Programs & Examples On #File transfer

Is a generic term for the act of transmitting files over a computer network or the Internet.

SFTP file transfer using Java JSch

The most trivial way to upload a file over SFTP with JSch is:

JSch jsch = new JSch();
Session session = jsch.getSession(user, host);
session.setPassword(password);
session.connect();

ChannelSftp sftpChannel = (ChannelSftp) session.openChannel("sftp");
sftpChannel.connect();

sftpChannel.put("C:/source/local/path/file.zip", "/target/remote/path/file.zip");

Similarly for a download:

sftpChannel.get("/source/remote/path/file.zip", "C:/target/local/path/file.zip");

You may need to deal with UnknownHostKey exception.

Transfer files to/from session I'm logged in with PuTTY

In that way on windows pscp allows an upload directly (without any request for e.g. key-accepting):

pscp.exe -scp -pw 'my_pw' -v -i my.ppk -l root -batch -sshlog logfile19.txt -hostkey ba:2e:4d:12:68:82:19:a1:d2:22:bc:12:c2:1a:44:a7 hallo4.txt [email protected]:/srv/www/htdocs/xml_parser/hallo4.txt

scp from Linux to Windows

If you want to copy paste files from Unix to Windows and Windows to Unix just use filezilla with port 22.

rsync error: failed to set times on "/foo/bar": Operation not permitted

This error might also pop-up if you run the rsync process for files that are not recently modified in the source or destination...because it cant set the time for the recently modified files.

how to achieve transfer file between client and server using java socket

Reading quickly through the source it seems that you're not far off. The following link should help (I did something similar but for FTP). For a file send from server to client, you start off with a file instance and an array of bytes. You then read the File into the byte array and write the byte array to the OutputStream which corresponds with the InputStream on the client's side.

http://www.rgagnon.com/javadetails/java-0542.html

Edit: Here's a working ultra-minimalistic file sender and receiver. Make sure you understand what the code is doing on both sides.

package filesendtest;

import java.io.*;
import java.net.*;

class TCPServer {

    private final static String fileToSend = "C:\\test1.pdf";

    public static void main(String args[]) {

        while (true) {
            ServerSocket welcomeSocket = null;
            Socket connectionSocket = null;
            BufferedOutputStream outToClient = null;

            try {
                welcomeSocket = new ServerSocket(3248);
                connectionSocket = welcomeSocket.accept();
                outToClient = new BufferedOutputStream(connectionSocket.getOutputStream());
            } catch (IOException ex) {
                // Do exception handling
            }

            if (outToClient != null) {
                File myFile = new File( fileToSend );
                byte[] mybytearray = new byte[(int) myFile.length()];

                FileInputStream fis = null;

                try {
                    fis = new FileInputStream(myFile);
                } catch (FileNotFoundException ex) {
                    // Do exception handling
                }
                BufferedInputStream bis = new BufferedInputStream(fis);

                try {
                    bis.read(mybytearray, 0, mybytearray.length);
                    outToClient.write(mybytearray, 0, mybytearray.length);
                    outToClient.flush();
                    outToClient.close();
                    connectionSocket.close();

                    // File sent, exit the main method
                    return;
                } catch (IOException ex) {
                    // Do exception handling
                }
            }
        }
    }
}

package filesendtest;

import java.io.*;
import java.io.ByteArrayOutputStream;
import java.net.*;

class TCPClient {

    private final static String serverIP = "127.0.0.1";
    private final static int serverPort = 3248;
    private final static String fileOutput = "C:\\testout.pdf";

    public static void main(String args[]) {
        byte[] aByte = new byte[1];
        int bytesRead;

        Socket clientSocket = null;
        InputStream is = null;

        try {
            clientSocket = new Socket( serverIP , serverPort );
            is = clientSocket.getInputStream();
        } catch (IOException ex) {
            // Do exception handling
        }

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        if (is != null) {

            FileOutputStream fos = null;
            BufferedOutputStream bos = null;
            try {
                fos = new FileOutputStream( fileOutput );
                bos = new BufferedOutputStream(fos);
                bytesRead = is.read(aByte, 0, aByte.length);

                do {
                        baos.write(aByte);
                        bytesRead = is.read(aByte);
                } while (bytesRead != -1);

                bos.write(baos.toByteArray());
                bos.flush();
                bos.close();
                clientSocket.close();
            } catch (IOException ex) {
                // Do exception handling
            }
        }
    }
}

Related

Byte array of unknown length in java

Edit: The following could be used to fingerprint small files before and after transfer (use SHA if you feel it's necessary):

public static String md5String(File file) {
    try {
        InputStream fin = new FileInputStream(file);
        java.security.MessageDigest md5er = MessageDigest.getInstance("MD5");
        byte[] buffer = new byte[1024];
        int read;
        do {
            read = fin.read(buffer);
            if (read > 0) {
                md5er.update(buffer, 0, read);
            }
        } while (read != -1);
        fin.close();
        byte[] digest = md5er.digest();
        if (digest == null) {
            return null;
        }
        String strDigest = "0x";
        for (int i = 0; i < digest.length; i++) {
            strDigest += Integer.toString((digest[i] & 0xff)
                    + 0x100, 16).substring(1).toUpperCase();
        }
        return strDigest;
    } catch (Exception e) {
        return null;
    }
}

Comparing HTTP and FTP for transferring files

Here's a performance comparison of the two. HTTP is more responsive for request-response of small files, but FTP may be better for large files if tuned properly. FTP used to be generally considered faster. FTP requires a control channel and state be maintained besides the TCP state but HTTP does not. There are 6 packet transfers before data starts transferring in FTP but only 4 in HTTP.

I think a properly tuned TCP layer would have more effect on speed than the difference between application layer protocols. The Sun Blueprint Understanding Tuning TCP has details.

Heres another good comparison of individual characteristics of each protocol.

scp copy directory to another server with private key auth

Covert .ppk to id_rsa using tool PuttyGen, (http://mydailyfindingsit.blogspot.in/2015/08/create-keys-for-your-linux-machine.html) and

scp -C -i ./id_rsa -r /var/www/* [email protected]:/var/www

it should work !

Java: is there a map function?

Be very careful with Collections2.transform() from guava. That method's greatest advantage is also its greatest danger: its laziness.

Look at the documentation of Lists.transform(), which I believe applies also to Collections2.transform():

The function is applied lazily, invoked when needed. This is necessary for the returned list to be a view, but it means that the function will be applied many times for bulk operations like List.contains(java.lang.Object) and List.hashCode(). For this to perform well, function should be fast. To avoid lazy evaluation when the returned list doesn't need to be a view, copy the returned list into a new list of your choosing.

Also in the documentation of Collections2.transform() they mention you get a live view, that change in the source list affect the transformed list. This sort of behaviour can lead to difficult-to-track problems if the developer doesn't realize the way it works.

If you want a more classical "map", that will run once and once only, then you're better off with FluentIterable, also from Guava, which has an operation which is much more simple. Here is the google example for it:

FluentIterable
       .from(database.getClientList())
       .filter(activeInLastMonth())
       .transform(Functions.toStringFunction())
       .limit(10)
       .toList();

transform() here is the map method. It uses the same Function<> "callbacks" as Collections.transform(). The list you get back is read-only though, use copyInto() to get a read-write list.

Otherwise of course when java8 comes out with lambdas, this will be obsolete.

How to hide a div from code (c#)

one fast and simple way is to make the div as

<div runat="server" id="MyDiv"></div>

and on code behind you set MyDiv.Visible=false

What is %0|%0 and how does it work?

This is the Windows version of a fork bomb.

%0 is the name of the currently executing batch file. A batch file that contains just this line:

%0|%0

Is going to recursively execute itself forever, quickly creating many processes and slowing the system down.

This is not a bug in windows, it is just a very stupid thing to do in a batch file.

How to set specific window (frame) size in java swing?

Most layout managers work best with a component's preferredSize, and most GUI's are best off allowing the components they contain to set their own preferredSizes based on their content or properties. To use these layout managers to their best advantage, do call pack() on your top level containers such as your JFrames before making them visible as this will tell these managers to do their actions -- to layout their components.

Often when I've needed to play a more direct role in setting the size of one of my components, I'll override getPreferredSize and have it return a Dimension that is larger than the super.preferredSize (or if not then it returns the super's value).

For example, here's a small drag-a-rectangle app that I created for another question on this site:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MoveRect extends JPanel {
   private static final int RECT_W = 90;
   private static final int RECT_H = 70;
   private static final int PREF_W = 600;
   private static final int PREF_H = 300;
   private static final Color DRAW_RECT_COLOR = Color.black;
   private static final Color DRAG_RECT_COLOR = new Color(180, 200, 255);
   private Rectangle rect = new Rectangle(25, 25, RECT_W, RECT_H);
   private boolean dragging = false;
   private int deltaX = 0;
   private int deltaY = 0;

   public MoveRect() {
      MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
      addMouseListener(myMouseAdapter);
      addMouseMotionListener(myMouseAdapter);
   }

   @Override
   protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      if (rect != null) {
         Color c = dragging ? DRAG_RECT_COLOR : DRAW_RECT_COLOR;
         g.setColor(c);
         Graphics2D g2 = (Graphics2D) g;
         g2.draw(rect);
      }
   }

   @Override
   public Dimension getPreferredSize() {
      return new Dimension(PREF_W, PREF_H);
   }

   private class MyMouseAdapter extends MouseAdapter {

      @Override
      public void mousePressed(MouseEvent e) {
         Point mousePoint = e.getPoint();
         if (rect.contains(mousePoint)) {
            dragging = true;
            deltaX = rect.x - mousePoint.x;
            deltaY = rect.y - mousePoint.y;
         }
      }

      @Override
      public void mouseReleased(MouseEvent e) {
         dragging = false;
         repaint();
      }

      @Override
      public void mouseDragged(MouseEvent e) {
         Point p2 = e.getPoint();
         if (dragging) {
            int x = p2.x + deltaX;
            int y = p2.y + deltaY;
            rect = new Rectangle(x, y, RECT_W, RECT_H);
            MoveRect.this.repaint();
         }
      }
   }

   private static void createAndShowGui() {
      MoveRect mainPanel = new MoveRect();

      JFrame frame = new JFrame("MoveRect");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

Note that my main class is a JPanel, and that I override JPanel's getPreferredSize:

public class MoveRect extends JPanel {
   //.... deleted constants

   private static final int PREF_W = 600;
   private static final int PREF_H = 300;

   //.... deleted fields and constants

   //... deleted methods and constructors

   @Override
   public Dimension getPreferredSize() {
      return new Dimension(PREF_W, PREF_H);
   }

Also note that when I display my GUI, I place it into a JFrame, call pack(); on the JFrame, set its position, and then call setVisible(true); on my JFrame:

   private static void createAndShowGui() {
      MoveRect mainPanel = new MoveRect();

      JFrame frame = new JFrame("MoveRect");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

$("#form1").validate is not a function

Had the same issue; validated HTML & found I was missing a name="email" attribute from an <input />. Always validate the HTML to be positive your HTML is valid. After I added it, validate() worked perfectly.

IIs Error: Application Codebehind=“Global.asax.cs” Inherits=“nadeem.MvcApplication”

Make sure the Inherits is pointing to the right namespace of the class because when you create an MVC project under a solution the Inherits value will miss the project name. Therefore you need to fill the gap(project name) manually.

<br><br><%@ Application Codebehind="Global.asax.cs" Inherits="solutionName.projectName.MvcApplication" Language="C#" %>

ASP.NET MVC 3 - redirect to another action

return RedirectToAction("ActionName", "ControllerName");

How to format strings using printf() to get equal length in the output

There's also the %n modifier which can help in certain circumstances. It returns the column on which the string was so far. Example: you want to write several rows that are within the width of the first row like a table.

int width1, width2;
int values[6][2];
printf("|%s%n|%s%n|\n", header1, &width1, header2, &width2);

for(i=0; i<6; i++)
   printf("|%*d|%*d|\n", width1, values[i][0], width2, values[i][1]);

will print two columns of the same width of whatever length the two strings header1 and header2 may have. I don't know if all implementations have the %n, but Solaris and Linux do.

Need to get current timestamp in Java

You can make use of java.util.Date with direct date string format:

String timeStamp = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss").format(new Date());

How to select all and copy in vim?

There are a few important informations missing from your question:

  • output of $ vim --version?
  • OS?
  • CLI or GUI?
  • local or remote?
  • do you use tmux? screen?

If your Vim was built with clipboard support, you are supposed to use the clipboard register like this, in normal mode:

gg"+yG

If your Vim doesn't have clipboard support, you can manage to copy text from Vim to your OS clipboard via other programs. This pretty much depends on your OS but you didn't say what it is so we can't really help.

However, if your Vim is crippled, the best thing to do is to install a proper build with clipboard support but I can't tell you how either because I don't know what OS you use.

edit

On debian based systems, the following command will install a proper Vim with clipboard, ruby, python… support.

$ sudo apt-get install vim-gnome

Hook up Raspberry Pi via Ethernet to laptop without router?

You could use a cross-over ethernet cable - http://en.wikipedia.org/wiki/Ethernet_crossover_cable

Assuming your RPi is a DCHP Client, then best to run a simple DHCP server on your notebook to assign the RPi an IP address.

Find OpenCV Version Installed on Ubuntu

There is also a flag CV_VERSION which will print out the full version of opencv

R Plotting confidence bands with ggplot

require(ggplot2)
require(nlme)

set.seed(101)
mp <-data.frame(year=1990:2010)
N <- nrow(mp)

mp <- within(mp,
         {
             wav <- rnorm(N)*cos(2*pi*year)+rnorm(N)*sin(2*pi*year)+5
             wow <- rnorm(N)*wav+rnorm(N)*wav^3
         })

m01 <- gls(wow~poly(wav,3), data=mp, correlation = corARMA(p=1))

Get fitted values (the same as m01$fitted)

fit <- predict(m01)

Normally we could use something like predict(...,se.fit=TRUE) to get the confidence intervals on the prediction, but gls doesn't provide this capability. We use a recipe similar to the one shown at http://glmm.wikidot.com/faq :

V <- vcov(m01)
X <- model.matrix(~poly(wav,3),data=mp)
se.fit <- sqrt(diag(X %*% V %*% t(X)))

Put together a "prediction frame":

predframe <- with(mp,data.frame(year,wav,
                                wow=fit,lwr=fit-1.96*se.fit,upr=fit+1.96*se.fit))

Now plot with geom_ribbon

(p1 <- ggplot(mp, aes(year, wow))+
    geom_point()+
    geom_line(data=predframe)+
    geom_ribbon(data=predframe,aes(ymin=lwr,ymax=upr),alpha=0.3))

year vs wow

It's easier to see that we got the right answer if we plot against wav rather than year:

(p2 <- ggplot(mp, aes(wav, wow))+
    geom_point()+
    geom_line(data=predframe)+
    geom_ribbon(data=predframe,aes(ymin=lwr,ymax=upr),alpha=0.3))

wav vs wow

It would be nice to do the predictions with more resolution, but it's a little tricky to do this with the results of poly() fits -- see ?makepredictcall.

Check if a string contains another string

There is also the InStrRev function which does the same type of thing, but starts searching from the end of the text to the beginning.

Per @rene's answer...

Dim pos As Integer
pos = InStrRev("find the comma, in the string", ",")

...would still return 15 to pos, but if the string has more than one of the search string, like the word "the", then:

Dim pos As Integer
pos = InStrRev("find the comma, in the string", "the")

...would return 20 to pos, instead of 6.

Find and Replace Inside a Text File from a Bash Command

I found this thread among others and I agree it contains the most complete answers so I'm adding mine too:

  1. sed and ed are so useful...by hand. Look at this code from @Johnny:

    sed -i -e 's/abc/XYZ/g' /tmp/file.txt
    
  2. When my restriction is to use it in a shell script, no variable can be used inside in place of "abc" or "XYZ". The BashFAQ seems to agree with what I understand at least. So, I can't use:

    x='abc'
    y='XYZ'
    sed -i -e 's/$x/$y/g' /tmp/file.txt
    #or,
    sed -i -e "s/$x/$y/g" /tmp/file.txt
    

    but, what can we do? As, @Johnny said use a while read... but, unfortunately that's not the end of the story. The following worked well with me:

    #edit user's virtual domain
    result=
    #if nullglob is set then, unset it temporarily
    is_nullglob=$( shopt -s | egrep -i '*nullglob' )
    if [[ is_nullglob ]]; then
       shopt -u nullglob
    fi
    while IFS= read -r line; do
       line="${line//'<servername>'/$server}"
       line="${line//'<serveralias>'/$alias}"
       line="${line//'<user>'/$user}"
       line="${line//'<group>'/$group}"
       result="$result""$line"'\n'
    done < $tmp
    echo -e $result > $tmp
    #if nullglob was set then, re-enable it
    if [[ is_nullglob ]]; then
       shopt -s nullglob
    fi
    #move user's virtual domain to Apache 2 domain directory
    ......
    
  3. As one can see if nullglob is set then, it behaves strangely when there is a string containing a * as in:

    <VirtualHost *:80>
     ServerName www.example.com
    

    which becomes

    <VirtualHost ServerName www.example.com
    

    there is no ending angle bracket and Apache2 can't even load.

  4. This kind of parsing should be slower than one-hit search and replace but, as you already saw, there are four variables for four different search patterns working out of one parse cycle.

The most suitable solution I can think of with the given assumptions of the problem.

Returning a regex match in VBA (excel)

You need to access the matches in order to get at the SDI number. Here is a function that will do it (assuming there is only 1 SDI number per cell).

For the regex, I used "sdi followed by a space and one or more numbers". You had "sdi followed by a space and zero or more numbers". You can simply change the + to * in my pattern to go back to what you had.

Function ExtractSDI(ByVal text As String) As String

Dim result As String
Dim allMatches As Object
Dim RE As Object
Set RE = CreateObject("vbscript.regexp")

RE.pattern = "(sdi \d+)"
RE.Global = True
RE.IgnoreCase = True
Set allMatches = RE.Execute(text)

If allMatches.count <> 0 Then
    result = allMatches.Item(0).submatches.Item(0)
End If

ExtractSDI = result

End Function

If a cell may have more than one SDI number you want to extract, here is my RegexExtract function. You can pass in a third paramter to seperate each match (like comma-seperate them), and you manually enter the pattern in the actual function call:

Ex) =RegexExtract(A1, "(sdi \d+)", ", ")

Here is:

Function RegexExtract(ByVal text As String, _
                      ByVal extract_what As String, _
                      Optional seperator As String = "") As String

Dim i As Long, j As Long
Dim result As String
Dim allMatches As Object
Dim RE As Object
Set RE = CreateObject("vbscript.regexp")

RE.pattern = extract_what
RE.Global = True
Set allMatches = RE.Execute(text)

For i = 0 To allMatches.count - 1
    For j = 0 To allMatches.Item(i).submatches.count - 1
        result = result & seperator & allMatches.Item(i).submatches.Item(j)
    Next
Next

If Len(result) <> 0 Then
    result = Right(result, Len(result) - Len(seperator))
End If

RegexExtract = result

End Function

*Please note that I have taken "RE.IgnoreCase = True" out of my RegexExtract, but you could add it back in, or even add it as an optional 4th parameter if you like.

Angular ui-grid dynamically calculate height of the grid

A simpler approach is set use css combined with setting the minRowsToShow and virtualizationThreshold value dynamically.

In stylesheet:

.ui-grid, .ui-grid-viewport {
    height: auto !important;
}

In code, call the below function every time you change your data in gridOptions. maxRowToShow is the value you pre-defined, for my use case, I set it to 25.

ES5:

setMinRowsToShow(){
    //if data length is smaller, we shrink. otherwise we can do pagination.
    $scope.gridOptions.minRowsToShow = Math.min($scope.gridOptions.data.length, $scope.maxRowToShow);
    $scope.gridOptions.virtualizationThreshold = $scope.gridOptions.minRowsToShow ;
}

Converting a double to an int in C#

Because Convert.ToInt32 rounds:

Return Value: rounded to the nearest 32-bit signed integer. If value is halfway between two whole numbers, the even number is returned; that is, 4.5 is converted to 4, and 5.5 is converted to 6.

...while the cast truncates:

When you convert from a double or float value to an integral type, the value is truncated.

Update: See Jeppe Stig Nielsen's comment below for additional differences (which however do not come into play if score is a real number as is the case here).

How to compile C++ under Ubuntu Linux?

even you can compile your c++ code by gcc Sounds funny ?? Yes it is. try it

$  gcc avishay.cpp -lstdc++

enjoy

Add leading zeroes to number in Java?

Since Java 1.5 you can use the String.format method. For example, to do the same thing as your example:

String format = String.format("%0%d", digits);
String result = String.format(format, num);
return result;

In this case, you're creating the format string using the width specified in digits, then applying it directly to the number. The format for this example is converted as follows:

%% --> %
0  --> 0
%d --> <value of digits>
d  --> d

So if digits is equal to 5, the format string becomes %05d which specifies an integer with a width of 5 printing leading zeroes. See the java docs for String.format for more information on the conversion specifiers.

Xampp Access Forbidden php

I had this problem after moving the htdocs folder to outside the xampp folder. If you do this then you need to change the document root in httpd.conf. See https://stackoverflow.com/a/1414/3543329.

Alter Table Add Column Syntax

This is how Adding new column to Table

ALTER TABLE [tableName]
ADD ColumnName Datatype

E.g

ALTER TABLE [Emp]
ADD Sr_No Int

And If you want to make it auto incremented

ALTER TABLE [Emp]
ADD Sr_No Int IDENTITY(1,1) NOT NULL

How to open a different activity on recyclerView item onclick

you can implement your adapter's onClickListener:

  public class AdapterClass extends RecyclerView.Adapter<AdapterClass.MyViewHolder>implements View.OnClickListener

and use interface with method in it

public interface mClickListener {
    public void mClick(View v, int position);
}

and in your onClick method call the method in the interface and pass it the view and position

in your main activity implement that interface

public class MainActivity extends ActionBarActivity implements AdapterClass.mClickListener

and override that method

@Override
public void onCommentsClick(View v, int position) {
    final Intent intent = new Intent(this, OtherActivity.class);
}

as its better to manage your activity transition by the activity not other classes

Bootstrap 4 datapicker.js not included

Maybe you want to try this: https://bootstrap-datepicker.readthedocs.org/en/latest/index.html

It's a flexible datepicker widget in the Bootstrap style.

How do I make a WPF TextBlock show my text on multiple lines?

This gets part way there. There is no ActualFontSize property but there is an ActualHeight and that would relate to the FontSize. Right now this only sizes for the original render. I could not figure out how to register the Converter as resize event. Actually maybe need to register the FontSize as a resize event. Please don't mark me down for an incomplete answer. I could not put code sample in a comment.

    <Window.Resources>
        <local:WidthConverter x:Key="widthConverter"/>
    </Window.Resources>
    <Grid>
        <Grid>
            <StackPanel VerticalAlignment="Center" Orientation="Vertical" >
                <Viewbox Margin="100,0,100,0">
                    <TextBlock x:Name="headerText" Text="Lorem ipsum dolor" Foreground="Black"/>
                </Viewbox>
                <TextBlock Margin="150,0,150,0" FontSize="{Binding ElementName=headerText, Path=ActualHeight, Converter={StaticResource widthConverter}}" x:Name="subHeaderText" Text="Lorem ipsum dolor, Lorem ipsum dolor, lorem isum dolor, Lorem ipsum dolor, Lorem ipsum dolor, lorem isum dolor, " TextWrapping="Wrap" Foreground="Gray" />
            </StackPanel>
        </Grid>
    </Grid>        

Converter

    [ValueConversion(typeof(double), typeof(double))]
    public class WidthConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            double width = (double)value*.7;
            return width; // columnsCount;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    } 

fatal: ambiguous argument 'origin': unknown revision or path not in the working tree

For those experiencing this error on CI/CD, adding the line below worked for me on my GitHub Actions CI/CD workflow right after running pip install pyflakes diff-cover:

git fetch origin master:refs/remotes/origin/master

This is a snippet of the solution from the diff-cover github repo:

Solution: diff-cover matches source files in the coverage XML report with source files in the git diff. For this reason, it's important that the relative paths to the files match. If you are using coverage.py to generate the coverage XML report, then make sure you run diff-cover from the same working directory.

I got the solution on the links below. It is a documented diff-cover error.

https://diff-cover.readthedocs.io/en/latest//README.html https://github.com/Bachmann1234/diff_cover/blob/master/README.rst

Hope this helps :-).

What design patterns are used in Spring framework?

Factory Method patter: BeanFactory for creating instance of an object Singleton : instance type can be singleton for a context Prototype : instance type can be prototype. Builder pattern: you can also define a method in a class who will be responsible for creating complex instance.

How to check if a date is greater than another in Java?

Parse the string into date, then compare using compareTo, before or after

Date d = new Date();
d.compareTo(anotherDate)

i.e

Date date1 = new SimpleDateFormat("MM/dd/yyyy").parse(date1string)
Date date2 = new SimpleDateFormat("MM/dd/yyyy").parse(date2string)

date1.compareTo(date2);

Copying the comment provided below by @MuhammadSaqib to complete this answer.

Returns the value 0 if the argument Date is equal to this Date; a value less than 0 if this Date is before the Date argument, and a value greater than 0 if this Date is after the Date argument. and NullPointerException - if anotherDate is null.

javadoc for compareTo http://docs.oracle.com/javase/6/docs/api/java/util/Date.html#compareTo(java.util.Date)

Fast way of finding lines in one file that are not in another?

Using of fgrep or adding -F option to grep could help. But for faster calculations you could use Awk.

You could try one of these Awk methods:

http://www.linuxquestions.org/questions/programming-9/grep-for-huge-files-826030/#post4066219

Adding multiple columns AFTER a specific column in MySQL

One possibility would be to not bother about reordering the columns in the table and simply modify it by add the columns. Then, create a view which has the columns in the order you want -- assuming that the order is truly important. The view can be easily changed to reflect any ordering that you want. Since I can't imagine that the order would be important for programmatic applications, the view should suffice for those manual queries where it might be important.

java collections - keyset() vs entrySet() in map

Traversal over the large map entrySet() is much better than the keySet(). Check this tutorial how they optimise the traversal over the large object with the help of entrySet() and how it helps for performance tuning.

How to add dividers and spaces between items in RecyclerView?

Simple ItemDecoration implementation for equal spaces between all items.

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
    private int space;

    public SpacesItemDecoration(int space) {
        this.space = space;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.left = space;
        outRect.right = space;
        outRect.bottom = space;

        // Add top margin only for the first item to avoid double space between items
        if(parent.getChildAdapterPosition(view) == 0) {
            outRect.top = space;
        }
    }
}

OSX - How to auto Close Terminal window after the "exit" command executed.

I've been using

quit -n terminal

at the end of my scripts. You have to have the terminal set to never prompt in preferences

So Terminal > Preferences > Settings > Shell When the shell exits Close the window Prompt before closing Never

PIL image to array (numpy array to array) - Python

I use numpy.fromiter to invert a 8-greyscale bitmap, yet no signs of side-effects

import Image
import numpy as np

im = Image.load('foo.jpg')
im = im.convert('L')

arr = np.fromiter(iter(im.getdata()), np.uint8)
arr.resize(im.height, im.width)

arr ^= 0xFF  # invert
inverted_im = Image.fromarray(arr, mode='L')
inverted_im.show()

Given a URL to a text file, what is the simplest way to read the contents of the text file?

Another way in Python 3 is to use the urllib3 package.

import urllib3

http = urllib3.PoolManager()
response = http.request('GET', target_url)
data = response.data.decode('utf-8')

This can be a better option than urllib since urllib3 boasts having

  • Thread safety.
  • Connection pooling.
  • Client-side SSL/TLS verification.
  • File uploads with multipart encoding.
  • Helpers for retrying requests and dealing with HTTP redirects.
  • Support for gzip and deflate encoding.
  • Proxy support for HTTP and SOCKS.
  • 100% test coverage.

How to list the properties of a JavaScript object?

Since I use underscore.js in almost every project, I would use the keys function:

var obj = {name: 'gach', hello: 'world'};
console.log(_.keys(obj));

The output of that will be:

['name', 'hello']

VBA Macro to compare all cells of two Excel files

A very simple check you can do with Cell formulas:

Sheet 1 (new - old)

=(if(AND(Ref_New<>"";Ref_Old="");Ref_New;"")

Sheet 2 (old - new)

=(if(AND(Ref_Old<>"";Ref_New="");Ref_Old;"")

This formulas should work for an ENGLISH Excel. For other languages they need to be translated. (For German i can assist)

You need to open all three Excel Documents, then copy the first formula into A1 of your sheet 1 and the second into A1 of sheet 2. Now click in A1 of the first cell and mark "Ref_New", now you can select your reference, go to the new file and click in the A1, go back to sheet1 and do the same for "Ref_Old" with the old file. Replace also the other "Ref_New".

Doe the same for Sheet two.

Now copy the formaula form A1 over the complete range where zour data is in the old and the new file.

But two cases are not covered here:

  1. In the compared cell of New and Old is the same data (Resulting Cell will be empty)
  2. In the compared cell of New and Old is diffe data (Resulting Cell will be empty)

To cover this two cases also, you should create your own function, means learn VBA. A very useful Excel page is cpearson.com

INSERT INTO a temp table, and have an IDENTITY field created, without first declaring the temp table?

If after the *, you alias the id column that is breaking the query a secondtime... and give it a new name... it magically starts working.

select IDENTITY( int ) as TempID, *, SectionID as Fix2IDs
into #TempSections
from Files_Sections

Hex transparency in colors

Using python to calculate this, for example(written in python 3), 50% transparency :

hex(round(256*0.50))

:)

Best GUI designer for eclipse?

It's not free or open source. But you can give Intellij Idea's SWING GUI designer a try.

Deleting multiple columns based on column names in Pandas

The below worked for me:

for col in df:
    if 'Unnamed' in col:
        #del df[col]
        print col
        try:
            df.drop(col, axis=1, inplace=True)
        except Exception:
            pass

filter out multiple criteria using excel vba

I think (from experimenting - MSDN is unhelpful here) that there is no direct way of doing this. Setting Criteria1 to an Array is equivalent to using the tick boxes in the dropdown - as you say it will only filter a list based on items that match one of those in the array.

Interestingly, if you have the literal values "<>A" and "<>B" in the list and filter on these the macro recorder comes up with

Range.AutoFilter Field:=1, Criteria1:="=<>A", Operator:=xlOr, Criteria2:="=<>B"

which works. But if you then have the literal value "<>C" as well and you filter for all three (using tick boxes) while recording a macro, the macro recorder replicates precisely your code which then fails with an error. I guess I'd call that a bug - there are filters you can do using the UI which you can't do with VBA.

Anyway, back to your problem. It is possible to filter values not equal to some criteria, but only up to two values which doesn't work for you:

Range("$A$1:$A$9").AutoFilter Field:=1, Criteria1:="<>A", Criteria2:="<>B", Operator:=xlAnd

There are a couple of workarounds possible depending on the exact problem:

  1. Use a "helper column" with a formula in column B and then filter on that - e.g. =ISNUMBER(A2) or =NOT(A2="A", A2="B", A2="C") then filter on TRUE
  2. If you can't add a column, use autofilter with Criteria1:=">-65535" (or a suitable number lower than any you expect) which will filter out non-numeric values - assuming this is what you want
  3. Write a VBA sub to hide rows (not exactly the same as an autofilter but it may suffice depending on your needs).

For example:

Public Sub hideABCRows(rangeToFilter As Range)
  Dim oCurrentCell As Range
  On Error GoTo errHandler

  Application.ScreenUpdating = False
  For Each oCurrentCell In rangeToFilter.Cells
    If oCurrentCell.Value = "A" Or oCurrentCell.Value = "B" Or oCurrentCell.Value = "C" Then
      oCurrentCell.EntireRow.Hidden = True
    End If
  Next oCurrentCell

  Application.ScreenUpdating = True
  Exit Sub

errHandler:
    Application.ScreenUpdating = True
End Sub

How do I hide the PHP explode delimiter from submitted form results?

You could try a different approach like read the file line by line instead of dealing with all this nl2br / explode stuff.

$fh = fopen("employees.txt", "r"); if ($fh) {     while (($line = fgets($fh)) !== false) {         $line = trim($line);         echo "<option value='".$line."'>".$line."</option>";     } } else {     // error opening the file, do something } 

Also maybe just doing a trim (remove whitespace from beginning/end of string) is your issue?

And maybe people are just misunderstanding what you mean by "submitting results to a spreadsheet" -- are you doing this with code? or a copy/paste from an HTML page into a spreadsheet? Maybe you can explain that in more detail. The delimiter for which you split the lines of the file shouldn't be displaying in the output anyway unless you have unexpected output for some other reason.

Get page title with Selenium WebDriver using Java

You can do it easily by using JUnit or TestNG framework. Do the assertion as below:

String actualTitle = driver.getTitle();
String expectedTitle = "Title of Page";
assertEquals(expectedTitle,actualTitle);

OR,

assertTrue(driver.getTitle().contains("Title of Page"));

how to convert an RGB image to numpy array?

You can get numpy array of rgb image easily by using numpy and Image from PIL

import numpy as np
from PIL import Image
import matplotlib.pyplot as plt

im = Image.open('*image_name*') #These two lines
im_arr = np.array(im) #are all you need
plt.imshow(im_arr) #Just to verify that image array has been constructed properly

How are ssl certificates verified?

You said that

the browser gets the certificate's issuer information from that certificate, then uses that to contact the issuerer, and somehow compares certificates for validity.

The client doesn't have to check with the issuer because two things :

  1. all browsers have a pre-installed list of all major CAs public keys
  2. the certificate is signed, and that signature itself is enough proof that the certificate is valid because the client can make sure, by his own, and without contacting the issuer's server, that that certificate is authentic. That's the beauty of asymmetric encryption.

Notice that 2. can't be done without 1.

This is better explained in this big diagram I made some time ago

(skip to "what's a signature ?" at the bottom)

blob

jQuery equivalent of JavaScript's addEventListener method

You should now use the .on() function to bind events.

Converting ArrayList to HashMap

Using a supposed name property as the map key:

for (Product p: productList) { s.put(p.getName(), p); }

Dynamically display a CSV file as an HTML table on a web page

The previously linked solution is a horrible piece of code; nearly every line contains a bug. Use fgetcsv instead:

<?php
echo "<html><body><table>\n\n";
$f = fopen("so-csv.csv", "r");
while (($line = fgetcsv($f)) !== false) {
        echo "<tr>";
        foreach ($line as $cell) {
                echo "<td>" . htmlspecialchars($cell) . "</td>";
        }
        echo "</tr>\n";
}
fclose($f);
echo "\n</table></body></html>";

Selected value for JSP drop down using JSTL

Maybe I don't completely understand the accepted answer so it didn't work for me.

What i did was simply to check if the variable is null, assign it to a known value from my database. Which seems to be similar to the accepted answer whereby you first declare an known value and set it to selected

<select name="department">
    <c:forEach var="item" items="${dept}">
        <option value="${item.key}">${item.value}</option>
    </c:forEach>
</select>

because none of the options are selected, thus item = null

<%
    if(item == null){
        item = "selectedDept"; //known value from your database
    }
%>

This way if the user then selects another option, my IF clause will not catch it and assign to the fixed value that was declared at the start. My concept could be wrong here but it works for me

SELECT * FROM X WHERE id IN (...) with Dapper ORM

It is not necessary to add () in the WHERE clause as we do in a regular SQL. Because Dapper does that automatically for us. Here is the syntax:-

const string SQL = "SELECT IntegerColumn, StringColumn FROM SomeTable WHERE IntegerColumn IN @listOfIntegers";

var conditions = new { listOfIntegers };
    
var results = connection.Query(SQL, conditions);

Hash table runtime complexity (insert, search and delete)

Depends on the how you implement hashing, in the worst case it can go to O(n), in best case it is 0(1) (generally you can achieve if your DS is not that big easily)

How do I pause my shell script for a second before continuing?

Use the sleep command.

Example:

sleep .5 # Waits 0.5 second.
sleep 5  # Waits 5 seconds.
sleep 5s # Waits 5 seconds.
sleep 5m # Waits 5 minutes.
sleep 5h # Waits 5 hours.
sleep 5d # Waits 5 days.

One can also employ decimals when specifying a time unit; e.g. sleep 1.5s

Custom Listview Adapter with filter Android

you can find custom list adapter class with filterable using text change in edit text...

create custom list adapter class with implementation of Filterable:

private class CustomListAdapter extends BaseAdapter implements Filterable{

    private LayoutInflater inflater;
    private ViewHolder holder;
    private ItemFilter mFilter = new ItemFilter();

    public CustomListAdapter(List<YourCustomData> newlist) {
        filteredData = newlist;
    }

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

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        holder = new ViewHolder();

        if(inflater==null)
            inflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if(convertView == null){
            convertView = inflater.inflate(R.layout.row_listview_item, null);

            holder.mTextView = (TextView)convertView.findViewById(R.id.row_listview_member_tv);

            convertView.setTag(holder);
        }else{
            holder = (ViewHolder)convertView.getTag();
        }

        holder.mTextView.setText(""+filteredData.get(position).getYourdata());

        return convertView;
    }

    @Override
    public Filter getFilter() {
        return mFilter;
    }


}

class ViewHolder{
    TextView mTextView;
}

private class ItemFilter extends Filter {
    @SuppressLint("DefaultLocale")
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {

        String filterString = constraint.toString().toLowerCase();

        FilterResults results = new FilterResults();

        final List<YourCustomData> list = YourObject.getYourDataList();

        int count = list.size();
        final ArrayList<YourCustomData> nlist = new ArrayList<YourCustomData>(count);

        String filterableString ;

        for (int i = 0; i < count; i++) {
            filterableString = ""+list.get(i).getYourText();
            if (filterableString.toLowerCase().contains(filterString)) {
                YourCustomData mYourCustomData = list.get(i);
                nlist.add(mYourCustomData);
            }
        }

        results.values = nlist;
        results.count = nlist.size();

        return results;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
        filteredData = (ArrayList<YourCustomData>) results.values;
        mCustomListAdapter.notifyDataSetChanged();
    }

}

mEditTextSearch.addTextChangedListener(new TextWatcher() {
        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            if(mCustomListAdapter!=null)
                mCustomListAdapter.getFilter().filter(s.toString());

        }
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        }
        @Override
        public void afterTextChanged(Editable s) {
        }
    });

Get name of current class?

I think, it should be like this:

    class foo():
        input = get_input(__qualname__)

How to install a specific version of package using Composer?

composer require vendor/package:version

for example:

composer require refinery29/test-util:0.10.2

Set value for particular cell in pandas DataFrame using index

Soo, your question to convert NaN at ['x',C] to value 10

the answer is..

df['x'].loc['C':]=10
df

alternative code is

df.loc['C', 'x']=10
df

Using CSS in Laravel views?

That is not possible bro, Laravel assumes everything is in public folder.

So my suggestion is:

  1. Go to the public folder.
  2. Create a folder, preferably named css.
  3. Create the folder for the respective views to make things organized.
  4. Put the respective css inside of those folders, that would be easier for you.

Or

If you really insist to put css inside of views folder, you could try creating Symlink (you're mac so it's ok, but for windows, this will only work for Vista, Server 2008 or greater) from your css folder directory to the public folder and you can use {{HTML::style('your_view_folder/myStyle.css')}} inside of your view files, here's a code for your convenience, in the code you posted, put these before the return View::make():

$css_file = 'myStyle.css';
$folder_name = 'your_view_folder';
$view_path = app_path() . '/views/' . $folder_name . '/' . $css_file;
$public_css_path = public_path() . '/' . $folder_name;
if(file_exists($public_css_path)) exec('rm -rf ' . $public_css_path);
exec('mkdir ' . $public_css_path);
exec('ln -s ' . $view_path .' ' . $public_css_path . '/' . $css_file);

If you really want to try doing your idea, try this:

<link rel="stylesheet" href="<?php echo app_path() . 'views/your_view_folder/myStyle.css'?>" type="text/css">

But it won't work even if the file directory is correct because Laravel won't do that for security purposes, Laravel loves you that much.

How can I calculate divide and modulo for integers in C#?

Fun fact!

The 'modulus' operation is defined as:

a % n ==> a - (a/n) * n

Ref:Modular Arithmetic

So you could roll your own, although it will be FAR slower than the built in % operator:

public static int Mod(int a, int n)
{
    return a - (int)((double)a / n) * n;
}

Edit: wow, misspoke rather badly here originally, thanks @joren for catching me

Now here I'm relying on the fact that division + cast-to-int in C# is equivalent to Math.Floor (i.e., it drops the fraction), but a "true" implementation would instead be something like:

public static int Mod(int a, int n)
{
    return a - (int)Math.Floor((double)a / n) * n;
}

In fact, you can see the differences between % and "true modulus" with the following:

var modTest =
    from a in Enumerable.Range(-3, 6)
    from b in Enumerable.Range(-3, 6)
    where b != 0
    let op = (a % b)
    let mod = Mod(a,b)
    let areSame = op == mod
    select new 
    { 
        A = a,
        B = b,
        Operator = op, 
        Mod = mod, 
        Same = areSame
    };
Console.WriteLine("A      B     A%B   Mod(A,B)   Equal?");
Console.WriteLine("-----------------------------------");
foreach (var result in modTest)
{
    Console.WriteLine(
        "{0,-3} | {1,-3} | {2,-5} | {3,-10} | {4,-6}", 
        result.A,
        result.B,
        result.Operator, 
        result.Mod, 
        result.Same);
}

Results:

A      B     A%B   Mod(A,B)   Equal?
-----------------------------------
-3  | -3  | 0     | 0          | True  
-3  | -2  | -1    | -1         | True  
-3  | -1  | 0     | 0          | True  
-3  | 1   | 0     | 0          | True  
-3  | 2   | -1    | 1          | False 
-2  | -3  | -2    | -2         | True  
-2  | -2  | 0     | 0          | True  
-2  | -1  | 0     | 0          | True  
-2  | 1   | 0     | 0          | True  
-2  | 2   | 0     | 0          | True  
-1  | -3  | -1    | -1         | True  
-1  | -2  | -1    | -1         | True  
-1  | -1  | 0     | 0          | True  
-1  | 1   | 0     | 0          | True  
-1  | 2   | -1    | 1          | False 
0   | -3  | 0     | 0          | True  
0   | -2  | 0     | 0          | True  
0   | -1  | 0     | 0          | True  
0   | 1   | 0     | 0          | True  
0   | 2   | 0     | 0          | True  
1   | -3  | 1     | -2         | False 
1   | -2  | 1     | -1         | False 
1   | -1  | 0     | 0          | True  
1   | 1   | 0     | 0          | True  
1   | 2   | 1     | 1          | True  
2   | -3  | 2     | -1         | False 
2   | -2  | 0     | 0          | True  
2   | -1  | 0     | 0          | True  
2   | 1   | 0     | 0          | True  
2   | 2   | 0     | 0          | True  

How do you round a floating point number in Perl?

See perldoc/perlfaq:

Remember that int() merely truncates toward 0. For rounding to a certain number of digits, sprintf() or printf() is usually the easiest route.

 printf("%.3f",3.1415926535);
 # prints 3.142

The POSIX module (part of the standard Perl distribution) implements ceil(), floor(), and a number of other mathematical and trigonometric functions.

use POSIX;
$ceil  = ceil(3.5); # 4
$floor = floor(3.5); # 3

In 5.000 to 5.003 perls, trigonometry was done in the Math::Complex module.

With 5.004, the Math::Trig module (part of the standard Perl distribution) > implements the trigonometric functions.

Internally it uses the Math::Complex module and some functions can break out from the real axis into the complex plane, for example the inverse sine of 2.

Rounding in financial applications can have serious implications, and the rounding method used should be specified precisely. In these cases, it probably pays not to trust whichever system rounding is being used by Perl, but to instead implement the rounding function you need yourself.

To see why, notice how you'll still have an issue on half-way-point alternation:

for ($i = 0; $i < 1.01; $i += 0.05)
{
   printf "%.1f ",$i
}

0.0 0.1 0.1 0.2 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5 0.6 0.7 0.7 0.8 0.8 0.9 0.9 1.0 1.0

Don't blame Perl. It's the same as in C. IEEE says we have to do this. Perl numbers whose absolute values are integers under 2**31 (on 32 bit machines) will work pretty much like mathematical integers. Other numbers are not guaranteed.

Rotating x axis labels in R for barplot

use optional parameter las=2 .

barplot(mytable,main="Car makes",ylab="Freqency",xlab="make",las=2)

enter image description here

How to add an image in the title bar using html?

I just tried with this code, and it worked for me: <link rel="icon" type="image/jpg" href="C:\Users\nrm05\Pictures\logo.jpg" /> Be sure to type type="image/jpg" for jpg files, and type="image/png" for PNG files. If you haven't downloaded the image, but you know the image URL, then you can type it in like this: href="image_url"

Hope this answered your question :-)

Data binding to SelectedItem in a WPF Treeview

(Let's just all agree that TreeView is obviously busted in respect to this problem. Binding to SelectedItem would have been obvious. Sigh)

I needed the solution to interact properly with the IsSelected property of TreeViewItem, so here's how I did it:

// the Type CustomThing needs to implement IsSelected with notification
// for this to work.
public class CustomTreeView : TreeView
{
    public CustomThing SelectedCustomThing
    {
        get
        {
            return (CustomThing)GetValue(SelectedNode_Property);
        }
        set
        {
            SetValue(SelectedNode_Property, value);
            if(value != null) value.IsSelected = true;
        }
    }

    public static DependencyProperty SelectedNode_Property =
        DependencyProperty.Register(
            "SelectedCustomThing",
            typeof(CustomThing),
            typeof(CustomTreeView),
            new FrameworkPropertyMetadata(
                null,
                FrameworkPropertyMetadataOptions.None,
                SelectedNodeChanged));

    public CustomTreeView(): base()
    {
        this.SelectedItemChanged += new RoutedPropertyChangedEventHandler<object>(SelectedItemChanged_CustomHandler);
    }

    void SelectedItemChanged_CustomHandler(object sender, RoutedPropertyChangedEventArgs<object> e)
    {
        SetValue(SelectedNode_Property, SelectedItem);
    }

    private static void SelectedNodeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        var treeView = d as CustomTreeView;
        var newNode = e.NewValue as CustomThing;

        treeView.SelectedCustomThing = (CustomThing)e.NewValue;
    }
}

With this XAML:

<local:CustonTreeView ItemsSource="{Binding TreeRoot}" 
    SelectedCustomThing="{Binding SelectedNode,Mode=TwoWay}">
    <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}" />
        </Style>
    </TreeView.ItemContainerStyle>
</local:CustonTreeView>

What is the best way to get the minimum or maximum value from an Array of numbers?

You have to loop through the array, no other way to check all elements. Just one correction for the code - if all elements are negative, maxValue will be 0 at the end. You should initialize it with the minimum possible value for integer.
And if you are going to search the array many times it's a good idea to sort it first, than searching is faster (binary search) and minimum and maximum elements are just the first and the last.

Java: Unresolved compilation problem

I got this error multiple times and struggled to work out. Finally, I removed the run configuration and re-added the default entries. It worked beautifully.

Giving height to table and row in Bootstrap

For the <tr>'s just set

tr {
   line-height: 25px;
   min-height: 25px;
   height: 25px;
}

It works with bootstrap also. For the 100% height, 100% must be 100% of something. Therefore, you must define a fixed height for one of the containers, or the body. I guess you want the entire page to be 100%, so (example) :

body {
    height: 700px;
}
.table100, .row, .container, .table-responsive, .table-bordered  {
    height: 100%;
}

A workaround not to set a static height is by forcing the height in code according to the viewport :

$('body').height(document.documentElement.clientHeight);

all the above in this fiddle -> http://jsfiddle.net/LZuJt/

Note : I do not care that you have 25% height on #description, and 100% height on table. Guess it is just an example. And notice that clientHeight is not right since the documentElement is an iframe, but you'll get the picture in your own projekt :)

Case Statement Equivalent in R

I see no proposal for 'switch'. Code example (run it):

x <- "three"
y <- 0
switch(x,
       one = {y <- 5},
       two = {y <- 12},
       three = {y <- 432})
y

Rename column SQL Server 2008

It would be a good suggestion to use an already built-in function but another way around is to:

  1. Create a new column with same data type and NEW NAME.
  2. Run an UPDATE/INSERT statement to copy all the data into new column.
  3. Drop the old column.

The benefit behind using the sp_rename is that it takes care of all the relations associated with it.

From the documentation:

sp_rename automatically renames the associated index whenever a PRIMARY KEY or UNIQUE constraint is renamed. If a renamed index is tied to a PRIMARY KEY constraint, the PRIMARY KEY constraint is also automatically renamed by sp_rename. sp_rename can be used to rename primary and secondary XML indexes.

PHP CSV string to array

Try this, it's working for me:

$delimiter = ",";
  $enclosure = '"';
  $escape = "\\" ;
  $rows = array_filter(explode(PHP_EOL, $content));
  $header = NULL;
  $data = [];

  foreach($rows as $row)
  {
    $row = str_getcsv ($row, $delimiter, $enclosure , $escape);

    if(!$header) {
      $header = $row;
    } else {
      $data[] = array_combine($header, $row);
    }
  }

How to read a line from the console in C?

You might need to use a character by character (getc()) loop to ensure you have no buffer overflows and don't truncate the input.

Downloading jQuery UI CSS from Google's CDN

You could use this one if you mean the jQuery UI css:

<link rel="stylesheet" type="text/css" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />

Get HTML inside iframe using jQuery

Just for reference's sake. This is how to do it with JQuery (useful for instance when you cannot query by element id):

$('#iframe').get(0).contentWindow.document.body.innerHTML

Print to the same line and not a new line?

Try it like this:

for i in some_list:
    #do a bunch of stuff.
    print i/len(some_list)*100," percent complete",

(With a comma at the end.)

Unlink of file Failed. Should I try again?

I had this kind of issue on Windows 7 and it turned out to be due to some orphaned git.exe process.

To solve it, open Task Manager and kill all git.exe processes.

Since git commands are short-lived, you should normally never see any git.exe in Task Manager. When they are there, it usually means something is wrong, and you should kill those processes.

How to read a text file?

It depends on what you are trying to do.

file, err := os.Open("file.txt")
fmt.print(file)

The reason it outputs &{0xc082016240}, is because you are printing the pointer value of a file-descriptor (*os.File), not file-content. To obtain file-content, you may READ from a file-descriptor.


To read all file content(in bytes) to memory, ioutil.ReadAll

package main

import (
    "fmt"
    "io/ioutil"
    "os"
    "log"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


  b, err := ioutil.ReadAll(file)
  fmt.Print(b)
}

But sometimes, if the file size is big, it might be more memory-efficient to just read in chunks: buffer-size, hence you could use the implementation of io.Reader.Read from *os.File

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()


    buf := make([]byte, 32*1024) // define your buffer size here.

    for {
        n, err := file.Read(buf)

        if n > 0 {
            fmt.Print(buf[:n]) // your read buffer.
        }

        if err == io.EOF {
            break
        }
        if err != nil {
            log.Printf("read %d bytes: %v", n, err)
            break
        }
    }

}

Otherwise, you could also use the standard util package: bufio, try Scanner. A Scanner reads your file in tokens: separator.

By default, scanner advances the token by newline (of course you can customise how scanner should tokenise your file, learn from here the bufio test).

package main

import (
    "fmt"
    "os"
    "log"
    "bufio"
)

func main() {
    file, err := os.Open("file.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        if err = f.Close(); err != nil {
            log.Fatal(err)
        }
    }()

    scanner := bufio.NewScanner(file)

    for scanner.Scan() {             // internally, it advances token based on sperator
        fmt.Println(scanner.Text())  // token in unicode-char
        fmt.Println(scanner.Bytes()) // token in bytes

    }
}

Lastly, I would also like to reference you to this awesome site: go-lang file cheatsheet. It encompassed pretty much everything related to working with files in go-lang, hope you'll find it useful.

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

That method was added in Servlet 2.5.

So this problem can have at least 3 causes:

  1. The servlet container does not support Servlet 2.5.
  2. The web.xml is not declared conform Servlet 2.5 or newer.
  3. The webapp's runtime classpath is littered with servlet container specific JAR files of a different servlet container make/version which does not support Servlet 2.5.

To solve it,

  1. Make sure that your servlet container supports at least Servlet 2.5. That are at least Tomcat 6, Glassfish 2, JBoss AS 4.1, etcetera. Tomcat 5.5 for example supports at highest Servlet 2.4. If you can't upgrade Tomcat, then you'd need to downgrade Spring to a Servlet 2.4 compatible version.
  2. Make sure that the root declaration of web.xml complies Servlet 2.5 (or newer, at least the highest whatever your target runtime supports). For an example, see also somewhere halfway our servlets wiki page.
  3. Make sure that you don't have any servlet container specific libraries like servlet-api.jar or j2ee.jar in /WEB-INF/lib or even worse, the JRE/lib or JRE/lib/ext. They do not belong there. This is a pretty common beginner's mistake in an attempt to circumvent compilation errors in an IDE, see also How do I import the javax.servlet API in my Eclipse project?.

Checkout multiple git repos into same Jenkins workspace

Checking out more than one repo at a time in a single workspace is possible with Jenkins + Git Plugin (maybe only in more recent versions?).

In section "Source-Code-Management", do not select "Git", but "Multiple SCMs" and add several git repositories.

Be sure that in all but one you add as an "Additional behavior" the action "Check out to a sub-directory" and specify an individual subdirectory.

How do I install a module globally using npm?

On a Mac, I found the output contained the information I was looking for:

$> npm install -g karma
...
...
> [email protected] install /usr/local/share/npm/lib/node_modules/karma/node_modules/socket.io/node_modules/socket.io-client/node_modules/ws
> (node-gyp rebuild 2> builderror.log) || (exit 0)
...
$> ls /usr/local/share/npm/bin
karma nf

After adding /usr/local/share/npm/bin to the export PATH line in my .bash_profile, saving it, and sourceing it, I was able to run

$> karma --help

normally.

What's the difference between an Angular component and module

A module in Angular 2 is something which is made from components, directives, services etc. One or many modules combine to make an Application. Modules breakup application into logical pieces of code. Each module performs a single task.

Components in Angular 2 are classes where you write your logic for the page you want to display. Components control the view (html). Components communicate with other components and services.

How to convert an Instant to a date format?

Instant i = Instant.ofEpochSecond(cal.getTime);

Read more here and here

Error including image in Latex

I use MacTex, and my editor is TexShop. It probably has to do with what compiler you are using. When I use pdftex, the command:

\includegraphics[height=60mm, width=100mm]{number2.png}

works fine, but when I use "Tex and Ghostscript", I get the same error as you, about not being able to get the size information. Use pdftex.

Incidentally, you can change this in TexShop from the "Typeset" menu.

Hope this helps.

Ajax passing data to php script

You can also use bellow code for pass data using ajax.

var dataString = "album" + title;
$.ajax({  
    type: 'POST',  
    url: 'test.php', 
    data: dataString,
    success: function(response) {
        content.html(response);
    }
});

How to avoid 'undefined index' errors?

Set each index in the array at the beginning (or before the $output array is used) would probably be the easiest solution for your case.

Example

$output['admin_link'] = ""
$output['alternate_title'] = ""
$output['access_info'] = ""
$output['description'] = ""
$output['url'] = ""

Also not really relevant for your case but where you said you were new to PHP and this is not really immediately obvious isset() can take multiple arguments. So in stead of this:

if(isset($var1) && isset($var2) && isset($var3) ...){
    // all are set
}

You can do:

if(isset($var1, $var2, $var3)){
   // all are set 
}

How to open warning/information/error dialog in Swing?

JOptionPane.showOptionDialog
JOptionPane.showMessageDialog
....

Have a look on this tutorial on how to make dialogs.

getting file size in javascript

If it's not a local application powered by JavaScript with full access permissions, you can't get the size of any file just from the path name. Web pages running javascript do not have access to the local filesystem for security reasons.

You can use a graceful degrading file uploader like SWFUpload if you want to show a progress bar. HTML5 also has the File API, but that is not widely supported just yet. If a user selects the file for an input[type=file] element, you can get details about the file from the files collection:

alert(myInp.files[0].size);

Accessing items in an collections.OrderedDict by index

This community wiki attempts to collect existing answers.

Python 2.7

In python 2, the keys(), values(), and items() functions of OrderedDict return lists. Using values as an example, the simplest way is

d.values()[0]  # "python"
d.values()[1]  # "spam"

For large collections where you only care about a single index, you can avoid creating the full list using the generator versions, iterkeys, itervalues and iteritems:

import itertools
next(itertools.islice(d.itervalues(), 0, 1))  # "python"
next(itertools.islice(d.itervalues(), 1, 2))  # "spam"

The indexed.py package provides IndexedOrderedDict, which is designed for this use case and will be the fastest option.

from indexed import IndexedOrderedDict
d = IndexedOrderedDict({'foo':'python','bar':'spam'})
d.values()[0]  # "python"
d.values()[1]  # "spam"

Using itervalues can be considerably faster for large dictionaries with random access:

$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 1000;   d = OrderedDict({i:i for i in range(size)})'  'i = randint(0, size-1); d.values()[i:i+1]'
1000 loops, best of 3: 259 usec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 10000;  d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i:i+1]'
100 loops, best of 3: 2.3 msec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 100000; d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i:i+1]'
10 loops, best of 3: 24.5 msec per loop

$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 1000;   d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
10000 loops, best of 3: 118 usec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 10000;  d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
1000 loops, best of 3: 1.26 msec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 100000; d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
100 loops, best of 3: 10.9 msec per loop

$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 1000;   d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.19 usec per loop
$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 10000;  d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.24 usec per loop
$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 100000; d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.61 usec per loop

+--------+-----------+----------------+---------+
|  size  | list (ms) | generator (ms) | indexed |
+--------+-----------+----------------+---------+
|   1000 | .259      | .118           | .00219  |
|  10000 | 2.3       | 1.26           | .00224  |
| 100000 | 24.5      | 10.9           | .00261  |
+--------+-----------+----------------+---------+

Python 3.6

Python 3 has the same two basic options (list vs generator), but the dict methods return generators by default.

List method:

list(d.values())[0]  # "python"
list(d.values())[1]  # "spam"

Generator method:

import itertools
next(itertools.islice(d.values(), 0, 1))  # "python"
next(itertools.islice(d.values(), 1, 2))  # "spam"

Python 3 dictionaries are an order of magnitude faster than python 2 and have similar speedups for using generators.

+--------+-----------+----------------+---------+
|  size  | list (ms) | generator (ms) | indexed |
+--------+-----------+----------------+---------+
|   1000 | .0316     | .0165          | .00262  |
|  10000 | .288      | .166           | .00294  |
| 100000 | 3.53      | 1.48           | .00332  |
+--------+-----------+----------------+---------+

Mapping composite keys using EF code first

For Mapping Composite primary key using Entity framework we can use two approaches.

1) By Overriding the OnModelCreating() Method

For ex: I have the model class named VehicleFeature as shown below.

public class VehicleFeature
{
    public int VehicleId { get; set; }
    public int FeatureId{get;set;}
    public Vehicle Vehicle{get;set;}
    public Feature Feature{get;set;}
}

The Code in my DBContext would be like ,

public class VegaDbContext : DbContext
{
    public DbSet<Make> Makes{get;set;}

    public DbSet<Feature> Features{get;set;}
    public VegaDbContext(DbContextOptions<VegaDbContext> options):base(options)        
    {           

    }
    // we override the OnModelCreating method here.
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<VehicleFeature>().HasKey(vf=> new {vf.VehicleId, vf.FeatureId});
    }
}

2) By Data Annotations.

public class VehicleFeature
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]  
    [Key]
    public int VehicleId { get; set; }
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]   
    [Key]
    public int FeatureId{get;set;}
    public Vehicle Vehicle{get;set;}
    public Feature Feature{get;set;}
}

Please refer the below links for the more information.

1) https://msdn.microsoft.com/en-us/library/jj591617(v=vs.113).aspx

2) How to add a composite unique key using EF 6 Fluent Api?

Log4net rolling daily filename with date in the file name

To preserve file extension:

<log4net>
    <root>
      <level value="DEBUG"/>
      <appender-ref ref="RollingLogFileAppender"/>
    </root>
    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file type="log4net.Util.PatternString" value="D:\\LogFolder\\%date{yyyyMM}\\SchT.log" />
      <appendToFile value="true" />
      <rollingStyle value="Date" />
      <maximumFileSize value="30MB" />
      <staticLogFileName value="true" />
      <preserveLogFileNameExtension value="true"/>
      <datePattern value="ddMMyyyy" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger - %message%newline" />
      </layout>
    </appender>
  </log4net>

PYODBC--Data source name not found and no default driver specified

I'm using

Django 2.2

and got the same error while connecting to sql-server 2012. Spent lot of time to solve this issue and finally this worked.

I changed

'driver': 'ODBC Driver 13 for SQL Server'

to

'driver': 'SQL Server Native Client 11.0'

and it worked.

"No such file or directory" error when executing a binary

You get this error when you try to run a 32-bit build on your 64-bit Linux.

Also contrast what file had to say on the binary you tried (ie: 32-bit) with what you get for your /bin/gzip:

$ file /bin/gzip
/bin/gzip: ELF 64-bit LSB executable, x64-64, version 1 (SYSV), \
dynamically linked (uses shared libs), for GNU/Linux 2.6.15, stripped

which is what I get on Ubuntu 9.10 for amd64 aka x86_64.

Edit: Your expanded post shows that as the readelf output also reflects a 32-bit build.

Equivalent of varchar(max) in MySQL?

TLDR; MySql does not have an equivalent concept of varchar(max), this is a MS SQL Server feature.

What is VARCHAR(max)?

varchar(max) is a feature of Microsoft SQL Server.

The amount of data that a column could store in Microsoft SQL server versions prior to version 2005 was limited to 8KB. In order to store more than 8KB you would have to use TEXT, NTEXT, or BLOB columns types, these column types stored their data as a collection of 8K pages separate from the table data pages; they supported storing up to 2GB per row.

The big caveat to these column types was that they usually required special functions and statements to access and modify the data (e.g. READTEXT, WRITETEXT, and UPDATETEXT)

In SQL Server 2005, varchar(max) was introduced to unify the data and queries used to retrieve and modify data in large columns. The data for varchar(max) columns is stored inline with the table data pages.

As the data in the MAX column fills an 8KB data page an overflow page is allocated and the previous page points to it forming a linked list. Unlike TEXT, NTEXT, and BLOB the varchar(max) column type supports all the same query semantics as other column types.

So varchar(MAX) really means varchar(AS_MUCH_AS_I_WANT_TO_STUFF_IN_HERE_JUST_KEEP_GROWING) and not varchar(MAX_SIZE_OF_A_COLUMN).

MySql does not have an equivalent idiom.

In order to get the same amount of storage as a varchar(max) in MySql you would still need to resort to a BLOB column type. This article discusses a very effective method of storing large amounts of data in MySql efficiently.

How can I make a button redirect my page to another page?

This is here:

 <button onClick="window.location='page_name.php';" value="click here" />

Which Architecture patterns are used on Android?

The Following Android Classes uses Design Patterns

1) View Holder uses Singleton Design Pattern

2) Intent uses Factory Design Pattern

3) Adapter uses Adapter Design Pattern

4) Broadcast Receiver uses Observer Design Pattern

5) View uses Composite Design Pattern

6) Media FrameWork uses Façade Design Pattern

UIButton: set image for selected-highlighted state

Swift 3

// Default state (previously `.Normal`)
button.setImage(UIImage(named: "image1"), for: [])

// Highlighted
button.setImage(UIImage(named: "image2"), for: .highlighted)

// Selected
button.setImage(UIImage(named: "image3"), for: .selected)

// Selected + Highlighted
button.setImage(UIImage(named: "image4"), for: [.selected, .highlighted])

To set the background image we can use setBackgroundImage(_:for:)

Swift 2.x

// Normal
button.setImage(UIImage(named: "image1"), forState: .Normal)

// Highlighted
button.setImage(UIImage(named: "image2"), forState: .Highlighted)

// Selected
button.setImage(UIImage(named: "image3"), forState: .Selected)

// Selected + Highlighted
button.setImage(UIImage(named: "image4"), forState: [.Selected, .Highlighted])

docker error - 'name is already in use by container'

Simple Solution: Goto your docker folder in the system and delete .raw file or docker archive with large size.

Set up adb on Mac OS X

Add environment variable for Android Home Targetting Platform Tools

echo 'export ANDROID_HOME=/Users/$USER/Library/Android/sdk' >> ~/.bash_profile

echo 'export PATH=${PATH}:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools' >> ~/.bash_profile

Restart Bash

source ~/.bash_profile

Now Check adb

Simply type

adb

on terminal

How do I convert from a money datatype in SQL server?

Would casting it to int help you? Money is meant to have the decimal places...

DECLARE @test AS money
SET @test = 3
SELECT CAST(@test AS int), @test

How to fix 'Unchecked runtime.lastError: The message port closed before a response was received' chrome issue?

In my case it was a breakpoint set in my own page source. If I removed or disabled the breakpoint then the error would clear up.

The breakpoint was in a moderately complex chunk of rendering code. Other breakpoints in different parts of the page had no such effect. I was not able to work out a simple test case that always trigger this error.

Why doesn't "System.out.println" work in Android?

I'll leave this for further visitors as for me it was something about the main thread being unable to System.out.println.

public class LogUtil {

private static String log = "";
private static boolean started = false;
public static void print(String s) {
    //Start the thread unless it's already running
    if(!started) {
        start();
    }
    //Append a String to the log
    log += s;
}

public static void println(String s) {
    //Start the thread unless it's already running
    if(!started) {
        start();
    }
    //Append a String to the log with a newline.
    //NOTE: Change to print(s + "\n") if you don't want it to trim the last newline.
    log += (s.endsWith("\n") )? s : (s + "\n");
}

private static void start() {
    //Creates a new Thread responsible for showing the logs.
    Thread thread = new Thread(new Runnable() {
        @Override
        public void run() {
            while(true) {
                //Execute 100 times per second to save CPU cycles.
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                //If the log variable has any contents...
                if(!log.isEmpty()) {
                    //...print it and clear the log variable for new data.
                    System.out.print(log);
                    log = "";
                }
            }
        }
    });
    thread.start();
    started = true;
}
}

Usage: LogUtil.println("This is a string");

Adding iOS UITableView HeaderView (not section header)

UITableView has a tableHeaderView property. Set that to whatever view you want up there.

Use a new UIView as a container, add a text label and an image view to that new UIView, then set tableHeaderView to the new view.

For example, in a UITableViewController:

-(void)viewDidLoad
{
     // ...
     UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(XXX, YYY, XXX, YYY)];
     UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(XXX, YYY, XXX, YYY)];
     [headerView addSubview:imageView];
     UILabel *labelView = [[UILabel alloc] initWithFrame:CGRectMake(XXX, YYY, XXX, YYY)];
     [headerView addSubview:labelView];
     self.tableView.tableHeaderView = headerView;
     [imageView release];
     [labelView release];
     [headerView release];
     // ...
} 

Add colorbar to existing axis

This technique is usually used for multiple axis in a figure. In this context it is often required to have a colorbar that corresponds in size with the result from imshow. This can be achieved easily with the axes grid tool kit:

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable

data = np.arange(100, 0, -1).reshape(10, 10)

fig, ax = plt.subplots()
divider = make_axes_locatable(ax)
cax = divider.append_axes('right', size='5%', pad=0.05)

im = ax.imshow(data, cmap='bone')

fig.colorbar(im, cax=cax, orientation='vertical')
plt.show()

Image with proper colorbar in size

Difference between an API and SDK

How about... It's like if you wanted to install a home theatre system in your house. Using an API is like getting all the wires, screws, bits, and pieces. The possibilities are endless (constrained only by the pieces you receive), but sometimes overwhelming. An SDK is like getting a kit. You still have to put it together, but it's more like getting pre-cut pieces and instructions for an IKEA bookshelf than a box of screws.

Spark dataframe: collect () vs select ()

Select is a transformation, not an action, so it is lazily evaluated (won't actually do the calculations just map the operations). Collect is an action.

Try:

df.limit(20).collect()

PHP preg_replace special characters

If you by writing "non letters and numbers" exclude more than [A-Za-z0-9] (ie. considering letters like åäö to be letters to) and want to be able to accurately handle UTF-8 strings \p{L} and \p{N} will be of aid.

  1. \p{N} will match any "Number"
  2. \p{L} will match any "Letter Character", which includes
    • Lower case letter
    • Modifier letter
    • Other letter
    • Title case letter
    • Upper case letter

Documentation PHP: Unicode Character Properties


$data = "Thäre!wouldn't%bé#äny";

$new_data = str_replace  ("'", "", $data);
$new_data = preg_replace ('/[^\p{L}\p{N}]/u', '_', $new_data);

var_dump (
  $new_data
);

output

string(23) "Thäre_wouldnt_bé_äny"

Auto-redirect to another HTML page

One of these will work...

_x000D_
_x000D_
<head>_x000D_
  <meta http-equiv='refresh' content='0; URL=http://example.com/'>_x000D_
</head>
_x000D_
_x000D_
_x000D_

...or it can done with JavaScript:

_x000D_
_x000D_
window.location.href = 'https://example.com/';
_x000D_
_x000D_
_x000D_

In Windows cmd, how do I prompt for user input and use the result in another command?

Try this:

@echo off
set /p id="Enter ID: "

You can then use %id% as a parameter to another batch file like jstack %id%.

For example:

set /P id=Enter id: 
jstack %id% > jstack.txt

ImportError: No module named site on Windows

In my case, the issue was another site.py file, that was resolved earlier than the one from Python\Lib, due to PATH setting.

Environment: Windows 10 Pro, Python27.

My desktop has pgAdmin installed, which has file C:\Program Files (x86)\pgAdmin\venv\Lib\site.py. Because PATH environment variable had pdAdmin's home earlier than Python (apparently a bad idea in the first place), pgAdmin's site.py was found first.

All I had to do to fix the issue was to move pgAdmin's home later than Python, in PATH

Facebook user url by id

I've collected info together:

And finaly: it doen't work without additional Facebook permission check:(

Access to the path denied error in C#

If your problem persist with all those answers, try to change the file attribute to:

File.SetAttributes(yourfile, FileAttributes.Normal);

Removing duplicate objects with Underscore for Javascript

If you're looking to remove duplicates based on an id you could do something like this:

var res = [
  {id: 1, content: 'heeey'},
  {id: 2, content: 'woah'}, 
  {id: 1, content:'foo'},
  {id: 1, content: 'heeey'},
];
var uniques = _.map(_.groupBy(res,function(doc){
  return doc.id;
}),function(grouped){
  return grouped[0];
});

//uniques
//[{id: 1, content: 'heeey'},{id: 2, content: 'woah'}]

Countdown timer in React

You have to setState every second with the seconds remaining (every time the interval is called). Here's an example:

_x000D_
_x000D_
class Example extends React.Component {_x000D_
  constructor() {_x000D_
    super();_x000D_
    this.state = { time: {}, seconds: 5 };_x000D_
    this.timer = 0;_x000D_
    this.startTimer = this.startTimer.bind(this);_x000D_
    this.countDown = this.countDown.bind(this);_x000D_
  }_x000D_
_x000D_
  secondsToTime(secs){_x000D_
    let hours = Math.floor(secs / (60 * 60));_x000D_
_x000D_
    let divisor_for_minutes = secs % (60 * 60);_x000D_
    let minutes = Math.floor(divisor_for_minutes / 60);_x000D_
_x000D_
    let divisor_for_seconds = divisor_for_minutes % 60;_x000D_
    let seconds = Math.ceil(divisor_for_seconds);_x000D_
_x000D_
    let obj = {_x000D_
      "h": hours,_x000D_
      "m": minutes,_x000D_
      "s": seconds_x000D_
    };_x000D_
    return obj;_x000D_
  }_x000D_
_x000D_
  componentDidMount() {_x000D_
    let timeLeftVar = this.secondsToTime(this.state.seconds);_x000D_
    this.setState({ time: timeLeftVar });_x000D_
  }_x000D_
_x000D_
  startTimer() {_x000D_
    if (this.timer == 0 && this.state.seconds > 0) {_x000D_
      this.timer = setInterval(this.countDown, 1000);_x000D_
    }_x000D_
  }_x000D_
_x000D_
  countDown() {_x000D_
    // Remove one second, set state so a re-render happens._x000D_
    let seconds = this.state.seconds - 1;_x000D_
    this.setState({_x000D_
      time: this.secondsToTime(seconds),_x000D_
      seconds: seconds,_x000D_
    });_x000D_
    _x000D_
    // Check if we're at zero._x000D_
    if (seconds == 0) { _x000D_
      clearInterval(this.timer);_x000D_
    }_x000D_
  }_x000D_
_x000D_
  render() {_x000D_
    return(_x000D_
      <div>_x000D_
        <button onClick={this.startTimer}>Start</button>_x000D_
        m: {this.state.time.m} s: {this.state.time.s}_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
}_x000D_
_x000D_
ReactDOM.render(<Example/>, document.getElementById('View'));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="View"></div>
_x000D_
_x000D_
_x000D_

Why would someone use WHERE 1=1 AND <conditions> in a SQL clause?

Making "where 1=1" the standard for all your queries also makes it trivially easy to validate the sql by replacing it with where 1 = 0, handy when you have batches of commands/files.

Also makes it trivially easy to find the end of the end of the from/join section of any query. Even queries with sub-queries if properly indented.

how to include js file in php?

In your example you use the href attribute to tell where the JavaScript file can be found. This should be the src attribute:

?> <script type="text/javascript" src="file.js"></script> <?php

For more information see w3schools.

CSS list item width/height does not work

Declare the a element as display: inline-block and drop the width and height from the li element.

Alternatively, apply a float: left to the li element and use display: block on the a element. This is a bit more cross browser compatible, as display: inline-block is not supported in Firefox <= 2 for example.

The first method allows you to have a dynamically centered list if you give the ul element a width of 100% (so that it spans from left to right edge) and then apply text-align: center.

Use line-height to control the text's Y-position inside the element.

What is the pythonic way to detect the last element in a 'for' loop?

Just check if data is not the same as the last data in data_list (data_list[-1]).

for data in data_list:
    code_that_is_done_for_every_element
    if data != data_list[- 1]:
        code_that_is_done_between_elements

How to send a POST request using volley with string body?

You can refer to the following code (of course you can customize to get more details of the network response):

try {
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    String URL = "http://...";
    JSONObject jsonBody = new JSONObject();
    jsonBody.put("Title", "Android Volley Demo");
    jsonBody.put("Author", "BNK");
    final String requestBody = jsonBody.toString();

    StringRequest stringRequest = new StringRequest(Request.Method.POST, URL, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            Log.i("VOLLEY", response);
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Log.e("VOLLEY", error.toString());
        }
    }) {
        @Override
        public String getBodyContentType() {
            return "application/json; charset=utf-8";
        }

        @Override
        public byte[] getBody() throws AuthFailureError {
            try {
                return requestBody == null ? null : requestBody.getBytes("utf-8");
            } catch (UnsupportedEncodingException uee) {
                VolleyLog.wtf("Unsupported Encoding while trying to get the bytes of %s using %s", requestBody, "utf-8");
                return null;
            }
        }

        @Override
        protected Response<String> parseNetworkResponse(NetworkResponse response) {
            String responseString = "";
            if (response != null) {
                responseString = String.valueOf(response.statusCode);
                // can get more details such as response.headers
            }
            return Response.success(responseString, HttpHeaderParser.parseCacheHeaders(response));
        }
    };

    requestQueue.add(stringRequest);
} catch (JSONException e) {
    e.printStackTrace();
}

When use getOne and findOne methods Spring Data JPA

I had a similar problem understanding why JpaRespository.getOne(id) does not work and throw an error.

I went and change to JpaRespository.findById(id) which requires you to return an Optional.

This is probably my first comment on StackOverflow.

How to trust a apt repository : Debian apt-get update error public key is not available: NO_PUBKEY <id>

I had the same problem of "gpg: keyserver timed out" with a couple of different servers. Finally, it turned out that I didn't need to do that manually at all. On a Debian system, the simple solution which fixed it was just (as root or precede with sudo):

aptitude install debian-archive-keyring

In case it is some other keyring you need, check out

apt-cache search keyring | grep debian

My squeeze system shows all these:

debian-archive-keyring       - GnuPG archive keys of the Debian archive
debian-edu-archive-keyring   - GnuPG archive keys of the Debian Edu archive
debian-keyring               - GnuPG keys of Debian Developers
debian-ports-archive-keyring - GnuPG archive keys of the debian-ports archive
emdebian-archive-keyring     - GnuPG archive keys for the emdebian repository

How to read existing text files without defining path

If your application is a web service, Directory.CurrentDirectory doesn't work.

Use System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "yourFileName.txt")) instead.

Advantage of switch over if-else statement

while (true) != while (loop)

Probably the first one is optimised by the compiler, that would explain why the second loop is slower when increasing loop count.

Junit test case for database insert method with DAO and web service

This is one sample dao test using junit in spring project.

import java.util.List;

import junit.framework.Assert;

import org.jboss.tools.example.springmvc.domain.Member;
import org.jboss.tools.example.springmvc.repo.MemberDao;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.transaction.TransactionConfiguration;
import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:test-context.xml",
"classpath:/META-INF/spring/applicationContext.xml"})
@Transactional
@TransactionConfiguration(defaultRollback=true)
public class MemberDaoTest
{
    @Autowired
    private MemberDao memberDao;

    @Test
    public void testFindById()
    {
        Member member = memberDao.findById(0l);

        Assert.assertEquals("John Smith", member.getName());
        Assert.assertEquals("[email protected]", member.getEmail());
        Assert.assertEquals("2125551212", member.getPhoneNumber());
        return;
    }

    @Test
    public void testFindByEmail()
    {
        Member member = memberDao.findByEmail("[email protected]");

        Assert.assertEquals("John Smith", member.getName());
        Assert.assertEquals("[email protected]", member.getEmail());
        Assert.assertEquals("2125551212", member.getPhoneNumber());
        return;
    }

    @Test
    public void testRegister()
    {
        Member member = new Member();
        member.setEmail("[email protected]");
        member.setName("Jane Doe");
        member.setPhoneNumber("2125552121");

        memberDao.register(member);
        Long id = member.getId();
        Assert.assertNotNull(id);

        Assert.assertEquals(2, memberDao.findAllOrderedByName().size());
        Member newMember = memberDao.findById(id);

        Assert.assertEquals("Jane Doe", newMember.getName());
        Assert.assertEquals("[email protected]", newMember.getEmail());
        Assert.assertEquals("2125552121", newMember.getPhoneNumber());
        return;
    }

    @Test
    public void testFindAllOrderedByName()
    {
        Member member = new Member();
        member.setEmail("[email protected]");
        member.setName("Jane Doe");
        member.setPhoneNumber("2125552121");
        memberDao.register(member);

        List<Member> members = memberDao.findAllOrderedByName();
        Assert.assertEquals(2, members.size());
        Member newMember = members.get(0);

        Assert.assertEquals("Jane Doe", newMember.getName());
        Assert.assertEquals("[email protected]", newMember.getEmail());
        Assert.assertEquals("2125552121", newMember.getPhoneNumber());
        return;
    }
}

Get next / previous element using JavaScript?

Its quite simple. Try this instead:

let myReferenceDiv = document.getElementById('mydiv');
let prev = myReferenceDiv.previousElementSibling;
let next = myReferenceDiv.nextElementSibling;

PDOException “could not find driver”

I Fixed this issue on my Debian 6. Normally I just had installed php5-common package. After installation, you have to restart your web server (apache or nginx depending on which one you installed). Then I just do an lsof on the apache process id (lsof -p process_id) as followed :

sudo lsof -p 1399   #replace 1399 by your apache process id
apache2 1399 root  mem    REG  254,2    80352 227236 /usr/lib/php5/20090626/xmlrpc.so
apache2 1399 root  mem    REG  254,2   166496 227235 /usr/lib/php5/20090626/suhosin.so
apache2 1399 root  mem    REG  254,2    31120 227233 /usr/lib/php5/20090626/pdo_mysql.so
apache2 1399 root  mem    REG  254,2   100776 227216 /usr/lib/php5/20090626/pdo.so
apache2 1399 root  mem    REG  254,2   135864 227232 /usr/lib/php5/20090626/mysqli.so

As you can see above, the modules are installed on a file path not known or guided by common library path: /usr/lib/php5/20090626/. For your installation, it may be different, but only the path of pdo_mysql.so, pdo.so, mysqli.so. So, this is why Drupal or any other php engine couldn't find the library and shows that error: PDOException: could not find driver

I just don't know why it is installed on such a weird path, for me it's just a bug in the library package installation script in debian 6. I solved the issue by creating a symbolic for all the files under /usr/lib/php5/20090626/ to /usr/lib/php5/ with this command :

ln -s /usr/lib/php5/20090626/* /usr/lib/php5/

How to run vi on docker container?

Add the following line in your Dockerfile then rebuild the docker image.

RUN apt-get update && apt-get install -y vim

Validate SSL certificates with Python

Or simply make your life easier by using the requests library:

import requests
requests.get('https://somesite.com', cert='/path/server.crt', verify=True)

A few more words about its usage.

Can't open and lock privilege tables: Table 'mysql.user' doesn't exist

As suggested above, i had similar issue with mysql-5.7.18,
i did this in this way

1. Executed this command from "MYSQL_HOME\bin\mysqld.exe --initialize-insecure"
2. then started "MYSQL_HOME\bin\mysqld.exe"
3. Connect workbench to this localhost:3306 with username 'root'
4. then executed this query "SET PASSWORD FOR 'root'@'localhost' = 'root';"

password was also updated successfully.

How do I find an array item with TypeScript? (a modern, easier way)

Playing with the tsconfig.json You can also targeting es5 like this :

{
    "compilerOptions": {
        "experimentalDecorators": true,
        "module": "commonjs", 
        "target": "es5"
    }
    ...

Binding Listbox to List<object> in WinForms

There are two main routes here:

1: listBox1.DataSource = yourList;

Do any manipulation (Add/Delete) to yourList and Rebind.
Set DisplayMember and ValueMember to control what is shown.

2: listBox1.Items.AddRange(yourList.ToArray());

(or use a for-loop to do Items.Add(...))

You can control Display by overloading ToString() of the list objects or by implementing the listBox1.Format event.

Send HTTP GET request with header

Here's a code excerpt we're using in our app to set request headers. You'll note we set the CONTENT_TYPE header only on a POST or PUT, but the general method of adding headers (via a request interceptor) is used for GET as well.

/**
 * HTTP request types
 */
public static final int POST_TYPE   = 1;
public static final int GET_TYPE    = 2;
public static final int PUT_TYPE    = 3;
public static final int DELETE_TYPE = 4;

/**
 * HTTP request header constants
 */
public static final String CONTENT_TYPE         = "Content-Type";
public static final String ACCEPT_ENCODING      = "Accept-Encoding";
public static final String CONTENT_ENCODING     = "Content-Encoding";
public static final String ENCODING_GZIP        = "gzip";
public static final String MIME_FORM_ENCODED    = "application/x-www-form-urlencoded";
public static final String MIME_TEXT_PLAIN      = "text/plain";

private InputStream performRequest(final String contentType, final String url, final String user, final String pass,
    final Map<String, String> headers, final Map<String, String> params, final int requestType) 
            throws IOException {

    DefaultHttpClient client = HTTPClientFactory.newClient();

    client.getParams().setParameter(HttpProtocolParams.USER_AGENT, mUserAgent);

    // add user and pass to client credentials if present
    if ((user != null) && (pass != null)) {
        client.getCredentialsProvider().setCredentials(AuthScope.ANY, new UsernamePasswordCredentials(user, pass));
    }

    // process headers using request interceptor
    final Map<String, String> sendHeaders = new HashMap<String, String>();
    if ((headers != null) && (headers.size() > 0)) {
        sendHeaders.putAll(headers);
    }
    if (requestType == HTTPRequestHelper.POST_TYPE || requestType == HTTPRequestHelper.PUT_TYPE ) {
        sendHeaders.put(HTTPRequestHelper.CONTENT_TYPE, contentType);
    }
    // request gzip encoding for response
    sendHeaders.put(HTTPRequestHelper.ACCEPT_ENCODING, HTTPRequestHelper.ENCODING_GZIP);

    if (sendHeaders.size() > 0) {
        client.addRequestInterceptor(new HttpRequestInterceptor() {

            public void process(final HttpRequest request, final HttpContext context) throws HttpException,
                IOException {
                for (String key : sendHeaders.keySet()) {
                    if (!request.containsHeader(key)) {
                        request.addHeader(key, sendHeaders.get(key));
                    }
                }
            }
        });
    }

    //.... code omitted ....//

}

How to finish Activity when starting other activity in Android?

  1. Make your activity A in manifest file: launchMode = "singleInstance"
  2. When the user clicks new, do FirstActivity.fa.finish(); and call the new Intent.
  3. When the user clicks modify, call the new Intent or simply finish activity B.

AngularJS: How to make angular load script inside ng-include?

I tried using Google reCAPTCHA explicitly. Here is the example:

// put somewhere in your index.html
<script type="text/javascript">
var onloadCallback = function() {
  grecaptcha.render('your-recaptcha-element', {
    'sitekey' : '6Ldcfv8SAAAAAB1DwJTM6T7qcJhVqhqtss_HzS3z'
  });
};

//link function of Angularjs directive
link: function (scope, element, attrs) {
  ...
  var domElem = '<script src="https://www.google.com/recaptcha/api.js?onload=onloadCallback&render=explicit" async defer></script>';
  $('#your-recaptcha-element').append($compile(domElem)(scope));
}

ASP.NET Bundles how to disable minification

I combined a few answers given by others in this question to come up with another alternative solution.

Goal: To always bundle the files, to disable the JS and CSS minification in the event that <compilation debug="true" ... /> and to always apply a custom transformation to the CSS bundle.

My solution:

1) In web.config: <compilation debug="true" ... />

2) In the Global.asax Application_Start() method:

 protected void Application_Start() {
     ...
     BundleTable.EnableOptimizations = true; // Force bundling to occur

     // If the compilation node in web.config indicates debugging mode is enabled
     // then clear all transforms. I.e. disable Js and CSS minification.
     if (HttpContext.Current.IsDebuggingEnabled) {
         BundleTable.Bundles.ToList().ForEach(b => b.Transforms.Clear());
     }

      // Add a custom CSS bundle transformer. In my case the transformer replaces a
      // token in the CSS file with an AppConfig value representing the website URL
      // in the current environment. E.g. www.mydevwebsite in Dev and
      // www.myprodwebsite.com in Production.
      BundleTable.Bundles.ToList()
          .FindAll(x => x.GetType() == typeof(StyleBundle))
          .ForEach(b => b.Transforms.Add(new MyStyleBundleTransformer()));
     ...
}

formatFloat : convert float number to string

Try this

package main

import "fmt"
import "strconv"

func FloatToString(input_num float64) string {
    // to convert a float number to a string
    return strconv.FormatFloat(input_num, 'f', 6, 64)
}

func main() {
    fmt.Println(FloatToString(21312421.213123))
}

If you just want as many digits precision as possible, then the special precision -1 uses the smallest number of digits necessary such that ParseFloat will return f exactly. Eg

strconv.FormatFloat(input_num, 'f', -1, 64)

Personally I find fmt easier to use. (Playground link)

fmt.Printf("x = %.6f\n", 21312421.213123)

Or if you just want to convert the string

fmt.Sprintf("%.6f", 21312421.213123)

Fastest way to set all values of an array?

System.arraycopy is my answer. Please let me know is there any better ways. Thx

private static long[] r1 = new long[64];
private static long[][] r2 = new long[64][64];

/**Proved:
 * {@link Arrays#fill(long[], long[])} makes r2 has 64 references to r1 - not the answer;
 * {@link Arrays#fill(long[], long)} sometimes slower than deep 2 looping.<br/>
 */
private static void testFillPerformance() {
    SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
    System.out.println(sdf.format(new Date()));
    Arrays.fill(r1, 0l);

    long stamp0 = System.nanoTime();
    //      Arrays.fill(r2, 0l); -- exception
    long stamp1 = System.nanoTime();
    //      System.out.println(String.format("Arrays.fill takes %s nano-seconds.", stamp1 - stamp0));

    stamp0 = System.nanoTime();
    for (int i = 0; i < 64; i++) {
        for (int j = 0; j < 64; j++)
            r2[i][j] = 0l;
    }
    stamp1 = System.nanoTime();
    System.out.println(String.format("Arrays' 2-looping takes %s nano-seconds.", stamp1 - stamp0));

    stamp0 = System.nanoTime();
    for (int i = 0; i < 64; i++) {
        System.arraycopy(r1, 0, r2[i], 0, 64);
    }
    stamp1 = System.nanoTime();
    System.out.println(String.format("System.arraycopy looping takes %s nano-seconds.", stamp1 - stamp0));

    stamp0 = System.nanoTime();
    Arrays.fill(r2, r1);
    stamp1 = System.nanoTime();
    System.out.println(String.format("One round Arrays.fill takes %s nano-seconds.", stamp1 - stamp0));

    stamp0 = System.nanoTime();
    for (int i = 0; i < 64; i++)
        Arrays.fill(r2[i], 0l);
    stamp1 = System.nanoTime();
    System.out.println(String.format("Two rounds Arrays.fill takes %s nano-seconds.", stamp1 - stamp0));
}

12:33:18
Arrays' 2-looping takes 133536 nano-seconds.
System.arraycopy looping takes 22070 nano-seconds.
One round Arrays.fill takes 9777 nano-seconds.
Two rounds Arrays.fill takes 93028 nano-seconds.

12:33:38
Arrays' 2-looping takes 133816 nano-seconds.
System.arraycopy looping takes 22070 nano-seconds.
One round Arrays.fill takes 17042 nano-seconds.
Two rounds Arrays.fill takes 95263 nano-seconds.

12:33:51
Arrays' 2-looping takes 199187 nano-seconds.
System.arraycopy looping takes 44140 nano-seconds.
One round Arrays.fill takes 19555 nano-seconds.
Two rounds Arrays.fill takes 449219 nano-seconds.

12:34:16
Arrays' 2-looping takes 199467 nano-seconds.
System.arraycopy looping takes 42464 nano-seconds.
One round Arrays.fill takes 17600 nano-seconds.
Two rounds Arrays.fill takes 170971 nano-seconds.

12:34:26
Arrays' 2-looping takes 198907 nano-seconds.
System.arraycopy looping takes 24584 nano-seconds.
One round Arrays.fill takes 10616 nano-seconds.
Two rounds Arrays.fill takes 94426 nano-seconds.

Python, Pandas : write content of DataFrame into text File

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

import pandas as pd
import xlrd
import os

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

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

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

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

NodeJS w/Express Error: Cannot GET /

I was facing the same problem as mentioned in the question. The following steps solved my problem.

I upgraded the nodejs package link with following steps

  1. Clear NPM's cache:

    npm cache clean -f
    
  2. Install a little helper called 'n'

    npm install -g n  
    

Then I went to node.js website, downloaded the latest node js package, installed it, and my problem was solved.

Can I escape a double quote in a verbatim string literal?

For adding some more information, your example will work without the @ symbol (it prevents escaping with \), this way:

string foo = "this \"word\" is escaped!";

It will work both ways but I prefer the double-quote style for it to be easier working, for example, with filenames (with lots of \ in the string).

A more useful statusline in vim?

set statusline=%<%f%m\ \[%{&ff}:%{&fenc}:%Y]\ %{getcwd()}\ \ \[%{strftime('%Y/%b/%d\ %a\ %I:%M\ %p')}\]\ %=\ Line:%l\/%L\ Column:%c%V\ %P

This is mine, give as a suggestion

How to change collation of database, table, column?

You need to either convert each table individually:

ALTER TABLE mytable CONVERT TO CHARACTER SET utf8mb4 

(this will convert the columns just as well), or export the database with latin1 and import it back with utf8mb4.

Get the latest date from grouped MySQL data

try this:

SELECT model, date
FROM doc
WHERE date = (SELECT MAX(date)
FROM doc GROUP BY model LIMIT 0, 1)
GROUP BY model

How do I print the type or class of a variable in Swift?

SWIFT 5

With the latest release of Swift 3 we can get pretty descriptions of type names through the String initializer. Like, for example print(String(describing: type(of: object))). Where object can be an instance variable like array, a dictionary, an Int, a NSDate, an instance of a custom class, etc.

Here is my complete answer: Get class name of object as string in Swift

That question is looking for a way to getting the class name of an object as string but, also i proposed another way to getting the class name of a variable that isn't subclass of NSObject. Here it is:

class Utility{
    class func classNameAsString(obj: Any) -> String {
        //prints more readable results for dictionaries, arrays, Int, etc
        return String(describing: type(of: obj))
    }
}

I made a static function which takes as parameter an object of type Any and returns its class name as String :) .

I tested this function with some variables like:

    let diccionary: [String: CGFloat] = [:]
    let array: [Int] = []
    let numInt = 9
    let numFloat: CGFloat = 3.0
    let numDouble: Double = 1.0
    let classOne = ClassOne()
    let classTwo: ClassTwo? = ClassTwo()
    let now = NSDate()
    let lbl = UILabel()

and the output was:

  • diccionary is of type Dictionary
  • array is of type Array
  • numInt is of type Int
  • numFloat is of type CGFloat
  • numDouble is of type Double
  • classOne is of type: ClassOne
  • classTwo is of type: ClassTwo
  • now is of type: Date
  • lbl is of type: UILabel

Copying HTML code in Google Chrome's inspect element

using httrack software you can download all the website content in your local. httrack : http://www.httrack.com/

How to hide a div with jQuery?

If you want the element to keep its space then you need to use,

$('#myDiv').css('visibility','hidden')

If you dont want the element to retain its space, then you can use,

$('#myDiv').css('display','none')

or simply,

$('#myDiv').hide();

How to implement DrawerArrowToggle from Android appcompat v7 21 library

First, you should know now the android.support.v4.app.ActionBarDrawerToggle is deprecated.

You must replace that with android.support.v7.app.ActionBarDrawerToggle.

Here is my example and I use the new Toolbar to replace the ActionBar.

MainActivity.java

public class MainActivity extends ActionBarActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(mToolbar);
    DrawerLayout mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle(
        this,  mDrawerLayout, mToolbar,
        R.string.navigation_drawer_open, R.string.navigation_drawer_close
    );
    mDrawerLayout.setDrawerListener(mDrawerToggle);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);
    mDrawerToggle.syncState();
}

styles.xml

<style name="AppTheme" parent="Theme.AppCompat.Light">
    <item name="drawerArrowStyle">@style/DrawerArrowStyle</item>
</style>

<style name="DrawerArrowStyle" parent="Widget.AppCompat.DrawerArrowToggle">
    <item name="spinBars">true</item>
    <item name="color">@android:color/white</item>
</style>

You can read the documents on AndroidDocument#DrawerArrowToggle_spinBars

This attribute is the key to implement the menu-to-arrow animation.

public static int DrawerArrowToggle_spinBars

Whether bars should rotate or not during transition
Must be a boolean value, either "true" or "false".

So, you set this: <item name="spinBars">true</item>.

Then the animation can be presented.

Hope this can help you.

from list of integers, get number closest to a given value

I'll rename the function take_closest to conform with PEP8 naming conventions.

If you mean quick-to-execute as opposed to quick-to-write, min should not be your weapon of choice, except in one very narrow use case. The min solution needs to examine every number in the list and do a calculation for each number. Using bisect.bisect_left instead is almost always faster.

The "almost" comes from the fact that bisect_left requires the list to be sorted to work. Hopefully, your use case is such that you can sort the list once and then leave it alone. Even if not, as long as you don't need to sort before every time you call take_closest, the bisect module will likely come out on top. If you're in doubt, try both and look at the real-world difference.

from bisect import bisect_left

def take_closest(myList, myNumber):
    """
    Assumes myList is sorted. Returns closest value to myNumber.

    If two numbers are equally close, return the smallest number.
    """
    pos = bisect_left(myList, myNumber)
    if pos == 0:
        return myList[0]
    if pos == len(myList):
        return myList[-1]
    before = myList[pos - 1]
    after = myList[pos]
    if after - myNumber < myNumber - before:
       return after
    else:
       return before

Bisect works by repeatedly halving a list and finding out which half myNumber has to be in by looking at the middle value. This means it has a running time of O(log n) as opposed to the O(n) running time of the highest voted answer. If we compare the two methods and supply both with a sorted myList, these are the results:

$ python -m timeit -s "
from closest import take_closest
from random import randint
a = range(-1000, 1000, 10)" "take_closest(a, randint(-1100, 1100))"

100000 loops, best of 3: 2.22 usec per loop

$ python -m timeit -s "
from closest import with_min
from random import randint
a = range(-1000, 1000, 10)" "with_min(a, randint(-1100, 1100))"

10000 loops, best of 3: 43.9 usec per loop

So in this particular test, bisect is almost 20 times faster. For longer lists, the difference will be greater.

What if we level the playing field by removing the precondition that myList must be sorted? Let's say we sort a copy of the list every time take_closest is called, while leaving the min solution unaltered. Using the 200-item list in the above test, the bisect solution is still the fastest, though only by about 30%.

This is a strange result, considering that the sorting step is O(n log(n))! The only reason min is still losing is that the sorting is done in highly optimalized c code, while min has to plod along calling a lambda function for every item. As myList grows in size, the min solution will eventually be faster. Note that we had to stack everything in its favour for the min solution to win.

Java: How to check if object is null?

Drawable drawable = Common.getDrawableFromUrl(this, product.getMapPath());
if (drawable == null) {
    drawable = getRandomDrawable();
}

The equals() method checks for value equality, which means that it compares the contents of two objects. Since null is not an object, this crashes when trying to compare the contents of your object to the contents of null.

The == operator checks for reference equality, which means that it looks whether the two objects are actually the very same object. This does not require the objects to actually exist; two nonexistent objects (null references) are also equal.

How to check date of last change in stored procedure or function in SQL server

This is the correct solution for finding a function:

SELECT name, create_date, modify_date
FROM sys.objects
WHERE type = 'fn'
AND name = 'fn_NAME'

How to prevent a dialog from closing when a button is clicked

For pre API 8 i solved the problem using a boolean flag, a dismiss listener and calling dialog.show again if in case the content of the editText wasn´t correct. Like this:

case ADD_CLIENT:
        LayoutInflater factoryClient = LayoutInflater.from(this);
        final View EntryViewClient = factoryClient.inflate(
                R.layout.alert_dialog_add_client, null);

        EditText ClientText = (EditText) EntryViewClient
                .findViewById(R.id.client_edit);

        AlertDialog.Builder builderClient = new AlertDialog.Builder(this);
        builderClient
                .setTitle(R.string.alert_dialog_client)
                .setCancelable(false)
                .setView(EntryViewClient)
                .setPositiveButton("Save",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,
                                    int whichButton) {
                                EditText newClient = (EditText) EntryViewClient
                                        .findViewById(R.id.client_edit);
                                String newClientString = newClient
                                        .getText().toString();
                                if (checkForEmptyFields(newClientString)) {
                                    //If field is empty show toast and set error flag to true;
                                    Toast.makeText(getApplicationContext(),
                                            "Fields cant be empty",
                                            Toast.LENGTH_SHORT).show();
                                    add_client_error = true;
                                } else {
                                    //Here save the info and set the error flag to false
                                    add_client_error = false;
                                }
                            }
                        })
                .setNegativeButton("Cancel",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,
                                    int id) {
                                add_client_error = false;
                                dialog.cancel();
                            }
                        });
        final AlertDialog alertClient = builderClient.create();
        alertClient.show();

        alertClient
                .setOnDismissListener(new DialogInterface.OnDismissListener() {

                    @Override
                    public void onDismiss(DialogInterface dialog) {
                        //If the error flag was set to true then show the dialog again
                        if (add_client_error == true) {
                            alertClient.show();
                        } else {
                            return;
                        }

                    }
                });
        return true;

Squash the first two commits in Git?

If you simply want to squash all commits into a single, initial commit, just reset the repository and amend the first commit:

git reset hash-of-first-commit
git add -A
git commit --amend

Git reset will leave the working tree intact, so everything is still there. So just add the files using git add commands, and amend the first commit with these changes. Compared to rebase -i you'll lose the ability to merge the git comments though.

Dots in URL causes 404 with ASP.NET mvc and IIS

MVC 5.0 Workaround.

Many of the suggested answers doesn't seem to work in MVC 5.0.

As the 404 dot problem in the last section can be solved by closing that section with a trailing slash, here's the little trick I use, clean and simple.

While keeping a convenient placeholder in your view:

@Html.ActionLink("Change your Town", "Manage", "GeoData", new { id = User.Identity.Name }, null)

add a little jquery/javascript to get the job done:

<script>
    $('a:contains("Change your Town")').on("click", function (event) {
        event.preventDefault();
        window.location.href = '@Url.Action("Manage", "GeoData", new { id = User.Identity.Name })' + "/";
    });</script>

please note the trailing slash, that is responsible for changing

http://localhost:51003/GeoData/Manage/[email protected]

into

http://localhost:51003/GeoData/Manage/[email protected]/

How should I tackle --secure-file-priv in MySQL?

For MacOS Mojave running MySQL 5.6.23 I had this problem with writing files, but not loading them. (Not seen with previous versions of Mac OS). As most of the answers to this question have been for other systems, I thought I would post the my.cnf file that cured this (and a socket problems too) in case it is of help to other Mac users. This is /etc/my.cnf

[client]
default-character-set=utf8

[mysqld]
character-set-server=utf8
secure-file-priv = ""
skip-external-locking

(The internationalization is irrelevant to the question.)

Nothing else required. Just turn the MySQL server off and then on again in Preferences (we are talking Mac) for this to take.

Capturing count from an SQL query

int count = 0;    
using (new SqlConnection connection = new SqlConnection("connectionString"))
{
    sqlCommand cmd = new SqlCommand("SELECT COUNT(*) FROM table_name", connection);
    connection.Open();
    count = (int32)cmd.ExecuteScalar();
}

Error "gnu/stubs-32.h: No such file or directory" while compiling Nachos source code

I was getting following error on a fedora 18 box:


1. /usr/include/gnu/stubs.h:7:27: fatal error: gnu/stubs-32.h: No such file or directory compilation terminated.

I Installed glibc.i686 and glibc-devel.i686, then compilation failed with following error:

2. /usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-redhat-linux/4.7.2/libgcc_s.so when searching for -lgcc_s /usr/bin/ld: cannot find -lgcc_s collect2: error: ld returned 1 exit status

Solution:

I installed (yum install) glibc.i686 glibc-devel.i386 and libgcc.i686 to get rid of the compilation issue.

Now compilation for 32 bit (-m32) works fine.

Why can't I reference my class library?

I faced this problem, and I solved it by closing visual studio, reopening visual studio, cleaning and rebuilding the solution. This worked for me.

How do I get this javascript to run every second?

Use setInterval:

$(function(){
setInterval(oneSecondFunction, 1000);
});

function oneSecondFunction() {
// stuff you want to do every second
}

Here's an article on the difference between setTimeout and setInterval. Both will provide the functionality you need, they just require different implementations.

Hidden features of Python

Objects in boolean context

Empty tuples, lists, dicts, strings and many other objects are equivalent to False in boolean context (and non-empty are equivalent to True).

empty_tuple = ()
empty_list = []
empty_dict = {}
empty_string = ''
empty_set = set()
if empty_tuple or empty_list or empty_dict or empty_string or empty_set:
  print 'Never happens!'

This allows logical operations to return one of it's operands instead of True/False, which is useful in some situations:

s = t or "Default value" # s will be assigned "Default value"
                         # if t is false/empty/none

Check if a number is a perfect square

This can be solved using the decimal module to get arbitrary precision square roots and easy checks for "exactness":

import math
from decimal import localcontext, Context, Inexact

def is_perfect_square(x):
    # If you want to allow negative squares, then set x = abs(x) instead
    if x < 0:
        return False

    # Create localized, default context so flags and traps unset
    with localcontext(Context()) as ctx:
        # Set a precision sufficient to represent x exactly; `x or 1` avoids
        # math domain error for log10 when x is 0
        ctx.prec = math.ceil(math.log10(x or 1)) + 1  # Wrap ceil call in int() on Py2
        # Compute integer square root; don't even store result, just setting flags
        ctx.sqrt(x).to_integral_exact()
        # If previous line couldn't represent square root as exact int, sets Inexact flag
        return not ctx.flags[Inexact]

For demonstration with truly huge values:

# I just kept mashing the numpad for awhile :-)
>>> base = 100009991439393999999393939398348438492389402490289028439083249803434098349083490340934903498034098390834980349083490384903843908309390282930823940230932490340983098349032098324908324098339779438974879480379380439748093874970843479280329708324970832497804329783429874329873429870234987234978034297804329782349783249873249870234987034298703249780349783497832497823497823497803429780324
>>> sqr = base ** 2
>>> sqr ** 0.5  # Too large to use floating point math
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: int too large to convert to float

>>> is_perfect_power(sqr)
True
>>> is_perfect_power(sqr-1)
False
>>> is_perfect_power(sqr+1)
False

If you increase the size of the value being tested, this eventually gets rather slow (takes close to a second for a 200,000 bit square), but for more moderate numbers (say, 20,000 bits), it's still faster than a human would notice for individual values (~33 ms on my machine). But since speed wasn't your primary concern, this is a good way to do it with Python's standard libraries.

Of course, it would be much faster to use gmpy2 and just test gmpy2.mpz(x).is_square(), but if third party packages aren't your thing, the above works quite well.

How to draw a custom UIView that is just a circle - iPhone app

Swift 3 - custom class, easy to reuse. It uses backgroundColor set in UI builder

import UIKit

@IBDesignable
class CircleBackgroundView: UIView {

    override func layoutSubviews() {
        super.layoutSubviews()
        layer.cornerRadius = bounds.size.width / 2
        layer.masksToBounds = true
    }

}

How can I make the contents of a fixed element scrollable only when it exceeds the height of the viewport?

You probably need an inner div. With css is:

.fixed {
   position: fixed;
   top: 0;
   left: 0;
   bottom: 0;
   overflow-y: auto;
   width: 200px; // your value
}
.inner {
   min-height: 100%;
}

A message body writer for Java type, class myPackage.B, and MIME media type, application/octet-stream, was not found

This can also happen if you've recently upgraded Ant. I was using Ant 1.8.4 on a project, and upgraded Ant to 1.9.4, and started to get this error when building a fat jar using Ant.

The solution for me was to downgrade back to Ant 1.8.4 for the command line and Eclipse using the process detailed here

SQL Stored Procedure: If variable is not null, update statement

Use a T-SQL IF:

IF @ABC IS NOT NULL AND @ABC != -1
    UPDATE [TABLE_NAME] SET XYZ=@ABC

Take a look at the MSDN docs.

C++ multiline string literal

// C++11. 
std::string index_html=R"html(
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>VIPSDK MONITOR</title>
    <meta http-equiv="refresh" content="10">
</head>
<style type="text/css">
</style>
</html>
)html";

Web Service vs WCF Service

This answer is based on an article that no longer exists:

Summary of article:

"Basically, WCF is a service layer that allows you to build applications that can communicate using a variety of communication mechanisms. With it, you can communicate using Peer to Peer, Named Pipes, Web Services and so on.

You can’t compare them because WCF is a framework for building interoperable applications. If you like, you can think of it as a SOA enabler. What does this mean?

Well, WCF conforms to something known as ABC, where A is the address of the service that you want to communicate with, B stands for the binding and C stands for the contract. This is important because it is possible to change the binding without necessarily changing the code. The contract is much more powerful because it forces the separation of the contract from the implementation. This means that the contract is defined in an interface, and there is a concrete implementation which is bound to by the consumer using the same idea of the contract. The datamodel is abstracted out."

... later ...

"should use WCF when we need to communicate with other communication technologies (e,.g. Peer to Peer, Named Pipes) rather than Web Service"

BeautifulSoup getting href

You can use find_all in the following way to find every a element that has an href attribute, and print each one:

from BeautifulSoup import BeautifulSoup

html = '''<a href="some_url">next</a>
<span class="class"><a href="another_url">later</a></span>'''

soup = BeautifulSoup(html)

for a in soup.find_all('a', href=True):
    print "Found the URL:", a['href']

The output would be:

Found the URL: some_url
Found the URL: another_url

Note that if you're using an older version of BeautifulSoup (before version 4) the name of this method is findAll. In version 4, BeautifulSoup's method names were changed to be PEP 8 compliant, so you should use find_all instead.


If you want all tags with an href, you can omit the name parameter:

href_tags = soup.find_all(href=True)

Keyboard shortcut to comment lines in Sublime Text 2

you need to replace "/" with "7", it works on non english keyboard layout.

General guidelines to avoid memory leaks in C++

One of the only examples about allocating and destroying in different places is thread creation (the parameter you pass). But even in this case is easy. Here is the function/method creating a thread:

struct myparams {
int x;
std::vector<double> z;
}

std::auto_ptr<myparams> param(new myparams(x, ...));
// Release the ownership in case thread creation is successfull
if (0 == pthread_create(&th, NULL, th_func, param.get()) param.release();
...

Here instead the thread function

extern "C" void* th_func(void* p) {
   try {
       std::auto_ptr<myparams> param((myparams*)p);
       ...
   } catch(...) {
   }
   return 0;
}

Pretty easyn isn't it? In case the thread creation fails the resource will be free'd (deleted) by the auto_ptr, otherwise the ownership will be passed to the thread. What if the thread is so fast that after creation it releases the resource before the

param.release();

gets called in the main function/method? Nothing! Because we will 'tell' the auto_ptr to ignore the deallocation. Is C++ memory management easy isn't it? Cheers,

Ema!

clear javascript console in Google Chrome

Press CTRL+L Shortcut to clear log, even if you have ticked Preserve log option.
Hope this helps.

How do I create a GUI for a windows application using C++?

I strongly prefer simply using Microsoft Visual Studio and writing a native Win32 app.

For a GUI as simple as the one that you describe, you could simply create a Dialog Box and use it as your main application window. The default application created by the Win32 Project wizard in Visual Studio actually pops a window, so you can replace that window with your Dialog Box and replace the WndProc with a similar (but simpler) DialogProc.

The question, then, is one of tools and cost. The Express Edition of Visual C++ does everything you want except actually create the Dialog Template resource. For this, you could either code it in the RC file by hand or in memory by hand. Related SO question: Windows API Dialogs without using resource files.

Or you could try one of the free resource editors that others have recommended.

Finally, the Visual Studio 2008 Standard Edition is a costlier option but gives you an integrated resource editor.

Difference between Encapsulation and Abstraction

Encapsulate hides variables or some implementation that may be changed so often in a class to prevent outsiders access it directly. They must access it via getter and setter methods.

Abstraction is used to hiding something too but in a higher degree(class, interface). Clients use an abstract class(or interface) do not care about who or which it was, they just need to know what it can do.

Git on Mac OS X v10.7 (Lion)

It's part of Xcode. You'll need to reinstall the developer tools.

SLF4J: Class path contains multiple SLF4J bindings

<!--<dependency>-->
     <!--<groupId>org.springframework.boot</groupId>-->
     <!--<artifactId>spring-boot-starter-log4j2</artifactId>-->
<!--</dependency>-->

I solved by delete this:spring-boot-starter-log4j2

How can I get a JavaScript stack trace when I throw an exception?

I had to investigate an endless recursion in smartgwt with IE11, so in order to investigate deeper, I needed a stack trace. The problem was, that I was unable to use the dev console, because the reproduction was more difficult that way.
Use the following in a javascript method:

try{ null.toString(); } catch(e) { alert(e.stack); }

grep a file, but show several surrounding lines?

I normally use

grep searchstring file -C n # n for number of lines of context up and down

Many of the tools like grep also have really great man files too. I find myself referring to grep's man page a lot because there is so much you can do with it.

man grep

Many GNU tools also have an info page that may have more useful information in addition to the man page.

info grep

When to favor ng-if vs. ng-show/ng-hide?

The answer is not simple:

It depends on the target machines (mobile vs desktop), it depends on the nature of your data, the browser, the OS, the hardware it runs on... you will need to benchmark if you really want to know.

It is mostly a memory vs computation problem ... as with most performance issues the difference can become significant with repeated elements (n) like lists, especially when nested (n x n, or worse) and also what kind of computations you run inside these elements:

  • ng-show: If those optional elements are often present (dense), like say 90% of the time, it may be faster to have them ready and only show/hide them, especially if their content is cheap (just plain text, nothing to compute or load). This consumes memory as it fills the DOM with hidden elements, but just show/hide something which already exists is likely to be a cheap operation for the browser.

  • ng-if: If on the contrary elements are likely not to be shown (sparse) just build them and destroy them in real time, especially if their content is expensive to get (computations/sorted/filtered, images, generated images). This is ideal for rare or 'on-demand' elements, it saves memory in terms of not filling the DOM but can cost a lot of computation (creating/destroying elements) and bandwidth (getting remote content). It also depends on how much you compute in the view (filtering/sorting) vs what you already have in the model (pre-sorted/pre-filtered data).

How to include route handlers in multiple files in Express?

This is possibly the most awesome stack overflow question/answer(s) ever. I love Sam's/Brad's solutions above. Thought I'd chime in with the async version that I implemented:

function loadRoutes(folder){
    if (!folder){
        folder = __dirname + '/routes/';
    }

    fs.readdir(folder, function(err, files){
        var l = files.length;
        for (var i = 0; i < l; i++){
            var file = files[i];
            fs.stat(file, function(err, stat){
                if (stat && stat.isDirectory()){
                    loadRoutes(folder + '/' + file + '/');
                } else {
                    var dot = file.lastIndexOf('.');
                    if (file.substr(dot + 1) === 'js'){
                        var name = file.substr(0, dot);

                        // I'm also passing argv here (from optimist)
                        // so that I can easily enable debugging for all
                        // routes.
                        require(folder + name)(app, argv);
                    }
                }
            });
        }
    });
}

My directory structure is a little different. I typically define routes in app.js (in the root directory of the project) by require-ing './routes'. Consequently, I'm skipping the check against index.js because I want to include that one as well.

EDIT: You can also put this in a function and call it recursively (I edited the example to show this) if you want to nest your routes in folders of arbitrary depth.

Deleting rows from parent and child tables

Two possible approaches.

  1. If you have a foreign key, declare it as on-delete-cascade and delete the parent rows older than 30 days. All the child rows will be deleted automatically.

  2. Based on your description, it looks like you know the parent rows that you want to delete and need to delete the corresponding child rows. Have you tried SQL like this?

      delete from child_table
          where parent_id in (
               select parent_id from parent_table
                    where updd_tms != (sysdate-30)
    

    -- now delete the parent table records

    delete from parent_table
    where updd_tms != (sysdate-30);
    

---- Based on your requirement, it looks like you might have to use PL/SQL. I'll see if someone can post a pure SQL solution to this (in which case that would definitely be the way to go).

declare
    v_sqlcode number;
    PRAGMA EXCEPTION_INIT(foreign_key_violated, -02291);
begin
    for v_rec in (select parent_id, child id from child_table
                         where updd_tms != (sysdate-30) ) loop

    -- delete the children
    delete from child_table where child_id = v_rec.child_id;

    -- delete the parent. If we get foreign key violation, 
    -- stop this step and continue the loop
    begin
       delete from parent_table
          where parent_id = v_rec.parent_id;
    exception
       when foreign_key_violated
         then null;
    end;
 end loop;
end;
/

Are there other whitespace codes like &nbsp for half-spaces, em-spaces, en-spaces etc useful in HTML?

There are codes for other space characters, and the codes as such work well, but the characters themselves are legacy character. They have been included into character sets only due to their presence in existing character data, rather than for use in new documents. For some combinations of font and browser version, they may cause a generic glyph of unrepresentable character to be shown. For details, check my page about Unicode spaces.

So using CSS is safer and lets you specify any desired amount of spacing, not just the specific widths of fixed-width spaces. If you just want to have added spacing around your h2 elements, as it seems to me, then setting padding on those elements (changing the value of the padding: 0 settings that you already have) should work fine.

OpenCV resize fails on large image with "error: (-215) ssize.area() > 0 in function cv::resize"

For me the following work-around worked:

  • split the array up into smaller sub arrays
  • resize the sub arrays
  • merge the sub arrays again

Here the code:

def split_up_resize(arr, res):
    """
    function which resizes large array (direct resize yields error (addedtypo))
    """

    # compute destination resolution for subarrays
    res_1 = (res[0], res[1]/2)
    res_2 = (res[0], res[1] - res[1]/2)

    # get sub-arrays
    arr_1 = arr[0 : len(arr)/2]
    arr_2 = arr[len(arr)/2 :]

    # resize sub arrays
    arr_1 = cv2.resize(arr_1, res_1, interpolation = cv2.INTER_LINEAR)
    arr_2 = cv2.resize(arr_2, res_2, interpolation = cv2.INTER_LINEAR)

    # init resized array
    arr = np.zeros((res[1], res[0]))

    # merge resized sub arrays
    arr[0 : len(arr)/2] = arr_1
    arr[len(arr)/2 :] = arr_2

    return arr

What is the difference between RTP or RTSP in a streaming server?

I hear your pain. I'm going through this right now (years later). From what I've learned, you can think of RTSP as a "VCR controller", the protocol allows you to specify which streams (presentations) you want to play, it will then send you a description of the media, and then you can use RTSP to play, stop, pause, and record the remote stream. The media itself goes over RTP. RTSP is normally implemented over a different socket or communication layer. Although it is simply a protocol, most often it's implemented by a server over a socket. For live streams, the RTSP stream you request is simply a name of a stream. It doesn't need to refer to a file on the server, the server's RTSP implementation can parse that stream, put together a live graph, and then provide the SDP (description) for that stream name. But, this is of course specific to the way the RTSP server has been implemented. For "live" streams, it's probably simpler to just use RTP, but you'll need a way to transfer the SDP from the RTP server to the client that wants to play that stream.

How to input a string from user into environment variable from batch file

A rather roundabout way, just for completeness:

 for /f "delims=" %i in ('type CON') do set inp=%i

Of course that requires ^Z as a terminator, and so the Johannes answer is better in all practical ways.

jQuery, simple polling example

function poll(){
    $("ajax.php", function(data){
        //do stuff  
    }); 
}

setInterval(function(){ poll(); }, 5000);

BATCH file asks for file or folder

Actually xcopy does not ask you if the original file exists, but if you want to put it in a new folder named Shapes.atc, or in the folder Support (which is what you want.

To prevent xcopy from asking this, just tell him the destination folder, so there's no ambiguity:

xcopy /s/y "J:\Old path\Shapes.atc" "C:\Documents and Settings\his name\Support"

If you want to change the filename in destination just use copy (which is more adapted than xcopy when copying files):

copy /y "J:\Old path\Shapes.atc" "C:\Documents and Settings\his name\Support\Shapes-new.atc

only integers, slices (`:`), ellipsis (`...`), numpy.newaxis (`None`) and integer or boolean arrays are valid indices

I believe your problem is this: in your while loop, n is divided by 2, but never cast as an integer again, so it becomes a float at some point. It is then added onto y, which is then a float too, and that gives you the warning.

How To Set Up GUI On Amazon EC2 Ubuntu server

For Ubuntu 16.04

1) Install packages

$ sudo apt update;sudo apt install --no-install-recommends ubuntu-desktop
$ sudo apt install gnome-panel gnome-settings-daemon metacity nautilus gnome-terminal vnc4server

2) Edit /usr/bin/vncserver file and modify as below

Find this line

"# exec /etc/X11/xinit/xinitrc\n\n".

And add these lines below.

"gnome-session &\n".
"gnome-panel &\n".
"gnome-settings-daemon &\n".
"metacity &\n".
"nautilus &\n".
"gnome-terminal &\n".

3) Create VNC password and vnc session for the user using "vncserver" command.

lonely@ubuntu:~$ vncserver
You will require a password to access your desktops.
Password:
Verify:
xauth: file /home/lonely/.Xauthority does not exist
New 'ubuntu:1 (lonely)' desktop is ubuntu:1
Creating default startup script /home/lonely/.vnc/xstartup
Starting applications specified in /home/lonely/.vnc/xstartup
Log file is /home/lonely/.vnc/ubuntu:1.log

Now you can access GUI using IP/Domain and port 1

stackoverflow.com:1

Tested on AWS and digital ocean .

For AWS, you have to allow port 5901 on firewall

To kill session

$ vncserver -kill :1

Refer:

https://linode.com/docs/applications/remote-desktop/install-vnc-on-ubuntu-16-04/

Refer this guide to create permanent sessions as service

http://www.krizna.com/ubuntu/enable-remote-desktop-ubuntu-16-04-vnc/

How to install MySQLdb package? (ImportError: No module named setuptools)

well installing C compiler or GCC didn't work but I found a way to successfully install mysqldb package

kindly follow Mike schrieb's (Thanks to him) instructions here . In my case, I used setuptools-0.6c11-py2.7.egg and setuptools-0.6c11 . Then download the executable file here then install that file. hope it helps :)

Remove an item from array using UnderscoreJS

Use can use plain JavaScript's Array#filter method like this:

_x000D_
_x000D_
var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];_x000D_
_x000D_
var filteredArr = arr.filter(obj => obj.id != 3);_x000D_
_x000D_
console.log(filteredArr);
_x000D_
_x000D_
_x000D_

Or, use Array#reduce and Array#concat methods like this:

_x000D_
_x000D_
var arr = [{id:1,name:'a'},{id:2,name:'b'},{id:3,name:'c'}];_x000D_
_x000D_
var reducedArr = arr.reduce((accumulator, currObj) => {_x000D_
  return (currObj.id != 3) ? accumulator.concat(currObj) : accumulator;_x000D_
}, []);_x000D_
_x000D_
console.log(reducedArr);
_x000D_
_x000D_
_x000D_

NOTE:

  • Both of these are pure functional approach (i.e. they don't modify the existing array).
  • No, external library is required in these approach (Vanilla JavaScript is enough).

How to create a DB link between two oracle instances

If you want to access the data in instance B from the instance A. Then this is the query, you can edit your respective credential.

CREATE DATABASE LINK dblink_passport
CONNECT TO xxusernamexx IDENTIFIED BY xxpasswordxx
USING
'(DESCRIPTION=
(ADDRESS=
(PROTOCOL=TCP)
(HOST=xxipaddrxx / xxhostxx )
(PORT=xxportxx))
(CONNECT_DATA=
(SID=xxsidxx)))';

After executing this query access table

SELECT * FROM tablename@dblink_passport;

You can perform any operation DML, DDL, DQL

ImportError: No module named tensorflow

I ran into the same issue. I simply updated my command to begin with python3 instead of python and it worked perfectly.

Using :focus to style outer div?

DIV elements can get focus if set the tabindex attribute. Here is the working example.

_x000D_
_x000D_
#focus-example > .extra {_x000D_
  display: none;_x000D_
}_x000D_
#focus-example:focus > .extra {_x000D_
  display: block;_x000D_
}
_x000D_
<div id="focus-example" tabindex="0">_x000D_
  <div>Focus me!</div>_x000D_
  <div class="extra">Hooray!</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

For more information about focus and blur, you can check out this article.

Update: And here is another example using focus to create a menu.

_x000D_
_x000D_
#toggleMenu:focus {_x000D_
  outline: none;_x000D_
}_x000D_
button:focus + .menu {_x000D_
  display: block;_x000D_
}_x000D_
.menu {_x000D_
  display: none;_x000D_
}_x000D_
.menu:focus {_x000D_
  display: none;_x000D_
}
_x000D_
<div id="toggleMenu" tabindex="0">_x000D_
  <button type="button">Menu</button>_x000D_
  <ul class="menu" tabindex="1">_x000D_
    <li>Home</li>_x000D_
    <li>About Me</li>_x000D_
    <li>Contacts</li>_x000D_
  </ul>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Jquery Ajax Loading image

Please note that: ajaxStart / ajaxStop is not working for ajax jsonp request (ajax json request is ok)

I am using jquery 1.7.2 while writing this.

here is one of the reference I found: http://bugs.jquery.com/ticket/8338

How do I get the path of the current executed file in Python?

You can't directly determine the location of the main script being executed. After all, sometimes the script didn't come from a file at all. For example, it could come from the interactive interpreter or dynamically generated code stored only in memory.

However, you can reliably determine the location of a module, since modules are always loaded from a file. If you create a module with the following code and put it in the same directory as your main script, then the main script can import the module and use that to locate itself.

some_path/module_locator.py:

def we_are_frozen():
    # All of the modules are built-in to the interpreter, e.g., by py2exe
    return hasattr(sys, "frozen")

def module_path():
    encoding = sys.getfilesystemencoding()
    if we_are_frozen():
        return os.path.dirname(unicode(sys.executable, encoding))
    return os.path.dirname(unicode(__file__, encoding))

some_path/main.py:

import module_locator
my_path = module_locator.module_path()

If you have several main scripts in different directories, you may need more than one copy of module_locator.

Of course, if your main script is loaded by some other tool that doesn't let you import modules that are co-located with your script, then you're out of luck. In cases like that, the information you're after simply doesn't exist anywhere in your program. Your best bet would be to file a bug with the authors of the tool.

C#: what is the easiest way to subtract time?

These can all be done with DateTime.Add(TimeSpan) since it supports positive and negative timespans.

DateTime original = new DateTime(year, month, day, 8, 0, 0);
DateTime updated = original.Add(new TimeSpan(5,0,0));

DateTime original = new DateTime(year, month, day, 17, 0, 0);
DateTime updated = original.Add(new TimeSpan(-2,0,0));

DateTime original = new DateTime(year, month, day, 17, 30, 0);
DateTime updated = original.Add(new TimeSpan(0,45,0));

Or you can also use the DateTime.Subtract(TimeSpan) method analogously.

C++ compile time error: expected identifier before numeric constant

Initializations with (...) in the class body is not allowed. Use {..} or = .... Unfortunately since the respective constructor is explicit and vector has an initializer list constructor, you need a functional cast to call the wanted constructor

vector<string> name = decltype(name)(5);
vector<int> val = decltype(val)(5,0);

As an alternative you can use constructor initializer lists

 Attribute():name(5), val(5, 0) {}

MySQL: Cloning a MySQL database on the same MySql instance

Best and easy way is to enter these commands in your terminal and set permissions to the root user. Works for me..!

:~$> mysqldump -u root -p db1 > dump.sql
:~$> mysqladmin -u root -p create db2
:~$> mysql -u root -p db2 < dump.sql

QLabel: set color of text and background

The ONLY thing that worked for me was html.

And I found it to be the far easier to do than any of the programmatic approaches.

The following code changes the text color based on a parameter passed by a caller.

enum {msg_info, msg_notify, msg_alert};
:
:
void bits::sendMessage(QString& line, int level)
{
    QTextCursor cursor = ui->messages->textCursor();
    QString alertHtml  = "<font color=\"DeepPink\">";
    QString notifyHtml = "<font color=\"Lime\">";
    QString infoHtml   = "<font color=\"Aqua\">";
    QString endHtml    = "</font><br>";

    switch(level)
    {
        case msg_alert:  line = alertHtml % line; break;
        case msg_notify: line = notifyHtml % line; break;
        case msg_info:   line = infoHtml % line; break;
        default:         line = infoHtml % line; break;
    }

    line = line % endHtml;
    ui->messages->insertHtml(line);
    cursor.movePosition(QTextCursor::End);
    ui->messages->setTextCursor(cursor);
}

C compile error: "Variable-sized object may not be initialized"

int size=5;
int ar[size ]={O};

/* This  operation gives an error -  
variable sized array may not be 
initialised.  Then just try this. 
*/
int size=5,i;
int ar[size];
for(i=0;i<size;i++)
{
    ar[i]=0;
}

Java Read Large Text File With 70million line of text

1) I am sure there is no difference speedwise, both use FileInputStream internally and buffering

2) You can take measurements and see for yourself

3) Though there's no performance benefits I like the 1.7 approach

try (BufferedReader br = Files.newBufferedReader(Paths.get("test.txt"), StandardCharsets.UTF_8)) {
    for (String line = null; (line = br.readLine()) != null;) {
        //
    }
}

4) Scanner based version

    try (Scanner sc = new Scanner(new File("test.txt"), "UTF-8")) {
        while (sc.hasNextLine()) {
            String line = sc.nextLine();
        }
        // note that Scanner suppresses exceptions
        if (sc.ioException() != null) {
            throw sc.ioException();
        }
    }

5) This may be faster than the rest

try (SeekableByteChannel ch = Files.newByteChannel(Paths.get("test.txt"))) {
    ByteBuffer bb = ByteBuffer.allocateDirect(1000);
    for(;;) {
        StringBuilder line = new StringBuilder();
        int n = ch.read(bb);
        // add chars to line
        // ...
    }
}

it requires a bit of coding but it can be really faster because of ByteBuffer.allocateDirect. It allows OS to read bytes from file to ByteBuffer directly, without copying

6) Parallel processing would definitely increase speed. Make a big byte buffer, run several tasks that read bytes from file into that buffer in parallel, when ready find first end of line, make a String, find next...

How do I run a bat file in the background from another bat file?

Since START is the only way to execute something in the background from a CMD script, I would recommend you keep using it. Instead of the /B modifier, try /MIN so the newly created window won't bother you. Also, you can set the priority to something lower with /LOW or /BELOWNORMAL, which should improve your system responsiveness.

Converting a Pandas GroupBy output from Series to DataFrame

I found this worked for me.

import numpy as np
import pandas as pd

df1 = pd.DataFrame({ 
    "Name" : ["Alice", "Bob", "Mallory", "Mallory", "Bob" , "Mallory"] , 
    "City" : ["Seattle", "Seattle", "Portland", "Seattle", "Seattle", "Portland"]})

df1['City_count'] = 1
df1['Name_count'] = 1

df1.groupby(['Name', 'City'], as_index=False).count()