Programs & Examples On #Libav

libav (or libav*) is the collective name of the FFmpeg libraries: libavcodec, libavformat, libavfilter, libavutil, etc. The name has also been appropriated by the Libav project–a fork of FFmpeg.

What are the differences and similarities between ffmpeg, libav, and avconv?

Confusing messages

These messages are rather misleading and understandably a source of confusion. Older Ubuntu versions used Libav which is a fork of the FFmpeg project. FFmpeg returned in Ubuntu 15.04 "Vivid Vervet".

The fork was basically a non-amicable result of conflicting personalities and development styles within the FFmpeg community. It is worth noting that the maintainer for Debian/Ubuntu switched from FFmpeg to Libav on his own accord due to being involved with the Libav fork.

The real ffmpeg vs the fake one

For a while both Libav and FFmpeg separately developed their own version of ffmpeg.

Libav then renamed their bizarro ffmpeg to avconv to distance themselves from the FFmpeg project. During the transition period the "not developed anymore" message was displayed to tell users to start using avconv instead of their counterfeit version of ffmpeg. This confused users into thinking that FFmpeg (the project) is dead, which is not true. A bad choice of words, but I can't imagine Libav not expecting such a response by general users.

This message was removed upstream when the fake "ffmpeg" was finally removed from the Libav source, but, depending on your version, it can still show up in Ubuntu because the Libav source Ubuntu uses is from the ffmpeg-to-avconv transition period.

In June 2012, the message was re-worded for the package libav - 4:0.8.3-0ubuntu0.12.04.1. Unfortunately the new "deprecated" message has caused additional user confusion.

Starting with Ubuntu 15.04 "Vivid Vervet", FFmpeg's ffmpeg is back in the repositories again.

libav vs Libav

To further complicate matters, Libav chose a name that was historically used by FFmpeg to refer to its libraries (libavcodec, libavformat, etc). For example the libav-user mailing list, for questions and discussions about using the FFmpeg libraries, is unrelated to the Libav project.

How to tell the difference

If you are using avconv then you are using Libav. If you are using ffmpeg you could be using FFmpeg or Libav. Refer to the first line in the console output to tell the difference: the copyright notice will either mention FFmpeg or Libav.

Secondly, the version numbering schemes differ. Each of the FFmpeg or Libav libraries contains a version.h header which shows a version number. FFmpeg will end in three digits, such as 57.67.100, and Libav will end in one digit such as 57.67.0. You can also view the library version numbers by running ffmpeg or avconv and viewing the console output.

If you want to use the real ffmpeg

Ubuntu 15.04 "Vivid Vervet" or newer

The real ffmpeg is in the repository, so you can install it with:

apt-get install ffmpeg

For older Ubuntu versions

Your options are:

These methods are non-intrusive, reversible, and will not interfere with the system or any repository packages.

Another possible option is to upgrade to Ubuntu 15.04 "Vivid Vervet" or newer and just use ffmpeg from the repository.

Also see

For an interesting blog article on the situation, as well as a discussion about the main technical differences between the projects, see The FFmpeg/Libav situation.

How to correctly write async method?

To get the behavior you want you need to wait for the process to finish before you exit Main(). To be able to tell when your process is done you need to return a Task instead of a void from your function, you should never return void from a async function unless you are working with events.

A re-written version of your program that works correctly would be

class Program {     static void Main(string[] args)     {         Debug.WriteLine("Calling DoDownload");         var downloadTask = DoDownloadAsync();         Debug.WriteLine("DoDownload done");         downloadTask.Wait(); //Waits for the background task to complete before finishing.      }      private static async Task DoDownloadAsync()     {         WebClient w = new WebClient();          string txt = await w.DownloadStringTaskAsync("http://www.google.com/");         Debug.WriteLine(txt);     } } 

Because you can not await in Main() I had to do the Wait() function instead. If this was a application that had a SynchronizationContext I would do await downloadTask; instead and make the function this was being called from async.

How do I insert an image in an activity with android studio?

since you followed the tutorial, I presume you have a screen that says Hello World.

that means you have some code in your layout xml that looks like this

<TextView        
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />

you want to display an image, so instead of TextView you want to have ImageView. and instead of a text attribute you want an src attribute, that links to your drawable resource

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/cool_pic"
/>

How to retry after exception?

A generic solution with a timeout:

import time

def onerror_retry(exception, callback, timeout=2, timedelta=.1):
    end_time = time.time() + timeout
    while True:
        try:
            yield callback()
            break
        except exception:
            if time.time() > end_time:
                raise
            elif timedelta > 0:
                time.sleep(timedelta)

Usage:

for retry in onerror_retry(SomeSpecificException, do_stuff):
    retry()

Android Studio: Gradle - build fails -- Execution failed for task ':dexDebug'

(This might be the wrong thread, as your problem seems more specific, but it's the thread that I found when searching for the issue's keywords)

Despite all good hints, the only thing that helped me, and that I'd like to share just in case, if everything else does not work :

Remove your .gradle directory in your home directory and have it re-build/re-downloaded for you by Android Studio.

Fixed all kinds of weird errors for me that neither were fixable by re-installing Android Studio itself nor the SDK.

Remote debugging a Java application

Answer covering Java >= 9:

For Java 9+, the JVM option needs a slight change by prefixing the address with the IP address of the machine hosting the JVM, or just *:

-agentlib:jdwp=transport=dt_socket,server=y,address=*:8000,suspend=n

This is due to a change noted in https://www.oracle.com/technetwork/java/javase/9-notes-3745703.html#JDK-8041435.

For Java < 9, the port number is enough to connect.

Operation is not valid due to the current state of the object, when I select a dropdown list

From http://codecorner.galanter.net/2012/06/04/solution-for-operation-is-not-valid-due-to-the-current-state-of-the-object-error/

Issue happens because Microsoft Security Update MS11-100 limits number of keys in Forms collection during HTTP POST request. To alleviate this problem you need to increase that number.

This can be done in your application Web.Config in the <appSettings> section (create the section directly under <configuration> if it doesn’t exist). Add 2 lines similar to the lines below to the section:

<add key="aspnet:MaxHttpCollectionKeys" value="2000" />
<add key="aspnet:MaxJsonDeserializerMembers" value="2000" />

The above example set the limit to 2000 keys. This will lift the limitation and the error should go away.

"Error 1067: The process terminated unexpectedly" when trying to start MySQL

I had the same error. I checked the error logs: C:\ProgramData\MySQL\MySQL Server 5.5\data\inf3rno-PC.err. According to them

170208  1:06:25 [Note] C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqld: Shutdown complete

170208  1:10:44 [Note] Plugin 'FEDERATED' is disabled.
170208  1:10:44 InnoDB: The InnoDB memory heap is disabled
170208  1:10:44 InnoDB: Mutexes and rw_locks use Windows interlocked functions
170208  1:10:44 InnoDB: Compressed tables use zlib 1.2.3
170208  1:10:44  InnoDB: Error: unable to create temporary file; errno: 2
170208  1:10:44 [ERROR] Plugin 'InnoDB' init function returned error.
170208  1:10:44 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
170208  1:10:44 [ERROR] Unknown/unsupported storage engine: INNODB
170208  1:10:44 [ERROR] Aborting

I think the important part here

170208  1:10:44  InnoDB: Error: unable to create temporary file; errno: 2

I changed the TMP and TEMP env variables from C:\Windows\Temp to %USERPROFILE%\AppData\Local\Temp yesterday, because I was unable to compress a directory and according to many post the solution is that. Now compression works, but mysql and apparently nod32 complains that they cannot create temporary files...

I added tmpdir=c:/server/mytmp to C:\Program Files\MySQL\MySQL Server 5.5\my.ini. And after that started the service again with services.msc. It is okay now.

So this can be a possible cause as well. I strongly suggest to everybody encountering this problem to check the error logs.

How do I make a request using HTTP basic authentication with PHP curl?

CURLOPT_USERPWD basically sends the base64 of the user:password string with http header like below:

Authorization: Basic dXNlcjpwYXNzd29yZA==

So apart from the CURLOPT_USERPWD you can also use the HTTP-Request header option as well like below with other headers:

$headers = array(
    'Content-Type:application/json',
    'Authorization: Basic '. base64_encode("user:password") // <---
);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

Plot multiple boxplot in one graph

Using base graphics, we can use at = to control box position , combined with boxwex = for the width of the boxes. The 1st boxplot statement creates a blank plot. Then add the 2 traces in the following two statements.

Note that in the following, we use df[,-1] to exclude the 1st (id) column from the values to plot. With different data frames, it may be necessary to change this to subset for whichever columns contain the data you want to plot.

boxplot(df[,-1], boxfill = NA, border = NA) #invisible boxes - only axes and plot area
boxplot(df[df$id=="Good", -1], xaxt = "n", add = TRUE, boxfill="red", 
  boxwex=0.25, at = 1:ncol(df[,-1]) - 0.15) #shift these left by -0.15
boxplot(df[df$id=="Bad", -1], xaxt = "n", add = TRUE, boxfill="blue", 
  boxwex=0.25, at = 1:ncol(df[,-1]) + 0.15) #shift to the right by +0.15

enter image description here

Some dummy data:

df <- data.frame(
  id = c(rep("Good",200), rep("Bad", 200)),
  F1 = c(rnorm(200,10,2), rnorm(200,8,1)),
  F2 = c(rnorm(200,7,1),  rnorm(200,6,1)),
  F3 = c(rnorm(200,6,2),  rnorm(200,9,3)),
  F4 = c(rnorm(200,12,3), rnorm(200,8,2)))

Should I initialize variable within constructor or outside constructor

The only problem I see with the first method is if you are planning to add more constructors. Then you will be repeating code and maintainability would suffer.

Java, How to implement a Shift Cipher (Caesar Cipher)

Two ways to implement a Caesar Cipher:

Option 1: Change chars to ASCII numbers, then you can increase the value, then revert it back to the new character.

Option 2: Use a Map map each letter to a digit like this.

A - 0
B - 1
C - 2
etc...

With a map you don't have to re-calculate the shift every time. Then you can change to and from plaintext to encrypted by following map.

Case-insensitive search in Rails model

Case-insensitive searching comes built-in with Rails. It accounts for differences in database implementations. Use either the built-in Arel library, or a gem like Squeel.

Datatable vs Dataset

A DataTable object represents tabular data as an in-memory, tabular cache of rows, columns, and constraints. The DataSet consists of a collection of DataTable objects that you can relate to each other with DataRelation objects.

What does the colon (:) operator do?

How would you write this for-each loop a different way so as to not incorporate the ":"?

Assuming that list is a Collection instance ...

public String toString() {
   String cardString = "";
   for (Iterator<PlayingCard> it = this.list.iterator(); it.hasNext(); /**/) {
      PlayingCard c = it.next();
      cardString = cardString + c + "\n";
   }
}

I should add the pedantic point that : is not an operator in this context. An operator performs an operation in an expression, and the stuff inside the ( ... ) in a for statement is not an expression ... according to the JLS.

How to serialize SqlAlchemy result to JSON?

For security reasons you should never return all the model's fields. I prefer to selectively choose them.

Flask's json encoding now supports UUID, datetime and relationships (and added query and query_class for flask_sqlalchemy db.Model class). I've updated the encoder as follows:

app/json_encoder.py

    from sqlalchemy.ext.declarative import DeclarativeMeta
    from flask import json


    class AlchemyEncoder(json.JSONEncoder):
        def default(self, o):
            if isinstance(o.__class__, DeclarativeMeta):
                data = {}
                fields = o.__json__() if hasattr(o, '__json__') else dir(o)
                for field in [f for f in fields if not f.startswith('_') and f not in ['metadata', 'query', 'query_class']]:
                    value = o.__getattribute__(field)
                    try:
                        json.dumps(value)
                        data[field] = value
                    except TypeError:
                        data[field] = None
                return data
            return json.JSONEncoder.default(self, o)

app/__init__.py

# json encoding
from app.json_encoder import AlchemyEncoder
app.json_encoder = AlchemyEncoder

With this I can optionally add a __json__ property that returns the list of fields I wish to encode:

app/models.py

class Queue(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    song_id = db.Column(db.Integer, db.ForeignKey('song.id'), unique=True, nullable=False)
    song = db.relationship('Song', lazy='joined')
    type = db.Column(db.String(20), server_default=u'audio/mpeg')
    src = db.Column(db.String(255), nullable=False)
    created_at = db.Column(db.DateTime, server_default=db.func.now())
    updated_at = db.Column(db.DateTime, server_default=db.func.now(), onupdate=db.func.now())

    def __init__(self, song):
        self.song = song
        self.src = song.full_path

    def __json__(self):
        return ['song', 'src', 'type', 'created_at']

I add @jsonapi to my view, return the resultlist and then my output is as follows:

[

{

    "created_at": "Thu, 23 Jul 2015 11:36:53 GMT",
    "song": 

        {
            "full_path": "/static/music/Audioslave/Audioslave [2002]/1 Cochise.mp3",
            "id": 2,
            "path_name": "Audioslave/Audioslave [2002]/1 Cochise.mp3"
        },
    "src": "/static/music/Audioslave/Audioslave [2002]/1 Cochise.mp3",
    "type": "audio/mpeg"
}

]

Should I URL-encode POST data?

curl will encode the data for you, just drop your raw field data into the fields array and tell it to "go".

How to drop a PostgreSQL database if there are active connections to it?

I noticed that postgres 9.2 now calls the column pid rather than procpid.

I tend to call it from the shell:

#!/usr/bin/env bash
# kill all connections to the postgres server
if [ -n "$1" ] ; then
  where="where pg_stat_activity.datname = '$1'"
  echo "killing all connections to database '$1'"
else
  echo "killing all connections to database"
fi

cat <<-EOF | psql -U postgres -d postgres 
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
${where}
EOF

Hope that is helpful. Thanks to @JustBob for the sql.

How to create a numeric vector of zero length in R

This isn't a very beautiful answer, but it's what I use to create zero-length vectors:

0[-1]     # numeric
""[-1]    # character
TRUE[-1]  # logical
0L[-1]    # integer

A literal is a vector of length 1, and [-1] removes the first element (the only element in this case) from the vector, leaving a vector with zero elements.

As a bonus, if you want a single NA of the respective type:

0[NA]     # numeric
""[NA]    # character
TRUE[NA]  # logical
0L[NA]    # integer

How do I get the directory from a file's full path?

You can use Path.GetDirectoryName and just pass in the filename.

MSDN Link

What is the purpose of the single underscore "_" variable in Python?

It's just a variable name, and it's conventional in python to use _ for throwaway variables. It just indicates that the loop variable isn't actually used.

how to set mongod --dbpath

You can set dbPath in the mongodb.conf file:

storage:
    dbPath: "/path/to/your/database/data/db"

It's a YAML-based configuration file format (since Mongodb 2.6 version), so pay attention no tabs only spaces, and space after ": "

usually this file located in the *nix systems here: /etc/mongodb.conf

So then just run

$ mongod -f /etc/mongodb.conf

And mongod process will start...

(on the Windows something like)

> C:\MongoDB\bin\mongod.exe -f C:\MongoDB\mongod.conf

Reset ID autoincrement ? phpmyadmin

I agree with rpd, this is the answer and can be done on a regular basis to clean up your id column that is getting bigger with only a few hundred rows of data, but maybe an id of 34444543!, as the data is deleted out regularly but id is incremented automatically.

ALTER TABLE users DROP id

The above sql can be run via sql query or as php. This will delete the id column.

Then re add it again, via the code below:

ALTER TABLE  `users` ADD `id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY FIRST

Place this in a piece of code that may get run maybe in an admin panel, so when anyone enters that page it will run this script that auto cleans your database, and tidys it.

LaTeX Optional Arguments

Here's my attempt, it doesn't follow your specs exactly though. Not fully tested, so be cautious.

\newcount\seccount

\def\sec{%
    \seccount0%
    \let\go\secnext\go
}

\def\secnext#1{%
    \def\last{#1}%
    \futurelet\next\secparse
}

\def\secparse{%
    \ifx\next\bgroup
        \let\go\secparseii
    \else
        \let\go\seclast
    \fi
    \go
}

\def\secparseii#1{%
    \ifnum\seccount>0, \fi
    \advance\seccount1\relax
    \last
    \def\last{#1}%
    \futurelet\next\secparse
}

\def\seclast{\ifnum\seccount>0{} and \fi\last}%

\sec{a}{b}{c}{d}{e}
% outputs "a, b, c, d and e"

\sec{a}
% outputs "a"

\sec{a}{b}
% outputs "a and b"

JavaScript module pattern with example

In order to approach to Modular design pattern, you need to understand these concept first:

Immediately-Invoked Function Expression (IIFE):

(function() {
      // Your code goes here 
}());

There are two ways you can use the functions. 1. Function declaration 2. Function expression.

Here are using function expression.

What is namespace? Now if we add the namespace to the above piece of code then

var anoyn = (function() {
}());

What is closure in JS?

It means if we declare any function with any variable scope/inside another function (in JS we can declare a function inside another function!) then it will count that function scope always. This means that any variable in outer function will be read always. It will not read the global variable (if any) with the same name. This is also one of the objective of using modular design pattern avoiding naming conflict.

var scope = "I am global";
function whatismyscope() {
    var scope = "I am just a local";
    function func() {return scope;}
    return func;
}
whatismyscope()()

Now we will apply these three concepts I mentioned above to define our first modular design pattern:

var modularpattern = (function() {
    // your module code goes here
    var sum = 0 ;

    return {
        add:function() {
            sum = sum + 1;
            return sum;
        },
        reset:function() {
            return sum = 0;    
        }  
    }   
}());
alert(modularpattern.add());    // alerts: 1
alert(modularpattern.add());    // alerts: 2
alert(modularpattern.reset());  // alerts: 0

jsfiddle for the code above.

The objective is to hide the variable accessibility from the outside world.

Hope this helps. Good Luck.

How to state in requirements.txt a direct github source

Since pip v1.5, (released Jan 1 2014: CHANGELOG, PR) you may also specify a subdirectory of a git repo to contain your module. The syntax looks like this:

pip install -e git+https://git.repo/some_repo.git#egg=my_subdir_pkg&subdirectory=my_subdir_pkg # install a python package from a repo subdirectory

Note: As a pip module author, ideally you'd probably want to publish your module in it's own top-level repo if you can. Yet this feature is helpful for some pre-existing repos that contain python modules in subdirectories. You might be forced to install them this way if they are not published to pypi too.

When does socket.recv(recv_size) return?

It'll have the same behavior as the underlying recv libc call see the man page for an official description of behavior (or read a more general description of the sockets api).

Colors in JavaScript console

In Chrome & Firefox (+31) you can add CSS in console.log messages:

_x000D_
_x000D_
console.log('%c Oh my heavens! ', 'background: #222; color: #bada55');
_x000D_
_x000D_
_x000D_

Console color example in Chrome

The same can be applied for adding multiple CSS to same command. syntax for multi coloring chrome console messages

References

How does one use glide to download an image into a bitmap?

This is what worked for me: https://github.com/bumptech/glide/wiki/Custom-targets#overriding-default-behavior

import com.bumptech.glide.Glide;
import com.bumptech.glide.request.transition.Transition;
import com.bumptech.glide.request.target.BitmapImageViewTarget;

...

Glide.with(yourFragment)
  .load("yourUrl")
  .asBitmap()
  .into(new BitmapImageViewTarget(yourImageView) {
    @Override
    public void onResourceReady(Bitmap bitmap, Transition<? super Bitmap> anim) {
        super.onResourceReady(bitmap, anim);
        Palette.generateAsync(bitmap, new Palette.PaletteAsyncListener() {  
            @Override
            public void onGenerated(Palette palette) {
                // Here's your generated palette
                Palette.Swatch swatch = palette.getDarkVibrantSwatch();
                int color = palette.getDarkVibrantColor(swatch.getTitleTextColor());
            }
        });
    }
});

How do I catch a PHP fatal (`E_ERROR`) error?

Log fatal errors using the register_shutdown_function, which requires PHP 5.2+:

register_shutdown_function( "fatal_handler" );

function fatal_handler() {
    $errfile = "unknown file";
    $errstr  = "shutdown";
    $errno   = E_CORE_ERROR;
    $errline = 0;

    $error = error_get_last();

    if($error !== NULL) {
        $errno   = $error["type"];
        $errfile = $error["file"];
        $errline = $error["line"];
        $errstr  = $error["message"];

        error_mail(format_error( $errno, $errstr, $errfile, $errline));
    }
}

You will have to define the error_mail and format_error functions. For example:

function format_error( $errno, $errstr, $errfile, $errline ) {
    $trace = print_r( debug_backtrace( false ), true );

    $content = "
    <table>
        <thead><th>Item</th><th>Description</th></thead>
        <tbody>
            <tr>
                <th>Error</th>
                <td><pre>$errstr</pre></td>
            </tr>
            <tr>
                <th>Errno</th>
                <td><pre>$errno</pre></td>
            </tr>
            <tr>
                <th>File</th>
                <td>$errfile</td>
            </tr>
            <tr>
                <th>Line</th>
                <td>$errline</td>
            </tr>
            <tr>
                <th>Trace</th>
                <td><pre>$trace</pre></td>
            </tr>
        </tbody>
    </table>";
    return $content;
}

Use Swift Mailer to write the error_mail function.

See also:

Set default value of an integer column SQLite

A column with default value:

CREATE TABLE <TableName>(
...
<ColumnName> <Type> DEFAULT <DefaultValue>
...
)

<DefaultValue> is a placeholder for a:

  • value literal
  • ( expression )

Examples:

Count INTEGER DEFAULT 0,
LastSeen TEXT DEFAULT (datetime('now'))

How to check if two words are anagrams

    /*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package Algorithms;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import javax.swing.JOptionPane;

/**
 *
 * @author Mokhtar
 */
public class Anagrams {

    //Write aprogram to check if two words are anagrams
    public static void main(String[] args) {
        Anagrams an=new Anagrams();
        ArrayList<String> l=new ArrayList<String>();
        String result=JOptionPane.showInputDialog("How many words to test anagrams");
        if(Integer.parseInt(result) >1)
        {    
            for(int i=0;i<Integer.parseInt(result);i++)
            {

                String word=JOptionPane.showInputDialog("Enter word #"+i);
                l.add(word);   
            }
            System.out.println(an.isanagrams(l));
        }
        else
        {
            JOptionPane.showMessageDialog(null, "Can not be tested, \nYou can test two words or more");
        }

    }

    private static String sortString( String w )
    {
        char[] ch = w.toCharArray();
        Arrays.sort(ch);
        return new String(ch);
    }

    public boolean isanagrams(ArrayList<String> l)
    {
        boolean isanagrams=true; 
        ArrayList<String> anagrams = null;
        HashMap<String, ArrayList<String>> map =  new HashMap<String, ArrayList<String>>();
        for(int i=0;i<l.size();i++)
            {
        String word = l.get(i);
        String sortedWord = sortString(word);
            anagrams = map.get( sortedWord );
        if( anagrams == null ) anagrams = new ArrayList<String>();
        anagrams.add(word);
        map.put(sortedWord, anagrams);
            }

            for(int h=0;h<l.size();h++)
            {
                if(!anagrams.contains(l.get(h)))
                {
                    isanagrams=false;
                    break;
                }
            }

            return isanagrams;
        //}
        }

}

Java: get greatest common divisor

/*
import scanner and instantiate scanner class;
declare your method with two parameters
declare a third variable;
set condition;
swap the parameter values if condition is met;
set second conditon based on result of first condition;
divide and assign remainder to the third variable;
swap the result;
in the main method, allow for user input;
Call the method;

*/
public class gcf {
    public static void main (String[]args){//start of main method
        Scanner input = new Scanner (System.in);//allow for user input
        System.out.println("Please enter the first integer: ");//prompt
        int a = input.nextInt();//initial user input
        System.out.println("Please enter a second interger: ");//prompt
        int b = input.nextInt();//second user input


       Divide(a,b);//call method
    }
   public static void Divide(int a, int b) {//start of your method

    int temp;
    // making a greater than b
    if (b > a) {
         temp = a;
         a = b;
         b = temp;
    }

    while (b !=0) {
        // gcd of b and a%b
        temp = a%b;
        // always make a greater than b
        a =b;
        b =temp;

    }
    System.out.println(a);//print to console
  }
}

Refused to display 'url' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'

I think You are trying to use the normal URL of video Like this :

Copying Direct URL from YouTube

That doesn't let you display the content on other domains.To Tackle this up , You should use the Copy Embed Code feature provided by the YouTube itself .Like this :

Copy Embed Code ( YouTube )

That would free you up from any issues .

For the above Scenario :

  • Go to Youtube Video

  • Copy Embed Code

  • Paste that into your Code ( Make sure you Escape all the " ( Inverted Commas) by \" .

Concatenate multiple node values in xpath

Here comes a solution with XSLT:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="//element3">
    <xsl:value-of select="element4/text()" />.<xsl:value-of select="element5/text()" />
</xsl:template>
</xsl:stylesheet>

Eclipse Indigo - Cannot install Android ADT Plugin

Thanks to all for the posts but unfortunatley none of the above solved my problem. Eventually what got it all working for me was to download eclipse indigo 3.7.2 and (this is very important) EXTRACT IT DIRECTLY INTO MY PROGRAMS FOLDER. Before I would extract it to my desktop and copy into the programs folder (C:\Program Files) but I would jus get an error message saying "The Eclipse executable launcher was unable to locate its companion shared library" when trying to run eclipse.

After extracting eclipse directly to my programs folder I ran it and added the ADT plugin the way reccomended in on the android site and so far all is working well :)

I'm on a windows 7 x64 machine and had jre-7u2-windows-x64.exe, jdk-7u2-windows-x64.exe and installer_r16-windows.exe installed before extracting eclipse.

I hope this can help someone else too :)

Is there a way to suppress JSHint warning for one given line?

Yes, there is a way. Two in fact. In October 2013 jshint added a way to ignore blocks of code like this:

// Code here will be linted with JSHint.
/* jshint ignore:start */
// Code here will be ignored by JSHint.
/* jshint ignore:end */
// Code here will be linted with JSHint.

You can also ignore a single line with a trailing comment like this:

ignoreThis(); // jshint ignore:line

Run javascript function when user finishes typing instead of on key up?

For passing parameters to your function along with ES6 syntax.

$(document).ready(() => {
    let timer = null;
     $('.classSelector').keydown(() => {
     clearTimeout(timer); 
     timer = setTimeout(() => foo('params'), 500);
  });
});

const foo = (params) => {
  console.log(`In foo ${params}`);
}

When should I use Async Controllers in ASP.NET MVC?

is it good to use async action everywhere in ASP.NET MVC?

As usual in programming, it depends. There is always a trade-off when going down a certain path.

async-await shines in places where you know you'll receiving concurrent requests to your service and you want to be able to scale out well. How does async-await help with scaling out? In the fact that when you invoke a async IO call synchronously, such as a network call or hitting your database, the current thread which is responsible for the execution is blocked waiting for the request to finish. When you use async-await, you enable the framework to create a state machine for you which makes sure that after the IO call is complete, your method continues executing from where it left off.

A thing to note is that this state machine has a subtle overhead. Making a method asynchronous does not make it execute faster, and that is an important factor to understand and a misconception many people have.

Another thing to take under consideration when using async-await is the fact that it is async all the way, meaning that you'll see async penetrate your entire call stack, top to buttom. This means that if you want to expose synchronous API's, you'll often find yourself duplicating a certain amount of code, as async and sync don't mix very well.

Shall I use async/await keywords when I want to query database (via EF/NHibernate/other ORM)?

If you choose to go down the path of using async IO calls, then yes, async-await will be a good choice, as more and more modern database providers expose async method implementing the TAP (Task Asynchronous Pattern).

How many times I can use await keywords to query database asynchronously in ONE single action method?

As many as you want, as long as you follow the rules stated by your database provider. There is no limit to the amount of async calls you can make. If you have queries which are independent of each other and can be made concurrently, you can spin a new task for each and use await Task.WhenAll to wait for both to complete.

How can I write a regex which matches non greedy?

The non-greedy ? works perfectly fine. It's just that you need to select dot matches all option in the regex engines (regexpal, the engine you used, also has this option) you are testing with. This is because, regex engines generally don't match line breaks when you use .. You need to tell them explicitly that you want to match line-breaks too with .

For example,

<img\s.*?>

works fine!

Check the results here.

Also, read about how dot behaves in various regex flavours.

Add borders to cells in POI generated Excel File

XSSF

BorderStyle

Use XSSFCellStyle.BORDER_MEDIUM or XSSFBorderFormatting.BORDER_MEDIUM (both enums refer to the same value):

XSSFCellStyle cellStyle = workbook.createCellStyle();

cellStyle.setBorderTop(XSSFCellStyle.BORDER_MEDIUM);
cellStyle.setBorderRight(XSSFCellStyle.BORDER_MEDIUM);
cellStyle.setBorderBottom(XSSFCellStyle.BORDER_MEDIUM);
cellStyle.setBorderLeft(XSSFCellStyle.BORDER_MEDIUM);

cell.setCellStyle(cellStyle);

BorderColor

Use setBorderColor(XSSFCellBorder.BorderSide.BOTTOM, XSSFColor) or setBottomBorderColor(XSSFColor) (equivalent for top, left, right):

XSSFCellStyle cellStyle = workbook.createCellStyle();
XSSFColor color = new XSSFColor(new java.awt.Color(128, 0, 128));

cellStyle.setTopBorderColor(color);
cellStyle.setRightBorderColor(color);
cellStyle.setBottomBorderColor(color);
cellStyle.setLeftBorderColor(color);

cell.setCellStyle(cellStyle);

How do you get current active/default Environment profile programmatically in Spring?

Extending User1648825's nice simple answer (I can't comment and my edit was rejected):

@Value("${spring.profiles.active}")
private String activeProfile;

This may throw an IllegalArgumentException if no profiles are set (I get a null value). This may be a Good Thing if you need it to be set; if not use the 'default' syntax for @Value, ie:

@Value("${spring.profiles.active:Unknown}")
private String activeProfile;

...activeProfile now contains 'Unknown' if spring.profiles.active could not be resolved

Padding or margin value in pixels as integer using jQuery

ok just to answer the original question:

you can get the padding as a usable integer like this:

var padding = parseInt($("myId").css("padding-top").replace("ems",""));

If you have defined another measurement like px just replace "ems" with "px". parseInt interprets the stringpart as a wrong value so its important to replace it with ... nothing.

SQL search multiple values in same field

Yes, you can use SQL IN operator to search multiple absolute values:

SELECT name FROM products WHERE name IN ( 'Value1', 'Value2', ... );

If you want to use LIKE you will need to use OR instead:

SELECT name FROM products WHERE name LIKE '%Value1' OR name LIKE '%Value2';

Using AND (as you tried) requires ALL conditions to be true, using OR requires at least one to be true.

Creating executable files in Linux

Make file executable:

chmod +x file

Find location of perl:

which perl

This should return something like

/bin/perl sometimes /usr/local/bin

Then in the first line of your script add:

#!"path"/perl with path from above e.g.

#!/bin/perl

Then you can execute the file

./file

There may be some issues with the PATH, so you may want to change that as well ...

Convert a object into JSON in REST service by Spring MVC

Another simple solution is to add jackson-databind dependency in POM.

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.1</version>
    </dependency>

Keep Rest of the code as it is.

Can you nest html forms?

Although the question is pretty old and I agree with the @everyone that nesting of form is not allowed in HTML

But this something all might want to see this

where you can hack(I'm calling it a hack since I'm sure this ain't legitimate) html to allow browser to have nested form

<form id="form_one" action="http://apple.com">
  <div>
    <div>
        <form id="form_two" action="/">
            <!-- DUMMY FORM TO ALLOW BROWSER TO ACCEPT NESTED FORM -->
      </form>
    </div>
      <br/>
    <div>
      <form id="form_three" action="http://www.linuxtopia.org/">
          <input type='submit' value='LINUX TOPIA'/>
      </form>
    </div>
      <br/>

    <div>
      <form id="form_four" action="http://bing.com">
          <input type='submit' value='BING'/>
      </form>
    </div>
      <br/>  
    <input type='submit' value='Apple'/>
  </div>  
</form>

JS FIDDLE LINK

http://jsfiddle.net/nzkEw/10/

How to throw an exception in C?

C doesn't support exceptions. You can try compiling your C code as C++ with Visual Studio or G++ and see if it'll compile as-is. Most C applications will compile as C++ without major changes, and you can then use the try... catch syntax.

Convert byte slice to io.Reader

To get a type that implements io.Reader from a []byte slice, you can use bytes.NewReader in the bytes package:

r := bytes.NewReader(byteData)

This will return a value of type bytes.Reader which implements the io.Reader (and io.ReadSeeker) interface.

Don't worry about them not being the same "type". io.Reader is an interface and can be implemented by many different types. To learn a little bit more about interfaces in Go, read Effective Go: Interfaces and Types.

What should every programmer know about security?

Security is a process, not a product.

Many seem to forget about this obvious matter of fact.

Check the current number of connections to MongoDb

You can just use

db.serverStatus().connections

Also, this function can help you spot the IP addresses connected to your Mongo DB

db.currentOp(true).inprog.forEach(function(x) { print(x.client) })

python for increment inner loop

You might just be better of using while loops rather than for loops for this. I translated your code directly from the java code.

str1 = "ababa"
str2 = "aba"
i = 0

while i < len(str1):
  j = 0
  while j < len(str2):
    if not str1[i+j] == str1[j]:
      break
    if j == (len(str2) -1):
      i += len(str2)
    j+=1  
  i+=1

PHP sessions default timeout

http://php.net/session.gc-maxlifetime

session.gc_maxlifetime = 1440
(1440 seconds = 24 minutes)

Git - Pushing code to two remotes

To send to both remote with one command, you can create a alias for it:

git config alias.pushall '!git push origin devel && git push github devel'

With this, when you use the command git pushall, it will update both repositories.

Apache won't run in xampp

Note that this problem usually occure for two reasons:

1-Port 80 is busy.

2-Port 443 is busy.

For number one as the others said, you can kill Skype and SQL Serever Reporter from

Windows Task Manager>"Services" Tab>"Services..." Button.

But if it dosen't worked, it's probably because of port 443, so try this one:

If you use VMware, go to

Windows Task Manager>"Services" Tab>"Services..." Button, and find "VMware Workstation Server" service, double click on it and press "Stop" button.

There is no need to stop other VMware's services.

Then again try to run Apache

Excel Formula: Count cells where value is date

Here is how I was able to trick Excel to count expired certifications in a list. I didn't have a set date, or date range, just current date. "TODAY()" doesn't work in these for Excel 2013. It sees it as text or condition, not the date value. So these previous didn't work for me. So the word problem/scenario: How many people are expired in this list?

Use: =IFERROR(D5-TODAY(),0) Where D5 is the date to be interrogated.

Then use: =IF(J5>=1,1,0) Where J5 is the cell where the first equation is producing either a positive or negative number. This set, I have hidden on the side of the visible sheet, then I just sum the total for the number of unexpired members.

Html- how to disable <a href>?

.disabledLink.disabled {pointer-events:none;}

That should do it hope I helped!

What is a typedef enum in Objective-C?

An enum declares a set of ordered values - the typedef just adds a handy name to this. The 1st element is 0 etc.

typedef enum {
Monday=1,
...
} WORKDAYS;

WORKDAYS today = Monday;

The above is just an enumeration of shapeType tags.

Append same text to every cell in a column in Excel

Put the text/value in the first cell, then copy the cell, mark the whole colum and 'paste' the copied text/value.

This works in Excel 97 - sorry no other version available on my side...

Row Offset in SQL Server

In SqlServer2005 you can do the following:

DECLARE @Limit INT
DECLARE @Offset INT
SET @Offset = 120000
SET @Limit = 10

SELECT 
    * 
FROM
(
   SELECT 
       row_number() 
   OVER 
      (ORDER BY column) AS rownum, column2, column3, .... columnX
   FROM   
     table
) AS A
WHERE 
 A.rownum BETWEEN (@Offset) AND (@Offset + @Limit-1) 

ORA-01008: not all variables bound. They are bound

I'd a similar problem in a legacy application, but de "--" was string parameter.

Ex.:

Dim cmd As New OracleCommand("INSERT INTO USER (name, address, photo) VALUES ('User1', '--', :photo)", oracleConnection)
Dim fs As IO.FileStream = New IO.FileStream("c:\img.jpg", IO.FileMode.Open)
Dim br As New IO.BinaryReader(fs)
cmd.Parameters.Add(New OracleParameter("photo", OracleDbType.Blob)).Value = br.ReadBytes(fs.Length)
cmd.ExecuteNonQuery() 'here throws ORA-01008

Changing address parameter value '--' to '00' or other thing, works.

nginx: how to create an alias url route?

server {
  server_name example.com;
  root /path/to/root;
  location / {
    # bla bla
  }
  location /demo {
    alias /path/to/root/production/folder/here;
  }
}

If you need to use try_files inside /demo you'll need to replace alias with a root and do a rewrite because of the bug explained here

Export MySQL data to Excel in PHP

PHPExcel is your friend. Very easy to use and works like a charm.

https://github.com/PHPOffice/PHPExcel

How do I clear inner HTML

Take a look at this. a clean and simple solution using jQuery.

http://jsfiddle.net/ma2Yd/

    <h1 onmouseover="go('The dog is in its shed')" onmouseout="clear()">lalala</h1>
    <div id="goy"></div>


    <script type="text/javascript">

    $(function() {
       $("h1").on('mouseover', function() {
          $("#goy").text('The dog is in its shed');
       }).on('mouseout', function() {
          $("#goy").text("");
       });
   });

Changing the Status Bar Color for specific ViewControllers using Swift in iOS8

Swift 4.2 solution with NavigationController

First Step:

Open your info.plist and insert a new key named "View controller-based status bar appearance" or UIViewControllerBasedStatusBarAppearance to YES to let each VC use their own status property.

Second Step

In each VC, override the preferredStatusBarStyle property like this :

override var preferredStatusBarStyle : UIStatusBarStyle {
    return .lightContent //.default for black style
}

Last step

Override the preferredStatusBarStyle property in your custom NavigationController class :

class NavigationController : UINavigationController {

override var preferredStatusBarStyle : UIStatusBarStyle {

    if let topVC = viewControllers.last {
        //return the status property of each VC, look at step 2
        return topVC.preferredStatusBarStyle  
    }

    return .default
}

Javascript - How to show escape characters in a string?

You have to escape the backslash, so try this:

str = "Hello\\nWorld";

Here are more escaped characters in Javascript.

Firebase onMessageReceived not called when app in background

The backend I'm working with is using Notification messages and not Data messages. So after reading all the answers I tried to retrieve the extras from the bundle of the intent that comes to the launched activity. But no matter which keys I tried to retrieve from getIntent().getExtras();, the value was always null.

However, I finally found a way to send data using Notification messages and retrieve it from the intent.

The key here is to add the data payload to the Notification message.

Example:

{
    "data": {
        "message": "message_body",
        "title": "message_title"
    },
    "notification": {
        "body": "test body",
        "title": "test title"
    },
    "to": "E4An.."
}

After you do this, you will be able to get your info in this way:

intent.getExtras().getString("title") will be message_title

and intent.getExtras().getString("message") will be message_body

Reference

NoSql vs Relational database

RDBMS focus more on relationship and NoSQL focus more on storage.

You can consider using NoSQL when your RDBMS reaches bottlenecks. NoSQL makes RDBMS more flexible.

Open firewall port on CentOS 7

Use this command to find your active zone(s):

firewall-cmd --get-active-zones

It will say either public, dmz, or something else. You should only apply to the zones required.

In the case of public try:

firewall-cmd --zone=public --add-port=2888/tcp --permanent

Then remember to reload the firewall for changes to take effect.

firewall-cmd --reload

Otherwise, substitute public for your zone, for example, if your zone is dmz:

firewall-cmd --zone=dmz --add-port=2888/tcp --permanent

Removing underline with href attribute

Add a style with the attribute text-decoration:none;:

There are a number of different ways of doing this.

Inline style:

<a href="xxx.html" style="text-decoration:none;">goto this link</a>

Inline stylesheet:

<html>
<head>
<style type="text/css">
   a {
      text-decoration:none;
   }
</style>
</head>
<body>
<a href="xxx.html">goto this link</a>
</body>
</html>

External stylesheet:

<html>
<head>
<link rel="Stylesheet" href="stylesheet.css" />
</head>
<body>
<a href="xxx.html">goto this link</a>
</body>
</html>

stylesheet.css:

a {
      text-decoration:none;
   }

C# LINQ find duplicates in List

You can do this:

var list = new[] {1,2,3,1,4,2};
var duplicateItems = list.Duplicates();

With these extension methods:

public static class Extensions
{
    public static IEnumerable<TSource> Duplicates<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> selector)
    {
        var grouped = source.GroupBy(selector);
        var moreThan1 = grouped.Where(i => i.IsMultiple());
        return moreThan1.SelectMany(i => i);
    }

    public static IEnumerable<TSource> Duplicates<TSource, TKey>(this IEnumerable<TSource> source)
    {
        return source.Duplicates(i => i);
    }

    public static bool IsMultiple<T>(this IEnumerable<T> source)
    {
        var enumerator = source.GetEnumerator();
        return enumerator.MoveNext() && enumerator.MoveNext();
    }
}

Using IsMultiple() in the Duplicates method is faster than Count() because this does not iterate the whole collection.

Converting String Array to an Integer Array

For Java 8 and higher:

    String[] test = {"1", "2", "3", "4", "5"};
    int[] ints = Arrays.stream(test).mapToInt(Integer::parseInt).toArray();

Passing enum or object through an intent (the best solution)

If you just want to send an enum you can do something like:

First declare an enum containing some value(which can be passed through intent):

 public enum MyEnum {
    ENUM_ZERO(0),
    ENUM_ONE(1),
    ENUM_TWO(2),
    ENUM_THREE(3);
    private int intValue;

    MyEnum(int intValue) {
        this.intValue = intValue;
    }

    public int getIntValue() {
        return intValue;
    }

    public static MyEnum getEnumByValue(int intValue) {
        switch (intValue) {
            case 0:
                return ENUM_ZERO;
            case 1:
                return ENUM_ONE;
            case 2:
                return ENUM_TWO;
            case 3:
                return ENUM_THREE;
            default:
                return null;
        }
    }
}

Then:

  intent.putExtra("EnumValue", MyEnum.ENUM_THREE.getIntValue());

And when you want to get it:

  NotificationController.MyEnum myEnum = NotificationController.MyEnum.getEnumByValue(intent.getIntExtra("EnumValue",-1);

Piece of cake!

Redraw datatables after using ajax to refresh the table content?

check fnAddData: https://legacy.datatables.net/ref

$(document).ready(function () {
  var table = $('#example').dataTable();
  var url = '/RESTApplicationTest/webresources/entity.person';
  $.get(url, function (data) {
    for (var i = 0; i < data.length; i++) {
      table.fnAddData([data[i].idPerson, data[i].firstname, data[i].lastname, data[i].email, data[i].phone])
    }
  });
});

Spring Boot application in eclipse, the Tomcat connector configured to listen on port XXXX failed to start

On Windows:

To get started, open the command prompt by clicking on Start and then typing cmd. In the command window, go ahead and type in the following command:

netstat -a -n -o

In the command above, the -o parameter is what will add the PID to the end of the table. Press enter and you should see something like this:

enter image description here

Now to see the name of the process that is using that port, go to Task Manager by pressing CTRL + SHIFT + ESC and then click on the Process tab. In Windows 10, you should click on the Details tab.

By default, the task manager does not display the process ID, so you have to click on View and then Select Columns.

You might also need to look into services running in background. To do that right-click and select open services as shown below:

enter image description here

Hope it helps :)

How to have multiple conditions for one if statement in python

I am a little late to the party but I thought I'd share a way of doing it, if you have identical types of conditions, i.e. checking if all, any or at given amount of A_1=A_2 and B_1=B_2, this can be done in the following way:

cond_list_1=["1","2","3"]
cond_list_2=["3","2","1"]
nr_conds=1

if len([True for i, j in zip(cond_list_1, cond_list_2) if i == j])>=nr_conds:
    print("At least " + str(nr_conds) + " conditions are fullfilled")

if len([True for i, j in zip(cond_list_1, cond_list_2) if i == j])==len(cond_list_1):
    print("All conditions are fullfilled")

This means you can just change in the two initial lists, at least for me this makes it easier.

'ssh-keygen' is not recognized as an internal or external command

2012:
ssh-keygen.exe is part of msysgit:

 C:\path\to\msysgit1.7.11\bin\ssh-keygen.exe

if your %PATH% includes C:\path\to\msysgit1.7.11\bin\, you will have ssh-keygen.


Update 2015:
ssh-keygen.exe is part of Git For Windows, whose releases include PortableGit-2.4.3.1-2nd-release-candidate-64-bit.7z

c:\path\to\PortableGit-2.4.3.1-2nd-release-candidate-64-bit\usr\bin\ssh-keygen.exe

That means the %PATH% must include c:\path\to\PortableGit-2.4.3.1-2nd-release-candidate-64-bit\usr\bin (without the ssh-keygen.exe)

As I explained before, Git for Windows will soon phase out msysgit.
I detailed in "Why is it that if you download Git 2.0 from the net, you always get a 1.9.4 installer package?" how this new version is based on the more recent msys2 project.

How to send characters in PuTTY serial communication only when pressing enter?

The settings you need are "Local echo" and "Line editing" under the "Terminal" category on the left.

To get the characters to display on the screen as you enter them, set "Local echo" to "Force on".

To get the terminal to not send the command until you press Enter, set "Local line editing" to "Force on".

PuTTY Line discipline options

Explanation:

From the PuTTY User Manual (Found by clicking on the "Help" button in PuTTY):

4.3.8 ‘Local echo’

With local echo disabled, characters you type into the PuTTY window are not echoed in the window by PuTTY. They are simply sent to the server. (The server might choose to echo them back to you; this can't be controlled from the PuTTY control panel.)

Some types of session need local echo, and many do not. In its default mode, PuTTY will automatically attempt to deduce whether or not local echo is appropriate for the session you are working in. If you find it has made the wrong decision, you can use this configuration option to override its choice: you can force local echo to be turned on, or force it to be turned off, instead of relying on the automatic detection.

4.3.9 ‘Local line editing’ Normally, every character you type into the PuTTY window is sent immediately to the server the moment you type it.

If you enable local line editing, this changes. PuTTY will let you edit a whole line at a time locally, and the line will only be sent to the server when you press Return. If you make a mistake, you can use the Backspace key to correct it before you press Return, and the server will never see the mistake.

Since it is hard to edit a line locally without being able to see it, local line editing is mostly used in conjunction with local echo (section 4.3.8). This makes it ideal for use in raw mode or when connecting to MUDs or talkers. (Although some more advanced MUDs do occasionally turn local line editing on and turn local echo off, in order to accept a password from the user.)

Some types of session need local line editing, and many do not. In its default mode, PuTTY will automatically attempt to deduce whether or not local line editing is appropriate for the session you are working in. If you find it has made the wrong decision, you can use this configuration option to override its choice: you can force local line editing to be turned on, or force it to be turned off, instead of relying on the automatic detection.

Putty sometimes makes wrong choices when "Auto" is enabled for these options because it tries to detect the connection configuration. Applied to serial line, this is a bit trickier to do.

How can I remove a child node in HTML using JavaScript?

You should probably use a JavaScript library to do things like this.

For example, MochiKit has a function removeElement, and jQuery has remove.

Removing black dots from li and ul

Relatable post

Those pesky black dots you are referencing to are called bullets.

They are pretty simple to remove, just add this line to your css:

ul {
    list-style-type: none;
}

Hope this helps

How to split a string content into an array of strings in PowerShell?

Remove the spaces from the original string and split on semicolon

$address = "[email protected]; [email protected]; [email protected]"
$addresses = $address.replace(' ','').split(';')

Or all in one line:

$addresses = "[email protected]; [email protected]; [email protected]".replace(' ','').split(';')

$addresses becomes:

@('[email protected]','[email protected]','[email protected]')

Accessing AppDelegate from framework?

If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?

Maven command to determine which settings.xml file Maven is using

If you are debugging and wasting time like me, this will give exact details including passwords. :P

mvn help:effective-settings -DshowPasswords=true

How to disable an Android button?

first in xml make the button as android:clickable="false"

<Button
        android:id="@+id/btn_send"
        android:clickable="false"/>

then in your code, inside oncreate() method set the button property as

btn.setClickable(true);

then inside the button click change the code into

btn.setClickable(false);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    btnSend = (Button) findViewById(R.id.btn_send);
    btnSend.setClickable(true);
    btnSend.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            btnSend.setClickable(false);

        }
    });
}

What is the meaning of "operator bool() const"

Another common use is for std containers to do equality comparison on key values inside custom objects

class Foo
{
    public: int val;
};

class Comparer { public:
bool operator () (Foo& a, Foo&b) const {
return a.val == b.val; 
};

class Blah
{
std::set< Foo, Comparer > _mySet;
};

Flutter does not find android sdk

flutter config --android-sdk F:\SDK

Where is localhost folder located in Mac or Mac OS X?

open the 'Finder' in Mac and Command+Shift+G and type in the path:/usr/local/zend/apache2/htdocs. path will open then create/paste your web page/application then check it on the browser.

Programmatic equivalent of default(Type)

Why do you say generics are out of the picture?

    public static object GetDefault(Type t)
    {
        Func<object> f = GetDefault<object>;
        return f.Method.GetGenericMethodDefinition().MakeGenericMethod(t).Invoke(null, null);
    }

    private static T GetDefault<T>()
    {
        return default(T);
    }

cartesian product in pandas

Use pd.MultiIndex.from_product as an index in an otherwise empty dataframe, then reset its index, and you're done.

a = [1, 2, 3]
b = ["a", "b", "c"]

index = pd.MultiIndex.from_product([a, b], names = ["a", "b"])

pd.DataFrame(index = index).reset_index()

out:

   a  b
0  1  a
1  1  b
2  1  c
3  2  a
4  2  b
5  2  c
6  3  a
7  3  b
8  3  c

How to run sql script using SQL Server Management Studio?

This website has a concise tutorial on how to use SQL Server Management Studio. As you will see you can open a "Query Window", paste your script and run it. It does not allow you to execute scripts by using the file path. However, you can do this easily by using the command line (cmd.exe):

sqlcmd -S .\SQLExpress -i SqlScript.sql

Where SqlScript.sql is the script file name located at the current directory. See this Microsoft page for more examples

Make HTML5 video poster be same size as video itself

You can use poster to show image instead of video on mobile device(or devices which doesn't support the video autoplay functionality). Because mobile devices not support video autoplay functionality.

<div id="wrap_video">
<video preload="preload" id="Video" autoplay="autoplay" loop="loop" poster="default.jpg">
<source src="Videos.mp4" type="video/mp4">
Your browser does not support the <code>video</code> tag.
</video>
</div>

Now you can just style the poster attribute which is inside the video tag for mobile device via media-query.

#wrap_video
{
width:480px;
height:360px;
position: relative;
} 
@media (min-width:360px) and (max-width:780px)
{
video[poster]
{
top:0 !important;
left:0 !important;
width:480px !important;
height:360px !important;
position: absolute !important;
}
}

Uncaught Error: SECURITY_ERR: DOM Exception 18 when I try to set a cookie

I was been getting that error in mobile safari when using ASP.NET MVC to return a FileResult with the overload that returns a file with a different file name than the original. So,

return File(returnFilePath, contentType, fileName);

would give the error in mobile safari, where as

return File(returnFilePath, contentType);

would not.

I don't even remember why I thought what I was doing was a good idea. Trying to be clever I guess.

How can I get the day of a specific date with PHP

$date = strtotime('2016-2-3');
$date = date('l', $date);
var_dump($date)

(i added format 'l' so it will return full name of day)

How do you change the colour of each category within a highcharts column chart?

Just add this...or you can change the colors as per your demand.

Highcharts.setOptions({
        colors: ['#811010', '#50B432', '#ED561B', '#DDDF00', '#24CBE5', '#64E572', '#FF9655', '#FFF263', '#6AF9C4'],
        plotOptions: {
            column: {
                colorByPoint: true
            }
        }

    });

How to create a blank/empty column with SELECT query in oracle?

I guess you will get ORA-01741: illegal zero-length identifier if you use the following

SELECT "" AS Contact  FROM Customers;

And if you use the following 2 statements, you will be getting the same null value populated in the column.

SELECT '' AS Contact FROM Customers; OR SELECT null AS Contact FROM Customers;

Eclipse Workspaces: What for and why?

I'll provide you with my vision of somebody who feels very uncomfortable in the Java world, which I assume is also your case.

What it is

A workspace is a concept of grouping together:

  1. a set of (somehow) related projects
  2. some configuration pertaining to all these projects
  3. some settings for Eclipse itself

This happens by creating a directory and putting inside it (you don't have to do it, it's done for you) files that manage to tell Eclipse these information. All you have to do explicitly is to select the folder where these files will be placed. And this folder doesn't need to be the same where you put your source code - preferentially it won't be.

Exploring each item above:

  1. a set of (somehow) related projects

Eclipse seems to always be opened in association with a particular workspace, i.e., if you are in a workspace A and decide to switch to workspace B (File > Switch Workspaces), Eclipse will close itself and reopen. All projects that were associated with workspace A (and were appearing in the Project Explorer) won't appear anymore and projects associated with workspace B will now appear. So it seems that a project, to be open in Eclipse, MUST be associated to a workspace.

Notice that this doesn't mean that the project source code must be inside the workspace. The workspace will, somehow, have a relation to the physical path of your projects in your disk (anybody knows how? I've looked inside the workspace searching for some file pointing to the projects paths, without success).

This way, a project can be inside more than 1 workspace at a time. So it seems good to keep your workspace and your source code separated.

  1. some configuration pertaining to all these projects

I heard that something, like the Java compiler version (like 1.7, e.g - I don't know if 'version' is the word here), is a workspace-level configuration. If you have several projects inside your workspace, and compile them inside of Eclipse, all of them will be compiled with the same Java compiler.

  1. some settings for Eclipse itself

Some things like your key bindings are stored at a workspace-level, also. So, if you define that ctrl+tab will switch tabs in a smart way (not stacking them), this will only be bound to your current workspace. If you want to use the same key binding in another workspace (and I think you want!), it seems that you have to export/import them between workspaces (if that's true, this IDE was built over some really strange premises). Here is a link on this.

It also seems that workspaces are not necessarily compatible between different Eclipse versions. This article suggests that you name your workspaces containing the name of the Eclipse version.

And, more important, once you pick a folder to be your workspace, don't touch any file inside there or you are in for some trouble.

How I think is a good way to use it

(actually, as I'm writing this, I don't know how to use this in a good way, that's why I was looking for an answer – that I'm trying to assemble here)

  1. Create a folder for your projects:
    /projects

  2. Create a folder for each project and group the projects' sub-projects inside of it:
    /projects/proj1/subproj1_1
    /projects/proj1/subproj1_2
    /projects/proj2/subproj2_1

  3. Create a separate folder for your workspaces:
    /eclipse-workspaces

  4. Create workspaces for your projects:
    /eclipse-workspaces/proj1
    /eclipse-workspaces/proj2

Make Bootstrap Popover Appear/Disappear on Hover instead of Click

The functionality, you described, can be easily achieved using the Bootstrap tooltip.

<button id="example1" data-toggle="tooltip">Tooltip on left</button>

Then call tooltip() function for the element.

$('#example1').tooltip();

http://getbootstrap.com/javascript/#tooltips

Where do I find the bashrc file on Mac?

On your Terminal:

  • Type cd ~/ to go to your home folder.

  • Type touch .bash_profile to create your new file.

  • Edit .bash_profile with your code editor (or you can just type open -e .bash_profile to open it in TextEdit).
  • Type . .bash_profile to reload .bash_profile and update any functions you add.

Get specific object by id from array of objects in AngularJS

I know I am too late to answer but it's always better to show up rather than not showing up at all :). ES6 way to get it:

$http.get("data/SampleData.json").then(response => {
let id = 'xyz';
let item = response.data.results.find(result => result.id === id);
console.log(item); //your desired item
});

What is default session timeout in ASP.NET?

The default is 20 minutes. http://msdn.microsoft.com/en-us/library/h6bb9cz9(v=vs.80).aspx

<sessionState 
mode="[Off|InProc|StateServer|SQLServer|Custom]"
timeout="number of minutes"
cookieName="session identifier cookie name"
cookieless=
     "[true|false|AutoDetect|UseCookies|UseUri|UseDeviceProfile]"
regenerateExpiredSessionId="[True|False]"
sqlConnectionString="sql connection string"
sqlCommandTimeout="number of seconds"
allowCustomSqlDatabase="[True|False]"
useHostingIdentity="[True|False]"
stateConnectionString="tcpip=server:port"
stateNetworkTimeout="number of seconds"
customProvider="custom provider name">
<providers>...</providers>
</sessionState>

How to write lists inside a markdown table?

If you want a no-bullet list (or any other non-standard usage) or more lines in a cell use <br />

| Event         | Platform      | Description |
| ------------- |-----------| -----:|
| `message_received`| `facebook-messenger`<br/>`skype`|

How to add a list item to an existing unordered list?

$("#content ul").append('<li><a href="/user/messages"><span class="tab">Message Center</span></a></li>');

Here is some feedback regarding Code Readability (shameless plug for a blog). http://coderob.wordpress.com/2012/02/02/code-readability

Consider separating the declaration of your new elements from the action of adding them to your UL.. It would look something like this:

var tabSpan = $('<span/>', {
    html: 'Message Center'
});
var messageCenterAnchor = $('<a/>', {
    href='/user/messages',
    html: tabSpan
});
var newListItem = $('<li/>', {
    html: messageCenterAnchor,
    "id": "myIDGoesHere"
});    // NOTE: you have to put quotes around "id" for IE..

$("content ul").append(newListItem);

Happy coding :)

Can a local variable's memory be accessed outside its scope?

In typical compiler implementations, you can think of the code as "print out the value of the memory block with adress that used to be occupied by a". Also, if you add a new function invocation to a function that constains a local int it's a good chance that the value of a (or the memory address that a used to point to) changes. This happens because the stack will be overwritten with a new frame containing different data.

However, this is undefined behaviour and you should not rely on it to work!

Setting std=c99 flag in GCC

How about alias gcc99= gcc -std=c99?

Difference between "this" and"super" keywords in Java

this is used to access the methods and fields of the current object. For this reason, it has no meaning in static methods, for example.

super allows access to non-private methods and fields in the super-class, and to access constructors from within the class' constructors only.

Create a tar.xz in one command

Quick Solution

tarxz() { tar cf - "$1" | xz -4e > "$1".tar.xz ; }
tarxz name_of_directory

(Notice, not name_of_directory/)


Using xz compression options

If you want to use compression options for xz, or if you are using tar on MacOS, you probably want to avoid the tar -cJf syntax.

According to man xz, the way to do this is:

tar cf - filename | xz -4e > filename.tar.xz

Because I liked Wojciech Adam Koszek's format, but not information:

  1. c creates a new archive for the specified files.
  2. f reads from a directory (best to put this second because -cf != -fc)
  3. - outputs to Standard Output
  4. | pipes output to the next command
  5. xz -4e calls xz with the -4e compression option. (equal to -4 --extreme)
  6. > filename.tar.xz directs the tarred and compressed file to filename.tar.xz

where -4e is, use your own compression options. I often use -k to --keep the original file and -9 for really heavy compression. -z to manually set xz to zip, though it defaults to zipping if not otherwise directed.

To uncompress and untar

To echo Rafael van Horn, to uncompress & untar (see note below):

xz -dc filename.tar.xz | tar x

Note: unlike Rafael's answer, use xz -dc instead of catxz. The docs recommend this in case you are using this for scripting. Best to have a habit of using -d or --decompress instead of unxz as well. However, if you must, using those commands from the command line is fine.

SDK location not found. Define location with sdk.dir in the local.properties file or with an ANDROID_HOME environment variable

i was thinking your setting.gradle file is missing. Copy this file another project and paste your project.It will work i think.

in setting.gradle file ,

include ':app'

thats all. Have a good day.

Is there a way to make HTML5 video fullscreen?

Yes. Well what happens with HTML5 video is that you just put the <video> tag and the browser will give it's own UI, and thus the ability for full screen viewing. It really makes life much better on us users to not have to see the "art" some developer playing with Flash could make :) It also adds consistency to the platform, which is nice.

Android marshmallow request permission?

If you're using AndroidX Activity 1.2.0 or AndroidX Fragment 1.3.0:

There are new Activity Result APIs that you can use to ask for permissions:

val launcher = registerForActivityResult(ActivityResultContracts.RequestPermission()) { isGranted ->
    if (isGranted) {
        // Permission granted. Do the tasks.
    }
}
launcher.launch(Manifest.permission.ACCESS_FINE_LOCATION)

Formatting PowerShell Get-Date inside string

You can use the -f operator

$a = "{0:D}" -f (get-date)
$a = "{0:dddd}" -f (get-date)

Spécificator    Type                                Example (with [datetime]::now)
d   Short date                                        26/09/2002
D   Long date                                       jeudi 26 septembre 2002
t   Short Hour                                      16:49
T   Long Hour                                       16:49:31
f   Date and hour                                   jeudi 26 septembre 2002 16:50
F   Long Date and hour                              jeudi 26 septembre 2002 16:50:51
g   Default Date                                    26/09/2002 16:52
G   Long default Date and hour                      26/09/2009 16:52:12
M   Month Symbol                                    26 septembre
r   Date string RFC1123                             Sat, 26 Sep 2009 16:54:50 GMT
s   Sortable string date                            2009-09-26T16:55:58
u   Sortable string date universal local hour       2009-09-26 16:56:49Z
U   Sortable string date universal GMT hour         samedi 26 septembre 2009 14:57:22 (oups)
Y   Year symbol                                     septembre 2002

Spécificator    Type                       Example      Output Example
dd              Jour                       {0:dd}       10
ddd             Name of the day            {0:ddd}      Jeu.
dddd            Complet name of the day    {0:dddd}     Jeudi
f, ff, …        Fractions of seconds       {0:fff}      932
gg, …           position                   {0:gg}       ap. J.-C.
hh              Hour two digits            {0:hh}       10
HH              Hour two digits (24 hours) {0:HH}       22
mm              Minuts 00-59               {0:mm}       38
MM              Month 01-12                {0:MM}       12
MMM             Month shortcut             {0:MMM}      Sep.
MMMM            complet name of the month  {0:MMMM}     Septembre
ss              Seconds 00-59              {0:ss}       46
tt              AM or PM                   {0:tt}       ““
yy              Years, 2 digits            {0:yy}       02
yyyy            Years                      {0:yyyy}     2002
zz              Time zone, 2 digits        {0:zz}       +02
zzz             Complete Time zone         {0:zzz}      +02:00
:               Separator                  {0:hh:mm:ss}     10:43:20
/               Separator                  {0:dd/MM/yyyy}   10/12/2002

What is two way binding?

Actually emberjs supports two-way binding, which is one of the most powerful feature for a javascript MVC framework. You can check it out where it mentioning binding in its user guide.

for emberjs, to create two way binding is by creating a new property with the string Binding at the end, then specifying a path from the global scope:

App.wife = Ember.Object.create({
  householdIncome: 80000
});

App.husband = Ember.Object.create({
  householdIncomeBinding: 'App.wife.householdIncome'
});

App.husband.get('householdIncome'); // 80000

// Someone gets raise.
App.husband.set('householdIncome', 90000);
App.wife.get('householdIncome'); // 90000

Note that bindings don't update immediately. Ember waits until all of your application code has finished running before synchronizing changes, so you can change a bound property as many times as you'd like without worrying about the overhead of syncing bindings when values are transient.

Hope it helps in extend of original answer selected.

The HTTP request is unauthorized with client authentication scheme 'Ntlm'. The authentication header received from the server was 'Negotiate,NTLM'

You can eliminate the client from the problem by using wftech, this is an old tool but I have found it useful in diagnosing authentication issues. wfetch allows you to specify NTLM, Negotiate and kerberos, this may well help you better understand your problem. As you are trying to call a service and wfetch knows nothing about WCF, I would suggest applying your endpoint binding (PROVIDERSSoapBinding) to the serviceMetadata then you can do an HTTP GET of the WSDL for the service with the same security settings.

Another option, which may be available to you is to force the server to use NTLM, you can do this by either editing the metabase (IIS 6) and removing the Negotiate setting, more details at http://support.microsoft.com/kb/215383.

If you are using IIS 7.x then the approach is slightly different, details of how to configure the authentication providers are here http://www.iis.net/configreference/system.webserver/security/authentication/windowsauthentication.

I notice that you have blocked out the server address with xxx.xx.xx.xxx, so I'm guessing that this is an IP address rather than a server name, this may cause issues with authentication, so if possible try targeting the machine name.

Sorry that I haven't given you the answer but rather pointers for getting closer to the issue, but I hope it helps.

I'll finish by saying that I have experienced this same issue and my only recourse was to use Kerberos rather than NTLM, don't forget you'll need to register an SPN for the service if you do go down this route.

appcompat-v7:21.0.0': No resource found that matches the given name: attr 'android:actionModeShareDrawable'

I got the same error when I changed the Compile SDK version from API:21 to API:16. The problem was, appcompat version. If you need to use an older version of android API, so you have to change this appcompat version also. In my case (for API:16), I had to use appcompat-v7:19.+.

So I replace dependencies in build.gradle as follows,

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:19.+'
}

And make sure you have older versions of appcompat versions on your SDK enter image description here

Split string with PowerShell and do something with each token

-split outputs an array, and you can save it to a variable like this:

$a = -split 'Once  upon    a     time'
$a[0]

Once

Another cute thing, you can have arrays on both sides of an assignment statement:

$a,$b,$c = -split 'Once  upon    a'
$c

a

How to horizontally center an unordered list of unknown width?

One more solution:

#footer { display:table; margin:0 auto; }
#footer li { display:table-cell; padding: 0px 10px; }

Then ul doesn't jump to the next line in case of zooming text.

Font Awesome & Unicode

There are three different font families that I know of that you can choose from and each has its own weight element that needs to be applied:

First

font-family: 'Font Awesome 5 Brands'; content: "\f373";

Second

font-family: 'Font Awesome 5 Free'; content: "\f061"; font-weight: 900;

Third

font-family: 'Font Awesome 5 Pro';

Reference here - https://fontawesome.com/how-to-use/on-the-web/advanced/css-pseudo-elements

Hope this helps.

Cluster analysis in R: determine the optimal number of clusters

Splendid answer from Ben. However I'm surprised that the Affinity Propagation (AP) method has been here suggested just to find the number of cluster for the k-means method, where in general AP do a better job clustering the data. Please see the scientific paper supporting this method in Science here:

Frey, Brendan J., and Delbert Dueck. "Clustering by passing messages between data points." science 315.5814 (2007): 972-976.

So if you are not biased toward k-means I suggest to use AP directly, which will cluster the data without requiring knowing the number of clusters:

library(apcluster)
apclus = apcluster(negDistMat(r=2), data)
show(apclus)

If negative euclidean distances are not appropriate, then you can use another similarity measures provided in the same package. For example, for similarities based on Spearman correlations, this is what you need:

sim = corSimMat(data, method="spearman")
apclus = apcluster(s=sim)

Please note that those functions for similarities in the AP package are just provided for simplicity. In fact, apcluster() function in R will accept any matrix of correlations. The same before with corSimMat() can be done with this:

sim = cor(data, method="spearman")

or

sim = cor(t(data), method="spearman")

depending on what you want to cluster on your matrix (rows or cols).

Reversing a linked list in Java, recursively

public void reverseLinkedList(Node node){
    if(node==null){
        return;
    }

    reverseLinkedList(node.next);
    Node temp = node.next;
    node.next=node.prev;
    node.prev=temp;
    return;
}

How can I rename a field for all documents in MongoDB?

If you are using MongoMapper, this works:

Access.collection.update( {}, { '$rename' => { 'location' => 'location_info' } }, :multi => true )

How to install mod_ssl for Apache httpd?

I found I needed to enable the SSL module in Apache (obviously prefix commands with sudo if you are not running as root):

a2enmod ssl

then restart Apache:

/etc/init.d/apache2 restart

More details of SSL in Apache for Ubuntu / Debian here.

How does origin/HEAD get set?

It is your setting as the owner of your local repo. Change it like this:

git remote set-head origin some_branch

And origin/HEAD will point to your branch instead of master. This would then apply to your repo only and not for others. By default, it will point to master, unless something else has been configured on the remote repo.

Manual entry for remote set-head provides some good information on this.

Edit: to emphasize: without you telling it to, the only way it would "move" would be a case like renaming the master branch, which I don't think is considered "organic". So, I would say organically it does not move.

ClientScript.RegisterClientScriptBlock?

The method System.Web.UI.Page.RegisterClientScriptBlock has been deprecated for some time (along with the other Page.Register* methods), ever since .NET 2.0 as shown by MSDN.

Instead use the .NET 2.0 Page.ClientScript.Register* methods. - (The ClientScript property expresses an instance of the ClientScriptManager class )

Guessing the problem

If you are saying your JavaScript alert box occurs before the page's content is visibly rendered, and therefore the page remains white (or still unrendered) when the alert box is dismissed by the user, then try using the Page.ClientScript.RegisterStartupScript(..) method instead because it runs the given client-side code when the page finishes loading - and its arguments are similar to what you're using already.

Also check for general JavaScript errors in the page - this is often seen by an error icon in the browser's status bar. Sometimes a JavaScript error will hold up or disturb unrelated elements on the page.

What is Python buffer type for?

I think buffers are e.g. useful when interfacing python to native libraries. (Guido van Rossum explains buffer in this mailinglist post).

For example, numpy seems to use buffer for efficient data storage:

import numpy
a = numpy.ndarray(1000000)

the a.data is a:

<read-write buffer for 0x1d7b410, size 8000000, offset 0 at 0x1e353b0>

Determine command line working directory when running node bin script

Alternatively, if you want to solely obtain the current directory of the current NodeJS script, you could try something simple like this. Note that this will not work in the Node CLI itself:

var fs = require('fs'),
    path = require('path');

var dirString = path.dirname(fs.realpathSync(__filename));

// output example: "/Users/jb/workspace/abtest"
console.log('directory to start walking...', dirString);

What is Mocking?

Mock is a method/object that simulates the behavior of a real method/object in controlled ways. Mock objects are used in unit testing.

Often a method under a test calls other external services or methods within it. These are called dependencies. Once mocked, the dependencies behave the way we defined them.

With the dependencies being controlled by mocks, we can easily test the behavior of the method that we coded. This is Unit testing.

What is the purpose of mock objects?

Mocks vs stubs

Unit tests vs Functional tests

No connection could be made because the target machine actively refused it 127.0.0.1

The issue disappeared for me when I started Fiddler. Was using it on my machine before having the issue. Probably something with Fiddler being proxy.

How do I move a file (or folder) from one folder to another in TortoiseSVN?

To move a file or set of files using Tortoise SVN, right-click-and-drag the target files to their destination and release the right mouse button. The popup menu will have a SVN move versioned files here option.

Note that the destination folder must have already been added to the repository for the SVN move versioned files here option to appear.

How to make <a href=""> link look like a button?

None of other answers shows the code where the link button changes its appearance on hover.

This is what I've done to fix that:

HTML:

<a href="http://www.google.com" class="link_button2">My button</a>

CSS:

.link_button2 {
  -webkit-border-radius: 4px;
  -moz-border-radius: 4px;
  border-radius: 4px;
  border: solid 1px #1A4575;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.4);
  -webkit-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.4), 0 1px 1px rgba(0, 0, 0, 0.2);
  -moz-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.4), 0 1px 1px rgba(0, 0, 0, 0.2);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.4), 0 1px 1px rgba(0, 0, 0, 0.2);
  background: #3A68A1;
  color: #fee1cc;
  text-decoration: none;
  padding: 8px 12px;
  text-decoration: none;
  font-size: larger;
}

a.link_button2:hover {
  text-decoration: underline;
  background: #4479BA;
  border: solid 1px #20538D;

  /* optional different shadow on hover
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.7);
  -webkit-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7), 0 1px 1px rgba(0, 0, 0, 0.4);
  -moz-box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7), 0 1px 1px rgba(0, 0, 0, 0.4);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7), 0 1px 1px rgba(0, 0, 0, 0.4);
  */

}

JSFiddle: https://jsfiddle.net/adamovic/ovu3k0cj/

How to call a JavaScript function from PHP?

try like this

<?php
 if(your condition){
     echo "<script> window.onload = function() {
     yourJavascriptFunction(param1, param2);
 }; </script>";
?>

How can I check if a Perl module is installed on my system from the command line?

Bravo for @user80168's solution (I'm still counting \'s !) but to avoid all the escaping involved with aliases and shells:

%~/ cat ~/bin/perlmod
perl -le'eval qq{require $ARGV[0]; } 
    ? print ( "Found $ARGV[0] Version: ", eval "$ARGV[0]->VERSION" ) 
    : print "Not installed" ' $1

works reasonably well.

Here might be the simplest and most "modern" approach, using Module::Runtime:

perl -MModule::Runtime=use_module -E '
     say "$ARGV[0] ", use_module($ARGV[0])->VERSION' DBI

This will give a useful error if the module is not installed.

Using -MModule::Runtime requires it to be installed (it is not a core module).

How to export non-exportable private key from store

You might need to uninstall antivirus (in my case I had to get rid of Avast).

This makes sure that crypto::cng command will work. Otherwise it was giving me errors:

mimikatz $ crypto::cng
ERROR kull_m_patch_genericProcessOrServiceFromBuild ; OpenProcess (0x00000005)

After removing Avast:

mimikatz $ crypto::cng
"KeyIso" service patched

Magic. (:

BTW

Windows Defender is another program blocking the program to work, so you will need also to disable it for the time of using program at least.

How to get the selected date of a MonthCalendar control in C#

"Just set the MaxSelectionCount to 1 so that users cannot select more than one day. Then in the SelectionRange.Start.ToString(). There is nothing available to show the selection of only one day." - Justin Etheredge

From here.

Convert JSON string to array of JSON objects in Javascript

Using jQuery:

var str = '{"id":1,"name":"Test1"},{"id":2,"name":"Test2"}';
var jsonObj = $.parseJSON('[' + str + ']');

jsonObj is your JSON object.

SQL select statements with multiple tables

Like that:

SELECT p.*, a.street, a.city FROM persons AS p
JOIN address AS a ON p.id = a.person_id
WHERE a.zip = '97299'

TypeError: $.browser is undefined

$.browser has been removed from JQuery 1.9. You can to use Modernizr project instead

http://jquery.com/upgrade-guide/1.9/#jquery-browser-removed

UPDATE TO SUPPORT IE 10 AND IE 11 (TRIDENT version)

To complete the @daniel.moura answer, here is a version which support IE 11 and +

var matched, browser;

jQuery.uaMatch = function( ua ) {
    ua = ua.toLowerCase();

    var match = /(chrome)[ \/]([\w.]+)/.exec( ua ) ||
        /(webkit)[ \/]([\w.]+)/.exec( ua ) ||
        /(opera)(?:.*version|)[ \/]([\w.]+)/.exec( ua ) ||
        /(msie)[\s?]([\w.]+)/.exec( ua ) ||       
        /(trident)(?:.*? rv:([\w.]+)|)/.exec( ua ) ||
        ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec( ua ) ||
        [];

    return {
        browser: match[ 1 ] || "",
        version: match[ 2 ] || "0"
    };
};

matched = jQuery.uaMatch( navigator.userAgent );
//IE 11+ fix (Trident) 
matched.browser = matched.browser == 'trident' ? 'msie' : matched.browser;
browser = {};

if ( matched.browser ) {
    browser[ matched.browser ] = true;
    browser.version = matched.version;
}

// Chrome is Webkit, but Webkit is also Safari.
if ( browser.chrome ) {
    browser.webkit = true;
} else if ( browser.webkit ) {
    browser.safari = true;
}

jQuery.browser = browser;
// log removed - adds an extra dependency
//log(jQuery.browser)

Can't install nuget package because of "Failed to initialize the PowerShell host"

I had the same problem after upgrading to Windows 10.

This worked for me

  1. Close Visual Studio
  2. Run Powershell as admin
  3. Run Set-ExecutionPolicy Unrestricted
  4. Run Visual studio as admin
  5. Clean the project and add the nuget package

If it still doesn't work try editing devenv.exe.config

Visual Studio 2013: C:\Users\<UserName>\AppData\Local\Microsoft\VisualStudio\12.0

Visual Studio 2015: C:\Users\<UserName>\AppData\Local\Microsoft\VisualStudio\14.0

Add the following

    <dependentAssembly>
        <assemblyIdentity name="System.Management.Automation" publicKeyToken="31bf3856ad364e35" />
        <publisherPolicy apply="no" />
    </dependentAssembly>
    <dependentAssembly>
      <assemblyIdentity name="Microsoft.PowerShell.Commands.Utility" publicKeyToken="31bf3856ad364e35" />
      <publisherPolicy apply="no" />
    </dependentAssembly>
    <dependentAssembly>
      <assemblyIdentity name="Microsoft.PowerShell.ConsoleHost" publicKeyToken="31bf3856ad364e35" />
      <publisherPolicy apply="no" />
    </dependentAssembly>
    <dependentAssembly>
      <assemblyIdentity name="Microsoft.PowerShell.Commands.Management" publicKeyToken="31bf3856ad364e35" />
      <publisherPolicy apply="no" />
    </dependentAssembly>
    <dependentAssembly>
      <assemblyIdentity name="Microsoft.PowerShell.Security" publicKeyToken="31bf3856ad364e35" />
      <publisherPolicy apply="no" />
    </dependentAssembly>
    <dependentAssembly>
      <assemblyIdentity name="Microsoft.PowerShell.Commands.Diagnostics" publicKeyToken="31bf3856ad364e35" />
      <publisherPolicy apply="no" />
    </dependentAssembly>

What is the SQL command to return the field names of a table?

Just for completeness, since MySQL and Postgres have already been mentioned: With SQLite, use "pragma table_info()"

sqlite> pragma table_info('table_name');
cid         name        type        notnull     dflt_value  pk        
----------  ----------  ----------  ----------  ----------  ----------
0           id          integer     99                      1         
1           name                    0                       0         

Do you (really) write exception safe code?

First of all (as Neil stated), SEH is Microsoft's Structured Exception Handling. It is similar to but not identical to exception processing in C++. In fact, you have to enable C++ Exception Handling if you want it in Visual Studio - the default behavior does not guarantee that local objects are destroyed in all cases! In either case, Exception Handling is not really harder it is just different.

Now for your actual questions.

Do you really write exception safe code?

Yes. I strive for exception safe code in all cases. I evangelize using RAII techniques for scoped access to resources (e.g., boost::shared_ptr for memory, boost::lock_guard for locking). In general, consistent usage of RAII and scope guarding techniques will make exception safe code much easier to write. The trick is to learn what exists and how to apply it.

Are you sure your last "production ready" code is exception safe?

No. It is as safe as it is. I can say that I haven't seen a process fault due to an exception in several years of 24/7 activity. I don't expect perfect code, just well-written code. In addition to providing exception safety, the techniques above guarantee correctness in a way that is near impossible to achieve with try/catch blocks. If you are catching everything in your top control scope (thread, process, etc.), then you can be sure that you will continue to run in the face of exceptions (most of the time). The same techniques will also help you continue to run correctly in the face of exceptions without try/catch blocks everywhere.

Can you even be sure that it is?

Yes. You can be sure by a thorough code audit but no one really does that do they? Regular code reviews and careful developers go a long way to getting there though.

Do you know and/or actually use alternatives that work?

I have tried a few variations over the years such as encoding states in the upper bits (ala HRESULTs) or that horrible setjmp() ... longjmp() hack. Both of these break down in practice though in completely different ways.


In the end, if you get into the habit of applying a few techniques and carefully thinking about where you can actually do something in response to an exception, you will end up with very readable code that is exception safe. You can sum this up by following these rules:

  • You only want to see try/catch when you can do something about a specific exception
  • You almost never want to see a raw new or delete in code
  • Eschew std::sprintf, snprintf, and arrays in general - use std::ostringstream for formatting and replace arrays with std::vector and std::string
  • When in doubt, look for functionality in Boost or STL before rolling your own

I can only recommend that you learn how to use exceptions properly and forget about result codes if you plan on writing in C++. If you want to avoid exceptions, you might want to consider writing in another language that either does not have them or makes them safe. If you want to really learn how to fully utilize C++, read a few books from Herb Sutter, Nicolai Josuttis, and Scott Meyers.

Converting XML to JSON using Python?

There is a method to transport XML-based markup as JSON which allows it to be losslessly converted back to its original form. See http://jsonml.org/.

It's a kind of XSLT of JSON. I hope you find it helpful

What is it exactly a BLOB in a DBMS context

any large single block of data stored in a database, such as a picture or sound file, which does not include record fields, and cannot be directly searched by the database's search engine.

C++ getters/setters coding style

From the Design Patterns theory; "encapsulate what varies". By defining a 'getter' there is good adherence to the above principle. So, if the implementation-representation of the member changes in future, the member can be 'massaged' before returning from the 'getter'; implying no code refactoring at the client side where the 'getter' call is made.

Regards,

setting the id attribute of an input element dynamically in IE: alternative for setAttribute method

I wasn't aware of a problem with setAttribute in IE ? However you could directly set the expando property on the node itself:

hiddenInput.id = "uniqueIdentifier";

Drawing an SVG file on a HTML5 canvas

Sorry, i don't have enough reputation to comment on the @Matyas answer, but if the svg's image is also in base64, it will be drawed to the output.

Demo:

_x000D_
_x000D_
var svg = document.querySelector('svg');_x000D_
var img = document.querySelector('img');_x000D_
var canvas = document.querySelector('canvas');_x000D_
_x000D_
// get svg data_x000D_
var xml = new XMLSerializer().serializeToString(svg);_x000D_
_x000D_
// make it base64_x000D_
var svg64 = btoa(xml);_x000D_
var b64Start = 'data:image/svg+xml;base64,';_x000D_
_x000D_
// prepend a "header"_x000D_
var image64 = b64Start + svg64;_x000D_
_x000D_
// set it as the source of the img element_x000D_
img.onload = function() {_x000D_
    // draw the image onto the canvas_x000D_
    canvas.getContext('2d').drawImage(img, 0, 0);_x000D_
}_x000D_
img.src = image64;
_x000D_
svg, img, canvas {_x000D_
  display: block;_x000D_
}
_x000D_
SVG_x000D_
_x000D_
<svg height="40">_x000D_
  <rect width="40" height="40" style="fill:rgb(255,0,255);" />_x000D_
  <image xlink:href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUCAYAAACNiR0NAAAEX0lEQVQ4jUWUyW6cVRCFv7r3/kO3u912nNgZgESAAgGBCJgFgxhW7FkgxAbxMLwBEmIRITbsQAgxCEUiSIBAYIY4g1EmYjuDp457+Lv7n+4tFjbwAHVOnVPnlLz75ht67OhhZg/M0p6d5tD9C8SNBBs5XBJhI4uNLC4SREA0UI9yJr2c4e6QO+v3WF27w+rmNrv9Pm7hxDyHFg5yYGEOYxytuRY2SYiSCIwgRgBQIxgjEAKuZWg6R9S0SCS4qKLZElY3HC5tp7QPtmlMN7HOETUTXBJjrEGsAfgPFECsQbBIbDGJZUYgGE8ugQyPm+o0STtTuGZMnKZEjRjjLIgAirEOEQEBDQFBEFFEBWLFtVJmpENRl6hUuFanTRAlbTeZarcx0R6YNZagAdD/t5N9+QgCYAw2jrAhpjM3zaSY4OJGTDrVwEYOYw2qioigoviq5MqF31m9fg1V5fCx+zn11CLNVnufRhBrsVFE1Ihpthu4KDYYwz5YQIxFBG7duMZnH31IqHL6wwnGCLFd4pez3/DaG2/x4GNPgBhEZG/GGlxkMVFkiNMYay3Inqxed4eP33uf7Y0uu90xWkGolFAru7sZn5w5w921m3u+su8vinEO02hEWLN/ANnL2rkvv2an2yd4SCKLM0JVBsCgAYZZzrnPP0eDRzXgfaCuPHXwuEYjRgmIBlQVVLl8/hKI4fRzz3L6uWe5+PMvnHz6aa4uX+D4yYe5vXaLH86eoyoLjLF476l9oKo9pi5HWONRX8E+YznOef7Vl1h86QWurlwjbc+QpikPPfoIcZLS39pmMikp8pzae6q6oqgriqrGqS+xeLScoMYSVJlfOMTl5RXW1+5w5fJVnFGWf1/mxEMnWPppiclkTLM5RdJoUBYFZVlQ5DnZMMMV167gixKLoXXsKGqnOHnqOJ/+/CfZ+XUiZ0jTmFv5mAvf/YjEliQ2vPD8Ir6qqEcZkzt38cMRo5WruFvfL9FqpyRxQhj0qLOax5I2S08+Tu/lFiGUGOPormxwuyfMnjrGrJa88uIixeYWl776lmrzNjmw8vcG8sU7ixpHMXFsCUVg9tABjEvRgzP82j7AhbyiX5Qcv2+Bvy7dYGZ1k7efeQB/Y4PBqGBtdYvb3SFzLcfqToZc/OB1zYeBSpUwLBlvjZidmWaSB1yaYOfn6LqI/r0hyU6P+cRSlhXjbEI2zvnt7y79oqQ3qeg4g6vKjCIXehtDmi6m0UnxVnCRkPUHVNt9qkLJxgXOCYNOg34v48raPaamU2o89/KKsQ9sTSpc0JK7NwdcX8s43Ek5cnSOLC/Z2R6Rj0ra0w2W1/t0xyWn51uk2Ri1QtSO6OU5d7OSi72cQeWxKG7p/Dp//JXTy6C1Pcbc6DMpPRtjTxChEznWhwVZUCKrjCrPoPDczHLmnLBdBgZlRRWUEBR3ZKrme5TlrTGlV440Y1IrXM9qQGi6mkG5V6uza7tUIeCDElTZ1L26elX+fcH/ACJBPYTJ4X8tAAAAAElFTkSuQmCC" height="20px" width="20px" x="10" y="10"></image>_x000D_
</svg>_x000D_
<hr/><br/>_x000D_
_x000D_
IMAGE_x000D_
<img/>_x000D_
<hr/><br/>_x000D_
   _x000D_
CANVAS_x000D_
<canvas></canvas>_x000D_
<hr/><br/>
_x000D_
_x000D_
_x000D_

How to make a redirection on page load in JSF 1.x

Set the GET query parameters as managed properties in faces-config.xml so that you don't need to gather them manually:

<managed-bean>
    <managed-bean-name>forward</managed-bean-name>
    <managed-bean-class>com.example.ForwardBean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    <managed-property>
        <property-name>action</property-name>
        <value>#{param.action}</value>
    </managed-property>
    <managed-property>
        <property-name>actionParam</property-name>
        <value>#{param.actionParam}</value>
    </managed-property>
</managed-bean>

This way the request forward.jsf?action=outcome1&actionParam=123 will let JSF set the action and actionParam parameters as action and actionParam properties of the ForwardBean.

Create a small view forward.xhtml (so small that it fits in default response buffer (often 2KB) so that it can be resetted by the navigationhandler, otherwise you've to increase the response buffer in the servletcontainer's configuration), which invokes a bean method on beforePhase of the f:view:

<!DOCTYPE html>
<html xmlns:f="http://java.sun.com/jsf/core">
    <f:view beforePhase="#{forward.navigate}" />
</html>

The ForwardBean can look like this:

public class ForwardBean {
    private String action;
    private String actionParam;

    public void navigate(PhaseEvent event) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        String outcome = action; // Do your thing?
        facesContext.getApplication().getNavigationHandler().handleNavigation(facesContext, null, outcome);
    }

    // Add/generate the usual boilerplate.
}

The navigation-rule speaks for itself (note the <redirect /> entries which would do ExternalContext#redirect() instead of ExternalContext#dispatch() under the covers):

<navigation-rule>
    <navigation-case>
        <from-outcome>outcome1</from-outcome>
        <to-view-id>/outcome1.xhtml</to-view-id>
        <redirect />
    </navigation-case>
    <navigation-case>
        <from-outcome>outcome2</from-outcome>
        <to-view-id>/outcome2.xhtml</to-view-id>
        <redirect />
    </navigation-case>
</navigation-rule>

An alternative is to use forward.xhtml as

<!DOCTYPE html>
<html>#{forward}</html>

and update the navigate() method to be invoked on @PostConstruct (which will be invoked after bean's construction and all managed property setting):

@PostConstruct
public void navigate() {
    // ...
}    

It has the same effect, however the view side is not really self-documenting. All it basically does is printing ForwardBean#toString() (and hereby implicitly constructing the bean if not present yet).


Note for the JSF2 users, there is a cleaner way of passing parameters with <f:viewParam> and more robust way of handling the redirect/navigation by <f:event type="preRenderView">. See also among others:

How to determine previous page URL in Angular?

All the Above ANSWER will be loads URL multiple times. If user visited any other component also, these code will loads.

So better to use, Service creating concept. https://community.wia.io/d/22-access-the-previous-route-in-your-angular-5-app

This will works well in all versions of Angular. (please Make sure to add it to the providers array in your app.module file! )

Visualizing decision tree in scikit-learn

sklearn.tree.export_graphviz doesn't return anything, and so by default returns None.

By doing dotfile = tree.export_graphviz(...) you overwrite your open file object, which had been previously assigned to dotfile, so you get an error when you try to close the file (as it's now None).

To fix it change your code to

...
dotfile = open("D:/dtree2.dot", 'w')
tree.export_graphviz(dtree, out_file = dotfile, feature_names = X.columns)
dotfile.close()
...

SimpleDateFormat parsing date with 'Z' literal

The restlet project includes an InternetDateFormat class that can parse RFC 3339 dates.

Restlet InternetDateFormat

Though, you might just want to replace the trailing 'Z' with "UTC" before you parse it.

Maximum number of threads per process in Linux?

You can see the current value by the following command- cat /proc/sys/kernel/threads-max

You can also set the value like

echo 100500 > /proc/sys/kernel/threads-max

The value you set would be checked against the available RAM pages. If the thread structures occupies more than 1/8th) of the available RAM pages, thread-max would be reduced accordingly.

Git fails when pushing commit to github

If this command not help

git config http.postBuffer 524288000

Try to change ssh method to https

git remote -v
git remote rm origin 
git remote add origin https://github.com/username/project.git

Return zero if no record is found

You could:

SELECT COALESCE(SUM(columnA), 0) FROM my_table WHERE columnB = 1
INTO res;

This happens to work, because your query has an aggregate function and consequently always returns a row, even if nothing is found in the underlying table.

Plain queries without aggregate would return no row in such a case. COALESCE would never be called and couldn't save you. While dealing with a single column we can wrap the whole query instead:

SELECT COALESCE( (SELECT columnA FROM my_table WHERE ID = 1), 0)
INTO res;

Works for your original query as well:

SELECT COALESCE( (SELECT SUM(columnA) FROM my_table WHERE columnB = 1), 0)
INTO res;

More about COALESCE() in the manual.
More about aggregate functions in the manual.
More alternatives in this later post:

Add Auto-Increment ID to existing table?

First you have to remove the primary key of the table

ALTER TABLE nametable DROP PRIMARY KEY

and now yo can add the autoincrement ...

ALTER TABLE nametable ADD id INT NOT NULL AUTO_INCREMENT PRIMARY KEY

The SELECT permission was denied on the object 'Users', database 'XXX', schema 'dbo'

I think the problem is with the user having deny privileges. This error comes when the user which you have created does not have the sufficient privileges to access your tables in the database. Do grant the privilege to the user in order to get what you want.

GRANT the user specific permissions such as SELECT, INSERT, UPDATE and DELETE on tables in that database.

How to remove multiple indexes from a list at the same time?

remove_indices = [1,2,3]
somelist = [i for j, i in enumerate(somelist) if j not in remove_indices]

Example:

In [9]: remove_indices = [1,2,3]

In [10]: somelist = range(10)

In [11]: somelist = [i for j, i in enumerate(somelist) if j not in remove_indices]

In [12]: somelist
Out[12]: [0, 4, 5, 6, 7, 8, 9]

How to open the command prompt and insert commands using Java?

You just need to append your command after start in the string that you are passing.

String command = "cmd.exe /c start "+"*your command*";

Process child = Runtime.getRuntime().exec(command);

Entity Framework vs LINQ to SQL

LINQ to SQL

  1. Homogeneous datasource: SQL Server
  2. Recommended for small projects only where data structure is well designed
  3. Mapping can be changed without recompilling with SqlMetal.exe
  4. .dbml (Database Markup Language)
  5. One-to-one mapping between tables and classes
  6. Supports TPH inheritance
  7. Doesn't support complex types
  8. Storage-first approach
  9. Database-centric view of a database
  10. Created by C# team
  11. Supported but not further improvements intended

Entity Framework

  1. Heterogeneus datasource: Support many data providers
  2. Recommended for all new projects except:
    • small ones (LINQ to SQL)
    • when data source is a flat file (ADO.NET)
  3. Mapping can be changed without recompilling when setting model and mapping files Metadata Artifact Process to Copy To Output Directory
  4. .edmx (Entity Data Model) which contains:
    • SSDL (Storage Schema Definition Language)
    • CSDL (Conceptual Schema Definition Language)
    • MSL (Mapping Specification Language)
  5. One-to-one, one-to-many, many-to-one mappings between tables and classes
  6. Supports inheritence:
    • TPH (Table Per Hierarchy)
    • TPT (Table Per Type)
    • TPC (Table Per Concrete Class)
  7. Supports complex types
  8. Code-first, Model-first, Storage-first approaches
  9. Application-centric view of a database
  10. Created by SQL Server team
  11. Future of Microsoft Data APIs

See also:

'too many values to unpack', iterating over a dict. key=>string, value=>list

Can't be iterating directly in dictionary. So you can through converting into tuple.

first_names = ['foo', 'bar']
last_names = ['gravy', 'snowman']

fields = {
    'first_names': first_names,
    'last_name': last_names,
         } 
tup_field=tuple(fields.items())
for names in fields.items():
     field,possible_values = names
     tup_possible_values=tuple(possible_values)
     for pvalue in tup_possible_values:
           print (field + "is" + pvalue)

Write to .txt file?

FILE *f = fopen("file.txt", "w");
if (f == NULL)
{
    printf("Error opening file!\n");
    exit(1);
}

/* print some text */
const char *text = "Write this to the file";
fprintf(f, "Some text: %s\n", text);

/* print integers and floats */
int i = 1;
float py = 3.1415927;
fprintf(f, "Integer: %d, float: %f\n", i, py);

/* printing single chatacters */
char c = 'A';
fprintf(f, "A character: %c\n", c);

fclose(f);

How can you dynamically create variables via a while loop?

NOTE: This should be considered a discussion rather than an actual answer.

An approximate approach is to operate __main__ in the module you want to create variables. For example there's a b.py:

#!/usr/bin/env python
# coding: utf-8


def set_vars():
    import __main__
    print '__main__', __main__
    __main__.B = 1

try:
    print B
except NameError as e:
    print e

set_vars()

print 'B: %s' % B

Running it would output

$ python b.py
name 'B' is not defined
__main__ <module '__main__' from 'b.py'>
B: 1

But this approach only works in a single module script, because the __main__ it import will always represent the module of the entry script being executed by python, this means that if b.py is involved by other code, the B variable will be created in the scope of the entry script instead of in b.py itself. Assume there is a script a.py:

#!/usr/bin/env python
# coding: utf-8

try:
    import b
except NameError as e:
    print e

print 'in a.py: B', B

Running it would output

$ python a.py
name 'B' is not defined
__main__ <module '__main__' from 'a.py'>
name 'B' is not defined
in a.py: B 1

Note that the __main__ is changed to 'a.py'.

Python: Maximum recursion depth exceeded

You can increment the stack depth allowed - with this, deeper recursive calls will be possible, like this:

import sys
sys.setrecursionlimit(10000) # 10000 is an example, try with different values

... But I'd advise you to first try to optimize your code, for instance, using iteration instead of recursion.

How to create a signed APK file using Cordova command line interface?

##Generated signed apk from commandline
#variables
APP_NAME=THE_APP_NAME
APK_LOCATION=./
APP_HOME=/path/to/THE_APP
APP_KEY=/path/to/Android_key
APP_KEY_ALIAS=the_alias
APP_KEY_PASSWORD=123456789
zipalign=$ANDROID_HOME/build-tools/28.0.3/zipalign

#the logic
cd $APP_HOME
cordova build --release android
cd platforms/android/app/build/outputs/apk/release
jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore $APP_KEY ./app-release-unsigned.apk $APP_KEY_ALIAS <<< $APP_KEY_PASSWORD
rm -rf "$APK_LOCATION/$APP_NAME.apk"
$zipalign -v 4 ./app-release-unsigned.apk "$APK_LOCATION/$APP_NAME.apk"
open $APK_LOCATION
#the end

How can I get a value from a map?

Unfortunately std::map::operator[] is a non-const member function, and you have a const reference.

You either need to change the signature of function or do:

MAP::const_iterator pos = map.find("string");
if (pos == map.end()) {
    //handle the error
} else {
    std::string value = pos->second;
    ...
}

operator[] handles the error by adding a default-constructed value to the map and returning a reference to it. This is no use when all you have is a const reference, so you will need to do something different.

You could ignore the possibility and write string value = map.find("string")->second;, if your program logic somehow guarantees that "string" is already a key. The obvious problem is that if you're wrong then you get undefined behavior.

How to set up devices for VS Code for a Flutter emulator

set "ANDROID_SDK_ROOT" in environment variable, solve my problem.

How to import multiple .csv files at once?

It was requested that I add this functionality to the stackoverflow R package. Given that it is a tinyverse package (and can't depend on third party packages), here is what I came up with:

#' Bulk import data files 
#' 
#' Read in each file at a path and then unnest them. Defaults to csv format.
#' 
#' @param path        a character vector of full path names
#' @param pattern     an optional \link[=regex]{regular expression}. Only file names which match the regular expression will be returned.
#' @param reader      a function that can read data from a file name.
#' @param ...         optional arguments to pass to the reader function (eg \code{stringsAsFactors}).
#' @param reducer     a function to unnest the individual data files. Use I to retain the nested structure. 
#' @param recursive     logical. Should the listing recurse into directories?
#'  
#' @author Neal Fultz
#' @references \url{https://stackoverflow.com/questions/11433432/how-to-import-multiple-csv-files-at-once}
#' 
#' @importFrom utils read.csv
#' @export
read.directory <- function(path='.', pattern=NULL, reader=read.csv, ..., 
                           reducer=function(dfs) do.call(rbind.data.frame, dfs), recursive=FALSE) {
  files <- list.files(path, pattern, full.names = TRUE, recursive = recursive)

  reducer(lapply(files, reader, ...))
}

By parameterizing the reader and reducer function, people can use data.table or dplyr if they so choose, or just use the base R functions that are fine for smaller data sets.

Get width height of remote image from url

Just pass a callback as argument like this:

_x000D_
_x000D_
function getMeta(url, callback) {_x000D_
    var img = new Image();_x000D_
    img.src = url;_x000D_
    img.onload = function() { callback(this.width, this.height); }_x000D_
}_x000D_
getMeta(_x000D_
  "http://snook.ca/files/mootools_83_snookca.png",_x000D_
  function(width, height) { alert(width + 'px ' + height + 'px') }_x000D_
);
_x000D_
_x000D_
_x000D_

postgresql duplicate key violates unique constraint

Referrence - https://www.calazan.com/how-to-reset-the-primary-key-sequence-in-postgresql-with-django/

I had the same problem try this: python manage.py sqlsequencereset table_name

Eg:

python manage.py sqlsequencereset auth

you need to run this in production settings(if you have) and you need Postgres installed to run this on the server

UIView Infinite 360 degree rotation animation?

Create the animation

- (CABasicAnimation *)spinAnimationWithDuration:(CGFloat)duration clockwise:(BOOL)clockwise repeat:(BOOL)repeats
{
    CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
    anim.toValue = clockwise ? @(M_PI * 2.0) : @(M_PI * -2.0);
    anim.duration = duration;
    anim.cumulative = YES;
    anim.repeatCount = repeats ? CGFLOAT_MAX : 0;
    return anim;
}

Add it to a view like this

CABasicAnimation *animation = [self spinAnimationWithDuration:1.0 clockwise:YES repeat:YES];
[self.spinningView.layer addAnimation:animation forKey:@"rotationAnimation"];

How is this answer different? You will have way cleaner code if most of your functions returns objects instead of just manipulating some objects here and there.

How do I strip all spaces out of a string in PHP?

If you know the white space is only due to spaces, you can use:

$string = str_replace(' ','',$string); 

But if it could be due to space, tab...you can use:

$string = preg_replace('/\s+/','',$string);

Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user 'root'@'localhost'(using password:YES)

I had same problem, but it worked for me.

  1. check if you have mysql installed

    enter image description here

If you don't have mysql installed, download from this link: https://dev.mysql.com/downloads/mysql/

  1. follow this instructions to install https://dev.mysql.com/doc/mysql-osx-excerpt/5.7/en/osx-installation-pkg.html

  2. You can test the connection without any problem.

(Sorry for my english, I agree fix me please)

I Hope I've helped. Greetings.

Where do I find the definition of size_t?

In minimalistic programs where a size_t definition was not loaded "by chance" in some include but I still need it in some context (for example to access std::vector<double>), then I use that context to extract the correct type. For example typedef std::vector<double>::size_type size_t.

(Surround with namespace {...} if necessary to make the scope limited.)

How to set the UITableView Section title programmatically (iPhone/iPad)?

Note that -(NSString *)tableView: titleForHeaderInSection: is not called by UITableView if - (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section is implemented in delegate of UITableView;

Creating a JSON Array in node js

This one helped me,

res.format({
        json:function(){
                            var responseData    = {};
                            responseData['status'] = 200;
                            responseData['outputPath']  = outputDirectoryPath;
                            responseData['sourcePath']  = url;
                            responseData['message'] = 'Scraping of requested resource initiated.';
                            responseData['logfile'] = logFileName;
                            res.json(JSON.stringify(responseData));
                        }
    });

select count(*) from table of mysql in php

Please start using PDO.

mysql_* is deprecated as of PHP 5.5.0 and will be removed entirely in 7. Let's make it easier to upgrade and start using it now.

$dbh = new \PDO($dsn, $user, $password);
$sth = $dbh->prepare('SELECT count(*) as total from Students');
$sth->execute();
print_r($sth->fetchColumn());

regular expression: match any word until first space

Derived from the answer of @SilentGhost I would use:

^([\S]+)

Check out this interactive regexr.com page to see the result and explanation for the suggested solution.

How do I seed a random class to avoid getting duplicate random values

A good seed initialisation can be done like this

Random rnd = new Random((int)DateTime.Now.Ticks);

The ticks will be unique and the cast into a int with probably a loose of value will be OK.

Android failed to load JS bundle

Apparently adb reverse was introduced in Android 5.0
Getting "error: closed" twice on "adb reverse"

I guess we have to go ahead with kzzzf's answer

START_STICKY and START_NOT_STICKY

KISS answer

Difference:

START_STICKY

the system will try to re-create your service after it is killed

START_NOT_STICKY

the system will not try to re-create your service after it is killed


Standard example:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return START_STICKY;
}

Finding out current index in EACH loop (Ruby)

x.each_with_index { |v, i| puts "current index...#{i}" }

Xcode: Could not locate device support files

In case of getting "Could not locate device support files" after your device iOS version has been updated and your Xcode is still old version, just copy old SDK under new name and restart Xcode. Open your terminal and do following:

$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/
$ cp -rpv  10.3.1\ \(14E8301\)/ 11.2.1

Restart Xcode and it will most probably work.

Getting only hour/minute of datetime

Try this:

String hourMinute = DateTime.Now.ToString("HH:mm");

Now you will get the time in hour:minute format.

How to join components of a path when you are constructing a URL in Python

You can use urllib.parse.urljoin:

>>> from urllib.parse import urljoin
>>> urljoin('/media/path/', 'js/foo.js')
'/media/path/js/foo.js'

But beware:

>>> urljoin('/media/path', 'js/foo.js')
'/media/js/foo.js'
>>> urljoin('/media/path', '/js/foo.js')
'/js/foo.js'

The reason you get different results from /js/foo.js and js/foo.js is because the former begins with a slash which signifies that it already begins at the website root.

On Python 2, you have to do

from urlparse import urljoin

How to save username and password with Mercurial?

A simple hack is to add username and password to the push url in your project's .hg/hgrc file:

[paths]
default = http://username:[email protected]/myproject

(Note that in this way you store the password in plain text)

If you're working on several projects under the same domain, you might want to add a rewrite rule in your ~/.hgrc file, to avoid repeating this for all projects:

[rewrite]
http.//mydomain.com = http://username:[email protected]

Again, since the password is stored in plain text, I usually store just my username.

If you're working under Gnome, I explain how to integrate Mercurial and the Gnome Keyring here:

http://aloiroberto.wordpress.com/2009/09/16/mercurial-gnome-keyring-integration/

Including non-Python files with setup.py

To accomplish what you're describing will take two steps...

  • The file needs to be added to the source tarball
  • setup.py needs to be modified to install the data file to the source path

Step 1: To add the file to the source tarball, include it in the MANIFEST

Create a MANIFEST template in the folder that contains setup.py

The MANIFEST is basically a text file with a list of all the files that will be included in the source tarball.

Here's what the MANIFEST for my project look like:

  • CHANGELOG.txt
  • INSTALL.txt
  • LICENSE.txt
  • pypreprocessor.py
  • README.txt
  • setup.py
  • test.py
  • TODO.txt

Note: While sdist does add some files automatically, I prefer to explicitly specify them to be sure instead of predicting what it does and doesn't.

Step 2: To install the data file to the source folder, modify setup.py

Since you're looking to add a data file (LICENSE.txt) to the source install folder you need to modify the data install path to match the source install path. This is necessary because, by default, data files are installed to a different location than source files.

To modify the data install dir to match the source install dir...

Pull the install dir info from distutils with:

from distutils.command.install import INSTALL_SCHEMES

Modify the data install dir to match the source install dir:

for scheme in INSTALL_SCHEMES.values():
    scheme['data'] = scheme['purelib']

And, add the data file and location to setup():

data_files=[('', ['LICENSE.txt'])]

Note: The steps above should accomplish exactly what you described in a standard manner without requiring any extension libraries.

The ScriptManager must appear before any controls that need it

The script manager must be put onto the page before it is used. This would be directly on the page itself, or alternatively, if you are using them, on the Master Page.

The markup would be;

 <asp:ScriptManager ID="ScriptManager1" runat="server" LoadScriptsBeforeUI="true"
            EnablePartialRendering="true" />

How to open SharePoint files in Chrome/Firefox

Installing the Chrome extension IE Tab did the job for me.

It has the ability to auto-detect URLs so whenever I browse to our SharePoint it emulates Internet Explorer. Finally I can open Office documents directly from Chrome.

You can install IETab for FireFox too.

Handle Guzzle exception and get HTTP body

As of 2019 here is what I elaborated from the answers above and Guzzle docs to handle the exception, get the response body, status code, message and the other sometimes valuable response items.

try {
    /**
     * We use Guzzle to make an HTTP request somewhere in the
     * following theMethodMayThrowException().
     */
    $result = theMethodMayThrowException();
} catch (\GuzzleHttp\Exception\RequestException $e) {
    /**
     * Here we actually catch the instance of GuzzleHttp\Psr7\Response
     * (find it in ./vendor/guzzlehttp/psr7/src/Response.php) with all
     * its own and its 'Message' trait's methods. See more explanations below.
     *
     * So you can have: HTTP status code, message, headers and body.
     * Just check the exception object has the response before.
     */
    if ($e->hasResponse()) {
        $response = $e->getResponse();
        var_dump($response->getStatusCode()); // HTTP status code;
        var_dump($response->getReasonPhrase()); // Response message;
        var_dump((string) $response->getBody()); // Body, normally it is JSON;
        var_dump(json_decode((string) $response->getBody())); // Body as the decoded JSON;
        var_dump($response->getHeaders()); // Headers array;
        var_dump($response->hasHeader('Content-Type')); // Is the header presented?
        var_dump($response->getHeader('Content-Type')[0]); // Concrete header value;
    }
}
// process $result etc. ...

Voila. You get the response's information in conveniently separated items.

Side Notes:

With catch clause we catch the inheritance chain PHP root exception class \Exception as Guzzle custom exceptions extend it.

This approach may be useful for use cases where Guzzle is used under the hood like in Laravel or AWS API PHP SDK so you cannot catch the genuine Guzzle exception.

In this case, the exception class may not be the one mentioned in the Guzzle docs (e.g. GuzzleHttp\Exception\RequestException as the root exception for Guzzle).

So you have to catch \Exception instead but bear in mind it is still the Guzzle exception class instance.

Though use with care. Those wrappers may make Guzzle $e->getResponse() object's genuine methods not available. In this case, you will have to look at the wrapper's actual exception source code and find out how to get status, message, etc. instead of using Guzzle $response's methods.

If you call Guzzle directly yourself you can catch GuzzleHttp\Exception\RequestException or any other one mentioned in their exceptions docs with respect to your use case conditions.

Cleaning `Inf` values from an R dataframe

Option 1

Use the fact that a data.frame is a list of columns, then use do.call to recreate a data.frame.

do.call(data.frame,lapply(DT, function(x) replace(x, is.infinite(x),NA)))

Option 2 -- data.table

You could use data.table and set. This avoids some internal copying.

DT <- data.table(dat)
invisible(lapply(names(DT),function(.name) set(DT, which(is.infinite(DT[[.name]])), j = .name,value =NA)))

Or using column numbers (possibly faster if there are a lot of columns):

for (j in 1:ncol(DT)) set(DT, which(is.infinite(DT[[j]])), j, NA)

Timings

# some `big(ish)` data
dat <- data.frame(a = rep(c(1,Inf), 1e6), b = rep(c(Inf,2), 1e6), 
                  c = rep(c('a','b'),1e6),d = rep(c(1,Inf), 1e6),  
                  e = rep(c(Inf,2), 1e6))
# create data.table
library(data.table)
DT <- data.table(dat)

# replace (@mnel)
system.time(na_dat <- do.call(data.frame,lapply(dat, function(x) replace(x, is.infinite(x),NA))))
## user  system elapsed 
#  0.52    0.01    0.53 

# is.na (@dwin)
system.time(is.na(dat) <- sapply(dat, is.infinite))
# user  system elapsed 
# 32.96    0.07   33.12 

# modified is.na
system.time(is.na(dat) <- do.call(cbind,lapply(dat, is.infinite)))
#  user  system elapsed 
# 1.22    0.38    1.60 


# data.table (@mnel)
system.time(invisible(lapply(names(DT),function(.name) set(DT, which(is.infinite(DT[[.name]])), j = .name,value =NA))))
# user  system elapsed 
# 0.29    0.02    0.31 

data.table is the quickest. Using sapply slows things down noticeably.

What's the difference between Visual Studio Community and other, paid versions?

There are 2 major differences.

  1. Technical
  2. Licensing

Technical, there are 3 major differences:

First and foremost, Community doesn't have TFS support.
You'll just have to use git (arguable whether this constitutes a disadvantage or whether this actually is a good thing).
Note: This is what MS wrote. Actually, you can check-in&out with TFS as normal, if you have a TFS server in the network. You just cannot use Visual Studio as TFS SERVER.

Second, VS Community is severely limited in its testing capability.
Only unit tests. No Performance tests, no load tests, no performance profiling.

Third, VS Community's ability to create Virtual Environments has been severely cut.

On the other hand, syntax highlighting, IntelliSense, Step-Through debugging, GoTo-Definition, Git-Integration and Build/Publish are really all the features I need, and I guess that applies to a lot of developers.

For all other things, there are tools that do the same job faster, better and cheaper.

If you, like me, anyway use git, do unit testing with NUnit, and use Java-Tools to do Load-Testing on Linux plus TeamCity for CI, VS Community is more than sufficient, technically speaking.

Licensing:

A) If you're an individual developer (no enterprise, no organization), no difference (AFAIK), you can use CommunityEdition like you'd use the paid edition (as long as you don't do subcontracting)
B) You can use CommunityEdition freely for OpenSource (OSI) projects
C) If you're an educational insitution, you can use CommunityEdition freely (for education/classroom use)
D) If you're an enterprise with 250 PCs or users or more than one million US dollars in revenue (including subsidiaries), you are NOT ALLOWED to use CommunityEdition.
E) If you're not an enterprise as defined above, and don't do OSI or education, but are an "enterprise"/organization, with 5 or less concurrent (VS) developers, you can use VS Community freely (but only if you're the owner of the software and sell it, not if you're a subcontractor creating software for a larger enterprise, software which in the end the enterprise will own), otherwise you need a paid edition.

The above does not consitute legal advise.
See also:
https://softwareengineering.stackexchange.com/questions/262916/understanding-visual-studio-community-edition-license

CSS: How to remove pseudo elements (after, before,...)?

This depends on what's actually being added by the pseudoselectors. In your situation, setting content to "" will get rid of it, but if you're setting borders or backgrounds or whatever, you need to zero those out specifically. As far as I know, there's no one cure-all for removing everything about a before/after element regardless of what it is.

What does the construct x = x || y mean?

Quote: "What does the construct x = x || y mean?"

Assigning a default value.

This means providing a default value of y to x, in case x is still waiting for its value but hasn't received it yet or was deliberately omitted in order to fall back to a default.

Using Python Requests: Sessions, Cookies, and POST

I don't know how stubhub's api works, but generally it should look like this:

s = requests.Session()
data = {"login":"my_login", "password":"my_password"}
url = "http://example.net/login"
r = s.post(url, data=data)

Now your session contains cookies provided by login form. To access cookies of this session simply use

s.cookies

Any further actions like another requests will have this cookie

Factorial in numpy and scipy

enter image description here

after running different aforementioned functions for factorial, by different people, turns out that math.factorial is the fastest to calculate the factorial.

find running times for different functions in the attached image

C++ - unable to start correctly (0xc0150002)

I met such problem. Visual Studio 2008 clearly said: problem was caused by libtiff.dll. It cannot be loaded for some reasom, caused by its manifest (as a matter of fact, this dll has no manifest at all). I fixed it, when I had removed libtiff.dll from my project (but simultaneously I lost ability to open compressed TIFFs!). I recompiled aforementioned dll, but problem still remains. Interesting, that at my own machine I have no such error. Three others comps refused to load my prog. Attention!!! Here http://www.error-repair-tools.com/ppc/error.php?t=0xc0150002 one wise boy wrote, that this error was caused by problem with registry and offers repair tool. I have a solid guess, that this "repair tool" will install some malicious soft at your comp.

Steps to upload an iPhone application to the AppStore

Apple provides detailed, illustrated instructions covering every step of the process. Log in to the iPhone developer site and click the "program portal" link. In the program portal you'll find a link to the program portal user's guide, which is a really good reference and guide on this topic.

add/remove active class for ul list with jquery?

I used this:

$('.nav-list li.active').removeClass('active');
$(this).parent().addClass('active');

Since the active class is in the <li> element and what is clicked is the <a> element, the first line removes .active from all <li> and the second one (again, $(this) represents <a> which is the clicked element) adds .active to the direct parent, which is <li>.

Counting no of rows returned by a select query

select COUNT(*)
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5

Android Closing Activity Programmatically

You Can use just finish(); everywhere after Activity Start for clear that Activity from Stack.

How to convert a pymongo.cursor.Cursor into a dict?

The MongoDB find method does not return a single result, but a list of results in the form of a Cursor. This latter is an iterator, so you can go through it with a for loop.

For your case, just use the findOne method instead of find. This will returns you a single document as a dictionary.