Programs & Examples On #Achievements

In video gaming, an achievement is a meta-goal defined outside of a game's parameters. Achievements may be implemented by a platform, or solely within the game itself.

Notice: Trying to get property of non-object error

The response is an array.

var_dump($pjs[0]->{'player_name'});

Twitter bootstrap scrollable table

.span3 {  
    height: 100px !important;
    overflow: scroll;
}?

You'll want to wrap it in it's own div or give that span3 an id of it's own so you don't affect your whole layout.

Here's a fiddle: http://jsfiddle.net/zm6rf/

Transfer data from one database to another database

You can use visual studio 2015. Go to Tools => SQL server => New Data comparison

Select source and target Database.

How do I know the script file name in a Bash script?

me=`basename "$0"`

For reading through a symlink1, which is usually not what you want (you usually don't want to confuse the user this way), try:

me="$(basename "$(test -L "$0" && readlink "$0" || echo "$0")")"

IMO, that'll produce confusing output. "I ran foo.sh, but it's saying I'm running bar.sh!? Must be a bug!" Besides, one of the purposes of having differently-named symlinks is to provide different functionality based on the name it's called as (think gzip and gunzip on some platforms).


1 That is, to resolve symlinks such that when the user executes foo.sh which is actually a symlink to bar.sh, you wish to use the resolved name bar.sh rather than foo.sh.

How to open a website when a Button is clicked in Android application?

You can wrap the buttons in anchors that href to the appropriate website.

<a href="http://www.stackoverflow.com">
  <input type="button" value="Button" />
</a>
<a href="http://www.stackoverflow.com">
  <input type="button" value="Button" />
</a>
<a href="http://www.stackoverflow.com">
  <input type="button" value="Button" />
</a>

When the user clicks the button (input) they are directed to the destination specified in the href property of the anchor.

Edit: Oops, I didn't read "Eclipse" in the question title. My mistake.

Automating the InvokeRequired code pattern

You could write an extension method:

public static void InvokeIfRequired(this Control c, Action<Control> action)
{
    if(c.InvokeRequired)
    {
        c.Invoke(new Action(() => action(c)));
    }
    else
    {
        action(c);
    }
}

And use it like this:

object1.InvokeIfRequired(c => { c.Visible = true; });

EDIT: As Simpzon points out in the comments you could also change the signature to:

public static void InvokeIfRequired<T>(this T c, Action<T> action) 
    where T : Control

Conditional Binding: if let error – Initializer for conditional binding must have Optional type

condition binding must have optinal type which mean that you can only bind optional values in if let statement

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {

    if editingStyle == .delete {

        // Delete the row from the data source

        if let tv = tableView as UITableView? {


        }
    }
}

This will work fine but make sure when you use if let it must have optinal type "?"

<xsl:variable> Print out value of XSL variable using <xsl:value-of>

Your main problem is thinking that the variable you declared outside of the template is the same variable being "set" inside the choose statement. This is not how XSLT works, the variable cannot be reassigned. This is something more like what you want:

<xsl:template match="class">
  <xsl:copy><xsl:apply-templates select="@*|node()"/></xsl:copy>
  <xsl:variable name="subexists">
    <xsl:choose>
      <xsl:when test="joined-subclass">true</xsl:when>
      <xsl:otherwise>false</xsl:otherwise>
    </xsl:choose>
  </xsl:variable>
  subexists:      <xsl:value-of select="$subexists" />
</xsl:template>

And if you need the variable to have "global" scope then declare it outside of the template:

<xsl:variable name="subexists">
  <xsl:choose>
     <xsl:when test="/path/to/node/joined-subclass">true</xsl:when>
     <xsl:otherwise>false</xsl:otherwise>
  </xsl:choose>
</xsl:variable>

<xsl:template match="class">
   subexists:      <xsl:value-of select="$subexists" />
</xsl:template>

Pretty git branch graphs

In addition to the answer of 'Slipp D. Thompson', I propose you to add this alias to have the same decoration but in a single line by commit :

git config --global alias.tre "log --graph --decorate --pretty=oneline --abbrev-commit --all --format=format:'%C(bold blue)%h%C(reset) - %C(bold green)(%ar)%C(reset) %C(white)%s%C(reset) %C(dim white)- %an%C(reset)%C(bold yellow)%d%C(reset)'"

Quick Sort Vs Merge Sort

Quick sort is typically faster than merge sort when the data is stored in memory. However, when the data set is huge and is stored on external devices such as a hard drive, merge sort is the clear winner in terms of speed. It minimizes the expensive reads of the external drive and also lends itself well to parallel computing.

Postgresql SELECT if string contains

You should use 'tag_name' outside of quotes; then its interpreted as a field of the record. Concatenate using '||' with the literal percent signs:

SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' LIKE '%' || tag_name || '%';

Upload files with FTP using PowerShell

You can simply handle file uploads through PowerShell, like this. Complete project is available on Github here https://github.com/edouardkombo/PowerShellFtp

#Directory where to find pictures to upload
$Dir= 'c:\fff\medias\'

#Directory where to save uploaded pictures
$saveDir = 'c:\fff\save\'

#ftp server params
$ftp = 'ftp://10.0.1.11:21/'
$user = 'user'
$pass = 'pass'

#Connect to ftp webclient
$webclient = New-Object System.Net.WebClient 
$webclient.Credentials = New-Object System.Net.NetworkCredential($user,$pass)  

#Initialize var for infinite loop
$i=0

#Infinite loop
while($i -eq 0){ 

    #Pause 1 seconde before continue
    Start-Sleep -sec 1

    #Search for pictures in directory
    foreach($item in (dir $Dir "*.jpg"))
    {
        #Set default network status to 1
        $onNetwork = "1"

        #Get picture creation dateTime...
        $pictureDateTime = (Get-ChildItem $item.fullName).CreationTime

        #Convert dateTime to timeStamp
        $pictureTimeStamp = (Get-Date $pictureDateTime).ToFileTime()

        #Get actual timeStamp
        $timeStamp = (Get-Date).ToFileTime() 

        #Get picture lifeTime
        $pictureLifeTime = $timeStamp - $pictureTimeStamp

        #We only treat pictures that are fully written on the disk
        #So, we put a 2 second delay to ensure even big pictures have been fully wirtten   in the disk
        if($pictureLifeTime -gt "2") {    

            #If upload fails, we set network status at 0
            try{

                $uri = New-Object System.Uri($ftp+$item.Name)

                $webclient.UploadFile($uri, $item.FullName)

            } catch [Exception] {

                $onNetwork = "0"
                write-host $_.Exception.Message;
            }

            #If upload succeeded, we do further actions
            if($onNetwork -eq "1"){
                "Copying $item..."
                Copy-Item -path $item.fullName -destination $saveDir$item 

                "Deleting $item..."
                Remove-Item $item.fullName
            }


        }  
    }
}   

How can I merge the columns from two tables into one output?

When your are three tables or more, just add union and left outer join:

select a.col1, b.col2, a.col3, b.col4, a.category_id 
from 
(
    select category_id from a
    union
    select category_id from b
) as c
left outer join a on a.category_id = c.category_id
left outer join b on b.category_id = c.category_id

Adding additional data to select options using jQuery

HTML/JSP Markup:

<form:option 
data-libelle="${compte.libelleCompte}" 
data-raison="${compte.libelleSociale}"   data-rib="${compte.numeroCompte}"                              <c:out value="${compte.libelleCompte} *MAD*"/>
</form:option>

JQUERY CODE: Event: change

var $this = $(this);
var $selectedOption = $this.find('option:selected');
var libelle = $selectedOption.data('libelle');

To have a element libelle.val() or libelle.text()

Adobe Acrobat Pro make all pages the same dimension

You have to use the Print to a New PDF option using the PDF printer. Once in the dialog box, set the page scaling to 100% and set your page size. Once you do that, your new PDF will be uniform in page sizes.

java.net.UnknownHostException: Unable to resolve host "<url>": No address associated with hostname and End of input at character 0 of

Missed to configure tag in manifest file

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

'foo' was not declared in this scope c++

In general, in C++ functions have to be declared before you call them. So sometime before the definition of getSkewNormal(), the compiler needs to see the declaration:

double integrate (double start, double stop, int numSteps, Evaluatable evalObj);

Mostly what people do is put all the declarations (only) in the header file, and put the actual code -- the definitions of the functions and methods -- into a separate source (*.cc or *.cpp) file. This neatly solves the problem of needing all the functions to be declared.

Python: Tuples/dictionaries as keys, select, sort

You want to use two keys independently, so you have two choices:

  1. Store the data redundantly with two dicts as {'banana' : {'blue' : 4, ...}, .... } and {'blue': {'banana':4, ...} ...}. Then, searching and sorting is easy but you have to make sure you modify the dicts together.

  2. Store it just one dict, and then write functions that iterate over them eg.:

    d = {'banana' : {'blue' : 4, 'yellow':6}, 'apple':{'red':1} }
    
    blueFruit = [(fruit,d[fruit]['blue']) if d[fruit].has_key('blue') for fruit in d.keys()]
    

Bi-directional Map in Java?

You can use the Google Collections API for that, recently renamed to Guava, specifically a BiMap

A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as that of its keys. This constraint enables bimaps to support an "inverse view", which is another bimap containing the same entries as this bimap but with reversed keys and values.

How to override application.properties during production in Spring-Boot?

I know you asked how to do this, but the answer is you should not do this.

Instead, have a application.properties, application-default.properties application-dev.properties etc., and switch profiles via args to the JVM: e.g. -Dspring.profiles.active=dev

You can also override some things at test time using @TestPropertySource

Ideally everything should be in source control so that there are no surprises e.g. How do you know what properties are sitting there in your server location, and which ones are missing? What happens if developers introduce new things?

Spring Boot is already giving you enough ways to do this right.

https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-external-config.html

printf() prints whole array

Incase of arrays, the base address (i.e. address of the array) is the address of the 1st element in the array. Also the array name acts as a pointer.

Consider a row of houses (each is an element in the array). To identify the row, you only need the 1st house address.You know each house is followed by the next (sequential).Getting the address of the 1st house, will also give you the address of the row.

Incase of string literals(character arrays defined at declaration), they are automatically appended by \0.

printf prints using the format specifier and the address provided. Since, you use %s it prints from the 1st address (incrementing the pointer using arithmetic) until '\0'

Target Unreachable, identifier resolved to null in JSF 2.2

I want to share my experience with this Exception. My JSF 2.2 application worked fine with WildFly 8.0, but one time, when I started server, i got this "Target Unreacheable" exception. Actually, there was no problem with JSF annotations or tags.

Only thing I had to do was cleaning the project. After this operation, my app is working fine again.

I hope this will help someone!

Android: How to programmatically access the device serial number shown in the AVD manager (API Version 8)

This is the hardware serial number. To access it on

  • Android Q (>= SDK 29) android.Manifest.permission.READ_PRIVILEGED_PHONE_STATE is required. Only system apps can require this permission. If the calling package is the device or profile owner then the READ_PHONE_STATE permission suffices.

  • Android 8 and later (>= SDK 26) use android.os.Build.getSerial() which requires the dangerous permission READ_PHONE_STATE. Using android.os.Build.SERIAL returns android.os.Build.UNKNOWN.

  • Android 7.1 and earlier (<= SDK 25) and earlier android.os.Build.SERIAL does return a valid serial.

It's unique for any device. If you are looking for possibilities on how to get/use a unique device id you should read here.

For a solution involving reflection without requiring a permission see this answer.

How to verify that a specific method was not called using Mockito?

Both the verifyNoMoreInteractions() and verifyZeroInteractions() method internally have the same implementation as:

public static transient void verifyNoMoreInteractions(Object mocks[])
{
    MOCKITO_CORE.verifyNoMoreInteractions(mocks);
}

public static transient void verifyZeroInteractions(Object mocks[])
{
    MOCKITO_CORE.verifyNoMoreInteractions(mocks);
}

so we can use any one of them on mock object or array of mock objects to check that no methods have been called using mock objects.

What's the difference between map() and flatMap() methods in Java 8?

Map:- This method takes one Function as an argument and returns a new stream consisting of the results generated by applying the passed function to all the elements of the stream.

Let's imagine, I have a list of integer values ( 1,2,3,4,5 ) and one function interface whose logic is square of the passed integer. ( e -> e * e ).

List<Integer> intList = Arrays.asList(1, 2, 3, 4, 5);

List<Integer> newList = intList.stream().map( e -> e * e ).collect(Collectors.toList());

System.out.println(newList);

output:-

[1, 4, 9, 16, 25]

As you can see, an output is a new stream whose values are square of values of the input stream.

[1, 2, 3, 4, 5] -> apply e -> e * e -> [ 1*1, 2*2, 3*3, 4*4, 5*5 ] -> [1, 4, 9, 16, 25 ]

http://codedestine.com/java-8-stream-map-method/

FlatMap :- This method takes one Function as an argument, this function accepts one parameter T as an input argument and returns one stream of parameter R as a return value. When this function is applied to each element of this stream, it produces a stream of new values. All the elements of these new streams generated by each element are then copied to a new stream, which will be a return value of this method.

Let's image, I have a list of student objects, where each student can opt for multiple subjects.

List<Student> studentList = new ArrayList<Student>();

  studentList.add(new Student("Robert","5st grade", Arrays.asList(new String[]{"history","math","geography"})));
  studentList.add(new Student("Martin","8st grade", Arrays.asList(new String[]{"economics","biology"})));
  studentList.add(new Student("Robert","9st grade", Arrays.asList(new String[]{"science","math"})));

  Set<Student> courses = studentList.stream().flatMap( e -> e.getCourse().stream()).collect(Collectors.toSet());

  System.out.println(courses);

output:-

[economics, biology, geography, science, history, math]

As you can see, an output is a new stream whose values are a collection of all the elements of the streams return by each element of the input stream.

[ S1 , S2 , S3 ] -> [ {"history","math","geography"}, {"economics","biology"}, {"science","math"} ] -> take unique subjects -> [economics, biology, geography, science, history, math]

http://codedestine.com/java-8-stream-flatmap-method/

What do parentheses surrounding an object/function/class declaration mean?

It is a self-executing anonymous function. The first set of parentheses contain the expressions to be executed, and the second set of parentheses executes those expressions.

It is a useful construct when trying to hide variables from the parent namespace. All the code within the function is contained in the private scope of the function, meaning it can't be accessed at all from outside the function, making it truly private.

See:

http://en.wikipedia.org/wiki/Closure_%28computer_science%29

http://peter.michaux.ca/articles/javascript-namespacing

Set timeout for ajax (jQuery)

You could use the timeout setting in the ajax options like this:

$.ajax({
    url: "test.html",
    timeout: 3000,
    error: function(){
        //do something
    },
    success: function(){
        //do something
    }
});

Read all about the ajax options here: http://api.jquery.com/jQuery.ajax/

Remember that when a timeout occurs, the error handler is triggered and not the success handler :)

How do I fix the indentation of an entire file in Vi?

For XML files, I use this command

:1,$!xmllint --format --recover - 2>/dev/null

You need to have xmllint installed (package libxml2-utils)

(Source : http://ku1ik.com/2011/09/08/formatting-xml-in-vim-with-indent-command.html )

How to JUnit test that two List<E> contain the same elements in the same order?

The equals() method on your List implementation should do elementwise comparison, so

assertEquals(argumentComponents, returnedComponents);

is a lot easier.

How to get a dependency tree for an artifact?

If you'd like to get a graphical, searchable representation of the dependency tree (including all modules from your project, transitive dependencies and eviction information), check out UpdateImpact: https://app.updateimpact.com (free service).

Disclaimer: I'm one of the developers of the site

What's the canonical way to check for type in Python?

You can check for type of a variable using __name__ of a type.

Ex:

>>> a = [1,2,3,4]  
>>> b = 1  
>>> type(a).__name__
'list'
>>> type(a).__name__ == 'list'
True
>>> type(b).__name__ == 'list'
False
>>> type(b).__name__
'int'

How can I pass a parameter to a Java Thread?

Parameter passing via the start() and run() methods:

// Tester
public static void main(String... args) throws Exception {
    ThreadType2 t = new ThreadType2(new RunnableType2(){
        public void run(Object object) {
            System.out.println("Parameter="+object);
        }});
    t.start("the parameter");
}

// New class 1 of 2
public class ThreadType2 {
    final private Thread thread;
    private Object objectIn = null;
    ThreadType2(final RunnableType2 runnableType2) {
        thread = new Thread(new Runnable() {
            public void run() {
                runnableType2.run(objectIn);
            }});
    }
    public void start(final Object object) {
        this.objectIn = object;
        thread.start();
    }
    // If you want to do things like setDaemon(true); 
    public Thread getThread() {
        return thread;
    }
}

// New class 2 of 2
public interface RunnableType2 {
    public void run(Object object);
}

What are the differences between using the terminal on a mac vs linux?

If you did a new or clean install of OS X version 10.3 or more recent, the default user terminal shell is bash.

Bash is essentially an enhanced and GNU freeware version of the original Bourne shell, sh. If you have previous experience with bash (often the default on GNU/Linux installations), this makes the OS X command-line experience familiar, otherwise consider switching your shell either to tcsh or to zsh, as some find these more user-friendly.

If you upgraded from or use OS X version 10.2.x, 10.1.x or 10.0.x, the default user shell is tcsh, an enhanced version of csh('c-shell'). Early implementations were a bit buggy and the programming syntax a bit weird so it developed a bad rap.

There are still some fundamental differences between mac and linux as Gordon Davisson so aptly lists, for example no useradd on Mac and ifconfig works differently.

The following table is useful for knowing the various unix shells.

sh      The original Bourne shell   Present on every unix system 
ksh     Original Korn shell         Richer shell programming environment than sh 
csh     Original C-shell            C-like syntax; early versions buggy 
tcsh    Enhanced C-shell            User-friendly and less buggy csh implementation 
bash    GNU Bourne-again shell      Enhanced and free sh implementation 
zsh     Z shell                     Enhanced, user-friendly ksh-like shell

You may also find these guides helpful:

http://homepage.mac.com/rgriff/files/TerminalBasics.pdf

http://guides.macrumors.com/Terminal
http://www.ofb.biz/safari/article/476.html

On a final note, I am on Linux (Ubuntu 11) and Mac osX so I use bash and the thing I like the most is customizing the .bashrc (source'd from .bash_profile on OSX) file with aliases, some examples below. I now placed all my aliases in a separate .bash_aliases file and include it with:

if [ -f ~/.bash_aliases ]; then
    . ~/.bash_aliases
fi

in the .bashrc or .bash_profile file.

Note that this is an example of a mac-linux difference because on a Mac you can't have the --color=auto. The first time I did this (without knowing) I redefined ls to be invalid which was a bit alarming until I removed --auto-color !

You may also find https://unix.stackexchange.com/q/127799/10043 useful

# ~/.bash_aliases
# ls variants
#alias l='ls -CF' 
alias la='ls -A' 
alias l='ls -alFtr' 
alias lsd='ls -d .*' 
# Various
alias h='history | tail'
alias hg='history | grep'
alias mv='mv -i' 
alias zap='rm -i'
# One letter quickies:
alias p='pwd'
alias x='exit'
alias {ack,ak}='ack-grep'
# Directories
alias s='cd ..'
alias play='cd ~/play/'
# Rails
alias src='script/rails console'
alias srs='script/rails server'
alias raked='rake db:drop db:create db:migrate db:seed' 
alias rvm-restart='source '\''/home/durrantm/.rvm/scripts/rvm'\'''
alias rrg='rake routes | grep '
alias rspecd='rspec --drb '
#
# DropBox - syncd
WORKBASE="~/Dropbox/97_2012/work"
alias work="cd $WORKBASE"
alias code="cd $WORKBASE/ror/code"
#
# DropNot - NOT syncd !
WORKBASE_GIT="~/Dropnot"
alias {dropnot,not}="cd $WORKBASE_GIT"
alias {webs,ww}="cd $WORKBASE_GIT/webs"
alias {setups,docs}="cd $WORKBASE_GIT/setups_and_docs"
alias {linker,lnk}="cd $WORKBASE_GIT/webs/rails_v3/linker"
#
# git
alias {gsta,gst}='git status' 
# Warning: gst conflicts with gnu-smalltalk (when used).
alias {gbra,gb}='git branch'
alias {gco,go}='git checkout'
alias {gcob,gob}='git checkout -b '
alias {gadd,ga}='git add '
alias {gcom,gc}='git commit'
alias {gpul,gl}='git pull '
alias {gpus,gh}='git push '
alias glom='git pull origin master'
alias ghom='git push origin master'
alias gg='git grep '
#
# vim
alias v='vim'
#
# tmux
alias {ton,tn}='tmux set -g mode-mouse on'
alias {tof,tf}='tmux set -g mode-mouse off'
#
# dmc
alias {dmc,dm}='cd ~/Dropnot/webs/rails_v3/dmc/'
alias wf='cd ~/Dropnot/webs/rails_v3/dmc/dmWorkflow'
alias ws='cd ~/Dropnot/webs/rails_v3/dmc/dmStaffing'

SQL - ORDER BY 'datetime' DESC

  1. use single quotes for strings
  2. do NOT put single quotes around table names(use ` instead)
  3. do NOT put single quotes around numbers (you can, but it's harder to read)
  4. do NOT put AND between ORDER BY and LIMIT
  5. do NOT put = between ORDER BY, LIMIT keywords and condition

So you query will look like:

SELECT post_datetime 
FROM post 
WHERE type = 'published' 
ORDER BY post_datetime DESC 
LIMIT 3

Eclipse: Java was started but returned error code=13

This error occurs because your Eclipse version is 64-bit. You should download and install 64-bit JRE and add the path to it in eclipse.ini. For example:

...
--launcher.appendVmargs
-vm
C:\Program Files\Java\jre1.8.0_45\bin\javaw.exe
-vmargs
...

Note: The -vm parameter should be just before -vmargs and the path should be on a separate line. It should be the full path to the javaw.exe file. Do not enclose the path in double quotes (").

If your Eclipse is 32-bit, install a 32-bit JRE and use the path to its javaw.exe file.

Complex CSS selector for parent of active child

Unfortunately, there's no way to do that with CSS.

It's not very difficult with JavaScript though:

// JavaScript code:
document.getElementsByClassName("active")[0].parentNode;

// jQuery code:
$('.active').parent().get(0); // This would be the <a>'s parent <li>.

how to use getSharedPreferences in android

First get the instance of SharedPreferences using

SharedPreferences userDetails = context.getSharedPreferences("userdetails", MODE_PRIVATE);

Now to save the values in the SharedPreferences

Editor edit = userDetails.edit();
edit.putString("username", username.getText().toString().trim());
edit.putString("password", password.getText().toString().trim());
edit.apply();

Above lines will write username and password to preference

Now to to retrieve saved values from preference, you can follow below lines of code

String userName = userDetails.getString("username", "");
String password = userDetails.getString("password", "");

(NOTE: SAVING PASSWORD IN THE APP IS NOT RECOMMENDED. YOU SHOULD EITHER ENCRYPT THE PASSWORD BEFORE SAVING OR SKIP THE SAVING THE PASSWORD)

Programmatically set the initial view controller using Storyboards

How to without a dummy initial view controller

Ensure all initial view controllers have a Storyboard ID.

In the storyboard, uncheck the "Is initial View Controller" attribute from the first view controller.

If you run your app at this point you'll read:

Failed to instantiate the default view controller for UIMainStoryboardFile 'MainStoryboard' - perhaps the designated entry point is not set?

And you'll notice that your window property in the app delegate is now nil.

In the app's setting, go to your target and the Info tab. There clear the value of Main storyboard file base name. On the General tab, clear the value for Main Interface. This will remove the warning.

Create the window and desired initial view controller in the app delegate's application:didFinishLaunchingWithOptions: method:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];

    UIViewController *viewController = // determine the initial view controller here and instantiate it with [storyboard instantiateViewControllerWithIdentifier:<storyboard id>];

    self.window.rootViewController = viewController;
    [self.window makeKeyAndVisible];

    return YES;
}

Python Pandas : pivot table with aggfunc = count unique distinct

aggfunc=pd.Series.nunique provides distinct count.

Full Code:

df2.pivot_table(values='X', rows='Y', cols='Z', 
                         aggfunc=pd.Series.nunique)

Credit to @hume for this solution (see comment under the accepted answer). Adding as an answer here for better discoverability.

rejected master -> master (non-fast-forward)

You need to do

git branch

if the output is something like:

* (no branch)
master

then do

git checkout master

Make sure you do not have any pending commits as checking out will lose all non-committed changes.

[INSTALL_FAILED_NO_MATCHING_ABIS: Failed to extract native libraries, res=-113]

After some time i investigate and understand that path were located my libs is right. I just need to add folders for different architectures:

  • ARM EABI v7a System Image

  • Intel x86 Atom System Image

  • MIPS System Image

  • Google APIs

Deserialize JSON string to c# object

Same problem happened to me. So if the service returns the response as a JSON string you have to deserialize the string first, then you will be able to deserialize the object type from it properly:

string json= string.Empty;
using (var streamReader = new StreamReader(response.GetResponseStream(), true))
        {
            json= new JavaScriptSerializer().Deserialize<string>(streamReader.ReadToEnd());

        }
//To deserialize to your object type...
MyType myType;
using (var memoryStream = new MemoryStream())
         {
            byte[] jsonBytes = Encoding.UTF8.GetBytes(@json);
            memoryStream.Write(jsonBytes, 0, jsonBytes.Length);
            memoryStream.Seek(0, SeekOrigin.Begin);
            using (var jsonReader = JsonReaderWriterFactory.CreateJsonReader(memoryStream, Encoding.UTF8,          XmlDictionaryReaderQuotas.Max, null))
            {
                var serializer = new DataContractJsonSerializer(typeof(MyType));
                myType = (MyType)serializer.ReadObject(jsonReader);

            }
        }

4 Sure it will work.... ;)

Hexadecimal string to byte array in C

    In main()
    {
printf("enter string :\n");
    fgets(buf, 200, stdin);
unsigned char str_len = strlen(buf);
k=0;
unsigned char bytearray[100];
     for(j=0;j<str_len-1;j=j+2)
        { bytearray[k++]=converttohex(&buffer[j]);   
                printf(" %02X",bytearray[k-1]);
        }

    }

    Use this 

    int converttohex(char * val)
        {
        unsigned char temp = toupper(*val);
        unsigned char fin=0;
        if(temp>64)
        temp=10+(temp-65);

        else
        temp=temp-48;

        fin=(temp<<4)&0xf0;

        temp = toupper(*(val+1));

            if(temp>64)
            temp=10+(temp-65);

            else
            temp=temp-48;

        fin=fin|(temp & 0x0f);


           return fin;
        }

Search for one value in any column of any table inside a database

How to search all columns of all tables in a database for a keyword?

http://vyaskn.tripod.com/search_all_columns_in_all_tables.htm

EDIT: Here's the actual T-SQL, in case of link rot:

CREATE PROC SearchAllTables
(
@SearchStr nvarchar(100)
)
AS
BEGIN

-- Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.
-- Purpose: To search all columns of all tables for a given search string
-- Written by: Narayana Vyas Kondreddi
-- Site: http://vyaskn.tripod.com
-- Tested on: SQL Server 7.0 and SQL Server 2000
-- Date modified: 28th July 2002 22:50 GMT


CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL
BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM    INFORMATION_SCHEMA.TABLES
        WHERE       TABLE_TYPE = 'BASE TABLE'
            AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM    INFORMATION_SCHEMA.COLUMNS
            WHERE       TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND TABLE_NAME  = PARSENAME(@TableName, 1)
                AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar')
                AND QUOTENAME(COLUMN_NAME) > @ColumnName
        )

        IF @ColumnName IS NOT NULL
        BEGIN
            INSERT INTO #Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) 
                FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
            )
        END
    END 
END

SELECT ColumnName, ColumnValue FROM #Results
 END

How can I modify the size of column in a MySQL table?

Have you tried this?

ALTER TABLE <table_name> MODIFY <col_name> VARCHAR(65353);

This will change the col_name's type to VARCHAR(65353)

How to destroy an object?

Short answer: Both are needed.

I feel like the right answer was given but minimally. Yeah generally unset() is best for "speed", but if you want to reclaim memory immediately (at the cost of CPU) should want to use null.

Like others mentioned, setting to null doesn't mean everything is reclaimed, you can have shared memory (uncloned) objects that will prevent destruction of the object. Moreover, like others have said, you can't "destroy" the objects explicitly anyway so you shouldn't try to do it anyway.

You will need to figure out which is best for you. Also you can use __destruct() for an object which will be called on unset or null but it should be used carefully and like others said, never be called directly!

see:

http://www.stoimen.com/blog/2011/11/14/php-dont-call-the-destructor-explicitly/

What is difference between assigning NULL and unset?

What is the best alternative IDE to Visual Studio

Zeus.

Here's an example showing code completion, taken from the Zeus homepage.

example.cs open in Zeus, showing code-completion

Python, Pandas : write content of DataFrame into text File

Way to get Excel data to text file in tab delimited form. Need to use Pandas as well as xlrd.

import pandas as pd
import xlrd
import os

Path="C:\downloads"
wb = pd.ExcelFile(Path+"\\input.xlsx", engine=None)
sheet2 = pd.read_excel(wb, sheet_name="Sheet1")
Excel_Filter=sheet2[sheet2['Name']=='Test']
Excel_Filter.to_excel("C:\downloads\\output.xlsx", index=None)
wb2=xlrd.open_workbook(Path+"\\output.xlsx")
df=wb2.sheet_by_name("Sheet1")
x=df.nrows
y=df.ncols

for i in range(0,x):
    for j in range(0,y):
        A=str(df.cell_value(i,j))
        f=open(Path+"\\emails.txt", "a")
        f.write(A+"\t")
        f.close()
    f=open(Path+"\\emails.txt", "a")
    f.write("\n")
    f.close()
os.remove(Path+"\\output.xlsx")
print(Excel_Filter)

We need to first generate the xlsx file with filtered data and then convert the information into a text file.

Depending on requirements, we can use \n \t for loops and type of data we want in the text file.

How to draw a graph in LaTeX?

In my experience, I always just use an external program to generate the graph (mathematica, gnuplot, matlab, etc.) and export the graph as a pdf or eps file. Then I include it into the document with includegraphics.

How to determine the last Row used in VBA including blank spaces in between

Well apart from all mentioned ones, there are several other ways to find the last row or column in a worksheet or specified range.

Function FindingLastRow(col As String) As Long

  'PURPOSE: Various ways to find the last row in a column or a range
  'ASSUMPTION: col is passed as column header name in string data type i.e. "B", "AZ" etc.

   Dim wks As Worksheet
   Dim lstRow As Long

   Set wks = ThisWorkbook.Worksheets("Sheet1") 'Please change the sheet name
   'Set wks = ActiveSheet   'or for your problem uncomment this line

   'Method #1: By Finding Last used cell in the worksheet
   lstRow = wks.Range("A1").SpecialCells(xlCellTypeLastCell).Row

   'Method #2: Using Table Range
   lstRow = wks.ListObjects("Table1").Range.Rows.Count

   'Method #3 : Manual way of selecting last Row : Ctrl + Shift + End
   lstRow = wks.Cells(wks.Rows.Count, col).End(xlUp).Row

   'Method #4: By using UsedRange
   wks.UsedRange 'Refresh UsedRange
   lstRow = wks.UsedRange.Rows(wks.UsedRange.Rows.Count).Row

   'Method #5: Using Named Range
   lstRow = wks.Range("MyNamedRange").Rows.Count

   'Method #6: Ctrl + Shift + Down (Range should be the first cell in data set)
   lstRow = wks.Range("A1").CurrentRegion.Rows.Count

   'Method #7: Using Range.Find method
   lstRow = wks.Column(col).Cells.Find("*", SearchOrder:=xlByRows, LookIn:=xlValues, SearchDirection:=xlPrevious).Row

   FindingLastRow = lstRow

End Function

Note: Please use only one of the above method as it justifies your problem statement.

Please pay attention to the fact that Find method does not see cell formatting but only data, hence look for xlCellTypeLastCell if only data is important and not formatting. Also, merged cells (which must be avoided) might give you unexpected results as it will give you the row number of the first cell and not the last cell in the merged cells.

SQL Plus change current directory

Have you tried creating a windows shortcut for sql plus and set the working directory?

Where is the visual studio HTML Designer?

Another way of setting the default to the HTML web forms editor is:

  1. At the top menu in Visual Studio go to File > New > File
  2. Select HTML Page
  3. In the lower right corner of the New File dialog on the Open button there is a down arrow
  4. Click it and you should see an option Open With
  5. Select HTML (Web Forms) Editor
  6. Click Set as Default
  7. Press OK

Screenshot showing how to get to the "Open With" dialog box when creating a new file.

How to run regasm.exe from command line other than Visual Studio command prompt?

By dragging and dropping the dll onto 'regasm' you can register it. You can open two 'Window Explorer' windows. One will contain the dll you wish to register. The 2nd window will be the location of the 'regasm' application. Scroll down in both windows so that you have a view of both the dll and 'regasm'. It helps to reduce the size of the two windows so they are side-by-side. Be sure to drag the dll over the 'regasm' that is labeled 'application'. There are several 'regasm' files but you only want the application.

PHP - define constant inside a class

This is and old question, but now on PHP 7.1 you can define constant visibility.

EXAMPLE

<?php
class Foo {
    // As of PHP 7.1.0
    public const BAR = 'bar';
    private const BAZ = 'baz';
}
echo Foo::BAR . PHP_EOL;
echo Foo::BAZ . PHP_EOL;
?>

Output of the above example in PHP 7.1:

bar

Fatal error: Uncaught Error: Cannot access private const Foo::BAZ in …

Note: As of PHP 7.1.0 visibility modifiers are allowed for class constants.

More info here

Installing mcrypt extension for PHP on OSX Mountain Lion

Installing php-mcrypt without the use of port or brew

Note: these instructions are long because they intend to be thorough. The process is actually fairly straight-forward. If you're an optimist, you can skip down to the building the mcrypt extension section, but you may very well see the errors I did, telling me to install autoconf and libmcrypt first.

I have just gone through this on a fresh install of OSX 10.9. The solution which worked for me was very close to that of ckm - I am including their steps as well as my own in full, for completeness. My main goal (other than "having mcrypt") was to perform the installation in a way which left the least impact on the system as a whole. That means doing things manually (no port, no brew)

To do things manually, you will first need a couple of dependencies: one for building PHP modules, and another for mcrypt specifically. These are autoconf and libmcrypt, either of which you might have already, but neither of which you will have on a fresh install of OSX 10.9.

autoconf

Autoconf (for lack of a better description) is used to tell not-quite-disparate, but still very different, systems how to compile things. It allows you to use the same set of basic commands to build modules on Linux as you would on OSX, for example, despite their different file-system hierarchies, etc. I used the method described by Ares on StackOverflow, which I will reproduce here for completeness. This one is very straight-forward:

$ mkdir -p ~/mcrypt/dependencies/autoconf
$ cd ~/mcrypt/dependencies/autoconf
$ curl -OL http://ftpmirror.gnu.org/autoconf/autoconf-latest.tar.gz
$ tar xzf autoconf-latest.tar.gz
$ cd autoconf-*/
$ ./configure --prefix=/usr/local
$ make
$ sudo make install

Next, verify the installation by running:

$ which autoconf

which should return /usr/local/bin/autoconf

libmcrypt

Next, you will need libmcrypt, used to provide the guts of the mcrypt extension (the extension itself being a provision of a PHP interface into this library). The method I used was based on the one described here, but I have attempted to simplify things as best I can:

First, download the libmcrypt source, available from SourceForge, and available as of the time of this writing, specifically, at:

http://sourceforge.net/projects/mcrypt/files/Libmcrypt/2.5.8/libmcrypt-2.5.8.tar.bz2/download

You'll need to jump through the standard SourceForge hoops to get at the real download link, but once you have it, you can pass it in to something like this:

$ mkdir -p ~/mcrypt/dependencies/libmcrypt
$ cd ~/mcrypt/dependencies/libmcrypt
$ curl -L -o libmcrypt.tar.bz2 '<SourceForge direct link URL>'
$ tar xjf libmcrypt.tar.bz2
$ cd libmcrypt-*/
$ ./configure
$ make
$ sudo make install

The only way I know of to verify that this has worked is via the ./configure step for the mcrypt extension itself (below)

building the mcrypt extension

This is our actual goal. Hopefully the brief stint into dependency hell is over now.

First, we're going to need to get the source code for the mcrypt extension. This is most-readily available buried within the source code for all of PHP. So: determine what version of the PHP source code you need.

$ php --version # to get your PHP version

now, if you're lucky, your current version will be available for download from the main mirrors. If it is, you can type something like:

$ mkdir -p ~/mcrypt/php
$ cd ~/mcrypt/php
$ curl -L -o php-5.4.17.tar.bz2 http://www.php.net/get/php-5.4.17.tar.bz2/from/a/mirror

Unfortunately, my current version (5.4.17, in this case) was not available, so I needed to use the alternative/historical links at http://downloads.php.net/stas/ (also an official PHP download site). For these, you can use something like:

$ mkdir -p ~/mcrypt/php
$ cd ~/mcrypt/php
$ curl -LO http://downloads.php.net/stas/php-5.4.17.tar.bz2

Again, based on your current version.

Once you have it, (and all the dependencies, from above), you can get to the main process of actually building/installing the module.

$ cd ~/mcrypt/php
$ tar xjf php-*.tar.bz2
$ cd php-*/ext/mcrypt
$ phpize
$ ./configure # this is the step which fails without the above dependencies
$ make
$ make test
$ sudo make install

In theory, mcrypt.so is now in your PHP extension directory. Next, we need to tell PHP about it.

configuring the mcrypt extension

Your php.ini file needs to be told to load mcrypt. By default in OSX 10.9, it actually has mcrypt-specific configuration information, but it doesn't actually activate mcrypt unless you tell it to.

The php.ini file does not, by default, exist. Instead, the file /private/etc/php.ini.default lists the default configuration, and can be used as a good template for creating the "true" php.ini, if it does not already exist.

To determine whether php.ini already exists, run:

$ ls /private/etc/php.ini

If there is a result, it already exists, and you should skip the next command.

To create the php.ini file, run:

$ sudo cp /private/etc/php.ini.default /private/etc/php.ini

Next, you need to add the line:

extension=mcrypt.so

Somewhere in the file. I would recommend searching the file for ;extension=, and adding it immediately prior to the first occurrence.

Once this is done, the installation and configuration is complete. You can verify that this has worked by running:

php -m | grep mcrypt

Which should output "mcrypt", and nothing else.

If your use of PHP relies on Apache's httpd, you will need to restart it before you will notice the changes on the web. You can do so via:

$ sudo apachectl restart

And you're done.

Could not resolve Spring property placeholder

It's definitely not a problem with propeties file not being found, since in that case another exception is thrown.

Make sure that you actually have a value with key idm.url in your idm.properties.

Retrieving subfolders names in S3 bucket from boto3

Why not use the s3path package which makes it as convenient as working with pathlib? If you must however use boto3:

Using boto3.resource

This builds upon the answer by itz-azhar to apply an optional limit. It is obviously substantially simpler to use than the boto3.client version.

import logging
from typing import List, Optional

import boto3
from boto3_type_annotations.s3 import ObjectSummary  # pip install boto3_type_annotations

log = logging.getLogger(__name__)
_S3_RESOURCE = boto3.resource("s3")

def s3_list(bucket_name: str, prefix: str, *, limit: Optional[int] = None) -> List[ObjectSummary]:
    """Return a list of S3 object summaries."""
    # Ref: https://stackoverflow.com/a/57718002/
    return list(_S3_RESOURCE.Bucket(bucket_name).objects.limit(count=limit).filter(Prefix=prefix))


if __name__ == "__main__":
    s3_list("noaa-gefs-pds", "gefs.20190828/12/pgrb2a", limit=10_000)

Using boto3.client

This uses list_objects_v2 and builds upon the answer by CpILL to allow retrieving more than 1000 objects.

import logging
from typing import cast, List

import boto3

log = logging.getLogger(__name__)
_S3_CLIENT = boto3.client("s3")

def s3_list(bucket_name: str, prefix: str, *, limit: int = cast(int, float("inf"))) -> List[dict]:
    """Return a list of S3 object summaries."""
    # Ref: https://stackoverflow.com/a/57718002/
    contents: List[dict] = []
    continuation_token = None
    if limit <= 0:
        return contents
    while True:
        max_keys = min(1000, limit - len(contents))
        request_kwargs = {"Bucket": bucket_name, "Prefix": prefix, "MaxKeys": max_keys}
        if continuation_token:
            log.info(  # type: ignore
                "Listing %s objects in s3://%s/%s using continuation token ending with %s with %s objects listed thus far.",
                max_keys, bucket_name, prefix, continuation_token[-6:], len(contents))  # pylint: disable=unsubscriptable-object
            response = _S3_CLIENT.list_objects_v2(**request_kwargs, ContinuationToken=continuation_token)
        else:
            log.info("Listing %s objects in s3://%s/%s with %s objects listed thus far.", max_keys, bucket_name, prefix, len(contents))
            response = _S3_CLIENT.list_objects_v2(**request_kwargs)
        assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
        contents.extend(response["Contents"])
        is_truncated = response["IsTruncated"]
        if (not is_truncated) or (len(contents) >= limit):
            break
        continuation_token = response["NextContinuationToken"]
    assert len(contents) <= limit
    log.info("Returning %s objects from s3://%s/%s.", len(contents), bucket_name, prefix)
    return contents


if __name__ == "__main__":
    s3_list("noaa-gefs-pds", "gefs.20190828/12/pgrb2a", limit=10_000)

Storing files in SQL Server

There's still no simple answer. It depends on your scenario. MSDN has documentation to help you decide.

There are other options covered here. Instead of storing in the file system directly or in a BLOB, you can use the FileStream or File Table in SQL Server 2012. The advantages to File Table seem like a no-brainier (but admittedly I have no personal first-hand experience with them.)

The article is definitely worth a read.

How do I fix the error 'Named Pipes Provider, error 40 - Could not open a connection to' SQL Server'?

Use SERVER\\ INSTANCE NAME .Using double backslash in my project solved my problem.

What is the difference between a symbolic link and a hard link?

Soft Link:

soft or symbolic is more of a short cut to the original file....if you delete the original the shortcut fails and if you only delete the short cut nothing happens to the original.

Soft link Syntax: ln -s Pathof_Target_file link

Output : link -> ./Target_file

Proof: readlink link Also in ls -l link output you will see the first letter in lrwxrwxrwx as l which is indication that the file is a soft link.

Deleting the link: unlink link

Note: If you wish, your softlink can work even after moving it somewhere else from the current dir. Make sure you give absolute path and not relative path while creating a soft link. i.e.(starting from /root/user/Target_file and not ./Target_file)

Hard Link:

Hard link is more of a mirror copy or multiple paths to the same file. Do something to file1 and it appears in file 2. Deleting one still keeps the other ok.

The inode(or file) is only deleted when all the (hard)links or all the paths to the (same file)inode has been deleted.

Once a hard link has been made the link has the inode of the original file. Deleting renaming or moving the original file will not affect the hard link as it links to the underlying inode. Any changes to the data on the inode is reflected in all files that refer to that inode.

Hard Link syntax: ln Target_file link

Output: A file with name link will be created with the same inode number as of Targetfile.

Proof: ls -i link Target_file (check their inodes)

Deleting the link: rm -f link (Delete the link just like a normal file)

Note: Symbolic links can span file systems as they are simply the name of another file. Whereas hard links are only valid within the same File System.

Symbolic links have some features hard links are missing:

  • Hard link point to the file content. while Soft link points to the file name.
  • while size of hard link is the size of the content while soft link is having the file name size.
  • Hard links share the same inode. Soft links do not.
  • Hard links can't cross file systems. Soft links do.
  • you know immediately where a symbolic link points to while with hard links, you need to explore the whole file system to find files sharing the same inode.

    # find / -inum 517333

    /home/bobbin/sync.sh
    /root/synchro
    
  • hard-links cannot point to directories.

The hard links have two limitations:

  • The directories cannot be hard linked. Linux does not permit this to maintain the acyclic tree structure of directories.
  • A hard link cannot be created across filesystems. Both the files must be on the same filesystems, because different filesystems have different independent inode tables (two files on different filesystems, but with same inode number will be different).

Imported a csv-dataset to R but the values becomes factors

for me the solution was to include skip = 0 (number of rows to skip at the top of the file. Can be set >0)

mydata <- read.csv(file = "file.csv", header = TRUE, sep = ",", skip = 22)

Difference between Relative path and absolute path in javascript

Imagine you have a window open on http://www.foo.com/bar/page.html In all of them (HTML, Javascript and CSS):

opened_url = http://www.foo.com/bar/page.html
base_path = http://www.foo.com/bar/
home_path = http://www.foo.com/
/kitten.png = Home_path/kitten.png
kitten.png = Base_path/kitten.png

In HTML and Javascript, the base_path is based on the opened window. In big javascript projects you need a BASEPATH or root variable to store the base_path occasionally. (like this)

In CSS the opened url is the address of which your .css is stored or loaded, its not the same like javascript with current opened window in this case.

And for being more secure in absolute paths it is recommended to use // instead of http:// for possible future migrations to https://. In your own example, use it this way:

<img src="//www.foo.com/images/kitten.png">

How to increment a number by 2 in a PHP For Loop

<?php    
     $x = 1;

     for($x = 1; $x < 8; $x++) {
       $x = $x + 2;
       echo $x;
     };
?>

How to view changes made to files on a certain revision in Subversion

The equivalent command in svn is:

svn log --diff -r revision

Evaluate a string with a switch in C++

You can't. Full stop.

switch is only for integral types, if you want to branch depending on a string you need to use if/else.

how to convert binary string to decimal?

Use the radix parameter of parseInt:

var binary = "1101000";
var digit = parseInt(binary, 2);
console.log(digit);

Install windows service without InstallUtil.exe

You can still use installutil without visual studio, it is included with the .net framework

On your server, open a command prompt as administrator then:

CD C:\Windows\Microsoft.NET\Framework\v4.0.version (insert your version)

installutil "C:\Program Files\YourWindowsService\YourWindowsService.exe" (insert your service name/location)

To uninstall:

installutil /u "C:\Program Files\YourWindowsService\YourWindowsService.exe" (insert your service name/location)

How to reference a local XML Schema file correctly?

Add one more slash after file:// in the value of xsi:schemaLocation. (You have two; you need three. Think protocol://host/path where protocol is 'file' and host is empty here, yielding three slashes in a row.) You can also eliminate the double slashes along the path. I believe that the double slashes help with file systems that allow spaces in file and directory names, but you wisely avoided that complication in your path naming.

xsi:schemaLocation="http://www.w3schools.com file:///C:/environment/workspace/maven-ws/ProjextXmlSchema/email.xsd"

Still not working? I suggest that you carefully copy the full file specification for the XSD into the address bar of Chrome or Firefox:

file:///C:/environment/workspace/maven-ws/ProjextXmlSchema/email.xsd

If the XSD does not display in the browser, delete all but the last component of the path (email.xsd) and see if you can't display the parent directory. Continue in this manner, walking up the directory structure until you discover where the path diverges from the reality of your local filesystem.

If the XSD does displayed in the browser, state what XML processor you're using, and be prepared to hear that it's broken or that you must work around some limitation. I can tell you that the above fix will work with my Xerces-J-based validator.

How to get column values in one comma separated value

You can do this with the following SQL:

SELECT STUFF
(
    (
        SELECT ',' + s.FirstName 
        FROM Employee s
        ORDER BY s.FirstName FOR XML PATH('')
    ),
     1, 1, ''
) AS Employees

Static nested class in Java, why?

Adavantage of inner class--

  1. one time use
  2. supports and improves encapsulation
  3. readibility
  4. private field access

Without existing of outer class inner class will not exist.

class car{
    class wheel{

    }
}

There are four types of inner class.

  1. normal inner class
  2. Method Local Inner class
  3. Anonymous inner class
  4. static inner class

point ---

  1. from static inner class ,we can only access static member of outer class.
  2. Inside inner class we cananot declare static member .
  3. inorder to invoke normal inner class in static area of outer class.

    Outer 0=new Outer(); Outer.Inner i= O.new Inner();

  4. inorder to invoke normal inner class in instance area of outer class.

    Inner i=new Inner();

  5. inorder to invoke normal inner class in outside of outer class.

    Outer 0=new Outer(); Outer.Inner i= O.new Inner();

  6. inside Inner class This pointer to inner class.

    this.member-current inner class outerclassname.this--outer class

  7. for inner class applicable modifier is -- public,default,

    final,abstract,strictfp,+private,protected,static

  8. outer$inner is the name of inner class name.

  9. inner class inside instance method then we can acess static and instance field of outer class.

10.inner class inside static method then we can access only static field of

outer class.

class outer{

    int x=10;
    static int y-20;

    public void m1() {
        int i=30;
        final j=40;

        class inner{

            public void m2() {
                // have accees x,y and j
            }
        }
    }
}

How to add button in ActionBar(Android)?

An activity populates the ActionBar in its onCreateOptionsMenu() method.

Instead of using setcustomview(), just override onCreateOptionsMenu like this:

@Override    
public boolean onCreateOptionsMenu(Menu menu) {
  MenuInflater inflater = getMenuInflater();
  inflater.inflate(R.menu.mainmenu, menu);
  return true;
}

If an actions in the ActionBar is selected, the onOptionsItemSelected() method is called. It receives the selected action as parameter. Based on this information you code can decide what to do for example:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
  switch (item.getItemId()) {
    case R.id.menuitem1:
      Toast.makeText(this, "Menu Item 1 selected", Toast.LENGTH_SHORT).show();
      break;
    case R.id.menuitem2:
      Toast.makeText(this, "Menu item 2 selected", Toast.LENGTH_SHORT).show();
      break;
  }
  return true;
}

Open files always in a new tab

enabling using GUI

go to Code -> Preferences -> Settings -> User -> Window -> New Window

here Open Files In New Window under drop down list select "on" that's it.

my VS Code version 1.38.1

org.hibernate.MappingException: Could not determine type for: java.util.List, at table: College, for columns: [org.hibernate.mapping.Column(students)]

Problem with Access strategies

As a JPA provider, Hibernate can introspect both the entity attributes (instance fields) or the accessors (instance properties). By default, the placement of the @Id annotation gives the default access strategy. When placed on a field, Hibernate will assume field-based access. Placed on the identifier getter, Hibernate will use property-based access.

Field-based access

When using field-based access, adding other entity-level methods is much more flexible because Hibernate won’t consider those part of the persistence state

@Entity
public class Simple {

@Id
private Integer id;

@OneToMany(targetEntity=Student.class, mappedBy="college", 
fetch=FetchType.EAGER)
private List<Student> students;

//getter +setter
}

Property-based access

When using property-based access, Hibernate uses the accessors for both reading and writing the entity state

@Entity
public class Simple {

private Integer id;
private List<Student> students;

@Id
public Integer getId() {
    return id;
}

public void setId( Integer id ) {
    this.id = id;
}
@OneToMany(targetEntity=Student.class, mappedBy="college", 
fetch=FetchType.EAGER)
public List<Student> getStudents() {
   return students;
}
public void setStudents(List<Student> students) {
    this.students = students;
}

}

But you can't use both Field-based and Property-based access at the same time. It will show like that error for you

For more idea follow this

HTML+CSS: How to force div contents to stay in one line?

Give this a try. It uses pre rather than nowrap as I would assume you would want this to run similarly to <pre> but either will work just fine:

div {
    border: 1px solid black;
    max-width: 70px;
    white-space:pre;
}

http://jsfiddle.net/NXchy/11/

linq where list contains any in list

I guess this is also possible like this?

var movies = _db.Movies.TakeWhile(p => p.Genres.Any(x => listOfGenres.Contains(x));

Is "TakeWhile" worse than "Where" in sense of performance or clarity?

PHP reindex array?

Use array_values.

$myarray = array_values($myarray);

POST request with JSON body

I think cURL would be a good solution. This is not tested, but you can try something like this:

$body = '{
  "kind": "blogger#post",
  "blog": {
    "id": "8070105920543249955"
  },
  "title": "A new post",
  "content": "With <b>exciting</b> content..."
}';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://www.googleapis.com/blogger/v3/blogs/8070105920543249955/posts/");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/json","Authorization: OAuth 2.0 token here"));
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $body);
$result = curl_exec($ch);

psql: could not connect to server: No such file or directory (Mac OS X)

Maybe this is unrelated but a similar error appears when you upgrade postgres to a major version using brew; using brew info postgresql found out this that helped:

To migrate existing data from a previous major version of PostgreSQL run:
brew postgresql-upgrade-database

Scheduled run of stored procedure on SQL server

If MS SQL Server Express Edition is being used then SQL Server Agent is not available. I found the following worked for all editions:

USE Master
GO

IF  EXISTS( SELECT *
            FROM sys.objects
            WHERE object_id = OBJECT_ID(N'[dbo].[MyBackgroundTask]')
            AND type in (N'P', N'PC'))
    DROP PROCEDURE [dbo].[MyBackgroundTask]
GO

CREATE PROCEDURE MyBackgroundTask
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- The interval between cleanup attempts
    declare @timeToRun nvarchar(50)
    set @timeToRun = '03:33:33'

    while 1 = 1
    begin
        waitfor time @timeToRun
        begin
            execute [MyDatabaseName].[dbo].[MyDatabaseStoredProcedure];
        end
    end
END
GO

-- Run the procedure when the master database starts.
sp_procoption    @ProcName = 'MyBackgroundTask',
                @OptionName = 'startup',
                @OptionValue = 'on'
GO

Some notes:

Generate UML Class Diagram from Java Project

I wrote Class Visualizer, which does it. It's free tool which has all the mentioned functionality - I personally use it for the same purposes, as described in this post. For each browsed class it shows 2 instantly generated class diagrams: class relations and class UML view. Class relations diagram allows to traverse through the whole structure. It has full support for annotations and generics plus special support for JPA entities. Works very well with big projects (thousands of classes).

Dump a list in a pickle file and retrieve it back later

Pickling will serialize your list (convert it, and it's entries to a unique byte string), so you can save it to disk. You can also use pickle to retrieve your original list, loading from the saved file.

So, first build a list, then use pickle.dump to send it to a file...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>> 
>>> import pickle
>>> 
>>> with open('parrot.pkl', 'wb') as f:
...   pickle.dump(mylist, f)
... 
>>> 

Then quit and come back later… and open with pickle.load...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
...   mynewlist = pickle.load(f)
... 
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>

Should we @Override an interface's method implementation?

If a concrete class is not overriding an abstract method, using @Override for implementation is an open matter since the compiler will invariably warn you of any unimplemented methods. In these cases, an argument can be made that it detracts from readability -- it is more things to read on your code and, to a lesser degree, it is called @Override and not @Implement.

PHP - Modify current object in foreach loop

Surely using array_map and if using a container implementing ArrayAccess to derive objects is just a smarter, semantic way to go about this?

Array map semantics are similar across most languages and implementations that I've seen. It's designed to return a modified array based upon input array element (high level ignoring language compile/runtime type preference); a loop is meant to perform more logic.

For retrieving objects by ID / PK, depending upon if you are using SQL or not (it seems suggested), I'd use a filter to ensure I get an array of valid PK's, then implode with comma and place into an SQL IN() clause to return the result-set. It makes one call instead of several via SQL, optimising a bit of the call->wait cycle. Most importantly my code would read well to someone from any language with a degree of competence and we don't run into mutability problems.

<?php

$arr = [0,1,2,3,4];
$arr2 = array_map(function($value) { return is_int($value) ? $value*2 : $value; }, $arr);
var_dump($arr);
var_dump($arr2);

vs

<?php

$arr = [0,1,2,3,4];
foreach($arr as $i => $item) {
    $arr[$i] = is_int($item) ? $item * 2 : $item;
}
var_dump($arr);

If you know what you are doing will never have mutability problems (bearing in mind if you intend upon overwriting $arr you could always $arr = array_map and be explicit.

Round a divided number in Bash

bash will not give you correct result of 3/2 since it doesn't do floating pt maths. you can use tools like awk

$ awk  'BEGIN { rounded = sprintf("%.0f", 3/2); print rounded }'
2

or bc

$ printf "%.0f" $(echo "scale=2;3/2" | bc)
2

allowing only alphabets in text box using java script

just use onkeypress event like below:

<input type="text" name="onlyalphabet" onkeypress="return (event.charCode > 64 && event.charCode < 91) || (event.charCode > 96 && event.charCode < 123)">

selenium - chromedriver executable needs to be in PATH

An answer from 2020. The following code solves this. A lot of people new to selenium seem to have to get past this step. Install the chromedriver and put it inside a folder on your desktop. Also make sure to put the selenium python project in the same folder as where the chrome driver is located.

Change USER_NAME and FOLDER in accordance to your computer.

For Windows

driver = webdriver.Chrome(r"C:\Users\USER_NAME\Desktop\FOLDER\chromedriver")

For Linux/Mac

driver = webdriver.Chrome("/home/USER_NAME/FOLDER/chromedriver")

Coloring Buttons in Android with Material Design and AppCompat

To change the color of a single button

ViewCompat.setBackgroundTintList(button, getResources().getColorStateList(R.color.colorId));

Is an entity body allowed for an HTTP DELETE request?

One reason to use the body in a delete request is for optimistic concurrency control.

You read version 1 of a record.

GET /some-resource/1
200 OK { id:1, status:"unimportant", version:1 }

Your colleague reads version 1 of the record.

GET /some-resource/1
200 OK { id:1, status:"unimportant", version:1 }

Your colleague changes the record and updates the database, which updates the version to 2:

PUT /some-resource/1 { id:1, status:"important", version:1 }
200 OK { id:1, status:"important", version:2 }

You try to delete the record:

DELETE /some-resource/1 { id:1, version:1 }
409 Conflict

You should get an optimistic lock exception. Re-read the record, see that it's important, and maybe not delete it.

Another reason to use it is to delete multiple records at a time (for example, a grid with row-selection check-boxes).

DELETE /messages
[{id:1, version:2},
{id:99, version:3}]
204 No Content

Notice that each message has its own version. Maybe you can specify multiple versions using multiple headers, but by George, this is simpler and much more convenient.

This works in Tomcat (7.0.52) and Spring MVC (4.05), possibly w earlier versions too:

@RestController
public class TestController {

    @RequestMapping(value="/echo-delete", method = RequestMethod.DELETE)
    SomeBean echoDelete(@RequestBody SomeBean someBean) {
        return someBean;
    }
}

Compile to stand alone exe for C# app in Visual Studio 2010

I am using visual studio 2010 to make a program on SMSC Server. What you have to do is go to build-->publish. you will be asked be asked to few simple things and the location where you want to store your application, browse the location where you want to put it.

I hope this is what you are looking for

How to use ConcurrentLinkedQueue?

This is largely a duplicate of another question.

Here's the section of that answer that is relevant to this question:

Do I need to do my own synchronization if I use java.util.ConcurrentLinkedQueue?

Atomic operations on the concurrent collections are synchronized for you. In other words, each individual call to the queue is guaranteed thread-safe without any action on your part. What is not guaranteed thread-safe are any operations you perform on the collection that are non-atomic.

For example, this is threadsafe without any action on your part:

queue.add(obj);

or

queue.poll(obj);

However; non-atomic calls to the queue are not automatically thread-safe. For example, the following operations are not automatically threadsafe:

if(!queue.isEmpty()) {
   queue.poll(obj);
}

That last one is not threadsafe, as it is very possible that between the time isEmpty is called and the time poll is called, other threads will have added or removed items from the queue. The threadsafe way to perform this is like this:

synchronized(queue) {
    if(!queue.isEmpty()) {
       queue.poll(obj);
    }
}

Again...atomic calls to the queue are automatically thread-safe. Non-atomic calls are not.

Bootstrap 3 Align Text To Bottom of Div

I think your best bet would be to use a combination of absolute and relative positioning.

Here's a fiddle: http://jsfiddle.net/PKVza/2/

given your html:

<div class="row">
    <div class="col-sm-6">
        <img src="~/Images/MyLogo.png" alt="Logo" />
    </div>
    <div class="bottom-align-text col-sm-6">
        <h3>Some Text</h3>
    </div>
</div>

use the following CSS:

@media (min-width: 768px ) {
  .row {
      position: relative;
  }

  .bottom-align-text {
    position: absolute;
    bottom: 0;
    right: 0;
  }
}

EDIT - Fixed CSS and JSFiddle for mobile responsiveness and changed the ID to a class.

Rails Model find where not equal

In Rails 4.x (See http://edgeguides.rubyonrails.org/active_record_querying.html#not-conditions)

GroupUser.where.not(user_id: me)

In Rails 3.x

GroupUser.where(GroupUser.arel_table[:user_id].not_eq(me))

To shorten the length, you could store GroupUser.arel_table in a variable or if using inside the model GroupUser itself e.g., in a scope, you can use arel_table[:user_id] instead of GroupUser.arel_table[:user_id]

Rails 4.0 syntax credit to @jbearden's answer

What does `set -x` do?

set -x

Prints a trace of simple commands, for commands, case commands, select commands, and arithmetic for commands and their arguments or associated word lists after they are expanded and before they are executed. The value of the PS4 variable is expanded and the resultant value is printed before the command and its expanded arguments.

[source]

Example

set -x
echo `expr 10 + 20 `
+ expr 10 + 20
+ echo 30
30

set +x
echo `expr 10 + 20 `
30

Above example illustrates the usage of set -x. When it is used, above arithmetic expression has been expanded. We could see how a singe line has been evaluated step by step.

  • First step expr has been evaluated.
  • Second step echo has been evaluated.

To know more about set ? visit this link

when it comes to your shell script,

[ "$DEBUG" == 'true' ] && set -x

Your script might have been printing some additional lines of information when the execution mode selected as DEBUG. Traditionally people used to enable debug mode when a script called with optional argument such as -d

How to do a redirect to another route with react-router?

The simplest solution is:

import { Redirect } from 'react-router';

<Redirect to='/componentURL' />

Importing Excel spreadsheet data into another Excel spreadsheet containing VBA

Data can be pulled into an excel from another excel through Workbook method or External reference or through Data Import facility.

If you want to read or even if you want to update another excel workbook, these methods can be used. We may not depend only on VBA for this.

For more info on these techniques, please click here to refer the article

Django Rest Framework File Upload

I'd like to write another option that I feel is cleaner and easier to maintain. We'll be using the defaultRouter to add CRUD urls for our viewset and we'll add one more fixed url specifying the uploader view within the same viewset.

**** views.py 

from rest_framework import viewsets, serializers
from rest_framework.decorators import action, parser_classes
from rest_framework.parsers import JSONParser, MultiPartParser
from rest_framework.response import Response
from rest_framework_csv.parsers import CSVParser
from posts.models import Post
from posts.serializers import PostSerializer     


class PostsViewSet(viewsets.ModelViewSet):

    queryset = Post.objects.all()
    serializer_class = PostSerializer 
    parser_classes = (JSONParser, MultiPartParser, CSVParser)


    @action(detail=False, methods=['put'], name='Uploader View', parser_classes=[CSVParser],)
    def uploader(self, request, filename, format=None):
        # Parsed data will be returned within the request object by accessing 'data' attr  
        _data = request.data

        return Response(status=204)

Project's main urls.py

**** urls.py 

from rest_framework import routers
from posts.views import PostsViewSet


router = routers.DefaultRouter()
router.register(r'posts', PostsViewSet)

urlpatterns = [
    url(r'^posts/uploader/(?P<filename>[^/]+)$', PostsViewSet.as_view({'put': 'uploader'}), name='posts_uploader')
    url(r'^', include(router.urls), name='root-api'),
    url('admin/', admin.site.urls),
]

.- README.

The magic happens when we add @action decorator to our class method 'uploader'. By specifying "methods=['put']" argument, we are only allowing PUT requests; perfect for file uploading.

I also added the argument "parser_classes" to show you can select the parser that will parse your content. I added CSVParser from the rest_framework_csv package, to demonstrate how we can accept only certain type of files if this functionality is required, in my case I'm only accepting "Content-Type: text/csv". Note: If you're adding custom Parsers, you'll need to specify them in parsers_classes in the ViewSet due the request will compare the allowed media_type with main (class) parsers before accessing the uploader method parsers.

Now we need to tell Django how to go to this method and where can be implemented in our urls. That's when we add the fixed url (Simple purposes). This Url will take a "filename" argument that will be passed in the method later on. We need to pass this method "uploader", specifying the http protocol ('PUT') in a list to the PostsViewSet.as_view method.

When we land in the following url

 http://example.com/posts/uploader/ 

it will expect a PUT request with headers specifying "Content-Type" and Content-Disposition: attachment; filename="something.csv".

curl -v -u user:pass http://example.com/posts/uploader/ --upload-file ./something.csv --header "Content-type:text/csv"

Angular2 set value for formGroup

To set all FormGroup values use, setValue:

this.myFormGroup.setValue({
  formControlName1: myValue1, 
  formControlName2: myValue2
});

To set only some values, use patchValue:

this.myFormGroup.patchValue({
  formControlName1: myValue1, 
  // formControlName2: myValue2 (can be omitted)
});

With this second technique, not all values need to be supplied and fields whos values were not set will not be affected.

Execute a command in command prompt using excel VBA

The S parameter does not do anything on its own.

/S      Modifies the treatment of string after /C or /K (see below) 
/C      Carries out the command specified by string and then terminates  
/K      Carries out the command specified by string but remains  

Try something like this instead

Call Shell("cmd.exe /S /K" & "perl a.pl c:\temp", vbNormalFocus)

You may not even need to add "cmd.exe" to this command unless you want a command window to open up when this is run. Shell should execute the command on its own.

Shell("perl a.pl c:\temp")



-Edit-
To wait for the command to finish you will have to do something like @Nate Hekman shows in his answer here

Dim wsh As Object
Set wsh = VBA.CreateObject("WScript.Shell")
Dim waitOnReturn As Boolean: waitOnReturn = True
Dim windowStyle As Integer: windowStyle = 1

wsh.Run "cmd.exe /S /C perl a.pl c:\temp", windowStyle, waitOnReturn

How do I apply a CSS class to Html.ActionLink in ASP.NET MVC?

This works for MVC 5

@Html.ActionLink("LinkText", "ActionName", new { id = item.id }, new { @class = "btn btn-success" })

Why is ZoneOffset.UTC != ZoneId.of("UTC")?

The answer comes from the javadoc of ZoneId (emphasis mine) ...

A ZoneId is used to identify the rules used to convert between an Instant and a LocalDateTime. There are two distinct types of ID:

  • Fixed offsets - a fully resolved offset from UTC/Greenwich, that uses the same offset for all local date-times
  • Geographical regions - an area where a specific set of rules for finding the offset from UTC/Greenwich apply

Most fixed offsets are represented by ZoneOffset. Calling normalized() on any ZoneId will ensure that a fixed offset ID will be represented as a ZoneOffset.

... and from the javadoc of ZoneId#of (emphasis mine):

This method parses the ID producing a ZoneId or ZoneOffset. A ZoneOffset is returned if the ID is 'Z', or starts with '+' or '-'.

The argument id is specified as "UTC", therefore it will return a ZoneId with an offset, which also presented in the string form:

System.out.println(now.withZoneSameInstant(ZoneOffset.UTC));
System.out.println(now.withZoneSameInstant(ZoneId.of("UTC")));

Outputs:

2017-03-10T08:06:28.045Z
2017-03-10T08:06:28.045Z[UTC]

As you use the equals method for comparison, you check for object equivalence. Because of the described difference, the result of the evaluation is false.

When the normalized() method is used as proposed in the documentation, the comparison using equals will return true, as normalized() will return the corresponding ZoneOffset:

Normalizes the time-zone ID, returning a ZoneOffset where possible.

now.withZoneSameInstant(ZoneOffset.UTC)
    .equals(now.withZoneSameInstant(ZoneId.of("UTC").normalized())); // true

As the documentation states, if you use "Z" or "+0" as input id, of will return the ZoneOffset directly and there is no need to call normalized():

now.withZoneSameInstant(ZoneOffset.UTC).equals(now.withZoneSameInstant(ZoneId.of("Z"))); //true
now.withZoneSameInstant(ZoneOffset.UTC).equals(now.withZoneSameInstant(ZoneId.of("+0"))); //true

To check if they store the same date time, you can use the isEqual method instead:

now.withZoneSameInstant(ZoneOffset.UTC)
    .isEqual(now.withZoneSameInstant(ZoneId.of("UTC"))); // true

Sample

System.out.println("equals - ZoneId.of(\"UTC\"): " + nowZoneOffset
        .equals(now.withZoneSameInstant(ZoneId.of("UTC"))));
System.out.println("equals - ZoneId.of(\"UTC\").normalized(): " + nowZoneOffset
        .equals(now.withZoneSameInstant(ZoneId.of("UTC").normalized())));
System.out.println("equals - ZoneId.of(\"Z\"): " + nowZoneOffset
        .equals(now.withZoneSameInstant(ZoneId.of("Z"))));
System.out.println("equals - ZoneId.of(\"+0\"): " + nowZoneOffset
        .equals(now.withZoneSameInstant(ZoneId.of("+0"))));
System.out.println("isEqual - ZoneId.of(\"UTC\"): "+ nowZoneOffset
        .isEqual(now.withZoneSameInstant(ZoneId.of("UTC"))));

Output:

equals - ZoneId.of("UTC"): false
equals - ZoneId.of("UTC").normalized(): true
equals - ZoneId.of("Z"): true
equals - ZoneId.of("+0"): true
isEqual - ZoneId.of("UTC"): true

What is Unicode, UTF-8, UTF-16?

UTF stands for stands for Unicode Transformation Format.Basically in today's world there are scripts written in hundreds of other languages, formats not covered by the basic ASCII used earlier. Hence, UTF came into existence.

UTF-8 has character encoding capabilities and its code unit is 8 bits while that for UTF-16 it is 16 bits.

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given in

The problem is your query returned false meaning there was an error in your query. After your query you could do the following:

if (!$result) {
    die(mysqli_error($link));
}

Or you could combine it with your query:

$results = mysqli_query($link, $query) or die(mysqli_error($link));

That will print out your error.

Also... you need to sanitize your input. You can't just take user input and put that into a query. Try this:

$query = "SELECT * FROM shopsy_db WHERE name LIKE '%" . mysqli_real_escape_string($link, $searchTerm) . "%'";

In reply to: Table 'sookehhh_shopsy_db.sookehhh_shopsy_db' doesn't exist

Are you sure the table name is sookehhh_shopsy_db? maybe it's really like users or something.

Getting "unixtime" in Java

Avoid the Date object creation w/ System.currentTimeMillis(). A divide by 1000 gets you to Unix epoch.

As mentioned in a comment, you typically want a primitive long (lower-case-l long) not a boxed object long (capital-L Long) for the unixTime variable's type.

long unixTime = System.currentTimeMillis() / 1000L;

How can I style a PHP echo text?

Echo inside an HTML element with class and style the element:

echo "<span class='name'>" . $ip['cityName'] . "</span>";

What is path of JDK on Mac ?

Have a look and see if the the JDK is at:

Library/Java/JavaVirtualMachines/ Or /System/Library/Java/JavaVirtualMachines/

Check this earlier SO post: JDK on OSX 10.7 Lion

trim left characters in sql server?

You can use LEN in combination with SUBSTRING:

SELECT SUBSTRING(myColumn, 7, LEN(myColumn)) from myTable

Font.createFont(..) set color and size (java.awt.Font)

To set the color of a font, you must first initialize the color by doing this:

Color maroon = new Color (128, 0, 0);

Once you've done that, you then put:

Font font = new Font ("Courier New", 1, 25); //Initializes the font
c.setColor (maroon); //Sets the color of the font
c.setFont (font); //Sets the font
c.drawString ("Your text here", locationX, locationY); //Outputs the string

Note: The 1 represents the type of font and this can be used to replace Font.PLAIN and the 25 represents the size of your font.

addID in jQuery?

I've used something like this before which addresses @scunliffes concern. It finds all instances of items with a class of (in this case .button), and assigns an ID and appends its index to the id name:

_x000D_
_x000D_
$(".button").attr('id', function (index) {_x000D_
 return "button-" + index;_x000D_
});
_x000D_
_x000D_
_x000D_

So let's say you have 3 items with the class name of .button on a page. The result would be adding a unique ID to all of them (in addition to their class of "button").

In this case, #button-0, #button-1, #button-2, respectively. This can come in very handy. Simply replace ".button" in the first line with whatever class you want to target, and replace "button" in the return statement with whatever you'd like your unique ID to be. Hope this helps!

Host 'xxx.xx.xxx.xxx' is not allowed to connect to this MySQL server

Just perform the following steps:

1a) Connect to mysql (via localhost)

mysql -uroot -p

1b) If the mysql server is running in Kubernetes (K8s) and being accessed via a NodePort

kubectl exec -it [pod-name] -- /bin/bash
mysql -uroot -p
  1. Create user

    CREATE USER 'user'@'%' IDENTIFIED BY 'password';

  2. Grant permissions

    GRANT ALL PRIVILEGES ON *.* TO 'user'@'%' WITH GRANT OPTION;

  3. Flush privileges

    FLUSH PRIVILEGES;

UnicodeDecodeError when reading CSV file in Pandas with Python

I am using Jupyter-notebook. And in my case, it was showing the file in the wrong format. The 'encoding' option was not working. So I save the csv in utf-8 format, and it works.

Parse string to DateTime in C#

DateTime.Parse() should work fine for that string format. Reference:

http://msdn.microsoft.com/en-us/library/1k1skd40.aspx#Y1240

Is it throwing a FormatException for you?

What is the maximum characters for the NVARCHAR(MAX)?

The max size for a column of type NVARCHAR(MAX) is 2 GByte of storage.

Since NVARCHAR uses 2 bytes per character, that's approx. 1 billion characters.

Leo Tolstoj's War and Peace is a 1'440 page book, containing about 600'000 words - so that might be 6 million characters - well rounded up. So you could stick about 166 copies of the entire War and Peace book into each NVARCHAR(MAX) column.

Is that enough space for your needs? :-)

Cannot attach the file *.mdf as database

You already have an old copy of that database installed in Server Explorer. So its a simple naming collision in the Server Object Explorer / SQL server. You likely created the same database Catalog Name already before you decided to move it to the Apps_Data folder. So that Database name already exists and just needs to be deleted.

Just go into Visual Studio > View > SQL Server Object Explorer and delete the old database name and its connection. Retry your app again and it should install the .mdf file in App_Data and create the same exact database again in the Server Explorer.

LEFT JOIN in LINQ to entities?

You can read an article i have written for joins in LINQ here

var query = 
from  u in Repo.T_Benutzer
join bg in Repo.T_Benutzer_Benutzergruppen
    on u.BE_ID equals bg.BEBG_BE
into temp
from j in temp.DefaultIfEmpty()
select new
{
    BE_User = u.BE_User,
    BEBG_BG = (int?)j.BEBG_BG// == null ? -1 : j.BEBG_BG
            //, bg.Name 
}

The following is the equivalent using extension methods:

var query = 
Repo.T_Benutzer
.GroupJoin
(
    Repo.T_Benutzer_Benutzergruppen,
    x=>x.BE_ID,
    x=>x.BEBG_BE,
    (o,i)=>new {o,i}
)
.SelectMany
(
    x => x.i.DefaultIfEmpty(),
    (o,i) => new
    {
        BE_User = o.o.BE_User,
        BEBG_BG = (int?)i.BEBG_BG
    }
);

Regular Expressions- Match Anything

(.*?) does not work for me. I am trying to match comments surrounded by /* */, which may contain multiple lines.

Try this:

([a]|[^a])

This regex matches a or anything else expect a. Absolutely, it means matching everything.

BTW, in my situation, /\*([a]|[^a])*/ matches C style comments.

Thank @mpen for a more concise way.

[\s\S]

c# open file with default application and parameters

I converted the VB code in the blog post linked by xsl to C# and modified it a bit:

public static bool TryGetRegisteredApplication(
                     string extension, out string registeredApp)
{
    string extensionId = GetClassesRootKeyDefaultValue(extension);
    if (extensionId == null)
    {
        registeredApp = null;
        return false;
    }

    string openCommand = GetClassesRootKeyDefaultValue(
            Path.Combine(new[] {extensionId, "shell", "open", "command"}));

    if (openCommand == null)
    {
        registeredApp = null;
        return false;
    }

    registeredApp = openCommand
                     .Replace("%1", string.Empty)
                     .Replace("\"", string.Empty)
                     .Trim();
    return true;
}

private static string GetClassesRootKeyDefaultValue(string keyPath)
{
    using (var key = Registry.ClassesRoot.OpenSubKey(keyPath))
    {
        if (key == null)
        {
            return null;
        }

        var defaultValue = key.GetValue(null);
        if (defaultValue == null)
        {
            return null;
        }

        return defaultValue.ToString();
    }
}

EDIT - this is unreliable. See Finding the default application for opening a particular file type on Windows.

org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing

your issue will be resolved by properly defining cascading depedencies or by saving the referenced entities before saving the entity that references. Defining cascading is really tricky to get right because of all the subtle variations in how they are used.

Here is how you can define cascades:

@Entity
public class Userrole implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long userroleid;

    private Timestamp createddate;

    private Timestamp deleteddate;

    private String isactive;

    //bi-directional many-to-one association to Role
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="ROLEID")
    private Role role;

    //bi-directional many-to-one association to User
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumn(name="USERID")
    private User user;

}

In this scenario, every time you save, update, delete, etc Userrole, the assocaited Role and User will also be saved, updated...

Again, if your use case demands that you do not modify User or Role when updating Userrole, then simply save User or Role before modifying Userrole

Additionally, bidirectional relationships have a one-way ownership. In this case, User owns Bloodgroup. Therefore, cascades will only proceed from User -> Bloodgroup. Again, you need to save User into the database (attach it or make it non-transient) in order to associate it with Bloodgroup.

convert double to int

My ways are :

 - Convert.ToInt32(double_value)
 - (int)double_value
 - Int32.Parse(double_value.ToString());

CSS : center form in page horizontally and vertically

if you use a negative translateX/Y width and height are not necessary and the style is really short

_x000D_
_x000D_
#form_login {
    left      : 50%;
    top       : 50%;
    position  : absolute;
    transform : translate(-50%, -50%);
}
_x000D_
<form id="form_login">
  <p> 
      <input type="text" id="username" placeholder="username" />
  </p>
  <p>
      <input type="password" id="password" placeholder="password" />
  </p>
  <p>
      <input type="text" id="server" placeholder="server" />
  </p>
  <p>
      <button id="submitbutton" type="button">Se connecter</button>
  </p>
</form>
_x000D_
_x000D_
_x000D_


Alternatively you could use display: grid (check the full page view)

_x000D_
_x000D_
body {
   margin        : 0;
   padding       : 0;
   display       : grid;
   place-content : center;
   min-height    : 100vh;
}
_x000D_
<form id="form_login">
  <p> 
      <input type="text" id="username" placeholder="username" />
  </p>
  <p>
      <input type="password" id="password" placeholder="password" />
  </p>
  <p>
      <input type="text" id="server" placeholder="server" />
  </p>
  <p>
      <button id="submitbutton" type="button">Se connecter</button>
  </p>
</form>
_x000D_
_x000D_
_x000D_

Best way to store chat messages in a database?

There's nothing wrong with saving the whole history in the database, they are prepared for that kind of tasks.

Actually you can find here in Stack Overflow a link to an example schema for a chat: example

If you are still worried for the size, you could apply some optimizations to group messages, like adding a buffer to your application that you only push after some time (like 1 minute or so); that way you would avoid having only 1 line messages

fastest MD5 Implementation in JavaScript

I found a number of articles on this subject. They all suggested Joseph Meyers implementation.

see: http://jsperf.com/md5-shootout on some tests

in My quest for the ultimate speed i looked at this code, an i saw that it could be improved. So i created a new JS script based on the Joseph Meyers code.

see Improved Jospeh Meyers code

Google Chrome redirecting localhost to https

This can be caused by a cached https redirect, and can be fixed by clearing the cache manually as in Adiyat Mubarak's answer.

But if you are visiting localhost you likely are a developer, in which case you will find a cache clearing chrome extension such as "classic cache killer" (see e.g. https://chrome.google.com/webstore/search/classic%20cache%20killer?hl=en) useful in a variety of situations, and likely already have one installed.

So the quick fix is: Install a cache killer (if you don't have one already), turn it on, and reload the page. Done!

how to enable sqlite3 for php?

For PHP7, use

sudo apt-get install php7.0-sqlite3

and restart Apache

sudo apache2ctl restart

Remove border radius from Select tag in bootstrap 3

In addition to border-radius: 0, add -webkit-appearance: none;.

change type of input field with jQuery

An ultimate way to use jQuery:


Leave the original input field hidden from the screen.

$("#Password").hide(); //Hide it first
var old_id = $("#Password").attr("id"); //Store ID of hidden input for later use
$("#Password").attr("id","Password_hidden"); //Change ID for hidden input

Create new input field on the fly by JavaScript.

var new_input = document.createElement("input");

Migrate the ID and value from hidden input field to the new input field.

new_input.setAttribute("id", old_id); //Assign old hidden input ID to new input
new_input.setAttribute("type","text"); //Set proper type
new_input.value = $("#Password_hidden").val(); //Transfer the value to new input
$("#Password_hidden").after(new_input); //Add new input right behind the hidden input

To get around the error on IE like type property cannot be changed, you may find this useful as belows:

Attach click/focus/change event to new input element, in order to trigger the same event on hidden input.

$(new_input).click(function(){$("#Password_hidden").click();});
//Replicate above line for all other events like focus, change and so on...

Old hidden input element is still inside the DOM so will react with the event triggered by new input element. As ID is swapped, new input element will act like the old one and respond to any function call to old hidden input's ID, but looks different.

A little bit tricky but WORKS!!! ;-)

How to fluently build JSON in Java?

I am using the org.json library and found it to be nice and friendly.

Example:

String jsonString = new JSONObject()
                  .put("JSON1", "Hello World!")
                  .put("JSON2", "Hello my World!")
                  .put("JSON3", new JSONObject().put("key1", "value1"))
                  .toString();

System.out.println(jsonString);

OUTPUT:

{"JSON2":"Hello my World!","JSON3":{"key1":"value1"},"JSON1":"Hello World!"}

MySQL join with where clause

You need to put it in the join clause, not the where:

SELECT *
FROM categories
LEFT JOIN user_category_subscriptions ON 
    user_category_subscriptions.category_id = categories.category_id
    and user_category_subscriptions.user_id =1

See, with an inner join, putting a clause in the join or the where is equivalent. However, with an outer join, they are vastly different.

As a join condition, you specify the rowset that you will be joining to the table. This means that it evaluates user_id = 1 first, and takes the subset of user_category_subscriptions with a user_id of 1 to join to all of the rows in categories. This will give you all of the rows in categories, while only the categories that this particular user has subscribed to will have any information in the user_category_subscriptions columns. Of course, all other categories will be populated with null in the user_category_subscriptions columns.

Conversely, a where clause does the join, and then reduces the rowset. So, this does all of the joins and then eliminates all rows where user_id doesn't equal 1. You're left with an inefficient way to get an inner join.

Hopefully this helps!

Bitbucket git credentials if signed up with Google

Update as at September, 2019:

This whole process is now way easier than it used to be. It doesn't matter if your auth style is regular or Google-dependent, it works regardless. Follow these four easy steps:

  • Visit this link and enter your email.
  • Check your mail for the reactivation email and click the big blue button therein.
  • Change your password!

I hope this helps. Merry coding!

Symfony2 Setting a default choice field selection

Setting default choice for symfony2 radio button

            $builder->add('range_options', 'choice', array(
                'choices' => array('day'=>'Day', 'week'=>'Week', 'month'=>'Month'),
                'data'=>'day', //set default value 
                'required'=>true,
                'empty_data'=>null,
                'multiple'=>false,
                'expanded'=> true                   
        ))

Inline comments for Bash?

How about storing it in a variable?

#extraargs=-F
ls -l $extraargs -a /etc

Does Java support default parameter values?

No. In general Java doesn't have much (any) syntactic sugar, since they tried to make a simple language.

How to style a div to be a responsive square?

This is what I came up with. Here is a fiddle.

First, I need three wrapper elements for both a square shape and centered text.

<div><div><div>Lorem ipsum dolor sit amet, consectetuer adipiscing elit,
sed diam nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat
volutpat.</div></div></div>

This is the stylecheet. It makes use of two techniques, one for square shapes and one for centered text.

body > div {
    position:relative;
    height:0;
    width:50%; padding-bottom:50%;
}

body > div > div {
    position:absolute; top:0;
    height:100%; width:100%;
    display:table;
    border:1px solid #000;
    margin:1em;
}

body > div > div > div{
    display:table-cell;
    vertical-align:middle; text-align:center;
    padding:1em;
}

LaTeX table too wide. How to make it fit?

You can use these options as well, either use \footnotesize or \tiny. This would really help in fitting big tables.

\begin{table}[htbp]
\footnotesize
\caption{Information on making the table size small}
\label{table:table1}
\begin{tabular}{ll}
    \toprule
    S.No       & HMD           \\
    \midrule
    1          & HTC Vive \\
    2          & HTC Vive Pro   \\
    \bottomrule
\end{tabular}
\end{table}

How do I list loaded plugins in Vim?

The problem with :scriptnames, :commands, :functions, and similar Vim commands, is that they display information in a large slab of text, which is very hard to visually parse.

To get around this, I wrote Headlights, a plugin that adds a menu to Vim showing all loaded plugins, TextMate style. The added benefit is that it shows plugin commands, mappings, files, and other bits and pieces.

How to call a function, PostgreSQL

The function call still should be a valid SQL statement:

SELECT "saveUser"(3, 'asd','asd','asd','asd','asd');

Escaping single quotes in JavaScript string for JavaScript evaluation

Only this worked for me:

searchKeyword.replace(/'/g, "\\\'");//searchKeyword contains "d'av"

So, the result variable will contain "d\'av".

I don't know why with the RegEx didn't work, maybe because of the JS framework that I'm using (Backbone.js)

How to handle onchange event on input type=file in jQuery?

This jsfiddle works fine for me.

$(document).delegate(':file', 'change', function() {
    console.log(this);
});

Note: .delegate() is the fastest event-binding method for jQuery < 1.7: event-binding methods

In Spring MVC, how can I set the mime type header when using @ResponseBody

Register org.springframework.http.converter.json.MappingJacksonHttpMessageConverter as the message converter and return the object directly from the method.

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
  <property name="webBindingInitializer">
    <bean class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer"/>
  </property>
  <property name="messageConverters">
    <list>
      <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
    </list>
  </property>
</bean>

and the controller:

@RequestMapping(method=RequestMethod.GET, value="foo/bar")
public @ResponseBody Object fooBar(){
    return myService.getActualObject();
}

This requires the dependency org.springframework:spring-webmvc.

UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only

The answer of Shyam was right. I already faced with this issue before. It's not a problem, it's a SPRING feature. "Transaction rolled back because it has been marked as rollback-only" is acceptable.

Conclusion

  • USE REQUIRES_NEW if you want to commit what did you do before exception (Local commit)
  • USE REQUIRED if you want to commit only when all processes are done (Global commit) And you just need to ignore "Transaction rolled back because it has been marked as rollback-only" exception. But you need to try-catch out side the caller processNextRegistrationMessage() to have a meaning log.

Let's me explain more detail:

Question: How many Transaction we have? Answer: Only one

Because you config the PROPAGATION is PROPAGATION_REQUIRED so that the @Transaction persist() is using the same transaction with the caller-processNextRegistrationMessage(). Actually, when we get an exception, the Spring will set rollBackOnly for the TransactionManager so the Spring will rollback just only one Transaction.

Question: But we have a try-catch outside (), why does it happen this exception? Answer Because of unique Transaction

  1. When persist() method has an exception
  2. Go to the catch outside

    Spring will set the rollBackOnly to true -> it determine we must 
    rollback the caller (processNextRegistrationMessage) also.
    
  3. The persist() will rollback itself first.

  4. Throw an UnexpectedRollbackException to inform that, we need to rollback the caller also.
  5. The try-catch in run() will catch UnexpectedRollbackException and print the stack trace

Question: Why we change PROPAGATION to REQUIRES_NEW, it works?

Answer: Because now the processNextRegistrationMessage() and persist() are in the different transaction so that they only rollback their transaction.

Thanks

How do I get the name of the active user via the command line in OS X?

getting username in MAC terminal is easy...

I generally use whoami in terminal...

For example, in this case, I needed that to install Tomcat Server...

enter image description here

How to use template module with different set of variables?

I had a similar problem to solve, here is a simple solution of how to pass variables to template files, the trick is to write the template file taking advantage of the variable. You need to create a dictionary (list is also possible), which holds the set of variables corresponding to each of the file. Then within the template file access them.

see below:

the template file: test_file.j2
# {{ ansible_managed }} created by [email protected]

{% set dkey  = (item | splitext)[0]  %}
{% set fname = test_vars[dkey].name  %}
{% set fip   = test_vars[dkey].ip    %}
{% set fport = test_vars[dkey].port  %}
filename: {{ fname }}
ip address: {{ fip }}
port: {{ fport }}

the playbook

---
#
# file: template_test.yml
# author: [email protected]
#
# description: playbook to demonstrate passing variables to template files
#
# this playbook will create 3 files from a single template, with different
# variables passed for each of the invocation
#
# usage:
# ansible-playbook -i "localhost," template_test.yml

- name: template variables testing
  hosts: all
  gather_facts: false

  vars:
    ansible_connection: local
    dest_dir: "/tmp/ansible_template_test/"
    test_files:
      - file_01.txt
      - file_02.txt
      - file_03.txt
    test_vars:
      file_01:
        name: file_01.txt
        ip: 10.0.0.1
        port: 8001
      file_02:
        name: file_02.txt
        ip: 10.0.0.2
        port: 8002
      file_03:
        name: file_03.txt
        ip: 10.0.0.3
        port: 8003

  tasks:
    - name: copy the files
      template:
        src: test_file.j2
        dest: "{{ dest_dir }}/{{ item }}"
      with_items:
        - "{{ test_files }}"

How to change onClick handler dynamically?

Here is the YUI counterpart to the jQuery posts above.

<script>
  YAHOO.util.Event.onDOMReady(function() {   
    document.getElementById("foo").onclick =  function (){alert('foo');};
  });
</script>

Why is the Visual Studio 2015/2017/2019 Test Runner not discovering my xUnit v2 tests

I can provide a solution for an edge case I ran into a few days ago. It's not gonna be the solution that fits all of the scenarios described above, however, for the edge case I had it fixed it.

I had the same issue with most recent VS 2017 (version 15.5.7) and XUnit 2.3.1. The xunit.runner.visualstudio package was installed, however, the tests didn't show up in VisualStudio's built-in test explorer.

I was working on a legacy project that was targeting .NET framework 4.5. However, beginning with version 2.2. XUnit does not support .NET frameworks lower thant 4.5.2 (see Release Notes - XUnit 2.2: February 19, 2017

Changing the test project's target framework to a version >= 4.5.2 worked for me. You don't have to change the project's version that you're testing, it's just about the test project itself.

Windows command to convert Unix line endings?

Here's a simple unix2dos.bat file that preserves blank lines and exclamation points:

@echo off
setlocal DisableDelayedExpansion
for /f "tokens=1,* delims=:" %%k in ('findstr /n "^" %1') do echo.%%l

The output goes to standard out, so redirect unix2dos.bat output to a file if so desired.

It avoids the pitfalls of other previously proposed for /f batch loop solutions by:
1) Working with delayed expansion off, to avoid eating up exclamation marks.
2) Using the for /f tokenizer itself to remove the line number from the findstr /n output lines.
(Using findstr /n is necessary to also get blank lines: They would be dropped if for /f read directly from the input file.)

But, as Jeb pointed out in a comment below, the above solution has one drawback the others don't: It drops colons at the beginning of lines.

So 2020-04-06 update just for fun, here's another 1-liner based on findstr.exe, that seems to work fine without the above drawbacks:

@echo off
setlocal DisableDelayedExpansion
for /f "tokens=* delims=0123456789" %%l in ('findstr /n "^" %1') do echo%%l

The additional tricks are:
3) Use digits 0-9 as delimiters, so that tokens=* skips the initial line number.
4) Use the colon, inserted by findstr /n after the line number, as the token separator after the echo command.

I'll leave it to Jeb to explain if there are corner cases where echo:something might fail :-)
All I can say is that this last version successfully restored line endings on my huge batch library, so exceptions, if any, must be quite rare!

How to make the background DIV only transparent using CSS

.modalBackground
    {

        filter: alpha(opacity=80);
        opacity: 0.8;
        z-index: 10000;
    }

Difference Between Schema / Database in MySQL

Depends on the database server. MySQL doesn't care, its basically the same thing.

Oracle, DB2, and other enterprise level database solutions make a distinction. Usually a schema is a collection of tables and a Database is a collection of schemas.

Passive Link in Angular 2 - <a href=""> equivalent

I wonder why no one is suggesting routerLink and routerLinkActive (Angular 7)

<a [routerLink]="[ '/resources' ]" routerLinkActive="currentUrl!='/resources'">

I removed the href and now using this. When using href, it was going to the base url or reloading the same route again.

How to ORDER BY a SUM() in MySQL?

The problem I see here is that "sum" is an aggregate function.

first, you need to fix the query itself.

Select sum(c_counts + f_counts) total, [column to group sums by]
from table
group by [column to group sums by]

then, you can sort it:

Select *
from (query above) a
order by total

EDIT: But see post by Virat. Perhaps what you want is not the sum of your total fields over a group, but just the sum of those fields for each record. In that case, Virat has the right solution.

Converting bool to text in C++

C++ has proper strings so you might as well use them. They're in the standard header string. #include <string> to use them. No more strcat/strcpy buffer overruns; no more missing null terminators; no more messy manual memory management; proper counted strings with proper value semantics.

C++ has the ability to convert bools into human-readable representations too. We saw hints at it earlier with the iostream examples, but they're a bit limited because they can only blast the text to the console (or with fstreams, a file). Fortunately, the designers of C++ weren't complete idiots; we also have iostreams that are backed not by the console or a file, but by an automatically managed string buffer. They're called stringstreams. #include <sstream> to get them. Then we can say:

std::string bool_as_text(bool b)
{
    std::stringstream converter;
    converter << std::boolalpha << b;   // flag boolalpha calls converter.setf(std::ios_base::boolalpha)
    return converter.str();
}

Of course, we don't really want to type all that. Fortunately, C++ also has a convenient third-party library named Boost that can help us out here. Boost has a nice function called lexical_cast. We can use it thus:

boost::lexical_cast<std::string>(my_bool)

Now, it's true to say that this is higher overhead than some macro; stringstreams deal with locales which you might not care about, and create a dynamic string (with memory allocation) whereas the macro can yield a literal string, which avoids that. But on the flip side, the stringstream method can be used for a great many conversions between printable and internal representations. You can run 'em backwards; boost::lexical_cast<bool>("true") does the right thing, for example. You can use them with numbers and in fact any type with the right formatted I/O operators. So they're quite versatile and useful.

And if after all this your profiling and benchmarking reveals that the lexical_casts are an unacceptable bottleneck, that's when you should consider doing some macro horror.

How to subtract one month using moment.js?

For substracting in moment.js:

moment().subtract(1, 'months').format('MMM YYYY');

Documentation:

http://momentjs.com/docs/#/manipulating/subtract/

Before version 2.8.0, the moment#subtract(String, Number) syntax was also supported. It has been deprecated in favor of moment#subtract(Number, String).

  moment().subtract('seconds', 1); // Deprecated in 2.8.0
  moment().subtract(1, 'seconds');

As of 2.12.0 when decimal values are passed for days and months, they are rounded to the nearest integer. Weeks, quarters, and years are converted to days or months, and then rounded to the nearest integer.

  moment().subtract(1.5, 'months') == moment().subtract(2, 'months')
  moment().subtract(.7, 'years') == moment().subtract(8, 'months') //.7*12 = 8.4, rounded to 8

Error type 3 Error: Activity class {} does not exist

This happens when you do the following

  • connect your device/emulator
  • run the app from Android Studio (AS)
  • use/test the app and uninstall it from the device while it is still connected to your computer
  • try to run the app again from AS

AS thinks you still have the app in your device.

tl;dr - To resolve this, you can simply disconnect your device after uninstalling the app and reconnect it.

null terminating a string

Be very careful: NULL is a macro used mainly for pointers. The standard way of terminating a string is:

char *buffer;
...
buffer[end_position] = '\0';

This (below) works also but it is not a big difference between assigning an integer value to a int/short/long array and assigning a character value. This is why the first version is preferred and personally I like it better.

buffer[end_position] = 0; 

How to match all occurrences of a regex

if you have a regexp with groups:

str="A 54mpl3 string w1th 7 numbers scatter3r ar0und"
re=/(\d+)[m-t]/

you can use String's scan method to find matching groups:

str.scan re
#> [["54"], ["1"], ["3"]]

To find the matching pattern:

str.to_enum(:scan,re).map {$&}
#> ["54m", "1t", "3r"]

How to get the separate digits of an int number?

Here is my answer, I did it for myself and I hope it's simple enough for those who don't want to use the String approach or need a more math-y solution:

public static void reverseNumber2(int number) {

    int residual=0;
    residual=number%10;
    System.out.println(residual);

    while (residual!=number)  {
          number=(number-residual)/10;
          residual=number%10;
          System.out.println(residual);
    }
}

So I just get the units, print them out, substract them from the number, then divide that number by 10 - which is always without any floating stuff, since units are gone, repeat.

FPDF error: Some data has already been output, can't send PDF

For fpdf to work properly, there cannot be any output at all beside what fpdf generates. For example, this will work:

<?php
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

While this will not (note the leading space before the opening <? tag)

 <?php
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

Also, this will not work either (the echo will break it):

<?php
echo "About to create pdf";
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello World!');
$pdf->Output();
?>

I'm not sure about the drupal side of things, but I know that absolutely zero non-fpdf output is a requirement for fpdf to work.


add ob_start (); at the top and at the end add ob_end_flush();

<?php
    ob_start();
    require('fpdf.php');
    $pdf = new FPDF();
    $pdf->AddPage();
    $pdf->SetFont('Arial','B',16);
    $pdf->Cell(40,10,'Hello World!');
    $pdf->Output();
    ob_end_flush(); 
?>

give me an error as below:
FPDF error: Some data has already been output, can't send PDF

to over come this error: go to fpdf.php in that,goto line number 996

function Output($name='', $dest='')

after that make changes like this:

function Output($name='', $dest='') {   
    ob_clean();     //Output PDF to so

Hi do you have a session header on the top of your page. or any includes If you have then try to add this codes on top pf your page it should works fine.

<?

while (ob_get_level())
ob_end_clean();
header("Content-Encoding: None", true);

?>

cheers :-)


In my case i had set:

ini_set('display_errors', 'on');
error_reporting(E_ALL | E_STRICT);

When i made the request to generate the report, some warnings were displayed in the browser (like the usage of deprecated functions).
Turning off the display_errors option, the report was generated successfully.

Remove an array element and shift the remaining ones

If you are most concerned about code size and/or performance (also for WCET analysis, if you need one), I think this is probably going to be one of the more transparent solutions (for finding and removing elements):

unsigned int l=0, removed=0;

for( unsigned int i=0; i<count; i++ ) {
    if( array[i] != to_remove )
        array[l++] = array[i];
    else
        removed++;
}

count -= removed;

Make Https call using HttpClient

I had the same problem when connecting to GitHub, which requires a user agent. Thus it is sufficient to provide this rather than generating a certificate

var client = new HttpClient();

client.BaseAddress = new Uri("https://api.github.com");
client.DefaultRequestHeaders.Add(
    "Authorization",
    "token 123456789307d8c1d138ddb0848ede028ed30567");
client.DefaultRequestHeaders.Accept.Add(
    new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.Add(
    "User-Agent",
    "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36");

"/usr/bin/ld: cannot find -lz"

Try one of those three solution. It must work :) :

  1. sudo apt-get install zlib1g-dev
  2. sudo apt-get install libz-dev
  3. sudo apt-get install lib32z1-dev

In fact what is missing is not the lz command, but the development files for the zlib library.So you should install zlib1g-devlib for ex to get it.

For rhel7 like systems the package is zlib-devel

HTML5 Canvas: Zooming

Building on the suggestion of using drawImage you could also combine this with scale function.

So before you draw the image scale the context to the zoom level you want:

ctx.scale(2, 2) // Doubles size of anything draw to canvas.

I've created a small example here http://jsfiddle.net/mBzVR/4/ that uses drawImage and scale to zoom in on mousedown and out on mouseup.

endsWith in JavaScript

String.prototype.endWith = function (a) {
    var isExp = a.constructor.name === "RegExp",
    val = this;
    if (isExp === false) {
        a = escape(a);
        val = escape(val);
    } else
        a = a.toString().replace(/(^\/)|(\/$)/g, "");
    return eval("/" + a + "$/.test(val)");
}

// example
var str = "Hello";
alert(str.endWith("lo"));
alert(str.endWith(/l(o|a)/));

Run text file as commands in Bash

cat /path/* | bash

OR

cat commands.txt | bash

JavaScript and Threads

Here is just a way to simulate multi-threading in Javascript

Now I am going to create 3 threads which will calculate numbers addition, numbers can be divided with 13 and numbers can be divided with 3 till 10000000000. And these 3 functions are not able to run in same time as what Concurrency means. But I will show you a trick that will make these functions run recursively in the same time : jsFiddle

This code belongs to me.

Body Part

    <div class="div1">
    <input type="button" value="start/stop" onclick="_thread1.control ? _thread1.stop() : _thread1.start();" /><span>Counting summation of numbers till 10000000000</span> = <span id="1">0</span>
</div>
<div class="div2">
    <input type="button" value="start/stop" onclick="_thread2.control ? _thread2.stop() : _thread2.start();" /><span>Counting numbers can be divided with 13 till 10000000000</span> = <span id="2">0</span>
</div>
<div class="div3">
    <input type="button" value="start/stop" onclick="_thread3.control ? _thread3.stop() : _thread3.start();" /><span>Counting numbers can be divided with 3 till 10000000000</span> = <span id="3">0</span>
</div>

Javascript Part

var _thread1 = {//This is my thread as object
    control: false,//this is my control that will be used for start stop
    value: 0, //stores my result
    current: 0, //stores current number
    func: function () {   //this is my func that will run
        if (this.control) {      // checking for control to run
            if (this.current < 10000000000) {
                this.value += this.current;   
                document.getElementById("1").innerHTML = this.value;
                this.current++;
            }
        }
        setTimeout(function () {  // And here is the trick! setTimeout is a king that will help us simulate threading in javascript
            _thread1.func();    //You cannot use this.func() just try to call with your object name
        }, 0);
    },
    start: function () {
        this.control = true;   //start function
    },
    stop: function () {
        this.control = false;    //stop function
    },
    init: function () {
        setTimeout(function () {
            _thread1.func();    // the first call of our thread
        }, 0)
    }
};
var _thread2 = {
    control: false,
    value: 0,
    current: 0,
    func: function () {
        if (this.control) {
            if (this.current % 13 == 0) {
                this.value++;
            }
            this.current++;
            document.getElementById("2").innerHTML = this.value;
        }
        setTimeout(function () {
            _thread2.func();
        }, 0);
    },
    start: function () {
        this.control = true;
    },
    stop: function () {
        this.control = false;
    },
    init: function () {
        setTimeout(function () {
            _thread2.func();
        }, 0)
    }
};
var _thread3 = {
    control: false,
    value: 0,
    current: 0,
    func: function () {
        if (this.control) {
            if (this.current % 3 == 0) {
                this.value++;
            }
            this.current++;
            document.getElementById("3").innerHTML = this.value;
        }
        setTimeout(function () {
            _thread3.func();
        }, 0);
    },
    start: function () {
        this.control = true;
    },
    stop: function () {
        this.control = false;
    },
    init: function () {
        setTimeout(function () {
            _thread3.func();
        }, 0)
    }
};

_thread1.init();
_thread2.init();
_thread3.init();

I hope this way will be helpful.

Reading a .txt file using Scanner class in Java

No one seems to have addressed the fact that your not entering anything into an array at all. You are setting each int that is read to "i" and then outputting it.

for (int i =0 ; sc.HasNextLine();i++)
{
    array[i] = sc.NextInt();
}

Something to this effect will keep setting values of the array to the next integer read.

Than another for loop can display the numbers in the array.

for (int x=0;x< array.length ; x++)
{
    System.out.println("array[x]");
}

Is there a difference between using a dict literal and a dict constructor?

I think you have pointed out the most obvious difference. Apart from that,

the first doesn't need to lookup dict which should make it a tiny bit faster

the second looks up dict in locals() and then globals() and the finds the builtin, so you can switch the behaviour by defining a local called dict for example although I can't think of anywhere this would be a good idea apart from maybe when debugging

setting textColor in TextView in layout/main.xml main layout file not referencing colors.xml file. (It wants a #RRGGBB instead of @color/text_color)

You should write textcolor in xml as

android:textColor="@color/text_color"

or

android:textColor="#FFFFFF"

Variably modified array at file scope

Imho this is a flaw in many c compilers. I know for a fact that the compilers i worked with do not store a "static const"variable at an adress but replace the use in the code by the very constant. This can be verified as you will get the same checksum for the produced code when you use a preprocessors #define directive and when you use a static const variable.

Either way you should use static const variables instead of #defines whenever possible as the static const is type safe.

Multiple SQL joins

You can use something like this :

SELECT
    Books.BookTitle,
    Books.Edition,
    Books.Year,
    Books.Pages,
    Books.Rating,
    Categories.Category,
    Publishers.Publisher,
    Writers.LastName
FROM Books
INNER JOIN Categories_Books ON Categories_Books._Books_ISBN = Books._ISBN
INNER JOIN Categories ON Categories._CategoryID = Categories_Books._Categories_Category_ID
INNER JOIN Publishers ON Publishers._Publisherid = Books.PublisherID
INNER JOIN Writers_Books ON Writers_Books._Books_ISBN = Books._ISBN
INNER JOIN Writers ON Writers.Writers_Books = _Writers_WriterID.

What is the difference between dict.items() and dict.iteritems() in Python2?

You asked: 'Are there any applicable differences between dict.items() and dict.iteritems()'

This may help (for Python 2.x):

>>> d={1:'one',2:'two',3:'three'}
>>> type(d.items())
<type 'list'>
>>> type(d.iteritems())
<type 'dictionary-itemiterator'>

You can see that d.items() returns a list of tuples of the key, value pairs and d.iteritems() returns a dictionary-itemiterator.

As a list, d.items() is slice-able:

>>> l1=d.items()[0]
>>> l1
(1, 'one')   # an unordered value!

But would not have an __iter__ method:

>>> next(d.items())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list object is not an iterator

As an iterator, d.iteritems() is not slice-able:

>>> i1=d.iteritems()[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'dictionary-itemiterator' object is not subscriptable

But does have __iter__:

>>> next(d.iteritems())
(1, 'one')               # an unordered value!

So the items themselves are same -- the container delivering the items are different. One is a list, the other an iterator (depending on the Python version...)

So the applicable differences between dict.items() and dict.iteritems() are the same as the applicable differences between a list and an iterator.

How can the default node version be set using NVM?

change the default node version with nvm alias default 10.15.3 *

(replace mine version with your default version number)

you can check your default lists with nvm list

JCheckbox - ActionListener and ItemListener?

For reference, here's an sscce that illustrates the difference. Console:

SELECTED
ACTION_PERFORMED
DESELECTED
ACTION_PERFORMED

Code:

import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;

/** @see http://stackoverflow.com/q/9882845/230513 */
public class Listeners {

    private void display() {
        JFrame f = new JFrame("Listeners");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JCheckBox b = new JCheckBox("JCheckBox");
        b.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println(e.getID() == ActionEvent.ACTION_PERFORMED
                    ? "ACTION_PERFORMED" : e.getID());
            }
        });
        b.addItemListener(new ItemListener() {

            @Override
            public void itemStateChanged(ItemEvent e) {
                System.out.println(e.getStateChange() == ItemEvent.SELECTED
                    ? "SELECTED" : "DESELECTED");
            }
        });
        JPanel p = new JPanel();
        p.add(b);
        f.add(p);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Listeners().display();
            }
        });
    }
}

Editing legend (text) labels in ggplot

The legend titles can be labeled by specific aesthetic.

This can be achieved using the guides() or labs() functions from ggplot2 (more here and here). It allows you to add guide/legend properties using the aesthetic mapping.

Here's an example using the mtcars data set and labs():

ggplot(mtcars, aes(x=mpg, y=disp, size=hp, col=as.factor(cyl), shape=as.factor(gear))) +
  geom_point() +
  labs(x="miles per gallon", y="displacement", size="horsepower", 
       col="# of cylinders", shape="# of gears")

enter image description here

Answering the OP's question using guides():

# transforming the data from wide to long
require(reshape2)
dfm <- melt(df, id="TY")

# creating a scatterplot
ggplot(data = dfm, aes(x=TY, y=value, color=variable)) + 
  geom_point(size=5) +
  labs(title="Temperatures\n", x="TY [°C]", y="Txxx") +
  scale_color_manual(labels = c("T999", "T888"), values = c("blue", "red")) +
  theme_bw() +
  guides(color=guide_legend("my title"))  # add guide properties by aesthetic

enter image description here

How to read single Excel cell value

using Microsoft.Office.Interop.Excel;

string path = "C:\\Projects\\ExcelSingleValue\\Test.xlsx ";

Application excel = new Application();
Workbook wb = excel.Workbooks.Open(path);
Worksheet excelSheet = wb.ActiveSheet;

//Read the first cell
string test = excelSheet.Cells[1, 1].Value.ToString();

wb.Close();

This example used the 'Microsoft Excel 15.0 Object Library' but may be compatible with earlier versions of Interop and other libraries.

Why do people hate SQL cursors so much?

Can you post that cursor example or link to the question? There's probably an even better way than a recursive CTE.

In addition to other comments, cursors when used improperly (which is often) cause unnecessary page/row locks.

What integer hash function are good that accepts an integer hash key?

There's a nice overview over some hash algorithms at Eternally Confuzzled. I'd recommend Bob Jenkins' one-at-a-time hash which quickly reaches avalanche and therefore can be used for efficient hash table lookup.

Reverse Contents in Array

I would try to using pointers to solve this problem:

#include <iostream>

void displayArray(int table[], int size);

void rev(int table[], int size);


int main(int argc, char** argv) {

    int a[10] = { 1,2,3,4,5,6,7,8,9,10 };

    rev(a, 10);
    displayArray(a, 10);

    return 0;
}

void displayArray(int table[], int size) {
    for (int i = 0; i < size; i++) {
        std::cout << table[i] << " ";
    }
    std::cout << std::endl;
}

void rev(int table[], int size) {

    int *start = table;
    int *end = table + (size - 1);

    for (int i = 0; i < size; i++) {

        if (start < end) {
            int temp = *end;
            *end = *start;
            *start = temp;
        }

        start++;
        end--;
    }
}

calling Jquery function from javascript

//javascript function calling an jquery function

//In javascript part

function js_show_score()
{
     //we use so many javascript library, So please use 'jQuery' avoid '$'  
     jQuery(function(){ 
        //Call any jquery function
        show_score(); //jquery function
    });(jQuery);  
}

//In Jquery part

jQuery(function(){ 
//Jq Score function     
    function show_score()
    {   
        $('#score').val("10");
    }
});(jQuery); 

Jquery Chosen plugin - dynamically populate list by Ajax

The chosen answer is outdated, same goes to meltingice /ajax-chosen plugin.

With Select2 plugin got many bugs which is i can't resolve it.

Here my answer for this question.

I integrated my solution with function trigger after user type. Thanks to this answer : https://stackoverflow.com/a/5926782/4319179.

//setup before functions
  var typingTimer;                //timer identifier
  var doneTypingInterval = 2000;  //time in ms (2 seconds)
  var selectID = 'YourSelectId';    //Hold select id
  var selectData = [];           // data for unique id array

  //on keyup, start the countdown
  $('#' + selectID + '_chosen .chosen-choices input').keyup(function(){

      // Change No Result Match text to Searching.
      $('#' + selectID + '_chosen .no-results').html('Searching = "'+ $('#' + selectID + '_chosen .chosen-choices input').val() + '"');


      clearTimeout(typingTimer);  //Refresh Timer on keyup 
      if ($('#' + selectID + '_chosen .chosen-choices input').val()) {

           typingTimer = setTimeout(doneTyping, doneTypingInterval);  //Set timer back if got value on input

      }

  });

  //user is "finished typing," do something
  function doneTyping () {

      var inputData = $('#' + selectID + '_chosen .chosen-choices input').val();  //get input data

      $.ajax({
        url: "YourUrl",
         data: {data: inputData},
        type:'POST',
        dataType: "json",
        beforeSend: function(){
          // Change No Result Match to Getting Data beforesend
          $('#' + selectID + '_chosen .no-results').html('Getting Data = "'+$('#' + selectID + '_chosen .chosen-choices input').val()+'"');
    },
        success: function( data ) { 

          // iterate data before append
          $.map( data, function( item ) {

            // matching data eg: by id or something unique; if data match: <option> not append - else: append <option>
            // This will prevent from select the same thing twice.
            if($.inArray(item.attr_hash,selectData) == -1){

              // if not match then append in select
              $('#' + selectID ).append('<option id="'+item.id+'" data-id = "'+item.id+'">' + item.data + '</option>');

            }            

          });

          // Update chosen again after append <option>
          $('#' + selectID ).trigger("chosen:updated");

        }
      });

  }

  // Chosen event listen on input change eg: after select data / deselect this function will be trigger
  $('#' + selectID ).on('change', function() {

    // get select jquery object
    var domArray = $('#' + selectID ).find('option:selected');

    // empty array data
    selectData = [];

    for (var i = 0, length = domArray.length; i < length; i++ ){

      // Push unique data to array (for matching purpose)
      selectData.push( $(domArray[i]).data('id') );

    }

    // Replace select <option> to only selected option
    $('#' + selectID ).html(domArray);

    // Update chosen again after replace selected <option>
    $('#' + selectID ).trigger("chosen:updated");

  });

How do I get the XML root node with C#?

Agree with Jewes, XmlReader is the better way to go, especially if working with a larger XML document or processing multiple in a loop - no need to parse the entire document if you only need the document root.

Here's a simplified version, using XmlReader and MoveToContent().

http://msdn.microsoft.com/en-us/library/system.xml.xmlreader.movetocontent.aspx

using (XmlReader xmlReader = XmlReader.Create(p_fileName))
{
  if (xmlReader.MoveToContent() == XmlNodeType.Element)
    rootNodeName = xmlReader.Name;
}

How to set space between listView Items in Android

Instead of giving margin, you should give padding:

<ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:divider="@android:color/green"
    android:dividerHeight="4dp"
    android:layout_alignParentTop="true"
    android:padding="5dp" >

</ListView>

OR

<ListView
    android:id="@+id/listView1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:paddingTop="2dp"
    android:divider="@android:color/green"
    android:dividerHeight="4dp"
    android:paddingLeft="1dp"
    android:paddingRight="1dp"
    android:paddingBottom="2dp"
    android:paddingStart="0dp"
    android:paddingEnd="0dp" >

</ListView>

What is the purpose of backbone.js?

Is an MVC design pattern on the client side, believe me.. It's gonna save you tons of code, not to mention a more clean and clear code, a more easy to maintain code. Could be a little tricky at first, but believe me it's a great library.

How to hide action bar before activity is created, and then show it again?

The best way I find after reading all the available options is set main theme without ActionBar and then set up MyTheme in code in parent of all Activity.

Manifest:

<application
...
        android:theme="@android:style/Theme.Holo.Light.NoActionBar"
...>

BaseActivity:

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setTheme(R.style.GreenHoloTheme);
}

This way helps me to avoid ActionBar when application start!

MySQL LIKE IN()?

You can create an inline view or a temporary table, fill it with you values and issue this:

SELECT  *
FROM    fiberbox f
JOIN    (
        SELECT '%1740%' AS cond
        UNION ALL
        SELECT '%1938%' AS cond
        UNION ALL
        SELECT '%1940%' AS cond
        ) ?
ON      f.fiberBox LIKE cond

This, however, can return you multiple rows for a fiberbox that is something like '1740, 1938', so this query can fit you better:

SELECT  *
FROM    fiberbox f
WHERE   EXISTS
        (
        SELECT  1
        FROM    (
                SELECT '%1740%' AS cond
                UNION ALL
                SELECT '%1938%' AS cond
                UNION ALL
                SELECT '%1940%' AS cond
                ) ?
        WHERE   f.fiberbox LIKE cond
        )

Does Arduino use C or C++?

Arduino doesn't run either C or C++. It runs machine code compiled from either C, C++ or any other language that has a compiler for the Arduino instruction set.

C being a subset of C++, if Arduino can "run" C++ then it can "run" C.

If you don't already know C nor C++, you should probably start with C, just to get used to the whole "pointer" thing. You'll lose all the object inheritance capabilities though.

How can I split a shell command over multiple lines when using an IF statement?

The line-continuation will fail if you have whitespace (spaces or tab characters[1]) after the backslash and before the newline. With no such whitespace, your example works fine for me:

$ cat test.sh
if ! fab --fabfile=.deploy/fabfile.py \
   --forward-agent \
   --disable-known-hosts deploy:$target; then
     echo failed
else
     echo succeeded
fi

$ alias fab=true; . ./test.sh
succeeded
$ alias fab=false; . ./test.sh
failed

Some detail promoted from the comments: the line-continuation backslash in the shell is not really a special case; it is simply an instance of the general rule that a backslash "quotes" the immediately-following character, preventing any special treatment it would normally be subject to. In this case, the next character is a newline, and the special treatment being prevented is terminating the command. Normally, a quoted character winds up included literally in the command; a backslashed newline is instead deleted entirely. But otherwise, the mechanism is the same. Most importantly, the backslash only quotes the immediately-following character; if that character is a space or tab, you just get a literal space or tab, and any subsequent newline remains unquoted.

[1] or carriage returns, for that matter, as Czechnology points out. Bash does not get along with Windows-formatted text files, not even in WSL. Or Cygwin, but at least their Bash port has added a set -o igncr option that you can set to make it carriage-return-tolerant.

How to make the corners of a button round?

If you want change corner radius as well as want a ripple effect in button when pressed use this:-

  1. Put button_background.xml in drawable
<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="#F7941D">

    <item android:id="@android:id/mask">
        <shape android:shape="rectangle">
            <solid android:color="#F7941D" />
            <corners android:radius="10dp" />
        </shape>
    </item>

    <item android:id="@android:id/background">
        <shape android:shape="rectangle">
            <solid android:color="#FFFFFF" />
            <corners android:radius="10dp" />
        </shape>
    </item>

</ripple>
  1. Apply this background to your button
<Button
    android:background="@drawable/button_background"
    android:id="@+id/myBtn"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:text="My Button" />

Hide axis values but keep axis tick labels in matplotlib

to remove tickmarks entirely use:

ax.set_yticks([])
ax.set_xticks([])

otherwise ax.set_yticklabels([]) and ax.set_xticklabels([]) will keep tickmarks.

How to get a specific column value from a DataTable in c#

The table normally contains multiple rows. Use a loop and use row.Field<string>(0) to access the value of each row.

foreach(DataRow row in dt.Rows)
{
    string file = row.Field<string>("File");
}

You can also access it via index:

foreach(DataRow row in dt.Rows)
{
    string file = row.Field<string>(0);
}

If you expect only one row, you can also use the indexer of DataRowCollection:

string file = dt.Rows[0].Field<string>(0); 

Since this fails if the table is empty, use dt.Rows.Count to check if there is a row:

if(dt.Rows.Count > 0)
    file = dt.Rows[0].Field<string>(0);

Understanding SQL Server LOCKS on SELECT queries

A SELECT in SQL Server will place a shared lock on a table row - and a second SELECT would also require a shared lock, and those are compatible with one another.

So no - one SELECT cannot block another SELECT.

What the WITH (NOLOCK) query hint is used for is to be able to read data that's in the process of being inserted (by another connection) and that hasn't been committed yet.

Without that query hint, a SELECT might be blocked reading a table by an ongoing INSERT (or UPDATE) statement that places an exclusive lock on rows (or possibly a whole table), until that operation's transaction has been committed (or rolled back).

Problem of the WITH (NOLOCK) hint is: you might be reading data rows that aren't going to be inserted at all, in the end (if the INSERT transaction is rolled back) - so your e.g. report might show data that's never really been committed to the database.

There's another query hint that might be useful - WITH (READPAST). This instructs the SELECT command to just skip any rows that it attempts to read and that are locked exclusively. The SELECT will not block, and it will not read any "dirty" un-committed data - but it might skip some rows, e.g. not show all your rows in the table.

Login to Microsoft SQL Server Error: 18456

you can do in linux for mssql change password for sa account

sudo /opt/mssql/bin/mssql-conf setup

The license terms for this product can be downloaded from
 http://go.microsoft.com/fwlink/?LinkId=746388 Jump Jump
and found in /usr/share/doc/mssql-server/LICENSE.TXT.
Do you accept the license terms? [Yes/No]:yes
  Setting up Microsoft SQL Server
Enter the new SQL Server system administrator password:  --Enter strong password
Confirm the new SQL Server system administrator password: --Enter strong password
 starting Microsoft SQL Server...
 Enabling Microsoft SQL Server to run at boot...
Setup completed successfully.

HttpListener Access Denied

As an alternative that doesn't require elevation or netsh you could also use TcpListener for instance.

The following is a modified excerpt of this sample: https://github.com/googlesamples/oauth-apps-for-windows/tree/master/OAuthDesktopApp

// Generates state and PKCE values.
string state = randomDataBase64url(32);
string code_verifier = randomDataBase64url(32);
string code_challenge = base64urlencodeNoPadding(sha256(code_verifier));
const string code_challenge_method = "S256";

// Creates a redirect URI using an available port on the loopback address.
var listener = new TcpListener(IPAddress.Loopback, 0);
listener.Start();
string redirectURI = string.Format("http://{0}:{1}/", IPAddress.Loopback, ((IPEndPoint)listener.LocalEndpoint).Port);
output("redirect URI: " + redirectURI);

// Creates the OAuth 2.0 authorization request.
string authorizationRequest = string.Format("{0}?response_type=code&scope=openid%20profile&redirect_uri={1}&client_id={2}&state={3}&code_challenge={4}&code_challenge_method={5}",
    authorizationEndpoint,
    System.Uri.EscapeDataString(redirectURI),
    clientID,
    state,
    code_challenge,
    code_challenge_method);

// Opens request in the browser.
System.Diagnostics.Process.Start(authorizationRequest);

// Waits for the OAuth authorization response.
var client = await listener.AcceptTcpClientAsync();

// Read response.
var response = ReadString(client);

// Brings this app back to the foreground.
this.Activate();

// Sends an HTTP response to the browser.
WriteStringAsync(client, "<html><head><meta http-equiv='refresh' content='10;url=https://google.com'></head><body>Please close this window and return to the app.</body></html>").ContinueWith(t =>
{
    client.Dispose();
    listener.Stop();

    Console.WriteLine("HTTP server stopped.");
});

// TODO: Check the response here to get the authorization code and verify the code challenge

The read and write methods being:

private string ReadString(TcpClient client)
{
    var readBuffer = new byte[client.ReceiveBufferSize];
    string fullServerReply = null;

    using (var inStream = new MemoryStream())
    {
        var stream = client.GetStream();

        while (stream.DataAvailable)
        {
            var numberOfBytesRead = stream.Read(readBuffer, 0, readBuffer.Length);
            if (numberOfBytesRead <= 0)
                break;

            inStream.Write(readBuffer, 0, numberOfBytesRead);
        }

        fullServerReply = Encoding.UTF8.GetString(inStream.ToArray());
    }

    return fullServerReply;
}

private Task WriteStringAsync(TcpClient client, string str)
{
    return Task.Run(() =>
    {
        using (var writer = new StreamWriter(client.GetStream(), new UTF8Encoding(false)))
        {
            writer.Write("HTTP/1.0 200 OK");
            writer.Write(Environment.NewLine);
            writer.Write("Content-Type: text/html; charset=UTF-8");
            writer.Write(Environment.NewLine);
            writer.Write("Content-Length: " + str.Length);
            writer.Write(Environment.NewLine);
            writer.Write(Environment.NewLine);
            writer.Write(str);
        }
    });
}

Vector of structs initialization

You may also which to use aggregate initialization from a braced initialization list for situations like these.

#include <vector>
using namespace std;

struct subject {
    string name;
    int    marks;
    int    credits;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0},
      {"math"   , 20, 5}
    };
}

Sometimes however, the members of a struct may not be so simple, so you must give the compiler a hand in deducing its types.

So extending on the above.

#include <vector>
using namespace std;

struct assessment {
    int   points;
    int   total;
    float percentage;
};

struct subject {
    string name;
    int    marks;
    int    credits;
    vector<assessment> assessments;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0, {
                             assessment{1,3,0.33f},
                             assessment{2,3,0.66f},
                             assessment{3,3,1.00f}
                         }},
      {"math"   , 20, 5, {
                             assessment{2,4,0.50f}
                         }}
    };
}

Without the assessment in the braced initializer the compiler will fail when attempting to deduce the type.

The above has been compiled and tested with gcc in c++17. It should however work from c++11 and onward. In c++20 we may see the designator syntax, my hope is that it will allow for for the following

  {"english", 10, 0, .assessments{
                         {1,3,0.33f},
                         {2,3,0.66f},
                         {3,3,1.00f}
                     }},

source: http://en.cppreference.com/w/cpp/language/aggregate_initialization

Remove leading comma from a string

To turn a string into an array I usually use split()

> var s = ",'first string','more','even more'"
> s.split("','")
[",'first string", "more", "even more'"]

This is almost what you want. Now you just have to strip the first two and the last character:

> s.slice(2, s.length-1)
"first string','more','even more"

> s.slice(2, s.length-2).split("','");
["first string", "more", "even more"]

To extract a substring from a string I usually use slice() but substr() and substring() also do the job.

Copy file remotely with PowerShell

From PowerShell version 5 onwards (included in Windows Server 2016, downloadable as part of WMF 5 for earlier versions), this is possible with remoting. The benefit of this is that it works even if, for whatever reason, you can't access shares.

For this to work, the local session where copying is initiated must have PowerShell 5 or higher installed. The remote session does not need to have PowerShell 5 installed -- it works with PowerShell versions as low as 2, and Windows Server versions as low as 2008 R2.[1]

From server A, create a session to server B:

$b = New-PSSession B

And then, still from A:

Copy-Item -FromSession $b C:\Programs\temp\test.txt -Destination C:\Programs\temp\test.txt

Copying items to B is done with -ToSession. Note that local paths are used in both cases; you have to keep track of what server you're on.


[1]: when copying from or to a remote server that only has PowerShell 2, beware of this bug in PowerShell 5.1, which at the time of writing means recursive file copying doesn't work with -ToSession, an apparently copying doesn't work at all with -FromSession.

dd: How to calculate optimal blocksize?

As others have said, there is no universally correct block size; what is optimal for one situation or one piece of hardware may be terribly inefficient for another. Also, depending on the health of the disks it may be preferable to use a different block size than what is "optimal".

One thing that is pretty reliable on modern hardware is that the default block size of 512 bytes tends to be almost an order of magnitude slower than a more optimal alternative. When in doubt, I've found that 64K is a pretty solid modern default. Though 64K usually isn't THE optimal block size, in my experience it tends to be a lot more efficient than the default. 64K also has a pretty solid history of being reliably performant: You can find a message from the Eug-Lug mailing list, circa 2002, recommending a block size of 64K here: http://www.mail-archive.com/[email protected]/msg12073.html

For determining THE optimal output block size, I've written the following script that tests writing a 128M test file with dd at a range of different block sizes, from the default of 512 bytes to a maximum of 64M. Be warned, this script uses dd internally, so use with caution.

dd_obs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_obs_testfile}
TEST_FILE_EXISTS=0
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=1; fi
TEST_FILE_SIZE=134217728

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Calculate number of segments required to copy
  COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))

  if [ $COUNT -le 0 ]; then
    echo "Block size of $BLOCK_SIZE estimated to require $COUNT blocks, aborting further tests."
    break
  fi

  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Create a test file with the specified block size
  DD_RESULT=$(dd if=/dev/zero of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync 2>&1 1>/dev/null)

  # Extract the transfer rate from dd's STDERR output
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  # Clean up the test file if we created one
  if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

  # Output the result
  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

View on GitHub

I've only tested this script on a Debian (Ubuntu) system and on OSX Yosemite, so it will probably take some tweaking to make work on other Unix flavors.

By default the command will create a test file named dd_obs_testfile in the current directory. Alternatively, you can provide a path to a custom test file by providing a path after the script name:

$ ./dd_obs_test.sh /path/to/disk/test_file

The output of the script is a list of the tested block sizes and their respective transfer rates like so:

$ ./dd_obs_test.sh
block size : transfer rate
       512 : 11.3 MB/s
      1024 : 22.1 MB/s
      2048 : 42.3 MB/s
      4096 : 75.2 MB/s
      8192 : 90.7 MB/s
     16384 : 101 MB/s
     32768 : 104 MB/s
     65536 : 108 MB/s
    131072 : 113 MB/s
    262144 : 112 MB/s
    524288 : 133 MB/s
   1048576 : 125 MB/s
   2097152 : 113 MB/s
   4194304 : 106 MB/s
   8388608 : 107 MB/s
  16777216 : 110 MB/s
  33554432 : 119 MB/s
  67108864 : 134 MB/s

(Note: The unit of the transfer rates will vary by OS)

To test optimal read block size, you could use more or less the same process, but instead of reading from /dev/zero and writing to the disk, you'd read from the disk and write to /dev/null. A script to do this might look like so:

dd_ibs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_ibs_testfile}
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=$?; fi
TEST_FILE_SIZE=134217728

# Exit if file exists
if [ -e $TEST_FILE ]; then
  echo "Test file $TEST_FILE exists, aborting."
  exit 1
fi
TEST_FILE_EXISTS=1

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Create test file
echo 'Generating test file...'
BLOCK_SIZE=65536
COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))
dd if=/dev/urandom of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync > /dev/null 2>&1

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Read test file out to /dev/null with specified block size
  DD_RESULT=$(dd if=$TEST_FILE of=/dev/null bs=$BLOCK_SIZE 2>&1 1>/dev/null)

  # Extract transfer rate
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

# Clean up the test file if we created one
if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

View on GitHub

An important difference in this case is that the test file is a file that is written by the script. Do not point this command at an existing file or the existing file will be overwritten with zeroes!

For my particular hardware I found that 128K was the most optimal input block size on a HDD and 32K was most optimal on a SSD.

Though this answer covers most of my findings, I've run into this situation enough times that I wrote a blog post about it: http://blog.tdg5.com/tuning-dd-block-size/ You can find more specifics on the tests I performed there.

How do I retrieve my MySQL username and password?

If you have root access to the server where mysql is running you should stop the mysql server using this command

sudo service mysql stop

Now start mysql using this command

sudo /usr/sbin/mysqld --skip-grant-tables  --skip-networking &

Now you can login to mysql using

sudo mysql
FLUSH PRIVILEGES;
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('MyNewPass');

Full instructions can be found here http://www.techmatterz.com/recover-mysql-root-password/

How to find out which JavaScript events fired?

You can use getEventListeners in your Google Chrome developer console.

getEventListeners(object) returns the event listeners registered on the specified object.

getEventListeners(document.querySelector('option[value=Closed]'));

New to MongoDB Can not run command mongo

Create the data/db directory in your main (windows) partition:

C:\> mkdir \data
C:\> mkdir \data\db

and then go to your mongo_directory/bin and run mongod.exe:

C:\> cd \my_mongo_dir\bin

C:\my_mongo_dir\bin> mongod

DON't CLOSE THIS WINDOW

Now in a different command prompt window run Mongo:

C:\> cd \my_mongo_dir\bin
C:\my_mongo_dir\bin> mongo

(REMEMBER YOU HAVE TO KEEP THAT OTHER WINDOW OPEN)

This solved the problem for me.

Enabling CORS in Cloud Functions for Firebase

No CORS solutions worked for me... till now!

Not sure if anyone else ran into the same issue I did, but I set up CORS like 5 different ways from examples I found and nothing seemed to work. I set up a minimal example with Plunker to see if it was really a bug, but the example ran beautifully. I decided to check the firebase functions logs (found in the firebase console) to see if that could tell me anything. I had a couple errors in my node server code, not CORS related, that when I debugged released me of my CORS error message. I don't know why code errors unrelated to CORS returns a CORS error response, but it led me down the wrong rabbit hole for a good number of hours...

tl;dr - check your firebase function logs if no CORS solutions work and debug any errros you have

How to remove trailing and leading whitespace for user-provided input in a batch file?

The solution below works very well for me.

Only 4 lines and works with most (all?) characters.


Solution:

:Trim
SetLocal EnableDelayedExpansion
set Params=%*
for /f "tokens=1*" %%a in ("!Params!") do EndLocal & set %1=%%b
exit /b

Test:

@echo off

call :Test1 & call :Test2 & call :Test3 & exit /b

:Trim
SetLocal EnableDelayedExpansion
set Params=%*
for /f "tokens=1*" %%a in ("!Params!") do EndLocal & set %1=%%b
exit /b

:Test1
set Value=   a b c   
set Expected=a b c
call :Trim Actual %Value%
if "%Expected%" == "%Actual%" (echo Test1 passed) else (echo Test1 failed)
exit /b

:Test2
SetLocal EnableDelayedExpansion
set Value=   a \ / : * ? " ' < > | ` ~ @ # $ [ ] & ( ) + - _ = z    
set Expected=a \ / : * ? " ' < > | ` ~ @ # $ [ ] & ( ) + - _ = z
call :Trim Actual !Value!
if !Expected! == !Actual! (echo Test2 passed) else (echo Test2 failed)
exit /b

:Test3
set /p Value="Enter string to trim: " %=%
echo Before: [%Value%]
call :Trim Value %Value%
echo After : [%Value%]
exit /b