Programs & Examples On #Captcha

Captcha is a type of challenge-response test used in computing as an attempt to ensure that the response is given by a human being and not generated by a computer.

How does Google reCAPTCHA v2 work behind the scenes?

My Bots are running well against ReCaptcha.

Here my Solution.

Let your Bot do this Steps:

First write a Human Mouse Move Function to move your Mouse like a B-Spline (Ask me for Source Code). This is the most important Point.

Also use for better results a VPN like https://www.purevpn.com

For every Recpatcha do these Steps:

  1. If you use VPN switch IP first

  2. Clear all Browser Cookies

  3. Clear all Browser Cache

  4. Set one of these Useragents by Random:

    a. Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)

    b. Mozilla/5.0 (Windows NT 6.1; WOW64; rv:44.0) Gecko/20100101 Firefox/44.0

5 Move your Mouse with the Human Mouse Move Funktion from a RandomPoint into the I am not a Robot Image every time with different 10x10 Randomrange

  1. Then Click ever with random delay between

    WM_LBUTTONDOWN

    and

    WM_LBUTTONUP

  2. Take Screenshot from Image Captcha

  3. Send Screenshot to

    http://www.deathbycaptcha.com

    or

    https://2captcha.com

and let they solve.

  1. After receiving click cooridinates from captcha solver use your Human Mouse move Funktion to move and Click Recaptcha Images

  2. Use your Human Mouse Move Funktion to move and Click to the Recaptcha Verify Button

In 75% all trys Recaptcha will solved

Chears Google

Tom

ReCaptcha API v2 Styling

I am just adding this kind of solution / quick fix so it won't get lost in case of a broken link.

Link to this solution "Want to add link How to resize the Google noCAPTCHA reCAPTCHA | The Geek Goddess" was provided by Vikram Singh Saini and simply outlines that you could use inline CSS to enforce framing of the iframe.

// Scale the frame using inline CSS
 <div class="g-recaptcha" data-theme="light" 
 data-sitekey="XXXXXXXXXXXXX" 

 style="transform:scale(0.77);
 -webkit-transform:scale(0.77);
 transform-origin:0 0;
  -webkit-transform-origin:0 0;

 ">
</div> 

// Scale the images using a stylesheet
<style>
#rc-imageselect, .g-recaptcha {
  transform:scale(0.77);
  -webkit-transform:scale(0.77);
  transform-origin:0 0;
  -webkit-transform-origin:0 0;
}
</style>

How do I show multiple recaptchas on a single page?

A good option is to generate a recaptcha input for each form on the fly (I've done it with two but you could probably do three or more forms). I'm using jQuery, jQuery validation, and jQuery form plugin to post the form via AJAX, along with the Recaptcha AJAX API -

https://developers.google.com/recaptcha/docs/display#recaptcha_methods

When the user submits one of the forms:

  1. intercept the submission - I used jQuery Form Plugin's beforeSubmit property
  2. destroy any existing recaptcha inputs on the page - I used jQuery's $.empty() method and Recaptcha.destroy()
  3. call Recaptcha.create() to create a recaptcha field for the specific form
  4. return false.

Then, they can fill out the recaptcha and re-submit the form. If they decide to submit a different form instead, well, your code checks for existing recaptchas so you'll only have one recaptcha on the page at a time.

Check if inputs are empty using jQuery

A clean CSS-only solution this would be:

input[type="radio"]:read-only {
        pointer-events: none;
}

What does functools.wraps do?

this is the source code about wraps:

WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__doc__')

WRAPPER_UPDATES = ('__dict__',)

def update_wrapper(wrapper,
                   wrapped,
                   assigned = WRAPPER_ASSIGNMENTS,
                   updated = WRAPPER_UPDATES):

    """Update a wrapper function to look like the wrapped function

       wrapper is the function to be updated
       wrapped is the original function
       assigned is a tuple naming the attributes assigned directly
       from the wrapped function to the wrapper function (defaults to
       functools.WRAPPER_ASSIGNMENTS)
       updated is a tuple naming the attributes of the wrapper that
       are updated with the corresponding attribute from the wrapped
       function (defaults to functools.WRAPPER_UPDATES)
    """
    for attr in assigned:
        setattr(wrapper, attr, getattr(wrapped, attr))
    for attr in updated:
        getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
    # Return the wrapper so this can be used as a decorator via partial()
    return wrapper

def wraps(wrapped,
          assigned = WRAPPER_ASSIGNMENTS,
          updated = WRAPPER_UPDATES):
    """Decorator factory to apply update_wrapper() to a wrapper function

   Returns a decorator that invokes update_wrapper() with the decorated
   function as the wrapper argument and the arguments to wraps() as the
   remaining arguments. Default arguments are as for update_wrapper().
   This is a convenience function to simplify applying partial() to
   update_wrapper().
    """
    return partial(update_wrapper, wrapped=wrapped,
                   assigned=assigned, updated=updated)

Alternative to mysql_real_escape_string without connecting to DB

Well, according to the mysql_real_escape_string function reference page: "mysql_real_escape_string() calls MySQL's library function mysql_real_escape_string, which escapes the following characters: \x00, \n, \r, \, ', " and \x1a."

With that in mind, then the function given in the second link you posted should do exactly what you need:

function mres($value)
{
    $search = array("\\",  "\x00", "\n",  "\r",  "'",  '"', "\x1a");
    $replace = array("\\\\","\\0","\\n", "\\r", "\'", '\"', "\\Z");

    return str_replace($search, $replace, $value);
}

How to get resources directory path programmatically

I'm assuming the contents of src/main/resources/ is copied to WEB-INF/classes/ inside your .war at build time. If that is the case you can just do (substituting real values for the classname and the path being loaded).

URL sqlScriptUrl = MyServletContextListener.class
                       .getClassLoader().getResource("sql/script.sql");

Facebook API error 191

I was also facing the same problem when I am using the facebook authentication method. But I rectify that issue with following changes in Facebook api (Apps >> My App >> Basic).

  1. I removed the url which i have given in ===> App on Facebook (Canvas URLs)
  2. I gave site url only in ===> Website with Facebook Login option

Then i gave that AppId and App Secret in my webpage.

So by clicking on login button, It ask for access permissions then it redirect it to give url (Website with Facebook Login ).

Core dumped, but core file is not in the current directory?

In Ubuntu18.04, the most easist way to get a core file is inputing the command below to stop the apport service.

sudo service apport stop

Then rerun the application, you will get dump file in current directory.

How to use new PasswordEncoder from Spring Security

Here is the implementation of BCrypt which is working for me.

in spring-security.xml

<authentication-manager >
    <authentication-provider ref="authProvider"></authentication-provider>  
    </authentication-manager>
<beans:bean id="authProvider" class="org.springframework.security.authentication.dao.DaoAuthenticationProvider">
  <beans:property name="userDetailsService" ref="userDetailsServiceImpl" />
  <beans:property name="passwordEncoder" ref="encoder" />
</beans:bean>
<!-- For hashing and salting user passwords -->
    <beans:bean id="encoder" class="org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder"/>

In java class

PasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
String hashedPassword = passwordEncoder.encode(yourpassword);

For more detailed example of spring security Click Here

Hope this will help.

Thanks

Difference between Date(dateString) and new Date(dateString)

I know this is old but by far the easier solution is to just use

var temp = new Date("2010-08-17T12:09:36");

Java: method to get position of a match in a String?

int match_position=text.indexOf(match);

Single-threaded apartment - cannot instantiate ActiveX control

Go ahead and add [STAThread] to the main entry of your application, this indicates the COM threading model is single-threaded apartment (STA)

example:

static class Program
{
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new WebBrowser());
    }
}

adding comment in .properties files

According to the documentation of the PropertyFile task, you can append the generated properties to an existing file. You could have a properties file with just the comment line, and have the Ant task append the generated properties.

Getting values from JSON using Python

Using your code, this is how I would do it. I know an answer was chosen, just giving additional options.

data = json.loads('{"lat":444, "lon":555}')
    ret = ''
    for j in data:
        ret = ret+" "+data[j]
return ret

When you use for in this manor you get the key of the object, not the value, so you can get the value, by using the key as an index.

Div Background Image Z-Index Issue

For z-index to work, you also need to give it a position:

header {
    width: 100%;
    height: 100px;
    background: url(../img/top.png) repeat-x;
    z-index: 110;
    position: relative;
}

How to consume REST in Java

JAX-RS but you can also use regular DOM that comes with standard Java

Start HTML5 video at a particular position when loading?

On Safari Mac for an HLS source, I needed to use the loadeddata event instead of the metadata event.

z-index not working with fixed positioning

since your over div doesn't have a positioning, the z-index doesn't know where and how to position it (and with respect to what?). Just change your over div's position to relative, so there is no side effects on that div and then the under div will obey to your will.

here is your example on jsfiddle: Fiddle

edit: I see someone already mentioned this answer!

PostgreSQL IF statement

From the docs

IF boolean-expression THEN
    statements
ELSE
    statements
END IF;

So in your above example the code should look as follows:

IF select count(*) from orders > 0
THEN
  DELETE from orders
ELSE 
  INSERT INTO orders values (1,2,3);
END IF;

You were missing: END IF;

Docker compose port mapping

If you want to access redis from the host (127.0.0.1), you have to use the ports command.

redis:
  build:
    context: .
    dockerfile: Dockerfile-redis
    ports:
    - "6379:6379"

Best practices when running Node.js with port 80 (Ubuntu / Linode)

Drop root privileges after you bind to port 80 (or 443).

This allows port 80/443 to remain protected, while still preventing you from serving requests as root:

function drop_root() {
    process.setgid('nobody');
    process.setuid('nobody');
}

A full working example using the above function:

var process = require('process');
var http = require('http');
var server = http.createServer(function(req, res) {
    res.write("Success!");
    res.end();
});

server.listen(80, null, null, function() {
    console.log('User ID:',process.getuid()+', Group ID:',process.getgid());
    drop_root();
    console.log('User ID:',process.getuid()+', Group ID:',process.getgid());
});

See more details at this full reference.

Getting an element from a Set

Yes, use HashMap ... but in a specialised way: the trap I foresee in trying to use a HashMap as a pseudo-Set is the possible confusion between "actual" elements of the Map/Set, and "candidate" elements, i.e. elements used to test whether an equal element is already present. This is far from foolproof, but nudges you away from the trap:

class SelfMappingHashMap<V> extends HashMap<V, V>{
    @Override
    public String toString(){
        // otherwise you get lots of "... object1=object1, object2=object2..." stuff
        return keySet().toString();
    }

    @Override
    public V get( Object key ){
        throw new UnsupportedOperationException( "use tryToGetRealFromCandidate()");
    }

    @Override
    public V put( V key, V value ){
       // thorny issue here: if you were indavertently to `put`
       // a "candidate instance" with the element already in the `Map/Set`: 
       // these will obviously be considered equivalent 
       assert key.equals( value );
       return super.put( key, value );
    }

    public V tryToGetRealFromCandidate( V key ){
        return super.get(key);
    }
}

Then do this:

SelfMappingHashMap<SomeClass> selfMap = new SelfMappingHashMap<SomeClass>();
...
SomeClass candidate = new SomeClass();
if( selfMap.contains( candidate ) ){
    SomeClass realThing = selfMap.tryToGetRealFromCandidate( candidate );
    ...
    realThing.useInSomeWay()...
}

But... you now want the candidate to self-destruct in some way unless the programmer actually immediately puts it in the Map/Set... you'd want contains to "taint" the candidate so that any use of it unless it joins the Map makes it "anathema". Perhaps you could make SomeClass implement a new Taintable interface.

A more satisfactory solution is a GettableSet, as below. However, for this to work you have either to be in charge of the design of SomeClass in order to make all constructors non-visible (or... able and willing to design and use a wrapper class for it):

public interface NoVisibleConstructor {
    // again, this is a "nudge" technique, in the sense that there is no known method of 
    // making an interface enforce "no visible constructor" in its implementing classes 
    // - of course when Java finally implements full multiple inheritance some reflection 
    // technique might be used...
    NoVisibleConstructor addOrGetExisting( GettableSet<? extends NoVisibleConstructor> gettableSet );
};

public interface GettableSet<V extends NoVisibleConstructor> extends Set<V> {
    V getGenuineFromImpostor( V impostor ); // see below for naming
}

Implementation:

public class GettableHashSet<V extends NoVisibleConstructor> implements GettableSet<V> {
    private Map<V, V> map = new HashMap<V, V>();

    @Override
    public V getGenuineFromImpostor(V impostor ) {
        return map.get( impostor );
    }

    @Override
    public int size() {
        return map.size();
    }

    @Override
    public boolean contains(Object o) {
        return map.containsKey( o );
    }

    @Override
    public boolean add(V e) {
        assert e != null;
        V result = map.put( e,  e );
        return result != null;
    }

    @Override
    public boolean remove(Object o) {
        V result = map.remove( o );
        return result != null;
    }

    @Override
    public boolean addAll(Collection<? extends V> c) {
        // for example:
        throw new UnsupportedOperationException();
    }

    @Override
    public void clear() {
        map.clear();
    }

    // implement the other methods from Set ...
}

Your NoVisibleConstructor classes then look like this:

class SomeClass implements NoVisibleConstructor {

    private SomeClass( Object param1, Object param2 ){
        // ...
    }

    static SomeClass getOrCreate( GettableSet<SomeClass> gettableSet, Object param1, Object param2 ) {
        SomeClass candidate = new SomeClass( param1, param2 );
        if (gettableSet.contains(candidate)) {
            // obviously this then means that the candidate "fails" (or is revealed
            // to be an "impostor" if you will).  Return the existing element:
            return gettableSet.getGenuineFromImpostor(candidate);
        }
        gettableSet.add( candidate );
        return candidate;
    }

    @Override
    public NoVisibleConstructor addOrGetExisting( GettableSet<? extends NoVisibleConstructor> gettableSet ){
       // more elegant implementation-hiding: see below
    }
}

PS one technical issue with such a NoVisibleConstructor class: it may be objected that such a class is inherently final, which may be undesirable. Actually you could always add a dummy parameterless protected constructor:

protected SomeClass(){
    throw new UnsupportedOperationException();
}

... which would at least let a subclass compile. You'd then have to think about whether you need to include another getOrCreate() factory method in the subclass.

Final step is an abstract base class (NB "element" for a list, "member" for a set) like this for your set members (when possible - again, scope for using a wrapper class where the class is not under your control, or already has a base class, etc.), for maximum implementation-hiding:

public abstract class AbstractSetMember implements NoVisibleConstructor {
    @Override
    public NoVisibleConstructor
            addOrGetExisting(GettableSet<? extends NoVisibleConstructor> gettableSet) {
        AbstractSetMember member = this;
        @SuppressWarnings("unchecked") // unavoidable!
        GettableSet<AbstractSetMembers> set = (GettableSet<AbstractSetMember>) gettableSet;
        if (gettableSet.contains( member )) {
            member = set.getGenuineFromImpostor( member );
            cleanUpAfterFindingGenuine( set );
        } else {
            addNewToSet( set );
        }
        return member;
    }

    abstract public void addNewToSet(GettableSet<? extends AbstractSetMember> gettableSet );
    abstract public void cleanUpAfterFindingGenuine(GettableSet<? extends AbstractSetMember> gettableSet );
}

... usage is fairly obvious (inside your SomeClass's static factory method):

SomeClass setMember = new SomeClass( param1, param2 ).addOrGetExisting( set );

Password masking console application

Taking the top answer, as well as the suggestions from its comments, and modifying it to use SecureString instead of String, test for all control keys, and not error or write an extra "*" to the screen when the password length is 0, my solution is:

public static SecureString getPasswordFromConsole(String displayMessage) {
    SecureString pass = new SecureString();
    Console.Write(displayMessage);
    ConsoleKeyInfo key;

    do {
        key = Console.ReadKey(true);

        // Backspace Should Not Work
        if (!char.IsControl(key.KeyChar)) {
            pass.AppendChar(key.KeyChar);
            Console.Write("*");
        } else {
            if (key.Key == ConsoleKey.Backspace && pass.Length > 0) {
                pass.RemoveAt(pass.Length - 1);
                Console.Write("\b \b");
            }
        }
    }
    // Stops Receving Keys Once Enter is Pressed
    while (key.Key != ConsoleKey.Enter);
    return pass;
}

Iterating through a list to render multiple widgets in Flutter?

Basically when you hit 'return' on a function the function will stop and will not continue your iteration, so what you need to do is put it all on a list and then add it as a children of a widget

you can do something like this:

  Widget getTextWidgets(List<String> strings)
  {
    List<Widget> list = new List<Widget>();
    for(var i = 0; i < strings.length; i++){
        list.add(new Text(strings[i]));
    }
    return new Row(children: list);
  }

or even better, you can use .map() operator and do something like this:

  Widget getTextWidgets(List<String> strings)
  {
    return new Row(children: strings.map((item) => new Text(item)).toList());
  }

Why doesn't CSS ellipsis work in table cell?

Try using max-width instead of width, the table will still calculate the width automatically.

Works even in ie11 (with ie8 compatibility mode).

_x000D_
_x000D_
td.max-width-50 {_x000D_
  border: 1px solid black;_x000D_
  max-width: 50px;_x000D_
  overflow: hidden;_x000D_
  text-overflow: ellipsis;_x000D_
  white-space: nowrap;_x000D_
}
_x000D_
<table>_x000D_
  <tbody>_x000D_
    <tr>_x000D_
      <td class="max-width-50">Hello Stack Overflow</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>Hello Stack Overflow</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td>Hello Stack Overflow</td>_x000D_
    </tr>_x000D_
  </tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

jsfiddle.

Determine if an element has a CSS class with jQuery

In my case , I used the 'is' a jQuery function, I had a HTML element with different css classes added , I was looking for a specific class in the middle of these , so I used the "is" a good alternative to check a class dynamically added to an html element , which already has other css classes, it is another good alternative.

simple example :

 <!--element html-->
 <nav class="cbp-spmenu cbp-spmenu-horizontal cbp-spmenu-bottom cbp-spmenu-open" id="menu">somethings here... </nav>

 <!--jQuery "is"-->
 $('#menu').is('.cbp-spmenu-open');

advanced example :

 <!--element html-->
    <nav class="cbp-spmenu cbp-spmenu-horizontal cbp-spmenu-bottom cbp-spmenu-open" id="menu">somethings here... </nav>

   <!--jQuery "is"-->
    if($('#menu').is('.cbp-spmenu-bottom.cbp-spmenu-open')){
       $("#menu").show();
    }

How can I add an empty directory to a Git repository?

Sometimes you have to deal with bad written libraries or software, which need a "real" empty and existing directory. Putting a simple .gitignore or .keep might break them and cause a bug. The following might help in these cases, but no guarantee...

First create the needed directory:

mkdir empty

Then you add a broken symbolic link to this directory (but on any other case than the described use case above, please use a README with an explanation):

ln -s .this.directory empty/.keep

To ignore files in this directory, you can add it in your root .gitignore:

echo "/empty" >> .gitignore

To add the ignored file, use a parameter to force it:

git add -f empty/.keep

After the commit you have a broken symbolic link in your index and git creates the directory. The broken link has some advantages, since it is no regular file and points to no regular file. So it even fits to the part of the question "(that contains no files)", not by the intention but by the meaning, I guess:

find empty -type f

This commands shows an empty result, since no files are present in this directory. So most applications, which get all files in a directory usually do not see this link, at least if they do a "file exists" or a "is readable". Even some scripts will not find any files there:

$ php -r "var_export(glob('empty/.*'));"
array (
  0 => 'empty/.',
  1 => 'empty/..',
)

But I strongly recommend to use this solution only in special circumstances, a good written README in an empty directory is usually a better solution. (And I do not know if this works with a windows filesystem...)

phpinfo() - is there an easy way for seeing it?

From the CLI:

php -r 'phpinfo();'

How can I strip first and last double quotes?

Remove a determinated string from start and end from a string.

s = '""Hello World""'
s.strip('""')

> 'Hello World'

Unable to run 'adb root' on a rooted Android phone

I finally found out how to do this! Basically you need to run adb shell first and then while you're in the shell run su, which will switch the shell to run as root!

$: adb shell
$: su

The one problem I still have is that sqlite3 is not installed so the command is not recognized.

How to uninstall Apache with command line

sc delete Apache2.4

Remove service in windows

Integer division: How do you produce a double?

Cast one of the integers/both of the integer to float to force the operation to be done with floating point Math. Otherwise integer Math is always preferred. So:

1. double d = (double)5 / 20;
2. double v = (double)5 / (double) 20;
3. double v = 5 / (double) 20;

Note that casting the result won't do it. Because first division is done as per precedence rule.

double d = (double)(5 / 20); //produces 0.0

I do not think there is any problem with casting as such you are thinking about.

How do I find the data directory for a SQL Server instance?

It depends on whether default path is set for data and log files or not.

If the path is set explicitly at Properties => Database Settings => Database default locations then SQL server stores it at Software\Microsoft\MSSQLServer\MSSQLServer in DefaultData and DefaultLog values.

However, if these parameters aren't set explicitly, SQL server uses Data and Log paths of master database.

Bellow is the script that covers both cases. This is simplified version of the query that SQL Management Studio runs.

Also, note that I use xp_instance_regread instead of xp_regread, so this script will work for any instance, default or named.

declare @DefaultData nvarchar(512)
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer', N'DefaultData', @DefaultData output

declare @DefaultLog nvarchar(512)
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer', N'DefaultLog', @DefaultLog output

declare @DefaultBackup nvarchar(512)
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer', N'BackupDirectory', @DefaultBackup output

declare @MasterData nvarchar(512)
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer\Parameters', N'SqlArg0', @MasterData output
select @MasterData=substring(@MasterData, 3, 255)
select @MasterData=substring(@MasterData, 1, len(@MasterData) - charindex('\', reverse(@MasterData)))

declare @MasterLog nvarchar(512)
exec master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE', N'Software\Microsoft\MSSQLServer\MSSQLServer\Parameters', N'SqlArg2', @MasterLog output
select @MasterLog=substring(@MasterLog, 3, 255)
select @MasterLog=substring(@MasterLog, 1, len(@MasterLog) - charindex('\', reverse(@MasterLog)))

select 
    isnull(@DefaultData, @MasterData) DefaultData, 
    isnull(@DefaultLog, @MasterLog) DefaultLog,
    isnull(@DefaultBackup, @MasterLog) DefaultBackup

You can achieve the same result by using SMO. Bellow is C# sample, but you can use any other .NET language or PowerShell.

using (var connection = new SqlConnection("Data Source=.;Integrated Security=SSPI"))
{
    var serverConnection = new ServerConnection(connection);
    var server = new Server(serverConnection);
    var defaultDataPath = string.IsNullOrEmpty(server.Settings.DefaultFile) ? server.MasterDBPath : server.Settings.DefaultFile;
    var defaultLogPath = string.IsNullOrEmpty(server.Settings.DefaultLog) ? server.MasterDBLogPath : server.Settings.DefaultLog;
}

It is so much simpler in SQL Server 2012 and above, assuming you have default paths set (which is probably always a right thing to do):

select 
    InstanceDefaultDataPath = serverproperty('InstanceDefaultDataPath'),
    InstanceDefaultLogPath = serverproperty('InstanceDefaultLogPath')

-XX:MaxPermSize with or without -XX:PermSize

By playing with parameters as -XX:PermSize and -Xms you can tune the performance of - for example - the startup of your application. I haven't looked at it recently, but a few years back the default value of -Xms was something like 32MB (I think), if your application required a lot more than that it would trigger a number of cycles of fill memory - full garbage collect - increase memory etc until it had loaded everything it needed. This cycle can be detrimental for startup performance, so immediately assigning the number required could improve startup.

A similar cycle is applied to the permanent generation. So tuning these parameters can improve startup (amongst others).

WARNING The JVM has a lot of optimization and intelligence when it comes to allocating memory, dividing eden space and older generations etc, so don't do things like making -Xms equal to -Xmx or -XX:PermSize equal to -XX:MaxPermSize as it will remove some of the optimizations the JVM can apply to its allocation strategies and therefor reduce your application performance instead of improving it.

As always: make non-trivial measurements to prove your changes actually improve performance overall (for example improving startup time could be disastrous for performance during use of the application)

Multiple try codes in one block

Extract (refactor) your statements. And use the magic of and and or to decide when to short-circuit.

def a():
    try: # a code
    except: pass # or raise
    else: return True

def b():
    try: # b code
    except: pass # or raise
    else: return True

def c():
    try: # c code
    except: pass # or raise
    else: return True

def d():
    try: # d code
    except: pass # or raise
    else: return True

def main():   
    try:
        a() and b() or c() or d()
    except:
        pass

How can I get a list of repositories 'apt-get' is checking?

All I needed was:

cd /etc/apt
nano source.list
deb http://http.kali.org/kali kali-rolling main non-free contrib
deb-src http://http.kali.org/kali kali-rolling main non-free contrib
apt upgrade && update

Source: Kali Network Repositories (/etc/apt/sources.list)

How can I create a carriage return in my C# string

Along with Environment.NewLine and the literal \r\n or just \n you may also use a verbatim string in C#. These begin with @ and can have embedded newlines. The only thing to keep in mind is that " needs to be escaped as "". An example:

string s = @"This is a string
that contains embedded new lines,
that will appear when this string is used."

How to read a value from the Windows registry

Here is some pseudo-code to retrieve the following:

  1. If a registry key exists
  2. What the default value is for that registry key
  3. What a string value is
  4. What a DWORD value is

Example code:

Include the library dependency: Advapi32.lib

HKEY hKey;
LONG lRes = RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Perl", 0, KEY_READ, &hKey);
bool bExistsAndSuccess (lRes == ERROR_SUCCESS);
bool bDoesNotExistsSpecifically (lRes == ERROR_FILE_NOT_FOUND);
std::wstring strValueOfBinDir;
std::wstring strKeyDefaultValue;
GetStringRegKey(hKey, L"BinDir", strValueOfBinDir, L"bad");
GetStringRegKey(hKey, L"", strKeyDefaultValue, L"bad");

LONG GetDWORDRegKey(HKEY hKey, const std::wstring &strValueName, DWORD &nValue, DWORD nDefaultValue)
{
    nValue = nDefaultValue;
    DWORD dwBufferSize(sizeof(DWORD));
    DWORD nResult(0);
    LONG nError = ::RegQueryValueExW(hKey,
        strValueName.c_str(),
        0,
        NULL,
        reinterpret_cast<LPBYTE>(&nResult),
        &dwBufferSize);
    if (ERROR_SUCCESS == nError)
    {
        nValue = nResult;
    }
    return nError;
}


LONG GetBoolRegKey(HKEY hKey, const std::wstring &strValueName, bool &bValue, bool bDefaultValue)
{
    DWORD nDefValue((bDefaultValue) ? 1 : 0);
    DWORD nResult(nDefValue);
    LONG nError = GetDWORDRegKey(hKey, strValueName.c_str(), nResult, nDefValue);
    if (ERROR_SUCCESS == nError)
    {
        bValue = (nResult != 0) ? true : false;
    }
    return nError;
}


LONG GetStringRegKey(HKEY hKey, const std::wstring &strValueName, std::wstring &strValue, const std::wstring &strDefaultValue)
{
    strValue = strDefaultValue;
    WCHAR szBuffer[512];
    DWORD dwBufferSize = sizeof(szBuffer);
    ULONG nError;
    nError = RegQueryValueExW(hKey, strValueName.c_str(), 0, NULL, (LPBYTE)szBuffer, &dwBufferSize);
    if (ERROR_SUCCESS == nError)
    {
        strValue = szBuffer;
    }
    return nError;
}

Is it .yaml or .yml?

After reading a bunch of people's comments online about this, my first reaction was that this is basically one of those really unimportant debates. However, my initial interest was to find out the right format so I could be consistent with my file naming practice.

Long story short, the creator of YAML are saying .yaml, but personally I keep doing .yml. That just makes more sense to me. So I went on the journey to find affirmation and soon enough, I realise that docker uses .yml everywhere. I've been writing docker-compose.yml files all this time, while you keep seeing in kubernetes' docs kubectl apply -f *.yaml...

So, in conclusion, both formats are obviously accepted and if you are on the other end, (ie: writing systems that receive a YAML file as input) you should allow for both. That seems like another snake case versus camel case thingy...

How to access the php.ini from my CPanel?

I had the same issue in cPanel 92.0.3 and it was solved through this solution:

In cPanel go to the below directory

software --> select PHP version--> option--> upload_max_filesize 

Then choose the optional size to upload your files.

Cannot find firefox binary in PATH. Make sure firefox is installed. OS appears to be: VISTA

I was also facing the same problem and I spent more than a week to fix it. Restarting my machine seemed to have fixed it, but only temporarily.

There was a solution to increase the maximum number of ephemeral ports by editing the registry file. That seemed to have fixed the problem but that also, only temporarily.

For sometime, I kept thinking if I was trying to access a driver which is no longer available, so I have tried to call:

driver.quit()

And then recreate the browser instance, which only gave me: SessionNotFoundException.

I now realized that I had used BOTH System.setProperty as well as ffCapability.setCapability to set the path of the binary.

I then tried with only System.setProperty => No luck there.

Only ffCapability.setCapability => Voila!!! So far it has been working fine. Hopefully it will work great when I try to re-run my scripts tomorrow and the day after and the day after... :)

Bottomline: Use only this

ffCapability.setCapability("binary", "C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe"); //for windows`

Hope it helps!

Laravel Migration Error: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

If you don't have any data assigned already to you database do the following:

  1. Go to app/Providers/AppServiceProvide.php and add

use Illuminate\Support\ServiceProvider;

and inside of the method boot();

Schema::defaultStringLength(191);

  1. Now delete the records in your database, user table for ex.

  2. run the following

php artisan config:cache

php artisan migrate

Why use #ifndef CLASS_H and #define CLASS_H in .h file but not in .cpp?

its because of Headerfiles define what the class contains (Members, data-structures) and cpp files implement it.

And of course, the main reason for this is that you could include one .h File multiple times in other .h files, but this would result in multiple definitions of a class, which is invalid.

How do you save/store objects in SharedPreferences on Android?

Here's a take on using Kotlin Delegated Properties that I picked up from here, but expanded on and allows for a simple mechanism for getting/setting SharedPreference properties.

For String, Int, Long, Float or Boolean, it uses the standard SharePreference getter(s) and setter(s). However, for all other data classes, it uses GSON to serialize to a String, for the setter. Then deserializes to the data object, for the getter.

Similar to other solutions, this requires adding GSON as a dependency in your gradle file:

implementation 'com.google.code.gson:gson:2.8.6'

Here's an example of a simple data class that we would want to be able to save and store to SharedPreferences:

data class User(val first: String, val last: String)

Here is the one class that implements the property delegates:

object UserPreferenceProperty : PreferenceProperty<User>(
    key = "USER_OBJECT",
    defaultValue = User(first = "Jane", last = "Doe"),
    clazz = User::class.java)

object NullableUserPreferenceProperty : NullablePreferenceProperty<User?, User>(
    key = "NULLABLE_USER_OBJECT",
    defaultValue = null,
    clazz = User::class.java)

object FirstTimeUser : PreferenceProperty<Boolean>(
        key = "FIRST_TIME_USER",
        defaultValue = false,
        clazz = Boolean::class.java
)

sealed class PreferenceProperty<T : Any>(key: String,
                                         defaultValue: T,
                                         clazz: Class<T>) : NullablePreferenceProperty<T, T>(key, defaultValue, clazz)

@Suppress("UNCHECKED_CAST")
sealed class NullablePreferenceProperty<T : Any?, U : Any>(private val key: String,
                                                           private val defaultValue: T,
                                                           private val clazz: Class<U>) : ReadWriteProperty<Any, T> {

    override fun getValue(thisRef: Any, property: KProperty<*>): T = HandstandApplication.appContext().getPreferences()
            .run {
                when {
                    clazz.isAssignableFrom(String::class.java) -> getString(key, defaultValue as String?) as T
                    clazz.isAssignableFrom(Int::class.java) -> getInt(key, defaultValue as Int) as T
                    clazz.isAssignableFrom(Long::class.java) -> getLong(key, defaultValue as Long) as T
                    clazz.isAssignableFrom(Float::class.java) -> getFloat(key, defaultValue as Float) as T
                    clazz.isAssignableFrom(Boolean::class.java) -> getBoolean(key, defaultValue as Boolean) as T
                    else -> getObject(key, defaultValue, clazz)
                }
            }

    override fun setValue(thisRef: Any, property: KProperty<*>, value: T) = HandstandApplication.appContext().getPreferences()
            .edit()
            .apply {
                when {
                    clazz.isAssignableFrom(String::class.java) -> putString(key, value as String?) as T
                    clazz.isAssignableFrom(Int::class.java) -> putInt(key, value as Int) as T
                    clazz.isAssignableFrom(Long::class.java) -> putLong(key, value as Long) as T
                    clazz.isAssignableFrom(Float::class.java) -> putFloat(key, value as Float) as T
                    clazz.isAssignableFrom(Boolean::class.java) -> putBoolean(key, value as Boolean) as T
                    else -> putObject(key, value)
                }
            }
            .apply()

    private fun Context.getPreferences(): SharedPreferences = getSharedPreferences(APP_PREF_NAME, Context.MODE_PRIVATE)

    private fun <T, U> SharedPreferences.getObject(key: String, defValue: T, clazz: Class<U>): T =
            Gson().fromJson(getString(key, null), clazz) as T ?: defValue

    private fun <T> SharedPreferences.Editor.putObject(key: String, value: T) = putString(key, Gson().toJson(value))

    companion object {
        private const val APP_PREF_NAME = "APP_PREF"
    }
}

Note: you shouldn't need to update anything in the sealed class. The delegated properties are the Object/Singletons UserPreferenceProperty, NullableUserPreferenceProperty and FirstTimeUser.

To setup a new data object for saving/getting from SharedPreferences, it's now as easy as adding four lines:

object NewPreferenceProperty : PreferenceProperty<String>(
        key = "NEW_PROPERTY",
        defaultValue = "",
        clazz = String::class.java)

Finally, you can read/write values to SharedPreferences by just using the by keyword:

private var user: User by UserPreferenceProperty
private var nullableUser: User? by NullableUserPreferenceProperty
private var isFirstTimeUser: Boolean by 

Log.d("TAG", user) // outputs the `defaultValue` for User the first time
user = User(first = "John", last = "Doe") // saves this User to the Shared Preferences
Log.d("TAG", user) // outputs the newly retrieved User (John Doe) from Shared Preferences

Better way to sort array in descending order

Use LINQ OrderByDescending method. It returns IOrderedIEnumerable<int>, which you can convert back to Array if you need so. Generally, List<>s are more functional then Arrays.

array = array.OrderByDescending(c => c).ToArray();

Is there a command like "watch" or "inotifywait" on the Mac?

I ended up doing this for macOS. I'm sure this is terrible in many ways:

#!/bin/sh
# watchAndRun
if [ $# -ne 2 ]; then
    echo "Use like this:"
    echo "   $0 filename-to-watch command-to-run"
    exit 1
fi
if which fswatch >/dev/null; then
    echo "Watching $1 and will run $2"
    while true; do fswatch --one-event $1 >/dev/null && $2; done
else
    echo "You might need to run: brew install fswatch"
fi

How can I put a database under git (version control)?

Check out Refactoring Databases (http://databaserefactoring.com/) for a bunch of good techniques for maintaining your database in tandem with code changes.

Suffice to say that you're asking the wrong questions. Instead of putting your database into git you should be decomposing your changes into small verifiable steps so that you can migrate/rollback schema changes with ease.

If you want to have full recoverability you should consider archiving your postgres WAL logs and use the PITR (point in time recovery) to play back/forward transactions to specific known good states.

Using "margin: 0 auto;" in Internet Explorer 8

Add <!doctype html> at the top of your HTML output.

Put quotes around a variable string in JavaScript

You can add these single quotes with template literals:

_x000D_
_x000D_
var text = "http://example.com"_x000D_
var quoteText = `'${text}'`_x000D_
_x000D_
console.log(quoteText)
_x000D_
_x000D_
_x000D_

Docs are here. Browsers that support template literals listed here.

How can I set the 'backend' in matplotlib in Python?

The errors you posted are unrelated. The first one is due to you selecting a backend that is not meant for interactive use, i.e. agg. You can still use (and should use) those for the generation of plots in scripts that don't require user interaction.

If you want an interactive lab-environment, as in Matlab/Pylab, you'd obviously import a backend supporting gui usage, such as Qt4Agg (needs Qt and AGG), GTKAgg (GTK an AGG) or WXAgg (wxWidgets and Agg).

I'd start by trying to use WXAgg, apart from that it really depends on how you installed Python and matplotlib (source, package etc.)

Is it possible to break a long line to multiple lines in Python?

As far as I know, it can be done. Python has implicit line continuation (inside parentheses, brackets, and strings) for triple-quoted strings ("""like this""")and the indentation of continuation lines is not important. For more info, you may want to read this article on lexical analysis, from python.org.

How to get base64 encoded data from html image

You can also use the FileReader class :

    var reader = new FileReader();
    reader.onload = function (e) {
        var data = this.result;
    }
    reader.readAsDataURL( file );

How are booleans formatted in Strings in Python?

>>> print "%r, %r" % (True, False)
True, False

This is not specific to boolean values - %r calls the __repr__ method on the argument. %s (for str) should also work.

How to empty a redis database?

tldr: flushdb clears one database and flushall clears all databases

Clear CURRENT

Delete default or currently selected database (usually `0) with

redis-cli flushdb

Clear SPECIFIC

Delete specific redis database with (e.g. 8 as my target database):

redis-cli -n 8 flushdb 

Clear ALL

Delete all redis databases with

redis-cli flushall

How to solve Object reference not set to an instance of an object.?

You need to initialize the list first:

protected List<string> list = new List<string>();

HttpClient 4.0.1 - how to release connection?

Highly recommend using a handler to handle the response.

client.execute(yourRequest,defaultHanler);

It will release the connection automatically with consume(HTTPENTITY) method.

A handler example:

private ResponseHandler<String> defaultHandler = new ResponseHandler<String>() {
    @Override
    public String handleResponse(HttpResponse response)
        throws IOException {
        int status = response.getStatusLine().getStatusCode();

        if (status >= 200 && status < 300) {
            HttpEntity entity = response.getEntity();
            return entity != null ? EntityUtils.toString(entity) : null;
        } else {
            throw new ClientProtocolException("Unexpected response status: " + status);
        }
    }
};

Error when creating a new text file with python?

If the file does not exists, open(name,'r+') will fail.

You can use open(name, 'w'), which creates the file if the file does not exist, but it will truncate the existing file.

Alternatively, you can use open(name, 'a'); this will create the file if the file does not exist, but will not truncate the existing file.

IE11 prevents ActiveX from running

In my IE11, works normally. Version: 11.306.10586.0

We can test if ActiveX works at IE, in this site: http://www.pcpitstop.com/testax.asp

How much data / information can we save / store in a QR code?

See this table.

A 101x101 QR code, with high level error correction, can hold 3248 bits, or 406 bytes. Probably not enough for any meaningful SVG/XML data.

A 177x177 grid, depending on desired level of error correction, can store between 1273 and 2953 bytes. Maybe enough to store something small.

enter image description here

NoClassDefFoundError while trying to run my jar with java.exe -jar...what's wrong?

if you use external libraries in your program and you try to pack all together in a jar file it's not that simple, because of classpath issues etc.

I'd prefer to use OneJar for this issue.

How to implement class constants?

For me none of earlier answer works. I did need to convert my static class to enum. Like this:

export enum MyConstants {
  MyFirstConstant = 'MyFirstConstant',
  MySecondConstant = 'MySecondConstant'
}

Then in my component I add new property as suggested in other answers

export class MyComponent {
public MY_CONTANTS = MyConstans;
constructor() { }
}

Then in my component's template I use it this way

<div [myDirective]="MY_CONTANTS.MyFirstConstant"> </div>

EDIT: Sorry. My problem was different than OP's. I still leave this here if someelse have same problem than I.

javascript regex for special characters

What's the difference?

/[a-zA-Z0-9]/ is a character class which matches one character that is inside the class. It consists of three ranges.

/a-zA-Z0-9/ does mean the literal sequence of those 9 characters.

Which chars from .!@#$%^&*()_+-= are needed to be escaped?

Inside a character class, only the minus (if not at the end) and the circumflex (if at the beginning). Outside of a charclass, .$^*+() have a special meaning and need to be escaped to match literally.

allows only the a-zA-Z0-9 characters and .!@#$%^&*()_+-=

Put them in a character class then, let them repeat and require to match the whole string with them by anchors:

var regex = /^[a-zA-Z0-9!@#$%\^&*)(+=._-]*$/

SQL Query for Selecting Multiple Records

I strongly recommend using lowercase field|column names, it will make your life easier.

Let's assume you have a table called users with the following definition and records:

id|firstname|lastname|username             |password
1 |joe      |doe     |[email protected]   |1234
2 |jane     |doe     |[email protected]  |12345
3 |johnny   |doe     |[email protected]|123456

let's say you want to get all records from table users, then you do:

SELECT * FROM users;

Now let's assume you want to select all records from table users, but you're interested only in the fields id, firstname and lastname, thus ignoring username and password:

SELECT id, firstname, lastname FROM users;

Now we get at the point where you want to retrieve records based on condition(s), what you need to do is to add the WHERE clause, let's say we want to select from users only those that have username = [email protected] and password = 1234, what you do is:

SELECT * FROM users
WHERE ( ( username = '[email protected]' ) AND ( password = '1234' ) );

But what if you need only the id of a record with username = [email protected] and password = 1234? then you do:

SELECT id FROM users
WHERE ( ( username = '[email protected]' ) AND ( password = '1234' ) );

Now to get to your question, as others before me answered you can use the IN clause:

SELECT * FROM users
WHERE ( id IN (1,2,..,n) );

or, if you wish to limit to a list of records between id 20 and id 40, then you can easily write:

SELECT * FROM users
WHERE ( ( id >= 20 ) AND ( id <= 40 ) );

I hope this gives a better understanding.

Getting the absolute path of the executable, using C#?

var dir = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

I jumped in for the top rated answer and found myself not getting what I expected. I had to read the comments to find what I was looking for.

For that reason I am posting the answer listed in the comments to give it the exposure it deserves.

Data access object (DAO) in Java

DAO (Data Access Object) is a very used design pattern in enterprise applications. It basically is the module that is used to access data from every source (DBMS, XML and so on). I suggest you to read some examples, like this one:

DAO Example

Please note that there are different ways to implements the original DAO Pattern, and there are many frameworks that can simplify your work. For example, the ORM (Object Relational Mapping) frameworks like iBatis or Hibernate, are used to map the result of SQL queries to java objects.

Hope it helps, Bye!

Most efficient way to reverse a numpy array

Expanding on what others have said I will give a short example.

If you have a 1D array ...

>>> import numpy as np
>>> x = np.arange(4) # array([0, 1, 2, 3])
>>> x[::-1] # returns a view
Out[1]: 
array([3, 2, 1, 0])

But if you are working with a 2D array ...

>>> x = np.arange(10).reshape(2, 5)
>>> x
Out[2]:
array([[0, 1, 2, 3, 4],
       [5, 6, 7, 8, 9]])

>>> x[::-1] # returns a view:
Out[3]: array([[5, 6, 7, 8, 9],
               [0, 1, 2, 3, 4]])

This does not actually reverse the Matrix.

Should use np.flip to actually reverse the elements

>>> np.flip(x)
Out[4]: array([[9, 8, 7, 6, 5],
               [4, 3, 2, 1, 0]])

If you want to print the elements of a matrix one-by-one use flat along with flip

>>> for el in np.flip(x).flat:
>>>     print(el, end = ' ')
9 8 7 6 5 4 3 2 1 0

TypeScript error TS1005: ';' expected (II)

I had today a similar error message. What was peculiar is that it did not break the Application. It was running smoothly but the command prompt (Windows machine) indicated there was an error. I did not update the Typescript version but found another culprit. It turned there was a tiny omission of symbol - closing ")", which I believe The Typescript is compensating for. Just for reference the code is the following:

[new Object('First Characteristic','Second Characteristic',
'Third Characteristic'*] 

* notice here the ending ")" is missing.

Once brought back no more issues on the command prompt!

How to make the tab character 4 spaces instead of 8 spaces in nano?

For anyone who may stumble across this old question ...

There is one thing that I think needs to be addressed.

~/.nanorc is used to apply your user specific settings to nano, so if you are editing files that require the use of sudo nano for permissions then this is not going to work.

When using sudo your custom user configuration files will not be loaded when opening a program, as you are not running the program from your account so none of your configuration changes in ~/.nanorc will be applied.

If this is the situation you find yourself in (wanting to run sudo nano and use your own config settings) then you have three options :

  • using command line flags when running sudo nano
  • editing the /root/.nanorc file
  • editing the /etc/nanorc global config file

Keep in mind that /etc/nanorc is a global configuration file and as such it affects all users, which may or may not be a problem depending on whether you have a multi-user system.

Also, user config files will override the global one, so if you were to edit /etc/nanorc and ~/.nanorc with different settings, when you run nano it will load the settings from ~/.nanorc but if you run sudo nano then it will load the settings from /etc/nanorc.

Same goes for /root/.nanorc this will override /etc/nanorc when running sudo nano

Using flags is probably the best option unless you have a lot of options.

How to make the 'cut' command treat same sequental delimiters as one?

This Perl one-liner shows how closely Perl is related to awk:

perl -lane 'print $F[3]' text.txt

However, the @F autosplit array starts at index $F[0] while awk fields start with $1

Get current location of user in Android without using GPS or internet

What you are looking to do is get the position using the LocationManager.NETWORK_PROVIDER instead of LocationManager.GPS_PROVIDER. The NETWORK_PROVIDER will resolve on the GSM or wifi, which ever available. Obviously with wifi off, GSM will be used. Keep in mind that using the cell network is accurate to basically 500m.

http://developer.android.com/guide/topics/location/obtaining-user-location.html has some really great information and sample code.

After you get done with most of the code in OnCreate(), add this:

// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
    public void onLocationChanged(Location location) {
      // Called when a new location is found by the network location provider.
      makeUseOfNewLocation(location);
    }

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

    public void onProviderEnabled(String provider) {}

    public void onProviderDisabled(String provider) {}
  };

// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);

You could also have your activity implement the LocationListener class and thus implement onLocationChanged() in your activity.

How to use jQuery to show/hide divs based on radio button selection?

The simple jquery source for the same -

$("input:radio[name='group1']").click(function() {      
    $('.desc').hide();
    $('#' + $("input:radio[name='group1']:checked").val()).show();
});

In order to make it little more appropriate just add checked to first option --

<div><label><input type="radio" name="group1" value="opt1" checked>opt1</label></div>  

remove .desc class from styling and modify divs like --

<div id="opt1" class="desc">lorem ipsum dolor</div>
<div id="opt2" class="desc" style="display: none;">consectetur adipisicing</div>
<div id="opt3" class="desc" style="display: none;">sed do eiusmod tempor</div>

it will really look good any-ways.

getting the difference between date in days in java

Use JodaTime for this. It is much better than the standard Java DateTime Apis. Here is the code in JodaTime for calculating difference in days:

private static void dateDiff() {

    System.out.println("Calculate difference between two dates");
    System.out.println("=================================================================");

    DateTime startDate = new DateTime(2000, 1, 19, 0, 0, 0, 0);
    DateTime endDate = new DateTime();

    Days d = Days.daysBetween(startDate, endDate);
    int days = d.getDays();

    System.out.println("  Difference between " + endDate);
    System.out.println("  and " + startDate + " is " + days + " days.");

  }

MATLAB - multiple return values from a function?

I think Octave only return one value which is the first return value, in your case, 'array'.

And Octave print it as "ans".

Others, 'listp','freep' were not printed.

Because it showed up within the function.

Try this out:

[ A, B, C] = initialize( 4 )

And the 'array','listp','freep' will print as A, B and C.

How to extract text from an existing docx file using python-docx

Without Installing python-docx

docx is basically is a zip file with several folders and files within it. In the link below you can find a simple function to extract the text from docx file, without the need to rely on python-docx and lxml the latter being sometimes hard to install:

http://etienned.github.io/posts/extract-text-from-word-docx-simply/

JavaScript style.display="none" or jQuery .hide() is more efficient?

Talking about efficiency:

document.getElementById( 'elemtId' ).style.display = 'none';

What jQuery does with its .show() and .hide() methods is, that it remembers the last state of an element. That can come in handy sometimes, but since you asked about efficiency that doesn't matter here.

Add new item in existing array in c#.net

Very old question, but still wanted to add this.

If you're looking for a one-liner, you can use the code below. It combines the list constructor that accepts an enumerable and the "new" (since question raised) initializer syntax.

myArray = new List<string>(myArray) { "add this" }.ToArray();

POST data in JSON format

Not sure if you want jQuery.

var form;

form.onsubmit = function (e) {
  // stop the regular form submission
  e.preventDefault();

  // collect the form data while iterating over the inputs
  var data = {};
  for (var i = 0, ii = form.length; i < ii; ++i) {
    var input = form[i];
    if (input.name) {
      data[input.name] = input.value;
    }
  }

  // construct an HTTP request
  var xhr = new XMLHttpRequest();
  xhr.open(form.method, form.action, true);
  xhr.setRequestHeader('Content-Type', 'application/json; charset=UTF-8');

  // send the collected data as JSON
  xhr.send(JSON.stringify(data));

  xhr.onloadend = function () {
    // done
  };
};

WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for 'jquery'. Please add a ScriptResourceMapping named jquery(case-sensitive)

The problem occurred due to the Control validator. Just Add the J Query reference to your web page as follows and then add the Validation Settings in your web.config file to overcome the problem. I too faced the same problem and the below gave the solution to my problem.

Step1:

Code to be added in web page

Step2 :

Code to be added in Web.config file

It will resolve your problem.

Creating an index on a table variable

If Table variable has large data, then instead of table variable(@table) create temp table (#table).table variable doesn't allow to create index after insert.

 CREATE TABLE #Table(C1 int,       
  C2 NVarchar(100) , C3 varchar(100)
  UNIQUE CLUSTERED (c1) 
 ); 
  1. Create table with unique clustered index

  2. Insert data into Temp "#Table" table

  3. Create non clustered indexes.

     CREATE NONCLUSTERED INDEX IX1  ON #Table (C2,C3);
    

Getting the difference between two repositories

You can add other repo first as a remote to your current repo:

git remote add other_name PATH_TO_OTHER_REPO

then fetch brach from that remote:

git fetch other_name branch_name:branch_name

this creates that branch as a new branch in your current repo, then you can diff that branch with any of your branches, for example, to compare current branch against new branch(branch_name):

git diff branch_name

Conditional Logic on Pandas DataFrame

In this specific example, where the DataFrame is only one column, you can write this elegantly as:

df['desired_output'] = df.le(2.5)

le tests whether elements are less than or equal 2.5, similarly lt for less than, gt and ge.

Ternary operator in AngularJS templates

There it is : ternary operator got added to angular parser in 1.1.5! see the changelog

Here is a fiddle showing new ternary operator used in ng-class directive.

ng-class="boolForTernary ? 'blue' : 'red'"

Full screen background image in an activity

If you want your image to show BEHIND a transparent Action Bar, put the following into your Theme's style definition:

<item name="android:windowActionBarOverlay">true</item>

Enjoy!

Assign static IP to Docker container

For docker-compose you can use following docker-compose.yml

version: '2'
services:
  nginx:
    image: nginx
    container_name: nginx-container
    networks:
      static-network:
        ipv4_address: 172.20.128.2
networks:
  static-network:
    ipam:
      config:
        - subnet: 172.20.0.0/16
          #docker-compose v3+ do not use ip_range
          ip_range: 172.28.5.0/24

from host you can test using:

docker-compose up -d
curl 172.20.128.2

Modern docker-compose does not change ip address that frequently.

To find ips of all containers in your docker-compose in a single line use:

for s in `docker-compose ps -q`; do echo ip of `docker inspect -f "{{.Name}}" $s` is `docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $s`; done

If you want to automate, you can use something like this example gist

Convert JsonObject to String

There is an inbuilt method to convert a JSONObject to a String. Why don't you use that:

JSONObject json = new JSONObject();

json.toString();

How to create dispatch queue in Swift 3

Creating a concurrent queue

let concurrentQueue = DispatchQueue(label: "queuename", attributes: .concurrent)
concurrentQueue.sync {

}  

Create a serial queue

let serialQueue = DispatchQueue(label: "queuename")
serialQueue.sync { 

}

Get main queue asynchronously

DispatchQueue.main.async {

}

Get main queue synchronously

DispatchQueue.main.sync {

}

To get one of the background thread

DispatchQueue.global(qos: .background).async {

}

Xcode 8.2 beta 2:

To get one of the background thread

DispatchQueue.global(qos: .default).async {

}

DispatchQueue.global().async {
    // qos' default value is ´DispatchQoS.QoSClass.default`
}

If you want to learn about using these queues .See this answer

How to install all required PHP extensions for Laravel?

Laravel Server Requirements mention that BCMath, Ctype, JSON, Mbstring, OpenSSL, PDO, Tokenizer, and XML extensions are required. Most of the extensions are installed and enabled by default.

You can run the following command in Ubuntu to make sure the extensions are installed.

sudo apt install openssl php-common php-curl php-json php-mbstring php-mysql php-xml php-zip

PHP version specific installation (if PHP 7.4 installed)

sudo apt install php7.4-common php7.4-bcmath openssl php7.4-json php7.4-mbstring

You may need other PHP extensions for your composer packages. Find from links below.

PHP extensions for Ubuntu 20.04 LTS (Focal Fossa)

PHP extensions for Ubuntu 18.04 LTS (Bionic)

PHP extensions for Ubuntu 16.04 LTS (Xenial)

How do I convert a list of ascii values to a string in python?

Same basic solution as others, but I personally prefer to use map instead of the list comprehension:


>>> L = [104, 101, 108, 108, 111, 44, 32, 119, 111, 114, 108, 100]
>>> ''.join(map(chr,L))
'hello, world'

How to install Guest addition in Mac OS as guest and Windows machine as host

I've the same problem, and by the "trial and error" method I have the steps to install the guest additions on a MacOS guest:

  1. insert the guest additions cd
  2. open the cd on file manager
  3. double click on VBoxDarwinAdditions.pkg
  4. the installer opens, then click contine
  5. next screen to set location of installed files, only press install
  6. your password can be asked a couple of time while installing, write it and continue
  7. this is the tricky part, on my installation, macos show an message about the driver created by oracle won't be installed because a security issue, it has the option to enable it, so click on the button to open security screen and click on the allow button next to the oracle software listed at bottom of the security settings window, it will ask your password again. Meanwhile the pkg installer continued as if it has permissions and will say "install finished", but I don't believe it so, once I unlocked the oracle drivers installations I repeat the whole process from step 3, and in the second round all installs without asking more than the first password to install.

And it is done!

Autonumber value of last inserted row - MS Access / VBA

Private Function addInsert(Media As String, pagesOut As Integer) As Long


    Set rst = db.OpenRecordset("tblenccomponent")
    With rst
        .AddNew
        !LeafletCode = LeafletCode
        !LeafletName = LeafletName
        !UNCPath = "somePath\" + LeafletCode + ".xml"
        !Media = Media
        !CustomerID = cboCustomerID.Column(0)
        !PagesIn = PagesIn
        !pagesOut = pagesOut
        addInsert = CLng(rst!enclosureID) 'ID is passed back to calling routine
        .Update
    End With
    rst.Close

End Function

The best node module for XML parsing

This answer concerns developers for Windows. You want to pick an XML parsing module that does NOT depend on node-expat. Node-expat requires node-gyp and node-gyp requires you to install Visual Studio on your machine. If your machine is a Windows Server, you definitely don't want to install Visual Studio on it.

So, which XML parsing module to pick?

Save yourself a lot of trouble and use either xml2js or xmldoc. They depend on sax.js which is a pure Javascript solution that doesn't require node-gyp.

Both libxmljs and xml-stream require node-gyp. Don't pick these unless you already have Visual Studio on your machine installed or you don't mind going down that road.

Update 2015-10-24: it seems somebody found a solution to use node-gyp on Windows without installing VS: https://github.com/nodejs/node-gyp/issues/629#issuecomment-138276692

How to insert an item into a key/value pair object?

Hashtables are not inherently sorted, your best bet is to use another structure such as a SortedList or an ArrayList

How to get to Model or Viewbag Variables in a Script Tag

What you have should work. It depends on the type of data you are setting i.e. if it's a string value you need to make sure it's in quotes e.g.

var val = '@ViewBag.ForSection';

If it's an integer you need to parse it as one i.e.

var val = parseInt(@ViewBag.ForSection);

git: updates were rejected because the remote contains work that you do not have locally

This usually happens when the repo contains some items that are not there locally. So in order to push our changes, in this case we need to integrate the remote changes and then push.

So create a pull from remote

git pull origin master

Then push changes to that remote

git push origin master

How to create a link to a directory

Symbolic or soft link (files or directories, more flexible and self documenting)

#     Source                             Link
ln -s /home/jake/doc/test/2000/something /home/jake/xxx

Hard link (files only, less flexible and not self documenting)

#   Source                             Link
ln /home/jake/doc/test/2000/something /home/jake/xxx

More information: man ln


/home/jake/xxx is like a new directory. To avoid "is not a directory: No such file or directory" error, as @trlkly comment, use relative path in the target, that is, using the example:

  1. cd /home/jake/
  2. ln -s /home/jake/doc/test/2000/something xxx

How to gracefully handle the SIGKILL signal in Java

There are ways to handle your own signals in certain JVMs -- see this article about the HotSpot JVM for example.

By using the Sun internal sun.misc.Signal.handle(Signal, SignalHandler) method call you are also able to register a signal handler, but probably not for signals like INT or TERM as they are used by the JVM.

To be able to handle any signal you would have to jump out of the JVM and into Operating System territory.

What I generally do to (for instance) detect abnormal termination is to launch my JVM inside a Perl script, but have the script wait for the JVM using the waitpid system call.

I am then informed whenever the JVM exits, and why it exited, and can take the necessary action.

How to load CSS Asynchronously

The trick to triggering an asynchronous stylesheet download is to use a <link> element and set an invalid value for the media attribute (I'm using media="none", but any value will do). When a media query evaluates to false, the browser will still download the stylesheet, but it won't wait for the content to be available before rendering the page.

<link rel="stylesheet" href="css.css" media="none">

Once the stylesheet has finished downloading the media attribute must be set to a valid value so the style rules will be applied to the document. The onload event is used to switch the media property to all:

<link rel="stylesheet" href="css.css" media="none" onload="if(media!='all')media='all'">

This method of loading CSS will deliver useable content to visitors much quicker than the standard approach. Critical CSS can still be served with the usual blocking approach (or you can inline it for ultimate performance) and non-critical styles can be progressively downloaded and applied later in the parsing / rendering process.

This technique uses JavaScript, but you can cater for non-JavaScript browsers by wrapping the equivalent blocking <link> elements in a <noscript> element:

<link rel="stylesheet" href="css.css" media="none" onload="if(media!='all')media='all'"><noscript><link rel="stylesheet" href="css.css"></noscript>

You can see the operation in www.itcha.edu.sv

enter image description here

Source in http://keithclark.co.uk/

Lock down Microsoft Excel macro

Generate a protected application for Mac or Windows from your Excel spreadsheet using OfficeProtect with either AppProtect or QuickLicense/AddLicense. There is a demonstation video called "Protect Excel Spreedsheet" at www.excelsoftware.com/videos.

Charts for Android

To make reading of this page more valuable (for future search results) I made a list of libraries known to me.. As @CommonsWare mentioned there are super-similar questions/answers.. Anyway some libraries that can be used for making charts are:

Open Source:

Paid:

** - means I didn't try those so I can't really recommend it but other users suggested it..

Full Screen Theme for AppCompat

It should be parent="@style/Theme.AppCompat.Light.NoActionBar"

<style name="Theme.AppCompat.Light.NoActionBar.FullScreen" 
parent="@style/Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>
</style>

jQuery remove options from select

find() takes a selector, not a value. This means you need to use it in the same way you would use the regular jQuery function ($('selector')).

Therefore you need to do something like this:

$(this).find('[value="X"]').remove();

See the jQuery find docs.

What's the difference between the atomic and nonatomic attributes?

After reading so many articles, Stack Overflow posts and making demo applications to check variable property attributes, I decided to put all the attributes information together:

  1. atomic // Default
  2. nonatomic
  3. strong = retain // Default
  4. weak = unsafe_unretained
  5. retain
  6. assign // Default
  7. unsafe_unretained
  8. copy
  9. readonly
  10. readwrite // Default

In the article Variable property attributes or modifiers in iOS you can find all the above-mentioned attributes, and that will definitely help you.

  1. atomic

    • atomic means only one thread access the variable (static type).
    • atomic is thread safe.
    • But it is slow in performance
    • atomic is the default behavior
    • Atomic accessors in a non garbage collected environment (i.e. when using retain/release/autorelease) will use a lock to ensure that another thread doesn't interfere with the correct setting/getting of the value.
    • It is not actually a keyword.

    Example:

        @property (retain) NSString *name;
    
        @synthesize name;
    
  2. nonatomic

    • nonatomic means multiple thread access the variable (dynamic type).
    • nonatomic is thread-unsafe.
    • But it is fast in performance
    • nonatomic is NOT default behavior. We need to add the nonatomic keyword in the property attribute.
    • It may result in unexpected behavior, when two different process (threads) access the same variable at the same time.

    Example:

        @property (nonatomic, retain) NSString *name;
    
        @synthesize name;
    

Creating a select box with a search option

Use a data list instead.

<form action="/action_page.php" method="get">
      <input list="browsers" name="browser">
      <datalist id="browsers">
        <option value="Internet Explorer">
        <option value="Firefox">
        <option value="Chrome">
        <option value="Opera">
        <option value="Safari">
      </datalist>
      <input type="submit">
    </form>

Not supported I.E. 9 and back. https://www.w3schools.com/tags/tryit.asp?filename=tryhtml5_datalist

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

For random hash values, some engineers said golden ratio prime number(2654435761) is a bad choice, with my testing results, I found that it's not true; instead, 2654435761 distributes the hash values pretty good.

#define MCR_HashTableSize 2^10

unsigned int
Hash_UInt_GRPrimeNumber(unsigned int key)
{
  key = key*2654435761 & (MCR_HashTableSize - 1)
  return key;
}

The hash table size must be a power of two.

I have written a test program to evaluate many hash functions for integers, the results show that GRPrimeNumber is a pretty good choice.

I have tried:

  1. total_data_entry_number / total_bucket_number = 2, 3, 4; where total_bucket_number = hash table size;
  2. map hash value domain into bucket index domain; that is, convert hash value into bucket index by Logical And Operation with (hash_table_size - 1), as shown in Hash_UInt_GRPrimeNumber();
  3. calculate the collision number of each bucket;
  4. record the bucket that has not been mapped, that is, an empty bucket;
  5. find out the max collision number of all buckets; that is, the longest chain length;

With my testing results, I found that Golden Ratio Prime Number always has the fewer empty buckets or zero empty bucket and the shortest collision chain length.

Some hash functions for integers are claimed to be good, but the testing results show that when the total_data_entry / total_bucket_number = 3, the longest chain length is bigger than 10(max collision number > 10), and many buckets are not mapped(empty buckets), which is very bad, compared with the result of zero empty bucket and longest chain length 3 by Golden Ratio Prime Number Hashing.

BTW, with my testing results, I found one version of shifting-xor hash functions is pretty good(It's shared by mikera).

unsigned int Hash_UInt_M3(unsigned int key)
{
  key ^= (key << 13);
  key ^= (key >> 17);    
  key ^= (key << 5); 
  return key;
}

Android Google Maps API V2 Zoom to Current Location

try this code :

private GoogleMap mMap;


LocationManager locationManager;


private static final String TAG = "";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    // Obtain the SupportMapFragment and get notified when the map is ready to be used.
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(map);
    mapFragment.getMapAsync(this);

    arrayPoints = new ArrayList<LatLng>();
}

@Override
public void onMapReady(GoogleMap googleMap) {


    mMap = googleMap;


    mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);


    LatLng myPosition;


    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    googleMap.setMyLocationEnabled(true);
    LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    String provider = locationManager.getBestProvider(criteria, true);
    Location location = locationManager.getLastKnownLocation(provider);


    if (location != null) {
        double latitude = location.getLatitude();
        double longitude = location.getLongitude();
        LatLng latLng = new LatLng(latitude, longitude);
        myPosition = new LatLng(latitude, longitude);


        LatLng coordinate = new LatLng(latitude, longitude);
        CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(coordinate, 19);
        mMap.animateCamera(yourLocation);
    }
}

}

Dont forget to add permissions on AndroidManifest.xml.

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

How to find substring from string?

Example using std::string find method:

#include <iostream>
#include <string>

int main (){
    std::string str ("There are two needles in this haystack with needles.");
    std::string str2 ("needle");

    size_t found = str.find(str2);
    if(found!=std::string::npos){ 
        std::cout << "first 'needle' found at: " << found << '\n';
    }

    return 0;
}

Result:

first 'needle' found at: 14.

"int cannot be dereferenced" in Java

Assuming getItemNumber() returns an int, replace

if (id.equals(list[pos].getItemNumber()))

with

if (id == list[pos].getItemNumber())

What is an optional value in Swift?

Let's take the example of an NSError, if there isn't an error being returned you'd want to make it optional to return Nil. There's no point in assigning a value to it if there isn't an error..

var error: NSError? = nil

This also allows you to have a default value. So you can set a method a default value if the function isn't passed anything

func doesntEnterNumber(x: Int? = 5) -> Bool {
    if (x == 5){
        return true
    } else {
        return false
    }
}

integrating barcode scanner into php application?

If you have Bluetooth, Use twedge on windows and getblue app on android, they also have a few videos of it. It's made by TEC-IT. I've got it to work by setting the interface option to bluetooth server in TWedge and setting the output setting in getblue to Bluetooth client and selecting my computer from the Bluetooth devices list. Make sure your computer and phone is paired. Also to get the barcode as input set the action setting in TWedge to Keyboard Wedge. This will allow for you to first click the input text box on said form, then scan said product with your phone and wait a sec for the barcode number to be put into the text box. Using this method requires no php that doesn't already exist in your current form processing, just process the text box as usual and viola your phone scans bar codes, sends them to your pc via Bluetooth wirelessly, your computer inserts the barcode into whatever text field is selected in any application or website. Hope this helps.

Make anchor link go some pixels above where it's linked to

I had this same issue, and there's a really quick and simple solution without CSS of JS. Just create a separate unstyled div with an ID like "aboutMeAnchor and just place it well above the section you actually want to land on.

Change name of folder when cloning from GitHub?

In case you want to clone a specific branch only, then,

git clone -b <branch-name> <repo-url> <destination-folder-name>

for example,

git clone -b dev https://github.com/sferik/sign-in-with-twitter.git signin

SQL LEFT-JOIN on 2 fields for MySQL

select a.ip, a.os, a.hostname, a.port, a.protocol,
       b.state
from a
left join b on a.ip = b.ip 
           and a.port = b.port

Using colors with printf

This is a small program to get different color on terminal.

#include <stdio.h>

#define KNRM  "\x1B[0m"
#define KRED  "\x1B[31m"
#define KGRN  "\x1B[32m"
#define KYEL  "\x1B[33m"
#define KBLU  "\x1B[34m"
#define KMAG  "\x1B[35m"
#define KCYN  "\x1B[36m"
#define KWHT  "\x1B[37m"

int main()
{
    printf("%sred\n", KRED);
    printf("%sgreen\n", KGRN);
    printf("%syellow\n", KYEL);
    printf("%sblue\n", KBLU);
    printf("%smagenta\n", KMAG);
    printf("%scyan\n", KCYN);
    printf("%swhite\n", KWHT);
    printf("%snormal\n", KNRM);

    return 0;
}

Javascript "Not a Constructor" Exception while creating objects

Sometimes it is just how you export and import it. For this error message it could be, that the default keyword is missing.

export default SampleClass {}

Where you instantiate it:

import SampleClass from 'path/to/class';
let sampleClass = new SampleClass();

Option 2, with curly braces:

export SampleClass {}
import { SampleClass } from 'path/to/class';
let sampleClass = new SampleClass();

Unable to install packages in latest version of RStudio and R Version.3.1.1

Please check the following to be able to install new packages:

1- In Tools -> Global Options -> Packages, uncheck the "Use Internet Explorer library/proxy for HTTP" option,

2- In Tools -> Global Options -> Packages, change the CRAN mirror to "0- Cloud - Rstudio, automatic redirection to servers worldwide"

3- Restart Rstudio.

4- Have fun!

How to get parameter on Angular2 route in Angular way?

As of Angular 6+, this is handled slightly differently than in previous versions. As @BeetleJuice mentions in the answer above, paramMap is new interface for getting route params, but the execution is a bit different in more recent versions of Angular. Assuming this is in a component:

private _entityId: number;

constructor(private _route: ActivatedRoute) {
    // ...
}

ngOnInit() {
    // For a static snapshot of the route...
    this._entityId = this._route.snapshot.paramMap.get('id');

    // For subscribing to the observable paramMap...
    this._route.paramMap.pipe(
        switchMap((params: ParamMap) => this._entityId = params.get('id'))
    );

    // Or as an alternative, with slightly different execution...
    this._route.paramMap.subscribe((params: ParamMap) =>  {
        this._entityId = params.get('id');
    });
}

I prefer to use both because then on direct page load I can get the ID param, and also if navigating between related entities the subscription will update properly.

Source in Angular Docs

How can I use Bash syntax in Makefile targets?

If portability is important you may not want to depend on a specific shell in your Makefile. Not all environments have bash available.

How to print number with commas as thousands separators?

Here is the locale grouping code after removing irrelevant parts and cleaning it up a little:

(The following only works for integers)

def group(number):
    s = '%d' % number
    groups = []
    while s and s[-1].isdigit():
        groups.append(s[-3:])
        s = s[:-3]
    return s + ','.join(reversed(groups))

>>> group(-23432432434.34)
'-23,432,432,434'

There are already some good answers in here. I just want to add this for future reference. In python 2.7 there is going to be a format specifier for thousands separator. According to python docs it works like this

>>> '{:20,.2f}'.format(f)
'18,446,744,073,709,551,616.00'

In python3.1 you can do the same thing like this:

>>> format(1234567, ',d')
'1,234,567'

MySQL COUNT DISTINCT

Overall

SELECT
       COUNT(DISTINCT `site_id`) as distinct_sites
  FROM `cp_visits`
 WHERE ts >= DATE_SUB(NOW(), INTERVAL 1 DAY)

Or per site

  SELECT
         `site_id` as site,
         COUNT(DISTINCT `user_id`) as distinct_users_per_site
    FROM `cp_visits`
   WHERE ts >= DATE_SUB(NOW(), INTERVAL 1 DAY)
GROUP BY `site_id`

Having the time column in the result doesn't make sense - since you are aggregating the rows, showing one particular time is irrelevant, unless it is the min or max you are after.

Reading a text file with SQL Server

Just discovered this:

SELECT * FROM OPENROWSET(BULK N'<PATH_TO_FILE>', SINGLE_CLOB) AS Contents

It'll pull in the contents of the file as varchar(max). Replace SINGLE_CLOB with:

SINGLE_NCLOB for nvarchar(max) SINGLE_BLOB for varbinary(max)

Thanks to http://www.mssqltips.com/sqlservertip/1643/using-openrowset-to-read-large-files-into-sql-server/ for this!

Descending order by date filter in AngularJs

see w3schools samples: https://www.w3schools.com/angular/angular_filters.asp https://www.w3schools.com/angular/tryit.asp?filename=try_ng_filters_orderby_click

then add the "reverse" flag:

<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<body>

<p>Click the table headers to change the sorting order:</p>

<div ng-app="myApp" ng-controller="namesCtrl">

<table border="1" width="100%">
<tr>
<th ng-click="orderByMe('name')">Name</th>
<th ng-click="orderByMe('country')">Country</th>
</tr>
<tr ng-repeat="x in names | orderBy:myOrderBy:reverse">
<td>{{x.name}}</td>
<td>{{x.country}}</td>
</tr>
</table>

</div>

<script>
angular.module('myApp', []).controller('namesCtrl', function($scope) {
    $scope.names = [
        {name:'Jani',country:'Norway'},
        {name:'Carl',country:'Sweden'},
        {name:'Margareth',country:'England'},
        {name:'Hege',country:'Norway'},
        {name:'Joe',country:'Denmark'},
        {name:'Gustav',country:'Sweden'},
        {name:'Birgit',country:'Denmark'},
        {name:'Mary',country:'England'},
        {name:'Kai',country:'Norway'}
        ];

    $scope.reverse=false;
    $scope.orderByMe = function(x) {

        if($scope.myOrderBy == x) {
            $scope.reverse=!$scope.reverse;
        }
        $scope.myOrderBy = x;
    }
});
</script>

</body>
</html>

How to remove certain characters from a string in C++?

For those of you that prefer a more concise, easier to read lambda coding style...

This example removes all non-alphanumeric and white space characters from a wide string. You can mix it up with any of the other ctype.h helper functions to remove complex-looking character-based tests.

(I'm not sure how these functions would handle CJK languages, so walk softly there.)

    // Boring C loops: 'for(int i=0;i<str.size();i++)' 
    // Boring C++ eqivalent: 'for(iterator iter=c.begin; iter != c.end; ++iter)'

See if you don't find this easier to understand than noisy C/C++ for/iterator loops:

TSTRING label = _T("1.   Replen & Move  RPMV");
TSTRING newLabel = label;
set<TCHAR> badChars; // Use ispunct, isalpha, isdigit, et.al. (lambda version, with capture list parameter(s) example; handiest thing since sliced bread)
for_each(label.begin(), label.end(), [&badChars](TCHAR n){
    if (!isalpha(n) && !isdigit(n))
        badChars.insert(n);
});

for_each(badChars.begin(), badChars.end(), [&newLabel](TCHAR n){
    newLabel.erase(std::remove(newLabel.begin(), newLabel.end(), n), newLabel.end());
});

newLabel results after running this code: "1ReplenMoveRPMV"

This is just academic, since it would clearly be more precise, concise and efficient to combine the 'if' logic from lambda0 (first for_each) into the single lambda1 (second for_each), if you have already established which characters are the "badChars".

Loop Through All Subfolders Using VBA

And to complement Rich's recursive answer, a non-recursive method.

Public Sub NonRecursiveMethod()
    Dim fso, oFolder, oSubfolder, oFile, queue As Collection

    Set fso = CreateObject("Scripting.FileSystemObject")
    Set queue = New Collection
    queue.Add fso.GetFolder("your folder path variable") 'obviously replace

    Do While queue.Count > 0
        Set oFolder = queue(1)
        queue.Remove 1 'dequeue
        '...insert any folder processing code here...
        For Each oSubfolder In oFolder.SubFolders
            queue.Add oSubfolder 'enqueue
        Next oSubfolder
        For Each oFile In oFolder.Files
            '...insert any file processing code here...
        Next oFile
    Loop

End Sub

You can use a queue for FIFO behaviour (shown above), or you can use a stack for LIFO behaviour which would process in the same order as a recursive approach (replace Set oFolder = queue(1) with Set oFolder = queue(queue.Count) and replace queue.Remove(1) with queue.Remove(queue.Count), and probably rename the variable...)

Flattening a shallow list in Python

A simple alternative is to use numpy's concatenate but it converts the contents to float:

import numpy as np
print np.concatenate([[1,2],[3],[5,89],[],[6]])
# array([  1.,   2.,   3.,   5.,  89.,   6.])
print list(np.concatenate([[1,2],[3],[5,89],[],[6]]))
# [  1.,   2.,   3.,   5.,  89.,   6.]

How do I enter a multi-line comment in Perl?

POD is the official way to do multi line comments in Perl,

From faq.perl.org[perlfaq7]

The quick-and-dirty way to comment out more than one line of Perl is to surround those lines with Pod directives. You have to put these directives at the beginning of the line and somewhere where Perl expects a new statement (so not in the middle of statements like the # comments). You end the comment with =cut, ending the Pod section:

=pod

my $object = NotGonnaHappen->new();

ignored_sub();

$wont_be_assigned = 37;

=cut

The quick-and-dirty method only works well when you don't plan to leave the commented code in the source. If a Pod parser comes along, your multiline comment is going to show up in the Pod translation. A better way hides it from Pod parsers as well.

The =begin directive can mark a section for a particular purpose. If the Pod parser doesn't want to handle it, it just ignores it. Label the comments with comment. End the comment using =end with the same label. You still need the =cut to go back to Perl code from the Pod comment:

=begin comment

my $object = NotGonnaHappen->new();

ignored_sub();

$wont_be_assigned = 37;

=end comment

=cut

How can I lock the first row and first column of a table when scrolling, possibly using JavaScript and CSS?

How about a solution where you put the actual "data" of the table inside its own div, with overflow: scroll;? Then the browser will automatically create scrollbars for the portion of the "table" you do not want to lock, and you can put the "table header"/first row just above that <div>.

Not sure how that would work with scrolling horizontally though.

php $_POST array empty upon form submission

I know this is old, but wanted to share my solution.

In my case the issue was in my .htaccess as I added variables to raise my PHP's max upload limit. My code was like this:

php_value post_max_size 50MB
php_value upload_max_filesize 50MB

Later I notice that the values should like xxM not xxMB and when I changed it to:

php_value post_max_size 50M
php_value upload_max_filesize 50M

now my $_POST returned the data as normal before. Hope this helps someone in the future.

Generate an integer that is not among four billion given ones

I came up with the following algorithm.

My idea: go through all the whole file of integers once and for every bit position count its 0s and 1s. The amount of 0s and 1s must be 2^(numOfBits)/2, therefore, if the amount is less then expected we can use it of our resulting number.

For example, suppose integer is 32 bit, then we require

int[] ones = new int[32];
int[] zeroes = new int[32];

For every number we have to iterate though 32 bits and increase value of 0 or 1:

for(int i = 0; i < 32; i++){
   ones[i] += (val>>i&0x1); 
   zeroes[i] += (val>>i&0x1)==1?0:1;
}

Finally, after the file was processed:

int res = 0;
for(int i = 0; i < 32; i++){
   if(ones[i] < (long)1<<31)res|=1<<i;
}
return res;

NOTE: in some languages (ex. Java) 1<<31 is a negative number, therefore, (long)1<<31 is the right way to do it

Git: How to rebase to a specific commit?

The comment by jsz above saved me tons of pain, so here's a step-by-step recipie based on it that I've been using to rebase/move any commit on top of any other commit:

  1. Find a previous branching point of the branch to be rebased (moved) - call it old parent. In the example above that's A
  2. Find commit on top of which you want to move the branch to - call it new parent. In the exampe that's B
  3. You need to be on your branch (the one you move):
  4. Apply your rebase: git rebase --onto <new parent> <old parent>

In the example above that's as simple as:

   git checkout topic
   git rebase --onto B A

Could not load file or assembly or one of its dependencies. Access is denied. The issue is random, but after it happens once, it continues

For me, the following hack worked; Go to IIS -> Application Pools -> Advance Settings -> Process Model -> Identity Changed from Built-in Account (ApplicationPoolIdentity) to Custom Account (My Domain User)

Using a dictionary to count the items in a list

I always thought that for a task that trivial, I wouldn't want to import anything. But i may be wrong, depending on collections.Counter being faster or not.

items = "Whats the simpliest way to add the list items to a dictionary "

stats = {}
for i in items:
    if i in stats:
        stats[i] += 1
    else:
        stats[i] = 1

# bonus
for i in sorted(stats, key=stats.get):
    print("%d×'%s'" % (stats[i], i))

I think this may be preferable to using count(), because it will only go over the iterable once, whereas count may search the entire thing on every iteration. I used this method to parse many megabytes of statistical data and it always was reasonably fast.

jQuery load first 3 elements, click "load more" to display next 5 elements

Simple and with little changes. And also hide load more when entire list is loaded.

jsFiddle here.

$(document).ready(function () {
    // Load the first 3 list items from another HTML file
    //$('#myList').load('externalList.html li:lt(3)');
    $('#myList li:lt(3)').show();
    $('#showLess').hide();
    var items =  25;
    var shown =  3;
    $('#loadMore').click(function () {
        $('#showLess').show();
        shown = $('#myList li:visible').size()+5;
        if(shown< items) {$('#myList li:lt('+shown+')').show();}
        else {$('#myList li:lt('+items+')').show();
             $('#loadMore').hide();
             }
    });
    $('#showLess').click(function () {
        $('#myList li').not(':lt(3)').hide();
    });
});

How to select rows for a specific date, ignoring time in SQL Server

select 
  * 
from sales 
where 
  dateadd(dd, datediff(dd, 0, salesDate), 0) = '11/11/2010'

What character represents a new line in a text area

By HTML specifications, browsers are required to canonicalize line breaks in user input to CR LF (\r\n), and I don’t think any browser gets this wrong. Reference: clause 17.13.4 Form content types in the HTML 4.01 spec.

In HTML5 drafts, the situation is more complicated, since they also deal with the processes inside a browser, not just the data that gets sent to a server-side form handler when the form is submitted. According to them (and browser practice), the textarea element value exists in three variants:

  1. the raw value as entered by the user, unnormalized; it may contain CR, LF, or CR LF pair;
  2. the internal value, called “API value”, where line breaks are normalized to LF (only);
  3. the submission value, where line breaks are normalized to CR LF pairs, as per Internet conventions.

How to [recursively] Zip a directory in PHP?

I've edited Alix Axel's answer to take a third argrument, when setting this third argrument to true all the files will be added under the main directory rather than directly in the zip folder.

If the zip file exists the file will be deleted as well.

Example:

Zip('/path/to/maindirectory','/path/to/compressed.zip',true);

Third argrument true zip structure:

maindirectory
--- file 1
--- file 2
--- subdirectory 1
------ file 3
------ file 4
--- subdirectory 2
------ file 5
------ file 6

Third argrument false or missing zip structure:

file 1
file 2
subdirectory 1
--- file 3
--- file 4
subdirectory 2
--- file 5
--- file 6

Edited code:

function Zip($source, $destination, $include_dir = false)
{

    if (!extension_loaded('zip') || !file_exists($source)) {
        return false;
    }

    if (file_exists($destination)) {
        unlink ($destination);
    }

    $zip = new ZipArchive();
    if (!$zip->open($destination, ZIPARCHIVE::CREATE)) {
        return false;
    }
    $source = str_replace('\\', '/', realpath($source));

    if (is_dir($source) === true)
    {

        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($source), RecursiveIteratorIterator::SELF_FIRST);

        if ($include_dir) {

            $arr = explode("/",$source);
            $maindir = $arr[count($arr)- 1];

            $source = "";
            for ($i=0; $i < count($arr) - 1; $i++) { 
                $source .= '/' . $arr[$i];
            }

            $source = substr($source, 1);

            $zip->addEmptyDir($maindir);

        }

        foreach ($files as $file)
        {
            $file = str_replace('\\', '/', $file);

            // Ignore "." and ".." folders
            if( in_array(substr($file, strrpos($file, '/')+1), array('.', '..')) )
                continue;

            $file = realpath($file);

            if (is_dir($file) === true)
            {
                $zip->addEmptyDir(str_replace($source . '/', '', $file . '/'));
            }
            else if (is_file($file) === true)
            {
                $zip->addFromString(str_replace($source . '/', '', $file), file_get_contents($file));
            }
        }
    }
    else if (is_file($source) === true)
    {
        $zip->addFromString(basename($source), file_get_contents($source));
    }

    return $zip->close();
}

Adding an img element to a div with javascript

function image()
{
    //dynamically add an image and set its attribute
    var img=document.createElement("img");
    img.src="p1.jpg"
    img.id="picture"
    var foo = document.getElementById("fooBar");
    foo.appendChild(img);
}

<span id="fooBar">&nbsp;</span>

Declaring a boolean in JavaScript using just var

Variables in Javascript don't have a type. Non-zero, non-null, non-empty and true are "true". Zero, null, undefined, empty string and false are "false".

There's a Boolean type though, as are literals true and false.

What is the difference between 'classic' and 'integrated' pipeline mode in IIS7?

In classic mode IIS works h ISAPI extensions and ISAPI filters directly. And uses two pipe lines , one for native code and other for managed code. You can simply say that in Classic mode IIS 7.x works just as IIS 6 and you dont get extra benefits out of IIS 7.x features.

In integrated mode IIS and ASP.Net are tightly coupled rather then depending on just two DLLs on Asp.net as in case of classic mode.

How can I limit ngFor repeat to some number of items in Angular?

This seems simpler to me

<li *ngFor="let item of list | slice:0:10; let i=index" class="dropdown-item" (click)="onClick(item)">{{item.text}}</li>

Closer to your approach

<ng-container *ngFor="let item of list" let-i="index">
  <li class="dropdown-item" (click)="onClick(item)" *ngIf="i<11">{{item.text}}</li>
</ng-container>

How to check if a string is a valid JSON string in JavaScript without using Try/Catch

Here my working code:

function IsJsonString(str) {
  try {
    var json = JSON.parse(str);
    return (typeof json === 'object');
  } catch (e) {
    return false;
  }
}

What is Common Gateway Interface (CGI)?

You maybe want to know what is not CGI, and the answer is a MODULE for your web server (if I suppose you are runnig Apache). AND THAT'S THE BIG DIFERENCE, because CGI needs and external program, thread, whatever to instantiate a PERL, PHP, C app server where when you run as a MODULE that program is the web server (apache) per-se.

Because of all this there is a lot of performance, security, portability issues that come into play. But it's good to know what is not CGI first, to understand what it is.

Easily measure elapsed time

The values printed by your second program are seconds, and microseconds.

0 26339 = 0.026'339 s =   26339 µs
4 45025 = 4.045'025 s = 4045025 µs

Difference in System. exit(0) , System.exit(-1), System.exit(1 ) in Java

A good gotcha is any error code > 255 will be converted to error code % 256. One should be specifically careful about this if they are using a custom error code > 255 and expecting the exact error code in the application logic. http://www.tldp.org/LDP/abs/html/exitcodes.html

Convert JavaScript String to be all lower case?

you can use the in built .toLowerCase() method on javascript strings. ex: var x = "Hello"; x.toLowerCase();

py2exe - generate single executable file

No, it's doesn't give you a single executable in the sense that you only have one file afterwards - but you have a directory which contains everything you need for running your program, including an exe file.

I just wrote this setup.py today. You only need to invoke python setup.py py2exe.

How to pass anonymous types as parameters?

I would use IEnumerable<object> as type for the argument. However not a great gain for the unavoidable explicit cast. Cheers

Environment variable to control java.io.tmpdir?

It isn't an environment variable, but still gives you control over the temp dir:

-Djava.io.tmpdir

ex.:

java -Djava.io.tmpdir=/mytempdir

IN vs ANY operator in PostgreSQL

There are two obvious points, as well as the points in the other answer:

  • They are exactly equivalent when using sub queries:

    SELECT * FROM table
    WHERE column IN(subquery);
    
    SELECT * FROM table
    WHERE column = ANY(subquery);
    

On the other hand:

  • Only the IN operator allows a simple list:

    SELECT * FROM table
    WHERE column IN(… , … , …);
    

Presuming they are exactly the same has caught me out several times when forgetting that ANY doesn’t work with lists.

Finding the source code for built-in Python functions?

2 methods,

  1. You can check usage about snippet using help()
  2. you can check hidden code for those modules using inspect

1) inspect:

use inpsect module to explore code you want... NOTE: you can able to explore code only for modules (aka) packages you have imported

for eg:

  >>> import randint  
  >>> from inspect import getsource
  >>> getsource(randint) # here i am going to explore code for package called `randint`

2) help():

you can simply use help() command to get help about builtin functions as well its code.

for eg: if you want to see the code for str() , simply type - help(str)

it will return like this,

>>> help(str)
Help on class str in module __builtin__:

class str(basestring)
 |  str(object='') -> string
 |
 |  Return a nice string representation of the object.
 |  If the argument is a string, the return value is the same object.
 |
 |  Method resolution order:
 |      str
 |      basestring
 |      object
 |
 |  Methods defined here:
 |
 |  __add__(...)
 |      x.__add__(y) <==> x+y
 |
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x
 |
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 |
 |  __format__(...)
 |      S.__format__(format_spec) -> string
 |
 |      Return a formatted version of S as described by format_spec.
 |
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 |
 |  __getattribute__(...)
-- More  --

how to get current month and year

Find Current Year Using Razor try this

@DateTime.Now.Year

How do I remove all null and empty string values from an object?

Here is the optimized code snippet to remove empty arrays/objects as well:

function removeNullsInObject(obj) {
    if( typeof obj === 'string' ){ return; }
    $.each(obj, function(key, value){
        if (value === "" || value === null){
            delete obj[key];
        } else if ($.isArray(value)) {
            if( value.length === 0 ){ delete obj[key]; return; }
            $.each(value, function (k,v) {
                removeNullsInObject(v);
            });
        } else if (typeof value === 'object') {
            if( Object.keys(value).length === 0 ){ 
                delete obj[key]; return; 
            }
            removeNullsInObject(value);
        }
    }); 
 }

Thanks @Alexis king :)

Count unique values in a column in Excel

With the Dynamic Array formulas(as of this posting only available to Office 365 Insiders):

=COUNTA(UNIQUE(A:A))

Remove last character from C++ string

str.erase(str.begin() + str.size() - 1)

str.erase(str.rbegin()) does not compile unfortunately, since reverse_iterator cannot be converted to a normal_iterator.

C++11 is your friend in this case.

Adding a stylesheet to asp.net (using Visual Studio 2010)

Several things here.

First off, you're defining your CSS in 3 places!

In line, in the head and externally. I suggest you only choose one. I'm going to suggest externally.

I suggest you update your code in your ASP form from

<td style="background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;" 
        class="style6">

to this:

<td  class="style6">

And then update your css too

.style6
    {
        height: 79px; background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;
    }

This removes the inline.

Now, to move it from the head of the webForm.

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>AR Toolbox</title>
    <link rel="Stylesheet" href="css/master.css" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<table class="style1">
    <tr>
        <td class="style6">
            <asp:Menu ID="Menu1" runat="server">
                <Items>
                    <asp:MenuItem Text="Home" Value="Home"></asp:MenuItem>
                    <asp:MenuItem Text="About" Value="About"></asp:MenuItem>
                    <asp:MenuItem Text="Compliance" Value="Compliance">
                        <asp:MenuItem Text="Item 1" Value="Item 1"></asp:MenuItem>
                        <asp:MenuItem Text="Item 2" Value="Item 2"></asp:MenuItem>
                    </asp:MenuItem>
                    <asp:MenuItem Text="Tools" Value="Tools"></asp:MenuItem>
                    <asp:MenuItem Text="Contact" Value="Contact"></asp:MenuItem>
                </Items>
            </asp:Menu>
        </td>
    </tr>
    <tr>
        <td class="style6">
            <img alt="South University'" class="style7" 
                src="file:///C:/Users/jnewnam/Documents/Visual%20Studio%202010/WebSites/WebSite1/img/suo_n_seal_hor_pantone.png" /></td>
    </tr>
    <tr>
        <td class="style2">
            <table class="style3">
                <tr>
                    <td>
                        &nbsp;</td>
                </tr>
            </table>
        </td>
    </tr>
    <tr>
        <td style="color: #FFFFFF; background-color: #A3A3A3">
            This is the footer.</td>
    </tr>
</table>
</form>
</body>
</html>

Now, in a new file called master.css (in your css folder) add

ul {
list-style-type:none;
margin:0;
padding:0;
}

li {
display:inline;
padding:20px;
}
.style1
{
    width: 100%;
}
.style2
{
    height: 459px;
}
.style3
{
    width: 100%;
    height: 100%;
}
.style6
{
    height: 79px; background-color: #A3A3A3; color: #FFFFFF; font-family: 'Arial Black'; font-size: large; font-weight: bold;
}
.style7
{
    width: 345px;
    height: 73px;
}

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

i had created new repo in github and i had the same problem, but it also had problem while pulling, so this worked for me.

but this is not advised in repos that already have many codes as this could mess up everything

git push origin master --force

copy all files and folders from one drive to another drive using DOS (command prompt)

Use robocopy. Robocopy is shipped by default on Windows Vista and newer, and is considered the replacement for xcopy. (xcopy has some significant limitations, including the fact that it can't handle paths longer than 256 characters, even if the filesystem can).

robocopy c:\ d:\ /e /zb /copyall /purge /dcopy:dat

Note that using /purge on the root directory of the volume will cause Robocopy to apply the requested operation on files inside the System Volume Information directory. Run robocopy /? for help. Also note that you probably want to open the command prompt as an administrator to be able to copy system files. To speed things up, use /b instead of /zb.

jQuery Event Keypress: Which key was pressed?

I have just made a plugin for jQuery that allows easier keypress events. Instead of having to find the number and put it in, all you have to do is this:

How to use it

  1. Include the code I have below
  2. Run this code:
$(document).keydown(function(e) {
    if (getPressedKey(e) == theKeyYouWantToFireAPressEventFor /*Add 'e.ctrlKey here to only fire if the combo is CTRL+theKeyYouWantToFireAPressEventFor'*/) {
        // Your Code To Fire When You Press theKeyYouWantToFireAPressEventFor 
    }
});

It's that simple. Please note that theKeyYouWantToFireAPressEventFor is not a number, but a string (e.g "a" to fire when A is pressed, "ctrl" to fire when CTRL (control) is pressed, or, in the case of a number, just 1, no quotes. That would fire when 1 is pressed.)

The Example/Code:

_x000D_
_x000D_
function getPressedKey(e){var a,s=e.keyCode||e.which,c=65,r=66,o=67,l=68,t=69,f=70,n=71,d=72,i=73,p=74,u=75,h=76,m=77,w=78,k=79,g=80,b=81,v=82,q=83,y=84,j=85,x=86,z=87,C=88,K=89,P=90,A=32,B=17,D=8,E=13,F=16,G=18,H=19,I=20,J=27,L=33,M=34,N=35,O=36,Q=37,R=38,S=40,T=45,U=46,V=91,W=92,X=93,Y=48,Z=49,$=50,_=51,ea=52,aa=53,sa=54,ca=55,ra=56,oa=57,la=96,ta=97,fa=98,na=99,da=100,ia=101,pa=102,ua=103,ha=104,ma=105,wa=106,ka=107,ga=109,ba=110,va=111,qa=112,ya=113,ja=114,xa=115,za=116,Ca=117,Ka=118,Pa=119,Aa=120,Ba=121,Da=122,Ea=123,Fa=114,Ga=145,Ha=186,Ia=187,Ja=188,La=189,Ma=190,Na=191,Oa=192,Qa=219,Ra=220,Sa=221,Ta=222;return s==Fa&&(a="numlock"),s==Ga&&(a="scrolllock"),s==Ha&&(a="semicolon"),s==Ia&&(a="equals"),s==Ja&&(a="comma"),s==La&&(a="dash"),s==Ma&&(a="period"),s==Na&&(a="slash"),s==Oa&&(a="grave"),s==Qa&&(a="openbracket"),s==Ra&&(a="backslash"),s==Sa&&(a="closebracket"),s==Ta&&(a="singlequote"),s==B&&(a="ctrl"),s==D&&(a="backspace"),s==E&&(a="enter"),s==F&&(a="shift"),s==G&&(a="alt"),s==H&&(a="pause"),s==I&&(a="caps"),s==J&&(a="esc"),s==L&&(a="pageup"),s==M&&(a="padedown"),s==N&&(a="end"),s==O&&(a="home"),s==Q&&(a="leftarrow"),s==R&&(a="uparrow"),s==S&&(a="downarrow"),s==T&&(a="insert"),s==U&&(a="delete"),s==V&&(a="winleft"),s==W&&(a="winright"),s==X&&(a="select"),s==Z&&(a=1),s==$&&(a=2),s==_&&(a=3),s==ea&&(a=4),s==aa&&(a=5),s==sa&&(a=6),s==ca&&(a=7),s==ra&&(a=8),s==oa&&(a=9),s==Y&&(a=0),s==ta&&(a=1),s==fa&&(a=2),s==na&&(a=3),s==da&&(a=4),s==ia&&(a=5),s==pa&&(a=6),s==ua&&(a=7),s==ha&&(a=8),s==ma&&(a=9),s==la&&(a=0),s==wa&&(a="times"),s==ka&&(a="add"),s==ga&&(a="minus"),s==ba&&(a="decimal"),s==va&&(a="devide"),s==qa&&(a="f1"),s==ya&&(a="f2"),s==ja&&(a="f3"),s==xa&&(a="f4"),s==za&&(a="f5"),s==Ca&&(a="f6"),s==Ka&&(a="f7"),s==Pa&&(a="f8"),s==Aa&&(a="f9"),s==Ba&&(a="f10"),s==Da&&(a="f11"),s==Ea&&(a="f12"),s==c&&(a="a"),s==r&&(a="b"),s==o&&(a="c"),s==l&&(a="d"),s==t&&(a="e"),s==f&&(a="f"),s==n&&(a="g"),s==d&&(a="h"),s==i&&(a="i"),s==p&&(a="j"),s==u&&(a="k"),s==h&&(a="l"),s==m&&(a="m"),s==w&&(a="n"),s==k&&(a="o"),s==g&&(a="p"),s==b&&(a="q"),s==v&&(a="r"),s==q&&(a="s"),s==y&&(a="t"),s==j&&(a="u"),s==x&&(a="v"),s==z&&(a="w"),s==C&&(a="x"),s==K&&(a="y"),s==P&&(a="z"),s==A&&(a="space"),a}_x000D_
_x000D_
$(document).keydown(function(e) {_x000D_
  $("#key").text(getPressedKey(e));_x000D_
  console.log(getPressedKey(e));_x000D_
  if (getPressedKey(e)=="space") {_x000D_
    e.preventDefault();_x000D_
  }_x000D_
  if (getPressedKey(e)=="backspace") {_x000D_
    e.preventDefault();_x000D_
  }_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<p>The Pressed Key: <span id=key></span></p>
_x000D_
_x000D_
_x000D_

Because the long version is so... well... long, I have made a PasteBin link for it:
http://pastebin.com/VUaDevz1

Spring Boot Remove Whitelabel Error Page

Spring Boot by default has a “whitelabel” error page which you can see in a browser if you encounter a server error. Whitelabel Error Page is a generic Spring Boot error page which is displayed when no custom error page is found.

Set “server.error.whitelabel.enabled=false” to switch of the default error page

Python: Assign Value if None Exists

This is a very different style of programming, but I always try to rewrite things that looked like

bar = None
if foo():
    bar = "Baz"

if bar is None:
    bar = "Quux"

into just:

if foo():
    bar = "Baz"
else:
    bar = "Quux"

That is to say, I try hard to avoid a situation where some code paths define variables but others don't. In my code, there is never a path which causes an ambiguity of the set of defined variables (In fact, I usually take it a step further and make sure that the types are the same regardless of code path). It may just be a matter of personal taste, but I find this pattern, though a little less obvious when I'm writing it, much easier to understand when I'm later reading it.

How to implement endless list with RecyclerView?

For me, it's very simple:

     private boolean mLoading = false;

     mList.setOnScrollListener(new RecyclerView.OnScrollListener() {

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);

            int totalItem = mLinearLayoutManager.getItemCount();
            int lastVisibleItem = mLinearLayoutManager.findLastVisibleItemPosition();

            if (!mLoading && lastVisibleItem == totalItem - 1) {
                mLoading = true;
                // Scrolled to bottom. Do something here.
                mLoading = false;
            }
        }
    });

Be careful with asynchronous jobs: mLoading must be changed at the end of the asynchronous jobs. Hope it will be helpful!

How do I implement __getattribute__ without an infinite recursion error?

How is the __getattribute__ method used?

It is called before the normal dotted lookup. If it raises AttributeError, then we call __getattr__.

Use of this method is rather rare. There are only two definitions in the standard library:

$ grep -Erl  "def __getattribute__\(self" cpython/Lib | grep -v "/test/"
cpython/Lib/_threading_local.py
cpython/Lib/importlib/util.py

Best Practice

The proper way to programmatically control access to a single attribute is with property. Class D should be written as follows (with the setter and deleter optionally to replicate apparent intended behavior):

class D(object):
    def __init__(self):
        self.test2=21

    @property
    def test(self):
        return 0.

    @test.setter
    def test(self, value):
        '''dummy function to avoid AttributeError on setting property'''

    @test.deleter
    def test(self):
        '''dummy function to avoid AttributeError on deleting property'''

And usage:

>>> o = D()
>>> o.test
0.0
>>> o.test = 'foo'
>>> o.test
0.0
>>> del o.test
>>> o.test
0.0

A property is a data descriptor, thus it is the first thing looked for in the normal dotted lookup algorithm.

Options for __getattribute__

You several options if you absolutely need to implement lookup for every attribute via __getattribute__.

  • raise AttributeError, causing __getattr__ to be called (if implemented)
  • return something from it by
    • using super to call the parent (probably object's) implementation
    • calling __getattr__
    • implementing your own dotted lookup algorithm somehow

For example:

class NoisyAttributes(object):
    def __init__(self):
        self.test=20
        self.test2=21
    def __getattribute__(self, name):
        print('getting: ' + name)
        try:
            return super(NoisyAttributes, self).__getattribute__(name)
        except AttributeError:
            print('oh no, AttributeError caught and reraising')
            raise
    def __getattr__(self, name):
        """Called if __getattribute__ raises AttributeError"""
        return 'close but no ' + name    


>>> n = NoisyAttributes()
>>> nfoo = n.foo
getting: foo
oh no, AttributeError caught and reraising
>>> nfoo
'close but no foo'
>>> n.test
getting: test
20

What you originally wanted.

And this example shows how you might do what you originally wanted:

class D(object):
    def __init__(self):
        self.test=20
        self.test2=21
    def __getattribute__(self,name):
        if name=='test':
            return 0.
        else:
            return super(D, self).__getattribute__(name)

And will behave like this:

>>> o = D()
>>> o.test = 'foo'
>>> o.test
0.0
>>> del o.test
>>> o.test
0.0
>>> del o.test

Traceback (most recent call last):
  File "<pyshell#216>", line 1, in <module>
    del o.test
AttributeError: test

Code review

Your code with comments. You have a dotted lookup on self in __getattribute__. This is why you get a recursion error. You could check if name is "__dict__" and use super to workaround, but that doesn't cover __slots__. I'll leave that as an exercise to the reader.

class D(object):
    def __init__(self):
        self.test=20
        self.test2=21
    def __getattribute__(self,name):
        if name=='test':
            return 0.
        else:      #   v--- Dotted lookup on self in __getattribute__
            return self.__dict__[name]

>>> print D().test
0.0
>>> print D().test2
...
RuntimeError: maximum recursion depth exceeded in cmp

Facebook Oauth Logout

For Python developers that want to log user out straight from the backend

At the moment I'm writing this, the trick with m.facebook.com no longer works (at least for me) and user is redirected to the mobile FB login page which obviously is not good for UX.

Fortunately, FB PHP SDK has a semi-documented solution (in case the link doesn't lead to getLogoutUrl() function, just search look for it on that page). This is also mentioned in at least one other on StackOverflow: Facebook php SDK getLogoutUrl() problem.

BTW I've just noticed that Zach Greenberg got it right in this question, but I'm adding my answer as a summary for Python developers.

Rendering partial view on button click in ASP.NET MVC

So here is the controller code.

public IActionResult AddURLTest()
{
    return ViewComponent("AddURL");
}

You can load it using JQuery load method.

$(document).ready (function(){
    $("#LoadSignIn").click(function(){
        $('#UserControl').load("/Home/AddURLTest");
    });
});

source code link

syntax error when using command line in python

Running from the command line means running from the terminal or DOS shell. You are running it from Python itself.

How to check python anaconda version installed on Windows 10 PC?

On the anaconda prompt, do a

  • conda -V or conda --version to get the conda version.
  • python -V or python --version to get the python version.
  • conda list anaconda$ to get the Anaconda version.
  • conda list to get the Name, Version, Build & Channel details of all the packages installed (in the current environment).
  • conda info to get all the current environment details.
  • conda info --envs To see a list of all your environments

Detailed description here, download cheat sheet from here

What does "The following object is masked from 'package:xxx'" mean?

I have the same problem. I avoid it with remove.packages("Package making this confusion") and it works. In my case, I don't need the second package, so that is not a very good idea.

Append values to a set in Python

The way I like to do this is to convert both the original set and the values I'd like to add into lists, add them, and then convert them back into a set, like this:

setMenu = {"Eggs", "Bacon"}
print(setMenu)
> {'Bacon', 'Eggs'}
setMenu = set(list(setMenu) + list({"Spam"}))
print(setMenu)
> {'Bacon', 'Spam', 'Eggs'}
setAdditions = {"Lobster", "Sausage"}
setMenu = set(list(setMenu) + list(setAdditions))
print(setMenu)
> {'Lobster', 'Spam', 'Eggs', 'Sausage', 'Bacon'}

This way I can also easily add multiple sets using the same logic, which gets me an TypeError: unhashable type: 'set' if I try doing it with the .update() method.

Find multiple files and rename them in Linux

small script i wrote to replace all files with .txt extension to .cpp extension under /tmp and sub directories recursively

#!/bin/bash

for file in $(find /tmp -name '*.txt')
do
  mv $file $(echo "$file" | sed -r 's|.txt|.cpp|g')
done

Access all Environment properties as a Map or Properties object

For Spring Boot, the accepted answer will overwrite duplicate properties with lower priority ones. This solution will collect the properties into a SortedMap and take only the highest priority duplicate properties.

final SortedMap<String, String> sortedMap = new TreeMap<>();
for (final PropertySource<?> propertySource : env.getPropertySources()) {
    if (!(propertySource instanceof EnumerablePropertySource))
        continue;
    for (final String name : ((EnumerablePropertySource<?>) propertySource).getPropertyNames())
        sortedMap.computeIfAbsent(name, propertySource::getProperty);
}

Is there a simple, elegant way to define singletons?

My simple solution which is based on the default value of function parameters.

def getSystemContext(contextObjList=[]):
    if len( contextObjList ) == 0:
        contextObjList.append( Context() )
        pass
    return contextObjList[0]

class Context(object):
    # Anything you want here

JavaScript get window X/Y position for scroll

Using pure javascript you can use Window.scrollX and Window.scrollY

window.addEventListener("scroll", function(event) {
    var top = this.scrollY,
        left =this.scrollX;
}, false);

Notes

The pageXOffset property is an alias for the scrollX property, and The pageYOffset property is an alias for the scrollY property:

window.pageXOffset == window.scrollX; // always true
window.pageYOffset == window.scrollY; // always true

Here is a quick demo

_x000D_
_x000D_
window.addEventListener("scroll", function(event) {_x000D_
  _x000D_
    var top = this.scrollY,_x000D_
        left = this.scrollX;_x000D_
  _x000D_
    var horizontalScroll = document.querySelector(".horizontalScroll"),_x000D_
        verticalScroll = document.querySelector(".verticalScroll");_x000D_
    _x000D_
    horizontalScroll.innerHTML = "Scroll X: " + left + "px";_x000D_
      verticalScroll.innerHTML = "Scroll Y: " + top + "px";_x000D_
  _x000D_
}, false);
_x000D_
*{box-sizing: border-box}_x000D_
:root{height: 200vh;width: 200vw}_x000D_
.wrapper{_x000D_
    position: fixed;_x000D_
    top:20px;_x000D_
    left:0px;_x000D_
    width:320px;_x000D_
    background: black;_x000D_
    color: green;_x000D_
    height: 64px;_x000D_
}_x000D_
.wrapper div{_x000D_
    display: inline;_x000D_
    width: 50%;_x000D_
    float: left;_x000D_
    text-align: center;_x000D_
    line-height: 64px_x000D_
}_x000D_
.horizontalScroll{color: orange}
_x000D_
<div class=wrapper>_x000D_
    <div class=horizontalScroll>Scroll (x,y) to </div>_x000D_
    <div class=verticalScroll>see me in action</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Calculate age given the birth date in the format YYYYMMDD

here is a simple way of calculating age:

//dob date dd/mm/yy 
var d = 01/01/1990


//today
//date today string format 
var today = new Date(); // i.e wed 04 may 2016 15:12:09 GMT
//todays year
var todayYear = today.getFullYear();
// today month
var todayMonth = today.getMonth();
//today date
var todayDate = today.getDate();

//dob
//dob parsed as date format   
var dob = new Date(d);
// dob year
var dobYear = dob.getFullYear();
// dob month
var dobMonth = dob.getMonth();
//dob date
var dobDate = dob.getDate();

var yearsDiff = todayYear - dobYear ;
var age;

if ( todayMonth < dobMonth ) 
 { 
  age = yearsDiff - 1; 
 }
else if ( todayMonth > dobMonth ) 
 {
  age = yearsDiff ; 
 }

else //if today month = dob month
 { if ( todayDate < dobDate ) 
  {
   age = yearsDiff - 1;
  }
    else 
    {
     age = yearsDiff;
    }
 }

Rownum in postgresql

If you have a unique key, you may use COUNT(*) OVER ( ORDER BY unique_key ) as ROWNUM

SELECT t.*, count(*) OVER (ORDER BY k ) ROWNUM 
FROM yourtable t;

| k |     n | rownum |
|---|-------|--------|
| a | TEST1 |      1 |
| b | TEST2 |      2 |
| c | TEST2 |      3 |
| d | TEST4 |      4 |

DEMO

What's the difference between 'int?' and 'int' in C#?

int? is shorthand for Nullable<int>.

This may be the post you were looking for.

Differences in boolean operators: & vs && and | vs ||

Maybe it can be useful to know that the bitwise AND and bitwise OR operators are always evaluated before conditional AND and conditional OR used in the same expression.

if ( (1>2) && (2>1) | true) // false!

Is there an Eclipse plugin to run system shell in the Console?

Simply create a new external tool configuration (from Eclipse Run -> External Tools)

for example - To open Cygwin terminal on the current resource directory:

Location:

C:\cygwin\bin\mintty.exe

Working Directory:

${container_loc}

Arguments:

-i /Cygwin-Terminal.ico  
-"cygpath -p '${container_loc}' | xargs cd"

Difference between Visual Basic 6.0 and VBA

Here's a more technical and thorough answer to an old question: Visual Basic for Applications (VBA) and Visual Basic (pre-.NET) are not just similar languages, they are the same language. Specifically:

  • They have the same specification: The implementation-independent description of what the language contains and what it means. You can read it here: [MS-VBAL]: VBA Language Specification
  • They have the same platform: They both compile to Microsoft P-Code, which is in turn executed by the exact same virtual machine, which is implemented in the dll msvbvm[x.0].dll.

In an old VB reference book I came across last year, the author (Paul Lomax) even asserted that 'VBA' has always been the name of the language itself, whether used in stand-alone applications or in embedded contexts (such as MS Office):

"Before we go any further, let's just clarify on fundamental point. Visual Basic for Applications (VBA) is the language used to program in Visual Basic (VB). VB itself is a development environment; the language element of that environment is VBA."

The minor differences

Hosted vs. stand-alone: In practical, terms, when most people say "VBA" they specifically mean "VBA when used in MS Office", and they say "VB6" to mean "VBA used in the last version of the standalone VBA compiler (i.e. Visual Studio 6)". The IDE and compiler bundled with MS Office is almost identical to Visual Studio 6, with the limitation that it does not allow compilation to stand-alone dll or exe files. This in turns means that classes defined in embedded VBA projects are not accessible from non-embedded COM consumers, because they cannot be registered.

Continued development: Microsoft stopped producing a stand-alone VBA compiler with Visual Studio 6, as they switched to the .NET runtime as the platform of choice. However, the MS Office team continues to maintain VBA, and even released a new version (VBA7) with a new VM (now just called VBA7.dll) starting with MS Office 2010. The only major difference is that VBA7 has both a 32- and 64-bit version and has a few enhancements to handle the differences between the two, specifically with regards to external API invocations.

Python: How to check a string for substrings from a list?

Try this test:

any(substring in string for substring in substring_list)

It will return True if any of the substrings in substring_list is contained in string.

Note that there is a Python analogue of Marc Gravell's answer in the linked question:

from itertools import imap
any(imap(string.__contains__, substring_list)) 

In Python 3, you can use map directly instead:

any(map(string.__contains__, substring_list))

Probably the above version using a generator expression is more clear though.

Document directory path of Xcode Device Simulator

iOS 11

if let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory,
                                                           .userDomainMask,
                                                           true).first {
    debugPrint("documentsPath = \(documentsPath)")
}

What is exactly the base pointer and stack pointer? To what do they point?

Long time since I've done Assembly programming, but this link might be useful...

The processor has a collection of registers which are used to store data. Some of these are direct values while others are pointing to an area within RAM. Registers do tend to be used for certain specific actions and every operand in assembly will require a certain amount of data in specific registers.

The stack pointer is mostly used when you're calling other procedures. With modern compilers, a bunch of data will be dumped first on the stack, followed by the return address so the system will know where to return once it's told to return. The stack pointer will point at the next location where new data can be pushed to the stack, where it will stay until it's popped back again.

Base registers or segment registers just point to the address space of a large amount of data. Combined with a second regiser, the Base pointer will divide the memory in huge blocks while the second register will point at an item within this block. Base pointers therefor point to the base of blocks of data.

Do keep in mind that Assembly is very CPU specific. The page I've linked to provides information about different types of CPU's.

How to remove new line characters from a string?

string remove = Regex.Replace(txtsp.Value).ToUpper(), @"\t|\n|\r", "");

Git: Recover deleted (remote) branch

It may seem as being too cautious, but I frequently zip a copy of whatever I've been working on before I make source control changes. In a Gitlab project I'm working on, I recently deleted a remote branch by mistake that I wanted to keep after merging a merge request. It turns out all I had to do to get it back with the commit history was push again. The merge request was still tracked by Gitlab, so it still shows the blue 'merged' label to the right of the branch. I still zipped my local folder in case something bad happened.

Compile error: "g++: error trying to exec 'cc1plus': execvp: No such file or directory"

I had the same issue with gcc "gnat1" and it was due to the path being wrong. Gnat1 was on version 4.6 but I was executing version 4.8.1, which I had installed. As a temporary solution, I copied gnat1 from 4.6 and pasted under the 4.8.1 folder.

The path to gcc on my computer is /usr/lib/gcc/i686-linux-gnu/

You can find the path by using the find command:

find /usr -name "gnat1"

In your case you would look for cc1plus:

find /usr -name "cc1plus"

Of course, this is a quick solution and a more solid answer would be fixing the broken path.

Enable IIS7 gzip

I only needed to add the feature in windows features as Charlie mentioned.For people who cannot find it on window 10 or server 2012+ find it as below. I struggled a bit

Windows 10

enter image description here

windows server 2012 R2

enter image description here

window server 2016

enter image description here

How to convert integers to characters in C?

In C, int, char, long, etc. are all integers.

They typically have different memory sizes and thus different ranges as in INT_MIN to INT_MAX. char and arrays of char are often used to store characters and strings. Integers are stored in many types: int being the most popular for a balance of speed, size and range.

ASCII is by far the most popular character encoding, but others exist. The ASCII code for an 'A' is 65, 'a' is 97, '\n' is 10, etc. ASCII data is most often stored in a char variable. If the C environment is using ASCII encoding, the following all store the same value into the integer variable.

int i1 = 'a';
int i2 = 97;
char c1 = 'a';
char c2 = 97;

To convert an int to a char, simple assign:

int i3 = 'b';
int i4 = i3;
char c3;
char c4;
c3 = i3;
// To avoid a potential compiler warning, use a cast `char`.
c4 = (char) i4; 

This warning comes up because int typically has a greater range than char and so some loss-of-information may occur. By using the cast (char), the potential loss of info is explicitly directed.

To print the value of an integer:

printf("<%c>\n", c3); // prints <b>

// Printing a `char` as an integer is less common but do-able
printf("<%d>\n", c3); // prints <98>

// Printing an `int` as a character is less common but do-able.
// The value is converted to an `unsigned char` and then printed.
printf("<%c>\n", i3); // prints <b>

printf("<%d>\n", i3); // prints <98>

There are additional issues about printing such as using %hhu or casting when printing an unsigned char, but leave that for later. There is a lot to printf().

best way to get the key of a key/value javascript object

A one liner for you:

const OBJECT = {
    'key1': 'value1',
    'key2': 'value2',
    'key3': 'value3',
    'key4': 'value4'
};

const value = 'value2';

const key = Object.keys(OBJECT)[Object.values(OBJECT).indexOf(value)];

window.console.log(key); // = key2

Uploading/Displaying Images in MVC 4

        <input type="file" id="picfile" name="picf" />
       <input type="text" id="txtName" style="width: 144px;" />
 $("#btncatsave").click(function () {
var Name = $("#txtName").val();
var formData = new FormData();
var totalFiles = document.getElementById("picfile").files.length;

                    var file = document.getElementById("picfile").files[0];
                    formData.append("FileUpload", file);
                    formData.append("Name", Name);

$.ajax({
                    type: "POST",
                    url: '/Category_Subcategory/Save_Category',
                    data: formData,
                    dataType: 'json',
                    contentType: false,
                    processData: false,
                    success: function (msg) {

                                 alert(msg);

                    },
                    error: function (error) {
                        alert("errror");
                    }
                });

});

 [HttpPost]
    public ActionResult Save_Category()
    {
      string Name=Request.Form[1]; 
      if (Request.Files.Count > 0)
        {
            HttpPostedFileBase file = Request.Files[0];
         }


    }

link_to method and click event in Rails

To follow up on Ron's answer if using JQuery and putting it in application.js or the head section you need to wrap it in a ready() section...

$(document).ready(function() {
  $('#my-link').click(function(event){
    alert('Hooray!');
    event.preventDefault(); // Prevent link from following its href
  });
});

How to get the Power of some Integer in Swift language?

Or just :

var a:Int = 3
var b:Int = 3
println(pow(Double(a),Double(b)))

Simple JavaScript Checkbox Validation

Another Simple way is to create & invoke the function validate() when the form loads & when submit button is clicked. By using checked property we check whether the checkbox is selected or not. cbox[0] has an index 0 which is used to access the first value (i.e Male) with name="gender"

You can do the following:

_x000D_
_x000D_
function validate() {_x000D_
  var cbox = document.forms["myForm"]["gender"];_x000D_
  if (_x000D_
    cbox[0].checked == false &&_x000D_
    cbox[1].checked == false &&_x000D_
    cbox[2].checked == false_x000D_
  ) {_x000D_
    alert("Please Select Gender");_x000D_
    return false;_x000D_
  } else {_x000D_
    alert("Successfully Submited");_x000D_
    return true;_x000D_
  }_x000D_
}
_x000D_
<form onload="return validate()" name="myForm">_x000D_
  <input type="checkbox" name="gender" value="male"> Male_x000D_
_x000D_
  <input type="checkbox" name="gender" value="female"> Female_x000D_
_x000D_
  <input type="checkbox" name="gender" value="other"> Other <br>_x000D_
_x000D_
  <input type="submit" name="submit" value="Submit" onclick="validate()">_x000D_
</form>
_x000D_
_x000D_
_x000D_

Demo: CodePen

convert xml to java object using jaxb (unmarshal)

Tests

On the Tests class we will add an @XmlRootElement annotation. Doing this will let your JAXB implementation know that when a document starts with this element that it should instantiate this class. JAXB is configuration by exception, this means you only need to add annotations where your mapping differs from the default. Since the testData property differs from the default mapping we will use the @XmlElement annotation. You may find the following tutorial helpful: http://wiki.eclipse.org/EclipseLink/Examples/MOXy/GettingStarted

package forum11221136;

import javax.xml.bind.annotation.*;

@XmlRootElement
public class Tests {

    TestData testData;

    @XmlElement(name="test-data")
    public TestData getTestData() {
        return testData;
    }

    public void setTestData(TestData testData) {
        this.testData = testData;
    }

}

TestData

On this class I used the @XmlType annotation to specify the order in which the elements should be ordered in. I added a testData property that appeared to be missing. I also used an @XmlElement annotation for the same reason as in the Tests class.

package forum11221136;

import java.util.List;
import javax.xml.bind.annotation.*;

@XmlType(propOrder={"title", "book", "count", "testData"})
public class TestData {
    String title;
    String book;
    String count;
    List<TestData> testData;

    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getBook() {
        return book;
    }
    public void setBook(String book) {
        this.book = book;
    }
    public String getCount() {
        return count;
    }
    public void setCount(String count) {
        this.count = count;
    }
    @XmlElement(name="test-data")
    public List<TestData> getTestData() {
        return testData;
    }
    public void setTestData(List<TestData> testData) {
        this.testData = testData;
    }
}

Demo

Below is an example of how to use the JAXB APIs to read (unmarshal) the XML and populate your domain model and then write (marshal) the result back to XML.

package forum11221136;

import java.io.File;
import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Tests.class);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        File xml = new File("src/forum11221136/input.xml");
        Tests tests = (Tests) unmarshaller.unmarshal(xml);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(tests, System.out);
    }

}

What are the ascii values of up down left right?

There is no real ascii codes for these keys as such, you will need to check out the scan codes for these keys, known as Make and Break key codes as per helppc's information. The reason the codes sounds 'ascii' is because the key codes are handled by the old BIOS interrupt 0x16 and keyboard interrupt 0x9.

                 Normal Mode            Num lock on
                 Make    Break        Make          Break
Down arrow       E0 50   E0 D0     E0 2A E0 50   E0 D0 E0 AA
Left arrow       E0 4B   E0 CB     E0 2A E0 4B   E0 CB E0 AA
Right arrow      E0 4D   E0 CD     E0 2A E0 4D   E0 CD E0 AA
Up arrow         E0 48   E0 C8     E0 2A E0 48   E0 C8 E0 AA

Hence by looking at the codes following E0 for the Make key code, such as 0x50, 0x4B, 0x4D, 0x48 respectively, that is where the confusion arise from looking at key-codes and treating them as 'ascii'... the answer is don't as the platform varies, the OS varies, under Windows it would have virtual key code corresponding to those keys, not necessarily the same as the BIOS codes, VK_UP, VK_DOWN, VK_LEFT, VK_RIGHT.. this will be found in your C++'s header file windows.h, as I recall in the SDK's include folder.

Do not rely on the key-codes to have the same 'identical ascii' codes shown here as the Operating system will reprogram the entire BIOS code in whatever the OS sees fit, naturally that would be expected because since the BIOS code is 16bit, and the OS (nowadays are 32bit protected mode), of course those codes from the BIOS will no longer be valid.

Hence the original keyboard interrupt 0x9 and BIOS interrupt 0x16 would be wiped from the memory after the BIOS loads it and when the protected mode OS starts loading, it would overwrite that area of memory and replace it with their own 32 bit protected mode handlers to deal with those keyboard scan codes.

Here is a code sample from the old days of DOS programming, using Borland C v3:

#include <bios.h>
int getKey(void){
    int key, lo, hi;
    key = bioskey(0);
    lo = key & 0x00FF;
    hi = (key & 0xFF00) >> 8;
    return (lo == 0) ? hi + 256 : lo;
}

This routine actually, returned the codes for up, down is 328 and 336 respectively, (I do not have the code for left and right actually, this is in my old cook book!) The actual scancode is found in the lo variable. Keys other than the A-Z,0-9, had a scan code of 0 via the bioskey routine.... the reason 256 is added, because variable lo has code of 0 and the hi variable would have the scan code and adds 256 on to it in order not to confuse with the 'ascii' codes...

Android - How to decode and decompile any APK file?

To decompile APK Use APKTool.
You can learn how APKTool works on http://www.decompileandroid.com/ or by reading the documentation.

how to set length of an column in hibernate with maximum length

if your column is varchar use annotation length

@Column(length = 255)

or use another column type

@Column(columnDefinition="TEXT")

Asynchronous Requests with Python requests

I know this has been closed for a while, but I thought it might be useful to promote another async solution built on the requests library.

list_of_requests = ['http://moop.com', 'http://doop.com', ...]

from simple_requests import Requests
for response in Requests().swarm(list_of_requests):
    print response.content

The docs are here: http://pythonhosted.org/simple-requests/

Ruby value of a hash key?

How about this?

puts "ok" if hash_variable["key"] == "X"

You can access hash values with the [] operator

C++ variable has initializer but incomplete type?

You cannot define a variable of an incomplete type. You need to bring the whole definition of Cat into scope before you can create the local variable in main. I recommend that you move the definition of the type Cat to a header and include it from the translation unit that has main.

How do I change Eclipse to use spaces instead of tabs?

In Eclipse go to Window » Preferences then search for Formatter.

You will see various bold links, click on each bold link and set it to use spaces instead of tabs.

In the java formatter link, you have to edit the profile and select the tab policy, spaces only in indentation tab

Multidimensional arrays in Swift

var array: Int[][] = [[1,2,3],[4,5,6],[7,8,9]]

for first in array {
    for second in first {
        println("value \(second)")
    }
}

To achieve what you're looking for you need to initialize the array to the correct template and then loop to add the row and column arrays:

var NumColumns = 27
var NumRows = 52
var array = Array<Array<Int>>()
var value = 1

for column in 0..NumColumns {
    var columnArray = Array<Int>()
    for row in 0..NumRows {
        columnArray.append(value++)
    }
    array.append(columnArray)
}

println("array \(array)")

Play sound on button click android

import android.media.MediaPlayer;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
    MediaPlayer mp;
    Button one;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mp = MediaPlayer.create(this, R.raw.soho);
        one = (Button)this.findViewById(R.id.button1);

        one.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mp.start();
            }
        });
    }
}