriter is defined, defaultBufferSize, and assigned the value 65536.

Here's the code (and again, conciseness is not the goal here):

val defaultBufferSize: Int = 65536

def tryPrintToFile(
  lines: List[String],
  location: java.io.File,
  bufferSize: Int = defaultBufferSize
): scala.util.Try[Unit] = {
  tryUsingAutoCloseable(() => new java.io.FileWriter(location)) { //this open brace is the start of the second curried parameter to the tryUsingAutoCloseable method
    fileWriter =>
      tryUsingAutoCloseable(() => new java.io.BufferedWriter(fileWriter, bufferSize)) { //this open brace is the start of the second curried parameter to the tryUsingAutoCloseable method
        bufferedWriter =>
          tryUsingAutoCloseable(() => new java.io.PrintWriter(bufferedWriter)) { //this open brace is the start of the second curried parameter to the tryUsingAutoCloseable method
            printWriter =>
              scala.util.Try(
                lines.foreach(line => printWriter.println(line))
              )
          }
      }
  }
}

The above tryPrintToFile method is useful in that it takes a List[String] as input and sends it to a File. Let's now create a tryWriteToFile method which takes a String and writes it to a File.

Here's the code (and I'll let you guess conciseness's priority here):

def tryWriteToFile(
  content: String,
  location: java.io.File,
  bufferSize: Int = defaultBufferSize
): scala.util.Try[Unit] = {
  tryUsingAutoCloseable(() => new java.io.FileWriter(location)) { //this open brace is the start of the second curried parameter to the tryUsingAutoCloseable method
    fileWriter =>
      tryUsingAutoCloseable(() => new java.io.BufferedWriter(fileWriter, bufferSize)) { //this open brace is the start of the second curried parameter to the tryUsingAutoCloseable method
        bufferedWriter =>
          Try(bufferedWriter.write(content))
      }
  }
}

Finally, it is useful to be able to fetch the contents of a File as a String. While scala.io.Source provides a convenient method for easily obtaining the contents of a File, the close method must be used on the Source to release the underlying JVM and file system handles. If this isn't done, then the resource isn't released until the JVM GC (Garbage Collector) gets around to releasing the Source instance itself. And even then, there is only a weak JVM guarantee the finalize method will be called by the GC to close the resource. This means that it is the client's responsibility to explicitly call the close method, just the same as it is the responsibility of a client to tall close on an instance of java.lang.AutoCloseable. For this, we need a second definition of the using method which handles scala.io.Source.

Here's the code for this (still not being concise):

def tryUsingSource[S <: scala.io.Source, R]
  (instantiateSource: () => S)
  (transfer: S => scala.util.Try[R])
: scala.util.Try[R] =
  Try(instantiateSource())
    .flatMap(
      source => {
        var optionExceptionTry: Option[Exception] = None
        try
          transfer(source)
        catch {
          case exceptionTry: Exception =>
            optionExceptionTry = Some(exceptionTry)
            throw exceptionTry
        }
        finally
          try
            source.close()
          catch {
            case exceptionFinally: Exception =>
              optionExceptionTry match {
                case Some(exceptionTry) =>
                  exceptionTry.addSuppressed(exceptionFinally)
                case None =>
                  throw exceptionFinally
              }
          }
      }
    )

And here is an example usage of it in a super simple line streaming file reader (currently using to read tab-delimited files from database output):

def tryProcessSource(
    file: java.io.File
  , parseLine: (String, Int) => List[String] = (line, index) => List(line)
  , filterLine: (List[String], Int) => Boolean = (values, index) => true
  , retainValues: (List[String], Int) => List[String] = (values, index) => values
  , isFirstLineNotHeader: Boolean = false
): scala.util.Try[List[List[String]]] =
  tryUsingSource(scala.io.Source.fromFile(file)) {
    source =>
      scala.util.Try(
        ( for {
            (line, index) <-
              source.getLines().buffered.zipWithIndex
            values =
              parseLine(line, index)
            if (index == 0 && !isFirstLineNotHeader) || filterLine(values, index)
            retainedValues =
              retainValues(values, index)
          } yield retainedValues
        ).toList //must explicitly use toList due to the source.close which will
                 //occur immediately following execution of this anonymous function
      )
  )

An updated version of the above function has been provided as an answer to a different but related StackOverflow question.


Now, bringing that all together with the imports extracted (making it much easier to paste into Scala Worksheet present in both Eclipse ScalaIDE and IntelliJ Scala plugin to make it easy to dump output to the desktop to be more easily examined with a text editor), this is what the code looks like (with increased conciseness):

import scala.io.Source
import scala.util.Try
import java.io.{BufferedWriter, FileWriter, File, PrintWriter}

val defaultBufferSize: Int = 65536

def tryUsingAutoCloseable[A <: AutoCloseable, R]
  (instantiateAutoCloseable: () => A) //parameter list 1
  (transfer: A => scala.util.Try[R])  //parameter list 2
: scala.util.Try[R] =
  Try(instantiateAutoCloseable())
    .flatMap(
      autoCloseable => {
        var optionExceptionTry: Option[Exception] = None
        try
          transfer(autoCloseable)
        catch {
          case exceptionTry: Exception =>
            optionExceptionTry = Some(exceptionTry)
            throw exceptionTry
        }
        finally
          try
            autoCloseable.close()
          catch {
            case exceptionFinally: Exception =>
              optionExceptionTry match {
                case Some(exceptionTry) =>
                  exceptionTry.addSuppressed(exceptionFinally)
                case None =>
                  throw exceptionFinally
              }
          }
      }
    )

def tryUsingSource[S <: scala.io.Source, R]
  (instantiateSource: () => S)
  (transfer: S => scala.util.Try[R])
: scala.util.Try[R] =
  Try(instantiateSource())
    .flatMap(
      source => {
        var optionExceptionTry: Option[Exception] = None
        try
          transfer(source)
        catch {
          case exceptionTry: Exception =>
            optionExceptionTry = Some(exceptionTry)
            throw exceptionTry
        }
        finally
          try
            source.close()
          catch {
            case exceptionFinally: Exception =>
              optionExceptionTry match {
                case Some(exceptionTry) =>
                  exceptionTry.addSuppressed(exceptionFinally)
                case None =>
                  throw exceptionFinally
              }
          }
      }
    )

def tryPrintToFile(
  lines: List[String],
  location: File,
  bufferSize: Int = defaultBufferSize
): Try[Unit] =
  tryUsingAutoCloseable(() => new FileWriter(location)) { fileWriter =>
    tryUsingAutoCloseable(() => new BufferedWriter(fileWriter, bufferSize)) { bufferedWriter =>
      tryUsingAutoCloseable(() => new PrintWriter(bufferedWriter)) { printWriter =>
          Try(lines.foreach(line => printWriter.println(line)))
      }
    }
  }

def tryWriteToFile(
  content: String,
  location: File,
  bufferSize: Int = defaultBufferSize
): Try[Unit] =
  tryUsingAutoCloseable(() => new FileWriter(location)) { fileWriter =>
    tryUsingAutoCloseable(() => new BufferedWriter(fileWriter, bufferSize)) { bufferedWriter =>
      Try(bufferedWriter.write(content))
    }
  }

def tryProcessSource(
    file: File,
  parseLine: (String, Int) => List[String] = (line, index) => List(line),
  filterLine: (List[String], Int) => Boolean = (values, index) => true,
  retainValues: (List[String], Int) => List[String] = (values, index) => values,
  isFirstLineNotHeader: Boolean = false
): Try[List[List[String]]] =
  tryUsingSource(() => Source.fromFile(file)) { source =>
    Try(
      ( for {
          (line, index) <- source.getLines().buffered.zipWithIndex
          values = parseLine(line, index)
          if (index == 0 && !isFirstLineNotHeader) || filterLine(values, index)
          retainedValues = retainValues(values, index)
        } yield retainedValues
      ).toList
    )
  }

As a Scala/FP newbie, I've burned many hours (in mostly head-scratching frustration) earning the above knowledge and solutions. I hope this helps other Scala/FP newbies get over this particular learning hump faster.

Node.js project naming conventions for files & folders

There are no conventions. There are some logical structure.

The only one thing that I can say: Never use camelCase file and directory names. Why? It works but on Mac and Windows there are no different between someAction and some action. I met this problem, and not once. I require'd a file like this:

var isHidden = require('./lib/isHidden');

But sadly I created a file with full of lowercase: lib/ishidden.js. It worked for me on mac. It worked fine on mac of my co-worker. Tests run without errors. After deploy we got a huge error:

Error: Cannot find module './lib/isHidden'

Oh yeah. It's a linux box. So camelCase directory structure could be dangerous. It's enough for a colleague who is developing on Windows or Mac.

So use underscore (_) or dash (-) separator if you need.

Is there any advantage of using map over unordered_map in case of trivial keys?

Don't forget that map keeps its elements ordered. If you can't give that up, obviously you can't use unordered_map.

Something else to keep in mind is that unordered_map generally uses more memory. map just has a few house-keeping pointers, and memory for each object. Contrarily, unordered_map has a big array (these can get quite big in some implementations), and then additional memory for each object. If you need to be memory-aware, map should prove better, because it lacks the large array.

So, if you need pure lookup-retrieval, I'd say unordered_map is the way to go. But there are always trade-offs, and if you can't afford them, then you can't use it.

Just from personal experience, I found an enormous improvement in performance (measured, of course) when using unordered_map instead of map in a main entity look-up table.

On the other hand, I found it was much slower at repeatedly inserting and removing elements. It's great for a relatively static collection of elements, but if you're doing tons of insertions and deletions the hashing + bucketing seems to add up. (Note, this was over many iterations.)

Error TF30063: You are not authorized to access ... \DefaultCollection

If Rizowski's answer of clicking the green plug connect-button doesn't work and you have multiple workspaces, the problem might go away by switching to the other workspace and back again.

Day Name from Date in JS

let weekday = new Date(dateString).toLocaleString('en-us', {weekday:'long'});
console.log('Weekday',weekday);

Use of symbols '@', '&', '=' and '>' in custom directive's scope binding: AngularJS

< one-way binding

= two-way binding

& function binding

@ pass only strings

mysql query: SELECT DISTINCT column1, GROUP BY column2

you can use COUNT(DISTINCT ip), this will only count distinct values

How can I view an object with an alert()

you can use toSource method like this

alert(product.toSource());

Remove rows not .isin('X')

You can use the DataFrame.select method:

In [1]: df = pd.DataFrame([[1,2],[3,4]], index=['A','B'])

In [2]: df
Out[2]: 
   0  1
A  1  2
B  3  4

In [3]: L = ['A']

In [4]: df.select(lambda x: x in L)
Out[4]: 
   0  1
A  1  2

Simplest PHP example for retrieving user_timeline with Twitter API version 1.1

Important Note: As of mid-2018, the process to get twitter API tokens became a lot more bureaucratic. It has taken me over one working week to be provided a set of API tokens, and this is for an open source project for you guys and girls with over 1.2 million installations on Packagist and 1.6k stars on Github, which theoretically should be higher priority.

If you are tasked with working with the twitter API for your work, you must take this potentially extremely long wait-time into account. Also consider other social media avenues like Facebook or Instagram and provide these options, as the process for retrieving their tokens is instant.


So you want to use the Twitter v1.1 API?

Note: the files for these are on GitHub.

Version 1.0 will soon be deprecated and unauthorised requests won't be allowed. So, here's a post to help you do just that, along with a PHP class to make your life easier.

1. Create a developer account: Set yourself up a developer account on Twitter

You need to visit the official Twitter developer site and register for a developer account. This is a free and necessary step to make requests for the v1.1 API.

2. Create an application: Create an application on the Twitter developer site

What? You thought you could make unauthenticated requests? Not with Twitter's v1.1 API. You need to visit http://dev.twitter.com/apps and click the "Create Application" button.

Enter image description here

On this page, fill in whatever details you want. For me, it didn't matter, because I just wanted to make a load of block requests to get rid of spam followers. The point is you are going to get yourself a set of unique keys to use for your application.

So, the point of creating an application is to give yourself (and Twitter) a set of keys. These are:

  • The consumer key
  • The consumer secret
  • The access token
  • The access token secret

There's a little bit of information here on what these tokens for.

3. Create access tokens: You'll need these to make successful requests

OAuth requests a few tokens. So you need to have them generated for you.

Enter image description here

Click "create my access token" at the bottom. Then once you scroll to the bottom again, you'll have some newly generated keys. You need to grab the four previously labelled keys from this page for your API calls, so make a note of them somewhere.

4. Change access level: You don't want read-only, do you?

If you want to make any decent use of this API, you'll need to change your settings to Read & Write if you're doing anything other than standard data retrieval using GET requests.

Enter image description here

Choose the "Settings" tab near the top of the page.

Enter image description here

Give your application read / write access, and hit "Update" at the bottom.

You can read more about the applications permission model that Twitter uses here.


5. Write code to access the API: I've done most of it for you

I combined the code above, with some modifications and changes, into a PHP class so it's really simple to make the requests you require.

This uses OAuth and the Twitter v1.1 API, and the class I've created which you can find below.

require_once('TwitterAPIExchange.php');

/** Set access tokens here - see: https://dev.twitter.com/apps/ **/
$settings = array(
    'oauth_access_token' => "YOUR_OAUTH_ACCESS_TOKEN",
    'oauth_access_token_secret' => "YOUR_OAUTH_ACCESS_TOKEN_SECRET",
    'consumer_key' => "YOUR_CONSUMER_KEY",
    'consumer_secret' => "YOUR_CONSUMER_SECRET"
);

Make sure you put the keys you got from your application above in their respective spaces.

Next you need to choose a URL you want to make a request to. Twitter has their API documentation to help you choose which URL and also the request type (POST or GET).

/** URL for REST request, see: https://dev.twitter.com/docs/api/1.1/ **/
$url = 'https://api.twitter.com/1.1/blocks/create.json';
$requestMethod = 'POST';

In the documentation, each URL states what you can pass to it. If we're using the "blocks" URL like the one above, I can pass the following POST parameters:

/** POST fields required by the URL above. See relevant docs as above **/
$postfields = array(
    'screen_name' => 'usernameToBlock', 
    'skip_status' => '1'
);

Now that you've set up what you want to do with the API, it's time to make the actual request.

/** Perform the request and echo the response **/
$twitter = new TwitterAPIExchange($settings);
echo $twitter->buildOauth($url, $requestMethod)
             ->setPostfields($postfields)
             ->performRequest();

And for a POST request, that's it!

For a GET request, it's a little different. Here's an example:

/** Note: Set the GET field BEFORE calling buildOauth(); **/
$url = 'https://api.twitter.com/1.1/followers/ids.json';
$getfield = '?username=J7mbo';
$requestMethod = 'GET';
$twitter = new TwitterAPIExchange($settings);
echo $twitter->setGetfield($getfield)
             ->buildOauth($url, $requestMethod)
             ->performRequest();     

Final code example: For a simple GET request for a list of my followers.

$url = 'https://api.twitter.com/1.1/followers/list.json';
$getfield = '?username=J7mbo&skip_status=1';
$requestMethod = 'GET';
$twitter = new TwitterAPIExchange($settings);
echo $twitter->setGetfield($getfield)
             ->buildOauth($url, $requestMethod)
             ->performRequest();  

I've put these files on GitHub with credit to @lackovic10 and @rivers! I hope someone finds it useful; I know I did (I used it for bulk blocking in a loop).

Also, for those on Windows who are having problems with SSL certificates, look at this post. This library uses cURL under the hood so you need to make sure you have your cURL certs set up probably. Google is also your friend.

ActiveRecord: size vs count

Sometimes size "picks the wrong one" and returns a hash (which is what count would do)

In that case, use length to get an integer instead of hash.

How to "pretty" format JSON output in Ruby on Rails

Here's my solution which I derived from other posts during my own search.

This allows you to send the pp and jj output to a file as needed.

require "pp"
require "json"

class File
  def pp(*objs)
    objs.each {|obj|
      PP.pp(obj, self)
    }
    objs.size <= 1 ? objs.first : objs
  end
  def jj(*objs)
    objs.each {|obj|
      obj = JSON.parse(obj.to_json)
      self.puts JSON.pretty_generate(obj)
    }
    objs.size <= 1 ? objs.first : objs
  end
end

test_object = { :name => { first: "Christopher", last: "Mullins" }, :grades => [ "English" => "B+", "Algebra" => "A+" ] }

test_json_object = JSON.parse(test_object.to_json)

File.open("log/object_dump.txt", "w") do |file|
  file.pp(test_object)
end

File.open("log/json_dump.txt", "w") do |file|
  file.jj(test_json_object)
end

How to index an element of a list object in R

Indexing a list is done using double bracket, i.e. hypo_list[[1]] (e.g. have a look here: http://www.r-tutor.com/r-introduction/list). BTW: read.table does not return a table but a dataframe (see value section in ?read.table). So you will have a list of dataframes, rather than a list of table objects. The principal mechanism is identical for tables and dataframes though.

Note: In R, the index for the first entry is a 1 (not 0 like in some other languages).

Dataframes

l <- list(anscombe, iris)   # put dfs in list
l[[1]]             # returns anscombe dataframe

anscombe[1:2, 2]   # access first two rows and second column of dataset
[1] 10  8

l[[1]][1:2, 2]     # the same but selecting the dataframe from the list first
[1] 10  8

Table objects

tbl1 <- table(sample(1:5, 50, rep=T))
tbl2 <- table(sample(1:5, 50, rep=T))
l <- list(tbl1, tbl2)  # put tables in a list

tbl1[1:2]              # access first two elements of table 1 

Now with the list

l[[1]]                 # access first table from the list

1  2  3  4  5 
9 11 12  9  9 

l[[1]][1:2]            # access first two elements in first table

1  2 
9 11 

Read environment variables in Node.js

Why not use them in the Users directory in the .bash_profile file, so you don't have to push any files with your variables to production?

convert NSDictionary to NSString

Above Solutions will only convert dictionary into string but you can't convert back that string to dictionary. For that it is the better way.

Convert to String

NSError * err;
NSData * jsonData = [NSJSONSerialization  dataWithJSONObject:yourDictionary options:0 error:&err];
NSString * myString = [[NSString alloc] initWithData:jsonData   encoding:NSUTF8StringEncoding];
NSLog(@"%@",myString);

Convert Back to Dictionary

NSError * err;
NSData *data =[myString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary * response;
if(data!=nil){
 response = (NSDictionary *)[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&err];
}

Spring RestTemplate - how to enable full debugging/logging of requests/responses?

Best solution now, just add dependency :

<dependency>
  <groupId>com.github.zg2pro</groupId>
  <artifactId>spring-rest-basis</artifactId>
  <version>v.x</version>
</dependency>

It contains a LoggingRequestInterceptor class you can add that way to your RestTemplate:

integrate this utility by adding it as an interceptor to a spring RestTemplate, in the following manner:

restTemplate.setRequestFactory(LoggingRequestFactoryFactory.build());

and add an slf4j implementation to your framework like log4j.

or directly use "Zg2proRestTemplate". The "best answer" by @PaulSabou looks so so, since httpclient and all apache.http libs are not necessarily loaded when using a spring RestTemplate.

How do I rename a repository on GitHub?

If you are the only person working on the project, it's not a big problem, because you only have to do #2.

Let's say your username is someuser and your project is called someproject.

Then your project's URL will be1

[email protected]:someuser/someproject.git

If you rename your project, it will change the someproject part of the URL, e.g.

[email protected]:someuser/newprojectname.git

(see footnote if your URL does not look like this).

Your working copy of Git uses this URL when you do a push or pull.

So after you rename your project, you will have to tell your working copy the new URL.

You can do that in two steps:

Firstly, cd to your local Git directory, and find out what remote name(s) refer to that URL:

$ git remote -v
origin  [email protected]:someuser/someproject.git

Then, set the new URL

$ git remote set-url origin [email protected]:someuser/newprojectname.git

Or in older versions of Git, you might need:

$ git remote rm origin
$ git remote add origin [email protected]:someuser/newprojectname.git

(origin is the most common remote name, but it might be called something else.)

But if there are lots of people who are working on your project, they will all need to do the above steps, and maybe you don't even know how to contact them all to tell them. That's what #1 is about.

Further reading:

Footnotes:

1 The exact format of your URL depends on which protocol you are using, e.g.

Credentials for the SQL Server Agent service are invalid

I solved using as credential built-in accounts as the NetworkService this article point me out in the right direction http://www.sqlcoffee.com/SQLServer2008_0013.htm

How to clone an InputStream?

UPD. Check the comment before. It isn't exactly what was asked.

If you are using apache.commons you may copy streams using IOUtils .

You can use following code:

InputStream = IOUtils.toBufferedInputStream(toCopy);

Here is the full example suitable for your situation:

public void cloneStream() throws IOException{
    InputStream toCopy=IOUtils.toInputStream("aaa");
    InputStream dest= null;
    dest=IOUtils.toBufferedInputStream(toCopy);
    toCopy.close();
    String result = new String(IOUtils.toByteArray(dest));
    System.out.println(result);
}

This code requires some dependencies:

MAVEN

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.4</version>
</dependency>

GRADLE

'commons-io:commons-io:2.4'

Here is the DOC reference for this method:

Fetches entire contents of an InputStream and represent same data as result InputStream. This method is useful where,

Source InputStream is slow. It has network resources associated, so we cannot keep it open for long time. It has network timeout associated.

You can find more about IOUtils here: http://commons.apache.org/proper/commons-io/javadocs/api-2.4/org/apache/commons/io/IOUtils.html#toBufferedInputStream(java.io.InputStream)

OnclientClick and OnClick is not working at the same time?

function UpdateClick(btn) {

    for (i = 0; i < Page_Validators.length; i++) {

        ValidatorValidate(Page_Validators[i]);

        if (Page_Validators[i].isvalid == false)

            return false;
    }

    btn.disabled = 'false';

    btn.value = 'Please Wait...';

    return true;
}

How do you implement a re-try-catch?

You can use AOP and Java annotations from jcabi-aspects (I'm a developer):

@RetryOnFailure(attempts = 3, delay = 5)
public String load(URL url) {
  return url.openConnection().getContent();
}

You could also use @Loggable and @LogException annotations.

Do you use NULL or 0 (zero) for pointers in C++?

I'm with Stroustrup on this one :-) Since NULL is not part of the language, I prefer to use 0.

Is there a limit to the length of a GET request?

The specification does not limit the length of an HTTP Get request but the different browsers implement their own limitations. For example Internet Explorer has a limitation implemented at 2083 characters.

Component based game engine design

While not a complete tutorial on the subject of game engine design, I have found that this page has some good detail and examples on use of the component architecture for games.

How do I base64 encode (decode) in C?

The EVP_EncodeBlock and EVP_DecodeBlock functions make it very easy:

#include <stdio.h>
#include <stdlib.h>
#include <openssl/evp.h>

char *base64(const unsigned char *input, int length) {
  const int pl = 4*((length+2)/3);
  char *output = calloc(pl+1, 1); //+1 for the terminating null that EVP_EncodeBlock adds on
  const int ol = EVP_EncodeBlock(output, input, length);
  if (ol != pl) { fprintf(stderr, "Whoops, encode predicted %d but we got %d\n", pl, ol); }
  return output;
}

unsigned char *decode64(const char *input, int length) {
  const int pl = 3*length/4;
  unsigned char *output = calloc(pl+1, 1);
  const int ol = EVP_DecodeBlock(output, input, length);
  if (pl != ol) { fprintf(stderr, "Whoops, decode predicted %d but we got %d\n", pl, ol); }
  return output;
}

How do I format a number with commas in T-SQL?

For SQL Server before 2012 which does not include the FORMAT function, create this function:

CREATE FUNCTION FormatCurrency(@value numeric(30,2))
    RETURNS varchar(50)
    AS
    BEGIN
        DECLARE @NumAsChar VARCHAR(50)
        SET @NumAsChar = '$' + CONVERT(varchar(50), CAST(@Value AS money),1)
        RETURN @NumAsChar
    END 

select dbo.FormatCurrency(12345678) returns $12,345,678.00

Drop the $ if you just want commas.

make bootstrap twitter dialog modal draggable

$("#myModal").draggable({
    handle: ".modal-header"
}); 

it works for me. I got it from there. if you give me thanks please give 70% to Andres Ilich

How to detect the character encoding of a text file?

You can't depend on the file having a BOM. UTF-8 doesn't require it. And non-Unicode encodings don't even have a BOM. There are, however, other ways to detect the encoding.

UTF-32

BOM is 00 00 FE FF (for BE) or FF FE 00 00 (for LE).

But UTF-32 is easy to detect even without a BOM. This is because the Unicode code point range is restricted to U+10FFFF, and thus UTF-32 units always have the pattern 00 {00-10} xx xx (for BE) or xx xx {00-10} 00 (for LE). If the data has a length that's a multiple of 4, and follows one of these patterns, you can safely assume it's UTF-32. False positives are nearly impossible due to the rarity of 00 bytes in byte-oriented encodings.

US-ASCII

No BOM, but you don't need one. ASCII can be easily identified by the lack of bytes in the 80-FF range.

UTF-8

BOM is EF BB BF. But you can't rely on this. Lots of UTF-8 files don't have a BOM, especially if they originated on non-Windows systems.

But you can safely assume that if a file validates as UTF-8, it is UTF-8. False positives are rare.

Specifically, given that the data is not ASCII, the false positive rate for a 2-byte sequence is only 3.9% (1920/49152). For a 7-byte sequence, it's less than 1%. For a 12-byte sequence, it's less than 0.1%. For a 24-byte sequence, it's less than 1 in a million.

UTF-16

BOM is FE FF (for BE) or FF FE (for LE). Note that the UTF-16LE BOM is found at the start of the UTF-32LE BOM, so check UTF-32 first.

If you happen to have a file that consists mainly of ISO-8859-1 characters, having half of the file's bytes be 00 would also be a strong indicator of UTF-16.

Otherwise, the only reliable way to recognize UTF-16 without a BOM is to look for surrogate pairs (D[8-B]xx D[C-F]xx), but non-BMP characters are too rarely-used to make this approach practical.

XML

If your file starts with the bytes 3C 3F 78 6D 6C (i.e., the ASCII characters "<?xml"), then look for an encoding= declaration. If present, then use that encoding. If absent, then assume UTF-8, which is the default XML encoding.

If you need to support EBCDIC, also look for the equivalent sequence 4C 6F A7 94 93.

In general, if you have a file format that contains an encoding declaration, then look for that declaration rather than trying to guess the encoding.

None of the above

There are hundreds of other encodings, which require more effort to detect. I recommend trying Mozilla's charset detector or a .NET port of it.

A reasonable default

If you've ruled out the UTF encodings, and don't have an encoding declaration or statistical detection that points to a different encoding, assume ISO-8859-1 or the closely related Windows-1252. (Note that the latest HTML standard requires a “ISO-8859-1” declaration to be interpreted as Windows-1252.) Being Windows' default code page for English (and other popular languages like Spanish, Portuguese, German, and French), it's the most commonly encountered encoding other than UTF-8.

How to compile Go program consisting of multiple files?

It depends on your project structure. But most straightforward is:

go build -o ./myproject ./...

then run ./myproject.

Suppose your project structure looks like this

- hello
|- main.go

then you just go to the project directory and run

go build -o ./myproject

then run ./myproject on shell.

or

# most easiest; builds and run simultaneously
go run main.go

suppose your main file is nested into a sub-directory like a cmd

- hello
|- cmd
 |- main.go

then you will run

go run cmd/main.go

Creating new database from a backup of another Database on the same server?

I think that is easier than this.

  • First, create a blank target database.
  • Then, in "SQL Server Management Studio" restore wizard, look for the option to overwrite target database. It is in the 'Options' tab and is called 'Overwrite the existing database (WITH REPLACE)'. Check it.
  • Remember to select target files in 'Files' page.

You can change 'tabs' at left side of the wizard (General, Files, Options)

Java ArrayList for integers

Actually what u did is also not wrong your declaration is right . With your declaration JVM will create a ArrayList of integer arrays i.e each entry in arraylist correspond to an integer array hence your add function should pass a integer array as a parameter.

For Ex:

list.add(new Integer[3]);

In this way first entry of ArrayList is an integer array which can hold at max 3 values.

How to change color of Android ListView separator line?

Use below code in your xml file

<ListView 
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="#000000" 
    android:dividerHeight="1dp">
</ListView> 

Show history of a file?

Have you tried this:

gitk path/to/file

Can you recommend a free light-weight MySQL GUI for Linux?

I really like the MySQL collection of of GUI Tools. They aren't too large or resource hungry.

There are quite a few options here as well. Of the applications presented on that page, I like SQL Buddy - it does require a web server, however.

How to get query string parameter from MVC Razor markup?

It was suggested to post this as an answer, because some other answers are giving errors like 'The name Context does not exist in the current context'.

Just using the following works:

Request.Query["queryparm1"]

Sample usage:

<a href="@Url.Action("Query",new {parm1=Request.Query["queryparm1"]})">GO</a>

Understanding Spring @Autowired usage

Yes, you can configure the Spring servlet context xml file to define your beans (i.e., classes), so that it can do the automatic injection for you. However, do note, that you have to do other configurations to have Spring up and running and the best way to do that, is to follow a tutorial ground up.

Once you have your Spring configured probably, you can do the following in your Spring servlet context xml file for Example 1 above to work (please replace the package name of com.movies to what the true package name is and if this is a 3rd party class, then be sure that the appropriate jar file is on the classpath) :

<beans:bean id="movieFinder" class="com.movies.MovieFinder" />

or if the MovieFinder class has a constructor with a primitive value, then you could something like this,

<beans:bean id="movieFinder" class="com.movies.MovieFinder" >
    <beans:constructor-arg value="100" />
</beans:bean>

or if the MovieFinder class has a constructor expecting another class, then you could do something like this,

<beans:bean id="movieFinder" class="com.movies.MovieFinder" >
    <beans:constructor-arg ref="otherBeanRef" />
</beans:bean>

...where 'otherBeanRef' is another bean that has a reference to the expected class.

Is there any way to redraw tmux window when switching smaller monitor to bigger one?

This is still the top post when searching, but it's no longer valid. Best answer is here, but the TLDR is

<c-b>:resize-window -A

Running Selenium WebDriver python bindings in chrome

You need to make sure the standalone ChromeDriver binary (which is different than the Chrome browser binary) is either in your path or available in the webdriver.chrome.driver environment variable.

see http://code.google.com/p/selenium/wiki/ChromeDriver for full information on how wire things up.

Edit:

Right, seems to be a bug in the Python bindings wrt reading the chromedriver binary from the path or the environment variable. Seems if chromedriver is not in your path you have to pass it in as an argument to the constructor.

import os
from selenium import webdriver

chromedriver = "/Users/adam/Downloads/chromedriver"
os.environ["webdriver.chrome.driver"] = chromedriver
driver = webdriver.Chrome(chromedriver)
driver.get("http://stackoverflow.com")
driver.quit()

What to use now Google News API is deprecated?

I'm running into the same issue with one of my own apps. So far I've found the only non-deprecated way to access Google News data is through their RSS feeds. They have a feed for each section and also a useful search function. However, these are only for noncommercial use.

As for viable alternatives I'll be trying out these two services: Feedzilla, Daylife

How to iterate over array of objects in Handlebars?

I meant in the template() call..

You just need to pass the results as an object. So instead of calling

var html = template(data);

do

var html = template({apidata: data});

and use {{#each apidata}} in your template code

demo at http://jsfiddle.net/KPCh4/4/
(removed some leftover if code that crashed)

Reading in a JSON File Using Swift

This worked great with me

func readjson(fileName: String) -> NSData{

    let path = NSBundle.mainBundle().pathForResource(fileName, ofType: "json")
    let jsonData = NSData(contentsOfMappedFile: path!)

    return jsonData!
}

Fastest way to serialize and deserialize .NET objects

The binary serializer included with .net should be faster that the XmlSerializer. Or another serializer for protobuf, json, ...

But for some of them you need to add Attributes, or some other way to add metadata. For example ProtoBuf uses numeric property IDs internally, and the mapping needs to be somehow conserved by a different mechanism. Versioning isn't trivial with any serializer.

Java String remove all non numeric characters

This handles null inputs, negative numbers and decimals (you need to include the Apache Commons Lang library, version 3.8 or higher, in your project):

import org.apache.commons.lang3.RegExUtils;
result = RegExUtils.removeAll(input, "-?[^\\d.]");

Library reference: https://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/RegExUtils.html

Get-WmiObject : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)

I found this blog post which suggested adding a firewall exception for "Remote Administration", and that worked for us on our Windows Server 2008 Enterprise systems.

http://mikefrobbins.com/2012/03/08/get-wmiobject-the-rpc-server-is-unavailable-exception-from-hresult-0x800706ba/

Difference between "git add -A" and "git add ."

git add . equals git add -A . adds files to index only from current and children folders.

git add -A adds files to index from all folders in working tree.

P.S.: information relates to Git 2.0 (2014-05-28).

Spring Boot: How can I set the logging level with application.properties?

In case you want to use a different logging framework, log4j for example, I found the easiest approach is to disable spring boots own logging and implement your own. That way I can configure every loglevel within one file, log4j.xml (in my case) that is.

To achieve this you simply have to add those lines to your pom.xml:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j</artifactId>
</dependency>

You probably already have the first dependency and only need the other two. Please note, that this example only covers log4j.
That's all, now you're all set to configure logging for boot within your log4j config file!

Extracting .jar file with command line

jar xf myFile.jar
change myFile to name of your file
this will save the contents in the current folder of .jar file
that should do :)

How to get file name when user select a file via <input type="file" />?

I'll answer this question via Simple Javascript that is supported in all browsers that I have tested so far (IE8 to IE11, Chrome, FF etc).

Here is the code.

_x000D_
_x000D_
function GetFileSizeNameAndType()_x000D_
        {_x000D_
        var fi = document.getElementById('file'); // GET THE FILE INPUT AS VARIABLE._x000D_
_x000D_
        var totalFileSize = 0;_x000D_
_x000D_
        // VALIDATE OR CHECK IF ANY FILE IS SELECTED._x000D_
        if (fi.files.length > 0)_x000D_
        {_x000D_
            // RUN A LOOP TO CHECK EACH SELECTED FILE._x000D_
            for (var i = 0; i <= fi.files.length - 1; i++)_x000D_
            {_x000D_
                //ACCESS THE SIZE PROPERTY OF THE ITEM OBJECT IN FILES COLLECTION. IN THIS WAY ALSO GET OTHER PROPERTIES LIKE FILENAME AND FILETYPE_x000D_
                var fsize = fi.files.item(i).size;_x000D_
                totalFileSize = totalFileSize + fsize;_x000D_
                document.getElementById('fp').innerHTML =_x000D_
                document.getElementById('fp').innerHTML_x000D_
                +_x000D_
                '<br /> ' + 'File Name is <b>' + fi.files.item(i).name_x000D_
                +_x000D_
                '</b> and Size is <b>' + Math.round((fsize / 1024)) //DEFAULT SIZE IS IN BYTES SO WE DIVIDING BY 1024 TO CONVERT IT IN KB_x000D_
                +_x000D_
                '</b> KB and File Type is <b>' + fi.files.item(i).type + "</b>.";_x000D_
            }_x000D_
        }_x000D_
        document.getElementById('divTotalSize').innerHTML = "Total File(s) Size is <b>" + Math.round(totalFileSize / 1024) + "</b> KB";_x000D_
    }
_x000D_
    <p>_x000D_
        <input type="file" id="file" multiple onchange="GetFileSizeNameAndType()" />_x000D_
    </p>_x000D_
_x000D_
    <div id="fp"></div>_x000D_
    <p>_x000D_
        <div id="divTotalSize"></div>_x000D_
    </p>
_x000D_
_x000D_
_x000D_

*Please note that we are displaying filesize in KB (Kilobytes). To get in MB divide it by 1024 * 1024 and so on*.

It'll perform file outputs like these on selecting Snapshot of a sample output of this code

How to extract 1 screenshot for a video with ffmpeg at a given time?

Use the -ss option:

ffmpeg -ss 01:23:45 -i input -vframes 1 -q:v 2 output.jpg
  • For JPEG output use -q:v to control output quality. Full range is a linear scale of 1-31 where a lower value results in a higher quality. 2-5 is a good range to try.

  • The select filter provides an alternative method for more complex needs such as selecting only certain frame types, or 1 per 100, etc.

  • Placing -ss before the input will be faster. See FFmpeg Wiki: Seeking and this excerpt from the ffmpeg cli tool documentation:

-ss position (input/output)

When used as an input option (before -i), seeks in this input file to position. Note the in most formats it is not possible to seek exactly, so ffmpeg will seek to the closest seek point before position. When transcoding and -accurate_seek is enabled (the default), this extra segment between the seek point and position will be decoded and discarded. When doing stream copy or when -noaccurate_seek is used, it will be preserved.

When used as an output option (before an output filename), decodes but discards input until the timestamps reach position.

position may be either in seconds or in hh:mm:ss[.xxx] form.

How to filter rows in pandas by regex

It may be a bit late, but this is now easier to do in Pandas by calling Series.str.match. The docs explain the difference between match, fullmatch and contains.

Note that in order to use the results for indexing, set the na=False argument (or True if you want to include NANs in the results).

File opens instead of downloading in internet explorer in a href link

For apache2 server:

AddType application/octect-stream .ova

File location will depend on particular version of Apache2 -- ours is in /etc/apache2/mods-available/mime.conf

Reference:

https://askubuntu.com/questions/610645/how-to-configure-apache2-to-download-files-directly

base_url() function not working in codeigniter

If you don't want to use the url helper, you can get the same results by using the following variable:

$this->config->config['base_url']

It will return the base url for you with no extra steps required.

AngularJS : automatically detect change in model

In views with {{}} and/or ng-model, Angular is setting up $watch()es for you behind the scenes.

By default $watch compares by reference. If you set the third parameter to $watch to true, Angular will instead "shallow" watch the object for changes. For arrays this means comparing the array items, for object maps this means watching the properties. So this should do what you want:

$scope.$watch('myModel', function() { ... }, true);

Update: Angular v1.2 added a new method for this, `$watchCollection():

$scope.$watchCollection('myModel', function() { ... });

Note that the word "shallow" is used to describe the comparison rather than "deep" because references are not followed -- e.g., if the watched object contains a property value that is a reference to another object, that reference is not followed to compare the other object.

OpenSSL: unable to verify the first certificate for Experian URL

Adding additional information to emboss's answer.

To put it simply, there is an incorrect cert in your certificate chain.

For example, your certificate authority will have most likely given you 3 files.

  • your_domain_name.crt
  • DigiCertCA.crt # (Or whatever the name of your certificate authority is)
  • TrustedRoot.crt

You most likely combined all of these files into one bundle.

-----BEGIN CERTIFICATE----- 
(Your Primary SSL certificate: your_domain_name.crt) 
-----END CERTIFICATE----- 
-----BEGIN CERTIFICATE----- 
(Your Intermediate certificate: DigiCertCA.crt) 
-----END CERTIFICATE----- 
-----BEGIN CERTIFICATE----- 
(Your Root certificate: TrustedRoot.crt) 
-----END CERTIFICATE-----

If you create the bundle, but use an old, or an incorrect version of your Intermediate Cert (DigiCertCA.crt in my example), you will get the exact symptoms you are describing.

Redownload all certs from your certificate authority and make a fresh bundle.

Group by & count function in sqlalchemy

If you are using Table.query property:

from sqlalchemy import func
Table.query.with_entities(Table.column, func.count(Table.column)).group_by(Table.column).all()

If you are using session.query() method (as stated in miniwark's answer):

from sqlalchemy import func
session.query(Table.column, func.count(Table.column)).group_by(Table.column).all()

Split a vector into chunks

Sorry if this answer comes so late, but maybe it can be useful for someone else. Actually there is a very useful solution to this problem, explained at the end of ?split.

> testVector <- c(1:10) #I want to divide it into 5 parts
> VectorList <- split(testVector, 1:5)
> VectorList
$`1`
[1] 1 6

$`2`
[1] 2 7

$`3`
[1] 3 8

$`4`
[1] 4 9

$`5`
[1]  5 10

Set focus on <input> element

Modify the show search method like this

showSearch(){
  this.show = !this.show;  
  setTimeout(()=>{ // this will make the execution after the above boolean has changed
    this.searchElement.nativeElement.focus();
  },0);  
}

Error 1022 - Can't write; duplicate key in table

I also encountered that problem.Check if database name already exist in Mysql,and rename the old one.

How do you sort a dictionary by value?

You do not sort entries in the Dictionary. Dictionary class in .NET is implemented as a hashtable - this data structure is not sortable by definition.

If you need to be able to iterate over your collection (by key) - you need to use SortedDictionary, which is implemented as a Binary Search Tree.

In your case, however the source structure is irrelevant, because it is sorted by a different field. You would still need to sort it by frequency and put it in a new collection sorted by the relevant field (frequency). So in this collection the frequencies are keys and words are values. Since many words can have the same frequency (and you are going to use it as a key) you cannot use neither Dictionary nor SortedDictionary (they require unique keys). This leaves you with a SortedList.

I don't understand why you insist on maintaining a link to the original item in your main/first dictionary.

If the objects in your collection had a more complex structure (more fields) and you needed to be able to efficiently access/sort them using several different fields as keys - You would probably need a custom data structure that would consist of the main storage that supports O(1) insertion and removal (LinkedList) and several indexing structures - Dictionaries/SortedDictionaries/SortedLists. These indexes would use one of the fields from your complex class as a key and a pointer/reference to the LinkedListNode in the LinkedList as a value.

You would need to coordinate insertions and removals to keep your indexes in sync with the main collection (LinkedList) and removals would be pretty expensive I'd think. This is similar to how database indexes work - they are fantastic for lookups but they become a burden when you need to perform many insetions and deletions.

All of the above is only justified if you are going to do some look-up heavy processing. If you only need to output them once sorted by frequency then you could just produce a list of (anonymous) tuples:

var dict = new SortedDictionary<string, int>();
// ToDo: populate dict

var output = dict.OrderBy(e => e.Value).Select(e => new {frequency = e.Value, word = e.Key}).ToList();

foreach (var entry in output)
{
    Console.WriteLine("frequency:{0}, word: {1}",entry.frequency,entry.word);
}

CSS two divs next to each other

This won't be the answer for everyone, since it is not supported in IE7-, but you could use it and then use an alternate answer for IE7-. It is display: table, display: table-row and display: table-cell. Note that this is not using tables for layout, but styling divs so that things line up nicely with out all the hassle from above. Mine is an html5 app, so it works great.

This article shows an example: http://www.sitepoint.com/table-based-layout-is-the-next-big-thing/

Here is what your stylesheet will look like:

 .container {
    display: table;
    width:100%;
 }

 .left-column {
    display: table-cell;
 }

 .right-column {
    display: table-cell;
    width: 200px;
 }

WPF Image Dynamically changing Image source during runtime

Hey, this one is kind of ugly but it's one line only:

imgTitle.Source = new BitmapImage(new Uri(@"pack://application:,,,/YourAssembly;component/your_image.png"));

Is it possible to access to google translate api for free?

Yes, you can use GT for free. See the post with explanation. And look at repo on GitHub.

UPD 19.03.2019 Here is a version for browser on GitHub.

How do I use modulus for float/double?

fmod is the standard C function for handling floating-point modulus; I imagine your source was saying that Java handles floating-point modulus the same as C's fmod function. In Java you can use the % operator on doubles the same as on integers:

int x = 5 % 3; // x = 2
double y = .5 % .3; // y = .2

When to throw an exception?

I have three type of conditions that I catch.

  1. Bad or missing input should not be an exception. Use both client side js and server side regex to detect, set attributes and forward back to the same page with messages.

  2. The AppException. This is usually an exception that you detect and throw with in your code. In other words these are ones you expect (the file does not exist). Log it, set the message, and forward back to the general error page. This page usually has a bit of info about what happened.

  3. The unexpected Exception. These are the ones you don't know about. Log it with details and forward them to a general error page.

Hope this helps

Replacing all non-alphanumeric characters with empty strings

Guava's CharMatcher provides a concise solution:

output = CharMatcher.javaLetterOrDigit().retainFrom(input);

Unable to resolve host "<insert URL here>" No address associated with hostname

I got the same error and for the issue was that I was on VPN and I didn't realize that. After disconnecting the VPN and reconnecting the wifi resolved it.

Dynamic creation of table with DOM

It is because you're only creating two td elements and 2 text nodes.


Creating all nodes in a loop

Recreate the nodes inside your loop:

var tablearea = document.getElementById('tablearea'),
    table = document.createElement('table');

for (var i = 1; i < 4; i++) {
    var tr = document.createElement('tr');

    tr.appendChild( document.createElement('td') );
    tr.appendChild( document.createElement('td') );

    tr.cells[0].appendChild( document.createTextNode('Text1') )
    tr.cells[1].appendChild( document.createTextNode('Text2') );

    table.appendChild(tr);
}

tablearea.appendChild(table);

Creating then cloning in a loop

Create them beforehand, and clone them inside the loop:

var tablearea = document.getElementById('tablearea'),
    table = document.createElement('table'),
    tr = document.createElement('tr');

tr.appendChild( document.createElement('td') );
tr.appendChild( document.createElement('td') );

tr.cells[0].appendChild( document.createTextNode('Text1') )
tr.cells[1].appendChild( document.createTextNode('Text2') );

for (var i = 1; i < 4; i++) {
    table.appendChild(tr.cloneNode( true ));
}

tablearea.appendChild(table);

Table factory with text string

Make a table factory:

function populateTable(table, rows, cells, content) {
    if (!table) table = document.createElement('table');
    for (var i = 0; i < rows; ++i) {
        var row = document.createElement('tr');
        for (var j = 0; j < cells; ++j) {
            row.appendChild(document.createElement('td'));
            row.cells[j].appendChild(document.createTextNode(content + (j + 1)));
        }
        table.appendChild(row);
    }
    return table;
}

And use it like this:

document.getElementById('tablearea')
        .appendChild( populateTable(null, 3, 2, "Text") );

Table factory with text string or callback

The factory could easily be modified to accept a function as well for the fourth argument in order to populate the content of each cell in a more dynamic manner.

function populateTable(table, rows, cells, content) {
    var is_func = (typeof content === 'function');
    if (!table) table = document.createElement('table');
    for (var i = 0; i < rows; ++i) {
        var row = document.createElement('tr');
        for (var j = 0; j < cells; ++j) {
            row.appendChild(document.createElement('td'));
            var text = !is_func ? (content + '') : content(table, i, j);
            row.cells[j].appendChild(document.createTextNode(text));
        }
        table.appendChild(row);
    }
    return table;
}

Used like this:

document.getElementById('tablearea')
        .appendChild(populateTable(null, 3, 2, function(t, r, c) {
                        return ' row: ' + r + ', cell: ' + c;
                     })
        );

How should I copy Strings in Java?

Strings are immutable objects so you can copy them just coping the reference to them, because the object referenced can't change ...

So you can copy as in your first example without any problem :

String s = "hello";
String backup_of_s = s;
s = "bye";

onMeasure custom view explanation

If you don't need to change something onMeasure - there's absolutely no need for you to override it.

Devunwired code (the selected and most voted answer here) is almost identical to what the SDK implementation already does for you (and I checked - it had done that since 2009).

You can check the onMeasure method here :

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
            getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec));
}

public static int getDefaultSize(int size, int measureSpec) {
    int result = size;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);

    switch (specMode) {
    case MeasureSpec.UNSPECIFIED:
        result = size;
        break;
    case MeasureSpec.AT_MOST:
    case MeasureSpec.EXACTLY:
        result = specSize;
        break;
    }
    return result;
}

Overriding SDK code to be replaced with the exact same code makes no sense.

This official doc's piece that claims "the default onMeasure() will always set a size of 100x100" - is wrong.

If conditions in a Makefile, inside a target

You can simply use shell commands. If you want to suppress echoing the output, use the "@" sign. For example:

clean:
    @if [ "test" = "test" ]; then\
        echo "Hello world";\
    fi

Note that the closing ";" and "\" are necessary.

The system cannot find the file specified. in Visual Studio

Oh my days!!

Feel so embarrassed but it is my first day on the C++.

I was getting the error because of two things.

  1. I opened an empty project

  2. I didn't add #include "stdafx.h"

It ran successfully on the win 32 console.

Generating Random Passwords

I know that this is an old thread, but I have what might be a fairly simple solution for someone to use. Easy to implement, easy to understand, and easy to validate.

Consider the following requirement:

I need a random password to be generated which has at least 2 lower-case letters, 2 upper-case letters and 2 numbers. The password must also be a minimum of 8 characters in length.

The following regular expression can validate this case:

^(?=\b\w*[a-z].*[a-z]\w*\b)(?=\b\w*[A-Z].*[A-Z]\w*\b)(?=\b\w*[0-9].*[0-9]\w*\b)[a-zA-Z0-9]{8,}$

It's outside the scope of this question - but the regex is based on lookahead/lookbehind and lookaround.

The following code will create a random set of characters which match this requirement:

public static string GeneratePassword(int lowercase, int uppercase, int numerics) {
    string lowers = "abcdefghijklmnopqrstuvwxyz";
    string uppers = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string number = "0123456789";

    Random random = new Random();

    string generated = "!";
    for (int i = 1; i <= lowercase; i++)
        generated = generated.Insert(
            random.Next(generated.Length), 
            lowers[random.Next(lowers.Length - 1)].ToString()
        );

    for (int i = 1; i <= uppercase; i++)
        generated = generated.Insert(
            random.Next(generated.Length), 
            uppers[random.Next(uppers.Length - 1)].ToString()
        );

    for (int i = 1; i <= numerics; i++)
        generated = generated.Insert(
            random.Next(generated.Length), 
            number[random.Next(number.Length - 1)].ToString()
        );

    return generated.Replace("!", string.Empty);

}

To meet the above requirement, simply call the following:

String randomPassword = GeneratePassword(3, 3, 3);

The code starts with an invalid character ("!") - so that the string has a length into which new characters can be injected.

It then loops from 1 to the # of lowercase characters required, and on each iteration, grabs a random item from the lowercase list, and injects it at a random location in the string.

It then repeats the loop for uppercase letters and for numerics.

This gives you back strings of length = lowercase + uppercase + numerics into which lowercase, uppercase and numeric characters of the count you want have been placed in a random order.

Retaining file permissions with Git

Git is Version Control System, created for software development, so from the whole set of modes and permissions it stores only executable bit (for ordinary files) and symlink bit. If you want to store full permissions, you need third party tool, like git-cache-meta (mentioned by VonC), or Metastore (used by etckeeper). Or you can use IsiSetup, which IIRC uses git as backend.

See Interfaces, frontends, and tools page on Git Wiki.

Convert R vector to string vector of 1 element

Use the collapse argument to paste:

paste(a,collapse=" ")
[1] "aa bb cc"