Programs & Examples On #Circular reference

A circular reference is a series of references where the last object references the first, resulting in a closed loop.

How to avoid the "Circular view path" exception with Spring MVC test

Add the annotation @ResponseBody to your method return.

SQL Server - Create a copy of a database table and place it in the same database?

1st option

select *
  into ABC_1
  from ABC;

2nd option: use SSIS, that is right click on database in object explorer > all tasks > export data

  • source and target: your DB
  • source table: ABC
  • target table: ABC_1 (table will be created)

String date to xmlgregoriancalendar conversion

tl;dr

  • Use modern java.time classes as much as possible, rather than the terrible legacy classes.
  • Always specify your desired/expected time zone or offset-from-UTC rather than rely implicitly on JVM’s current default.

Example code (without exception-handling):

XMLGregorianCalendar xgc = 
    DatatypeFactory                           // Data-type converter.
    .newInstance()                            // Instantiate a converter object.
    .newXMLGregorianCalendar(                 // Converter going from `GregorianCalendar` to `XMLGregorianCalendar`.
        GregorianCalendar.from(               // Convert from modern `ZonedDateTime` class to legacy `GregorianCalendar` class.
            LocalDate                         // Modern class for representing a date-only, without time-of-day and without time zone.
            .parse( "2014-01-07" )            // Parsing strings in standard ISO 8601 format is handled by default, with no need for custom formatting pattern. 
            .atStartOfDay( ZoneOffset.UTC )   // Determine the first moment of the day as seen in UTC. Returns a `ZonedDateTime` object.
        )                                     // Returns a `GregorianCalendar` object.
    )                                         // Returns a `XMLGregorianCalendar` object.
;

Parsing date-only input string into an object of XMLGregorianCalendar class

Avoid the terrible legacy date-time classes whenever possible, such as XMLGregorianCalendar, GregorianCalendar, Calendar, and Date. Use only modern java.time classes.

When presented with a string such as "2014-01-07", parse as a LocalDate.

LocalDate.parse( "2014-01-07" )

To get a date with time-of-day, assuming you want the first moment of the day, specify a time zone. Let java.time determine the first moment of the day, as it is not always 00:00:00.0 in some zones on some dates.

LocalDate.parse( "2014-01-07" )
         .atStartOfDay( ZoneId.of( "America/Montreal" ) )

This returns a ZonedDateTime object.

ZonedDateTime zdt = 
        LocalDate
        .parse( "2014-01-07" )
        .atStartOfDay( ZoneId.of( "America/Montreal" ) )
;

zdt.toString() = 2014-01-07T00:00-05:00[America/Montreal]

But apparently, you want the start-of-day as seen in UTC (an offset of zero hours-minutes-seconds). So we specify ZoneOffset.UTC constant as our ZoneId argument.

ZonedDateTime zdt = 
        LocalDate
        .parse( "2014-01-07" )
        .atStartOfDay( ZoneOffset.UTC )
;

zdt.toString() = 2014-01-07T00:00Z

The Z on the end means UTC (an offset of zero), and is pronounced “Zulu”.

If you must work with legacy classes, convert to GregorianCalendar, a subclass of Calendar.

GregorianCalendar gc = GregorianCalendar.from( zdt ) ;

gc.toString() = java.util.GregorianCalendar[time=1389052800000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="UTC",offset=0,dstSavings=0,useDaylight=false,transitions=0,lastRule=null],firstDayOfWeek=2,minimalDaysInFirstWeek=4,ERA=1,YEAR=2014,MONTH=0,WEEK_OF_YEAR=2,WEEK_OF_MONTH=2,DAY_OF_MONTH=7,DAY_OF_YEAR=7,DAY_OF_WEEK=3,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=0,MILLISECOND=0,ZONE_OFFSET=0,DST_OFFSET=0]

Apparently, you really need an object of the legacy class XMLGregorianCalendar. If the calling code cannot be updated to use java.time, convert.

XMLGregorianCalendar xgc = 
        DatatypeFactory
        .newInstance()
        .newXMLGregorianCalendar( gc ) 
;

Actually, that code requires a try-catch.

try
{
    XMLGregorianCalendar xgc =
            DatatypeFactory
                    .newInstance()
                    .newXMLGregorianCalendar( gc );
}
catch ( DatatypeConfigurationException e )
{
    e.printStackTrace();
}

xgc = 2014-01-07T00:00:00.000Z

Putting that all together, with appropriate exception-handling.

// Given an input string such as "2014-01-07", return a `XMLGregorianCalendar` object
// representing first moment of the day on that date as seen in UTC. 
static public XMLGregorianCalendar getXMLGregorianCalendar ( String input )
{
    Objects.requireNonNull( input );
    if( input.isBlank() ) { throw new IllegalArgumentException( "Received empty/blank input string for date argument. Message # 11818896-7412-49ba-8f8f-9b3053690c5d." ) ; }
    XMLGregorianCalendar xgc = null;
    ZonedDateTime zdt = null;

    try
    {
        zdt =
                LocalDate
                        .parse( input )
                        .atStartOfDay( ZoneOffset.UTC );
    }
    catch ( DateTimeParseException e )
    {
        throw new IllegalArgumentException( "Faulty input string for date does not comply with standard ISO 8601 format. Message # 568db0ef-d6bf-41c9-8228-cc3516558e68." );
    }

    GregorianCalendar gc = GregorianCalendar.from( zdt );
    try
    {
        xgc =
                DatatypeFactory
                        .newInstance()
                        .newXMLGregorianCalendar( gc );
    }
    catch ( DatatypeConfigurationException e )
    {
        e.printStackTrace();
    }

    Objects.requireNonNull( xgc );
    return xgc ;
}

Usage.

String input = "2014-01-07";
XMLGregorianCalendar xgc = App.getXMLGregorianCalendar( input );

Dump to console.

System.out.println( "xgc = " + xgc );

xgc = 2014-01-07T00:00:00.000Z

Modern date-time classes versus legacy

Table of date-time types in Java, both modern and legacy

Date-time != String

Do not conflate a date-time value with its textual representation. We parse strings to get a date-time object, and we ask the date-time object to generate a string to represent its value. The date-time object has no ‘format’, only strings have a format.

So shift your thinking into two separate modes: model and presentation. Determine the date-value you have in mind, applying appropriate time zone, as the model. When you need to display that value, generate a string in a particular format as expected by the user.

Avoid legacy date-time classes

The Question and other Answers all use old troublesome date-time classes now supplanted by the java.time classes.

ISO 8601

Your input string "2014-01-07" is in standard ISO 8601 format.

The T in the middle separates date portion from time portion.

The Z on the end is short for Zulu and means UTC.

Fortunately, the java.time classes use the ISO 8601 formats by default when parsing/generating strings. So no need to specify a formatting pattern.

LocalDate

The LocalDate class represents a date-only value without time-of-day and without time zone.

LocalDate ld = LocalDate.parse( "2014-01-07" ) ;

ld.toString(): 2014-01-07

Start of day ZonedDateTime

If you want to see the first moment of that day, specify a ZoneId time zone to get a moment on the timeline, a ZonedDateTime. The time zone is crucial because the date varies around the globe by zone. A few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.

Never assume the day begins at 00:00:00. Anomalies such as Daylight Saving Time (DST) means the day may begin at another time-of-day such as 01:00:00. Let java.time determine the first moment.

ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = ld.atStartOfDay( z ) ;

zdt.toString(): 2014-01-07T00:00:00Z

For your desired format, generate a string using the predefined formatter DateTimeFormatter.ISO_LOCAL_DATE_TIME and then replace the T in the middle with a SPACE.

String output = zdt.format( DateTimeFormatter.ISO_LOCAL_DATE_TIME )
                   .replace( "T" , " " ) ; 

2014-01-07 00:00:00


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Gaussian fit for Python

sigma = sum(y*(x - mean)**2)

should be

sigma = np.sqrt(sum(y*(x - mean)**2))

How to insert a string which contains an "&"

There's always the chr() function, which converts an ascii code to string.

ie. something like: INSERT INTO table VALUES ( CONCAT( 'J', CHR(38), 'J' ) )

Putting an if-elif-else statement on one line?

Despite some other answers: YES it IS possible:

if expression1:
   statement1
elif expression2:
   statement2
else:
   statement3

translates to the following one liner:

statement1 if expression1 else (statement2 if expression2 else statement3)

in fact you can nest those till infinity. Enjoy ;)

How to solve error "Missing `secret_key_base` for 'production' environment" (Rails 4.1)

I had the same problem and solved it by creating an environment variable to be loaded every time I logged in to the production server, and made a mini-guide of the steps to configure it:

I was using Rails 4.1 with Unicorn v4.8.2 and when I tried to deploy my application it didn't start properly and in the unicorn.log file I found this error message:

app error: Missing `secret_key_base` for 'production' environment, set this value in `config/secrets.yml` (RuntimeError)

After some research I found out that Rails 4.1 changed the way to manage the secret_key, so if you read the secrets.yml file located at exampleRailsProject/config/secrets.yml you'll find something like this:

# Do not keep production secrets in the repository,
# instead read values from the environment.
production:
  secret_key_base: <%= ENV["SECRET_KEY_BASE"] %>

This means that Rails recommends you to use an environment variable for the secret_key_base in your production server. In order to solve this error you should follow these steps to create an environment variable for Linux (in my case Ubuntu) in your production server:

  1. In the terminal of your production server execute:

    $ RAILS_ENV=production rake secret
    

    This returns a large string with letters and numbers. Copy that, which we will refer to that code as GENERATED_CODE.

  2. Login to your server

    • If you login as the root user, find this file and edit it:

      $ vi /etc/profile
      

      Go to the bottom of the file using Shift+G (capital "G") in vi.

      Write your environment variable with the GENERATED_CODE, pressing i to insert in vi. Be sure to be in a new line at the end of the file:

      $ export SECRET_KEY_BASE=GENERATED_CODE
      

      Save the changes and close the file using Esc and then ":x" and Enter for save and exit in vi.

    • But if you login as normal user, let's call it "example_user" for this gist, you will need to find one of these other files:

      $ vi ~/.bash_profile
      $ vi ~/.bash_login
      $ vi ~/.profile
      

      These files are in order of importance, which means that if you have the first file, then you wouldn't need to edit the others. If you found these two files in your directory ~/.bash_profile and ~/.profile you only will have to write in the first one ~/.bash_profile, because Linux will read only this one and the other will be ignored.

      Then we go to the bottom of the file using Shift+G again and write the environment variable with our GENERATED_CODE using i again, and be sure add a new line at the end of the file:

      $ export SECRET_KEY_BASE=GENERATED_CODE
      

      Having written the code, save the changes and close the file using Esc again and ":x" and Enter to save and exit.

  3. You can verify that our environment variable is properly set in Linux with this command:

    $ printenv | grep SECRET_KEY_BASE
    

    or with:

    $ echo $SECRET_KEY_BASE
    

    When you execute this command, if everything went ok, it will show you the GENERATED_CODE from before. Finally with all the configuration done you should be able to deploy without problems your Rails application with Unicorn or some other tool.

When you close your shell and login again to the production server you will have this environment variable set and ready to use it.

And that's it! I hope this mini-guide helps you solve this error.

Disclaimer: I'm not a Linux or Rails guru, so if you find something wrong or any error I will be glad to fix it.

Setting background color for a JFrame

Resurrecting a thread from stasis.

In 2018 this solution works for Swing/JFrame in NetBeans (should work in any IDE :):

this.getContentPane().setBackground(Color.GREEN);

JavaScript operator similar to SQL "like"

No there isn't, but you can check out indexOf as a starting point to developing your own, and/or look into regular expressions. It would be a good idea to familiarise yourself with the JavaScript string functions.

EDIT: This has been answered before:

Emulating SQL LIKE in JavaScript

iFrame src change event detection?

Since version 3.0 of Jquery you might get an error

TypeError: url.indexOf is not a function

Which can be easily fix by doing

$('#iframe').on('load', function() {
    alert('frame has (re)loaded ');
});

expand/collapse table rows with JQuery

using jQuery it's easy...

 $('YOUR CLASS SELECTOR').click(function(){

            $(this).toggle();
});

Is there a program to decompile Delphi?

I don't think there are any machine code decompilers that produce Pascal code. Most "Delphi decompilers" parse form and RTTI data, but do not actually decompile the machine code. I can only recommend using something like DeDe (or similar software) to extract symbol information in combination with a C decompiler, then translate the decompiled C code to Delphi (there are many source code converters out there).

CodeIgniter: Load controller within controller

If you're interested, there's a well-established package out there that you can add to your Codeigniter project that will handle this:

https://bitbucket.org/wiredesignz/codeigniter-modular-extensions-hmvc/

Modular Extensions makes the CodeIgniter PHP framework modular. Modules are groups of independent components, typically model, controller and view, arranged in an application modules sub-directory, that can be dropped into other CodeIgniter applications.

OK, so the big change is that now you'd be using a modular structure - but to me this is desirable. I have used CI for about 3 years now, and can't imagine life without Modular Extensions.

Now, here's the part that deals with directly calling controllers for rendering view partials:

// Using a Module as a view partial from within a view is as easy as writing:
<?php echo modules::run('module/controller/method', $param1, $params2); ?>

That's all there is to it. I typically use this for loading little "widgets" like:

  • Event calendars
  • List of latest news articles
  • Newsletter signup forms
  • Polls

Typically I build a "widget" controller for each module and use it only for this purpose.

Your question was also one of my first questions when I started with Codeigniter. I hope this helps you out, even though it may be a bit more than you were looking for. I've been using MX ever since and haven't looked back.

Make sure to read the docs and check out the multitude of information regarding this package on the Codeigniter forums. Enjoy!

Angular 2: How to access an HTTP response body?

Can't you just refer to the _body object directly? Apparently it doesn't return any errors if used this way.

this.http.get('https://thecatapi.com/api/images/get?format=html&results_per_page=10')
            .map(res => res)
            .subscribe(res => {
                this.data = res._body;
            });

Working plunker

Escaping ampersand character in SQL string

Escape is set to \ by default, so you don't need to set it; but if you do, don't wrap it in quotes.

Ampersand is the SQL*Plus substitution variable marker; but you can change it, or more usefully in your case turn it off completely, with:

set define off

Then you don't need to bother escaping the value at all.

How to pass optional arguments to a method in C++?

It might be interesting to some of you that in case of multiple default parameters:

void printValues(int x=10, int y=20, int z=30)
{
    std::cout << "Values: " << x << " " << y << " " << z << '\n';
}

Given the following function calls:

printValues(1, 2, 3);
printValues(1, 2);
printValues(1);
printValues();

The following output is produced:

Values: 1 2 3
Values: 1 2 30
Values: 1 20 30
Values: 10 20 30

Reference: http://www.learncpp.com/cpp-tutorial/77-default-parameters/

Can I write a CSS selector selecting elements NOT having a certain class or attribute?

:not([class])

Actually, this will select anything that does not have a css class (class="css-selector") applied to it.

I made a jsfiddle demo

_x000D_
_x000D_
    h2 {color:#fff}_x000D_
    :not([class]) {color:red;background-color:blue}_x000D_
    .fake-class {color:green}
_x000D_
    <h2 class="fake-class">fake-class will be green</h2>_x000D_
    <h2 class="">empty class SHOULD be white</h2>_x000D_
    <h2>no class should be red</h2>_x000D_
    <h2 class="fake-clas2s">fake-class2 SHOULD be white</h2>_x000D_
    <h2 class="">empty class2 SHOULD be white</h2>_x000D_
    <h2>no class2 SHOULD be red</h2>
_x000D_
_x000D_
_x000D_

Is this supported? Yes : Caniuse.com (accessed 02 Jan 2020):

  • Support: 98.74%
  • Partial support: 0.1%
  • Total:98.84%

Funny edit, I was Googling for the opposite of :not. CSS negation?

selector[class]  /* the oposite of :not[]*/

jQuery ajax upload file in asp.net mvc

You can't upload files via ajax, you need to use an iFrame or some other trickery to do a full postback. This is mainly due to security concerns.

Here's a decent write-up including a sample project using SWFUpload and ASP.Net MVC by Steve Sanderson. It's the first thing I read getting this working properly with Asp.Net MVC (I was new to MVC at the time as well), hopefully it's as helpful for you.

Best way to alphanumeric check in JavaScript

I would create a String prototype method:

String.prototype.isAlphaNumeric = function() {
  var regExp = /^[A-Za-z0-9]+$/;
  return (this.match(regExp));
};

Then, the usage would be:

var TCode = document.getElementById('TCode').value;
return TCode.isAlphaNumeric()

How to set Apache Spark Executor memory

Spark executor memory is required for running your spark tasks based on the instructions given by your driver program. Basically, it requires more resources that depends on your submitted job.

Executor memory includes memory required for executing the tasks plus overhead memory which should not be greater than the size of JVM and yarn maximum container size.

Add the following parameters in spark-defaults.conf

spar.executor.cores=1

spark.executor.memory=2g

If you using any cluster management tools like cloudera manager or amabari please refresh the cluster configuration for reflecting the latest configs to all nodes in the cluster.

Alternatively, we can pass the executor core and memory value as an argument while running spark-submit command along with class and application path.

Example:

spark-submit \

  --class org.apache.spark.examples.SparkPi \

  --master yarn \

  --deploy-mode cluster \  # can be client for client mode

  --executor-memory 2G \

  --num-executors 5 \

  /path/to/examples.jar \

  1000

What is your single most favorite command-line trick using Bash?

How to list only subdirectories in the current one ?

ls -d */

It's a simple trick, but you wouldn't know how much time I needed to find that one !

Create folder with batch but only if it doesn't already exist

if exist C:\VTS\NUL echo "Folder already exists"

if not exist C:\VTS\NUL echo "Folder does not exist"

See also https://support.microsoft.com/en-us/kb/65994

(Update March 7, 2018; Microsoft article is down, archive on https://web.archive.org/web/20150609092521/https://support.microsoft.com/en-us/kb/65994 )

How to force remounting on React components?

I'm working on Crud for my app. This is how I did it Got Reactstrap as my dependency.

import React, { useState, setState } from 'react';
import 'bootstrap/dist/css/bootstrap.min.css';
import firebase from 'firebase';
// import { LifeCrud } from '../CRUD/Crud';
import { Row, Card, Col, Button } from 'reactstrap';
import InsuranceActionInput from '../CRUD/InsuranceActionInput';

const LifeActionCreate = () => {
  let [newLifeActionLabel, setNewLifeActionLabel] = React.useState();

  const onCreate = e => {
    const db = firebase.firestore();

    db.collection('actions').add({
      label: newLifeActionLabel
    });
    alert('New Life Insurance Added');
    setNewLifeActionLabel('');
  };

  return (
    <Card style={{ padding: '15px' }}>
      <form onSubmit={onCreate}>
        <label>Name</label>
        <input
          value={newLifeActionLabel}
          onChange={e => {
            setNewLifeActionLabel(e.target.value);
          }}
          placeholder={'Name'}
        />

        <Button onClick={onCreate}>Create</Button>
      </form>
    </Card>
  );
};

Some React Hooks in there

dd: How to calculate optimal blocksize?

As others have said, there is no universally correct block size; what is optimal for one situation or one piece of hardware may be terribly inefficient for another. Also, depending on the health of the disks it may be preferable to use a different block size than what is "optimal".

One thing that is pretty reliable on modern hardware is that the default block size of 512 bytes tends to be almost an order of magnitude slower than a more optimal alternative. When in doubt, I've found that 64K is a pretty solid modern default. Though 64K usually isn't THE optimal block size, in my experience it tends to be a lot more efficient than the default. 64K also has a pretty solid history of being reliably performant: You can find a message from the Eug-Lug mailing list, circa 2002, recommending a block size of 64K here: http://www.mail-archive.com/[email protected]/msg12073.html

For determining THE optimal output block size, I've written the following script that tests writing a 128M test file with dd at a range of different block sizes, from the default of 512 bytes to a maximum of 64M. Be warned, this script uses dd internally, so use with caution.

dd_obs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_obs_testfile}
TEST_FILE_EXISTS=0
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=1; fi
TEST_FILE_SIZE=134217728

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Calculate number of segments required to copy
  COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))

  if [ $COUNT -le 0 ]; then
    echo "Block size of $BLOCK_SIZE estimated to require $COUNT blocks, aborting further tests."
    break
  fi

  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Create a test file with the specified block size
  DD_RESULT=$(dd if=/dev/zero of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync 2>&1 1>/dev/null)

  # Extract the transfer rate from dd's STDERR output
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  # Clean up the test file if we created one
  if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

  # Output the result
  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

View on GitHub

I've only tested this script on a Debian (Ubuntu) system and on OSX Yosemite, so it will probably take some tweaking to make work on other Unix flavors.

By default the command will create a test file named dd_obs_testfile in the current directory. Alternatively, you can provide a path to a custom test file by providing a path after the script name:

$ ./dd_obs_test.sh /path/to/disk/test_file

The output of the script is a list of the tested block sizes and their respective transfer rates like so:

$ ./dd_obs_test.sh
block size : transfer rate
       512 : 11.3 MB/s
      1024 : 22.1 MB/s
      2048 : 42.3 MB/s
      4096 : 75.2 MB/s
      8192 : 90.7 MB/s
     16384 : 101 MB/s
     32768 : 104 MB/s
     65536 : 108 MB/s
    131072 : 113 MB/s
    262144 : 112 MB/s
    524288 : 133 MB/s
   1048576 : 125 MB/s
   2097152 : 113 MB/s
   4194304 : 106 MB/s
   8388608 : 107 MB/s
  16777216 : 110 MB/s
  33554432 : 119 MB/s
  67108864 : 134 MB/s

(Note: The unit of the transfer rates will vary by OS)

To test optimal read block size, you could use more or less the same process, but instead of reading from /dev/zero and writing to the disk, you'd read from the disk and write to /dev/null. A script to do this might look like so:

dd_ibs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_ibs_testfile}
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=$?; fi
TEST_FILE_SIZE=134217728

# Exit if file exists
if [ -e $TEST_FILE ]; then
  echo "Test file $TEST_FILE exists, aborting."
  exit 1
fi
TEST_FILE_EXISTS=1

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Create test file
echo 'Generating test file...'
BLOCK_SIZE=65536
COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))
dd if=/dev/urandom of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync > /dev/null 2>&1

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Read test file out to /dev/null with specified block size
  DD_RESULT=$(dd if=$TEST_FILE of=/dev/null bs=$BLOCK_SIZE 2>&1 1>/dev/null)

  # Extract transfer rate
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

# Clean up the test file if we created one
if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

View on GitHub

An important difference in this case is that the test file is a file that is written by the script. Do not point this command at an existing file or the existing file will be overwritten with zeroes!

For my particular hardware I found that 128K was the most optimal input block size on a HDD and 32K was most optimal on a SSD.

Though this answer covers most of my findings, I've run into this situation enough times that I wrote a blog post about it: http://blog.tdg5.com/tuning-dd-block-size/ You can find more specifics on the tests I performed there.

android - how to convert int to string and place it in a EditText?

Try using String.format() :

ed = (EditText) findViewById (R.id.box); 
int x = 10; 
ed.setText(String.format("%s",x)); 

Passing parameters to a JDBC PreparedStatement

You can use '?' to set custom parameters in string using PreparedStatments.

statement =con.prepareStatement("SELECT * from employee WHERE  userID = ?");
statement.setString(1, userID);
ResultSet rs = statement.executeQuery();

If you directly pass userID in query as you are doing then it may get attacked by SQL INJECTION Attack.

Using ListView : How to add a header view?

You can add as many headers as you like by calling addHeaderView() multiple times. You have to do it before setting the adapter to the list view.

And yes you can add header something like this way:

LayoutInflater inflater = getLayoutInflater();
ViewGroup header = (ViewGroup)inflater.inflate(R.layout.header, myListView, false);
myListView.addHeaderView(header, null, false);

SqlDataAdapter vs SqlDataReader

A SqlDataAdapter is typically used to fill a DataSet or DataTable and so you will have access to the data after your connection has been closed (disconnected access).

The SqlDataReader is a fast forward-only and connected cursor which tends to be generally quicker than filling a DataSet/DataTable.

Furthermore, with a SqlDataReader, you deal with your data one record at a time, and don't hold any data in memory. Obviously with a DataTable or DataSet, you do have a memory allocation overhead.

If you don't need to keep your data in memory, so for rendering stuff only, go for the SqlDataReader. If you want to deal with your data in a disconnected fashion choose the DataAdapter to fill either a DataSet or DataTable.

Using Mockito, how do I verify a method was a called with a certain argument?

First you need to create a mock m_contractsDao and set it up. Assuming that the class is ContractsDao:

ContractsDao mock_contractsDao = mock(ContractsDao.class);
when(mock_contractsDao.save(any(String.class))).thenReturn("Some result");

Then inject the mock into m_orderSvc and call your method.

m_orderSvc.m_contractsDao = mock_contractsDao;
m_prog = new ProcessOrdersWorker(m_orderSvc, m_opportunitySvc, m_myprojectOrgSvc);
m_prog.work(); 

Finally, verify that the mock was called properly:

verify(mock_contractsDao, times(1)).save("Parameter I'm expecting");

Deep cloning objects

As nearly all of the answers to this question have been unsatisfactory or plainly don't work in my situation, I have authored AnyClone which is entirely implemented with reflection and solved all of the needs here. I was unable to get serialization to work in a complicated scenario with complex structure, and IClonable is less than ideal - in fact it shouldn't even be necessary.

Standard ignore attributes are supported using [IgnoreDataMember], [NonSerialized]. Supports complex collections, properties without setters, readonly fields etc.

I hope it helps someone else out there who ran into the same problems I did.

PHP: Get the key from an array in a foreach loop

you need nested foreach loops

foreach($samplearr as $key => $item){
   echo $key;
    foreach($item as $detail){
       echo $detail['value1'] . " " . $detail['value2']
     }
 }

How do I set a textbox's value using an anchor with jQuery?

To assign value of a text box whose id is ?textbox? in jQuery please do the following

$("#textbox").val('Blah');

How do I use cx_freeze?

  • Add import sys as the new topline
  • You misspelled "executables" on the last line.
  • Remove script = on last line.

The code should now look like:

import sys
from cx_Freeze import setup, Executable

setup(
    name = "On Dijkstra's Algorithm",
    version = "3.1",
    description = "A Dijkstra's Algorithm help tool.",
    executables = [Executable("Main.py", base = "Win32GUI")])

Use the command prompt (cmd) to run python setup.py build. (Run this command from the folder containing setup.py.) Notice the build parameter we added at the end of the script call.

Getting individual colors from a color map in matplotlib

For completeness these are the cmap choices I encountered so far:

Accent, Accent_r, Blues, Blues_r, BrBG, BrBG_r, BuGn, BuGn_r, BuPu, BuPu_r, CMRmap, CMRmap_r, Dark2, Dark2_r, GnBu, GnBu_r, Greens, Greens_r, Greys, Greys_r, OrRd, OrRd_r, Oranges, Oranges_r, PRGn, PRGn_r, Paired, Paired_r, Pastel1, Pastel1_r, Pastel2, Pastel2_r, PiYG, PiYG_r, PuBu, PuBuGn, PuBuGn_r, PuBu_r, PuOr, PuOr_r, PuRd, PuRd_r, Purples, Purples_r, RdBu, RdBu_r, RdGy, RdGy_r, RdPu, RdPu_r, RdYlBu, RdYlBu_r, RdYlGn, RdYlGn_r, Reds, Reds_r, Set1, Set1_r, Set2, Set2_r, Set3, Set3_r, Spectral, Spectral_r, Wistia, Wistia_r, YlGn, YlGnBu, YlGnBu_r, YlGn_r, YlOrBr, YlOrBr_r, YlOrRd, YlOrRd_r, afmhot, afmhot_r, autumn, autumn_r, binary, binary_r, bone, bone_r, brg, brg_r, bwr, bwr_r, cividis, cividis_r, cool, cool_r, coolwarm, coolwarm_r, copper, copper_r, cubehelix, cubehelix_r, flag, flag_r, gist_earth, gist_earth_r, gist_gray, gist_gray_r, gist_heat, gist_heat_r, gist_ncar, gist_ncar_r, gist_rainbow, gist_rainbow_r, gist_stern, gist_stern_r, gist_yarg, gist_yarg_r, gnuplot, gnuplot2, gnuplot2_r, gnuplot_r, gray, gray_r, hot, hot_r, hsv, hsv_r, inferno, inferno_r, jet, jet_r, magma, magma_r, nipy_spectral, nipy_spectral_r, ocean, ocean_r, pink, pink_r, plasma, plasma_r, prism, prism_r, rainbow, rainbow_r, seismic, seismic_r, spring, spring_r, summer, summer_r, tab10, tab10_r, tab20, tab20_r, tab20b, tab20b_r, tab20c, tab20c_r, terrain, terrain_r, twilight, twilight_r, twilight_shifted, twilight_shifted_r, viridis, viridis_r, winter, winter_r

How can I delete a file from a Git repository?

The answer by Greg Hewgill, that was edited by Johannchopin helped me, as I did not care about removing the file from the history completely. In my case, it was a directory, so the only change I did was using:

git rm -r --cached myDirectoryName

instead of "git rm --cached file1.txt" ..followed by:

git commit -m "deleted myDirectoryName from git"
git push origin branch_name

Thanks Greg Hewgill and Johannchopin!

angular-cli server - how to proxy API requests to another server?

EDIT: THIS NO LONGER WORKS IN CURRENT ANGULAR-CLI

See answer from @imal hasaranga perera for up-to-date solution


The server in angular-cli comes from the ember-cli project. To configure the server, create an .ember-cli file in the project root. Add your JSON config in there:

{
   "proxy": "https://api.example.com"
}

Restart the server and it will proxy all requests there.

For example, I'm making relative requests in my code to /v1/foo/123, which is being picked up at https://api.example.com/v1/foo/123.

You can also use a flag when you start the server: ng serve --proxy https://api.example.com

Current for angular-cli version: 1.0.0-beta.0

Enum "Inheritance"

This is not possible (as @JaredPar already mentioned). Trying to put logic to work around this is a bad practice. In case you have a base class that have an enum, you should list of all possible enum-values there, and the implementation of class should work with the values that it knows.

E.g. Supposed you have a base class BaseCatalog, and it has an enum ProductFormats (Digital, Physical). Then you can have a MusicCatalog or BookCatalog that could contains both Digital and Physical products, But if the class is ClothingCatalog, it should only contains Physical products.

HAProxy redirecting http to https (ssl)

Like Jay Taylor said, HAProxy 1.5-dev has the redirect scheme configuration directive, which accomplishes exactly what you need.

However, if you are unable to use 1.5, and if you're up for compiling HAProxy from source, I backported the redirect scheme functionality so it works in 1.4. You can get the patch here: http://marc.info/?l=haproxy&m=138456233430692&w=2

Python PDF library

There is also http://appyframework.org/pod.html which takes a LibreOffice or OpenOffice document as template and can generate pdf, rtf, odt ... To generate pdf it requires a headless OOo on some server. Documentation is concise but relatively complete. http://appyframework.org/podWritingTemplates.html If you need advice, the author is rather helpful.

array of string with unknown size

If you will later know the length of the array you can create the initial array like this:

String[] array;

And later when you know the length you can finish initializing it like this

array = new String[42];

How to use the CSV MIME-type?

You are not specifying a language or framework, but the following header is used for file downloads:

"Content-Disposition: attachment; filename=abc.csv"

Clearing Magento Log Data

How Magento log cleaning can be done both manually, automatically and other Magento database maintenance. Below the three things are most important of Magento database maintenance and optimization techniques;

  • Log Cleaning
  • Smart use of MySQL updated versions
  • Buffer pool size settings

To get more information http://blog.contus.com/magento-database-maintenance-and-optimization/

Getting list of pixel values from PIL

pixVals = list(pilImg.getdata())

output is a list of all RGB values from the picture:

[(248, 246, 247), (246, 248, 247), (244, 248, 247), (244, 248, 247), (246, 248, 247), (248, 246, 247), (250, 246, 247), (251, 245, 247), (253, 244, 247), (254, 243, 247)]

Is there a Java equivalent or methodology for the typedef keyword in C++?

In some cases, a binding annotation may be just what you're looking for:

https://github.com/google/guice/wiki/BindingAnnotations

Or if you don't want to depend on Guice, just a regular annotation might do.

Trusting all certificates with okHttp

You should never look to override certificate validation in code! If you need to do testing, use an internal/test CA and install the CA root certificate on the device or emulator. You can use BurpSuite or Charles Proxy if you don't know how to setup a CA.

Task<> does not contain a definition for 'GetAwaiter'

You could still use framework 4.0 but you have to include getawaiter for the classes:

MethodName(parameters).ConfigureAwait(false).GetAwaiter().GetResult();

linq query to return distinct field values from a list of objects

If just want to user pure Linq, you can use groupby:

List<obj> distinct =
  objs.GroupBy(car => car.typeID).Select(g => g.First()).ToList();

If you want a method to be used all across the app, similar to what MoreLinq does:

public static IEnumerable<TSource> DistinctBy<TSource, TKey>
    (this IEnumerable<TSource> source, Func<TSource, TKey> keySelector)
{
    HashSet<TKey> seenKeys = new HashSet<TKey>();
    foreach (TSource element in source)
    {
        if (!seenKeys.Contains(keySelector(element)))
        {
            seenKeys.Add(keySelector(element));
            yield return element;
        }
    }
}

Using this method to find the distinct values using just the Id property, you could use:

var query = objs.DistinctBy(p => p.TypeId);

you can use multiple properties:

var query = objs.DistinctBy(p => new { p.TypeId, p.Name });

JavaScript getElementByID() not working

At the point you are calling your function, the rest of the page has not rendered and so the element is not in existence at that point. Try calling your function on window.onload maybe. Something like this:

<html>
<head>
    <title></title>
    <script type="text/javascript">
        window.onload = function(){
           var refButton = document.getElementById("btnButton");

            refButton.onclick = function() {
                alert('I am clicked!');
            }
        };
    </script>
</head>
<body>
    <form id="form1">
    <div>
        <input id="btnButton" type="button" value="Click me"/>
    </div>
    </form>
</body>
</html>

Query based on multiple where clauses in Firebase

Firebase doesn't allow querying with multiple conditions. However, I did find a way around for this:

We need to download the initial filtered data from the database and store it in an array list.

                Query query = databaseReference.orderByChild("genre").equalTo("comedy");
                databaseReference.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                        ArrayList<Movie> movies = new ArrayList<>();
                        for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                            String lead = dataSnapshot1.child("lead").getValue(String.class);
                            String genre = dataSnapshot1.child("genre").getValue(String.class);

                            movie = new Movie(lead, genre);

                            movies.add(movie);

                        }

                        filterResults(movies, "Jack Nicholson");

                        }

                    }

                    @Override
                    public void onCancelled(@NonNull DatabaseError databaseError) {

                    }
                });

Once we obtain the initial filtered data from the database, we need to do further filter in our backend.

public void filterResults(final List<Movie> list,  final String genre) {
        List<Movie> movies = new ArrayList<>();
        movies = list.stream().filter(o -> o.getLead().equals(genre)).collect(Collectors.toList());
        System.out.println(movies);

        employees.forEach(movie -> System.out.println(movie.getFirstName()));
    }

How do I assign a port mapping to an existing Docker container?

If by "existing" you mean "running", then it's not (currently) possible to add a port mapping.

You can, however, dynamically add a new network interface with e.g. Pipework, if you need to expose a service in a running container without stopping/restarting it.

Checking from shell script if a directory contains files

This may be a really late response but here is a solution that works. This line only recognizes th existance of files! It will not give you a false positive if directories exist.

if find /path/to/check/* -maxdepth 0 -type f | read
  then echo "Files Exist"
fi

Compress images on client side before uploading

You might be able to resize the image with canvas and export it using dataURI. Not sure about compression, though.

Take a look at this: Resizing an image in an HTML5 canvas

'printf' vs. 'cout' in C++

I'd like to point out that if you want to play with threads in C++, if you use cout you can get some interesting results.

Consider this code:

#include <string>
#include <iostream>
#include <thread>

using namespace std;

void task(int taskNum, string msg) {
    for (int i = 0; i < 5; ++i) {
        cout << "#" << taskNum << ": " << msg << endl;
    }
}

int main() {
    thread t1(task, 1, "AAA");
    thread t2(task, 2, "BBB");
    t1.join();
    t2.join();
    return 0;
}

// g++ ./thread.cpp -o thread.out -ansi -pedantic -pthread -std=c++0x

Now, the output comes all shuffled. It can yield different results too, try executing several times:

##12::  ABABAB

##12::  ABABAB

##12::  ABABAB

##12::  ABABAB

##12::  ABABAB

You can use printf to get it right, or you can use mutex.

#1: AAA
#2: BBB
#1: AAA
#2: BBB
#1: AAA
#2: BBB
#1: AAA
#2: BBB
#1: AAA
#2: BBB

Have fun!

Laravel Eloquent LEFT JOIN WHERE NULL

I would dump your query so you can take a look at the SQL that was actually executed and see how that differs from what you wrote.

You should be able to do that with the following code:

$queries = DB::getQueryLog();
$last_query = end($queries);
var_dump($last_query);
die();

Hopefully that should give you enough information to allow you to figure out what's gone wrong.

What's "this" in JavaScript onclick?

It refers to the element in the DOM to which the onclick attribute belongs:

<script type="text/javascript"
        src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js">
</script>
<script type="text/javascript">
function func(e) {
  $(e).text('there');
}
</script>
<a onclick="func(this)">here</a>

(This example uses jQuery.)

Python+OpenCV: cv2.imwrite

wtluo, great ! May I propose a slight modification of your code 2. ? Here it is:

for i, detected_box in enumerate(detect_boxes):
    box = detected_box["box"]
    face_img = img[ box[1]:box[1] + box[3], box[0]:box[0] + box[2] ]
    cv2.imwrite("face-{:03d}.jpg".format(i+1), face_img)

What is a tracking branch?

Below are my personal learning notes on GIT tracking branches, hopefully it will be helpful for future visitors:

enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here


Tracking branches and "git fetch":

enter image description here enter image description here enter image description here

How to force Chrome browser to reload .css file while debugging in Visual Studio?

Press SHIFT+F5.

It is working for me with Chrome version 54.

Why is System.Web.Mvc not listed in Add References?

Check these step:

  1. Check MVC is installed properly.
  2. Check the project's property and see what is the project Target Framework. If the target framework is not set to .Net Framework 4, set it.

Note: if target framework is set to .Net Framework 4 Client Profile, it will not list MVC reference on references list. You can find different between .Net Framework 4 and .Net Framework 4 Client Profile here.

The .NET Framework 4 Client Profile is a subset of the .NET Framework 4 that is optimized for client applications. It provides functionality for most client applications, including Windows Presentation Foundation (WPF), Windows Forms, Windows Communication Foundation (WCF), and ClickOnce features. This enables faster deployment and a smaller install package for applications that target the .NET Framework 4 Client Profile.

How to force open links in Chrome not download them?

Great question.

It can be achieved via an extension:

Should import statements always be at the top of a module?

It's a tradeoff, that only the programmer can decide to make.

Case 1 saves some memory and startup time by not importing the datetime module (and doing whatever initialization it might require) until needed. Note that doing the import 'only when called' also means doing it 'every time when called', so each call after the first one is still incurring the additional overhead of doing the import.

Case 2 save some execution time and latency by importing datetime beforehand so that not_often_called() will return more quickly when it is called, and also by not incurring the overhead of an import on every call.

Besides efficiency, it's easier to see module dependencies up front if the import statements are ... up front. Hiding them down in the code can make it more difficult to easily find what modules something depends on.

Personally I generally follow the PEP except for things like unit tests and such that I don't want always loaded because I know they aren't going to be used except for test code.

Symfony - generate url with parameter in controller

Get the router from the container.

$router = $this->get('router');

Then use the router to generate the Url

$uri = $router->generate('blog_show', array('slug' => 'my-blog-post'));

Child inside parent with min-height: 100% not inheriting height

Although display: flex; has been suggested here, consider using display: grid; now that it's widely supported. By default, the only child of a grid will entirely fill its parent.

_x000D_
_x000D_
html, body {_x000D_
  height: 100%;_x000D_
  margin: 0;_x000D_
  padding: 0; /* Don't forget Safari */_x000D_
}_x000D_
_x000D_
#containment {_x000D_
  display: grid;_x000D_
  min-height: 100%;_x000D_
  background: pink;_x000D_
}_x000D_
_x000D_
#containment-shadow-left {_x000D_
  background: aqua;_x000D_
}
_x000D_
_x000D_
_x000D_

how to remove the dotted line around the clicked a element in html

To remove all doted outline, including those in bootstrap themes.

a, a:active, a:focus, 
button, button:focus, button:active, 
.btn, .btn:focus, .btn:active:focus, .btn.active:focus, .btn.focus, .btn.focus:active, .btn.active.focus {
    outline: none;
    outline: 0;
}

input::-moz-focus-inner {
    border: 0;
}

Note: You should add link href for bootstrap css before the main css, so bootstrap doesn't override your style.

bash: mkvirtualenv: command not found

On Windows 7 and Git Bash this helps me:

  1. Create a ~/.bashrc file (under your user home folder)
  2. Add line export WORKON_HOME=$HOME/.virtualenvs (you must create this folder if it doesn't exist)
  3. Add line source "C:\Program Files (x86)\Python36-32\Scripts\virtualenvwrapper.sh" (change path for your virtualenvwrapper.sh)

Restart your git bash and mkvirtualenv command now will work nicely.

How to delete the first row of a dataframe in R?

dat <- dat[-1, ] worked but it killed my dataframe, changing it into another type. Had to instead use dat <- data.frame(dat[-1, ]) but this is possibly a special case as this dataframe initially had only one column.

What is Gradle in Android Studio?

In plain terms, Gradle is a tool provided by Android Studio in order to implement two important processes:

  1. Build our projects
  2. Package AndroidManifest.xml,res folder,and binary code into a specially formatted zip file called APK

How to close existing connections to a DB

in restore wizard click "close existing connections to destination database"

in Detach Database wizard click "Drop connection" item.

How do I authenticate a WebClient request?

You need to give the WebClient object the credentials. Something like this...

 WebClient client = new WebClient();
 client.Credentials = new NetworkCredential("username", "password");

What is path of JDK on Mac ?

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

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

Check this earlier SO post: JDK on OSX 10.7 Lion

Validate phone number with JavaScript

/^\+?1?\s*?\(?\d{3}(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$/

Although this post is an old but want to leave my contribuition. these are accepted: 5555555555 555-555-5555 (555)555-5555 1(555)555-5555 1 555 555 5555 1 555-555-5555 1 (555) 555-5555

these are not accepted:

555-5555 -> to accept this use: ^\+?1?\s*?\(?(\d{3})?(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$

5555555 -> to accept this use: ^\+?1?\s*?\(?(\d{3})?(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$

1 555)555-5555 123**&!!asdf# 55555555 (6505552368) 2 (757) 622-7382 0 (757) 622-7382 -1 (757) 622-7382 2 757 622-7382 10 (757) 622-7382 27576227382 (275)76227382 2(757)6227382 2(757)622-7382 (555)5(55?)-5555

this is the code I used:

function telephoneCheck(str) {
  var patt = new RegExp(/^\+?1?\s*?\(?\d{3}(?:\)|[-|\s])?\s*?\d{3}[-|\s]?\d{4}$/);
  return patt.test(str);
}

telephoneCheck("+1 555-555-5555");

hibernate: LazyInitializationException: could not initialize proxy

See my article. I had the same problem - LazyInitializationException - and here's the answer I finally came up with:
http://community.jboss.org/wiki/LazyInitializationExceptionovercome
Setting lazy=false is not the answer - it can load everything all at once, and that's not necessarily good. Example:
1 record table A references:
5 records table B references:
25 records table C references:
125 records table D
...
etc. This is but one example of what can go wrong.
--Tim Sabin

Where are SQL Server connection attempts logged?

If you'd like to track only failed logins, you can use the SQL Server Audit feature (available in SQL Server 2008 and above). You will need to add the SQL server instance you want to audit, and check the failed login operation to audit.

Note: tracking failed logins via SQL Server Audit has its disadvantages. For example - it doesn't provide the names of client applications used.

If you want to audit a client application name along with each failed login, you can use an Extended Events session.

To get you started, I recommend reading this article: http://www.sqlshack.com/using-extended-events-review-sql-server-failed-logins/

Why number 9 in kill -9 command in unix?

why kill -9 : the number 9 in the list of signals has been chosen to be SIGKILL in reference to "kill the 9 lives of a cat".

Visual Studio 6 Windows Common Controls 6.0 (sp6) Windows 7, 64 bit

I believe it may be related to a issue in which Microsoft released a update to the MScomCtlLib which was incorrectly patched by microsoft, causing registry errors.

I believe if you follow the advice laid out in:

https://support.microsoft.com/fr-fr/kb/2597986

How do I solve this error, "error while trying to deserialize parameter"

In our case the problem was that we change the default root namespace name.

Project Configuration screen

This is the Project Configuration screen

We finally decided to back to the original name and the problem was solved.

The problem actually was the dots in the Root namespace. With two dots (Name.Child.Child) it doesnt work. But with one (Name.ChidChild) works.

static and extern global variables in C and C++

Global variables are not extern nor static by default on C and C++. When you declare a variable as static, you are restricting it to the current source file. If you declare it as extern, you are saying that the variable exists, but are defined somewhere else, and if you don't have it defined elsewhere (without the extern keyword) you will get a link error (symbol not found).

Your code will break when you have more source files including that header, on link time you will have multiple references to varGlobal. If you declare it as static, then it will work with multiple sources (I mean, it will compile and link), but each source will have its own varGlobal.

What you can do in C++, that you can't in C, is to declare the variable as const on the header, like this:

const int varGlobal = 7;

And include in multiple sources, without breaking things at link time. The idea is to replace the old C style #define for constants.

If you need a global variable visible on multiple sources and not const, declare it as extern on the header, and then define it, this time without the extern keyword, on a source file:

Header included by multiple files:

extern int varGlobal;

In one of your source files:

int varGlobal = 7;

How do we update URL or query strings using javascript/jQuery without reloading the page?

Plain javascript: document.location = 'http://www.google.com';

This will cause a browser refresh though - consider using hashes if you're in need of having the URL updated to implement some kind of browsing history without reloading the page. You might want to look into jQuery.hashchange if this is the case.

How to add row in JTable?

The TableModel behind the JTable handles all of the data behind the table. In order to add and remove rows from a table, you need to use a DefaultTableModel

To create the table with this model:

JTable table = new JTable(new DefaultTableModel(new Object[]{"Column1", "Column2"}));

To add a row:

DefaultTableModel model = (DefaultTableModel) table.getModel();
model.addRow(new Object[]{"Column 1", "Column 2", "Column 3"});

You can also remove rows with this method.

Full details on the DefaultTableModel can be found here

Is it good practice to use the xor operator for boolean checks?

I think you've answered your own question - if you get strange looks from people, it's probably safer to go with the more explicit option.

If you need to comment it, then you're probably better off replacing it with the more verbose version and not making people ask the question in the first place.

How do I use itertools.groupby()?

The example on the Python docs is quite straightforward:

groups = []
uniquekeys = []
for k, g in groupby(data, keyfunc):
    groups.append(list(g))      # Store group iterator as a list
    uniquekeys.append(k)

So in your case, data is a list of nodes, keyfunc is where the logic of your criteria function goes and then groupby() groups the data.

You must be careful to sort the data by the criteria before you call groupby or it won't work. groupby method actually just iterates through a list and whenever the key changes it creates a new group.

Read from file or stdin

First, ask the program to tell you what is wrong by checking the errno, which is set on failure, such as during fseek or ftell.

Others (tonio & LatinSuD) have explained the mistake with handling stdin versus checking for a filename. Namely, first check argc (argument count) to see if there are any command line parameters specified if (argc > 1), treating - as a special case meaning stdin.

If no parameters are specified, then assume input is (going) to come from stdin, which is a stream not file, and the fseek function fails on it.

In the case of a stream, where you cannot use file-on-disk oriented library functions (i.e. fseek and ftell), you simply have to count the number of bytes read (including trailing newline characters) until receiving EOF (end-of-file).

For usage with large files you could speed it up by using fgets to a char array for more efficient reading of the bytes in a (text) file. For a binary file you need to use fopen(const char* filename, "rb") and use fread instead of fgetc/fgets.

You could also check the for feof(stdin) / ferror(stdin) when using the byte-counting method to detect any errors when reading from a stream.

The sample below should be C99 compliant and portable.

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

long getSizeOfInput(FILE *input){
   long retvalue = 0;
   int c;

   if (input != stdin) {
      if (-1 == fseek(input, 0L, SEEK_END)) {
         fprintf(stderr, "Error seek end: %s\n", strerror(errno));
         exit(EXIT_FAILURE);
      }
      if (-1 == (retvalue = ftell(input))) {
         fprintf(stderr, "ftell failed: %s\n", strerror(errno));
         exit(EXIT_FAILURE);
      }
      if (-1 == fseek(input, 0L, SEEK_SET)) {
         fprintf(stderr, "Error seek start: %s\n", strerror(errno));
         exit(EXIT_FAILURE);
      }
   } else {
      /* for stdin, we need to read in the entire stream until EOF */
      while (EOF != (c = fgetc(input))) {
         retvalue++;
      }
   }

   return retvalue;
}

int main(int argc, char **argv) {
   FILE *input;

   if (argc > 1) {
      if(!strcmp(argv[1],"-")) {
         input = stdin;
      } else {
         input = fopen(argv[1],"r");
         if (NULL == input) {
            fprintf(stderr, "Unable to open '%s': %s\n",
                  argv[1], strerror(errno));
            exit(EXIT_FAILURE);
         }
      }
   } else {
      input = stdin;
   }

   printf("Size of file: %ld\n", getSizeOfInput(input));

   return EXIT_SUCCESS;
}

java.net.ConnectException: failed to connect to /192.168.253.3 (port 2468): connect failed: ECONNREFUSED (Connection refused)

My problem was solved after turning Off Windows Firewall Defender in public network as I was connected with that network.

Remove an element from a Bash array

To avoid conflicts with array index using unset - see https://stackoverflow.com/a/49626928/3223785 and https://stackoverflow.com/a/47798640/3223785 for more information - reassign the array to itself: ARRAY_VAR=(${ARRAY_VAR[@]}).

#!/bin/bash

ARRAY_VAR=(0 1 2 3 4 5 6 7 8 9)
unset ARRAY_VAR[5]
unset ARRAY_VAR[4]
ARRAY_VAR=(${ARRAY_VAR[@]})
echo ${ARRAY_VAR[@]}
A_LENGTH=${#ARRAY_VAR[*]}
for (( i=0; i<=$(( $A_LENGTH -1 )); i++ )) ; do
    echo ""
    echo "INDEX - $i"
    echo "VALUE - ${ARRAY_VAR[$i]}"
done

exit 0

[Ref.: https://tecadmin.net/working-with-array-bash-script/ ]

How to check if "Radiobutton" is checked?

You can use switch like this:

XML Layout

<RadioGroup
            android:id="@+id/RG"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <RadioButton
                android:id="@+id/R1"
                android:layout_width="wrap_contnet"
                android:layout_height="wrap_content"
                android:text="R1" />

            <RadioButton
                android:id="@+id/R2"
                android:layout_width="wrap_contnet"
                android:layout_height="wrap_content"
                android:text="R2" />
</RadioGroup>

And JAVA Activity

switch (RG.getCheckedRadioButtonId()) {
        case R.id.R1:
            regAuxiliar = ultimoRegistro;
        case R.id.R2:
            regAuxiliar = objRegistro;
        default:
            regAuxiliar = null; // none selected
    }

You will also need to implement an onClick function with button or setOnCheckedChangeListener function to get required functionality.

How to slice a Pandas Data Frame by position?

df.ix[10,:] gives you all the columns from the 10th row. In your case you want everything up to the 10th row which is df.ix[:9,:]. Note that the right end of the slice range is inclusive: http://pandas.sourceforge.net/gotchas.html#endpoints-are-inclusive

How to do a num_rows() on COUNT query in codeigniter?

num_rows on your COUNT() query will literally ALWAYS be 1. It is an aggregate function without a GROUP BY clause, so all rows are grouped together into one. If you want the value of the count, you should give it an identifier SELECT COUNT(*) as myCount ..., then use your normal method of accessing a result (the first, only result) and get it's 'myCount' property.

Javascript - sort array based on another array

You could try this method.

const sortListByRanking = (rankingList, listToSort) => {
  let result = []

  for (let id of rankingList) {
    for (let item of listToSort) {
      if (item && item[1] === id) {
        result.push(item)
      }
    }
  }

  return result
}

Set default syntax to different filetype in Sublime Text 2

You can turn on syntax highlighting based on the contents of the file.

For example, my Makefiles regardless of their extension the first line as follows:

#-*-Makefile-*- vim:syntax=make

This is typical practice for other editors such as vim.

However, for this to work you need to modify the Makefile.tmLanguage file.

  1. Find the file (for Sublime Text 3 in Ubuntu) at:

    /opt/sublime_text/Packages/Makefile.sublime-package
    

Note, that is really a zip file. Copy it, rename with .zip at the end, and extract the Makefile.tmLanguage file from it.

  1. Edit the new Makefile.tmLanguage by adding the "firstLineMatch" key and string after the "fileTypes" section. In the example below, the last two lines are new (should be added by you). The <string> section holds the regular expression, that will enable syntax highlighting for the files that match the first line. This expression recognizes two patterns: "-*-Makefile-*-" and "vim:syntax=make".

    ...
    <key>fileTypes</key>
    <array>
        <string>GNUmakefile</string>
        <string>makefile</string>
        <string>Makefile</string>
        <string>OCamlMakefile</string>
        <string>make</string>
    </array>
    
    <key>firstLineMatch</key>
    <string>^#\s*-\*-Makefile-\*-|^#.*\s*vim:syntax=make</string>
    
  2. Place the modified Makefile.tmLanguage in the User settings directory:

    ~/.config/sublime-text-3/Packages/User/Makefile.tmLanguage
    

All the files matching the first line rule should turn the syntax highlighting on when opened.

How can I export a GridView.DataSource to a datatable or dataset?

If you do gridview.bind() at:

if(!IsPostBack)

{

//your gridview bind code here...

}

Then you can use DataTable dt = Gridview1.DataSource as DataTable; in function to retrieve datatable.

But I bind the datatable to gridview when i click button, and recording to Microsoft document:

HTTP is a stateless protocol. This means that a Web server treats each HTTP request for a page as an independent request. The server retains no knowledge of variable values that were used during previous requests.

If you have same condition, then i will recommend you to use Session to persist the value.

Session["oldData"]=Gridview1.DataSource;

After that you can recall the value when the page postback again.

DataTable dt=(DataTable)Session["oldData"];

References: https://msdn.microsoft.com/en-us/library/ms178581(v=vs.110).aspx#Anchor_0

https://www.c-sharpcorner.com/UploadFile/225740/introduction-of-session-in-Asp-Net/

How to declare an array of strings in C++?

You can use the begin and end functions from the Boost range library to easily find the ends of a primitive array, and unlike the macro solution, this will give a compile error instead of broken behaviour if you accidentally apply it to a pointer.

const char* array[] = { "cat", "dog", "horse" };
vector<string> vec(begin(array), end(array));

How to convert a huge list-of-vector to a matrix more efficiently?

This should be equivalent to your current code, only a lot faster:

output <- matrix(unlist(z), ncol = 10, byrow = TRUE)

Difference between web server, web container and application server

A Web application runs within a Web container of a Web server. The Web container provides the runtime environment through components that provide naming context and life cycle management. Some Web servers may also provide additional services such as security and concurrency control. A Web server may work with an EJB server to provide some of those services. A Web server, however, does not need to be located on the same machine as an EJB server.

Web applications are composed of web components and other data such as HTML pages. Web components can be servlets, JSP pages created with the JavaServer Pages™ technology, web filters, and web event listeners. These components typically execute in a web server and may respond to HTTP requests from web clients. Servlets, JSP pages, and filters may be used to generate HTML pages that are an application’s user interface. They may also be used to generate XML or other format data that is consumed by other application components.

Source: http://www.service-architecture.com/articles/application-servers/j2ee_web_server_or_container.html

How can I convert an RGB image into grayscale in Python?

How about doing it with Pillow:

from PIL import Image
img = Image.open('image.png').convert('LA')
img.save('greyscale.png')

Using matplotlib and the formula

Y' = 0.2989 R + 0.5870 G + 0.1140 B 

you could do:

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as mpimg

def rgb2gray(rgb):
    return np.dot(rgb[...,:3], [0.2989, 0.5870, 0.1140])

img = mpimg.imread('image.png')     
gray = rgb2gray(img)    
plt.imshow(gray, cmap=plt.get_cmap('gray'), vmin=0, vmax=1)
plt.show()

Mocking HttpClient in unit tests

This is an old question, but I feel the urge to extend the answers with a solution I didn't see here.
You can fake the Microsoft assemly (System.Net.Http) and then use ShinsContext during the test.

  1. In VS 2017, right click on the System.Net.Http assembly and choose "Add Fakes Assembly"
  2. Put your code in the unit test method under a ShimsContext.Create() using. This way, you can isolate the code where you are planning to fake the HttpClient.
  3. Depends on your implementation and test, I would suggest to implement all the desired acting where you call a method on the HttpClient and want to fake the returned value. Using ShimHttpClient.AllInstances will fake your implementation in all the instances created during your test. For example, if you want to fake the GetAsync() method, do the following:

    [TestMethod]
    public void FakeHttpClient()
    {
        using (ShimsContext.Create())
        {
            System.Net.Http.Fakes.ShimHttpClient.AllInstances.GetAsyncString = (c, requestUri) =>
            {
              //Return a service unavailable response
              var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.ServiceUnavailable);
              var task = Task.FromResult(httpResponseMessage);
              return task;
            };
    
            //your implementation will use the fake method(s) automatically
            var client = new Connection(_httpClient);
            client.doSomething(); 
        }
    }
    

Can we locate a user via user's phone number in Android?

The answer is: you can't only through sms, i have tried that approach before.

You could fetch the base station IDs, but this won't help you a lot without the location of the base station itself and this informations are really hard to retrieve from the providers.

I have looked through the 3 apps you have listed in your question:

  1. The App uses WiFi and GPRS location service, quite the same approach as Google uses on the phone. phonesavvy maybe has a base station location database or uses a database retrieved e.g. from OpenStreetMap or some similar crowd-based project.
  2. The app analyzes just the number for country code and city code. No location there.
  3. Dito.

URL encoding in Android

I'm going to add one suggestion here. You can do this which avoids having to get any external libraries.

Give this a try:

String urlStr = "http://abc.dev.domain.com/0007AC/ads/800x480 15sec h.264.mp4";
URL url = new URL(urlStr);
URI uri = new URI(url.getProtocol(), url.getUserInfo(), url.getHost(), url.getPort(), url.getPath(), url.getQuery(), url.getRef());
url = uri.toURL();

You can see that in this particular URL, I need to have those spaces encoded so that I can use it for a request.

This takes advantage of a couple features available to you in Android classes. First, the URL class can break a url into its proper components so there is no need for you to do any string search/replace work. Secondly, this approach takes advantage of the URI class feature of properly escaping components when you construct a URI via components rather than from a single string.

The beauty of this approach is that you can take any valid url string and have it work without needing any special knowledge of it yourself.

C# difference between == and Equals()

I would add that if you cast your object to a string then it will work correctly. This is why the compiler will give you a warning saying:

Possible unintended reference comparison; to get a value comparison, cast the left hand side to type 'string'

How to use DISTINCT and ORDER BY in same SELECT statement?

Just use this code, If you want values of [Category] and [CreationDate] columns

SELECT [Category], MAX([CreationDate]) FROM [MonitoringJob] 
             GROUP BY [Category] ORDER BY MAX([CreationDate]) DESC

Or use this code, If you want only values of [Category] column.

SELECT [Category] FROM [MonitoringJob] 
GROUP BY [Category] ORDER BY MAX([CreationDate]) DESC

You'll have all the distinct records what ever you want.

Why does this AttributeError in python occur?

Because you imported scipy, not sparse. Try from scipy import sparse?

Change the image source on rollover using jQuery

If the solution you are looking for is for an animated button, then the best you can do to improve in performance is the combination of sprites and CSS. A sprite is a huge image that contains all the images from your site (header, logo, buttons, and all decorations you have). Each image you have uses an HTTP request, and the more HTTP requests the more time it will take to load.

.buttonClass {
    width: 25px;
    height: 25px;
    background: url(Sprite.gif) -40px -500px;
}
.buttonClass:hover {
    width: 25px;
    height: 25px;
    background: url(Sprite.gif) -40px -525px;
}

The 0px 0px coordinates will be the left upper corner from your sprites.

But if you are developing some photo album with Ajax or something like that, then JavaScript (or any framework) is the best.

Have fun!

How to run a script file remotely using SSH

Backticks will run the command on the local shell and put the results on the command line. What you're saying is 'execute ./test/foo.sh and then pass the output as if I'd typed it on the commandline here'.

Try the following command, and make sure that thats the path from your home directory on the remote computer to your script.

ssh kev@server1 './test/foo.sh'

Also, the script has to be on the remote computer. What this does is essentially log you into the remote computer with the listed command as your shell. You can't run a local script on a remote computer like this (unless theres some fun trick I don't know).

Index inside map() function

Using Ramda:

import {addIndex, map} from 'ramda';

const list = [ 'h', 'e', 'l', 'l', 'o'];
const mapIndexed = addIndex(map);
mapIndexed((currElement, index) => {
  console.log("The current iteration is: " + index);
  console.log("The current element is: " + currElement);
  console.log("\n");
  return 'X';
}, list);

Python Serial: How to use the read or readline function to read more than 1 character at a time

I was reciving some date from my arduino uno (0-1023 numbers). Using code from 1337holiday, jwygralak67 and some tips from other sources:

import serial
import time

ser = serial.Serial(
    port='COM4',\
    baudrate=9600,\
    parity=serial.PARITY_NONE,\
    stopbits=serial.STOPBITS_ONE,\
    bytesize=serial.EIGHTBITS,\
        timeout=0)

print("connected to: " + ser.portstr)

#this will store the line
seq = []
count = 1

while True:
    for c in ser.read():
        seq.append(chr(c)) #convert from ANSII
        joined_seq = ''.join(str(v) for v in seq) #Make a string from array

        if chr(c) == '\n':
            print("Line " + str(count) + ': ' + joined_seq)
            seq = []
            count += 1
            break


ser.close()

How to multiply values using SQL

Why are you grouping by? Do you mean order by?

SELECT player_name, player_salary, player_salary * 1.1 AS NewSalary
FROM players
ORDER BY player_salary, player_name;

How to left align a fixed width string?

You can prefix the size requirement with - to left-justify:

sys.stdout.write("%-6s %-50s %-25s\n" % (code, name, industry))

Unable to execute dex: Multiple dex files define

I found below solution in eclipse...hope it works for you :)

Right click on the Project Name

Select Java Build Path, go to the tab Order and Export

Unchecked your .jar library's

push() a two-dimensional array

The solution below uses a double loop to add data to the bottom of a 2x2 array in the Case 3. The inner loop pushes selected elements' values into a new row array. The outerloop then pushes the new row array to the bottom of an existing array (see Newbie: Add values to two-dimensional array with for loops, Google Apps Script).

In this example, I created a function that extracts a section from an existing array. The extracted section can be a row (full or partial), a column (full or partial), or a 2x2 section of the existing array. A new blank array (newArr) is filled by pushing the relevant section from the existing array (arr) into the new array.

 function arraySection(arr, r1, c1, rLength, cLength) {      
   rowMax = arr.length;
    if(isNaN(rowMax)){rowMax = 1};
   colMax = arr[0].length;
   if(isNaN(colMax)){colMax = 1};
   var r2 = r1 + rLength - 1;
   var c2 = c1 + cLength - 1;

   if ((r1< 0 || r1 > r2 || r1 > rowMax || (r1 | 0) != r1) || (r2 < 0 || 
     r2 > rowMax || (r2 | 0) != r2)|| (c1< 0 || c1 > c2 || c1 > colMax || 
   (c1 | 0) != c1) ||(c2 < 0 || c2 > colMax || (c2 | 0) != c2)){
        throw new Error(
        'arraySection: invalid input')       
        return;
     };
   var newArr = [];

// Case 1: extracted section is a column array, 
//          all elements are in the same column
 if (c1 == c2){
   for (var i = r1; i <= r2; i++){ 
         // Logger.log("arr[i][c1] for i = " + i);
         // Logger.log(arr[i][c1]);
     newArr.push([arr[i][c1]]); 
     };
    };  

// Case 2: extracted section is a row array, 
//          all elements are in the same row
  if (r1 == r2 && c1 != c2){
    for (var j = c1; j <= c2; j++){ 
      newArr.push(arr[r1][j]); 
      };
   };  

// Case 3: extracted section is a 2x2 section 
    if (r1 != r2 && c1 != c2){     
     for (var i = r1; i <= r2; i++) {
          rowi = [];
       for (var j = c1; j <= c2; j++) {
          rowi.push(arr[i][j]);
        }
       newArr.push(rowi)
      };
    };
   return(newArr);
  };

Git merge master into feature branch

In Eclipse -

1)Checkout master branch

Git Repositories ->Click on your repository -> click on Local ->double click master branch
->Click on yes for check out

2)Pull master branch

Right click on project ->click on Team -> Click on Pull

3)Checkout your feature branch(follow same steps mentioned in 1 point)

4)Merge master into feature

Git Repositories ->Click on your repository -> click on Local ->Right Click on your selected feature branch ->Click on merge ->Click on Local ->Click on Master ->Click on Merge.

5)Now you will get all changes of Master branch in feature branch. Remove conflict if any.

For conflict if any exists ,follow this -
Changes mentioned as Head(<<<<<< HEAD) is your change, Changes mentioned in branch(>>>>>>> branch) is other person change, you can update file accordingly.

Note - You need to do add to index for conflicts files

6)commit and push your changes in feature branch.

Right click on project ->click on Team -> Click on commit -> Commit and Push.

OR

Git Repositories ->Click on your repository -> click on Local ->Right Click on your selected feature branch ->Click on Push Branch ->Preview ->Push

remote: repository not found fatal: not found

Also, be sure, that two-factor authentication is off, otherwise use personal access tokens

Details here : Can I use GitHub's 2-Factor Authentication with TortoiseGit?

Update all objects in a collection using LINQ

Suppose we have data like below,

var items = new List<string>({"123", "456", "789"});
// Like 123 value get updated to 123ABC ..

and if we want to modify the list and replace the existing values of the list to modified values, then first create a new empty list, then loop through data list by invoking modifying method on each list item,

var modifiedItemsList = new List<string>();

items.ForEach(i => {
  var modifiedValue = ModifyingMethod(i);
  modifiedItemsList.Add(items.AsEnumerable().Where(w => w == i).Select(x => modifiedValue).ToList().FirstOrDefault()?.ToString()) 
});
// assign back the modified list
items = modifiedItemsList;

How to Make Laravel Eloquent "IN" Query?

If you are using Query builder then you may use a blow

DB::table(Newsletter Subscription)
->select('*')
->whereIn('id', $send_users_list)
->get()

If you are working with Eloquent then you can use as below

$sendUsersList = Newsletter Subscription:: select ('*')
                ->whereIn('id', $send_users_list)
                ->get();

Where does Chrome store extensions?

For older versions of windows (2k, 2k3, xp)

"%Userprofile%\Local Settings\Application Data\Google\Chrome\User Data\Default\Extensions" 

What is the 'instanceof' operator used for in Java?

You could use Map to make higher abstraction on instance of

private final Map<Class, Consumer<String>> actions = new HashMap<>();

Then having such map add some action to it:

actions.put(String.class, new Consumer<String>() {
        @Override
        public void accept(String s) {
           System.out.println("action for String");       
        }
    };

Then having an Object of not known type you could get specific action from that map:

actions.get(someObject).accept(someObject)

Laravel 5 – Clear Cache in Shared Hosting Server

You can do this if you are using Lumen from Laravel on your routes/web.php file:

use Illuminate\Support\Facades\Artisan;

$app->get('/clear-cache', function () {
    $code = Artisan::call('cache:clear');
    return 'cache cleared';
});

how to parse xml to java object?

JAXB is a reliable choice as it does xml to java classes mapping smoothely. But there are other frameworks available, here is one such:

https://code.google.com/p/xmappr/

PHP class not found but it's included

As a more systematic and structured solution you could define folders where your classes are stored and create an autoloader (__autoload()) which will search the class files in defined places:

require_once("../settings.php");
define('DIR_CLASSES', '/path/to/the/classes/folder/'); // this can be inside your settings.php

$user = new User();
$user->createUser($_POST["username"], $_POST["email"], $_POST["password"]);

function __autoload($classname) { 
    if(file_exists(DIR_CLASSES . 'class' . $classname . '.php')) {
        include_once(DIR_CLASSES . 'class' . $classname . '.php'); // looking for the class in the project's classes folder
    } else {
        include_once($classname . '.php'); // looking for the class in include_path
    }
} 

The difference between the 'Local System' account and the 'Network Service' account?

Since there is so much confusion about functionality of standard service accounts, I'll try to give a quick run down.

First the actual accounts:

  • LocalService account (preferred)

    A limited service account that is very similar to Network Service and meant to run standard least-privileged services. However, unlike Network Service it accesses the network as an Anonymous user.

    • Name: NT AUTHORITY\LocalService
    • the account has no password (any password information you provide is ignored)
    • HKCU represents the LocalService user account
    • has minimal privileges on the local computer
    • presents anonymous credentials on the network
    • SID: S-1-5-19
    • has its own profile under the HKEY_USERS registry key (HKEY_USERS\S-1-5-19)

     

  • NetworkService account

    Limited service account that is meant to run standard privileged services. This account is far more limited than Local System (or even Administrator) but still has the right to access the network as the machine (see caveat above).

    • NT AUTHORITY\NetworkService
    • the account has no password (any password information you provide is ignored)
    • HKCU represents the NetworkService user account
    • has minimal privileges on the local computer
    • presents the computer's credentials (e.g. MANGO$) to remote servers
    • SID: S-1-5-20
    • has its own profile under the HKEY_USERS registry key (HKEY_USERS\S-1-5-20)
    • If trying to schedule a task using it, enter NETWORK SERVICE into the Select User or Group dialog

     

  • LocalSystem account (dangerous, don't use!)

    Completely trusted account, more so than the administrator account. There is nothing on a single box that this account cannot do, and it has the right to access the network as the machine (this requires Active Directory and granting the machine account permissions to something)

    • Name: .\LocalSystem (can also use LocalSystem or ComputerName\LocalSystem)
    • the account has no password (any password information you provide is ignored)
    • SID: S-1-5-18
    • does not have any profile of its own (HKCU represents the default user)
    • has extensive privileges on the local computer
    • presents the computer's credentials (e.g. MANGO$) to remote servers

     

Above when talking about accessing the network, this refers solely to SPNEGO (Negotiate), NTLM and Kerberos and not to any other authentication mechanism. For example, processing running as LocalService can still access the internet.

The general issue with running as a standard out of the box account is that if you modify any of the default permissions you're expanding the set of things everything running as that account can do. So if you grant DBO to a database, not only can your service running as Local Service or Network Service access that database but everything else running as those accounts can too. If every developer does this the computer will have a service account that has permissions to do practically anything (more specifically the superset of all of the different additional privileges granted to that account).

It is always preferable from a security perspective to run as your own service account that has precisely the permissions you need to do what your service does and nothing else. However, the cost of this approach is setting up your service account, and managing the password. It's a balancing act that each application needs to manage.

In your specific case, the issue that you are probably seeing is that the the DCOM or COM+ activation is limited to a given set of accounts. In Windows XP SP2, Windows Server 2003, and above the Activation permission was restricted significantly. You should use the Component Services MMC snapin to examine your specific COM object and see the activation permissions. If you're not accessing anything on the network as the machine account you should seriously consider using Local Service (not Local System which is basically the operating system).


In Windows Server 2003 you cannot run a scheduled task as

  • NT_AUTHORITY\LocalService (aka the Local Service account), or
  • NT AUTHORITY\NetworkService (aka the Network Service account).

That capability only was added with Task Scheduler 2.0, which only exists in Windows Vista/Windows Server 2008 and newer.

A service running as NetworkService presents the machine credentials on the network. This means that if your computer was called mango, it would present as the machine account MANGO$:

enter image description here

AngularJS open modal on button click

You should take a look at Batarang for AngularJS debugging

As for your issue:

Your scope variable is not directly attached to the modal correctly. Below is the adjusted code. You need to specify when the modal shows using ng-show

<!-- Confirmation Dialog -->
<div class="modal" modal="showModal" ng-show="showModal">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
        <h4 class="modal-title">Delete confirmation</h4>
      </div>
      <div class="modal-body">
        <p>Are you sure?</p>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal" ng-click="cancel()">No</button>
        <button type="button" class="btn btn-primary" ng-click="ok()">Yes</button>
      </div>
    </div>
  </div>
</div>
<!-- End of Confirmation Dialog -->

Searching for UUIDs in text with regex

If you want to check or validate a specific UUID version, here are the corresponding regexes.

Note that the only difference is the version number, which is explained in 4.1.3. Version chapter of UUID 4122 RFC.

The version number is the first character of the third group : [VERSION_NUMBER][0-9A-F]{3} :

  • UUID v1 :

    /^[0-9A-F]{8}-[0-9A-F]{4}-[1][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i
    
  • UUID v2 :

    /^[0-9A-F]{8}-[0-9A-F]{4}-[2][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i
    
  • UUID v3 :

    /^[0-9A-F]{8}-[0-9A-F]{4}-[3][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i
    
  • UUID v4 :

    /^[0-9A-F]{8}-[0-9A-F]{4}-[4][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i
    
  • UUID v5 :

    /^[0-9A-F]{8}-[0-9A-F]{4}-[5][0-9A-F]{3}-[89AB][0-9A-F]{3}-[0-9A-F]{12}$/i
    

Common Header / Footer with static HTML

No. Static HTML files don't change. You could potentially do this with some fancy Javascript AJAXy solution but that would be bad.

Best way to get identity of inserted row?

Add

SELECT CAST(scope_identity() AS int);

to the end of your insert sql statement, then

NewId = command.ExecuteScalar()

will retrieve it.

Get next / previous element using JavaScript?

This will be easy... its an pure javascript code

    <script>
           alert(document.getElementById("someElement").previousElementSibling.innerHTML);
    </script>

How to switch from the default ConstraintLayout to RelativeLayout in Android Studio

just do it: in component tree right click on ConstraintLayout and select relativelayout on convert view...

Vue.js get selected option on @change

You can also use v-model for the rescue

<template>
    <select name="LeaveType" v-model="leaveType" @change="onChange()" class="form-control">
         <option value="1">Annual Leave/ Off-Day</option>
         <option value="2">On Demand Leave</option>
    </select>
</template>

<script>
export default {
    data() {
        return {
            leaveType: '',
        }
    },

    methods: {
        onChange() {
            console.log('The new value is: ', this.leaveType)
        }
    }
}
</script>

How do I get a background location update every n minutes in my iOS application?

I found a solution to implement this with the help of the Apple Developer Forums:

  • Specify location background mode
  • Create an NSTimer in the background with UIApplication:beginBackgroundTaskWithExpirationHandler:
  • When n is smaller than UIApplication:backgroundTimeRemaining it will work just fine. When n is larger, the location manager should be enabled (and disabled) again before there is no time remaining to avoid the background task being killed.

This works because location is one of the three allowed types of background execution.

Note: I lost some time by testing this in the simulator where it doesn't work. However, it works fine on my phone.

How to test if a list contains another list?

a=[[1,2] , [3,4] , [0,5,4]]
print(a.__contains__([0,5,4]))

It provides true output.

a=[[1,2] , [3,4] , [0,5,4]]
print(a.__contains__([1,3]))

It provides false output.

How to create an array containing 1...N

for me this is more useful utility:

/**
 * create an array filled with integer numbers from base to length
 * @param {number} from
 * @param {number} to
 * @param {number} increment
 * @param {Array} exclude
 * @return {Array}
 */
export const count = (from = 0, to = 1, increment = 1, exclude = []) => {
  const array = [];
  for (let i = from; i <= to; i += increment) !exclude.includes(i) && array.push(i);
  return array;
};

.map() a Javascript ES6 Map?

You can use myMap.forEach, and in each loop, using map.set to change value.

_x000D_
_x000D_
myMap = new Map([_x000D_
  ["a", 1],_x000D_
  ["b", 2],_x000D_
  ["c", 3]_x000D_
]);_x000D_
_x000D_
for (var [key, value] of myMap.entries()) {_x000D_
  console.log(key + ' = ' + value);_x000D_
}_x000D_
_x000D_
_x000D_
myMap.forEach((value, key, map) => {_x000D_
  map.set(key, value+1)_x000D_
})_x000D_
_x000D_
for (var [key, value] of myMap.entries()) {_x000D_
  console.log(key + ' = ' + value);_x000D_
}
_x000D_
_x000D_
_x000D_

“Origin null is not allowed by Access-Control-Allow-Origin” error for request made by application running from a file:// URL

If you are doing local testing or calling the file from something like file:// then you need to disable browser security.

On MAC: open -a Google\ Chrome --args --disable-web-security

ZIP Code (US Postal Code) validation

function isValidUSZip(sZip) {
   return /^\d{5}(-\d{4})?$/.test(sZip);
}

How to replace url parameter with javascript/jquery?

Here is function which replaces url param with paramVal

function updateURLParameter(url, param, paramVal){
        if(!url.includes('?')){
            return url += '?' + param + '=' + paramVal;
        }else if(!url.includes(param)){
            return url += '&' + param + '=' + paramVal;
        }else {
            let paramStartIndex = url.search(param);
            let paramEndIndex = url.indexOf('&', paramStartIndex);
            if (paramEndIndex == -1){
                paramEndIndex = url.length;
            }
            let brands = url.substring(paramStartIndex, paramEndIndex);
    
            return url.replace(brands, param + '=' + paramVal);
        }
    }

6 digits regular expression

You can use range quantifier {min,max} to specify minimum of 1 digit and maximum of 6 digits as:

^[0-9]{1,6}$

Explanation:

^     : Start anchor
[0-9] : Character class to match one of the 10 digits
{1,6} : Range quantifier. Minimum 1 repetition and maximum 6.
$     : End anchor

Why did your regex not work ?

You were almost close on the regex:

^[0-9][0-9]\?[0-9]\?[0-9]\?[0-9]\?[0-9]\?$

Since you had escaped the ? by preceding it with the \, the ? was no more acting as a regex meta-character ( for 0 or 1 repetitions) but was being treated literally.

To fix it just remove the \ and you are there.

See it on rubular.

The quantifier based regex is shorter, more readable and can easily be extended to any number of digits.

Your second regex:

^[0-999999]$

is equivalent to:

^[0-9]$

which matches strings with exactly one digit. They are equivalent because a character class [aaaab] is same as [ab].

How to restrict SSH users to a predefined set of commands after login?

You can also restrict keys to permissible commands (in the authorized_keys file).

I.e. the user would not log in via ssh and then have a restricted set of commands but rather would only be allowed to execute those commands via ssh (e.g. "ssh somehost bin/showlogfile")

jQuery checkbox check/uncheck

 $('mainCheckBox').click(function(){
    if($(this).prop('checked')){
        $('Id or Class of checkbox').prop('checked', true);
    }else{
        $('Id or Class of checkbox').prop('checked', false);
    }
});

Soft Edges using CSS?

Another option is to use one of my personal favorite CSS tools: box-shadow.

A box shadow is really a drop-shadow on the node. It looks like this:

-moz-box-shadow: 1px 2px 3px rgba(0,0,0,.5);
-webkit-box-shadow: 1px 2px 3px rgba(0,0,0,.5);
box-shadow: 1px 2px 3px rgba(0,0,0,.5);

The arguments are:

1px: Horizontal offset of the effect. Positive numbers shift it right, negative left.
2px: Vertical offset of the effect. Positive numbers shift it down, negative up.
3px: The blur effect.  0 means no blur.
color: The color of the shadow.

So, you could leave your current design, and add a box-shadow like:

box-shadow: 0px -2px 2px rgba(34,34,34,0.6);

This should give you a 'blurry' top-edge.

This website will help with more information: http://css-tricks.com/snippets/css/css-box-shadow/

Reordering Chart Data Series

This function gets the series names, puts them into an array, sorts the array and based on that defines the plotting order which will give the desired output.

Function Increasing_Legend_Sort(mychart As Chart)


    Dim Arr()
    ReDim Arr(1 To mychart.FullSeriesCollection.Count)

        'Assigning Series names to an array
        For i = LBound(Arr) To UBound(Arr)
        Arr(i) = mychart.FullSeriesCollection(i).Name
        Next i

        'Bubble-Sort (Sort the array in increasing order)
        For r1 = LBound(Arr) To UBound(Arr)
            rval = Arr(r1)
                For r2 = LBound(Arr) To UBound(Arr)
                    If Arr(r2) > rval Then 'Change ">" to "<" to make it decreasing
                        Arr(r1) = Arr(r2)
                        Arr(r2) = rval
                        rval = Arr(r1)
                    End If
                Next r2
        Next r1

    'Defining the PlotOrder
    For i = LBound(Arr) To UBound(Arr)
    mychart.FullSeriesCollection(Arr(i)).PlotOrder = i
    Next i

End Function

Best way to encode text data for XML

Depending on how much you know about the input, you may have to take into account that not all Unicode characters are valid XML characters.

Both Server.HtmlEncode and System.Security.SecurityElement.Escape seem to ignore illegal XML characters, while System.XML.XmlWriter.WriteString throws an ArgumentException when it encounters illegal characters (unless you disable that check in which case it ignores them). An overview of library functions is available here.

Edit 2011/8/14: seeing that at least a few people have consulted this answer in the last couple years, I decided to completely rewrite the original code, which had numerous issues, including horribly mishandling UTF-16.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

/// <summary>
/// Encodes data so that it can be safely embedded as text in XML documents.
/// </summary>
public class XmlTextEncoder : TextReader {
    public static string Encode(string s) {
        using (var stream = new StringReader(s))
        using (var encoder = new XmlTextEncoder(stream)) {
            return encoder.ReadToEnd();
        }
    }

    /// <param name="source">The data to be encoded in UTF-16 format.</param>
    /// <param name="filterIllegalChars">It is illegal to encode certain
    /// characters in XML. If true, silently omit these characters from the
    /// output; if false, throw an error when encountered.</param>
    public XmlTextEncoder(TextReader source, bool filterIllegalChars=true) {
        _source = source;
        _filterIllegalChars = filterIllegalChars;
    }

    readonly Queue<char> _buf = new Queue<char>();
    readonly bool _filterIllegalChars;
    readonly TextReader _source;

    public override int Peek() {
        PopulateBuffer();
        if (_buf.Count == 0) return -1;
        return _buf.Peek();
    }

    public override int Read() {
        PopulateBuffer();
        if (_buf.Count == 0) return -1;
        return _buf.Dequeue();
    }

    void PopulateBuffer() {
        const int endSentinel = -1;
        while (_buf.Count == 0 && _source.Peek() != endSentinel) {
            // Strings in .NET are assumed to be UTF-16 encoded [1].
            var c = (char) _source.Read();
            if (Entities.ContainsKey(c)) {
                // Encode all entities defined in the XML spec [2].
                foreach (var i in Entities[c]) _buf.Enqueue(i);
            } else if (!(0x0 <= c && c <= 0x8) &&
                       !new[] { 0xB, 0xC }.Contains(c) &&
                       !(0xE <= c && c <= 0x1F) &&
                       !(0x7F <= c && c <= 0x84) &&
                       !(0x86 <= c && c <= 0x9F) &&
                       !(0xD800 <= c && c <= 0xDFFF) &&
                       !new[] { 0xFFFE, 0xFFFF }.Contains(c)) {
                // Allow if the Unicode codepoint is legal in XML [3].
                _buf.Enqueue(c);
            } else if (char.IsHighSurrogate(c) &&
                       _source.Peek() != endSentinel &&
                       char.IsLowSurrogate((char) _source.Peek())) {
                // Allow well-formed surrogate pairs [1].
                _buf.Enqueue(c);
                _buf.Enqueue((char) _source.Read());
            } else if (!_filterIllegalChars) {
                // Note that we cannot encode illegal characters as entity
                // references due to the "Legal Character" constraint of
                // XML [4]. Nor are they allowed in CDATA sections [5].
                throw new ArgumentException(
                    String.Format("Illegal character: '{0:X}'", (int) c));
            }
        }
    }

    static readonly Dictionary<char,string> Entities =
        new Dictionary<char,string> {
            { '"', "&quot;" }, { '&', "&amp;"}, { '\'', "&apos;" },
            { '<', "&lt;" }, { '>', "&gt;" },
        };

    // References:
    // [1] http://en.wikipedia.org/wiki/UTF-16/UCS-2
    // [2] http://www.w3.org/TR/xml11/#sec-predefined-ent
    // [3] http://www.w3.org/TR/xml11/#charsets
    // [4] http://www.w3.org/TR/xml11/#sec-references
    // [5] http://www.w3.org/TR/xml11/#sec-cdata-sect
}

Unit tests and full code can be found here.

How to revert a "git rm -r ."?

Update:

Since git rm . deletes all files in this and child directories in the working checkout as well as in the index, you need to undo each of these changes:

git reset HEAD . # This undoes the index changes
git checkout .   # This checks out files in this and child directories from the HEAD

This should do what you want. It does not affect parent folders of your checked-out code or index.


Old answer that wasn't:

reset HEAD

will do the trick, and will not erase any uncommitted changes you have made to your files.

after that you need to repeat any git add commands you had queued up.

Launch a shell command with in a python script, wait for the termination and return to the script

this worked for me fine!

shell_command = "ls -l" subprocess.call(shell_command.split())

Losing Session State

You could add some logging to the Global.asax in Session_Start and Application_Start to track what's going on with the user's Session and the Application as a whole.

Also, watch out of you're running in Web Farm mode (multiple IIS threads defined in the application pool) or load balancing because the user can end up hitting a different server that does not have the same memory. If this is the case, you can switch the Session mode to SQL Server.

ng-repeat :filter by single field

If you want filter for one field:

label>Any: <input ng-model="search.color"></label> <br>
<tr ng-repeat="friendObj in friends | filter:search:strict">

If you want filter for all field:

 label>Any: <input ng-model="search.$"></label> <br>
 <tr ng-repeat="friendObj in friends | filter:search:strict">

and https://docs.angularjs.org/api/ng/filter/filter good for you

Confusing "duplicate identifier" Typescript error message

I had this problem and it turns out I had a a second node_modules folder in my project that wasn't supposed to be there :-(

Should a RESTful 'PUT' operation return something

The HTTP/1.1 spec (section 9.6) discusses the appropriate response/error codes. However it doesn't address the response content.

What would you expect ? A simple HTTP response code (200 etc.) seems straightforward and unambiguous to me.

How to do select from where x is equal to multiple values?

You can try using parentheses around the OR expressions to make sure your query is interpreted correctly, or more concisely, use IN:

SELECT ads.*, location.county 
FROM ads
LEFT JOIN location ON location.county = ads.county_id
WHERE ads.published = 1 
AND ads.type = 13
AND ads.county_id IN (2,5,7,9)

Create a temporary table in MySQL with an index from a select

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
[(create_definition,...)]
[table_options]
select_statement

Example :

CREATE TEMPORARY TABLE IF NOT EXISTS mytable
(id int(11) NOT NULL, PRIMARY KEY (id)) ENGINE=MyISAM;
INSERT IGNORE INTO mytable SELECT id FROM table WHERE xyz;

Best Practice: Initialize JUnit class fields in setUp() or at declaration?

Since each test is executed independently, with a fresh instance of the object, there's not much point to the Test object having any internal state except that shared between setUp() and an individual test and tearDown(). This is one reason (in addition to the reasons others gave) that it's good to use the setUp() method.

Note: It's a bad idea for a JUnit test object to maintain static state! If you make use of static variable in your tests for anything other than tracking or diagnostic purposes, you are invalidating part of the purpose of JUnit, which is that the tests can (an may) be run in any order, each test running with a fresh, clean state.

The advantages to using setUp() is that you don't have to cut-and-paste initialization code in every test method and that you don't have test setup code in the constructor. In your case, there is little difference. Just creating an empty list can be done safely as you show it or in the constructor as it's a trivial initialization. However, as you and others have pointed out, anything that can possibly throw an Exception should be done in setUp() so you get the diagnostic stack dump if it fails.

In your case, where you are just creating an empty list, I would do the same way you are suggesting: Assign the new list at the point of declaration. Especially because this way you have the option of marking it final if this makes sense for your test class.

What is the difference between 0.0.0.0, 127.0.0.1 and localhost?

In current version of Jekyll, it defaults to http://127.0.0.1:4000/.
This is good, if you are connected to a network but do not want anyone else to access your application.

However it may happen that you want to see how your application runs on a mobile or from some other laptop/computer.

In that case, you can use

jekyll serve --host 0.0.0.0

This binds your application to the host & next use following to connect to it from some other host

http://host's IP adress/4000 

Send response to all clients except sender

broadcast.emit sends the msg to all other clients (except for the sender)

socket.on('cursor', function(data) {
  socket.broadcast.emit('msg', data);
});

Open S3 object as a string with Boto3

This isn't in the boto3 documentation. This worked for me:

object.get()["Body"].read()

object being an s3 object: http://boto3.readthedocs.org/en/latest/reference/services/s3.html#object

What's the fastest algorithm for sorting a linked list?

This is a nice little paper on this topic. His empirical conclusion is that Treesort is best, followed by Quicksort and Mergesort. Sediment sort, bubble sort, selection sort perform very badly.

A COMPARATIVE STUDY OF LINKED LIST SORTING ALGORITHMS by Ching-Kuang Shene

http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.31.9981

Vue.js—Difference between v-model and v-bind

v-model
it is two way data binding, it is used to bind html input element when you change input value then bounded data will be change.

v-model is used only for HTML input elements

ex: <input type="text" v-model="name" > 

v-bind
it is one way data binding,means you can only bind data to input element but can't change bounded data changing input element. v-bind is used to bind html attribute
ex:
<input type="text" v-bind:class="abc" v-bind:value="">

<a v-bind:href="home/abc" > click me </a>

Better way to get type of a Javascript variable?

typeof condition is used to check variable type, if you are check variable type in if-else condition e.g.

if(typeof Varaible_Name "undefined")
{

}

C/C++ switch case with string

Just use a if() { } else if () { } chain. Using a hash value is going to be a maintenance nightmare. switch is intended to be a low-level statement which would not be appropriate for string comparisons.

java.lang.ClassNotFoundException: org.apache.log4j.Level

You also need to include the Log4J JAR file in the classpath.

Note that slf4j-log4j12-1.6.4.jar is only an adapter to make it possible to use Log4J via the SLF4J API. It does not contain the actual implementation of Log4J.

Regex to get the words after matching string

But I need the match result to be ... not in a match group...

For what you are trying to do, this should work. \K resets the starting point of the match.

\bObject Name:\s+\K\S+

You can do the same for getting your Security ID matches.

\bSecurity ID:\s+\K\S+

Bootstrap Dropdown with Hover

The easiest solution would be in CSS. Add something like...

.dropdown:hover .dropdown-menu {
    display: block;
    margin-top: 0; // remove the gap so it doesn't close
 }

Working Fiddle

How do I convert a float to an int in Objective C?

what's wrong with:

int myInt = myFloat;

bear in mind this'll use the default rounding rule, which is towards zero (i.e. -3.9f becomes -3)

How to convert 2D float numpy array to 2D int numpy array?

If you're not sure your input is going to be a Numpy array, you can use asarray with dtype=int instead of astype:

>>> np.asarray([1,2,3,4], dtype=int)
array([1, 2, 3, 4])

If the input array already has the correct dtype, asarray avoids the array copy while astype does not (unless you specify copy=False):

>>> a = np.array([1,2,3,4])
>>> a is np.asarray(a)  # no copy :)
True
>>> a is a.astype(int)  # copy :(
False
>>> a is a.astype(int, copy=False)  # no copy :)
True

Rename all files in a folder with a prefix in a single command

Also works for items with spaces and ignores directories

for f in *; do [[ -f "$f" ]] && mv "$f" "unix_$f"; done

How do you round a double in Dart to a given degree of precision AFTER the decimal point?

You can use toStringAsFixed in order to display the limited digits after decimal points. toStringAsFixed returns a decimal-point string-representation. toStringAsFixed accepts an argument called fraction Digits which is how many digits after decimal we want to display. Here is how to use it.

double pi = 3.1415926;
const val = pi.toStringAsFixed(2); // 3.14

How to "select distinct" across multiple data frame columns in pandas?

There is no unique method for a df, if the number of unique values for each column were the same then the following would work: df.apply(pd.Series.unique) but if not then you will get an error. Another approach would be to store the values in a dict which is keyed on the column name:

In [111]:
df = pd.DataFrame({'a':[0,1,2,2,4], 'b':[1,1,1,2,2]})
d={}
for col in df:
    d[col] = df[col].unique()
d

Out[111]:
{'a': array([0, 1, 2, 4], dtype=int64), 'b': array([1, 2], dtype=int64)}

UPDATE with CASE and IN - Oracle

Use to_number to convert budgpost to a number:

when to_number(budgpost,99999) in (1001,1012,50055) THEN 'BP_GR_A' 

EDIT: Make sure there are enough 9's in to_number to match to largest budget post.

If there are non-numeric budget posts, you could filter them out with a where clause at then end of the query:

where regexp_like(budgpost, '^-?[[:digit:],.]+$')

Scanner method to get a char

sc.next().charat(0).........is the method of entering character by user based on the number entered at the run time

example: sc.next().charat(2)------------>>>>>>>>

JQuery, setTimeout not working

This accomplishes the same thing but is much simpler:

$(document).ready(function() {  
   $("#board").delay(1000).append(".");
});

You can chain a delay before almost any jQuery method.

How to import popper.js?

add popper**.js** as dependency instead of popper (only): see the difference in bold.

yarn add popper.js , instead of yarn add popper

it makes the difference.

and include the script according your needs:

as html or the library access as a dependency in SPA applications like react or angular

php $_POST array empty upon form submission

I could solve the problem using enctype="application/x-www-form-urlencoded" as the default is "text/plain". When you check in $DATA the seperator is a space for "text/plain" and a special character for the "urlencoded".

Kind regards Frank

PowerShell - Start-Process and Cmdline Switches

Unless the OP is using PowerShell Community Extensions which does provide a Start-Process cmdlet along with a bunch of others. If this the case then Glennular's solution works a treat since it matches the positional parameters of pscx\start-process : -path (position 1) -arguments (positon 2).

Retrieving the first digit of a number

This way might makes more sense if you don't want to use str methods

int first = 1;
for (int i = 10; i < number; i *= 10) {
    first = number / i;
}

How to create a template function within a class? (C++)

See here: Templates, template methods,Member Templates, Member Function Templates

class   Vector
{
  int     array[3];

  template <class TVECTOR2> 
  void  eqAdd(TVECTOR2 v2);
};

template <class TVECTOR2>
void    Vector::eqAdd(TVECTOR2 a2)
{
  for (int i(0); i < 3; ++i) array[i] += a2[i];
}

User Get-ADUser to list all properties and export to .csv

@AnsgarWiechers - it's not my experience that querying everything and then pruning the result is more efficient when you're doing a targeted search of known accounts. Although, yes, it is also more efficient to select just the properties you need to return.

The below examples are based on a domain in the range of 20,000 account objects.

measure-command {Get-ADUser -Filter '*' -Properties DisplayName,st }
...
Seconds           : 16
Milliseconds      : 208

measure-command {$userlist | get-aduser -Properties DisplayName,st}
...
Seconds           : 3
Milliseconds      : 496

In the second example, $userlist contains 368 account names (just strings, not pre-fetched account objects).

Note that if I include the where clause per your suggestion to prune to the actually desired results, it's even more expensive.

measure-command {Get-ADUser -Filter '*' -Properties DisplayName,st |where {$userlist -Contains $_.samaccountname } }
...
Seconds           : 17
Milliseconds      : 876

Indexed attributes seem to have similar performance (I tried just returning displayName).

Even if I return all user account properties in my set, it's more efficient. (Adding a select statement to the below brings it down by a half-second).

measure-command {$userlist | get-aduser -Properties *}
...
Seconds           : 12
Milliseconds      : 75

I can't find a good document that was written in ye olde days about AD queries to link to, but you're hitting every account in your search scope to return the properties. This discusses the basics of doing effective AD queries - scoping and filtering: https://msdn.microsoft.com/en-us/library/ms808539.aspx#efficientadapps_topic01

When your search scope is "*", you're still building a (big) list of the objects and iterating through each one. An LDAP search filter is always more efficient to build the list first (or a narrow search base, which is again building a smaller list to query).

How to print register values in GDB?

If you're trying to print a specific register in GDB, you have to omit the % sign. For example,

info registers eip

If your executable is 64 bit, the registers start with r. Starting them with e is not valid.

info registers rip

Those can be abbreviated to:

i r rip

How to show another window from mainwindow in QT

  1. Implement a slot in your QMainWindow where you will open your new Window,
  2. Place a widget on your QMainWindow,
  3. Connect a signal from this widget to a slot from the QMainWindow (for example: if the widget is a QPushButton connect the signal click() to the QMainWindow custom slot you have created).

Code example:

MainWindow.h

// ...
include "newwindow.h"
// ...
public slots:
   void openNewWindow();
// ...
private:
   NewWindow *mMyNewWindow;
// ...
}

MainWindow.cpp

// ...
   MainWindow::MainWindow()
   {
      // ...
      connect(mMyButton, SIGNAL(click()), this, SLOT(openNewWindow()));
      // ...
   }
// ...
void MainWindow::openNewWindow()
{
   mMyNewWindow = new NewWindow(); // Be sure to destroy your window somewhere
   mMyNewWindow->show();
   // ...
}

This is an example on how display a custom new window. There are a lot of ways to do this.

How to detect when WIFI Connection has been established in Android?

This code does not require permission at all. It is restricted only to Wi-Fi network connectivity state changes (any other network is not taken into account). The receiver is statically published in the AndroidManifest.xml file and does not need to be exported as it will be invoked by the system protected broadcast, NETWORK_STATE_CHANGED_ACTION, at every network connectivity state change.

AndroidManifest:

<receiver
    android:name=".WifiReceiver"
    android:enabled="true"
    android:exported="false">

    <intent-filter>
        <!--protected-broadcast: Special broadcast that only the system can send-->
        <!--Corresponds to: android.net.wifi.WifiManager.NETWORK_STATE_CHANGED_ACTION-->
        <action android:name="android.net.wifi.STATE_CHANGE" />
    </intent-filter>

</receiver>

BroadcastReceiver class:

public class WifiReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
/*
 Tested (I didn't test with the WPS "Wi-Fi Protected Setup" standard):
 In API15 (ICE_CREAM_SANDWICH) this method is called when the new Wi-Fi network state is:
 DISCONNECTED, OBTAINING_IPADDR, CONNECTED or SCANNING

 In API19 (KITKAT) this method is called when the new Wi-Fi network state is:
 DISCONNECTED (twice), OBTAINING_IPADDR, VERIFYING_POOR_LINK, CAPTIVE_PORTAL_CHECK
 or CONNECTED

 (Those states can be obtained as NetworkInfo.DetailedState objects by calling
 the NetworkInfo object method: "networkInfo.getDetailedState()")
*/
    /*
     * NetworkInfo object associated with the Wi-Fi network.
     * It won't be null when "android.net.wifi.STATE_CHANGE" action intent arrives.
     */
    NetworkInfo networkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);

    if (networkInfo != null && networkInfo.isConnected()) {
        // TODO: Place the work here, like retrieving the access point's SSID

        /*
         * WifiInfo object giving information about the access point we are connected to.
         * It shouldn't be null when the new Wi-Fi network state is CONNECTED, but it got
         * null sometimes when connecting to a "virtualized Wi-Fi router" in API15.
         */
        WifiInfo wifiInfo = intent.getParcelableExtra(WifiManager.EXTRA_WIFI_INFO);
        String ssid = wifiInfo.getSSID();
    }
}
}

Permissions:

None

Set the text in a span

Try it.. It will first look for anchor tag that contain span with class "ui-icon-circle-triangle-w", then it set the text of span to "<<".

$('a span.ui-icon-circle-triangle-w').text('<<');

dlib installation on Windows 10

As you can see many answers above, But i would like to post a quick solution which works for sure in Anaconda3. I haven't chosen Visual Studio as it consumes lot of memory.

Please follow the below steps.

Step 1:
Install windows cmake.msi and configure environment variable
Step 2:
Create a conda environment, and install cmake using the below command.
pip install cmake
Step 3:
conda install -c conda-forge dlib

Note you can find few other dlib packages, but the above one will works perfectly with this procedure.

dlib will be successfully installed.

How do I hide a menu item in the actionbar?

According to Android Developer Official site,OnCreateOptionMenu(Menu menu) is not recomended for changing menu items or icons, visibility..etc at Runtime.

After the system calls onCreateOptionsMenu(), it retains an instance of the Menu you populate and will not call onCreateOptionsMenu() again unless the menu is invalidated for some reason. However, you should use onCreateOptionsMenu() only to create the initial menu state and not to make changes during the activity lifecycle.

If you want to modify the options menu based on events that occur during the activity lifecycle, you can do so in the onPrepareOptionsMenu() method. This method passes you the Menu object as it currently exists so you can modify it, such as add, remove, or disable items. (Fragments also provide an onPrepareOptionsMenu() callback.) --AndroidDeveloper Official Site --

As Recomended You can use this onOptionsItemSelected(MenuItem item) method track user inputs.

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

    if (id == R.id.edit) {
        Intent intent = new Intent(this, ExampleActivity.class);
        intent.putExtra(BUNDLE_KEY, mConnection);
        startActivityForResult(intent, PICK_CHANGE_REQUEST);
        return true;
    } else if (id == R.id.delete) {
        showDialog(this);
        return true;
    }

    return super.onOptionsItemSelected(item);
}

If you need to change Menu Items at Run time, You can use onPrepareOptionsMenu(Menu menu) to change them

@Override
public boolean onPrepareOptionsMenu(Menu menu){

    if (Utils.checkNetworkStatus(ExampleActivity.this)) {
        menu.findItem(R.id.edit).setVisible(true);
        menu.findItem(R.id.delete).setVisible(true);
    }else {
        menu.findItem(R.id.edit).setVisible(false);
        menu.findItem(R.id.delete).setVisible(false);
    }
    return true;
} 

Add the loading screen in starting of the android application

If the application is not doing anything in that 10 seconds, this will form a bad design only to make the user wait for 10 seconds doing nothing.

If there is something going on in that, or if you wish to implement 10 seconds delay splash screen,Here is the Code :

ProgressDialog pd;
pd = ProgressDialog.show(this,"Please Wait...", "Loading Application..", false, true);
pd.setCanceledOnTouchOutside(false);
Thread t = new Thread()
{ 
      @Override
      public void run()
      {
                try
                {
                    sleep(10000)  //Delay of 10 seconds
                } 
        catch (Exception e) {}
        handler.sendEmptyMessage(0);
        }
} ;
t.start();

//Handles the thread result of the Backup being executed.
private Handler handler = new Handler()
{
    @Override
    public void handleMessage(Message msg) 
    {
        pd.dismiss();
        //Start the Next Activity here...

    }
};

How to create a fix size list in python?

Note also that when you used arrays in C++ you might have had somewhat different needs, which are solved in different ways in Python:

  1. You might have needed just a collection of items; Python lists deal with this usecase just perfectly.
  2. You might have needed a proper array of homogenous items. Python lists are not a good way to store arrays.

Python solves the need in arrays by NumPy, which, among other neat things, has a way to create an array of known size:

from numpy import *

l = zeros(10)

PHP Warning: Invalid argument supplied for foreach()

Because, on whatever line the error is occurring at (you didn't tell us which that is), you're passing something to foreach that is not an array.

Look at what you're passing into foreach, determine what it is (with var_export), find out why it's not an array... and fix it.

Basic, basic debugging.

Windows 7 SDK installation failure

I'm having the same error as this "Windows 7 SDK installation failure":

Enter image description here

After finding out, I've got the solution.

It may also happen that the SDK installation runs through with a "success" message at the end, but nothing was actually installed. The only way to really find out whether the SDK was installed is to check the respective directory. C:Files\Microsoft SDKs\Windows\v7.1 or C:Files (x 86) SDKs\Windows\v7.1. If the subdirectory "v 7.1" was created and has some content, the SDK was installed. The solution for this problem is the same as for the issue with the error message: Uninstall Microsoft Visual C++ 2010 Redistributable (see below).

Resolution: Uninstall Microsoft Visual C++ 2010 Redistributable installations prior to Windows SDK installation.

Before the installation, I had the following Microsoft Visual C++ 2010 Redistributable installations. Note that the x 64 version is updated.

  • Microsoft Visual C++ 2010 Redistributable x 64-Microsoft Corporation 10.0.40219 15.2 MB 10.0.40219
  • Microsoft Visual C++ 2010 Redistributable-x 86 10.0.30319 Microsoft Corporation 11.0 MB 10.0.30319

Mapping two integers to one, in a unique and deterministic way

let us have two number B and C , encoding them into single number A

A = B + C * N

where

B=A % N = B

C=A / N = C

Disable sorting for a particular column in jQuery DataTables

Here is the answer !

targets is the column number, it starts from 0

$('#example').dataTable( {
  "columnDefs": [
    { "orderable": false, "targets": 0 }
  ]
} );

Display a float with two decimal places in Python

Using python string formatting.

>>> "%0.2f" % 3
'3.00'

How to see if an object is an array without using reflection?

You can create a utility class to check if the class represents any Collection, Map or Array

  public static boolean isCollection(Class<?> rawPropertyType) {
        return Collection.class.isAssignableFrom(rawPropertyType) || 
               Map.class.isAssignableFrom(rawPropertyType) || 
               rawPropertyType.isArray();
 }

How can I include css files using node, express, and ejs?

The above responses half worked and I'm not why they didn't on my machine but I had to do the following for it work.

  1. Created a directory at the root

    /public/js/

  2. Paste this into your server.js file with name matching the name of directory created above. Note adding /public as the first param

    app.use('/public',express.static('public'));

  3. Finally in the HTML page to which to import the javascript file into,

    <script src="public/js/bundle.js"></script>

How to fix libeay32.dll was not found error

For windows, you need to download the latest version of the open SSL binaries at this time is:

openssl-1.0.2k-x64_86-win64.zip

openSSL list

this problem happened to me when I tried to run MongoDB bin in windows 10

source to download: https://indy.fulgan.com/SSL/

Python Array with String Indices

What you want is called an associative array. In python these are called dictionaries.

Dictionaries are sometimes found in other languages as “associative memories” or “associative arrays”. Unlike sequences, which are indexed by a range of numbers, dictionaries are indexed by keys, which can be any immutable type; strings and numbers can always be keys.

myDict = {}
myDict["john"] = "johns value"
myDict["jeff"] = "jeffs value"

Alternative way to create the above dict:

myDict = {"john": "johns value", "jeff": "jeffs value"}

Accessing values:

print(myDict["jeff"]) # => "jeffs value"

Getting the keys (in Python v2):

print(myDict.keys()) # => ["john", "jeff"]

In Python 3, you'll get a dict_keys, which is a view and a bit more efficient (see views docs and PEP 3106 for details).

print(myDict.keys()) # => dict_keys(['john', 'jeff']) 

If you want to learn about python dictionary internals, I recommend this ~25 min video presentation: https://www.youtube.com/watch?v=C4Kc8xzcA68. It's called the "The Mighty Dictionary".

Angular 2: How to call a function after get a response from subscribe http.post

You can add a callback function to your list of get_category(...) parameters.

Ex:

 get_categories(number, callback){
 this.http.post( url, body, {headers: headers, withCredentials:true})
    .subscribe( 
      response => {
        this.total = response.json();
        callback(); 

      }, error => {
    }
  ); 

}

And then you can just call get_category(...) like this:

this.get_category(1, name_of_function);

Get 2 Digit Number For The Month

Another simple trick:

SELECT CONVERT(char(2), cast('2015-01-01' as datetime), 101) -- month with 2 digits
SELECT CONVERT(char(6), cast('2015-01-01' as datetime), 112) -- year (yyyy) and month (mm)

Outputs:

01
201501

Execute external program

This is not right. Here's how you should use Runtime.exec(). You might also try its more modern cousin, ProcessBuilder:

Java Runtime.getRuntime().exec() alternatives

Converting an integer to a hexadecimal string in Ruby

Here's another approach:

sprintf("%02x", 10).upcase

see the documentation for sprintf here: http://www.ruby-doc.org/core/classes/Kernel.html#method-i-sprintf

postgresql - replace all instances of a string within text field

The Regular Expression Way

If you need stricter replacement matching, PostgreSQL's regexp_replace function can match using POSIX regular expression patterns. It has the syntax regexp_replace(source, pattern, replacement [, flags ]).

I will use flags i and g for case-insensitive and global matching, respectively. I will also use \m and \M to match the beginning and the end of a word, respectively.

There are usually quite a few gotchas when performing regex replacment. Let's see how easy it is to replace a cat with a dog.

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog');
-->                    Cat bobdog cat cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'i');
-->                    dog bobcat cat cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'g');
-->                    Cat bobdog dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat', 'dog', 'gi');
-->                    dog bobdog dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat', 'dog', 'gi');
-->                    dog bobcat dog dogs dogfish

SELECT regexp_replace('Cat bobcat cat cats catfish', 'cat\M', 'dog', 'gi');
-->                    dog bobdog dog cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat\M', 'dog', 'gi');
-->                    dog bobcat dog cats catfish

SELECT regexp_replace('Cat bobcat cat cats catfish', '\mcat(s?)\M', 'dog\1', 'gi');
-->                    dog bobcat dog dogs catfish

Even after all of that, there is at least one unresolved condition. For example, sentences that begin with "Cat" will be replaced with lower-case "dog" which break sentence capitalization.

Check out the current PostgreSQL pattern matching docs for all the details.

Update entire column with replacement text

Given my examples, maybe the safest option would be:

UPDATE table SET field = regexp_replace(field, '\mcat\M', 'dog', 'gi');

How to know elastic search installed version from kibana?

If you have installed x-pack to secure elasticseach, the request should contains the valid credential details.

curl -XGET -u "elastic:passwordForElasticUser" 'localhost:9200'

Infact, if the security enabled all the subsequent requests should follow the same pattern (inline credentials should be provided).

Angular - Can't make ng-repeat orderBy work

the built-in orderBy filter will no longer work when iterating an object. It’s ignored due to the way that object fields are stored. You need create a custom filter

yourApp.filter('orderObjectBy', function() {
  return function(items, field, reverse) {
    var filtered = [];
    angular.forEach(items, function(item) {
      filtered.push(item);
    });
    filtered.sort(function (a, b) {
      return (a[field] > b[field] ? 1 : -1);
    });
    if(reverse) filtered.reverse();
    return filtered;
  };
});

<ul>
<li ng-repeat="item in items | orderObjectBy:'color':true">{{ item.color }}</li>
</ul>

How can I copy data from one column to another in the same table?

UPDATE table_name SET
    destination_column_name=orig_column_name
WHERE condition_if_necessary

Apache redirect to another port

This is working in ISPConfig too. In website list get inside a domain, click to Options tab, add these lines: ;

ProxyPass / http://localhost:8181/
ProxyPassReverse / http://localhost:8181/

Then go to website and wolaa :) This is working HTTPS protocol too.

Dynamically adding HTML form field using jQuery

You can add any type of HTML with methods like append and appendTo (among others):

jQuery manipulation methods

Example:

$('form#someform').append('<input type="text" name="something" id="something" />');