Programs & Examples On #Qtcpsocket

The QTcpSocket class, part of the Qt framework, provides a TCP socket.

How to edit default.aspx on SharePoint site without SharePoint Designer

Go to view all content of the site (http://yourdmain.sharepoint/sitename/_layouts/viewlsts.aspx). Select the document library "Pages" (the "Pages" library are named based on the language you created the site in. I.E. in norwegian the library is named "Sider"). Download the default.aspx to you computer and fix it (remove the web part and the <%Register tag). Save it and upload it back to the library (remember to check in the file).

EDIT:

ahh.. you are not using a publishing site template. Go to site action -> site settings. Under "site administration" select the menu "content and structure" you should now see your default.aspx page. But you cant do much with it...(delete, copy or move)

workaround: Enable publishing feature to the root web. Add the fixed default.aspx file to the Pages library and change the welcome page to this. Disable the publishing feature (this will delete all other list create from this feature but not the Pages library since one page is in use.). You will now have a new default.aspx page for the root web but the url is changed from sitename/default.aspx to sitename/Pages/default.aspx.

workaround II Use a feature to change the default.aspx file. The solution is explained here: http://wssguy.com/blogs/dan/archive/2008/10/29/how-to-change-the-default-page-of-a-sharepoint-site-using-a-feature.aspx

SQL Server: how to create a stored procedure

CREATE PROCEDURE [dbo].[USP_StudentInformation]
@S_Name VARCHAR(50)
,@S_Address VARCHAR(500)
AS
BEGIN
SET NOCOUNT ON;

DECLARE @Date VARCHAR(50)

SET @Date = GETDATE()


IF EXISTS (
        SELECT *
        FROM TB_StdFunction
        WHERE S_Name = @S_Name
            AND S_Address = @S_Address
        )
BEGIN
    UPDATE TB_StdFunction
    SET S_Name = @S_Name
        ,S_Address = @S_Address
        ,ModifiedDate = @Date
    WHERE S_Name = @S_Name
        AND S_Address = @S_Address

    SELECT *
    FROM TB_StdFunction
END
ELSE
BEGIN
    INSERT INTO TB_StdFunction (
        S_Name
        ,S_Address
        ,CreatedDate
        )
    VALUES (
        @S_Name
        ,@S_Address
        ,@date          
        )

    SELECT *
    FROM TB_StdFunction
END
END

Table Name :   TB_StdFunction


S_No  INT PRIMARY KEY AUTO_INCREMENT
S_Name nvarchar(50)
S_Address nvarchar(500)
CreatedDate nvarchar(50)
ModifiedDate nvarchar(50)

Can't bind to 'formGroup' since it isn't a known property of 'form'

This problem occurs due to missing import of FormsModule,ReactiveFormsModule .I also came with same problem. My case was diff. as i was working with modules.So i missed above imports in my parent modules though i had imported it into child modules,it wasn't working.

Then i imported it into my parent modules as below, and it worked!

import { ReactiveFormsModule,FormsModule  } from '@angular/forms';
import { AlertModule } from 'ngx-bootstrap';

         @NgModule({
          imports: [
            CommonModule,
            FormsModule,
            ReactiveFormsModule,
    ],
      declarations: [MyComponent]
    })

Get a random item from a JavaScript array

If you are using node.js, you can use unique-random-array. It simply picks something random from an array.

EOFException - how to handle?

Alternatively, you could write out the number of elements first (as a header) using:

out.writeInt(prices.length);

When you read the file, you first read the header (element count):

int elementCount = in.readInt();

for (int i = 0; i < elementCount; i++) {
     // read elements
}

How to sum columns in a dataTable?

It's a pity to use .NET and not use collections and lambda to save your time and code lines This is an example of how this works: Transform yourDataTable to Enumerable, filter it if you want , according a "FILTER_ROWS_FIELD" column, and if you want, group your data by a "A_GROUP_BY_FIELD". Then get the count, the sum, or whatever you wish. If you want a count and a sum without grouby don't group the data

var groupedData = from b in yourDataTable.AsEnumerable().Where(r=>r.Field<int>("FILTER_ROWS_FIELD").Equals(9999))
                          group b by b.Field<string>("A_GROUP_BY_FIELD") into g
                          select new
                          {
                              tag = g.Key,
                              count = g.Count(),
                              sum = g.Sum(c => c.Field<double>("rvMoney"))
                          };

How to get the client IP address in PHP

A quick solution (error free)

function getClientIP():string
{
    $keys=array('HTTP_CLIENT_IP','HTTP_X_FORWARDED_FOR','HTTP_X_FORWARDED','HTTP_FORWARDED_FOR','HTTP_FORWARDED','REMOTE_ADDR');
    foreach($keys as $k)
    {
        if (!empty($_SERVER[$k]) && filter_var($_SERVER[$k], FILTER_VALIDATE_IP))
        {
            return $_SERVER[$k];
        }
    }
    return "UNKNOWN";
}

The remote host closed the connection. The error code is 0x800704CD

I too got this same error on my image handler that I wrote. I got it like 30 times a day on site with heavy traffic, managed to reproduce it also. You get this when a user cancels the request (closes the page or his internet connection is interrupted for example), in my case in the following row:

myContext.Response.OutputStream.Write(buffer, 0, bytesRead);

I can’t think of any way to prevent it but maybe you can properly handle this. Ex:

        try
        {
            …
            myContext.Response.OutputStream.Write(buffer, 0, bytesRead);
            …
        }catch (HttpException ex)
        {
            if (ex.Message.StartsWith("The remote host closed the connection."))
                ;//do nothing
            else
                //handle other errors
        }            
        catch (Exception e)
        {
            //handle other errors
        }
        finally
        {//close streams etc..
        }

Properly escape a double quote in CSV

If a value contains a comma, a newline character or a double quote, then the string must be enclosed in double quotes. E.g: "Newline char in this field \n".

You can use below online tool to escape "" and , operators. https://www.freeformatter.com/csv-escape.html#ad-output

How to hide the title bar for an Activity in XML with existing custom theme

Or if you want to hide/show the title bar at any point:

private void toggleFullscreen(boolean fullscreen)
{
    WindowManager.LayoutParams attrs = getWindow().getAttributes();
    if (fullscreen)
    {
        attrs.flags |= WindowManager.LayoutParams.FLAG_FULLSCREEN;
    }
    else
    {
        attrs.flags &= ~WindowManager.LayoutParams.FLAG_FULLSCREEN;
    }
    getWindow().setAttributes(attrs);
}

Read and write to binary files in C?

This is an example to read and write binary jjpg or wmv video file. FILE *fout; FILE *fin;

Int ch;
char *s;
fin=fopen("D:\\pic.jpg","rb");
if(fin==NULL)
     {  printf("\n Unable to open the file ");
         exit(1);
      }

 fout=fopen("D:\\ newpic.jpg","wb");
 ch=fgetc(fin);
       while (ch!=EOF)
             { 
                  s=(char *)ch;
                  printf("%c",s);
                 ch=fgetc (fin):
                 fputc(s,fout);
                 s++;
              }

        printf("data read and copied");
        fclose(fin);
        fclose(fout);

How do I get rid of the "cannot empty the clipboard" error?

I have seen various answers which say when I uninstalled this or that it worked. I think that the uninstall is probably just sorting out an issue in the registry, rather it being an issue with the particular application that is being uninstalled.

I have also seen cases of people saying kill the RDP task but I don't have that and I still have the error.

I have seen cases of people saying clear the clipboard in Excel, but that doesn't work for me - nor does changing the settings in the Clipboard.

I believe that the issue is that an application has a lock on the clipboard and that application is not releasing it. The clipboard is a shared resource, so that implies that each application has to get a lock on it before changing it and then release the lock once it has completed the change, however, it looks like sometimes the lock is not released.

I found that the following cured it. Close down all MS applications including IE and Outlook. Check Task Manager processes to make sure that they are all gone.

Then restart the application where you had the Copy and Paste issue and it will probably then work.

Regards

Paul Simon

AngularJS - Find Element with attribute

Your use-case isn't clear. However, if you are certain that you need this to be based on the DOM, and not model-data, then this is a way for one directive to have a reference to all elements with another directive specified on them.

The way is that the child directive can require the parent directive. The parent directive can expose a method that allows direct directive to register their element with the parent directive. Through this, the parent directive can access the child element(s). So if you have a template like:

<div parent-directive>
  <div child-directive></div>
  <div child-directive></div>
</div>

Then the directives can be coded like:

app.directive('parentDirective', function($window) {
  return {
    controller: function($scope) {
      var registeredElements = [];
      this.registerElement = function(childElement) {
        registeredElements.push(childElement);
      }
    }
  };
});

app.directive('childDirective', function() {
  return {
    require: '^parentDirective',
    template: '<span>Child directive</span>',
    link: function link(scope, iElement, iAttrs, parentController) {
      parentController.registerElement(iElement);
    }
   };
});

You can see this in action at http://plnkr.co/edit/7zUgNp2MV3wMyAUYxlkz?p=preview

Simple way to compare 2 ArrayLists

Convert Lists to Collection and use removeAll

    Collection<String> listOne = new ArrayList(Arrays.asList("a","b", "c", "d", "e", "f", "g"));
    Collection<String> listTwo = new ArrayList(Arrays.asList("a","b",  "d", "e", "f", "gg", "h"));


    List<String> sourceList = new ArrayList<String>(listOne);
    List<String> destinationList = new ArrayList<String>(listTwo);


    sourceList.removeAll( listTwo );
    destinationList.removeAll( listOne );



    System.out.println( sourceList );
    System.out.println( destinationList );

Output:

[c, g]
[gg, h]

[EDIT]

other way (more clear)

  Collection<String> list = new ArrayList(Arrays.asList("a","b", "c", "d", "e", "f", "g"));

    List<String> sourceList = new ArrayList<String>(list);
    List<String> destinationList = new ArrayList<String>(list);

    list.add("boo");
    list.remove("b");

    sourceList.removeAll( list );
    list.removeAll( destinationList );


    System.out.println( sourceList );
    System.out.println( list );

Output:

[b]
[boo]

What causes HttpHostConnectException?

In my case the issue was a missing 's' in the HTTP URL. Error was: "HttpHostConnectException: Connect to someendpoint.com:80 [someendpoint.com/127.0.0.1] failed: Connection refused" End point and IP obviously changed to protect the network.

How to make a deep copy of Java ArrayList

Cloning the objects before adding them. For example, instead of newList.addAll(oldList);

for(Person p : oldList) {
    newList.add(p.clone());
}

Assuming clone is correctly overriden inPerson.

Disable cache for some images

Changing the image source is the solution. You can indeed do this by adding a timestamp or random number to the image.

Better would be to add a checksum of eg the data the image represents. This enables caching when possible.

Java split string to array

This behavior is explicitly documented in String.split(String regex) (emphasis mine):

This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.

If you want those trailing empty strings included, you need to use String.split(String regex, int limit) with a negative value for the second parameter (limit):

String[] array = values.split("\\|", -1);

Simple way to copy or clone a DataRow?

But to make sure that your new row is accessible in the new table, you need to close the table:

DataTable destination = new DataTable(source.TableName);
destination = source.Clone();
DataRow sourceRow = source.Rows[0];
destination.ImportRow(sourceRow);

How to access a DOM element in React? What is the equilvalent of document.getElementById() in React

For getting the element in react you need to use ref and inside the function you can use the ReactDOM.findDOMNode method.

But what I like to do more is to call the ref right inside the event

<input type="text" ref={ref => this.myTextInput = ref} />

This is some good link to help you figure out.

How can I multiply and divide using only bit shifting and adding?

X * 2 = 1 bit shift left
X / 2 = 1 bit shift right
X * 3 = shift left 1 bit and then add X

How to create a TextArea in Android

       <EditText
            android:layout_width="match_parent"
            android:layout_height="160dp"
            android:ems="10"
            android:gravity="left|top"
            android:hint="Write your comment.."
            android:inputType="textMultiLine"
            android:textSize="15sp">
            <requestFocus />
       </EditText>

Automatic creation date for Django model form objects?

Well, the above answer is correct, auto_now_add and auto_now would do it, but it would be better to make an abstract class and use it in any model where you require created_at and updated_at fields.

class TimeStampMixin(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

Now anywhere you want to use it you can do a simple inherit and you can use timestamp in any model you make like.

class Posts(TimeStampMixin):
    name = models.CharField(max_length=50)
    ...
    ...

In this way, you can leverage object-oriented reusability, in Django DRY(don't repeat yourself)

How to install Openpyxl with pip

  1. Go to https://pypi.org/project/openpyxl/#files
  2. Download the file and unzip in your pc in the main folder, there's a file call setup.py
  3. Install with this command: python setup.py install

How do I use installed packages in PyCharm?

For me, it was just a matter of marking the directory as a source root.

bool to int conversion

There seems to be no problem since the int to bool cast is done implicitly. This works in Microsoft Visual C++, GCC and Intel C++ compiler. No problem in either C or C++.

Installing Node.js (and npm) on Windows 10

You should run the installer as administrator.

  1. Run the command prompt as administrator
  2. cd directory where msi file is present
  3. launch msi file by typing the name in the command prompt
  4. You should be happy to see all node commands work from new command prompt shell

How to Pass Parameters to Activator.CreateInstance<T>()

Yes.

(T)Activator.CreateInstance(typeof(T), param1, param2);

Extract month and year from a zoo::yearmon object

I know the OP is using zoo here, but I found this thread googling for a standard ts solution for the same problem. So I thought I'd add a zoo-free answer for ts as well.

# create an example Date 
date_1 <- as.Date("1990-01-01")
# extract year
as.numeric(format(date_1, "%Y"))
# extract month
as.numeric(format(date_1, "%m"))

Creating a REST API using PHP

In your example, it’s fine as it is: it’s simple and works. The only things I’d suggest are:

  1. validating the data POSTed
  2. make sure your API is sending the Content-Type header to tell the client to expect a JSON response:

    header('Content-Type: application/json');
    echo json_encode($response);
    

Other than that, an API is something that takes an input and provides an output. It’s possible to “over-engineer” things, in that you make things more complicated that need be.

If you wanted to go down the route of controllers and models, then read up on the MVC pattern and work out how your domain objects fit into it. Looking at the above example, I can see maybe a MathController with an add() action/method.

There are a few starting point projects for RESTful APIs on GitHub that are worth a look.

How to write a multidimensional array to a text file?

If you want to write it to disk so that it will be easy to read back in as a numpy array, look into numpy.save. Pickling it will work fine, as well, but it's less efficient for large arrays (which yours isn't, so either is perfectly fine).

If you want it to be human readable, look into numpy.savetxt.

Edit: So, it seems like savetxt isn't quite as great an option for arrays with >2 dimensions... But just to draw everything out to it's full conclusion:

I just realized that numpy.savetxt chokes on ndarrays with more than 2 dimensions... This is probably by design, as there's no inherently defined way to indicate additional dimensions in a text file.

E.g. This (a 2D array) works fine

import numpy as np
x = np.arange(20).reshape((4,5))
np.savetxt('test.txt', x)

While the same thing would fail (with a rather uninformative error: TypeError: float argument required, not numpy.ndarray) for a 3D array:

import numpy as np
x = np.arange(200).reshape((4,5,10))
np.savetxt('test.txt', x)

One workaround is just to break the 3D (or greater) array into 2D slices. E.g.

x = np.arange(200).reshape((4,5,10))
with open('test.txt', 'w') as outfile:
    for slice_2d in x:
        np.savetxt(outfile, slice_2d)

However, our goal is to be clearly human readable, while still being easily read back in with numpy.loadtxt. Therefore, we can be a bit more verbose, and differentiate the slices using commented out lines. By default, numpy.loadtxt will ignore any lines that start with # (or whichever character is specified by the comments kwarg). (This looks more verbose than it actually is...)

import numpy as np

# Generate some test data
data = np.arange(200).reshape((4,5,10))

# Write the array to disk
with open('test.txt', 'w') as outfile:
    # I'm writing a header here just for the sake of readability
    # Any line starting with "#" will be ignored by numpy.loadtxt
    outfile.write('# Array shape: {0}\n'.format(data.shape))
    
    # Iterating through a ndimensional array produces slices along
    # the last axis. This is equivalent to data[i,:,:] in this case
    for data_slice in data:

        # The formatting string indicates that I'm writing out
        # the values in left-justified columns 7 characters in width
        # with 2 decimal places.  
        np.savetxt(outfile, data_slice, fmt='%-7.2f')

        # Writing out a break to indicate different slices...
        outfile.write('# New slice\n')

This yields:

# Array shape: (4, 5, 10)
0.00    1.00    2.00    3.00    4.00    5.00    6.00    7.00    8.00    9.00   
10.00   11.00   12.00   13.00   14.00   15.00   16.00   17.00   18.00   19.00  
20.00   21.00   22.00   23.00   24.00   25.00   26.00   27.00   28.00   29.00  
30.00   31.00   32.00   33.00   34.00   35.00   36.00   37.00   38.00   39.00  
40.00   41.00   42.00   43.00   44.00   45.00   46.00   47.00   48.00   49.00  
# New slice
50.00   51.00   52.00   53.00   54.00   55.00   56.00   57.00   58.00   59.00  
60.00   61.00   62.00   63.00   64.00   65.00   66.00   67.00   68.00   69.00  
70.00   71.00   72.00   73.00   74.00   75.00   76.00   77.00   78.00   79.00  
80.00   81.00   82.00   83.00   84.00   85.00   86.00   87.00   88.00   89.00  
90.00   91.00   92.00   93.00   94.00   95.00   96.00   97.00   98.00   99.00  
# New slice
100.00  101.00  102.00  103.00  104.00  105.00  106.00  107.00  108.00  109.00 
110.00  111.00  112.00  113.00  114.00  115.00  116.00  117.00  118.00  119.00 
120.00  121.00  122.00  123.00  124.00  125.00  126.00  127.00  128.00  129.00 
130.00  131.00  132.00  133.00  134.00  135.00  136.00  137.00  138.00  139.00 
140.00  141.00  142.00  143.00  144.00  145.00  146.00  147.00  148.00  149.00 
# New slice
150.00  151.00  152.00  153.00  154.00  155.00  156.00  157.00  158.00  159.00 
160.00  161.00  162.00  163.00  164.00  165.00  166.00  167.00  168.00  169.00 
170.00  171.00  172.00  173.00  174.00  175.00  176.00  177.00  178.00  179.00 
180.00  181.00  182.00  183.00  184.00  185.00  186.00  187.00  188.00  189.00 
190.00  191.00  192.00  193.00  194.00  195.00  196.00  197.00  198.00  199.00 
# New slice

Reading it back in is very easy, as long as we know the shape of the original array. We can just do numpy.loadtxt('test.txt').reshape((4,5,10)). As an example (You can do this in one line, I'm just being verbose to clarify things):

# Read the array from disk
new_data = np.loadtxt('test.txt')

# Note that this returned a 2D array!
print new_data.shape

# However, going back to 3D is easy if we know the 
# original shape of the array
new_data = new_data.reshape((4,5,10))
    
# Just to check that they're the same...
assert np.all(new_data == data)

Vector erase iterator

Something that you can do with modern C++ is using "std::remove_if" and lambda expression;

This code will remove "3" of the vector

vector<int> vec {1,2,3,4,5,6};

vec.erase(std::remove_if(begin(vec),end(vec),[](int elem){return (elem == 3);}), end(vec));

can't start MySql in Mac OS 10.6 Snow Leopard

In order just to get MySQL working again (I haven't yet looked at startup), there is no need to reinstall . I've got my copy working by doing the following:

What you need to do is this:

sudo ln -s /usr/local/mysql-5.0.51a-osx10.5-x86_64 /usr/local/mysql

This creates a symbolic link from the /usr/local/mysql directory to the location where MySQL is. This is critical, because unless you carefully backed up all your databases with mysqldump before running the Leopard upgrade, that's where all your data lives - and restoring it simply from a whole-hard-drive backup is going to be hard.

Now you can go to the right directory and start up mysql:

cd /usr/local/mysql-5.0.51a-osx10.5-x86_64

sudo ./bin/mysqld_safe

You can now do the usual CTRL-Z to get back to the shell. To make sure mysqld is running, type:

sudo ps -A|grep mysql

I got something like this:

1220 ttys000 0:00.02 /bin/sh ./bin/mysqld_safe
1240 ttys000 0:00.39 /usr/local/mysql-5.0.51a-osx10.5-x86_64/bin/mysqld --basedir=/usr/local/mysql-5.0.51a-osx10.5-x86_64 --datadir=/usr/local/mysql-5.0.51a-osx10.5-x86_64/data --user=mysql --pid-file=/usr/local/mysql-5.0.51a-osx10.5-x86_64/data/dkmac-2.home.pid --port=3306 --socket=/tmp/mysql.soc

My copy of mysql now seems to work fine. At the very least, it's good enough to run mysqldump on all my databases, so that if I need to upgrade mysql by other means and dump my data directory, I'm still in good shape.

Android: adb pull file on desktop

do adb pull \sdcard\log.txt C:Users\admin\Desktop

Eclipse JUnit - possible causes of seeing "initializationError" in Eclipse window

I had the same problem: Once it was excel path issue and other time it was missing @Test annotation.

java.util.zip.ZipException: duplicate entry during packageAllDebugClassesForMultiDex

My understanding is that there are duplicate references to the same API (Likely different version numbers). It should be reasonably easy to debug when building from the command line.

Try ./gradlew yourBuildVariantName --debug from the command line.

The offending item will be the first failure. An example might look like:

14:32:29.171 [INFO] [org.gradle.api.Task] INPUT: /Users/mydir/Documents/androidApp/BaseApp/build/intermediates/exploded-aar/theOffendingAAR/libs/google-play-services.jar

14:32:29.171 [DEBUG] [org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter] Finished executing task ':BaseApp:packageAllyourBuildVariantNameClassesForMultiDex'

14:32:29.172 [LIFECYCLE] [class org.gradle.TaskExecutionLogger] :BaseApp:packageAllyourBuildVariantNameClassesForMultiDex FAILED'

In the case above, the aar file that I'd included in my libs directory (theOffendingAAR) included the Google Play Services jar (yes the whole thing. yes I know.) file whilst my BaseApp build file utilised location services:

compile 'com.google.android.gms:play-services-location:6.5.87'

You can safely remove the offending item from your build file(s), clean and rebuild (repeat if necessary).

Copying sets Java

The copy constructor given by @Stephen C is the way to go when you have a Set you created (or when you know where it comes from). When it comes from a Map.entrySet(), it will depend on the Map implementation you're using:

findbugs says

The entrySet() method is allowed to return a view of the underlying Map in which a single Entry object is reused and returned during the iteration. As of Java 1.6, both IdentityHashMap and EnumMap did so. When iterating through such a Map, the Entry value is only valid until you advance to the next iteration. If, for example, you try to pass such an entrySet to an addAll method, things will go badly wrong.

As addAll() is called by the copy constructor, you might find yourself with a Set of only one Entry: the last one.

Not all Map implementations do that though, so if you know your implementation is safe in that regard, the copy constructor definitely is the way to go. Otherwise, you'd have to create new Entry objects yourself:

Set<K,V> copy = new HashSet<K,V>(map.size());
for (Entry<K,V> e : map.entrySet())
    copy.add(new java.util.AbstractMap.SimpleEntry<K,V>(e));

Edit: Unlike tests I performed on Java 7 and Java 6u45 (thanks to Stephen C), the findbugs comment does not seem appropriate anymore. It might have been the case on earlier versions of Java 6 (before u45) but I don't have any to test.

How can I loop through a List<T> and grab each item?

Just like any other collection. With the addition of the List<T>.ForEach method.

foreach (var item in myMoney)
    Console.WriteLine("amount is {0}, and type is {1}", item.amount, item.type);

for (int i = 0; i < myMoney.Count; i++)
    Console.WriteLine("amount is {0}, and type is {1}", myMoney[i].amount, myMoney[i].type);

myMoney.ForEach(item => Console.WriteLine("amount is {0}, and type is {1}", item.amount, item.type));

What is the difference between JOIN and JOIN FETCH when using JPA and Hibernate

Dherik : I'm not sure about what you say, when you don't use fetch the result will be of type : List<Object[ ]> which means a list of Object tables and not a list of Employee.

Object[0] refers an Employee entity 
Object[1] refers a Departement entity 

When you use fetch, there is just one select and the result is the list of Employee List<Employee> containing the list of departements. It overrides the lazy declaration of the entity.

How can I round down a number in Javascript?

To round down towards negative infinity, use:

rounded=Math.floor(number);

To round down towards zero (if the number can round to a 32-bit integer between -2147483648 and 2147483647), use:

rounded=number|0;

To round down towards zero (for any number), use:

if(number>0)rounded=Math.floor(number);else rounded=Math.ceil(number);

Running a shell script through Cygwin on Windows

The existing answers all seem to run this script in a DOS console window.

This may be acceptable, but for example means that colour codes (changing text colour) don't work but instead get printed out as they are:

there is no item "[032mGroovy[0m"

I found this solution some time ago, so I'm not sure whether mintty.exe is a standard Cygwin utility or whether you have to run the setup program to get it, but I run like this:

D:\apps\cygwin64\bin\mintty.exe -i /Cygwin-Terminal.ico  bash.exe .\myShellScript.sh

... this causes the script to run in a Cygwin BASH console instead of a Windows DOS console.

Best way to Bulk Insert from a C# DataTable

Here's how I do it using a DataTable. This is a working piece of TEST code.

using (SqlConnection con = new SqlConnection(connStr))
{
    con.Open();

    // Create a table with some rows. 
    DataTable table = MakeTable();

    // Get a reference to a single row in the table. 
    DataRow[] rowArray = table.Select();

    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(con))
    {
        bulkCopy.DestinationTableName = "dbo.CarlosBulkTestTable";

        try
        {
            // Write the array of rows to the destination.
            bulkCopy.WriteToServer(rowArray);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

    }

}//using

Rails: How can I rename a database column in a Ruby on Rails migration?

Manually we can use the below method:

We can edit the migration manually like:

  • Open app/db/migrate/xxxxxxxxx_migration_file.rb

  • Update hased_password to hashed_password

  • Run the below command

    $> rake db:migrate:down VERSION=xxxxxxxxx
    

Then it will remove your migration:

$> rake db:migrate:up VERSION=xxxxxxxxx

It will add your migration with the updated change.

How would I find the second largest salary from the employee table?

To find second max salary from employee,

SELECT MAX(salary) FROM employee
WHERE salary NOT IN (
    SELECT MAX (salary) FROM employee
)

To find first and second max salary from employee,

SELECT salary FROM (
    SELECT DISTINCT(salary) FROM employee ORDER BY salary DESC
) WHERE rownum<=2

This queries are working fine because i have used

PowerShell script to return versions of .NET Framework on a machine?

If you have installed Visual Studio on your machine then open the Visual Studio Developer Command Prompt and type the following command: clrver

It will list all the installed versions of .NET Framework on that machine.

What's the best way to get the current URL in Spring MVC?

If you need the URL till hostname and not the path use Apache's Common Lib StringUtil, and from URL extract the substring till third indexOf /.

public static String getURL(HttpServletRequest request){
   String fullURL = request.getRequestURL().toString();
   return fullURL.substring(0,StringUtils.ordinalIndexOf(fullURL, "/", 3)); 
}

Example: If fullURL is https://example.com/path/after/url/ then Output will be https://example.com

IE Driver download location Link for Selenium

Use the below link to download IE Driver latest version

IE Driver

Best way to work with transactions in MS SQL Server Management Studio

The easisest thing to do is to wrap your code in a transaction, and then execute each batch of T-SQL code line by line.

For example,

Begin Transaction

         -Do some T-SQL queries here.

Rollback transaction -- OR commit transaction

If you want to incorporate error handling you can do so by using a TRY...CATCH BLOCK. Should an error occur you can then rollback the tranasction within the catch block.

For example:

USE AdventureWorks;
GO
BEGIN TRANSACTION;

BEGIN TRY
    -- Generate a constraint violation error.
    DELETE FROM Production.Product
    WHERE ProductID = 980;
END TRY
BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber
        ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState
        ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine
        ,ERROR_MESSAGE() AS ErrorMessage;

    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH;

IF @@TRANCOUNT > 0
    COMMIT TRANSACTION;
GO

See the following link for more details.

http://msdn.microsoft.com/en-us/library/ms175976.aspx

Hope this helps but please let me know if you need more details.

Set content of HTML <span> with Javascript

To do it without using a JavaScript library such as jQuery, you'd do it like this:

var span = document.getElementById("myspan"),
    text = document.createTextNode(''+intValue);
span.innerHTML = ''; // clear existing
span.appendChild(text);

If you do want to use jQuery, it's just this:

$("#myspan").text(''+intValue);

How can I load the contents of a text file into a batch file variable?

If your set command supports the /p switch, then you can pipe input that way.

set /p VAR1=<test.txt
set /? |find "/P"

The /P switch allows you to set the value of a variable to a line of input entered by the user. Displays the specified promptString before reading the line of input. The promptString can be empty.

This has the added benefit of working for un-registered file types (which the accepted answer does not).

What is the "-->" operator in C/C++?

Utterly geek, but I will be using this:

#define as ;while

int main(int argc, char* argv[])
{
    int n = atoi(argv[1]);
    do printf("n is %d\n", n) as ( n --> 0);
    return 0;
}

How to make a shape with left-top round rounded corner and left-bottom rounded corner?

This bug is filed here. This is a bug of android devices having API level less than 12. You've to put correct versions of your layouts in drawable-v12 folder which will be used for API level 12 or higher. And an erroneous version(corners switched/reversed) of the same layout will be put in the default drawable folder which will be used by the devices having API level less than 12.

For example: I had to design a button with rounded corner at bottom-right.

In 'drawable' folder - button.xml: I had to make bottom-left corner rounded.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

In 'drawable-v12' folder - button.xml: Correct version of the layout was placed here to be used for API level 12 or higher.

<shape>
    <corners android:bottomLeftRadius="15dp"/>
</shape>

try/catch with InputMismatchException creates infinite loop

To follow debobroto das's answer you can also put after

input.reset();
input.next(); 

I had the same problem and when I tried this. It completely fixed it.

Hidden features of Windows batch files

I really like this Windows XP Commands reference, as well as the Syntax link at the top; it covers many of the tips and tricks already found in other answers.

How do I target only Internet Explorer 10 for certain situations like Internet Explorer-specific CSS or Internet Explorer-specific JavaScript code?

I use this script - it's antiquated, but effective in targeting a separate Internet Explorer 10 style sheet or JavaScript file that is included only if the browser is Internet Explorer 10, the same way you would with conditional comments. No jQuery or other plugin is required.

<script>
    /*@cc_on
      @if (@_jscript_version == 10)
          document.write(' <link type= "text/css" rel="stylesheet" href="your-ie10-styles.css" />');
      @end
    @*/
</script >

Formatting a double to two decimal places

Since you are working in currency why not simply do this:

Console.Writeline("Earnings this week: {0:c}", answer);

This will format answer as currency, so on my machine (UK) it will come out as:

Earnings this week: £209.00

How do you programmatically update query params in react-router?

It can also be written this way

this.props.history.push(`${window.location.pathname}&page=${pageNumber}`)

Where can I find the API KEY for Firebase Cloud Messaging?

You can find your Firebase Web API Key in the follwing way .

Go To project overview -> general -> web API key

How to export database schema in Oracle to a dump file

It depends on which version of Oracle? Older versions require exp (export), newer versions use expdp (data pump); exp was deprecated but still works most of the time.

Before starting, note that Data Pump exports to the server-side Oracle "directory", which is an Oracle symbolic location mapped in the database to a physical location. There may be a default directory (DATA_PUMP_DIR), check by querying DBA_DIRECTORIES:

  SQL> select * from dba_directories;

... and if not, create one

  SQL> create directory DATA_PUMP_DIR as '/oracle/dumps';
  SQL> grant all on directory DATA_PUMP_DIR to myuser;    -- DBAs dont need this grant

Assuming you can connect as the SYSTEM user, or another DBA, you can export any schema like so, to the default directory:

 $ expdp system/manager schemas=user1 dumpfile=user1.dpdmp

Or specifying a specific directory, add directory=<directory name>:

 C:\> expdp system/manager schemas=user1 dumpfile=user1.dpdmp directory=DUMPDIR

With older export utility, you can export to your working directory, and even on a client machine that is remote from the server, using:

 $ exp system/manager owner=user1 file=user1.dmp

Make sure the export is done in the correct charset. If you haven't setup your environment, the Oracle client charset may not match the DB charset, and Oracle will do charset conversion, which may not be what you want. You'll see a warning, if so, then you'll want to repeat the export after setting NLS_LANG environment variable so the client charset matches the database charset. This will cause Oracle to skip charset conversion.

Example for American UTF8 (UNIX):

 $ export NLS_LANG=AMERICAN_AMERICA.AL32UTF8

Windows uses SET, example using Japanese UTF8:

 C:\> set NLS_LANG=Japanese_Japan.AL32UTF8

More info on Data Pump here: http://docs.oracle.com/cd/B28359_01/server.111/b28319/dp_export.htm#g1022624

READ_EXTERNAL_STORAGE permission for Android

Please Check below code that using that You can find all Music Files from sdcard :

public class MainActivity extends Activity{

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

}

public void getAllSongsFromSDCARD() {
    String[] STAR = { "*" };
    Cursor cursor;
    Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";

    cursor = managedQuery(allsongsuri, STAR, selection, null, null);

    if (cursor != null) {
        if (cursor.moveToFirst()) {
            do {
                String song_name = cursor
                        .getString(cursor
                                .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
                int song_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media._ID));

                String fullpath = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.DATA));

                String album_name = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ALBUM));
                int album_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));

                String artist_name = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ARTIST));
                int artist_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));
                System.out.println("sonng name"+fullpath);
            } while (cursor.moveToNext());

        }
        cursor.close();
    }
}


}

I have also added following line in the AndroidManifest.xml file as below:

<uses-sdk
    android:minSdkVersion="16"
    android:targetSdkVersion="17" />

<uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

C dynamically growing array

As with everything that seems scarier at first than it was later, the best way to get over the initial fear is to immerse yourself into the discomfort of the unknown! It is at times like that which we learn the most, after all.

Unfortunately, there are limitations. While you're still learning to use a function, you shouldn't assume the role of a teacher, for example. I often read answers from those who seemingly don't know how to use realloc (i.e. the currently accepted answer!) telling others how to use it incorrectly, occasionally under the guise that they've omitted error handling, even though this is a common pitfall which needs mention. Here's an answer explaining how to use realloc correctly. Take note that the answer is storing the return value into a different variable in order to perform error checking.

Every time you call a function, and every time you use an array, you are using a pointer. The conversions are occurring implicitly, which if anything should be even scarier, as it's the things we don't see which often cause the most problems. For example, memory leaks...

Array operators are pointer operators. array[x] is really a shortcut for *(array + x), which can be broken down into: * and (array + x). It's most likely that the * is what confuses you. We can further eliminate the addition from the problem by assuming x to be 0, thus, array[0] becomes *array because adding 0 won't change the value...

... and thus we can see that *array is equivalent to array[0]. You can use one where you want to use the other, and vice versa. Array operators are pointer operators.

malloc, realloc and friends don't invent the concept of a pointer which you've been using all along; they merely use this to implement some other feature, which is a different form of storage duration, most suitable when you desire drastic, dynamic changes in size.

It is a shame that the currently accepted answer also goes against the grain of some other very well-founded advice on StackOverflow, and at the same time, misses an opportunity to introduce a little-known feature which shines for exactly this usecase: flexible array members! That's actually a pretty broken answer... :(

When you define your struct, declare your array at the end of the structure, without any upper bound. For example:

struct int_list {
    size_t size;
    int value[];
};

This will allow you to unite your array of int into the same allocation as your count, and having them bound like this can be very handy!

sizeof (struct int_list) will act as though value has a size of 0, so it'll tell you the size of the structure with an empty list. You still need to add to the size passed to realloc to specify the size of your list.

Another handy tip is to remember that realloc(NULL, x) is equivalent to malloc(x), and we can use this to simplify our code. For example:

int push_back(struct int_list **fubar, int value) {
    size_t x = *fubar ? fubar[0]->size : 0
         , y = x + 1;

    if ((x & y) == 0) {
        void *temp = realloc(*fubar, sizeof **fubar
                                   + (x + y) * sizeof fubar[0]->value[0]);
        if (!temp) { return 1; }
        *fubar = temp; // or, if you like, `fubar[0] = temp;`
    }

    fubar[0]->value[x] = value;
    fubar[0]->size = y;
    return 0;
}

struct int_list *array = NULL;

The reason I chose to use struct int_list ** as the first argument may not seem immediately obvious, but if you think about the second argument, any changes made to value from within push_back would not be visible to the function we're calling from, right? The same goes for the first argument, and we need to be able to modify our array, not just here but possibly also in any other function/s we pass it to...

array starts off pointing at nothing; it is an empty list. Initialising it is the same as adding to it. For example:

struct int_list *array = NULL;
if (!push_back(&array, 42)) {
    // success!
}

P.S. Remember to free(array); when you're done with it!

Receiver not registered exception error?

EDIT: This is the answer for inazaruk and electrichead... I had run into a similar issue to them and found out the following...

There is a long-standing bug for this problem here: http://code.google.com/p/android/issues/detail?id=6191

Looks like it started around Android 2.1 and has been present in all of the Android 2.x releases since. I'm not sure if it is still a problem in Android 3.x or 4.x though.

Anyway, this StackOverflow post explains how to workaround the problem correctly (it doesn't look relevant by the URL but I promise it is)

Why does keyboard-slide crash my app?

MySQL Workbench Edit Table Data is read only

If your query has any JOINs, Mysql Workbench will not allow you to alter the table, even if your results are all from a single table.

For example, the following query

SELECT u.* FROM users u JOIN passwords p ON u.id=p.user_id WHERE p.password IS NULL;

will not allow you to edit the results or add rows, even though the results are limited to one table. You must specifically do something like:

SELECT * FROM users WHERE id=1012;

and then you can edit the row and add rows to the table.

Are parameters in strings.xml possible?

If you need to format your strings using String.format(String, Object...), then you can do so by putting your format arguments in the string resource. For example, with the following resource:

<string name="welcome_messages">Hello, %1$s! You have %2$d new messages.</string>

In this example, the format string has two arguments: %1$s is a string and %2$d is a decimal number. You can format the string with arguments from your application like this:

Resources res = getResources();
String text = String.format(res.getString(R.string.welcome_messages), username, mailCount);

If you wish more look at: http://developer.android.com/intl/pt-br/guide/topics/resources/string-resource.html#FormattingAndStyling

SQL how to increase or decrease one for a int column in one command

The single-step answer to the first question is to use something like:

update TBL set CLM = CLM + 1 where key = 'KEY'

That's very much a single-instruction way of doing it.

As for the second question, you shouldn't need to resort to DBMS-specific SQL gymnastics (like UPSERT) to get the result you want. There's a standard method to do update-or-insert that doesn't require a specific DBMS.

try:
    insert into TBL (key,val) values ('xyz',0)
catch:
    do nothing
update TBL set val = val + 1 where key = 'xyz'

That is, you try to do the creation first. If it's already there, ignore the error. Otherwise you create it with a 0 value.

Then do the update which will work correctly whether or not:

  • the row originally existed.
  • someone updated it between your insert and update.

It's not a single instruction and yet, surprisingly enough, it's how we've been doing it successfully for a long long time.

Python error: AttributeError: 'module' object has no attribute

When you import lib, you're importing the package. The only file to get evaluated and run in this case is the 0 byte __init__.py in the lib directory.

If you want access to your function, you can do something like this from lib.mod1 import mod1 and then run the mod12 function like so mod1.mod12().

If you want to be able to access mod1 when you import lib, you need to put an import mod1 inside the __init__.py file inside the lib directory.

Difference between if () { } and if () : endif;

I personally really hate the alternate syntax. One nice thing about the braces is that most IDEs, vim, etc all have bracket highlighting. In my text editor I can double click a brace and it will highlight the whole chunk so I can see where it ends and begins very easily.

I don't know of a single editor that can highlight endif, endforeach, etc.

Converting Hexadecimal String to Decimal Integer

Since there is no brute-force approach which (done with it manualy). To know what exactly happened.

Given a hexadecimal number

K?K??1K??2....K2K1K0

The equivalent decimal value is:

K? * 16? + K??1 * 16??1 + K??2 * 16??2 + .... + K2 * 162 + K1 * 161 + K0 * 160

For example, the hex number AB8C is:

10 * 163 + 11 * 162 + 8 * 161 + 12 * 160 = 43916

Implementation:

 //convert hex to decimal number
private static int hexToDecimal(String hex) {
    int decimalValue = 0;
    for (int i = 0; i < hex.length(); i++) {
        char hexChar = hex.charAt(i);
        decimalValue = decimalValue * 16 + hexCharToDecimal(hexChar);
    }
    return decimalValue;
}
private static int hexCharToDecimal(char character) {
    if (character >= 'A' && character <= 'F')
        return 10 + character - 'A';
    else //character is '0', '1',....,'9'
        return character - '0';
}

open a url on click of ok button in android

On Button click event write this:

Uri uri = Uri.parse("http://www.google.com"); // missing 'http://' will cause crashed
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);

that open the your URL.

Apple Cover-flow effect using jQuery or other library?

Not sure if you're talking about Coverflow (scroll through images) or Quicklook (preview files in lightbox), try editing your question.

Here's some JS Coverflow implementations:

wordpress contactform7 textarea cols and rows change in smaller screens

I was able to get this work. I added the following to my custom CSS:

.wpcf7-form textarea{ 
    width: 100% !important;
    height:50px;
}

Scala: write string to file in one statement

You can easily use Apache File Utils. Look at function writeStringToFile. We use this library in our projects.

PHP add elements to multidimensional array with array_push

As in the multi-dimensional array an entry is another array, specify the index of that value to array_push:

array_push($md_array['recipe_type'], $newdata);

VBA Go to last empty row

This does it:

Do
   c = c + 1
Loop While Cells(c, "A").Value <> ""

'prints the last empty row
Debug.Print c

How to create range in Swift?

Updated for Swift 4

Swift ranges are more complex than NSRange, and they didn't get any easier in Swift 3. If you want to try to understand the reasoning behind some of this complexity, read this and this. I'll just show you how to create them and when you might use them.

Closed Ranges: a...b

This range operator creates a Swift range which includes both element a and element b, even if b is the maximum possible value for a type (like Int.max). There are two different types of closed ranges: ClosedRange and CountableClosedRange.

1. ClosedRange

The elements of all ranges in Swift are comparable (ie, they conform to the Comparable protocol). That allows you to access the elements in the range from a collection. Here is an example:

let myRange: ClosedRange = 1...3

let myArray = ["a", "b", "c", "d", "e"]
myArray[myRange] // ["b", "c", "d"]

However, a ClosedRange is not countable (ie, it does not conform to the Sequence protocol). That means you can't iterate over the elements with a for loop. For that you need the CountableClosedRange.

2. CountableClosedRange

This is similar to the last one except now the range can also be iterated over.

let myRange: CountableClosedRange = 1...3

let myArray = ["a", "b", "c", "d", "e"]
myArray[myRange] // ["b", "c", "d"]

for index in myRange {
    print(myArray[index])
}

Half-Open Ranges: a..<b

This range operator includes element a but not element b. Like above, there are two different types of half-open ranges: Range and CountableRange.

1. Range

As with ClosedRange, you can access the elements of a collection with a Range. Example:

let myRange: Range = 1..<3

let myArray = ["a", "b", "c", "d", "e"]
myArray[myRange] // ["b", "c"]

Again, though, you cannot iterate over a Range because it is only comparable, not stridable.

2. CountableRange

A CountableRange allows iteration.

let myRange: CountableRange = 1..<3

let myArray = ["a", "b", "c", "d", "e"]
myArray[myRange] // ["b", "c"]

for index in myRange {
    print(myArray[index])
}

NSRange

You can (must) still use NSRange at times in Swift (when making attributed strings, for example), so it is helpful to know how to make one.

let myNSRange = NSRange(location: 3, length: 2)

Note that this is location and length, not start index and end index. The example here is similar in meaning to the Swift range 3..<5. However, since the types are different, they are not interchangeable.

Ranges with Strings

The ... and ..< range operators are a shorthand way of creating ranges. For example:

let myRange = 1..<3

The long hand way to create the same range would be

let myRange = CountableRange<Int>(uncheckedBounds: (lower: 1, upper: 3)) // 1..<3

You can see that the index type here is Int. That doesn't work for String, though, because Strings are made of Characters and not all characters are the same size. (Read this for more info.) An emoji like , for example, takes more space than the letter "b".

Problem with NSRange

Try experimenting with NSRange and an NSString with emoji and you'll see what I mean. Headache.

let myNSRange = NSRange(location: 1, length: 3)

let myNSString: NSString = "abcde"
myNSString.substring(with: myNSRange) // "bcd"

let myNSString2: NSString = "acde"
myNSString2.substring(with: myNSRange) // "c"    Where is the "d"!?

The smiley face takes two UTF-16 code units to store, so it gives the unexpected result of not including the "d".

Swift Solution

Because of this, with Swift Strings you use Range<String.Index>, not Range<Int>. The String Index is calculated based on a particular string so that it knows if there are any emoji or extended grapheme clusters.

Example

var myString = "abcde"
let start = myString.index(myString.startIndex, offsetBy: 1)
let end = myString.index(myString.startIndex, offsetBy: 4)
let myRange = start..<end
myString[myRange] // "bcd"

myString = "acde"
let start2 = myString.index(myString.startIndex, offsetBy: 1)
let end2 = myString.index(myString.startIndex, offsetBy: 4)
let myRange2 = start2..<end2
myString[myRange2] // "cd"

One-sided Ranges: a... and ...b and ..<b

In Swift 4 things were simplified a bit. Whenever the starting or ending point of a range can be inferred, you can leave it off.

Int

You can use one-sided integer ranges to iterate over collections. Here are some examples from the documentation.

// iterate from index 2 to the end of the array
for name in names[2...] {
    print(name)
}

// iterate from the beginning of the array to index 2
for name in names[...2] {
    print(name)
}

// iterate from the beginning of the array up to but not including index 2
for name in names[..<2] {
    print(name)
}

// the range from negative infinity to 5. You can't iterate forward
// over this because the starting point in unknown.
let range = ...5
range.contains(7)   // false
range.contains(4)   // true
range.contains(-1)  // true

// You can iterate over this but it will be an infinate loop 
// so you have to break out at some point.
let range = 5...

String

This also works with String ranges. If you are making a range with str.startIndex or str.endIndex at one end, you can leave it off. The compiler will infer it.

Given

var str = "Hello, playground"
let index = str.index(str.startIndex, offsetBy: 5)

let myRange = ..<index    // Hello

You can go from the index to str.endIndex by using ...

var str = "Hello, playground"
let index = str.index(str.endIndex, offsetBy: -10)
let myRange = index...        // playground

See also:

Notes

  • You can't use a range you created with one string on a different string.
  • As you can see, String ranges are a pain in Swift, but they do make it possibly to deal better with emoji and other Unicode scalars.

Further Study

Starting ssh-agent on Windows 10 fails: "unable to start ssh-agent service, error :1058"

Yeah, as others have suggested, this error seems to mean that ssh-agent is installed but its service (on windows) hasn't been started.

You can check this by running in Windows PowerShell:

> Get-Service ssh-agent

And then check the output of status is not running.

Status   Name               DisplayName
------   ----               -----------
Stopped  ssh-agent          OpenSSH Authentication Agent

Then check that the service has been disabled by running

> Get-Service ssh-agent | Select StartType

StartType
---------
Disabled

I suggest setting the service to start manually. This means that as soon as you run ssh-agent, it'll start the service. You can do this through the Services GUI or you can run the command in admin mode:

 > Get-Service -Name ssh-agent | Set-Service -StartupType Manual

Alternatively, you can set it through the GUI if you prefer.

services.msc showing the properties of the OpenSSH Agent

PHP Get name of current directory

Actually I found the best solution is the following:

$cur_dir = explode('\\', getcwd());
echo $cur_dir[count($cur_dir)-1];

if your dir is www\var\path\ Current_Path

then this returns Current_path

Python: SyntaxError: non-keyword after keyword arg

It's just what it says:

inputFile = open((x), encoding = "utf8", "r")

You have specified encoding as a keyword argument, but "r" as a positional argument. You can't have positional arguments after keyword arguments. Perhaps you wanted to do:

inputFile = open((x), "r", encoding = "utf8")

Increase JVM max heap size for Eclipse

You can use this configuration:

-startup
plugins/org.eclipse.equinox.launcher_1.3.0.v20120522-1813.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.gtk.linux.x86_64_1.1.200.v20120913-144807
-showsplash
org.eclipse.platform
--launcher.XXMaxPermSize
256m
--launcher.defaultAction
openFile
-vmargs
-Xms512m
-Xmx1024m
-XX:+UseParallelGC
-XX:PermSize=256M
-XX:MaxPermSize=512M

Setting a width and height on an A tag

You can also use display: inline-block. The advantage of this is that it will set the height and width like a block element but also set it inline so that you can have another a tag sitting right next to it, permitting the parent space.

You can find out more about display properties here

bash string equality

There's no difference, == is a synonym for = (for the C/C++ people, I assume). See here, for example.

You could double-check just to be really sure or just for your interest by looking at the bash source code, should be somewhere in the parsing code there, but I couldn't find it straightaway.

Check if string has space in between (or anywhere)

How about:

myString.Any(x => Char.IsWhiteSpace(x))

Or if you like using the "method group" syntax:

myString.Any(Char.IsWhiteSpace)

Removing X-Powered-By

I think that is controlled by the expose_php setting in PHP.ini:

expose_php = off

Decides whether PHP may expose the fact that it is installed on the server (e.g. by adding its signature to the Web server header). It is no security threat in any way, but it makes it possible to determine whether you use PHP on your server or not.

There is no direct security risk, but as David C notes, exposing an outdated (and possibly vulnerable) version of PHP may be an invitation for people to try and attack it.

Using git commit -a with vim

See this thread for an explanation: VIM for Windows - What do I type to save and exit from a file?

As I wrote there: to learn Vimming, you could use one of the quick reference cards:

Also note How can I set up an editor to work with Git on Windows? if you're not comfortable in using Vim but want to use another editor for your commit messages.

If your commit message is not too long, you could also type

git commit -a -m "your message here"

Bootstrap $('#myModal').modal('show') is not working

My root cause was that I forgot to add the # before the id name. Lame but true.

From

$('scheduleModal').modal('show');

To

$('#scheduleModal').modal('show');

For your reference, the code sequence that works for me is

<script>
function scheduleRequest() {
        $('#scheduleModal').modal('show');
    }
</script>
<script src="<c:url value="/resources/bootstrap/js/bootstrap.min.js"/>">
</script>
<script
    src="<c:url value="/resources/plugins/fastclick/fastclick.min.js"/>">
</script>
<script
    src="<c:url value="/resources/plugins/slimScroll/jquery.slimscroll.min.js"/>">
</script>
<script
    src="<c:url value="/resources/plugins/datatables/jquery.dataTables.min.js"/>">  
</script>
<script
    src="<c:url value="/resources/plugins/datatables/dataTables.bootstrap.min.js"/>">
</script>
<script src="<c:url value="/resources/dist/js/demo.js"/>">
</script>

How do I find the authoritative name-server for a domain name?

An easy way is to use an online domain tool. My favorite is Domain Tools (formerly whois.sc). I'm not sure if they can resolve conflicting DNS records though. As an example, the DNS servers for stackoverflow.com are

  NS51.DOMAINCONTROL.COM
  NS52.DOMAINCONTROL.COM

Loop through files in a directory using PowerShell

To get the content of a directory you can use

$files = Get-ChildItem "C:\Users\gerhardl\Documents\My Received Files\"

Then you can loop over this variable as well:

for ($i=0; $i -lt $files.Count; $i++) {
    $outfile = $files[$i].FullName + "out" 
    Get-Content $files[$i].FullName | Where-Object { ($_ -match 'step4' -or $_ -match 'step9') } | Set-Content $outfile
}

An even easier way to put this is the foreach loop (thanks to @Soapy and @MarkSchultheiss):

foreach ($f in $files){
    $outfile = $f.FullName + "out" 
    Get-Content $f.FullName | Where-Object { ($_ -match 'step4' -or $_ -match 'step9') } | Set-Content $outfile
}

How do I run Python script using arguments in windows command line

Your indentation is broken. This should fix it:

import sys

def hello(a,b):
    print 'hello and thats your sum:'
    sum=a+b
    print sum

if __name__ == "__main__":
    hello(sys.argv[1], sys.argv[2])

Obviously, if you put the if __name__ statement inside the function, it will only ever be evaluated if you run that function. The problem is: the point of said statement is to run the function in the first place.

Git error when trying to push -- pre-receive hook declined

For me everything was working fine until Bitbucket automatically changed their policy today (April 21, 2020). This happens to align with a new feature recently introduced today called Workspaces, so I suspect it has something to do with that.

Workaround: I (as an Admin) followed the instructions to add the email address to Users in the UI (the email you are using can be found git config --list

enter image description here

pthread_join() and pthread_exit()

It because every time

void pthread_exit(void *ret);

will be called from thread function so which ever you want to return simply its pointer pass with pthread_exit().

Now at

int pthread_join(pthread_t tid, void **ret);

will be always called from where thread is created so here to accept that returned pointer you need double pointer ..

i think this code will help you to understand this

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

void* thread_function(void *ignoredInThisExample)
{
    char *a = malloc(10);
    strcpy(a,"hello world");
    pthread_exit((void*)a);
}
int main()
{
    pthread_t thread_id;
    char *b;

    pthread_create (&thread_id, NULL,&thread_function, NULL);

    pthread_join(thread_id,(void**)&b); //here we are reciving one pointer 
                                        value so to use that we need double pointer 
    printf("b is %s\n",b); 
    free(b); // lets free the memory

}

How to debug .htaccess RewriteRule not working

Perhaps a more logical method would be to create a file (e.g. test.html), add some content and then try to set it as the index page:

DirectoryIndex test.html

For the most part, the .htaccess rule will override the Apache configuration where working at the directory/file level

Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

In order to prevent StaleObjectStateException, in your hbm file write below code:

<timestamp name="lstUpdTstamp" column="LST_UPD_TSTAMP" source="db"/>

Maven: How to include jars, which are not available in reps into a J2EE project?

You need to set up a local repository that will host such libraries. There are a number of projects that do exactly that. For example Artifactory.

How to SELECT by MAX(date)?

Are you only wanting it to show the last date_entered, or to order by starting with the last_date entered?

SELECT report_id, computer_id, date_entered
FROM reports
GROUP BY computer_id
ORDER BY date_entered DESC
-- LIMIT 1 -- uncomment to only show the last date.

What do the different readystates in XMLHttpRequest mean, and how can I use them?

kieron's answer contains w3schools ref. to which nobody rely , bobince's answer gives link , which actually tells native implementation of IE ,

so here is the original documentation quoted to rightly understand what readystate represents :

The XMLHttpRequest object can be in several states. The readyState attribute must return the current state, which must be one of the following values:

UNSENT (numeric value 0)
The object has been constructed.

OPENED (numeric value 1)
The open() method has been successfully invoked. During this state request headers can be set using setRequestHeader() and the request can be made using the send() method.

HEADERS_RECEIVED (numeric value 2)
All redirects (if any) have been followed and all HTTP headers of the final response have been received. Several response members of the object are now available.

LOADING (numeric value 3)
The response entity body is being received.

DONE (numeric value 4)
The data transfer has been completed or something went wrong during the transfer (e.g. infinite redirects).

Please Read here : W3C Explaination Of ReadyState

MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?

sometimes when data grow bigger mysql WHERE IN's could be pretty slow because of query optimization. Try using STRAIGHT_JOIN to tell mysql to execute query as is, e.g.

SELECT STRAIGHT_JOIN table.field FROM table WHERE table.id IN (...)

but beware: in most cases mysql optimizer works pretty well, so I would recommend to use it only when you have this kind of problem

How do I set <table> border width with CSS?

<table style='border:1px solid black'>
    <tr>
        <td>Derp</td>
    </tr>
</table>

This should work. I use the shorthand syntax for borders.

The specified child already has a parent. You must call removeView() on the child's parent first

In my case I was accidentally returning a child view from within Layout.onCreateView() as shown below:

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_reject, container, false);

    Button button = view.findViewById(R.id.some_button);

    return button; // <-- Problem is this
}

The solution was to return the parent view instead of the child view.

React navigation goBack() and update parent state

I was facing a similar issue, so here is how I solved it by going more into details.

Option one is to navigate back to parent with parameters, just define a callback function in it like this in parent component:

updateData = data => {
  console.log(data);
  alert("come back status: " + data);
  // some other stuff
};

and navigate to the child:

onPress = () => {
  this.props.navigation.navigate("ParentScreen", {
    name: "from parent",
    updateData: this.updateData
  });
};

Now in the child it can be called:

 this.props.navigation.state.params.updateData(status);
 this.props.navigation.goBack();

Option two. In order to get data from any component, as the other answer explained, AsyncStorage can be used either synchronously or not.

Once data is saved it can be used anywhere.

// to get
AsyncStorage.getItem("@item")
  .then(item => {
    item = JSON.parse(item);
    this.setState({ mystate: item });
  })
  .done();
// to set
AsyncStorage.setItem("@item", JSON.stringify(someData));

or either use an async function to make it self-update when it gets new value doing like so.

this.state = { item: this.dataUpdate() };
async function dataUpdate() {
  try {
    let item = await AsyncStorage.getItem("@item");
    return item;
  } catch (e) {
    console.log(e.message);
  }
}

See the AsyncStorage docs for more details.

Are PDO prepared statements sufficient to prevent SQL injection?

Personally I would always run some form of sanitation on the data first as you can never trust user input, however when using placeholders / parameter binding the inputted data is sent to the server separately to the sql statement and then binded together. The key here is that this binds the provided data to a specific type and a specific use and eliminates any opportunity to change the logic of the SQL statement.

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

In case this is useful to anyone I had this same issue. I was bringing in a footer into a web page via jQuery. Inside that footer were some Google scripts for ads and retargeting. I had to move those scripts from the footer and place them directly in the page and that eliminated the notice.

PHP - Notice: Undefined index:

How are you loading this page? Is it getting anything on POST to load? If it's not, then the $name = $_POST['Name']; assignation doesn't have any 'Name' on POST.

How to change letter spacing in a Textview?

For embedding HTML text in your textview you can use Html.fromHTML() syntax. More information you will get from http://developer.android.com/reference/android/text/Html.html#fromHtml%28java.lang.String%29

How to convert List<Integer> to int[] in Java?

I'll throw one more in here. I've noticed several uses of for loops, but you don't even need anything inside the loop. I mention this only because the original question was trying to find less verbose code.

int[] toArray(List<Integer> list) {
    int[] ret = new int[ list.size() ];
    int i = 0;
    for( Iterator<Integer> it = list.iterator(); 
         it.hasNext(); 
         ret[i++] = it.next() );
    return ret;
}

If Java allowed multiple declarations in a for loop the way C++ does, we could go a step further and do for(int i = 0, Iterator it...

In the end though (this part is just my opinion), if you are going to have a helping function or method to do something for you, just set it up and forget about it. It can be a one-liner or ten; if you'll never look at it again you won't know the difference.

How to send data in request body with a GET when using jQuery $.ajax()

Just in case somebody ist still coming along this question:

There is a body query object in any request. You do not need to parse it yourself.

E.g. if you want to send an accessToken from a client with GET, you could do it like this:

_x000D_
_x000D_
const request = require('superagent');_x000D_
_x000D_
request.get(`http://localhost:3000/download?accessToken=${accessToken}`).end((err, res) => {_x000D_
  if (err) throw new Error(err);_x000D_
  console.log(res);_x000D_
});
_x000D_
_x000D_
_x000D_

The server request object then looks like {request: { ... query: { accessToken: abcfed } ... } }

public static const in TypeScript

You can use a getter, so that your property is going to be reading only. Example:

export class MyClass {
    private _LEVELS = {
        level1: "level1",
        level2: "level2",
        level2: "level2"
    };

    public get STATUSES() {
        return this._LEVELS;
    }
}

Used in another class:

import { MyClass } from "myclasspath";
class AnotherClass {
    private myClass = new MyClass();

    tryLevel() {
       console.log(this.myClass.STATUSES.level1);
    }
}

Django URLs TypeError: view must be a callable or a list/tuple in the case of include()

Your code is

urlpatterns = [
    url(r'^$', 'myapp.views.home'),
    url(r'^contact/$', 'myapp.views.contact'),
    url(r'^login/$', 'django.contrib.auth.views.login'),
]

change it to following as you're importing include() function :

urlpatterns = [
    url(r'^$', views.home),
    url(r'^contact/$', views.contact),
    url(r'^login/$', views.login),
]

Convert Mat to Array/Vector in OpenCV

You can use iterators:

Mat matrix = ...;

std::vector<float> vec(matrix.begin<float>(), matrix.end<float>());

HTML - Alert Box when loading page

Yes you need javascript. The simplest way is to just put this at the bottom of your HTML page:

<script type="text/javascript">
alert("Hello world");
</script>

There are more preferred methods, like using jQuery's ready function, but this method will work.

Python Pandas counting and summing specific conditions

You can first make a conditional selection, and sum up the results of the selection using the sum function.

>> df = pd.DataFrame({'a': [1, 2, 3]})
>> df[df.a > 1].sum()   
a    5
dtype: int64

Having more than one condition:

>> df[(df.a > 1) & (df.a < 3)].sum()
a    2
dtype: int64

How do I move a file from one location to another in Java?

File.renameTo from Java IO can be used to move a file in Java. Also see this SO question.

What's the difference between all the Selection Segues?

For those who prefer a bit more practical learning, select the segue in dock, open the attribute inspector and switch between different kinds of segues (dropdown "Kind"). This will reveal options specific for each of them: for example you can see that "present modally" allows you to choose a transition type etc.

Laravel password validation rule

Sounds like a good job for regular expressions.

Laravel validation rules support regular expressions. Both 4.X and 5.X versions are supporting it :

This might help too:

http://www.regular-expressions.info/unicode.html

CSS force new line

Use <br /> OR <br> -

<li>Post by<br /><a>Author</a></li>

OR

<li>Post by<br><a>Author</a></li>

or

make the a element display:block;

<li>Post by <a style="display:block;">Author</a></li>

Try

Where's the IE7/8/9/10-emulator in IE11 dev tools?

I posted an answer to this already when someone else asked the same question (see How to bring back "Browser mode" in IE11?).

Read my answer there for a fuller explaination, but in short:

  • They removed it deliberately, because compat mode is not actually really very good for testing compatibility.

  • If you really want to test for compatibility with any given version of IE, you need to test in a real copy of that IE version. MS provide free VMs on http://modern.ie/ for you to use for this purpose.

  • The only way to get compat mode in IE11 is to set the X-UA-Compatible header. When you have this and the site defaults to compat mode, you will be able to set the mode in dev tools, but only between edge or the specified compat mode; other modes will still not be available.

Email address validation in C# MVC 4 application: with or without using Regex

Don't.

Use a regex for a quick sanity check, something like .@.., but almost all langauges / frameworks have better methods for checking an e-mail address. Use that.

It is possible to validate an e-mail address with a regex, but it is a long regex. Very long.
And in the end you will be none the wiser. You'll only know that the format is valid, but you still don't know if it's an active e-mail address. The only way to find out, is by sending a confirmation e-mail.

What is the difference between user and kernel modes in operating systems?

CPU rings are the most clear distinction

In x86 protected mode, the CPU is always in one of 4 rings. The Linux kernel only uses 0 and 3:

  • 0 for kernel
  • 3 for users

This is the most hard and fast definition of kernel vs userland.

Why Linux does not use rings 1 and 2: CPU Privilege Rings: Why rings 1 and 2 aren't used?

How is the current ring determined?

The current ring is selected by a combination of:

  • global descriptor table: a in-memory table of GDT entries, and each entry has a field Privl which encodes the ring.

    The LGDT instruction sets the address to the current descriptor table.

    See also: http://wiki.osdev.org/Global_Descriptor_Table

  • the segment registers CS, DS, etc., which point to the index of an entry in the GDT.

    For example, CS = 0 means the first entry of the GDT is currently active for the executing code.

What can each ring do?

The CPU chip is physically built so that:

  • ring 0 can do anything

  • ring 3 cannot run several instructions and write to several registers, most notably:

    • cannot change its own ring! Otherwise, it could set itself to ring 0 and rings would be useless.

      In other words, cannot modify the current segment descriptor, which determines the current ring.

    • cannot modify the page tables: How does x86 paging work?

      In other words, cannot modify the CR3 register, and paging itself prevents modification of the page tables.

      This prevents one process from seeing the memory of other processes for security / ease of programming reasons.

    • cannot register interrupt handlers. Those are configured by writing to memory locations, which is also prevented by paging.

      Handlers run in ring 0, and would break the security model.

      In other words, cannot use the LGDT and LIDT instructions.

    • cannot do IO instructions like in and out, and thus have arbitrary hardware accesses.

      Otherwise, for example, file permissions would be useless if any program could directly read from disk.

      More precisely thanks to Michael Petch: it is actually possible for the OS to allow IO instructions on ring 3, this is actually controlled by the Task state segment.

      What is not possible is for ring 3 to give itself permission to do so if it didn't have it in the first place.

      Linux always disallows it. See also: Why doesn't Linux use the hardware context switch via the TSS?

How do programs and operating systems transition between rings?

  • when the CPU is turned on, it starts running the initial program in ring 0 (well kind of, but it is a good approximation). You can think this initial program as being the kernel (but it is normally a bootloader that then calls the kernel still in ring 0).

  • when a userland process wants the kernel to do something for it like write to a file, it uses an instruction that generates an interrupt such as int 0x80 or syscall to signal the kernel. x86-64 Linux syscall hello world example:

    .data
    hello_world:
        .ascii "hello world\n"
        hello_world_len = . - hello_world
    .text
    .global _start
    _start:
        /* write */
        mov $1, %rax
        mov $1, %rdi
        mov $hello_world, %rsi
        mov $hello_world_len, %rdx
        syscall
    
        /* exit */
        mov $60, %rax
        mov $0, %rdi
        syscall
    

    compile and run:

    as -o hello_world.o hello_world.S
    ld -o hello_world.out hello_world.o
    ./hello_world.out
    

    GitHub upstream.

    When this happens, the CPU calls an interrupt callback handler which the kernel registered at boot time. Here is a concrete baremetal example that registers a handler and uses it.

    This handler runs in ring 0, which decides if the kernel will allow this action, do the action, and restart the userland program in ring 3. x86_64

  • when the exec system call is used (or when the kernel will start /init), the kernel prepares the registers and memory of the new userland process, then it jumps to the entry point and switches the CPU to ring 3

  • If the program tries to do something naughty like write to a forbidden register or memory address (because of paging), the CPU also calls some kernel callback handler in ring 0.

    But since the userland was naughty, the kernel might kill the process this time, or give it a warning with a signal.

  • When the kernel boots, it setups a hardware clock with some fixed frequency, which generates interrupts periodically.

    This hardware clock generates interrupts that run ring 0, and allow it to schedule which userland processes to wake up.

    This way, scheduling can happen even if the processes are not making any system calls.

What is the point of having multiple rings?

There are two major advantages of separating kernel and userland:

  • it is easier to make programs as you are more certain one won't interfere with the other. E.g., one userland process does not have to worry about overwriting the memory of another program because of paging, nor about putting hardware in an invalid state for another process.
  • it is more secure. E.g. file permissions and memory separation could prevent a hacking app from reading your bank data. This supposes, of course, that you trust the kernel.

How to play around with it?

I've created a bare metal setup that should be a good way to manipulate rings directly: https://github.com/cirosantilli/x86-bare-metal-examples

I didn't have the patience to make a userland example unfortunately, but I did go as far as paging setup, so userland should be feasible. I'd love to see a pull request.

Alternatively, Linux kernel modules run in ring 0, so you can use them to try out privileged operations, e.g. read the control registers: How to access the control registers cr0,cr2,cr3 from a program? Getting segmentation fault

Here is a convenient QEMU + Buildroot setup to try it out without killing your host.

The downside of kernel modules is that other kthreads are running and could interfere with your experiments. But in theory you can take over all interrupt handlers with your kernel module and own the system, that would be an interesting project actually.

Negative rings

While negative rings are not actually referenced in the Intel manual, there are actually CPU modes which have further capabilities than ring 0 itself, and so are a good fit for the "negative ring" name.

One example is the hypervisor mode used in virtualization.

For further details see:

ARM

In ARM, the rings are called Exception Levels instead, but the main ideas remain the same.

There exist 4 exception levels in ARMv8, commonly used as:

  • EL0: userland

  • EL1: kernel ("supervisor" in ARM terminology).

    Entered with the svc instruction (SuperVisor Call), previously known as swi before unified assembly, which is the instruction used to make Linux system calls. Hello world ARMv8 example:

    hello.S

    .text
    .global _start
    _start:
        /* write */
        mov x0, 1
        ldr x1, =msg
        ldr x2, =len
        mov x8, 64
        svc 0
    
        /* exit */
        mov x0, 0
        mov x8, 93
        svc 0
    msg:
        .ascii "hello syscall v8\n"
    len = . - msg
    

    GitHub upstream.

    Test it out with QEMU on Ubuntu 16.04:

    sudo apt-get install qemu-user gcc-arm-linux-gnueabihf
    arm-linux-gnueabihf-as -o hello.o hello.S
    arm-linux-gnueabihf-ld -o hello hello.o
    qemu-arm hello
    

    Here is a concrete baremetal example that registers an SVC handler and does an SVC call.

  • EL2: hypervisors, for example Xen.

    Entered with the hvc instruction (HyperVisor Call).

    A hypervisor is to an OS, what an OS is to userland.

    For example, Xen allows you to run multiple OSes such as Linux or Windows on the same system at the same time, and it isolates the OSes from one another for security and ease of debug, just like Linux does for userland programs.

    Hypervisors are a key part of today's cloud infrastructure: they allow multiple servers to run on a single hardware, keeping hardware usage always close to 100% and saving a lot of money.

    AWS for example used Xen until 2017 when its move to KVM made the news.

  • EL3: yet another level. TODO example.

    Entered with the smc instruction (Secure Mode Call)

The ARMv8 Architecture Reference Model DDI 0487C.a - Chapter D1 - The AArch64 System Level Programmer's Model - Figure D1-1 illustrates this beautifully:

enter image description here

The ARM situation changed a bit with the advent of ARMv8.1 Virtualization Host Extensions (VHE). This extension allows the kernel to run in EL2 efficiently:

enter image description here

VHE was created because in-Linux-kernel virtualization solutions such as KVM have gained ground over Xen (see e.g. AWS' move to KVM mentioned above), because most clients only need Linux VMs, and as you can imagine, being all in a single project, KVM is simpler and potentially more efficient than Xen. So now the host Linux kernel acts as the hypervisor in those cases.

Note how ARM, maybe due to the benefit of hindsight, has a better naming convention for the privilege levels than x86, without the need for negative levels: 0 being the lower and 3 highest. Higher levels tend to be created more often than lower ones.

The current EL can be queried with the MRS instruction: what is the current execution mode/exception level, etc?

ARM does not require all exception levels to be present to allow for implementations that don't need the feature to save chip area. ARMv8 "Exception levels" says:

An implementation might not include all of the Exception levels. All implementations must include EL0 and EL1. EL2 and EL3 are optional.

QEMU for example defaults to EL1, but EL2 and EL3 can be enabled with command line options: qemu-system-aarch64 entering el1 when emulating a53 power up

Code snippets tested on Ubuntu 18.10.

Java: Converting String to and from ByteBuffer and associated problems

Unless things have changed, you're better off with

public static ByteBuffer str_to_bb(String msg, Charset charset){
    return ByteBuffer.wrap(msg.getBytes(charset));
}

public static String bb_to_str(ByteBuffer buffer, Charset charset){
    byte[] bytes;
    if(buffer.hasArray()) {
        bytes = buffer.array();
    } else {
        bytes = new byte[buffer.remaining()];
        buffer.get(bytes);
    }
    return new String(bytes, charset);
}

Usually buffer.hasArray() will be either always true or always false depending on your use case. In practice, unless you really want it to work under any circumstances, it's safe to optimize away the branch you don't need.

How to commit my current changes to a different branch in Git

You can just create a new branch and switch onto it. Commit your changes then:

git branch dirty
git checkout dirty
// And your commit follows ...

Alternatively, you can also checkout an existing branch (just git checkout <name>). But only, if there are no collisions (the base of all edited files is the same as in your current branch). Otherwise you will get a message.

jQuery validation plugin: accept only alphabetical characters?

Both Nick and Adam's answers work really well.

I'd like to add a note if you want to allow latin characters like á and ç as I wanted to do:

jQuery.validator.addMethod('lettersonly', function(value, element) {
    return this.optional(element) || /^[a-z áãâäàéêëèíîïìóõôöòúûüùçñ]+$/i.test(value);
}, "Letters and spaces only please");

Can HTTP POST be limitless?

EDIT (2019) This answer is now pretty redundant but there is another answer with more relevant information.

It rather depends on the web server and web browser:

Internet explorer All versions 2GB-1
Mozilla Firefox All versions 2GB-1
IIS 1-5 2GB-1
IIS 6 4GB-1

Although IIS only support 200KB by default, the metabase needs amending to increase this.

http://www.motobit.com/help/scptutl/pa98.htm

The POST method itself does not have any limit on the size of data.

Can't concat bytes to str

You can convert type of plaintext to string:

f.write(str(plaintext) + '\n')

How do I run git log to see changes only for a specific branch?

For those using Magit, hit l and =m to toggle --no-merges and =pto toggle --first-parent.

Then either just hit l again to show commits from the current branch (with none of commits merged onto it) down to end of history, or, if you want the log to end where it was branched off from master, hit o and type master.. as your range:

enter image description here

What does @media screen and (max-width: 1024px) mean in CSS?

It targets some specified feature to execute some other codes...

For example:

@media all and (max-width: 600px) {
  .navigation {
    -webkit-flex-flow: column wrap;
    flex-flow: column wrap;
    padding: 0;

  }

the above snippet say if the device that run this program have screen with 600px or less than 600px width, in this case our program must execute this part .

Format telephone and credit card numbers in AngularJS

Simple filter something like this (use numeric class on input end filter charchter in []):

<script type="text/javascript">
// Only allow number input
$('.numeric').keyup(function () {
    this.value = this.value.replace(/[^0-9+-\.\,\;\:\s()]/g, ''); // this is filter for telefon number !!!
});

Convert LocalDateTime to LocalDateTime in UTC

Here's a simple little utility class that you can use to convert local date times from zone to zone, including a utility method directly to convert a local date time from the current zone to UTC (with main method so you can run it and see the results of a simple test):

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;

public final class DateTimeUtil {
    private DateTimeUtil() {
        super();
    }

    public static void main(final String... args) {
        final LocalDateTime now = LocalDateTime.now();
        final LocalDateTime utc = DateTimeUtil.toUtc(now);

        System.out.println("Now: " + now);
        System.out.println("UTC: " + utc);
    }

    public static LocalDateTime toZone(final LocalDateTime time, final ZoneId fromZone, final ZoneId toZone) {
        final ZonedDateTime zonedtime = time.atZone(fromZone);
        final ZonedDateTime converted = zonedtime.withZoneSameInstant(toZone);
        return converted.toLocalDateTime();
    }

    public static LocalDateTime toZone(final LocalDateTime time, final ZoneId toZone) {
        return DateTimeUtil.toZone(time, ZoneId.systemDefault(), toZone);
    }

    public static LocalDateTime toUtc(final LocalDateTime time, final ZoneId fromZone) {
        return DateTimeUtil.toZone(time, fromZone, ZoneOffset.UTC);
    }

    public static LocalDateTime toUtc(final LocalDateTime time) {
        return DateTimeUtil.toUtc(time, ZoneId.systemDefault());
    }
}

Simple WPF RadioButton Binding?

Sometimes it is possible to solve it in the model like this: Suppose you have 3 boolean properties OptionA, OptionB, OptionC.

XAML:

<RadioButton IsChecked="{Binding OptionA}"/>
<RadioButton IsChecked="{Binding OptionB}"/>
<RadioButton IsChecked="{Binding OptionC}"/>

CODE:

private bool _optionA;
public bool OptionA
{
    get { return _optionA; }
    set
    {
        _optionA = value;
        if( _optionA )
        {
             this.OptionB= false;
             this.OptionC = false;
        }
    }
}

private bool _optionB;
public bool OptionB
{
    get { return _optionB; }
    set
    {
        _optionB = value;
        if( _optionB )
        {
            this.OptionA= false;
            this.OptionC = false;
        }
    }
}

private bool _optionC;
public bool OptionC
{
    get { return _optionC; }
    set
    {
        _optionC = value;
        if( _optionC )
        {
            this.OptionA= false;
            this.OptionB = false;
        }
    }
}

You get the idea. Not the cleanest thing, but easy.

Get IP address of visitors using Flask for Python

This should do the job. It provides the client IP address (remote host).

Note that this code is running on the server side.

from mod_python import apache

req.get_remote_host(apache.REMOTE_NOLOOKUP)

Using GCC to produce readable assembly?

Use the -S (note: capital S) switch to GCC, and it will emit the assembly code to a file with a .s extension. For example, the following command:

gcc -O2 -S -c foo.c

How to deploy a React App on Apache web server

  1. Go to your project root directory cd example /home/ubuntu/react-js
  2. Build your project first npm run build
  3. check your build directory gracefully all the files will be available in the build folder.

    asset-manifest.json

    favicon.ico

    manifest.json

    robots.txt

    static assets

    index.html

    precache-manifest.ddafca92870314adfea99542e1331500.js service-worker.js

4.copy the build folder to your apache server i.e /var/www/html

sudo cp -rf build /var/www/html
  1. go to sites-available directory

    cd /etc/apache2/sites-available/

  2. open 000-default.conf file

    sudo vi 000-default.conf and rechange the DocumentRoot path

    enter image description here

  3. Now goto apache conf.

    cd /etc/aapche2

    sudo vi apache2.conf

    add the given snippet

_x000D_
_x000D_
<Directory /var/www/html>_x000D_
_x000D_
            Options Indexes FollowSymLinks_x000D_
_x000D_
            AllowOverride All_x000D_
_x000D_
            Require all granted_x000D_
_x000D_
    </Directory>
_x000D_
_x000D_
_x000D_

  1. make a file inside /var/www/html/build

    sudo vi .htaccess

_x000D_
_x000D_
Options -MultiViews_x000D_
    _x000D_
RewriteEngine On_x000D_
    _x000D_
RewriteCond %{REQUEST_FILENAME} !-f_x000D_
_x000D_
RewriteRule ^ index.html [QSA,L]
_x000D_
_x000D_
_x000D_

9.sudo a2enmod rewrite

10.sudo systemctl restart apache2

  1. restart apache server

    sudo service apache2 restart

    thanks, enjoy your day

Get an object attribute

Use getattr if you have an attribute in string form:

>>> class User(object):
       name = 'John'

>>> u = User()
>>> param = 'name'
>>> getattr(u, param)
'John'

Otherwise use the dot .:

>>> class User(object):
       name = 'John'

>>> u = User()
>>> u.name
'John'

DateTimePicker time picker in 24 hour but displaying in 12hr?

You can also use the parameters "use24hours" and "language" to do this, as follows:

_x000D_
_x000D_
$(function () {_x000D_
    $('.datetime').datetimepicker({_x000D_
        language: 'pt-br',_x000D_
        use24hours: true,_x000D_
    });_x000D_
});
_x000D_
_x000D_
_x000D_

CentOS: Copy directory to another directory

As I understand, you want to recursively copy test directory into /home/server/ path...

This can be done as:

-cp -rf /home/server/folder/test/* /home/server/

Hope this helps

How to repeat last command in python interpreter shell?

Ipython isn't allways the way... I like it pretty much, but if you try run Django shell with ipython. Something like>>>

ipython manage.py shell

it does'n work correctly if you use virtualenv. Django needs some special includes which aren't there if you start ipython, because it starts default system python, but not that virtual.

How to correctly get image from 'Resources' folder in NetBeans

For me it worked like I had images in icons folder under src and I wrote below code.

new ImageIcon(getClass().getResource("/icons/rsz_measurment_01.png"));

Create a git patch from the uncommitted changes in the current working directory

git diff for unstaged changes.

git diff --cached for staged changes.

git diff HEAD for both staged and unstaged changes.

When to use @QueryParam vs @PathParam

As theon noted, REST is not a standard. However, if you are looking to implement a standards based URI convention, you might consider the oData URI convention. Ver 4 has been approved as an OASIS standard and libraries exists for oData for various languages including Java via Apache Olingo. Don't let the fact that it's a spawn from Microsoft put you off since it's gained support from other industry player's as well, which include Red Hat, Citrix, IBM, Blackberry, Drupal, Netflix Facebook and SAP

More adopters are listed here

What equivalents are there to TortoiseSVN, on Mac OSX?

My previous version of this answer had links, that kept becoming dead.
So, I've pointed it to the internet archive to preserve the original answer.

Subversion client releases for Windows and Macintosh

Wiki - Subversion clients comparison table

jquery find element by specific class when element has multiple classes

you are looking for http://api.jquery.com/hasClass/

<div id="mydiv" class="foo bar"></div>

$('#mydiv').hasClass('foo') //returns ture

SQL RANK() versus ROW_NUMBER()

This article covers an interesting relationship between ROW_NUMBER() and DENSE_RANK() (the RANK() function is not treated specifically). When you need a generated ROW_NUMBER() on a SELECT DISTINCT statement, the ROW_NUMBER() will produce distinct values before they are removed by the DISTINCT keyword. E.g. this query

SELECT DISTINCT
  v, 
  ROW_NUMBER() OVER (ORDER BY v) row_number
FROM t
ORDER BY v, row_number

... might produce this result (DISTINCT has no effect):

+---+------------+
| V | ROW_NUMBER |
+---+------------+
| a |          1 |
| a |          2 |
| a |          3 |
| b |          4 |
| c |          5 |
| c |          6 |
| d |          7 |
| e |          8 |
+---+------------+

Whereas this query:

SELECT DISTINCT
  v, 
  DENSE_RANK() OVER (ORDER BY v) row_number
FROM t
ORDER BY v, row_number

... produces what you probably want in this case:

+---+------------+
| V | ROW_NUMBER |
+---+------------+
| a |          1 |
| b |          2 |
| c |          3 |
| d |          4 |
| e |          5 |
+---+------------+

Note that the ORDER BY clause of the DENSE_RANK() function will need all other columns from the SELECT DISTINCT clause to work properly.

The reason for this is that logically, window functions are calculated before DISTINCT is applied.

All three functions in comparison

Using PostgreSQL / Sybase / SQL standard syntax (WINDOW clause):

SELECT
  v,
  ROW_NUMBER() OVER (window) row_number,
  RANK()       OVER (window) rank,
  DENSE_RANK() OVER (window) dense_rank
FROM t
WINDOW window AS (ORDER BY v)
ORDER BY v

... you'll get:

+---+------------+------+------------+
| V | ROW_NUMBER | RANK | DENSE_RANK |
+---+------------+------+------------+
| a |          1 |    1 |          1 |
| a |          2 |    1 |          1 |
| a |          3 |    1 |          1 |
| b |          4 |    4 |          2 |
| c |          5 |    5 |          3 |
| c |          6 |    5 |          3 |
| d |          7 |    7 |          4 |
| e |          8 |    8 |          5 |
+---+------------+------+------------+

Improve SQL Server query performance on large tables

Simple Answer: NO. You cannot help ad hoc queries on a 238 column table with a 50% Fill Factor on the Clustered Index.

Detailed Answer:

As I have stated in other answers on this topic, Index design is both Art and Science and there are so many factors to consider that there are few, if any, hard and fast rules. You need to consider: the volume of DML operations vs SELECTs, disk subsystem, other indexes / triggers on the table, distribution of data within the table, are queries using SARGable WHERE conditions, and several other things that I can't even remember right now.

I can say that no help can be given for questions on this topic without an understanding of the Table itself, its indexes, triggers, etc. Now that you have posted the table definition (still waiting on the Indexes but the Table definition alone points to 99% of the issue) I can offer some suggestions.

First, if the table definition is accurate (238 columns, 50% Fill Factor) then you can pretty much ignore the rest of the answers / advice here ;-). Sorry to be less-than-political here, but seriously, it's a wild goose chase without knowing the specifics. And now that we see the table definition it becomes quite a bit clearer as to why a simple query would take so long, even when the test queries (Update #1) ran so quickly.

The main problem here (and in many poor-performance situations) is bad data modeling. 238 columns is not prohibited just like having 999 indexes is not prohibited, but it is also generally not very wise.

Recommendations:

  1. First, this table really needs to be remodeled. If this is a data warehouse table then maybe, but if not then these fields really need to be broken up into several tables which can all have the same PK. You would have a master record table and the child tables are just dependent info based on commonly associated attributes and the PK of those tables is the same as the PK of the master table and hence also FK to the master table. There will be a 1-to-1 relationship between master and all child tables.
  2. The use of ANSI_PADDING OFF is disturbing, not to mention inconsistent within the table due to the various column additions over time. Not sure if you can fix that now, but ideally you would always have ANSI_PADDING ON, or at the very least have the same setting across all ALTER TABLE statements.
  3. Consider creating 2 additional File Groups: Tables and Indexes. It is best not to put your stuff in PRIMARY as that is where SQL SERVER stores all of its data and meta-data about your objects. You create your Table and Clustered Index (as that is the data for the table) on [Tables] and all Non-Clustered indexes on [Indexes]
  4. Increase the Fill Factor from 50%. This low number is likely why your index space is larger than your data space. Doing an Index Rebuild will recreate the data pages with a max of 4k (out of the total 8k page size) used for your data so your table is spread out over a wide area.
  5. If most or all queries have "ER101_ORG_CODE" in the WHERE condition, then consider moving that to the leading column of the clustered index. Assuming that it is used more often than "ER101_ORD_NBR". If "ER101_ORD_NBR" is used more often then keep it. It just seems, assuming that the field names mean "OrganizationCode" and "OrderNumber", that "OrgCode" is a better grouping that might have multiple "OrderNumbers" within it.
  6. Minor point, but if "ER101_ORG_CODE" is always 2 characters, then use CHAR(2) instead of VARCHAR(2) as it will save a byte in the row header which tracks variable width sizes and adds up over millions of rows.
  7. As others here have mentioned, using SELECT * will hurt performance. Not only due to it requiring SQL Server to return all columns and hence be more likely to do a Clustered Index Scan regardless of your other indexes, but it also takes SQL Server time to go to the table definition and translate * into all of the column names. It should be slightly faster to specify all 238 column names in the SELECT list though that won't help the Scan issue. But do you ever really need all 238 columns at the same time anyway?

Good luck!

UPDATE
For the sake of completeness to the question "how to improve performance on a large table for ad-hoc queries", it should be noted that while it will not help for this specific case, IF someone is using SQL Server 2012 (or newer when that time comes) and IF the table is not being updated, then using Columnstore Indexes is an option. For more details on that new feature, look here: http://msdn.microsoft.com/en-us/library/gg492088.aspx (I believe these were made to be updateable starting in SQL Server 2014).

UPDATE 2
Additional considerations are:

  • Enable compression on the Clustered Index. This option became available in SQL Server 2008, but as an Enterprise Edition-only feature. However, as of SQL Server 2016 SP1, Data Compression was made available in all editions! Please see the MSDN page for Data Compression for details on Row and Page Compression.
  • If you cannot use Data Compression, or if it won't provide much benefit for a particular table, then IF you have a column of a fixed-length type (INT, BIGINT, TINYINT, SMALLINT, CHAR, NCHAR, BINARY, DATETIME, SMALLDATETIME, MONEY, etc) and well over 50% of the rows are NULL, then consider enabling the SPARSE option which became available in SQL Server 2008. Please see the MSDN page for Use Sparse Columns for details.

Where is Maven's settings.xml located on Mac OS?

It doesn't exist at first. You have to create it in your home folder, /Users/usename/.m2/ (or ~/.m2)

For example :

alt text

bootstrap 3 - how do I place the brand in the center of the navbar?

css:

.navbar-header {
    float: left;
    padding: 15px;
    text-align: center;
    width: 100%;
}
.navbar-brand {float:none;}

html:

<nav class="navbar navbar-default" role="navigation">
  <div class="navbar-header">
    <a class="navbar-brand" href="#">Brand</a>
  </div>
</nav>

What is the easiest way to install BLAS and LAPACK for scipy?

Using conda install scipy instead of pip solved the problem for me!

How to loop over files in directory and change path and add suffix to filename

Looks like you're trying to execute a windows file (.exe) Surely you ought to be using powershell. Anyway on a Linux bash shell a simple one-liner will suffice.

[/home/$] for filename in /Data/*.txt; do for i in {0..3}; do ./MyProgam.exe  Data/filenameLogs/$filename_log$i.txt; done done

Or in a bash

#!/bin/bash

for filename in /Data/*.txt; 
   do
     for i in {0..3}; 
       do ./MyProgam.exe Data/filename.txt Logs/$filename_log$i.txt; 
     done 
 done

RSA encryption and decryption in Python

PKCS#1 OAEP is an asymmetric cipher based on RSA and the OAEP padding

from Crypto.PublicKey import RSA
from Crypto import Random
from Crypto.Cipher import PKCS1_OAEP


def rsa_encrypt_decrypt():
    key = RSA.generate(2048)
    private_key = key.export_key('PEM')
    public_key = key.publickey().exportKey('PEM')
    message = input('plain text for RSA encryption and decryption:')
    message = str.encode(message)

    rsa_public_key = RSA.importKey(public_key)
    rsa_public_key = PKCS1_OAEP.new(rsa_public_key)
    encrypted_text = rsa_public_key.encrypt(message)
    #encrypted_text = b64encode(encrypted_text)

    print('your encrypted_text is : {}'.format(encrypted_text))


    rsa_private_key = RSA.importKey(private_key)
    rsa_private_key = PKCS1_OAEP.new(rsa_private_key)
    decrypted_text = rsa_private_key.decrypt(encrypted_text)

    print('your decrypted_text is : {}'.format(decrypted_text))

java.lang.IllegalStateException: Cannot (forward | sendRedirect | create session) after response has been committed

After return forward method you can simply do this:

return null;

It will break the current scope.

How to flip background image using CSS?

For what it's worth, for Gecko-based browsers you can't condition this thing off of :visited due to the resulting privacy leaks. See http://hacks.mozilla.org/2010/03/privacy-related-changes-coming-to-css-vistited/

Video 100% width and height

video {
  width: 100%    !important;
  height: auto   !important;
}

Take a look here http://css-tricks.com/NetMag/FluidWidthVideo/Article-FluidWidthVideo.php

Print Html template in Angular 2 (ng-print in Angular 2)

Print service

import { Injectable } from '@angular/core';

@Injectable()
export class PrintingService {

public print(printEl: HTMLElement) {
    let printContainer: HTMLElement = document.querySelector('#print-container');

    if (!printContainer) {
      printContainer = document.createElement('div');
      printContainer.id = 'print-container';
    } 

    printContainer.innerHTML = '';

    let elementCopy = printEl.cloneNode(true);
    printContainer.appendChild(elementCopy);
    document.body.appendChild(printContainer);

    window.print();
  }
}

?omponent that I want to print

@Component({
  selector: 'app-component',
  templateUrl: './component.component.html',
  styleUrls: ['./component.component.css'],
  encapsulation: ViewEncapsulation.None
})
export class MyComponent {
  @ViewChild('printEl') printEl: ElementRef;

  constructor(private printingService: PrintingService) {}

  public print(): void {
    this.printingService.print(this.printEl.nativeElement);
 }

}

Not the best choice, but works.

Order of execution of tests in TestNG

To address specific scenario in question:

@Test
public void Test1() {

}

@Test (dependsOnMethods={"Test1"})
public void Test2() {

}

@Test (dependsOnMethods={"Test2"})
public void Test3() {

}

When to use setAttribute vs .attribute= in JavaScript?

None of the previous answers are complete and most contain misinformation.

There are three ways of accessing the attributes of a DOM Element in JavaScript. All three work reliably in modern browsers as long as you understand how to utilize them.

1. element.attributes

Elements have a property attributes that returns a live NamedNodeMap of Attr objects. The indexes of this collection may be different among browsers. So, the order is not guaranteed. NamedNodeMap has methods for adding and removing attributes (getNamedItem and setNamedItem, respectively).

Notice that though XML is explicitly case sensitive, the DOM spec calls for string names to be normalized, so names passed to getNamedItem are effectively case insensitive.

Example Usage:

_x000D_
_x000D_
var div = document.getElementsByTagName('div')[0];_x000D_
_x000D_
//you can look up specific attributes_x000D_
var classAttr = div.attributes.getNamedItem('CLASS');_x000D_
document.write('attributes.getNamedItem() Name: ' + classAttr.name + ' Value: ' + classAttr.value + '<br>');_x000D_
_x000D_
//you can enumerate all defined attributes_x000D_
for(var i = 0; i < div.attributes.length; i++) {_x000D_
  var attr = div.attributes[i];_x000D_
  document.write('attributes[] Name: ' + attr.name + ' Value: ' + attr.value + '<br>');_x000D_
}_x000D_
_x000D_
//create custom attribute_x000D_
var customAttr = document.createAttribute('customTest');_x000D_
customAttr.value = '567';_x000D_
div.attributes.setNamedItem(customAttr);_x000D_
_x000D_
//retreive custom attribute_x000D_
customAttr = div.attributes.getNamedItem('customTest');_x000D_
document.write('attributes.getNamedItem() Name: ' + customAttr.name + ' Value: ' + customAttr.value + '<br>');
_x000D_
<div class="class1" id="main" data-test="stuff" nonStandard="1234"></div>
_x000D_
_x000D_
_x000D_

2. element.getAttribute & element.setAttribute

These methods exist directly on the Element without needing to access attributes and its methods but perform the same functions.

Again, notice that string name are case insensitive.

Example Usage:

_x000D_
_x000D_
var div = document.getElementsByTagName('div')[0];_x000D_
_x000D_
//get specific attributes_x000D_
document.write('Name: class Value: ' + div.getAttribute('class') + '<br>');_x000D_
document.write('Name: ID Value: ' + div.getAttribute('ID') + '<br>');_x000D_
document.write('Name: DATA-TEST Value: ' + div.getAttribute('DATA-TEST') + '<br>');_x000D_
document.write('Name: nonStandard Value: ' + div.getAttribute('nonStandard') + '<br>');_x000D_
_x000D_
_x000D_
//create custom attribute_x000D_
div.setAttribute('customTest', '567');_x000D_
_x000D_
//retreive custom attribute_x000D_
document.write('Name: customTest Value: ' + div.getAttribute('customTest') + '<br>');
_x000D_
<div class="class1" id="main" data-test="stuff" nonStandard="1234"></div>
_x000D_
_x000D_
_x000D_

3. Properties on the DOM object, such as element.id

Many attributes can be accessed using convenient properties on the DOM object. Which attributes exist depends on the DOM node's type, not which attributes are defined in the HTML. The properties are defined somewhere in the prototype chain of DOM object in question. The specific properties defined will depend on the type of Element you are accessing. For example, className and id are defined on Element and exist on all DOM nodes that are elements (ie. not text or comment nodes). But value is more narrow. It's defined on HTMLInputElement and may not exist on other elements.

Notice that JavaScript properties are case sensitive. Although most properties will use lowercase, some are camelCase. So always check the spec to be sure.

This "chart" captures a portion of the prototype chain for these DOM objects. It's not even close to complete, but it captures the overall structure.

                      ____________Node___________
                      |               |         |
                   Element           Text   Comment
                   |     |
           HTMLElement   SVGElement
           |         |
HTMLInputElement   HTMLSpanElement

Example Usage:

_x000D_
_x000D_
var div = document.getElementsByTagName('div')[0];_x000D_
_x000D_
//get specific attributes_x000D_
document.write('Name: class Value: ' + div.className + '<br>');_x000D_
document.write('Name: id Value: ' + div.id + '<br>');_x000D_
document.write('Name: ID Value: ' + div.ID + '<br>'); //undefined_x000D_
document.write('Name: data-test Value: ' + div.dataset.test + '<br>'); //.dataset is a special case_x000D_
document.write('Name: nonStandard Value: ' + div.nonStandard + '<br>'); //undefined
_x000D_
<div class="class1" id="main" data-test="stuff" nonStandard="1234"></div>
_x000D_
_x000D_
_x000D_

Caveat: This is an explanation of how the HTML spec defines and modern browsers handle attributes. I did not attempt to deal with limitations of ancient, broken browsers. If you need to support old browsers, in addition to this information, you will need to know what is broken in the those browsers.

jQuery: How can I create a simple overlay?

What do you intend to do with the overlay? If it's static, say, a simple box overlapping some content, just use absolute positioning with CSS. If it's dynamic (I believe this is called a lightbox), you can write some CSS-modifying jQuery code to show/hide the overlay on-demand.

Getting the count of unique values in a column in bash

The GNU site suggests this nice awk script, which prints both the words and their frequency.

Possible changes:

  • You can pipe through sort -nr (and reverse word and freq[word]) to see the result in descending order.
  • If you want a specific column, you can omit the for loop and simply write freq[3]++ - replace 3 with the column number.

Here goes:

 # wordfreq.awk --- print list of word frequencies

 {
     $0 = tolower($0)    # remove case distinctions
     # remove punctuation
     gsub(/[^[:alnum:]_[:blank:]]/, "", $0)
     for (i = 1; i <= NF; i++)
         freq[$i]++
 }

 END {
     for (word in freq)
         printf "%s\t%d\n", word, freq[word]
 }

Description for event id from source cannot be found

You need to create an event source and a message file for it. Code looks something like this:

var data = new EventSourceCreationData("yourApp", "Application");
data.MessageResourceFile = pathToYourMessageFile;
EventLog.CreateEventSource(data);

Then you will need to create a message file. There is also this article that explains things (I did not read it all but it seems fairly complete).

Oracle SQL: Update a table with data from another table

Here seems to be an even better answer with 'in' clause that allows for multiple keys for the join:

update fp_active set STATE='E', 
   LAST_DATE_MAJ = sysdate where (client,code) in (select (client,code) from fp_detail
  where valid = 1) ...

The full example is here: http://forums.devshed.com/oracle-development-96/how-to-update-from-two-tables-195893.html - from web archive since link was dead.

The beef is in having the columns that you want to use as the key in parentheses in the where clause before 'in' and have the select statement with the same column names in parentheses. where (column1,column2) in ( select (column1,column2) from table where "the set I want" );

How do I properly clean up Excel interop objects?

Excel is not designed to be programmed via C++ or C#. The COM API is specifically designed to work with Visual Basic, VB.NET, and VBA.

Also all the code samples on this page are not optimal for the simple reason that each call must cross a managed/unmanaged boundary and further ignore the fact that the Excel COM API is free to fail any call with a cryptic HRESULT indicating the RPC server is busy.

The best way to automate Excel in my opinion is to collect your data into as big an array as possible / feasible and send this across to a VBA function or sub (via Application.Run) which then performs any required processing. Furthermore - when calling Application.Run - be sure to watch for exceptions indicating excel is busy and retry calling Application.Run.

Creating the checkbox dynamically using JavaScript?

You're trying to put a text node inside an input element.

Input elements are empty and can't have children.

...
var checkbox = document.createElement('input');
checkbox.type = "checkbox";
checkbox.name = "name";
checkbox.value = "value";
checkbox.id = "id";

var label = document.createElement('label')
label.htmlFor = "id";
label.appendChild(document.createTextNode('text for label after checkbox'));

container.appendChild(checkbox);
container.appendChild(label);

How do I pass command-line arguments to a WinForms application?

Consider you need to develop a program through which you need to pass two arguments. First of all, you need to open Program.cs class and add arguments in the Main method as like below and pass these arguments to the constructor of the Windows form.

static class Program
{    
   [STAThread]
   static void Main(string[] args)
   {            
       Application.EnableVisualStyles();
       Application.SetCompatibleTextRenderingDefault(false);
       Application.Run(new Form1(args[0], Convert.ToInt32(args[1])));           
   }
}

In windows form class, add a parameterized constructor which accepts the input values from Program class as like below.

public Form1(string s, int i)
{
    if (s != null && i > 0)
       MessageBox.Show(s + " " + i);
}

To test this, you can open command prompt and go to the location where this exe is placed. Give the file name then parmeter1 parameter2. For example, see below

C:\MyApplication>Yourexename p10 5

From the C# code above, it will prompt a Messagebox with value p10 5.

How to join on multiple columns in Pyspark?

You should use & / | operators and be careful about operator precedence (== has lower precedence than bitwise AND and OR):

df1 = sqlContext.createDataFrame(
    [(1, "a", 2.0), (2, "b", 3.0), (3, "c", 3.0)],
    ("x1", "x2", "x3"))

df2 = sqlContext.createDataFrame(
    [(1, "f", -1.0), (2, "b", 0.0)], ("x1", "x2", "x3"))

df = df1.join(df2, (df1.x1 == df2.x1) & (df1.x2 == df2.x2))
df.show()

## +---+---+---+---+---+---+
## | x1| x2| x3| x1| x2| x3|
## +---+---+---+---+---+---+
## |  2|  b|3.0|  2|  b|0.0|
## +---+---+---+---+---+---+

Java: Convert String to TimeStamp

first convert your date string to date then convert it to timestamp by using following set of line

Date date=new Date();
Timestamp timestamp = new Timestamp(date.getTime());//instead of date put your converted date
Timestamp myTimeStamp= timestamp;

How to switch from POST to GET in PHP CURL

Make sure that you're putting your query string at the end of your URL when doing a GET request.

$qry_str = "?x=10&y=20";
$ch = curl_init();

// Set query data here with the URL
curl_setopt($ch, CURLOPT_URL, 'http://example.com/test.php' . $qry_str); 

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 3);
$content = trim(curl_exec($ch));
curl_close($ch);
print $content;
With a POST you pass the data via the CURLOPT_POSTFIELDS option instead 
of passing it in the CURLOPT__URL.
-------------------------------------------------------------------------

$qry_str = "x=10&y=20";
curl_setopt($ch, CURLOPT_URL, 'http://example.com/test.php');  
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 3);

// Set request method to POST
curl_setopt($ch, CURLOPT_POST, 1);

// Set query data here with CURLOPT_POSTFIELDS
curl_setopt($ch, CURLOPT_POSTFIELDS, $qry_str);

$content = trim(curl_exec($ch));
curl_close($ch);
print $content;

Note from the curl_setopt() docs for CURLOPT_HTTPGET (emphasis added):

[Set CURLOPT_HTTPGET equal to] TRUE to reset the HTTP request method to GET.
Since GET is the default, this is only necessary if the request method has been changed.

Bootstrap 4 img-circle class not working

Now the class is this

_x000D_
_x000D_
 <img src="img/img5.jpg" width="200px" class="rounded-circle float-right">
_x000D_
_x000D_
_x000D_

Get year, month or day from numpy datetime64

Use dates.tolist() to convert to native datetime objects, then simply access year. Example:

>>> dates = np.array(['2010-10-17', '2011-05-13', '2012-01-15'], dtype='datetime64')
>>> [x.year for x in dates.tolist()]
[2010, 2011, 2012]

This is basically the same idea exposed in https://stackoverflow.com/a/35281829/2192272, but using simpler syntax.

Tested with python 3.6 / numpy 1.18.

Using HttpClient and HttpPost in Android with post parameters

I've just checked and i have the same code as you and it works perferctly. The only difference is how i fill my List for the params :

I use a : ArrayList<BasicNameValuePair> params

and fill it this way :

 params.add(new BasicNameValuePair("apikey", apikey);

I do not use any JSONObject to send params to the webservices.

Are you obliged to use the JSONObject ?

Label word wrapping

Ironically, turning off AutoSize by setting it to false allowed me to get the label control dimensions to size it both vertically and horizontally which effectively allows word-wrapping to occur.

Best way to parseDouble with comma as decimal separator?

You of course need to use the correct locale. This question will help.

C# getting its own class name

Try this:

this.GetType().Name

Determining whether an object is a member of a collection in VBA

In your specific case (TableDefs) iterating over the collection and checking the Name is a good approach. This is OK because the key for the collection (Name) is a property of the class in the collection.

But in the general case of VBA collections, the key will not necessarily be part of the object in the collection (e.g. you could be using a Collection as a dictionary, with a key that has nothing to do with the object in the collection). In this case, you have no choice but to try accessing the item and catching the error.

Disable scrolling in an iPhone web application?

document.ontouchmove = function(e){ 
    e.preventDefault(); 
}

is actually the best choice i found out it allows you to still be able to tap on input fields as well as drag things using jQuery UI draggable but it stops the page from scrolling.

Django Model() vs Model.objects.create()

The two syntaxes are not equivalent and it can lead to unexpected errors. Here is a simple example showing the differences. If you have a model:

from django.db import models

class Test(models.Model):

    added = models.DateTimeField(auto_now_add=True)

And you create a first object:

foo = Test.objects.create(pk=1)

Then you try to create an object with the same primary key:

foo_duplicate = Test.objects.create(pk=1)
# returns the error:
# django.db.utils.IntegrityError: (1062, "Duplicate entry '1' for key 'PRIMARY'")

foo_duplicate = Test(pk=1).save()
# returns the error:
# django.db.utils.IntegrityError: (1048, "Column 'added' cannot be null")

GROUP BY without aggregate function

That's how GROUP BY works. It takes several rows and turns them into one row. Because of this, it has to know what to do with all the combined rows where there have different values for some columns (fields). This is why you have two options for every field you want to SELECT : Either include it in the GROUP BY clause, or use it in an aggregate function so the system knows how you want to combine the field.

For example, let's say you have this table:

Name | OrderNumber
------------------
John | 1
John | 2

If you say GROUP BY Name, how will it know which OrderNumber to show in the result? So you either include OrderNumber in group by, which will result in these two rows. Or, you use an aggregate function to show how to handle the OrderNumbers. For example, MAX(OrderNumber), which means the result is John | 2 or SUM(OrderNumber) which means the result is John | 3.

Escape quotes in JavaScript

You need to escape the string you are writing out into DoEdit to scrub out the double-quote characters. They are causing the onclick HTML attribute to close prematurely.

Using the JavaScript escape character, \, isn't sufficient in the HTML context. You need to replace the double-quote with the proper XML entity representation, &quot;.

How can I use modulo operator (%) in JavaScript?

It's the remainder operator and is used to get the remainder after integer division. Lots of languages have it. For example:

10 % 3 // = 1 ; because 3 * 3 gets you 9, and 10 - 9 is 1.

Apparently it is not the same as the modulo operator entirely.

How can I remove a pytz timezone from a datetime object?

To remove a timezone (tzinfo) from a datetime object:

# dt_tz is a datetime.datetime object
dt = dt_tz.replace(tzinfo=None)

If you are using a library like arrow, then you can remove timezone by simply converting an arrow object to to a datetime object, then doing the same thing as the example above.

# <Arrow [2014-10-09T10:56:09.347444-07:00]>
arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444, tzinfo=tzoffset(None, -25200))
tmpDatetime = arrowObj.datetime

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444)
tmpDatetime = tmpDatetime.replace(tzinfo=None)

Why would you do this? One example is that mysql does not support timezones with its DATETIME type. So using ORM's like sqlalchemy will simply remove the timezone when you give it a datetime.datetime object to insert into the database. The solution is to convert your datetime.datetime object to UTC (so everything in your database is UTC since it can't specify timezone) then either insert it into the database (where the timezone is removed anyway) or remove it yourself. Also note that you cannot compare datetime.datetime objects where one is timezone aware and another is timezone naive.

##############################################################################
# MySQL example! where MySQL doesn't support timezones with its DATETIME type!
##############################################################################

arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

arrowDt = arrowObj.to("utc").datetime

# inserts datetime.datetime(2014, 10, 9, 17, 56, 9, 347444, tzinfo=tzutc())
insertIntoMysqlDatabase(arrowDt)

# returns datetime.datetime(2014, 10, 9, 17, 56, 9, 347444)
dbDatetimeNoTz = getFromMysqlDatabase()

# cannot compare timzeone aware and timezone naive
dbDatetimeNoTz == arrowDt # False, or TypeError on python versions before 3.3

# compare datetimes that are both aware or both naive work however
dbDatetimeNoTz == arrowDt.replace(tzinfo=None) # True

How can I get around MySQL Errcode 13 with SELECT INTO OUTFILE?

Some things to try:

  • is the secure_file_priv system variable set? If it is, all files must be written to that directory.
  • ensure that the file does not exist - MySQL will only create new files, not overwrite existing ones.

Reason: no suitable image found

In my case, it was an issue with one of the pods I was using. I ended up removing that pod and placing the code from it into my project manually.

Laravel Eloquent LEFT JOIN WHERE NULL

use Illuminate\Database\Eloquent\Builder;

$query = Customers::with('orders');
$query = $query->whereHas('orders', function (Builder $query) use ($request) {
     $query = $query->where('orders.customer_id', 'NULL') 
});
    $query = $query->get();

Launch Bootstrap Modal on page load

You may want to keep jquery.js deferred for faster page load. However, if jquery.js is deferred the $(window).load may not work. Then you may try

setTimeout(function(){$('#myModal').modal('show');},3000);

it will popup your modal after page is completely loaded (including jquery)

passing form data to another HTML page

_x000D_
_x000D_
<form action="display.html" method="post">_x000D_
    <input type="text" name="serialNumber" />_x000D_
    <input type="submit" value="Submit" />_x000D_
</form>
_x000D_
_x000D_
_x000D_

In display.html you should add the following code.

<script>
function getParameterByName(name, url) {
    if (!url) url = window.location.href;
    name = name.replace(/[\[\]]/g, '\\$&');
    var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)'),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, ' '));
}

var sn = getParameterByName('serialNumber');

document.getElementById("write").innerHTML = sn;

</script>

How to use stringstream to separate comma separated strings

#include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main()
{
    std::string input = "abc,def,   ghi";
    std::istringstream ss(input);
    std::string token;
    size_t pos=-1;
    while(ss>>token) {
      while ((pos=token.rfind(',')) != std::string::npos) {
        token.erase(pos, 1);
      }
      std::cout << token << '\n';
    }
}

How can I change the thickness of my <hr> tag

Sub-pixel rendering in browsers

Sub-pixel rendering is tricky. You can't actually expect a monitor to render a less than a pixel thin line. But it's possible to provide sub-pixel dimensions. Depending on the browser they render these differently. Check this John Resig's blog post about it.

Basically if your monitor is an LCD and you're drawing vertical lines, you can easily draw a 1/3 pixel line. If your background is white, give your line colour of #f0f. To the eye this line will be 1/3 of pixel wide. Although it will be of some colour, if you'd magnify monitor, you'd see that only one segment of the whole pixel (consisting of RGB) will be dark. This is pretty much technique that's used for fine type hinting i.e. ClearType.

But horizontal lines can only be a full pixel high. That's technology limitation of LCD monitors. CRTs were even more complicated with their triangular phosphors (unless they were aperture grille type ie. Sony Trinitron) but that's a different story.

Basically providing a sub-pixel dimension and expecting it to render that way is same as expecting an integer variable to store a number of 1.2034759349. If you understand this is impossible, you should understand that monitors aren't able to render sub-pixel dimensions.

Cross browser safe style

But the way horizontal rules that blend in are usually done using colours. So if your background is for instance white (#fff) you can always make your HR very light. Like #eee.

The cross browser safe style for very light horizontal rule would be:

hr
{
    background-color: #eee;
    border: 0 none;
    color: #eee;
    height: 1px;
}

And use a CSS file instead of in-line styles. They provide a central definition for the whole site not just a particular element. It makes maintainability much better.

Calculate number of hours between 2 dates in PHP

Carbon could also be a nice way to go.

From their website:

A simple PHP API extension for DateTime. http://carbon.nesbot.com/

Example:

use Carbon\Carbon;

//...

$day1 = Carbon::createFromFormat('Y-m-d H:i:s', '2006-04-12 12:30:00');
$day2 = Carbon::createFromFormat('Y-m-d H:i:s', '2006-04-14 11:30:00');

echo $day1->diffInHours($day2); // 47

//...

Carbon extends the DateTime class to inherit methods including diff(). It adds nice sugars like diffInHours, diffInMintutes, diffInSeconds e.t.c.

How do you read scanf until EOF in C?

You need to check the return value against EOF, not against 1.

Note that in your example, you also used two different variable names, words and word, only declared words, and didn't declare its length, which should be 16 to fit the 15 characters read in plus a NUL character.

convert iso date to milliseconds in javascript

Try this

_x000D_
_x000D_
var date = new Date("11/21/1987 16:00:00"); // some mock date_x000D_
var milliseconds = date.getTime(); _x000D_
// This will return you the number of milliseconds_x000D_
// elapsed from January 1, 1970 _x000D_
// if your date is less than that date, the value will be negative_x000D_
_x000D_
console.log(milliseconds);
_x000D_
_x000D_
_x000D_

EDIT

You've provided an ISO date. It is also accepted by the constructor of the Date object

_x000D_
_x000D_
var myDate = new Date("2012-02-10T13:19:11+0000");_x000D_
var result = myDate.getTime();_x000D_
console.log(result);
_x000D_
_x000D_
_x000D_

Edit

The best I've found is to get rid of the offset manually.

_x000D_
_x000D_
var myDate = new Date("2012-02-10T13:19:11+0000");_x000D_
var offset = myDate.getTimezoneOffset() * 60 * 1000;_x000D_
_x000D_
var withOffset = myDate.getTime();_x000D_
var withoutOffset = withOffset - offset;_x000D_
console.log(withOffset);_x000D_
console.log(withoutOffset);
_x000D_
_x000D_
_x000D_

Seems working. As far as problems with converting ISO string into the Date object you may refer to the links provided.

EDIT

Fixed the bug with incorrect conversion to milliseconds according to Prasad19sara's comment.

Move layouts up when soft keyboard is shown?

<activity name="ActivityName"
    android:windowSoftInputMode="adjustResize">
    ...
</activity>

Add NestedScrollView around layout which you want to scroll, this will perfectly work

git: How to ignore all present untracked files?

In case you are not on Unix like OS, this would work on Windows using PowerShell

git status --porcelain | ?{ $_ -match "^\?\? " }| %{$_ -replace "^\?\? ",""} | Add-Content .\.gitignore

However, .gitignore file has to have a new empty line, otherwise it will append text to the last line no matter if it has content.

This might be a better alternative:

$gi=gc .\.gitignore;$res=git status --porcelain|?{ $_ -match "^\?\? " }|%{ $_ -replace "^\?\? ", "" }; $res=$gi+$res; $res | Out-File .\.gitignore

gpg: no valid OpenPGP data found

gpg: no valid OpenPGP data found.

In this scenario, the message is a cryptic way of telling you that the download failed. Piping these two steps together is nice when it works, but it kind of breaks the error reporting -- especially when you use wget -q (or curl -s), because these suppress error messages from the download step.

There could be any number of reasons for the download failure. My case, which wasn't exactly listed so far, was that the proxy settings were lost when I called the enclosing script with sudo.

unable to remove file that really exists - fatal: pathspec ... did not match any files

Your file .idea/workspace.xml is not under git version control. You have either not added it yet (check git status/Untracked files) or ignored it (using .gitignore or .git/info/exclude files)

You can verify it using following git command, that lists all ignored files:

git ls-files --others -i --exclude-standard

how to get curl to output only http response body (json) and no other headers etc

You are specifying the -i option:

-i, --include

(HTTP) Include the HTTP-header in the output. The HTTP-header includes things like server-name, date of the document, HTTP-version and more...

Simply remove that option from your command line:

response=$(curl -sb -H "Accept: application/json" "http://host:8080/some/resource")

What is the @Html.DisplayFor syntax for?

Html.DisplayFor() will render the DisplayTemplate that matches the property's type.

If it can't find any, I suppose it invokes .ToString().


If you don't know about display templates, they're partial views that can be put in a DisplayTemplates folder inside the view folder associated to a controller.


Example:

If you create a view named String.cshtml inside the DisplayTemplates folder of your views folder (e.g Home, or Shared) with the following code:

@model string

@if (string.IsNullOrEmpty(Model)) {
   <strong>Null string</strong>
}
else {
   @Model
}

Then @Html.DisplayFor(model => model.Title) (assuming that Title is a string) will use the template and display <strong>Null string</strong> if the string is null, or empty.

in querySelector: how to get the first and get the last elements? what traversal order is used in the dom?

Example to get the last input element:

document.querySelector(".groups-container >div:last-child input")

How to destroy Fragment?

If you don't remove manually these fragments, they are still attached to the activity. Your activity is not destroyed so these fragments are too. To remove (so destroy) these fragments, you can call:

fragmentTransaction.remove(yourfragment).commit()

Hope it helps to you

Percentage Height HTML 5/CSS

Hi! In order to use percentage(%), you must define the % of it parent element. If you use body{height: 100%} it will not work because it parent have no percentage in height. In that case in order to work that body height you must add this in html{height:100%}

In other case to get rid of that defining parent percentage you can use

body{height:100vh}

vh stands for viewport height

I think it help

Resize a picture to fit a JLabel

public void selectImageAndResize(){    
    int returnVal = jFileChooser.showOpenDialog(this); //open jfilechooser
    if (returnVal == jFileChooser.APPROVE_OPTION) {    //select image
        File file = jFileChooser.getSelectedFile();    //get the image
        BufferedImage bi;
        try {
            //
            //transforms selected file to buffer
            //
            bi=ImageIO.read(file);  
            ImageIcon iconimage = new ImageIcon(bi);

            //
            //get image dimensions
            //
            BufferedImage bi2 = new BufferedImage(iconimage.getIconWidth(), iconimage.getIconHeight(), BufferedImage.TYPE_INT_ARGB); 
            Graphics g = bi.createGraphics();
            iconimage.paintIcon(null, g, 0,0);
            g.dispose();

            //
            //resize image according to jlabel
            //
            BufferedImage resizedimage=resize(bi,jLabel2.getWidth(), jLabel2.getHeight()); 
            ImageIcon resizedicon=new ImageIcon(resizedimage);
            jLabel2.setIcon(resizedicon);
        } catch (Exception ex) {
            System.out.println("problem accessing file"+file.getAbsolutePath());
        }
    }
    else {
        System.out.println("File access cancelled by user.");
    }
}

How to use mongoose findOne

Mongoose basically wraps mongodb's api to give you a pseudo relational db api so queries are not going to be exactly like mongodb queries. Mongoose findOne query returns a query object, not a document. You can either use a callback as the solution suggests or as of v4+ findOne returns a thenable so you can use .then or await/async to retrieve the document.

// thenables
Auth.findOne({nick: 'noname'}).then(err, result) {console.log(result)};
Auth.findOne({nick: 'noname'}).then(function (doc) {console.log(doc)});

// To use a full fledge promise you will need to use .exec()
var auth = Auth.findOne({nick: 'noname'}).exec();
auth.then(function (doc) {console.log(doc)});

// async/await
async function auth() {
  const doc = await Auth.findOne({nick: 'noname'}).exec();
  return doc;
}
auth();

See the docs if you would like to use a third party promise library.

Create Windows service from executable

You can check out my small free utility for service create\edit\delete operations. Here is create example:

Go to Service -> Modify -> Create

enter image description here

Executable file (google drive): [Download]

Source code: [Download]

Blog post: [BlogLink]

Service editor class: WinServiceUtils.cs

Swing/Java: How to use the getText and setText string properly

the getText method returns a String, while the setText receives a String, so you can write it like label1.setText(nameField.getText()); in your listener.